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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> |
c6aefafb | 30 | #include <linux/cryptohash.h> |
435cf559 | 31 | #include <linux/kref.h> |
740b0f18 | 32 | #include <linux/ktime.h> |
3f421baa ACM |
33 | |
34 | #include <net/inet_connection_sock.h> | |
295ff7ed | 35 | #include <net/inet_timewait_sock.h> |
77d8bf9c | 36 | #include <net/inet_hashtables.h> |
1da177e4 | 37 | #include <net/checksum.h> |
2e6599cb | 38 | #include <net/request_sock.h> |
1da177e4 LT |
39 | #include <net/sock.h> |
40 | #include <net/snmp.h> | |
41 | #include <net/ip.h> | |
c752f073 | 42 | #include <net/tcp_states.h> |
bdf1ee5d | 43 | #include <net/inet_ecn.h> |
0c266898 | 44 | #include <net/dst.h> |
c752f073 | 45 | |
1da177e4 | 46 | #include <linux/seq_file.h> |
180d8cd9 | 47 | #include <linux/memcontrol.h> |
1da177e4 | 48 | |
40304b2a LB |
49 | #include <linux/bpf.h> |
50 | #include <linux/filter.h> | |
51 | #include <linux/bpf-cgroup.h> | |
52 | ||
6e04e021 | 53 | extern struct inet_hashinfo tcp_hashinfo; |
1da177e4 | 54 | |
dd24c001 | 55 | extern struct percpu_counter tcp_orphan_count; |
5c9f3023 | 56 | void tcp_time_wait(struct sock *sk, int state, int timeo); |
1da177e4 | 57 | |
1da177e4 | 58 | #define MAX_TCP_HEADER (128 + MAX_HEADER) |
33ad798c | 59 | #define MAX_TCP_OPTION_SPACE 40 |
1da177e4 | 60 | |
105970f6 | 61 | /* |
1da177e4 | 62 | * Never offer a window over 32767 without using window scaling. Some |
105970f6 | 63 | * poor stacks do signed 16bit maths! |
1da177e4 LT |
64 | */ |
65 | #define MAX_TCP_WINDOW 32767U | |
66 | ||
67 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ | |
68 | #define TCP_MIN_MSS 88U | |
69 | ||
5d424d5a | 70 | /* The least MTU to use for probing */ |
dcd8fb85 | 71 | #define TCP_BASE_MSS 1024 |
5d424d5a | 72 | |
05cbc0db FD |
73 | /* probing interval, default to 10 minutes as per RFC4821 */ |
74 | #define TCP_PROBE_INTERVAL 600 | |
75 | ||
6b58e0a5 FD |
76 | /* Specify interval when tcp mtu probing will stop */ |
77 | #define TCP_PROBE_THRESHOLD 8 | |
78 | ||
1da177e4 LT |
79 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
80 | #define TCP_FASTRETRANS_THRESH 3 | |
81 | ||
1da177e4 LT |
82 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
83 | #define TCP_MAX_QUICKACKS 16U | |
84 | ||
589c49cb GF |
85 | /* Maximal number of window scale according to RFC1323 */ |
86 | #define TCP_MAX_WSCALE 14U | |
87 | ||
1da177e4 LT |
88 | /* urg_data states */ |
89 | #define TCP_URG_VALID 0x0100 | |
90 | #define TCP_URG_NOTYET 0x0200 | |
91 | #define TCP_URG_READ 0x0400 | |
92 | ||
93 | #define TCP_RETR1 3 /* | |
94 | * This is how many retries it does before it | |
95 | * tries to figure out if the gateway is | |
96 | * down. Minimal RFC value is 3; it corresponds | |
97 | * to ~3sec-8min depending on RTO. | |
98 | */ | |
99 | ||
100 | #define TCP_RETR2 15 /* | |
101 | * This should take at least | |
102 | * 90 minutes to time out. | |
103 | * RFC1122 says that the limit is 100 sec. | |
104 | * 15 is ~13-30min depending on RTO. | |
105 | */ | |
106 | ||
6c9ff979 AB |
107 | #define TCP_SYN_RETRIES 6 /* This is how many retries are done |
108 | * when active opening a connection. | |
109 | * RFC1122 says the minimum retry MUST | |
110 | * be at least 180secs. Nevertheless | |
111 | * this value is corresponding to | |
112 | * 63secs of retransmission with the | |
113 | * current initial RTO. | |
114 | */ | |
1da177e4 | 115 | |
6c9ff979 AB |
116 | #define TCP_SYNACK_RETRIES 5 /* This is how may retries are done |
117 | * when passive opening a connection. | |
118 | * This is corresponding to 31secs of | |
119 | * retransmission with the current | |
120 | * initial RTO. | |
121 | */ | |
1da177e4 | 122 | |
1da177e4 LT |
123 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
124 | * state, about 60 seconds */ | |
125 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN | |
126 | /* BSD style FIN_WAIT2 deadlock breaker. | |
127 | * It used to be 3min, new value is 60sec, | |
128 | * to combine FIN-WAIT-2 timeout with | |
129 | * TIME-WAIT timer. | |
130 | */ | |
131 | ||
132 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ | |
133 | #if HZ >= 100 | |
134 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ | |
135 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) | |
136 | #else | |
137 | #define TCP_DELACK_MIN 4U | |
138 | #define TCP_ATO_MIN 4U | |
139 | #endif | |
140 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) | |
141 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) | |
bb4d991a | 142 | #define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ |
fd4f2cea | 143 | #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ |
9ad7c049 JC |
144 | #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now |
145 | * used as a fallback RTO for the | |
146 | * initial data transmission if no | |
147 | * valid RTT sample has been acquired, | |
148 | * most likely due to retrans in 3WHS. | |
149 | */ | |
1da177e4 LT |
150 | |
151 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes | |
152 | * for local resources. | |
153 | */ | |
1da177e4 LT |
154 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
155 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ | |
156 | #define TCP_KEEPALIVE_INTVL (75*HZ) | |
157 | ||
158 | #define MAX_TCP_KEEPIDLE 32767 | |
159 | #define MAX_TCP_KEEPINTVL 32767 | |
160 | #define MAX_TCP_KEEPCNT 127 | |
161 | #define MAX_TCP_SYNCNT 127 | |
162 | ||
163 | #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ | |
1da177e4 LT |
164 | |
165 | #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) | |
166 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated | |
167 | * after this time. It should be equal | |
168 | * (or greater than) TCP_TIMEWAIT_LEN | |
169 | * to provide reliability equal to one | |
170 | * provided by timewait state. | |
171 | */ | |
172 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host | |
173 | * timestamps. It must be less than | |
174 | * minimal timewait lifetime. | |
175 | */ | |
1da177e4 LT |
176 | /* |
177 | * TCP option | |
178 | */ | |
105970f6 | 179 | |
1da177e4 LT |
180 | #define TCPOPT_NOP 1 /* Padding */ |
181 | #define TCPOPT_EOL 0 /* End of options */ | |
182 | #define TCPOPT_MSS 2 /* Segment size negotiating */ | |
183 | #define TCPOPT_WINDOW 3 /* Window scaling */ | |
184 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ | |
185 | #define TCPOPT_SACK 5 /* SACK Block */ | |
186 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ | |
cfb6eeb4 | 187 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
7f9b838b | 188 | #define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ |
2100c8d2 YC |
189 | #define TCPOPT_EXP 254 /* Experimental */ |
190 | /* Magic number to be after the option value for sharing TCP | |
191 | * experimental options. See draft-ietf-tcpm-experimental-options-00.txt | |
192 | */ | |
193 | #define TCPOPT_FASTOPEN_MAGIC 0xF989 | |
1da177e4 LT |
194 | |
195 | /* | |
196 | * TCP option lengths | |
197 | */ | |
198 | ||
199 | #define TCPOLEN_MSS 4 | |
200 | #define TCPOLEN_WINDOW 3 | |
201 | #define TCPOLEN_SACK_PERM 2 | |
202 | #define TCPOLEN_TIMESTAMP 10 | |
cfb6eeb4 | 203 | #define TCPOLEN_MD5SIG 18 |
7f9b838b | 204 | #define TCPOLEN_FASTOPEN_BASE 2 |
2100c8d2 | 205 | #define TCPOLEN_EXP_FASTOPEN_BASE 4 |
1da177e4 LT |
206 | |
207 | /* But this is what stacks really send out. */ | |
208 | #define TCPOLEN_TSTAMP_ALIGNED 12 | |
209 | #define TCPOLEN_WSCALE_ALIGNED 4 | |
210 | #define TCPOLEN_SACKPERM_ALIGNED 4 | |
211 | #define TCPOLEN_SACK_BASE 2 | |
212 | #define TCPOLEN_SACK_BASE_ALIGNED 4 | |
213 | #define TCPOLEN_SACK_PERBLOCK 8 | |
cfb6eeb4 | 214 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
33ad798c | 215 | #define TCPOLEN_MSS_ALIGNED 4 |
1da177e4 | 216 | |
1da177e4 LT |
217 | /* Flags in tp->nonagle */ |
218 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ | |
219 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ | |
caa20d9a | 220 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
1da177e4 | 221 | |
36e31b0a AP |
222 | /* TCP thin-stream limits */ |
223 | #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ | |
224 | ||
21603fc4 | 225 | /* TCP initial congestion window as per rfc6928 */ |
442b9635 DM |
226 | #define TCP_INIT_CWND 10 |
227 | ||
cf60af03 YC |
228 | /* Bit Flags for sysctl_tcp_fastopen */ |
229 | #define TFO_CLIENT_ENABLE 1 | |
10467163 | 230 | #define TFO_SERVER_ENABLE 2 |
67da22d2 | 231 | #define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ |
cf60af03 | 232 | |
10467163 JC |
233 | /* Accept SYN data w/o any cookie option */ |
234 | #define TFO_SERVER_COOKIE_NOT_REQD 0x200 | |
235 | ||
236 | /* Force enable TFO on all listeners, i.e., not requiring the | |
cebc5cba | 237 | * TCP_FASTOPEN socket option. |
10467163 JC |
238 | */ |
239 | #define TFO_SERVER_WO_SOCKOPT1 0x400 | |
10467163 | 240 | |
295ff7ed | 241 | |
1da177e4 | 242 | /* sysctl variables for tcp */ |
1da177e4 LT |
243 | extern int sysctl_tcp_retrans_collapse; |
244 | extern int sysctl_tcp_stdurg; | |
245 | extern int sysctl_tcp_rfc1337; | |
246 | extern int sysctl_tcp_abort_on_overflow; | |
247 | extern int sysctl_tcp_max_orphans; | |
1da177e4 LT |
248 | extern int sysctl_tcp_fack; |
249 | extern int sysctl_tcp_reordering; | |
dca145ff | 250 | extern int sysctl_tcp_max_reordering; |
1da177e4 | 251 | extern int sysctl_tcp_dsack; |
a4fe34bf | 252 | extern long sysctl_tcp_mem[3]; |
1da177e4 LT |
253 | extern int sysctl_tcp_wmem[3]; |
254 | extern int sysctl_tcp_rmem[3]; | |
255 | extern int sysctl_tcp_app_win; | |
256 | extern int sysctl_tcp_adv_win_scale; | |
1da177e4 | 257 | extern int sysctl_tcp_frto; |
1da177e4 | 258 | extern int sysctl_tcp_nometrics_save; |
1da177e4 LT |
259 | extern int sysctl_tcp_moderate_rcvbuf; |
260 | extern int sysctl_tcp_tso_win_divisor; | |
15d99e02 | 261 | extern int sysctl_tcp_workaround_signed_windows; |
35089bb2 | 262 | extern int sysctl_tcp_slow_start_after_idle; |
36e31b0a | 263 | extern int sysctl_tcp_thin_linear_timeouts; |
7e380175 | 264 | extern int sysctl_tcp_thin_dupack; |
eed530b6 | 265 | extern int sysctl_tcp_early_retrans; |
a0370b3f YC |
266 | extern int sysctl_tcp_recovery; |
267 | #define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ | |
268 | ||
46d3ceab | 269 | extern int sysctl_tcp_limit_output_bytes; |
282f23c6 | 270 | extern int sysctl_tcp_challenge_ack_limit; |
95bd09eb | 271 | extern int sysctl_tcp_min_tso_segs; |
f6722583 | 272 | extern int sysctl_tcp_min_rtt_wlen; |
f54b3111 | 273 | extern int sysctl_tcp_autocorking; |
032ee423 | 274 | extern int sysctl_tcp_invalid_ratelimit; |
43e122b0 ED |
275 | extern int sysctl_tcp_pacing_ss_ratio; |
276 | extern int sysctl_tcp_pacing_ca_ratio; | |
1da177e4 | 277 | |
8d987e5c | 278 | extern atomic_long_t tcp_memory_allocated; |
1748376b | 279 | extern struct percpu_counter tcp_sockets_allocated; |
06044751 | 280 | extern unsigned long tcp_memory_pressure; |
1da177e4 | 281 | |
b8da51eb ED |
282 | /* optimized version of sk_under_memory_pressure() for TCP sockets */ |
283 | static inline bool tcp_under_memory_pressure(const struct sock *sk) | |
284 | { | |
baac50bb JW |
285 | if (mem_cgroup_sockets_enabled && sk->sk_memcg && |
286 | mem_cgroup_under_socket_pressure(sk->sk_memcg)) | |
e805605c | 287 | return true; |
b8da51eb ED |
288 | |
289 | return tcp_memory_pressure; | |
290 | } | |
1da177e4 LT |
291 | /* |
292 | * The next routines deal with comparing 32 bit unsigned ints | |
293 | * and worry about wraparound (automatic with unsigned arithmetic). | |
294 | */ | |
295 | ||
a2a385d6 | 296 | static inline bool before(__u32 seq1, __u32 seq2) |
1da177e4 | 297 | { |
0d630cc0 | 298 | return (__s32)(seq1-seq2) < 0; |
1da177e4 | 299 | } |
9a036b9c | 300 | #define after(seq2, seq1) before(seq1, seq2) |
1da177e4 LT |
301 | |
302 | /* is s2<=s1<=s3 ? */ | |
a2a385d6 | 303 | static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) |
1da177e4 LT |
304 | { |
305 | return seq3 - seq2 >= seq1 - seq2; | |
306 | } | |
307 | ||
efcdbf24 AS |
308 | static inline bool tcp_out_of_memory(struct sock *sk) |
309 | { | |
310 | if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && | |
311 | sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2)) | |
312 | return true; | |
313 | return false; | |
314 | } | |
315 | ||
a6c5ea4c ED |
316 | void sk_forced_mem_schedule(struct sock *sk, int size); |
317 | ||
ad1af0fe | 318 | static inline bool tcp_too_many_orphans(struct sock *sk, int shift) |
e4fd5da3 | 319 | { |
ad1af0fe DM |
320 | struct percpu_counter *ocp = sk->sk_prot->orphan_count; |
321 | int orphans = percpu_counter_read_positive(ocp); | |
322 | ||
323 | if (orphans << shift > sysctl_tcp_max_orphans) { | |
324 | orphans = percpu_counter_sum_positive(ocp); | |
325 | if (orphans << shift > sysctl_tcp_max_orphans) | |
326 | return true; | |
327 | } | |
ad1af0fe | 328 | return false; |
e4fd5da3 | 329 | } |
1da177e4 | 330 | |
5c9f3023 | 331 | bool tcp_check_oom(struct sock *sk, int shift); |
efcdbf24 | 332 | |
a0f82f64 | 333 | |
1da177e4 LT |
334 | extern struct proto tcp_prot; |
335 | ||
57ef42d5 | 336 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
13415e46 | 337 | #define __TCP_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
57ef42d5 | 338 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) |
aa2ea058 | 339 | #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) |
1da177e4 | 340 | |
5c9f3023 JP |
341 | void tcp_tasklet_init(void); |
342 | ||
343 | void tcp_v4_err(struct sk_buff *skb, u32); | |
344 | ||
345 | void tcp_shutdown(struct sock *sk, int how); | |
346 | ||
347 | void tcp_v4_early_demux(struct sk_buff *skb); | |
348 | int tcp_v4_rcv(struct sk_buff *skb); | |
349 | ||
350 | int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); | |
1b784140 | 351 | int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); |
306b13eb | 352 | int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size); |
5c9f3023 JP |
353 | int tcp_sendpage(struct sock *sk, struct page *page, int offset, size_t size, |
354 | int flags); | |
306b13eb TH |
355 | int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset, |
356 | size_t size, int flags); | |
e3b5616a DW |
357 | ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, |
358 | size_t size, int flags); | |
5c9f3023 JP |
359 | void tcp_release_cb(struct sock *sk); |
360 | void tcp_wfree(struct sk_buff *skb); | |
361 | void tcp_write_timer_handler(struct sock *sk); | |
362 | void tcp_delack_timer_handler(struct sock *sk); | |
363 | int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg); | |
72ab4a86 | 364 | int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); |
5c9f3023 | 365 | void tcp_rcv_established(struct sock *sk, struct sk_buff *skb, |
e42e24c3 | 366 | const struct tcphdr *th); |
5c9f3023 | 367 | void tcp_rcv_space_adjust(struct sock *sk); |
5c9f3023 JP |
368 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); |
369 | void tcp_twsk_destructor(struct sock *sk); | |
370 | ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, | |
371 | struct pipe_inode_info *pipe, size_t len, | |
372 | unsigned int flags); | |
9c55e01c | 373 | |
463c84b9 ACM |
374 | static inline void tcp_dec_quickack_mode(struct sock *sk, |
375 | const unsigned int pkts) | |
1da177e4 | 376 | { |
463c84b9 | 377 | struct inet_connection_sock *icsk = inet_csk(sk); |
fc6415bc | 378 | |
463c84b9 ACM |
379 | if (icsk->icsk_ack.quick) { |
380 | if (pkts >= icsk->icsk_ack.quick) { | |
381 | icsk->icsk_ack.quick = 0; | |
fc6415bc | 382 | /* Leaving quickack mode we deflate ATO. */ |
463c84b9 | 383 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
fc6415bc | 384 | } else |
463c84b9 | 385 | icsk->icsk_ack.quick -= pkts; |
1da177e4 LT |
386 | } |
387 | } | |
388 | ||
bdf1ee5d IJ |
389 | #define TCP_ECN_OK 1 |
390 | #define TCP_ECN_QUEUE_CWR 2 | |
391 | #define TCP_ECN_DEMAND_CWR 4 | |
7a269ffa | 392 | #define TCP_ECN_SEEN 8 |
bdf1ee5d | 393 | |
fd2c3ef7 | 394 | enum tcp_tw_status { |
1da177e4 LT |
395 | TCP_TW_SUCCESS = 0, |
396 | TCP_TW_RST = 1, | |
397 | TCP_TW_ACK = 2, | |
398 | TCP_TW_SYN = 3 | |
399 | }; | |
400 | ||
401 | ||
5c9f3023 JP |
402 | enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
403 | struct sk_buff *skb, | |
404 | const struct tcphdr *th); | |
405 | struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, | |
52452c54 | 406 | struct request_sock *req, bool fastopen); |
5c9f3023 JP |
407 | int tcp_child_process(struct sock *parent, struct sock *child, |
408 | struct sk_buff *skb); | |
5ae344c9 | 409 | void tcp_enter_loss(struct sock *sk); |
57dde7f7 | 410 | void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int flag); |
5c9f3023 JP |
411 | void tcp_clear_retrans(struct tcp_sock *tp); |
412 | void tcp_update_metrics(struct sock *sk); | |
413 | void tcp_init_metrics(struct sock *sk); | |
414 | void tcp_metrics_init(void); | |
d82bae12 | 415 | bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst); |
5c9f3023 JP |
416 | void tcp_disable_fack(struct tcp_sock *tp); |
417 | void tcp_close(struct sock *sk, long timeout); | |
418 | void tcp_init_sock(struct sock *sk); | |
419 | unsigned int tcp_poll(struct file *file, struct socket *sock, | |
420 | struct poll_table_struct *wait); | |
421 | int tcp_getsockopt(struct sock *sk, int level, int optname, | |
422 | char __user *optval, int __user *optlen); | |
423 | int tcp_setsockopt(struct sock *sk, int level, int optname, | |
424 | char __user *optval, unsigned int optlen); | |
425 | int compat_tcp_getsockopt(struct sock *sk, int level, int optname, | |
53d3176b | 426 | char __user *optval, int __user *optlen); |
5c9f3023 | 427 | int compat_tcp_setsockopt(struct sock *sk, int level, int optname, |
53d3176b | 428 | char __user *optval, unsigned int optlen); |
5c9f3023 | 429 | void tcp_set_keepalive(struct sock *sk, int val); |
42cb80a2 | 430 | void tcp_syn_ack_timeout(const struct request_sock *req); |
1b784140 YX |
431 | int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, |
432 | int flags, int *addr_len); | |
eed29f17 | 433 | void tcp_parse_options(const struct net *net, const struct sk_buff *skb, |
5c9f3023 JP |
434 | struct tcp_options_received *opt_rx, |
435 | int estab, struct tcp_fastopen_cookie *foc); | |
436 | const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); | |
7d5d5525 | 437 | |
1da177e4 LT |
438 | /* |
439 | * TCP v4 functions exported for the inet6 API | |
440 | */ | |
441 | ||
5c9f3023 | 442 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
4fab9071 | 443 | void tcp_v4_mtu_reduced(struct sock *sk); |
9cf74903 | 444 | void tcp_req_err(struct sock *sk, u32 seq, bool abort); |
5c9f3023 | 445 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); |
c28c6f04 | 446 | struct sock *tcp_create_openreq_child(const struct sock *sk, |
5c9f3023 JP |
447 | struct request_sock *req, |
448 | struct sk_buff *skb); | |
81164413 | 449 | void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); |
0c27171e | 450 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
5c9f3023 | 451 | struct request_sock *req, |
5e0724d0 ED |
452 | struct dst_entry *dst, |
453 | struct request_sock *req_unhash, | |
454 | bool *own_req); | |
5c9f3023 JP |
455 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); |
456 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); | |
457 | int tcp_connect(struct sock *sk); | |
b3d05147 ED |
458 | enum tcp_synack_type { |
459 | TCP_SYNACK_NORMAL, | |
460 | TCP_SYNACK_FASTOPEN, | |
461 | TCP_SYNACK_COOKIE, | |
462 | }; | |
5d062de7 | 463 | struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, |
5c9f3023 | 464 | struct request_sock *req, |
ca6fb065 | 465 | struct tcp_fastopen_cookie *foc, |
b3d05147 | 466 | enum tcp_synack_type synack_type); |
5c9f3023 | 467 | int tcp_disconnect(struct sock *sk, int flags); |
1da177e4 | 468 | |
370816ae | 469 | void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); |
292e8d8c | 470 | int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); |
63d02d15 | 471 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); |
1da177e4 | 472 | |
1da177e4 | 473 | /* From syncookies.c */ |
b80c0e78 ED |
474 | struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, |
475 | struct request_sock *req, | |
84b114b9 | 476 | struct dst_entry *dst, u32 tsoff); |
5c9f3023 JP |
477 | int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, |
478 | u32 cookie); | |
461b74c3 | 479 | struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); |
e05c82d3 | 480 | #ifdef CONFIG_SYN_COOKIES |
8c27bd75 | 481 | |
63262315 | 482 | /* Syncookies use a monotonic timer which increments every 60 seconds. |
8c27bd75 FW |
483 | * This counter is used both as a hash input and partially encoded into |
484 | * the cookie value. A cookie is only validated further if the delta | |
485 | * between the current counter value and the encoded one is less than this, | |
63262315 | 486 | * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if |
8c27bd75 FW |
487 | * the counter advances immediately after a cookie is generated). |
488 | */ | |
264ea103 ED |
489 | #define MAX_SYNCOOKIE_AGE 2 |
490 | #define TCP_SYNCOOKIE_PERIOD (60 * HZ) | |
491 | #define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) | |
492 | ||
493 | /* syncookies: remember time of last synqueue overflow | |
494 | * But do not dirty this field too often (once per second is enough) | |
3f684b4b | 495 | * It is racy as we do not hold a lock, but race is very minor. |
264ea103 | 496 | */ |
3f684b4b | 497 | static inline void tcp_synq_overflow(const struct sock *sk) |
264ea103 ED |
498 | { |
499 | unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; | |
500 | unsigned long now = jiffies; | |
501 | ||
502 | if (time_after(now, last_overflow + HZ)) | |
503 | tcp_sk(sk)->rx_opt.ts_recent_stamp = now; | |
504 | } | |
505 | ||
506 | /* syncookies: no recent synqueue overflow on this listening socket? */ | |
507 | static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) | |
508 | { | |
509 | unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; | |
510 | ||
511 | return time_after(jiffies, last_overflow + TCP_SYNCOOKIE_VALID); | |
512 | } | |
8c27bd75 FW |
513 | |
514 | static inline u32 tcp_cookie_time(void) | |
515 | { | |
63262315 ED |
516 | u64 val = get_jiffies_64(); |
517 | ||
264ea103 | 518 | do_div(val, TCP_SYNCOOKIE_PERIOD); |
63262315 | 519 | return val; |
8c27bd75 FW |
520 | } |
521 | ||
5c9f3023 JP |
522 | u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, |
523 | u16 *mssp); | |
3f684b4b | 524 | __u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); |
9a568de4 | 525 | u64 cookie_init_timestamp(struct request_sock *req); |
f9301034 ED |
526 | bool cookie_timestamp_decode(const struct net *net, |
527 | struct tcp_options_received *opt); | |
f1673381 | 528 | bool cookie_ecn_ok(const struct tcp_options_received *opt, |
f7b3bec6 | 529 | const struct net *net, const struct dst_entry *dst); |
4dfc2817 | 530 | |
c6aefafb | 531 | /* From net/ipv6/syncookies.c */ |
5c9f3023 JP |
532 | int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, |
533 | u32 cookie); | |
534 | struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); | |
f1673381 | 535 | |
5c9f3023 JP |
536 | u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, |
537 | const struct tcphdr *th, u16 *mssp); | |
3f684b4b | 538 | __u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); |
e05c82d3 | 539 | #endif |
1da177e4 LT |
540 | /* tcp_output.c */ |
541 | ||
1b3878ca NC |
542 | u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now, |
543 | int min_tso_segs); | |
5c9f3023 JP |
544 | void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
545 | int nonagle); | |
10d3be56 ED |
546 | int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
547 | int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); | |
5c9f3023 JP |
548 | void tcp_retransmit_timer(struct sock *sk); |
549 | void tcp_xmit_retransmit_queue(struct sock *); | |
550 | void tcp_simple_retransmit(struct sock *); | |
57dde7f7 | 551 | void tcp_enter_recovery(struct sock *sk, bool ece_ack); |
5c9f3023 | 552 | int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
6cc55e09 | 553 | int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int, gfp_t); |
5c9f3023 JP |
554 | |
555 | void tcp_send_probe0(struct sock *); | |
556 | void tcp_send_partial(struct sock *); | |
e520af48 | 557 | int tcp_write_wakeup(struct sock *, int mib); |
5c9f3023 JP |
558 | void tcp_send_fin(struct sock *sk); |
559 | void tcp_send_active_reset(struct sock *sk, gfp_t priority); | |
560 | int tcp_send_synack(struct sock *); | |
5c9f3023 JP |
561 | void tcp_push_one(struct sock *, unsigned int mss_now); |
562 | void tcp_send_ack(struct sock *sk); | |
563 | void tcp_send_delayed_ack(struct sock *sk); | |
564 | void tcp_send_loss_probe(struct sock *sk); | |
565 | bool tcp_schedule_loss_probe(struct sock *sk); | |
cfea5a68 MKL |
566 | void tcp_skb_collapse_tstamp(struct sk_buff *skb, |
567 | const struct sk_buff *next_skb); | |
1da177e4 | 568 | |
a762a980 | 569 | /* tcp_input.c */ |
5c9f3023 | 570 | void tcp_rearm_rto(struct sock *sk); |
0f1c28ae | 571 | void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); |
5c9f3023 | 572 | void tcp_reset(struct sock *sk); |
4f41b1c5 | 573 | void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb); |
e3e17b77 | 574 | void tcp_fin(struct sock *sk); |
a762a980 | 575 | |
1da177e4 | 576 | /* tcp_timer.c */ |
5c9f3023 | 577 | void tcp_init_xmit_timers(struct sock *); |
463c84b9 ACM |
578 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
579 | { | |
218af599 | 580 | hrtimer_cancel(&tcp_sk(sk)->pacing_timer); |
463c84b9 ACM |
581 | inet_csk_clear_xmit_timers(sk); |
582 | } | |
1da177e4 | 583 | |
5c9f3023 JP |
584 | unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
585 | unsigned int tcp_current_mss(struct sock *sk); | |
0c54b85f IJ |
586 | |
587 | /* Bound MSS / TSO packet size with the half of the window */ | |
588 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) | |
589 | { | |
01f83d69 AK |
590 | int cutoff; |
591 | ||
592 | /* When peer uses tiny windows, there is no use in packetizing | |
593 | * to sub-MSS pieces for the sake of SWS or making sure there | |
594 | * are enough packets in the pipe for fast recovery. | |
595 | * | |
596 | * On the other hand, for extremely large MSS devices, handling | |
597 | * smaller than MSS windows in this way does make sense. | |
598 | */ | |
2631b79f | 599 | if (tp->max_window > TCP_MSS_DEFAULT) |
01f83d69 AK |
600 | cutoff = (tp->max_window >> 1); |
601 | else | |
602 | cutoff = tp->max_window; | |
603 | ||
604 | if (cutoff && pktsize > cutoff) | |
605 | return max_t(int, cutoff, 68U - tp->tcp_header_len); | |
0c54b85f IJ |
606 | else |
607 | return pktsize; | |
608 | } | |
1da177e4 | 609 | |
17b085ea | 610 | /* tcp.c */ |
0df48c26 | 611 | void tcp_get_info(struct sock *, struct tcp_info *); |
1da177e4 LT |
612 | |
613 | /* Read 'sendfile()'-style from a TCP socket */ | |
5c9f3023 JP |
614 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
615 | sk_read_actor_t recv_actor); | |
1da177e4 | 616 | |
5c9f3023 | 617 | void tcp_initialize_rcv_mss(struct sock *sk); |
1da177e4 | 618 | |
5c9f3023 JP |
619 | int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
620 | int tcp_mss_to_mtu(struct sock *sk, int mss); | |
621 | void tcp_mtup_init(struct sock *sk); | |
622 | void tcp_init_buffer_space(struct sock *sk); | |
5d424d5a | 623 | |
f1ecd5d9 DL |
624 | static inline void tcp_bound_rto(const struct sock *sk) |
625 | { | |
626 | if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) | |
627 | inet_csk(sk)->icsk_rto = TCP_RTO_MAX; | |
628 | } | |
629 | ||
630 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) | |
631 | { | |
740b0f18 | 632 | return usecs_to_jiffies((tp->srtt_us >> 3) + tp->rttvar_us); |
f1ecd5d9 DL |
633 | } |
634 | ||
31770e34 FW |
635 | static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
636 | { | |
637 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | | |
638 | ntohl(TCP_FLAG_ACK) | | |
639 | snd_wnd); | |
640 | } | |
641 | ||
642 | static inline void tcp_fast_path_on(struct tcp_sock *tp) | |
643 | { | |
644 | __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); | |
645 | } | |
646 | ||
647 | static inline void tcp_fast_path_check(struct sock *sk) | |
648 | { | |
649 | struct tcp_sock *tp = tcp_sk(sk); | |
650 | ||
651 | if (RB_EMPTY_ROOT(&tp->out_of_order_queue) && | |
652 | tp->rcv_wnd && | |
653 | atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && | |
654 | !tp->urg_data) | |
655 | tcp_fast_path_on(tp); | |
656 | } | |
657 | ||
0c266898 SS |
658 | /* Compute the actual rto_min value */ |
659 | static inline u32 tcp_rto_min(struct sock *sk) | |
660 | { | |
cf533ea5 | 661 | const struct dst_entry *dst = __sk_dst_get(sk); |
0c266898 SS |
662 | u32 rto_min = TCP_RTO_MIN; |
663 | ||
664 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) | |
665 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); | |
666 | return rto_min; | |
667 | } | |
668 | ||
740b0f18 ED |
669 | static inline u32 tcp_rto_min_us(struct sock *sk) |
670 | { | |
671 | return jiffies_to_usecs(tcp_rto_min(sk)); | |
672 | } | |
673 | ||
81164413 DB |
674 | static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) |
675 | { | |
676 | return dst_metric_locked(dst, RTAX_CC_ALGO); | |
677 | } | |
678 | ||
f6722583 YC |
679 | /* Minimum RTT in usec. ~0 means not available. */ |
680 | static inline u32 tcp_min_rtt(const struct tcp_sock *tp) | |
681 | { | |
64033892 | 682 | return minmax_get(&tp->rtt_min); |
f6722583 YC |
683 | } |
684 | ||
1da177e4 LT |
685 | /* Compute the actual receive window we are currently advertising. |
686 | * Rcv_nxt can be after the window if our peer push more data | |
687 | * than the offered window. | |
688 | */ | |
40efc6fa | 689 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
1da177e4 LT |
690 | { |
691 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; | |
692 | ||
693 | if (win < 0) | |
694 | win = 0; | |
695 | return (u32) win; | |
696 | } | |
697 | ||
698 | /* Choose a new window, without checks for shrinking, and without | |
699 | * scaling applied to the result. The caller does these things | |
700 | * if necessary. This is a "raw" window selection. | |
701 | */ | |
5c9f3023 | 702 | u32 __tcp_select_window(struct sock *sk); |
1da177e4 | 703 | |
ee995283 PE |
704 | void tcp_send_window_probe(struct sock *sk); |
705 | ||
ec66eda8 ED |
706 | /* TCP uses 32bit jiffies to save some space. |
707 | * Note that this is different from tcp_time_stamp, which | |
708 | * historically has been the same until linux-4.13. | |
709 | */ | |
710 | #define tcp_jiffies32 ((u32)jiffies) | |
711 | ||
9a568de4 ED |
712 | /* |
713 | * Deliver a 32bit value for TCP timestamp option (RFC 7323) | |
714 | * It is no longer tied to jiffies, but to 1 ms clock. | |
715 | * Note: double check if you want to use tcp_jiffies32 instead of this. | |
716 | */ | |
717 | #define TCP_TS_HZ 1000 | |
718 | ||
719 | static inline u64 tcp_clock_ns(void) | |
720 | { | |
721 | return local_clock(); | |
722 | } | |
723 | ||
724 | static inline u64 tcp_clock_us(void) | |
725 | { | |
726 | return div_u64(tcp_clock_ns(), NSEC_PER_USEC); | |
727 | } | |
728 | ||
729 | /* This should only be used in contexts where tp->tcp_mstamp is up to date */ | |
730 | static inline u32 tcp_time_stamp(const struct tcp_sock *tp) | |
731 | { | |
732 | return div_u64(tp->tcp_mstamp, USEC_PER_SEC / TCP_TS_HZ); | |
733 | } | |
734 | ||
735 | /* Could use tcp_clock_us() / 1000, but this version uses a single divide */ | |
736 | static inline u32 tcp_time_stamp_raw(void) | |
737 | { | |
738 | return div_u64(tcp_clock_ns(), NSEC_PER_SEC / TCP_TS_HZ); | |
739 | } | |
740 | ||
741 | ||
742 | /* Refresh 1us clock of a TCP socket, | |
743 | * ensuring monotically increasing values. | |
1da177e4 | 744 | */ |
9a568de4 ED |
745 | static inline void tcp_mstamp_refresh(struct tcp_sock *tp) |
746 | { | |
747 | u64 val = tcp_clock_us(); | |
748 | ||
749 | if (val > tp->tcp_mstamp) | |
750 | tp->tcp_mstamp = val; | |
751 | } | |
752 | ||
753 | static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) | |
754 | { | |
755 | return max_t(s64, t1 - t0, 0); | |
756 | } | |
1da177e4 | 757 | |
7faee5c0 ED |
758 | static inline u32 tcp_skb_timestamp(const struct sk_buff *skb) |
759 | { | |
9a568de4 | 760 | return div_u64(skb->skb_mstamp, USEC_PER_SEC / TCP_TS_HZ); |
7faee5c0 ED |
761 | } |
762 | ||
763 | ||
a3433f35 CG |
764 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
765 | ||
766 | #define TCPHDR_FIN 0x01 | |
767 | #define TCPHDR_SYN 0x02 | |
768 | #define TCPHDR_RST 0x04 | |
769 | #define TCPHDR_PSH 0x08 | |
770 | #define TCPHDR_ACK 0x10 | |
771 | #define TCPHDR_URG 0x20 | |
772 | #define TCPHDR_ECE 0x40 | |
773 | #define TCPHDR_CWR 0x80 | |
774 | ||
49213555 DB |
775 | #define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) |
776 | ||
caa20d9a | 777 | /* This is what the send packet queuing engine uses to pass |
f86586fa ED |
778 | * TCP per-packet control information to the transmission code. |
779 | * We also store the host-order sequence numbers in here too. | |
780 | * This is 44 bytes if IPV6 is enabled. | |
781 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. | |
1da177e4 LT |
782 | */ |
783 | struct tcp_skb_cb { | |
1da177e4 LT |
784 | __u32 seq; /* Starting sequence number */ |
785 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ | |
cd7d8498 ED |
786 | union { |
787 | /* Note : tcp_tw_isn is used in input path only | |
788 | * (isn chosen by tcp_timewait_state_process()) | |
789 | * | |
f69ad292 ED |
790 | * tcp_gso_segs/size are used in write queue only, |
791 | * cf tcp_skb_pcount()/tcp_skb_mss() | |
cd7d8498 ED |
792 | */ |
793 | __u32 tcp_tw_isn; | |
f69ad292 ED |
794 | struct { |
795 | u16 tcp_gso_segs; | |
796 | u16 tcp_gso_size; | |
797 | }; | |
cd7d8498 | 798 | }; |
4de075e0 | 799 | __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ |
f4f9f6e7 | 800 | |
1da177e4 LT |
801 | __u8 sacked; /* State flags for SACK/FACK. */ |
802 | #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ | |
803 | #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ | |
804 | #define TCPCB_LOST 0x04 /* SKB is lost */ | |
805 | #define TCPCB_TAGBITS 0x07 /* All tag bits */ | |
9d186cac | 806 | #define TCPCB_REPAIRED 0x10 /* SKB repaired (no skb_mstamp) */ |
1da177e4 | 807 | #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ |
9d186cac AV |
808 | #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS| \ |
809 | TCPCB_REPAIRED) | |
1da177e4 | 810 | |
f4f9f6e7 | 811 | __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ |
6b084928 | 812 | __u8 txstamp_ack:1, /* Record TX timestamp for ack? */ |
c134ecb8 | 813 | eor:1, /* Is skb MSG_EOR marked? */ |
98aaa913 MM |
814 | has_rxtstamp:1, /* SKB has a RX timestamp */ |
815 | unused:5; | |
1da177e4 | 816 | __u32 ack_seq; /* Sequence number ACK'd */ |
971f10ec | 817 | union { |
b75803d5 | 818 | struct { |
b9f64820 | 819 | /* There is space for up to 24 bytes */ |
d7722e85 SHY |
820 | __u32 in_flight:30,/* Bytes in flight at transmit */ |
821 | is_app_limited:1, /* cwnd not fully used? */ | |
822 | unused:1; | |
b9f64820 YC |
823 | /* pkts S/ACKed so far upon tx of skb, incl retrans: */ |
824 | __u32 delivered; | |
825 | /* start of send pipeline phase */ | |
9a568de4 | 826 | u64 first_tx_mstamp; |
b9f64820 | 827 | /* when we reached the "delivered" count */ |
9a568de4 | 828 | u64 delivered_mstamp; |
b75803d5 LB |
829 | } tx; /* only used for outgoing skbs */ |
830 | union { | |
831 | struct inet_skb_parm h4; | |
971f10ec | 832 | #if IS_ENABLED(CONFIG_IPV6) |
b75803d5 | 833 | struct inet6_skb_parm h6; |
971f10ec | 834 | #endif |
b75803d5 LB |
835 | } header; /* For incoming skbs */ |
836 | }; | |
1da177e4 LT |
837 | }; |
838 | ||
839 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) | |
840 | ||
870c3151 | 841 | |
815afe17 | 842 | #if IS_ENABLED(CONFIG_IPV6) |
870c3151 ED |
843 | /* This is the variant of inet6_iif() that must be used by TCP, |
844 | * as TCP moves IP6CB into a different location in skb->cb[] | |
845 | */ | |
846 | static inline int tcp_v6_iif(const struct sk_buff *skb) | |
847 | { | |
a04a480d | 848 | bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); |
74b20582 DA |
849 | |
850 | return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; | |
870c3151 | 851 | } |
4297a0ef DA |
852 | |
853 | /* TCP_SKB_CB reference means this can not be used from early demux */ | |
854 | static inline int tcp_v6_sdif(const struct sk_buff *skb) | |
855 | { | |
856 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) | |
857 | if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags)) | |
858 | return TCP_SKB_CB(skb)->header.h6.iif; | |
859 | #endif | |
860 | return 0; | |
861 | } | |
815afe17 | 862 | #endif |
870c3151 | 863 | |
a04a480d DA |
864 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
865 | static inline bool inet_exact_dif_match(struct net *net, struct sk_buff *skb) | |
866 | { | |
867 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) | |
868 | if (!net->ipv4.sysctl_tcp_l3mdev_accept && | |
da96786e | 869 | skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) |
a04a480d DA |
870 | return true; |
871 | #endif | |
872 | return false; | |
873 | } | |
874 | ||
3fa6f616 DA |
875 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
876 | static inline int tcp_v4_sdif(struct sk_buff *skb) | |
877 | { | |
878 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) | |
879 | if (skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) | |
880 | return TCP_SKB_CB(skb)->header.h4.iif; | |
881 | #endif | |
882 | return 0; | |
883 | } | |
884 | ||
1da177e4 LT |
885 | /* Due to TSO, an SKB can be composed of multiple actual |
886 | * packets. To keep these tracked properly, we use this. | |
bd14b1b2 | 887 | */ |
1da177e4 | 888 | static inline int tcp_skb_pcount(const struct sk_buff *skb) |
bd14b1b2 | 889 | { |
cd7d8498 ED |
890 | return TCP_SKB_CB(skb)->tcp_gso_segs; |
891 | } | |
bd14b1b2 | 892 | |
cd7d8498 ED |
893 | static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) |
894 | { | |
895 | TCP_SKB_CB(skb)->tcp_gso_segs = segs; | |
bd14b1b2 ED |
896 | } |
897 | ||
cd7d8498 | 898 | static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) |
1da177e4 | 899 | { |
cd7d8498 | 900 | TCP_SKB_CB(skb)->tcp_gso_segs += segs; |
1da177e4 LT |
901 | } |
902 | ||
f69ad292 | 903 | /* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ |
1da177e4 LT |
904 | static inline int tcp_skb_mss(const struct sk_buff *skb) |
905 | { | |
f69ad292 | 906 | return TCP_SKB_CB(skb)->tcp_gso_size; |
1da177e4 LT |
907 | } |
908 | ||
c134ecb8 MKL |
909 | static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) |
910 | { | |
911 | return likely(!TCP_SKB_CB(skb)->eor); | |
912 | } | |
913 | ||
317a76f9 SH |
914 | /* Events passed to congestion control interface */ |
915 | enum tcp_ca_event { | |
916 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ | |
917 | CA_EVENT_CWND_RESTART, /* congestion window restart */ | |
918 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ | |
317a76f9 | 919 | CA_EVENT_LOSS, /* loss timeout */ |
9890092e FW |
920 | CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ |
921 | CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ | |
922 | CA_EVENT_DELAYED_ACK, /* Delayed ack is sent */ | |
923 | CA_EVENT_NON_DELAYED_ACK, | |
7354c8c3 FW |
924 | }; |
925 | ||
9890092e | 926 | /* Information about inbound ACK, passed to cong_ops->in_ack_event() */ |
7354c8c3 | 927 | enum tcp_ca_ack_event_flags { |
c1d2b4c3 FW |
928 | CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ |
929 | CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ | |
930 | CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ | |
317a76f9 SH |
931 | }; |
932 | ||
933 | /* | |
934 | * Interface for adding new TCP congestion control handlers | |
935 | */ | |
936 | #define TCP_CA_NAME_MAX 16 | |
3ff825b2 SH |
937 | #define TCP_CA_MAX 128 |
938 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) | |
939 | ||
c5c6a8ab DB |
940 | #define TCP_CA_UNSPEC 0 |
941 | ||
30e502a3 | 942 | /* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ |
164891aa | 943 | #define TCP_CONG_NON_RESTRICTED 0x1 |
30e502a3 DB |
944 | /* Requires ECN/ECT set on all packets */ |
945 | #define TCP_CONG_NEEDS_ECN 0x2 | |
164891aa | 946 | |
64f40ff5 ED |
947 | union tcp_cc_info; |
948 | ||
756ee172 LB |
949 | struct ack_sample { |
950 | u32 pkts_acked; | |
951 | s32 rtt_us; | |
6f094b9e | 952 | u32 in_flight; |
756ee172 LB |
953 | }; |
954 | ||
b9f64820 YC |
955 | /* A rate sample measures the number of (original/retransmitted) data |
956 | * packets delivered "delivered" over an interval of time "interval_us". | |
957 | * The tcp_rate.c code fills in the rate sample, and congestion | |
958 | * control modules that define a cong_control function to run at the end | |
959 | * of ACK processing can optionally chose to consult this sample when | |
960 | * setting cwnd and pacing rate. | |
961 | * A sample is invalid if "delivered" or "interval_us" is negative. | |
962 | */ | |
963 | struct rate_sample { | |
9a568de4 | 964 | u64 prior_mstamp; /* starting timestamp for interval */ |
b9f64820 YC |
965 | u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ |
966 | s32 delivered; /* number of packets delivered over interval */ | |
967 | long interval_us; /* time for tp->delivered to incr "delivered" */ | |
968 | long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ | |
969 | int losses; /* number of packets marked lost upon ACK */ | |
970 | u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ | |
971 | u32 prior_in_flight; /* in flight before this ACK */ | |
d7722e85 | 972 | bool is_app_limited; /* is sample from packet with bubble in pipe? */ |
b9f64820 YC |
973 | bool is_retrans; /* is sample from retransmission? */ |
974 | }; | |
975 | ||
317a76f9 SH |
976 | struct tcp_congestion_ops { |
977 | struct list_head list; | |
c5c6a8ab DB |
978 | u32 key; |
979 | u32 flags; | |
317a76f9 SH |
980 | |
981 | /* initialize private data (optional) */ | |
6687e988 | 982 | void (*init)(struct sock *sk); |
317a76f9 | 983 | /* cleanup private data (optional) */ |
6687e988 | 984 | void (*release)(struct sock *sk); |
317a76f9 SH |
985 | |
986 | /* return slow start threshold (required) */ | |
6687e988 | 987 | u32 (*ssthresh)(struct sock *sk); |
317a76f9 | 988 | /* do new cwnd calculation (required) */ |
24901551 | 989 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); |
317a76f9 | 990 | /* call before changing ca_state (optional) */ |
6687e988 | 991 | void (*set_state)(struct sock *sk, u8 new_state); |
317a76f9 | 992 | /* call when cwnd event occurs (optional) */ |
6687e988 | 993 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
7354c8c3 FW |
994 | /* call when ack arrives (optional) */ |
995 | void (*in_ack_event)(struct sock *sk, u32 flags); | |
1e0ce2a1 | 996 | /* new value of cwnd after loss (required) */ |
6687e988 | 997 | u32 (*undo_cwnd)(struct sock *sk); |
317a76f9 | 998 | /* hook for packet ack accounting (optional) */ |
756ee172 | 999 | void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); |
ed6e7268 NC |
1000 | /* suggest number of segments for each skb to transmit (optional) */ |
1001 | u32 (*tso_segs_goal)(struct sock *sk); | |
77bfc174 YC |
1002 | /* returns the multiplier used in tcp_sndbuf_expand (optional) */ |
1003 | u32 (*sndbuf_expand)(struct sock *sk); | |
c0402760 YC |
1004 | /* call when packets are delivered to update cwnd and pacing rate, |
1005 | * after all the ca_state processing. (optional) | |
1006 | */ | |
1007 | void (*cong_control)(struct sock *sk, const struct rate_sample *rs); | |
73c1f4a0 | 1008 | /* get info for inet_diag (optional) */ |
64f40ff5 ED |
1009 | size_t (*get_info)(struct sock *sk, u32 ext, int *attr, |
1010 | union tcp_cc_info *info); | |
317a76f9 SH |
1011 | |
1012 | char name[TCP_CA_NAME_MAX]; | |
1013 | struct module *owner; | |
1014 | }; | |
1015 | ||
5c9f3023 JP |
1016 | int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
1017 | void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); | |
317a76f9 | 1018 | |
55d8694f | 1019 | void tcp_assign_congestion_control(struct sock *sk); |
5c9f3023 JP |
1020 | void tcp_init_congestion_control(struct sock *sk); |
1021 | void tcp_cleanup_congestion_control(struct sock *sk); | |
1022 | int tcp_set_default_congestion_control(const char *name); | |
1023 | void tcp_get_default_congestion_control(char *name); | |
1024 | void tcp_get_available_congestion_control(char *buf, size_t len); | |
1025 | void tcp_get_allowed_congestion_control(char *buf, size_t len); | |
1026 | int tcp_set_allowed_congestion_control(char *allowed); | |
ebfa00c5 | 1027 | int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, bool reinit); |
e73ebb08 NC |
1028 | u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); |
1029 | void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); | |
317a76f9 | 1030 | |
5c9f3023 | 1031 | u32 tcp_reno_ssthresh(struct sock *sk); |
e9799183 | 1032 | u32 tcp_reno_undo_cwnd(struct sock *sk); |
24901551 | 1033 | void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); |
a8acfbac | 1034 | extern struct tcp_congestion_ops tcp_reno; |
317a76f9 | 1035 | |
c5c6a8ab | 1036 | struct tcp_congestion_ops *tcp_ca_find_key(u32 key); |
c3a8d947 | 1037 | u32 tcp_ca_get_key_by_name(const char *name, bool *ecn_ca); |
ea697639 | 1038 | #ifdef CONFIG_INET |
c5c6a8ab | 1039 | char *tcp_ca_get_name_by_key(u32 key, char *buffer); |
ea697639 DB |
1040 | #else |
1041 | static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) | |
1042 | { | |
1043 | return NULL; | |
1044 | } | |
1045 | #endif | |
c5c6a8ab | 1046 | |
30e502a3 DB |
1047 | static inline bool tcp_ca_needs_ecn(const struct sock *sk) |
1048 | { | |
1049 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
1050 | ||
1051 | return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; | |
1052 | } | |
1053 | ||
6687e988 | 1054 | static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state) |
317a76f9 | 1055 | { |
6687e988 ACM |
1056 | struct inet_connection_sock *icsk = inet_csk(sk); |
1057 | ||
1058 | if (icsk->icsk_ca_ops->set_state) | |
1059 | icsk->icsk_ca_ops->set_state(sk, ca_state); | |
1060 | icsk->icsk_ca_state = ca_state; | |
317a76f9 SH |
1061 | } |
1062 | ||
6687e988 | 1063 | static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) |
317a76f9 | 1064 | { |
6687e988 ACM |
1065 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1066 | ||
1067 | if (icsk->icsk_ca_ops->cwnd_event) | |
1068 | icsk->icsk_ca_ops->cwnd_event(sk, event); | |
317a76f9 SH |
1069 | } |
1070 | ||
b9f64820 YC |
1071 | /* From tcp_rate.c */ |
1072 | void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); | |
1073 | void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, | |
1074 | struct rate_sample *rs); | |
1075 | void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, | |
88d5c650 | 1076 | struct rate_sample *rs); |
d7722e85 | 1077 | void tcp_rate_check_app_limited(struct sock *sk); |
b9f64820 | 1078 | |
e60402d0 IJ |
1079 | /* These functions determine how the current flow behaves in respect of SACK |
1080 | * handling. SACK is negotiated with the peer, and therefore it can vary | |
1081 | * between different flows. | |
1082 | * | |
1083 | * tcp_is_sack - SACK enabled | |
1084 | * tcp_is_reno - No SACK | |
1085 | * tcp_is_fack - FACK enabled, implies SACK enabled | |
1086 | */ | |
1087 | static inline int tcp_is_sack(const struct tcp_sock *tp) | |
1088 | { | |
1089 | return tp->rx_opt.sack_ok; | |
1090 | } | |
1091 | ||
a2a385d6 | 1092 | static inline bool tcp_is_reno(const struct tcp_sock *tp) |
e60402d0 IJ |
1093 | { |
1094 | return !tcp_is_sack(tp); | |
1095 | } | |
1096 | ||
a2a385d6 | 1097 | static inline bool tcp_is_fack(const struct tcp_sock *tp) |
e60402d0 | 1098 | { |
ab56222a | 1099 | return tp->rx_opt.sack_ok & TCP_FACK_ENABLED; |
e60402d0 IJ |
1100 | } |
1101 | ||
1102 | static inline void tcp_enable_fack(struct tcp_sock *tp) | |
1103 | { | |
ab56222a | 1104 | tp->rx_opt.sack_ok |= TCP_FACK_ENABLED; |
e60402d0 IJ |
1105 | } |
1106 | ||
83ae4088 IJ |
1107 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
1108 | { | |
1109 | return tp->sacked_out + tp->lost_out; | |
1110 | } | |
1111 | ||
1da177e4 LT |
1112 | /* This determines how many packets are "in the network" to the best |
1113 | * of our knowledge. In many cases it is conservative, but where | |
1114 | * detailed information is available from the receiver (via SACK | |
1115 | * blocks etc.) we can make more aggressive calculations. | |
1116 | * | |
1117 | * Use this for decisions involving congestion control, use just | |
1118 | * tp->packets_out to determine if the send queue is empty or not. | |
1119 | * | |
1120 | * Read this equation as: | |
1121 | * | |
1122 | * "Packets sent once on transmission queue" MINUS | |
1123 | * "Packets left network, but not honestly ACKed yet" PLUS | |
1124 | * "Packets fast retransmitted" | |
1125 | */ | |
40efc6fa | 1126 | static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
1da177e4 | 1127 | { |
83ae4088 | 1128 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
1da177e4 LT |
1129 | } |
1130 | ||
0b6a05c1 IJ |
1131 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
1132 | ||
071d5080 YC |
1133 | static inline bool tcp_in_slow_start(const struct tcp_sock *tp) |
1134 | { | |
76174004 | 1135 | return tp->snd_cwnd < tp->snd_ssthresh; |
071d5080 YC |
1136 | } |
1137 | ||
0b6a05c1 IJ |
1138 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) |
1139 | { | |
1140 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; | |
1141 | } | |
1142 | ||
684bad11 YC |
1143 | static inline bool tcp_in_cwnd_reduction(const struct sock *sk) |
1144 | { | |
1145 | return (TCPF_CA_CWR | TCPF_CA_Recovery) & | |
1146 | (1 << inet_csk(sk)->icsk_ca_state); | |
1147 | } | |
1148 | ||
1da177e4 | 1149 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
684bad11 | 1150 | * The exception is cwnd reduction phase, when cwnd is decreasing towards |
1da177e4 LT |
1151 | * ssthresh. |
1152 | */ | |
6687e988 | 1153 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
1da177e4 | 1154 | { |
6687e988 | 1155 | const struct tcp_sock *tp = tcp_sk(sk); |
cf533ea5 | 1156 | |
684bad11 | 1157 | if (tcp_in_cwnd_reduction(sk)) |
1da177e4 LT |
1158 | return tp->snd_ssthresh; |
1159 | else | |
1160 | return max(tp->snd_ssthresh, | |
1161 | ((tp->snd_cwnd >> 1) + | |
1162 | (tp->snd_cwnd >> 2))); | |
1163 | } | |
1164 | ||
b9c4595b IJ |
1165 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
1166 | #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) | |
1da177e4 | 1167 | |
5ee2c941 | 1168 | void tcp_enter_cwr(struct sock *sk); |
5c9f3023 | 1169 | __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); |
1da177e4 | 1170 | |
6b5a5c0d NC |
1171 | /* The maximum number of MSS of available cwnd for which TSO defers |
1172 | * sending if not using sysctl_tcp_tso_win_divisor. | |
1173 | */ | |
1174 | static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) | |
1175 | { | |
1176 | return 3; | |
1177 | } | |
1178 | ||
90840def IJ |
1179 | /* Returns end sequence number of the receiver's advertised window */ |
1180 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) | |
1181 | { | |
1182 | return tp->snd_una + tp->snd_wnd; | |
1183 | } | |
e114a710 ED |
1184 | |
1185 | /* We follow the spirit of RFC2861 to validate cwnd but implement a more | |
1186 | * flexible approach. The RFC suggests cwnd should not be raised unless | |
ca8a2263 NC |
1187 | * it was fully used previously. And that's exactly what we do in |
1188 | * congestion avoidance mode. But in slow start we allow cwnd to grow | |
1189 | * as long as the application has used half the cwnd. | |
e114a710 ED |
1190 | * Example : |
1191 | * cwnd is 10 (IW10), but application sends 9 frames. | |
1192 | * We allow cwnd to reach 18 when all frames are ACKed. | |
1193 | * This check is safe because it's as aggressive as slow start which already | |
1194 | * risks 100% overshoot. The advantage is that we discourage application to | |
1195 | * either send more filler packets or data to artificially blow up the cwnd | |
1196 | * usage, and allow application-limited process to probe bw more aggressively. | |
e114a710 | 1197 | */ |
24901551 | 1198 | static inline bool tcp_is_cwnd_limited(const struct sock *sk) |
e114a710 ED |
1199 | { |
1200 | const struct tcp_sock *tp = tcp_sk(sk); | |
1201 | ||
ca8a2263 | 1202 | /* If in slow start, ensure cwnd grows to twice what was ACKed. */ |
071d5080 | 1203 | if (tcp_in_slow_start(tp)) |
ca8a2263 NC |
1204 | return tp->snd_cwnd < 2 * tp->max_packets_out; |
1205 | ||
1206 | return tp->is_cwnd_limited; | |
e114a710 | 1207 | } |
f4805ede | 1208 | |
21c8fe99 ED |
1209 | /* Something is really bad, we could not queue an additional packet, |
1210 | * because qdisc is full or receiver sent a 0 window. | |
1211 | * We do not want to add fuel to the fire, or abort too early, | |
1212 | * so make sure the timer we arm now is at least 200ms in the future, | |
1213 | * regardless of current icsk_rto value (as it could be ~2ms) | |
1214 | */ | |
1215 | static inline unsigned long tcp_probe0_base(const struct sock *sk) | |
1da177e4 | 1216 | { |
21c8fe99 ED |
1217 | return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); |
1218 | } | |
9e412ba7 | 1219 | |
21c8fe99 ED |
1220 | /* Variant of inet_csk_rto_backoff() used for zero window probes */ |
1221 | static inline unsigned long tcp_probe0_when(const struct sock *sk, | |
1222 | unsigned long max_when) | |
1223 | { | |
1224 | u64 when = (u64)tcp_probe0_base(sk) << inet_csk(sk)->icsk_backoff; | |
1225 | ||
1226 | return (unsigned long)min_t(u64, when, max_when); | |
1227 | } | |
1228 | ||
1229 | static inline void tcp_check_probe_timer(struct sock *sk) | |
1230 | { | |
1231 | if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) | |
3f421baa | 1232 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
21c8fe99 | 1233 | tcp_probe0_base(sk), TCP_RTO_MAX); |
1da177e4 LT |
1234 | } |
1235 | ||
ee7537b6 | 1236 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
1237 | { |
1238 | tp->snd_wl1 = seq; | |
1239 | } | |
1240 | ||
ee7537b6 | 1241 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
1242 | { |
1243 | tp->snd_wl1 = seq; | |
1244 | } | |
1245 | ||
1da177e4 LT |
1246 | /* |
1247 | * Calculate(/check) TCP checksum | |
1248 | */ | |
ba7808ea FD |
1249 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
1250 | __be32 daddr, __wsum base) | |
1da177e4 LT |
1251 | { |
1252 | return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); | |
1253 | } | |
1254 | ||
b51655b9 | 1255 | static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb) |
1da177e4 | 1256 | { |
fb286bb2 | 1257 | return __skb_checksum_complete(skb); |
1da177e4 LT |
1258 | } |
1259 | ||
a2a385d6 | 1260 | static inline bool tcp_checksum_complete(struct sk_buff *skb) |
1da177e4 | 1261 | { |
60476372 | 1262 | return !skb_csum_unnecessary(skb) && |
1da177e4 LT |
1263 | __tcp_checksum_complete(skb); |
1264 | } | |
1265 | ||
c9c33212 | 1266 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb); |
ac6e7800 | 1267 | int tcp_filter(struct sock *sk, struct sk_buff *skb); |
1da177e4 LT |
1268 | |
1269 | #undef STATE_TRACE | |
1270 | ||
1271 | #ifdef STATE_TRACE | |
1272 | static const char *statename[]={ | |
1273 | "Unused","Established","Syn Sent","Syn Recv", | |
1274 | "Fin Wait 1","Fin Wait 2","Time Wait", "Close", | |
1275 | "Close Wait","Last ACK","Listen","Closing" | |
1276 | }; | |
1277 | #endif | |
5c9f3023 | 1278 | void tcp_set_state(struct sock *sk, int state); |
1da177e4 | 1279 | |
5c9f3023 | 1280 | void tcp_done(struct sock *sk); |
1da177e4 | 1281 | |
c1e64e29 LC |
1282 | int tcp_abort(struct sock *sk, int err); |
1283 | ||
40efc6fa | 1284 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
1da177e4 LT |
1285 | { |
1286 | rx_opt->dsack = 0; | |
1da177e4 LT |
1287 | rx_opt->num_sacks = 0; |
1288 | } | |
1289 | ||
5c9f3023 | 1290 | u32 tcp_default_init_rwnd(u32 mss); |
6f021c62 ED |
1291 | void tcp_cwnd_restart(struct sock *sk, s32 delta); |
1292 | ||
1293 | static inline void tcp_slow_start_after_idle_check(struct sock *sk) | |
1294 | { | |
1b1fc3fd | 1295 | const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; |
6f021c62 ED |
1296 | struct tcp_sock *tp = tcp_sk(sk); |
1297 | s32 delta; | |
1298 | ||
1b1fc3fd WW |
1299 | if (!sysctl_tcp_slow_start_after_idle || tp->packets_out || |
1300 | ca_ops->cong_control) | |
6f021c62 | 1301 | return; |
d635fbe2 | 1302 | delta = tcp_jiffies32 - tp->lsndtime; |
6f021c62 ED |
1303 | if (delta > inet_csk(sk)->icsk_rto) |
1304 | tcp_cwnd_restart(sk, delta); | |
1305 | } | |
85f16525 | 1306 | |
1da177e4 | 1307 | /* Determine a window scaling and initial window to offer. */ |
5c9f3023 JP |
1308 | void tcp_select_initial_window(int __space, __u32 mss, __u32 *rcv_wnd, |
1309 | __u32 *window_clamp, int wscale_ok, | |
1310 | __u8 *rcv_wscale, __u32 init_rcv_wnd); | |
1da177e4 LT |
1311 | |
1312 | static inline int tcp_win_from_space(int space) | |
1313 | { | |
c4836742 GF |
1314 | int tcp_adv_win_scale = sysctl_tcp_adv_win_scale; |
1315 | ||
1316 | return tcp_adv_win_scale <= 0 ? | |
1317 | (space>>(-tcp_adv_win_scale)) : | |
1318 | space - (space>>tcp_adv_win_scale); | |
1da177e4 LT |
1319 | } |
1320 | ||
105970f6 | 1321 | /* Note: caller must be prepared to deal with negative returns */ |
1da177e4 LT |
1322 | static inline int tcp_space(const struct sock *sk) |
1323 | { | |
1324 | return tcp_win_from_space(sk->sk_rcvbuf - | |
1325 | atomic_read(&sk->sk_rmem_alloc)); | |
105970f6 | 1326 | } |
1da177e4 LT |
1327 | |
1328 | static inline int tcp_full_space(const struct sock *sk) | |
1329 | { | |
105970f6 | 1330 | return tcp_win_from_space(sk->sk_rcvbuf); |
1da177e4 LT |
1331 | } |
1332 | ||
843f4a55 | 1333 | extern void tcp_openreq_init_rwin(struct request_sock *req, |
b1964b5f ED |
1334 | const struct sock *sk_listener, |
1335 | const struct dst_entry *dst); | |
843f4a55 | 1336 | |
5c9f3023 | 1337 | void tcp_enter_memory_pressure(struct sock *sk); |
06044751 | 1338 | void tcp_leave_memory_pressure(struct sock *sk); |
1da177e4 | 1339 | |
1da177e4 LT |
1340 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
1341 | { | |
b840d15d NB |
1342 | struct net *net = sock_net((struct sock *)tp); |
1343 | ||
1344 | return tp->keepalive_intvl ? : net->ipv4.sysctl_tcp_keepalive_intvl; | |
1da177e4 LT |
1345 | } |
1346 | ||
1347 | static inline int keepalive_time_when(const struct tcp_sock *tp) | |
1348 | { | |
13b287e8 NB |
1349 | struct net *net = sock_net((struct sock *)tp); |
1350 | ||
1351 | return tp->keepalive_time ? : net->ipv4.sysctl_tcp_keepalive_time; | |
1da177e4 LT |
1352 | } |
1353 | ||
df19a626 ED |
1354 | static inline int keepalive_probes(const struct tcp_sock *tp) |
1355 | { | |
9bd6861b NB |
1356 | struct net *net = sock_net((struct sock *)tp); |
1357 | ||
1358 | return tp->keepalive_probes ? : net->ipv4.sysctl_tcp_keepalive_probes; | |
df19a626 ED |
1359 | } |
1360 | ||
6c37e5de FL |
1361 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
1362 | { | |
1363 | const struct inet_connection_sock *icsk = &tp->inet_conn; | |
1364 | ||
70eabf0e ED |
1365 | return min_t(u32, tcp_jiffies32 - icsk->icsk_ack.lrcvtime, |
1366 | tcp_jiffies32 - tp->rcv_tstamp); | |
6c37e5de FL |
1367 | } |
1368 | ||
463c84b9 | 1369 | static inline int tcp_fin_time(const struct sock *sk) |
1da177e4 | 1370 | { |
1e579caa | 1371 | int fin_timeout = tcp_sk(sk)->linger2 ? : sock_net(sk)->ipv4.sysctl_tcp_fin_timeout; |
463c84b9 | 1372 | const int rto = inet_csk(sk)->icsk_rto; |
1da177e4 | 1373 | |
463c84b9 ACM |
1374 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
1375 | fin_timeout = (rto << 2) - (rto >> 1); | |
1da177e4 LT |
1376 | |
1377 | return fin_timeout; | |
1378 | } | |
1379 | ||
a2a385d6 ED |
1380 | static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, |
1381 | int paws_win) | |
1da177e4 | 1382 | { |
c887e6d2 | 1383 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
a2a385d6 | 1384 | return true; |
c887e6d2 | 1385 | if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)) |
a2a385d6 | 1386 | return true; |
bc2ce894 ED |
1387 | /* |
1388 | * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, | |
1389 | * then following tcp messages have valid values. Ignore 0 value, | |
1390 | * or else 'negative' tsval might forbid us to accept their packets. | |
1391 | */ | |
1392 | if (!rx_opt->ts_recent) | |
a2a385d6 ED |
1393 | return true; |
1394 | return false; | |
c887e6d2 IJ |
1395 | } |
1396 | ||
a2a385d6 ED |
1397 | static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, |
1398 | int rst) | |
c887e6d2 IJ |
1399 | { |
1400 | if (tcp_paws_check(rx_opt, 0)) | |
a2a385d6 | 1401 | return false; |
1da177e4 LT |
1402 | |
1403 | /* RST segments are not recommended to carry timestamp, | |
1404 | and, if they do, it is recommended to ignore PAWS because | |
1405 | "their cleanup function should take precedence over timestamps." | |
1406 | Certainly, it is mistake. It is necessary to understand the reasons | |
1407 | of this constraint to relax it: if peer reboots, clock may go | |
1408 | out-of-sync and half-open connections will not be reset. | |
1409 | Actually, the problem would be not existing if all | |
1410 | the implementations followed draft about maintaining clock | |
1411 | via reboots. Linux-2.2 DOES NOT! | |
1412 | ||
1413 | However, we can relax time bounds for RST segments to MSL. | |
1414 | */ | |
9d729f72 | 1415 | if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) |
a2a385d6 ED |
1416 | return false; |
1417 | return true; | |
1da177e4 LT |
1418 | } |
1419 | ||
7970ddc8 ED |
1420 | bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, |
1421 | int mib_idx, u32 *last_oow_ack_time); | |
032ee423 | 1422 | |
a9c19329 | 1423 | static inline void tcp_mib_init(struct net *net) |
1da177e4 LT |
1424 | { |
1425 | /* See RFC 2012 */ | |
6aef70a8 ED |
1426 | TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); |
1427 | TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); | |
1428 | TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); | |
1429 | TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); | |
1da177e4 LT |
1430 | } |
1431 | ||
5af4ec23 | 1432 | /* from STCP */ |
ef9da47c | 1433 | static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) |
0800f170 | 1434 | { |
6a438bbe | 1435 | tp->lost_skb_hint = NULL; |
ef9da47c IJ |
1436 | } |
1437 | ||
1438 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) | |
1439 | { | |
1440 | tcp_clear_retrans_hints_partial(tp); | |
6a438bbe | 1441 | tp->retransmit_skb_hint = NULL; |
b7689205 IJ |
1442 | } |
1443 | ||
a915da9b ED |
1444 | union tcp_md5_addr { |
1445 | struct in_addr a4; | |
1446 | #if IS_ENABLED(CONFIG_IPV6) | |
1447 | struct in6_addr a6; | |
1448 | #endif | |
1449 | }; | |
1450 | ||
cfb6eeb4 YH |
1451 | /* - key database */ |
1452 | struct tcp_md5sig_key { | |
a915da9b | 1453 | struct hlist_node node; |
cfb6eeb4 | 1454 | u8 keylen; |
a915da9b ED |
1455 | u8 family; /* AF_INET or AF_INET6 */ |
1456 | union tcp_md5_addr addr; | |
6797318e | 1457 | u8 prefixlen; |
a915da9b ED |
1458 | u8 key[TCP_MD5SIG_MAXKEYLEN]; |
1459 | struct rcu_head rcu; | |
cfb6eeb4 YH |
1460 | }; |
1461 | ||
1462 | /* - sock block */ | |
1463 | struct tcp_md5sig_info { | |
a915da9b | 1464 | struct hlist_head head; |
a8afca03 | 1465 | struct rcu_head rcu; |
cfb6eeb4 YH |
1466 | }; |
1467 | ||
1468 | /* - pseudo header */ | |
1469 | struct tcp4_pseudohdr { | |
1470 | __be32 saddr; | |
1471 | __be32 daddr; | |
1472 | __u8 pad; | |
1473 | __u8 protocol; | |
1474 | __be16 len; | |
1475 | }; | |
1476 | ||
1477 | struct tcp6_pseudohdr { | |
1478 | struct in6_addr saddr; | |
1479 | struct in6_addr daddr; | |
1480 | __be32 len; | |
1481 | __be32 protocol; /* including padding */ | |
1482 | }; | |
1483 | ||
1484 | union tcp_md5sum_block { | |
1485 | struct tcp4_pseudohdr ip4; | |
dfd56b8b | 1486 | #if IS_ENABLED(CONFIG_IPV6) |
cfb6eeb4 YH |
1487 | struct tcp6_pseudohdr ip6; |
1488 | #endif | |
1489 | }; | |
1490 | ||
1491 | /* - pool: digest algorithm, hash description and scratch buffer */ | |
1492 | struct tcp_md5sig_pool { | |
cf80e0e4 | 1493 | struct ahash_request *md5_req; |
19689e38 | 1494 | void *scratch; |
cfb6eeb4 YH |
1495 | }; |
1496 | ||
cfb6eeb4 | 1497 | /* - functions */ |
39f8e58e ED |
1498 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
1499 | const struct sock *sk, const struct sk_buff *skb); | |
5c9f3023 | 1500 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
6797318e ID |
1501 | int family, u8 prefixlen, const u8 *newkey, u8 newkeylen, |
1502 | gfp_t gfp); | |
5c9f3023 | 1503 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, |
6797318e | 1504 | int family, u8 prefixlen); |
b83e3deb | 1505 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
fd3a154a | 1506 | const struct sock *addr_sk); |
cfb6eeb4 | 1507 | |
9501f972 | 1508 | #ifdef CONFIG_TCP_MD5SIG |
b83e3deb | 1509 | struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, |
5c9f3023 JP |
1510 | const union tcp_md5_addr *addr, |
1511 | int family); | |
a915da9b | 1512 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) |
9501f972 | 1513 | #else |
b83e3deb | 1514 | static inline struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, |
a915da9b ED |
1515 | const union tcp_md5_addr *addr, |
1516 | int family) | |
1517 | { | |
1518 | return NULL; | |
1519 | } | |
9501f972 YH |
1520 | #define tcp_twsk_md5_key(twsk) NULL |
1521 | #endif | |
1522 | ||
5c9f3023 | 1523 | bool tcp_alloc_md5sig_pool(void); |
cfb6eeb4 | 1524 | |
5c9f3023 | 1525 | struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); |
71cea17e ED |
1526 | static inline void tcp_put_md5sig_pool(void) |
1527 | { | |
1528 | local_bh_enable(); | |
1529 | } | |
35790c04 | 1530 | |
5c9f3023 JP |
1531 | int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *, |
1532 | unsigned int header_len); | |
1533 | int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, | |
1534 | const struct tcp_md5sig_key *key); | |
cfb6eeb4 | 1535 | |
10467163 | 1536 | /* From tcp_fastopen.c */ |
5c9f3023 JP |
1537 | void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
1538 | struct tcp_fastopen_cookie *cookie, int *syn_loss, | |
1539 | unsigned long *last_syn_loss); | |
1540 | void tcp_fastopen_cache_set(struct sock *sk, u16 mss, | |
2646c831 DL |
1541 | struct tcp_fastopen_cookie *cookie, bool syn_lost, |
1542 | u16 try_exp); | |
783237e8 YC |
1543 | struct tcp_fastopen_request { |
1544 | /* Fast Open cookie. Size 0 means a cookie request */ | |
1545 | struct tcp_fastopen_cookie cookie; | |
1546 | struct msghdr *data; /* data in MSG_FASTOPEN */ | |
f5ddcbbb ED |
1547 | size_t size; |
1548 | int copied; /* queued in tcp_connect() */ | |
783237e8 | 1549 | }; |
783237e8 YC |
1550 | void tcp_free_fastopen_req(struct tcp_sock *tp); |
1551 | ||
10467163 JC |
1552 | extern struct tcp_fastopen_context __rcu *tcp_fastopen_ctx; |
1553 | int tcp_fastopen_reset_cipher(void *key, unsigned int len); | |
61d2bcae | 1554 | void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); |
7c85af88 ED |
1555 | struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, |
1556 | struct request_sock *req, | |
11199369 | 1557 | struct tcp_fastopen_cookie *foc); |
dd000598 | 1558 | void tcp_fastopen_init_key_once(void); |
065263f4 WW |
1559 | bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, |
1560 | struct tcp_fastopen_cookie *cookie); | |
19f6d3f3 | 1561 | bool tcp_fastopen_defer_connect(struct sock *sk, int *err); |
10467163 JC |
1562 | #define TCP_FASTOPEN_KEY_LENGTH 16 |
1563 | ||
1564 | /* Fastopen key context */ | |
1565 | struct tcp_fastopen_context { | |
7ae8639c ED |
1566 | struct crypto_cipher *tfm; |
1567 | __u8 key[TCP_FASTOPEN_KEY_LENGTH]; | |
1568 | struct rcu_head rcu; | |
10467163 JC |
1569 | }; |
1570 | ||
cf1ef3f0 | 1571 | extern unsigned int sysctl_tcp_fastopen_blackhole_timeout; |
46c2fa39 | 1572 | void tcp_fastopen_active_disable(struct sock *sk); |
cf1ef3f0 WW |
1573 | bool tcp_fastopen_active_should_disable(struct sock *sk); |
1574 | void tcp_fastopen_active_disable_ofo_check(struct sock *sk); | |
1575 | void tcp_fastopen_active_timeout_reset(void); | |
1576 | ||
05b055e8 FY |
1577 | /* Latencies incurred by various limits for a sender. They are |
1578 | * chronograph-like stats that are mutually exclusive. | |
1579 | */ | |
1580 | enum tcp_chrono { | |
1581 | TCP_CHRONO_UNSPEC, | |
1582 | TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ | |
1583 | TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ | |
1584 | TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ | |
1585 | __TCP_CHRONO_MAX, | |
1586 | }; | |
1587 | ||
1588 | void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); | |
1589 | void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); | |
1590 | ||
fe067e8a DM |
1591 | /* write queue abstraction */ |
1592 | static inline void tcp_write_queue_purge(struct sock *sk) | |
1593 | { | |
1594 | struct sk_buff *skb; | |
1595 | ||
0f87230d | 1596 | tcp_chrono_stop(sk, TCP_CHRONO_BUSY); |
fe067e8a | 1597 | while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) |
3ab224be HA |
1598 | sk_wmem_free_skb(sk, skb); |
1599 | sk_mem_reclaim(sk); | |
8818a9d8 | 1600 | tcp_clear_all_retrans_hints(tcp_sk(sk)); |
fe067e8a DM |
1601 | } |
1602 | ||
cf533ea5 | 1603 | static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) |
fe067e8a | 1604 | { |
cd07a8ea | 1605 | return skb_peek(&sk->sk_write_queue); |
fe067e8a DM |
1606 | } |
1607 | ||
cf533ea5 | 1608 | static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) |
fe067e8a | 1609 | { |
cd07a8ea | 1610 | return skb_peek_tail(&sk->sk_write_queue); |
fe067e8a DM |
1611 | } |
1612 | ||
cf533ea5 ED |
1613 | static inline struct sk_buff *tcp_write_queue_next(const struct sock *sk, |
1614 | const struct sk_buff *skb) | |
fe067e8a | 1615 | { |
cd07a8ea | 1616 | return skb_queue_next(&sk->sk_write_queue, skb); |
fe067e8a DM |
1617 | } |
1618 | ||
cf533ea5 ED |
1619 | static inline struct sk_buff *tcp_write_queue_prev(const struct sock *sk, |
1620 | const struct sk_buff *skb) | |
832d11c5 IJ |
1621 | { |
1622 | return skb_queue_prev(&sk->sk_write_queue, skb); | |
1623 | } | |
1624 | ||
fe067e8a | 1625 | #define tcp_for_write_queue(skb, sk) \ |
cd07a8ea | 1626 | skb_queue_walk(&(sk)->sk_write_queue, skb) |
fe067e8a DM |
1627 | |
1628 | #define tcp_for_write_queue_from(skb, sk) \ | |
cd07a8ea | 1629 | skb_queue_walk_from(&(sk)->sk_write_queue, skb) |
fe067e8a | 1630 | |
234b6860 | 1631 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
cd07a8ea | 1632 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
234b6860 | 1633 | |
cf533ea5 | 1634 | static inline struct sk_buff *tcp_send_head(const struct sock *sk) |
fe067e8a DM |
1635 | { |
1636 | return sk->sk_send_head; | |
1637 | } | |
1638 | ||
cd07a8ea DM |
1639 | static inline bool tcp_skb_is_last(const struct sock *sk, |
1640 | const struct sk_buff *skb) | |
1641 | { | |
1642 | return skb_queue_is_last(&sk->sk_write_queue, skb); | |
1643 | } | |
1644 | ||
cf533ea5 | 1645 | static inline void tcp_advance_send_head(struct sock *sk, const struct sk_buff *skb) |
fe067e8a | 1646 | { |
cd07a8ea | 1647 | if (tcp_skb_is_last(sk, skb)) |
fe067e8a | 1648 | sk->sk_send_head = NULL; |
cd07a8ea DM |
1649 | else |
1650 | sk->sk_send_head = tcp_write_queue_next(sk, skb); | |
fe067e8a DM |
1651 | } |
1652 | ||
1653 | static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked) | |
1654 | { | |
0f87230d | 1655 | if (sk->sk_send_head == skb_unlinked) { |
fe067e8a | 1656 | sk->sk_send_head = NULL; |
0f87230d FY |
1657 | tcp_chrono_stop(sk, TCP_CHRONO_BUSY); |
1658 | } | |
bb1fceca ED |
1659 | if (tcp_sk(sk)->highest_sack == skb_unlinked) |
1660 | tcp_sk(sk)->highest_sack = NULL; | |
fe067e8a DM |
1661 | } |
1662 | ||
1663 | static inline void tcp_init_send_head(struct sock *sk) | |
1664 | { | |
1665 | sk->sk_send_head = NULL; | |
1666 | } | |
1667 | ||
1668 | static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) | |
1669 | { | |
1670 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1671 | } | |
1672 | ||
1673 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) | |
1674 | { | |
1675 | __tcp_add_write_queue_tail(sk, skb); | |
1676 | ||
1677 | /* Queue it, remembering where we must start sending. */ | |
6859d494 | 1678 | if (sk->sk_send_head == NULL) { |
fe067e8a | 1679 | sk->sk_send_head = skb; |
0f87230d | 1680 | tcp_chrono_start(sk, TCP_CHRONO_BUSY); |
6859d494 IJ |
1681 | |
1682 | if (tcp_sk(sk)->highest_sack == NULL) | |
1683 | tcp_sk(sk)->highest_sack = skb; | |
1684 | } | |
fe067e8a DM |
1685 | } |
1686 | ||
1687 | static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb) | |
1688 | { | |
1689 | __skb_queue_head(&sk->sk_write_queue, skb); | |
1690 | } | |
1691 | ||
1692 | /* Insert buff after skb on the write queue of sk. */ | |
1693 | static inline void tcp_insert_write_queue_after(struct sk_buff *skb, | |
1694 | struct sk_buff *buff, | |
1695 | struct sock *sk) | |
1696 | { | |
7de6c033 | 1697 | __skb_queue_after(&sk->sk_write_queue, skb, buff); |
fe067e8a DM |
1698 | } |
1699 | ||
43f59c89 | 1700 | /* Insert new before skb on the write queue of sk. */ |
fe067e8a DM |
1701 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
1702 | struct sk_buff *skb, | |
1703 | struct sock *sk) | |
1704 | { | |
43f59c89 | 1705 | __skb_queue_before(&sk->sk_write_queue, skb, new); |