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Fix NULL ptr regression in powernow-k8
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / include / net / tcp.h
blob646dbe3962eab7ae3832c9e8641549ef9e9d95f9
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 #include <linux/cryptohash.h>
33
34 #include <net/inet_connection_sock.h>
35 #include <net/inet_timewait_sock.h>
36 #include <net/inet_hashtables.h>
37 #include <net/checksum.h>
38 #include <net/request_sock.h>
39 #include <net/sock.h>
40 #include <net/snmp.h>
41 #include <net/ip.h>
42 #include <net/tcp_states.h>
43 #include <net/inet_ecn.h>
44 #include <net/dst.h>
45
46 #include <linux/seq_file.h>
47
48 extern struct inet_hashinfo tcp_hashinfo;
49
50 extern struct percpu_counter tcp_orphan_count;
51 extern void tcp_time_wait(struct sock *sk, int state, int timeo);
52
53 #define MAX_TCP_HEADER (128 + MAX_HEADER)
54 #define MAX_TCP_OPTION_SPACE 40
55
56 /*
57 * Never offer a window over 32767 without using window scaling. Some
58 * poor stacks do signed 16bit maths!
59 */
60 #define MAX_TCP_WINDOW 32767U
61
62 /* Minimal accepted MSS. It is (60+60+8) - (20+20). */
63 #define TCP_MIN_MSS 88U
64
65 /* Minimal RCV_MSS. */
66 #define TCP_MIN_RCVMSS 536U
67
68 /* The least MTU to use for probing */
69 #define TCP_BASE_MSS 512
70
71 /* After receiving this amount of duplicate ACKs fast retransmit starts. */
72 #define TCP_FASTRETRANS_THRESH 3
73
74 /* Maximal reordering. */
75 #define TCP_MAX_REORDERING 127
76
77 /* Maximal number of ACKs sent quickly to accelerate slow-start. */
78 #define TCP_MAX_QUICKACKS 16U
79
80 /* urg_data states */
81 #define TCP_URG_VALID 0x0100
82 #define TCP_URG_NOTYET 0x0200
83 #define TCP_URG_READ 0x0400
84
85 #define TCP_RETR1 3 /*
86 * This is how many retries it does before it
87 * tries to figure out if the gateway is
88 * down. Minimal RFC value is 3; it corresponds
89 * to ~3sec-8min depending on RTO.
90 */
91
92 #define TCP_RETR2 15 /*
93 * This should take at least
94 * 90 minutes to time out.
95 * RFC1122 says that the limit is 100 sec.
96 * 15 is ~13-30min depending on RTO.
97 */
98
99 #define TCP_SYN_RETRIES 5 /* number of times to retry active opening a
100 * connection: ~180sec is RFC minimum */
101
102 #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a
103 * connection: ~180sec is RFC minimum */
104
105
106 #define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned
107 * socket. 7 is ~50sec-16min.
108 */
109
110
111 #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT
112 * state, about 60 seconds */
113 #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN
114 /* BSD style FIN_WAIT2 deadlock breaker.
115 * It used to be 3min, new value is 60sec,
116 * to combine FIN-WAIT-2 timeout with
117 * TIME-WAIT timer.
118 */
119
120 #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */
121 #if HZ >= 100
122 #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */
123 #define TCP_ATO_MIN ((unsigned)(HZ/25))
124 #else
125 #define TCP_DELACK_MIN 4U
126 #define TCP_ATO_MIN 4U
127 #endif
128 #define TCP_RTO_MAX ((unsigned)(120*HZ))
129 #define TCP_RTO_MIN ((unsigned)(HZ/5))
130 #define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */
131
132 #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
133 * for local resources.
134 */
135
136 #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */
137 #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */
138 #define TCP_KEEPALIVE_INTVL (75*HZ)
139
140 #define MAX_TCP_KEEPIDLE 32767
141 #define MAX_TCP_KEEPINTVL 32767
142 #define MAX_TCP_KEEPCNT 127
143 #define MAX_TCP_SYNCNT 127
144
145 #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */
146
147 #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24)
148 #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated
149 * after this time. It should be equal
150 * (or greater than) TCP_TIMEWAIT_LEN
151 * to provide reliability equal to one
152 * provided by timewait state.
153 */
154 #define TCP_PAWS_WINDOW 1 /* Replay window for per-host
155 * timestamps. It must be less than
156 * minimal timewait lifetime.
157 */
158 /*
159 * TCP option
160 */
161
162 #define TCPOPT_NOP 1 /* Padding */
163 #define TCPOPT_EOL 0 /* End of options */
164 #define TCPOPT_MSS 2 /* Segment size negotiating */
165 #define TCPOPT_WINDOW 3 /* Window scaling */
166 #define TCPOPT_SACK_PERM 4 /* SACK Permitted */
167 #define TCPOPT_SACK 5 /* SACK Block */
168 #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
169 #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */
170
171 /*
172 * TCP option lengths
173 */
174
175 #define TCPOLEN_MSS 4
176 #define TCPOLEN_WINDOW 3
177 #define TCPOLEN_SACK_PERM 2
178 #define TCPOLEN_TIMESTAMP 10
179 #define TCPOLEN_MD5SIG 18
180
181 /* But this is what stacks really send out. */
182 #define TCPOLEN_TSTAMP_ALIGNED 12
183 #define TCPOLEN_WSCALE_ALIGNED 4
184 #define TCPOLEN_SACKPERM_ALIGNED 4
185 #define TCPOLEN_SACK_BASE 2
186 #define TCPOLEN_SACK_BASE_ALIGNED 4
187 #define TCPOLEN_SACK_PERBLOCK 8
188 #define TCPOLEN_MD5SIG_ALIGNED 20
189 #define TCPOLEN_MSS_ALIGNED 4
190
191 /* Flags in tp->nonagle */
192 #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
193 #define TCP_NAGLE_CORK 2 /* Socket is corked */
194 #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */
195
196 extern struct inet_timewait_death_row tcp_death_row;
197
198 /* sysctl variables for tcp */
199 extern int sysctl_tcp_timestamps;
200 extern int sysctl_tcp_window_scaling;
201 extern int sysctl_tcp_sack;
202 extern int sysctl_tcp_fin_timeout;
203 extern int sysctl_tcp_keepalive_time;
204 extern int sysctl_tcp_keepalive_probes;
205 extern int sysctl_tcp_keepalive_intvl;
206 extern int sysctl_tcp_syn_retries;
207 extern int sysctl_tcp_synack_retries;
208 extern int sysctl_tcp_retries1;
209 extern int sysctl_tcp_retries2;
210 extern int sysctl_tcp_orphan_retries;
211 extern int sysctl_tcp_syncookies;
212 extern int sysctl_tcp_retrans_collapse;
213 extern int sysctl_tcp_stdurg;
214 extern int sysctl_tcp_rfc1337;
215 extern int sysctl_tcp_abort_on_overflow;
216 extern int sysctl_tcp_max_orphans;
217 extern int sysctl_tcp_fack;
218 extern int sysctl_tcp_reordering;
219 extern int sysctl_tcp_ecn;
220 extern int sysctl_tcp_dsack;
221 extern int sysctl_tcp_mem[3];
222 extern int sysctl_tcp_wmem[3];
223 extern int sysctl_tcp_rmem[3];
224 extern int sysctl_tcp_app_win;
225 extern int sysctl_tcp_adv_win_scale;
226 extern int sysctl_tcp_tw_reuse;
227 extern int sysctl_tcp_frto;
228 extern int sysctl_tcp_frto_response;
229 extern int sysctl_tcp_low_latency;
230 extern int sysctl_tcp_dma_copybreak;
231 extern int sysctl_tcp_nometrics_save;
232 extern int sysctl_tcp_moderate_rcvbuf;
233 extern int sysctl_tcp_tso_win_divisor;
234 extern int sysctl_tcp_abc;
235 extern int sysctl_tcp_mtu_probing;
236 extern int sysctl_tcp_base_mss;
237 extern int sysctl_tcp_workaround_signed_windows;
238 extern int sysctl_tcp_slow_start_after_idle;
239 extern int sysctl_tcp_max_ssthresh;
240
241 extern atomic_t tcp_memory_allocated;
242 extern struct percpu_counter tcp_sockets_allocated;
243 extern int tcp_memory_pressure;
244
245 /*
246 * The next routines deal with comparing 32 bit unsigned ints
247 * and worry about wraparound (automatic with unsigned arithmetic).
248 */
249
250 static inline int before(__u32 seq1, __u32 seq2)
251 {
252 return (__s32)(seq1-seq2) < 0;
253 }
254 #define after(seq2, seq1) before(seq1, seq2)
255
256 /* is s2<=s1<=s3 ? */
257 static inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
258 {
259 return seq3 - seq2 >= seq1 - seq2;
260 }
261
262 static inline int tcp_too_many_orphans(struct sock *sk, int num)
263 {
264 return (num > sysctl_tcp_max_orphans) ||
265 (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
266 atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2]);
267 }
268
269 extern struct proto tcp_prot;
270
271 #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field)
272 #define TCP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.tcp_statistics, field)
273 #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field)
274 #define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val)
275
276 extern void tcp_v4_err(struct sk_buff *skb, u32);
277
278 extern void tcp_shutdown (struct sock *sk, int how);
279
280 extern int tcp_v4_rcv(struct sk_buff *skb);
281
282 extern int tcp_v4_remember_stamp(struct sock *sk);
283
284 extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
285
286 extern int tcp_sendmsg(struct kiocb *iocb, struct socket *sock,
287 struct msghdr *msg, size_t size);
288 extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags);
289
290 extern int tcp_ioctl(struct sock *sk,
291 int cmd,
292 unsigned long arg);
293
294 extern int tcp_rcv_state_process(struct sock *sk,
295 struct sk_buff *skb,
296 struct tcphdr *th,
297 unsigned len);
298
299 extern int tcp_rcv_established(struct sock *sk,
300 struct sk_buff *skb,
301 struct tcphdr *th,
302 unsigned len);
303
304 extern void tcp_rcv_space_adjust(struct sock *sk);
305
306 extern void tcp_cleanup_rbuf(struct sock *sk, int copied);
307
308 extern int tcp_twsk_unique(struct sock *sk,
309 struct sock *sktw, void *twp);
310
311 extern void tcp_twsk_destructor(struct sock *sk);
312
313 extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos,
314 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
315
316 static inline void tcp_dec_quickack_mode(struct sock *sk,
317 const unsigned int pkts)
318 {
319 struct inet_connection_sock *icsk = inet_csk(sk);
320
321 if (icsk->icsk_ack.quick) {
322 if (pkts >= icsk->icsk_ack.quick) {
323 icsk->icsk_ack.quick = 0;
324 /* Leaving quickack mode we deflate ATO. */
325 icsk->icsk_ack.ato = TCP_ATO_MIN;
326 } else
327 icsk->icsk_ack.quick -= pkts;
328 }
329 }
330
331 extern void tcp_enter_quickack_mode(struct sock *sk);
332
333 static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
334 {
335 rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
336 }
337
338 #define TCP_ECN_OK 1
339 #define TCP_ECN_QUEUE_CWR 2
340 #define TCP_ECN_DEMAND_CWR 4
341
342 static __inline__ void
343 TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th)
344 {
345 if (sysctl_tcp_ecn && th->ece && th->cwr)
346 inet_rsk(req)->ecn_ok = 1;
347 }
348
349 enum tcp_tw_status
350 {
351 TCP_TW_SUCCESS = 0,
352 TCP_TW_RST = 1,
353 TCP_TW_ACK = 2,
354 TCP_TW_SYN = 3
355 };
356
357
358 extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw,
359 struct sk_buff *skb,
360 const struct tcphdr *th);
361
362 extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb,
363 struct request_sock *req,
364 struct request_sock **prev);
365 extern int tcp_child_process(struct sock *parent,
366 struct sock *child,
367 struct sk_buff *skb);
368 extern int tcp_use_frto(struct sock *sk);
369 extern void tcp_enter_frto(struct sock *sk);
370 extern void tcp_enter_loss(struct sock *sk, int how);
371 extern void tcp_clear_retrans(struct tcp_sock *tp);
372 extern void tcp_update_metrics(struct sock *sk);
373
374 extern void tcp_close(struct sock *sk,
375 long timeout);
376 extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait);
377
378 extern int tcp_getsockopt(struct sock *sk, int level,
379 int optname,
380 char __user *optval,
381 int __user *optlen);
382 extern int tcp_setsockopt(struct sock *sk, int level,
383 int optname, char __user *optval,
384 int optlen);
385 extern int compat_tcp_getsockopt(struct sock *sk,
386 int level, int optname,
387 char __user *optval, int __user *optlen);
388 extern int compat_tcp_setsockopt(struct sock *sk,
389 int level, int optname,
390 char __user *optval, int optlen);
391 extern void tcp_set_keepalive(struct sock *sk, int val);
392 extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk,
393 struct msghdr *msg,
394 size_t len, int nonblock,
395 int flags, int *addr_len);
396
397 extern void tcp_parse_options(struct sk_buff *skb,
398 struct tcp_options_received *opt_rx,
399 int estab);
400
401 extern u8 *tcp_parse_md5sig_option(struct tcphdr *th);
402
403 /*
404 * TCP v4 functions exported for the inet6 API
405 */
406
407 extern void tcp_v4_send_check(struct sock *sk, int len,
408 struct sk_buff *skb);
409
410 extern int tcp_v4_conn_request(struct sock *sk,
411 struct sk_buff *skb);
412
413 extern struct sock * tcp_create_openreq_child(struct sock *sk,
414 struct request_sock *req,
415 struct sk_buff *skb);
416
417 extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk,
418 struct sk_buff *skb,
419 struct request_sock *req,
420 struct dst_entry *dst);
421
422 extern int tcp_v4_do_rcv(struct sock *sk,
423 struct sk_buff *skb);
424
425 extern int tcp_v4_connect(struct sock *sk,
426 struct sockaddr *uaddr,
427 int addr_len);
428
429 extern int tcp_connect(struct sock *sk);
430
431 extern struct sk_buff * tcp_make_synack(struct sock *sk,
432 struct dst_entry *dst,
433 struct request_sock *req);
434
435 extern int tcp_disconnect(struct sock *sk, int flags);
436
437
438 /* From syncookies.c */
439 extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];
440 extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
441 struct ip_options *opt);
442 extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
443 __u16 *mss);
444
445 extern __u32 cookie_init_timestamp(struct request_sock *req);
446 extern void cookie_check_timestamp(struct tcp_options_received *tcp_opt);
447
448 /* From net/ipv6/syncookies.c */
449 extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb);
450 extern __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb,
451 __u16 *mss);
452
453 /* tcp_output.c */
454
455 extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
456 int nonagle);
457 extern int tcp_may_send_now(struct sock *sk);
458 extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);
459 extern void tcp_xmit_retransmit_queue(struct sock *);
460 extern void tcp_simple_retransmit(struct sock *);
461 extern int tcp_trim_head(struct sock *, struct sk_buff *, u32);
462 extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int);
463
464 extern void tcp_send_probe0(struct sock *);
465 extern void tcp_send_partial(struct sock *);
466 extern int tcp_write_wakeup(struct sock *);
467 extern void tcp_send_fin(struct sock *sk);
468 extern void tcp_send_active_reset(struct sock *sk, gfp_t priority);
469 extern int tcp_send_synack(struct sock *);
470 extern void tcp_push_one(struct sock *, unsigned int mss_now);
471 extern void tcp_send_ack(struct sock *sk);
472 extern void tcp_send_delayed_ack(struct sock *sk);
473
474 /* tcp_input.c */
475 extern void tcp_cwnd_application_limited(struct sock *sk);
476
477 /* tcp_timer.c */
478 extern void tcp_init_xmit_timers(struct sock *);
479 static inline void tcp_clear_xmit_timers(struct sock *sk)
480 {
481 inet_csk_clear_xmit_timers(sk);
482 }
483
484 extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu);
485 extern unsigned int tcp_current_mss(struct sock *sk);
486
487 /* Bound MSS / TSO packet size with the half of the window */
488 static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize)
489 {
490 if (tp->max_window && pktsize > (tp->max_window >> 1))
491 return max(tp->max_window >> 1, 68U - tp->tcp_header_len);
492 else
493 return pktsize;
494 }
495
496 /* tcp.c */
497 extern void tcp_get_info(struct sock *, struct tcp_info *);
498
499 /* Read 'sendfile()'-style from a TCP socket */
500 typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
501 unsigned int, size_t);
502 extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
503 sk_read_actor_t recv_actor);
504
505 extern void tcp_initialize_rcv_mss(struct sock *sk);
506
507 extern int tcp_mtu_to_mss(struct sock *sk, int pmtu);
508 extern int tcp_mss_to_mtu(struct sock *sk, int mss);
509 extern void tcp_mtup_init(struct sock *sk);
510
511 static 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
518 static 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
523 static inline void tcp_fast_path_check(struct sock *sk)
524 {
525 struct tcp_sock *tp = tcp_sk(sk);
526
527 if (skb_queue_empty(&tp->out_of_order_queue) &&
528 tp->rcv_wnd &&
529 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
530 !tp->urg_data)
531 tcp_fast_path_on(tp);
532 }
533
534 /* Compute the actual rto_min value */
535 static inline u32 tcp_rto_min(struct sock *sk)
536 {
537 struct dst_entry *dst = __sk_dst_get(sk);
538 u32 rto_min = TCP_RTO_MIN;
539
540 if (dst && dst_metric_locked(dst, RTAX_RTO_MIN))
541 rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN);
542 return rto_min;
543 }
544
545 /* Compute the actual receive window we are currently advertising.
546 * Rcv_nxt can be after the window if our peer push more data
547 * than the offered window.
548 */
549 static inline u32 tcp_receive_window(const struct tcp_sock *tp)
550 {
551 s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt;
552
553 if (win < 0)
554 win = 0;
555 return (u32) win;
556 }
557
558 /* Choose a new window, without checks for shrinking, and without
559 * scaling applied to the result. The caller does these things
560 * if necessary. This is a "raw" window selection.
561 */
562 extern u32 __tcp_select_window(struct sock *sk);
563
564 /* TCP timestamps are only 32-bits, this causes a slight
565 * complication on 64-bit systems since we store a snapshot
566 * of jiffies in the buffer control blocks below. We decided
567 * to use only the low 32-bits of jiffies and hide the ugly
568 * casts with the following macro.
569 */
570 #define tcp_time_stamp ((__u32)(jiffies))
571
572 /* This is what the send packet queuing engine uses to pass
573 * TCP per-packet control information to the transmission
574 * code. We also store the host-order sequence numbers in
575 * here too. This is 36 bytes on 32-bit architectures,
576 * 40 bytes on 64-bit machines, if this grows please adjust
577 * skbuff.h:skbuff->cb[xxx] size appropriately.
578 */
579 struct tcp_skb_cb {
580 union {
581 struct inet_skb_parm h4;
582 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
583 struct inet6_skb_parm h6;
584 #endif
585 } header; /* For incoming frames */
586 __u32 seq; /* Starting sequence number */
587 __u32 end_seq; /* SEQ + FIN + SYN + datalen */
588 __u32 when; /* used to compute rtt's */
589 __u8 flags; /* TCP header flags. */
590
591 /* NOTE: These must match up to the flags byte in a
592 * real TCP header.
593 */
594 #define TCPCB_FLAG_FIN 0x01
595 #define TCPCB_FLAG_SYN 0x02
596 #define TCPCB_FLAG_RST 0x04
597 #define TCPCB_FLAG_PSH 0x08
598 #define TCPCB_FLAG_ACK 0x10
599 #define TCPCB_FLAG_URG 0x20
600 #define TCPCB_FLAG_ECE 0x40
601 #define TCPCB_FLAG_CWR 0x80
602
603 __u8 sacked; /* State flags for SACK/FACK. */
604 #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
605 #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
606 #define TCPCB_LOST 0x04 /* SKB is lost */
607 #define TCPCB_TAGBITS 0x07 /* All tag bits */
608
609 #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */
610 #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
611
612 __u32 ack_seq; /* Sequence number ACK'd */
613 };
614
615 #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
616
617 /* Due to TSO, an SKB can be composed of multiple actual
618 * packets. To keep these tracked properly, we use this.
619 */
620 static inline int tcp_skb_pcount(const struct sk_buff *skb)
621 {
622 return skb_shinfo(skb)->gso_segs;
623 }
624
625 /* This is valid iff tcp_skb_pcount() > 1. */
626 static inline int tcp_skb_mss(const struct sk_buff *skb)
627 {
628 return skb_shinfo(skb)->gso_size;
629 }
630
631 /* Events passed to congestion control interface */
632 enum tcp_ca_event {
633 CA_EVENT_TX_START, /* first transmit when no packets in flight */
634 CA_EVENT_CWND_RESTART, /* congestion window restart */
635 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
636 CA_EVENT_FRTO, /* fast recovery timeout */
637 CA_EVENT_LOSS, /* loss timeout */
638 CA_EVENT_FAST_ACK, /* in sequence ack */
639 CA_EVENT_SLOW_ACK, /* other ack */
640 };
641
642 /*
643 * Interface for adding new TCP congestion control handlers
644 */
645 #define TCP_CA_NAME_MAX 16
646 #define TCP_CA_MAX 128
647 #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX)
648
649 #define TCP_CONG_NON_RESTRICTED 0x1
650 #define TCP_CONG_RTT_STAMP 0x2
651
652 struct tcp_congestion_ops {
653 struct list_head list;
654 unsigned long flags;
655
656 /* initialize private data (optional) */
657 void (*init)(struct sock *sk);
658 /* cleanup private data (optional) */
659 void (*release)(struct sock *sk);
660
661 /* return slow start threshold (required) */
662 u32 (*ssthresh)(struct sock *sk);
663 /* lower bound for congestion window (optional) */
664 u32 (*min_cwnd)(const struct sock *sk);
665 /* do new cwnd calculation (required) */
666 void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight);
667 /* call before changing ca_state (optional) */
668 void (*set_state)(struct sock *sk, u8 new_state);
669 /* call when cwnd event occurs (optional) */
670 void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
671 /* new value of cwnd after loss (optional) */
672 u32 (*undo_cwnd)(struct sock *sk);
673 /* hook for packet ack accounting (optional) */
674 void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us);
675 /* get info for inet_diag (optional) */
676 void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb);
677
678 char name[TCP_CA_NAME_MAX];
679 struct module *owner;
680 };
681
682 extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
683 extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
684
685 extern void tcp_init_congestion_control(struct sock *sk);
686 extern void tcp_cleanup_congestion_control(struct sock *sk);
687 extern int tcp_set_default_congestion_control(const char *name);
688 extern void tcp_get_default_congestion_control(char *name);
689 extern void tcp_get_available_congestion_control(char *buf, size_t len);
690 extern void tcp_get_allowed_congestion_control(char *buf, size_t len);
691 extern int tcp_set_allowed_congestion_control(char *allowed);
692 extern int tcp_set_congestion_control(struct sock *sk, const char *name);
693 extern void tcp_slow_start(struct tcp_sock *tp);
694 extern void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w);
695
696 extern struct tcp_congestion_ops tcp_init_congestion_ops;
697 extern u32 tcp_reno_ssthresh(struct sock *sk);
698 extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight);
699 extern u32 tcp_reno_min_cwnd(const struct sock *sk);
700 extern struct tcp_congestion_ops tcp_reno;
701
702 static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state)
703 {
704 struct inet_connection_sock *icsk = inet_csk(sk);
705
706 if (icsk->icsk_ca_ops->set_state)
707 icsk->icsk_ca_ops->set_state(sk, ca_state);
708 icsk->icsk_ca_state = ca_state;
709 }
710
711 static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event)
712 {
713 const struct inet_connection_sock *icsk = inet_csk(sk);
714
715 if (icsk->icsk_ca_ops->cwnd_event)
716 icsk->icsk_ca_ops->cwnd_event(sk, event);
717 }
718
719 /* These functions determine how the current flow behaves in respect of SACK
720 * handling. SACK is negotiated with the peer, and therefore it can vary
721 * between different flows.
722 *
723 * tcp_is_sack - SACK enabled
724 * tcp_is_reno - No SACK
725 * tcp_is_fack - FACK enabled, implies SACK enabled
726 */
727 static inline int tcp_is_sack(const struct tcp_sock *tp)
728 {
729 return tp->rx_opt.sack_ok;
730 }
731
732 static inline int tcp_is_reno(const struct tcp_sock *tp)
733 {
734 return !tcp_is_sack(tp);
735 }
736
737 static inline int tcp_is_fack(const struct tcp_sock *tp)
738 {
739 return tp->rx_opt.sack_ok & 2;
740 }
741
742 static inline void tcp_enable_fack(struct tcp_sock *tp)
743 {
744 tp->rx_opt.sack_ok |= 2;
745 }
746
747 static inline unsigned int tcp_left_out(const struct tcp_sock *tp)
748 {
749 return tp->sacked_out + tp->lost_out;
750 }
751
752 /* This determines how many packets are "in the network" to the best
753 * of our knowledge. In many cases it is conservative, but where
754 * detailed information is available from the receiver (via SACK
755 * blocks etc.) we can make more aggressive calculations.
756 *
757 * Use this for decisions involving congestion control, use just
758 * tp->packets_out to determine if the send queue is empty or not.
759 *
760 * Read this equation as:
761 *
762 * "Packets sent once on transmission queue" MINUS
763 * "Packets left network, but not honestly ACKed yet" PLUS
764 * "Packets fast retransmitted"
765 */
766 static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
767 {
768 return tp->packets_out - tcp_left_out(tp) + tp->retrans_out;
769 }
770
771 /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
772 * The exception is rate halving phase, when cwnd is decreasing towards
773 * ssthresh.
774 */
775 static inline __u32 tcp_current_ssthresh(const struct sock *sk)
776 {
777 const struct tcp_sock *tp = tcp_sk(sk);
778 if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery))
779 return tp->snd_ssthresh;
780 else
781 return max(tp->snd_ssthresh,
782 ((tp->snd_cwnd >> 1) +
783 (tp->snd_cwnd >> 2)));
784 }
785
786 /* Use define here intentionally to get WARN_ON location shown at the caller */
787 #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out)
788
789 extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh);
790 extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst);
791
792 /* Slow start with delack produces 3 packets of burst, so that
793 * it is safe "de facto". This will be the default - same as
794 * the default reordering threshold - but if reordering increases,
795 * we must be able to allow cwnd to burst at least this much in order
796 * to not pull it back when holes are filled.
797 */
798 static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
799 {
800 return tp->reordering;
801 }
802
803 /* Returns end sequence number of the receiver's advertised window */
804 static inline u32 tcp_wnd_end(const struct tcp_sock *tp)
805 {
806 return tp->snd_una + tp->snd_wnd;
807 }
808 extern int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight);
809
810 static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss,
811 const struct sk_buff *skb)
812 {
813 if (skb->len < mss)
814 tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
815 }
816
817 static inline void tcp_check_probe_timer(struct sock *sk)
818 {
819 struct tcp_sock *tp = tcp_sk(sk);
820 const struct inet_connection_sock *icsk = inet_csk(sk);
821
822 if (!tp->packets_out && !icsk->icsk_pending)
823 inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
824 icsk->icsk_rto, TCP_RTO_MAX);
825 }
826
827 static inline void tcp_push_pending_frames(struct sock *sk)
828 {
829 struct tcp_sock *tp = tcp_sk(sk);
830
831 __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle);
832 }
833
834 static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq)
835 {
836 tp->snd_wl1 = seq;
837 }
838
839 static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq)
840 {
841 tp->snd_wl1 = seq;
842 }
843
844 /*
845 * Calculate(/check) TCP checksum
846 */
847 static inline __sum16 tcp_v4_check(int len, __be32 saddr,
848 __be32 daddr, __wsum base)
849 {
850 return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base);
851 }
852
853 static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb)
854 {
855 return __skb_checksum_complete(skb);
856 }
857
858 static inline int tcp_checksum_complete(struct sk_buff *skb)
859 {
860 return !skb_csum_unnecessary(skb) &&
861 __tcp_checksum_complete(skb);
862 }
863
864 /* Prequeue for VJ style copy to user, combined with checksumming. */
865
866 static inline void tcp_prequeue_init(struct tcp_sock *tp)
867 {
868 tp->ucopy.task = NULL;
869 tp->ucopy.len = 0;
870 tp->ucopy.memory = 0;
871 skb_queue_head_init(&tp->ucopy.prequeue);
872 #ifdef CONFIG_NET_DMA
873 tp->ucopy.dma_chan = NULL;
874 tp->ucopy.wakeup = 0;
875 tp->ucopy.pinned_list = NULL;
876 tp->ucopy.dma_cookie = 0;
877 #endif
878 }
879
880 /* Packet is added to VJ-style prequeue for processing in process
881 * context, if a reader task is waiting. Apparently, this exciting
882 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
883 * failed somewhere. Latency? Burstiness? Well, at least now we will
884 * see, why it failed. 8)8) --ANK
885 *
886 * NOTE: is this not too big to inline?
887 */
888 static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb)
889 {
890 struct tcp_sock *tp = tcp_sk(sk);
891
892 if (!sysctl_tcp_low_latency && tp->ucopy.task) {
893 __skb_queue_tail(&tp->ucopy.prequeue, skb);
894 tp->ucopy.memory += skb->truesize;
895 if (tp->ucopy.memory > sk->sk_rcvbuf) {
896 struct sk_buff *skb1;
897
898 BUG_ON(sock_owned_by_user(sk));
899
900 while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) {
901 sk_backlog_rcv(sk, skb1);
902 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPPREQUEUEDROPPED);
903 }
904
905 tp->ucopy.memory = 0;
906 } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
907 wake_up_interruptible(sk->sk_sleep);
908 if (!inet_csk_ack_scheduled(sk))
909 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
910 (3 * tcp_rto_min(sk)) / 4,
911 TCP_RTO_MAX);
912 }
913 return 1;
914 }
915 return 0;
916 }
917
918
919 #undef STATE_TRACE
920
921 #ifdef STATE_TRACE
922 static const char *statename[]={
923 "Unused","Established","Syn Sent","Syn Recv",
924 "Fin Wait 1","Fin Wait 2","Time Wait", "Close",
925 "Close Wait","Last ACK","Listen","Closing"
926 };
927 #endif
928 extern void tcp_set_state(struct sock *sk, int state);
929
930 extern void tcp_done(struct sock *sk);
931
932 static inline void tcp_sack_reset(struct tcp_options_received *rx_opt)
933 {
934 rx_opt->dsack = 0;
935 rx_opt->num_sacks = 0;
936 }
937
938 /* Determine a window scaling and initial window to offer. */
939 extern void tcp_select_initial_window(int __space, __u32 mss,
940 __u32 *rcv_wnd, __u32 *window_clamp,
941 int wscale_ok, __u8 *rcv_wscale);
942
943 static inline int tcp_win_from_space(int space)
944 {
945 return sysctl_tcp_adv_win_scale<=0 ?
946 (space>>(-sysctl_tcp_adv_win_scale)) :
947 space - (space>>sysctl_tcp_adv_win_scale);
948 }
949
950 /* Note: caller must be prepared to deal with negative returns */
951 static inline int tcp_space(const struct sock *sk)
952 {
953 return tcp_win_from_space(sk->sk_rcvbuf -
954 atomic_read(&sk->sk_rmem_alloc));
955 }
956
957 static inline int tcp_full_space(const struct sock *sk)
958 {
959 return tcp_win_from_space(sk->sk_rcvbuf);
960 }
961
962 static inline void tcp_openreq_init(struct request_sock *req,
963 struct tcp_options_received *rx_opt,
964 struct sk_buff *skb)
965 {
966 struct inet_request_sock *ireq = inet_rsk(req);
967
968 req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */
969 req->cookie_ts = 0;
970 tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
971 req->mss = rx_opt->mss_clamp;
972 req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
973 ireq->tstamp_ok = rx_opt->tstamp_ok;
974 ireq->sack_ok = rx_opt->sack_ok;
975 ireq->snd_wscale = rx_opt->snd_wscale;
976 ireq->wscale_ok = rx_opt->wscale_ok;
977 ireq->acked = 0;
978 ireq->ecn_ok = 0;
979 ireq->rmt_port = tcp_hdr(skb)->source;
980 ireq->loc_port = tcp_hdr(skb)->dest;
981 }
982
983 extern void tcp_enter_memory_pressure(struct sock *sk);
984
985 static inline int keepalive_intvl_when(const struct tcp_sock *tp)
986 {
987 return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl;
988 }
989
990 static inline int keepalive_time_when(const struct tcp_sock *tp)
991 {
992 return tp->keepalive_time ? : sysctl_tcp_keepalive_time;
993 }
994
995 static inline int tcp_fin_time(const struct sock *sk)
996 {
997 int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout;
998 const int rto = inet_csk(sk)->icsk_rto;
999
1000 if (fin_timeout < (rto << 2) - (rto >> 1))
1001 fin_timeout = (rto << 2) - (rto >> 1);
1002
1003 return fin_timeout;
1004 }
1005
1006 static inline int tcp_paws_check(const struct tcp_options_received *rx_opt,
1007 int paws_win)
1008 {
1009 if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win)
1010 return 1;
1011 if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS))
1012 return 1;
1013
1014 return 0;
1015 }
1016
1017 static inline int tcp_paws_reject(const struct tcp_options_received *rx_opt,
1018 int rst)
1019 {
1020 if (tcp_paws_check(rx_opt, 0))
1021 return 0;
1022
1023 /* RST segments are not recommended to carry timestamp,
1024 and, if they do, it is recommended to ignore PAWS because
1025 "their cleanup function should take precedence over timestamps."
1026 Certainly, it is mistake. It is necessary to understand the reasons
1027 of this constraint to relax it: if peer reboots, clock may go
1028 out-of-sync and half-open connections will not be reset.
1029 Actually, the problem would be not existing if all
1030 the implementations followed draft about maintaining clock
1031 via reboots. Linux-2.2 DOES NOT!
1032
1033 However, we can relax time bounds for RST segments to MSL.
1034 */
1035 if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
1036 return 0;
1037 return 1;
1038 }
1039
1040 #define TCP_CHECK_TIMER(sk) do { } while (0)
1041
1042 static inline void tcp_mib_init(struct net *net)
1043 {
1044 /* See RFC 2012 */
1045 TCP_ADD_STATS_USER(net, TCP_MIB_RTOALGORITHM, 1);
1046 TCP_ADD_STATS_USER(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ);
1047 TCP_ADD_STATS_USER(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ);
1048 TCP_ADD_STATS_USER(net, TCP_MIB_MAXCONN, -1);
1049 }
1050
1051 /* from STCP */
1052 static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp)
1053 {
1054 tp->lost_skb_hint = NULL;
1055 tp->scoreboard_skb_hint = NULL;
1056 }
1057
1058 static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp)
1059 {
1060 tcp_clear_retrans_hints_partial(tp);
1061 tp->retransmit_skb_hint = NULL;
1062 }
1063
1064 /* MD5 Signature */
1065 struct crypto_hash;
1066
1067 /* - key database */
1068 struct tcp_md5sig_key {
1069 u8 *key;
1070 u8 keylen;
1071 };
1072
1073 struct tcp4_md5sig_key {
1074 struct tcp_md5sig_key base;
1075 __be32 addr;
1076 };
1077
1078 struct tcp6_md5sig_key {
1079 struct tcp_md5sig_key base;
1080 #if 0
1081 u32 scope_id; /* XXX */
1082 #endif
1083 struct in6_addr addr;
1084 };
1085
1086 /* - sock block */
1087 struct tcp_md5sig_info {
1088 struct tcp4_md5sig_key *keys4;
1089 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1090 struct tcp6_md5sig_key *keys6;
1091 u32 entries6;
1092 u32 alloced6;
1093 #endif
1094 u32 entries4;
1095 u32 alloced4;
1096 };
1097
1098 /* - pseudo header */
1099 struct tcp4_pseudohdr {
1100 __be32 saddr;
1101 __be32 daddr;
1102 __u8 pad;
1103 __u8 protocol;
1104 __be16 len;
1105 };
1106
1107 struct tcp6_pseudohdr {
1108 struct in6_addr saddr;
1109 struct in6_addr daddr;
1110 __be32 len;
1111 __be32 protocol; /* including padding */
1112 };
1113
1114 union tcp_md5sum_block {
1115 struct tcp4_pseudohdr ip4;
1116 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1117 struct tcp6_pseudohdr ip6;
1118 #endif
1119 };
1120
1121 /* - pool: digest algorithm, hash description and scratch buffer */
1122 struct tcp_md5sig_pool {
1123 struct hash_desc md5_desc;
1124 union tcp_md5sum_block md5_blk;
1125 };
1126
1127 #define TCP_MD5SIG_MAXKEYS (~(u32)0) /* really?! */
1128
1129 /* - functions */
1130 extern int tcp_v4_md5_hash_skb(char *md5_hash,
1131 struct tcp_md5sig_key *key,
1132 struct sock *sk,
1133 struct request_sock *req,
1134 struct sk_buff *skb);
1135
1136 extern struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
1137 struct sock *addr_sk);
1138
1139 extern int tcp_v4_md5_do_add(struct sock *sk,
1140 __be32 addr,
1141 u8 *newkey,
1142 u8 newkeylen);
1143
1144 extern int tcp_v4_md5_do_del(struct sock *sk,
1145 __be32 addr);
1146
1147 #ifdef CONFIG_TCP_MD5SIG
1148 #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_keylen ? \
1149 &(struct tcp_md5sig_key) { \
1150 .key = (twsk)->tw_md5_key, \
1151 .keylen = (twsk)->tw_md5_keylen, \
1152 } : NULL)
1153 #else
1154 #define tcp_twsk_md5_key(twsk) NULL
1155 #endif
1156
1157 extern struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void);
1158 extern void tcp_free_md5sig_pool(void);
1159
1160 extern struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu);
1161 extern void __tcp_put_md5sig_pool(void);
1162 extern int tcp_md5_hash_header(struct tcp_md5sig_pool *, struct tcphdr *);
1163 extern int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, struct sk_buff *,
1164 unsigned header_len);
1165 extern int tcp_md5_hash_key(struct tcp_md5sig_pool *hp,
1166 struct tcp_md5sig_key *key);
1167
1168 static inline
1169 struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
1170 {
1171 int cpu = get_cpu();
1172 struct tcp_md5sig_pool *ret = __tcp_get_md5sig_pool(cpu);
1173 if (!ret)
1174 put_cpu();
1175 return ret;
1176 }
1177
1178 static inline void tcp_put_md5sig_pool(void)
1179 {
1180 __tcp_put_md5sig_pool();
1181 put_cpu();
1182 }
1183
1184 /* write queue abstraction */
1185 static inline void tcp_write_queue_purge(struct sock *sk)
1186 {
1187 struct sk_buff *skb;
1188
1189 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
1190 sk_wmem_free_skb(sk, skb);
1191 sk_mem_reclaim(sk);
1192 }
1193
1194 static inline struct sk_buff *tcp_write_queue_head(struct sock *sk)
1195 {
1196 return skb_peek(&sk->sk_write_queue);
1197 }
1198
1199 static inline struct sk_buff *tcp_write_queue_tail(struct sock *sk)
1200 {
1201 return skb_peek_tail(&sk->sk_write_queue);
1202 }
1203
1204 static inline struct sk_buff *tcp_write_queue_next(struct sock *sk, struct sk_buff *skb)
1205 {
1206 return skb_queue_next(&sk->sk_write_queue, skb);
1207 }
1208
1209 static inline struct sk_buff *tcp_write_queue_prev(struct sock *sk, struct sk_buff *skb)
1210 {
1211 return skb_queue_prev(&sk->sk_write_queue, skb);
1212 }
1213
1214 #define tcp_for_write_queue(skb, sk) \
1215 skb_queue_walk(&(sk)->sk_write_queue, skb)
1216
1217 #define tcp_for_write_queue_from(skb, sk) \
1218 skb_queue_walk_from(&(sk)->sk_write_queue, skb)
1219
1220 #define tcp_for_write_queue_from_safe(skb, tmp, sk) \
1221 skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp)
1222
1223 static inline struct sk_buff *tcp_send_head(struct sock *sk)
1224 {
1225 return sk->sk_send_head;
1226 }
1227
1228 static inline bool tcp_skb_is_last(const struct sock *sk,
1229 const struct sk_buff *skb)
1230 {
1231 return skb_queue_is_last(&sk->sk_write_queue, skb);
1232 }
1233
1234 static inline void tcp_advance_send_head(struct sock *sk, struct sk_buff *skb)
1235 {
1236 if (tcp_skb_is_last(sk, skb))
1237 sk->sk_send_head = NULL;
1238 else
1239 sk->sk_send_head = tcp_write_queue_next(sk, skb);
1240 }
1241
1242 static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked)
1243 {
1244 if (sk->sk_send_head == skb_unlinked)
1245 sk->sk_send_head = NULL;
1246 }
1247
1248 static inline void tcp_init_send_head(struct sock *sk)
1249 {
1250 sk->sk_send_head = NULL;
1251 }
1252
1253 static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
1254 {
1255 __skb_queue_tail(&sk->sk_write_queue, skb);
1256 }
1257
1258 static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
1259 {
1260 __tcp_add_write_queue_tail(sk, skb);
1261
1262 /* Queue it, remembering where we must start sending. */
1263 if (sk->sk_send_head == NULL) {
1264 sk->sk_send_head = skb;
1265
1266 if (tcp_sk(sk)->highest_sack == NULL)
1267 tcp_sk(sk)->highest_sack = skb;
1268 }
1269 }
1270
1271 static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb)
1272 {
1273 __skb_queue_head(&sk->sk_write_queue, skb);
1274 }
1275
1276 /* Insert buff after skb on the write queue of sk. */
1277 static inline void tcp_insert_write_queue_after(struct sk_buff *skb,
1278 struct sk_buff *buff,
1279 struct sock *sk)
1280 {
1281 __skb_queue_after(&sk->sk_write_queue, skb, buff);
1282 }
1283
1284 /* Insert new before skb on the write queue of sk. */
1285 static inline void tcp_insert_write_queue_before(struct sk_buff *new,
1286 struct sk_buff *skb,
1287 struct sock *sk)
1288 {
1289 __skb_queue_before(&sk->sk_write_queue, skb, new);
1290
1291 if (sk->sk_send_head == skb)
1292 sk->sk_send_head = new;
1293 }
1294
1295 static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk)
1296 {
1297 __skb_unlink(skb, &sk->sk_write_queue);
1298 }
1299
1300 static inline int tcp_write_queue_empty(struct sock *sk)
1301 {
1302 return skb_queue_empty(&sk->sk_write_queue);
1303 }
1304
1305 /* Start sequence of the highest skb with SACKed bit, valid only if
1306 * sacked > 0 or when the caller has ensured validity by itself.
1307 */
1308 static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp)
1309 {
1310 if (!tp->sacked_out)
1311 return tp->snd_una;
1312
1313 if (tp->highest_sack == NULL)
1314 return tp->snd_nxt;
1315
1316 return TCP_SKB_CB(tp->highest_sack)->seq;
1317 }
1318
1319 static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb)
1320 {
1321 tcp_sk(sk)->highest_sack = tcp_skb_is_last(sk, skb) ? NULL :
1322 tcp_write_queue_next(sk, skb);
1323 }
1324
1325 static inline struct sk_buff *tcp_highest_sack(struct sock *sk)
1326 {
1327 return tcp_sk(sk)->highest_sack;
1328 }
1329
1330 static inline void tcp_highest_sack_reset(struct sock *sk)
1331 {
1332 tcp_sk(sk)->highest_sack = tcp_write_queue_head(sk);
1333 }
1334
1335 /* Called when old skb is about to be deleted (to be combined with new skb) */
1336 static inline void tcp_highest_sack_combine(struct sock *sk,
1337 struct sk_buff *old,
1338 struct sk_buff *new)
1339 {
1340 if (tcp_sk(sk)->sacked_out && (old == tcp_sk(sk)->highest_sack))
1341 tcp_sk(sk)->highest_sack = new;
1342 }
1343
1344 /* /proc */
1345 enum tcp_seq_states {
1346 TCP_SEQ_STATE_LISTENING,
1347 TCP_SEQ_STATE_OPENREQ,
1348 TCP_SEQ_STATE_ESTABLISHED,
1349 TCP_SEQ_STATE_TIME_WAIT,
1350 };
1351
1352 struct tcp_seq_afinfo {
1353 char *name;
1354 sa_family_t family;
1355 struct file_operations seq_fops;
1356 struct seq_operations seq_ops;
1357 };
1358
1359 struct tcp_iter_state {
1360 struct seq_net_private p;
1361 sa_family_t family;
1362 enum tcp_seq_states state;
1363 struct sock *syn_wait_sk;
1364 int bucket, sbucket, num, uid;
1365 };
1366
1367 extern int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo);
1368 extern void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo);
1369
1370 extern struct request_sock_ops tcp_request_sock_ops;
1371 extern struct request_sock_ops tcp6_request_sock_ops;
1372
1373 extern void tcp_v4_destroy_sock(struct sock *sk);
1374
1375 extern int tcp_v4_gso_send_check(struct sk_buff *skb);
1376 extern struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features);
1377 extern struct sk_buff **tcp_gro_receive(struct sk_buff **head,
1378 struct sk_buff *skb);
1379 extern struct sk_buff **tcp4_gro_receive(struct sk_buff **head,
1380 struct sk_buff *skb);
1381 extern int tcp_gro_complete(struct sk_buff *skb);
1382 extern int tcp4_gro_complete(struct sk_buff *skb);
1383
1384 #ifdef CONFIG_PROC_FS
1385 extern int tcp4_proc_init(void);
1386 extern void tcp4_proc_exit(void);
1387 #endif
1388
1389 /* TCP af-specific functions */
1390 struct tcp_sock_af_ops {
1391 #ifdef CONFIG_TCP_MD5SIG
1392 struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
1393 struct sock *addr_sk);
1394 int (*calc_md5_hash) (char *location,
1395 struct tcp_md5sig_key *md5,
1396 struct sock *sk,
1397 struct request_sock *req,
1398 struct sk_buff *skb);
1399 int (*md5_add) (struct sock *sk,
1400 struct sock *addr_sk,
1401 u8 *newkey,
1402 u8 len);
1403 int (*md5_parse) (struct sock *sk,
1404 char __user *optval,
1405 int optlen);
1406 #endif
1407 };
1408
1409 struct tcp_request_sock_ops {
1410 #ifdef CONFIG_TCP_MD5SIG
1411 struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
1412 struct request_sock *req);
1413 #endif
1414 };
1415
1416 extern void tcp_v4_init(void);
1417 extern void tcp_init(void);
1418
1419 #endif /* _TCP_H */
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree