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 | |
30 | #include <net/inet_connection_sock.h> |
31 | #include <net/inet_timewait_sock.h> |
32 | #include <net/inet_hashtables.h> |
33 | #include <net/checksum.h> |
34 | #include <net/request_sock.h> |
35 | #include <net/sock_reuseport.h> |
36 | #include <net/sock.h> |
37 | #include <net/snmp.h> |
38 | #include <net/ip.h> |
39 | #include <net/tcp_states.h> |
40 | #include <net/tcp_ao.h> |
41 | #include <net/inet_ecn.h> |
42 | #include <net/dst.h> |
43 | #include <net/mptcp.h> |
44 | |
45 | #include <linux/seq_file.h> |
46 | #include <linux/memcontrol.h> |
47 | #include <linux/bpf-cgroup.h> |
48 | #include <linux/siphash.h> |
49 | |
50 | extern struct inet_hashinfo tcp_hashinfo; |
51 | |
52 | DECLARE_PER_CPU(unsigned int, tcp_orphan_count); |
53 | int tcp_orphan_count_sum(void); |
54 | |
55 | void tcp_time_wait(struct sock *sk, int state, int timeo); |
56 | |
57 | #define L1_CACHE_ALIGN(128 + MAX_HEADER) |
58 | #define MAX_TCP_OPTION_SPACE 40 |
59 | #define TCP_MIN_SND_MSS 48 |
60 | #define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE) |
61 | |
62 | /* |
63 | * Never offer a window over 32767 without using window scaling. Some |
64 | * poor stacks do signed 16bit maths! |
65 | */ |
66 | #define MAX_TCP_WINDOW 32767U |
67 | |
68 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ |
69 | #define TCP_MIN_MSS 88U |
70 | |
71 | /* The initial MTU to use for probing */ |
72 | #define TCP_BASE_MSS 1024 |
73 | |
74 | /* probing interval, default to 10 minutes as per RFC4821 */ |
75 | #define TCP_PROBE_INTERVAL 600 |
76 | |
77 | /* Specify interval when tcp mtu probing will stop */ |
78 | #define TCP_PROBE_THRESHOLD 8 |
79 | |
80 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
81 | #define TCP_FASTRETRANS_THRESH 3 |
82 | |
83 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
84 | #define TCP_MAX_QUICKACKS 16U |
85 | |
86 | /* Maximal number of window scale according to RFC1323 */ |
87 | #define TCP_MAX_WSCALE 14U |
88 | |
89 | /* urg_data states */ |
90 | #define TCP_URG_VALID 0x0100 |
91 | #define TCP_URG_NOTYET 0x0200 |
92 | #define TCP_URG_READ 0x0400 |
93 | |
94 | #define TCP_RETR1 3 /* |
95 | * This is how many retries it does before it |
96 | * tries to figure out if the gateway is |
97 | * down. Minimal RFC value is 3; it corresponds |
98 | * to ~3sec-8min depending on RTO. |
99 | */ |
100 | |
101 | #define TCP_RETR2 15 /* |
102 | * This should take at least |
103 | * 90 minutes to time out. |
104 | * RFC1122 says that the limit is 100 sec. |
105 | * 15 is ~13-30min depending on RTO. |
106 | */ |
107 | |
108 | #define TCP_SYN_RETRIES 6 /* This is how many retries are done |
109 | * when active opening a connection. |
110 | * RFC1122 says the minimum retry MUST |
111 | * be at least 180secs. Nevertheless |
112 | * this value is corresponding to |
113 | * 63secs of retransmission with the |
114 | * current initial RTO. |
115 | */ |
116 | |
117 | #define TCP_SYNACK_RETRIES 5 /* This is how may retries are done |
118 | * when passive opening a connection. |
119 | * This is corresponding to 31secs of |
120 | * retransmission with the current |
121 | * initial RTO. |
122 | */ |
123 | |
124 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
125 | * state, about 60 seconds */ |
126 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN |
127 | /* BSD style FIN_WAIT2 deadlock breaker. |
128 | * It used to be 3min, new value is 60sec, |
129 | * to combine FIN-WAIT-2 timeout with |
130 | * TIME-WAIT timer. |
131 | */ |
132 | #define TCP_FIN_TIMEOUT_MAX (120 * HZ) /* max TCP_LINGER2 value (two minutes) */ |
133 | |
134 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ |
135 | static_assert((1 << ATO_BITS) > TCP_DELACK_MAX); |
136 | |
137 | #if HZ >= 100 |
138 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ |
139 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) |
140 | #else |
141 | #define TCP_DELACK_MIN 4U |
142 | #define TCP_ATO_MIN 4U |
143 | #endif |
144 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) |
145 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) |
146 | #define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ |
147 | |
148 | #define TCP_TIMEOUT_MIN_US (2*USEC_PER_MSEC) /* Min TCP timeout in microsecs */ |
149 | |
150 | #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ |
151 | #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now |
152 | * used as a fallback RTO for the |
153 | * initial data transmission if no |
154 | * valid RTT sample has been acquired, |
155 | * most likely due to retrans in 3WHS. |
156 | */ |
157 | |
158 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes |
159 | * for local resources. |
160 | */ |
161 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
162 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ |
163 | #define TCP_KEEPALIVE_INTVL (75*HZ) |
164 | |
165 | #define MAX_TCP_KEEPIDLE 32767 |
166 | #define MAX_TCP_KEEPINTVL 32767 |
167 | #define MAX_TCP_KEEPCNT 127 |
168 | #define MAX_TCP_SYNCNT 127 |
169 | |
170 | /* Ensure that TCP PAWS checks are relaxed after ~2147 seconds |
171 | * to avoid overflows. This assumes a clock smaller than 1 Mhz. |
172 | * Default clock is 1 Khz, tcp_usec_ts uses 1 Mhz. |
173 | */ |
174 | #define TCP_PAWS_WRAP (INT_MAX / USEC_PER_SEC) |
175 | |
176 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated |
177 | * after this time. It should be equal |
178 | * (or greater than) TCP_TIMEWAIT_LEN |
179 | * to provide reliability equal to one |
180 | * provided by timewait state. |
181 | */ |
182 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host |
183 | * timestamps. It must be less than |
184 | * minimal timewait lifetime. |
185 | */ |
186 | /* |
187 | * TCP option |
188 | */ |
189 | |
190 | #define TCPOPT_NOP 1 /* Padding */ |
191 | #define TCPOPT_EOL 0 /* End of options */ |
192 | #define TCPOPT_MSS 2 /* Segment size negotiating */ |
193 | #define TCPOPT_WINDOW 3 /* Window scaling */ |
194 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ |
195 | #define TCPOPT_SACK 5 /* SACK Block */ |
196 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ |
197 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
198 | #define TCPOPT_AO 29 /* Authentication Option (RFC5925) */ |
199 | #define TCPOPT_MPTCP 30 /* Multipath TCP (RFC6824) */ |
200 | #define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ |
201 | #define TCPOPT_EXP 254 /* Experimental */ |
202 | /* Magic number to be after the option value for sharing TCP |
203 | * experimental options. See draft-ietf-tcpm-experimental-options-00.txt |
204 | */ |
205 | #define TCPOPT_FASTOPEN_MAGIC 0xF989 |
206 | #define TCPOPT_SMC_MAGIC 0xE2D4C3D9 |
207 | |
208 | /* |
209 | * TCP option lengths |
210 | */ |
211 | |
212 | #define TCPOLEN_MSS 4 |
213 | #define TCPOLEN_WINDOW 3 |
214 | #define TCPOLEN_SACK_PERM 2 |
215 | #define TCPOLEN_TIMESTAMP 10 |
216 | #define TCPOLEN_MD5SIG 18 |
217 | #define TCPOLEN_FASTOPEN_BASE 2 |
218 | #define TCPOLEN_EXP_FASTOPEN_BASE 4 |
219 | #define TCPOLEN_EXP_SMC_BASE 6 |
220 | |
221 | /* But this is what stacks really send out. */ |
222 | #define TCPOLEN_TSTAMP_ALIGNED 12 |
223 | #define TCPOLEN_WSCALE_ALIGNED 4 |
224 | #define TCPOLEN_SACKPERM_ALIGNED 4 |
225 | #define TCPOLEN_SACK_BASE 2 |
226 | #define TCPOLEN_SACK_BASE_ALIGNED 4 |
227 | #define TCPOLEN_SACK_PERBLOCK 8 |
228 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
229 | #define TCPOLEN_MSS_ALIGNED 4 |
230 | #define TCPOLEN_EXP_SMC_BASE_ALIGNED 8 |
231 | |
232 | /* Flags in tp->nonagle */ |
233 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ |
234 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ |
235 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
236 | |
237 | /* TCP thin-stream limits */ |
238 | #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ |
239 | |
240 | /* TCP initial congestion window as per rfc6928 */ |
241 | #define TCP_INIT_CWND 10 |
242 | |
243 | /* Bit Flags for sysctl_tcp_fastopen */ |
244 | #define TFO_CLIENT_ENABLE 1 |
245 | #define TFO_SERVER_ENABLE 2 |
246 | #define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ |
247 | |
248 | /* Accept SYN data w/o any cookie option */ |
249 | #define TFO_SERVER_COOKIE_NOT_REQD 0x200 |
250 | |
251 | /* Force enable TFO on all listeners, i.e., not requiring the |
252 | * TCP_FASTOPEN socket option. |
253 | */ |
254 | #define TFO_SERVER_WO_SOCKOPT1 0x400 |
255 | |
256 | |
257 | /* sysctl variables for tcp */ |
258 | extern int sysctl_tcp_max_orphans; |
259 | extern long sysctl_tcp_mem[3]; |
260 | |
261 | #define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ |
262 | #define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */ |
263 | #define TCP_RACK_NO_DUPTHRESH 0x4 /* Do not use DUPACK threshold in RACK */ |
264 | |
265 | extern atomic_long_t tcp_memory_allocated; |
266 | DECLARE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc); |
267 | |
268 | extern struct percpu_counter tcp_sockets_allocated; |
269 | extern unsigned long tcp_memory_pressure; |
270 | |
271 | /* optimized version of sk_under_memory_pressure() for TCP sockets */ |
272 | static inline bool tcp_under_memory_pressure(const struct sock *sk) |
273 | { |
274 | if (mem_cgroup_sockets_enabled && sk->sk_memcg && |
275 | mem_cgroup_under_socket_pressure(memcg: sk->sk_memcg)) |
276 | return true; |
277 | |
278 | return READ_ONCE(tcp_memory_pressure); |
279 | } |
280 | /* |
281 | * The next routines deal with comparing 32 bit unsigned ints |
282 | * and worry about wraparound (automatic with unsigned arithmetic). |
283 | */ |
284 | |
285 | static inline bool before(__u32 seq1, __u32 seq2) |
286 | { |
287 | return (__s32)(seq1-seq2) < 0; |
288 | } |
289 | #define after(seq2, seq1) before(seq1, seq2) |
290 | |
291 | /* is s2<=s1<=s3 ? */ |
292 | static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) |
293 | { |
294 | return seq3 - seq2 >= seq1 - seq2; |
295 | } |
296 | |
297 | static inline bool tcp_out_of_memory(struct sock *sk) |
298 | { |
299 | if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && |
300 | sk_memory_allocated(sk) > sk_prot_mem_limits(sk, index: 2)) |
301 | return true; |
302 | return false; |
303 | } |
304 | |
305 | static inline void tcp_wmem_free_skb(struct sock *sk, struct sk_buff *skb) |
306 | { |
307 | sk_wmem_queued_add(sk, val: -skb->truesize); |
308 | if (!skb_zcopy_pure(skb)) |
309 | sk_mem_uncharge(sk, size: skb->truesize); |
310 | else |
311 | sk_mem_uncharge(sk, SKB_TRUESIZE(skb_end_offset(skb))); |
312 | __kfree_skb(skb); |
313 | } |
314 | |
315 | void sk_forced_mem_schedule(struct sock *sk, int size); |
316 | |
317 | bool tcp_check_oom(struct sock *sk, int shift); |
318 | |
319 | |
320 | extern struct proto tcp_prot; |
321 | |
322 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
323 | #define __TCP_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
324 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) |
325 | #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) |
326 | |
327 | void tcp_tasklet_init(void); |
328 | |
329 | int tcp_v4_err(struct sk_buff *skb, u32); |
330 | |
331 | void tcp_shutdown(struct sock *sk, int how); |
332 | |
333 | int tcp_v4_early_demux(struct sk_buff *skb); |
334 | int tcp_v4_rcv(struct sk_buff *skb); |
335 | |
336 | void tcp_remove_empty_skb(struct sock *sk); |
337 | int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); |
338 | int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size); |
339 | int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied, |
340 | size_t size, struct ubuf_info *uarg); |
341 | void tcp_splice_eof(struct socket *sock); |
342 | int tcp_send_mss(struct sock *sk, int *size_goal, int flags); |
343 | int tcp_wmem_schedule(struct sock *sk, int copy); |
344 | void tcp_push(struct sock *sk, int flags, int mss_now, int nonagle, |
345 | int size_goal); |
346 | void tcp_release_cb(struct sock *sk); |
347 | void tcp_wfree(struct sk_buff *skb); |
348 | void tcp_write_timer_handler(struct sock *sk); |
349 | void tcp_delack_timer_handler(struct sock *sk); |
350 | int tcp_ioctl(struct sock *sk, int cmd, int *karg); |
351 | int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); |
352 | void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); |
353 | void tcp_rcv_space_adjust(struct sock *sk); |
354 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); |
355 | void tcp_twsk_destructor(struct sock *sk); |
356 | void tcp_twsk_purge(struct list_head *net_exit_list, int family); |
357 | ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, |
358 | struct pipe_inode_info *pipe, size_t len, |
359 | unsigned int flags); |
360 | struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, gfp_t gfp, |
361 | bool force_schedule); |
362 | |
363 | static inline void tcp_dec_quickack_mode(struct sock *sk) |
364 | { |
365 | struct inet_connection_sock *icsk = inet_csk(sk); |
366 | |
367 | if (icsk->icsk_ack.quick) { |
368 | /* How many ACKs S/ACKing new data have we sent? */ |
369 | const unsigned int pkts = inet_csk_ack_scheduled(sk) ? 1 : 0; |
370 | |
371 | if (pkts >= icsk->icsk_ack.quick) { |
372 | icsk->icsk_ack.quick = 0; |
373 | /* Leaving quickack mode we deflate ATO. */ |
374 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
375 | } else |
376 | icsk->icsk_ack.quick -= pkts; |
377 | } |
378 | } |
379 | |
380 | #define TCP_ECN_OK 1 |
381 | #define TCP_ECN_QUEUE_CWR 2 |
382 | #define TCP_ECN_DEMAND_CWR 4 |
383 | #define TCP_ECN_SEEN 8 |
384 | |
385 | enum tcp_tw_status { |
386 | TCP_TW_SUCCESS = 0, |
387 | TCP_TW_RST = 1, |
388 | TCP_TW_ACK = 2, |
389 | TCP_TW_SYN = 3 |
390 | }; |
391 | |
392 | |
393 | enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
394 | struct sk_buff *skb, |
395 | const struct tcphdr *th); |
396 | struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, |
397 | struct request_sock *req, bool fastopen, |
398 | bool *lost_race); |
399 | int tcp_child_process(struct sock *parent, struct sock *child, |
400 | struct sk_buff *skb); |
401 | void tcp_enter_loss(struct sock *sk); |
402 | void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int newly_lost, int flag); |
403 | void tcp_clear_retrans(struct tcp_sock *tp); |
404 | void tcp_update_metrics(struct sock *sk); |
405 | void tcp_init_metrics(struct sock *sk); |
406 | void tcp_metrics_init(void); |
407 | bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst); |
408 | void __tcp_close(struct sock *sk, long timeout); |
409 | void tcp_close(struct sock *sk, long timeout); |
410 | void tcp_init_sock(struct sock *sk); |
411 | void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb); |
412 | __poll_t tcp_poll(struct file *file, struct socket *sock, |
413 | struct poll_table_struct *wait); |
414 | int do_tcp_getsockopt(struct sock *sk, int level, |
415 | int optname, sockptr_t optval, sockptr_t optlen); |
416 | int tcp_getsockopt(struct sock *sk, int level, int optname, |
417 | char __user *optval, int __user *optlen); |
418 | bool tcp_bpf_bypass_getsockopt(int level, int optname); |
419 | int do_tcp_setsockopt(struct sock *sk, int level, int optname, |
420 | sockptr_t optval, unsigned int optlen); |
421 | int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, |
422 | unsigned int optlen); |
423 | void tcp_set_keepalive(struct sock *sk, int val); |
424 | void tcp_syn_ack_timeout(const struct request_sock *req); |
425 | int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, |
426 | int flags, int *addr_len); |
427 | int tcp_set_rcvlowat(struct sock *sk, int val); |
428 | int tcp_set_window_clamp(struct sock *sk, int val); |
429 | void tcp_update_recv_tstamps(struct sk_buff *skb, |
430 | struct scm_timestamping_internal *tss); |
431 | void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, |
432 | struct scm_timestamping_internal *tss); |
433 | void tcp_data_ready(struct sock *sk); |
434 | #ifdef CONFIG_MMU |
435 | int tcp_mmap(struct file *file, struct socket *sock, |
436 | struct vm_area_struct *vma); |
437 | #endif |
438 | void tcp_parse_options(const struct net *net, const struct sk_buff *skb, |
439 | struct tcp_options_received *opt_rx, |
440 | int estab, struct tcp_fastopen_cookie *foc); |
441 | |
442 | /* |
443 | * BPF SKB-less helpers |
444 | */ |
445 | u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, |
446 | struct tcphdr *th, u32 *cookie); |
447 | u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, |
448 | struct tcphdr *th, u32 *cookie); |
449 | u16 tcp_parse_mss_option(const struct tcphdr *th, u16 user_mss); |
450 | u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, |
451 | const struct tcp_request_sock_ops *af_ops, |
452 | struct sock *sk, struct tcphdr *th); |
453 | /* |
454 | * TCP v4 functions exported for the inet6 API |
455 | */ |
456 | |
457 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
458 | void tcp_v4_mtu_reduced(struct sock *sk); |
459 | void tcp_req_err(struct sock *sk, u32 seq, bool abort); |
460 | void tcp_ld_RTO_revert(struct sock *sk, u32 seq); |
461 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); |
462 | struct sock *tcp_create_openreq_child(const struct sock *sk, |
463 | struct request_sock *req, |
464 | struct sk_buff *skb); |
465 | void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); |
466 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
467 | struct request_sock *req, |
468 | struct dst_entry *dst, |
469 | struct request_sock *req_unhash, |
470 | bool *own_req); |
471 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); |
472 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); |
473 | int tcp_connect(struct sock *sk); |
474 | enum tcp_synack_type { |
475 | TCP_SYNACK_NORMAL, |
476 | TCP_SYNACK_FASTOPEN, |
477 | TCP_SYNACK_COOKIE, |
478 | }; |
479 | struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, |
480 | struct request_sock *req, |
481 | struct tcp_fastopen_cookie *foc, |
482 | enum tcp_synack_type synack_type, |
483 | struct sk_buff *syn_skb); |
484 | int tcp_disconnect(struct sock *sk, int flags); |
485 | |
486 | void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); |
487 | int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); |
488 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); |
489 | |
490 | /* From syncookies.c */ |
491 | struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, |
492 | struct request_sock *req, |
493 | struct dst_entry *dst, u32 tsoff); |
494 | int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, |
495 | u32 cookie); |
496 | struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); |
497 | struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, |
498 | const struct tcp_request_sock_ops *af_ops, |
499 | struct sock *sk, struct sk_buff *skb); |
500 | #ifdef CONFIG_SYN_COOKIES |
501 | |
502 | /* Syncookies use a monotonic timer which increments every 60 seconds. |
503 | * This counter is used both as a hash input and partially encoded into |
504 | * the cookie value. A cookie is only validated further if the delta |
505 | * between the current counter value and the encoded one is less than this, |
506 | * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if |
507 | * the counter advances immediately after a cookie is generated). |
508 | */ |
509 | #define MAX_SYNCOOKIE_AGE 2 |
510 | #define TCP_SYNCOOKIE_PERIOD (60 * HZ) |
511 | #define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) |
512 | |
513 | /* syncookies: remember time of last synqueue overflow |
514 | * But do not dirty this field too often (once per second is enough) |
515 | * It is racy as we do not hold a lock, but race is very minor. |
516 | */ |
517 | static inline void tcp_synq_overflow(const struct sock *sk) |
518 | { |
519 | unsigned int last_overflow; |
520 | unsigned int now = jiffies; |
521 | |
522 | if (sk->sk_reuseport) { |
523 | struct sock_reuseport *reuse; |
524 | |
525 | reuse = rcu_dereference(sk->sk_reuseport_cb); |
526 | if (likely(reuse)) { |
527 | last_overflow = READ_ONCE(reuse->synq_overflow_ts); |
528 | if (!time_between32(now, last_overflow, |
529 | last_overflow + HZ)) |
530 | WRITE_ONCE(reuse->synq_overflow_ts, now); |
531 | return; |
532 | } |
533 | } |
534 | |
535 | last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); |
536 | if (!time_between32(now, last_overflow, last_overflow + HZ)) |
537 | WRITE_ONCE(tcp_sk_rw(sk)->rx_opt.ts_recent_stamp, now); |
538 | } |
539 | |
540 | /* syncookies: no recent synqueue overflow on this listening socket? */ |
541 | static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) |
542 | { |
543 | unsigned int last_overflow; |
544 | unsigned int now = jiffies; |
545 | |
546 | if (sk->sk_reuseport) { |
547 | struct sock_reuseport *reuse; |
548 | |
549 | reuse = rcu_dereference(sk->sk_reuseport_cb); |
550 | if (likely(reuse)) { |
551 | last_overflow = READ_ONCE(reuse->synq_overflow_ts); |
552 | return !time_between32(now, last_overflow - HZ, |
553 | last_overflow + |
554 | TCP_SYNCOOKIE_VALID); |
555 | } |
556 | } |
557 | |
558 | last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); |
559 | |
560 | /* If last_overflow <= jiffies <= last_overflow + TCP_SYNCOOKIE_VALID, |
561 | * then we're under synflood. However, we have to use |
562 | * 'last_overflow - HZ' as lower bound. That's because a concurrent |
563 | * tcp_synq_overflow() could update .ts_recent_stamp after we read |
564 | * jiffies but before we store .ts_recent_stamp into last_overflow, |
565 | * which could lead to rejecting a valid syncookie. |
566 | */ |
567 | return !time_between32(now, last_overflow - HZ, |
568 | last_overflow + TCP_SYNCOOKIE_VALID); |
569 | } |
570 | |
571 | static inline u32 tcp_cookie_time(void) |
572 | { |
573 | u64 val = get_jiffies_64(); |
574 | |
575 | do_div(val, TCP_SYNCOOKIE_PERIOD); |
576 | return val; |
577 | } |
578 | |
579 | u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, |
580 | u16 *mssp); |
581 | __u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); |
582 | u64 cookie_init_timestamp(struct request_sock *req, u64 now); |
583 | bool cookie_timestamp_decode(const struct net *net, |
584 | struct tcp_options_received *opt); |
585 | bool cookie_ecn_ok(const struct tcp_options_received *opt, |
586 | const struct net *net, const struct dst_entry *dst); |
587 | |
588 | /* From net/ipv6/syncookies.c */ |
589 | int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, |
590 | u32 cookie); |
591 | struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); |
592 | |
593 | u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, |
594 | const struct tcphdr *th, u16 *mssp); |
595 | __u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); |
596 | #endif |
597 | /* tcp_output.c */ |
598 | |
599 | void tcp_skb_entail(struct sock *sk, struct sk_buff *skb); |
600 | void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb); |
601 | void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
602 | int nonagle); |
603 | int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
604 | int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
605 | void tcp_retransmit_timer(struct sock *sk); |
606 | void tcp_xmit_retransmit_queue(struct sock *); |
607 | void tcp_simple_retransmit(struct sock *); |
608 | void tcp_enter_recovery(struct sock *sk, bool ece_ack); |
609 | int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
610 | enum tcp_queue { |
611 | TCP_FRAG_IN_WRITE_QUEUE, |
612 | TCP_FRAG_IN_RTX_QUEUE, |
613 | }; |
614 | int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, |
615 | struct sk_buff *skb, u32 len, |
616 | unsigned int mss_now, gfp_t gfp); |
617 | |
618 | void tcp_send_probe0(struct sock *); |
619 | int tcp_write_wakeup(struct sock *, int mib); |
620 | void tcp_send_fin(struct sock *sk); |
621 | void tcp_send_active_reset(struct sock *sk, gfp_t priority); |
622 | int tcp_send_synack(struct sock *); |
623 | void tcp_push_one(struct sock *, unsigned int mss_now); |
624 | void __tcp_send_ack(struct sock *sk, u32 rcv_nxt); |
625 | void tcp_send_ack(struct sock *sk); |
626 | void tcp_send_delayed_ack(struct sock *sk); |
627 | void tcp_send_loss_probe(struct sock *sk); |
628 | bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto); |
629 | void tcp_skb_collapse_tstamp(struct sk_buff *skb, |
630 | const struct sk_buff *next_skb); |
631 | |
632 | /* tcp_input.c */ |
633 | void tcp_rearm_rto(struct sock *sk); |
634 | void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); |
635 | void tcp_reset(struct sock *sk, struct sk_buff *skb); |
636 | void tcp_fin(struct sock *sk); |
637 | void tcp_check_space(struct sock *sk); |
638 | void tcp_sack_compress_send_ack(struct sock *sk); |
639 | |
640 | /* tcp_timer.c */ |
641 | void tcp_init_xmit_timers(struct sock *); |
642 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
643 | { |
644 | if (hrtimer_try_to_cancel(timer: &tcp_sk(sk)->pacing_timer) == 1) |
645 | __sock_put(sk); |
646 | |
647 | if (hrtimer_try_to_cancel(timer: &tcp_sk(sk)->compressed_ack_timer) == 1) |
648 | __sock_put(sk); |
649 | |
650 | inet_csk_clear_xmit_timers(sk); |
651 | } |
652 | |
653 | unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
654 | unsigned int tcp_current_mss(struct sock *sk); |
655 | u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when); |
656 | |
657 | /* Bound MSS / TSO packet size with the half of the window */ |
658 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) |
659 | { |
660 | int cutoff; |
661 | |
662 | /* When peer uses tiny windows, there is no use in packetizing |
663 | * to sub-MSS pieces for the sake of SWS or making sure there |
664 | * are enough packets in the pipe for fast recovery. |
665 | * |
666 | * On the other hand, for extremely large MSS devices, handling |
667 | * smaller than MSS windows in this way does make sense. |
668 | */ |
669 | if (tp->max_window > TCP_MSS_DEFAULT) |
670 | cutoff = (tp->max_window >> 1); |
671 | else |
672 | cutoff = tp->max_window; |
673 | |
674 | if (cutoff && pktsize > cutoff) |
675 | return max_t(int, cutoff, 68U - tp->tcp_header_len); |
676 | else |
677 | return pktsize; |
678 | } |
679 | |
680 | /* tcp.c */ |
681 | void tcp_get_info(struct sock *, struct tcp_info *); |
682 | |
683 | /* Read 'sendfile()'-style from a TCP socket */ |
684 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
685 | sk_read_actor_t recv_actor); |
686 | int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor); |
687 | struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off); |
688 | void tcp_read_done(struct sock *sk, size_t len); |
689 | |
690 | void tcp_initialize_rcv_mss(struct sock *sk); |
691 | |
692 | int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
693 | int tcp_mss_to_mtu(struct sock *sk, int mss); |
694 | void tcp_mtup_init(struct sock *sk); |
695 | |
696 | static inline void tcp_bound_rto(const struct sock *sk) |
697 | { |
698 | if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) |
699 | inet_csk(sk)->icsk_rto = TCP_RTO_MAX; |
700 | } |
701 | |
702 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) |
703 | { |
704 | return usecs_to_jiffies(u: (tp->srtt_us >> 3) + tp->rttvar_us); |
705 | } |
706 | |
707 | static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
708 | { |
709 | /* mptcp hooks are only on the slow path */ |
710 | if (sk_is_mptcp(sk: (struct sock *)tp)) |
711 | return; |
712 | |
713 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | |
714 | ntohl(TCP_FLAG_ACK) | |
715 | snd_wnd); |
716 | } |
717 | |
718 | static inline void tcp_fast_path_on(struct tcp_sock *tp) |
719 | { |
720 | __tcp_fast_path_on(tp, snd_wnd: tp->snd_wnd >> tp->rx_opt.snd_wscale); |
721 | } |
722 | |
723 | static inline void tcp_fast_path_check(struct sock *sk) |
724 | { |
725 | struct tcp_sock *tp = tcp_sk(sk); |
726 | |
727 | if (RB_EMPTY_ROOT(&tp->out_of_order_queue) && |
728 | tp->rcv_wnd && |
729 | atomic_read(v: &sk->sk_rmem_alloc) < sk->sk_rcvbuf && |
730 | !tp->urg_data) |
731 | tcp_fast_path_on(tp); |
732 | } |
733 | |
734 | u32 tcp_delack_max(const struct sock *sk); |
735 | |
736 | /* Compute the actual rto_min value */ |
737 | static inline u32 tcp_rto_min(const struct sock *sk) |
738 | { |
739 | const struct dst_entry *dst = __sk_dst_get(sk); |
740 | u32 rto_min = inet_csk(sk)->icsk_rto_min; |
741 | |
742 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) |
743 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); |
744 | return rto_min; |
745 | } |
746 | |
747 | static inline u32 tcp_rto_min_us(const struct sock *sk) |
748 | { |
749 | return jiffies_to_usecs(j: tcp_rto_min(sk)); |
750 | } |
751 | |
752 | static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) |
753 | { |
754 | return dst_metric_locked(dst, RTAX_CC_ALGO); |
755 | } |
756 | |
757 | /* Minimum RTT in usec. ~0 means not available. */ |
758 | static inline u32 tcp_min_rtt(const struct tcp_sock *tp) |
759 | { |
760 | return minmax_get(m: &tp->rtt_min); |
761 | } |
762 | |
763 | /* Compute the actual receive window we are currently advertising. |
764 | * Rcv_nxt can be after the window if our peer push more data |
765 | * than the offered window. |
766 | */ |
767 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
768 | { |
769 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; |
770 | |
771 | if (win < 0) |
772 | win = 0; |
773 | return (u32) win; |
774 | } |
775 | |
776 | /* Choose a new window, without checks for shrinking, and without |
777 | * scaling applied to the result. The caller does these things |
778 | * if necessary. This is a "raw" window selection. |
779 | */ |
780 | u32 __tcp_select_window(struct sock *sk); |
781 | |
782 | void tcp_send_window_probe(struct sock *sk); |
783 | |
784 | /* TCP uses 32bit jiffies to save some space. |
785 | * Note that this is different from tcp_time_stamp, which |
786 | * historically has been the same until linux-4.13. |
787 | */ |
788 | #define tcp_jiffies32 ((u32)jiffies) |
789 | |
790 | /* |
791 | * Deliver a 32bit value for TCP timestamp option (RFC 7323) |
792 | * It is no longer tied to jiffies, but to 1 ms clock. |
793 | * Note: double check if you want to use tcp_jiffies32 instead of this. |
794 | */ |
795 | #define TCP_TS_HZ 1000 |
796 | |
797 | static inline u64 tcp_clock_ns(void) |
798 | { |
799 | return ktime_get_ns(); |
800 | } |
801 | |
802 | static inline u64 tcp_clock_us(void) |
803 | { |
804 | return div_u64(dividend: tcp_clock_ns(), NSEC_PER_USEC); |
805 | } |
806 | |
807 | static inline u64 tcp_clock_ms(void) |
808 | { |
809 | return div_u64(dividend: tcp_clock_ns(), NSEC_PER_MSEC); |
810 | } |
811 | |
812 | /* TCP Timestamp included in TS option (RFC 1323) can either use ms |
813 | * or usec resolution. Each socket carries a flag to select one or other |
814 | * resolution, as the route attribute could change anytime. |
815 | * Each flow must stick to initial resolution. |
816 | */ |
817 | static inline u32 tcp_clock_ts(bool usec_ts) |
818 | { |
819 | return usec_ts ? tcp_clock_us() : tcp_clock_ms(); |
820 | } |
821 | |
822 | static inline u32 tcp_time_stamp_ms(const struct tcp_sock *tp) |
823 | { |
824 | return div_u64(dividend: tp->tcp_mstamp, USEC_PER_MSEC); |
825 | } |
826 | |
827 | static inline u32 tcp_time_stamp_ts(const struct tcp_sock *tp) |
828 | { |
829 | if (tp->tcp_usec_ts) |
830 | return tp->tcp_mstamp; |
831 | return tcp_time_stamp_ms(tp); |
832 | } |
833 | |
834 | void tcp_mstamp_refresh(struct tcp_sock *tp); |
835 | |
836 | static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) |
837 | { |
838 | return max_t(s64, t1 - t0, 0); |
839 | } |
840 | |
841 | /* provide the departure time in us unit */ |
842 | static inline u64 tcp_skb_timestamp_us(const struct sk_buff *skb) |
843 | { |
844 | return div_u64(dividend: skb->skb_mstamp_ns, NSEC_PER_USEC); |
845 | } |
846 | |
847 | /* Provide skb TSval in usec or ms unit */ |
848 | static inline u32 tcp_skb_timestamp_ts(bool usec_ts, const struct sk_buff *skb) |
849 | { |
850 | if (usec_ts) |
851 | return tcp_skb_timestamp_us(skb); |
852 | |
853 | return div_u64(dividend: skb->skb_mstamp_ns, NSEC_PER_MSEC); |
854 | } |
855 | |
856 | static inline u32 tcp_tw_tsval(const struct tcp_timewait_sock *tcptw) |
857 | { |
858 | return tcp_clock_ts(usec_ts: tcptw->tw_sk.tw_usec_ts) + tcptw->tw_ts_offset; |
859 | } |
860 | |
861 | static inline u32 tcp_rsk_tsval(const struct tcp_request_sock *treq) |
862 | { |
863 | return tcp_clock_ts(usec_ts: treq->req_usec_ts) + treq->ts_off; |
864 | } |
865 | |
866 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
867 | |
868 | #define TCPHDR_FIN 0x01 |
869 | #define TCPHDR_SYN 0x02 |
870 | #define TCPHDR_RST 0x04 |
871 | #define TCPHDR_PSH 0x08 |
872 | #define TCPHDR_ACK 0x10 |
873 | #define TCPHDR_URG 0x20 |
874 | #define TCPHDR_ECE 0x40 |
875 | #define TCPHDR_CWR 0x80 |
876 | |
877 | #define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) |
878 | |
879 | /* This is what the send packet queuing engine uses to pass |
880 | * TCP per-packet control information to the transmission code. |
881 | * We also store the host-order sequence numbers in here too. |
882 | * This is 44 bytes if IPV6 is enabled. |
883 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. |
884 | */ |
885 | struct tcp_skb_cb { |
886 | __u32 seq; /* Starting sequence number */ |
887 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ |
888 | union { |
889 | /* Note : tcp_tw_isn is used in input path only |
890 | * (isn chosen by tcp_timewait_state_process()) |
891 | * |
892 | * tcp_gso_segs/size are used in write queue only, |
893 | * cf tcp_skb_pcount()/tcp_skb_mss() |
894 | */ |
895 | __u32 tcp_tw_isn; |
896 | struct { |
897 | u16 tcp_gso_segs; |
898 | u16 tcp_gso_size; |
899 | }; |
900 | }; |
901 | __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ |
902 | |
903 | __u8 sacked; /* State flags for SACK. */ |
904 | #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ |
905 | #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ |
906 | #define TCPCB_LOST 0x04 /* SKB is lost */ |
907 | #define TCPCB_TAGBITS 0x07 /* All tag bits */ |
908 | #define TCPCB_REPAIRED 0x10 /* SKB repaired (no skb_mstamp_ns) */ |
909 | #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ |
910 | #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS| \ |
911 | TCPCB_REPAIRED) |
912 | |
913 | __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ |
914 | __u8 txstamp_ack:1, /* Record TX timestamp for ack? */ |
915 | eor:1, /* Is skb MSG_EOR marked? */ |
916 | has_rxtstamp:1, /* SKB has a RX timestamp */ |
917 | unused:5; |
918 | __u32 ack_seq; /* Sequence number ACK'd */ |
919 | union { |
920 | struct { |
921 | #define TCPCB_DELIVERED_CE_MASK ((1U<<20) - 1) |
922 | /* There is space for up to 24 bytes */ |
923 | __u32 is_app_limited:1, /* cwnd not fully used? */ |
924 | delivered_ce:20, |
925 | unused:11; |
926 | /* pkts S/ACKed so far upon tx of skb, incl retrans: */ |
927 | __u32 delivered; |
928 | /* start of send pipeline phase */ |
929 | u64 first_tx_mstamp; |
930 | /* when we reached the "delivered" count */ |
931 | u64 delivered_mstamp; |
932 | } tx; /* only used for outgoing skbs */ |
933 | union { |
934 | struct inet_skb_parm h4; |
935 | #if IS_ENABLED(CONFIG_IPV6) |
936 | struct inet6_skb_parm h6; |
937 | #endif |
938 | } ; /* For incoming skbs */ |
939 | }; |
940 | }; |
941 | |
942 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) |
943 | |
944 | extern const struct inet_connection_sock_af_ops ipv4_specific; |
945 | |
946 | #if IS_ENABLED(CONFIG_IPV6) |
947 | /* This is the variant of inet6_iif() that must be used by TCP, |
948 | * as TCP moves IP6CB into a different location in skb->cb[] |
949 | */ |
950 | static inline int tcp_v6_iif(const struct sk_buff *skb) |
951 | { |
952 | return TCP_SKB_CB(skb)->header.h6.iif; |
953 | } |
954 | |
955 | static inline int tcp_v6_iif_l3_slave(const struct sk_buff *skb) |
956 | { |
957 | bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); |
958 | |
959 | return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; |
960 | } |
961 | |
962 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
963 | static inline int tcp_v6_sdif(const struct sk_buff *skb) |
964 | { |
965 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
966 | if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags)) |
967 | return TCP_SKB_CB(skb)->header.h6.iif; |
968 | #endif |
969 | return 0; |
970 | } |
971 | |
972 | extern const struct inet_connection_sock_af_ops ipv6_specific; |
973 | |
974 | INDIRECT_CALLABLE_DECLARE(void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)); |
975 | INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *skb)); |
976 | void tcp_v6_early_demux(struct sk_buff *skb); |
977 | |
978 | #endif |
979 | |
980 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
981 | static inline int tcp_v4_sdif(struct sk_buff *skb) |
982 | { |
983 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
984 | if (skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) |
985 | return TCP_SKB_CB(skb)->header.h4.iif; |
986 | #endif |
987 | return 0; |
988 | } |
989 | |
990 | /* Due to TSO, an SKB can be composed of multiple actual |
991 | * packets. To keep these tracked properly, we use this. |
992 | */ |
993 | static inline int tcp_skb_pcount(const struct sk_buff *skb) |
994 | { |
995 | return TCP_SKB_CB(skb)->tcp_gso_segs; |
996 | } |
997 | |
998 | static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) |
999 | { |
1000 | TCP_SKB_CB(skb)->tcp_gso_segs = segs; |
1001 | } |
1002 | |
1003 | static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) |
1004 | { |
1005 | TCP_SKB_CB(skb)->tcp_gso_segs += segs; |
1006 | } |
1007 | |
1008 | /* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ |
1009 | static inline int tcp_skb_mss(const struct sk_buff *skb) |
1010 | { |
1011 | return TCP_SKB_CB(skb)->tcp_gso_size; |
1012 | } |
1013 | |
1014 | static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) |
1015 | { |
1016 | return likely(!TCP_SKB_CB(skb)->eor); |
1017 | } |
1018 | |
1019 | static inline bool tcp_skb_can_collapse(const struct sk_buff *to, |
1020 | const struct sk_buff *from) |
1021 | { |
1022 | return likely(tcp_skb_can_collapse_to(to) && |
1023 | mptcp_skb_can_collapse(to, from) && |
1024 | skb_pure_zcopy_same(to, from)); |
1025 | } |
1026 | |
1027 | /* Events passed to congestion control interface */ |
1028 | enum tcp_ca_event { |
1029 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ |
1030 | CA_EVENT_CWND_RESTART, /* congestion window restart */ |
1031 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ |
1032 | CA_EVENT_LOSS, /* loss timeout */ |
1033 | CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ |
1034 | CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ |
1035 | }; |
1036 | |
1037 | /* Information about inbound ACK, passed to cong_ops->in_ack_event() */ |
1038 | enum tcp_ca_ack_event_flags { |
1039 | CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ |
1040 | CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ |
1041 | CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ |
1042 | }; |
1043 | |
1044 | /* |
1045 | * Interface for adding new TCP congestion control handlers |
1046 | */ |
1047 | #define TCP_CA_NAME_MAX 16 |
1048 | #define TCP_CA_MAX 128 |
1049 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) |
1050 | |
1051 | #define TCP_CA_UNSPEC 0 |
1052 | |
1053 | /* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ |
1054 | #define TCP_CONG_NON_RESTRICTED 0x1 |
1055 | /* Requires ECN/ECT set on all packets */ |
1056 | #define TCP_CONG_NEEDS_ECN 0x2 |
1057 | #define TCP_CONG_MASK (TCP_CONG_NON_RESTRICTED | TCP_CONG_NEEDS_ECN) |
1058 | |
1059 | union tcp_cc_info; |
1060 | |
1061 | struct ack_sample { |
1062 | u32 pkts_acked; |
1063 | s32 rtt_us; |
1064 | u32 in_flight; |
1065 | }; |
1066 | |
1067 | /* A rate sample measures the number of (original/retransmitted) data |
1068 | * packets delivered "delivered" over an interval of time "interval_us". |
1069 | * The tcp_rate.c code fills in the rate sample, and congestion |
1070 | * control modules that define a cong_control function to run at the end |
1071 | * of ACK processing can optionally chose to consult this sample when |
1072 | * setting cwnd and pacing rate. |
1073 | * A sample is invalid if "delivered" or "interval_us" is negative. |
1074 | */ |
1075 | struct rate_sample { |
1076 | u64 prior_mstamp; /* starting timestamp for interval */ |
1077 | u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ |
1078 | u32 prior_delivered_ce;/* tp->delivered_ce at "prior_mstamp" */ |
1079 | s32 delivered; /* number of packets delivered over interval */ |
1080 | s32 delivered_ce; /* number of packets delivered w/ CE marks*/ |
1081 | long interval_us; /* time for tp->delivered to incr "delivered" */ |
1082 | u32 snd_interval_us; /* snd interval for delivered packets */ |
1083 | u32 rcv_interval_us; /* rcv interval for delivered packets */ |
1084 | long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ |
1085 | int losses; /* number of packets marked lost upon ACK */ |
1086 | u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ |
1087 | u32 prior_in_flight; /* in flight before this ACK */ |
1088 | u32 last_end_seq; /* end_seq of most recently ACKed packet */ |
1089 | bool is_app_limited; /* is sample from packet with bubble in pipe? */ |
1090 | bool is_retrans; /* is sample from retransmission? */ |
1091 | bool is_ack_delayed; /* is this (likely) a delayed ACK? */ |
1092 | }; |
1093 | |
1094 | struct tcp_congestion_ops { |
1095 | /* fast path fields are put first to fill one cache line */ |
1096 | |
1097 | /* return slow start threshold (required) */ |
1098 | u32 (*ssthresh)(struct sock *sk); |
1099 | |
1100 | /* do new cwnd calculation (required) */ |
1101 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); |
1102 | |
1103 | /* call before changing ca_state (optional) */ |
1104 | void (*set_state)(struct sock *sk, u8 new_state); |
1105 | |
1106 | /* call when cwnd event occurs (optional) */ |
1107 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
1108 | |
1109 | /* call when ack arrives (optional) */ |
1110 | void (*in_ack_event)(struct sock *sk, u32 flags); |
1111 | |
1112 | /* hook for packet ack accounting (optional) */ |
1113 | void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); |
1114 | |
1115 | /* override sysctl_tcp_min_tso_segs */ |
1116 | u32 (*min_tso_segs)(struct sock *sk); |
1117 | |
1118 | /* call when packets are delivered to update cwnd and pacing rate, |
1119 | * after all the ca_state processing. (optional) |
1120 | */ |
1121 | void (*cong_control)(struct sock *sk, const struct rate_sample *rs); |
1122 | |
1123 | |
1124 | /* new value of cwnd after loss (required) */ |
1125 | u32 (*undo_cwnd)(struct sock *sk); |
1126 | /* returns the multiplier used in tcp_sndbuf_expand (optional) */ |
1127 | u32 (*sndbuf_expand)(struct sock *sk); |
1128 | |
1129 | /* control/slow paths put last */ |
1130 | /* get info for inet_diag (optional) */ |
1131 | size_t (*get_info)(struct sock *sk, u32 ext, int *attr, |
1132 | union tcp_cc_info *info); |
1133 | |
1134 | char name[TCP_CA_NAME_MAX]; |
1135 | struct module *owner; |
1136 | struct list_head list; |
1137 | u32 key; |
1138 | u32 flags; |
1139 | |
1140 | /* initialize private data (optional) */ |
1141 | void (*init)(struct sock *sk); |
1142 | /* cleanup private data (optional) */ |
1143 | void (*release)(struct sock *sk); |
1144 | } ____cacheline_aligned_in_smp; |
1145 | |
1146 | int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
1147 | void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); |
1148 | int tcp_update_congestion_control(struct tcp_congestion_ops *type, |
1149 | struct tcp_congestion_ops *old_type); |
1150 | int tcp_validate_congestion_control(struct tcp_congestion_ops *ca); |
1151 | |
1152 | void tcp_assign_congestion_control(struct sock *sk); |
1153 | void tcp_init_congestion_control(struct sock *sk); |
1154 | void tcp_cleanup_congestion_control(struct sock *sk); |
1155 | int tcp_set_default_congestion_control(struct net *net, const char *name); |
1156 | void tcp_get_default_congestion_control(struct net *net, char *name); |
1157 | void tcp_get_available_congestion_control(char *buf, size_t len); |
1158 | void tcp_get_allowed_congestion_control(char *buf, size_t len); |
1159 | int tcp_set_allowed_congestion_control(char *allowed); |
1160 | int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, |
1161 | bool cap_net_admin); |
1162 | u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); |
1163 | void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); |
1164 | |
1165 | u32 tcp_reno_ssthresh(struct sock *sk); |
1166 | u32 tcp_reno_undo_cwnd(struct sock *sk); |
1167 | void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); |
1168 | extern struct tcp_congestion_ops tcp_reno; |
1169 | |
1170 | struct tcp_congestion_ops *tcp_ca_find(const char *name); |
1171 | struct tcp_congestion_ops *tcp_ca_find_key(u32 key); |
1172 | u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_ca); |
1173 | #ifdef CONFIG_INET |
1174 | char *tcp_ca_get_name_by_key(u32 key, char *buffer); |
1175 | #else |
1176 | static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) |
1177 | { |
1178 | return NULL; |
1179 | } |
1180 | #endif |
1181 | |
1182 | static inline bool tcp_ca_needs_ecn(const struct sock *sk) |
1183 | { |
1184 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1185 | |
1186 | return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; |
1187 | } |
1188 | |
1189 | static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) |
1190 | { |
1191 | const struct inet_connection_sock *icsk = inet_csk(sk); |
1192 | |
1193 | if (icsk->icsk_ca_ops->cwnd_event) |
1194 | icsk->icsk_ca_ops->cwnd_event(sk, event); |
1195 | } |
1196 | |
1197 | /* From tcp_cong.c */ |
1198 | void tcp_set_ca_state(struct sock *sk, const u8 ca_state); |
1199 | |
1200 | /* From tcp_rate.c */ |
1201 | void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); |
1202 | void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, |
1203 | struct rate_sample *rs); |
1204 | void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, |
1205 | bool is_sack_reneg, struct rate_sample *rs); |
1206 | void tcp_rate_check_app_limited(struct sock *sk); |
1207 | |
1208 | static inline bool tcp_skb_sent_after(u64 t1, u64 t2, u32 seq1, u32 seq2) |
1209 | { |
1210 | return t1 > t2 || (t1 == t2 && after(seq1, seq2)); |
1211 | } |
1212 | |
1213 | /* These functions determine how the current flow behaves in respect of SACK |
1214 | * handling. SACK is negotiated with the peer, and therefore it can vary |
1215 | * between different flows. |
1216 | * |
1217 | * tcp_is_sack - SACK enabled |
1218 | * tcp_is_reno - No SACK |
1219 | */ |
1220 | static inline int tcp_is_sack(const struct tcp_sock *tp) |
1221 | { |
1222 | return likely(tp->rx_opt.sack_ok); |
1223 | } |
1224 | |
1225 | static inline bool tcp_is_reno(const struct tcp_sock *tp) |
1226 | { |
1227 | return !tcp_is_sack(tp); |
1228 | } |
1229 | |
1230 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
1231 | { |
1232 | return tp->sacked_out + tp->lost_out; |
1233 | } |
1234 | |
1235 | /* This determines how many packets are "in the network" to the best |
1236 | * of our knowledge. In many cases it is conservative, but where |
1237 | * detailed information is available from the receiver (via SACK |
1238 | * blocks etc.) we can make more aggressive calculations. |
1239 | * |
1240 | * Use this for decisions involving congestion control, use just |
1241 | * tp->packets_out to determine if the send queue is empty or not. |
1242 | * |
1243 | * Read this equation as: |
1244 | * |
1245 | * "Packets sent once on transmission queue" MINUS |
1246 | * "Packets left network, but not honestly ACKed yet" PLUS |
1247 | * "Packets fast retransmitted" |
1248 | */ |
1249 | static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
1250 | { |
1251 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
1252 | } |
1253 | |
1254 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
1255 | |
1256 | static inline u32 tcp_snd_cwnd(const struct tcp_sock *tp) |
1257 | { |
1258 | return tp->snd_cwnd; |
1259 | } |
1260 | |
1261 | static inline void tcp_snd_cwnd_set(struct tcp_sock *tp, u32 val) |
1262 | { |
1263 | WARN_ON_ONCE((int)val <= 0); |
1264 | tp->snd_cwnd = val; |
1265 | } |
1266 | |
1267 | static inline bool tcp_in_slow_start(const struct tcp_sock *tp) |
1268 | { |
1269 | return tcp_snd_cwnd(tp) < tp->snd_ssthresh; |
1270 | } |
1271 | |
1272 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) |
1273 | { |
1274 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; |
1275 | } |
1276 | |
1277 | static inline bool tcp_in_cwnd_reduction(const struct sock *sk) |
1278 | { |
1279 | return (TCPF_CA_CWR | TCPF_CA_Recovery) & |
1280 | (1 << inet_csk(sk)->icsk_ca_state); |
1281 | } |
1282 | |
1283 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
1284 | * The exception is cwnd reduction phase, when cwnd is decreasing towards |
1285 | * ssthresh. |
1286 | */ |
1287 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
1288 | { |
1289 | const struct tcp_sock *tp = tcp_sk(sk); |
1290 | |
1291 | if (tcp_in_cwnd_reduction(sk)) |
1292 | return tp->snd_ssthresh; |
1293 | else |
1294 | return max(tp->snd_ssthresh, |
1295 | ((tcp_snd_cwnd(tp) >> 1) + |
1296 | (tcp_snd_cwnd(tp) >> 2))); |
1297 | } |
1298 | |
1299 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
1300 | #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) |
1301 | |
1302 | void tcp_enter_cwr(struct sock *sk); |
1303 | __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); |
1304 | |
1305 | /* The maximum number of MSS of available cwnd for which TSO defers |
1306 | * sending if not using sysctl_tcp_tso_win_divisor. |
1307 | */ |
1308 | static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) |
1309 | { |
1310 | return 3; |
1311 | } |
1312 | |
1313 | /* Returns end sequence number of the receiver's advertised window */ |
1314 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) |
1315 | { |
1316 | return tp->snd_una + tp->snd_wnd; |
1317 | } |
1318 | |
1319 | /* We follow the spirit of RFC2861 to validate cwnd but implement a more |
1320 | * flexible approach. The RFC suggests cwnd should not be raised unless |
1321 | * it was fully used previously. And that's exactly what we do in |
1322 | * congestion avoidance mode. But in slow start we allow cwnd to grow |
1323 | * as long as the application has used half the cwnd. |
1324 | * Example : |
1325 | * cwnd is 10 (IW10), but application sends 9 frames. |
1326 | * We allow cwnd to reach 18 when all frames are ACKed. |
1327 | * This check is safe because it's as aggressive as slow start which already |
1328 | * risks 100% overshoot. The advantage is that we discourage application to |
1329 | * either send more filler packets or data to artificially blow up the cwnd |
1330 | * usage, and allow application-limited process to probe bw more aggressively. |
1331 | */ |
1332 | static inline bool tcp_is_cwnd_limited(const struct sock *sk) |
1333 | { |
1334 | const struct tcp_sock *tp = tcp_sk(sk); |
1335 | |
1336 | if (tp->is_cwnd_limited) |
1337 | return true; |
1338 | |
1339 | /* If in slow start, ensure cwnd grows to twice what was ACKed. */ |
1340 | if (tcp_in_slow_start(tp)) |
1341 | return tcp_snd_cwnd(tp) < 2 * tp->max_packets_out; |
1342 | |
1343 | return false; |
1344 | } |
1345 | |
1346 | /* BBR congestion control needs pacing. |
1347 | * Same remark for SO_MAX_PACING_RATE. |
1348 | * sch_fq packet scheduler is efficiently handling pacing, |
1349 | * but is not always installed/used. |
1350 | * Return true if TCP stack should pace packets itself. |
1351 | */ |
1352 | static inline bool tcp_needs_internal_pacing(const struct sock *sk) |
1353 | { |
1354 | return smp_load_acquire(&sk->sk_pacing_status) == SK_PACING_NEEDED; |
1355 | } |
1356 | |
1357 | /* Estimates in how many jiffies next packet for this flow can be sent. |
1358 | * Scheduling a retransmit timer too early would be silly. |
1359 | */ |
1360 | static inline unsigned long tcp_pacing_delay(const struct sock *sk) |
1361 | { |
1362 | s64 delay = tcp_sk(sk)->tcp_wstamp_ns - tcp_sk(sk)->tcp_clock_cache; |
1363 | |
1364 | return delay > 0 ? nsecs_to_jiffies(n: delay) : 0; |
1365 | } |
1366 | |
1367 | static inline void tcp_reset_xmit_timer(struct sock *sk, |
1368 | const int what, |
1369 | unsigned long when, |
1370 | const unsigned long max_when) |
1371 | { |
1372 | inet_csk_reset_xmit_timer(sk, what, when: when + tcp_pacing_delay(sk), |
1373 | max_when); |
1374 | } |
1375 | |
1376 | /* Something is really bad, we could not queue an additional packet, |
1377 | * because qdisc is full or receiver sent a 0 window, or we are paced. |
1378 | * We do not want to add fuel to the fire, or abort too early, |
1379 | * so make sure the timer we arm now is at least 200ms in the future, |
1380 | * regardless of current icsk_rto value (as it could be ~2ms) |
1381 | */ |
1382 | static inline unsigned long tcp_probe0_base(const struct sock *sk) |
1383 | { |
1384 | return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); |
1385 | } |
1386 | |
1387 | /* Variant of inet_csk_rto_backoff() used for zero window probes */ |
1388 | static inline unsigned long tcp_probe0_when(const struct sock *sk, |
1389 | unsigned long max_when) |
1390 | { |
1391 | u8 backoff = min_t(u8, ilog2(TCP_RTO_MAX / TCP_RTO_MIN) + 1, |
1392 | inet_csk(sk)->icsk_backoff); |
1393 | u64 when = (u64)tcp_probe0_base(sk) << backoff; |
1394 | |
1395 | return (unsigned long)min_t(u64, when, max_when); |
1396 | } |
1397 | |
1398 | static inline void tcp_check_probe_timer(struct sock *sk) |
1399 | { |
1400 | if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) |
1401 | tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
1402 | when: tcp_probe0_base(sk), TCP_RTO_MAX); |
1403 | } |
1404 | |
1405 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
1406 | { |
1407 | tp->snd_wl1 = seq; |
1408 | } |
1409 | |
1410 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
1411 | { |
1412 | tp->snd_wl1 = seq; |
1413 | } |
1414 | |
1415 | /* |
1416 | * Calculate(/check) TCP checksum |
1417 | */ |
1418 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
1419 | __be32 daddr, __wsum base) |
1420 | { |
1421 | return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_TCP, sum: base); |
1422 | } |
1423 | |
1424 | static inline bool tcp_checksum_complete(struct sk_buff *skb) |
1425 | { |
1426 | return !skb_csum_unnecessary(skb) && |
1427 | __skb_checksum_complete(skb); |
1428 | } |
1429 | |
1430 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb, |
1431 | enum skb_drop_reason *reason); |
1432 | |
1433 | |
1434 | int tcp_filter(struct sock *sk, struct sk_buff *skb); |
1435 | void tcp_set_state(struct sock *sk, int state); |
1436 | void tcp_done(struct sock *sk); |
1437 | int tcp_abort(struct sock *sk, int err); |
1438 | |
1439 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
1440 | { |
1441 | rx_opt->dsack = 0; |
1442 | rx_opt->num_sacks = 0; |
1443 | } |
1444 | |
1445 | void tcp_cwnd_restart(struct sock *sk, s32 delta); |
1446 | |
1447 | static inline void tcp_slow_start_after_idle_check(struct sock *sk) |
1448 | { |
1449 | const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; |
1450 | struct tcp_sock *tp = tcp_sk(sk); |
1451 | s32 delta; |
1452 | |
1453 | if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle) || |
1454 | tp->packets_out || ca_ops->cong_control) |
1455 | return; |
1456 | delta = tcp_jiffies32 - tp->lsndtime; |
1457 | if (delta > inet_csk(sk)->icsk_rto) |
1458 | tcp_cwnd_restart(sk, delta); |
1459 | } |
1460 | |
1461 | /* Determine a window scaling and initial window to offer. */ |
1462 | void tcp_select_initial_window(const struct sock *sk, int __space, |
1463 | __u32 mss, __u32 *rcv_wnd, |
1464 | __u32 *window_clamp, int wscale_ok, |
1465 | __u8 *rcv_wscale, __u32 init_rcv_wnd); |
1466 | |
1467 | static inline int __tcp_win_from_space(u8 scaling_ratio, int space) |
1468 | { |
1469 | s64 scaled_space = (s64)space * scaling_ratio; |
1470 | |
1471 | return scaled_space >> TCP_RMEM_TO_WIN_SCALE; |
1472 | } |
1473 | |
1474 | static inline int tcp_win_from_space(const struct sock *sk, int space) |
1475 | { |
1476 | return __tcp_win_from_space(tcp_sk(sk)->scaling_ratio, space); |
1477 | } |
1478 | |
1479 | /* inverse of __tcp_win_from_space() */ |
1480 | static inline int __tcp_space_from_win(u8 scaling_ratio, int win) |
1481 | { |
1482 | u64 val = (u64)win << TCP_RMEM_TO_WIN_SCALE; |
1483 | |
1484 | do_div(val, scaling_ratio); |
1485 | return val; |
1486 | } |
1487 | |
1488 | static inline int tcp_space_from_win(const struct sock *sk, int win) |
1489 | { |
1490 | return __tcp_space_from_win(tcp_sk(sk)->scaling_ratio, win); |
1491 | } |
1492 | |
1493 | /* Assume a conservative default of 1200 bytes of payload per 4K page. |
1494 | * This may be adjusted later in tcp_measure_rcv_mss(). |
1495 | */ |
1496 | #define TCP_DEFAULT_SCALING_RATIO ((1200 << TCP_RMEM_TO_WIN_SCALE) / \ |
1497 | SKB_TRUESIZE(4096)) |
1498 | |
1499 | static inline void tcp_scaling_ratio_init(struct sock *sk) |
1500 | { |
1501 | tcp_sk(sk)->scaling_ratio = TCP_DEFAULT_SCALING_RATIO; |
1502 | } |
1503 | |
1504 | /* Note: caller must be prepared to deal with negative returns */ |
1505 | static inline int tcp_space(const struct sock *sk) |
1506 | { |
1507 | return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - |
1508 | READ_ONCE(sk->sk_backlog.len) - |
1509 | atomic_read(v: &sk->sk_rmem_alloc)); |
1510 | } |
1511 | |
1512 | static inline int tcp_full_space(const struct sock *sk) |
1513 | { |
1514 | return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); |
1515 | } |
1516 | |
1517 | static inline void tcp_adjust_rcv_ssthresh(struct sock *sk) |
1518 | { |
1519 | int unused_mem = sk_unused_reserved_mem(sk); |
1520 | struct tcp_sock *tp = tcp_sk(sk); |
1521 | |
1522 | tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss); |
1523 | if (unused_mem) |
1524 | tp->rcv_ssthresh = max_t(u32, tp->rcv_ssthresh, |
1525 | tcp_win_from_space(sk, unused_mem)); |
1526 | } |
1527 | |
1528 | void tcp_cleanup_rbuf(struct sock *sk, int copied); |
1529 | void __tcp_cleanup_rbuf(struct sock *sk, int copied); |
1530 | |
1531 | |
1532 | /* We provision sk_rcvbuf around 200% of sk_rcvlowat. |
1533 | * If 87.5 % (7/8) of the space has been consumed, we want to override |
1534 | * SO_RCVLOWAT constraint, since we are receiving skbs with too small |
1535 | * len/truesize ratio. |
1536 | */ |
1537 | static inline bool tcp_rmem_pressure(const struct sock *sk) |
1538 | { |
1539 | int rcvbuf, threshold; |
1540 | |
1541 | if (tcp_under_memory_pressure(sk)) |
1542 | return true; |
1543 | |
1544 | rcvbuf = READ_ONCE(sk->sk_rcvbuf); |
1545 | threshold = rcvbuf - (rcvbuf >> 3); |
1546 | |
1547 | return atomic_read(v: &sk->sk_rmem_alloc) > threshold; |
1548 | } |
1549 | |
1550 | static inline bool tcp_epollin_ready(const struct sock *sk, int target) |
1551 | { |
1552 | const struct tcp_sock *tp = tcp_sk(sk); |
1553 | int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); |
1554 | |
1555 | if (avail <= 0) |
1556 | return false; |
1557 | |
1558 | return (avail >= target) || tcp_rmem_pressure(sk) || |
1559 | (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss); |
1560 | } |
1561 | |
1562 | extern void tcp_openreq_init_rwin(struct request_sock *req, |
1563 | const struct sock *sk_listener, |
1564 | const struct dst_entry *dst); |
1565 | |
1566 | void tcp_enter_memory_pressure(struct sock *sk); |
1567 | void tcp_leave_memory_pressure(struct sock *sk); |
1568 | |
1569 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
1570 | { |
1571 | struct net *net = sock_net(sk: (struct sock *)tp); |
1572 | int val; |
1573 | |
1574 | /* Paired with WRITE_ONCE() in tcp_sock_set_keepintvl() |
1575 | * and do_tcp_setsockopt(). |
1576 | */ |
1577 | val = READ_ONCE(tp->keepalive_intvl); |
1578 | |
1579 | return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); |
1580 | } |
1581 | |
1582 | static inline int keepalive_time_when(const struct tcp_sock *tp) |
1583 | { |
1584 | struct net *net = sock_net(sk: (struct sock *)tp); |
1585 | int val; |
1586 | |
1587 | /* Paired with WRITE_ONCE() in tcp_sock_set_keepidle_locked() */ |
1588 | val = READ_ONCE(tp->keepalive_time); |
1589 | |
1590 | return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); |
1591 | } |
1592 | |
1593 | static inline int keepalive_probes(const struct tcp_sock *tp) |
1594 | { |
1595 | struct net *net = sock_net(sk: (struct sock *)tp); |
1596 | int val; |
1597 | |
1598 | /* Paired with WRITE_ONCE() in tcp_sock_set_keepcnt() |
1599 | * and do_tcp_setsockopt(). |
1600 | */ |
1601 | val = READ_ONCE(tp->keepalive_probes); |
1602 | |
1603 | return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes); |
1604 | } |
1605 | |
1606 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
1607 | { |
1608 | const struct inet_connection_sock *icsk = &tp->inet_conn; |
1609 | |
1610 | return min_t(u32, tcp_jiffies32 - icsk->icsk_ack.lrcvtime, |
1611 | tcp_jiffies32 - tp->rcv_tstamp); |
1612 | } |
1613 | |
1614 | static inline int tcp_fin_time(const struct sock *sk) |
1615 | { |
1616 | int fin_timeout = tcp_sk(sk)->linger2 ? : |
1617 | READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fin_timeout); |
1618 | const int rto = inet_csk(sk)->icsk_rto; |
1619 | |
1620 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
1621 | fin_timeout = (rto << 2) - (rto >> 1); |
1622 | |
1623 | return fin_timeout; |
1624 | } |
1625 | |
1626 | static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, |
1627 | int paws_win) |
1628 | { |
1629 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
1630 | return true; |
1631 | if (unlikely(!time_before32(ktime_get_seconds(), |
1632 | rx_opt->ts_recent_stamp + TCP_PAWS_WRAP))) |
1633 | return true; |
1634 | /* |
1635 | * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, |
1636 | * then following tcp messages have valid values. Ignore 0 value, |
1637 | * or else 'negative' tsval might forbid us to accept their packets. |
1638 | */ |
1639 | if (!rx_opt->ts_recent) |
1640 | return true; |
1641 | return false; |
1642 | } |
1643 | |
1644 | static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, |
1645 | int rst) |
1646 | { |
1647 | if (tcp_paws_check(rx_opt, paws_win: 0)) |
1648 | return false; |
1649 | |
1650 | /* RST segments are not recommended to carry timestamp, |
1651 | and, if they do, it is recommended to ignore PAWS because |
1652 | "their cleanup function should take precedence over timestamps." |
1653 | Certainly, it is mistake. It is necessary to understand the reasons |
1654 | of this constraint to relax it: if peer reboots, clock may go |
1655 | out-of-sync and half-open connections will not be reset. |
1656 | Actually, the problem would be not existing if all |
1657 | the implementations followed draft about maintaining clock |
1658 | via reboots. Linux-2.2 DOES NOT! |
1659 | |
1660 | However, we can relax time bounds for RST segments to MSL. |
1661 | */ |
1662 | if (rst && !time_before32(ktime_get_seconds(), |
1663 | rx_opt->ts_recent_stamp + TCP_PAWS_MSL)) |
1664 | return false; |
1665 | return true; |
1666 | } |
1667 | |
1668 | bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, |
1669 | int mib_idx, u32 *last_oow_ack_time); |
1670 | |
1671 | static inline void tcp_mib_init(struct net *net) |
1672 | { |
1673 | /* See RFC 2012 */ |
1674 | TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); |
1675 | TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); |
1676 | TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); |
1677 | TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); |
1678 | } |
1679 | |
1680 | /* from STCP */ |
1681 | static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) |
1682 | { |
1683 | tp->lost_skb_hint = NULL; |
1684 | } |
1685 | |
1686 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) |
1687 | { |
1688 | tcp_clear_retrans_hints_partial(tp); |
1689 | tp->retransmit_skb_hint = NULL; |
1690 | } |
1691 | |
1692 | #define tcp_md5_addr tcp_ao_addr |
1693 | |
1694 | /* - key database */ |
1695 | struct tcp_md5sig_key { |
1696 | struct hlist_node node; |
1697 | u8 keylen; |
1698 | u8 family; /* AF_INET or AF_INET6 */ |
1699 | u8 prefixlen; |
1700 | u8 flags; |
1701 | union tcp_md5_addr addr; |
1702 | int l3index; /* set if key added with L3 scope */ |
1703 | u8 key[TCP_MD5SIG_MAXKEYLEN]; |
1704 | struct rcu_head rcu; |
1705 | }; |
1706 | |
1707 | /* - sock block */ |
1708 | struct tcp_md5sig_info { |
1709 | struct hlist_head head; |
1710 | struct rcu_head rcu; |
1711 | }; |
1712 | |
1713 | /* - pseudo header */ |
1714 | struct tcp4_pseudohdr { |
1715 | __be32 saddr; |
1716 | __be32 daddr; |
1717 | __u8 pad; |
1718 | __u8 protocol; |
1719 | __be16 len; |
1720 | }; |
1721 | |
1722 | struct tcp6_pseudohdr { |
1723 | struct in6_addr saddr; |
1724 | struct in6_addr daddr; |
1725 | __be32 len; |
1726 | __be32 protocol; /* including padding */ |
1727 | }; |
1728 | |
1729 | union tcp_md5sum_block { |
1730 | struct tcp4_pseudohdr ip4; |
1731 | #if IS_ENABLED(CONFIG_IPV6) |
1732 | struct tcp6_pseudohdr ip6; |
1733 | #endif |
1734 | }; |
1735 | |
1736 | /* |
1737 | * struct tcp_sigpool - per-CPU pool of ahash_requests |
1738 | * @scratch: per-CPU temporary area, that can be used between |
1739 | * tcp_sigpool_start() and tcp_sigpool_end() to perform |
1740 | * crypto request |
1741 | * @req: pre-allocated ahash request |
1742 | */ |
1743 | struct tcp_sigpool { |
1744 | void *scratch; |
1745 | struct ahash_request *req; |
1746 | }; |
1747 | |
1748 | int tcp_sigpool_alloc_ahash(const char *alg, size_t scratch_size); |
1749 | void tcp_sigpool_get(unsigned int id); |
1750 | void tcp_sigpool_release(unsigned int id); |
1751 | int tcp_sigpool_hash_skb_data(struct tcp_sigpool *hp, |
1752 | const struct sk_buff *skb, |
1753 | unsigned int ); |
1754 | |
1755 | /** |
1756 | * tcp_sigpool_start - disable bh and start using tcp_sigpool_ahash |
1757 | * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash() |
1758 | * @c: returned tcp_sigpool for usage (uninitialized on failure) |
1759 | * |
1760 | * Returns 0 on success, error otherwise. |
1761 | */ |
1762 | int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c); |
1763 | /** |
1764 | * tcp_sigpool_end - enable bh and stop using tcp_sigpool |
1765 | * @c: tcp_sigpool context that was returned by tcp_sigpool_start() |
1766 | */ |
1767 | void tcp_sigpool_end(struct tcp_sigpool *c); |
1768 | size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len); |
1769 | /* - functions */ |
1770 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
1771 | const struct sock *sk, const struct sk_buff *skb); |
1772 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
1773 | int family, u8 prefixlen, int l3index, u8 flags, |
1774 | const u8 *newkey, u8 newkeylen); |
1775 | int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr, |
1776 | int family, u8 prefixlen, int l3index, |
1777 | struct tcp_md5sig_key *key); |
1778 | |
1779 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, |
1780 | int family, u8 prefixlen, int l3index, u8 flags); |
1781 | void tcp_clear_md5_list(struct sock *sk); |
1782 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
1783 | const struct sock *addr_sk); |
1784 | |
1785 | #ifdef CONFIG_TCP_MD5SIG |
1786 | #include <linux/jump_label.h> |
1787 | extern struct static_key_false_deferred tcp_md5_needed; |
1788 | struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, |
1789 | const union tcp_md5_addr *addr, |
1790 | int family, bool any_l3index); |
1791 | static inline struct tcp_md5sig_key * |
1792 | tcp_md5_do_lookup(const struct sock *sk, int l3index, |
1793 | const union tcp_md5_addr *addr, int family) |
1794 | { |
1795 | if (!static_branch_unlikely(&tcp_md5_needed.key)) |
1796 | return NULL; |
1797 | return __tcp_md5_do_lookup(sk, l3index, addr, family, any_l3index: false); |
1798 | } |
1799 | |
1800 | static inline struct tcp_md5sig_key * |
1801 | tcp_md5_do_lookup_any_l3index(const struct sock *sk, |
1802 | const union tcp_md5_addr *addr, int family) |
1803 | { |
1804 | if (!static_branch_unlikely(&tcp_md5_needed.key)) |
1805 | return NULL; |
1806 | return __tcp_md5_do_lookup(sk, l3index: 0, addr, family, any_l3index: true); |
1807 | } |
1808 | |
1809 | enum skb_drop_reason |
1810 | tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, |
1811 | const void *saddr, const void *daddr, |
1812 | int family, int l3index, const __u8 *hash_location); |
1813 | |
1814 | |
1815 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) |
1816 | #else |
1817 | static inline struct tcp_md5sig_key * |
1818 | tcp_md5_do_lookup(const struct sock *sk, int l3index, |
1819 | const union tcp_md5_addr *addr, int family) |
1820 | { |
1821 | return NULL; |
1822 | } |
1823 | |
1824 | static inline struct tcp_md5sig_key * |
1825 | tcp_md5_do_lookup_any_l3index(const struct sock *sk, |
1826 | const union tcp_md5_addr *addr, int family) |
1827 | { |
1828 | return NULL; |
1829 | } |
1830 | |
1831 | static inline enum skb_drop_reason |
1832 | tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, |
1833 | const void *saddr, const void *daddr, |
1834 | int family, int l3index, const __u8 *hash_location) |
1835 | { |
1836 | return SKB_NOT_DROPPED_YET; |
1837 | } |
1838 | #define tcp_twsk_md5_key(twsk) NULL |
1839 | #endif |
1840 | |
1841 | int tcp_md5_alloc_sigpool(void); |
1842 | void tcp_md5_release_sigpool(void); |
1843 | void tcp_md5_add_sigpool(void); |
1844 | extern int tcp_md5_sigpool_id; |
1845 | |
1846 | int tcp_md5_hash_key(struct tcp_sigpool *hp, |
1847 | const struct tcp_md5sig_key *key); |
1848 | |
1849 | /* From tcp_fastopen.c */ |
1850 | void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
1851 | struct tcp_fastopen_cookie *cookie); |
1852 | void tcp_fastopen_cache_set(struct sock *sk, u16 mss, |
1853 | struct tcp_fastopen_cookie *cookie, bool syn_lost, |
1854 | u16 try_exp); |
1855 | struct tcp_fastopen_request { |
1856 | /* Fast Open cookie. Size 0 means a cookie request */ |
1857 | struct tcp_fastopen_cookie cookie; |
1858 | struct msghdr *data; /* data in MSG_FASTOPEN */ |
1859 | size_t size; |
1860 | int copied; /* queued in tcp_connect() */ |
1861 | struct ubuf_info *uarg; |
1862 | }; |
1863 | void tcp_free_fastopen_req(struct tcp_sock *tp); |
1864 | void tcp_fastopen_destroy_cipher(struct sock *sk); |
1865 | void tcp_fastopen_ctx_destroy(struct net *net); |
1866 | int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, |
1867 | void *primary_key, void *backup_key); |
1868 | int tcp_fastopen_get_cipher(struct net *net, struct inet_connection_sock *icsk, |
1869 | u64 *key); |
1870 | void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); |
1871 | struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, |
1872 | struct request_sock *req, |
1873 | struct tcp_fastopen_cookie *foc, |
1874 | const struct dst_entry *dst); |
1875 | void tcp_fastopen_init_key_once(struct net *net); |
1876 | bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, |
1877 | struct tcp_fastopen_cookie *cookie); |
1878 | bool tcp_fastopen_defer_connect(struct sock *sk, int *err); |
1879 | #define TCP_FASTOPEN_KEY_LENGTH sizeof(siphash_key_t) |
1880 | #define TCP_FASTOPEN_KEY_MAX 2 |
1881 | #define TCP_FASTOPEN_KEY_BUF_LENGTH \ |
1882 | (TCP_FASTOPEN_KEY_LENGTH * TCP_FASTOPEN_KEY_MAX) |
1883 | |
1884 | /* Fastopen key context */ |
1885 | struct tcp_fastopen_context { |
1886 | siphash_key_t key[TCP_FASTOPEN_KEY_MAX]; |
1887 | int num; |
1888 | struct rcu_head rcu; |
1889 | }; |
1890 | |
1891 | void tcp_fastopen_active_disable(struct sock *sk); |
1892 | bool tcp_fastopen_active_should_disable(struct sock *sk); |
1893 | void tcp_fastopen_active_disable_ofo_check(struct sock *sk); |
1894 | void tcp_fastopen_active_detect_blackhole(struct sock *sk, bool expired); |
1895 | |
1896 | /* Caller needs to wrap with rcu_read_(un)lock() */ |
1897 | static inline |
1898 | struct tcp_fastopen_context *tcp_fastopen_get_ctx(const struct sock *sk) |
1899 | { |
1900 | struct tcp_fastopen_context *ctx; |
1901 | |
1902 | ctx = rcu_dereference(inet_csk(sk)->icsk_accept_queue.fastopenq.ctx); |
1903 | if (!ctx) |
1904 | ctx = rcu_dereference(sock_net(sk)->ipv4.tcp_fastopen_ctx); |
1905 | return ctx; |
1906 | } |
1907 | |
1908 | static inline |
1909 | bool tcp_fastopen_cookie_match(const struct tcp_fastopen_cookie *foc, |
1910 | const struct tcp_fastopen_cookie *orig) |
1911 | { |
1912 | if (orig->len == TCP_FASTOPEN_COOKIE_SIZE && |
1913 | orig->len == foc->len && |
1914 | !memcmp(p: orig->val, q: foc->val, size: foc->len)) |
1915 | return true; |
1916 | return false; |
1917 | } |
1918 | |
1919 | static inline |
1920 | int tcp_fastopen_context_len(const struct tcp_fastopen_context *ctx) |
1921 | { |
1922 | return ctx->num; |
1923 | } |
1924 | |
1925 | /* Latencies incurred by various limits for a sender. They are |
1926 | * chronograph-like stats that are mutually exclusive. |
1927 | */ |
1928 | enum tcp_chrono { |
1929 | TCP_CHRONO_UNSPEC, |
1930 | TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ |
1931 | TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ |
1932 | TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ |
1933 | __TCP_CHRONO_MAX, |
1934 | }; |
1935 | |
1936 | void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); |
1937 | void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); |
1938 | |
1939 | /* This helper is needed, because skb->tcp_tsorted_anchor uses |
1940 | * the same memory storage than skb->destructor/_skb_refdst |
1941 | */ |
1942 | static inline void tcp_skb_tsorted_anchor_cleanup(struct sk_buff *skb) |
1943 | { |
1944 | skb->destructor = NULL; |
1945 | skb->_skb_refdst = 0UL; |
1946 | } |
1947 | |
1948 | #define tcp_skb_tsorted_save(skb) { \ |
1949 | unsigned long _save = skb->_skb_refdst; \ |
1950 | skb->_skb_refdst = 0UL; |
1951 | |
1952 | #define tcp_skb_tsorted_restore(skb) \ |
1953 | skb->_skb_refdst = _save; \ |
1954 | } |
1955 | |
1956 | void tcp_write_queue_purge(struct sock *sk); |
1957 | |
1958 | static inline struct sk_buff *tcp_rtx_queue_head(const struct sock *sk) |
1959 | { |
1960 | return skb_rb_first(&sk->tcp_rtx_queue); |
1961 | } |
1962 | |
1963 | static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) |
1964 | { |
1965 | return skb_rb_last(&sk->tcp_rtx_queue); |
1966 | } |
1967 | |
1968 | static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) |
1969 | { |
1970 | return skb_peek_tail(list_: &sk->sk_write_queue); |
1971 | } |
1972 | |
1973 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
1974 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
1975 | |
1976 | static inline struct sk_buff *tcp_send_head(const struct sock *sk) |
1977 | { |
1978 | return skb_peek(list_: &sk->sk_write_queue); |
1979 | } |
1980 | |
1981 | static inline bool tcp_skb_is_last(const struct sock *sk, |
1982 | const struct sk_buff *skb) |
1983 | { |
1984 | return skb_queue_is_last(list: &sk->sk_write_queue, skb); |
1985 | } |
1986 | |
1987 | /** |
1988 | * tcp_write_queue_empty - test if any payload (or FIN) is available in write queue |
1989 | * @sk: socket |
1990 | * |
1991 | * Since the write queue can have a temporary empty skb in it, |
1992 | * we must not use "return skb_queue_empty(&sk->sk_write_queue)" |
1993 | */ |
1994 | static inline bool tcp_write_queue_empty(const struct sock *sk) |
1995 | { |
1996 | const struct tcp_sock *tp = tcp_sk(sk); |
1997 | |
1998 | return tp->write_seq == tp->snd_nxt; |
1999 | } |
2000 | |
2001 | static inline bool tcp_rtx_queue_empty(const struct sock *sk) |
2002 | { |
2003 | return RB_EMPTY_ROOT(&sk->tcp_rtx_queue); |
2004 | } |
2005 | |
2006 | static inline bool tcp_rtx_and_write_queues_empty(const struct sock *sk) |
2007 | { |
2008 | return tcp_rtx_queue_empty(sk) && tcp_write_queue_empty(sk); |
2009 | } |
2010 | |
2011 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) |
2012 | { |
2013 | __skb_queue_tail(list: &sk->sk_write_queue, newsk: skb); |
2014 | |
2015 | /* Queue it, remembering where we must start sending. */ |
2016 | if (sk->sk_write_queue.next == skb) |
2017 | tcp_chrono_start(sk, type: TCP_CHRONO_BUSY); |
2018 | } |
2019 | |
2020 | /* Insert new before skb on the write queue of sk. */ |
2021 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
2022 | struct sk_buff *skb, |
2023 | struct sock *sk) |
2024 | { |
2025 | __skb_queue_before(list: &sk->sk_write_queue, next: skb, newsk: new); |
2026 | } |
2027 | |
2028 | static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) |
2029 | { |
2030 | tcp_skb_tsorted_anchor_cleanup(skb); |
2031 | __skb_unlink(skb, list: &sk->sk_write_queue); |
2032 | } |
2033 | |
2034 | void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb); |
2035 | |
2036 | static inline void tcp_rtx_queue_unlink(struct sk_buff *skb, struct sock *sk) |
2037 | { |
2038 | tcp_skb_tsorted_anchor_cleanup(skb); |
2039 | rb_erase(&skb->rbnode, &sk->tcp_rtx_queue); |
2040 | } |
2041 | |
2042 | static inline void tcp_rtx_queue_unlink_and_free(struct sk_buff *skb, struct sock *sk) |
2043 | { |
2044 | list_del(entry: &skb->tcp_tsorted_anchor); |
2045 | tcp_rtx_queue_unlink(skb, sk); |
2046 | tcp_wmem_free_skb(sk, skb); |
2047 | } |
2048 | |
2049 | static inline void tcp_push_pending_frames(struct sock *sk) |
2050 | { |
2051 | if (tcp_send_head(sk)) { |
2052 | struct tcp_sock *tp = tcp_sk(sk); |
2053 | |
2054 | __tcp_push_pending_frames(sk, cur_mss: tcp_current_mss(sk), nonagle: tp->nonagle); |
2055 | } |
2056 | } |
2057 | |
2058 | /* Start sequence of the skb just after the highest skb with SACKed |
2059 | * bit, valid only if sacked_out > 0 or when the caller has ensured |
2060 | * validity by itself. |
2061 | */ |
2062 | static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) |
2063 | { |
2064 | if (!tp->sacked_out) |
2065 | return tp->snd_una; |
2066 | |
2067 | if (tp->highest_sack == NULL) |
2068 | return tp->snd_nxt; |
2069 | |
2070 | return TCP_SKB_CB(tp->highest_sack)->seq; |
2071 | } |
2072 | |
2073 | static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) |
2074 | { |
2075 | tcp_sk(sk)->highest_sack = skb_rb_next(skb); |
2076 | } |
2077 | |
2078 | static inline struct sk_buff *tcp_highest_sack(struct sock *sk) |
2079 | { |
2080 | return tcp_sk(sk)->highest_sack; |
2081 | } |
2082 | |
2083 | static inline void tcp_highest_sack_reset(struct sock *sk) |
2084 | { |
2085 | tcp_sk(sk)->highest_sack = tcp_rtx_queue_head(sk); |
2086 | } |
2087 | |
2088 | /* Called when old skb is about to be deleted and replaced by new skb */ |
2089 | static inline void tcp_highest_sack_replace(struct sock *sk, |
2090 | struct sk_buff *old, |
2091 | struct sk_buff *new) |
2092 | { |
2093 | if (old == tcp_highest_sack(sk)) |
2094 | tcp_sk(sk)->highest_sack = new; |
2095 | } |
2096 | |
2097 | /* This helper checks if socket has IP_TRANSPARENT set */ |
2098 | static inline bool inet_sk_transparent(const struct sock *sk) |
2099 | { |
2100 | switch (sk->sk_state) { |
2101 | case TCP_TIME_WAIT: |
2102 | return inet_twsk(sk)->tw_transparent; |
2103 | case TCP_NEW_SYN_RECV: |
2104 | return inet_rsk(sk: inet_reqsk(sk))->no_srccheck; |
2105 | } |
2106 | return inet_test_bit(TRANSPARENT, sk); |
2107 | } |
2108 | |
2109 | /* Determines whether this is a thin stream (which may suffer from |
2110 | * increased latency). Used to trigger latency-reducing mechanisms. |
2111 | */ |
2112 | static inline bool tcp_stream_is_thin(struct tcp_sock *tp) |
2113 | { |
2114 | return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); |
2115 | } |
2116 | |
2117 | /* /proc */ |
2118 | enum tcp_seq_states { |
2119 | TCP_SEQ_STATE_LISTENING, |
2120 | TCP_SEQ_STATE_ESTABLISHED, |
2121 | }; |
2122 | |
2123 | void *tcp_seq_start(struct seq_file *seq, loff_t *pos); |
2124 | void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos); |
2125 | void tcp_seq_stop(struct seq_file *seq, void *v); |
2126 | |
2127 | struct tcp_seq_afinfo { |
2128 | sa_family_t family; |
2129 | }; |
2130 | |
2131 | struct tcp_iter_state { |
2132 | struct seq_net_private p; |
2133 | enum tcp_seq_states state; |
2134 | struct sock *syn_wait_sk; |
2135 | int bucket, offset, sbucket, num; |
2136 | loff_t last_pos; |
2137 | }; |
2138 | |
2139 | extern struct request_sock_ops tcp_request_sock_ops; |
2140 | extern struct request_sock_ops tcp6_request_sock_ops; |
2141 | |
2142 | void tcp_v4_destroy_sock(struct sock *sk); |
2143 | |
2144 | struct sk_buff *tcp_gso_segment(struct sk_buff *skb, |
2145 | netdev_features_t features); |
2146 | struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb); |
2147 | INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *skb, int thoff)); |
2148 | INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)); |
2149 | INDIRECT_CALLABLE_DECLARE(int tcp6_gro_complete(struct sk_buff *skb, int thoff)); |
2150 | INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)); |
2151 | #ifdef CONFIG_INET |
2152 | void tcp_gro_complete(struct sk_buff *skb); |
2153 | #else |
2154 | static inline void tcp_gro_complete(struct sk_buff *skb) { } |
2155 | #endif |
2156 | |
2157 | void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); |
2158 | |
2159 | static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) |
2160 | { |
2161 | struct net *net = sock_net(sk: (struct sock *)tp); |
2162 | u32 val; |
2163 | |
2164 | val = READ_ONCE(tp->notsent_lowat); |
2165 | |
2166 | return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); |
2167 | } |
2168 | |
2169 | bool tcp_stream_memory_free(const struct sock *sk, int wake); |
2170 | |
2171 | #ifdef CONFIG_PROC_FS |
2172 | int tcp4_proc_init(void); |
2173 | void tcp4_proc_exit(void); |
2174 | #endif |
2175 | |
2176 | int tcp_rtx_synack(const struct sock *sk, struct request_sock *req); |
2177 | int tcp_conn_request(struct request_sock_ops *rsk_ops, |
2178 | const struct tcp_request_sock_ops *af_ops, |
2179 | struct sock *sk, struct sk_buff *skb); |
2180 | |
2181 | /* TCP af-specific functions */ |
2182 | struct tcp_sock_af_ops { |
2183 | #ifdef CONFIG_TCP_MD5SIG |
2184 | struct tcp_md5sig_key *(*md5_lookup) (const struct sock *sk, |
2185 | const struct sock *addr_sk); |
2186 | int (*calc_md5_hash)(char *location, |
2187 | const struct tcp_md5sig_key *md5, |
2188 | const struct sock *sk, |
2189 | const struct sk_buff *skb); |
2190 | int (*md5_parse)(struct sock *sk, |
2191 | int optname, |
2192 | sockptr_t optval, |
2193 | int optlen); |
2194 | #endif |
2195 | #ifdef CONFIG_TCP_AO |
2196 | int (*ao_parse)(struct sock *sk, int optname, sockptr_t optval, int optlen); |
2197 | struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, |
2198 | struct sock *addr_sk, |
2199 | int sndid, int rcvid); |
2200 | int (*ao_calc_key_sk)(struct tcp_ao_key *mkt, u8 *key, |
2201 | const struct sock *sk, |
2202 | __be32 sisn, __be32 disn, bool send); |
2203 | int (*calc_ao_hash)(char *location, struct tcp_ao_key *ao, |
2204 | const struct sock *sk, const struct sk_buff *skb, |
2205 | const u8 *tkey, int hash_offset, u32 sne); |
2206 | #endif |
2207 | }; |
2208 | |
2209 | struct tcp_request_sock_ops { |
2210 | u16 mss_clamp; |
2211 | #ifdef CONFIG_TCP_MD5SIG |
2212 | struct tcp_md5sig_key *(*req_md5_lookup)(const struct sock *sk, |
2213 | const struct sock *addr_sk); |
2214 | int (*calc_md5_hash) (char *location, |
2215 | const struct tcp_md5sig_key *md5, |
2216 | const struct sock *sk, |
2217 | const struct sk_buff *skb); |
2218 | #endif |
2219 | #ifdef CONFIG_TCP_AO |
2220 | struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, |
2221 | struct request_sock *req, |
2222 | int sndid, int rcvid); |
2223 | int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk); |
2224 | int (*ao_synack_hash)(char *ao_hash, struct tcp_ao_key *mkt, |
2225 | struct request_sock *req, const struct sk_buff *skb, |
2226 | int hash_offset, u32 sne); |
2227 | #endif |
2228 | #ifdef CONFIG_SYN_COOKIES |
2229 | __u32 (*cookie_init_seq)(const struct sk_buff *skb, |
2230 | __u16 *mss); |
2231 | #endif |
2232 | struct dst_entry *(*route_req)(const struct sock *sk, |
2233 | struct sk_buff *skb, |
2234 | struct flowi *fl, |
2235 | struct request_sock *req); |
2236 | u32 (*init_seq)(const struct sk_buff *skb); |
2237 | u32 (*init_ts_off)(const struct net *net, const struct sk_buff *skb); |
2238 | int (*send_synack)(const struct sock *sk, struct dst_entry *dst, |
2239 | struct flowi *fl, struct request_sock *req, |
2240 | struct tcp_fastopen_cookie *foc, |
2241 | enum tcp_synack_type synack_type, |
2242 | struct sk_buff *syn_skb); |
2243 | }; |
2244 | |
2245 | extern const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops; |
2246 | #if IS_ENABLED(CONFIG_IPV6) |
2247 | extern const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops; |
2248 | #endif |
2249 | |
2250 | #ifdef CONFIG_SYN_COOKIES |
2251 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, |
2252 | const struct sock *sk, struct sk_buff *skb, |
2253 | __u16 *mss) |
2254 | { |
2255 | tcp_synq_overflow(sk); |
2256 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); |
2257 | return ops->cookie_init_seq(skb, mss); |
2258 | } |
2259 | #else |
2260 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, |
2261 | const struct sock *sk, struct sk_buff *skb, |
2262 | __u16 *mss) |
2263 | { |
2264 | return 0; |
2265 | } |
2266 | #endif |
2267 | |
2268 | struct tcp_key { |
2269 | union { |
2270 | struct { |
2271 | struct tcp_ao_key *ao_key; |
2272 | char *traffic_key; |
2273 | u32 sne; |
2274 | u8 rcv_next; |
2275 | }; |
2276 | struct tcp_md5sig_key *md5_key; |
2277 | }; |
2278 | enum { |
2279 | TCP_KEY_NONE = 0, |
2280 | TCP_KEY_MD5, |
2281 | TCP_KEY_AO, |
2282 | } type; |
2283 | }; |
2284 | |
2285 | static inline void tcp_get_current_key(const struct sock *sk, |
2286 | struct tcp_key *out) |
2287 | { |
2288 | #if defined(CONFIG_TCP_AO) || defined(CONFIG_TCP_MD5SIG) |
2289 | const struct tcp_sock *tp = tcp_sk(sk); |
2290 | #endif |
2291 | |
2292 | #ifdef CONFIG_TCP_AO |
2293 | if (static_branch_unlikely(&tcp_ao_needed.key)) { |
2294 | struct tcp_ao_info *ao; |
2295 | |
2296 | ao = rcu_dereference_protected(tp->ao_info, |
2297 | lockdep_sock_is_held(sk)); |
2298 | if (ao) { |
2299 | out->ao_key = READ_ONCE(ao->current_key); |
2300 | out->type = TCP_KEY_AO; |
2301 | return; |
2302 | } |
2303 | } |
2304 | #endif |
2305 | #ifdef CONFIG_TCP_MD5SIG |
2306 | if (static_branch_unlikely(&tcp_md5_needed.key) && |
2307 | rcu_access_pointer(tp->md5sig_info)) { |
2308 | out->md5_key = tp->af_specific->md5_lookup(sk, sk); |
2309 | if (out->md5_key) { |
2310 | out->type = TCP_KEY_MD5; |
2311 | return; |
2312 | } |
2313 | } |
2314 | #endif |
2315 | out->type = TCP_KEY_NONE; |
2316 | } |
2317 | |
2318 | static inline bool tcp_key_is_md5(const struct tcp_key *key) |
2319 | { |
2320 | #ifdef CONFIG_TCP_MD5SIG |
2321 | if (static_branch_unlikely(&tcp_md5_needed.key) && |
2322 | key->type == TCP_KEY_MD5) |
2323 | return true; |
2324 | #endif |
2325 | return false; |
2326 | } |
2327 | |
2328 | static inline bool tcp_key_is_ao(const struct tcp_key *key) |
2329 | { |
2330 | #ifdef CONFIG_TCP_AO |
2331 | if (static_branch_unlikely(&tcp_ao_needed.key) && |
2332 | key->type == TCP_KEY_AO) |
2333 | return true; |
2334 | #endif |
2335 | return false; |
2336 | } |
2337 | |
2338 | int tcpv4_offload_init(void); |
2339 | |
2340 | void tcp_v4_init(void); |
2341 | void tcp_init(void); |
2342 | |
2343 | /* tcp_recovery.c */ |
2344 | void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb); |
2345 | void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced); |
2346 | extern s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, |
2347 | u32 reo_wnd); |
2348 | extern bool tcp_rack_mark_lost(struct sock *sk); |
2349 | extern void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, |
2350 | u64 xmit_time); |
2351 | extern void tcp_rack_reo_timeout(struct sock *sk); |
2352 | extern void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs); |
2353 | |
2354 | /* tcp_plb.c */ |
2355 | |
2356 | /* |
2357 | * Scaling factor for fractions in PLB. For example, tcp_plb_update_state |
2358 | * expects cong_ratio which represents fraction of traffic that experienced |
2359 | * congestion over a single RTT. In order to avoid floating point operations, |
2360 | * this fraction should be mapped to (1 << TCP_PLB_SCALE) and passed in. |
2361 | */ |
2362 | #define TCP_PLB_SCALE 8 |
2363 | |
2364 | /* State for PLB (Protective Load Balancing) for a single TCP connection. */ |
2365 | struct tcp_plb_state { |
2366 | u8 consec_cong_rounds:5, /* consecutive congested rounds */ |
2367 | unused:3; |
2368 | u32 pause_until; /* jiffies32 when PLB can resume rerouting */ |
2369 | }; |
2370 | |
2371 | static inline void tcp_plb_init(const struct sock *sk, |
2372 | struct tcp_plb_state *plb) |
2373 | { |
2374 | plb->consec_cong_rounds = 0; |
2375 | plb->pause_until = 0; |
2376 | } |
2377 | void tcp_plb_update_state(const struct sock *sk, struct tcp_plb_state *plb, |
2378 | const int cong_ratio); |
2379 | void tcp_plb_check_rehash(struct sock *sk, struct tcp_plb_state *plb); |
2380 | void tcp_plb_update_state_upon_rto(struct sock *sk, struct tcp_plb_state *plb); |
2381 | |
2382 | /* At how many usecs into the future should the RTO fire? */ |
2383 | static inline s64 tcp_rto_delta_us(const struct sock *sk) |
2384 | { |
2385 | const struct sk_buff *skb = tcp_rtx_queue_head(sk); |
2386 | u32 rto = inet_csk(sk)->icsk_rto; |
2387 | u64 rto_time_stamp_us = tcp_skb_timestamp_us(skb) + jiffies_to_usecs(j: rto); |
2388 | |
2389 | return rto_time_stamp_us - tcp_sk(sk)->tcp_mstamp; |
2390 | } |
2391 | |
2392 | /* |
2393 | * Save and compile IPv4 options, return a pointer to it |
2394 | */ |
2395 | static inline struct ip_options_rcu *tcp_v4_save_options(struct net *net, |
2396 | struct sk_buff *skb) |
2397 | { |
2398 | const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; |
2399 | struct ip_options_rcu *dopt = NULL; |
2400 | |
2401 | if (opt->optlen) { |
2402 | int opt_size = sizeof(*dopt) + opt->optlen; |
2403 | |
2404 | dopt = kmalloc(size: opt_size, GFP_ATOMIC); |
2405 | if (dopt && __ip_options_echo(net, dopt: &dopt->opt, skb, sopt: opt)) { |
2406 | kfree(objp: dopt); |
2407 | dopt = NULL; |
2408 | } |
2409 | } |
2410 | return dopt; |
2411 | } |
2412 | |
2413 | /* locally generated TCP pure ACKs have skb->truesize == 2 |
2414 | * (check tcp_send_ack() in net/ipv4/tcp_output.c ) |
2415 | * This is much faster than dissecting the packet to find out. |
2416 | * (Think of GRE encapsulations, IPv4, IPv6, ...) |
2417 | */ |
2418 | static inline bool skb_is_tcp_pure_ack(const struct sk_buff *skb) |
2419 | { |
2420 | return skb->truesize == 2; |
2421 | } |
2422 | |
2423 | static inline void skb_set_tcp_pure_ack(struct sk_buff *skb) |
2424 | { |
2425 | skb->truesize = 2; |
2426 | } |
2427 | |
2428 | static inline int tcp_inq(struct sock *sk) |
2429 | { |
2430 | struct tcp_sock *tp = tcp_sk(sk); |
2431 | int answ; |
2432 | |
2433 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { |
2434 | answ = 0; |
2435 | } else if (sock_flag(sk, flag: SOCK_URGINLINE) || |
2436 | !tp->urg_data || |
2437 | before(seq1: tp->urg_seq, seq2: tp->copied_seq) || |
2438 | !before(seq1: tp->urg_seq, seq2: tp->rcv_nxt)) { |
2439 | |
2440 | answ = tp->rcv_nxt - tp->copied_seq; |
2441 | |
2442 | /* Subtract 1, if FIN was received */ |
2443 | if (answ && sock_flag(sk, flag: SOCK_DONE)) |
2444 | answ--; |
2445 | } else { |
2446 | answ = tp->urg_seq - tp->copied_seq; |
2447 | } |
2448 | |
2449 | return answ; |
2450 | } |
2451 | |
2452 | int tcp_peek_len(struct socket *sock); |
2453 | |
2454 | static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) |
2455 | { |
2456 | u16 segs_in; |
2457 | |
2458 | segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); |
2459 | |
2460 | /* We update these fields while other threads might |
2461 | * read them from tcp_get_info() |
2462 | */ |
2463 | WRITE_ONCE(tp->segs_in, tp->segs_in + segs_in); |
2464 | if (skb->len > tcp_hdrlen(skb)) |
2465 | WRITE_ONCE(tp->data_segs_in, tp->data_segs_in + segs_in); |
2466 | } |
2467 | |
2468 | /* |
2469 | * TCP listen path runs lockless. |
2470 | * We forced "struct sock" to be const qualified to make sure |
2471 | * we don't modify one of its field by mistake. |
2472 | * Here, we increment sk_drops which is an atomic_t, so we can safely |
2473 | * make sock writable again. |
2474 | */ |
2475 | static inline void tcp_listendrop(const struct sock *sk) |
2476 | { |
2477 | atomic_inc(v: &((struct sock *)sk)->sk_drops); |
2478 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); |
2479 | } |
2480 | |
2481 | enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer); |
2482 | |
2483 | /* |
2484 | * Interface for adding Upper Level Protocols over TCP |
2485 | */ |
2486 | |
2487 | #define TCP_ULP_NAME_MAX 16 |
2488 | #define TCP_ULP_MAX 128 |
2489 | #define TCP_ULP_BUF_MAX (TCP_ULP_NAME_MAX*TCP_ULP_MAX) |
2490 | |
2491 | struct tcp_ulp_ops { |
2492 | struct list_head list; |
2493 | |
2494 | /* initialize ulp */ |
2495 | int (*init)(struct sock *sk); |
2496 | /* update ulp */ |
2497 | void (*update)(struct sock *sk, struct proto *p, |
2498 | void (*write_space)(struct sock *sk)); |
2499 | /* cleanup ulp */ |
2500 | void (*release)(struct sock *sk); |
2501 | /* diagnostic */ |
2502 | int (*get_info)(const struct sock *sk, struct sk_buff *skb); |
2503 | size_t (*get_info_size)(const struct sock *sk); |
2504 | /* clone ulp */ |
2505 | void (*clone)(const struct request_sock *req, struct sock *newsk, |
2506 | const gfp_t priority); |
2507 | |
2508 | char name[TCP_ULP_NAME_MAX]; |
2509 | struct module *owner; |
2510 | }; |
2511 | int tcp_register_ulp(struct tcp_ulp_ops *type); |
2512 | void tcp_unregister_ulp(struct tcp_ulp_ops *type); |
2513 | int tcp_set_ulp(struct sock *sk, const char *name); |
2514 | void tcp_get_available_ulp(char *buf, size_t len); |
2515 | void tcp_cleanup_ulp(struct sock *sk); |
2516 | void tcp_update_ulp(struct sock *sk, struct proto *p, |
2517 | void (*write_space)(struct sock *sk)); |
2518 | |
2519 | #define MODULE_ALIAS_TCP_ULP(name) \ |
2520 | __MODULE_INFO(alias, alias_userspace, name); \ |
2521 | __MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name) |
2522 | |
2523 | #ifdef CONFIG_NET_SOCK_MSG |
2524 | struct sk_msg; |
2525 | struct sk_psock; |
2526 | |
2527 | #ifdef CONFIG_BPF_SYSCALL |
2528 | int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore); |
2529 | void tcp_bpf_clone(const struct sock *sk, struct sock *newsk); |
2530 | #endif /* CONFIG_BPF_SYSCALL */ |
2531 | |
2532 | #ifdef CONFIG_INET |
2533 | void tcp_eat_skb(struct sock *sk, struct sk_buff *skb); |
2534 | #else |
2535 | static inline void tcp_eat_skb(struct sock *sk, struct sk_buff *skb) |
2536 | { |
2537 | } |
2538 | #endif |
2539 | |
2540 | int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress, |
2541 | struct sk_msg *msg, u32 bytes, int flags); |
2542 | #endif /* CONFIG_NET_SOCK_MSG */ |
2543 | |
2544 | #if !defined(CONFIG_BPF_SYSCALL) || !defined(CONFIG_NET_SOCK_MSG) |
2545 | static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk) |
2546 | { |
2547 | } |
2548 | #endif |
2549 | |
2550 | #ifdef CONFIG_CGROUP_BPF |
2551 | static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, |
2552 | struct sk_buff *skb, |
2553 | unsigned int end_offset) |
2554 | { |
2555 | skops->skb = skb; |
2556 | skops->skb_data_end = skb->data + end_offset; |
2557 | } |
2558 | #else |
2559 | static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, |
2560 | struct sk_buff *skb, |
2561 | unsigned int end_offset) |
2562 | { |
2563 | } |
2564 | #endif |
2565 | |
2566 | /* Call BPF_SOCK_OPS program that returns an int. If the return value |
2567 | * is < 0, then the BPF op failed (for example if the loaded BPF |
2568 | * program does not support the chosen operation or there is no BPF |
2569 | * program loaded). |
2570 | */ |
2571 | #ifdef CONFIG_BPF |
2572 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
2573 | { |
2574 | struct bpf_sock_ops_kern sock_ops; |
2575 | int ret; |
2576 | |
2577 | memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); |
2578 | if (sk_fullsock(sk)) { |
2579 | sock_ops.is_fullsock = 1; |
2580 | sock_owned_by_me(sk); |
2581 | } |
2582 | |
2583 | sock_ops.sk = sk; |
2584 | sock_ops.op = op; |
2585 | if (nargs > 0) |
2586 | memcpy(sock_ops.args, args, nargs * sizeof(*args)); |
2587 | |
2588 | ret = BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); |
2589 | if (ret == 0) |
2590 | ret = sock_ops.reply; |
2591 | else |
2592 | ret = -1; |
2593 | return ret; |
2594 | } |
2595 | |
2596 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) |
2597 | { |
2598 | u32 args[2] = {arg1, arg2}; |
2599 | |
2600 | return tcp_call_bpf(sk, op, nargs: 2, args); |
2601 | } |
2602 | |
2603 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, |
2604 | u32 arg3) |
2605 | { |
2606 | u32 args[3] = {arg1, arg2, arg3}; |
2607 | |
2608 | return tcp_call_bpf(sk, op, nargs: 3, args); |
2609 | } |
2610 | |
2611 | #else |
2612 | static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) |
2613 | { |
2614 | return -EPERM; |
2615 | } |
2616 | |
2617 | static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) |
2618 | { |
2619 | return -EPERM; |
2620 | } |
2621 | |
2622 | static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, |
2623 | u32 arg3) |
2624 | { |
2625 | return -EPERM; |
2626 | } |
2627 | |
2628 | #endif |
2629 | |
2630 | static inline u32 tcp_timeout_init(struct sock *sk) |
2631 | { |
2632 | int timeout; |
2633 | |
2634 | timeout = tcp_call_bpf(sk, op: BPF_SOCK_OPS_TIMEOUT_INIT, nargs: 0, NULL); |
2635 | |
2636 | if (timeout <= 0) |
2637 | timeout = TCP_TIMEOUT_INIT; |
2638 | return min_t(int, timeout, TCP_RTO_MAX); |
2639 | } |
2640 | |
2641 | static inline u32 tcp_rwnd_init_bpf(struct sock *sk) |
2642 | { |
2643 | int rwnd; |
2644 | |
2645 | rwnd = tcp_call_bpf(sk, op: BPF_SOCK_OPS_RWND_INIT, nargs: 0, NULL); |
2646 | |
2647 | if (rwnd < 0) |
2648 | rwnd = 0; |
2649 | return rwnd; |
2650 | } |
2651 | |
2652 | static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) |
2653 | { |
2654 | return (tcp_call_bpf(sk, op: BPF_SOCK_OPS_NEEDS_ECN, nargs: 0, NULL) == 1); |
2655 | } |
2656 | |
2657 | static inline void tcp_bpf_rtt(struct sock *sk) |
2658 | { |
2659 | if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_RTT_CB_FLAG)) |
2660 | tcp_call_bpf(sk, op: BPF_SOCK_OPS_RTT_CB, nargs: 0, NULL); |
2661 | } |
2662 | |
2663 | #if IS_ENABLED(CONFIG_SMC) |
2664 | extern struct static_key_false tcp_have_smc; |
2665 | #endif |
2666 | |
2667 | #if IS_ENABLED(CONFIG_TLS_DEVICE) |
2668 | void clean_acked_data_enable(struct inet_connection_sock *icsk, |
2669 | void (*cad)(struct sock *sk, u32 ack_seq)); |
2670 | void clean_acked_data_disable(struct inet_connection_sock *icsk); |
2671 | void clean_acked_data_flush(void); |
2672 | #endif |
2673 | |
2674 | DECLARE_STATIC_KEY_FALSE(tcp_tx_delay_enabled); |
2675 | static inline void tcp_add_tx_delay(struct sk_buff *skb, |
2676 | const struct tcp_sock *tp) |
2677 | { |
2678 | if (static_branch_unlikely(&tcp_tx_delay_enabled)) |
2679 | skb->skb_mstamp_ns += (u64)tp->tcp_tx_delay * NSEC_PER_USEC; |
2680 | } |
2681 | |
2682 | /* Compute Earliest Departure Time for some control packets |
2683 | * like ACK or RST for TIME_WAIT or non ESTABLISHED sockets. |
2684 | */ |
2685 | static inline u64 tcp_transmit_time(const struct sock *sk) |
2686 | { |
2687 | if (static_branch_unlikely(&tcp_tx_delay_enabled)) { |
2688 | u32 delay = (sk->sk_state == TCP_TIME_WAIT) ? |
2689 | tcp_twsk(sk)->tw_tx_delay : tcp_sk(sk)->tcp_tx_delay; |
2690 | |
2691 | return tcp_clock_ns() + (u64)delay * NSEC_PER_USEC; |
2692 | } |
2693 | return 0; |
2694 | } |
2695 | |
2696 | static inline int tcp_parse_auth_options(const struct tcphdr *th, |
2697 | const u8 **md5_hash, const struct tcp_ao_hdr **aoh) |
2698 | { |
2699 | const u8 *md5_tmp, *ao_tmp; |
2700 | int ret; |
2701 | |
2702 | ret = tcp_do_parse_auth_options(th, md5_hash: &md5_tmp, ao_hash: &ao_tmp); |
2703 | if (ret) |
2704 | return ret; |
2705 | |
2706 | if (md5_hash) |
2707 | *md5_hash = md5_tmp; |
2708 | |
2709 | if (aoh) { |
2710 | if (!ao_tmp) |
2711 | *aoh = NULL; |
2712 | else |
2713 | *aoh = (struct tcp_ao_hdr *)(ao_tmp - 2); |
2714 | } |
2715 | |
2716 | return 0; |
2717 | } |
2718 | |
2719 | static inline bool tcp_ao_required(struct sock *sk, const void *saddr, |
2720 | int family, int l3index, bool stat_inc) |
2721 | { |
2722 | #ifdef CONFIG_TCP_AO |
2723 | struct tcp_ao_info *ao_info; |
2724 | struct tcp_ao_key *ao_key; |
2725 | |
2726 | if (!static_branch_unlikely(&tcp_ao_needed.key)) |
2727 | return false; |
2728 | |
2729 | ao_info = rcu_dereference_check(tcp_sk(sk)->ao_info, |
2730 | lockdep_sock_is_held(sk)); |
2731 | if (!ao_info) |
2732 | return false; |
2733 | |
2734 | ao_key = tcp_ao_do_lookup(sk, l3index, addr: saddr, family, sndid: -1, rcvid: -1); |
2735 | if (ao_info->ao_required || ao_key) { |
2736 | if (stat_inc) { |
2737 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOREQUIRED); |
2738 | atomic64_inc(v: &ao_info->counters.ao_required); |
2739 | } |
2740 | return true; |
2741 | } |
2742 | #endif |
2743 | return false; |
2744 | } |
2745 | |
2746 | /* Called with rcu_read_lock() */ |
2747 | static inline enum skb_drop_reason |
2748 | tcp_inbound_hash(struct sock *sk, const struct request_sock *req, |
2749 | const struct sk_buff *skb, |
2750 | const void *saddr, const void *daddr, |
2751 | int family, int dif, int sdif) |
2752 | { |
2753 | const struct tcphdr *th = tcp_hdr(skb); |
2754 | const struct tcp_ao_hdr *aoh; |
2755 | const __u8 *md5_location; |
2756 | int l3index; |
2757 | |
2758 | /* Invalid option or two times meet any of auth options */ |
2759 | if (tcp_parse_auth_options(th, md5_hash: &md5_location, aoh: &aoh)) { |
2760 | tcp_hash_fail("TCP segment has incorrect auth options set" , |
2761 | family, skb, "" ); |
2762 | return SKB_DROP_REASON_TCP_AUTH_HDR; |
2763 | } |
2764 | |
2765 | if (req) { |
2766 | if (tcp_rsk_used_ao(req) != !!aoh) { |
2767 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD); |
2768 | tcp_hash_fail("TCP connection can't start/end using TCP-AO" , |
2769 | family, skb, "%s" , |
2770 | !aoh ? "missing AO" : "AO signed" ); |
2771 | return SKB_DROP_REASON_TCP_AOFAILURE; |
2772 | } |
2773 | } |
2774 | |
2775 | /* sdif set, means packet ingressed via a device |
2776 | * in an L3 domain and dif is set to the l3mdev |
2777 | */ |
2778 | l3index = sdif ? dif : 0; |
2779 | |
2780 | /* Fast path: unsigned segments */ |
2781 | if (likely(!md5_location && !aoh)) { |
2782 | /* Drop if there's TCP-MD5 or TCP-AO key with any rcvid/sndid |
2783 | * for the remote peer. On TCP-AO established connection |
2784 | * the last key is impossible to remove, so there's |
2785 | * always at least one current_key. |
2786 | */ |
2787 | if (tcp_ao_required(sk, saddr, family, l3index, stat_inc: true)) { |
2788 | tcp_hash_fail("AO hash is required, but not found" , |
2789 | family, skb, "L3 index %d" , l3index); |
2790 | return SKB_DROP_REASON_TCP_AONOTFOUND; |
2791 | } |
2792 | if (unlikely(tcp_md5_do_lookup(sk, l3index, saddr, family))) { |
2793 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); |
2794 | tcp_hash_fail("MD5 Hash not found" , |
2795 | family, skb, "L3 index %d" , l3index); |
2796 | return SKB_DROP_REASON_TCP_MD5NOTFOUND; |
2797 | } |
2798 | return SKB_NOT_DROPPED_YET; |
2799 | } |
2800 | |
2801 | if (aoh) |
2802 | return tcp_inbound_ao_hash(sk, skb, family, req, l3index, aoh); |
2803 | |
2804 | return tcp_inbound_md5_hash(sk, skb, saddr, daddr, family, |
2805 | l3index, hash_location: md5_location); |
2806 | } |
2807 | |
2808 | #endif /* _TCP_H */ |
2809 | |