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> |
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> |
40304b2a LB |
48 | #include <linux/bpf-cgroup.h> |
49 | ||
6e04e021 | 50 | extern struct inet_hashinfo tcp_hashinfo; |
1da177e4 | 51 | |
dd24c001 | 52 | extern struct percpu_counter tcp_orphan_count; |
5c9f3023 | 53 | 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 | 57 | |
105970f6 | 58 | /* |
1da177e4 | 59 | * Never offer a window over 32767 without using window scaling. Some |
105970f6 | 60 | * poor stacks do signed 16bit maths! |
1da177e4 LT |
61 | */ |
62 | #define MAX_TCP_WINDOW 32767U | |
63 | ||
64 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ | |
65 | #define TCP_MIN_MSS 88U | |
66 | ||
5d424d5a | 67 | /* The least MTU to use for probing */ |
dcd8fb85 | 68 | #define TCP_BASE_MSS 1024 |
5d424d5a | 69 | |
05cbc0db FD |
70 | /* probing interval, default to 10 minutes as per RFC4821 */ |
71 | #define TCP_PROBE_INTERVAL 600 | |
72 | ||
6b58e0a5 FD |
73 | /* Specify interval when tcp mtu probing will stop */ |
74 | #define TCP_PROBE_THRESHOLD 8 | |
75 | ||
1da177e4 LT |
76 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
77 | #define TCP_FASTRETRANS_THRESH 3 | |
78 | ||
1da177e4 LT |
79 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
80 | #define TCP_MAX_QUICKACKS 16U | |
81 | ||
589c49cb GF |
82 | /* Maximal number of window scale according to RFC1323 */ |
83 | #define TCP_MAX_WSCALE 14U | |
84 | ||
1da177e4 LT |
85 | /* urg_data states */ |
86 | #define TCP_URG_VALID 0x0100 | |
87 | #define TCP_URG_NOTYET 0x0200 | |
88 | #define TCP_URG_READ 0x0400 | |
89 | ||
90 | #define TCP_RETR1 3 /* | |
91 | * This is how many retries it does before it | |
92 | * tries to figure out if the gateway is | |
93 | * down. Minimal RFC value is 3; it corresponds | |
94 | * to ~3sec-8min depending on RTO. | |
95 | */ | |
96 | ||
97 | #define TCP_RETR2 15 /* | |
98 | * This should take at least | |
99 | * 90 minutes to time out. | |
100 | * RFC1122 says that the limit is 100 sec. | |
101 | * 15 is ~13-30min depending on RTO. | |
102 | */ | |
103 | ||
6c9ff979 AB |
104 | #define TCP_SYN_RETRIES 6 /* This is how many retries are done |
105 | * when active opening a connection. | |
106 | * RFC1122 says the minimum retry MUST | |
107 | * be at least 180secs. Nevertheless | |
108 | * this value is corresponding to | |
109 | * 63secs of retransmission with the | |
110 | * current initial RTO. | |
111 | */ | |
1da177e4 | 112 | |
6c9ff979 AB |
113 | #define TCP_SYNACK_RETRIES 5 /* This is how may retries are done |
114 | * when passive opening a connection. | |
115 | * This is corresponding to 31secs of | |
116 | * retransmission with the current | |
117 | * initial RTO. | |
118 | */ | |
1da177e4 | 119 | |
1da177e4 LT |
120 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
121 | * state, about 60 seconds */ | |
122 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN | |
123 | /* BSD style FIN_WAIT2 deadlock breaker. | |
124 | * It used to be 3min, new value is 60sec, | |
125 | * to combine FIN-WAIT-2 timeout with | |
126 | * TIME-WAIT timer. | |
127 | */ | |
128 | ||
129 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ | |
130 | #if HZ >= 100 | |
131 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ | |
132 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) | |
133 | #else | |
134 | #define TCP_DELACK_MIN 4U | |
135 | #define TCP_ATO_MIN 4U | |
136 | #endif | |
137 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) | |
138 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) | |
bb4d991a | 139 | #define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ |
fd4f2cea | 140 | #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ |
9ad7c049 JC |
141 | #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now |
142 | * used as a fallback RTO for the | |
143 | * initial data transmission if no | |
144 | * valid RTT sample has been acquired, | |
145 | * most likely due to retrans in 3WHS. | |
146 | */ | |
1da177e4 LT |
147 | |
148 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes | |
149 | * for local resources. | |
150 | */ | |
1da177e4 LT |
151 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
152 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ | |
153 | #define TCP_KEEPALIVE_INTVL (75*HZ) | |
154 | ||
155 | #define MAX_TCP_KEEPIDLE 32767 | |
156 | #define MAX_TCP_KEEPINTVL 32767 | |
157 | #define MAX_TCP_KEEPCNT 127 | |
158 | #define MAX_TCP_SYNCNT 127 | |
159 | ||
160 | #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ | |
1da177e4 LT |
161 | |
162 | #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) | |
163 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated | |
164 | * after this time. It should be equal | |
165 | * (or greater than) TCP_TIMEWAIT_LEN | |
166 | * to provide reliability equal to one | |
167 | * provided by timewait state. | |
168 | */ | |
169 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host | |
170 | * timestamps. It must be less than | |
171 | * minimal timewait lifetime. | |
172 | */ | |
1da177e4 LT |
173 | /* |
174 | * TCP option | |
175 | */ | |
105970f6 | 176 | |
1da177e4 LT |
177 | #define TCPOPT_NOP 1 /* Padding */ |
178 | #define TCPOPT_EOL 0 /* End of options */ | |
179 | #define TCPOPT_MSS 2 /* Segment size negotiating */ | |
180 | #define TCPOPT_WINDOW 3 /* Window scaling */ | |
181 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ | |
182 | #define TCPOPT_SACK 5 /* SACK Block */ | |
183 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ | |
cfb6eeb4 | 184 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
7f9b838b | 185 | #define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ |
2100c8d2 YC |
186 | #define TCPOPT_EXP 254 /* Experimental */ |
187 | /* Magic number to be after the option value for sharing TCP | |
188 | * experimental options. See draft-ietf-tcpm-experimental-options-00.txt | |
189 | */ | |
190 | #define TCPOPT_FASTOPEN_MAGIC 0xF989 | |
60e2a778 | 191 | #define TCPOPT_SMC_MAGIC 0xE2D4C3D9 |
1da177e4 LT |
192 | |
193 | /* | |
194 | * TCP option lengths | |
195 | */ | |
196 | ||
197 | #define TCPOLEN_MSS 4 | |
198 | #define TCPOLEN_WINDOW 3 | |
199 | #define TCPOLEN_SACK_PERM 2 | |
200 | #define TCPOLEN_TIMESTAMP 10 | |
cfb6eeb4 | 201 | #define TCPOLEN_MD5SIG 18 |
7f9b838b | 202 | #define TCPOLEN_FASTOPEN_BASE 2 |
2100c8d2 | 203 | #define TCPOLEN_EXP_FASTOPEN_BASE 4 |
60e2a778 | 204 | #define TCPOLEN_EXP_SMC_BASE 6 |
1da177e4 LT |
205 | |
206 | /* But this is what stacks really send out. */ | |
207 | #define TCPOLEN_TSTAMP_ALIGNED 12 | |
208 | #define TCPOLEN_WSCALE_ALIGNED 4 | |
209 | #define TCPOLEN_SACKPERM_ALIGNED 4 | |
210 | #define TCPOLEN_SACK_BASE 2 | |
211 | #define TCPOLEN_SACK_BASE_ALIGNED 4 | |
212 | #define TCPOLEN_SACK_PERBLOCK 8 | |
cfb6eeb4 | 213 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
33ad798c | 214 | #define TCPOLEN_MSS_ALIGNED 4 |
60e2a778 | 215 | #define TCPOLEN_EXP_SMC_BASE_ALIGNED 8 |
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 | 243 | extern int sysctl_tcp_max_orphans; |
a4fe34bf | 244 | extern long sysctl_tcp_mem[3]; |
e20223f1 | 245 | |
a0370b3f | 246 | #define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ |
1f255691 | 247 | #define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */ |
20b654df | 248 | #define TCP_RACK_NO_DUPTHRESH 0x4 /* Do not use DUPACK threshold in RACK */ |
a0370b3f | 249 | |
8d987e5c | 250 | extern atomic_long_t tcp_memory_allocated; |
1748376b | 251 | extern struct percpu_counter tcp_sockets_allocated; |
06044751 | 252 | extern unsigned long tcp_memory_pressure; |
1da177e4 | 253 | |
b8da51eb ED |
254 | /* optimized version of sk_under_memory_pressure() for TCP sockets */ |
255 | static inline bool tcp_under_memory_pressure(const struct sock *sk) | |
256 | { | |
baac50bb JW |
257 | if (mem_cgroup_sockets_enabled && sk->sk_memcg && |
258 | mem_cgroup_under_socket_pressure(sk->sk_memcg)) | |
e805605c | 259 | return true; |
b8da51eb ED |
260 | |
261 | return tcp_memory_pressure; | |
262 | } | |
1da177e4 LT |
263 | /* |
264 | * The next routines deal with comparing 32 bit unsigned ints | |
265 | * and worry about wraparound (automatic with unsigned arithmetic). | |
266 | */ | |
267 | ||
a2a385d6 | 268 | static inline bool before(__u32 seq1, __u32 seq2) |
1da177e4 | 269 | { |
0d630cc0 | 270 | return (__s32)(seq1-seq2) < 0; |
1da177e4 | 271 | } |
9a036b9c | 272 | #define after(seq2, seq1) before(seq1, seq2) |
1da177e4 LT |
273 | |
274 | /* is s2<=s1<=s3 ? */ | |
a2a385d6 | 275 | static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) |
1da177e4 LT |
276 | { |
277 | return seq3 - seq2 >= seq1 - seq2; | |
278 | } | |
279 | ||
efcdbf24 AS |
280 | static inline bool tcp_out_of_memory(struct sock *sk) |
281 | { | |
282 | if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && | |
283 | sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2)) | |
284 | return true; | |
285 | return false; | |
286 | } | |
287 | ||
a6c5ea4c ED |
288 | void sk_forced_mem_schedule(struct sock *sk, int size); |
289 | ||
ad1af0fe | 290 | static inline bool tcp_too_many_orphans(struct sock *sk, int shift) |
e4fd5da3 | 291 | { |
ad1af0fe DM |
292 | struct percpu_counter *ocp = sk->sk_prot->orphan_count; |
293 | int orphans = percpu_counter_read_positive(ocp); | |
294 | ||
295 | if (orphans << shift > sysctl_tcp_max_orphans) { | |
296 | orphans = percpu_counter_sum_positive(ocp); | |
297 | if (orphans << shift > sysctl_tcp_max_orphans) | |
298 | return true; | |
299 | } | |
ad1af0fe | 300 | return false; |
e4fd5da3 | 301 | } |
1da177e4 | 302 | |
5c9f3023 | 303 | bool tcp_check_oom(struct sock *sk, int shift); |
efcdbf24 | 304 | |
a0f82f64 | 305 | |
1da177e4 LT |
306 | extern struct proto tcp_prot; |
307 | ||
57ef42d5 | 308 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
13415e46 | 309 | #define __TCP_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
57ef42d5 | 310 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) |
aa2ea058 | 311 | #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) |
1da177e4 | 312 | |
5c9f3023 JP |
313 | void tcp_tasklet_init(void); |
314 | ||
315 | void tcp_v4_err(struct sk_buff *skb, u32); | |
316 | ||
317 | void tcp_shutdown(struct sock *sk, int how); | |
318 | ||
7487449c | 319 | int tcp_v4_early_demux(struct sk_buff *skb); |
5c9f3023 JP |
320 | int tcp_v4_rcv(struct sk_buff *skb); |
321 | ||
322 | int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); | |
1b784140 | 323 | int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); |
306b13eb | 324 | int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size); |
5c9f3023 JP |
325 | int tcp_sendpage(struct sock *sk, struct page *page, int offset, size_t size, |
326 | int flags); | |
306b13eb TH |
327 | int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset, |
328 | size_t size, int flags); | |
e3b5616a DW |
329 | ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, |
330 | size_t size, int flags); | |
5c9f3023 JP |
331 | void tcp_release_cb(struct sock *sk); |
332 | void tcp_wfree(struct sk_buff *skb); | |
333 | void tcp_write_timer_handler(struct sock *sk); | |
334 | void tcp_delack_timer_handler(struct sock *sk); | |
335 | int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg); | |
72ab4a86 | 336 | int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); |
3d97d88e | 337 | void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); |
5c9f3023 | 338 | void tcp_rcv_space_adjust(struct sock *sk); |
5c9f3023 JP |
339 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); |
340 | void tcp_twsk_destructor(struct sock *sk); | |
341 | ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, | |
342 | struct pipe_inode_info *pipe, size_t len, | |
343 | unsigned int flags); | |
9c55e01c | 344 | |
463c84b9 ACM |
345 | static inline void tcp_dec_quickack_mode(struct sock *sk, |
346 | const unsigned int pkts) | |
1da177e4 | 347 | { |
463c84b9 | 348 | struct inet_connection_sock *icsk = inet_csk(sk); |
fc6415bc | 349 | |
463c84b9 ACM |
350 | if (icsk->icsk_ack.quick) { |
351 | if (pkts >= icsk->icsk_ack.quick) { | |
352 | icsk->icsk_ack.quick = 0; | |
fc6415bc | 353 | /* Leaving quickack mode we deflate ATO. */ |
463c84b9 | 354 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
fc6415bc | 355 | } else |
463c84b9 | 356 | icsk->icsk_ack.quick -= pkts; |
1da177e4 LT |
357 | } |
358 | } | |
359 | ||
bdf1ee5d IJ |
360 | #define TCP_ECN_OK 1 |
361 | #define TCP_ECN_QUEUE_CWR 2 | |
362 | #define TCP_ECN_DEMAND_CWR 4 | |
7a269ffa | 363 | #define TCP_ECN_SEEN 8 |
bdf1ee5d | 364 | |
fd2c3ef7 | 365 | enum tcp_tw_status { |
1da177e4 LT |
366 | TCP_TW_SUCCESS = 0, |
367 | TCP_TW_RST = 1, | |
368 | TCP_TW_ACK = 2, | |
369 | TCP_TW_SYN = 3 | |
370 | }; | |
371 | ||
372 | ||
5c9f3023 JP |
373 | enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
374 | struct sk_buff *skb, | |
375 | const struct tcphdr *th); | |
376 | struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, | |
e0f9759f ED |
377 | struct request_sock *req, bool fastopen, |
378 | bool *lost_race); | |
5c9f3023 JP |
379 | int tcp_child_process(struct sock *parent, struct sock *child, |
380 | struct sk_buff *skb); | |
5ae344c9 | 381 | void tcp_enter_loss(struct sock *sk); |
57dde7f7 | 382 | void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int flag); |
5c9f3023 JP |
383 | void tcp_clear_retrans(struct tcp_sock *tp); |
384 | void tcp_update_metrics(struct sock *sk); | |
385 | void tcp_init_metrics(struct sock *sk); | |
386 | void tcp_metrics_init(void); | |
d82bae12 | 387 | bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst); |
5c9f3023 JP |
388 | void tcp_close(struct sock *sk, long timeout); |
389 | void tcp_init_sock(struct sock *sk); | |
27204aaa | 390 | void tcp_init_transfer(struct sock *sk, int bpf_op); |
a11e1d43 LT |
391 | __poll_t tcp_poll(struct file *file, struct socket *sock, |
392 | struct poll_table_struct *wait); | |
5c9f3023 JP |
393 | int tcp_getsockopt(struct sock *sk, int level, int optname, |
394 | char __user *optval, int __user *optlen); | |
395 | int tcp_setsockopt(struct sock *sk, int level, int optname, | |
396 | char __user *optval, unsigned int optlen); | |
397 | int compat_tcp_getsockopt(struct sock *sk, int level, int optname, | |
53d3176b | 398 | char __user *optval, int __user *optlen); |
5c9f3023 | 399 | int compat_tcp_setsockopt(struct sock *sk, int level, int optname, |
53d3176b | 400 | char __user *optval, unsigned int optlen); |
5c9f3023 | 401 | void tcp_set_keepalive(struct sock *sk, int val); |
42cb80a2 | 402 | void tcp_syn_ack_timeout(const struct request_sock *req); |
1b784140 YX |
403 | int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, |
404 | int flags, int *addr_len); | |
d1361840 | 405 | int tcp_set_rcvlowat(struct sock *sk, int val); |
03f45c88 | 406 | void tcp_data_ready(struct sock *sk); |
93ab6cc6 ED |
407 | int tcp_mmap(struct file *file, struct socket *sock, |
408 | struct vm_area_struct *vma); | |
eed29f17 | 409 | void tcp_parse_options(const struct net *net, const struct sk_buff *skb, |
5c9f3023 JP |
410 | struct tcp_options_received *opt_rx, |
411 | int estab, struct tcp_fastopen_cookie *foc); | |
412 | const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); | |
7d5d5525 | 413 | |
1da177e4 LT |
414 | /* |
415 | * TCP v4 functions exported for the inet6 API | |
416 | */ | |
417 | ||
5c9f3023 | 418 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
4fab9071 | 419 | void tcp_v4_mtu_reduced(struct sock *sk); |
9cf74903 | 420 | void tcp_req_err(struct sock *sk, u32 seq, bool abort); |
5c9f3023 | 421 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); |
c28c6f04 | 422 | struct sock *tcp_create_openreq_child(const struct sock *sk, |
5c9f3023 JP |
423 | struct request_sock *req, |
424 | struct sk_buff *skb); | |
81164413 | 425 | void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); |
0c27171e | 426 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
5c9f3023 | 427 | struct request_sock *req, |
5e0724d0 ED |
428 | struct dst_entry *dst, |
429 | struct request_sock *req_unhash, | |
430 | bool *own_req); | |
5c9f3023 JP |
431 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); |
432 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); | |
433 | int tcp_connect(struct sock *sk); | |
b3d05147 ED |
434 | enum tcp_synack_type { |
435 | TCP_SYNACK_NORMAL, | |
436 | TCP_SYNACK_FASTOPEN, | |
437 | TCP_SYNACK_COOKIE, | |
438 | }; | |
5d062de7 | 439 | struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, |
5c9f3023 | 440 | struct request_sock *req, |
ca6fb065 | 441 | struct tcp_fastopen_cookie *foc, |
b3d05147 | 442 | enum tcp_synack_type synack_type); |
5c9f3023 | 443 | int tcp_disconnect(struct sock *sk, int flags); |
1da177e4 | 444 | |
370816ae | 445 | void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); |
292e8d8c | 446 | int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); |
63d02d15 | 447 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); |
1da177e4 | 448 | |
1da177e4 | 449 | /* From syncookies.c */ |
b80c0e78 ED |
450 | struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, |
451 | struct request_sock *req, | |
84b114b9 | 452 | struct dst_entry *dst, u32 tsoff); |
5c9f3023 JP |
453 | int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, |
454 | u32 cookie); | |
461b74c3 | 455 | struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); |
e05c82d3 | 456 | #ifdef CONFIG_SYN_COOKIES |
8c27bd75 | 457 | |
63262315 | 458 | /* Syncookies use a monotonic timer which increments every 60 seconds. |
8c27bd75 FW |
459 | * This counter is used both as a hash input and partially encoded into |
460 | * the cookie value. A cookie is only validated further if the delta | |
461 | * between the current counter value and the encoded one is less than this, | |
63262315 | 462 | * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if |
8c27bd75 FW |
463 | * the counter advances immediately after a cookie is generated). |
464 | */ | |
264ea103 ED |
465 | #define MAX_SYNCOOKIE_AGE 2 |
466 | #define TCP_SYNCOOKIE_PERIOD (60 * HZ) | |
467 | #define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) | |
468 | ||
469 | /* syncookies: remember time of last synqueue overflow | |
470 | * But do not dirty this field too often (once per second is enough) | |
3f684b4b | 471 | * It is racy as we do not hold a lock, but race is very minor. |
264ea103 | 472 | */ |
3f684b4b | 473 | static inline void tcp_synq_overflow(const struct sock *sk) |
264ea103 ED |
474 | { |
475 | unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; | |
476 | unsigned long now = jiffies; | |
477 | ||
478 | if (time_after(now, last_overflow + HZ)) | |
479 | tcp_sk(sk)->rx_opt.ts_recent_stamp = now; | |
480 | } | |
481 | ||
482 | /* syncookies: no recent synqueue overflow on this listening socket? */ | |
483 | static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) | |
484 | { | |
485 | unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; | |
486 | ||
487 | return time_after(jiffies, last_overflow + TCP_SYNCOOKIE_VALID); | |
488 | } | |
8c27bd75 FW |
489 | |
490 | static inline u32 tcp_cookie_time(void) | |
491 | { | |
63262315 ED |
492 | u64 val = get_jiffies_64(); |
493 | ||
264ea103 | 494 | do_div(val, TCP_SYNCOOKIE_PERIOD); |
63262315 | 495 | return val; |
8c27bd75 FW |
496 | } |
497 | ||
5c9f3023 JP |
498 | u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, |
499 | u16 *mssp); | |
3f684b4b | 500 | __u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); |
9a568de4 | 501 | u64 cookie_init_timestamp(struct request_sock *req); |
f9301034 ED |
502 | bool cookie_timestamp_decode(const struct net *net, |
503 | struct tcp_options_received *opt); | |
f1673381 | 504 | bool cookie_ecn_ok(const struct tcp_options_received *opt, |
f7b3bec6 | 505 | const struct net *net, const struct dst_entry *dst); |
4dfc2817 | 506 | |
c6aefafb | 507 | /* From net/ipv6/syncookies.c */ |
5c9f3023 JP |
508 | int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, |
509 | u32 cookie); | |
510 | struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); | |
f1673381 | 511 | |
5c9f3023 JP |
512 | u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, |
513 | const struct tcphdr *th, u16 *mssp); | |
3f684b4b | 514 | __u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); |
e05c82d3 | 515 | #endif |
1da177e4 LT |
516 | /* tcp_output.c */ |
517 | ||
5c9f3023 JP |
518 | void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
519 | int nonagle); | |
10d3be56 ED |
520 | int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
521 | int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); | |
5c9f3023 JP |
522 | void tcp_retransmit_timer(struct sock *sk); |
523 | void tcp_xmit_retransmit_queue(struct sock *); | |
524 | void tcp_simple_retransmit(struct sock *); | |
57dde7f7 | 525 | void tcp_enter_recovery(struct sock *sk, bool ece_ack); |
5c9f3023 | 526 | int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
75c119af ED |
527 | enum tcp_queue { |
528 | TCP_FRAG_IN_WRITE_QUEUE, | |
529 | TCP_FRAG_IN_RTX_QUEUE, | |
530 | }; | |
531 | int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, | |
532 | struct sk_buff *skb, u32 len, | |
533 | unsigned int mss_now, gfp_t gfp); | |
5c9f3023 JP |
534 | |
535 | void tcp_send_probe0(struct sock *); | |
536 | void tcp_send_partial(struct sock *); | |
e520af48 | 537 | int tcp_write_wakeup(struct sock *, int mib); |
5c9f3023 JP |
538 | void tcp_send_fin(struct sock *sk); |
539 | void tcp_send_active_reset(struct sock *sk, gfp_t priority); | |
540 | int tcp_send_synack(struct sock *); | |
5c9f3023 JP |
541 | void tcp_push_one(struct sock *, unsigned int mss_now); |
542 | void tcp_send_ack(struct sock *sk); | |
543 | void tcp_send_delayed_ack(struct sock *sk); | |
544 | void tcp_send_loss_probe(struct sock *sk); | |
ed66dfaf | 545 | bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto); |
cfea5a68 MKL |
546 | void tcp_skb_collapse_tstamp(struct sk_buff *skb, |
547 | const struct sk_buff *next_skb); | |
1da177e4 | 548 | |
a762a980 | 549 | /* tcp_input.c */ |
5c9f3023 | 550 | void tcp_rearm_rto(struct sock *sk); |
0f1c28ae | 551 | void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); |
5c9f3023 | 552 | void tcp_reset(struct sock *sk); |
4f41b1c5 | 553 | void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb); |
e3e17b77 | 554 | void tcp_fin(struct sock *sk); |
a762a980 | 555 | |
1da177e4 | 556 | /* tcp_timer.c */ |
5c9f3023 | 557 | void tcp_init_xmit_timers(struct sock *); |
463c84b9 ACM |
558 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
559 | { | |
73a6bab5 | 560 | if (hrtimer_try_to_cancel(&tcp_sk(sk)->pacing_timer) == 1) |
cf0dd203 | 561 | __sock_put(sk); |
73a6bab5 | 562 | |
5d9f4262 ED |
563 | if (hrtimer_try_to_cancel(&tcp_sk(sk)->compressed_ack_timer) == 1) |
564 | __sock_put(sk); | |
565 | ||
463c84b9 ACM |
566 | inet_csk_clear_xmit_timers(sk); |
567 | } | |
1da177e4 | 568 | |
5c9f3023 JP |
569 | unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
570 | unsigned int tcp_current_mss(struct sock *sk); | |
0c54b85f IJ |
571 | |
572 | /* Bound MSS / TSO packet size with the half of the window */ | |
573 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) | |
574 | { | |
01f83d69 AK |
575 | int cutoff; |
576 | ||
577 | /* When peer uses tiny windows, there is no use in packetizing | |
578 | * to sub-MSS pieces for the sake of SWS or making sure there | |
579 | * are enough packets in the pipe for fast recovery. | |
580 | * | |
581 | * On the other hand, for extremely large MSS devices, handling | |
582 | * smaller than MSS windows in this way does make sense. | |
583 | */ | |
2631b79f | 584 | if (tp->max_window > TCP_MSS_DEFAULT) |
01f83d69 AK |
585 | cutoff = (tp->max_window >> 1); |
586 | else | |
587 | cutoff = tp->max_window; | |
588 | ||
589 | if (cutoff && pktsize > cutoff) | |
590 | return max_t(int, cutoff, 68U - tp->tcp_header_len); | |
0c54b85f IJ |
591 | else |
592 | return pktsize; | |
593 | } | |
1da177e4 | 594 | |
17b085ea | 595 | /* tcp.c */ |
0df48c26 | 596 | void tcp_get_info(struct sock *, struct tcp_info *); |
1da177e4 LT |
597 | |
598 | /* Read 'sendfile()'-style from a TCP socket */ | |
5c9f3023 JP |
599 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
600 | sk_read_actor_t recv_actor); | |
1da177e4 | 601 | |
5c9f3023 | 602 | void tcp_initialize_rcv_mss(struct sock *sk); |
1da177e4 | 603 | |
5c9f3023 JP |
604 | int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
605 | int tcp_mss_to_mtu(struct sock *sk, int mss); | |
606 | void tcp_mtup_init(struct sock *sk); | |
607 | void tcp_init_buffer_space(struct sock *sk); | |
5d424d5a | 608 | |
f1ecd5d9 DL |
609 | static inline void tcp_bound_rto(const struct sock *sk) |
610 | { | |
611 | if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) | |
612 | inet_csk(sk)->icsk_rto = TCP_RTO_MAX; | |
613 | } | |
614 | ||
615 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) | |
616 | { | |
740b0f18 | 617 | return usecs_to_jiffies((tp->srtt_us >> 3) + tp->rttvar_us); |
f1ecd5d9 DL |
618 | } |
619 | ||
31770e34 FW |
620 | static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
621 | { | |
622 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | | |
623 | ntohl(TCP_FLAG_ACK) | | |
624 | snd_wnd); | |
625 | } | |
626 | ||
627 | static inline void tcp_fast_path_on(struct tcp_sock *tp) | |
628 | { | |
629 | __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); | |
630 | } | |
631 | ||
632 | static inline void tcp_fast_path_check(struct sock *sk) | |
633 | { | |
634 | struct tcp_sock *tp = tcp_sk(sk); | |
635 | ||
636 | if (RB_EMPTY_ROOT(&tp->out_of_order_queue) && | |
637 | tp->rcv_wnd && | |
638 | atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && | |
639 | !tp->urg_data) | |
640 | tcp_fast_path_on(tp); | |
641 | } | |
642 | ||
0c266898 SS |
643 | /* Compute the actual rto_min value */ |
644 | static inline u32 tcp_rto_min(struct sock *sk) | |
645 | { | |
cf533ea5 | 646 | const struct dst_entry *dst = __sk_dst_get(sk); |
0c266898 SS |
647 | u32 rto_min = TCP_RTO_MIN; |
648 | ||
649 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) | |
650 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); | |
651 | return rto_min; | |
652 | } | |
653 | ||
740b0f18 ED |
654 | static inline u32 tcp_rto_min_us(struct sock *sk) |
655 | { | |
656 | return jiffies_to_usecs(tcp_rto_min(sk)); | |
657 | } | |
658 | ||
81164413 DB |
659 | static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) |
660 | { | |
661 | return dst_metric_locked(dst, RTAX_CC_ALGO); | |
662 | } | |
663 | ||
f6722583 YC |
664 | /* Minimum RTT in usec. ~0 means not available. */ |
665 | static inline u32 tcp_min_rtt(const struct tcp_sock *tp) | |
666 | { | |
64033892 | 667 | return minmax_get(&tp->rtt_min); |
f6722583 YC |
668 | } |
669 | ||
1da177e4 LT |
670 | /* Compute the actual receive window we are currently advertising. |
671 | * Rcv_nxt can be after the window if our peer push more data | |
672 | * than the offered window. | |
673 | */ | |
40efc6fa | 674 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
1da177e4 LT |
675 | { |
676 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; | |
677 | ||
678 | if (win < 0) | |
679 | win = 0; | |
680 | return (u32) win; | |
681 | } | |
682 | ||
683 | /* Choose a new window, without checks for shrinking, and without | |
684 | * scaling applied to the result. The caller does these things | |
685 | * if necessary. This is a "raw" window selection. | |
686 | */ | |
5c9f3023 | 687 | u32 __tcp_select_window(struct sock *sk); |
1da177e4 | 688 | |
ee995283 PE |
689 | void tcp_send_window_probe(struct sock *sk); |
690 | ||
ec66eda8 ED |
691 | /* TCP uses 32bit jiffies to save some space. |
692 | * Note that this is different from tcp_time_stamp, which | |
693 | * historically has been the same until linux-4.13. | |
694 | */ | |
695 | #define tcp_jiffies32 ((u32)jiffies) | |
696 | ||
9a568de4 ED |
697 | /* |
698 | * Deliver a 32bit value for TCP timestamp option (RFC 7323) | |
699 | * It is no longer tied to jiffies, but to 1 ms clock. | |
700 | * Note: double check if you want to use tcp_jiffies32 instead of this. | |
701 | */ | |
702 | #define TCP_TS_HZ 1000 | |
703 | ||
704 | static inline u64 tcp_clock_ns(void) | |
705 | { | |
706 | return local_clock(); | |
707 | } | |
708 | ||
709 | static inline u64 tcp_clock_us(void) | |
710 | { | |
711 | return div_u64(tcp_clock_ns(), NSEC_PER_USEC); | |
712 | } | |
713 | ||
714 | /* This should only be used in contexts where tp->tcp_mstamp is up to date */ | |
715 | static inline u32 tcp_time_stamp(const struct tcp_sock *tp) | |
716 | { | |
717 | return div_u64(tp->tcp_mstamp, USEC_PER_SEC / TCP_TS_HZ); | |
718 | } | |
719 | ||
720 | /* Could use tcp_clock_us() / 1000, but this version uses a single divide */ | |
721 | static inline u32 tcp_time_stamp_raw(void) | |
722 | { | |
723 | return div_u64(tcp_clock_ns(), NSEC_PER_SEC / TCP_TS_HZ); | |
724 | } | |
725 | ||
726 | ||
727 | /* Refresh 1us clock of a TCP socket, | |
728 | * ensuring monotically increasing values. | |
1da177e4 | 729 | */ |
9a568de4 ED |
730 | static inline void tcp_mstamp_refresh(struct tcp_sock *tp) |
731 | { | |
732 | u64 val = tcp_clock_us(); | |
733 | ||
734 | if (val > tp->tcp_mstamp) | |
735 | tp->tcp_mstamp = val; | |
736 | } | |
737 | ||
738 | static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) | |
739 | { | |
740 | return max_t(s64, t1 - t0, 0); | |
741 | } | |
1da177e4 | 742 | |
7faee5c0 ED |
743 | static inline u32 tcp_skb_timestamp(const struct sk_buff *skb) |
744 | { | |
9a568de4 | 745 | return div_u64(skb->skb_mstamp, USEC_PER_SEC / TCP_TS_HZ); |
7faee5c0 ED |
746 | } |
747 | ||
748 | ||
a3433f35 CG |
749 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
750 | ||
751 | #define TCPHDR_FIN 0x01 | |
752 | #define TCPHDR_SYN 0x02 | |
753 | #define TCPHDR_RST 0x04 | |
754 | #define TCPHDR_PSH 0x08 | |
755 | #define TCPHDR_ACK 0x10 | |
756 | #define TCPHDR_URG 0x20 | |
757 | #define TCPHDR_ECE 0x40 | |
758 | #define TCPHDR_CWR 0x80 | |
759 | ||
49213555 DB |
760 | #define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) |
761 | ||
caa20d9a | 762 | /* This is what the send packet queuing engine uses to pass |
f86586fa ED |
763 | * TCP per-packet control information to the transmission code. |
764 | * We also store the host-order sequence numbers in here too. | |
765 | * This is 44 bytes if IPV6 is enabled. | |
766 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. | |
1da177e4 LT |
767 | */ |
768 | struct tcp_skb_cb { | |
1da177e4 LT |
769 | __u32 seq; /* Starting sequence number */ |
770 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ | |
cd7d8498 ED |
771 | union { |
772 | /* Note : tcp_tw_isn is used in input path only | |
773 | * (isn chosen by tcp_timewait_state_process()) | |
774 | * | |
f69ad292 ED |
775 | * tcp_gso_segs/size are used in write queue only, |
776 | * cf tcp_skb_pcount()/tcp_skb_mss() | |
cd7d8498 ED |
777 | */ |
778 | __u32 tcp_tw_isn; | |
f69ad292 ED |
779 | struct { |
780 | u16 tcp_gso_segs; | |
781 | u16 tcp_gso_size; | |
782 | }; | |
cd7d8498 | 783 | }; |
4de075e0 | 784 | __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ |
f4f9f6e7 | 785 | |
713bafea | 786 | __u8 sacked; /* State flags for SACK. */ |
1da177e4 LT |
787 | #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ |
788 | #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ | |
789 | #define TCPCB_LOST 0x04 /* SKB is lost */ | |
790 | #define TCPCB_TAGBITS 0x07 /* All tag bits */ | |
9d186cac | 791 | #define TCPCB_REPAIRED 0x10 /* SKB repaired (no skb_mstamp) */ |
1da177e4 | 792 | #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ |
9d186cac AV |
793 | #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS| \ |
794 | TCPCB_REPAIRED) | |
1da177e4 | 795 | |
f4f9f6e7 | 796 | __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ |
6b084928 | 797 | __u8 txstamp_ack:1, /* Record TX timestamp for ack? */ |
c134ecb8 | 798 | eor:1, /* Is skb MSG_EOR marked? */ |
98aaa913 MM |
799 | has_rxtstamp:1, /* SKB has a RX timestamp */ |
800 | unused:5; | |
1da177e4 | 801 | __u32 ack_seq; /* Sequence number ACK'd */ |
971f10ec | 802 | union { |
b75803d5 | 803 | struct { |
b9f64820 | 804 | /* There is space for up to 24 bytes */ |
d7722e85 SHY |
805 | __u32 in_flight:30,/* Bytes in flight at transmit */ |
806 | is_app_limited:1, /* cwnd not fully used? */ | |
807 | unused:1; | |
b9f64820 YC |
808 | /* pkts S/ACKed so far upon tx of skb, incl retrans: */ |
809 | __u32 delivered; | |
810 | /* start of send pipeline phase */ | |
9a568de4 | 811 | u64 first_tx_mstamp; |
b9f64820 | 812 | /* when we reached the "delivered" count */ |
9a568de4 | 813 | u64 delivered_mstamp; |
b75803d5 LB |
814 | } tx; /* only used for outgoing skbs */ |
815 | union { | |
816 | struct inet_skb_parm h4; | |
971f10ec | 817 | #if IS_ENABLED(CONFIG_IPV6) |
b75803d5 | 818 | struct inet6_skb_parm h6; |
971f10ec | 819 | #endif |
b75803d5 | 820 | } header; /* For incoming skbs */ |
34f79502 | 821 | struct { |
34f79502 | 822 | __u32 flags; |
e5cd3abc | 823 | struct sock *sk_redir; |
8108a775 | 824 | void *data_end; |
34f79502 | 825 | } bpf; |
b75803d5 | 826 | }; |
1da177e4 LT |
827 | }; |
828 | ||
829 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) | |
830 | ||
870c3151 | 831 | |
815afe17 | 832 | #if IS_ENABLED(CONFIG_IPV6) |
870c3151 ED |
833 | /* This is the variant of inet6_iif() that must be used by TCP, |
834 | * as TCP moves IP6CB into a different location in skb->cb[] | |
835 | */ | |
836 | static inline int tcp_v6_iif(const struct sk_buff *skb) | |
837 | { | |
a04a480d | 838 | bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); |
74b20582 DA |
839 | |
840 | return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; | |
870c3151 | 841 | } |
4297a0ef DA |
842 | |
843 | /* TCP_SKB_CB reference means this can not be used from early demux */ | |
844 | static inline int tcp_v6_sdif(const struct sk_buff *skb) | |
845 | { | |
846 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) | |
847 | if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags)) | |
848 | return TCP_SKB_CB(skb)->header.h6.iif; | |
849 | #endif | |
850 | return 0; | |
851 | } | |
815afe17 | 852 | #endif |
870c3151 | 853 | |
a04a480d DA |
854 | static inline bool inet_exact_dif_match(struct net *net, struct sk_buff *skb) |
855 | { | |
856 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) | |
857 | if (!net->ipv4.sysctl_tcp_l3mdev_accept && | |
b4d1605a | 858 | skb && ipv4_l3mdev_skb(IPCB(skb)->flags)) |
a04a480d DA |
859 | return true; |
860 | #endif | |
861 | return false; | |
862 | } | |
863 | ||
3fa6f616 DA |
864 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
865 | static inline int tcp_v4_sdif(struct sk_buff *skb) | |
866 | { | |
867 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) | |
868 | if (skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) | |
869 | return TCP_SKB_CB(skb)->header.h4.iif; | |
870 | #endif | |
871 | return 0; | |
872 | } | |
873 | ||
1da177e4 LT |
874 | /* Due to TSO, an SKB can be composed of multiple actual |
875 | * packets. To keep these tracked properly, we use this. | |
bd14b1b2 | 876 | */ |
1da177e4 | 877 | static inline int tcp_skb_pcount(const struct sk_buff *skb) |
bd14b1b2 | 878 | { |
cd7d8498 ED |
879 | return TCP_SKB_CB(skb)->tcp_gso_segs; |
880 | } | |
bd14b1b2 | 881 | |
cd7d8498 ED |
882 | static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) |
883 | { | |
884 | TCP_SKB_CB(skb)->tcp_gso_segs = segs; | |
bd14b1b2 ED |
885 | } |
886 | ||
cd7d8498 | 887 | static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) |
1da177e4 | 888 | { |
cd7d8498 | 889 | TCP_SKB_CB(skb)->tcp_gso_segs += segs; |
1da177e4 LT |
890 | } |
891 | ||
f69ad292 | 892 | /* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ |
1da177e4 LT |
893 | static inline int tcp_skb_mss(const struct sk_buff *skb) |
894 | { | |
f69ad292 | 895 | return TCP_SKB_CB(skb)->tcp_gso_size; |
1da177e4 LT |
896 | } |
897 | ||
c134ecb8 MKL |
898 | static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) |
899 | { | |
900 | return likely(!TCP_SKB_CB(skb)->eor); | |
901 | } | |
902 | ||
317a76f9 SH |
903 | /* Events passed to congestion control interface */ |
904 | enum tcp_ca_event { | |
905 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ | |
906 | CA_EVENT_CWND_RESTART, /* congestion window restart */ | |
907 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ | |
317a76f9 | 908 | CA_EVENT_LOSS, /* loss timeout */ |
9890092e FW |
909 | CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ |
910 | CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ | |
911 | CA_EVENT_DELAYED_ACK, /* Delayed ack is sent */ | |
912 | CA_EVENT_NON_DELAYED_ACK, | |
7354c8c3 FW |
913 | }; |
914 | ||
9890092e | 915 | /* Information about inbound ACK, passed to cong_ops->in_ack_event() */ |
7354c8c3 | 916 | enum tcp_ca_ack_event_flags { |
c1d2b4c3 FW |
917 | CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ |
918 | CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ | |
919 | CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ | |
317a76f9 SH |
920 | }; |
921 | ||
922 | /* | |
923 | * Interface for adding new TCP congestion control handlers | |
924 | */ | |
925 | #define TCP_CA_NAME_MAX 16 | |
3ff825b2 SH |
926 | #define TCP_CA_MAX 128 |
927 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) | |
928 | ||
c5c6a8ab DB |
929 | #define TCP_CA_UNSPEC 0 |
930 | ||
30e502a3 | 931 | /* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ |
164891aa | 932 | #define TCP_CONG_NON_RESTRICTED 0x1 |
30e502a3 DB |
933 | /* Requires ECN/ECT set on all packets */ |
934 | #define TCP_CONG_NEEDS_ECN 0x2 | |
164891aa | 935 | |
64f40ff5 ED |
936 | union tcp_cc_info; |
937 | ||
756ee172 LB |
938 | struct ack_sample { |
939 | u32 pkts_acked; | |
940 | s32 rtt_us; | |
6f094b9e | 941 | u32 in_flight; |
756ee172 LB |
942 | }; |
943 | ||
b9f64820 YC |
944 | /* A rate sample measures the number of (original/retransmitted) data |
945 | * packets delivered "delivered" over an interval of time "interval_us". | |
946 | * The tcp_rate.c code fills in the rate sample, and congestion | |
947 | * control modules that define a cong_control function to run at the end | |
948 | * of ACK processing can optionally chose to consult this sample when | |
949 | * setting cwnd and pacing rate. | |
950 | * A sample is invalid if "delivered" or "interval_us" is negative. | |
951 | */ | |
952 | struct rate_sample { | |
9a568de4 | 953 | u64 prior_mstamp; /* starting timestamp for interval */ |
b9f64820 YC |
954 | u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ |
955 | s32 delivered; /* number of packets delivered over interval */ | |
956 | long interval_us; /* time for tp->delivered to incr "delivered" */ | |
957 | long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ | |
958 | int losses; /* number of packets marked lost upon ACK */ | |
959 | u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ | |
960 | u32 prior_in_flight; /* in flight before this ACK */ | |
d7722e85 | 961 | bool is_app_limited; /* is sample from packet with bubble in pipe? */ |
b9f64820 | 962 | bool is_retrans; /* is sample from retransmission? */ |
e4286603 | 963 | bool is_ack_delayed; /* is this (likely) a delayed ACK? */ |
b9f64820 YC |
964 | }; |
965 | ||
317a76f9 SH |
966 | struct tcp_congestion_ops { |
967 | struct list_head list; | |
c5c6a8ab DB |
968 | u32 key; |
969 | u32 flags; | |
317a76f9 SH |
970 | |
971 | /* initialize private data (optional) */ | |
6687e988 | 972 | void (*init)(struct sock *sk); |
317a76f9 | 973 | /* cleanup private data (optional) */ |
6687e988 | 974 | void (*release)(struct sock *sk); |
317a76f9 SH |
975 | |
976 | /* return slow start threshold (required) */ | |
6687e988 | 977 | u32 (*ssthresh)(struct sock *sk); |
317a76f9 | 978 | /* do new cwnd calculation (required) */ |
24901551 | 979 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); |
317a76f9 | 980 | /* call before changing ca_state (optional) */ |
6687e988 | 981 | void (*set_state)(struct sock *sk, u8 new_state); |
317a76f9 | 982 | /* call when cwnd event occurs (optional) */ |
6687e988 | 983 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
7354c8c3 FW |
984 | /* call when ack arrives (optional) */ |
985 | void (*in_ack_event)(struct sock *sk, u32 flags); | |
1e0ce2a1 | 986 | /* new value of cwnd after loss (required) */ |
6687e988 | 987 | u32 (*undo_cwnd)(struct sock *sk); |
317a76f9 | 988 | /* hook for packet ack accounting (optional) */ |
756ee172 | 989 | void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); |
dcb8c9b4 ED |
990 | /* override sysctl_tcp_min_tso_segs */ |
991 | u32 (*min_tso_segs)(struct sock *sk); | |
77bfc174 YC |
992 | /* returns the multiplier used in tcp_sndbuf_expand (optional) */ |
993 | u32 (*sndbuf_expand)(struct sock *sk); | |
c0402760 YC |
994 | /* call when packets are delivered to update cwnd and pacing rate, |
995 | * after all the ca_state processing. (optional) | |
996 | */ | |
997 | void (*cong_control)(struct sock *sk, const struct rate_sample *rs); | |
73c1f4a0 | 998 | /* get info for inet_diag (optional) */ |
64f40ff5 ED |
999 | size_t (*get_info)(struct sock *sk, u32 ext, int *attr, |
1000 | union tcp_cc_info *info); | |
317a76f9 SH |
1001 | |
1002 | char name[TCP_CA_NAME_MAX]; | |
1003 | struct module *owner; | |
1004 | }; | |
1005 | ||
5c9f3023 JP |
1006 | int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
1007 | void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); | |
317a76f9 | 1008 | |
55d8694f | 1009 | void tcp_assign_congestion_control(struct sock *sk); |
5c9f3023 JP |
1010 | void tcp_init_congestion_control(struct sock *sk); |
1011 | void tcp_cleanup_congestion_control(struct sock *sk); | |
6670e152 SH |
1012 | int tcp_set_default_congestion_control(struct net *net, const char *name); |
1013 | void tcp_get_default_congestion_control(struct net *net, char *name); | |
5c9f3023 JP |
1014 | void tcp_get_available_congestion_control(char *buf, size_t len); |
1015 | void tcp_get_allowed_congestion_control(char *buf, size_t len); | |
1016 | int tcp_set_allowed_congestion_control(char *allowed); | |
ebfa00c5 | 1017 | int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, bool reinit); |
e73ebb08 NC |
1018 | u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); |
1019 | void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); | |
317a76f9 | 1020 | |
5c9f3023 | 1021 | u32 tcp_reno_ssthresh(struct sock *sk); |
e9799183 | 1022 | u32 tcp_reno_undo_cwnd(struct sock *sk); |
24901551 | 1023 | void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); |
a8acfbac | 1024 | extern struct tcp_congestion_ops tcp_reno; |
317a76f9 | 1025 | |
c5c6a8ab | 1026 | struct tcp_congestion_ops *tcp_ca_find_key(u32 key); |
6670e152 | 1027 | u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_ca); |
ea697639 | 1028 | #ifdef CONFIG_INET |
c5c6a8ab | 1029 | char *tcp_ca_get_name_by_key(u32 key, char *buffer); |
ea697639 DB |
1030 | #else |
1031 | static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) | |
1032 | { | |
1033 | return NULL; | |
1034 | } | |
1035 | #endif | |
c5c6a8ab | 1036 | |
30e502a3 DB |
1037 | static inline bool tcp_ca_needs_ecn(const struct sock *sk) |
1038 | { | |
1039 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
1040 | ||
1041 | return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; | |
1042 | } | |
1043 | ||
6687e988 | 1044 | static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state) |
317a76f9 | 1045 | { |
6687e988 ACM |
1046 | struct inet_connection_sock *icsk = inet_csk(sk); |
1047 | ||
1048 | if (icsk->icsk_ca_ops->set_state) | |
1049 | icsk->icsk_ca_ops->set_state(sk, ca_state); | |
1050 | icsk->icsk_ca_state = ca_state; | |
317a76f9 SH |
1051 | } |
1052 | ||
6687e988 | 1053 | static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) |
317a76f9 | 1054 | { |
6687e988 ACM |
1055 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1056 | ||
1057 | if (icsk->icsk_ca_ops->cwnd_event) | |
1058 | icsk->icsk_ca_ops->cwnd_event(sk, event); | |
317a76f9 SH |
1059 | } |
1060 | ||
b9f64820 YC |
1061 | /* From tcp_rate.c */ |
1062 | void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); | |
1063 | void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, | |
1064 | struct rate_sample *rs); | |
1065 | void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, | |
d4761754 | 1066 | bool is_sack_reneg, struct rate_sample *rs); |
d7722e85 | 1067 | void tcp_rate_check_app_limited(struct sock *sk); |
b9f64820 | 1068 | |
e60402d0 IJ |
1069 | /* These functions determine how the current flow behaves in respect of SACK |
1070 | * handling. SACK is negotiated with the peer, and therefore it can vary | |
1071 | * between different flows. | |
1072 | * | |
1073 | * tcp_is_sack - SACK enabled | |
1074 | * tcp_is_reno - No SACK | |
e60402d0 IJ |
1075 | */ |
1076 | static inline int tcp_is_sack(const struct tcp_sock *tp) | |
1077 | { | |
1078 | return tp->rx_opt.sack_ok; | |
1079 | } | |
1080 | ||
a2a385d6 | 1081 | static inline bool tcp_is_reno(const struct tcp_sock *tp) |
e60402d0 IJ |
1082 | { |
1083 | return !tcp_is_sack(tp); | |
1084 | } | |
1085 | ||
83ae4088 IJ |
1086 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
1087 | { | |
1088 | return tp->sacked_out + tp->lost_out; | |
1089 | } | |
1090 | ||
1da177e4 LT |
1091 | /* This determines how many packets are "in the network" to the best |
1092 | * of our knowledge. In many cases it is conservative, but where | |
1093 | * detailed information is available from the receiver (via SACK | |
1094 | * blocks etc.) we can make more aggressive calculations. | |
1095 | * | |
1096 | * Use this for decisions involving congestion control, use just | |
1097 | * tp->packets_out to determine if the send queue is empty or not. | |
1098 | * | |
1099 | * Read this equation as: | |
1100 | * | |
1101 | * "Packets sent once on transmission queue" MINUS | |
1102 | * "Packets left network, but not honestly ACKed yet" PLUS | |
1103 | * "Packets fast retransmitted" | |
1104 | */ | |
40efc6fa | 1105 | static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
1da177e4 | 1106 | { |
83ae4088 | 1107 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
1da177e4 LT |
1108 | } |
1109 | ||
0b6a05c1 IJ |
1110 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
1111 | ||
071d5080 YC |
1112 | static inline bool tcp_in_slow_start(const struct tcp_sock *tp) |
1113 | { | |
76174004 | 1114 | return tp->snd_cwnd < tp->snd_ssthresh; |
071d5080 YC |
1115 | } |
1116 | ||
0b6a05c1 IJ |
1117 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) |
1118 | { | |
1119 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; | |
1120 | } | |
1121 | ||
684bad11 YC |
1122 | static inline bool tcp_in_cwnd_reduction(const struct sock *sk) |
1123 | { | |
1124 | return (TCPF_CA_CWR | TCPF_CA_Recovery) & | |
1125 | (1 << inet_csk(sk)->icsk_ca_state); | |
1126 | } | |
1127 | ||
1da177e4 | 1128 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
684bad11 | 1129 | * The exception is cwnd reduction phase, when cwnd is decreasing towards |
1da177e4 LT |
1130 | * ssthresh. |
1131 | */ | |
6687e988 | 1132 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
1da177e4 | 1133 | { |
6687e988 | 1134 | const struct tcp_sock *tp = tcp_sk(sk); |
cf533ea5 | 1135 | |
684bad11 | 1136 | if (tcp_in_cwnd_reduction(sk)) |
1da177e4 LT |
1137 | return tp->snd_ssthresh; |
1138 | else | |
1139 | return max(tp->snd_ssthresh, | |
1140 | ((tp->snd_cwnd >> 1) + | |
1141 | (tp->snd_cwnd >> 2))); | |
1142 | } | |
1143 | ||
b9c4595b IJ |
1144 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
1145 | #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) | |
1da177e4 | 1146 | |
5ee2c941 | 1147 | void tcp_enter_cwr(struct sock *sk); |
5c9f3023 | 1148 | __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); |
1da177e4 | 1149 | |
6b5a5c0d NC |
1150 | /* The maximum number of MSS of available cwnd for which TSO defers |
1151 | * sending if not using sysctl_tcp_tso_win_divisor. | |
1152 | */ | |
1153 | static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) | |
1154 | { | |
1155 | return 3; | |
1156 | } | |
1157 | ||
90840def IJ |
1158 | /* Returns end sequence number of the receiver's advertised window */ |
1159 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) | |
1160 | { | |
1161 | return tp->snd_una + tp->snd_wnd; | |
1162 | } | |
e114a710 ED |
1163 | |
1164 | /* We follow the spirit of RFC2861 to validate cwnd but implement a more | |
1165 | * flexible approach. The RFC suggests cwnd should not be raised unless | |
ca8a2263 NC |
1166 | * it was fully used previously. And that's exactly what we do in |
1167 | * congestion avoidance mode. But in slow start we allow cwnd to grow | |
1168 | * as long as the application has used half the cwnd. | |
e114a710 ED |
1169 | * Example : |
1170 | * cwnd is 10 (IW10), but application sends 9 frames. | |
1171 | * We allow cwnd to reach 18 when all frames are ACKed. | |
1172 | * This check is safe because it's as aggressive as slow start which already | |
1173 | * risks 100% overshoot. The advantage is that we discourage application to | |
1174 | * either send more filler packets or data to artificially blow up the cwnd | |
1175 | * usage, and allow application-limited process to probe bw more aggressively. | |
e114a710 | 1176 | */ |
24901551 | 1177 | static inline bool tcp_is_cwnd_limited(const struct sock *sk) |
e114a710 ED |
1178 | { |
1179 | const struct tcp_sock *tp = tcp_sk(sk); | |
1180 | ||
ca8a2263 | 1181 | /* If in slow start, ensure cwnd grows to twice what was ACKed. */ |
071d5080 | 1182 | if (tcp_in_slow_start(tp)) |
ca8a2263 NC |
1183 | return tp->snd_cwnd < 2 * tp->max_packets_out; |
1184 | ||
1185 | return tp->is_cwnd_limited; | |
e114a710 | 1186 | } |
f4805ede | 1187 | |
21c8fe99 ED |
1188 | /* Something is really bad, we could not queue an additional packet, |
1189 | * because qdisc is full or receiver sent a 0 window. | |
1190 | * We do not want to add fuel to the fire, or abort too early, | |
1191 | * so make sure the timer we arm now is at least 200ms in the future, | |
1192 | * regardless of current icsk_rto value (as it could be ~2ms) | |
1193 | */ | |
1194 | static inline unsigned long tcp_probe0_base(const struct sock *sk) | |
1da177e4 | 1195 | { |
21c8fe99 ED |
1196 | return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); |
1197 | } | |
9e412ba7 | 1198 | |
21c8fe99 ED |
1199 | /* Variant of inet_csk_rto_backoff() used for zero window probes */ |
1200 | static inline unsigned long tcp_probe0_when(const struct sock *sk, | |
1201 | unsigned long max_when) | |
1202 | { | |
1203 | u64 when = (u64)tcp_probe0_base(sk) << inet_csk(sk)->icsk_backoff; | |
1204 | ||
1205 | return (unsigned long)min_t(u64, when, max_when); | |
1206 | } | |
1207 | ||
1208 | static inline void tcp_check_probe_timer(struct sock *sk) | |
1209 | { | |
1210 | if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) | |
3f421baa | 1211 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
21c8fe99 | 1212 | tcp_probe0_base(sk), TCP_RTO_MAX); |
1da177e4 LT |
1213 | } |
1214 | ||
ee7537b6 | 1215 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
1216 | { |
1217 | tp->snd_wl1 = seq; | |
1218 | } | |
1219 | ||
ee7537b6 | 1220 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
1221 | { |
1222 | tp->snd_wl1 = seq; | |
1223 | } | |
1224 | ||
1da177e4 LT |
1225 | /* |
1226 | * Calculate(/check) TCP checksum | |
1227 | */ | |
ba7808ea FD |
1228 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
1229 | __be32 daddr, __wsum base) | |
1da177e4 LT |
1230 | { |
1231 | return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); | |
1232 | } | |
1233 | ||
b51655b9 | 1234 | static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb) |
1da177e4 | 1235 | { |
fb286bb2 | 1236 | return __skb_checksum_complete(skb); |
1da177e4 LT |
1237 | } |
1238 | ||
a2a385d6 | 1239 | static inline bool tcp_checksum_complete(struct sk_buff *skb) |
1da177e4 | 1240 | { |
60476372 | 1241 | return !skb_csum_unnecessary(skb) && |
1da177e4 LT |
1242 | __tcp_checksum_complete(skb); |
1243 | } | |
1244 | ||
c9c33212 | 1245 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb); |
ac6e7800 | 1246 | int tcp_filter(struct sock *sk, struct sk_buff *skb); |
1da177e4 LT |
1247 | |
1248 | #undef STATE_TRACE | |
1249 | ||
1250 | #ifdef STATE_TRACE | |
1251 | static const char *statename[]={ | |
1252 | "Unused","Established","Syn Sent","Syn Recv", | |
1253 | "Fin Wait 1","Fin Wait 2","Time Wait", "Close", | |
1254 | "Close Wait","Last ACK","Listen","Closing" | |
1255 | }; | |
1256 | #endif | |
5c9f3023 | 1257 | void tcp_set_state(struct sock *sk, int state); |
1da177e4 | 1258 | |
5c9f3023 | 1259 | void tcp_done(struct sock *sk); |
1da177e4 | 1260 | |
c1e64e29 LC |
1261 | int tcp_abort(struct sock *sk, int err); |
1262 | ||
40efc6fa | 1263 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
1da177e4 LT |
1264 | { |
1265 | rx_opt->dsack = 0; | |
1da177e4 LT |
1266 | rx_opt->num_sacks = 0; |
1267 | } | |
1268 | ||
5c9f3023 | 1269 | u32 tcp_default_init_rwnd(u32 mss); |
6f021c62 ED |
1270 | void tcp_cwnd_restart(struct sock *sk, s32 delta); |
1271 | ||
1272 | static inline void tcp_slow_start_after_idle_check(struct sock *sk) | |
1273 | { | |
1b1fc3fd | 1274 | const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; |
6f021c62 ED |
1275 | struct tcp_sock *tp = tcp_sk(sk); |
1276 | s32 delta; | |
1277 | ||
b510f0d2 | 1278 | if (!sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle || tp->packets_out || |
1b1fc3fd | 1279 | ca_ops->cong_control) |
6f021c62 | 1280 | return; |
d635fbe2 | 1281 | delta = tcp_jiffies32 - tp->lsndtime; |
6f021c62 ED |
1282 | if (delta > inet_csk(sk)->icsk_rto) |
1283 | tcp_cwnd_restart(sk, delta); | |
1284 | } | |
85f16525 | 1285 | |
1da177e4 | 1286 | /* Determine a window scaling and initial window to offer. */ |
ceef9ab6 ED |
1287 | void tcp_select_initial_window(const struct sock *sk, int __space, |
1288 | __u32 mss, __u32 *rcv_wnd, | |
5c9f3023 JP |
1289 | __u32 *window_clamp, int wscale_ok, |
1290 | __u8 *rcv_wscale, __u32 init_rcv_wnd); | |
1da177e4 | 1291 | |
94f0893e | 1292 | static inline int tcp_win_from_space(const struct sock *sk, int space) |
1da177e4 | 1293 | { |
94f0893e | 1294 | int tcp_adv_win_scale = sock_net(sk)->ipv4.sysctl_tcp_adv_win_scale; |
c4836742 GF |
1295 | |
1296 | return tcp_adv_win_scale <= 0 ? | |
1297 | (space>>(-tcp_adv_win_scale)) : | |
1298 | space - (space>>tcp_adv_win_scale); | |
1da177e4 LT |
1299 | } |
1300 | ||
105970f6 | 1301 | /* Note: caller must be prepared to deal with negative returns */ |
1da177e4 LT |
1302 | static inline int tcp_space(const struct sock *sk) |
1303 | { | |
94f0893e | 1304 | return tcp_win_from_space(sk, sk->sk_rcvbuf - |
1da177e4 | 1305 | atomic_read(&sk->sk_rmem_alloc)); |
105970f6 | 1306 | } |
1da177e4 LT |
1307 | |
1308 | static inline int tcp_full_space(const struct sock *sk) | |
1309 | { | |
94f0893e | 1310 | return tcp_win_from_space(sk, sk->sk_rcvbuf); |
1da177e4 LT |
1311 | } |
1312 | ||
843f4a55 | 1313 | extern void tcp_openreq_init_rwin(struct request_sock *req, |
b1964b5f ED |
1314 | const struct sock *sk_listener, |
1315 | const struct dst_entry *dst); | |
843f4a55 | 1316 | |
5c9f3023 | 1317 | void tcp_enter_memory_pressure(struct sock *sk); |
06044751 | 1318 | void tcp_leave_memory_pressure(struct sock *sk); |
1da177e4 | 1319 | |
1da177e4 LT |
1320 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
1321 | { | |
b840d15d NB |
1322 | struct net *net = sock_net((struct sock *)tp); |
1323 | ||
1324 | return tp->keepalive_intvl ? : net->ipv4.sysctl_tcp_keepalive_intvl; | |
1da177e4 LT |
1325 | } |
1326 | ||
1327 | static inline int keepalive_time_when(const struct tcp_sock *tp) | |
1328 | { | |
13b287e8 NB |
1329 | struct net *net = sock_net((struct sock *)tp); |
1330 | ||
1331 | return tp->keepalive_time ? : net->ipv4.sysctl_tcp_keepalive_time; | |
1da177e4 LT |
1332 | } |
1333 | ||
df19a626 ED |
1334 | static inline int keepalive_probes(const struct tcp_sock *tp) |
1335 | { | |
9bd6861b NB |
1336 | struct net *net = sock_net((struct sock *)tp); |
1337 | ||
1338 | return tp->keepalive_probes ? : net->ipv4.sysctl_tcp_keepalive_probes; | |
df19a626 ED |
1339 | } |
1340 | ||
6c37e5de FL |
1341 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
1342 | { | |
1343 | const struct inet_connection_sock *icsk = &tp->inet_conn; | |
1344 | ||
70eabf0e ED |
1345 | return min_t(u32, tcp_jiffies32 - icsk->icsk_ack.lrcvtime, |
1346 | tcp_jiffies32 - tp->rcv_tstamp); | |
6c37e5de FL |
1347 | } |
1348 | ||
463c84b9 | 1349 | static inline int tcp_fin_time(const struct sock *sk) |
1da177e4 | 1350 | { |
1e579caa | 1351 | int fin_timeout = tcp_sk(sk)->linger2 ? : sock_net(sk)->ipv4.sysctl_tcp_fin_timeout; |
463c84b9 | 1352 | const int rto = inet_csk(sk)->icsk_rto; |
1da177e4 | 1353 | |
463c84b9 ACM |
1354 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
1355 | fin_timeout = (rto << 2) - (rto >> 1); | |
1da177e4 LT |
1356 | |
1357 | return fin_timeout; | |
1358 | } | |
1359 | ||
a2a385d6 ED |
1360 | static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, |
1361 | int paws_win) | |
1da177e4 | 1362 | { |
c887e6d2 | 1363 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
a2a385d6 | 1364 | return true; |
c887e6d2 | 1365 | if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)) |
a2a385d6 | 1366 | return true; |
bc2ce894 ED |
1367 | /* |
1368 | * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, | |
1369 | * then following tcp messages have valid values. Ignore 0 value, | |
1370 | * or else 'negative' tsval might forbid us to accept their packets. | |
1371 | */ | |
1372 | if (!rx_opt->ts_recent) | |
a2a385d6 ED |
1373 | return true; |
1374 | return false; | |
c887e6d2 IJ |
1375 | } |
1376 | ||
a2a385d6 ED |
1377 | static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, |
1378 | int rst) | |
c887e6d2 IJ |
1379 | { |
1380 | if (tcp_paws_check(rx_opt, 0)) | |
a2a385d6 | 1381 | return false; |
1da177e4 LT |
1382 | |
1383 | /* RST segments are not recommended to carry timestamp, | |
1384 | and, if they do, it is recommended to ignore PAWS because | |
1385 | "their cleanup function should take precedence over timestamps." | |
1386 | Certainly, it is mistake. It is necessary to understand the reasons | |
1387 | of this constraint to relax it: if peer reboots, clock may go | |
1388 | out-of-sync and half-open connections will not be reset. | |
1389 | Actually, the problem would be not existing if all | |
1390 | the implementations followed draft about maintaining clock | |
1391 | via reboots. Linux-2.2 DOES NOT! | |
1392 | ||
1393 | However, we can relax time bounds for RST segments to MSL. | |
1394 | */ | |
9d729f72 | 1395 | if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) |
a2a385d6 ED |
1396 | return false; |
1397 | return true; | |
1da177e4 LT |
1398 | } |
1399 | ||
7970ddc8 ED |
1400 | bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, |
1401 | int mib_idx, u32 *last_oow_ack_time); | |
032ee423 | 1402 | |
a9c19329 | 1403 | static inline void tcp_mib_init(struct net *net) |
1da177e4 LT |
1404 | { |
1405 | /* See RFC 2012 */ | |
6aef70a8 ED |
1406 | TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); |
1407 | TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); | |
1408 | TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); | |
1409 | TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); | |
1da177e4 LT |
1410 | } |
1411 | ||
5af4ec23 | 1412 | /* from STCP */ |
ef9da47c | 1413 | static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) |
0800f170 | 1414 | { |
6a438bbe | 1415 | tp->lost_skb_hint = NULL; |
ef9da47c IJ |
1416 | } |
1417 | ||
1418 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) | |
1419 | { | |
1420 | tcp_clear_retrans_hints_partial(tp); | |
6a438bbe | 1421 | tp->retransmit_skb_hint = NULL; |
b7689205 IJ |
1422 | } |
1423 | ||
a915da9b ED |
1424 | union tcp_md5_addr { |
1425 | struct in_addr a4; | |
1426 | #if IS_ENABLED(CONFIG_IPV6) | |
1427 | struct in6_addr a6; | |
1428 | #endif | |
1429 | }; | |
1430 | ||
cfb6eeb4 YH |
1431 | /* - key database */ |
1432 | struct tcp_md5sig_key { | |
a915da9b | 1433 | struct hlist_node node; |
cfb6eeb4 | 1434 | u8 keylen; |
a915da9b ED |
1435 | u8 family; /* AF_INET or AF_INET6 */ |
1436 | union tcp_md5_addr addr; | |
6797318e | 1437 | u8 prefixlen; |
a915da9b ED |
1438 | u8 key[TCP_MD5SIG_MAXKEYLEN]; |
1439 | struct rcu_head rcu; | |
cfb6eeb4 YH |
1440 | }; |
1441 | ||
1442 | /* - sock block */ | |
1443 | struct tcp_md5sig_info { | |
a915da9b | 1444 | struct hlist_head head; |
a8afca03 | 1445 | struct rcu_head rcu; |
cfb6eeb4 YH |
1446 | }; |
1447 | ||
1448 | /* - pseudo header */ | |
1449 | struct tcp4_pseudohdr { | |
1450 | __be32 saddr; | |
1451 | __be32 daddr; | |
1452 | __u8 pad; | |
1453 | __u8 protocol; | |
1454 | __be16 len; | |
1455 | }; | |
1456 | ||
1457 | struct tcp6_pseudohdr { | |
1458 | struct in6_addr saddr; | |
1459 | struct in6_addr daddr; | |
1460 | __be32 len; | |
1461 | __be32 protocol; /* including padding */ | |
1462 | }; | |
1463 | ||
1464 | union tcp_md5sum_block { | |
1465 | struct tcp4_pseudohdr ip4; | |
dfd56b8b | 1466 | #if IS_ENABLED(CONFIG_IPV6) |
cfb6eeb4 YH |
1467 | struct tcp6_pseudohdr ip6; |
1468 | #endif | |
1469 | }; | |
1470 | ||
1471 | /* - pool: digest algorithm, hash description and scratch buffer */ | |
1472 | struct tcp_md5sig_pool { | |
cf80e0e4 | 1473 | struct ahash_request *md5_req; |
19689e38 | 1474 | void *scratch; |
cfb6eeb4 YH |
1475 | }; |
1476 | ||
cfb6eeb4 | 1477 | /* - functions */ |
39f8e58e ED |
1478 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
1479 | const struct sock *sk, const struct sk_buff *skb); | |
5c9f3023 | 1480 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
6797318e ID |
1481 | int family, u8 prefixlen, const u8 *newkey, u8 newkeylen, |
1482 | gfp_t gfp); | |
5c9f3023 | 1483 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, |
6797318e | 1484 | int family, u8 prefixlen); |
b83e3deb | 1485 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
fd3a154a | 1486 | const struct sock *addr_sk); |
cfb6eeb4 | 1487 | |
9501f972 | 1488 | #ifdef CONFIG_TCP_MD5SIG |
b83e3deb | 1489 | struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, |
5c9f3023 JP |
1490 | const union tcp_md5_addr *addr, |
1491 | int family); | |
a915da9b | 1492 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) |
9501f972 | 1493 | #else |
b83e3deb | 1494 | static inline struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, |
a915da9b ED |
1495 | const union tcp_md5_addr *addr, |
1496 | int family) | |
1497 | { | |
1498 | return NULL; | |
1499 | } | |
9501f972 YH |
1500 | #define tcp_twsk_md5_key(twsk) NULL |
1501 | #endif | |
1502 | ||
5c9f3023 | 1503 | bool tcp_alloc_md5sig_pool(void); |
cfb6eeb4 | 1504 | |
5c9f3023 | 1505 | struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); |
71cea17e ED |
1506 | static inline void tcp_put_md5sig_pool(void) |
1507 | { | |
1508 | local_bh_enable(); | |
1509 | } | |
35790c04 | 1510 | |
5c9f3023 JP |
1511 | int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *, |
1512 | unsigned int header_len); | |
1513 | int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, | |
1514 | const struct tcp_md5sig_key *key); | |
cfb6eeb4 | 1515 | |
10467163 | 1516 | /* From tcp_fastopen.c */ |
5c9f3023 | 1517 | void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
7268586b | 1518 | struct tcp_fastopen_cookie *cookie); |
5c9f3023 | 1519 | void tcp_fastopen_cache_set(struct sock *sk, u16 mss, |
2646c831 DL |
1520 | struct tcp_fastopen_cookie *cookie, bool syn_lost, |
1521 | u16 try_exp); | |
783237e8 YC |
1522 | struct tcp_fastopen_request { |
1523 | /* Fast Open cookie. Size 0 means a cookie request */ | |
1524 | struct tcp_fastopen_cookie cookie; | |
1525 | struct msghdr *data; /* data in MSG_FASTOPEN */ | |
f5ddcbbb ED |
1526 | size_t size; |
1527 | int copied; /* queued in tcp_connect() */ | |
783237e8 | 1528 | }; |
783237e8 | 1529 | void tcp_free_fastopen_req(struct tcp_sock *tp); |
1fba70e5 | 1530 | void tcp_fastopen_destroy_cipher(struct sock *sk); |
43713848 | 1531 | void tcp_fastopen_ctx_destroy(struct net *net); |
1fba70e5 YC |
1532 | int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, |
1533 | void *key, unsigned int len); | |
61d2bcae | 1534 | void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); |
7c85af88 ED |
1535 | struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, |
1536 | struct request_sock *req, | |
71c02379 CP |
1537 | struct tcp_fastopen_cookie *foc, |
1538 | const struct dst_entry *dst); | |
43713848 | 1539 | void tcp_fastopen_init_key_once(struct net *net); |
065263f4 WW |
1540 | bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, |
1541 | struct tcp_fastopen_cookie *cookie); | |
19f6d3f3 | 1542 | bool tcp_fastopen_defer_connect(struct sock *sk, int *err); |
10467163 JC |
1543 | #define TCP_FASTOPEN_KEY_LENGTH 16 |
1544 | ||
1545 | /* Fastopen key context */ | |
1546 | struct tcp_fastopen_context { | |
7ae8639c ED |
1547 | struct crypto_cipher *tfm; |
1548 | __u8 key[TCP_FASTOPEN_KEY_LENGTH]; | |
1549 | struct rcu_head rcu; | |
10467163 JC |
1550 | }; |
1551 | ||
cf1ef3f0 | 1552 | extern unsigned int sysctl_tcp_fastopen_blackhole_timeout; |
46c2fa39 | 1553 | void tcp_fastopen_active_disable(struct sock *sk); |
cf1ef3f0 WW |
1554 | bool tcp_fastopen_active_should_disable(struct sock *sk); |
1555 | void tcp_fastopen_active_disable_ofo_check(struct sock *sk); | |
7268586b | 1556 | void tcp_fastopen_active_detect_blackhole(struct sock *sk, bool expired); |
cf1ef3f0 | 1557 | |
05b055e8 FY |
1558 | /* Latencies incurred by various limits for a sender. They are |
1559 | * chronograph-like stats that are mutually exclusive. | |
1560 | */ | |
1561 | enum tcp_chrono { | |
1562 | TCP_CHRONO_UNSPEC, | |
1563 | TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ | |
1564 | TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ | |
1565 | TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ | |
1566 | __TCP_CHRONO_MAX, | |
1567 | }; | |
1568 | ||
1569 | void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); | |
1570 | void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); | |
1571 | ||
e2080072 ED |
1572 | /* This helper is needed, because skb->tcp_tsorted_anchor uses |
1573 | * the same memory storage than skb->destructor/_skb_refdst | |
1574 | */ | |
1575 | static inline void tcp_skb_tsorted_anchor_cleanup(struct sk_buff *skb) | |
1576 | { | |
1577 | skb->destructor = NULL; | |
1578 | skb->_skb_refdst = 0UL; | |
1579 | } | |
1580 | ||
1581 | #define tcp_skb_tsorted_save(skb) { \ | |
1582 | unsigned long _save = skb->_skb_refdst; \ | |
1583 | skb->_skb_refdst = 0UL; | |
1584 | ||
1585 | #define tcp_skb_tsorted_restore(skb) \ | |
1586 | skb->_skb_refdst = _save; \ | |
1587 | } | |
1588 | ||
ac3f09ba | 1589 | void tcp_write_queue_purge(struct sock *sk); |
fe067e8a | 1590 | |
75c119af ED |
1591 | static inline struct sk_buff *tcp_rtx_queue_head(const struct sock *sk) |
1592 | { | |
1593 | return skb_rb_first(&sk->tcp_rtx_queue); | |
1594 | } | |
1595 | ||
cf533ea5 | 1596 | static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) |
fe067e8a | 1597 | { |
cd07a8ea | 1598 | return skb_peek(&sk->sk_write_queue); |
fe067e8a DM |
1599 | } |
1600 | ||
cf533ea5 | 1601 | static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) |
fe067e8a | 1602 | { |
cd07a8ea | 1603 | return skb_peek_tail(&sk->sk_write_queue); |
fe067e8a DM |
1604 | } |
1605 | ||
234b6860 | 1606 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
cd07a8ea | 1607 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
234b6860 | 1608 | |
cf533ea5 | 1609 | static inline struct sk_buff *tcp_send_head(const struct sock *sk) |
fe067e8a | 1610 | { |
75c119af | 1611 | return skb_peek(&sk->sk_write_queue); |
fe067e8a DM |
1612 | } |
1613 | ||
cd07a8ea DM |
1614 | static inline bool tcp_skb_is_last(const struct sock *sk, |
1615 | const struct sk_buff *skb) | |
1616 | { | |
1617 | return skb_queue_is_last(&sk->sk_write_queue, skb); | |
1618 | } | |
1619 | ||
75c119af | 1620 | static inline bool tcp_write_queue_empty(const struct sock *sk) |
fe067e8a | 1621 | { |
75c119af ED |
1622 | return skb_queue_empty(&sk->sk_write_queue); |
1623 | } | |
1624 | ||
1625 | static inline bool tcp_rtx_queue_empty(const struct sock *sk) | |
1626 | { | |
1627 | return RB_EMPTY_ROOT(&sk->tcp_rtx_queue); | |
1628 | } | |
1629 | ||
1630 | static inline bool tcp_rtx_and_write_queues_empty(const struct sock *sk) | |
1631 | { | |
1632 | return tcp_rtx_queue_empty(sk) && tcp_write_queue_empty(sk); | |
fe067e8a DM |
1633 | } |
1634 | ||
1635 | static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked) | |
1636 | { | |
75c119af | 1637 | if (tcp_write_queue_empty(sk)) |
0f87230d | 1638 | tcp_chrono_stop(sk, TCP_CHRONO_BUSY); |
fe067e8a DM |
1639 | } |
1640 | ||
fe067e8a DM |
1641 | static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) |
1642 | { | |
1643 | __skb_queue_tail(&sk->sk_write_queue, skb); | |
1644 | } | |
1645 | ||
1646 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) | |
1647 | { | |
1648 | __tcp_add_write_queue_tail(sk, skb); | |
1649 | ||
1650 | /* Queue it, remembering where we must start sending. */ | |
50895b9d | 1651 | if (sk->sk_write_queue.next == skb) |
0f87230d | 1652 | tcp_chrono_start(sk, TCP_CHRONO_BUSY); |
fe067e8a DM |
1653 | } |
1654 | ||
43f59c89 | 1655 | /* Insert new before skb on the write queue of sk. */ |
fe067e8a DM |
1656 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
1657 | struct sk_buff *skb, | |
1658 | struct sock *sk) | |
1659 | { | |
43f59c89 | 1660 | __skb_queue_before(&sk->sk_write_queue, skb, new); |
fe067e8a DM |
1661 | } |
1662 | ||
1663 | static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) | |
1664 | { | |
4a269818 | 1665 | tcp_skb_tsorted_anchor_cleanup(skb); |
fe067e8a DM |
1666 | __skb_unlink(skb, &sk->sk_write_queue); |
1667 | } | |
1668 | ||
75c119af ED |
1669 | void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb); |
1670 | ||
1671 | static inline void tcp_rtx_queue_unlink(struct sk_buff *skb, struct sock *sk) | |
fe067e8a | 1672 | { |
75c119af ED |
1673 | tcp_skb_tsorted_anchor_cleanup(skb); |
1674 | rb_erase(&skb->rbnode, &sk->tcp_rtx_queue); | |
1675 | } | |
1676 | ||
1677 | static inline void tcp_rtx_queue_unlink_and_free(struct sk_buff *skb, struct sock *sk) | |
1678 | { | |
1679 | list_del(&skb->tcp_tsorted_anchor); | |
1680 | tcp_rtx_queue_unlink(skb, sk); | |
1681 | sk_wmem_free_skb(sk, skb); | |
fe067e8a DM |
1682 | } |
1683 | ||
12d50c46 KK |
1684 | static inline void tcp_push_pending_frames(struct sock *sk) |
1685 | { | |
1686 | if (tcp_send_head(sk)) { | |
1687 | struct tcp_sock *tp = tcp_sk(sk); | |
1688 | ||
1689 | __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); | |
1690 | } | |
1691 | } | |
1692 | ||
ecb97192 NC |
1693 | /* Start sequence of the skb just after the highest skb with SACKed |
1694 | * bit, valid only if sacked_out > 0 or when the caller has ensured | |
1695 | * validity by itself. | |
a47e5a98 IJ |
1696 | */ |
1697 | static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) | |
1698 | { | |
1699 | if (!tp->sacked_out) | |
1700 | return tp->snd_una; | |
6859d494 IJ |
1701 | |
1702 | if (tp->highest_sack == NULL) | |
1703 | return tp->snd_nxt; | |
1704 | ||
a47e5a98 IJ |
1705 | return TCP_SKB_CB(tp->highest_sack)->seq; |
1706 | } | |
1707 | ||
6859d494 IJ |
1708 | static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) |
1709 | { | |
50895b9d | 1710 | tcp_sk(sk)->highest_sack = skb_rb_next(skb); |
6859d494 IJ |
1711 | } |
1712 | ||
1713 | static inline struct sk_buff *tcp_highest_sack(struct sock *sk) | |
1714 | { | |
1715 | return tcp_sk(sk)->highest_sack; | |
1716 | } | |
1717 | ||
1718 | static inline void tcp_highest_sack_reset(struct sock *sk) | |
1719 | { | |
50895b9d | 1720 | tcp_sk(sk)->highest_sack = tcp_rtx_queue_head(sk); |
6859d494 IJ |
1721 | } |
1722 | ||
2b7cda9c ED |
1723 | /* Called when old skb is about to be deleted and replaced by new skb */ |
1724 | static inline void tcp_highest_sack_replace(struct sock *sk, | |
6859d494 IJ |
1725 | struct sk_buff *old, |
1726 | struct sk_buff *new) | |
1727 | { | |
2b7cda9c | 1728 | if (old == tcp_highest_sack(sk)) |
6859d494 IJ |
1729 | tcp_sk(sk)->highest_sack = new; |
1730 | } | |
1731 | ||
b1f0a0e9 FW |
1732 | /* This helper checks if socket has IP_TRANSPARENT set */ |
1733 | static inline bool inet_sk_transparent(const struct sock *sk) | |
1734 | { | |
1735 | switch (sk->sk_state) { | |
1736 | case TCP_TIME_WAIT: | |
1737 | return inet_twsk(sk)->tw_transparent; | |
1738 | case TCP_NEW_SYN_RECV: | |
1739 | return inet_rsk(inet_reqsk(sk))->no_srccheck; | |
1740 | } | |
1741 | return inet_sk(sk)->transparent; | |
1742 | } | |
1743 | ||
5aa4b32f AP |
1744 | /* Determines whether this is a thin stream (which may suffer from |
1745 | * increased latency). Used to trigger latency-reducing mechanisms. | |
1746 | */ | |
a2a385d6 | 1747 | static inline bool tcp_stream_is_thin(struct tcp_sock *tp) |
5aa4b32f AP |
1748 | { |
1749 | return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); | |
1750 | } | |
1751 | ||
1da177e4 LT |
1752 | /* /proc */ |
1753 | enum tcp_seq_states { | |
1754 | TCP_SEQ_STATE_LISTENING, | |
1da177e4 | 1755 | TCP_SEQ_STATE_ESTABLISHED, |
1da177e4 LT |
1756 | }; |
1757 | ||
37d849bb CH |
1758 | void *tcp_seq_start(struct seq_file *seq, loff_t *pos); |
1759 | void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos); | |
1760 | void tcp_seq_stop(struct seq_file *seq, void *v); | |
73cb88ec | 1761 | |
1da177e4 | 1762 | struct tcp_seq_afinfo { |
73cb88ec | 1763 | sa_family_t family; |
1da177e4 LT |
1764 | }; |
1765 | ||
1766 | struct tcp_iter_state { | |
a4146b1b | 1767 | struct seq_net_private p; |
1da177e4 LT |
1768 | enum tcp_seq_states state; |
1769 | struct sock *syn_wait_sk; | |
a7cb5a49 | 1770 | int bucket, offset, sbucket, num; |
a8b690f9 | 1771 | loff_t last_pos; |
1da177e4 LT |
1772 | }; |
1773 | ||
20380731 | 1774 | extern struct request_sock_ops tcp_request_sock_ops; |
c6aefafb | 1775 | extern struct request_sock_ops tcp6_request_sock_ops; |
20380731 | 1776 | |
5c9f3023 | 1777 | void tcp_v4_destroy_sock(struct sock *sk); |
20380731 | 1778 | |
28be6e07 | 1779 | struct sk_buff *tcp_gso_segment(struct sk_buff *skb, |
5c9f3023 JP |
1780 | netdev_features_t features); |
1781 | struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb); | |
1782 | int tcp_gro_complete(struct sk_buff *skb); | |
28850dc7 | 1783 | |
5c9f3023 | 1784 | void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); |
f4c50d99 | 1785 | |
c9bee3b7 ED |
1786 | static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) |
1787 | { | |
4979f2d9 NB |
1788 | struct net *net = sock_net((struct sock *)tp); |
1789 | return tp->notsent_lowat ?: net->ipv4.sysctl_tcp_notsent_lowat; | |
c9bee3b7 ED |
1790 | } |
1791 | ||
1792 | static inline bool tcp_stream_memory_free(const struct sock *sk) | |
1793 | { | |
1794 | const struct tcp_sock *tp = tcp_sk(sk); | |
1795 | u32 notsent_bytes = tp->write_seq - tp->snd_nxt; | |
1796 | ||
1797 | return notsent_bytes < tcp_notsent_lowat(tp); | |
1798 | } | |
1799 | ||
20380731 | 1800 | #ifdef CONFIG_PROC_FS |
5c9f3023 JP |
1801 | int tcp4_proc_init(void); |
1802 | void tcp4_proc_exit(void); | |
20380731 ACM |
1803 | #endif |
1804 | ||
ea3bea3a | 1805 | int tcp_rtx_synack(const struct sock *sk, struct request_sock *req); |
1fb6f159 OP |
1806 | int tcp_conn_request(struct request_sock_ops *rsk_ops, |
1807 | const struct tcp_request_sock_ops *af_ops, | |
1808 | struct sock *sk, struct sk_buff *skb); | |
5db92c99 | 1809 | |
cfb6eeb4 YH |
1810 | /* TCP af-specific functions */ |
1811 | struct tcp_sock_af_ops { | |
1812 | #ifdef CONFIG_TCP_MD5SIG | |
b83e3deb | 1813 | struct tcp_md5sig_key *(*md5_lookup) (const struct sock *sk, |
fd3a154a | 1814 | const struct sock *addr_sk); |
39f8e58e ED |
1815 | int (*calc_md5_hash)(char *location, |
1816 | const struct tcp_md5sig_key *md5, | |
1817 | const struct sock *sk, | |
1818 | const struct sk_buff *skb); | |
1819 | int (*md5_parse)(struct sock *sk, | |
8917a777 | 1820 | int optname, |
39f8e58e ED |
1821 | char __user *optval, |
1822 | int optlen); | |
cfb6eeb4 YH |
1823 | #endif |
1824 | }; | |
1825 | ||
1826 | struct tcp_request_sock_ops { | |
2aec4a29 | 1827 | u16 mss_clamp; |
cfb6eeb4 | 1828 | #ifdef CONFIG_TCP_MD5SIG |
b83e3deb | 1829 | struct tcp_md5sig_key *(*req_md5_lookup)(const struct sock *sk, |
fd3a154a | 1830 | const struct sock *addr_sk); |
39f8e58e ED |
1831 | int (*calc_md5_hash) (char *location, |
1832 | const struct tcp_md5sig_key *md5, | |
1833 | const struct sock *sk, | |
1834 | const struct sk_buff *skb); | |
cfb6eeb4 | 1835 | #endif |
b40cf18e ED |
1836 | void (*init_req)(struct request_sock *req, |
1837 | const struct sock *sk_listener, | |
16bea70a | 1838 | struct sk_buff *skb); |
fb7b37a7 | 1839 | #ifdef CONFIG_SYN_COOKIES |
3f684b4b | 1840 | __u32 (*cookie_init_seq)(const struct sk_buff *skb, |
fb7b37a7 OP |
1841 | __u16 *mss); |
1842 | #endif | |
f964629e | 1843 | struct dst_entry *(*route_req)(const struct sock *sk, struct flowi *fl, |
4396e461 | 1844 | const struct request_sock *req); |
84b114b9 | 1845 | u32 (*init_seq)(const struct sk_buff *skb); |
5d2ed052 | 1846 | u32 (*init_ts_off)(const struct net *net, const struct sk_buff *skb); |
0f935dbe | 1847 | int (*send_synack)(const struct sock *sk, struct dst_entry *dst, |
d6274bd8 | 1848 | struct flowi *fl, struct request_sock *req, |
dc6ef6be | 1849 | struct tcp_fastopen_cookie *foc, |
b3d05147 | 1850 | enum tcp_synack_type synack_type); |
cfb6eeb4 YH |
1851 | }; |
1852 | ||
fb7b37a7 OP |
1853 | #ifdef CONFIG_SYN_COOKIES |
1854 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, | |
3f684b4b | 1855 | const struct sock *sk, struct sk_buff *skb, |
fb7b37a7 OP |
1856 | __u16 *mss) |
1857 | { | |
3f684b4b | 1858 | tcp_synq_overflow(sk); |
02a1d6e7 | 1859 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); |
3f684b4b | 1860 | return ops->cookie_init_seq(skb, mss); |
fb7b37a7 OP |
1861 | } |
1862 | #else | |
1863 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, | |
3f684b4b | 1864 | const struct sock *sk, struct sk_buff *skb, |
fb7b37a7 OP |
1865 | __u16 *mss) |
1866 | { | |
1867 | return 0; | |
1868 | } | |
1869 | #endif | |
1870 | ||
5c9f3023 | 1871 | int tcpv4_offload_init(void); |
28850dc7 | 1872 | |
5c9f3023 JP |
1873 | void tcp_v4_init(void); |
1874 | void tcp_init(void); | |
20380731 | 1875 | |
659a8ad5 | 1876 | /* tcp_recovery.c */ |
d716bfdb | 1877 | void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb); |
6ac06ecd | 1878 | void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced); |
b8fef65a YC |
1879 | extern s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, |
1880 | u32 reo_wnd); | |
128eda86 | 1881 | extern void tcp_rack_mark_lost(struct sock *sk); |
1d0833df | 1882 | extern void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, |
9a568de4 | 1883 | u64 xmit_time); |
57dde7f7 | 1884 | extern void tcp_rack_reo_timeout(struct sock *sk); |
1f255691 | 1885 | extern void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs); |
659a8ad5 | 1886 | |
e1a10ef7 NC |
1887 | /* At how many usecs into the future should the RTO fire? */ |
1888 | static inline s64 tcp_rto_delta_us(const struct sock *sk) | |
1889 | { | |
75c119af | 1890 | const struct sk_buff *skb = tcp_rtx_queue_head(sk); |
e1a10ef7 NC |
1891 | u32 rto = inet_csk(sk)->icsk_rto; |
1892 | u64 rto_time_stamp_us = skb->skb_mstamp + jiffies_to_usecs(rto); | |
1893 | ||
1894 | return rto_time_stamp_us - tcp_sk(sk)->tcp_mstamp; | |
1895 | } | |
1896 | ||
e25f866f CW |
1897 | /* |
1898 | * Save and compile IPv4 options, return a pointer to it | |
1899 | */ | |
91ed1e66 PA |
1900 | static inline struct ip_options_rcu *tcp_v4_save_options(struct net *net, |
1901 | struct sk_buff *skb) | |
e25f866f CW |
1902 | { |
1903 | const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; | |
1904 | struct ip_options_rcu *dopt = NULL; | |
1905 | ||
461b74c3 | 1906 | if (opt->optlen) { |
e25f866f CW |
1907 | int opt_size = sizeof(*dopt) + opt->optlen; |
1908 | ||
1909 | dopt = kmalloc(opt_size, GFP_ATOMIC); | |
91ed1e66 | 1910 | if (dopt && __ip_options_echo(net, &dopt->opt, skb, opt)) { |
e25f866f CW |
1911 | kfree(dopt); |
1912 | dopt = NULL; | |
1913 | } | |
1914 | } | |
1915 | return dopt; | |
1916 | } | |
1917 | ||
98781965 ED |
1918 | /* locally generated TCP pure ACKs have skb->truesize == 2 |
1919 | * (check tcp_send_ack() in net/ipv4/tcp_output.c ) | |
1920 | * This is much faster than dissecting the packet to find out. | |
1921 | * (Think of GRE encapsulations, IPv4, IPv6, ...) | |
1922 | */ | |
1923 | static inline bool skb_is_tcp_pure_ack(const struct sk_buff *skb) | |
1924 | { | |
1925 | return skb->truesize == 2; | |
1926 | } | |
1927 | ||
1928 | static inline void skb_set_tcp_pure_ack(struct sk_buff *skb) | |
1929 | { | |
1930 | skb->truesize = 2; | |
1931 | } | |
1932 | ||
473bd239 TH |
1933 | static inline int tcp_inq(struct sock *sk) |
1934 | { | |
1935 | struct tcp_sock *tp = tcp_sk(sk); | |
1936 | int answ; | |
1937 | ||
1938 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { | |
1939 | answ = 0; | |
1940 | } else if (sock_flag(sk, SOCK_URGINLINE) || | |
1941 | !tp->urg_data || | |
1942 | before(tp->urg_seq, tp->copied_seq) || | |
1943 | !before(tp->urg_seq, tp->rcv_nxt)) { | |
1944 | ||
1945 | answ = tp->rcv_nxt - tp->copied_seq; | |
1946 | ||
1947 | /* Subtract 1, if FIN was received */ | |
1948 | if (answ && sock_flag(sk, SOCK_DONE)) | |
1949 | answ--; | |
1950 | } else { | |
1951 | answ = tp->urg_seq - tp->copied_seq; | |
1952 | } | |
1953 | ||
1954 | return answ; | |
1955 | } | |
1956 | ||
32035585 TH |
1957 | int tcp_peek_len(struct socket *sock); |
1958 | ||
a44d6eac MKL |
1959 | static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) |
1960 | { | |
1961 | u16 segs_in; | |
1962 | ||
1963 | segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); | |
1964 | tp->segs_in += segs_in; | |
1965 | if (skb->len > tcp_hdrlen(skb)) | |
1966 | tp->data_segs_in += segs_in; | |
1967 | } | |
1968 | ||
9caad864 ED |
1969 | /* |
1970 | * TCP listen path runs lockless. | |
1971 | * We forced "struct sock" to be const qualified to make sure | |
1972 | * we don't modify one of its field by mistake. | |
1973 | * Here, we increment sk_drops which is an atomic_t, so we can safely | |
1974 | * make sock writable again. | |
1975 | */ | |
1976 | static inline void tcp_listendrop(const struct sock *sk) | |
1977 | { | |
1978 | atomic_inc(&((struct sock *)sk)->sk_drops); | |
02a1d6e7 | 1979 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); |
9caad864 ED |
1980 | } |
1981 | ||
218af599 ED |
1982 | enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer); |
1983 | ||
734942cc DW |
1984 | /* |
1985 | * Interface for adding Upper Level Protocols over TCP | |
1986 | */ | |
1987 | ||
1988 | #define TCP_ULP_NAME_MAX 16 | |
1989 | #define TCP_ULP_MAX 128 | |
1990 | #define TCP_ULP_BUF_MAX (TCP_ULP_NAME_MAX*TCP_ULP_MAX) | |
1991 | ||
b11a632c JF |
1992 | enum { |
1993 | TCP_ULP_TLS, | |
1aa12bdf | 1994 | TCP_ULP_BPF, |
b11a632c JF |
1995 | }; |
1996 | ||
734942cc DW |
1997 | struct tcp_ulp_ops { |
1998 | struct list_head list; | |
1999 | ||
2000 | /* initialize ulp */ | |
2001 | int (*init)(struct sock *sk); | |
2002 | /* cleanup ulp */ | |
2003 | void (*release)(struct sock *sk); | |
2004 | ||
b11a632c | 2005 | int uid; |
734942cc | 2006 | char name[TCP_ULP_NAME_MAX]; |
b11a632c | 2007 | bool user_visible; |
734942cc DW |
2008 | struct module *owner; |
2009 | }; | |
2010 | int tcp_register_ulp(struct tcp_ulp_ops *type); | |
2011 | void tcp_unregister_ulp(struct tcp_ulp_ops *type); | |
2012 | int tcp_set_ulp(struct sock *sk, const char *name); | |
1aa12bdf | 2013 | int tcp_set_ulp_id(struct sock *sk, const int ulp); |
734942cc DW |
2014 | void tcp_get_available_ulp(char *buf, size_t len); |
2015 | void tcp_cleanup_ulp(struct sock *sk); | |
2016 | ||
40304b2a LB |
2017 | /* Call BPF_SOCK_OPS program that returns an int. If the return value |
2018 | * is < 0, then the BPF op failed (for example if the loaded BPF | |
2019 | * program does not support the chosen operation or there is no BPF | |
2020 | * program loaded). | |
2021 | */ | |
2022 | #ifdef CONFIG_BPF | |
de525be2 | 2023 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
40304b2a LB |
2024 | { |
2025 | struct bpf_sock_ops_kern sock_ops; | |
2026 | int ret; | |
2027 | ||
b73042b8 | 2028 | memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); |
f19397a5 LB |
2029 | if (sk_fullsock(sk)) { |
2030 | sock_ops.is_fullsock = 1; | |
40304b2a | 2031 | sock_owned_by_me(sk); |
f19397a5 | 2032 | } |
40304b2a | 2033 | |
40304b2a LB |
2034 | sock_ops.sk = sk; |
2035 | sock_ops.op = op; | |
de525be2 LB |
2036 | if (nargs > 0) |
2037 | memcpy(sock_ops.args, args, nargs * sizeof(*args)); | |
40304b2a LB |
2038 | |
2039 | ret = BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); | |
2040 | if (ret == 0) | |
2041 | ret = sock_ops.reply; | |
2042 | else | |
2043 | ret = -1; | |
2044 | return ret; | |
2045 | } | |
de525be2 LB |
2046 | |
2047 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) | |
2048 | { | |
2049 | u32 args[2] = {arg1, arg2}; | |
2050 | ||
2051 | return tcp_call_bpf(sk, op, 2, args); | |
2052 | } | |
2053 | ||
2054 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, | |
2055 | u32 arg3) | |
2056 | { | |
2057 | u32 args[3] = {arg1, arg2, arg3}; | |
2058 | ||
2059 | return tcp_call_bpf(sk, op, 3, args); | |
2060 | } | |
2061 | ||
40304b2a | 2062 | #else |
de525be2 | 2063 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
40304b2a LB |
2064 | { |
2065 | return -EPERM; | |
2066 | } | |
de525be2 LB |
2067 | |
2068 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) | |
2069 | { | |
2070 | return -EPERM; | |
2071 | } | |
2072 | ||
2073 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, | |
2074 | u32 arg3) | |
2075 | { | |
2076 | return -EPERM; | |
2077 | } | |
2078 | ||
40304b2a LB |
2079 | #endif |
2080 | ||
8550f328 LB |
2081 | static inline u32 tcp_timeout_init(struct sock *sk) |
2082 | { | |
2083 | int timeout; | |
2084 | ||
de525be2 | 2085 | timeout = tcp_call_bpf(sk, BPF_SOCK_OPS_TIMEOUT_INIT, 0, NULL); |
8550f328 LB |
2086 | |
2087 | if (timeout <= 0) | |
2088 | timeout = TCP_TIMEOUT_INIT; | |
2089 | return timeout; | |
2090 | } | |
2091 | ||
13d3b1eb LB |
2092 | static inline u32 tcp_rwnd_init_bpf(struct sock *sk) |
2093 | { | |
2094 | int rwnd; | |
2095 | ||
de525be2 | 2096 | rwnd = tcp_call_bpf(sk, BPF_SOCK_OPS_RWND_INIT, 0, NULL); |
13d3b1eb LB |
2097 | |
2098 | if (rwnd < 0) | |
2099 | rwnd = 0; | |
2100 | return rwnd; | |
2101 | } | |
91b5b21c LB |
2102 | |
2103 | static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) | |
2104 | { | |
de525be2 | 2105 | return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN, 0, NULL) == 1); |
91b5b21c | 2106 | } |
60e2a778 UB |
2107 | |
2108 | #if IS_ENABLED(CONFIG_SMC) | |
2109 | extern struct static_key_false tcp_have_smc; | |
2110 | #endif | |
6dac1523 IL |
2111 | |
2112 | #if IS_ENABLED(CONFIG_TLS_DEVICE) | |
2113 | void clean_acked_data_enable(struct inet_connection_sock *icsk, | |
2114 | void (*cad)(struct sock *sk, u32 ack_seq)); | |
2115 | void clean_acked_data_disable(struct inet_connection_sock *icsk); | |
2116 | ||
2117 | #endif | |
2118 | ||
1da177e4 | 2119 | #endif /* _TCP_H */ |