# char/ comes before serial/ etc so that the VT console is the boot-time
# default.
+obj-y += tty/
obj-y += char/
# gpu/ comes after char for AGP vs DRM startup
#
FONTMAPFILE = cp437.uni
-obj-y += mem.o random.o tty_io.o n_tty.o tty_ioctl.o tty_ldisc.o tty_buffer.o tty_port.o
-
-obj-y += tty_mutex.o
-obj-$(CONFIG_LEGACY_PTYS) += pty.o
-obj-$(CONFIG_UNIX98_PTYS) += pty.o
+obj-y += mem.o random.o
obj-$(CONFIG_TTY_PRINTK) += ttyprintk.o
obj-y += misc.o
obj-$(CONFIG_VT) += vt_ioctl.o vc_screen.o selection.o keyboard.o
obj-$(CONFIG_BFIN_JTAG_COMM) += bfin_jtag_comm.o
obj-$(CONFIG_CONSOLE_TRANSLATIONS) += consolemap.o consolemap_deftbl.o
obj-$(CONFIG_HW_CONSOLE) += vt.o defkeymap.o
-obj-$(CONFIG_AUDIT) += tty_audit.o
-obj-$(CONFIG_MAGIC_SYSRQ) += sysrq.o
obj-$(CONFIG_MVME147_SCC) += generic_serial.o vme_scc.o
obj-$(CONFIG_MVME162_SCC) += generic_serial.o vme_scc.o
obj-$(CONFIG_BVME6000_SCC) += generic_serial.o vme_scc.o
obj-$(CONFIG_SYNCLINK) += synclink.o
obj-$(CONFIG_SYNCLINKMP) += synclinkmp.o
obj-$(CONFIG_SYNCLINK_GT) += synclink_gt.o
-obj-$(CONFIG_N_HDLC) += n_hdlc.o
-obj-$(CONFIG_N_GSM) += n_gsm.o
obj-$(CONFIG_AMIGA_BUILTIN_SERIAL) += amiserial.o
obj-$(CONFIG_SX) += sx.o generic_serial.o
obj-$(CONFIG_RIO) += rio/ generic_serial.o
obj-$(CONFIG_APM_EMULATION) += apm-emulation.o
obj-$(CONFIG_DTLK) += dtlk.o
-obj-$(CONFIG_R3964) += n_r3964.o
obj-$(CONFIG_APPLICOM) += applicom.o
obj-$(CONFIG_SONYPI) += sonypi.o
obj-$(CONFIG_RTC) += rtc.o
+++ /dev/null
-/*
- * n_gsm.c GSM 0710 tty multiplexor
- * Copyright (c) 2009/10 Intel Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * * THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE *
- *
- * TO DO:
- * Mostly done: ioctls for setting modes/timing
- * Partly done: hooks so you can pull off frames to non tty devs
- * Restart DLCI 0 when it closes ?
- * Test basic encoding
- * Improve the tx engine
- * Resolve tx side locking by adding a queue_head and routing
- * all control traffic via it
- * General tidy/document
- * Review the locking/move to refcounts more (mux now moved to an
- * alloc/free model ready)
- * Use newest tty open/close port helpers and install hooks
- * What to do about power functions ?
- * Termios setting and negotiation
- * Do we need a 'which mux are you' ioctl to correlate mux and tty sets
- *
- */
-
-#include <linux/types.h>
-#include <linux/major.h>
-#include <linux/errno.h>
-#include <linux/signal.h>
-#include <linux/fcntl.h>
-#include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/tty.h>
-#include <linux/ctype.h>
-#include <linux/mm.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/poll.h>
-#include <linux/bitops.h>
-#include <linux/file.h>
-#include <linux/uaccess.h>
-#include <linux/module.h>
-#include <linux/timer.h>
-#include <linux/tty_flip.h>
-#include <linux/tty_driver.h>
-#include <linux/serial.h>
-#include <linux/kfifo.h>
-#include <linux/skbuff.h>
-#include <linux/gsmmux.h>
-
-static int debug;
-module_param(debug, int, 0600);
-
-#define T1 (HZ/10)
-#define T2 (HZ/3)
-#define N2 3
-
-/* Use long timers for testing at low speed with debug on */
-#ifdef DEBUG_TIMING
-#define T1 HZ
-#define T2 (2 * HZ)
-#endif
-
-/* Semi-arbitary buffer size limits. 0710 is normally run with 32-64 byte
- limits so this is plenty */
-#define MAX_MRU 512
-#define MAX_MTU 512
-
-/*
- * Each block of data we have queued to go out is in the form of
- * a gsm_msg which holds everything we need in a link layer independant
- * format
- */
-
-struct gsm_msg {
- struct gsm_msg *next;
- u8 addr; /* DLCI address + flags */
- u8 ctrl; /* Control byte + flags */
- unsigned int len; /* Length of data block (can be zero) */
- unsigned char *data; /* Points into buffer but not at the start */
- unsigned char buffer[0];
-};
-
-/*
- * Each active data link has a gsm_dlci structure associated which ties
- * the link layer to an optional tty (if the tty side is open). To avoid
- * complexity right now these are only ever freed up when the mux is
- * shut down.
- *
- * At the moment we don't free DLCI objects until the mux is torn down
- * this avoid object life time issues but might be worth review later.
- */
-
-struct gsm_dlci {
- struct gsm_mux *gsm;
- int addr;
- int state;
-#define DLCI_CLOSED 0
-#define DLCI_OPENING 1 /* Sending SABM not seen UA */
-#define DLCI_OPEN 2 /* SABM/UA complete */
-#define DLCI_CLOSING 3 /* Sending DISC not seen UA/DM */
-
- /* Link layer */
- spinlock_t lock; /* Protects the internal state */
- struct timer_list t1; /* Retransmit timer for SABM and UA */
- int retries;
- /* Uplink tty if active */
- struct tty_port port; /* The tty bound to this DLCI if there is one */
- struct kfifo *fifo; /* Queue fifo for the DLCI */
- struct kfifo _fifo; /* For new fifo API porting only */
- int adaption; /* Adaption layer in use */
- u32 modem_rx; /* Our incoming virtual modem lines */
- u32 modem_tx; /* Our outgoing modem lines */
- int dead; /* Refuse re-open */
- /* Flow control */
- int throttled; /* Private copy of throttle state */
- int constipated; /* Throttle status for outgoing */
- /* Packetised I/O */
- struct sk_buff *skb; /* Frame being sent */
- struct sk_buff_head skb_list; /* Queued frames */
- /* Data handling callback */
- void (*data)(struct gsm_dlci *dlci, u8 *data, int len);
-};
-
-/* DLCI 0, 62/63 are special or reseved see gsmtty_open */
-
-#define NUM_DLCI 64
-
-/*
- * DLCI 0 is used to pass control blocks out of band of the data
- * flow (and with a higher link priority). One command can be outstanding
- * at a time and we use this structure to manage them. They are created
- * and destroyed by the user context, and updated by the receive paths
- * and timers
- */
-
-struct gsm_control {
- u8 cmd; /* Command we are issuing */
- u8 *data; /* Data for the command in case we retransmit */
- int len; /* Length of block for retransmission */
- int done; /* Done flag */
- int error; /* Error if any */
-};
-
-/*
- * Each GSM mux we have is represented by this structure. If we are
- * operating as an ldisc then we use this structure as our ldisc
- * state. We need to sort out lifetimes and locking with respect
- * to the gsm mux array. For now we don't free DLCI objects that
- * have been instantiated until the mux itself is terminated.
- *
- * To consider further: tty open versus mux shutdown.
- */
-
-struct gsm_mux {
- struct tty_struct *tty; /* The tty our ldisc is bound to */
- spinlock_t lock;
-
- /* Events on the GSM channel */
- wait_queue_head_t event;
-
- /* Bits for GSM mode decoding */
-
- /* Framing Layer */
- unsigned char *buf;
- int state;
-#define GSM_SEARCH 0
-#define GSM_START 1
-#define GSM_ADDRESS 2
-#define GSM_CONTROL 3
-#define GSM_LEN 4
-#define GSM_DATA 5
-#define GSM_FCS 6
-#define GSM_OVERRUN 7
- unsigned int len;
- unsigned int address;
- unsigned int count;
- int escape;
- int encoding;
- u8 control;
- u8 fcs;
- u8 *txframe; /* TX framing buffer */
-
- /* Methods for the receiver side */
- void (*receive)(struct gsm_mux *gsm, u8 ch);
- void (*error)(struct gsm_mux *gsm, u8 ch, u8 flag);
- /* And transmit side */
- int (*output)(struct gsm_mux *mux, u8 *data, int len);
-
- /* Link Layer */
- unsigned int mru;
- unsigned int mtu;
- int initiator; /* Did we initiate connection */
- int dead; /* Has the mux been shut down */
- struct gsm_dlci *dlci[NUM_DLCI];
- int constipated; /* Asked by remote to shut up */
-
- spinlock_t tx_lock;
- unsigned int tx_bytes; /* TX data outstanding */
-#define TX_THRESH_HI 8192
-#define TX_THRESH_LO 2048
- struct gsm_msg *tx_head; /* Pending data packets */
- struct gsm_msg *tx_tail;
-
- /* Control messages */
- struct timer_list t2_timer; /* Retransmit timer for commands */
- int cretries; /* Command retry counter */
- struct gsm_control *pending_cmd;/* Our current pending command */
- spinlock_t control_lock; /* Protects the pending command */
-
- /* Configuration */
- int adaption; /* 1 or 2 supported */
- u8 ftype; /* UI or UIH */
- int t1, t2; /* Timers in 1/100th of a sec */
- int n2; /* Retry count */
-
- /* Statistics (not currently exposed) */
- unsigned long bad_fcs;
- unsigned long malformed;
- unsigned long io_error;
- unsigned long bad_size;
- unsigned long unsupported;
-};
-
-
-/*
- * Mux objects - needed so that we can translate a tty index into the
- * relevant mux and DLCI.
- */
-
-#define MAX_MUX 4 /* 256 minors */
-static struct gsm_mux *gsm_mux[MAX_MUX]; /* GSM muxes */
-static spinlock_t gsm_mux_lock;
-
-/*
- * This section of the driver logic implements the GSM encodings
- * both the basic and the 'advanced'. Reliable transport is not
- * supported.
- */
-
-#define CR 0x02
-#define EA 0x01
-#define PF 0x10
-
-/* I is special: the rest are ..*/
-#define RR 0x01
-#define UI 0x03
-#define RNR 0x05
-#define REJ 0x09
-#define DM 0x0F
-#define SABM 0x2F
-#define DISC 0x43
-#define UA 0x63
-#define UIH 0xEF
-
-/* Channel commands */
-#define CMD_NSC 0x09
-#define CMD_TEST 0x11
-#define CMD_PSC 0x21
-#define CMD_RLS 0x29
-#define CMD_FCOFF 0x31
-#define CMD_PN 0x41
-#define CMD_RPN 0x49
-#define CMD_FCON 0x51
-#define CMD_CLD 0x61
-#define CMD_SNC 0x69
-#define CMD_MSC 0x71
-
-/* Virtual modem bits */
-#define MDM_FC 0x01
-#define MDM_RTC 0x02
-#define MDM_RTR 0x04
-#define MDM_IC 0x20
-#define MDM_DV 0x40
-
-#define GSM0_SOF 0xF9
-#define GSM1_SOF 0x7E
-#define GSM1_ESCAPE 0x7D
-#define GSM1_ESCAPE_BITS 0x20
-#define XON 0x11
-#define XOFF 0x13
-
-static const struct tty_port_operations gsm_port_ops;
-
-/*
- * CRC table for GSM 0710
- */
-
-static const u8 gsm_fcs8[256] = {
- 0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75,
- 0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B,
- 0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69,
- 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67,
- 0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D,
- 0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43,
- 0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51,
- 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
- 0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05,
- 0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B,
- 0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19,
- 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17,
- 0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D,
- 0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33,
- 0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21,
- 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
- 0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95,
- 0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B,
- 0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89,
- 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87,
- 0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD,
- 0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3,
- 0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1,
- 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
- 0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5,
- 0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB,
- 0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9,
- 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7,
- 0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD,
- 0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3,
- 0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1,
- 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
-};
-
-#define INIT_FCS 0xFF
-#define GOOD_FCS 0xCF
-
-/**
- * gsm_fcs_add - update FCS
- * @fcs: Current FCS
- * @c: Next data
- *
- * Update the FCS to include c. Uses the algorithm in the specification
- * notes.
- */
-
-static inline u8 gsm_fcs_add(u8 fcs, u8 c)
-{
- return gsm_fcs8[fcs ^ c];
-}
-
-/**
- * gsm_fcs_add_block - update FCS for a block
- * @fcs: Current FCS
- * @c: buffer of data
- * @len: length of buffer
- *
- * Update the FCS to include c. Uses the algorithm in the specification
- * notes.
- */
-
-static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len)
-{
- while (len--)
- fcs = gsm_fcs8[fcs ^ *c++];
- return fcs;
-}
-
-/**
- * gsm_read_ea - read a byte into an EA
- * @val: variable holding value
- * c: byte going into the EA
- *
- * Processes one byte of an EA. Updates the passed variable
- * and returns 1 if the EA is now completely read
- */
-
-static int gsm_read_ea(unsigned int *val, u8 c)
-{
- /* Add the next 7 bits into the value */
- *val <<= 7;
- *val |= c >> 1;
- /* Was this the last byte of the EA 1 = yes*/
- return c & EA;
-}
-
-/**
- * gsm_encode_modem - encode modem data bits
- * @dlci: DLCI to encode from
- *
- * Returns the correct GSM encoded modem status bits (6 bit field) for
- * the current status of the DLCI and attached tty object
- */
-
-static u8 gsm_encode_modem(const struct gsm_dlci *dlci)
-{
- u8 modembits = 0;
- /* FC is true flow control not modem bits */
- if (dlci->throttled)
- modembits |= MDM_FC;
- if (dlci->modem_tx & TIOCM_DTR)
- modembits |= MDM_RTC;
- if (dlci->modem_tx & TIOCM_RTS)
- modembits |= MDM_RTR;
- if (dlci->modem_tx & TIOCM_RI)
- modembits |= MDM_IC;
- if (dlci->modem_tx & TIOCM_CD)
- modembits |= MDM_DV;
- return modembits;
-}
-
-/**
- * gsm_print_packet - display a frame for debug
- * @hdr: header to print before decode
- * @addr: address EA from the frame
- * @cr: C/R bit from the frame
- * @control: control including PF bit
- * @data: following data bytes
- * @dlen: length of data
- *
- * Displays a packet in human readable format for debugging purposes. The
- * style is based on amateur radio LAP-B dump display.
- */
-
-static void gsm_print_packet(const char *hdr, int addr, int cr,
- u8 control, const u8 *data, int dlen)
-{
- if (!(debug & 1))
- return;
-
- printk(KERN_INFO "%s %d) %c: ", hdr, addr, "RC"[cr]);
-
- switch (control & ~PF) {
- case SABM:
- printk(KERN_CONT "SABM");
- break;
- case UA:
- printk(KERN_CONT "UA");
- break;
- case DISC:
- printk(KERN_CONT "DISC");
- break;
- case DM:
- printk(KERN_CONT "DM");
- break;
- case UI:
- printk(KERN_CONT "UI");
- break;
- case UIH:
- printk(KERN_CONT "UIH");
- break;
- default:
- if (!(control & 0x01)) {
- printk(KERN_CONT "I N(S)%d N(R)%d",
- (control & 0x0E) >> 1, (control & 0xE)>> 5);
- } else switch (control & 0x0F) {
- case RR:
- printk("RR(%d)", (control & 0xE0) >> 5);
- break;
- case RNR:
- printk("RNR(%d)", (control & 0xE0) >> 5);
- break;
- case REJ:
- printk("REJ(%d)", (control & 0xE0) >> 5);
- break;
- default:
- printk(KERN_CONT "[%02X]", control);
- }
- }
-
- if (control & PF)
- printk(KERN_CONT "(P)");
- else
- printk(KERN_CONT "(F)");
-
- if (dlen) {
- int ct = 0;
- while (dlen--) {
- if (ct % 8 == 0)
- printk(KERN_CONT "\n ");
- printk(KERN_CONT "%02X ", *data++);
- ct++;
- }
- }
- printk(KERN_CONT "\n");
-}
-
-
-/*
- * Link level transmission side
- */
-
-/**
- * gsm_stuff_packet - bytestuff a packet
- * @ibuf: input
- * @obuf: output
- * @len: length of input
- *
- * Expand a buffer by bytestuffing it. The worst case size change
- * is doubling and the caller is responsible for handing out
- * suitable sized buffers.
- */
-
-static int gsm_stuff_frame(const u8 *input, u8 *output, int len)
-{
- int olen = 0;
- while (len--) {
- if (*input == GSM1_SOF || *input == GSM1_ESCAPE
- || *input == XON || *input == XOFF) {
- *output++ = GSM1_ESCAPE;
- *output++ = *input++ ^ GSM1_ESCAPE_BITS;
- olen++;
- } else
- *output++ = *input++;
- olen++;
- }
- return olen;
-}
-
-static void hex_packet(const unsigned char *p, int len)
-{
- int i;
- for (i = 0; i < len; i++) {
- if (i && (i % 16) == 0)
- printk("\n");
- printk("%02X ", *p++);
- }
- printk("\n");
-}
-
-/**
- * gsm_send - send a control frame
- * @gsm: our GSM mux
- * @addr: address for control frame
- * @cr: command/response bit
- * @control: control byte including PF bit
- *
- * Format up and transmit a control frame. These do not go via the
- * queueing logic as they should be transmitted ahead of data when
- * they are needed.
- *
- * FIXME: Lock versus data TX path
- */
-
-static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
-{
- int len;
- u8 cbuf[10];
- u8 ibuf[3];
-
- switch (gsm->encoding) {
- case 0:
- cbuf[0] = GSM0_SOF;
- cbuf[1] = (addr << 2) | (cr << 1) | EA;
- cbuf[2] = control;
- cbuf[3] = EA; /* Length of data = 0 */
- cbuf[4] = 0xFF - gsm_fcs_add_block(INIT_FCS, cbuf + 1, 3);
- cbuf[5] = GSM0_SOF;
- len = 6;
- break;
- case 1:
- case 2:
- /* Control frame + packing (but not frame stuffing) in mode 1 */
- ibuf[0] = (addr << 2) | (cr << 1) | EA;
- ibuf[1] = control;
- ibuf[2] = 0xFF - gsm_fcs_add_block(INIT_FCS, ibuf, 2);
- /* Stuffing may double the size worst case */
- len = gsm_stuff_frame(ibuf, cbuf + 1, 3);
- /* Now add the SOF markers */
- cbuf[0] = GSM1_SOF;
- cbuf[len + 1] = GSM1_SOF;
- /* FIXME: we can omit the lead one in many cases */
- len += 2;
- break;
- default:
- WARN_ON(1);
- return;
- }
- gsm->output(gsm, cbuf, len);
- gsm_print_packet("-->", addr, cr, control, NULL, 0);
-}
-
-/**
- * gsm_response - send a control response
- * @gsm: our GSM mux
- * @addr: address for control frame
- * @control: control byte including PF bit
- *
- * Format up and transmit a link level response frame.
- */
-
-static inline void gsm_response(struct gsm_mux *gsm, int addr, int control)
-{
- gsm_send(gsm, addr, 0, control);
-}
-
-/**
- * gsm_command - send a control command
- * @gsm: our GSM mux
- * @addr: address for control frame
- * @control: control byte including PF bit
- *
- * Format up and transmit a link level command frame.
- */
-
-static inline void gsm_command(struct gsm_mux *gsm, int addr, int control)
-{
- gsm_send(gsm, addr, 1, control);
-}
-
-/* Data transmission */
-
-#define HDR_LEN 6 /* ADDR CTRL [LEN.2] DATA FCS */
-
-/**
- * gsm_data_alloc - allocate data frame
- * @gsm: GSM mux
- * @addr: DLCI address
- * @len: length excluding header and FCS
- * @ctrl: control byte
- *
- * Allocate a new data buffer for sending frames with data. Space is left
- * at the front for header bytes but that is treated as an implementation
- * detail and not for the high level code to use
- */
-
-static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len,
- u8 ctrl)
-{
- struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN,
- GFP_ATOMIC);
- if (m == NULL)
- return NULL;
- m->data = m->buffer + HDR_LEN - 1; /* Allow for FCS */
- m->len = len;
- m->addr = addr;
- m->ctrl = ctrl;
- m->next = NULL;
- return m;
-}
-
-/**
- * gsm_data_kick - poke the queue
- * @gsm: GSM Mux
- *
- * The tty device has called us to indicate that room has appeared in
- * the transmit queue. Ram more data into the pipe if we have any
- *
- * FIXME: lock against link layer control transmissions
- */
-
-static void gsm_data_kick(struct gsm_mux *gsm)
-{
- struct gsm_msg *msg = gsm->tx_head;
- int len;
- int skip_sof = 0;
-
- /* FIXME: We need to apply this solely to data messages */
- if (gsm->constipated)
- return;
-
- while (gsm->tx_head != NULL) {
- msg = gsm->tx_head;
- if (gsm->encoding != 0) {
- gsm->txframe[0] = GSM1_SOF;
- len = gsm_stuff_frame(msg->data,
- gsm->txframe + 1, msg->len);
- gsm->txframe[len + 1] = GSM1_SOF;
- len += 2;
- } else {
- gsm->txframe[0] = GSM0_SOF;
- memcpy(gsm->txframe + 1 , msg->data, msg->len);
- gsm->txframe[msg->len + 1] = GSM0_SOF;
- len = msg->len + 2;
- }
-
- if (debug & 4) {
- printk("gsm_data_kick: \n");
- hex_packet(gsm->txframe, len);
- }
-
- if (gsm->output(gsm, gsm->txframe + skip_sof,
- len - skip_sof) < 0)
- break;
- /* FIXME: Can eliminate one SOF in many more cases */
- gsm->tx_head = msg->next;
- if (gsm->tx_head == NULL)
- gsm->tx_tail = NULL;
- gsm->tx_bytes -= msg->len;
- kfree(msg);
- /* For a burst of frames skip the extra SOF within the
- burst */
- skip_sof = 1;
- }
-}
-
-/**
- * __gsm_data_queue - queue a UI or UIH frame
- * @dlci: DLCI sending the data
- * @msg: message queued
- *
- * Add data to the transmit queue and try and get stuff moving
- * out of the mux tty if not already doing so. The Caller must hold
- * the gsm tx lock.
- */
-
-static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
-{
- struct gsm_mux *gsm = dlci->gsm;
- u8 *dp = msg->data;
- u8 *fcs = dp + msg->len;
-
- /* Fill in the header */
- if (gsm->encoding == 0) {
- if (msg->len < 128)
- *--dp = (msg->len << 1) | EA;
- else {
- *--dp = (msg->len >> 6) | EA;
- *--dp = (msg->len & 127) << 1;
- }
- }
-
- *--dp = msg->ctrl;
- if (gsm->initiator)
- *--dp = (msg->addr << 2) | 2 | EA;
- else
- *--dp = (msg->addr << 2) | EA;
- *fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp);
- /* Ugly protocol layering violation */
- if (msg->ctrl == UI || msg->ctrl == (UI|PF))
- *fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len);
- *fcs = 0xFF - *fcs;
-
- gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl,
- msg->data, msg->len);
-
- /* Move the header back and adjust the length, also allow for the FCS
- now tacked on the end */
- msg->len += (msg->data - dp) + 1;
- msg->data = dp;
-
- /* Add to the actual output queue */
- if (gsm->tx_tail)
- gsm->tx_tail->next = msg;
- else
- gsm->tx_head = msg;
- gsm->tx_tail = msg;
- gsm->tx_bytes += msg->len;
- gsm_data_kick(gsm);
-}
-
-/**
- * gsm_data_queue - queue a UI or UIH frame
- * @dlci: DLCI sending the data
- * @msg: message queued
- *
- * Add data to the transmit queue and try and get stuff moving
- * out of the mux tty if not already doing so. Take the
- * the gsm tx lock and dlci lock.
- */
-
-static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
-{
- unsigned long flags;
- spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
- __gsm_data_queue(dlci, msg);
- spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
-}
-
-/**
- * gsm_dlci_data_output - try and push data out of a DLCI
- * @gsm: mux
- * @dlci: the DLCI to pull data from
- *
- * Pull data from a DLCI and send it into the transmit queue if there
- * is data. Keep to the MRU of the mux. This path handles the usual tty
- * interface which is a byte stream with optional modem data.
- *
- * Caller must hold the tx_lock of the mux.
- */
-
-static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
-{
- struct gsm_msg *msg;
- u8 *dp;
- int len, size;
- int h = dlci->adaption - 1;
-
- len = kfifo_len(dlci->fifo);
- if (len == 0)
- return 0;
-
- /* MTU/MRU count only the data bits */
- if (len > gsm->mtu)
- len = gsm->mtu;
-
- size = len + h;
-
- msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype);
- /* FIXME: need a timer or something to kick this so it can't
- get stuck with no work outstanding and no buffer free */
- if (msg == NULL)
- return -ENOMEM;
- dp = msg->data;
- switch (dlci->adaption) {
- case 1: /* Unstructured */
- break;
- case 2: /* Unstructed with modem bits. Always one byte as we never
- send inline break data */
- *dp += gsm_encode_modem(dlci);
- len--;
- break;
- }
- WARN_ON(kfifo_out_locked(dlci->fifo, dp , len, &dlci->lock) != len);
- __gsm_data_queue(dlci, msg);
- /* Bytes of data we used up */
- return size;
-}
-
-/**
- * gsm_dlci_data_output_framed - try and push data out of a DLCI
- * @gsm: mux
- * @dlci: the DLCI to pull data from
- *
- * Pull data from a DLCI and send it into the transmit queue if there
- * is data. Keep to the MRU of the mux. This path handles framed data
- * queued as skbuffs to the DLCI.
- *
- * Caller must hold the tx_lock of the mux.
- */
-
-static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
- struct gsm_dlci *dlci)
-{
- struct gsm_msg *msg;
- u8 *dp;
- int len, size;
- int last = 0, first = 0;
- int overhead = 0;
-
- /* One byte per frame is used for B/F flags */
- if (dlci->adaption == 4)
- overhead = 1;
-
- /* dlci->skb is locked by tx_lock */
- if (dlci->skb == NULL) {
- dlci->skb = skb_dequeue(&dlci->skb_list);
- if (dlci->skb == NULL)
- return 0;
- first = 1;
- }
- len = dlci->skb->len + overhead;
-
- /* MTU/MRU count only the data bits */
- if (len > gsm->mtu) {
- if (dlci->adaption == 3) {
- /* Over long frame, bin it */
- kfree_skb(dlci->skb);
- dlci->skb = NULL;
- return 0;
- }
- len = gsm->mtu;
- } else
- last = 1;
-
- size = len + overhead;
- msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype);
-
- /* FIXME: need a timer or something to kick this so it can't
- get stuck with no work outstanding and no buffer free */
- if (msg == NULL)
- return -ENOMEM;
- dp = msg->data;
-
- if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */
- /* Flag byte to carry the start/end info */
- *dp++ = last << 7 | first << 6 | 1; /* EA */
- len--;
- }
- memcpy(dp, skb_pull(dlci->skb, len), len);
- __gsm_data_queue(dlci, msg);
- if (last)
- dlci->skb = NULL;
- return size;
-}
-
-/**
- * gsm_dlci_data_sweep - look for data to send
- * @gsm: the GSM mux
- *
- * Sweep the GSM mux channels in priority order looking for ones with
- * data to send. We could do with optimising this scan a bit. We aim
- * to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit
- * TX_THRESH_LO we get called again
- *
- * FIXME: We should round robin between groups and in theory you can
- * renegotiate DLCI priorities with optional stuff. Needs optimising.
- */
-
-static void gsm_dlci_data_sweep(struct gsm_mux *gsm)
-{
- int len;
- /* Priority ordering: We should do priority with RR of the groups */
- int i = 1;
-
- while (i < NUM_DLCI) {
- struct gsm_dlci *dlci;
-
- if (gsm->tx_bytes > TX_THRESH_HI)
- break;
- dlci = gsm->dlci[i];
- if (dlci == NULL || dlci->constipated) {
- i++;
- continue;
- }
- if (dlci->adaption < 3)
- len = gsm_dlci_data_output(gsm, dlci);
- else
- len = gsm_dlci_data_output_framed(gsm, dlci);
- if (len < 0)
- break;
- /* DLCI empty - try the next */
- if (len == 0)
- i++;
- }
-}
-
-/**
- * gsm_dlci_data_kick - transmit if possible
- * @dlci: DLCI to kick
- *
- * Transmit data from this DLCI if the queue is empty. We can't rely on
- * a tty wakeup except when we filled the pipe so we need to fire off
- * new data ourselves in other cases.
- */
-
-static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
- /* If we have nothing running then we need to fire up */
- if (dlci->gsm->tx_bytes == 0)
- gsm_dlci_data_output(dlci->gsm, dlci);
- else if (dlci->gsm->tx_bytes < TX_THRESH_LO)
- gsm_dlci_data_sweep(dlci->gsm);
- spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
-}
-
-/*
- * Control message processing
- */
-
-
-/**
- * gsm_control_reply - send a response frame to a control
- * @gsm: gsm channel
- * @cmd: the command to use
- * @data: data to follow encoded info
- * @dlen: length of data
- *
- * Encode up and queue a UI/UIH frame containing our response.
- */
-
-static void gsm_control_reply(struct gsm_mux *gsm, int cmd, u8 *data,
- int dlen)
-{
- struct gsm_msg *msg;
- msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype);
- msg->data[0] = (cmd & 0xFE) << 1 | EA; /* Clear C/R */
- msg->data[1] = (dlen << 1) | EA;
- memcpy(msg->data + 2, data, dlen);
- gsm_data_queue(gsm->dlci[0], msg);
-}
-
-/**
- * gsm_process_modem - process received modem status
- * @tty: virtual tty bound to the DLCI
- * @dlci: DLCI to affect
- * @modem: modem bits (full EA)
- *
- * Used when a modem control message or line state inline in adaption
- * layer 2 is processed. Sort out the local modem state and throttles
- */
-
-static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci,
- u32 modem)
-{
- int mlines = 0;
- u8 brk = modem >> 6;
-
- /* Flow control/ready to communicate */
- if (modem & MDM_FC) {
- /* Need to throttle our output on this device */
- dlci->constipated = 1;
- }
- if (modem & MDM_RTC) {
- mlines |= TIOCM_DSR | TIOCM_DTR;
- dlci->constipated = 0;
- gsm_dlci_data_kick(dlci);
- }
- /* Map modem bits */
- if (modem & MDM_RTR)
- mlines |= TIOCM_RTS | TIOCM_CTS;
- if (modem & MDM_IC)
- mlines |= TIOCM_RI;
- if (modem & MDM_DV)
- mlines |= TIOCM_CD;
-
- /* Carrier drop -> hangup */
- if (tty) {
- if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD))
- if (!(tty->termios->c_cflag & CLOCAL))
- tty_hangup(tty);
- if (brk & 0x01)
- tty_insert_flip_char(tty, 0, TTY_BREAK);
- }
- dlci->modem_rx = mlines;
-}
-
-/**
- * gsm_control_modem - modem status received
- * @gsm: GSM channel
- * @data: data following command
- * @clen: command length
- *
- * We have received a modem status control message. This is used by
- * the GSM mux protocol to pass virtual modem line status and optionally
- * to indicate break signals. Unpack it, convert to Linux representation
- * and if need be stuff a break message down the tty.
- */
-
-static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen)
-{
- unsigned int addr = 0;
- unsigned int modem = 0;
- struct gsm_dlci *dlci;
- int len = clen;
- u8 *dp = data;
- struct tty_struct *tty;
-
- while (gsm_read_ea(&addr, *dp++) == 0) {
- len--;
- if (len == 0)
- return;
- }
- /* Must be at least one byte following the EA */
- len--;
- if (len <= 0)
- return;
-
- addr >>= 1;
- /* Closed port, or invalid ? */
- if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
- return;
- dlci = gsm->dlci[addr];
-
- while (gsm_read_ea(&modem, *dp++) == 0) {
- len--;
- if (len == 0)
- return;
- }
- tty = tty_port_tty_get(&dlci->port);
- gsm_process_modem(tty, dlci, modem);
- if (tty) {
- tty_wakeup(tty);
- tty_kref_put(tty);
- }
- gsm_control_reply(gsm, CMD_MSC, data, clen);
-}
-
-/**
- * gsm_control_rls - remote line status
- * @gsm: GSM channel
- * @data: data bytes
- * @clen: data length
- *
- * The modem sends us a two byte message on the control channel whenever
- * it wishes to send us an error state from the virtual link. Stuff
- * this into the uplink tty if present
- */
-
-static void gsm_control_rls(struct gsm_mux *gsm, u8 *data, int clen)
-{
- struct tty_struct *tty;
- unsigned int addr = 0 ;
- u8 bits;
- int len = clen;
- u8 *dp = data;
-
- while (gsm_read_ea(&addr, *dp++) == 0) {
- len--;
- if (len == 0)
- return;
- }
- /* Must be at least one byte following ea */
- len--;
- if (len <= 0)
- return;
- addr >>= 1;
- /* Closed port, or invalid ? */
- if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
- return;
- /* No error ? */
- bits = *dp;
- if ((bits & 1) == 0)
- return;
- /* See if we have an uplink tty */
- tty = tty_port_tty_get(&gsm->dlci[addr]->port);
-
- if (tty) {
- if (bits & 2)
- tty_insert_flip_char(tty, 0, TTY_OVERRUN);
- if (bits & 4)
- tty_insert_flip_char(tty, 0, TTY_PARITY);
- if (bits & 8)
- tty_insert_flip_char(tty, 0, TTY_FRAME);
- tty_flip_buffer_push(tty);
- tty_kref_put(tty);
- }
- gsm_control_reply(gsm, CMD_RLS, data, clen);
-}
-
-static void gsm_dlci_begin_close(struct gsm_dlci *dlci);
-
-/**
- * gsm_control_message - DLCI 0 control processing
- * @gsm: our GSM mux
- * @command: the command EA
- * @data: data beyond the command/length EAs
- * @clen: length
- *
- * Input processor for control messages from the other end of the link.
- * Processes the incoming request and queues a response frame or an
- * NSC response if not supported
- */
-
-static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
- u8 *data, int clen)
-{
- u8 buf[1];
- switch (command) {
- case CMD_CLD: {
- struct gsm_dlci *dlci = gsm->dlci[0];
- /* Modem wishes to close down */
- if (dlci) {
- dlci->dead = 1;
- gsm->dead = 1;
- gsm_dlci_begin_close(dlci);
- }
- }
- break;
- case CMD_TEST:
- /* Modem wishes to test, reply with the data */
- gsm_control_reply(gsm, CMD_TEST, data, clen);
- break;
- case CMD_FCON:
- /* Modem wants us to STFU */
- gsm->constipated = 1;
- gsm_control_reply(gsm, CMD_FCON, NULL, 0);
- break;
- case CMD_FCOFF:
- /* Modem can accept data again */
- gsm->constipated = 0;
- gsm_control_reply(gsm, CMD_FCOFF, NULL, 0);
- /* Kick the link in case it is idling */
- gsm_data_kick(gsm);
- break;
- case CMD_MSC:
- /* Out of band modem line change indicator for a DLCI */
- gsm_control_modem(gsm, data, clen);
- break;
- case CMD_RLS:
- /* Out of band error reception for a DLCI */
- gsm_control_rls(gsm, data, clen);
- break;
- case CMD_PSC:
- /* Modem wishes to enter power saving state */
- gsm_control_reply(gsm, CMD_PSC, NULL, 0);
- break;
- /* Optional unsupported commands */
- case CMD_PN: /* Parameter negotiation */
- case CMD_RPN: /* Remote port negotation */
- case CMD_SNC: /* Service negotation command */
- default:
- /* Reply to bad commands with an NSC */
- buf[0] = command;
- gsm_control_reply(gsm, CMD_NSC, buf, 1);
- break;
- }
-}
-
-/**
- * gsm_control_response - process a response to our control
- * @gsm: our GSM mux
- * @command: the command (response) EA
- * @data: data beyond the command/length EA
- * @clen: length
- *
- * Process a response to an outstanding command. We only allow a single
- * control message in flight so this is fairly easy. All the clean up
- * is done by the caller, we just update the fields, flag it as done
- * and return
- */
-
-static void gsm_control_response(struct gsm_mux *gsm, unsigned int command,
- u8 *data, int clen)
-{
- struct gsm_control *ctrl;
- unsigned long flags;
-
- spin_lock_irqsave(&gsm->control_lock, flags);
-
- ctrl = gsm->pending_cmd;
- /* Does the reply match our command */
- command |= 1;
- if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) {
- /* Our command was replied to, kill the retry timer */
- del_timer(&gsm->t2_timer);
- gsm->pending_cmd = NULL;
- /* Rejected by the other end */
- if (command == CMD_NSC)
- ctrl->error = -EOPNOTSUPP;
- ctrl->done = 1;
- wake_up(&gsm->event);
- }
- spin_unlock_irqrestore(&gsm->control_lock, flags);
-}
-
-/**
- * gsm_control_transmit - send control packet
- * @gsm: gsm mux
- * @ctrl: frame to send
- *
- * Send out a pending control command (called under control lock)
- */
-
-static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl)
-{
- struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 1,
- gsm->ftype|PF);
- if (msg == NULL)
- return;
- msg->data[0] = (ctrl->cmd << 1) | 2 | EA; /* command */
- memcpy(msg->data + 1, ctrl->data, ctrl->len);
- gsm_data_queue(gsm->dlci[0], msg);
-}
-
-/**
- * gsm_control_retransmit - retransmit a control frame
- * @data: pointer to our gsm object
- *
- * Called off the T2 timer expiry in order to retransmit control frames
- * that have been lost in the system somewhere. The control_lock protects
- * us from colliding with another sender or a receive completion event.
- * In that situation the timer may still occur in a small window but
- * gsm->pending_cmd will be NULL and we just let the timer expire.
- */
-
-static void gsm_control_retransmit(unsigned long data)
-{
- struct gsm_mux *gsm = (struct gsm_mux *)data;
- struct gsm_control *ctrl;
- unsigned long flags;
- spin_lock_irqsave(&gsm->control_lock, flags);
- ctrl = gsm->pending_cmd;
- if (ctrl) {
- gsm->cretries--;
- if (gsm->cretries == 0) {
- gsm->pending_cmd = NULL;
- ctrl->error = -ETIMEDOUT;
- ctrl->done = 1;
- spin_unlock_irqrestore(&gsm->control_lock, flags);
- wake_up(&gsm->event);
- return;
- }
- gsm_control_transmit(gsm, ctrl);
- mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
- }
- spin_unlock_irqrestore(&gsm->control_lock, flags);
-}
-
-/**
- * gsm_control_send - send a control frame on DLCI 0
- * @gsm: the GSM channel
- * @command: command to send including CR bit
- * @data: bytes of data (must be kmalloced)
- * @len: length of the block to send
- *
- * Queue and dispatch a control command. Only one command can be
- * active at a time. In theory more can be outstanding but the matching
- * gets really complicated so for now stick to one outstanding.
- */
-
-static struct gsm_control *gsm_control_send(struct gsm_mux *gsm,
- unsigned int command, u8 *data, int clen)
-{
- struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control),
- GFP_KERNEL);
- unsigned long flags;
- if (ctrl == NULL)
- return NULL;
-retry:
- wait_event(gsm->event, gsm->pending_cmd == NULL);
- spin_lock_irqsave(&gsm->control_lock, flags);
- if (gsm->pending_cmd != NULL) {
- spin_unlock_irqrestore(&gsm->control_lock, flags);
- goto retry;
- }
- ctrl->cmd = command;
- ctrl->data = data;
- ctrl->len = clen;
- gsm->pending_cmd = ctrl;
- gsm->cretries = gsm->n2;
- mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
- gsm_control_transmit(gsm, ctrl);
- spin_unlock_irqrestore(&gsm->control_lock, flags);
- return ctrl;
-}
-
-/**
- * gsm_control_wait - wait for a control to finish
- * @gsm: GSM mux
- * @control: control we are waiting on
- *
- * Waits for the control to complete or time out. Frees any used
- * resources and returns 0 for success, or an error if the remote
- * rejected or ignored the request.
- */
-
-static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control)
-{
- int err;
- wait_event(gsm->event, control->done == 1);
- err = control->error;
- kfree(control);
- return err;
-}
-
-
-/*
- * DLCI level handling: Needs krefs
- */
-
-/*
- * State transitions and timers
- */
-
-/**
- * gsm_dlci_close - a DLCI has closed
- * @dlci: DLCI that closed
- *
- * Perform processing when moving a DLCI into closed state. If there
- * is an attached tty this is hung up
- */
-
-static void gsm_dlci_close(struct gsm_dlci *dlci)
-{
- del_timer(&dlci->t1);
- if (debug & 8)
- printk("DLCI %d goes closed.\n", dlci->addr);
- dlci->state = DLCI_CLOSED;
- if (dlci->addr != 0) {
- struct tty_struct *tty = tty_port_tty_get(&dlci->port);
- if (tty) {
- tty_hangup(tty);
- tty_kref_put(tty);
- }
- kfifo_reset(dlci->fifo);
- } else
- dlci->gsm->dead = 1;
- wake_up(&dlci->gsm->event);
- /* A DLCI 0 close is a MUX termination so we need to kick that
- back to userspace somehow */
-}
-
-/**
- * gsm_dlci_open - a DLCI has opened
- * @dlci: DLCI that opened
- *
- * Perform processing when moving a DLCI into open state.
- */
-
-static void gsm_dlci_open(struct gsm_dlci *dlci)
-{
- /* Note that SABM UA .. SABM UA first UA lost can mean that we go
- open -> open */
- del_timer(&dlci->t1);
- /* This will let a tty open continue */
- dlci->state = DLCI_OPEN;
- if (debug & 8)
- printk("DLCI %d goes open.\n", dlci->addr);
- wake_up(&dlci->gsm->event);
-}
-
-/**
- * gsm_dlci_t1 - T1 timer expiry
- * @dlci: DLCI that opened
- *
- * The T1 timer handles retransmits of control frames (essentially of
- * SABM and DISC). We resend the command until the retry count runs out
- * in which case an opening port goes back to closed and a closing port
- * is simply put into closed state (any further frames from the other
- * end will get a DM response)
- */
-
-static void gsm_dlci_t1(unsigned long data)
-{
- struct gsm_dlci *dlci = (struct gsm_dlci *)data;
- struct gsm_mux *gsm = dlci->gsm;
-
- switch (dlci->state) {
- case DLCI_OPENING:
- dlci->retries--;
- if (dlci->retries) {
- gsm_command(dlci->gsm, dlci->addr, SABM|PF);
- mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
- } else
- gsm_dlci_close(dlci);
- break;
- case DLCI_CLOSING:
- dlci->retries--;
- if (dlci->retries) {
- gsm_command(dlci->gsm, dlci->addr, DISC|PF);
- mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
- } else
- gsm_dlci_close(dlci);
- break;
- }
-}
-
-/**
- * gsm_dlci_begin_open - start channel open procedure
- * @dlci: DLCI to open
- *
- * Commence opening a DLCI from the Linux side. We issue SABM messages
- * to the modem which should then reply with a UA, at which point we
- * will move into open state. Opening is done asynchronously with retry
- * running off timers and the responses.
- */
-
-static void gsm_dlci_begin_open(struct gsm_dlci *dlci)
-{
- struct gsm_mux *gsm = dlci->gsm;
- if (dlci->state == DLCI_OPEN || dlci->state == DLCI_OPENING)
- return;
- dlci->retries = gsm->n2;
- dlci->state = DLCI_OPENING;
- gsm_command(dlci->gsm, dlci->addr, SABM|PF);
- mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
-}
-
-/**
- * gsm_dlci_begin_close - start channel open procedure
- * @dlci: DLCI to open
- *
- * Commence closing a DLCI from the Linux side. We issue DISC messages
- * to the modem which should then reply with a UA, at which point we
- * will move into closed state. Closing is done asynchronously with retry
- * off timers. We may also receive a DM reply from the other end which
- * indicates the channel was already closed.
- */
-
-static void gsm_dlci_begin_close(struct gsm_dlci *dlci)
-{
- struct gsm_mux *gsm = dlci->gsm;
- if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING)
- return;
- dlci->retries = gsm->n2;
- dlci->state = DLCI_CLOSING;
- gsm_command(dlci->gsm, dlci->addr, DISC|PF);
- mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
-}
-
-/**
- * gsm_dlci_data - data arrived
- * @dlci: channel
- * @data: block of bytes received
- * @len: length of received block
- *
- * A UI or UIH frame has arrived which contains data for a channel
- * other than the control channel. If the relevant virtual tty is
- * open we shovel the bits down it, if not we drop them.
- */
-
-static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len)
-{
- /* krefs .. */
- struct tty_port *port = &dlci->port;
- struct tty_struct *tty = tty_port_tty_get(port);
- unsigned int modem = 0;
-
- if (debug & 16)
- printk("%d bytes for tty %p\n", len, tty);
- if (tty) {
- switch (dlci->adaption) {
- /* Unsupported types */
- /* Packetised interruptible data */
- case 4:
- break;
- /* Packetised uininterruptible voice/data */
- case 3:
- break;
- /* Asynchronous serial with line state in each frame */
- case 2:
- while (gsm_read_ea(&modem, *data++) == 0) {
- len--;
- if (len == 0)
- return;
- }
- gsm_process_modem(tty, dlci, modem);
- /* Line state will go via DLCI 0 controls only */
- case 1:
- default:
- tty_insert_flip_string(tty, data, len);
- tty_flip_buffer_push(tty);
- }
- tty_kref_put(tty);
- }
-}
-
-/**
- * gsm_dlci_control - data arrived on control channel
- * @dlci: channel
- * @data: block of bytes received
- * @len: length of received block
- *
- * A UI or UIH frame has arrived which contains data for DLCI 0 the
- * control channel. This should contain a command EA followed by
- * control data bytes. The command EA contains a command/response bit
- * and we divide up the work accordingly.
- */
-
-static void gsm_dlci_command(struct gsm_dlci *dlci, u8 *data, int len)
-{
- /* See what command is involved */
- unsigned int command = 0;
- while (len-- > 0) {
- if (gsm_read_ea(&command, *data++) == 1) {
- int clen = *data++;
- len--;
- /* FIXME: this is properly an EA */
- clen >>= 1;
- /* Malformed command ? */
- if (clen > len)
- return;
- if (command & 1)
- gsm_control_message(dlci->gsm, command,
- data, clen);
- else
- gsm_control_response(dlci->gsm, command,
- data, clen);
- return;
- }
- }
-}
-
-/*
- * Allocate/Free DLCI channels
- */
-
-/**
- * gsm_dlci_alloc - allocate a DLCI
- * @gsm: GSM mux
- * @addr: address of the DLCI
- *
- * Allocate and install a new DLCI object into the GSM mux.
- *
- * FIXME: review locking races
- */
-
-static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr)
-{
- struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC);
- if (dlci == NULL)
- return NULL;
- spin_lock_init(&dlci->lock);
- dlci->fifo = &dlci->_fifo;
- if (kfifo_alloc(&dlci->_fifo, 4096, GFP_KERNEL) < 0) {
- kfree(dlci);
- return NULL;
- }
-
- skb_queue_head_init(&dlci->skb_list);
- init_timer(&dlci->t1);
- dlci->t1.function = gsm_dlci_t1;
- dlci->t1.data = (unsigned long)dlci;
- tty_port_init(&dlci->port);
- dlci->port.ops = &gsm_port_ops;
- dlci->gsm = gsm;
- dlci->addr = addr;
- dlci->adaption = gsm->adaption;
- dlci->state = DLCI_CLOSED;
- if (addr)
- dlci->data = gsm_dlci_data;
- else
- dlci->data = gsm_dlci_command;
- gsm->dlci[addr] = dlci;
- return dlci;
-}
-
-/**
- * gsm_dlci_free - release DLCI
- * @dlci: DLCI to destroy
- *
- * Free up a DLCI. Currently to keep the lifetime rules sane we only
- * clean up DLCI objects when the MUX closes rather than as the port
- * is closed down on both the tty and mux levels.
- *
- * Can sleep.
- */
-static void gsm_dlci_free(struct gsm_dlci *dlci)
-{
- struct tty_struct *tty = tty_port_tty_get(&dlci->port);
- if (tty) {
- tty_vhangup(tty);
- tty_kref_put(tty);
- }
- del_timer_sync(&dlci->t1);
- dlci->gsm->dlci[dlci->addr] = NULL;
- kfifo_free(dlci->fifo);
- kfree(dlci);
-}
-
-
-/*
- * LAPBish link layer logic
- */
-
-/**
- * gsm_queue - a GSM frame is ready to process
- * @gsm: pointer to our gsm mux
- *
- * At this point in time a frame has arrived and been demangled from
- * the line encoding. All the differences between the encodings have
- * been handled below us and the frame is unpacked into the structures.
- * The fcs holds the header FCS but any data FCS must be added here.
- */
-
-static void gsm_queue(struct gsm_mux *gsm)
-{
- struct gsm_dlci *dlci;
- u8 cr;
- int address;
- /* We have to sneak a look at the packet body to do the FCS.
- A somewhat layering violation in the spec */
-
- if ((gsm->control & ~PF) == UI)
- gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len);
- if (gsm->fcs != GOOD_FCS) {
- gsm->bad_fcs++;
- if (debug & 4)
- printk("BAD FCS %02x\n", gsm->fcs);
- return;
- }
- address = gsm->address >> 1;
- if (address >= NUM_DLCI)
- goto invalid;
-
- cr = gsm->address & 1; /* C/R bit */
-
- gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len);
-
- cr ^= 1 - gsm->initiator; /* Flip so 1 always means command */
- dlci = gsm->dlci[address];
-
- switch (gsm->control) {
- case SABM|PF:
- if (cr == 0)
- goto invalid;
- if (dlci == NULL)
- dlci = gsm_dlci_alloc(gsm, address);
- if (dlci == NULL)
- return;
- if (dlci->dead)
- gsm_response(gsm, address, DM);
- else {
- gsm_response(gsm, address, UA);
- gsm_dlci_open(dlci);
- }
- break;
- case DISC|PF:
- if (cr == 0)
- goto invalid;
- if (dlci == NULL || dlci->state == DLCI_CLOSED) {
- gsm_response(gsm, address, DM);
- return;
- }
- /* Real close complete */
- gsm_response(gsm, address, UA);
- gsm_dlci_close(dlci);
- break;
- case UA:
- case UA|PF:
- if (cr == 0 || dlci == NULL)
- break;
- switch (dlci->state) {
- case DLCI_CLOSING:
- gsm_dlci_close(dlci);
- break;
- case DLCI_OPENING:
- gsm_dlci_open(dlci);
- break;
- }
- break;
- case DM: /* DM can be valid unsolicited */
- case DM|PF:
- if (cr)
- goto invalid;
- if (dlci == NULL)
- return;
- gsm_dlci_close(dlci);
- break;
- case UI:
- case UI|PF:
- case UIH:
- case UIH|PF:
-#if 0
- if (cr)
- goto invalid;
-#endif
- if (dlci == NULL || dlci->state != DLCI_OPEN) {
- gsm_command(gsm, address, DM|PF);
- return;
- }
- dlci->data(dlci, gsm->buf, gsm->len);
- break;
- default:
- goto invalid;
- }
- return;
-invalid:
- gsm->malformed++;
- return;
-}
-
-
-/**
- * gsm0_receive - perform processing for non-transparency
- * @gsm: gsm data for this ldisc instance
- * @c: character
- *
- * Receive bytes in gsm mode 0
- */
-
-static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
-{
- switch (gsm->state) {
- case GSM_SEARCH: /* SOF marker */
- if (c == GSM0_SOF) {
- gsm->state = GSM_ADDRESS;
- gsm->address = 0;
- gsm->len = 0;
- gsm->fcs = INIT_FCS;
- }
- break; /* Address EA */
- case GSM_ADDRESS:
- gsm->fcs = gsm_fcs_add(gsm->fcs, c);
- if (gsm_read_ea(&gsm->address, c))
- gsm->state = GSM_CONTROL;
- break;
- case GSM_CONTROL: /* Control Byte */
- gsm->fcs = gsm_fcs_add(gsm->fcs, c);
- gsm->control = c;
- gsm->state = GSM_LEN;
- break;
- case GSM_LEN: /* Length EA */
- gsm->fcs = gsm_fcs_add(gsm->fcs, c);
- if (gsm_read_ea(&gsm->len, c)) {
- if (gsm->len > gsm->mru) {
- gsm->bad_size++;
- gsm->state = GSM_SEARCH;
- break;
- }
- gsm->count = 0;
- gsm->state = GSM_DATA;
- }
- break;
- case GSM_DATA: /* Data */
- gsm->buf[gsm->count++] = c;
- if (gsm->count == gsm->len)
- gsm->state = GSM_FCS;
- break;
- case GSM_FCS: /* FCS follows the packet */
- gsm->fcs = c;
- gsm_queue(gsm);
- /* And then back for the next frame */
- gsm->state = GSM_SEARCH;
- break;
- }
-}
-
-/**
- * gsm0_receive - perform processing for non-transparency
- * @gsm: gsm data for this ldisc instance
- * @c: character
- *
- * Receive bytes in mode 1 (Advanced option)
- */
-
-static void gsm1_receive(struct gsm_mux *gsm, unsigned char c)
-{
- if (c == GSM1_SOF) {
- /* EOF is only valid in frame if we have got to the data state
- and received at least one byte (the FCS) */
- if (gsm->state == GSM_DATA && gsm->count) {
- /* Extract the FCS */
- gsm->count--;
- gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]);
- gsm->len = gsm->count;
- gsm_queue(gsm);
- gsm->state = GSM_START;
- return;
- }
- /* Any partial frame was a runt so go back to start */
- if (gsm->state != GSM_START) {
- gsm->malformed++;
- gsm->state = GSM_START;
- }
- /* A SOF in GSM_START means we are still reading idling or
- framing bytes */
- return;
- }
-
- if (c == GSM1_ESCAPE) {
- gsm->escape = 1;
- return;
- }
-
- /* Only an unescaped SOF gets us out of GSM search */
- if (gsm->state == GSM_SEARCH)
- return;
-
- if (gsm->escape) {
- c ^= GSM1_ESCAPE_BITS;
- gsm->escape = 0;
- }
- switch (gsm->state) {
- case GSM_START: /* First byte after SOF */
- gsm->address = 0;
- gsm->state = GSM_ADDRESS;
- gsm->fcs = INIT_FCS;
- /* Drop through */
- case GSM_ADDRESS: /* Address continuation */
- gsm->fcs = gsm_fcs_add(gsm->fcs, c);
- if (gsm_read_ea(&gsm->address, c))
- gsm->state = GSM_CONTROL;
- break;
- case GSM_CONTROL: /* Control Byte */
- gsm->fcs = gsm_fcs_add(gsm->fcs, c);
- gsm->control = c;
- gsm->count = 0;
- gsm->state = GSM_DATA;
- break;
- case GSM_DATA: /* Data */
- if (gsm->count > gsm->mru ) { /* Allow one for the FCS */
- gsm->state = GSM_OVERRUN;
- gsm->bad_size++;
- } else
- gsm->buf[gsm->count++] = c;
- break;
- case GSM_OVERRUN: /* Over-long - eg a dropped SOF */
- break;
- }
-}
-
-/**
- * gsm_error - handle tty error
- * @gsm: ldisc data
- * @data: byte received (may be invalid)
- * @flag: error received
- *
- * Handle an error in the receipt of data for a frame. Currently we just
- * go back to hunting for a SOF.
- *
- * FIXME: better diagnostics ?
- */
-
-static void gsm_error(struct gsm_mux *gsm,
- unsigned char data, unsigned char flag)
-{
- gsm->state = GSM_SEARCH;
- gsm->io_error++;
-}
-
-/**
- * gsm_cleanup_mux - generic GSM protocol cleanup
- * @gsm: our mux
- *
- * Clean up the bits of the mux which are the same for all framing
- * protocols. Remove the mux from the mux table, stop all the timers
- * and then shut down each device hanging up the channels as we go.
- */
-
-void gsm_cleanup_mux(struct gsm_mux *gsm)
-{
- int i;
- struct gsm_dlci *dlci = gsm->dlci[0];
- struct gsm_msg *txq;
-
- gsm->dead = 1;
-
- spin_lock(&gsm_mux_lock);
- for (i = 0; i < MAX_MUX; i++) {
- if (gsm_mux[i] == gsm) {
- gsm_mux[i] = NULL;
- break;
- }
- }
- spin_unlock(&gsm_mux_lock);
- WARN_ON(i == MAX_MUX);
-
- del_timer_sync(&gsm->t2_timer);
- /* Now we are sure T2 has stopped */
- if (dlci) {
- dlci->dead = 1;
- gsm_dlci_begin_close(dlci);
- wait_event_interruptible(gsm->event,
- dlci->state == DLCI_CLOSED);
- }
- /* Free up any link layer users */
- for (i = 0; i < NUM_DLCI; i++)
- if (gsm->dlci[i])
- gsm_dlci_free(gsm->dlci[i]);
- /* Now wipe the queues */
- for (txq = gsm->tx_head; txq != NULL; txq = gsm->tx_head) {
- gsm->tx_head = txq->next;
- kfree(txq);
- }
- gsm->tx_tail = NULL;
-}
-EXPORT_SYMBOL_GPL(gsm_cleanup_mux);
-
-/**
- * gsm_activate_mux - generic GSM setup
- * @gsm: our mux
- *
- * Set up the bits of the mux which are the same for all framing
- * protocols. Add the mux to the mux table so it can be opened and
- * finally kick off connecting to DLCI 0 on the modem.
- */
-
-int gsm_activate_mux(struct gsm_mux *gsm)
-{
- struct gsm_dlci *dlci;
- int i = 0;
-
- init_timer(&gsm->t2_timer);
- gsm->t2_timer.function = gsm_control_retransmit;
- gsm->t2_timer.data = (unsigned long)gsm;
- init_waitqueue_head(&gsm->event);
- spin_lock_init(&gsm->control_lock);
- spin_lock_init(&gsm->tx_lock);
-
- if (gsm->encoding == 0)
- gsm->receive = gsm0_receive;
- else
- gsm->receive = gsm1_receive;
- gsm->error = gsm_error;
-
- spin_lock(&gsm_mux_lock);
- for (i = 0; i < MAX_MUX; i++) {
- if (gsm_mux[i] == NULL) {
- gsm_mux[i] = gsm;
- break;
- }
- }
- spin_unlock(&gsm_mux_lock);
- if (i == MAX_MUX)
- return -EBUSY;
-
- dlci = gsm_dlci_alloc(gsm, 0);
- if (dlci == NULL)
- return -ENOMEM;
- gsm->dead = 0; /* Tty opens are now permissible */
- return 0;
-}
-EXPORT_SYMBOL_GPL(gsm_activate_mux);
-
-/**
- * gsm_free_mux - free up a mux
- * @mux: mux to free
- *
- * Dispose of allocated resources for a dead mux. No refcounting
- * at present so the mux must be truely dead.
- */
-void gsm_free_mux(struct gsm_mux *gsm)
-{
- kfree(gsm->txframe);
- kfree(gsm->buf);
- kfree(gsm);
-}
-EXPORT_SYMBOL_GPL(gsm_free_mux);
-
-/**
- * gsm_alloc_mux - allocate a mux
- *
- * Creates a new mux ready for activation.
- */
-
-struct gsm_mux *gsm_alloc_mux(void)
-{
- struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL);
- if (gsm == NULL)
- return NULL;
- gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL);
- if (gsm->buf == NULL) {
- kfree(gsm);
- return NULL;
- }
- gsm->txframe = kmalloc(2 * MAX_MRU + 2, GFP_KERNEL);
- if (gsm->txframe == NULL) {
- kfree(gsm->buf);
- kfree(gsm);
- return NULL;
- }
- spin_lock_init(&gsm->lock);
-
- gsm->t1 = T1;
- gsm->t2 = T2;
- gsm->n2 = N2;
- gsm->ftype = UIH;
- gsm->initiator = 0;
- gsm->adaption = 1;
- gsm->encoding = 1;
- gsm->mru = 64; /* Default to encoding 1 so these should be 64 */
- gsm->mtu = 64;
- gsm->dead = 1; /* Avoid early tty opens */
-
- return gsm;
-}
-EXPORT_SYMBOL_GPL(gsm_alloc_mux);
-
-
-
-
-/**
- * gsmld_output - write to link
- * @gsm: our mux
- * @data: bytes to output
- * @len: size
- *
- * Write a block of data from the GSM mux to the data channel. This
- * will eventually be serialized from above but at the moment isn't.
- */
-
-static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
-{
- if (tty_write_room(gsm->tty) < len) {
- set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags);
- return -ENOSPC;
- }
- if (debug & 4) {
- printk("-->%d bytes out\n", len);
- hex_packet(data, len);
- }
- gsm->tty->ops->write(gsm->tty, data, len);
- return len;
-}
-
-/**
- * gsmld_attach_gsm - mode set up
- * @tty: our tty structure
- * @gsm: our mux
- *
- * Set up the MUX for basic mode and commence connecting to the
- * modem. Currently called from the line discipline set up but
- * will need moving to an ioctl path.
- */
-
-static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
-{
- int ret;
-
- gsm->tty = tty_kref_get(tty);
- gsm->output = gsmld_output;
- ret = gsm_activate_mux(gsm);
- if (ret != 0)
- tty_kref_put(gsm->tty);
- return ret;
-}
-
-
-/**
- * gsmld_detach_gsm - stop doing 0710 mux
- * @tty: tty atttached to the mux
- * @gsm: mux
- *
- * Shutdown and then clean up the resources used by the line discipline
- */
-
-static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
-{
- WARN_ON(tty != gsm->tty);
- gsm_cleanup_mux(gsm);
- tty_kref_put(gsm->tty);
- gsm->tty = NULL;
-}
-
-static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
- char *fp, int count)
-{
- struct gsm_mux *gsm = tty->disc_data;
- const unsigned char *dp;
- char *f;
- int i;
- char buf[64];
- char flags;
-
- if (debug & 4) {
- printk("Inbytes %dd\n", count);
- hex_packet(cp, count);
- }
-
- for (i = count, dp = cp, f = fp; i; i--, dp++) {
- flags = *f++;
- switch (flags) {
- case TTY_NORMAL:
- gsm->receive(gsm, *dp);
- break;
- case TTY_OVERRUN:
- case TTY_BREAK:
- case TTY_PARITY:
- case TTY_FRAME:
- gsm->error(gsm, *dp, flags);
- break;
- default:
- printk(KERN_ERR "%s: unknown flag %d\n",
- tty_name(tty, buf), flags);
- break;
- }
- }
- /* FASYNC if needed ? */
- /* If clogged call tty_throttle(tty); */
-}
-
-/**
- * gsmld_chars_in_buffer - report available bytes
- * @tty: tty device
- *
- * Report the number of characters buffered to be delivered to user
- * at this instant in time.
- *
- * Locking: gsm lock
- */
-
-static ssize_t gsmld_chars_in_buffer(struct tty_struct *tty)
-{
- return 0;
-}
-
-/**
- * gsmld_flush_buffer - clean input queue
- * @tty: terminal device
- *
- * Flush the input buffer. Called when the line discipline is
- * being closed, when the tty layer wants the buffer flushed (eg
- * at hangup).
- */
-
-static void gsmld_flush_buffer(struct tty_struct *tty)
-{
-}
-
-/**
- * gsmld_close - close the ldisc for this tty
- * @tty: device
- *
- * Called from the terminal layer when this line discipline is
- * being shut down, either because of a close or becsuse of a
- * discipline change. The function will not be called while other
- * ldisc methods are in progress.
- */
-
-static void gsmld_close(struct tty_struct *tty)
-{
- struct gsm_mux *gsm = tty->disc_data;
-
- gsmld_detach_gsm(tty, gsm);
-
- gsmld_flush_buffer(tty);
- /* Do other clean up here */
- gsm_free_mux(gsm);
-}
-
-/**
- * gsmld_open - open an ldisc
- * @tty: terminal to open
- *
- * Called when this line discipline is being attached to the
- * terminal device. Can sleep. Called serialized so that no
- * other events will occur in parallel. No further open will occur
- * until a close.
- */
-
-static int gsmld_open(struct tty_struct *tty)
-{
- struct gsm_mux *gsm;
-
- if (tty->ops->write == NULL)
- return -EINVAL;
-
- /* Attach our ldisc data */
- gsm = gsm_alloc_mux();
- if (gsm == NULL)
- return -ENOMEM;
-
- tty->disc_data = gsm;
- tty->receive_room = 65536;
-
- /* Attach the initial passive connection */
- gsm->encoding = 1;
- return gsmld_attach_gsm(tty, gsm);
-}
-
-/**
- * gsmld_write_wakeup - asynchronous I/O notifier
- * @tty: tty device
- *
- * Required for the ptys, serial driver etc. since processes
- * that attach themselves to the master and rely on ASYNC
- * IO must be woken up
- */
-
-static void gsmld_write_wakeup(struct tty_struct *tty)
-{
- struct gsm_mux *gsm = tty->disc_data;
- unsigned long flags;
-
- /* Queue poll */
- clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- gsm_data_kick(gsm);
- if (gsm->tx_bytes < TX_THRESH_LO) {
- spin_lock_irqsave(&gsm->tx_lock, flags);
- gsm_dlci_data_sweep(gsm);
- spin_unlock_irqrestore(&gsm->tx_lock, flags);
- }
-}
-
-/**
- * gsmld_read - read function for tty
- * @tty: tty device
- * @file: file object
- * @buf: userspace buffer pointer
- * @nr: size of I/O
- *
- * Perform reads for the line discipline. We are guaranteed that the
- * line discipline will not be closed under us but we may get multiple
- * parallel readers and must handle this ourselves. We may also get
- * a hangup. Always called in user context, may sleep.
- *
- * This code must be sure never to sleep through a hangup.
- */
-
-static ssize_t gsmld_read(struct tty_struct *tty, struct file *file,
- unsigned char __user *buf, size_t nr)
-{
- return -EOPNOTSUPP;
-}
-
-/**
- * gsmld_write - write function for tty
- * @tty: tty device
- * @file: file object
- * @buf: userspace buffer pointer
- * @nr: size of I/O
- *
- * Called when the owner of the device wants to send a frame
- * itself (or some other control data). The data is transferred
- * as-is and must be properly framed and checksummed as appropriate
- * by userspace. Frames are either sent whole or not at all as this
- * avoids pain user side.
- */
-
-static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
- const unsigned char *buf, size_t nr)
-{
- int space = tty_write_room(tty);
- if (space >= nr)
- return tty->ops->write(tty, buf, nr);
- set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- return -ENOBUFS;
-}
-
-/**
- * gsmld_poll - poll method for N_GSM0710
- * @tty: terminal device
- * @file: file accessing it
- * @wait: poll table
- *
- * Called when the line discipline is asked to poll() for data or
- * for special events. This code is not serialized with respect to
- * other events save open/close.
- *
- * This code must be sure never to sleep through a hangup.
- * Called without the kernel lock held - fine
- */
-
-static unsigned int gsmld_poll(struct tty_struct *tty, struct file *file,
- poll_table *wait)
-{
- unsigned int mask = 0;
- struct gsm_mux *gsm = tty->disc_data;
-
- poll_wait(file, &tty->read_wait, wait);
- poll_wait(file, &tty->write_wait, wait);
- if (tty_hung_up_p(file))
- mask |= POLLHUP;
- if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0)
- mask |= POLLOUT | POLLWRNORM;
- if (gsm->dead)
- mask |= POLLHUP;
- return mask;
-}
-
-static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm,
- struct gsm_config *c)
-{
- int need_close = 0;
- int need_restart = 0;
-
- /* Stuff we don't support yet - UI or I frame transport, windowing */
- if ((c->adaption !=1 && c->adaption != 2) || c->k)
- return -EOPNOTSUPP;
- /* Check the MRU/MTU range looks sane */
- if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8)
- return -EINVAL;
- if (c->n2 < 3)
- return -EINVAL;
- if (c->encapsulation > 1) /* Basic, advanced, no I */
- return -EINVAL;
- if (c->initiator > 1)
- return -EINVAL;
- if (c->i == 0 || c->i > 2) /* UIH and UI only */
- return -EINVAL;
- /*
- * See what is needed for reconfiguration
- */
-
- /* Timing fields */
- if (c->t1 != 0 && c->t1 != gsm->t1)
- need_restart = 1;
- if (c->t2 != 0 && c->t2 != gsm->t2)
- need_restart = 1;
- if (c->encapsulation != gsm->encoding)
- need_restart = 1;
- if (c->adaption != gsm->adaption)
- need_restart = 1;
- /* Requires care */
- if (c->initiator != gsm->initiator)
- need_close = 1;
- if (c->mru != gsm->mru)
- need_restart = 1;
- if (c->mtu != gsm->mtu)
- need_restart = 1;
-
- /*
- * Close down what is needed, restart and initiate the new
- * configuration
- */
-
- if (need_close || need_restart) {
- gsm_dlci_begin_close(gsm->dlci[0]);
- /* This will timeout if the link is down due to N2 expiring */
- wait_event_interruptible(gsm->event,
- gsm->dlci[0]->state == DLCI_CLOSED);
- if (signal_pending(current))
- return -EINTR;
- }
- if (need_restart)
- gsm_cleanup_mux(gsm);
-
- gsm->initiator = c->initiator;
- gsm->mru = c->mru;
- gsm->encoding = c->encapsulation;
- gsm->adaption = c->adaption;
-
- if (c->i == 1)
- gsm->ftype = UIH;
- else if (c->i == 2)
- gsm->ftype = UI;
-
- if (c->t1)
- gsm->t1 = c->t1;
- if (c->t2)
- gsm->t2 = c->t2;
-
- /* FIXME: We need to separate activation/deactivation from adding
- and removing from the mux array */
- if (need_restart)
- gsm_activate_mux(gsm);
- if (gsm->initiator && need_close)
- gsm_dlci_begin_open(gsm->dlci[0]);
- return 0;
-}
-
-static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- struct gsm_config c;
- struct gsm_mux *gsm = tty->disc_data;
-
- switch (cmd) {
- case GSMIOC_GETCONF:
- memset(&c, 0, sizeof(c));
- c.adaption = gsm->adaption;
- c.encapsulation = gsm->encoding;
- c.initiator = gsm->initiator;
- c.t1 = gsm->t1;
- c.t2 = gsm->t2;
- c.t3 = 0; /* Not supported */
- c.n2 = gsm->n2;
- if (gsm->ftype == UIH)
- c.i = 1;
- else
- c.i = 2;
- printk("Ftype %d i %d\n", gsm->ftype, c.i);
- c.mru = gsm->mru;
- c.mtu = gsm->mtu;
- c.k = 0;
- if (copy_to_user((void *)arg, &c, sizeof(c)))
- return -EFAULT;
- return 0;
- case GSMIOC_SETCONF:
- if (copy_from_user(&c, (void *)arg, sizeof(c)))
- return -EFAULT;
- return gsmld_config(tty, gsm, &c);
- default:
- return n_tty_ioctl_helper(tty, file, cmd, arg);
- }
-}
-
-
-/* Line discipline for real tty */
-struct tty_ldisc_ops tty_ldisc_packet = {
- .owner = THIS_MODULE,
- .magic = TTY_LDISC_MAGIC,
- .name = "n_gsm",
- .open = gsmld_open,
- .close = gsmld_close,
- .flush_buffer = gsmld_flush_buffer,
- .chars_in_buffer = gsmld_chars_in_buffer,
- .read = gsmld_read,
- .write = gsmld_write,
- .ioctl = gsmld_ioctl,
- .poll = gsmld_poll,
- .receive_buf = gsmld_receive_buf,
- .write_wakeup = gsmld_write_wakeup
-};
-
-/*
- * Virtual tty side
- */
-
-#define TX_SIZE 512
-
-static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk)
-{
- u8 modembits[5];
- struct gsm_control *ctrl;
- int len = 2;
-
- if (brk)
- len++;
-
- modembits[0] = len << 1 | EA; /* Data bytes */
- modembits[1] = dlci->addr << 2 | 3; /* DLCI, EA, 1 */
- modembits[2] = gsm_encode_modem(dlci) << 1 | EA;
- if (brk)
- modembits[3] = brk << 4 | 2 | EA; /* Valid, EA */
- ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len + 1);
- if (ctrl == NULL)
- return -ENOMEM;
- return gsm_control_wait(dlci->gsm, ctrl);
-}
-
-static int gsm_carrier_raised(struct tty_port *port)
-{
- struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
- /* Not yet open so no carrier info */
- if (dlci->state != DLCI_OPEN)
- return 0;
- if (debug & 2)
- return 1;
- return dlci->modem_rx & TIOCM_CD;
-}
-
-static void gsm_dtr_rts(struct tty_port *port, int onoff)
-{
- struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
- unsigned int modem_tx = dlci->modem_tx;
- if (onoff)
- modem_tx |= TIOCM_DTR | TIOCM_RTS;
- else
- modem_tx &= ~(TIOCM_DTR | TIOCM_RTS);
- if (modem_tx != dlci->modem_tx) {
- dlci->modem_tx = modem_tx;
- gsmtty_modem_update(dlci, 0);
- }
-}
-
-static const struct tty_port_operations gsm_port_ops = {
- .carrier_raised = gsm_carrier_raised,
- .dtr_rts = gsm_dtr_rts,
-};
-
-
-static int gsmtty_open(struct tty_struct *tty, struct file *filp)
-{
- struct gsm_mux *gsm;
- struct gsm_dlci *dlci;
- struct tty_port *port;
- unsigned int line = tty->index;
- unsigned int mux = line >> 6;
-
- line = line & 0x3F;
-
- if (mux >= MAX_MUX)
- return -ENXIO;
- /* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */
- if (gsm_mux[mux] == NULL)
- return -EUNATCH;
- if (line == 0 || line > 61) /* 62/63 reserved */
- return -ECHRNG;
- gsm = gsm_mux[mux];
- if (gsm->dead)
- return -EL2HLT;
- dlci = gsm->dlci[line];
- if (dlci == NULL)
- dlci = gsm_dlci_alloc(gsm, line);
- if (dlci == NULL)
- return -ENOMEM;
- port = &dlci->port;
- port->count++;
- tty->driver_data = dlci;
- tty_port_tty_set(port, tty);
-
- dlci->modem_rx = 0;
- /* We could in theory open and close before we wait - eg if we get
- a DM straight back. This is ok as that will have caused a hangup */
- set_bit(ASYNCB_INITIALIZED, &port->flags);
- /* Start sending off SABM messages */
- gsm_dlci_begin_open(dlci);
- /* And wait for virtual carrier */
- return tty_port_block_til_ready(port, tty, filp);
-}
-
-static void gsmtty_close(struct tty_struct *tty, struct file *filp)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- if (dlci == NULL)
- return;
- if (tty_port_close_start(&dlci->port, tty, filp) == 0)
- return;
- gsm_dlci_begin_close(dlci);
- tty_port_close_end(&dlci->port, tty);
- tty_port_tty_set(&dlci->port, NULL);
-}
-
-static void gsmtty_hangup(struct tty_struct *tty)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- tty_port_hangup(&dlci->port);
- gsm_dlci_begin_close(dlci);
-}
-
-static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf,
- int len)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- /* Stuff the bytes into the fifo queue */
- int sent = kfifo_in_locked(dlci->fifo, buf, len, &dlci->lock);
- /* Need to kick the channel */
- gsm_dlci_data_kick(dlci);
- return sent;
-}
-
-static int gsmtty_write_room(struct tty_struct *tty)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- return TX_SIZE - kfifo_len(dlci->fifo);
-}
-
-static int gsmtty_chars_in_buffer(struct tty_struct *tty)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- return kfifo_len(dlci->fifo);
-}
-
-static void gsmtty_flush_buffer(struct tty_struct *tty)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- /* Caution needed: If we implement reliable transport classes
- then the data being transmitted can't simply be junked once
- it has first hit the stack. Until then we can just blow it
- away */
- kfifo_reset(dlci->fifo);
- /* Need to unhook this DLCI from the transmit queue logic */
-}
-
-static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout)
-{
- /* The FIFO handles the queue so the kernel will do the right
- thing waiting on chars_in_buffer before calling us. No work
- to do here */
-}
-
-static int gsmtty_tiocmget(struct tty_struct *tty, struct file *filp)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- return dlci->modem_rx;
-}
-
-static int gsmtty_tiocmset(struct tty_struct *tty, struct file *filp,
- unsigned int set, unsigned int clear)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- unsigned int modem_tx = dlci->modem_tx;
-
- modem_tx &= clear;
- modem_tx |= set;
-
- if (modem_tx != dlci->modem_tx) {
- dlci->modem_tx = modem_tx;
- return gsmtty_modem_update(dlci, 0);
- }
- return 0;
-}
-
-
-static int gsmtty_ioctl(struct tty_struct *tty, struct file *filp,
- unsigned int cmd, unsigned long arg)
-{
- return -ENOIOCTLCMD;
-}
-
-static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old)
-{
- /* For the moment its fixed. In actual fact the speed information
- for the virtual channel can be propogated in both directions by
- the RPN control message. This however rapidly gets nasty as we
- then have to remap modem signals each way according to whether
- our virtual cable is null modem etc .. */
- tty_termios_copy_hw(tty->termios, old);
-}
-
-static void gsmtty_throttle(struct tty_struct *tty)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- if (tty->termios->c_cflag & CRTSCTS)
- dlci->modem_tx &= ~TIOCM_DTR;
- dlci->throttled = 1;
- /* Send an MSC with DTR cleared */
- gsmtty_modem_update(dlci, 0);
-}
-
-static void gsmtty_unthrottle(struct tty_struct *tty)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- if (tty->termios->c_cflag & CRTSCTS)
- dlci->modem_tx |= TIOCM_DTR;
- dlci->throttled = 0;
- /* Send an MSC with DTR set */
- gsmtty_modem_update(dlci, 0);
-}
-
-static int gsmtty_break_ctl(struct tty_struct *tty, int state)
-{
- struct gsm_dlci *dlci = tty->driver_data;
- int encode = 0; /* Off */
-
- if (state == -1) /* "On indefinitely" - we can't encode this
- properly */
- encode = 0x0F;
- else if (state > 0) {
- encode = state / 200; /* mS to encoding */
- if (encode > 0x0F)
- encode = 0x0F; /* Best effort */
- }
- return gsmtty_modem_update(dlci, encode);
-}
-
-static struct tty_driver *gsm_tty_driver;
-
-/* Virtual ttys for the demux */
-static const struct tty_operations gsmtty_ops = {
- .open = gsmtty_open,
- .close = gsmtty_close,
- .write = gsmtty_write,
- .write_room = gsmtty_write_room,
- .chars_in_buffer = gsmtty_chars_in_buffer,
- .flush_buffer = gsmtty_flush_buffer,
- .ioctl = gsmtty_ioctl,
- .throttle = gsmtty_throttle,
- .unthrottle = gsmtty_unthrottle,
- .set_termios = gsmtty_set_termios,
- .hangup = gsmtty_hangup,
- .wait_until_sent = gsmtty_wait_until_sent,
- .tiocmget = gsmtty_tiocmget,
- .tiocmset = gsmtty_tiocmset,
- .break_ctl = gsmtty_break_ctl,
-};
-
-
-
-static int __init gsm_init(void)
-{
- /* Fill in our line protocol discipline, and register it */
- int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet);
- if (status != 0) {
- printk(KERN_ERR "n_gsm: can't register line discipline (err = %d)\n", status);
- return status;
- }
-
- gsm_tty_driver = alloc_tty_driver(256);
- if (!gsm_tty_driver) {
- tty_unregister_ldisc(N_GSM0710);
- printk(KERN_ERR "gsm_init: tty allocation failed.\n");
- return -EINVAL;
- }
- gsm_tty_driver->owner = THIS_MODULE;
- gsm_tty_driver->driver_name = "gsmtty";
- gsm_tty_driver->name = "gsmtty";
- gsm_tty_driver->major = 0; /* Dynamic */
- gsm_tty_driver->minor_start = 0;
- gsm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
- gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL;
- gsm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV
- | TTY_DRIVER_HARDWARE_BREAK;
- gsm_tty_driver->init_termios = tty_std_termios;
- /* Fixme */
- gsm_tty_driver->init_termios.c_lflag &= ~ECHO;
- tty_set_operations(gsm_tty_driver, &gsmtty_ops);
-
- spin_lock_init(&gsm_mux_lock);
-
- if (tty_register_driver(gsm_tty_driver)) {
- put_tty_driver(gsm_tty_driver);
- tty_unregister_ldisc(N_GSM0710);
- printk(KERN_ERR "gsm_init: tty registration failed.\n");
- return -EBUSY;
- }
- printk(KERN_INFO "gsm_init: loaded as %d,%d.\n", gsm_tty_driver->major, gsm_tty_driver->minor_start);
- return 0;
-}
-
-static void __exit gsm_exit(void)
-{
- int status = tty_unregister_ldisc(N_GSM0710);
- if (status != 0)
- printk(KERN_ERR "n_gsm: can't unregister line discipline (err = %d)\n", status);
- tty_unregister_driver(gsm_tty_driver);
- put_tty_driver(gsm_tty_driver);
- printk(KERN_INFO "gsm_init: unloaded.\n");
-}
-
-module_init(gsm_init);
-module_exit(gsm_exit);
-
-
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_LDISC(N_GSM0710);
+++ /dev/null
-/* generic HDLC line discipline for Linux
- *
- * Written by Paul Fulghum paulkf@microgate.com
- * for Microgate Corporation
- *
- * Microgate and SyncLink are registered trademarks of Microgate Corporation
- *
- * Adapted from ppp.c, written by Michael Callahan <callahan@maths.ox.ac.uk>,
- * Al Longyear <longyear@netcom.com>,
- * Paul Mackerras <Paul.Mackerras@cs.anu.edu.au>
- *
- * Original release 01/11/99
- *
- * This code is released under the GNU General Public License (GPL)
- *
- * This module implements the tty line discipline N_HDLC for use with
- * tty device drivers that support bit-synchronous HDLC communications.
- *
- * All HDLC data is frame oriented which means:
- *
- * 1. tty write calls represent one complete transmit frame of data
- * The device driver should accept the complete frame or none of
- * the frame (busy) in the write method. Each write call should have
- * a byte count in the range of 2-65535 bytes (2 is min HDLC frame
- * with 1 addr byte and 1 ctrl byte). The max byte count of 65535
- * should include any crc bytes required. For example, when using
- * CCITT CRC32, 4 crc bytes are required, so the maximum size frame
- * the application may transmit is limited to 65531 bytes. For CCITT
- * CRC16, the maximum application frame size would be 65533.
- *
- *
- * 2. receive callbacks from the device driver represents
- * one received frame. The device driver should bypass
- * the tty flip buffer and call the line discipline receive
- * callback directly to avoid fragmenting or concatenating
- * multiple frames into a single receive callback.
- *
- * The HDLC line discipline queues the receive frames in separate
- * buffers so complete receive frames can be returned by the
- * tty read calls.
- *
- * 3. tty read calls returns an entire frame of data or nothing.
- *
- * 4. all send and receive data is considered raw. No processing
- * or translation is performed by the line discipline, regardless
- * of the tty flags
- *
- * 5. When line discipline is queried for the amount of receive
- * data available (FIOC), 0 is returned if no data available,
- * otherwise the count of the next available frame is returned.
- * (instead of the sum of all received frame counts).
- *
- * These conventions allow the standard tty programming interface
- * to be used for synchronous HDLC applications when used with
- * this line discipline (or another line discipline that is frame
- * oriented such as N_PPP).
- *
- * The SyncLink driver (synclink.c) implements both asynchronous
- * (using standard line discipline N_TTY) and synchronous HDLC
- * (using N_HDLC) communications, with the latter using the above
- * conventions.
- *
- * This implementation is very basic and does not maintain
- * any statistics. The main point is to enforce the raw data
- * and frame orientation of HDLC communications.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
- * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#define HDLC_MAGIC 0x239e
-
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/types.h>
-#include <linux/fcntl.h>
-#include <linux/interrupt.h>
-#include <linux/ptrace.h>
-
-#undef VERSION
-#define VERSION(major,minor,patch) (((((major)<<8)+(minor))<<8)+(patch))
-
-#include <linux/poll.h>
-#include <linux/in.h>
-#include <linux/ioctl.h>
-#include <linux/slab.h>
-#include <linux/tty.h>
-#include <linux/errno.h>
-#include <linux/smp_lock.h>
-#include <linux/string.h> /* used in new tty drivers */
-#include <linux/signal.h> /* used in new tty drivers */
-#include <linux/if.h>
-#include <linux/bitops.h>
-
-#include <asm/system.h>
-#include <asm/termios.h>
-#include <asm/uaccess.h>
-
-/*
- * Buffers for individual HDLC frames
- */
-#define MAX_HDLC_FRAME_SIZE 65535
-#define DEFAULT_RX_BUF_COUNT 10
-#define MAX_RX_BUF_COUNT 60
-#define DEFAULT_TX_BUF_COUNT 3
-
-struct n_hdlc_buf {
- struct n_hdlc_buf *link;
- int count;
- char buf[1];
-};
-
-#define N_HDLC_BUF_SIZE (sizeof(struct n_hdlc_buf) + maxframe)
-
-struct n_hdlc_buf_list {
- struct n_hdlc_buf *head;
- struct n_hdlc_buf *tail;
- int count;
- spinlock_t spinlock;
-};
-
-/**
- * struct n_hdlc - per device instance data structure
- * @magic - magic value for structure
- * @flags - miscellaneous control flags
- * @tty - ptr to TTY structure
- * @backup_tty - TTY to use if tty gets closed
- * @tbusy - reentrancy flag for tx wakeup code
- * @woke_up - FIXME: describe this field
- * @tbuf - currently transmitting tx buffer
- * @tx_buf_list - list of pending transmit frame buffers
- * @rx_buf_list - list of received frame buffers
- * @tx_free_buf_list - list unused transmit frame buffers
- * @rx_free_buf_list - list unused received frame buffers
- */
-struct n_hdlc {
- int magic;
- __u32 flags;
- struct tty_struct *tty;
- struct tty_struct *backup_tty;
- int tbusy;
- int woke_up;
- struct n_hdlc_buf *tbuf;
- struct n_hdlc_buf_list tx_buf_list;
- struct n_hdlc_buf_list rx_buf_list;
- struct n_hdlc_buf_list tx_free_buf_list;
- struct n_hdlc_buf_list rx_free_buf_list;
-};
-
-/*
- * HDLC buffer list manipulation functions
- */
-static void n_hdlc_buf_list_init(struct n_hdlc_buf_list *list);
-static void n_hdlc_buf_put(struct n_hdlc_buf_list *list,
- struct n_hdlc_buf *buf);
-static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *list);
-
-/* Local functions */
-
-static struct n_hdlc *n_hdlc_alloc (void);
-
-/* debug level can be set by insmod for debugging purposes */
-#define DEBUG_LEVEL_INFO 1
-static int debuglevel;
-
-/* max frame size for memory allocations */
-static int maxframe = 4096;
-
-/* TTY callbacks */
-
-static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
- __u8 __user *buf, size_t nr);
-static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
- const unsigned char *buf, size_t nr);
-static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg);
-static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
- poll_table *wait);
-static int n_hdlc_tty_open(struct tty_struct *tty);
-static void n_hdlc_tty_close(struct tty_struct *tty);
-static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *cp,
- char *fp, int count);
-static void n_hdlc_tty_wakeup(struct tty_struct *tty);
-
-#define bset(p,b) ((p)[(b) >> 5] |= (1 << ((b) & 0x1f)))
-
-#define tty2n_hdlc(tty) ((struct n_hdlc *) ((tty)->disc_data))
-#define n_hdlc2tty(n_hdlc) ((n_hdlc)->tty)
-
-static void flush_rx_queue(struct tty_struct *tty)
-{
- struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
- struct n_hdlc_buf *buf;
-
- while ((buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list)))
- n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, buf);
-}
-
-static void flush_tx_queue(struct tty_struct *tty)
-{
- struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
- struct n_hdlc_buf *buf;
- unsigned long flags;
-
- while ((buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list)))
- n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, buf);
- spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
- if (n_hdlc->tbuf) {
- n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, n_hdlc->tbuf);
- n_hdlc->tbuf = NULL;
- }
- spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
-}
-
-static struct tty_ldisc_ops n_hdlc_ldisc = {
- .owner = THIS_MODULE,
- .magic = TTY_LDISC_MAGIC,
- .name = "hdlc",
- .open = n_hdlc_tty_open,
- .close = n_hdlc_tty_close,
- .read = n_hdlc_tty_read,
- .write = n_hdlc_tty_write,
- .ioctl = n_hdlc_tty_ioctl,
- .poll = n_hdlc_tty_poll,
- .receive_buf = n_hdlc_tty_receive,
- .write_wakeup = n_hdlc_tty_wakeup,
- .flush_buffer = flush_rx_queue,
-};
-
-/**
- * n_hdlc_release - release an n_hdlc per device line discipline info structure
- * @n_hdlc - per device line discipline info structure
- */
-static void n_hdlc_release(struct n_hdlc *n_hdlc)
-{
- struct tty_struct *tty = n_hdlc2tty (n_hdlc);
- struct n_hdlc_buf *buf;
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_release() called\n",__FILE__,__LINE__);
-
- /* Ensure that the n_hdlcd process is not hanging on select()/poll() */
- wake_up_interruptible (&tty->read_wait);
- wake_up_interruptible (&tty->write_wait);
-
- if (tty->disc_data == n_hdlc)
- tty->disc_data = NULL; /* Break the tty->n_hdlc link */
-
- /* Release transmit and receive buffers */
- for(;;) {
- buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list);
- if (buf) {
- kfree(buf);
- } else
- break;
- }
- for(;;) {
- buf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list);
- if (buf) {
- kfree(buf);
- } else
- break;
- }
- for(;;) {
- buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
- if (buf) {
- kfree(buf);
- } else
- break;
- }
- for(;;) {
- buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
- if (buf) {
- kfree(buf);
- } else
- break;
- }
- kfree(n_hdlc->tbuf);
- kfree(n_hdlc);
-
-} /* end of n_hdlc_release() */
-
-/**
- * n_hdlc_tty_close - line discipline close
- * @tty - pointer to tty info structure
- *
- * Called when the line discipline is changed to something
- * else, the tty is closed, or the tty detects a hangup.
- */
-static void n_hdlc_tty_close(struct tty_struct *tty)
-{
- struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_close() called\n",__FILE__,__LINE__);
-
- if (n_hdlc != NULL) {
- if (n_hdlc->magic != HDLC_MAGIC) {
- printk (KERN_WARNING"n_hdlc: trying to close unopened tty!\n");
- return;
- }
-#if defined(TTY_NO_WRITE_SPLIT)
- clear_bit(TTY_NO_WRITE_SPLIT,&tty->flags);
-#endif
- tty->disc_data = NULL;
- if (tty == n_hdlc->backup_tty)
- n_hdlc->backup_tty = NULL;
- if (tty != n_hdlc->tty)
- return;
- if (n_hdlc->backup_tty) {
- n_hdlc->tty = n_hdlc->backup_tty;
- } else {
- n_hdlc_release (n_hdlc);
- }
- }
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_close() success\n",__FILE__,__LINE__);
-
-} /* end of n_hdlc_tty_close() */
-
-/**
- * n_hdlc_tty_open - called when line discipline changed to n_hdlc
- * @tty - pointer to tty info structure
- *
- * Returns 0 if success, otherwise error code
- */
-static int n_hdlc_tty_open (struct tty_struct *tty)
-{
- struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_open() called (device=%s)\n",
- __FILE__,__LINE__,
- tty->name);
-
- /* There should not be an existing table for this slot. */
- if (n_hdlc) {
- printk (KERN_ERR"n_hdlc_tty_open:tty already associated!\n" );
- return -EEXIST;
- }
-
- n_hdlc = n_hdlc_alloc();
- if (!n_hdlc) {
- printk (KERN_ERR "n_hdlc_alloc failed\n");
- return -ENFILE;
- }
-
- tty->disc_data = n_hdlc;
- n_hdlc->tty = tty;
- tty->receive_room = 65536;
-
-#if defined(TTY_NO_WRITE_SPLIT)
- /* change tty_io write() to not split large writes into 8K chunks */
- set_bit(TTY_NO_WRITE_SPLIT,&tty->flags);
-#endif
-
- /* flush receive data from driver */
- tty_driver_flush_buffer(tty);
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_open() success\n",__FILE__,__LINE__);
-
- return 0;
-
-} /* end of n_tty_hdlc_open() */
-
-/**
- * n_hdlc_send_frames - send frames on pending send buffer list
- * @n_hdlc - pointer to ldisc instance data
- * @tty - pointer to tty instance data
- *
- * Send frames on pending send buffer list until the driver does not accept a
- * frame (busy) this function is called after adding a frame to the send buffer
- * list and by the tty wakeup callback.
- */
-static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
-{
- register int actual;
- unsigned long flags;
- struct n_hdlc_buf *tbuf;
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_send_frames() called\n",__FILE__,__LINE__);
- check_again:
-
- spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
- if (n_hdlc->tbusy) {
- n_hdlc->woke_up = 1;
- spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
- return;
- }
- n_hdlc->tbusy = 1;
- n_hdlc->woke_up = 0;
- spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
-
- /* get current transmit buffer or get new transmit */
- /* buffer from list of pending transmit buffers */
-
- tbuf = n_hdlc->tbuf;
- if (!tbuf)
- tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
-
- while (tbuf) {
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)sending frame %p, count=%d\n",
- __FILE__,__LINE__,tbuf,tbuf->count);
-
- /* Send the next block of data to device */
- tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
- actual = tty->ops->write(tty, tbuf->buf, tbuf->count);
-
- /* rollback was possible and has been done */
- if (actual == -ERESTARTSYS) {
- n_hdlc->tbuf = tbuf;
- break;
- }
- /* if transmit error, throw frame away by */
- /* pretending it was accepted by driver */
- if (actual < 0)
- actual = tbuf->count;
-
- if (actual == tbuf->count) {
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)frame %p completed\n",
- __FILE__,__LINE__,tbuf);
-
- /* free current transmit buffer */
- n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, tbuf);
-
- /* this tx buffer is done */
- n_hdlc->tbuf = NULL;
-
- /* wait up sleeping writers */
- wake_up_interruptible(&tty->write_wait);
-
- /* get next pending transmit buffer */
- tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
- } else {
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)frame %p pending\n",
- __FILE__,__LINE__,tbuf);
-
- /* buffer not accepted by driver */
- /* set this buffer as pending buffer */
- n_hdlc->tbuf = tbuf;
- break;
- }
- }
-
- if (!tbuf)
- tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
-
- /* Clear the re-entry flag */
- spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
- n_hdlc->tbusy = 0;
- spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
-
- if (n_hdlc->woke_up)
- goto check_again;
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_send_frames() exit\n",__FILE__,__LINE__);
-
-} /* end of n_hdlc_send_frames() */
-
-/**
- * n_hdlc_tty_wakeup - Callback for transmit wakeup
- * @tty - pointer to associated tty instance data
- *
- * Called when low level device driver can accept more send data.
- */
-static void n_hdlc_tty_wakeup(struct tty_struct *tty)
-{
- struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_wakeup() called\n",__FILE__,__LINE__);
-
- if (!n_hdlc)
- return;
-
- if (tty != n_hdlc->tty) {
- tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
- return;
- }
-
- n_hdlc_send_frames (n_hdlc, tty);
-
-} /* end of n_hdlc_tty_wakeup() */
-
-/**
- * n_hdlc_tty_receive - Called by tty driver when receive data is available
- * @tty - pointer to tty instance data
- * @data - pointer to received data
- * @flags - pointer to flags for data
- * @count - count of received data in bytes
- *
- * Called by tty low level driver when receive data is available. Data is
- * interpreted as one HDLC frame.
- */
-static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data,
- char *flags, int count)
-{
- register struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
- register struct n_hdlc_buf *buf;
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_receive() called count=%d\n",
- __FILE__,__LINE__, count);
-
- /* This can happen if stuff comes in on the backup tty */
- if (!n_hdlc || tty != n_hdlc->tty)
- return;
-
- /* verify line is using HDLC discipline */
- if (n_hdlc->magic != HDLC_MAGIC) {
- printk("%s(%d) line not using HDLC discipline\n",
- __FILE__,__LINE__);
- return;
- }
-
- if ( count>maxframe ) {
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d) rx count>maxframesize, data discarded\n",
- __FILE__,__LINE__);
- return;
- }
-
- /* get a free HDLC buffer */
- buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list);
- if (!buf) {
- /* no buffers in free list, attempt to allocate another rx buffer */
- /* unless the maximum count has been reached */
- if (n_hdlc->rx_buf_list.count < MAX_RX_BUF_COUNT)
- buf = kmalloc(N_HDLC_BUF_SIZE, GFP_ATOMIC);
- }
-
- if (!buf) {
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d) no more rx buffers, data discarded\n",
- __FILE__,__LINE__);
- return;
- }
-
- /* copy received data to HDLC buffer */
- memcpy(buf->buf,data,count);
- buf->count=count;
-
- /* add HDLC buffer to list of received frames */
- n_hdlc_buf_put(&n_hdlc->rx_buf_list, buf);
-
- /* wake up any blocked reads and perform async signalling */
- wake_up_interruptible (&tty->read_wait);
- if (n_hdlc->tty->fasync != NULL)
- kill_fasync (&n_hdlc->tty->fasync, SIGIO, POLL_IN);
-
-} /* end of n_hdlc_tty_receive() */
-
-/**
- * n_hdlc_tty_read - Called to retrieve one frame of data (if available)
- * @tty - pointer to tty instance data
- * @file - pointer to open file object
- * @buf - pointer to returned data buffer
- * @nr - size of returned data buffer
- *
- * Returns the number of bytes returned or error code.
- */
-static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
- __u8 __user *buf, size_t nr)
-{
- struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
- int ret;
- struct n_hdlc_buf *rbuf;
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_read() called\n",__FILE__,__LINE__);
-
- /* Validate the pointers */
- if (!n_hdlc)
- return -EIO;
-
- /* verify user access to buffer */
- if (!access_ok(VERIFY_WRITE, buf, nr)) {
- printk(KERN_WARNING "%s(%d) n_hdlc_tty_read() can't verify user "
- "buffer\n", __FILE__, __LINE__);
- return -EFAULT;
- }
-
- tty_lock();
-
- for (;;) {
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
- tty_unlock();
- return -EIO;
- }
-
- n_hdlc = tty2n_hdlc (tty);
- if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC ||
- tty != n_hdlc->tty) {
- tty_unlock();
- return 0;
- }
-
- rbuf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
- if (rbuf)
- break;
-
- /* no data */
- if (file->f_flags & O_NONBLOCK) {
- tty_unlock();
- return -EAGAIN;
- }
-
- interruptible_sleep_on (&tty->read_wait);
- if (signal_pending(current)) {
- tty_unlock();
- return -EINTR;
- }
- }
-
- if (rbuf->count > nr)
- /* frame too large for caller's buffer (discard frame) */
- ret = -EOVERFLOW;
- else {
- /* Copy the data to the caller's buffer */
- if (copy_to_user(buf, rbuf->buf, rbuf->count))
- ret = -EFAULT;
- else
- ret = rbuf->count;
- }
-
- /* return HDLC buffer to free list unless the free list */
- /* count has exceeded the default value, in which case the */
- /* buffer is freed back to the OS to conserve memory */
- if (n_hdlc->rx_free_buf_list.count > DEFAULT_RX_BUF_COUNT)
- kfree(rbuf);
- else
- n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,rbuf);
- tty_unlock();
- return ret;
-
-} /* end of n_hdlc_tty_read() */
-
-/**
- * n_hdlc_tty_write - write a single frame of data to device
- * @tty - pointer to associated tty device instance data
- * @file - pointer to file object data
- * @data - pointer to transmit data (one frame)
- * @count - size of transmit frame in bytes
- *
- * Returns the number of bytes written (or error code).
- */
-static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
- const unsigned char *data, size_t count)
-{
- struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
- int error = 0;
- DECLARE_WAITQUEUE(wait, current);
- struct n_hdlc_buf *tbuf;
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_write() called count=%Zd\n",
- __FILE__,__LINE__,count);
-
- /* Verify pointers */
- if (!n_hdlc)
- return -EIO;
-
- if (n_hdlc->magic != HDLC_MAGIC)
- return -EIO;
-
- /* verify frame size */
- if (count > maxframe ) {
- if (debuglevel & DEBUG_LEVEL_INFO)
- printk (KERN_WARNING
- "n_hdlc_tty_write: truncating user packet "
- "from %lu to %d\n", (unsigned long) count,
- maxframe );
- count = maxframe;
- }
-
- tty_lock();
-
- add_wait_queue(&tty->write_wait, &wait);
- set_current_state(TASK_INTERRUPTIBLE);
-
- /* Allocate transmit buffer */
- /* sleep until transmit buffer available */
- while (!(tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list))) {
- if (file->f_flags & O_NONBLOCK) {
- error = -EAGAIN;
- break;
- }
- schedule();
-
- n_hdlc = tty2n_hdlc (tty);
- if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC ||
- tty != n_hdlc->tty) {
- printk("n_hdlc_tty_write: %p invalid after wait!\n", n_hdlc);
- error = -EIO;
- break;
- }
-
- if (signal_pending(current)) {
- error = -EINTR;
- break;
- }
- }
-
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&tty->write_wait, &wait);
-
- if (!error) {
- /* Retrieve the user's buffer */
- memcpy(tbuf->buf, data, count);
-
- /* Send the data */
- tbuf->count = error = count;
- n_hdlc_buf_put(&n_hdlc->tx_buf_list,tbuf);
- n_hdlc_send_frames(n_hdlc,tty);
- }
- tty_unlock();
- return error;
-
-} /* end of n_hdlc_tty_write() */
-
-/**
- * n_hdlc_tty_ioctl - process IOCTL system call for the tty device.
- * @tty - pointer to tty instance data
- * @file - pointer to open file object for device
- * @cmd - IOCTL command code
- * @arg - argument for IOCTL call (cmd dependent)
- *
- * Returns command dependent result.
- */
-static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
- int error = 0;
- int count;
- unsigned long flags;
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_ioctl() called %d\n",
- __FILE__,__LINE__,cmd);
-
- /* Verify the status of the device */
- if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC)
- return -EBADF;
-
- switch (cmd) {
- case FIONREAD:
- /* report count of read data available */
- /* in next available frame (if any) */
- spin_lock_irqsave(&n_hdlc->rx_buf_list.spinlock,flags);
- if (n_hdlc->rx_buf_list.head)
- count = n_hdlc->rx_buf_list.head->count;
- else
- count = 0;
- spin_unlock_irqrestore(&n_hdlc->rx_buf_list.spinlock,flags);
- error = put_user(count, (int __user *)arg);
- break;
-
- case TIOCOUTQ:
- /* get the pending tx byte count in the driver */
- count = tty_chars_in_buffer(tty);
- /* add size of next output frame in queue */
- spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock,flags);
- if (n_hdlc->tx_buf_list.head)
- count += n_hdlc->tx_buf_list.head->count;
- spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock,flags);
- error = put_user(count, (int __user *)arg);
- break;
-
- case TCFLSH:
- switch (arg) {
- case TCIOFLUSH:
- case TCOFLUSH:
- flush_tx_queue(tty);
- }
- /* fall through to default */
-
- default:
- error = n_tty_ioctl_helper(tty, file, cmd, arg);
- break;
- }
- return error;
-
-} /* end of n_hdlc_tty_ioctl() */
-
-/**
- * n_hdlc_tty_poll - TTY callback for poll system call
- * @tty - pointer to tty instance data
- * @filp - pointer to open file object for device
- * @poll_table - wait queue for operations
- *
- * Determine which operations (read/write) will not block and return info
- * to caller.
- * Returns a bit mask containing info on which ops will not block.
- */
-static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
- poll_table *wait)
-{
- struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
- unsigned int mask = 0;
-
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_poll() called\n",__FILE__,__LINE__);
-
- if (n_hdlc && n_hdlc->magic == HDLC_MAGIC && tty == n_hdlc->tty) {
- /* queue current process into any wait queue that */
- /* may awaken in the future (read and write) */
-
- poll_wait(filp, &tty->read_wait, wait);
- poll_wait(filp, &tty->write_wait, wait);
-
- /* set bits for operations that won't block */
- if (n_hdlc->rx_buf_list.head)
- mask |= POLLIN | POLLRDNORM; /* readable */
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
- mask |= POLLHUP;
- if (tty_hung_up_p(filp))
- mask |= POLLHUP;
- if (!tty_is_writelocked(tty) &&
- n_hdlc->tx_free_buf_list.head)
- mask |= POLLOUT | POLLWRNORM; /* writable */
- }
- return mask;
-} /* end of n_hdlc_tty_poll() */
-
-/**
- * n_hdlc_alloc - allocate an n_hdlc instance data structure
- *
- * Returns a pointer to newly created structure if success, otherwise %NULL
- */
-static struct n_hdlc *n_hdlc_alloc(void)
-{
- struct n_hdlc_buf *buf;
- int i;
- struct n_hdlc *n_hdlc = kmalloc(sizeof(*n_hdlc), GFP_KERNEL);
-
- if (!n_hdlc)
- return NULL;
-
- memset(n_hdlc, 0, sizeof(*n_hdlc));
-
- n_hdlc_buf_list_init(&n_hdlc->rx_free_buf_list);
- n_hdlc_buf_list_init(&n_hdlc->tx_free_buf_list);
- n_hdlc_buf_list_init(&n_hdlc->rx_buf_list);
- n_hdlc_buf_list_init(&n_hdlc->tx_buf_list);
-
- /* allocate free rx buffer list */
- for(i=0;i<DEFAULT_RX_BUF_COUNT;i++) {
- buf = kmalloc(N_HDLC_BUF_SIZE, GFP_KERNEL);
- if (buf)
- n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,buf);
- else if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_alloc(), kalloc() failed for rx buffer %d\n",__FILE__,__LINE__, i);
- }
-
- /* allocate free tx buffer list */
- for(i=0;i<DEFAULT_TX_BUF_COUNT;i++) {
- buf = kmalloc(N_HDLC_BUF_SIZE, GFP_KERNEL);
- if (buf)
- n_hdlc_buf_put(&n_hdlc->tx_free_buf_list,buf);
- else if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_alloc(), kalloc() failed for tx buffer %d\n",__FILE__,__LINE__, i);
- }
-
- /* Initialize the control block */
- n_hdlc->magic = HDLC_MAGIC;
- n_hdlc->flags = 0;
-
- return n_hdlc;
-
-} /* end of n_hdlc_alloc() */
-
-/**
- * n_hdlc_buf_list_init - initialize specified HDLC buffer list
- * @list - pointer to buffer list
- */
-static void n_hdlc_buf_list_init(struct n_hdlc_buf_list *list)
-{
- memset(list, 0, sizeof(*list));
- spin_lock_init(&list->spinlock);
-} /* end of n_hdlc_buf_list_init() */
-
-/**
- * n_hdlc_buf_put - add specified HDLC buffer to tail of specified list
- * @list - pointer to buffer list
- * @buf - pointer to buffer
- */
-static void n_hdlc_buf_put(struct n_hdlc_buf_list *list,
- struct n_hdlc_buf *buf)
-{
- unsigned long flags;
- spin_lock_irqsave(&list->spinlock,flags);
-
- buf->link=NULL;
- if (list->tail)
- list->tail->link = buf;
- else
- list->head = buf;
- list->tail = buf;
- (list->count)++;
-
- spin_unlock_irqrestore(&list->spinlock,flags);
-
-} /* end of n_hdlc_buf_put() */
-
-/**
- * n_hdlc_buf_get - remove and return an HDLC buffer from list
- * @list - pointer to HDLC buffer list
- *
- * Remove and return an HDLC buffer from the head of the specified HDLC buffer
- * list.
- * Returns a pointer to HDLC buffer if available, otherwise %NULL.
- */
-static struct n_hdlc_buf* n_hdlc_buf_get(struct n_hdlc_buf_list *list)
-{
- unsigned long flags;
- struct n_hdlc_buf *buf;
- spin_lock_irqsave(&list->spinlock,flags);
-
- buf = list->head;
- if (buf) {
- list->head = buf->link;
- (list->count)--;
- }
- if (!list->head)
- list->tail = NULL;
-
- spin_unlock_irqrestore(&list->spinlock,flags);
- return buf;
-
-} /* end of n_hdlc_buf_get() */
-
-static char hdlc_banner[] __initdata =
- KERN_INFO "HDLC line discipline maxframe=%u\n";
-static char hdlc_register_ok[] __initdata =
- KERN_INFO "N_HDLC line discipline registered.\n";
-static char hdlc_register_fail[] __initdata =
- KERN_ERR "error registering line discipline: %d\n";
-static char hdlc_init_fail[] __initdata =
- KERN_INFO "N_HDLC: init failure %d\n";
-
-static int __init n_hdlc_init(void)
-{
- int status;
-
- /* range check maxframe arg */
- if (maxframe < 4096)
- maxframe = 4096;
- else if (maxframe > 65535)
- maxframe = 65535;
-
- printk(hdlc_banner, maxframe);
-
- status = tty_register_ldisc(N_HDLC, &n_hdlc_ldisc);
- if (!status)
- printk(hdlc_register_ok);
- else
- printk(hdlc_register_fail, status);
-
- if (status)
- printk(hdlc_init_fail, status);
- return status;
-
-} /* end of init_module() */
-
-static char hdlc_unregister_ok[] __exitdata =
- KERN_INFO "N_HDLC: line discipline unregistered\n";
-static char hdlc_unregister_fail[] __exitdata =
- KERN_ERR "N_HDLC: can't unregister line discipline (err = %d)\n";
-
-static void __exit n_hdlc_exit(void)
-{
- /* Release tty registration of line discipline */
- int status = tty_unregister_ldisc(N_HDLC);
-
- if (status)
- printk(hdlc_unregister_fail, status);
- else
- printk(hdlc_unregister_ok);
-}
-
-module_init(n_hdlc_init);
-module_exit(n_hdlc_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Paul Fulghum paulkf@microgate.com");
-module_param(debuglevel, int, 0);
-module_param(maxframe, int, 0);
-MODULE_ALIAS_LDISC(N_HDLC);
+++ /dev/null
-/* r3964 linediscipline for linux
- *
- * -----------------------------------------------------------
- * Copyright by
- * Philips Automation Projects
- * Kassel (Germany)
- * -----------------------------------------------------------
- * This software may be used and distributed according to the terms of
- * the GNU General Public License, incorporated herein by reference.
- *
- * Author:
- * L. Haag
- *
- * $Log: n_r3964.c,v $
- * Revision 1.10 2001/03/18 13:02:24 dwmw2
- * Fix timer usage, use spinlocks properly.
- *
- * Revision 1.9 2001/03/18 12:52:14 dwmw2
- * Merge changes in 2.4.2
- *
- * Revision 1.8 2000/03/23 14:14:54 dwmw2
- * Fix race in sleeping in r3964_read()
- *
- * Revision 1.7 1999/28/08 11:41:50 dwmw2
- * Port to 2.3 kernel
- *
- * Revision 1.6 1998/09/30 00:40:40 dwmw2
- * Fixed compilation on 2.0.x kernels
- * Updated to newly registered tty-ldisc number 9
- *
- * Revision 1.5 1998/09/04 21:57:36 dwmw2
- * Signal handling bug fixes, port to 2.1.x.
- *
- * Revision 1.4 1998/04/02 20:26:59 lhaag
- * select, blocking, ...
- *
- * Revision 1.3 1998/02/12 18:58:43 root
- * fixed some memory leaks
- * calculation of checksum characters
- *
- * Revision 1.2 1998/02/07 13:03:34 root
- * ioctl read_telegram
- *
- * Revision 1.1 1998/02/06 19:21:03 root
- * Initial revision
- *
- *
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/types.h>
-#include <linux/fcntl.h>
-#include <linux/interrupt.h>
-#include <linux/ptrace.h>
-#include <linux/ioport.h>
-#include <linux/in.h>
-#include <linux/slab.h>
-#include <linux/smp_lock.h>
-#include <linux/tty.h>
-#include <linux/errno.h>
-#include <linux/string.h> /* used in new tty drivers */
-#include <linux/signal.h> /* used in new tty drivers */
-#include <linux/ioctl.h>
-#include <linux/n_r3964.h>
-#include <linux/poll.h>
-#include <linux/init.h>
-#include <asm/uaccess.h>
-
-/*#define DEBUG_QUEUE*/
-
-/* Log successful handshake and protocol operations */
-/*#define DEBUG_PROTO_S*/
-
-/* Log handshake and protocol errors: */
-/*#define DEBUG_PROTO_E*/
-
-/* Log Linediscipline operations (open, close, read, write...): */
-/*#define DEBUG_LDISC*/
-
-/* Log module and memory operations (init, cleanup; kmalloc, kfree): */
-/*#define DEBUG_MODUL*/
-
-/* Macro helpers for debug output: */
-#define TRACE(format, args...) printk("r3964: " format "\n" , ## args)
-
-#ifdef DEBUG_MODUL
-#define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_M(fmt, arg...) do {} while (0)
-#endif
-#ifdef DEBUG_PROTO_S
-#define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_PS(fmt, arg...) do {} while (0)
-#endif
-#ifdef DEBUG_PROTO_E
-#define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_PE(fmt, arg...) do {} while (0)
-#endif
-#ifdef DEBUG_LDISC
-#define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_L(fmt, arg...) do {} while (0)
-#endif
-#ifdef DEBUG_QUEUE
-#define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args)
-#else
-#define TRACE_Q(fmt, arg...) do {} while (0)
-#endif
-static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
-static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
-static void put_char(struct r3964_info *pInfo, unsigned char ch);
-static void trigger_transmit(struct r3964_info *pInfo);
-static void retry_transmit(struct r3964_info *pInfo);
-static void transmit_block(struct r3964_info *pInfo);
-static void receive_char(struct r3964_info *pInfo, const unsigned char c);
-static void receive_error(struct r3964_info *pInfo, const char flag);
-static void on_timeout(unsigned long priv);
-static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg);
-static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
- unsigned char __user * buf);
-static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
- int error_code, struct r3964_block_header *pBlock);
-static struct r3964_message *remove_msg(struct r3964_info *pInfo,
- struct r3964_client_info *pClient);
-static void remove_client_block(struct r3964_info *pInfo,
- struct r3964_client_info *pClient);
-
-static int r3964_open(struct tty_struct *tty);
-static void r3964_close(struct tty_struct *tty);
-static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
- unsigned char __user * buf, size_t nr);
-static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
- const unsigned char *buf, size_t nr);
-static int r3964_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg);
-static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old);
-static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
- struct poll_table_struct *wait);
-static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
- char *fp, int count);
-
-static struct tty_ldisc_ops tty_ldisc_N_R3964 = {
- .owner = THIS_MODULE,
- .magic = TTY_LDISC_MAGIC,
- .name = "R3964",
- .open = r3964_open,
- .close = r3964_close,
- .read = r3964_read,
- .write = r3964_write,
- .ioctl = r3964_ioctl,
- .set_termios = r3964_set_termios,
- .poll = r3964_poll,
- .receive_buf = r3964_receive_buf,
-};
-
-static void dump_block(const unsigned char *block, unsigned int length)
-{
- unsigned int i, j;
- char linebuf[16 * 3 + 1];
-
- for (i = 0; i < length; i += 16) {
- for (j = 0; (j < 16) && (j + i < length); j++) {
- sprintf(linebuf + 3 * j, "%02x ", block[i + j]);
- }
- linebuf[3 * j] = '\0';
- TRACE_PS("%s", linebuf);
- }
-}
-
-/*************************************************************
- * Driver initialisation
- *************************************************************/
-
-/*************************************************************
- * Module support routines
- *************************************************************/
-
-static void __exit r3964_exit(void)
-{
- int status;
-
- TRACE_M("cleanup_module()");
-
- status = tty_unregister_ldisc(N_R3964);
-
- if (status != 0) {
- printk(KERN_ERR "r3964: error unregistering linediscipline: "
- "%d\n", status);
- } else {
- TRACE_L("linediscipline successfully unregistered");
- }
-}
-
-static int __init r3964_init(void)
-{
- int status;
-
- printk("r3964: Philips r3964 Driver $Revision: 1.10 $\n");
-
- /*
- * Register the tty line discipline
- */
-
- status = tty_register_ldisc(N_R3964, &tty_ldisc_N_R3964);
- if (status == 0) {
- TRACE_L("line discipline %d registered", N_R3964);
- TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags,
- tty_ldisc_N_R3964.num);
- TRACE_L("open=%p", tty_ldisc_N_R3964.open);
- TRACE_L("tty_ldisc_N_R3964 = %p", &tty_ldisc_N_R3964);
- } else {
- printk(KERN_ERR "r3964: error registering line discipline: "
- "%d\n", status);
- }
- return status;
-}
-
-module_init(r3964_init);
-module_exit(r3964_exit);
-
-/*************************************************************
- * Protocol implementation routines
- *************************************************************/
-
-static void add_tx_queue(struct r3964_info *pInfo,
- struct r3964_block_header *pHeader)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&pInfo->lock, flags);
-
- pHeader->next = NULL;
-
- if (pInfo->tx_last == NULL) {
- pInfo->tx_first = pInfo->tx_last = pHeader;
- } else {
- pInfo->tx_last->next = pHeader;
- pInfo->tx_last = pHeader;
- }
-
- spin_unlock_irqrestore(&pInfo->lock, flags);
-
- TRACE_Q("add_tx_queue %p, length %d, tx_first = %p",
- pHeader, pHeader->length, pInfo->tx_first);
-}
-
-static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
-{
- struct r3964_block_header *pHeader;
- unsigned long flags;
-#ifdef DEBUG_QUEUE
- struct r3964_block_header *pDump;
-#endif
-
- pHeader = pInfo->tx_first;
-
- if (pHeader == NULL)
- return;
-
-#ifdef DEBUG_QUEUE
- printk("r3964: remove_from_tx_queue: %p, length %u - ",
- pHeader, pHeader->length);
- for (pDump = pHeader; pDump; pDump = pDump->next)
- printk("%p ", pDump);
- printk("\n");
-#endif
-
- if (pHeader->owner) {
- if (error_code) {
- add_msg(pHeader->owner, R3964_MSG_ACK, 0,
- error_code, NULL);
- } else {
- add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
- error_code, NULL);
- }
- wake_up_interruptible(&pInfo->read_wait);
- }
-
- spin_lock_irqsave(&pInfo->lock, flags);
-
- pInfo->tx_first = pHeader->next;
- if (pInfo->tx_first == NULL) {
- pInfo->tx_last = NULL;
- }
-
- spin_unlock_irqrestore(&pInfo->lock, flags);
-
- kfree(pHeader);
- TRACE_M("remove_from_tx_queue - kfree %p", pHeader);
-
- TRACE_Q("remove_from_tx_queue: tx_first = %p, tx_last = %p",
- pInfo->tx_first, pInfo->tx_last);
-}
-
-static void add_rx_queue(struct r3964_info *pInfo,
- struct r3964_block_header *pHeader)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&pInfo->lock, flags);
-
- pHeader->next = NULL;
-
- if (pInfo->rx_last == NULL) {
- pInfo->rx_first = pInfo->rx_last = pHeader;
- } else {
- pInfo->rx_last->next = pHeader;
- pInfo->rx_last = pHeader;
- }
- pInfo->blocks_in_rx_queue++;
-
- spin_unlock_irqrestore(&pInfo->lock, flags);
-
- TRACE_Q("add_rx_queue: %p, length = %d, rx_first = %p, count = %d",
- pHeader, pHeader->length,
- pInfo->rx_first, pInfo->blocks_in_rx_queue);
-}
-
-static void remove_from_rx_queue(struct r3964_info *pInfo,
- struct r3964_block_header *pHeader)
-{
- unsigned long flags;
- struct r3964_block_header *pFind;
-
- if (pHeader == NULL)
- return;
-
- TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
- pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
- TRACE_Q("remove_from_rx_queue: %p, length %u",
- pHeader, pHeader->length);
-
- spin_lock_irqsave(&pInfo->lock, flags);
-
- if (pInfo->rx_first == pHeader) {
- /* Remove the first block in the linked list: */
- pInfo->rx_first = pHeader->next;
-
- if (pInfo->rx_first == NULL) {
- pInfo->rx_last = NULL;
- }
- pInfo->blocks_in_rx_queue--;
- } else {
- /* Find block to remove: */
- for (pFind = pInfo->rx_first; pFind; pFind = pFind->next) {
- if (pFind->next == pHeader) {
- /* Got it. */
- pFind->next = pHeader->next;
- pInfo->blocks_in_rx_queue--;
- if (pFind->next == NULL) {
- /* Oh, removed the last one! */
- pInfo->rx_last = pFind;
- }
- break;
- }
- }
- }
-
- spin_unlock_irqrestore(&pInfo->lock, flags);
-
- kfree(pHeader);
- TRACE_M("remove_from_rx_queue - kfree %p", pHeader);
-
- TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
- pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
-}
-
-static void put_char(struct r3964_info *pInfo, unsigned char ch)
-{
- struct tty_struct *tty = pInfo->tty;
- /* FIXME: put_char should not be called from an IRQ */
- tty_put_char(tty, ch);
- pInfo->bcc ^= ch;
-}
-
-static void flush(struct r3964_info *pInfo)
-{
- struct tty_struct *tty = pInfo->tty;
-
- if (tty == NULL || tty->ops->flush_chars == NULL)
- return;
- tty->ops->flush_chars(tty);
-}
-
-static void trigger_transmit(struct r3964_info *pInfo)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&pInfo->lock, flags);
-
- if ((pInfo->state == R3964_IDLE) && (pInfo->tx_first != NULL)) {
- pInfo->state = R3964_TX_REQUEST;
- pInfo->nRetry = 0;
- pInfo->flags &= ~R3964_ERROR;
- mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
-
- spin_unlock_irqrestore(&pInfo->lock, flags);
-
- TRACE_PS("trigger_transmit - sent STX");
-
- put_char(pInfo, STX);
- flush(pInfo);
-
- pInfo->bcc = 0;
- } else {
- spin_unlock_irqrestore(&pInfo->lock, flags);
- }
-}
-
-static void retry_transmit(struct r3964_info *pInfo)
-{
- if (pInfo->nRetry < R3964_MAX_RETRIES) {
- TRACE_PE("transmission failed. Retry #%d", pInfo->nRetry);
- pInfo->bcc = 0;
- put_char(pInfo, STX);
- flush(pInfo);
- pInfo->state = R3964_TX_REQUEST;
- pInfo->nRetry++;
- mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
- } else {
- TRACE_PE("transmission failed after %d retries",
- R3964_MAX_RETRIES);
-
- remove_from_tx_queue(pInfo, R3964_TX_FAIL);
-
- put_char(pInfo, NAK);
- flush(pInfo);
- pInfo->state = R3964_IDLE;
-
- trigger_transmit(pInfo);
- }
-}
-
-static void transmit_block(struct r3964_info *pInfo)
-{
- struct tty_struct *tty = pInfo->tty;
- struct r3964_block_header *pBlock = pInfo->tx_first;
- int room = 0;
-
- if (tty == NULL || pBlock == NULL) {
- return;
- }
-
- room = tty_write_room(tty);
-
- TRACE_PS("transmit_block %p, room %d, length %d",
- pBlock, room, pBlock->length);
-
- while (pInfo->tx_position < pBlock->length) {
- if (room < 2)
- break;
-
- if (pBlock->data[pInfo->tx_position] == DLE) {
- /* send additional DLE char: */
- put_char(pInfo, DLE);
- }
- put_char(pInfo, pBlock->data[pInfo->tx_position++]);
-
- room--;
- }
-
- if ((pInfo->tx_position == pBlock->length) && (room >= 3)) {
- put_char(pInfo, DLE);
- put_char(pInfo, ETX);
- if (pInfo->flags & R3964_BCC) {
- put_char(pInfo, pInfo->bcc);
- }
- pInfo->state = R3964_WAIT_FOR_TX_ACK;
- mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
- }
- flush(pInfo);
-}
-
-static void on_receive_block(struct r3964_info *pInfo)
-{
- unsigned int length;
- struct r3964_client_info *pClient;
- struct r3964_block_header *pBlock;
-
- length = pInfo->rx_position;
-
- /* compare byte checksum characters: */
- if (pInfo->flags & R3964_BCC) {
- if (pInfo->bcc != pInfo->last_rx) {
- TRACE_PE("checksum error - got %x but expected %x",
- pInfo->last_rx, pInfo->bcc);
- pInfo->flags |= R3964_CHECKSUM;
- }
- }
-
- /* check for errors (parity, overrun,...): */
- if (pInfo->flags & R3964_ERROR) {
- TRACE_PE("on_receive_block - transmission failed error %x",
- pInfo->flags & R3964_ERROR);
-
- put_char(pInfo, NAK);
- flush(pInfo);
- if (pInfo->nRetry < R3964_MAX_RETRIES) {
- pInfo->state = R3964_WAIT_FOR_RX_REPEAT;
- pInfo->nRetry++;
- mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
- } else {
- TRACE_PE("on_receive_block - failed after max retries");
- pInfo->state = R3964_IDLE;
- }
- return;
- }
-
- /* received block; submit DLE: */
- put_char(pInfo, DLE);
- flush(pInfo);
- del_timer_sync(&pInfo->tmr);
- TRACE_PS(" rx success: got %d chars", length);
-
- /* prepare struct r3964_block_header: */
- pBlock = kmalloc(length + sizeof(struct r3964_block_header),
- GFP_KERNEL);
- TRACE_M("on_receive_block - kmalloc %p", pBlock);
-
- if (pBlock == NULL)
- return;
-
- pBlock->length = length;
- pBlock->data = ((unsigned char *)pBlock) +
- sizeof(struct r3964_block_header);
- pBlock->locks = 0;
- pBlock->next = NULL;
- pBlock->owner = NULL;
-
- memcpy(pBlock->data, pInfo->rx_buf, length);
-
- /* queue block into rx_queue: */
- add_rx_queue(pInfo, pBlock);
-
- /* notify attached client processes: */
- for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
- if (pClient->sig_flags & R3964_SIG_DATA) {
- add_msg(pClient, R3964_MSG_DATA, length, R3964_OK,
- pBlock);
- }
- }
- wake_up_interruptible(&pInfo->read_wait);
-
- pInfo->state = R3964_IDLE;
-
- trigger_transmit(pInfo);
-}
-
-static void receive_char(struct r3964_info *pInfo, const unsigned char c)
-{
- switch (pInfo->state) {
- case R3964_TX_REQUEST:
- if (c == DLE) {
- TRACE_PS("TX_REQUEST - got DLE");
-
- pInfo->state = R3964_TRANSMITTING;
- pInfo->tx_position = 0;
-
- transmit_block(pInfo);
- } else if (c == STX) {
- if (pInfo->nRetry == 0) {
- TRACE_PE("TX_REQUEST - init conflict");
- if (pInfo->priority == R3964_SLAVE) {
- goto start_receiving;
- }
- } else {
- TRACE_PE("TX_REQUEST - secondary init "
- "conflict!? Switching to SLAVE mode "
- "for next rx.");
- goto start_receiving;
- }
- } else {
- TRACE_PE("TX_REQUEST - char != DLE: %x", c);
- retry_transmit(pInfo);
- }
- break;
- case R3964_TRANSMITTING:
- if (c == NAK) {
- TRACE_PE("TRANSMITTING - got NAK");
- retry_transmit(pInfo);
- } else {
- TRACE_PE("TRANSMITTING - got invalid char");
-
- pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
- mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
- }
- break;
- case R3964_WAIT_FOR_TX_ACK:
- if (c == DLE) {
- TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
- remove_from_tx_queue(pInfo, R3964_OK);
-
- pInfo->state = R3964_IDLE;
- trigger_transmit(pInfo);
- } else {
- retry_transmit(pInfo);
- }
- break;
- case R3964_WAIT_FOR_RX_REPEAT:
- /* FALLTHROUGH */
- case R3964_IDLE:
- if (c == STX) {
- /* Prevent rx_queue from overflow: */
- if (pInfo->blocks_in_rx_queue >=
- R3964_MAX_BLOCKS_IN_RX_QUEUE) {
- TRACE_PE("IDLE - got STX but no space in "
- "rx_queue!");
- pInfo->state = R3964_WAIT_FOR_RX_BUF;
- mod_timer(&pInfo->tmr,
- jiffies + R3964_TO_NO_BUF);
- break;
- }
-start_receiving:
- /* Ok, start receiving: */
- TRACE_PS("IDLE - got STX");
- pInfo->rx_position = 0;
- pInfo->last_rx = 0;
- pInfo->flags &= ~R3964_ERROR;
- pInfo->state = R3964_RECEIVING;
- mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
- pInfo->nRetry = 0;
- put_char(pInfo, DLE);
- flush(pInfo);
- pInfo->bcc = 0;
- }
- break;
- case R3964_RECEIVING:
- if (pInfo->rx_position < RX_BUF_SIZE) {
- pInfo->bcc ^= c;
-
- if (c == DLE) {
- if (pInfo->last_rx == DLE) {
- pInfo->last_rx = 0;
- goto char_to_buf;
- }
- pInfo->last_rx = DLE;
- break;
- } else if ((c == ETX) && (pInfo->last_rx == DLE)) {
- if (pInfo->flags & R3964_BCC) {
- pInfo->state = R3964_WAIT_FOR_BCC;
- mod_timer(&pInfo->tmr,
- jiffies + R3964_TO_ZVZ);
- } else {
- on_receive_block(pInfo);
- }
- } else {
- pInfo->last_rx = c;
-char_to_buf:
- pInfo->rx_buf[pInfo->rx_position++] = c;
- mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
- }
- }
- /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
- break;
- case R3964_WAIT_FOR_BCC:
- pInfo->last_rx = c;
- on_receive_block(pInfo);
- break;
- }
-}
-
-static void receive_error(struct r3964_info *pInfo, const char flag)
-{
- switch (flag) {
- case TTY_NORMAL:
- break;
- case TTY_BREAK:
- TRACE_PE("received break");
- pInfo->flags |= R3964_BREAK;
- break;
- case TTY_PARITY:
- TRACE_PE("parity error");
- pInfo->flags |= R3964_PARITY;
- break;
- case TTY_FRAME:
- TRACE_PE("frame error");
- pInfo->flags |= R3964_FRAME;
- break;
- case TTY_OVERRUN:
- TRACE_PE("frame overrun");
- pInfo->flags |= R3964_OVERRUN;
- break;
- default:
- TRACE_PE("receive_error - unknown flag %d", flag);
- pInfo->flags |= R3964_UNKNOWN;
- break;
- }
-}
-
-static void on_timeout(unsigned long priv)
-{
- struct r3964_info *pInfo = (void *)priv;
-
- switch (pInfo->state) {
- case R3964_TX_REQUEST:
- TRACE_PE("TX_REQUEST - timeout");
- retry_transmit(pInfo);
- break;
- case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
- put_char(pInfo, NAK);
- flush(pInfo);
- retry_transmit(pInfo);
- break;
- case R3964_WAIT_FOR_TX_ACK:
- TRACE_PE("WAIT_FOR_TX_ACK - timeout");
- retry_transmit(pInfo);
- break;
- case R3964_WAIT_FOR_RX_BUF:
- TRACE_PE("WAIT_FOR_RX_BUF - timeout");
- put_char(pInfo, NAK);
- flush(pInfo);
- pInfo->state = R3964_IDLE;
- break;
- case R3964_RECEIVING:
- TRACE_PE("RECEIVING - timeout after %d chars",
- pInfo->rx_position);
- put_char(pInfo, NAK);
- flush(pInfo);
- pInfo->state = R3964_IDLE;
- break;
- case R3964_WAIT_FOR_RX_REPEAT:
- TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
- pInfo->state = R3964_IDLE;
- break;
- case R3964_WAIT_FOR_BCC:
- TRACE_PE("WAIT_FOR_BCC - timeout");
- put_char(pInfo, NAK);
- flush(pInfo);
- pInfo->state = R3964_IDLE;
- break;
- }
-}
-
-static struct r3964_client_info *findClient(struct r3964_info *pInfo,
- struct pid *pid)
-{
- struct r3964_client_info *pClient;
-
- for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
- if (pClient->pid == pid) {
- return pClient;
- }
- }
- return NULL;
-}
-
-static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg)
-{
- struct r3964_client_info *pClient;
- struct r3964_client_info **ppClient;
- struct r3964_message *pMsg;
-
- if ((arg & R3964_SIG_ALL) == 0) {
- /* Remove client from client list */
- for (ppClient = &pInfo->firstClient; *ppClient;
- ppClient = &(*ppClient)->next) {
- pClient = *ppClient;
-
- if (pClient->pid == pid) {
- TRACE_PS("removing client %d from client list",
- pid_nr(pid));
- *ppClient = pClient->next;
- while (pClient->msg_count) {
- pMsg = remove_msg(pInfo, pClient);
- if (pMsg) {
- kfree(pMsg);
- TRACE_M("enable_signals - msg "
- "kfree %p", pMsg);
- }
- }
- put_pid(pClient->pid);
- kfree(pClient);
- TRACE_M("enable_signals - kfree %p", pClient);
- return 0;
- }
- }
- return -EINVAL;
- } else {
- pClient = findClient(pInfo, pid);
- if (pClient) {
- /* update signal options */
- pClient->sig_flags = arg;
- } else {
- /* add client to client list */
- pClient = kmalloc(sizeof(struct r3964_client_info),
- GFP_KERNEL);
- TRACE_M("enable_signals - kmalloc %p", pClient);
- if (pClient == NULL)
- return -ENOMEM;
-
- TRACE_PS("add client %d to client list", pid_nr(pid));
- spin_lock_init(&pClient->lock);
- pClient->sig_flags = arg;
- pClient->pid = get_pid(pid);
- pClient->next = pInfo->firstClient;
- pClient->first_msg = NULL;
- pClient->last_msg = NULL;
- pClient->next_block_to_read = NULL;
- pClient->msg_count = 0;
- pInfo->firstClient = pClient;
- }
- }
-
- return 0;
-}
-
-static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
- unsigned char __user * buf)
-{
- struct r3964_client_info *pClient;
- struct r3964_block_header *block;
-
- if (!buf) {
- return -EINVAL;
- }
-
- pClient = findClient(pInfo, pid);
- if (pClient == NULL) {
- return -EINVAL;
- }
-
- block = pClient->next_block_to_read;
- if (!block) {
- return 0;
- } else {
- if (copy_to_user(buf, block->data, block->length))
- return -EFAULT;
-
- remove_client_block(pInfo, pClient);
- return block->length;
- }
-
- return -EINVAL;
-}
-
-static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
- int error_code, struct r3964_block_header *pBlock)
-{
- struct r3964_message *pMsg;
- unsigned long flags;
-
- if (pClient->msg_count < R3964_MAX_MSG_COUNT - 1) {
-queue_the_message:
-
- pMsg = kmalloc(sizeof(struct r3964_message),
- error_code ? GFP_ATOMIC : GFP_KERNEL);
- TRACE_M("add_msg - kmalloc %p", pMsg);
- if (pMsg == NULL) {
- return;
- }
-
- spin_lock_irqsave(&pClient->lock, flags);
-
- pMsg->msg_id = msg_id;
- pMsg->arg = arg;
- pMsg->error_code = error_code;
- pMsg->block = pBlock;
- pMsg->next = NULL;
-
- if (pClient->last_msg == NULL) {
- pClient->first_msg = pClient->last_msg = pMsg;
- } else {
- pClient->last_msg->next = pMsg;
- pClient->last_msg = pMsg;
- }
-
- pClient->msg_count++;
-
- if (pBlock != NULL) {
- pBlock->locks++;
- }
- spin_unlock_irqrestore(&pClient->lock, flags);
- } else {
- if ((pClient->last_msg->msg_id == R3964_MSG_ACK)
- && (pClient->last_msg->error_code == R3964_OVERFLOW)) {
- pClient->last_msg->arg++;
- TRACE_PE("add_msg - inc prev OVERFLOW-msg");
- } else {
- msg_id = R3964_MSG_ACK;
- arg = 0;
- error_code = R3964_OVERFLOW;
- pBlock = NULL;
- TRACE_PE("add_msg - queue OVERFLOW-msg");
- goto queue_the_message;
- }
- }
- /* Send SIGIO signal to client process: */
- if (pClient->sig_flags & R3964_USE_SIGIO) {
- kill_pid(pClient->pid, SIGIO, 1);
- }
-}
-
-static struct r3964_message *remove_msg(struct r3964_info *pInfo,
- struct r3964_client_info *pClient)
-{
- struct r3964_message *pMsg = NULL;
- unsigned long flags;
-
- if (pClient->first_msg) {
- spin_lock_irqsave(&pClient->lock, flags);
-
- pMsg = pClient->first_msg;
- pClient->first_msg = pMsg->next;
- if (pClient->first_msg == NULL) {
- pClient->last_msg = NULL;
- }
-
- pClient->msg_count--;
- if (pMsg->block) {
- remove_client_block(pInfo, pClient);
- pClient->next_block_to_read = pMsg->block;
- }
- spin_unlock_irqrestore(&pClient->lock, flags);
- }
- return pMsg;
-}
-
-static void remove_client_block(struct r3964_info *pInfo,
- struct r3964_client_info *pClient)
-{
- struct r3964_block_header *block;
-
- TRACE_PS("remove_client_block PID %d", pid_nr(pClient->pid));
-
- block = pClient->next_block_to_read;
- if (block) {
- block->locks--;
- if (block->locks == 0) {
- remove_from_rx_queue(pInfo, block);
- }
- }
- pClient->next_block_to_read = NULL;
-}
-
-/*************************************************************
- * Line discipline routines
- *************************************************************/
-
-static int r3964_open(struct tty_struct *tty)
-{
- struct r3964_info *pInfo;
-
- TRACE_L("open");
- TRACE_L("tty=%p, PID=%d, disc_data=%p",
- tty, current->pid, tty->disc_data);
-
- pInfo = kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
- TRACE_M("r3964_open - info kmalloc %p", pInfo);
-
- if (!pInfo) {
- printk(KERN_ERR "r3964: failed to alloc info structure\n");
- return -ENOMEM;
- }
-
- pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
- TRACE_M("r3964_open - rx_buf kmalloc %p", pInfo->rx_buf);
-
- if (!pInfo->rx_buf) {
- printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
- kfree(pInfo);
- TRACE_M("r3964_open - info kfree %p", pInfo);
- return -ENOMEM;
- }
-
- pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
- TRACE_M("r3964_open - tx_buf kmalloc %p", pInfo->tx_buf);
-
- if (!pInfo->tx_buf) {
- printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
- kfree(pInfo->rx_buf);
- TRACE_M("r3964_open - rx_buf kfree %p", pInfo->rx_buf);
- kfree(pInfo);
- TRACE_M("r3964_open - info kfree %p", pInfo);
- return -ENOMEM;
- }
-
- spin_lock_init(&pInfo->lock);
- pInfo->tty = tty;
- init_waitqueue_head(&pInfo->read_wait);
- pInfo->priority = R3964_MASTER;
- pInfo->rx_first = pInfo->rx_last = NULL;
- pInfo->tx_first = pInfo->tx_last = NULL;
- pInfo->rx_position = 0;
- pInfo->tx_position = 0;
- pInfo->last_rx = 0;
- pInfo->blocks_in_rx_queue = 0;
- pInfo->firstClient = NULL;
- pInfo->state = R3964_IDLE;
- pInfo->flags = R3964_DEBUG;
- pInfo->nRetry = 0;
-
- tty->disc_data = pInfo;
- tty->receive_room = 65536;
-
- setup_timer(&pInfo->tmr, on_timeout, (unsigned long)pInfo);
-
- return 0;
-}
-
-static void r3964_close(struct tty_struct *tty)
-{
- struct r3964_info *pInfo = tty->disc_data;
- struct r3964_client_info *pClient, *pNext;
- struct r3964_message *pMsg;
- struct r3964_block_header *pHeader, *pNextHeader;
- unsigned long flags;
-
- TRACE_L("close");
-
- /*
- * Make sure that our task queue isn't activated. If it
- * is, take it out of the linked list.
- */
- del_timer_sync(&pInfo->tmr);
-
- /* Remove client-structs and message queues: */
- pClient = pInfo->firstClient;
- while (pClient) {
- pNext = pClient->next;
- while (pClient->msg_count) {
- pMsg = remove_msg(pInfo, pClient);
- if (pMsg) {
- kfree(pMsg);
- TRACE_M("r3964_close - msg kfree %p", pMsg);
- }
- }
- put_pid(pClient->pid);
- kfree(pClient);
- TRACE_M("r3964_close - client kfree %p", pClient);
- pClient = pNext;
- }
- /* Remove jobs from tx_queue: */
- spin_lock_irqsave(&pInfo->lock, flags);
- pHeader = pInfo->tx_first;
- pInfo->tx_first = pInfo->tx_last = NULL;
- spin_unlock_irqrestore(&pInfo->lock, flags);
-
- while (pHeader) {
- pNextHeader = pHeader->next;
- kfree(pHeader);
- pHeader = pNextHeader;
- }
-
- /* Free buffers: */
- wake_up_interruptible(&pInfo->read_wait);
- kfree(pInfo->rx_buf);
- TRACE_M("r3964_close - rx_buf kfree %p", pInfo->rx_buf);
- kfree(pInfo->tx_buf);
- TRACE_M("r3964_close - tx_buf kfree %p", pInfo->tx_buf);
- kfree(pInfo);
- TRACE_M("r3964_close - info kfree %p", pInfo);
-}
-
-static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
- unsigned char __user * buf, size_t nr)
-{
- struct r3964_info *pInfo = tty->disc_data;
- struct r3964_client_info *pClient;
- struct r3964_message *pMsg;
- struct r3964_client_message theMsg;
- int ret;
-
- TRACE_L("read()");
-
- tty_lock();
-
- pClient = findClient(pInfo, task_pid(current));
- if (pClient) {
- pMsg = remove_msg(pInfo, pClient);
- if (pMsg == NULL) {
- /* no messages available. */
- if (file->f_flags & O_NONBLOCK) {
- ret = -EAGAIN;
- goto unlock;
- }
- /* block until there is a message: */
- wait_event_interruptible_tty(pInfo->read_wait,
- (pMsg = remove_msg(pInfo, pClient)));
- }
-
- /* If we still haven't got a message, we must have been signalled */
-
- if (!pMsg) {
- ret = -EINTR;
- goto unlock;
- }
-
- /* deliver msg to client process: */
- theMsg.msg_id = pMsg->msg_id;
- theMsg.arg = pMsg->arg;
- theMsg.error_code = pMsg->error_code;
- ret = sizeof(struct r3964_client_message);
-
- kfree(pMsg);
- TRACE_M("r3964_read - msg kfree %p", pMsg);
-
- if (copy_to_user(buf, &theMsg, ret)) {
- ret = -EFAULT;
- goto unlock;
- }
-
- TRACE_PS("read - return %d", ret);
- goto unlock;
- }
- ret = -EPERM;
-unlock:
- tty_unlock();
- return ret;
-}
-
-static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
- const unsigned char *data, size_t count)
-{
- struct r3964_info *pInfo = tty->disc_data;
- struct r3964_block_header *pHeader;
- struct r3964_client_info *pClient;
- unsigned char *new_data;
-
- TRACE_L("write request, %d characters", count);
-/*
- * Verify the pointers
- */
-
- if (!pInfo)
- return -EIO;
-
-/*
- * Ensure that the caller does not wish to send too much.
- */
- if (count > R3964_MTU) {
- if (pInfo->flags & R3964_DEBUG) {
- TRACE_L(KERN_WARNING "r3964_write: truncating user "
- "packet from %u to mtu %d", count, R3964_MTU);
- }
- count = R3964_MTU;
- }
-/*
- * Allocate a buffer for the data and copy it from the buffer with header prepended
- */
- new_data = kmalloc(count + sizeof(struct r3964_block_header),
- GFP_KERNEL);
- TRACE_M("r3964_write - kmalloc %p", new_data);
- if (new_data == NULL) {
- if (pInfo->flags & R3964_DEBUG) {
- printk(KERN_ERR "r3964_write: no memory\n");
- }
- return -ENOSPC;
- }
-
- pHeader = (struct r3964_block_header *)new_data;
- pHeader->data = new_data + sizeof(struct r3964_block_header);
- pHeader->length = count;
- pHeader->locks = 0;
- pHeader->owner = NULL;
-
- tty_lock();
-
- pClient = findClient(pInfo, task_pid(current));
- if (pClient) {
- pHeader->owner = pClient;
- }
-
- memcpy(pHeader->data, data, count); /* We already verified this */
-
- if (pInfo->flags & R3964_DEBUG) {
- dump_block(pHeader->data, count);
- }
-
-/*
- * Add buffer to transmit-queue:
- */
- add_tx_queue(pInfo, pHeader);
- trigger_transmit(pInfo);
-
- tty_unlock();
-
- return 0;
-}
-
-static int r3964_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- struct r3964_info *pInfo = tty->disc_data;
- if (pInfo == NULL)
- return -EINVAL;
- switch (cmd) {
- case R3964_ENABLE_SIGNALS:
- return enable_signals(pInfo, task_pid(current), arg);
- case R3964_SETPRIORITY:
- if (arg < R3964_MASTER || arg > R3964_SLAVE)
- return -EINVAL;
- pInfo->priority = arg & 0xff;
- return 0;
- case R3964_USE_BCC:
- if (arg)
- pInfo->flags |= R3964_BCC;
- else
- pInfo->flags &= ~R3964_BCC;
- return 0;
- case R3964_READ_TELEGRAM:
- return read_telegram(pInfo, task_pid(current),
- (unsigned char __user *)arg);
- default:
- return -ENOIOCTLCMD;
- }
-}
-
-static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old)
-{
- TRACE_L("set_termios");
-}
-
-/* Called without the kernel lock held - fine */
-static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
- struct poll_table_struct *wait)
-{
- struct r3964_info *pInfo = tty->disc_data;
- struct r3964_client_info *pClient;
- struct r3964_message *pMsg = NULL;
- unsigned long flags;
- int result = POLLOUT;
-
- TRACE_L("POLL");
-
- pClient = findClient(pInfo, task_pid(current));
- if (pClient) {
- poll_wait(file, &pInfo->read_wait, wait);
- spin_lock_irqsave(&pInfo->lock, flags);
- pMsg = pClient->first_msg;
- spin_unlock_irqrestore(&pInfo->lock, flags);
- if (pMsg)
- result |= POLLIN | POLLRDNORM;
- } else {
- result = -EINVAL;
- }
- return result;
-}
-
-static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
- char *fp, int count)
-{
- struct r3964_info *pInfo = tty->disc_data;
- const unsigned char *p;
- char *f, flags = 0;
- int i;
-
- for (i = count, p = cp, f = fp; i; i--, p++) {
- if (f)
- flags = *f++;
- if (flags == TTY_NORMAL) {
- receive_char(pInfo, *p);
- } else {
- receive_error(pInfo, flags);
- }
-
- }
-}
-
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_LDISC(N_R3964);
+++ /dev/null
-/*
- * n_tty.c --- implements the N_TTY line discipline.
- *
- * This code used to be in tty_io.c, but things are getting hairy
- * enough that it made sense to split things off. (The N_TTY
- * processing has changed so much that it's hardly recognizable,
- * anyway...)
- *
- * Note that the open routine for N_TTY is guaranteed never to return
- * an error. This is because Linux will fall back to setting a line
- * to N_TTY if it can not switch to any other line discipline.
- *
- * Written by Theodore Ts'o, Copyright 1994.
- *
- * This file also contains code originally written by Linus Torvalds,
- * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994.
- *
- * This file may be redistributed under the terms of the GNU General Public
- * License.
- *
- * Reduced memory usage for older ARM systems - Russell King.
- *
- * 2000/01/20 Fixed SMP locking on put_tty_queue using bits of
- * the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu>
- * who actually finally proved there really was a race.
- *
- * 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to
- * waiting writing processes-Sapan Bhatia <sapan@corewars.org>.
- * Also fixed a bug in BLOCKING mode where n_tty_write returns
- * EAGAIN
- */
-
-#include <linux/types.h>
-#include <linux/major.h>
-#include <linux/errno.h>
-#include <linux/signal.h>
-#include <linux/fcntl.h>
-#include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/tty.h>
-#include <linux/timer.h>
-#include <linux/ctype.h>
-#include <linux/mm.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/poll.h>
-#include <linux/bitops.h>
-#include <linux/audit.h>
-#include <linux/file.h>
-#include <linux/uaccess.h>
-#include <linux/module.h>
-
-#include <asm/system.h>
-
-/* number of characters left in xmit buffer before select has we have room */
-#define WAKEUP_CHARS 256
-
-/*
- * This defines the low- and high-watermarks for throttling and
- * unthrottling the TTY driver. These watermarks are used for
- * controlling the space in the read buffer.
- */
-#define TTY_THRESHOLD_THROTTLE 128 /* now based on remaining room */
-#define TTY_THRESHOLD_UNTHROTTLE 128
-
-/*
- * Special byte codes used in the echo buffer to represent operations
- * or special handling of characters. Bytes in the echo buffer that
- * are not part of such special blocks are treated as normal character
- * codes.
- */
-#define ECHO_OP_START 0xff
-#define ECHO_OP_MOVE_BACK_COL 0x80
-#define ECHO_OP_SET_CANON_COL 0x81
-#define ECHO_OP_ERASE_TAB 0x82
-
-static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
- unsigned char __user *ptr)
-{
- tty_audit_add_data(tty, &x, 1);
- return put_user(x, ptr);
-}
-
-/**
- * n_tty_set__room - receive space
- * @tty: terminal
- *
- * Called by the driver to find out how much data it is
- * permitted to feed to the line discipline without any being lost
- * and thus to manage flow control. Not serialized. Answers for the
- * "instant".
- */
-
-static void n_tty_set_room(struct tty_struct *tty)
-{
- /* tty->read_cnt is not read locked ? */
- int left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
-
- /*
- * If we are doing input canonicalization, and there are no
- * pending newlines, let characters through without limit, so
- * that erase characters will be handled. Other excess
- * characters will be beeped.
- */
- if (left <= 0)
- left = tty->icanon && !tty->canon_data;
- tty->receive_room = left;
-}
-
-static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty)
-{
- if (tty->read_cnt < N_TTY_BUF_SIZE) {
- tty->read_buf[tty->read_head] = c;
- tty->read_head = (tty->read_head + 1) & (N_TTY_BUF_SIZE-1);
- tty->read_cnt++;
- }
-}
-
-/**
- * put_tty_queue - add character to tty
- * @c: character
- * @tty: tty device
- *
- * Add a character to the tty read_buf queue. This is done under the
- * read_lock to serialize character addition and also to protect us
- * against parallel reads or flushes
- */
-
-static void put_tty_queue(unsigned char c, struct tty_struct *tty)
-{
- unsigned long flags;
- /*
- * The problem of stomping on the buffers ends here.
- * Why didn't anyone see this one coming? --AJK
- */
- spin_lock_irqsave(&tty->read_lock, flags);
- put_tty_queue_nolock(c, tty);
- spin_unlock_irqrestore(&tty->read_lock, flags);
-}
-
-/**
- * check_unthrottle - allow new receive data
- * @tty; tty device
- *
- * Check whether to call the driver unthrottle functions
- *
- * Can sleep, may be called under the atomic_read_lock mutex but
- * this is not guaranteed.
- */
-static void check_unthrottle(struct tty_struct *tty)
-{
- if (tty->count)
- tty_unthrottle(tty);
-}
-
-/**
- * reset_buffer_flags - reset buffer state
- * @tty: terminal to reset
- *
- * Reset the read buffer counters, clear the flags,
- * and make sure the driver is unthrottled. Called
- * from n_tty_open() and n_tty_flush_buffer().
- *
- * Locking: tty_read_lock for read fields.
- */
-
-static void reset_buffer_flags(struct tty_struct *tty)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&tty->read_lock, flags);
- tty->read_head = tty->read_tail = tty->read_cnt = 0;
- spin_unlock_irqrestore(&tty->read_lock, flags);
-
- mutex_lock(&tty->echo_lock);
- tty->echo_pos = tty->echo_cnt = tty->echo_overrun = 0;
- mutex_unlock(&tty->echo_lock);
-
- tty->canon_head = tty->canon_data = tty->erasing = 0;
- memset(&tty->read_flags, 0, sizeof tty->read_flags);
- n_tty_set_room(tty);
- check_unthrottle(tty);
-}
-
-/**
- * n_tty_flush_buffer - clean input queue
- * @tty: terminal device
- *
- * Flush the input buffer. Called when the line discipline is
- * being closed, when the tty layer wants the buffer flushed (eg
- * at hangup) or when the N_TTY line discipline internally has to
- * clean the pending queue (for example some signals).
- *
- * Locking: ctrl_lock, read_lock.
- */
-
-static void n_tty_flush_buffer(struct tty_struct *tty)
-{
- unsigned long flags;
- /* clear everything and unthrottle the driver */
- reset_buffer_flags(tty);
-
- if (!tty->link)
- return;
-
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- if (tty->link->packet) {
- tty->ctrl_status |= TIOCPKT_FLUSHREAD;
- wake_up_interruptible(&tty->link->read_wait);
- }
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-}
-
-/**
- * n_tty_chars_in_buffer - report available bytes
- * @tty: tty device
- *
- * Report the number of characters buffered to be delivered to user
- * at this instant in time.
- *
- * Locking: read_lock
- */
-
-static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
-{
- unsigned long flags;
- ssize_t n = 0;
-
- spin_lock_irqsave(&tty->read_lock, flags);
- if (!tty->icanon) {
- n = tty->read_cnt;
- } else if (tty->canon_data) {
- n = (tty->canon_head > tty->read_tail) ?
- tty->canon_head - tty->read_tail :
- tty->canon_head + (N_TTY_BUF_SIZE - tty->read_tail);
- }
- spin_unlock_irqrestore(&tty->read_lock, flags);
- return n;
-}
-
-/**
- * is_utf8_continuation - utf8 multibyte check
- * @c: byte to check
- *
- * Returns true if the utf8 character 'c' is a multibyte continuation
- * character. We use this to correctly compute the on screen size
- * of the character when printing
- */
-
-static inline int is_utf8_continuation(unsigned char c)
-{
- return (c & 0xc0) == 0x80;
-}
-
-/**
- * is_continuation - multibyte check
- * @c: byte to check
- *
- * Returns true if the utf8 character 'c' is a multibyte continuation
- * character and the terminal is in unicode mode.
- */
-
-static inline int is_continuation(unsigned char c, struct tty_struct *tty)
-{
- return I_IUTF8(tty) && is_utf8_continuation(c);
-}
-
-/**
- * do_output_char - output one character
- * @c: character (or partial unicode symbol)
- * @tty: terminal device
- * @space: space available in tty driver write buffer
- *
- * This is a helper function that handles one output character
- * (including special characters like TAB, CR, LF, etc.),
- * doing OPOST processing and putting the results in the
- * tty driver's write buffer.
- *
- * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY
- * and NLDLY. They simply aren't relevant in the world today.
- * If you ever need them, add them here.
- *
- * Returns the number of bytes of buffer space used or -1 if
- * no space left.
- *
- * Locking: should be called under the output_lock to protect
- * the column state and space left in the buffer
- */
-
-static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
-{
- int spaces;
-
- if (!space)
- return -1;
-
- switch (c) {
- case '\n':
- if (O_ONLRET(tty))
- tty->column = 0;
- if (O_ONLCR(tty)) {
- if (space < 2)
- return -1;
- tty->canon_column = tty->column = 0;
- tty->ops->write(tty, "\r\n", 2);
- return 2;
- }
- tty->canon_column = tty->column;
- break;
- case '\r':
- if (O_ONOCR(tty) && tty->column == 0)
- return 0;
- if (O_OCRNL(tty)) {
- c = '\n';
- if (O_ONLRET(tty))
- tty->canon_column = tty->column = 0;
- break;
- }
- tty->canon_column = tty->column = 0;
- break;
- case '\t':
- spaces = 8 - (tty->column & 7);
- if (O_TABDLY(tty) == XTABS) {
- if (space < spaces)
- return -1;
- tty->column += spaces;
- tty->ops->write(tty, " ", spaces);
- return spaces;
- }
- tty->column += spaces;
- break;
- case '\b':
- if (tty->column > 0)
- tty->column--;
- break;
- default:
- if (!iscntrl(c)) {
- if (O_OLCUC(tty))
- c = toupper(c);
- if (!is_continuation(c, tty))
- tty->column++;
- }
- break;
- }
-
- tty_put_char(tty, c);
- return 1;
-}
-
-/**
- * process_output - output post processor
- * @c: character (or partial unicode symbol)
- * @tty: terminal device
- *
- * Output one character with OPOST processing.
- * Returns -1 when the output device is full and the character
- * must be retried.
- *
- * Locking: output_lock to protect column state and space left
- * (also, this is called from n_tty_write under the
- * tty layer write lock)
- */
-
-static int process_output(unsigned char c, struct tty_struct *tty)
-{
- int space, retval;
-
- mutex_lock(&tty->output_lock);
-
- space = tty_write_room(tty);
- retval = do_output_char(c, tty, space);
-
- mutex_unlock(&tty->output_lock);
- if (retval < 0)
- return -1;
- else
- return 0;
-}
-
-/**
- * process_output_block - block post processor
- * @tty: terminal device
- * @buf: character buffer
- * @nr: number of bytes to output
- *
- * Output a block of characters with OPOST processing.
- * Returns the number of characters output.
- *
- * This path is used to speed up block console writes, among other
- * things when processing blocks of output data. It handles only
- * the simple cases normally found and helps to generate blocks of
- * symbols for the console driver and thus improve performance.
- *
- * Locking: output_lock to protect column state and space left
- * (also, this is called from n_tty_write under the
- * tty layer write lock)
- */
-
-static ssize_t process_output_block(struct tty_struct *tty,
- const unsigned char *buf, unsigned int nr)
-{
- int space;
- int i;
- const unsigned char *cp;
-
- mutex_lock(&tty->output_lock);
-
- space = tty_write_room(tty);
- if (!space) {
- mutex_unlock(&tty->output_lock);
- return 0;
- }
- if (nr > space)
- nr = space;
-
- for (i = 0, cp = buf; i < nr; i++, cp++) {
- unsigned char c = *cp;
-
- switch (c) {
- case '\n':
- if (O_ONLRET(tty))
- tty->column = 0;
- if (O_ONLCR(tty))
- goto break_out;
- tty->canon_column = tty->column;
- break;
- case '\r':
- if (O_ONOCR(tty) && tty->column == 0)
- goto break_out;
- if (O_OCRNL(tty))
- goto break_out;
- tty->canon_column = tty->column = 0;
- break;
- case '\t':
- goto break_out;
- case '\b':
- if (tty->column > 0)
- tty->column--;
- break;
- default:
- if (!iscntrl(c)) {
- if (O_OLCUC(tty))
- goto break_out;
- if (!is_continuation(c, tty))
- tty->column++;
- }
- break;
- }
- }
-break_out:
- i = tty->ops->write(tty, buf, i);
-
- mutex_unlock(&tty->output_lock);
- return i;
-}
-
-/**
- * process_echoes - write pending echo characters
- * @tty: terminal device
- *
- * Write previously buffered echo (and other ldisc-generated)
- * characters to the tty.
- *
- * Characters generated by the ldisc (including echoes) need to
- * be buffered because the driver's write buffer can fill during
- * heavy program output. Echoing straight to the driver will
- * often fail under these conditions, causing lost characters and
- * resulting mismatches of ldisc state information.
- *
- * Since the ldisc state must represent the characters actually sent
- * to the driver at the time of the write, operations like certain
- * changes in column state are also saved in the buffer and executed
- * here.
- *
- * A circular fifo buffer is used so that the most recent characters
- * are prioritized. Also, when control characters are echoed with a
- * prefixed "^", the pair is treated atomically and thus not separated.
- *
- * Locking: output_lock to protect column state and space left,
- * echo_lock to protect the echo buffer
- */
-
-static void process_echoes(struct tty_struct *tty)
-{
- int space, nr;
- unsigned char c;
- unsigned char *cp, *buf_end;
-
- if (!tty->echo_cnt)
- return;
-
- mutex_lock(&tty->output_lock);
- mutex_lock(&tty->echo_lock);
-
- space = tty_write_room(tty);
-
- buf_end = tty->echo_buf + N_TTY_BUF_SIZE;
- cp = tty->echo_buf + tty->echo_pos;
- nr = tty->echo_cnt;
- while (nr > 0) {
- c = *cp;
- if (c == ECHO_OP_START) {
- unsigned char op;
- unsigned char *opp;
- int no_space_left = 0;
-
- /*
- * If the buffer byte is the start of a multi-byte
- * operation, get the next byte, which is either the
- * op code or a control character value.
- */
- opp = cp + 1;
- if (opp == buf_end)
- opp -= N_TTY_BUF_SIZE;
- op = *opp;
-
- switch (op) {
- unsigned int num_chars, num_bs;
-
- case ECHO_OP_ERASE_TAB:
- if (++opp == buf_end)
- opp -= N_TTY_BUF_SIZE;
- num_chars = *opp;
-
- /*
- * Determine how many columns to go back
- * in order to erase the tab.
- * This depends on the number of columns
- * used by other characters within the tab
- * area. If this (modulo 8) count is from
- * the start of input rather than from a
- * previous tab, we offset by canon column.
- * Otherwise, tab spacing is normal.
- */
- if (!(num_chars & 0x80))
- num_chars += tty->canon_column;
- num_bs = 8 - (num_chars & 7);
-
- if (num_bs > space) {
- no_space_left = 1;
- break;
- }
- space -= num_bs;
- while (num_bs--) {
- tty_put_char(tty, '\b');
- if (tty->column > 0)
- tty->column--;
- }
- cp += 3;
- nr -= 3;
- break;
-
- case ECHO_OP_SET_CANON_COL:
- tty->canon_column = tty->column;
- cp += 2;
- nr -= 2;
- break;
-
- case ECHO_OP_MOVE_BACK_COL:
- if (tty->column > 0)
- tty->column--;
- cp += 2;
- nr -= 2;
- break;
-
- case ECHO_OP_START:
- /* This is an escaped echo op start code */
- if (!space) {
- no_space_left = 1;
- break;
- }
- tty_put_char(tty, ECHO_OP_START);
- tty->column++;
- space--;
- cp += 2;
- nr -= 2;
- break;
-
- default:
- /*
- * If the op is not a special byte code,
- * it is a ctrl char tagged to be echoed
- * as "^X" (where X is the letter
- * representing the control char).
- * Note that we must ensure there is
- * enough space for the whole ctrl pair.
- *
- */
- if (space < 2) {
- no_space_left = 1;
- break;
- }
- tty_put_char(tty, '^');
- tty_put_char(tty, op ^ 0100);
- tty->column += 2;
- space -= 2;
- cp += 2;
- nr -= 2;
- }
-
- if (no_space_left)
- break;
- } else {
- if (O_OPOST(tty) &&
- !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
- int retval = do_output_char(c, tty, space);
- if (retval < 0)
- break;
- space -= retval;
- } else {
- if (!space)
- break;
- tty_put_char(tty, c);
- space -= 1;
- }
- cp += 1;
- nr -= 1;
- }
-
- /* When end of circular buffer reached, wrap around */
- if (cp >= buf_end)
- cp -= N_TTY_BUF_SIZE;
- }
-
- if (nr == 0) {
- tty->echo_pos = 0;
- tty->echo_cnt = 0;
- tty->echo_overrun = 0;
- } else {
- int num_processed = tty->echo_cnt - nr;
- tty->echo_pos += num_processed;
- tty->echo_pos &= N_TTY_BUF_SIZE - 1;
- tty->echo_cnt = nr;
- if (num_processed > 0)
- tty->echo_overrun = 0;
- }
-
- mutex_unlock(&tty->echo_lock);
- mutex_unlock(&tty->output_lock);
-
- if (tty->ops->flush_chars)
- tty->ops->flush_chars(tty);
-}
-
-/**
- * add_echo_byte - add a byte to the echo buffer
- * @c: unicode byte to echo
- * @tty: terminal device
- *
- * Add a character or operation byte to the echo buffer.
- *
- * Should be called under the echo lock to protect the echo buffer.
- */
-
-static void add_echo_byte(unsigned char c, struct tty_struct *tty)
-{
- int new_byte_pos;
-
- if (tty->echo_cnt == N_TTY_BUF_SIZE) {
- /* Circular buffer is already at capacity */
- new_byte_pos = tty->echo_pos;
-
- /*
- * Since the buffer start position needs to be advanced,
- * be sure to step by a whole operation byte group.
- */
- if (tty->echo_buf[tty->echo_pos] == ECHO_OP_START) {
- if (tty->echo_buf[(tty->echo_pos + 1) &
- (N_TTY_BUF_SIZE - 1)] ==
- ECHO_OP_ERASE_TAB) {
- tty->echo_pos += 3;
- tty->echo_cnt -= 2;
- } else {
- tty->echo_pos += 2;
- tty->echo_cnt -= 1;
- }
- } else {
- tty->echo_pos++;
- }
- tty->echo_pos &= N_TTY_BUF_SIZE - 1;
-
- tty->echo_overrun = 1;
- } else {
- new_byte_pos = tty->echo_pos + tty->echo_cnt;
- new_byte_pos &= N_TTY_BUF_SIZE - 1;
- tty->echo_cnt++;
- }
-
- tty->echo_buf[new_byte_pos] = c;
-}
-
-/**
- * echo_move_back_col - add operation to move back a column
- * @tty: terminal device
- *
- * Add an operation to the echo buffer to move back one column.
- *
- * Locking: echo_lock to protect the echo buffer
- */
-
-static void echo_move_back_col(struct tty_struct *tty)
-{
- mutex_lock(&tty->echo_lock);
-
- add_echo_byte(ECHO_OP_START, tty);
- add_echo_byte(ECHO_OP_MOVE_BACK_COL, tty);
-
- mutex_unlock(&tty->echo_lock);
-}
-
-/**
- * echo_set_canon_col - add operation to set the canon column
- * @tty: terminal device
- *
- * Add an operation to the echo buffer to set the canon column
- * to the current column.
- *
- * Locking: echo_lock to protect the echo buffer
- */
-
-static void echo_set_canon_col(struct tty_struct *tty)
-{
- mutex_lock(&tty->echo_lock);
-
- add_echo_byte(ECHO_OP_START, tty);
- add_echo_byte(ECHO_OP_SET_CANON_COL, tty);
-
- mutex_unlock(&tty->echo_lock);
-}
-
-/**
- * echo_erase_tab - add operation to erase a tab
- * @num_chars: number of character columns already used
- * @after_tab: true if num_chars starts after a previous tab
- * @tty: terminal device
- *
- * Add an operation to the echo buffer to erase a tab.
- *
- * Called by the eraser function, which knows how many character
- * columns have been used since either a previous tab or the start
- * of input. This information will be used later, along with
- * canon column (if applicable), to go back the correct number
- * of columns.
- *
- * Locking: echo_lock to protect the echo buffer
- */
-
-static void echo_erase_tab(unsigned int num_chars, int after_tab,
- struct tty_struct *tty)
-{
- mutex_lock(&tty->echo_lock);
-
- add_echo_byte(ECHO_OP_START, tty);
- add_echo_byte(ECHO_OP_ERASE_TAB, tty);
-
- /* We only need to know this modulo 8 (tab spacing) */
- num_chars &= 7;
-
- /* Set the high bit as a flag if num_chars is after a previous tab */
- if (after_tab)
- num_chars |= 0x80;
-
- add_echo_byte(num_chars, tty);
-
- mutex_unlock(&tty->echo_lock);
-}
-
-/**
- * echo_char_raw - echo a character raw
- * @c: unicode byte to echo
- * @tty: terminal device
- *
- * Echo user input back onto the screen. This must be called only when
- * L_ECHO(tty) is true. Called from the driver receive_buf path.
- *
- * This variant does not treat control characters specially.
- *
- * Locking: echo_lock to protect the echo buffer
- */
-
-static void echo_char_raw(unsigned char c, struct tty_struct *tty)
-{
- mutex_lock(&tty->echo_lock);
-
- if (c == ECHO_OP_START) {
- add_echo_byte(ECHO_OP_START, tty);
- add_echo_byte(ECHO_OP_START, tty);
- } else {
- add_echo_byte(c, tty);
- }
-
- mutex_unlock(&tty->echo_lock);
-}
-
-/**
- * echo_char - echo a character
- * @c: unicode byte to echo
- * @tty: terminal device
- *
- * Echo user input back onto the screen. This must be called only when
- * L_ECHO(tty) is true. Called from the driver receive_buf path.
- *
- * This variant tags control characters to be echoed as "^X"
- * (where X is the letter representing the control char).
- *
- * Locking: echo_lock to protect the echo buffer
- */
-
-static void echo_char(unsigned char c, struct tty_struct *tty)
-{
- mutex_lock(&tty->echo_lock);
-
- if (c == ECHO_OP_START) {
- add_echo_byte(ECHO_OP_START, tty);
- add_echo_byte(ECHO_OP_START, tty);
- } else {
- if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t')
- add_echo_byte(ECHO_OP_START, tty);
- add_echo_byte(c, tty);
- }
-
- mutex_unlock(&tty->echo_lock);
-}
-
-/**
- * finish_erasing - complete erase
- * @tty: tty doing the erase
- */
-
-static inline void finish_erasing(struct tty_struct *tty)
-{
- if (tty->erasing) {
- echo_char_raw('/', tty);
- tty->erasing = 0;
- }
-}
-
-/**
- * eraser - handle erase function
- * @c: character input
- * @tty: terminal device
- *
- * Perform erase and necessary output when an erase character is
- * present in the stream from the driver layer. Handles the complexities
- * of UTF-8 multibyte symbols.
- *
- * Locking: read_lock for tty buffers
- */
-
-static void eraser(unsigned char c, struct tty_struct *tty)
-{
- enum { ERASE, WERASE, KILL } kill_type;
- int head, seen_alnums, cnt;
- unsigned long flags;
-
- /* FIXME: locking needed ? */
- if (tty->read_head == tty->canon_head) {
- /* process_output('\a', tty); */ /* what do you think? */
- return;
- }
- if (c == ERASE_CHAR(tty))
- kill_type = ERASE;
- else if (c == WERASE_CHAR(tty))
- kill_type = WERASE;
- else {
- if (!L_ECHO(tty)) {
- spin_lock_irqsave(&tty->read_lock, flags);
- tty->read_cnt -= ((tty->read_head - tty->canon_head) &
- (N_TTY_BUF_SIZE - 1));
- tty->read_head = tty->canon_head;
- spin_unlock_irqrestore(&tty->read_lock, flags);
- return;
- }
- if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) {
- spin_lock_irqsave(&tty->read_lock, flags);
- tty->read_cnt -= ((tty->read_head - tty->canon_head) &
- (N_TTY_BUF_SIZE - 1));
- tty->read_head = tty->canon_head;
- spin_unlock_irqrestore(&tty->read_lock, flags);
- finish_erasing(tty);
- echo_char(KILL_CHAR(tty), tty);
- /* Add a newline if ECHOK is on and ECHOKE is off. */
- if (L_ECHOK(tty))
- echo_char_raw('\n', tty);
- return;
- }
- kill_type = KILL;
- }
-
- seen_alnums = 0;
- /* FIXME: Locking ?? */
- while (tty->read_head != tty->canon_head) {
- head = tty->read_head;
-
- /* erase a single possibly multibyte character */
- do {
- head = (head - 1) & (N_TTY_BUF_SIZE-1);
- c = tty->read_buf[head];
- } while (is_continuation(c, tty) && head != tty->canon_head);
-
- /* do not partially erase */
- if (is_continuation(c, tty))
- break;
-
- if (kill_type == WERASE) {
- /* Equivalent to BSD's ALTWERASE. */
- if (isalnum(c) || c == '_')
- seen_alnums++;
- else if (seen_alnums)
- break;
- }
- cnt = (tty->read_head - head) & (N_TTY_BUF_SIZE-1);
- spin_lock_irqsave(&tty->read_lock, flags);
- tty->read_head = head;
- tty->read_cnt -= cnt;
- spin_unlock_irqrestore(&tty->read_lock, flags);
- if (L_ECHO(tty)) {
- if (L_ECHOPRT(tty)) {
- if (!tty->erasing) {
- echo_char_raw('\\', tty);
- tty->erasing = 1;
- }
- /* if cnt > 1, output a multi-byte character */
- echo_char(c, tty);
- while (--cnt > 0) {
- head = (head+1) & (N_TTY_BUF_SIZE-1);
- echo_char_raw(tty->read_buf[head], tty);
- echo_move_back_col(tty);
- }
- } else if (kill_type == ERASE && !L_ECHOE(tty)) {
- echo_char(ERASE_CHAR(tty), tty);
- } else if (c == '\t') {
- unsigned int num_chars = 0;
- int after_tab = 0;
- unsigned long tail = tty->read_head;
-
- /*
- * Count the columns used for characters
- * since the start of input or after a
- * previous tab.
- * This info is used to go back the correct
- * number of columns.
- */
- while (tail != tty->canon_head) {
- tail = (tail-1) & (N_TTY_BUF_SIZE-1);
- c = tty->read_buf[tail];
- if (c == '\t') {
- after_tab = 1;
- break;
- } else if (iscntrl(c)) {
- if (L_ECHOCTL(tty))
- num_chars += 2;
- } else if (!is_continuation(c, tty)) {
- num_chars++;
- }
- }
- echo_erase_tab(num_chars, after_tab, tty);
- } else {
- if (iscntrl(c) && L_ECHOCTL(tty)) {
- echo_char_raw('\b', tty);
- echo_char_raw(' ', tty);
- echo_char_raw('\b', tty);
- }
- if (!iscntrl(c) || L_ECHOCTL(tty)) {
- echo_char_raw('\b', tty);
- echo_char_raw(' ', tty);
- echo_char_raw('\b', tty);
- }
- }
- }
- if (kill_type == ERASE)
- break;
- }
- if (tty->read_head == tty->canon_head && L_ECHO(tty))
- finish_erasing(tty);
-}
-
-/**
- * isig - handle the ISIG optio
- * @sig: signal
- * @tty: terminal
- * @flush: force flush
- *
- * Called when a signal is being sent due to terminal input. This
- * may caus terminal flushing to take place according to the termios
- * settings and character used. Called from the driver receive_buf
- * path so serialized.
- *
- * Locking: ctrl_lock, read_lock (both via flush buffer)
- */
-
-static inline void isig(int sig, struct tty_struct *tty, int flush)
-{
- if (tty->pgrp)
- kill_pgrp(tty->pgrp, sig, 1);
- if (flush || !L_NOFLSH(tty)) {
- n_tty_flush_buffer(tty);
- tty_driver_flush_buffer(tty);
- }
-}
-
-/**
- * n_tty_receive_break - handle break
- * @tty: terminal
- *
- * An RS232 break event has been hit in the incoming bitstream. This
- * can cause a variety of events depending upon the termios settings.
- *
- * Called from the receive_buf path so single threaded.
- */
-
-static inline void n_tty_receive_break(struct tty_struct *tty)
-{
- if (I_IGNBRK(tty))
- return;
- if (I_BRKINT(tty)) {
- isig(SIGINT, tty, 1);
- return;
- }
- if (I_PARMRK(tty)) {
- put_tty_queue('\377', tty);
- put_tty_queue('\0', tty);
- }
- put_tty_queue('\0', tty);
- wake_up_interruptible(&tty->read_wait);
-}
-
-/**
- * n_tty_receive_overrun - handle overrun reporting
- * @tty: terminal
- *
- * Data arrived faster than we could process it. While the tty
- * driver has flagged this the bits that were missed are gone
- * forever.
- *
- * Called from the receive_buf path so single threaded. Does not
- * need locking as num_overrun and overrun_time are function
- * private.
- */
-
-static inline void n_tty_receive_overrun(struct tty_struct *tty)
-{
- char buf[64];
-
- tty->num_overrun++;
- if (time_before(tty->overrun_time, jiffies - HZ) ||
- time_after(tty->overrun_time, jiffies)) {
- printk(KERN_WARNING "%s: %d input overrun(s)\n",
- tty_name(tty, buf),
- tty->num_overrun);
- tty->overrun_time = jiffies;
- tty->num_overrun = 0;
- }
-}
-
-/**
- * n_tty_receive_parity_error - error notifier
- * @tty: terminal device
- * @c: character
- *
- * Process a parity error and queue the right data to indicate
- * the error case if necessary. Locking as per n_tty_receive_buf.
- */
-static inline void n_tty_receive_parity_error(struct tty_struct *tty,
- unsigned char c)
-{
- if (I_IGNPAR(tty))
- return;
- if (I_PARMRK(tty)) {
- put_tty_queue('\377', tty);
- put_tty_queue('\0', tty);
- put_tty_queue(c, tty);
- } else if (I_INPCK(tty))
- put_tty_queue('\0', tty);
- else
- put_tty_queue(c, tty);
- wake_up_interruptible(&tty->read_wait);
-}
-
-/**
- * n_tty_receive_char - perform processing
- * @tty: terminal device
- * @c: character
- *
- * Process an individual character of input received from the driver.
- * This is serialized with respect to itself by the rules for the
- * driver above.
- */
-
-static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
-{
- unsigned long flags;
- int parmrk;
-
- if (tty->raw) {
- put_tty_queue(c, tty);
- return;
- }
-
- if (I_ISTRIP(tty))
- c &= 0x7f;
- if (I_IUCLC(tty) && L_IEXTEN(tty))
- c = tolower(c);
-
- if (L_EXTPROC(tty)) {
- put_tty_queue(c, tty);
- return;
- }
-
- if (tty->stopped && !tty->flow_stopped && I_IXON(tty) &&
- I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty) &&
- c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && c != SUSP_CHAR(tty)) {
- start_tty(tty);
- process_echoes(tty);
- }
-
- if (tty->closing) {
- if (I_IXON(tty)) {
- if (c == START_CHAR(tty)) {
- start_tty(tty);
- process_echoes(tty);
- } else if (c == STOP_CHAR(tty))
- stop_tty(tty);
- }
- return;
- }
-
- /*
- * If the previous character was LNEXT, or we know that this
- * character is not one of the characters that we'll have to
- * handle specially, do shortcut processing to speed things
- * up.
- */
- if (!test_bit(c, tty->process_char_map) || tty->lnext) {
- tty->lnext = 0;
- parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
- if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
- /* beep if no space */
- if (L_ECHO(tty))
- process_output('\a', tty);
- return;
- }
- if (L_ECHO(tty)) {
- finish_erasing(tty);
- /* Record the column of first canon char. */
- if (tty->canon_head == tty->read_head)
- echo_set_canon_col(tty);
- echo_char(c, tty);
- process_echoes(tty);
- }
- if (parmrk)
- put_tty_queue(c, tty);
- put_tty_queue(c, tty);
- return;
- }
-
- if (I_IXON(tty)) {
- if (c == START_CHAR(tty)) {
- start_tty(tty);
- process_echoes(tty);
- return;
- }
- if (c == STOP_CHAR(tty)) {
- stop_tty(tty);
- return;
- }
- }
-
- if (L_ISIG(tty)) {
- int signal;
- signal = SIGINT;
- if (c == INTR_CHAR(tty))
- goto send_signal;
- signal = SIGQUIT;
- if (c == QUIT_CHAR(tty))
- goto send_signal;
- signal = SIGTSTP;
- if (c == SUSP_CHAR(tty)) {
-send_signal:
- /*
- * Note that we do not use isig() here because we want
- * the order to be:
- * 1) flush, 2) echo, 3) signal
- */
- if (!L_NOFLSH(tty)) {
- n_tty_flush_buffer(tty);
- tty_driver_flush_buffer(tty);
- }
- if (I_IXON(tty))
- start_tty(tty);
- if (L_ECHO(tty)) {
- echo_char(c, tty);
- process_echoes(tty);
- }
- if (tty->pgrp)
- kill_pgrp(tty->pgrp, signal, 1);
- return;
- }
- }
-
- if (c == '\r') {
- if (I_IGNCR(tty))
- return;
- if (I_ICRNL(tty))
- c = '\n';
- } else if (c == '\n' && I_INLCR(tty))
- c = '\r';
-
- if (tty->icanon) {
- if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
- (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
- eraser(c, tty);
- process_echoes(tty);
- return;
- }
- if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
- tty->lnext = 1;
- if (L_ECHO(tty)) {
- finish_erasing(tty);
- if (L_ECHOCTL(tty)) {
- echo_char_raw('^', tty);
- echo_char_raw('\b', tty);
- process_echoes(tty);
- }
- }
- return;
- }
- if (c == REPRINT_CHAR(tty) && L_ECHO(tty) &&
- L_IEXTEN(tty)) {
- unsigned long tail = tty->canon_head;
-
- finish_erasing(tty);
- echo_char(c, tty);
- echo_char_raw('\n', tty);
- while (tail != tty->read_head) {
- echo_char(tty->read_buf[tail], tty);
- tail = (tail+1) & (N_TTY_BUF_SIZE-1);
- }
- process_echoes(tty);
- return;
- }
- if (c == '\n') {
- if (tty->read_cnt >= N_TTY_BUF_SIZE) {
- if (L_ECHO(tty))
- process_output('\a', tty);
- return;
- }
- if (L_ECHO(tty) || L_ECHONL(tty)) {
- echo_char_raw('\n', tty);
- process_echoes(tty);
- }
- goto handle_newline;
- }
- if (c == EOF_CHAR(tty)) {
- if (tty->read_cnt >= N_TTY_BUF_SIZE)
- return;
- if (tty->canon_head != tty->read_head)
- set_bit(TTY_PUSH, &tty->flags);
- c = __DISABLED_CHAR;
- goto handle_newline;
- }
- if ((c == EOL_CHAR(tty)) ||
- (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
- parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty))
- ? 1 : 0;
- if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk)) {
- if (L_ECHO(tty))
- process_output('\a', tty);
- return;
- }
- /*
- * XXX are EOL_CHAR and EOL2_CHAR echoed?!?
- */
- if (L_ECHO(tty)) {
- /* Record the column of first canon char. */
- if (tty->canon_head == tty->read_head)
- echo_set_canon_col(tty);
- echo_char(c, tty);
- process_echoes(tty);
- }
- /*
- * XXX does PARMRK doubling happen for
- * EOL_CHAR and EOL2_CHAR?
- */
- if (parmrk)
- put_tty_queue(c, tty);
-
-handle_newline:
- spin_lock_irqsave(&tty->read_lock, flags);
- set_bit(tty->read_head, tty->read_flags);
- put_tty_queue_nolock(c, tty);
- tty->canon_head = tty->read_head;
- tty->canon_data++;
- spin_unlock_irqrestore(&tty->read_lock, flags);
- kill_fasync(&tty->fasync, SIGIO, POLL_IN);
- if (waitqueue_active(&tty->read_wait))
- wake_up_interruptible(&tty->read_wait);
- return;
- }
- }
-
- parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
- if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
- /* beep if no space */
- if (L_ECHO(tty))
- process_output('\a', tty);
- return;
- }
- if (L_ECHO(tty)) {
- finish_erasing(tty);
- if (c == '\n')
- echo_char_raw('\n', tty);
- else {
- /* Record the column of first canon char. */
- if (tty->canon_head == tty->read_head)
- echo_set_canon_col(tty);
- echo_char(c, tty);
- }
- process_echoes(tty);
- }
-
- if (parmrk)
- put_tty_queue(c, tty);
-
- put_tty_queue(c, tty);
-}
-
-
-/**
- * n_tty_write_wakeup - asynchronous I/O notifier
- * @tty: tty device
- *
- * Required for the ptys, serial driver etc. since processes
- * that attach themselves to the master and rely on ASYNC
- * IO must be woken up
- */
-
-static void n_tty_write_wakeup(struct tty_struct *tty)
-{
- if (tty->fasync && test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags))
- kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
-}
-
-/**
- * n_tty_receive_buf - data receive
- * @tty: terminal device
- * @cp: buffer
- * @fp: flag buffer
- * @count: characters
- *
- * Called by the terminal driver when a block of characters has
- * been received. This function must be called from soft contexts
- * not from interrupt context. The driver is responsible for making
- * calls one at a time and in order (or using flush_to_ldisc)
- */
-
-static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
- char *fp, int count)
-{
- const unsigned char *p;
- char *f, flags = TTY_NORMAL;
- int i;
- char buf[64];
- unsigned long cpuflags;
-
- if (!tty->read_buf)
- return;
-
- if (tty->real_raw) {
- spin_lock_irqsave(&tty->read_lock, cpuflags);
- i = min(N_TTY_BUF_SIZE - tty->read_cnt,
- N_TTY_BUF_SIZE - tty->read_head);
- i = min(count, i);
- memcpy(tty->read_buf + tty->read_head, cp, i);
- tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
- tty->read_cnt += i;
- cp += i;
- count -= i;
-
- i = min(N_TTY_BUF_SIZE - tty->read_cnt,
- N_TTY_BUF_SIZE - tty->read_head);
- i = min(count, i);
- memcpy(tty->read_buf + tty->read_head, cp, i);
- tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
- tty->read_cnt += i;
- spin_unlock_irqrestore(&tty->read_lock, cpuflags);
- } else {
- for (i = count, p = cp, f = fp; i; i--, p++) {
- if (f)
- flags = *f++;
- switch (flags) {
- case TTY_NORMAL:
- n_tty_receive_char(tty, *p);
- break;
- case TTY_BREAK:
- n_tty_receive_break(tty);
- break;
- case TTY_PARITY:
- case TTY_FRAME:
- n_tty_receive_parity_error(tty, *p);
- break;
- case TTY_OVERRUN:
- n_tty_receive_overrun(tty);
- break;
- default:
- printk(KERN_ERR "%s: unknown flag %d\n",
- tty_name(tty, buf), flags);
- break;
- }
- }
- if (tty->ops->flush_chars)
- tty->ops->flush_chars(tty);
- }
-
- n_tty_set_room(tty);
-
- if ((!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) ||
- L_EXTPROC(tty)) {
- kill_fasync(&tty->fasync, SIGIO, POLL_IN);
- if (waitqueue_active(&tty->read_wait))
- wake_up_interruptible(&tty->read_wait);
- }
-
- /*
- * Check the remaining room for the input canonicalization
- * mode. We don't want to throttle the driver if we're in
- * canonical mode and don't have a newline yet!
- */
- if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
- tty_throttle(tty);
-}
-
-int is_ignored(int sig)
-{
- return (sigismember(¤t->blocked, sig) ||
- current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
-}
-
-/**
- * n_tty_set_termios - termios data changed
- * @tty: terminal
- * @old: previous data
- *
- * Called by the tty layer when the user changes termios flags so
- * that the line discipline can plan ahead. This function cannot sleep
- * and is protected from re-entry by the tty layer. The user is
- * guaranteed that this function will not be re-entered or in progress
- * when the ldisc is closed.
- *
- * Locking: Caller holds tty->termios_mutex
- */
-
-static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
-{
- int canon_change = 1;
- BUG_ON(!tty);
-
- if (old)
- canon_change = (old->c_lflag ^ tty->termios->c_lflag) & ICANON;
- if (canon_change) {
- memset(&tty->read_flags, 0, sizeof tty->read_flags);
- tty->canon_head = tty->read_tail;
- tty->canon_data = 0;
- tty->erasing = 0;
- }
-
- if (canon_change && !L_ICANON(tty) && tty->read_cnt)
- wake_up_interruptible(&tty->read_wait);
-
- tty->icanon = (L_ICANON(tty) != 0);
- if (test_bit(TTY_HW_COOK_IN, &tty->flags)) {
- tty->raw = 1;
- tty->real_raw = 1;
- n_tty_set_room(tty);
- return;
- }
- if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) ||
- I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) ||
- I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) ||
- I_PARMRK(tty)) {
- memset(tty->process_char_map, 0, 256/8);
-
- if (I_IGNCR(tty) || I_ICRNL(tty))
- set_bit('\r', tty->process_char_map);
- if (I_INLCR(tty))
- set_bit('\n', tty->process_char_map);
-
- if (L_ICANON(tty)) {
- set_bit(ERASE_CHAR(tty), tty->process_char_map);
- set_bit(KILL_CHAR(tty), tty->process_char_map);
- set_bit(EOF_CHAR(tty), tty->process_char_map);
- set_bit('\n', tty->process_char_map);
- set_bit(EOL_CHAR(tty), tty->process_char_map);
- if (L_IEXTEN(tty)) {
- set_bit(WERASE_CHAR(tty),
- tty->process_char_map);
- set_bit(LNEXT_CHAR(tty),
- tty->process_char_map);
- set_bit(EOL2_CHAR(tty),
- tty->process_char_map);
- if (L_ECHO(tty))
- set_bit(REPRINT_CHAR(tty),
- tty->process_char_map);
- }
- }
- if (I_IXON(tty)) {
- set_bit(START_CHAR(tty), tty->process_char_map);
- set_bit(STOP_CHAR(tty), tty->process_char_map);
- }
- if (L_ISIG(tty)) {
- set_bit(INTR_CHAR(tty), tty->process_char_map);
- set_bit(QUIT_CHAR(tty), tty->process_char_map);
- set_bit(SUSP_CHAR(tty), tty->process_char_map);
- }
- clear_bit(__DISABLED_CHAR, tty->process_char_map);
- tty->raw = 0;
- tty->real_raw = 0;
- } else {
- tty->raw = 1;
- if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) &&
- (I_IGNPAR(tty) || !I_INPCK(tty)) &&
- (tty->driver->flags & TTY_DRIVER_REAL_RAW))
- tty->real_raw = 1;
- else
- tty->real_raw = 0;
- }
- n_tty_set_room(tty);
- /* The termios change make the tty ready for I/O */
- wake_up_interruptible(&tty->write_wait);
- wake_up_interruptible(&tty->read_wait);
-}
-
-/**
- * n_tty_close - close the ldisc for this tty
- * @tty: device
- *
- * Called from the terminal layer when this line discipline is
- * being shut down, either because of a close or becsuse of a
- * discipline change. The function will not be called while other
- * ldisc methods are in progress.
- */
-
-static void n_tty_close(struct tty_struct *tty)
-{
- n_tty_flush_buffer(tty);
- if (tty->read_buf) {
- kfree(tty->read_buf);
- tty->read_buf = NULL;
- }
- if (tty->echo_buf) {
- kfree(tty->echo_buf);
- tty->echo_buf = NULL;
- }
-}
-
-/**
- * n_tty_open - open an ldisc
- * @tty: terminal to open
- *
- * Called when this line discipline is being attached to the
- * terminal device. Can sleep. Called serialized so that no
- * other events will occur in parallel. No further open will occur
- * until a close.
- */
-
-static int n_tty_open(struct tty_struct *tty)
-{
- if (!tty)
- return -EINVAL;
-
- /* These are ugly. Currently a malloc failure here can panic */
- if (!tty->read_buf) {
- tty->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
- if (!tty->read_buf)
- return -ENOMEM;
- }
- if (!tty->echo_buf) {
- tty->echo_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
-
- if (!tty->echo_buf)
- return -ENOMEM;
- }
- reset_buffer_flags(tty);
- tty->column = 0;
- n_tty_set_termios(tty, NULL);
- tty->minimum_to_wake = 1;
- tty->closing = 0;
- return 0;
-}
-
-static inline int input_available_p(struct tty_struct *tty, int amt)
-{
- tty_flush_to_ldisc(tty);
- if (tty->icanon && !L_EXTPROC(tty)) {
- if (tty->canon_data)
- return 1;
- } else if (tty->read_cnt >= (amt ? amt : 1))
- return 1;
-
- return 0;
-}
-
-/**
- * copy_from_read_buf - copy read data directly
- * @tty: terminal device
- * @b: user data
- * @nr: size of data
- *
- * Helper function to speed up n_tty_read. It is only called when
- * ICANON is off; it copies characters straight from the tty queue to
- * user space directly. It can be profitably called twice; once to
- * drain the space from the tail pointer to the (physical) end of the
- * buffer, and once to drain the space from the (physical) beginning of
- * the buffer to head pointer.
- *
- * Called under the tty->atomic_read_lock sem
- *
- */
-
-static int copy_from_read_buf(struct tty_struct *tty,
- unsigned char __user **b,
- size_t *nr)
-
-{
- int retval;
- size_t n;
- unsigned long flags;
-
- retval = 0;
- spin_lock_irqsave(&tty->read_lock, flags);
- n = min(tty->read_cnt, N_TTY_BUF_SIZE - tty->read_tail);
- n = min(*nr, n);
- spin_unlock_irqrestore(&tty->read_lock, flags);
- if (n) {
- retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n);
- n -= retval;
- tty_audit_add_data(tty, &tty->read_buf[tty->read_tail], n);
- spin_lock_irqsave(&tty->read_lock, flags);
- tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1);
- tty->read_cnt -= n;
- /* Turn single EOF into zero-length read */
- if (L_EXTPROC(tty) && tty->icanon && n == 1) {
- if (!tty->read_cnt && (*b)[n-1] == EOF_CHAR(tty))
- n--;
- }
- spin_unlock_irqrestore(&tty->read_lock, flags);
- *b += n;
- *nr -= n;
- }
- return retval;
-}
-
-extern ssize_t redirected_tty_write(struct file *, const char __user *,
- size_t, loff_t *);
-
-/**
- * job_control - check job control
- * @tty: tty
- * @file: file handle
- *
- * Perform job control management checks on this file/tty descriptor
- * and if appropriate send any needed signals and return a negative
- * error code if action should be taken.
- *
- * FIXME:
- * Locking: None - redirected write test is safe, testing
- * current->signal should possibly lock current->sighand
- * pgrp locking ?
- */
-
-static int job_control(struct tty_struct *tty, struct file *file)
-{
- /* Job control check -- must be done at start and after
- every sleep (POSIX.1 7.1.1.4). */
- /* NOTE: not yet done after every sleep pending a thorough
- check of the logic of this change. -- jlc */
- /* don't stop on /dev/console */
- if (file->f_op->write != redirected_tty_write &&
- current->signal->tty == tty) {
- if (!tty->pgrp)
- printk(KERN_ERR "n_tty_read: no tty->pgrp!\n");
- else if (task_pgrp(current) != tty->pgrp) {
- if (is_ignored(SIGTTIN) ||
- is_current_pgrp_orphaned())
- return -EIO;
- kill_pgrp(task_pgrp(current), SIGTTIN, 1);
- set_thread_flag(TIF_SIGPENDING);
- return -ERESTARTSYS;
- }
- }
- return 0;
-}
-
-
-/**
- * n_tty_read - read function for tty
- * @tty: tty device
- * @file: file object
- * @buf: userspace buffer pointer
- * @nr: size of I/O
- *
- * Perform reads for the line discipline. We are guaranteed that the
- * line discipline will not be closed under us but we may get multiple
- * parallel readers and must handle this ourselves. We may also get
- * a hangup. Always called in user context, may sleep.
- *
- * This code must be sure never to sleep through a hangup.
- */
-
-static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
- unsigned char __user *buf, size_t nr)
-{
- unsigned char __user *b = buf;
- DECLARE_WAITQUEUE(wait, current);
- int c;
- int minimum, time;
- ssize_t retval = 0;
- ssize_t size;
- long timeout;
- unsigned long flags;
- int packet;
-
-do_it_again:
-
- BUG_ON(!tty->read_buf);
-
- c = job_control(tty, file);
- if (c < 0)
- return c;
-
- minimum = time = 0;
- timeout = MAX_SCHEDULE_TIMEOUT;
- if (!tty->icanon) {
- time = (HZ / 10) * TIME_CHAR(tty);
- minimum = MIN_CHAR(tty);
- if (minimum) {
- if (time)
- tty->minimum_to_wake = 1;
- else if (!waitqueue_active(&tty->read_wait) ||
- (tty->minimum_to_wake > minimum))
- tty->minimum_to_wake = minimum;
- } else {
- timeout = 0;
- if (time) {
- timeout = time;
- time = 0;
- }
- tty->minimum_to_wake = minimum = 1;
- }
- }
-
- /*
- * Internal serialization of reads.
- */
- if (file->f_flags & O_NONBLOCK) {
- if (!mutex_trylock(&tty->atomic_read_lock))
- return -EAGAIN;
- } else {
- if (mutex_lock_interruptible(&tty->atomic_read_lock))
- return -ERESTARTSYS;
- }
- packet = tty->packet;
-
- add_wait_queue(&tty->read_wait, &wait);
- while (nr) {
- /* First test for status change. */
- if (packet && tty->link->ctrl_status) {
- unsigned char cs;
- if (b != buf)
- break;
- spin_lock_irqsave(&tty->link->ctrl_lock, flags);
- cs = tty->link->ctrl_status;
- tty->link->ctrl_status = 0;
- spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
- if (tty_put_user(tty, cs, b++)) {
- retval = -EFAULT;
- b--;
- break;
- }
- nr--;
- break;
- }
- /* This statement must be first before checking for input
- so that any interrupt will set the state back to
- TASK_RUNNING. */
- set_current_state(TASK_INTERRUPTIBLE);
-
- if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
- ((minimum - (b - buf)) >= 1))
- tty->minimum_to_wake = (minimum - (b - buf));
-
- if (!input_available_p(tty, 0)) {
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
- retval = -EIO;
- break;
- }
- if (tty_hung_up_p(file))
- break;
- if (!timeout)
- break;
- if (file->f_flags & O_NONBLOCK) {
- retval = -EAGAIN;
- break;
- }
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
- /* FIXME: does n_tty_set_room need locking ? */
- n_tty_set_room(tty);
- timeout = schedule_timeout(timeout);
- continue;
- }
- __set_current_state(TASK_RUNNING);
-
- /* Deal with packet mode. */
- if (packet && b == buf) {
- if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
- retval = -EFAULT;
- b--;
- break;
- }
- nr--;
- }
-
- if (tty->icanon && !L_EXTPROC(tty)) {
- /* N.B. avoid overrun if nr == 0 */
- while (nr && tty->read_cnt) {
- int eol;
-
- eol = test_and_clear_bit(tty->read_tail,
- tty->read_flags);
- c = tty->read_buf[tty->read_tail];
- spin_lock_irqsave(&tty->read_lock, flags);
- tty->read_tail = ((tty->read_tail+1) &
- (N_TTY_BUF_SIZE-1));
- tty->read_cnt--;
- if (eol) {
- /* this test should be redundant:
- * we shouldn't be reading data if
- * canon_data is 0
- */
- if (--tty->canon_data < 0)
- tty->canon_data = 0;
- }
- spin_unlock_irqrestore(&tty->read_lock, flags);
-
- if (!eol || (c != __DISABLED_CHAR)) {
- if (tty_put_user(tty, c, b++)) {
- retval = -EFAULT;
- b--;
- break;
- }
- nr--;
- }
- if (eol) {
- tty_audit_push(tty);
- break;
- }
- }
- if (retval)
- break;
- } else {
- int uncopied;
- /* The copy function takes the read lock and handles
- locking internally for this case */
- uncopied = copy_from_read_buf(tty, &b, &nr);
- uncopied += copy_from_read_buf(tty, &b, &nr);
- if (uncopied) {
- retval = -EFAULT;
- break;
- }
- }
-
- /* If there is enough space in the read buffer now, let the
- * low-level driver know. We use n_tty_chars_in_buffer() to
- * check the buffer, as it now knows about canonical mode.
- * Otherwise, if the driver is throttled and the line is
- * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
- * we won't get any more characters.
- */
- if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) {
- n_tty_set_room(tty);
- check_unthrottle(tty);
- }
-
- if (b - buf >= minimum)
- break;
- if (time)
- timeout = time;
- }
- mutex_unlock(&tty->atomic_read_lock);
- remove_wait_queue(&tty->read_wait, &wait);
-
- if (!waitqueue_active(&tty->read_wait))
- tty->minimum_to_wake = minimum;
-
- __set_current_state(TASK_RUNNING);
- size = b - buf;
- if (size) {
- retval = size;
- if (nr)
- clear_bit(TTY_PUSH, &tty->flags);
- } else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
- goto do_it_again;
-
- n_tty_set_room(tty);
- return retval;
-}
-
-/**
- * n_tty_write - write function for tty
- * @tty: tty device
- * @file: file object
- * @buf: userspace buffer pointer
- * @nr: size of I/O
- *
- * Write function of the terminal device. This is serialized with
- * respect to other write callers but not to termios changes, reads
- * and other such events. Since the receive code will echo characters,
- * thus calling driver write methods, the output_lock is used in
- * the output processing functions called here as well as in the
- * echo processing function to protect the column state and space
- * left in the buffer.
- *
- * This code must be sure never to sleep through a hangup.
- *
- * Locking: output_lock to protect column state and space left
- * (note that the process_output*() functions take this
- * lock themselves)
- */
-
-static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
- const unsigned char *buf, size_t nr)
-{
- const unsigned char *b = buf;
- DECLARE_WAITQUEUE(wait, current);
- int c;
- ssize_t retval = 0;
-
- /* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
- if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) {
- retval = tty_check_change(tty);
- if (retval)
- return retval;
- }
-
- /* Write out any echoed characters that are still pending */
- process_echoes(tty);
-
- add_wait_queue(&tty->write_wait, &wait);
- while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
- if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
- retval = -EIO;
- break;
- }
- if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
- while (nr > 0) {
- ssize_t num = process_output_block(tty, b, nr);
- if (num < 0) {
- if (num == -EAGAIN)
- break;
- retval = num;
- goto break_out;
- }
- b += num;
- nr -= num;
- if (nr == 0)
- break;
- c = *b;
- if (process_output(c, tty) < 0)
- break;
- b++; nr--;
- }
- if (tty->ops->flush_chars)
- tty->ops->flush_chars(tty);
- } else {
- while (nr > 0) {
- c = tty->ops->write(tty, b, nr);
- if (c < 0) {
- retval = c;
- goto break_out;
- }
- if (!c)
- break;
- b += c;
- nr -= c;
- }
- }
- if (!nr)
- break;
- if (file->f_flags & O_NONBLOCK) {
- retval = -EAGAIN;
- break;
- }
- schedule();
- }
-break_out:
- __set_current_state(TASK_RUNNING);
- remove_wait_queue(&tty->write_wait, &wait);
- if (b - buf != nr && tty->fasync)
- set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- return (b - buf) ? b - buf : retval;
-}
-
-/**
- * n_tty_poll - poll method for N_TTY
- * @tty: terminal device
- * @file: file accessing it
- * @wait: poll table
- *
- * Called when the line discipline is asked to poll() for data or
- * for special events. This code is not serialized with respect to
- * other events save open/close.
- *
- * This code must be sure never to sleep through a hangup.
- * Called without the kernel lock held - fine
- */
-
-static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
- poll_table *wait)
-{
- unsigned int mask = 0;
-
- poll_wait(file, &tty->read_wait, wait);
- poll_wait(file, &tty->write_wait, wait);
- if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty)))
- mask |= POLLIN | POLLRDNORM;
- if (tty->packet && tty->link->ctrl_status)
- mask |= POLLPRI | POLLIN | POLLRDNORM;
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
- mask |= POLLHUP;
- if (tty_hung_up_p(file))
- mask |= POLLHUP;
- if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) {
- if (MIN_CHAR(tty) && !TIME_CHAR(tty))
- tty->minimum_to_wake = MIN_CHAR(tty);
- else
- tty->minimum_to_wake = 1;
- }
- if (tty->ops->write && !tty_is_writelocked(tty) &&
- tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
- tty_write_room(tty) > 0)
- mask |= POLLOUT | POLLWRNORM;
- return mask;
-}
-
-static unsigned long inq_canon(struct tty_struct *tty)
-{
- int nr, head, tail;
-
- if (!tty->canon_data)
- return 0;
- head = tty->canon_head;
- tail = tty->read_tail;
- nr = (head - tail) & (N_TTY_BUF_SIZE-1);
- /* Skip EOF-chars.. */
- while (head != tail) {
- if (test_bit(tail, tty->read_flags) &&
- tty->read_buf[tail] == __DISABLED_CHAR)
- nr--;
- tail = (tail+1) & (N_TTY_BUF_SIZE-1);
- }
- return nr;
-}
-
-static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- int retval;
-
- switch (cmd) {
- case TIOCOUTQ:
- return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
- case TIOCINQ:
- /* FIXME: Locking */
- retval = tty->read_cnt;
- if (L_ICANON(tty))
- retval = inq_canon(tty);
- return put_user(retval, (unsigned int __user *) arg);
- default:
- return n_tty_ioctl_helper(tty, file, cmd, arg);
- }
-}
-
-struct tty_ldisc_ops tty_ldisc_N_TTY = {
- .magic = TTY_LDISC_MAGIC,
- .name = "n_tty",
- .open = n_tty_open,
- .close = n_tty_close,
- .flush_buffer = n_tty_flush_buffer,
- .chars_in_buffer = n_tty_chars_in_buffer,
- .read = n_tty_read,
- .write = n_tty_write,
- .ioctl = n_tty_ioctl,
- .set_termios = n_tty_set_termios,
- .poll = n_tty_poll,
- .receive_buf = n_tty_receive_buf,
- .write_wakeup = n_tty_write_wakeup
-};
-
-/**
- * n_tty_inherit_ops - inherit N_TTY methods
- * @ops: struct tty_ldisc_ops where to save N_TTY methods
- *
- * Used by a generic struct tty_ldisc_ops to easily inherit N_TTY
- * methods.
- */
-
-void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
-{
- *ops = tty_ldisc_N_TTY;
- ops->owner = NULL;
- ops->refcount = ops->flags = 0;
-}
-EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
+++ /dev/null
-/*
- * linux/drivers/char/pty.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- *
- * Added support for a Unix98-style ptmx device.
- * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
- *
- * When reading this code see also fs/devpts. In particular note that the
- * driver_data field is used by the devpts side as a binding to the devpts
- * inode.
- */
-
-#include <linux/module.h>
-
-#include <linux/errno.h>
-#include <linux/interrupt.h>
-#include <linux/tty.h>
-#include <linux/tty_flip.h>
-#include <linux/fcntl.h>
-#include <linux/sched.h>
-#include <linux/string.h>
-#include <linux/major.h>
-#include <linux/mm.h>
-#include <linux/init.h>
-#include <linux/smp_lock.h>
-#include <linux/sysctl.h>
-#include <linux/device.h>
-#include <linux/uaccess.h>
-#include <linux/bitops.h>
-#include <linux/devpts_fs.h>
-#include <linux/slab.h>
-
-#include <asm/system.h>
-
-#ifdef CONFIG_UNIX98_PTYS
-static struct tty_driver *ptm_driver;
-static struct tty_driver *pts_driver;
-#endif
-
-static void pty_close(struct tty_struct *tty, struct file *filp)
-{
- BUG_ON(!tty);
- if (tty->driver->subtype == PTY_TYPE_MASTER)
- WARN_ON(tty->count > 1);
- else {
- if (tty->count > 2)
- return;
- }
- wake_up_interruptible(&tty->read_wait);
- wake_up_interruptible(&tty->write_wait);
- tty->packet = 0;
- if (!tty->link)
- return;
- tty->link->packet = 0;
- set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
- wake_up_interruptible(&tty->link->read_wait);
- wake_up_interruptible(&tty->link->write_wait);
- if (tty->driver->subtype == PTY_TYPE_MASTER) {
- set_bit(TTY_OTHER_CLOSED, &tty->flags);
-#ifdef CONFIG_UNIX98_PTYS
- if (tty->driver == ptm_driver)
- devpts_pty_kill(tty->link);
-#endif
- tty_unlock();
- tty_vhangup(tty->link);
- tty_lock();
- }
-}
-
-/*
- * The unthrottle routine is called by the line discipline to signal
- * that it can receive more characters. For PTY's, the TTY_THROTTLED
- * flag is always set, to force the line discipline to always call the
- * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
- * characters in the queue. This is necessary since each time this
- * happens, we need to wake up any sleeping processes that could be
- * (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
- * for the pty buffer to be drained.
- */
-static void pty_unthrottle(struct tty_struct *tty)
-{
- tty_wakeup(tty->link);
- set_bit(TTY_THROTTLED, &tty->flags);
-}
-
-/**
- * pty_space - report space left for writing
- * @to: tty we are writing into
- *
- * The tty buffers allow 64K but we sneak a peak and clip at 8K this
- * allows a lot of overspill room for echo and other fun messes to
- * be handled properly
- */
-
-static int pty_space(struct tty_struct *to)
-{
- int n = 8192 - to->buf.memory_used;
- if (n < 0)
- return 0;
- return n;
-}
-
-/**
- * pty_write - write to a pty
- * @tty: the tty we write from
- * @buf: kernel buffer of data
- * @count: bytes to write
- *
- * Our "hardware" write method. Data is coming from the ldisc which
- * may be in a non sleeping state. We simply throw this at the other
- * end of the link as if we were an IRQ handler receiving stuff for
- * the other side of the pty/tty pair.
- */
-
-static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
-{
- struct tty_struct *to = tty->link;
-
- if (tty->stopped)
- return 0;
-
- if (c > 0) {
- /* Stuff the data into the input queue of the other end */
- c = tty_insert_flip_string(to, buf, c);
- /* And shovel */
- if (c) {
- tty_flip_buffer_push(to);
- tty_wakeup(tty);
- }
- }
- return c;
-}
-
-/**
- * pty_write_room - write space
- * @tty: tty we are writing from
- *
- * Report how many bytes the ldisc can send into the queue for
- * the other device.
- */
-
-static int pty_write_room(struct tty_struct *tty)
-{
- if (tty->stopped)
- return 0;
- return pty_space(tty->link);
-}
-
-/**
- * pty_chars_in_buffer - characters currently in our tx queue
- * @tty: our tty
- *
- * Report how much we have in the transmit queue. As everything is
- * instantly at the other end this is easy to implement.
- */
-
-static int pty_chars_in_buffer(struct tty_struct *tty)
-{
- return 0;
-}
-
-/* Set the lock flag on a pty */
-static int pty_set_lock(struct tty_struct *tty, int __user *arg)
-{
- int val;
- if (get_user(val, arg))
- return -EFAULT;
- if (val)
- set_bit(TTY_PTY_LOCK, &tty->flags);
- else
- clear_bit(TTY_PTY_LOCK, &tty->flags);
- return 0;
-}
-
-/* Send a signal to the slave */
-static int pty_signal(struct tty_struct *tty, int sig)
-{
- unsigned long flags;
- struct pid *pgrp;
-
- if (tty->link) {
- spin_lock_irqsave(&tty->link->ctrl_lock, flags);
- pgrp = get_pid(tty->link->pgrp);
- spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
-
- kill_pgrp(pgrp, sig, 1);
- put_pid(pgrp);
- }
- return 0;
-}
-
-static void pty_flush_buffer(struct tty_struct *tty)
-{
- struct tty_struct *to = tty->link;
- unsigned long flags;
-
- if (!to)
- return;
- /* tty_buffer_flush(to); FIXME */
- if (to->packet) {
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
- wake_up_interruptible(&to->read_wait);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- }
-}
-
-static int pty_open(struct tty_struct *tty, struct file *filp)
-{
- int retval = -ENODEV;
-
- if (!tty || !tty->link)
- goto out;
-
- retval = -EIO;
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
- goto out;
- if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
- goto out;
- if (tty->link->count != 1)
- goto out;
-
- clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
- set_bit(TTY_THROTTLED, &tty->flags);
- retval = 0;
-out:
- return retval;
-}
-
-static void pty_set_termios(struct tty_struct *tty,
- struct ktermios *old_termios)
-{
- tty->termios->c_cflag &= ~(CSIZE | PARENB);
- tty->termios->c_cflag |= (CS8 | CREAD);
-}
-
-/**
- * pty_do_resize - resize event
- * @tty: tty being resized
- * @ws: window size being set.
- *
- * Update the termios variables and send the necessary signals to
- * peform a terminal resize correctly
- */
-
-int pty_resize(struct tty_struct *tty, struct winsize *ws)
-{
- struct pid *pgrp, *rpgrp;
- unsigned long flags;
- struct tty_struct *pty = tty->link;
-
- /* For a PTY we need to lock the tty side */
- mutex_lock(&tty->termios_mutex);
- if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
- goto done;
-
- /* Get the PID values and reference them so we can
- avoid holding the tty ctrl lock while sending signals.
- We need to lock these individually however. */
-
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- pgrp = get_pid(tty->pgrp);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-
- spin_lock_irqsave(&pty->ctrl_lock, flags);
- rpgrp = get_pid(pty->pgrp);
- spin_unlock_irqrestore(&pty->ctrl_lock, flags);
-
- if (pgrp)
- kill_pgrp(pgrp, SIGWINCH, 1);
- if (rpgrp != pgrp && rpgrp)
- kill_pgrp(rpgrp, SIGWINCH, 1);
-
- put_pid(pgrp);
- put_pid(rpgrp);
-
- tty->winsize = *ws;
- pty->winsize = *ws; /* Never used so will go away soon */
-done:
- mutex_unlock(&tty->termios_mutex);
- return 0;
-}
-
-/* Traditional BSD devices */
-#ifdef CONFIG_LEGACY_PTYS
-
-static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
-{
- struct tty_struct *o_tty;
- int idx = tty->index;
- int retval;
-
- o_tty = alloc_tty_struct();
- if (!o_tty)
- return -ENOMEM;
- if (!try_module_get(driver->other->owner)) {
- /* This cannot in fact currently happen */
- free_tty_struct(o_tty);
- return -ENOMEM;
- }
- initialize_tty_struct(o_tty, driver->other, idx);
-
- /* We always use new tty termios data so we can do this
- the easy way .. */
- retval = tty_init_termios(tty);
- if (retval)
- goto free_mem_out;
-
- retval = tty_init_termios(o_tty);
- if (retval) {
- tty_free_termios(tty);
- goto free_mem_out;
- }
-
- /*
- * Everything allocated ... set up the o_tty structure.
- */
- driver->other->ttys[idx] = o_tty;
- tty_driver_kref_get(driver->other);
- if (driver->subtype == PTY_TYPE_MASTER)
- o_tty->count++;
- /* Establish the links in both directions */
- tty->link = o_tty;
- o_tty->link = tty;
-
- tty_driver_kref_get(driver);
- tty->count++;
- driver->ttys[idx] = tty;
- return 0;
-free_mem_out:
- module_put(o_tty->driver->owner);
- free_tty_struct(o_tty);
- return -ENOMEM;
-}
-
-static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- switch (cmd) {
- case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
- return pty_set_lock(tty, (int __user *) arg);
- case TIOCSIG: /* Send signal to other side of pty */
- return pty_signal(tty, (int) arg);
- }
- return -ENOIOCTLCMD;
-}
-
-static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
-module_param(legacy_count, int, 0);
-
-/*
- * The master side of a pty can do TIOCSPTLCK and thus
- * has pty_bsd_ioctl.
- */
-static const struct tty_operations master_pty_ops_bsd = {
- .install = pty_install,
- .open = pty_open,
- .close = pty_close,
- .write = pty_write,
- .write_room = pty_write_room,
- .flush_buffer = pty_flush_buffer,
- .chars_in_buffer = pty_chars_in_buffer,
- .unthrottle = pty_unthrottle,
- .set_termios = pty_set_termios,
- .ioctl = pty_bsd_ioctl,
- .resize = pty_resize
-};
-
-static const struct tty_operations slave_pty_ops_bsd = {
- .install = pty_install,
- .open = pty_open,
- .close = pty_close,
- .write = pty_write,
- .write_room = pty_write_room,
- .flush_buffer = pty_flush_buffer,
- .chars_in_buffer = pty_chars_in_buffer,
- .unthrottle = pty_unthrottle,
- .set_termios = pty_set_termios,
- .resize = pty_resize
-};
-
-static void __init legacy_pty_init(void)
-{
- struct tty_driver *pty_driver, *pty_slave_driver;
-
- if (legacy_count <= 0)
- return;
-
- pty_driver = alloc_tty_driver(legacy_count);
- if (!pty_driver)
- panic("Couldn't allocate pty driver");
-
- pty_slave_driver = alloc_tty_driver(legacy_count);
- if (!pty_slave_driver)
- panic("Couldn't allocate pty slave driver");
-
- pty_driver->owner = THIS_MODULE;
- pty_driver->driver_name = "pty_master";
- pty_driver->name = "pty";
- pty_driver->major = PTY_MASTER_MAJOR;
- pty_driver->minor_start = 0;
- pty_driver->type = TTY_DRIVER_TYPE_PTY;
- pty_driver->subtype = PTY_TYPE_MASTER;
- pty_driver->init_termios = tty_std_termios;
- pty_driver->init_termios.c_iflag = 0;
- pty_driver->init_termios.c_oflag = 0;
- pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
- pty_driver->init_termios.c_lflag = 0;
- pty_driver->init_termios.c_ispeed = 38400;
- pty_driver->init_termios.c_ospeed = 38400;
- pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
- pty_driver->other = pty_slave_driver;
- tty_set_operations(pty_driver, &master_pty_ops_bsd);
-
- pty_slave_driver->owner = THIS_MODULE;
- pty_slave_driver->driver_name = "pty_slave";
- pty_slave_driver->name = "ttyp";
- pty_slave_driver->major = PTY_SLAVE_MAJOR;
- pty_slave_driver->minor_start = 0;
- pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
- pty_slave_driver->subtype = PTY_TYPE_SLAVE;
- pty_slave_driver->init_termios = tty_std_termios;
- pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
- pty_slave_driver->init_termios.c_ispeed = 38400;
- pty_slave_driver->init_termios.c_ospeed = 38400;
- pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
- TTY_DRIVER_REAL_RAW;
- pty_slave_driver->other = pty_driver;
- tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
-
- if (tty_register_driver(pty_driver))
- panic("Couldn't register pty driver");
- if (tty_register_driver(pty_slave_driver))
- panic("Couldn't register pty slave driver");
-}
-#else
-static inline void legacy_pty_init(void) { }
-#endif
-
-/* Unix98 devices */
-#ifdef CONFIG_UNIX98_PTYS
-/*
- * sysctl support for setting limits on the number of Unix98 ptys allocated.
- * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
- */
-int pty_limit = NR_UNIX98_PTY_DEFAULT;
-static int pty_limit_min;
-static int pty_limit_max = NR_UNIX98_PTY_MAX;
-static int pty_count;
-
-static struct cdev ptmx_cdev;
-
-static struct ctl_table pty_table[] = {
- {
- .procname = "max",
- .maxlen = sizeof(int),
- .mode = 0644,
- .data = &pty_limit,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = &pty_limit_min,
- .extra2 = &pty_limit_max,
- }, {
- .procname = "nr",
- .maxlen = sizeof(int),
- .mode = 0444,
- .data = &pty_count,
- .proc_handler = proc_dointvec,
- },
- {}
-};
-
-static struct ctl_table pty_kern_table[] = {
- {
- .procname = "pty",
- .mode = 0555,
- .child = pty_table,
- },
- {}
-};
-
-static struct ctl_table pty_root_table[] = {
- {
- .procname = "kernel",
- .mode = 0555,
- .child = pty_kern_table,
- },
- {}
-};
-
-
-static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- switch (cmd) {
- case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
- return pty_set_lock(tty, (int __user *)arg);
- case TIOCGPTN: /* Get PT Number */
- return put_user(tty->index, (unsigned int __user *)arg);
- case TIOCSIG: /* Send signal to other side of pty */
- return pty_signal(tty, (int) arg);
- }
-
- return -ENOIOCTLCMD;
-}
-
-/**
- * ptm_unix98_lookup - find a pty master
- * @driver: ptm driver
- * @idx: tty index
- *
- * Look up a pty master device. Called under the tty_mutex for now.
- * This provides our locking.
- */
-
-static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
- struct inode *ptm_inode, int idx)
-{
- struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
- if (tty)
- tty = tty->link;
- return tty;
-}
-
-/**
- * pts_unix98_lookup - find a pty slave
- * @driver: pts driver
- * @idx: tty index
- *
- * Look up a pty master device. Called under the tty_mutex for now.
- * This provides our locking.
- */
-
-static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
- struct inode *pts_inode, int idx)
-{
- struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
- /* Master must be open before slave */
- if (!tty)
- return ERR_PTR(-EIO);
- return tty;
-}
-
-static void pty_unix98_shutdown(struct tty_struct *tty)
-{
- /* We have our own method as we don't use the tty index */
- kfree(tty->termios);
-}
-
-/* We have no need to install and remove our tty objects as devpts does all
- the work for us */
-
-static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
-{
- struct tty_struct *o_tty;
- int idx = tty->index;
-
- o_tty = alloc_tty_struct();
- if (!o_tty)
- return -ENOMEM;
- if (!try_module_get(driver->other->owner)) {
- /* This cannot in fact currently happen */
- free_tty_struct(o_tty);
- return -ENOMEM;
- }
- initialize_tty_struct(o_tty, driver->other, idx);
-
- tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
- if (tty->termios == NULL)
- goto free_mem_out;
- *tty->termios = driver->init_termios;
- tty->termios_locked = tty->termios + 1;
-
- o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
- if (o_tty->termios == NULL)
- goto free_mem_out;
- *o_tty->termios = driver->other->init_termios;
- o_tty->termios_locked = o_tty->termios + 1;
-
- tty_driver_kref_get(driver->other);
- if (driver->subtype == PTY_TYPE_MASTER)
- o_tty->count++;
- /* Establish the links in both directions */
- tty->link = o_tty;
- o_tty->link = tty;
- /*
- * All structures have been allocated, so now we install them.
- * Failures after this point use release_tty to clean up, so
- * there's no need to null out the local pointers.
- */
- tty_driver_kref_get(driver);
- tty->count++;
- pty_count++;
- return 0;
-free_mem_out:
- kfree(o_tty->termios);
- module_put(o_tty->driver->owner);
- free_tty_struct(o_tty);
- kfree(tty->termios);
- return -ENOMEM;
-}
-
-static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
-{
- pty_count--;
-}
-
-static const struct tty_operations ptm_unix98_ops = {
- .lookup = ptm_unix98_lookup,
- .install = pty_unix98_install,
- .remove = pty_unix98_remove,
- .open = pty_open,
- .close = pty_close,
- .write = pty_write,
- .write_room = pty_write_room,
- .flush_buffer = pty_flush_buffer,
- .chars_in_buffer = pty_chars_in_buffer,
- .unthrottle = pty_unthrottle,
- .set_termios = pty_set_termios,
- .ioctl = pty_unix98_ioctl,
- .shutdown = pty_unix98_shutdown,
- .resize = pty_resize
-};
-
-static const struct tty_operations pty_unix98_ops = {
- .lookup = pts_unix98_lookup,
- .install = pty_unix98_install,
- .remove = pty_unix98_remove,
- .open = pty_open,
- .close = pty_close,
- .write = pty_write,
- .write_room = pty_write_room,
- .flush_buffer = pty_flush_buffer,
- .chars_in_buffer = pty_chars_in_buffer,
- .unthrottle = pty_unthrottle,
- .set_termios = pty_set_termios,
- .shutdown = pty_unix98_shutdown
-};
-
-/**
- * ptmx_open - open a unix 98 pty master
- * @inode: inode of device file
- * @filp: file pointer to tty
- *
- * Allocate a unix98 pty master device from the ptmx driver.
- *
- * Locking: tty_mutex protects the init_dev work. tty->count should
- * protect the rest.
- * allocated_ptys_lock handles the list of free pty numbers
- */
-
-static int ptmx_open(struct inode *inode, struct file *filp)
-{
- struct tty_struct *tty;
- int retval;
- int index;
-
- nonseekable_open(inode, filp);
-
- /* find a device that is not in use. */
- tty_lock();
- index = devpts_new_index(inode);
- tty_unlock();
- if (index < 0)
- return index;
-
- mutex_lock(&tty_mutex);
- tty_lock();
- tty = tty_init_dev(ptm_driver, index, 1);
- mutex_unlock(&tty_mutex);
-
- if (IS_ERR(tty)) {
- retval = PTR_ERR(tty);
- goto out;
- }
-
- set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
-
- retval = tty_add_file(tty, filp);
- if (retval)
- goto out;
-
- retval = devpts_pty_new(inode, tty->link);
- if (retval)
- goto out1;
-
- retval = ptm_driver->ops->open(tty, filp);
- if (retval)
- goto out2;
-out1:
- tty_unlock();
- return retval;
-out2:
- tty_unlock();
- tty_release(inode, filp);
- return retval;
-out:
- devpts_kill_index(inode, index);
- tty_unlock();
- return retval;
-}
-
-static struct file_operations ptmx_fops;
-
-static void __init unix98_pty_init(void)
-{
- ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
- if (!ptm_driver)
- panic("Couldn't allocate Unix98 ptm driver");
- pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
- if (!pts_driver)
- panic("Couldn't allocate Unix98 pts driver");
-
- ptm_driver->owner = THIS_MODULE;
- ptm_driver->driver_name = "pty_master";
- ptm_driver->name = "ptm";
- ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
- ptm_driver->minor_start = 0;
- ptm_driver->type = TTY_DRIVER_TYPE_PTY;
- ptm_driver->subtype = PTY_TYPE_MASTER;
- ptm_driver->init_termios = tty_std_termios;
- ptm_driver->init_termios.c_iflag = 0;
- ptm_driver->init_termios.c_oflag = 0;
- ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
- ptm_driver->init_termios.c_lflag = 0;
- ptm_driver->init_termios.c_ispeed = 38400;
- ptm_driver->init_termios.c_ospeed = 38400;
- ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
- TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
- ptm_driver->other = pts_driver;
- tty_set_operations(ptm_driver, &ptm_unix98_ops);
-
- pts_driver->owner = THIS_MODULE;
- pts_driver->driver_name = "pty_slave";
- pts_driver->name = "pts";
- pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
- pts_driver->minor_start = 0;
- pts_driver->type = TTY_DRIVER_TYPE_PTY;
- pts_driver->subtype = PTY_TYPE_SLAVE;
- pts_driver->init_termios = tty_std_termios;
- pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
- pts_driver->init_termios.c_ispeed = 38400;
- pts_driver->init_termios.c_ospeed = 38400;
- pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
- TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
- pts_driver->other = ptm_driver;
- tty_set_operations(pts_driver, &pty_unix98_ops);
-
- if (tty_register_driver(ptm_driver))
- panic("Couldn't register Unix98 ptm driver");
- if (tty_register_driver(pts_driver))
- panic("Couldn't register Unix98 pts driver");
-
- register_sysctl_table(pty_root_table);
-
- /* Now create the /dev/ptmx special device */
- tty_default_fops(&ptmx_fops);
- ptmx_fops.open = ptmx_open;
-
- cdev_init(&ptmx_cdev, &ptmx_fops);
- if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
- register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
- panic("Couldn't register /dev/ptmx driver\n");
- device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
-}
-
-#else
-static inline void unix98_pty_init(void) { }
-#endif
-
-static int __init pty_init(void)
-{
- legacy_pty_init();
- unix98_pty_init();
- return 0;
-}
-module_init(pty_init);
+++ /dev/null
-/*
- * Linux Magic System Request Key Hacks
- *
- * (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
- * based on ideas by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>
- *
- * (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
- * overhauled to use key registration
- * based upon discusions in irc://irc.openprojects.net/#kernelnewbies
- *
- * Copyright (c) 2010 Dmitry Torokhov
- * Input handler conversion
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/mount.h>
-#include <linux/kdev_t.h>
-#include <linux/major.h>
-#include <linux/reboot.h>
-#include <linux/sysrq.h>
-#include <linux/kbd_kern.h>
-#include <linux/proc_fs.h>
-#include <linux/nmi.h>
-#include <linux/quotaops.h>
-#include <linux/perf_event.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/suspend.h>
-#include <linux/writeback.h>
-#include <linux/buffer_head.h> /* for fsync_bdev() */
-#include <linux/swap.h>
-#include <linux/spinlock.h>
-#include <linux/vt_kern.h>
-#include <linux/workqueue.h>
-#include <linux/hrtimer.h>
-#include <linux/oom.h>
-#include <linux/slab.h>
-#include <linux/input.h>
-
-#include <asm/ptrace.h>
-#include <asm/irq_regs.h>
-
-/* Whether we react on sysrq keys or just ignore them */
-static int __read_mostly sysrq_enabled = 1;
-static bool __read_mostly sysrq_always_enabled;
-
-static bool sysrq_on(void)
-{
- return sysrq_enabled || sysrq_always_enabled;
-}
-
-/*
- * A value of 1 means 'all', other nonzero values are an op mask:
- */
-static bool sysrq_on_mask(int mask)
-{
- return sysrq_always_enabled ||
- sysrq_enabled == 1 ||
- (sysrq_enabled & mask);
-}
-
-static int __init sysrq_always_enabled_setup(char *str)
-{
- sysrq_always_enabled = true;
- pr_info("sysrq always enabled.\n");
-
- return 1;
-}
-
-__setup("sysrq_always_enabled", sysrq_always_enabled_setup);
-
-
-static void sysrq_handle_loglevel(int key)
-{
- int i;
-
- i = key - '0';
- console_loglevel = 7;
- printk("Loglevel set to %d\n", i);
- console_loglevel = i;
-}
-static struct sysrq_key_op sysrq_loglevel_op = {
- .handler = sysrq_handle_loglevel,
- .help_msg = "loglevel(0-9)",
- .action_msg = "Changing Loglevel",
- .enable_mask = SYSRQ_ENABLE_LOG,
-};
-
-#ifdef CONFIG_VT
-static void sysrq_handle_SAK(int key)
-{
- struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
- schedule_work(SAK_work);
-}
-static struct sysrq_key_op sysrq_SAK_op = {
- .handler = sysrq_handle_SAK,
- .help_msg = "saK",
- .action_msg = "SAK",
- .enable_mask = SYSRQ_ENABLE_KEYBOARD,
-};
-#else
-#define sysrq_SAK_op (*(struct sysrq_key_op *)NULL)
-#endif
-
-#ifdef CONFIG_VT
-static void sysrq_handle_unraw(int key)
-{
- struct kbd_struct *kbd = &kbd_table[fg_console];
-
- if (kbd)
- kbd->kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
-}
-static struct sysrq_key_op sysrq_unraw_op = {
- .handler = sysrq_handle_unraw,
- .help_msg = "unRaw",
- .action_msg = "Keyboard mode set to system default",
- .enable_mask = SYSRQ_ENABLE_KEYBOARD,
-};
-#else
-#define sysrq_unraw_op (*(struct sysrq_key_op *)NULL)
-#endif /* CONFIG_VT */
-
-static void sysrq_handle_crash(int key)
-{
- char *killer = NULL;
-
- panic_on_oops = 1; /* force panic */
- wmb();
- *killer = 1;
-}
-static struct sysrq_key_op sysrq_crash_op = {
- .handler = sysrq_handle_crash,
- .help_msg = "Crash",
- .action_msg = "Trigger a crash",
- .enable_mask = SYSRQ_ENABLE_DUMP,
-};
-
-static void sysrq_handle_reboot(int key)
-{
- lockdep_off();
- local_irq_enable();
- emergency_restart();
-}
-static struct sysrq_key_op sysrq_reboot_op = {
- .handler = sysrq_handle_reboot,
- .help_msg = "reBoot",
- .action_msg = "Resetting",
- .enable_mask = SYSRQ_ENABLE_BOOT,
-};
-
-static void sysrq_handle_sync(int key)
-{
- emergency_sync();
-}
-static struct sysrq_key_op sysrq_sync_op = {
- .handler = sysrq_handle_sync,
- .help_msg = "Sync",
- .action_msg = "Emergency Sync",
- .enable_mask = SYSRQ_ENABLE_SYNC,
-};
-
-static void sysrq_handle_show_timers(int key)
-{
- sysrq_timer_list_show();
-}
-
-static struct sysrq_key_op sysrq_show_timers_op = {
- .handler = sysrq_handle_show_timers,
- .help_msg = "show-all-timers(Q)",
- .action_msg = "Show clockevent devices & pending hrtimers (no others)",
-};
-
-static void sysrq_handle_mountro(int key)
-{
- emergency_remount();
-}
-static struct sysrq_key_op sysrq_mountro_op = {
- .handler = sysrq_handle_mountro,
- .help_msg = "Unmount",
- .action_msg = "Emergency Remount R/O",
- .enable_mask = SYSRQ_ENABLE_REMOUNT,
-};
-
-#ifdef CONFIG_LOCKDEP
-static void sysrq_handle_showlocks(int key)
-{
- debug_show_all_locks();
-}
-
-static struct sysrq_key_op sysrq_showlocks_op = {
- .handler = sysrq_handle_showlocks,
- .help_msg = "show-all-locks(D)",
- .action_msg = "Show Locks Held",
-};
-#else
-#define sysrq_showlocks_op (*(struct sysrq_key_op *)NULL)
-#endif
-
-#ifdef CONFIG_SMP
-static DEFINE_SPINLOCK(show_lock);
-
-static void showacpu(void *dummy)
-{
- unsigned long flags;
-
- /* Idle CPUs have no interesting backtrace. */
- if (idle_cpu(smp_processor_id()))
- return;
-
- spin_lock_irqsave(&show_lock, flags);
- printk(KERN_INFO "CPU%d:\n", smp_processor_id());
- show_stack(NULL, NULL);
- spin_unlock_irqrestore(&show_lock, flags);
-}
-
-static void sysrq_showregs_othercpus(struct work_struct *dummy)
-{
- smp_call_function(showacpu, NULL, 0);
-}
-
-static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus);
-
-static void sysrq_handle_showallcpus(int key)
-{
- /*
- * Fall back to the workqueue based printing if the
- * backtrace printing did not succeed or the
- * architecture has no support for it:
- */
- if (!trigger_all_cpu_backtrace()) {
- struct pt_regs *regs = get_irq_regs();
-
- if (regs) {
- printk(KERN_INFO "CPU%d:\n", smp_processor_id());
- show_regs(regs);
- }
- schedule_work(&sysrq_showallcpus);
- }
-}
-
-static struct sysrq_key_op sysrq_showallcpus_op = {
- .handler = sysrq_handle_showallcpus,
- .help_msg = "show-backtrace-all-active-cpus(L)",
- .action_msg = "Show backtrace of all active CPUs",
- .enable_mask = SYSRQ_ENABLE_DUMP,
-};
-#endif
-
-static void sysrq_handle_showregs(int key)
-{
- struct pt_regs *regs = get_irq_regs();
- if (regs)
- show_regs(regs);
- perf_event_print_debug();
-}
-static struct sysrq_key_op sysrq_showregs_op = {
- .handler = sysrq_handle_showregs,
- .help_msg = "show-registers(P)",
- .action_msg = "Show Regs",
- .enable_mask = SYSRQ_ENABLE_DUMP,
-};
-
-static void sysrq_handle_showstate(int key)
-{
- show_state();
-}
-static struct sysrq_key_op sysrq_showstate_op = {
- .handler = sysrq_handle_showstate,
- .help_msg = "show-task-states(T)",
- .action_msg = "Show State",
- .enable_mask = SYSRQ_ENABLE_DUMP,
-};
-
-static void sysrq_handle_showstate_blocked(int key)
-{
- show_state_filter(TASK_UNINTERRUPTIBLE);
-}
-static struct sysrq_key_op sysrq_showstate_blocked_op = {
- .handler = sysrq_handle_showstate_blocked,
- .help_msg = "show-blocked-tasks(W)",
- .action_msg = "Show Blocked State",
- .enable_mask = SYSRQ_ENABLE_DUMP,
-};
-
-#ifdef CONFIG_TRACING
-#include <linux/ftrace.h>
-
-static void sysrq_ftrace_dump(int key)
-{
- ftrace_dump(DUMP_ALL);
-}
-static struct sysrq_key_op sysrq_ftrace_dump_op = {
- .handler = sysrq_ftrace_dump,
- .help_msg = "dump-ftrace-buffer(Z)",
- .action_msg = "Dump ftrace buffer",
- .enable_mask = SYSRQ_ENABLE_DUMP,
-};
-#else
-#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)NULL)
-#endif
-
-static void sysrq_handle_showmem(int key)
-{
- show_mem();
-}
-static struct sysrq_key_op sysrq_showmem_op = {
- .handler = sysrq_handle_showmem,
- .help_msg = "show-memory-usage(M)",
- .action_msg = "Show Memory",
- .enable_mask = SYSRQ_ENABLE_DUMP,
-};
-
-/*
- * Signal sysrq helper function. Sends a signal to all user processes.
- */
-static void send_sig_all(int sig)
-{
- struct task_struct *p;
-
- for_each_process(p) {
- if (p->mm && !is_global_init(p))
- /* Not swapper, init nor kernel thread */
- force_sig(sig, p);
- }
-}
-
-static void sysrq_handle_term(int key)
-{
- send_sig_all(SIGTERM);
- console_loglevel = 8;
-}
-static struct sysrq_key_op sysrq_term_op = {
- .handler = sysrq_handle_term,
- .help_msg = "terminate-all-tasks(E)",
- .action_msg = "Terminate All Tasks",
- .enable_mask = SYSRQ_ENABLE_SIGNAL,
-};
-
-static void moom_callback(struct work_struct *ignored)
-{
- out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0, NULL);
-}
-
-static DECLARE_WORK(moom_work, moom_callback);
-
-static void sysrq_handle_moom(int key)
-{
- schedule_work(&moom_work);
-}
-static struct sysrq_key_op sysrq_moom_op = {
- .handler = sysrq_handle_moom,
- .help_msg = "memory-full-oom-kill(F)",
- .action_msg = "Manual OOM execution",
- .enable_mask = SYSRQ_ENABLE_SIGNAL,
-};
-
-#ifdef CONFIG_BLOCK
-static void sysrq_handle_thaw(int key)
-{
- emergency_thaw_all();
-}
-static struct sysrq_key_op sysrq_thaw_op = {
- .handler = sysrq_handle_thaw,
- .help_msg = "thaw-filesystems(J)",
- .action_msg = "Emergency Thaw of all frozen filesystems",
- .enable_mask = SYSRQ_ENABLE_SIGNAL,
-};
-#endif
-
-static void sysrq_handle_kill(int key)
-{
- send_sig_all(SIGKILL);
- console_loglevel = 8;
-}
-static struct sysrq_key_op sysrq_kill_op = {
- .handler = sysrq_handle_kill,
- .help_msg = "kill-all-tasks(I)",
- .action_msg = "Kill All Tasks",
- .enable_mask = SYSRQ_ENABLE_SIGNAL,
-};
-
-static void sysrq_handle_unrt(int key)
-{
- normalize_rt_tasks();
-}
-static struct sysrq_key_op sysrq_unrt_op = {
- .handler = sysrq_handle_unrt,
- .help_msg = "nice-all-RT-tasks(N)",
- .action_msg = "Nice All RT Tasks",
- .enable_mask = SYSRQ_ENABLE_RTNICE,
-};
-
-/* Key Operations table and lock */
-static DEFINE_SPINLOCK(sysrq_key_table_lock);
-
-static struct sysrq_key_op *sysrq_key_table[36] = {
- &sysrq_loglevel_op, /* 0 */
- &sysrq_loglevel_op, /* 1 */
- &sysrq_loglevel_op, /* 2 */
- &sysrq_loglevel_op, /* 3 */
- &sysrq_loglevel_op, /* 4 */
- &sysrq_loglevel_op, /* 5 */
- &sysrq_loglevel_op, /* 6 */
- &sysrq_loglevel_op, /* 7 */
- &sysrq_loglevel_op, /* 8 */
- &sysrq_loglevel_op, /* 9 */
-
- /*
- * a: Don't use for system provided sysrqs, it is handled specially on
- * sparc and will never arrive.
- */
- NULL, /* a */
- &sysrq_reboot_op, /* b */
- &sysrq_crash_op, /* c & ibm_emac driver debug */
- &sysrq_showlocks_op, /* d */
- &sysrq_term_op, /* e */
- &sysrq_moom_op, /* f */
- /* g: May be registered for the kernel debugger */
- NULL, /* g */
- NULL, /* h - reserved for help */
- &sysrq_kill_op, /* i */
-#ifdef CONFIG_BLOCK
- &sysrq_thaw_op, /* j */
-#else
- NULL, /* j */
-#endif
- &sysrq_SAK_op, /* k */
-#ifdef CONFIG_SMP
- &sysrq_showallcpus_op, /* l */
-#else
- NULL, /* l */
-#endif
- &sysrq_showmem_op, /* m */
- &sysrq_unrt_op, /* n */
- /* o: This will often be registered as 'Off' at init time */
- NULL, /* o */
- &sysrq_showregs_op, /* p */
- &sysrq_show_timers_op, /* q */
- &sysrq_unraw_op, /* r */
- &sysrq_sync_op, /* s */
- &sysrq_showstate_op, /* t */
- &sysrq_mountro_op, /* u */
- /* v: May be registered for frame buffer console restore */
- NULL, /* v */
- &sysrq_showstate_blocked_op, /* w */
- /* x: May be registered on ppc/powerpc for xmon */
- NULL, /* x */
- /* y: May be registered on sparc64 for global register dump */
- NULL, /* y */
- &sysrq_ftrace_dump_op, /* z */
-};
-
-/* key2index calculation, -1 on invalid index */
-static int sysrq_key_table_key2index(int key)
-{
- int retval;
-
- if ((key >= '0') && (key <= '9'))
- retval = key - '0';
- else if ((key >= 'a') && (key <= 'z'))
- retval = key + 10 - 'a';
- else
- retval = -1;
- return retval;
-}
-
-/*
- * get and put functions for the table, exposed to modules.
- */
-struct sysrq_key_op *__sysrq_get_key_op(int key)
-{
- struct sysrq_key_op *op_p = NULL;
- int i;
-
- i = sysrq_key_table_key2index(key);
- if (i != -1)
- op_p = sysrq_key_table[i];
-
- return op_p;
-}
-
-static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
-{
- int i = sysrq_key_table_key2index(key);
-
- if (i != -1)
- sysrq_key_table[i] = op_p;
-}
-
-void __handle_sysrq(int key, bool check_mask)
-{
- struct sysrq_key_op *op_p;
- int orig_log_level;
- int i;
- unsigned long flags;
-
- spin_lock_irqsave(&sysrq_key_table_lock, flags);
- /*
- * Raise the apparent loglevel to maximum so that the sysrq header
- * is shown to provide the user with positive feedback. We do not
- * simply emit this at KERN_EMERG as that would change message
- * routing in the consumers of /proc/kmsg.
- */
- orig_log_level = console_loglevel;
- console_loglevel = 7;
- printk(KERN_INFO "SysRq : ");
-
- op_p = __sysrq_get_key_op(key);
- if (op_p) {
- /*
- * Should we check for enabled operations (/proc/sysrq-trigger
- * should not) and is the invoked operation enabled?
- */
- if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {
- printk("%s\n", op_p->action_msg);
- console_loglevel = orig_log_level;
- op_p->handler(key);
- } else {
- printk("This sysrq operation is disabled.\n");
- }
- } else {
- printk("HELP : ");
- /* Only print the help msg once per handler */
- for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
- if (sysrq_key_table[i]) {
- int j;
-
- for (j = 0; sysrq_key_table[i] !=
- sysrq_key_table[j]; j++)
- ;
- if (j != i)
- continue;
- printk("%s ", sysrq_key_table[i]->help_msg);
- }
- }
- printk("\n");
- console_loglevel = orig_log_level;
- }
- spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
-}
-
-void handle_sysrq(int key)
-{
- if (sysrq_on())
- __handle_sysrq(key, true);
-}
-EXPORT_SYMBOL(handle_sysrq);
-
-#ifdef CONFIG_INPUT
-
-/* Simple translation table for the SysRq keys */
-static const unsigned char sysrq_xlate[KEY_MAX + 1] =
- "\000\0331234567890-=\177\t" /* 0x00 - 0x0f */
- "qwertyuiop[]\r\000as" /* 0x10 - 0x1f */
- "dfghjkl;'`\000\\zxcv" /* 0x20 - 0x2f */
- "bnm,./\000*\000 \000\201\202\203\204\205" /* 0x30 - 0x3f */
- "\206\207\210\211\212\000\000789-456+1" /* 0x40 - 0x4f */
- "230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */
- "\r\000/"; /* 0x60 - 0x6f */
-
-static bool sysrq_down;
-static int sysrq_alt_use;
-static int sysrq_alt;
-static DEFINE_SPINLOCK(sysrq_event_lock);
-
-static bool sysrq_filter(struct input_handle *handle, unsigned int type,
- unsigned int code, int value)
-{
- bool suppress;
-
- /* We are called with interrupts disabled, just take the lock */
- spin_lock(&sysrq_event_lock);
-
- if (type != EV_KEY)
- goto out;
-
- switch (code) {
-
- case KEY_LEFTALT:
- case KEY_RIGHTALT:
- if (value)
- sysrq_alt = code;
- else {
- if (sysrq_down && code == sysrq_alt_use)
- sysrq_down = false;
-
- sysrq_alt = 0;
- }
- break;
-
- case KEY_SYSRQ:
- if (value == 1 && sysrq_alt) {
- sysrq_down = true;
- sysrq_alt_use = sysrq_alt;
- }
- break;
-
- default:
- if (sysrq_down && value && value != 2)
- __handle_sysrq(sysrq_xlate[code], true);
- break;
- }
-
-out:
- suppress = sysrq_down;
- spin_unlock(&sysrq_event_lock);
-
- return suppress;
-}
-
-static int sysrq_connect(struct input_handler *handler,
- struct input_dev *dev,
- const struct input_device_id *id)
-{
- struct input_handle *handle;
- int error;
-
- sysrq_down = false;
- sysrq_alt = 0;
-
- handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
- if (!handle)
- return -ENOMEM;
-
- handle->dev = dev;
- handle->handler = handler;
- handle->name = "sysrq";
-
- error = input_register_handle(handle);
- if (error) {
- pr_err("Failed to register input sysrq handler, error %d\n",
- error);
- goto err_free;
- }
-
- error = input_open_device(handle);
- if (error) {
- pr_err("Failed to open input device, error %d\n", error);
- goto err_unregister;
- }
-
- return 0;
-
- err_unregister:
- input_unregister_handle(handle);
- err_free:
- kfree(handle);
- return error;
-}
-
-static void sysrq_disconnect(struct input_handle *handle)
-{
- input_close_device(handle);
- input_unregister_handle(handle);
- kfree(handle);
-}
-
-/*
- * We are matching on KEY_LEFTALT instead of KEY_SYSRQ because not all
- * keyboards have SysRq key predefined and so user may add it to keymap
- * later, but we expect all such keyboards to have left alt.
- */
-static const struct input_device_id sysrq_ids[] = {
- {
- .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
- INPUT_DEVICE_ID_MATCH_KEYBIT,
- .evbit = { BIT_MASK(EV_KEY) },
- .keybit = { BIT_MASK(KEY_LEFTALT) },
- },
- { },
-};
-
-static struct input_handler sysrq_handler = {
- .filter = sysrq_filter,
- .connect = sysrq_connect,
- .disconnect = sysrq_disconnect,
- .name = "sysrq",
- .id_table = sysrq_ids,
-};
-
-static bool sysrq_handler_registered;
-
-static inline void sysrq_register_handler(void)
-{
- int error;
-
- error = input_register_handler(&sysrq_handler);
- if (error)
- pr_err("Failed to register input handler, error %d", error);
- else
- sysrq_handler_registered = true;
-}
-
-static inline void sysrq_unregister_handler(void)
-{
- if (sysrq_handler_registered) {
- input_unregister_handler(&sysrq_handler);
- sysrq_handler_registered = false;
- }
-}
-
-#else
-
-static inline void sysrq_register_handler(void)
-{
-}
-
-static inline void sysrq_unregister_handler(void)
-{
-}
-
-#endif /* CONFIG_INPUT */
-
-int sysrq_toggle_support(int enable_mask)
-{
- bool was_enabled = sysrq_on();
-
- sysrq_enabled = enable_mask;
-
- if (was_enabled != sysrq_on()) {
- if (sysrq_on())
- sysrq_register_handler();
- else
- sysrq_unregister_handler();
- }
-
- return 0;
-}
-
-static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
- struct sysrq_key_op *remove_op_p)
-{
- int retval;
- unsigned long flags;
-
- spin_lock_irqsave(&sysrq_key_table_lock, flags);
- if (__sysrq_get_key_op(key) == remove_op_p) {
- __sysrq_put_key_op(key, insert_op_p);
- retval = 0;
- } else {
- retval = -1;
- }
- spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
- return retval;
-}
-
-int register_sysrq_key(int key, struct sysrq_key_op *op_p)
-{
- return __sysrq_swap_key_ops(key, op_p, NULL);
-}
-EXPORT_SYMBOL(register_sysrq_key);
-
-int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
-{
- return __sysrq_swap_key_ops(key, NULL, op_p);
-}
-EXPORT_SYMBOL(unregister_sysrq_key);
-
-#ifdef CONFIG_PROC_FS
-/*
- * writing 'C' to /proc/sysrq-trigger is like sysrq-C
- */
-static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
-{
- if (count) {
- char c;
-
- if (get_user(c, buf))
- return -EFAULT;
- __handle_sysrq(c, false);
- }
-
- return count;
-}
-
-static const struct file_operations proc_sysrq_trigger_operations = {
- .write = write_sysrq_trigger,
- .llseek = noop_llseek,
-};
-
-static void sysrq_init_procfs(void)
-{
- if (!proc_create("sysrq-trigger", S_IWUSR, NULL,
- &proc_sysrq_trigger_operations))
- pr_err("Failed to register proc interface\n");
-}
-
-#else
-
-static inline void sysrq_init_procfs(void)
-{
-}
-
-#endif /* CONFIG_PROC_FS */
-
-static int __init sysrq_init(void)
-{
- sysrq_init_procfs();
-
- if (sysrq_on())
- sysrq_register_handler();
-
- return 0;
-}
-module_init(sysrq_init);
+++ /dev/null
-/*
- * Creating audit events from TTY input.
- *
- * Copyright (C) 2007 Red Hat, Inc. All rights reserved. This copyrighted
- * material is made available to anyone wishing to use, modify, copy, or
- * redistribute it subject to the terms and conditions of the GNU General
- * Public License v.2.
- *
- * Authors: Miloslav Trmac <mitr@redhat.com>
- */
-
-#include <linux/audit.h>
-#include <linux/slab.h>
-#include <linux/tty.h>
-
-struct tty_audit_buf {
- atomic_t count;
- struct mutex mutex; /* Protects all data below */
- int major, minor; /* The TTY which the data is from */
- unsigned icanon:1;
- size_t valid;
- unsigned char *data; /* Allocated size N_TTY_BUF_SIZE */
-};
-
-static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor,
- int icanon)
-{
- struct tty_audit_buf *buf;
-
- buf = kmalloc(sizeof(*buf), GFP_KERNEL);
- if (!buf)
- goto err;
- buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
- if (!buf->data)
- goto err_buf;
- atomic_set(&buf->count, 1);
- mutex_init(&buf->mutex);
- buf->major = major;
- buf->minor = minor;
- buf->icanon = icanon;
- buf->valid = 0;
- return buf;
-
-err_buf:
- kfree(buf);
-err:
- return NULL;
-}
-
-static void tty_audit_buf_free(struct tty_audit_buf *buf)
-{
- WARN_ON(buf->valid != 0);
- kfree(buf->data);
- kfree(buf);
-}
-
-static void tty_audit_buf_put(struct tty_audit_buf *buf)
-{
- if (atomic_dec_and_test(&buf->count))
- tty_audit_buf_free(buf);
-}
-
-static void tty_audit_log(const char *description, struct task_struct *tsk,
- uid_t loginuid, unsigned sessionid, int major,
- int minor, unsigned char *data, size_t size)
-{
- struct audit_buffer *ab;
-
- ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_TTY);
- if (ab) {
- char name[sizeof(tsk->comm)];
- uid_t uid = task_uid(tsk);
-
- audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u "
- "major=%d minor=%d comm=", description,
- tsk->pid, uid, loginuid, sessionid,
- major, minor);
- get_task_comm(name, tsk);
- audit_log_untrustedstring(ab, name);
- audit_log_format(ab, " data=");
- audit_log_n_hex(ab, data, size);
- audit_log_end(ab);
- }
-}
-
-/**
- * tty_audit_buf_push - Push buffered data out
- *
- * Generate an audit message from the contents of @buf, which is owned by
- * @tsk with @loginuid. @buf->mutex must be locked.
- */
-static void tty_audit_buf_push(struct task_struct *tsk, uid_t loginuid,
- unsigned int sessionid,
- struct tty_audit_buf *buf)
-{
- if (buf->valid == 0)
- return;
- if (audit_enabled == 0)
- return;
- tty_audit_log("tty", tsk, loginuid, sessionid, buf->major, buf->minor,
- buf->data, buf->valid);
- buf->valid = 0;
-}
-
-/**
- * tty_audit_buf_push_current - Push buffered data out
- *
- * Generate an audit message from the contents of @buf, which is owned by
- * the current task. @buf->mutex must be locked.
- */
-static void tty_audit_buf_push_current(struct tty_audit_buf *buf)
-{
- uid_t auid = audit_get_loginuid(current);
- unsigned int sessionid = audit_get_sessionid(current);
- tty_audit_buf_push(current, auid, sessionid, buf);
-}
-
-/**
- * tty_audit_exit - Handle a task exit
- *
- * Make sure all buffered data is written out and deallocate the buffer.
- * Only needs to be called if current->signal->tty_audit_buf != %NULL.
- */
-void tty_audit_exit(void)
-{
- struct tty_audit_buf *buf;
-
- spin_lock_irq(¤t->sighand->siglock);
- buf = current->signal->tty_audit_buf;
- current->signal->tty_audit_buf = NULL;
- spin_unlock_irq(¤t->sighand->siglock);
- if (!buf)
- return;
-
- mutex_lock(&buf->mutex);
- tty_audit_buf_push_current(buf);
- mutex_unlock(&buf->mutex);
-
- tty_audit_buf_put(buf);
-}
-
-/**
- * tty_audit_fork - Copy TTY audit state for a new task
- *
- * Set up TTY audit state in @sig from current. @sig needs no locking.
- */
-void tty_audit_fork(struct signal_struct *sig)
-{
- spin_lock_irq(¤t->sighand->siglock);
- sig->audit_tty = current->signal->audit_tty;
- spin_unlock_irq(¤t->sighand->siglock);
-}
-
-/**
- * tty_audit_tiocsti - Log TIOCSTI
- */
-void tty_audit_tiocsti(struct tty_struct *tty, char ch)
-{
- struct tty_audit_buf *buf;
- int major, minor, should_audit;
-
- spin_lock_irq(¤t->sighand->siglock);
- should_audit = current->signal->audit_tty;
- buf = current->signal->tty_audit_buf;
- if (buf)
- atomic_inc(&buf->count);
- spin_unlock_irq(¤t->sighand->siglock);
-
- major = tty->driver->major;
- minor = tty->driver->minor_start + tty->index;
- if (buf) {
- mutex_lock(&buf->mutex);
- if (buf->major == major && buf->minor == minor)
- tty_audit_buf_push_current(buf);
- mutex_unlock(&buf->mutex);
- tty_audit_buf_put(buf);
- }
-
- if (should_audit && audit_enabled) {
- uid_t auid;
- unsigned int sessionid;
-
- auid = audit_get_loginuid(current);
- sessionid = audit_get_sessionid(current);
- tty_audit_log("ioctl=TIOCSTI", current, auid, sessionid, major,
- minor, &ch, 1);
- }
-}
-
-/**
- * tty_audit_push_task - Flush task's pending audit data
- * @tsk: task pointer
- * @loginuid: sender login uid
- * @sessionid: sender session id
- *
- * Called with a ref on @tsk held. Try to lock sighand and get a
- * reference to the tty audit buffer if available.
- * Flush the buffer or return an appropriate error code.
- */
-int tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
-{
- struct tty_audit_buf *buf = ERR_PTR(-EPERM);
- unsigned long flags;
-
- if (!lock_task_sighand(tsk, &flags))
- return -ESRCH;
-
- if (tsk->signal->audit_tty) {
- buf = tsk->signal->tty_audit_buf;
- if (buf)
- atomic_inc(&buf->count);
- }
- unlock_task_sighand(tsk, &flags);
-
- /*
- * Return 0 when signal->audit_tty set
- * but tsk->signal->tty_audit_buf == NULL.
- */
- if (!buf || IS_ERR(buf))
- return PTR_ERR(buf);
-
- mutex_lock(&buf->mutex);
- tty_audit_buf_push(tsk, loginuid, sessionid, buf);
- mutex_unlock(&buf->mutex);
-
- tty_audit_buf_put(buf);
- return 0;
-}
-
-/**
- * tty_audit_buf_get - Get an audit buffer.
- *
- * Get an audit buffer for @tty, allocate it if necessary. Return %NULL
- * if TTY auditing is disabled or out of memory. Otherwise, return a new
- * reference to the buffer.
- */
-static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty)
-{
- struct tty_audit_buf *buf, *buf2;
-
- buf = NULL;
- buf2 = NULL;
- spin_lock_irq(¤t->sighand->siglock);
- if (likely(!current->signal->audit_tty))
- goto out;
- buf = current->signal->tty_audit_buf;
- if (buf) {
- atomic_inc(&buf->count);
- goto out;
- }
- spin_unlock_irq(¤t->sighand->siglock);
-
- buf2 = tty_audit_buf_alloc(tty->driver->major,
- tty->driver->minor_start + tty->index,
- tty->icanon);
- if (buf2 == NULL) {
- audit_log_lost("out of memory in TTY auditing");
- return NULL;
- }
-
- spin_lock_irq(¤t->sighand->siglock);
- if (!current->signal->audit_tty)
- goto out;
- buf = current->signal->tty_audit_buf;
- if (!buf) {
- current->signal->tty_audit_buf = buf2;
- buf = buf2;
- buf2 = NULL;
- }
- atomic_inc(&buf->count);
- /* Fall through */
- out:
- spin_unlock_irq(¤t->sighand->siglock);
- if (buf2)
- tty_audit_buf_free(buf2);
- return buf;
-}
-
-/**
- * tty_audit_add_data - Add data for TTY auditing.
- *
- * Audit @data of @size from @tty, if necessary.
- */
-void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
- size_t size)
-{
- struct tty_audit_buf *buf;
- int major, minor;
-
- if (unlikely(size == 0))
- return;
-
- if (tty->driver->type == TTY_DRIVER_TYPE_PTY
- && tty->driver->subtype == PTY_TYPE_MASTER)
- return;
-
- buf = tty_audit_buf_get(tty);
- if (!buf)
- return;
-
- mutex_lock(&buf->mutex);
- major = tty->driver->major;
- minor = tty->driver->minor_start + tty->index;
- if (buf->major != major || buf->minor != minor
- || buf->icanon != tty->icanon) {
- tty_audit_buf_push_current(buf);
- buf->major = major;
- buf->minor = minor;
- buf->icanon = tty->icanon;
- }
- do {
- size_t run;
-
- run = N_TTY_BUF_SIZE - buf->valid;
- if (run > size)
- run = size;
- memcpy(buf->data + buf->valid, data, run);
- buf->valid += run;
- data += run;
- size -= run;
- if (buf->valid == N_TTY_BUF_SIZE)
- tty_audit_buf_push_current(buf);
- } while (size != 0);
- mutex_unlock(&buf->mutex);
- tty_audit_buf_put(buf);
-}
-
-/**
- * tty_audit_push - Push buffered data out
- *
- * Make sure no audit data is pending for @tty on the current process.
- */
-void tty_audit_push(struct tty_struct *tty)
-{
- struct tty_audit_buf *buf;
-
- spin_lock_irq(¤t->sighand->siglock);
- if (likely(!current->signal->audit_tty)) {
- spin_unlock_irq(¤t->sighand->siglock);
- return;
- }
- buf = current->signal->tty_audit_buf;
- if (buf)
- atomic_inc(&buf->count);
- spin_unlock_irq(¤t->sighand->siglock);
-
- if (buf) {
- int major, minor;
-
- major = tty->driver->major;
- minor = tty->driver->minor_start + tty->index;
- mutex_lock(&buf->mutex);
- if (buf->major == major && buf->minor == minor)
- tty_audit_buf_push_current(buf);
- mutex_unlock(&buf->mutex);
- tty_audit_buf_put(buf);
- }
-}
+++ /dev/null
-/*
- * Tty buffer allocation management
- */
-
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/tty.h>
-#include <linux/tty_driver.h>
-#include <linux/tty_flip.h>
-#include <linux/timer.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/wait.h>
-#include <linux/bitops.h>
-#include <linux/delay.h>
-#include <linux/module.h>
-
-/**
- * tty_buffer_free_all - free buffers used by a tty
- * @tty: tty to free from
- *
- * Remove all the buffers pending on a tty whether queued with data
- * or in the free ring. Must be called when the tty is no longer in use
- *
- * Locking: none
- */
-
-void tty_buffer_free_all(struct tty_struct *tty)
-{
- struct tty_buffer *thead;
- while ((thead = tty->buf.head) != NULL) {
- tty->buf.head = thead->next;
- kfree(thead);
- }
- while ((thead = tty->buf.free) != NULL) {
- tty->buf.free = thead->next;
- kfree(thead);
- }
- tty->buf.tail = NULL;
- tty->buf.memory_used = 0;
-}
-
-/**
- * tty_buffer_alloc - allocate a tty buffer
- * @tty: tty device
- * @size: desired size (characters)
- *
- * Allocate a new tty buffer to hold the desired number of characters.
- * Return NULL if out of memory or the allocation would exceed the
- * per device queue
- *
- * Locking: Caller must hold tty->buf.lock
- */
-
-static struct tty_buffer *tty_buffer_alloc(struct tty_struct *tty, size_t size)
-{
- struct tty_buffer *p;
-
- if (tty->buf.memory_used + size > 65536)
- return NULL;
- p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC);
- if (p == NULL)
- return NULL;
- p->used = 0;
- p->size = size;
- p->next = NULL;
- p->commit = 0;
- p->read = 0;
- p->char_buf_ptr = (char *)(p->data);
- p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size;
- tty->buf.memory_used += size;
- return p;
-}
-
-/**
- * tty_buffer_free - free a tty buffer
- * @tty: tty owning the buffer
- * @b: the buffer to free
- *
- * Free a tty buffer, or add it to the free list according to our
- * internal strategy
- *
- * Locking: Caller must hold tty->buf.lock
- */
-
-static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
-{
- /* Dumb strategy for now - should keep some stats */
- tty->buf.memory_used -= b->size;
- WARN_ON(tty->buf.memory_used < 0);
-
- if (b->size >= 512)
- kfree(b);
- else {
- b->next = tty->buf.free;
- tty->buf.free = b;
- }
-}
-
-/**
- * __tty_buffer_flush - flush full tty buffers
- * @tty: tty to flush
- *
- * flush all the buffers containing receive data. Caller must
- * hold the buffer lock and must have ensured no parallel flush to
- * ldisc is running.
- *
- * Locking: Caller must hold tty->buf.lock
- */
-
-static void __tty_buffer_flush(struct tty_struct *tty)
-{
- struct tty_buffer *thead;
-
- while ((thead = tty->buf.head) != NULL) {
- tty->buf.head = thead->next;
- tty_buffer_free(tty, thead);
- }
- tty->buf.tail = NULL;
-}
-
-/**
- * tty_buffer_flush - flush full tty buffers
- * @tty: tty to flush
- *
- * flush all the buffers containing receive data. If the buffer is
- * being processed by flush_to_ldisc then we defer the processing
- * to that function
- *
- * Locking: none
- */
-
-void tty_buffer_flush(struct tty_struct *tty)
-{
- unsigned long flags;
- spin_lock_irqsave(&tty->buf.lock, flags);
-
- /* If the data is being pushed to the tty layer then we can't
- process it here. Instead set a flag and the flush_to_ldisc
- path will process the flush request before it exits */
- if (test_bit(TTY_FLUSHING, &tty->flags)) {
- set_bit(TTY_FLUSHPENDING, &tty->flags);
- spin_unlock_irqrestore(&tty->buf.lock, flags);
- wait_event(tty->read_wait,
- test_bit(TTY_FLUSHPENDING, &tty->flags) == 0);
- return;
- } else
- __tty_buffer_flush(tty);
- spin_unlock_irqrestore(&tty->buf.lock, flags);
-}
-
-/**
- * tty_buffer_find - find a free tty buffer
- * @tty: tty owning the buffer
- * @size: characters wanted
- *
- * Locate an existing suitable tty buffer or if we are lacking one then
- * allocate a new one. We round our buffers off in 256 character chunks
- * to get better allocation behaviour.
- *
- * Locking: Caller must hold tty->buf.lock
- */
-
-static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
-{
- struct tty_buffer **tbh = &tty->buf.free;
- while ((*tbh) != NULL) {
- struct tty_buffer *t = *tbh;
- if (t->size >= size) {
- *tbh = t->next;
- t->next = NULL;
- t->used = 0;
- t->commit = 0;
- t->read = 0;
- tty->buf.memory_used += t->size;
- return t;
- }
- tbh = &((*tbh)->next);
- }
- /* Round the buffer size out */
- size = (size + 0xFF) & ~0xFF;
- return tty_buffer_alloc(tty, size);
- /* Should possibly check if this fails for the largest buffer we
- have queued and recycle that ? */
-}
-
-/**
- * tty_buffer_request_room - grow tty buffer if needed
- * @tty: tty structure
- * @size: size desired
- *
- * Make at least size bytes of linear space available for the tty
- * buffer. If we fail return the size we managed to find.
- *
- * Locking: Takes tty->buf.lock
- */
-int tty_buffer_request_room(struct tty_struct *tty, size_t size)
-{
- struct tty_buffer *b, *n;
- int left;
- unsigned long flags;
-
- spin_lock_irqsave(&tty->buf.lock, flags);
-
- /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
- remove this conditional if its worth it. This would be invisible
- to the callers */
- if ((b = tty->buf.tail) != NULL)
- left = b->size - b->used;
- else
- left = 0;
-
- if (left < size) {
- /* This is the slow path - looking for new buffers to use */
- if ((n = tty_buffer_find(tty, size)) != NULL) {
- if (b != NULL) {
- b->next = n;
- b->commit = b->used;
- } else
- tty->buf.head = n;
- tty->buf.tail = n;
- } else
- size = left;
- }
-
- spin_unlock_irqrestore(&tty->buf.lock, flags);
- return size;
-}
-EXPORT_SYMBOL_GPL(tty_buffer_request_room);
-
-/**
- * tty_insert_flip_string_fixed_flag - Add characters to the tty buffer
- * @tty: tty structure
- * @chars: characters
- * @flag: flag value for each character
- * @size: size
- *
- * Queue a series of bytes to the tty buffering. All the characters
- * passed are marked with the supplied flag. Returns the number added.
- *
- * Locking: Called functions may take tty->buf.lock
- */
-
-int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
- const unsigned char *chars, char flag, size_t size)
-{
- int copied = 0;
- do {
- int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
- int space = tty_buffer_request_room(tty, goal);
- struct tty_buffer *tb = tty->buf.tail;
- /* If there is no space then tb may be NULL */
- if (unlikely(space == 0))
- break;
- memcpy(tb->char_buf_ptr + tb->used, chars, space);
- memset(tb->flag_buf_ptr + tb->used, flag, space);
- tb->used += space;
- copied += space;
- chars += space;
- /* There is a small chance that we need to split the data over
- several buffers. If this is the case we must loop */
- } while (unlikely(size > copied));
- return copied;
-}
-EXPORT_SYMBOL(tty_insert_flip_string_fixed_flag);
-
-/**
- * tty_insert_flip_string_flags - Add characters to the tty buffer
- * @tty: tty structure
- * @chars: characters
- * @flags: flag bytes
- * @size: size
- *
- * Queue a series of bytes to the tty buffering. For each character
- * the flags array indicates the status of the character. Returns the
- * number added.
- *
- * Locking: Called functions may take tty->buf.lock
- */
-
-int tty_insert_flip_string_flags(struct tty_struct *tty,
- const unsigned char *chars, const char *flags, size_t size)
-{
- int copied = 0;
- do {
- int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
- int space = tty_buffer_request_room(tty, goal);
- struct tty_buffer *tb = tty->buf.tail;
- /* If there is no space then tb may be NULL */
- if (unlikely(space == 0))
- break;
- memcpy(tb->char_buf_ptr + tb->used, chars, space);
- memcpy(tb->flag_buf_ptr + tb->used, flags, space);
- tb->used += space;
- copied += space;
- chars += space;
- flags += space;
- /* There is a small chance that we need to split the data over
- several buffers. If this is the case we must loop */
- } while (unlikely(size > copied));
- return copied;
-}
-EXPORT_SYMBOL(tty_insert_flip_string_flags);
-
-/**
- * tty_schedule_flip - push characters to ldisc
- * @tty: tty to push from
- *
- * Takes any pending buffers and transfers their ownership to the
- * ldisc side of the queue. It then schedules those characters for
- * processing by the line discipline.
- *
- * Locking: Takes tty->buf.lock
- */
-
-void tty_schedule_flip(struct tty_struct *tty)
-{
- unsigned long flags;
- spin_lock_irqsave(&tty->buf.lock, flags);
- if (tty->buf.tail != NULL)
- tty->buf.tail->commit = tty->buf.tail->used;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
- schedule_delayed_work(&tty->buf.work, 1);
-}
-EXPORT_SYMBOL(tty_schedule_flip);
-
-/**
- * tty_prepare_flip_string - make room for characters
- * @tty: tty
- * @chars: return pointer for character write area
- * @size: desired size
- *
- * Prepare a block of space in the buffer for data. Returns the length
- * available and buffer pointer to the space which is now allocated and
- * accounted for as ready for normal characters. This is used for drivers
- * that need their own block copy routines into the buffer. There is no
- * guarantee the buffer is a DMA target!
- *
- * Locking: May call functions taking tty->buf.lock
- */
-
-int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
- size_t size)
-{
- int space = tty_buffer_request_room(tty, size);
- if (likely(space)) {
- struct tty_buffer *tb = tty->buf.tail;
- *chars = tb->char_buf_ptr + tb->used;
- memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
- tb->used += space;
- }
- return space;
-}
-EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
-
-/**
- * tty_prepare_flip_string_flags - make room for characters
- * @tty: tty
- * @chars: return pointer for character write area
- * @flags: return pointer for status flag write area
- * @size: desired size
- *
- * Prepare a block of space in the buffer for data. Returns the length
- * available and buffer pointer to the space which is now allocated and
- * accounted for as ready for characters. This is used for drivers
- * that need their own block copy routines into the buffer. There is no
- * guarantee the buffer is a DMA target!
- *
- * Locking: May call functions taking tty->buf.lock
- */
-
-int tty_prepare_flip_string_flags(struct tty_struct *tty,
- unsigned char **chars, char **flags, size_t size)
-{
- int space = tty_buffer_request_room(tty, size);
- if (likely(space)) {
- struct tty_buffer *tb = tty->buf.tail;
- *chars = tb->char_buf_ptr + tb->used;
- *flags = tb->flag_buf_ptr + tb->used;
- tb->used += space;
- }
- return space;
-}
-EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
-
-
-
-/**
- * flush_to_ldisc
- * @work: tty structure passed from work queue.
- *
- * This routine is called out of the software interrupt to flush data
- * from the buffer chain to the line discipline.
- *
- * Locking: holds tty->buf.lock to guard buffer list. Drops the lock
- * while invoking the line discipline receive_buf method. The
- * receive_buf method is single threaded for each tty instance.
- */
-
-static void flush_to_ldisc(struct work_struct *work)
-{
- struct tty_struct *tty =
- container_of(work, struct tty_struct, buf.work.work);
- unsigned long flags;
- struct tty_ldisc *disc;
-
- disc = tty_ldisc_ref(tty);
- if (disc == NULL) /* !TTY_LDISC */
- return;
-
- spin_lock_irqsave(&tty->buf.lock, flags);
-
- if (!test_and_set_bit(TTY_FLUSHING, &tty->flags)) {
- struct tty_buffer *head;
- while ((head = tty->buf.head) != NULL) {
- int count;
- char *char_buf;
- unsigned char *flag_buf;
-
- count = head->commit - head->read;
- if (!count) {
- if (head->next == NULL)
- break;
- tty->buf.head = head->next;
- tty_buffer_free(tty, head);
- continue;
- }
- /* Ldisc or user is trying to flush the buffers
- we are feeding to the ldisc, stop feeding the
- line discipline as we want to empty the queue */
- if (test_bit(TTY_FLUSHPENDING, &tty->flags))
- break;
- if (!tty->receive_room) {
- schedule_delayed_work(&tty->buf.work, 1);
- break;
- }
- if (count > tty->receive_room)
- count = tty->receive_room;
- char_buf = head->char_buf_ptr + head->read;
- flag_buf = head->flag_buf_ptr + head->read;
- head->read += count;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
- disc->ops->receive_buf(tty, char_buf,
- flag_buf, count);
- spin_lock_irqsave(&tty->buf.lock, flags);
- }
- clear_bit(TTY_FLUSHING, &tty->flags);
- }
-
- /* We may have a deferred request to flush the input buffer,
- if so pull the chain under the lock and empty the queue */
- if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
- __tty_buffer_flush(tty);
- clear_bit(TTY_FLUSHPENDING, &tty->flags);
- wake_up(&tty->read_wait);
- }
- spin_unlock_irqrestore(&tty->buf.lock, flags);
-
- tty_ldisc_deref(disc);
-}
-
-/**
- * tty_flush_to_ldisc
- * @tty: tty to push
- *
- * Push the terminal flip buffers to the line discipline.
- *
- * Must not be called from IRQ context.
- */
-void tty_flush_to_ldisc(struct tty_struct *tty)
-{
- flush_delayed_work(&tty->buf.work);
-}
-
-/**
- * tty_flip_buffer_push - terminal
- * @tty: tty to push
- *
- * Queue a push of the terminal flip buffers to the line discipline. This
- * function must not be called from IRQ context if tty->low_latency is set.
- *
- * In the event of the queue being busy for flipping the work will be
- * held off and retried later.
- *
- * Locking: tty buffer lock. Driver locks in low latency mode.
- */
-
-void tty_flip_buffer_push(struct tty_struct *tty)
-{
- unsigned long flags;
- spin_lock_irqsave(&tty->buf.lock, flags);
- if (tty->buf.tail != NULL)
- tty->buf.tail->commit = tty->buf.tail->used;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
-
- if (tty->low_latency)
- flush_to_ldisc(&tty->buf.work.work);
- else
- schedule_delayed_work(&tty->buf.work, 1);
-}
-EXPORT_SYMBOL(tty_flip_buffer_push);
-
-/**
- * tty_buffer_init - prepare a tty buffer structure
- * @tty: tty to initialise
- *
- * Set up the initial state of the buffer management for a tty device.
- * Must be called before the other tty buffer functions are used.
- *
- * Locking: none
- */
-
-void tty_buffer_init(struct tty_struct *tty)
-{
- spin_lock_init(&tty->buf.lock);
- tty->buf.head = NULL;
- tty->buf.tail = NULL;
- tty->buf.free = NULL;
- tty->buf.memory_used = 0;
- INIT_DELAYED_WORK(&tty->buf.work, flush_to_ldisc);
-}
-
+++ /dev/null
-/*
- * linux/drivers/char/tty_io.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- */
-
-/*
- * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
- * or rs-channels. It also implements echoing, cooked mode etc.
- *
- * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
- *
- * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
- * tty_struct and tty_queue structures. Previously there was an array
- * of 256 tty_struct's which was statically allocated, and the
- * tty_queue structures were allocated at boot time. Both are now
- * dynamically allocated only when the tty is open.
- *
- * Also restructured routines so that there is more of a separation
- * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
- * the low-level tty routines (serial.c, pty.c, console.c). This
- * makes for cleaner and more compact code. -TYT, 9/17/92
- *
- * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
- * which can be dynamically activated and de-activated by the line
- * discipline handling modules (like SLIP).
- *
- * NOTE: pay no attention to the line discipline code (yet); its
- * interface is still subject to change in this version...
- * -- TYT, 1/31/92
- *
- * Added functionality to the OPOST tty handling. No delays, but all
- * other bits should be there.
- * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
- *
- * Rewrote canonical mode and added more termios flags.
- * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
- *
- * Reorganized FASYNC support so mouse code can share it.
- * -- ctm@ardi.com, 9Sep95
- *
- * New TIOCLINUX variants added.
- * -- mj@k332.feld.cvut.cz, 19-Nov-95
- *
- * Restrict vt switching via ioctl()
- * -- grif@cs.ucr.edu, 5-Dec-95
- *
- * Move console and virtual terminal code to more appropriate files,
- * implement CONFIG_VT and generalize console device interface.
- * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
- *
- * Rewrote tty_init_dev and tty_release_dev to eliminate races.
- * -- Bill Hawes <whawes@star.net>, June 97
- *
- * Added devfs support.
- * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
- *
- * Added support for a Unix98-style ptmx device.
- * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
- *
- * Reduced memory usage for older ARM systems
- * -- Russell King <rmk@arm.linux.org.uk>
- *
- * Move do_SAK() into process context. Less stack use in devfs functions.
- * alloc_tty_struct() always uses kmalloc()
- * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
- */
-
-#include <linux/types.h>
-#include <linux/major.h>
-#include <linux/errno.h>
-#include <linux/signal.h>
-#include <linux/fcntl.h>
-#include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/tty.h>
-#include <linux/tty_driver.h>
-#include <linux/tty_flip.h>
-#include <linux/devpts_fs.h>
-#include <linux/file.h>
-#include <linux/fdtable.h>
-#include <linux/console.h>
-#include <linux/timer.h>
-#include <linux/ctype.h>
-#include <linux/kd.h>
-#include <linux/mm.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/poll.h>
-#include <linux/proc_fs.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/smp_lock.h>
-#include <linux/device.h>
-#include <linux/wait.h>
-#include <linux/bitops.h>
-#include <linux/delay.h>
-#include <linux/seq_file.h>
-#include <linux/serial.h>
-
-#include <linux/uaccess.h>
-#include <asm/system.h>
-
-#include <linux/kbd_kern.h>
-#include <linux/vt_kern.h>
-#include <linux/selection.h>
-
-#include <linux/kmod.h>
-#include <linux/nsproxy.h>
-
-#undef TTY_DEBUG_HANGUP
-
-#define TTY_PARANOIA_CHECK 1
-#define CHECK_TTY_COUNT 1
-
-struct ktermios tty_std_termios = { /* for the benefit of tty drivers */
- .c_iflag = ICRNL | IXON,
- .c_oflag = OPOST | ONLCR,
- .c_cflag = B38400 | CS8 | CREAD | HUPCL,
- .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
- ECHOCTL | ECHOKE | IEXTEN,
- .c_cc = INIT_C_CC,
- .c_ispeed = 38400,
- .c_ospeed = 38400
-};
-
-EXPORT_SYMBOL(tty_std_termios);
-
-/* This list gets poked at by procfs and various bits of boot up code. This
- could do with some rationalisation such as pulling the tty proc function
- into this file */
-
-LIST_HEAD(tty_drivers); /* linked list of tty drivers */
-
-/* Mutex to protect creating and releasing a tty. This is shared with
- vt.c for deeply disgusting hack reasons */
-DEFINE_MUTEX(tty_mutex);
-EXPORT_SYMBOL(tty_mutex);
-
-/* Spinlock to protect the tty->tty_files list */
-DEFINE_SPINLOCK(tty_files_lock);
-
-static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
-static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
-ssize_t redirected_tty_write(struct file *, const char __user *,
- size_t, loff_t *);
-static unsigned int tty_poll(struct file *, poll_table *);
-static int tty_open(struct inode *, struct file *);
-long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
-#ifdef CONFIG_COMPAT
-static long tty_compat_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg);
-#else
-#define tty_compat_ioctl NULL
-#endif
-static int __tty_fasync(int fd, struct file *filp, int on);
-static int tty_fasync(int fd, struct file *filp, int on);
-static void release_tty(struct tty_struct *tty, int idx);
-static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
-static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
-
-/**
- * alloc_tty_struct - allocate a tty object
- *
- * Return a new empty tty structure. The data fields have not
- * been initialized in any way but has been zeroed
- *
- * Locking: none
- */
-
-struct tty_struct *alloc_tty_struct(void)
-{
- return kzalloc(sizeof(struct tty_struct), GFP_KERNEL);
-}
-
-/**
- * free_tty_struct - free a disused tty
- * @tty: tty struct to free
- *
- * Free the write buffers, tty queue and tty memory itself.
- *
- * Locking: none. Must be called after tty is definitely unused
- */
-
-void free_tty_struct(struct tty_struct *tty)
-{
- if (tty->dev)
- put_device(tty->dev);
- kfree(tty->write_buf);
- tty_buffer_free_all(tty);
- kfree(tty);
-}
-
-static inline struct tty_struct *file_tty(struct file *file)
-{
- return ((struct tty_file_private *)file->private_data)->tty;
-}
-
-/* Associate a new file with the tty structure */
-int tty_add_file(struct tty_struct *tty, struct file *file)
-{
- struct tty_file_private *priv;
-
- priv = kmalloc(sizeof(*priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
-
- priv->tty = tty;
- priv->file = file;
- file->private_data = priv;
-
- spin_lock(&tty_files_lock);
- list_add(&priv->list, &tty->tty_files);
- spin_unlock(&tty_files_lock);
-
- return 0;
-}
-
-/* Delete file from its tty */
-void tty_del_file(struct file *file)
-{
- struct tty_file_private *priv = file->private_data;
-
- spin_lock(&tty_files_lock);
- list_del(&priv->list);
- spin_unlock(&tty_files_lock);
- file->private_data = NULL;
- kfree(priv);
-}
-
-
-#define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
-
-/**
- * tty_name - return tty naming
- * @tty: tty structure
- * @buf: buffer for output
- *
- * Convert a tty structure into a name. The name reflects the kernel
- * naming policy and if udev is in use may not reflect user space
- *
- * Locking: none
- */
-
-char *tty_name(struct tty_struct *tty, char *buf)
-{
- if (!tty) /* Hmm. NULL pointer. That's fun. */
- strcpy(buf, "NULL tty");
- else
- strcpy(buf, tty->name);
- return buf;
-}
-
-EXPORT_SYMBOL(tty_name);
-
-int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
- const char *routine)
-{
-#ifdef TTY_PARANOIA_CHECK
- if (!tty) {
- printk(KERN_WARNING
- "null TTY for (%d:%d) in %s\n",
- imajor(inode), iminor(inode), routine);
- return 1;
- }
- if (tty->magic != TTY_MAGIC) {
- printk(KERN_WARNING
- "bad magic number for tty struct (%d:%d) in %s\n",
- imajor(inode), iminor(inode), routine);
- return 1;
- }
-#endif
- return 0;
-}
-
-static int check_tty_count(struct tty_struct *tty, const char *routine)
-{
-#ifdef CHECK_TTY_COUNT
- struct list_head *p;
- int count = 0;
-
- spin_lock(&tty_files_lock);
- list_for_each(p, &tty->tty_files) {
- count++;
- }
- spin_unlock(&tty_files_lock);
- if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
- tty->driver->subtype == PTY_TYPE_SLAVE &&
- tty->link && tty->link->count)
- count++;
- if (tty->count != count) {
- printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) "
- "!= #fd's(%d) in %s\n",
- tty->name, tty->count, count, routine);
- return count;
- }
-#endif
- return 0;
-}
-
-/**
- * get_tty_driver - find device of a tty
- * @dev_t: device identifier
- * @index: returns the index of the tty
- *
- * This routine returns a tty driver structure, given a device number
- * and also passes back the index number.
- *
- * Locking: caller must hold tty_mutex
- */
-
-static struct tty_driver *get_tty_driver(dev_t device, int *index)
-{
- struct tty_driver *p;
-
- list_for_each_entry(p, &tty_drivers, tty_drivers) {
- dev_t base = MKDEV(p->major, p->minor_start);
- if (device < base || device >= base + p->num)
- continue;
- *index = device - base;
- return tty_driver_kref_get(p);
- }
- return NULL;
-}
-
-#ifdef CONFIG_CONSOLE_POLL
-
-/**
- * tty_find_polling_driver - find device of a polled tty
- * @name: name string to match
- * @line: pointer to resulting tty line nr
- *
- * This routine returns a tty driver structure, given a name
- * and the condition that the tty driver is capable of polled
- * operation.
- */
-struct tty_driver *tty_find_polling_driver(char *name, int *line)
-{
- struct tty_driver *p, *res = NULL;
- int tty_line = 0;
- int len;
- char *str, *stp;
-
- for (str = name; *str; str++)
- if ((*str >= '0' && *str <= '9') || *str == ',')
- break;
- if (!*str)
- return NULL;
-
- len = str - name;
- tty_line = simple_strtoul(str, &str, 10);
-
- mutex_lock(&tty_mutex);
- /* Search through the tty devices to look for a match */
- list_for_each_entry(p, &tty_drivers, tty_drivers) {
- if (strncmp(name, p->name, len) != 0)
- continue;
- stp = str;
- if (*stp == ',')
- stp++;
- if (*stp == '\0')
- stp = NULL;
-
- if (tty_line >= 0 && tty_line < p->num && p->ops &&
- p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) {
- res = tty_driver_kref_get(p);
- *line = tty_line;
- break;
- }
- }
- mutex_unlock(&tty_mutex);
-
- return res;
-}
-EXPORT_SYMBOL_GPL(tty_find_polling_driver);
-#endif
-
-/**
- * tty_check_change - check for POSIX terminal changes
- * @tty: tty to check
- *
- * If we try to write to, or set the state of, a terminal and we're
- * not in the foreground, send a SIGTTOU. If the signal is blocked or
- * ignored, go ahead and perform the operation. (POSIX 7.2)
- *
- * Locking: ctrl_lock
- */
-
-int tty_check_change(struct tty_struct *tty)
-{
- unsigned long flags;
- int ret = 0;
-
- if (current->signal->tty != tty)
- return 0;
-
- spin_lock_irqsave(&tty->ctrl_lock, flags);
-
- if (!tty->pgrp) {
- printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n");
- goto out_unlock;
- }
- if (task_pgrp(current) == tty->pgrp)
- goto out_unlock;
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- if (is_ignored(SIGTTOU))
- goto out;
- if (is_current_pgrp_orphaned()) {
- ret = -EIO;
- goto out;
- }
- kill_pgrp(task_pgrp(current), SIGTTOU, 1);
- set_thread_flag(TIF_SIGPENDING);
- ret = -ERESTARTSYS;
-out:
- return ret;
-out_unlock:
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- return ret;
-}
-
-EXPORT_SYMBOL(tty_check_change);
-
-static ssize_t hung_up_tty_read(struct file *file, char __user *buf,
- size_t count, loff_t *ppos)
-{
- return 0;
-}
-
-static ssize_t hung_up_tty_write(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
-{
- return -EIO;
-}
-
-/* No kernel lock held - none needed ;) */
-static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait)
-{
- return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;
-}
-
-static long hung_up_tty_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
-}
-
-static long hung_up_tty_compat_ioctl(struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
-}
-
-static const struct file_operations tty_fops = {
- .llseek = no_llseek,
- .read = tty_read,
- .write = tty_write,
- .poll = tty_poll,
- .unlocked_ioctl = tty_ioctl,
- .compat_ioctl = tty_compat_ioctl,
- .open = tty_open,
- .release = tty_release,
- .fasync = tty_fasync,
-};
-
-static const struct file_operations console_fops = {
- .llseek = no_llseek,
- .read = tty_read,
- .write = redirected_tty_write,
- .poll = tty_poll,
- .unlocked_ioctl = tty_ioctl,
- .compat_ioctl = tty_compat_ioctl,
- .open = tty_open,
- .release = tty_release,
- .fasync = tty_fasync,
-};
-
-static const struct file_operations hung_up_tty_fops = {
- .llseek = no_llseek,
- .read = hung_up_tty_read,
- .write = hung_up_tty_write,
- .poll = hung_up_tty_poll,
- .unlocked_ioctl = hung_up_tty_ioctl,
- .compat_ioctl = hung_up_tty_compat_ioctl,
- .release = tty_release,
-};
-
-static DEFINE_SPINLOCK(redirect_lock);
-static struct file *redirect;
-
-/**
- * tty_wakeup - request more data
- * @tty: terminal
- *
- * Internal and external helper for wakeups of tty. This function
- * informs the line discipline if present that the driver is ready
- * to receive more output data.
- */
-
-void tty_wakeup(struct tty_struct *tty)
-{
- struct tty_ldisc *ld;
-
- if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
- ld = tty_ldisc_ref(tty);
- if (ld) {
- if (ld->ops->write_wakeup)
- ld->ops->write_wakeup(tty);
- tty_ldisc_deref(ld);
- }
- }
- wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
-}
-
-EXPORT_SYMBOL_GPL(tty_wakeup);
-
-/**
- * __tty_hangup - actual handler for hangup events
- * @work: tty device
- *
- * This can be called by the "eventd" kernel thread. That is process
- * synchronous but doesn't hold any locks, so we need to make sure we
- * have the appropriate locks for what we're doing.
- *
- * The hangup event clears any pending redirections onto the hung up
- * device. It ensures future writes will error and it does the needed
- * line discipline hangup and signal delivery. The tty object itself
- * remains intact.
- *
- * Locking:
- * BTM
- * redirect lock for undoing redirection
- * file list lock for manipulating list of ttys
- * tty_ldisc_lock from called functions
- * termios_mutex resetting termios data
- * tasklist_lock to walk task list for hangup event
- * ->siglock to protect ->signal/->sighand
- */
-void __tty_hangup(struct tty_struct *tty)
-{
- struct file *cons_filp = NULL;
- struct file *filp, *f = NULL;
- struct task_struct *p;
- struct tty_file_private *priv;
- int closecount = 0, n;
- unsigned long flags;
- int refs = 0;
-
- if (!tty)
- return;
-
-
- spin_lock(&redirect_lock);
- if (redirect && file_tty(redirect) == tty) {
- f = redirect;
- redirect = NULL;
- }
- spin_unlock(&redirect_lock);
-
- tty_lock();
-
- /* inuse_filps is protected by the single tty lock,
- this really needs to change if we want to flush the
- workqueue with the lock held */
- check_tty_count(tty, "tty_hangup");
-
- spin_lock(&tty_files_lock);
- /* This breaks for file handles being sent over AF_UNIX sockets ? */
- list_for_each_entry(priv, &tty->tty_files, list) {
- filp = priv->file;
- if (filp->f_op->write == redirected_tty_write)
- cons_filp = filp;
- if (filp->f_op->write != tty_write)
- continue;
- closecount++;
- __tty_fasync(-1, filp, 0); /* can't block */
- filp->f_op = &hung_up_tty_fops;
- }
- spin_unlock(&tty_files_lock);
-
- tty_ldisc_hangup(tty);
-
- read_lock(&tasklist_lock);
- if (tty->session) {
- do_each_pid_task(tty->session, PIDTYPE_SID, p) {
- spin_lock_irq(&p->sighand->siglock);
- if (p->signal->tty == tty) {
- p->signal->tty = NULL;
- /* We defer the dereferences outside fo
- the tasklist lock */
- refs++;
- }
- if (!p->signal->leader) {
- spin_unlock_irq(&p->sighand->siglock);
- continue;
- }
- __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);
- __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);
- put_pid(p->signal->tty_old_pgrp); /* A noop */
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- if (tty->pgrp)
- p->signal->tty_old_pgrp = get_pid(tty->pgrp);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- spin_unlock_irq(&p->sighand->siglock);
- } while_each_pid_task(tty->session, PIDTYPE_SID, p);
- }
- read_unlock(&tasklist_lock);
-
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- clear_bit(TTY_THROTTLED, &tty->flags);
- clear_bit(TTY_PUSH, &tty->flags);
- clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- put_pid(tty->session);
- put_pid(tty->pgrp);
- tty->session = NULL;
- tty->pgrp = NULL;
- tty->ctrl_status = 0;
- set_bit(TTY_HUPPED, &tty->flags);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-
- /* Account for the p->signal references we killed */
- while (refs--)
- tty_kref_put(tty);
-
- /*
- * If one of the devices matches a console pointer, we
- * cannot just call hangup() because that will cause
- * tty->count and state->count to go out of sync.
- * So we just call close() the right number of times.
- */
- if (cons_filp) {
- if (tty->ops->close)
- for (n = 0; n < closecount; n++)
- tty->ops->close(tty, cons_filp);
- } else if (tty->ops->hangup)
- (tty->ops->hangup)(tty);
- /*
- * We don't want to have driver/ldisc interactions beyond
- * the ones we did here. The driver layer expects no
- * calls after ->hangup() from the ldisc side. However we
- * can't yet guarantee all that.
- */
- set_bit(TTY_HUPPED, &tty->flags);
- tty_ldisc_enable(tty);
-
- tty_unlock();
-
- if (f)
- fput(f);
-}
-
-static void do_tty_hangup(struct work_struct *work)
-{
- struct tty_struct *tty =
- container_of(work, struct tty_struct, hangup_work);
-
- __tty_hangup(tty);
-}
-
-/**
- * tty_hangup - trigger a hangup event
- * @tty: tty to hangup
- *
- * A carrier loss (virtual or otherwise) has occurred on this like
- * schedule a hangup sequence to run after this event.
- */
-
-void tty_hangup(struct tty_struct *tty)
-{
-#ifdef TTY_DEBUG_HANGUP
- char buf[64];
- printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf));
-#endif
- schedule_work(&tty->hangup_work);
-}
-
-EXPORT_SYMBOL(tty_hangup);
-
-/**
- * tty_vhangup - process vhangup
- * @tty: tty to hangup
- *
- * The user has asked via system call for the terminal to be hung up.
- * We do this synchronously so that when the syscall returns the process
- * is complete. That guarantee is necessary for security reasons.
- */
-
-void tty_vhangup(struct tty_struct *tty)
-{
-#ifdef TTY_DEBUG_HANGUP
- char buf[64];
-
- printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf));
-#endif
- __tty_hangup(tty);
-}
-
-EXPORT_SYMBOL(tty_vhangup);
-
-
-/**
- * tty_vhangup_self - process vhangup for own ctty
- *
- * Perform a vhangup on the current controlling tty
- */
-
-void tty_vhangup_self(void)
-{
- struct tty_struct *tty;
-
- tty = get_current_tty();
- if (tty) {
- tty_vhangup(tty);
- tty_kref_put(tty);
- }
-}
-
-/**
- * tty_hung_up_p - was tty hung up
- * @filp: file pointer of tty
- *
- * Return true if the tty has been subject to a vhangup or a carrier
- * loss
- */
-
-int tty_hung_up_p(struct file *filp)
-{
- return (filp->f_op == &hung_up_tty_fops);
-}
-
-EXPORT_SYMBOL(tty_hung_up_p);
-
-static void session_clear_tty(struct pid *session)
-{
- struct task_struct *p;
- do_each_pid_task(session, PIDTYPE_SID, p) {
- proc_clear_tty(p);
- } while_each_pid_task(session, PIDTYPE_SID, p);
-}
-
-/**
- * disassociate_ctty - disconnect controlling tty
- * @on_exit: true if exiting so need to "hang up" the session
- *
- * This function is typically called only by the session leader, when
- * it wants to disassociate itself from its controlling tty.
- *
- * It performs the following functions:
- * (1) Sends a SIGHUP and SIGCONT to the foreground process group
- * (2) Clears the tty from being controlling the session
- * (3) Clears the controlling tty for all processes in the
- * session group.
- *
- * The argument on_exit is set to 1 if called when a process is
- * exiting; it is 0 if called by the ioctl TIOCNOTTY.
- *
- * Locking:
- * BTM is taken for hysterical raisins, and held when
- * called from no_tty().
- * tty_mutex is taken to protect tty
- * ->siglock is taken to protect ->signal/->sighand
- * tasklist_lock is taken to walk process list for sessions
- * ->siglock is taken to protect ->signal/->sighand
- */
-
-void disassociate_ctty(int on_exit)
-{
- struct tty_struct *tty;
- struct pid *tty_pgrp = NULL;
-
- if (!current->signal->leader)
- return;
-
- tty = get_current_tty();
- if (tty) {
- tty_pgrp = get_pid(tty->pgrp);
- if (on_exit) {
- if (tty->driver->type != TTY_DRIVER_TYPE_PTY)
- tty_vhangup(tty);
- }
- tty_kref_put(tty);
- } else if (on_exit) {
- struct pid *old_pgrp;
- spin_lock_irq(¤t->sighand->siglock);
- old_pgrp = current->signal->tty_old_pgrp;
- current->signal->tty_old_pgrp = NULL;
- spin_unlock_irq(¤t->sighand->siglock);
- if (old_pgrp) {
- kill_pgrp(old_pgrp, SIGHUP, on_exit);
- kill_pgrp(old_pgrp, SIGCONT, on_exit);
- put_pid(old_pgrp);
- }
- return;
- }
- if (tty_pgrp) {
- kill_pgrp(tty_pgrp, SIGHUP, on_exit);
- if (!on_exit)
- kill_pgrp(tty_pgrp, SIGCONT, on_exit);
- put_pid(tty_pgrp);
- }
-
- spin_lock_irq(¤t->sighand->siglock);
- put_pid(current->signal->tty_old_pgrp);
- current->signal->tty_old_pgrp = NULL;
- spin_unlock_irq(¤t->sighand->siglock);
-
- tty = get_current_tty();
- if (tty) {
- unsigned long flags;
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- put_pid(tty->session);
- put_pid(tty->pgrp);
- tty->session = NULL;
- tty->pgrp = NULL;
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- tty_kref_put(tty);
- } else {
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "error attempted to write to tty [0x%p]"
- " = NULL", tty);
-#endif
- }
-
- /* Now clear signal->tty under the lock */
- read_lock(&tasklist_lock);
- session_clear_tty(task_session(current));
- read_unlock(&tasklist_lock);
-}
-
-/**
- *
- * no_tty - Ensure the current process does not have a controlling tty
- */
-void no_tty(void)
-{
- struct task_struct *tsk = current;
- tty_lock();
- disassociate_ctty(0);
- tty_unlock();
- proc_clear_tty(tsk);
-}
-
-
-/**
- * stop_tty - propagate flow control
- * @tty: tty to stop
- *
- * Perform flow control to the driver. For PTY/TTY pairs we
- * must also propagate the TIOCKPKT status. May be called
- * on an already stopped device and will not re-call the driver
- * method.
- *
- * This functionality is used by both the line disciplines for
- * halting incoming flow and by the driver. It may therefore be
- * called from any context, may be under the tty atomic_write_lock
- * but not always.
- *
- * Locking:
- * Uses the tty control lock internally
- */
-
-void stop_tty(struct tty_struct *tty)
-{
- unsigned long flags;
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- if (tty->stopped) {
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- return;
- }
- tty->stopped = 1;
- if (tty->link && tty->link->packet) {
- tty->ctrl_status &= ~TIOCPKT_START;
- tty->ctrl_status |= TIOCPKT_STOP;
- wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
- }
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- if (tty->ops->stop)
- (tty->ops->stop)(tty);
-}
-
-EXPORT_SYMBOL(stop_tty);
-
-/**
- * start_tty - propagate flow control
- * @tty: tty to start
- *
- * Start a tty that has been stopped if at all possible. Perform
- * any necessary wakeups and propagate the TIOCPKT status. If this
- * is the tty was previous stopped and is being started then the
- * driver start method is invoked and the line discipline woken.
- *
- * Locking:
- * ctrl_lock
- */
-
-void start_tty(struct tty_struct *tty)
-{
- unsigned long flags;
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- if (!tty->stopped || tty->flow_stopped) {
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- return;
- }
- tty->stopped = 0;
- if (tty->link && tty->link->packet) {
- tty->ctrl_status &= ~TIOCPKT_STOP;
- tty->ctrl_status |= TIOCPKT_START;
- wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
- }
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- if (tty->ops->start)
- (tty->ops->start)(tty);
- /* If we have a running line discipline it may need kicking */
- tty_wakeup(tty);
-}
-
-EXPORT_SYMBOL(start_tty);
-
-/**
- * tty_read - read method for tty device files
- * @file: pointer to tty file
- * @buf: user buffer
- * @count: size of user buffer
- * @ppos: unused
- *
- * Perform the read system call function on this terminal device. Checks
- * for hung up devices before calling the line discipline method.
- *
- * Locking:
- * Locks the line discipline internally while needed. Multiple
- * read calls may be outstanding in parallel.
- */
-
-static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
- loff_t *ppos)
-{
- int i;
- struct inode *inode = file->f_path.dentry->d_inode;
- struct tty_struct *tty = file_tty(file);
- struct tty_ldisc *ld;
-
- if (tty_paranoia_check(tty, inode, "tty_read"))
- return -EIO;
- if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
- return -EIO;
-
- /* We want to wait for the line discipline to sort out in this
- situation */
- ld = tty_ldisc_ref_wait(tty);
- if (ld->ops->read)
- i = (ld->ops->read)(tty, file, buf, count);
- else
- i = -EIO;
- tty_ldisc_deref(ld);
- if (i > 0)
- inode->i_atime = current_fs_time(inode->i_sb);
- return i;
-}
-
-void tty_write_unlock(struct tty_struct *tty)
-{
- mutex_unlock(&tty->atomic_write_lock);
- wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
-}
-
-int tty_write_lock(struct tty_struct *tty, int ndelay)
-{
- if (!mutex_trylock(&tty->atomic_write_lock)) {
- if (ndelay)
- return -EAGAIN;
- if (mutex_lock_interruptible(&tty->atomic_write_lock))
- return -ERESTARTSYS;
- }
- return 0;
-}
-
-/*
- * Split writes up in sane blocksizes to avoid
- * denial-of-service type attacks
- */
-static inline ssize_t do_tty_write(
- ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t),
- struct tty_struct *tty,
- struct file *file,
- const char __user *buf,
- size_t count)
-{
- ssize_t ret, written = 0;
- unsigned int chunk;
-
- ret = tty_write_lock(tty, file->f_flags & O_NDELAY);
- if (ret < 0)
- return ret;
-
- /*
- * We chunk up writes into a temporary buffer. This
- * simplifies low-level drivers immensely, since they
- * don't have locking issues and user mode accesses.
- *
- * But if TTY_NO_WRITE_SPLIT is set, we should use a
- * big chunk-size..
- *
- * The default chunk-size is 2kB, because the NTTY
- * layer has problems with bigger chunks. It will
- * claim to be able to handle more characters than
- * it actually does.
- *
- * FIXME: This can probably go away now except that 64K chunks
- * are too likely to fail unless switched to vmalloc...
- */
- chunk = 2048;
- if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
- chunk = 65536;
- if (count < chunk)
- chunk = count;
-
- /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
- if (tty->write_cnt < chunk) {
- unsigned char *buf_chunk;
-
- if (chunk < 1024)
- chunk = 1024;
-
- buf_chunk = kmalloc(chunk, GFP_KERNEL);
- if (!buf_chunk) {
- ret = -ENOMEM;
- goto out;
- }
- kfree(tty->write_buf);
- tty->write_cnt = chunk;
- tty->write_buf = buf_chunk;
- }
-
- /* Do the write .. */
- for (;;) {
- size_t size = count;
- if (size > chunk)
- size = chunk;
- ret = -EFAULT;
- if (copy_from_user(tty->write_buf, buf, size))
- break;
- ret = write(tty, file, tty->write_buf, size);
- if (ret <= 0)
- break;
- written += ret;
- buf += ret;
- count -= ret;
- if (!count)
- break;
- ret = -ERESTARTSYS;
- if (signal_pending(current))
- break;
- cond_resched();
- }
- if (written) {
- struct inode *inode = file->f_path.dentry->d_inode;
- inode->i_mtime = current_fs_time(inode->i_sb);
- ret = written;
- }
-out:
- tty_write_unlock(tty);
- return ret;
-}
-
-/**
- * tty_write_message - write a message to a certain tty, not just the console.
- * @tty: the destination tty_struct
- * @msg: the message to write
- *
- * This is used for messages that need to be redirected to a specific tty.
- * We don't put it into the syslog queue right now maybe in the future if
- * really needed.
- *
- * We must still hold the BTM and test the CLOSING flag for the moment.
- */
-
-void tty_write_message(struct tty_struct *tty, char *msg)
-{
- if (tty) {
- mutex_lock(&tty->atomic_write_lock);
- tty_lock();
- if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) {
- tty_unlock();
- tty->ops->write(tty, msg, strlen(msg));
- } else
- tty_unlock();
- tty_write_unlock(tty);
- }
- return;
-}
-
-
-/**
- * tty_write - write method for tty device file
- * @file: tty file pointer
- * @buf: user data to write
- * @count: bytes to write
- * @ppos: unused
- *
- * Write data to a tty device via the line discipline.
- *
- * Locking:
- * Locks the line discipline as required
- * Writes to the tty driver are serialized by the atomic_write_lock
- * and are then processed in chunks to the device. The line discipline
- * write method will not be invoked in parallel for each device.
- */
-
-static ssize_t tty_write(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
-{
- struct inode *inode = file->f_path.dentry->d_inode;
- struct tty_struct *tty = file_tty(file);
- struct tty_ldisc *ld;
- ssize_t ret;
-
- if (tty_paranoia_check(tty, inode, "tty_write"))
- return -EIO;
- if (!tty || !tty->ops->write ||
- (test_bit(TTY_IO_ERROR, &tty->flags)))
- return -EIO;
- /* Short term debug to catch buggy drivers */
- if (tty->ops->write_room == NULL)
- printk(KERN_ERR "tty driver %s lacks a write_room method.\n",
- tty->driver->name);
- ld = tty_ldisc_ref_wait(tty);
- if (!ld->ops->write)
- ret = -EIO;
- else
- ret = do_tty_write(ld->ops->write, tty, file, buf, count);
- tty_ldisc_deref(ld);
- return ret;
-}
-
-ssize_t redirected_tty_write(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
-{
- struct file *p = NULL;
-
- spin_lock(&redirect_lock);
- if (redirect) {
- get_file(redirect);
- p = redirect;
- }
- spin_unlock(&redirect_lock);
-
- if (p) {
- ssize_t res;
- res = vfs_write(p, buf, count, &p->f_pos);
- fput(p);
- return res;
- }
- return tty_write(file, buf, count, ppos);
-}
-
-static char ptychar[] = "pqrstuvwxyzabcde";
-
-/**
- * pty_line_name - generate name for a pty
- * @driver: the tty driver in use
- * @index: the minor number
- * @p: output buffer of at least 6 bytes
- *
- * Generate a name from a driver reference and write it to the output
- * buffer.
- *
- * Locking: None
- */
-static void pty_line_name(struct tty_driver *driver, int index, char *p)
-{
- int i = index + driver->name_base;
- /* ->name is initialized to "ttyp", but "tty" is expected */
- sprintf(p, "%s%c%x",
- driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name,
- ptychar[i >> 4 & 0xf], i & 0xf);
-}
-
-/**
- * tty_line_name - generate name for a tty
- * @driver: the tty driver in use
- * @index: the minor number
- * @p: output buffer of at least 7 bytes
- *
- * Generate a name from a driver reference and write it to the output
- * buffer.
- *
- * Locking: None
- */
-static void tty_line_name(struct tty_driver *driver, int index, char *p)
-{
- sprintf(p, "%s%d", driver->name, index + driver->name_base);
-}
-
-/**
- * tty_driver_lookup_tty() - find an existing tty, if any
- * @driver: the driver for the tty
- * @idx: the minor number
- *
- * Return the tty, if found or ERR_PTR() otherwise.
- *
- * Locking: tty_mutex must be held. If tty is found, the mutex must
- * be held until the 'fast-open' is also done. Will change once we
- * have refcounting in the driver and per driver locking
- */
-static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
- struct inode *inode, int idx)
-{
- struct tty_struct *tty;
-
- if (driver->ops->lookup)
- return driver->ops->lookup(driver, inode, idx);
-
- tty = driver->ttys[idx];
- return tty;
-}
-
-/**
- * tty_init_termios - helper for termios setup
- * @tty: the tty to set up
- *
- * Initialise the termios structures for this tty. Thus runs under
- * the tty_mutex currently so we can be relaxed about ordering.
- */
-
-int tty_init_termios(struct tty_struct *tty)
-{
- struct ktermios *tp;
- int idx = tty->index;
-
- tp = tty->driver->termios[idx];
- if (tp == NULL) {
- tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
- if (tp == NULL)
- return -ENOMEM;
- memcpy(tp, &tty->driver->init_termios,
- sizeof(struct ktermios));
- tty->driver->termios[idx] = tp;
- }
- tty->termios = tp;
- tty->termios_locked = tp + 1;
-
- /* Compatibility until drivers always set this */
- tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
- tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
- return 0;
-}
-EXPORT_SYMBOL_GPL(tty_init_termios);
-
-/**
- * tty_driver_install_tty() - install a tty entry in the driver
- * @driver: the driver for the tty
- * @tty: the tty
- *
- * Install a tty object into the driver tables. The tty->index field
- * will be set by the time this is called. This method is responsible
- * for ensuring any need additional structures are allocated and
- * configured.
- *
- * Locking: tty_mutex for now
- */
-static int tty_driver_install_tty(struct tty_driver *driver,
- struct tty_struct *tty)
-{
- int idx = tty->index;
- int ret;
-
- if (driver->ops->install) {
- ret = driver->ops->install(driver, tty);
- return ret;
- }
-
- if (tty_init_termios(tty) == 0) {
- tty_driver_kref_get(driver);
- tty->count++;
- driver->ttys[idx] = tty;
- return 0;
- }
- return -ENOMEM;
-}
-
-/**
- * tty_driver_remove_tty() - remove a tty from the driver tables
- * @driver: the driver for the tty
- * @idx: the minor number
- *
- * Remvoe a tty object from the driver tables. The tty->index field
- * will be set by the time this is called.
- *
- * Locking: tty_mutex for now
- */
-static void tty_driver_remove_tty(struct tty_driver *driver,
- struct tty_struct *tty)
-{
- if (driver->ops->remove)
- driver->ops->remove(driver, tty);
- else
- driver->ttys[tty->index] = NULL;
-}
-
-/*
- * tty_reopen() - fast re-open of an open tty
- * @tty - the tty to open
- *
- * Return 0 on success, -errno on error.
- *
- * Locking: tty_mutex must be held from the time the tty was found
- * till this open completes.
- */
-static int tty_reopen(struct tty_struct *tty)
-{
- struct tty_driver *driver = tty->driver;
-
- if (test_bit(TTY_CLOSING, &tty->flags))
- return -EIO;
-
- if (driver->type == TTY_DRIVER_TYPE_PTY &&
- driver->subtype == PTY_TYPE_MASTER) {
- /*
- * special case for PTY masters: only one open permitted,
- * and the slave side open count is incremented as well.
- */
- if (tty->count)
- return -EIO;
-
- tty->link->count++;
- }
- tty->count++;
- tty->driver = driver; /* N.B. why do this every time?? */
-
- mutex_lock(&tty->ldisc_mutex);
- WARN_ON(!test_bit(TTY_LDISC, &tty->flags));
- mutex_unlock(&tty->ldisc_mutex);
-
- return 0;
-}
-
-/**
- * tty_init_dev - initialise a tty device
- * @driver: tty driver we are opening a device on
- * @idx: device index
- * @ret_tty: returned tty structure
- * @first_ok: ok to open a new device (used by ptmx)
- *
- * Prepare a tty device. This may not be a "new" clean device but
- * could also be an active device. The pty drivers require special
- * handling because of this.
- *
- * Locking:
- * The function is called under the tty_mutex, which
- * protects us from the tty struct or driver itself going away.
- *
- * On exit the tty device has the line discipline attached and
- * a reference count of 1. If a pair was created for pty/tty use
- * and the other was a pty master then it too has a reference count of 1.
- *
- * WSH 06/09/97: Rewritten to remove races and properly clean up after a
- * failed open. The new code protects the open with a mutex, so it's
- * really quite straightforward. The mutex locking can probably be
- * relaxed for the (most common) case of reopening a tty.
- */
-
-struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
- int first_ok)
-{
- struct tty_struct *tty;
- int retval;
-
- /* Check if pty master is being opened multiple times */
- if (driver->subtype == PTY_TYPE_MASTER &&
- (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) {
- return ERR_PTR(-EIO);
- }
-
- /*
- * First time open is complex, especially for PTY devices.
- * This code guarantees that either everything succeeds and the
- * TTY is ready for operation, or else the table slots are vacated
- * and the allocated memory released. (Except that the termios
- * and locked termios may be retained.)
- */
-
- if (!try_module_get(driver->owner))
- return ERR_PTR(-ENODEV);
-
- tty = alloc_tty_struct();
- if (!tty)
- goto fail_no_mem;
- initialize_tty_struct(tty, driver, idx);
-
- retval = tty_driver_install_tty(driver, tty);
- if (retval < 0) {
- free_tty_struct(tty);
- module_put(driver->owner);
- return ERR_PTR(retval);
- }
-
- /*
- * Structures all installed ... call the ldisc open routines.
- * If we fail here just call release_tty to clean up. No need
- * to decrement the use counts, as release_tty doesn't care.
- */
- retval = tty_ldisc_setup(tty, tty->link);
- if (retval)
- goto release_mem_out;
- return tty;
-
-fail_no_mem:
- module_put(driver->owner);
- return ERR_PTR(-ENOMEM);
-
- /* call the tty release_tty routine to clean out this slot */
-release_mem_out:
- if (printk_ratelimit())
- printk(KERN_INFO "tty_init_dev: ldisc open failed, "
- "clearing slot %d\n", idx);
- release_tty(tty, idx);
- return ERR_PTR(retval);
-}
-
-void tty_free_termios(struct tty_struct *tty)
-{
- struct ktermios *tp;
- int idx = tty->index;
- /* Kill this flag and push into drivers for locking etc */
- if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
- /* FIXME: Locking on ->termios array */
- tp = tty->termios;
- tty->driver->termios[idx] = NULL;
- kfree(tp);
- }
-}
-EXPORT_SYMBOL(tty_free_termios);
-
-void tty_shutdown(struct tty_struct *tty)
-{
- tty_driver_remove_tty(tty->driver, tty);
- tty_free_termios(tty);
-}
-EXPORT_SYMBOL(tty_shutdown);
-
-/**
- * release_one_tty - release tty structure memory
- * @kref: kref of tty we are obliterating
- *
- * Releases memory associated with a tty structure, and clears out the
- * driver table slots. This function is called when a device is no longer
- * in use. It also gets called when setup of a device fails.
- *
- * Locking:
- * tty_mutex - sometimes only
- * takes the file list lock internally when working on the list
- * of ttys that the driver keeps.
- *
- * This method gets called from a work queue so that the driver private
- * cleanup ops can sleep (needed for USB at least)
- */
-static void release_one_tty(struct work_struct *work)
-{
- struct tty_struct *tty =
- container_of(work, struct tty_struct, hangup_work);
- struct tty_driver *driver = tty->driver;
-
- if (tty->ops->cleanup)
- tty->ops->cleanup(tty);
-
- tty->magic = 0;
- tty_driver_kref_put(driver);
- module_put(driver->owner);
-
- spin_lock(&tty_files_lock);
- list_del_init(&tty->tty_files);
- spin_unlock(&tty_files_lock);
-
- put_pid(tty->pgrp);
- put_pid(tty->session);
- free_tty_struct(tty);
-}
-
-static void queue_release_one_tty(struct kref *kref)
-{
- struct tty_struct *tty = container_of(kref, struct tty_struct, kref);
-
- if (tty->ops->shutdown)
- tty->ops->shutdown(tty);
- else
- tty_shutdown(tty);
-
- /* The hangup queue is now free so we can reuse it rather than
- waste a chunk of memory for each port */
- INIT_WORK(&tty->hangup_work, release_one_tty);
- schedule_work(&tty->hangup_work);
-}
-
-/**
- * tty_kref_put - release a tty kref
- * @tty: tty device
- *
- * Release a reference to a tty device and if need be let the kref
- * layer destruct the object for us
- */
-
-void tty_kref_put(struct tty_struct *tty)
-{
- if (tty)
- kref_put(&tty->kref, queue_release_one_tty);
-}
-EXPORT_SYMBOL(tty_kref_put);
-
-/**
- * release_tty - release tty structure memory
- *
- * Release both @tty and a possible linked partner (think pty pair),
- * and decrement the refcount of the backing module.
- *
- * Locking:
- * tty_mutex - sometimes only
- * takes the file list lock internally when working on the list
- * of ttys that the driver keeps.
- * FIXME: should we require tty_mutex is held here ??
- *
- */
-static void release_tty(struct tty_struct *tty, int idx)
-{
- /* This should always be true but check for the moment */
- WARN_ON(tty->index != idx);
-
- if (tty->link)
- tty_kref_put(tty->link);
- tty_kref_put(tty);
-}
-
-/**
- * tty_release - vfs callback for close
- * @inode: inode of tty
- * @filp: file pointer for handle to tty
- *
- * Called the last time each file handle is closed that references
- * this tty. There may however be several such references.
- *
- * Locking:
- * Takes bkl. See tty_release_dev
- *
- * Even releasing the tty structures is a tricky business.. We have
- * to be very careful that the structures are all released at the
- * same time, as interrupts might otherwise get the wrong pointers.
- *
- * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
- * lead to double frees or releasing memory still in use.
- */
-
-int tty_release(struct inode *inode, struct file *filp)
-{
- struct tty_struct *tty = file_tty(filp);
- struct tty_struct *o_tty;
- int pty_master, tty_closing, o_tty_closing, do_sleep;
- int devpts;
- int idx;
- char buf[64];
-
- if (tty_paranoia_check(tty, inode, "tty_release_dev"))
- return 0;
-
- tty_lock();
- check_tty_count(tty, "tty_release_dev");
-
- __tty_fasync(-1, filp, 0);
-
- idx = tty->index;
- pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
- tty->driver->subtype == PTY_TYPE_MASTER);
- devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0;
- o_tty = tty->link;
-
-#ifdef TTY_PARANOIA_CHECK
- if (idx < 0 || idx >= tty->driver->num) {
- printk(KERN_DEBUG "tty_release_dev: bad idx when trying to "
- "free (%s)\n", tty->name);
- tty_unlock();
- return 0;
- }
- if (!devpts) {
- if (tty != tty->driver->ttys[idx]) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty "
- "for (%s)\n", idx, tty->name);
- return 0;
- }
- if (tty->termios != tty->driver->termios[idx]) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios "
- "for (%s)\n",
- idx, tty->name);
- return 0;
- }
- }
-#endif
-
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...",
- tty_name(tty, buf), tty->count);
-#endif
-
-#ifdef TTY_PARANOIA_CHECK
- if (tty->driver->other &&
- !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
- if (o_tty != tty->driver->other->ttys[idx]) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: other->table[%d] "
- "not o_tty for (%s)\n",
- idx, tty->name);
- return 0 ;
- }
- if (o_tty->termios != tty->driver->other->termios[idx]) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: other->termios[%d] "
- "not o_termios for (%s)\n",
- idx, tty->name);
- return 0;
- }
- if (o_tty->link != tty) {
- tty_unlock();
- printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n");
- return 0;
- }
- }
-#endif
- if (tty->ops->close)
- tty->ops->close(tty, filp);
-
- tty_unlock();
- /*
- * Sanity check: if tty->count is going to zero, there shouldn't be
- * any waiters on tty->read_wait or tty->write_wait. We test the
- * wait queues and kick everyone out _before_ actually starting to
- * close. This ensures that we won't block while releasing the tty
- * structure.
- *
- * The test for the o_tty closing is necessary, since the master and
- * slave sides may close in any order. If the slave side closes out
- * first, its count will be one, since the master side holds an open.
- * Thus this test wouldn't be triggered at the time the slave closes,
- * so we do it now.
- *
- * Note that it's possible for the tty to be opened again while we're
- * flushing out waiters. By recalculating the closing flags before
- * each iteration we avoid any problems.
- */
- while (1) {
- /* Guard against races with tty->count changes elsewhere and
- opens on /dev/tty */
-
- mutex_lock(&tty_mutex);
- tty_lock();
- tty_closing = tty->count <= 1;
- o_tty_closing = o_tty &&
- (o_tty->count <= (pty_master ? 1 : 0));
- do_sleep = 0;
-
- if (tty_closing) {
- if (waitqueue_active(&tty->read_wait)) {
- wake_up_poll(&tty->read_wait, POLLIN);
- do_sleep++;
- }
- if (waitqueue_active(&tty->write_wait)) {
- wake_up_poll(&tty->write_wait, POLLOUT);
- do_sleep++;
- }
- }
- if (o_tty_closing) {
- if (waitqueue_active(&o_tty->read_wait)) {
- wake_up_poll(&o_tty->read_wait, POLLIN);
- do_sleep++;
- }
- if (waitqueue_active(&o_tty->write_wait)) {
- wake_up_poll(&o_tty->write_wait, POLLOUT);
- do_sleep++;
- }
- }
- if (!do_sleep)
- break;
-
- printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue "
- "active!\n", tty_name(tty, buf));
- tty_unlock();
- mutex_unlock(&tty_mutex);
- schedule();
- }
-
- /*
- * The closing flags are now consistent with the open counts on
- * both sides, and we've completed the last operation that could
- * block, so it's safe to proceed with closing.
- */
- if (pty_master) {
- if (--o_tty->count < 0) {
- printk(KERN_WARNING "tty_release_dev: bad pty slave count "
- "(%d) for %s\n",
- o_tty->count, tty_name(o_tty, buf));
- o_tty->count = 0;
- }
- }
- if (--tty->count < 0) {
- printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n",
- tty->count, tty_name(tty, buf));
- tty->count = 0;
- }
-
- /*
- * We've decremented tty->count, so we need to remove this file
- * descriptor off the tty->tty_files list; this serves two
- * purposes:
- * - check_tty_count sees the correct number of file descriptors
- * associated with this tty.
- * - do_tty_hangup no longer sees this file descriptor as
- * something that needs to be handled for hangups.
- */
- tty_del_file(filp);
-
- /*
- * Perform some housekeeping before deciding whether to return.
- *
- * Set the TTY_CLOSING flag if this was the last open. In the
- * case of a pty we may have to wait around for the other side
- * to close, and TTY_CLOSING makes sure we can't be reopened.
- */
- if (tty_closing)
- set_bit(TTY_CLOSING, &tty->flags);
- if (o_tty_closing)
- set_bit(TTY_CLOSING, &o_tty->flags);
-
- /*
- * If _either_ side is closing, make sure there aren't any
- * processes that still think tty or o_tty is their controlling
- * tty.
- */
- if (tty_closing || o_tty_closing) {
- read_lock(&tasklist_lock);
- session_clear_tty(tty->session);
- if (o_tty)
- session_clear_tty(o_tty->session);
- read_unlock(&tasklist_lock);
- }
-
- mutex_unlock(&tty_mutex);
-
- /* check whether both sides are closing ... */
- if (!tty_closing || (o_tty && !o_tty_closing)) {
- tty_unlock();
- return 0;
- }
-
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "freeing tty structure...");
-#endif
- /*
- * Ask the line discipline code to release its structures
- */
- tty_ldisc_release(tty, o_tty);
- /*
- * The release_tty function takes care of the details of clearing
- * the slots and preserving the termios structure.
- */
- release_tty(tty, idx);
-
- /* Make this pty number available for reallocation */
- if (devpts)
- devpts_kill_index(inode, idx);
- tty_unlock();
- return 0;
-}
-
-/**
- * tty_open - open a tty device
- * @inode: inode of device file
- * @filp: file pointer to tty
- *
- * tty_open and tty_release keep up the tty count that contains the
- * number of opens done on a tty. We cannot use the inode-count, as
- * different inodes might point to the same tty.
- *
- * Open-counting is needed for pty masters, as well as for keeping
- * track of serial lines: DTR is dropped when the last close happens.
- * (This is not done solely through tty->count, now. - Ted 1/27/92)
- *
- * The termios state of a pty is reset on first open so that
- * settings don't persist across reuse.
- *
- * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work.
- * tty->count should protect the rest.
- * ->siglock protects ->signal/->sighand
- */
-
-static int tty_open(struct inode *inode, struct file *filp)
-{
- struct tty_struct *tty = NULL;
- int noctty, retval;
- struct tty_driver *driver;
- int index;
- dev_t device = inode->i_rdev;
- unsigned saved_flags = filp->f_flags;
-
- nonseekable_open(inode, filp);
-
-retry_open:
- noctty = filp->f_flags & O_NOCTTY;
- index = -1;
- retval = 0;
-
- mutex_lock(&tty_mutex);
- tty_lock();
-
- if (device == MKDEV(TTYAUX_MAJOR, 0)) {
- tty = get_current_tty();
- if (!tty) {
- tty_unlock();
- mutex_unlock(&tty_mutex);
- return -ENXIO;
- }
- driver = tty_driver_kref_get(tty->driver);
- index = tty->index;
- filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
- /* noctty = 1; */
- /* FIXME: Should we take a driver reference ? */
- tty_kref_put(tty);
- goto got_driver;
- }
-#ifdef CONFIG_VT
- if (device == MKDEV(TTY_MAJOR, 0)) {
- extern struct tty_driver *console_driver;
- driver = tty_driver_kref_get(console_driver);
- index = fg_console;
- noctty = 1;
- goto got_driver;
- }
-#endif
- if (device == MKDEV(TTYAUX_MAJOR, 1)) {
- struct tty_driver *console_driver = console_device(&index);
- if (console_driver) {
- driver = tty_driver_kref_get(console_driver);
- if (driver) {
- /* Don't let /dev/console block */
- filp->f_flags |= O_NONBLOCK;
- noctty = 1;
- goto got_driver;
- }
- }
- tty_unlock();
- mutex_unlock(&tty_mutex);
- return -ENODEV;
- }
-
- driver = get_tty_driver(device, &index);
- if (!driver) {
- tty_unlock();
- mutex_unlock(&tty_mutex);
- return -ENODEV;
- }
-got_driver:
- if (!tty) {
- /* check whether we're reopening an existing tty */
- tty = tty_driver_lookup_tty(driver, inode, index);
-
- if (IS_ERR(tty)) {
- tty_unlock();
- mutex_unlock(&tty_mutex);
- return PTR_ERR(tty);
- }
- }
-
- if (tty) {
- retval = tty_reopen(tty);
- if (retval)
- tty = ERR_PTR(retval);
- } else
- tty = tty_init_dev(driver, index, 0);
-
- mutex_unlock(&tty_mutex);
- tty_driver_kref_put(driver);
- if (IS_ERR(tty)) {
- tty_unlock();
- return PTR_ERR(tty);
- }
-
- retval = tty_add_file(tty, filp);
- if (retval) {
- tty_unlock();
- return retval;
- }
-
- check_tty_count(tty, "tty_open");
- if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
- tty->driver->subtype == PTY_TYPE_MASTER)
- noctty = 1;
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "opening %s...", tty->name);
-#endif
- if (!retval) {
- if (tty->ops->open)
- retval = tty->ops->open(tty, filp);
- else
- retval = -ENODEV;
- }
- filp->f_flags = saved_flags;
-
- if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) &&
- !capable(CAP_SYS_ADMIN))
- retval = -EBUSY;
-
- if (retval) {
-#ifdef TTY_DEBUG_HANGUP
- printk(KERN_DEBUG "error %d in opening %s...", retval,
- tty->name);
-#endif
- tty_unlock(); /* need to call tty_release without BTM */
- tty_release(inode, filp);
- if (retval != -ERESTARTSYS)
- return retval;
-
- if (signal_pending(current))
- return retval;
-
- schedule();
- /*
- * Need to reset f_op in case a hangup happened.
- */
- tty_lock();
- if (filp->f_op == &hung_up_tty_fops)
- filp->f_op = &tty_fops;
- tty_unlock();
- goto retry_open;
- }
- tty_unlock();
-
-
- mutex_lock(&tty_mutex);
- tty_lock();
- spin_lock_irq(¤t->sighand->siglock);
- if (!noctty &&
- current->signal->leader &&
- !current->signal->tty &&
- tty->session == NULL)
- __proc_set_tty(current, tty);
- spin_unlock_irq(¤t->sighand->siglock);
- tty_unlock();
- mutex_unlock(&tty_mutex);
- return 0;
-}
-
-
-
-/**
- * tty_poll - check tty status
- * @filp: file being polled
- * @wait: poll wait structures to update
- *
- * Call the line discipline polling method to obtain the poll
- * status of the device.
- *
- * Locking: locks called line discipline but ldisc poll method
- * may be re-entered freely by other callers.
- */
-
-static unsigned int tty_poll(struct file *filp, poll_table *wait)
-{
- struct tty_struct *tty = file_tty(filp);
- struct tty_ldisc *ld;
- int ret = 0;
-
- if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll"))
- return 0;
-
- ld = tty_ldisc_ref_wait(tty);
- if (ld->ops->poll)
- ret = (ld->ops->poll)(tty, filp, wait);
- tty_ldisc_deref(ld);
- return ret;
-}
-
-static int __tty_fasync(int fd, struct file *filp, int on)
-{
- struct tty_struct *tty = file_tty(filp);
- unsigned long flags;
- int retval = 0;
-
- if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync"))
- goto out;
-
- retval = fasync_helper(fd, filp, on, &tty->fasync);
- if (retval <= 0)
- goto out;
-
- if (on) {
- enum pid_type type;
- struct pid *pid;
- if (!waitqueue_active(&tty->read_wait))
- tty->minimum_to_wake = 1;
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- if (tty->pgrp) {
- pid = tty->pgrp;
- type = PIDTYPE_PGID;
- } else {
- pid = task_pid(current);
- type = PIDTYPE_PID;
- }
- get_pid(pid);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- retval = __f_setown(filp, pid, type, 0);
- put_pid(pid);
- if (retval)
- goto out;
- } else {
- if (!tty->fasync && !waitqueue_active(&tty->read_wait))
- tty->minimum_to_wake = N_TTY_BUF_SIZE;
- }
- retval = 0;
-out:
- return retval;
-}
-
-static int tty_fasync(int fd, struct file *filp, int on)
-{
- int retval;
- tty_lock();
- retval = __tty_fasync(fd, filp, on);
- tty_unlock();
- return retval;
-}
-
-/**
- * tiocsti - fake input character
- * @tty: tty to fake input into
- * @p: pointer to character
- *
- * Fake input to a tty device. Does the necessary locking and
- * input management.
- *
- * FIXME: does not honour flow control ??
- *
- * Locking:
- * Called functions take tty_ldisc_lock
- * current->signal->tty check is safe without locks
- *
- * FIXME: may race normal receive processing
- */
-
-static int tiocsti(struct tty_struct *tty, char __user *p)
-{
- char ch, mbz = 0;
- struct tty_ldisc *ld;
-
- if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN))
- return -EPERM;
- if (get_user(ch, p))
- return -EFAULT;
- tty_audit_tiocsti(tty, ch);
- ld = tty_ldisc_ref_wait(tty);
- ld->ops->receive_buf(tty, &ch, &mbz, 1);
- tty_ldisc_deref(ld);
- return 0;
-}
-
-/**
- * tiocgwinsz - implement window query ioctl
- * @tty; tty
- * @arg: user buffer for result
- *
- * Copies the kernel idea of the window size into the user buffer.
- *
- * Locking: tty->termios_mutex is taken to ensure the winsize data
- * is consistent.
- */
-
-static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
-{
- int err;
-
- mutex_lock(&tty->termios_mutex);
- err = copy_to_user(arg, &tty->winsize, sizeof(*arg));
- mutex_unlock(&tty->termios_mutex);
-
- return err ? -EFAULT: 0;
-}
-
-/**
- * tty_do_resize - resize event
- * @tty: tty being resized
- * @rows: rows (character)
- * @cols: cols (character)
- *
- * Update the termios variables and send the necessary signals to
- * peform a terminal resize correctly
- */
-
-int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
-{
- struct pid *pgrp;
- unsigned long flags;
-
- /* Lock the tty */
- mutex_lock(&tty->termios_mutex);
- if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
- goto done;
- /* Get the PID values and reference them so we can
- avoid holding the tty ctrl lock while sending signals */
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- pgrp = get_pid(tty->pgrp);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-
- if (pgrp)
- kill_pgrp(pgrp, SIGWINCH, 1);
- put_pid(pgrp);
-
- tty->winsize = *ws;
-done:
- mutex_unlock(&tty->termios_mutex);
- return 0;
-}
-
-/**
- * tiocswinsz - implement window size set ioctl
- * @tty; tty side of tty
- * @arg: user buffer for result
- *
- * Copies the user idea of the window size to the kernel. Traditionally
- * this is just advisory information but for the Linux console it
- * actually has driver level meaning and triggers a VC resize.
- *
- * Locking:
- * Driver dependant. The default do_resize method takes the
- * tty termios mutex and ctrl_lock. The console takes its own lock
- * then calls into the default method.
- */
-
-static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg)
-{
- struct winsize tmp_ws;
- if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
- return -EFAULT;
-
- if (tty->ops->resize)
- return tty->ops->resize(tty, &tmp_ws);
- else
- return tty_do_resize(tty, &tmp_ws);
-}
-
-/**
- * tioccons - allow admin to move logical console
- * @file: the file to become console
- *
- * Allow the adminstrator to move the redirected console device
- *
- * Locking: uses redirect_lock to guard the redirect information
- */
-
-static int tioccons(struct file *file)
-{
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- if (file->f_op->write == redirected_tty_write) {
- struct file *f;
- spin_lock(&redirect_lock);
- f = redirect;
- redirect = NULL;
- spin_unlock(&redirect_lock);
- if (f)
- fput(f);
- return 0;
- }
- spin_lock(&redirect_lock);
- if (redirect) {
- spin_unlock(&redirect_lock);
- return -EBUSY;
- }
- get_file(file);
- redirect = file;
- spin_unlock(&redirect_lock);
- return 0;
-}
-
-/**
- * fionbio - non blocking ioctl
- * @file: file to set blocking value
- * @p: user parameter
- *
- * Historical tty interfaces had a blocking control ioctl before
- * the generic functionality existed. This piece of history is preserved
- * in the expected tty API of posix OS's.
- *
- * Locking: none, the open file handle ensures it won't go away.
- */
-
-static int fionbio(struct file *file, int __user *p)
-{
- int nonblock;
-
- if (get_user(nonblock, p))
- return -EFAULT;
-
- spin_lock(&file->f_lock);
- if (nonblock)
- file->f_flags |= O_NONBLOCK;
- else
- file->f_flags &= ~O_NONBLOCK;
- spin_unlock(&file->f_lock);
- return 0;
-}
-
-/**
- * tiocsctty - set controlling tty
- * @tty: tty structure
- * @arg: user argument
- *
- * This ioctl is used to manage job control. It permits a session
- * leader to set this tty as the controlling tty for the session.
- *
- * Locking:
- * Takes tty_mutex() to protect tty instance
- * Takes tasklist_lock internally to walk sessions
- * Takes ->siglock() when updating signal->tty
- */
-
-static int tiocsctty(struct tty_struct *tty, int arg)
-{
- int ret = 0;
- if (current->signal->leader && (task_session(current) == tty->session))
- return ret;
-
- mutex_lock(&tty_mutex);
- /*
- * The process must be a session leader and
- * not have a controlling tty already.
- */
- if (!current->signal->leader || current->signal->tty) {
- ret = -EPERM;
- goto unlock;
- }
-
- if (tty->session) {
- /*
- * This tty is already the controlling
- * tty for another session group!
- */
- if (arg == 1 && capable(CAP_SYS_ADMIN)) {
- /*
- * Steal it away
- */
- read_lock(&tasklist_lock);
- session_clear_tty(tty->session);
- read_unlock(&tasklist_lock);
- } else {
- ret = -EPERM;
- goto unlock;
- }
- }
- proc_set_tty(current, tty);
-unlock:
- mutex_unlock(&tty_mutex);
- return ret;
-}
-
-/**
- * tty_get_pgrp - return a ref counted pgrp pid
- * @tty: tty to read
- *
- * Returns a refcounted instance of the pid struct for the process
- * group controlling the tty.
- */
-
-struct pid *tty_get_pgrp(struct tty_struct *tty)
-{
- unsigned long flags;
- struct pid *pgrp;
-
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- pgrp = get_pid(tty->pgrp);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-
- return pgrp;
-}
-EXPORT_SYMBOL_GPL(tty_get_pgrp);
-
-/**
- * tiocgpgrp - get process group
- * @tty: tty passed by user
- * @real_tty: tty side of the tty pased by the user if a pty else the tty
- * @p: returned pid
- *
- * Obtain the process group of the tty. If there is no process group
- * return an error.
- *
- * Locking: none. Reference to current->signal->tty is safe.
- */
-
-static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
-{
- struct pid *pid;
- int ret;
- /*
- * (tty == real_tty) is a cheap way of
- * testing if the tty is NOT a master pty.
- */
- if (tty == real_tty && current->signal->tty != real_tty)
- return -ENOTTY;
- pid = tty_get_pgrp(real_tty);
- ret = put_user(pid_vnr(pid), p);
- put_pid(pid);
- return ret;
-}
-
-/**
- * tiocspgrp - attempt to set process group
- * @tty: tty passed by user
- * @real_tty: tty side device matching tty passed by user
- * @p: pid pointer
- *
- * Set the process group of the tty to the session passed. Only
- * permitted where the tty session is our session.
- *
- * Locking: RCU, ctrl lock
- */
-
-static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
-{
- struct pid *pgrp;
- pid_t pgrp_nr;
- int retval = tty_check_change(real_tty);
- unsigned long flags;
-
- if (retval == -EIO)
- return -ENOTTY;
- if (retval)
- return retval;
- if (!current->signal->tty ||
- (current->signal->tty != real_tty) ||
- (real_tty->session != task_session(current)))
- return -ENOTTY;
- if (get_user(pgrp_nr, p))
- return -EFAULT;
- if (pgrp_nr < 0)
- return -EINVAL;
- rcu_read_lock();
- pgrp = find_vpid(pgrp_nr);
- retval = -ESRCH;
- if (!pgrp)
- goto out_unlock;
- retval = -EPERM;
- if (session_of_pgrp(pgrp) != task_session(current))
- goto out_unlock;
- retval = 0;
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- put_pid(real_tty->pgrp);
- real_tty->pgrp = get_pid(pgrp);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
-out_unlock:
- rcu_read_unlock();
- return retval;
-}
-
-/**
- * tiocgsid - get session id
- * @tty: tty passed by user
- * @real_tty: tty side of the tty pased by the user if a pty else the tty
- * @p: pointer to returned session id
- *
- * Obtain the session id of the tty. If there is no session
- * return an error.
- *
- * Locking: none. Reference to current->signal->tty is safe.
- */
-
-static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
-{
- /*
- * (tty == real_tty) is a cheap way of
- * testing if the tty is NOT a master pty.
- */
- if (tty == real_tty && current->signal->tty != real_tty)
- return -ENOTTY;
- if (!real_tty->session)
- return -ENOTTY;
- return put_user(pid_vnr(real_tty->session), p);
-}
-
-/**
- * tiocsetd - set line discipline
- * @tty: tty device
- * @p: pointer to user data
- *
- * Set the line discipline according to user request.
- *
- * Locking: see tty_set_ldisc, this function is just a helper
- */
-
-static int tiocsetd(struct tty_struct *tty, int __user *p)
-{
- int ldisc;
- int ret;
-
- if (get_user(ldisc, p))
- return -EFAULT;
-
- ret = tty_set_ldisc(tty, ldisc);
-
- return ret;
-}
-
-/**
- * send_break - performed time break
- * @tty: device to break on
- * @duration: timeout in mS
- *
- * Perform a timed break on hardware that lacks its own driver level
- * timed break functionality.
- *
- * Locking:
- * atomic_write_lock serializes
- *
- */
-
-static int send_break(struct tty_struct *tty, unsigned int duration)
-{
- int retval;
-
- if (tty->ops->break_ctl == NULL)
- return 0;
-
- if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
- retval = tty->ops->break_ctl(tty, duration);
- else {
- /* Do the work ourselves */
- if (tty_write_lock(tty, 0) < 0)
- return -EINTR;
- retval = tty->ops->break_ctl(tty, -1);
- if (retval)
- goto out;
- if (!signal_pending(current))
- msleep_interruptible(duration);
- retval = tty->ops->break_ctl(tty, 0);
-out:
- tty_write_unlock(tty);
- if (signal_pending(current))
- retval = -EINTR;
- }
- return retval;
-}
-
-/**
- * tty_tiocmget - get modem status
- * @tty: tty device
- * @file: user file pointer
- * @p: pointer to result
- *
- * Obtain the modem status bits from the tty driver if the feature
- * is supported. Return -EINVAL if it is not available.
- *
- * Locking: none (up to the driver)
- */
-
-static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p)
-{
- int retval = -EINVAL;
-
- if (tty->ops->tiocmget) {
- retval = tty->ops->tiocmget(tty, file);
-
- if (retval >= 0)
- retval = put_user(retval, p);
- }
- return retval;
-}
-
-/**
- * tty_tiocmset - set modem status
- * @tty: tty device
- * @file: user file pointer
- * @cmd: command - clear bits, set bits or set all
- * @p: pointer to desired bits
- *
- * Set the modem status bits from the tty driver if the feature
- * is supported. Return -EINVAL if it is not available.
- *
- * Locking: none (up to the driver)
- */
-
-static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd,
- unsigned __user *p)
-{
- int retval;
- unsigned int set, clear, val;
-
- if (tty->ops->tiocmset == NULL)
- return -EINVAL;
-
- retval = get_user(val, p);
- if (retval)
- return retval;
- set = clear = 0;
- switch (cmd) {
- case TIOCMBIS:
- set = val;
- break;
- case TIOCMBIC:
- clear = val;
- break;
- case TIOCMSET:
- set = val;
- clear = ~val;
- break;
- }
- set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
- clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
- return tty->ops->tiocmset(tty, file, set, clear);
-}
-
-static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
-{
- int retval = -EINVAL;
- struct serial_icounter_struct icount;
- memset(&icount, 0, sizeof(icount));
- if (tty->ops->get_icount)
- retval = tty->ops->get_icount(tty, &icount);
- if (retval != 0)
- return retval;
- if (copy_to_user(arg, &icount, sizeof(icount)))
- return -EFAULT;
- return 0;
-}
-
-struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
-{
- if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
- tty->driver->subtype == PTY_TYPE_MASTER)
- tty = tty->link;
- return tty;
-}
-EXPORT_SYMBOL(tty_pair_get_tty);
-
-struct tty_struct *tty_pair_get_pty(struct tty_struct *tty)
-{
- if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
- tty->driver->subtype == PTY_TYPE_MASTER)
- return tty;
- return tty->link;
-}
-EXPORT_SYMBOL(tty_pair_get_pty);
-
-/*
- * Split this up, as gcc can choke on it otherwise..
- */
-long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
- struct tty_struct *tty = file_tty(file);
- struct tty_struct *real_tty;
- void __user *p = (void __user *)arg;
- int retval;
- struct tty_ldisc *ld;
- struct inode *inode = file->f_dentry->d_inode;
-
- if (tty_paranoia_check(tty, inode, "tty_ioctl"))
- return -EINVAL;
-
- real_tty = tty_pair_get_tty(tty);
-
- /*
- * Factor out some common prep work
- */
- switch (cmd) {
- case TIOCSETD:
- case TIOCSBRK:
- case TIOCCBRK:
- case TCSBRK:
- case TCSBRKP:
- retval = tty_check_change(tty);
- if (retval)
- return retval;
- if (cmd != TIOCCBRK) {
- tty_wait_until_sent(tty, 0);
- if (signal_pending(current))
- return -EINTR;
- }
- break;
- }
-
- /*
- * Now do the stuff.
- */
- switch (cmd) {
- case TIOCSTI:
- return tiocsti(tty, p);
- case TIOCGWINSZ:
- return tiocgwinsz(real_tty, p);
- case TIOCSWINSZ:
- return tiocswinsz(real_tty, p);
- case TIOCCONS:
- return real_tty != tty ? -EINVAL : tioccons(file);
- case FIONBIO:
- return fionbio(file, p);
- case TIOCEXCL:
- set_bit(TTY_EXCLUSIVE, &tty->flags);
- return 0;
- case TIOCNXCL:
- clear_bit(TTY_EXCLUSIVE, &tty->flags);
- return 0;
- case TIOCNOTTY:
- if (current->signal->tty != tty)
- return -ENOTTY;
- no_tty();
- return 0;
- case TIOCSCTTY:
- return tiocsctty(tty, arg);
- case TIOCGPGRP:
- return tiocgpgrp(tty, real_tty, p);
- case TIOCSPGRP:
- return tiocspgrp(tty, real_tty, p);
- case TIOCGSID:
- return tiocgsid(tty, real_tty, p);
- case TIOCGETD:
- return put_user(tty->ldisc->ops->num, (int __user *)p);
- case TIOCSETD:
- return tiocsetd(tty, p);
- /*
- * Break handling
- */
- case TIOCSBRK: /* Turn break on, unconditionally */
- if (tty->ops->break_ctl)
- return tty->ops->break_ctl(tty, -1);
- return 0;
- case TIOCCBRK: /* Turn break off, unconditionally */
- if (tty->ops->break_ctl)
- return tty->ops->break_ctl(tty, 0);
- return 0;
- case TCSBRK: /* SVID version: non-zero arg --> no break */
- /* non-zero arg means wait for all output data
- * to be sent (performed above) but don't send break.
- * This is used by the tcdrain() termios function.
- */
- if (!arg)
- return send_break(tty, 250);
- return 0;
- case TCSBRKP: /* support for POSIX tcsendbreak() */
- return send_break(tty, arg ? arg*100 : 250);
-
- case TIOCMGET:
- return tty_tiocmget(tty, file, p);
- case TIOCMSET:
- case TIOCMBIC:
- case TIOCMBIS:
- return tty_tiocmset(tty, file, cmd, p);
- case TIOCGICOUNT:
- retval = tty_tiocgicount(tty, p);
- /* For the moment allow fall through to the old method */
- if (retval != -EINVAL)
- return retval;
- break;
- case TCFLSH:
- switch (arg) {
- case TCIFLUSH:
- case TCIOFLUSH:
- /* flush tty buffer and allow ldisc to process ioctl */
- tty_buffer_flush(tty);
- break;
- }
- break;
- }
- if (tty->ops->ioctl) {
- retval = (tty->ops->ioctl)(tty, file, cmd, arg);
- if (retval != -ENOIOCTLCMD)
- return retval;
- }
- ld = tty_ldisc_ref_wait(tty);
- retval = -EINVAL;
- if (ld->ops->ioctl) {
- retval = ld->ops->ioctl(tty, file, cmd, arg);
- if (retval == -ENOIOCTLCMD)
- retval = -EINVAL;
- }
- tty_ldisc_deref(ld);
- return retval;
-}
-
-#ifdef CONFIG_COMPAT
-static long tty_compat_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- struct inode *inode = file->f_dentry->d_inode;
- struct tty_struct *tty = file_tty(file);
- struct tty_ldisc *ld;
- int retval = -ENOIOCTLCMD;
-
- if (tty_paranoia_check(tty, inode, "tty_ioctl"))
- return -EINVAL;
-
- if (tty->ops->compat_ioctl) {
- retval = (tty->ops->compat_ioctl)(tty, file, cmd, arg);
- if (retval != -ENOIOCTLCMD)
- return retval;
- }
-
- ld = tty_ldisc_ref_wait(tty);
- if (ld->ops->compat_ioctl)
- retval = ld->ops->compat_ioctl(tty, file, cmd, arg);
- tty_ldisc_deref(ld);
-
- return retval;
-}
-#endif
-
-/*
- * This implements the "Secure Attention Key" --- the idea is to
- * prevent trojan horses by killing all processes associated with this
- * tty when the user hits the "Secure Attention Key". Required for
- * super-paranoid applications --- see the Orange Book for more details.
- *
- * This code could be nicer; ideally it should send a HUP, wait a few
- * seconds, then send a INT, and then a KILL signal. But you then
- * have to coordinate with the init process, since all processes associated
- * with the current tty must be dead before the new getty is allowed
- * to spawn.
- *
- * Now, if it would be correct ;-/ The current code has a nasty hole -
- * it doesn't catch files in flight. We may send the descriptor to ourselves
- * via AF_UNIX socket, close it and later fetch from socket. FIXME.
- *
- * Nasty bug: do_SAK is being called in interrupt context. This can
- * deadlock. We punt it up to process context. AKPM - 16Mar2001
- */
-void __do_SAK(struct tty_struct *tty)
-{
-#ifdef TTY_SOFT_SAK
- tty_hangup(tty);
-#else
- struct task_struct *g, *p;
- struct pid *session;
- int i;
- struct file *filp;
- struct fdtable *fdt;
-
- if (!tty)
- return;
- session = tty->session;
-
- tty_ldisc_flush(tty);
-
- tty_driver_flush_buffer(tty);
-
- read_lock(&tasklist_lock);
- /* Kill the entire session */
- do_each_pid_task(session, PIDTYPE_SID, p) {
- printk(KERN_NOTICE "SAK: killed process %d"
- " (%s): task_session(p)==tty->session\n",
- task_pid_nr(p), p->comm);
- send_sig(SIGKILL, p, 1);
- } while_each_pid_task(session, PIDTYPE_SID, p);
- /* Now kill any processes that happen to have the
- * tty open.
- */
- do_each_thread(g, p) {
- if (p->signal->tty == tty) {
- printk(KERN_NOTICE "SAK: killed process %d"
- " (%s): task_session(p)==tty->session\n",
- task_pid_nr(p), p->comm);
- send_sig(SIGKILL, p, 1);
- continue;
- }
- task_lock(p);
- if (p->files) {
- /*
- * We don't take a ref to the file, so we must
- * hold ->file_lock instead.
- */
- spin_lock(&p->files->file_lock);
- fdt = files_fdtable(p->files);
- for (i = 0; i < fdt->max_fds; i++) {
- filp = fcheck_files(p->files, i);
- if (!filp)
- continue;
- if (filp->f_op->read == tty_read &&
- file_tty(filp) == tty) {
- printk(KERN_NOTICE "SAK: killed process %d"
- " (%s): fd#%d opened to the tty\n",
- task_pid_nr(p), p->comm, i);
- force_sig(SIGKILL, p);
- break;
- }
- }
- spin_unlock(&p->files->file_lock);
- }
- task_unlock(p);
- } while_each_thread(g, p);
- read_unlock(&tasklist_lock);
-#endif
-}
-
-static void do_SAK_work(struct work_struct *work)
-{
- struct tty_struct *tty =
- container_of(work, struct tty_struct, SAK_work);
- __do_SAK(tty);
-}
-
-/*
- * The tq handling here is a little racy - tty->SAK_work may already be queued.
- * Fortunately we don't need to worry, because if ->SAK_work is already queued,
- * the values which we write to it will be identical to the values which it
- * already has. --akpm
- */
-void do_SAK(struct tty_struct *tty)
-{
- if (!tty)
- return;
- schedule_work(&tty->SAK_work);
-}
-
-EXPORT_SYMBOL(do_SAK);
-
-static int dev_match_devt(struct device *dev, void *data)
-{
- dev_t *devt = data;
- return dev->devt == *devt;
-}
-
-/* Must put_device() after it's unused! */
-static struct device *tty_get_device(struct tty_struct *tty)
-{
- dev_t devt = tty_devnum(tty);
- return class_find_device(tty_class, NULL, &devt, dev_match_devt);
-}
-
-
-/**
- * initialize_tty_struct
- * @tty: tty to initialize
- *
- * This subroutine initializes a tty structure that has been newly
- * allocated.
- *
- * Locking: none - tty in question must not be exposed at this point
- */
-
-void initialize_tty_struct(struct tty_struct *tty,
- struct tty_driver *driver, int idx)
-{
- memset(tty, 0, sizeof(struct tty_struct));
- kref_init(&tty->kref);
- tty->magic = TTY_MAGIC;
- tty_ldisc_init(tty);
- tty->session = NULL;
- tty->pgrp = NULL;
- tty->overrun_time = jiffies;
- tty->buf.head = tty->buf.tail = NULL;
- tty_buffer_init(tty);
- mutex_init(&tty->termios_mutex);
- mutex_init(&tty->ldisc_mutex);
- init_waitqueue_head(&tty->write_wait);
- init_waitqueue_head(&tty->read_wait);
- INIT_WORK(&tty->hangup_work, do_tty_hangup);
- mutex_init(&tty->atomic_read_lock);
- mutex_init(&tty->atomic_write_lock);
- mutex_init(&tty->output_lock);
- mutex_init(&tty->echo_lock);
- spin_lock_init(&tty->read_lock);
- spin_lock_init(&tty->ctrl_lock);
- INIT_LIST_HEAD(&tty->tty_files);
- INIT_WORK(&tty->SAK_work, do_SAK_work);
-
- tty->driver = driver;
- tty->ops = driver->ops;
- tty->index = idx;
- tty_line_name(driver, idx, tty->name);
- tty->dev = tty_get_device(tty);
-}
-
-/**
- * tty_put_char - write one character to a tty
- * @tty: tty
- * @ch: character
- *
- * Write one byte to the tty using the provided put_char method
- * if present. Returns the number of characters successfully output.
- *
- * Note: the specific put_char operation in the driver layer may go
- * away soon. Don't call it directly, use this method
- */
-
-int tty_put_char(struct tty_struct *tty, unsigned char ch)
-{
- if (tty->ops->put_char)
- return tty->ops->put_char(tty, ch);
- return tty->ops->write(tty, &ch, 1);
-}
-EXPORT_SYMBOL_GPL(tty_put_char);
-
-struct class *tty_class;
-
-/**
- * tty_register_device - register a tty device
- * @driver: the tty driver that describes the tty device
- * @index: the index in the tty driver for this tty device
- * @device: a struct device that is associated with this tty device.
- * This field is optional, if there is no known struct device
- * for this tty device it can be set to NULL safely.
- *
- * Returns a pointer to the struct device for this tty device
- * (or ERR_PTR(-EFOO) on error).
- *
- * This call is required to be made to register an individual tty device
- * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
- * that bit is not set, this function should not be called by a tty
- * driver.
- *
- * Locking: ??
- */
-
-struct device *tty_register_device(struct tty_driver *driver, unsigned index,
- struct device *device)
-{
- char name[64];
- dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
-
- if (index >= driver->num) {
- printk(KERN_ERR "Attempt to register invalid tty line number "
- " (%d).\n", index);
- return ERR_PTR(-EINVAL);
- }
-
- if (driver->type == TTY_DRIVER_TYPE_PTY)
- pty_line_name(driver, index, name);
- else
- tty_line_name(driver, index, name);
-
- return device_create(tty_class, device, dev, NULL, name);
-}
-EXPORT_SYMBOL(tty_register_device);
-
-/**
- * tty_unregister_device - unregister a tty device
- * @driver: the tty driver that describes the tty device
- * @index: the index in the tty driver for this tty device
- *
- * If a tty device is registered with a call to tty_register_device() then
- * this function must be called when the tty device is gone.
- *
- * Locking: ??
- */
-
-void tty_unregister_device(struct tty_driver *driver, unsigned index)
-{
- device_destroy(tty_class,
- MKDEV(driver->major, driver->minor_start) + index);
-}
-EXPORT_SYMBOL(tty_unregister_device);
-
-struct tty_driver *alloc_tty_driver(int lines)
-{
- struct tty_driver *driver;
-
- driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL);
- if (driver) {
- kref_init(&driver->kref);
- driver->magic = TTY_DRIVER_MAGIC;
- driver->num = lines;
- /* later we'll move allocation of tables here */
- }
- return driver;
-}
-EXPORT_SYMBOL(alloc_tty_driver);
-
-static void destruct_tty_driver(struct kref *kref)
-{
- struct tty_driver *driver = container_of(kref, struct tty_driver, kref);
- int i;
- struct ktermios *tp;
- void *p;
-
- if (driver->flags & TTY_DRIVER_INSTALLED) {
- /*
- * Free the termios and termios_locked structures because
- * we don't want to get memory leaks when modular tty
- * drivers are removed from the kernel.
- */
- for (i = 0; i < driver->num; i++) {
- tp = driver->termios[i];
- if (tp) {
- driver->termios[i] = NULL;
- kfree(tp);
- }
- if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV))
- tty_unregister_device(driver, i);
- }
- p = driver->ttys;
- proc_tty_unregister_driver(driver);
- driver->ttys = NULL;
- driver->termios = NULL;
- kfree(p);
- cdev_del(&driver->cdev);
- }
- kfree(driver);
-}
-
-void tty_driver_kref_put(struct tty_driver *driver)
-{
- kref_put(&driver->kref, destruct_tty_driver);
-}
-EXPORT_SYMBOL(tty_driver_kref_put);
-
-void tty_set_operations(struct tty_driver *driver,
- const struct tty_operations *op)
-{
- driver->ops = op;
-};
-EXPORT_SYMBOL(tty_set_operations);
-
-void put_tty_driver(struct tty_driver *d)
-{
- tty_driver_kref_put(d);
-}
-EXPORT_SYMBOL(put_tty_driver);
-
-/*
- * Called by a tty driver to register itself.
- */
-int tty_register_driver(struct tty_driver *driver)
-{
- int error;
- int i;
- dev_t dev;
- void **p = NULL;
- struct device *d;
-
- if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
- p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL);
- if (!p)
- return -ENOMEM;
- }
-
- if (!driver->major) {
- error = alloc_chrdev_region(&dev, driver->minor_start,
- driver->num, driver->name);
- if (!error) {
- driver->major = MAJOR(dev);
- driver->minor_start = MINOR(dev);
- }
- } else {
- dev = MKDEV(driver->major, driver->minor_start);
- error = register_chrdev_region(dev, driver->num, driver->name);
- }
- if (error < 0) {
- kfree(p);
- return error;
- }
-
- if (p) {
- driver->ttys = (struct tty_struct **)p;
- driver->termios = (struct ktermios **)(p + driver->num);
- } else {
- driver->ttys = NULL;
- driver->termios = NULL;
- }
-
- cdev_init(&driver->cdev, &tty_fops);
- driver->cdev.owner = driver->owner;
- error = cdev_add(&driver->cdev, dev, driver->num);
- if (error) {
- unregister_chrdev_region(dev, driver->num);
- driver->ttys = NULL;
- driver->termios = NULL;
- kfree(p);
- return error;
- }
-
- mutex_lock(&tty_mutex);
- list_add(&driver->tty_drivers, &tty_drivers);
- mutex_unlock(&tty_mutex);
-
- if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) {
- for (i = 0; i < driver->num; i++) {
- d = tty_register_device(driver, i, NULL);
- if (IS_ERR(d)) {
- error = PTR_ERR(d);
- goto err;
- }
- }
- }
- proc_tty_register_driver(driver);
- driver->flags |= TTY_DRIVER_INSTALLED;
- return 0;
-
-err:
- for (i--; i >= 0; i--)
- tty_unregister_device(driver, i);
-
- mutex_lock(&tty_mutex);
- list_del(&driver->tty_drivers);
- mutex_unlock(&tty_mutex);
-
- unregister_chrdev_region(dev, driver->num);
- driver->ttys = NULL;
- driver->termios = NULL;
- kfree(p);
- return error;
-}
-
-EXPORT_SYMBOL(tty_register_driver);
-
-/*
- * Called by a tty driver to unregister itself.
- */
-int tty_unregister_driver(struct tty_driver *driver)
-{
-#if 0
- /* FIXME */
- if (driver->refcount)
- return -EBUSY;
-#endif
- unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
- driver->num);
- mutex_lock(&tty_mutex);
- list_del(&driver->tty_drivers);
- mutex_unlock(&tty_mutex);
- return 0;
-}
-
-EXPORT_SYMBOL(tty_unregister_driver);
-
-dev_t tty_devnum(struct tty_struct *tty)
-{
- return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
-}
-EXPORT_SYMBOL(tty_devnum);
-
-void proc_clear_tty(struct task_struct *p)
-{
- unsigned long flags;
- struct tty_struct *tty;
- spin_lock_irqsave(&p->sighand->siglock, flags);
- tty = p->signal->tty;
- p->signal->tty = NULL;
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- tty_kref_put(tty);
-}
-
-/* Called under the sighand lock */
-
-static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
-{
- if (tty) {
- unsigned long flags;
- /* We should not have a session or pgrp to put here but.... */
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- put_pid(tty->session);
- put_pid(tty->pgrp);
- tty->pgrp = get_pid(task_pgrp(tsk));
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- tty->session = get_pid(task_session(tsk));
- if (tsk->signal->tty) {
- printk(KERN_DEBUG "tty not NULL!!\n");
- tty_kref_put(tsk->signal->tty);
- }
- }
- put_pid(tsk->signal->tty_old_pgrp);
- tsk->signal->tty = tty_kref_get(tty);
- tsk->signal->tty_old_pgrp = NULL;
-}
-
-static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
-{
- spin_lock_irq(&tsk->sighand->siglock);
- __proc_set_tty(tsk, tty);
- spin_unlock_irq(&tsk->sighand->siglock);
-}
-
-struct tty_struct *get_current_tty(void)
-{
- struct tty_struct *tty;
- unsigned long flags;
-
- spin_lock_irqsave(¤t->sighand->siglock, flags);
- tty = tty_kref_get(current->signal->tty);
- spin_unlock_irqrestore(¤t->sighand->siglock, flags);
- return tty;
-}
-EXPORT_SYMBOL_GPL(get_current_tty);
-
-void tty_default_fops(struct file_operations *fops)
-{
- *fops = tty_fops;
-}
-
-/*
- * Initialize the console device. This is called *early*, so
- * we can't necessarily depend on lots of kernel help here.
- * Just do some early initializations, and do the complex setup
- * later.
- */
-void __init console_init(void)
-{
- initcall_t *call;
-
- /* Setup the default TTY line discipline. */
- tty_ldisc_begin();
-
- /*
- * set up the console device so that later boot sequences can
- * inform about problems etc..
- */
- call = __con_initcall_start;
- while (call < __con_initcall_end) {
- (*call)();
- call++;
- }
-}
-
-static char *tty_devnode(struct device *dev, mode_t *mode)
-{
- if (!mode)
- return NULL;
- if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) ||
- dev->devt == MKDEV(TTYAUX_MAJOR, 2))
- *mode = 0666;
- return NULL;
-}
-
-static int __init tty_class_init(void)
-{
- tty_class = class_create(THIS_MODULE, "tty");
- if (IS_ERR(tty_class))
- return PTR_ERR(tty_class);
- tty_class->devnode = tty_devnode;
- return 0;
-}
-
-postcore_initcall(tty_class_init);
-
-/* 3/2004 jmc: why do these devices exist? */
-
-static struct cdev tty_cdev, console_cdev;
-
-/*
- * Ok, now we can initialize the rest of the tty devices and can count
- * on memory allocations, interrupts etc..
- */
-int __init tty_init(void)
-{
- cdev_init(&tty_cdev, &tty_fops);
- if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
- register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
- panic("Couldn't register /dev/tty driver\n");
- device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
- "tty");
-
- cdev_init(&console_cdev, &console_fops);
- if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
- register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
- panic("Couldn't register /dev/console driver\n");
- device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
- "console");
-
-#ifdef CONFIG_VT
- vty_init(&console_fops);
-#endif
- return 0;
-}
-
+++ /dev/null
-/*
- * linux/drivers/char/tty_ioctl.c
- *
- * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
- *
- * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
- * which can be dynamically activated and de-activated by the line
- * discipline handling modules (like SLIP).
- */
-
-#include <linux/types.h>
-#include <linux/termios.h>
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/major.h>
-#include <linux/tty.h>
-#include <linux/fcntl.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/bitops.h>
-#include <linux/mutex.h>
-
-#include <asm/io.h>
-#include <asm/uaccess.h>
-#include <asm/system.h>
-
-#undef TTY_DEBUG_WAIT_UNTIL_SENT
-
-#undef DEBUG
-
-/*
- * Internal flag options for termios setting behavior
- */
-#define TERMIOS_FLUSH 1
-#define TERMIOS_WAIT 2
-#define TERMIOS_TERMIO 4
-#define TERMIOS_OLD 8
-
-
-/**
- * tty_chars_in_buffer - characters pending
- * @tty: terminal
- *
- * Return the number of bytes of data in the device private
- * output queue. If no private method is supplied there is assumed
- * to be no queue on the device.
- */
-
-int tty_chars_in_buffer(struct tty_struct *tty)
-{
- if (tty->ops->chars_in_buffer)
- return tty->ops->chars_in_buffer(tty);
- else
- return 0;
-}
-EXPORT_SYMBOL(tty_chars_in_buffer);
-
-/**
- * tty_write_room - write queue space
- * @tty: terminal
- *
- * Return the number of bytes that can be queued to this device
- * at the present time. The result should be treated as a guarantee
- * and the driver cannot offer a value it later shrinks by more than
- * the number of bytes written. If no method is provided 2K is always
- * returned and data may be lost as there will be no flow control.
- */
-
-int tty_write_room(struct tty_struct *tty)
-{
- if (tty->ops->write_room)
- return tty->ops->write_room(tty);
- return 2048;
-}
-EXPORT_SYMBOL(tty_write_room);
-
-/**
- * tty_driver_flush_buffer - discard internal buffer
- * @tty: terminal
- *
- * Discard the internal output buffer for this device. If no method
- * is provided then either the buffer cannot be hardware flushed or
- * there is no buffer driver side.
- */
-void tty_driver_flush_buffer(struct tty_struct *tty)
-{
- if (tty->ops->flush_buffer)
- tty->ops->flush_buffer(tty);
-}
-EXPORT_SYMBOL(tty_driver_flush_buffer);
-
-/**
- * tty_throttle - flow control
- * @tty: terminal
- *
- * Indicate that a tty should stop transmitting data down the stack.
- * Takes the termios mutex to protect against parallel throttle/unthrottle
- * and also to ensure the driver can consistently reference its own
- * termios data at this point when implementing software flow control.
- */
-
-void tty_throttle(struct tty_struct *tty)
-{
- mutex_lock(&tty->termios_mutex);
- /* check TTY_THROTTLED first so it indicates our state */
- if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
- tty->ops->throttle)
- tty->ops->throttle(tty);
- mutex_unlock(&tty->termios_mutex);
-}
-EXPORT_SYMBOL(tty_throttle);
-
-/**
- * tty_unthrottle - flow control
- * @tty: terminal
- *
- * Indicate that a tty may continue transmitting data down the stack.
- * Takes the termios mutex to protect against parallel throttle/unthrottle
- * and also to ensure the driver can consistently reference its own
- * termios data at this point when implementing software flow control.
- *
- * Drivers should however remember that the stack can issue a throttle,
- * then change flow control method, then unthrottle.
- */
-
-void tty_unthrottle(struct tty_struct *tty)
-{
- mutex_lock(&tty->termios_mutex);
- if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
- tty->ops->unthrottle)
- tty->ops->unthrottle(tty);
- mutex_unlock(&tty->termios_mutex);
-}
-EXPORT_SYMBOL(tty_unthrottle);
-
-/**
- * tty_wait_until_sent - wait for I/O to finish
- * @tty: tty we are waiting for
- * @timeout: how long we will wait
- *
- * Wait for characters pending in a tty driver to hit the wire, or
- * for a timeout to occur (eg due to flow control)
- *
- * Locking: none
- */
-
-void tty_wait_until_sent(struct tty_struct *tty, long timeout)
-{
-#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
- char buf[64];
-
- printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
-#endif
- if (!timeout)
- timeout = MAX_SCHEDULE_TIMEOUT;
- if (wait_event_interruptible_timeout(tty->write_wait,
- !tty_chars_in_buffer(tty), timeout) >= 0) {
- if (tty->ops->wait_until_sent)
- tty->ops->wait_until_sent(tty, timeout);
- }
-}
-EXPORT_SYMBOL(tty_wait_until_sent);
-
-
-/*
- * Termios Helper Methods
- */
-
-static void unset_locked_termios(struct ktermios *termios,
- struct ktermios *old,
- struct ktermios *locked)
-{
- int i;
-
-#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
-
- if (!locked) {
- printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
- return;
- }
-
- NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
- NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
- NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
- NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
- termios->c_line = locked->c_line ? old->c_line : termios->c_line;
- for (i = 0; i < NCCS; i++)
- termios->c_cc[i] = locked->c_cc[i] ?
- old->c_cc[i] : termios->c_cc[i];
- /* FIXME: What should we do for i/ospeed */
-}
-
-/*
- * Routine which returns the baud rate of the tty
- *
- * Note that the baud_table needs to be kept in sync with the
- * include/asm/termbits.h file.
- */
-static const speed_t baud_table[] = {
- 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
- 9600, 19200, 38400, 57600, 115200, 230400, 460800,
-#ifdef __sparc__
- 76800, 153600, 307200, 614400, 921600
-#else
- 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
- 2500000, 3000000, 3500000, 4000000
-#endif
-};
-
-#ifndef __sparc__
-static const tcflag_t baud_bits[] = {
- B0, B50, B75, B110, B134, B150, B200, B300, B600,
- B1200, B1800, B2400, B4800, B9600, B19200, B38400,
- B57600, B115200, B230400, B460800, B500000, B576000,
- B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
- B3000000, B3500000, B4000000
-};
-#else
-static const tcflag_t baud_bits[] = {
- B0, B50, B75, B110, B134, B150, B200, B300, B600,
- B1200, B1800, B2400, B4800, B9600, B19200, B38400,
- B57600, B115200, B230400, B460800, B76800, B153600,
- B307200, B614400, B921600
-};
-#endif
-
-static int n_baud_table = ARRAY_SIZE(baud_table);
-
-/**
- * tty_termios_baud_rate
- * @termios: termios structure
- *
- * Convert termios baud rate data into a speed. This should be called
- * with the termios lock held if this termios is a terminal termios
- * structure. May change the termios data. Device drivers can call this
- * function but should use ->c_[io]speed directly as they are updated.
- *
- * Locking: none
- */
-
-speed_t tty_termios_baud_rate(struct ktermios *termios)
-{
- unsigned int cbaud;
-
- cbaud = termios->c_cflag & CBAUD;
-
-#ifdef BOTHER
- /* Magic token for arbitary speed via c_ispeed/c_ospeed */
- if (cbaud == BOTHER)
- return termios->c_ospeed;
-#endif
- if (cbaud & CBAUDEX) {
- cbaud &= ~CBAUDEX;
-
- if (cbaud < 1 || cbaud + 15 > n_baud_table)
- termios->c_cflag &= ~CBAUDEX;
- else
- cbaud += 15;
- }
- return baud_table[cbaud];
-}
-EXPORT_SYMBOL(tty_termios_baud_rate);
-
-/**
- * tty_termios_input_baud_rate
- * @termios: termios structure
- *
- * Convert termios baud rate data into a speed. This should be called
- * with the termios lock held if this termios is a terminal termios
- * structure. May change the termios data. Device drivers can call this
- * function but should use ->c_[io]speed directly as they are updated.
- *
- * Locking: none
- */
-
-speed_t tty_termios_input_baud_rate(struct ktermios *termios)
-{
-#ifdef IBSHIFT
- unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
-
- if (cbaud == B0)
- return tty_termios_baud_rate(termios);
-
- /* Magic token for arbitary speed via c_ispeed*/
- if (cbaud == BOTHER)
- return termios->c_ispeed;
-
- if (cbaud & CBAUDEX) {
- cbaud &= ~CBAUDEX;
-
- if (cbaud < 1 || cbaud + 15 > n_baud_table)
- termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
- else
- cbaud += 15;
- }
- return baud_table[cbaud];
-#else
- return tty_termios_baud_rate(termios);
-#endif
-}
-EXPORT_SYMBOL(tty_termios_input_baud_rate);
-
-/**
- * tty_termios_encode_baud_rate
- * @termios: ktermios structure holding user requested state
- * @ispeed: input speed
- * @ospeed: output speed
- *
- * Encode the speeds set into the passed termios structure. This is
- * used as a library helper for drivers os that they can report back
- * the actual speed selected when it differs from the speed requested
- *
- * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
- * we need to carefully set the bits when the user does not get the
- * desired speed. We allow small margins and preserve as much of possible
- * of the input intent to keep compatibility.
- *
- * Locking: Caller should hold termios lock. This is already held
- * when calling this function from the driver termios handler.
- *
- * The ifdefs deal with platforms whose owners have yet to update them
- * and will all go away once this is done.
- */
-
-void tty_termios_encode_baud_rate(struct ktermios *termios,
- speed_t ibaud, speed_t obaud)
-{
- int i = 0;
- int ifound = -1, ofound = -1;
- int iclose = ibaud/50, oclose = obaud/50;
- int ibinput = 0;
-
- if (obaud == 0) /* CD dropped */
- ibaud = 0; /* Clear ibaud to be sure */
-
- termios->c_ispeed = ibaud;
- termios->c_ospeed = obaud;
-
-#ifdef BOTHER
- /* If the user asked for a precise weird speed give a precise weird
- answer. If they asked for a Bfoo speed they many have problems
- digesting non-exact replies so fuzz a bit */
-
- if ((termios->c_cflag & CBAUD) == BOTHER)
- oclose = 0;
- if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
- iclose = 0;
- if ((termios->c_cflag >> IBSHIFT) & CBAUD)
- ibinput = 1; /* An input speed was specified */
-#endif
- termios->c_cflag &= ~CBAUD;
-
- /*
- * Our goal is to find a close match to the standard baud rate
- * returned. Walk the baud rate table and if we get a very close
- * match then report back the speed as a POSIX Bxxxx value by
- * preference
- */
-
- do {
- if (obaud - oclose <= baud_table[i] &&
- obaud + oclose >= baud_table[i]) {
- termios->c_cflag |= baud_bits[i];
- ofound = i;
- }
- if (ibaud - iclose <= baud_table[i] &&
- ibaud + iclose >= baud_table[i]) {
- /* For the case input == output don't set IBAUD bits
- if the user didn't do so */
- if (ofound == i && !ibinput)
- ifound = i;
-#ifdef IBSHIFT
- else {
- ifound = i;
- termios->c_cflag |= (baud_bits[i] << IBSHIFT);
- }
-#endif
- }
- } while (++i < n_baud_table);
-
- /*
- * If we found no match then use BOTHER if provided or warn
- * the user their platform maintainer needs to wake up if not.
- */
-#ifdef BOTHER
- if (ofound == -1)
- termios->c_cflag |= BOTHER;
- /* Set exact input bits only if the input and output differ or the
- user already did */
- if (ifound == -1 && (ibaud != obaud || ibinput))
- termios->c_cflag |= (BOTHER << IBSHIFT);
-#else
- if (ifound == -1 || ofound == -1) {
- printk_once(KERN_WARNING "tty: Unable to return correct "
- "speed data as your architecture needs updating.\n");
- }
-#endif
-}
-EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
-
-/**
- * tty_encode_baud_rate - set baud rate of the tty
- * @ibaud: input baud rate
- * @obad: output baud rate
- *
- * Update the current termios data for the tty with the new speed
- * settings. The caller must hold the termios_mutex for the tty in
- * question.
- */
-
-void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
-{
- tty_termios_encode_baud_rate(tty->termios, ibaud, obaud);
-}
-EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
-
-/**
- * tty_get_baud_rate - get tty bit rates
- * @tty: tty to query
- *
- * Returns the baud rate as an integer for this terminal. The
- * termios lock must be held by the caller and the terminal bit
- * flags may be updated.
- *
- * Locking: none
- */
-
-speed_t tty_get_baud_rate(struct tty_struct *tty)
-{
- speed_t baud = tty_termios_baud_rate(tty->termios);
-
- if (baud == 38400 && tty->alt_speed) {
- if (!tty->warned) {
- printk(KERN_WARNING "Use of setserial/setrocket to "
- "set SPD_* flags is deprecated\n");
- tty->warned = 1;
- }
- baud = tty->alt_speed;
- }
-
- return baud;
-}
-EXPORT_SYMBOL(tty_get_baud_rate);
-
-/**
- * tty_termios_copy_hw - copy hardware settings
- * @new: New termios
- * @old: Old termios
- *
- * Propogate the hardware specific terminal setting bits from
- * the old termios structure to the new one. This is used in cases
- * where the hardware does not support reconfiguration or as a helper
- * in some cases where only minimal reconfiguration is supported
- */
-
-void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
-{
- /* The bits a dumb device handles in software. Smart devices need
- to always provide a set_termios method */
- new->c_cflag &= HUPCL | CREAD | CLOCAL;
- new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
- new->c_ispeed = old->c_ispeed;
- new->c_ospeed = old->c_ospeed;
-}
-EXPORT_SYMBOL(tty_termios_copy_hw);
-
-/**
- * tty_termios_hw_change - check for setting change
- * @a: termios
- * @b: termios to compare
- *
- * Check if any of the bits that affect a dumb device have changed
- * between the two termios structures, or a speed change is needed.
- */
-
-int tty_termios_hw_change(struct ktermios *a, struct ktermios *b)
-{
- if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
- return 1;
- if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
- return 1;
- return 0;
-}
-EXPORT_SYMBOL(tty_termios_hw_change);
-
-/**
- * change_termios - update termios values
- * @tty: tty to update
- * @new_termios: desired new value
- *
- * Perform updates to the termios values set on this terminal. There
- * is a bit of layering violation here with n_tty in terms of the
- * internal knowledge of this function.
- *
- * Locking: termios_mutex
- */
-
-static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
-{
- struct ktermios old_termios;
- struct tty_ldisc *ld;
- unsigned long flags;
-
- /*
- * Perform the actual termios internal changes under lock.
- */
-
-
- /* FIXME: we need to decide on some locking/ordering semantics
- for the set_termios notification eventually */
- mutex_lock(&tty->termios_mutex);
- old_termios = *tty->termios;
- *tty->termios = *new_termios;
- unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
-
- /* See if packet mode change of state. */
- if (tty->link && tty->link->packet) {
- int extproc = (old_termios.c_lflag & EXTPROC) |
- (tty->termios->c_lflag & EXTPROC);
- int old_flow = ((old_termios.c_iflag & IXON) &&
- (old_termios.c_cc[VSTOP] == '\023') &&
- (old_termios.c_cc[VSTART] == '\021'));
- int new_flow = (I_IXON(tty) &&
- STOP_CHAR(tty) == '\023' &&
- START_CHAR(tty) == '\021');
- if ((old_flow != new_flow) || extproc) {
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- if (old_flow != new_flow) {
- tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
- if (new_flow)
- tty->ctrl_status |= TIOCPKT_DOSTOP;
- else
- tty->ctrl_status |= TIOCPKT_NOSTOP;
- }
- if (extproc)
- tty->ctrl_status |= TIOCPKT_IOCTL;
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- wake_up_interruptible(&tty->link->read_wait);
- }
- }
-
- if (tty->ops->set_termios)
- (*tty->ops->set_termios)(tty, &old_termios);
- else
- tty_termios_copy_hw(tty->termios, &old_termios);
-
- ld = tty_ldisc_ref(tty);
- if (ld != NULL) {
- if (ld->ops->set_termios)
- (ld->ops->set_termios)(tty, &old_termios);
- tty_ldisc_deref(ld);
- }
- mutex_unlock(&tty->termios_mutex);
-}
-
-/**
- * set_termios - set termios values for a tty
- * @tty: terminal device
- * @arg: user data
- * @opt: option information
- *
- * Helper function to prepare termios data and run necessary other
- * functions before using change_termios to do the actual changes.
- *
- * Locking:
- * Called functions take ldisc and termios_mutex locks
- */
-
-static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
-{
- struct ktermios tmp_termios;
- struct tty_ldisc *ld;
- int retval = tty_check_change(tty);
-
- if (retval)
- return retval;
-
- mutex_lock(&tty->termios_mutex);
- memcpy(&tmp_termios, tty->termios, sizeof(struct ktermios));
- mutex_unlock(&tty->termios_mutex);
-
- if (opt & TERMIOS_TERMIO) {
- if (user_termio_to_kernel_termios(&tmp_termios,
- (struct termio __user *)arg))
- return -EFAULT;
-#ifdef TCGETS2
- } else if (opt & TERMIOS_OLD) {
- if (user_termios_to_kernel_termios_1(&tmp_termios,
- (struct termios __user *)arg))
- return -EFAULT;
- } else {
- if (user_termios_to_kernel_termios(&tmp_termios,
- (struct termios2 __user *)arg))
- return -EFAULT;
- }
-#else
- } else if (user_termios_to_kernel_termios(&tmp_termios,
- (struct termios __user *)arg))
- return -EFAULT;
-#endif
-
- /* If old style Bfoo values are used then load c_ispeed/c_ospeed
- * with the real speed so its unconditionally usable */
- tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
- tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
-
- ld = tty_ldisc_ref(tty);
-
- if (ld != NULL) {
- if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
- ld->ops->flush_buffer(tty);
- tty_ldisc_deref(ld);
- }
-
- if (opt & TERMIOS_WAIT) {
- tty_wait_until_sent(tty, 0);
- if (signal_pending(current))
- return -EINTR;
- }
-
- change_termios(tty, &tmp_termios);
-
- /* FIXME: Arguably if tmp_termios == tty->termios AND the
- actual requested termios was not tmp_termios then we may
- want to return an error as no user requested change has
- succeeded */
- return 0;
-}
-
-static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
-{
- mutex_lock(&tty->termios_mutex);
- memcpy(kterm, tty->termios, sizeof(struct ktermios));
- mutex_unlock(&tty->termios_mutex);
-}
-
-static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
-{
- mutex_lock(&tty->termios_mutex);
- memcpy(kterm, tty->termios_locked, sizeof(struct ktermios));
- mutex_unlock(&tty->termios_mutex);
-}
-
-static int get_termio(struct tty_struct *tty, struct termio __user *termio)
-{
- struct ktermios kterm;
- copy_termios(tty, &kterm);
- if (kernel_termios_to_user_termio(termio, &kterm))
- return -EFAULT;
- return 0;
-}
-
-
-#ifdef TCGETX
-
-/**
- * set_termiox - set termiox fields if possible
- * @tty: terminal
- * @arg: termiox structure from user
- * @opt: option flags for ioctl type
- *
- * Implement the device calling points for the SYS5 termiox ioctl
- * interface in Linux
- */
-
-static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
-{
- struct termiox tnew;
- struct tty_ldisc *ld;
-
- if (tty->termiox == NULL)
- return -EINVAL;
- if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
- return -EFAULT;
-
- ld = tty_ldisc_ref(tty);
- if (ld != NULL) {
- if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
- ld->ops->flush_buffer(tty);
- tty_ldisc_deref(ld);
- }
- if (opt & TERMIOS_WAIT) {
- tty_wait_until_sent(tty, 0);
- if (signal_pending(current))
- return -EINTR;
- }
-
- mutex_lock(&tty->termios_mutex);
- if (tty->ops->set_termiox)
- tty->ops->set_termiox(tty, &tnew);
- mutex_unlock(&tty->termios_mutex);
- return 0;
-}
-
-#endif
-
-
-#ifdef TIOCGETP
-/*
- * These are deprecated, but there is limited support..
- *
- * The "sg_flags" translation is a joke..
- */
-static int get_sgflags(struct tty_struct *tty)
-{
- int flags = 0;
-
- if (!(tty->termios->c_lflag & ICANON)) {
- if (tty->termios->c_lflag & ISIG)
- flags |= 0x02; /* cbreak */
- else
- flags |= 0x20; /* raw */
- }
- if (tty->termios->c_lflag & ECHO)
- flags |= 0x08; /* echo */
- if (tty->termios->c_oflag & OPOST)
- if (tty->termios->c_oflag & ONLCR)
- flags |= 0x10; /* crmod */
- return flags;
-}
-
-static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
-{
- struct sgttyb tmp;
-
- mutex_lock(&tty->termios_mutex);
- tmp.sg_ispeed = tty->termios->c_ispeed;
- tmp.sg_ospeed = tty->termios->c_ospeed;
- tmp.sg_erase = tty->termios->c_cc[VERASE];
- tmp.sg_kill = tty->termios->c_cc[VKILL];
- tmp.sg_flags = get_sgflags(tty);
- mutex_unlock(&tty->termios_mutex);
-
- return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
-}
-
-static void set_sgflags(struct ktermios *termios, int flags)
-{
- termios->c_iflag = ICRNL | IXON;
- termios->c_oflag = 0;
- termios->c_lflag = ISIG | ICANON;
- if (flags & 0x02) { /* cbreak */
- termios->c_iflag = 0;
- termios->c_lflag &= ~ICANON;
- }
- if (flags & 0x08) { /* echo */
- termios->c_lflag |= ECHO | ECHOE | ECHOK |
- ECHOCTL | ECHOKE | IEXTEN;
- }
- if (flags & 0x10) { /* crmod */
- termios->c_oflag |= OPOST | ONLCR;
- }
- if (flags & 0x20) { /* raw */
- termios->c_iflag = 0;
- termios->c_lflag &= ~(ISIG | ICANON);
- }
- if (!(termios->c_lflag & ICANON)) {
- termios->c_cc[VMIN] = 1;
- termios->c_cc[VTIME] = 0;
- }
-}
-
-/**
- * set_sgttyb - set legacy terminal values
- * @tty: tty structure
- * @sgttyb: pointer to old style terminal structure
- *
- * Updates a terminal from the legacy BSD style terminal information
- * structure.
- *
- * Locking: termios_mutex
- */
-
-static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
-{
- int retval;
- struct sgttyb tmp;
- struct ktermios termios;
-
- retval = tty_check_change(tty);
- if (retval)
- return retval;
-
- if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
- return -EFAULT;
-
- mutex_lock(&tty->termios_mutex);
- termios = *tty->termios;
- termios.c_cc[VERASE] = tmp.sg_erase;
- termios.c_cc[VKILL] = tmp.sg_kill;
- set_sgflags(&termios, tmp.sg_flags);
- /* Try and encode into Bfoo format */
-#ifdef BOTHER
- tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
- termios.c_ospeed);
-#endif
- mutex_unlock(&tty->termios_mutex);
- change_termios(tty, &termios);
- return 0;
-}
-#endif
-
-#ifdef TIOCGETC
-static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
-{
- struct tchars tmp;
-
- mutex_lock(&tty->termios_mutex);
- tmp.t_intrc = tty->termios->c_cc[VINTR];
- tmp.t_quitc = tty->termios->c_cc[VQUIT];
- tmp.t_startc = tty->termios->c_cc[VSTART];
- tmp.t_stopc = tty->termios->c_cc[VSTOP];
- tmp.t_eofc = tty->termios->c_cc[VEOF];
- tmp.t_brkc = tty->termios->c_cc[VEOL2]; /* what is brkc anyway? */
- mutex_unlock(&tty->termios_mutex);
- return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
-}
-
-static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
-{
- struct tchars tmp;
-
- if (copy_from_user(&tmp, tchars, sizeof(tmp)))
- return -EFAULT;
- mutex_lock(&tty->termios_mutex);
- tty->termios->c_cc[VINTR] = tmp.t_intrc;
- tty->termios->c_cc[VQUIT] = tmp.t_quitc;
- tty->termios->c_cc[VSTART] = tmp.t_startc;
- tty->termios->c_cc[VSTOP] = tmp.t_stopc;
- tty->termios->c_cc[VEOF] = tmp.t_eofc;
- tty->termios->c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
- mutex_unlock(&tty->termios_mutex);
- return 0;
-}
-#endif
-
-#ifdef TIOCGLTC
-static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
-{
- struct ltchars tmp;
-
- mutex_lock(&tty->termios_mutex);
- tmp.t_suspc = tty->termios->c_cc[VSUSP];
- /* what is dsuspc anyway? */
- tmp.t_dsuspc = tty->termios->c_cc[VSUSP];
- tmp.t_rprntc = tty->termios->c_cc[VREPRINT];
- /* what is flushc anyway? */
- tmp.t_flushc = tty->termios->c_cc[VEOL2];
- tmp.t_werasc = tty->termios->c_cc[VWERASE];
- tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
- mutex_unlock(&tty->termios_mutex);
- return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
-}
-
-static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
-{
- struct ltchars tmp;
-
- if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
- return -EFAULT;
-
- mutex_lock(&tty->termios_mutex);
- tty->termios->c_cc[VSUSP] = tmp.t_suspc;
- /* what is dsuspc anyway? */
- tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;
- tty->termios->c_cc[VREPRINT] = tmp.t_rprntc;
- /* what is flushc anyway? */
- tty->termios->c_cc[VEOL2] = tmp.t_flushc;
- tty->termios->c_cc[VWERASE] = tmp.t_werasc;
- tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
- mutex_unlock(&tty->termios_mutex);
- return 0;
-}
-#endif
-
-/**
- * send_prio_char - send priority character
- *
- * Send a high priority character to the tty even if stopped
- *
- * Locking: none for xchar method, write ordering for write method.
- */
-
-static int send_prio_char(struct tty_struct *tty, char ch)
-{
- int was_stopped = tty->stopped;
-
- if (tty->ops->send_xchar) {
- tty->ops->send_xchar(tty, ch);
- return 0;
- }
-
- if (tty_write_lock(tty, 0) < 0)
- return -ERESTARTSYS;
-
- if (was_stopped)
- start_tty(tty);
- tty->ops->write(tty, &ch, 1);
- if (was_stopped)
- stop_tty(tty);
- tty_write_unlock(tty);
- return 0;
-}
-
-/**
- * tty_change_softcar - carrier change ioctl helper
- * @tty: tty to update
- * @arg: enable/disable CLOCAL
- *
- * Perform a change to the CLOCAL state and call into the driver
- * layer to make it visible. All done with the termios mutex
- */
-
-static int tty_change_softcar(struct tty_struct *tty, int arg)
-{
- int ret = 0;
- int bit = arg ? CLOCAL : 0;
- struct ktermios old;
-
- mutex_lock(&tty->termios_mutex);
- old = *tty->termios;
- tty->termios->c_cflag &= ~CLOCAL;
- tty->termios->c_cflag |= bit;
- if (tty->ops->set_termios)
- tty->ops->set_termios(tty, &old);
- if ((tty->termios->c_cflag & CLOCAL) != bit)
- ret = -EINVAL;
- mutex_unlock(&tty->termios_mutex);
- return ret;
-}
-
-/**
- * tty_mode_ioctl - mode related ioctls
- * @tty: tty for the ioctl
- * @file: file pointer for the tty
- * @cmd: command
- * @arg: ioctl argument
- *
- * Perform non line discipline specific mode control ioctls. This
- * is designed to be called by line disciplines to ensure they provide
- * consistent mode setting.
- */
-
-int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- struct tty_struct *real_tty;
- void __user *p = (void __user *)arg;
- int ret = 0;
- struct ktermios kterm;
-
- if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
- tty->driver->subtype == PTY_TYPE_MASTER)
- real_tty = tty->link;
- else
- real_tty = tty;
-
- switch (cmd) {
-#ifdef TIOCGETP
- case TIOCGETP:
- return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
- case TIOCSETP:
- case TIOCSETN:
- return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
-#endif
-#ifdef TIOCGETC
- case TIOCGETC:
- return get_tchars(real_tty, p);
- case TIOCSETC:
- return set_tchars(real_tty, p);
-#endif
-#ifdef TIOCGLTC
- case TIOCGLTC:
- return get_ltchars(real_tty, p);
- case TIOCSLTC:
- return set_ltchars(real_tty, p);
-#endif
- case TCSETSF:
- return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
- case TCSETSW:
- return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
- case TCSETS:
- return set_termios(real_tty, p, TERMIOS_OLD);
-#ifndef TCGETS2
- case TCGETS:
- copy_termios(real_tty, &kterm);
- if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
- ret = -EFAULT;
- return ret;
-#else
- case TCGETS:
- copy_termios(real_tty, &kterm);
- if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
- ret = -EFAULT;
- return ret;
- case TCGETS2:
- copy_termios(real_tty, &kterm);
- if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
- ret = -EFAULT;
- return ret;
- case TCSETSF2:
- return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
- case TCSETSW2:
- return set_termios(real_tty, p, TERMIOS_WAIT);
- case TCSETS2:
- return set_termios(real_tty, p, 0);
-#endif
- case TCGETA:
- return get_termio(real_tty, p);
- case TCSETAF:
- return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
- case TCSETAW:
- return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
- case TCSETA:
- return set_termios(real_tty, p, TERMIOS_TERMIO);
-#ifndef TCGETS2
- case TIOCGLCKTRMIOS:
- copy_termios_locked(real_tty, &kterm);
- if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
- ret = -EFAULT;
- return ret;
- case TIOCSLCKTRMIOS:
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- copy_termios_locked(real_tty, &kterm);
- if (user_termios_to_kernel_termios(&kterm,
- (struct termios __user *) arg))
- return -EFAULT;
- mutex_lock(&real_tty->termios_mutex);
- memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
- mutex_unlock(&real_tty->termios_mutex);
- return 0;
-#else
- case TIOCGLCKTRMIOS:
- copy_termios_locked(real_tty, &kterm);
- if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
- ret = -EFAULT;
- return ret;
- case TIOCSLCKTRMIOS:
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
- copy_termios_locked(real_tty, &kterm);
- if (user_termios_to_kernel_termios_1(&kterm,
- (struct termios __user *) arg))
- return -EFAULT;
- mutex_lock(&real_tty->termios_mutex);
- memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
- mutex_unlock(&real_tty->termios_mutex);
- return ret;
-#endif
-#ifdef TCGETX
- case TCGETX: {
- struct termiox ktermx;
- if (real_tty->termiox == NULL)
- return -EINVAL;
- mutex_lock(&real_tty->termios_mutex);
- memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
- mutex_unlock(&real_tty->termios_mutex);
- if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
- ret = -EFAULT;
- return ret;
- }
- case TCSETX:
- return set_termiox(real_tty, p, 0);
- case TCSETXW:
- return set_termiox(real_tty, p, TERMIOS_WAIT);
- case TCSETXF:
- return set_termiox(real_tty, p, TERMIOS_FLUSH);
-#endif
- case TIOCGSOFTCAR:
- copy_termios(real_tty, &kterm);
- ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
- (int __user *)arg);
- return ret;
- case TIOCSSOFTCAR:
- if (get_user(arg, (unsigned int __user *) arg))
- return -EFAULT;
- return tty_change_softcar(real_tty, arg);
- default:
- return -ENOIOCTLCMD;
- }
-}
-EXPORT_SYMBOL_GPL(tty_mode_ioctl);
-
-int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
-{
- struct tty_ldisc *ld;
- int retval = tty_check_change(tty);
- if (retval)
- return retval;
-
- ld = tty_ldisc_ref_wait(tty);
- switch (arg) {
- case TCIFLUSH:
- if (ld && ld->ops->flush_buffer)
- ld->ops->flush_buffer(tty);
- break;
- case TCIOFLUSH:
- if (ld && ld->ops->flush_buffer)
- ld->ops->flush_buffer(tty);
- /* fall through */
- case TCOFLUSH:
- tty_driver_flush_buffer(tty);
- break;
- default:
- tty_ldisc_deref(ld);
- return -EINVAL;
- }
- tty_ldisc_deref(ld);
- return 0;
-}
-EXPORT_SYMBOL_GPL(tty_perform_flush);
-
-int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- unsigned long flags;
- int retval;
-
- switch (cmd) {
- case TCXONC:
- retval = tty_check_change(tty);
- if (retval)
- return retval;
- switch (arg) {
- case TCOOFF:
- if (!tty->flow_stopped) {
- tty->flow_stopped = 1;
- stop_tty(tty);
- }
- break;
- case TCOON:
- if (tty->flow_stopped) {
- tty->flow_stopped = 0;
- start_tty(tty);
- }
- break;
- case TCIOFF:
- if (STOP_CHAR(tty) != __DISABLED_CHAR)
- return send_prio_char(tty, STOP_CHAR(tty));
- break;
- case TCION:
- if (START_CHAR(tty) != __DISABLED_CHAR)
- return send_prio_char(tty, START_CHAR(tty));
- break;
- default:
- return -EINVAL;
- }
- return 0;
- case TCFLSH:
- return tty_perform_flush(tty, arg);
- case TIOCPKT:
- {
- int pktmode;
-
- if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
- tty->driver->subtype != PTY_TYPE_MASTER)
- return -ENOTTY;
- if (get_user(pktmode, (int __user *) arg))
- return -EFAULT;
- spin_lock_irqsave(&tty->ctrl_lock, flags);
- if (pktmode) {
- if (!tty->packet) {
- tty->packet = 1;
- tty->link->ctrl_status = 0;
- }
- } else
- tty->packet = 0;
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
- return 0;
- }
- default:
- /* Try the mode commands */
- return tty_mode_ioctl(tty, file, cmd, arg);
- }
-}
-EXPORT_SYMBOL(n_tty_ioctl_helper);
+++ /dev/null
-#include <linux/types.h>
-#include <linux/major.h>
-#include <linux/errno.h>
-#include <linux/signal.h>
-#include <linux/fcntl.h>
-#include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/tty.h>
-#include <linux/tty_driver.h>
-#include <linux/tty_flip.h>
-#include <linux/devpts_fs.h>
-#include <linux/file.h>
-#include <linux/console.h>
-#include <linux/timer.h>
-#include <linux/ctype.h>
-#include <linux/kd.h>
-#include <linux/mm.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/poll.h>
-#include <linux/proc_fs.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/wait.h>
-#include <linux/bitops.h>
-#include <linux/delay.h>
-#include <linux/seq_file.h>
-
-#include <linux/uaccess.h>
-#include <asm/system.h>
-
-#include <linux/kbd_kern.h>
-#include <linux/vt_kern.h>
-#include <linux/selection.h>
-
-#include <linux/smp_lock.h> /* For the moment */
-
-#include <linux/kmod.h>
-#include <linux/nsproxy.h>
-
-/*
- * This guards the refcounted line discipline lists. The lock
- * must be taken with irqs off because there are hangup path
- * callers who will do ldisc lookups and cannot sleep.
- */
-
-static DEFINE_SPINLOCK(tty_ldisc_lock);
-static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
-/* Line disc dispatch table */
-static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
-
-static inline struct tty_ldisc *get_ldisc(struct tty_ldisc *ld)
-{
- if (ld)
- atomic_inc(&ld->users);
- return ld;
-}
-
-static void put_ldisc(struct tty_ldisc *ld)
-{
- unsigned long flags;
-
- if (WARN_ON_ONCE(!ld))
- return;
-
- /*
- * If this is the last user, free the ldisc, and
- * release the ldisc ops.
- *
- * We really want an "atomic_dec_and_lock_irqsave()",
- * but we don't have it, so this does it by hand.
- */
- local_irq_save(flags);
- if (atomic_dec_and_lock(&ld->users, &tty_ldisc_lock)) {
- struct tty_ldisc_ops *ldo = ld->ops;
-
- ldo->refcount--;
- module_put(ldo->owner);
- spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-
- kfree(ld);
- return;
- }
- local_irq_restore(flags);
-}
-
-/**
- * tty_register_ldisc - install a line discipline
- * @disc: ldisc number
- * @new_ldisc: pointer to the ldisc object
- *
- * Installs a new line discipline into the kernel. The discipline
- * is set up as unreferenced and then made available to the kernel
- * from this point onwards.
- *
- * Locking:
- * takes tty_ldisc_lock to guard against ldisc races
- */
-
-int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc)
-{
- unsigned long flags;
- int ret = 0;
-
- if (disc < N_TTY || disc >= NR_LDISCS)
- return -EINVAL;
-
- spin_lock_irqsave(&tty_ldisc_lock, flags);
- tty_ldiscs[disc] = new_ldisc;
- new_ldisc->num = disc;
- new_ldisc->refcount = 0;
- spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-
- return ret;
-}
-EXPORT_SYMBOL(tty_register_ldisc);
-
-/**
- * tty_unregister_ldisc - unload a line discipline
- * @disc: ldisc number
- * @new_ldisc: pointer to the ldisc object
- *
- * Remove a line discipline from the kernel providing it is not
- * currently in use.
- *
- * Locking:
- * takes tty_ldisc_lock to guard against ldisc races
- */
-
-int tty_unregister_ldisc(int disc)
-{
- unsigned long flags;
- int ret = 0;
-
- if (disc < N_TTY || disc >= NR_LDISCS)
- return -EINVAL;
-
- spin_lock_irqsave(&tty_ldisc_lock, flags);
- if (tty_ldiscs[disc]->refcount)
- ret = -EBUSY;
- else
- tty_ldiscs[disc] = NULL;
- spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-
- return ret;
-}
-EXPORT_SYMBOL(tty_unregister_ldisc);
-
-static struct tty_ldisc_ops *get_ldops(int disc)
-{
- unsigned long flags;
- struct tty_ldisc_ops *ldops, *ret;
-
- spin_lock_irqsave(&tty_ldisc_lock, flags);
- ret = ERR_PTR(-EINVAL);
- ldops = tty_ldiscs[disc];
- if (ldops) {
- ret = ERR_PTR(-EAGAIN);
- if (try_module_get(ldops->owner)) {
- ldops->refcount++;
- ret = ldops;
- }
- }
- spin_unlock_irqrestore(&tty_ldisc_lock, flags);
- return ret;
-}
-
-static void put_ldops(struct tty_ldisc_ops *ldops)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&tty_ldisc_lock, flags);
- ldops->refcount--;
- module_put(ldops->owner);
- spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-}
-
-/**
- * tty_ldisc_get - take a reference to an ldisc
- * @disc: ldisc number
- *
- * Takes a reference to a line discipline. Deals with refcounts and
- * module locking counts. Returns NULL if the discipline is not available.
- * Returns a pointer to the discipline and bumps the ref count if it is
- * available
- *
- * Locking:
- * takes tty_ldisc_lock to guard against ldisc races
- */
-
-static struct tty_ldisc *tty_ldisc_get(int disc)
-{
- struct tty_ldisc *ld;
- struct tty_ldisc_ops *ldops;
-
- if (disc < N_TTY || disc >= NR_LDISCS)
- return ERR_PTR(-EINVAL);
-
- /*
- * Get the ldisc ops - we may need to request them to be loaded
- * dynamically and try again.
- */
- ldops = get_ldops(disc);
- if (IS_ERR(ldops)) {
- request_module("tty-ldisc-%d", disc);
- ldops = get_ldops(disc);
- if (IS_ERR(ldops))
- return ERR_CAST(ldops);
- }
-
- ld = kmalloc(sizeof(struct tty_ldisc), GFP_KERNEL);
- if (ld == NULL) {
- put_ldops(ldops);
- return ERR_PTR(-ENOMEM);
- }
-
- ld->ops = ldops;
- atomic_set(&ld->users, 1);
- return ld;
-}
-
-static void *tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
-{
- return (*pos < NR_LDISCS) ? pos : NULL;
-}
-
-static void *tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
-{
- (*pos)++;
- return (*pos < NR_LDISCS) ? pos : NULL;
-}
-
-static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
-{
-}
-
-static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
-{
- int i = *(loff_t *)v;
- struct tty_ldisc_ops *ldops;
-
- ldops = get_ldops(i);
- if (IS_ERR(ldops))
- return 0;
- seq_printf(m, "%-10s %2d\n", ldops->name ? ldops->name : "???", i);
- put_ldops(ldops);
- return 0;
-}
-
-static const struct seq_operations tty_ldiscs_seq_ops = {
- .start = tty_ldiscs_seq_start,
- .next = tty_ldiscs_seq_next,
- .stop = tty_ldiscs_seq_stop,
- .show = tty_ldiscs_seq_show,
-};
-
-static int proc_tty_ldiscs_open(struct inode *inode, struct file *file)
-{
- return seq_open(file, &tty_ldiscs_seq_ops);
-}
-
-const struct file_operations tty_ldiscs_proc_fops = {
- .owner = THIS_MODULE,
- .open = proc_tty_ldiscs_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = seq_release,
-};
-
-/**
- * tty_ldisc_assign - set ldisc on a tty
- * @tty: tty to assign
- * @ld: line discipline
- *
- * Install an instance of a line discipline into a tty structure. The
- * ldisc must have a reference count above zero to ensure it remains.
- * The tty instance refcount starts at zero.
- *
- * Locking:
- * Caller must hold references
- */
-
-static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
-{
- tty->ldisc = ld;
-}
-
-/**
- * tty_ldisc_try - internal helper
- * @tty: the tty
- *
- * Make a single attempt to grab and bump the refcount on
- * the tty ldisc. Return 0 on failure or 1 on success. This is
- * used to implement both the waiting and non waiting versions
- * of tty_ldisc_ref
- *
- * Locking: takes tty_ldisc_lock
- */
-
-static struct tty_ldisc *tty_ldisc_try(struct tty_struct *tty)
-{
- unsigned long flags;
- struct tty_ldisc *ld;
-
- spin_lock_irqsave(&tty_ldisc_lock, flags);
- ld = NULL;
- if (test_bit(TTY_LDISC, &tty->flags))
- ld = get_ldisc(tty->ldisc);
- spin_unlock_irqrestore(&tty_ldisc_lock, flags);
- return ld;
-}
-
-/**
- * tty_ldisc_ref_wait - wait for the tty ldisc
- * @tty: tty device
- *
- * Dereference the line discipline for the terminal and take a
- * reference to it. If the line discipline is in flux then
- * wait patiently until it changes.
- *
- * Note: Must not be called from an IRQ/timer context. The caller
- * must also be careful not to hold other locks that will deadlock
- * against a discipline change, such as an existing ldisc reference
- * (which we check for)
- *
- * Locking: call functions take tty_ldisc_lock
- */
-
-struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
-{
- struct tty_ldisc *ld;
-
- /* wait_event is a macro */
- wait_event(tty_ldisc_wait, (ld = tty_ldisc_try(tty)) != NULL);
- return ld;
-}
-EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
-
-/**
- * tty_ldisc_ref - get the tty ldisc
- * @tty: tty device
- *
- * Dereference the line discipline for the terminal and take a
- * reference to it. If the line discipline is in flux then
- * return NULL. Can be called from IRQ and timer functions.
- *
- * Locking: called functions take tty_ldisc_lock
- */
-
-struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
-{
- return tty_ldisc_try(tty);
-}
-EXPORT_SYMBOL_GPL(tty_ldisc_ref);
-
-/**
- * tty_ldisc_deref - free a tty ldisc reference
- * @ld: reference to free up
- *
- * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May
- * be called in IRQ context.
- *
- * Locking: takes tty_ldisc_lock
- */
-
-void tty_ldisc_deref(struct tty_ldisc *ld)
-{
- put_ldisc(ld);
-}
-EXPORT_SYMBOL_GPL(tty_ldisc_deref);
-
-static inline void tty_ldisc_put(struct tty_ldisc *ld)
-{
- put_ldisc(ld);
-}
-
-/**
- * tty_ldisc_enable - allow ldisc use
- * @tty: terminal to activate ldisc on
- *
- * Set the TTY_LDISC flag when the line discipline can be called
- * again. Do necessary wakeups for existing sleepers. Clear the LDISC
- * changing flag to indicate any ldisc change is now over.
- *
- * Note: nobody should set the TTY_LDISC bit except via this function.
- * Clearing directly is allowed.
- */
-
-void tty_ldisc_enable(struct tty_struct *tty)
-{
- set_bit(TTY_LDISC, &tty->flags);
- clear_bit(TTY_LDISC_CHANGING, &tty->flags);
- wake_up(&tty_ldisc_wait);
-}
-
-/**
- * tty_ldisc_flush - flush line discipline queue
- * @tty: tty
- *
- * Flush the line discipline queue (if any) for this tty. If there
- * is no line discipline active this is a no-op.
- */
-
-void tty_ldisc_flush(struct tty_struct *tty)
-{
- struct tty_ldisc *ld = tty_ldisc_ref(tty);
- if (ld) {
- if (ld->ops->flush_buffer)
- ld->ops->flush_buffer(tty);
- tty_ldisc_deref(ld);
- }
- tty_buffer_flush(tty);
-}
-EXPORT_SYMBOL_GPL(tty_ldisc_flush);
-
-/**
- * tty_set_termios_ldisc - set ldisc field
- * @tty: tty structure
- * @num: line discipline number
- *
- * This is probably overkill for real world processors but
- * they are not on hot paths so a little discipline won't do
- * any harm.
- *
- * Locking: takes termios_mutex
- */
-
-static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
-{
- mutex_lock(&tty->termios_mutex);
- tty->termios->c_line = num;
- mutex_unlock(&tty->termios_mutex);
-}
-
-/**
- * tty_ldisc_open - open a line discipline
- * @tty: tty we are opening the ldisc on
- * @ld: discipline to open
- *
- * A helper opening method. Also a convenient debugging and check
- * point.
- *
- * Locking: always called with BTM already held.
- */
-
-static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
-{
- WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));
- if (ld->ops->open) {
- int ret;
- /* BTM here locks versus a hangup event */
- WARN_ON(!tty_locked());
- ret = ld->ops->open(tty);
- return ret;
- }
- return 0;
-}
-
-/**
- * tty_ldisc_close - close a line discipline
- * @tty: tty we are opening the ldisc on
- * @ld: discipline to close
- *
- * A helper close method. Also a convenient debugging and check
- * point.
- */
-
-static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
-{
- WARN_ON(!test_bit(TTY_LDISC_OPEN, &tty->flags));
- clear_bit(TTY_LDISC_OPEN, &tty->flags);
- if (ld->ops->close)
- ld->ops->close(tty);
-}
-
-/**
- * tty_ldisc_restore - helper for tty ldisc change
- * @tty: tty to recover
- * @old: previous ldisc
- *
- * Restore the previous line discipline or N_TTY when a line discipline
- * change fails due to an open error
- */
-
-static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
-{
- char buf[64];
- struct tty_ldisc *new_ldisc;
- int r;
-
- /* There is an outstanding reference here so this is safe */
- old = tty_ldisc_get(old->ops->num);
- WARN_ON(IS_ERR(old));
- tty_ldisc_assign(tty, old);
- tty_set_termios_ldisc(tty, old->ops->num);
- if (tty_ldisc_open(tty, old) < 0) {
- tty_ldisc_put(old);
- /* This driver is always present */
- new_ldisc = tty_ldisc_get(N_TTY);
- if (IS_ERR(new_ldisc))
- panic("n_tty: get");
- tty_ldisc_assign(tty, new_ldisc);
- tty_set_termios_ldisc(tty, N_TTY);
- r = tty_ldisc_open(tty, new_ldisc);
- if (r < 0)
- panic("Couldn't open N_TTY ldisc for "
- "%s --- error %d.",
- tty_name(tty, buf), r);
- }
-}
-
-/**
- * tty_ldisc_halt - shut down the line discipline
- * @tty: tty device
- *
- * Shut down the line discipline and work queue for this tty device.
- * The TTY_LDISC flag being cleared ensures no further references can
- * be obtained while the delayed work queue halt ensures that no more
- * data is fed to the ldisc.
- *
- * You need to do a 'flush_scheduled_work()' (outside the ldisc_mutex)
- * in order to make sure any currently executing ldisc work is also
- * flushed.
- */
-
-static int tty_ldisc_halt(struct tty_struct *tty)
-{
- clear_bit(TTY_LDISC, &tty->flags);
- return cancel_delayed_work_sync(&tty->buf.work);
-}
-
-/**
- * tty_set_ldisc - set line discipline
- * @tty: the terminal to set
- * @ldisc: the line discipline
- *
- * Set the discipline of a tty line. Must be called from a process
- * context. The ldisc change logic has to protect itself against any
- * overlapping ldisc change (including on the other end of pty pairs),
- * the close of one side of a tty/pty pair, and eventually hangup.
- *
- * Locking: takes tty_ldisc_lock, termios_mutex
- */
-
-int tty_set_ldisc(struct tty_struct *tty, int ldisc)
-{
- int retval;
- struct tty_ldisc *o_ldisc, *new_ldisc;
- int work, o_work = 0;
- struct tty_struct *o_tty;
-
- new_ldisc = tty_ldisc_get(ldisc);
- if (IS_ERR(new_ldisc))
- return PTR_ERR(new_ldisc);
-
- tty_lock();
- /*
- * We need to look at the tty locking here for pty/tty pairs
- * when both sides try to change in parallel.
- */
-
- o_tty = tty->link; /* o_tty is the pty side or NULL */
-
-
- /*
- * Check the no-op case
- */
-
- if (tty->ldisc->ops->num == ldisc) {
- tty_unlock();
- tty_ldisc_put(new_ldisc);
- return 0;
- }
-
- tty_unlock();
- /*
- * Problem: What do we do if this blocks ?
- * We could deadlock here
- */
-
- tty_wait_until_sent(tty, 0);
-
- tty_lock();
- mutex_lock(&tty->ldisc_mutex);
-
- /*
- * We could be midstream of another ldisc change which has
- * dropped the lock during processing. If so we need to wait.
- */
-
- while (test_bit(TTY_LDISC_CHANGING, &tty->flags)) {
- mutex_unlock(&tty->ldisc_mutex);
- tty_unlock();
- wait_event(tty_ldisc_wait,
- test_bit(TTY_LDISC_CHANGING, &tty->flags) == 0);
- tty_lock();
- mutex_lock(&tty->ldisc_mutex);
- }
-
- set_bit(TTY_LDISC_CHANGING, &tty->flags);
-
- /*
- * No more input please, we are switching. The new ldisc
- * will update this value in the ldisc open function
- */
-
- tty->receive_room = 0;
-
- o_ldisc = tty->ldisc;
-
- tty_unlock();
- /*
- * Make sure we don't change while someone holds a
- * reference to the line discipline. The TTY_LDISC bit
- * prevents anyone taking a reference once it is clear.
- * We need the lock to avoid racing reference takers.
- *
- * We must clear the TTY_LDISC bit here to avoid a livelock
- * with a userspace app continually trying to use the tty in
- * parallel to the change and re-referencing the tty.
- */
-
- work = tty_ldisc_halt(tty);
- if (o_tty)
- o_work = tty_ldisc_halt(o_tty);
-
- /*
- * Wait for ->hangup_work and ->buf.work handlers to terminate.
- * We must drop the mutex here in case a hangup is also in process.
- */
-
- mutex_unlock(&tty->ldisc_mutex);
-
- flush_scheduled_work();
-
- tty_lock();
- mutex_lock(&tty->ldisc_mutex);
- if (test_bit(TTY_HUPPED, &tty->flags)) {
- /* We were raced by the hangup method. It will have stomped
- the ldisc data and closed the ldisc down */
- clear_bit(TTY_LDISC_CHANGING, &tty->flags);
- mutex_unlock(&tty->ldisc_mutex);
- tty_ldisc_put(new_ldisc);
- tty_unlock();
- return -EIO;
- }
-
- /* Shutdown the current discipline. */
- tty_ldisc_close(tty, o_ldisc);
-
- /* Now set up the new line discipline. */
- tty_ldisc_assign(tty, new_ldisc);
- tty_set_termios_ldisc(tty, ldisc);
-
- retval = tty_ldisc_open(tty, new_ldisc);
- if (retval < 0) {
- /* Back to the old one or N_TTY if we can't */
- tty_ldisc_put(new_ldisc);
- tty_ldisc_restore(tty, o_ldisc);
- }
-
- /* At this point we hold a reference to the new ldisc and a
- a reference to the old ldisc. If we ended up flipping back
- to the existing ldisc we have two references to it */
-
- if (tty->ldisc->ops->num != o_ldisc->ops->num && tty->ops->set_ldisc)
- tty->ops->set_ldisc(tty);
-
- tty_ldisc_put(o_ldisc);
-
- /*
- * Allow ldisc referencing to occur again
- */
-
- tty_ldisc_enable(tty);
- if (o_tty)
- tty_ldisc_enable(o_tty);
-
- /* Restart the work queue in case no characters kick it off. Safe if
- already running */
- if (work)
- schedule_delayed_work(&tty->buf.work, 1);
- if (o_work)
- schedule_delayed_work(&o_tty->buf.work, 1);
- mutex_unlock(&tty->ldisc_mutex);
- tty_unlock();
- return retval;
-}
-
-/**
- * tty_reset_termios - reset terminal state
- * @tty: tty to reset
- *
- * Restore a terminal to the driver default state.
- */
-
-static void tty_reset_termios(struct tty_struct *tty)
-{
- mutex_lock(&tty->termios_mutex);
- *tty->termios = tty->driver->init_termios;
- tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
- tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
- mutex_unlock(&tty->termios_mutex);
-}
-
-
-/**
- * tty_ldisc_reinit - reinitialise the tty ldisc
- * @tty: tty to reinit
- * @ldisc: line discipline to reinitialize
- *
- * Switch the tty to a line discipline and leave the ldisc
- * state closed
- */
-
-static void tty_ldisc_reinit(struct tty_struct *tty, int ldisc)
-{
- struct tty_ldisc *ld;
-
- tty_ldisc_close(tty, tty->ldisc);
- tty_ldisc_put(tty->ldisc);
- tty->ldisc = NULL;
- /*
- * Switch the line discipline back
- */
- ld = tty_ldisc_get(ldisc);
- BUG_ON(IS_ERR(ld));
- tty_ldisc_assign(tty, ld);
- tty_set_termios_ldisc(tty, ldisc);
-}
-
-/**
- * tty_ldisc_hangup - hangup ldisc reset
- * @tty: tty being hung up
- *
- * Some tty devices reset their termios when they receive a hangup
- * event. In that situation we must also switch back to N_TTY properly
- * before we reset the termios data.
- *
- * Locking: We can take the ldisc mutex as the rest of the code is
- * careful to allow for this.
- *
- * In the pty pair case this occurs in the close() path of the
- * tty itself so we must be careful about locking rules.
- */
-
-void tty_ldisc_hangup(struct tty_struct *tty)
-{
- struct tty_ldisc *ld;
- int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
- int err = 0;
-
- /*
- * FIXME! What are the locking issues here? This may me overdoing
- * things... This question is especially important now that we've
- * removed the irqlock.
- */
- ld = tty_ldisc_ref(tty);
- if (ld != NULL) {
- /* We may have no line discipline at this point */
- if (ld->ops->flush_buffer)
- ld->ops->flush_buffer(tty);
- tty_driver_flush_buffer(tty);
- if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
- ld->ops->write_wakeup)
- ld->ops->write_wakeup(tty);
- if (ld->ops->hangup)
- ld->ops->hangup(tty);
- tty_ldisc_deref(ld);
- }
- /*
- * FIXME: Once we trust the LDISC code better we can wait here for
- * ldisc completion and fix the driver call race
- */
- wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
- wake_up_interruptible_poll(&tty->read_wait, POLLIN);
- /*
- * Shutdown the current line discipline, and reset it to
- * N_TTY if need be.
- *
- * Avoid racing set_ldisc or tty_ldisc_release
- */
- mutex_lock(&tty->ldisc_mutex);
-
- /*
- * this is like tty_ldisc_halt, but we need to give up
- * the BTM before calling cancel_delayed_work_sync,
- * which may need to wait for another function taking the BTM
- */
- clear_bit(TTY_LDISC, &tty->flags);
- tty_unlock();
- cancel_delayed_work_sync(&tty->buf.work);
- mutex_unlock(&tty->ldisc_mutex);
-
- tty_lock();
- mutex_lock(&tty->ldisc_mutex);
-
- /* At this point we have a closed ldisc and we want to
- reopen it. We could defer this to the next open but
- it means auditing a lot of other paths so this is
- a FIXME */
- if (tty->ldisc) { /* Not yet closed */
- if (reset == 0) {
- tty_ldisc_reinit(tty, tty->termios->c_line);
- err = tty_ldisc_open(tty, tty->ldisc);
- }
- /* If the re-open fails or we reset then go to N_TTY. The
- N_TTY open cannot fail */
- if (reset || err) {
- tty_ldisc_reinit(tty, N_TTY);
- WARN_ON(tty_ldisc_open(tty, tty->ldisc));
- }
- tty_ldisc_enable(tty);
- }
- mutex_unlock(&tty->ldisc_mutex);
- if (reset)
- tty_reset_termios(tty);
-}
-
-/**
- * tty_ldisc_setup - open line discipline
- * @tty: tty being shut down
- * @o_tty: pair tty for pty/tty pairs
- *
- * Called during the initial open of a tty/pty pair in order to set up the
- * line disciplines and bind them to the tty. This has no locking issues
- * as the device isn't yet active.
- */
-
-int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
-{
- struct tty_ldisc *ld = tty->ldisc;
- int retval;
-
- retval = tty_ldisc_open(tty, ld);
- if (retval)
- return retval;
-
- if (o_tty) {
- retval = tty_ldisc_open(o_tty, o_tty->ldisc);
- if (retval) {
- tty_ldisc_close(tty, ld);
- return retval;
- }
- tty_ldisc_enable(o_tty);
- }
- tty_ldisc_enable(tty);
- return 0;
-}
-/**
- * tty_ldisc_release - release line discipline
- * @tty: tty being shut down
- * @o_tty: pair tty for pty/tty pairs
- *
- * Called during the final close of a tty/pty pair in order to shut down
- * the line discpline layer. On exit the ldisc assigned is N_TTY and the
- * ldisc has not been opened.
- */
-
-void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
-{
- /*
- * Prevent flush_to_ldisc() from rescheduling the work for later. Then
- * kill any delayed work. As this is the final close it does not
- * race with the set_ldisc code path.
- */
-
- tty_unlock();
- tty_ldisc_halt(tty);
- flush_scheduled_work();
- tty_lock();
-
- mutex_lock(&tty->ldisc_mutex);
- /*
- * Now kill off the ldisc
- */
- tty_ldisc_close(tty, tty->ldisc);
- tty_ldisc_put(tty->ldisc);
- /* Force an oops if we mess this up */
- tty->ldisc = NULL;
-
- /* Ensure the next open requests the N_TTY ldisc */
- tty_set_termios_ldisc(tty, N_TTY);
- mutex_unlock(&tty->ldisc_mutex);
-
- /* This will need doing differently if we need to lock */
- if (o_tty)
- tty_ldisc_release(o_tty, NULL);
-
- /* And the memory resources remaining (buffers, termios) will be
- disposed of when the kref hits zero */
-}
-
-/**
- * tty_ldisc_init - ldisc setup for new tty
- * @tty: tty being allocated
- *
- * Set up the line discipline objects for a newly allocated tty. Note that
- * the tty structure is not completely set up when this call is made.
- */
-
-void tty_ldisc_init(struct tty_struct *tty)
-{
- struct tty_ldisc *ld = tty_ldisc_get(N_TTY);
- if (IS_ERR(ld))
- panic("n_tty: init_tty");
- tty_ldisc_assign(tty, ld);
-}
-
-void tty_ldisc_begin(void)
-{
- /* Setup the default TTY line discipline. */
- (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
-}
+++ /dev/null
-/*
- * drivers/char/tty_lock.c
- */
-#include <linux/tty.h>
-#include <linux/module.h>
-#include <linux/kallsyms.h>
-#include <linux/semaphore.h>
-#include <linux/sched.h>
-
-/*
- * The 'big tty mutex'
- *
- * This mutex is taken and released by tty_lock() and tty_unlock(),
- * replacing the older big kernel lock.
- * It can no longer be taken recursively, and does not get
- * released implicitly while sleeping.
- *
- * Don't use in new code.
- */
-static DEFINE_MUTEX(big_tty_mutex);
-struct task_struct *__big_tty_mutex_owner;
-EXPORT_SYMBOL_GPL(__big_tty_mutex_owner);
-
-/*
- * Getting the big tty mutex.
- */
-void __lockfunc tty_lock(void)
-{
- struct task_struct *task = current;
-
- WARN_ON(__big_tty_mutex_owner == task);
-
- mutex_lock(&big_tty_mutex);
- __big_tty_mutex_owner = task;
-}
-EXPORT_SYMBOL(tty_lock);
-
-void __lockfunc tty_unlock(void)
-{
- struct task_struct *task = current;
-
- WARN_ON(__big_tty_mutex_owner != task);
- __big_tty_mutex_owner = NULL;
-
- mutex_unlock(&big_tty_mutex);
-}
-EXPORT_SYMBOL(tty_unlock);
+++ /dev/null
-/*
- * Tty port functions
- */
-
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/tty.h>
-#include <linux/tty_driver.h>
-#include <linux/tty_flip.h>
-#include <linux/serial.h>
-#include <linux/timer.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/wait.h>
-#include <linux/bitops.h>
-#include <linux/delay.h>
-#include <linux/module.h>
-
-void tty_port_init(struct tty_port *port)
-{
- memset(port, 0, sizeof(*port));
- init_waitqueue_head(&port->open_wait);
- init_waitqueue_head(&port->close_wait);
- init_waitqueue_head(&port->delta_msr_wait);
- mutex_init(&port->mutex);
- mutex_init(&port->buf_mutex);
- spin_lock_init(&port->lock);
- port->close_delay = (50 * HZ) / 100;
- port->closing_wait = (3000 * HZ) / 100;
- kref_init(&port->kref);
-}
-EXPORT_SYMBOL(tty_port_init);
-
-int tty_port_alloc_xmit_buf(struct tty_port *port)
-{
- /* We may sleep in get_zeroed_page() */
- mutex_lock(&port->buf_mutex);
- if (port->xmit_buf == NULL)
- port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
- mutex_unlock(&port->buf_mutex);
- if (port->xmit_buf == NULL)
- return -ENOMEM;
- return 0;
-}
-EXPORT_SYMBOL(tty_port_alloc_xmit_buf);
-
-void tty_port_free_xmit_buf(struct tty_port *port)
-{
- mutex_lock(&port->buf_mutex);
- if (port->xmit_buf != NULL) {
- free_page((unsigned long)port->xmit_buf);
- port->xmit_buf = NULL;
- }
- mutex_unlock(&port->buf_mutex);
-}
-EXPORT_SYMBOL(tty_port_free_xmit_buf);
-
-static void tty_port_destructor(struct kref *kref)
-{
- struct tty_port *port = container_of(kref, struct tty_port, kref);
- if (port->xmit_buf)
- free_page((unsigned long)port->xmit_buf);
- if (port->ops->destruct)
- port->ops->destruct(port);
- else
- kfree(port);
-}
-
-void tty_port_put(struct tty_port *port)
-{
- if (port)
- kref_put(&port->kref, tty_port_destructor);
-}
-EXPORT_SYMBOL(tty_port_put);
-
-/**
- * tty_port_tty_get - get a tty reference
- * @port: tty port
- *
- * Return a refcount protected tty instance or NULL if the port is not
- * associated with a tty (eg due to close or hangup)
- */
-
-struct tty_struct *tty_port_tty_get(struct tty_port *port)
-{
- unsigned long flags;
- struct tty_struct *tty;
-
- spin_lock_irqsave(&port->lock, flags);
- tty = tty_kref_get(port->tty);
- spin_unlock_irqrestore(&port->lock, flags);
- return tty;
-}
-EXPORT_SYMBOL(tty_port_tty_get);
-
-/**
- * tty_port_tty_set - set the tty of a port
- * @port: tty port
- * @tty: the tty
- *
- * Associate the port and tty pair. Manages any internal refcounts.
- * Pass NULL to deassociate a port
- */
-
-void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&port->lock, flags);
- if (port->tty)
- tty_kref_put(port->tty);
- port->tty = tty_kref_get(tty);
- spin_unlock_irqrestore(&port->lock, flags);
-}
-EXPORT_SYMBOL(tty_port_tty_set);
-
-static void tty_port_shutdown(struct tty_port *port)
-{
- mutex_lock(&port->mutex);
- if (port->ops->shutdown && !port->console &&
- test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags))
- port->ops->shutdown(port);
- mutex_unlock(&port->mutex);
-}
-
-/**
- * tty_port_hangup - hangup helper
- * @port: tty port
- *
- * Perform port level tty hangup flag and count changes. Drop the tty
- * reference.
- */
-
-void tty_port_hangup(struct tty_port *port)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&port->lock, flags);
- port->count = 0;
- port->flags &= ~ASYNC_NORMAL_ACTIVE;
- if (port->tty) {
- set_bit(TTY_IO_ERROR, &port->tty->flags);
- tty_kref_put(port->tty);
- }
- port->tty = NULL;
- spin_unlock_irqrestore(&port->lock, flags);
- wake_up_interruptible(&port->open_wait);
- wake_up_interruptible(&port->delta_msr_wait);
- tty_port_shutdown(port);
-}
-EXPORT_SYMBOL(tty_port_hangup);
-
-/**
- * tty_port_carrier_raised - carrier raised check
- * @port: tty port
- *
- * Wrapper for the carrier detect logic. For the moment this is used
- * to hide some internal details. This will eventually become entirely
- * internal to the tty port.
- */
-
-int tty_port_carrier_raised(struct tty_port *port)
-{
- if (port->ops->carrier_raised == NULL)
- return 1;
- return port->ops->carrier_raised(port);
-}
-EXPORT_SYMBOL(tty_port_carrier_raised);
-
-/**
- * tty_port_raise_dtr_rts - Raise DTR/RTS
- * @port: tty port
- *
- * Wrapper for the DTR/RTS raise logic. For the moment this is used
- * to hide some internal details. This will eventually become entirely
- * internal to the tty port.
- */
-
-void tty_port_raise_dtr_rts(struct tty_port *port)
-{
- if (port->ops->dtr_rts)
- port->ops->dtr_rts(port, 1);
-}
-EXPORT_SYMBOL(tty_port_raise_dtr_rts);
-
-/**
- * tty_port_lower_dtr_rts - Lower DTR/RTS
- * @port: tty port
- *
- * Wrapper for the DTR/RTS raise logic. For the moment this is used
- * to hide some internal details. This will eventually become entirely
- * internal to the tty port.
- */
-
-void tty_port_lower_dtr_rts(struct tty_port *port)
-{
- if (port->ops->dtr_rts)
- port->ops->dtr_rts(port, 0);
-}
-EXPORT_SYMBOL(tty_port_lower_dtr_rts);
-
-/**
- * tty_port_block_til_ready - Waiting logic for tty open
- * @port: the tty port being opened
- * @tty: the tty device being bound
- * @filp: the file pointer of the opener
- *
- * Implement the core POSIX/SuS tty behaviour when opening a tty device.
- * Handles:
- * - hangup (both before and during)
- * - non blocking open
- * - rts/dtr/dcd
- * - signals
- * - port flags and counts
- *
- * The passed tty_port must implement the carrier_raised method if it can
- * do carrier detect and the dtr_rts method if it supports software
- * management of these lines. Note that the dtr/rts raise is done each
- * iteration as a hangup may have previously dropped them while we wait.
- */
-
-int tty_port_block_til_ready(struct tty_port *port,
- struct tty_struct *tty, struct file *filp)
-{
- int do_clocal = 0, retval;
- unsigned long flags;
- DEFINE_WAIT(wait);
- int cd;
-
- /* block if port is in the process of being closed */
- if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
- wait_event_interruptible_tty(port->close_wait,
- !(port->flags & ASYNC_CLOSING));
- if (port->flags & ASYNC_HUP_NOTIFY)
- return -EAGAIN;
- else
- return -ERESTARTSYS;
- }
-
- /* if non-blocking mode is set we can pass directly to open unless
- the port has just hung up or is in another error state */
- if (tty->flags & (1 << TTY_IO_ERROR)) {
- port->flags |= ASYNC_NORMAL_ACTIVE;
- return 0;
- }
- if (filp->f_flags & O_NONBLOCK) {
- /* Indicate we are open */
- if (tty->termios->c_cflag & CBAUD)
- tty_port_raise_dtr_rts(port);
- port->flags |= ASYNC_NORMAL_ACTIVE;
- return 0;
- }
-
- if (C_CLOCAL(tty))
- do_clocal = 1;
-
- /* Block waiting until we can proceed. We may need to wait for the
- carrier, but we must also wait for any close that is in progress
- before the next open may complete */
-
- retval = 0;
-
- /* The port lock protects the port counts */
- spin_lock_irqsave(&port->lock, flags);
- if (!tty_hung_up_p(filp))
- port->count--;
- port->blocked_open++;
- spin_unlock_irqrestore(&port->lock, flags);
-
- while (1) {
- /* Indicate we are open */
- if (tty->termios->c_cflag & CBAUD)
- tty_port_raise_dtr_rts(port);
-
- prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);
- /* Check for a hangup or uninitialised port.
- Return accordingly */
- if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) {
- if (port->flags & ASYNC_HUP_NOTIFY)
- retval = -EAGAIN;
- else
- retval = -ERESTARTSYS;
- break;
- }
- /* Probe the carrier. For devices with no carrier detect this
- will always return true */
- cd = tty_port_carrier_raised(port);
- if (!(port->flags & ASYNC_CLOSING) &&
- (do_clocal || cd))
- break;
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
- tty_unlock();
- schedule();
- tty_lock();
- }
- finish_wait(&port->open_wait, &wait);
-
- /* Update counts. A parallel hangup will have set count to zero and
- we must not mess that up further */
- spin_lock_irqsave(&port->lock, flags);
- if (!tty_hung_up_p(filp))
- port->count++;
- port->blocked_open--;
- if (retval == 0)
- port->flags |= ASYNC_NORMAL_ACTIVE;
- spin_unlock_irqrestore(&port->lock, flags);
- return retval;
-}
-EXPORT_SYMBOL(tty_port_block_til_ready);
-
-int tty_port_close_start(struct tty_port *port,
- struct tty_struct *tty, struct file *filp)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&port->lock, flags);
- if (tty_hung_up_p(filp)) {
- spin_unlock_irqrestore(&port->lock, flags);
- return 0;
- }
-
- if (tty->count == 1 && port->count != 1) {
- printk(KERN_WARNING
- "tty_port_close_start: tty->count = 1 port count = %d.\n",
- port->count);
- port->count = 1;
- }
- if (--port->count < 0) {
- printk(KERN_WARNING "tty_port_close_start: count = %d\n",
- port->count);
- port->count = 0;
- }
-
- if (port->count) {
- spin_unlock_irqrestore(&port->lock, flags);
- if (port->ops->drop)
- port->ops->drop(port);
- return 0;
- }
- set_bit(ASYNCB_CLOSING, &port->flags);
- tty->closing = 1;
- spin_unlock_irqrestore(&port->lock, flags);
- /* Don't block on a stalled port, just pull the chain */
- if (tty->flow_stopped)
- tty_driver_flush_buffer(tty);
- if (test_bit(ASYNCB_INITIALIZED, &port->flags) &&
- port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
- tty_wait_until_sent(tty, port->closing_wait);
- if (port->drain_delay) {
- unsigned int bps = tty_get_baud_rate(tty);
- long timeout;
-
- if (bps > 1200)
- timeout = max_t(long,
- (HZ * 10 * port->drain_delay) / bps, HZ / 10);
- else
- timeout = 2 * HZ;
- schedule_timeout_interruptible(timeout);
- }
- /* Flush the ldisc buffering */
- tty_ldisc_flush(tty);
-
- /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to
- hang up the line */
- if (tty->termios->c_cflag & HUPCL)
- tty_port_lower_dtr_rts(port);
-
- /* Don't call port->drop for the last reference. Callers will want
- to drop the last active reference in ->shutdown() or the tty
- shutdown path */
- return 1;
-}
-EXPORT_SYMBOL(tty_port_close_start);
-
-void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&port->lock, flags);
- tty->closing = 0;
-
- if (port->blocked_open) {
- spin_unlock_irqrestore(&port->lock, flags);
- if (port->close_delay) {
- msleep_interruptible(
- jiffies_to_msecs(port->close_delay));
- }
- spin_lock_irqsave(&port->lock, flags);
- wake_up_interruptible(&port->open_wait);
- }
- port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING);
- wake_up_interruptible(&port->close_wait);
- spin_unlock_irqrestore(&port->lock, flags);
-}
-EXPORT_SYMBOL(tty_port_close_end);
-
-void tty_port_close(struct tty_port *port, struct tty_struct *tty,
- struct file *filp)
-{
- if (tty_port_close_start(port, tty, filp) == 0)
- return;
- tty_port_shutdown(port);
- set_bit(TTY_IO_ERROR, &tty->flags);
- tty_port_close_end(port, tty);
- tty_port_tty_set(port, NULL);
-}
-EXPORT_SYMBOL(tty_port_close);
-
-int tty_port_open(struct tty_port *port, struct tty_struct *tty,
- struct file *filp)
-{
- spin_lock_irq(&port->lock);
- if (!tty_hung_up_p(filp))
- ++port->count;
- spin_unlock_irq(&port->lock);
- tty_port_tty_set(port, tty);
-
- /*
- * Do the device-specific open only if the hardware isn't
- * already initialized. Serialize open and shutdown using the
- * port mutex.
- */
-
- mutex_lock(&port->mutex);
-
- if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) {
- clear_bit(TTY_IO_ERROR, &tty->flags);
- if (port->ops->activate) {
- int retval = port->ops->activate(port, tty);
- if (retval) {
- mutex_unlock(&port->mutex);
- return retval;
- }
- }
- set_bit(ASYNCB_INITIALIZED, &port->flags);
- }
- mutex_unlock(&port->mutex);
- return tty_port_block_til_ready(port, tty, filp);
-}
-
-EXPORT_SYMBOL(tty_port_open);
--- /dev/null
+obj-y += tty_io.o n_tty.o tty_ioctl.o tty_ldisc.o \
+ tty_buffer.o tty_port.o tty_mutex.o
+obj-$(CONFIG_LEGACY_PTYS) += pty.o
+obj-$(CONFIG_UNIX98_PTYS) += pty.o
+obj-$(CONFIG_AUDIT) += tty_audit.o
+obj-$(CONFIG_MAGIC_SYSRQ) += sysrq.o
+obj-$(CONFIG_N_HDLC) += n_hdlc.o
+obj-$(CONFIG_N_GSM) += n_gsm.o
+obj-$(CONFIG_R3964) += n_r3964.o
--- /dev/null
+/*
+ * n_gsm.c GSM 0710 tty multiplexor
+ * Copyright (c) 2009/10 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * * THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE *
+ *
+ * TO DO:
+ * Mostly done: ioctls for setting modes/timing
+ * Partly done: hooks so you can pull off frames to non tty devs
+ * Restart DLCI 0 when it closes ?
+ * Test basic encoding
+ * Improve the tx engine
+ * Resolve tx side locking by adding a queue_head and routing
+ * all control traffic via it
+ * General tidy/document
+ * Review the locking/move to refcounts more (mux now moved to an
+ * alloc/free model ready)
+ * Use newest tty open/close port helpers and install hooks
+ * What to do about power functions ?
+ * Termios setting and negotiation
+ * Do we need a 'which mux are you' ioctl to correlate mux and tty sets
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/bitops.h>
+#include <linux/file.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/tty_flip.h>
+#include <linux/tty_driver.h>
+#include <linux/serial.h>
+#include <linux/kfifo.h>
+#include <linux/skbuff.h>
+#include <linux/gsmmux.h>
+
+static int debug;
+module_param(debug, int, 0600);
+
+#define T1 (HZ/10)
+#define T2 (HZ/3)
+#define N2 3
+
+/* Use long timers for testing at low speed with debug on */
+#ifdef DEBUG_TIMING
+#define T1 HZ
+#define T2 (2 * HZ)
+#endif
+
+/* Semi-arbitary buffer size limits. 0710 is normally run with 32-64 byte
+ limits so this is plenty */
+#define MAX_MRU 512
+#define MAX_MTU 512
+
+/*
+ * Each block of data we have queued to go out is in the form of
+ * a gsm_msg which holds everything we need in a link layer independant
+ * format
+ */
+
+struct gsm_msg {
+ struct gsm_msg *next;
+ u8 addr; /* DLCI address + flags */
+ u8 ctrl; /* Control byte + flags */
+ unsigned int len; /* Length of data block (can be zero) */
+ unsigned char *data; /* Points into buffer but not at the start */
+ unsigned char buffer[0];
+};
+
+/*
+ * Each active data link has a gsm_dlci structure associated which ties
+ * the link layer to an optional tty (if the tty side is open). To avoid
+ * complexity right now these are only ever freed up when the mux is
+ * shut down.
+ *
+ * At the moment we don't free DLCI objects until the mux is torn down
+ * this avoid object life time issues but might be worth review later.
+ */
+
+struct gsm_dlci {
+ struct gsm_mux *gsm;
+ int addr;
+ int state;
+#define DLCI_CLOSED 0
+#define DLCI_OPENING 1 /* Sending SABM not seen UA */
+#define DLCI_OPEN 2 /* SABM/UA complete */
+#define DLCI_CLOSING 3 /* Sending DISC not seen UA/DM */
+
+ /* Link layer */
+ spinlock_t lock; /* Protects the internal state */
+ struct timer_list t1; /* Retransmit timer for SABM and UA */
+ int retries;
+ /* Uplink tty if active */
+ struct tty_port port; /* The tty bound to this DLCI if there is one */
+ struct kfifo *fifo; /* Queue fifo for the DLCI */
+ struct kfifo _fifo; /* For new fifo API porting only */
+ int adaption; /* Adaption layer in use */
+ u32 modem_rx; /* Our incoming virtual modem lines */
+ u32 modem_tx; /* Our outgoing modem lines */
+ int dead; /* Refuse re-open */
+ /* Flow control */
+ int throttled; /* Private copy of throttle state */
+ int constipated; /* Throttle status for outgoing */
+ /* Packetised I/O */
+ struct sk_buff *skb; /* Frame being sent */
+ struct sk_buff_head skb_list; /* Queued frames */
+ /* Data handling callback */
+ void (*data)(struct gsm_dlci *dlci, u8 *data, int len);
+};
+
+/* DLCI 0, 62/63 are special or reseved see gsmtty_open */
+
+#define NUM_DLCI 64
+
+/*
+ * DLCI 0 is used to pass control blocks out of band of the data
+ * flow (and with a higher link priority). One command can be outstanding
+ * at a time and we use this structure to manage them. They are created
+ * and destroyed by the user context, and updated by the receive paths
+ * and timers
+ */
+
+struct gsm_control {
+ u8 cmd; /* Command we are issuing */
+ u8 *data; /* Data for the command in case we retransmit */
+ int len; /* Length of block for retransmission */
+ int done; /* Done flag */
+ int error; /* Error if any */
+};
+
+/*
+ * Each GSM mux we have is represented by this structure. If we are
+ * operating as an ldisc then we use this structure as our ldisc
+ * state. We need to sort out lifetimes and locking with respect
+ * to the gsm mux array. For now we don't free DLCI objects that
+ * have been instantiated until the mux itself is terminated.
+ *
+ * To consider further: tty open versus mux shutdown.
+ */
+
+struct gsm_mux {
+ struct tty_struct *tty; /* The tty our ldisc is bound to */
+ spinlock_t lock;
+
+ /* Events on the GSM channel */
+ wait_queue_head_t event;
+
+ /* Bits for GSM mode decoding */
+
+ /* Framing Layer */
+ unsigned char *buf;
+ int state;
+#define GSM_SEARCH 0
+#define GSM_START 1
+#define GSM_ADDRESS 2
+#define GSM_CONTROL 3
+#define GSM_LEN 4
+#define GSM_DATA 5
+#define GSM_FCS 6
+#define GSM_OVERRUN 7
+ unsigned int len;
+ unsigned int address;
+ unsigned int count;
+ int escape;
+ int encoding;
+ u8 control;
+ u8 fcs;
+ u8 *txframe; /* TX framing buffer */
+
+ /* Methods for the receiver side */
+ void (*receive)(struct gsm_mux *gsm, u8 ch);
+ void (*error)(struct gsm_mux *gsm, u8 ch, u8 flag);
+ /* And transmit side */
+ int (*output)(struct gsm_mux *mux, u8 *data, int len);
+
+ /* Link Layer */
+ unsigned int mru;
+ unsigned int mtu;
+ int initiator; /* Did we initiate connection */
+ int dead; /* Has the mux been shut down */
+ struct gsm_dlci *dlci[NUM_DLCI];
+ int constipated; /* Asked by remote to shut up */
+
+ spinlock_t tx_lock;
+ unsigned int tx_bytes; /* TX data outstanding */
+#define TX_THRESH_HI 8192
+#define TX_THRESH_LO 2048
+ struct gsm_msg *tx_head; /* Pending data packets */
+ struct gsm_msg *tx_tail;
+
+ /* Control messages */
+ struct timer_list t2_timer; /* Retransmit timer for commands */
+ int cretries; /* Command retry counter */
+ struct gsm_control *pending_cmd;/* Our current pending command */
+ spinlock_t control_lock; /* Protects the pending command */
+
+ /* Configuration */
+ int adaption; /* 1 or 2 supported */
+ u8 ftype; /* UI or UIH */
+ int t1, t2; /* Timers in 1/100th of a sec */
+ int n2; /* Retry count */
+
+ /* Statistics (not currently exposed) */
+ unsigned long bad_fcs;
+ unsigned long malformed;
+ unsigned long io_error;
+ unsigned long bad_size;
+ unsigned long unsupported;
+};
+
+
+/*
+ * Mux objects - needed so that we can translate a tty index into the
+ * relevant mux and DLCI.
+ */
+
+#define MAX_MUX 4 /* 256 minors */
+static struct gsm_mux *gsm_mux[MAX_MUX]; /* GSM muxes */
+static spinlock_t gsm_mux_lock;
+
+/*
+ * This section of the driver logic implements the GSM encodings
+ * both the basic and the 'advanced'. Reliable transport is not
+ * supported.
+ */
+
+#define CR 0x02
+#define EA 0x01
+#define PF 0x10
+
+/* I is special: the rest are ..*/
+#define RR 0x01
+#define UI 0x03
+#define RNR 0x05
+#define REJ 0x09
+#define DM 0x0F
+#define SABM 0x2F
+#define DISC 0x43
+#define UA 0x63
+#define UIH 0xEF
+
+/* Channel commands */
+#define CMD_NSC 0x09
+#define CMD_TEST 0x11
+#define CMD_PSC 0x21
+#define CMD_RLS 0x29
+#define CMD_FCOFF 0x31
+#define CMD_PN 0x41
+#define CMD_RPN 0x49
+#define CMD_FCON 0x51
+#define CMD_CLD 0x61
+#define CMD_SNC 0x69
+#define CMD_MSC 0x71
+
+/* Virtual modem bits */
+#define MDM_FC 0x01
+#define MDM_RTC 0x02
+#define MDM_RTR 0x04
+#define MDM_IC 0x20
+#define MDM_DV 0x40
+
+#define GSM0_SOF 0xF9
+#define GSM1_SOF 0x7E
+#define GSM1_ESCAPE 0x7D
+#define GSM1_ESCAPE_BITS 0x20
+#define XON 0x11
+#define XOFF 0x13
+
+static const struct tty_port_operations gsm_port_ops;
+
+/*
+ * CRC table for GSM 0710
+ */
+
+static const u8 gsm_fcs8[256] = {
+ 0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75,
+ 0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B,
+ 0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69,
+ 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67,
+ 0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D,
+ 0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43,
+ 0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51,
+ 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
+ 0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05,
+ 0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B,
+ 0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19,
+ 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17,
+ 0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D,
+ 0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33,
+ 0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21,
+ 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
+ 0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95,
+ 0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B,
+ 0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89,
+ 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87,
+ 0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD,
+ 0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3,
+ 0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1,
+ 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
+ 0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5,
+ 0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB,
+ 0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9,
+ 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7,
+ 0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD,
+ 0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3,
+ 0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1,
+ 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
+};
+
+#define INIT_FCS 0xFF
+#define GOOD_FCS 0xCF
+
+/**
+ * gsm_fcs_add - update FCS
+ * @fcs: Current FCS
+ * @c: Next data
+ *
+ * Update the FCS to include c. Uses the algorithm in the specification
+ * notes.
+ */
+
+static inline u8 gsm_fcs_add(u8 fcs, u8 c)
+{
+ return gsm_fcs8[fcs ^ c];
+}
+
+/**
+ * gsm_fcs_add_block - update FCS for a block
+ * @fcs: Current FCS
+ * @c: buffer of data
+ * @len: length of buffer
+ *
+ * Update the FCS to include c. Uses the algorithm in the specification
+ * notes.
+ */
+
+static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len)
+{
+ while (len--)
+ fcs = gsm_fcs8[fcs ^ *c++];
+ return fcs;
+}
+
+/**
+ * gsm_read_ea - read a byte into an EA
+ * @val: variable holding value
+ * c: byte going into the EA
+ *
+ * Processes one byte of an EA. Updates the passed variable
+ * and returns 1 if the EA is now completely read
+ */
+
+static int gsm_read_ea(unsigned int *val, u8 c)
+{
+ /* Add the next 7 bits into the value */
+ *val <<= 7;
+ *val |= c >> 1;
+ /* Was this the last byte of the EA 1 = yes*/
+ return c & EA;
+}
+
+/**
+ * gsm_encode_modem - encode modem data bits
+ * @dlci: DLCI to encode from
+ *
+ * Returns the correct GSM encoded modem status bits (6 bit field) for
+ * the current status of the DLCI and attached tty object
+ */
+
+static u8 gsm_encode_modem(const struct gsm_dlci *dlci)
+{
+ u8 modembits = 0;
+ /* FC is true flow control not modem bits */
+ if (dlci->throttled)
+ modembits |= MDM_FC;
+ if (dlci->modem_tx & TIOCM_DTR)
+ modembits |= MDM_RTC;
+ if (dlci->modem_tx & TIOCM_RTS)
+ modembits |= MDM_RTR;
+ if (dlci->modem_tx & TIOCM_RI)
+ modembits |= MDM_IC;
+ if (dlci->modem_tx & TIOCM_CD)
+ modembits |= MDM_DV;
+ return modembits;
+}
+
+/**
+ * gsm_print_packet - display a frame for debug
+ * @hdr: header to print before decode
+ * @addr: address EA from the frame
+ * @cr: C/R bit from the frame
+ * @control: control including PF bit
+ * @data: following data bytes
+ * @dlen: length of data
+ *
+ * Displays a packet in human readable format for debugging purposes. The
+ * style is based on amateur radio LAP-B dump display.
+ */
+
+static void gsm_print_packet(const char *hdr, int addr, int cr,
+ u8 control, const u8 *data, int dlen)
+{
+ if (!(debug & 1))
+ return;
+
+ printk(KERN_INFO "%s %d) %c: ", hdr, addr, "RC"[cr]);
+
+ switch (control & ~PF) {
+ case SABM:
+ printk(KERN_CONT "SABM");
+ break;
+ case UA:
+ printk(KERN_CONT "UA");
+ break;
+ case DISC:
+ printk(KERN_CONT "DISC");
+ break;
+ case DM:
+ printk(KERN_CONT "DM");
+ break;
+ case UI:
+ printk(KERN_CONT "UI");
+ break;
+ case UIH:
+ printk(KERN_CONT "UIH");
+ break;
+ default:
+ if (!(control & 0x01)) {
+ printk(KERN_CONT "I N(S)%d N(R)%d",
+ (control & 0x0E) >> 1, (control & 0xE)>> 5);
+ } else switch (control & 0x0F) {
+ case RR:
+ printk("RR(%d)", (control & 0xE0) >> 5);
+ break;
+ case RNR:
+ printk("RNR(%d)", (control & 0xE0) >> 5);
+ break;
+ case REJ:
+ printk("REJ(%d)", (control & 0xE0) >> 5);
+ break;
+ default:
+ printk(KERN_CONT "[%02X]", control);
+ }
+ }
+
+ if (control & PF)
+ printk(KERN_CONT "(P)");
+ else
+ printk(KERN_CONT "(F)");
+
+ if (dlen) {
+ int ct = 0;
+ while (dlen--) {
+ if (ct % 8 == 0)
+ printk(KERN_CONT "\n ");
+ printk(KERN_CONT "%02X ", *data++);
+ ct++;
+ }
+ }
+ printk(KERN_CONT "\n");
+}
+
+
+/*
+ * Link level transmission side
+ */
+
+/**
+ * gsm_stuff_packet - bytestuff a packet
+ * @ibuf: input
+ * @obuf: output
+ * @len: length of input
+ *
+ * Expand a buffer by bytestuffing it. The worst case size change
+ * is doubling and the caller is responsible for handing out
+ * suitable sized buffers.
+ */
+
+static int gsm_stuff_frame(const u8 *input, u8 *output, int len)
+{
+ int olen = 0;
+ while (len--) {
+ if (*input == GSM1_SOF || *input == GSM1_ESCAPE
+ || *input == XON || *input == XOFF) {
+ *output++ = GSM1_ESCAPE;
+ *output++ = *input++ ^ GSM1_ESCAPE_BITS;
+ olen++;
+ } else
+ *output++ = *input++;
+ olen++;
+ }
+ return olen;
+}
+
+static void hex_packet(const unsigned char *p, int len)
+{
+ int i;
+ for (i = 0; i < len; i++) {
+ if (i && (i % 16) == 0)
+ printk("\n");
+ printk("%02X ", *p++);
+ }
+ printk("\n");
+}
+
+/**
+ * gsm_send - send a control frame
+ * @gsm: our GSM mux
+ * @addr: address for control frame
+ * @cr: command/response bit
+ * @control: control byte including PF bit
+ *
+ * Format up and transmit a control frame. These do not go via the
+ * queueing logic as they should be transmitted ahead of data when
+ * they are needed.
+ *
+ * FIXME: Lock versus data TX path
+ */
+
+static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
+{
+ int len;
+ u8 cbuf[10];
+ u8 ibuf[3];
+
+ switch (gsm->encoding) {
+ case 0:
+ cbuf[0] = GSM0_SOF;
+ cbuf[1] = (addr << 2) | (cr << 1) | EA;
+ cbuf[2] = control;
+ cbuf[3] = EA; /* Length of data = 0 */
+ cbuf[4] = 0xFF - gsm_fcs_add_block(INIT_FCS, cbuf + 1, 3);
+ cbuf[5] = GSM0_SOF;
+ len = 6;
+ break;
+ case 1:
+ case 2:
+ /* Control frame + packing (but not frame stuffing) in mode 1 */
+ ibuf[0] = (addr << 2) | (cr << 1) | EA;
+ ibuf[1] = control;
+ ibuf[2] = 0xFF - gsm_fcs_add_block(INIT_FCS, ibuf, 2);
+ /* Stuffing may double the size worst case */
+ len = gsm_stuff_frame(ibuf, cbuf + 1, 3);
+ /* Now add the SOF markers */
+ cbuf[0] = GSM1_SOF;
+ cbuf[len + 1] = GSM1_SOF;
+ /* FIXME: we can omit the lead one in many cases */
+ len += 2;
+ break;
+ default:
+ WARN_ON(1);
+ return;
+ }
+ gsm->output(gsm, cbuf, len);
+ gsm_print_packet("-->", addr, cr, control, NULL, 0);
+}
+
+/**
+ * gsm_response - send a control response
+ * @gsm: our GSM mux
+ * @addr: address for control frame
+ * @control: control byte including PF bit
+ *
+ * Format up and transmit a link level response frame.
+ */
+
+static inline void gsm_response(struct gsm_mux *gsm, int addr, int control)
+{
+ gsm_send(gsm, addr, 0, control);
+}
+
+/**
+ * gsm_command - send a control command
+ * @gsm: our GSM mux
+ * @addr: address for control frame
+ * @control: control byte including PF bit
+ *
+ * Format up and transmit a link level command frame.
+ */
+
+static inline void gsm_command(struct gsm_mux *gsm, int addr, int control)
+{
+ gsm_send(gsm, addr, 1, control);
+}
+
+/* Data transmission */
+
+#define HDR_LEN 6 /* ADDR CTRL [LEN.2] DATA FCS */
+
+/**
+ * gsm_data_alloc - allocate data frame
+ * @gsm: GSM mux
+ * @addr: DLCI address
+ * @len: length excluding header and FCS
+ * @ctrl: control byte
+ *
+ * Allocate a new data buffer for sending frames with data. Space is left
+ * at the front for header bytes but that is treated as an implementation
+ * detail and not for the high level code to use
+ */
+
+static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len,
+ u8 ctrl)
+{
+ struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN,
+ GFP_ATOMIC);
+ if (m == NULL)
+ return NULL;
+ m->data = m->buffer + HDR_LEN - 1; /* Allow for FCS */
+ m->len = len;
+ m->addr = addr;
+ m->ctrl = ctrl;
+ m->next = NULL;
+ return m;
+}
+
+/**
+ * gsm_data_kick - poke the queue
+ * @gsm: GSM Mux
+ *
+ * The tty device has called us to indicate that room has appeared in
+ * the transmit queue. Ram more data into the pipe if we have any
+ *
+ * FIXME: lock against link layer control transmissions
+ */
+
+static void gsm_data_kick(struct gsm_mux *gsm)
+{
+ struct gsm_msg *msg = gsm->tx_head;
+ int len;
+ int skip_sof = 0;
+
+ /* FIXME: We need to apply this solely to data messages */
+ if (gsm->constipated)
+ return;
+
+ while (gsm->tx_head != NULL) {
+ msg = gsm->tx_head;
+ if (gsm->encoding != 0) {
+ gsm->txframe[0] = GSM1_SOF;
+ len = gsm_stuff_frame(msg->data,
+ gsm->txframe + 1, msg->len);
+ gsm->txframe[len + 1] = GSM1_SOF;
+ len += 2;
+ } else {
+ gsm->txframe[0] = GSM0_SOF;
+ memcpy(gsm->txframe + 1 , msg->data, msg->len);
+ gsm->txframe[msg->len + 1] = GSM0_SOF;
+ len = msg->len + 2;
+ }
+
+ if (debug & 4) {
+ printk("gsm_data_kick: \n");
+ hex_packet(gsm->txframe, len);
+ }
+
+ if (gsm->output(gsm, gsm->txframe + skip_sof,
+ len - skip_sof) < 0)
+ break;
+ /* FIXME: Can eliminate one SOF in many more cases */
+ gsm->tx_head = msg->next;
+ if (gsm->tx_head == NULL)
+ gsm->tx_tail = NULL;
+ gsm->tx_bytes -= msg->len;
+ kfree(msg);
+ /* For a burst of frames skip the extra SOF within the
+ burst */
+ skip_sof = 1;
+ }
+}
+
+/**
+ * __gsm_data_queue - queue a UI or UIH frame
+ * @dlci: DLCI sending the data
+ * @msg: message queued
+ *
+ * Add data to the transmit queue and try and get stuff moving
+ * out of the mux tty if not already doing so. The Caller must hold
+ * the gsm tx lock.
+ */
+
+static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
+{
+ struct gsm_mux *gsm = dlci->gsm;
+ u8 *dp = msg->data;
+ u8 *fcs = dp + msg->len;
+
+ /* Fill in the header */
+ if (gsm->encoding == 0) {
+ if (msg->len < 128)
+ *--dp = (msg->len << 1) | EA;
+ else {
+ *--dp = (msg->len >> 6) | EA;
+ *--dp = (msg->len & 127) << 1;
+ }
+ }
+
+ *--dp = msg->ctrl;
+ if (gsm->initiator)
+ *--dp = (msg->addr << 2) | 2 | EA;
+ else
+ *--dp = (msg->addr << 2) | EA;
+ *fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp);
+ /* Ugly protocol layering violation */
+ if (msg->ctrl == UI || msg->ctrl == (UI|PF))
+ *fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len);
+ *fcs = 0xFF - *fcs;
+
+ gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl,
+ msg->data, msg->len);
+
+ /* Move the header back and adjust the length, also allow for the FCS
+ now tacked on the end */
+ msg->len += (msg->data - dp) + 1;
+ msg->data = dp;
+
+ /* Add to the actual output queue */
+ if (gsm->tx_tail)
+ gsm->tx_tail->next = msg;
+ else
+ gsm->tx_head = msg;
+ gsm->tx_tail = msg;
+ gsm->tx_bytes += msg->len;
+ gsm_data_kick(gsm);
+}
+
+/**
+ * gsm_data_queue - queue a UI or UIH frame
+ * @dlci: DLCI sending the data
+ * @msg: message queued
+ *
+ * Add data to the transmit queue and try and get stuff moving
+ * out of the mux tty if not already doing so. Take the
+ * the gsm tx lock and dlci lock.
+ */
+
+static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
+ __gsm_data_queue(dlci, msg);
+ spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
+}
+
+/**
+ * gsm_dlci_data_output - try and push data out of a DLCI
+ * @gsm: mux
+ * @dlci: the DLCI to pull data from
+ *
+ * Pull data from a DLCI and send it into the transmit queue if there
+ * is data. Keep to the MRU of the mux. This path handles the usual tty
+ * interface which is a byte stream with optional modem data.
+ *
+ * Caller must hold the tx_lock of the mux.
+ */
+
+static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
+{
+ struct gsm_msg *msg;
+ u8 *dp;
+ int len, size;
+ int h = dlci->adaption - 1;
+
+ len = kfifo_len(dlci->fifo);
+ if (len == 0)
+ return 0;
+
+ /* MTU/MRU count only the data bits */
+ if (len > gsm->mtu)
+ len = gsm->mtu;
+
+ size = len + h;
+
+ msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype);
+ /* FIXME: need a timer or something to kick this so it can't
+ get stuck with no work outstanding and no buffer free */
+ if (msg == NULL)
+ return -ENOMEM;
+ dp = msg->data;
+ switch (dlci->adaption) {
+ case 1: /* Unstructured */
+ break;
+ case 2: /* Unstructed with modem bits. Always one byte as we never
+ send inline break data */
+ *dp += gsm_encode_modem(dlci);
+ len--;
+ break;
+ }
+ WARN_ON(kfifo_out_locked(dlci->fifo, dp , len, &dlci->lock) != len);
+ __gsm_data_queue(dlci, msg);
+ /* Bytes of data we used up */
+ return size;
+}
+
+/**
+ * gsm_dlci_data_output_framed - try and push data out of a DLCI
+ * @gsm: mux
+ * @dlci: the DLCI to pull data from
+ *
+ * Pull data from a DLCI and send it into the transmit queue if there
+ * is data. Keep to the MRU of the mux. This path handles framed data
+ * queued as skbuffs to the DLCI.
+ *
+ * Caller must hold the tx_lock of the mux.
+ */
+
+static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
+ struct gsm_dlci *dlci)
+{
+ struct gsm_msg *msg;
+ u8 *dp;
+ int len, size;
+ int last = 0, first = 0;
+ int overhead = 0;
+
+ /* One byte per frame is used for B/F flags */
+ if (dlci->adaption == 4)
+ overhead = 1;
+
+ /* dlci->skb is locked by tx_lock */
+ if (dlci->skb == NULL) {
+ dlci->skb = skb_dequeue(&dlci->skb_list);
+ if (dlci->skb == NULL)
+ return 0;
+ first = 1;
+ }
+ len = dlci->skb->len + overhead;
+
+ /* MTU/MRU count only the data bits */
+ if (len > gsm->mtu) {
+ if (dlci->adaption == 3) {
+ /* Over long frame, bin it */
+ kfree_skb(dlci->skb);
+ dlci->skb = NULL;
+ return 0;
+ }
+ len = gsm->mtu;
+ } else
+ last = 1;
+
+ size = len + overhead;
+ msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype);
+
+ /* FIXME: need a timer or something to kick this so it can't
+ get stuck with no work outstanding and no buffer free */
+ if (msg == NULL)
+ return -ENOMEM;
+ dp = msg->data;
+
+ if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */
+ /* Flag byte to carry the start/end info */
+ *dp++ = last << 7 | first << 6 | 1; /* EA */
+ len--;
+ }
+ memcpy(dp, skb_pull(dlci->skb, len), len);
+ __gsm_data_queue(dlci, msg);
+ if (last)
+ dlci->skb = NULL;
+ return size;
+}
+
+/**
+ * gsm_dlci_data_sweep - look for data to send
+ * @gsm: the GSM mux
+ *
+ * Sweep the GSM mux channels in priority order looking for ones with
+ * data to send. We could do with optimising this scan a bit. We aim
+ * to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit
+ * TX_THRESH_LO we get called again
+ *
+ * FIXME: We should round robin between groups and in theory you can
+ * renegotiate DLCI priorities with optional stuff. Needs optimising.
+ */
+
+static void gsm_dlci_data_sweep(struct gsm_mux *gsm)
+{
+ int len;
+ /* Priority ordering: We should do priority with RR of the groups */
+ int i = 1;
+
+ while (i < NUM_DLCI) {
+ struct gsm_dlci *dlci;
+
+ if (gsm->tx_bytes > TX_THRESH_HI)
+ break;
+ dlci = gsm->dlci[i];
+ if (dlci == NULL || dlci->constipated) {
+ i++;
+ continue;
+ }
+ if (dlci->adaption < 3)
+ len = gsm_dlci_data_output(gsm, dlci);
+ else
+ len = gsm_dlci_data_output_framed(gsm, dlci);
+ if (len < 0)
+ break;
+ /* DLCI empty - try the next */
+ if (len == 0)
+ i++;
+ }
+}
+
+/**
+ * gsm_dlci_data_kick - transmit if possible
+ * @dlci: DLCI to kick
+ *
+ * Transmit data from this DLCI if the queue is empty. We can't rely on
+ * a tty wakeup except when we filled the pipe so we need to fire off
+ * new data ourselves in other cases.
+ */
+
+static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&dlci->gsm->tx_lock, flags);
+ /* If we have nothing running then we need to fire up */
+ if (dlci->gsm->tx_bytes == 0)
+ gsm_dlci_data_output(dlci->gsm, dlci);
+ else if (dlci->gsm->tx_bytes < TX_THRESH_LO)
+ gsm_dlci_data_sweep(dlci->gsm);
+ spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
+}
+
+/*
+ * Control message processing
+ */
+
+
+/**
+ * gsm_control_reply - send a response frame to a control
+ * @gsm: gsm channel
+ * @cmd: the command to use
+ * @data: data to follow encoded info
+ * @dlen: length of data
+ *
+ * Encode up and queue a UI/UIH frame containing our response.
+ */
+
+static void gsm_control_reply(struct gsm_mux *gsm, int cmd, u8 *data,
+ int dlen)
+{
+ struct gsm_msg *msg;
+ msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype);
+ msg->data[0] = (cmd & 0xFE) << 1 | EA; /* Clear C/R */
+ msg->data[1] = (dlen << 1) | EA;
+ memcpy(msg->data + 2, data, dlen);
+ gsm_data_queue(gsm->dlci[0], msg);
+}
+
+/**
+ * gsm_process_modem - process received modem status
+ * @tty: virtual tty bound to the DLCI
+ * @dlci: DLCI to affect
+ * @modem: modem bits (full EA)
+ *
+ * Used when a modem control message or line state inline in adaption
+ * layer 2 is processed. Sort out the local modem state and throttles
+ */
+
+static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci,
+ u32 modem)
+{
+ int mlines = 0;
+ u8 brk = modem >> 6;
+
+ /* Flow control/ready to communicate */
+ if (modem & MDM_FC) {
+ /* Need to throttle our output on this device */
+ dlci->constipated = 1;
+ }
+ if (modem & MDM_RTC) {
+ mlines |= TIOCM_DSR | TIOCM_DTR;
+ dlci->constipated = 0;
+ gsm_dlci_data_kick(dlci);
+ }
+ /* Map modem bits */
+ if (modem & MDM_RTR)
+ mlines |= TIOCM_RTS | TIOCM_CTS;
+ if (modem & MDM_IC)
+ mlines |= TIOCM_RI;
+ if (modem & MDM_DV)
+ mlines |= TIOCM_CD;
+
+ /* Carrier drop -> hangup */
+ if (tty) {
+ if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD))
+ if (!(tty->termios->c_cflag & CLOCAL))
+ tty_hangup(tty);
+ if (brk & 0x01)
+ tty_insert_flip_char(tty, 0, TTY_BREAK);
+ }
+ dlci->modem_rx = mlines;
+}
+
+/**
+ * gsm_control_modem - modem status received
+ * @gsm: GSM channel
+ * @data: data following command
+ * @clen: command length
+ *
+ * We have received a modem status control message. This is used by
+ * the GSM mux protocol to pass virtual modem line status and optionally
+ * to indicate break signals. Unpack it, convert to Linux representation
+ * and if need be stuff a break message down the tty.
+ */
+
+static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen)
+{
+ unsigned int addr = 0;
+ unsigned int modem = 0;
+ struct gsm_dlci *dlci;
+ int len = clen;
+ u8 *dp = data;
+ struct tty_struct *tty;
+
+ while (gsm_read_ea(&addr, *dp++) == 0) {
+ len--;
+ if (len == 0)
+ return;
+ }
+ /* Must be at least one byte following the EA */
+ len--;
+ if (len <= 0)
+ return;
+
+ addr >>= 1;
+ /* Closed port, or invalid ? */
+ if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
+ return;
+ dlci = gsm->dlci[addr];
+
+ while (gsm_read_ea(&modem, *dp++) == 0) {
+ len--;
+ if (len == 0)
+ return;
+ }
+ tty = tty_port_tty_get(&dlci->port);
+ gsm_process_modem(tty, dlci, modem);
+ if (tty) {
+ tty_wakeup(tty);
+ tty_kref_put(tty);
+ }
+ gsm_control_reply(gsm, CMD_MSC, data, clen);
+}
+
+/**
+ * gsm_control_rls - remote line status
+ * @gsm: GSM channel
+ * @data: data bytes
+ * @clen: data length
+ *
+ * The modem sends us a two byte message on the control channel whenever
+ * it wishes to send us an error state from the virtual link. Stuff
+ * this into the uplink tty if present
+ */
+
+static void gsm_control_rls(struct gsm_mux *gsm, u8 *data, int clen)
+{
+ struct tty_struct *tty;
+ unsigned int addr = 0 ;
+ u8 bits;
+ int len = clen;
+ u8 *dp = data;
+
+ while (gsm_read_ea(&addr, *dp++) == 0) {
+ len--;
+ if (len == 0)
+ return;
+ }
+ /* Must be at least one byte following ea */
+ len--;
+ if (len <= 0)
+ return;
+ addr >>= 1;
+ /* Closed port, or invalid ? */
+ if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL)
+ return;
+ /* No error ? */
+ bits = *dp;
+ if ((bits & 1) == 0)
+ return;
+ /* See if we have an uplink tty */
+ tty = tty_port_tty_get(&gsm->dlci[addr]->port);
+
+ if (tty) {
+ if (bits & 2)
+ tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+ if (bits & 4)
+ tty_insert_flip_char(tty, 0, TTY_PARITY);
+ if (bits & 8)
+ tty_insert_flip_char(tty, 0, TTY_FRAME);
+ tty_flip_buffer_push(tty);
+ tty_kref_put(tty);
+ }
+ gsm_control_reply(gsm, CMD_RLS, data, clen);
+}
+
+static void gsm_dlci_begin_close(struct gsm_dlci *dlci);
+
+/**
+ * gsm_control_message - DLCI 0 control processing
+ * @gsm: our GSM mux
+ * @command: the command EA
+ * @data: data beyond the command/length EAs
+ * @clen: length
+ *
+ * Input processor for control messages from the other end of the link.
+ * Processes the incoming request and queues a response frame or an
+ * NSC response if not supported
+ */
+
+static void gsm_control_message(struct gsm_mux *gsm, unsigned int command,
+ u8 *data, int clen)
+{
+ u8 buf[1];
+ switch (command) {
+ case CMD_CLD: {
+ struct gsm_dlci *dlci = gsm->dlci[0];
+ /* Modem wishes to close down */
+ if (dlci) {
+ dlci->dead = 1;
+ gsm->dead = 1;
+ gsm_dlci_begin_close(dlci);
+ }
+ }
+ break;
+ case CMD_TEST:
+ /* Modem wishes to test, reply with the data */
+ gsm_control_reply(gsm, CMD_TEST, data, clen);
+ break;
+ case CMD_FCON:
+ /* Modem wants us to STFU */
+ gsm->constipated = 1;
+ gsm_control_reply(gsm, CMD_FCON, NULL, 0);
+ break;
+ case CMD_FCOFF:
+ /* Modem can accept data again */
+ gsm->constipated = 0;
+ gsm_control_reply(gsm, CMD_FCOFF, NULL, 0);
+ /* Kick the link in case it is idling */
+ gsm_data_kick(gsm);
+ break;
+ case CMD_MSC:
+ /* Out of band modem line change indicator for a DLCI */
+ gsm_control_modem(gsm, data, clen);
+ break;
+ case CMD_RLS:
+ /* Out of band error reception for a DLCI */
+ gsm_control_rls(gsm, data, clen);
+ break;
+ case CMD_PSC:
+ /* Modem wishes to enter power saving state */
+ gsm_control_reply(gsm, CMD_PSC, NULL, 0);
+ break;
+ /* Optional unsupported commands */
+ case CMD_PN: /* Parameter negotiation */
+ case CMD_RPN: /* Remote port negotation */
+ case CMD_SNC: /* Service negotation command */
+ default:
+ /* Reply to bad commands with an NSC */
+ buf[0] = command;
+ gsm_control_reply(gsm, CMD_NSC, buf, 1);
+ break;
+ }
+}
+
+/**
+ * gsm_control_response - process a response to our control
+ * @gsm: our GSM mux
+ * @command: the command (response) EA
+ * @data: data beyond the command/length EA
+ * @clen: length
+ *
+ * Process a response to an outstanding command. We only allow a single
+ * control message in flight so this is fairly easy. All the clean up
+ * is done by the caller, we just update the fields, flag it as done
+ * and return
+ */
+
+static void gsm_control_response(struct gsm_mux *gsm, unsigned int command,
+ u8 *data, int clen)
+{
+ struct gsm_control *ctrl;
+ unsigned long flags;
+
+ spin_lock_irqsave(&gsm->control_lock, flags);
+
+ ctrl = gsm->pending_cmd;
+ /* Does the reply match our command */
+ command |= 1;
+ if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) {
+ /* Our command was replied to, kill the retry timer */
+ del_timer(&gsm->t2_timer);
+ gsm->pending_cmd = NULL;
+ /* Rejected by the other end */
+ if (command == CMD_NSC)
+ ctrl->error = -EOPNOTSUPP;
+ ctrl->done = 1;
+ wake_up(&gsm->event);
+ }
+ spin_unlock_irqrestore(&gsm->control_lock, flags);
+}
+
+/**
+ * gsm_control_transmit - send control packet
+ * @gsm: gsm mux
+ * @ctrl: frame to send
+ *
+ * Send out a pending control command (called under control lock)
+ */
+
+static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl)
+{
+ struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 1,
+ gsm->ftype|PF);
+ if (msg == NULL)
+ return;
+ msg->data[0] = (ctrl->cmd << 1) | 2 | EA; /* command */
+ memcpy(msg->data + 1, ctrl->data, ctrl->len);
+ gsm_data_queue(gsm->dlci[0], msg);
+}
+
+/**
+ * gsm_control_retransmit - retransmit a control frame
+ * @data: pointer to our gsm object
+ *
+ * Called off the T2 timer expiry in order to retransmit control frames
+ * that have been lost in the system somewhere. The control_lock protects
+ * us from colliding with another sender or a receive completion event.
+ * In that situation the timer may still occur in a small window but
+ * gsm->pending_cmd will be NULL and we just let the timer expire.
+ */
+
+static void gsm_control_retransmit(unsigned long data)
+{
+ struct gsm_mux *gsm = (struct gsm_mux *)data;
+ struct gsm_control *ctrl;
+ unsigned long flags;
+ spin_lock_irqsave(&gsm->control_lock, flags);
+ ctrl = gsm->pending_cmd;
+ if (ctrl) {
+ gsm->cretries--;
+ if (gsm->cretries == 0) {
+ gsm->pending_cmd = NULL;
+ ctrl->error = -ETIMEDOUT;
+ ctrl->done = 1;
+ spin_unlock_irqrestore(&gsm->control_lock, flags);
+ wake_up(&gsm->event);
+ return;
+ }
+ gsm_control_transmit(gsm, ctrl);
+ mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
+ }
+ spin_unlock_irqrestore(&gsm->control_lock, flags);
+}
+
+/**
+ * gsm_control_send - send a control frame on DLCI 0
+ * @gsm: the GSM channel
+ * @command: command to send including CR bit
+ * @data: bytes of data (must be kmalloced)
+ * @len: length of the block to send
+ *
+ * Queue and dispatch a control command. Only one command can be
+ * active at a time. In theory more can be outstanding but the matching
+ * gets really complicated so for now stick to one outstanding.
+ */
+
+static struct gsm_control *gsm_control_send(struct gsm_mux *gsm,
+ unsigned int command, u8 *data, int clen)
+{
+ struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control),
+ GFP_KERNEL);
+ unsigned long flags;
+ if (ctrl == NULL)
+ return NULL;
+retry:
+ wait_event(gsm->event, gsm->pending_cmd == NULL);
+ spin_lock_irqsave(&gsm->control_lock, flags);
+ if (gsm->pending_cmd != NULL) {
+ spin_unlock_irqrestore(&gsm->control_lock, flags);
+ goto retry;
+ }
+ ctrl->cmd = command;
+ ctrl->data = data;
+ ctrl->len = clen;
+ gsm->pending_cmd = ctrl;
+ gsm->cretries = gsm->n2;
+ mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100);
+ gsm_control_transmit(gsm, ctrl);
+ spin_unlock_irqrestore(&gsm->control_lock, flags);
+ return ctrl;
+}
+
+/**
+ * gsm_control_wait - wait for a control to finish
+ * @gsm: GSM mux
+ * @control: control we are waiting on
+ *
+ * Waits for the control to complete or time out. Frees any used
+ * resources and returns 0 for success, or an error if the remote
+ * rejected or ignored the request.
+ */
+
+static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control)
+{
+ int err;
+ wait_event(gsm->event, control->done == 1);
+ err = control->error;
+ kfree(control);
+ return err;
+}
+
+
+/*
+ * DLCI level handling: Needs krefs
+ */
+
+/*
+ * State transitions and timers
+ */
+
+/**
+ * gsm_dlci_close - a DLCI has closed
+ * @dlci: DLCI that closed
+ *
+ * Perform processing when moving a DLCI into closed state. If there
+ * is an attached tty this is hung up
+ */
+
+static void gsm_dlci_close(struct gsm_dlci *dlci)
+{
+ del_timer(&dlci->t1);
+ if (debug & 8)
+ printk("DLCI %d goes closed.\n", dlci->addr);
+ dlci->state = DLCI_CLOSED;
+ if (dlci->addr != 0) {
+ struct tty_struct *tty = tty_port_tty_get(&dlci->port);
+ if (tty) {
+ tty_hangup(tty);
+ tty_kref_put(tty);
+ }
+ kfifo_reset(dlci->fifo);
+ } else
+ dlci->gsm->dead = 1;
+ wake_up(&dlci->gsm->event);
+ /* A DLCI 0 close is a MUX termination so we need to kick that
+ back to userspace somehow */
+}
+
+/**
+ * gsm_dlci_open - a DLCI has opened
+ * @dlci: DLCI that opened
+ *
+ * Perform processing when moving a DLCI into open state.
+ */
+
+static void gsm_dlci_open(struct gsm_dlci *dlci)
+{
+ /* Note that SABM UA .. SABM UA first UA lost can mean that we go
+ open -> open */
+ del_timer(&dlci->t1);
+ /* This will let a tty open continue */
+ dlci->state = DLCI_OPEN;
+ if (debug & 8)
+ printk("DLCI %d goes open.\n", dlci->addr);
+ wake_up(&dlci->gsm->event);
+}
+
+/**
+ * gsm_dlci_t1 - T1 timer expiry
+ * @dlci: DLCI that opened
+ *
+ * The T1 timer handles retransmits of control frames (essentially of
+ * SABM and DISC). We resend the command until the retry count runs out
+ * in which case an opening port goes back to closed and a closing port
+ * is simply put into closed state (any further frames from the other
+ * end will get a DM response)
+ */
+
+static void gsm_dlci_t1(unsigned long data)
+{
+ struct gsm_dlci *dlci = (struct gsm_dlci *)data;
+ struct gsm_mux *gsm = dlci->gsm;
+
+ switch (dlci->state) {
+ case DLCI_OPENING:
+ dlci->retries--;
+ if (dlci->retries) {
+ gsm_command(dlci->gsm, dlci->addr, SABM|PF);
+ mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+ } else
+ gsm_dlci_close(dlci);
+ break;
+ case DLCI_CLOSING:
+ dlci->retries--;
+ if (dlci->retries) {
+ gsm_command(dlci->gsm, dlci->addr, DISC|PF);
+ mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+ } else
+ gsm_dlci_close(dlci);
+ break;
+ }
+}
+
+/**
+ * gsm_dlci_begin_open - start channel open procedure
+ * @dlci: DLCI to open
+ *
+ * Commence opening a DLCI from the Linux side. We issue SABM messages
+ * to the modem which should then reply with a UA, at which point we
+ * will move into open state. Opening is done asynchronously with retry
+ * running off timers and the responses.
+ */
+
+static void gsm_dlci_begin_open(struct gsm_dlci *dlci)
+{
+ struct gsm_mux *gsm = dlci->gsm;
+ if (dlci->state == DLCI_OPEN || dlci->state == DLCI_OPENING)
+ return;
+ dlci->retries = gsm->n2;
+ dlci->state = DLCI_OPENING;
+ gsm_command(dlci->gsm, dlci->addr, SABM|PF);
+ mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+}
+
+/**
+ * gsm_dlci_begin_close - start channel open procedure
+ * @dlci: DLCI to open
+ *
+ * Commence closing a DLCI from the Linux side. We issue DISC messages
+ * to the modem which should then reply with a UA, at which point we
+ * will move into closed state. Closing is done asynchronously with retry
+ * off timers. We may also receive a DM reply from the other end which
+ * indicates the channel was already closed.
+ */
+
+static void gsm_dlci_begin_close(struct gsm_dlci *dlci)
+{
+ struct gsm_mux *gsm = dlci->gsm;
+ if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING)
+ return;
+ dlci->retries = gsm->n2;
+ dlci->state = DLCI_CLOSING;
+ gsm_command(dlci->gsm, dlci->addr, DISC|PF);
+ mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+}
+
+/**
+ * gsm_dlci_data - data arrived
+ * @dlci: channel
+ * @data: block of bytes received
+ * @len: length of received block
+ *
+ * A UI or UIH frame has arrived which contains data for a channel
+ * other than the control channel. If the relevant virtual tty is
+ * open we shovel the bits down it, if not we drop them.
+ */
+
+static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len)
+{
+ /* krefs .. */
+ struct tty_port *port = &dlci->port;
+ struct tty_struct *tty = tty_port_tty_get(port);
+ unsigned int modem = 0;
+
+ if (debug & 16)
+ printk("%d bytes for tty %p\n", len, tty);
+ if (tty) {
+ switch (dlci->adaption) {
+ /* Unsupported types */
+ /* Packetised interruptible data */
+ case 4:
+ break;
+ /* Packetised uininterruptible voice/data */
+ case 3:
+ break;
+ /* Asynchronous serial with line state in each frame */
+ case 2:
+ while (gsm_read_ea(&modem, *data++) == 0) {
+ len--;
+ if (len == 0)
+ return;
+ }
+ gsm_process_modem(tty, dlci, modem);
+ /* Line state will go via DLCI 0 controls only */
+ case 1:
+ default:
+ tty_insert_flip_string(tty, data, len);
+ tty_flip_buffer_push(tty);
+ }
+ tty_kref_put(tty);
+ }
+}
+
+/**
+ * gsm_dlci_control - data arrived on control channel
+ * @dlci: channel
+ * @data: block of bytes received
+ * @len: length of received block
+ *
+ * A UI or UIH frame has arrived which contains data for DLCI 0 the
+ * control channel. This should contain a command EA followed by
+ * control data bytes. The command EA contains a command/response bit
+ * and we divide up the work accordingly.
+ */
+
+static void gsm_dlci_command(struct gsm_dlci *dlci, u8 *data, int len)
+{
+ /* See what command is involved */
+ unsigned int command = 0;
+ while (len-- > 0) {
+ if (gsm_read_ea(&command, *data++) == 1) {
+ int clen = *data++;
+ len--;
+ /* FIXME: this is properly an EA */
+ clen >>= 1;
+ /* Malformed command ? */
+ if (clen > len)
+ return;
+ if (command & 1)
+ gsm_control_message(dlci->gsm, command,
+ data, clen);
+ else
+ gsm_control_response(dlci->gsm, command,
+ data, clen);
+ return;
+ }
+ }
+}
+
+/*
+ * Allocate/Free DLCI channels
+ */
+
+/**
+ * gsm_dlci_alloc - allocate a DLCI
+ * @gsm: GSM mux
+ * @addr: address of the DLCI
+ *
+ * Allocate and install a new DLCI object into the GSM mux.
+ *
+ * FIXME: review locking races
+ */
+
+static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr)
+{
+ struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC);
+ if (dlci == NULL)
+ return NULL;
+ spin_lock_init(&dlci->lock);
+ dlci->fifo = &dlci->_fifo;
+ if (kfifo_alloc(&dlci->_fifo, 4096, GFP_KERNEL) < 0) {
+ kfree(dlci);
+ return NULL;
+ }
+
+ skb_queue_head_init(&dlci->skb_list);
+ init_timer(&dlci->t1);
+ dlci->t1.function = gsm_dlci_t1;
+ dlci->t1.data = (unsigned long)dlci;
+ tty_port_init(&dlci->port);
+ dlci->port.ops = &gsm_port_ops;
+ dlci->gsm = gsm;
+ dlci->addr = addr;
+ dlci->adaption = gsm->adaption;
+ dlci->state = DLCI_CLOSED;
+ if (addr)
+ dlci->data = gsm_dlci_data;
+ else
+ dlci->data = gsm_dlci_command;
+ gsm->dlci[addr] = dlci;
+ return dlci;
+}
+
+/**
+ * gsm_dlci_free - release DLCI
+ * @dlci: DLCI to destroy
+ *
+ * Free up a DLCI. Currently to keep the lifetime rules sane we only
+ * clean up DLCI objects when the MUX closes rather than as the port
+ * is closed down on both the tty and mux levels.
+ *
+ * Can sleep.
+ */
+static void gsm_dlci_free(struct gsm_dlci *dlci)
+{
+ struct tty_struct *tty = tty_port_tty_get(&dlci->port);
+ if (tty) {
+ tty_vhangup(tty);
+ tty_kref_put(tty);
+ }
+ del_timer_sync(&dlci->t1);
+ dlci->gsm->dlci[dlci->addr] = NULL;
+ kfifo_free(dlci->fifo);
+ kfree(dlci);
+}
+
+
+/*
+ * LAPBish link layer logic
+ */
+
+/**
+ * gsm_queue - a GSM frame is ready to process
+ * @gsm: pointer to our gsm mux
+ *
+ * At this point in time a frame has arrived and been demangled from
+ * the line encoding. All the differences between the encodings have
+ * been handled below us and the frame is unpacked into the structures.
+ * The fcs holds the header FCS but any data FCS must be added here.
+ */
+
+static void gsm_queue(struct gsm_mux *gsm)
+{
+ struct gsm_dlci *dlci;
+ u8 cr;
+ int address;
+ /* We have to sneak a look at the packet body to do the FCS.
+ A somewhat layering violation in the spec */
+
+ if ((gsm->control & ~PF) == UI)
+ gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len);
+ if (gsm->fcs != GOOD_FCS) {
+ gsm->bad_fcs++;
+ if (debug & 4)
+ printk("BAD FCS %02x\n", gsm->fcs);
+ return;
+ }
+ address = gsm->address >> 1;
+ if (address >= NUM_DLCI)
+ goto invalid;
+
+ cr = gsm->address & 1; /* C/R bit */
+
+ gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len);
+
+ cr ^= 1 - gsm->initiator; /* Flip so 1 always means command */
+ dlci = gsm->dlci[address];
+
+ switch (gsm->control) {
+ case SABM|PF:
+ if (cr == 0)
+ goto invalid;
+ if (dlci == NULL)
+ dlci = gsm_dlci_alloc(gsm, address);
+ if (dlci == NULL)
+ return;
+ if (dlci->dead)
+ gsm_response(gsm, address, DM);
+ else {
+ gsm_response(gsm, address, UA);
+ gsm_dlci_open(dlci);
+ }
+ break;
+ case DISC|PF:
+ if (cr == 0)
+ goto invalid;
+ if (dlci == NULL || dlci->state == DLCI_CLOSED) {
+ gsm_response(gsm, address, DM);
+ return;
+ }
+ /* Real close complete */
+ gsm_response(gsm, address, UA);
+ gsm_dlci_close(dlci);
+ break;
+ case UA:
+ case UA|PF:
+ if (cr == 0 || dlci == NULL)
+ break;
+ switch (dlci->state) {
+ case DLCI_CLOSING:
+ gsm_dlci_close(dlci);
+ break;
+ case DLCI_OPENING:
+ gsm_dlci_open(dlci);
+ break;
+ }
+ break;
+ case DM: /* DM can be valid unsolicited */
+ case DM|PF:
+ if (cr)
+ goto invalid;
+ if (dlci == NULL)
+ return;
+ gsm_dlci_close(dlci);
+ break;
+ case UI:
+ case UI|PF:
+ case UIH:
+ case UIH|PF:
+#if 0
+ if (cr)
+ goto invalid;
+#endif
+ if (dlci == NULL || dlci->state != DLCI_OPEN) {
+ gsm_command(gsm, address, DM|PF);
+ return;
+ }
+ dlci->data(dlci, gsm->buf, gsm->len);
+ break;
+ default:
+ goto invalid;
+ }
+ return;
+invalid:
+ gsm->malformed++;
+ return;
+}
+
+
+/**
+ * gsm0_receive - perform processing for non-transparency
+ * @gsm: gsm data for this ldisc instance
+ * @c: character
+ *
+ * Receive bytes in gsm mode 0
+ */
+
+static void gsm0_receive(struct gsm_mux *gsm, unsigned char c)
+{
+ switch (gsm->state) {
+ case GSM_SEARCH: /* SOF marker */
+ if (c == GSM0_SOF) {
+ gsm->state = GSM_ADDRESS;
+ gsm->address = 0;
+ gsm->len = 0;
+ gsm->fcs = INIT_FCS;
+ }
+ break; /* Address EA */
+ case GSM_ADDRESS:
+ gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+ if (gsm_read_ea(&gsm->address, c))
+ gsm->state = GSM_CONTROL;
+ break;
+ case GSM_CONTROL: /* Control Byte */
+ gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+ gsm->control = c;
+ gsm->state = GSM_LEN;
+ break;
+ case GSM_LEN: /* Length EA */
+ gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+ if (gsm_read_ea(&gsm->len, c)) {
+ if (gsm->len > gsm->mru) {
+ gsm->bad_size++;
+ gsm->state = GSM_SEARCH;
+ break;
+ }
+ gsm->count = 0;
+ gsm->state = GSM_DATA;
+ }
+ break;
+ case GSM_DATA: /* Data */
+ gsm->buf[gsm->count++] = c;
+ if (gsm->count == gsm->len)
+ gsm->state = GSM_FCS;
+ break;
+ case GSM_FCS: /* FCS follows the packet */
+ gsm->fcs = c;
+ gsm_queue(gsm);
+ /* And then back for the next frame */
+ gsm->state = GSM_SEARCH;
+ break;
+ }
+}
+
+/**
+ * gsm0_receive - perform processing for non-transparency
+ * @gsm: gsm data for this ldisc instance
+ * @c: character
+ *
+ * Receive bytes in mode 1 (Advanced option)
+ */
+
+static void gsm1_receive(struct gsm_mux *gsm, unsigned char c)
+{
+ if (c == GSM1_SOF) {
+ /* EOF is only valid in frame if we have got to the data state
+ and received at least one byte (the FCS) */
+ if (gsm->state == GSM_DATA && gsm->count) {
+ /* Extract the FCS */
+ gsm->count--;
+ gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]);
+ gsm->len = gsm->count;
+ gsm_queue(gsm);
+ gsm->state = GSM_START;
+ return;
+ }
+ /* Any partial frame was a runt so go back to start */
+ if (gsm->state != GSM_START) {
+ gsm->malformed++;
+ gsm->state = GSM_START;
+ }
+ /* A SOF in GSM_START means we are still reading idling or
+ framing bytes */
+ return;
+ }
+
+ if (c == GSM1_ESCAPE) {
+ gsm->escape = 1;
+ return;
+ }
+
+ /* Only an unescaped SOF gets us out of GSM search */
+ if (gsm->state == GSM_SEARCH)
+ return;
+
+ if (gsm->escape) {
+ c ^= GSM1_ESCAPE_BITS;
+ gsm->escape = 0;
+ }
+ switch (gsm->state) {
+ case GSM_START: /* First byte after SOF */
+ gsm->address = 0;
+ gsm->state = GSM_ADDRESS;
+ gsm->fcs = INIT_FCS;
+ /* Drop through */
+ case GSM_ADDRESS: /* Address continuation */
+ gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+ if (gsm_read_ea(&gsm->address, c))
+ gsm->state = GSM_CONTROL;
+ break;
+ case GSM_CONTROL: /* Control Byte */
+ gsm->fcs = gsm_fcs_add(gsm->fcs, c);
+ gsm->control = c;
+ gsm->count = 0;
+ gsm->state = GSM_DATA;
+ break;
+ case GSM_DATA: /* Data */
+ if (gsm->count > gsm->mru ) { /* Allow one for the FCS */
+ gsm->state = GSM_OVERRUN;
+ gsm->bad_size++;
+ } else
+ gsm->buf[gsm->count++] = c;
+ break;
+ case GSM_OVERRUN: /* Over-long - eg a dropped SOF */
+ break;
+ }
+}
+
+/**
+ * gsm_error - handle tty error
+ * @gsm: ldisc data
+ * @data: byte received (may be invalid)
+ * @flag: error received
+ *
+ * Handle an error in the receipt of data for a frame. Currently we just
+ * go back to hunting for a SOF.
+ *
+ * FIXME: better diagnostics ?
+ */
+
+static void gsm_error(struct gsm_mux *gsm,
+ unsigned char data, unsigned char flag)
+{
+ gsm->state = GSM_SEARCH;
+ gsm->io_error++;
+}
+
+/**
+ * gsm_cleanup_mux - generic GSM protocol cleanup
+ * @gsm: our mux
+ *
+ * Clean up the bits of the mux which are the same for all framing
+ * protocols. Remove the mux from the mux table, stop all the timers
+ * and then shut down each device hanging up the channels as we go.
+ */
+
+void gsm_cleanup_mux(struct gsm_mux *gsm)
+{
+ int i;
+ struct gsm_dlci *dlci = gsm->dlci[0];
+ struct gsm_msg *txq;
+
+ gsm->dead = 1;
+
+ spin_lock(&gsm_mux_lock);
+ for (i = 0; i < MAX_MUX; i++) {
+ if (gsm_mux[i] == gsm) {
+ gsm_mux[i] = NULL;
+ break;
+ }
+ }
+ spin_unlock(&gsm_mux_lock);
+ WARN_ON(i == MAX_MUX);
+
+ del_timer_sync(&gsm->t2_timer);
+ /* Now we are sure T2 has stopped */
+ if (dlci) {
+ dlci->dead = 1;
+ gsm_dlci_begin_close(dlci);
+ wait_event_interruptible(gsm->event,
+ dlci->state == DLCI_CLOSED);
+ }
+ /* Free up any link layer users */
+ for (i = 0; i < NUM_DLCI; i++)
+ if (gsm->dlci[i])
+ gsm_dlci_free(gsm->dlci[i]);
+ /* Now wipe the queues */
+ for (txq = gsm->tx_head; txq != NULL; txq = gsm->tx_head) {
+ gsm->tx_head = txq->next;
+ kfree(txq);
+ }
+ gsm->tx_tail = NULL;
+}
+EXPORT_SYMBOL_GPL(gsm_cleanup_mux);
+
+/**
+ * gsm_activate_mux - generic GSM setup
+ * @gsm: our mux
+ *
+ * Set up the bits of the mux which are the same for all framing
+ * protocols. Add the mux to the mux table so it can be opened and
+ * finally kick off connecting to DLCI 0 on the modem.
+ */
+
+int gsm_activate_mux(struct gsm_mux *gsm)
+{
+ struct gsm_dlci *dlci;
+ int i = 0;
+
+ init_timer(&gsm->t2_timer);
+ gsm->t2_timer.function = gsm_control_retransmit;
+ gsm->t2_timer.data = (unsigned long)gsm;
+ init_waitqueue_head(&gsm->event);
+ spin_lock_init(&gsm->control_lock);
+ spin_lock_init(&gsm->tx_lock);
+
+ if (gsm->encoding == 0)
+ gsm->receive = gsm0_receive;
+ else
+ gsm->receive = gsm1_receive;
+ gsm->error = gsm_error;
+
+ spin_lock(&gsm_mux_lock);
+ for (i = 0; i < MAX_MUX; i++) {
+ if (gsm_mux[i] == NULL) {
+ gsm_mux[i] = gsm;
+ break;
+ }
+ }
+ spin_unlock(&gsm_mux_lock);
+ if (i == MAX_MUX)
+ return -EBUSY;
+
+ dlci = gsm_dlci_alloc(gsm, 0);
+ if (dlci == NULL)
+ return -ENOMEM;
+ gsm->dead = 0; /* Tty opens are now permissible */
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gsm_activate_mux);
+
+/**
+ * gsm_free_mux - free up a mux
+ * @mux: mux to free
+ *
+ * Dispose of allocated resources for a dead mux. No refcounting
+ * at present so the mux must be truely dead.
+ */
+void gsm_free_mux(struct gsm_mux *gsm)
+{
+ kfree(gsm->txframe);
+ kfree(gsm->buf);
+ kfree(gsm);
+}
+EXPORT_SYMBOL_GPL(gsm_free_mux);
+
+/**
+ * gsm_alloc_mux - allocate a mux
+ *
+ * Creates a new mux ready for activation.
+ */
+
+struct gsm_mux *gsm_alloc_mux(void)
+{
+ struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL);
+ if (gsm == NULL)
+ return NULL;
+ gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL);
+ if (gsm->buf == NULL) {
+ kfree(gsm);
+ return NULL;
+ }
+ gsm->txframe = kmalloc(2 * MAX_MRU + 2, GFP_KERNEL);
+ if (gsm->txframe == NULL) {
+ kfree(gsm->buf);
+ kfree(gsm);
+ return NULL;
+ }
+ spin_lock_init(&gsm->lock);
+
+ gsm->t1 = T1;
+ gsm->t2 = T2;
+ gsm->n2 = N2;
+ gsm->ftype = UIH;
+ gsm->initiator = 0;
+ gsm->adaption = 1;
+ gsm->encoding = 1;
+ gsm->mru = 64; /* Default to encoding 1 so these should be 64 */
+ gsm->mtu = 64;
+ gsm->dead = 1; /* Avoid early tty opens */
+
+ return gsm;
+}
+EXPORT_SYMBOL_GPL(gsm_alloc_mux);
+
+
+
+
+/**
+ * gsmld_output - write to link
+ * @gsm: our mux
+ * @data: bytes to output
+ * @len: size
+ *
+ * Write a block of data from the GSM mux to the data channel. This
+ * will eventually be serialized from above but at the moment isn't.
+ */
+
+static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
+{
+ if (tty_write_room(gsm->tty) < len) {
+ set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags);
+ return -ENOSPC;
+ }
+ if (debug & 4) {
+ printk("-->%d bytes out\n", len);
+ hex_packet(data, len);
+ }
+ gsm->tty->ops->write(gsm->tty, data, len);
+ return len;
+}
+
+/**
+ * gsmld_attach_gsm - mode set up
+ * @tty: our tty structure
+ * @gsm: our mux
+ *
+ * Set up the MUX for basic mode and commence connecting to the
+ * modem. Currently called from the line discipline set up but
+ * will need moving to an ioctl path.
+ */
+
+static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
+{
+ int ret;
+
+ gsm->tty = tty_kref_get(tty);
+ gsm->output = gsmld_output;
+ ret = gsm_activate_mux(gsm);
+ if (ret != 0)
+ tty_kref_put(gsm->tty);
+ return ret;
+}
+
+
+/**
+ * gsmld_detach_gsm - stop doing 0710 mux
+ * @tty: tty atttached to the mux
+ * @gsm: mux
+ *
+ * Shutdown and then clean up the resources used by the line discipline
+ */
+
+static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
+{
+ WARN_ON(tty != gsm->tty);
+ gsm_cleanup_mux(gsm);
+ tty_kref_put(gsm->tty);
+ gsm->tty = NULL;
+}
+
+static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+ char *fp, int count)
+{
+ struct gsm_mux *gsm = tty->disc_data;
+ const unsigned char *dp;
+ char *f;
+ int i;
+ char buf[64];
+ char flags;
+
+ if (debug & 4) {
+ printk("Inbytes %dd\n", count);
+ hex_packet(cp, count);
+ }
+
+ for (i = count, dp = cp, f = fp; i; i--, dp++) {
+ flags = *f++;
+ switch (flags) {
+ case TTY_NORMAL:
+ gsm->receive(gsm, *dp);
+ break;
+ case TTY_OVERRUN:
+ case TTY_BREAK:
+ case TTY_PARITY:
+ case TTY_FRAME:
+ gsm->error(gsm, *dp, flags);
+ break;
+ default:
+ printk(KERN_ERR "%s: unknown flag %d\n",
+ tty_name(tty, buf), flags);
+ break;
+ }
+ }
+ /* FASYNC if needed ? */
+ /* If clogged call tty_throttle(tty); */
+}
+
+/**
+ * gsmld_chars_in_buffer - report available bytes
+ * @tty: tty device
+ *
+ * Report the number of characters buffered to be delivered to user
+ * at this instant in time.
+ *
+ * Locking: gsm lock
+ */
+
+static ssize_t gsmld_chars_in_buffer(struct tty_struct *tty)
+{
+ return 0;
+}
+
+/**
+ * gsmld_flush_buffer - clean input queue
+ * @tty: terminal device
+ *
+ * Flush the input buffer. Called when the line discipline is
+ * being closed, when the tty layer wants the buffer flushed (eg
+ * at hangup).
+ */
+
+static void gsmld_flush_buffer(struct tty_struct *tty)
+{
+}
+
+/**
+ * gsmld_close - close the ldisc for this tty
+ * @tty: device
+ *
+ * Called from the terminal layer when this line discipline is
+ * being shut down, either because of a close or becsuse of a
+ * discipline change. The function will not be called while other
+ * ldisc methods are in progress.
+ */
+
+static void gsmld_close(struct tty_struct *tty)
+{
+ struct gsm_mux *gsm = tty->disc_data;
+
+ gsmld_detach_gsm(tty, gsm);
+
+ gsmld_flush_buffer(tty);
+ /* Do other clean up here */
+ gsm_free_mux(gsm);
+}
+
+/**
+ * gsmld_open - open an ldisc
+ * @tty: terminal to open
+ *
+ * Called when this line discipline is being attached to the
+ * terminal device. Can sleep. Called serialized so that no
+ * other events will occur in parallel. No further open will occur
+ * until a close.
+ */
+
+static int gsmld_open(struct tty_struct *tty)
+{
+ struct gsm_mux *gsm;
+
+ if (tty->ops->write == NULL)
+ return -EINVAL;
+
+ /* Attach our ldisc data */
+ gsm = gsm_alloc_mux();
+ if (gsm == NULL)
+ return -ENOMEM;
+
+ tty->disc_data = gsm;
+ tty->receive_room = 65536;
+
+ /* Attach the initial passive connection */
+ gsm->encoding = 1;
+ return gsmld_attach_gsm(tty, gsm);
+}
+
+/**
+ * gsmld_write_wakeup - asynchronous I/O notifier
+ * @tty: tty device
+ *
+ * Required for the ptys, serial driver etc. since processes
+ * that attach themselves to the master and rely on ASYNC
+ * IO must be woken up
+ */
+
+static void gsmld_write_wakeup(struct tty_struct *tty)
+{
+ struct gsm_mux *gsm = tty->disc_data;
+ unsigned long flags;
+
+ /* Queue poll */
+ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+ gsm_data_kick(gsm);
+ if (gsm->tx_bytes < TX_THRESH_LO) {
+ spin_lock_irqsave(&gsm->tx_lock, flags);
+ gsm_dlci_data_sweep(gsm);
+ spin_unlock_irqrestore(&gsm->tx_lock, flags);
+ }
+}
+
+/**
+ * gsmld_read - read function for tty
+ * @tty: tty device
+ * @file: file object
+ * @buf: userspace buffer pointer
+ * @nr: size of I/O
+ *
+ * Perform reads for the line discipline. We are guaranteed that the
+ * line discipline will not be closed under us but we may get multiple
+ * parallel readers and must handle this ourselves. We may also get
+ * a hangup. Always called in user context, may sleep.
+ *
+ * This code must be sure never to sleep through a hangup.
+ */
+
+static ssize_t gsmld_read(struct tty_struct *tty, struct file *file,
+ unsigned char __user *buf, size_t nr)
+{
+ return -EOPNOTSUPP;
+}
+
+/**
+ * gsmld_write - write function for tty
+ * @tty: tty device
+ * @file: file object
+ * @buf: userspace buffer pointer
+ * @nr: size of I/O
+ *
+ * Called when the owner of the device wants to send a frame
+ * itself (or some other control data). The data is transferred
+ * as-is and must be properly framed and checksummed as appropriate
+ * by userspace. Frames are either sent whole or not at all as this
+ * avoids pain user side.
+ */
+
+static ssize_t gsmld_write(struct tty_struct *tty, struct file *file,
+ const unsigned char *buf, size_t nr)
+{
+ int space = tty_write_room(tty);
+ if (space >= nr)
+ return tty->ops->write(tty, buf, nr);
+ set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+ return -ENOBUFS;
+}
+
+/**
+ * gsmld_poll - poll method for N_GSM0710
+ * @tty: terminal device
+ * @file: file accessing it
+ * @wait: poll table
+ *
+ * Called when the line discipline is asked to poll() for data or
+ * for special events. This code is not serialized with respect to
+ * other events save open/close.
+ *
+ * This code must be sure never to sleep through a hangup.
+ * Called without the kernel lock held - fine
+ */
+
+static unsigned int gsmld_poll(struct tty_struct *tty, struct file *file,
+ poll_table *wait)
+{
+ unsigned int mask = 0;
+ struct gsm_mux *gsm = tty->disc_data;
+
+ poll_wait(file, &tty->read_wait, wait);
+ poll_wait(file, &tty->write_wait, wait);
+ if (tty_hung_up_p(file))
+ mask |= POLLHUP;
+ if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0)
+ mask |= POLLOUT | POLLWRNORM;
+ if (gsm->dead)
+ mask |= POLLHUP;
+ return mask;
+}
+
+static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm,
+ struct gsm_config *c)
+{
+ int need_close = 0;
+ int need_restart = 0;
+
+ /* Stuff we don't support yet - UI or I frame transport, windowing */
+ if ((c->adaption !=1 && c->adaption != 2) || c->k)
+ return -EOPNOTSUPP;
+ /* Check the MRU/MTU range looks sane */
+ if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8)
+ return -EINVAL;
+ if (c->n2 < 3)
+ return -EINVAL;
+ if (c->encapsulation > 1) /* Basic, advanced, no I */
+ return -EINVAL;
+ if (c->initiator > 1)
+ return -EINVAL;
+ if (c->i == 0 || c->i > 2) /* UIH and UI only */
+ return -EINVAL;
+ /*
+ * See what is needed for reconfiguration
+ */
+
+ /* Timing fields */
+ if (c->t1 != 0 && c->t1 != gsm->t1)
+ need_restart = 1;
+ if (c->t2 != 0 && c->t2 != gsm->t2)
+ need_restart = 1;
+ if (c->encapsulation != gsm->encoding)
+ need_restart = 1;
+ if (c->adaption != gsm->adaption)
+ need_restart = 1;
+ /* Requires care */
+ if (c->initiator != gsm->initiator)
+ need_close = 1;
+ if (c->mru != gsm->mru)
+ need_restart = 1;
+ if (c->mtu != gsm->mtu)
+ need_restart = 1;
+
+ /*
+ * Close down what is needed, restart and initiate the new
+ * configuration
+ */
+
+ if (need_close || need_restart) {
+ gsm_dlci_begin_close(gsm->dlci[0]);
+ /* This will timeout if the link is down due to N2 expiring */
+ wait_event_interruptible(gsm->event,
+ gsm->dlci[0]->state == DLCI_CLOSED);
+ if (signal_pending(current))
+ return -EINTR;
+ }
+ if (need_restart)
+ gsm_cleanup_mux(gsm);
+
+ gsm->initiator = c->initiator;
+ gsm->mru = c->mru;
+ gsm->encoding = c->encapsulation;
+ gsm->adaption = c->adaption;
+
+ if (c->i == 1)
+ gsm->ftype = UIH;
+ else if (c->i == 2)
+ gsm->ftype = UI;
+
+ if (c->t1)
+ gsm->t1 = c->t1;
+ if (c->t2)
+ gsm->t2 = c->t2;
+
+ /* FIXME: We need to separate activation/deactivation from adding
+ and removing from the mux array */
+ if (need_restart)
+ gsm_activate_mux(gsm);
+ if (gsm->initiator && need_close)
+ gsm_dlci_begin_open(gsm->dlci[0]);
+ return 0;
+}
+
+static int gsmld_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct gsm_config c;
+ struct gsm_mux *gsm = tty->disc_data;
+
+ switch (cmd) {
+ case GSMIOC_GETCONF:
+ memset(&c, 0, sizeof(c));
+ c.adaption = gsm->adaption;
+ c.encapsulation = gsm->encoding;
+ c.initiator = gsm->initiator;
+ c.t1 = gsm->t1;
+ c.t2 = gsm->t2;
+ c.t3 = 0; /* Not supported */
+ c.n2 = gsm->n2;
+ if (gsm->ftype == UIH)
+ c.i = 1;
+ else
+ c.i = 2;
+ printk("Ftype %d i %d\n", gsm->ftype, c.i);
+ c.mru = gsm->mru;
+ c.mtu = gsm->mtu;
+ c.k = 0;
+ if (copy_to_user((void *)arg, &c, sizeof(c)))
+ return -EFAULT;
+ return 0;
+ case GSMIOC_SETCONF:
+ if (copy_from_user(&c, (void *)arg, sizeof(c)))
+ return -EFAULT;
+ return gsmld_config(tty, gsm, &c);
+ default:
+ return n_tty_ioctl_helper(tty, file, cmd, arg);
+ }
+}
+
+
+/* Line discipline for real tty */
+struct tty_ldisc_ops tty_ldisc_packet = {
+ .owner = THIS_MODULE,
+ .magic = TTY_LDISC_MAGIC,
+ .name = "n_gsm",
+ .open = gsmld_open,
+ .close = gsmld_close,
+ .flush_buffer = gsmld_flush_buffer,
+ .chars_in_buffer = gsmld_chars_in_buffer,
+ .read = gsmld_read,
+ .write = gsmld_write,
+ .ioctl = gsmld_ioctl,
+ .poll = gsmld_poll,
+ .receive_buf = gsmld_receive_buf,
+ .write_wakeup = gsmld_write_wakeup
+};
+
+/*
+ * Virtual tty side
+ */
+
+#define TX_SIZE 512
+
+static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk)
+{
+ u8 modembits[5];
+ struct gsm_control *ctrl;
+ int len = 2;
+
+ if (brk)
+ len++;
+
+ modembits[0] = len << 1 | EA; /* Data bytes */
+ modembits[1] = dlci->addr << 2 | 3; /* DLCI, EA, 1 */
+ modembits[2] = gsm_encode_modem(dlci) << 1 | EA;
+ if (brk)
+ modembits[3] = brk << 4 | 2 | EA; /* Valid, EA */
+ ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len + 1);
+ if (ctrl == NULL)
+ return -ENOMEM;
+ return gsm_control_wait(dlci->gsm, ctrl);
+}
+
+static int gsm_carrier_raised(struct tty_port *port)
+{
+ struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
+ /* Not yet open so no carrier info */
+ if (dlci->state != DLCI_OPEN)
+ return 0;
+ if (debug & 2)
+ return 1;
+ return dlci->modem_rx & TIOCM_CD;
+}
+
+static void gsm_dtr_rts(struct tty_port *port, int onoff)
+{
+ struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
+ unsigned int modem_tx = dlci->modem_tx;
+ if (onoff)
+ modem_tx |= TIOCM_DTR | TIOCM_RTS;
+ else
+ modem_tx &= ~(TIOCM_DTR | TIOCM_RTS);
+ if (modem_tx != dlci->modem_tx) {
+ dlci->modem_tx = modem_tx;
+ gsmtty_modem_update(dlci, 0);
+ }
+}
+
+static const struct tty_port_operations gsm_port_ops = {
+ .carrier_raised = gsm_carrier_raised,
+ .dtr_rts = gsm_dtr_rts,
+};
+
+
+static int gsmtty_open(struct tty_struct *tty, struct file *filp)
+{
+ struct gsm_mux *gsm;
+ struct gsm_dlci *dlci;
+ struct tty_port *port;
+ unsigned int line = tty->index;
+ unsigned int mux = line >> 6;
+
+ line = line & 0x3F;
+
+ if (mux >= MAX_MUX)
+ return -ENXIO;
+ /* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */
+ if (gsm_mux[mux] == NULL)
+ return -EUNATCH;
+ if (line == 0 || line > 61) /* 62/63 reserved */
+ return -ECHRNG;
+ gsm = gsm_mux[mux];
+ if (gsm->dead)
+ return -EL2HLT;
+ dlci = gsm->dlci[line];
+ if (dlci == NULL)
+ dlci = gsm_dlci_alloc(gsm, line);
+ if (dlci == NULL)
+ return -ENOMEM;
+ port = &dlci->port;
+ port->count++;
+ tty->driver_data = dlci;
+ tty_port_tty_set(port, tty);
+
+ dlci->modem_rx = 0;
+ /* We could in theory open and close before we wait - eg if we get
+ a DM straight back. This is ok as that will have caused a hangup */
+ set_bit(ASYNCB_INITIALIZED, &port->flags);
+ /* Start sending off SABM messages */
+ gsm_dlci_begin_open(dlci);
+ /* And wait for virtual carrier */
+ return tty_port_block_til_ready(port, tty, filp);
+}
+
+static void gsmtty_close(struct tty_struct *tty, struct file *filp)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ if (dlci == NULL)
+ return;
+ if (tty_port_close_start(&dlci->port, tty, filp) == 0)
+ return;
+ gsm_dlci_begin_close(dlci);
+ tty_port_close_end(&dlci->port, tty);
+ tty_port_tty_set(&dlci->port, NULL);
+}
+
+static void gsmtty_hangup(struct tty_struct *tty)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ tty_port_hangup(&dlci->port);
+ gsm_dlci_begin_close(dlci);
+}
+
+static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf,
+ int len)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ /* Stuff the bytes into the fifo queue */
+ int sent = kfifo_in_locked(dlci->fifo, buf, len, &dlci->lock);
+ /* Need to kick the channel */
+ gsm_dlci_data_kick(dlci);
+ return sent;
+}
+
+static int gsmtty_write_room(struct tty_struct *tty)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ return TX_SIZE - kfifo_len(dlci->fifo);
+}
+
+static int gsmtty_chars_in_buffer(struct tty_struct *tty)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ return kfifo_len(dlci->fifo);
+}
+
+static void gsmtty_flush_buffer(struct tty_struct *tty)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ /* Caution needed: If we implement reliable transport classes
+ then the data being transmitted can't simply be junked once
+ it has first hit the stack. Until then we can just blow it
+ away */
+ kfifo_reset(dlci->fifo);
+ /* Need to unhook this DLCI from the transmit queue logic */
+}
+
+static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+ /* The FIFO handles the queue so the kernel will do the right
+ thing waiting on chars_in_buffer before calling us. No work
+ to do here */
+}
+
+static int gsmtty_tiocmget(struct tty_struct *tty, struct file *filp)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ return dlci->modem_rx;
+}
+
+static int gsmtty_tiocmset(struct tty_struct *tty, struct file *filp,
+ unsigned int set, unsigned int clear)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ unsigned int modem_tx = dlci->modem_tx;
+
+ modem_tx &= clear;
+ modem_tx |= set;
+
+ if (modem_tx != dlci->modem_tx) {
+ dlci->modem_tx = modem_tx;
+ return gsmtty_modem_update(dlci, 0);
+ }
+ return 0;
+}
+
+
+static int gsmtty_ioctl(struct tty_struct *tty, struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ return -ENOIOCTLCMD;
+}
+
+static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old)
+{
+ /* For the moment its fixed. In actual fact the speed information
+ for the virtual channel can be propogated in both directions by
+ the RPN control message. This however rapidly gets nasty as we
+ then have to remap modem signals each way according to whether
+ our virtual cable is null modem etc .. */
+ tty_termios_copy_hw(tty->termios, old);
+}
+
+static void gsmtty_throttle(struct tty_struct *tty)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ if (tty->termios->c_cflag & CRTSCTS)
+ dlci->modem_tx &= ~TIOCM_DTR;
+ dlci->throttled = 1;
+ /* Send an MSC with DTR cleared */
+ gsmtty_modem_update(dlci, 0);
+}
+
+static void gsmtty_unthrottle(struct tty_struct *tty)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ if (tty->termios->c_cflag & CRTSCTS)
+ dlci->modem_tx |= TIOCM_DTR;
+ dlci->throttled = 0;
+ /* Send an MSC with DTR set */
+ gsmtty_modem_update(dlci, 0);
+}
+
+static int gsmtty_break_ctl(struct tty_struct *tty, int state)
+{
+ struct gsm_dlci *dlci = tty->driver_data;
+ int encode = 0; /* Off */
+
+ if (state == -1) /* "On indefinitely" - we can't encode this
+ properly */
+ encode = 0x0F;
+ else if (state > 0) {
+ encode = state / 200; /* mS to encoding */
+ if (encode > 0x0F)
+ encode = 0x0F; /* Best effort */
+ }
+ return gsmtty_modem_update(dlci, encode);
+}
+
+static struct tty_driver *gsm_tty_driver;
+
+/* Virtual ttys for the demux */
+static const struct tty_operations gsmtty_ops = {
+ .open = gsmtty_open,
+ .close = gsmtty_close,
+ .write = gsmtty_write,
+ .write_room = gsmtty_write_room,
+ .chars_in_buffer = gsmtty_chars_in_buffer,
+ .flush_buffer = gsmtty_flush_buffer,
+ .ioctl = gsmtty_ioctl,
+ .throttle = gsmtty_throttle,
+ .unthrottle = gsmtty_unthrottle,
+ .set_termios = gsmtty_set_termios,
+ .hangup = gsmtty_hangup,
+ .wait_until_sent = gsmtty_wait_until_sent,
+ .tiocmget = gsmtty_tiocmget,
+ .tiocmset = gsmtty_tiocmset,
+ .break_ctl = gsmtty_break_ctl,
+};
+
+
+
+static int __init gsm_init(void)
+{
+ /* Fill in our line protocol discipline, and register it */
+ int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet);
+ if (status != 0) {
+ printk(KERN_ERR "n_gsm: can't register line discipline (err = %d)\n", status);
+ return status;
+ }
+
+ gsm_tty_driver = alloc_tty_driver(256);
+ if (!gsm_tty_driver) {
+ tty_unregister_ldisc(N_GSM0710);
+ printk(KERN_ERR "gsm_init: tty allocation failed.\n");
+ return -EINVAL;
+ }
+ gsm_tty_driver->owner = THIS_MODULE;
+ gsm_tty_driver->driver_name = "gsmtty";
+ gsm_tty_driver->name = "gsmtty";
+ gsm_tty_driver->major = 0; /* Dynamic */
+ gsm_tty_driver->minor_start = 0;
+ gsm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+ gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL;
+ gsm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV
+ | TTY_DRIVER_HARDWARE_BREAK;
+ gsm_tty_driver->init_termios = tty_std_termios;
+ /* Fixme */
+ gsm_tty_driver->init_termios.c_lflag &= ~ECHO;
+ tty_set_operations(gsm_tty_driver, &gsmtty_ops);
+
+ spin_lock_init(&gsm_mux_lock);
+
+ if (tty_register_driver(gsm_tty_driver)) {
+ put_tty_driver(gsm_tty_driver);
+ tty_unregister_ldisc(N_GSM0710);
+ printk(KERN_ERR "gsm_init: tty registration failed.\n");
+ return -EBUSY;
+ }
+ printk(KERN_INFO "gsm_init: loaded as %d,%d.\n", gsm_tty_driver->major, gsm_tty_driver->minor_start);
+ return 0;
+}
+
+static void __exit gsm_exit(void)
+{
+ int status = tty_unregister_ldisc(N_GSM0710);
+ if (status != 0)
+ printk(KERN_ERR "n_gsm: can't unregister line discipline (err = %d)\n", status);
+ tty_unregister_driver(gsm_tty_driver);
+ put_tty_driver(gsm_tty_driver);
+ printk(KERN_INFO "gsm_init: unloaded.\n");
+}
+
+module_init(gsm_init);
+module_exit(gsm_exit);
+
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_LDISC(N_GSM0710);
--- /dev/null
+/* generic HDLC line discipline for Linux
+ *
+ * Written by Paul Fulghum paulkf@microgate.com
+ * for Microgate Corporation
+ *
+ * Microgate and SyncLink are registered trademarks of Microgate Corporation
+ *
+ * Adapted from ppp.c, written by Michael Callahan <callahan@maths.ox.ac.uk>,
+ * Al Longyear <longyear@netcom.com>,
+ * Paul Mackerras <Paul.Mackerras@cs.anu.edu.au>
+ *
+ * Original release 01/11/99
+ *
+ * This code is released under the GNU General Public License (GPL)
+ *
+ * This module implements the tty line discipline N_HDLC for use with
+ * tty device drivers that support bit-synchronous HDLC communications.
+ *
+ * All HDLC data is frame oriented which means:
+ *
+ * 1. tty write calls represent one complete transmit frame of data
+ * The device driver should accept the complete frame or none of
+ * the frame (busy) in the write method. Each write call should have
+ * a byte count in the range of 2-65535 bytes (2 is min HDLC frame
+ * with 1 addr byte and 1 ctrl byte). The max byte count of 65535
+ * should include any crc bytes required. For example, when using
+ * CCITT CRC32, 4 crc bytes are required, so the maximum size frame
+ * the application may transmit is limited to 65531 bytes. For CCITT
+ * CRC16, the maximum application frame size would be 65533.
+ *
+ *
+ * 2. receive callbacks from the device driver represents
+ * one received frame. The device driver should bypass
+ * the tty flip buffer and call the line discipline receive
+ * callback directly to avoid fragmenting or concatenating
+ * multiple frames into a single receive callback.
+ *
+ * The HDLC line discipline queues the receive frames in separate
+ * buffers so complete receive frames can be returned by the
+ * tty read calls.
+ *
+ * 3. tty read calls returns an entire frame of data or nothing.
+ *
+ * 4. all send and receive data is considered raw. No processing
+ * or translation is performed by the line discipline, regardless
+ * of the tty flags
+ *
+ * 5. When line discipline is queried for the amount of receive
+ * data available (FIOC), 0 is returned if no data available,
+ * otherwise the count of the next available frame is returned.
+ * (instead of the sum of all received frame counts).
+ *
+ * These conventions allow the standard tty programming interface
+ * to be used for synchronous HDLC applications when used with
+ * this line discipline (or another line discipline that is frame
+ * oriented such as N_PPP).
+ *
+ * The SyncLink driver (synclink.c) implements both asynchronous
+ * (using standard line discipline N_TTY) and synchronous HDLC
+ * (using N_HDLC) communications, with the latter using the above
+ * conventions.
+ *
+ * This implementation is very basic and does not maintain
+ * any statistics. The main point is to enforce the raw data
+ * and frame orientation of HDLC communications.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define HDLC_MAGIC 0x239e
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+
+#undef VERSION
+#define VERSION(major,minor,patch) (((((major)<<8)+(minor))<<8)+(patch))
+
+#include <linux/poll.h>
+#include <linux/in.h>
+#include <linux/ioctl.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/smp_lock.h>
+#include <linux/string.h> /* used in new tty drivers */
+#include <linux/signal.h> /* used in new tty drivers */
+#include <linux/if.h>
+#include <linux/bitops.h>
+
+#include <asm/system.h>
+#include <asm/termios.h>
+#include <asm/uaccess.h>
+
+/*
+ * Buffers for individual HDLC frames
+ */
+#define MAX_HDLC_FRAME_SIZE 65535
+#define DEFAULT_RX_BUF_COUNT 10
+#define MAX_RX_BUF_COUNT 60
+#define DEFAULT_TX_BUF_COUNT 3
+
+struct n_hdlc_buf {
+ struct n_hdlc_buf *link;
+ int count;
+ char buf[1];
+};
+
+#define N_HDLC_BUF_SIZE (sizeof(struct n_hdlc_buf) + maxframe)
+
+struct n_hdlc_buf_list {
+ struct n_hdlc_buf *head;
+ struct n_hdlc_buf *tail;
+ int count;
+ spinlock_t spinlock;
+};
+
+/**
+ * struct n_hdlc - per device instance data structure
+ * @magic - magic value for structure
+ * @flags - miscellaneous control flags
+ * @tty - ptr to TTY structure
+ * @backup_tty - TTY to use if tty gets closed
+ * @tbusy - reentrancy flag for tx wakeup code
+ * @woke_up - FIXME: describe this field
+ * @tbuf - currently transmitting tx buffer
+ * @tx_buf_list - list of pending transmit frame buffers
+ * @rx_buf_list - list of received frame buffers
+ * @tx_free_buf_list - list unused transmit frame buffers
+ * @rx_free_buf_list - list unused received frame buffers
+ */
+struct n_hdlc {
+ int magic;
+ __u32 flags;
+ struct tty_struct *tty;
+ struct tty_struct *backup_tty;
+ int tbusy;
+ int woke_up;
+ struct n_hdlc_buf *tbuf;
+ struct n_hdlc_buf_list tx_buf_list;
+ struct n_hdlc_buf_list rx_buf_list;
+ struct n_hdlc_buf_list tx_free_buf_list;
+ struct n_hdlc_buf_list rx_free_buf_list;
+};
+
+/*
+ * HDLC buffer list manipulation functions
+ */
+static void n_hdlc_buf_list_init(struct n_hdlc_buf_list *list);
+static void n_hdlc_buf_put(struct n_hdlc_buf_list *list,
+ struct n_hdlc_buf *buf);
+static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *list);
+
+/* Local functions */
+
+static struct n_hdlc *n_hdlc_alloc (void);
+
+/* debug level can be set by insmod for debugging purposes */
+#define DEBUG_LEVEL_INFO 1
+static int debuglevel;
+
+/* max frame size for memory allocations */
+static int maxframe = 4096;
+
+/* TTY callbacks */
+
+static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
+ __u8 __user *buf, size_t nr);
+static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
+ const unsigned char *buf, size_t nr);
+static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg);
+static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
+ poll_table *wait);
+static int n_hdlc_tty_open(struct tty_struct *tty);
+static void n_hdlc_tty_close(struct tty_struct *tty);
+static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *cp,
+ char *fp, int count);
+static void n_hdlc_tty_wakeup(struct tty_struct *tty);
+
+#define bset(p,b) ((p)[(b) >> 5] |= (1 << ((b) & 0x1f)))
+
+#define tty2n_hdlc(tty) ((struct n_hdlc *) ((tty)->disc_data))
+#define n_hdlc2tty(n_hdlc) ((n_hdlc)->tty)
+
+static void flush_rx_queue(struct tty_struct *tty)
+{
+ struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+ struct n_hdlc_buf *buf;
+
+ while ((buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list)))
+ n_hdlc_buf_put(&n_hdlc->rx_free_buf_list, buf);
+}
+
+static void flush_tx_queue(struct tty_struct *tty)
+{
+ struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+ struct n_hdlc_buf *buf;
+ unsigned long flags;
+
+ while ((buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list)))
+ n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, buf);
+ spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+ if (n_hdlc->tbuf) {
+ n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, n_hdlc->tbuf);
+ n_hdlc->tbuf = NULL;
+ }
+ spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+}
+
+static struct tty_ldisc_ops n_hdlc_ldisc = {
+ .owner = THIS_MODULE,
+ .magic = TTY_LDISC_MAGIC,
+ .name = "hdlc",
+ .open = n_hdlc_tty_open,
+ .close = n_hdlc_tty_close,
+ .read = n_hdlc_tty_read,
+ .write = n_hdlc_tty_write,
+ .ioctl = n_hdlc_tty_ioctl,
+ .poll = n_hdlc_tty_poll,
+ .receive_buf = n_hdlc_tty_receive,
+ .write_wakeup = n_hdlc_tty_wakeup,
+ .flush_buffer = flush_rx_queue,
+};
+
+/**
+ * n_hdlc_release - release an n_hdlc per device line discipline info structure
+ * @n_hdlc - per device line discipline info structure
+ */
+static void n_hdlc_release(struct n_hdlc *n_hdlc)
+{
+ struct tty_struct *tty = n_hdlc2tty (n_hdlc);
+ struct n_hdlc_buf *buf;
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_release() called\n",__FILE__,__LINE__);
+
+ /* Ensure that the n_hdlcd process is not hanging on select()/poll() */
+ wake_up_interruptible (&tty->read_wait);
+ wake_up_interruptible (&tty->write_wait);
+
+ if (tty->disc_data == n_hdlc)
+ tty->disc_data = NULL; /* Break the tty->n_hdlc link */
+
+ /* Release transmit and receive buffers */
+ for(;;) {
+ buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list);
+ if (buf) {
+ kfree(buf);
+ } else
+ break;
+ }
+ for(;;) {
+ buf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list);
+ if (buf) {
+ kfree(buf);
+ } else
+ break;
+ }
+ for(;;) {
+ buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
+ if (buf) {
+ kfree(buf);
+ } else
+ break;
+ }
+ for(;;) {
+ buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
+ if (buf) {
+ kfree(buf);
+ } else
+ break;
+ }
+ kfree(n_hdlc->tbuf);
+ kfree(n_hdlc);
+
+} /* end of n_hdlc_release() */
+
+/**
+ * n_hdlc_tty_close - line discipline close
+ * @tty - pointer to tty info structure
+ *
+ * Called when the line discipline is changed to something
+ * else, the tty is closed, or the tty detects a hangup.
+ */
+static void n_hdlc_tty_close(struct tty_struct *tty)
+{
+ struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_close() called\n",__FILE__,__LINE__);
+
+ if (n_hdlc != NULL) {
+ if (n_hdlc->magic != HDLC_MAGIC) {
+ printk (KERN_WARNING"n_hdlc: trying to close unopened tty!\n");
+ return;
+ }
+#if defined(TTY_NO_WRITE_SPLIT)
+ clear_bit(TTY_NO_WRITE_SPLIT,&tty->flags);
+#endif
+ tty->disc_data = NULL;
+ if (tty == n_hdlc->backup_tty)
+ n_hdlc->backup_tty = NULL;
+ if (tty != n_hdlc->tty)
+ return;
+ if (n_hdlc->backup_tty) {
+ n_hdlc->tty = n_hdlc->backup_tty;
+ } else {
+ n_hdlc_release (n_hdlc);
+ }
+ }
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_close() success\n",__FILE__,__LINE__);
+
+} /* end of n_hdlc_tty_close() */
+
+/**
+ * n_hdlc_tty_open - called when line discipline changed to n_hdlc
+ * @tty - pointer to tty info structure
+ *
+ * Returns 0 if success, otherwise error code
+ */
+static int n_hdlc_tty_open (struct tty_struct *tty)
+{
+ struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_open() called (device=%s)\n",
+ __FILE__,__LINE__,
+ tty->name);
+
+ /* There should not be an existing table for this slot. */
+ if (n_hdlc) {
+ printk (KERN_ERR"n_hdlc_tty_open:tty already associated!\n" );
+ return -EEXIST;
+ }
+
+ n_hdlc = n_hdlc_alloc();
+ if (!n_hdlc) {
+ printk (KERN_ERR "n_hdlc_alloc failed\n");
+ return -ENFILE;
+ }
+
+ tty->disc_data = n_hdlc;
+ n_hdlc->tty = tty;
+ tty->receive_room = 65536;
+
+#if defined(TTY_NO_WRITE_SPLIT)
+ /* change tty_io write() to not split large writes into 8K chunks */
+ set_bit(TTY_NO_WRITE_SPLIT,&tty->flags);
+#endif
+
+ /* flush receive data from driver */
+ tty_driver_flush_buffer(tty);
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_open() success\n",__FILE__,__LINE__);
+
+ return 0;
+
+} /* end of n_tty_hdlc_open() */
+
+/**
+ * n_hdlc_send_frames - send frames on pending send buffer list
+ * @n_hdlc - pointer to ldisc instance data
+ * @tty - pointer to tty instance data
+ *
+ * Send frames on pending send buffer list until the driver does not accept a
+ * frame (busy) this function is called after adding a frame to the send buffer
+ * list and by the tty wakeup callback.
+ */
+static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
+{
+ register int actual;
+ unsigned long flags;
+ struct n_hdlc_buf *tbuf;
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_send_frames() called\n",__FILE__,__LINE__);
+ check_again:
+
+ spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+ if (n_hdlc->tbusy) {
+ n_hdlc->woke_up = 1;
+ spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+ return;
+ }
+ n_hdlc->tbusy = 1;
+ n_hdlc->woke_up = 0;
+ spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+
+ /* get current transmit buffer or get new transmit */
+ /* buffer from list of pending transmit buffers */
+
+ tbuf = n_hdlc->tbuf;
+ if (!tbuf)
+ tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
+
+ while (tbuf) {
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)sending frame %p, count=%d\n",
+ __FILE__,__LINE__,tbuf,tbuf->count);
+
+ /* Send the next block of data to device */
+ tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
+ actual = tty->ops->write(tty, tbuf->buf, tbuf->count);
+
+ /* rollback was possible and has been done */
+ if (actual == -ERESTARTSYS) {
+ n_hdlc->tbuf = tbuf;
+ break;
+ }
+ /* if transmit error, throw frame away by */
+ /* pretending it was accepted by driver */
+ if (actual < 0)
+ actual = tbuf->count;
+
+ if (actual == tbuf->count) {
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)frame %p completed\n",
+ __FILE__,__LINE__,tbuf);
+
+ /* free current transmit buffer */
+ n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, tbuf);
+
+ /* this tx buffer is done */
+ n_hdlc->tbuf = NULL;
+
+ /* wait up sleeping writers */
+ wake_up_interruptible(&tty->write_wait);
+
+ /* get next pending transmit buffer */
+ tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
+ } else {
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)frame %p pending\n",
+ __FILE__,__LINE__,tbuf);
+
+ /* buffer not accepted by driver */
+ /* set this buffer as pending buffer */
+ n_hdlc->tbuf = tbuf;
+ break;
+ }
+ }
+
+ if (!tbuf)
+ tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
+
+ /* Clear the re-entry flag */
+ spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
+ n_hdlc->tbusy = 0;
+ spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
+
+ if (n_hdlc->woke_up)
+ goto check_again;
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_send_frames() exit\n",__FILE__,__LINE__);
+
+} /* end of n_hdlc_send_frames() */
+
+/**
+ * n_hdlc_tty_wakeup - Callback for transmit wakeup
+ * @tty - pointer to associated tty instance data
+ *
+ * Called when low level device driver can accept more send data.
+ */
+static void n_hdlc_tty_wakeup(struct tty_struct *tty)
+{
+ struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_wakeup() called\n",__FILE__,__LINE__);
+
+ if (!n_hdlc)
+ return;
+
+ if (tty != n_hdlc->tty) {
+ tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
+ return;
+ }
+
+ n_hdlc_send_frames (n_hdlc, tty);
+
+} /* end of n_hdlc_tty_wakeup() */
+
+/**
+ * n_hdlc_tty_receive - Called by tty driver when receive data is available
+ * @tty - pointer to tty instance data
+ * @data - pointer to received data
+ * @flags - pointer to flags for data
+ * @count - count of received data in bytes
+ *
+ * Called by tty low level driver when receive data is available. Data is
+ * interpreted as one HDLC frame.
+ */
+static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data,
+ char *flags, int count)
+{
+ register struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+ register struct n_hdlc_buf *buf;
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_receive() called count=%d\n",
+ __FILE__,__LINE__, count);
+
+ /* This can happen if stuff comes in on the backup tty */
+ if (!n_hdlc || tty != n_hdlc->tty)
+ return;
+
+ /* verify line is using HDLC discipline */
+ if (n_hdlc->magic != HDLC_MAGIC) {
+ printk("%s(%d) line not using HDLC discipline\n",
+ __FILE__,__LINE__);
+ return;
+ }
+
+ if ( count>maxframe ) {
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d) rx count>maxframesize, data discarded\n",
+ __FILE__,__LINE__);
+ return;
+ }
+
+ /* get a free HDLC buffer */
+ buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list);
+ if (!buf) {
+ /* no buffers in free list, attempt to allocate another rx buffer */
+ /* unless the maximum count has been reached */
+ if (n_hdlc->rx_buf_list.count < MAX_RX_BUF_COUNT)
+ buf = kmalloc(N_HDLC_BUF_SIZE, GFP_ATOMIC);
+ }
+
+ if (!buf) {
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d) no more rx buffers, data discarded\n",
+ __FILE__,__LINE__);
+ return;
+ }
+
+ /* copy received data to HDLC buffer */
+ memcpy(buf->buf,data,count);
+ buf->count=count;
+
+ /* add HDLC buffer to list of received frames */
+ n_hdlc_buf_put(&n_hdlc->rx_buf_list, buf);
+
+ /* wake up any blocked reads and perform async signalling */
+ wake_up_interruptible (&tty->read_wait);
+ if (n_hdlc->tty->fasync != NULL)
+ kill_fasync (&n_hdlc->tty->fasync, SIGIO, POLL_IN);
+
+} /* end of n_hdlc_tty_receive() */
+
+/**
+ * n_hdlc_tty_read - Called to retrieve one frame of data (if available)
+ * @tty - pointer to tty instance data
+ * @file - pointer to open file object
+ * @buf - pointer to returned data buffer
+ * @nr - size of returned data buffer
+ *
+ * Returns the number of bytes returned or error code.
+ */
+static ssize_t n_hdlc_tty_read(struct tty_struct *tty, struct file *file,
+ __u8 __user *buf, size_t nr)
+{
+ struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
+ int ret;
+ struct n_hdlc_buf *rbuf;
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_read() called\n",__FILE__,__LINE__);
+
+ /* Validate the pointers */
+ if (!n_hdlc)
+ return -EIO;
+
+ /* verify user access to buffer */
+ if (!access_ok(VERIFY_WRITE, buf, nr)) {
+ printk(KERN_WARNING "%s(%d) n_hdlc_tty_read() can't verify user "
+ "buffer\n", __FILE__, __LINE__);
+ return -EFAULT;
+ }
+
+ tty_lock();
+
+ for (;;) {
+ if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+ tty_unlock();
+ return -EIO;
+ }
+
+ n_hdlc = tty2n_hdlc (tty);
+ if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC ||
+ tty != n_hdlc->tty) {
+ tty_unlock();
+ return 0;
+ }
+
+ rbuf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);
+ if (rbuf)
+ break;
+
+ /* no data */
+ if (file->f_flags & O_NONBLOCK) {
+ tty_unlock();
+ return -EAGAIN;
+ }
+
+ interruptible_sleep_on (&tty->read_wait);
+ if (signal_pending(current)) {
+ tty_unlock();
+ return -EINTR;
+ }
+ }
+
+ if (rbuf->count > nr)
+ /* frame too large for caller's buffer (discard frame) */
+ ret = -EOVERFLOW;
+ else {
+ /* Copy the data to the caller's buffer */
+ if (copy_to_user(buf, rbuf->buf, rbuf->count))
+ ret = -EFAULT;
+ else
+ ret = rbuf->count;
+ }
+
+ /* return HDLC buffer to free list unless the free list */
+ /* count has exceeded the default value, in which case the */
+ /* buffer is freed back to the OS to conserve memory */
+ if (n_hdlc->rx_free_buf_list.count > DEFAULT_RX_BUF_COUNT)
+ kfree(rbuf);
+ else
+ n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,rbuf);
+ tty_unlock();
+ return ret;
+
+} /* end of n_hdlc_tty_read() */
+
+/**
+ * n_hdlc_tty_write - write a single frame of data to device
+ * @tty - pointer to associated tty device instance data
+ * @file - pointer to file object data
+ * @data - pointer to transmit data (one frame)
+ * @count - size of transmit frame in bytes
+ *
+ * Returns the number of bytes written (or error code).
+ */
+static ssize_t n_hdlc_tty_write(struct tty_struct *tty, struct file *file,
+ const unsigned char *data, size_t count)
+{
+ struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+ int error = 0;
+ DECLARE_WAITQUEUE(wait, current);
+ struct n_hdlc_buf *tbuf;
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_write() called count=%Zd\n",
+ __FILE__,__LINE__,count);
+
+ /* Verify pointers */
+ if (!n_hdlc)
+ return -EIO;
+
+ if (n_hdlc->magic != HDLC_MAGIC)
+ return -EIO;
+
+ /* verify frame size */
+ if (count > maxframe ) {
+ if (debuglevel & DEBUG_LEVEL_INFO)
+ printk (KERN_WARNING
+ "n_hdlc_tty_write: truncating user packet "
+ "from %lu to %d\n", (unsigned long) count,
+ maxframe );
+ count = maxframe;
+ }
+
+ tty_lock();
+
+ add_wait_queue(&tty->write_wait, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ /* Allocate transmit buffer */
+ /* sleep until transmit buffer available */
+ while (!(tbuf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list))) {
+ if (file->f_flags & O_NONBLOCK) {
+ error = -EAGAIN;
+ break;
+ }
+ schedule();
+
+ n_hdlc = tty2n_hdlc (tty);
+ if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC ||
+ tty != n_hdlc->tty) {
+ printk("n_hdlc_tty_write: %p invalid after wait!\n", n_hdlc);
+ error = -EIO;
+ break;
+ }
+
+ if (signal_pending(current)) {
+ error = -EINTR;
+ break;
+ }
+ }
+
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&tty->write_wait, &wait);
+
+ if (!error) {
+ /* Retrieve the user's buffer */
+ memcpy(tbuf->buf, data, count);
+
+ /* Send the data */
+ tbuf->count = error = count;
+ n_hdlc_buf_put(&n_hdlc->tx_buf_list,tbuf);
+ n_hdlc_send_frames(n_hdlc,tty);
+ }
+ tty_unlock();
+ return error;
+
+} /* end of n_hdlc_tty_write() */
+
+/**
+ * n_hdlc_tty_ioctl - process IOCTL system call for the tty device.
+ * @tty - pointer to tty instance data
+ * @file - pointer to open file object for device
+ * @cmd - IOCTL command code
+ * @arg - argument for IOCTL call (cmd dependent)
+ *
+ * Returns command dependent result.
+ */
+static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+ int error = 0;
+ int count;
+ unsigned long flags;
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_ioctl() called %d\n",
+ __FILE__,__LINE__,cmd);
+
+ /* Verify the status of the device */
+ if (!n_hdlc || n_hdlc->magic != HDLC_MAGIC)
+ return -EBADF;
+
+ switch (cmd) {
+ case FIONREAD:
+ /* report count of read data available */
+ /* in next available frame (if any) */
+ spin_lock_irqsave(&n_hdlc->rx_buf_list.spinlock,flags);
+ if (n_hdlc->rx_buf_list.head)
+ count = n_hdlc->rx_buf_list.head->count;
+ else
+ count = 0;
+ spin_unlock_irqrestore(&n_hdlc->rx_buf_list.spinlock,flags);
+ error = put_user(count, (int __user *)arg);
+ break;
+
+ case TIOCOUTQ:
+ /* get the pending tx byte count in the driver */
+ count = tty_chars_in_buffer(tty);
+ /* add size of next output frame in queue */
+ spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock,flags);
+ if (n_hdlc->tx_buf_list.head)
+ count += n_hdlc->tx_buf_list.head->count;
+ spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock,flags);
+ error = put_user(count, (int __user *)arg);
+ break;
+
+ case TCFLSH:
+ switch (arg) {
+ case TCIOFLUSH:
+ case TCOFLUSH:
+ flush_tx_queue(tty);
+ }
+ /* fall through to default */
+
+ default:
+ error = n_tty_ioctl_helper(tty, file, cmd, arg);
+ break;
+ }
+ return error;
+
+} /* end of n_hdlc_tty_ioctl() */
+
+/**
+ * n_hdlc_tty_poll - TTY callback for poll system call
+ * @tty - pointer to tty instance data
+ * @filp - pointer to open file object for device
+ * @poll_table - wait queue for operations
+ *
+ * Determine which operations (read/write) will not block and return info
+ * to caller.
+ * Returns a bit mask containing info on which ops will not block.
+ */
+static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
+ poll_table *wait)
+{
+ struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
+ unsigned int mask = 0;
+
+ if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_tty_poll() called\n",__FILE__,__LINE__);
+
+ if (n_hdlc && n_hdlc->magic == HDLC_MAGIC && tty == n_hdlc->tty) {
+ /* queue current process into any wait queue that */
+ /* may awaken in the future (read and write) */
+
+ poll_wait(filp, &tty->read_wait, wait);
+ poll_wait(filp, &tty->write_wait, wait);
+
+ /* set bits for operations that won't block */
+ if (n_hdlc->rx_buf_list.head)
+ mask |= POLLIN | POLLRDNORM; /* readable */
+ if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+ mask |= POLLHUP;
+ if (tty_hung_up_p(filp))
+ mask |= POLLHUP;
+ if (!tty_is_writelocked(tty) &&
+ n_hdlc->tx_free_buf_list.head)
+ mask |= POLLOUT | POLLWRNORM; /* writable */
+ }
+ return mask;
+} /* end of n_hdlc_tty_poll() */
+
+/**
+ * n_hdlc_alloc - allocate an n_hdlc instance data structure
+ *
+ * Returns a pointer to newly created structure if success, otherwise %NULL
+ */
+static struct n_hdlc *n_hdlc_alloc(void)
+{
+ struct n_hdlc_buf *buf;
+ int i;
+ struct n_hdlc *n_hdlc = kmalloc(sizeof(*n_hdlc), GFP_KERNEL);
+
+ if (!n_hdlc)
+ return NULL;
+
+ memset(n_hdlc, 0, sizeof(*n_hdlc));
+
+ n_hdlc_buf_list_init(&n_hdlc->rx_free_buf_list);
+ n_hdlc_buf_list_init(&n_hdlc->tx_free_buf_list);
+ n_hdlc_buf_list_init(&n_hdlc->rx_buf_list);
+ n_hdlc_buf_list_init(&n_hdlc->tx_buf_list);
+
+ /* allocate free rx buffer list */
+ for(i=0;i<DEFAULT_RX_BUF_COUNT;i++) {
+ buf = kmalloc(N_HDLC_BUF_SIZE, GFP_KERNEL);
+ if (buf)
+ n_hdlc_buf_put(&n_hdlc->rx_free_buf_list,buf);
+ else if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_alloc(), kalloc() failed for rx buffer %d\n",__FILE__,__LINE__, i);
+ }
+
+ /* allocate free tx buffer list */
+ for(i=0;i<DEFAULT_TX_BUF_COUNT;i++) {
+ buf = kmalloc(N_HDLC_BUF_SIZE, GFP_KERNEL);
+ if (buf)
+ n_hdlc_buf_put(&n_hdlc->tx_free_buf_list,buf);
+ else if (debuglevel >= DEBUG_LEVEL_INFO)
+ printk("%s(%d)n_hdlc_alloc(), kalloc() failed for tx buffer %d\n",__FILE__,__LINE__, i);
+ }
+
+ /* Initialize the control block */
+ n_hdlc->magic = HDLC_MAGIC;
+ n_hdlc->flags = 0;
+
+ return n_hdlc;
+
+} /* end of n_hdlc_alloc() */
+
+/**
+ * n_hdlc_buf_list_init - initialize specified HDLC buffer list
+ * @list - pointer to buffer list
+ */
+static void n_hdlc_buf_list_init(struct n_hdlc_buf_list *list)
+{
+ memset(list, 0, sizeof(*list));
+ spin_lock_init(&list->spinlock);
+} /* end of n_hdlc_buf_list_init() */
+
+/**
+ * n_hdlc_buf_put - add specified HDLC buffer to tail of specified list
+ * @list - pointer to buffer list
+ * @buf - pointer to buffer
+ */
+static void n_hdlc_buf_put(struct n_hdlc_buf_list *list,
+ struct n_hdlc_buf *buf)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&list->spinlock,flags);
+
+ buf->link=NULL;
+ if (list->tail)
+ list->tail->link = buf;
+ else
+ list->head = buf;
+ list->tail = buf;
+ (list->count)++;
+
+ spin_unlock_irqrestore(&list->spinlock,flags);
+
+} /* end of n_hdlc_buf_put() */
+
+/**
+ * n_hdlc_buf_get - remove and return an HDLC buffer from list
+ * @list - pointer to HDLC buffer list
+ *
+ * Remove and return an HDLC buffer from the head of the specified HDLC buffer
+ * list.
+ * Returns a pointer to HDLC buffer if available, otherwise %NULL.
+ */
+static struct n_hdlc_buf* n_hdlc_buf_get(struct n_hdlc_buf_list *list)
+{
+ unsigned long flags;
+ struct n_hdlc_buf *buf;
+ spin_lock_irqsave(&list->spinlock,flags);
+
+ buf = list->head;
+ if (buf) {
+ list->head = buf->link;
+ (list->count)--;
+ }
+ if (!list->head)
+ list->tail = NULL;
+
+ spin_unlock_irqrestore(&list->spinlock,flags);
+ return buf;
+
+} /* end of n_hdlc_buf_get() */
+
+static char hdlc_banner[] __initdata =
+ KERN_INFO "HDLC line discipline maxframe=%u\n";
+static char hdlc_register_ok[] __initdata =
+ KERN_INFO "N_HDLC line discipline registered.\n";
+static char hdlc_register_fail[] __initdata =
+ KERN_ERR "error registering line discipline: %d\n";
+static char hdlc_init_fail[] __initdata =
+ KERN_INFO "N_HDLC: init failure %d\n";
+
+static int __init n_hdlc_init(void)
+{
+ int status;
+
+ /* range check maxframe arg */
+ if (maxframe < 4096)
+ maxframe = 4096;
+ else if (maxframe > 65535)
+ maxframe = 65535;
+
+ printk(hdlc_banner, maxframe);
+
+ status = tty_register_ldisc(N_HDLC, &n_hdlc_ldisc);
+ if (!status)
+ printk(hdlc_register_ok);
+ else
+ printk(hdlc_register_fail, status);
+
+ if (status)
+ printk(hdlc_init_fail, status);
+ return status;
+
+} /* end of init_module() */
+
+static char hdlc_unregister_ok[] __exitdata =
+ KERN_INFO "N_HDLC: line discipline unregistered\n";
+static char hdlc_unregister_fail[] __exitdata =
+ KERN_ERR "N_HDLC: can't unregister line discipline (err = %d)\n";
+
+static void __exit n_hdlc_exit(void)
+{
+ /* Release tty registration of line discipline */
+ int status = tty_unregister_ldisc(N_HDLC);
+
+ if (status)
+ printk(hdlc_unregister_fail, status);
+ else
+ printk(hdlc_unregister_ok);
+}
+
+module_init(n_hdlc_init);
+module_exit(n_hdlc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul Fulghum paulkf@microgate.com");
+module_param(debuglevel, int, 0);
+module_param(maxframe, int, 0);
+MODULE_ALIAS_LDISC(N_HDLC);
--- /dev/null
+/* r3964 linediscipline for linux
+ *
+ * -----------------------------------------------------------
+ * Copyright by
+ * Philips Automation Projects
+ * Kassel (Germany)
+ * -----------------------------------------------------------
+ * This software may be used and distributed according to the terms of
+ * the GNU General Public License, incorporated herein by reference.
+ *
+ * Author:
+ * L. Haag
+ *
+ * $Log: n_r3964.c,v $
+ * Revision 1.10 2001/03/18 13:02:24 dwmw2
+ * Fix timer usage, use spinlocks properly.
+ *
+ * Revision 1.9 2001/03/18 12:52:14 dwmw2
+ * Merge changes in 2.4.2
+ *
+ * Revision 1.8 2000/03/23 14:14:54 dwmw2
+ * Fix race in sleeping in r3964_read()
+ *
+ * Revision 1.7 1999/28/08 11:41:50 dwmw2
+ * Port to 2.3 kernel
+ *
+ * Revision 1.6 1998/09/30 00:40:40 dwmw2
+ * Fixed compilation on 2.0.x kernels
+ * Updated to newly registered tty-ldisc number 9
+ *
+ * Revision 1.5 1998/09/04 21:57:36 dwmw2
+ * Signal handling bug fixes, port to 2.1.x.
+ *
+ * Revision 1.4 1998/04/02 20:26:59 lhaag
+ * select, blocking, ...
+ *
+ * Revision 1.3 1998/02/12 18:58:43 root
+ * fixed some memory leaks
+ * calculation of checksum characters
+ *
+ * Revision 1.2 1998/02/07 13:03:34 root
+ * ioctl read_telegram
+ *
+ * Revision 1.1 1998/02/06 19:21:03 root
+ * Initial revision
+ *
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/interrupt.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/in.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/string.h> /* used in new tty drivers */
+#include <linux/signal.h> /* used in new tty drivers */
+#include <linux/ioctl.h>
+#include <linux/n_r3964.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+
+/*#define DEBUG_QUEUE*/
+
+/* Log successful handshake and protocol operations */
+/*#define DEBUG_PROTO_S*/
+
+/* Log handshake and protocol errors: */
+/*#define DEBUG_PROTO_E*/
+
+/* Log Linediscipline operations (open, close, read, write...): */
+/*#define DEBUG_LDISC*/
+
+/* Log module and memory operations (init, cleanup; kmalloc, kfree): */
+/*#define DEBUG_MODUL*/
+
+/* Macro helpers for debug output: */
+#define TRACE(format, args...) printk("r3964: " format "\n" , ## args)
+
+#ifdef DEBUG_MODUL
+#define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_M(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_PROTO_S
+#define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_PS(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_PROTO_E
+#define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_PE(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_LDISC
+#define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_L(fmt, arg...) do {} while (0)
+#endif
+#ifdef DEBUG_QUEUE
+#define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args)
+#else
+#define TRACE_Q(fmt, arg...) do {} while (0)
+#endif
+static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
+static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
+static void put_char(struct r3964_info *pInfo, unsigned char ch);
+static void trigger_transmit(struct r3964_info *pInfo);
+static void retry_transmit(struct r3964_info *pInfo);
+static void transmit_block(struct r3964_info *pInfo);
+static void receive_char(struct r3964_info *pInfo, const unsigned char c);
+static void receive_error(struct r3964_info *pInfo, const char flag);
+static void on_timeout(unsigned long priv);
+static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg);
+static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
+ unsigned char __user * buf);
+static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
+ int error_code, struct r3964_block_header *pBlock);
+static struct r3964_message *remove_msg(struct r3964_info *pInfo,
+ struct r3964_client_info *pClient);
+static void remove_client_block(struct r3964_info *pInfo,
+ struct r3964_client_info *pClient);
+
+static int r3964_open(struct tty_struct *tty);
+static void r3964_close(struct tty_struct *tty);
+static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
+ unsigned char __user * buf, size_t nr);
+static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
+ const unsigned char *buf, size_t nr);
+static int r3964_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg);
+static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old);
+static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
+ struct poll_table_struct *wait);
+static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+ char *fp, int count);
+
+static struct tty_ldisc_ops tty_ldisc_N_R3964 = {
+ .owner = THIS_MODULE,
+ .magic = TTY_LDISC_MAGIC,
+ .name = "R3964",
+ .open = r3964_open,
+ .close = r3964_close,
+ .read = r3964_read,
+ .write = r3964_write,
+ .ioctl = r3964_ioctl,
+ .set_termios = r3964_set_termios,
+ .poll = r3964_poll,
+ .receive_buf = r3964_receive_buf,
+};
+
+static void dump_block(const unsigned char *block, unsigned int length)
+{
+ unsigned int i, j;
+ char linebuf[16 * 3 + 1];
+
+ for (i = 0; i < length; i += 16) {
+ for (j = 0; (j < 16) && (j + i < length); j++) {
+ sprintf(linebuf + 3 * j, "%02x ", block[i + j]);
+ }
+ linebuf[3 * j] = '\0';
+ TRACE_PS("%s", linebuf);
+ }
+}
+
+/*************************************************************
+ * Driver initialisation
+ *************************************************************/
+
+/*************************************************************
+ * Module support routines
+ *************************************************************/
+
+static void __exit r3964_exit(void)
+{
+ int status;
+
+ TRACE_M("cleanup_module()");
+
+ status = tty_unregister_ldisc(N_R3964);
+
+ if (status != 0) {
+ printk(KERN_ERR "r3964: error unregistering linediscipline: "
+ "%d\n", status);
+ } else {
+ TRACE_L("linediscipline successfully unregistered");
+ }
+}
+
+static int __init r3964_init(void)
+{
+ int status;
+
+ printk("r3964: Philips r3964 Driver $Revision: 1.10 $\n");
+
+ /*
+ * Register the tty line discipline
+ */
+
+ status = tty_register_ldisc(N_R3964, &tty_ldisc_N_R3964);
+ if (status == 0) {
+ TRACE_L("line discipline %d registered", N_R3964);
+ TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags,
+ tty_ldisc_N_R3964.num);
+ TRACE_L("open=%p", tty_ldisc_N_R3964.open);
+ TRACE_L("tty_ldisc_N_R3964 = %p", &tty_ldisc_N_R3964);
+ } else {
+ printk(KERN_ERR "r3964: error registering line discipline: "
+ "%d\n", status);
+ }
+ return status;
+}
+
+module_init(r3964_init);
+module_exit(r3964_exit);
+
+/*************************************************************
+ * Protocol implementation routines
+ *************************************************************/
+
+static void add_tx_queue(struct r3964_info *pInfo,
+ struct r3964_block_header *pHeader)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&pInfo->lock, flags);
+
+ pHeader->next = NULL;
+
+ if (pInfo->tx_last == NULL) {
+ pInfo->tx_first = pInfo->tx_last = pHeader;
+ } else {
+ pInfo->tx_last->next = pHeader;
+ pInfo->tx_last = pHeader;
+ }
+
+ spin_unlock_irqrestore(&pInfo->lock, flags);
+
+ TRACE_Q("add_tx_queue %p, length %d, tx_first = %p",
+ pHeader, pHeader->length, pInfo->tx_first);
+}
+
+static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
+{
+ struct r3964_block_header *pHeader;
+ unsigned long flags;
+#ifdef DEBUG_QUEUE
+ struct r3964_block_header *pDump;
+#endif
+
+ pHeader = pInfo->tx_first;
+
+ if (pHeader == NULL)
+ return;
+
+#ifdef DEBUG_QUEUE
+ printk("r3964: remove_from_tx_queue: %p, length %u - ",
+ pHeader, pHeader->length);
+ for (pDump = pHeader; pDump; pDump = pDump->next)
+ printk("%p ", pDump);
+ printk("\n");
+#endif
+
+ if (pHeader->owner) {
+ if (error_code) {
+ add_msg(pHeader->owner, R3964_MSG_ACK, 0,
+ error_code, NULL);
+ } else {
+ add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
+ error_code, NULL);
+ }
+ wake_up_interruptible(&pInfo->read_wait);
+ }
+
+ spin_lock_irqsave(&pInfo->lock, flags);
+
+ pInfo->tx_first = pHeader->next;
+ if (pInfo->tx_first == NULL) {
+ pInfo->tx_last = NULL;
+ }
+
+ spin_unlock_irqrestore(&pInfo->lock, flags);
+
+ kfree(pHeader);
+ TRACE_M("remove_from_tx_queue - kfree %p", pHeader);
+
+ TRACE_Q("remove_from_tx_queue: tx_first = %p, tx_last = %p",
+ pInfo->tx_first, pInfo->tx_last);
+}
+
+static void add_rx_queue(struct r3964_info *pInfo,
+ struct r3964_block_header *pHeader)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&pInfo->lock, flags);
+
+ pHeader->next = NULL;
+
+ if (pInfo->rx_last == NULL) {
+ pInfo->rx_first = pInfo->rx_last = pHeader;
+ } else {
+ pInfo->rx_last->next = pHeader;
+ pInfo->rx_last = pHeader;
+ }
+ pInfo->blocks_in_rx_queue++;
+
+ spin_unlock_irqrestore(&pInfo->lock, flags);
+
+ TRACE_Q("add_rx_queue: %p, length = %d, rx_first = %p, count = %d",
+ pHeader, pHeader->length,
+ pInfo->rx_first, pInfo->blocks_in_rx_queue);
+}
+
+static void remove_from_rx_queue(struct r3964_info *pInfo,
+ struct r3964_block_header *pHeader)
+{
+ unsigned long flags;
+ struct r3964_block_header *pFind;
+
+ if (pHeader == NULL)
+ return;
+
+ TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
+ pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
+ TRACE_Q("remove_from_rx_queue: %p, length %u",
+ pHeader, pHeader->length);
+
+ spin_lock_irqsave(&pInfo->lock, flags);
+
+ if (pInfo->rx_first == pHeader) {
+ /* Remove the first block in the linked list: */
+ pInfo->rx_first = pHeader->next;
+
+ if (pInfo->rx_first == NULL) {
+ pInfo->rx_last = NULL;
+ }
+ pInfo->blocks_in_rx_queue--;
+ } else {
+ /* Find block to remove: */
+ for (pFind = pInfo->rx_first; pFind; pFind = pFind->next) {
+ if (pFind->next == pHeader) {
+ /* Got it. */
+ pFind->next = pHeader->next;
+ pInfo->blocks_in_rx_queue--;
+ if (pFind->next == NULL) {
+ /* Oh, removed the last one! */
+ pInfo->rx_last = pFind;
+ }
+ break;
+ }
+ }
+ }
+
+ spin_unlock_irqrestore(&pInfo->lock, flags);
+
+ kfree(pHeader);
+ TRACE_M("remove_from_rx_queue - kfree %p", pHeader);
+
+ TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
+ pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
+}
+
+static void put_char(struct r3964_info *pInfo, unsigned char ch)
+{
+ struct tty_struct *tty = pInfo->tty;
+ /* FIXME: put_char should not be called from an IRQ */
+ tty_put_char(tty, ch);
+ pInfo->bcc ^= ch;
+}
+
+static void flush(struct r3964_info *pInfo)
+{
+ struct tty_struct *tty = pInfo->tty;
+
+ if (tty == NULL || tty->ops->flush_chars == NULL)
+ return;
+ tty->ops->flush_chars(tty);
+}
+
+static void trigger_transmit(struct r3964_info *pInfo)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&pInfo->lock, flags);
+
+ if ((pInfo->state == R3964_IDLE) && (pInfo->tx_first != NULL)) {
+ pInfo->state = R3964_TX_REQUEST;
+ pInfo->nRetry = 0;
+ pInfo->flags &= ~R3964_ERROR;
+ mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
+
+ spin_unlock_irqrestore(&pInfo->lock, flags);
+
+ TRACE_PS("trigger_transmit - sent STX");
+
+ put_char(pInfo, STX);
+ flush(pInfo);
+
+ pInfo->bcc = 0;
+ } else {
+ spin_unlock_irqrestore(&pInfo->lock, flags);
+ }
+}
+
+static void retry_transmit(struct r3964_info *pInfo)
+{
+ if (pInfo->nRetry < R3964_MAX_RETRIES) {
+ TRACE_PE("transmission failed. Retry #%d", pInfo->nRetry);
+ pInfo->bcc = 0;
+ put_char(pInfo, STX);
+ flush(pInfo);
+ pInfo->state = R3964_TX_REQUEST;
+ pInfo->nRetry++;
+ mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
+ } else {
+ TRACE_PE("transmission failed after %d retries",
+ R3964_MAX_RETRIES);
+
+ remove_from_tx_queue(pInfo, R3964_TX_FAIL);
+
+ put_char(pInfo, NAK);
+ flush(pInfo);
+ pInfo->state = R3964_IDLE;
+
+ trigger_transmit(pInfo);
+ }
+}
+
+static void transmit_block(struct r3964_info *pInfo)
+{
+ struct tty_struct *tty = pInfo->tty;
+ struct r3964_block_header *pBlock = pInfo->tx_first;
+ int room = 0;
+
+ if (tty == NULL || pBlock == NULL) {
+ return;
+ }
+
+ room = tty_write_room(tty);
+
+ TRACE_PS("transmit_block %p, room %d, length %d",
+ pBlock, room, pBlock->length);
+
+ while (pInfo->tx_position < pBlock->length) {
+ if (room < 2)
+ break;
+
+ if (pBlock->data[pInfo->tx_position] == DLE) {
+ /* send additional DLE char: */
+ put_char(pInfo, DLE);
+ }
+ put_char(pInfo, pBlock->data[pInfo->tx_position++]);
+
+ room--;
+ }
+
+ if ((pInfo->tx_position == pBlock->length) && (room >= 3)) {
+ put_char(pInfo, DLE);
+ put_char(pInfo, ETX);
+ if (pInfo->flags & R3964_BCC) {
+ put_char(pInfo, pInfo->bcc);
+ }
+ pInfo->state = R3964_WAIT_FOR_TX_ACK;
+ mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
+ }
+ flush(pInfo);
+}
+
+static void on_receive_block(struct r3964_info *pInfo)
+{
+ unsigned int length;
+ struct r3964_client_info *pClient;
+ struct r3964_block_header *pBlock;
+
+ length = pInfo->rx_position;
+
+ /* compare byte checksum characters: */
+ if (pInfo->flags & R3964_BCC) {
+ if (pInfo->bcc != pInfo->last_rx) {
+ TRACE_PE("checksum error - got %x but expected %x",
+ pInfo->last_rx, pInfo->bcc);
+ pInfo->flags |= R3964_CHECKSUM;
+ }
+ }
+
+ /* check for errors (parity, overrun,...): */
+ if (pInfo->flags & R3964_ERROR) {
+ TRACE_PE("on_receive_block - transmission failed error %x",
+ pInfo->flags & R3964_ERROR);
+
+ put_char(pInfo, NAK);
+ flush(pInfo);
+ if (pInfo->nRetry < R3964_MAX_RETRIES) {
+ pInfo->state = R3964_WAIT_FOR_RX_REPEAT;
+ pInfo->nRetry++;
+ mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
+ } else {
+ TRACE_PE("on_receive_block - failed after max retries");
+ pInfo->state = R3964_IDLE;
+ }
+ return;
+ }
+
+ /* received block; submit DLE: */
+ put_char(pInfo, DLE);
+ flush(pInfo);
+ del_timer_sync(&pInfo->tmr);
+ TRACE_PS(" rx success: got %d chars", length);
+
+ /* prepare struct r3964_block_header: */
+ pBlock = kmalloc(length + sizeof(struct r3964_block_header),
+ GFP_KERNEL);
+ TRACE_M("on_receive_block - kmalloc %p", pBlock);
+
+ if (pBlock == NULL)
+ return;
+
+ pBlock->length = length;
+ pBlock->data = ((unsigned char *)pBlock) +
+ sizeof(struct r3964_block_header);
+ pBlock->locks = 0;
+ pBlock->next = NULL;
+ pBlock->owner = NULL;
+
+ memcpy(pBlock->data, pInfo->rx_buf, length);
+
+ /* queue block into rx_queue: */
+ add_rx_queue(pInfo, pBlock);
+
+ /* notify attached client processes: */
+ for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
+ if (pClient->sig_flags & R3964_SIG_DATA) {
+ add_msg(pClient, R3964_MSG_DATA, length, R3964_OK,
+ pBlock);
+ }
+ }
+ wake_up_interruptible(&pInfo->read_wait);
+
+ pInfo->state = R3964_IDLE;
+
+ trigger_transmit(pInfo);
+}
+
+static void receive_char(struct r3964_info *pInfo, const unsigned char c)
+{
+ switch (pInfo->state) {
+ case R3964_TX_REQUEST:
+ if (c == DLE) {
+ TRACE_PS("TX_REQUEST - got DLE");
+
+ pInfo->state = R3964_TRANSMITTING;
+ pInfo->tx_position = 0;
+
+ transmit_block(pInfo);
+ } else if (c == STX) {
+ if (pInfo->nRetry == 0) {
+ TRACE_PE("TX_REQUEST - init conflict");
+ if (pInfo->priority == R3964_SLAVE) {
+ goto start_receiving;
+ }
+ } else {
+ TRACE_PE("TX_REQUEST - secondary init "
+ "conflict!? Switching to SLAVE mode "
+ "for next rx.");
+ goto start_receiving;
+ }
+ } else {
+ TRACE_PE("TX_REQUEST - char != DLE: %x", c);
+ retry_transmit(pInfo);
+ }
+ break;
+ case R3964_TRANSMITTING:
+ if (c == NAK) {
+ TRACE_PE("TRANSMITTING - got NAK");
+ retry_transmit(pInfo);
+ } else {
+ TRACE_PE("TRANSMITTING - got invalid char");
+
+ pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
+ mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
+ }
+ break;
+ case R3964_WAIT_FOR_TX_ACK:
+ if (c == DLE) {
+ TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
+ remove_from_tx_queue(pInfo, R3964_OK);
+
+ pInfo->state = R3964_IDLE;
+ trigger_transmit(pInfo);
+ } else {
+ retry_transmit(pInfo);
+ }
+ break;
+ case R3964_WAIT_FOR_RX_REPEAT:
+ /* FALLTHROUGH */
+ case R3964_IDLE:
+ if (c == STX) {
+ /* Prevent rx_queue from overflow: */
+ if (pInfo->blocks_in_rx_queue >=
+ R3964_MAX_BLOCKS_IN_RX_QUEUE) {
+ TRACE_PE("IDLE - got STX but no space in "
+ "rx_queue!");
+ pInfo->state = R3964_WAIT_FOR_RX_BUF;
+ mod_timer(&pInfo->tmr,
+ jiffies + R3964_TO_NO_BUF);
+ break;
+ }
+start_receiving:
+ /* Ok, start receiving: */
+ TRACE_PS("IDLE - got STX");
+ pInfo->rx_position = 0;
+ pInfo->last_rx = 0;
+ pInfo->flags &= ~R3964_ERROR;
+ pInfo->state = R3964_RECEIVING;
+ mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
+ pInfo->nRetry = 0;
+ put_char(pInfo, DLE);
+ flush(pInfo);
+ pInfo->bcc = 0;
+ }
+ break;
+ case R3964_RECEIVING:
+ if (pInfo->rx_position < RX_BUF_SIZE) {
+ pInfo->bcc ^= c;
+
+ if (c == DLE) {
+ if (pInfo->last_rx == DLE) {
+ pInfo->last_rx = 0;
+ goto char_to_buf;
+ }
+ pInfo->last_rx = DLE;
+ break;
+ } else if ((c == ETX) && (pInfo->last_rx == DLE)) {
+ if (pInfo->flags & R3964_BCC) {
+ pInfo->state = R3964_WAIT_FOR_BCC;
+ mod_timer(&pInfo->tmr,
+ jiffies + R3964_TO_ZVZ);
+ } else {
+ on_receive_block(pInfo);
+ }
+ } else {
+ pInfo->last_rx = c;
+char_to_buf:
+ pInfo->rx_buf[pInfo->rx_position++] = c;
+ mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
+ }
+ }
+ /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
+ break;
+ case R3964_WAIT_FOR_BCC:
+ pInfo->last_rx = c;
+ on_receive_block(pInfo);
+ break;
+ }
+}
+
+static void receive_error(struct r3964_info *pInfo, const char flag)
+{
+ switch (flag) {
+ case TTY_NORMAL:
+ break;
+ case TTY_BREAK:
+ TRACE_PE("received break");
+ pInfo->flags |= R3964_BREAK;
+ break;
+ case TTY_PARITY:
+ TRACE_PE("parity error");
+ pInfo->flags |= R3964_PARITY;
+ break;
+ case TTY_FRAME:
+ TRACE_PE("frame error");
+ pInfo->flags |= R3964_FRAME;
+ break;
+ case TTY_OVERRUN:
+ TRACE_PE("frame overrun");
+ pInfo->flags |= R3964_OVERRUN;
+ break;
+ default:
+ TRACE_PE("receive_error - unknown flag %d", flag);
+ pInfo->flags |= R3964_UNKNOWN;
+ break;
+ }
+}
+
+static void on_timeout(unsigned long priv)
+{
+ struct r3964_info *pInfo = (void *)priv;
+
+ switch (pInfo->state) {
+ case R3964_TX_REQUEST:
+ TRACE_PE("TX_REQUEST - timeout");
+ retry_transmit(pInfo);
+ break;
+ case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
+ put_char(pInfo, NAK);
+ flush(pInfo);
+ retry_transmit(pInfo);
+ break;
+ case R3964_WAIT_FOR_TX_ACK:
+ TRACE_PE("WAIT_FOR_TX_ACK - timeout");
+ retry_transmit(pInfo);
+ break;
+ case R3964_WAIT_FOR_RX_BUF:
+ TRACE_PE("WAIT_FOR_RX_BUF - timeout");
+ put_char(pInfo, NAK);
+ flush(pInfo);
+ pInfo->state = R3964_IDLE;
+ break;
+ case R3964_RECEIVING:
+ TRACE_PE("RECEIVING - timeout after %d chars",
+ pInfo->rx_position);
+ put_char(pInfo, NAK);
+ flush(pInfo);
+ pInfo->state = R3964_IDLE;
+ break;
+ case R3964_WAIT_FOR_RX_REPEAT:
+ TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
+ pInfo->state = R3964_IDLE;
+ break;
+ case R3964_WAIT_FOR_BCC:
+ TRACE_PE("WAIT_FOR_BCC - timeout");
+ put_char(pInfo, NAK);
+ flush(pInfo);
+ pInfo->state = R3964_IDLE;
+ break;
+ }
+}
+
+static struct r3964_client_info *findClient(struct r3964_info *pInfo,
+ struct pid *pid)
+{
+ struct r3964_client_info *pClient;
+
+ for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
+ if (pClient->pid == pid) {
+ return pClient;
+ }
+ }
+ return NULL;
+}
+
+static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg)
+{
+ struct r3964_client_info *pClient;
+ struct r3964_client_info **ppClient;
+ struct r3964_message *pMsg;
+
+ if ((arg & R3964_SIG_ALL) == 0) {
+ /* Remove client from client list */
+ for (ppClient = &pInfo->firstClient; *ppClient;
+ ppClient = &(*ppClient)->next) {
+ pClient = *ppClient;
+
+ if (pClient->pid == pid) {
+ TRACE_PS("removing client %d from client list",
+ pid_nr(pid));
+ *ppClient = pClient->next;
+ while (pClient->msg_count) {
+ pMsg = remove_msg(pInfo, pClient);
+ if (pMsg) {
+ kfree(pMsg);
+ TRACE_M("enable_signals - msg "
+ "kfree %p", pMsg);
+ }
+ }
+ put_pid(pClient->pid);
+ kfree(pClient);
+ TRACE_M("enable_signals - kfree %p", pClient);
+ return 0;
+ }
+ }
+ return -EINVAL;
+ } else {
+ pClient = findClient(pInfo, pid);
+ if (pClient) {
+ /* update signal options */
+ pClient->sig_flags = arg;
+ } else {
+ /* add client to client list */
+ pClient = kmalloc(sizeof(struct r3964_client_info),
+ GFP_KERNEL);
+ TRACE_M("enable_signals - kmalloc %p", pClient);
+ if (pClient == NULL)
+ return -ENOMEM;
+
+ TRACE_PS("add client %d to client list", pid_nr(pid));
+ spin_lock_init(&pClient->lock);
+ pClient->sig_flags = arg;
+ pClient->pid = get_pid(pid);
+ pClient->next = pInfo->firstClient;
+ pClient->first_msg = NULL;
+ pClient->last_msg = NULL;
+ pClient->next_block_to_read = NULL;
+ pClient->msg_count = 0;
+ pInfo->firstClient = pClient;
+ }
+ }
+
+ return 0;
+}
+
+static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
+ unsigned char __user * buf)
+{
+ struct r3964_client_info *pClient;
+ struct r3964_block_header *block;
+
+ if (!buf) {
+ return -EINVAL;
+ }
+
+ pClient = findClient(pInfo, pid);
+ if (pClient == NULL) {
+ return -EINVAL;
+ }
+
+ block = pClient->next_block_to_read;
+ if (!block) {
+ return 0;
+ } else {
+ if (copy_to_user(buf, block->data, block->length))
+ return -EFAULT;
+
+ remove_client_block(pInfo, pClient);
+ return block->length;
+ }
+
+ return -EINVAL;
+}
+
+static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
+ int error_code, struct r3964_block_header *pBlock)
+{
+ struct r3964_message *pMsg;
+ unsigned long flags;
+
+ if (pClient->msg_count < R3964_MAX_MSG_COUNT - 1) {
+queue_the_message:
+
+ pMsg = kmalloc(sizeof(struct r3964_message),
+ error_code ? GFP_ATOMIC : GFP_KERNEL);
+ TRACE_M("add_msg - kmalloc %p", pMsg);
+ if (pMsg == NULL) {
+ return;
+ }
+
+ spin_lock_irqsave(&pClient->lock, flags);
+
+ pMsg->msg_id = msg_id;
+ pMsg->arg = arg;
+ pMsg->error_code = error_code;
+ pMsg->block = pBlock;
+ pMsg->next = NULL;
+
+ if (pClient->last_msg == NULL) {
+ pClient->first_msg = pClient->last_msg = pMsg;
+ } else {
+ pClient->last_msg->next = pMsg;
+ pClient->last_msg = pMsg;
+ }
+
+ pClient->msg_count++;
+
+ if (pBlock != NULL) {
+ pBlock->locks++;
+ }
+ spin_unlock_irqrestore(&pClient->lock, flags);
+ } else {
+ if ((pClient->last_msg->msg_id == R3964_MSG_ACK)
+ && (pClient->last_msg->error_code == R3964_OVERFLOW)) {
+ pClient->last_msg->arg++;
+ TRACE_PE("add_msg - inc prev OVERFLOW-msg");
+ } else {
+ msg_id = R3964_MSG_ACK;
+ arg = 0;
+ error_code = R3964_OVERFLOW;
+ pBlock = NULL;
+ TRACE_PE("add_msg - queue OVERFLOW-msg");
+ goto queue_the_message;
+ }
+ }
+ /* Send SIGIO signal to client process: */
+ if (pClient->sig_flags & R3964_USE_SIGIO) {
+ kill_pid(pClient->pid, SIGIO, 1);
+ }
+}
+
+static struct r3964_message *remove_msg(struct r3964_info *pInfo,
+ struct r3964_client_info *pClient)
+{
+ struct r3964_message *pMsg = NULL;
+ unsigned long flags;
+
+ if (pClient->first_msg) {
+ spin_lock_irqsave(&pClient->lock, flags);
+
+ pMsg = pClient->first_msg;
+ pClient->first_msg = pMsg->next;
+ if (pClient->first_msg == NULL) {
+ pClient->last_msg = NULL;
+ }
+
+ pClient->msg_count--;
+ if (pMsg->block) {
+ remove_client_block(pInfo, pClient);
+ pClient->next_block_to_read = pMsg->block;
+ }
+ spin_unlock_irqrestore(&pClient->lock, flags);
+ }
+ return pMsg;
+}
+
+static void remove_client_block(struct r3964_info *pInfo,
+ struct r3964_client_info *pClient)
+{
+ struct r3964_block_header *block;
+
+ TRACE_PS("remove_client_block PID %d", pid_nr(pClient->pid));
+
+ block = pClient->next_block_to_read;
+ if (block) {
+ block->locks--;
+ if (block->locks == 0) {
+ remove_from_rx_queue(pInfo, block);
+ }
+ }
+ pClient->next_block_to_read = NULL;
+}
+
+/*************************************************************
+ * Line discipline routines
+ *************************************************************/
+
+static int r3964_open(struct tty_struct *tty)
+{
+ struct r3964_info *pInfo;
+
+ TRACE_L("open");
+ TRACE_L("tty=%p, PID=%d, disc_data=%p",
+ tty, current->pid, tty->disc_data);
+
+ pInfo = kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
+ TRACE_M("r3964_open - info kmalloc %p", pInfo);
+
+ if (!pInfo) {
+ printk(KERN_ERR "r3964: failed to alloc info structure\n");
+ return -ENOMEM;
+ }
+
+ pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
+ TRACE_M("r3964_open - rx_buf kmalloc %p", pInfo->rx_buf);
+
+ if (!pInfo->rx_buf) {
+ printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
+ kfree(pInfo);
+ TRACE_M("r3964_open - info kfree %p", pInfo);
+ return -ENOMEM;
+ }
+
+ pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
+ TRACE_M("r3964_open - tx_buf kmalloc %p", pInfo->tx_buf);
+
+ if (!pInfo->tx_buf) {
+ printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
+ kfree(pInfo->rx_buf);
+ TRACE_M("r3964_open - rx_buf kfree %p", pInfo->rx_buf);
+ kfree(pInfo);
+ TRACE_M("r3964_open - info kfree %p", pInfo);
+ return -ENOMEM;
+ }
+
+ spin_lock_init(&pInfo->lock);
+ pInfo->tty = tty;
+ init_waitqueue_head(&pInfo->read_wait);
+ pInfo->priority = R3964_MASTER;
+ pInfo->rx_first = pInfo->rx_last = NULL;
+ pInfo->tx_first = pInfo->tx_last = NULL;
+ pInfo->rx_position = 0;
+ pInfo->tx_position = 0;
+ pInfo->last_rx = 0;
+ pInfo->blocks_in_rx_queue = 0;
+ pInfo->firstClient = NULL;
+ pInfo->state = R3964_IDLE;
+ pInfo->flags = R3964_DEBUG;
+ pInfo->nRetry = 0;
+
+ tty->disc_data = pInfo;
+ tty->receive_room = 65536;
+
+ setup_timer(&pInfo->tmr, on_timeout, (unsigned long)pInfo);
+
+ return 0;
+}
+
+static void r3964_close(struct tty_struct *tty)
+{
+ struct r3964_info *pInfo = tty->disc_data;
+ struct r3964_client_info *pClient, *pNext;
+ struct r3964_message *pMsg;
+ struct r3964_block_header *pHeader, *pNextHeader;
+ unsigned long flags;
+
+ TRACE_L("close");
+
+ /*
+ * Make sure that our task queue isn't activated. If it
+ * is, take it out of the linked list.
+ */
+ del_timer_sync(&pInfo->tmr);
+
+ /* Remove client-structs and message queues: */
+ pClient = pInfo->firstClient;
+ while (pClient) {
+ pNext = pClient->next;
+ while (pClient->msg_count) {
+ pMsg = remove_msg(pInfo, pClient);
+ if (pMsg) {
+ kfree(pMsg);
+ TRACE_M("r3964_close - msg kfree %p", pMsg);
+ }
+ }
+ put_pid(pClient->pid);
+ kfree(pClient);
+ TRACE_M("r3964_close - client kfree %p", pClient);
+ pClient = pNext;
+ }
+ /* Remove jobs from tx_queue: */
+ spin_lock_irqsave(&pInfo->lock, flags);
+ pHeader = pInfo->tx_first;
+ pInfo->tx_first = pInfo->tx_last = NULL;
+ spin_unlock_irqrestore(&pInfo->lock, flags);
+
+ while (pHeader) {
+ pNextHeader = pHeader->next;
+ kfree(pHeader);
+ pHeader = pNextHeader;
+ }
+
+ /* Free buffers: */
+ wake_up_interruptible(&pInfo->read_wait);
+ kfree(pInfo->rx_buf);
+ TRACE_M("r3964_close - rx_buf kfree %p", pInfo->rx_buf);
+ kfree(pInfo->tx_buf);
+ TRACE_M("r3964_close - tx_buf kfree %p", pInfo->tx_buf);
+ kfree(pInfo);
+ TRACE_M("r3964_close - info kfree %p", pInfo);
+}
+
+static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
+ unsigned char __user * buf, size_t nr)
+{
+ struct r3964_info *pInfo = tty->disc_data;
+ struct r3964_client_info *pClient;
+ struct r3964_message *pMsg;
+ struct r3964_client_message theMsg;
+ int ret;
+
+ TRACE_L("read()");
+
+ tty_lock();
+
+ pClient = findClient(pInfo, task_pid(current));
+ if (pClient) {
+ pMsg = remove_msg(pInfo, pClient);
+ if (pMsg == NULL) {
+ /* no messages available. */
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ goto unlock;
+ }
+ /* block until there is a message: */
+ wait_event_interruptible_tty(pInfo->read_wait,
+ (pMsg = remove_msg(pInfo, pClient)));
+ }
+
+ /* If we still haven't got a message, we must have been signalled */
+
+ if (!pMsg) {
+ ret = -EINTR;
+ goto unlock;
+ }
+
+ /* deliver msg to client process: */
+ theMsg.msg_id = pMsg->msg_id;
+ theMsg.arg = pMsg->arg;
+ theMsg.error_code = pMsg->error_code;
+ ret = sizeof(struct r3964_client_message);
+
+ kfree(pMsg);
+ TRACE_M("r3964_read - msg kfree %p", pMsg);
+
+ if (copy_to_user(buf, &theMsg, ret)) {
+ ret = -EFAULT;
+ goto unlock;
+ }
+
+ TRACE_PS("read - return %d", ret);
+ goto unlock;
+ }
+ ret = -EPERM;
+unlock:
+ tty_unlock();
+ return ret;
+}
+
+static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
+ const unsigned char *data, size_t count)
+{
+ struct r3964_info *pInfo = tty->disc_data;
+ struct r3964_block_header *pHeader;
+ struct r3964_client_info *pClient;
+ unsigned char *new_data;
+
+ TRACE_L("write request, %d characters", count);
+/*
+ * Verify the pointers
+ */
+
+ if (!pInfo)
+ return -EIO;
+
+/*
+ * Ensure that the caller does not wish to send too much.
+ */
+ if (count > R3964_MTU) {
+ if (pInfo->flags & R3964_DEBUG) {
+ TRACE_L(KERN_WARNING "r3964_write: truncating user "
+ "packet from %u to mtu %d", count, R3964_MTU);
+ }
+ count = R3964_MTU;
+ }
+/*
+ * Allocate a buffer for the data and copy it from the buffer with header prepended
+ */
+ new_data = kmalloc(count + sizeof(struct r3964_block_header),
+ GFP_KERNEL);
+ TRACE_M("r3964_write - kmalloc %p", new_data);
+ if (new_data == NULL) {
+ if (pInfo->flags & R3964_DEBUG) {
+ printk(KERN_ERR "r3964_write: no memory\n");
+ }
+ return -ENOSPC;
+ }
+
+ pHeader = (struct r3964_block_header *)new_data;
+ pHeader->data = new_data + sizeof(struct r3964_block_header);
+ pHeader->length = count;
+ pHeader->locks = 0;
+ pHeader->owner = NULL;
+
+ tty_lock();
+
+ pClient = findClient(pInfo, task_pid(current));
+ if (pClient) {
+ pHeader->owner = pClient;
+ }
+
+ memcpy(pHeader->data, data, count); /* We already verified this */
+
+ if (pInfo->flags & R3964_DEBUG) {
+ dump_block(pHeader->data, count);
+ }
+
+/*
+ * Add buffer to transmit-queue:
+ */
+ add_tx_queue(pInfo, pHeader);
+ trigger_transmit(pInfo);
+
+ tty_unlock();
+
+ return 0;
+}
+
+static int r3964_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct r3964_info *pInfo = tty->disc_data;
+ if (pInfo == NULL)
+ return -EINVAL;
+ switch (cmd) {
+ case R3964_ENABLE_SIGNALS:
+ return enable_signals(pInfo, task_pid(current), arg);
+ case R3964_SETPRIORITY:
+ if (arg < R3964_MASTER || arg > R3964_SLAVE)
+ return -EINVAL;
+ pInfo->priority = arg & 0xff;
+ return 0;
+ case R3964_USE_BCC:
+ if (arg)
+ pInfo->flags |= R3964_BCC;
+ else
+ pInfo->flags &= ~R3964_BCC;
+ return 0;
+ case R3964_READ_TELEGRAM:
+ return read_telegram(pInfo, task_pid(current),
+ (unsigned char __user *)arg);
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old)
+{
+ TRACE_L("set_termios");
+}
+
+/* Called without the kernel lock held - fine */
+static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
+ struct poll_table_struct *wait)
+{
+ struct r3964_info *pInfo = tty->disc_data;
+ struct r3964_client_info *pClient;
+ struct r3964_message *pMsg = NULL;
+ unsigned long flags;
+ int result = POLLOUT;
+
+ TRACE_L("POLL");
+
+ pClient = findClient(pInfo, task_pid(current));
+ if (pClient) {
+ poll_wait(file, &pInfo->read_wait, wait);
+ spin_lock_irqsave(&pInfo->lock, flags);
+ pMsg = pClient->first_msg;
+ spin_unlock_irqrestore(&pInfo->lock, flags);
+ if (pMsg)
+ result |= POLLIN | POLLRDNORM;
+ } else {
+ result = -EINVAL;
+ }
+ return result;
+}
+
+static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+ char *fp, int count)
+{
+ struct r3964_info *pInfo = tty->disc_data;
+ const unsigned char *p;
+ char *f, flags = 0;
+ int i;
+
+ for (i = count, p = cp, f = fp; i; i--, p++) {
+ if (f)
+ flags = *f++;
+ if (flags == TTY_NORMAL) {
+ receive_char(pInfo, *p);
+ } else {
+ receive_error(pInfo, flags);
+ }
+
+ }
+}
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_LDISC(N_R3964);
--- /dev/null
+/*
+ * n_tty.c --- implements the N_TTY line discipline.
+ *
+ * This code used to be in tty_io.c, but things are getting hairy
+ * enough that it made sense to split things off. (The N_TTY
+ * processing has changed so much that it's hardly recognizable,
+ * anyway...)
+ *
+ * Note that the open routine for N_TTY is guaranteed never to return
+ * an error. This is because Linux will fall back to setting a line
+ * to N_TTY if it can not switch to any other line discipline.
+ *
+ * Written by Theodore Ts'o, Copyright 1994.
+ *
+ * This file also contains code originally written by Linus Torvalds,
+ * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994.
+ *
+ * This file may be redistributed under the terms of the GNU General Public
+ * License.
+ *
+ * Reduced memory usage for older ARM systems - Russell King.
+ *
+ * 2000/01/20 Fixed SMP locking on put_tty_queue using bits of
+ * the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu>
+ * who actually finally proved there really was a race.
+ *
+ * 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to
+ * waiting writing processes-Sapan Bhatia <sapan@corewars.org>.
+ * Also fixed a bug in BLOCKING mode where n_tty_write returns
+ * EAGAIN
+ */
+
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/bitops.h>
+#include <linux/audit.h>
+#include <linux/file.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+
+#include <asm/system.h>
+
+/* number of characters left in xmit buffer before select has we have room */
+#define WAKEUP_CHARS 256
+
+/*
+ * This defines the low- and high-watermarks for throttling and
+ * unthrottling the TTY driver. These watermarks are used for
+ * controlling the space in the read buffer.
+ */
+#define TTY_THRESHOLD_THROTTLE 128 /* now based on remaining room */
+#define TTY_THRESHOLD_UNTHROTTLE 128
+
+/*
+ * Special byte codes used in the echo buffer to represent operations
+ * or special handling of characters. Bytes in the echo buffer that
+ * are not part of such special blocks are treated as normal character
+ * codes.
+ */
+#define ECHO_OP_START 0xff
+#define ECHO_OP_MOVE_BACK_COL 0x80
+#define ECHO_OP_SET_CANON_COL 0x81
+#define ECHO_OP_ERASE_TAB 0x82
+
+static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
+ unsigned char __user *ptr)
+{
+ tty_audit_add_data(tty, &x, 1);
+ return put_user(x, ptr);
+}
+
+/**
+ * n_tty_set__room - receive space
+ * @tty: terminal
+ *
+ * Called by the driver to find out how much data it is
+ * permitted to feed to the line discipline without any being lost
+ * and thus to manage flow control. Not serialized. Answers for the
+ * "instant".
+ */
+
+static void n_tty_set_room(struct tty_struct *tty)
+{
+ /* tty->read_cnt is not read locked ? */
+ int left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
+
+ /*
+ * If we are doing input canonicalization, and there are no
+ * pending newlines, let characters through without limit, so
+ * that erase characters will be handled. Other excess
+ * characters will be beeped.
+ */
+ if (left <= 0)
+ left = tty->icanon && !tty->canon_data;
+ tty->receive_room = left;
+}
+
+static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty)
+{
+ if (tty->read_cnt < N_TTY_BUF_SIZE) {
+ tty->read_buf[tty->read_head] = c;
+ tty->read_head = (tty->read_head + 1) & (N_TTY_BUF_SIZE-1);
+ tty->read_cnt++;
+ }
+}
+
+/**
+ * put_tty_queue - add character to tty
+ * @c: character
+ * @tty: tty device
+ *
+ * Add a character to the tty read_buf queue. This is done under the
+ * read_lock to serialize character addition and also to protect us
+ * against parallel reads or flushes
+ */
+
+static void put_tty_queue(unsigned char c, struct tty_struct *tty)
+{
+ unsigned long flags;
+ /*
+ * The problem of stomping on the buffers ends here.
+ * Why didn't anyone see this one coming? --AJK
+ */
+ spin_lock_irqsave(&tty->read_lock, flags);
+ put_tty_queue_nolock(c, tty);
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+}
+
+/**
+ * check_unthrottle - allow new receive data
+ * @tty; tty device
+ *
+ * Check whether to call the driver unthrottle functions
+ *
+ * Can sleep, may be called under the atomic_read_lock mutex but
+ * this is not guaranteed.
+ */
+static void check_unthrottle(struct tty_struct *tty)
+{
+ if (tty->count)
+ tty_unthrottle(tty);
+}
+
+/**
+ * reset_buffer_flags - reset buffer state
+ * @tty: terminal to reset
+ *
+ * Reset the read buffer counters, clear the flags,
+ * and make sure the driver is unthrottled. Called
+ * from n_tty_open() and n_tty_flush_buffer().
+ *
+ * Locking: tty_read_lock for read fields.
+ */
+
+static void reset_buffer_flags(struct tty_struct *tty)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&tty->read_lock, flags);
+ tty->read_head = tty->read_tail = tty->read_cnt = 0;
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+
+ mutex_lock(&tty->echo_lock);
+ tty->echo_pos = tty->echo_cnt = tty->echo_overrun = 0;
+ mutex_unlock(&tty->echo_lock);
+
+ tty->canon_head = tty->canon_data = tty->erasing = 0;
+ memset(&tty->read_flags, 0, sizeof tty->read_flags);
+ n_tty_set_room(tty);
+ check_unthrottle(tty);
+}
+
+/**
+ * n_tty_flush_buffer - clean input queue
+ * @tty: terminal device
+ *
+ * Flush the input buffer. Called when the line discipline is
+ * being closed, when the tty layer wants the buffer flushed (eg
+ * at hangup) or when the N_TTY line discipline internally has to
+ * clean the pending queue (for example some signals).
+ *
+ * Locking: ctrl_lock, read_lock.
+ */
+
+static void n_tty_flush_buffer(struct tty_struct *tty)
+{
+ unsigned long flags;
+ /* clear everything and unthrottle the driver */
+ reset_buffer_flags(tty);
+
+ if (!tty->link)
+ return;
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ if (tty->link->packet) {
+ tty->ctrl_status |= TIOCPKT_FLUSHREAD;
+ wake_up_interruptible(&tty->link->read_wait);
+ }
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+}
+
+/**
+ * n_tty_chars_in_buffer - report available bytes
+ * @tty: tty device
+ *
+ * Report the number of characters buffered to be delivered to user
+ * at this instant in time.
+ *
+ * Locking: read_lock
+ */
+
+static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
+{
+ unsigned long flags;
+ ssize_t n = 0;
+
+ spin_lock_irqsave(&tty->read_lock, flags);
+ if (!tty->icanon) {
+ n = tty->read_cnt;
+ } else if (tty->canon_data) {
+ n = (tty->canon_head > tty->read_tail) ?
+ tty->canon_head - tty->read_tail :
+ tty->canon_head + (N_TTY_BUF_SIZE - tty->read_tail);
+ }
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+ return n;
+}
+
+/**
+ * is_utf8_continuation - utf8 multibyte check
+ * @c: byte to check
+ *
+ * Returns true if the utf8 character 'c' is a multibyte continuation
+ * character. We use this to correctly compute the on screen size
+ * of the character when printing
+ */
+
+static inline int is_utf8_continuation(unsigned char c)
+{
+ return (c & 0xc0) == 0x80;
+}
+
+/**
+ * is_continuation - multibyte check
+ * @c: byte to check
+ *
+ * Returns true if the utf8 character 'c' is a multibyte continuation
+ * character and the terminal is in unicode mode.
+ */
+
+static inline int is_continuation(unsigned char c, struct tty_struct *tty)
+{
+ return I_IUTF8(tty) && is_utf8_continuation(c);
+}
+
+/**
+ * do_output_char - output one character
+ * @c: character (or partial unicode symbol)
+ * @tty: terminal device
+ * @space: space available in tty driver write buffer
+ *
+ * This is a helper function that handles one output character
+ * (including special characters like TAB, CR, LF, etc.),
+ * doing OPOST processing and putting the results in the
+ * tty driver's write buffer.
+ *
+ * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY
+ * and NLDLY. They simply aren't relevant in the world today.
+ * If you ever need them, add them here.
+ *
+ * Returns the number of bytes of buffer space used or -1 if
+ * no space left.
+ *
+ * Locking: should be called under the output_lock to protect
+ * the column state and space left in the buffer
+ */
+
+static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
+{
+ int spaces;
+
+ if (!space)
+ return -1;
+
+ switch (c) {
+ case '\n':
+ if (O_ONLRET(tty))
+ tty->column = 0;
+ if (O_ONLCR(tty)) {
+ if (space < 2)
+ return -1;
+ tty->canon_column = tty->column = 0;
+ tty->ops->write(tty, "\r\n", 2);
+ return 2;
+ }
+ tty->canon_column = tty->column;
+ break;
+ case '\r':
+ if (O_ONOCR(tty) && tty->column == 0)
+ return 0;
+ if (O_OCRNL(tty)) {
+ c = '\n';
+ if (O_ONLRET(tty))
+ tty->canon_column = tty->column = 0;
+ break;
+ }
+ tty->canon_column = tty->column = 0;
+ break;
+ case '\t':
+ spaces = 8 - (tty->column & 7);
+ if (O_TABDLY(tty) == XTABS) {
+ if (space < spaces)
+ return -1;
+ tty->column += spaces;
+ tty->ops->write(tty, " ", spaces);
+ return spaces;
+ }
+ tty->column += spaces;
+ break;
+ case '\b':
+ if (tty->column > 0)
+ tty->column--;
+ break;
+ default:
+ if (!iscntrl(c)) {
+ if (O_OLCUC(tty))
+ c = toupper(c);
+ if (!is_continuation(c, tty))
+ tty->column++;
+ }
+ break;
+ }
+
+ tty_put_char(tty, c);
+ return 1;
+}
+
+/**
+ * process_output - output post processor
+ * @c: character (or partial unicode symbol)
+ * @tty: terminal device
+ *
+ * Output one character with OPOST processing.
+ * Returns -1 when the output device is full and the character
+ * must be retried.
+ *
+ * Locking: output_lock to protect column state and space left
+ * (also, this is called from n_tty_write under the
+ * tty layer write lock)
+ */
+
+static int process_output(unsigned char c, struct tty_struct *tty)
+{
+ int space, retval;
+
+ mutex_lock(&tty->output_lock);
+
+ space = tty_write_room(tty);
+ retval = do_output_char(c, tty, space);
+
+ mutex_unlock(&tty->output_lock);
+ if (retval < 0)
+ return -1;
+ else
+ return 0;
+}
+
+/**
+ * process_output_block - block post processor
+ * @tty: terminal device
+ * @buf: character buffer
+ * @nr: number of bytes to output
+ *
+ * Output a block of characters with OPOST processing.
+ * Returns the number of characters output.
+ *
+ * This path is used to speed up block console writes, among other
+ * things when processing blocks of output data. It handles only
+ * the simple cases normally found and helps to generate blocks of
+ * symbols for the console driver and thus improve performance.
+ *
+ * Locking: output_lock to protect column state and space left
+ * (also, this is called from n_tty_write under the
+ * tty layer write lock)
+ */
+
+static ssize_t process_output_block(struct tty_struct *tty,
+ const unsigned char *buf, unsigned int nr)
+{
+ int space;
+ int i;
+ const unsigned char *cp;
+
+ mutex_lock(&tty->output_lock);
+
+ space = tty_write_room(tty);
+ if (!space) {
+ mutex_unlock(&tty->output_lock);
+ return 0;
+ }
+ if (nr > space)
+ nr = space;
+
+ for (i = 0, cp = buf; i < nr; i++, cp++) {
+ unsigned char c = *cp;
+
+ switch (c) {
+ case '\n':
+ if (O_ONLRET(tty))
+ tty->column = 0;
+ if (O_ONLCR(tty))
+ goto break_out;
+ tty->canon_column = tty->column;
+ break;
+ case '\r':
+ if (O_ONOCR(tty) && tty->column == 0)
+ goto break_out;
+ if (O_OCRNL(tty))
+ goto break_out;
+ tty->canon_column = tty->column = 0;
+ break;
+ case '\t':
+ goto break_out;
+ case '\b':
+ if (tty->column > 0)
+ tty->column--;
+ break;
+ default:
+ if (!iscntrl(c)) {
+ if (O_OLCUC(tty))
+ goto break_out;
+ if (!is_continuation(c, tty))
+ tty->column++;
+ }
+ break;
+ }
+ }
+break_out:
+ i = tty->ops->write(tty, buf, i);
+
+ mutex_unlock(&tty->output_lock);
+ return i;
+}
+
+/**
+ * process_echoes - write pending echo characters
+ * @tty: terminal device
+ *
+ * Write previously buffered echo (and other ldisc-generated)
+ * characters to the tty.
+ *
+ * Characters generated by the ldisc (including echoes) need to
+ * be buffered because the driver's write buffer can fill during
+ * heavy program output. Echoing straight to the driver will
+ * often fail under these conditions, causing lost characters and
+ * resulting mismatches of ldisc state information.
+ *
+ * Since the ldisc state must represent the characters actually sent
+ * to the driver at the time of the write, operations like certain
+ * changes in column state are also saved in the buffer and executed
+ * here.
+ *
+ * A circular fifo buffer is used so that the most recent characters
+ * are prioritized. Also, when control characters are echoed with a
+ * prefixed "^", the pair is treated atomically and thus not separated.
+ *
+ * Locking: output_lock to protect column state and space left,
+ * echo_lock to protect the echo buffer
+ */
+
+static void process_echoes(struct tty_struct *tty)
+{
+ int space, nr;
+ unsigned char c;
+ unsigned char *cp, *buf_end;
+
+ if (!tty->echo_cnt)
+ return;
+
+ mutex_lock(&tty->output_lock);
+ mutex_lock(&tty->echo_lock);
+
+ space = tty_write_room(tty);
+
+ buf_end = tty->echo_buf + N_TTY_BUF_SIZE;
+ cp = tty->echo_buf + tty->echo_pos;
+ nr = tty->echo_cnt;
+ while (nr > 0) {
+ c = *cp;
+ if (c == ECHO_OP_START) {
+ unsigned char op;
+ unsigned char *opp;
+ int no_space_left = 0;
+
+ /*
+ * If the buffer byte is the start of a multi-byte
+ * operation, get the next byte, which is either the
+ * op code or a control character value.
+ */
+ opp = cp + 1;
+ if (opp == buf_end)
+ opp -= N_TTY_BUF_SIZE;
+ op = *opp;
+
+ switch (op) {
+ unsigned int num_chars, num_bs;
+
+ case ECHO_OP_ERASE_TAB:
+ if (++opp == buf_end)
+ opp -= N_TTY_BUF_SIZE;
+ num_chars = *opp;
+
+ /*
+ * Determine how many columns to go back
+ * in order to erase the tab.
+ * This depends on the number of columns
+ * used by other characters within the tab
+ * area. If this (modulo 8) count is from
+ * the start of input rather than from a
+ * previous tab, we offset by canon column.
+ * Otherwise, tab spacing is normal.
+ */
+ if (!(num_chars & 0x80))
+ num_chars += tty->canon_column;
+ num_bs = 8 - (num_chars & 7);
+
+ if (num_bs > space) {
+ no_space_left = 1;
+ break;
+ }
+ space -= num_bs;
+ while (num_bs--) {
+ tty_put_char(tty, '\b');
+ if (tty->column > 0)
+ tty->column--;
+ }
+ cp += 3;
+ nr -= 3;
+ break;
+
+ case ECHO_OP_SET_CANON_COL:
+ tty->canon_column = tty->column;
+ cp += 2;
+ nr -= 2;
+ break;
+
+ case ECHO_OP_MOVE_BACK_COL:
+ if (tty->column > 0)
+ tty->column--;
+ cp += 2;
+ nr -= 2;
+ break;
+
+ case ECHO_OP_START:
+ /* This is an escaped echo op start code */
+ if (!space) {
+ no_space_left = 1;
+ break;
+ }
+ tty_put_char(tty, ECHO_OP_START);
+ tty->column++;
+ space--;
+ cp += 2;
+ nr -= 2;
+ break;
+
+ default:
+ /*
+ * If the op is not a special byte code,
+ * it is a ctrl char tagged to be echoed
+ * as "^X" (where X is the letter
+ * representing the control char).
+ * Note that we must ensure there is
+ * enough space for the whole ctrl pair.
+ *
+ */
+ if (space < 2) {
+ no_space_left = 1;
+ break;
+ }
+ tty_put_char(tty, '^');
+ tty_put_char(tty, op ^ 0100);
+ tty->column += 2;
+ space -= 2;
+ cp += 2;
+ nr -= 2;
+ }
+
+ if (no_space_left)
+ break;
+ } else {
+ if (O_OPOST(tty) &&
+ !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
+ int retval = do_output_char(c, tty, space);
+ if (retval < 0)
+ break;
+ space -= retval;
+ } else {
+ if (!space)
+ break;
+ tty_put_char(tty, c);
+ space -= 1;
+ }
+ cp += 1;
+ nr -= 1;
+ }
+
+ /* When end of circular buffer reached, wrap around */
+ if (cp >= buf_end)
+ cp -= N_TTY_BUF_SIZE;
+ }
+
+ if (nr == 0) {
+ tty->echo_pos = 0;
+ tty->echo_cnt = 0;
+ tty->echo_overrun = 0;
+ } else {
+ int num_processed = tty->echo_cnt - nr;
+ tty->echo_pos += num_processed;
+ tty->echo_pos &= N_TTY_BUF_SIZE - 1;
+ tty->echo_cnt = nr;
+ if (num_processed > 0)
+ tty->echo_overrun = 0;
+ }
+
+ mutex_unlock(&tty->echo_lock);
+ mutex_unlock(&tty->output_lock);
+
+ if (tty->ops->flush_chars)
+ tty->ops->flush_chars(tty);
+}
+
+/**
+ * add_echo_byte - add a byte to the echo buffer
+ * @c: unicode byte to echo
+ * @tty: terminal device
+ *
+ * Add a character or operation byte to the echo buffer.
+ *
+ * Should be called under the echo lock to protect the echo buffer.
+ */
+
+static void add_echo_byte(unsigned char c, struct tty_struct *tty)
+{
+ int new_byte_pos;
+
+ if (tty->echo_cnt == N_TTY_BUF_SIZE) {
+ /* Circular buffer is already at capacity */
+ new_byte_pos = tty->echo_pos;
+
+ /*
+ * Since the buffer start position needs to be advanced,
+ * be sure to step by a whole operation byte group.
+ */
+ if (tty->echo_buf[tty->echo_pos] == ECHO_OP_START) {
+ if (tty->echo_buf[(tty->echo_pos + 1) &
+ (N_TTY_BUF_SIZE - 1)] ==
+ ECHO_OP_ERASE_TAB) {
+ tty->echo_pos += 3;
+ tty->echo_cnt -= 2;
+ } else {
+ tty->echo_pos += 2;
+ tty->echo_cnt -= 1;
+ }
+ } else {
+ tty->echo_pos++;
+ }
+ tty->echo_pos &= N_TTY_BUF_SIZE - 1;
+
+ tty->echo_overrun = 1;
+ } else {
+ new_byte_pos = tty->echo_pos + tty->echo_cnt;
+ new_byte_pos &= N_TTY_BUF_SIZE - 1;
+ tty->echo_cnt++;
+ }
+
+ tty->echo_buf[new_byte_pos] = c;
+}
+
+/**
+ * echo_move_back_col - add operation to move back a column
+ * @tty: terminal device
+ *
+ * Add an operation to the echo buffer to move back one column.
+ *
+ * Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_move_back_col(struct tty_struct *tty)
+{
+ mutex_lock(&tty->echo_lock);
+
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_MOVE_BACK_COL, tty);
+
+ mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ * echo_set_canon_col - add operation to set the canon column
+ * @tty: terminal device
+ *
+ * Add an operation to the echo buffer to set the canon column
+ * to the current column.
+ *
+ * Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_set_canon_col(struct tty_struct *tty)
+{
+ mutex_lock(&tty->echo_lock);
+
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_SET_CANON_COL, tty);
+
+ mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ * echo_erase_tab - add operation to erase a tab
+ * @num_chars: number of character columns already used
+ * @after_tab: true if num_chars starts after a previous tab
+ * @tty: terminal device
+ *
+ * Add an operation to the echo buffer to erase a tab.
+ *
+ * Called by the eraser function, which knows how many character
+ * columns have been used since either a previous tab or the start
+ * of input. This information will be used later, along with
+ * canon column (if applicable), to go back the correct number
+ * of columns.
+ *
+ * Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_erase_tab(unsigned int num_chars, int after_tab,
+ struct tty_struct *tty)
+{
+ mutex_lock(&tty->echo_lock);
+
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_ERASE_TAB, tty);
+
+ /* We only need to know this modulo 8 (tab spacing) */
+ num_chars &= 7;
+
+ /* Set the high bit as a flag if num_chars is after a previous tab */
+ if (after_tab)
+ num_chars |= 0x80;
+
+ add_echo_byte(num_chars, tty);
+
+ mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ * echo_char_raw - echo a character raw
+ * @c: unicode byte to echo
+ * @tty: terminal device
+ *
+ * Echo user input back onto the screen. This must be called only when
+ * L_ECHO(tty) is true. Called from the driver receive_buf path.
+ *
+ * This variant does not treat control characters specially.
+ *
+ * Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_char_raw(unsigned char c, struct tty_struct *tty)
+{
+ mutex_lock(&tty->echo_lock);
+
+ if (c == ECHO_OP_START) {
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_START, tty);
+ } else {
+ add_echo_byte(c, tty);
+ }
+
+ mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ * echo_char - echo a character
+ * @c: unicode byte to echo
+ * @tty: terminal device
+ *
+ * Echo user input back onto the screen. This must be called only when
+ * L_ECHO(tty) is true. Called from the driver receive_buf path.
+ *
+ * This variant tags control characters to be echoed as "^X"
+ * (where X is the letter representing the control char).
+ *
+ * Locking: echo_lock to protect the echo buffer
+ */
+
+static void echo_char(unsigned char c, struct tty_struct *tty)
+{
+ mutex_lock(&tty->echo_lock);
+
+ if (c == ECHO_OP_START) {
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(ECHO_OP_START, tty);
+ } else {
+ if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t')
+ add_echo_byte(ECHO_OP_START, tty);
+ add_echo_byte(c, tty);
+ }
+
+ mutex_unlock(&tty->echo_lock);
+}
+
+/**
+ * finish_erasing - complete erase
+ * @tty: tty doing the erase
+ */
+
+static inline void finish_erasing(struct tty_struct *tty)
+{
+ if (tty->erasing) {
+ echo_char_raw('/', tty);
+ tty->erasing = 0;
+ }
+}
+
+/**
+ * eraser - handle erase function
+ * @c: character input
+ * @tty: terminal device
+ *
+ * Perform erase and necessary output when an erase character is
+ * present in the stream from the driver layer. Handles the complexities
+ * of UTF-8 multibyte symbols.
+ *
+ * Locking: read_lock for tty buffers
+ */
+
+static void eraser(unsigned char c, struct tty_struct *tty)
+{
+ enum { ERASE, WERASE, KILL } kill_type;
+ int head, seen_alnums, cnt;
+ unsigned long flags;
+
+ /* FIXME: locking needed ? */
+ if (tty->read_head == tty->canon_head) {
+ /* process_output('\a', tty); */ /* what do you think? */
+ return;
+ }
+ if (c == ERASE_CHAR(tty))
+ kill_type = ERASE;
+ else if (c == WERASE_CHAR(tty))
+ kill_type = WERASE;
+ else {
+ if (!L_ECHO(tty)) {
+ spin_lock_irqsave(&tty->read_lock, flags);
+ tty->read_cnt -= ((tty->read_head - tty->canon_head) &
+ (N_TTY_BUF_SIZE - 1));
+ tty->read_head = tty->canon_head;
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+ return;
+ }
+ if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) {
+ spin_lock_irqsave(&tty->read_lock, flags);
+ tty->read_cnt -= ((tty->read_head - tty->canon_head) &
+ (N_TTY_BUF_SIZE - 1));
+ tty->read_head = tty->canon_head;
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+ finish_erasing(tty);
+ echo_char(KILL_CHAR(tty), tty);
+ /* Add a newline if ECHOK is on and ECHOKE is off. */
+ if (L_ECHOK(tty))
+ echo_char_raw('\n', tty);
+ return;
+ }
+ kill_type = KILL;
+ }
+
+ seen_alnums = 0;
+ /* FIXME: Locking ?? */
+ while (tty->read_head != tty->canon_head) {
+ head = tty->read_head;
+
+ /* erase a single possibly multibyte character */
+ do {
+ head = (head - 1) & (N_TTY_BUF_SIZE-1);
+ c = tty->read_buf[head];
+ } while (is_continuation(c, tty) && head != tty->canon_head);
+
+ /* do not partially erase */
+ if (is_continuation(c, tty))
+ break;
+
+ if (kill_type == WERASE) {
+ /* Equivalent to BSD's ALTWERASE. */
+ if (isalnum(c) || c == '_')
+ seen_alnums++;
+ else if (seen_alnums)
+ break;
+ }
+ cnt = (tty->read_head - head) & (N_TTY_BUF_SIZE-1);
+ spin_lock_irqsave(&tty->read_lock, flags);
+ tty->read_head = head;
+ tty->read_cnt -= cnt;
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+ if (L_ECHO(tty)) {
+ if (L_ECHOPRT(tty)) {
+ if (!tty->erasing) {
+ echo_char_raw('\\', tty);
+ tty->erasing = 1;
+ }
+ /* if cnt > 1, output a multi-byte character */
+ echo_char(c, tty);
+ while (--cnt > 0) {
+ head = (head+1) & (N_TTY_BUF_SIZE-1);
+ echo_char_raw(tty->read_buf[head], tty);
+ echo_move_back_col(tty);
+ }
+ } else if (kill_type == ERASE && !L_ECHOE(tty)) {
+ echo_char(ERASE_CHAR(tty), tty);
+ } else if (c == '\t') {
+ unsigned int num_chars = 0;
+ int after_tab = 0;
+ unsigned long tail = tty->read_head;
+
+ /*
+ * Count the columns used for characters
+ * since the start of input or after a
+ * previous tab.
+ * This info is used to go back the correct
+ * number of columns.
+ */
+ while (tail != tty->canon_head) {
+ tail = (tail-1) & (N_TTY_BUF_SIZE-1);
+ c = tty->read_buf[tail];
+ if (c == '\t') {
+ after_tab = 1;
+ break;
+ } else if (iscntrl(c)) {
+ if (L_ECHOCTL(tty))
+ num_chars += 2;
+ } else if (!is_continuation(c, tty)) {
+ num_chars++;
+ }
+ }
+ echo_erase_tab(num_chars, after_tab, tty);
+ } else {
+ if (iscntrl(c) && L_ECHOCTL(tty)) {
+ echo_char_raw('\b', tty);
+ echo_char_raw(' ', tty);
+ echo_char_raw('\b', tty);
+ }
+ if (!iscntrl(c) || L_ECHOCTL(tty)) {
+ echo_char_raw('\b', tty);
+ echo_char_raw(' ', tty);
+ echo_char_raw('\b', tty);
+ }
+ }
+ }
+ if (kill_type == ERASE)
+ break;
+ }
+ if (tty->read_head == tty->canon_head && L_ECHO(tty))
+ finish_erasing(tty);
+}
+
+/**
+ * isig - handle the ISIG optio
+ * @sig: signal
+ * @tty: terminal
+ * @flush: force flush
+ *
+ * Called when a signal is being sent due to terminal input. This
+ * may caus terminal flushing to take place according to the termios
+ * settings and character used. Called from the driver receive_buf
+ * path so serialized.
+ *
+ * Locking: ctrl_lock, read_lock (both via flush buffer)
+ */
+
+static inline void isig(int sig, struct tty_struct *tty, int flush)
+{
+ if (tty->pgrp)
+ kill_pgrp(tty->pgrp, sig, 1);
+ if (flush || !L_NOFLSH(tty)) {
+ n_tty_flush_buffer(tty);
+ tty_driver_flush_buffer(tty);
+ }
+}
+
+/**
+ * n_tty_receive_break - handle break
+ * @tty: terminal
+ *
+ * An RS232 break event has been hit in the incoming bitstream. This
+ * can cause a variety of events depending upon the termios settings.
+ *
+ * Called from the receive_buf path so single threaded.
+ */
+
+static inline void n_tty_receive_break(struct tty_struct *tty)
+{
+ if (I_IGNBRK(tty))
+ return;
+ if (I_BRKINT(tty)) {
+ isig(SIGINT, tty, 1);
+ return;
+ }
+ if (I_PARMRK(tty)) {
+ put_tty_queue('\377', tty);
+ put_tty_queue('\0', tty);
+ }
+ put_tty_queue('\0', tty);
+ wake_up_interruptible(&tty->read_wait);
+}
+
+/**
+ * n_tty_receive_overrun - handle overrun reporting
+ * @tty: terminal
+ *
+ * Data arrived faster than we could process it. While the tty
+ * driver has flagged this the bits that were missed are gone
+ * forever.
+ *
+ * Called from the receive_buf path so single threaded. Does not
+ * need locking as num_overrun and overrun_time are function
+ * private.
+ */
+
+static inline void n_tty_receive_overrun(struct tty_struct *tty)
+{
+ char buf[64];
+
+ tty->num_overrun++;
+ if (time_before(tty->overrun_time, jiffies - HZ) ||
+ time_after(tty->overrun_time, jiffies)) {
+ printk(KERN_WARNING "%s: %d input overrun(s)\n",
+ tty_name(tty, buf),
+ tty->num_overrun);
+ tty->overrun_time = jiffies;
+ tty->num_overrun = 0;
+ }
+}
+
+/**
+ * n_tty_receive_parity_error - error notifier
+ * @tty: terminal device
+ * @c: character
+ *
+ * Process a parity error and queue the right data to indicate
+ * the error case if necessary. Locking as per n_tty_receive_buf.
+ */
+static inline void n_tty_receive_parity_error(struct tty_struct *tty,
+ unsigned char c)
+{
+ if (I_IGNPAR(tty))
+ return;
+ if (I_PARMRK(tty)) {
+ put_tty_queue('\377', tty);
+ put_tty_queue('\0', tty);
+ put_tty_queue(c, tty);
+ } else if (I_INPCK(tty))
+ put_tty_queue('\0', tty);
+ else
+ put_tty_queue(c, tty);
+ wake_up_interruptible(&tty->read_wait);
+}
+
+/**
+ * n_tty_receive_char - perform processing
+ * @tty: terminal device
+ * @c: character
+ *
+ * Process an individual character of input received from the driver.
+ * This is serialized with respect to itself by the rules for the
+ * driver above.
+ */
+
+static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
+{
+ unsigned long flags;
+ int parmrk;
+
+ if (tty->raw) {
+ put_tty_queue(c, tty);
+ return;
+ }
+
+ if (I_ISTRIP(tty))
+ c &= 0x7f;
+ if (I_IUCLC(tty) && L_IEXTEN(tty))
+ c = tolower(c);
+
+ if (L_EXTPROC(tty)) {
+ put_tty_queue(c, tty);
+ return;
+ }
+
+ if (tty->stopped && !tty->flow_stopped && I_IXON(tty) &&
+ I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty) &&
+ c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && c != SUSP_CHAR(tty)) {
+ start_tty(tty);
+ process_echoes(tty);
+ }
+
+ if (tty->closing) {
+ if (I_IXON(tty)) {
+ if (c == START_CHAR(tty)) {
+ start_tty(tty);
+ process_echoes(tty);
+ } else if (c == STOP_CHAR(tty))
+ stop_tty(tty);
+ }
+ return;
+ }
+
+ /*
+ * If the previous character was LNEXT, or we know that this
+ * character is not one of the characters that we'll have to
+ * handle specially, do shortcut processing to speed things
+ * up.
+ */
+ if (!test_bit(c, tty->process_char_map) || tty->lnext) {
+ tty->lnext = 0;
+ parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
+ if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
+ /* beep if no space */
+ if (L_ECHO(tty))
+ process_output('\a', tty);
+ return;
+ }
+ if (L_ECHO(tty)) {
+ finish_erasing(tty);
+ /* Record the column of first canon char. */
+ if (tty->canon_head == tty->read_head)
+ echo_set_canon_col(tty);
+ echo_char(c, tty);
+ process_echoes(tty);
+ }
+ if (parmrk)
+ put_tty_queue(c, tty);
+ put_tty_queue(c, tty);
+ return;
+ }
+
+ if (I_IXON(tty)) {
+ if (c == START_CHAR(tty)) {
+ start_tty(tty);
+ process_echoes(tty);
+ return;
+ }
+ if (c == STOP_CHAR(tty)) {
+ stop_tty(tty);
+ return;
+ }
+ }
+
+ if (L_ISIG(tty)) {
+ int signal;
+ signal = SIGINT;
+ if (c == INTR_CHAR(tty))
+ goto send_signal;
+ signal = SIGQUIT;
+ if (c == QUIT_CHAR(tty))
+ goto send_signal;
+ signal = SIGTSTP;
+ if (c == SUSP_CHAR(tty)) {
+send_signal:
+ /*
+ * Note that we do not use isig() here because we want
+ * the order to be:
+ * 1) flush, 2) echo, 3) signal
+ */
+ if (!L_NOFLSH(tty)) {
+ n_tty_flush_buffer(tty);
+ tty_driver_flush_buffer(tty);
+ }
+ if (I_IXON(tty))
+ start_tty(tty);
+ if (L_ECHO(tty)) {
+ echo_char(c, tty);
+ process_echoes(tty);
+ }
+ if (tty->pgrp)
+ kill_pgrp(tty->pgrp, signal, 1);
+ return;
+ }
+ }
+
+ if (c == '\r') {
+ if (I_IGNCR(tty))
+ return;
+ if (I_ICRNL(tty))
+ c = '\n';
+ } else if (c == '\n' && I_INLCR(tty))
+ c = '\r';
+
+ if (tty->icanon) {
+ if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
+ (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
+ eraser(c, tty);
+ process_echoes(tty);
+ return;
+ }
+ if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
+ tty->lnext = 1;
+ if (L_ECHO(tty)) {
+ finish_erasing(tty);
+ if (L_ECHOCTL(tty)) {
+ echo_char_raw('^', tty);
+ echo_char_raw('\b', tty);
+ process_echoes(tty);
+ }
+ }
+ return;
+ }
+ if (c == REPRINT_CHAR(tty) && L_ECHO(tty) &&
+ L_IEXTEN(tty)) {
+ unsigned long tail = tty->canon_head;
+
+ finish_erasing(tty);
+ echo_char(c, tty);
+ echo_char_raw('\n', tty);
+ while (tail != tty->read_head) {
+ echo_char(tty->read_buf[tail], tty);
+ tail = (tail+1) & (N_TTY_BUF_SIZE-1);
+ }
+ process_echoes(tty);
+ return;
+ }
+ if (c == '\n') {
+ if (tty->read_cnt >= N_TTY_BUF_SIZE) {
+ if (L_ECHO(tty))
+ process_output('\a', tty);
+ return;
+ }
+ if (L_ECHO(tty) || L_ECHONL(tty)) {
+ echo_char_raw('\n', tty);
+ process_echoes(tty);
+ }
+ goto handle_newline;
+ }
+ if (c == EOF_CHAR(tty)) {
+ if (tty->read_cnt >= N_TTY_BUF_SIZE)
+ return;
+ if (tty->canon_head != tty->read_head)
+ set_bit(TTY_PUSH, &tty->flags);
+ c = __DISABLED_CHAR;
+ goto handle_newline;
+ }
+ if ((c == EOL_CHAR(tty)) ||
+ (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
+ parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty))
+ ? 1 : 0;
+ if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk)) {
+ if (L_ECHO(tty))
+ process_output('\a', tty);
+ return;
+ }
+ /*
+ * XXX are EOL_CHAR and EOL2_CHAR echoed?!?
+ */
+ if (L_ECHO(tty)) {
+ /* Record the column of first canon char. */
+ if (tty->canon_head == tty->read_head)
+ echo_set_canon_col(tty);
+ echo_char(c, tty);
+ process_echoes(tty);
+ }
+ /*
+ * XXX does PARMRK doubling happen for
+ * EOL_CHAR and EOL2_CHAR?
+ */
+ if (parmrk)
+ put_tty_queue(c, tty);
+
+handle_newline:
+ spin_lock_irqsave(&tty->read_lock, flags);
+ set_bit(tty->read_head, tty->read_flags);
+ put_tty_queue_nolock(c, tty);
+ tty->canon_head = tty->read_head;
+ tty->canon_data++;
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+ kill_fasync(&tty->fasync, SIGIO, POLL_IN);
+ if (waitqueue_active(&tty->read_wait))
+ wake_up_interruptible(&tty->read_wait);
+ return;
+ }
+ }
+
+ parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
+ if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
+ /* beep if no space */
+ if (L_ECHO(tty))
+ process_output('\a', tty);
+ return;
+ }
+ if (L_ECHO(tty)) {
+ finish_erasing(tty);
+ if (c == '\n')
+ echo_char_raw('\n', tty);
+ else {
+ /* Record the column of first canon char. */
+ if (tty->canon_head == tty->read_head)
+ echo_set_canon_col(tty);
+ echo_char(c, tty);
+ }
+ process_echoes(tty);
+ }
+
+ if (parmrk)
+ put_tty_queue(c, tty);
+
+ put_tty_queue(c, tty);
+}
+
+
+/**
+ * n_tty_write_wakeup - asynchronous I/O notifier
+ * @tty: tty device
+ *
+ * Required for the ptys, serial driver etc. since processes
+ * that attach themselves to the master and rely on ASYNC
+ * IO must be woken up
+ */
+
+static void n_tty_write_wakeup(struct tty_struct *tty)
+{
+ if (tty->fasync && test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags))
+ kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
+}
+
+/**
+ * n_tty_receive_buf - data receive
+ * @tty: terminal device
+ * @cp: buffer
+ * @fp: flag buffer
+ * @count: characters
+ *
+ * Called by the terminal driver when a block of characters has
+ * been received. This function must be called from soft contexts
+ * not from interrupt context. The driver is responsible for making
+ * calls one at a time and in order (or using flush_to_ldisc)
+ */
+
+static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+ char *fp, int count)
+{
+ const unsigned char *p;
+ char *f, flags = TTY_NORMAL;
+ int i;
+ char buf[64];
+ unsigned long cpuflags;
+
+ if (!tty->read_buf)
+ return;
+
+ if (tty->real_raw) {
+ spin_lock_irqsave(&tty->read_lock, cpuflags);
+ i = min(N_TTY_BUF_SIZE - tty->read_cnt,
+ N_TTY_BUF_SIZE - tty->read_head);
+ i = min(count, i);
+ memcpy(tty->read_buf + tty->read_head, cp, i);
+ tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
+ tty->read_cnt += i;
+ cp += i;
+ count -= i;
+
+ i = min(N_TTY_BUF_SIZE - tty->read_cnt,
+ N_TTY_BUF_SIZE - tty->read_head);
+ i = min(count, i);
+ memcpy(tty->read_buf + tty->read_head, cp, i);
+ tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
+ tty->read_cnt += i;
+ spin_unlock_irqrestore(&tty->read_lock, cpuflags);
+ } else {
+ for (i = count, p = cp, f = fp; i; i--, p++) {
+ if (f)
+ flags = *f++;
+ switch (flags) {
+ case TTY_NORMAL:
+ n_tty_receive_char(tty, *p);
+ break;
+ case TTY_BREAK:
+ n_tty_receive_break(tty);
+ break;
+ case TTY_PARITY:
+ case TTY_FRAME:
+ n_tty_receive_parity_error(tty, *p);
+ break;
+ case TTY_OVERRUN:
+ n_tty_receive_overrun(tty);
+ break;
+ default:
+ printk(KERN_ERR "%s: unknown flag %d\n",
+ tty_name(tty, buf), flags);
+ break;
+ }
+ }
+ if (tty->ops->flush_chars)
+ tty->ops->flush_chars(tty);
+ }
+
+ n_tty_set_room(tty);
+
+ if ((!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) ||
+ L_EXTPROC(tty)) {
+ kill_fasync(&tty->fasync, SIGIO, POLL_IN);
+ if (waitqueue_active(&tty->read_wait))
+ wake_up_interruptible(&tty->read_wait);
+ }
+
+ /*
+ * Check the remaining room for the input canonicalization
+ * mode. We don't want to throttle the driver if we're in
+ * canonical mode and don't have a newline yet!
+ */
+ if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
+ tty_throttle(tty);
+}
+
+int is_ignored(int sig)
+{
+ return (sigismember(¤t->blocked, sig) ||
+ current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
+}
+
+/**
+ * n_tty_set_termios - termios data changed
+ * @tty: terminal
+ * @old: previous data
+ *
+ * Called by the tty layer when the user changes termios flags so
+ * that the line discipline can plan ahead. This function cannot sleep
+ * and is protected from re-entry by the tty layer. The user is
+ * guaranteed that this function will not be re-entered or in progress
+ * when the ldisc is closed.
+ *
+ * Locking: Caller holds tty->termios_mutex
+ */
+
+static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
+{
+ int canon_change = 1;
+ BUG_ON(!tty);
+
+ if (old)
+ canon_change = (old->c_lflag ^ tty->termios->c_lflag) & ICANON;
+ if (canon_change) {
+ memset(&tty->read_flags, 0, sizeof tty->read_flags);
+ tty->canon_head = tty->read_tail;
+ tty->canon_data = 0;
+ tty->erasing = 0;
+ }
+
+ if (canon_change && !L_ICANON(tty) && tty->read_cnt)
+ wake_up_interruptible(&tty->read_wait);
+
+ tty->icanon = (L_ICANON(tty) != 0);
+ if (test_bit(TTY_HW_COOK_IN, &tty->flags)) {
+ tty->raw = 1;
+ tty->real_raw = 1;
+ n_tty_set_room(tty);
+ return;
+ }
+ if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) ||
+ I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) ||
+ I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) ||
+ I_PARMRK(tty)) {
+ memset(tty->process_char_map, 0, 256/8);
+
+ if (I_IGNCR(tty) || I_ICRNL(tty))
+ set_bit('\r', tty->process_char_map);
+ if (I_INLCR(tty))
+ set_bit('\n', tty->process_char_map);
+
+ if (L_ICANON(tty)) {
+ set_bit(ERASE_CHAR(tty), tty->process_char_map);
+ set_bit(KILL_CHAR(tty), tty->process_char_map);
+ set_bit(EOF_CHAR(tty), tty->process_char_map);
+ set_bit('\n', tty->process_char_map);
+ set_bit(EOL_CHAR(tty), tty->process_char_map);
+ if (L_IEXTEN(tty)) {
+ set_bit(WERASE_CHAR(tty),
+ tty->process_char_map);
+ set_bit(LNEXT_CHAR(tty),
+ tty->process_char_map);
+ set_bit(EOL2_CHAR(tty),
+ tty->process_char_map);
+ if (L_ECHO(tty))
+ set_bit(REPRINT_CHAR(tty),
+ tty->process_char_map);
+ }
+ }
+ if (I_IXON(tty)) {
+ set_bit(START_CHAR(tty), tty->process_char_map);
+ set_bit(STOP_CHAR(tty), tty->process_char_map);
+ }
+ if (L_ISIG(tty)) {
+ set_bit(INTR_CHAR(tty), tty->process_char_map);
+ set_bit(QUIT_CHAR(tty), tty->process_char_map);
+ set_bit(SUSP_CHAR(tty), tty->process_char_map);
+ }
+ clear_bit(__DISABLED_CHAR, tty->process_char_map);
+ tty->raw = 0;
+ tty->real_raw = 0;
+ } else {
+ tty->raw = 1;
+ if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) &&
+ (I_IGNPAR(tty) || !I_INPCK(tty)) &&
+ (tty->driver->flags & TTY_DRIVER_REAL_RAW))
+ tty->real_raw = 1;
+ else
+ tty->real_raw = 0;
+ }
+ n_tty_set_room(tty);
+ /* The termios change make the tty ready for I/O */
+ wake_up_interruptible(&tty->write_wait);
+ wake_up_interruptible(&tty->read_wait);
+}
+
+/**
+ * n_tty_close - close the ldisc for this tty
+ * @tty: device
+ *
+ * Called from the terminal layer when this line discipline is
+ * being shut down, either because of a close or becsuse of a
+ * discipline change. The function will not be called while other
+ * ldisc methods are in progress.
+ */
+
+static void n_tty_close(struct tty_struct *tty)
+{
+ n_tty_flush_buffer(tty);
+ if (tty->read_buf) {
+ kfree(tty->read_buf);
+ tty->read_buf = NULL;
+ }
+ if (tty->echo_buf) {
+ kfree(tty->echo_buf);
+ tty->echo_buf = NULL;
+ }
+}
+
+/**
+ * n_tty_open - open an ldisc
+ * @tty: terminal to open
+ *
+ * Called when this line discipline is being attached to the
+ * terminal device. Can sleep. Called serialized so that no
+ * other events will occur in parallel. No further open will occur
+ * until a close.
+ */
+
+static int n_tty_open(struct tty_struct *tty)
+{
+ if (!tty)
+ return -EINVAL;
+
+ /* These are ugly. Currently a malloc failure here can panic */
+ if (!tty->read_buf) {
+ tty->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
+ if (!tty->read_buf)
+ return -ENOMEM;
+ }
+ if (!tty->echo_buf) {
+ tty->echo_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
+
+ if (!tty->echo_buf)
+ return -ENOMEM;
+ }
+ reset_buffer_flags(tty);
+ tty->column = 0;
+ n_tty_set_termios(tty, NULL);
+ tty->minimum_to_wake = 1;
+ tty->closing = 0;
+ return 0;
+}
+
+static inline int input_available_p(struct tty_struct *tty, int amt)
+{
+ tty_flush_to_ldisc(tty);
+ if (tty->icanon && !L_EXTPROC(tty)) {
+ if (tty->canon_data)
+ return 1;
+ } else if (tty->read_cnt >= (amt ? amt : 1))
+ return 1;
+
+ return 0;
+}
+
+/**
+ * copy_from_read_buf - copy read data directly
+ * @tty: terminal device
+ * @b: user data
+ * @nr: size of data
+ *
+ * Helper function to speed up n_tty_read. It is only called when
+ * ICANON is off; it copies characters straight from the tty queue to
+ * user space directly. It can be profitably called twice; once to
+ * drain the space from the tail pointer to the (physical) end of the
+ * buffer, and once to drain the space from the (physical) beginning of
+ * the buffer to head pointer.
+ *
+ * Called under the tty->atomic_read_lock sem
+ *
+ */
+
+static int copy_from_read_buf(struct tty_struct *tty,
+ unsigned char __user **b,
+ size_t *nr)
+
+{
+ int retval;
+ size_t n;
+ unsigned long flags;
+
+ retval = 0;
+ spin_lock_irqsave(&tty->read_lock, flags);
+ n = min(tty->read_cnt, N_TTY_BUF_SIZE - tty->read_tail);
+ n = min(*nr, n);
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+ if (n) {
+ retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n);
+ n -= retval;
+ tty_audit_add_data(tty, &tty->read_buf[tty->read_tail], n);
+ spin_lock_irqsave(&tty->read_lock, flags);
+ tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1);
+ tty->read_cnt -= n;
+ /* Turn single EOF into zero-length read */
+ if (L_EXTPROC(tty) && tty->icanon && n == 1) {
+ if (!tty->read_cnt && (*b)[n-1] == EOF_CHAR(tty))
+ n--;
+ }
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+ *b += n;
+ *nr -= n;
+ }
+ return retval;
+}
+
+extern ssize_t redirected_tty_write(struct file *, const char __user *,
+ size_t, loff_t *);
+
+/**
+ * job_control - check job control
+ * @tty: tty
+ * @file: file handle
+ *
+ * Perform job control management checks on this file/tty descriptor
+ * and if appropriate send any needed signals and return a negative
+ * error code if action should be taken.
+ *
+ * FIXME:
+ * Locking: None - redirected write test is safe, testing
+ * current->signal should possibly lock current->sighand
+ * pgrp locking ?
+ */
+
+static int job_control(struct tty_struct *tty, struct file *file)
+{
+ /* Job control check -- must be done at start and after
+ every sleep (POSIX.1 7.1.1.4). */
+ /* NOTE: not yet done after every sleep pending a thorough
+ check of the logic of this change. -- jlc */
+ /* don't stop on /dev/console */
+ if (file->f_op->write != redirected_tty_write &&
+ current->signal->tty == tty) {
+ if (!tty->pgrp)
+ printk(KERN_ERR "n_tty_read: no tty->pgrp!\n");
+ else if (task_pgrp(current) != tty->pgrp) {
+ if (is_ignored(SIGTTIN) ||
+ is_current_pgrp_orphaned())
+ return -EIO;
+ kill_pgrp(task_pgrp(current), SIGTTIN, 1);
+ set_thread_flag(TIF_SIGPENDING);
+ return -ERESTARTSYS;
+ }
+ }
+ return 0;
+}
+
+
+/**
+ * n_tty_read - read function for tty
+ * @tty: tty device
+ * @file: file object
+ * @buf: userspace buffer pointer
+ * @nr: size of I/O
+ *
+ * Perform reads for the line discipline. We are guaranteed that the
+ * line discipline will not be closed under us but we may get multiple
+ * parallel readers and must handle this ourselves. We may also get
+ * a hangup. Always called in user context, may sleep.
+ *
+ * This code must be sure never to sleep through a hangup.
+ */
+
+static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
+ unsigned char __user *buf, size_t nr)
+{
+ unsigned char __user *b = buf;
+ DECLARE_WAITQUEUE(wait, current);
+ int c;
+ int minimum, time;
+ ssize_t retval = 0;
+ ssize_t size;
+ long timeout;
+ unsigned long flags;
+ int packet;
+
+do_it_again:
+
+ BUG_ON(!tty->read_buf);
+
+ c = job_control(tty, file);
+ if (c < 0)
+ return c;
+
+ minimum = time = 0;
+ timeout = MAX_SCHEDULE_TIMEOUT;
+ if (!tty->icanon) {
+ time = (HZ / 10) * TIME_CHAR(tty);
+ minimum = MIN_CHAR(tty);
+ if (minimum) {
+ if (time)
+ tty->minimum_to_wake = 1;
+ else if (!waitqueue_active(&tty->read_wait) ||
+ (tty->minimum_to_wake > minimum))
+ tty->minimum_to_wake = minimum;
+ } else {
+ timeout = 0;
+ if (time) {
+ timeout = time;
+ time = 0;
+ }
+ tty->minimum_to_wake = minimum = 1;
+ }
+ }
+
+ /*
+ * Internal serialization of reads.
+ */
+ if (file->f_flags & O_NONBLOCK) {
+ if (!mutex_trylock(&tty->atomic_read_lock))
+ return -EAGAIN;
+ } else {
+ if (mutex_lock_interruptible(&tty->atomic_read_lock))
+ return -ERESTARTSYS;
+ }
+ packet = tty->packet;
+
+ add_wait_queue(&tty->read_wait, &wait);
+ while (nr) {
+ /* First test for status change. */
+ if (packet && tty->link->ctrl_status) {
+ unsigned char cs;
+ if (b != buf)
+ break;
+ spin_lock_irqsave(&tty->link->ctrl_lock, flags);
+ cs = tty->link->ctrl_status;
+ tty->link->ctrl_status = 0;
+ spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
+ if (tty_put_user(tty, cs, b++)) {
+ retval = -EFAULT;
+ b--;
+ break;
+ }
+ nr--;
+ break;
+ }
+ /* This statement must be first before checking for input
+ so that any interrupt will set the state back to
+ TASK_RUNNING. */
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
+ ((minimum - (b - buf)) >= 1))
+ tty->minimum_to_wake = (minimum - (b - buf));
+
+ if (!input_available_p(tty, 0)) {
+ if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
+ retval = -EIO;
+ break;
+ }
+ if (tty_hung_up_p(file))
+ break;
+ if (!timeout)
+ break;
+ if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ break;
+ }
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ break;
+ }
+ /* FIXME: does n_tty_set_room need locking ? */
+ n_tty_set_room(tty);
+ timeout = schedule_timeout(timeout);
+ continue;
+ }
+ __set_current_state(TASK_RUNNING);
+
+ /* Deal with packet mode. */
+ if (packet && b == buf) {
+ if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
+ retval = -EFAULT;
+ b--;
+ break;
+ }
+ nr--;
+ }
+
+ if (tty->icanon && !L_EXTPROC(tty)) {
+ /* N.B. avoid overrun if nr == 0 */
+ while (nr && tty->read_cnt) {
+ int eol;
+
+ eol = test_and_clear_bit(tty->read_tail,
+ tty->read_flags);
+ c = tty->read_buf[tty->read_tail];
+ spin_lock_irqsave(&tty->read_lock, flags);
+ tty->read_tail = ((tty->read_tail+1) &
+ (N_TTY_BUF_SIZE-1));
+ tty->read_cnt--;
+ if (eol) {
+ /* this test should be redundant:
+ * we shouldn't be reading data if
+ * canon_data is 0
+ */
+ if (--tty->canon_data < 0)
+ tty->canon_data = 0;
+ }
+ spin_unlock_irqrestore(&tty->read_lock, flags);
+
+ if (!eol || (c != __DISABLED_CHAR)) {
+ if (tty_put_user(tty, c, b++)) {
+ retval = -EFAULT;
+ b--;
+ break;
+ }
+ nr--;
+ }
+ if (eol) {
+ tty_audit_push(tty);
+ break;
+ }
+ }
+ if (retval)
+ break;
+ } else {
+ int uncopied;
+ /* The copy function takes the read lock and handles
+ locking internally for this case */
+ uncopied = copy_from_read_buf(tty, &b, &nr);
+ uncopied += copy_from_read_buf(tty, &b, &nr);
+ if (uncopied) {
+ retval = -EFAULT;
+ break;
+ }
+ }
+
+ /* If there is enough space in the read buffer now, let the
+ * low-level driver know. We use n_tty_chars_in_buffer() to
+ * check the buffer, as it now knows about canonical mode.
+ * Otherwise, if the driver is throttled and the line is
+ * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
+ * we won't get any more characters.
+ */
+ if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) {
+ n_tty_set_room(tty);
+ check_unthrottle(tty);
+ }
+
+ if (b - buf >= minimum)
+ break;
+ if (time)
+ timeout = time;
+ }
+ mutex_unlock(&tty->atomic_read_lock);
+ remove_wait_queue(&tty->read_wait, &wait);
+
+ if (!waitqueue_active(&tty->read_wait))
+ tty->minimum_to_wake = minimum;
+
+ __set_current_state(TASK_RUNNING);
+ size = b - buf;
+ if (size) {
+ retval = size;
+ if (nr)
+ clear_bit(TTY_PUSH, &tty->flags);
+ } else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
+ goto do_it_again;
+
+ n_tty_set_room(tty);
+ return retval;
+}
+
+/**
+ * n_tty_write - write function for tty
+ * @tty: tty device
+ * @file: file object
+ * @buf: userspace buffer pointer
+ * @nr: size of I/O
+ *
+ * Write function of the terminal device. This is serialized with
+ * respect to other write callers but not to termios changes, reads
+ * and other such events. Since the receive code will echo characters,
+ * thus calling driver write methods, the output_lock is used in
+ * the output processing functions called here as well as in the
+ * echo processing function to protect the column state and space
+ * left in the buffer.
+ *
+ * This code must be sure never to sleep through a hangup.
+ *
+ * Locking: output_lock to protect column state and space left
+ * (note that the process_output*() functions take this
+ * lock themselves)
+ */
+
+static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
+ const unsigned char *buf, size_t nr)
+{
+ const unsigned char *b = buf;
+ DECLARE_WAITQUEUE(wait, current);
+ int c;
+ ssize_t retval = 0;
+
+ /* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
+ if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) {
+ retval = tty_check_change(tty);
+ if (retval)
+ return retval;
+ }
+
+ /* Write out any echoed characters that are still pending */
+ process_echoes(tty);
+
+ add_wait_queue(&tty->write_wait, &wait);
+ while (1) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ break;
+ }
+ if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
+ retval = -EIO;
+ break;
+ }
+ if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
+ while (nr > 0) {
+ ssize_t num = process_output_block(tty, b, nr);
+ if (num < 0) {
+ if (num == -EAGAIN)
+ break;
+ retval = num;
+ goto break_out;
+ }
+ b += num;
+ nr -= num;
+ if (nr == 0)
+ break;
+ c = *b;
+ if (process_output(c, tty) < 0)
+ break;
+ b++; nr--;
+ }
+ if (tty->ops->flush_chars)
+ tty->ops->flush_chars(tty);
+ } else {
+ while (nr > 0) {
+ c = tty->ops->write(tty, b, nr);
+ if (c < 0) {
+ retval = c;
+ goto break_out;
+ }
+ if (!c)
+ break;
+ b += c;
+ nr -= c;
+ }
+ }
+ if (!nr)
+ break;
+ if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ break;
+ }
+ schedule();
+ }
+break_out:
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&tty->write_wait, &wait);
+ if (b - buf != nr && tty->fasync)
+ set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+ return (b - buf) ? b - buf : retval;
+}
+
+/**
+ * n_tty_poll - poll method for N_TTY
+ * @tty: terminal device
+ * @file: file accessing it
+ * @wait: poll table
+ *
+ * Called when the line discipline is asked to poll() for data or
+ * for special events. This code is not serialized with respect to
+ * other events save open/close.
+ *
+ * This code must be sure never to sleep through a hangup.
+ * Called without the kernel lock held - fine
+ */
+
+static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
+ poll_table *wait)
+{
+ unsigned int mask = 0;
+
+ poll_wait(file, &tty->read_wait, wait);
+ poll_wait(file, &tty->write_wait, wait);
+ if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty)))
+ mask |= POLLIN | POLLRDNORM;
+ if (tty->packet && tty->link->ctrl_status)
+ mask |= POLLPRI | POLLIN | POLLRDNORM;
+ if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+ mask |= POLLHUP;
+ if (tty_hung_up_p(file))
+ mask |= POLLHUP;
+ if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) {
+ if (MIN_CHAR(tty) && !TIME_CHAR(tty))
+ tty->minimum_to_wake = MIN_CHAR(tty);
+ else
+ tty->minimum_to_wake = 1;
+ }
+ if (tty->ops->write && !tty_is_writelocked(tty) &&
+ tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
+ tty_write_room(tty) > 0)
+ mask |= POLLOUT | POLLWRNORM;
+ return mask;
+}
+
+static unsigned long inq_canon(struct tty_struct *tty)
+{
+ int nr, head, tail;
+
+ if (!tty->canon_data)
+ return 0;
+ head = tty->canon_head;
+ tail = tty->read_tail;
+ nr = (head - tail) & (N_TTY_BUF_SIZE-1);
+ /* Skip EOF-chars.. */
+ while (head != tail) {
+ if (test_bit(tail, tty->read_flags) &&
+ tty->read_buf[tail] == __DISABLED_CHAR)
+ nr--;
+ tail = (tail+1) & (N_TTY_BUF_SIZE-1);
+ }
+ return nr;
+}
+
+static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int retval;
+
+ switch (cmd) {
+ case TIOCOUTQ:
+ return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
+ case TIOCINQ:
+ /* FIXME: Locking */
+ retval = tty->read_cnt;
+ if (L_ICANON(tty))
+ retval = inq_canon(tty);
+ return put_user(retval, (unsigned int __user *) arg);
+ default:
+ return n_tty_ioctl_helper(tty, file, cmd, arg);
+ }
+}
+
+struct tty_ldisc_ops tty_ldisc_N_TTY = {
+ .magic = TTY_LDISC_MAGIC,
+ .name = "n_tty",
+ .open = n_tty_open,
+ .close = n_tty_close,
+ .flush_buffer = n_tty_flush_buffer,
+ .chars_in_buffer = n_tty_chars_in_buffer,
+ .read = n_tty_read,
+ .write = n_tty_write,
+ .ioctl = n_tty_ioctl,
+ .set_termios = n_tty_set_termios,
+ .poll = n_tty_poll,
+ .receive_buf = n_tty_receive_buf,
+ .write_wakeup = n_tty_write_wakeup
+};
+
+/**
+ * n_tty_inherit_ops - inherit N_TTY methods
+ * @ops: struct tty_ldisc_ops where to save N_TTY methods
+ *
+ * Used by a generic struct tty_ldisc_ops to easily inherit N_TTY
+ * methods.
+ */
+
+void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
+{
+ *ops = tty_ldisc_N_TTY;
+ ops->owner = NULL;
+ ops->refcount = ops->flags = 0;
+}
+EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
--- /dev/null
+/*
+ * linux/drivers/char/pty.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Added support for a Unix98-style ptmx device.
+ * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
+ *
+ * When reading this code see also fs/devpts. In particular note that the
+ * driver_data field is used by the devpts side as a binding to the devpts
+ * inode.
+ */
+
+#include <linux/module.h>
+
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/major.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/smp_lock.h>
+#include <linux/sysctl.h>
+#include <linux/device.h>
+#include <linux/uaccess.h>
+#include <linux/bitops.h>
+#include <linux/devpts_fs.h>
+#include <linux/slab.h>
+
+#include <asm/system.h>
+
+#ifdef CONFIG_UNIX98_PTYS
+static struct tty_driver *ptm_driver;
+static struct tty_driver *pts_driver;
+#endif
+
+static void pty_close(struct tty_struct *tty, struct file *filp)
+{
+ BUG_ON(!tty);
+ if (tty->driver->subtype == PTY_TYPE_MASTER)
+ WARN_ON(tty->count > 1);
+ else {
+ if (tty->count > 2)
+ return;
+ }
+ wake_up_interruptible(&tty->read_wait);
+ wake_up_interruptible(&tty->write_wait);
+ tty->packet = 0;
+ if (!tty->link)
+ return;
+ tty->link->packet = 0;
+ set_bit(TTY_OTHER_CLOSED, &tty->link->flags);
+ wake_up_interruptible(&tty->link->read_wait);
+ wake_up_interruptible(&tty->link->write_wait);
+ if (tty->driver->subtype == PTY_TYPE_MASTER) {
+ set_bit(TTY_OTHER_CLOSED, &tty->flags);
+#ifdef CONFIG_UNIX98_PTYS
+ if (tty->driver == ptm_driver)
+ devpts_pty_kill(tty->link);
+#endif
+ tty_unlock();
+ tty_vhangup(tty->link);
+ tty_lock();
+ }
+}
+
+/*
+ * The unthrottle routine is called by the line discipline to signal
+ * that it can receive more characters. For PTY's, the TTY_THROTTLED
+ * flag is always set, to force the line discipline to always call the
+ * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
+ * characters in the queue. This is necessary since each time this
+ * happens, we need to wake up any sleeping processes that could be
+ * (1) trying to send data to the pty, or (2) waiting in wait_until_sent()
+ * for the pty buffer to be drained.
+ */
+static void pty_unthrottle(struct tty_struct *tty)
+{
+ tty_wakeup(tty->link);
+ set_bit(TTY_THROTTLED, &tty->flags);
+}
+
+/**
+ * pty_space - report space left for writing
+ * @to: tty we are writing into
+ *
+ * The tty buffers allow 64K but we sneak a peak and clip at 8K this
+ * allows a lot of overspill room for echo and other fun messes to
+ * be handled properly
+ */
+
+static int pty_space(struct tty_struct *to)
+{
+ int n = 8192 - to->buf.memory_used;
+ if (n < 0)
+ return 0;
+ return n;
+}
+
+/**
+ * pty_write - write to a pty
+ * @tty: the tty we write from
+ * @buf: kernel buffer of data
+ * @count: bytes to write
+ *
+ * Our "hardware" write method. Data is coming from the ldisc which
+ * may be in a non sleeping state. We simply throw this at the other
+ * end of the link as if we were an IRQ handler receiving stuff for
+ * the other side of the pty/tty pair.
+ */
+
+static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
+{
+ struct tty_struct *to = tty->link;
+
+ if (tty->stopped)
+ return 0;
+
+ if (c > 0) {
+ /* Stuff the data into the input queue of the other end */
+ c = tty_insert_flip_string(to, buf, c);
+ /* And shovel */
+ if (c) {
+ tty_flip_buffer_push(to);
+ tty_wakeup(tty);
+ }
+ }
+ return c;
+}
+
+/**
+ * pty_write_room - write space
+ * @tty: tty we are writing from
+ *
+ * Report how many bytes the ldisc can send into the queue for
+ * the other device.
+ */
+
+static int pty_write_room(struct tty_struct *tty)
+{
+ if (tty->stopped)
+ return 0;
+ return pty_space(tty->link);
+}
+
+/**
+ * pty_chars_in_buffer - characters currently in our tx queue
+ * @tty: our tty
+ *
+ * Report how much we have in the transmit queue. As everything is
+ * instantly at the other end this is easy to implement.
+ */
+
+static int pty_chars_in_buffer(struct tty_struct *tty)
+{
+ return 0;
+}
+
+/* Set the lock flag on a pty */
+static int pty_set_lock(struct tty_struct *tty, int __user *arg)
+{
+ int val;
+ if (get_user(val, arg))
+ return -EFAULT;
+ if (val)
+ set_bit(TTY_PTY_LOCK, &tty->flags);
+ else
+ clear_bit(TTY_PTY_LOCK, &tty->flags);
+ return 0;
+}
+
+/* Send a signal to the slave */
+static int pty_signal(struct tty_struct *tty, int sig)
+{
+ unsigned long flags;
+ struct pid *pgrp;
+
+ if (tty->link) {
+ spin_lock_irqsave(&tty->link->ctrl_lock, flags);
+ pgrp = get_pid(tty->link->pgrp);
+ spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
+
+ kill_pgrp(pgrp, sig, 1);
+ put_pid(pgrp);
+ }
+ return 0;
+}
+
+static void pty_flush_buffer(struct tty_struct *tty)
+{
+ struct tty_struct *to = tty->link;
+ unsigned long flags;
+
+ if (!to)
+ return;
+ /* tty_buffer_flush(to); FIXME */
+ if (to->packet) {
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
+ wake_up_interruptible(&to->read_wait);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ }
+}
+
+static int pty_open(struct tty_struct *tty, struct file *filp)
+{
+ int retval = -ENODEV;
+
+ if (!tty || !tty->link)
+ goto out;
+
+ retval = -EIO;
+ if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
+ goto out;
+ if (test_bit(TTY_PTY_LOCK, &tty->link->flags))
+ goto out;
+ if (tty->link->count != 1)
+ goto out;
+
+ clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
+ set_bit(TTY_THROTTLED, &tty->flags);
+ retval = 0;
+out:
+ return retval;
+}
+
+static void pty_set_termios(struct tty_struct *tty,
+ struct ktermios *old_termios)
+{
+ tty->termios->c_cflag &= ~(CSIZE | PARENB);
+ tty->termios->c_cflag |= (CS8 | CREAD);
+}
+
+/**
+ * pty_do_resize - resize event
+ * @tty: tty being resized
+ * @ws: window size being set.
+ *
+ * Update the termios variables and send the necessary signals to
+ * peform a terminal resize correctly
+ */
+
+int pty_resize(struct tty_struct *tty, struct winsize *ws)
+{
+ struct pid *pgrp, *rpgrp;
+ unsigned long flags;
+ struct tty_struct *pty = tty->link;
+
+ /* For a PTY we need to lock the tty side */
+ mutex_lock(&tty->termios_mutex);
+ if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
+ goto done;
+
+ /* Get the PID values and reference them so we can
+ avoid holding the tty ctrl lock while sending signals.
+ We need to lock these individually however. */
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ pgrp = get_pid(tty->pgrp);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+ spin_lock_irqsave(&pty->ctrl_lock, flags);
+ rpgrp = get_pid(pty->pgrp);
+ spin_unlock_irqrestore(&pty->ctrl_lock, flags);
+
+ if (pgrp)
+ kill_pgrp(pgrp, SIGWINCH, 1);
+ if (rpgrp != pgrp && rpgrp)
+ kill_pgrp(rpgrp, SIGWINCH, 1);
+
+ put_pid(pgrp);
+ put_pid(rpgrp);
+
+ tty->winsize = *ws;
+ pty->winsize = *ws; /* Never used so will go away soon */
+done:
+ mutex_unlock(&tty->termios_mutex);
+ return 0;
+}
+
+/* Traditional BSD devices */
+#ifdef CONFIG_LEGACY_PTYS
+
+static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+ struct tty_struct *o_tty;
+ int idx = tty->index;
+ int retval;
+
+ o_tty = alloc_tty_struct();
+ if (!o_tty)
+ return -ENOMEM;
+ if (!try_module_get(driver->other->owner)) {
+ /* This cannot in fact currently happen */
+ free_tty_struct(o_tty);
+ return -ENOMEM;
+ }
+ initialize_tty_struct(o_tty, driver->other, idx);
+
+ /* We always use new tty termios data so we can do this
+ the easy way .. */
+ retval = tty_init_termios(tty);
+ if (retval)
+ goto free_mem_out;
+
+ retval = tty_init_termios(o_tty);
+ if (retval) {
+ tty_free_termios(tty);
+ goto free_mem_out;
+ }
+
+ /*
+ * Everything allocated ... set up the o_tty structure.
+ */
+ driver->other->ttys[idx] = o_tty;
+ tty_driver_kref_get(driver->other);
+ if (driver->subtype == PTY_TYPE_MASTER)
+ o_tty->count++;
+ /* Establish the links in both directions */
+ tty->link = o_tty;
+ o_tty->link = tty;
+
+ tty_driver_kref_get(driver);
+ tty->count++;
+ driver->ttys[idx] = tty;
+ return 0;
+free_mem_out:
+ module_put(o_tty->driver->owner);
+ free_tty_struct(o_tty);
+ return -ENOMEM;
+}
+
+static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+ case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
+ return pty_set_lock(tty, (int __user *) arg);
+ case TIOCSIG: /* Send signal to other side of pty */
+ return pty_signal(tty, (int) arg);
+ }
+ return -ENOIOCTLCMD;
+}
+
+static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
+module_param(legacy_count, int, 0);
+
+/*
+ * The master side of a pty can do TIOCSPTLCK and thus
+ * has pty_bsd_ioctl.
+ */
+static const struct tty_operations master_pty_ops_bsd = {
+ .install = pty_install,
+ .open = pty_open,
+ .close = pty_close,
+ .write = pty_write,
+ .write_room = pty_write_room,
+ .flush_buffer = pty_flush_buffer,
+ .chars_in_buffer = pty_chars_in_buffer,
+ .unthrottle = pty_unthrottle,
+ .set_termios = pty_set_termios,
+ .ioctl = pty_bsd_ioctl,
+ .resize = pty_resize
+};
+
+static const struct tty_operations slave_pty_ops_bsd = {
+ .install = pty_install,
+ .open = pty_open,
+ .close = pty_close,
+ .write = pty_write,
+ .write_room = pty_write_room,
+ .flush_buffer = pty_flush_buffer,
+ .chars_in_buffer = pty_chars_in_buffer,
+ .unthrottle = pty_unthrottle,
+ .set_termios = pty_set_termios,
+ .resize = pty_resize
+};
+
+static void __init legacy_pty_init(void)
+{
+ struct tty_driver *pty_driver, *pty_slave_driver;
+
+ if (legacy_count <= 0)
+ return;
+
+ pty_driver = alloc_tty_driver(legacy_count);
+ if (!pty_driver)
+ panic("Couldn't allocate pty driver");
+
+ pty_slave_driver = alloc_tty_driver(legacy_count);
+ if (!pty_slave_driver)
+ panic("Couldn't allocate pty slave driver");
+
+ pty_driver->owner = THIS_MODULE;
+ pty_driver->driver_name = "pty_master";
+ pty_driver->name = "pty";
+ pty_driver->major = PTY_MASTER_MAJOR;
+ pty_driver->minor_start = 0;
+ pty_driver->type = TTY_DRIVER_TYPE_PTY;
+ pty_driver->subtype = PTY_TYPE_MASTER;
+ pty_driver->init_termios = tty_std_termios;
+ pty_driver->init_termios.c_iflag = 0;
+ pty_driver->init_termios.c_oflag = 0;
+ pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+ pty_driver->init_termios.c_lflag = 0;
+ pty_driver->init_termios.c_ispeed = 38400;
+ pty_driver->init_termios.c_ospeed = 38400;
+ pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW;
+ pty_driver->other = pty_slave_driver;
+ tty_set_operations(pty_driver, &master_pty_ops_bsd);
+
+ pty_slave_driver->owner = THIS_MODULE;
+ pty_slave_driver->driver_name = "pty_slave";
+ pty_slave_driver->name = "ttyp";
+ pty_slave_driver->major = PTY_SLAVE_MAJOR;
+ pty_slave_driver->minor_start = 0;
+ pty_slave_driver->type = TTY_DRIVER_TYPE_PTY;
+ pty_slave_driver->subtype = PTY_TYPE_SLAVE;
+ pty_slave_driver->init_termios = tty_std_termios;
+ pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+ pty_slave_driver->init_termios.c_ispeed = 38400;
+ pty_slave_driver->init_termios.c_ospeed = 38400;
+ pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS |
+ TTY_DRIVER_REAL_RAW;
+ pty_slave_driver->other = pty_driver;
+ tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
+
+ if (tty_register_driver(pty_driver))
+ panic("Couldn't register pty driver");
+ if (tty_register_driver(pty_slave_driver))
+ panic("Couldn't register pty slave driver");
+}
+#else
+static inline void legacy_pty_init(void) { }
+#endif
+
+/* Unix98 devices */
+#ifdef CONFIG_UNIX98_PTYS
+/*
+ * sysctl support for setting limits on the number of Unix98 ptys allocated.
+ * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
+ */
+int pty_limit = NR_UNIX98_PTY_DEFAULT;
+static int pty_limit_min;
+static int pty_limit_max = NR_UNIX98_PTY_MAX;
+static int pty_count;
+
+static struct cdev ptmx_cdev;
+
+static struct ctl_table pty_table[] = {
+ {
+ .procname = "max",
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .data = &pty_limit,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &pty_limit_min,
+ .extra2 = &pty_limit_max,
+ }, {
+ .procname = "nr",
+ .maxlen = sizeof(int),
+ .mode = 0444,
+ .data = &pty_count,
+ .proc_handler = proc_dointvec,
+ },
+ {}
+};
+
+static struct ctl_table pty_kern_table[] = {
+ {
+ .procname = "pty",
+ .mode = 0555,
+ .child = pty_table,
+ },
+ {}
+};
+
+static struct ctl_table pty_root_table[] = {
+ {
+ .procname = "kernel",
+ .mode = 0555,
+ .child = pty_kern_table,
+ },
+ {}
+};
+
+
+static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+ case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */
+ return pty_set_lock(tty, (int __user *)arg);
+ case TIOCGPTN: /* Get PT Number */
+ return put_user(tty->index, (unsigned int __user *)arg);
+ case TIOCSIG: /* Send signal to other side of pty */
+ return pty_signal(tty, (int) arg);
+ }
+
+ return -ENOIOCTLCMD;
+}
+
+/**
+ * ptm_unix98_lookup - find a pty master
+ * @driver: ptm driver
+ * @idx: tty index
+ *
+ * Look up a pty master device. Called under the tty_mutex for now.
+ * This provides our locking.
+ */
+
+static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
+ struct inode *ptm_inode, int idx)
+{
+ struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
+ if (tty)
+ tty = tty->link;
+ return tty;
+}
+
+/**
+ * pts_unix98_lookup - find a pty slave
+ * @driver: pts driver
+ * @idx: tty index
+ *
+ * Look up a pty master device. Called under the tty_mutex for now.
+ * This provides our locking.
+ */
+
+static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
+ struct inode *pts_inode, int idx)
+{
+ struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
+ /* Master must be open before slave */
+ if (!tty)
+ return ERR_PTR(-EIO);
+ return tty;
+}
+
+static void pty_unix98_shutdown(struct tty_struct *tty)
+{
+ /* We have our own method as we don't use the tty index */
+ kfree(tty->termios);
+}
+
+/* We have no need to install and remove our tty objects as devpts does all
+ the work for us */
+
+static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+ struct tty_struct *o_tty;
+ int idx = tty->index;
+
+ o_tty = alloc_tty_struct();
+ if (!o_tty)
+ return -ENOMEM;
+ if (!try_module_get(driver->other->owner)) {
+ /* This cannot in fact currently happen */
+ free_tty_struct(o_tty);
+ return -ENOMEM;
+ }
+ initialize_tty_struct(o_tty, driver->other, idx);
+
+ tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
+ if (tty->termios == NULL)
+ goto free_mem_out;
+ *tty->termios = driver->init_termios;
+ tty->termios_locked = tty->termios + 1;
+
+ o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
+ if (o_tty->termios == NULL)
+ goto free_mem_out;
+ *o_tty->termios = driver->other->init_termios;
+ o_tty->termios_locked = o_tty->termios + 1;
+
+ tty_driver_kref_get(driver->other);
+ if (driver->subtype == PTY_TYPE_MASTER)
+ o_tty->count++;
+ /* Establish the links in both directions */
+ tty->link = o_tty;
+ o_tty->link = tty;
+ /*
+ * All structures have been allocated, so now we install them.
+ * Failures after this point use release_tty to clean up, so
+ * there's no need to null out the local pointers.
+ */
+ tty_driver_kref_get(driver);
+ tty->count++;
+ pty_count++;
+ return 0;
+free_mem_out:
+ kfree(o_tty->termios);
+ module_put(o_tty->driver->owner);
+ free_tty_struct(o_tty);
+ kfree(tty->termios);
+ return -ENOMEM;
+}
+
+static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
+{
+ pty_count--;
+}
+
+static const struct tty_operations ptm_unix98_ops = {
+ .lookup = ptm_unix98_lookup,
+ .install = pty_unix98_install,
+ .remove = pty_unix98_remove,
+ .open = pty_open,
+ .close = pty_close,
+ .write = pty_write,
+ .write_room = pty_write_room,
+ .flush_buffer = pty_flush_buffer,
+ .chars_in_buffer = pty_chars_in_buffer,
+ .unthrottle = pty_unthrottle,
+ .set_termios = pty_set_termios,
+ .ioctl = pty_unix98_ioctl,
+ .shutdown = pty_unix98_shutdown,
+ .resize = pty_resize
+};
+
+static const struct tty_operations pty_unix98_ops = {
+ .lookup = pts_unix98_lookup,
+ .install = pty_unix98_install,
+ .remove = pty_unix98_remove,
+ .open = pty_open,
+ .close = pty_close,
+ .write = pty_write,
+ .write_room = pty_write_room,
+ .flush_buffer = pty_flush_buffer,
+ .chars_in_buffer = pty_chars_in_buffer,
+ .unthrottle = pty_unthrottle,
+ .set_termios = pty_set_termios,
+ .shutdown = pty_unix98_shutdown
+};
+
+/**
+ * ptmx_open - open a unix 98 pty master
+ * @inode: inode of device file
+ * @filp: file pointer to tty
+ *
+ * Allocate a unix98 pty master device from the ptmx driver.
+ *
+ * Locking: tty_mutex protects the init_dev work. tty->count should
+ * protect the rest.
+ * allocated_ptys_lock handles the list of free pty numbers
+ */
+
+static int ptmx_open(struct inode *inode, struct file *filp)
+{
+ struct tty_struct *tty;
+ int retval;
+ int index;
+
+ nonseekable_open(inode, filp);
+
+ /* find a device that is not in use. */
+ tty_lock();
+ index = devpts_new_index(inode);
+ tty_unlock();
+ if (index < 0)
+ return index;
+
+ mutex_lock(&tty_mutex);
+ tty_lock();
+ tty = tty_init_dev(ptm_driver, index, 1);
+ mutex_unlock(&tty_mutex);
+
+ if (IS_ERR(tty)) {
+ retval = PTR_ERR(tty);
+ goto out;
+ }
+
+ set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
+
+ retval = tty_add_file(tty, filp);
+ if (retval)
+ goto out;
+
+ retval = devpts_pty_new(inode, tty->link);
+ if (retval)
+ goto out1;
+
+ retval = ptm_driver->ops->open(tty, filp);
+ if (retval)
+ goto out2;
+out1:
+ tty_unlock();
+ return retval;
+out2:
+ tty_unlock();
+ tty_release(inode, filp);
+ return retval;
+out:
+ devpts_kill_index(inode, index);
+ tty_unlock();
+ return retval;
+}
+
+static struct file_operations ptmx_fops;
+
+static void __init unix98_pty_init(void)
+{
+ ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
+ if (!ptm_driver)
+ panic("Couldn't allocate Unix98 ptm driver");
+ pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX);
+ if (!pts_driver)
+ panic("Couldn't allocate Unix98 pts driver");
+
+ ptm_driver->owner = THIS_MODULE;
+ ptm_driver->driver_name = "pty_master";
+ ptm_driver->name = "ptm";
+ ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
+ ptm_driver->minor_start = 0;
+ ptm_driver->type = TTY_DRIVER_TYPE_PTY;
+ ptm_driver->subtype = PTY_TYPE_MASTER;
+ ptm_driver->init_termios = tty_std_termios;
+ ptm_driver->init_termios.c_iflag = 0;
+ ptm_driver->init_termios.c_oflag = 0;
+ ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+ ptm_driver->init_termios.c_lflag = 0;
+ ptm_driver->init_termios.c_ispeed = 38400;
+ ptm_driver->init_termios.c_ospeed = 38400;
+ ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
+ TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
+ ptm_driver->other = pts_driver;
+ tty_set_operations(ptm_driver, &ptm_unix98_ops);
+
+ pts_driver->owner = THIS_MODULE;
+ pts_driver->driver_name = "pty_slave";
+ pts_driver->name = "pts";
+ pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
+ pts_driver->minor_start = 0;
+ pts_driver->type = TTY_DRIVER_TYPE_PTY;
+ pts_driver->subtype = PTY_TYPE_SLAVE;
+ pts_driver->init_termios = tty_std_termios;
+ pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
+ pts_driver->init_termios.c_ispeed = 38400;
+ pts_driver->init_termios.c_ospeed = 38400;
+ pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
+ TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM;
+ pts_driver->other = ptm_driver;
+ tty_set_operations(pts_driver, &pty_unix98_ops);
+
+ if (tty_register_driver(ptm_driver))
+ panic("Couldn't register Unix98 ptm driver");
+ if (tty_register_driver(pts_driver))
+ panic("Couldn't register Unix98 pts driver");
+
+ register_sysctl_table(pty_root_table);
+
+ /* Now create the /dev/ptmx special device */
+ tty_default_fops(&ptmx_fops);
+ ptmx_fops.open = ptmx_open;
+
+ cdev_init(&ptmx_cdev, &ptmx_fops);
+ if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
+ register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
+ panic("Couldn't register /dev/ptmx driver\n");
+ device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
+}
+
+#else
+static inline void unix98_pty_init(void) { }
+#endif
+
+static int __init pty_init(void)
+{
+ legacy_pty_init();
+ unix98_pty_init();
+ return 0;
+}
+module_init(pty_init);
--- /dev/null
+/*
+ * Linux Magic System Request Key Hacks
+ *
+ * (c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ * based on ideas by Pavel Machek <pavel@atrey.karlin.mff.cuni.cz>
+ *
+ * (c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
+ * overhauled to use key registration
+ * based upon discusions in irc://irc.openprojects.net/#kernelnewbies
+ *
+ * Copyright (c) 2010 Dmitry Torokhov
+ * Input handler conversion
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/kdev_t.h>
+#include <linux/major.h>
+#include <linux/reboot.h>
+#include <linux/sysrq.h>
+#include <linux/kbd_kern.h>
+#include <linux/proc_fs.h>
+#include <linux/nmi.h>
+#include <linux/quotaops.h>
+#include <linux/perf_event.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/suspend.h>
+#include <linux/writeback.h>
+#include <linux/buffer_head.h> /* for fsync_bdev() */
+#include <linux/swap.h>
+#include <linux/spinlock.h>
+#include <linux/vt_kern.h>
+#include <linux/workqueue.h>
+#include <linux/hrtimer.h>
+#include <linux/oom.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+
+#include <asm/ptrace.h>
+#include <asm/irq_regs.h>
+
+/* Whether we react on sysrq keys or just ignore them */
+static int __read_mostly sysrq_enabled = 1;
+static bool __read_mostly sysrq_always_enabled;
+
+static bool sysrq_on(void)
+{
+ return sysrq_enabled || sysrq_always_enabled;
+}
+
+/*
+ * A value of 1 means 'all', other nonzero values are an op mask:
+ */
+static bool sysrq_on_mask(int mask)
+{
+ return sysrq_always_enabled ||
+ sysrq_enabled == 1 ||
+ (sysrq_enabled & mask);
+}
+
+static int __init sysrq_always_enabled_setup(char *str)
+{
+ sysrq_always_enabled = true;
+ pr_info("sysrq always enabled.\n");
+
+ return 1;
+}
+
+__setup("sysrq_always_enabled", sysrq_always_enabled_setup);
+
+
+static void sysrq_handle_loglevel(int key)
+{
+ int i;
+
+ i = key - '0';
+ console_loglevel = 7;
+ printk("Loglevel set to %d\n", i);
+ console_loglevel = i;
+}
+static struct sysrq_key_op sysrq_loglevel_op = {
+ .handler = sysrq_handle_loglevel,
+ .help_msg = "loglevel(0-9)",
+ .action_msg = "Changing Loglevel",
+ .enable_mask = SYSRQ_ENABLE_LOG,
+};
+
+#ifdef CONFIG_VT
+static void sysrq_handle_SAK(int key)
+{
+ struct work_struct *SAK_work = &vc_cons[fg_console].SAK_work;
+ schedule_work(SAK_work);
+}
+static struct sysrq_key_op sysrq_SAK_op = {
+ .handler = sysrq_handle_SAK,
+ .help_msg = "saK",
+ .action_msg = "SAK",
+ .enable_mask = SYSRQ_ENABLE_KEYBOARD,
+};
+#else
+#define sysrq_SAK_op (*(struct sysrq_key_op *)NULL)
+#endif
+
+#ifdef CONFIG_VT
+static void sysrq_handle_unraw(int key)
+{
+ struct kbd_struct *kbd = &kbd_table[fg_console];
+
+ if (kbd)
+ kbd->kbdmode = default_utf8 ? VC_UNICODE : VC_XLATE;
+}
+static struct sysrq_key_op sysrq_unraw_op = {
+ .handler = sysrq_handle_unraw,
+ .help_msg = "unRaw",
+ .action_msg = "Keyboard mode set to system default",
+ .enable_mask = SYSRQ_ENABLE_KEYBOARD,
+};
+#else
+#define sysrq_unraw_op (*(struct sysrq_key_op *)NULL)
+#endif /* CONFIG_VT */
+
+static void sysrq_handle_crash(int key)
+{
+ char *killer = NULL;
+
+ panic_on_oops = 1; /* force panic */
+ wmb();
+ *killer = 1;
+}
+static struct sysrq_key_op sysrq_crash_op = {
+ .handler = sysrq_handle_crash,
+ .help_msg = "Crash",
+ .action_msg = "Trigger a crash",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+
+static void sysrq_handle_reboot(int key)
+{
+ lockdep_off();
+ local_irq_enable();
+ emergency_restart();
+}
+static struct sysrq_key_op sysrq_reboot_op = {
+ .handler = sysrq_handle_reboot,
+ .help_msg = "reBoot",
+ .action_msg = "Resetting",
+ .enable_mask = SYSRQ_ENABLE_BOOT,
+};
+
+static void sysrq_handle_sync(int key)
+{
+ emergency_sync();
+}
+static struct sysrq_key_op sysrq_sync_op = {
+ .handler = sysrq_handle_sync,
+ .help_msg = "Sync",
+ .action_msg = "Emergency Sync",
+ .enable_mask = SYSRQ_ENABLE_SYNC,
+};
+
+static void sysrq_handle_show_timers(int key)
+{
+ sysrq_timer_list_show();
+}
+
+static struct sysrq_key_op sysrq_show_timers_op = {
+ .handler = sysrq_handle_show_timers,
+ .help_msg = "show-all-timers(Q)",
+ .action_msg = "Show clockevent devices & pending hrtimers (no others)",
+};
+
+static void sysrq_handle_mountro(int key)
+{
+ emergency_remount();
+}
+static struct sysrq_key_op sysrq_mountro_op = {
+ .handler = sysrq_handle_mountro,
+ .help_msg = "Unmount",
+ .action_msg = "Emergency Remount R/O",
+ .enable_mask = SYSRQ_ENABLE_REMOUNT,
+};
+
+#ifdef CONFIG_LOCKDEP
+static void sysrq_handle_showlocks(int key)
+{
+ debug_show_all_locks();
+}
+
+static struct sysrq_key_op sysrq_showlocks_op = {
+ .handler = sysrq_handle_showlocks,
+ .help_msg = "show-all-locks(D)",
+ .action_msg = "Show Locks Held",
+};
+#else
+#define sysrq_showlocks_op (*(struct sysrq_key_op *)NULL)
+#endif
+
+#ifdef CONFIG_SMP
+static DEFINE_SPINLOCK(show_lock);
+
+static void showacpu(void *dummy)
+{
+ unsigned long flags;
+
+ /* Idle CPUs have no interesting backtrace. */
+ if (idle_cpu(smp_processor_id()))
+ return;
+
+ spin_lock_irqsave(&show_lock, flags);
+ printk(KERN_INFO "CPU%d:\n", smp_processor_id());
+ show_stack(NULL, NULL);
+ spin_unlock_irqrestore(&show_lock, flags);
+}
+
+static void sysrq_showregs_othercpus(struct work_struct *dummy)
+{
+ smp_call_function(showacpu, NULL, 0);
+}
+
+static DECLARE_WORK(sysrq_showallcpus, sysrq_showregs_othercpus);
+
+static void sysrq_handle_showallcpus(int key)
+{
+ /*
+ * Fall back to the workqueue based printing if the
+ * backtrace printing did not succeed or the
+ * architecture has no support for it:
+ */
+ if (!trigger_all_cpu_backtrace()) {
+ struct pt_regs *regs = get_irq_regs();
+
+ if (regs) {
+ printk(KERN_INFO "CPU%d:\n", smp_processor_id());
+ show_regs(regs);
+ }
+ schedule_work(&sysrq_showallcpus);
+ }
+}
+
+static struct sysrq_key_op sysrq_showallcpus_op = {
+ .handler = sysrq_handle_showallcpus,
+ .help_msg = "show-backtrace-all-active-cpus(L)",
+ .action_msg = "Show backtrace of all active CPUs",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+#endif
+
+static void sysrq_handle_showregs(int key)
+{
+ struct pt_regs *regs = get_irq_regs();
+ if (regs)
+ show_regs(regs);
+ perf_event_print_debug();
+}
+static struct sysrq_key_op sysrq_showregs_op = {
+ .handler = sysrq_handle_showregs,
+ .help_msg = "show-registers(P)",
+ .action_msg = "Show Regs",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+
+static void sysrq_handle_showstate(int key)
+{
+ show_state();
+}
+static struct sysrq_key_op sysrq_showstate_op = {
+ .handler = sysrq_handle_showstate,
+ .help_msg = "show-task-states(T)",
+ .action_msg = "Show State",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+
+static void sysrq_handle_showstate_blocked(int key)
+{
+ show_state_filter(TASK_UNINTERRUPTIBLE);
+}
+static struct sysrq_key_op sysrq_showstate_blocked_op = {
+ .handler = sysrq_handle_showstate_blocked,
+ .help_msg = "show-blocked-tasks(W)",
+ .action_msg = "Show Blocked State",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+
+#ifdef CONFIG_TRACING
+#include <linux/ftrace.h>
+
+static void sysrq_ftrace_dump(int key)
+{
+ ftrace_dump(DUMP_ALL);
+}
+static struct sysrq_key_op sysrq_ftrace_dump_op = {
+ .handler = sysrq_ftrace_dump,
+ .help_msg = "dump-ftrace-buffer(Z)",
+ .action_msg = "Dump ftrace buffer",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+#else
+#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)NULL)
+#endif
+
+static void sysrq_handle_showmem(int key)
+{
+ show_mem();
+}
+static struct sysrq_key_op sysrq_showmem_op = {
+ .handler = sysrq_handle_showmem,
+ .help_msg = "show-memory-usage(M)",
+ .action_msg = "Show Memory",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+
+/*
+ * Signal sysrq helper function. Sends a signal to all user processes.
+ */
+static void send_sig_all(int sig)
+{
+ struct task_struct *p;
+
+ for_each_process(p) {
+ if (p->mm && !is_global_init(p))
+ /* Not swapper, init nor kernel thread */
+ force_sig(sig, p);
+ }
+}
+
+static void sysrq_handle_term(int key)
+{
+ send_sig_all(SIGTERM);
+ console_loglevel = 8;
+}
+static struct sysrq_key_op sysrq_term_op = {
+ .handler = sysrq_handle_term,
+ .help_msg = "terminate-all-tasks(E)",
+ .action_msg = "Terminate All Tasks",
+ .enable_mask = SYSRQ_ENABLE_SIGNAL,
+};
+
+static void moom_callback(struct work_struct *ignored)
+{
+ out_of_memory(node_zonelist(0, GFP_KERNEL), GFP_KERNEL, 0, NULL);
+}
+
+static DECLARE_WORK(moom_work, moom_callback);
+
+static void sysrq_handle_moom(int key)
+{
+ schedule_work(&moom_work);
+}
+static struct sysrq_key_op sysrq_moom_op = {
+ .handler = sysrq_handle_moom,
+ .help_msg = "memory-full-oom-kill(F)",
+ .action_msg = "Manual OOM execution",
+ .enable_mask = SYSRQ_ENABLE_SIGNAL,
+};
+
+#ifdef CONFIG_BLOCK
+static void sysrq_handle_thaw(int key)
+{
+ emergency_thaw_all();
+}
+static struct sysrq_key_op sysrq_thaw_op = {
+ .handler = sysrq_handle_thaw,
+ .help_msg = "thaw-filesystems(J)",
+ .action_msg = "Emergency Thaw of all frozen filesystems",
+ .enable_mask = SYSRQ_ENABLE_SIGNAL,
+};
+#endif
+
+static void sysrq_handle_kill(int key)
+{
+ send_sig_all(SIGKILL);
+ console_loglevel = 8;
+}
+static struct sysrq_key_op sysrq_kill_op = {
+ .handler = sysrq_handle_kill,
+ .help_msg = "kill-all-tasks(I)",
+ .action_msg = "Kill All Tasks",
+ .enable_mask = SYSRQ_ENABLE_SIGNAL,
+};
+
+static void sysrq_handle_unrt(int key)
+{
+ normalize_rt_tasks();
+}
+static struct sysrq_key_op sysrq_unrt_op = {
+ .handler = sysrq_handle_unrt,
+ .help_msg = "nice-all-RT-tasks(N)",
+ .action_msg = "Nice All RT Tasks",
+ .enable_mask = SYSRQ_ENABLE_RTNICE,
+};
+
+/* Key Operations table and lock */
+static DEFINE_SPINLOCK(sysrq_key_table_lock);
+
+static struct sysrq_key_op *sysrq_key_table[36] = {
+ &sysrq_loglevel_op, /* 0 */
+ &sysrq_loglevel_op, /* 1 */
+ &sysrq_loglevel_op, /* 2 */
+ &sysrq_loglevel_op, /* 3 */
+ &sysrq_loglevel_op, /* 4 */
+ &sysrq_loglevel_op, /* 5 */
+ &sysrq_loglevel_op, /* 6 */
+ &sysrq_loglevel_op, /* 7 */
+ &sysrq_loglevel_op, /* 8 */
+ &sysrq_loglevel_op, /* 9 */
+
+ /*
+ * a: Don't use for system provided sysrqs, it is handled specially on
+ * sparc and will never arrive.
+ */
+ NULL, /* a */
+ &sysrq_reboot_op, /* b */
+ &sysrq_crash_op, /* c & ibm_emac driver debug */
+ &sysrq_showlocks_op, /* d */
+ &sysrq_term_op, /* e */
+ &sysrq_moom_op, /* f */
+ /* g: May be registered for the kernel debugger */
+ NULL, /* g */
+ NULL, /* h - reserved for help */
+ &sysrq_kill_op, /* i */
+#ifdef CONFIG_BLOCK
+ &sysrq_thaw_op, /* j */
+#else
+ NULL, /* j */
+#endif
+ &sysrq_SAK_op, /* k */
+#ifdef CONFIG_SMP
+ &sysrq_showallcpus_op, /* l */
+#else
+ NULL, /* l */
+#endif
+ &sysrq_showmem_op, /* m */
+ &sysrq_unrt_op, /* n */
+ /* o: This will often be registered as 'Off' at init time */
+ NULL, /* o */
+ &sysrq_showregs_op, /* p */
+ &sysrq_show_timers_op, /* q */
+ &sysrq_unraw_op, /* r */
+ &sysrq_sync_op, /* s */
+ &sysrq_showstate_op, /* t */
+ &sysrq_mountro_op, /* u */
+ /* v: May be registered for frame buffer console restore */
+ NULL, /* v */
+ &sysrq_showstate_blocked_op, /* w */
+ /* x: May be registered on ppc/powerpc for xmon */
+ NULL, /* x */
+ /* y: May be registered on sparc64 for global register dump */
+ NULL, /* y */
+ &sysrq_ftrace_dump_op, /* z */
+};
+
+/* key2index calculation, -1 on invalid index */
+static int sysrq_key_table_key2index(int key)
+{
+ int retval;
+
+ if ((key >= '0') && (key <= '9'))
+ retval = key - '0';
+ else if ((key >= 'a') && (key <= 'z'))
+ retval = key + 10 - 'a';
+ else
+ retval = -1;
+ return retval;
+}
+
+/*
+ * get and put functions for the table, exposed to modules.
+ */
+struct sysrq_key_op *__sysrq_get_key_op(int key)
+{
+ struct sysrq_key_op *op_p = NULL;
+ int i;
+
+ i = sysrq_key_table_key2index(key);
+ if (i != -1)
+ op_p = sysrq_key_table[i];
+
+ return op_p;
+}
+
+static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
+{
+ int i = sysrq_key_table_key2index(key);
+
+ if (i != -1)
+ sysrq_key_table[i] = op_p;
+}
+
+void __handle_sysrq(int key, bool check_mask)
+{
+ struct sysrq_key_op *op_p;
+ int orig_log_level;
+ int i;
+ unsigned long flags;
+
+ spin_lock_irqsave(&sysrq_key_table_lock, flags);
+ /*
+ * Raise the apparent loglevel to maximum so that the sysrq header
+ * is shown to provide the user with positive feedback. We do not
+ * simply emit this at KERN_EMERG as that would change message
+ * routing in the consumers of /proc/kmsg.
+ */
+ orig_log_level = console_loglevel;
+ console_loglevel = 7;
+ printk(KERN_INFO "SysRq : ");
+
+ op_p = __sysrq_get_key_op(key);
+ if (op_p) {
+ /*
+ * Should we check for enabled operations (/proc/sysrq-trigger
+ * should not) and is the invoked operation enabled?
+ */
+ if (!check_mask || sysrq_on_mask(op_p->enable_mask)) {
+ printk("%s\n", op_p->action_msg);
+ console_loglevel = orig_log_level;
+ op_p->handler(key);
+ } else {
+ printk("This sysrq operation is disabled.\n");
+ }
+ } else {
+ printk("HELP : ");
+ /* Only print the help msg once per handler */
+ for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
+ if (sysrq_key_table[i]) {
+ int j;
+
+ for (j = 0; sysrq_key_table[i] !=
+ sysrq_key_table[j]; j++)
+ ;
+ if (j != i)
+ continue;
+ printk("%s ", sysrq_key_table[i]->help_msg);
+ }
+ }
+ printk("\n");
+ console_loglevel = orig_log_level;
+ }
+ spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
+}
+
+void handle_sysrq(int key)
+{
+ if (sysrq_on())
+ __handle_sysrq(key, true);
+}
+EXPORT_SYMBOL(handle_sysrq);
+
+#ifdef CONFIG_INPUT
+
+/* Simple translation table for the SysRq keys */
+static const unsigned char sysrq_xlate[KEY_MAX + 1] =
+ "\000\0331234567890-=\177\t" /* 0x00 - 0x0f */
+ "qwertyuiop[]\r\000as" /* 0x10 - 0x1f */
+ "dfghjkl;'`\000\\zxcv" /* 0x20 - 0x2f */
+ "bnm,./\000*\000 \000\201\202\203\204\205" /* 0x30 - 0x3f */
+ "\206\207\210\211\212\000\000789-456+1" /* 0x40 - 0x4f */
+ "230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */
+ "\r\000/"; /* 0x60 - 0x6f */
+
+static bool sysrq_down;
+static int sysrq_alt_use;
+static int sysrq_alt;
+static DEFINE_SPINLOCK(sysrq_event_lock);
+
+static bool sysrq_filter(struct input_handle *handle, unsigned int type,
+ unsigned int code, int value)
+{
+ bool suppress;
+
+ /* We are called with interrupts disabled, just take the lock */
+ spin_lock(&sysrq_event_lock);
+
+ if (type != EV_KEY)
+ goto out;
+
+ switch (code) {
+
+ case KEY_LEFTALT:
+ case KEY_RIGHTALT:
+ if (value)
+ sysrq_alt = code;
+ else {
+ if (sysrq_down && code == sysrq_alt_use)
+ sysrq_down = false;
+
+ sysrq_alt = 0;
+ }
+ break;
+
+ case KEY_SYSRQ:
+ if (value == 1 && sysrq_alt) {
+ sysrq_down = true;
+ sysrq_alt_use = sysrq_alt;
+ }
+ break;
+
+ default:
+ if (sysrq_down && value && value != 2)
+ __handle_sysrq(sysrq_xlate[code], true);
+ break;
+ }
+
+out:
+ suppress = sysrq_down;
+ spin_unlock(&sysrq_event_lock);
+
+ return suppress;
+}
+
+static int sysrq_connect(struct input_handler *handler,
+ struct input_dev *dev,
+ const struct input_device_id *id)
+{
+ struct input_handle *handle;
+ int error;
+
+ sysrq_down = false;
+ sysrq_alt = 0;
+
+ handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
+ if (!handle)
+ return -ENOMEM;
+
+ handle->dev = dev;
+ handle->handler = handler;
+ handle->name = "sysrq";
+
+ error = input_register_handle(handle);
+ if (error) {
+ pr_err("Failed to register input sysrq handler, error %d\n",
+ error);
+ goto err_free;
+ }
+
+ error = input_open_device(handle);
+ if (error) {
+ pr_err("Failed to open input device, error %d\n", error);
+ goto err_unregister;
+ }
+
+ return 0;
+
+ err_unregister:
+ input_unregister_handle(handle);
+ err_free:
+ kfree(handle);
+ return error;
+}
+
+static void sysrq_disconnect(struct input_handle *handle)
+{
+ input_close_device(handle);
+ input_unregister_handle(handle);
+ kfree(handle);
+}
+
+/*
+ * We are matching on KEY_LEFTALT instead of KEY_SYSRQ because not all
+ * keyboards have SysRq key predefined and so user may add it to keymap
+ * later, but we expect all such keyboards to have left alt.
+ */
+static const struct input_device_id sysrq_ids[] = {
+ {
+ .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
+ INPUT_DEVICE_ID_MATCH_KEYBIT,
+ .evbit = { BIT_MASK(EV_KEY) },
+ .keybit = { BIT_MASK(KEY_LEFTALT) },
+ },
+ { },
+};
+
+static struct input_handler sysrq_handler = {
+ .filter = sysrq_filter,
+ .connect = sysrq_connect,
+ .disconnect = sysrq_disconnect,
+ .name = "sysrq",
+ .id_table = sysrq_ids,
+};
+
+static bool sysrq_handler_registered;
+
+static inline void sysrq_register_handler(void)
+{
+ int error;
+
+ error = input_register_handler(&sysrq_handler);
+ if (error)
+ pr_err("Failed to register input handler, error %d", error);
+ else
+ sysrq_handler_registered = true;
+}
+
+static inline void sysrq_unregister_handler(void)
+{
+ if (sysrq_handler_registered) {
+ input_unregister_handler(&sysrq_handler);
+ sysrq_handler_registered = false;
+ }
+}
+
+#else
+
+static inline void sysrq_register_handler(void)
+{
+}
+
+static inline void sysrq_unregister_handler(void)
+{
+}
+
+#endif /* CONFIG_INPUT */
+
+int sysrq_toggle_support(int enable_mask)
+{
+ bool was_enabled = sysrq_on();
+
+ sysrq_enabled = enable_mask;
+
+ if (was_enabled != sysrq_on()) {
+ if (sysrq_on())
+ sysrq_register_handler();
+ else
+ sysrq_unregister_handler();
+ }
+
+ return 0;
+}
+
+static int __sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
+ struct sysrq_key_op *remove_op_p)
+{
+ int retval;
+ unsigned long flags;
+
+ spin_lock_irqsave(&sysrq_key_table_lock, flags);
+ if (__sysrq_get_key_op(key) == remove_op_p) {
+ __sysrq_put_key_op(key, insert_op_p);
+ retval = 0;
+ } else {
+ retval = -1;
+ }
+ spin_unlock_irqrestore(&sysrq_key_table_lock, flags);
+ return retval;
+}
+
+int register_sysrq_key(int key, struct sysrq_key_op *op_p)
+{
+ return __sysrq_swap_key_ops(key, op_p, NULL);
+}
+EXPORT_SYMBOL(register_sysrq_key);
+
+int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
+{
+ return __sysrq_swap_key_ops(key, NULL, op_p);
+}
+EXPORT_SYMBOL(unregister_sysrq_key);
+
+#ifdef CONFIG_PROC_FS
+/*
+ * writing 'C' to /proc/sysrq-trigger is like sysrq-C
+ */
+static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ if (count) {
+ char c;
+
+ if (get_user(c, buf))
+ return -EFAULT;
+ __handle_sysrq(c, false);
+ }
+
+ return count;
+}
+
+static const struct file_operations proc_sysrq_trigger_operations = {
+ .write = write_sysrq_trigger,
+ .llseek = noop_llseek,
+};
+
+static void sysrq_init_procfs(void)
+{
+ if (!proc_create("sysrq-trigger", S_IWUSR, NULL,
+ &proc_sysrq_trigger_operations))
+ pr_err("Failed to register proc interface\n");
+}
+
+#else
+
+static inline void sysrq_init_procfs(void)
+{
+}
+
+#endif /* CONFIG_PROC_FS */
+
+static int __init sysrq_init(void)
+{
+ sysrq_init_procfs();
+
+ if (sysrq_on())
+ sysrq_register_handler();
+
+ return 0;
+}
+module_init(sysrq_init);
--- /dev/null
+/*
+ * Creating audit events from TTY input.
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All rights reserved. This copyrighted
+ * material is made available to anyone wishing to use, modify, copy, or
+ * redistribute it subject to the terms and conditions of the GNU General
+ * Public License v.2.
+ *
+ * Authors: Miloslav Trmac <mitr@redhat.com>
+ */
+
+#include <linux/audit.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+
+struct tty_audit_buf {
+ atomic_t count;
+ struct mutex mutex; /* Protects all data below */
+ int major, minor; /* The TTY which the data is from */
+ unsigned icanon:1;
+ size_t valid;
+ unsigned char *data; /* Allocated size N_TTY_BUF_SIZE */
+};
+
+static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor,
+ int icanon)
+{
+ struct tty_audit_buf *buf;
+
+ buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ goto err;
+ buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
+ if (!buf->data)
+ goto err_buf;
+ atomic_set(&buf->count, 1);
+ mutex_init(&buf->mutex);
+ buf->major = major;
+ buf->minor = minor;
+ buf->icanon = icanon;
+ buf->valid = 0;
+ return buf;
+
+err_buf:
+ kfree(buf);
+err:
+ return NULL;
+}
+
+static void tty_audit_buf_free(struct tty_audit_buf *buf)
+{
+ WARN_ON(buf->valid != 0);
+ kfree(buf->data);
+ kfree(buf);
+}
+
+static void tty_audit_buf_put(struct tty_audit_buf *buf)
+{
+ if (atomic_dec_and_test(&buf->count))
+ tty_audit_buf_free(buf);
+}
+
+static void tty_audit_log(const char *description, struct task_struct *tsk,
+ uid_t loginuid, unsigned sessionid, int major,
+ int minor, unsigned char *data, size_t size)
+{
+ struct audit_buffer *ab;
+
+ ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_TTY);
+ if (ab) {
+ char name[sizeof(tsk->comm)];
+ uid_t uid = task_uid(tsk);
+
+ audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u "
+ "major=%d minor=%d comm=", description,
+ tsk->pid, uid, loginuid, sessionid,
+ major, minor);
+ get_task_comm(name, tsk);
+ audit_log_untrustedstring(ab, name);
+ audit_log_format(ab, " data=");
+ audit_log_n_hex(ab, data, size);
+ audit_log_end(ab);
+ }
+}
+
+/**
+ * tty_audit_buf_push - Push buffered data out
+ *
+ * Generate an audit message from the contents of @buf, which is owned by
+ * @tsk with @loginuid. @buf->mutex must be locked.
+ */
+static void tty_audit_buf_push(struct task_struct *tsk, uid_t loginuid,
+ unsigned int sessionid,
+ struct tty_audit_buf *buf)
+{
+ if (buf->valid == 0)
+ return;
+ if (audit_enabled == 0)
+ return;
+ tty_audit_log("tty", tsk, loginuid, sessionid, buf->major, buf->minor,
+ buf->data, buf->valid);
+ buf->valid = 0;
+}
+
+/**
+ * tty_audit_buf_push_current - Push buffered data out
+ *
+ * Generate an audit message from the contents of @buf, which is owned by
+ * the current task. @buf->mutex must be locked.
+ */
+static void tty_audit_buf_push_current(struct tty_audit_buf *buf)
+{
+ uid_t auid = audit_get_loginuid(current);
+ unsigned int sessionid = audit_get_sessionid(current);
+ tty_audit_buf_push(current, auid, sessionid, buf);
+}
+
+/**
+ * tty_audit_exit - Handle a task exit
+ *
+ * Make sure all buffered data is written out and deallocate the buffer.
+ * Only needs to be called if current->signal->tty_audit_buf != %NULL.
+ */
+void tty_audit_exit(void)
+{
+ struct tty_audit_buf *buf;
+
+ spin_lock_irq(¤t->sighand->siglock);
+ buf = current->signal->tty_audit_buf;
+ current->signal->tty_audit_buf = NULL;
+ spin_unlock_irq(¤t->sighand->siglock);
+ if (!buf)
+ return;
+
+ mutex_lock(&buf->mutex);
+ tty_audit_buf_push_current(buf);
+ mutex_unlock(&buf->mutex);
+
+ tty_audit_buf_put(buf);
+}
+
+/**
+ * tty_audit_fork - Copy TTY audit state for a new task
+ *
+ * Set up TTY audit state in @sig from current. @sig needs no locking.
+ */
+void tty_audit_fork(struct signal_struct *sig)
+{
+ spin_lock_irq(¤t->sighand->siglock);
+ sig->audit_tty = current->signal->audit_tty;
+ spin_unlock_irq(¤t->sighand->siglock);
+}
+
+/**
+ * tty_audit_tiocsti - Log TIOCSTI
+ */
+void tty_audit_tiocsti(struct tty_struct *tty, char ch)
+{
+ struct tty_audit_buf *buf;
+ int major, minor, should_audit;
+
+ spin_lock_irq(¤t->sighand->siglock);
+ should_audit = current->signal->audit_tty;
+ buf = current->signal->tty_audit_buf;
+ if (buf)
+ atomic_inc(&buf->count);
+ spin_unlock_irq(¤t->sighand->siglock);
+
+ major = tty->driver->major;
+ minor = tty->driver->minor_start + tty->index;
+ if (buf) {
+ mutex_lock(&buf->mutex);
+ if (buf->major == major && buf->minor == minor)
+ tty_audit_buf_push_current(buf);
+ mutex_unlock(&buf->mutex);
+ tty_audit_buf_put(buf);
+ }
+
+ if (should_audit && audit_enabled) {
+ uid_t auid;
+ unsigned int sessionid;
+
+ auid = audit_get_loginuid(current);
+ sessionid = audit_get_sessionid(current);
+ tty_audit_log("ioctl=TIOCSTI", current, auid, sessionid, major,
+ minor, &ch, 1);
+ }
+}
+
+/**
+ * tty_audit_push_task - Flush task's pending audit data
+ * @tsk: task pointer
+ * @loginuid: sender login uid
+ * @sessionid: sender session id
+ *
+ * Called with a ref on @tsk held. Try to lock sighand and get a
+ * reference to the tty audit buffer if available.
+ * Flush the buffer or return an appropriate error code.
+ */
+int tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
+{
+ struct tty_audit_buf *buf = ERR_PTR(-EPERM);
+ unsigned long flags;
+
+ if (!lock_task_sighand(tsk, &flags))
+ return -ESRCH;
+
+ if (tsk->signal->audit_tty) {
+ buf = tsk->signal->tty_audit_buf;
+ if (buf)
+ atomic_inc(&buf->count);
+ }
+ unlock_task_sighand(tsk, &flags);
+
+ /*
+ * Return 0 when signal->audit_tty set
+ * but tsk->signal->tty_audit_buf == NULL.
+ */
+ if (!buf || IS_ERR(buf))
+ return PTR_ERR(buf);
+
+ mutex_lock(&buf->mutex);
+ tty_audit_buf_push(tsk, loginuid, sessionid, buf);
+ mutex_unlock(&buf->mutex);
+
+ tty_audit_buf_put(buf);
+ return 0;
+}
+
+/**
+ * tty_audit_buf_get - Get an audit buffer.
+ *
+ * Get an audit buffer for @tty, allocate it if necessary. Return %NULL
+ * if TTY auditing is disabled or out of memory. Otherwise, return a new
+ * reference to the buffer.
+ */
+static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty)
+{
+ struct tty_audit_buf *buf, *buf2;
+
+ buf = NULL;
+ buf2 = NULL;
+ spin_lock_irq(¤t->sighand->siglock);
+ if (likely(!current->signal->audit_tty))
+ goto out;
+ buf = current->signal->tty_audit_buf;
+ if (buf) {
+ atomic_inc(&buf->count);
+ goto out;
+ }
+ spin_unlock_irq(¤t->sighand->siglock);
+
+ buf2 = tty_audit_buf_alloc(tty->driver->major,
+ tty->driver->minor_start + tty->index,
+ tty->icanon);
+ if (buf2 == NULL) {
+ audit_log_lost("out of memory in TTY auditing");
+ return NULL;
+ }
+
+ spin_lock_irq(¤t->sighand->siglock);
+ if (!current->signal->audit_tty)
+ goto out;
+ buf = current->signal->tty_audit_buf;
+ if (!buf) {
+ current->signal->tty_audit_buf = buf2;
+ buf = buf2;
+ buf2 = NULL;
+ }
+ atomic_inc(&buf->count);
+ /* Fall through */
+ out:
+ spin_unlock_irq(¤t->sighand->siglock);
+ if (buf2)
+ tty_audit_buf_free(buf2);
+ return buf;
+}
+
+/**
+ * tty_audit_add_data - Add data for TTY auditing.
+ *
+ * Audit @data of @size from @tty, if necessary.
+ */
+void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
+ size_t size)
+{
+ struct tty_audit_buf *buf;
+ int major, minor;
+
+ if (unlikely(size == 0))
+ return;
+
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY
+ && tty->driver->subtype == PTY_TYPE_MASTER)
+ return;
+
+ buf = tty_audit_buf_get(tty);
+ if (!buf)
+ return;
+
+ mutex_lock(&buf->mutex);
+ major = tty->driver->major;
+ minor = tty->driver->minor_start + tty->index;
+ if (buf->major != major || buf->minor != minor
+ || buf->icanon != tty->icanon) {
+ tty_audit_buf_push_current(buf);
+ buf->major = major;
+ buf->minor = minor;
+ buf->icanon = tty->icanon;
+ }
+ do {
+ size_t run;
+
+ run = N_TTY_BUF_SIZE - buf->valid;
+ if (run > size)
+ run = size;
+ memcpy(buf->data + buf->valid, data, run);
+ buf->valid += run;
+ data += run;
+ size -= run;
+ if (buf->valid == N_TTY_BUF_SIZE)
+ tty_audit_buf_push_current(buf);
+ } while (size != 0);
+ mutex_unlock(&buf->mutex);
+ tty_audit_buf_put(buf);
+}
+
+/**
+ * tty_audit_push - Push buffered data out
+ *
+ * Make sure no audit data is pending for @tty on the current process.
+ */
+void tty_audit_push(struct tty_struct *tty)
+{
+ struct tty_audit_buf *buf;
+
+ spin_lock_irq(¤t->sighand->siglock);
+ if (likely(!current->signal->audit_tty)) {
+ spin_unlock_irq(¤t->sighand->siglock);
+ return;
+ }
+ buf = current->signal->tty_audit_buf;
+ if (buf)
+ atomic_inc(&buf->count);
+ spin_unlock_irq(¤t->sighand->siglock);
+
+ if (buf) {
+ int major, minor;
+
+ major = tty->driver->major;
+ minor = tty->driver->minor_start + tty->index;
+ mutex_lock(&buf->mutex);
+ if (buf->major == major && buf->minor == minor)
+ tty_audit_buf_push_current(buf);
+ mutex_unlock(&buf->mutex);
+ tty_audit_buf_put(buf);
+ }
+}
--- /dev/null
+/*
+ * Tty buffer allocation management
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+/**
+ * tty_buffer_free_all - free buffers used by a tty
+ * @tty: tty to free from
+ *
+ * Remove all the buffers pending on a tty whether queued with data
+ * or in the free ring. Must be called when the tty is no longer in use
+ *
+ * Locking: none
+ */
+
+void tty_buffer_free_all(struct tty_struct *tty)
+{
+ struct tty_buffer *thead;
+ while ((thead = tty->buf.head) != NULL) {
+ tty->buf.head = thead->next;
+ kfree(thead);
+ }
+ while ((thead = tty->buf.free) != NULL) {
+ tty->buf.free = thead->next;
+ kfree(thead);
+ }
+ tty->buf.tail = NULL;
+ tty->buf.memory_used = 0;
+}
+
+/**
+ * tty_buffer_alloc - allocate a tty buffer
+ * @tty: tty device
+ * @size: desired size (characters)
+ *
+ * Allocate a new tty buffer to hold the desired number of characters.
+ * Return NULL if out of memory or the allocation would exceed the
+ * per device queue
+ *
+ * Locking: Caller must hold tty->buf.lock
+ */
+
+static struct tty_buffer *tty_buffer_alloc(struct tty_struct *tty, size_t size)
+{
+ struct tty_buffer *p;
+
+ if (tty->buf.memory_used + size > 65536)
+ return NULL;
+ p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC);
+ if (p == NULL)
+ return NULL;
+ p->used = 0;
+ p->size = size;
+ p->next = NULL;
+ p->commit = 0;
+ p->read = 0;
+ p->char_buf_ptr = (char *)(p->data);
+ p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size;
+ tty->buf.memory_used += size;
+ return p;
+}
+
+/**
+ * tty_buffer_free - free a tty buffer
+ * @tty: tty owning the buffer
+ * @b: the buffer to free
+ *
+ * Free a tty buffer, or add it to the free list according to our
+ * internal strategy
+ *
+ * Locking: Caller must hold tty->buf.lock
+ */
+
+static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
+{
+ /* Dumb strategy for now - should keep some stats */
+ tty->buf.memory_used -= b->size;
+ WARN_ON(tty->buf.memory_used < 0);
+
+ if (b->size >= 512)
+ kfree(b);
+ else {
+ b->next = tty->buf.free;
+ tty->buf.free = b;
+ }
+}
+
+/**
+ * __tty_buffer_flush - flush full tty buffers
+ * @tty: tty to flush
+ *
+ * flush all the buffers containing receive data. Caller must
+ * hold the buffer lock and must have ensured no parallel flush to
+ * ldisc is running.
+ *
+ * Locking: Caller must hold tty->buf.lock
+ */
+
+static void __tty_buffer_flush(struct tty_struct *tty)
+{
+ struct tty_buffer *thead;
+
+ while ((thead = tty->buf.head) != NULL) {
+ tty->buf.head = thead->next;
+ tty_buffer_free(tty, thead);
+ }
+ tty->buf.tail = NULL;
+}
+
+/**
+ * tty_buffer_flush - flush full tty buffers
+ * @tty: tty to flush
+ *
+ * flush all the buffers containing receive data. If the buffer is
+ * being processed by flush_to_ldisc then we defer the processing
+ * to that function
+ *
+ * Locking: none
+ */
+
+void tty_buffer_flush(struct tty_struct *tty)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&tty->buf.lock, flags);
+
+ /* If the data is being pushed to the tty layer then we can't
+ process it here. Instead set a flag and the flush_to_ldisc
+ path will process the flush request before it exits */
+ if (test_bit(TTY_FLUSHING, &tty->flags)) {
+ set_bit(TTY_FLUSHPENDING, &tty->flags);
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ wait_event(tty->read_wait,
+ test_bit(TTY_FLUSHPENDING, &tty->flags) == 0);
+ return;
+ } else
+ __tty_buffer_flush(tty);
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+}
+
+/**
+ * tty_buffer_find - find a free tty buffer
+ * @tty: tty owning the buffer
+ * @size: characters wanted
+ *
+ * Locate an existing suitable tty buffer or if we are lacking one then
+ * allocate a new one. We round our buffers off in 256 character chunks
+ * to get better allocation behaviour.
+ *
+ * Locking: Caller must hold tty->buf.lock
+ */
+
+static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
+{
+ struct tty_buffer **tbh = &tty->buf.free;
+ while ((*tbh) != NULL) {
+ struct tty_buffer *t = *tbh;
+ if (t->size >= size) {
+ *tbh = t->next;
+ t->next = NULL;
+ t->used = 0;
+ t->commit = 0;
+ t->read = 0;
+ tty->buf.memory_used += t->size;
+ return t;
+ }
+ tbh = &((*tbh)->next);
+ }
+ /* Round the buffer size out */
+ size = (size + 0xFF) & ~0xFF;
+ return tty_buffer_alloc(tty, size);
+ /* Should possibly check if this fails for the largest buffer we
+ have queued and recycle that ? */
+}
+
+/**
+ * tty_buffer_request_room - grow tty buffer if needed
+ * @tty: tty structure
+ * @size: size desired
+ *
+ * Make at least size bytes of linear space available for the tty
+ * buffer. If we fail return the size we managed to find.
+ *
+ * Locking: Takes tty->buf.lock
+ */
+int tty_buffer_request_room(struct tty_struct *tty, size_t size)
+{
+ struct tty_buffer *b, *n;
+ int left;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tty->buf.lock, flags);
+
+ /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
+ remove this conditional if its worth it. This would be invisible
+ to the callers */
+ if ((b = tty->buf.tail) != NULL)
+ left = b->size - b->used;
+ else
+ left = 0;
+
+ if (left < size) {
+ /* This is the slow path - looking for new buffers to use */
+ if ((n = tty_buffer_find(tty, size)) != NULL) {
+ if (b != NULL) {
+ b->next = n;
+ b->commit = b->used;
+ } else
+ tty->buf.head = n;
+ tty->buf.tail = n;
+ } else
+ size = left;
+ }
+
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ return size;
+}
+EXPORT_SYMBOL_GPL(tty_buffer_request_room);
+
+/**
+ * tty_insert_flip_string_fixed_flag - Add characters to the tty buffer
+ * @tty: tty structure
+ * @chars: characters
+ * @flag: flag value for each character
+ * @size: size
+ *
+ * Queue a series of bytes to the tty buffering. All the characters
+ * passed are marked with the supplied flag. Returns the number added.
+ *
+ * Locking: Called functions may take tty->buf.lock
+ */
+
+int tty_insert_flip_string_fixed_flag(struct tty_struct *tty,
+ const unsigned char *chars, char flag, size_t size)
+{
+ int copied = 0;
+ do {
+ int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
+ int space = tty_buffer_request_room(tty, goal);
+ struct tty_buffer *tb = tty->buf.tail;
+ /* If there is no space then tb may be NULL */
+ if (unlikely(space == 0))
+ break;
+ memcpy(tb->char_buf_ptr + tb->used, chars, space);
+ memset(tb->flag_buf_ptr + tb->used, flag, space);
+ tb->used += space;
+ copied += space;
+ chars += space;
+ /* There is a small chance that we need to split the data over
+ several buffers. If this is the case we must loop */
+ } while (unlikely(size > copied));
+ return copied;
+}
+EXPORT_SYMBOL(tty_insert_flip_string_fixed_flag);
+
+/**
+ * tty_insert_flip_string_flags - Add characters to the tty buffer
+ * @tty: tty structure
+ * @chars: characters
+ * @flags: flag bytes
+ * @size: size
+ *
+ * Queue a series of bytes to the tty buffering. For each character
+ * the flags array indicates the status of the character. Returns the
+ * number added.
+ *
+ * Locking: Called functions may take tty->buf.lock
+ */
+
+int tty_insert_flip_string_flags(struct tty_struct *tty,
+ const unsigned char *chars, const char *flags, size_t size)
+{
+ int copied = 0;
+ do {
+ int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE);
+ int space = tty_buffer_request_room(tty, goal);
+ struct tty_buffer *tb = tty->buf.tail;
+ /* If there is no space then tb may be NULL */
+ if (unlikely(space == 0))
+ break;
+ memcpy(tb->char_buf_ptr + tb->used, chars, space);
+ memcpy(tb->flag_buf_ptr + tb->used, flags, space);
+ tb->used += space;
+ copied += space;
+ chars += space;
+ flags += space;
+ /* There is a small chance that we need to split the data over
+ several buffers. If this is the case we must loop */
+ } while (unlikely(size > copied));
+ return copied;
+}
+EXPORT_SYMBOL(tty_insert_flip_string_flags);
+
+/**
+ * tty_schedule_flip - push characters to ldisc
+ * @tty: tty to push from
+ *
+ * Takes any pending buffers and transfers their ownership to the
+ * ldisc side of the queue. It then schedules those characters for
+ * processing by the line discipline.
+ *
+ * Locking: Takes tty->buf.lock
+ */
+
+void tty_schedule_flip(struct tty_struct *tty)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ if (tty->buf.tail != NULL)
+ tty->buf.tail->commit = tty->buf.tail->used;
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ schedule_delayed_work(&tty->buf.work, 1);
+}
+EXPORT_SYMBOL(tty_schedule_flip);
+
+/**
+ * tty_prepare_flip_string - make room for characters
+ * @tty: tty
+ * @chars: return pointer for character write area
+ * @size: desired size
+ *
+ * Prepare a block of space in the buffer for data. Returns the length
+ * available and buffer pointer to the space which is now allocated and
+ * accounted for as ready for normal characters. This is used for drivers
+ * that need their own block copy routines into the buffer. There is no
+ * guarantee the buffer is a DMA target!
+ *
+ * Locking: May call functions taking tty->buf.lock
+ */
+
+int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
+ size_t size)
+{
+ int space = tty_buffer_request_room(tty, size);
+ if (likely(space)) {
+ struct tty_buffer *tb = tty->buf.tail;
+ *chars = tb->char_buf_ptr + tb->used;
+ memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
+ tb->used += space;
+ }
+ return space;
+}
+EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
+
+/**
+ * tty_prepare_flip_string_flags - make room for characters
+ * @tty: tty
+ * @chars: return pointer for character write area
+ * @flags: return pointer for status flag write area
+ * @size: desired size
+ *
+ * Prepare a block of space in the buffer for data. Returns the length
+ * available and buffer pointer to the space which is now allocated and
+ * accounted for as ready for characters. This is used for drivers
+ * that need their own block copy routines into the buffer. There is no
+ * guarantee the buffer is a DMA target!
+ *
+ * Locking: May call functions taking tty->buf.lock
+ */
+
+int tty_prepare_flip_string_flags(struct tty_struct *tty,
+ unsigned char **chars, char **flags, size_t size)
+{
+ int space = tty_buffer_request_room(tty, size);
+ if (likely(space)) {
+ struct tty_buffer *tb = tty->buf.tail;
+ *chars = tb->char_buf_ptr + tb->used;
+ *flags = tb->flag_buf_ptr + tb->used;
+ tb->used += space;
+ }
+ return space;
+}
+EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
+
+
+
+/**
+ * flush_to_ldisc
+ * @work: tty structure passed from work queue.
+ *
+ * This routine is called out of the software interrupt to flush data
+ * from the buffer chain to the line discipline.
+ *
+ * Locking: holds tty->buf.lock to guard buffer list. Drops the lock
+ * while invoking the line discipline receive_buf method. The
+ * receive_buf method is single threaded for each tty instance.
+ */
+
+static void flush_to_ldisc(struct work_struct *work)
+{
+ struct tty_struct *tty =
+ container_of(work, struct tty_struct, buf.work.work);
+ unsigned long flags;
+ struct tty_ldisc *disc;
+
+ disc = tty_ldisc_ref(tty);
+ if (disc == NULL) /* !TTY_LDISC */
+ return;
+
+ spin_lock_irqsave(&tty->buf.lock, flags);
+
+ if (!test_and_set_bit(TTY_FLUSHING, &tty->flags)) {
+ struct tty_buffer *head;
+ while ((head = tty->buf.head) != NULL) {
+ int count;
+ char *char_buf;
+ unsigned char *flag_buf;
+
+ count = head->commit - head->read;
+ if (!count) {
+ if (head->next == NULL)
+ break;
+ tty->buf.head = head->next;
+ tty_buffer_free(tty, head);
+ continue;
+ }
+ /* Ldisc or user is trying to flush the buffers
+ we are feeding to the ldisc, stop feeding the
+ line discipline as we want to empty the queue */
+ if (test_bit(TTY_FLUSHPENDING, &tty->flags))
+ break;
+ if (!tty->receive_room) {
+ schedule_delayed_work(&tty->buf.work, 1);
+ break;
+ }
+ if (count > tty->receive_room)
+ count = tty->receive_room;
+ char_buf = head->char_buf_ptr + head->read;
+ flag_buf = head->flag_buf_ptr + head->read;
+ head->read += count;
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+ disc->ops->receive_buf(tty, char_buf,
+ flag_buf, count);
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ }
+ clear_bit(TTY_FLUSHING, &tty->flags);
+ }
+
+ /* We may have a deferred request to flush the input buffer,
+ if so pull the chain under the lock and empty the queue */
+ if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
+ __tty_buffer_flush(tty);
+ clear_bit(TTY_FLUSHPENDING, &tty->flags);
+ wake_up(&tty->read_wait);
+ }
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+
+ tty_ldisc_deref(disc);
+}
+
+/**
+ * tty_flush_to_ldisc
+ * @tty: tty to push
+ *
+ * Push the terminal flip buffers to the line discipline.
+ *
+ * Must not be called from IRQ context.
+ */
+void tty_flush_to_ldisc(struct tty_struct *tty)
+{
+ flush_delayed_work(&tty->buf.work);
+}
+
+/**
+ * tty_flip_buffer_push - terminal
+ * @tty: tty to push
+ *
+ * Queue a push of the terminal flip buffers to the line discipline. This
+ * function must not be called from IRQ context if tty->low_latency is set.
+ *
+ * In the event of the queue being busy for flipping the work will be
+ * held off and retried later.
+ *
+ * Locking: tty buffer lock. Driver locks in low latency mode.
+ */
+
+void tty_flip_buffer_push(struct tty_struct *tty)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&tty->buf.lock, flags);
+ if (tty->buf.tail != NULL)
+ tty->buf.tail->commit = tty->buf.tail->used;
+ spin_unlock_irqrestore(&tty->buf.lock, flags);
+
+ if (tty->low_latency)
+ flush_to_ldisc(&tty->buf.work.work);
+ else
+ schedule_delayed_work(&tty->buf.work, 1);
+}
+EXPORT_SYMBOL(tty_flip_buffer_push);
+
+/**
+ * tty_buffer_init - prepare a tty buffer structure
+ * @tty: tty to initialise
+ *
+ * Set up the initial state of the buffer management for a tty device.
+ * Must be called before the other tty buffer functions are used.
+ *
+ * Locking: none
+ */
+
+void tty_buffer_init(struct tty_struct *tty)
+{
+ spin_lock_init(&tty->buf.lock);
+ tty->buf.head = NULL;
+ tty->buf.tail = NULL;
+ tty->buf.free = NULL;
+ tty->buf.memory_used = 0;
+ INIT_DELAYED_WORK(&tty->buf.work, flush_to_ldisc);
+}
+
--- /dev/null
+/*
+ * linux/drivers/char/tty_io.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ */
+
+/*
+ * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
+ * or rs-channels. It also implements echoing, cooked mode etc.
+ *
+ * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
+ *
+ * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
+ * tty_struct and tty_queue structures. Previously there was an array
+ * of 256 tty_struct's which was statically allocated, and the
+ * tty_queue structures were allocated at boot time. Both are now
+ * dynamically allocated only when the tty is open.
+ *
+ * Also restructured routines so that there is more of a separation
+ * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
+ * the low-level tty routines (serial.c, pty.c, console.c). This
+ * makes for cleaner and more compact code. -TYT, 9/17/92
+ *
+ * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
+ * which can be dynamically activated and de-activated by the line
+ * discipline handling modules (like SLIP).
+ *
+ * NOTE: pay no attention to the line discipline code (yet); its
+ * interface is still subject to change in this version...
+ * -- TYT, 1/31/92
+ *
+ * Added functionality to the OPOST tty handling. No delays, but all
+ * other bits should be there.
+ * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
+ *
+ * Rewrote canonical mode and added more termios flags.
+ * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
+ *
+ * Reorganized FASYNC support so mouse code can share it.
+ * -- ctm@ardi.com, 9Sep95
+ *
+ * New TIOCLINUX variants added.
+ * -- mj@k332.feld.cvut.cz, 19-Nov-95
+ *
+ * Restrict vt switching via ioctl()
+ * -- grif@cs.ucr.edu, 5-Dec-95
+ *
+ * Move console and virtual terminal code to more appropriate files,
+ * implement CONFIG_VT and generalize console device interface.
+ * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
+ *
+ * Rewrote tty_init_dev and tty_release_dev to eliminate races.
+ * -- Bill Hawes <whawes@star.net>, June 97
+ *
+ * Added devfs support.
+ * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
+ *
+ * Added support for a Unix98-style ptmx device.
+ * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
+ *
+ * Reduced memory usage for older ARM systems
+ * -- Russell King <rmk@arm.linux.org.uk>
+ *
+ * Move do_SAK() into process context. Less stack use in devfs functions.
+ * alloc_tty_struct() always uses kmalloc()
+ * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
+ */
+
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/devpts_fs.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/console.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/kd.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/smp_lock.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/seq_file.h>
+#include <linux/serial.h>
+
+#include <linux/uaccess.h>
+#include <asm/system.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+
+#include <linux/kmod.h>
+#include <linux/nsproxy.h>
+
+#undef TTY_DEBUG_HANGUP
+
+#define TTY_PARANOIA_CHECK 1
+#define CHECK_TTY_COUNT 1
+
+struct ktermios tty_std_termios = { /* for the benefit of tty drivers */
+ .c_iflag = ICRNL | IXON,
+ .c_oflag = OPOST | ONLCR,
+ .c_cflag = B38400 | CS8 | CREAD | HUPCL,
+ .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
+ ECHOCTL | ECHOKE | IEXTEN,
+ .c_cc = INIT_C_CC,
+ .c_ispeed = 38400,
+ .c_ospeed = 38400
+};
+
+EXPORT_SYMBOL(tty_std_termios);
+
+/* This list gets poked at by procfs and various bits of boot up code. This
+ could do with some rationalisation such as pulling the tty proc function
+ into this file */
+
+LIST_HEAD(tty_drivers); /* linked list of tty drivers */
+
+/* Mutex to protect creating and releasing a tty. This is shared with
+ vt.c for deeply disgusting hack reasons */
+DEFINE_MUTEX(tty_mutex);
+EXPORT_SYMBOL(tty_mutex);
+
+/* Spinlock to protect the tty->tty_files list */
+DEFINE_SPINLOCK(tty_files_lock);
+
+static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
+static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
+ssize_t redirected_tty_write(struct file *, const char __user *,
+ size_t, loff_t *);
+static unsigned int tty_poll(struct file *, poll_table *);
+static int tty_open(struct inode *, struct file *);
+long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+#ifdef CONFIG_COMPAT
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg);
+#else
+#define tty_compat_ioctl NULL
+#endif
+static int __tty_fasync(int fd, struct file *filp, int on);
+static int tty_fasync(int fd, struct file *filp, int on);
+static void release_tty(struct tty_struct *tty, int idx);
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
+static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
+
+/**
+ * alloc_tty_struct - allocate a tty object
+ *
+ * Return a new empty tty structure. The data fields have not
+ * been initialized in any way but has been zeroed
+ *
+ * Locking: none
+ */
+
+struct tty_struct *alloc_tty_struct(void)
+{
+ return kzalloc(sizeof(struct tty_struct), GFP_KERNEL);
+}
+
+/**
+ * free_tty_struct - free a disused tty
+ * @tty: tty struct to free
+ *
+ * Free the write buffers, tty queue and tty memory itself.
+ *
+ * Locking: none. Must be called after tty is definitely unused
+ */
+
+void free_tty_struct(struct tty_struct *tty)
+{
+ if (tty->dev)
+ put_device(tty->dev);
+ kfree(tty->write_buf);
+ tty_buffer_free_all(tty);
+ kfree(tty);
+}
+
+static inline struct tty_struct *file_tty(struct file *file)
+{
+ return ((struct tty_file_private *)file->private_data)->tty;
+}
+
+/* Associate a new file with the tty structure */
+int tty_add_file(struct tty_struct *tty, struct file *file)
+{
+ struct tty_file_private *priv;
+
+ priv = kmalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->tty = tty;
+ priv->file = file;
+ file->private_data = priv;
+
+ spin_lock(&tty_files_lock);
+ list_add(&priv->list, &tty->tty_files);
+ spin_unlock(&tty_files_lock);
+
+ return 0;
+}
+
+/* Delete file from its tty */
+void tty_del_file(struct file *file)
+{
+ struct tty_file_private *priv = file->private_data;
+
+ spin_lock(&tty_files_lock);
+ list_del(&priv->list);
+ spin_unlock(&tty_files_lock);
+ file->private_data = NULL;
+ kfree(priv);
+}
+
+
+#define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
+
+/**
+ * tty_name - return tty naming
+ * @tty: tty structure
+ * @buf: buffer for output
+ *
+ * Convert a tty structure into a name. The name reflects the kernel
+ * naming policy and if udev is in use may not reflect user space
+ *
+ * Locking: none
+ */
+
+char *tty_name(struct tty_struct *tty, char *buf)
+{
+ if (!tty) /* Hmm. NULL pointer. That's fun. */
+ strcpy(buf, "NULL tty");
+ else
+ strcpy(buf, tty->name);
+ return buf;
+}
+
+EXPORT_SYMBOL(tty_name);
+
+int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
+ const char *routine)
+{
+#ifdef TTY_PARANOIA_CHECK
+ if (!tty) {
+ printk(KERN_WARNING
+ "null TTY for (%d:%d) in %s\n",
+ imajor(inode), iminor(inode), routine);
+ return 1;
+ }
+ if (tty->magic != TTY_MAGIC) {
+ printk(KERN_WARNING
+ "bad magic number for tty struct (%d:%d) in %s\n",
+ imajor(inode), iminor(inode), routine);
+ return 1;
+ }
+#endif
+ return 0;
+}
+
+static int check_tty_count(struct tty_struct *tty, const char *routine)
+{
+#ifdef CHECK_TTY_COUNT
+ struct list_head *p;
+ int count = 0;
+
+ spin_lock(&tty_files_lock);
+ list_for_each(p, &tty->tty_files) {
+ count++;
+ }
+ spin_unlock(&tty_files_lock);
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_SLAVE &&
+ tty->link && tty->link->count)
+ count++;
+ if (tty->count != count) {
+ printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) "
+ "!= #fd's(%d) in %s\n",
+ tty->name, tty->count, count, routine);
+ return count;
+ }
+#endif
+ return 0;
+}
+
+/**
+ * get_tty_driver - find device of a tty
+ * @dev_t: device identifier
+ * @index: returns the index of the tty
+ *
+ * This routine returns a tty driver structure, given a device number
+ * and also passes back the index number.
+ *
+ * Locking: caller must hold tty_mutex
+ */
+
+static struct tty_driver *get_tty_driver(dev_t device, int *index)
+{
+ struct tty_driver *p;
+
+ list_for_each_entry(p, &tty_drivers, tty_drivers) {
+ dev_t base = MKDEV(p->major, p->minor_start);
+ if (device < base || device >= base + p->num)
+ continue;
+ *index = device - base;
+ return tty_driver_kref_get(p);
+ }
+ return NULL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+/**
+ * tty_find_polling_driver - find device of a polled tty
+ * @name: name string to match
+ * @line: pointer to resulting tty line nr
+ *
+ * This routine returns a tty driver structure, given a name
+ * and the condition that the tty driver is capable of polled
+ * operation.
+ */
+struct tty_driver *tty_find_polling_driver(char *name, int *line)
+{
+ struct tty_driver *p, *res = NULL;
+ int tty_line = 0;
+ int len;
+ char *str, *stp;
+
+ for (str = name; *str; str++)
+ if ((*str >= '0' && *str <= '9') || *str == ',')
+ break;
+ if (!*str)
+ return NULL;
+
+ len = str - name;
+ tty_line = simple_strtoul(str, &str, 10);
+
+ mutex_lock(&tty_mutex);
+ /* Search through the tty devices to look for a match */
+ list_for_each_entry(p, &tty_drivers, tty_drivers) {
+ if (strncmp(name, p->name, len) != 0)
+ continue;
+ stp = str;
+ if (*stp == ',')
+ stp++;
+ if (*stp == '\0')
+ stp = NULL;
+
+ if (tty_line >= 0 && tty_line < p->num && p->ops &&
+ p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) {
+ res = tty_driver_kref_get(p);
+ *line = tty_line;
+ break;
+ }
+ }
+ mutex_unlock(&tty_mutex);
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(tty_find_polling_driver);
+#endif
+
+/**
+ * tty_check_change - check for POSIX terminal changes
+ * @tty: tty to check
+ *
+ * If we try to write to, or set the state of, a terminal and we're
+ * not in the foreground, send a SIGTTOU. If the signal is blocked or
+ * ignored, go ahead and perform the operation. (POSIX 7.2)
+ *
+ * Locking: ctrl_lock
+ */
+
+int tty_check_change(struct tty_struct *tty)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ if (current->signal->tty != tty)
+ return 0;
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+
+ if (!tty->pgrp) {
+ printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n");
+ goto out_unlock;
+ }
+ if (task_pgrp(current) == tty->pgrp)
+ goto out_unlock;
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ if (is_ignored(SIGTTOU))
+ goto out;
+ if (is_current_pgrp_orphaned()) {
+ ret = -EIO;
+ goto out;
+ }
+ kill_pgrp(task_pgrp(current), SIGTTOU, 1);
+ set_thread_flag(TIF_SIGPENDING);
+ ret = -ERESTARTSYS;
+out:
+ return ret;
+out_unlock:
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ return ret;
+}
+
+EXPORT_SYMBOL(tty_check_change);
+
+static ssize_t hung_up_tty_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return 0;
+}
+
+static ssize_t hung_up_tty_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return -EIO;
+}
+
+/* No kernel lock held - none needed ;) */
+static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait)
+{
+ return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;
+}
+
+static long hung_up_tty_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
+}
+
+static long hung_up_tty_compat_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
+}
+
+static const struct file_operations tty_fops = {
+ .llseek = no_llseek,
+ .read = tty_read,
+ .write = tty_write,
+ .poll = tty_poll,
+ .unlocked_ioctl = tty_ioctl,
+ .compat_ioctl = tty_compat_ioctl,
+ .open = tty_open,
+ .release = tty_release,
+ .fasync = tty_fasync,
+};
+
+static const struct file_operations console_fops = {
+ .llseek = no_llseek,
+ .read = tty_read,
+ .write = redirected_tty_write,
+ .poll = tty_poll,
+ .unlocked_ioctl = tty_ioctl,
+ .compat_ioctl = tty_compat_ioctl,
+ .open = tty_open,
+ .release = tty_release,
+ .fasync = tty_fasync,
+};
+
+static const struct file_operations hung_up_tty_fops = {
+ .llseek = no_llseek,
+ .read = hung_up_tty_read,
+ .write = hung_up_tty_write,
+ .poll = hung_up_tty_poll,
+ .unlocked_ioctl = hung_up_tty_ioctl,
+ .compat_ioctl = hung_up_tty_compat_ioctl,
+ .release = tty_release,
+};
+
+static DEFINE_SPINLOCK(redirect_lock);
+static struct file *redirect;
+
+/**
+ * tty_wakeup - request more data
+ * @tty: terminal
+ *
+ * Internal and external helper for wakeups of tty. This function
+ * informs the line discipline if present that the driver is ready
+ * to receive more output data.
+ */
+
+void tty_wakeup(struct tty_struct *tty)
+{
+ struct tty_ldisc *ld;
+
+ if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
+ ld = tty_ldisc_ref(tty);
+ if (ld) {
+ if (ld->ops->write_wakeup)
+ ld->ops->write_wakeup(tty);
+ tty_ldisc_deref(ld);
+ }
+ }
+ wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+}
+
+EXPORT_SYMBOL_GPL(tty_wakeup);
+
+/**
+ * __tty_hangup - actual handler for hangup events
+ * @work: tty device
+ *
+ * This can be called by the "eventd" kernel thread. That is process
+ * synchronous but doesn't hold any locks, so we need to make sure we
+ * have the appropriate locks for what we're doing.
+ *
+ * The hangup event clears any pending redirections onto the hung up
+ * device. It ensures future writes will error and it does the needed
+ * line discipline hangup and signal delivery. The tty object itself
+ * remains intact.
+ *
+ * Locking:
+ * BTM
+ * redirect lock for undoing redirection
+ * file list lock for manipulating list of ttys
+ * tty_ldisc_lock from called functions
+ * termios_mutex resetting termios data
+ * tasklist_lock to walk task list for hangup event
+ * ->siglock to protect ->signal/->sighand
+ */
+void __tty_hangup(struct tty_struct *tty)
+{
+ struct file *cons_filp = NULL;
+ struct file *filp, *f = NULL;
+ struct task_struct *p;
+ struct tty_file_private *priv;
+ int closecount = 0, n;
+ unsigned long flags;
+ int refs = 0;
+
+ if (!tty)
+ return;
+
+
+ spin_lock(&redirect_lock);
+ if (redirect && file_tty(redirect) == tty) {
+ f = redirect;
+ redirect = NULL;
+ }
+ spin_unlock(&redirect_lock);
+
+ tty_lock();
+
+ /* inuse_filps is protected by the single tty lock,
+ this really needs to change if we want to flush the
+ workqueue with the lock held */
+ check_tty_count(tty, "tty_hangup");
+
+ spin_lock(&tty_files_lock);
+ /* This breaks for file handles being sent over AF_UNIX sockets ? */
+ list_for_each_entry(priv, &tty->tty_files, list) {
+ filp = priv->file;
+ if (filp->f_op->write == redirected_tty_write)
+ cons_filp = filp;
+ if (filp->f_op->write != tty_write)
+ continue;
+ closecount++;
+ __tty_fasync(-1, filp, 0); /* can't block */
+ filp->f_op = &hung_up_tty_fops;
+ }
+ spin_unlock(&tty_files_lock);
+
+ tty_ldisc_hangup(tty);
+
+ read_lock(&tasklist_lock);
+ if (tty->session) {
+ do_each_pid_task(tty->session, PIDTYPE_SID, p) {
+ spin_lock_irq(&p->sighand->siglock);
+ if (p->signal->tty == tty) {
+ p->signal->tty = NULL;
+ /* We defer the dereferences outside fo
+ the tasklist lock */
+ refs++;
+ }
+ if (!p->signal->leader) {
+ spin_unlock_irq(&p->sighand->siglock);
+ continue;
+ }
+ __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);
+ __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);
+ put_pid(p->signal->tty_old_pgrp); /* A noop */
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ if (tty->pgrp)
+ p->signal->tty_old_pgrp = get_pid(tty->pgrp);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ spin_unlock_irq(&p->sighand->siglock);
+ } while_each_pid_task(tty->session, PIDTYPE_SID, p);
+ }
+ read_unlock(&tasklist_lock);
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ clear_bit(TTY_THROTTLED, &tty->flags);
+ clear_bit(TTY_PUSH, &tty->flags);
+ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+ put_pid(tty->session);
+ put_pid(tty->pgrp);
+ tty->session = NULL;
+ tty->pgrp = NULL;
+ tty->ctrl_status = 0;
+ set_bit(TTY_HUPPED, &tty->flags);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+ /* Account for the p->signal references we killed */
+ while (refs--)
+ tty_kref_put(tty);
+
+ /*
+ * If one of the devices matches a console pointer, we
+ * cannot just call hangup() because that will cause
+ * tty->count and state->count to go out of sync.
+ * So we just call close() the right number of times.
+ */
+ if (cons_filp) {
+ if (tty->ops->close)
+ for (n = 0; n < closecount; n++)
+ tty->ops->close(tty, cons_filp);
+ } else if (tty->ops->hangup)
+ (tty->ops->hangup)(tty);
+ /*
+ * We don't want to have driver/ldisc interactions beyond
+ * the ones we did here. The driver layer expects no
+ * calls after ->hangup() from the ldisc side. However we
+ * can't yet guarantee all that.
+ */
+ set_bit(TTY_HUPPED, &tty->flags);
+ tty_ldisc_enable(tty);
+
+ tty_unlock();
+
+ if (f)
+ fput(f);
+}
+
+static void do_tty_hangup(struct work_struct *work)
+{
+ struct tty_struct *tty =
+ container_of(work, struct tty_struct, hangup_work);
+
+ __tty_hangup(tty);
+}
+
+/**
+ * tty_hangup - trigger a hangup event
+ * @tty: tty to hangup
+ *
+ * A carrier loss (virtual or otherwise) has occurred on this like
+ * schedule a hangup sequence to run after this event.
+ */
+
+void tty_hangup(struct tty_struct *tty)
+{
+#ifdef TTY_DEBUG_HANGUP
+ char buf[64];
+ printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf));
+#endif
+ schedule_work(&tty->hangup_work);
+}
+
+EXPORT_SYMBOL(tty_hangup);
+
+/**
+ * tty_vhangup - process vhangup
+ * @tty: tty to hangup
+ *
+ * The user has asked via system call for the terminal to be hung up.
+ * We do this synchronously so that when the syscall returns the process
+ * is complete. That guarantee is necessary for security reasons.
+ */
+
+void tty_vhangup(struct tty_struct *tty)
+{
+#ifdef TTY_DEBUG_HANGUP
+ char buf[64];
+
+ printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf));
+#endif
+ __tty_hangup(tty);
+}
+
+EXPORT_SYMBOL(tty_vhangup);
+
+
+/**
+ * tty_vhangup_self - process vhangup for own ctty
+ *
+ * Perform a vhangup on the current controlling tty
+ */
+
+void tty_vhangup_self(void)
+{
+ struct tty_struct *tty;
+
+ tty = get_current_tty();
+ if (tty) {
+ tty_vhangup(tty);
+ tty_kref_put(tty);
+ }
+}
+
+/**
+ * tty_hung_up_p - was tty hung up
+ * @filp: file pointer of tty
+ *
+ * Return true if the tty has been subject to a vhangup or a carrier
+ * loss
+ */
+
+int tty_hung_up_p(struct file *filp)
+{
+ return (filp->f_op == &hung_up_tty_fops);
+}
+
+EXPORT_SYMBOL(tty_hung_up_p);
+
+static void session_clear_tty(struct pid *session)
+{
+ struct task_struct *p;
+ do_each_pid_task(session, PIDTYPE_SID, p) {
+ proc_clear_tty(p);
+ } while_each_pid_task(session, PIDTYPE_SID, p);
+}
+
+/**
+ * disassociate_ctty - disconnect controlling tty
+ * @on_exit: true if exiting so need to "hang up" the session
+ *
+ * This function is typically called only by the session leader, when
+ * it wants to disassociate itself from its controlling tty.
+ *
+ * It performs the following functions:
+ * (1) Sends a SIGHUP and SIGCONT to the foreground process group
+ * (2) Clears the tty from being controlling the session
+ * (3) Clears the controlling tty for all processes in the
+ * session group.
+ *
+ * The argument on_exit is set to 1 if called when a process is
+ * exiting; it is 0 if called by the ioctl TIOCNOTTY.
+ *
+ * Locking:
+ * BTM is taken for hysterical raisins, and held when
+ * called from no_tty().
+ * tty_mutex is taken to protect tty
+ * ->siglock is taken to protect ->signal/->sighand
+ * tasklist_lock is taken to walk process list for sessions
+ * ->siglock is taken to protect ->signal/->sighand
+ */
+
+void disassociate_ctty(int on_exit)
+{
+ struct tty_struct *tty;
+ struct pid *tty_pgrp = NULL;
+
+ if (!current->signal->leader)
+ return;
+
+ tty = get_current_tty();
+ if (tty) {
+ tty_pgrp = get_pid(tty->pgrp);
+ if (on_exit) {
+ if (tty->driver->type != TTY_DRIVER_TYPE_PTY)
+ tty_vhangup(tty);
+ }
+ tty_kref_put(tty);
+ } else if (on_exit) {
+ struct pid *old_pgrp;
+ spin_lock_irq(¤t->sighand->siglock);
+ old_pgrp = current->signal->tty_old_pgrp;
+ current->signal->tty_old_pgrp = NULL;
+ spin_unlock_irq(¤t->sighand->siglock);
+ if (old_pgrp) {
+ kill_pgrp(old_pgrp, SIGHUP, on_exit);
+ kill_pgrp(old_pgrp, SIGCONT, on_exit);
+ put_pid(old_pgrp);
+ }
+ return;
+ }
+ if (tty_pgrp) {
+ kill_pgrp(tty_pgrp, SIGHUP, on_exit);
+ if (!on_exit)
+ kill_pgrp(tty_pgrp, SIGCONT, on_exit);
+ put_pid(tty_pgrp);
+ }
+
+ spin_lock_irq(¤t->sighand->siglock);
+ put_pid(current->signal->tty_old_pgrp);
+ current->signal->tty_old_pgrp = NULL;
+ spin_unlock_irq(¤t->sighand->siglock);
+
+ tty = get_current_tty();
+ if (tty) {
+ unsigned long flags;
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ put_pid(tty->session);
+ put_pid(tty->pgrp);
+ tty->session = NULL;
+ tty->pgrp = NULL;
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ tty_kref_put(tty);
+ } else {
+#ifdef TTY_DEBUG_HANGUP
+ printk(KERN_DEBUG "error attempted to write to tty [0x%p]"
+ " = NULL", tty);
+#endif
+ }
+
+ /* Now clear signal->tty under the lock */
+ read_lock(&tasklist_lock);
+ session_clear_tty(task_session(current));
+ read_unlock(&tasklist_lock);
+}
+
+/**
+ *
+ * no_tty - Ensure the current process does not have a controlling tty
+ */
+void no_tty(void)
+{
+ struct task_struct *tsk = current;
+ tty_lock();
+ disassociate_ctty(0);
+ tty_unlock();
+ proc_clear_tty(tsk);
+}
+
+
+/**
+ * stop_tty - propagate flow control
+ * @tty: tty to stop
+ *
+ * Perform flow control to the driver. For PTY/TTY pairs we
+ * must also propagate the TIOCKPKT status. May be called
+ * on an already stopped device and will not re-call the driver
+ * method.
+ *
+ * This functionality is used by both the line disciplines for
+ * halting incoming flow and by the driver. It may therefore be
+ * called from any context, may be under the tty atomic_write_lock
+ * but not always.
+ *
+ * Locking:
+ * Uses the tty control lock internally
+ */
+
+void stop_tty(struct tty_struct *tty)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ if (tty->stopped) {
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ return;
+ }
+ tty->stopped = 1;
+ if (tty->link && tty->link->packet) {
+ tty->ctrl_status &= ~TIOCPKT_START;
+ tty->ctrl_status |= TIOCPKT_STOP;
+ wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
+ }
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ if (tty->ops->stop)
+ (tty->ops->stop)(tty);
+}
+
+EXPORT_SYMBOL(stop_tty);
+
+/**
+ * start_tty - propagate flow control
+ * @tty: tty to start
+ *
+ * Start a tty that has been stopped if at all possible. Perform
+ * any necessary wakeups and propagate the TIOCPKT status. If this
+ * is the tty was previous stopped and is being started then the
+ * driver start method is invoked and the line discipline woken.
+ *
+ * Locking:
+ * ctrl_lock
+ */
+
+void start_tty(struct tty_struct *tty)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ if (!tty->stopped || tty->flow_stopped) {
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ return;
+ }
+ tty->stopped = 0;
+ if (tty->link && tty->link->packet) {
+ tty->ctrl_status &= ~TIOCPKT_STOP;
+ tty->ctrl_status |= TIOCPKT_START;
+ wake_up_interruptible_poll(&tty->link->read_wait, POLLIN);
+ }
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ if (tty->ops->start)
+ (tty->ops->start)(tty);
+ /* If we have a running line discipline it may need kicking */
+ tty_wakeup(tty);
+}
+
+EXPORT_SYMBOL(start_tty);
+
+/**
+ * tty_read - read method for tty device files
+ * @file: pointer to tty file
+ * @buf: user buffer
+ * @count: size of user buffer
+ * @ppos: unused
+ *
+ * Perform the read system call function on this terminal device. Checks
+ * for hung up devices before calling the line discipline method.
+ *
+ * Locking:
+ * Locks the line discipline internally while needed. Multiple
+ * read calls may be outstanding in parallel.
+ */
+
+static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ int i;
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct tty_struct *tty = file_tty(file);
+ struct tty_ldisc *ld;
+
+ if (tty_paranoia_check(tty, inode, "tty_read"))
+ return -EIO;
+ if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
+ return -EIO;
+
+ /* We want to wait for the line discipline to sort out in this
+ situation */
+ ld = tty_ldisc_ref_wait(tty);
+ if (ld->ops->read)
+ i = (ld->ops->read)(tty, file, buf, count);
+ else
+ i = -EIO;
+ tty_ldisc_deref(ld);
+ if (i > 0)
+ inode->i_atime = current_fs_time(inode->i_sb);
+ return i;
+}
+
+void tty_write_unlock(struct tty_struct *tty)
+{
+ mutex_unlock(&tty->atomic_write_lock);
+ wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+}
+
+int tty_write_lock(struct tty_struct *tty, int ndelay)
+{
+ if (!mutex_trylock(&tty->atomic_write_lock)) {
+ if (ndelay)
+ return -EAGAIN;
+ if (mutex_lock_interruptible(&tty->atomic_write_lock))
+ return -ERESTARTSYS;
+ }
+ return 0;
+}
+
+/*
+ * Split writes up in sane blocksizes to avoid
+ * denial-of-service type attacks
+ */
+static inline ssize_t do_tty_write(
+ ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t),
+ struct tty_struct *tty,
+ struct file *file,
+ const char __user *buf,
+ size_t count)
+{
+ ssize_t ret, written = 0;
+ unsigned int chunk;
+
+ ret = tty_write_lock(tty, file->f_flags & O_NDELAY);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * We chunk up writes into a temporary buffer. This
+ * simplifies low-level drivers immensely, since they
+ * don't have locking issues and user mode accesses.
+ *
+ * But if TTY_NO_WRITE_SPLIT is set, we should use a
+ * big chunk-size..
+ *
+ * The default chunk-size is 2kB, because the NTTY
+ * layer has problems with bigger chunks. It will
+ * claim to be able to handle more characters than
+ * it actually does.
+ *
+ * FIXME: This can probably go away now except that 64K chunks
+ * are too likely to fail unless switched to vmalloc...
+ */
+ chunk = 2048;
+ if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
+ chunk = 65536;
+ if (count < chunk)
+ chunk = count;
+
+ /* write_buf/write_cnt is protected by the atomic_write_lock mutex */
+ if (tty->write_cnt < chunk) {
+ unsigned char *buf_chunk;
+
+ if (chunk < 1024)
+ chunk = 1024;
+
+ buf_chunk = kmalloc(chunk, GFP_KERNEL);
+ if (!buf_chunk) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ kfree(tty->write_buf);
+ tty->write_cnt = chunk;
+ tty->write_buf = buf_chunk;
+ }
+
+ /* Do the write .. */
+ for (;;) {
+ size_t size = count;
+ if (size > chunk)
+ size = chunk;
+ ret = -EFAULT;
+ if (copy_from_user(tty->write_buf, buf, size))
+ break;
+ ret = write(tty, file, tty->write_buf, size);
+ if (ret <= 0)
+ break;
+ written += ret;
+ buf += ret;
+ count -= ret;
+ if (!count)
+ break;
+ ret = -ERESTARTSYS;
+ if (signal_pending(current))
+ break;
+ cond_resched();
+ }
+ if (written) {
+ struct inode *inode = file->f_path.dentry->d_inode;
+ inode->i_mtime = current_fs_time(inode->i_sb);
+ ret = written;
+ }
+out:
+ tty_write_unlock(tty);
+ return ret;
+}
+
+/**
+ * tty_write_message - write a message to a certain tty, not just the console.
+ * @tty: the destination tty_struct
+ * @msg: the message to write
+ *
+ * This is used for messages that need to be redirected to a specific tty.
+ * We don't put it into the syslog queue right now maybe in the future if
+ * really needed.
+ *
+ * We must still hold the BTM and test the CLOSING flag for the moment.
+ */
+
+void tty_write_message(struct tty_struct *tty, char *msg)
+{
+ if (tty) {
+ mutex_lock(&tty->atomic_write_lock);
+ tty_lock();
+ if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) {
+ tty_unlock();
+ tty->ops->write(tty, msg, strlen(msg));
+ } else
+ tty_unlock();
+ tty_write_unlock(tty);
+ }
+ return;
+}
+
+
+/**
+ * tty_write - write method for tty device file
+ * @file: tty file pointer
+ * @buf: user data to write
+ * @count: bytes to write
+ * @ppos: unused
+ *
+ * Write data to a tty device via the line discipline.
+ *
+ * Locking:
+ * Locks the line discipline as required
+ * Writes to the tty driver are serialized by the atomic_write_lock
+ * and are then processed in chunks to the device. The line discipline
+ * write method will not be invoked in parallel for each device.
+ */
+
+static ssize_t tty_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct tty_struct *tty = file_tty(file);
+ struct tty_ldisc *ld;
+ ssize_t ret;
+
+ if (tty_paranoia_check(tty, inode, "tty_write"))
+ return -EIO;
+ if (!tty || !tty->ops->write ||
+ (test_bit(TTY_IO_ERROR, &tty->flags)))
+ return -EIO;
+ /* Short term debug to catch buggy drivers */
+ if (tty->ops->write_room == NULL)
+ printk(KERN_ERR "tty driver %s lacks a write_room method.\n",
+ tty->driver->name);
+ ld = tty_ldisc_ref_wait(tty);
+ if (!ld->ops->write)
+ ret = -EIO;
+ else
+ ret = do_tty_write(ld->ops->write, tty, file, buf, count);
+ tty_ldisc_deref(ld);
+ return ret;
+}
+
+ssize_t redirected_tty_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct file *p = NULL;
+
+ spin_lock(&redirect_lock);
+ if (redirect) {
+ get_file(redirect);
+ p = redirect;
+ }
+ spin_unlock(&redirect_lock);
+
+ if (p) {
+ ssize_t res;
+ res = vfs_write(p, buf, count, &p->f_pos);
+ fput(p);
+ return res;
+ }
+ return tty_write(file, buf, count, ppos);
+}
+
+static char ptychar[] = "pqrstuvwxyzabcde";
+
+/**
+ * pty_line_name - generate name for a pty
+ * @driver: the tty driver in use
+ * @index: the minor number
+ * @p: output buffer of at least 6 bytes
+ *
+ * Generate a name from a driver reference and write it to the output
+ * buffer.
+ *
+ * Locking: None
+ */
+static void pty_line_name(struct tty_driver *driver, int index, char *p)
+{
+ int i = index + driver->name_base;
+ /* ->name is initialized to "ttyp", but "tty" is expected */
+ sprintf(p, "%s%c%x",
+ driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name,
+ ptychar[i >> 4 & 0xf], i & 0xf);
+}
+
+/**
+ * tty_line_name - generate name for a tty
+ * @driver: the tty driver in use
+ * @index: the minor number
+ * @p: output buffer of at least 7 bytes
+ *
+ * Generate a name from a driver reference and write it to the output
+ * buffer.
+ *
+ * Locking: None
+ */
+static void tty_line_name(struct tty_driver *driver, int index, char *p)
+{
+ sprintf(p, "%s%d", driver->name, index + driver->name_base);
+}
+
+/**
+ * tty_driver_lookup_tty() - find an existing tty, if any
+ * @driver: the driver for the tty
+ * @idx: the minor number
+ *
+ * Return the tty, if found or ERR_PTR() otherwise.
+ *
+ * Locking: tty_mutex must be held. If tty is found, the mutex must
+ * be held until the 'fast-open' is also done. Will change once we
+ * have refcounting in the driver and per driver locking
+ */
+static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
+ struct inode *inode, int idx)
+{
+ struct tty_struct *tty;
+
+ if (driver->ops->lookup)
+ return driver->ops->lookup(driver, inode, idx);
+
+ tty = driver->ttys[idx];
+ return tty;
+}
+
+/**
+ * tty_init_termios - helper for termios setup
+ * @tty: the tty to set up
+ *
+ * Initialise the termios structures for this tty. Thus runs under
+ * the tty_mutex currently so we can be relaxed about ordering.
+ */
+
+int tty_init_termios(struct tty_struct *tty)
+{
+ struct ktermios *tp;
+ int idx = tty->index;
+
+ tp = tty->driver->termios[idx];
+ if (tp == NULL) {
+ tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
+ if (tp == NULL)
+ return -ENOMEM;
+ memcpy(tp, &tty->driver->init_termios,
+ sizeof(struct ktermios));
+ tty->driver->termios[idx] = tp;
+ }
+ tty->termios = tp;
+ tty->termios_locked = tp + 1;
+
+ /* Compatibility until drivers always set this */
+ tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+ tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tty_init_termios);
+
+/**
+ * tty_driver_install_tty() - install a tty entry in the driver
+ * @driver: the driver for the tty
+ * @tty: the tty
+ *
+ * Install a tty object into the driver tables. The tty->index field
+ * will be set by the time this is called. This method is responsible
+ * for ensuring any need additional structures are allocated and
+ * configured.
+ *
+ * Locking: tty_mutex for now
+ */
+static int tty_driver_install_tty(struct tty_driver *driver,
+ struct tty_struct *tty)
+{
+ int idx = tty->index;
+ int ret;
+
+ if (driver->ops->install) {
+ ret = driver->ops->install(driver, tty);
+ return ret;
+ }
+
+ if (tty_init_termios(tty) == 0) {
+ tty_driver_kref_get(driver);
+ tty->count++;
+ driver->ttys[idx] = tty;
+ return 0;
+ }
+ return -ENOMEM;
+}
+
+/**
+ * tty_driver_remove_tty() - remove a tty from the driver tables
+ * @driver: the driver for the tty
+ * @idx: the minor number
+ *
+ * Remvoe a tty object from the driver tables. The tty->index field
+ * will be set by the time this is called.
+ *
+ * Locking: tty_mutex for now
+ */
+static void tty_driver_remove_tty(struct tty_driver *driver,
+ struct tty_struct *tty)
+{
+ if (driver->ops->remove)
+ driver->ops->remove(driver, tty);
+ else
+ driver->ttys[tty->index] = NULL;
+}
+
+/*
+ * tty_reopen() - fast re-open of an open tty
+ * @tty - the tty to open
+ *
+ * Return 0 on success, -errno on error.
+ *
+ * Locking: tty_mutex must be held from the time the tty was found
+ * till this open completes.
+ */
+static int tty_reopen(struct tty_struct *tty)
+{
+ struct tty_driver *driver = tty->driver;
+
+ if (test_bit(TTY_CLOSING, &tty->flags))
+ return -EIO;
+
+ if (driver->type == TTY_DRIVER_TYPE_PTY &&
+ driver->subtype == PTY_TYPE_MASTER) {
+ /*
+ * special case for PTY masters: only one open permitted,
+ * and the slave side open count is incremented as well.
+ */
+ if (tty->count)
+ return -EIO;
+
+ tty->link->count++;
+ }
+ tty->count++;
+ tty->driver = driver; /* N.B. why do this every time?? */
+
+ mutex_lock(&tty->ldisc_mutex);
+ WARN_ON(!test_bit(TTY_LDISC, &tty->flags));
+ mutex_unlock(&tty->ldisc_mutex);
+
+ return 0;
+}
+
+/**
+ * tty_init_dev - initialise a tty device
+ * @driver: tty driver we are opening a device on
+ * @idx: device index
+ * @ret_tty: returned tty structure
+ * @first_ok: ok to open a new device (used by ptmx)
+ *
+ * Prepare a tty device. This may not be a "new" clean device but
+ * could also be an active device. The pty drivers require special
+ * handling because of this.
+ *
+ * Locking:
+ * The function is called under the tty_mutex, which
+ * protects us from the tty struct or driver itself going away.
+ *
+ * On exit the tty device has the line discipline attached and
+ * a reference count of 1. If a pair was created for pty/tty use
+ * and the other was a pty master then it too has a reference count of 1.
+ *
+ * WSH 06/09/97: Rewritten to remove races and properly clean up after a
+ * failed open. The new code protects the open with a mutex, so it's
+ * really quite straightforward. The mutex locking can probably be
+ * relaxed for the (most common) case of reopening a tty.
+ */
+
+struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
+ int first_ok)
+{
+ struct tty_struct *tty;
+ int retval;
+
+ /* Check if pty master is being opened multiple times */
+ if (driver->subtype == PTY_TYPE_MASTER &&
+ (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) {
+ return ERR_PTR(-EIO);
+ }
+
+ /*
+ * First time open is complex, especially for PTY devices.
+ * This code guarantees that either everything succeeds and the
+ * TTY is ready for operation, or else the table slots are vacated
+ * and the allocated memory released. (Except that the termios
+ * and locked termios may be retained.)
+ */
+
+ if (!try_module_get(driver->owner))
+ return ERR_PTR(-ENODEV);
+
+ tty = alloc_tty_struct();
+ if (!tty)
+ goto fail_no_mem;
+ initialize_tty_struct(tty, driver, idx);
+
+ retval = tty_driver_install_tty(driver, tty);
+ if (retval < 0) {
+ free_tty_struct(tty);
+ module_put(driver->owner);
+ return ERR_PTR(retval);
+ }
+
+ /*
+ * Structures all installed ... call the ldisc open routines.
+ * If we fail here just call release_tty to clean up. No need
+ * to decrement the use counts, as release_tty doesn't care.
+ */
+ retval = tty_ldisc_setup(tty, tty->link);
+ if (retval)
+ goto release_mem_out;
+ return tty;
+
+fail_no_mem:
+ module_put(driver->owner);
+ return ERR_PTR(-ENOMEM);
+
+ /* call the tty release_tty routine to clean out this slot */
+release_mem_out:
+ if (printk_ratelimit())
+ printk(KERN_INFO "tty_init_dev: ldisc open failed, "
+ "clearing slot %d\n", idx);
+ release_tty(tty, idx);
+ return ERR_PTR(retval);
+}
+
+void tty_free_termios(struct tty_struct *tty)
+{
+ struct ktermios *tp;
+ int idx = tty->index;
+ /* Kill this flag and push into drivers for locking etc */
+ if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
+ /* FIXME: Locking on ->termios array */
+ tp = tty->termios;
+ tty->driver->termios[idx] = NULL;
+ kfree(tp);
+ }
+}
+EXPORT_SYMBOL(tty_free_termios);
+
+void tty_shutdown(struct tty_struct *tty)
+{
+ tty_driver_remove_tty(tty->driver, tty);
+ tty_free_termios(tty);
+}
+EXPORT_SYMBOL(tty_shutdown);
+
+/**
+ * release_one_tty - release tty structure memory
+ * @kref: kref of tty we are obliterating
+ *
+ * Releases memory associated with a tty structure, and clears out the
+ * driver table slots. This function is called when a device is no longer
+ * in use. It also gets called when setup of a device fails.
+ *
+ * Locking:
+ * tty_mutex - sometimes only
+ * takes the file list lock internally when working on the list
+ * of ttys that the driver keeps.
+ *
+ * This method gets called from a work queue so that the driver private
+ * cleanup ops can sleep (needed for USB at least)
+ */
+static void release_one_tty(struct work_struct *work)
+{
+ struct tty_struct *tty =
+ container_of(work, struct tty_struct, hangup_work);
+ struct tty_driver *driver = tty->driver;
+
+ if (tty->ops->cleanup)
+ tty->ops->cleanup(tty);
+
+ tty->magic = 0;
+ tty_driver_kref_put(driver);
+ module_put(driver->owner);
+
+ spin_lock(&tty_files_lock);
+ list_del_init(&tty->tty_files);
+ spin_unlock(&tty_files_lock);
+
+ put_pid(tty->pgrp);
+ put_pid(tty->session);
+ free_tty_struct(tty);
+}
+
+static void queue_release_one_tty(struct kref *kref)
+{
+ struct tty_struct *tty = container_of(kref, struct tty_struct, kref);
+
+ if (tty->ops->shutdown)
+ tty->ops->shutdown(tty);
+ else
+ tty_shutdown(tty);
+
+ /* The hangup queue is now free so we can reuse it rather than
+ waste a chunk of memory for each port */
+ INIT_WORK(&tty->hangup_work, release_one_tty);
+ schedule_work(&tty->hangup_work);
+}
+
+/**
+ * tty_kref_put - release a tty kref
+ * @tty: tty device
+ *
+ * Release a reference to a tty device and if need be let the kref
+ * layer destruct the object for us
+ */
+
+void tty_kref_put(struct tty_struct *tty)
+{
+ if (tty)
+ kref_put(&tty->kref, queue_release_one_tty);
+}
+EXPORT_SYMBOL(tty_kref_put);
+
+/**
+ * release_tty - release tty structure memory
+ *
+ * Release both @tty and a possible linked partner (think pty pair),
+ * and decrement the refcount of the backing module.
+ *
+ * Locking:
+ * tty_mutex - sometimes only
+ * takes the file list lock internally when working on the list
+ * of ttys that the driver keeps.
+ * FIXME: should we require tty_mutex is held here ??
+ *
+ */
+static void release_tty(struct tty_struct *tty, int idx)
+{
+ /* This should always be true but check for the moment */
+ WARN_ON(tty->index != idx);
+
+ if (tty->link)
+ tty_kref_put(tty->link);
+ tty_kref_put(tty);
+}
+
+/**
+ * tty_release - vfs callback for close
+ * @inode: inode of tty
+ * @filp: file pointer for handle to tty
+ *
+ * Called the last time each file handle is closed that references
+ * this tty. There may however be several such references.
+ *
+ * Locking:
+ * Takes bkl. See tty_release_dev
+ *
+ * Even releasing the tty structures is a tricky business.. We have
+ * to be very careful that the structures are all released at the
+ * same time, as interrupts might otherwise get the wrong pointers.
+ *
+ * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
+ * lead to double frees or releasing memory still in use.
+ */
+
+int tty_release(struct inode *inode, struct file *filp)
+{
+ struct tty_struct *tty = file_tty(filp);
+ struct tty_struct *o_tty;
+ int pty_master, tty_closing, o_tty_closing, do_sleep;
+ int devpts;
+ int idx;
+ char buf[64];
+
+ if (tty_paranoia_check(tty, inode, "tty_release_dev"))
+ return 0;
+
+ tty_lock();
+ check_tty_count(tty, "tty_release_dev");
+
+ __tty_fasync(-1, filp, 0);
+
+ idx = tty->index;
+ pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_MASTER);
+ devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0;
+ o_tty = tty->link;
+
+#ifdef TTY_PARANOIA_CHECK
+ if (idx < 0 || idx >= tty->driver->num) {
+ printk(KERN_DEBUG "tty_release_dev: bad idx when trying to "
+ "free (%s)\n", tty->name);
+ tty_unlock();
+ return 0;
+ }
+ if (!devpts) {
+ if (tty != tty->driver->ttys[idx]) {
+ tty_unlock();
+ printk(KERN_DEBUG "tty_release_dev: driver.table[%d] not tty "
+ "for (%s)\n", idx, tty->name);
+ return 0;
+ }
+ if (tty->termios != tty->driver->termios[idx]) {
+ tty_unlock();
+ printk(KERN_DEBUG "tty_release_dev: driver.termios[%d] not termios "
+ "for (%s)\n",
+ idx, tty->name);
+ return 0;
+ }
+ }
+#endif
+
+#ifdef TTY_DEBUG_HANGUP
+ printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...",
+ tty_name(tty, buf), tty->count);
+#endif
+
+#ifdef TTY_PARANOIA_CHECK
+ if (tty->driver->other &&
+ !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+ if (o_tty != tty->driver->other->ttys[idx]) {
+ tty_unlock();
+ printk(KERN_DEBUG "tty_release_dev: other->table[%d] "
+ "not o_tty for (%s)\n",
+ idx, tty->name);
+ return 0 ;
+ }
+ if (o_tty->termios != tty->driver->other->termios[idx]) {
+ tty_unlock();
+ printk(KERN_DEBUG "tty_release_dev: other->termios[%d] "
+ "not o_termios for (%s)\n",
+ idx, tty->name);
+ return 0;
+ }
+ if (o_tty->link != tty) {
+ tty_unlock();
+ printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n");
+ return 0;
+ }
+ }
+#endif
+ if (tty->ops->close)
+ tty->ops->close(tty, filp);
+
+ tty_unlock();
+ /*
+ * Sanity check: if tty->count is going to zero, there shouldn't be
+ * any waiters on tty->read_wait or tty->write_wait. We test the
+ * wait queues and kick everyone out _before_ actually starting to
+ * close. This ensures that we won't block while releasing the tty
+ * structure.
+ *
+ * The test for the o_tty closing is necessary, since the master and
+ * slave sides may close in any order. If the slave side closes out
+ * first, its count will be one, since the master side holds an open.
+ * Thus this test wouldn't be triggered at the time the slave closes,
+ * so we do it now.
+ *
+ * Note that it's possible for the tty to be opened again while we're
+ * flushing out waiters. By recalculating the closing flags before
+ * each iteration we avoid any problems.
+ */
+ while (1) {
+ /* Guard against races with tty->count changes elsewhere and
+ opens on /dev/tty */
+
+ mutex_lock(&tty_mutex);
+ tty_lock();
+ tty_closing = tty->count <= 1;
+ o_tty_closing = o_tty &&
+ (o_tty->count <= (pty_master ? 1 : 0));
+ do_sleep = 0;
+
+ if (tty_closing) {
+ if (waitqueue_active(&tty->read_wait)) {
+ wake_up_poll(&tty->read_wait, POLLIN);
+ do_sleep++;
+ }
+ if (waitqueue_active(&tty->write_wait)) {
+ wake_up_poll(&tty->write_wait, POLLOUT);
+ do_sleep++;
+ }
+ }
+ if (o_tty_closing) {
+ if (waitqueue_active(&o_tty->read_wait)) {
+ wake_up_poll(&o_tty->read_wait, POLLIN);
+ do_sleep++;
+ }
+ if (waitqueue_active(&o_tty->write_wait)) {
+ wake_up_poll(&o_tty->write_wait, POLLOUT);
+ do_sleep++;
+ }
+ }
+ if (!do_sleep)
+ break;
+
+ printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue "
+ "active!\n", tty_name(tty, buf));
+ tty_unlock();
+ mutex_unlock(&tty_mutex);
+ schedule();
+ }
+
+ /*
+ * The closing flags are now consistent with the open counts on
+ * both sides, and we've completed the last operation that could
+ * block, so it's safe to proceed with closing.
+ */
+ if (pty_master) {
+ if (--o_tty->count < 0) {
+ printk(KERN_WARNING "tty_release_dev: bad pty slave count "
+ "(%d) for %s\n",
+ o_tty->count, tty_name(o_tty, buf));
+ o_tty->count = 0;
+ }
+ }
+ if (--tty->count < 0) {
+ printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n",
+ tty->count, tty_name(tty, buf));
+ tty->count = 0;
+ }
+
+ /*
+ * We've decremented tty->count, so we need to remove this file
+ * descriptor off the tty->tty_files list; this serves two
+ * purposes:
+ * - check_tty_count sees the correct number of file descriptors
+ * associated with this tty.
+ * - do_tty_hangup no longer sees this file descriptor as
+ * something that needs to be handled for hangups.
+ */
+ tty_del_file(filp);
+
+ /*
+ * Perform some housekeeping before deciding whether to return.
+ *
+ * Set the TTY_CLOSING flag if this was the last open. In the
+ * case of a pty we may have to wait around for the other side
+ * to close, and TTY_CLOSING makes sure we can't be reopened.
+ */
+ if (tty_closing)
+ set_bit(TTY_CLOSING, &tty->flags);
+ if (o_tty_closing)
+ set_bit(TTY_CLOSING, &o_tty->flags);
+
+ /*
+ * If _either_ side is closing, make sure there aren't any
+ * processes that still think tty or o_tty is their controlling
+ * tty.
+ */
+ if (tty_closing || o_tty_closing) {
+ read_lock(&tasklist_lock);
+ session_clear_tty(tty->session);
+ if (o_tty)
+ session_clear_tty(o_tty->session);
+ read_unlock(&tasklist_lock);
+ }
+
+ mutex_unlock(&tty_mutex);
+
+ /* check whether both sides are closing ... */
+ if (!tty_closing || (o_tty && !o_tty_closing)) {
+ tty_unlock();
+ return 0;
+ }
+
+#ifdef TTY_DEBUG_HANGUP
+ printk(KERN_DEBUG "freeing tty structure...");
+#endif
+ /*
+ * Ask the line discipline code to release its structures
+ */
+ tty_ldisc_release(tty, o_tty);
+ /*
+ * The release_tty function takes care of the details of clearing
+ * the slots and preserving the termios structure.
+ */
+ release_tty(tty, idx);
+
+ /* Make this pty number available for reallocation */
+ if (devpts)
+ devpts_kill_index(inode, idx);
+ tty_unlock();
+ return 0;
+}
+
+/**
+ * tty_open - open a tty device
+ * @inode: inode of device file
+ * @filp: file pointer to tty
+ *
+ * tty_open and tty_release keep up the tty count that contains the
+ * number of opens done on a tty. We cannot use the inode-count, as
+ * different inodes might point to the same tty.
+ *
+ * Open-counting is needed for pty masters, as well as for keeping
+ * track of serial lines: DTR is dropped when the last close happens.
+ * (This is not done solely through tty->count, now. - Ted 1/27/92)
+ *
+ * The termios state of a pty is reset on first open so that
+ * settings don't persist across reuse.
+ *
+ * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work.
+ * tty->count should protect the rest.
+ * ->siglock protects ->signal/->sighand
+ */
+
+static int tty_open(struct inode *inode, struct file *filp)
+{
+ struct tty_struct *tty = NULL;
+ int noctty, retval;
+ struct tty_driver *driver;
+ int index;
+ dev_t device = inode->i_rdev;
+ unsigned saved_flags = filp->f_flags;
+
+ nonseekable_open(inode, filp);
+
+retry_open:
+ noctty = filp->f_flags & O_NOCTTY;
+ index = -1;
+ retval = 0;
+
+ mutex_lock(&tty_mutex);
+ tty_lock();
+
+ if (device == MKDEV(TTYAUX_MAJOR, 0)) {
+ tty = get_current_tty();
+ if (!tty) {
+ tty_unlock();
+ mutex_unlock(&tty_mutex);
+ return -ENXIO;
+ }
+ driver = tty_driver_kref_get(tty->driver);
+ index = tty->index;
+ filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
+ /* noctty = 1; */
+ /* FIXME: Should we take a driver reference ? */
+ tty_kref_put(tty);
+ goto got_driver;
+ }
+#ifdef CONFIG_VT
+ if (device == MKDEV(TTY_MAJOR, 0)) {
+ extern struct tty_driver *console_driver;
+ driver = tty_driver_kref_get(console_driver);
+ index = fg_console;
+ noctty = 1;
+ goto got_driver;
+ }
+#endif
+ if (device == MKDEV(TTYAUX_MAJOR, 1)) {
+ struct tty_driver *console_driver = console_device(&index);
+ if (console_driver) {
+ driver = tty_driver_kref_get(console_driver);
+ if (driver) {
+ /* Don't let /dev/console block */
+ filp->f_flags |= O_NONBLOCK;
+ noctty = 1;
+ goto got_driver;
+ }
+ }
+ tty_unlock();
+ mutex_unlock(&tty_mutex);
+ return -ENODEV;
+ }
+
+ driver = get_tty_driver(device, &index);
+ if (!driver) {
+ tty_unlock();
+ mutex_unlock(&tty_mutex);
+ return -ENODEV;
+ }
+got_driver:
+ if (!tty) {
+ /* check whether we're reopening an existing tty */
+ tty = tty_driver_lookup_tty(driver, inode, index);
+
+ if (IS_ERR(tty)) {
+ tty_unlock();
+ mutex_unlock(&tty_mutex);
+ return PTR_ERR(tty);
+ }
+ }
+
+ if (tty) {
+ retval = tty_reopen(tty);
+ if (retval)
+ tty = ERR_PTR(retval);
+ } else
+ tty = tty_init_dev(driver, index, 0);
+
+ mutex_unlock(&tty_mutex);
+ tty_driver_kref_put(driver);
+ if (IS_ERR(tty)) {
+ tty_unlock();
+ return PTR_ERR(tty);
+ }
+
+ retval = tty_add_file(tty, filp);
+ if (retval) {
+ tty_unlock();
+ return retval;
+ }
+
+ check_tty_count(tty, "tty_open");
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_MASTER)
+ noctty = 1;
+#ifdef TTY_DEBUG_HANGUP
+ printk(KERN_DEBUG "opening %s...", tty->name);
+#endif
+ if (!retval) {
+ if (tty->ops->open)
+ retval = tty->ops->open(tty, filp);
+ else
+ retval = -ENODEV;
+ }
+ filp->f_flags = saved_flags;
+
+ if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) &&
+ !capable(CAP_SYS_ADMIN))
+ retval = -EBUSY;
+
+ if (retval) {
+#ifdef TTY_DEBUG_HANGUP
+ printk(KERN_DEBUG "error %d in opening %s...", retval,
+ tty->name);
+#endif
+ tty_unlock(); /* need to call tty_release without BTM */
+ tty_release(inode, filp);
+ if (retval != -ERESTARTSYS)
+ return retval;
+
+ if (signal_pending(current))
+ return retval;
+
+ schedule();
+ /*
+ * Need to reset f_op in case a hangup happened.
+ */
+ tty_lock();
+ if (filp->f_op == &hung_up_tty_fops)
+ filp->f_op = &tty_fops;
+ tty_unlock();
+ goto retry_open;
+ }
+ tty_unlock();
+
+
+ mutex_lock(&tty_mutex);
+ tty_lock();
+ spin_lock_irq(¤t->sighand->siglock);
+ if (!noctty &&
+ current->signal->leader &&
+ !current->signal->tty &&
+ tty->session == NULL)
+ __proc_set_tty(current, tty);
+ spin_unlock_irq(¤t->sighand->siglock);
+ tty_unlock();
+ mutex_unlock(&tty_mutex);
+ return 0;
+}
+
+
+
+/**
+ * tty_poll - check tty status
+ * @filp: file being polled
+ * @wait: poll wait structures to update
+ *
+ * Call the line discipline polling method to obtain the poll
+ * status of the device.
+ *
+ * Locking: locks called line discipline but ldisc poll method
+ * may be re-entered freely by other callers.
+ */
+
+static unsigned int tty_poll(struct file *filp, poll_table *wait)
+{
+ struct tty_struct *tty = file_tty(filp);
+ struct tty_ldisc *ld;
+ int ret = 0;
+
+ if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll"))
+ return 0;
+
+ ld = tty_ldisc_ref_wait(tty);
+ if (ld->ops->poll)
+ ret = (ld->ops->poll)(tty, filp, wait);
+ tty_ldisc_deref(ld);
+ return ret;
+}
+
+static int __tty_fasync(int fd, struct file *filp, int on)
+{
+ struct tty_struct *tty = file_tty(filp);
+ unsigned long flags;
+ int retval = 0;
+
+ if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync"))
+ goto out;
+
+ retval = fasync_helper(fd, filp, on, &tty->fasync);
+ if (retval <= 0)
+ goto out;
+
+ if (on) {
+ enum pid_type type;
+ struct pid *pid;
+ if (!waitqueue_active(&tty->read_wait))
+ tty->minimum_to_wake = 1;
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ if (tty->pgrp) {
+ pid = tty->pgrp;
+ type = PIDTYPE_PGID;
+ } else {
+ pid = task_pid(current);
+ type = PIDTYPE_PID;
+ }
+ get_pid(pid);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ retval = __f_setown(filp, pid, type, 0);
+ put_pid(pid);
+ if (retval)
+ goto out;
+ } else {
+ if (!tty->fasync && !waitqueue_active(&tty->read_wait))
+ tty->minimum_to_wake = N_TTY_BUF_SIZE;
+ }
+ retval = 0;
+out:
+ return retval;
+}
+
+static int tty_fasync(int fd, struct file *filp, int on)
+{
+ int retval;
+ tty_lock();
+ retval = __tty_fasync(fd, filp, on);
+ tty_unlock();
+ return retval;
+}
+
+/**
+ * tiocsti - fake input character
+ * @tty: tty to fake input into
+ * @p: pointer to character
+ *
+ * Fake input to a tty device. Does the necessary locking and
+ * input management.
+ *
+ * FIXME: does not honour flow control ??
+ *
+ * Locking:
+ * Called functions take tty_ldisc_lock
+ * current->signal->tty check is safe without locks
+ *
+ * FIXME: may race normal receive processing
+ */
+
+static int tiocsti(struct tty_struct *tty, char __user *p)
+{
+ char ch, mbz = 0;
+ struct tty_ldisc *ld;
+
+ if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (get_user(ch, p))
+ return -EFAULT;
+ tty_audit_tiocsti(tty, ch);
+ ld = tty_ldisc_ref_wait(tty);
+ ld->ops->receive_buf(tty, &ch, &mbz, 1);
+ tty_ldisc_deref(ld);
+ return 0;
+}
+
+/**
+ * tiocgwinsz - implement window query ioctl
+ * @tty; tty
+ * @arg: user buffer for result
+ *
+ * Copies the kernel idea of the window size into the user buffer.
+ *
+ * Locking: tty->termios_mutex is taken to ensure the winsize data
+ * is consistent.
+ */
+
+static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
+{
+ int err;
+
+ mutex_lock(&tty->termios_mutex);
+ err = copy_to_user(arg, &tty->winsize, sizeof(*arg));
+ mutex_unlock(&tty->termios_mutex);
+
+ return err ? -EFAULT: 0;
+}
+
+/**
+ * tty_do_resize - resize event
+ * @tty: tty being resized
+ * @rows: rows (character)
+ * @cols: cols (character)
+ *
+ * Update the termios variables and send the necessary signals to
+ * peform a terminal resize correctly
+ */
+
+int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
+{
+ struct pid *pgrp;
+ unsigned long flags;
+
+ /* Lock the tty */
+ mutex_lock(&tty->termios_mutex);
+ if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
+ goto done;
+ /* Get the PID values and reference them so we can
+ avoid holding the tty ctrl lock while sending signals */
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ pgrp = get_pid(tty->pgrp);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+ if (pgrp)
+ kill_pgrp(pgrp, SIGWINCH, 1);
+ put_pid(pgrp);
+
+ tty->winsize = *ws;
+done:
+ mutex_unlock(&tty->termios_mutex);
+ return 0;
+}
+
+/**
+ * tiocswinsz - implement window size set ioctl
+ * @tty; tty side of tty
+ * @arg: user buffer for result
+ *
+ * Copies the user idea of the window size to the kernel. Traditionally
+ * this is just advisory information but for the Linux console it
+ * actually has driver level meaning and triggers a VC resize.
+ *
+ * Locking:
+ * Driver dependant. The default do_resize method takes the
+ * tty termios mutex and ctrl_lock. The console takes its own lock
+ * then calls into the default method.
+ */
+
+static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg)
+{
+ struct winsize tmp_ws;
+ if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
+ return -EFAULT;
+
+ if (tty->ops->resize)
+ return tty->ops->resize(tty, &tmp_ws);
+ else
+ return tty_do_resize(tty, &tmp_ws);
+}
+
+/**
+ * tioccons - allow admin to move logical console
+ * @file: the file to become console
+ *
+ * Allow the adminstrator to move the redirected console device
+ *
+ * Locking: uses redirect_lock to guard the redirect information
+ */
+
+static int tioccons(struct file *file)
+{
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (file->f_op->write == redirected_tty_write) {
+ struct file *f;
+ spin_lock(&redirect_lock);
+ f = redirect;
+ redirect = NULL;
+ spin_unlock(&redirect_lock);
+ if (f)
+ fput(f);
+ return 0;
+ }
+ spin_lock(&redirect_lock);
+ if (redirect) {
+ spin_unlock(&redirect_lock);
+ return -EBUSY;
+ }
+ get_file(file);
+ redirect = file;
+ spin_unlock(&redirect_lock);
+ return 0;
+}
+
+/**
+ * fionbio - non blocking ioctl
+ * @file: file to set blocking value
+ * @p: user parameter
+ *
+ * Historical tty interfaces had a blocking control ioctl before
+ * the generic functionality existed. This piece of history is preserved
+ * in the expected tty API of posix OS's.
+ *
+ * Locking: none, the open file handle ensures it won't go away.
+ */
+
+static int fionbio(struct file *file, int __user *p)
+{
+ int nonblock;
+
+ if (get_user(nonblock, p))
+ return -EFAULT;
+
+ spin_lock(&file->f_lock);
+ if (nonblock)
+ file->f_flags |= O_NONBLOCK;
+ else
+ file->f_flags &= ~O_NONBLOCK;
+ spin_unlock(&file->f_lock);
+ return 0;
+}
+
+/**
+ * tiocsctty - set controlling tty
+ * @tty: tty structure
+ * @arg: user argument
+ *
+ * This ioctl is used to manage job control. It permits a session
+ * leader to set this tty as the controlling tty for the session.
+ *
+ * Locking:
+ * Takes tty_mutex() to protect tty instance
+ * Takes tasklist_lock internally to walk sessions
+ * Takes ->siglock() when updating signal->tty
+ */
+
+static int tiocsctty(struct tty_struct *tty, int arg)
+{
+ int ret = 0;
+ if (current->signal->leader && (task_session(current) == tty->session))
+ return ret;
+
+ mutex_lock(&tty_mutex);
+ /*
+ * The process must be a session leader and
+ * not have a controlling tty already.
+ */
+ if (!current->signal->leader || current->signal->tty) {
+ ret = -EPERM;
+ goto unlock;
+ }
+
+ if (tty->session) {
+ /*
+ * This tty is already the controlling
+ * tty for another session group!
+ */
+ if (arg == 1 && capable(CAP_SYS_ADMIN)) {
+ /*
+ * Steal it away
+ */
+ read_lock(&tasklist_lock);
+ session_clear_tty(tty->session);
+ read_unlock(&tasklist_lock);
+ } else {
+ ret = -EPERM;
+ goto unlock;
+ }
+ }
+ proc_set_tty(current, tty);
+unlock:
+ mutex_unlock(&tty_mutex);
+ return ret;
+}
+
+/**
+ * tty_get_pgrp - return a ref counted pgrp pid
+ * @tty: tty to read
+ *
+ * Returns a refcounted instance of the pid struct for the process
+ * group controlling the tty.
+ */
+
+struct pid *tty_get_pgrp(struct tty_struct *tty)
+{
+ unsigned long flags;
+ struct pid *pgrp;
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ pgrp = get_pid(tty->pgrp);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+ return pgrp;
+}
+EXPORT_SYMBOL_GPL(tty_get_pgrp);
+
+/**
+ * tiocgpgrp - get process group
+ * @tty: tty passed by user
+ * @real_tty: tty side of the tty pased by the user if a pty else the tty
+ * @p: returned pid
+ *
+ * Obtain the process group of the tty. If there is no process group
+ * return an error.
+ *
+ * Locking: none. Reference to current->signal->tty is safe.
+ */
+
+static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+ struct pid *pid;
+ int ret;
+ /*
+ * (tty == real_tty) is a cheap way of
+ * testing if the tty is NOT a master pty.
+ */
+ if (tty == real_tty && current->signal->tty != real_tty)
+ return -ENOTTY;
+ pid = tty_get_pgrp(real_tty);
+ ret = put_user(pid_vnr(pid), p);
+ put_pid(pid);
+ return ret;
+}
+
+/**
+ * tiocspgrp - attempt to set process group
+ * @tty: tty passed by user
+ * @real_tty: tty side device matching tty passed by user
+ * @p: pid pointer
+ *
+ * Set the process group of the tty to the session passed. Only
+ * permitted where the tty session is our session.
+ *
+ * Locking: RCU, ctrl lock
+ */
+
+static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+ struct pid *pgrp;
+ pid_t pgrp_nr;
+ int retval = tty_check_change(real_tty);
+ unsigned long flags;
+
+ if (retval == -EIO)
+ return -ENOTTY;
+ if (retval)
+ return retval;
+ if (!current->signal->tty ||
+ (current->signal->tty != real_tty) ||
+ (real_tty->session != task_session(current)))
+ return -ENOTTY;
+ if (get_user(pgrp_nr, p))
+ return -EFAULT;
+ if (pgrp_nr < 0)
+ return -EINVAL;
+ rcu_read_lock();
+ pgrp = find_vpid(pgrp_nr);
+ retval = -ESRCH;
+ if (!pgrp)
+ goto out_unlock;
+ retval = -EPERM;
+ if (session_of_pgrp(pgrp) != task_session(current))
+ goto out_unlock;
+ retval = 0;
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ put_pid(real_tty->pgrp);
+ real_tty->pgrp = get_pid(pgrp);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+out_unlock:
+ rcu_read_unlock();
+ return retval;
+}
+
+/**
+ * tiocgsid - get session id
+ * @tty: tty passed by user
+ * @real_tty: tty side of the tty pased by the user if a pty else the tty
+ * @p: pointer to returned session id
+ *
+ * Obtain the session id of the tty. If there is no session
+ * return an error.
+ *
+ * Locking: none. Reference to current->signal->tty is safe.
+ */
+
+static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+ /*
+ * (tty == real_tty) is a cheap way of
+ * testing if the tty is NOT a master pty.
+ */
+ if (tty == real_tty && current->signal->tty != real_tty)
+ return -ENOTTY;
+ if (!real_tty->session)
+ return -ENOTTY;
+ return put_user(pid_vnr(real_tty->session), p);
+}
+
+/**
+ * tiocsetd - set line discipline
+ * @tty: tty device
+ * @p: pointer to user data
+ *
+ * Set the line discipline according to user request.
+ *
+ * Locking: see tty_set_ldisc, this function is just a helper
+ */
+
+static int tiocsetd(struct tty_struct *tty, int __user *p)
+{
+ int ldisc;
+ int ret;
+
+ if (get_user(ldisc, p))
+ return -EFAULT;
+
+ ret = tty_set_ldisc(tty, ldisc);
+
+ return ret;
+}
+
+/**
+ * send_break - performed time break
+ * @tty: device to break on
+ * @duration: timeout in mS
+ *
+ * Perform a timed break on hardware that lacks its own driver level
+ * timed break functionality.
+ *
+ * Locking:
+ * atomic_write_lock serializes
+ *
+ */
+
+static int send_break(struct tty_struct *tty, unsigned int duration)
+{
+ int retval;
+
+ if (tty->ops->break_ctl == NULL)
+ return 0;
+
+ if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
+ retval = tty->ops->break_ctl(tty, duration);
+ else {
+ /* Do the work ourselves */
+ if (tty_write_lock(tty, 0) < 0)
+ return -EINTR;
+ retval = tty->ops->break_ctl(tty, -1);
+ if (retval)
+ goto out;
+ if (!signal_pending(current))
+ msleep_interruptible(duration);
+ retval = tty->ops->break_ctl(tty, 0);
+out:
+ tty_write_unlock(tty);
+ if (signal_pending(current))
+ retval = -EINTR;
+ }
+ return retval;
+}
+
+/**
+ * tty_tiocmget - get modem status
+ * @tty: tty device
+ * @file: user file pointer
+ * @p: pointer to result
+ *
+ * Obtain the modem status bits from the tty driver if the feature
+ * is supported. Return -EINVAL if it is not available.
+ *
+ * Locking: none (up to the driver)
+ */
+
+static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p)
+{
+ int retval = -EINVAL;
+
+ if (tty->ops->tiocmget) {
+ retval = tty->ops->tiocmget(tty, file);
+
+ if (retval >= 0)
+ retval = put_user(retval, p);
+ }
+ return retval;
+}
+
+/**
+ * tty_tiocmset - set modem status
+ * @tty: tty device
+ * @file: user file pointer
+ * @cmd: command - clear bits, set bits or set all
+ * @p: pointer to desired bits
+ *
+ * Set the modem status bits from the tty driver if the feature
+ * is supported. Return -EINVAL if it is not available.
+ *
+ * Locking: none (up to the driver)
+ */
+
+static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd,
+ unsigned __user *p)
+{
+ int retval;
+ unsigned int set, clear, val;
+
+ if (tty->ops->tiocmset == NULL)
+ return -EINVAL;
+
+ retval = get_user(val, p);
+ if (retval)
+ return retval;
+ set = clear = 0;
+ switch (cmd) {
+ case TIOCMBIS:
+ set = val;
+ break;
+ case TIOCMBIC:
+ clear = val;
+ break;
+ case TIOCMSET:
+ set = val;
+ clear = ~val;
+ break;
+ }
+ set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+ clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+ return tty->ops->tiocmset(tty, file, set, clear);
+}
+
+static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
+{
+ int retval = -EINVAL;
+ struct serial_icounter_struct icount;
+ memset(&icount, 0, sizeof(icount));
+ if (tty->ops->get_icount)
+ retval = tty->ops->get_icount(tty, &icount);
+ if (retval != 0)
+ return retval;
+ if (copy_to_user(arg, &icount, sizeof(icount)))
+ return -EFAULT;
+ return 0;
+}
+
+struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
+{
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_MASTER)
+ tty = tty->link;
+ return tty;
+}
+EXPORT_SYMBOL(tty_pair_get_tty);
+
+struct tty_struct *tty_pair_get_pty(struct tty_struct *tty)
+{
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_MASTER)
+ return tty;
+ return tty->link;
+}
+EXPORT_SYMBOL(tty_pair_get_pty);
+
+/*
+ * Split this up, as gcc can choke on it otherwise..
+ */
+long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct tty_struct *tty = file_tty(file);
+ struct tty_struct *real_tty;
+ void __user *p = (void __user *)arg;
+ int retval;
+ struct tty_ldisc *ld;
+ struct inode *inode = file->f_dentry->d_inode;
+
+ if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+ return -EINVAL;
+
+ real_tty = tty_pair_get_tty(tty);
+
+ /*
+ * Factor out some common prep work
+ */
+ switch (cmd) {
+ case TIOCSETD:
+ case TIOCSBRK:
+ case TIOCCBRK:
+ case TCSBRK:
+ case TCSBRKP:
+ retval = tty_check_change(tty);
+ if (retval)
+ return retval;
+ if (cmd != TIOCCBRK) {
+ tty_wait_until_sent(tty, 0);
+ if (signal_pending(current))
+ return -EINTR;
+ }
+ break;
+ }
+
+ /*
+ * Now do the stuff.
+ */
+ switch (cmd) {
+ case TIOCSTI:
+ return tiocsti(tty, p);
+ case TIOCGWINSZ:
+ return tiocgwinsz(real_tty, p);
+ case TIOCSWINSZ:
+ return tiocswinsz(real_tty, p);
+ case TIOCCONS:
+ return real_tty != tty ? -EINVAL : tioccons(file);
+ case FIONBIO:
+ return fionbio(file, p);
+ case TIOCEXCL:
+ set_bit(TTY_EXCLUSIVE, &tty->flags);
+ return 0;
+ case TIOCNXCL:
+ clear_bit(TTY_EXCLUSIVE, &tty->flags);
+ return 0;
+ case TIOCNOTTY:
+ if (current->signal->tty != tty)
+ return -ENOTTY;
+ no_tty();
+ return 0;
+ case TIOCSCTTY:
+ return tiocsctty(tty, arg);
+ case TIOCGPGRP:
+ return tiocgpgrp(tty, real_tty, p);
+ case TIOCSPGRP:
+ return tiocspgrp(tty, real_tty, p);
+ case TIOCGSID:
+ return tiocgsid(tty, real_tty, p);
+ case TIOCGETD:
+ return put_user(tty->ldisc->ops->num, (int __user *)p);
+ case TIOCSETD:
+ return tiocsetd(tty, p);
+ /*
+ * Break handling
+ */
+ case TIOCSBRK: /* Turn break on, unconditionally */
+ if (tty->ops->break_ctl)
+ return tty->ops->break_ctl(tty, -1);
+ return 0;
+ case TIOCCBRK: /* Turn break off, unconditionally */
+ if (tty->ops->break_ctl)
+ return tty->ops->break_ctl(tty, 0);
+ return 0;
+ case TCSBRK: /* SVID version: non-zero arg --> no break */
+ /* non-zero arg means wait for all output data
+ * to be sent (performed above) but don't send break.
+ * This is used by the tcdrain() termios function.
+ */
+ if (!arg)
+ return send_break(tty, 250);
+ return 0;
+ case TCSBRKP: /* support for POSIX tcsendbreak() */
+ return send_break(tty, arg ? arg*100 : 250);
+
+ case TIOCMGET:
+ return tty_tiocmget(tty, file, p);
+ case TIOCMSET:
+ case TIOCMBIC:
+ case TIOCMBIS:
+ return tty_tiocmset(tty, file, cmd, p);
+ case TIOCGICOUNT:
+ retval = tty_tiocgicount(tty, p);
+ /* For the moment allow fall through to the old method */
+ if (retval != -EINVAL)
+ return retval;
+ break;
+ case TCFLSH:
+ switch (arg) {
+ case TCIFLUSH:
+ case TCIOFLUSH:
+ /* flush tty buffer and allow ldisc to process ioctl */
+ tty_buffer_flush(tty);
+ break;
+ }
+ break;
+ }
+ if (tty->ops->ioctl) {
+ retval = (tty->ops->ioctl)(tty, file, cmd, arg);
+ if (retval != -ENOIOCTLCMD)
+ return retval;
+ }
+ ld = tty_ldisc_ref_wait(tty);
+ retval = -EINVAL;
+ if (ld->ops->ioctl) {
+ retval = ld->ops->ioctl(tty, file, cmd, arg);
+ if (retval == -ENOIOCTLCMD)
+ retval = -EINVAL;
+ }
+ tty_ldisc_deref(ld);
+ return retval;
+}
+
+#ifdef CONFIG_COMPAT
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct tty_struct *tty = file_tty(file);
+ struct tty_ldisc *ld;
+ int retval = -ENOIOCTLCMD;
+
+ if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+ return -EINVAL;
+
+ if (tty->ops->compat_ioctl) {
+ retval = (tty->ops->compat_ioctl)(tty, file, cmd, arg);
+ if (retval != -ENOIOCTLCMD)
+ return retval;
+ }
+
+ ld = tty_ldisc_ref_wait(tty);
+ if (ld->ops->compat_ioctl)
+ retval = ld->ops->compat_ioctl(tty, file, cmd, arg);
+ tty_ldisc_deref(ld);
+
+ return retval;
+}
+#endif
+
+/*
+ * This implements the "Secure Attention Key" --- the idea is to
+ * prevent trojan horses by killing all processes associated with this
+ * tty when the user hits the "Secure Attention Key". Required for
+ * super-paranoid applications --- see the Orange Book for more details.
+ *
+ * This code could be nicer; ideally it should send a HUP, wait a few
+ * seconds, then send a INT, and then a KILL signal. But you then
+ * have to coordinate with the init process, since all processes associated
+ * with the current tty must be dead before the new getty is allowed
+ * to spawn.
+ *
+ * Now, if it would be correct ;-/ The current code has a nasty hole -
+ * it doesn't catch files in flight. We may send the descriptor to ourselves
+ * via AF_UNIX socket, close it and later fetch from socket. FIXME.
+ *
+ * Nasty bug: do_SAK is being called in interrupt context. This can
+ * deadlock. We punt it up to process context. AKPM - 16Mar2001
+ */
+void __do_SAK(struct tty_struct *tty)
+{
+#ifdef TTY_SOFT_SAK
+ tty_hangup(tty);
+#else
+ struct task_struct *g, *p;
+ struct pid *session;
+ int i;
+ struct file *filp;
+ struct fdtable *fdt;
+
+ if (!tty)
+ return;
+ session = tty->session;
+
+ tty_ldisc_flush(tty);
+
+ tty_driver_flush_buffer(tty);
+
+ read_lock(&tasklist_lock);
+ /* Kill the entire session */
+ do_each_pid_task(session, PIDTYPE_SID, p) {
+ printk(KERN_NOTICE "SAK: killed process %d"
+ " (%s): task_session(p)==tty->session\n",
+ task_pid_nr(p), p->comm);
+ send_sig(SIGKILL, p, 1);
+ } while_each_pid_task(session, PIDTYPE_SID, p);
+ /* Now kill any processes that happen to have the
+ * tty open.
+ */
+ do_each_thread(g, p) {
+ if (p->signal->tty == tty) {
+ printk(KERN_NOTICE "SAK: killed process %d"
+ " (%s): task_session(p)==tty->session\n",
+ task_pid_nr(p), p->comm);
+ send_sig(SIGKILL, p, 1);
+ continue;
+ }
+ task_lock(p);
+ if (p->files) {
+ /*
+ * We don't take a ref to the file, so we must
+ * hold ->file_lock instead.
+ */
+ spin_lock(&p->files->file_lock);
+ fdt = files_fdtable(p->files);
+ for (i = 0; i < fdt->max_fds; i++) {
+ filp = fcheck_files(p->files, i);
+ if (!filp)
+ continue;
+ if (filp->f_op->read == tty_read &&
+ file_tty(filp) == tty) {
+ printk(KERN_NOTICE "SAK: killed process %d"
+ " (%s): fd#%d opened to the tty\n",
+ task_pid_nr(p), p->comm, i);
+ force_sig(SIGKILL, p);
+ break;
+ }
+ }
+ spin_unlock(&p->files->file_lock);
+ }
+ task_unlock(p);
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+#endif
+}
+
+static void do_SAK_work(struct work_struct *work)
+{
+ struct tty_struct *tty =
+ container_of(work, struct tty_struct, SAK_work);
+ __do_SAK(tty);
+}
+
+/*
+ * The tq handling here is a little racy - tty->SAK_work may already be queued.
+ * Fortunately we don't need to worry, because if ->SAK_work is already queued,
+ * the values which we write to it will be identical to the values which it
+ * already has. --akpm
+ */
+void do_SAK(struct tty_struct *tty)
+{
+ if (!tty)
+ return;
+ schedule_work(&tty->SAK_work);
+}
+
+EXPORT_SYMBOL(do_SAK);
+
+static int dev_match_devt(struct device *dev, void *data)
+{
+ dev_t *devt = data;
+ return dev->devt == *devt;
+}
+
+/* Must put_device() after it's unused! */
+static struct device *tty_get_device(struct tty_struct *tty)
+{
+ dev_t devt = tty_devnum(tty);
+ return class_find_device(tty_class, NULL, &devt, dev_match_devt);
+}
+
+
+/**
+ * initialize_tty_struct
+ * @tty: tty to initialize
+ *
+ * This subroutine initializes a tty structure that has been newly
+ * allocated.
+ *
+ * Locking: none - tty in question must not be exposed at this point
+ */
+
+void initialize_tty_struct(struct tty_struct *tty,
+ struct tty_driver *driver, int idx)
+{
+ memset(tty, 0, sizeof(struct tty_struct));
+ kref_init(&tty->kref);
+ tty->magic = TTY_MAGIC;
+ tty_ldisc_init(tty);
+ tty->session = NULL;
+ tty->pgrp = NULL;
+ tty->overrun_time = jiffies;
+ tty->buf.head = tty->buf.tail = NULL;
+ tty_buffer_init(tty);
+ mutex_init(&tty->termios_mutex);
+ mutex_init(&tty->ldisc_mutex);
+ init_waitqueue_head(&tty->write_wait);
+ init_waitqueue_head(&tty->read_wait);
+ INIT_WORK(&tty->hangup_work, do_tty_hangup);
+ mutex_init(&tty->atomic_read_lock);
+ mutex_init(&tty->atomic_write_lock);
+ mutex_init(&tty->output_lock);
+ mutex_init(&tty->echo_lock);
+ spin_lock_init(&tty->read_lock);
+ spin_lock_init(&tty->ctrl_lock);
+ INIT_LIST_HEAD(&tty->tty_files);
+ INIT_WORK(&tty->SAK_work, do_SAK_work);
+
+ tty->driver = driver;
+ tty->ops = driver->ops;
+ tty->index = idx;
+ tty_line_name(driver, idx, tty->name);
+ tty->dev = tty_get_device(tty);
+}
+
+/**
+ * tty_put_char - write one character to a tty
+ * @tty: tty
+ * @ch: character
+ *
+ * Write one byte to the tty using the provided put_char method
+ * if present. Returns the number of characters successfully output.
+ *
+ * Note: the specific put_char operation in the driver layer may go
+ * away soon. Don't call it directly, use this method
+ */
+
+int tty_put_char(struct tty_struct *tty, unsigned char ch)
+{
+ if (tty->ops->put_char)
+ return tty->ops->put_char(tty, ch);
+ return tty->ops->write(tty, &ch, 1);
+}
+EXPORT_SYMBOL_GPL(tty_put_char);
+
+struct class *tty_class;
+
+/**
+ * tty_register_device - register a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ * @device: a struct device that is associated with this tty device.
+ * This field is optional, if there is no known struct device
+ * for this tty device it can be set to NULL safely.
+ *
+ * Returns a pointer to the struct device for this tty device
+ * (or ERR_PTR(-EFOO) on error).
+ *
+ * This call is required to be made to register an individual tty device
+ * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
+ * that bit is not set, this function should not be called by a tty
+ * driver.
+ *
+ * Locking: ??
+ */
+
+struct device *tty_register_device(struct tty_driver *driver, unsigned index,
+ struct device *device)
+{
+ char name[64];
+ dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
+
+ if (index >= driver->num) {
+ printk(KERN_ERR "Attempt to register invalid tty line number "
+ " (%d).\n", index);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (driver->type == TTY_DRIVER_TYPE_PTY)
+ pty_line_name(driver, index, name);
+ else
+ tty_line_name(driver, index, name);
+
+ return device_create(tty_class, device, dev, NULL, name);
+}
+EXPORT_SYMBOL(tty_register_device);
+
+/**
+ * tty_unregister_device - unregister a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ *
+ * If a tty device is registered with a call to tty_register_device() then
+ * this function must be called when the tty device is gone.
+ *
+ * Locking: ??
+ */
+
+void tty_unregister_device(struct tty_driver *driver, unsigned index)
+{
+ device_destroy(tty_class,
+ MKDEV(driver->major, driver->minor_start) + index);
+}
+EXPORT_SYMBOL(tty_unregister_device);
+
+struct tty_driver *alloc_tty_driver(int lines)
+{
+ struct tty_driver *driver;
+
+ driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL);
+ if (driver) {
+ kref_init(&driver->kref);
+ driver->magic = TTY_DRIVER_MAGIC;
+ driver->num = lines;
+ /* later we'll move allocation of tables here */
+ }
+ return driver;
+}
+EXPORT_SYMBOL(alloc_tty_driver);
+
+static void destruct_tty_driver(struct kref *kref)
+{
+ struct tty_driver *driver = container_of(kref, struct tty_driver, kref);
+ int i;
+ struct ktermios *tp;
+ void *p;
+
+ if (driver->flags & TTY_DRIVER_INSTALLED) {
+ /*
+ * Free the termios and termios_locked structures because
+ * we don't want to get memory leaks when modular tty
+ * drivers are removed from the kernel.
+ */
+ for (i = 0; i < driver->num; i++) {
+ tp = driver->termios[i];
+ if (tp) {
+ driver->termios[i] = NULL;
+ kfree(tp);
+ }
+ if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV))
+ tty_unregister_device(driver, i);
+ }
+ p = driver->ttys;
+ proc_tty_unregister_driver(driver);
+ driver->ttys = NULL;
+ driver->termios = NULL;
+ kfree(p);
+ cdev_del(&driver->cdev);
+ }
+ kfree(driver);
+}
+
+void tty_driver_kref_put(struct tty_driver *driver)
+{
+ kref_put(&driver->kref, destruct_tty_driver);
+}
+EXPORT_SYMBOL(tty_driver_kref_put);
+
+void tty_set_operations(struct tty_driver *driver,
+ const struct tty_operations *op)
+{
+ driver->ops = op;
+};
+EXPORT_SYMBOL(tty_set_operations);
+
+void put_tty_driver(struct tty_driver *d)
+{
+ tty_driver_kref_put(d);
+}
+EXPORT_SYMBOL(put_tty_driver);
+
+/*
+ * Called by a tty driver to register itself.
+ */
+int tty_register_driver(struct tty_driver *driver)
+{
+ int error;
+ int i;
+ dev_t dev;
+ void **p = NULL;
+ struct device *d;
+
+ if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
+ p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ }
+
+ if (!driver->major) {
+ error = alloc_chrdev_region(&dev, driver->minor_start,
+ driver->num, driver->name);
+ if (!error) {
+ driver->major = MAJOR(dev);
+ driver->minor_start = MINOR(dev);
+ }
+ } else {
+ dev = MKDEV(driver->major, driver->minor_start);
+ error = register_chrdev_region(dev, driver->num, driver->name);
+ }
+ if (error < 0) {
+ kfree(p);
+ return error;
+ }
+
+ if (p) {
+ driver->ttys = (struct tty_struct **)p;
+ driver->termios = (struct ktermios **)(p + driver->num);
+ } else {
+ driver->ttys = NULL;
+ driver->termios = NULL;
+ }
+
+ cdev_init(&driver->cdev, &tty_fops);
+ driver->cdev.owner = driver->owner;
+ error = cdev_add(&driver->cdev, dev, driver->num);
+ if (error) {
+ unregister_chrdev_region(dev, driver->num);
+ driver->ttys = NULL;
+ driver->termios = NULL;
+ kfree(p);
+ return error;
+ }
+
+ mutex_lock(&tty_mutex);
+ list_add(&driver->tty_drivers, &tty_drivers);
+ mutex_unlock(&tty_mutex);
+
+ if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) {
+ for (i = 0; i < driver->num; i++) {
+ d = tty_register_device(driver, i, NULL);
+ if (IS_ERR(d)) {
+ error = PTR_ERR(d);
+ goto err;
+ }
+ }
+ }
+ proc_tty_register_driver(driver);
+ driver->flags |= TTY_DRIVER_INSTALLED;
+ return 0;
+
+err:
+ for (i--; i >= 0; i--)
+ tty_unregister_device(driver, i);
+
+ mutex_lock(&tty_mutex);
+ list_del(&driver->tty_drivers);
+ mutex_unlock(&tty_mutex);
+
+ unregister_chrdev_region(dev, driver->num);
+ driver->ttys = NULL;
+ driver->termios = NULL;
+ kfree(p);
+ return error;
+}
+
+EXPORT_SYMBOL(tty_register_driver);
+
+/*
+ * Called by a tty driver to unregister itself.
+ */
+int tty_unregister_driver(struct tty_driver *driver)
+{
+#if 0
+ /* FIXME */
+ if (driver->refcount)
+ return -EBUSY;
+#endif
+ unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
+ driver->num);
+ mutex_lock(&tty_mutex);
+ list_del(&driver->tty_drivers);
+ mutex_unlock(&tty_mutex);
+ return 0;
+}
+
+EXPORT_SYMBOL(tty_unregister_driver);
+
+dev_t tty_devnum(struct tty_struct *tty)
+{
+ return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
+}
+EXPORT_SYMBOL(tty_devnum);
+
+void proc_clear_tty(struct task_struct *p)
+{
+ unsigned long flags;
+ struct tty_struct *tty;
+ spin_lock_irqsave(&p->sighand->siglock, flags);
+ tty = p->signal->tty;
+ p->signal->tty = NULL;
+ spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ tty_kref_put(tty);
+}
+
+/* Called under the sighand lock */
+
+static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+{
+ if (tty) {
+ unsigned long flags;
+ /* We should not have a session or pgrp to put here but.... */
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ put_pid(tty->session);
+ put_pid(tty->pgrp);
+ tty->pgrp = get_pid(task_pgrp(tsk));
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ tty->session = get_pid(task_session(tsk));
+ if (tsk->signal->tty) {
+ printk(KERN_DEBUG "tty not NULL!!\n");
+ tty_kref_put(tsk->signal->tty);
+ }
+ }
+ put_pid(tsk->signal->tty_old_pgrp);
+ tsk->signal->tty = tty_kref_get(tty);
+ tsk->signal->tty_old_pgrp = NULL;
+}
+
+static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
+{
+ spin_lock_irq(&tsk->sighand->siglock);
+ __proc_set_tty(tsk, tty);
+ spin_unlock_irq(&tsk->sighand->siglock);
+}
+
+struct tty_struct *get_current_tty(void)
+{
+ struct tty_struct *tty;
+ unsigned long flags;
+
+ spin_lock_irqsave(¤t->sighand->siglock, flags);
+ tty = tty_kref_get(current->signal->tty);
+ spin_unlock_irqrestore(¤t->sighand->siglock, flags);
+ return tty;
+}
+EXPORT_SYMBOL_GPL(get_current_tty);
+
+void tty_default_fops(struct file_operations *fops)
+{
+ *fops = tty_fops;
+}
+
+/*
+ * Initialize the console device. This is called *early*, so
+ * we can't necessarily depend on lots of kernel help here.
+ * Just do some early initializations, and do the complex setup
+ * later.
+ */
+void __init console_init(void)
+{
+ initcall_t *call;
+
+ /* Setup the default TTY line discipline. */
+ tty_ldisc_begin();
+
+ /*
+ * set up the console device so that later boot sequences can
+ * inform about problems etc..
+ */
+ call = __con_initcall_start;
+ while (call < __con_initcall_end) {
+ (*call)();
+ call++;
+ }
+}
+
+static char *tty_devnode(struct device *dev, mode_t *mode)
+{
+ if (!mode)
+ return NULL;
+ if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) ||
+ dev->devt == MKDEV(TTYAUX_MAJOR, 2))
+ *mode = 0666;
+ return NULL;
+}
+
+static int __init tty_class_init(void)
+{
+ tty_class = class_create(THIS_MODULE, "tty");
+ if (IS_ERR(tty_class))
+ return PTR_ERR(tty_class);
+ tty_class->devnode = tty_devnode;
+ return 0;
+}
+
+postcore_initcall(tty_class_init);
+
+/* 3/2004 jmc: why do these devices exist? */
+
+static struct cdev tty_cdev, console_cdev;
+
+/*
+ * Ok, now we can initialize the rest of the tty devices and can count
+ * on memory allocations, interrupts etc..
+ */
+int __init tty_init(void)
+{
+ cdev_init(&tty_cdev, &tty_fops);
+ if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
+ register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
+ panic("Couldn't register /dev/tty driver\n");
+ device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL,
+ "tty");
+
+ cdev_init(&console_cdev, &console_fops);
+ if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
+ register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
+ panic("Couldn't register /dev/console driver\n");
+ device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
+ "console");
+
+#ifdef CONFIG_VT
+ vty_init(&console_fops);
+#endif
+ return 0;
+}
+
--- /dev/null
+/*
+ * linux/drivers/char/tty_ioctl.c
+ *
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
+ * which can be dynamically activated and de-activated by the line
+ * discipline handling modules (like SLIP).
+ */
+
+#include <linux/types.h>
+#include <linux/termios.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/tty.h>
+#include <linux/fcntl.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/mutex.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#undef TTY_DEBUG_WAIT_UNTIL_SENT
+
+#undef DEBUG
+
+/*
+ * Internal flag options for termios setting behavior
+ */
+#define TERMIOS_FLUSH 1
+#define TERMIOS_WAIT 2
+#define TERMIOS_TERMIO 4
+#define TERMIOS_OLD 8
+
+
+/**
+ * tty_chars_in_buffer - characters pending
+ * @tty: terminal
+ *
+ * Return the number of bytes of data in the device private
+ * output queue. If no private method is supplied there is assumed
+ * to be no queue on the device.
+ */
+
+int tty_chars_in_buffer(struct tty_struct *tty)
+{
+ if (tty->ops->chars_in_buffer)
+ return tty->ops->chars_in_buffer(tty);
+ else
+ return 0;
+}
+EXPORT_SYMBOL(tty_chars_in_buffer);
+
+/**
+ * tty_write_room - write queue space
+ * @tty: terminal
+ *
+ * Return the number of bytes that can be queued to this device
+ * at the present time. The result should be treated as a guarantee
+ * and the driver cannot offer a value it later shrinks by more than
+ * the number of bytes written. If no method is provided 2K is always
+ * returned and data may be lost as there will be no flow control.
+ */
+
+int tty_write_room(struct tty_struct *tty)
+{
+ if (tty->ops->write_room)
+ return tty->ops->write_room(tty);
+ return 2048;
+}
+EXPORT_SYMBOL(tty_write_room);
+
+/**
+ * tty_driver_flush_buffer - discard internal buffer
+ * @tty: terminal
+ *
+ * Discard the internal output buffer for this device. If no method
+ * is provided then either the buffer cannot be hardware flushed or
+ * there is no buffer driver side.
+ */
+void tty_driver_flush_buffer(struct tty_struct *tty)
+{
+ if (tty->ops->flush_buffer)
+ tty->ops->flush_buffer(tty);
+}
+EXPORT_SYMBOL(tty_driver_flush_buffer);
+
+/**
+ * tty_throttle - flow control
+ * @tty: terminal
+ *
+ * Indicate that a tty should stop transmitting data down the stack.
+ * Takes the termios mutex to protect against parallel throttle/unthrottle
+ * and also to ensure the driver can consistently reference its own
+ * termios data at this point when implementing software flow control.
+ */
+
+void tty_throttle(struct tty_struct *tty)
+{
+ mutex_lock(&tty->termios_mutex);
+ /* check TTY_THROTTLED first so it indicates our state */
+ if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
+ tty->ops->throttle)
+ tty->ops->throttle(tty);
+ mutex_unlock(&tty->termios_mutex);
+}
+EXPORT_SYMBOL(tty_throttle);
+
+/**
+ * tty_unthrottle - flow control
+ * @tty: terminal
+ *
+ * Indicate that a tty may continue transmitting data down the stack.
+ * Takes the termios mutex to protect against parallel throttle/unthrottle
+ * and also to ensure the driver can consistently reference its own
+ * termios data at this point when implementing software flow control.
+ *
+ * Drivers should however remember that the stack can issue a throttle,
+ * then change flow control method, then unthrottle.
+ */
+
+void tty_unthrottle(struct tty_struct *tty)
+{
+ mutex_lock(&tty->termios_mutex);
+ if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
+ tty->ops->unthrottle)
+ tty->ops->unthrottle(tty);
+ mutex_unlock(&tty->termios_mutex);
+}
+EXPORT_SYMBOL(tty_unthrottle);
+
+/**
+ * tty_wait_until_sent - wait for I/O to finish
+ * @tty: tty we are waiting for
+ * @timeout: how long we will wait
+ *
+ * Wait for characters pending in a tty driver to hit the wire, or
+ * for a timeout to occur (eg due to flow control)
+ *
+ * Locking: none
+ */
+
+void tty_wait_until_sent(struct tty_struct *tty, long timeout)
+{
+#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
+ char buf[64];
+
+ printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
+#endif
+ if (!timeout)
+ timeout = MAX_SCHEDULE_TIMEOUT;
+ if (wait_event_interruptible_timeout(tty->write_wait,
+ !tty_chars_in_buffer(tty), timeout) >= 0) {
+ if (tty->ops->wait_until_sent)
+ tty->ops->wait_until_sent(tty, timeout);
+ }
+}
+EXPORT_SYMBOL(tty_wait_until_sent);
+
+
+/*
+ * Termios Helper Methods
+ */
+
+static void unset_locked_termios(struct ktermios *termios,
+ struct ktermios *old,
+ struct ktermios *locked)
+{
+ int i;
+
+#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
+
+ if (!locked) {
+ printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
+ return;
+ }
+
+ NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
+ NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
+ NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
+ NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
+ termios->c_line = locked->c_line ? old->c_line : termios->c_line;
+ for (i = 0; i < NCCS; i++)
+ termios->c_cc[i] = locked->c_cc[i] ?
+ old->c_cc[i] : termios->c_cc[i];
+ /* FIXME: What should we do for i/ospeed */
+}
+
+/*
+ * Routine which returns the baud rate of the tty
+ *
+ * Note that the baud_table needs to be kept in sync with the
+ * include/asm/termbits.h file.
+ */
+static const speed_t baud_table[] = {
+ 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
+ 9600, 19200, 38400, 57600, 115200, 230400, 460800,
+#ifdef __sparc__
+ 76800, 153600, 307200, 614400, 921600
+#else
+ 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
+ 2500000, 3000000, 3500000, 4000000
+#endif
+};
+
+#ifndef __sparc__
+static const tcflag_t baud_bits[] = {
+ B0, B50, B75, B110, B134, B150, B200, B300, B600,
+ B1200, B1800, B2400, B4800, B9600, B19200, B38400,
+ B57600, B115200, B230400, B460800, B500000, B576000,
+ B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
+ B3000000, B3500000, B4000000
+};
+#else
+static const tcflag_t baud_bits[] = {
+ B0, B50, B75, B110, B134, B150, B200, B300, B600,
+ B1200, B1800, B2400, B4800, B9600, B19200, B38400,
+ B57600, B115200, B230400, B460800, B76800, B153600,
+ B307200, B614400, B921600
+};
+#endif
+
+static int n_baud_table = ARRAY_SIZE(baud_table);
+
+/**
+ * tty_termios_baud_rate
+ * @termios: termios structure
+ *
+ * Convert termios baud rate data into a speed. This should be called
+ * with the termios lock held if this termios is a terminal termios
+ * structure. May change the termios data. Device drivers can call this
+ * function but should use ->c_[io]speed directly as they are updated.
+ *
+ * Locking: none
+ */
+
+speed_t tty_termios_baud_rate(struct ktermios *termios)
+{
+ unsigned int cbaud;
+
+ cbaud = termios->c_cflag & CBAUD;
+
+#ifdef BOTHER
+ /* Magic token for arbitary speed via c_ispeed/c_ospeed */
+ if (cbaud == BOTHER)
+ return termios->c_ospeed;
+#endif
+ if (cbaud & CBAUDEX) {
+ cbaud &= ~CBAUDEX;
+
+ if (cbaud < 1 || cbaud + 15 > n_baud_table)
+ termios->c_cflag &= ~CBAUDEX;
+ else
+ cbaud += 15;
+ }
+ return baud_table[cbaud];
+}
+EXPORT_SYMBOL(tty_termios_baud_rate);
+
+/**
+ * tty_termios_input_baud_rate
+ * @termios: termios structure
+ *
+ * Convert termios baud rate data into a speed. This should be called
+ * with the termios lock held if this termios is a terminal termios
+ * structure. May change the termios data. Device drivers can call this
+ * function but should use ->c_[io]speed directly as they are updated.
+ *
+ * Locking: none
+ */
+
+speed_t tty_termios_input_baud_rate(struct ktermios *termios)
+{
+#ifdef IBSHIFT
+ unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
+
+ if (cbaud == B0)
+ return tty_termios_baud_rate(termios);
+
+ /* Magic token for arbitary speed via c_ispeed*/
+ if (cbaud == BOTHER)
+ return termios->c_ispeed;
+
+ if (cbaud & CBAUDEX) {
+ cbaud &= ~CBAUDEX;
+
+ if (cbaud < 1 || cbaud + 15 > n_baud_table)
+ termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
+ else
+ cbaud += 15;
+ }
+ return baud_table[cbaud];
+#else
+ return tty_termios_baud_rate(termios);
+#endif
+}
+EXPORT_SYMBOL(tty_termios_input_baud_rate);
+
+/**
+ * tty_termios_encode_baud_rate
+ * @termios: ktermios structure holding user requested state
+ * @ispeed: input speed
+ * @ospeed: output speed
+ *
+ * Encode the speeds set into the passed termios structure. This is
+ * used as a library helper for drivers os that they can report back
+ * the actual speed selected when it differs from the speed requested
+ *
+ * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
+ * we need to carefully set the bits when the user does not get the
+ * desired speed. We allow small margins and preserve as much of possible
+ * of the input intent to keep compatibility.
+ *
+ * Locking: Caller should hold termios lock. This is already held
+ * when calling this function from the driver termios handler.
+ *
+ * The ifdefs deal with platforms whose owners have yet to update them
+ * and will all go away once this is done.
+ */
+
+void tty_termios_encode_baud_rate(struct ktermios *termios,
+ speed_t ibaud, speed_t obaud)
+{
+ int i = 0;
+ int ifound = -1, ofound = -1;
+ int iclose = ibaud/50, oclose = obaud/50;
+ int ibinput = 0;
+
+ if (obaud == 0) /* CD dropped */
+ ibaud = 0; /* Clear ibaud to be sure */
+
+ termios->c_ispeed = ibaud;
+ termios->c_ospeed = obaud;
+
+#ifdef BOTHER
+ /* If the user asked for a precise weird speed give a precise weird
+ answer. If they asked for a Bfoo speed they many have problems
+ digesting non-exact replies so fuzz a bit */
+
+ if ((termios->c_cflag & CBAUD) == BOTHER)
+ oclose = 0;
+ if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
+ iclose = 0;
+ if ((termios->c_cflag >> IBSHIFT) & CBAUD)
+ ibinput = 1; /* An input speed was specified */
+#endif
+ termios->c_cflag &= ~CBAUD;
+
+ /*
+ * Our goal is to find a close match to the standard baud rate
+ * returned. Walk the baud rate table and if we get a very close
+ * match then report back the speed as a POSIX Bxxxx value by
+ * preference
+ */
+
+ do {
+ if (obaud - oclose <= baud_table[i] &&
+ obaud + oclose >= baud_table[i]) {
+ termios->c_cflag |= baud_bits[i];
+ ofound = i;
+ }
+ if (ibaud - iclose <= baud_table[i] &&
+ ibaud + iclose >= baud_table[i]) {
+ /* For the case input == output don't set IBAUD bits
+ if the user didn't do so */
+ if (ofound == i && !ibinput)
+ ifound = i;
+#ifdef IBSHIFT
+ else {
+ ifound = i;
+ termios->c_cflag |= (baud_bits[i] << IBSHIFT);
+ }
+#endif
+ }
+ } while (++i < n_baud_table);
+
+ /*
+ * If we found no match then use BOTHER if provided or warn
+ * the user their platform maintainer needs to wake up if not.
+ */
+#ifdef BOTHER
+ if (ofound == -1)
+ termios->c_cflag |= BOTHER;
+ /* Set exact input bits only if the input and output differ or the
+ user already did */
+ if (ifound == -1 && (ibaud != obaud || ibinput))
+ termios->c_cflag |= (BOTHER << IBSHIFT);
+#else
+ if (ifound == -1 || ofound == -1) {
+ printk_once(KERN_WARNING "tty: Unable to return correct "
+ "speed data as your architecture needs updating.\n");
+ }
+#endif
+}
+EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
+
+/**
+ * tty_encode_baud_rate - set baud rate of the tty
+ * @ibaud: input baud rate
+ * @obad: output baud rate
+ *
+ * Update the current termios data for the tty with the new speed
+ * settings. The caller must hold the termios_mutex for the tty in
+ * question.
+ */
+
+void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
+{
+ tty_termios_encode_baud_rate(tty->termios, ibaud, obaud);
+}
+EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
+
+/**
+ * tty_get_baud_rate - get tty bit rates
+ * @tty: tty to query
+ *
+ * Returns the baud rate as an integer for this terminal. The
+ * termios lock must be held by the caller and the terminal bit
+ * flags may be updated.
+ *
+ * Locking: none
+ */
+
+speed_t tty_get_baud_rate(struct tty_struct *tty)
+{
+ speed_t baud = tty_termios_baud_rate(tty->termios);
+
+ if (baud == 38400 && tty->alt_speed) {
+ if (!tty->warned) {
+ printk(KERN_WARNING "Use of setserial/setrocket to "
+ "set SPD_* flags is deprecated\n");
+ tty->warned = 1;
+ }
+ baud = tty->alt_speed;
+ }
+
+ return baud;
+}
+EXPORT_SYMBOL(tty_get_baud_rate);
+
+/**
+ * tty_termios_copy_hw - copy hardware settings
+ * @new: New termios
+ * @old: Old termios
+ *
+ * Propogate the hardware specific terminal setting bits from
+ * the old termios structure to the new one. This is used in cases
+ * where the hardware does not support reconfiguration or as a helper
+ * in some cases where only minimal reconfiguration is supported
+ */
+
+void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
+{
+ /* The bits a dumb device handles in software. Smart devices need
+ to always provide a set_termios method */
+ new->c_cflag &= HUPCL | CREAD | CLOCAL;
+ new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
+ new->c_ispeed = old->c_ispeed;
+ new->c_ospeed = old->c_ospeed;
+}
+EXPORT_SYMBOL(tty_termios_copy_hw);
+
+/**
+ * tty_termios_hw_change - check for setting change
+ * @a: termios
+ * @b: termios to compare
+ *
+ * Check if any of the bits that affect a dumb device have changed
+ * between the two termios structures, or a speed change is needed.
+ */
+
+int tty_termios_hw_change(struct ktermios *a, struct ktermios *b)
+{
+ if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
+ return 1;
+ if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
+ return 1;
+ return 0;
+}
+EXPORT_SYMBOL(tty_termios_hw_change);
+
+/**
+ * change_termios - update termios values
+ * @tty: tty to update
+ * @new_termios: desired new value
+ *
+ * Perform updates to the termios values set on this terminal. There
+ * is a bit of layering violation here with n_tty in terms of the
+ * internal knowledge of this function.
+ *
+ * Locking: termios_mutex
+ */
+
+static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
+{
+ struct ktermios old_termios;
+ struct tty_ldisc *ld;
+ unsigned long flags;
+
+ /*
+ * Perform the actual termios internal changes under lock.
+ */
+
+
+ /* FIXME: we need to decide on some locking/ordering semantics
+ for the set_termios notification eventually */
+ mutex_lock(&tty->termios_mutex);
+ old_termios = *tty->termios;
+ *tty->termios = *new_termios;
+ unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
+
+ /* See if packet mode change of state. */
+ if (tty->link && tty->link->packet) {
+ int extproc = (old_termios.c_lflag & EXTPROC) |
+ (tty->termios->c_lflag & EXTPROC);
+ int old_flow = ((old_termios.c_iflag & IXON) &&
+ (old_termios.c_cc[VSTOP] == '\023') &&
+ (old_termios.c_cc[VSTART] == '\021'));
+ int new_flow = (I_IXON(tty) &&
+ STOP_CHAR(tty) == '\023' &&
+ START_CHAR(tty) == '\021');
+ if ((old_flow != new_flow) || extproc) {
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ if (old_flow != new_flow) {
+ tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
+ if (new_flow)
+ tty->ctrl_status |= TIOCPKT_DOSTOP;
+ else
+ tty->ctrl_status |= TIOCPKT_NOSTOP;
+ }
+ if (extproc)
+ tty->ctrl_status |= TIOCPKT_IOCTL;
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ wake_up_interruptible(&tty->link->read_wait);
+ }
+ }
+
+ if (tty->ops->set_termios)
+ (*tty->ops->set_termios)(tty, &old_termios);
+ else
+ tty_termios_copy_hw(tty->termios, &old_termios);
+
+ ld = tty_ldisc_ref(tty);
+ if (ld != NULL) {
+ if (ld->ops->set_termios)
+ (ld->ops->set_termios)(tty, &old_termios);
+ tty_ldisc_deref(ld);
+ }
+ mutex_unlock(&tty->termios_mutex);
+}
+
+/**
+ * set_termios - set termios values for a tty
+ * @tty: terminal device
+ * @arg: user data
+ * @opt: option information
+ *
+ * Helper function to prepare termios data and run necessary other
+ * functions before using change_termios to do the actual changes.
+ *
+ * Locking:
+ * Called functions take ldisc and termios_mutex locks
+ */
+
+static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
+{
+ struct ktermios tmp_termios;
+ struct tty_ldisc *ld;
+ int retval = tty_check_change(tty);
+
+ if (retval)
+ return retval;
+
+ mutex_lock(&tty->termios_mutex);
+ memcpy(&tmp_termios, tty->termios, sizeof(struct ktermios));
+ mutex_unlock(&tty->termios_mutex);
+
+ if (opt & TERMIOS_TERMIO) {
+ if (user_termio_to_kernel_termios(&tmp_termios,
+ (struct termio __user *)arg))
+ return -EFAULT;
+#ifdef TCGETS2
+ } else if (opt & TERMIOS_OLD) {
+ if (user_termios_to_kernel_termios_1(&tmp_termios,
+ (struct termios __user *)arg))
+ return -EFAULT;
+ } else {
+ if (user_termios_to_kernel_termios(&tmp_termios,
+ (struct termios2 __user *)arg))
+ return -EFAULT;
+ }
+#else
+ } else if (user_termios_to_kernel_termios(&tmp_termios,
+ (struct termios __user *)arg))
+ return -EFAULT;
+#endif
+
+ /* If old style Bfoo values are used then load c_ispeed/c_ospeed
+ * with the real speed so its unconditionally usable */
+ tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
+ tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
+
+ ld = tty_ldisc_ref(tty);
+
+ if (ld != NULL) {
+ if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+ ld->ops->flush_buffer(tty);
+ tty_ldisc_deref(ld);
+ }
+
+ if (opt & TERMIOS_WAIT) {
+ tty_wait_until_sent(tty, 0);
+ if (signal_pending(current))
+ return -EINTR;
+ }
+
+ change_termios(tty, &tmp_termios);
+
+ /* FIXME: Arguably if tmp_termios == tty->termios AND the
+ actual requested termios was not tmp_termios then we may
+ want to return an error as no user requested change has
+ succeeded */
+ return 0;
+}
+
+static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
+{
+ mutex_lock(&tty->termios_mutex);
+ memcpy(kterm, tty->termios, sizeof(struct ktermios));
+ mutex_unlock(&tty->termios_mutex);
+}
+
+static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
+{
+ mutex_lock(&tty->termios_mutex);
+ memcpy(kterm, tty->termios_locked, sizeof(struct ktermios));
+ mutex_unlock(&tty->termios_mutex);
+}
+
+static int get_termio(struct tty_struct *tty, struct termio __user *termio)
+{
+ struct ktermios kterm;
+ copy_termios(tty, &kterm);
+ if (kernel_termios_to_user_termio(termio, &kterm))
+ return -EFAULT;
+ return 0;
+}
+
+
+#ifdef TCGETX
+
+/**
+ * set_termiox - set termiox fields if possible
+ * @tty: terminal
+ * @arg: termiox structure from user
+ * @opt: option flags for ioctl type
+ *
+ * Implement the device calling points for the SYS5 termiox ioctl
+ * interface in Linux
+ */
+
+static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
+{
+ struct termiox tnew;
+ struct tty_ldisc *ld;
+
+ if (tty->termiox == NULL)
+ return -EINVAL;
+ if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
+ return -EFAULT;
+
+ ld = tty_ldisc_ref(tty);
+ if (ld != NULL) {
+ if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+ ld->ops->flush_buffer(tty);
+ tty_ldisc_deref(ld);
+ }
+ if (opt & TERMIOS_WAIT) {
+ tty_wait_until_sent(tty, 0);
+ if (signal_pending(current))
+ return -EINTR;
+ }
+
+ mutex_lock(&tty->termios_mutex);
+ if (tty->ops->set_termiox)
+ tty->ops->set_termiox(tty, &tnew);
+ mutex_unlock(&tty->termios_mutex);
+ return 0;
+}
+
+#endif
+
+
+#ifdef TIOCGETP
+/*
+ * These are deprecated, but there is limited support..
+ *
+ * The "sg_flags" translation is a joke..
+ */
+static int get_sgflags(struct tty_struct *tty)
+{
+ int flags = 0;
+
+ if (!(tty->termios->c_lflag & ICANON)) {
+ if (tty->termios->c_lflag & ISIG)
+ flags |= 0x02; /* cbreak */
+ else
+ flags |= 0x20; /* raw */
+ }
+ if (tty->termios->c_lflag & ECHO)
+ flags |= 0x08; /* echo */
+ if (tty->termios->c_oflag & OPOST)
+ if (tty->termios->c_oflag & ONLCR)
+ flags |= 0x10; /* crmod */
+ return flags;
+}
+
+static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
+{
+ struct sgttyb tmp;
+
+ mutex_lock(&tty->termios_mutex);
+ tmp.sg_ispeed = tty->termios->c_ispeed;
+ tmp.sg_ospeed = tty->termios->c_ospeed;
+ tmp.sg_erase = tty->termios->c_cc[VERASE];
+ tmp.sg_kill = tty->termios->c_cc[VKILL];
+ tmp.sg_flags = get_sgflags(tty);
+ mutex_unlock(&tty->termios_mutex);
+
+ return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+static void set_sgflags(struct ktermios *termios, int flags)
+{
+ termios->c_iflag = ICRNL | IXON;
+ termios->c_oflag = 0;
+ termios->c_lflag = ISIG | ICANON;
+ if (flags & 0x02) { /* cbreak */
+ termios->c_iflag = 0;
+ termios->c_lflag &= ~ICANON;
+ }
+ if (flags & 0x08) { /* echo */
+ termios->c_lflag |= ECHO | ECHOE | ECHOK |
+ ECHOCTL | ECHOKE | IEXTEN;
+ }
+ if (flags & 0x10) { /* crmod */
+ termios->c_oflag |= OPOST | ONLCR;
+ }
+ if (flags & 0x20) { /* raw */
+ termios->c_iflag = 0;
+ termios->c_lflag &= ~(ISIG | ICANON);
+ }
+ if (!(termios->c_lflag & ICANON)) {
+ termios->c_cc[VMIN] = 1;
+ termios->c_cc[VTIME] = 0;
+ }
+}
+
+/**
+ * set_sgttyb - set legacy terminal values
+ * @tty: tty structure
+ * @sgttyb: pointer to old style terminal structure
+ *
+ * Updates a terminal from the legacy BSD style terminal information
+ * structure.
+ *
+ * Locking: termios_mutex
+ */
+
+static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
+{
+ int retval;
+ struct sgttyb tmp;
+ struct ktermios termios;
+
+ retval = tty_check_change(tty);
+ if (retval)
+ return retval;
+
+ if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
+ return -EFAULT;
+
+ mutex_lock(&tty->termios_mutex);
+ termios = *tty->termios;
+ termios.c_cc[VERASE] = tmp.sg_erase;
+ termios.c_cc[VKILL] = tmp.sg_kill;
+ set_sgflags(&termios, tmp.sg_flags);
+ /* Try and encode into Bfoo format */
+#ifdef BOTHER
+ tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
+ termios.c_ospeed);
+#endif
+ mutex_unlock(&tty->termios_mutex);
+ change_termios(tty, &termios);
+ return 0;
+}
+#endif
+
+#ifdef TIOCGETC
+static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
+{
+ struct tchars tmp;
+
+ mutex_lock(&tty->termios_mutex);
+ tmp.t_intrc = tty->termios->c_cc[VINTR];
+ tmp.t_quitc = tty->termios->c_cc[VQUIT];
+ tmp.t_startc = tty->termios->c_cc[VSTART];
+ tmp.t_stopc = tty->termios->c_cc[VSTOP];
+ tmp.t_eofc = tty->termios->c_cc[VEOF];
+ tmp.t_brkc = tty->termios->c_cc[VEOL2]; /* what is brkc anyway? */
+ mutex_unlock(&tty->termios_mutex);
+ return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
+{
+ struct tchars tmp;
+
+ if (copy_from_user(&tmp, tchars, sizeof(tmp)))
+ return -EFAULT;
+ mutex_lock(&tty->termios_mutex);
+ tty->termios->c_cc[VINTR] = tmp.t_intrc;
+ tty->termios->c_cc[VQUIT] = tmp.t_quitc;
+ tty->termios->c_cc[VSTART] = tmp.t_startc;
+ tty->termios->c_cc[VSTOP] = tmp.t_stopc;
+ tty->termios->c_cc[VEOF] = tmp.t_eofc;
+ tty->termios->c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
+ mutex_unlock(&tty->termios_mutex);
+ return 0;
+}
+#endif
+
+#ifdef TIOCGLTC
+static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
+{
+ struct ltchars tmp;
+
+ mutex_lock(&tty->termios_mutex);
+ tmp.t_suspc = tty->termios->c_cc[VSUSP];
+ /* what is dsuspc anyway? */
+ tmp.t_dsuspc = tty->termios->c_cc[VSUSP];
+ tmp.t_rprntc = tty->termios->c_cc[VREPRINT];
+ /* what is flushc anyway? */
+ tmp.t_flushc = tty->termios->c_cc[VEOL2];
+ tmp.t_werasc = tty->termios->c_cc[VWERASE];
+ tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
+ mutex_unlock(&tty->termios_mutex);
+ return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
+}
+
+static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
+{
+ struct ltchars tmp;
+
+ if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
+ return -EFAULT;
+
+ mutex_lock(&tty->termios_mutex);
+ tty->termios->c_cc[VSUSP] = tmp.t_suspc;
+ /* what is dsuspc anyway? */
+ tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;
+ tty->termios->c_cc[VREPRINT] = tmp.t_rprntc;
+ /* what is flushc anyway? */
+ tty->termios->c_cc[VEOL2] = tmp.t_flushc;
+ tty->termios->c_cc[VWERASE] = tmp.t_werasc;
+ tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
+ mutex_unlock(&tty->termios_mutex);
+ return 0;
+}
+#endif
+
+/**
+ * send_prio_char - send priority character
+ *
+ * Send a high priority character to the tty even if stopped
+ *
+ * Locking: none for xchar method, write ordering for write method.
+ */
+
+static int send_prio_char(struct tty_struct *tty, char ch)
+{
+ int was_stopped = tty->stopped;
+
+ if (tty->ops->send_xchar) {
+ tty->ops->send_xchar(tty, ch);
+ return 0;
+ }
+
+ if (tty_write_lock(tty, 0) < 0)
+ return -ERESTARTSYS;
+
+ if (was_stopped)
+ start_tty(tty);
+ tty->ops->write(tty, &ch, 1);
+ if (was_stopped)
+ stop_tty(tty);
+ tty_write_unlock(tty);
+ return 0;
+}
+
+/**
+ * tty_change_softcar - carrier change ioctl helper
+ * @tty: tty to update
+ * @arg: enable/disable CLOCAL
+ *
+ * Perform a change to the CLOCAL state and call into the driver
+ * layer to make it visible. All done with the termios mutex
+ */
+
+static int tty_change_softcar(struct tty_struct *tty, int arg)
+{
+ int ret = 0;
+ int bit = arg ? CLOCAL : 0;
+ struct ktermios old;
+
+ mutex_lock(&tty->termios_mutex);
+ old = *tty->termios;
+ tty->termios->c_cflag &= ~CLOCAL;
+ tty->termios->c_cflag |= bit;
+ if (tty->ops->set_termios)
+ tty->ops->set_termios(tty, &old);
+ if ((tty->termios->c_cflag & CLOCAL) != bit)
+ ret = -EINVAL;
+ mutex_unlock(&tty->termios_mutex);
+ return ret;
+}
+
+/**
+ * tty_mode_ioctl - mode related ioctls
+ * @tty: tty for the ioctl
+ * @file: file pointer for the tty
+ * @cmd: command
+ * @arg: ioctl argument
+ *
+ * Perform non line discipline specific mode control ioctls. This
+ * is designed to be called by line disciplines to ensure they provide
+ * consistent mode setting.
+ */
+
+int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct tty_struct *real_tty;
+ void __user *p = (void __user *)arg;
+ int ret = 0;
+ struct ktermios kterm;
+
+ if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+ tty->driver->subtype == PTY_TYPE_MASTER)
+ real_tty = tty->link;
+ else
+ real_tty = tty;
+
+ switch (cmd) {
+#ifdef TIOCGETP
+ case TIOCGETP:
+ return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
+ case TIOCSETP:
+ case TIOCSETN:
+ return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
+#endif
+#ifdef TIOCGETC
+ case TIOCGETC:
+ return get_tchars(real_tty, p);
+ case TIOCSETC:
+ return set_tchars(real_tty, p);
+#endif
+#ifdef TIOCGLTC
+ case TIOCGLTC:
+ return get_ltchars(real_tty, p);
+ case TIOCSLTC:
+ return set_ltchars(real_tty, p);
+#endif
+ case TCSETSF:
+ return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
+ case TCSETSW:
+ return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
+ case TCSETS:
+ return set_termios(real_tty, p, TERMIOS_OLD);
+#ifndef TCGETS2
+ case TCGETS:
+ copy_termios(real_tty, &kterm);
+ if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
+ ret = -EFAULT;
+ return ret;
+#else
+ case TCGETS:
+ copy_termios(real_tty, &kterm);
+ if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
+ ret = -EFAULT;
+ return ret;
+ case TCGETS2:
+ copy_termios(real_tty, &kterm);
+ if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
+ ret = -EFAULT;
+ return ret;
+ case TCSETSF2:
+ return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
+ case TCSETSW2:
+ return set_termios(real_tty, p, TERMIOS_WAIT);
+ case TCSETS2:
+ return set_termios(real_tty, p, 0);
+#endif
+ case TCGETA:
+ return get_termio(real_tty, p);
+ case TCSETAF:
+ return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
+ case TCSETAW:
+ return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
+ case TCSETA:
+ return set_termios(real_tty, p, TERMIOS_TERMIO);
+#ifndef TCGETS2
+ case TIOCGLCKTRMIOS:
+ copy_termios_locked(real_tty, &kterm);
+ if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
+ ret = -EFAULT;
+ return ret;
+ case TIOCSLCKTRMIOS:
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ copy_termios_locked(real_tty, &kterm);
+ if (user_termios_to_kernel_termios(&kterm,
+ (struct termios __user *) arg))
+ return -EFAULT;
+ mutex_lock(&real_tty->termios_mutex);
+ memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
+ mutex_unlock(&real_tty->termios_mutex);
+ return 0;
+#else
+ case TIOCGLCKTRMIOS:
+ copy_termios_locked(real_tty, &kterm);
+ if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
+ ret = -EFAULT;
+ return ret;
+ case TIOCSLCKTRMIOS:
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ copy_termios_locked(real_tty, &kterm);
+ if (user_termios_to_kernel_termios_1(&kterm,
+ (struct termios __user *) arg))
+ return -EFAULT;
+ mutex_lock(&real_tty->termios_mutex);
+ memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
+#endif
+#ifdef TCGETX
+ case TCGETX: {
+ struct termiox ktermx;
+ if (real_tty->termiox == NULL)
+ return -EINVAL;
+ mutex_lock(&real_tty->termios_mutex);
+ memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
+ mutex_unlock(&real_tty->termios_mutex);
+ if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
+ ret = -EFAULT;
+ return ret;
+ }
+ case TCSETX:
+ return set_termiox(real_tty, p, 0);
+ case TCSETXW:
+ return set_termiox(real_tty, p, TERMIOS_WAIT);
+ case TCSETXF:
+ return set_termiox(real_tty, p, TERMIOS_FLUSH);
+#endif
+ case TIOCGSOFTCAR:
+ copy_termios(real_tty, &kterm);
+ ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
+ (int __user *)arg);
+ return ret;
+ case TIOCSSOFTCAR:
+ if (get_user(arg, (unsigned int __user *) arg))
+ return -EFAULT;
+ return tty_change_softcar(real_tty, arg);
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+EXPORT_SYMBOL_GPL(tty_mode_ioctl);
+
+int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
+{
+ struct tty_ldisc *ld;
+ int retval = tty_check_change(tty);
+ if (retval)
+ return retval;
+
+ ld = tty_ldisc_ref_wait(tty);
+ switch (arg) {
+ case TCIFLUSH:
+ if (ld && ld->ops->flush_buffer)
+ ld->ops->flush_buffer(tty);
+ break;
+ case TCIOFLUSH:
+ if (ld && ld->ops->flush_buffer)
+ ld->ops->flush_buffer(tty);
+ /* fall through */
+ case TCOFLUSH:
+ tty_driver_flush_buffer(tty);
+ break;
+ default:
+ tty_ldisc_deref(ld);
+ return -EINVAL;
+ }
+ tty_ldisc_deref(ld);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tty_perform_flush);
+
+int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ unsigned long flags;
+ int retval;
+
+ switch (cmd) {
+ case TCXONC:
+ retval = tty_check_change(tty);
+ if (retval)
+ return retval;
+ switch (arg) {
+ case TCOOFF:
+ if (!tty->flow_stopped) {
+ tty->flow_stopped = 1;
+ stop_tty(tty);
+ }
+ break;
+ case TCOON:
+ if (tty->flow_stopped) {
+ tty->flow_stopped = 0;
+ start_tty(tty);
+ }
+ break;
+ case TCIOFF:
+ if (STOP_CHAR(tty) != __DISABLED_CHAR)
+ return send_prio_char(tty, STOP_CHAR(tty));
+ break;
+ case TCION:
+ if (START_CHAR(tty) != __DISABLED_CHAR)
+ return send_prio_char(tty, START_CHAR(tty));
+ break;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+ case TCFLSH:
+ return tty_perform_flush(tty, arg);
+ case TIOCPKT:
+ {
+ int pktmode;
+
+ if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
+ tty->driver->subtype != PTY_TYPE_MASTER)
+ return -ENOTTY;
+ if (get_user(pktmode, (int __user *) arg))
+ return -EFAULT;
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ if (pktmode) {
+ if (!tty->packet) {
+ tty->packet = 1;
+ tty->link->ctrl_status = 0;
+ }
+ } else
+ tty->packet = 0;
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ return 0;
+ }
+ default:
+ /* Try the mode commands */
+ return tty_mode_ioctl(tty, file, cmd, arg);
+ }
+}
+EXPORT_SYMBOL(n_tty_ioctl_helper);
--- /dev/null
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/devpts_fs.h>
+#include <linux/file.h>
+#include <linux/console.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/kd.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/seq_file.h>
+
+#include <linux/uaccess.h>
+#include <asm/system.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+
+#include <linux/smp_lock.h> /* For the moment */
+
+#include <linux/kmod.h>
+#include <linux/nsproxy.h>
+
+/*
+ * This guards the refcounted line discipline lists. The lock
+ * must be taken with irqs off because there are hangup path
+ * callers who will do ldisc lookups and cannot sleep.
+ */
+
+static DEFINE_SPINLOCK(tty_ldisc_lock);
+static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
+/* Line disc dispatch table */
+static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
+
+static inline struct tty_ldisc *get_ldisc(struct tty_ldisc *ld)
+{
+ if (ld)
+ atomic_inc(&ld->users);
+ return ld;
+}
+
+static void put_ldisc(struct tty_ldisc *ld)
+{
+ unsigned long flags;
+
+ if (WARN_ON_ONCE(!ld))
+ return;
+
+ /*
+ * If this is the last user, free the ldisc, and
+ * release the ldisc ops.
+ *
+ * We really want an "atomic_dec_and_lock_irqsave()",
+ * but we don't have it, so this does it by hand.
+ */
+ local_irq_save(flags);
+ if (atomic_dec_and_lock(&ld->users, &tty_ldisc_lock)) {
+ struct tty_ldisc_ops *ldo = ld->ops;
+
+ ldo->refcount--;
+ module_put(ldo->owner);
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+ kfree(ld);
+ return;
+ }
+ local_irq_restore(flags);
+}
+
+/**
+ * tty_register_ldisc - install a line discipline
+ * @disc: ldisc number
+ * @new_ldisc: pointer to the ldisc object
+ *
+ * Installs a new line discipline into the kernel. The discipline
+ * is set up as unreferenced and then made available to the kernel
+ * from this point onwards.
+ *
+ * Locking:
+ * takes tty_ldisc_lock to guard against ldisc races
+ */
+
+int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ if (disc < N_TTY || disc >= NR_LDISCS)
+ return -EINVAL;
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ tty_ldiscs[disc] = new_ldisc;
+ new_ldisc->num = disc;
+ new_ldisc->refcount = 0;
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(tty_register_ldisc);
+
+/**
+ * tty_unregister_ldisc - unload a line discipline
+ * @disc: ldisc number
+ * @new_ldisc: pointer to the ldisc object
+ *
+ * Remove a line discipline from the kernel providing it is not
+ * currently in use.
+ *
+ * Locking:
+ * takes tty_ldisc_lock to guard against ldisc races
+ */
+
+int tty_unregister_ldisc(int disc)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ if (disc < N_TTY || disc >= NR_LDISCS)
+ return -EINVAL;
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ if (tty_ldiscs[disc]->refcount)
+ ret = -EBUSY;
+ else
+ tty_ldiscs[disc] = NULL;
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(tty_unregister_ldisc);
+
+static struct tty_ldisc_ops *get_ldops(int disc)
+{
+ unsigned long flags;
+ struct tty_ldisc_ops *ldops, *ret;
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ ret = ERR_PTR(-EINVAL);
+ ldops = tty_ldiscs[disc];
+ if (ldops) {
+ ret = ERR_PTR(-EAGAIN);
+ if (try_module_get(ldops->owner)) {
+ ldops->refcount++;
+ ret = ldops;
+ }
+ }
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+ return ret;
+}
+
+static void put_ldops(struct tty_ldisc_ops *ldops)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ ldops->refcount--;
+ module_put(ldops->owner);
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+}
+
+/**
+ * tty_ldisc_get - take a reference to an ldisc
+ * @disc: ldisc number
+ *
+ * Takes a reference to a line discipline. Deals with refcounts and
+ * module locking counts. Returns NULL if the discipline is not available.
+ * Returns a pointer to the discipline and bumps the ref count if it is
+ * available
+ *
+ * Locking:
+ * takes tty_ldisc_lock to guard against ldisc races
+ */
+
+static struct tty_ldisc *tty_ldisc_get(int disc)
+{
+ struct tty_ldisc *ld;
+ struct tty_ldisc_ops *ldops;
+
+ if (disc < N_TTY || disc >= NR_LDISCS)
+ return ERR_PTR(-EINVAL);
+
+ /*
+ * Get the ldisc ops - we may need to request them to be loaded
+ * dynamically and try again.
+ */
+ ldops = get_ldops(disc);
+ if (IS_ERR(ldops)) {
+ request_module("tty-ldisc-%d", disc);
+ ldops = get_ldops(disc);
+ if (IS_ERR(ldops))
+ return ERR_CAST(ldops);
+ }
+
+ ld = kmalloc(sizeof(struct tty_ldisc), GFP_KERNEL);
+ if (ld == NULL) {
+ put_ldops(ldops);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ ld->ops = ldops;
+ atomic_set(&ld->users, 1);
+ return ld;
+}
+
+static void *tty_ldiscs_seq_start(struct seq_file *m, loff_t *pos)
+{
+ return (*pos < NR_LDISCS) ? pos : NULL;
+}
+
+static void *tty_ldiscs_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ (*pos)++;
+ return (*pos < NR_LDISCS) ? pos : NULL;
+}
+
+static void tty_ldiscs_seq_stop(struct seq_file *m, void *v)
+{
+}
+
+static int tty_ldiscs_seq_show(struct seq_file *m, void *v)
+{
+ int i = *(loff_t *)v;
+ struct tty_ldisc_ops *ldops;
+
+ ldops = get_ldops(i);
+ if (IS_ERR(ldops))
+ return 0;
+ seq_printf(m, "%-10s %2d\n", ldops->name ? ldops->name : "???", i);
+ put_ldops(ldops);
+ return 0;
+}
+
+static const struct seq_operations tty_ldiscs_seq_ops = {
+ .start = tty_ldiscs_seq_start,
+ .next = tty_ldiscs_seq_next,
+ .stop = tty_ldiscs_seq_stop,
+ .show = tty_ldiscs_seq_show,
+};
+
+static int proc_tty_ldiscs_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &tty_ldiscs_seq_ops);
+}
+
+const struct file_operations tty_ldiscs_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = proc_tty_ldiscs_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+/**
+ * tty_ldisc_assign - set ldisc on a tty
+ * @tty: tty to assign
+ * @ld: line discipline
+ *
+ * Install an instance of a line discipline into a tty structure. The
+ * ldisc must have a reference count above zero to ensure it remains.
+ * The tty instance refcount starts at zero.
+ *
+ * Locking:
+ * Caller must hold references
+ */
+
+static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+ tty->ldisc = ld;
+}
+
+/**
+ * tty_ldisc_try - internal helper
+ * @tty: the tty
+ *
+ * Make a single attempt to grab and bump the refcount on
+ * the tty ldisc. Return 0 on failure or 1 on success. This is
+ * used to implement both the waiting and non waiting versions
+ * of tty_ldisc_ref
+ *
+ * Locking: takes tty_ldisc_lock
+ */
+
+static struct tty_ldisc *tty_ldisc_try(struct tty_struct *tty)
+{
+ unsigned long flags;
+ struct tty_ldisc *ld;
+
+ spin_lock_irqsave(&tty_ldisc_lock, flags);
+ ld = NULL;
+ if (test_bit(TTY_LDISC, &tty->flags))
+ ld = get_ldisc(tty->ldisc);
+ spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+ return ld;
+}
+
+/**
+ * tty_ldisc_ref_wait - wait for the tty ldisc
+ * @tty: tty device
+ *
+ * Dereference the line discipline for the terminal and take a
+ * reference to it. If the line discipline is in flux then
+ * wait patiently until it changes.
+ *
+ * Note: Must not be called from an IRQ/timer context. The caller
+ * must also be careful not to hold other locks that will deadlock
+ * against a discipline change, such as an existing ldisc reference
+ * (which we check for)
+ *
+ * Locking: call functions take tty_ldisc_lock
+ */
+
+struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
+{
+ struct tty_ldisc *ld;
+
+ /* wait_event is a macro */
+ wait_event(tty_ldisc_wait, (ld = tty_ldisc_try(tty)) != NULL);
+ return ld;
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
+
+/**
+ * tty_ldisc_ref - get the tty ldisc
+ * @tty: tty device
+ *
+ * Dereference the line discipline for the terminal and take a
+ * reference to it. If the line discipline is in flux then
+ * return NULL. Can be called from IRQ and timer functions.
+ *
+ * Locking: called functions take tty_ldisc_lock
+ */
+
+struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
+{
+ return tty_ldisc_try(tty);
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_ref);
+
+/**
+ * tty_ldisc_deref - free a tty ldisc reference
+ * @ld: reference to free up
+ *
+ * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May
+ * be called in IRQ context.
+ *
+ * Locking: takes tty_ldisc_lock
+ */
+
+void tty_ldisc_deref(struct tty_ldisc *ld)
+{
+ put_ldisc(ld);
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_deref);
+
+static inline void tty_ldisc_put(struct tty_ldisc *ld)
+{
+ put_ldisc(ld);
+}
+
+/**
+ * tty_ldisc_enable - allow ldisc use
+ * @tty: terminal to activate ldisc on
+ *
+ * Set the TTY_LDISC flag when the line discipline can be called
+ * again. Do necessary wakeups for existing sleepers. Clear the LDISC
+ * changing flag to indicate any ldisc change is now over.
+ *
+ * Note: nobody should set the TTY_LDISC bit except via this function.
+ * Clearing directly is allowed.
+ */
+
+void tty_ldisc_enable(struct tty_struct *tty)
+{
+ set_bit(TTY_LDISC, &tty->flags);
+ clear_bit(TTY_LDISC_CHANGING, &tty->flags);
+ wake_up(&tty_ldisc_wait);
+}
+
+/**
+ * tty_ldisc_flush - flush line discipline queue
+ * @tty: tty
+ *
+ * Flush the line discipline queue (if any) for this tty. If there
+ * is no line discipline active this is a no-op.
+ */
+
+void tty_ldisc_flush(struct tty_struct *tty)
+{
+ struct tty_ldisc *ld = tty_ldisc_ref(tty);
+ if (ld) {
+ if (ld->ops->flush_buffer)
+ ld->ops->flush_buffer(tty);
+ tty_ldisc_deref(ld);
+ }
+ tty_buffer_flush(tty);
+}
+EXPORT_SYMBOL_GPL(tty_ldisc_flush);
+
+/**
+ * tty_set_termios_ldisc - set ldisc field
+ * @tty: tty structure
+ * @num: line discipline number
+ *
+ * This is probably overkill for real world processors but
+ * they are not on hot paths so a little discipline won't do
+ * any harm.
+ *
+ * Locking: takes termios_mutex
+ */
+
+static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
+{
+ mutex_lock(&tty->termios_mutex);
+ tty->termios->c_line = num;
+ mutex_unlock(&tty->termios_mutex);
+}
+
+/**
+ * tty_ldisc_open - open a line discipline
+ * @tty: tty we are opening the ldisc on
+ * @ld: discipline to open
+ *
+ * A helper opening method. Also a convenient debugging and check
+ * point.
+ *
+ * Locking: always called with BTM already held.
+ */
+
+static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+ WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));
+ if (ld->ops->open) {
+ int ret;
+ /* BTM here locks versus a hangup event */
+ WARN_ON(!tty_locked());
+ ret = ld->ops->open(tty);
+ return ret;
+ }
+ return 0;
+}
+
+/**
+ * tty_ldisc_close - close a line discipline
+ * @tty: tty we are opening the ldisc on
+ * @ld: discipline to close
+ *
+ * A helper close method. Also a convenient debugging and check
+ * point.
+ */
+
+static void tty_ldisc_close(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+ WARN_ON(!test_bit(TTY_LDISC_OPEN, &tty->flags));
+ clear_bit(TTY_LDISC_OPEN, &tty->flags);
+ if (ld->ops->close)
+ ld->ops->close(tty);
+}
+
+/**
+ * tty_ldisc_restore - helper for tty ldisc change
+ * @tty: tty to recover
+ * @old: previous ldisc
+ *
+ * Restore the previous line discipline or N_TTY when a line discipline
+ * change fails due to an open error
+ */
+
+static void tty_ldisc_restore(struct tty_struct *tty, struct tty_ldisc *old)
+{
+ char buf[64];
+ struct tty_ldisc *new_ldisc;
+ int r;
+
+ /* There is an outstanding reference here so this is safe */
+ old = tty_ldisc_get(old->ops->num);
+ WARN_ON(IS_ERR(old));
+ tty_ldisc_assign(tty, old);
+ tty_set_termios_ldisc(tty, old->ops->num);
+ if (tty_ldisc_open(tty, old) < 0) {
+ tty_ldisc_put(old);
+ /* This driver is always present */
+ new_ldisc = tty_ldisc_get(N_TTY);
+ if (IS_ERR(new_ldisc))
+ panic("n_tty: get");
+ tty_ldisc_assign(tty, new_ldisc);
+ tty_set_termios_ldisc(tty, N_TTY);
+ r = tty_ldisc_open(tty, new_ldisc);
+ if (r < 0)
+ panic("Couldn't open N_TTY ldisc for "
+ "%s --- error %d.",
+ tty_name(tty, buf), r);
+ }
+}
+
+/**
+ * tty_ldisc_halt - shut down the line discipline
+ * @tty: tty device
+ *
+ * Shut down the line discipline and work queue for this tty device.
+ * The TTY_LDISC flag being cleared ensures no further references can
+ * be obtained while the delayed work queue halt ensures that no more
+ * data is fed to the ldisc.
+ *
+ * You need to do a 'flush_scheduled_work()' (outside the ldisc_mutex)
+ * in order to make sure any currently executing ldisc work is also
+ * flushed.
+ */
+
+static int tty_ldisc_halt(struct tty_struct *tty)
+{
+ clear_bit(TTY_LDISC, &tty->flags);
+ return cancel_delayed_work_sync(&tty->buf.work);
+}
+
+/**
+ * tty_set_ldisc - set line discipline
+ * @tty: the terminal to set
+ * @ldisc: the line discipline
+ *
+ * Set the discipline of a tty line. Must be called from a process
+ * context. The ldisc change logic has to protect itself against any
+ * overlapping ldisc change (including on the other end of pty pairs),
+ * the close of one side of a tty/pty pair, and eventually hangup.
+ *
+ * Locking: takes tty_ldisc_lock, termios_mutex
+ */
+
+int tty_set_ldisc(struct tty_struct *tty, int ldisc)
+{
+ int retval;
+ struct tty_ldisc *o_ldisc, *new_ldisc;
+ int work, o_work = 0;
+ struct tty_struct *o_tty;
+
+ new_ldisc = tty_ldisc_get(ldisc);
+ if (IS_ERR(new_ldisc))
+ return PTR_ERR(new_ldisc);
+
+ tty_lock();
+ /*
+ * We need to look at the tty locking here for pty/tty pairs
+ * when both sides try to change in parallel.
+ */
+
+ o_tty = tty->link; /* o_tty is the pty side or NULL */
+
+
+ /*
+ * Check the no-op case
+ */
+
+ if (tty->ldisc->ops->num == ldisc) {
+ tty_unlock();
+ tty_ldisc_put(new_ldisc);
+ return 0;
+ }
+
+ tty_unlock();
+ /*
+ * Problem: What do we do if this blocks ?
+ * We could deadlock here
+ */
+
+ tty_wait_until_sent(tty, 0);
+
+ tty_lock();
+ mutex_lock(&tty->ldisc_mutex);
+
+ /*
+ * We could be midstream of another ldisc change which has
+ * dropped the lock during processing. If so we need to wait.
+ */
+
+ while (test_bit(TTY_LDISC_CHANGING, &tty->flags)) {
+ mutex_unlock(&tty->ldisc_mutex);
+ tty_unlock();
+ wait_event(tty_ldisc_wait,
+ test_bit(TTY_LDISC_CHANGING, &tty->flags) == 0);
+ tty_lock();
+ mutex_lock(&tty->ldisc_mutex);
+ }
+
+ set_bit(TTY_LDISC_CHANGING, &tty->flags);
+
+ /*
+ * No more input please, we are switching. The new ldisc
+ * will update this value in the ldisc open function
+ */
+
+ tty->receive_room = 0;
+
+ o_ldisc = tty->ldisc;
+
+ tty_unlock();
+ /*
+ * Make sure we don't change while someone holds a
+ * reference to the line discipline. The TTY_LDISC bit
+ * prevents anyone taking a reference once it is clear.
+ * We need the lock to avoid racing reference takers.
+ *
+ * We must clear the TTY_LDISC bit here to avoid a livelock
+ * with a userspace app continually trying to use the tty in
+ * parallel to the change and re-referencing the tty.
+ */
+
+ work = tty_ldisc_halt(tty);
+ if (o_tty)
+ o_work = tty_ldisc_halt(o_tty);
+
+ /*
+ * Wait for ->hangup_work and ->buf.work handlers to terminate.
+ * We must drop the mutex here in case a hangup is also in process.
+ */
+
+ mutex_unlock(&tty->ldisc_mutex);
+
+ flush_scheduled_work();
+
+ tty_lock();
+ mutex_lock(&tty->ldisc_mutex);
+ if (test_bit(TTY_HUPPED, &tty->flags)) {
+ /* We were raced by the hangup method. It will have stomped
+ the ldisc data and closed the ldisc down */
+ clear_bit(TTY_LDISC_CHANGING, &tty->flags);
+ mutex_unlock(&tty->ldisc_mutex);
+ tty_ldisc_put(new_ldisc);
+ tty_unlock();
+ return -EIO;
+ }
+
+ /* Shutdown the current discipline. */
+ tty_ldisc_close(tty, o_ldisc);
+
+ /* Now set up the new line discipline. */
+ tty_ldisc_assign(tty, new_ldisc);
+ tty_set_termios_ldisc(tty, ldisc);
+
+ retval = tty_ldisc_open(tty, new_ldisc);
+ if (retval < 0) {
+ /* Back to the old one or N_TTY if we can't */
+ tty_ldisc_put(new_ldisc);
+ tty_ldisc_restore(tty, o_ldisc);
+ }
+
+ /* At this point we hold a reference to the new ldisc and a
+ a reference to the old ldisc. If we ended up flipping back
+ to the existing ldisc we have two references to it */
+
+ if (tty->ldisc->ops->num != o_ldisc->ops->num && tty->ops->set_ldisc)
+ tty->ops->set_ldisc(tty);
+
+ tty_ldisc_put(o_ldisc);
+
+ /*
+ * Allow ldisc referencing to occur again
+ */
+
+ tty_ldisc_enable(tty);
+ if (o_tty)
+ tty_ldisc_enable(o_tty);
+
+ /* Restart the work queue in case no characters kick it off. Safe if
+ already running */
+ if (work)
+ schedule_delayed_work(&tty->buf.work, 1);
+ if (o_work)
+ schedule_delayed_work(&o_tty->buf.work, 1);
+ mutex_unlock(&tty->ldisc_mutex);
+ tty_unlock();
+ return retval;
+}
+
+/**
+ * tty_reset_termios - reset terminal state
+ * @tty: tty to reset
+ *
+ * Restore a terminal to the driver default state.
+ */
+
+static void tty_reset_termios(struct tty_struct *tty)
+{
+ mutex_lock(&tty->termios_mutex);
+ *tty->termios = tty->driver->init_termios;
+ tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+ tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+ mutex_unlock(&tty->termios_mutex);
+}
+
+
+/**
+ * tty_ldisc_reinit - reinitialise the tty ldisc
+ * @tty: tty to reinit
+ * @ldisc: line discipline to reinitialize
+ *
+ * Switch the tty to a line discipline and leave the ldisc
+ * state closed
+ */
+
+static void tty_ldisc_reinit(struct tty_struct *tty, int ldisc)
+{
+ struct tty_ldisc *ld;
+
+ tty_ldisc_close(tty, tty->ldisc);
+ tty_ldisc_put(tty->ldisc);
+ tty->ldisc = NULL;
+ /*
+ * Switch the line discipline back
+ */
+ ld = tty_ldisc_get(ldisc);
+ BUG_ON(IS_ERR(ld));
+ tty_ldisc_assign(tty, ld);
+ tty_set_termios_ldisc(tty, ldisc);
+}
+
+/**
+ * tty_ldisc_hangup - hangup ldisc reset
+ * @tty: tty being hung up
+ *
+ * Some tty devices reset their termios when they receive a hangup
+ * event. In that situation we must also switch back to N_TTY properly
+ * before we reset the termios data.
+ *
+ * Locking: We can take the ldisc mutex as the rest of the code is
+ * careful to allow for this.
+ *
+ * In the pty pair case this occurs in the close() path of the
+ * tty itself so we must be careful about locking rules.
+ */
+
+void tty_ldisc_hangup(struct tty_struct *tty)
+{
+ struct tty_ldisc *ld;
+ int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
+ int err = 0;
+
+ /*
+ * FIXME! What are the locking issues here? This may me overdoing
+ * things... This question is especially important now that we've
+ * removed the irqlock.
+ */
+ ld = tty_ldisc_ref(tty);
+ if (ld != NULL) {
+ /* We may have no line discipline at this point */
+ if (ld->ops->flush_buffer)
+ ld->ops->flush_buffer(tty);
+ tty_driver_flush_buffer(tty);
+ if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
+ ld->ops->write_wakeup)
+ ld->ops->write_wakeup(tty);
+ if (ld->ops->hangup)
+ ld->ops->hangup(tty);
+ tty_ldisc_deref(ld);
+ }
+ /*
+ * FIXME: Once we trust the LDISC code better we can wait here for
+ * ldisc completion and fix the driver call race
+ */
+ wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+ wake_up_interruptible_poll(&tty->read_wait, POLLIN);
+ /*
+ * Shutdown the current line discipline, and reset it to
+ * N_TTY if need be.
+ *
+ * Avoid racing set_ldisc or tty_ldisc_release
+ */
+ mutex_lock(&tty->ldisc_mutex);
+
+ /*
+ * this is like tty_ldisc_halt, but we need to give up
+ * the BTM before calling cancel_delayed_work_sync,
+ * which may need to wait for another function taking the BTM
+ */
+ clear_bit(TTY_LDISC, &tty->flags);
+ tty_unlock();
+ cancel_delayed_work_sync(&tty->buf.work);
+ mutex_unlock(&tty->ldisc_mutex);
+
+ tty_lock();
+ mutex_lock(&tty->ldisc_mutex);
+
+ /* At this point we have a closed ldisc and we want to
+ reopen it. We could defer this to the next open but
+ it means auditing a lot of other paths so this is
+ a FIXME */
+ if (tty->ldisc) { /* Not yet closed */
+ if (reset == 0) {
+ tty_ldisc_reinit(tty, tty->termios->c_line);
+ err = tty_ldisc_open(tty, tty->ldisc);
+ }
+ /* If the re-open fails or we reset then go to N_TTY. The
+ N_TTY open cannot fail */
+ if (reset || err) {
+ tty_ldisc_reinit(tty, N_TTY);
+ WARN_ON(tty_ldisc_open(tty, tty->ldisc));
+ }
+ tty_ldisc_enable(tty);
+ }
+ mutex_unlock(&tty->ldisc_mutex);
+ if (reset)
+ tty_reset_termios(tty);
+}
+
+/**
+ * tty_ldisc_setup - open line discipline
+ * @tty: tty being shut down
+ * @o_tty: pair tty for pty/tty pairs
+ *
+ * Called during the initial open of a tty/pty pair in order to set up the
+ * line disciplines and bind them to the tty. This has no locking issues
+ * as the device isn't yet active.
+ */
+
+int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty)
+{
+ struct tty_ldisc *ld = tty->ldisc;
+ int retval;
+
+ retval = tty_ldisc_open(tty, ld);
+ if (retval)
+ return retval;
+
+ if (o_tty) {
+ retval = tty_ldisc_open(o_tty, o_tty->ldisc);
+ if (retval) {
+ tty_ldisc_close(tty, ld);
+ return retval;
+ }
+ tty_ldisc_enable(o_tty);
+ }
+ tty_ldisc_enable(tty);
+ return 0;
+}
+/**
+ * tty_ldisc_release - release line discipline
+ * @tty: tty being shut down
+ * @o_tty: pair tty for pty/tty pairs
+ *
+ * Called during the final close of a tty/pty pair in order to shut down
+ * the line discpline layer. On exit the ldisc assigned is N_TTY and the
+ * ldisc has not been opened.
+ */
+
+void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
+{
+ /*
+ * Prevent flush_to_ldisc() from rescheduling the work for later. Then
+ * kill any delayed work. As this is the final close it does not
+ * race with the set_ldisc code path.
+ */
+
+ tty_unlock();
+ tty_ldisc_halt(tty);
+ flush_scheduled_work();
+ tty_lock();
+
+ mutex_lock(&tty->ldisc_mutex);
+ /*
+ * Now kill off the ldisc
+ */
+ tty_ldisc_close(tty, tty->ldisc);
+ tty_ldisc_put(tty->ldisc);
+ /* Force an oops if we mess this up */
+ tty->ldisc = NULL;
+
+ /* Ensure the next open requests the N_TTY ldisc */
+ tty_set_termios_ldisc(tty, N_TTY);
+ mutex_unlock(&tty->ldisc_mutex);
+
+ /* This will need doing differently if we need to lock */
+ if (o_tty)
+ tty_ldisc_release(o_tty, NULL);
+
+ /* And the memory resources remaining (buffers, termios) will be
+ disposed of when the kref hits zero */
+}
+
+/**
+ * tty_ldisc_init - ldisc setup for new tty
+ * @tty: tty being allocated
+ *
+ * Set up the line discipline objects for a newly allocated tty. Note that
+ * the tty structure is not completely set up when this call is made.
+ */
+
+void tty_ldisc_init(struct tty_struct *tty)
+{
+ struct tty_ldisc *ld = tty_ldisc_get(N_TTY);
+ if (IS_ERR(ld))
+ panic("n_tty: init_tty");
+ tty_ldisc_assign(tty, ld);
+}
+
+void tty_ldisc_begin(void)
+{
+ /* Setup the default TTY line discipline. */
+ (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
+}
--- /dev/null
+/*
+ * drivers/char/tty_lock.c
+ */
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/semaphore.h>
+#include <linux/sched.h>
+
+/*
+ * The 'big tty mutex'
+ *
+ * This mutex is taken and released by tty_lock() and tty_unlock(),
+ * replacing the older big kernel lock.
+ * It can no longer be taken recursively, and does not get
+ * released implicitly while sleeping.
+ *
+ * Don't use in new code.
+ */
+static DEFINE_MUTEX(big_tty_mutex);
+struct task_struct *__big_tty_mutex_owner;
+EXPORT_SYMBOL_GPL(__big_tty_mutex_owner);
+
+/*
+ * Getting the big tty mutex.
+ */
+void __lockfunc tty_lock(void)
+{
+ struct task_struct *task = current;
+
+ WARN_ON(__big_tty_mutex_owner == task);
+
+ mutex_lock(&big_tty_mutex);
+ __big_tty_mutex_owner = task;
+}
+EXPORT_SYMBOL(tty_lock);
+
+void __lockfunc tty_unlock(void)
+{
+ struct task_struct *task = current;
+
+ WARN_ON(__big_tty_mutex_owner != task);
+ __big_tty_mutex_owner = NULL;
+
+ mutex_unlock(&big_tty_mutex);
+}
+EXPORT_SYMBOL(tty_unlock);
--- /dev/null
+/*
+ * Tty port functions
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+void tty_port_init(struct tty_port *port)
+{
+ memset(port, 0, sizeof(*port));
+ init_waitqueue_head(&port->open_wait);
+ init_waitqueue_head(&port->close_wait);
+ init_waitqueue_head(&port->delta_msr_wait);
+ mutex_init(&port->mutex);
+ mutex_init(&port->buf_mutex);
+ spin_lock_init(&port->lock);
+ port->close_delay = (50 * HZ) / 100;
+ port->closing_wait = (3000 * HZ) / 100;
+ kref_init(&port->kref);
+}
+EXPORT_SYMBOL(tty_port_init);
+
+int tty_port_alloc_xmit_buf(struct tty_port *port)
+{
+ /* We may sleep in get_zeroed_page() */
+ mutex_lock(&port->buf_mutex);
+ if (port->xmit_buf == NULL)
+ port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
+ mutex_unlock(&port->buf_mutex);
+ if (port->xmit_buf == NULL)
+ return -ENOMEM;
+ return 0;
+}
+EXPORT_SYMBOL(tty_port_alloc_xmit_buf);
+
+void tty_port_free_xmit_buf(struct tty_port *port)
+{
+ mutex_lock(&port->buf_mutex);
+ if (port->xmit_buf != NULL) {
+ free_page((unsigned long)port->xmit_buf);
+ port->xmit_buf = NULL;
+ }
+ mutex_unlock(&port->buf_mutex);
+}
+EXPORT_SYMBOL(tty_port_free_xmit_buf);
+
+static void tty_port_destructor(struct kref *kref)
+{
+ struct tty_port *port = container_of(kref, struct tty_port, kref);
+ if (port->xmit_buf)
+ free_page((unsigned long)port->xmit_buf);
+ if (port->ops->destruct)
+ port->ops->destruct(port);
+ else
+ kfree(port);
+}
+
+void tty_port_put(struct tty_port *port)
+{
+ if (port)
+ kref_put(&port->kref, tty_port_destructor);
+}
+EXPORT_SYMBOL(tty_port_put);
+
+/**
+ * tty_port_tty_get - get a tty reference
+ * @port: tty port
+ *
+ * Return a refcount protected tty instance or NULL if the port is not
+ * associated with a tty (eg due to close or hangup)
+ */
+
+struct tty_struct *tty_port_tty_get(struct tty_port *port)
+{
+ unsigned long flags;
+ struct tty_struct *tty;
+
+ spin_lock_irqsave(&port->lock, flags);
+ tty = tty_kref_get(port->tty);
+ spin_unlock_irqrestore(&port->lock, flags);
+ return tty;
+}
+EXPORT_SYMBOL(tty_port_tty_get);
+
+/**
+ * tty_port_tty_set - set the tty of a port
+ * @port: tty port
+ * @tty: the tty
+ *
+ * Associate the port and tty pair. Manages any internal refcounts.
+ * Pass NULL to deassociate a port
+ */
+
+void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ if (port->tty)
+ tty_kref_put(port->tty);
+ port->tty = tty_kref_get(tty);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+EXPORT_SYMBOL(tty_port_tty_set);
+
+static void tty_port_shutdown(struct tty_port *port)
+{
+ mutex_lock(&port->mutex);
+ if (port->ops->shutdown && !port->console &&
+ test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags))
+ port->ops->shutdown(port);
+ mutex_unlock(&port->mutex);
+}
+
+/**
+ * tty_port_hangup - hangup helper
+ * @port: tty port
+ *
+ * Perform port level tty hangup flag and count changes. Drop the tty
+ * reference.
+ */
+
+void tty_port_hangup(struct tty_port *port)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ port->count = 0;
+ port->flags &= ~ASYNC_NORMAL_ACTIVE;
+ if (port->tty) {
+ set_bit(TTY_IO_ERROR, &port->tty->flags);
+ tty_kref_put(port->tty);
+ }
+ port->tty = NULL;
+ spin_unlock_irqrestore(&port->lock, flags);
+ wake_up_interruptible(&port->open_wait);
+ wake_up_interruptible(&port->delta_msr_wait);
+ tty_port_shutdown(port);
+}
+EXPORT_SYMBOL(tty_port_hangup);
+
+/**
+ * tty_port_carrier_raised - carrier raised check
+ * @port: tty port
+ *
+ * Wrapper for the carrier detect logic. For the moment this is used
+ * to hide some internal details. This will eventually become entirely
+ * internal to the tty port.
+ */
+
+int tty_port_carrier_raised(struct tty_port *port)
+{
+ if (port->ops->carrier_raised == NULL)
+ return 1;
+ return port->ops->carrier_raised(port);
+}
+EXPORT_SYMBOL(tty_port_carrier_raised);
+
+/**
+ * tty_port_raise_dtr_rts - Raise DTR/RTS
+ * @port: tty port
+ *
+ * Wrapper for the DTR/RTS raise logic. For the moment this is used
+ * to hide some internal details. This will eventually become entirely
+ * internal to the tty port.
+ */
+
+void tty_port_raise_dtr_rts(struct tty_port *port)
+{
+ if (port->ops->dtr_rts)
+ port->ops->dtr_rts(port, 1);
+}
+EXPORT_SYMBOL(tty_port_raise_dtr_rts);
+
+/**
+ * tty_port_lower_dtr_rts - Lower DTR/RTS
+ * @port: tty port
+ *
+ * Wrapper for the DTR/RTS raise logic. For the moment this is used
+ * to hide some internal details. This will eventually become entirely
+ * internal to the tty port.
+ */
+
+void tty_port_lower_dtr_rts(struct tty_port *port)
+{
+ if (port->ops->dtr_rts)
+ port->ops->dtr_rts(port, 0);
+}
+EXPORT_SYMBOL(tty_port_lower_dtr_rts);
+
+/**
+ * tty_port_block_til_ready - Waiting logic for tty open
+ * @port: the tty port being opened
+ * @tty: the tty device being bound
+ * @filp: the file pointer of the opener
+ *
+ * Implement the core POSIX/SuS tty behaviour when opening a tty device.
+ * Handles:
+ * - hangup (both before and during)
+ * - non blocking open
+ * - rts/dtr/dcd
+ * - signals
+ * - port flags and counts
+ *
+ * The passed tty_port must implement the carrier_raised method if it can
+ * do carrier detect and the dtr_rts method if it supports software
+ * management of these lines. Note that the dtr/rts raise is done each
+ * iteration as a hangup may have previously dropped them while we wait.
+ */
+
+int tty_port_block_til_ready(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp)
+{
+ int do_clocal = 0, retval;
+ unsigned long flags;
+ DEFINE_WAIT(wait);
+ int cd;
+
+ /* block if port is in the process of being closed */
+ if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
+ wait_event_interruptible_tty(port->close_wait,
+ !(port->flags & ASYNC_CLOSING));
+ if (port->flags & ASYNC_HUP_NOTIFY)
+ return -EAGAIN;
+ else
+ return -ERESTARTSYS;
+ }
+
+ /* if non-blocking mode is set we can pass directly to open unless
+ the port has just hung up or is in another error state */
+ if (tty->flags & (1 << TTY_IO_ERROR)) {
+ port->flags |= ASYNC_NORMAL_ACTIVE;
+ return 0;
+ }
+ if (filp->f_flags & O_NONBLOCK) {
+ /* Indicate we are open */
+ if (tty->termios->c_cflag & CBAUD)
+ tty_port_raise_dtr_rts(port);
+ port->flags |= ASYNC_NORMAL_ACTIVE;
+ return 0;
+ }
+
+ if (C_CLOCAL(tty))
+ do_clocal = 1;
+
+ /* Block waiting until we can proceed. We may need to wait for the
+ carrier, but we must also wait for any close that is in progress
+ before the next open may complete */
+
+ retval = 0;
+
+ /* The port lock protects the port counts */
+ spin_lock_irqsave(&port->lock, flags);
+ if (!tty_hung_up_p(filp))
+ port->count--;
+ port->blocked_open++;
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ while (1) {
+ /* Indicate we are open */
+ if (tty->termios->c_cflag & CBAUD)
+ tty_port_raise_dtr_rts(port);
+
+ prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);
+ /* Check for a hangup or uninitialised port.
+ Return accordingly */
+ if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) {
+ if (port->flags & ASYNC_HUP_NOTIFY)
+ retval = -EAGAIN;
+ else
+ retval = -ERESTARTSYS;
+ break;
+ }
+ /* Probe the carrier. For devices with no carrier detect this
+ will always return true */
+ cd = tty_port_carrier_raised(port);
+ if (!(port->flags & ASYNC_CLOSING) &&
+ (do_clocal || cd))
+ break;
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ break;
+ }
+ tty_unlock();
+ schedule();
+ tty_lock();
+ }
+ finish_wait(&port->open_wait, &wait);
+
+ /* Update counts. A parallel hangup will have set count to zero and
+ we must not mess that up further */
+ spin_lock_irqsave(&port->lock, flags);
+ if (!tty_hung_up_p(filp))
+ port->count++;
+ port->blocked_open--;
+ if (retval == 0)
+ port->flags |= ASYNC_NORMAL_ACTIVE;
+ spin_unlock_irqrestore(&port->lock, flags);
+ return retval;
+}
+EXPORT_SYMBOL(tty_port_block_til_ready);
+
+int tty_port_close_start(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ if (tty_hung_up_p(filp)) {
+ spin_unlock_irqrestore(&port->lock, flags);
+ return 0;
+ }
+
+ if (tty->count == 1 && port->count != 1) {
+ printk(KERN_WARNING
+ "tty_port_close_start: tty->count = 1 port count = %d.\n",
+ port->count);
+ port->count = 1;
+ }
+ if (--port->count < 0) {
+ printk(KERN_WARNING "tty_port_close_start: count = %d\n",
+ port->count);
+ port->count = 0;
+ }
+
+ if (port->count) {
+ spin_unlock_irqrestore(&port->lock, flags);
+ if (port->ops->drop)
+ port->ops->drop(port);
+ return 0;
+ }
+ set_bit(ASYNCB_CLOSING, &port->flags);
+ tty->closing = 1;
+ spin_unlock_irqrestore(&port->lock, flags);
+ /* Don't block on a stalled port, just pull the chain */
+ if (tty->flow_stopped)
+ tty_driver_flush_buffer(tty);
+ if (test_bit(ASYNCB_INITIALIZED, &port->flags) &&
+ port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
+ tty_wait_until_sent(tty, port->closing_wait);
+ if (port->drain_delay) {
+ unsigned int bps = tty_get_baud_rate(tty);
+ long timeout;
+
+ if (bps > 1200)
+ timeout = max_t(long,
+ (HZ * 10 * port->drain_delay) / bps, HZ / 10);
+ else
+ timeout = 2 * HZ;
+ schedule_timeout_interruptible(timeout);
+ }
+ /* Flush the ldisc buffering */
+ tty_ldisc_flush(tty);
+
+ /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to
+ hang up the line */
+ if (tty->termios->c_cflag & HUPCL)
+ tty_port_lower_dtr_rts(port);
+
+ /* Don't call port->drop for the last reference. Callers will want
+ to drop the last active reference in ->shutdown() or the tty
+ shutdown path */
+ return 1;
+}
+EXPORT_SYMBOL(tty_port_close_start);
+
+void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ tty->closing = 0;
+
+ if (port->blocked_open) {
+ spin_unlock_irqrestore(&port->lock, flags);
+ if (port->close_delay) {
+ msleep_interruptible(
+ jiffies_to_msecs(port->close_delay));
+ }
+ spin_lock_irqsave(&port->lock, flags);
+ wake_up_interruptible(&port->open_wait);
+ }
+ port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING);
+ wake_up_interruptible(&port->close_wait);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+EXPORT_SYMBOL(tty_port_close_end);
+
+void tty_port_close(struct tty_port *port, struct tty_struct *tty,
+ struct file *filp)
+{
+ if (tty_port_close_start(port, tty, filp) == 0)
+ return;
+ tty_port_shutdown(port);
+ set_bit(TTY_IO_ERROR, &tty->flags);
+ tty_port_close_end(port, tty);
+ tty_port_tty_set(port, NULL);
+}
+EXPORT_SYMBOL(tty_port_close);
+
+int tty_port_open(struct tty_port *port, struct tty_struct *tty,
+ struct file *filp)
+{
+ spin_lock_irq(&port->lock);
+ if (!tty_hung_up_p(filp))
+ ++port->count;
+ spin_unlock_irq(&port->lock);
+ tty_port_tty_set(port, tty);
+
+ /*
+ * Do the device-specific open only if the hardware isn't
+ * already initialized. Serialize open and shutdown using the
+ * port mutex.
+ */
+
+ mutex_lock(&port->mutex);
+
+ if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) {
+ clear_bit(TTY_IO_ERROR, &tty->flags);
+ if (port->ops->activate) {
+ int retval = port->ops->activate(port, tty);
+ if (retval) {
+ mutex_unlock(&port->mutex);
+ return retval;
+ }
+ }
+ set_bit(ASYNCB_INITIALIZED, &port->flags);
+ }
+ mutex_unlock(&port->mutex);
+ return tty_port_block_til_ready(port, tty, filp);
+}
+
+EXPORT_SYMBOL(tty_port_open);
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff