1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * Definitions for the TCP module. 8 * 9 * Version: @(#)tcp.h 1.0.5 05/23/93 10 * 11 * Authors: Ross Biro 12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 13 */ 14 #ifndef _TCP_H 15 #define _TCP_H 16 17 #define FASTRETRANS_DEBUG 1 18 19 #include <linux/list.h> 20 #include <linux/tcp.h> 21 #include <linux/bug.h> 22 #include <linux/slab.h> 23 #include <linux/cache.h> 24 #include <linux/percpu.h> 25 #include <linux/skbuff.h> 26 #include <linux/kref.h> 27 #include <linux/ktime.h> 28 #include <linux/indirect_call_wrapper.h> 29 #include <linux/bits.h> 30 31 #include <net/inet_connection_sock.h> 32 #include <net/inet_timewait_sock.h> 33 #include <net/inet_hashtables.h> 34 #include <net/checksum.h> 35 #include <net/request_sock.h> 36 #include <net/sock_reuseport.h> 37 #include <net/sock.h> 38 #include <net/snmp.h> 39 #include <net/ip.h> 40 #include <net/tcp_states.h> 41 #include <net/tcp_ao.h> 42 #include <net/inet_ecn.h> 43 #include <net/dst.h> 44 #include <net/mptcp.h> 45 #include <net/xfrm.h> 46 47 #include <linux/seq_file.h> 48 #include <linux/memcontrol.h> 49 #include <linux/bpf-cgroup.h> 50 #include <linux/siphash.h> 51 52 extern struct inet_hashinfo tcp_hashinfo; 53 54 DECLARE_PER_CPU(unsigned int, tcp_orphan_count); 55 int tcp_orphan_count_sum(void); 56 57 DECLARE_PER_CPU(u32, tcp_tw_isn); 58 59 void tcp_time_wait(struct sock *sk, int state, int timeo); 60 61 #define MAX_TCP_HEADER L1_CACHE_ALIGN(128 + MAX_HEADER) 62 #define MAX_TCP_OPTION_SPACE 40 63 #define TCP_MIN_SND_MSS 48 64 #define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE) 65 66 /* 67 * Never offer a window over 32767 without using window scaling. Some 68 * poor stacks do signed 16bit maths! 69 */ 70 #define MAX_TCP_WINDOW 32767U 71 72 /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ 73 #define TCP_MIN_MSS 88U 74 75 /* The initial MTU to use for probing */ 76 #define TCP_BASE_MSS 1024 77 78 /* probing interval, default to 10 minutes as per RFC4821 */ 79 #define TCP_PROBE_INTERVAL 600 80 81 /* Specify interval when tcp mtu probing will stop */ 82 #define TCP_PROBE_THRESHOLD 8 83 84 /* After receiving this amount of duplicate ACKs fast retransmit starts. */ 85 #define TCP_FASTRETRANS_THRESH 3 86 87 /* Maximal number of ACKs sent quickly to accelerate slow-start. */ 88 #define TCP_MAX_QUICKACKS 16U 89 90 /* Maximal number of window scale according to RFC1323 */ 91 #define TCP_MAX_WSCALE 14U 92 93 /* urg_data states */ 94 #define TCP_URG_VALID 0x0100 95 #define TCP_URG_NOTYET 0x0200 96 #define TCP_URG_READ 0x0400 97 98 #define TCP_RETR1 3 /* 99 * This is how many retries it does before it 100 * tries to figure out if the gateway is 101 * down. Minimal RFC value is 3; it corresponds 102 * to ~3sec-8min depending on RTO. 103 */ 104 105 #define TCP_RETR2 15 /* 106 * This should take at least 107 * 90 minutes to time out. 108 * RFC1122 says that the limit is 100 sec. 109 * 15 is ~13-30min depending on RTO. 110 */ 111 112 #define TCP_SYN_RETRIES 6 /* This is how many retries are done 113 * when active opening a connection. 114 * RFC1122 says the minimum retry MUST 115 * be at least 180secs. Nevertheless 116 * this value is corresponding to 117 * 63secs of retransmission with the 118 * current initial RTO. 119 */ 120 121 #define TCP_SYNACK_RETRIES 5 /* This is how may retries are done 122 * when passive opening a connection. 123 * This is corresponding to 31secs of 124 * retransmission with the current 125 * initial RTO. 126 */ 127 128 #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT 129 * state, about 60 seconds */ 130 #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN 131 /* BSD style FIN_WAIT2 deadlock breaker. 132 * It used to be 3min, new value is 60sec, 133 * to combine FIN-WAIT-2 timeout with 134 * TIME-WAIT timer. 135 */ 136 #define TCP_FIN_TIMEOUT_MAX (120 * HZ) /* max TCP_LINGER2 value (two minutes) */ 137 138 #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ 139 static_assert((1 << ATO_BITS) > TCP_DELACK_MAX); 140 141 #if HZ >= 100 142 #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ 143 #define TCP_ATO_MIN ((unsigned)(HZ/25)) 144 #else 145 #define TCP_DELACK_MIN 4U 146 #define TCP_ATO_MIN 4U 147 #endif 148 #define TCP_RTO_MAX_SEC 120 149 #define TCP_RTO_MAX ((unsigned)(TCP_RTO_MAX_SEC * HZ)) 150 #define TCP_RTO_MIN ((unsigned)(HZ / 5)) 151 #define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ 152 153 #define TCP_TIMEOUT_MIN_US (2*USEC_PER_MSEC) /* Min TCP timeout in microsecs */ 154 155 #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ 156 #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now 157 * used as a fallback RTO for the 158 * initial data transmission if no 159 * valid RTT sample has been acquired, 160 * most likely due to retrans in 3WHS. 161 */ 162 163 #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes 164 * for local resources. 165 */ 166 #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ 167 #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ 168 #define TCP_KEEPALIVE_INTVL (75*HZ) 169 170 #define MAX_TCP_KEEPIDLE 32767 171 #define MAX_TCP_KEEPINTVL 32767 172 #define MAX_TCP_KEEPCNT 127 173 #define MAX_TCP_SYNCNT 127 174 175 /* Ensure that TCP PAWS checks are relaxed after ~2147 seconds 176 * to avoid overflows. This assumes a clock smaller than 1 Mhz. 177 * Default clock is 1 Khz, tcp_usec_ts uses 1 Mhz. 178 */ 179 #define TCP_PAWS_WRAP (INT_MAX / USEC_PER_SEC) 180 181 #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated 182 * after this time. It should be equal 183 * (or greater than) TCP_TIMEWAIT_LEN 184 * to provide reliability equal to one 185 * provided by timewait state. 186 */ 187 #define TCP_PAWS_WINDOW 1 /* Replay window for per-host 188 * timestamps. It must be less than 189 * minimal timewait lifetime. 190 */ 191 /* 192 * TCP option 193 */ 194 195 #define TCPOPT_NOP 1 /* Padding */ 196 #define TCPOPT_EOL 0 /* End of options */ 197 #define TCPOPT_MSS 2 /* Segment size negotiating */ 198 #define TCPOPT_WINDOW 3 /* Window scaling */ 199 #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ 200 #define TCPOPT_SACK 5 /* SACK Block */ 201 #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ 202 #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ 203 #define TCPOPT_AO 29 /* Authentication Option (RFC5925) */ 204 #define TCPOPT_MPTCP 30 /* Multipath TCP (RFC6824) */ 205 #define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ 206 #define TCPOPT_EXP 254 /* Experimental */ 207 /* Magic number to be after the option value for sharing TCP 208 * experimental options. See draft-ietf-tcpm-experimental-options-00.txt 209 */ 210 #define TCPOPT_FASTOPEN_MAGIC 0xF989 211 #define TCPOPT_SMC_MAGIC 0xE2D4C3D9 212 213 /* 214 * TCP option lengths 215 */ 216 217 #define TCPOLEN_MSS 4 218 #define TCPOLEN_WINDOW 3 219 #define TCPOLEN_SACK_PERM 2 220 #define TCPOLEN_TIMESTAMP 10 221 #define TCPOLEN_MD5SIG 18 222 #define TCPOLEN_FASTOPEN_BASE 2 223 #define TCPOLEN_EXP_FASTOPEN_BASE 4 224 #define TCPOLEN_EXP_SMC_BASE 6 225 226 /* But this is what stacks really send out. */ 227 #define TCPOLEN_TSTAMP_ALIGNED 12 228 #define TCPOLEN_WSCALE_ALIGNED 4 229 #define TCPOLEN_SACKPERM_ALIGNED 4 230 #define TCPOLEN_SACK_BASE 2 231 #define TCPOLEN_SACK_BASE_ALIGNED 4 232 #define TCPOLEN_SACK_PERBLOCK 8 233 #define TCPOLEN_MD5SIG_ALIGNED 20 234 #define TCPOLEN_MSS_ALIGNED 4 235 #define TCPOLEN_EXP_SMC_BASE_ALIGNED 8 236 237 /* Flags in tp->nonagle */ 238 #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ 239 #define TCP_NAGLE_CORK 2 /* Socket is corked */ 240 #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ 241 242 /* TCP thin-stream limits */ 243 #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ 244 245 /* TCP initial congestion window as per rfc6928 */ 246 #define TCP_INIT_CWND 10 247 248 /* Bit Flags for sysctl_tcp_fastopen */ 249 #define TFO_CLIENT_ENABLE 1 250 #define TFO_SERVER_ENABLE 2 251 #define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ 252 253 /* Accept SYN data w/o any cookie option */ 254 #define TFO_SERVER_COOKIE_NOT_REQD 0x200 255 256 /* Force enable TFO on all listeners, i.e., not requiring the 257 * TCP_FASTOPEN socket option. 258 */ 259 #define TFO_SERVER_WO_SOCKOPT1 0x400 260 261 262 /* sysctl variables for tcp */ 263 extern int sysctl_tcp_max_orphans; 264 extern long sysctl_tcp_mem[3]; 265 266 #define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ 267 #define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */ 268 #define TCP_RACK_NO_DUPTHRESH 0x4 /* Do not use DUPACK threshold in RACK */ 269 270 extern atomic_long_t tcp_memory_allocated; 271 DECLARE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc); 272 273 extern struct percpu_counter tcp_sockets_allocated; 274 extern unsigned long tcp_memory_pressure; 275 276 /* optimized version of sk_under_memory_pressure() for TCP sockets */ 277 static inline bool tcp_under_memory_pressure(const struct sock *sk) 278 { 279 if (mem_cgroup_sockets_enabled && sk->sk_memcg && 280 mem_cgroup_under_socket_pressure(sk->sk_memcg)) 281 return true; 282 283 return READ_ONCE(tcp_memory_pressure); 284 } 285 /* 286 * The next routines deal with comparing 32 bit unsigned ints 287 * and worry about wraparound (automatic with unsigned arithmetic). 288 */ 289 290 static inline bool before(__u32 seq1, __u32 seq2) 291 { 292 return (__s32)(seq1-seq2) < 0; 293 } 294 #define after(seq2, seq1) before(seq1, seq2) 295 296 /* is s2<=s1<=s3 ? */ 297 static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) 298 { 299 return seq3 - seq2 >= seq1 - seq2; 300 } 301 302 static inline void tcp_wmem_free_skb(struct sock *sk, struct sk_buff *skb) 303 { 304 sk_wmem_queued_add(sk, -skb->truesize); 305 if (!skb_zcopy_pure(skb)) 306 sk_mem_uncharge(sk, skb->truesize); 307 else 308 sk_mem_uncharge(sk, SKB_TRUESIZE(skb_end_offset(skb))); 309 __kfree_skb(skb); 310 } 311 312 void sk_forced_mem_schedule(struct sock *sk, int size); 313 314 bool tcp_check_oom(const struct sock *sk, int shift); 315 316 317 extern struct proto tcp_prot; 318 319 #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) 320 #define __TCP_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.tcp_statistics, field) 321 #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) 322 #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) 323 324 void tcp_tsq_work_init(void); 325 326 int tcp_v4_err(struct sk_buff *skb, u32); 327 328 void tcp_shutdown(struct sock *sk, int how); 329 330 int tcp_v4_early_demux(struct sk_buff *skb); 331 int tcp_v4_rcv(struct sk_buff *skb); 332 333 void tcp_remove_empty_skb(struct sock *sk); 334 int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); 335 int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size); 336 int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied, 337 size_t size, struct ubuf_info *uarg); 338 void tcp_splice_eof(struct socket *sock); 339 int tcp_send_mss(struct sock *sk, int *size_goal, int flags); 340 int tcp_wmem_schedule(struct sock *sk, int copy); 341 void tcp_push(struct sock *sk, int flags, int mss_now, int nonagle, 342 int size_goal); 343 void tcp_release_cb(struct sock *sk); 344 void tcp_wfree(struct sk_buff *skb); 345 void tcp_write_timer_handler(struct sock *sk); 346 void tcp_delack_timer_handler(struct sock *sk); 347 int tcp_ioctl(struct sock *sk, int cmd, int *karg); 348 enum skb_drop_reason tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); 349 void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); 350 void tcp_rcv_space_adjust(struct sock *sk); 351 int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); 352 void tcp_twsk_destructor(struct sock *sk); 353 void tcp_twsk_purge(struct list_head *net_exit_list); 354 ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, 355 struct pipe_inode_info *pipe, size_t len, 356 unsigned int flags); 357 struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, gfp_t gfp, 358 bool force_schedule); 359 360 static inline void tcp_dec_quickack_mode(struct sock *sk) 361 { 362 struct inet_connection_sock *icsk = inet_csk(sk); 363 364 if (icsk->icsk_ack.quick) { 365 /* How many ACKs S/ACKing new data have we sent? */ 366 const unsigned int pkts = inet_csk_ack_scheduled(sk) ? 1 : 0; 367 368 if (pkts >= icsk->icsk_ack.quick) { 369 icsk->icsk_ack.quick = 0; 370 /* Leaving quickack mode we deflate ATO. */ 371 icsk->icsk_ack.ato = TCP_ATO_MIN; 372 } else 373 icsk->icsk_ack.quick -= pkts; 374 } 375 } 376 377 #define TCP_ECN_MODE_RFC3168 BIT(0) 378 #define TCP_ECN_QUEUE_CWR BIT(1) 379 #define TCP_ECN_DEMAND_CWR BIT(2) 380 #define TCP_ECN_SEEN BIT(3) 381 #define TCP_ECN_MODE_ACCECN BIT(4) 382 383 #define TCP_ECN_DISABLED 0 384 #define TCP_ECN_MODE_PENDING (TCP_ECN_MODE_RFC3168 | TCP_ECN_MODE_ACCECN) 385 #define TCP_ECN_MODE_ANY (TCP_ECN_MODE_RFC3168 | TCP_ECN_MODE_ACCECN) 386 387 static inline bool tcp_ecn_mode_any(const struct tcp_sock *tp) 388 { 389 return tp->ecn_flags & TCP_ECN_MODE_ANY; 390 } 391 392 static inline bool tcp_ecn_mode_rfc3168(const struct tcp_sock *tp) 393 { 394 return (tp->ecn_flags & TCP_ECN_MODE_ANY) == TCP_ECN_MODE_RFC3168; 395 } 396 397 static inline bool tcp_ecn_mode_accecn(const struct tcp_sock *tp) 398 { 399 return (tp->ecn_flags & TCP_ECN_MODE_ANY) == TCP_ECN_MODE_ACCECN; 400 } 401 402 static inline bool tcp_ecn_disabled(const struct tcp_sock *tp) 403 { 404 return !tcp_ecn_mode_any(tp); 405 } 406 407 static inline bool tcp_ecn_mode_pending(const struct tcp_sock *tp) 408 { 409 return (tp->ecn_flags & TCP_ECN_MODE_PENDING) == TCP_ECN_MODE_PENDING; 410 } 411 412 static inline void tcp_ecn_mode_set(struct tcp_sock *tp, u8 mode) 413 { 414 tp->ecn_flags &= ~TCP_ECN_MODE_ANY; 415 tp->ecn_flags |= mode; 416 } 417 418 enum tcp_tw_status { 419 TCP_TW_SUCCESS = 0, 420 TCP_TW_RST = 1, 421 TCP_TW_ACK = 2, 422 TCP_TW_SYN = 3, 423 TCP_TW_ACK_OOW = 4 424 }; 425 426 427 enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, 428 struct sk_buff *skb, 429 const struct tcphdr *th, 430 u32 *tw_isn, 431 enum skb_drop_reason *drop_reason); 432 struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, 433 struct request_sock *req, bool fastopen, 434 bool *lost_race, enum skb_drop_reason *drop_reason); 435 enum skb_drop_reason tcp_child_process(struct sock *parent, struct sock *child, 436 struct sk_buff *skb); 437 void tcp_enter_loss(struct sock *sk); 438 void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int newly_lost, int flag); 439 void tcp_clear_retrans(struct tcp_sock *tp); 440 void tcp_update_metrics(struct sock *sk); 441 void tcp_init_metrics(struct sock *sk); 442 void tcp_metrics_init(void); 443 bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst); 444 void __tcp_close(struct sock *sk, long timeout); 445 void tcp_close(struct sock *sk, long timeout); 446 void tcp_init_sock(struct sock *sk); 447 void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb); 448 __poll_t tcp_poll(struct file *file, struct socket *sock, 449 struct poll_table_struct *wait); 450 int do_tcp_getsockopt(struct sock *sk, int level, 451 int optname, sockptr_t optval, sockptr_t optlen); 452 int tcp_getsockopt(struct sock *sk, int level, int optname, 453 char __user *optval, int __user *optlen); 454 bool tcp_bpf_bypass_getsockopt(int level, int optname); 455 int do_tcp_setsockopt(struct sock *sk, int level, int optname, 456 sockptr_t optval, unsigned int optlen); 457 int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 458 unsigned int optlen); 459 void tcp_reset_keepalive_timer(struct sock *sk, unsigned long timeout); 460 void tcp_set_keepalive(struct sock *sk, int val); 461 void tcp_syn_ack_timeout(const struct request_sock *req); 462 int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 463 int flags, int *addr_len); 464 int tcp_set_rcvlowat(struct sock *sk, int val); 465 int tcp_set_window_clamp(struct sock *sk, int val); 466 void tcp_update_recv_tstamps(struct sk_buff *skb, 467 struct scm_timestamping_internal *tss); 468 void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, 469 struct scm_timestamping_internal *tss); 470 void tcp_data_ready(struct sock *sk); 471 #ifdef CONFIG_MMU 472 int tcp_mmap(struct file *file, struct socket *sock, 473 struct vm_area_struct *vma); 474 #endif 475 void tcp_parse_options(const struct net *net, const struct sk_buff *skb, 476 struct tcp_options_received *opt_rx, 477 int estab, struct tcp_fastopen_cookie *foc); 478 479 /* 480 * BPF SKB-less helpers 481 */ 482 u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, 483 struct tcphdr *th, u32 *cookie); 484 u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, 485 struct tcphdr *th, u32 *cookie); 486 u16 tcp_parse_mss_option(const struct tcphdr *th, u16 user_mss); 487 u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, 488 const struct tcp_request_sock_ops *af_ops, 489 struct sock *sk, struct tcphdr *th); 490 /* 491 * TCP v4 functions exported for the inet6 API 492 */ 493 494 void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); 495 void tcp_v4_mtu_reduced(struct sock *sk); 496 void tcp_req_err(struct sock *sk, u32 seq, bool abort); 497 void tcp_ld_RTO_revert(struct sock *sk, u32 seq); 498 int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); 499 struct sock *tcp_create_openreq_child(const struct sock *sk, 500 struct request_sock *req, 501 struct sk_buff *skb); 502 void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); 503 struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, 504 struct request_sock *req, 505 struct dst_entry *dst, 506 struct request_sock *req_unhash, 507 bool *own_req); 508 int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); 509 int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 510 int tcp_connect(struct sock *sk); 511 enum tcp_synack_type { 512 TCP_SYNACK_NORMAL, 513 TCP_SYNACK_FASTOPEN, 514 TCP_SYNACK_COOKIE, 515 }; 516 struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, 517 struct request_sock *req, 518 struct tcp_fastopen_cookie *foc, 519 enum tcp_synack_type synack_type, 520 struct sk_buff *syn_skb); 521 int tcp_disconnect(struct sock *sk, int flags); 522 523 void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); 524 int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); 525 void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); 526 527 /* From syncookies.c */ 528 struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, 529 struct request_sock *req, 530 struct dst_entry *dst); 531 int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th); 532 struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); 533 struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, 534 struct sock *sk, struct sk_buff *skb, 535 struct tcp_options_received *tcp_opt, 536 int mss, u32 tsoff); 537 538 #if IS_ENABLED(CONFIG_BPF) 539 struct bpf_tcp_req_attrs { 540 u32 rcv_tsval; 541 u32 rcv_tsecr; 542 u16 mss; 543 u8 rcv_wscale; 544 u8 snd_wscale; 545 u8 ecn_ok; 546 u8 wscale_ok; 547 u8 sack_ok; 548 u8 tstamp_ok; 549 u8 usec_ts_ok; 550 u8 reserved[3]; 551 }; 552 #endif 553 554 #ifdef CONFIG_SYN_COOKIES 555 556 /* Syncookies use a monotonic timer which increments every 60 seconds. 557 * This counter is used both as a hash input and partially encoded into 558 * the cookie value. A cookie is only validated further if the delta 559 * between the current counter value and the encoded one is less than this, 560 * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if 561 * the counter advances immediately after a cookie is generated). 562 */ 563 #define MAX_SYNCOOKIE_AGE 2 564 #define TCP_SYNCOOKIE_PERIOD (60 * HZ) 565 #define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) 566 567 /* syncookies: remember time of last synqueue overflow 568 * But do not dirty this field too often (once per second is enough) 569 * It is racy as we do not hold a lock, but race is very minor. 570 */ 571 static inline void tcp_synq_overflow(const struct sock *sk) 572 { 573 unsigned int last_overflow; 574 unsigned int now = jiffies; 575 576 if (sk->sk_reuseport) { 577 struct sock_reuseport *reuse; 578 579 reuse = rcu_dereference(sk->sk_reuseport_cb); 580 if (likely(reuse)) { 581 last_overflow = READ_ONCE(reuse->synq_overflow_ts); 582 if (!time_between32(now, last_overflow, 583 last_overflow + HZ)) 584 WRITE_ONCE(reuse->synq_overflow_ts, now); 585 return; 586 } 587 } 588 589 last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); 590 if (!time_between32(now, last_overflow, last_overflow + HZ)) 591 WRITE_ONCE(tcp_sk_rw(sk)->rx_opt.ts_recent_stamp, now); 592 } 593 594 /* syncookies: no recent synqueue overflow on this listening socket? */ 595 static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) 596 { 597 unsigned int last_overflow; 598 unsigned int now = jiffies; 599 600 if (sk->sk_reuseport) { 601 struct sock_reuseport *reuse; 602 603 reuse = rcu_dereference(sk->sk_reuseport_cb); 604 if (likely(reuse)) { 605 last_overflow = READ_ONCE(reuse->synq_overflow_ts); 606 return !time_between32(now, last_overflow - HZ, 607 last_overflow + 608 TCP_SYNCOOKIE_VALID); 609 } 610 } 611 612 last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); 613 614 /* If last_overflow <= jiffies <= last_overflow + TCP_SYNCOOKIE_VALID, 615 * then we're under synflood. However, we have to use 616 * 'last_overflow - HZ' as lower bound. That's because a concurrent 617 * tcp_synq_overflow() could update .ts_recent_stamp after we read 618 * jiffies but before we store .ts_recent_stamp into last_overflow, 619 * which could lead to rejecting a valid syncookie. 620 */ 621 return !time_between32(now, last_overflow - HZ, 622 last_overflow + TCP_SYNCOOKIE_VALID); 623 } 624 625 static inline u32 tcp_cookie_time(void) 626 { 627 u64 val = get_jiffies_64(); 628 629 do_div(val, TCP_SYNCOOKIE_PERIOD); 630 return val; 631 } 632 633 /* Convert one nsec 64bit timestamp to ts (ms or usec resolution) */ 634 static inline u64 tcp_ns_to_ts(bool usec_ts, u64 val) 635 { 636 if (usec_ts) 637 return div_u64(val, NSEC_PER_USEC); 638 639 return div_u64(val, NSEC_PER_MSEC); 640 } 641 642 u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, 643 u16 *mssp); 644 __u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); 645 u64 cookie_init_timestamp(struct request_sock *req, u64 now); 646 bool cookie_timestamp_decode(const struct net *net, 647 struct tcp_options_received *opt); 648 649 static inline bool cookie_ecn_ok(const struct net *net, const struct dst_entry *dst) 650 { 651 return READ_ONCE(net->ipv4.sysctl_tcp_ecn) || 652 dst_feature(dst, RTAX_FEATURE_ECN); 653 } 654 655 #if IS_ENABLED(CONFIG_BPF) 656 static inline bool cookie_bpf_ok(struct sk_buff *skb) 657 { 658 return skb->sk; 659 } 660 661 struct request_sock *cookie_bpf_check(struct sock *sk, struct sk_buff *skb); 662 #else 663 static inline bool cookie_bpf_ok(struct sk_buff *skb) 664 { 665 return false; 666 } 667 668 static inline struct request_sock *cookie_bpf_check(struct net *net, struct sock *sk, 669 struct sk_buff *skb) 670 { 671 return NULL; 672 } 673 #endif 674 675 /* From net/ipv6/syncookies.c */ 676 int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th); 677 struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); 678 679 u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, 680 const struct tcphdr *th, u16 *mssp); 681 __u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); 682 #endif 683 /* tcp_output.c */ 684 685 void tcp_skb_entail(struct sock *sk, struct sk_buff *skb); 686 void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb); 687 void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, 688 int nonagle); 689 int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); 690 int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); 691 void tcp_retransmit_timer(struct sock *sk); 692 void tcp_xmit_retransmit_queue(struct sock *); 693 void tcp_simple_retransmit(struct sock *); 694 void tcp_enter_recovery(struct sock *sk, bool ece_ack); 695 int tcp_trim_head(struct sock *, struct sk_buff *, u32); 696 enum tcp_queue { 697 TCP_FRAG_IN_WRITE_QUEUE, 698 TCP_FRAG_IN_RTX_QUEUE, 699 }; 700 int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, 701 struct sk_buff *skb, u32 len, 702 unsigned int mss_now, gfp_t gfp); 703 704 void tcp_send_probe0(struct sock *); 705 int tcp_write_wakeup(struct sock *, int mib); 706 void tcp_send_fin(struct sock *sk); 707 void tcp_send_active_reset(struct sock *sk, gfp_t priority, 708 enum sk_rst_reason reason); 709 int tcp_send_synack(struct sock *); 710 void tcp_push_one(struct sock *, unsigned int mss_now); 711 void __tcp_send_ack(struct sock *sk, u32 rcv_nxt, u16 flags); 712 void tcp_send_ack(struct sock *sk); 713 void tcp_send_delayed_ack(struct sock *sk); 714 void tcp_send_loss_probe(struct sock *sk); 715 bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto); 716 void tcp_skb_collapse_tstamp(struct sk_buff *skb, 717 const struct sk_buff *next_skb); 718 719 /* tcp_input.c */ 720 void tcp_rearm_rto(struct sock *sk); 721 void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); 722 void tcp_done_with_error(struct sock *sk, int err); 723 void tcp_reset(struct sock *sk, struct sk_buff *skb); 724 void tcp_fin(struct sock *sk); 725 void tcp_check_space(struct sock *sk); 726 void tcp_sack_compress_send_ack(struct sock *sk); 727 728 static inline void tcp_cleanup_skb(struct sk_buff *skb) 729 { 730 skb_dst_drop(skb); 731 secpath_reset(skb); 732 } 733 734 static inline void tcp_add_receive_queue(struct sock *sk, struct sk_buff *skb) 735 { 736 DEBUG_NET_WARN_ON_ONCE(skb_dst(skb)); 737 DEBUG_NET_WARN_ON_ONCE(secpath_exists(skb)); 738 __skb_queue_tail(&sk->sk_receive_queue, skb); 739 } 740 741 /* tcp_timer.c */ 742 void tcp_init_xmit_timers(struct sock *); 743 static inline void tcp_clear_xmit_timers(struct sock *sk) 744 { 745 if (hrtimer_try_to_cancel(&tcp_sk(sk)->pacing_timer) == 1) 746 __sock_put(sk); 747 748 if (hrtimer_try_to_cancel(&tcp_sk(sk)->compressed_ack_timer) == 1) 749 __sock_put(sk); 750 751 inet_csk_clear_xmit_timers(sk); 752 } 753 754 unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); 755 unsigned int tcp_current_mss(struct sock *sk); 756 u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when); 757 758 /* Bound MSS / TSO packet size with the half of the window */ 759 static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) 760 { 761 int cutoff; 762 763 /* When peer uses tiny windows, there is no use in packetizing 764 * to sub-MSS pieces for the sake of SWS or making sure there 765 * are enough packets in the pipe for fast recovery. 766 * 767 * On the other hand, for extremely large MSS devices, handling 768 * smaller than MSS windows in this way does make sense. 769 */ 770 if (tp->max_window > TCP_MSS_DEFAULT) 771 cutoff = (tp->max_window >> 1); 772 else 773 cutoff = tp->max_window; 774 775 if (cutoff && pktsize > cutoff) 776 return max_t(int, cutoff, 68U - tp->tcp_header_len); 777 else 778 return pktsize; 779 } 780 781 /* tcp.c */ 782 void tcp_get_info(struct sock *, struct tcp_info *); 783 784 /* Read 'sendfile()'-style from a TCP socket */ 785 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 786 sk_read_actor_t recv_actor); 787 int tcp_read_sock_noack(struct sock *sk, read_descriptor_t *desc, 788 sk_read_actor_t recv_actor, bool noack, 789 u32 *copied_seq); 790 int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor); 791 struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off); 792 void tcp_read_done(struct sock *sk, size_t len); 793 794 void tcp_initialize_rcv_mss(struct sock *sk); 795 796 int tcp_mtu_to_mss(struct sock *sk, int pmtu); 797 int tcp_mss_to_mtu(struct sock *sk, int mss); 798 void tcp_mtup_init(struct sock *sk); 799 800 static inline unsigned int tcp_rto_max(const struct sock *sk) 801 { 802 return READ_ONCE(inet_csk(sk)->icsk_rto_max); 803 } 804 805 static inline void tcp_bound_rto(struct sock *sk) 806 { 807 inet_csk(sk)->icsk_rto = min(inet_csk(sk)->icsk_rto, tcp_rto_max(sk)); 808 } 809 810 static inline u32 __tcp_set_rto(const struct tcp_sock *tp) 811 { 812 return usecs_to_jiffies((tp->srtt_us >> 3) + tp->rttvar_us); 813 } 814 815 static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) 816 { 817 /* mptcp hooks are only on the slow path */ 818 if (sk_is_mptcp((struct sock *)tp)) 819 return; 820 821 tp->pred_flags = htonl((tp->tcp_header_len << 26) | 822 ntohl(TCP_FLAG_ACK) | 823 snd_wnd); 824 } 825 826 static inline void tcp_fast_path_on(struct tcp_sock *tp) 827 { 828 __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); 829 } 830 831 static inline void tcp_fast_path_check(struct sock *sk) 832 { 833 struct tcp_sock *tp = tcp_sk(sk); 834 835 if (RB_EMPTY_ROOT(&tp->out_of_order_queue) && 836 tp->rcv_wnd && 837 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && 838 !tp->urg_data) 839 tcp_fast_path_on(tp); 840 } 841 842 u32 tcp_delack_max(const struct sock *sk); 843 844 /* Compute the actual rto_min value */ 845 static inline u32 tcp_rto_min(const struct sock *sk) 846 { 847 const struct dst_entry *dst = __sk_dst_get(sk); 848 u32 rto_min = READ_ONCE(inet_csk(sk)->icsk_rto_min); 849 850 if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) 851 rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); 852 return rto_min; 853 } 854 855 static inline u32 tcp_rto_min_us(const struct sock *sk) 856 { 857 return jiffies_to_usecs(tcp_rto_min(sk)); 858 } 859 860 static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) 861 { 862 return dst_metric_locked(dst, RTAX_CC_ALGO); 863 } 864 865 /* Minimum RTT in usec. ~0 means not available. */ 866 static inline u32 tcp_min_rtt(const struct tcp_sock *tp) 867 { 868 return minmax_get(&tp->rtt_min); 869 } 870 871 /* Compute the actual receive window we are currently advertising. 872 * Rcv_nxt can be after the window if our peer push more data 873 * than the offered window. 874 */ 875 static inline u32 tcp_receive_window(const struct tcp_sock *tp) 876 { 877 s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; 878 879 if (win < 0) 880 win = 0; 881 return (u32) win; 882 } 883 884 /* Choose a new window, without checks for shrinking, and without 885 * scaling applied to the result. The caller does these things 886 * if necessary. This is a "raw" window selection. 887 */ 888 u32 __tcp_select_window(struct sock *sk); 889 890 void tcp_send_window_probe(struct sock *sk); 891 892 /* TCP uses 32bit jiffies to save some space. 893 * Note that this is different from tcp_time_stamp, which 894 * historically has been the same until linux-4.13. 895 */ 896 #define tcp_jiffies32 ((u32)jiffies) 897 898 /* 899 * Deliver a 32bit value for TCP timestamp option (RFC 7323) 900 * It is no longer tied to jiffies, but to 1 ms clock. 901 * Note: double check if you want to use tcp_jiffies32 instead of this. 902 */ 903 #define TCP_TS_HZ 1000 904 905 static inline u64 tcp_clock_ns(void) 906 { 907 return ktime_get_ns(); 908 } 909 910 static inline u64 tcp_clock_us(void) 911 { 912 return div_u64(tcp_clock_ns(), NSEC_PER_USEC); 913 } 914 915 static inline u64 tcp_clock_ms(void) 916 { 917 return div_u64(tcp_clock_ns(), NSEC_PER_MSEC); 918 } 919 920 /* TCP Timestamp included in TS option (RFC 1323) can either use ms 921 * or usec resolution. Each socket carries a flag to select one or other 922 * resolution, as the route attribute could change anytime. 923 * Each flow must stick to initial resolution. 924 */ 925 static inline u32 tcp_clock_ts(bool usec_ts) 926 { 927 return usec_ts ? tcp_clock_us() : tcp_clock_ms(); 928 } 929 930 static inline u32 tcp_time_stamp_ms(const struct tcp_sock *tp) 931 { 932 return div_u64(tp->tcp_mstamp, USEC_PER_MSEC); 933 } 934 935 static inline u32 tcp_time_stamp_ts(const struct tcp_sock *tp) 936 { 937 if (tp->tcp_usec_ts) 938 return tp->tcp_mstamp; 939 return tcp_time_stamp_ms(tp); 940 } 941 942 void tcp_mstamp_refresh(struct tcp_sock *tp); 943 944 static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) 945 { 946 return max_t(s64, t1 - t0, 0); 947 } 948 949 /* provide the departure time in us unit */ 950 static inline u64 tcp_skb_timestamp_us(const struct sk_buff *skb) 951 { 952 return div_u64(skb->skb_mstamp_ns, NSEC_PER_USEC); 953 } 954 955 /* Provide skb TSval in usec or ms unit */ 956 static inline u32 tcp_skb_timestamp_ts(bool usec_ts, const struct sk_buff *skb) 957 { 958 if (usec_ts) 959 return tcp_skb_timestamp_us(skb); 960 961 return div_u64(skb->skb_mstamp_ns, NSEC_PER_MSEC); 962 } 963 964 static inline u32 tcp_tw_tsval(const struct tcp_timewait_sock *tcptw) 965 { 966 return tcp_clock_ts(tcptw->tw_sk.tw_usec_ts) + tcptw->tw_ts_offset; 967 } 968 969 static inline u32 tcp_rsk_tsval(const struct tcp_request_sock *treq) 970 { 971 return tcp_clock_ts(treq->req_usec_ts) + treq->ts_off; 972 } 973 974 #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) 975 976 #define TCPHDR_FIN BIT(0) 977 #define TCPHDR_SYN BIT(1) 978 #define TCPHDR_RST BIT(2) 979 #define TCPHDR_PSH BIT(3) 980 #define TCPHDR_ACK BIT(4) 981 #define TCPHDR_URG BIT(5) 982 #define TCPHDR_ECE BIT(6) 983 #define TCPHDR_CWR BIT(7) 984 #define TCPHDR_AE BIT(8) 985 #define TCPHDR_FLAGS_MASK (TCPHDR_FIN | TCPHDR_SYN | TCPHDR_RST | \ 986 TCPHDR_PSH | TCPHDR_ACK | TCPHDR_URG | \ 987 TCPHDR_ECE | TCPHDR_CWR | TCPHDR_AE) 988 #define tcp_flags_ntohs(th) (ntohs(*(__be16 *)&tcp_flag_word(th)) & \ 989 TCPHDR_FLAGS_MASK) 990 991 #define TCPHDR_ACE (TCPHDR_ECE | TCPHDR_CWR | TCPHDR_AE) 992 #define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) 993 994 /* State flags for sacked in struct tcp_skb_cb */ 995 enum tcp_skb_cb_sacked_flags { 996 TCPCB_SACKED_ACKED = (1 << 0), /* SKB ACK'd by a SACK block */ 997 TCPCB_SACKED_RETRANS = (1 << 1), /* SKB retransmitted */ 998 TCPCB_LOST = (1 << 2), /* SKB is lost */ 999 TCPCB_TAGBITS = (TCPCB_SACKED_ACKED | TCPCB_SACKED_RETRANS | 1000 TCPCB_LOST), /* All tag bits */ 1001 TCPCB_REPAIRED = (1 << 4), /* SKB repaired (no skb_mstamp_ns) */ 1002 TCPCB_EVER_RETRANS = (1 << 7), /* Ever retransmitted frame */ 1003 TCPCB_RETRANS = (TCPCB_SACKED_RETRANS | TCPCB_EVER_RETRANS | 1004 TCPCB_REPAIRED), 1005 }; 1006 1007 /* This is what the send packet queuing engine uses to pass 1008 * TCP per-packet control information to the transmission code. 1009 * We also store the host-order sequence numbers in here too. 1010 * This is 44 bytes if IPV6 is enabled. 1011 * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. 1012 */ 1013 struct tcp_skb_cb { 1014 __u32 seq; /* Starting sequence number */ 1015 __u32 end_seq; /* SEQ + FIN + SYN + datalen */ 1016 union { 1017 /* Note : 1018 * tcp_gso_segs/size are used in write queue only, 1019 * cf tcp_skb_pcount()/tcp_skb_mss() 1020 */ 1021 struct { 1022 u16 tcp_gso_segs; 1023 u16 tcp_gso_size; 1024 }; 1025 }; 1026 __u16 tcp_flags; /* TCP header flags (tcp[12-13])*/ 1027 1028 __u8 sacked; /* State flags for SACK. */ 1029 __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ 1030 #define TSTAMP_ACK_SK 0x1 1031 #define TSTAMP_ACK_BPF 0x2 1032 __u8 txstamp_ack:2, /* Record TX timestamp for ack? */ 1033 eor:1, /* Is skb MSG_EOR marked? */ 1034 has_rxtstamp:1, /* SKB has a RX timestamp */ 1035 unused:4; 1036 __u32 ack_seq; /* Sequence number ACK'd */ 1037 union { 1038 struct { 1039 #define TCPCB_DELIVERED_CE_MASK ((1U<<20) - 1) 1040 /* There is space for up to 24 bytes */ 1041 __u32 is_app_limited:1, /* cwnd not fully used? */ 1042 delivered_ce:20, 1043 unused:11; 1044 /* pkts S/ACKed so far upon tx of skb, incl retrans: */ 1045 __u32 delivered; 1046 /* start of send pipeline phase */ 1047 u64 first_tx_mstamp; 1048 /* when we reached the "delivered" count */ 1049 u64 delivered_mstamp; 1050 } tx; /* only used for outgoing skbs */ 1051 union { 1052 struct inet_skb_parm h4; 1053 #if IS_ENABLED(CONFIG_IPV6) 1054 struct inet6_skb_parm h6; 1055 #endif 1056 } header; /* For incoming skbs */ 1057 }; 1058 }; 1059 1060 #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) 1061 1062 extern const struct inet_connection_sock_af_ops ipv4_specific; 1063 1064 #if IS_ENABLED(CONFIG_IPV6) 1065 /* This is the variant of inet6_iif() that must be used by TCP, 1066 * as TCP moves IP6CB into a different location in skb->cb[] 1067 */ 1068 static inline int tcp_v6_iif(const struct sk_buff *skb) 1069 { 1070 return TCP_SKB_CB(skb)->header.h6.iif; 1071 } 1072 1073 static inline int tcp_v6_iif_l3_slave(const struct sk_buff *skb) 1074 { 1075 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); 1076 1077 return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; 1078 } 1079 1080 /* TCP_SKB_CB reference means this can not be used from early demux */ 1081 static inline int tcp_v6_sdif(const struct sk_buff *skb) 1082 { 1083 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 1084 if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags)) 1085 return TCP_SKB_CB(skb)->header.h6.iif; 1086 #endif 1087 return 0; 1088 } 1089 1090 extern const struct inet_connection_sock_af_ops ipv6_specific; 1091 1092 INDIRECT_CALLABLE_DECLARE(void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)); 1093 INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *skb)); 1094 void tcp_v6_early_demux(struct sk_buff *skb); 1095 1096 #endif 1097 1098 /* TCP_SKB_CB reference means this can not be used from early demux */ 1099 static inline int tcp_v4_sdif(struct sk_buff *skb) 1100 { 1101 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 1102 if (skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) 1103 return TCP_SKB_CB(skb)->header.h4.iif; 1104 #endif 1105 return 0; 1106 } 1107 1108 /* Due to TSO, an SKB can be composed of multiple actual 1109 * packets. To keep these tracked properly, we use this. 1110 */ 1111 static inline int tcp_skb_pcount(const struct sk_buff *skb) 1112 { 1113 return TCP_SKB_CB(skb)->tcp_gso_segs; 1114 } 1115 1116 static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) 1117 { 1118 TCP_SKB_CB(skb)->tcp_gso_segs = segs; 1119 } 1120 1121 static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) 1122 { 1123 TCP_SKB_CB(skb)->tcp_gso_segs += segs; 1124 } 1125 1126 /* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ 1127 static inline int tcp_skb_mss(const struct sk_buff *skb) 1128 { 1129 return TCP_SKB_CB(skb)->tcp_gso_size; 1130 } 1131 1132 static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) 1133 { 1134 return likely(!TCP_SKB_CB(skb)->eor); 1135 } 1136 1137 static inline bool tcp_skb_can_collapse(const struct sk_buff *to, 1138 const struct sk_buff *from) 1139 { 1140 /* skb_cmp_decrypted() not needed, use tcp_write_collapse_fence() */ 1141 return likely(tcp_skb_can_collapse_to(to) && 1142 mptcp_skb_can_collapse(to, from) && 1143 skb_pure_zcopy_same(to, from) && 1144 skb_frags_readable(to) == skb_frags_readable(from)); 1145 } 1146 1147 static inline bool tcp_skb_can_collapse_rx(const struct sk_buff *to, 1148 const struct sk_buff *from) 1149 { 1150 return likely(mptcp_skb_can_collapse(to, from) && 1151 !skb_cmp_decrypted(to, from)); 1152 } 1153 1154 /* Events passed to congestion control interface */ 1155 enum tcp_ca_event { 1156 CA_EVENT_TX_START, /* first transmit when no packets in flight */ 1157 CA_EVENT_CWND_RESTART, /* congestion window restart */ 1158 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ 1159 CA_EVENT_LOSS, /* loss timeout */ 1160 CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ 1161 CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ 1162 }; 1163 1164 /* Information about inbound ACK, passed to cong_ops->in_ack_event() */ 1165 enum tcp_ca_ack_event_flags { 1166 CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ 1167 CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ 1168 CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ 1169 }; 1170 1171 /* 1172 * Interface for adding new TCP congestion control handlers 1173 */ 1174 #define TCP_CA_NAME_MAX 16 1175 #define TCP_CA_MAX 128 1176 #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) 1177 1178 #define TCP_CA_UNSPEC 0 1179 1180 /* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ 1181 #define TCP_CONG_NON_RESTRICTED BIT(0) 1182 /* Requires ECN/ECT set on all packets */ 1183 #define TCP_CONG_NEEDS_ECN BIT(1) 1184 #define TCP_CONG_MASK (TCP_CONG_NON_RESTRICTED | TCP_CONG_NEEDS_ECN) 1185 1186 union tcp_cc_info; 1187 1188 struct ack_sample { 1189 u32 pkts_acked; 1190 s32 rtt_us; 1191 u32 in_flight; 1192 }; 1193 1194 /* A rate sample measures the number of (original/retransmitted) data 1195 * packets delivered "delivered" over an interval of time "interval_us". 1196 * The tcp_rate.c code fills in the rate sample, and congestion 1197 * control modules that define a cong_control function to run at the end 1198 * of ACK processing can optionally chose to consult this sample when 1199 * setting cwnd and pacing rate. 1200 * A sample is invalid if "delivered" or "interval_us" is negative. 1201 */ 1202 struct rate_sample { 1203 u64 prior_mstamp; /* starting timestamp for interval */ 1204 u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ 1205 u32 prior_delivered_ce;/* tp->delivered_ce at "prior_mstamp" */ 1206 s32 delivered; /* number of packets delivered over interval */ 1207 s32 delivered_ce; /* number of packets delivered w/ CE marks*/ 1208 long interval_us; /* time for tp->delivered to incr "delivered" */ 1209 u32 snd_interval_us; /* snd interval for delivered packets */ 1210 u32 rcv_interval_us; /* rcv interval for delivered packets */ 1211 long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ 1212 int losses; /* number of packets marked lost upon ACK */ 1213 u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ 1214 u32 prior_in_flight; /* in flight before this ACK */ 1215 u32 last_end_seq; /* end_seq of most recently ACKed packet */ 1216 bool is_app_limited; /* is sample from packet with bubble in pipe? */ 1217 bool is_retrans; /* is sample from retransmission? */ 1218 bool is_ack_delayed; /* is this (likely) a delayed ACK? */ 1219 }; 1220 1221 struct tcp_congestion_ops { 1222 /* fast path fields are put first to fill one cache line */ 1223 1224 /* return slow start threshold (required) */ 1225 u32 (*ssthresh)(struct sock *sk); 1226 1227 /* do new cwnd calculation (required) */ 1228 void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); 1229 1230 /* call before changing ca_state (optional) */ 1231 void (*set_state)(struct sock *sk, u8 new_state); 1232 1233 /* call when cwnd event occurs (optional) */ 1234 void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); 1235 1236 /* call when ack arrives (optional) */ 1237 void (*in_ack_event)(struct sock *sk, u32 flags); 1238 1239 /* hook for packet ack accounting (optional) */ 1240 void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); 1241 1242 /* override sysctl_tcp_min_tso_segs */ 1243 u32 (*min_tso_segs)(struct sock *sk); 1244 1245 /* call when packets are delivered to update cwnd and pacing rate, 1246 * after all the ca_state processing. (optional) 1247 */ 1248 void (*cong_control)(struct sock *sk, u32 ack, int flag, const struct rate_sample *rs); 1249 1250 1251 /* new value of cwnd after loss (required) */ 1252 u32 (*undo_cwnd)(struct sock *sk); 1253 /* returns the multiplier used in tcp_sndbuf_expand (optional) */ 1254 u32 (*sndbuf_expand)(struct sock *sk); 1255 1256 /* control/slow paths put last */ 1257 /* get info for inet_diag (optional) */ 1258 size_t (*get_info)(struct sock *sk, u32 ext, int *attr, 1259 union tcp_cc_info *info); 1260 1261 char name[TCP_CA_NAME_MAX]; 1262 struct module *owner; 1263 struct list_head list; 1264 u32 key; 1265 u32 flags; 1266 1267 /* initialize private data (optional) */ 1268 void (*init)(struct sock *sk); 1269 /* cleanup private data (optional) */ 1270 void (*release)(struct sock *sk); 1271 } ____cacheline_aligned_in_smp; 1272 1273 int tcp_register_congestion_control(struct tcp_congestion_ops *type); 1274 void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); 1275 int tcp_update_congestion_control(struct tcp_congestion_ops *type, 1276 struct tcp_congestion_ops *old_type); 1277 int tcp_validate_congestion_control(struct tcp_congestion_ops *ca); 1278 1279 void tcp_assign_congestion_control(struct sock *sk); 1280 void tcp_init_congestion_control(struct sock *sk); 1281 void tcp_cleanup_congestion_control(struct sock *sk); 1282 int tcp_set_default_congestion_control(struct net *net, const char *name); 1283 void tcp_get_default_congestion_control(struct net *net, char *name); 1284 void tcp_get_available_congestion_control(char *buf, size_t len); 1285 void tcp_get_allowed_congestion_control(char *buf, size_t len); 1286 int tcp_set_allowed_congestion_control(char *allowed); 1287 int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, 1288 bool cap_net_admin); 1289 u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); 1290 void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); 1291 1292 u32 tcp_reno_ssthresh(struct sock *sk); 1293 u32 tcp_reno_undo_cwnd(struct sock *sk); 1294 void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); 1295 extern struct tcp_congestion_ops tcp_reno; 1296 1297 struct tcp_congestion_ops *tcp_ca_find(const char *name); 1298 struct tcp_congestion_ops *tcp_ca_find_key(u32 key); 1299 u32 tcp_ca_get_key_by_name(const char *name, bool *ecn_ca); 1300 #ifdef CONFIG_INET 1301 char *tcp_ca_get_name_by_key(u32 key, char *buffer); 1302 #else 1303 static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) 1304 { 1305 return NULL; 1306 } 1307 #endif 1308 1309 static inline bool tcp_ca_needs_ecn(const struct sock *sk) 1310 { 1311 const struct inet_connection_sock *icsk = inet_csk(sk); 1312 1313 return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; 1314 } 1315 1316 static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) 1317 { 1318 const struct inet_connection_sock *icsk = inet_csk(sk); 1319 1320 if (icsk->icsk_ca_ops->cwnd_event) 1321 icsk->icsk_ca_ops->cwnd_event(sk, event); 1322 } 1323 1324 /* From tcp_cong.c */ 1325 void tcp_set_ca_state(struct sock *sk, const u8 ca_state); 1326 1327 /* From tcp_rate.c */ 1328 void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); 1329 void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, 1330 struct rate_sample *rs); 1331 void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, 1332 bool is_sack_reneg, struct rate_sample *rs); 1333 void tcp_rate_check_app_limited(struct sock *sk); 1334 1335 static inline bool tcp_skb_sent_after(u64 t1, u64 t2, u32 seq1, u32 seq2) 1336 { 1337 return t1 > t2 || (t1 == t2 && after(seq1, seq2)); 1338 } 1339 1340 /* These functions determine how the current flow behaves in respect of SACK 1341 * handling. SACK is negotiated with the peer, and therefore it can vary 1342 * between different flows. 1343 * 1344 * tcp_is_sack - SACK enabled 1345 * tcp_is_reno - No SACK 1346 */ 1347 static inline int tcp_is_sack(const struct tcp_sock *tp) 1348 { 1349 return likely(tp->rx_opt.sack_ok); 1350 } 1351 1352 static inline bool tcp_is_reno(const struct tcp_sock *tp) 1353 { 1354 return !tcp_is_sack(tp); 1355 } 1356 1357 static inline unsigned int tcp_left_out(const struct tcp_sock *tp) 1358 { 1359 return tp->sacked_out + tp->lost_out; 1360 } 1361 1362 /* This determines how many packets are "in the network" to the best 1363 * of our knowledge. In many cases it is conservative, but where 1364 * detailed information is available from the receiver (via SACK 1365 * blocks etc.) we can make more aggressive calculations. 1366 * 1367 * Use this for decisions involving congestion control, use just 1368 * tp->packets_out to determine if the send queue is empty or not. 1369 * 1370 * Read this equation as: 1371 * 1372 * "Packets sent once on transmission queue" MINUS 1373 * "Packets left network, but not honestly ACKed yet" PLUS 1374 * "Packets fast retransmitted" 1375 */ 1376 static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) 1377 { 1378 return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; 1379 } 1380 1381 #define TCP_INFINITE_SSTHRESH 0x7fffffff 1382 1383 static inline u32 tcp_snd_cwnd(const struct tcp_sock *tp) 1384 { 1385 return tp->snd_cwnd; 1386 } 1387 1388 static inline void tcp_snd_cwnd_set(struct tcp_sock *tp, u32 val) 1389 { 1390 WARN_ON_ONCE((int)val <= 0); 1391 tp->snd_cwnd = val; 1392 } 1393 1394 static inline bool tcp_in_slow_start(const struct tcp_sock *tp) 1395 { 1396 return tcp_snd_cwnd(tp) < tp->snd_ssthresh; 1397 } 1398 1399 static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) 1400 { 1401 return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; 1402 } 1403 1404 static inline bool tcp_in_cwnd_reduction(const struct sock *sk) 1405 { 1406 return (TCPF_CA_CWR | TCPF_CA_Recovery) & 1407 (1 << inet_csk(sk)->icsk_ca_state); 1408 } 1409 1410 /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. 1411 * The exception is cwnd reduction phase, when cwnd is decreasing towards 1412 * ssthresh. 1413 */ 1414 static inline __u32 tcp_current_ssthresh(const struct sock *sk) 1415 { 1416 const struct tcp_sock *tp = tcp_sk(sk); 1417 1418 if (tcp_in_cwnd_reduction(sk)) 1419 return tp->snd_ssthresh; 1420 else 1421 return max(tp->snd_ssthresh, 1422 ((tcp_snd_cwnd(tp) >> 1) + 1423 (tcp_snd_cwnd(tp) >> 2))); 1424 } 1425 1426 /* Use define here intentionally to get WARN_ON location shown at the caller */ 1427 #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) 1428 1429 void tcp_enter_cwr(struct sock *sk); 1430 __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); 1431 1432 /* The maximum number of MSS of available cwnd for which TSO defers 1433 * sending if not using sysctl_tcp_tso_win_divisor. 1434 */ 1435 static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) 1436 { 1437 return 3; 1438 } 1439 1440 /* Returns end sequence number of the receiver's advertised window */ 1441 static inline u32 tcp_wnd_end(const struct tcp_sock *tp) 1442 { 1443 return tp->snd_una + tp->snd_wnd; 1444 } 1445 1446 /* We follow the spirit of RFC2861 to validate cwnd but implement a more 1447 * flexible approach. The RFC suggests cwnd should not be raised unless 1448 * it was fully used previously. And that's exactly what we do in 1449 * congestion avoidance mode. But in slow start we allow cwnd to grow 1450 * as long as the application has used half the cwnd. 1451 * Example : 1452 * cwnd is 10 (IW10), but application sends 9 frames. 1453 * We allow cwnd to reach 18 when all frames are ACKed. 1454 * This check is safe because it's as aggressive as slow start which already 1455 * risks 100% overshoot. The advantage is that we discourage application to 1456 * either send more filler packets or data to artificially blow up the cwnd 1457 * usage, and allow application-limited process to probe bw more aggressively. 1458 */ 1459 static inline bool tcp_is_cwnd_limited(const struct sock *sk) 1460 { 1461 const struct tcp_sock *tp = tcp_sk(sk); 1462 1463 if (tp->is_cwnd_limited) 1464 return true; 1465 1466 /* If in slow start, ensure cwnd grows to twice what was ACKed. */ 1467 if (tcp_in_slow_start(tp)) 1468 return tcp_snd_cwnd(tp) < 2 * tp->max_packets_out; 1469 1470 return false; 1471 } 1472 1473 /* BBR congestion control needs pacing. 1474 * Same remark for SO_MAX_PACING_RATE. 1475 * sch_fq packet scheduler is efficiently handling pacing, 1476 * but is not always installed/used. 1477 * Return true if TCP stack should pace packets itself. 1478 */ 1479 static inline bool tcp_needs_internal_pacing(const struct sock *sk) 1480 { 1481 return smp_load_acquire(&sk->sk_pacing_status) == SK_PACING_NEEDED; 1482 } 1483 1484 /* Estimates in how many jiffies next packet for this flow can be sent. 1485 * Scheduling a retransmit timer too early would be silly. 1486 */ 1487 static inline unsigned long tcp_pacing_delay(const struct sock *sk) 1488 { 1489 s64 delay = tcp_sk(sk)->tcp_wstamp_ns - tcp_sk(sk)->tcp_clock_cache; 1490 1491 return delay > 0 ? nsecs_to_jiffies(delay) : 0; 1492 } 1493 1494 static inline void tcp_reset_xmit_timer(struct sock *sk, 1495 const int what, 1496 unsigned long when, 1497 bool pace_delay) 1498 { 1499 if (pace_delay) 1500 when += tcp_pacing_delay(sk); 1501 inet_csk_reset_xmit_timer(sk, what, when, 1502 tcp_rto_max(sk)); 1503 } 1504 1505 /* Something is really bad, we could not queue an additional packet, 1506 * because qdisc is full or receiver sent a 0 window, or we are paced. 1507 * We do not want to add fuel to the fire, or abort too early, 1508 * so make sure the timer we arm now is at least 200ms in the future, 1509 * regardless of current icsk_rto value (as it could be ~2ms) 1510 */ 1511 static inline unsigned long tcp_probe0_base(const struct sock *sk) 1512 { 1513 return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); 1514 } 1515 1516 /* Variant of inet_csk_rto_backoff() used for zero window probes */ 1517 static inline unsigned long tcp_probe0_when(const struct sock *sk, 1518 unsigned long max_when) 1519 { 1520 u8 backoff = min_t(u8, ilog2(TCP_RTO_MAX / TCP_RTO_MIN) + 1, 1521 inet_csk(sk)->icsk_backoff); 1522 u64 when = (u64)tcp_probe0_base(sk) << backoff; 1523 1524 return (unsigned long)min_t(u64, when, max_when); 1525 } 1526 1527 static inline void tcp_check_probe_timer(struct sock *sk) 1528 { 1529 if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) 1530 tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, 1531 tcp_probe0_base(sk), true); 1532 } 1533 1534 static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) 1535 { 1536 tp->snd_wl1 = seq; 1537 } 1538 1539 static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) 1540 { 1541 tp->snd_wl1 = seq; 1542 } 1543 1544 /* 1545 * Calculate(/check) TCP checksum 1546 */ 1547 static inline __sum16 tcp_v4_check(int len, __be32 saddr, 1548 __be32 daddr, __wsum base) 1549 { 1550 return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_TCP, base); 1551 } 1552 1553 static inline bool tcp_checksum_complete(struct sk_buff *skb) 1554 { 1555 return !skb_csum_unnecessary(skb) && 1556 __skb_checksum_complete(skb); 1557 } 1558 1559 bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb, 1560 enum skb_drop_reason *reason); 1561 1562 1563 int tcp_filter(struct sock *sk, struct sk_buff *skb); 1564 void tcp_set_state(struct sock *sk, int state); 1565 void tcp_done(struct sock *sk); 1566 int tcp_abort(struct sock *sk, int err); 1567 1568 static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) 1569 { 1570 rx_opt->dsack = 0; 1571 rx_opt->num_sacks = 0; 1572 } 1573 1574 void tcp_cwnd_restart(struct sock *sk, s32 delta); 1575 1576 static inline void tcp_slow_start_after_idle_check(struct sock *sk) 1577 { 1578 const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; 1579 struct tcp_sock *tp = tcp_sk(sk); 1580 s32 delta; 1581 1582 if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle) || 1583 tp->packets_out || ca_ops->cong_control) 1584 return; 1585 delta = tcp_jiffies32 - tp->lsndtime; 1586 if (delta > inet_csk(sk)->icsk_rto) 1587 tcp_cwnd_restart(sk, delta); 1588 } 1589 1590 /* Determine a window scaling and initial window to offer. */ 1591 void tcp_select_initial_window(const struct sock *sk, int __space, 1592 __u32 mss, __u32 *rcv_wnd, 1593 __u32 *window_clamp, int wscale_ok, 1594 __u8 *rcv_wscale, __u32 init_rcv_wnd); 1595 1596 static inline int __tcp_win_from_space(u8 scaling_ratio, int space) 1597 { 1598 s64 scaled_space = (s64)space * scaling_ratio; 1599 1600 return scaled_space >> TCP_RMEM_TO_WIN_SCALE; 1601 } 1602 1603 static inline int tcp_win_from_space(const struct sock *sk, int space) 1604 { 1605 return __tcp_win_from_space(tcp_sk(sk)->scaling_ratio, space); 1606 } 1607 1608 /* inverse of __tcp_win_from_space() */ 1609 static inline int __tcp_space_from_win(u8 scaling_ratio, int win) 1610 { 1611 u64 val = (u64)win << TCP_RMEM_TO_WIN_SCALE; 1612 1613 do_div(val, scaling_ratio); 1614 return val; 1615 } 1616 1617 static inline int tcp_space_from_win(const struct sock *sk, int win) 1618 { 1619 return __tcp_space_from_win(tcp_sk(sk)->scaling_ratio, win); 1620 } 1621 1622 /* Assume a 50% default for skb->len/skb->truesize ratio. 1623 * This may be adjusted later in tcp_measure_rcv_mss(). 1624 */ 1625 #define TCP_DEFAULT_SCALING_RATIO (1 << (TCP_RMEM_TO_WIN_SCALE - 1)) 1626 1627 static inline void tcp_scaling_ratio_init(struct sock *sk) 1628 { 1629 tcp_sk(sk)->scaling_ratio = TCP_DEFAULT_SCALING_RATIO; 1630 } 1631 1632 /* Note: caller must be prepared to deal with negative returns */ 1633 static inline int tcp_space(const struct sock *sk) 1634 { 1635 return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - 1636 READ_ONCE(sk->sk_backlog.len) - 1637 atomic_read(&sk->sk_rmem_alloc)); 1638 } 1639 1640 static inline int tcp_full_space(const struct sock *sk) 1641 { 1642 return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); 1643 } 1644 1645 static inline void __tcp_adjust_rcv_ssthresh(struct sock *sk, u32 new_ssthresh) 1646 { 1647 int unused_mem = sk_unused_reserved_mem(sk); 1648 struct tcp_sock *tp = tcp_sk(sk); 1649 1650 tp->rcv_ssthresh = min(tp->rcv_ssthresh, new_ssthresh); 1651 if (unused_mem) 1652 tp->rcv_ssthresh = max_t(u32, tp->rcv_ssthresh, 1653 tcp_win_from_space(sk, unused_mem)); 1654 } 1655 1656 static inline void tcp_adjust_rcv_ssthresh(struct sock *sk) 1657 { 1658 __tcp_adjust_rcv_ssthresh(sk, 4U * tcp_sk(sk)->advmss); 1659 } 1660 1661 void tcp_cleanup_rbuf(struct sock *sk, int copied); 1662 void __tcp_cleanup_rbuf(struct sock *sk, int copied); 1663 1664 1665 /* We provision sk_rcvbuf around 200% of sk_rcvlowat. 1666 * If 87.5 % (7/8) of the space has been consumed, we want to override 1667 * SO_RCVLOWAT constraint, since we are receiving skbs with too small 1668 * len/truesize ratio. 1669 */ 1670 static inline bool tcp_rmem_pressure(const struct sock *sk) 1671 { 1672 int rcvbuf, threshold; 1673 1674 if (tcp_under_memory_pressure(sk)) 1675 return true; 1676 1677 rcvbuf = READ_ONCE(sk->sk_rcvbuf); 1678 threshold = rcvbuf - (rcvbuf >> 3); 1679 1680 return atomic_read(&sk->sk_rmem_alloc) > threshold; 1681 } 1682 1683 static inline bool tcp_epollin_ready(const struct sock *sk, int target) 1684 { 1685 const struct tcp_sock *tp = tcp_sk(sk); 1686 int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); 1687 1688 if (avail <= 0) 1689 return false; 1690 1691 return (avail >= target) || tcp_rmem_pressure(sk) || 1692 (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss); 1693 } 1694 1695 extern void tcp_openreq_init_rwin(struct request_sock *req, 1696 const struct sock *sk_listener, 1697 const struct dst_entry *dst); 1698 1699 void tcp_enter_memory_pressure(struct sock *sk); 1700 void tcp_leave_memory_pressure(struct sock *sk); 1701 1702 static inline int keepalive_intvl_when(const struct tcp_sock *tp) 1703 { 1704 struct net *net = sock_net((struct sock *)tp); 1705 int val; 1706 1707 /* Paired with WRITE_ONCE() in tcp_sock_set_keepintvl() 1708 * and do_tcp_setsockopt(). 1709 */ 1710 val = READ_ONCE(tp->keepalive_intvl); 1711 1712 return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); 1713 } 1714 1715 static inline int keepalive_time_when(const struct tcp_sock *tp) 1716 { 1717 struct net *net = sock_net((struct sock *)tp); 1718 int val; 1719 1720 /* Paired with WRITE_ONCE() in tcp_sock_set_keepidle_locked() */ 1721 val = READ_ONCE(tp->keepalive_time); 1722 1723 return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); 1724 } 1725 1726 static inline int keepalive_probes(const struct tcp_sock *tp) 1727 { 1728 struct net *net = sock_net((struct sock *)tp); 1729 int val; 1730 1731 /* Paired with WRITE_ONCE() in tcp_sock_set_keepcnt() 1732 * and do_tcp_setsockopt(). 1733 */ 1734 val = READ_ONCE(tp->keepalive_probes); 1735 1736 return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes); 1737 } 1738 1739 static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) 1740 { 1741 const struct inet_connection_sock *icsk = &tp->inet_conn; 1742 1743 return min_t(u32, tcp_jiffies32 - icsk->icsk_ack.lrcvtime, 1744 tcp_jiffies32 - tp->rcv_tstamp); 1745 } 1746 1747 static inline int tcp_fin_time(const struct sock *sk) 1748 { 1749 int fin_timeout = tcp_sk(sk)->linger2 ? : 1750 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fin_timeout); 1751 const int rto = inet_csk(sk)->icsk_rto; 1752 1753 if (fin_timeout < (rto << 2) - (rto >> 1)) 1754 fin_timeout = (rto << 2) - (rto >> 1); 1755 1756 return fin_timeout; 1757 } 1758 1759 static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, 1760 int paws_win) 1761 { 1762 if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) 1763 return true; 1764 if (unlikely(!time_before32(ktime_get_seconds(), 1765 rx_opt->ts_recent_stamp + TCP_PAWS_WRAP))) 1766 return true; 1767 /* 1768 * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, 1769 * then following tcp messages have valid values. Ignore 0 value, 1770 * or else 'negative' tsval might forbid us to accept their packets. 1771 */ 1772 if (!rx_opt->ts_recent) 1773 return true; 1774 return false; 1775 } 1776 1777 static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, 1778 int rst) 1779 { 1780 if (tcp_paws_check(rx_opt, 0)) 1781 return false; 1782 1783 /* RST segments are not recommended to carry timestamp, 1784 and, if they do, it is recommended to ignore PAWS because 1785 "their cleanup function should take precedence over timestamps." 1786 Certainly, it is mistake. It is necessary to understand the reasons 1787 of this constraint to relax it: if peer reboots, clock may go 1788 out-of-sync and half-open connections will not be reset. 1789 Actually, the problem would be not existing if all 1790 the implementations followed draft about maintaining clock 1791 via reboots. Linux-2.2 DOES NOT! 1792 1793 However, we can relax time bounds for RST segments to MSL. 1794 */ 1795 if (rst && !time_before32(ktime_get_seconds(), 1796 rx_opt->ts_recent_stamp + TCP_PAWS_MSL)) 1797 return false; 1798 return true; 1799 } 1800 1801 bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, 1802 int mib_idx, u32 *last_oow_ack_time); 1803 1804 static inline void tcp_mib_init(struct net *net) 1805 { 1806 /* See RFC 2012 */ 1807 TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); 1808 TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); 1809 TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); 1810 TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); 1811 } 1812 1813 /* from STCP */ 1814 static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) 1815 { 1816 tp->retransmit_skb_hint = NULL; 1817 } 1818 1819 #define tcp_md5_addr tcp_ao_addr 1820 1821 /* - key database */ 1822 struct tcp_md5sig_key { 1823 struct hlist_node node; 1824 u8 keylen; 1825 u8 family; /* AF_INET or AF_INET6 */ 1826 u8 prefixlen; 1827 u8 flags; 1828 union tcp_md5_addr addr; 1829 int l3index; /* set if key added with L3 scope */ 1830 u8 key[TCP_MD5SIG_MAXKEYLEN]; 1831 struct rcu_head rcu; 1832 }; 1833 1834 /* - sock block */ 1835 struct tcp_md5sig_info { 1836 struct hlist_head head; 1837 struct rcu_head rcu; 1838 }; 1839 1840 /* - pseudo header */ 1841 struct tcp4_pseudohdr { 1842 __be32 saddr; 1843 __be32 daddr; 1844 __u8 pad; 1845 __u8 protocol; 1846 __be16 len; 1847 }; 1848 1849 struct tcp6_pseudohdr { 1850 struct in6_addr saddr; 1851 struct in6_addr daddr; 1852 __be32 len; 1853 __be32 protocol; /* including padding */ 1854 }; 1855 1856 union tcp_md5sum_block { 1857 struct tcp4_pseudohdr ip4; 1858 #if IS_ENABLED(CONFIG_IPV6) 1859 struct tcp6_pseudohdr ip6; 1860 #endif 1861 }; 1862 1863 /* 1864 * struct tcp_sigpool - per-CPU pool of ahash_requests 1865 * @scratch: per-CPU temporary area, that can be used between 1866 * tcp_sigpool_start() and tcp_sigpool_end() to perform 1867 * crypto request 1868 * @req: pre-allocated ahash request 1869 */ 1870 struct tcp_sigpool { 1871 void *scratch; 1872 struct ahash_request *req; 1873 }; 1874 1875 int tcp_sigpool_alloc_ahash(const char *alg, size_t scratch_size); 1876 void tcp_sigpool_get(unsigned int id); 1877 void tcp_sigpool_release(unsigned int id); 1878 int tcp_sigpool_hash_skb_data(struct tcp_sigpool *hp, 1879 const struct sk_buff *skb, 1880 unsigned int header_len); 1881 1882 /** 1883 * tcp_sigpool_start - disable bh and start using tcp_sigpool_ahash 1884 * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash() 1885 * @c: returned tcp_sigpool for usage (uninitialized on failure) 1886 * 1887 * Returns: 0 on success, error otherwise. 1888 */ 1889 int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c); 1890 /** 1891 * tcp_sigpool_end - enable bh and stop using tcp_sigpool 1892 * @c: tcp_sigpool context that was returned by tcp_sigpool_start() 1893 */ 1894 void tcp_sigpool_end(struct tcp_sigpool *c); 1895 size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len); 1896 /* - functions */ 1897 int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, 1898 const struct sock *sk, const struct sk_buff *skb); 1899 int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, 1900 int family, u8 prefixlen, int l3index, u8 flags, 1901 const u8 *newkey, u8 newkeylen); 1902 int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr, 1903 int family, u8 prefixlen, int l3index, 1904 struct tcp_md5sig_key *key); 1905 1906 int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, 1907 int family, u8 prefixlen, int l3index, u8 flags); 1908 void tcp_clear_md5_list(struct sock *sk); 1909 struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, 1910 const struct sock *addr_sk); 1911 1912 #ifdef CONFIG_TCP_MD5SIG 1913 struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, 1914 const union tcp_md5_addr *addr, 1915 int family, bool any_l3index); 1916 static inline struct tcp_md5sig_key * 1917 tcp_md5_do_lookup(const struct sock *sk, int l3index, 1918 const union tcp_md5_addr *addr, int family) 1919 { 1920 if (!static_branch_unlikely(&tcp_md5_needed.key)) 1921 return NULL; 1922 return __tcp_md5_do_lookup(sk, l3index, addr, family, false); 1923 } 1924 1925 static inline struct tcp_md5sig_key * 1926 tcp_md5_do_lookup_any_l3index(const struct sock *sk, 1927 const union tcp_md5_addr *addr, int family) 1928 { 1929 if (!static_branch_unlikely(&tcp_md5_needed.key)) 1930 return NULL; 1931 return __tcp_md5_do_lookup(sk, 0, addr, family, true); 1932 } 1933 1934 #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) 1935 #else 1936 static inline struct tcp_md5sig_key * 1937 tcp_md5_do_lookup(const struct sock *sk, int l3index, 1938 const union tcp_md5_addr *addr, int family) 1939 { 1940 return NULL; 1941 } 1942 1943 static inline struct tcp_md5sig_key * 1944 tcp_md5_do_lookup_any_l3index(const struct sock *sk, 1945 const union tcp_md5_addr *addr, int family) 1946 { 1947 return NULL; 1948 } 1949 1950 #define tcp_twsk_md5_key(twsk) NULL 1951 #endif 1952 1953 int tcp_md5_alloc_sigpool(void); 1954 void tcp_md5_release_sigpool(void); 1955 void tcp_md5_add_sigpool(void); 1956 extern int tcp_md5_sigpool_id; 1957 1958 int tcp_md5_hash_key(struct tcp_sigpool *hp, 1959 const struct tcp_md5sig_key *key); 1960 1961 /* From tcp_fastopen.c */ 1962 void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, 1963 struct tcp_fastopen_cookie *cookie); 1964 void tcp_fastopen_cache_set(struct sock *sk, u16 mss, 1965 struct tcp_fastopen_cookie *cookie, bool syn_lost, 1966 u16 try_exp); 1967 struct tcp_fastopen_request { 1968 /* Fast Open cookie. Size 0 means a cookie request */ 1969 struct tcp_fastopen_cookie cookie; 1970 struct msghdr *data; /* data in MSG_FASTOPEN */ 1971 size_t size; 1972 int copied; /* queued in tcp_connect() */ 1973 struct ubuf_info *uarg; 1974 }; 1975 void tcp_free_fastopen_req(struct tcp_sock *tp); 1976 void tcp_fastopen_destroy_cipher(struct sock *sk); 1977 void tcp_fastopen_ctx_destroy(struct net *net); 1978 int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, 1979 void *primary_key, void *backup_key); 1980 int tcp_fastopen_get_cipher(struct net *net, struct inet_connection_sock *icsk, 1981 u64 *key); 1982 void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); 1983 struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, 1984 struct request_sock *req, 1985 struct tcp_fastopen_cookie *foc, 1986 const struct dst_entry *dst); 1987 void tcp_fastopen_init_key_once(struct net *net); 1988 bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, 1989 struct tcp_fastopen_cookie *cookie); 1990 bool tcp_fastopen_defer_connect(struct sock *sk, int *err); 1991 #define TCP_FASTOPEN_KEY_LENGTH sizeof(siphash_key_t) 1992 #define TCP_FASTOPEN_KEY_MAX 2 1993 #define TCP_FASTOPEN_KEY_BUF_LENGTH \ 1994 (TCP_FASTOPEN_KEY_LENGTH * TCP_FASTOPEN_KEY_MAX) 1995 1996 /* Fastopen key context */ 1997 struct tcp_fastopen_context { 1998 siphash_key_t key[TCP_FASTOPEN_KEY_MAX]; 1999 int num; 2000 struct rcu_head rcu; 2001 }; 2002 2003 void tcp_fastopen_active_disable(struct sock *sk); 2004 bool tcp_fastopen_active_should_disable(struct sock *sk); 2005 void tcp_fastopen_active_disable_ofo_check(struct sock *sk); 2006 void tcp_fastopen_active_detect_blackhole(struct sock *sk, bool expired); 2007 2008 /* Caller needs to wrap with rcu_read_(un)lock() */ 2009 static inline 2010 struct tcp_fastopen_context *tcp_fastopen_get_ctx(const struct sock *sk) 2011 { 2012 struct tcp_fastopen_context *ctx; 2013 2014 ctx = rcu_dereference(inet_csk(sk)->icsk_accept_queue.fastopenq.ctx); 2015 if (!ctx) 2016 ctx = rcu_dereference(sock_net(sk)->ipv4.tcp_fastopen_ctx); 2017 return ctx; 2018 } 2019 2020 static inline 2021 bool tcp_fastopen_cookie_match(const struct tcp_fastopen_cookie *foc, 2022 const struct tcp_fastopen_cookie *orig) 2023 { 2024 if (orig->len == TCP_FASTOPEN_COOKIE_SIZE && 2025 orig->len == foc->len && 2026 !memcmp(orig->val, foc->val, foc->len)) 2027 return true; 2028 return false; 2029 } 2030 2031 static inline 2032 int tcp_fastopen_context_len(const struct tcp_fastopen_context *ctx) 2033 { 2034 return ctx->num; 2035 } 2036 2037 /* Latencies incurred by various limits for a sender. They are 2038 * chronograph-like stats that are mutually exclusive. 2039 */ 2040 enum tcp_chrono { 2041 TCP_CHRONO_UNSPEC, 2042 TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ 2043 TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ 2044 TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ 2045 __TCP_CHRONO_MAX, 2046 }; 2047 2048 void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); 2049 void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); 2050 2051 /* This helper is needed, because skb->tcp_tsorted_anchor uses 2052 * the same memory storage than skb->destructor/_skb_refdst 2053 */ 2054 static inline void tcp_skb_tsorted_anchor_cleanup(struct sk_buff *skb) 2055 { 2056 skb->destructor = NULL; 2057 skb->_skb_refdst = 0UL; 2058 } 2059 2060 #define tcp_skb_tsorted_save(skb) { \ 2061 unsigned long _save = skb->_skb_refdst; \ 2062 skb->_skb_refdst = 0UL; 2063 2064 #define tcp_skb_tsorted_restore(skb) \ 2065 skb->_skb_refdst = _save; \ 2066 } 2067 2068 void tcp_write_queue_purge(struct sock *sk); 2069 2070 static inline struct sk_buff *tcp_rtx_queue_head(const struct sock *sk) 2071 { 2072 return skb_rb_first(&sk->tcp_rtx_queue); 2073 } 2074 2075 static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) 2076 { 2077 return skb_rb_last(&sk->tcp_rtx_queue); 2078 } 2079 2080 static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) 2081 { 2082 return skb_peek_tail(&sk->sk_write_queue); 2083 } 2084 2085 #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ 2086 skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) 2087 2088 static inline struct sk_buff *tcp_send_head(const struct sock *sk) 2089 { 2090 return skb_peek(&sk->sk_write_queue); 2091 } 2092 2093 static inline bool tcp_skb_is_last(const struct sock *sk, 2094 const struct sk_buff *skb) 2095 { 2096 return skb_queue_is_last(&sk->sk_write_queue, skb); 2097 } 2098 2099 /** 2100 * tcp_write_queue_empty - test if any payload (or FIN) is available in write queue 2101 * @sk: socket 2102 * 2103 * Since the write queue can have a temporary empty skb in it, 2104 * we must not use "return skb_queue_empty(&sk->sk_write_queue)" 2105 */ 2106 static inline bool tcp_write_queue_empty(const struct sock *sk) 2107 { 2108 const struct tcp_sock *tp = tcp_sk(sk); 2109 2110 return tp->write_seq == tp->snd_nxt; 2111 } 2112 2113 static inline bool tcp_rtx_queue_empty(const struct sock *sk) 2114 { 2115 return RB_EMPTY_ROOT(&sk->tcp_rtx_queue); 2116 } 2117 2118 static inline bool tcp_rtx_and_write_queues_empty(const struct sock *sk) 2119 { 2120 return tcp_rtx_queue_empty(sk) && tcp_write_queue_empty(sk); 2121 } 2122 2123 static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) 2124 { 2125 __skb_queue_tail(&sk->sk_write_queue, skb); 2126 2127 /* Queue it, remembering where we must start sending. */ 2128 if (sk->sk_write_queue.next == skb) 2129 tcp_chrono_start(sk, TCP_CHRONO_BUSY); 2130 } 2131 2132 /* Insert new before skb on the write queue of sk. */ 2133 static inline void tcp_insert_write_queue_before(struct sk_buff *new, 2134 struct sk_buff *skb, 2135 struct sock *sk) 2136 { 2137 __skb_queue_before(&sk->sk_write_queue, skb, new); 2138 } 2139 2140 static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) 2141 { 2142 tcp_skb_tsorted_anchor_cleanup(skb); 2143 __skb_unlink(skb, &sk->sk_write_queue); 2144 } 2145 2146 void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb); 2147 2148 static inline void tcp_rtx_queue_unlink(struct sk_buff *skb, struct sock *sk) 2149 { 2150 tcp_skb_tsorted_anchor_cleanup(skb); 2151 rb_erase(&skb->rbnode, &sk->tcp_rtx_queue); 2152 } 2153 2154 static inline void tcp_rtx_queue_unlink_and_free(struct sk_buff *skb, struct sock *sk) 2155 { 2156 list_del(&skb->tcp_tsorted_anchor); 2157 tcp_rtx_queue_unlink(skb, sk); 2158 tcp_wmem_free_skb(sk, skb); 2159 } 2160 2161 static inline void tcp_write_collapse_fence(struct sock *sk) 2162 { 2163 struct sk_buff *skb = tcp_write_queue_tail(sk); 2164 2165 if (skb) 2166 TCP_SKB_CB(skb)->eor = 1; 2167 } 2168 2169 static inline void tcp_push_pending_frames(struct sock *sk) 2170 { 2171 if (tcp_send_head(sk)) { 2172 struct tcp_sock *tp = tcp_sk(sk); 2173 2174 __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); 2175 } 2176 } 2177 2178 /* Start sequence of the skb just after the highest skb with SACKed 2179 * bit, valid only if sacked_out > 0 or when the caller has ensured 2180 * validity by itself. 2181 */ 2182 static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) 2183 { 2184 if (!tp->sacked_out) 2185 return tp->snd_una; 2186 2187 if (tp->highest_sack == NULL) 2188 return tp->snd_nxt; 2189 2190 return TCP_SKB_CB(tp->highest_sack)->seq; 2191 } 2192 2193 static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) 2194 { 2195 tcp_sk(sk)->highest_sack = skb_rb_next(skb); 2196 } 2197 2198 static inline struct sk_buff *tcp_highest_sack(struct sock *sk) 2199 { 2200 return tcp_sk(sk)->highest_sack; 2201 } 2202 2203 static inline void tcp_highest_sack_reset(struct sock *sk) 2204 { 2205 tcp_sk(sk)->highest_sack = tcp_rtx_queue_head(sk); 2206 } 2207 2208 /* Called when old skb is about to be deleted and replaced by new skb */ 2209 static inline void tcp_highest_sack_replace(struct sock *sk, 2210 struct sk_buff *old, 2211 struct sk_buff *new) 2212 { 2213 if (old == tcp_highest_sack(sk)) 2214 tcp_sk(sk)->highest_sack = new; 2215 } 2216 2217 /* This helper checks if socket has IP_TRANSPARENT set */ 2218 static inline bool inet_sk_transparent(const struct sock *sk) 2219 { 2220 switch (sk->sk_state) { 2221 case TCP_TIME_WAIT: 2222 return inet_twsk(sk)->tw_transparent; 2223 case TCP_NEW_SYN_RECV: 2224 return inet_rsk(inet_reqsk(sk))->no_srccheck; 2225 } 2226 return inet_test_bit(TRANSPARENT, sk); 2227 } 2228 2229 /* Determines whether this is a thin stream (which may suffer from 2230 * increased latency). Used to trigger latency-reducing mechanisms. 2231 */ 2232 static inline bool tcp_stream_is_thin(struct tcp_sock *tp) 2233 { 2234 return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); 2235 } 2236 2237 /* /proc */ 2238 enum tcp_seq_states { 2239 TCP_SEQ_STATE_LISTENING, 2240 TCP_SEQ_STATE_ESTABLISHED, 2241 }; 2242 2243 void *tcp_seq_start(struct seq_file *seq, loff_t *pos); 2244 void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos); 2245 void tcp_seq_stop(struct seq_file *seq, void *v); 2246 2247 struct tcp_seq_afinfo { 2248 sa_family_t family; 2249 }; 2250 2251 struct tcp_iter_state { 2252 struct seq_net_private p; 2253 enum tcp_seq_states state; 2254 struct sock *syn_wait_sk; 2255 int bucket, offset, sbucket, num; 2256 loff_t last_pos; 2257 }; 2258 2259 extern struct request_sock_ops tcp_request_sock_ops; 2260 extern struct request_sock_ops tcp6_request_sock_ops; 2261 2262 void tcp_v4_destroy_sock(struct sock *sk); 2263 2264 struct sk_buff *tcp_gso_segment(struct sk_buff *skb, 2265 netdev_features_t features); 2266 struct tcphdr *tcp_gro_pull_header(struct sk_buff *skb); 2267 struct sk_buff *tcp_gro_lookup(struct list_head *head, struct tcphdr *th); 2268 struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb, 2269 struct tcphdr *th); 2270 INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *skb, int thoff)); 2271 INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)); 2272 INDIRECT_CALLABLE_DECLARE(int tcp6_gro_complete(struct sk_buff *skb, int thoff)); 2273 INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)); 2274 #ifdef CONFIG_INET 2275 void tcp_gro_complete(struct sk_buff *skb); 2276 #else 2277 static inline void tcp_gro_complete(struct sk_buff *skb) { } 2278 #endif 2279 2280 void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); 2281 2282 static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) 2283 { 2284 struct net *net = sock_net((struct sock *)tp); 2285 u32 val; 2286 2287 val = READ_ONCE(tp->notsent_lowat); 2288 2289 return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); 2290 } 2291 2292 bool tcp_stream_memory_free(const struct sock *sk, int wake); 2293 2294 #ifdef CONFIG_PROC_FS 2295 int tcp4_proc_init(void); 2296 void tcp4_proc_exit(void); 2297 #endif 2298 2299 int tcp_rtx_synack(const struct sock *sk, struct request_sock *req); 2300 int tcp_conn_request(struct request_sock_ops *rsk_ops, 2301 const struct tcp_request_sock_ops *af_ops, 2302 struct sock *sk, struct sk_buff *skb); 2303 2304 /* TCP af-specific functions */ 2305 struct tcp_sock_af_ops { 2306 #ifdef CONFIG_TCP_MD5SIG 2307 struct tcp_md5sig_key *(*md5_lookup) (const struct sock *sk, 2308 const struct sock *addr_sk); 2309 int (*calc_md5_hash)(char *location, 2310 const struct tcp_md5sig_key *md5, 2311 const struct sock *sk, 2312 const struct sk_buff *skb); 2313 int (*md5_parse)(struct sock *sk, 2314 int optname, 2315 sockptr_t optval, 2316 int optlen); 2317 #endif 2318 #ifdef CONFIG_TCP_AO 2319 int (*ao_parse)(struct sock *sk, int optname, sockptr_t optval, int optlen); 2320 struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, 2321 struct sock *addr_sk, 2322 int sndid, int rcvid); 2323 int (*ao_calc_key_sk)(struct tcp_ao_key *mkt, u8 *key, 2324 const struct sock *sk, 2325 __be32 sisn, __be32 disn, bool send); 2326 int (*calc_ao_hash)(char *location, struct tcp_ao_key *ao, 2327 const struct sock *sk, const struct sk_buff *skb, 2328 const u8 *tkey, int hash_offset, u32 sne); 2329 #endif 2330 }; 2331 2332 struct tcp_request_sock_ops { 2333 u16 mss_clamp; 2334 #ifdef CONFIG_TCP_MD5SIG 2335 struct tcp_md5sig_key *(*req_md5_lookup)(const struct sock *sk, 2336 const struct sock *addr_sk); 2337 int (*calc_md5_hash) (char *location, 2338 const struct tcp_md5sig_key *md5, 2339 const struct sock *sk, 2340 const struct sk_buff *skb); 2341 #endif 2342 #ifdef CONFIG_TCP_AO 2343 struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, 2344 struct request_sock *req, 2345 int sndid, int rcvid); 2346 int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk); 2347 int (*ao_synack_hash)(char *ao_hash, struct tcp_ao_key *mkt, 2348 struct request_sock *req, const struct sk_buff *skb, 2349 int hash_offset, u32 sne); 2350 #endif 2351 #ifdef CONFIG_SYN_COOKIES 2352 __u32 (*cookie_init_seq)(const struct sk_buff *skb, 2353 __u16 *mss); 2354 #endif 2355 struct dst_entry *(*route_req)(const struct sock *sk, 2356 struct sk_buff *skb, 2357 struct flowi *fl, 2358 struct request_sock *req, 2359 u32 tw_isn); 2360 u32 (*init_seq)(const struct sk_buff *skb); 2361 u32 (*init_ts_off)(const struct net *net, const struct sk_buff *skb); 2362 int (*send_synack)(const struct sock *sk, struct dst_entry *dst, 2363 struct flowi *fl, struct request_sock *req, 2364 struct tcp_fastopen_cookie *foc, 2365 enum tcp_synack_type synack_type, 2366 struct sk_buff *syn_skb); 2367 }; 2368 2369 extern const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops; 2370 #if IS_ENABLED(CONFIG_IPV6) 2371 extern const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops; 2372 #endif 2373 2374 #ifdef CONFIG_SYN_COOKIES 2375 static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, 2376 const struct sock *sk, struct sk_buff *skb, 2377 __u16 *mss) 2378 { 2379 tcp_synq_overflow(sk); 2380 __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); 2381 return ops->cookie_init_seq(skb, mss); 2382 } 2383 #else 2384 static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, 2385 const struct sock *sk, struct sk_buff *skb, 2386 __u16 *mss) 2387 { 2388 return 0; 2389 } 2390 #endif 2391 2392 struct tcp_key { 2393 union { 2394 struct { 2395 struct tcp_ao_key *ao_key; 2396 char *traffic_key; 2397 u32 sne; 2398 u8 rcv_next; 2399 }; 2400 struct tcp_md5sig_key *md5_key; 2401 }; 2402 enum { 2403 TCP_KEY_NONE = 0, 2404 TCP_KEY_MD5, 2405 TCP_KEY_AO, 2406 } type; 2407 }; 2408 2409 static inline void tcp_get_current_key(const struct sock *sk, 2410 struct tcp_key *out) 2411 { 2412 #if defined(CONFIG_TCP_AO) || defined(CONFIG_TCP_MD5SIG) 2413 const struct tcp_sock *tp = tcp_sk(sk); 2414 #endif 2415 2416 #ifdef CONFIG_TCP_AO 2417 if (static_branch_unlikely(&tcp_ao_needed.key)) { 2418 struct tcp_ao_info *ao; 2419 2420 ao = rcu_dereference_protected(tp->ao_info, 2421 lockdep_sock_is_held(sk)); 2422 if (ao) { 2423 out->ao_key = READ_ONCE(ao->current_key); 2424 out->type = TCP_KEY_AO; 2425 return; 2426 } 2427 } 2428 #endif 2429 #ifdef CONFIG_TCP_MD5SIG 2430 if (static_branch_unlikely(&tcp_md5_needed.key) && 2431 rcu_access_pointer(tp->md5sig_info)) { 2432 out->md5_key = tp->af_specific->md5_lookup(sk, sk); 2433 if (out->md5_key) { 2434 out->type = TCP_KEY_MD5; 2435 return; 2436 } 2437 } 2438 #endif 2439 out->type = TCP_KEY_NONE; 2440 } 2441 2442 static inline bool tcp_key_is_md5(const struct tcp_key *key) 2443 { 2444 if (static_branch_tcp_md5()) 2445 return key->type == TCP_KEY_MD5; 2446 return false; 2447 } 2448 2449 static inline bool tcp_key_is_ao(const struct tcp_key *key) 2450 { 2451 if (static_branch_tcp_ao()) 2452 return key->type == TCP_KEY_AO; 2453 return false; 2454 } 2455 2456 int tcpv4_offload_init(void); 2457 2458 void tcp_v4_init(void); 2459 void tcp_init(void); 2460 2461 /* tcp_recovery.c */ 2462 void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb); 2463 void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced); 2464 extern s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, 2465 u32 reo_wnd); 2466 extern bool tcp_rack_mark_lost(struct sock *sk); 2467 extern void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, 2468 u64 xmit_time); 2469 extern void tcp_rack_reo_timeout(struct sock *sk); 2470 extern void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs); 2471 2472 /* tcp_plb.c */ 2473 2474 /* 2475 * Scaling factor for fractions in PLB. For example, tcp_plb_update_state 2476 * expects cong_ratio which represents fraction of traffic that experienced 2477 * congestion over a single RTT. In order to avoid floating point operations, 2478 * this fraction should be mapped to (1 << TCP_PLB_SCALE) and passed in. 2479 */ 2480 #define TCP_PLB_SCALE 8 2481 2482 /* State for PLB (Protective Load Balancing) for a single TCP connection. */ 2483 struct tcp_plb_state { 2484 u8 consec_cong_rounds:5, /* consecutive congested rounds */ 2485 unused:3; 2486 u32 pause_until; /* jiffies32 when PLB can resume rerouting */ 2487 }; 2488 2489 static inline void tcp_plb_init(const struct sock *sk, 2490 struct tcp_plb_state *plb) 2491 { 2492 plb->consec_cong_rounds = 0; 2493 plb->pause_until = 0; 2494 } 2495 void tcp_plb_update_state(const struct sock *sk, struct tcp_plb_state *plb, 2496 const int cong_ratio); 2497 void tcp_plb_check_rehash(struct sock *sk, struct tcp_plb_state *plb); 2498 void tcp_plb_update_state_upon_rto(struct sock *sk, struct tcp_plb_state *plb); 2499 2500 static inline void tcp_warn_once(const struct sock *sk, bool cond, const char *str) 2501 { 2502 WARN_ONCE(cond, 2503 "%scwn:%u out:%u sacked:%u lost:%u retrans:%u tlp_high_seq:%u sk_state:%u ca_state:%u advmss:%u mss_cache:%u pmtu:%u\n", 2504 str, 2505 tcp_snd_cwnd(tcp_sk(sk)), 2506 tcp_sk(sk)->packets_out, tcp_sk(sk)->sacked_out, 2507 tcp_sk(sk)->lost_out, tcp_sk(sk)->retrans_out, 2508 tcp_sk(sk)->tlp_high_seq, sk->sk_state, 2509 inet_csk(sk)->icsk_ca_state, 2510 tcp_sk(sk)->advmss, tcp_sk(sk)->mss_cache, 2511 inet_csk(sk)->icsk_pmtu_cookie); 2512 } 2513 2514 /* At how many usecs into the future should the RTO fire? */ 2515 static inline s64 tcp_rto_delta_us(const struct sock *sk) 2516 { 2517 const struct sk_buff *skb = tcp_rtx_queue_head(sk); 2518 u32 rto = inet_csk(sk)->icsk_rto; 2519 2520 if (likely(skb)) { 2521 u64 rto_time_stamp_us = tcp_skb_timestamp_us(skb) + jiffies_to_usecs(rto); 2522 2523 return rto_time_stamp_us - tcp_sk(sk)->tcp_mstamp; 2524 } else { 2525 tcp_warn_once(sk, 1, "rtx queue empty: "); 2526 return jiffies_to_usecs(rto); 2527 } 2528 2529 } 2530 2531 /* 2532 * Save and compile IPv4 options, return a pointer to it 2533 */ 2534 static inline struct ip_options_rcu *tcp_v4_save_options(struct net *net, 2535 struct sk_buff *skb) 2536 { 2537 const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; 2538 struct ip_options_rcu *dopt = NULL; 2539 2540 if (opt->optlen) { 2541 int opt_size = sizeof(*dopt) + opt->optlen; 2542 2543 dopt = kmalloc(opt_size, GFP_ATOMIC); 2544 if (dopt && __ip_options_echo(net, &dopt->opt, skb, opt)) { 2545 kfree(dopt); 2546 dopt = NULL; 2547 } 2548 } 2549 return dopt; 2550 } 2551 2552 /* locally generated TCP pure ACKs have skb->truesize == 2 2553 * (check tcp_send_ack() in net/ipv4/tcp_output.c ) 2554 * This is much faster than dissecting the packet to find out. 2555 * (Think of GRE encapsulations, IPv4, IPv6, ...) 2556 */ 2557 static inline bool skb_is_tcp_pure_ack(const struct sk_buff *skb) 2558 { 2559 return skb->truesize == 2; 2560 } 2561 2562 static inline void skb_set_tcp_pure_ack(struct sk_buff *skb) 2563 { 2564 skb->truesize = 2; 2565 } 2566 2567 static inline int tcp_inq(struct sock *sk) 2568 { 2569 struct tcp_sock *tp = tcp_sk(sk); 2570 int answ; 2571 2572 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { 2573 answ = 0; 2574 } else if (sock_flag(sk, SOCK_URGINLINE) || 2575 !tp->urg_data || 2576 before(tp->urg_seq, tp->copied_seq) || 2577 !before(tp->urg_seq, tp->rcv_nxt)) { 2578 2579 answ = tp->rcv_nxt - tp->copied_seq; 2580 2581 /* Subtract 1, if FIN was received */ 2582 if (answ && sock_flag(sk, SOCK_DONE)) 2583 answ--; 2584 } else { 2585 answ = tp->urg_seq - tp->copied_seq; 2586 } 2587 2588 return answ; 2589 } 2590 2591 int tcp_peek_len(struct socket *sock); 2592 2593 static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) 2594 { 2595 u16 segs_in; 2596 2597 segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); 2598 2599 /* We update these fields while other threads might 2600 * read them from tcp_get_info() 2601 */ 2602 WRITE_ONCE(tp->segs_in, tp->segs_in + segs_in); 2603 if (skb->len > tcp_hdrlen(skb)) 2604 WRITE_ONCE(tp->data_segs_in, tp->data_segs_in + segs_in); 2605 } 2606 2607 /* 2608 * TCP listen path runs lockless. 2609 * We forced "struct sock" to be const qualified to make sure 2610 * we don't modify one of its field by mistake. 2611 * Here, we increment sk_drops which is an atomic_t, so we can safely 2612 * make sock writable again. 2613 */ 2614 static inline void tcp_listendrop(const struct sock *sk) 2615 { 2616 atomic_inc(&((struct sock *)sk)->sk_drops); 2617 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); 2618 } 2619 2620 enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer); 2621 2622 /* 2623 * Interface for adding Upper Level Protocols over TCP 2624 */ 2625 2626 #define TCP_ULP_NAME_MAX 16 2627 #define TCP_ULP_MAX 128 2628 #define TCP_ULP_BUF_MAX (TCP_ULP_NAME_MAX*TCP_ULP_MAX) 2629 2630 struct tcp_ulp_ops { 2631 struct list_head list; 2632 2633 /* initialize ulp */ 2634 int (*init)(struct sock *sk); 2635 /* update ulp */ 2636 void (*update)(struct sock *sk, struct proto *p, 2637 void (*write_space)(struct sock *sk)); 2638 /* cleanup ulp */ 2639 void (*release)(struct sock *sk); 2640 /* diagnostic */ 2641 int (*get_info)(struct sock *sk, struct sk_buff *skb, bool net_admin); 2642 size_t (*get_info_size)(const struct sock *sk, bool net_admin); 2643 /* clone ulp */ 2644 void (*clone)(const struct request_sock *req, struct sock *newsk, 2645 const gfp_t priority); 2646 2647 char name[TCP_ULP_NAME_MAX]; 2648 struct module *owner; 2649 }; 2650 int tcp_register_ulp(struct tcp_ulp_ops *type); 2651 void tcp_unregister_ulp(struct tcp_ulp_ops *type); 2652 int tcp_set_ulp(struct sock *sk, const char *name); 2653 void tcp_get_available_ulp(char *buf, size_t len); 2654 void tcp_cleanup_ulp(struct sock *sk); 2655 void tcp_update_ulp(struct sock *sk, struct proto *p, 2656 void (*write_space)(struct sock *sk)); 2657 2658 #define MODULE_ALIAS_TCP_ULP(name) \ 2659 __MODULE_INFO(alias, alias_userspace, name); \ 2660 __MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name) 2661 2662 #ifdef CONFIG_NET_SOCK_MSG 2663 struct sk_msg; 2664 struct sk_psock; 2665 2666 #ifdef CONFIG_BPF_SYSCALL 2667 int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore); 2668 void tcp_bpf_clone(const struct sock *sk, struct sock *newsk); 2669 #ifdef CONFIG_BPF_STREAM_PARSER 2670 struct strparser; 2671 int tcp_bpf_strp_read_sock(struct strparser *strp, read_descriptor_t *desc, 2672 sk_read_actor_t recv_actor); 2673 #endif /* CONFIG_BPF_STREAM_PARSER */ 2674 #endif /* CONFIG_BPF_SYSCALL */ 2675 2676 #ifdef CONFIG_INET 2677 void tcp_eat_skb(struct sock *sk, struct sk_buff *skb); 2678 #else 2679 static inline void tcp_eat_skb(struct sock *sk, struct sk_buff *skb) 2680 { 2681 } 2682 #endif 2683 2684 int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress, 2685 struct sk_msg *msg, u32 bytes, int flags); 2686 #endif /* CONFIG_NET_SOCK_MSG */ 2687 2688 #if !defined(CONFIG_BPF_SYSCALL) || !defined(CONFIG_NET_SOCK_MSG) 2689 static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk) 2690 { 2691 } 2692 #endif 2693 2694 #ifdef CONFIG_CGROUP_BPF 2695 static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, 2696 struct sk_buff *skb, 2697 unsigned int end_offset) 2698 { 2699 skops->skb = skb; 2700 skops->skb_data_end = skb->data + end_offset; 2701 } 2702 #else 2703 static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, 2704 struct sk_buff *skb, 2705 unsigned int end_offset) 2706 { 2707 } 2708 #endif 2709 2710 /* Call BPF_SOCK_OPS program that returns an int. If the return value 2711 * is < 0, then the BPF op failed (for example if the loaded BPF 2712 * program does not support the chosen operation or there is no BPF 2713 * program loaded). 2714 */ 2715 #ifdef CONFIG_BPF 2716 static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) 2717 { 2718 struct bpf_sock_ops_kern sock_ops; 2719 int ret; 2720 2721 memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); 2722 if (sk_fullsock(sk)) { 2723 sock_ops.is_fullsock = 1; 2724 sock_ops.is_locked_tcp_sock = 1; 2725 sock_owned_by_me(sk); 2726 } 2727 2728 sock_ops.sk = sk; 2729 sock_ops.op = op; 2730 if (nargs > 0) 2731 memcpy(sock_ops.args, args, nargs * sizeof(*args)); 2732 2733 ret = BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); 2734 if (ret == 0) 2735 ret = sock_ops.reply; 2736 else 2737 ret = -1; 2738 return ret; 2739 } 2740 2741 static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) 2742 { 2743 u32 args[2] = {arg1, arg2}; 2744 2745 return tcp_call_bpf(sk, op, 2, args); 2746 } 2747 2748 static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, 2749 u32 arg3) 2750 { 2751 u32 args[3] = {arg1, arg2, arg3}; 2752 2753 return tcp_call_bpf(sk, op, 3, args); 2754 } 2755 2756 #else 2757 static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) 2758 { 2759 return -EPERM; 2760 } 2761 2762 static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) 2763 { 2764 return -EPERM; 2765 } 2766 2767 static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, 2768 u32 arg3) 2769 { 2770 return -EPERM; 2771 } 2772 2773 #endif 2774 2775 static inline u32 tcp_timeout_init(struct sock *sk) 2776 { 2777 int timeout; 2778 2779 timeout = tcp_call_bpf(sk, BPF_SOCK_OPS_TIMEOUT_INIT, 0, NULL); 2780 2781 if (timeout <= 0) 2782 timeout = TCP_TIMEOUT_INIT; 2783 return min_t(int, timeout, TCP_RTO_MAX); 2784 } 2785 2786 static inline u32 tcp_rwnd_init_bpf(struct sock *sk) 2787 { 2788 int rwnd; 2789 2790 rwnd = tcp_call_bpf(sk, BPF_SOCK_OPS_RWND_INIT, 0, NULL); 2791 2792 if (rwnd < 0) 2793 rwnd = 0; 2794 return rwnd; 2795 } 2796 2797 static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) 2798 { 2799 return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN, 0, NULL) == 1); 2800 } 2801 2802 static inline void tcp_bpf_rtt(struct sock *sk, long mrtt, u32 srtt) 2803 { 2804 if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_RTT_CB_FLAG)) 2805 tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_RTT_CB, mrtt, srtt); 2806 } 2807 2808 #if IS_ENABLED(CONFIG_SMC) 2809 extern struct static_key_false tcp_have_smc; 2810 #endif 2811 2812 #if IS_ENABLED(CONFIG_TLS_DEVICE) 2813 void clean_acked_data_enable(struct tcp_sock *tp, 2814 void (*cad)(struct sock *sk, u32 ack_seq)); 2815 void clean_acked_data_disable(struct tcp_sock *tp); 2816 void clean_acked_data_flush(void); 2817 #endif 2818 2819 DECLARE_STATIC_KEY_FALSE(tcp_tx_delay_enabled); 2820 static inline void tcp_add_tx_delay(struct sk_buff *skb, 2821 const struct tcp_sock *tp) 2822 { 2823 if (static_branch_unlikely(&tcp_tx_delay_enabled)) 2824 skb->skb_mstamp_ns += (u64)tp->tcp_tx_delay * NSEC_PER_USEC; 2825 } 2826 2827 /* Compute Earliest Departure Time for some control packets 2828 * like ACK or RST for TIME_WAIT or non ESTABLISHED sockets. 2829 */ 2830 static inline u64 tcp_transmit_time(const struct sock *sk) 2831 { 2832 if (static_branch_unlikely(&tcp_tx_delay_enabled)) { 2833 u32 delay = (sk->sk_state == TCP_TIME_WAIT) ? 2834 tcp_twsk(sk)->tw_tx_delay : tcp_sk(sk)->tcp_tx_delay; 2835 2836 return tcp_clock_ns() + (u64)delay * NSEC_PER_USEC; 2837 } 2838 return 0; 2839 } 2840 2841 static inline int tcp_parse_auth_options(const struct tcphdr *th, 2842 const u8 **md5_hash, const struct tcp_ao_hdr **aoh) 2843 { 2844 const u8 *md5_tmp, *ao_tmp; 2845 int ret; 2846 2847 ret = tcp_do_parse_auth_options(th, &md5_tmp, &ao_tmp); 2848 if (ret) 2849 return ret; 2850 2851 if (md5_hash) 2852 *md5_hash = md5_tmp; 2853 2854 if (aoh) { 2855 if (!ao_tmp) 2856 *aoh = NULL; 2857 else 2858 *aoh = (struct tcp_ao_hdr *)(ao_tmp - 2); 2859 } 2860 2861 return 0; 2862 } 2863 2864 static inline bool tcp_ao_required(struct sock *sk, const void *saddr, 2865 int family, int l3index, bool stat_inc) 2866 { 2867 #ifdef CONFIG_TCP_AO 2868 struct tcp_ao_info *ao_info; 2869 struct tcp_ao_key *ao_key; 2870 2871 if (!static_branch_unlikely(&tcp_ao_needed.key)) 2872 return false; 2873 2874 ao_info = rcu_dereference_check(tcp_sk(sk)->ao_info, 2875 lockdep_sock_is_held(sk)); 2876 if (!ao_info) 2877 return false; 2878 2879 ao_key = tcp_ao_do_lookup(sk, l3index, saddr, family, -1, -1); 2880 if (ao_info->ao_required || ao_key) { 2881 if (stat_inc) { 2882 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOREQUIRED); 2883 atomic64_inc(&ao_info->counters.ao_required); 2884 } 2885 return true; 2886 } 2887 #endif 2888 return false; 2889 } 2890 2891 enum skb_drop_reason tcp_inbound_hash(struct sock *sk, 2892 const struct request_sock *req, const struct sk_buff *skb, 2893 const void *saddr, const void *daddr, 2894 int family, int dif, int sdif); 2895 2896 #endif /* _TCP_H */ 2897