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[NET]: include/linux/udp.h - remove duplicate include
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / net / tcp.h
CommitLineData
1da177e4
LT		 1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Definitions for the TCP module.
7 *
8 * Version: @(#)tcp.h 1.0.5 05/23/93
9 *
02c30a84 10 * Authors: Ross Biro
1da177e4
LT		 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
17 */
18#ifndef _TCP_H
19#define _TCP_H
20
21#define TCP_DEBUG 1
22#define FASTRETRANS_DEBUG 1
23
1da177e4
LT		 24#include <linux/list.h>
25#include <linux/tcp.h>
26#include <linux/slab.h>
27#include <linux/cache.h>
28#include <linux/percpu.h>
fb286bb2 29#include <linux/skbuff.h>
97fc2f08 30#include <linux/dmaengine.h>
cfb6eeb4 31#include <linux/crypto.h>
c6aefafb 32#include <linux/cryptohash.h>
3f421baa
ACM		 33
34#include <net/inet_connection_sock.h>
295ff7ed 35#include <net/inet_timewait_sock.h>
77d8bf9c 36#include <net/inet_hashtables.h>
1da177e4 37#include <net/checksum.h>
2e6599cb 38#include <net/request_sock.h>
1da177e4
LT		 39#include <net/sock.h>
40#include <net/snmp.h>
41#include <net/ip.h>
c752f073 42#include <net/tcp_states.h>
bdf1ee5d 43#include <net/inet_ecn.h>
c752f073 44
1da177e4
LT		 45#include <linux/seq_file.h>
46
6e04e021 47extern struct inet_hashinfo tcp_hashinfo;
1da177e4 48
1da177e4 49extern atomic_t tcp_orphan_count;
1da177e4 50extern void tcp_time_wait(struct sock *sk, int state, int timeo);
1da177e4 51
1da177e4
LT		 52#define MAX_TCP_HEADER (128 + MAX_HEADER)
53
54/*
55 * Never offer a window over 32767 without using window scaling. Some
56 * poor stacks do signed 16bit maths!
57 */
58#define MAX_TCP_WINDOW 32767U
59
60/* Minimal accepted MSS. It is (60+60+8) - (20+20). */
61#define TCP_MIN_MSS 88U
62
63/* Minimal RCV_MSS. */
64#define TCP_MIN_RCVMSS 536U
65
5d424d5a
JH		 66/* The least MTU to use for probing */
67#define TCP_BASE_MSS 512
68
1da177e4
LT		 69/* After receiving this amount of duplicate ACKs fast retransmit starts. */
70#define TCP_FASTRETRANS_THRESH 3
71
72/* Maximal reordering. */
73#define TCP_MAX_REORDERING 127
74
75/* Maximal number of ACKs sent quickly to accelerate slow-start. */
76#define TCP_MAX_QUICKACKS 16U
77
78/* urg_data states */
79#define TCP_URG_VALID 0x0100
80#define TCP_URG_NOTYET 0x0200
81#define TCP_URG_READ 0x0400
82
83#define TCP_RETR1 3 /*
84 * This is how many retries it does before it
85 * tries to figure out if the gateway is
86 * down. Minimal RFC value is 3; it corresponds
87 * to ~3sec-8min depending on RTO.
88 */
89
90#define TCP_RETR2 15 /*
91 * This should take at least
92 * 90 minutes to time out.
93 * RFC1122 says that the limit is 100 sec.
94 * 15 is ~13-30min depending on RTO.
95 */
96
97#define TCP_SYN_RETRIES 5 /* number of times to retry active opening a
caa20d9a 98 * connection: ~180sec is RFC minimum */
1da177e4
LT		 99
100#define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a
caa20d9a 101 * connection: ~180sec is RFC minimum */
1da177e4
LT		 102
103
104#define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned
105 * socket. 7 is ~50sec-16min.
106 */
107
108
109#define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT
110 * state, about 60 seconds */
111#define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN
112 /* BSD style FIN_WAIT2 deadlock breaker.
113 * It used to be 3min, new value is 60sec,
114 * to combine FIN-WAIT-2 timeout with
115 * TIME-WAIT timer.
116 */
117
118#define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */
119#if HZ >= 100
120#define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */
121#define TCP_ATO_MIN ((unsigned)(HZ/25))
122#else
123#define TCP_DELACK_MIN 4U
124#define TCP_ATO_MIN 4U
125#endif
126#define TCP_RTO_MAX ((unsigned)(120*HZ))
127#define TCP_RTO_MIN ((unsigned)(HZ/5))
128#define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */
129
130#define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
131 * for local resources.
132 */
133
134#define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */
135#define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */
136#define TCP_KEEPALIVE_INTVL (75*HZ)
137
138#define MAX_TCP_KEEPIDLE 32767
139#define MAX_TCP_KEEPINTVL 32767
140#define MAX_TCP_KEEPCNT 127
141#define MAX_TCP_SYNCNT 127
ec3c0982 142#define MAX_TCP_ACCEPT_DEFERRED 65535
1da177e4
LT		 143
144#define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */
1da177e4
LT		 145
146#define TCP_PAWS_24DAYS (60 * 60 * 24 * 24)
147#define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated
148 * after this time. It should be equal
149 * (or greater than) TCP_TIMEWAIT_LEN
150 * to provide reliability equal to one
151 * provided by timewait state.
152 */
153#define TCP_PAWS_WINDOW 1 /* Replay window for per-host
154 * timestamps. It must be less than
155 * minimal timewait lifetime.
156 */
1da177e4
LT		 157/*
158 * TCP option
159 */
160
161#define TCPOPT_NOP 1 /* Padding */
162#define TCPOPT_EOL 0 /* End of options */
163#define TCPOPT_MSS 2 /* Segment size negotiating */
164#define TCPOPT_WINDOW 3 /* Window scaling */
165#define TCPOPT_SACK_PERM 4 /* SACK Permitted */
166#define TCPOPT_SACK 5 /* SACK Block */
167#define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
cfb6eeb4 168#define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */
1da177e4
LT		 169
170/*
171 * TCP option lengths
172 */
173
174#define TCPOLEN_MSS 4
175#define TCPOLEN_WINDOW 3
176#define TCPOLEN_SACK_PERM 2
177#define TCPOLEN_TIMESTAMP 10
cfb6eeb4 178#define TCPOLEN_MD5SIG 18
1da177e4
LT		 179
180/* But this is what stacks really send out. */
181#define TCPOLEN_TSTAMP_ALIGNED 12
182#define TCPOLEN_WSCALE_ALIGNED 4
183#define TCPOLEN_SACKPERM_ALIGNED 4
184#define TCPOLEN_SACK_BASE 2
185#define TCPOLEN_SACK_BASE_ALIGNED 4
186#define TCPOLEN_SACK_PERBLOCK 8
cfb6eeb4 187#define TCPOLEN_MD5SIG_ALIGNED 20
1da177e4 188
1da177e4
LT		 189/* Flags in tp->nonagle */
190#define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
191#define TCP_NAGLE_CORK 2 /* Socket is corked */
caa20d9a 192#define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */
1da177e4 193
295ff7ed
ACM		 194extern struct inet_timewait_death_row tcp_death_row;
195
1da177e4 196/* sysctl variables for tcp */
1da177e4
LT		 197extern int sysctl_tcp_timestamps;
198extern int sysctl_tcp_window_scaling;
199extern int sysctl_tcp_sack;
200extern int sysctl_tcp_fin_timeout;
1da177e4
LT		 201extern int sysctl_tcp_keepalive_time;
202extern int sysctl_tcp_keepalive_probes;
203extern int sysctl_tcp_keepalive_intvl;
204extern int sysctl_tcp_syn_retries;
205extern int sysctl_tcp_synack_retries;
206extern int sysctl_tcp_retries1;
207extern int sysctl_tcp_retries2;
208extern int sysctl_tcp_orphan_retries;
209extern int sysctl_tcp_syncookies;
210extern int sysctl_tcp_retrans_collapse;
211extern int sysctl_tcp_stdurg;
212extern int sysctl_tcp_rfc1337;
213extern int sysctl_tcp_abort_on_overflow;
214extern int sysctl_tcp_max_orphans;
1da177e4
LT		 215extern int sysctl_tcp_fack;
216extern int sysctl_tcp_reordering;
217extern int sysctl_tcp_ecn;
218extern int sysctl_tcp_dsack;
219extern int sysctl_tcp_mem[3];
220extern int sysctl_tcp_wmem[3];
221extern int sysctl_tcp_rmem[3];
222extern int sysctl_tcp_app_win;
223extern int sysctl_tcp_adv_win_scale;
224extern int sysctl_tcp_tw_reuse;
225extern int sysctl_tcp_frto;
3cfe3baa 226extern int sysctl_tcp_frto_response;
1da177e4 227extern int sysctl_tcp_low_latency;
95937825 228extern int sysctl_tcp_dma_copybreak;
1da177e4 229extern int sysctl_tcp_nometrics_save;
1da177e4
LT		 230extern int sysctl_tcp_moderate_rcvbuf;
231extern int sysctl_tcp_tso_win_divisor;
9772efb9 232extern int sysctl_tcp_abc;
5d424d5a
JH		 233extern int sysctl_tcp_mtu_probing;
234extern int sysctl_tcp_base_mss;
15d99e02 235extern int sysctl_tcp_workaround_signed_windows;
35089bb2 236extern int sysctl_tcp_slow_start_after_idle;
886236c1 237extern int sysctl_tcp_max_ssthresh;
1da177e4
LT		 238
239extern atomic_t tcp_memory_allocated;
240extern atomic_t tcp_sockets_allocated;
241extern int tcp_memory_pressure;
242
1da177e4
LT		 243/*
244 * The next routines deal with comparing 32 bit unsigned ints
245 * and worry about wraparound (automatic with unsigned arithmetic).
246 */
247
248static inline int before(__u32 seq1, __u32 seq2)
249{
0d630cc0 250 return (__s32)(seq1-seq2) < 0;
1da177e4 251}
9a036b9c 252#define after(seq2, seq1) before(seq1, seq2)
1da177e4
LT		 253
254/* is s2<=s1<=s3 ? */
255static inline int between(__u32 seq1, __u32 seq2, __u32 seq3)
256{
257 return seq3 - seq2 >= seq1 - seq2;
258}
259
e4fd5da3
PE		 260static inline int tcp_too_many_orphans(struct sock *sk, int num)
261{
262 return (num > sysctl_tcp_max_orphans) ||
263 (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
264 atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2]);
265}
1da177e4
LT		 266
267extern struct proto tcp_prot;
268
269DECLARE_SNMP_STAT(struct tcp_mib, tcp_statistics);
270#define TCP_INC_STATS(field) SNMP_INC_STATS(tcp_statistics, field)
271#define TCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(tcp_statistics, field)
272#define TCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(tcp_statistics, field)
273#define TCP_DEC_STATS(field) SNMP_DEC_STATS(tcp_statistics, field)
274#define TCP_ADD_STATS_BH(field, val) SNMP_ADD_STATS_BH(tcp_statistics, field, val)
275#define TCP_ADD_STATS_USER(field, val) SNMP_ADD_STATS_USER(tcp_statistics, field, val)
276
1da177e4
LT		 277extern void tcp_v4_err(struct sk_buff *skb, u32);
278
279extern void tcp_shutdown (struct sock *sk, int how);
280
281extern int tcp_v4_rcv(struct sk_buff *skb);
282
283extern int tcp_v4_remember_stamp(struct sock *sk);
284
8feaf0c0 285extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
1da177e4 286
3516ffb0 287extern int tcp_sendmsg(struct kiocb *iocb, struct socket *sock,
1da177e4
LT		 288 struct msghdr *msg, size_t size);
289extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags);
290
291extern int tcp_ioctl(struct sock *sk,
292 int cmd,
293 unsigned long arg);
294
295extern int tcp_rcv_state_process(struct sock *sk,
296 struct sk_buff *skb,
297 struct tcphdr *th,
298 unsigned len);
299
300extern int tcp_rcv_established(struct sock *sk,
301 struct sk_buff *skb,
302 struct tcphdr *th,
303 unsigned len);
304
305extern void tcp_rcv_space_adjust(struct sock *sk);
306
0e4b4992
CL		 307extern void tcp_cleanup_rbuf(struct sock *sk, int copied);
308
6d6ee43e
ACM		 309extern int tcp_twsk_unique(struct sock *sk,
310 struct sock *sktw, void *twp);
311
cfb6eeb4
YH		 312extern void tcp_twsk_destructor(struct sock *sk);
313
9c55e01c
JA		 314extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos,
315 struct pipe_inode_info *pipe, size_t len, unsigned int flags);
316
463c84b9
ACM		 317static inline void tcp_dec_quickack_mode(struct sock *sk,
318 const unsigned int pkts)
1da177e4 319{
463c84b9 320 struct inet_connection_sock *icsk = inet_csk(sk);
fc6415bc 321
463c84b9
ACM		 322 if (icsk->icsk_ack.quick) {
323 if (pkts >= icsk->icsk_ack.quick) {
324 icsk->icsk_ack.quick = 0;
fc6415bc 325 /* Leaving quickack mode we deflate ATO. */
463c84b9 326 icsk->icsk_ack.ato = TCP_ATO_MIN;
fc6415bc 327 } else
463c84b9 328 icsk->icsk_ack.quick -= pkts;
1da177e4
LT		 329 }
330}
331
463c84b9 332extern void tcp_enter_quickack_mode(struct sock *sk);
1da177e4 333
1da177e4
LT		 334static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
335{
336 rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
337}
338
bdf1ee5d
IJ		 339#define TCP_ECN_OK 1
340#define TCP_ECN_QUEUE_CWR 2
341#define TCP_ECN_DEMAND_CWR 4
342
343static __inline__ void
344TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th)
345{
346 if (sysctl_tcp_ecn && th->ece && th->cwr)
347 inet_rsk(req)->ecn_ok = 1;
348}
349
1da177e4
LT		 350enum tcp_tw_status
351{
352 TCP_TW_SUCCESS = 0,
353 TCP_TW_RST = 1,
354 TCP_TW_ACK = 2,
355 TCP_TW_SYN = 3
356};
357
358
8feaf0c0 359extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw,
1da177e4 360 struct sk_buff *skb,
8feaf0c0 361 const struct tcphdr *th);
1da177e4
LT		 362
363extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb,
60236fdd
ACM		 364 struct request_sock *req,
365 struct request_sock **prev);
1da177e4
LT		 366extern int tcp_child_process(struct sock *parent,
367 struct sock *child,
368 struct sk_buff *skb);
46d0de4e 369extern int tcp_use_frto(struct sock *sk);
1da177e4
LT		 370extern void tcp_enter_frto(struct sock *sk);
371extern void tcp_enter_loss(struct sock *sk, int how);
372extern void tcp_clear_retrans(struct tcp_sock *tp);
373extern void tcp_update_metrics(struct sock *sk);
374
375extern void tcp_close(struct sock *sk,
376 long timeout);
1da177e4
LT		 377extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait);
378
379extern int tcp_getsockopt(struct sock *sk, int level,
380 int optname,
381 char __user *optval,
382 int __user *optlen);
383extern int tcp_setsockopt(struct sock *sk, int level,
384 int optname, char __user *optval,
385 int optlen);
3fdadf7d
DM		 386extern int compat_tcp_getsockopt(struct sock *sk,
387 int level, int optname,
388 char __user *optval, int __user *optlen);
389extern int compat_tcp_setsockopt(struct sock *sk,
390 int level, int optname,
391 char __user *optval, int optlen);
1da177e4
LT		 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
8292a17a 406extern void tcp_v4_send_check(struct sock *sk, int len,
1da177e4
LT		 407 struct sk_buff *skb);
408
409extern int tcp_v4_conn_request(struct sock *sk,
410 struct sk_buff *skb);
411
412extern struct sock * tcp_create_openreq_child(struct sock *sk,
60236fdd 413 struct request_sock *req,
1da177e4
LT		 414 struct sk_buff *skb);
415
416extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk,
417 struct sk_buff *skb,
60236fdd 418 struct request_sock *req,
1da177e4
LT		 419 struct dst_entry *dst);
420
421extern int tcp_v4_do_rcv(struct sock *sk,
422 struct sk_buff *skb);
423
424extern int tcp_v4_connect(struct sock *sk,
425 struct sockaddr *uaddr,
426 int addr_len);
427
428extern int tcp_connect(struct sock *sk);
429
430extern struct sk_buff * tcp_make_synack(struct sock *sk,
431 struct dst_entry *dst,
60236fdd 432 struct request_sock *req);
1da177e4
LT		 433
434extern int tcp_disconnect(struct sock *sk, int flags);
435
436extern void tcp_unhash(struct sock *sk);
437
1da177e4 438/* From syncookies.c */
c6aefafb 439extern __u32 syncookie_secret[2][16-3+SHA_DIGEST_WORDS];
1da177e4
LT		 440extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
441 struct ip_options *opt);
442extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
443 __u16 *mss);
444
c6aefafb
GG		 445/* From net/ipv6/syncookies.c */
446extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb);
447extern __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb,
448 __u16 *mss);
449
1da177e4
LT		 450/* tcp_output.c */
451
9e412ba7
IJ		 452extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
453 int nonagle);
454extern int tcp_may_send_now(struct sock *sk);
1da177e4
LT		 455extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);
456extern void tcp_xmit_retransmit_queue(struct sock *);
457extern void tcp_simple_retransmit(struct sock *);
458extern int tcp_trim_head(struct sock *, struct sk_buff *, u32);
6475be16 459extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int);
1da177e4
LT		 460
461extern void tcp_send_probe0(struct sock *);
462extern void tcp_send_partial(struct sock *);
463extern int tcp_write_wakeup(struct sock *);
464extern void tcp_send_fin(struct sock *sk);
dd0fc66f 465extern void tcp_send_active_reset(struct sock *sk, gfp_t priority);
1da177e4 466extern int tcp_send_synack(struct sock *);
c1b4a7e6 467extern void tcp_push_one(struct sock *, unsigned int mss_now);
1da177e4
LT		 468extern void tcp_send_ack(struct sock *sk);
469extern void tcp_send_delayed_ack(struct sock *sk);
470
a762a980
DM		 471/* tcp_input.c */
472extern void tcp_cwnd_application_limited(struct sock *sk);
473
1da177e4
LT		 474/* tcp_timer.c */
475extern void tcp_init_xmit_timers(struct sock *);
463c84b9
ACM		 476static inline void tcp_clear_xmit_timers(struct sock *sk)
477{
478 inet_csk_clear_xmit_timers(sk);
479}
1da177e4 480
1da177e4
LT		 481extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu);
482extern unsigned int tcp_current_mss(struct sock *sk, int large);
483
17b085ea 484/* tcp.c */
1da177e4
LT		 485extern void tcp_get_info(struct sock *, struct tcp_info *);
486
487/* Read 'sendfile()'-style from a TCP socket */
488typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
489 unsigned int, size_t);
490extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
491 sk_read_actor_t recv_actor);
492
40efc6fa 493extern void tcp_initialize_rcv_mss(struct sock *sk);
1da177e4 494
5d424d5a
JH		 495extern int tcp_mtu_to_mss(struct sock *sk, int pmtu);
496extern int tcp_mss_to_mtu(struct sock *sk, int mss);
497extern void tcp_mtup_init(struct sock *sk);
498
40efc6fa 499static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd)
1da177e4
LT		 500{
501 tp->pred_flags = htonl((tp->tcp_header_len << 26) |
502 ntohl(TCP_FLAG_ACK) |
503 snd_wnd);
504}
505
40efc6fa 506static inline void tcp_fast_path_on(struct tcp_sock *tp)
1da177e4
LT		 507{
508 __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale);
509}
510
9e412ba7 511static inline void tcp_fast_path_check(struct sock *sk)
1da177e4 512{
9e412ba7
IJ		 513 struct tcp_sock *tp = tcp_sk(sk);
514
b03efcfb 515 if (skb_queue_empty(&tp->out_of_order_queue) &&
1da177e4
LT		 516 tp->rcv_wnd &&
517 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
518 !tp->urg_data)
519 tcp_fast_path_on(tp);
520}
521
522/* Compute the actual receive window we are currently advertising.
523 * Rcv_nxt can be after the window if our peer push more data
524 * than the offered window.
525 */
40efc6fa 526static inline u32 tcp_receive_window(const struct tcp_sock *tp)
1da177e4
LT		 527{
528 s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt;
529
530 if (win < 0)
531 win = 0;
532 return (u32) win;
533}
534
535/* Choose a new window, without checks for shrinking, and without
536 * scaling applied to the result. The caller does these things
537 * if necessary. This is a "raw" window selection.
538 */
539extern u32 __tcp_select_window(struct sock *sk);
540
541/* TCP timestamps are only 32-bits, this causes a slight
542 * complication on 64-bit systems since we store a snapshot
31f34269
SH		 543 * of jiffies in the buffer control blocks below. We decided
544 * to use only the low 32-bits of jiffies and hide the ugly
1da177e4
LT		 545 * casts with the following macro.
546 */
547#define tcp_time_stamp ((__u32)(jiffies))
548
caa20d9a 549/* This is what the send packet queuing engine uses to pass
1da177e4
LT		 550 * TCP per-packet control information to the transmission
551 * code. We also store the host-order sequence numbers in
552 * here too. This is 36 bytes on 32-bit architectures,
553 * 40 bytes on 64-bit machines, if this grows please adjust
554 * skbuff.h:skbuff->cb[xxx] size appropriately.
555 */
556struct tcp_skb_cb {
557 union {
558 struct inet_skb_parm h4;
559#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
560 struct inet6_skb_parm h6;
561#endif
562 } header; /* For incoming frames */
563 __u32 seq; /* Starting sequence number */
564 __u32 end_seq; /* SEQ + FIN + SYN + datalen */
565 __u32 when; /* used to compute rtt's */
566 __u8 flags; /* TCP header flags. */
567
568 /* NOTE: These must match up to the flags byte in a
569 * real TCP header.
570 */
571#define TCPCB_FLAG_FIN 0x01
572#define TCPCB_FLAG_SYN 0x02
573#define TCPCB_FLAG_RST 0x04
574#define TCPCB_FLAG_PSH 0x08
575#define TCPCB_FLAG_ACK 0x10
576#define TCPCB_FLAG_URG 0x20
577#define TCPCB_FLAG_ECE 0x40
578#define TCPCB_FLAG_CWR 0x80
579
580 __u8 sacked; /* State flags for SACK/FACK. */
581#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
582#define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
583#define TCPCB_LOST 0x04 /* SKB is lost */
584#define TCPCB_TAGBITS 0x07 /* All tag bits */
585
586#define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */
587#define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
588
1da177e4
LT		 589 __u16 urg_ptr; /* Valid w/URG flags is set. */
590 __u32 ack_seq; /* Sequence number ACK'd */
591};
592
593#define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
594
1da177e4
LT		 595/* Due to TSO, an SKB can be composed of multiple actual
596 * packets. To keep these tracked properly, we use this.
597 */
598static inline int tcp_skb_pcount(const struct sk_buff *skb)
599{
7967168c 600 return skb_shinfo(skb)->gso_segs;
1da177e4
LT		 601}
602
603/* This is valid iff tcp_skb_pcount() > 1. */
604static inline int tcp_skb_mss(const struct sk_buff *skb)
605{
7967168c 606 return skb_shinfo(skb)->gso_size;
1da177e4
LT		 607}
608
af610b4c 609static inline void tcp_dec_pcount_approx_int(__u32 *count, const int decr)
1da177e4
LT		 610{
611 if (*count) {
af610b4c 612 *count -= decr;
1da177e4
LT		 613 if ((int)*count < 0)
614 *count = 0;
615 }
616}
617
af610b4c
IJ		 618static inline void tcp_dec_pcount_approx(__u32 *count,
619 const struct sk_buff *skb)
620{
621 tcp_dec_pcount_approx_int(count, tcp_skb_pcount(skb));
622}
623
317a76f9
SH		 624/* Events passed to congestion control interface */
625enum tcp_ca_event {
626 CA_EVENT_TX_START, /* first transmit when no packets in flight */
627 CA_EVENT_CWND_RESTART, /* congestion window restart */
628 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
629 CA_EVENT_FRTO, /* fast recovery timeout */
630 CA_EVENT_LOSS, /* loss timeout */
631 CA_EVENT_FAST_ACK, /* in sequence ack */
632 CA_EVENT_SLOW_ACK, /* other ack */
633};
634
635/*
636 * Interface for adding new TCP congestion control handlers
637 */
638#define TCP_CA_NAME_MAX 16
3ff825b2
SH		 639#define TCP_CA_MAX 128
640#define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX)
641
164891aa
SH		 642#define TCP_CONG_NON_RESTRICTED 0x1
643#define TCP_CONG_RTT_STAMP 0x2
644
317a76f9
SH		 645struct tcp_congestion_ops {
646 struct list_head list;
164891aa 647 unsigned long flags;
317a76f9
SH		 648
649 /* initialize private data (optional) */
6687e988 650 void (*init)(struct sock *sk);
317a76f9 651 /* cleanup private data (optional) */
6687e988 652 void (*release)(struct sock *sk);
317a76f9
SH		 653
654 /* return slow start threshold (required) */
6687e988 655 u32 (*ssthresh)(struct sock *sk);
317a76f9 656 /* lower bound for congestion window (optional) */
72dc5b92 657 u32 (*min_cwnd)(const struct sock *sk);
317a76f9 658 /* do new cwnd calculation (required) */
c3a05c60 659 void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight);
317a76f9 660 /* call before changing ca_state (optional) */
6687e988 661 void (*set_state)(struct sock *sk, u8 new_state);
317a76f9 662 /* call when cwnd event occurs (optional) */
6687e988 663 void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
317a76f9 664 /* new value of cwnd after loss (optional) */
6687e988 665 u32 (*undo_cwnd)(struct sock *sk);
317a76f9 666 /* hook for packet ack accounting (optional) */
30cfd0ba 667 void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us);
73c1f4a0 668 /* get info for inet_diag (optional) */
6687e988 669 void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb);
317a76f9
SH		 670
671 char name[TCP_CA_NAME_MAX];
672 struct module *owner;
673};
674
675extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
676extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
677
6687e988
ACM		 678extern void tcp_init_congestion_control(struct sock *sk);
679extern void tcp_cleanup_congestion_control(struct sock *sk);
317a76f9
SH		 680extern int tcp_set_default_congestion_control(const char *name);
681extern void tcp_get_default_congestion_control(char *name);
3ff825b2 682extern void tcp_get_available_congestion_control(char *buf, size_t len);
ce7bc3bf
SH		 683extern void tcp_get_allowed_congestion_control(char *buf, size_t len);
684extern int tcp_set_allowed_congestion_control(char *allowed);
6687e988 685extern int tcp_set_congestion_control(struct sock *sk, const char *name);
40efc6fa 686extern void tcp_slow_start(struct tcp_sock *tp);
317a76f9 687
5f8ef48d 688extern struct tcp_congestion_ops tcp_init_congestion_ops;
6687e988 689extern u32 tcp_reno_ssthresh(struct sock *sk);
c3a05c60 690extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight);
72dc5b92 691extern u32 tcp_reno_min_cwnd(const struct sock *sk);
a8acfbac 692extern struct tcp_congestion_ops tcp_reno;
317a76f9 693
6687e988 694static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state)
317a76f9 695{
6687e988
ACM		 696 struct inet_connection_sock *icsk = inet_csk(sk);
697
698 if (icsk->icsk_ca_ops->set_state)
699 icsk->icsk_ca_ops->set_state(sk, ca_state);
700 icsk->icsk_ca_state = ca_state;
317a76f9
SH		 701}
702
6687e988 703static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event)
317a76f9 704{
6687e988
ACM		 705 const struct inet_connection_sock *icsk = inet_csk(sk);
706
707 if (icsk->icsk_ca_ops->cwnd_event)
708 icsk->icsk_ca_ops->cwnd_event(sk, event);
317a76f9
SH		 709}
710
e60402d0
IJ		 711/* These functions determine how the current flow behaves in respect of SACK
712 * handling. SACK is negotiated with the peer, and therefore it can vary
713 * between different flows.
714 *
715 * tcp_is_sack - SACK enabled
716 * tcp_is_reno - No SACK
717 * tcp_is_fack - FACK enabled, implies SACK enabled
718 */
719static inline int tcp_is_sack(const struct tcp_sock *tp)
720{
721 return tp->rx_opt.sack_ok;
722}
723
724static inline int tcp_is_reno(const struct tcp_sock *tp)
725{
726 return !tcp_is_sack(tp);
727}
728
729static inline int tcp_is_fack(const struct tcp_sock *tp)
730{
731 return tp->rx_opt.sack_ok & 2;
732}
733
734static inline void tcp_enable_fack(struct tcp_sock *tp)
735{
736 tp->rx_opt.sack_ok |= 2;
737}
738
83ae4088
IJ		 739static inline unsigned int tcp_left_out(const struct tcp_sock *tp)
740{
741 return tp->sacked_out + tp->lost_out;
742}
743
1da177e4
LT		 744/* This determines how many packets are "in the network" to the best
745 * of our knowledge. In many cases it is conservative, but where
746 * detailed information is available from the receiver (via SACK
747 * blocks etc.) we can make more aggressive calculations.
748 *
749 * Use this for decisions involving congestion control, use just
750 * tp->packets_out to determine if the send queue is empty or not.
751 *
752 * Read this equation as:
753 *
754 * "Packets sent once on transmission queue" MINUS
755 * "Packets left network, but not honestly ACKed yet" PLUS
756 * "Packets fast retransmitted"
757 */
40efc6fa 758static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
1da177e4 759{
83ae4088 760 return tp->packets_out - tcp_left_out(tp) + tp->retrans_out;
1da177e4
LT		 761}
762
1da177e4
LT		 763/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
764 * The exception is rate halving phase, when cwnd is decreasing towards
765 * ssthresh.
766 */
6687e988 767static inline __u32 tcp_current_ssthresh(const struct sock *sk)
1da177e4 768{
6687e988
ACM		 769 const struct tcp_sock *tp = tcp_sk(sk);
770 if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery))
1da177e4
LT		 771 return tp->snd_ssthresh;
772 else
773 return max(tp->snd_ssthresh,
774 ((tp->snd_cwnd >> 1) +
775 (tp->snd_cwnd >> 2)));
776}
777
b9c4595b
IJ		 778/* Use define here intentionally to get WARN_ON location shown at the caller */
779#define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out)
1da177e4 780
3cfe3baa 781extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh);
1da177e4
LT		 782extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst);
783
784/* Slow start with delack produces 3 packets of burst, so that
785 * it is safe "de facto".
786 */
787static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
788{
789 return 3;
790}
791
90840def
IJ		 792/* Returns end sequence number of the receiver's advertised window */
793static inline u32 tcp_wnd_end(const struct tcp_sock *tp)
794{
795 return tp->snd_una + tp->snd_wnd;
796}
cea14e0e 797extern int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight);
f4805ede 798
c1bd24b7 799static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss,
40efc6fa 800 const struct sk_buff *skb)
1da177e4
LT		 801{
802 if (skb->len < mss)
803 tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
804}
805
9e412ba7 806static inline void tcp_check_probe_timer(struct sock *sk)
1da177e4 807{
9e412ba7 808 struct tcp_sock *tp = tcp_sk(sk);
463c84b9 809 const struct inet_connection_sock *icsk = inet_csk(sk);
9e412ba7 810
463c84b9 811 if (!tp->packets_out && !icsk->icsk_pending)
3f421baa
ACM		 812 inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
813 icsk->icsk_rto, TCP_RTO_MAX);
1da177e4
LT		 814}
815
9e412ba7 816static inline void tcp_push_pending_frames(struct sock *sk)
1da177e4 817{
9e412ba7
IJ		 818 struct tcp_sock *tp = tcp_sk(sk);
819
820 __tcp_push_pending_frames(sk, tcp_current_mss(sk, 1), tp->nonagle);
1da177e4
LT		 821}
822
40efc6fa 823static inline void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq)
1da177e4
LT		 824{
825 tp->snd_wl1 = seq;
826}
827
40efc6fa 828static inline void tcp_update_wl(struct tcp_sock *tp, u32 ack, u32 seq)
1da177e4
LT		 829{
830 tp->snd_wl1 = seq;
831}
832
1da177e4
LT		 833/*
834 * Calculate(/check) TCP checksum
835 */
ba7808ea
FD		 836static inline __sum16 tcp_v4_check(int len, __be32 saddr,
837 __be32 daddr, __wsum base)
1da177e4
LT		 838{
839 return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base);
840}
841
b51655b9 842static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb)
1da177e4 843{
fb286bb2 844 return __skb_checksum_complete(skb);
1da177e4
LT		 845}
846
40efc6fa 847static inline int tcp_checksum_complete(struct sk_buff *skb)
1da177e4 848{
60476372 849 return !skb_csum_unnecessary(skb) &&
1da177e4
LT		 850 __tcp_checksum_complete(skb);
851}
852
853/* Prequeue for VJ style copy to user, combined with checksumming. */
854
40efc6fa 855static inline void tcp_prequeue_init(struct tcp_sock *tp)
1da177e4
LT		 856{
857 tp->ucopy.task = NULL;
858 tp->ucopy.len = 0;
859 tp->ucopy.memory = 0;
860 skb_queue_head_init(&tp->ucopy.prequeue);
97fc2f08
CL		 861#ifdef CONFIG_NET_DMA
862 tp->ucopy.dma_chan = NULL;
863 tp->ucopy.wakeup = 0;
864 tp->ucopy.pinned_list = NULL;
865 tp->ucopy.dma_cookie = 0;
866#endif
1da177e4
LT		 867}
868
869/* Packet is added to VJ-style prequeue for processing in process
870 * context, if a reader task is waiting. Apparently, this exciting
871 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
872 * failed somewhere. Latency? Burstiness? Well, at least now we will
873 * see, why it failed. 8)8) --ANK
874 *
875 * NOTE: is this not too big to inline?
876 */
40efc6fa 877static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb)
1da177e4
LT		 878{
879 struct tcp_sock *tp = tcp_sk(sk);
880
881 if (!sysctl_tcp_low_latency && tp->ucopy.task) {
882 __skb_queue_tail(&tp->ucopy.prequeue, skb);
883 tp->ucopy.memory += skb->truesize;
884 if (tp->ucopy.memory > sk->sk_rcvbuf) {
885 struct sk_buff *skb1;
886
887 BUG_ON(sock_owned_by_user(sk));
888
889 while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) {
890 sk->sk_backlog_rcv(sk, skb1);
891 NET_INC_STATS_BH(LINUX_MIB_TCPPREQUEUEDROPPED);
892 }
893
894 tp->ucopy.memory = 0;
895 } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) {
896 wake_up_interruptible(sk->sk_sleep);
463c84b9
ACM		 897 if (!inet_csk_ack_scheduled(sk))
898 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
3f421baa
ACM		 899 (3 * TCP_RTO_MIN) / 4,
900 TCP_RTO_MAX);
1da177e4
LT		 901 }
902 return 1;
903 }
904 return 0;
905}
906
907
908#undef STATE_TRACE
909
910#ifdef STATE_TRACE
911static const char *statename[]={
912 "Unused","Established","Syn Sent","Syn Recv",
913 "Fin Wait 1","Fin Wait 2","Time Wait", "Close",
914 "Close Wait","Last ACK","Listen","Closing"
915};
916#endif
490d5046 917extern void tcp_set_state(struct sock *sk, int state);
1da177e4 918
4ac02bab 919extern void tcp_done(struct sock *sk);
1da177e4 920
40efc6fa 921static inline void tcp_sack_reset(struct tcp_options_received *rx_opt)
1da177e4
LT		 922{
923 rx_opt->dsack = 0;
924 rx_opt->eff_sacks = 0;
925 rx_opt->num_sacks = 0;
926}
927
1da177e4
LT		 928/* Determine a window scaling and initial window to offer. */
929extern void tcp_select_initial_window(int __space, __u32 mss,
930 __u32 *rcv_wnd, __u32 *window_clamp,
931 int wscale_ok, __u8 *rcv_wscale);
932
933static inline int tcp_win_from_space(int space)
934{
935 return sysctl_tcp_adv_win_scale<=0 ?
936 (space>>(-sysctl_tcp_adv_win_scale)) :
937 space - (space>>sysctl_tcp_adv_win_scale);
938}
939
940/* Note: caller must be prepared to deal with negative returns */
941static inline int tcp_space(const struct sock *sk)
942{
943 return tcp_win_from_space(sk->sk_rcvbuf -
944 atomic_read(&sk->sk_rmem_alloc));
945}
946
947static inline int tcp_full_space(const struct sock *sk)
948{
949 return tcp_win_from_space(sk->sk_rcvbuf);
950}
951
40efc6fa
SH		 952static inline void tcp_openreq_init(struct request_sock *req,
953 struct tcp_options_received *rx_opt,
954 struct sk_buff *skb)
1da177e4 955{
2e6599cb
ACM		 956 struct inet_request_sock *ireq = inet_rsk(req);
957
1da177e4 958 req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */
2e6599cb 959 tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
1da177e4
LT		 960 req->mss = rx_opt->mss_clamp;
961 req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
2e6599cb
ACM		 962 ireq->tstamp_ok = rx_opt->tstamp_ok;
963 ireq->sack_ok = rx_opt->sack_ok;
964 ireq->snd_wscale = rx_opt->snd_wscale;
965 ireq->wscale_ok = rx_opt->wscale_ok;
966 ireq->acked = 0;
967 ireq->ecn_ok = 0;
aa8223c7 968 ireq->rmt_port = tcp_hdr(skb)->source;
1da177e4
LT		 969}
970
971extern void tcp_enter_memory_pressure(void);
972
1da177e4
LT		 973static inline int keepalive_intvl_when(const struct tcp_sock *tp)
974{
975 return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl;
976}
977
978static inline int keepalive_time_when(const struct tcp_sock *tp)
979{
980 return tp->keepalive_time ? : sysctl_tcp_keepalive_time;
981}
982
463c84b9 983static inline int tcp_fin_time(const struct sock *sk)
1da177e4 984{
463c84b9
ACM		 985 int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout;
986 const int rto = inet_csk(sk)->icsk_rto;
1da177e4 987
463c84b9
ACM		 988 if (fin_timeout < (rto << 2) - (rto >> 1))
989 fin_timeout = (rto << 2) - (rto >> 1);
1da177e4
LT		 990
991 return fin_timeout;
992}
993
994static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, int rst)
995{
996 if ((s32)(rx_opt->rcv_tsval - rx_opt->ts_recent) >= 0)
997 return 0;
9d729f72 998 if (get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)
1da177e4
LT		 999 return 0;
1000
1001 /* RST segments are not recommended to carry timestamp,
1002 and, if they do, it is recommended to ignore PAWS because
1003 "their cleanup function should take precedence over timestamps."
1004 Certainly, it is mistake. It is necessary to understand the reasons
1005 of this constraint to relax it: if peer reboots, clock may go
1006 out-of-sync and half-open connections will not be reset.
1007 Actually, the problem would be not existing if all
1008 the implementations followed draft about maintaining clock
1009 via reboots. Linux-2.2 DOES NOT!
1010
1011 However, we can relax time bounds for RST segments to MSL.
1012 */
9d729f72 1013 if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
1da177e4
LT		 1014 return 0;
1015 return 1;
1016}
1017
1da177e4
LT		 1018#define TCP_CHECK_TIMER(sk) do { } while (0)
1019
1da177e4
LT		 1020static inline void tcp_mib_init(void)
1021{
1022 /* See RFC 2012 */
1023 TCP_ADD_STATS_USER(TCP_MIB_RTOALGORITHM, 1);
1024 TCP_ADD_STATS_USER(TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ);
1025 TCP_ADD_STATS_USER(TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ);
1026 TCP_ADD_STATS_USER(TCP_MIB_MAXCONN, -1);
1027}
1028
5af4ec23 1029/* from STCP */
0800f170
DM		 1030static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp)
1031{
6a438bbe
SH		 1032 tp->lost_skb_hint = NULL;
1033 tp->scoreboard_skb_hint = NULL;
1034 tp->retransmit_skb_hint = NULL;
1035 tp->forward_skb_hint = NULL;
b7689205
IJ		 1036}
1037
0800f170
DM		 1038static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp)
1039{
b7689205 1040 tcp_clear_retrans_hints_partial(tp);
6a438bbe
SH		 1041}
1042
cfb6eeb4
YH		 1043/* MD5 Signature */
1044struct crypto_hash;
1045
1046/* - key database */
1047struct tcp_md5sig_key {
1048 u8 *key;
1049 u8 keylen;
1050};
1051
1052struct tcp4_md5sig_key {
f8ab18d2 1053 struct tcp_md5sig_key base;
cfb6eeb4
YH		 1054 __be32 addr;
1055};
1056
1057struct tcp6_md5sig_key {
f8ab18d2 1058 struct tcp_md5sig_key base;
cfb6eeb4
YH		 1059#if 0
1060 u32 scope_id; /* XXX */
1061#endif
1062 struct in6_addr addr;
1063};
1064
1065/* - sock block */
1066struct tcp_md5sig_info {
1067 struct tcp4_md5sig_key *keys4;
1068#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1069 struct tcp6_md5sig_key *keys6;
1070 u32 entries6;
1071 u32 alloced6;
1072#endif
1073 u32 entries4;
1074 u32 alloced4;
1075};
1076
1077/* - pseudo header */
1078struct tcp4_pseudohdr {
1079 __be32 saddr;
1080 __be32 daddr;
1081 __u8 pad;
1082 __u8 protocol;
1083 __be16 len;
1084};
1085
1086struct tcp6_pseudohdr {
1087 struct in6_addr saddr;
1088 struct in6_addr daddr;
1089 __be32 len;
1090 __be32 protocol; /* including padding */
1091};
1092
1093union tcp_md5sum_block {
1094 struct tcp4_pseudohdr ip4;
1095#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1096 struct tcp6_pseudohdr ip6;
1097#endif
1098};
1099
1100/* - pool: digest algorithm, hash description and scratch buffer */
1101struct tcp_md5sig_pool {
1102 struct hash_desc md5_desc;
1103 union tcp_md5sum_block md5_blk;
1104};
1105
1106#define TCP_MD5SIG_MAXKEYS (~(u32)0) /* really?! */
1107
1108/* - functions */
1109extern int tcp_v4_calc_md5_hash(char *md5_hash,
1110 struct tcp_md5sig_key *key,
1111 struct sock *sk,
1112 struct dst_entry *dst,
1113 struct request_sock *req,
1114 struct tcphdr *th,
9cb5734e
YH		 1115 int protocol,
1116 unsigned int tcplen);
cfb6eeb4
YH		 1117extern struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
1118 struct sock *addr_sk);
1119
1120extern int tcp_v4_md5_do_add(struct sock *sk,
1121 __be32 addr,
1122 u8 *newkey,
1123 u8 newkeylen);
1124
1125extern int tcp_v4_md5_do_del(struct sock *sk,
8e5200f5 1126 __be32 addr);
cfb6eeb4
YH		 1127
1128extern struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void);
1129extern void tcp_free_md5sig_pool(void);
1130
1131extern struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu);
1132extern void __tcp_put_md5sig_pool(void);
1133
1134static inline
1135struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
1136{
1137 int cpu = get_cpu();
1138 struct tcp_md5sig_pool *ret = __tcp_get_md5sig_pool(cpu);
1139 if (!ret)
1140 put_cpu();
1141 return ret;
1142}
1143
1144static inline void tcp_put_md5sig_pool(void)
1145{
1146 __tcp_put_md5sig_pool();
1147 put_cpu();
1148}
1149
fe067e8a
DM		 1150/* write queue abstraction */
1151static inline void tcp_write_queue_purge(struct sock *sk)
1152{
1153 struct sk_buff *skb;
1154
1155 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
3ab224be
HA		 1156 sk_wmem_free_skb(sk, skb);
1157 sk_mem_reclaim(sk);
fe067e8a
DM		 1158}
1159
1160static inline struct sk_buff *tcp_write_queue_head(struct sock *sk)
1161{
1162 struct sk_buff *skb = sk->sk_write_queue.next;
1163 if (skb == (struct sk_buff *) &sk->sk_write_queue)
1164 return NULL;
1165 return skb;
1166}
1167
1168static inline struct sk_buff *tcp_write_queue_tail(struct sock *sk)
1169{
1170 struct sk_buff *skb = sk->sk_write_queue.prev;
1171 if (skb == (struct sk_buff *) &sk->sk_write_queue)
1172 return NULL;
1173 return skb;
1174}
1175
1176static inline struct sk_buff *tcp_write_queue_next(struct sock *sk, struct sk_buff *skb)
1177{
1178 return skb->next;
1179}
1180
1181#define tcp_for_write_queue(skb, sk) \
1182 for (skb = (sk)->sk_write_queue.next; \
1183 (skb != (struct sk_buff *)&(sk)->sk_write_queue); \
1184 skb = skb->next)
1185
1186#define tcp_for_write_queue_from(skb, sk) \
1187 for (; (skb != (struct sk_buff *)&(sk)->sk_write_queue);\
1188 skb = skb->next)
1189
234b6860
IJ		 1190#define tcp_for_write_queue_from_safe(skb, tmp, sk) \
1191 for (tmp = skb->next; \
1192 (skb != (struct sk_buff *)&(sk)->sk_write_queue); \
1193 skb = tmp, tmp = skb->next)
1194
fe067e8a
DM		 1195static inline struct sk_buff *tcp_send_head(struct sock *sk)
1196{
1197 return sk->sk_send_head;
1198}
1199
1200static inline void tcp_advance_send_head(struct sock *sk, struct sk_buff *skb)
1201{
1202 sk->sk_send_head = skb->next;
1203 if (sk->sk_send_head == (struct sk_buff *)&sk->sk_write_queue)
1204 sk->sk_send_head = NULL;
1205}
1206
1207static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked)
1208{
1209 if (sk->sk_send_head == skb_unlinked)
1210 sk->sk_send_head = NULL;
1211}
1212
1213static inline void tcp_init_send_head(struct sock *sk)
1214{
1215 sk->sk_send_head = NULL;
1216}
1217
1218static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
1219{
1220 __skb_queue_tail(&sk->sk_write_queue, skb);
1221}
1222
1223static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
1224{
1225 __tcp_add_write_queue_tail(sk, skb);
1226
1227 /* Queue it, remembering where we must start sending. */
6859d494 1228 if (sk->sk_send_head == NULL) {
fe067e8a 1229 sk->sk_send_head = skb;
6859d494
IJ		 1230
1231 if (tcp_sk(sk)->highest_sack == NULL)
1232 tcp_sk(sk)->highest_sack = skb;
1233 }
fe067e8a
DM		 1234}
1235
1236static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb)
1237{
1238 __skb_queue_head(&sk->sk_write_queue, skb);
1239}
1240
1241/* Insert buff after skb on the write queue of sk. */
1242static inline void tcp_insert_write_queue_after(struct sk_buff *skb,
1243 struct sk_buff *buff,
1244 struct sock *sk)
1245{
1246 __skb_append(skb, buff, &sk->sk_write_queue);
1247}
1248
1249/* Insert skb between prev and next on the write queue of sk. */
1250static inline void tcp_insert_write_queue_before(struct sk_buff *new,
1251 struct sk_buff *skb,
1252 struct sock *sk)
1253{
1254 __skb_insert(new, skb->prev, skb, &sk->sk_write_queue);