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[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / net / tcp.h
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 *
10 * Authors: Ross Biro
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
24 #include <linux/list.h>
25 #include <linux/tcp.h>
26 #include <linux/slab.h>
27 #include <linux/cache.h>
28 #include <linux/percpu.h>
29 #include <linux/skbuff.h>
30 #include <linux/dmaengine.h>
31 #include <linux/crypto.h>
32
33 #include <net/inet_connection_sock.h>
34 #include <net/inet_timewait_sock.h>
35 #include <net/inet_hashtables.h>
36 #include <net/checksum.h>
37 #include <net/request_sock.h>
38 #include <net/sock.h>
39 #include <net/snmp.h>
40 #include <net/ip.h>
41 #include <net/tcp_states.h>
42
43 #include <linux/seq_file.h>
44
45 extern struct inet_hashinfo tcp_hashinfo;
46
47 extern atomic_t tcp_orphan_count;
48 extern void tcp_time_wait(struct sock *sk, int state, int timeo);
49
50 #define MAX_TCP_HEADER (128 + MAX_HEADER)
51
52 /*
53 * Never offer a window over 32767 without using window scaling. Some
54 * poor stacks do signed 16bit maths!
55 */
56 #define MAX_TCP_WINDOW 32767U
57
58 /* Minimal accepted MSS. It is (60+60+8) - (20+20). */
59 #define TCP_MIN_MSS 88U
60
61 /* Minimal RCV_MSS. */
62 #define TCP_MIN_RCVMSS 536U
63
64 /* The least MTU to use for probing */
65 #define TCP_BASE_MSS 512
66
67 /* After receiving this amount of duplicate ACKs fast retransmit starts. */
68 #define TCP_FASTRETRANS_THRESH 3
69
70 /* Maximal reordering. */
71 #define TCP_MAX_REORDERING 127
72
73 /* Maximal number of ACKs sent quickly to accelerate slow-start. */
74 #define TCP_MAX_QUICKACKS 16U
75
76 /* urg_data states */
77 #define TCP_URG_VALID 0x0100
78 #define TCP_URG_NOTYET 0x0200
79 #define TCP_URG_READ 0x0400
80
81 #define TCP_RETR1 3 /*
82 * This is how many retries it does before it
83 * tries to figure out if the gateway is
84 * down. Minimal RFC value is 3; it corresponds
85 * to ~3sec-8min depending on RTO.
86 */
87
88 #define TCP_RETR2 15 /*
89 * This should take at least
90 * 90 minutes to time out.
91 * RFC1122 says that the limit is 100 sec.
92 * 15 is ~13-30min depending on RTO.
93 */
94
95 #define TCP_SYN_RETRIES 5 /* number of times to retry active opening a
96 * connection: ~180sec is RFC minimum */
97
98 #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a
99 * connection: ~180sec is RFC minimum */
100
101
102 #define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned
103 * socket. 7 is ~50sec-16min.
104 */
105
106
107 #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT
108 * state, about 60 seconds */
109 #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN
110 /* BSD style FIN_WAIT2 deadlock breaker.
111 * It used to be 3min, new value is 60sec,
112 * to combine FIN-WAIT-2 timeout with
113 * TIME-WAIT timer.
114 */
115
116 #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */
117 #if HZ >= 100
118 #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */
119 #define TCP_ATO_MIN ((unsigned)(HZ/25))
120 #else
121 #define TCP_DELACK_MIN 4U
122 #define TCP_ATO_MIN 4U
123 #endif
124 #define TCP_RTO_MAX ((unsigned)(120*HZ))
125 #define TCP_RTO_MIN ((unsigned)(HZ/5))
126 #define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */
127
128 #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
129 * for local resources.
130 */
131
132 #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */
133 #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */
134 #define TCP_KEEPALIVE_INTVL (75*HZ)
135
136 #define MAX_TCP_KEEPIDLE 32767
137 #define MAX_TCP_KEEPINTVL 32767
138 #define MAX_TCP_KEEPCNT 127
139 #define MAX_TCP_SYNCNT 127
140
141 #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */
142
143 #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24)
144 #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated
145 * after this time. It should be equal
146 * (or greater than) TCP_TIMEWAIT_LEN
147 * to provide reliability equal to one
148 * provided by timewait state.
149 */
150 #define TCP_PAWS_WINDOW 1 /* Replay window for per-host
151 * timestamps. It must be less than
152 * minimal timewait lifetime.
153 */
154 /*
155 * TCP option
156 */
157
158 #define TCPOPT_NOP 1 /* Padding */
159 #define TCPOPT_EOL 0 /* End of options */
160 #define TCPOPT_MSS 2 /* Segment size negotiating */
161 #define TCPOPT_WINDOW 3 /* Window scaling */
162 #define TCPOPT_SACK_PERM 4 /* SACK Permitted */
163 #define TCPOPT_SACK 5 /* SACK Block */
164 #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
165 #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */
166
167 /*
168 * TCP option lengths
169 */
170
171 #define TCPOLEN_MSS 4
172 #define TCPOLEN_WINDOW 3
173 #define TCPOLEN_SACK_PERM 2
174 #define TCPOLEN_TIMESTAMP 10
175 #define TCPOLEN_MD5SIG 18
176
177 /* But this is what stacks really send out. */
178 #define TCPOLEN_TSTAMP_ALIGNED 12
179 #define TCPOLEN_WSCALE_ALIGNED 4
180 #define TCPOLEN_SACKPERM_ALIGNED 4
181 #define TCPOLEN_SACK_BASE 2
182 #define TCPOLEN_SACK_BASE_ALIGNED 4
183 #define TCPOLEN_SACK_PERBLOCK 8
184 #define TCPOLEN_MD5SIG_ALIGNED 20
185
186 /* Flags in tp->nonagle */
187 #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
188 #define TCP_NAGLE_CORK 2 /* Socket is corked */
189 #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */
190
191 extern struct inet_timewait_death_row tcp_death_row;
192
193 /* sysctl variables for tcp */
194 extern int sysctl_tcp_timestamps;
195 extern int sysctl_tcp_window_scaling;
196 extern int sysctl_tcp_sack;
197 extern int sysctl_tcp_fin_timeout;
198 extern int sysctl_tcp_keepalive_time;
199 extern int sysctl_tcp_keepalive_probes;
200 extern int sysctl_tcp_keepalive_intvl;
201 extern int sysctl_tcp_syn_retries;
202 extern int sysctl_tcp_synack_retries;
203 extern int sysctl_tcp_retries1;
204 extern int sysctl_tcp_retries2;
205 extern int sysctl_tcp_orphan_retries;
206 extern int sysctl_tcp_syncookies;
207 extern int sysctl_tcp_retrans_collapse;
208 extern int sysctl_tcp_stdurg;
209 extern int sysctl_tcp_rfc1337;
210 extern int sysctl_tcp_abort_on_overflow;
211 extern int sysctl_tcp_max_orphans;
212 extern int sysctl_tcp_fack;
213 extern int sysctl_tcp_reordering;
214 extern int sysctl_tcp_ecn;
215 extern int sysctl_tcp_dsack;
216 extern int sysctl_tcp_mem[3];
217 extern int sysctl_tcp_wmem[3];
218 extern int sysctl_tcp_rmem[3];
219 extern int sysctl_tcp_app_win;
220 extern int sysctl_tcp_adv_win_scale;
221 extern int sysctl_tcp_tw_reuse;
222 extern int sysctl_tcp_frto;
223 extern int sysctl_tcp_low_latency;
224 extern int sysctl_tcp_dma_copybreak;
225 extern int sysctl_tcp_nometrics_save;
226 extern int sysctl_tcp_moderate_rcvbuf;
227 extern int sysctl_tcp_tso_win_divisor;
228 extern int sysctl_tcp_abc;
229 extern int sysctl_tcp_mtu_probing;
230 extern int sysctl_tcp_base_mss;
231 extern int sysctl_tcp_workaround_signed_windows;
232 extern int sysctl_tcp_slow_start_after_idle;
233
234 extern atomic_t tcp_memory_allocated;
235 extern atomic_t tcp_sockets_allocated;
236 extern int tcp_memory_pressure;
237
238 /*
239 * The next routines deal with comparing 32 bit unsigned ints
240 * and worry about wraparound (automatic with unsigned arithmetic).
241 */
242
243 static inline int before(__u32 seq1, __u32 seq2)
244 {
245 return (__s32)(seq1-seq2) < 0;
246 }
247 #define after(seq2, seq1) before(seq1, seq2)
248
249 /* is s2<=s1<=s3 ? */
250 static inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
251 {
252 return seq3 - seq2 >= seq1 - seq2;
253 }
254
255
256 extern struct proto tcp_prot;
257
258 DECLARE_SNMP_STAT(struct tcp_mib, tcp_statistics);
259 #define TCP_INC_STATS(field) SNMP_INC_STATS(tcp_statistics, field)
260 #define TCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(tcp_statistics, field)
261 #define TCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(tcp_statistics, field)
262 #define TCP_DEC_STATS(field) SNMP_DEC_STATS(tcp_statistics, field)
263 #define TCP_ADD_STATS_BH(field, val) SNMP_ADD_STATS_BH(tcp_statistics, field, val)
264 #define TCP_ADD_STATS_USER(field, val) SNMP_ADD_STATS_USER(tcp_statistics, field, val)
265
266 extern void tcp_v4_err(struct sk_buff *skb, u32);
267
268 extern void tcp_shutdown (struct sock *sk, int how);
269
270 extern int tcp_v4_rcv(struct sk_buff *skb);
271
272 extern int tcp_v4_remember_stamp(struct sock *sk);
273
274 extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
275
276 extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk,
277 struct msghdr *msg, size_t size);
278 extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags);
279
280 extern int tcp_ioctl(struct sock *sk,
281 int cmd,
282 unsigned long arg);
283
284 extern int tcp_rcv_state_process(struct sock *sk,
285 struct sk_buff *skb,
286 struct tcphdr *th,
287 unsigned len);
288
289 extern int tcp_rcv_established(struct sock *sk,
290 struct sk_buff *skb,
291 struct tcphdr *th,
292 unsigned len);
293
294 extern void tcp_rcv_space_adjust(struct sock *sk);
295
296 extern void tcp_cleanup_rbuf(struct sock *sk, int copied);
297
298 extern int tcp_twsk_unique(struct sock *sk,
299 struct sock *sktw, void *twp);
300
301 extern void tcp_twsk_destructor(struct sock *sk);
302
303 static inline void tcp_dec_quickack_mode(struct sock *sk,
304 const unsigned int pkts)
305 {
306 struct inet_connection_sock *icsk = inet_csk(sk);
307
308 if (icsk->icsk_ack.quick) {
309 if (pkts >= icsk->icsk_ack.quick) {
310 icsk->icsk_ack.quick = 0;
311 /* Leaving quickack mode we deflate ATO. */
312 icsk->icsk_ack.ato = TCP_ATO_MIN;
313 } else
314 icsk->icsk_ack.quick -= pkts;
315 }
316 }
317
318 extern void tcp_enter_quickack_mode(struct sock *sk);
319
320 static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
321 {
322 rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
323 }
324
325 enum tcp_tw_status
326 {
327 TCP_TW_SUCCESS = 0,
328 TCP_TW_RST = 1,
329 TCP_TW_ACK = 2,
330 TCP_TW_SYN = 3
331 };
332
333
334 extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw,
335 struct sk_buff *skb,
336 const struct tcphdr *th);
337
338 extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb,
339 struct request_sock *req,
340 struct request_sock **prev);
341 extern int tcp_child_process(struct sock *parent,
342 struct sock *child,
343 struct sk_buff *skb);
344 extern void tcp_enter_frto(struct sock *sk);
345 extern void tcp_enter_loss(struct sock *sk, int how);
346 extern void tcp_clear_retrans(struct tcp_sock *tp);
347 extern void tcp_update_metrics(struct sock *sk);
348
349 extern void tcp_close(struct sock *sk,
350 long timeout);
351 extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait);
352
353 extern int tcp_getsockopt(struct sock *sk, int level,
354 int optname,
355 char __user *optval,
356 int __user *optlen);
357 extern int tcp_setsockopt(struct sock *sk, int level,
358 int optname, char __user *optval,
359 int optlen);
360 extern int compat_tcp_getsockopt(struct sock *sk,
361 int level, int optname,
362 char __user *optval, int __user *optlen);
363 extern int compat_tcp_setsockopt(struct sock *sk,
364 int level, int optname,
365 char __user *optval, int optlen);
366 extern void tcp_set_keepalive(struct sock *sk, int val);
367 extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
368 struct msghdr *msg,
369 size_t len, int nonblock,
370 int flags, int *addr_len);
371
372 extern void tcp_parse_options(struct sk_buff *skb,
373 struct tcp_options_received *opt_rx,
374 int estab);
375
376 /*
377 * TCP v4 functions exported for the inet6 API
378 */
379
380 extern void tcp_v4_send_check(struct sock *sk, int len,
381 struct sk_buff *skb);
382
383 extern int tcp_v4_conn_request(struct sock *sk,
384 struct sk_buff *skb);
385
386 extern struct sock * tcp_create_openreq_child(struct sock *sk,
387 struct request_sock *req,
388 struct sk_buff *skb);
389
390 extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk,
391 struct sk_buff *skb,
392 struct request_sock *req,
393 struct dst_entry *dst);
394
395 extern int tcp_v4_do_rcv(struct sock *sk,
396 struct sk_buff *skb);
397
398 extern int tcp_v4_connect(struct sock *sk,
399 struct sockaddr *uaddr,
400 int addr_len);
401
402 extern int tcp_connect(struct sock *sk);
403
404 extern struct sk_buff * tcp_make_synack(struct sock *sk,
405 struct dst_entry *dst,
406 struct request_sock *req);
407
408 extern int tcp_disconnect(struct sock *sk, int flags);
409
410 extern void tcp_unhash(struct sock *sk);
411
412 /* From syncookies.c */
413 extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
414 struct ip_options *opt);
415 extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
416 __u16 *mss);
417
418 /* tcp_output.c */
419
420 extern void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp,
421 unsigned int cur_mss, int nonagle);
422 extern int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp);
423 extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);
424 extern void tcp_xmit_retransmit_queue(struct sock *);
425 extern void tcp_simple_retransmit(struct sock *);
426 extern int tcp_trim_head(struct sock *, struct sk_buff *, u32);
427 extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int);
428
429 extern void tcp_send_probe0(struct sock *);
430 extern void tcp_send_partial(struct sock *);
431 extern int tcp_write_wakeup(struct sock *);
432 extern void tcp_send_fin(struct sock *sk);
433 extern void tcp_send_active_reset(struct sock *sk, gfp_t priority);
434 extern int tcp_send_synack(struct sock *);
435 extern void tcp_push_one(struct sock *, unsigned int mss_now);
436 extern void tcp_send_ack(struct sock *sk);
437 extern void tcp_send_delayed_ack(struct sock *sk);
438
439 /* tcp_input.c */
440 extern void tcp_cwnd_application_limited(struct sock *sk);
441
442 /* tcp_timer.c */
443 extern void tcp_init_xmit_timers(struct sock *);
444 static inline void tcp_clear_xmit_timers(struct sock *sk)
445 {
446 inet_csk_clear_xmit_timers(sk);
447 }
448
449 extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu);
450 extern unsigned int tcp_current_mss(struct sock *sk, int large);
451
452 /* tcp.c */
453 extern void tcp_get_info(struct sock *, struct tcp_info *);
454
455 /* Read 'sendfile()'-style from a TCP socket */
456 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
457 unsigned int, size_t);
458 extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
459 sk_read_actor_t recv_actor);
460
461 extern void tcp_initialize_rcv_mss(struct sock *sk);
462
463 extern int tcp_mtu_to_mss(struct sock *sk, int pmtu);
464 extern int tcp_mss_to_mtu(struct sock *sk, int mss);
465 extern void tcp_mtup_init(struct sock *sk);
466
467 static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd)
468 {
469 tp->pred_flags = htonl((tp->tcp_header_len << 26) |
470 ntohl(TCP_FLAG_ACK) |
471 snd_wnd);
472 }
473
474 static inline void tcp_fast_path_on(struct tcp_sock *tp)
475 {
476 __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale);
477 }
478
479 static inline void tcp_fast_path_check(struct sock *sk, struct tcp_sock *tp)
480 {
481 if (skb_queue_empty(&tp->out_of_order_queue) &&
482 tp->rcv_wnd &&
483 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
484 !tp->urg_data)
485 tcp_fast_path_on(tp);
486 }
487
488 /* Compute the actual receive window we are currently advertising.
489 * Rcv_nxt can be after the window if our peer push more data
490 * than the offered window.
491 */
492 static inline u32 tcp_receive_window(const struct tcp_sock *tp)
493 {
494 s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt;
495
496 if (win < 0)
497 win = 0;
498 return (u32) win;
499 }
500
501 /* Choose a new window, without checks for shrinking, and without
502 * scaling applied to the result. The caller does these things
503 * if necessary. This is a "raw" window selection.
504 */
505 extern u32 __tcp_select_window(struct sock *sk);
506
507 /* TCP timestamps are only 32-bits, this causes a slight
508 * complication on 64-bit systems since we store a snapshot
509 * of jiffies in the buffer control blocks below. We decided
510 * to use only the low 32-bits of jiffies and hide the ugly
511 * casts with the following macro.
512 */
513 #define tcp_time_stamp ((__u32)(jiffies))
514
515 /* This is what the send packet queuing engine uses to pass
516 * TCP per-packet control information to the transmission
517 * code. We also store the host-order sequence numbers in
518 * here too. This is 36 bytes on 32-bit architectures,
519 * 40 bytes on 64-bit machines, if this grows please adjust
520 * skbuff.h:skbuff->cb[xxx] size appropriately.
521 */
522 struct tcp_skb_cb {
523 union {
524 struct inet_skb_parm h4;
525 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
526 struct inet6_skb_parm h6;
527 #endif
528 } header; /* For incoming frames */
529 __u32 seq; /* Starting sequence number */
530 __u32 end_seq; /* SEQ + FIN + SYN + datalen */
531 __u32 when; /* used to compute rtt's */
532 __u8 flags; /* TCP header flags. */
533
534 /* NOTE: These must match up to the flags byte in a
535 * real TCP header.
536 */
537 #define TCPCB_FLAG_FIN 0x01
538 #define TCPCB_FLAG_SYN 0x02
539 #define TCPCB_FLAG_RST 0x04
540 #define TCPCB_FLAG_PSH 0x08
541 #define TCPCB_FLAG_ACK 0x10
542 #define TCPCB_FLAG_URG 0x20
543 #define TCPCB_FLAG_ECE 0x40
544 #define TCPCB_FLAG_CWR 0x80
545
546 __u8 sacked; /* State flags for SACK/FACK. */
547 #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
548 #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
549 #define TCPCB_LOST 0x04 /* SKB is lost */
550 #define TCPCB_TAGBITS 0x07 /* All tag bits */
551
552 #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */
553 #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
554
555 #define TCPCB_URG 0x20 /* Urgent pointer advanced here */
556
557 #define TCPCB_AT_TAIL (TCPCB_URG)
558
559 __u16 urg_ptr; /* Valid w/URG flags is set. */
560 __u32 ack_seq; /* Sequence number ACK'd */
561 };
562
563 #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
564
565 #include <net/tcp_ecn.h>
566
567 /* Due to TSO, an SKB can be composed of multiple actual
568 * packets. To keep these tracked properly, we use this.
569 */
570 static inline int tcp_skb_pcount(const struct sk_buff *skb)
571 {
572 return skb_shinfo(skb)->gso_segs;
573 }
574
575 /* This is valid iff tcp_skb_pcount() > 1. */
576 static inline int tcp_skb_mss(const struct sk_buff *skb)
577 {
578 return skb_shinfo(skb)->gso_size;
579 }
580
581 static inline void tcp_dec_pcount_approx(__u32 *count,
582 const struct sk_buff *skb)
583 {
584 if (*count) {
585 *count -= tcp_skb_pcount(skb);
586 if ((int)*count < 0)
587 *count = 0;
588 }
589 }
590
591 static inline void tcp_packets_out_inc(struct sock *sk,
592 struct tcp_sock *tp,
593 const struct sk_buff *skb)
594 {
595 int orig = tp->packets_out;
596
597 tp->packets_out += tcp_skb_pcount(skb);
598 if (!orig)
599 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
600 inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
601 }
602
603 static inline void tcp_packets_out_dec(struct tcp_sock *tp,
604 const struct sk_buff *skb)
605 {
606 tp->packets_out -= tcp_skb_pcount(skb);
607 }
608
609 /* Events passed to congestion control interface */
610 enum tcp_ca_event {
611 CA_EVENT_TX_START, /* first transmit when no packets in flight */
612 CA_EVENT_CWND_RESTART, /* congestion window restart */
613 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
614 CA_EVENT_FRTO, /* fast recovery timeout */
615 CA_EVENT_LOSS, /* loss timeout */
616 CA_EVENT_FAST_ACK, /* in sequence ack */
617 CA_EVENT_SLOW_ACK, /* other ack */
618 };
619
620 /*
621 * Interface for adding new TCP congestion control handlers
622 */
623 #define TCP_CA_NAME_MAX 16
624 #define TCP_CA_MAX 128
625 #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX)
626
627 struct tcp_congestion_ops {
628 struct list_head list;
629 int non_restricted;
630
631 /* initialize private data (optional) */
632 void (*init)(struct sock *sk);
633 /* cleanup private data (optional) */
634 void (*release)(struct sock *sk);
635
636 /* return slow start threshold (required) */
637 u32 (*ssthresh)(struct sock *sk);
638 /* lower bound for congestion window (optional) */
639 u32 (*min_cwnd)(const struct sock *sk);
640 /* do new cwnd calculation (required) */
641 void (*cong_avoid)(struct sock *sk, u32 ack,
642 u32 rtt, u32 in_flight, int good_ack);
643 /* round trip time sample per acked packet (optional) */
644 void (*rtt_sample)(struct sock *sk, u32 usrtt);
645 /* call before changing ca_state (optional) */
646 void (*set_state)(struct sock *sk, u8 new_state);
647 /* call when cwnd event occurs (optional) */
648 void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
649 /* new value of cwnd after loss (optional) */
650 u32 (*undo_cwnd)(struct sock *sk);
651 /* hook for packet ack accounting (optional) */
652 void (*pkts_acked)(struct sock *sk, u32 num_acked);
653 /* get info for inet_diag (optional) */
654 void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb);
655
656 char name[TCP_CA_NAME_MAX];
657 struct module *owner;
658 };
659
660 extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
661 extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
662
663 extern void tcp_init_congestion_control(struct sock *sk);
664 extern void tcp_cleanup_congestion_control(struct sock *sk);
665 extern int tcp_set_default_congestion_control(const char *name);
666 extern void tcp_get_default_congestion_control(char *name);
667 extern void tcp_get_available_congestion_control(char *buf, size_t len);
668 extern void tcp_get_allowed_congestion_control(char *buf, size_t len);
669 extern int tcp_set_allowed_congestion_control(char *allowed);
670 extern int tcp_set_congestion_control(struct sock *sk, const char *name);
671 extern void tcp_slow_start(struct tcp_sock *tp);
672
673 extern struct tcp_congestion_ops tcp_init_congestion_ops;
674 extern u32 tcp_reno_ssthresh(struct sock *sk);
675 extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack,
676 u32 rtt, u32 in_flight, int flag);
677 extern u32 tcp_reno_min_cwnd(const struct sock *sk);
678 extern struct tcp_congestion_ops tcp_reno;
679
680 static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state)
681 {
682 struct inet_connection_sock *icsk = inet_csk(sk);
683
684 if (icsk->icsk_ca_ops->set_state)
685 icsk->icsk_ca_ops->set_state(sk, ca_state);
686 icsk->icsk_ca_state = ca_state;
687 }
688
689 static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event)
690 {
691 const struct inet_connection_sock *icsk = inet_csk(sk);
692
693 if (icsk->icsk_ca_ops->cwnd_event)
694 icsk->icsk_ca_ops->cwnd_event(sk, event);
695 }
696
697 /* This determines how many packets are "in the network" to the best
698 * of our knowledge. In many cases it is conservative, but where
699 * detailed information is available from the receiver (via SACK
700 * blocks etc.) we can make more aggressive calculations.
701 *
702 * Use this for decisions involving congestion control, use just
703 * tp->packets_out to determine if the send queue is empty or not.
704 *
705 * Read this equation as:
706 *
707 * "Packets sent once on transmission queue" MINUS
708 * "Packets left network, but not honestly ACKed yet" PLUS
709 * "Packets fast retransmitted"
710 */
711 static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
712 {
713 return (tp->packets_out - tp->left_out + tp->retrans_out);
714 }
715
716 /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
717 * The exception is rate halving phase, when cwnd is decreasing towards
718 * ssthresh.
719 */
720 static inline __u32 tcp_current_ssthresh(const struct sock *sk)
721 {
722 const struct tcp_sock *tp = tcp_sk(sk);
723 if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery))
724 return tp->snd_ssthresh;
725 else
726 return max(tp->snd_ssthresh,
727 ((tp->snd_cwnd >> 1) +
728 (tp->snd_cwnd >> 2)));
729 }
730
731 static inline void tcp_sync_left_out(struct tcp_sock *tp)
732 {
733 if (tp->rx_opt.sack_ok &&
734 (tp->sacked_out >= tp->packets_out - tp->lost_out))
735 tp->sacked_out = tp->packets_out - tp->lost_out;
736 tp->left_out = tp->sacked_out + tp->lost_out;
737 }
738
739 extern void tcp_enter_cwr(struct sock *sk);
740 extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst);
741
742 /* Slow start with delack produces 3 packets of burst, so that
743 * it is safe "de facto".
744 */
745 static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
746 {
747 return 3;
748 }
749
750 /* RFC2861 Check whether we are limited by application or congestion window
751 * This is the inverse of cwnd check in tcp_tso_should_defer
752 */
753 static inline int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight)
754 {
755 const struct tcp_sock *tp = tcp_sk(sk);
756 u32 left;
757
758 if (in_flight >= tp->snd_cwnd)
759 return 1;
760
761 if (!sk_can_gso(sk))
762 return 0;
763
764 left = tp->snd_cwnd - in_flight;
765 if (sysctl_tcp_tso_win_divisor)
766 return left * sysctl_tcp_tso_win_divisor < tp->snd_cwnd;
767 else
768 return left <= tcp_max_burst(tp);
769 }
770
771 static inline void tcp_minshall_update(struct tcp_sock *tp, int mss,
772 const struct sk_buff *skb)
773 {
774 if (skb->len < mss)
775 tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
776 }
777
778 static inline void tcp_check_probe_timer(struct sock *sk, struct tcp_sock *tp)
779 {
780 const struct inet_connection_sock *icsk = inet_csk(sk);
781 if (!tp->packets_out && !icsk->icsk_pending)
782 inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
783 icsk->icsk_rto, TCP_RTO_MAX);
784 }
785
786 static inline void tcp_push_pending_frames(struct sock *sk,
787 struct tcp_sock *tp)
788 {
789 __tcp_push_pending_frames(sk, tp, tcp_current_mss(sk, 1), tp->nonagle);
790 }
791
792 static inline void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq)
793 {
794 tp->snd_wl1 = seq;
795 }
796
797 static inline void tcp_update_wl(struct tcp_sock *tp, u32 ack, u32 seq)
798 {
799 tp->snd_wl1 = seq;
800 }
801
802 /*
803 * Calculate(/check) TCP checksum
804 */
805 static inline __sum16 tcp_v4_check(int len, __be32 saddr,
806 __be32 daddr, __wsum base)
807 {
808 return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base);
809 }
810
811 static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb)
812 {
813 return __skb_checksum_complete(skb);
814 }
815
816 static inline int tcp_checksum_complete(struct sk_buff *skb)
817 {
818 return skb->ip_summed != CHECKSUM_UNNECESSARY &&
819 __tcp_checksum_complete(skb);
820 }
821
822 /* Prequeue for VJ style copy to user, combined with checksumming. */
823
824 static inline void tcp_prequeue_init(struct tcp_sock *tp)
825 {
826 tp->ucopy.task = NULL;
827 tp->ucopy.len = 0;
828 tp->ucopy.memory = 0;
829 skb_queue_head_init(&tp->ucopy.prequeue);
830 #ifdef CONFIG_NET_DMA
831 tp->ucopy.dma_chan = NULL;
832 tp->ucopy.wakeup = 0;
833 tp->ucopy.pinned_list = NULL;
834 tp->ucopy.dma_cookie = 0;
835 #endif
836 }
837
838 /* Packet is added to VJ-style prequeue for processing in process
839 * context, if a reader task is waiting. Apparently, this exciting
840 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
841 * failed somewhere. Latency? Burstiness? Well, at least now we will
842 * see, why it failed. 8)8) --ANK
843 *
844 * NOTE: is this not too big to inline?
845 */
846 static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb)
847 {
848 struct tcp_sock *tp = tcp_sk(sk);
849
850 if (!sysctl_tcp_low_latency && tp->ucopy.task) {
851 __skb_queue_tail(&tp->ucopy.prequeue, skb);
852 tp->ucopy.memory += skb->truesize;
853 if (tp->ucopy.memory > sk->sk_rcvbuf) {
854 struct sk_buff *skb1;
855
856 BUG_ON(sock_owned_by_user(sk));
857
858 while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) {
859 sk->sk_backlog_rcv(sk, skb1);
860 NET_INC_STATS_BH(LINUX_MIB_TCPPREQUEUEDROPPED);
861 }
862
863 tp->ucopy.memory = 0;
864 } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
865 wake_up_interruptible(sk->sk_sleep);
866 if (!inet_csk_ack_scheduled(sk))
867 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
868 (3 * TCP_RTO_MIN) / 4,
869 TCP_RTO_MAX);
870 }
871 return 1;
872 }
873 return 0;
874 }
875
876
877 #undef STATE_TRACE
878
879 #ifdef STATE_TRACE
880 static const char *statename[]={
881 "Unused","Established","Syn Sent","Syn Recv",
882 "Fin Wait 1","Fin Wait 2","Time Wait", "Close",
883 "Close Wait","Last ACK","Listen","Closing"
884 };
885 #endif
886
887 static inline void tcp_set_state(struct sock *sk, int state)
888 {
889 int oldstate = sk->sk_state;
890
891 switch (state) {
892 case TCP_ESTABLISHED:
893 if (oldstate != TCP_ESTABLISHED)
894 TCP_INC_STATS(TCP_MIB_CURRESTAB);
895 break;
896
897 case TCP_CLOSE:
898 if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
899 TCP_INC_STATS(TCP_MIB_ESTABRESETS);
900
901 sk->sk_prot->unhash(sk);
902 if (inet_csk(sk)->icsk_bind_hash &&
903 !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
904 inet_put_port(&tcp_hashinfo, sk);
905 /* fall through */
906 default:
907 if (oldstate==TCP_ESTABLISHED)
908 TCP_DEC_STATS(TCP_MIB_CURRESTAB);
909 }
910
911 /* Change state AFTER socket is unhashed to avoid closed
912 * socket sitting in hash tables.
913 */
914 sk->sk_state = state;
915
916 #ifdef STATE_TRACE
917 SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]);
918 #endif
919 }
920
921 static inline void tcp_done(struct sock *sk)
922 {
923 if(sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
924 TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
925
926 tcp_set_state(sk, TCP_CLOSE);
927 tcp_clear_xmit_timers(sk);
928
929 sk->sk_shutdown = SHUTDOWN_MASK;
930
931 if (!sock_flag(sk, SOCK_DEAD))
932 sk->sk_state_change(sk);
933 else
934 inet_csk_destroy_sock(sk);
935 }
936
937 static inline void tcp_sack_reset(struct tcp_options_received *rx_opt)
938 {
939 rx_opt->dsack = 0;
940 rx_opt->eff_sacks = 0;
941 rx_opt->num_sacks = 0;
942 }
943
944 /* Determine a window scaling and initial window to offer. */
945 extern void tcp_select_initial_window(int __space, __u32 mss,
946 __u32 *rcv_wnd, __u32 *window_clamp,
947 int wscale_ok, __u8 *rcv_wscale);
948
949 static inline int tcp_win_from_space(int space)
950 {
951 return sysctl_tcp_adv_win_scale<=0 ?
952 (space>>(-sysctl_tcp_adv_win_scale)) :
953 space - (space>>sysctl_tcp_adv_win_scale);
954 }
955
956 /* Note: caller must be prepared to deal with negative returns */
957 static inline int tcp_space(const struct sock *sk)
958 {
959 return tcp_win_from_space(sk->sk_rcvbuf -
960 atomic_read(&sk->sk_rmem_alloc));
961 }
962
963 static inline int tcp_full_space(const struct sock *sk)
964 {
965 return tcp_win_from_space(sk->sk_rcvbuf);
966 }
967
968 static inline void tcp_openreq_init(struct request_sock *req,
969 struct tcp_options_received *rx_opt,
970 struct sk_buff *skb)
971 {
972 struct inet_request_sock *ireq = inet_rsk(req);
973
974 req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */
975 tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
976 req->mss = rx_opt->mss_clamp;
977 req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
978 ireq->tstamp_ok = rx_opt->tstamp_ok;
979 ireq->sack_ok = rx_opt->sack_ok;
980 ireq->snd_wscale = rx_opt->snd_wscale;
981 ireq->wscale_ok = rx_opt->wscale_ok;
982 ireq->acked = 0;
983 ireq->ecn_ok = 0;
984 ireq->rmt_port = skb->h.th->source;
985 }
986
987 extern void tcp_enter_memory_pressure(void);
988
989 static inline int keepalive_intvl_when(const struct tcp_sock *tp)
990 {
991 return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl;
992 }
993
994 static inline int keepalive_time_when(const struct tcp_sock *tp)
995 {
996 return tp->keepalive_time ? : sysctl_tcp_keepalive_time;
997 }
998
999 static inline int tcp_fin_time(const struct sock *sk)
1000 {
1001 int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout;
1002 const int rto = inet_csk(sk)->icsk_rto;
1003
1004 if (fin_timeout < (rto << 2) - (rto >> 1))
1005 fin_timeout = (rto << 2) - (rto >> 1);
1006
1007 return fin_timeout;
1008 }
1009
1010 static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, int rst)
1011 {
1012 if ((s32)(rx_opt->rcv_tsval - rx_opt->ts_recent) >= 0)
1013 return 0;
1014 if (xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)
1015 return 0;
1016
1017 /* RST segments are not recommended to carry timestamp,
1018 and, if they do, it is recommended to ignore PAWS because
1019 "their cleanup function should take precedence over timestamps."
1020 Certainly, it is mistake. It is necessary to understand the reasons
1021 of this constraint to relax it: if peer reboots, clock may go
1022 out-of-sync and half-open connections will not be reset.
1023 Actually, the problem would be not existing if all
1024 the implementations followed draft about maintaining clock
1025 via reboots. Linux-2.2 DOES NOT!
1026
1027 However, we can relax time bounds for RST segments to MSL.
1028 */
1029 if (rst && xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
1030 return 0;
1031 return 1;
1032 }
1033
1034 #define TCP_CHECK_TIMER(sk) do { } while (0)
1035
1036 static inline int tcp_use_frto(const struct sock *sk)
1037 {
1038 const struct tcp_sock *tp = tcp_sk(sk);
1039
1040 /* F-RTO must be activated in sysctl and there must be some
1041 * unsent new data, and the advertised window should allow
1042 * sending it.
1043 */
1044 return (sysctl_tcp_frto && sk->sk_send_head &&
1045 !after(TCP_SKB_CB(sk->sk_send_head)->end_seq,
1046 tp->snd_una + tp->snd_wnd));
1047 }
1048
1049 static inline void tcp_mib_init(void)
1050 {
1051 /* See RFC 2012 */
1052 TCP_ADD_STATS_USER(TCP_MIB_RTOALGORITHM, 1);
1053 TCP_ADD_STATS_USER(TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ);
1054 TCP_ADD_STATS_USER(TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ);
1055 TCP_ADD_STATS_USER(TCP_MIB_MAXCONN, -1);
1056 }
1057
1058 /*from STCP */
1059 static inline void clear_all_retrans_hints(struct tcp_sock *tp){
1060 tp->lost_skb_hint = NULL;
1061 tp->scoreboard_skb_hint = NULL;
1062 tp->retransmit_skb_hint = NULL;
1063 tp->forward_skb_hint = NULL;
1064 tp->fastpath_skb_hint = NULL;
1065 }
1066
1067 /* MD5 Signature */
1068 struct crypto_hash;
1069
1070 /* - key database */
1071 struct tcp_md5sig_key {
1072 u8 *key;
1073 u8 keylen;
1074 };
1075
1076 struct tcp4_md5sig_key {
1077 u8 *key;
1078 u16 keylen;
1079 __be32 addr;
1080 };
1081
1082 struct tcp6_md5sig_key {
1083 u8 *key;
1084 u16 keylen;
1085 #if 0
1086 u32 scope_id; /* XXX */
1087 #endif
1088 struct in6_addr addr;
1089 };
1090
1091 /* - sock block */
1092 struct tcp_md5sig_info {
1093 struct tcp4_md5sig_key *keys4;
1094 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1095 struct tcp6_md5sig_key *keys6;
1096 u32 entries6;
1097 u32 alloced6;
1098 #endif
1099 u32 entries4;
1100 u32 alloced4;
1101 };
1102
1103 /* - pseudo header */
1104 struct tcp4_pseudohdr {
1105 __be32 saddr;
1106 __be32 daddr;
1107 __u8 pad;
1108 __u8 protocol;
1109 __be16 len;
1110 };
1111
1112 struct tcp6_pseudohdr {
1113 struct in6_addr saddr;
1114 struct in6_addr daddr;
1115 __be32 len;
1116 __be32 protocol; /* including padding */
1117 };
1118
1119 union tcp_md5sum_block {
1120 struct tcp4_pseudohdr ip4;
1121 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1122 struct tcp6_pseudohdr ip6;
1123 #endif
1124 };
1125
1126 /* - pool: digest algorithm, hash description and scratch buffer */
1127 struct tcp_md5sig_pool {
1128 struct hash_desc md5_desc;
1129 union tcp_md5sum_block md5_blk;
1130 };
1131
1132 #define TCP_MD5SIG_MAXKEYS (~(u32)0) /* really?! */
1133
1134 /* - functions */
1135 extern int tcp_v4_calc_md5_hash(char *md5_hash,
1136 struct tcp_md5sig_key *key,
1137 struct sock *sk,
1138 struct dst_entry *dst,
1139 struct request_sock *req,
1140 struct tcphdr *th,
1141 int protocol, int tcplen);
1142 extern struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
1143 struct sock *addr_sk);
1144
1145 extern int tcp_v4_md5_do_add(struct sock *sk,
1146 __be32 addr,
1147 u8 *newkey,
1148 u8 newkeylen);
1149
1150 extern int tcp_v4_md5_do_del(struct sock *sk,
1151 __be32 addr);
1152
1153 extern struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void);
1154 extern void tcp_free_md5sig_pool(void);
1155
1156 extern struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu);
1157 extern void __tcp_put_md5sig_pool(void);
1158
1159 static inline
1160 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
1161 {
1162 int cpu = get_cpu();
1163 struct tcp_md5sig_pool *ret = __tcp_get_md5sig_pool(cpu);
1164 if (!ret)
1165 put_cpu();
1166 return ret;
1167 }
1168
1169 static inline void tcp_put_md5sig_pool(void)
1170 {
1171 __tcp_put_md5sig_pool();
1172 put_cpu();
1173 }
1174
1175 /* /proc */
1176 enum tcp_seq_states {
1177 TCP_SEQ_STATE_LISTENING,
1178 TCP_SEQ_STATE_OPENREQ,
1179 TCP_SEQ_STATE_ESTABLISHED,
1180 TCP_SEQ_STATE_TIME_WAIT,
1181 };
1182
1183 struct tcp_seq_afinfo {
1184 struct module *owner;
1185 char *name;
1186 sa_family_t family;
1187 int (*seq_show) (struct seq_file *m, void *v);
1188 struct file_operations *seq_fops;
1189 };
1190
1191 struct tcp_iter_state {
1192 sa_family_t family;
1193 enum tcp_seq_states state;
1194 struct sock *syn_wait_sk;
1195 int bucket, sbucket, num, uid;
1196 struct seq_operations seq_ops;
1197 };
1198
1199 extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo);
1200 extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo);
1201
1202 extern struct request_sock_ops tcp_request_sock_ops;
1203
1204 extern int tcp_v4_destroy_sock(struct sock *sk);
1205
1206 extern int tcp_v4_gso_send_check(struct sk_buff *skb);
1207 extern struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features);
1208
1209 #ifdef CONFIG_PROC_FS
1210 extern int tcp4_proc_init(void);
1211 extern void tcp4_proc_exit(void);
1212 #endif
1213
1214 /* TCP af-specific functions */
1215 struct tcp_sock_af_ops {
1216 #ifdef CONFIG_TCP_MD5SIG
1217 struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
1218 struct sock *addr_sk);
1219 int (*calc_md5_hash) (char *location,
1220 struct tcp_md5sig_key *md5,
1221 struct sock *sk,
1222 struct dst_entry *dst,
1223 struct request_sock *req,
1224 struct tcphdr *th,
1225 int protocol, int len);
1226 int (*md5_add) (struct sock *sk,
1227 struct sock *addr_sk,
1228 u8 *newkey,
1229 u8 len);
1230 int (*md5_parse) (struct sock *sk,
1231 char __user *optval,
1232 int optlen);
1233 #endif
1234 };
1235
1236 struct tcp_request_sock_ops {
1237 #ifdef CONFIG_TCP_MD5SIG
1238 struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
1239 struct request_sock *req);
1240 #endif
1241 };
1242
1243 extern void tcp_v4_init(struct net_proto_family *ops);
1244 extern void tcp_init(void);
1245
1246 #endif /* _TCP_H */
kernel source for telekom puls (alcatel/mediatek)