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 | ||
1da177e4 LT |
21 | #define FASTRETRANS_DEBUG 1 |
22 | ||
1da177e4 LT |
23 | #include <linux/list.h> |
24 | #include <linux/tcp.h> | |
187f1882 | 25 | #include <linux/bug.h> |
1da177e4 LT |
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 | 47 | #include <linux/seq_file.h> |
180d8cd9 | 48 | #include <linux/memcontrol.h> |
1da177e4 | 49 | |
6e04e021 | 50 | extern struct inet_hashinfo tcp_hashinfo; |
1da177e4 | 51 | |
dd24c001 | 52 | extern struct percpu_counter tcp_orphan_count; |
1da177e4 | 53 | extern void tcp_time_wait(struct sock *sk, int state, int timeo); |
1da177e4 | 54 | |
1da177e4 | 55 | #define MAX_TCP_HEADER (128 + MAX_HEADER) |
33ad798c | 56 | #define MAX_TCP_OPTION_SPACE 40 |
1da177e4 LT |
57 | |
58 | /* | |
59 | * Never offer a window over 32767 without using window scaling. Some | |
60 | * poor stacks do signed 16bit maths! | |
61 | */ | |
62 | #define MAX_TCP_WINDOW 32767U | |
63 | ||
356f0398 ND |
64 | /* Offer an initial receive window of 10 mss. */ |
65 | #define TCP_DEFAULT_INIT_RCVWND 10 | |
66 | ||
1da177e4 LT |
67 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ |
68 | #define TCP_MIN_MSS 88U | |
69 | ||
5d424d5a JH |
70 | /* The least MTU to use for probing */ |
71 | #define TCP_BASE_MSS 512 | |
72 | ||
1da177e4 LT |
73 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
74 | #define TCP_FASTRETRANS_THRESH 3 | |
75 | ||
76 | /* Maximal reordering. */ | |
77 | #define TCP_MAX_REORDERING 127 | |
78 | ||
79 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ | |
80 | #define TCP_MAX_QUICKACKS 16U | |
81 | ||
82 | /* urg_data states */ | |
83 | #define TCP_URG_VALID 0x0100 | |
84 | #define TCP_URG_NOTYET 0x0200 | |
85 | #define TCP_URG_READ 0x0400 | |
86 | ||
87 | #define TCP_RETR1 3 /* | |
88 | * This is how many retries it does before it | |
89 | * tries to figure out if the gateway is | |
90 | * down. Minimal RFC value is 3; it corresponds | |
91 | * to ~3sec-8min depending on RTO. | |
92 | */ | |
93 | ||
94 | #define TCP_RETR2 15 /* | |
95 | * This should take at least | |
96 | * 90 minutes to time out. | |
97 | * RFC1122 says that the limit is 100 sec. | |
98 | * 15 is ~13-30min depending on RTO. | |
99 | */ | |
100 | ||
101 | #define TCP_SYN_RETRIES 5 /* number of times to retry active opening a | |
caa20d9a | 102 | * connection: ~180sec is RFC minimum */ |
1da177e4 LT |
103 | |
104 | #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a | |
caa20d9a | 105 | * connection: ~180sec is RFC minimum */ |
1da177e4 | 106 | |
1da177e4 LT |
107 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
108 | * state, about 60 seconds */ | |
109 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN | |
110 | /* BSD style FIN_WAIT2 deadlock breaker. | |
111 | * It used to be 3min, new value is 60sec, | |
112 | * to combine FIN-WAIT-2 timeout with | |
113 | * TIME-WAIT timer. | |
114 | */ | |
115 | ||
116 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ | |
117 | #if HZ >= 100 | |
118 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ | |
119 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) | |
120 | #else | |
121 | #define TCP_DELACK_MIN 4U | |
122 | #define TCP_ATO_MIN 4U | |
123 | #endif | |
124 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) | |
125 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) | |
fd4f2cea | 126 | #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ |
9ad7c049 JC |
127 | #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now |
128 | * used as a fallback RTO for the | |
129 | * initial data transmission if no | |
130 | * valid RTT sample has been acquired, | |
131 | * most likely due to retrans in 3WHS. | |
132 | */ | |
1da177e4 LT |
133 | |
134 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes | |
135 | * for local resources. | |
136 | */ | |
137 | ||
138 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ | |
139 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ | |
140 | #define TCP_KEEPALIVE_INTVL (75*HZ) | |
141 | ||
142 | #define MAX_TCP_KEEPIDLE 32767 | |
143 | #define MAX_TCP_KEEPINTVL 32767 | |
144 | #define MAX_TCP_KEEPCNT 127 | |
145 | #define MAX_TCP_SYNCNT 127 | |
146 | ||
147 | #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ | |
1da177e4 LT |
148 | |
149 | #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) | |
150 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated | |
151 | * after this time. It should be equal | |
152 | * (or greater than) TCP_TIMEWAIT_LEN | |
153 | * to provide reliability equal to one | |
154 | * provided by timewait state. | |
155 | */ | |
156 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host | |
157 | * timestamps. It must be less than | |
158 | * minimal timewait lifetime. | |
159 | */ | |
1da177e4 LT |
160 | /* |
161 | * TCP option | |
162 | */ | |
163 | ||
164 | #define TCPOPT_NOP 1 /* Padding */ | |
165 | #define TCPOPT_EOL 0 /* End of options */ | |
166 | #define TCPOPT_MSS 2 /* Segment size negotiating */ | |
167 | #define TCPOPT_WINDOW 3 /* Window scaling */ | |
168 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ | |
169 | #define TCPOPT_SACK 5 /* SACK Block */ | |
170 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ | |
cfb6eeb4 | 171 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
435cf559 | 172 | #define TCPOPT_COOKIE 253 /* Cookie extension (experimental) */ |
1da177e4 LT |
173 | |
174 | /* | |
175 | * TCP option lengths | |
176 | */ | |
177 | ||
178 | #define TCPOLEN_MSS 4 | |
179 | #define TCPOLEN_WINDOW 3 | |
180 | #define TCPOLEN_SACK_PERM 2 | |
181 | #define TCPOLEN_TIMESTAMP 10 | |
cfb6eeb4 | 182 | #define TCPOLEN_MD5SIG 18 |
435cf559 WAS |
183 | #define TCPOLEN_COOKIE_BASE 2 /* Cookie-less header extension */ |
184 | #define TCPOLEN_COOKIE_PAIR 3 /* Cookie pair header extension */ | |
185 | #define TCPOLEN_COOKIE_MIN (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MIN) | |
186 | #define TCPOLEN_COOKIE_MAX (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MAX) | |
1da177e4 LT |
187 | |
188 | /* But this is what stacks really send out. */ | |
189 | #define TCPOLEN_TSTAMP_ALIGNED 12 | |
190 | #define TCPOLEN_WSCALE_ALIGNED 4 | |
191 | #define TCPOLEN_SACKPERM_ALIGNED 4 | |
192 | #define TCPOLEN_SACK_BASE 2 | |
193 | #define TCPOLEN_SACK_BASE_ALIGNED 4 | |
194 | #define TCPOLEN_SACK_PERBLOCK 8 | |
cfb6eeb4 | 195 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
33ad798c | 196 | #define TCPOLEN_MSS_ALIGNED 4 |
1da177e4 | 197 | |
1da177e4 LT |
198 | /* Flags in tp->nonagle */ |
199 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ | |
200 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ | |
caa20d9a | 201 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
1da177e4 | 202 | |
36e31b0a AP |
203 | /* TCP thin-stream limits */ |
204 | #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ | |
205 | ||
7eb38527 | 206 | /* TCP initial congestion window as per draft-hkchu-tcpm-initcwnd-01 */ |
442b9635 DM |
207 | #define TCP_INIT_CWND 10 |
208 | ||
295ff7ed ACM |
209 | extern struct inet_timewait_death_row tcp_death_row; |
210 | ||
1da177e4 | 211 | /* sysctl variables for tcp */ |
1da177e4 LT |
212 | extern int sysctl_tcp_timestamps; |
213 | extern int sysctl_tcp_window_scaling; | |
214 | extern int sysctl_tcp_sack; | |
215 | extern int sysctl_tcp_fin_timeout; | |
1da177e4 LT |
216 | extern int sysctl_tcp_keepalive_time; |
217 | extern int sysctl_tcp_keepalive_probes; | |
218 | extern int sysctl_tcp_keepalive_intvl; | |
219 | extern int sysctl_tcp_syn_retries; | |
220 | extern int sysctl_tcp_synack_retries; | |
221 | extern int sysctl_tcp_retries1; | |
222 | extern int sysctl_tcp_retries2; | |
223 | extern int sysctl_tcp_orphan_retries; | |
224 | extern int sysctl_tcp_syncookies; | |
225 | extern int sysctl_tcp_retrans_collapse; | |
226 | extern int sysctl_tcp_stdurg; | |
227 | extern int sysctl_tcp_rfc1337; | |
228 | extern int sysctl_tcp_abort_on_overflow; | |
229 | extern int sysctl_tcp_max_orphans; | |
1da177e4 LT |
230 | extern int sysctl_tcp_fack; |
231 | extern int sysctl_tcp_reordering; | |
232 | extern int sysctl_tcp_ecn; | |
233 | extern int sysctl_tcp_dsack; | |
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 | ||
efcdbf24 AS |
277 | static inline bool tcp_out_of_memory(struct sock *sk) |
278 | { | |
279 | if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && | |
280 | sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2)) | |
281 | return true; | |
282 | return false; | |
283 | } | |
284 | ||
ad1af0fe | 285 | static inline bool tcp_too_many_orphans(struct sock *sk, int shift) |
e4fd5da3 | 286 | { |
ad1af0fe DM |
287 | struct percpu_counter *ocp = sk->sk_prot->orphan_count; |
288 | int orphans = percpu_counter_read_positive(ocp); | |
289 | ||
290 | if (orphans << shift > sysctl_tcp_max_orphans) { | |
291 | orphans = percpu_counter_sum_positive(ocp); | |
292 | if (orphans << shift > sysctl_tcp_max_orphans) | |
293 | return true; | |
294 | } | |
ad1af0fe | 295 | return false; |
e4fd5da3 | 296 | } |
1da177e4 | 297 | |
efcdbf24 AS |
298 | extern bool tcp_check_oom(struct sock *sk, int shift); |
299 | ||
a0f82f64 FW |
300 | /* syncookies: remember time of last synqueue overflow */ |
301 | static inline void tcp_synq_overflow(struct sock *sk) | |
302 | { | |
303 | tcp_sk(sk)->rx_opt.ts_recent_stamp = jiffies; | |
304 | } | |
305 | ||
306 | /* syncookies: no recent synqueue overflow on this listening socket? */ | |
307 | static inline int tcp_synq_no_recent_overflow(const struct sock *sk) | |
308 | { | |
309 | unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; | |
9ad7c049 | 310 | return time_after(jiffies, last_overflow + TCP_TIMEOUT_FALLBACK); |
a0f82f64 FW |
311 | } |
312 | ||
1da177e4 LT |
313 | extern struct proto tcp_prot; |
314 | ||
57ef42d5 PE |
315 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
316 | #define TCP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.tcp_statistics, field) | |
317 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) | |
318 | #define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val) | |
aa2ea058 | 319 | #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) |
1da177e4 | 320 | |
4acb4190 GC |
321 | extern void tcp_init_mem(struct net *net); |
322 | ||
53d3176b CG |
323 | extern void tcp_v4_err(struct sk_buff *skb, u32); |
324 | ||
325 | extern void tcp_shutdown (struct sock *sk, int how); | |
326 | ||
327 | extern int tcp_v4_rcv(struct sk_buff *skb); | |
328 | ||
3f419d2d | 329 | extern struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it); |
ccb7c410 | 330 | extern void *tcp_v4_tw_get_peer(struct sock *sk); |
53d3176b | 331 | extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); |
7ba42910 CG |
332 | extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, |
333 | size_t size); | |
334 | extern int tcp_sendpage(struct sock *sk, struct page *page, int offset, | |
335 | size_t size, int flags); | |
53d3176b CG |
336 | extern int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg); |
337 | extern int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, | |
cf533ea5 | 338 | const struct tcphdr *th, unsigned int len); |
53d3176b | 339 | extern int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, |
cf533ea5 | 340 | const struct tcphdr *th, unsigned int len); |
53d3176b CG |
341 | extern void tcp_rcv_space_adjust(struct sock *sk); |
342 | extern void tcp_cleanup_rbuf(struct sock *sk, int copied); | |
343 | extern int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); | |
344 | extern void tcp_twsk_destructor(struct sock *sk); | |
345 | extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, | |
346 | struct pipe_inode_info *pipe, size_t len, | |
347 | unsigned int flags); | |
9c55e01c | 348 | |
463c84b9 ACM |
349 | static inline void tcp_dec_quickack_mode(struct sock *sk, |
350 | const unsigned int pkts) | |
1da177e4 | 351 | { |
463c84b9 | 352 | struct inet_connection_sock *icsk = inet_csk(sk); |
fc6415bc | 353 | |
463c84b9 ACM |
354 | if (icsk->icsk_ack.quick) { |
355 | if (pkts >= icsk->icsk_ack.quick) { | |
356 | icsk->icsk_ack.quick = 0; | |
fc6415bc | 357 | /* Leaving quickack mode we deflate ATO. */ |
463c84b9 | 358 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
fc6415bc | 359 | } else |
463c84b9 | 360 | icsk->icsk_ack.quick -= pkts; |
1da177e4 LT |
361 | } |
362 | } | |
363 | ||
bdf1ee5d IJ |
364 | #define TCP_ECN_OK 1 |
365 | #define TCP_ECN_QUEUE_CWR 2 | |
366 | #define TCP_ECN_DEMAND_CWR 4 | |
7a269ffa | 367 | #define TCP_ECN_SEEN 8 |
bdf1ee5d IJ |
368 | |
369 | static __inline__ void | |
370 | TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th) | |
371 | { | |
372 | if (sysctl_tcp_ecn && th->ece && th->cwr) | |
373 | inet_rsk(req)->ecn_ok = 1; | |
374 | } | |
375 | ||
fd2c3ef7 | 376 | enum tcp_tw_status { |
1da177e4 LT |
377 | TCP_TW_SUCCESS = 0, |
378 | TCP_TW_RST = 1, | |
379 | TCP_TW_ACK = 2, | |
380 | TCP_TW_SYN = 3 | |
381 | }; | |
382 | ||
383 | ||
53d3176b CG |
384 | extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
385 | struct sk_buff *skb, | |
386 | const struct tcphdr *th); | |
387 | extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb, | |
388 | struct request_sock *req, | |
389 | struct request_sock **prev); | |
390 | extern int tcp_child_process(struct sock *parent, struct sock *child, | |
391 | struct sk_buff *skb); | |
392 | extern int tcp_use_frto(struct sock *sk); | |
393 | extern void tcp_enter_frto(struct sock *sk); | |
394 | extern void tcp_enter_loss(struct sock *sk, int how); | |
395 | extern void tcp_clear_retrans(struct tcp_sock *tp); | |
396 | extern void tcp_update_metrics(struct sock *sk); | |
397 | extern void tcp_close(struct sock *sk, long timeout); | |
398 | extern unsigned int tcp_poll(struct file * file, struct socket *sock, | |
399 | struct poll_table_struct *wait); | |
400 | extern int tcp_getsockopt(struct sock *sk, int level, int optname, | |
401 | char __user *optval, int __user *optlen); | |
402 | extern int tcp_setsockopt(struct sock *sk, int level, int optname, | |
403 | char __user *optval, unsigned int optlen); | |
404 | extern int compat_tcp_getsockopt(struct sock *sk, int level, int optname, | |
405 | char __user *optval, int __user *optlen); | |
406 | extern int compat_tcp_setsockopt(struct sock *sk, int level, int optname, | |
407 | char __user *optval, unsigned int optlen); | |
408 | extern void tcp_set_keepalive(struct sock *sk, int val); | |
409 | extern void tcp_syn_ack_timeout(struct sock *sk, struct request_sock *req); | |
410 | extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, | |
411 | size_t len, int nonblock, int flags, int *addr_len); | |
cf533ea5 ED |
412 | extern void tcp_parse_options(const struct sk_buff *skb, |
413 | struct tcp_options_received *opt_rx, const u8 **hvpp, | |
53d3176b | 414 | int estab); |
cf533ea5 | 415 | extern const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); |
7d5d5525 | 416 | |
1da177e4 LT |
417 | /* |
418 | * TCP v4 functions exported for the inet6 API | |
419 | */ | |
420 | ||
53d3176b CG |
421 | extern void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
422 | extern int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); | |
423 | extern struct sock * tcp_create_openreq_child(struct sock *sk, | |
424 | struct request_sock *req, | |
1da177e4 | 425 | struct sk_buff *skb); |
53d3176b CG |
426 | extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, |
427 | struct request_sock *req, | |
428 | struct dst_entry *dst); | |
429 | extern int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); | |
430 | extern int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, | |
431 | int addr_len); | |
432 | extern int tcp_connect(struct sock *sk); | |
433 | extern struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst, | |
434 | struct request_sock *req, | |
435 | struct request_values *rvp); | |
436 | extern int tcp_disconnect(struct sock *sk, int flags); | |
1da177e4 | 437 | |
1da177e4 | 438 | |
1da177e4 | 439 | /* From syncookies.c */ |
2051f11f | 440 | extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS]; |
1da177e4 LT |
441 | extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, |
442 | struct ip_options *opt); | |
e05c82d3 | 443 | #ifdef CONFIG_SYN_COOKIES |
1da177e4 LT |
444 | extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, |
445 | __u16 *mss); | |
e05c82d3 ED |
446 | #else |
447 | static inline __u32 cookie_v4_init_sequence(struct sock *sk, | |
448 | struct sk_buff *skb, | |
449 | __u16 *mss) | |
450 | { | |
451 | return 0; | |
452 | } | |
453 | #endif | |
1da177e4 | 454 | |
4dfc2817 | 455 | extern __u32 cookie_init_timestamp(struct request_sock *req); |
172d69e6 | 456 | extern bool cookie_check_timestamp(struct tcp_options_received *opt, bool *); |
4dfc2817 | 457 | |
c6aefafb GG |
458 | /* From net/ipv6/syncookies.c */ |
459 | extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); | |
e05c82d3 | 460 | #ifdef CONFIG_SYN_COOKIES |
cf533ea5 | 461 | extern __u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, |
c6aefafb | 462 | __u16 *mss); |
e05c82d3 ED |
463 | #else |
464 | static inline __u32 cookie_v6_init_sequence(struct sock *sk, | |
465 | struct sk_buff *skb, | |
466 | __u16 *mss) | |
467 | { | |
468 | return 0; | |
469 | } | |
470 | #endif | |
1da177e4 LT |
471 | /* tcp_output.c */ |
472 | ||
9e412ba7 IJ |
473 | extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
474 | int nonagle); | |
475 | extern int tcp_may_send_now(struct sock *sk); | |
1da177e4 | 476 | extern int tcp_retransmit_skb(struct sock *, struct sk_buff *); |
f1ecd5d9 | 477 | extern void tcp_retransmit_timer(struct sock *sk); |
1da177e4 LT |
478 | extern void tcp_xmit_retransmit_queue(struct sock *); |
479 | extern void tcp_simple_retransmit(struct sock *); | |
480 | extern int tcp_trim_head(struct sock *, struct sk_buff *, u32); | |
6475be16 | 481 | extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int); |
1da177e4 LT |
482 | |
483 | extern void tcp_send_probe0(struct sock *); | |
484 | extern void tcp_send_partial(struct sock *); | |
53d3176b | 485 | extern int tcp_write_wakeup(struct sock *); |
1da177e4 | 486 | extern void tcp_send_fin(struct sock *sk); |
dd0fc66f | 487 | extern void tcp_send_active_reset(struct sock *sk, gfp_t priority); |
53d3176b | 488 | extern int tcp_send_synack(struct sock *); |
946cedcc ED |
489 | extern int tcp_syn_flood_action(struct sock *sk, |
490 | const struct sk_buff *skb, | |
491 | const char *proto); | |
c1b4a7e6 | 492 | extern void tcp_push_one(struct sock *, unsigned int mss_now); |
1da177e4 LT |
493 | extern void tcp_send_ack(struct sock *sk); |
494 | extern void tcp_send_delayed_ack(struct sock *sk); | |
495 | ||
a762a980 DM |
496 | /* tcp_input.c */ |
497 | extern void tcp_cwnd_application_limited(struct sock *sk); | |
498 | ||
1da177e4 LT |
499 | /* tcp_timer.c */ |
500 | extern void tcp_init_xmit_timers(struct sock *); | |
463c84b9 ACM |
501 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
502 | { | |
503 | inet_csk_clear_xmit_timers(sk); | |
504 | } | |
1da177e4 | 505 | |
1da177e4 | 506 | extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
0c54b85f IJ |
507 | extern unsigned int tcp_current_mss(struct sock *sk); |
508 | ||
509 | /* Bound MSS / TSO packet size with the half of the window */ | |
510 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) | |
511 | { | |
01f83d69 AK |
512 | int cutoff; |
513 | ||
514 | /* When peer uses tiny windows, there is no use in packetizing | |
515 | * to sub-MSS pieces for the sake of SWS or making sure there | |
516 | * are enough packets in the pipe for fast recovery. | |
517 | * | |
518 | * On the other hand, for extremely large MSS devices, handling | |
519 | * smaller than MSS windows in this way does make sense. | |
520 | */ | |
521 | if (tp->max_window >= 512) | |
522 | cutoff = (tp->max_window >> 1); | |
523 | else | |
524 | cutoff = tp->max_window; | |
525 | ||
526 | if (cutoff && pktsize > cutoff) | |
527 | return max_t(int, cutoff, 68U - tp->tcp_header_len); | |
0c54b85f IJ |
528 | else |
529 | return pktsize; | |
530 | } | |
1da177e4 | 531 | |
17b085ea | 532 | /* tcp.c */ |
cf533ea5 | 533 | extern void tcp_get_info(const struct sock *, struct tcp_info *); |
1da177e4 LT |
534 | |
535 | /* Read 'sendfile()'-style from a TCP socket */ | |
536 | typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *, | |
537 | unsigned int, size_t); | |
538 | extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, | |
539 | sk_read_actor_t recv_actor); | |
540 | ||
40efc6fa | 541 | extern void tcp_initialize_rcv_mss(struct sock *sk); |
1da177e4 | 542 | |
cf533ea5 ED |
543 | extern int tcp_mtu_to_mss(const struct sock *sk, int pmtu); |
544 | extern int tcp_mss_to_mtu(const struct sock *sk, int mss); | |
5d424d5a | 545 | extern void tcp_mtup_init(struct sock *sk); |
9ad7c049 | 546 | extern void tcp_valid_rtt_meas(struct sock *sk, u32 seq_rtt); |
5d424d5a | 547 | |
f1ecd5d9 DL |
548 | static inline void tcp_bound_rto(const struct sock *sk) |
549 | { | |
550 | if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) | |
551 | inet_csk(sk)->icsk_rto = TCP_RTO_MAX; | |
552 | } | |
553 | ||
554 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) | |
555 | { | |
556 | return (tp->srtt >> 3) + tp->rttvar; | |
557 | } | |
558 | ||
40efc6fa | 559 | static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
1da177e4 LT |
560 | { |
561 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | | |
562 | ntohl(TCP_FLAG_ACK) | | |
563 | snd_wnd); | |
564 | } | |
565 | ||
40efc6fa | 566 | static inline void tcp_fast_path_on(struct tcp_sock *tp) |
1da177e4 LT |
567 | { |
568 | __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); | |
569 | } | |
570 | ||
9e412ba7 | 571 | static inline void tcp_fast_path_check(struct sock *sk) |
1da177e4 | 572 | { |
9e412ba7 IJ |
573 | struct tcp_sock *tp = tcp_sk(sk); |
574 | ||
b03efcfb | 575 | if (skb_queue_empty(&tp->out_of_order_queue) && |
1da177e4 LT |
576 | tp->rcv_wnd && |
577 | atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && | |
578 | !tp->urg_data) | |
579 | tcp_fast_path_on(tp); | |
580 | } | |
581 | ||
0c266898 SS |
582 | /* Compute the actual rto_min value */ |
583 | static inline u32 tcp_rto_min(struct sock *sk) | |
584 | { | |
cf533ea5 | 585 | const struct dst_entry *dst = __sk_dst_get(sk); |
0c266898 SS |
586 | u32 rto_min = TCP_RTO_MIN; |
587 | ||
588 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) | |
589 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); | |
590 | return rto_min; | |
591 | } | |
592 | ||
1da177e4 LT |
593 | /* Compute the actual receive window we are currently advertising. |
594 | * Rcv_nxt can be after the window if our peer push more data | |
595 | * than the offered window. | |
596 | */ | |
40efc6fa | 597 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
1da177e4 LT |
598 | { |
599 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; | |
600 | ||
601 | if (win < 0) | |
602 | win = 0; | |
603 | return (u32) win; | |
604 | } | |
605 | ||
606 | /* Choose a new window, without checks for shrinking, and without | |
607 | * scaling applied to the result. The caller does these things | |
608 | * if necessary. This is a "raw" window selection. | |
609 | */ | |
53d3176b | 610 | extern u32 __tcp_select_window(struct sock *sk); |
1da177e4 LT |
611 | |
612 | /* TCP timestamps are only 32-bits, this causes a slight | |
613 | * complication on 64-bit systems since we store a snapshot | |
31f34269 SH |
614 | * of jiffies in the buffer control blocks below. We decided |
615 | * to use only the low 32-bits of jiffies and hide the ugly | |
1da177e4 LT |
616 | * casts with the following macro. |
617 | */ | |
618 | #define tcp_time_stamp ((__u32)(jiffies)) | |
619 | ||
a3433f35 CG |
620 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
621 | ||
622 | #define TCPHDR_FIN 0x01 | |
623 | #define TCPHDR_SYN 0x02 | |
624 | #define TCPHDR_RST 0x04 | |
625 | #define TCPHDR_PSH 0x08 | |
626 | #define TCPHDR_ACK 0x10 | |
627 | #define TCPHDR_URG 0x20 | |
628 | #define TCPHDR_ECE 0x40 | |
629 | #define TCPHDR_CWR 0x80 | |
630 | ||
caa20d9a | 631 | /* This is what the send packet queuing engine uses to pass |
f86586fa ED |
632 | * TCP per-packet control information to the transmission code. |
633 | * We also store the host-order sequence numbers in here too. | |
634 | * This is 44 bytes if IPV6 is enabled. | |
635 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. | |
1da177e4 LT |
636 | */ |
637 | struct tcp_skb_cb { | |
638 | union { | |
639 | struct inet_skb_parm h4; | |
dfd56b8b | 640 | #if IS_ENABLED(CONFIG_IPV6) |
1da177e4 LT |
641 | struct inet6_skb_parm h6; |
642 | #endif | |
643 | } header; /* For incoming frames */ | |
644 | __u32 seq; /* Starting sequence number */ | |
645 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ | |
646 | __u32 when; /* used to compute rtt's */ | |
4de075e0 | 647 | __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ |
1da177e4 LT |
648 | __u8 sacked; /* State flags for SACK/FACK. */ |
649 | #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ | |
650 | #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ | |
651 | #define TCPCB_LOST 0x04 /* SKB is lost */ | |
652 | #define TCPCB_TAGBITS 0x07 /* All tag bits */ | |
b82d1bb4 ED |
653 | __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ |
654 | /* 1 byte hole */ | |
1da177e4 LT |
655 | #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ |
656 | #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS) | |
657 | ||
1da177e4 LT |
658 | __u32 ack_seq; /* Sequence number ACK'd */ |
659 | }; | |
660 | ||
661 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) | |
662 | ||
1da177e4 LT |
663 | /* Due to TSO, an SKB can be composed of multiple actual |
664 | * packets. To keep these tracked properly, we use this. | |
665 | */ | |
666 | static inline int tcp_skb_pcount(const struct sk_buff *skb) | |
667 | { | |
7967168c | 668 | return skb_shinfo(skb)->gso_segs; |
1da177e4 LT |
669 | } |
670 | ||
671 | /* This is valid iff tcp_skb_pcount() > 1. */ | |
672 | static inline int tcp_skb_mss(const struct sk_buff *skb) | |
673 | { | |
7967168c | 674 | return skb_shinfo(skb)->gso_size; |
1da177e4 LT |
675 | } |
676 | ||
317a76f9 SH |
677 | /* Events passed to congestion control interface */ |
678 | enum tcp_ca_event { | |
679 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ | |
680 | CA_EVENT_CWND_RESTART, /* congestion window restart */ | |
681 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ | |
682 | CA_EVENT_FRTO, /* fast recovery timeout */ | |
683 | CA_EVENT_LOSS, /* loss timeout */ | |
684 | CA_EVENT_FAST_ACK, /* in sequence ack */ | |
685 | CA_EVENT_SLOW_ACK, /* other ack */ | |
686 | }; | |
687 | ||
688 | /* | |
689 | * Interface for adding new TCP congestion control handlers | |
690 | */ | |
691 | #define TCP_CA_NAME_MAX 16 | |
3ff825b2 SH |
692 | #define TCP_CA_MAX 128 |
693 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) | |
694 | ||
164891aa SH |
695 | #define TCP_CONG_NON_RESTRICTED 0x1 |
696 | #define TCP_CONG_RTT_STAMP 0x2 | |
697 | ||
317a76f9 SH |
698 | struct tcp_congestion_ops { |
699 | struct list_head list; | |
164891aa | 700 | unsigned long flags; |
317a76f9 SH |
701 | |
702 | /* initialize private data (optional) */ | |
6687e988 | 703 | void (*init)(struct sock *sk); |
317a76f9 | 704 | /* cleanup private data (optional) */ |
6687e988 | 705 | void (*release)(struct sock *sk); |
317a76f9 SH |
706 | |
707 | /* return slow start threshold (required) */ | |
6687e988 | 708 | u32 (*ssthresh)(struct sock *sk); |
317a76f9 | 709 | /* lower bound for congestion window (optional) */ |
72dc5b92 | 710 | u32 (*min_cwnd)(const struct sock *sk); |
317a76f9 | 711 | /* do new cwnd calculation (required) */ |
c3a05c60 | 712 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight); |
317a76f9 | 713 | /* call before changing ca_state (optional) */ |
6687e988 | 714 | void (*set_state)(struct sock *sk, u8 new_state); |
317a76f9 | 715 | /* call when cwnd event occurs (optional) */ |
6687e988 | 716 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
317a76f9 | 717 | /* new value of cwnd after loss (optional) */ |
6687e988 | 718 | u32 (*undo_cwnd)(struct sock *sk); |
317a76f9 | 719 | /* hook for packet ack accounting (optional) */ |
30cfd0ba | 720 | void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us); |
73c1f4a0 | 721 | /* get info for inet_diag (optional) */ |
6687e988 | 722 | void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb); |
317a76f9 SH |
723 | |
724 | char name[TCP_CA_NAME_MAX]; | |
725 | struct module *owner; | |
726 | }; | |
727 | ||
728 | extern int tcp_register_congestion_control(struct tcp_congestion_ops *type); | |
729 | extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); | |
730 | ||
6687e988 ACM |
731 | extern void tcp_init_congestion_control(struct sock *sk); |
732 | extern void tcp_cleanup_congestion_control(struct sock *sk); | |
317a76f9 SH |
733 | extern int tcp_set_default_congestion_control(const char *name); |
734 | extern void tcp_get_default_congestion_control(char *name); | |
3ff825b2 | 735 | extern void tcp_get_available_congestion_control(char *buf, size_t len); |
ce7bc3bf SH |
736 | extern void tcp_get_allowed_congestion_control(char *buf, size_t len); |
737 | extern int tcp_set_allowed_congestion_control(char *allowed); | |
6687e988 | 738 | extern int tcp_set_congestion_control(struct sock *sk, const char *name); |
40efc6fa | 739 | extern void tcp_slow_start(struct tcp_sock *tp); |
758ce5c8 | 740 | extern void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w); |
317a76f9 | 741 | |
5f8ef48d | 742 | extern struct tcp_congestion_ops tcp_init_congestion_ops; |
6687e988 | 743 | extern u32 tcp_reno_ssthresh(struct sock *sk); |
c3a05c60 | 744 | extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight); |
72dc5b92 | 745 | extern u32 tcp_reno_min_cwnd(const struct sock *sk); |
a8acfbac | 746 | extern struct tcp_congestion_ops tcp_reno; |
317a76f9 | 747 | |
6687e988 | 748 | static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state) |
317a76f9 | 749 | { |
6687e988 ACM |
750 | struct inet_connection_sock *icsk = inet_csk(sk); |
751 | ||
752 | if (icsk->icsk_ca_ops->set_state) | |
753 | icsk->icsk_ca_ops->set_state(sk, ca_state); | |
754 | icsk->icsk_ca_state = ca_state; | |
317a76f9 SH |
755 | } |
756 | ||
6687e988 | 757 | static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) |
317a76f9 | 758 | { |
6687e988 ACM |
759 | const struct inet_connection_sock *icsk = inet_csk(sk); |
760 | ||
761 | if (icsk->icsk_ca_ops->cwnd_event) | |
762 | icsk->icsk_ca_ops->cwnd_event(sk, event); | |
317a76f9 SH |
763 | } |
764 | ||
e60402d0 IJ |
765 | /* These functions determine how the current flow behaves in respect of SACK |
766 | * handling. SACK is negotiated with the peer, and therefore it can vary | |
767 | * between different flows. | |
768 | * | |
769 | * tcp_is_sack - SACK enabled | |
770 | * tcp_is_reno - No SACK | |
771 | * tcp_is_fack - FACK enabled, implies SACK enabled | |
772 | */ | |
773 | static inline int tcp_is_sack(const struct tcp_sock *tp) | |
774 | { | |
775 | return tp->rx_opt.sack_ok; | |
776 | } | |
777 | ||
778 | static inline int tcp_is_reno(const struct tcp_sock *tp) | |
779 | { | |
780 | return !tcp_is_sack(tp); | |
781 | } | |
782 | ||
783 | static inline int tcp_is_fack(const struct tcp_sock *tp) | |
784 | { | |
ab56222a | 785 | return tp->rx_opt.sack_ok & TCP_FACK_ENABLED; |
e60402d0 IJ |
786 | } |
787 | ||
788 | static inline void tcp_enable_fack(struct tcp_sock *tp) | |
789 | { | |
ab56222a | 790 | tp->rx_opt.sack_ok |= TCP_FACK_ENABLED; |
e60402d0 IJ |
791 | } |
792 | ||
83ae4088 IJ |
793 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
794 | { | |
795 | return tp->sacked_out + tp->lost_out; | |
796 | } | |
797 | ||
1da177e4 LT |
798 | /* This determines how many packets are "in the network" to the best |
799 | * of our knowledge. In many cases it is conservative, but where | |
800 | * detailed information is available from the receiver (via SACK | |
801 | * blocks etc.) we can make more aggressive calculations. | |
802 | * | |
803 | * Use this for decisions involving congestion control, use just | |
804 | * tp->packets_out to determine if the send queue is empty or not. | |
805 | * | |
806 | * Read this equation as: | |
807 | * | |
808 | * "Packets sent once on transmission queue" MINUS | |
809 | * "Packets left network, but not honestly ACKed yet" PLUS | |
810 | * "Packets fast retransmitted" | |
811 | */ | |
40efc6fa | 812 | static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
1da177e4 | 813 | { |
83ae4088 | 814 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
1da177e4 LT |
815 | } |
816 | ||
0b6a05c1 IJ |
817 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
818 | ||
819 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) | |
820 | { | |
821 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; | |
822 | } | |
823 | ||
1da177e4 LT |
824 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
825 | * The exception is rate halving phase, when cwnd is decreasing towards | |
826 | * ssthresh. | |
827 | */ | |
6687e988 | 828 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
1da177e4 | 829 | { |
6687e988 | 830 | const struct tcp_sock *tp = tcp_sk(sk); |
cf533ea5 | 831 | |
6687e988 | 832 | if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery)) |
1da177e4 LT |
833 | return tp->snd_ssthresh; |
834 | else | |
835 | return max(tp->snd_ssthresh, | |
836 | ((tp->snd_cwnd >> 1) + | |
837 | (tp->snd_cwnd >> 2))); | |
838 | } | |
839 | ||
b9c4595b IJ |
840 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
841 | #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) | |
1da177e4 | 842 | |
3cfe3baa | 843 | extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh); |
cf533ea5 | 844 | extern __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); |
1da177e4 | 845 | |
6b5a5c0d NC |
846 | /* The maximum number of MSS of available cwnd for which TSO defers |
847 | * sending if not using sysctl_tcp_tso_win_divisor. | |
848 | */ | |
849 | static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) | |
850 | { | |
851 | return 3; | |
852 | } | |
853 | ||
1da177e4 | 854 | /* Slow start with delack produces 3 packets of burst, so that |
dd9e0dda JH |
855 | * it is safe "de facto". This will be the default - same as |
856 | * the default reordering threshold - but if reordering increases, | |
857 | * we must be able to allow cwnd to burst at least this much in order | |
858 | * to not pull it back when holes are filled. | |
1da177e4 LT |
859 | */ |
860 | static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp) | |
861 | { | |
dd9e0dda | 862 | return tp->reordering; |
1da177e4 LT |
863 | } |
864 | ||
90840def IJ |
865 | /* Returns end sequence number of the receiver's advertised window */ |
866 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) | |
867 | { | |
868 | return tp->snd_una + tp->snd_wnd; | |
869 | } | |
cea14e0e | 870 | extern int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight); |
f4805ede | 871 | |
c1bd24b7 | 872 | static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss, |
40efc6fa | 873 | const struct sk_buff *skb) |
1da177e4 LT |
874 | { |
875 | if (skb->len < mss) | |
876 | tp->snd_sml = TCP_SKB_CB(skb)->end_seq; | |
877 | } | |
878 | ||
9e412ba7 | 879 | static inline void tcp_check_probe_timer(struct sock *sk) |
1da177e4 | 880 | { |
cf533ea5 | 881 | const struct tcp_sock *tp = tcp_sk(sk); |
463c84b9 | 882 | const struct inet_connection_sock *icsk = inet_csk(sk); |
9e412ba7 | 883 | |
463c84b9 | 884 | if (!tp->packets_out && !icsk->icsk_pending) |
3f421baa ACM |
885 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
886 | icsk->icsk_rto, TCP_RTO_MAX); | |
1da177e4 LT |
887 | } |
888 | ||
ee7537b6 | 889 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
890 | { |
891 | tp->snd_wl1 = seq; | |
892 | } | |
893 | ||
ee7537b6 | 894 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
895 | { |
896 | tp->snd_wl1 = seq; | |
897 | } | |
898 | ||
1da177e4 LT |
899 | /* |
900 | * Calculate(/check) TCP checksum | |
901 | */ | |
ba7808ea FD |
902 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
903 | __be32 daddr, __wsum base) | |
1da177e4 LT |
904 | { |
905 | return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); | |
906 | } | |
907 | ||
b51655b9 | 908 | static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb) |
1da177e4 | 909 | { |
fb286bb2 | 910 | return __skb_checksum_complete(skb); |
1da177e4 LT |
911 | } |
912 | ||
40efc6fa | 913 | static inline int tcp_checksum_complete(struct sk_buff *skb) |
1da177e4 | 914 | { |
60476372 | 915 | return !skb_csum_unnecessary(skb) && |
1da177e4 LT |
916 | __tcp_checksum_complete(skb); |
917 | } | |
918 | ||
919 | /* Prequeue for VJ style copy to user, combined with checksumming. */ | |
920 | ||
40efc6fa | 921 | static inline void tcp_prequeue_init(struct tcp_sock *tp) |
1da177e4 LT |
922 | { |
923 | tp->ucopy.task = NULL; | |
924 | tp->ucopy.len = 0; | |
925 | tp->ucopy.memory = 0; | |
926 | skb_queue_head_init(&tp->ucopy.prequeue); | |
97fc2f08 CL |
927 | #ifdef CONFIG_NET_DMA |
928 | tp->ucopy.dma_chan = NULL; | |
929 | tp->ucopy.wakeup = 0; | |
930 | tp->ucopy.pinned_list = NULL; | |
931 | tp->ucopy.dma_cookie = 0; | |
932 | #endif | |
1da177e4 LT |
933 | } |
934 | ||
935 | /* Packet is added to VJ-style prequeue for processing in process | |
936 | * context, if a reader task is waiting. Apparently, this exciting | |
937 | * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93) | |
938 | * failed somewhere. Latency? Burstiness? Well, at least now we will | |
939 | * see, why it failed. 8)8) --ANK | |
940 | * | |
941 | * NOTE: is this not too big to inline? | |
942 | */ | |
40efc6fa | 943 | static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
944 | { |
945 | struct tcp_sock *tp = tcp_sk(sk); | |
946 | ||
f5f8d86b ED |
947 | if (sysctl_tcp_low_latency || !tp->ucopy.task) |
948 | return 0; | |
949 | ||
950 | __skb_queue_tail(&tp->ucopy.prequeue, skb); | |
951 | tp->ucopy.memory += skb->truesize; | |
952 | if (tp->ucopy.memory > sk->sk_rcvbuf) { | |
953 | struct sk_buff *skb1; | |
954 | ||
955 | BUG_ON(sock_owned_by_user(sk)); | |
956 | ||
957 | while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) { | |
958 | sk_backlog_rcv(sk, skb1); | |
959 | NET_INC_STATS_BH(sock_net(sk), | |
960 | LINUX_MIB_TCPPREQUEUEDROPPED); | |
1da177e4 | 961 | } |
f5f8d86b ED |
962 | |
963 | tp->ucopy.memory = 0; | |
964 | } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { | |
aa395145 | 965 | wake_up_interruptible_sync_poll(sk_sleep(sk), |
7aedec2a | 966 | POLLIN | POLLRDNORM | POLLRDBAND); |
f5f8d86b ED |
967 | if (!inet_csk_ack_scheduled(sk)) |
968 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, | |
22f6dacd | 969 | (3 * tcp_rto_min(sk)) / 4, |
f5f8d86b | 970 | TCP_RTO_MAX); |
1da177e4 | 971 | } |
f5f8d86b | 972 | return 1; |
1da177e4 LT |
973 | } |
974 | ||
975 | ||
976 | #undef STATE_TRACE | |
977 | ||
978 | #ifdef STATE_TRACE | |
979 | static const char *statename[]={ | |
980 | "Unused","Established","Syn Sent","Syn Recv", | |
981 | "Fin Wait 1","Fin Wait 2","Time Wait", "Close", | |
982 | "Close Wait","Last ACK","Listen","Closing" | |
983 | }; | |
984 | #endif | |
490d5046 | 985 | extern void tcp_set_state(struct sock *sk, int state); |
1da177e4 | 986 | |
4ac02bab | 987 | extern void tcp_done(struct sock *sk); |
1da177e4 | 988 | |
40efc6fa | 989 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
1da177e4 LT |
990 | { |
991 | rx_opt->dsack = 0; | |
1da177e4 LT |
992 | rx_opt->num_sacks = 0; |
993 | } | |
994 | ||
1da177e4 LT |
995 | /* Determine a window scaling and initial window to offer. */ |
996 | extern void tcp_select_initial_window(int __space, __u32 mss, | |
997 | __u32 *rcv_wnd, __u32 *window_clamp, | |
31d12926 | 998 | int wscale_ok, __u8 *rcv_wscale, |
999 | __u32 init_rcv_wnd); | |
1da177e4 LT |
1000 | |
1001 | static inline int tcp_win_from_space(int space) | |
1002 | { | |
1003 | return sysctl_tcp_adv_win_scale<=0 ? | |
1004 | (space>>(-sysctl_tcp_adv_win_scale)) : | |
1005 | space - (space>>sysctl_tcp_adv_win_scale); | |
1006 | } | |
1007 | ||
1008 | /* Note: caller must be prepared to deal with negative returns */ | |
1009 | static inline int tcp_space(const struct sock *sk) | |
1010 | { | |
1011 | return tcp_win_from_space(sk->sk_rcvbuf - | |
1012 | atomic_read(&sk->sk_rmem_alloc)); | |
1013 | } | |
1014 | ||
1015 | static inline int tcp_full_space(const struct sock *sk) | |
1016 | { | |
1017 | return tcp_win_from_space(sk->sk_rcvbuf); | |
1018 | } | |
1019 | ||
40efc6fa SH |
1020 | static inline void tcp_openreq_init(struct request_sock *req, |
1021 | struct tcp_options_received *rx_opt, | |
1022 | struct sk_buff *skb) | |
1da177e4 | 1023 | { |
2e6599cb ACM |
1024 | struct inet_request_sock *ireq = inet_rsk(req); |
1025 | ||
1da177e4 | 1026 | req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */ |
4dfc2817 | 1027 | req->cookie_ts = 0; |
2e6599cb | 1028 | tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq; |
1da177e4 LT |
1029 | req->mss = rx_opt->mss_clamp; |
1030 | req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0; | |
2e6599cb ACM |
1031 | ireq->tstamp_ok = rx_opt->tstamp_ok; |
1032 | ireq->sack_ok = rx_opt->sack_ok; | |
1033 | ireq->snd_wscale = rx_opt->snd_wscale; | |
1034 | ireq->wscale_ok = rx_opt->wscale_ok; | |
1035 | ireq->acked = 0; | |
1036 | ireq->ecn_ok = 0; | |
aa8223c7 | 1037 | ireq->rmt_port = tcp_hdr(skb)->source; |
a3116ac5 | 1038 | ireq->loc_port = tcp_hdr(skb)->dest; |
1da177e4 LT |
1039 | } |
1040 | ||
5c52ba17 | 1041 | extern void tcp_enter_memory_pressure(struct sock *sk); |
1da177e4 | 1042 | |
1da177e4 LT |
1043 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
1044 | { | |
1045 | return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl; | |
1046 | } | |
1047 | ||
1048 | static inline int keepalive_time_when(const struct tcp_sock *tp) | |
1049 | { | |
1050 | return tp->keepalive_time ? : sysctl_tcp_keepalive_time; | |
1051 | } | |
1052 | ||
df19a626 ED |
1053 | static inline int keepalive_probes(const struct tcp_sock *tp) |
1054 | { | |
1055 | return tp->keepalive_probes ? : sysctl_tcp_keepalive_probes; | |
1056 | } | |
1057 | ||
6c37e5de FL |
1058 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
1059 | { | |
1060 | const struct inet_connection_sock *icsk = &tp->inet_conn; | |
1061 | ||
1062 | return min_t(u32, tcp_time_stamp - icsk->icsk_ack.lrcvtime, | |
1063 | tcp_time_stamp - tp->rcv_tstamp); | |
1064 | } | |
1065 | ||
463c84b9 | 1066 | static inline int tcp_fin_time(const struct sock *sk) |
1da177e4 | 1067 | { |
463c84b9 ACM |
1068 | int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout; |
1069 | const int rto = inet_csk(sk)->icsk_rto; | |
1da177e4 | 1070 | |
463c84b9 ACM |
1071 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
1072 | fin_timeout = (rto << 2) - (rto >> 1); | |
1da177e4 LT |
1073 | |
1074 | return fin_timeout; | |
1075 | } | |
1076 | ||
c887e6d2 IJ |
1077 | static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, |
1078 | int paws_win) | |
1da177e4 | 1079 | { |
c887e6d2 IJ |
1080 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
1081 | return 1; | |
1082 | if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)) | |
1083 | return 1; | |
bc2ce894 ED |
1084 | /* |
1085 | * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, | |
1086 | * then following tcp messages have valid values. Ignore 0 value, | |
1087 | * or else 'negative' tsval might forbid us to accept their packets. | |
1088 | */ | |
1089 | if (!rx_opt->ts_recent) | |
1090 | return 1; | |
c887e6d2 IJ |
1091 | return 0; |
1092 | } | |
1093 | ||
1094 | static inline int tcp_paws_reject(const struct tcp_options_received *rx_opt, | |
1095 | int rst) | |
1096 | { | |
1097 | if (tcp_paws_check(rx_opt, 0)) | |
1da177e4 LT |
1098 | return 0; |
1099 | ||
1100 | /* RST segments are not recommended to carry timestamp, | |
1101 | and, if they do, it is recommended to ignore PAWS because | |
1102 | "their cleanup function should take precedence over timestamps." | |
1103 | Certainly, it is mistake. It is necessary to understand the reasons | |
1104 | of this constraint to relax it: if peer reboots, clock may go | |
1105 | out-of-sync and half-open connections will not be reset. | |
1106 | Actually, the problem would be not existing if all | |
1107 | the implementations followed draft about maintaining clock | |
1108 | via reboots. Linux-2.2 DOES NOT! | |
1109 | ||
1110 | However, we can relax time bounds for RST segments to MSL. | |
1111 | */ | |
9d729f72 | 1112 | if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) |
1da177e4 LT |
1113 | return 0; |
1114 | return 1; | |
1115 | } | |
1116 | ||
a9c19329 | 1117 | static inline void tcp_mib_init(struct net *net) |
1da177e4 LT |
1118 | { |
1119 | /* See RFC 2012 */ | |
cf1100a7 PE |
1120 | TCP_ADD_STATS_USER(net, TCP_MIB_RTOALGORITHM, 1); |
1121 | TCP_ADD_STATS_USER(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); | |
1122 | TCP_ADD_STATS_USER(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); | |
1123 | TCP_ADD_STATS_USER(net, TCP_MIB_MAXCONN, -1); | |
1da177e4 LT |
1124 | } |
1125 | ||
5af4ec23 | 1126 | /* from STCP */ |
ef9da47c | 1127 | static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) |
0800f170 | 1128 | { |
6a438bbe SH |
1129 | tp->lost_skb_hint = NULL; |
1130 | tp->scoreboard_skb_hint = NULL; | |
ef9da47c IJ |
1131 | } |
1132 | ||
1133 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) | |
1134 | { | |
1135 | tcp_clear_retrans_hints_partial(tp); | |
6a438bbe | 1136 | tp->retransmit_skb_hint = NULL; |
b7689205 IJ |
1137 | } |
1138 | ||
cfb6eeb4 YH |
1139 | /* MD5 Signature */ |
1140 | struct crypto_hash; | |
1141 | ||
a915da9b ED |
1142 | union tcp_md5_addr { |
1143 | struct in_addr a4; | |
1144 | #if IS_ENABLED(CONFIG_IPV6) | |
1145 | struct in6_addr a6; | |
1146 | #endif | |
1147 | }; | |
1148 | ||
cfb6eeb4 YH |
1149 | /* - key database */ |
1150 | struct tcp_md5sig_key { | |
a915da9b | 1151 | struct hlist_node node; |
cfb6eeb4 | 1152 | u8 keylen; |
a915da9b ED |
1153 | u8 family; /* AF_INET or AF_INET6 */ |
1154 | union tcp_md5_addr addr; | |
1155 | u8 key[TCP_MD5SIG_MAXKEYLEN]; | |
1156 | struct rcu_head rcu; | |
cfb6eeb4 YH |
1157 | }; |
1158 | ||
1159 | /* - sock block */ | |
1160 | struct tcp_md5sig_info { | |
a915da9b | 1161 | struct hlist_head head; |
a8afca03 | 1162 | struct rcu_head rcu; |
cfb6eeb4 YH |
1163 | }; |
1164 | ||
1165 | /* - pseudo header */ | |
1166 | struct tcp4_pseudohdr { | |
1167 | __be32 saddr; | |
1168 | __be32 daddr; | |
1169 | __u8 pad; | |
1170 | __u8 protocol; | |
1171 | __be16 len; | |
1172 | }; | |
1173 | ||
1174 | struct tcp6_pseudohdr { | |
1175 | struct in6_addr saddr; | |
1176 | struct in6_addr daddr; | |
1177 | __be32 len; | |
1178 | __be32 protocol; /* including padding */ | |
1179 | }; | |
1180 | ||
1181 | union tcp_md5sum_block { | |
1182 | struct tcp4_pseudohdr ip4; | |
dfd56b8b | 1183 | #if IS_ENABLED(CONFIG_IPV6) |
cfb6eeb4 YH |
1184 | struct tcp6_pseudohdr ip6; |
1185 | #endif | |
1186 | }; | |
1187 | ||
1188 | /* - pool: digest algorithm, hash description and scratch buffer */ | |
1189 | struct tcp_md5sig_pool { | |
1190 | struct hash_desc md5_desc; | |
1191 | union tcp_md5sum_block md5_blk; | |
1192 | }; | |
1193 | ||
cfb6eeb4 | 1194 | /* - functions */ |
53d3176b | 1195 | extern int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key, |
318cf7aa ED |
1196 | const struct sock *sk, |
1197 | const struct request_sock *req, | |
1198 | const struct sk_buff *skb); | |
a915da9b ED |
1199 | extern int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
1200 | int family, const u8 *newkey, | |
1201 | u8 newkeylen, gfp_t gfp); | |
1202 | extern int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, | |
1203 | int family); | |
1204 | extern struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk, | |
1205 | struct sock *addr_sk); | |
cfb6eeb4 | 1206 | |
9501f972 | 1207 | #ifdef CONFIG_TCP_MD5SIG |
a915da9b ED |
1208 | extern struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, |
1209 | const union tcp_md5_addr *addr, int family); | |
1210 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) | |
9501f972 | 1211 | #else |
a915da9b ED |
1212 | static inline struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, |
1213 | const union tcp_md5_addr *addr, | |
1214 | int family) | |
1215 | { | |
1216 | return NULL; | |
1217 | } | |
9501f972 YH |
1218 | #define tcp_twsk_md5_key(twsk) NULL |
1219 | #endif | |
1220 | ||
765cf997 | 1221 | extern struct tcp_md5sig_pool __percpu *tcp_alloc_md5sig_pool(struct sock *); |
53d3176b | 1222 | extern void tcp_free_md5sig_pool(void); |
cfb6eeb4 | 1223 | |
35790c04 | 1224 | extern struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); |
53d3176b | 1225 | extern void tcp_put_md5sig_pool(void); |
35790c04 | 1226 | |
ca35a0ef | 1227 | extern int tcp_md5_hash_header(struct tcp_md5sig_pool *, const struct tcphdr *); |
cf533ea5 | 1228 | extern int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *, |
95c96174 | 1229 | unsigned int header_len); |
49a72dfb | 1230 | extern int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, |
cf533ea5 | 1231 | const struct tcp_md5sig_key *key); |
cfb6eeb4 | 1232 | |
fe067e8a DM |
1233 | /* write queue abstraction */ |
1234 | static inline void tcp_write_queue_purge(struct sock *sk) | |
1235 | { | |
1236 | struct sk_buff *skb; | |
1237 | ||
1238 | while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) | |
3ab224be HA |
1239 | sk_wmem_free_skb(sk, skb); |
1240 | sk_mem_reclaim(sk); | |
8818a9d8 | 1241 | tcp_clear_all_retrans_hints(tcp_sk(sk)); |
fe067e8a DM |
1242 | } |
1243 | ||
cf533ea5 | 1244 | static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) |
fe067e8a | 1245 | { |
cd07a8ea | 1246 | return skb_peek(&sk->sk_write_queue); |
fe067e8a DM |
1247 | } |
1248 | ||
cf533ea5 | 1249 | static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) |
fe067e8a | 1250 | { |
cd07a8ea | 1251 | return skb_peek_tail(&sk->sk_write_queue); |
fe067e8a DM |
1252 | } |
1253 | ||
cf533ea5 ED |
1254 | static inline struct sk_buff *tcp_write_queue_next(const struct sock *sk, |
1255 | const struct sk_buff *skb) | |
fe067e8a | 1256 | { |
cd07a8ea | 1257 | return skb_queue_next(&sk->sk_write_queue, skb); |
fe067e8a DM |
1258 | } |
1259 | ||
cf533ea5 ED |
1260 | static inline struct sk_buff *tcp_write_queue_prev(const struct sock *sk, |
1261 | const struct sk_buff *skb) | |
832d11c5 IJ |
1262 | { |
1263 | return skb_queue_prev(&sk->sk_write_queue, skb); | |
1264 | } | |
1265 | ||
fe067e8a | 1266 | #define tcp_for_write_queue(skb, sk) \ |
cd07a8ea | 1267 | skb_queue_walk(&(sk)->sk_write_queue, skb) |
fe067e8a DM |
1268 | |
1269 | #define tcp_for_write_queue_from(skb, sk) \ | |
cd07a8ea | 1270 | skb_queue_walk_from(&(sk)->sk_write_queue, skb) |
fe067e8a | 1271 | |
234b6860 | 1272 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
cd07a8ea | 1273 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
234b6860 | 1274 | |
cf533ea5 | 1275 | static inline struct sk_buff *tcp_send_head(const struct sock *sk) |
fe067e8a DM |
1276 | { |
1277 | return sk->sk_send_head; | |
1278 | } | |
1279 | ||
cd07a8ea DM |
1280 | static inline bool tcp_skb_is_last(const struct sock *sk, |
1281 | const struct sk_buff *skb) | |
1282 | { | |
1283 | return skb_queue_is_last(&sk->sk_write_queue, skb); | |
1284 | } | |
1285 | ||
cf533ea5 | 1286 | static inline void tcp_advance_send_head(struct sock *sk, const struct sk_buff *skb) |
fe067e8a | 1287 | { |
cd07a8ea | 1288 | if (tcp_skb_is_last(sk, skb)) |
fe067e8a | 1289 | sk->sk_send_head = NULL; |
cd07a8ea DM |
1290 | else |
1291 | sk->sk_send_head = tcp_write_queue_next(sk, skb); | |
fe067e8a DM |
1292 | } |
1293 | ||
1294 | static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked) | |
1295 | { | |
1296 | if (sk->sk_send_head == skb_unlinked) | |
1297 | sk->sk_send_head = NULL; | |
1298 | } | |
1299 | ||
1300 | static inline void tcp_init_send_head(struct sock *sk) | |
1301 | { | |
1302 | sk->sk_send_head = NULL; | |
1303 | } | |
1304 | ||
1305 | static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) | |
1306 | { | |
1307 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1308 | } | |
1309 | ||
1310 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) | |
1311 | { | |
1312 | __tcp_add_write_queue_tail(sk, skb); | |
1313 | ||
1314 | /* Queue it, remembering where we must start sending. */ | |
6859d494 | 1315 | if (sk->sk_send_head == NULL) { |
fe067e8a | 1316 | sk->sk_send_head = skb; |
6859d494 IJ |
1317 | |
1318 | if (tcp_sk(sk)->highest_sack == NULL) | |
1319 | tcp_sk(sk)->highest_sack = skb; | |
1320 | } | |
fe067e8a DM |
1321 | } |
1322 | ||
1323 | static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb) | |
1324 | { | |
1325 | __skb_queue_head(&sk->sk_write_queue, skb); | |
1326 | } | |
1327 | ||
1328 | /* Insert buff after skb on the write queue of sk. */ | |
1329 | static inline void tcp_insert_write_queue_after(struct sk_buff *skb, | |
1330 | struct sk_buff *buff, | |
1331 | struct sock *sk) | |
1332 | { | |
7de6c033 | 1333 | __skb_queue_after(&sk->sk_write_queue, skb, buff); |
fe067e8a DM |
1334 | } |
1335 | ||
43f59c89 | 1336 | /* Insert new before skb on the write queue of sk. */ |
fe067e8a DM |
1337 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
1338 | struct sk_buff *skb, | |
1339 | struct sock *sk) | |
1340 | { | |
43f59c89 | 1341 | __skb_queue_before(&sk->sk_write_queue, skb, new); |