[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / netrom / nr_subr.c

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/slab.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <asm/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/netrom.h>

/*
 *	This routine purges all of the queues of frames.
 */
void nr_clear_queues(struct sock *sk)
{
	struct nr_sock *nr = nr_sk(sk);

	skb_queue_purge(&sk->sk_write_queue);
	skb_queue_purge(&nr->ack_queue);
	skb_queue_purge(&nr->reseq_queue);
	skb_queue_purge(&nr->frag_queue);
}

/*
 * This routine purges the input queue of those frames that have been
 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
 * SDL diagram.
 */
void nr_frames_acked(struct sock *sk, unsigned short nr)
{
	struct nr_sock *nrom = nr_sk(sk);
	struct sk_buff *skb;

	/*
	 * Remove all the ack-ed frames from the ack queue.
	 */
	if (nrom->va != nr) {
		while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) {
			skb = skb_dequeue(&nrom->ack_queue);
			kfree_skb(skb);
			nrom->va = (nrom->va + 1) % NR_MODULUS;
		}
	}
}

/*
 * Requeue all the un-ack-ed frames on the output queue to be picked
 * up by nr_kick called from the timer. This arrangement handles the
 * possibility of an empty output queue.
 */
void nr_requeue_frames(struct sock *sk)
{
	struct sk_buff *skb, *skb_prev = NULL;

	while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) {
		if (skb_prev == NULL)
			skb_queue_head(&sk->sk_write_queue, skb);
		else
			skb_append(skb_prev, skb, &sk->sk_write_queue);
		skb_prev = skb;
	}
}

/*
 *	Validate that the value of nr is between va and vs. Return true or
 *	false for testing.
 */
int nr_validate_nr(struct sock *sk, unsigned short nr)
{
	struct nr_sock *nrom = nr_sk(sk);
	unsigned short vc = nrom->va;

	while (vc != nrom->vs) {
		if (nr == vc) return 1;
		vc = (vc + 1) % NR_MODULUS;
	}

	return nr == nrom->vs;
}

/*
 *	Check that ns is within the receive window.
 */
int nr_in_rx_window(struct sock *sk, unsigned short ns)
{
	struct nr_sock *nr = nr_sk(sk);
	unsigned short vc = nr->vr;
	unsigned short vt = (nr->vl + nr->window) % NR_MODULUS;

	while (vc != vt) {
		if (ns == vc) return 1;
		vc = (vc + 1) % NR_MODULUS;
	}

	return 0;
}

/*
 *  This routine is called when the HDLC layer internally generates a
 *  control frame.
 */
void nr_write_internal(struct sock *sk, int frametype)
{
	struct nr_sock *nr = nr_sk(sk);
	struct sk_buff *skb;
	unsigned char  *dptr;
	int len, timeout;

	len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;

	switch (frametype & 0x0F) {
	case NR_CONNREQ:
		len += 17;
		break;
	case NR_CONNACK:
		len += (nr->bpqext) ? 2 : 1;
		break;
	case NR_DISCREQ:
	case NR_DISCACK:
	case NR_INFOACK:
		break;
	default:
		printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype);
		return;
	}

	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
		return;

	/*
	 *	Space for AX.25 and NET/ROM network header
	 */
	skb_reserve(skb, NR_NETWORK_LEN);

	dptr = skb_put(skb, skb_tailroom(skb));

	switch (frametype & 0x0F) {
	case NR_CONNREQ:
		timeout  = nr->t1 / HZ;
		*dptr++  = nr->my_index;
		*dptr++  = nr->my_id;
		*dptr++  = 0;
		*dptr++  = 0;
		*dptr++  = frametype;
		*dptr++  = nr->window;
		memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN);
		dptr[6] &= ~AX25_CBIT;
		dptr[6] &= ~AX25_EBIT;
		dptr[6] |= AX25_SSSID_SPARE;
		dptr    += AX25_ADDR_LEN;
		memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
		dptr[6] &= ~AX25_CBIT;
		dptr[6] &= ~AX25_EBIT;
		dptr[6] |= AX25_SSSID_SPARE;
		dptr    += AX25_ADDR_LEN;
		*dptr++  = timeout % 256;
		*dptr++  = timeout / 256;
		break;

	case NR_CONNACK:
		*dptr++ = nr->your_index;
		*dptr++ = nr->your_id;
		*dptr++ = nr->my_index;
		*dptr++ = nr->my_id;
		*dptr++ = frametype;
		*dptr++ = nr->window;
		if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
		break;

	case NR_DISCREQ:
	case NR_DISCACK:
		*dptr++ = nr->your_index;
		*dptr++ = nr->your_id;
		*dptr++ = 0;
		*dptr++ = 0;
		*dptr++ = frametype;
		break;

	case NR_INFOACK:
		*dptr++ = nr->your_index;
		*dptr++ = nr->your_id;
		*dptr++ = 0;
		*dptr++ = nr->vr;
		*dptr++ = frametype;
		break;
	}

	nr_transmit_buffer(sk, skb);
}

/*
 * This routine is called to send an error reply.
 */
void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags)
{
	struct sk_buff *skbn;
	unsigned char *dptr;
	int len;

	len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1;

	if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL)
		return;

	skb_reserve(skbn, 0);

	dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN);

	skb_copy_from_linear_data_offset(skb, 7, dptr, AX25_ADDR_LEN);
	dptr[6] &= ~AX25_CBIT;
	dptr[6] &= ~AX25_EBIT;
	dptr[6] |= AX25_SSSID_SPARE;
	dptr += AX25_ADDR_LEN;

	skb_copy_from_linear_data(skb, dptr, AX25_ADDR_LEN);
	dptr[6] &= ~AX25_CBIT;
	dptr[6] |= AX25_EBIT;
	dptr[6] |= AX25_SSSID_SPARE;
	dptr += AX25_ADDR_LEN;

	*dptr++ = sysctl_netrom_network_ttl_initialiser;

	if (mine) {
		*dptr++ = 0;
		*dptr++ = 0;
		*dptr++ = skb->data[15];
		*dptr++ = skb->data[16];
	} else {
		*dptr++ = skb->data[15];
		*dptr++ = skb->data[16];
		*dptr++ = 0;
		*dptr++ = 0;
	}

	*dptr++ = cmdflags;
	*dptr++ = 0;

	if (!nr_route_frame(skbn, NULL))
		kfree_skb(skbn);
}

void nr_disconnect(struct sock *sk, int reason)
{
	nr_stop_t1timer(sk);
	nr_stop_t2timer(sk);
	nr_stop_t4timer(sk);
	nr_stop_idletimer(sk);

	nr_clear_queues(sk);

	nr_sk(sk)->state = NR_STATE_0;

	sk->sk_state     = TCP_CLOSE;
	sk->sk_err       = reason;
	sk->sk_shutdown |= SEND_SHUTDOWN;

	if (!sock_flag(sk, SOCK_DEAD)) {
		sk->sk_state_change(sk);
		sock_set_flag(sk, SOCK_DEAD);
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License as published by
	4	* the Free Software Foundation; either version 2 of the License, or
	5	* (at your option) any later version.
	6	*
	7	* Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
	8	*/
	9	#include <linux/errno.h>
	10	#include <linux/types.h>
	11	#include <linux/socket.h>
	12	#include <linux/in.h>
	13	#include <linux/kernel.h>
1da177e4 LT	14	#include <linux/timer.h>
	15	#include <linux/string.h>
	16	#include <linux/sockios.h>
	17	#include <linux/net.h>
5a0e3ad6	18	#include <linux/slab.h>
1da177e4 LT	19	#include <net/ax25.h>
	20	#include <linux/inet.h>
	21	#include <linux/netdevice.h>
	22	#include <linux/skbuff.h>
	23	#include <net/sock.h>
c752f073	24	#include <net/tcp_states.h>
1da177e4	25	#include <asm/uaccess.h>
1da177e4 LT	26	#include <linux/fcntl.h>
	27	#include <linux/mm.h>
	28	#include <linux/interrupt.h>
	29	#include <net/netrom.h>
	30
	31	/*
	32	* This routine purges all of the queues of frames.
	33	*/
	34	void nr_clear_queues(struct sock *sk)
	35	{
	36	struct nr_sock *nr = nr_sk(sk);
	37
	38	skb_queue_purge(&sk->sk_write_queue);
	39	skb_queue_purge(&nr->ack_queue);
	40	skb_queue_purge(&nr->reseq_queue);
	41	skb_queue_purge(&nr->frag_queue);
	42	}
	43
	44	/*
	45	* This routine purges the input queue of those frames that have been
	46	* acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
	47	* SDL diagram.
	48	*/
	49	void nr_frames_acked(struct sock *sk, unsigned short nr)
	50	{
	51	struct nr_sock *nrom = nr_sk(sk);
	52	struct sk_buff *skb;
	53
	54	/*
	55	* Remove all the ack-ed frames from the ack queue.
	56	*/
	57	if (nrom->va != nr) {
	58	while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) {
5f8f59d6	59	skb = skb_dequeue(&nrom->ack_queue);
1da177e4 LT	60	kfree_skb(skb);
	61	nrom->va = (nrom->va + 1) % NR_MODULUS;
	62	}
	63	}
	64	}
	65
	66	/*
	67	* Requeue all the un-ack-ed frames on the output queue to be picked
	68	* up by nr_kick called from the timer. This arrangement handles the
	69	* possibility of an empty output queue.
	70	*/
	71	void nr_requeue_frames(struct sock *sk)
	72	{
	73	struct sk_buff skb, skb_prev = NULL;
	74
	75	while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) {
	76	if (skb_prev == NULL)
	77	skb_queue_head(&sk->sk_write_queue, skb);
	78	else
8728b834	79	skb_append(skb_prev, skb, &sk->sk_write_queue);
1da177e4 LT	80	skb_prev = skb;
	81	}
	82	}
	83
	84	/*
	85	* Validate that the value of nr is between va and vs. Return true or
	86	* false for testing.
	87	*/
	88	int nr_validate_nr(struct sock *sk, unsigned short nr)
	89	{
	90	struct nr_sock *nrom = nr_sk(sk);
	91	unsigned short vc = nrom->va;
	92
	93	while (vc != nrom->vs) {
	94	if (nr == vc) return 1;
	95	vc = (vc + 1) % NR_MODULUS;
	96	}
	97
	98	return nr == nrom->vs;
	99	}
	100
	101	/*
	102	* Check that ns is within the receive window.
	103	*/
	104	int nr_in_rx_window(struct sock *sk, unsigned short ns)
	105	{
	106	struct nr_sock *nr = nr_sk(sk);
	107	unsigned short vc = nr->vr;
	108	unsigned short vt = (nr->vl + nr->window) % NR_MODULUS;
	109
	110	while (vc != vt) {
	111	if (ns == vc) return 1;
	112	vc = (vc + 1) % NR_MODULUS;
	113	}
	114
	115	return 0;
	116	}
	117
	118	/*
	119	* This routine is called when the HDLC layer internally generates a
	120	* control frame.
	121	*/
	122	void nr_write_internal(struct sock *sk, int frametype)
	123	{
	124	struct nr_sock *nr = nr_sk(sk);
	125	struct sk_buff *skb;
	126	unsigned char *dptr;
	127	int len, timeout;
	128
	129	len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
	130
	131	switch (frametype & 0x0F) {
	132	case NR_CONNREQ:
	133	len += 17;
	134	break;
	135	case NR_CONNACK:
	136	len += (nr->bpqext) ? 2 : 1;
	137	break;
	138	case NR_DISCREQ:
	139	case NR_DISCACK:
	140	case NR_INFOACK:
	141	break;
	142	default:
	143	printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype);
144	return;
145	}
146
147	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
148	return;
149
150	/*
151	* Space for AX.25 and NET/ROM network header
152	*/
153	skb_reserve(skb, NR_NETWORK_LEN);
154
155	dptr = skb_put(skb, skb_tailroom(skb));
156
157	switch (frametype & 0x0F) {
158	case NR_CONNREQ:
159	timeout = nr->t1 / HZ;
160	*dptr++ = nr->my_index;
161	*dptr++ = nr->my_id;
162	*dptr++ = 0;
163	*dptr++ = 0;
164	*dptr++ = frametype;
165	*dptr++ = nr->window;
166	memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN);
167	dptr[6] &= ~AX25_CBIT;
168	dptr[6] &= ~AX25_EBIT;
169	dptr[6] \|= AX25_SSSID_SPARE;
170	dptr += AX25_ADDR_LEN;
171	memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
172	dptr[6] &= ~AX25_CBIT;
173	dptr[6] &= ~AX25_EBIT;
174	dptr[6] \|= AX25_SSSID_SPARE;
175	dptr += AX25_ADDR_LEN;
176	*dptr++ = timeout % 256;
177	*dptr++ = timeout / 256;
178	break;
179
180	case NR_CONNACK:
181	*dptr++ = nr->your_index;
182	*dptr++ = nr->your_id;
183	*dptr++ = nr->my_index;
184	*dptr++ = nr->my_id;
185	*dptr++ = frametype;
186	*dptr++ = nr->window;
187	if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
188	break;
189
190	case NR_DISCREQ:
191	case NR_DISCACK:
192	*dptr++ = nr->your_index;
193	*dptr++ = nr->your_id;
194	*dptr++ = 0;
195	*dptr++ = 0;
196	*dptr++ = frametype;
197	break;
198
199	case NR_INFOACK:
200	*dptr++ = nr->your_index;
201	*dptr++ = nr->your_id;
202	*dptr++ = 0;
203	*dptr++ = nr->vr;
204	*dptr++ = frametype;
205	break;
206	}
207
208	nr_transmit_buffer(sk, skb);
209	}
210
211	/*
e21ce8c7	212	* This routine is called to send an error reply.
1da177e4	213	*/
e21ce8c7	214	void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags)
1da177e4 LT	215	{
	216	struct sk_buff *skbn;
	217	unsigned char *dptr;
	218	int len;
	219
	220	len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1;
	221
	222	if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL)
	223	return;
	224
	225	skb_reserve(skbn, 0);
	226
	227	dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
	228
d626f62b	229	skb_copy_from_linear_data_offset(skb, 7, dptr, AX25_ADDR_LEN);
1da177e4 LT	230	dptr[6] &= ~AX25_CBIT;
	231	dptr[6] &= ~AX25_EBIT;
	232	dptr[6] \|= AX25_SSSID_SPARE;
	233	dptr += AX25_ADDR_LEN;
	234
d626f62b	235	skb_copy_from_linear_data(skb, dptr, AX25_ADDR_LEN);
1da177e4 LT	236	dptr[6] &= ~AX25_CBIT;
	237	dptr[6] \|= AX25_EBIT;
	238	dptr[6] \|= AX25_SSSID_SPARE;
	239	dptr += AX25_ADDR_LEN;
	240
	241	*dptr++ = sysctl_netrom_network_ttl_initialiser;
	242
	243	if (mine) {
	244	*dptr++ = 0;
	245	*dptr++ = 0;
	246	*dptr++ = skb->data[15];
	247	*dptr++ = skb->data[16];
	248	} else {
	249	*dptr++ = skb->data[15];
	250	*dptr++ = skb->data[16];
	251	*dptr++ = 0;
	252	*dptr++ = 0;
	253	}
	254
e21ce8c7	255	*dptr++ = cmdflags;
1da177e4 LT	256	*dptr++ = 0;
	257
	258	if (!nr_route_frame(skbn, NULL))
	259	kfree_skb(skbn);
	260	}
	261
	262	void nr_disconnect(struct sock *sk, int reason)
	263	{
	264	nr_stop_t1timer(sk);
	265	nr_stop_t2timer(sk);
	266	nr_stop_t4timer(sk);
	267	nr_stop_idletimer(sk);
	268
	269	nr_clear_queues(sk);
	270
	271	nr_sk(sk)->state = NR_STATE_0;
	272
	273	sk->sk_state = TCP_CLOSE;
	274	sk->sk_err = reason;
	275	sk->sk_shutdown \|= SEND_SHUTDOWN;
	276
	277	if (!sock_flag(sk, SOCK_DEAD)) {
	278	sk->sk_state_change(sk);
	279	sock_set_flag(sk, SOCK_DEAD);
	280	}
	281	}