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[BNX2]: Update version
[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/config.h>
25#include <linux/list.h>
26#include <linux/tcp.h>
27#include <linux/slab.h>
28#include <linux/cache.h>
29#include <linux/percpu.h>
fb286bb2 30#include <linux/skbuff.h>
3f421baa
ACM		 31
32#include <net/inet_connection_sock.h>
295ff7ed 33#include <net/inet_timewait_sock.h>
77d8bf9c 34#include <net/inet_hashtables.h>
1da177e4 35#include <net/checksum.h>
2e6599cb 36#include <net/request_sock.h>
1da177e4
LT		 37#include <net/sock.h>
38#include <net/snmp.h>
39#include <net/ip.h>
c752f073
ACM		 40#include <net/tcp_states.h>
41
1da177e4
LT		 42#include <linux/seq_file.h>
43
6e04e021 44extern struct inet_hashinfo tcp_hashinfo;
1da177e4 45
1da177e4 46extern atomic_t tcp_orphan_count;
1da177e4 47extern void tcp_time_wait(struct sock *sk, int state, int timeo);
1da177e4 48
1da177e4
LT		 49#define MAX_TCP_HEADER (128 + MAX_HEADER)
50
51/*
52 * Never offer a window over 32767 without using window scaling. Some
53 * poor stacks do signed 16bit maths!
54 */
55#define MAX_TCP_WINDOW 32767U
56
57/* Minimal accepted MSS. It is (60+60+8) - (20+20). */
58#define TCP_MIN_MSS 88U
59
60/* Minimal RCV_MSS. */
61#define TCP_MIN_RCVMSS 536U
62
63/* After receiving this amount of duplicate ACKs fast retransmit starts. */
64#define TCP_FASTRETRANS_THRESH 3
65
66/* Maximal reordering. */
67#define TCP_MAX_REORDERING 127
68
69/* Maximal number of ACKs sent quickly to accelerate slow-start. */
70#define TCP_MAX_QUICKACKS 16U
71
72/* urg_data states */
73#define TCP_URG_VALID 0x0100
74#define TCP_URG_NOTYET 0x0200
75#define TCP_URG_READ 0x0400
76
77#define TCP_RETR1 3 /*
78 * This is how many retries it does before it
79 * tries to figure out if the gateway is
80 * down. Minimal RFC value is 3; it corresponds
81 * to ~3sec-8min depending on RTO.
82 */
83
84#define TCP_RETR2 15 /*
85 * This should take at least
86 * 90 minutes to time out.
87 * RFC1122 says that the limit is 100 sec.
88 * 15 is ~13-30min depending on RTO.
89 */
90
91#define TCP_SYN_RETRIES 5 /* number of times to retry active opening a
caa20d9a 92 * connection: ~180sec is RFC minimum */
1da177e4
LT		 93
94#define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a
caa20d9a 95 * connection: ~180sec is RFC minimum */
1da177e4
LT		 96
97
98#define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned
99 * socket. 7 is ~50sec-16min.
100 */
101
102
103#define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT
104 * state, about 60 seconds */
105#define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN
106 /* BSD style FIN_WAIT2 deadlock breaker.
107 * It used to be 3min, new value is 60sec,
108 * to combine FIN-WAIT-2 timeout with
109 * TIME-WAIT timer.
110 */
111
112#define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */
113#if HZ >= 100
114#define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */
115#define TCP_ATO_MIN ((unsigned)(HZ/25))
116#else
117#define TCP_DELACK_MIN 4U
118#define TCP_ATO_MIN 4U
119#endif
120#define TCP_RTO_MAX ((unsigned)(120*HZ))
121#define TCP_RTO_MIN ((unsigned)(HZ/5))
122#define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */
123
124#define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
125 * for local resources.
126 */
127
128#define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */
129#define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */
130#define TCP_KEEPALIVE_INTVL (75*HZ)
131
132#define MAX_TCP_KEEPIDLE 32767
133#define MAX_TCP_KEEPINTVL 32767
134#define MAX_TCP_KEEPCNT 127
135#define MAX_TCP_SYNCNT 127
136
137#define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */
138#define TCP_SYNQ_HSIZE 512 /* Size of SYNACK hash table */
139
140#define TCP_PAWS_24DAYS (60 * 60 * 24 * 24)
141#define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated
142 * after this time. It should be equal
143 * (or greater than) TCP_TIMEWAIT_LEN
144 * to provide reliability equal to one
145 * provided by timewait state.
146 */
147#define TCP_PAWS_WINDOW 1 /* Replay window for per-host
148 * timestamps. It must be less than
149 * minimal timewait lifetime.
150 */
1da177e4
LT		 151/*
152 * TCP option
153 */
154
155#define TCPOPT_NOP 1 /* Padding */
156#define TCPOPT_EOL 0 /* End of options */
157#define TCPOPT_MSS 2 /* Segment size negotiating */
158#define TCPOPT_WINDOW 3 /* Window scaling */
159#define TCPOPT_SACK_PERM 4 /* SACK Permitted */
160#define TCPOPT_SACK 5 /* SACK Block */
161#define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
162
163/*
164 * TCP option lengths
165 */
166
167#define TCPOLEN_MSS 4
168#define TCPOLEN_WINDOW 3
169#define TCPOLEN_SACK_PERM 2
170#define TCPOLEN_TIMESTAMP 10
171
172/* But this is what stacks really send out. */
173#define TCPOLEN_TSTAMP_ALIGNED 12
174#define TCPOLEN_WSCALE_ALIGNED 4
175#define TCPOLEN_SACKPERM_ALIGNED 4
176#define TCPOLEN_SACK_BASE 2
177#define TCPOLEN_SACK_BASE_ALIGNED 4
178#define TCPOLEN_SACK_PERBLOCK 8
179
1da177e4
LT		 180/* Flags in tp->nonagle */
181#define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
182#define TCP_NAGLE_CORK 2 /* Socket is corked */
caa20d9a 183#define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */
1da177e4 184
295ff7ed
ACM		 185extern struct inet_timewait_death_row tcp_death_row;
186
1da177e4 187/* sysctl variables for tcp */
1da177e4
LT		 188extern int sysctl_tcp_timestamps;
189extern int sysctl_tcp_window_scaling;
190extern int sysctl_tcp_sack;
191extern int sysctl_tcp_fin_timeout;
1da177e4
LT		 192extern int sysctl_tcp_keepalive_time;
193extern int sysctl_tcp_keepalive_probes;
194extern int sysctl_tcp_keepalive_intvl;
195extern int sysctl_tcp_syn_retries;
196extern int sysctl_tcp_synack_retries;
197extern int sysctl_tcp_retries1;
198extern int sysctl_tcp_retries2;
199extern int sysctl_tcp_orphan_retries;
200extern int sysctl_tcp_syncookies;
201extern int sysctl_tcp_retrans_collapse;
202extern int sysctl_tcp_stdurg;
203extern int sysctl_tcp_rfc1337;
204extern int sysctl_tcp_abort_on_overflow;
205extern int sysctl_tcp_max_orphans;
1da177e4
LT		 206extern int sysctl_tcp_fack;
207extern int sysctl_tcp_reordering;
208extern int sysctl_tcp_ecn;
209extern int sysctl_tcp_dsack;
210extern int sysctl_tcp_mem[3];
211extern int sysctl_tcp_wmem[3];
212extern int sysctl_tcp_rmem[3];
213extern int sysctl_tcp_app_win;
214extern int sysctl_tcp_adv_win_scale;
215extern int sysctl_tcp_tw_reuse;
216extern int sysctl_tcp_frto;
217extern int sysctl_tcp_low_latency;
1da177e4 218extern int sysctl_tcp_nometrics_save;
1da177e4
LT		 219extern int sysctl_tcp_moderate_rcvbuf;
220extern int sysctl_tcp_tso_win_divisor;
9772efb9 221extern int sysctl_tcp_abc;
1da177e4
LT		 222
223extern atomic_t tcp_memory_allocated;
224extern atomic_t tcp_sockets_allocated;
225extern int tcp_memory_pressure;
226
1da177e4
LT		 227/*
228 * The next routines deal with comparing 32 bit unsigned ints
229 * and worry about wraparound (automatic with unsigned arithmetic).
230 */
231
232static inline int before(__u32 seq1, __u32 seq2)
233{
234 return (__s32)(seq1-seq2) < 0;
235}
236
237static inline int after(__u32 seq1, __u32 seq2)
238{
239 return (__s32)(seq2-seq1) < 0;
240}
241
242
243/* is s2<=s1<=s3 ? */
244static inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
245{
246 return seq3 - seq2 >= seq1 - seq2;
247}
248
249
250extern struct proto tcp_prot;
251
252DECLARE_SNMP_STAT(struct tcp_mib, tcp_statistics);
253#define TCP_INC_STATS(field) SNMP_INC_STATS(tcp_statistics, field)
254#define TCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(tcp_statistics, field)
255#define TCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(tcp_statistics, field)
256#define TCP_DEC_STATS(field) SNMP_DEC_STATS(tcp_statistics, field)
257#define TCP_ADD_STATS_BH(field, val) SNMP_ADD_STATS_BH(tcp_statistics, field, val)
258#define TCP_ADD_STATS_USER(field, val) SNMP_ADD_STATS_USER(tcp_statistics, field, val)
259
1da177e4
LT		 260extern void tcp_v4_err(struct sk_buff *skb, u32);
261
262extern void tcp_shutdown (struct sock *sk, int how);
263
264extern int tcp_v4_rcv(struct sk_buff *skb);
265
266extern int tcp_v4_remember_stamp(struct sock *sk);
267
8feaf0c0 268extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
1da177e4
LT		 269
270extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk,
271 struct msghdr *msg, size_t size);
272extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags);
273
274extern int tcp_ioctl(struct sock *sk,
275 int cmd,
276 unsigned long arg);
277
278extern int tcp_rcv_state_process(struct sock *sk,
279 struct sk_buff *skb,
280 struct tcphdr *th,
281 unsigned len);
282
283extern int tcp_rcv_established(struct sock *sk,
284 struct sk_buff *skb,
285 struct tcphdr *th,
286 unsigned len);
287
288extern void tcp_rcv_space_adjust(struct sock *sk);
289
6d6ee43e
ACM		 290extern int tcp_twsk_unique(struct sock *sk,
291 struct sock *sktw, void *twp);
292
463c84b9
ACM		 293static inline void tcp_dec_quickack_mode(struct sock *sk,
294 const unsigned int pkts)
1da177e4 295{
463c84b9 296 struct inet_connection_sock *icsk = inet_csk(sk);
fc6415bc 297
463c84b9
ACM		 298 if (icsk->icsk_ack.quick) {
299 if (pkts >= icsk->icsk_ack.quick) {
300 icsk->icsk_ack.quick = 0;
fc6415bc 301 /* Leaving quickack mode we deflate ATO. */
463c84b9 302 icsk->icsk_ack.ato = TCP_ATO_MIN;
fc6415bc 303 } else
463c84b9 304 icsk->icsk_ack.quick -= pkts;
1da177e4
LT		 305 }
306}
307
463c84b9 308extern void tcp_enter_quickack_mode(struct sock *sk);
1da177e4 309
1da177e4
LT		 310static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
311{
312 rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
313}
314
315enum tcp_tw_status
316{
317 TCP_TW_SUCCESS = 0,
318 TCP_TW_RST = 1,
319 TCP_TW_ACK = 2,
320 TCP_TW_SYN = 3
321};
322
323
8feaf0c0 324extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw,
1da177e4 325 struct sk_buff *skb,
8feaf0c0 326 const struct tcphdr *th);
1da177e4
LT		 327
328extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb,
60236fdd
ACM		 329 struct request_sock *req,
330 struct request_sock **prev);
1da177e4
LT		 331extern int tcp_child_process(struct sock *parent,
332 struct sock *child,
333 struct sk_buff *skb);
334extern void tcp_enter_frto(struct sock *sk);
335extern void tcp_enter_loss(struct sock *sk, int how);
336extern void tcp_clear_retrans(struct tcp_sock *tp);
337extern void tcp_update_metrics(struct sock *sk);
338
339extern void tcp_close(struct sock *sk,
340 long timeout);
1da177e4
LT		 341extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait);
342
343extern int tcp_getsockopt(struct sock *sk, int level,
344 int optname,
345 char __user *optval,
346 int __user *optlen);
347extern int tcp_setsockopt(struct sock *sk, int level,
348 int optname, char __user *optval,
349 int optlen);
350extern void tcp_set_keepalive(struct sock *sk, int val);
351extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
352 struct msghdr *msg,
353 size_t len, int nonblock,
354 int flags, int *addr_len);
355
1da177e4
LT		 356extern void tcp_parse_options(struct sk_buff *skb,
357 struct tcp_options_received *opt_rx,
358 int estab);
359
360/*
361 * TCP v4 functions exported for the inet6 API
362 */
363
8292a17a 364extern void tcp_v4_send_check(struct sock *sk, int len,
1da177e4
LT		 365 struct sk_buff *skb);
366
367extern int tcp_v4_conn_request(struct sock *sk,
368 struct sk_buff *skb);
369
370extern struct sock * tcp_create_openreq_child(struct sock *sk,
60236fdd 371 struct request_sock *req,
1da177e4
LT		 372 struct sk_buff *skb);
373
374extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk,
375 struct sk_buff *skb,
60236fdd 376 struct request_sock *req,
1da177e4
LT		 377 struct dst_entry *dst);
378
379extern int tcp_v4_do_rcv(struct sock *sk,
380 struct sk_buff *skb);
381
382extern int tcp_v4_connect(struct sock *sk,
383 struct sockaddr *uaddr,
384 int addr_len);
385
386extern int tcp_connect(struct sock *sk);
387
388extern struct sk_buff * tcp_make_synack(struct sock *sk,
389 struct dst_entry *dst,
60236fdd 390 struct request_sock *req);
1da177e4
LT		 391
392extern int tcp_disconnect(struct sock *sk, int flags);
393
394extern void tcp_unhash(struct sock *sk);
395
396extern int tcp_v4_hash_connecting(struct sock *sk);
397
398
399/* From syncookies.c */
400extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
401 struct ip_options *opt);
402extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
403 __u16 *mss);
404
405/* tcp_output.c */
406
f6302d1d 407extern void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp,
a2e2a59c 408 unsigned int cur_mss, int nonagle);
f6302d1d 409extern int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp);
1da177e4
LT		 410extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);
411extern void tcp_xmit_retransmit_queue(struct sock *);
412extern void tcp_simple_retransmit(struct sock *);
413extern int tcp_trim_head(struct sock *, struct sk_buff *, u32);
6475be16 414extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int);
1da177e4
LT		 415
416extern void tcp_send_probe0(struct sock *);
417extern void tcp_send_partial(struct sock *);
418extern int tcp_write_wakeup(struct sock *);
419extern void tcp_send_fin(struct sock *sk);
dd0fc66f 420extern void tcp_send_active_reset(struct sock *sk, gfp_t priority);
1da177e4 421extern int tcp_send_synack(struct sock *);
c1b4a7e6 422extern void tcp_push_one(struct sock *, unsigned int mss_now);
1da177e4
LT		 423extern void tcp_send_ack(struct sock *sk);
424extern void tcp_send_delayed_ack(struct sock *sk);
425
a762a980
DM		 426/* tcp_input.c */
427extern void tcp_cwnd_application_limited(struct sock *sk);
428
1da177e4
LT		 429/* tcp_timer.c */
430extern void tcp_init_xmit_timers(struct sock *);
463c84b9
ACM		 431static inline void tcp_clear_xmit_timers(struct sock *sk)
432{
433 inet_csk_clear_xmit_timers(sk);
434}
1da177e4 435
1da177e4
LT		 436extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu);
437extern unsigned int tcp_current_mss(struct sock *sk, int large);
438
17b085ea 439/* tcp.c */
1da177e4
LT		 440extern void tcp_get_info(struct sock *, struct tcp_info *);
441
442/* Read 'sendfile()'-style from a TCP socket */
443typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
444 unsigned int, size_t);
445extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
446 sk_read_actor_t recv_actor);
447
40efc6fa 448extern void tcp_initialize_rcv_mss(struct sock *sk);
1da177e4 449
40efc6fa 450static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd)
1da177e4
LT		 451{
452 tp->pred_flags = htonl((tp->tcp_header_len << 26) |
453 ntohl(TCP_FLAG_ACK) |
454 snd_wnd);
455}
456
40efc6fa 457static inline void tcp_fast_path_on(struct tcp_sock *tp)
1da177e4
LT		 458{
459 __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale);
460}
461
462static inline void tcp_fast_path_check(struct sock *sk, struct tcp_sock *tp)
463{
b03efcfb 464 if (skb_queue_empty(&tp->out_of_order_queue) &&
1da177e4
LT		 465 tp->rcv_wnd &&
466 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
467 !tp->urg_data)
468 tcp_fast_path_on(tp);
469}
470
471/* Compute the actual receive window we are currently advertising.
472 * Rcv_nxt can be after the window if our peer push more data
473 * than the offered window.
474 */
40efc6fa 475static inline u32 tcp_receive_window(const struct tcp_sock *tp)
1da177e4
LT		 476{
477 s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt;
478
479 if (win < 0)
480 win = 0;
481 return (u32) win;
482}
483
484/* Choose a new window, without checks for shrinking, and without
485 * scaling applied to the result. The caller does these things
486 * if necessary. This is a "raw" window selection.
487 */
488extern u32 __tcp_select_window(struct sock *sk);
489
490/* TCP timestamps are only 32-bits, this causes a slight
491 * complication on 64-bit systems since we store a snapshot
31f34269
SH		 492 * of jiffies in the buffer control blocks below. We decided
493 * to use only the low 32-bits of jiffies and hide the ugly
1da177e4
LT		 494 * casts with the following macro.
495 */
496#define tcp_time_stamp ((__u32)(jiffies))
497
caa20d9a 498/* This is what the send packet queuing engine uses to pass
1da177e4
LT		 499 * TCP per-packet control information to the transmission
500 * code. We also store the host-order sequence numbers in
501 * here too. This is 36 bytes on 32-bit architectures,
502 * 40 bytes on 64-bit machines, if this grows please adjust
503 * skbuff.h:skbuff->cb[xxx] size appropriately.
504 */
505struct tcp_skb_cb {
506 union {
507 struct inet_skb_parm h4;
508#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
509 struct inet6_skb_parm h6;
510#endif
511 } header; /* For incoming frames */
512 __u32 seq; /* Starting sequence number */
513 __u32 end_seq; /* SEQ + FIN + SYN + datalen */
514 __u32 when; /* used to compute rtt's */
515 __u8 flags; /* TCP header flags. */
516
517 /* NOTE: These must match up to the flags byte in a
518 * real TCP header.
519 */
520#define TCPCB_FLAG_FIN 0x01
521#define TCPCB_FLAG_SYN 0x02
522#define TCPCB_FLAG_RST 0x04
523#define TCPCB_FLAG_PSH 0x08
524#define TCPCB_FLAG_ACK 0x10
525#define TCPCB_FLAG_URG 0x20
526#define TCPCB_FLAG_ECE 0x40
527#define TCPCB_FLAG_CWR 0x80
528
529 __u8 sacked; /* State flags for SACK/FACK. */
530#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
531#define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
532#define TCPCB_LOST 0x04 /* SKB is lost */
533#define TCPCB_TAGBITS 0x07 /* All tag bits */
534
535#define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */
536#define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
537
caa20d9a 538#define TCPCB_URG 0x20 /* Urgent pointer advanced here */
1da177e4
LT		 539
540#define TCPCB_AT_TAIL (TCPCB_URG)
541
542 __u16 urg_ptr; /* Valid w/URG flags is set. */
543 __u32 ack_seq; /* Sequence number ACK'd */
544};
545
546#define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
547
548#include <net/tcp_ecn.h>
549
550/* Due to TSO, an SKB can be composed of multiple actual
551 * packets. To keep these tracked properly, we use this.
552 */
553static inline int tcp_skb_pcount(const struct sk_buff *skb)
554{
555 return skb_shinfo(skb)->tso_segs;
556}
557
558/* This is valid iff tcp_skb_pcount() > 1. */
559static inline int tcp_skb_mss(const struct sk_buff *skb)
560{
561 return skb_shinfo(skb)->tso_size;
562}
563
564static inline void tcp_dec_pcount_approx(__u32 *count,
565 const struct sk_buff *skb)
566{
567 if (*count) {
568 *count -= tcp_skb_pcount(skb);
569 if ((int)*count < 0)
570 *count = 0;
571 }
572}
573
574static inline void tcp_packets_out_inc(struct sock *sk,
575 struct tcp_sock *tp,
576 const struct sk_buff *skb)
577{
578 int orig = tp->packets_out;
579
580 tp->packets_out += tcp_skb_pcount(skb);
581 if (!orig)
3f421baa
ACM		 582 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
583 inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
1da177e4
LT		 584}
585
586static inline void tcp_packets_out_dec(struct tcp_sock *tp,
587 const struct sk_buff *skb)
588{
589 tp->packets_out -= tcp_skb_pcount(skb);
590}
591
317a76f9
SH		 592/* Events passed to congestion control interface */
593enum tcp_ca_event {
594 CA_EVENT_TX_START, /* first transmit when no packets in flight */
595 CA_EVENT_CWND_RESTART, /* congestion window restart */
596 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
597 CA_EVENT_FRTO, /* fast recovery timeout */
598 CA_EVENT_LOSS, /* loss timeout */
599 CA_EVENT_FAST_ACK, /* in sequence ack */
600 CA_EVENT_SLOW_ACK, /* other ack */
601};
602
603/*
604 * Interface for adding new TCP congestion control handlers
605 */
606#define TCP_CA_NAME_MAX 16
607struct tcp_congestion_ops {
608 struct list_head list;
609
610 /* initialize private data (optional) */
6687e988 611 void (*init)(struct sock *sk);
317a76f9 612 /* cleanup private data (optional) */
6687e988 613 void (*release)(struct sock *sk);
317a76f9
SH		 614
615 /* return slow start threshold (required) */
6687e988 616 u32 (*ssthresh)(struct sock *sk);
317a76f9 617 /* lower bound for congestion window (optional) */
6687e988 618 u32 (*min_cwnd)(struct sock *sk);
317a76f9 619 /* do new cwnd calculation (required) */
6687e988 620 void (*cong_avoid)(struct sock *sk, u32 ack,
317a76f9
SH		 621 u32 rtt, u32 in_flight, int good_ack);
622 /* round trip time sample per acked packet (optional) */
6687e988 623 void (*rtt_sample)(struct sock *sk, u32 usrtt);
317a76f9 624 /* call before changing ca_state (optional) */
6687e988 625 void (*set_state)(struct sock *sk, u8 new_state);
317a76f9 626 /* call when cwnd event occurs (optional) */
6687e988 627 void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
317a76f9 628 /* new value of cwnd after loss (optional) */
6687e988 629 u32 (*undo_cwnd)(struct sock *sk);
317a76f9 630 /* hook for packet ack accounting (optional) */
6687e988 631 void (*pkts_acked)(struct sock *sk, u32 num_acked);
73c1f4a0 632 /* get info for inet_diag (optional) */
6687e988 633 void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb);
317a76f9
SH		 634
635 char name[TCP_CA_NAME_MAX];
636 struct module *owner;
637};
638
639extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
640extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
641
6687e988
ACM		 642extern void tcp_init_congestion_control(struct sock *sk);
643extern void tcp_cleanup_congestion_control(struct sock *sk);
317a76f9
SH		 644extern int tcp_set_default_congestion_control(const char *name);
645extern void tcp_get_default_congestion_control(char *name);
6687e988 646extern int tcp_set_congestion_control(struct sock *sk, const char *name);
40efc6fa 647extern void tcp_slow_start(struct tcp_sock *tp);
317a76f9 648
5f8ef48d 649extern struct tcp_congestion_ops tcp_init_congestion_ops;
6687e988
ACM		 650extern u32 tcp_reno_ssthresh(struct sock *sk);
651extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack,
317a76f9 652 u32 rtt, u32 in_flight, int flag);
6687e988 653extern u32 tcp_reno_min_cwnd(struct sock *sk);
a8acfbac 654extern struct tcp_congestion_ops tcp_reno;
317a76f9 655
6687e988 656static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state)
317a76f9 657{
6687e988
ACM		 658 struct inet_connection_sock *icsk = inet_csk(sk);
659
660 if (icsk->icsk_ca_ops->set_state)
661 icsk->icsk_ca_ops->set_state(sk, ca_state);
662 icsk->icsk_ca_state = ca_state;
317a76f9
SH		 663}
664
6687e988 665static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event)
317a76f9 666{
6687e988
ACM		 667 const struct inet_connection_sock *icsk = inet_csk(sk);
668
669 if (icsk->icsk_ca_ops->cwnd_event)
670 icsk->icsk_ca_ops->cwnd_event(sk, event);
317a76f9
SH		 671}
672
1da177e4
LT		 673/* This determines how many packets are "in the network" to the best
674 * of our knowledge. In many cases it is conservative, but where
675 * detailed information is available from the receiver (via SACK
676 * blocks etc.) we can make more aggressive calculations.
677 *
678 * Use this for decisions involving congestion control, use just
679 * tp->packets_out to determine if the send queue is empty or not.
680 *
681 * Read this equation as:
682 *
683 * "Packets sent once on transmission queue" MINUS
684 * "Packets left network, but not honestly ACKed yet" PLUS
685 * "Packets fast retransmitted"
686 */
40efc6fa 687static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
1da177e4
LT		 688{
689 return (tp->packets_out - tp->left_out + tp->retrans_out);
690}
691
1da177e4
LT		 692/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
693 * The exception is rate halving phase, when cwnd is decreasing towards
694 * ssthresh.
695 */
6687e988 696static inline __u32 tcp_current_ssthresh(const struct sock *sk)
1da177e4 697{
6687e988
ACM		 698 const struct tcp_sock *tp = tcp_sk(sk);
699 if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery))
1da177e4
LT		 700 return tp->snd_ssthresh;
701 else
702 return max(tp->snd_ssthresh,
703 ((tp->snd_cwnd >> 1) +
704 (tp->snd_cwnd >> 2)));
705}
706
707static inline void tcp_sync_left_out(struct tcp_sock *tp)
708{
709 if (tp->rx_opt.sack_ok &&
710 (tp->sacked_out >= tp->packets_out - tp->lost_out))
711 tp->sacked_out = tp->packets_out - tp->lost_out;
712 tp->left_out = tp->sacked_out + tp->lost_out;
713}
714
40efc6fa 715extern void tcp_enter_cwr(struct sock *sk);
1da177e4
LT		 716extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst);
717
718/* Slow start with delack produces 3 packets of burst, so that
719 * it is safe "de facto".
720 */
721static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
722{
723 return 3;
724}
725
f4805ede
SH		 726/* RFC2861 Check whether we are limited by application or congestion window
727 * This is the inverse of cwnd check in tcp_tso_should_defer
728 */
729static inline int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight)
730{
731 const struct tcp_sock *tp = tcp_sk(sk);
732 u32 left;
733
734 if (in_flight >= tp->snd_cwnd)
735 return 1;
736
737 if (!(sk->sk_route_caps & NETIF_F_TSO))
738 return 0;
739
740 left = tp->snd_cwnd - in_flight;
741 if (sysctl_tcp_tso_win_divisor)
742 return left * sysctl_tcp_tso_win_divisor < tp->snd_cwnd;
743 else
744 return left <= tcp_max_burst(tp);
745}
746
40efc6fa
SH		 747static inline void tcp_minshall_update(struct tcp_sock *tp, int mss,
748 const struct sk_buff *skb)
1da177e4
LT		 749{
750 if (skb->len < mss)
751 tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
752}
753
40efc6fa 754static inline void tcp_check_probe_timer(struct sock *sk, struct tcp_sock *tp)
1da177e4 755{
463c84b9
ACM		 756 const struct inet_connection_sock *icsk = inet_csk(sk);
757 if (!tp->packets_out && !icsk->icsk_pending)
3f421baa
ACM		 758 inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
759 icsk->icsk_rto, TCP_RTO_MAX);
1da177e4
LT		 760}
761
40efc6fa
SH		 762static inline void tcp_push_pending_frames(struct sock *sk,
763 struct tcp_sock *tp)
1da177e4
LT		 764{
765 __tcp_push_pending_frames(sk, tp, tcp_current_mss(sk, 1), tp->nonagle);
766}
767
40efc6fa 768static inline void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq)
1da177e4
LT		 769{
770 tp->snd_wl1 = seq;
771}
772
40efc6fa 773static inline void tcp_update_wl(struct tcp_sock *tp, u32 ack, u32 seq)
1da177e4
LT		 774{
775 tp->snd_wl1 = seq;
776}
777
1da177e4
LT		 778/*
779 * Calculate(/check) TCP checksum
780 */
40efc6fa
SH		 781static inline u16 tcp_v4_check(struct tcphdr *th, int len,
782 unsigned long saddr, unsigned long daddr,
783 unsigned long base)
1da177e4
LT		 784{
785 return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base);
786}
787
40efc6fa 788static inline int __tcp_checksum_complete(struct sk_buff *skb)
1da177e4 789{
fb286bb2 790 return __skb_checksum_complete(skb);
1da177e4
LT		 791}
792
40efc6fa 793static inline int tcp_checksum_complete(struct sk_buff *skb)
1da177e4
LT		 794{
795 return skb->ip_summed != CHECKSUM_UNNECESSARY &&
796 __tcp_checksum_complete(skb);
797}
798
799/* Prequeue for VJ style copy to user, combined with checksumming. */
800
40efc6fa 801static inline void tcp_prequeue_init(struct tcp_sock *tp)
1da177e4
LT		 802{
803 tp->ucopy.task = NULL;
804 tp->ucopy.len = 0;
805 tp->ucopy.memory = 0;
806 skb_queue_head_init(&tp->ucopy.prequeue);
807}
808
809/* Packet is added to VJ-style prequeue for processing in process
810 * context, if a reader task is waiting. Apparently, this exciting
811 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
812 * failed somewhere. Latency? Burstiness? Well, at least now we will
813 * see, why it failed. 8)8) --ANK
814 *
815 * NOTE: is this not too big to inline?
816 */
40efc6fa 817static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb)
1da177e4
LT		 818{
819 struct tcp_sock *tp = tcp_sk(sk);
820
821 if (!sysctl_tcp_low_latency && tp->ucopy.task) {
822 __skb_queue_tail(&tp->ucopy.prequeue, skb);
823 tp->ucopy.memory += skb->truesize;
824 if (tp->ucopy.memory > sk->sk_rcvbuf) {
825 struct sk_buff *skb1;
826
827 BUG_ON(sock_owned_by_user(sk));
828
829 while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) {
830 sk->sk_backlog_rcv(sk, skb1);
831 NET_INC_STATS_BH(LINUX_MIB_TCPPREQUEUEDROPPED);
832 }
833
834 tp->ucopy.memory = 0;
835 } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
836 wake_up_interruptible(sk->sk_sleep);
463c84b9
ACM		 837 if (!inet_csk_ack_scheduled(sk))
838 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
3f421baa
ACM		 839 (3 * TCP_RTO_MIN) / 4,
840 TCP_RTO_MAX);
1da177e4
LT		 841 }
842 return 1;
843 }
844 return 0;
845}
846
847
848#undef STATE_TRACE
849
850#ifdef STATE_TRACE
851static const char *statename[]={
852 "Unused","Established","Syn Sent","Syn Recv",
853 "Fin Wait 1","Fin Wait 2","Time Wait", "Close",
854 "Close Wait","Last ACK","Listen","Closing"
855};
856#endif
857
40efc6fa 858static inline void tcp_set_state(struct sock *sk, int state)
1da177e4
LT		 859{
860 int oldstate = sk->sk_state;
861
862 switch (state) {
863 case TCP_ESTABLISHED:
864 if (oldstate != TCP_ESTABLISHED)
865 TCP_INC_STATS(TCP_MIB_CURRESTAB);
866 break;
867
868 case TCP_CLOSE:
869 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
870 TCP_INC_STATS(TCP_MIB_ESTABRESETS);
871
872 sk->sk_prot->unhash(sk);
463c84b9 873 if (inet_csk(sk)->icsk_bind_hash &&
1da177e4 874 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2d8c4ce5 875 inet_put_port(&tcp_hashinfo, sk);
1da177e4
LT		 876 /* fall through */
877 default:
878 if (oldstate==TCP_ESTABLISHED)
879 TCP_DEC_STATS(TCP_MIB_CURRESTAB);
880 }
881
882 /* Change state AFTER socket is unhashed to avoid closed
883 * socket sitting in hash tables.
884 */
885 sk->sk_state = state;
886
887#ifdef STATE_TRACE
888 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]);
889#endif
890}
891
40efc6fa 892static inline void tcp_done(struct sock *sk)
1da177e4
LT		 893{
894 tcp_set_state(sk, TCP_CLOSE);
895 tcp_clear_xmit_timers(sk);
896
897 sk->sk_shutdown = SHUTDOWN_MASK;
898
899 if (!sock_flag(sk, SOCK_DEAD))
900 sk->sk_state_change(sk);
901 else
0a5578cf 902 inet_csk_destroy_sock(sk);
1da177e4
LT		 903}
904
40efc6fa 905static inline void tcp_sack_reset(struct tcp_options_received *rx_opt)
1da177e4
LT		 906{
907 rx_opt->dsack = 0;
908 rx_opt->eff_sacks = 0;
909 rx_opt->num_sacks = 0;
910}
911
1da177e4
LT		 912/* Determine a window scaling and initial window to offer. */
913extern void tcp_select_initial_window(int __space, __u32 mss,
914 __u32 *rcv_wnd, __u32 *window_clamp,
915 int wscale_ok, __u8 *rcv_wscale);
916
917static inline int tcp_win_from_space(int space)
918{
919 return sysctl_tcp_adv_win_scale<=0 ?
920 (space>>(-sysctl_tcp_adv_win_scale)) :
921 space - (space>>sysctl_tcp_adv_win_scale);
922}
923
924/* Note: caller must be prepared to deal with negative returns */
925static inline int tcp_space(const struct sock *sk)
926{
927 return tcp_win_from_space(sk->sk_rcvbuf -
928 atomic_read(&sk->sk_rmem_alloc));
929}
930
931static inline int tcp_full_space(const struct sock *sk)
932{
933 return tcp_win_from_space(sk->sk_rcvbuf);
934}
935
40efc6fa
SH		 936static inline void tcp_openreq_init(struct request_sock *req,
937 struct tcp_options_received *rx_opt,
938 struct sk_buff *skb)
1da177e4 939{
2e6599cb
ACM		 940 struct inet_request_sock *ireq = inet_rsk(req);
941
1da177e4 942 req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */
2e6599cb 943 tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
1da177e4
LT		 944 req->mss = rx_opt->mss_clamp;
945 req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
2e6599cb
ACM		 946 ireq->tstamp_ok = rx_opt->tstamp_ok;
947 ireq->sack_ok = rx_opt->sack_ok;
948 ireq->snd_wscale = rx_opt->snd_wscale;
949 ireq->wscale_ok = rx_opt->wscale_ok;
950 ireq->acked = 0;
951 ireq->ecn_ok = 0;
952 ireq->rmt_port = skb->h.th->source;
1da177e4
LT		 953}
954
955extern void tcp_enter_memory_pressure(void);
956
1da177e4
LT		 957static inline int keepalive_intvl_when(const struct tcp_sock *tp)
958{
959 return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl;
960}
961
962static inline int keepalive_time_when(const struct tcp_sock *tp)
963{
964 return tp->keepalive_time ? : sysctl_tcp_keepalive_time;
965}
966
463c84b9 967static inline int tcp_fin_time(const struct sock *sk)
1da177e4 968{
463c84b9
ACM		 969 int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout;
970 const int rto = inet_csk(sk)->icsk_rto;
1da177e4 971
463c84b9
ACM		 972 if (fin_timeout < (rto << 2) - (rto >> 1))
973 fin_timeout = (rto << 2) - (rto >> 1);
1da177e4
LT		 974
975 return fin_timeout;
976}
977
978static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, int rst)
979{
980 if ((s32)(rx_opt->rcv_tsval - rx_opt->ts_recent) >= 0)
981 return 0;
982 if (xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)
983 return 0;
984
985 /* RST segments are not recommended to carry timestamp,
986 and, if they do, it is recommended to ignore PAWS because
987 "their cleanup function should take precedence over timestamps."
988 Certainly, it is mistake. It is necessary to understand the reasons
989 of this constraint to relax it: if peer reboots, clock may go
990 out-of-sync and half-open connections will not be reset.
991 Actually, the problem would be not existing if all
992 the implementations followed draft about maintaining clock
993 via reboots. Linux-2.2 DOES NOT!
994
995 However, we can relax time bounds for RST segments to MSL.
996 */
997 if (rst && xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
998 return 0;
999 return 1;
1000}
1001
1da177e4
LT		 1002#define TCP_CHECK_TIMER(sk) do { } while (0)
1003
1004static inline int tcp_use_frto(const struct sock *sk)
1005{
1006 const struct tcp_sock *tp = tcp_sk(sk);
1007
1008 /* F-RTO must be activated in sysctl and there must be some
1009 * unsent new data, and the advertised window should allow
1010 * sending it.
1011 */
1012 return (sysctl_tcp_frto && sk->sk_send_head &&
1013 !after(TCP_SKB_CB(sk->sk_send_head)->end_seq,
1014 tp->snd_una + tp->snd_wnd));
1015}
1016
1017static inline void tcp_mib_init(void)
1018{
1019 /* See RFC 2012 */
1020 TCP_ADD_STATS_USER(TCP_MIB_RTOALGORITHM, 1);
1021 TCP_ADD_STATS_USER(TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ);
1022 TCP_ADD_STATS_USER(TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ);
1023 TCP_ADD_STATS_USER(TCP_MIB_MAXCONN, -1);
1024}
1025
6a438bbe
SH		 1026/*from STCP */
1027static inline void clear_all_retrans_hints(struct tcp_sock *tp){
1028 tp->lost_skb_hint = NULL;
1029 tp->scoreboard_skb_hint = NULL;
1030 tp->retransmit_skb_hint = NULL;
1031 tp->forward_skb_hint = NULL;
1032 tp->fastpath_skb_hint = NULL;
1033}
1034
1da177e4
LT		 1035/* /proc */
1036enum tcp_seq_states {
1037 TCP_SEQ_STATE_LISTENING,
1038 TCP_SEQ_STATE_OPENREQ,
1039 TCP_SEQ_STATE_ESTABLISHED,
1040 TCP_SEQ_STATE_TIME_WAIT,
1041};
1042
1043struct tcp_seq_afinfo {
1044 struct module *owner;
1045 char *name;
1046 sa_family_t family;
1047 int (*seq_show) (struct seq_file *m, void *v);
1048 struct file_operations *seq_fops;
1049};
1050
1051struct tcp_iter_state {
1052 sa_family_t family;
1053 enum tcp_seq_states state;
1054 struct sock *syn_wait_sk;
1055 int bucket, sbucket, num, uid;
1056 struct seq_operations seq_ops;
1057};
1058
1059extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo);
1060extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo);
1061
20380731
ACM		 1062extern struct request_sock_ops tcp_request_sock_ops;
1063
1064extern int tcp_v4_destroy_sock(struct sock *sk);
1065
1066#ifdef CONFIG_PROC_FS
1067extern int tcp4_proc_init(void);
1068extern void tcp4_proc_exit(void);
1069#endif
1070
1071extern void tcp_v4_init(struct net_proto_family *ops);
1072extern void tcp_init(void);
1073
1da177e4 1074#endif /* _TCP_H */
kernel source for telekom puls (alcatel/mediatek)