blob: 438014d57610d3c22355746e7f73e73ec73a3785 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 *
Jesper Juhl02c30a82005-05-05 16:16:16 -070010 * Authors: Ross Biro
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/list.h>
25#include <linux/tcp.h>
26#include <linux/slab.h>
27#include <linux/cache.h>
28#include <linux/percpu.h>
Herbert Xufb286bb2005-11-10 13:01:24 -080029#include <linux/skbuff.h>
Chris Leech97fc2f02006-05-23 17:55:33 -070030#include <linux/dmaengine.h>
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080031#include <linux/crypto.h>
Glenn Griffinc6aefaf2008-02-07 21:49:26 -080032#include <linux/cryptohash.h>
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -070033
34#include <net/inet_connection_sock.h>
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -070035#include <net/inet_timewait_sock.h>
Arnaldo Carvalho de Melo77d8bf92005-08-09 20:00:51 -070036#include <net/inet_hashtables.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <net/checksum.h>
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -070038#include <net/request_sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include <net/sock.h>
40#include <net/snmp.h>
41#include <net/ip.h>
Arnaldo Carvalho de Meloc752f072005-08-09 20:08:28 -070042#include <net/tcp_states.h>
Ilpo Järvinenbdf1ee52007-05-27 02:04:16 -070043#include <net/inet_ecn.h>
Arnaldo Carvalho de Meloc752f072005-08-09 20:08:28 -070044
Linus Torvalds1da177e2005-04-16 15:20:36 -070045#include <linux/seq_file.h>
46
Arnaldo Carvalho de Melo6e04e022005-08-09 20:07:35 -070047extern struct inet_hashinfo tcp_hashinfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
Linus Torvalds1da177e2005-04-16 15:20:36 -070049extern atomic_t tcp_orphan_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -070050extern void tcp_time_wait(struct sock *sk, int state, int timeo);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Linus Torvalds1da177e2005-04-16 15:20:36 -070052#define MAX_TCP_HEADER (128 + MAX_HEADER)
Adam Langley33ad7982008-07-19 00:04:31 -070053#define MAX_TCP_OPTION_SPACE 40
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55/*
56 * Never offer a window over 32767 without using window scaling. Some
57 * poor stacks do signed 16bit maths!
58 */
59#define MAX_TCP_WINDOW 32767U
60
61/* Minimal accepted MSS. It is (60+60+8) - (20+20). */
62#define TCP_MIN_MSS 88U
63
64/* Minimal RCV_MSS. */
65#define TCP_MIN_RCVMSS 536U
66
John Heffner5d424d52006-03-20 17:53:41 -080067/* The least MTU to use for probing */
68#define TCP_BASE_MSS 512
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070/* After receiving this amount of duplicate ACKs fast retransmit starts. */
71#define TCP_FASTRETRANS_THRESH 3
72
73/* Maximal reordering. */
74#define TCP_MAX_REORDERING 127
75
76/* Maximal number of ACKs sent quickly to accelerate slow-start. */
77#define TCP_MAX_QUICKACKS 16U
78
79/* urg_data states */
80#define TCP_URG_VALID 0x0100
81#define TCP_URG_NOTYET 0x0200
82#define TCP_URG_READ 0x0400
83
84#define TCP_RETR1 3 /*
85 * This is how many retries it does before it
86 * tries to figure out if the gateway is
87 * down. Minimal RFC value is 3; it corresponds
88 * to ~3sec-8min depending on RTO.
89 */
90
91#define TCP_RETR2 15 /*
92 * This should take at least
93 * 90 minutes to time out.
94 * RFC1122 says that the limit is 100 sec.
95 * 15 is ~13-30min depending on RTO.
96 */
97
98#define TCP_SYN_RETRIES 5 /* number of times to retry active opening a
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -080099 * connection: ~180sec is RFC minimum */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101#define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -0800102 * connection: ~180sec is RFC minimum */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
104
105#define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned
106 * socket. 7 is ~50sec-16min.
107 */
108
109
110#define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT
111 * state, about 60 seconds */
112#define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN
113 /* BSD style FIN_WAIT2 deadlock breaker.
114 * It used to be 3min, new value is 60sec,
115 * to combine FIN-WAIT-2 timeout with
116 * TIME-WAIT timer.
117 */
118
119#define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */
120#if HZ >= 100
121#define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */
122#define TCP_ATO_MIN ((unsigned)(HZ/25))
123#else
124#define TCP_DELACK_MIN 4U
125#define TCP_ATO_MIN 4U
126#endif
127#define TCP_RTO_MAX ((unsigned)(120*HZ))
128#define TCP_RTO_MIN ((unsigned)(HZ/5))
129#define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */
130
131#define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
132 * for local resources.
133 */
134
135#define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */
136#define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */
137#define TCP_KEEPALIVE_INTVL (75*HZ)
138
139#define MAX_TCP_KEEPIDLE 32767
140#define MAX_TCP_KEEPINTVL 32767
141#define MAX_TCP_KEEPCNT 127
142#define MAX_TCP_SYNCNT 127
143
144#define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
146#define TCP_PAWS_24DAYS (60 * 60 * 24 * 24)
147#define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated
148 * after this time. It should be equal
149 * (or greater than) TCP_TIMEWAIT_LEN
150 * to provide reliability equal to one
151 * provided by timewait state.
152 */
153#define TCP_PAWS_WINDOW 1 /* Replay window for per-host
154 * timestamps. It must be less than
155 * minimal timewait lifetime.
156 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157/*
158 * TCP option
159 */
160
161#define TCPOPT_NOP 1 /* Padding */
162#define TCPOPT_EOL 0 /* End of options */
163#define TCPOPT_MSS 2 /* Segment size negotiating */
164#define TCPOPT_WINDOW 3 /* Window scaling */
165#define TCPOPT_SACK_PERM 4 /* SACK Permitted */
166#define TCPOPT_SACK 5 /* SACK Block */
167#define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800168#define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
170/*
171 * TCP option lengths
172 */
173
174#define TCPOLEN_MSS 4
175#define TCPOLEN_WINDOW 3
176#define TCPOLEN_SACK_PERM 2
177#define TCPOLEN_TIMESTAMP 10
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800178#define TCPOLEN_MD5SIG 18
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179
180/* But this is what stacks really send out. */
181#define TCPOLEN_TSTAMP_ALIGNED 12
182#define TCPOLEN_WSCALE_ALIGNED 4
183#define TCPOLEN_SACKPERM_ALIGNED 4
184#define TCPOLEN_SACK_BASE 2
185#define TCPOLEN_SACK_BASE_ALIGNED 4
186#define TCPOLEN_SACK_PERBLOCK 8
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800187#define TCPOLEN_MD5SIG_ALIGNED 20
Adam Langley33ad7982008-07-19 00:04:31 -0700188#define TCPOLEN_MSS_ALIGNED 4
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190/* Flags in tp->nonagle */
191#define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
192#define TCP_NAGLE_CORK 2 /* Socket is corked */
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -0800193#define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
Arnaldo Carvalho de Melo295ff7e2005-08-09 20:44:40 -0700195extern struct inet_timewait_death_row tcp_death_row;
196
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197/* sysctl variables for tcp */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198extern int sysctl_tcp_timestamps;
199extern int sysctl_tcp_window_scaling;
200extern int sysctl_tcp_sack;
201extern int sysctl_tcp_fin_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202extern int sysctl_tcp_keepalive_time;
203extern int sysctl_tcp_keepalive_probes;
204extern int sysctl_tcp_keepalive_intvl;
205extern int sysctl_tcp_syn_retries;
206extern int sysctl_tcp_synack_retries;
207extern int sysctl_tcp_retries1;
208extern int sysctl_tcp_retries2;
209extern int sysctl_tcp_orphan_retries;
210extern int sysctl_tcp_syncookies;
211extern int sysctl_tcp_retrans_collapse;
212extern int sysctl_tcp_stdurg;
213extern int sysctl_tcp_rfc1337;
214extern int sysctl_tcp_abort_on_overflow;
215extern int sysctl_tcp_max_orphans;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216extern int sysctl_tcp_fack;
217extern int sysctl_tcp_reordering;
218extern int sysctl_tcp_ecn;
219extern int sysctl_tcp_dsack;
220extern int sysctl_tcp_mem[3];
221extern int sysctl_tcp_wmem[3];
222extern int sysctl_tcp_rmem[3];
223extern int sysctl_tcp_app_win;
224extern int sysctl_tcp_adv_win_scale;
225extern int sysctl_tcp_tw_reuse;
226extern int sysctl_tcp_frto;
Ilpo Järvinen3cfe3ba2007-02-27 10:09:49 -0800227extern int sysctl_tcp_frto_response;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228extern int sysctl_tcp_low_latency;
Chris Leech95937822006-05-23 18:02:55 -0700229extern int sysctl_tcp_dma_copybreak;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230extern int sysctl_tcp_nometrics_save;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231extern int sysctl_tcp_moderate_rcvbuf;
232extern int sysctl_tcp_tso_win_divisor;
Stephen Hemminger9772efb2005-11-10 17:09:53 -0800233extern int sysctl_tcp_abc;
John Heffner5d424d52006-03-20 17:53:41 -0800234extern int sysctl_tcp_mtu_probing;
235extern int sysctl_tcp_base_mss;
Rick Jones15d99e02006-03-20 22:40:29 -0800236extern int sysctl_tcp_workaround_signed_windows;
David S. Miller35089bb2006-06-13 22:33:04 -0700237extern int sysctl_tcp_slow_start_after_idle;
John Heffner886236c2007-03-25 19:21:45 -0700238extern int sysctl_tcp_max_ssthresh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
240extern atomic_t tcp_memory_allocated;
241extern atomic_t tcp_sockets_allocated;
242extern int tcp_memory_pressure;
243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 * The next routines deal with comparing 32 bit unsigned ints
246 * and worry about wraparound (automatic with unsigned arithmetic).
247 */
248
249static inline int before(__u32 seq1, __u32 seq2)
250{
Gerrit Renker0d630cc2007-01-04 12:25:16 -0800251 return (__s32)(seq1-seq2) < 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252}
Gerrit Renker9a036b92006-12-20 10:25:55 -0800253#define after(seq2, seq1) before(seq1, seq2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
255/* is s2<=s1<=s3 ? */
256static inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
257{
258 return seq3 - seq2 >= seq1 - seq2;
259}
260
Pavel Emelianove4fd5da2007-05-29 13:19:18 -0700261static inline int tcp_too_many_orphans(struct sock *sk, int num)
262{
263 return (num > sysctl_tcp_max_orphans) ||
264 (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
265 atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2]);
266}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
268extern struct proto tcp_prot;
269
Pavel Emelyanov57ef42d2008-07-18 04:02:08 -0700270#define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field)
271#define TCP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.tcp_statistics, field)
272#define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field)
273#define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275extern void tcp_v4_err(struct sk_buff *skb, u32);
276
277extern void tcp_shutdown (struct sock *sk, int how);
278
279extern int tcp_v4_rcv(struct sk_buff *skb);
280
281extern int tcp_v4_remember_stamp(struct sock *sk);
282
Arnaldo Carvalho de Melo8feaf0c2005-08-09 20:09:30 -0700283extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
David S. Miller3516ffb2007-08-02 19:23:56 -0700285extern int tcp_sendmsg(struct kiocb *iocb, struct socket *sock,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 struct msghdr *msg, size_t size);
287extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags);
288
289extern int tcp_ioctl(struct sock *sk,
290 int cmd,
291 unsigned long arg);
292
293extern int tcp_rcv_state_process(struct sock *sk,
294 struct sk_buff *skb,
295 struct tcphdr *th,
296 unsigned len);
297
298extern int tcp_rcv_established(struct sock *sk,
299 struct sk_buff *skb,
300 struct tcphdr *th,
301 unsigned len);
302
303extern void tcp_rcv_space_adjust(struct sock *sk);
304
Chris Leech0e4b4992006-05-23 18:00:16 -0700305extern void tcp_cleanup_rbuf(struct sock *sk, int copied);
306
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800307extern int tcp_twsk_unique(struct sock *sk,
308 struct sock *sktw, void *twp);
309
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800310extern void tcp_twsk_destructor(struct sock *sk);
311
Jens Axboe9c55e012007-11-06 23:30:13 -0800312extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos,
313 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
314
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700315static inline void tcp_dec_quickack_mode(struct sock *sk,
316 const unsigned int pkts)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317{
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700318 struct inet_connection_sock *icsk = inet_csk(sk);
David S. Millerfc6415b2005-07-05 15:17:45 -0700319
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700320 if (icsk->icsk_ack.quick) {
321 if (pkts >= icsk->icsk_ack.quick) {
322 icsk->icsk_ack.quick = 0;
David S. Millerfc6415b2005-07-05 15:17:45 -0700323 /* Leaving quickack mode we deflate ATO. */
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700324 icsk->icsk_ack.ato = TCP_ATO_MIN;
David S. Millerfc6415b2005-07-05 15:17:45 -0700325 } else
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700326 icsk->icsk_ack.quick -= pkts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 }
328}
329
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700330extern void tcp_enter_quickack_mode(struct sock *sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
333{
334 rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
335}
336
Ilpo Järvinenbdf1ee52007-05-27 02:04:16 -0700337#define TCP_ECN_OK 1
338#define TCP_ECN_QUEUE_CWR 2
339#define TCP_ECN_DEMAND_CWR 4
340
341static __inline__ void
342TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th)
343{
344 if (sysctl_tcp_ecn && th->ece && th->cwr)
345 inet_rsk(req)->ecn_ok = 1;
346}
347
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348enum tcp_tw_status
349{
350 TCP_TW_SUCCESS = 0,
351 TCP_TW_RST = 1,
352 TCP_TW_ACK = 2,
353 TCP_TW_SYN = 3
354};
355
356
Arnaldo Carvalho de Melo8feaf0c2005-08-09 20:09:30 -0700357extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 struct sk_buff *skb,
Arnaldo Carvalho de Melo8feaf0c2005-08-09 20:09:30 -0700359 const struct tcphdr *th);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360
361extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700362 struct request_sock *req,
363 struct request_sock **prev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364extern int tcp_child_process(struct sock *parent,
365 struct sock *child,
366 struct sk_buff *skb);
Ilpo Järvinen46d0de42007-02-21 23:10:39 -0800367extern int tcp_use_frto(struct sock *sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368extern void tcp_enter_frto(struct sock *sk);
369extern void tcp_enter_loss(struct sock *sk, int how);
370extern void tcp_clear_retrans(struct tcp_sock *tp);
371extern void tcp_update_metrics(struct sock *sk);
372
373extern void tcp_close(struct sock *sk,
374 long timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait);
376
377extern int tcp_getsockopt(struct sock *sk, int level,
378 int optname,
379 char __user *optval,
380 int __user *optlen);
381extern int tcp_setsockopt(struct sock *sk, int level,
382 int optname, char __user *optval,
383 int optlen);
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800384extern int compat_tcp_getsockopt(struct sock *sk,
385 int level, int optname,
386 char __user *optval, int __user *optlen);
387extern int compat_tcp_setsockopt(struct sock *sk,
388 int level, int optname,
389 char __user *optval, int optlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390extern void tcp_set_keepalive(struct sock *sk, int val);
391extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
392 struct msghdr *msg,
393 size_t len, int nonblock,
394 int flags, int *addr_len);
395
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396extern void tcp_parse_options(struct sk_buff *skb,
397 struct tcp_options_received *opt_rx,
398 int estab);
399
YOSHIFUJI Hideaki7d5d5522008-04-17 12:29:53 +0900400extern u8 *tcp_parse_md5sig_option(struct tcphdr *th);
401
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402/*
403 * TCP v4 functions exported for the inet6 API
404 */
405
Arnaldo Carvalho de Melo8292a172005-12-13 23:15:52 -0800406extern void tcp_v4_send_check(struct sock *sk, int len,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 struct sk_buff *skb);
408
409extern int tcp_v4_conn_request(struct sock *sk,
410 struct sk_buff *skb);
411
412extern struct sock * tcp_create_openreq_child(struct sock *sk,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700413 struct request_sock *req,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 struct sk_buff *skb);
415
416extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk,
417 struct sk_buff *skb,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700418 struct request_sock *req,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 struct dst_entry *dst);
420
421extern int tcp_v4_do_rcv(struct sock *sk,
422 struct sk_buff *skb);
423
424extern int tcp_v4_connect(struct sock *sk,
425 struct sockaddr *uaddr,
426 int addr_len);
427
428extern int tcp_connect(struct sock *sk);
429
430extern struct sk_buff * tcp_make_synack(struct sock *sk,
431 struct dst_entry *dst,
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700432 struct request_sock *req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433
434extern int tcp_disconnect(struct sock *sk, int flags);
435
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437/* From syncookies.c */
Florian Westphal2051f112008-03-23 22:21:28 -0700438extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
440 struct ip_options *opt);
441extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
442 __u16 *mss);
443
Florian Westphal4dfc2812008-04-10 03:12:40 -0700444extern __u32 cookie_init_timestamp(struct request_sock *req);
445extern void cookie_check_timestamp(struct tcp_options_received *tcp_opt);
446
Glenn Griffinc6aefaf2008-02-07 21:49:26 -0800447/* From net/ipv6/syncookies.c */
448extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb);
449extern __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb,
450 __u16 *mss);
451
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452/* tcp_output.c */
453
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700454extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
455 int nonagle);
456extern int tcp_may_send_now(struct sock *sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);
458extern void tcp_xmit_retransmit_queue(struct sock *);
459extern void tcp_simple_retransmit(struct sock *);
460extern int tcp_trim_head(struct sock *, struct sk_buff *, u32);
David S. Miller6475be12005-09-01 22:47:01 -0700461extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462
463extern void tcp_send_probe0(struct sock *);
464extern void tcp_send_partial(struct sock *);
465extern int tcp_write_wakeup(struct sock *);
466extern void tcp_send_fin(struct sock *sk);
Al Virodd0fc662005-10-07 07:46:04 +0100467extern void tcp_send_active_reset(struct sock *sk, gfp_t priority);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468extern int tcp_send_synack(struct sock *);
David S. Millerc1b4a7e2005-07-05 15:24:38 -0700469extern void tcp_push_one(struct sock *, unsigned int mss_now);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470extern void tcp_send_ack(struct sock *sk);
471extern void tcp_send_delayed_ack(struct sock *sk);
472
David S. Millera762a982005-07-05 15:18:51 -0700473/* tcp_input.c */
474extern void tcp_cwnd_application_limited(struct sock *sk);
Ilpo Järvinen006f5822008-09-20 21:20:20 -0700475extern void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp,
476 struct sk_buff *skb);
David S. Millera762a982005-07-05 15:18:51 -0700477
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478/* tcp_timer.c */
479extern void tcp_init_xmit_timers(struct sock *);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700480static inline void tcp_clear_xmit_timers(struct sock *sk)
481{
482 inet_csk_clear_xmit_timers(sk);
483}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu);
486extern unsigned int tcp_current_mss(struct sock *sk, int large);
487
Arnaldo Carvalho de Melo17b085e2005-08-12 12:59:17 -0300488/* tcp.c */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489extern void tcp_get_info(struct sock *, struct tcp_info *);
490
491/* Read 'sendfile()'-style from a TCP socket */
492typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
493 unsigned int, size_t);
494extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
495 sk_read_actor_t recv_actor);
496
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800497extern void tcp_initialize_rcv_mss(struct sock *sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
John Heffner5d424d52006-03-20 17:53:41 -0800499extern int tcp_mtu_to_mss(struct sock *sk, int pmtu);
500extern int tcp_mss_to_mtu(struct sock *sk, int mss);
501extern void tcp_mtup_init(struct sock *sk);
502
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800503static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504{
505 tp->pred_flags = htonl((tp->tcp_header_len << 26) |
506 ntohl(TCP_FLAG_ACK) |
507 snd_wnd);
508}
509
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800510static inline void tcp_fast_path_on(struct tcp_sock *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511{
512 __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale);
513}
514
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700515static inline void tcp_fast_path_check(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700517 struct tcp_sock *tp = tcp_sk(sk);
518
David S. Millerb03efcf2005-07-08 14:57:23 -0700519 if (skb_queue_empty(&tp->out_of_order_queue) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 tp->rcv_wnd &&
521 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
522 !tp->urg_data)
523 tcp_fast_path_on(tp);
524}
525
526/* Compute the actual receive window we are currently advertising.
527 * Rcv_nxt can be after the window if our peer push more data
528 * than the offered window.
529 */
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800530static inline u32 tcp_receive_window(const struct tcp_sock *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531{
532 s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt;
533
534 if (win < 0)
535 win = 0;
536 return (u32) win;
537}
538
539/* Choose a new window, without checks for shrinking, and without
540 * scaling applied to the result. The caller does these things
541 * if necessary. This is a "raw" window selection.
542 */
543extern u32 __tcp_select_window(struct sock *sk);
544
545/* TCP timestamps are only 32-bits, this causes a slight
546 * complication on 64-bit systems since we store a snapshot
Stephen Hemminger31f34262005-11-15 15:17:10 -0800547 * of jiffies in the buffer control blocks below. We decided
548 * to use only the low 32-bits of jiffies and hide the ugly
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 * casts with the following macro.
550 */
551#define tcp_time_stamp ((__u32)(jiffies))
552
Stephen Hemmingercaa20d9a2005-11-10 17:13:47 -0800553/* This is what the send packet queuing engine uses to pass
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 * TCP per-packet control information to the transmission
555 * code. We also store the host-order sequence numbers in
556 * here too. This is 36 bytes on 32-bit architectures,
557 * 40 bytes on 64-bit machines, if this grows please adjust
558 * skbuff.h:skbuff->cb[xxx] size appropriately.
559 */
560struct tcp_skb_cb {
561 union {
562 struct inet_skb_parm h4;
563#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
564 struct inet6_skb_parm h6;
565#endif
566 } header; /* For incoming frames */
567 __u32 seq; /* Starting sequence number */
568 __u32 end_seq; /* SEQ + FIN + SYN + datalen */
569 __u32 when; /* used to compute rtt's */
570 __u8 flags; /* TCP header flags. */
571
572 /* NOTE: These must match up to the flags byte in a
573 * real TCP header.
574 */
575#define TCPCB_FLAG_FIN 0x01
576#define TCPCB_FLAG_SYN 0x02
577#define TCPCB_FLAG_RST 0x04
578#define TCPCB_FLAG_PSH 0x08
579#define TCPCB_FLAG_ACK 0x10
580#define TCPCB_FLAG_URG 0x20
581#define TCPCB_FLAG_ECE 0x40
582#define TCPCB_FLAG_CWR 0x80
583
584 __u8 sacked; /* State flags for SACK/FACK. */
585#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
586#define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
587#define TCPCB_LOST 0x04 /* SKB is lost */
588#define TCPCB_TAGBITS 0x07 /* All tag bits */
589
590#define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */
591#define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
592
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 __u16 urg_ptr; /* Valid w/URG flags is set. */
594 __u32 ack_seq; /* Sequence number ACK'd */
595};
596
597#define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
598
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599/* Due to TSO, an SKB can be composed of multiple actual
600 * packets. To keep these tracked properly, we use this.
601 */
602static inline int tcp_skb_pcount(const struct sk_buff *skb)
603{
Herbert Xu79671682006-06-22 02:40:14 -0700604 return skb_shinfo(skb)->gso_segs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605}
606
607/* This is valid iff tcp_skb_pcount() > 1. */
608static inline int tcp_skb_mss(const struct sk_buff *skb)
609{
Herbert Xu79671682006-06-22 02:40:14 -0700610 return skb_shinfo(skb)->gso_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611}
612
Ilpo Järvinenaf610b42007-06-15 12:58:38 +0300613static inline void tcp_dec_pcount_approx_int(__u32 *count, const int decr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614{
615 if (*count) {
Ilpo Järvinenaf610b42007-06-15 12:58:38 +0300616 *count -= decr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 if ((int)*count < 0)
618 *count = 0;
619 }
620}
621
Ilpo Järvinenaf610b42007-06-15 12:58:38 +0300622static inline void tcp_dec_pcount_approx(__u32 *count,
623 const struct sk_buff *skb)
624{
625 tcp_dec_pcount_approx_int(count, tcp_skb_pcount(skb));
626}
627
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700628/* Events passed to congestion control interface */
629enum tcp_ca_event {
630 CA_EVENT_TX_START, /* first transmit when no packets in flight */
631 CA_EVENT_CWND_RESTART, /* congestion window restart */
632 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
633 CA_EVENT_FRTO, /* fast recovery timeout */
634 CA_EVENT_LOSS, /* loss timeout */
635 CA_EVENT_FAST_ACK, /* in sequence ack */
636 CA_EVENT_SLOW_ACK, /* other ack */
637};
638
639/*
640 * Interface for adding new TCP congestion control handlers
641 */
642#define TCP_CA_NAME_MAX 16
Stephen Hemminger3ff825b2006-11-09 16:32:06 -0800643#define TCP_CA_MAX 128
644#define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX)
645
Stephen Hemminger164891a2007-04-23 22:26:16 -0700646#define TCP_CONG_NON_RESTRICTED 0x1
647#define TCP_CONG_RTT_STAMP 0x2
648
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700649struct tcp_congestion_ops {
650 struct list_head list;
Stephen Hemminger164891a2007-04-23 22:26:16 -0700651 unsigned long flags;
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700652
653 /* initialize private data (optional) */
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300654 void (*init)(struct sock *sk);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700655 /* cleanup private data (optional) */
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300656 void (*release)(struct sock *sk);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700657
658 /* return slow start threshold (required) */
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300659 u32 (*ssthresh)(struct sock *sk);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700660 /* lower bound for congestion window (optional) */
Stephen Hemminger72dc5b92006-06-05 17:30:08 -0700661 u32 (*min_cwnd)(const struct sock *sk);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700662 /* do new cwnd calculation (required) */
Ilpo Järvinenc3a05c62007-12-02 00:47:59 +0200663 void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700664 /* call before changing ca_state (optional) */
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300665 void (*set_state)(struct sock *sk, u8 new_state);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700666 /* call when cwnd event occurs (optional) */
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300667 void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700668 /* new value of cwnd after loss (optional) */
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300669 u32 (*undo_cwnd)(struct sock *sk);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700670 /* hook for packet ack accounting (optional) */
Stephen Hemminger30cfd0b2007-07-25 23:49:34 -0700671 void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us);
Arnaldo Carvalho de Melo73c1f4a2005-08-12 12:51:49 -0300672 /* get info for inet_diag (optional) */
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300673 void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700674
675 char name[TCP_CA_NAME_MAX];
676 struct module *owner;
677};
678
679extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
680extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
681
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300682extern void tcp_init_congestion_control(struct sock *sk);
683extern void tcp_cleanup_congestion_control(struct sock *sk);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700684extern int tcp_set_default_congestion_control(const char *name);
685extern void tcp_get_default_congestion_control(char *name);
Stephen Hemminger3ff825b2006-11-09 16:32:06 -0800686extern void tcp_get_available_congestion_control(char *buf, size_t len);
Stephen Hemmingerce7bc3b2006-11-09 16:35:15 -0800687extern void tcp_get_allowed_congestion_control(char *buf, size_t len);
688extern int tcp_set_allowed_congestion_control(char *allowed);
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300689extern int tcp_set_congestion_control(struct sock *sk, const char *name);
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800690extern void tcp_slow_start(struct tcp_sock *tp);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700691
Stephen Hemminger5f8ef482005-06-23 20:37:36 -0700692extern struct tcp_congestion_ops tcp_init_congestion_ops;
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300693extern u32 tcp_reno_ssthresh(struct sock *sk);
Ilpo Järvinenc3a05c62007-12-02 00:47:59 +0200694extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight);
Stephen Hemminger72dc5b92006-06-05 17:30:08 -0700695extern u32 tcp_reno_min_cwnd(const struct sock *sk);
David S. Millera8acfba2005-06-23 23:45:02 -0700696extern struct tcp_congestion_ops tcp_reno;
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700697
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300698static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state)
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700699{
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300700 struct inet_connection_sock *icsk = inet_csk(sk);
701
702 if (icsk->icsk_ca_ops->set_state)
703 icsk->icsk_ca_ops->set_state(sk, ca_state);
704 icsk->icsk_ca_state = ca_state;
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700705}
706
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300707static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event)
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700708{
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300709 const struct inet_connection_sock *icsk = inet_csk(sk);
710
711 if (icsk->icsk_ca_ops->cwnd_event)
712 icsk->icsk_ca_ops->cwnd_event(sk, event);
Stephen Hemminger317a76f2005-06-23 12:19:55 -0700713}
714
Ilpo Järvinene60402d2007-08-09 15:14:46 +0300715/* These functions determine how the current flow behaves in respect of SACK
716 * handling. SACK is negotiated with the peer, and therefore it can vary
717 * between different flows.
718 *
719 * tcp_is_sack - SACK enabled
720 * tcp_is_reno - No SACK
721 * tcp_is_fack - FACK enabled, implies SACK enabled
722 */
723static inline int tcp_is_sack(const struct tcp_sock *tp)
724{
725 return tp->rx_opt.sack_ok;
726}
727
728static inline int tcp_is_reno(const struct tcp_sock *tp)
729{
730 return !tcp_is_sack(tp);
731}
732
733static inline int tcp_is_fack(const struct tcp_sock *tp)
734{
735 return tp->rx_opt.sack_ok & 2;
736}
737
738static inline void tcp_enable_fack(struct tcp_sock *tp)
739{
740 tp->rx_opt.sack_ok |= 2;
741}
742
Ilpo Järvinen83ae4082007-08-09 14:37:30 +0300743static inline unsigned int tcp_left_out(const struct tcp_sock *tp)
744{
745 return tp->sacked_out + tp->lost_out;
746}
747
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748/* This determines how many packets are "in the network" to the best
749 * of our knowledge. In many cases it is conservative, but where
750 * detailed information is available from the receiver (via SACK
751 * blocks etc.) we can make more aggressive calculations.
752 *
753 * Use this for decisions involving congestion control, use just
754 * tp->packets_out to determine if the send queue is empty or not.
755 *
756 * Read this equation as:
757 *
758 * "Packets sent once on transmission queue" MINUS
759 * "Packets left network, but not honestly ACKed yet" PLUS
760 * "Packets fast retransmitted"
761 */
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800762static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763{
Ilpo Järvinen83ae4082007-08-09 14:37:30 +0300764 return tp->packets_out - tcp_left_out(tp) + tp->retrans_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765}
766
Ilpo Järvinen882beba2008-04-07 22:33:07 -0700767extern int tcp_limit_reno_sacked(struct tcp_sock *tp);
768
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
770 * The exception is rate halving phase, when cwnd is decreasing towards
771 * ssthresh.
772 */
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300773static inline __u32 tcp_current_ssthresh(const struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774{
Arnaldo Carvalho de Melo6687e982005-08-10 04:03:31 -0300775 const struct tcp_sock *tp = tcp_sk(sk);
776 if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 return tp->snd_ssthresh;
778 else
779 return max(tp->snd_ssthresh,
780 ((tp->snd_cwnd >> 1) +
781 (tp->snd_cwnd >> 2)));
782}
783
Ilpo Järvinenb9c45952007-07-27 16:36:17 +0300784/* Use define here intentionally to get WARN_ON location shown at the caller */
785#define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
Ilpo Järvinen3cfe3ba2007-02-27 10:09:49 -0800787extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst);
789
790/* Slow start with delack produces 3 packets of burst, so that
John Heffnerdd9e0dd2008-04-15 15:26:39 -0700791 * it is safe "de facto". This will be the default - same as
792 * the default reordering threshold - but if reordering increases,
793 * we must be able to allow cwnd to burst at least this much in order
794 * to not pull it back when holes are filled.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 */
796static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
797{
John Heffnerdd9e0dd2008-04-15 15:26:39 -0700798 return tp->reordering;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799}
800
Ilpo Järvinen90840de2007-12-31 04:48:41 -0800801/* Returns end sequence number of the receiver's advertised window */
802static inline u32 tcp_wnd_end(const struct tcp_sock *tp)
803{
804 return tp->snd_una + tp->snd_wnd;
805}
Ilpo Järvinencea14e02008-01-12 03:19:12 -0800806extern int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight);
Stephen Hemmingerf4805ed2005-11-10 16:53:30 -0800807
Chuck Leverc1bd24b2007-10-23 21:08:54 -0700808static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss,
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800809 const struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810{
811 if (skb->len < mss)
812 tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
813}
814
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700815static inline void tcp_check_probe_timer(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700817 struct tcp_sock *tp = tcp_sk(sk);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700818 const struct inet_connection_sock *icsk = inet_csk(sk);
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700819
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700820 if (!tp->packets_out && !icsk->icsk_pending)
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700821 inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
822 icsk->icsk_rto, TCP_RTO_MAX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823}
824
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700825static inline void tcp_push_pending_frames(struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826{
Ilpo Järvinen9e412ba2007-04-20 22:18:02 -0700827 struct tcp_sock *tp = tcp_sk(sk);
828
829 __tcp_push_pending_frames(sk, tcp_current_mss(sk, 1), tp->nonagle);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830}
831
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800832static inline void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833{
834 tp->snd_wl1 = seq;
835}
836
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800837static inline void tcp_update_wl(struct tcp_sock *tp, u32 ack, u32 seq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838{
839 tp->snd_wl1 = seq;
840}
841
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842/*
843 * Calculate(/check) TCP checksum
844 */
Frederik Deweerdtba7808e2007-02-04 20:15:27 -0800845static inline __sum16 tcp_v4_check(int len, __be32 saddr,
846 __be32 daddr, __wsum base)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847{
848 return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base);
849}
850
Al Virob51655b2006-11-14 21:40:42 -0800851static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852{
Herbert Xufb286bb2005-11-10 13:01:24 -0800853 return __skb_checksum_complete(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854}
855
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800856static inline int tcp_checksum_complete(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857{
Herbert Xu60476372007-04-09 11:59:39 -0700858 return !skb_csum_unnecessary(skb) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 __tcp_checksum_complete(skb);
860}
861
862/* Prequeue for VJ style copy to user, combined with checksumming. */
863
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800864static inline void tcp_prequeue_init(struct tcp_sock *tp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865{
866 tp->ucopy.task = NULL;
867 tp->ucopy.len = 0;
868 tp->ucopy.memory = 0;
869 skb_queue_head_init(&tp->ucopy.prequeue);
Chris Leech97fc2f02006-05-23 17:55:33 -0700870#ifdef CONFIG_NET_DMA
871 tp->ucopy.dma_chan = NULL;
872 tp->ucopy.wakeup = 0;
873 tp->ucopy.pinned_list = NULL;
874 tp->ucopy.dma_cookie = 0;
875#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876}
877
878/* Packet is added to VJ-style prequeue for processing in process
879 * context, if a reader task is waiting. Apparently, this exciting
880 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
881 * failed somewhere. Latency? Burstiness? Well, at least now we will
882 * see, why it failed. 8)8) --ANK
883 *
884 * NOTE: is this not too big to inline?
885 */
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800886static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887{
888 struct tcp_sock *tp = tcp_sk(sk);
889
890 if (!sysctl_tcp_low_latency && tp->ucopy.task) {
891 __skb_queue_tail(&tp->ucopy.prequeue, skb);
892 tp->ucopy.memory += skb->truesize;
893 if (tp->ucopy.memory > sk->sk_rcvbuf) {
894 struct sk_buff *skb1;
895
896 BUG_ON(sock_owned_by_user(sk));
897
898 while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) {
Peter Zijlstrac57943a2008-10-07 14:18:42 -0700899 sk_backlog_rcv(sk, skb1);
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700900 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPPREQUEUEDROPPED);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 }
902
903 tp->ucopy.memory = 0;
904 } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
905 wake_up_interruptible(sk->sk_sleep);
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700906 if (!inet_csk_ack_scheduled(sk))
907 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
Arnaldo Carvalho de Melo3f421ba2005-08-09 20:11:08 -0700908 (3 * TCP_RTO_MIN) / 4,
909 TCP_RTO_MAX);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 }
911 return 1;
912 }
913 return 0;
914}
915
916
917#undef STATE_TRACE
918
919#ifdef STATE_TRACE
920static const char *statename[]={
921 "Unused","Established","Syn Sent","Syn Recv",
922 "Fin Wait 1","Fin Wait 2","Time Wait", "Close",
923 "Close Wait","Last ACK","Listen","Closing"
924};
925#endif
Ilpo Järvinen490d5042008-01-12 03:17:20 -0800926extern void tcp_set_state(struct sock *sk, int state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927
Andi Kleen4ac02ba2007-04-20 17:11:46 -0700928extern void tcp_done(struct sock *sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800930static inline void tcp_sack_reset(struct tcp_options_received *rx_opt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931{
932 rx_opt->dsack = 0;
933 rx_opt->eff_sacks = 0;
934 rx_opt->num_sacks = 0;
935}
936
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937/* Determine a window scaling and initial window to offer. */
938extern void tcp_select_initial_window(int __space, __u32 mss,
939 __u32 *rcv_wnd, __u32 *window_clamp,
940 int wscale_ok, __u8 *rcv_wscale);
941
942static inline int tcp_win_from_space(int space)
943{
944 return sysctl_tcp_adv_win_scale<=0 ?
945 (space>>(-sysctl_tcp_adv_win_scale)) :
946 space - (space>>sysctl_tcp_adv_win_scale);
947}
948
949/* Note: caller must be prepared to deal with negative returns */
950static inline int tcp_space(const struct sock *sk)
951{
952 return tcp_win_from_space(sk->sk_rcvbuf -
953 atomic_read(&sk->sk_rmem_alloc));
954}
955
956static inline int tcp_full_space(const struct sock *sk)
957{
958 return tcp_win_from_space(sk->sk_rcvbuf);
959}
960
Stephen Hemminger40efc6f2006-01-03 16:03:49 -0800961static inline void tcp_openreq_init(struct request_sock *req,
962 struct tcp_options_received *rx_opt,
963 struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964{
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700965 struct inet_request_sock *ireq = inet_rsk(req);
966
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */
Florian Westphal4dfc2812008-04-10 03:12:40 -0700968 req->cookie_ts = 0;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700969 tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 req->mss = rx_opt->mss_clamp;
971 req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700972 ireq->tstamp_ok = rx_opt->tstamp_ok;
973 ireq->sack_ok = rx_opt->sack_ok;
974 ireq->snd_wscale = rx_opt->snd_wscale;
975 ireq->wscale_ok = rx_opt->wscale_ok;
976 ireq->acked = 0;
977 ireq->ecn_ok = 0;
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700978 ireq->rmt_port = tcp_hdr(skb)->source;
KOVACS Krisztiana3116ac2008-10-01 07:46:49 -0700979 ireq->loc_port = tcp_hdr(skb)->dest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980}
981
Pavel Emelyanov5c52ba12008-07-16 20:28:10 -0700982extern void tcp_enter_memory_pressure(struct sock *sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984static inline int keepalive_intvl_when(const struct tcp_sock *tp)
985{
986 return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl;
987}
988
989static inline int keepalive_time_when(const struct tcp_sock *tp)
990{
991 return tp->keepalive_time ? : sysctl_tcp_keepalive_time;
992}
993
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700994static inline int tcp_fin_time(const struct sock *sk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995{
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700996 int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout;
997 const int rto = inet_csk(sk)->icsk_rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700999 if (fin_timeout < (rto << 2) - (rto >> 1))
1000 fin_timeout = (rto << 2) - (rto >> 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001
1002 return fin_timeout;
1003}
1004
1005static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, int rst)
1006{
1007 if ((s32)(rx_opt->rcv_tsval - rx_opt->ts_recent) >= 0)
1008 return 0;
James Morris9d729f72007-03-04 16:12:44 -08001009 if (get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 return 0;
1011
1012 /* RST segments are not recommended to carry timestamp,
1013 and, if they do, it is recommended to ignore PAWS because
1014 "their cleanup function should take precedence over timestamps."
1015 Certainly, it is mistake. It is necessary to understand the reasons
1016 of this constraint to relax it: if peer reboots, clock may go
1017 out-of-sync and half-open connections will not be reset.
1018 Actually, the problem would be not existing if all
1019 the implementations followed draft about maintaining clock
1020 via reboots. Linux-2.2 DOES NOT!
1021
1022 However, we can relax time bounds for RST segments to MSL.
1023 */
James Morris9d729f72007-03-04 16:12:44 -08001024 if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025 return 0;
1026 return 1;
1027}
1028
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029#define TCP_CHECK_TIMER(sk) do { } while (0)
1030
Pavel Emelyanova9c19322008-07-16 20:21:42 -07001031static inline void tcp_mib_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032{
1033 /* See RFC 2012 */
Pavel Emelyanovcf1100a2008-07-16 20:27:38 -07001034 TCP_ADD_STATS_USER(net, TCP_MIB_RTOALGORITHM, 1);
1035 TCP_ADD_STATS_USER(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ);
1036 TCP_ADD_STATS_USER(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ);
1037 TCP_ADD_STATS_USER(net, TCP_MIB_MAXCONN, -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038}
1039
Ilpo Järvinen5af4ec22007-09-20 11:30:48 -07001040/* from STCP */
Ilpo Järvinenef9da472008-09-20 21:25:15 -07001041static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp)
David S. Miller0800f172007-09-20 11:40:37 -07001042{
Stephen Hemminger6a438bb2005-11-10 17:14:59 -08001043 tp->lost_skb_hint = NULL;
1044 tp->scoreboard_skb_hint = NULL;
Ilpo Järvinenef9da472008-09-20 21:25:15 -07001045}
1046
1047static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp)
1048{
1049 tcp_clear_retrans_hints_partial(tp);
Stephen Hemminger6a438bb2005-11-10 17:14:59 -08001050 tp->retransmit_skb_hint = NULL;
Ilpo Järvinenb7689202007-09-20 11:37:19 -07001051}
1052
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001053/* MD5 Signature */
1054struct crypto_hash;
1055
1056/* - key database */
1057struct tcp_md5sig_key {
1058 u8 *key;
1059 u8 keylen;
1060};
1061
1062struct tcp4_md5sig_key {
David S. Millerf8ab18d2007-09-28 15:18:35 -07001063 struct tcp_md5sig_key base;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001064 __be32 addr;
1065};
1066
1067struct tcp6_md5sig_key {
David S. Millerf8ab18d2007-09-28 15:18:35 -07001068 struct tcp_md5sig_key base;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001069#if 0
1070 u32 scope_id; /* XXX */
1071#endif
1072 struct in6_addr addr;
1073};
1074
1075/* - sock block */
1076struct tcp_md5sig_info {
1077 struct tcp4_md5sig_key *keys4;
1078#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1079 struct tcp6_md5sig_key *keys6;
1080 u32 entries6;
1081 u32 alloced6;
1082#endif
1083 u32 entries4;
1084 u32 alloced4;
1085};
1086
1087/* - pseudo header */
1088struct tcp4_pseudohdr {
1089 __be32 saddr;
1090 __be32 daddr;
1091 __u8 pad;
1092 __u8 protocol;
1093 __be16 len;
1094};
1095
1096struct tcp6_pseudohdr {
1097 struct in6_addr saddr;
1098 struct in6_addr daddr;
1099 __be32 len;
1100 __be32 protocol; /* including padding */
1101};
1102
1103union tcp_md5sum_block {
1104 struct tcp4_pseudohdr ip4;
1105#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1106 struct tcp6_pseudohdr ip6;
1107#endif
1108};
1109
1110/* - pool: digest algorithm, hash description and scratch buffer */
1111struct tcp_md5sig_pool {
1112 struct hash_desc md5_desc;
1113 union tcp_md5sum_block md5_blk;
1114};
1115
1116#define TCP_MD5SIG_MAXKEYS (~(u32)0) /* really?! */
1117
1118/* - functions */
Adam Langley49a72df2008-07-19 00:01:42 -07001119extern int tcp_v4_md5_hash_skb(char *md5_hash,
1120 struct tcp_md5sig_key *key,
1121 struct sock *sk,
1122 struct request_sock *req,
1123 struct sk_buff *skb);
YOSHIFUJI Hideaki8d26d762008-04-17 13:19:16 +09001124
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001125extern struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
1126 struct sock *addr_sk);
1127
1128extern int tcp_v4_md5_do_add(struct sock *sk,
1129 __be32 addr,
1130 u8 *newkey,
1131 u8 newkeylen);
1132
1133extern int tcp_v4_md5_do_del(struct sock *sk,
Al Viro8e5200f2006-11-20 18:06:37 -08001134 __be32 addr);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001135
YOSHIFUJI Hideaki9501f972008-04-18 12:45:16 +09001136#ifdef CONFIG_TCP_MD5SIG
1137#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_keylen ? \
1138 &(struct tcp_md5sig_key) { \
1139 .key = (twsk)->tw_md5_key, \
1140 .keylen = (twsk)->tw_md5_keylen, \
1141 } : NULL)
1142#else
1143#define tcp_twsk_md5_key(twsk) NULL
1144#endif
1145
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001146extern struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void);
1147extern void tcp_free_md5sig_pool(void);
1148
1149extern struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu);
1150extern void __tcp_put_md5sig_pool(void);
Adam Langley49a72df2008-07-19 00:01:42 -07001151extern int tcp_md5_hash_header(struct tcp_md5sig_pool *, struct tcphdr *);
1152extern int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, struct sk_buff *,
1153 unsigned header_len);
1154extern int tcp_md5_hash_key(struct tcp_md5sig_pool *hp,
1155 struct tcp_md5sig_key *key);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001156
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
David S. Millerfe067e82007-03-07 12:12:44 -08001173/* 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)
Hideo Aoki3ab224b2007-12-31 00:11:19 -08001179 sk_wmem_free_skb(sk, skb);
1180 sk_mem_reclaim(sk);
David S. Millerfe067e82007-03-07 12:12:44 -08001181}
1182
1183static inline struct sk_buff *tcp_write_queue_head(struct sock *sk)
1184{
David S. Millercd07a8e2008-09-23 00:50:13 -07001185 return skb_peek(&sk->sk_write_queue);
David S. Millerfe067e82007-03-07 12:12:44 -08001186}
1187
1188static inline struct sk_buff *tcp_write_queue_tail(struct sock *sk)
1189{
David S. Millercd07a8e2008-09-23 00:50:13 -07001190 return skb_peek_tail(&sk->sk_write_queue);
David S. Millerfe067e82007-03-07 12:12:44 -08001191}
1192
1193static inline struct sk_buff *tcp_write_queue_next(struct sock *sk, struct sk_buff *skb)
1194{
David S. Millercd07a8e2008-09-23 00:50:13 -07001195 return skb_queue_next(&sk->sk_write_queue, skb);
David S. Millerfe067e82007-03-07 12:12:44 -08001196}
1197
1198#define tcp_for_write_queue(skb, sk) \
David S. Millercd07a8e2008-09-23 00:50:13 -07001199 skb_queue_walk(&(sk)->sk_write_queue, skb)
David S. Millerfe067e82007-03-07 12:12:44 -08001200
1201#define tcp_for_write_queue_from(skb, sk) \
David S. Millercd07a8e2008-09-23 00:50:13 -07001202 skb_queue_walk_from(&(sk)->sk_write_queue, skb)
David S. Millerfe067e82007-03-07 12:12:44 -08001203
Ilpo Järvinen234b6862007-12-02 00:48:02 +02001204#define tcp_for_write_queue_from_safe(skb, tmp, sk) \
David S. Millercd07a8e2008-09-23 00:50:13 -07001205 skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp)
Ilpo Järvinen234b6862007-12-02 00:48:02 +02001206
David S. Millerfe067e82007-03-07 12:12:44 -08001207static inline struct sk_buff *tcp_send_head(struct sock *sk)
1208{
1209 return sk->sk_send_head;
1210}
1211
David S. Millercd07a8e2008-09-23 00:50:13 -07001212static inline bool tcp_skb_is_last(const struct sock *sk,
1213 const struct sk_buff *skb)
1214{
1215 return skb_queue_is_last(&sk->sk_write_queue, skb);
1216}
1217
David S. Millerfe067e82007-03-07 12:12:44 -08001218static inline void tcp_advance_send_head(struct sock *sk, struct sk_buff *skb)
1219{
David S. Millercd07a8e2008-09-23 00:50:13 -07001220 if (tcp_skb_is_last(sk, skb))
David S. Millerfe067e82007-03-07 12:12:44 -08001221 sk->sk_send_head = NULL;
David S. Millercd07a8e2008-09-23 00:50:13 -07001222 else
1223 sk->sk_send_head = tcp_write_queue_next(sk, skb);
David S. Millerfe067e82007-03-07 12:12:44 -08001224}
1225
1226static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked)
1227{
1228 if (sk->sk_send_head == skb_unlinked)
1229 sk->sk_send_head = NULL;
1230}
1231
1232static inline void tcp_init_send_head(struct sock *sk)
1233{
1234 sk->sk_send_head = NULL;
1235}
1236
1237static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
1238{
1239 __skb_queue_tail(&sk->sk_write_queue, skb);
1240}
1241
1242static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
1243{
1244 __tcp_add_write_queue_tail(sk, skb);
1245
1246 /* Queue it, remembering where we must start sending. */
Ilpo Järvinen6859d492007-12-02 00:48:06 +02001247 if (sk->sk_send_head == NULL) {
David S. Millerfe067e82007-03-07 12:12:44 -08001248 sk->sk_send_head = skb;
Ilpo Järvinen6859d492007-12-02 00:48:06 +02001249
1250 if (tcp_sk(sk)->highest_sack == NULL)
1251 tcp_sk(sk)->highest_sack = skb;
1252 }
David S. Millerfe067e82007-03-07 12:12:44 -08001253}
1254
1255static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb)
1256{
1257 __skb_queue_head(&sk->sk_write_queue, skb);
1258}
1259
1260/* Insert buff after skb on the write queue of sk. */
1261static inline void tcp_insert_write_queue_after(struct sk_buff *skb,
1262 struct sk_buff *buff,
1263 struct sock *sk)
1264{
Gerrit Renker7de6c032008-04-14 00:05:09 -07001265 __skb_queue_after(&sk->sk_write_queue, skb, buff);
David S. Millerfe067e82007-03-07 12:12:44 -08001266}
1267
David S. Miller43f59c82008-09-21 21:28:51 -07001268/* Insert new before skb on the write queue of sk. */
David S. Millerfe067e82007-03-07 12:12:44 -08001269static inline void tcp_insert_write_queue_before(struct sk_buff *new,
1270 struct sk_buff *skb,
1271 struct sock *sk)
1272{
David S. Miller43f59c82008-09-21 21:28:51 -07001273 __skb_queue_before(&sk->sk_write_queue, skb, new);
Ilpo Järvinen6e421412007-11-19 23:24:09 -08001274
1275 if (sk->sk_send_head == skb)
1276 sk->sk_send_head = new;
David S. Millerfe067e82007-03-07 12:12:44 -08001277}
1278
1279static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk)
1280{
1281 __skb_unlink(skb, &sk->sk_write_queue);
1282}
1283
David S. Millerfe067e82007-03-07 12:12:44 -08001284static inline int tcp_write_queue_empty(struct sock *sk)
1285{
1286 return skb_queue_empty(&sk->sk_write_queue);
1287}
1288
Ilpo Järvinena47e5a92007-11-15 19:41:46 -08001289/* Start sequence of the highest skb with SACKed bit, valid only if
1290 * sacked > 0 or when the caller has ensured validity by itself.
1291 */
1292static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp)
1293{
1294 if (!tp->sacked_out)
1295 return tp->snd_una;
Ilpo Järvinen6859d492007-12-02 00:48:06 +02001296
1297 if (tp->highest_sack == NULL)
1298 return tp->snd_nxt;
1299
Ilpo Järvinena47e5a92007-11-15 19:41:46 -08001300 return TCP_SKB_CB(tp->highest_sack)->seq;
1301}
1302
Ilpo Järvinen6859d492007-12-02 00:48:06 +02001303static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb)
1304{
1305 tcp_sk(sk)->highest_sack = tcp_skb_is_last(sk, skb) ? NULL :
1306 tcp_write_queue_next(sk, skb);
1307}
1308
1309static inline struct sk_buff *tcp_highest_sack(struct sock *sk)
1310{
1311 return tcp_sk(sk)->highest_sack;
1312}
1313
1314static inline void tcp_highest_sack_reset(struct sock *sk)
1315{
1316 tcp_sk(sk)->highest_sack = tcp_write_queue_head(sk);
1317}
1318
1319/* Called when old skb is about to be deleted (to be combined with new skb) */
1320static inline void tcp_highest_sack_combine(struct sock *sk,
1321 struct sk_buff *old,
1322 struct sk_buff *new)
1323{
1324 if (tcp_sk(sk)->sacked_out && (old == tcp_sk(sk)->highest_sack))
1325 tcp_sk(sk)->highest_sack = new;
1326}
1327
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328/* /proc */
1329enum tcp_seq_states {
1330 TCP_SEQ_STATE_LISTENING,
1331 TCP_SEQ_STATE_OPENREQ,
1332 TCP_SEQ_STATE_ESTABLISHED,
1333 TCP_SEQ_STATE_TIME_WAIT,
1334};
1335
1336struct tcp_seq_afinfo {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 char *name;
1338 sa_family_t family;
Denis V. Lunev68fcadd2008-04-13 22:13:30 -07001339 struct file_operations seq_fops;
Denis V. Lunev9427c4b2008-04-13 22:12:13 -07001340 struct seq_operations seq_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341};
1342
1343struct tcp_iter_state {
Denis V. Luneva4146b12008-04-13 22:11:14 -07001344 struct seq_net_private p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 sa_family_t family;
1346 enum tcp_seq_states state;
1347 struct sock *syn_wait_sk;
1348 int bucket, sbucket, num, uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349};
1350
Daniel Lezcano6f8b13b2008-03-21 04:14:45 -07001351extern int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo);
1352extern void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -03001354extern struct request_sock_ops tcp_request_sock_ops;
Glenn Griffinc6aefaf2008-02-07 21:49:26 -08001355extern struct request_sock_ops tcp6_request_sock_ops;
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -03001356
Brian Haley7d06b2e2008-06-14 17:04:49 -07001357extern void tcp_v4_destroy_sock(struct sock *sk);
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -03001358
Herbert Xua430a432006-07-08 13:34:56 -07001359extern int tcp_v4_gso_send_check(struct sk_buff *skb);
Herbert Xu576a30e2006-06-27 13:22:38 -07001360extern struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features);
Herbert Xuf4c50d92006-06-22 03:02:40 -07001361
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -03001362#ifdef CONFIG_PROC_FS
1363extern int tcp4_proc_init(void);
1364extern void tcp4_proc_exit(void);
1365#endif
1366
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001367/* TCP af-specific functions */
1368struct tcp_sock_af_ops {
1369#ifdef CONFIG_TCP_MD5SIG
1370 struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
1371 struct sock *addr_sk);
1372 int (*calc_md5_hash) (char *location,
1373 struct tcp_md5sig_key *md5,
1374 struct sock *sk,
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001375 struct request_sock *req,
Adam Langley49a72df2008-07-19 00:01:42 -07001376 struct sk_buff *skb);
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -08001377 int (*md5_add) (struct sock *sk,
1378 struct sock *addr_sk,
1379 u8 *newkey,
1380 u8 len);
1381 int (*md5_parse) (struct sock *sk,
1382 char __user *optval,
1383 int optlen);
1384#endif
1385};
1386
1387struct tcp_request_sock_ops {
1388#ifdef CONFIG_TCP_MD5SIG
1389 struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
1390 struct request_sock *req);
1391#endif
1392};
1393
Denis V. Lunev9b0f9762008-02-29 11:13:15 -08001394extern void tcp_v4_init(void);
Arnaldo Carvalho de Melo20380732005-08-16 02:18:02 -03001395extern void tcp_init(void);
1396
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397#endif /* _TCP_H */