projects / linux-2.6-block.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
[NET]: Make NETDEBUG pure printk wrappers
[linux-2.6-block.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>
3f421baa
ACM		 30
31#include <net/inet_connection_sock.h>
295ff7ed 32#include <net/inet_timewait_sock.h>
77d8bf9c 33#include <net/inet_hashtables.h>
1da177e4 34#include <net/checksum.h>
2e6599cb 35#include <net/request_sock.h>
1da177e4
LT		 36#include <net/sock.h>
37#include <net/snmp.h>
38#include <net/ip.h>
c752f073
ACM		 39#include <net/tcp_states.h>
40
1da177e4
LT		 41#include <linux/seq_file.h>
42
6e04e021 43extern struct inet_hashinfo tcp_hashinfo;
1da177e4 44
1da177e4 45extern atomic_t tcp_orphan_count;
1da177e4 46extern void tcp_time_wait(struct sock *sk, int state, int timeo);
1da177e4 47
1da177e4
LT		 48#define MAX_TCP_HEADER (128 + MAX_HEADER)
49
50/*
51 * Never offer a window over 32767 without using window scaling. Some
52 * poor stacks do signed 16bit maths!
53 */
54#define MAX_TCP_WINDOW 32767U
55
56/* Minimal accepted MSS. It is (60+60+8) - (20+20). */
57#define TCP_MIN_MSS 88U
58
59/* Minimal RCV_MSS. */
60#define TCP_MIN_RCVMSS 536U
61
62/* After receiving this amount of duplicate ACKs fast retransmit starts. */
63#define TCP_FASTRETRANS_THRESH 3
64
65/* Maximal reordering. */
66#define TCP_MAX_REORDERING 127
67
68/* Maximal number of ACKs sent quickly to accelerate slow-start. */
69#define TCP_MAX_QUICKACKS 16U
70
71/* urg_data states */
72#define TCP_URG_VALID 0x0100
73#define TCP_URG_NOTYET 0x0200
74#define TCP_URG_READ 0x0400
75
76#define TCP_RETR1 3 /*
77 * This is how many retries it does before it
78 * tries to figure out if the gateway is
79 * down. Minimal RFC value is 3; it corresponds
80 * to ~3sec-8min depending on RTO.
81 */
82
83#define TCP_RETR2 15 /*
84 * This should take at least
85 * 90 minutes to time out.
86 * RFC1122 says that the limit is 100 sec.
87 * 15 is ~13-30min depending on RTO.
88 */
89
90#define TCP_SYN_RETRIES 5 /* number of times to retry active opening a
91 * connection: ~180sec is RFC minumum */
92
93#define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a
94 * connection: ~180sec is RFC minumum */
95
96
97#define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned
98 * socket. 7 is ~50sec-16min.
99 */
100
101
102#define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT
103 * state, about 60 seconds */
104#define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN
105 /* BSD style FIN_WAIT2 deadlock breaker.
106 * It used to be 3min, new value is 60sec,
107 * to combine FIN-WAIT-2 timeout with
108 * TIME-WAIT timer.
109 */
110
111#define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */
112#if HZ >= 100
113#define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */
114#define TCP_ATO_MIN ((unsigned)(HZ/25))
115#else
116#define TCP_DELACK_MIN 4U
117#define TCP_ATO_MIN 4U
118#endif
119#define TCP_RTO_MAX ((unsigned)(120*HZ))
120#define TCP_RTO_MIN ((unsigned)(HZ/5))
121#define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */
122
123#define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
124 * for local resources.
125 */
126
127#define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */
128#define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */
129#define TCP_KEEPALIVE_INTVL (75*HZ)
130
131#define MAX_TCP_KEEPIDLE 32767
132#define MAX_TCP_KEEPINTVL 32767
133#define MAX_TCP_KEEPCNT 127
134#define MAX_TCP_SYNCNT 127
135
136#define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */
137#define TCP_SYNQ_HSIZE 512 /* Size of SYNACK hash table */
138
139#define TCP_PAWS_24DAYS (60 * 60 * 24 * 24)
140#define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated
141 * after this time. It should be equal
142 * (or greater than) TCP_TIMEWAIT_LEN
143 * to provide reliability equal to one
144 * provided by timewait state.
145 */
146#define TCP_PAWS_WINDOW 1 /* Replay window for per-host
147 * timestamps. It must be less than
148 * minimal timewait lifetime.
149 */
1da177e4
LT		 150/*
151 * TCP option
152 */
153
154#define TCPOPT_NOP 1 /* Padding */
155#define TCPOPT_EOL 0 /* End of options */
156#define TCPOPT_MSS 2 /* Segment size negotiating */
157#define TCPOPT_WINDOW 3 /* Window scaling */
158#define TCPOPT_SACK_PERM 4 /* SACK Permitted */
159#define TCPOPT_SACK 5 /* SACK Block */
160#define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
161
162/*
163 * TCP option lengths
164 */
165
166#define TCPOLEN_MSS 4
167#define TCPOLEN_WINDOW 3
168#define TCPOLEN_SACK_PERM 2
169#define TCPOLEN_TIMESTAMP 10
170
171/* But this is what stacks really send out. */
172#define TCPOLEN_TSTAMP_ALIGNED 12
173#define TCPOLEN_WSCALE_ALIGNED 4
174#define TCPOLEN_SACKPERM_ALIGNED 4
175#define TCPOLEN_SACK_BASE 2
176#define TCPOLEN_SACK_BASE_ALIGNED 4
177#define TCPOLEN_SACK_PERBLOCK 8
178
1da177e4
LT		 179/* Flags in tp->nonagle */
180#define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
181#define TCP_NAGLE_CORK 2 /* Socket is corked */
182#define TCP_NAGLE_PUSH 4 /* Cork is overriden for already queued data */
183
295ff7ed
ACM		 184extern struct inet_timewait_death_row tcp_death_row;
185
1da177e4 186/* sysctl variables for tcp */
1da177e4
LT		 187extern int sysctl_tcp_timestamps;
188extern int sysctl_tcp_window_scaling;
189extern int sysctl_tcp_sack;
190extern int sysctl_tcp_fin_timeout;
1da177e4
LT		 191extern int sysctl_tcp_keepalive_time;
192extern int sysctl_tcp_keepalive_probes;
193extern int sysctl_tcp_keepalive_intvl;
194extern int sysctl_tcp_syn_retries;
195extern int sysctl_tcp_synack_retries;
196extern int sysctl_tcp_retries1;
197extern int sysctl_tcp_retries2;
198extern int sysctl_tcp_orphan_retries;
199extern int sysctl_tcp_syncookies;
200extern int sysctl_tcp_retrans_collapse;
201extern int sysctl_tcp_stdurg;
202extern int sysctl_tcp_rfc1337;
203extern int sysctl_tcp_abort_on_overflow;
204extern int sysctl_tcp_max_orphans;
1da177e4
LT		 205extern int sysctl_tcp_fack;
206extern int sysctl_tcp_reordering;
207extern int sysctl_tcp_ecn;
208extern int sysctl_tcp_dsack;
209extern int sysctl_tcp_mem[3];
210extern int sysctl_tcp_wmem[3];
211extern int sysctl_tcp_rmem[3];
212extern int sysctl_tcp_app_win;
213extern int sysctl_tcp_adv_win_scale;
214extern int sysctl_tcp_tw_reuse;
215extern int sysctl_tcp_frto;
216extern int sysctl_tcp_low_latency;
1da177e4 217extern int sysctl_tcp_nometrics_save;
1da177e4
LT		 218extern int sysctl_tcp_moderate_rcvbuf;
219extern int sysctl_tcp_tso_win_divisor;
220
221extern atomic_t tcp_memory_allocated;
222extern atomic_t tcp_sockets_allocated;
223extern int tcp_memory_pressure;
224
1da177e4
LT		 225/*
226 * Pointers to address related TCP functions
227 * (i.e. things that depend on the address family)
228 */
229
230struct tcp_func {
231 int (*queue_xmit) (struct sk_buff *skb,
232 int ipfragok);
233
234 void (*send_check) (struct sock *sk,
235 struct tcphdr *th,
236 int len,
237 struct sk_buff *skb);
238
239 int (*rebuild_header) (struct sock *sk);
240
241 int (*conn_request) (struct sock *sk,
242 struct sk_buff *skb);
243
244 struct sock * (*syn_recv_sock) (struct sock *sk,
245 struct sk_buff *skb,
60236fdd 246 struct request_sock *req,
1da177e4
LT		 247 struct dst_entry *dst);
248
249 int (*remember_stamp) (struct sock *sk);
250
251 __u16 net_header_len;
252
253 int (*setsockopt) (struct sock *sk,
254 int level,
255 int optname,
256 char __user *optval,
257 int optlen);
258
259 int (*getsockopt) (struct sock *sk,
260 int level,
261 int optname,
262 char __user *optval,
263 int __user *optlen);
264
265
266 void (*addr2sockaddr) (struct sock *sk,
267 struct sockaddr *);
268
269 int sockaddr_len;
270};
271
272/*
273 * The next routines deal with comparing 32 bit unsigned ints
274 * and worry about wraparound (automatic with unsigned arithmetic).
275 */
276
277static inline int before(__u32 seq1, __u32 seq2)
278{
279 return (__s32)(seq1-seq2) < 0;
280}
281
282static inline int after(__u32 seq1, __u32 seq2)
283{
284 return (__s32)(seq2-seq1) < 0;
285}
286
287
288/* is s2<=s1<=s3 ? */
289static inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
290{
291 return seq3 - seq2 >= seq1 - seq2;
292}
293
294
295extern struct proto tcp_prot;
296
297DECLARE_SNMP_STAT(struct tcp_mib, tcp_statistics);
298#define TCP_INC_STATS(field) SNMP_INC_STATS(tcp_statistics, field)
299#define TCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(tcp_statistics, field)
300#define TCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(tcp_statistics, field)
301#define TCP_DEC_STATS(field) SNMP_DEC_STATS(tcp_statistics, field)
302#define TCP_ADD_STATS_BH(field, val) SNMP_ADD_STATS_BH(tcp_statistics, field, val)
303#define TCP_ADD_STATS_USER(field, val) SNMP_ADD_STATS_USER(tcp_statistics, field, val)
304
1da177e4
LT		 305extern void tcp_v4_err(struct sk_buff *skb, u32);
306
307extern void tcp_shutdown (struct sock *sk, int how);
308
309extern int tcp_v4_rcv(struct sk_buff *skb);
310
311extern int tcp_v4_remember_stamp(struct sock *sk);
312
8feaf0c0 313extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
1da177e4
LT		 314
315extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk,
316 struct msghdr *msg, size_t size);
317extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags);
318
319extern int tcp_ioctl(struct sock *sk,
320 int cmd,
321 unsigned long arg);
322
323extern int tcp_rcv_state_process(struct sock *sk,
324 struct sk_buff *skb,
325 struct tcphdr *th,
326 unsigned len);
327
328extern int tcp_rcv_established(struct sock *sk,
329 struct sk_buff *skb,
330 struct tcphdr *th,
331 unsigned len);
332
333extern void tcp_rcv_space_adjust(struct sock *sk);
334
463c84b9
ACM		 335static inline void tcp_dec_quickack_mode(struct sock *sk,
336 const unsigned int pkts)
1da177e4 337{
463c84b9 338 struct inet_connection_sock *icsk = inet_csk(sk);
fc6415bc 339
463c84b9
ACM		 340 if (icsk->icsk_ack.quick) {
341 if (pkts >= icsk->icsk_ack.quick) {
342 icsk->icsk_ack.quick = 0;
fc6415bc 343 /* Leaving quickack mode we deflate ATO. */
463c84b9 344 icsk->icsk_ack.ato = TCP_ATO_MIN;
fc6415bc 345 } else
463c84b9 346 icsk->icsk_ack.quick -= pkts;
1da177e4
LT		 347 }
348}
349
463c84b9 350extern void tcp_enter_quickack_mode(struct sock *sk);
1da177e4 351
1da177e4
LT		 352static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
353{
354 rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
355}
356
357enum tcp_tw_status
358{
359 TCP_TW_SUCCESS = 0,
360 TCP_TW_RST = 1,
361 TCP_TW_ACK = 2,
362 TCP_TW_SYN = 3
363};
364
365
8feaf0c0 366extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw,
1da177e4 367 struct sk_buff *skb,
8feaf0c0 368 const struct tcphdr *th);
1da177e4
LT		 369
370extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb,
60236fdd
ACM		 371 struct request_sock *req,
372 struct request_sock **prev);
1da177e4
LT		 373extern int tcp_child_process(struct sock *parent,
374 struct sock *child,
375 struct sk_buff *skb);
376extern void tcp_enter_frto(struct sock *sk);
377extern void tcp_enter_loss(struct sock *sk, int how);
378extern void tcp_clear_retrans(struct tcp_sock *tp);
379extern void tcp_update_metrics(struct sock *sk);
380
381extern void tcp_close(struct sock *sk,
382 long timeout);
1da177e4
LT		 383extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait);
384
385extern int tcp_getsockopt(struct sock *sk, int level,
386 int optname,
387 char __user *optval,
388 int __user *optlen);
389extern int tcp_setsockopt(struct sock *sk, int level,
390 int optname, char __user *optval,
391 int optlen);
392extern void tcp_set_keepalive(struct sock *sk, int val);
393extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
394 struct msghdr *msg,
395 size_t len, int nonblock,
396 int flags, int *addr_len);
397
1da177e4
LT		 398extern void tcp_parse_options(struct sk_buff *skb,
399 struct tcp_options_received *opt_rx,
400 int estab);
401
402/*
403 * TCP v4 functions exported for the inet6 API
404 */
405
1da177e4
LT		 406extern void tcp_v4_send_check(struct sock *sk,
407 struct tcphdr *th, int len,
408 struct sk_buff *skb);
409
410extern int tcp_v4_conn_request(struct sock *sk,
411 struct sk_buff *skb);
412
413extern struct sock * tcp_create_openreq_child(struct sock *sk,
60236fdd 414 struct request_sock *req,
1da177e4
LT		 415 struct sk_buff *skb);
416
417extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk,
418 struct sk_buff *skb,
60236fdd 419 struct request_sock *req,
1da177e4
LT		 420 struct dst_entry *dst);
421
422extern int tcp_v4_do_rcv(struct sock *sk,
423 struct sk_buff *skb);
424
425extern int tcp_v4_connect(struct sock *sk,
426 struct sockaddr *uaddr,
427 int addr_len);
428
429extern int tcp_connect(struct sock *sk);
430
431extern struct sk_buff * tcp_make_synack(struct sock *sk,
432 struct dst_entry *dst,
60236fdd 433 struct request_sock *req);
1da177e4
LT		 434
435extern int tcp_disconnect(struct sock *sk, int flags);
436
437extern void tcp_unhash(struct sock *sk);
438
439extern int tcp_v4_hash_connecting(struct sock *sk);
440
441
442/* From syncookies.c */
443extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
444 struct ip_options *opt);
445extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
446 __u16 *mss);
447
448/* tcp_output.c */
449
f6302d1d 450extern void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp,
a2e2a59c 451 unsigned int cur_mss, int nonagle);
f6302d1d 452extern int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp);
1da177e4
LT		 453extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);
454extern void tcp_xmit_retransmit_queue(struct sock *);
455extern void tcp_simple_retransmit(struct sock *);
456extern int tcp_trim_head(struct sock *, struct sk_buff *, u32);
457
458extern void tcp_send_probe0(struct sock *);
459extern void tcp_send_partial(struct sock *);
460extern int tcp_write_wakeup(struct sock *);
461extern void tcp_send_fin(struct sock *sk);
86a76caf
VF		 462extern void tcp_send_active_reset(struct sock *sk,
463 unsigned int __nocast priority);
1da177e4 464extern int tcp_send_synack(struct sock *);
c1b4a7e6 465extern void tcp_push_one(struct sock *, unsigned int mss_now);
1da177e4
LT		 466extern void tcp_send_ack(struct sock *sk);
467extern void tcp_send_delayed_ack(struct sock *sk);
468
a762a980
DM		 469/* tcp_input.c */
470extern void tcp_cwnd_application_limited(struct sock *sk);
471
1da177e4
LT		 472/* tcp_timer.c */
473extern void tcp_init_xmit_timers(struct sock *);
463c84b9
ACM		 474static inline void tcp_clear_xmit_timers(struct sock *sk)
475{
476 inet_csk_clear_xmit_timers(sk);
477}
1da177e4 478
1da177e4
LT		 479extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu);
480extern unsigned int tcp_current_mss(struct sock *sk, int large);
481
1da177e4
LT		 482/* tcp_diag.c */
483extern void tcp_get_info(struct sock *, struct tcp_info *);
484
485/* Read 'sendfile()'-style from a TCP socket */
486typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
487 unsigned int, size_t);
488extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
489 sk_read_actor_t recv_actor);
490
1da177e4
LT		 491/* Initialize RCV_MSS value.
492 * RCV_MSS is an our guess about MSS used by the peer.
493 * We haven't any direct information about the MSS.
494 * It's better to underestimate the RCV_MSS rather than overestimate.
495 * Overestimations make us ACKing less frequently than needed.
496 * Underestimations are more easy to detect and fix by tcp_measure_rcv_mss().
497 */
498
499static inline void tcp_initialize_rcv_mss(struct sock *sk)
500{
501 struct tcp_sock *tp = tcp_sk(sk);
c1b4a7e6 502 unsigned int hint = min_t(unsigned int, tp->advmss, tp->mss_cache);
1da177e4
LT		 503
504 hint = min(hint, tp->rcv_wnd/2);
505 hint = min(hint, TCP_MIN_RCVMSS);
506 hint = max(hint, TCP_MIN_MSS);
507
463c84b9 508 inet_csk(sk)->icsk_ack.rcv_mss = hint;
1da177e4
LT		 509}
510
511static __inline__ void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd)
512{
513 tp->pred_flags = htonl((tp->tcp_header_len << 26) |
514 ntohl(TCP_FLAG_ACK) |
515 snd_wnd);
516}
517
518static __inline__ void tcp_fast_path_on(struct tcp_sock *tp)
519{
520 __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale);
521}
522
523static inline void tcp_fast_path_check(struct sock *sk, struct tcp_sock *tp)
524{
b03efcfb 525 if (skb_queue_empty(&tp->out_of_order_queue) &&
1da177e4
LT		 526 tp->rcv_wnd &&
527 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
528 !tp->urg_data)
529 tcp_fast_path_on(tp);
530}
531
532/* Compute the actual receive window we are currently advertising.
533 * Rcv_nxt can be after the window if our peer push more data
534 * than the offered window.
535 */
536static __inline__ u32 tcp_receive_window(const struct tcp_sock *tp)
537{
538 s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt;
539
540 if (win < 0)
541 win = 0;
542 return (u32) win;
543}
544
545/* Choose a new window, without checks for shrinking, and without
546 * scaling applied to the result. The caller does these things
547 * if necessary. This is a "raw" window selection.
548 */
549extern u32 __tcp_select_window(struct sock *sk);
550
551/* TCP timestamps are only 32-bits, this causes a slight
552 * complication on 64-bit systems since we store a snapshot
553 * of jiffies in the buffer control blocks below. We decidely
554 * only use of the low 32-bits of jiffies and hide the ugly
555 * casts with the following macro.
556 */
557#define tcp_time_stamp ((__u32)(jiffies))
558
559/* This is what the send packet queueing engine uses to pass
560 * TCP per-packet control information to the transmission
561 * code. We also store the host-order sequence numbers in
562 * here too. This is 36 bytes on 32-bit architectures,
563 * 40 bytes on 64-bit machines, if this grows please adjust
564 * skbuff.h:skbuff->cb[xxx] size appropriately.
565 */
566struct tcp_skb_cb {
567 union {
568 struct inet_skb_parm h4;
569#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
570 struct inet6_skb_parm h6;
571#endif
572 } header; /* For incoming frames */
573 __u32 seq; /* Starting sequence number */
574 __u32 end_seq; /* SEQ + FIN + SYN + datalen */
575 __u32 when; /* used to compute rtt's */
576 __u8 flags; /* TCP header flags. */
577
578 /* NOTE: These must match up to the flags byte in a
579 * real TCP header.
580 */
581#define TCPCB_FLAG_FIN 0x01
582#define TCPCB_FLAG_SYN 0x02
583#define TCPCB_FLAG_RST 0x04
584#define TCPCB_FLAG_PSH 0x08
585#define TCPCB_FLAG_ACK 0x10
586#define TCPCB_FLAG_URG 0x20
587#define TCPCB_FLAG_ECE 0x40
588#define TCPCB_FLAG_CWR 0x80
589
590 __u8 sacked; /* State flags for SACK/FACK. */
591#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
592#define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
593#define TCPCB_LOST 0x04 /* SKB is lost */
594#define TCPCB_TAGBITS 0x07 /* All tag bits */
595
596#define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */
597#define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
598
599#define TCPCB_URG 0x20 /* Urgent pointer advenced here */
600
601#define TCPCB_AT_TAIL (TCPCB_URG)
602
603 __u16 urg_ptr; /* Valid w/URG flags is set. */
604 __u32 ack_seq; /* Sequence number ACK'd */
605};
606
607#define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
608
609#include <net/tcp_ecn.h>
610
611/* Due to TSO, an SKB can be composed of multiple actual
612 * packets. To keep these tracked properly, we use this.
613 */
614static inline int tcp_skb_pcount(const struct sk_buff *skb)
615{
616 return skb_shinfo(skb)->tso_segs;
617}
618
619/* This is valid iff tcp_skb_pcount() > 1. */
620static inline int tcp_skb_mss(const struct sk_buff *skb)
621{
622 return skb_shinfo(skb)->tso_size;
623}
624
625static inline void tcp_dec_pcount_approx(__u32 *count,
626 const struct sk_buff *skb)
627{
628 if (*count) {
629 *count -= tcp_skb_pcount(skb);
630 if ((int)*count < 0)
631 *count = 0;
632 }
633}
634
635static inline void tcp_packets_out_inc(struct sock *sk,
636 struct tcp_sock *tp,
637 const struct sk_buff *skb)
638{
639 int orig = tp->packets_out;
640
641 tp->packets_out += tcp_skb_pcount(skb);
642 if (!orig)
3f421baa
ACM		 643 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
644 inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
1da177e4
LT		 645}
646
647static inline void tcp_packets_out_dec(struct tcp_sock *tp,
648 const struct sk_buff *skb)
649{
650 tp->packets_out -= tcp_skb_pcount(skb);
651}
652
317a76f9
SH		 653/* Events passed to congestion control interface */
654enum tcp_ca_event {
655 CA_EVENT_TX_START, /* first transmit when no packets in flight */
656 CA_EVENT_CWND_RESTART, /* congestion window restart */
657 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
658 CA_EVENT_FRTO, /* fast recovery timeout */
659 CA_EVENT_LOSS, /* loss timeout */
660 CA_EVENT_FAST_ACK, /* in sequence ack */
661 CA_EVENT_SLOW_ACK, /* other ack */
662};
663
664/*
665 * Interface for adding new TCP congestion control handlers
666 */
667#define TCP_CA_NAME_MAX 16
668struct tcp_congestion_ops {
669 struct list_head list;
670
671 /* initialize private data (optional) */
672 void (*init)(struct tcp_sock *tp);
673 /* cleanup private data (optional) */
674 void (*release)(struct tcp_sock *tp);
675
676 /* return slow start threshold (required) */
677 u32 (*ssthresh)(struct tcp_sock *tp);
678 /* lower bound for congestion window (optional) */
679 u32 (*min_cwnd)(struct tcp_sock *tp);
680 /* do new cwnd calculation (required) */
681 void (*cong_avoid)(struct tcp_sock *tp, u32 ack,
682 u32 rtt, u32 in_flight, int good_ack);
683 /* round trip time sample per acked packet (optional) */
684 void (*rtt_sample)(struct tcp_sock *tp, u32 usrtt);
685 /* call before changing ca_state (optional) */
686 void (*set_state)(struct tcp_sock *tp, u8 new_state);
687 /* call when cwnd event occurs (optional) */
688 void (*cwnd_event)(struct tcp_sock *tp, enum tcp_ca_event ev);
689 /* new value of cwnd after loss (optional) */
690 u32 (*undo_cwnd)(struct tcp_sock *tp);
691 /* hook for packet ack accounting (optional) */
692 void (*pkts_acked)(struct tcp_sock *tp, u32 num_acked);
693 /* get info for tcp_diag (optional) */
694 void (*get_info)(struct tcp_sock *tp, u32 ext, struct sk_buff *skb);
695
696 char name[TCP_CA_NAME_MAX];
697 struct module *owner;
698};
699
700extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
701extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
702
703extern void tcp_init_congestion_control(struct tcp_sock *tp);
704extern void tcp_cleanup_congestion_control(struct tcp_sock *tp);
705extern int tcp_set_default_congestion_control(const char *name);
706extern void tcp_get_default_congestion_control(char *name);
5f8ef48d 707extern int tcp_set_congestion_control(struct tcp_sock *tp, const char *name);
317a76f9 708
5f8ef48d 709extern struct tcp_congestion_ops tcp_init_congestion_ops;
317a76f9
SH		 710extern u32 tcp_reno_ssthresh(struct tcp_sock *tp);
711extern void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack,
712 u32 rtt, u32 in_flight, int flag);
713extern u32 tcp_reno_min_cwnd(struct tcp_sock *tp);
a8acfbac 714extern struct tcp_congestion_ops tcp_reno;
317a76f9
SH		 715
716static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state)
717{
718 if (tp->ca_ops->set_state)
719 tp->ca_ops->set_state(tp, ca_state);
720 tp->ca_state = ca_state;
721}
722
723static inline void tcp_ca_event(struct tcp_sock *tp, enum tcp_ca_event event)
724{
725 if (tp->ca_ops->cwnd_event)
726 tp->ca_ops->cwnd_event(tp, event);
727}
728
1da177e4
LT		 729/* This determines how many packets are "in the network" to the best
730 * of our knowledge. In many cases it is conservative, but where
731 * detailed information is available from the receiver (via SACK
732 * blocks etc.) we can make more aggressive calculations.
733 *
734 * Use this for decisions involving congestion control, use just
735 * tp->packets_out to determine if the send queue is empty or not.
736 *
737 * Read this equation as:
738 *
739 * "Packets sent once on transmission queue" MINUS
740 * "Packets left network, but not honestly ACKed yet" PLUS
741 * "Packets fast retransmitted"
742 */
743static __inline__ unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
744{
745 return (tp->packets_out - tp->left_out + tp->retrans_out);
746}
747
1da177e4
LT		 748/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
749 * The exception is rate halving phase, when cwnd is decreasing towards
750 * ssthresh.
751 */
752static inline __u32 tcp_current_ssthresh(struct tcp_sock *tp)
753{
754 if ((1<<tp->ca_state)&(TCPF_CA_CWR|TCPF_CA_Recovery))
755 return tp->snd_ssthresh;
756 else
757 return max(tp->snd_ssthresh,
758 ((tp->snd_cwnd >> 1) +
759 (tp->snd_cwnd >> 2)));
760}
761
762static inline void tcp_sync_left_out(struct tcp_sock *tp)
763{
764 if (tp->rx_opt.sack_ok &&
765 (tp->sacked_out >= tp->packets_out - tp->lost_out))
766 tp->sacked_out = tp->packets_out - tp->lost_out;
767 tp->left_out = tp->sacked_out + tp->lost_out;
768}
769
d1b04c08 770/* Set slow start threshold and cwnd not falling to slow start */
1da177e4
LT		 771static inline void __tcp_enter_cwr(struct tcp_sock *tp)
772{
773 tp->undo_marker = 0;
317a76f9 774 tp->snd_ssthresh = tp->ca_ops->ssthresh(tp);
1da177e4
LT		 775 tp->snd_cwnd = min(tp->snd_cwnd,
776 tcp_packets_in_flight(tp) + 1U);
777 tp->snd_cwnd_cnt = 0;
778 tp->high_seq = tp->snd_nxt;
779 tp->snd_cwnd_stamp = tcp_time_stamp;
780 TCP_ECN_queue_cwr(tp);
781}
782
783static inline void tcp_enter_cwr(struct tcp_sock *tp)
784{
785 tp->prior_ssthresh = 0;
786 if (tp->ca_state < TCP_CA_CWR) {
787 __tcp_enter_cwr(tp);
788 tcp_set_ca_state(tp, TCP_CA_CWR);
789 }
790}
791
792extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst);
793
794/* Slow start with delack produces 3 packets of burst, so that
795 * it is safe "de facto".
796 */
797static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
798{
799 return 3;
800}
801
1da177e4
LT		 802static __inline__ void tcp_minshall_update(struct tcp_sock *tp, int mss,
803 const struct sk_buff *skb)
804{
805 if (skb->len < mss)
806 tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
807}
808
1da177e4
LT		 809static __inline__ void tcp_check_probe_timer(struct sock *sk, struct tcp_sock *tp)
810{
463c84b9
ACM		 811 const struct inet_connection_sock *icsk = inet_csk(sk);
812 if (!tp->packets_out && !icsk->icsk_pending)
3f421baa
ACM		 813 inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
814 icsk->icsk_rto, TCP_RTO_MAX);
1da177e4
LT		 815}
816
1da177e4
LT		 817static __inline__ void tcp_push_pending_frames(struct sock *sk,
818 struct tcp_sock *tp)
819{
820 __tcp_push_pending_frames(sk, tp, tcp_current_mss(sk, 1), tp->nonagle);
821}
822
1da177e4
LT		 823static __inline__ void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq)
824{
825 tp->snd_wl1 = seq;
826}
827
828static __inline__ void tcp_update_wl(struct tcp_sock *tp, u32 ack, u32 seq)
829{
830 tp->snd_wl1 = seq;
831}
832
1da177e4
LT		 833/*
834 * Calculate(/check) TCP checksum
835 */
836static __inline__ u16 tcp_v4_check(struct tcphdr *th, int len,
837 unsigned long saddr, unsigned long daddr,
838 unsigned long base)
839{
840 return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base);
841}
842
843static __inline__ int __tcp_checksum_complete(struct sk_buff *skb)
844{
845 return (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
846}
847
848static __inline__ int tcp_checksum_complete(struct sk_buff *skb)
849{
850 return skb->ip_summed != CHECKSUM_UNNECESSARY &&
851 __tcp_checksum_complete(skb);
852}
853
854/* Prequeue for VJ style copy to user, combined with checksumming. */
855
856static __inline__ void tcp_prequeue_init(struct tcp_sock *tp)
857{
858 tp->ucopy.task = NULL;
859 tp->ucopy.len = 0;
860 tp->ucopy.memory = 0;
861 skb_queue_head_init(&tp->ucopy.prequeue);
862}
863
864/* Packet is added to VJ-style prequeue for processing in process
865 * context, if a reader task is waiting. Apparently, this exciting
866 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
867 * failed somewhere. Latency? Burstiness? Well, at least now we will
868 * see, why it failed. 8)8) --ANK
869 *
870 * NOTE: is this not too big to inline?
871 */
872static __inline__ int tcp_prequeue(struct sock *sk, struct sk_buff *skb)
873{
874 struct tcp_sock *tp = tcp_sk(sk);
875
876 if (!sysctl_tcp_low_latency && tp->ucopy.task) {
877 __skb_queue_tail(&tp->ucopy.prequeue, skb);
878 tp->ucopy.memory += skb->truesize;
879 if (tp->ucopy.memory > sk->sk_rcvbuf) {
880 struct sk_buff *skb1;
881
882 BUG_ON(sock_owned_by_user(sk));
883
884 while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) {
885 sk->sk_backlog_rcv(sk, skb1);
886 NET_INC_STATS_BH(LINUX_MIB_TCPPREQUEUEDROPPED);
887 }
888
889 tp->ucopy.memory = 0;
890 } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
891 wake_up_interruptible(sk->sk_sleep);
463c84b9
ACM		 892 if (!inet_csk_ack_scheduled(sk))
893 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
3f421baa
ACM		 894 (3 * TCP_RTO_MIN) / 4,
895 TCP_RTO_MAX);
1da177e4
LT		 896 }
897 return 1;
898 }
899 return 0;
900}
901
902
903#undef STATE_TRACE
904
905#ifdef STATE_TRACE
906static const char *statename[]={
907 "Unused","Established","Syn Sent","Syn Recv",
908 "Fin Wait 1","Fin Wait 2","Time Wait", "Close",
909 "Close Wait","Last ACK","Listen","Closing"
910};
911#endif
912
913static __inline__ void tcp_set_state(struct sock *sk, int state)
914{
915 int oldstate = sk->sk_state;
916
917 switch (state) {
918 case TCP_ESTABLISHED:
919 if (oldstate != TCP_ESTABLISHED)
920 TCP_INC_STATS(TCP_MIB_CURRESTAB);
921 break;
922
923 case TCP_CLOSE:
924 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
925 TCP_INC_STATS(TCP_MIB_ESTABRESETS);
926
927 sk->sk_prot->unhash(sk);
463c84b9 928 if (inet_csk(sk)->icsk_bind_hash &&
1da177e4 929 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2d8c4ce5 930 inet_put_port(&tcp_hashinfo, sk);
1da177e4
LT		 931 /* fall through */
932 default:
933 if (oldstate==TCP_ESTABLISHED)
934 TCP_DEC_STATS(TCP_MIB_CURRESTAB);
935 }
936
937 /* Change state AFTER socket is unhashed to avoid closed
938 * socket sitting in hash tables.
939 */
940 sk->sk_state = state;
941
942#ifdef STATE_TRACE
943 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]);
944#endif
945}
946
947static __inline__ void tcp_done(struct sock *sk)
948{
949 tcp_set_state(sk, TCP_CLOSE);
950 tcp_clear_xmit_timers(sk);
951
952 sk->sk_shutdown = SHUTDOWN_MASK;
953
954 if (!sock_flag(sk, SOCK_DEAD))
955 sk->sk_state_change(sk);
956 else
0a5578cf 957 inet_csk_destroy_sock(sk);
1da177e4
LT		 958}
959
960static __inline__ void tcp_sack_reset(struct tcp_options_received *rx_opt)
961{
962 rx_opt->dsack = 0;
963 rx_opt->eff_sacks = 0;
964 rx_opt->num_sacks = 0;
965}
966
967static __inline__ void tcp_build_and_update_options(__u32 *ptr, struct tcp_sock *tp, __u32 tstamp)
968{
969 if (tp->rx_opt.tstamp_ok) {
970 *ptr++ = __constant_htonl((TCPOPT_NOP << 24) |
971 (TCPOPT_NOP << 16) |
972 (TCPOPT_TIMESTAMP << 8) |
973 TCPOLEN_TIMESTAMP);
974 *ptr++ = htonl(tstamp);
975 *ptr++ = htonl(tp->rx_opt.ts_recent);
976 }
977 if (tp->rx_opt.eff_sacks) {
978 struct tcp_sack_block *sp = tp->rx_opt.dsack ? tp->duplicate_sack : tp->selective_acks;
979 int this_sack;
980
981 *ptr++ = __constant_htonl((TCPOPT_NOP << 24) |
982 (TCPOPT_NOP << 16) |
983 (TCPOPT_SACK << 8) |
984 (TCPOLEN_SACK_BASE +
985 (tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK)));
986 for(this_sack = 0; this_sack < tp->rx_opt.eff_sacks; this_sack++) {
987 *ptr++ = htonl(sp[this_sack].start_seq);
988 *ptr++ = htonl(sp[this_sack].end_seq);
989 }
990 if (tp->rx_opt.dsack) {
991 tp->rx_opt.dsack = 0;
992 tp->rx_opt.eff_sacks--;
993 }
994 }
995}
996
997/* Construct a tcp options header for a SYN or SYN_ACK packet.
998 * If this is every changed make sure to change the definition of
999 * MAX_SYN_SIZE to match the new maximum number of options that you
1000 * can generate.
1001 */
1002static inline void tcp_syn_build_options(__u32 *ptr, int mss, int ts, int sack,
1003 int offer_wscale, int wscale, __u32 tstamp, __u32 ts_recent)
1004{
1005 /* We always get an MSS option.
1006 * The option bytes which will be seen in normal data
1007 * packets should timestamps be used, must be in the MSS
1008 * advertised. But we subtract them from tp->mss_cache so
1009 * that calculations in tcp_sendmsg are simpler etc.
1010 * So account for this fact here if necessary. If we
1011 * don't do this correctly, as a receiver we won't
1012 * recognize data packets as being full sized when we
1013 * should, and thus we won't abide by the delayed ACK
1014 * rules correctly.
1015 * SACKs don't matter, we never delay an ACK when we
1016 * have any of those going out.
1017 */
1018 *ptr++ = htonl((TCPOPT_MSS << 24) | (TCPOLEN_MSS << 16) | mss);
1019 if (ts) {
1020 if(sack)
1021 *ptr++ = __constant_htonl((TCPOPT_SACK_PERM << 24) | (TCPOLEN_SACK_PERM << 16) |
1022 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1023 else
1024 *ptr++ = __constant_htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1025 (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
1026 *ptr++ = htonl(tstamp); /* TSVAL */
1027 *ptr++ = htonl(ts_recent); /* TSECR */
1028 } else if(sack)
1029 *ptr++ = __constant_htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
1030 (TCPOPT_SACK_PERM << 8) | TCPOLEN_SACK_PERM);
1031 if (offer_wscale)
1032 *ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_WINDOW << 16) | (TCPOLEN_WINDOW << 8) | (wscale));
1033}
1034
1035/* Determine a window scaling and initial window to offer. */
1036extern void tcp_select_initial_window(int __space, __u32 mss,
1037 __u32 *rcv_wnd, __u32 *window_clamp,
1038 int wscale_ok, __u8 *rcv_wscale);
1039
1040static inline int tcp_win_from_space(int space)
1041{
1042 return sysctl_tcp_adv_win_scale<=0 ?
1043 (space>>(-sysctl_tcp_adv_win_scale)) :
1044 space - (space>>sysctl_tcp_adv_win_scale);
1045}
1046
1047/* Note: caller must be prepared to deal with negative returns */
1048static inline int tcp_space(const struct sock *sk)
1049{
1050 return tcp_win_from_space(sk->sk_rcvbuf -
1051 atomic_read(&sk->sk_rmem_alloc));
1052}
1053
1054static inline int tcp_full_space(const struct sock *sk)
1055{
1056 return tcp_win_from_space(sk->sk_rcvbuf);
1057}
1058
60236fdd 1059static __inline__ void tcp_openreq_init(struct request_sock *req,
1da177e4
LT		 1060 struct tcp_options_received *rx_opt,
1061 struct sk_buff *skb)
1062{
2e6599cb
ACM		 1063 struct inet_request_sock *ireq = inet_rsk(req);
1064
1da177e4 1065 req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */
2e6599cb 1066 tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
1da177e4
LT		 1067 req->mss = rx_opt->mss_clamp;
1068 req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
2e6599cb
ACM		 1069 ireq->tstamp_ok = rx_opt->tstamp_ok;
1070 ireq->sack_ok = rx_opt->sack_ok;
1071 ireq->snd_wscale = rx_opt->snd_wscale;
1072 ireq->wscale_ok = rx_opt->wscale_ok;
1073 ireq->acked = 0;
1074 ireq->ecn_ok = 0;
1075 ireq->rmt_port = skb->h.th->source;
1da177e4
LT		 1076}
1077
1078extern void tcp_enter_memory_pressure(void);
1079
1da177e4
LT		 1080static inline int keepalive_intvl_when(const struct tcp_sock *tp)
1081{
1082 return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl;
1083}
1084
1085static inline int keepalive_time_when(const struct tcp_sock *tp)
1086{
1087 return tp->keepalive_time ? : sysctl_tcp_keepalive_time;
1088}
1089
463c84b9 1090static inline int tcp_fin_time(const struct sock *sk)
1da177e4 1091{
463c84b9
ACM		 1092 int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout;
1093 const int rto = inet_csk(sk)->icsk_rto;
1da177e4 1094
463c84b9
ACM		 1095 if (fin_timeout < (rto << 2) - (rto >> 1))
1096 fin_timeout = (rto << 2) - (rto >> 1);
1da177e4
LT		 1097
1098 return fin_timeout;
1099}
1100
1101static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, int rst)
1102{
1103 if ((s32)(rx_opt->rcv_tsval - rx_opt->ts_recent) >= 0)
1104 return 0;
1105 if (xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)
1106 return 0;
1107
1108 /* RST segments are not recommended to carry timestamp,
1109 and, if they do, it is recommended to ignore PAWS because
1110 "their cleanup function should take precedence over timestamps."
1111 Certainly, it is mistake. It is necessary to understand the reasons
1112 of this constraint to relax it: if peer reboots, clock may go
1113 out-of-sync and half-open connections will not be reset.
1114 Actually, the problem would be not existing if all
1115 the implementations followed draft about maintaining clock
1116 via reboots. Linux-2.2 DOES NOT!
1117
1118 However, we can relax time bounds for RST segments to MSL.
1119 */
1120 if (rst && xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
1121 return 0;
1122 return 1;
1123}
1124
1da177e4
LT		 1125#define TCP_CHECK_TIMER(sk) do { } while (0)
1126
1127static inline int tcp_use_frto(const struct sock *sk)
1128{
1129 const struct tcp_sock *tp = tcp_sk(sk);
1130
1131 /* F-RTO must be activated in sysctl and there must be some
1132 * unsent new data, and the advertised window should allow
1133 * sending it.
1134 */
1135 return (sysctl_tcp_frto && sk->sk_send_head &&
1136 !after(TCP_SKB_CB(sk->sk_send_head)->end_seq,
1137 tp->snd_una + tp->snd_wnd));
1138}
1139
1140static inline void tcp_mib_init(void)
1141{
1142 /* See RFC 2012 */
1143 TCP_ADD_STATS_USER(TCP_MIB_RTOALGORITHM, 1);
1144 TCP_ADD_STATS_USER(TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ);
1145 TCP_ADD_STATS_USER(TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ);
1146 TCP_ADD_STATS_USER(TCP_MIB_MAXCONN, -1);
1147}
1148
1149/* /proc */
1150enum tcp_seq_states {
1151 TCP_SEQ_STATE_LISTENING,
1152 TCP_SEQ_STATE_OPENREQ,
1153 TCP_SEQ_STATE_ESTABLISHED,
1154 TCP_SEQ_STATE_TIME_WAIT,
1155};
1156
1157struct tcp_seq_afinfo {
1158 struct module *owner;
1159 char *name;
1160 sa_family_t family;
1161 int (*seq_show) (struct seq_file *m, void *v);
1162 struct file_operations *seq_fops;
1163};
1164
1165struct tcp_iter_state {
1166 sa_family_t family;
1167 enum tcp_seq_states state;
1168 struct sock *syn_wait_sk;
1169 int bucket, sbucket, num, uid;
1170 struct seq_operations seq_ops;
1171};
1172
1173extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo);
1174extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo);
1175
1da177e4 1176#endif /* _TCP_H */
Linux 6.x block layer and io_uring tree(s)