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Commit | Line | Data |
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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> |
435cf559 | 33 | #include <linux/kref.h> |
3f421baa ACM |
34 | |
35 | #include <net/inet_connection_sock.h> | |
295ff7ed | 36 | #include <net/inet_timewait_sock.h> |
77d8bf9c | 37 | #include <net/inet_hashtables.h> |
1da177e4 | 38 | #include <net/checksum.h> |
2e6599cb | 39 | #include <net/request_sock.h> |
1da177e4 LT |
40 | #include <net/sock.h> |
41 | #include <net/snmp.h> | |
42 | #include <net/ip.h> | |
c752f073 | 43 | #include <net/tcp_states.h> |
bdf1ee5d | 44 | #include <net/inet_ecn.h> |
0c266898 | 45 | #include <net/dst.h> |
c752f073 | 46 | |
1da177e4 LT |
47 | #include <linux/seq_file.h> |
48 | ||
6e04e021 | 49 | extern struct inet_hashinfo tcp_hashinfo; |
1da177e4 | 50 | |
dd24c001 | 51 | extern struct percpu_counter tcp_orphan_count; |
1da177e4 | 52 | extern void tcp_time_wait(struct sock *sk, int state, int timeo); |
1da177e4 | 53 | |
1da177e4 | 54 | #define MAX_TCP_HEADER (128 + MAX_HEADER) |
33ad798c | 55 | #define MAX_TCP_OPTION_SPACE 40 |
1da177e4 LT |
56 | |
57 | /* | |
58 | * Never offer a window over 32767 without using window scaling. Some | |
59 | * poor stacks do signed 16bit maths! | |
60 | */ | |
61 | #define MAX_TCP_WINDOW 32767U | |
62 | ||
356f0398 ND |
63 | /* Offer an initial receive window of 10 mss. */ |
64 | #define TCP_DEFAULT_INIT_RCVWND 10 | |
65 | ||
1da177e4 LT |
66 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ |
67 | #define TCP_MIN_MSS 88U | |
68 | ||
5d424d5a JH |
69 | /* The least MTU to use for probing */ |
70 | #define TCP_BASE_MSS 512 | |
71 | ||
1da177e4 LT |
72 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
73 | #define TCP_FASTRETRANS_THRESH 3 | |
74 | ||
75 | /* Maximal reordering. */ | |
76 | #define TCP_MAX_REORDERING 127 | |
77 | ||
78 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ | |
79 | #define TCP_MAX_QUICKACKS 16U | |
80 | ||
81 | /* urg_data states */ | |
82 | #define TCP_URG_VALID 0x0100 | |
83 | #define TCP_URG_NOTYET 0x0200 | |
84 | #define TCP_URG_READ 0x0400 | |
85 | ||
86 | #define TCP_RETR1 3 /* | |
87 | * This is how many retries it does before it | |
88 | * tries to figure out if the gateway is | |
89 | * down. Minimal RFC value is 3; it corresponds | |
90 | * to ~3sec-8min depending on RTO. | |
91 | */ | |
92 | ||
93 | #define TCP_RETR2 15 /* | |
94 | * This should take at least | |
95 | * 90 minutes to time out. | |
96 | * RFC1122 says that the limit is 100 sec. | |
97 | * 15 is ~13-30min depending on RTO. | |
98 | */ | |
99 | ||
100 | #define TCP_SYN_RETRIES 5 /* number of times to retry active opening a | |
caa20d9a | 101 | * connection: ~180sec is RFC minimum */ |
1da177e4 LT |
102 | |
103 | #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a | |
caa20d9a | 104 | * connection: ~180sec is RFC minimum */ |
1da177e4 | 105 | |
1da177e4 LT |
106 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
107 | * state, about 60 seconds */ | |
108 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN | |
109 | /* BSD style FIN_WAIT2 deadlock breaker. | |
110 | * It used to be 3min, new value is 60sec, | |
111 | * to combine FIN-WAIT-2 timeout with | |
112 | * TIME-WAIT timer. | |
113 | */ | |
114 | ||
115 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ | |
116 | #if HZ >= 100 | |
117 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ | |
118 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) | |
119 | #else | |
120 | #define TCP_DELACK_MIN 4U | |
121 | #define TCP_ATO_MIN 4U | |
122 | #endif | |
123 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) | |
124 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) | |
9ad7c049 JC |
125 | #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC2988bis initial RTO value */ |
126 | #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now | |
127 | * used as a fallback RTO for the | |
128 | * initial data transmission if no | |
129 | * valid RTT sample has been acquired, | |
130 | * most likely due to retrans in 3WHS. | |
131 | */ | |
1da177e4 LT |
132 | |
133 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes | |
134 | * for local resources. | |
135 | */ | |
136 | ||
137 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ | |
138 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ | |
139 | #define TCP_KEEPALIVE_INTVL (75*HZ) | |
140 | ||
141 | #define MAX_TCP_KEEPIDLE 32767 | |
142 | #define MAX_TCP_KEEPINTVL 32767 | |
143 | #define MAX_TCP_KEEPCNT 127 | |
144 | #define MAX_TCP_SYNCNT 127 | |
145 | ||
146 | #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ | |
1da177e4 LT |
147 | |
148 | #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) | |
149 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated | |
150 | * after this time. It should be equal | |
151 | * (or greater than) TCP_TIMEWAIT_LEN | |
152 | * to provide reliability equal to one | |
153 | * provided by timewait state. | |
154 | */ | |
155 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host | |
156 | * timestamps. It must be less than | |
157 | * minimal timewait lifetime. | |
158 | */ | |
1da177e4 LT |
159 | /* |
160 | * TCP option | |
161 | */ | |
162 | ||
163 | #define TCPOPT_NOP 1 /* Padding */ | |
164 | #define TCPOPT_EOL 0 /* End of options */ | |
165 | #define TCPOPT_MSS 2 /* Segment size negotiating */ | |
166 | #define TCPOPT_WINDOW 3 /* Window scaling */ | |
167 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ | |
168 | #define TCPOPT_SACK 5 /* SACK Block */ | |
169 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ | |
cfb6eeb4 | 170 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
435cf559 | 171 | #define TCPOPT_COOKIE 253 /* Cookie extension (experimental) */ |
1da177e4 LT |
172 | |
173 | /* | |
174 | * TCP option lengths | |
175 | */ | |
176 | ||
177 | #define TCPOLEN_MSS 4 | |
178 | #define TCPOLEN_WINDOW 3 | |
179 | #define TCPOLEN_SACK_PERM 2 | |
180 | #define TCPOLEN_TIMESTAMP 10 | |
cfb6eeb4 | 181 | #define TCPOLEN_MD5SIG 18 |
435cf559 WAS |
182 | #define TCPOLEN_COOKIE_BASE 2 /* Cookie-less header extension */ |
183 | #define TCPOLEN_COOKIE_PAIR 3 /* Cookie pair header extension */ | |
184 | #define TCPOLEN_COOKIE_MIN (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MIN) | |
185 | #define TCPOLEN_COOKIE_MAX (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MAX) | |
1da177e4 LT |
186 | |
187 | /* But this is what stacks really send out. */ | |
188 | #define TCPOLEN_TSTAMP_ALIGNED 12 | |
189 | #define TCPOLEN_WSCALE_ALIGNED 4 | |
190 | #define TCPOLEN_SACKPERM_ALIGNED 4 | |
191 | #define TCPOLEN_SACK_BASE 2 | |
192 | #define TCPOLEN_SACK_BASE_ALIGNED 4 | |
193 | #define TCPOLEN_SACK_PERBLOCK 8 | |
cfb6eeb4 | 194 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
33ad798c | 195 | #define TCPOLEN_MSS_ALIGNED 4 |
1da177e4 | 196 | |
1da177e4 LT |
197 | /* Flags in tp->nonagle */ |
198 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ | |
199 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ | |
caa20d9a | 200 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
1da177e4 | 201 | |
36e31b0a AP |
202 | /* TCP thin-stream limits */ |
203 | #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ | |
204 | ||
7eb38527 | 205 | /* TCP initial congestion window as per draft-hkchu-tcpm-initcwnd-01 */ |
442b9635 DM |
206 | #define TCP_INIT_CWND 10 |
207 | ||
295ff7ed ACM |
208 | extern struct inet_timewait_death_row tcp_death_row; |
209 | ||
1da177e4 | 210 | /* sysctl variables for tcp */ |
1da177e4 LT |
211 | extern int sysctl_tcp_timestamps; |
212 | extern int sysctl_tcp_window_scaling; | |
213 | extern int sysctl_tcp_sack; | |
214 | extern int sysctl_tcp_fin_timeout; | |
1da177e4 LT |
215 | extern int sysctl_tcp_keepalive_time; |
216 | extern int sysctl_tcp_keepalive_probes; | |
217 | extern int sysctl_tcp_keepalive_intvl; | |
218 | extern int sysctl_tcp_syn_retries; | |
219 | extern int sysctl_tcp_synack_retries; | |
220 | extern int sysctl_tcp_retries1; | |
221 | extern int sysctl_tcp_retries2; | |
222 | extern int sysctl_tcp_orphan_retries; | |
223 | extern int sysctl_tcp_syncookies; | |
224 | extern int sysctl_tcp_retrans_collapse; | |
225 | extern int sysctl_tcp_stdurg; | |
226 | extern int sysctl_tcp_rfc1337; | |
227 | extern int sysctl_tcp_abort_on_overflow; | |
228 | extern int sysctl_tcp_max_orphans; | |
1da177e4 LT |
229 | extern int sysctl_tcp_fack; |
230 | extern int sysctl_tcp_reordering; | |
231 | extern int sysctl_tcp_ecn; | |
232 | extern int sysctl_tcp_dsack; | |
8d987e5c | 233 | extern long sysctl_tcp_mem[3]; |
1da177e4 LT |
234 | extern int sysctl_tcp_wmem[3]; |
235 | extern int sysctl_tcp_rmem[3]; | |
236 | extern int sysctl_tcp_app_win; | |
237 | extern int sysctl_tcp_adv_win_scale; | |
238 | extern int sysctl_tcp_tw_reuse; | |
239 | extern int sysctl_tcp_frto; | |
3cfe3baa | 240 | extern int sysctl_tcp_frto_response; |
1da177e4 | 241 | extern int sysctl_tcp_low_latency; |
95937825 | 242 | extern int sysctl_tcp_dma_copybreak; |
1da177e4 | 243 | extern int sysctl_tcp_nometrics_save; |
1da177e4 LT |
244 | extern int sysctl_tcp_moderate_rcvbuf; |
245 | extern int sysctl_tcp_tso_win_divisor; | |
9772efb9 | 246 | extern int sysctl_tcp_abc; |
5d424d5a JH |
247 | extern int sysctl_tcp_mtu_probing; |
248 | extern int sysctl_tcp_base_mss; | |
15d99e02 | 249 | extern int sysctl_tcp_workaround_signed_windows; |
35089bb2 | 250 | extern int sysctl_tcp_slow_start_after_idle; |
886236c1 | 251 | extern int sysctl_tcp_max_ssthresh; |
519855c5 | 252 | extern int sysctl_tcp_cookie_size; |
36e31b0a | 253 | extern int sysctl_tcp_thin_linear_timeouts; |
7e380175 | 254 | extern int sysctl_tcp_thin_dupack; |
1da177e4 | 255 | |
8d987e5c | 256 | extern atomic_long_t tcp_memory_allocated; |
1748376b | 257 | extern struct percpu_counter tcp_sockets_allocated; |
1da177e4 LT |
258 | extern int tcp_memory_pressure; |
259 | ||
1da177e4 LT |
260 | /* |
261 | * The next routines deal with comparing 32 bit unsigned ints | |
262 | * and worry about wraparound (automatic with unsigned arithmetic). | |
263 | */ | |
264 | ||
265 | static inline int before(__u32 seq1, __u32 seq2) | |
266 | { | |
0d630cc0 | 267 | return (__s32)(seq1-seq2) < 0; |
1da177e4 | 268 | } |
9a036b9c | 269 | #define after(seq2, seq1) before(seq1, seq2) |
1da177e4 LT |
270 | |
271 | /* is s2<=s1<=s3 ? */ | |
272 | static inline int between(__u32 seq1, __u32 seq2, __u32 seq3) | |
273 | { | |
274 | return seq3 - seq2 >= seq1 - seq2; | |
275 | } | |
276 | ||
ad1af0fe | 277 | static inline bool tcp_too_many_orphans(struct sock *sk, int shift) |
e4fd5da3 | 278 | { |
ad1af0fe DM |
279 | struct percpu_counter *ocp = sk->sk_prot->orphan_count; |
280 | int orphans = percpu_counter_read_positive(ocp); | |
281 | ||
282 | if (orphans << shift > sysctl_tcp_max_orphans) { | |
283 | orphans = percpu_counter_sum_positive(ocp); | |
284 | if (orphans << shift > sysctl_tcp_max_orphans) | |
285 | return true; | |
286 | } | |
287 | ||
288 | if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && | |
8d987e5c | 289 | atomic_long_read(&tcp_memory_allocated) > sysctl_tcp_mem[2]) |
ad1af0fe DM |
290 | return true; |
291 | return false; | |
e4fd5da3 | 292 | } |
1da177e4 | 293 | |
a0f82f64 FW |
294 | /* syncookies: remember time of last synqueue overflow */ |
295 | static inline void tcp_synq_overflow(struct sock *sk) | |
296 | { | |
297 | tcp_sk(sk)->rx_opt.ts_recent_stamp = jiffies; | |
298 | } | |
299 | ||
300 | /* syncookies: no recent synqueue overflow on this listening socket? */ | |
301 | static inline int tcp_synq_no_recent_overflow(const struct sock *sk) | |
302 | { | |
303 | unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; | |
9ad7c049 | 304 | return time_after(jiffies, last_overflow + TCP_TIMEOUT_FALLBACK); |
a0f82f64 FW |
305 | } |
306 | ||
1da177e4 LT |
307 | extern struct proto tcp_prot; |
308 | ||
57ef42d5 PE |
309 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
310 | #define TCP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.tcp_statistics, field) | |
311 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) | |
312 | #define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val) | |
aa2ea058 | 313 | #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) |
1da177e4 | 314 | |
53d3176b CG |
315 | extern void tcp_v4_err(struct sk_buff *skb, u32); |
316 | ||
317 | extern void tcp_shutdown (struct sock *sk, int how); | |
318 | ||
319 | extern int tcp_v4_rcv(struct sk_buff *skb); | |
320 | ||
3f419d2d | 321 | extern struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it); |
ccb7c410 | 322 | extern void *tcp_v4_tw_get_peer(struct sock *sk); |
53d3176b | 323 | extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); |
7ba42910 CG |
324 | extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, |
325 | size_t size); | |
326 | extern int tcp_sendpage(struct sock *sk, struct page *page, int offset, | |
327 | size_t size, int flags); | |
53d3176b CG |
328 | extern int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg); |
329 | extern int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, | |
330 | struct tcphdr *th, unsigned len); | |
331 | extern int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, | |
332 | struct tcphdr *th, unsigned len); | |
333 | extern void tcp_rcv_space_adjust(struct sock *sk); | |
334 | extern void tcp_cleanup_rbuf(struct sock *sk, int copied); | |
335 | extern int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); | |
336 | extern void tcp_twsk_destructor(struct sock *sk); | |
337 | extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, | |
338 | struct pipe_inode_info *pipe, size_t len, | |
339 | unsigned int flags); | |
9c55e01c | 340 | |
463c84b9 ACM |
341 | static inline void tcp_dec_quickack_mode(struct sock *sk, |
342 | const unsigned int pkts) | |
1da177e4 | 343 | { |
463c84b9 | 344 | struct inet_connection_sock *icsk = inet_csk(sk); |
fc6415bc | 345 | |
463c84b9 ACM |
346 | if (icsk->icsk_ack.quick) { |
347 | if (pkts >= icsk->icsk_ack.quick) { | |
348 | icsk->icsk_ack.quick = 0; | |
fc6415bc | 349 | /* Leaving quickack mode we deflate ATO. */ |
463c84b9 | 350 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
fc6415bc | 351 | } else |
463c84b9 | 352 | icsk->icsk_ack.quick -= pkts; |
1da177e4 LT |
353 | } |
354 | } | |
355 | ||
bdf1ee5d IJ |
356 | #define TCP_ECN_OK 1 |
357 | #define TCP_ECN_QUEUE_CWR 2 | |
358 | #define TCP_ECN_DEMAND_CWR 4 | |
359 | ||
360 | static __inline__ void | |
361 | TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th) | |
362 | { | |
363 | if (sysctl_tcp_ecn && th->ece && th->cwr) | |
364 | inet_rsk(req)->ecn_ok = 1; | |
365 | } | |
366 | ||
fd2c3ef7 | 367 | enum tcp_tw_status { |
1da177e4 LT |
368 | TCP_TW_SUCCESS = 0, |
369 | TCP_TW_RST = 1, | |
370 | TCP_TW_ACK = 2, | |
371 | TCP_TW_SYN = 3 | |
372 | }; | |
373 | ||
374 | ||
53d3176b CG |
375 | extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
376 | struct sk_buff *skb, | |
377 | const struct tcphdr *th); | |
378 | extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb, | |
379 | struct request_sock *req, | |
380 | struct request_sock **prev); | |
381 | extern int tcp_child_process(struct sock *parent, struct sock *child, | |
382 | struct sk_buff *skb); | |
383 | extern int tcp_use_frto(struct sock *sk); | |
384 | extern void tcp_enter_frto(struct sock *sk); | |
385 | extern void tcp_enter_loss(struct sock *sk, int how); | |
386 | extern void tcp_clear_retrans(struct tcp_sock *tp); | |
387 | extern void tcp_update_metrics(struct sock *sk); | |
388 | extern void tcp_close(struct sock *sk, long timeout); | |
389 | extern unsigned int tcp_poll(struct file * file, struct socket *sock, | |
390 | struct poll_table_struct *wait); | |
391 | extern int tcp_getsockopt(struct sock *sk, int level, int optname, | |
392 | char __user *optval, int __user *optlen); | |
393 | extern int tcp_setsockopt(struct sock *sk, int level, int optname, | |
394 | char __user *optval, unsigned int optlen); | |
395 | extern int compat_tcp_getsockopt(struct sock *sk, int level, int optname, | |
396 | char __user *optval, int __user *optlen); | |
397 | extern int compat_tcp_setsockopt(struct sock *sk, int level, int optname, | |
398 | char __user *optval, unsigned int optlen); | |
399 | extern void tcp_set_keepalive(struct sock *sk, int val); | |
400 | extern void tcp_syn_ack_timeout(struct sock *sk, struct request_sock *req); | |
401 | extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, | |
402 | size_t len, int nonblock, int flags, int *addr_len); | |
403 | extern void tcp_parse_options(struct sk_buff *skb, | |
404 | struct tcp_options_received *opt_rx, u8 **hvpp, | |
405 | int estab); | |
406 | extern u8 *tcp_parse_md5sig_option(struct tcphdr *th); | |
7d5d5525 | 407 | |
1da177e4 LT |
408 | /* |
409 | * TCP v4 functions exported for the inet6 API | |
410 | */ | |
411 | ||
53d3176b CG |
412 | extern void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
413 | extern int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); | |
414 | extern struct sock * tcp_create_openreq_child(struct sock *sk, | |
415 | struct request_sock *req, | |
1da177e4 | 416 | struct sk_buff *skb); |
53d3176b CG |
417 | extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, |
418 | struct request_sock *req, | |
419 | struct dst_entry *dst); | |
420 | extern int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); | |
421 | extern int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, | |
422 | int addr_len); | |
423 | extern int tcp_connect(struct sock *sk); | |
424 | extern struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst, | |
425 | struct request_sock *req, | |
426 | struct request_values *rvp); | |
427 | extern int tcp_disconnect(struct sock *sk, int flags); | |
1da177e4 | 428 | |
1da177e4 | 429 | |
1da177e4 | 430 | /* From syncookies.c */ |
2051f11f | 431 | extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS]; |
1da177e4 LT |
432 | extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, |
433 | struct ip_options *opt); | |
434 | extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, | |
435 | __u16 *mss); | |
436 | ||
4dfc2817 | 437 | extern __u32 cookie_init_timestamp(struct request_sock *req); |
172d69e6 | 438 | extern bool cookie_check_timestamp(struct tcp_options_received *opt, bool *); |
4dfc2817 | 439 | |
c6aefafb GG |
440 | /* From net/ipv6/syncookies.c */ |
441 | extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); | |
442 | extern __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb, | |
443 | __u16 *mss); | |
444 | ||
1da177e4 LT |
445 | /* tcp_output.c */ |
446 | ||
9e412ba7 IJ |
447 | extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
448 | int nonagle); | |
449 | extern int tcp_may_send_now(struct sock *sk); | |
1da177e4 | 450 | extern int tcp_retransmit_skb(struct sock *, struct sk_buff *); |
f1ecd5d9 | 451 | extern void tcp_retransmit_timer(struct sock *sk); |
1da177e4 LT |
452 | extern void tcp_xmit_retransmit_queue(struct sock *); |
453 | extern void tcp_simple_retransmit(struct sock *); | |
454 | extern int tcp_trim_head(struct sock *, struct sk_buff *, u32); | |
6475be16 | 455 | extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int); |
1da177e4 LT |
456 | |
457 | extern void tcp_send_probe0(struct sock *); | |
458 | extern void tcp_send_partial(struct sock *); | |
53d3176b | 459 | extern int tcp_write_wakeup(struct sock *); |
1da177e4 | 460 | extern void tcp_send_fin(struct sock *sk); |
dd0fc66f | 461 | extern void tcp_send_active_reset(struct sock *sk, gfp_t priority); |
53d3176b | 462 | extern int tcp_send_synack(struct sock *); |
c1b4a7e6 | 463 | extern void tcp_push_one(struct sock *, unsigned int mss_now); |
1da177e4 LT |
464 | extern void tcp_send_ack(struct sock *sk); |
465 | extern void tcp_send_delayed_ack(struct sock *sk); | |
466 | ||
a762a980 DM |
467 | /* tcp_input.c */ |
468 | extern void tcp_cwnd_application_limited(struct sock *sk); | |
469 | ||
1da177e4 LT |
470 | /* tcp_timer.c */ |
471 | extern void tcp_init_xmit_timers(struct sock *); | |
463c84b9 ACM |
472 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
473 | { | |
474 | inet_csk_clear_xmit_timers(sk); | |
475 | } | |
1da177e4 | 476 | |
1da177e4 | 477 | extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
0c54b85f IJ |
478 | extern unsigned int tcp_current_mss(struct sock *sk); |
479 | ||
480 | /* Bound MSS / TSO packet size with the half of the window */ | |
481 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) | |
482 | { | |
01f83d69 AK |
483 | int cutoff; |
484 | ||
485 | /* When peer uses tiny windows, there is no use in packetizing | |
486 | * to sub-MSS pieces for the sake of SWS or making sure there | |
487 | * are enough packets in the pipe for fast recovery. | |
488 | * | |
489 | * On the other hand, for extremely large MSS devices, handling | |
490 | * smaller than MSS windows in this way does make sense. | |
491 | */ | |
492 | if (tp->max_window >= 512) | |
493 | cutoff = (tp->max_window >> 1); | |
494 | else | |
495 | cutoff = tp->max_window; | |
496 | ||
497 | if (cutoff && pktsize > cutoff) | |
498 | return max_t(int, cutoff, 68U - tp->tcp_header_len); | |
0c54b85f IJ |
499 | else |
500 | return pktsize; | |
501 | } | |
1da177e4 | 502 | |
17b085ea | 503 | /* tcp.c */ |
1da177e4 LT |
504 | extern void tcp_get_info(struct sock *, struct tcp_info *); |
505 | ||
506 | /* Read 'sendfile()'-style from a TCP socket */ | |
507 | typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *, | |
508 | unsigned int, size_t); | |
509 | extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, | |
510 | sk_read_actor_t recv_actor); | |
511 | ||
40efc6fa | 512 | extern void tcp_initialize_rcv_mss(struct sock *sk); |
1da177e4 | 513 | |
5d424d5a JH |
514 | extern int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
515 | extern int tcp_mss_to_mtu(struct sock *sk, int mss); | |
516 | extern void tcp_mtup_init(struct sock *sk); | |
9ad7c049 | 517 | extern void tcp_valid_rtt_meas(struct sock *sk, u32 seq_rtt); |
5d424d5a | 518 | |
f1ecd5d9 DL |
519 | static inline void tcp_bound_rto(const struct sock *sk) |
520 | { | |
521 | if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) | |
522 | inet_csk(sk)->icsk_rto = TCP_RTO_MAX; | |
523 | } | |
524 | ||
525 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) | |
526 | { | |
527 | return (tp->srtt >> 3) + tp->rttvar; | |
528 | } | |
529 | ||
40efc6fa | 530 | static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
1da177e4 LT |
531 | { |
532 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | | |
533 | ntohl(TCP_FLAG_ACK) | | |
534 | snd_wnd); | |
535 | } | |
536 | ||
40efc6fa | 537 | static inline void tcp_fast_path_on(struct tcp_sock *tp) |
1da177e4 LT |
538 | { |
539 | __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); | |
540 | } | |
541 | ||
9e412ba7 | 542 | static inline void tcp_fast_path_check(struct sock *sk) |
1da177e4 | 543 | { |
9e412ba7 IJ |
544 | struct tcp_sock *tp = tcp_sk(sk); |
545 | ||
b03efcfb | 546 | if (skb_queue_empty(&tp->out_of_order_queue) && |
1da177e4 LT |
547 | tp->rcv_wnd && |
548 | atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && | |
549 | !tp->urg_data) | |
550 | tcp_fast_path_on(tp); | |
551 | } | |
552 | ||
0c266898 SS |
553 | /* Compute the actual rto_min value */ |
554 | static inline u32 tcp_rto_min(struct sock *sk) | |
555 | { | |
556 | struct dst_entry *dst = __sk_dst_get(sk); | |
557 | u32 rto_min = TCP_RTO_MIN; | |
558 | ||
559 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) | |
560 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); | |
561 | return rto_min; | |
562 | } | |
563 | ||
1da177e4 LT |
564 | /* Compute the actual receive window we are currently advertising. |
565 | * Rcv_nxt can be after the window if our peer push more data | |
566 | * than the offered window. | |
567 | */ | |
40efc6fa | 568 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
1da177e4 LT |
569 | { |
570 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; | |
571 | ||
572 | if (win < 0) | |
573 | win = 0; | |
574 | return (u32) win; | |
575 | } | |
576 | ||
577 | /* Choose a new window, without checks for shrinking, and without | |
578 | * scaling applied to the result. The caller does these things | |
579 | * if necessary. This is a "raw" window selection. | |
580 | */ | |
53d3176b | 581 | extern u32 __tcp_select_window(struct sock *sk); |
1da177e4 LT |
582 | |
583 | /* TCP timestamps are only 32-bits, this causes a slight | |
584 | * complication on 64-bit systems since we store a snapshot | |
31f34269 SH |
585 | * of jiffies in the buffer control blocks below. We decided |
586 | * to use only the low 32-bits of jiffies and hide the ugly | |
1da177e4 LT |
587 | * casts with the following macro. |
588 | */ | |
589 | #define tcp_time_stamp ((__u32)(jiffies)) | |
590 | ||
a3433f35 CG |
591 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
592 | ||
593 | #define TCPHDR_FIN 0x01 | |
594 | #define TCPHDR_SYN 0x02 | |
595 | #define TCPHDR_RST 0x04 | |
596 | #define TCPHDR_PSH 0x08 | |
597 | #define TCPHDR_ACK 0x10 | |
598 | #define TCPHDR_URG 0x20 | |
599 | #define TCPHDR_ECE 0x40 | |
600 | #define TCPHDR_CWR 0x80 | |
601 | ||
caa20d9a | 602 | /* This is what the send packet queuing engine uses to pass |
f86586fa ED |
603 | * TCP per-packet control information to the transmission code. |
604 | * We also store the host-order sequence numbers in here too. | |
605 | * This is 44 bytes if IPV6 is enabled. | |
606 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. | |
1da177e4 LT |
607 | */ |
608 | struct tcp_skb_cb { | |
609 | union { | |
610 | struct inet_skb_parm h4; | |
611 | #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) | |
612 | struct inet6_skb_parm h6; | |
613 | #endif | |
614 | } header; /* For incoming frames */ | |
615 | __u32 seq; /* Starting sequence number */ | |
616 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ | |
617 | __u32 when; /* used to compute rtt's */ | |
618 | __u8 flags; /* TCP header flags. */ | |
1da177e4 LT |
619 | __u8 sacked; /* State flags for SACK/FACK. */ |
620 | #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ | |
621 | #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ | |
622 | #define TCPCB_LOST 0x04 /* SKB is lost */ | |
623 | #define TCPCB_TAGBITS 0x07 /* All tag bits */ | |
624 | ||
625 | #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ | |
626 | #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS) | |
627 | ||
1da177e4 LT |
628 | __u32 ack_seq; /* Sequence number ACK'd */ |
629 | }; | |
630 | ||
631 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) | |
632 | ||
1da177e4 LT |
633 | /* Due to TSO, an SKB can be composed of multiple actual |
634 | * packets. To keep these tracked properly, we use this. | |
635 | */ | |
636 | static inline int tcp_skb_pcount(const struct sk_buff *skb) | |
637 | { | |
7967168c | 638 | return skb_shinfo(skb)->gso_segs; |
1da177e4 LT |
639 | } |
640 | ||
641 | /* This is valid iff tcp_skb_pcount() > 1. */ | |
642 | static inline int tcp_skb_mss(const struct sk_buff *skb) | |
643 | { | |
7967168c | 644 | return skb_shinfo(skb)->gso_size; |
1da177e4 LT |
645 | } |
646 | ||
317a76f9 SH |
647 | /* Events passed to congestion control interface */ |
648 | enum tcp_ca_event { | |
649 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ | |
650 | CA_EVENT_CWND_RESTART, /* congestion window restart */ | |
651 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ | |
652 | CA_EVENT_FRTO, /* fast recovery timeout */ | |
653 | CA_EVENT_LOSS, /* loss timeout */ | |
654 | CA_EVENT_FAST_ACK, /* in sequence ack */ | |
655 | CA_EVENT_SLOW_ACK, /* other ack */ | |
656 | }; | |
657 | ||
658 | /* | |
659 | * Interface for adding new TCP congestion control handlers | |
660 | */ | |
661 | #define TCP_CA_NAME_MAX 16 | |
3ff825b2 SH |
662 | #define TCP_CA_MAX 128 |
663 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) | |
664 | ||
164891aa SH |
665 | #define TCP_CONG_NON_RESTRICTED 0x1 |
666 | #define TCP_CONG_RTT_STAMP 0x2 | |
667 | ||
317a76f9 SH |
668 | struct tcp_congestion_ops { |
669 | struct list_head list; | |
164891aa | 670 | unsigned long flags; |
317a76f9 SH |
671 | |
672 | /* initialize private data (optional) */ | |
6687e988 | 673 | void (*init)(struct sock *sk); |
317a76f9 | 674 | /* cleanup private data (optional) */ |
6687e988 | 675 | void (*release)(struct sock *sk); |
317a76f9 SH |
676 | |
677 | /* return slow start threshold (required) */ | |
6687e988 | 678 | u32 (*ssthresh)(struct sock *sk); |
317a76f9 | 679 | /* lower bound for congestion window (optional) */ |
72dc5b92 | 680 | u32 (*min_cwnd)(const struct sock *sk); |
317a76f9 | 681 | /* do new cwnd calculation (required) */ |
c3a05c60 | 682 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight); |
317a76f9 | 683 | /* call before changing ca_state (optional) */ |
6687e988 | 684 | void (*set_state)(struct sock *sk, u8 new_state); |
317a76f9 | 685 | /* call when cwnd event occurs (optional) */ |
6687e988 | 686 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
317a76f9 | 687 | /* new value of cwnd after loss (optional) */ |
6687e988 | 688 | u32 (*undo_cwnd)(struct sock *sk); |
317a76f9 | 689 | /* hook for packet ack accounting (optional) */ |
30cfd0ba | 690 | void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us); |
73c1f4a0 | 691 | /* get info for inet_diag (optional) */ |
6687e988 | 692 | void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb); |
317a76f9 SH |
693 | |
694 | char name[TCP_CA_NAME_MAX]; | |
695 | struct module *owner; | |
696 | }; | |
697 | ||
698 | extern int tcp_register_congestion_control(struct tcp_congestion_ops *type); | |
699 | extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); | |
700 | ||
6687e988 ACM |
701 | extern void tcp_init_congestion_control(struct sock *sk); |
702 | extern void tcp_cleanup_congestion_control(struct sock *sk); | |
317a76f9 SH |
703 | extern int tcp_set_default_congestion_control(const char *name); |
704 | extern void tcp_get_default_congestion_control(char *name); | |
3ff825b2 | 705 | extern void tcp_get_available_congestion_control(char *buf, size_t len); |
ce7bc3bf SH |
706 | extern void tcp_get_allowed_congestion_control(char *buf, size_t len); |
707 | extern int tcp_set_allowed_congestion_control(char *allowed); | |
6687e988 | 708 | extern int tcp_set_congestion_control(struct sock *sk, const char *name); |
40efc6fa | 709 | extern void tcp_slow_start(struct tcp_sock *tp); |
758ce5c8 | 710 | extern void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w); |
317a76f9 | 711 | |
5f8ef48d | 712 | extern struct tcp_congestion_ops tcp_init_congestion_ops; |
6687e988 | 713 | extern u32 tcp_reno_ssthresh(struct sock *sk); |
c3a05c60 | 714 | extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight); |
72dc5b92 | 715 | extern u32 tcp_reno_min_cwnd(const struct sock *sk); |
a8acfbac | 716 | extern struct tcp_congestion_ops tcp_reno; |
317a76f9 | 717 | |
6687e988 | 718 | static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state) |
317a76f9 | 719 | { |
6687e988 ACM |
720 | struct inet_connection_sock *icsk = inet_csk(sk); |
721 | ||
722 | if (icsk->icsk_ca_ops->set_state) | |
723 | icsk->icsk_ca_ops->set_state(sk, ca_state); | |
724 | icsk->icsk_ca_state = ca_state; | |
317a76f9 SH |
725 | } |
726 | ||
6687e988 | 727 | static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) |
317a76f9 | 728 | { |
6687e988 ACM |
729 | const struct inet_connection_sock *icsk = inet_csk(sk); |
730 | ||
731 | if (icsk->icsk_ca_ops->cwnd_event) | |
732 | icsk->icsk_ca_ops->cwnd_event(sk, event); | |
317a76f9 SH |
733 | } |
734 | ||
e60402d0 IJ |
735 | /* These functions determine how the current flow behaves in respect of SACK |
736 | * handling. SACK is negotiated with the peer, and therefore it can vary | |
737 | * between different flows. | |
738 | * | |
739 | * tcp_is_sack - SACK enabled | |
740 | * tcp_is_reno - No SACK | |
741 | * tcp_is_fack - FACK enabled, implies SACK enabled | |
742 | */ | |
743 | static inline int tcp_is_sack(const struct tcp_sock *tp) | |
744 | { | |
745 | return tp->rx_opt.sack_ok; | |
746 | } | |
747 | ||
748 | static inline int tcp_is_reno(const struct tcp_sock *tp) | |
749 | { | |
750 | return !tcp_is_sack(tp); | |
751 | } | |
752 | ||
753 | static inline int tcp_is_fack(const struct tcp_sock *tp) | |
754 | { | |
755 | return tp->rx_opt.sack_ok & 2; | |
756 | } | |
757 | ||
758 | static inline void tcp_enable_fack(struct tcp_sock *tp) | |
759 | { | |
760 | tp->rx_opt.sack_ok |= 2; | |
761 | } | |
762 | ||
83ae4088 IJ |
763 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
764 | { | |
765 | return tp->sacked_out + tp->lost_out; | |
766 | } | |
767 | ||
1da177e4 LT |
768 | /* This determines how many packets are "in the network" to the best |
769 | * of our knowledge. In many cases it is conservative, but where | |
770 | * detailed information is available from the receiver (via SACK | |
771 | * blocks etc.) we can make more aggressive calculations. | |
772 | * | |
773 | * Use this for decisions involving congestion control, use just | |
774 | * tp->packets_out to determine if the send queue is empty or not. | |
775 | * | |
776 | * Read this equation as: | |
777 | * | |
778 | * "Packets sent once on transmission queue" MINUS | |
779 | * "Packets left network, but not honestly ACKed yet" PLUS | |
780 | * "Packets fast retransmitted" | |
781 | */ | |
40efc6fa | 782 | static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
1da177e4 | 783 | { |
83ae4088 | 784 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
1da177e4 LT |
785 | } |
786 | ||
0b6a05c1 IJ |
787 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
788 | ||
789 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) | |
790 | { | |
791 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; | |
792 | } | |
793 | ||
1da177e4 LT |
794 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
795 | * The exception is rate halving phase, when cwnd is decreasing towards | |
796 | * ssthresh. | |
797 | */ | |
6687e988 | 798 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
1da177e4 | 799 | { |
6687e988 ACM |
800 | const struct tcp_sock *tp = tcp_sk(sk); |
801 | if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery)) | |
1da177e4 LT |
802 | return tp->snd_ssthresh; |
803 | else | |
804 | return max(tp->snd_ssthresh, | |
805 | ((tp->snd_cwnd >> 1) + | |
806 | (tp->snd_cwnd >> 2))); | |
807 | } | |
808 | ||
b9c4595b IJ |
809 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
810 | #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) | |
1da177e4 | 811 | |
3cfe3baa | 812 | extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh); |
1da177e4 LT |
813 | extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst); |
814 | ||
815 | /* Slow start with delack produces 3 packets of burst, so that | |
dd9e0dda JH |
816 | * it is safe "de facto". This will be the default - same as |
817 | * the default reordering threshold - but if reordering increases, | |
818 | * we must be able to allow cwnd to burst at least this much in order | |
819 | * to not pull it back when holes are filled. | |
1da177e4 LT |
820 | */ |
821 | static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp) | |
822 | { | |
dd9e0dda | 823 | return tp->reordering; |
1da177e4 LT |
824 | } |
825 | ||
90840def IJ |
826 | /* Returns end sequence number of the receiver's advertised window */ |
827 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) | |
828 | { | |
829 | return tp->snd_una + tp->snd_wnd; | |
830 | } | |
cea14e0e | 831 | extern int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight); |
f4805ede | 832 | |
c1bd24b7 | 833 | static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss, |
40efc6fa | 834 | const struct sk_buff *skb) |
1da177e4 LT |
835 | { |
836 | if (skb->len < mss) | |
837 | tp->snd_sml = TCP_SKB_CB(skb)->end_seq; | |
838 | } | |
839 | ||
9e412ba7 | 840 | static inline void tcp_check_probe_timer(struct sock *sk) |
1da177e4 | 841 | { |
9e412ba7 | 842 | struct tcp_sock *tp = tcp_sk(sk); |
463c84b9 | 843 | const struct inet_connection_sock *icsk = inet_csk(sk); |
9e412ba7 | 844 | |
463c84b9 | 845 | if (!tp->packets_out && !icsk->icsk_pending) |
3f421baa ACM |
846 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
847 | icsk->icsk_rto, TCP_RTO_MAX); | |
1da177e4 LT |
848 | } |
849 | ||
ee7537b6 | 850 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
851 | { |
852 | tp->snd_wl1 = seq; | |
853 | } | |
854 | ||
ee7537b6 | 855 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
856 | { |
857 | tp->snd_wl1 = seq; | |
858 | } | |
859 | ||
1da177e4 LT |
860 | /* |
861 | * Calculate(/check) TCP checksum | |
862 | */ | |
ba7808ea FD |
863 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
864 | __be32 daddr, __wsum base) | |
1da177e4 LT |
865 | { |
866 | return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); | |
867 | } | |
868 | ||
b51655b9 | 869 | static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb) |
1da177e4 | 870 | { |
fb286bb2 | 871 | return __skb_checksum_complete(skb); |
1da177e4 LT |
872 | } |
873 | ||
40efc6fa | 874 | static inline int tcp_checksum_complete(struct sk_buff *skb) |
1da177e4 | 875 | { |
60476372 | 876 | return !skb_csum_unnecessary(skb) && |
1da177e4 LT |
877 | __tcp_checksum_complete(skb); |
878 | } | |
879 | ||
880 | /* Prequeue for VJ style copy to user, combined with checksumming. */ | |
881 | ||
40efc6fa | 882 | static inline void tcp_prequeue_init(struct tcp_sock *tp) |
1da177e4 LT |
883 | { |
884 | tp->ucopy.task = NULL; | |
885 | tp->ucopy.len = 0; | |
886 | tp->ucopy.memory = 0; | |
887 | skb_queue_head_init(&tp->ucopy.prequeue); | |
97fc2f08 CL |
888 | #ifdef CONFIG_NET_DMA |
889 | tp->ucopy.dma_chan = NULL; | |
890 | tp->ucopy.wakeup = 0; | |
891 | tp->ucopy.pinned_list = NULL; | |
892 | tp->ucopy.dma_cookie = 0; | |
893 | #endif | |
1da177e4 LT |
894 | } |
895 | ||
896 | /* Packet is added to VJ-style prequeue for processing in process | |
897 | * context, if a reader task is waiting. Apparently, this exciting | |
898 | * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93) | |
899 | * failed somewhere. Latency? Burstiness? Well, at least now we will | |
900 | * see, why it failed. 8)8) --ANK | |
901 | * | |
902 | * NOTE: is this not too big to inline? | |
903 | */ | |
40efc6fa | 904 | static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
905 | { |
906 | struct tcp_sock *tp = tcp_sk(sk); | |
907 | ||
f5f8d86b ED |
908 | if (sysctl_tcp_low_latency || !tp->ucopy.task) |
909 | return 0; | |
910 | ||
911 | __skb_queue_tail(&tp->ucopy.prequeue, skb); | |
912 | tp->ucopy.memory += skb->truesize; | |
913 | if (tp->ucopy.memory > sk->sk_rcvbuf) { | |
914 | struct sk_buff *skb1; | |
915 | ||
916 | BUG_ON(sock_owned_by_user(sk)); | |
917 | ||
918 | while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) { | |
919 | sk_backlog_rcv(sk, skb1); | |
920 | NET_INC_STATS_BH(sock_net(sk), | |
921 | LINUX_MIB_TCPPREQUEUEDROPPED); | |
1da177e4 | 922 | } |
f5f8d86b ED |
923 | |
924 | tp->ucopy.memory = 0; | |
925 | } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { | |
aa395145 | 926 | wake_up_interruptible_sync_poll(sk_sleep(sk), |
7aedec2a | 927 | POLLIN | POLLRDNORM | POLLRDBAND); |
f5f8d86b ED |
928 | if (!inet_csk_ack_scheduled(sk)) |
929 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, | |
22f6dacd | 930 | (3 * tcp_rto_min(sk)) / 4, |
f5f8d86b | 931 | TCP_RTO_MAX); |
1da177e4 | 932 | } |
f5f8d86b | 933 | return 1; |
1da177e4 LT |
934 | } |
935 | ||
936 | ||
937 | #undef STATE_TRACE | |
938 | ||
939 | #ifdef STATE_TRACE | |
940 | static const char *statename[]={ | |
941 | "Unused","Established","Syn Sent","Syn Recv", | |
942 | "Fin Wait 1","Fin Wait 2","Time Wait", "Close", | |
943 | "Close Wait","Last ACK","Listen","Closing" | |
944 | }; | |
945 | #endif | |
490d5046 | 946 | extern void tcp_set_state(struct sock *sk, int state); |
1da177e4 | 947 | |
4ac02bab | 948 | extern void tcp_done(struct sock *sk); |
1da177e4 | 949 | |
40efc6fa | 950 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
1da177e4 LT |
951 | { |
952 | rx_opt->dsack = 0; | |
1da177e4 LT |
953 | rx_opt->num_sacks = 0; |
954 | } | |
955 | ||
1da177e4 LT |
956 | /* Determine a window scaling and initial window to offer. */ |
957 | extern void tcp_select_initial_window(int __space, __u32 mss, | |
958 | __u32 *rcv_wnd, __u32 *window_clamp, | |
31d12926 | 959 | int wscale_ok, __u8 *rcv_wscale, |
960 | __u32 init_rcv_wnd); | |
1da177e4 LT |
961 | |
962 | static inline int tcp_win_from_space(int space) | |
963 | { | |
964 | return sysctl_tcp_adv_win_scale<=0 ? | |
965 | (space>>(-sysctl_tcp_adv_win_scale)) : | |
966 | space - (space>>sysctl_tcp_adv_win_scale); | |
967 | } | |
968 | ||
969 | /* Note: caller must be prepared to deal with negative returns */ | |
970 | static inline int tcp_space(const struct sock *sk) | |
971 | { | |
972 | return tcp_win_from_space(sk->sk_rcvbuf - | |
973 | atomic_read(&sk->sk_rmem_alloc)); | |
974 | } | |
975 | ||
976 | static inline int tcp_full_space(const struct sock *sk) | |
977 | { | |
978 | return tcp_win_from_space(sk->sk_rcvbuf); | |
979 | } | |
980 | ||
40efc6fa SH |
981 | static inline void tcp_openreq_init(struct request_sock *req, |
982 | struct tcp_options_received *rx_opt, | |
983 | struct sk_buff *skb) | |
1da177e4 | 984 | { |
2e6599cb ACM |
985 | struct inet_request_sock *ireq = inet_rsk(req); |
986 | ||
1da177e4 | 987 | req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */ |
4dfc2817 | 988 | req->cookie_ts = 0; |
2e6599cb | 989 | tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq; |
1da177e4 LT |
990 | req->mss = rx_opt->mss_clamp; |
991 | req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0; | |
2e6599cb ACM |
992 | ireq->tstamp_ok = rx_opt->tstamp_ok; |
993 | ireq->sack_ok = rx_opt->sack_ok; | |
994 | ireq->snd_wscale = rx_opt->snd_wscale; | |
995 | ireq->wscale_ok = rx_opt->wscale_ok; | |
996 | ireq->acked = 0; | |
997 | ireq->ecn_ok = 0; | |
aa8223c7 | 998 | ireq->rmt_port = tcp_hdr(skb)->source; |
a3116ac5 | 999 | ireq->loc_port = tcp_hdr(skb)->dest; |
1da177e4 LT |
1000 | } |
1001 | ||
5c52ba17 | 1002 | extern void tcp_enter_memory_pressure(struct sock *sk); |
1da177e4 | 1003 | |
1da177e4 LT |
1004 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
1005 | { | |
1006 | return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl; | |
1007 | } | |
1008 | ||
1009 | static inline int keepalive_time_when(const struct tcp_sock *tp) | |
1010 | { | |
1011 | return tp->keepalive_time ? : sysctl_tcp_keepalive_time; | |
1012 | } | |
1013 | ||
df19a626 ED |
1014 | static inline int keepalive_probes(const struct tcp_sock *tp) |
1015 | { | |
1016 | return tp->keepalive_probes ? : sysctl_tcp_keepalive_probes; | |
1017 | } | |
1018 | ||
6c37e5de FL |
1019 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
1020 | { | |
1021 | const struct inet_connection_sock *icsk = &tp->inet_conn; | |
1022 | ||
1023 | return min_t(u32, tcp_time_stamp - icsk->icsk_ack.lrcvtime, | |
1024 | tcp_time_stamp - tp->rcv_tstamp); | |
1025 | } | |
1026 | ||
463c84b9 | 1027 | static inline int tcp_fin_time(const struct sock *sk) |
1da177e4 | 1028 | { |
463c84b9 ACM |
1029 | int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout; |
1030 | const int rto = inet_csk(sk)->icsk_rto; | |
1da177e4 | 1031 | |
463c84b9 ACM |
1032 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
1033 | fin_timeout = (rto << 2) - (rto >> 1); | |
1da177e4 LT |
1034 | |
1035 | return fin_timeout; | |
1036 | } | |
1037 | ||
c887e6d2 IJ |
1038 | static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, |
1039 | int paws_win) | |
1da177e4 | 1040 | { |
c887e6d2 IJ |
1041 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
1042 | return 1; | |
1043 | if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)) | |
1044 | return 1; | |
bc2ce894 ED |
1045 | /* |
1046 | * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, | |
1047 | * then following tcp messages have valid values. Ignore 0 value, | |
1048 | * or else 'negative' tsval might forbid us to accept their packets. | |
1049 | */ | |
1050 | if (!rx_opt->ts_recent) | |
1051 | return 1; | |
c887e6d2 IJ |
1052 | return 0; |
1053 | } | |
1054 | ||
1055 | static inline int tcp_paws_reject(const struct tcp_options_received *rx_opt, | |
1056 | int rst) | |
1057 | { | |
1058 | if (tcp_paws_check(rx_opt, 0)) | |
1da177e4 LT |
1059 | return 0; |
1060 | ||
1061 | /* RST segments are not recommended to carry timestamp, | |
1062 | and, if they do, it is recommended to ignore PAWS because | |
1063 | "their cleanup function should take precedence over timestamps." | |
1064 | Certainly, it is mistake. It is necessary to understand the reasons | |
1065 | of this constraint to relax it: if peer reboots, clock may go | |
1066 | out-of-sync and half-open connections will not be reset. | |
1067 | Actually, the problem would be not existing if all | |
1068 | the implementations followed draft about maintaining clock | |
1069 | via reboots. Linux-2.2 DOES NOT! | |
1070 | ||
1071 | However, we can relax time bounds for RST segments to MSL. | |
1072 | */ | |
9d729f72 | 1073 | if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) |
1da177e4 LT |
1074 | return 0; |
1075 | return 1; | |
1076 | } | |
1077 | ||
a9c19329 | 1078 | static inline void tcp_mib_init(struct net *net) |
1da177e4 LT |
1079 | { |
1080 | /* See RFC 2012 */ | |
cf1100a7 PE |
1081 | TCP_ADD_STATS_USER(net, TCP_MIB_RTOALGORITHM, 1); |
1082 | TCP_ADD_STATS_USER(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); | |
1083 | TCP_ADD_STATS_USER(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); | |
1084 | TCP_ADD_STATS_USER(net, TCP_MIB_MAXCONN, -1); | |
1da177e4 LT |
1085 | } |
1086 | ||
5af4ec23 | 1087 | /* from STCP */ |
ef9da47c | 1088 | static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) |
0800f170 | 1089 | { |
6a438bbe SH |
1090 | tp->lost_skb_hint = NULL; |
1091 | tp->scoreboard_skb_hint = NULL; | |
ef9da47c IJ |
1092 | } |
1093 | ||
1094 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) | |
1095 | { | |
1096 | tcp_clear_retrans_hints_partial(tp); | |
6a438bbe | 1097 | tp->retransmit_skb_hint = NULL; |
b7689205 IJ |
1098 | } |
1099 | ||
cfb6eeb4 YH |
1100 | /* MD5 Signature */ |
1101 | struct crypto_hash; | |
1102 | ||
1103 | /* - key database */ | |
1104 | struct tcp_md5sig_key { | |
1105 | u8 *key; | |
1106 | u8 keylen; | |
1107 | }; | |
1108 | ||
1109 | struct tcp4_md5sig_key { | |
f8ab18d2 | 1110 | struct tcp_md5sig_key base; |
cfb6eeb4 YH |
1111 | __be32 addr; |
1112 | }; | |
1113 | ||
1114 | struct tcp6_md5sig_key { | |
f8ab18d2 | 1115 | struct tcp_md5sig_key base; |
cfb6eeb4 YH |
1116 | #if 0 |
1117 | u32 scope_id; /* XXX */ | |
1118 | #endif | |
1119 | struct in6_addr addr; | |
1120 | }; | |
1121 | ||
1122 | /* - sock block */ | |
1123 | struct tcp_md5sig_info { | |
1124 | struct tcp4_md5sig_key *keys4; | |
1125 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
1126 | struct tcp6_md5sig_key *keys6; | |
1127 | u32 entries6; | |
1128 | u32 alloced6; | |
1129 | #endif | |
1130 | u32 entries4; | |
1131 | u32 alloced4; | |
1132 | }; | |
1133 | ||
1134 | /* - pseudo header */ | |
1135 | struct tcp4_pseudohdr { | |
1136 | __be32 saddr; | |
1137 | __be32 daddr; | |
1138 | __u8 pad; | |
1139 | __u8 protocol; | |
1140 | __be16 len; | |
1141 | }; | |
1142 | ||
1143 | struct tcp6_pseudohdr { | |
1144 | struct in6_addr saddr; | |
1145 | struct in6_addr daddr; | |
1146 | __be32 len; | |
1147 | __be32 protocol; /* including padding */ | |
1148 | }; | |
1149 | ||
1150 | union tcp_md5sum_block { | |
1151 | struct tcp4_pseudohdr ip4; | |
1152 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
1153 | struct tcp6_pseudohdr ip6; | |
1154 | #endif | |
1155 | }; | |
1156 | ||
1157 | /* - pool: digest algorithm, hash description and scratch buffer */ | |
1158 | struct tcp_md5sig_pool { | |
1159 | struct hash_desc md5_desc; | |
1160 | union tcp_md5sum_block md5_blk; | |
1161 | }; | |
1162 | ||
cfb6eeb4 | 1163 | /* - functions */ |
53d3176b CG |
1164 | extern int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key, |
1165 | struct sock *sk, struct request_sock *req, | |
1166 | struct sk_buff *skb); | |
1167 | extern struct tcp_md5sig_key * tcp_v4_md5_lookup(struct sock *sk, | |
1168 | struct sock *addr_sk); | |
1169 | extern int tcp_v4_md5_do_add(struct sock *sk, __be32 addr, u8 *newkey, | |
1170 | u8 newkeylen); | |
1171 | extern int tcp_v4_md5_do_del(struct sock *sk, __be32 addr); | |
cfb6eeb4 | 1172 | |
9501f972 YH |
1173 | #ifdef CONFIG_TCP_MD5SIG |
1174 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_keylen ? \ | |
1175 | &(struct tcp_md5sig_key) { \ | |
1176 | .key = (twsk)->tw_md5_key, \ | |
1177 | .keylen = (twsk)->tw_md5_keylen, \ | |
1178 | } : NULL) | |
1179 | #else | |
1180 | #define tcp_twsk_md5_key(twsk) NULL | |
1181 | #endif | |
1182 | ||
7d720c3e | 1183 | extern struct tcp_md5sig_pool * __percpu *tcp_alloc_md5sig_pool(struct sock *); |
53d3176b | 1184 | extern void tcp_free_md5sig_pool(void); |
cfb6eeb4 | 1185 | |
35790c04 | 1186 | extern struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); |
53d3176b | 1187 | extern void tcp_put_md5sig_pool(void); |
35790c04 | 1188 | |
49a72dfb AL |
1189 | extern int tcp_md5_hash_header(struct tcp_md5sig_pool *, struct tcphdr *); |
1190 | extern int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, struct sk_buff *, | |
1191 | unsigned header_len); | |
1192 | extern int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, | |
1193 | struct tcp_md5sig_key *key); | |
cfb6eeb4 | 1194 | |
fe067e8a DM |
1195 | /* write queue abstraction */ |
1196 | static inline void tcp_write_queue_purge(struct sock *sk) | |
1197 | { | |
1198 | struct sk_buff *skb; | |
1199 | ||
1200 | while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) | |
3ab224be HA |
1201 | sk_wmem_free_skb(sk, skb); |
1202 | sk_mem_reclaim(sk); | |
8818a9d8 | 1203 | tcp_clear_all_retrans_hints(tcp_sk(sk)); |
fe067e8a DM |
1204 | } |
1205 | ||
1206 | static inline struct sk_buff *tcp_write_queue_head(struct sock *sk) | |
1207 | { | |
cd07a8ea | 1208 | return skb_peek(&sk->sk_write_queue); |
fe067e8a DM |
1209 | } |
1210 | ||
1211 | static inline struct sk_buff *tcp_write_queue_tail(struct sock *sk) | |
1212 | { | |
cd07a8ea | 1213 | return skb_peek_tail(&sk->sk_write_queue); |
fe067e8a DM |
1214 | } |
1215 | ||
1216 | static inline struct sk_buff *tcp_write_queue_next(struct sock *sk, struct sk_buff *skb) | |
1217 | { | |
cd07a8ea | 1218 | return skb_queue_next(&sk->sk_write_queue, skb); |
fe067e8a DM |
1219 | } |
1220 | ||
832d11c5 IJ |
1221 | static inline struct sk_buff *tcp_write_queue_prev(struct sock *sk, struct sk_buff *skb) |
1222 | { | |
1223 | return skb_queue_prev(&sk->sk_write_queue, skb); | |
1224 | } | |
1225 | ||
fe067e8a | 1226 | #define tcp_for_write_queue(skb, sk) \ |
cd07a8ea | 1227 | skb_queue_walk(&(sk)->sk_write_queue, skb) |
fe067e8a DM |
1228 | |
1229 | #define tcp_for_write_queue_from(skb, sk) \ | |
cd07a8ea | 1230 | skb_queue_walk_from(&(sk)->sk_write_queue, skb) |
fe067e8a | 1231 | |
234b6860 | 1232 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
cd07a8ea | 1233 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
234b6860 | 1234 | |
fe067e8a DM |
1235 | static inline struct sk_buff *tcp_send_head(struct sock *sk) |
1236 | { | |
1237 | return sk->sk_send_head; | |
1238 | } | |
1239 | ||
cd07a8ea DM |
1240 | static inline bool tcp_skb_is_last(const struct sock *sk, |
1241 | const struct sk_buff *skb) | |
1242 | { | |
1243 | return skb_queue_is_last(&sk->sk_write_queue, skb); | |
1244 | } | |
1245 | ||
fe067e8a DM |
1246 | static inline void tcp_advance_send_head(struct sock *sk, struct sk_buff *skb) |
1247 | { | |
cd07a8ea | 1248 | if (tcp_skb_is_last(sk, skb)) |
fe067e8a | 1249 | sk->sk_send_head = NULL; |
cd07a8ea DM |
1250 | else |
1251 | sk->sk_send_head = tcp_write_queue_next(sk, skb); | |
fe067e8a DM |
1252 | } |
1253 | ||
1254 | static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked) | |
1255 | { | |
1256 | if (sk->sk_send_head == skb_unlinked) | |
1257 | sk->sk_send_head = NULL; | |
1258 | } | |
1259 | ||
1260 | static inline void tcp_init_send_head(struct sock *sk) | |
1261 | { | |
1262 | sk->sk_send_head = NULL; | |
1263 | } | |
1264 | ||
1265 | static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) | |
1266 | { | |
1267 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1268 | } | |
1269 | ||
1270 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) | |
1271 | { | |
1272 | __tcp_add_write_queue_tail(sk, skb); | |
1273 | ||
1274 | /* Queue it, remembering where we must start sending. */ | |
6859d494 | 1275 | if (sk->sk_send_head == NULL) { |
fe067e8a | 1276 | sk->sk_send_head = skb; |
6859d494 IJ |
1277 | |
1278 | if (tcp_sk(sk)->highest_sack == NULL) | |
1279 | tcp_sk(sk)->highest_sack = skb; | |
1280 | } | |
fe067e8a DM |
1281 | } |
1282 | ||
1283 | static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb) | |
1284 | { | |
1285 | __skb_queue_head(&sk->sk_write_queue, skb); | |
1286 | } | |
1287 | ||
1288 | /* Insert buff after skb on the write queue of sk. */ | |
1289 | static inline void tcp_insert_write_queue_after(struct sk_buff *skb, | |
1290 | struct sk_buff *buff, | |
1291 | struct sock *sk) | |
1292 | { | |
7de6c033 | 1293 | __skb_queue_after(&sk->sk_write_queue, skb, buff); |
fe067e8a DM |
1294 | } |
1295 | ||
43f59c89 | 1296 | /* Insert new before skb on the write queue of sk. */ |
fe067e8a DM |
1297 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
1298 | struct sk_buff *skb, | |
1299 | struct sock *sk) | |
1300 | { | |
43f59c89 | 1301 | __skb_queue_before(&sk->sk_write_queue, skb, new); |