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ipv4: add pernet mib operations
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / net / tcp.h
CommitLineData
1da177e4
LT		 1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Definitions for the TCP module.
7 *
8 * Version: @(#)tcp.h 1.0.5 05/23/93
9 *
02c30a84 10 * Authors: Ross Biro
1da177e4
LT		 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
17 */
18#ifndef _TCP_H
19#define _TCP_H
20
21#define TCP_DEBUG 1
22#define FASTRETRANS_DEBUG 1
23
1da177e4
LT		 24#include <linux/list.h>
25#include <linux/tcp.h>
26#include <linux/slab.h>
27#include <linux/cache.h>
28#include <linux/percpu.h>
fb286bb2 29#include <linux/skbuff.h>
97fc2f08 30#include <linux/dmaengine.h>
cfb6eeb4 31#include <linux/crypto.h>
c6aefafb 32#include <linux/cryptohash.h>
3f421baa
ACM		 33
34#include <net/inet_connection_sock.h>
295ff7ed 35#include <net/inet_timewait_sock.h>
77d8bf9c 36#include <net/inet_hashtables.h>
1da177e4 37#include <net/checksum.h>
2e6599cb 38#include <net/request_sock.h>
1da177e4
LT		 39#include <net/sock.h>
40#include <net/snmp.h>
41#include <net/ip.h>
c752f073 42#include <net/tcp_states.h>
bdf1ee5d 43#include <net/inet_ecn.h>
c752f073 44
1da177e4
LT		 45#include <linux/seq_file.h>
46
6e04e021 47extern struct inet_hashinfo tcp_hashinfo;
1da177e4 48
1da177e4 49extern atomic_t tcp_orphan_count;
1da177e4 50extern void tcp_time_wait(struct sock *sk, int state, int timeo);
1da177e4 51
1da177e4
LT		 52#define MAX_TCP_HEADER (128 + MAX_HEADER)
53
54/*
55 * Never offer a window over 32767 without using window scaling. Some
56 * poor stacks do signed 16bit maths!
57 */
58#define MAX_TCP_WINDOW 32767U
59
60/* Minimal accepted MSS. It is (60+60+8) - (20+20). */
61#define TCP_MIN_MSS 88U
62
63/* Minimal RCV_MSS. */
64#define TCP_MIN_RCVMSS 536U
65
5d424d5a
JH		 66/* The least MTU to use for probing */
67#define TCP_BASE_MSS 512
68
1da177e4
LT		 69/* After receiving this amount of duplicate ACKs fast retransmit starts. */
70#define TCP_FASTRETRANS_THRESH 3
71
72/* Maximal reordering. */
73#define TCP_MAX_REORDERING 127
74
75/* Maximal number of ACKs sent quickly to accelerate slow-start. */
76#define TCP_MAX_QUICKACKS 16U
77
78/* urg_data states */
79#define TCP_URG_VALID 0x0100
80#define TCP_URG_NOTYET 0x0200
81#define TCP_URG_READ 0x0400
82
83#define TCP_RETR1 3 /*
84 * This is how many retries it does before it
85 * tries to figure out if the gateway is
86 * down. Minimal RFC value is 3; it corresponds
87 * to ~3sec-8min depending on RTO.
88 */
89
90#define TCP_RETR2 15 /*
91 * This should take at least
92 * 90 minutes to time out.
93 * RFC1122 says that the limit is 100 sec.
94 * 15 is ~13-30min depending on RTO.
95 */
96
97#define TCP_SYN_RETRIES 5 /* number of times to retry active opening a
caa20d9a 98 * connection: ~180sec is RFC minimum */
1da177e4
LT		 99
100#define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a
caa20d9a 101 * connection: ~180sec is RFC minimum */
1da177e4
LT		 102
103
104#define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned
105 * socket. 7 is ~50sec-16min.
106 */
107
108
109#define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT
110 * state, about 60 seconds */
111#define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN
112 /* BSD style FIN_WAIT2 deadlock breaker.
113 * It used to be 3min, new value is 60sec,
114 * to combine FIN-WAIT-2 timeout with
115 * TIME-WAIT timer.
116 */
117
118#define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */
119#if HZ >= 100
120#define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */
121#define TCP_ATO_MIN ((unsigned)(HZ/25))
122#else
123#define TCP_DELACK_MIN 4U
124#define TCP_ATO_MIN 4U
125#endif
126#define TCP_RTO_MAX ((unsigned)(120*HZ))
127#define TCP_RTO_MIN ((unsigned)(HZ/5))
128#define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */
129
130#define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
131 * for local resources.
132 */
133
134#define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */
135#define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */
136#define TCP_KEEPALIVE_INTVL (75*HZ)
137
138#define MAX_TCP_KEEPIDLE 32767
139#define MAX_TCP_KEEPINTVL 32767
140#define MAX_TCP_KEEPCNT 127
141#define MAX_TCP_SYNCNT 127
142
143#define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */
1da177e4
LT		 144
145#define TCP_PAWS_24DAYS (60 * 60 * 24 * 24)
146#define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated
147 * after this time. It should be equal
148 * (or greater than) TCP_TIMEWAIT_LEN
149 * to provide reliability equal to one
150 * provided by timewait state.
151 */
152#define TCP_PAWS_WINDOW 1 /* Replay window for per-host
153 * timestamps. It must be less than
154 * minimal timewait lifetime.
155 */
1da177e4
LT		 156/*
157 * TCP option
158 */
159
160#define TCPOPT_NOP 1 /* Padding */
161#define TCPOPT_EOL 0 /* End of options */
162#define TCPOPT_MSS 2 /* Segment size negotiating */
163#define TCPOPT_WINDOW 3 /* Window scaling */
164#define TCPOPT_SACK_PERM 4 /* SACK Permitted */
165#define TCPOPT_SACK 5 /* SACK Block */
166#define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
cfb6eeb4 167#define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */
1da177e4
LT		 168
169/*
170 * TCP option lengths
171 */
172
173#define TCPOLEN_MSS 4
174#define TCPOLEN_WINDOW 3
175#define TCPOLEN_SACK_PERM 2
176#define TCPOLEN_TIMESTAMP 10
cfb6eeb4 177#define TCPOLEN_MD5SIG 18
1da177e4
LT		 178
179/* But this is what stacks really send out. */
180#define TCPOLEN_TSTAMP_ALIGNED 12
181#define TCPOLEN_WSCALE_ALIGNED 4
182#define TCPOLEN_SACKPERM_ALIGNED 4
183#define TCPOLEN_SACK_BASE 2
184#define TCPOLEN_SACK_BASE_ALIGNED 4
185#define TCPOLEN_SACK_PERBLOCK 8
cfb6eeb4 186#define TCPOLEN_MD5SIG_ALIGNED 20
1da177e4 187
1da177e4
LT		 188/* Flags in tp->nonagle */
189#define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
190#define TCP_NAGLE_CORK 2 /* Socket is corked */
caa20d9a 191#define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */
1da177e4 192
295ff7ed
ACM		 193extern struct inet_timewait_death_row tcp_death_row;
194
1da177e4 195/* sysctl variables for tcp */
1da177e4
LT		 196extern int sysctl_tcp_timestamps;
197extern int sysctl_tcp_window_scaling;
198extern int sysctl_tcp_sack;
199extern int sysctl_tcp_fin_timeout;
1da177e4
LT		 200extern int sysctl_tcp_keepalive_time;
201extern int sysctl_tcp_keepalive_probes;
202extern int sysctl_tcp_keepalive_intvl;
203extern int sysctl_tcp_syn_retries;
204extern int sysctl_tcp_synack_retries;
205extern int sysctl_tcp_retries1;
206extern int sysctl_tcp_retries2;
207extern int sysctl_tcp_orphan_retries;
208extern int sysctl_tcp_syncookies;
209extern int sysctl_tcp_retrans_collapse;
210extern int sysctl_tcp_stdurg;
211extern int sysctl_tcp_rfc1337;
212extern int sysctl_tcp_abort_on_overflow;
213extern int sysctl_tcp_max_orphans;
1da177e4
LT		 214extern int sysctl_tcp_fack;
215extern int sysctl_tcp_reordering;
216extern int sysctl_tcp_ecn;
217extern int sysctl_tcp_dsack;
218extern int sysctl_tcp_mem[3];
219extern int sysctl_tcp_wmem[3];
220extern int sysctl_tcp_rmem[3];
221extern int sysctl_tcp_app_win;
222extern int sysctl_tcp_adv_win_scale;
223extern int sysctl_tcp_tw_reuse;
224extern int sysctl_tcp_frto;
3cfe3baa 225extern int sysctl_tcp_frto_response;
1da177e4 226extern int sysctl_tcp_low_latency;
95937825 227extern int sysctl_tcp_dma_copybreak;
1da177e4 228extern int sysctl_tcp_nometrics_save;
1da177e4
LT		 229extern int sysctl_tcp_moderate_rcvbuf;
230extern int sysctl_tcp_tso_win_divisor;
9772efb9 231extern int sysctl_tcp_abc;
5d424d5a
JH		 232extern int sysctl_tcp_mtu_probing;
233extern int sysctl_tcp_base_mss;
15d99e02 234extern int sysctl_tcp_workaround_signed_windows;
35089bb2 235extern int sysctl_tcp_slow_start_after_idle;
886236c1 236extern int sysctl_tcp_max_ssthresh;
1da177e4
LT		 237
238extern atomic_t tcp_memory_allocated;
239extern atomic_t tcp_sockets_allocated;
240extern int tcp_memory_pressure;
241
1da177e4
LT		 242/*
243 * The next routines deal with comparing 32 bit unsigned ints
244 * and worry about wraparound (automatic with unsigned arithmetic).
245 */
246
247static inline int before(__u32 seq1, __u32 seq2)
248{
0d630cc0 249 return (__s32)(seq1-seq2) < 0;
1da177e4 250}
9a036b9c 251#define after(seq2, seq1) before(seq1, seq2)
1da177e4
LT		 252
253/* is s2<=s1<=s3 ? */
254static inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
255{
256 return seq3 - seq2 >= seq1 - seq2;
257}
258
e4fd5da3
PE		 259static inline int tcp_too_many_orphans(struct sock *sk, int num)
260{
261 return (num > sysctl_tcp_max_orphans) ||
262 (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
263 atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2]);
264}
1da177e4
LT		 265
266extern struct proto tcp_prot;
267
268DECLARE_SNMP_STAT(struct tcp_mib, tcp_statistics);
81cc8a75 269#define TCP_INC_STATS(net, field) do { (void)net; SNMP_INC_STATS(tcp_statistics, field); } while (0)
63231bdd 270#define TCP_INC_STATS_BH(net, field) do { (void)net; SNMP_INC_STATS_BH(tcp_statistics, field); } while (0)
74688e48 271#define TCP_DEC_STATS(net, field) do { (void)net; SNMP_DEC_STATS(tcp_statistics, field); } while (0)
cf1100a7 272#define TCP_ADD_STATS_USER(net, field, val) do { (void)net; SNMP_ADD_STATS_USER(tcp_statistics, field, val); } while (0)
1da177e4 273
1da177e4
LT		 274extern void tcp_v4_err(struct sk_buff *skb, u32);
275
276extern void tcp_shutdown (struct sock *sk, int how);
277
278extern int tcp_v4_rcv(struct sk_buff *skb);
279
280extern int tcp_v4_remember_stamp(struct sock *sk);
281
8feaf0c0 282extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
1da177e4 283
3516ffb0 284extern int tcp_sendmsg(struct kiocb *iocb, struct socket *sock,
1da177e4
LT		 285 struct msghdr *msg, size_t size);
286extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags);
287
288extern int tcp_ioctl(struct sock *sk,
289 int cmd,
290 unsigned long arg);
291
292extern int tcp_rcv_state_process(struct sock *sk,
293 struct sk_buff *skb,
294 struct tcphdr *th,
295 unsigned len);
296
297extern int tcp_rcv_established(struct sock *sk,
298 struct sk_buff *skb,
299 struct tcphdr *th,
300 unsigned len);
301
302extern void tcp_rcv_space_adjust(struct sock *sk);
303
0e4b4992
CL		 304extern void tcp_cleanup_rbuf(struct sock *sk, int copied);
305
6d6ee43e
ACM		 306extern int tcp_twsk_unique(struct sock *sk,
307 struct sock *sktw, void *twp);
308
cfb6eeb4
YH		 309extern void tcp_twsk_destructor(struct sock *sk);
310
9c55e01c
JA		 311extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos,
312 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
313
463c84b9
ACM		 314static inline void tcp_dec_quickack_mode(struct sock *sk,
315 const unsigned int pkts)
1da177e4 316{
463c84b9 317 struct inet_connection_sock *icsk = inet_csk(sk);
fc6415bc 318
463c84b9
ACM		 319 if (icsk->icsk_ack.quick) {
320 if (pkts >= icsk->icsk_ack.quick) {
321 icsk->icsk_ack.quick = 0;
fc6415bc 322 /* Leaving quickack mode we deflate ATO. */
463c84b9 323 icsk->icsk_ack.ato = TCP_ATO_MIN;
fc6415bc 324 } else
463c84b9 325 icsk->icsk_ack.quick -= pkts;
1da177e4
LT		 326 }
327}
328
463c84b9 329extern void tcp_enter_quickack_mode(struct sock *sk);
1da177e4 330
1da177e4
LT		 331static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
332{
333 rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
334}
335
bdf1ee5d
IJ		 336#define TCP_ECN_OK 1
337#define TCP_ECN_QUEUE_CWR 2
338#define TCP_ECN_DEMAND_CWR 4
339
340static __inline__ void
341TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th)
342{
343 if (sysctl_tcp_ecn && th->ece && th->cwr)
344 inet_rsk(req)->ecn_ok = 1;
345}
346
1da177e4
LT		 347enum tcp_tw_status
348{
349 TCP_TW_SUCCESS = 0,
350 TCP_TW_RST = 1,
351 TCP_TW_ACK = 2,
352 TCP_TW_SYN = 3
353};
354
355
8feaf0c0 356extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw,
1da177e4 357 struct sk_buff *skb,
8feaf0c0 358 const struct tcphdr *th);
1da177e4
LT		 359
360extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb,
60236fdd
ACM		 361 struct request_sock *req,
362 struct request_sock **prev);
1da177e4
LT		 363extern int tcp_child_process(struct sock *parent,
364 struct sock *child,
365 struct sk_buff *skb);
46d0de4e 366extern int tcp_use_frto(struct sock *sk);
1da177e4
LT		 367extern void tcp_enter_frto(struct sock *sk);
368extern void tcp_enter_loss(struct sock *sk, int how);
369extern void tcp_clear_retrans(struct tcp_sock *tp);
370extern void tcp_update_metrics(struct sock *sk);
371
372extern void tcp_close(struct sock *sk,
373 long timeout);
1da177e4
LT		 374extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait);
375
376extern int tcp_getsockopt(struct sock *sk, int level,
377 int optname,
378 char __user *optval,
379 int __user *optlen);
380extern int tcp_setsockopt(struct sock *sk, int level,
381 int optname, char __user *optval,
382 int optlen);
3fdadf7d
DM		 383extern int compat_tcp_getsockopt(struct sock *sk,
384 int level, int optname,
385 char __user *optval, int __user *optlen);
386extern int compat_tcp_setsockopt(struct sock *sk,
387 int level, int optname,
388 char __user *optval, int optlen);
1da177e4
LT		 389extern void tcp_set_keepalive(struct sock *sk, int val);
390extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
391 struct msghdr *msg,
392 size_t len, int nonblock,
393 int flags, int *addr_len);
394
1da177e4
LT		 395extern void tcp_parse_options(struct sk_buff *skb,
396 struct tcp_options_received *opt_rx,
397 int estab);
398
7d5d5525
YH		 399extern u8 *tcp_parse_md5sig_option(struct tcphdr *th);
400
1da177e4
LT		 401/*
402 * TCP v4 functions exported for the inet6 API
403 */
404
8292a17a 405extern void tcp_v4_send_check(struct sock *sk, int len,
1da177e4
LT		 406 struct sk_buff *skb);
407
408extern int tcp_v4_conn_request(struct sock *sk,
409 struct sk_buff *skb);
410
411extern struct sock * tcp_create_openreq_child(struct sock *sk,
60236fdd 412 struct request_sock *req,
1da177e4
LT		 413 struct sk_buff *skb);
414
415extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk,
416 struct sk_buff *skb,
60236fdd 417 struct request_sock *req,
1da177e4
LT		 418 struct dst_entry *dst);
419
420extern int tcp_v4_do_rcv(struct sock *sk,
421 struct sk_buff *skb);
422
423extern int tcp_v4_connect(struct sock *sk,
424 struct sockaddr *uaddr,
425 int addr_len);
426
427extern int tcp_connect(struct sock *sk);
428
429extern struct sk_buff * tcp_make_synack(struct sock *sk,
430 struct dst_entry *dst,
60236fdd 431 struct request_sock *req);
1da177e4
LT		 432
433extern int tcp_disconnect(struct sock *sk, int flags);
434
1da177e4 435
1da177e4 436/* From syncookies.c */
2051f11f 437extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];
1da177e4
LT		 438extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
439 struct ip_options *opt);
440extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
441 __u16 *mss);
442
4dfc2817
FW		 443extern __u32 cookie_init_timestamp(struct request_sock *req);
444extern void cookie_check_timestamp(struct tcp_options_received *tcp_opt);
445
c6aefafb
GG		 446/* From net/ipv6/syncookies.c */
447extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb);
448extern __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb,
449 __u16 *mss);
450
1da177e4
LT		 451/* tcp_output.c */
452
9e412ba7
IJ		 453extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
454 int nonagle);
455extern int tcp_may_send_now(struct sock *sk);
1da177e4
LT		 456extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);
457extern void tcp_xmit_retransmit_queue(struct sock *);
458extern void tcp_simple_retransmit(struct sock *);
459extern int tcp_trim_head(struct sock *, struct sk_buff *, u32);
6475be16 460extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int);
1da177e4
LT		 461
462extern void tcp_send_probe0(struct sock *);
463extern void tcp_send_partial(struct sock *);
464extern int tcp_write_wakeup(struct sock *);
465extern void tcp_send_fin(struct sock *sk);
dd0fc66f 466extern void tcp_send_active_reset(struct sock *sk, gfp_t priority);
1da177e4 467extern int tcp_send_synack(struct sock *);
c1b4a7e6 468extern void tcp_push_one(struct sock *, unsigned int mss_now);
1da177e4
LT		 469extern void tcp_send_ack(struct sock *sk);
470extern void tcp_send_delayed_ack(struct sock *sk);
471
a762a980
DM		 472/* tcp_input.c */
473extern void tcp_cwnd_application_limited(struct sock *sk);
474
1da177e4
LT		 475/* tcp_timer.c */
476extern void tcp_init_xmit_timers(struct sock *);
463c84b9
ACM		 477static inline void tcp_clear_xmit_timers(struct sock *sk)
478{
479 inet_csk_clear_xmit_timers(sk);
480}
1da177e4 481
1da177e4
LT		 482extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu);
483extern unsigned int tcp_current_mss(struct sock *sk, int large);
484
17b085ea 485/* tcp.c */
1da177e4
LT		 486extern void tcp_get_info(struct sock *, struct tcp_info *);
487
488/* Read 'sendfile()'-style from a TCP socket */
489typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
490 unsigned int, size_t);
491extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
492 sk_read_actor_t recv_actor);
493
40efc6fa 494extern void tcp_initialize_rcv_mss(struct sock *sk);
1da177e4 495
5d424d5a
JH		 496extern int tcp_mtu_to_mss(struct sock *sk, int pmtu);
497extern int tcp_mss_to_mtu(struct sock *sk, int mss);
498extern void tcp_mtup_init(struct sock *sk);
499
40efc6fa 500static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd)
1da177e4
LT		 501{
502 tp->pred_flags = htonl((tp->tcp_header_len << 26) |
503 ntohl(TCP_FLAG_ACK) |
504 snd_wnd);
505}
506
40efc6fa 507static inline void tcp_fast_path_on(struct tcp_sock *tp)
1da177e4
LT		 508{
509 __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale);
510}
511
9e412ba7 512static inline void tcp_fast_path_check(struct sock *sk)
1da177e4 513{
9e412ba7
IJ		 514 struct tcp_sock *tp = tcp_sk(sk);
515
b03efcfb 516 if (skb_queue_empty(&tp->out_of_order_queue) &&
1da177e4
LT		 517 tp->rcv_wnd &&
518 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
519 !tp->urg_data)
520 tcp_fast_path_on(tp);
521}
522
523/* Compute the actual receive window we are currently advertising.
524 * Rcv_nxt can be after the window if our peer push more data
525 * than the offered window.
526 */
40efc6fa 527static inline u32 tcp_receive_window(const struct tcp_sock *tp)
1da177e4
LT		 528{
529 s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt;
530
531 if (win < 0)
532 win = 0;
533 return (u32) win;
534}
535
536/* Choose a new window, without checks for shrinking, and without
537 * scaling applied to the result. The caller does these things
538 * if necessary. This is a "raw" window selection.
539 */
540extern u32 __tcp_select_window(struct sock *sk);
541
542/* TCP timestamps are only 32-bits, this causes a slight
543 * complication on 64-bit systems since we store a snapshot
31f34269
SH		 544 * of jiffies in the buffer control blocks below. We decided
545 * to use only the low 32-bits of jiffies and hide the ugly
1da177e4
LT		 546 * casts with the following macro.
547 */
548#define tcp_time_stamp ((__u32)(jiffies))
549
caa20d9a 550/* This is what the send packet queuing engine uses to pass
1da177e4
LT		 551 * TCP per-packet control information to the transmission
552 * code. We also store the host-order sequence numbers in
553 * here too. This is 36 bytes on 32-bit architectures,
554 * 40 bytes on 64-bit machines, if this grows please adjust
555 * skbuff.h:skbuff->cb[xxx] size appropriately.
556 */
557struct tcp_skb_cb {
558 union {
559 struct inet_skb_parm h4;
560#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
561 struct inet6_skb_parm h6;
562#endif
563 } header; /* For incoming frames */
564 __u32 seq; /* Starting sequence number */
565 __u32 end_seq; /* SEQ + FIN + SYN + datalen */
566 __u32 when; /* used to compute rtt's */
567 __u8 flags; /* TCP header flags. */
568
569 /* NOTE: These must match up to the flags byte in a
570 * real TCP header.
571 */
572#define TCPCB_FLAG_FIN 0x01
573#define TCPCB_FLAG_SYN 0x02
574#define TCPCB_FLAG_RST 0x04
575#define TCPCB_FLAG_PSH 0x08
576#define TCPCB_FLAG_ACK 0x10
577#define TCPCB_FLAG_URG 0x20
578#define TCPCB_FLAG_ECE 0x40
579#define TCPCB_FLAG_CWR 0x80
580
581 __u8 sacked; /* State flags for SACK/FACK. */
582#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
583#define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
584#define TCPCB_LOST 0x04 /* SKB is lost */
585#define TCPCB_TAGBITS 0x07 /* All tag bits */
586
587#define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */
588#define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
589
1da177e4
LT		 590 __u16 urg_ptr; /* Valid w/URG flags is set. */
591 __u32 ack_seq; /* Sequence number ACK'd */
592};
593
594#define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
595
1da177e4
LT		 596/* Due to TSO, an SKB can be composed of multiple actual
597 * packets. To keep these tracked properly, we use this.
598 */
599static inline int tcp_skb_pcount(const struct sk_buff *skb)
600{
7967168c 601 return skb_shinfo(skb)->gso_segs;
1da177e4
LT		 602}
603
604/* This is valid iff tcp_skb_pcount() > 1. */
605static inline int tcp_skb_mss(const struct sk_buff *skb)
606{
7967168c 607 return skb_shinfo(skb)->gso_size;
1da177e4
LT		 608}
609
af610b4c 610static inline void tcp_dec_pcount_approx_int(__u32 *count, const int decr)
1da177e4
LT		 611{
612 if (*count) {
af610b4c 613 *count -= decr;
1da177e4
LT		 614 if ((int)*count < 0)
615 *count = 0;
616 }
617}
618
af610b4c
IJ		 619static inline void tcp_dec_pcount_approx(__u32 *count,
620 const struct sk_buff *skb)
621{
622 tcp_dec_pcount_approx_int(count, tcp_skb_pcount(skb));
623}
624
317a76f9
SH		 625/* Events passed to congestion control interface */
626enum tcp_ca_event {
627 CA_EVENT_TX_START, /* first transmit when no packets in flight */
628 CA_EVENT_CWND_RESTART, /* congestion window restart */
629 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
630 CA_EVENT_FRTO, /* fast recovery timeout */
631 CA_EVENT_LOSS, /* loss timeout */
632 CA_EVENT_FAST_ACK, /* in sequence ack */
633 CA_EVENT_SLOW_ACK, /* other ack */
634};
635
636/*
637 * Interface for adding new TCP congestion control handlers
638 */
639#define TCP_CA_NAME_MAX 16
3ff825b2
SH		 640#define TCP_CA_MAX 128
641#define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX)
642
164891aa
SH		 643#define TCP_CONG_NON_RESTRICTED 0x1
644#define TCP_CONG_RTT_STAMP 0x2
645
317a76f9
SH		 646struct tcp_congestion_ops {
647 struct list_head list;
164891aa 648 unsigned long flags;
317a76f9
SH		 649
650 /* initialize private data (optional) */
6687e988 651 void (*init)(struct sock *sk);
317a76f9 652 /* cleanup private data (optional) */
6687e988 653 void (*release)(struct sock *sk);
317a76f9
SH		 654
655 /* return slow start threshold (required) */
6687e988 656 u32 (*ssthresh)(struct sock *sk);
317a76f9 657 /* lower bound for congestion window (optional) */
72dc5b92 658 u32 (*min_cwnd)(const struct sock *sk);
317a76f9 659 /* do new cwnd calculation (required) */
c3a05c60 660 void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight);
317a76f9 661 /* call before changing ca_state (optional) */
6687e988 662 void (*set_state)(struct sock *sk, u8 new_state);
317a76f9 663 /* call when cwnd event occurs (optional) */
6687e988 664 void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
317a76f9 665 /* new value of cwnd after loss (optional) */
6687e988 666 u32 (*undo_cwnd)(struct sock *sk);
317a76f9 667 /* hook for packet ack accounting (optional) */
30cfd0ba 668 void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us);
73c1f4a0 669 /* get info for inet_diag (optional) */
6687e988 670 void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb);
317a76f9
SH		 671
672 char name[TCP_CA_NAME_MAX];
673 struct module *owner;
674};
675
676extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
677extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
678
6687e988
ACM		 679extern void tcp_init_congestion_control(struct sock *sk);
680extern void tcp_cleanup_congestion_control(struct sock *sk);
317a76f9
SH		 681extern int tcp_set_default_congestion_control(const char *name);
682extern void tcp_get_default_congestion_control(char *name);
3ff825b2 683extern void tcp_get_available_congestion_control(char *buf, size_t len);
ce7bc3bf
SH		 684extern void tcp_get_allowed_congestion_control(char *buf, size_t len);
685extern int tcp_set_allowed_congestion_control(char *allowed);
6687e988 686extern int tcp_set_congestion_control(struct sock *sk, const char *name);
40efc6fa 687extern void tcp_slow_start(struct tcp_sock *tp);
317a76f9 688
5f8ef48d 689extern struct tcp_congestion_ops tcp_init_congestion_ops;
6687e988 690extern u32 tcp_reno_ssthresh(struct sock *sk);
c3a05c60 691extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight);
72dc5b92 692extern u32 tcp_reno_min_cwnd(const struct sock *sk);
a8acfbac 693extern struct tcp_congestion_ops tcp_reno;
317a76f9 694
6687e988 695static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state)
317a76f9 696{
6687e988
ACM		 697 struct inet_connection_sock *icsk = inet_csk(sk);
698
699 if (icsk->icsk_ca_ops->set_state)
700 icsk->icsk_ca_ops->set_state(sk, ca_state);
701 icsk->icsk_ca_state = ca_state;
317a76f9
SH		 702}
703
6687e988 704static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event)
317a76f9 705{
6687e988
ACM		 706 const struct inet_connection_sock *icsk = inet_csk(sk);
707
708 if (icsk->icsk_ca_ops->cwnd_event)
709 icsk->icsk_ca_ops->cwnd_event(sk, event);
317a76f9
SH		 710}
711
e60402d0
IJ		 712/* These functions determine how the current flow behaves in respect of SACK
713 * handling. SACK is negotiated with the peer, and therefore it can vary
714 * between different flows.
715 *
716 * tcp_is_sack - SACK enabled
717 * tcp_is_reno - No SACK
718 * tcp_is_fack - FACK enabled, implies SACK enabled
719 */
720static inline int tcp_is_sack(const struct tcp_sock *tp)
721{
722 return tp->rx_opt.sack_ok;
723}
724
725static inline int tcp_is_reno(const struct tcp_sock *tp)
726{
727 return !tcp_is_sack(tp);
728}
729
730static inline int tcp_is_fack(const struct tcp_sock *tp)
731{
732 return tp->rx_opt.sack_ok & 2;
733}
734
735static inline void tcp_enable_fack(struct tcp_sock *tp)
736{
737 tp->rx_opt.sack_ok |= 2;
738}
739
83ae4088
IJ		 740static inline unsigned int tcp_left_out(const struct tcp_sock *tp)
741{
742 return tp->sacked_out + tp->lost_out;
743}
744
1da177e4
LT		 745/* This determines how many packets are "in the network" to the best
746 * of our knowledge. In many cases it is conservative, but where
747 * detailed information is available from the receiver (via SACK
748 * blocks etc.) we can make more aggressive calculations.
749 *
750 * Use this for decisions involving congestion control, use just
751 * tp->packets_out to determine if the send queue is empty or not.
752 *
753 * Read this equation as:
754 *
755 * "Packets sent once on transmission queue" MINUS
756 * "Packets left network, but not honestly ACKed yet" PLUS
757 * "Packets fast retransmitted"
758 */
40efc6fa 759static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
1da177e4 760{
83ae4088 761 return tp->packets_out - tcp_left_out(tp) + tp->retrans_out;
1da177e4
LT		 762}
763
882bebaa
IJ		 764extern int tcp_limit_reno_sacked(struct tcp_sock *tp);
765
1da177e4
LT		 766/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
767 * The exception is rate halving phase, when cwnd is decreasing towards
768 * ssthresh.
769 */
6687e988 770static inline __u32 tcp_current_ssthresh(const struct sock *sk)
1da177e4 771{
6687e988
ACM		 772 const struct tcp_sock *tp = tcp_sk(sk);
773 if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery))
1da177e4
LT		 774 return tp->snd_ssthresh;
775 else
776 return max(tp->snd_ssthresh,
777 ((tp->snd_cwnd >> 1) +
778 (tp->snd_cwnd >> 2)));
779}
780
b9c4595b
IJ		 781/* Use define here intentionally to get WARN_ON location shown at the caller */
782#define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out)
1da177e4 783
3cfe3baa 784extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh);
1da177e4
LT		 785extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst);
786
787/* Slow start with delack produces 3 packets of burst, so that
dd9e0dda
JH		 788 * it is safe "de facto". This will be the default - same as
789 * the default reordering threshold - but if reordering increases,
790 * we must be able to allow cwnd to burst at least this much in order
791 * to not pull it back when holes are filled.
1da177e4
LT		 792 */
793static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
794{
dd9e0dda 795 return tp->reordering;
1da177e4
LT		 796}
797
90840def
IJ		 798/* Returns end sequence number of the receiver's advertised window */
799static inline u32 tcp_wnd_end(const struct tcp_sock *tp)
800{
801 return tp->snd_una + tp->snd_wnd;
802}
cea14e0e 803extern int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight);
f4805ede 804
c1bd24b7 805static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss,
40efc6fa 806 const struct sk_buff *skb)
1da177e4
LT		 807{
808 if (skb->len < mss)
809 tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
810}
811
9e412ba7 812static inline void tcp_check_probe_timer(struct sock *sk)
1da177e4 813{
9e412ba7 814 struct tcp_sock *tp = tcp_sk(sk);
463c84b9 815 const struct inet_connection_sock *icsk = inet_csk(sk);
9e412ba7 816
463c84b9 817 if (!tp->packets_out && !icsk->icsk_pending)
3f421baa
ACM		 818 inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
819 icsk->icsk_rto, TCP_RTO_MAX);
1da177e4
LT		 820}
821
9e412ba7 822static inline void tcp_push_pending_frames(struct sock *sk)
1da177e4 823{
9e412ba7
IJ		 824 struct tcp_sock *tp = tcp_sk(sk);
825
826 __tcp_push_pending_frames(sk, tcp_current_mss(sk, 1), tp->nonagle);
1da177e4
LT		 827}
828
40efc6fa 829static inline void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq)
1da177e4
LT		 830{
831 tp->snd_wl1 = seq;
832}
833
40efc6fa 834static inline void tcp_update_wl(struct tcp_sock *tp, u32 ack, u32 seq)
1da177e4
LT		 835{
836 tp->snd_wl1 = seq;
837}
838
1da177e4
LT		 839/*
840 * Calculate(/check) TCP checksum
841 */
ba7808ea
FD		 842static inline __sum16 tcp_v4_check(int len, __be32 saddr,
843 __be32 daddr, __wsum base)
1da177e4
LT		 844{
845 return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base);
846}
847
b51655b9 848static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb)
1da177e4 849{
fb286bb2 850 return __skb_checksum_complete(skb);
1da177e4
LT		 851}
852
40efc6fa 853static inline int tcp_checksum_complete(struct sk_buff *skb)
1da177e4 854{
60476372 855 return !skb_csum_unnecessary(skb) &&
1da177e4
LT		 856 __tcp_checksum_complete(skb);
857}
858
859/* Prequeue for VJ style copy to user, combined with checksumming. */
860
40efc6fa 861static inline void tcp_prequeue_init(struct tcp_sock *tp)
1da177e4
LT		 862{
863 tp->ucopy.task = NULL;
864 tp->ucopy.len = 0;
865 tp->ucopy.memory = 0;
866 skb_queue_head_init(&tp->ucopy.prequeue);
97fc2f08
CL		 867#ifdef CONFIG_NET_DMA
868 tp->ucopy.dma_chan = NULL;
869 tp->ucopy.wakeup = 0;
870 tp->ucopy.pinned_list = NULL;
871 tp->ucopy.dma_cookie = 0;
872#endif
1da177e4
LT		 873}
874
875/* Packet is added to VJ-style prequeue for processing in process
876 * context, if a reader task is waiting. Apparently, this exciting
877 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
878 * failed somewhere. Latency? Burstiness? Well, at least now we will
879 * see, why it failed. 8)8) --ANK
880 *
881 * NOTE: is this not too big to inline?
882 */
40efc6fa 883static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb)
1da177e4
LT		 884{
885 struct tcp_sock *tp = tcp_sk(sk);
886
887 if (!sysctl_tcp_low_latency && tp->ucopy.task) {
888 __skb_queue_tail(&tp->ucopy.prequeue, skb);
889 tp->ucopy.memory += skb->truesize;
890 if (tp->ucopy.memory > sk->sk_rcvbuf) {
891 struct sk_buff *skb1;
892
893 BUG_ON(sock_owned_by_user(sk));
894
895 while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) {
896 sk->sk_backlog_rcv(sk, skb1);
de0744af 897 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPPREQUEUEDROPPED);
1da177e4
LT		 898 }
899
900 tp->ucopy.memory = 0;
901 } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
902 wake_up_interruptible(sk->sk_sleep);
463c84b9
ACM		 903 if (!inet_csk_ack_scheduled(sk))
904 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
3f421baa
ACM		 905 (3 * TCP_RTO_MIN) / 4,
906 TCP_RTO_MAX);
1da177e4
LT		 907 }
908 return 1;
909 }
910 return 0;
911}
912
913
914#undef STATE_TRACE
915
916#ifdef STATE_TRACE
917static const char *statename[]={
918 "Unused","Established","Syn Sent","Syn Recv",
919 "Fin Wait 1","Fin Wait 2","Time Wait", "Close",
920 "Close Wait","Last ACK","Listen","Closing"
921};
922#endif
490d5046 923extern void tcp_set_state(struct sock *sk, int state);
1da177e4 924
4ac02bab 925extern void tcp_done(struct sock *sk);
1da177e4 926
40efc6fa 927static inline void tcp_sack_reset(struct tcp_options_received *rx_opt)
1da177e4
LT		 928{
929 rx_opt->dsack = 0;
930 rx_opt->eff_sacks = 0;
931 rx_opt->num_sacks = 0;
932}
933
1da177e4
LT		 934/* Determine a window scaling and initial window to offer. */
935extern void tcp_select_initial_window(int __space, __u32 mss,
936 __u32 *rcv_wnd, __u32 *window_clamp,
937 int wscale_ok, __u8 *rcv_wscale);
938
939static inline int tcp_win_from_space(int space)
940{
941 return sysctl_tcp_adv_win_scale<=0 ?
942 (space>>(-sysctl_tcp_adv_win_scale)) :
943 space - (space>>sysctl_tcp_adv_win_scale);
944}
945
946/* Note: caller must be prepared to deal with negative returns */
947static inline int tcp_space(const struct sock *sk)
948{
949 return tcp_win_from_space(sk->sk_rcvbuf -
950 atomic_read(&sk->sk_rmem_alloc));
951}
952
953static inline int tcp_full_space(const struct sock *sk)
954{
955 return tcp_win_from_space(sk->sk_rcvbuf);
956}
957
40efc6fa
SH		 958static inline void tcp_openreq_init(struct request_sock *req,
959 struct tcp_options_received *rx_opt,
960 struct sk_buff *skb)
1da177e4 961{
2e6599cb
ACM		 962 struct inet_request_sock *ireq = inet_rsk(req);
963
1da177e4 964 req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */
4dfc2817 965 req->cookie_ts = 0;
2e6599cb 966 tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
1da177e4
LT		 967 req->mss = rx_opt->mss_clamp;
968 req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
2e6599cb
ACM		 969 ireq->tstamp_ok = rx_opt->tstamp_ok;
970 ireq->sack_ok = rx_opt->sack_ok;
971 ireq->snd_wscale = rx_opt->snd_wscale;
972 ireq->wscale_ok = rx_opt->wscale_ok;
973 ireq->acked = 0;
974 ireq->ecn_ok = 0;
aa8223c7 975 ireq->rmt_port = tcp_hdr(skb)->source;
1da177e4
LT		 976}
977
5c52ba17 978extern void tcp_enter_memory_pressure(struct sock *sk);
1da177e4 979
1da177e4
LT		 980static inline int keepalive_intvl_when(const struct tcp_sock *tp)
981{
982 return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl;
983}
984
985static inline int keepalive_time_when(const struct tcp_sock *tp)
986{
987 return tp->keepalive_time ? : sysctl_tcp_keepalive_time;
988}
989
463c84b9 990static inline int tcp_fin_time(const struct sock *sk)
1da177e4 991{
463c84b9
ACM		 992 int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout;
993 const int rto = inet_csk(sk)->icsk_rto;
1da177e4 994
463c84b9
ACM		 995 if (fin_timeout < (rto << 2) - (rto >> 1))
996 fin_timeout = (rto << 2) - (rto >> 1);
1da177e4
LT		 997
998 return fin_timeout;
999}
1000
1001static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, int rst)
1002{
1003 if ((s32)(rx_opt->rcv_tsval - rx_opt->ts_recent) >= 0)
1004 return 0;
9d729f72 1005 if (get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)
1da177e4
LT		 1006 return 0;
1007
1008 /* RST segments are not recommended to carry timestamp,
1009 and, if they do, it is recommended to ignore PAWS because
1010 "their cleanup function should take precedence over timestamps."
1011 Certainly, it is mistake. It is necessary to understand the reasons
1012 of this constraint to relax it: if peer reboots, clock may go
1013 out-of-sync and half-open connections will not be reset.
1014 Actually, the problem would be not existing if all
1015 the implementations followed draft about maintaining clock
1016 via reboots. Linux-2.2 DOES NOT!
1017
1018 However, we can relax time bounds for RST segments to MSL.
1019 */
9d729f72 1020 if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
1da177e4
LT		 1021 return 0;
1022 return 1;
1023}
1024
1da177e4
LT		 1025#define TCP_CHECK_TIMER(sk) do { } while (0)
1026
a9c19329 1027static inline void tcp_mib_init(struct net *net)
1da177e4
LT		 1028{
1029 /* See RFC 2012 */
cf1100a7
PE		 1030 TCP_ADD_STATS_USER(net, TCP_MIB_RTOALGORITHM, 1);
1031 TCP_ADD_STATS_USER(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ);
1032 TCP_ADD_STATS_USER(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ);
1033 TCP_ADD_STATS_USER(net, TCP_MIB_MAXCONN, -1);
1da177e4
LT		 1034}
1035
5af4ec23 1036/* from STCP */
0800f170
DM		 1037static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp)
1038{
6a438bbe
SH		 1039 tp->lost_skb_hint = NULL;
1040 tp->scoreboard_skb_hint = NULL;
1041 tp->retransmit_skb_hint = NULL;
1042 tp->forward_skb_hint = NULL;
b7689205
IJ		 1043}
1044
0800f170
DM		 1045static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp)
1046{
b7689205 1047 tcp_clear_retrans_hints_partial(tp);
6a438bbe
SH		 1048}
1049
cfb6eeb4
YH		 1050/* MD5 Signature */
1051struct crypto_hash;
1052
1053/* - key database */
1054struct tcp_md5sig_key {
1055 u8 *key;
1056 u8 keylen;
1057};
1058
1059struct tcp4_md5sig_key {
f8ab18d2 1060 struct tcp_md5sig_key base;
cfb6eeb4
YH		 1061 __be32 addr;
1062};
1063
1064struct tcp6_md5sig_key {
f8ab18d2 1065 struct tcp_md5sig_key base;
cfb6eeb4
YH		 1066#if 0
1067 u32 scope_id; /* XXX */
1068#endif
1069 struct in6_addr addr;
1070};
1071
1072/* - sock block */
1073struct tcp_md5sig_info {
1074 struct tcp4_md5sig_key *keys4;
1075#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1076 struct tcp6_md5sig_key *keys6;
1077 u32 entries6;
1078 u32 alloced6;
1079#endif
1080 u32 entries4;
1081 u32 alloced4;
1082};
1083
1084/* - pseudo header */
1085struct tcp4_pseudohdr {
1086 __be32 saddr;
1087 __be32 daddr;
1088 __u8 pad;
1089 __u8 protocol;
1090 __be16 len;
1091};
1092
1093struct tcp6_pseudohdr {
1094 struct in6_addr saddr;
1095 struct in6_addr daddr;
1096 __be32 len;
1097 __be32 protocol; /* including padding */
1098};
1099
1100union tcp_md5sum_block {
1101 struct tcp4_pseudohdr ip4;
1102#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1103 struct tcp6_pseudohdr ip6;
1104#endif
1105};
1106
1107/* - pool: digest algorithm, hash description and scratch buffer */
1108struct tcp_md5sig_pool {
1109 struct hash_desc md5_desc;
1110 union tcp_md5sum_block md5_blk;
1111};
1112
1113#define TCP_MD5SIG_MAXKEYS (~(u32)0) /* really?! */
1114
1115/* - functions */
8d26d76d
YH		 1116extern int tcp_calc_md5_hash(char *md5_hash,
1117 struct tcp_md5sig_key *key,
1118 int bplen,
1119 struct tcphdr *th,
1120 unsigned int tcplen,
1121 struct tcp_md5sig_pool *hp);
1122
cfb6eeb4
YH		 1123extern int tcp_v4_calc_md5_hash(char *md5_hash,
1124 struct tcp_md5sig_key *key,
1125 struct sock *sk,
1126 struct dst_entry *dst,
1127 struct request_sock *req,
1128 struct tcphdr *th,
9cb5734e 1129 unsigned int tcplen);
cfb6eeb4
YH		 1130extern struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
1131 struct sock *addr_sk);
1132
1133extern int tcp_v4_md5_do_add(struct sock *sk,
1134 __be32 addr,
1135 u8 *newkey,
1136 u8 newkeylen);
1137
1138extern int tcp_v4_md5_do_del(struct sock *sk,
8e5200f5 1139 __be32 addr);
cfb6eeb4 1140
9501f972
YH		 1141#ifdef CONFIG_TCP_MD5SIG
1142#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_keylen ? \
1143 &(struct tcp_md5sig_key) { \
1144 .key = (twsk)->tw_md5_key, \
1145 .keylen = (twsk)->tw_md5_keylen, \
1146 } : NULL)
1147#else
1148#define tcp_twsk_md5_key(twsk) NULL
1149#endif
1150
cfb6eeb4
YH		 1151extern struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void);
1152extern void tcp_free_md5sig_pool(void);
1153
1154extern struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu);
1155extern void __tcp_put_md5sig_pool(void);
1156
1157static inline
1158struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
1159{
1160 int cpu = get_cpu();
1161 struct tcp_md5sig_pool *ret = __tcp_get_md5sig_pool(cpu);
1162 if (!ret)
1163 put_cpu();
1164 return ret;
1165}
1166
1167static inline void tcp_put_md5sig_pool(void)
1168{
1169 __tcp_put_md5sig_pool();
1170 put_cpu();
1171}
1172
fe067e8a
DM		 1173/* write queue abstraction */
1174static inline void tcp_write_queue_purge(struct sock *sk)
1175{
1176 struct sk_buff *skb;
1177
1178 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
3ab224be
HA		 1179 sk_wmem_free_skb(sk, skb);
1180 sk_mem_reclaim(sk);
fe067e8a
DM		 1181}
1182
1183static inline struct sk_buff *tcp_write_queue_head(struct sock *sk)
1184{
1185 struct sk_buff *skb = sk->sk_write_queue.next;
1186 if (skb == (struct sk_buff *) &sk->sk_write_queue)
1187 return NULL;
1188 return skb;
1189}
1190
1191static inline struct sk_buff *tcp_write_queue_tail(struct sock *sk)
1192{
1193 struct sk_buff *skb = sk->sk_write_queue.prev;
1194 if (skb == (struct sk_buff *) &sk->sk_write_queue)
1195 return NULL;
1196 return skb;
1197}
1198
1199static inline struct sk_buff *tcp_write_queue_next(struct sock *sk, struct sk_buff *skb)
1200{
1201 return skb->next;
1202}
1203
1204#define tcp_for_write_queue(skb, sk) \
1205 for (skb = (sk)->sk_write_queue.next; \
1206 (skb != (struct sk_buff *)&(sk)->sk_write_queue); \
1207 skb = skb->next)
1208
1209#define tcp_for_write_queue_from(skb, sk) \
1210 for (; (skb != (struct sk_buff *)&(sk)->sk_write_queue);\
1211 skb = skb->next)
1212
234b6860
IJ		 1213#define tcp_for_write_queue_from_safe(skb, tmp, sk) \
1214 for (tmp = skb->next; \
1215 (skb != (struct sk_buff *)&(sk)->sk_write_queue); \
1216 skb = tmp, tmp = skb->next)
1217
fe067e8a
DM		 1218static inline struct sk_buff *tcp_send_head(struct sock *sk)
1219{
1220 return sk->sk_send_head;
1221}
1222
1223static inline void tcp_advance_send_head(struct sock *sk, struct sk_buff *skb)
1224{
1225 sk->sk_send_head = skb->next;
1226 if (sk->sk_send_head == (struct sk_buff *)&sk->sk_write_queue)
1227 sk->sk_send_head = NULL;
1228}
1229
1230static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked)
1231{
1232 if (sk->sk_send_head == skb_unlinked)
1233 sk->sk_send_head = NULL;
1234}
1235
1236static inline void tcp_init_send_head(struct sock *sk)
1237{
1238 sk->sk_send_head = NULL;
1239}
1240
1241static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
1242{
1243 __skb_queue_tail(&sk->sk_write_queue, skb);
1244}
1245
1246static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
1247{
1248 __tcp_add_write_queue_tail(sk, skb);
1249
1250 /* Queue it, remembering where we must start sending. */
6859d494 1251 if (sk->sk_send_head == NULL) {
fe067e8a 1252 sk->sk_send_head = skb;
6859d494
IJ		 1253
1254 if (tcp_sk(sk)->highest_sack == NULL)
1255 tcp_sk(sk)->highest_sack = skb;
1256 }
fe067e8a
DM		 1257}
1258
1259static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb)
1260{
1261 __skb_queue_head(&sk->sk_write_queue, skb);
1262}
1263
1264/* Insert buff after skb on the write queue of sk. */
1265static inline void tcp_insert_write_queue_after(struct sk_buff *skb,
1266 struct sk_buff *buff,
1267 struct sock *sk)
1268{
7de6c033 1269 __skb_queue_after(&sk->sk_write_queue, skb, buff);
fe067e8a
DM		 1270}
1271
1272/* Insert skb between prev and next on the write queue of sk. */
1273static inline void tcp_insert_write_queue_before(struct sk_buff *new,
1274 struct sk_buff *skb,
1275 struct sock *sk)
1276{
1277 __skb_insert(new, skb->prev, skb, &sk->sk_write_queue);