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2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
1da177e4 LT |
2 | /* |
3 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
4 | * operating system. INET is implemented using the BSD Socket | |
5 | * interface as the means of communication with the user level. | |
6 | * | |
7 | * Definitions for the TCP module. | |
8 | * | |
9 | * Version: @(#)tcp.h 1.0.5 05/23/93 | |
10 | * | |
02c30a84 | 11 | * Authors: Ross Biro |
1da177e4 | 12 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
1da177e4 LT |
13 | */ |
14 | #ifndef _TCP_H | |
15 | #define _TCP_H | |
16 | ||
1da177e4 LT |
17 | #define FASTRETRANS_DEBUG 1 |
18 | ||
1da177e4 LT |
19 | #include <linux/list.h> |
20 | #include <linux/tcp.h> | |
187f1882 | 21 | #include <linux/bug.h> |
1da177e4 LT |
22 | #include <linux/slab.h> |
23 | #include <linux/cache.h> | |
24 | #include <linux/percpu.h> | |
fb286bb2 | 25 | #include <linux/skbuff.h> |
435cf559 | 26 | #include <linux/kref.h> |
740b0f18 | 27 | #include <linux/ktime.h> |
05e22e83 | 28 | #include <linux/indirect_call_wrapper.h> |
3f421baa ACM |
29 | |
30 | #include <net/inet_connection_sock.h> | |
295ff7ed | 31 | #include <net/inet_timewait_sock.h> |
77d8bf9c | 32 | #include <net/inet_hashtables.h> |
1da177e4 | 33 | #include <net/checksum.h> |
2e6599cb | 34 | #include <net/request_sock.h> |
40a1227e | 35 | #include <net/sock_reuseport.h> |
1da177e4 LT |
36 | #include <net/sock.h> |
37 | #include <net/snmp.h> | |
38 | #include <net/ip.h> | |
c752f073 | 39 | #include <net/tcp_states.h> |
bdf1ee5d | 40 | #include <net/inet_ecn.h> |
0c266898 | 41 | #include <net/dst.h> |
85712484 | 42 | #include <net/mptcp.h> |
c752f073 | 43 | |
1da177e4 | 44 | #include <linux/seq_file.h> |
180d8cd9 | 45 | #include <linux/memcontrol.h> |
40304b2a | 46 | #include <linux/bpf-cgroup.h> |
438ac880 | 47 | #include <linux/siphash.h> |
40304b2a | 48 | |
6e04e021 | 49 | extern struct inet_hashinfo tcp_hashinfo; |
1da177e4 | 50 | |
dd24c001 | 51 | extern struct percpu_counter tcp_orphan_count; |
5c9f3023 | 52 | void tcp_time_wait(struct sock *sk, int state, int timeo); |
1da177e4 | 53 | |
9bacd256 | 54 | #define MAX_TCP_HEADER L1_CACHE_ALIGN(128 + MAX_HEADER) |
33ad798c | 55 | #define MAX_TCP_OPTION_SPACE 40 |
3b4929f6 ED |
56 | #define TCP_MIN_SND_MSS 48 |
57 | #define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE) | |
1da177e4 | 58 | |
105970f6 | 59 | /* |
1da177e4 | 60 | * Never offer a window over 32767 without using window scaling. Some |
105970f6 | 61 | * poor stacks do signed 16bit maths! |
1da177e4 LT |
62 | */ |
63 | #define MAX_TCP_WINDOW 32767U | |
64 | ||
65 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ | |
66 | #define TCP_MIN_MSS 88U | |
67 | ||
1555e6fd | 68 | /* The initial MTU to use for probing */ |
dcd8fb85 | 69 | #define TCP_BASE_MSS 1024 |
5d424d5a | 70 | |
05cbc0db FD |
71 | /* probing interval, default to 10 minutes as per RFC4821 */ |
72 | #define TCP_PROBE_INTERVAL 600 | |
73 | ||
6b58e0a5 FD |
74 | /* Specify interval when tcp mtu probing will stop */ |
75 | #define TCP_PROBE_THRESHOLD 8 | |
76 | ||
1da177e4 LT |
77 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
78 | #define TCP_FASTRETRANS_THRESH 3 | |
79 | ||
1da177e4 LT |
80 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
81 | #define TCP_MAX_QUICKACKS 16U | |
82 | ||
589c49cb GF |
83 | /* Maximal number of window scale according to RFC1323 */ |
84 | #define TCP_MAX_WSCALE 14U | |
85 | ||
1da177e4 LT |
86 | /* urg_data states */ |
87 | #define TCP_URG_VALID 0x0100 | |
88 | #define TCP_URG_NOTYET 0x0200 | |
89 | #define TCP_URG_READ 0x0400 | |
90 | ||
91 | #define TCP_RETR1 3 /* | |
92 | * This is how many retries it does before it | |
93 | * tries to figure out if the gateway is | |
94 | * down. Minimal RFC value is 3; it corresponds | |
95 | * to ~3sec-8min depending on RTO. | |
96 | */ | |
97 | ||
98 | #define TCP_RETR2 15 /* | |
99 | * This should take at least | |
100 | * 90 minutes to time out. | |
101 | * RFC1122 says that the limit is 100 sec. | |
102 | * 15 is ~13-30min depending on RTO. | |
103 | */ | |
104 | ||
6c9ff979 AB |
105 | #define TCP_SYN_RETRIES 6 /* This is how many retries are done |
106 | * when active opening a connection. | |
107 | * RFC1122 says the minimum retry MUST | |
108 | * be at least 180secs. Nevertheless | |
109 | * this value is corresponding to | |
110 | * 63secs of retransmission with the | |
111 | * current initial RTO. | |
112 | */ | |
1da177e4 | 113 | |
6c9ff979 AB |
114 | #define TCP_SYNACK_RETRIES 5 /* This is how may retries are done |
115 | * when passive opening a connection. | |
116 | * This is corresponding to 31secs of | |
117 | * retransmission with the current | |
118 | * initial RTO. | |
119 | */ | |
1da177e4 | 120 | |
1da177e4 LT |
121 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
122 | * state, about 60 seconds */ | |
123 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN | |
124 | /* BSD style FIN_WAIT2 deadlock breaker. | |
125 | * It used to be 3min, new value is 60sec, | |
126 | * to combine FIN-WAIT-2 timeout with | |
127 | * TIME-WAIT timer. | |
128 | */ | |
f0628c52 | 129 | #define TCP_FIN_TIMEOUT_MAX (120 * HZ) /* max TCP_LINGER2 value (two minutes) */ |
1da177e4 LT |
130 | |
131 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ | |
132 | #if HZ >= 100 | |
133 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ | |
134 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) | |
135 | #else | |
136 | #define TCP_DELACK_MIN 4U | |
137 | #define TCP_ATO_MIN 4U | |
138 | #endif | |
139 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) | |
140 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) | |
bb4d991a | 141 | #define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ |
fd4f2cea | 142 | #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ |
9ad7c049 JC |
143 | #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now |
144 | * used as a fallback RTO for the | |
145 | * initial data transmission if no | |
146 | * valid RTT sample has been acquired, | |
147 | * most likely due to retrans in 3WHS. | |
148 | */ | |
1da177e4 LT |
149 | |
150 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes | |
151 | * for local resources. | |
152 | */ | |
1da177e4 LT |
153 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
154 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ | |
155 | #define TCP_KEEPALIVE_INTVL (75*HZ) | |
156 | ||
157 | #define MAX_TCP_KEEPIDLE 32767 | |
158 | #define MAX_TCP_KEEPINTVL 32767 | |
159 | #define MAX_TCP_KEEPCNT 127 | |
160 | #define MAX_TCP_SYNCNT 127 | |
161 | ||
162 | #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ | |
1da177e4 LT |
163 | |
164 | #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) | |
165 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated | |
166 | * after this time. It should be equal | |
167 | * (or greater than) TCP_TIMEWAIT_LEN | |
168 | * to provide reliability equal to one | |
169 | * provided by timewait state. | |
170 | */ | |
171 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host | |
172 | * timestamps. It must be less than | |
173 | * minimal timewait lifetime. | |
174 | */ | |
1da177e4 LT |
175 | /* |
176 | * TCP option | |
177 | */ | |
105970f6 | 178 | |
1da177e4 LT |
179 | #define TCPOPT_NOP 1 /* Padding */ |
180 | #define TCPOPT_EOL 0 /* End of options */ | |
181 | #define TCPOPT_MSS 2 /* Segment size negotiating */ | |
182 | #define TCPOPT_WINDOW 3 /* Window scaling */ | |
183 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ | |
184 | #define TCPOPT_SACK 5 /* SACK Block */ | |
185 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ | |
cfb6eeb4 | 186 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
c74a39c8 | 187 | #define TCPOPT_MPTCP 30 /* Multipath TCP (RFC6824) */ |
7f9b838b | 188 | #define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ |
2100c8d2 YC |
189 | #define TCPOPT_EXP 254 /* Experimental */ |
190 | /* Magic number to be after the option value for sharing TCP | |
191 | * experimental options. See draft-ietf-tcpm-experimental-options-00.txt | |
192 | */ | |
193 | #define TCPOPT_FASTOPEN_MAGIC 0xF989 | |
60e2a778 | 194 | #define TCPOPT_SMC_MAGIC 0xE2D4C3D9 |
1da177e4 LT |
195 | |
196 | /* | |
197 | * TCP option lengths | |
198 | */ | |
199 | ||
200 | #define TCPOLEN_MSS 4 | |
201 | #define TCPOLEN_WINDOW 3 | |
202 | #define TCPOLEN_SACK_PERM 2 | |
203 | #define TCPOLEN_TIMESTAMP 10 | |
cfb6eeb4 | 204 | #define TCPOLEN_MD5SIG 18 |
7f9b838b | 205 | #define TCPOLEN_FASTOPEN_BASE 2 |
2100c8d2 | 206 | #define TCPOLEN_EXP_FASTOPEN_BASE 4 |
60e2a778 | 207 | #define TCPOLEN_EXP_SMC_BASE 6 |
1da177e4 LT |
208 | |
209 | /* But this is what stacks really send out. */ | |
210 | #define TCPOLEN_TSTAMP_ALIGNED 12 | |
211 | #define TCPOLEN_WSCALE_ALIGNED 4 | |
212 | #define TCPOLEN_SACKPERM_ALIGNED 4 | |
213 | #define TCPOLEN_SACK_BASE 2 | |
214 | #define TCPOLEN_SACK_BASE_ALIGNED 4 | |
215 | #define TCPOLEN_SACK_PERBLOCK 8 | |
cfb6eeb4 | 216 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
33ad798c | 217 | #define TCPOLEN_MSS_ALIGNED 4 |
60e2a778 | 218 | #define TCPOLEN_EXP_SMC_BASE_ALIGNED 8 |
1da177e4 | 219 | |
1da177e4 LT |
220 | /* Flags in tp->nonagle */ |
221 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ | |
222 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ | |
caa20d9a | 223 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
1da177e4 | 224 | |
36e31b0a AP |
225 | /* TCP thin-stream limits */ |
226 | #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ | |
227 | ||
21603fc4 | 228 | /* TCP initial congestion window as per rfc6928 */ |
442b9635 DM |
229 | #define TCP_INIT_CWND 10 |
230 | ||
cf60af03 YC |
231 | /* Bit Flags for sysctl_tcp_fastopen */ |
232 | #define TFO_CLIENT_ENABLE 1 | |
10467163 | 233 | #define TFO_SERVER_ENABLE 2 |
67da22d2 | 234 | #define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ |
cf60af03 | 235 | |
10467163 JC |
236 | /* Accept SYN data w/o any cookie option */ |
237 | #define TFO_SERVER_COOKIE_NOT_REQD 0x200 | |
238 | ||
239 | /* Force enable TFO on all listeners, i.e., not requiring the | |
cebc5cba | 240 | * TCP_FASTOPEN socket option. |
10467163 JC |
241 | */ |
242 | #define TFO_SERVER_WO_SOCKOPT1 0x400 | |
10467163 | 243 | |
295ff7ed | 244 | |
1da177e4 | 245 | /* sysctl variables for tcp */ |
1da177e4 | 246 | extern int sysctl_tcp_max_orphans; |
a4fe34bf | 247 | extern long sysctl_tcp_mem[3]; |
e20223f1 | 248 | |
a0370b3f | 249 | #define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ |
1f255691 | 250 | #define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */ |
20b654df | 251 | #define TCP_RACK_NO_DUPTHRESH 0x4 /* Do not use DUPACK threshold in RACK */ |
a0370b3f | 252 | |
8d987e5c | 253 | extern atomic_long_t tcp_memory_allocated; |
1748376b | 254 | extern struct percpu_counter tcp_sockets_allocated; |
06044751 | 255 | extern unsigned long tcp_memory_pressure; |
1da177e4 | 256 | |
b8da51eb ED |
257 | /* optimized version of sk_under_memory_pressure() for TCP sockets */ |
258 | static inline bool tcp_under_memory_pressure(const struct sock *sk) | |
259 | { | |
baac50bb JW |
260 | if (mem_cgroup_sockets_enabled && sk->sk_memcg && |
261 | mem_cgroup_under_socket_pressure(sk->sk_memcg)) | |
e805605c | 262 | return true; |
b8da51eb | 263 | |
1f142c17 | 264 | return READ_ONCE(tcp_memory_pressure); |
b8da51eb | 265 | } |
1da177e4 LT |
266 | /* |
267 | * The next routines deal with comparing 32 bit unsigned ints | |
268 | * and worry about wraparound (automatic with unsigned arithmetic). | |
269 | */ | |
270 | ||
a2a385d6 | 271 | static inline bool before(__u32 seq1, __u32 seq2) |
1da177e4 | 272 | { |
0d630cc0 | 273 | return (__s32)(seq1-seq2) < 0; |
1da177e4 | 274 | } |
9a036b9c | 275 | #define after(seq2, seq1) before(seq1, seq2) |
1da177e4 LT |
276 | |
277 | /* is s2<=s1<=s3 ? */ | |
a2a385d6 | 278 | static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) |
1da177e4 LT |
279 | { |
280 | return seq3 - seq2 >= seq1 - seq2; | |
281 | } | |
282 | ||
efcdbf24 AS |
283 | static inline bool tcp_out_of_memory(struct sock *sk) |
284 | { | |
285 | if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && | |
286 | sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2)) | |
287 | return true; | |
288 | return false; | |
289 | } | |
290 | ||
a6c5ea4c ED |
291 | void sk_forced_mem_schedule(struct sock *sk, int size); |
292 | ||
ad1af0fe | 293 | static inline bool tcp_too_many_orphans(struct sock *sk, int shift) |
e4fd5da3 | 294 | { |
ad1af0fe DM |
295 | struct percpu_counter *ocp = sk->sk_prot->orphan_count; |
296 | int orphans = percpu_counter_read_positive(ocp); | |
297 | ||
298 | if (orphans << shift > sysctl_tcp_max_orphans) { | |
299 | orphans = percpu_counter_sum_positive(ocp); | |
300 | if (orphans << shift > sysctl_tcp_max_orphans) | |
301 | return true; | |
302 | } | |
ad1af0fe | 303 | return false; |
e4fd5da3 | 304 | } |
1da177e4 | 305 | |
5c9f3023 | 306 | bool tcp_check_oom(struct sock *sk, int shift); |
efcdbf24 | 307 | |
a0f82f64 | 308 | |
1da177e4 LT |
309 | extern struct proto tcp_prot; |
310 | ||
57ef42d5 | 311 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
13415e46 | 312 | #define __TCP_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
57ef42d5 | 313 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) |
aa2ea058 | 314 | #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) |
1da177e4 | 315 | |
5c9f3023 JP |
316 | void tcp_tasklet_init(void); |
317 | ||
32bbd879 | 318 | int tcp_v4_err(struct sk_buff *skb, u32); |
5c9f3023 JP |
319 | |
320 | void tcp_shutdown(struct sock *sk, int how); | |
321 | ||
7487449c | 322 | int tcp_v4_early_demux(struct sk_buff *skb); |
5c9f3023 JP |
323 | int tcp_v4_rcv(struct sk_buff *skb); |
324 | ||
b796d04b | 325 | void tcp_remove_empty_skb(struct sock *sk, struct sk_buff *skb); |
5c9f3023 | 326 | int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); |
1b784140 | 327 | int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); |
306b13eb | 328 | int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size); |
5c9f3023 JP |
329 | int tcp_sendpage(struct sock *sk, struct page *page, int offset, size_t size, |
330 | int flags); | |
306b13eb TH |
331 | int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset, |
332 | size_t size, int flags); | |
b796d04b PA |
333 | struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags, |
334 | struct page *page, int offset, size_t *size); | |
e3b5616a DW |
335 | ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, |
336 | size_t size, int flags); | |
35b2c321 MM |
337 | int tcp_send_mss(struct sock *sk, int *size_goal, int flags); |
338 | void tcp_push(struct sock *sk, int flags, int mss_now, int nonagle, | |
339 | int size_goal); | |
5c9f3023 JP |
340 | void tcp_release_cb(struct sock *sk); |
341 | void tcp_wfree(struct sk_buff *skb); | |
342 | void tcp_write_timer_handler(struct sock *sk); | |
343 | void tcp_delack_timer_handler(struct sock *sk); | |
344 | int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg); | |
72ab4a86 | 345 | int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); |
3d97d88e | 346 | void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); |
5c9f3023 | 347 | void tcp_rcv_space_adjust(struct sock *sk); |
5c9f3023 JP |
348 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); |
349 | void tcp_twsk_destructor(struct sock *sk); | |
350 | ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, | |
351 | struct pipe_inode_info *pipe, size_t len, | |
352 | unsigned int flags); | |
9c55e01c | 353 | |
a0496ef2 | 354 | void tcp_enter_quickack_mode(struct sock *sk, unsigned int max_quickacks); |
463c84b9 ACM |
355 | static inline void tcp_dec_quickack_mode(struct sock *sk, |
356 | const unsigned int pkts) | |
1da177e4 | 357 | { |
463c84b9 | 358 | struct inet_connection_sock *icsk = inet_csk(sk); |
fc6415bc | 359 | |
463c84b9 ACM |
360 | if (icsk->icsk_ack.quick) { |
361 | if (pkts >= icsk->icsk_ack.quick) { | |
362 | icsk->icsk_ack.quick = 0; | |
fc6415bc | 363 | /* Leaving quickack mode we deflate ATO. */ |
463c84b9 | 364 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
fc6415bc | 365 | } else |
463c84b9 | 366 | icsk->icsk_ack.quick -= pkts; |
1da177e4 LT |
367 | } |
368 | } | |
369 | ||
bdf1ee5d IJ |
370 | #define TCP_ECN_OK 1 |
371 | #define TCP_ECN_QUEUE_CWR 2 | |
372 | #define TCP_ECN_DEMAND_CWR 4 | |
7a269ffa | 373 | #define TCP_ECN_SEEN 8 |
bdf1ee5d | 374 | |
fd2c3ef7 | 375 | enum tcp_tw_status { |
1da177e4 LT |
376 | TCP_TW_SUCCESS = 0, |
377 | TCP_TW_RST = 1, | |
378 | TCP_TW_ACK = 2, | |
379 | TCP_TW_SYN = 3 | |
380 | }; | |
381 | ||
382 | ||
5c9f3023 JP |
383 | enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
384 | struct sk_buff *skb, | |
385 | const struct tcphdr *th); | |
386 | struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, | |
e0f9759f ED |
387 | struct request_sock *req, bool fastopen, |
388 | bool *lost_race); | |
5c9f3023 JP |
389 | int tcp_child_process(struct sock *parent, struct sock *child, |
390 | struct sk_buff *skb); | |
5ae344c9 | 391 | void tcp_enter_loss(struct sock *sk); |
7e901ee7 | 392 | void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int newly_lost, int flag); |
5c9f3023 JP |
393 | void tcp_clear_retrans(struct tcp_sock *tp); |
394 | void tcp_update_metrics(struct sock *sk); | |
395 | void tcp_init_metrics(struct sock *sk); | |
396 | void tcp_metrics_init(void); | |
d82bae12 | 397 | bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst); |
77c3c956 | 398 | void __tcp_close(struct sock *sk, long timeout); |
5c9f3023 JP |
399 | void tcp_close(struct sock *sk, long timeout); |
400 | void tcp_init_sock(struct sock *sk); | |
72be0fe6 | 401 | void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb); |
a11e1d43 LT |
402 | __poll_t tcp_poll(struct file *file, struct socket *sock, |
403 | struct poll_table_struct *wait); | |
5c9f3023 JP |
404 | int tcp_getsockopt(struct sock *sk, int level, int optname, |
405 | char __user *optval, int __user *optlen); | |
9cacf81f | 406 | bool tcp_bpf_bypass_getsockopt(int level, int optname); |
a7b75c5a CH |
407 | int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, |
408 | unsigned int optlen); | |
5c9f3023 | 409 | void tcp_set_keepalive(struct sock *sk, int val); |
42cb80a2 | 410 | void tcp_syn_ack_timeout(const struct request_sock *req); |
1b784140 YX |
411 | int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, |
412 | int flags, int *addr_len); | |
d1361840 | 413 | int tcp_set_rcvlowat(struct sock *sk, int val); |
cb811109 | 414 | int tcp_set_window_clamp(struct sock *sk, int val); |
03f45c88 | 415 | void tcp_data_ready(struct sock *sk); |
340a6f3d | 416 | #ifdef CONFIG_MMU |
93ab6cc6 ED |
417 | int tcp_mmap(struct file *file, struct socket *sock, |
418 | struct vm_area_struct *vma); | |
340a6f3d | 419 | #endif |
eed29f17 | 420 | void tcp_parse_options(const struct net *net, const struct sk_buff *skb, |
5c9f3023 JP |
421 | struct tcp_options_received *opt_rx, |
422 | int estab, struct tcp_fastopen_cookie *foc); | |
423 | const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); | |
7d5d5525 | 424 | |
9349d600 PP |
425 | /* |
426 | * BPF SKB-less helpers | |
427 | */ | |
428 | u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, | |
429 | struct tcphdr *th, u32 *cookie); | |
430 | u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, | |
431 | struct tcphdr *th, u32 *cookie); | |
432 | u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, | |
433 | const struct tcp_request_sock_ops *af_ops, | |
434 | struct sock *sk, struct tcphdr *th); | |
1da177e4 LT |
435 | /* |
436 | * TCP v4 functions exported for the inet6 API | |
437 | */ | |
438 | ||
5c9f3023 | 439 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
4fab9071 | 440 | void tcp_v4_mtu_reduced(struct sock *sk); |
9cf74903 | 441 | void tcp_req_err(struct sock *sk, u32 seq, bool abort); |
d2924569 | 442 | void tcp_ld_RTO_revert(struct sock *sk, u32 seq); |
5c9f3023 | 443 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); |
c28c6f04 | 444 | struct sock *tcp_create_openreq_child(const struct sock *sk, |
5c9f3023 JP |
445 | struct request_sock *req, |
446 | struct sk_buff *skb); | |
81164413 | 447 | void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); |
0c27171e | 448 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
5c9f3023 | 449 | struct request_sock *req, |
5e0724d0 ED |
450 | struct dst_entry *dst, |
451 | struct request_sock *req_unhash, | |
452 | bool *own_req); | |
5c9f3023 JP |
453 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); |
454 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); | |
455 | int tcp_connect(struct sock *sk); | |
b3d05147 ED |
456 | enum tcp_synack_type { |
457 | TCP_SYNACK_NORMAL, | |
458 | TCP_SYNACK_FASTOPEN, | |
459 | TCP_SYNACK_COOKIE, | |
460 | }; | |
5d062de7 | 461 | struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, |
5c9f3023 | 462 | struct request_sock *req, |
ca6fb065 | 463 | struct tcp_fastopen_cookie *foc, |
331fca43 MKL |
464 | enum tcp_synack_type synack_type, |
465 | struct sk_buff *syn_skb); | |
5c9f3023 | 466 | int tcp_disconnect(struct sock *sk, int flags); |
1da177e4 | 467 | |
370816ae | 468 | void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); |
292e8d8c | 469 | int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); |
63d02d15 | 470 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); |
1da177e4 | 471 | |
1da177e4 | 472 | /* From syncookies.c */ |
b80c0e78 ED |
473 | struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, |
474 | struct request_sock *req, | |
84b114b9 | 475 | struct dst_entry *dst, u32 tsoff); |
5c9f3023 JP |
476 | int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, |
477 | u32 cookie); | |
461b74c3 | 478 | struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); |
6fc8c827 FW |
479 | struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, |
480 | struct sock *sk, struct sk_buff *skb); | |
e05c82d3 | 481 | #ifdef CONFIG_SYN_COOKIES |
8c27bd75 | 482 | |
63262315 | 483 | /* Syncookies use a monotonic timer which increments every 60 seconds. |
8c27bd75 FW |
484 | * This counter is used both as a hash input and partially encoded into |
485 | * the cookie value. A cookie is only validated further if the delta | |
486 | * between the current counter value and the encoded one is less than this, | |
63262315 | 487 | * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if |
8c27bd75 FW |
488 | * the counter advances immediately after a cookie is generated). |
489 | */ | |
264ea103 ED |
490 | #define MAX_SYNCOOKIE_AGE 2 |
491 | #define TCP_SYNCOOKIE_PERIOD (60 * HZ) | |
492 | #define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) | |
493 | ||
494 | /* syncookies: remember time of last synqueue overflow | |
495 | * But do not dirty this field too often (once per second is enough) | |
3f684b4b | 496 | * It is racy as we do not hold a lock, but race is very minor. |
264ea103 | 497 | */ |
3f684b4b | 498 | static inline void tcp_synq_overflow(const struct sock *sk) |
264ea103 | 499 | { |
40a1227e | 500 | unsigned int last_overflow; |
cca9bab1 | 501 | unsigned int now = jiffies; |
264ea103 | 502 | |
40a1227e MKL |
503 | if (sk->sk_reuseport) { |
504 | struct sock_reuseport *reuse; | |
505 | ||
506 | reuse = rcu_dereference(sk->sk_reuseport_cb); | |
507 | if (likely(reuse)) { | |
508 | last_overflow = READ_ONCE(reuse->synq_overflow_ts); | |
04d26e7b GN |
509 | if (!time_between32(now, last_overflow, |
510 | last_overflow + HZ)) | |
40a1227e MKL |
511 | WRITE_ONCE(reuse->synq_overflow_ts, now); |
512 | return; | |
513 | } | |
514 | } | |
515 | ||
721c8daf | 516 | last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); |
04d26e7b | 517 | if (!time_between32(now, last_overflow, last_overflow + HZ)) |
721c8daf | 518 | WRITE_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp, now); |
264ea103 ED |
519 | } |
520 | ||
521 | /* syncookies: no recent synqueue overflow on this listening socket? */ | |
522 | static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) | |
523 | { | |
40a1227e | 524 | unsigned int last_overflow; |
cca9bab1 | 525 | unsigned int now = jiffies; |
264ea103 | 526 | |
40a1227e MKL |
527 | if (sk->sk_reuseport) { |
528 | struct sock_reuseport *reuse; | |
529 | ||
530 | reuse = rcu_dereference(sk->sk_reuseport_cb); | |
531 | if (likely(reuse)) { | |
532 | last_overflow = READ_ONCE(reuse->synq_overflow_ts); | |
cb44a08f GN |
533 | return !time_between32(now, last_overflow - HZ, |
534 | last_overflow + | |
535 | TCP_SYNCOOKIE_VALID); | |
40a1227e MKL |
536 | } |
537 | } | |
538 | ||
721c8daf | 539 | last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); |
cb44a08f GN |
540 | |
541 | /* If last_overflow <= jiffies <= last_overflow + TCP_SYNCOOKIE_VALID, | |
542 | * then we're under synflood. However, we have to use | |
543 | * 'last_overflow - HZ' as lower bound. That's because a concurrent | |
544 | * tcp_synq_overflow() could update .ts_recent_stamp after we read | |
545 | * jiffies but before we store .ts_recent_stamp into last_overflow, | |
546 | * which could lead to rejecting a valid syncookie. | |
547 | */ | |
548 | return !time_between32(now, last_overflow - HZ, | |
549 | last_overflow + TCP_SYNCOOKIE_VALID); | |
264ea103 | 550 | } |
8c27bd75 FW |
551 | |
552 | static inline u32 tcp_cookie_time(void) | |
553 | { | |
63262315 ED |
554 | u64 val = get_jiffies_64(); |
555 | ||
264ea103 | 556 | do_div(val, TCP_SYNCOOKIE_PERIOD); |
63262315 | 557 | return val; |
8c27bd75 FW |
558 | } |
559 | ||
5c9f3023 JP |
560 | u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, |
561 | u16 *mssp); | |
3f684b4b | 562 | __u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); |
200ecef6 | 563 | u64 cookie_init_timestamp(struct request_sock *req, u64 now); |
f9301034 ED |
564 | bool cookie_timestamp_decode(const struct net *net, |
565 | struct tcp_options_received *opt); | |
f1673381 | 566 | bool cookie_ecn_ok(const struct tcp_options_received *opt, |
f7b3bec6 | 567 | const struct net *net, const struct dst_entry *dst); |
4dfc2817 | 568 | |
c6aefafb | 569 | /* From net/ipv6/syncookies.c */ |
5c9f3023 JP |
570 | int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, |
571 | u32 cookie); | |
572 | struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); | |
f1673381 | 573 | |
5c9f3023 JP |
574 | u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, |
575 | const struct tcphdr *th, u16 *mssp); | |
3f684b4b | 576 | __u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); |
e05c82d3 | 577 | #endif |
1da177e4 LT |
578 | /* tcp_output.c */ |
579 | ||
5c9f3023 JP |
580 | void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
581 | int nonagle); | |
10d3be56 ED |
582 | int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
583 | int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); | |
5c9f3023 JP |
584 | void tcp_retransmit_timer(struct sock *sk); |
585 | void tcp_xmit_retransmit_queue(struct sock *); | |
586 | void tcp_simple_retransmit(struct sock *); | |
57dde7f7 | 587 | void tcp_enter_recovery(struct sock *sk, bool ece_ack); |
5c9f3023 | 588 | int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
75c119af ED |
589 | enum tcp_queue { |
590 | TCP_FRAG_IN_WRITE_QUEUE, | |
591 | TCP_FRAG_IN_RTX_QUEUE, | |
592 | }; | |
593 | int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, | |
594 | struct sk_buff *skb, u32 len, | |
595 | unsigned int mss_now, gfp_t gfp); | |
5c9f3023 JP |
596 | |
597 | void tcp_send_probe0(struct sock *); | |
598 | void tcp_send_partial(struct sock *); | |
e520af48 | 599 | int tcp_write_wakeup(struct sock *, int mib); |
5c9f3023 JP |
600 | void tcp_send_fin(struct sock *sk); |
601 | void tcp_send_active_reset(struct sock *sk, gfp_t priority); | |
602 | int tcp_send_synack(struct sock *); | |
5c9f3023 | 603 | void tcp_push_one(struct sock *, unsigned int mss_now); |
27cde44a | 604 | void __tcp_send_ack(struct sock *sk, u32 rcv_nxt); |
5c9f3023 JP |
605 | void tcp_send_ack(struct sock *sk); |
606 | void tcp_send_delayed_ack(struct sock *sk); | |
607 | void tcp_send_loss_probe(struct sock *sk); | |
ed66dfaf | 608 | bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto); |
cfea5a68 MKL |
609 | void tcp_skb_collapse_tstamp(struct sk_buff *skb, |
610 | const struct sk_buff *next_skb); | |
1da177e4 | 611 | |
a762a980 | 612 | /* tcp_input.c */ |
5c9f3023 | 613 | void tcp_rearm_rto(struct sock *sk); |
0f1c28ae | 614 | void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); |
049fe386 | 615 | void tcp_reset(struct sock *sk, struct sk_buff *skb); |
4f41b1c5 | 616 | void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb); |
e3e17b77 | 617 | void tcp_fin(struct sock *sk); |
a762a980 | 618 | |
1da177e4 | 619 | /* tcp_timer.c */ |
5c9f3023 | 620 | void tcp_init_xmit_timers(struct sock *); |
463c84b9 ACM |
621 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
622 | { | |
73a6bab5 | 623 | if (hrtimer_try_to_cancel(&tcp_sk(sk)->pacing_timer) == 1) |
cf0dd203 | 624 | __sock_put(sk); |
73a6bab5 | 625 | |
5d9f4262 ED |
626 | if (hrtimer_try_to_cancel(&tcp_sk(sk)->compressed_ack_timer) == 1) |
627 | __sock_put(sk); | |
628 | ||
463c84b9 ACM |
629 | inet_csk_clear_xmit_timers(sk); |
630 | } | |
1da177e4 | 631 | |
5c9f3023 JP |
632 | unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
633 | unsigned int tcp_current_mss(struct sock *sk); | |
344db93a | 634 | u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when); |
0c54b85f IJ |
635 | |
636 | /* Bound MSS / TSO packet size with the half of the window */ | |
637 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) | |
638 | { | |
01f83d69 AK |
639 | int cutoff; |
640 | ||
641 | /* When peer uses tiny windows, there is no use in packetizing | |
642 | * to sub-MSS pieces for the sake of SWS or making sure there | |
643 | * are enough packets in the pipe for fast recovery. | |
644 | * | |
645 | * On the other hand, for extremely large MSS devices, handling | |
646 | * smaller than MSS windows in this way does make sense. | |
647 | */ | |
2631b79f | 648 | if (tp->max_window > TCP_MSS_DEFAULT) |
01f83d69 AK |
649 | cutoff = (tp->max_window >> 1); |
650 | else | |
651 | cutoff = tp->max_window; | |
652 | ||
653 | if (cutoff && pktsize > cutoff) | |
654 | return max_t(int, cutoff, 68U - tp->tcp_header_len); | |
0c54b85f IJ |
655 | else |
656 | return pktsize; | |
657 | } | |
1da177e4 | 658 | |
17b085ea | 659 | /* tcp.c */ |
0df48c26 | 660 | void tcp_get_info(struct sock *, struct tcp_info *); |
1da177e4 LT |
661 | |
662 | /* Read 'sendfile()'-style from a TCP socket */ | |
5c9f3023 JP |
663 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
664 | sk_read_actor_t recv_actor); | |
1da177e4 | 665 | |
5c9f3023 | 666 | void tcp_initialize_rcv_mss(struct sock *sk); |
1da177e4 | 667 | |
5c9f3023 JP |
668 | int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
669 | int tcp_mss_to_mtu(struct sock *sk, int mss); | |
670 | void tcp_mtup_init(struct sock *sk); | |
5d424d5a | 671 | |
f1ecd5d9 DL |
672 | static inline void tcp_bound_rto(const struct sock *sk) |
673 | { | |
674 | if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) | |
675 | inet_csk(sk)->icsk_rto = TCP_RTO_MAX; | |
676 | } | |
677 | ||
678 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) | |
679 | { | |
740b0f18 | 680 | return usecs_to_jiffies((tp->srtt_us >> 3) + tp->rttvar_us); |
f1ecd5d9 DL |
681 | } |
682 | ||
31770e34 FW |
683 | static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
684 | { | |
685 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | | |
686 | ntohl(TCP_FLAG_ACK) | | |
687 | snd_wnd); | |
688 | } | |
689 | ||
690 | static inline void tcp_fast_path_on(struct tcp_sock *tp) | |
691 | { | |
692 | __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); | |
693 | } | |
694 | ||
695 | static inline void tcp_fast_path_check(struct sock *sk) | |
696 | { | |
697 | struct tcp_sock *tp = tcp_sk(sk); | |
698 | ||
699 | if (RB_EMPTY_ROOT(&tp->out_of_order_queue) && | |
700 | tp->rcv_wnd && | |
701 | atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && | |
702 | !tp->urg_data) | |
703 | tcp_fast_path_on(tp); | |
704 | } | |
705 | ||
0c266898 SS |
706 | /* Compute the actual rto_min value */ |
707 | static inline u32 tcp_rto_min(struct sock *sk) | |
708 | { | |
cf533ea5 | 709 | const struct dst_entry *dst = __sk_dst_get(sk); |
ca584ba0 | 710 | u32 rto_min = inet_csk(sk)->icsk_rto_min; |
0c266898 SS |
711 | |
712 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) | |
713 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); | |
714 | return rto_min; | |
715 | } | |
716 | ||
740b0f18 ED |
717 | static inline u32 tcp_rto_min_us(struct sock *sk) |
718 | { | |
719 | return jiffies_to_usecs(tcp_rto_min(sk)); | |
720 | } | |
721 | ||
81164413 DB |
722 | static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) |
723 | { | |
724 | return dst_metric_locked(dst, RTAX_CC_ALGO); | |
725 | } | |
726 | ||
f6722583 YC |
727 | /* Minimum RTT in usec. ~0 means not available. */ |
728 | static inline u32 tcp_min_rtt(const struct tcp_sock *tp) | |
729 | { | |
64033892 | 730 | return minmax_get(&tp->rtt_min); |
f6722583 YC |
731 | } |
732 | ||
1da177e4 LT |
733 | /* Compute the actual receive window we are currently advertising. |
734 | * Rcv_nxt can be after the window if our peer push more data | |
735 | * than the offered window. | |
736 | */ | |
40efc6fa | 737 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
1da177e4 LT |
738 | { |
739 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; | |
740 | ||
741 | if (win < 0) | |
742 | win = 0; | |
743 | return (u32) win; | |
744 | } | |
745 | ||
746 | /* Choose a new window, without checks for shrinking, and without | |
747 | * scaling applied to the result. The caller does these things | |
748 | * if necessary. This is a "raw" window selection. | |
749 | */ | |
5c9f3023 | 750 | u32 __tcp_select_window(struct sock *sk); |
1da177e4 | 751 | |
ee995283 PE |
752 | void tcp_send_window_probe(struct sock *sk); |
753 | ||
ec66eda8 ED |
754 | /* TCP uses 32bit jiffies to save some space. |
755 | * Note that this is different from tcp_time_stamp, which | |
756 | * historically has been the same until linux-4.13. | |
757 | */ | |
758 | #define tcp_jiffies32 ((u32)jiffies) | |
759 | ||
9a568de4 ED |
760 | /* |
761 | * Deliver a 32bit value for TCP timestamp option (RFC 7323) | |
762 | * It is no longer tied to jiffies, but to 1 ms clock. | |
763 | * Note: double check if you want to use tcp_jiffies32 instead of this. | |
764 | */ | |
765 | #define TCP_TS_HZ 1000 | |
766 | ||
767 | static inline u64 tcp_clock_ns(void) | |
768 | { | |
fb420d5d | 769 | return ktime_get_ns(); |
9a568de4 ED |
770 | } |
771 | ||
772 | static inline u64 tcp_clock_us(void) | |
773 | { | |
774 | return div_u64(tcp_clock_ns(), NSEC_PER_USEC); | |
775 | } | |
776 | ||
777 | /* This should only be used in contexts where tp->tcp_mstamp is up to date */ | |
778 | static inline u32 tcp_time_stamp(const struct tcp_sock *tp) | |
779 | { | |
780 | return div_u64(tp->tcp_mstamp, USEC_PER_SEC / TCP_TS_HZ); | |
781 | } | |
782 | ||
200ecef6 ED |
783 | /* Convert a nsec timestamp into TCP TSval timestamp (ms based currently) */ |
784 | static inline u32 tcp_ns_to_ts(u64 ns) | |
785 | { | |
786 | return div_u64(ns, NSEC_PER_SEC / TCP_TS_HZ); | |
787 | } | |
788 | ||
9a568de4 ED |
789 | /* Could use tcp_clock_us() / 1000, but this version uses a single divide */ |
790 | static inline u32 tcp_time_stamp_raw(void) | |
791 | { | |
200ecef6 | 792 | return tcp_ns_to_ts(tcp_clock_ns()); |
9a568de4 ED |
793 | } |
794 | ||
9799ccb0 | 795 | void tcp_mstamp_refresh(struct tcp_sock *tp); |
9a568de4 ED |
796 | |
797 | static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) | |
798 | { | |
799 | return max_t(s64, t1 - t0, 0); | |
800 | } | |
1da177e4 | 801 | |
7faee5c0 ED |
802 | static inline u32 tcp_skb_timestamp(const struct sk_buff *skb) |
803 | { | |
200ecef6 | 804 | return tcp_ns_to_ts(skb->skb_mstamp_ns); |
7faee5c0 ED |
805 | } |
806 | ||
2fd66ffb ED |
807 | /* provide the departure time in us unit */ |
808 | static inline u64 tcp_skb_timestamp_us(const struct sk_buff *skb) | |
809 | { | |
d3edd06e | 810 | return div_u64(skb->skb_mstamp_ns, NSEC_PER_USEC); |
2fd66ffb ED |
811 | } |
812 | ||
7faee5c0 | 813 | |
a3433f35 CG |
814 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
815 | ||
816 | #define TCPHDR_FIN 0x01 | |
817 | #define TCPHDR_SYN 0x02 | |
818 | #define TCPHDR_RST 0x04 | |
819 | #define TCPHDR_PSH 0x08 | |
820 | #define TCPHDR_ACK 0x10 | |
821 | #define TCPHDR_URG 0x20 | |
822 | #define TCPHDR_ECE 0x40 | |
823 | #define TCPHDR_CWR 0x80 | |
824 | ||
49213555 DB |
825 | #define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) |
826 | ||
caa20d9a | 827 | /* This is what the send packet queuing engine uses to pass |
f86586fa ED |
828 | * TCP per-packet control information to the transmission code. |
829 | * We also store the host-order sequence numbers in here too. | |
830 | * This is 44 bytes if IPV6 is enabled. | |
831 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. | |
1da177e4 LT |
832 | */ |
833 | struct tcp_skb_cb { | |
1da177e4 LT |
834 | __u32 seq; /* Starting sequence number */ |
835 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ | |
cd7d8498 ED |
836 | union { |
837 | /* Note : tcp_tw_isn is used in input path only | |
838 | * (isn chosen by tcp_timewait_state_process()) | |
839 | * | |
f69ad292 ED |
840 | * tcp_gso_segs/size are used in write queue only, |
841 | * cf tcp_skb_pcount()/tcp_skb_mss() | |
cd7d8498 ED |
842 | */ |
843 | __u32 tcp_tw_isn; | |
f69ad292 ED |
844 | struct { |
845 | u16 tcp_gso_segs; | |
846 | u16 tcp_gso_size; | |
847 | }; | |
cd7d8498 | 848 | }; |
4de075e0 | 849 | __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ |
f4f9f6e7 | 850 | |
713bafea | 851 | __u8 sacked; /* State flags for SACK. */ |
1da177e4 LT |
852 | #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ |
853 | #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ | |
854 | #define TCPCB_LOST 0x04 /* SKB is lost */ | |
855 | #define TCPCB_TAGBITS 0x07 /* All tag bits */ | |
d3edd06e | 856 | #define TCPCB_REPAIRED 0x10 /* SKB repaired (no skb_mstamp_ns) */ |
1da177e4 | 857 | #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ |
9d186cac AV |
858 | #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS| \ |
859 | TCPCB_REPAIRED) | |
1da177e4 | 860 | |
f4f9f6e7 | 861 | __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ |
6b084928 | 862 | __u8 txstamp_ack:1, /* Record TX timestamp for ack? */ |
c134ecb8 | 863 | eor:1, /* Is skb MSG_EOR marked? */ |
98aaa913 MM |
864 | has_rxtstamp:1, /* SKB has a RX timestamp */ |
865 | unused:5; | |
1da177e4 | 866 | __u32 ack_seq; /* Sequence number ACK'd */ |
971f10ec | 867 | union { |
b75803d5 | 868 | struct { |
b9f64820 | 869 | /* There is space for up to 24 bytes */ |
d7722e85 SHY |
870 | __u32 in_flight:30,/* Bytes in flight at transmit */ |
871 | is_app_limited:1, /* cwnd not fully used? */ | |
872 | unused:1; | |
b9f64820 YC |
873 | /* pkts S/ACKed so far upon tx of skb, incl retrans: */ |
874 | __u32 delivered; | |
875 | /* start of send pipeline phase */ | |
9a568de4 | 876 | u64 first_tx_mstamp; |
b9f64820 | 877 | /* when we reached the "delivered" count */ |
9a568de4 | 878 | u64 delivered_mstamp; |
b75803d5 LB |
879 | } tx; /* only used for outgoing skbs */ |
880 | union { | |
881 | struct inet_skb_parm h4; | |
971f10ec | 882 | #if IS_ENABLED(CONFIG_IPV6) |
b75803d5 | 883 | struct inet6_skb_parm h6; |
971f10ec | 884 | #endif |
b75803d5 LB |
885 | } header; /* For incoming skbs */ |
886 | }; | |
1da177e4 LT |
887 | }; |
888 | ||
889 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) | |
890 | ||
9b9e2f25 ED |
891 | extern const struct inet_connection_sock_af_ops ipv4_specific; |
892 | ||
815afe17 | 893 | #if IS_ENABLED(CONFIG_IPV6) |
870c3151 ED |
894 | /* This is the variant of inet6_iif() that must be used by TCP, |
895 | * as TCP moves IP6CB into a different location in skb->cb[] | |
896 | */ | |
897 | static inline int tcp_v6_iif(const struct sk_buff *skb) | |
24b711ed DA |
898 | { |
899 | return TCP_SKB_CB(skb)->header.h6.iif; | |
900 | } | |
901 | ||
902 | static inline int tcp_v6_iif_l3_slave(const struct sk_buff *skb) | |
870c3151 | 903 | { |
a04a480d | 904 | bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); |
74b20582 DA |
905 | |
906 | return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; | |
870c3151 | 907 | } |
4297a0ef DA |
908 | |
909 | /* TCP_SKB_CB reference means this can not be used from early demux */ | |
910 | static inline int tcp_v6_sdif(const struct sk_buff *skb) | |
911 | { | |
912 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) | |
913 | if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags)) | |
914 | return TCP_SKB_CB(skb)->header.h6.iif; | |
915 | #endif | |
916 | return 0; | |
917 | } | |
dd2e0b86 | 918 | |
b03d2142 ED |
919 | extern const struct inet_connection_sock_af_ops ipv6_specific; |
920 | ||
dd2e0b86 | 921 | INDIRECT_CALLABLE_DECLARE(void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)); |
243600ee ED |
922 | INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *skb)); |
923 | INDIRECT_CALLABLE_DECLARE(void tcp_v6_early_demux(struct sk_buff *skb)); | |
dd2e0b86 | 924 | |
815afe17 | 925 | #endif |
870c3151 | 926 | |
3fa6f616 DA |
927 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
928 | static inline int tcp_v4_sdif(struct sk_buff *skb) | |
929 | { | |
930 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) | |
931 | if (skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) | |
932 | return TCP_SKB_CB(skb)->header.h4.iif; | |
933 | #endif | |
934 | return 0; | |
935 | } | |
936 | ||
1da177e4 LT |
937 | /* Due to TSO, an SKB can be composed of multiple actual |
938 | * packets. To keep these tracked properly, we use this. | |
bd14b1b2 | 939 | */ |
1da177e4 | 940 | static inline int tcp_skb_pcount(const struct sk_buff *skb) |
bd14b1b2 | 941 | { |
cd7d8498 ED |
942 | return TCP_SKB_CB(skb)->tcp_gso_segs; |
943 | } | |
bd14b1b2 | 944 | |
cd7d8498 ED |
945 | static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) |
946 | { | |
947 | TCP_SKB_CB(skb)->tcp_gso_segs = segs; | |
bd14b1b2 ED |
948 | } |
949 | ||
cd7d8498 | 950 | static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) |
1da177e4 | 951 | { |
cd7d8498 | 952 | TCP_SKB_CB(skb)->tcp_gso_segs += segs; |
1da177e4 LT |
953 | } |
954 | ||
f69ad292 | 955 | /* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ |
1da177e4 LT |
956 | static inline int tcp_skb_mss(const struct sk_buff *skb) |
957 | { | |
f69ad292 | 958 | return TCP_SKB_CB(skb)->tcp_gso_size; |
1da177e4 LT |
959 | } |
960 | ||
c134ecb8 MKL |
961 | static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) |
962 | { | |
963 | return likely(!TCP_SKB_CB(skb)->eor); | |
964 | } | |
965 | ||
85712484 MM |
966 | static inline bool tcp_skb_can_collapse(const struct sk_buff *to, |
967 | const struct sk_buff *from) | |
968 | { | |
969 | return likely(tcp_skb_can_collapse_to(to) && | |
970 | mptcp_skb_can_collapse(to, from)); | |
971 | } | |
972 | ||
317a76f9 SH |
973 | /* Events passed to congestion control interface */ |
974 | enum tcp_ca_event { | |
975 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ | |
976 | CA_EVENT_CWND_RESTART, /* congestion window restart */ | |
977 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ | |
317a76f9 | 978 | CA_EVENT_LOSS, /* loss timeout */ |
9890092e FW |
979 | CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ |
980 | CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ | |
7354c8c3 FW |
981 | }; |
982 | ||
9890092e | 983 | /* Information about inbound ACK, passed to cong_ops->in_ack_event() */ |
7354c8c3 | 984 | enum tcp_ca_ack_event_flags { |
c1d2b4c3 FW |
985 | CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ |
986 | CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ | |
987 | CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ | |
317a76f9 SH |
988 | }; |
989 | ||
990 | /* | |
991 | * Interface for adding new TCP congestion control handlers | |
992 | */ | |
993 | #define TCP_CA_NAME_MAX 16 | |
3ff825b2 SH |
994 | #define TCP_CA_MAX 128 |
995 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) | |
996 | ||
c5c6a8ab DB |
997 | #define TCP_CA_UNSPEC 0 |
998 | ||
30e502a3 | 999 | /* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ |
164891aa | 1000 | #define TCP_CONG_NON_RESTRICTED 0x1 |
30e502a3 DB |
1001 | /* Requires ECN/ECT set on all packets */ |
1002 | #define TCP_CONG_NEEDS_ECN 0x2 | |
0baf26b0 | 1003 | #define TCP_CONG_MASK (TCP_CONG_NON_RESTRICTED | TCP_CONG_NEEDS_ECN) |
164891aa | 1004 | |
64f40ff5 ED |
1005 | union tcp_cc_info; |
1006 | ||
756ee172 LB |
1007 | struct ack_sample { |
1008 | u32 pkts_acked; | |
1009 | s32 rtt_us; | |
6f094b9e | 1010 | u32 in_flight; |
756ee172 LB |
1011 | }; |
1012 | ||
b9f64820 YC |
1013 | /* A rate sample measures the number of (original/retransmitted) data |
1014 | * packets delivered "delivered" over an interval of time "interval_us". | |
1015 | * The tcp_rate.c code fills in the rate sample, and congestion | |
1016 | * control modules that define a cong_control function to run at the end | |
1017 | * of ACK processing can optionally chose to consult this sample when | |
1018 | * setting cwnd and pacing rate. | |
1019 | * A sample is invalid if "delivered" or "interval_us" is negative. | |
1020 | */ | |
1021 | struct rate_sample { | |
9a568de4 | 1022 | u64 prior_mstamp; /* starting timestamp for interval */ |
b9f64820 YC |
1023 | u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ |
1024 | s32 delivered; /* number of packets delivered over interval */ | |
1025 | long interval_us; /* time for tp->delivered to incr "delivered" */ | |
4929c942 DR |
1026 | u32 snd_interval_us; /* snd interval for delivered packets */ |
1027 | u32 rcv_interval_us; /* rcv interval for delivered packets */ | |
b9f64820 YC |
1028 | long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ |
1029 | int losses; /* number of packets marked lost upon ACK */ | |
1030 | u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ | |
1031 | u32 prior_in_flight; /* in flight before this ACK */ | |
d7722e85 | 1032 | bool is_app_limited; /* is sample from packet with bubble in pipe? */ |
b9f64820 | 1033 | bool is_retrans; /* is sample from retransmission? */ |
e4286603 | 1034 | bool is_ack_delayed; /* is this (likely) a delayed ACK? */ |
b9f64820 YC |
1035 | }; |
1036 | ||
317a76f9 | 1037 | struct tcp_congestion_ops { |
82506665 | 1038 | /* fast path fields are put first to fill one cache line */ |
317a76f9 SH |
1039 | |
1040 | /* return slow start threshold (required) */ | |
6687e988 | 1041 | u32 (*ssthresh)(struct sock *sk); |
82506665 | 1042 | |
317a76f9 | 1043 | /* do new cwnd calculation (required) */ |
24901551 | 1044 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); |
82506665 | 1045 | |
317a76f9 | 1046 | /* call before changing ca_state (optional) */ |
6687e988 | 1047 | void (*set_state)(struct sock *sk, u8 new_state); |
82506665 | 1048 | |
317a76f9 | 1049 | /* call when cwnd event occurs (optional) */ |
6687e988 | 1050 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
82506665 | 1051 | |
7354c8c3 FW |
1052 | /* call when ack arrives (optional) */ |
1053 | void (*in_ack_event)(struct sock *sk, u32 flags); | |
82506665 | 1054 | |
317a76f9 | 1055 | /* hook for packet ack accounting (optional) */ |
756ee172 | 1056 | void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); |
82506665 | 1057 | |
dcb8c9b4 ED |
1058 | /* override sysctl_tcp_min_tso_segs */ |
1059 | u32 (*min_tso_segs)(struct sock *sk); | |
82506665 | 1060 | |
c0402760 YC |
1061 | /* call when packets are delivered to update cwnd and pacing rate, |
1062 | * after all the ca_state processing. (optional) | |
1063 | */ | |
1064 | void (*cong_control)(struct sock *sk, const struct rate_sample *rs); | |
82506665 ED |
1065 | |
1066 | ||
1067 | /* new value of cwnd after loss (required) */ | |
1068 | u32 (*undo_cwnd)(struct sock *sk); | |
1069 | /* returns the multiplier used in tcp_sndbuf_expand (optional) */ | |
1070 | u32 (*sndbuf_expand)(struct sock *sk); | |
1071 | ||
1072 | /* control/slow paths put last */ | |
73c1f4a0 | 1073 | /* get info for inet_diag (optional) */ |
64f40ff5 ED |
1074 | size_t (*get_info)(struct sock *sk, u32 ext, int *attr, |
1075 | union tcp_cc_info *info); | |
317a76f9 | 1076 | |
82506665 ED |
1077 | char name[TCP_CA_NAME_MAX]; |
1078 | struct module *owner; | |
1079 | struct list_head list; | |
1080 | u32 key; | |
1081 | u32 flags; | |
1082 | ||
1083 | /* initialize private data (optional) */ | |
1084 | void (*init)(struct sock *sk); | |
1085 | /* cleanup private data (optional) */ | |
1086 | void (*release)(struct sock *sk); | |
1087 | } ____cacheline_aligned_in_smp; | |
317a76f9 | 1088 | |
5c9f3023 JP |
1089 | int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
1090 | void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); | |
317a76f9 | 1091 | |
55d8694f | 1092 | void tcp_assign_congestion_control(struct sock *sk); |
5c9f3023 JP |
1093 | void tcp_init_congestion_control(struct sock *sk); |
1094 | void tcp_cleanup_congestion_control(struct sock *sk); | |
6670e152 SH |
1095 | int tcp_set_default_congestion_control(struct net *net, const char *name); |
1096 | void tcp_get_default_congestion_control(struct net *net, char *name); | |
5c9f3023 JP |
1097 | void tcp_get_available_congestion_control(char *buf, size_t len); |
1098 | void tcp_get_allowed_congestion_control(char *buf, size_t len); | |
1099 | int tcp_set_allowed_congestion_control(char *allowed); | |
8d650cde | 1100 | int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, |
29a94932 | 1101 | bool cap_net_admin); |
e73ebb08 NC |
1102 | u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); |
1103 | void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); | |
317a76f9 | 1104 | |
5c9f3023 | 1105 | u32 tcp_reno_ssthresh(struct sock *sk); |
e9799183 | 1106 | u32 tcp_reno_undo_cwnd(struct sock *sk); |
24901551 | 1107 | void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); |
a8acfbac | 1108 | extern struct tcp_congestion_ops tcp_reno; |
317a76f9 | 1109 | |
0baf26b0 | 1110 | struct tcp_congestion_ops *tcp_ca_find(const char *name); |
c5c6a8ab | 1111 | struct tcp_congestion_ops *tcp_ca_find_key(u32 key); |
6670e152 | 1112 | u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_ca); |
ea697639 | 1113 | #ifdef CONFIG_INET |
c5c6a8ab | 1114 | char *tcp_ca_get_name_by_key(u32 key, char *buffer); |
ea697639 DB |
1115 | #else |
1116 | static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) | |
1117 | { | |
1118 | return NULL; | |
1119 | } | |
1120 | #endif | |
c5c6a8ab | 1121 | |
30e502a3 DB |
1122 | static inline bool tcp_ca_needs_ecn(const struct sock *sk) |
1123 | { | |
1124 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
1125 | ||
1126 | return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; | |
1127 | } | |
1128 | ||
6687e988 | 1129 | static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state) |
317a76f9 | 1130 | { |
6687e988 ACM |
1131 | struct inet_connection_sock *icsk = inet_csk(sk); |
1132 | ||
1133 | if (icsk->icsk_ca_ops->set_state) | |
1134 | icsk->icsk_ca_ops->set_state(sk, ca_state); | |
1135 | icsk->icsk_ca_state = ca_state; | |
317a76f9 SH |
1136 | } |
1137 | ||
6687e988 | 1138 | static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) |
317a76f9 | 1139 | { |
6687e988 ACM |
1140 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1141 | ||
1142 | if (icsk->icsk_ca_ops->cwnd_event) | |
1143 | icsk->icsk_ca_ops->cwnd_event(sk, event); | |
317a76f9 SH |
1144 | } |
1145 | ||
b9f64820 YC |
1146 | /* From tcp_rate.c */ |
1147 | void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); | |
1148 | void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, | |
1149 | struct rate_sample *rs); | |
1150 | void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, | |
d4761754 | 1151 | bool is_sack_reneg, struct rate_sample *rs); |
d7722e85 | 1152 | void tcp_rate_check_app_limited(struct sock *sk); |
b9f64820 | 1153 | |
e60402d0 IJ |
1154 | /* These functions determine how the current flow behaves in respect of SACK |
1155 | * handling. SACK is negotiated with the peer, and therefore it can vary | |
1156 | * between different flows. | |
1157 | * | |
1158 | * tcp_is_sack - SACK enabled | |
1159 | * tcp_is_reno - No SACK | |
e60402d0 IJ |
1160 | */ |
1161 | static inline int tcp_is_sack(const struct tcp_sock *tp) | |
1162 | { | |
ebeef4bc | 1163 | return likely(tp->rx_opt.sack_ok); |
e60402d0 IJ |
1164 | } |
1165 | ||
a2a385d6 | 1166 | static inline bool tcp_is_reno(const struct tcp_sock *tp) |
e60402d0 IJ |
1167 | { |
1168 | return !tcp_is_sack(tp); | |
1169 | } | |
1170 | ||
83ae4088 IJ |
1171 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
1172 | { | |
1173 | return tp->sacked_out + tp->lost_out; | |
1174 | } | |
1175 | ||
1da177e4 LT |
1176 | /* This determines how many packets are "in the network" to the best |
1177 | * of our knowledge. In many cases it is conservative, but where | |
1178 | * detailed information is available from the receiver (via SACK | |
1179 | * blocks etc.) we can make more aggressive calculations. | |
1180 | * | |
1181 | * Use this for decisions involving congestion control, use just | |
1182 | * tp->packets_out to determine if the send queue is empty or not. | |
1183 | * | |
1184 | * Read this equation as: | |
1185 | * | |
1186 | * "Packets sent once on transmission queue" MINUS | |
1187 | * "Packets left network, but not honestly ACKed yet" PLUS | |
1188 | * "Packets fast retransmitted" | |
1189 | */ | |
40efc6fa | 1190 | static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
1da177e4 | 1191 | { |
83ae4088 | 1192 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
1da177e4 LT |
1193 | } |
1194 | ||
0b6a05c1 IJ |
1195 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
1196 | ||
071d5080 YC |
1197 | static inline bool tcp_in_slow_start(const struct tcp_sock *tp) |
1198 | { | |
76174004 | 1199 | return tp->snd_cwnd < tp->snd_ssthresh; |
071d5080 YC |
1200 | } |
1201 | ||
0b6a05c1 IJ |
1202 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) |
1203 | { | |
1204 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; | |
1205 | } | |
1206 | ||
684bad11 YC |
1207 | static inline bool tcp_in_cwnd_reduction(const struct sock *sk) |
1208 | { | |
1209 | return (TCPF_CA_CWR | TCPF_CA_Recovery) & | |
1210 | (1 << inet_csk(sk)->icsk_ca_state); | |
1211 | } | |
1212 | ||
1da177e4 | 1213 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
684bad11 | 1214 | * The exception is cwnd reduction phase, when cwnd is decreasing towards |
1da177e4 LT |
1215 | * ssthresh. |
1216 | */ | |
6687e988 | 1217 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
1da177e4 | 1218 | { |
6687e988 | 1219 | const struct tcp_sock *tp = tcp_sk(sk); |
cf533ea5 | 1220 | |
684bad11 | 1221 | if (tcp_in_cwnd_reduction(sk)) |
1da177e4 LT |
1222 | return tp->snd_ssthresh; |
1223 | else | |
1224 | return max(tp->snd_ssthresh, | |
1225 | ((tp->snd_cwnd >> 1) + | |
1226 | (tp->snd_cwnd >> 2))); | |
1227 | } | |
1228 | ||
b9c4595b IJ |
1229 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
1230 | #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) | |
1da177e4 | 1231 | |
5ee2c941 | 1232 | void tcp_enter_cwr(struct sock *sk); |
5c9f3023 | 1233 | __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); |
1da177e4 | 1234 | |
6b5a5c0d NC |
1235 | /* The maximum number of MSS of available cwnd for which TSO defers |
1236 | * sending if not using sysctl_tcp_tso_win_divisor. | |
1237 | */ | |
1238 | static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) | |
1239 | { | |
1240 | return 3; | |
1241 | } | |
1242 | ||
90840def IJ |
1243 | /* Returns end sequence number of the receiver's advertised window */ |
1244 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) | |
1245 | { | |
1246 | return tp->snd_una + tp->snd_wnd; | |
1247 | } | |
e114a710 ED |
1248 | |
1249 | /* We follow the spirit of RFC2861 to validate cwnd but implement a more | |
1250 | * flexible approach. The RFC suggests cwnd should not be raised unless | |
ca8a2263 NC |
1251 | * it was fully used previously. And that's exactly what we do in |
1252 | * congestion avoidance mode. But in slow start we allow cwnd to grow | |
1253 | * as long as the application has used half the cwnd. | |
e114a710 ED |
1254 | * Example : |
1255 | * cwnd is 10 (IW10), but application sends 9 frames. | |
1256 | * We allow cwnd to reach 18 when all frames are ACKed. | |
1257 | * This check is safe because it's as aggressive as slow start which already | |
1258 | * risks 100% overshoot. The advantage is that we discourage application to | |
1259 | * either send more filler packets or data to artificially blow up the cwnd | |
1260 | * usage, and allow application-limited process to probe bw more aggressively. | |
e114a710 | 1261 | */ |
24901551 | 1262 | static inline bool tcp_is_cwnd_limited(const struct sock *sk) |
e114a710 ED |
1263 | { |
1264 | const struct tcp_sock *tp = tcp_sk(sk); | |
1265 | ||
ca8a2263 | 1266 | /* If in slow start, ensure cwnd grows to twice what was ACKed. */ |
071d5080 | 1267 | if (tcp_in_slow_start(tp)) |
ca8a2263 NC |
1268 | return tp->snd_cwnd < 2 * tp->max_packets_out; |
1269 | ||
1270 | return tp->is_cwnd_limited; | |
e114a710 | 1271 | } |
f4805ede | 1272 | |
cadefe5f ED |
1273 | /* BBR congestion control needs pacing. |
1274 | * Same remark for SO_MAX_PACING_RATE. | |
1275 | * sch_fq packet scheduler is efficiently handling pacing, | |
1276 | * but is not always installed/used. | |
1277 | * Return true if TCP stack should pace packets itself. | |
1278 | */ | |
1279 | static inline bool tcp_needs_internal_pacing(const struct sock *sk) | |
1280 | { | |
1281 | return smp_load_acquire(&sk->sk_pacing_status) == SK_PACING_NEEDED; | |
1282 | } | |
1283 | ||
8dc242ad ED |
1284 | /* Estimates in how many jiffies next packet for this flow can be sent. |
1285 | * Scheduling a retransmit timer too early would be silly. | |
3f80e08f | 1286 | */ |
8dc242ad | 1287 | static inline unsigned long tcp_pacing_delay(const struct sock *sk) |
3f80e08f | 1288 | { |
8dc242ad | 1289 | s64 delay = tcp_sk(sk)->tcp_wstamp_ns - tcp_sk(sk)->tcp_clock_cache; |
3f80e08f | 1290 | |
8dc242ad | 1291 | return delay > 0 ? nsecs_to_jiffies(delay) : 0; |
3f80e08f ED |
1292 | } |
1293 | ||
1294 | static inline void tcp_reset_xmit_timer(struct sock *sk, | |
1295 | const int what, | |
1296 | unsigned long when, | |
8dc242ad | 1297 | const unsigned long max_when) |
3f80e08f | 1298 | { |
8dc242ad | 1299 | inet_csk_reset_xmit_timer(sk, what, when + tcp_pacing_delay(sk), |
3f80e08f ED |
1300 | max_when); |
1301 | } | |
1302 | ||
21c8fe99 | 1303 | /* Something is really bad, we could not queue an additional packet, |
3f80e08f | 1304 | * because qdisc is full or receiver sent a 0 window, or we are paced. |
21c8fe99 ED |
1305 | * We do not want to add fuel to the fire, or abort too early, |
1306 | * so make sure the timer we arm now is at least 200ms in the future, | |
1307 | * regardless of current icsk_rto value (as it could be ~2ms) | |
1308 | */ | |
1309 | static inline unsigned long tcp_probe0_base(const struct sock *sk) | |
1da177e4 | 1310 | { |
21c8fe99 ED |
1311 | return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); |
1312 | } | |
9e412ba7 | 1313 | |
21c8fe99 ED |
1314 | /* Variant of inet_csk_rto_backoff() used for zero window probes */ |
1315 | static inline unsigned long tcp_probe0_when(const struct sock *sk, | |
1316 | unsigned long max_when) | |
1317 | { | |
6d4634d1 CZ |
1318 | u8 backoff = min_t(u8, ilog2(TCP_RTO_MAX / TCP_RTO_MIN) + 1, |
1319 | inet_csk(sk)->icsk_backoff); | |
1320 | u64 when = (u64)tcp_probe0_base(sk) << backoff; | |
21c8fe99 ED |
1321 | |
1322 | return (unsigned long)min_t(u64, when, max_when); | |
1323 | } | |
1324 | ||
1325 | static inline void tcp_check_probe_timer(struct sock *sk) | |
1326 | { | |
1327 | if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) | |
3f80e08f | 1328 | tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
8dc242ad | 1329 | tcp_probe0_base(sk), TCP_RTO_MAX); |
1da177e4 LT |
1330 | } |
1331 | ||
ee7537b6 | 1332 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
1333 | { |
1334 | tp->snd_wl1 = seq; | |
1335 | } | |
1336 | ||
ee7537b6 | 1337 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
1da177e4 LT |
1338 | { |
1339 | tp->snd_wl1 = seq; | |
1340 | } | |
1341 | ||
1da177e4 LT |
1342 | /* |
1343 | * Calculate(/check) TCP checksum | |
1344 | */ | |
ba7808ea FD |
1345 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
1346 | __be32 daddr, __wsum base) | |
1da177e4 | 1347 | { |
0b13c9bb | 1348 | return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_TCP, base); |
1da177e4 LT |
1349 | } |
1350 | ||
a2a385d6 | 1351 | static inline bool tcp_checksum_complete(struct sk_buff *skb) |
1da177e4 | 1352 | { |
60476372 | 1353 | return !skb_csum_unnecessary(skb) && |
6ab6dfa6 | 1354 | __skb_checksum_complete(skb); |
1da177e4 LT |
1355 | } |
1356 | ||
c9c33212 | 1357 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb); |
ac6e7800 | 1358 | int tcp_filter(struct sock *sk, struct sk_buff *skb); |
5c9f3023 | 1359 | void tcp_set_state(struct sock *sk, int state); |
5c9f3023 | 1360 | void tcp_done(struct sock *sk); |
c1e64e29 LC |
1361 | int tcp_abort(struct sock *sk, int err); |
1362 | ||
40efc6fa | 1363 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
1da177e4 LT |
1364 | { |
1365 | rx_opt->dsack = 0; | |
1da177e4 LT |
1366 | rx_opt->num_sacks = 0; |
1367 | } | |
1368 | ||
6f021c62 ED |
1369 | void tcp_cwnd_restart(struct sock *sk, s32 delta); |
1370 | ||
1371 | static inline void tcp_slow_start_after_idle_check(struct sock *sk) | |
1372 | { | |
1b1fc3fd | 1373 | const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; |
6f021c62 ED |
1374 | struct tcp_sock *tp = tcp_sk(sk); |
1375 | s32 delta; | |
1376 | ||
b510f0d2 | 1377 | if (!sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle || tp->packets_out || |
1b1fc3fd | 1378 | ca_ops->cong_control) |
6f021c62 | 1379 | return; |
d635fbe2 | 1380 | delta = tcp_jiffies32 - tp->lsndtime; |
6f021c62 ED |
1381 | if (delta > inet_csk(sk)->icsk_rto) |
1382 | tcp_cwnd_restart(sk, delta); | |
1383 | } | |
85f16525 | 1384 | |
1da177e4 | 1385 | /* Determine a window scaling and initial window to offer. */ |
ceef9ab6 ED |
1386 | void tcp_select_initial_window(const struct sock *sk, int __space, |
1387 | __u32 mss, __u32 *rcv_wnd, | |
5c9f3023 JP |
1388 | __u32 *window_clamp, int wscale_ok, |
1389 | __u8 *rcv_wscale, __u32 init_rcv_wnd); | |
1da177e4 | 1390 | |
94f0893e | 1391 | static inline int tcp_win_from_space(const struct sock *sk, int space) |
1da177e4 | 1392 | { |
94f0893e | 1393 | int tcp_adv_win_scale = sock_net(sk)->ipv4.sysctl_tcp_adv_win_scale; |
c4836742 GF |
1394 | |
1395 | return tcp_adv_win_scale <= 0 ? | |
1396 | (space>>(-tcp_adv_win_scale)) : | |
1397 | space - (space>>tcp_adv_win_scale); | |
1da177e4 LT |
1398 | } |
1399 | ||
105970f6 | 1400 | /* Note: caller must be prepared to deal with negative returns */ |
1da177e4 LT |
1401 | static inline int tcp_space(const struct sock *sk) |
1402 | { | |
ebb3b78d | 1403 | return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - |
70c26558 | 1404 | READ_ONCE(sk->sk_backlog.len) - |
1da177e4 | 1405 | atomic_read(&sk->sk_rmem_alloc)); |
105970f6 | 1406 | } |
1da177e4 LT |
1407 | |
1408 | static inline int tcp_full_space(const struct sock *sk) | |
1409 | { | |
ebb3b78d | 1410 | return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); |
1da177e4 LT |
1411 | } |
1412 | ||
c76c6956 PA |
1413 | void tcp_cleanup_rbuf(struct sock *sk, int copied); |
1414 | ||
24adbc16 ED |
1415 | /* We provision sk_rcvbuf around 200% of sk_rcvlowat. |
1416 | * If 87.5 % (7/8) of the space has been consumed, we want to override | |
1417 | * SO_RCVLOWAT constraint, since we are receiving skbs with too small | |
1418 | * len/truesize ratio. | |
1419 | */ | |
1420 | static inline bool tcp_rmem_pressure(const struct sock *sk) | |
1421 | { | |
f969dc5a ED |
1422 | int rcvbuf, threshold; |
1423 | ||
1424 | if (tcp_under_memory_pressure(sk)) | |
1425 | return true; | |
1426 | ||
1427 | rcvbuf = READ_ONCE(sk->sk_rcvbuf); | |
1428 | threshold = rcvbuf - (rcvbuf >> 3); | |
24adbc16 ED |
1429 | |
1430 | return atomic_read(&sk->sk_rmem_alloc) > threshold; | |
1431 | } | |
1432 | ||
05dc72ab ED |
1433 | static inline bool tcp_epollin_ready(const struct sock *sk, int target) |
1434 | { | |
1435 | const struct tcp_sock *tp = tcp_sk(sk); | |
1436 | int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); | |
1437 | ||
1438 | if (avail <= 0) | |
1439 | return false; | |
1440 | ||
1441 | return (avail >= target) || tcp_rmem_pressure(sk) || | |
1442 | (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss); | |
1443 | } | |
1444 | ||
843f4a55 | 1445 | extern void tcp_openreq_init_rwin(struct request_sock *req, |
b1964b5f ED |
1446 | const struct sock *sk_listener, |
1447 | const struct dst_entry *dst); | |
843f4a55 | 1448 | |
5c9f3023 | 1449 | void tcp_enter_memory_pressure(struct sock *sk); |
06044751 | 1450 | void tcp_leave_memory_pressure(struct sock *sk); |
1da177e4 | 1451 | |
1da177e4 LT |
1452 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
1453 | { | |
b840d15d NB |
1454 | struct net *net = sock_net((struct sock *)tp); |
1455 | ||
1456 | return tp->keepalive_intvl ? : net->ipv4.sysctl_tcp_keepalive_intvl; | |
1da177e4 LT |
1457 | } |
1458 | ||
1459 | static inline int keepalive_time_when(const struct tcp_sock *tp) | |
1460 | { | |
13b287e8 NB |
1461 | struct net *net = sock_net((struct sock *)tp); |
1462 | ||
1463 | return tp->keepalive_time ? : net->ipv4.sysctl_tcp_keepalive_time; | |
1da177e4 LT |
1464 | } |
1465 | ||
df19a626 ED |
1466 | static inline int keepalive_probes(const struct tcp_sock *tp) |
1467 | { | |
9bd6861b NB |
1468 | struct net *net = sock_net((struct sock *)tp); |
1469 | ||
1470 | return tp->keepalive_probes ? : net->ipv4.sysctl_tcp_keepalive_probes; | |
df19a626 ED |
1471 | } |
1472 | ||
6c37e5de FL |
1473 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
1474 | { | |
1475 | const struct inet_connection_sock *icsk = &tp->inet_conn; | |
1476 | ||
70eabf0e ED |
1477 | return min_t(u32, tcp_jiffies32 - icsk->icsk_ack.lrcvtime, |
1478 | tcp_jiffies32 - tp->rcv_tstamp); | |
6c37e5de FL |
1479 | } |
1480 | ||
463c84b9 | 1481 | static inline int tcp_fin_time(const struct sock *sk) |
1da177e4 | 1482 | { |
1e579caa | 1483 | int fin_timeout = tcp_sk(sk)->linger2 ? : sock_net(sk)->ipv4.sysctl_tcp_fin_timeout; |
463c84b9 | 1484 | const int rto = inet_csk(sk)->icsk_rto; |
1da177e4 | 1485 | |
463c84b9 ACM |
1486 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
1487 | fin_timeout = (rto << 2) - (rto >> 1); | |
1da177e4 LT |
1488 | |
1489 | return fin_timeout; | |
1490 | } | |
1491 | ||
a2a385d6 ED |
1492 | static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, |
1493 | int paws_win) | |
1da177e4 | 1494 | { |
c887e6d2 | 1495 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
a2a385d6 | 1496 | return true; |
cca9bab1 AB |
1497 | if (unlikely(!time_before32(ktime_get_seconds(), |
1498 | rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS))) | |
a2a385d6 | 1499 | return true; |
bc2ce894 ED |
1500 | /* |
1501 | * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, | |
1502 | * then following tcp messages have valid values. Ignore 0 value, | |
1503 | * or else 'negative' tsval might forbid us to accept their packets. | |
1504 | */ | |
1505 | if (!rx_opt->ts_recent) | |
a2a385d6 ED |
1506 | return true; |
1507 | return false; | |
c887e6d2 IJ |
1508 | } |
1509 | ||
a2a385d6 ED |
1510 | static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, |
1511 | int rst) | |
c887e6d2 IJ |
1512 | { |
1513 | if (tcp_paws_check(rx_opt, 0)) | |
a2a385d6 | 1514 | return false; |
1da177e4 LT |
1515 | |
1516 | /* RST segments are not recommended to carry timestamp, | |
1517 | and, if they do, it is recommended to ignore PAWS because | |
1518 | "their cleanup function should take precedence over timestamps." | |
1519 | Certainly, it is mistake. It is necessary to understand the reasons | |
1520 | of this constraint to relax it: if peer reboots, clock may go | |
1521 | out-of-sync and half-open connections will not be reset. | |
1522 | Actually, the problem would be not existing if all | |
1523 | the implementations followed draft about maintaining clock | |
1524 | via reboots. Linux-2.2 DOES NOT! | |
1525 | ||
1526 | However, we can relax time bounds for RST segments to MSL. | |
1527 | */ | |
cca9bab1 AB |
1528 | if (rst && !time_before32(ktime_get_seconds(), |
1529 | rx_opt->ts_recent_stamp + TCP_PAWS_MSL)) | |
a2a385d6 ED |
1530 | return false; |
1531 | return true; | |
1da177e4 LT |
1532 | } |
1533 | ||
7970ddc8 ED |
1534 | bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, |
1535 | int mib_idx, u32 *last_oow_ack_time); | |
032ee423 | 1536 | |
a9c19329 | 1537 | static inline void tcp_mib_init(struct net *net) |
1da177e4 LT |
1538 | { |
1539 | /* See RFC 2012 */ | |
6aef70a8 ED |
1540 | TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); |
1541 | TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); | |
1542 | TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); | |
1543 | TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); | |
1da177e4 LT |
1544 | } |
1545 | ||
5af4ec23 | 1546 | /* from STCP */ |
ef9da47c | 1547 | static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) |
0800f170 | 1548 | { |
6a438bbe | 1549 | tp->lost_skb_hint = NULL; |
ef9da47c IJ |
1550 | } |
1551 | ||
1552 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) | |
1553 | { | |
1554 | tcp_clear_retrans_hints_partial(tp); | |
6a438bbe | 1555 | tp->retransmit_skb_hint = NULL; |
b7689205 IJ |
1556 | } |
1557 | ||
a915da9b ED |
1558 | union tcp_md5_addr { |
1559 | struct in_addr a4; | |
1560 | #if IS_ENABLED(CONFIG_IPV6) | |
1561 | struct in6_addr a6; | |
1562 | #endif | |
1563 | }; | |
1564 | ||
cfb6eeb4 YH |
1565 | /* - key database */ |
1566 | struct tcp_md5sig_key { | |
a915da9b | 1567 | struct hlist_node node; |
cfb6eeb4 | 1568 | u8 keylen; |
a915da9b | 1569 | u8 family; /* AF_INET or AF_INET6 */ |
6797318e | 1570 | u8 prefixlen; |
dea53bb8 DA |
1571 | union tcp_md5_addr addr; |
1572 | int l3index; /* set if key added with L3 scope */ | |
a915da9b ED |
1573 | u8 key[TCP_MD5SIG_MAXKEYLEN]; |
1574 | struct rcu_head rcu; | |
cfb6eeb4 YH |
1575 | }; |
1576 | ||
1577 | /* - sock block */ | |
1578 | struct tcp_md5sig_info { | |
a915da9b | 1579 | struct hlist_head head; |
a8afca03 | 1580 | struct rcu_head rcu; |
cfb6eeb4 YH |
1581 | }; |
1582 | ||
1583 | /* - pseudo header */ | |
1584 | struct tcp4_pseudohdr { | |
1585 | __be32 saddr; | |
1586 | __be32 daddr; | |
1587 | __u8 pad; | |
1588 | __u8 protocol; | |
1589 | __be16 len; | |
1590 | }; | |
1591 | ||
1592 | struct tcp6_pseudohdr { | |
1593 | struct in6_addr saddr; | |
1594 | struct in6_addr daddr; | |
1595 | __be32 len; | |
1596 | __be32 protocol; /* including padding */ | |
1597 | }; | |
1598 | ||
1599 | union tcp_md5sum_block { | |
1600 | struct tcp4_pseudohdr ip4; | |
dfd56b8b | 1601 | #if IS_ENABLED(CONFIG_IPV6) |
cfb6eeb4 YH |
1602 | struct tcp6_pseudohdr ip6; |
1603 | #endif | |
1604 | }; | |
1605 | ||
1606 | /* - pool: digest algorithm, hash description and scratch buffer */ | |
1607 | struct tcp_md5sig_pool { | |
cf80e0e4 | 1608 | struct ahash_request *md5_req; |
19689e38 | 1609 | void *scratch; |
cfb6eeb4 YH |
1610 | }; |
1611 | ||
cfb6eeb4 | 1612 | /* - functions */ |
39f8e58e ED |
1613 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
1614 | const struct sock *sk, const struct sk_buff *skb); | |
5c9f3023 | 1615 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
dea53bb8 DA |
1616 | int family, u8 prefixlen, int l3index, |
1617 | const u8 *newkey, u8 newkeylen, gfp_t gfp); | |
5c9f3023 | 1618 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, |
dea53bb8 | 1619 | int family, u8 prefixlen, int l3index); |
b83e3deb | 1620 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
fd3a154a | 1621 | const struct sock *addr_sk); |
cfb6eeb4 | 1622 | |
9501f972 | 1623 | #ifdef CONFIG_TCP_MD5SIG |
6015c71e | 1624 | #include <linux/jump_label.h> |
921f9a0f | 1625 | extern struct static_key_false tcp_md5_needed; |
dea53bb8 | 1626 | struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, |
6015c71e ED |
1627 | const union tcp_md5_addr *addr, |
1628 | int family); | |
1629 | static inline struct tcp_md5sig_key * | |
dea53bb8 DA |
1630 | tcp_md5_do_lookup(const struct sock *sk, int l3index, |
1631 | const union tcp_md5_addr *addr, int family) | |
6015c71e | 1632 | { |
921f9a0f | 1633 | if (!static_branch_unlikely(&tcp_md5_needed)) |
6015c71e | 1634 | return NULL; |
dea53bb8 | 1635 | return __tcp_md5_do_lookup(sk, l3index, addr, family); |
6015c71e ED |
1636 | } |
1637 | ||
a915da9b | 1638 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) |
9501f972 | 1639 | #else |
dea53bb8 DA |
1640 | static inline struct tcp_md5sig_key * |
1641 | tcp_md5_do_lookup(const struct sock *sk, int l3index, | |
1642 | const union tcp_md5_addr *addr, int family) | |
a915da9b ED |
1643 | { |
1644 | return NULL; | |
1645 | } | |
9501f972 YH |
1646 | #define tcp_twsk_md5_key(twsk) NULL |
1647 | #endif | |
1648 | ||
5c9f3023 | 1649 | bool tcp_alloc_md5sig_pool(void); |
cfb6eeb4 | 1650 | |
5c9f3023 | 1651 | struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); |
71cea17e ED |
1652 | static inline void tcp_put_md5sig_pool(void) |
1653 | { | |
1654 | local_bh_enable(); | |
1655 | } | |
35790c04 | 1656 | |
5c9f3023 JP |
1657 | int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *, |
1658 | unsigned int header_len); | |
1659 | int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, | |
1660 | const struct tcp_md5sig_key *key); | |
cfb6eeb4 | 1661 | |
10467163 | 1662 | /* From tcp_fastopen.c */ |
5c9f3023 | 1663 | void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
7268586b | 1664 | struct tcp_fastopen_cookie *cookie); |
5c9f3023 | 1665 | void tcp_fastopen_cache_set(struct sock *sk, u16 mss, |
2646c831 DL |
1666 | struct tcp_fastopen_cookie *cookie, bool syn_lost, |
1667 | u16 try_exp); | |
783237e8 YC |
1668 | struct tcp_fastopen_request { |
1669 | /* Fast Open cookie. Size 0 means a cookie request */ | |
1670 | struct tcp_fastopen_cookie cookie; | |
1671 | struct msghdr *data; /* data in MSG_FASTOPEN */ | |
f5ddcbbb ED |
1672 | size_t size; |
1673 | int copied; /* queued in tcp_connect() */ | |
f859a448 | 1674 | struct ubuf_info *uarg; |
783237e8 | 1675 | }; |
783237e8 | 1676 | void tcp_free_fastopen_req(struct tcp_sock *tp); |
1fba70e5 | 1677 | void tcp_fastopen_destroy_cipher(struct sock *sk); |
43713848 | 1678 | void tcp_fastopen_ctx_destroy(struct net *net); |
1fba70e5 | 1679 | int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, |
438ac880 | 1680 | void *primary_key, void *backup_key); |
f19008e6 JB |
1681 | int tcp_fastopen_get_cipher(struct net *net, struct inet_connection_sock *icsk, |
1682 | u64 *key); | |
61d2bcae | 1683 | void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); |
7c85af88 ED |
1684 | struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, |
1685 | struct request_sock *req, | |
71c02379 CP |
1686 | struct tcp_fastopen_cookie *foc, |
1687 | const struct dst_entry *dst); | |
43713848 | 1688 | void tcp_fastopen_init_key_once(struct net *net); |
065263f4 WW |
1689 | bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, |
1690 | struct tcp_fastopen_cookie *cookie); | |
19f6d3f3 | 1691 | bool tcp_fastopen_defer_connect(struct sock *sk, int *err); |
438ac880 | 1692 | #define TCP_FASTOPEN_KEY_LENGTH sizeof(siphash_key_t) |
9092a76d JB |
1693 | #define TCP_FASTOPEN_KEY_MAX 2 |
1694 | #define TCP_FASTOPEN_KEY_BUF_LENGTH \ | |
1695 | (TCP_FASTOPEN_KEY_LENGTH * TCP_FASTOPEN_KEY_MAX) | |
10467163 JC |
1696 | |
1697 | /* Fastopen key context */ | |
1698 | struct tcp_fastopen_context { | |
438ac880 | 1699 | siphash_key_t key[TCP_FASTOPEN_KEY_MAX]; |
c681edae AB |
1700 | int num; |
1701 | struct rcu_head rcu; | |
10467163 JC |
1702 | }; |
1703 | ||
cf1ef3f0 | 1704 | extern unsigned int sysctl_tcp_fastopen_blackhole_timeout; |
46c2fa39 | 1705 | void tcp_fastopen_active_disable(struct sock *sk); |
cf1ef3f0 WW |
1706 | bool tcp_fastopen_active_should_disable(struct sock *sk); |
1707 | void tcp_fastopen_active_disable_ofo_check(struct sock *sk); | |
7268586b | 1708 | void tcp_fastopen_active_detect_blackhole(struct sock *sk, bool expired); |
cf1ef3f0 | 1709 | |
9092a76d JB |
1710 | /* Caller needs to wrap with rcu_read_(un)lock() */ |
1711 | static inline | |
1712 | struct tcp_fastopen_context *tcp_fastopen_get_ctx(const struct sock *sk) | |
1713 | { | |
1714 | struct tcp_fastopen_context *ctx; | |
1715 | ||
1716 | ctx = rcu_dereference(inet_csk(sk)->icsk_accept_queue.fastopenq.ctx); | |
1717 | if (!ctx) | |
1718 | ctx = rcu_dereference(sock_net(sk)->ipv4.tcp_fastopen_ctx); | |
1719 | return ctx; | |
1720 | } | |
1721 | ||
1722 | static inline | |
1723 | bool tcp_fastopen_cookie_match(const struct tcp_fastopen_cookie *foc, | |
1724 | const struct tcp_fastopen_cookie *orig) | |
1725 | { | |
1726 | if (orig->len == TCP_FASTOPEN_COOKIE_SIZE && | |
1727 | orig->len == foc->len && | |
1728 | !memcmp(orig->val, foc->val, foc->len)) | |
1729 | return true; | |
1730 | return false; | |
1731 | } | |
1732 | ||
1733 | static inline | |
1734 | int tcp_fastopen_context_len(const struct tcp_fastopen_context *ctx) | |
1735 | { | |
c681edae | 1736 | return ctx->num; |
9092a76d JB |
1737 | } |
1738 | ||
05b055e8 FY |
1739 | /* Latencies incurred by various limits for a sender. They are |
1740 | * chronograph-like stats that are mutually exclusive. | |
1741 | */ | |
1742 | enum tcp_chrono { | |
1743 | TCP_CHRONO_UNSPEC, | |
1744 | TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ | |
1745 | TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ | |
1746 | TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ | |
1747 | __TCP_CHRONO_MAX, | |
1748 | }; | |
1749 | ||
1750 | void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); | |
1751 | void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); | |
1752 | ||
e2080072 ED |
1753 | /* This helper is needed, because skb->tcp_tsorted_anchor uses |
1754 | * the same memory storage than skb->destructor/_skb_refdst | |
1755 | */ | |
1756 | static inline void tcp_skb_tsorted_anchor_cleanup(struct sk_buff *skb) | |
1757 | { | |
1758 | skb->destructor = NULL; | |
1759 | skb->_skb_refdst = 0UL; | |
1760 | } | |
1761 | ||
1762 | #define tcp_skb_tsorted_save(skb) { \ | |
1763 | unsigned long _save = skb->_skb_refdst; \ | |
1764 | skb->_skb_refdst = 0UL; | |
1765 | ||
1766 | #define tcp_skb_tsorted_restore(skb) \ | |
1767 | skb->_skb_refdst = _save; \ | |
1768 | } | |
1769 | ||
ac3f09ba | 1770 | void tcp_write_queue_purge(struct sock *sk); |
fe067e8a | 1771 | |
75c119af ED |
1772 | static inline struct sk_buff *tcp_rtx_queue_head(const struct sock *sk) |
1773 | { | |
1774 | return skb_rb_first(&sk->tcp_rtx_queue); | |
1775 | } | |
1776 | ||
b617158d ED |
1777 | static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) |
1778 | { | |
1779 | return skb_rb_last(&sk->tcp_rtx_queue); | |
1780 | } | |
1781 | ||
cf533ea5 | 1782 | static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) |
fe067e8a | 1783 | { |
cd07a8ea | 1784 | return skb_peek(&sk->sk_write_queue); |
fe067e8a DM |
1785 | } |
1786 | ||
cf533ea5 | 1787 | static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) |
fe067e8a | 1788 | { |
cd07a8ea | 1789 | return skb_peek_tail(&sk->sk_write_queue); |
fe067e8a DM |
1790 | } |
1791 | ||
234b6860 | 1792 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
cd07a8ea | 1793 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
234b6860 | 1794 | |
cf533ea5 | 1795 | static inline struct sk_buff *tcp_send_head(const struct sock *sk) |
fe067e8a | 1796 | { |
75c119af | 1797 | return skb_peek(&sk->sk_write_queue); |
fe067e8a DM |
1798 | } |
1799 | ||
cd07a8ea DM |
1800 | static inline bool tcp_skb_is_last(const struct sock *sk, |
1801 | const struct sk_buff *skb) | |
1802 | { | |
1803 | return skb_queue_is_last(&sk->sk_write_queue, skb); | |
1804 | } | |
1805 | ||
ee2aabd3 ED |
1806 | /** |
1807 | * tcp_write_queue_empty - test if any payload (or FIN) is available in write queue | |
1808 | * @sk: socket | |
1809 | * | |
1810 | * Since the write queue can have a temporary empty skb in it, | |
1811 | * we must not use "return skb_queue_empty(&sk->sk_write_queue)" | |
1812 | */ | |
75c119af | 1813 | static inline bool tcp_write_queue_empty(const struct sock *sk) |
fe067e8a | 1814 | { |
ee2aabd3 ED |
1815 | const struct tcp_sock *tp = tcp_sk(sk); |
1816 | ||
1817 | return tp->write_seq == tp->snd_nxt; | |
75c119af ED |
1818 | } |
1819 | ||
1820 | static inline bool tcp_rtx_queue_empty(const struct sock *sk) | |
1821 | { | |
1822 | return RB_EMPTY_ROOT(&sk->tcp_rtx_queue); | |
1823 | } | |
1824 | ||
1825 | static inline bool tcp_rtx_and_write_queues_empty(const struct sock *sk) | |
1826 | { | |
1827 | return tcp_rtx_queue_empty(sk) && tcp_write_queue_empty(sk); | |
fe067e8a DM |
1828 | } |
1829 | ||
fe067e8a DM |
1830 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) |
1831 | { | |
a43e052b | 1832 | __skb_queue_tail(&sk->sk_write_queue, skb); |
fe067e8a DM |
1833 | |
1834 | /* Queue it, remembering where we must start sending. */ | |
50895b9d | 1835 | if (sk->sk_write_queue.next == skb) |
0f87230d | 1836 | tcp_chrono_start(sk, TCP_CHRONO_BUSY); |
fe067e8a DM |
1837 | } |
1838 | ||
43f59c89 | 1839 | /* Insert new before skb on the write queue of sk. */ |
fe067e8a DM |
1840 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
1841 | struct sk_buff *skb, | |
1842 | struct sock *sk) | |
1843 | { | |
43f59c89 | 1844 | __skb_queue_before(&sk->sk_write_queue, skb, new); |
fe067e8a DM |
1845 | } |
1846 | ||
1847 | static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) | |
1848 | { | |
4a269818 | 1849 | tcp_skb_tsorted_anchor_cleanup(skb); |
fe067e8a DM |
1850 | __skb_unlink(skb, &sk->sk_write_queue); |
1851 | } | |
1852 | ||
75c119af ED |
1853 | void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb); |
1854 | ||
1855 | static inline void tcp_rtx_queue_unlink(struct sk_buff *skb, struct sock *sk) | |
fe067e8a | 1856 | { |
75c119af ED |
1857 | tcp_skb_tsorted_anchor_cleanup(skb); |
1858 | rb_erase(&skb->rbnode, &sk->tcp_rtx_queue); | |
1859 | } | |
1860 | ||
1861 | static inline void tcp_rtx_queue_unlink_and_free(struct sk_buff *skb, struct sock *sk) | |
1862 | { | |
1863 | list_del(&skb->tcp_tsorted_anchor); | |
1864 | tcp_rtx_queue_unlink(skb, sk); | |
1865 | sk_wmem_free_skb(sk, skb); | |
fe067e8a DM |
1866 | } |
1867 | ||
12d50c46 KK |
1868 | static inline void tcp_push_pending_frames(struct sock *sk) |
1869 | { | |
1870 | if (tcp_send_head(sk)) { | |
1871 | struct tcp_sock *tp = tcp_sk(sk); | |
1872 | ||
1873 | __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); | |
1874 | } | |
1875 | } | |
1876 | ||
ecb97192 NC |
1877 | /* Start sequence of the skb just after the highest skb with SACKed |
1878 | * bit, valid only if sacked_out > 0 or when the caller has ensured | |
1879 | * validity by itself. | |
a47e5a98 IJ |
1880 | */ |
1881 | static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) | |
1882 | { | |
1883 | if (!tp->sacked_out) | |
1884 | return tp->snd_una; | |
6859d494 IJ |
1885 | |
1886 | if (tp->highest_sack == NULL) | |
1887 | return tp->snd_nxt; | |
1888 | ||
a47e5a98 IJ |
1889 | return TCP_SKB_CB(tp->highest_sack)->seq; |
1890 | } | |
1891 | ||
6859d494 IJ |
1892 | static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) |
1893 | { | |
50895b9d | 1894 | tcp_sk(sk)->highest_sack = skb_rb_next(skb); |
6859d494 IJ |
1895 | } |
1896 | ||
1897 | static inline struct sk_buff *tcp_highest_sack(struct sock *sk) | |
1898 | { | |
1899 | return tcp_sk(sk)->highest_sack; | |
1900 | } | |
1901 | ||
1902 | static inline void tcp_highest_sack_reset(struct sock *sk) | |
1903 | { | |
50895b9d | 1904 | tcp_sk(sk)->highest_sack = tcp_rtx_queue_head(sk); |
6859d494 IJ |
1905 | } |
1906 | ||
2b7cda9c ED |
1907 | /* Called when old skb is about to be deleted and replaced by new skb */ |
1908 | static inline void tcp_highest_sack_replace(struct sock *sk, | |
6859d494 IJ |
1909 | struct sk_buff *old, |
1910 | struct sk_buff *new) | |
1911 | { | |
2b7cda9c | 1912 | if (old == tcp_highest_sack(sk)) |
6859d494 IJ |
1913 | tcp_sk(sk)->highest_sack = new; |
1914 | } | |
1915 | ||
b1f0a0e9 FW |
1916 | /* This helper checks if socket has IP_TRANSPARENT set */ |
1917 | static inline bool inet_sk_transparent(const struct sock *sk) | |
1918 | { | |
1919 | switch (sk->sk_state) { | |
1920 | case TCP_TIME_WAIT: | |
1921 | return inet_twsk(sk)->tw_transparent; | |
1922 | case TCP_NEW_SYN_RECV: | |
1923 | return inet_rsk(inet_reqsk(sk))->no_srccheck; | |
1924 | } | |
1925 | return inet_sk(sk)->transparent; | |
1926 | } | |
1927 | ||
5aa4b32f AP |
1928 | /* Determines whether this is a thin stream (which may suffer from |
1929 | * increased latency). Used to trigger latency-reducing mechanisms. | |
1930 | */ | |
a2a385d6 | 1931 | static inline bool tcp_stream_is_thin(struct tcp_sock *tp) |
5aa4b32f AP |
1932 | { |
1933 | return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); | |
1934 | } | |
1935 | ||
1da177e4 LT |
1936 | /* /proc */ |
1937 | enum tcp_seq_states { | |
1938 | TCP_SEQ_STATE_LISTENING, | |
1da177e4 | 1939 | TCP_SEQ_STATE_ESTABLISHED, |
1da177e4 LT |
1940 | }; |
1941 | ||
37d849bb CH |
1942 | void *tcp_seq_start(struct seq_file *seq, loff_t *pos); |
1943 | void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos); | |
1944 | void tcp_seq_stop(struct seq_file *seq, void *v); | |
73cb88ec | 1945 | |
1da177e4 | 1946 | struct tcp_seq_afinfo { |
73cb88ec | 1947 | sa_family_t family; |
1da177e4 LT |
1948 | }; |
1949 | ||
1950 | struct tcp_iter_state { | |
a4146b1b | 1951 | struct seq_net_private p; |
1da177e4 LT |
1952 | enum tcp_seq_states state; |
1953 | struct sock *syn_wait_sk; | |
b08d4d3b | 1954 | struct tcp_seq_afinfo *bpf_seq_afinfo; |
a7cb5a49 | 1955 | int bucket, offset, sbucket, num; |
a8b690f9 | 1956 | loff_t last_pos; |
1da177e4 LT |
1957 | }; |
1958 | ||
20380731 | 1959 | extern struct request_sock_ops tcp_request_sock_ops; |
c6aefafb | 1960 | extern struct request_sock_ops tcp6_request_sock_ops; |
20380731 | 1961 | |
5c9f3023 | 1962 | void tcp_v4_destroy_sock(struct sock *sk); |
20380731 | 1963 | |
28be6e07 | 1964 | struct sk_buff *tcp_gso_segment(struct sk_buff *skb, |
5c9f3023 | 1965 | netdev_features_t features); |
d4546c25 | 1966 | struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb); |
5521d95e ED |
1967 | INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *skb, int thoff)); |
1968 | INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)); | |
1969 | INDIRECT_CALLABLE_DECLARE(int tcp6_gro_complete(struct sk_buff *skb, int thoff)); | |
1970 | INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)); | |
5c9f3023 | 1971 | int tcp_gro_complete(struct sk_buff *skb); |
28850dc7 | 1972 | |
5c9f3023 | 1973 | void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); |
f4c50d99 | 1974 | |
c9bee3b7 ED |
1975 | static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) |
1976 | { | |
4979f2d9 NB |
1977 | struct net *net = sock_net((struct sock *)tp); |
1978 | return tp->notsent_lowat ?: net->ipv4.sysctl_tcp_notsent_lowat; | |
c9bee3b7 ED |
1979 | } |
1980 | ||
d3cd4924 | 1981 | bool tcp_stream_memory_free(const struct sock *sk, int wake); |
c9bee3b7 | 1982 | |
20380731 | 1983 | #ifdef CONFIG_PROC_FS |
5c9f3023 JP |
1984 | int tcp4_proc_init(void); |
1985 | void tcp4_proc_exit(void); | |
20380731 ACM |
1986 | #endif |
1987 | ||
ea3bea3a | 1988 | int tcp_rtx_synack(const struct sock *sk, struct request_sock *req); |
1fb6f159 OP |
1989 | int tcp_conn_request(struct request_sock_ops *rsk_ops, |
1990 | const struct tcp_request_sock_ops *af_ops, | |
1991 | struct sock *sk, struct sk_buff *skb); | |
5db92c99 | 1992 | |
cfb6eeb4 YH |
1993 | /* TCP af-specific functions */ |
1994 | struct tcp_sock_af_ops { | |
1995 | #ifdef CONFIG_TCP_MD5SIG | |
b83e3deb | 1996 | struct tcp_md5sig_key *(*md5_lookup) (const struct sock *sk, |
fd3a154a | 1997 | const struct sock *addr_sk); |
39f8e58e ED |
1998 | int (*calc_md5_hash)(char *location, |
1999 | const struct tcp_md5sig_key *md5, | |
2000 | const struct sock *sk, | |
2001 | const struct sk_buff *skb); | |
2002 | int (*md5_parse)(struct sock *sk, | |
8917a777 | 2003 | int optname, |
d4c19c49 | 2004 | sockptr_t optval, |
39f8e58e | 2005 | int optlen); |
cfb6eeb4 YH |
2006 | #endif |
2007 | }; | |
2008 | ||
2009 | struct tcp_request_sock_ops { | |
2aec4a29 | 2010 | u16 mss_clamp; |
cfb6eeb4 | 2011 | #ifdef CONFIG_TCP_MD5SIG |
b83e3deb | 2012 | struct tcp_md5sig_key *(*req_md5_lookup)(const struct sock *sk, |
fd3a154a | 2013 | const struct sock *addr_sk); |
39f8e58e ED |
2014 | int (*calc_md5_hash) (char *location, |
2015 | const struct tcp_md5sig_key *md5, | |
2016 | const struct sock *sk, | |
2017 | const struct sk_buff *skb); | |
cfb6eeb4 | 2018 | #endif |
fb7b37a7 | 2019 | #ifdef CONFIG_SYN_COOKIES |
3f684b4b | 2020 | __u32 (*cookie_init_seq)(const struct sk_buff *skb, |
fb7b37a7 OP |
2021 | __u16 *mss); |
2022 | #endif | |
7ea851d1 FW |
2023 | struct dst_entry *(*route_req)(const struct sock *sk, |
2024 | struct sk_buff *skb, | |
2025 | struct flowi *fl, | |
2026 | struct request_sock *req); | |
84b114b9 | 2027 | u32 (*init_seq)(const struct sk_buff *skb); |
5d2ed052 | 2028 | u32 (*init_ts_off)(const struct net *net, const struct sk_buff *skb); |
0f935dbe | 2029 | int (*send_synack)(const struct sock *sk, struct dst_entry *dst, |
d6274bd8 | 2030 | struct flowi *fl, struct request_sock *req, |
dc6ef6be | 2031 | struct tcp_fastopen_cookie *foc, |
331fca43 MKL |
2032 | enum tcp_synack_type synack_type, |
2033 | struct sk_buff *syn_skb); | |
cfb6eeb4 YH |
2034 | }; |
2035 | ||
35b2c321 MM |
2036 | extern const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops; |
2037 | #if IS_ENABLED(CONFIG_IPV6) | |
2038 | extern const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops; | |
2039 | #endif | |
2040 | ||
fb7b37a7 OP |
2041 | #ifdef CONFIG_SYN_COOKIES |
2042 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, | |
3f684b4b | 2043 | const struct sock *sk, struct sk_buff *skb, |
fb7b37a7 OP |
2044 | __u16 *mss) |
2045 | { | |
3f684b4b | 2046 | tcp_synq_overflow(sk); |
02a1d6e7 | 2047 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); |
3f684b4b | 2048 | return ops->cookie_init_seq(skb, mss); |
fb7b37a7 OP |
2049 | } |
2050 | #else | |
2051 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, | |
3f684b4b | 2052 | const struct sock *sk, struct sk_buff *skb, |
fb7b37a7 OP |
2053 | __u16 *mss) |
2054 | { | |
2055 | return 0; | |
2056 | } | |
2057 | #endif | |
2058 | ||
5c9f3023 | 2059 | int tcpv4_offload_init(void); |
28850dc7 | 2060 | |
5c9f3023 JP |
2061 | void tcp_v4_init(void); |
2062 | void tcp_init(void); | |
20380731 | 2063 | |
659a8ad5 | 2064 | /* tcp_recovery.c */ |
d716bfdb | 2065 | void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb); |
6ac06ecd | 2066 | void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced); |
b8fef65a YC |
2067 | extern s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, |
2068 | u32 reo_wnd); | |
62d9f1a6 | 2069 | extern bool tcp_rack_mark_lost(struct sock *sk); |
1d0833df | 2070 | extern void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, |
9a568de4 | 2071 | u64 xmit_time); |
57dde7f7 | 2072 | extern void tcp_rack_reo_timeout(struct sock *sk); |
1f255691 | 2073 | extern void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs); |
659a8ad5 | 2074 | |
e1a10ef7 NC |
2075 | /* At how many usecs into the future should the RTO fire? */ |
2076 | static inline s64 tcp_rto_delta_us(const struct sock *sk) | |
2077 | { | |
75c119af | 2078 | const struct sk_buff *skb = tcp_rtx_queue_head(sk); |
e1a10ef7 | 2079 | u32 rto = inet_csk(sk)->icsk_rto; |
2fd66ffb | 2080 | u64 rto_time_stamp_us = tcp_skb_timestamp_us(skb) + jiffies_to_usecs(rto); |
e1a10ef7 NC |
2081 | |
2082 | return rto_time_stamp_us - tcp_sk(sk)->tcp_mstamp; | |
2083 | } | |
2084 | ||
e25f866f CW |
2085 | /* |
2086 | * Save and compile IPv4 options, return a pointer to it | |
2087 | */ | |
91ed1e66 PA |
2088 | static inline struct ip_options_rcu *tcp_v4_save_options(struct net *net, |
2089 | struct sk_buff *skb) | |
e25f866f CW |
2090 | { |
2091 | const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; | |
2092 | struct ip_options_rcu *dopt = NULL; | |
2093 | ||
461b74c3 | 2094 | if (opt->optlen) { |
e25f866f CW |
2095 | int opt_size = sizeof(*dopt) + opt->optlen; |
2096 | ||
2097 | dopt = kmalloc(opt_size, GFP_ATOMIC); | |
91ed1e66 | 2098 | if (dopt && __ip_options_echo(net, &dopt->opt, skb, opt)) { |
e25f866f CW |
2099 | kfree(dopt); |
2100 | dopt = NULL; | |
2101 | } | |
2102 | } | |
2103 | return dopt; | |
2104 | } | |
2105 | ||
98781965 ED |
2106 | /* locally generated TCP pure ACKs have skb->truesize == 2 |
2107 | * (check tcp_send_ack() in net/ipv4/tcp_output.c ) | |
2108 | * This is much faster than dissecting the packet to find out. | |
2109 | * (Think of GRE encapsulations, IPv4, IPv6, ...) | |
2110 | */ | |
2111 | static inline bool skb_is_tcp_pure_ack(const struct sk_buff *skb) | |
2112 | { | |
2113 | return skb->truesize == 2; | |
2114 | } | |
2115 | ||
2116 | static inline void skb_set_tcp_pure_ack(struct sk_buff *skb) | |
2117 | { | |
2118 | skb->truesize = 2; | |
2119 | } | |
2120 | ||
473bd239 TH |
2121 | static inline int tcp_inq(struct sock *sk) |
2122 | { | |
2123 | struct tcp_sock *tp = tcp_sk(sk); | |
2124 | int answ; | |
2125 | ||
2126 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { | |
2127 | answ = 0; | |
2128 | } else if (sock_flag(sk, SOCK_URGINLINE) || | |
2129 | !tp->urg_data || | |
2130 | before(tp->urg_seq, tp->copied_seq) || | |
2131 | !before(tp->urg_seq, tp->rcv_nxt)) { | |
2132 | ||
2133 | answ = tp->rcv_nxt - tp->copied_seq; | |
2134 | ||
2135 | /* Subtract 1, if FIN was received */ | |
2136 | if (answ && sock_flag(sk, SOCK_DONE)) | |
2137 | answ--; | |
2138 | } else { | |
2139 | answ = tp->urg_seq - tp->copied_seq; | |
2140 | } | |
2141 | ||
2142 | return answ; | |
2143 | } | |
2144 | ||
32035585 TH |
2145 | int tcp_peek_len(struct socket *sock); |
2146 | ||
a44d6eac MKL |
2147 | static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) |
2148 | { | |
2149 | u16 segs_in; | |
2150 | ||
2151 | segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); | |
2152 | tp->segs_in += segs_in; | |
2153 | if (skb->len > tcp_hdrlen(skb)) | |
2154 | tp->data_segs_in += segs_in; | |
2155 | } | |
2156 | ||
9caad864 ED |
2157 | /* |
2158 | * TCP listen path runs lockless. | |
2159 | * We forced "struct sock" to be const qualified to make sure | |
2160 | * we don't modify one of its field by mistake. | |
2161 | * Here, we increment sk_drops which is an atomic_t, so we can safely | |
2162 | * make sock writable again. | |
2163 | */ | |
2164 | static inline void tcp_listendrop(const struct sock *sk) | |
2165 | { | |
2166 | atomic_inc(&((struct sock *)sk)->sk_drops); | |
02a1d6e7 | 2167 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); |
9caad864 ED |
2168 | } |
2169 | ||
218af599 ED |
2170 | enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer); |
2171 | ||
734942cc DW |
2172 | /* |
2173 | * Interface for adding Upper Level Protocols over TCP | |
2174 | */ | |
2175 | ||
2176 | #define TCP_ULP_NAME_MAX 16 | |
2177 | #define TCP_ULP_MAX 128 | |
2178 | #define TCP_ULP_BUF_MAX (TCP_ULP_NAME_MAX*TCP_ULP_MAX) | |
2179 | ||
2180 | struct tcp_ulp_ops { | |
2181 | struct list_head list; | |
2182 | ||
2183 | /* initialize ulp */ | |
2184 | int (*init)(struct sock *sk); | |
95fa1454 | 2185 | /* update ulp */ |
33bfe20d JF |
2186 | void (*update)(struct sock *sk, struct proto *p, |
2187 | void (*write_space)(struct sock *sk)); | |
734942cc DW |
2188 | /* cleanup ulp */ |
2189 | void (*release)(struct sock *sk); | |
61723b39 DC |
2190 | /* diagnostic */ |
2191 | int (*get_info)(const struct sock *sk, struct sk_buff *skb); | |
2192 | size_t (*get_info_size)(const struct sock *sk); | |
13230593 MM |
2193 | /* clone ulp */ |
2194 | void (*clone)(const struct request_sock *req, struct sock *newsk, | |
2195 | const gfp_t priority); | |
734942cc DW |
2196 | |
2197 | char name[TCP_ULP_NAME_MAX]; | |
2198 | struct module *owner; | |
2199 | }; | |
2200 | int tcp_register_ulp(struct tcp_ulp_ops *type); | |
2201 | void tcp_unregister_ulp(struct tcp_ulp_ops *type); | |
2202 | int tcp_set_ulp(struct sock *sk, const char *name); | |
2203 | void tcp_get_available_ulp(char *buf, size_t len); | |
2204 | void tcp_cleanup_ulp(struct sock *sk); | |
33bfe20d JF |
2205 | void tcp_update_ulp(struct sock *sk, struct proto *p, |
2206 | void (*write_space)(struct sock *sk)); | |
734942cc | 2207 | |
037b0b86 DB |
2208 | #define MODULE_ALIAS_TCP_ULP(name) \ |
2209 | __MODULE_INFO(alias, alias_userspace, name); \ | |
2210 | __MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name) | |
2211 | ||
88759609 | 2212 | #ifdef CONFIG_NET_SOCK_MSG |
604326b4 DB |
2213 | struct sk_msg; |
2214 | struct sk_psock; | |
2215 | ||
88759609 | 2216 | #ifdef CONFIG_BPF_SYSCALL |
f747632b | 2217 | struct proto *tcp_bpf_get_proto(struct sock *sk, struct sk_psock *psock); |
51e0158a | 2218 | int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore); |
f747632b | 2219 | void tcp_bpf_clone(const struct sock *sk, struct sock *newsk); |
88759609 | 2220 | #endif /* CONFIG_BPF_SYSCALL */ |
f747632b | 2221 | |
604326b4 DB |
2222 | int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg, u32 bytes, |
2223 | int flags); | |
5da00404 | 2224 | #endif /* CONFIG_NET_SOCK_MSG */ |
604326b4 | 2225 | |
88759609 CW |
2226 | #if !defined(CONFIG_BPF_SYSCALL) || !defined(CONFIG_NET_SOCK_MSG) |
2227 | static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk) | |
2228 | { | |
2229 | } | |
2230 | #endif | |
2231 | ||
0813a841 | 2232 | #ifdef CONFIG_CGROUP_BPF |
0813a841 MKL |
2233 | static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, |
2234 | struct sk_buff *skb, | |
2235 | unsigned int end_offset) | |
2236 | { | |
2237 | skops->skb = skb; | |
2238 | skops->skb_data_end = skb->data + end_offset; | |
2239 | } | |
2240 | #else | |
0813a841 MKL |
2241 | static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, |
2242 | struct sk_buff *skb, | |
2243 | unsigned int end_offset) | |
2244 | { | |
2245 | } | |
2246 | #endif | |
2247 | ||
40304b2a LB |
2248 | /* Call BPF_SOCK_OPS program that returns an int. If the return value |
2249 | * is < 0, then the BPF op failed (for example if the loaded BPF | |
2250 | * program does not support the chosen operation or there is no BPF | |
2251 | * program loaded). | |
2252 | */ | |
2253 | #ifdef CONFIG_BPF | |
de525be2 | 2254 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
40304b2a LB |
2255 | { |
2256 | struct bpf_sock_ops_kern sock_ops; | |
2257 | int ret; | |
2258 | ||
b73042b8 | 2259 | memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); |
f19397a5 LB |
2260 | if (sk_fullsock(sk)) { |
2261 | sock_ops.is_fullsock = 1; | |
40304b2a | 2262 | sock_owned_by_me(sk); |
f19397a5 | 2263 | } |
40304b2a | 2264 | |
40304b2a LB |
2265 | sock_ops.sk = sk; |
2266 | sock_ops.op = op; | |
de525be2 LB |
2267 | if (nargs > 0) |
2268 | memcpy(sock_ops.args, args, nargs * sizeof(*args)); | |
40304b2a LB |
2269 | |
2270 | ret = BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); | |
2271 | if (ret == 0) | |
2272 | ret = sock_ops.reply; | |
2273 | else | |
2274 | ret = -1; | |
2275 | return ret; | |
2276 | } | |
de525be2 LB |
2277 | |
2278 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) | |
2279 | { | |
2280 | u32 args[2] = {arg1, arg2}; | |
2281 | ||
2282 | return tcp_call_bpf(sk, op, 2, args); | |
2283 | } | |
2284 | ||
2285 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, | |
2286 | u32 arg3) | |
2287 | { | |
2288 | u32 args[3] = {arg1, arg2, arg3}; | |
2289 | ||
2290 | return tcp_call_bpf(sk, op, 3, args); | |
2291 | } | |
2292 | ||
40304b2a | 2293 | #else |
de525be2 | 2294 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
40304b2a LB |
2295 | { |
2296 | return -EPERM; | |
2297 | } | |
de525be2 LB |
2298 | |
2299 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) | |
2300 | { | |
2301 | return -EPERM; | |
2302 | } | |
2303 | ||
2304 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, | |
2305 | u32 arg3) | |
2306 | { | |
2307 | return -EPERM; | |
2308 | } | |
2309 | ||
40304b2a LB |
2310 | #endif |
2311 | ||
8550f328 LB |
2312 | static inline u32 tcp_timeout_init(struct sock *sk) |
2313 | { | |
2314 | int timeout; | |
2315 | ||
de525be2 | 2316 | timeout = tcp_call_bpf(sk, BPF_SOCK_OPS_TIMEOUT_INIT, 0, NULL); |
8550f328 LB |
2317 | |
2318 | if (timeout <= 0) | |
2319 | timeout = TCP_TIMEOUT_INIT; | |
2320 | return timeout; | |
2321 | } | |
2322 | ||
13d3b1eb LB |
2323 | static inline u32 tcp_rwnd_init_bpf(struct sock *sk) |
2324 | { | |
2325 | int rwnd; | |
2326 | ||
de525be2 | 2327 | rwnd = tcp_call_bpf(sk, BPF_SOCK_OPS_RWND_INIT, 0, NULL); |
13d3b1eb LB |
2328 | |
2329 | if (rwnd < 0) | |
2330 | rwnd = 0; | |
2331 | return rwnd; | |
2332 | } | |
91b5b21c LB |
2333 | |
2334 | static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) | |
2335 | { | |
de525be2 | 2336 | return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN, 0, NULL) == 1); |
91b5b21c | 2337 | } |
60e2a778 | 2338 | |
23729ff2 SF |
2339 | static inline void tcp_bpf_rtt(struct sock *sk) |
2340 | { | |
bef8e263 | 2341 | if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_RTT_CB_FLAG)) |
23729ff2 SF |
2342 | tcp_call_bpf(sk, BPF_SOCK_OPS_RTT_CB, 0, NULL); |
2343 | } | |
2344 | ||
60e2a778 UB |
2345 | #if IS_ENABLED(CONFIG_SMC) |
2346 | extern struct static_key_false tcp_have_smc; | |
2347 | #endif | |
6dac1523 IL |
2348 | |
2349 | #if IS_ENABLED(CONFIG_TLS_DEVICE) | |
2350 | void clean_acked_data_enable(struct inet_connection_sock *icsk, | |
2351 | void (*cad)(struct sock *sk, u32 ack_seq)); | |
2352 | void clean_acked_data_disable(struct inet_connection_sock *icsk); | |
494bc1d2 | 2353 | void clean_acked_data_flush(void); |
6dac1523 IL |
2354 | #endif |
2355 | ||
a842fe14 ED |
2356 | DECLARE_STATIC_KEY_FALSE(tcp_tx_delay_enabled); |
2357 | static inline void tcp_add_tx_delay(struct sk_buff *skb, | |
2358 | const struct tcp_sock *tp) | |
2359 | { | |
2360 | if (static_branch_unlikely(&tcp_tx_delay_enabled)) | |
2361 | skb->skb_mstamp_ns += (u64)tp->tcp_tx_delay * NSEC_PER_USEC; | |
2362 | } | |
2363 | ||
d6fb396c ED |
2364 | /* Compute Earliest Departure Time for some control packets |
2365 | * like ACK or RST for TIME_WAIT or non ESTABLISHED sockets. | |
2366 | */ | |
2367 | static inline u64 tcp_transmit_time(const struct sock *sk) | |
a842fe14 ED |
2368 | { |
2369 | if (static_branch_unlikely(&tcp_tx_delay_enabled)) { | |
2370 | u32 delay = (sk->sk_state == TCP_TIME_WAIT) ? | |
2371 | tcp_twsk(sk)->tw_tx_delay : tcp_sk(sk)->tcp_tx_delay; | |
2372 | ||
d6fb396c | 2373 | return tcp_clock_ns() + (u64)delay * NSEC_PER_USEC; |
a842fe14 | 2374 | } |
d6fb396c | 2375 | return 0; |
a842fe14 ED |
2376 | } |
2377 | ||
1da177e4 | 2378 | #endif /* _TCP_H */ |