1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
---|---|
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 | * |
11 | * Authors: Ross Biro |
12 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
13 | */ |
14 | #ifndef _TCP_H |
15 | #define _TCP_H |
16 | |
17 | #define FASTRETRANS_DEBUG 1 |
18 | |
19 | #include <linux/list.h> |
20 | #include <linux/tcp.h> |
21 | #include <linux/bug.h> |
22 | #include <linux/slab.h> |
23 | #include <linux/cache.h> |
24 | #include <linux/percpu.h> |
25 | #include <linux/skbuff.h> |
26 | #include <linux/kref.h> |
27 | #include <linux/ktime.h> |
28 | #include <linux/indirect_call_wrapper.h> |
29 | #include <linux/bits.h> |
30 | |
31 | #include <net/inet_connection_sock.h> |
32 | #include <net/inet_timewait_sock.h> |
33 | #include <net/inet_hashtables.h> |
34 | #include <net/checksum.h> |
35 | #include <net/request_sock.h> |
36 | #include <net/sock_reuseport.h> |
37 | #include <net/sock.h> |
38 | #include <net/snmp.h> |
39 | #include <net/ip.h> |
40 | #include <net/tcp_states.h> |
41 | #include <net/tcp_ao.h> |
42 | #include <net/inet_ecn.h> |
43 | #include <net/dst.h> |
44 | #include <net/mptcp.h> |
45 | #include <net/xfrm.h> |
46 | |
47 | #include <linux/seq_file.h> |
48 | #include <linux/memcontrol.h> |
49 | #include <linux/bpf-cgroup.h> |
50 | #include <linux/siphash.h> |
51 | |
52 | extern struct inet_hashinfo tcp_hashinfo; |
53 | |
54 | DECLARE_PER_CPU(unsigned int, tcp_orphan_count); |
55 | int tcp_orphan_count_sum(void); |
56 | |
57 | DECLARE_PER_CPU(u32, tcp_tw_isn); |
58 | |
59 | void tcp_time_wait(struct sock *sk, int state, int timeo); |
60 | |
61 | #define MAX_TCP_HEADER L1_CACHE_ALIGN(128 + MAX_HEADER) |
62 | #define MAX_TCP_OPTION_SPACE 40 |
63 | #define TCP_MIN_SND_MSS 48 |
64 | #define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE) |
65 | |
66 | /* |
67 | * Never offer a window over 32767 without using window scaling. Some |
68 | * poor stacks do signed 16bit maths! |
69 | */ |
70 | #define MAX_TCP_WINDOW 32767U |
71 | |
72 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ |
73 | #define TCP_MIN_MSS 88U |
74 | |
75 | /* The initial MTU to use for probing */ |
76 | #define TCP_BASE_MSS 1024 |
77 | |
78 | /* probing interval, default to 10 minutes as per RFC4821 */ |
79 | #define TCP_PROBE_INTERVAL 600 |
80 | |
81 | /* Specify interval when tcp mtu probing will stop */ |
82 | #define TCP_PROBE_THRESHOLD 8 |
83 | |
84 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
85 | #define TCP_FASTRETRANS_THRESH 3 |
86 | |
87 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
88 | #define TCP_MAX_QUICKACKS 16U |
89 | |
90 | /* Maximal number of window scale according to RFC1323 */ |
91 | #define TCP_MAX_WSCALE 14U |
92 | |
93 | /* urg_data states */ |
94 | #define TCP_URG_VALID 0x0100 |
95 | #define TCP_URG_NOTYET 0x0200 |
96 | #define TCP_URG_READ 0x0400 |
97 | |
98 | #define TCP_RETR1 3 /* |
99 | * This is how many retries it does before it |
100 | * tries to figure out if the gateway is |
101 | * down. Minimal RFC value is 3; it corresponds |
102 | * to ~3sec-8min depending on RTO. |
103 | */ |
104 | |
105 | #define TCP_RETR2 15 /* |
106 | * This should take at least |
107 | * 90 minutes to time out. |
108 | * RFC1122 says that the limit is 100 sec. |
109 | * 15 is ~13-30min depending on RTO. |
110 | */ |
111 | |
112 | #define TCP_SYN_RETRIES 6 /* This is how many retries are done |
113 | * when active opening a connection. |
114 | * RFC1122 says the minimum retry MUST |
115 | * be at least 180secs. Nevertheless |
116 | * this value is corresponding to |
117 | * 63secs of retransmission with the |
118 | * current initial RTO. |
119 | */ |
120 | |
121 | #define TCP_SYNACK_RETRIES 5 /* This is how may retries are done |
122 | * when passive opening a connection. |
123 | * This is corresponding to 31secs of |
124 | * retransmission with the current |
125 | * initial RTO. |
126 | */ |
127 | |
128 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
129 | * state, about 60 seconds */ |
130 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN |
131 | /* BSD style FIN_WAIT2 deadlock breaker. |
132 | * It used to be 3min, new value is 60sec, |
133 | * to combine FIN-WAIT-2 timeout with |
134 | * TIME-WAIT timer. |
135 | */ |
136 | #define TCP_FIN_TIMEOUT_MAX (120 * HZ) /* max TCP_LINGER2 value (two minutes) */ |
137 | |
138 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ |
139 | static_assert((1 << ATO_BITS) > TCP_DELACK_MAX); |
140 | |
141 | #if HZ >= 100 |
142 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ |
143 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) |
144 | #else |
145 | #define TCP_DELACK_MIN 4U |
146 | #define TCP_ATO_MIN 4U |
147 | #endif |
148 | #define TCP_RTO_MAX_SEC 120 |
149 | #define TCP_RTO_MAX ((unsigned)(TCP_RTO_MAX_SEC * HZ)) |
150 | #define TCP_RTO_MIN ((unsigned)(HZ / 5)) |
151 | #define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ |
152 | |
153 | #define TCP_TIMEOUT_MIN_US (2*USEC_PER_MSEC) /* Min TCP timeout in microsecs */ |
154 | |
155 | #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ |
156 | #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now |
157 | * used as a fallback RTO for the |
158 | * initial data transmission if no |
159 | * valid RTT sample has been acquired, |
160 | * most likely due to retrans in 3WHS. |
161 | */ |
162 | |
163 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes |
164 | * for local resources. |
165 | */ |
166 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
167 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ |
168 | #define TCP_KEEPALIVE_INTVL (75*HZ) |
169 | |
170 | #define MAX_TCP_KEEPIDLE 32767 |
171 | #define MAX_TCP_KEEPINTVL 32767 |
172 | #define MAX_TCP_KEEPCNT 127 |
173 | #define MAX_TCP_SYNCNT 127 |
174 | |
175 | /* Ensure that TCP PAWS checks are relaxed after ~2147 seconds |
176 | * to avoid overflows. This assumes a clock smaller than 1 Mhz. |
177 | * Default clock is 1 Khz, tcp_usec_ts uses 1 Mhz. |
178 | */ |
179 | #define TCP_PAWS_WRAP (INT_MAX / USEC_PER_SEC) |
180 | |
181 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated |
182 | * after this time. It should be equal |
183 | * (or greater than) TCP_TIMEWAIT_LEN |
184 | * to provide reliability equal to one |
185 | * provided by timewait state. |
186 | */ |
187 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host |
188 | * timestamps. It must be less than |
189 | * minimal timewait lifetime. |
190 | */ |
191 | /* |
192 | * TCP option |
193 | */ |
194 | |
195 | #define TCPOPT_NOP 1 /* Padding */ |
196 | #define TCPOPT_EOL 0 /* End of options */ |
197 | #define TCPOPT_MSS 2 /* Segment size negotiating */ |
198 | #define TCPOPT_WINDOW 3 /* Window scaling */ |
199 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ |
200 | #define TCPOPT_SACK 5 /* SACK Block */ |
201 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ |
202 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
203 | #define TCPOPT_AO 29 /* Authentication Option (RFC5925) */ |
204 | #define TCPOPT_MPTCP 30 /* Multipath TCP (RFC6824) */ |
205 | #define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ |
206 | #define TCPOPT_EXP 254 /* Experimental */ |
207 | /* Magic number to be after the option value for sharing TCP |
208 | * experimental options. See draft-ietf-tcpm-experimental-options-00.txt |
209 | */ |
210 | #define TCPOPT_FASTOPEN_MAGIC 0xF989 |
211 | #define TCPOPT_SMC_MAGIC 0xE2D4C3D9 |
212 | |
213 | /* |
214 | * TCP option lengths |
215 | */ |
216 | |
217 | #define TCPOLEN_MSS 4 |
218 | #define TCPOLEN_WINDOW 3 |
219 | #define TCPOLEN_SACK_PERM 2 |
220 | #define TCPOLEN_TIMESTAMP 10 |
221 | #define TCPOLEN_MD5SIG 18 |
222 | #define TCPOLEN_FASTOPEN_BASE 2 |
223 | #define TCPOLEN_EXP_FASTOPEN_BASE 4 |
224 | #define TCPOLEN_EXP_SMC_BASE 6 |
225 | |
226 | /* But this is what stacks really send out. */ |
227 | #define TCPOLEN_TSTAMP_ALIGNED 12 |
228 | #define TCPOLEN_WSCALE_ALIGNED 4 |
229 | #define TCPOLEN_SACKPERM_ALIGNED 4 |
230 | #define TCPOLEN_SACK_BASE 2 |
231 | #define TCPOLEN_SACK_BASE_ALIGNED 4 |
232 | #define TCPOLEN_SACK_PERBLOCK 8 |
233 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
234 | #define TCPOLEN_MSS_ALIGNED 4 |
235 | #define TCPOLEN_EXP_SMC_BASE_ALIGNED 8 |
236 | |
237 | /* Flags in tp->nonagle */ |
238 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ |
239 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ |
240 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
241 | |
242 | /* TCP thin-stream limits */ |
243 | #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ |
244 | |
245 | /* TCP initial congestion window as per rfc6928 */ |
246 | #define TCP_INIT_CWND 10 |
247 | |
248 | /* Bit Flags for sysctl_tcp_fastopen */ |
249 | #define TFO_CLIENT_ENABLE 1 |
250 | #define TFO_SERVER_ENABLE 2 |
251 | #define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ |
252 | |
253 | /* Accept SYN data w/o any cookie option */ |
254 | #define TFO_SERVER_COOKIE_NOT_REQD 0x200 |
255 | |
256 | /* Force enable TFO on all listeners, i.e., not requiring the |
257 | * TCP_FASTOPEN socket option. |
258 | */ |
259 | #define TFO_SERVER_WO_SOCKOPT1 0x400 |
260 | |
261 | |
262 | /* sysctl variables for tcp */ |
263 | extern int sysctl_tcp_max_orphans; |
264 | extern long sysctl_tcp_mem[3]; |
265 | |
266 | #define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ |
267 | #define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */ |
268 | #define TCP_RACK_NO_DUPTHRESH 0x4 /* Do not use DUPACK threshold in RACK */ |
269 | |
270 | extern atomic_long_t tcp_memory_allocated; |
271 | DECLARE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc); |
272 | |
273 | extern struct percpu_counter tcp_sockets_allocated; |
274 | extern unsigned long tcp_memory_pressure; |
275 | |
276 | /* optimized version of sk_under_memory_pressure() for TCP sockets */ |
277 | static inline bool tcp_under_memory_pressure(const struct sock *sk) |
278 | { |
279 | if (mem_cgroup_sockets_enabled && sk->sk_memcg && |
280 | mem_cgroup_under_socket_pressure(memcg: sk->sk_memcg)) |
281 | return true; |
282 | |
283 | return READ_ONCE(tcp_memory_pressure); |
284 | } |
285 | /* |
286 | * The next routines deal with comparing 32 bit unsigned ints |
287 | * and worry about wraparound (automatic with unsigned arithmetic). |
288 | */ |
289 | |
290 | static inline bool before(__u32 seq1, __u32 seq2) |
291 | { |
292 | return (__s32)(seq1-seq2) < 0; |
293 | } |
294 | #define after(seq2, seq1) before(seq1, seq2) |
295 | |
296 | /* is s2<=s1<=s3 ? */ |
297 | static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) |
298 | { |
299 | return seq3 - seq2 >= seq1 - seq2; |
300 | } |
301 | |
302 | static inline void tcp_wmem_free_skb(struct sock *sk, struct sk_buff *skb) |
303 | { |
304 | sk_wmem_queued_add(sk, val: -skb->truesize); |
305 | if (!skb_zcopy_pure(skb)) |
306 | sk_mem_uncharge(sk, size: skb->truesize); |
307 | else |
308 | sk_mem_uncharge(sk, SKB_TRUESIZE(skb_end_offset(skb))); |
309 | __kfree_skb(skb); |
310 | } |
311 | |
312 | void sk_forced_mem_schedule(struct sock *sk, int size); |
313 | |
314 | bool tcp_check_oom(const struct sock *sk, int shift); |
315 | |
316 | |
317 | extern struct proto tcp_prot; |
318 | |
319 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
320 | #define __TCP_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
321 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) |
322 | #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) |
323 | |
324 | void tcp_tasklet_init(void); |
325 | |
326 | int tcp_v4_err(struct sk_buff *skb, u32); |
327 | |
328 | void tcp_shutdown(struct sock *sk, int how); |
329 | |
330 | int tcp_v4_early_demux(struct sk_buff *skb); |
331 | int tcp_v4_rcv(struct sk_buff *skb); |
332 | |
333 | void tcp_remove_empty_skb(struct sock *sk); |
334 | int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); |
335 | int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size); |
336 | int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied, |
337 | size_t size, struct ubuf_info *uarg); |
338 | void tcp_splice_eof(struct socket *sock); |
339 | int tcp_send_mss(struct sock *sk, int *size_goal, int flags); |
340 | int tcp_wmem_schedule(struct sock *sk, int copy); |
341 | void tcp_push(struct sock *sk, int flags, int mss_now, int nonagle, |
342 | int size_goal); |
343 | void tcp_release_cb(struct sock *sk); |
344 | void tcp_wfree(struct sk_buff *skb); |
345 | void tcp_write_timer_handler(struct sock *sk); |
346 | void tcp_delack_timer_handler(struct sock *sk); |
347 | int tcp_ioctl(struct sock *sk, int cmd, int *karg); |
348 | enum skb_drop_reason tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); |
349 | void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); |
350 | void tcp_rcv_space_adjust(struct sock *sk); |
351 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); |
352 | void tcp_twsk_destructor(struct sock *sk); |
353 | void tcp_twsk_purge(struct list_head *net_exit_list); |
354 | ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, |
355 | struct pipe_inode_info *pipe, size_t len, |
356 | unsigned int flags); |
357 | struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, gfp_t gfp, |
358 | bool force_schedule); |
359 | |
360 | static inline void tcp_dec_quickack_mode(struct sock *sk) |
361 | { |
362 | struct inet_connection_sock *icsk = inet_csk(sk); |
363 | |
364 | if (icsk->icsk_ack.quick) { |
365 | /* How many ACKs S/ACKing new data have we sent? */ |
366 | const unsigned int pkts = inet_csk_ack_scheduled(sk) ? 1 : 0; |
367 | |
368 | if (pkts >= icsk->icsk_ack.quick) { |
369 | icsk->icsk_ack.quick = 0; |
370 | /* Leaving quickack mode we deflate ATO. */ |
371 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
372 | } else |
373 | icsk->icsk_ack.quick -= pkts; |
374 | } |
375 | } |
376 | |
377 | #define TCP_ECN_MODE_RFC3168 BIT(0) |
378 | #define TCP_ECN_QUEUE_CWR BIT(1) |
379 | #define TCP_ECN_DEMAND_CWR BIT(2) |
380 | #define TCP_ECN_SEEN BIT(3) |
381 | #define TCP_ECN_MODE_ACCECN BIT(4) |
382 | |
383 | #define TCP_ECN_DISABLED 0 |
384 | #define TCP_ECN_MODE_PENDING (TCP_ECN_MODE_RFC3168 | TCP_ECN_MODE_ACCECN) |
385 | #define TCP_ECN_MODE_ANY (TCP_ECN_MODE_RFC3168 | TCP_ECN_MODE_ACCECN) |
386 | |
387 | static inline bool tcp_ecn_mode_any(const struct tcp_sock *tp) |
388 | { |
389 | return tp->ecn_flags & TCP_ECN_MODE_ANY; |
390 | } |
391 | |
392 | static inline bool tcp_ecn_mode_rfc3168(const struct tcp_sock *tp) |
393 | { |
394 | return (tp->ecn_flags & TCP_ECN_MODE_ANY) == TCP_ECN_MODE_RFC3168; |
395 | } |
396 | |
397 | static inline bool tcp_ecn_mode_accecn(const struct tcp_sock *tp) |
398 | { |
399 | return (tp->ecn_flags & TCP_ECN_MODE_ANY) == TCP_ECN_MODE_ACCECN; |
400 | } |
401 | |
402 | static inline bool tcp_ecn_disabled(const struct tcp_sock *tp) |
403 | { |
404 | return !tcp_ecn_mode_any(tp); |
405 | } |
406 | |
407 | static inline bool tcp_ecn_mode_pending(const struct tcp_sock *tp) |
408 | { |
409 | return (tp->ecn_flags & TCP_ECN_MODE_PENDING) == TCP_ECN_MODE_PENDING; |
410 | } |
411 | |
412 | static inline void tcp_ecn_mode_set(struct tcp_sock *tp, u8 mode) |
413 | { |
414 | tp->ecn_flags &= ~TCP_ECN_MODE_ANY; |
415 | tp->ecn_flags |= mode; |
416 | } |
417 | |
418 | enum tcp_tw_status { |
419 | TCP_TW_SUCCESS = 0, |
420 | TCP_TW_RST = 1, |
421 | TCP_TW_ACK = 2, |
422 | TCP_TW_SYN = 3, |
423 | TCP_TW_ACK_OOW = 4 |
424 | }; |
425 | |
426 | |
427 | enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
428 | struct sk_buff *skb, |
429 | const struct tcphdr *th, |
430 | u32 *tw_isn, |
431 | enum skb_drop_reason *drop_reason); |
432 | struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, |
433 | struct request_sock *req, bool fastopen, |
434 | bool *lost_race, enum skb_drop_reason *drop_reason); |
435 | enum skb_drop_reason tcp_child_process(struct sock *parent, struct sock *child, |
436 | struct sk_buff *skb); |
437 | void tcp_enter_loss(struct sock *sk); |
438 | void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int newly_lost, int flag); |
439 | void tcp_clear_retrans(struct tcp_sock *tp); |
440 | void tcp_update_metrics(struct sock *sk); |
441 | void tcp_init_metrics(struct sock *sk); |
442 | void tcp_metrics_init(void); |
443 | bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst); |
444 | void __tcp_close(struct sock *sk, long timeout); |
445 | void tcp_close(struct sock *sk, long timeout); |
446 | void tcp_init_sock(struct sock *sk); |
447 | void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb); |
448 | __poll_t tcp_poll(struct file *file, struct socket *sock, |
449 | struct poll_table_struct *wait); |
450 | int do_tcp_getsockopt(struct sock *sk, int level, |
451 | int optname, sockptr_t optval, sockptr_t optlen); |
452 | int tcp_getsockopt(struct sock *sk, int level, int optname, |
453 | char __user *optval, int __user *optlen); |
454 | bool tcp_bpf_bypass_getsockopt(int level, int optname); |
455 | int do_tcp_setsockopt(struct sock *sk, int level, int optname, |
456 | sockptr_t optval, unsigned int optlen); |
457 | int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, |
458 | unsigned int optlen); |
459 | void tcp_reset_keepalive_timer(struct sock *sk, unsigned long timeout); |
460 | void tcp_set_keepalive(struct sock *sk, int val); |
461 | void tcp_syn_ack_timeout(const struct request_sock *req); |
462 | int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
463 | int flags, int *addr_len); |
464 | int tcp_set_rcvlowat(struct sock *sk, int val); |
465 | int tcp_set_window_clamp(struct sock *sk, int val); |
466 | void tcp_update_recv_tstamps(struct sk_buff *skb, |
467 | struct scm_timestamping_internal *tss); |
468 | void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, |
469 | struct scm_timestamping_internal *tss); |
470 | void tcp_data_ready(struct sock *sk); |
471 | #ifdef CONFIG_MMU |
472 | int tcp_mmap(struct file *file, struct socket *sock, |
473 | struct vm_area_struct *vma); |
474 | #endif |
475 | void tcp_parse_options(const struct net *net, const struct sk_buff *skb, |
476 | struct tcp_options_received *opt_rx, |
477 | int estab, struct tcp_fastopen_cookie *foc); |
478 | |
479 | /* |
480 | * BPF SKB-less helpers |
481 | */ |
482 | u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, |
483 | struct tcphdr *th, u32 *cookie); |
484 | u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, |
485 | struct tcphdr *th, u32 *cookie); |
486 | u16 tcp_parse_mss_option(const struct tcphdr *th, u16 user_mss); |
487 | u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, |
488 | const struct tcp_request_sock_ops *af_ops, |
489 | struct sock *sk, struct tcphdr *th); |
490 | /* |
491 | * TCP v4 functions exported for the inet6 API |
492 | */ |
493 | |
494 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
495 | void tcp_v4_mtu_reduced(struct sock *sk); |
496 | void tcp_req_err(struct sock *sk, u32 seq, bool abort); |
497 | void tcp_ld_RTO_revert(struct sock *sk, u32 seq); |
498 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); |
499 | struct sock *tcp_create_openreq_child(const struct sock *sk, |
500 | struct request_sock *req, |
501 | struct sk_buff *skb); |
502 | void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); |
503 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
504 | struct request_sock *req, |
505 | struct dst_entry *dst, |
506 | struct request_sock *req_unhash, |
507 | bool *own_req); |
508 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); |
509 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); |
510 | int tcp_connect(struct sock *sk); |
511 | enum tcp_synack_type { |
512 | TCP_SYNACK_NORMAL, |
513 | TCP_SYNACK_FASTOPEN, |
514 | TCP_SYNACK_COOKIE, |
515 | }; |
516 | struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, |
517 | struct request_sock *req, |
518 | struct tcp_fastopen_cookie *foc, |
519 | enum tcp_synack_type synack_type, |
520 | struct sk_buff *syn_skb); |
521 | int tcp_disconnect(struct sock *sk, int flags); |
522 | |
523 | void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); |
524 | int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); |
525 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); |
526 | |
527 | /* From syncookies.c */ |
528 | struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, |
529 | struct request_sock *req, |
530 | struct dst_entry *dst); |
531 | int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th); |
532 | struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); |
533 | struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, |
534 | struct sock *sk, struct sk_buff *skb, |
535 | struct tcp_options_received *tcp_opt, |
536 | int mss, u32 tsoff); |
537 | |
538 | #if IS_ENABLED(CONFIG_BPF) |
539 | struct bpf_tcp_req_attrs { |
540 | u32 rcv_tsval; |
541 | u32 rcv_tsecr; |
542 | u16 mss; |
543 | u8 rcv_wscale; |
544 | u8 snd_wscale; |
545 | u8 ecn_ok; |
546 | u8 wscale_ok; |
547 | u8 sack_ok; |
548 | u8 tstamp_ok; |
549 | u8 usec_ts_ok; |
550 | u8 reserved[3]; |
551 | }; |
552 | #endif |
553 | |
554 | #ifdef CONFIG_SYN_COOKIES |
555 | |
556 | /* Syncookies use a monotonic timer which increments every 60 seconds. |
557 | * This counter is used both as a hash input and partially encoded into |
558 | * the cookie value. A cookie is only validated further if the delta |
559 | * between the current counter value and the encoded one is less than this, |
560 | * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if |
561 | * the counter advances immediately after a cookie is generated). |
562 | */ |
563 | #define MAX_SYNCOOKIE_AGE 2 |
564 | #define TCP_SYNCOOKIE_PERIOD (60 * HZ) |
565 | #define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) |
566 | |
567 | /* syncookies: remember time of last synqueue overflow |
568 | * But do not dirty this field too often (once per second is enough) |
569 | * It is racy as we do not hold a lock, but race is very minor. |
570 | */ |
571 | static inline void tcp_synq_overflow(const struct sock *sk) |
572 | { |
573 | unsigned int last_overflow; |
574 | unsigned int now = jiffies; |
575 | |
576 | if (sk->sk_reuseport) { |
577 | struct sock_reuseport *reuse; |
578 | |
579 | reuse = rcu_dereference(sk->sk_reuseport_cb); |
580 | if (likely(reuse)) { |
581 | last_overflow = READ_ONCE(reuse->synq_overflow_ts); |
582 | if (!time_between32(now, last_overflow, |
583 | last_overflow + HZ)) |
584 | WRITE_ONCE(reuse->synq_overflow_ts, now); |
585 | return; |
586 | } |
587 | } |
588 | |
589 | last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); |
590 | if (!time_between32(now, last_overflow, last_overflow + HZ)) |
591 | WRITE_ONCE(tcp_sk_rw(sk)->rx_opt.ts_recent_stamp, now); |
592 | } |
593 | |
594 | /* syncookies: no recent synqueue overflow on this listening socket? */ |
595 | static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) |
596 | { |
597 | unsigned int last_overflow; |
598 | unsigned int now = jiffies; |
599 | |
600 | if (sk->sk_reuseport) { |
601 | struct sock_reuseport *reuse; |
602 | |
603 | reuse = rcu_dereference(sk->sk_reuseport_cb); |
604 | if (likely(reuse)) { |
605 | last_overflow = READ_ONCE(reuse->synq_overflow_ts); |
606 | return !time_between32(now, last_overflow - HZ, |
607 | last_overflow + |
608 | TCP_SYNCOOKIE_VALID); |
609 | } |
610 | } |
611 | |
612 | last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); |
613 | |
614 | /* If last_overflow <= jiffies <= last_overflow + TCP_SYNCOOKIE_VALID, |
615 | * then we're under synflood. However, we have to use |
616 | * 'last_overflow - HZ' as lower bound. That's because a concurrent |
617 | * tcp_synq_overflow() could update .ts_recent_stamp after we read |
618 | * jiffies but before we store .ts_recent_stamp into last_overflow, |
619 | * which could lead to rejecting a valid syncookie. |
620 | */ |
621 | return !time_between32(now, last_overflow - HZ, |
622 | last_overflow + TCP_SYNCOOKIE_VALID); |
623 | } |
624 | |
625 | static inline u32 tcp_cookie_time(void) |
626 | { |
627 | u64 val = get_jiffies_64(); |
628 | |
629 | do_div(val, TCP_SYNCOOKIE_PERIOD); |
630 | return val; |
631 | } |
632 | |
633 | /* Convert one nsec 64bit timestamp to ts (ms or usec resolution) */ |
634 | static inline u64 tcp_ns_to_ts(bool usec_ts, u64 val) |
635 | { |
636 | if (usec_ts) |
637 | return div_u64(dividend: val, NSEC_PER_USEC); |
638 | |
639 | return div_u64(dividend: val, NSEC_PER_MSEC); |
640 | } |
641 | |
642 | u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, |
643 | u16 *mssp); |
644 | __u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); |
645 | u64 cookie_init_timestamp(struct request_sock *req, u64 now); |
646 | bool cookie_timestamp_decode(const struct net *net, |
647 | struct tcp_options_received *opt); |
648 | |
649 | static inline bool cookie_ecn_ok(const struct net *net, const struct dst_entry *dst) |
650 | { |
651 | return READ_ONCE(net->ipv4.sysctl_tcp_ecn) || |
652 | dst_feature(dst, RTAX_FEATURE_ECN); |
653 | } |
654 | |
655 | #if IS_ENABLED(CONFIG_BPF) |
656 | static inline bool cookie_bpf_ok(struct sk_buff *skb) |
657 | { |
658 | return skb->sk; |
659 | } |
660 | |
661 | struct request_sock *cookie_bpf_check(struct sock *sk, struct sk_buff *skb); |
662 | #else |
663 | static inline bool cookie_bpf_ok(struct sk_buff *skb) |
664 | { |
665 | return false; |
666 | } |
667 | |
668 | static inline struct request_sock *cookie_bpf_check(struct net *net, struct sock *sk, |
669 | struct sk_buff *skb) |
670 | { |
671 | return NULL; |
672 | } |
673 | #endif |
674 | |
675 | /* From net/ipv6/syncookies.c */ |
676 | int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th); |
677 | struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); |
678 | |
679 | u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, |
680 | const struct tcphdr *th, u16 *mssp); |
681 | __u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); |
682 | #endif |
683 | /* tcp_output.c */ |
684 | |
685 | void tcp_skb_entail(struct sock *sk, struct sk_buff *skb); |
686 | void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb); |
687 | void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
688 | int nonagle); |
689 | int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
690 | int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
691 | void tcp_retransmit_timer(struct sock *sk); |
692 | void tcp_xmit_retransmit_queue(struct sock *); |
693 | void tcp_simple_retransmit(struct sock *); |
694 | void tcp_enter_recovery(struct sock *sk, bool ece_ack); |
695 | int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
696 | enum tcp_queue { |
697 | TCP_FRAG_IN_WRITE_QUEUE, |
698 | TCP_FRAG_IN_RTX_QUEUE, |
699 | }; |
700 | int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, |
701 | struct sk_buff *skb, u32 len, |
702 | unsigned int mss_now, gfp_t gfp); |
703 | |
704 | void tcp_send_probe0(struct sock *); |
705 | int tcp_write_wakeup(struct sock *, int mib); |
706 | void tcp_send_fin(struct sock *sk); |
707 | void tcp_send_active_reset(struct sock *sk, gfp_t priority, |
708 | enum sk_rst_reason reason); |
709 | int tcp_send_synack(struct sock *); |
710 | void tcp_push_one(struct sock *, unsigned int mss_now); |
711 | void __tcp_send_ack(struct sock *sk, u32 rcv_nxt, u16 flags); |
712 | void tcp_send_ack(struct sock *sk); |
713 | void tcp_send_delayed_ack(struct sock *sk); |
714 | void tcp_send_loss_probe(struct sock *sk); |
715 | bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto); |
716 | void tcp_skb_collapse_tstamp(struct sk_buff *skb, |
717 | const struct sk_buff *next_skb); |
718 | |
719 | /* tcp_input.c */ |
720 | void tcp_rearm_rto(struct sock *sk); |
721 | void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); |
722 | void tcp_done_with_error(struct sock *sk, int err); |
723 | void tcp_reset(struct sock *sk, struct sk_buff *skb); |
724 | void tcp_fin(struct sock *sk); |
725 | void tcp_check_space(struct sock *sk); |
726 | void tcp_sack_compress_send_ack(struct sock *sk); |
727 | |
728 | static inline void tcp_cleanup_skb(struct sk_buff *skb) |
729 | { |
730 | skb_dst_drop(skb); |
731 | secpath_reset(skb); |
732 | } |
733 | |
734 | static inline void tcp_add_receive_queue(struct sock *sk, struct sk_buff *skb) |
735 | { |
736 | DEBUG_NET_WARN_ON_ONCE(skb_dst(skb)); |
737 | DEBUG_NET_WARN_ON_ONCE(secpath_exists(skb)); |
738 | __skb_queue_tail(list: &sk->sk_receive_queue, newsk: skb); |
739 | } |
740 | |
741 | /* tcp_timer.c */ |
742 | void tcp_init_xmit_timers(struct sock *); |
743 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
744 | { |
745 | if (hrtimer_try_to_cancel(timer: &tcp_sk(sk)->pacing_timer) == 1) |
746 | __sock_put(sk); |
747 | |
748 | if (hrtimer_try_to_cancel(timer: &tcp_sk(sk)->compressed_ack_timer) == 1) |
749 | __sock_put(sk); |
750 | |
751 | inet_csk_clear_xmit_timers(sk); |
752 | } |
753 | |
754 | unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
755 | unsigned int tcp_current_mss(struct sock *sk); |
756 | u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when); |
757 | |
758 | /* Bound MSS / TSO packet size with the half of the window */ |
759 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) |
760 | { |
761 | int cutoff; |
762 | |
763 | /* When peer uses tiny windows, there is no use in packetizing |
764 | * to sub-MSS pieces for the sake of SWS or making sure there |
765 | * are enough packets in the pipe for fast recovery. |
766 | * |
767 | * On the other hand, for extremely large MSS devices, handling |
768 | * smaller than MSS windows in this way does make sense. |
769 | */ |
770 | if (tp->max_window > TCP_MSS_DEFAULT) |
771 | cutoff = (tp->max_window >> 1); |
772 | else |
773 | cutoff = tp->max_window; |
774 | |
775 | if (cutoff && pktsize > cutoff) |
776 | return max_t(int, cutoff, 68U - tp->tcp_header_len); |
777 | else |
778 | return pktsize; |
779 | } |
780 | |
781 | /* tcp.c */ |
782 | void tcp_get_info(struct sock *, struct tcp_info *); |
783 | |
784 | /* Read 'sendfile()'-style from a TCP socket */ |
785 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
786 | sk_read_actor_t recv_actor); |
787 | int tcp_read_sock_noack(struct sock *sk, read_descriptor_t *desc, |
788 | sk_read_actor_t recv_actor, bool noack, |
789 | u32 *copied_seq); |
790 | int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor); |
791 | struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off); |
792 | void tcp_read_done(struct sock *sk, size_t len); |
793 | |
794 | void tcp_initialize_rcv_mss(struct sock *sk); |
795 | |
796 | int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
797 | int tcp_mss_to_mtu(struct sock *sk, int mss); |
798 | void tcp_mtup_init(struct sock *sk); |
799 | |
800 | static inline unsigned int tcp_rto_max(const struct sock *sk) |
801 | { |
802 | return READ_ONCE(inet_csk(sk)->icsk_rto_max); |
803 | } |
804 | |
805 | static inline void tcp_bound_rto(struct sock *sk) |
806 | { |
807 | inet_csk(sk)->icsk_rto = min(inet_csk(sk)->icsk_rto, tcp_rto_max(sk)); |
808 | } |
809 | |
810 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) |
811 | { |
812 | return usecs_to_jiffies(u: (tp->srtt_us >> 3) + tp->rttvar_us); |
813 | } |
814 | |
815 | static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
816 | { |
817 | /* mptcp hooks are only on the slow path */ |
818 | if (sk_is_mptcp(sk: (struct sock *)tp)) |
819 | return; |
820 | |
821 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | |
822 | ntohl(TCP_FLAG_ACK) | |
823 | snd_wnd); |
824 | } |
825 | |
826 | static inline void tcp_fast_path_on(struct tcp_sock *tp) |
827 | { |
828 | __tcp_fast_path_on(tp, snd_wnd: tp->snd_wnd >> tp->rx_opt.snd_wscale); |
829 | } |
830 | |
831 | static inline void tcp_fast_path_check(struct sock *sk) |
832 | { |
833 | struct tcp_sock *tp = tcp_sk(sk); |
834 | |
835 | if (RB_EMPTY_ROOT(&tp->out_of_order_queue) && |
836 | tp->rcv_wnd && |
837 | atomic_read(v: &sk->sk_rmem_alloc) < sk->sk_rcvbuf && |
838 | !tp->urg_data) |
839 | tcp_fast_path_on(tp); |
840 | } |
841 | |
842 | u32 tcp_delack_max(const struct sock *sk); |
843 | |
844 | /* Compute the actual rto_min value */ |
845 | static inline u32 tcp_rto_min(const struct sock *sk) |
846 | { |
847 | const struct dst_entry *dst = __sk_dst_get(sk); |
848 | u32 rto_min = READ_ONCE(inet_csk(sk)->icsk_rto_min); |
849 | |
850 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) |
851 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); |
852 | return rto_min; |
853 | } |
854 | |
855 | static inline u32 tcp_rto_min_us(const struct sock *sk) |
856 | { |
857 | return jiffies_to_usecs(j: tcp_rto_min(sk)); |
858 | } |
859 | |
860 | static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) |
861 | { |
862 | return dst_metric_locked(dst, RTAX_CC_ALGO); |
863 | } |
864 | |
865 | /* Minimum RTT in usec. ~0 means not available. */ |
866 | static inline u32 tcp_min_rtt(const struct tcp_sock *tp) |
867 | { |
868 | return minmax_get(m: &tp->rtt_min); |
869 | } |
870 | |
871 | /* Compute the actual receive window we are currently advertising. |
872 | * Rcv_nxt can be after the window if our peer push more data |
873 | * than the offered window. |
874 | */ |
875 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
876 | { |
877 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; |
878 | |
879 | if (win < 0) |
880 | win = 0; |
881 | return (u32) win; |
882 | } |
883 | |
884 | /* Choose a new window, without checks for shrinking, and without |
885 | * scaling applied to the result. The caller does these things |
886 | * if necessary. This is a "raw" window selection. |
887 | */ |
888 | u32 __tcp_select_window(struct sock *sk); |
889 | |
890 | void tcp_send_window_probe(struct sock *sk); |
891 | |
892 | /* TCP uses 32bit jiffies to save some space. |
893 | * Note that this is different from tcp_time_stamp, which |
894 | * historically has been the same until linux-4.13. |
895 | */ |
896 | #define tcp_jiffies32 ((u32)jiffies) |
897 | |
898 | /* |
899 | * Deliver a 32bit value for TCP timestamp option (RFC 7323) |
900 | * It is no longer tied to jiffies, but to 1 ms clock. |
901 | * Note: double check if you want to use tcp_jiffies32 instead of this. |
902 | */ |
903 | #define TCP_TS_HZ 1000 |
904 | |
905 | static inline u64 tcp_clock_ns(void) |
906 | { |
907 | return ktime_get_ns(); |
908 | } |
909 | |
910 | static inline u64 tcp_clock_us(void) |
911 | { |
912 | return div_u64(dividend: tcp_clock_ns(), NSEC_PER_USEC); |
913 | } |
914 | |
915 | static inline u64 tcp_clock_ms(void) |
916 | { |
917 | return div_u64(dividend: tcp_clock_ns(), NSEC_PER_MSEC); |
918 | } |
919 | |
920 | /* TCP Timestamp included in TS option (RFC 1323) can either use ms |
921 | * or usec resolution. Each socket carries a flag to select one or other |
922 | * resolution, as the route attribute could change anytime. |
923 | * Each flow must stick to initial resolution. |
924 | */ |
925 | static inline u32 tcp_clock_ts(bool usec_ts) |
926 | { |
927 | return usec_ts ? tcp_clock_us() : tcp_clock_ms(); |
928 | } |
929 | |
930 | static inline u32 tcp_time_stamp_ms(const struct tcp_sock *tp) |
931 | { |
932 | return div_u64(dividend: tp->tcp_mstamp, USEC_PER_MSEC); |
933 | } |
934 | |
935 | static inline u32 tcp_time_stamp_ts(const struct tcp_sock *tp) |
936 | { |
937 | if (tp->tcp_usec_ts) |
938 | return tp->tcp_mstamp; |
939 | return tcp_time_stamp_ms(tp); |
940 | } |
941 | |
942 | void tcp_mstamp_refresh(struct tcp_sock *tp); |
943 | |
944 | static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) |
945 | { |
946 | return max_t(s64, t1 - t0, 0); |
947 | } |
948 | |
949 | /* provide the departure time in us unit */ |
950 | static inline u64 tcp_skb_timestamp_us(const struct sk_buff *skb) |
951 | { |
952 | return div_u64(dividend: skb->skb_mstamp_ns, NSEC_PER_USEC); |
953 | } |
954 | |
955 | /* Provide skb TSval in usec or ms unit */ |
956 | static inline u32 tcp_skb_timestamp_ts(bool usec_ts, const struct sk_buff *skb) |
957 | { |
958 | if (usec_ts) |
959 | return tcp_skb_timestamp_us(skb); |
960 | |
961 | return div_u64(dividend: skb->skb_mstamp_ns, NSEC_PER_MSEC); |
962 | } |
963 | |
964 | static inline u32 tcp_tw_tsval(const struct tcp_timewait_sock *tcptw) |
965 | { |
966 | return tcp_clock_ts(usec_ts: tcptw->tw_sk.tw_usec_ts) + tcptw->tw_ts_offset; |
967 | } |
968 | |
969 | static inline u32 tcp_rsk_tsval(const struct tcp_request_sock *treq) |
970 | { |
971 | return tcp_clock_ts(usec_ts: treq->req_usec_ts) + treq->ts_off; |
972 | } |
973 | |
974 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
975 | |
976 | #define TCPHDR_FIN BIT(0) |
977 | #define TCPHDR_SYN BIT(1) |
978 | #define TCPHDR_RST BIT(2) |
979 | #define TCPHDR_PSH BIT(3) |
980 | #define TCPHDR_ACK BIT(4) |
981 | #define TCPHDR_URG BIT(5) |
982 | #define TCPHDR_ECE BIT(6) |
983 | #define TCPHDR_CWR BIT(7) |
984 | #define TCPHDR_AE BIT(8) |
985 | #define TCPHDR_FLAGS_MASK (TCPHDR_FIN | TCPHDR_SYN | TCPHDR_RST | \ |
986 | TCPHDR_PSH | TCPHDR_ACK | TCPHDR_URG | \ |
987 | TCPHDR_ECE | TCPHDR_CWR | TCPHDR_AE) |
988 | #define tcp_flags_ntohs(th) (ntohs(*(__be16 *)&tcp_flag_word(th)) & \ |
989 | TCPHDR_FLAGS_MASK) |
990 | |
991 | #define TCPHDR_ACE (TCPHDR_ECE | TCPHDR_CWR | TCPHDR_AE) |
992 | #define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) |
993 | |
994 | /* State flags for sacked in struct tcp_skb_cb */ |
995 | enum tcp_skb_cb_sacked_flags { |
996 | TCPCB_SACKED_ACKED = (1 << 0), /* SKB ACK'd by a SACK block */ |
997 | TCPCB_SACKED_RETRANS = (1 << 1), /* SKB retransmitted */ |
998 | TCPCB_LOST = (1 << 2), /* SKB is lost */ |
999 | TCPCB_TAGBITS = (TCPCB_SACKED_ACKED | TCPCB_SACKED_RETRANS | |
1000 | TCPCB_LOST), /* All tag bits */ |
1001 | TCPCB_REPAIRED = (1 << 4), /* SKB repaired (no skb_mstamp_ns) */ |
1002 | TCPCB_EVER_RETRANS = (1 << 7), /* Ever retransmitted frame */ |
1003 | TCPCB_RETRANS = (TCPCB_SACKED_RETRANS | TCPCB_EVER_RETRANS | |
1004 | TCPCB_REPAIRED), |
1005 | }; |
1006 | |
1007 | /* This is what the send packet queuing engine uses to pass |
1008 | * TCP per-packet control information to the transmission code. |
1009 | * We also store the host-order sequence numbers in here too. |
1010 | * This is 44 bytes if IPV6 is enabled. |
1011 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. |
1012 | */ |
1013 | struct tcp_skb_cb { |
1014 | __u32 seq; /* Starting sequence number */ |
1015 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ |
1016 | union { |
1017 | /* Note : |
1018 | * tcp_gso_segs/size are used in write queue only, |
1019 | * cf tcp_skb_pcount()/tcp_skb_mss() |
1020 | */ |
1021 | struct { |
1022 | u16 tcp_gso_segs; |
1023 | u16 tcp_gso_size; |
1024 | }; |
1025 | }; |
1026 | __u16 tcp_flags; /* TCP header flags (tcp[12-13])*/ |
1027 | |
1028 | __u8 sacked; /* State flags for SACK. */ |
1029 | __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ |
1030 | #define TSTAMP_ACK_SK 0x1 |
1031 | #define TSTAMP_ACK_BPF 0x2 |
1032 | __u8 txstamp_ack:2, /* Record TX timestamp for ack? */ |
1033 | eor:1, /* Is skb MSG_EOR marked? */ |
1034 | has_rxtstamp:1, /* SKB has a RX timestamp */ |
1035 | unused:4; |
1036 | __u32 ack_seq; /* Sequence number ACK'd */ |
1037 | union { |
1038 | struct { |
1039 | #define TCPCB_DELIVERED_CE_MASK ((1U<<20) - 1) |
1040 | /* There is space for up to 24 bytes */ |
1041 | __u32 is_app_limited:1, /* cwnd not fully used? */ |
1042 | delivered_ce:20, |
1043 | unused:11; |
1044 | /* pkts S/ACKed so far upon tx of skb, incl retrans: */ |
1045 | __u32 delivered; |
1046 | /* start of send pipeline phase */ |
1047 | u64 first_tx_mstamp; |
1048 | /* when we reached the "delivered" count */ |
1049 | u64 delivered_mstamp; |
1050 | } tx; /* only used for outgoing skbs */ |
1051 | union { |
1052 | struct inet_skb_parm h4; |
1053 | #if IS_ENABLED(CONFIG_IPV6) |
1054 | struct inet6_skb_parm h6; |
1055 | #endif |
1056 | } header; /* For incoming skbs */ |
1057 | }; |
1058 | }; |
1059 | |
1060 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) |
1061 | |
1062 | extern const struct inet_connection_sock_af_ops ipv4_specific; |
1063 | |
1064 | #if IS_ENABLED(CONFIG_IPV6) |
1065 | /* This is the variant of inet6_iif() that must be used by TCP, |
1066 | * as TCP moves IP6CB into a different location in skb->cb[] |
1067 | */ |
1068 | static inline int tcp_v6_iif(const struct sk_buff *skb) |
1069 | { |
1070 | return TCP_SKB_CB(skb)->header.h6.iif; |
1071 | } |
1072 | |
1073 | static inline int tcp_v6_iif_l3_slave(const struct sk_buff *skb) |
1074 | { |
1075 | bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); |
1076 | |
1077 | return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; |
1078 | } |
1079 | |
1080 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
1081 | static inline int tcp_v6_sdif(const struct sk_buff *skb) |
1082 | { |
1083 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
1084 | if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags)) |
1085 | return TCP_SKB_CB(skb)->header.h6.iif; |
1086 | #endif |
1087 | return 0; |
1088 | } |
1089 | |
1090 | extern const struct inet_connection_sock_af_ops ipv6_specific; |
1091 | |
1092 | INDIRECT_CALLABLE_DECLARE(void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)); |
1093 | INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *skb)); |
1094 | void tcp_v6_early_demux(struct sk_buff *skb); |
1095 | |
1096 | #endif |
1097 | |
1098 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
1099 | static inline int tcp_v4_sdif(struct sk_buff *skb) |
1100 | { |
1101 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
1102 | if (skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) |
1103 | return TCP_SKB_CB(skb)->header.h4.iif; |
1104 | #endif |
1105 | return 0; |
1106 | } |
1107 | |
1108 | /* Due to TSO, an SKB can be composed of multiple actual |
1109 | * packets. To keep these tracked properly, we use this. |
1110 | */ |
1111 | static inline int tcp_skb_pcount(const struct sk_buff *skb) |
1112 | { |
1113 | return TCP_SKB_CB(skb)->tcp_gso_segs; |
1114 | } |
1115 | |
1116 | static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) |
1117 | { |
1118 | TCP_SKB_CB(skb)->tcp_gso_segs = segs; |
1119 | } |
1120 | |
1121 | static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) |
1122 | { |
1123 | TCP_SKB_CB(skb)->tcp_gso_segs += segs; |
1124 | } |
1125 | |
1126 | /* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ |
1127 | static inline int tcp_skb_mss(const struct sk_buff *skb) |
1128 | { |
1129 | return TCP_SKB_CB(skb)->tcp_gso_size; |
1130 | } |
1131 | |
1132 | static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) |
1133 | { |
1134 | return likely(!TCP_SKB_CB(skb)->eor); |
1135 | } |
1136 | |
1137 | static inline bool tcp_skb_can_collapse(const struct sk_buff *to, |
1138 | const struct sk_buff *from) |
1139 | { |
1140 | /* skb_cmp_decrypted() not needed, use tcp_write_collapse_fence() */ |
1141 | return likely(tcp_skb_can_collapse_to(to) && |
1142 | mptcp_skb_can_collapse(to, from) && |
1143 | skb_pure_zcopy_same(to, from) && |
1144 | skb_frags_readable(to) == skb_frags_readable(from)); |
1145 | } |
1146 | |
1147 | static inline bool tcp_skb_can_collapse_rx(const struct sk_buff *to, |
1148 | const struct sk_buff *from) |
1149 | { |
1150 | return likely(mptcp_skb_can_collapse(to, from) && |
1151 | !skb_cmp_decrypted(to, from)); |
1152 | } |
1153 | |
1154 | /* Events passed to congestion control interface */ |
1155 | enum tcp_ca_event { |
1156 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ |
1157 | CA_EVENT_CWND_RESTART, /* congestion window restart */ |
1158 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ |
1159 | CA_EVENT_LOSS, /* loss timeout */ |
1160 | CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ |
1161 | CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ |
1162 | }; |
1163 | |
1164 | /* Information about inbound ACK, passed to cong_ops->in_ack_event() */ |
1165 | enum tcp_ca_ack_event_flags { |
1166 | CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ |
1167 | CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ |
1168 | CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ |
1169 | }; |
1170 | |
1171 | /* |
1172 | * Interface for adding new TCP congestion control handlers |
1173 | */ |
1174 | #define TCP_CA_NAME_MAX 16 |
1175 | #define TCP_CA_MAX 128 |
1176 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) |
1177 | |
1178 | #define TCP_CA_UNSPEC 0 |
1179 | |
1180 | /* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ |
1181 | #define TCP_CONG_NON_RESTRICTED BIT(0) |
1182 | /* Requires ECN/ECT set on all packets */ |
1183 | #define TCP_CONG_NEEDS_ECN BIT(1) |
1184 | #define TCP_CONG_MASK (TCP_CONG_NON_RESTRICTED | TCP_CONG_NEEDS_ECN) |
1185 | |
1186 | union tcp_cc_info; |
1187 | |
1188 | struct ack_sample { |
1189 | u32 pkts_acked; |
1190 | s32 rtt_us; |
1191 | u32 in_flight; |
1192 | }; |
1193 | |
1194 | /* A rate sample measures the number of (original/retransmitted) data |
1195 | * packets delivered "delivered" over an interval of time "interval_us". |
1196 | * The tcp_rate.c code fills in the rate sample, and congestion |
1197 | * control modules that define a cong_control function to run at the end |
1198 | * of ACK processing can optionally chose to consult this sample when |
1199 | * setting cwnd and pacing rate. |
1200 | * A sample is invalid if "delivered" or "interval_us" is negative. |
1201 | */ |
1202 | struct rate_sample { |
1203 | u64 prior_mstamp; /* starting timestamp for interval */ |
1204 | u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ |
1205 | u32 prior_delivered_ce;/* tp->delivered_ce at "prior_mstamp" */ |
1206 | s32 delivered; /* number of packets delivered over interval */ |
1207 | s32 delivered_ce; /* number of packets delivered w/ CE marks*/ |
1208 | long interval_us; /* time for tp->delivered to incr "delivered" */ |
1209 | u32 snd_interval_us; /* snd interval for delivered packets */ |
1210 | u32 rcv_interval_us; /* rcv interval for delivered packets */ |
1211 | long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ |
1212 | int losses; /* number of packets marked lost upon ACK */ |
1213 | u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ |
1214 | u32 prior_in_flight; /* in flight before this ACK */ |
1215 | u32 last_end_seq; /* end_seq of most recently ACKed packet */ |
1216 | bool is_app_limited; /* is sample from packet with bubble in pipe? */ |
1217 | bool is_retrans; /* is sample from retransmission? */ |
1218 | bool is_ack_delayed; /* is this (likely) a delayed ACK? */ |
1219 | }; |
1220 | |
1221 | struct tcp_congestion_ops { |
1222 | /* fast path fields are put first to fill one cache line */ |
1223 | |
1224 | /* return slow start threshold (required) */ |
1225 | u32 (*ssthresh)(struct sock *sk); |
1226 | |
1227 | /* do new cwnd calculation (required) */ |
1228 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); |
1229 | |
1230 | /* call before changing ca_state (optional) */ |
1231 | void (*set_state)(struct sock *sk, u8 new_state); |
1232 | |
1233 | /* call when cwnd event occurs (optional) */ |
1234 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
1235 | |
1236 | /* call when ack arrives (optional) */ |
1237 | void (*in_ack_event)(struct sock *sk, u32 flags); |
1238 | |
1239 | /* hook for packet ack accounting (optional) */ |
1240 | void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); |
1241 | |
1242 | /* override sysctl_tcp_min_tso_segs */ |
1243 | u32 (*min_tso_segs)(struct sock *sk); |
1244 | |
1245 | /* call when packets are delivered to update cwnd and pacing rate, |
1246 | * after all the ca_state processing. (optional) |
1247 | */ |
1248 | void (*cong_control)(struct sock *sk, u32 ack, int flag, const struct rate_sample *rs); |
1249 | |
1250 | |
1251 | /* new value of cwnd after loss (required) */ |
1252 | u32 (*undo_cwnd)(struct sock *sk); |
1253 | /* returns the multiplier used in tcp_sndbuf_expand (optional) */ |
1254 | u32 (*sndbuf_expand)(struct sock *sk); |
1255 | |
1256 | /* control/slow paths put last */ |
1257 | /* get info for inet_diag (optional) */ |
1258 | size_t (*get_info)(struct sock *sk, u32 ext, int *attr, |
1259 | union tcp_cc_info *info); |
1260 | |
1261 | char name[TCP_CA_NAME_MAX]; |
1262 | struct module *owner; |
1263 | struct list_head list; |
1264 | u32 key; |
1265 | u32 flags; |
1266 | |
1267 | /* initialize private data (optional) */ |
1268 | void (*init)(struct sock *sk); |
1269 | /* cleanup private data (optional) */ |
1270 | void (*release)(struct sock *sk); |
1271 | } ____cacheline_aligned_in_smp; |
1272 | |
1273 | int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
1274 | void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); |
1275 | int tcp_update_congestion_control(struct tcp_congestion_ops *type, |
1276 | struct tcp_congestion_ops *old_type); |
1277 | int tcp_validate_congestion_control(struct tcp_congestion_ops *ca); |
1278 | |
1279 | void tcp_assign_congestion_control(struct sock *sk); |
1280 | void tcp_init_congestion_control(struct sock *sk); |
1281 | void tcp_cleanup_congestion_control(struct sock *sk); |
1282 | int tcp_set_default_congestion_control(struct net *net, const char *name); |
1283 | void tcp_get_default_congestion_control(struct net *net, char *name); |
1284 | void tcp_get_available_congestion_control(char *buf, size_t len); |
1285 | void tcp_get_allowed_congestion_control(char *buf, size_t len); |
1286 | int tcp_set_allowed_congestion_control(char *allowed); |
1287 | int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, |
1288 | bool cap_net_admin); |
1289 | u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); |
1290 | void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); |
1291 | |
1292 | u32 tcp_reno_ssthresh(struct sock *sk); |
1293 | u32 tcp_reno_undo_cwnd(struct sock *sk); |
1294 | void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); |
1295 | extern struct tcp_congestion_ops tcp_reno; |
1296 | |
1297 | struct tcp_congestion_ops *tcp_ca_find(const char *name); |
1298 | struct tcp_congestion_ops *tcp_ca_find_key(u32 key); |
1299 | u32 tcp_ca_get_key_by_name(const char *name, bool *ecn_ca); |
1300 | #ifdef CONFIG_INET |
1301 | char *tcp_ca_get_name_by_key(u32 key, char *buffer); |
1302 | #else |
1303 | static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) |
1304 | { |
1305 | return NULL; |
1306 | } |
1307 | #endif |
1308 | |
1309 | static inline bool tcp_ca_needs_ecn(const struct sock *sk) |
1310 | { |
1311 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1312 | |
1313 | return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; |
1314 | } |
1315 | |
1316 | static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) |
1317 | { |
1318 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1319 | |
1320 | if (icsk->icsk_ca_ops->cwnd_event) |
1321 | icsk->icsk_ca_ops->cwnd_event(sk, event); |
1322 | } |
1323 | |
1324 | /* From tcp_cong.c */ |
1325 | void tcp_set_ca_state(struct sock *sk, const u8 ca_state); |
1326 | |
1327 | /* From tcp_rate.c */ |
1328 | void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); |
1329 | void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, |
1330 | struct rate_sample *rs); |
1331 | void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, |
1332 | bool is_sack_reneg, struct rate_sample *rs); |
1333 | void tcp_rate_check_app_limited(struct sock *sk); |
1334 | |
1335 | static inline bool tcp_skb_sent_after(u64 t1, u64 t2, u32 seq1, u32 seq2) |
1336 | { |
1337 | return t1 > t2 || (t1 == t2 && after(seq1, seq2)); |
1338 | } |
1339 | |
1340 | /* These functions determine how the current flow behaves in respect of SACK |
1341 | * handling. SACK is negotiated with the peer, and therefore it can vary |
1342 | * between different flows. |
1343 | * |
1344 | * tcp_is_sack - SACK enabled |
1345 | * tcp_is_reno - No SACK |
1346 | */ |
1347 | static inline int tcp_is_sack(const struct tcp_sock *tp) |
1348 | { |
1349 | return likely(tp->rx_opt.sack_ok); |
1350 | } |
1351 | |
1352 | static inline bool tcp_is_reno(const struct tcp_sock *tp) |
1353 | { |
1354 | return !tcp_is_sack(tp); |
1355 | } |
1356 | |
1357 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
1358 | { |
1359 | return tp->sacked_out + tp->lost_out; |
1360 | } |
1361 | |
1362 | /* This determines how many packets are "in the network" to the best |
1363 | * of our knowledge. In many cases it is conservative, but where |
1364 | * detailed information is available from the receiver (via SACK |
1365 | * blocks etc.) we can make more aggressive calculations. |
1366 | * |
1367 | * Use this for decisions involving congestion control, use just |
1368 | * tp->packets_out to determine if the send queue is empty or not. |
1369 | * |
1370 | * Read this equation as: |
1371 | * |
1372 | * "Packets sent once on transmission queue" MINUS |
1373 | * "Packets left network, but not honestly ACKed yet" PLUS |
1374 | * "Packets fast retransmitted" |
1375 | */ |
1376 | static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
1377 | { |
1378 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
1379 | } |
1380 | |
1381 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
1382 | |
1383 | static inline u32 tcp_snd_cwnd(const struct tcp_sock *tp) |
1384 | { |
1385 | return tp->snd_cwnd; |
1386 | } |
1387 | |
1388 | static inline void tcp_snd_cwnd_set(struct tcp_sock *tp, u32 val) |
1389 | { |
1390 | WARN_ON_ONCE((int)val <= 0); |
1391 | tp->snd_cwnd = val; |
1392 | } |
1393 | |
1394 | static inline bool tcp_in_slow_start(const struct tcp_sock *tp) |
1395 | { |
1396 | return tcp_snd_cwnd(tp) < tp->snd_ssthresh; |
1397 | } |
1398 | |
1399 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) |
1400 | { |
1401 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; |
1402 | } |
1403 | |
1404 | static inline bool tcp_in_cwnd_reduction(const struct sock *sk) |
1405 | { |
1406 | return (TCPF_CA_CWR | TCPF_CA_Recovery) & |
1407 | (1 << inet_csk(sk)->icsk_ca_state); |
1408 | } |
1409 | |
1410 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
1411 | * The exception is cwnd reduction phase, when cwnd is decreasing towards |
1412 | * ssthresh. |
1413 | */ |
1414 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
1415 | { |
1416 | const struct tcp_sock *tp = tcp_sk(sk); |
1417 | |
1418 | if (tcp_in_cwnd_reduction(sk)) |
1419 | return tp->snd_ssthresh; |
1420 | else |
1421 | return max(tp->snd_ssthresh, |
1422 | ((tcp_snd_cwnd(tp) >> 1) + |
1423 | (tcp_snd_cwnd(tp) >> 2))); |
1424 | } |
1425 | |
1426 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
1427 | #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) |
1428 | |
1429 | void tcp_enter_cwr(struct sock *sk); |
1430 | __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); |
1431 | |
1432 | /* The maximum number of MSS of available cwnd for which TSO defers |
1433 | * sending if not using sysctl_tcp_tso_win_divisor. |
1434 | */ |
1435 | static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) |
1436 | { |
1437 | return 3; |
1438 | } |
1439 | |
1440 | /* Returns end sequence number of the receiver's advertised window */ |
1441 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) |
1442 | { |
1443 | return tp->snd_una + tp->snd_wnd; |
1444 | } |
1445 | |
1446 | /* We follow the spirit of RFC2861 to validate cwnd but implement a more |
1447 | * flexible approach. The RFC suggests cwnd should not be raised unless |
1448 | * it was fully used previously. And that's exactly what we do in |
1449 | * congestion avoidance mode. But in slow start we allow cwnd to grow |
1450 | * as long as the application has used half the cwnd. |
1451 | * Example : |
1452 | * cwnd is 10 (IW10), but application sends 9 frames. |
1453 | * We allow cwnd to reach 18 when all frames are ACKed. |
1454 | * This check is safe because it's as aggressive as slow start which already |
1455 | * risks 100% overshoot. The advantage is that we discourage application to |
1456 | * either send more filler packets or data to artificially blow up the cwnd |
1457 | * usage, and allow application-limited process to probe bw more aggressively. |
1458 | */ |
1459 | static inline bool tcp_is_cwnd_limited(const struct sock *sk) |
1460 | { |
1461 | const struct tcp_sock *tp = tcp_sk(sk); |
1462 | |
1463 | if (tp->is_cwnd_limited) |
1464 | return true; |
1465 | |
1466 | /* If in slow start, ensure cwnd grows to twice what was ACKed. */ |
1467 | if (tcp_in_slow_start(tp)) |
1468 | return tcp_snd_cwnd(tp) < 2 * tp->max_packets_out; |
1469 | |
1470 | return false; |
1471 | } |
1472 | |
1473 | /* BBR congestion control needs pacing. |
1474 | * Same remark for SO_MAX_PACING_RATE. |
1475 | * sch_fq packet scheduler is efficiently handling pacing, |
1476 | * but is not always installed/used. |
1477 | * Return true if TCP stack should pace packets itself. |
1478 | */ |
1479 | static inline bool tcp_needs_internal_pacing(const struct sock *sk) |
1480 | { |
1481 | return smp_load_acquire(&sk->sk_pacing_status) == SK_PACING_NEEDED; |
1482 | } |
1483 | |
1484 | /* Estimates in how many jiffies next packet for this flow can be sent. |
1485 | * Scheduling a retransmit timer too early would be silly. |
1486 | */ |
1487 | static inline unsigned long tcp_pacing_delay(const struct sock *sk) |
1488 | { |
1489 | s64 delay = tcp_sk(sk)->tcp_wstamp_ns - tcp_sk(sk)->tcp_clock_cache; |
1490 | |
1491 | return delay > 0 ? nsecs_to_jiffies(n: delay) : 0; |
1492 | } |
1493 | |
1494 | static inline void tcp_reset_xmit_timer(struct sock *sk, |
1495 | const int what, |
1496 | unsigned long when, |
1497 | bool pace_delay) |
1498 | { |
1499 | if (pace_delay) |
1500 | when += tcp_pacing_delay(sk); |
1501 | inet_csk_reset_xmit_timer(sk, what, when, |
1502 | max_when: tcp_rto_max(sk)); |
1503 | } |
1504 | |
1505 | /* Something is really bad, we could not queue an additional packet, |
1506 | * because qdisc is full or receiver sent a 0 window, or we are paced. |
1507 | * We do not want to add fuel to the fire, or abort too early, |
1508 | * so make sure the timer we arm now is at least 200ms in the future, |
1509 | * regardless of current icsk_rto value (as it could be ~2ms) |
1510 | */ |
1511 | static inline unsigned long tcp_probe0_base(const struct sock *sk) |
1512 | { |
1513 | return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); |
1514 | } |
1515 | |
1516 | /* Variant of inet_csk_rto_backoff() used for zero window probes */ |
1517 | static inline unsigned long tcp_probe0_when(const struct sock *sk, |
1518 | unsigned long max_when) |
1519 | { |
1520 | u8 backoff = min_t(u8, ilog2(TCP_RTO_MAX / TCP_RTO_MIN) + 1, |
1521 | inet_csk(sk)->icsk_backoff); |
1522 | u64 when = (u64)tcp_probe0_base(sk) << backoff; |
1523 | |
1524 | return (unsigned long)min_t(u64, when, max_when); |
1525 | } |
1526 | |
1527 | static inline void tcp_check_probe_timer(struct sock *sk) |
1528 | { |
1529 | if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) |
1530 | tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
1531 | when: tcp_probe0_base(sk), pace_delay: true); |
1532 | } |
1533 | |
1534 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
1535 | { |
1536 | tp->snd_wl1 = seq; |
1537 | } |
1538 | |
1539 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
1540 | { |
1541 | tp->snd_wl1 = seq; |
1542 | } |
1543 | |
1544 | /* |
1545 | * Calculate(/check) TCP checksum |
1546 | */ |
1547 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
1548 | __be32 daddr, __wsum base) |
1549 | { |
1550 | return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_TCP, sum: base); |
1551 | } |
1552 | |
1553 | static inline bool tcp_checksum_complete(struct sk_buff *skb) |
1554 | { |
1555 | return !skb_csum_unnecessary(skb) && |
1556 | __skb_checksum_complete(skb); |
1557 | } |
1558 | |
1559 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb, |
1560 | enum skb_drop_reason *reason); |
1561 | |
1562 | |
1563 | int tcp_filter(struct sock *sk, struct sk_buff *skb); |
1564 | void tcp_set_state(struct sock *sk, int state); |
1565 | void tcp_done(struct sock *sk); |
1566 | int tcp_abort(struct sock *sk, int err); |
1567 | |
1568 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
1569 | { |
1570 | rx_opt->dsack = 0; |
1571 | rx_opt->num_sacks = 0; |
1572 | } |
1573 | |
1574 | void tcp_cwnd_restart(struct sock *sk, s32 delta); |
1575 | |
1576 | static inline void tcp_slow_start_after_idle_check(struct sock *sk) |
1577 | { |
1578 | const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; |
1579 | struct tcp_sock *tp = tcp_sk(sk); |
1580 | s32 delta; |
1581 | |
1582 | if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle) || |
1583 | tp->packets_out || ca_ops->cong_control) |
1584 | return; |
1585 | delta = tcp_jiffies32 - tp->lsndtime; |
1586 | if (delta > inet_csk(sk)->icsk_rto) |
1587 | tcp_cwnd_restart(sk, delta); |
1588 | } |
1589 | |
1590 | /* Determine a window scaling and initial window to offer. */ |
1591 | void tcp_select_initial_window(const struct sock *sk, int __space, |
1592 | __u32 mss, __u32 *rcv_wnd, |
1593 | __u32 *window_clamp, int wscale_ok, |
1594 | __u8 *rcv_wscale, __u32 init_rcv_wnd); |
1595 | |
1596 | static inline int __tcp_win_from_space(u8 scaling_ratio, int space) |
1597 | { |
1598 | s64 scaled_space = (s64)space * scaling_ratio; |
1599 | |
1600 | return scaled_space >> TCP_RMEM_TO_WIN_SCALE; |
1601 | } |
1602 | |
1603 | static inline int tcp_win_from_space(const struct sock *sk, int space) |
1604 | { |
1605 | return __tcp_win_from_space(tcp_sk(sk)->scaling_ratio, space); |
1606 | } |
1607 | |
1608 | /* inverse of __tcp_win_from_space() */ |
1609 | static inline int __tcp_space_from_win(u8 scaling_ratio, int win) |
1610 | { |
1611 | u64 val = (u64)win << TCP_RMEM_TO_WIN_SCALE; |
1612 | |
1613 | do_div(val, scaling_ratio); |
1614 | return val; |
1615 | } |
1616 | |
1617 | static inline int tcp_space_from_win(const struct sock *sk, int win) |
1618 | { |
1619 | return __tcp_space_from_win(tcp_sk(sk)->scaling_ratio, win); |
1620 | } |
1621 | |
1622 | /* Assume a 50% default for skb->len/skb->truesize ratio. |
1623 | * This may be adjusted later in tcp_measure_rcv_mss(). |
1624 | */ |
1625 | #define TCP_DEFAULT_SCALING_RATIO (1 << (TCP_RMEM_TO_WIN_SCALE - 1)) |
1626 | |
1627 | static inline void tcp_scaling_ratio_init(struct sock *sk) |
1628 | { |
1629 | tcp_sk(sk)->scaling_ratio = TCP_DEFAULT_SCALING_RATIO; |
1630 | } |
1631 | |
1632 | /* Note: caller must be prepared to deal with negative returns */ |
1633 | static inline int tcp_space(const struct sock *sk) |
1634 | { |
1635 | return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - |
1636 | READ_ONCE(sk->sk_backlog.len) - |
1637 | atomic_read(v: &sk->sk_rmem_alloc)); |
1638 | } |
1639 | |
1640 | static inline int tcp_full_space(const struct sock *sk) |
1641 | { |
1642 | return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); |
1643 | } |
1644 | |
1645 | static inline void __tcp_adjust_rcv_ssthresh(struct sock *sk, u32 new_ssthresh) |
1646 | { |
1647 | int unused_mem = sk_unused_reserved_mem(sk); |
1648 | struct tcp_sock *tp = tcp_sk(sk); |
1649 | |
1650 | tp->rcv_ssthresh = min(tp->rcv_ssthresh, new_ssthresh); |
1651 | if (unused_mem) |
1652 | tp->rcv_ssthresh = max_t(u32, tp->rcv_ssthresh, |
1653 | tcp_win_from_space(sk, unused_mem)); |
1654 | } |
1655 | |
1656 | static inline void tcp_adjust_rcv_ssthresh(struct sock *sk) |
1657 | { |
1658 | __tcp_adjust_rcv_ssthresh(sk, new_ssthresh: 4U * tcp_sk(sk)->advmss); |
1659 | } |
1660 | |
1661 | void tcp_cleanup_rbuf(struct sock *sk, int copied); |
1662 | void __tcp_cleanup_rbuf(struct sock *sk, int copied); |
1663 | |
1664 | |
1665 | /* We provision sk_rcvbuf around 200% of sk_rcvlowat. |
1666 | * If 87.5 % (7/8) of the space has been consumed, we want to override |
1667 | * SO_RCVLOWAT constraint, since we are receiving skbs with too small |
1668 | * len/truesize ratio. |
1669 | */ |
1670 | static inline bool tcp_rmem_pressure(const struct sock *sk) |
1671 | { |
1672 | int rcvbuf, threshold; |
1673 | |
1674 | if (tcp_under_memory_pressure(sk)) |
1675 | return true; |
1676 | |
1677 | rcvbuf = READ_ONCE(sk->sk_rcvbuf); |
1678 | threshold = rcvbuf - (rcvbuf >> 3); |
1679 | |
1680 | return atomic_read(v: &sk->sk_rmem_alloc) > threshold; |
1681 | } |
1682 | |
1683 | static inline bool tcp_epollin_ready(const struct sock *sk, int target) |
1684 | { |
1685 | const struct tcp_sock *tp = tcp_sk(sk); |
1686 | int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); |
1687 | |
1688 | if (avail <= 0) |
1689 | return false; |
1690 | |
1691 | return (avail >= target) || tcp_rmem_pressure(sk) || |
1692 | (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss); |
1693 | } |
1694 | |
1695 | extern void tcp_openreq_init_rwin(struct request_sock *req, |
1696 | const struct sock *sk_listener, |
1697 | const struct dst_entry *dst); |
1698 | |
1699 | void tcp_enter_memory_pressure(struct sock *sk); |
1700 | void tcp_leave_memory_pressure(struct sock *sk); |
1701 | |
1702 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
1703 | { |
1704 | struct net *net = sock_net(sk: (struct sock *)tp); |
1705 | int val; |
1706 | |
1707 | /* Paired with WRITE_ONCE() in tcp_sock_set_keepintvl() |
1708 | * and do_tcp_setsockopt(). |
1709 | */ |
1710 | val = READ_ONCE(tp->keepalive_intvl); |
1711 | |
1712 | return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); |
1713 | } |
1714 | |
1715 | static inline int keepalive_time_when(const struct tcp_sock *tp) |
1716 | { |
1717 | struct net *net = sock_net(sk: (struct sock *)tp); |
1718 | int val; |
1719 | |
1720 | /* Paired with WRITE_ONCE() in tcp_sock_set_keepidle_locked() */ |
1721 | val = READ_ONCE(tp->keepalive_time); |
1722 | |
1723 | return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); |
1724 | } |
1725 | |
1726 | static inline int keepalive_probes(const struct tcp_sock *tp) |
1727 | { |
1728 | struct net *net = sock_net(sk: (struct sock *)tp); |
1729 | int val; |
1730 | |
1731 | /* Paired with WRITE_ONCE() in tcp_sock_set_keepcnt() |
1732 | * and do_tcp_setsockopt(). |
1733 | */ |
1734 | val = READ_ONCE(tp->keepalive_probes); |
1735 | |
1736 | return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes); |
1737 | } |
1738 | |
1739 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
1740 | { |
1741 | const struct inet_connection_sock *icsk = &tp->inet_conn; |
1742 | |
1743 | return min_t(u32, tcp_jiffies32 - icsk->icsk_ack.lrcvtime, |
1744 | tcp_jiffies32 - tp->rcv_tstamp); |
1745 | } |
1746 | |
1747 | static inline int tcp_fin_time(const struct sock *sk) |
1748 | { |
1749 | int fin_timeout = tcp_sk(sk)->linger2 ? : |
1750 | READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fin_timeout); |
1751 | const int rto = inet_csk(sk)->icsk_rto; |
1752 | |
1753 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
1754 | fin_timeout = (rto << 2) - (rto >> 1); |
1755 | |
1756 | return fin_timeout; |
1757 | } |
1758 | |
1759 | static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, |
1760 | int paws_win) |
1761 | { |
1762 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
1763 | return true; |
1764 | if (unlikely(!time_before32(ktime_get_seconds(), |
1765 | rx_opt->ts_recent_stamp + TCP_PAWS_WRAP))) |
1766 | return true; |
1767 | /* |
1768 | * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, |
1769 | * then following tcp messages have valid values. Ignore 0 value, |
1770 | * or else 'negative' tsval might forbid us to accept their packets. |
1771 | */ |
1772 | if (!rx_opt->ts_recent) |
1773 | return true; |
1774 | return false; |
1775 | } |
1776 | |
1777 | static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, |
1778 | int rst) |
1779 | { |
1780 | if (tcp_paws_check(rx_opt, paws_win: 0)) |
1781 | return false; |
1782 | |
1783 | /* RST segments are not recommended to carry timestamp, |
1784 | and, if they do, it is recommended to ignore PAWS because |
1785 | "their cleanup function should take precedence over timestamps." |
1786 | Certainly, it is mistake. It is necessary to understand the reasons |
1787 | of this constraint to relax it: if peer reboots, clock may go |
1788 | out-of-sync and half-open connections will not be reset. |
1789 | Actually, the problem would be not existing if all |
1790 | the implementations followed draft about maintaining clock |
1791 | via reboots. Linux-2.2 DOES NOT! |
1792 | |
1793 | However, we can relax time bounds for RST segments to MSL. |
1794 | */ |
1795 | if (rst && !time_before32(ktime_get_seconds(), |
1796 | rx_opt->ts_recent_stamp + TCP_PAWS_MSL)) |
1797 | return false; |
1798 | return true; |
1799 | } |
1800 | |
1801 | bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, |
1802 | int mib_idx, u32 *last_oow_ack_time); |
1803 | |
1804 | static inline void tcp_mib_init(struct net *net) |
1805 | { |
1806 | /* See RFC 2012 */ |
1807 | TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); |
1808 | TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); |
1809 | TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); |
1810 | TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); |
1811 | } |
1812 | |
1813 | /* from STCP */ |
1814 | static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) |
1815 | { |
1816 | tp->lost_skb_hint = NULL; |
1817 | } |
1818 | |
1819 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) |
1820 | { |
1821 | tcp_clear_retrans_hints_partial(tp); |
1822 | tp->retransmit_skb_hint = NULL; |
1823 | } |
1824 | |
1825 | #define tcp_md5_addr tcp_ao_addr |
1826 | |
1827 | /* - key database */ |
1828 | struct tcp_md5sig_key { |
1829 | struct hlist_node node; |
1830 | u8 keylen; |
1831 | u8 family; /* AF_INET or AF_INET6 */ |
1832 | u8 prefixlen; |
1833 | u8 flags; |
1834 | union tcp_md5_addr addr; |
1835 | int l3index; /* set if key added with L3 scope */ |
1836 | u8 key[TCP_MD5SIG_MAXKEYLEN]; |
1837 | struct rcu_head rcu; |
1838 | }; |
1839 | |
1840 | /* - sock block */ |
1841 | struct tcp_md5sig_info { |
1842 | struct hlist_head head; |
1843 | struct rcu_head rcu; |
1844 | }; |
1845 | |
1846 | /* - pseudo header */ |
1847 | struct tcp4_pseudohdr { |
1848 | __be32 saddr; |
1849 | __be32 daddr; |
1850 | __u8 pad; |
1851 | __u8 protocol; |
1852 | __be16 len; |
1853 | }; |
1854 | |
1855 | struct tcp6_pseudohdr { |
1856 | struct in6_addr saddr; |
1857 | struct in6_addr daddr; |
1858 | __be32 len; |
1859 | __be32 protocol; /* including padding */ |
1860 | }; |
1861 | |
1862 | union tcp_md5sum_block { |
1863 | struct tcp4_pseudohdr ip4; |
1864 | #if IS_ENABLED(CONFIG_IPV6) |
1865 | struct tcp6_pseudohdr ip6; |
1866 | #endif |
1867 | }; |
1868 | |
1869 | /* |
1870 | * struct tcp_sigpool - per-CPU pool of ahash_requests |
1871 | * @scratch: per-CPU temporary area, that can be used between |
1872 | * tcp_sigpool_start() and tcp_sigpool_end() to perform |
1873 | * crypto request |
1874 | * @req: pre-allocated ahash request |
1875 | */ |
1876 | struct tcp_sigpool { |
1877 | void *scratch; |
1878 | struct ahash_request *req; |
1879 | }; |
1880 | |
1881 | int tcp_sigpool_alloc_ahash(const char *alg, size_t scratch_size); |
1882 | void tcp_sigpool_get(unsigned int id); |
1883 | void tcp_sigpool_release(unsigned int id); |
1884 | int tcp_sigpool_hash_skb_data(struct tcp_sigpool *hp, |
1885 | const struct sk_buff *skb, |
1886 | unsigned int header_len); |
1887 | |
1888 | /** |
1889 | * tcp_sigpool_start - disable bh and start using tcp_sigpool_ahash |
1890 | * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash() |
1891 | * @c: returned tcp_sigpool for usage (uninitialized on failure) |
1892 | * |
1893 | * Returns: 0 on success, error otherwise. |
1894 | */ |
1895 | int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c); |
1896 | /** |
1897 | * tcp_sigpool_end - enable bh and stop using tcp_sigpool |
1898 | * @c: tcp_sigpool context that was returned by tcp_sigpool_start() |
1899 | */ |
1900 | void tcp_sigpool_end(struct tcp_sigpool *c); |
1901 | size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len); |
1902 | /* - functions */ |
1903 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
1904 | const struct sock *sk, const struct sk_buff *skb); |
1905 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
1906 | int family, u8 prefixlen, int l3index, u8 flags, |
1907 | const u8 *newkey, u8 newkeylen); |
1908 | int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr, |
1909 | int family, u8 prefixlen, int l3index, |
1910 | struct tcp_md5sig_key *key); |
1911 | |
1912 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, |
1913 | int family, u8 prefixlen, int l3index, u8 flags); |
1914 | void tcp_clear_md5_list(struct sock *sk); |
1915 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
1916 | const struct sock *addr_sk); |
1917 | |
1918 | #ifdef CONFIG_TCP_MD5SIG |
1919 | struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, |
1920 | const union tcp_md5_addr *addr, |
1921 | int family, bool any_l3index); |
1922 | static inline struct tcp_md5sig_key * |
1923 | tcp_md5_do_lookup(const struct sock *sk, int l3index, |
1924 | const union tcp_md5_addr *addr, int family) |
1925 | { |
1926 | if (!static_branch_unlikely(&tcp_md5_needed.key)) |
1927 | return NULL; |
1928 | return __tcp_md5_do_lookup(sk, l3index, addr, family, any_l3index: false); |
1929 | } |
1930 | |
1931 | static inline struct tcp_md5sig_key * |
1932 | tcp_md5_do_lookup_any_l3index(const struct sock *sk, |
1933 | const union tcp_md5_addr *addr, int family) |
1934 | { |
1935 | if (!static_branch_unlikely(&tcp_md5_needed.key)) |
1936 | return NULL; |
1937 | return __tcp_md5_do_lookup(sk, l3index: 0, addr, family, any_l3index: true); |
1938 | } |
1939 | |
1940 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) |
1941 | #else |
1942 | static inline struct tcp_md5sig_key * |
1943 | tcp_md5_do_lookup(const struct sock *sk, int l3index, |
1944 | const union tcp_md5_addr *addr, int family) |
1945 | { |
1946 | return NULL; |
1947 | } |
1948 | |
1949 | static inline struct tcp_md5sig_key * |
1950 | tcp_md5_do_lookup_any_l3index(const struct sock *sk, |
1951 | const union tcp_md5_addr *addr, int family) |
1952 | { |
1953 | return NULL; |
1954 | } |
1955 | |
1956 | #define tcp_twsk_md5_key(twsk) NULL |
1957 | #endif |
1958 | |
1959 | int tcp_md5_alloc_sigpool(void); |
1960 | void tcp_md5_release_sigpool(void); |
1961 | void tcp_md5_add_sigpool(void); |
1962 | extern int tcp_md5_sigpool_id; |
1963 | |
1964 | int tcp_md5_hash_key(struct tcp_sigpool *hp, |
1965 | const struct tcp_md5sig_key *key); |
1966 | |
1967 | /* From tcp_fastopen.c */ |
1968 | void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
1969 | struct tcp_fastopen_cookie *cookie); |
1970 | void tcp_fastopen_cache_set(struct sock *sk, u16 mss, |
1971 | struct tcp_fastopen_cookie *cookie, bool syn_lost, |
1972 | u16 try_exp); |
1973 | struct tcp_fastopen_request { |
1974 | /* Fast Open cookie. Size 0 means a cookie request */ |
1975 | struct tcp_fastopen_cookie cookie; |
1976 | struct msghdr *data; /* data in MSG_FASTOPEN */ |
1977 | size_t size; |
1978 | int copied; /* queued in tcp_connect() */ |
1979 | struct ubuf_info *uarg; |
1980 | }; |
1981 | void tcp_free_fastopen_req(struct tcp_sock *tp); |
1982 | void tcp_fastopen_destroy_cipher(struct sock *sk); |
1983 | void tcp_fastopen_ctx_destroy(struct net *net); |
1984 | int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, |
1985 | void *primary_key, void *backup_key); |
1986 | int tcp_fastopen_get_cipher(struct net *net, struct inet_connection_sock *icsk, |
1987 | u64 *key); |
1988 | void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); |
1989 | struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, |
1990 | struct request_sock *req, |
1991 | struct tcp_fastopen_cookie *foc, |
1992 | const struct dst_entry *dst); |
1993 | void tcp_fastopen_init_key_once(struct net *net); |
1994 | bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, |
1995 | struct tcp_fastopen_cookie *cookie); |
1996 | bool tcp_fastopen_defer_connect(struct sock *sk, int *err); |
1997 | #define TCP_FASTOPEN_KEY_LENGTH sizeof(siphash_key_t) |
1998 | #define TCP_FASTOPEN_KEY_MAX 2 |
1999 | #define TCP_FASTOPEN_KEY_BUF_LENGTH \ |
2000 | (TCP_FASTOPEN_KEY_LENGTH * TCP_FASTOPEN_KEY_MAX) |
2001 | |
2002 | /* Fastopen key context */ |
2003 | struct tcp_fastopen_context { |
2004 | siphash_key_t key[TCP_FASTOPEN_KEY_MAX]; |
2005 | int num; |
2006 | struct rcu_head rcu; |
2007 | }; |
2008 | |
2009 | void tcp_fastopen_active_disable(struct sock *sk); |
2010 | bool tcp_fastopen_active_should_disable(struct sock *sk); |
2011 | void tcp_fastopen_active_disable_ofo_check(struct sock *sk); |
2012 | void tcp_fastopen_active_detect_blackhole(struct sock *sk, bool expired); |
2013 | |
2014 | /* Caller needs to wrap with rcu_read_(un)lock() */ |
2015 | static inline |
2016 | struct tcp_fastopen_context *tcp_fastopen_get_ctx(const struct sock *sk) |
2017 | { |
2018 | struct tcp_fastopen_context *ctx; |
2019 | |
2020 | ctx = rcu_dereference(inet_csk(sk)->icsk_accept_queue.fastopenq.ctx); |
2021 | if (!ctx) |
2022 | ctx = rcu_dereference(sock_net(sk)->ipv4.tcp_fastopen_ctx); |
2023 | return ctx; |
2024 | } |
2025 | |
2026 | static inline |
2027 | bool tcp_fastopen_cookie_match(const struct tcp_fastopen_cookie *foc, |
2028 | const struct tcp_fastopen_cookie *orig) |
2029 | { |
2030 | if (orig->len == TCP_FASTOPEN_COOKIE_SIZE && |
2031 | orig->len == foc->len && |
2032 | !memcmp(p: orig->val, q: foc->val, size: foc->len)) |
2033 | return true; |
2034 | return false; |
2035 | } |
2036 | |
2037 | static inline |
2038 | int tcp_fastopen_context_len(const struct tcp_fastopen_context *ctx) |
2039 | { |
2040 | return ctx->num; |
2041 | } |
2042 | |
2043 | /* Latencies incurred by various limits for a sender. They are |
2044 | * chronograph-like stats that are mutually exclusive. |
2045 | */ |
2046 | enum tcp_chrono { |
2047 | TCP_CHRONO_UNSPEC, |
2048 | TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ |
2049 | TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ |
2050 | TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ |
2051 | __TCP_CHRONO_MAX, |
2052 | }; |
2053 | |
2054 | void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); |
2055 | void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); |
2056 | |
2057 | /* This helper is needed, because skb->tcp_tsorted_anchor uses |
2058 | * the same memory storage than skb->destructor/_skb_refdst |
2059 | */ |
2060 | static inline void tcp_skb_tsorted_anchor_cleanup(struct sk_buff *skb) |
2061 | { |
2062 | skb->destructor = NULL; |
2063 | skb->_skb_refdst = 0UL; |
2064 | } |
2065 | |
2066 | #define tcp_skb_tsorted_save(skb) { \ |
2067 | unsigned long _save = skb->_skb_refdst; \ |
2068 | skb->_skb_refdst = 0UL; |
2069 | |
2070 | #define tcp_skb_tsorted_restore(skb) \ |
2071 | skb->_skb_refdst = _save; \ |
2072 | } |
2073 | |
2074 | void tcp_write_queue_purge(struct sock *sk); |
2075 | |
2076 | static inline struct sk_buff *tcp_rtx_queue_head(const struct sock *sk) |
2077 | { |
2078 | return skb_rb_first(&sk->tcp_rtx_queue); |
2079 | } |
2080 | |
2081 | static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) |
2082 | { |
2083 | return skb_rb_last(&sk->tcp_rtx_queue); |
2084 | } |
2085 | |
2086 | static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) |
2087 | { |
2088 | return skb_peek_tail(list_: &sk->sk_write_queue); |
2089 | } |
2090 | |
2091 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
2092 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
2093 | |
2094 | static inline struct sk_buff *tcp_send_head(const struct sock *sk) |
2095 | { |
2096 | return skb_peek(list_: &sk->sk_write_queue); |
2097 | } |
2098 | |
2099 | static inline bool tcp_skb_is_last(const struct sock *sk, |
2100 | const struct sk_buff *skb) |
2101 | { |
2102 | return skb_queue_is_last(list: &sk->sk_write_queue, skb); |
2103 | } |
2104 | |
2105 | /** |
2106 | * tcp_write_queue_empty - test if any payload (or FIN) is available in write queue |
2107 | * @sk: socket |
2108 | * |
2109 | * Since the write queue can have a temporary empty skb in it, |
2110 | * we must not use "return skb_queue_empty(&sk->sk_write_queue)" |
2111 | */ |
2112 | static inline bool tcp_write_queue_empty(const struct sock *sk) |
2113 | { |
2114 | const struct tcp_sock *tp = tcp_sk(sk); |
2115 | |
2116 | return tp->write_seq == tp->snd_nxt; |
2117 | } |
2118 | |
2119 | static inline bool tcp_rtx_queue_empty(const struct sock *sk) |
2120 | { |
2121 | return RB_EMPTY_ROOT(&sk->tcp_rtx_queue); |
2122 | } |
2123 | |
2124 | static inline bool tcp_rtx_and_write_queues_empty(const struct sock *sk) |
2125 | { |
2126 | return tcp_rtx_queue_empty(sk) && tcp_write_queue_empty(sk); |
2127 | } |
2128 | |
2129 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) |
2130 | { |
2131 | __skb_queue_tail(list: &sk->sk_write_queue, newsk: skb); |
2132 | |
2133 | /* Queue it, remembering where we must start sending. */ |
2134 | if (sk->sk_write_queue.next == skb) |
2135 | tcp_chrono_start(sk, type: TCP_CHRONO_BUSY); |
2136 | } |
2137 | |
2138 | /* Insert new before skb on the write queue of sk. */ |
2139 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
2140 | struct sk_buff *skb, |
2141 | struct sock *sk) |
2142 | { |
2143 | __skb_queue_before(list: &sk->sk_write_queue, next: skb, newsk: new); |
2144 | } |
2145 | |
2146 | static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) |
2147 | { |
2148 | tcp_skb_tsorted_anchor_cleanup(skb); |
2149 | __skb_unlink(skb, list: &sk->sk_write_queue); |
2150 | } |
2151 | |
2152 | void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb); |
2153 | |
2154 | static inline void tcp_rtx_queue_unlink(struct sk_buff *skb, struct sock *sk) |
2155 | { |
2156 | tcp_skb_tsorted_anchor_cleanup(skb); |
2157 | rb_erase(&skb->rbnode, &sk->tcp_rtx_queue); |
2158 | } |
2159 | |
2160 | static inline void tcp_rtx_queue_unlink_and_free(struct sk_buff *skb, struct sock *sk) |
2161 | { |
2162 | list_del(entry: &skb->tcp_tsorted_anchor); |
2163 | tcp_rtx_queue_unlink(skb, sk); |
2164 | tcp_wmem_free_skb(sk, skb); |
2165 | } |
2166 | |
2167 | static inline void tcp_write_collapse_fence(struct sock *sk) |
2168 | { |
2169 | struct sk_buff *skb = tcp_write_queue_tail(sk); |
2170 | |
2171 | if (skb) |
2172 | TCP_SKB_CB(skb)->eor = 1; |
2173 | } |
2174 | |
2175 | static inline void tcp_push_pending_frames(struct sock *sk) |
2176 | { |
2177 | if (tcp_send_head(sk)) { |
2178 | struct tcp_sock *tp = tcp_sk(sk); |
2179 | |
2180 | __tcp_push_pending_frames(sk, cur_mss: tcp_current_mss(sk), nonagle: tp->nonagle); |
2181 | } |
2182 | } |
2183 | |
2184 | /* Start sequence of the skb just after the highest skb with SACKed |
2185 | * bit, valid only if sacked_out > 0 or when the caller has ensured |
2186 | * validity by itself. |
2187 | */ |
2188 | static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) |
2189 | { |
2190 | if (!tp->sacked_out) |
2191 | return tp->snd_una; |
2192 | |
2193 | if (tp->highest_sack == NULL) |
2194 | return tp->snd_nxt; |
2195 | |
2196 | return TCP_SKB_CB(tp->highest_sack)->seq; |
2197 | } |
2198 | |
2199 | static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) |
2200 | { |
2201 | tcp_sk(sk)->highest_sack = skb_rb_next(skb); |
2202 | } |
2203 | |
2204 | static inline struct sk_buff *tcp_highest_sack(struct sock *sk) |
2205 | { |
2206 | return tcp_sk(sk)->highest_sack; |
2207 | } |
2208 | |
2209 | static inline void tcp_highest_sack_reset(struct sock *sk) |
2210 | { |
2211 | tcp_sk(sk)->highest_sack = tcp_rtx_queue_head(sk); |
2212 | } |
2213 | |
2214 | /* Called when old skb is about to be deleted and replaced by new skb */ |
2215 | static inline void tcp_highest_sack_replace(struct sock *sk, |
2216 | struct sk_buff *old, |
2217 | struct sk_buff *new) |
2218 | { |
2219 | if (old == tcp_highest_sack(sk)) |
2220 | tcp_sk(sk)->highest_sack = new; |
2221 | } |
2222 | |
2223 | /* This helper checks if socket has IP_TRANSPARENT set */ |
2224 | static inline bool inet_sk_transparent(const struct sock *sk) |
2225 | { |
2226 | switch (sk->sk_state) { |
2227 | case TCP_TIME_WAIT: |
2228 | return inet_twsk(sk)->tw_transparent; |
2229 | case TCP_NEW_SYN_RECV: |
2230 | return inet_rsk(sk: inet_reqsk(sk))->no_srccheck; |
2231 | } |
2232 | return inet_test_bit(TRANSPARENT, sk); |
2233 | } |
2234 | |
2235 | /* Determines whether this is a thin stream (which may suffer from |
2236 | * increased latency). Used to trigger latency-reducing mechanisms. |
2237 | */ |
2238 | static inline bool tcp_stream_is_thin(struct tcp_sock *tp) |
2239 | { |
2240 | return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); |
2241 | } |
2242 | |
2243 | /* /proc */ |
2244 | enum tcp_seq_states { |
2245 | TCP_SEQ_STATE_LISTENING, |
2246 | TCP_SEQ_STATE_ESTABLISHED, |
2247 | }; |
2248 | |
2249 | void *tcp_seq_start(struct seq_file *seq, loff_t *pos); |
2250 | void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos); |
2251 | void tcp_seq_stop(struct seq_file *seq, void *v); |
2252 | |
2253 | struct tcp_seq_afinfo { |
2254 | sa_family_t family; |
2255 | }; |
2256 | |
2257 | struct tcp_iter_state { |
2258 | struct seq_net_private p; |
2259 | enum tcp_seq_states state; |
2260 | struct sock *syn_wait_sk; |
2261 | int bucket, offset, sbucket, num; |
2262 | loff_t last_pos; |
2263 | }; |
2264 | |
2265 | extern struct request_sock_ops tcp_request_sock_ops; |
2266 | extern struct request_sock_ops tcp6_request_sock_ops; |
2267 | |
2268 | void tcp_v4_destroy_sock(struct sock *sk); |
2269 | |
2270 | struct sk_buff *tcp_gso_segment(struct sk_buff *skb, |
2271 | netdev_features_t features); |
2272 | struct tcphdr *tcp_gro_pull_header(struct sk_buff *skb); |
2273 | struct sk_buff *tcp_gro_lookup(struct list_head *head, struct tcphdr *th); |
2274 | struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb, |
2275 | struct tcphdr *th); |
2276 | INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *skb, int thoff)); |
2277 | INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)); |
2278 | INDIRECT_CALLABLE_DECLARE(int tcp6_gro_complete(struct sk_buff *skb, int thoff)); |
2279 | INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)); |
2280 | #ifdef CONFIG_INET |
2281 | void tcp_gro_complete(struct sk_buff *skb); |
2282 | #else |
2283 | static inline void tcp_gro_complete(struct sk_buff *skb) { } |
2284 | #endif |
2285 | |
2286 | void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); |
2287 | |
2288 | static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) |
2289 | { |
2290 | struct net *net = sock_net(sk: (struct sock *)tp); |
2291 | u32 val; |
2292 | |
2293 | val = READ_ONCE(tp->notsent_lowat); |
2294 | |
2295 | return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); |
2296 | } |
2297 | |
2298 | bool tcp_stream_memory_free(const struct sock *sk, int wake); |
2299 | |
2300 | #ifdef CONFIG_PROC_FS |
2301 | int tcp4_proc_init(void); |
2302 | void tcp4_proc_exit(void); |
2303 | #endif |
2304 | |
2305 | int tcp_rtx_synack(const struct sock *sk, struct request_sock *req); |
2306 | int tcp_conn_request(struct request_sock_ops *rsk_ops, |
2307 | const struct tcp_request_sock_ops *af_ops, |
2308 | struct sock *sk, struct sk_buff *skb); |
2309 | |
2310 | /* TCP af-specific functions */ |
2311 | struct tcp_sock_af_ops { |
2312 | #ifdef CONFIG_TCP_MD5SIG |
2313 | struct tcp_md5sig_key *(*md5_lookup) (const struct sock *sk, |
2314 | const struct sock *addr_sk); |
2315 | int (*calc_md5_hash)(char *location, |
2316 | const struct tcp_md5sig_key *md5, |
2317 | const struct sock *sk, |
2318 | const struct sk_buff *skb); |
2319 | int (*md5_parse)(struct sock *sk, |
2320 | int optname, |
2321 | sockptr_t optval, |
2322 | int optlen); |
2323 | #endif |
2324 | #ifdef CONFIG_TCP_AO |
2325 | int (*ao_parse)(struct sock *sk, int optname, sockptr_t optval, int optlen); |
2326 | struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, |
2327 | struct sock *addr_sk, |
2328 | int sndid, int rcvid); |
2329 | int (*ao_calc_key_sk)(struct tcp_ao_key *mkt, u8 *key, |
2330 | const struct sock *sk, |
2331 | __be32 sisn, __be32 disn, bool send); |
2332 | int (*calc_ao_hash)(char *location, struct tcp_ao_key *ao, |
2333 | const struct sock *sk, const struct sk_buff *skb, |
2334 | const u8 *tkey, int hash_offset, u32 sne); |
2335 | #endif |
2336 | }; |
2337 | |
2338 | struct tcp_request_sock_ops { |
2339 | u16 mss_clamp; |
2340 | #ifdef CONFIG_TCP_MD5SIG |
2341 | struct tcp_md5sig_key *(*req_md5_lookup)(const struct sock *sk, |
2342 | const struct sock *addr_sk); |
2343 | int (*calc_md5_hash) (char *location, |
2344 | const struct tcp_md5sig_key *md5, |
2345 | const struct sock *sk, |
2346 | const struct sk_buff *skb); |
2347 | #endif |
2348 | #ifdef CONFIG_TCP_AO |
2349 | struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, |
2350 | struct request_sock *req, |
2351 | int sndid, int rcvid); |
2352 | int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk); |
2353 | int (*ao_synack_hash)(char *ao_hash, struct tcp_ao_key *mkt, |
2354 | struct request_sock *req, const struct sk_buff *skb, |
2355 | int hash_offset, u32 sne); |
2356 | #endif |
2357 | #ifdef CONFIG_SYN_COOKIES |
2358 | __u32 (*cookie_init_seq)(const struct sk_buff *skb, |
2359 | __u16 *mss); |
2360 | #endif |
2361 | struct dst_entry *(*route_req)(const struct sock *sk, |
2362 | struct sk_buff *skb, |
2363 | struct flowi *fl, |
2364 | struct request_sock *req, |
2365 | u32 tw_isn); |
2366 | u32 (*init_seq)(const struct sk_buff *skb); |
2367 | u32 (*init_ts_off)(const struct net *net, const struct sk_buff *skb); |
2368 | int (*send_synack)(const struct sock *sk, struct dst_entry *dst, |
2369 | struct flowi *fl, struct request_sock *req, |
2370 | struct tcp_fastopen_cookie *foc, |
2371 | enum tcp_synack_type synack_type, |
2372 | struct sk_buff *syn_skb); |
2373 | }; |
2374 | |
2375 | extern const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops; |
2376 | #if IS_ENABLED(CONFIG_IPV6) |
2377 | extern const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops; |
2378 | #endif |
2379 | |
2380 | #ifdef CONFIG_SYN_COOKIES |
2381 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, |
2382 | const struct sock *sk, struct sk_buff *skb, |
2383 | __u16 *mss) |
2384 | { |
2385 | tcp_synq_overflow(sk); |
2386 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); |
2387 | return ops->cookie_init_seq(skb, mss); |
2388 | } |
2389 | #else |
2390 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, |
2391 | const struct sock *sk, struct sk_buff *skb, |
2392 | __u16 *mss) |
2393 | { |
2394 | return 0; |
2395 | } |
2396 | #endif |
2397 | |
2398 | struct tcp_key { |
2399 | union { |
2400 | struct { |
2401 | struct tcp_ao_key *ao_key; |
2402 | char *traffic_key; |
2403 | u32 sne; |
2404 | u8 rcv_next; |
2405 | }; |
2406 | struct tcp_md5sig_key *md5_key; |
2407 | }; |
2408 | enum { |
2409 | TCP_KEY_NONE = 0, |
2410 | TCP_KEY_MD5, |
2411 | TCP_KEY_AO, |
2412 | } type; |
2413 | }; |
2414 | |
2415 | static inline void tcp_get_current_key(const struct sock *sk, |
2416 | struct tcp_key *out) |
2417 | { |
2418 | #if defined(CONFIG_TCP_AO) || defined(CONFIG_TCP_MD5SIG) |
2419 | const struct tcp_sock *tp = tcp_sk(sk); |
2420 | #endif |
2421 | |
2422 | #ifdef CONFIG_TCP_AO |
2423 | if (static_branch_unlikely(&tcp_ao_needed.key)) { |
2424 | struct tcp_ao_info *ao; |
2425 | |
2426 | ao = rcu_dereference_protected(tp->ao_info, |
2427 | lockdep_sock_is_held(sk)); |
2428 | if (ao) { |
2429 | out->ao_key = READ_ONCE(ao->current_key); |
2430 | out->type = TCP_KEY_AO; |
2431 | return; |
2432 | } |
2433 | } |
2434 | #endif |
2435 | #ifdef CONFIG_TCP_MD5SIG |
2436 | if (static_branch_unlikely(&tcp_md5_needed.key) && |
2437 | rcu_access_pointer(tp->md5sig_info)) { |
2438 | out->md5_key = tp->af_specific->md5_lookup(sk, sk); |
2439 | if (out->md5_key) { |
2440 | out->type = TCP_KEY_MD5; |
2441 | return; |
2442 | } |
2443 | } |
2444 | #endif |
2445 | out->type = TCP_KEY_NONE; |
2446 | } |
2447 | |
2448 | static inline bool tcp_key_is_md5(const struct tcp_key *key) |
2449 | { |
2450 | if (static_branch_tcp_md5()) |
2451 | return key->type == TCP_KEY_MD5; |
2452 | return false; |
2453 | } |
2454 | |
2455 | static inline bool tcp_key_is_ao(const struct tcp_key *key) |
2456 | { |
2457 | if (static_branch_tcp_ao()) |
2458 | return key->type == TCP_KEY_AO; |
2459 | return false; |
2460 | } |
2461 | |
2462 | int tcpv4_offload_init(void); |
2463 | |
2464 | void tcp_v4_init(void); |
2465 | void tcp_init(void); |
2466 | |
2467 | /* tcp_recovery.c */ |
2468 | void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb); |
2469 | void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced); |
2470 | extern s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, |
2471 | u32 reo_wnd); |
2472 | extern bool tcp_rack_mark_lost(struct sock *sk); |
2473 | extern void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, |
2474 | u64 xmit_time); |
2475 | extern void tcp_rack_reo_timeout(struct sock *sk); |
2476 | extern void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs); |
2477 | |
2478 | /* tcp_plb.c */ |
2479 | |
2480 | /* |
2481 | * Scaling factor for fractions in PLB. For example, tcp_plb_update_state |
2482 | * expects cong_ratio which represents fraction of traffic that experienced |
2483 | * congestion over a single RTT. In order to avoid floating point operations, |
2484 | * this fraction should be mapped to (1 << TCP_PLB_SCALE) and passed in. |
2485 | */ |
2486 | #define TCP_PLB_SCALE 8 |
2487 | |
2488 | /* State for PLB (Protective Load Balancing) for a single TCP connection. */ |
2489 | struct tcp_plb_state { |
2490 | u8 consec_cong_rounds:5, /* consecutive congested rounds */ |
2491 | unused:3; |
2492 | u32 pause_until; /* jiffies32 when PLB can resume rerouting */ |
2493 | }; |
2494 | |
2495 | static inline void tcp_plb_init(const struct sock *sk, |
2496 | struct tcp_plb_state *plb) |
2497 | { |
2498 | plb->consec_cong_rounds = 0; |
2499 | plb->pause_until = 0; |
2500 | } |
2501 | void tcp_plb_update_state(const struct sock *sk, struct tcp_plb_state *plb, |
2502 | const int cong_ratio); |
2503 | void tcp_plb_check_rehash(struct sock *sk, struct tcp_plb_state *plb); |
2504 | void tcp_plb_update_state_upon_rto(struct sock *sk, struct tcp_plb_state *plb); |
2505 | |
2506 | static inline void tcp_warn_once(const struct sock *sk, bool cond, const char *str) |
2507 | { |
2508 | WARN_ONCE(cond, |
2509 | "%scwn:%u out:%u sacked:%u lost:%u retrans:%u tlp_high_seq:%u sk_state:%u ca_state:%u advmss:%u mss_cache:%u pmtu:%u\n", |
2510 | str, |
2511 | tcp_snd_cwnd(tcp_sk(sk)), |
2512 | tcp_sk(sk)->packets_out, tcp_sk(sk)->sacked_out, |
2513 | tcp_sk(sk)->lost_out, tcp_sk(sk)->retrans_out, |
2514 | tcp_sk(sk)->tlp_high_seq, sk->sk_state, |
2515 | inet_csk(sk)->icsk_ca_state, |
2516 | tcp_sk(sk)->advmss, tcp_sk(sk)->mss_cache, |
2517 | inet_csk(sk)->icsk_pmtu_cookie); |
2518 | } |
2519 | |
2520 | /* At how many usecs into the future should the RTO fire? */ |
2521 | static inline s64 tcp_rto_delta_us(const struct sock *sk) |
2522 | { |
2523 | const struct sk_buff *skb = tcp_rtx_queue_head(sk); |
2524 | u32 rto = inet_csk(sk)->icsk_rto; |
2525 | |
2526 | if (likely(skb)) { |
2527 | u64 rto_time_stamp_us = tcp_skb_timestamp_us(skb) + jiffies_to_usecs(j: rto); |
2528 | |
2529 | return rto_time_stamp_us - tcp_sk(sk)->tcp_mstamp; |
2530 | } else { |
2531 | tcp_warn_once(sk, cond: 1, str: "rtx queue empty: "); |
2532 | return jiffies_to_usecs(j: rto); |
2533 | } |
2534 | |
2535 | } |
2536 | |
2537 | /* |
2538 | * Save and compile IPv4 options, return a pointer to it |
2539 | */ |
2540 | static inline struct ip_options_rcu *tcp_v4_save_options(struct net *net, |
2541 | struct sk_buff *skb) |
2542 | { |
2543 | const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; |
2544 | struct ip_options_rcu *dopt = NULL; |
2545 | |
2546 | if (opt->optlen) { |
2547 | int opt_size = sizeof(*dopt) + opt->optlen; |
2548 | |
2549 | dopt = kmalloc(opt_size, GFP_ATOMIC); |
2550 | if (dopt && __ip_options_echo(net, dopt: &dopt->opt, skb, sopt: opt)) { |
2551 | kfree(objp: dopt); |
2552 | dopt = NULL; |
2553 | } |
2554 | } |
2555 | return dopt; |
2556 | } |
2557 | |
2558 | /* locally generated TCP pure ACKs have skb->truesize == 2 |
2559 | * (check tcp_send_ack() in net/ipv4/tcp_output.c ) |
2560 | * This is much faster than dissecting the packet to find out. |
2561 | * (Think of GRE encapsulations, IPv4, IPv6, ...) |
2562 | */ |
2563 | static inline bool skb_is_tcp_pure_ack(const struct sk_buff *skb) |
2564 | { |
2565 | return skb->truesize == 2; |
2566 | } |
2567 | |
2568 | static inline void skb_set_tcp_pure_ack(struct sk_buff *skb) |
2569 | { |
2570 | skb->truesize = 2; |
2571 | } |
2572 | |
2573 | static inline int tcp_inq(struct sock *sk) |
2574 | { |
2575 | struct tcp_sock *tp = tcp_sk(sk); |
2576 | int answ; |
2577 | |
2578 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { |
2579 | answ = 0; |
2580 | } else if (sock_flag(sk, flag: SOCK_URGINLINE) || |
2581 | !tp->urg_data || |
2582 | before(seq1: tp->urg_seq, seq2: tp->copied_seq) || |
2583 | !before(seq1: tp->urg_seq, seq2: tp->rcv_nxt)) { |
2584 | |
2585 | answ = tp->rcv_nxt - tp->copied_seq; |
2586 | |
2587 | /* Subtract 1, if FIN was received */ |
2588 | if (answ && sock_flag(sk, flag: SOCK_DONE)) |
2589 | answ--; |
2590 | } else { |
2591 | answ = tp->urg_seq - tp->copied_seq; |
2592 | } |
2593 | |
2594 | return answ; |
2595 | } |
2596 | |
2597 | int tcp_peek_len(struct socket *sock); |
2598 | |
2599 | static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) |
2600 | { |
2601 | u16 segs_in; |
2602 | |
2603 | segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); |
2604 | |
2605 | /* We update these fields while other threads might |
2606 | * read them from tcp_get_info() |
2607 | */ |
2608 | WRITE_ONCE(tp->segs_in, tp->segs_in + segs_in); |
2609 | if (skb->len > tcp_hdrlen(skb)) |
2610 | WRITE_ONCE(tp->data_segs_in, tp->data_segs_in + segs_in); |
2611 | } |
2612 | |
2613 | /* |
2614 | * TCP listen path runs lockless. |
2615 | * We forced "struct sock" to be const qualified to make sure |
2616 | * we don't modify one of its field by mistake. |
2617 | * Here, we increment sk_drops which is an atomic_t, so we can safely |
2618 | * make sock writable again. |
2619 | */ |
2620 | static inline void tcp_listendrop(const struct sock *sk) |
2621 | { |
2622 | atomic_inc(v: &((struct sock *)sk)->sk_drops); |
2623 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); |
2624 | } |
2625 | |
2626 | enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer); |
2627 | |
2628 | /* |
2629 | * Interface for adding Upper Level Protocols over TCP |
2630 | */ |
2631 | |
2632 | #define TCP_ULP_NAME_MAX 16 |
2633 | #define TCP_ULP_MAX 128 |
2634 | #define TCP_ULP_BUF_MAX (TCP_ULP_NAME_MAX*TCP_ULP_MAX) |
2635 | |
2636 | struct tcp_ulp_ops { |
2637 | struct list_head list; |
2638 | |
2639 | /* initialize ulp */ |
2640 | int (*init)(struct sock *sk); |
2641 | /* update ulp */ |
2642 | void (*update)(struct sock *sk, struct proto *p, |
2643 | void (*write_space)(struct sock *sk)); |
2644 | /* cleanup ulp */ |
2645 | void (*release)(struct sock *sk); |
2646 | /* diagnostic */ |
2647 | int (*get_info)(struct sock *sk, struct sk_buff *skb, bool net_admin); |
2648 | size_t (*get_info_size)(const struct sock *sk, bool net_admin); |
2649 | /* clone ulp */ |
2650 | void (*clone)(const struct request_sock *req, struct sock *newsk, |
2651 | const gfp_t priority); |
2652 | |
2653 | char name[TCP_ULP_NAME_MAX]; |
2654 | struct module *owner; |
2655 | }; |
2656 | int tcp_register_ulp(struct tcp_ulp_ops *type); |
2657 | void tcp_unregister_ulp(struct tcp_ulp_ops *type); |
2658 | int tcp_set_ulp(struct sock *sk, const char *name); |
2659 | void tcp_get_available_ulp(char *buf, size_t len); |
2660 | void tcp_cleanup_ulp(struct sock *sk); |
2661 | void tcp_update_ulp(struct sock *sk, struct proto *p, |
2662 | void (*write_space)(struct sock *sk)); |
2663 | |
2664 | #define MODULE_ALIAS_TCP_ULP(name) \ |
2665 | __MODULE_INFO(alias, alias_userspace, name); \ |
2666 | __MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name) |
2667 | |
2668 | #ifdef CONFIG_NET_SOCK_MSG |
2669 | struct sk_msg; |
2670 | struct sk_psock; |
2671 | |
2672 | #ifdef CONFIG_BPF_SYSCALL |
2673 | int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore); |
2674 | void tcp_bpf_clone(const struct sock *sk, struct sock *newsk); |
2675 | #ifdef CONFIG_BPF_STREAM_PARSER |
2676 | struct strparser; |
2677 | int tcp_bpf_strp_read_sock(struct strparser *strp, read_descriptor_t *desc, |
2678 | sk_read_actor_t recv_actor); |
2679 | #endif /* CONFIG_BPF_STREAM_PARSER */ |
2680 | #endif /* CONFIG_BPF_SYSCALL */ |
2681 | |
2682 | #ifdef CONFIG_INET |
2683 | void tcp_eat_skb(struct sock *sk, struct sk_buff *skb); |
2684 | #else |
2685 | static inline void tcp_eat_skb(struct sock *sk, struct sk_buff *skb) |
2686 | { |
2687 | } |
2688 | #endif |
2689 | |
2690 | int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress, |
2691 | struct sk_msg *msg, u32 bytes, int flags); |
2692 | #endif /* CONFIG_NET_SOCK_MSG */ |
2693 | |
2694 | #if !defined(CONFIG_BPF_SYSCALL) || !defined(CONFIG_NET_SOCK_MSG) |
2695 | static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk) |
2696 | { |
2697 | } |
2698 | #endif |
2699 | |
2700 | #ifdef CONFIG_CGROUP_BPF |
2701 | static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, |
2702 | struct sk_buff *skb, |
2703 | unsigned int end_offset) |
2704 | { |
2705 | skops->skb = skb; |
2706 | skops->skb_data_end = skb->data + end_offset; |
2707 | } |
2708 | #else |
2709 | static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, |
2710 | struct sk_buff *skb, |
2711 | unsigned int end_offset) |
2712 | { |
2713 | } |
2714 | #endif |
2715 | |
2716 | /* Call BPF_SOCK_OPS program that returns an int. If the return value |
2717 | * is < 0, then the BPF op failed (for example if the loaded BPF |
2718 | * program does not support the chosen operation or there is no BPF |
2719 | * program loaded). |
2720 | */ |
2721 | #ifdef CONFIG_BPF |
2722 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
2723 | { |
2724 | struct bpf_sock_ops_kern sock_ops; |
2725 | int ret; |
2726 | |
2727 | memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); |
2728 | if (sk_fullsock(sk)) { |
2729 | sock_ops.is_fullsock = 1; |
2730 | sock_ops.is_locked_tcp_sock = 1; |
2731 | sock_owned_by_me(sk); |
2732 | } |
2733 | |
2734 | sock_ops.sk = sk; |
2735 | sock_ops.op = op; |
2736 | if (nargs > 0) |
2737 | memcpy(sock_ops.args, args, nargs * sizeof(*args)); |
2738 | |
2739 | ret = BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); |
2740 | if (ret == 0) |
2741 | ret = sock_ops.reply; |
2742 | else |
2743 | ret = -1; |
2744 | return ret; |
2745 | } |
2746 | |
2747 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) |
2748 | { |
2749 | u32 args[2] = {arg1, arg2}; |
2750 | |
2751 | return tcp_call_bpf(sk, op, nargs: 2, args); |
2752 | } |
2753 | |
2754 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, |
2755 | u32 arg3) |
2756 | { |
2757 | u32 args[3] = {arg1, arg2, arg3}; |
2758 | |
2759 | return tcp_call_bpf(sk, op, nargs: 3, args); |
2760 | } |
2761 | |
2762 | #else |
2763 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
2764 | { |
2765 | return -EPERM; |
2766 | } |
2767 | |
2768 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) |
2769 | { |
2770 | return -EPERM; |
2771 | } |
2772 | |
2773 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, |
2774 | u32 arg3) |
2775 | { |
2776 | return -EPERM; |
2777 | } |
2778 | |
2779 | #endif |
2780 | |
2781 | static inline u32 tcp_timeout_init(struct sock *sk) |
2782 | { |
2783 | int timeout; |
2784 | |
2785 | timeout = tcp_call_bpf(sk, op: BPF_SOCK_OPS_TIMEOUT_INIT, nargs: 0, NULL); |
2786 | |
2787 | if (timeout <= 0) |
2788 | timeout = TCP_TIMEOUT_INIT; |
2789 | return min_t(int, timeout, TCP_RTO_MAX); |
2790 | } |
2791 | |
2792 | static inline u32 tcp_rwnd_init_bpf(struct sock *sk) |
2793 | { |
2794 | int rwnd; |
2795 | |
2796 | rwnd = tcp_call_bpf(sk, op: BPF_SOCK_OPS_RWND_INIT, nargs: 0, NULL); |
2797 | |
2798 | if (rwnd < 0) |
2799 | rwnd = 0; |
2800 | return rwnd; |
2801 | } |
2802 | |
2803 | static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) |
2804 | { |
2805 | return (tcp_call_bpf(sk, op: BPF_SOCK_OPS_NEEDS_ECN, nargs: 0, NULL) == 1); |
2806 | } |
2807 | |
2808 | static inline void tcp_bpf_rtt(struct sock *sk, long mrtt, u32 srtt) |
2809 | { |
2810 | if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_RTT_CB_FLAG)) |
2811 | tcp_call_bpf_2arg(sk, op: BPF_SOCK_OPS_RTT_CB, arg1: mrtt, arg2: srtt); |
2812 | } |
2813 | |
2814 | #if IS_ENABLED(CONFIG_SMC) |
2815 | extern struct static_key_false tcp_have_smc; |
2816 | #endif |
2817 | |
2818 | #if IS_ENABLED(CONFIG_TLS_DEVICE) |
2819 | void clean_acked_data_enable(struct tcp_sock *tp, |
2820 | void (*cad)(struct sock *sk, u32 ack_seq)); |
2821 | void clean_acked_data_disable(struct tcp_sock *tp); |
2822 | void clean_acked_data_flush(void); |
2823 | #endif |
2824 | |
2825 | DECLARE_STATIC_KEY_FALSE(tcp_tx_delay_enabled); |
2826 | static inline void tcp_add_tx_delay(struct sk_buff *skb, |
2827 | const struct tcp_sock *tp) |
2828 | { |
2829 | if (static_branch_unlikely(&tcp_tx_delay_enabled)) |
2830 | skb->skb_mstamp_ns += (u64)tp->tcp_tx_delay * NSEC_PER_USEC; |
2831 | } |
2832 | |
2833 | /* Compute Earliest Departure Time for some control packets |
2834 | * like ACK or RST for TIME_WAIT or non ESTABLISHED sockets. |
2835 | */ |
2836 | static inline u64 tcp_transmit_time(const struct sock *sk) |
2837 | { |
2838 | if (static_branch_unlikely(&tcp_tx_delay_enabled)) { |
2839 | u32 delay = (sk->sk_state == TCP_TIME_WAIT) ? |
2840 | tcp_twsk(sk)->tw_tx_delay : tcp_sk(sk)->tcp_tx_delay; |
2841 | |
2842 | return tcp_clock_ns() + (u64)delay * NSEC_PER_USEC; |
2843 | } |
2844 | return 0; |
2845 | } |
2846 | |
2847 | static inline int tcp_parse_auth_options(const struct tcphdr *th, |
2848 | const u8 **md5_hash, const struct tcp_ao_hdr **aoh) |
2849 | { |
2850 | const u8 *md5_tmp, *ao_tmp; |
2851 | int ret; |
2852 | |
2853 | ret = tcp_do_parse_auth_options(th, md5_hash: &md5_tmp, ao_hash: &ao_tmp); |
2854 | if (ret) |
2855 | return ret; |
2856 | |
2857 | if (md5_hash) |
2858 | *md5_hash = md5_tmp; |
2859 | |
2860 | if (aoh) { |
2861 | if (!ao_tmp) |
2862 | *aoh = NULL; |
2863 | else |
2864 | *aoh = (struct tcp_ao_hdr *)(ao_tmp - 2); |
2865 | } |
2866 | |
2867 | return 0; |
2868 | } |
2869 | |
2870 | static inline bool tcp_ao_required(struct sock *sk, const void *saddr, |
2871 | int family, int l3index, bool stat_inc) |
2872 | { |
2873 | #ifdef CONFIG_TCP_AO |
2874 | struct tcp_ao_info *ao_info; |
2875 | struct tcp_ao_key *ao_key; |
2876 | |
2877 | if (!static_branch_unlikely(&tcp_ao_needed.key)) |
2878 | return false; |
2879 | |
2880 | ao_info = rcu_dereference_check(tcp_sk(sk)->ao_info, |
2881 | lockdep_sock_is_held(sk)); |
2882 | if (!ao_info) |
2883 | return false; |
2884 | |
2885 | ao_key = tcp_ao_do_lookup(sk, l3index, addr: saddr, family, sndid: -1, rcvid: -1); |
2886 | if (ao_info->ao_required || ao_key) { |
2887 | if (stat_inc) { |
2888 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOREQUIRED); |
2889 | atomic64_inc(v: &ao_info->counters.ao_required); |
2890 | } |
2891 | return true; |
2892 | } |
2893 | #endif |
2894 | return false; |
2895 | } |
2896 | |
2897 | enum skb_drop_reason tcp_inbound_hash(struct sock *sk, |
2898 | const struct request_sock *req, const struct sk_buff *skb, |
2899 | const void *saddr, const void *daddr, |
2900 | int family, int dif, int sdif); |
2901 | |
2902 | #endif /* _TCP_H */ |
2903 |
Definitions
- tcp_under_memory_pressure
- before
- between
- tcp_wmem_free_skb
- tcp_dec_quickack_mode
- tcp_ecn_mode_any
- tcp_ecn_mode_rfc3168
- tcp_ecn_mode_accecn
- tcp_ecn_disabled
- tcp_ecn_mode_pending
- tcp_ecn_mode_set
- tcp_tw_status
- tcp_synack_type
- bpf_tcp_req_attrs
- tcp_synq_overflow
- tcp_synq_no_recent_overflow
- tcp_cookie_time
- tcp_ns_to_ts
- cookie_ecn_ok
- cookie_bpf_ok
- tcp_queue
- tcp_cleanup_skb
- tcp_add_receive_queue
- tcp_clear_xmit_timers
- tcp_bound_to_half_wnd
- tcp_rto_max
- tcp_bound_rto
- __tcp_set_rto
- __tcp_fast_path_on
- tcp_fast_path_on
- tcp_fast_path_check
- tcp_rto_min
- tcp_rto_min_us
- tcp_ca_dst_locked
- tcp_min_rtt
- tcp_receive_window
- tcp_clock_ns
- tcp_clock_us
- tcp_clock_ms
- tcp_clock_ts
- tcp_time_stamp_ms
- tcp_time_stamp_ts
- tcp_stamp_us_delta
- tcp_skb_timestamp_us
- tcp_skb_timestamp_ts
- tcp_tw_tsval
- tcp_rsk_tsval
- tcp_skb_cb_sacked_flags
- tcp_skb_cb
- tcp_v6_iif
- tcp_v6_iif_l3_slave
- tcp_v6_sdif
- tcp_v4_sdif
- tcp_skb_pcount
- tcp_skb_pcount_set
- tcp_skb_pcount_add
- tcp_skb_mss
- tcp_skb_can_collapse_to
- tcp_skb_can_collapse
- tcp_skb_can_collapse_rx
- tcp_ca_event
- tcp_ca_ack_event_flags
- ack_sample
- rate_sample
- tcp_congestion_ops
- tcp_ca_needs_ecn
- tcp_ca_event
- tcp_skb_sent_after
- tcp_is_sack
- tcp_is_reno
- tcp_left_out
- tcp_packets_in_flight
- tcp_snd_cwnd
- tcp_snd_cwnd_set
- tcp_in_slow_start
- tcp_in_initial_slowstart
- tcp_in_cwnd_reduction
- tcp_current_ssthresh
- tcp_max_tso_deferred_mss
- tcp_wnd_end
- tcp_is_cwnd_limited
- tcp_needs_internal_pacing
- tcp_pacing_delay
- tcp_reset_xmit_timer
- tcp_probe0_base
- tcp_probe0_when
- tcp_check_probe_timer
- tcp_init_wl
- tcp_update_wl
- tcp_v4_check
- tcp_checksum_complete
- tcp_sack_reset
- tcp_slow_start_after_idle_check
- __tcp_win_from_space
- tcp_win_from_space
- __tcp_space_from_win
- tcp_space_from_win
- tcp_scaling_ratio_init
- tcp_space
- tcp_full_space
- __tcp_adjust_rcv_ssthresh
- tcp_adjust_rcv_ssthresh
- tcp_rmem_pressure
- tcp_epollin_ready
- keepalive_intvl_when
- keepalive_time_when
- keepalive_probes
- keepalive_time_elapsed
- tcp_fin_time
- tcp_paws_check
- tcp_paws_reject
- tcp_mib_init
- tcp_clear_retrans_hints_partial
- tcp_clear_all_retrans_hints
- tcp_md5sig_key
- tcp_md5sig_info
- tcp4_pseudohdr
- tcp6_pseudohdr
- tcp_md5sum_block
- tcp_sigpool
- tcp_md5_do_lookup
- tcp_md5_do_lookup_any_l3index
- tcp_fastopen_request
- tcp_fastopen_context
- tcp_fastopen_get_ctx
- tcp_fastopen_cookie_match
- tcp_fastopen_context_len
- tcp_chrono
- tcp_skb_tsorted_anchor_cleanup
- tcp_rtx_queue_head
- tcp_rtx_queue_tail
- tcp_write_queue_tail
- tcp_send_head
- tcp_skb_is_last
- tcp_write_queue_empty
- tcp_rtx_queue_empty
- tcp_rtx_and_write_queues_empty
- tcp_add_write_queue_tail
- tcp_insert_write_queue_before
- tcp_unlink_write_queue
- tcp_rtx_queue_unlink
- tcp_rtx_queue_unlink_and_free
- tcp_write_collapse_fence
- tcp_push_pending_frames
- tcp_highest_sack_seq
- tcp_advance_highest_sack
- tcp_highest_sack
- tcp_highest_sack_reset
- tcp_highest_sack_replace
- inet_sk_transparent
- tcp_stream_is_thin
- tcp_seq_states
- tcp_seq_afinfo
- tcp_iter_state
- tcp_notsent_lowat
- tcp_sock_af_ops
- tcp_request_sock_ops
- cookie_init_sequence
- tcp_key
- tcp_get_current_key
- tcp_key_is_md5
- tcp_key_is_ao
- tcp_plb_state
- tcp_plb_init
- tcp_warn_once
- tcp_rto_delta_us
- tcp_v4_save_options
- skb_is_tcp_pure_ack
- skb_set_tcp_pure_ack
- tcp_inq
- tcp_segs_in
- tcp_listendrop
- tcp_ulp_ops
- bpf_skops_init_skb
- tcp_call_bpf
- tcp_call_bpf_2arg
- tcp_call_bpf_3arg
- tcp_timeout_init
- tcp_rwnd_init_bpf
- tcp_bpf_ca_needs_ecn
- tcp_bpf_rtt
- tcp_add_tx_delay
- tcp_transmit_time
- tcp_parse_auth_options
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