1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * Definitions for the TCP module. 8 * 9 * Version: @(#)tcp.h 1.0.5 05/23/93 10 * 11 * Authors: Ross Biro 12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 13 */ 14#ifndef _TCP_H 15#define _TCP_H 16 17#define FASTRETRANS_DEBUG 1 18 19#include <linux/list.h> 20#include <linux/tcp.h> 21#include <linux/bug.h> 22#include <linux/slab.h> 23#include <linux/cache.h> 24#include <linux/percpu.h> 25#include <linux/skbuff.h> 26#include <linux/kref.h> 27#include <linux/ktime.h> 28#include <linux/indirect_call_wrapper.h> 29 30#include <net/inet_connection_sock.h> 31#include <net/inet_timewait_sock.h> 32#include <net/inet_hashtables.h> 33#include <net/checksum.h> 34#include <net/request_sock.h> 35#include <net/sock_reuseport.h> 36#include <net/sock.h> 37#include <net/snmp.h> 38#include <net/ip.h> 39#include <net/tcp_states.h> 40#include <net/inet_ecn.h> 41#include <net/dst.h> 42#include <net/mptcp.h> 43#ifdef CONFIG_NEWIP 44#include <linux/nip.h> /* NIP */ 45#endif 46#include <linux/seq_file.h> 47#include <linux/memcontrol.h> 48#include <linux/bpf-cgroup.h> 49#include <linux/siphash.h> 50 51extern struct inet_hashinfo tcp_hashinfo; 52 53DECLARE_PER_CPU(unsigned int, tcp_orphan_count); 54int tcp_orphan_count_sum(void); 55 56void tcp_time_wait(struct sock *sk, int state, int timeo); 57 58#define MAX_TCP_HEADER L1_CACHE_ALIGN(128 + MAX_HEADER) 59#define MAX_TCP_OPTION_SPACE 40 60#define TCP_MIN_SND_MSS 48 61#define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE) 62 63/* 64 * Never offer a window over 32767 without using window scaling. Some 65 * poor stacks do signed 16bit maths! 66 */ 67#define MAX_TCP_WINDOW 32767U 68 69/* Minimal accepted MSS. It is (60+60+8) - (20+20). */ 70#define TCP_MIN_MSS 88U 71 72/* The initial MTU to use for probing */ 73#define TCP_BASE_MSS 1024 74 75/* probing interval, default to 10 minutes as per RFC4821 */ 76#define TCP_PROBE_INTERVAL 600 77 78/* Specify interval when tcp mtu probing will stop */ 79#define TCP_PROBE_THRESHOLD 8 80 81/* After receiving this amount of duplicate ACKs fast retransmit starts. */ 82#define TCP_FASTRETRANS_THRESH 3 83 84/* Maximal number of ACKs sent quickly to accelerate slow-start. */ 85#define TCP_MAX_QUICKACKS 16U 86 87/* Maximal number of window scale according to RFC1323 */ 88#define TCP_MAX_WSCALE 14U 89 90/* urg_data states */ 91#define TCP_URG_VALID 0x0100 92#define TCP_URG_NOTYET 0x0200 93#define TCP_URG_READ 0x0400 94 95#define TCP_RETR1 3 /* 96 * This is how many retries it does before it 97 * tries to figure out if the gateway is 98 * down. Minimal RFC value is 3; it corresponds 99 * to ~3sec-8min depending on RTO. 100 */ 101 102#define TCP_RETR2 15 /* 103 * This should take at least 104 * 90 minutes to time out. 105 * RFC1122 says that the limit is 100 sec. 106 * 15 is ~13-30min depending on RTO. 107 */ 108 109#define TCP_SYN_RETRIES 6 /* This is how many retries are done 110 * when active opening a connection. 111 * RFC1122 says the minimum retry MUST 112 * be at least 180secs. Nevertheless 113 * this value is corresponding to 114 * 63secs of retransmission with the 115 * current initial RTO. 116 */ 117 118#define TCP_SYNACK_RETRIES 5 /* This is how may retries are done 119 * when passive opening a connection. 120 * This is corresponding to 31secs of 121 * retransmission with the current 122 * initial RTO. 123 */ 124 125#define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT 126 * state, about 60 seconds */ 127#define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN 128 /* BSD style FIN_WAIT2 deadlock breaker. 129 * It used to be 3min, new value is 60sec, 130 * to combine FIN-WAIT-2 timeout with 131 * TIME-WAIT timer. 132 */ 133#define TCP_FIN_TIMEOUT_MAX (120 * HZ) /* max TCP_LINGER2 value (two minutes) */ 134 135#define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ 136#if HZ >= 100 137#define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ 138#define TCP_ATO_MIN ((unsigned)(HZ/25)) 139#else 140#define TCP_DELACK_MIN 4U 141#define TCP_ATO_MIN 4U 142#endif 143#define TCP_RTO_MAX ((unsigned)(120*HZ)) 144#define TCP_RTO_MIN ((unsigned)(HZ/5)) 145#define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ 146 147#define TCP_TIMEOUT_MIN_US (2*USEC_PER_MSEC) /* Min TCP timeout in microsecs */ 148 149#define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ 150#define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now 151 * used as a fallback RTO for the 152 * initial data transmission if no 153 * valid RTT sample has been acquired, 154 * most likely due to retrans in 3WHS. 155 */ 156 157#define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes 158 * for local resources. 159 */ 160#define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ 161#define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ 162#define TCP_KEEPALIVE_INTVL (75*HZ) 163 164#define MAX_TCP_KEEPIDLE 32767 165#define MAX_TCP_KEEPINTVL 32767 166#define MAX_TCP_KEEPCNT 127 167#define MAX_TCP_SYNCNT 127 168 169#define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ 170 171#define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) 172#define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated 173 * after this time. It should be equal 174 * (or greater than) TCP_TIMEWAIT_LEN 175 * to provide reliability equal to one 176 * provided by timewait state. 177 */ 178#define TCP_PAWS_WINDOW 1 /* Replay window for per-host 179 * timestamps. It must be less than 180 * minimal timewait lifetime. 181 */ 182/* 183 * TCP option 184 */ 185 186#define TCPOPT_NOP 1 /* Padding */ 187#define TCPOPT_EOL 0 /* End of options */ 188#define TCPOPT_MSS 2 /* Segment size negotiating */ 189#define TCPOPT_WINDOW 3 /* Window scaling */ 190#define TCPOPT_SACK_PERM 4 /* SACK Permitted */ 191#define TCPOPT_SACK 5 /* SACK Block */ 192#define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ 193#define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ 194#define TCPOPT_MPTCP 30 /* Multipath TCP (RFC6824) */ 195#define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ 196#define TCPOPT_EXP 254 /* Experimental */ 197/* Magic number to be after the option value for sharing TCP 198 * experimental options. See draft-ietf-tcpm-experimental-options-00.txt 199 */ 200#define TCPOPT_FASTOPEN_MAGIC 0xF989 201#define TCPOPT_SMC_MAGIC 0xE2D4C3D9 202 203/* 204 * TCP option lengths 205 */ 206 207#define TCPOLEN_MSS 4 208#define TCPOLEN_WINDOW 3 209#define TCPOLEN_SACK_PERM 2 210#define TCPOLEN_TIMESTAMP 10 211#define TCPOLEN_MD5SIG 18 212#define TCPOLEN_FASTOPEN_BASE 2 213#define TCPOLEN_EXP_FASTOPEN_BASE 4 214#define TCPOLEN_EXP_SMC_BASE 6 215 216/* But this is what stacks really send out. */ 217#define TCPOLEN_TSTAMP_ALIGNED 12 218#define TCPOLEN_WSCALE_ALIGNED 4 219#define TCPOLEN_SACKPERM_ALIGNED 4 220#define TCPOLEN_SACK_BASE 2 221#define TCPOLEN_SACK_BASE_ALIGNED 4 222#define TCPOLEN_SACK_PERBLOCK 8 223#define TCPOLEN_MD5SIG_ALIGNED 20 224#define TCPOLEN_MSS_ALIGNED 4 225#define TCPOLEN_EXP_SMC_BASE_ALIGNED 8 226 227/* Flags in tp->nonagle */ 228#define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ 229#define TCP_NAGLE_CORK 2 /* Socket is corked */ 230#define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ 231 232/* TCP thin-stream limits */ 233#define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ 234 235/* TCP initial congestion window as per rfc6928 */ 236#define TCP_INIT_CWND 10 237 238/* Bit Flags for sysctl_tcp_fastopen */ 239#define TFO_CLIENT_ENABLE 1 240#define TFO_SERVER_ENABLE 2 241#define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ 242 243/* Accept SYN data w/o any cookie option */ 244#define TFO_SERVER_COOKIE_NOT_REQD 0x200 245 246/* Force enable TFO on all listeners, i.e., not requiring the 247 * TCP_FASTOPEN socket option. 248 */ 249#define TFO_SERVER_WO_SOCKOPT1 0x400 250 251 252/* sysctl variables for tcp */ 253extern int sysctl_tcp_max_orphans; 254extern long sysctl_tcp_mem[3]; 255 256#define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ 257#define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */ 258#define TCP_RACK_NO_DUPTHRESH 0x4 /* Do not use DUPACK threshold in RACK */ 259 260extern atomic_long_t tcp_memory_allocated; 261extern struct percpu_counter tcp_sockets_allocated; 262extern unsigned long tcp_memory_pressure; 263 264/* optimized version of sk_under_memory_pressure() for TCP sockets */ 265static inline bool tcp_under_memory_pressure(const struct sock *sk) 266{ 267 if (mem_cgroup_sockets_enabled && sk->sk_memcg && 268 mem_cgroup_under_socket_pressure(sk->sk_memcg)) 269 return true; 270 271 return READ_ONCE(tcp_memory_pressure); 272} 273/* 274 * The next routines deal with comparing 32 bit unsigned ints 275 * and worry about wraparound (automatic with unsigned arithmetic). 276 */ 277 278static inline bool before(__u32 seq1, __u32 seq2) 279{ 280 return (__s32)(seq1-seq2) < 0; 281} 282#define after(seq2, seq1) before(seq1, seq2) 283 284/* is s2<=s1<=s3 ? */ 285static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) 286{ 287 return seq3 - seq2 >= seq1 - seq2; 288} 289 290static inline bool tcp_out_of_memory(struct sock *sk) 291{ 292 if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && 293 sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2)) 294 return true; 295 return false; 296} 297 298void sk_forced_mem_schedule(struct sock *sk, int size); 299 300bool tcp_check_oom(struct sock *sk, int shift); 301 302 303extern struct proto tcp_prot; 304 305#define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) 306#define __TCP_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.tcp_statistics, field) 307#define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) 308#define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) 309 310void tcp_tasklet_init(void); 311 312int tcp_v4_err(struct sk_buff *skb, u32); 313 314void tcp_shutdown(struct sock *sk, int how); 315 316int tcp_v4_early_demux(struct sk_buff *skb); 317int tcp_v4_rcv(struct sk_buff *skb); 318 319int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); 320int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); 321int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size); 322int tcp_sendpage(struct sock *sk, struct page *page, int offset, size_t size, 323 int flags); 324int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset, 325 size_t size, int flags); 326ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, 327 size_t size, int flags); 328int tcp_send_mss(struct sock *sk, int *size_goal, int flags); 329void tcp_push(struct sock *sk, int flags, int mss_now, int nonagle, 330 int size_goal); 331void tcp_release_cb(struct sock *sk); 332void tcp_wfree(struct sk_buff *skb); 333void tcp_write_timer_handler(struct sock *sk); 334void tcp_delack_timer_handler(struct sock *sk); 335int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg); 336int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); 337void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); 338void tcp_rcv_space_adjust(struct sock *sk); 339int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); 340void tcp_twsk_destructor(struct sock *sk); 341ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, 342 struct pipe_inode_info *pipe, size_t len, 343 unsigned int flags); 344 345static inline void tcp_dec_quickack_mode(struct sock *sk) 346{ 347 struct inet_connection_sock *icsk = inet_csk(sk); 348 349 if (icsk->icsk_ack.quick) { 350 /* How many ACKs S/ACKing new data have we sent? */ 351 const unsigned int pkts = inet_csk_ack_scheduled(sk) ? 1 : 0; 352 353 if (pkts >= icsk->icsk_ack.quick) { 354 icsk->icsk_ack.quick = 0; 355 /* Leaving quickack mode we deflate ATO. */ 356 icsk->icsk_ack.ato = TCP_ATO_MIN; 357 } else 358 icsk->icsk_ack.quick -= pkts; 359 } 360} 361 362#define TCP_ECN_OK 1 363#define TCP_ECN_QUEUE_CWR 2 364#define TCP_ECN_DEMAND_CWR 4 365#define TCP_ECN_SEEN 8 366 367enum tcp_tw_status { 368 TCP_TW_SUCCESS = 0, 369 TCP_TW_RST = 1, 370 TCP_TW_ACK = 2, 371 TCP_TW_SYN = 3 372}; 373 374 375enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, 376 struct sk_buff *skb, 377 const struct tcphdr *th); 378struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, 379 struct request_sock *req, bool fastopen, 380 bool *lost_race); 381int tcp_child_process(struct sock *parent, struct sock *child, 382 struct sk_buff *skb); 383void tcp_enter_loss(struct sock *sk); 384void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int flag); 385void tcp_clear_retrans(struct tcp_sock *tp); 386void tcp_update_metrics(struct sock *sk); 387void tcp_init_metrics(struct sock *sk); 388void tcp_metrics_init(void); 389bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst); 390void __tcp_close(struct sock *sk, long timeout); 391void tcp_close(struct sock *sk, long timeout); 392void tcp_init_sock(struct sock *sk); 393void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb); 394__poll_t tcp_poll(struct file *file, struct socket *sock, 395 struct poll_table_struct *wait); 396int tcp_getsockopt(struct sock *sk, int level, int optname, 397 char __user *optval, int __user *optlen); 398bool tcp_bpf_bypass_getsockopt(int level, int optname); 399int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 400 unsigned int optlen); 401void tcp_set_keepalive(struct sock *sk, int val); 402void tcp_syn_ack_timeout(const struct request_sock *req); 403int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, 404 int flags, int *addr_len); 405int tcp_set_rcvlowat(struct sock *sk, int val); 406void tcp_data_ready(struct sock *sk); 407#ifdef CONFIG_MMU 408int tcp_mmap(struct file *file, struct socket *sock, 409 struct vm_area_struct *vma); 410#endif 411void tcp_parse_options(const struct net *net, const struct sk_buff *skb, 412 struct tcp_options_received *opt_rx, 413 int estab, struct tcp_fastopen_cookie *foc); 414const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); 415 416/* 417 * BPF SKB-less helpers 418 */ 419u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, 420 struct tcphdr *th, u32 *cookie); 421u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, 422 struct tcphdr *th, u32 *cookie); 423u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, 424 const struct tcp_request_sock_ops *af_ops, 425 struct sock *sk, struct tcphdr *th); 426/* 427 * TCP v4 functions exported for the inet6 API 428 */ 429 430void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); 431void tcp_v4_mtu_reduced(struct sock *sk); 432void tcp_req_err(struct sock *sk, u32 seq, bool abort); 433void tcp_ld_RTO_revert(struct sock *sk, u32 seq); 434int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); 435struct sock *tcp_create_openreq_child(const struct sock *sk, 436 struct request_sock *req, 437 struct sk_buff *skb); 438void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); 439struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, 440 struct request_sock *req, 441 struct dst_entry *dst, 442 struct request_sock *req_unhash, 443 bool *own_req); 444int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); 445int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); 446int tcp_connect(struct sock *sk); 447enum tcp_synack_type { 448 TCP_SYNACK_NORMAL, 449 TCP_SYNACK_FASTOPEN, 450 TCP_SYNACK_COOKIE, 451}; 452struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, 453 struct request_sock *req, 454 struct tcp_fastopen_cookie *foc, 455 enum tcp_synack_type synack_type, 456 struct sk_buff *syn_skb); 457int tcp_disconnect(struct sock *sk, int flags); 458 459void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); 460int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); 461void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); 462 463/* From syncookies.c */ 464struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, 465 struct request_sock *req, 466 struct dst_entry *dst, u32 tsoff); 467int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, 468 u32 cookie); 469struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); 470struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, 471 const struct tcp_request_sock_ops *af_ops, 472 struct sock *sk, struct sk_buff *skb); 473#ifdef CONFIG_SYN_COOKIES 474 475/* Syncookies use a monotonic timer which increments every 60 seconds. 476 * This counter is used both as a hash input and partially encoded into 477 * the cookie value. A cookie is only validated further if the delta 478 * between the current counter value and the encoded one is less than this, 479 * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if 480 * the counter advances immediately after a cookie is generated). 481 */ 482#define MAX_SYNCOOKIE_AGE 2 483#define TCP_SYNCOOKIE_PERIOD (60 * HZ) 484#define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) 485 486/* syncookies: remember time of last synqueue overflow 487 * But do not dirty this field too often (once per second is enough) 488 * It is racy as we do not hold a lock, but race is very minor. 489 */ 490static inline void tcp_synq_overflow(const struct sock *sk) 491{ 492 unsigned int last_overflow; 493 unsigned int now = jiffies; 494 495 if (sk->sk_reuseport) { 496 struct sock_reuseport *reuse; 497 498 reuse = rcu_dereference(sk->sk_reuseport_cb); 499 if (likely(reuse)) { 500 last_overflow = READ_ONCE(reuse->synq_overflow_ts); 501 if (!time_between32(now, last_overflow, 502 last_overflow + HZ)) 503 WRITE_ONCE(reuse->synq_overflow_ts, now); 504 return; 505 } 506 } 507 508 last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); 509 if (!time_between32(now, last_overflow, last_overflow + HZ)) 510 WRITE_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp, now); 511} 512 513/* syncookies: no recent synqueue overflow on this listening socket? */ 514static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) 515{ 516 unsigned int last_overflow; 517 unsigned int now = jiffies; 518 519 if (sk->sk_reuseport) { 520 struct sock_reuseport *reuse; 521 522 reuse = rcu_dereference(sk->sk_reuseport_cb); 523 if (likely(reuse)) { 524 last_overflow = READ_ONCE(reuse->synq_overflow_ts); 525 return !time_between32(now, last_overflow - HZ, 526 last_overflow + 527 TCP_SYNCOOKIE_VALID); 528 } 529 } 530 531 last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); 532 533 /* If last_overflow <= jiffies <= last_overflow + TCP_SYNCOOKIE_VALID, 534 * then we're under synflood. However, we have to use 535 * 'last_overflow - HZ' as lower bound. That's because a concurrent 536 * tcp_synq_overflow() could update .ts_recent_stamp after we read 537 * jiffies but before we store .ts_recent_stamp into last_overflow, 538 * which could lead to rejecting a valid syncookie. 539 */ 540 return !time_between32(now, last_overflow - HZ, 541 last_overflow + TCP_SYNCOOKIE_VALID); 542} 543 544static inline u32 tcp_cookie_time(void) 545{ 546 u64 val = get_jiffies_64(); 547 548 do_div(val, TCP_SYNCOOKIE_PERIOD); 549 return val; 550} 551 552u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, 553 u16 *mssp); 554__u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); 555u64 cookie_init_timestamp(struct request_sock *req, u64 now); 556bool cookie_timestamp_decode(const struct net *net, 557 struct tcp_options_received *opt); 558bool cookie_ecn_ok(const struct tcp_options_received *opt, 559 const struct net *net, const struct dst_entry *dst); 560 561/* From net/ipv6/syncookies.c */ 562int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, 563 u32 cookie); 564struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); 565 566u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, 567 const struct tcphdr *th, u16 *mssp); 568__u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); 569#endif 570/* tcp_output.c */ 571 572void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, 573 int nonagle); 574int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); 575int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); 576void tcp_retransmit_timer(struct sock *sk); 577void tcp_xmit_retransmit_queue(struct sock *); 578void tcp_simple_retransmit(struct sock *); 579void tcp_enter_recovery(struct sock *sk, bool ece_ack); 580int tcp_trim_head(struct sock *, struct sk_buff *, u32); 581enum tcp_queue { 582 TCP_FRAG_IN_WRITE_QUEUE, 583 TCP_FRAG_IN_RTX_QUEUE, 584}; 585int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, 586 struct sk_buff *skb, u32 len, 587 unsigned int mss_now, gfp_t gfp); 588 589void tcp_send_probe0(struct sock *); 590void tcp_send_partial(struct sock *); 591int tcp_write_wakeup(struct sock *, int mib); 592void tcp_send_fin(struct sock *sk); 593void tcp_send_active_reset(struct sock *sk, gfp_t priority); 594int tcp_send_synack(struct sock *); 595void tcp_push_one(struct sock *, unsigned int mss_now); 596void __tcp_send_ack(struct sock *sk, u32 rcv_nxt); 597void tcp_send_ack(struct sock *sk); 598void tcp_send_delayed_ack(struct sock *sk); 599void tcp_send_loss_probe(struct sock *sk); 600bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto); 601void tcp_skb_collapse_tstamp(struct sk_buff *skb, 602 const struct sk_buff *next_skb); 603 604/* tcp_input.c */ 605void tcp_rearm_rto(struct sock *sk); 606void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); 607void tcp_reset(struct sock *sk); 608void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb); 609void tcp_fin(struct sock *sk); 610void tcp_check_space(struct sock *sk); 611 612/* tcp_timer.c */ 613void tcp_init_xmit_timers(struct sock *); 614static inline void tcp_clear_xmit_timers(struct sock *sk) 615{ 616 if (hrtimer_try_to_cancel(&tcp_sk(sk)->pacing_timer) == 1) 617 __sock_put(sk); 618 619 if (hrtimer_try_to_cancel(&tcp_sk(sk)->compressed_ack_timer) == 1) 620 __sock_put(sk); 621 622 inet_csk_clear_xmit_timers(sk); 623} 624 625unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); 626unsigned int tcp_current_mss(struct sock *sk); 627u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when); 628 629/* Bound MSS / TSO packet size with the half of the window */ 630static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) 631{ 632 int cutoff; 633 634 /* When peer uses tiny windows, there is no use in packetizing 635 * to sub-MSS pieces for the sake of SWS or making sure there 636 * are enough packets in the pipe for fast recovery. 637 * 638 * On the other hand, for extremely large MSS devices, handling 639 * smaller than MSS windows in this way does make sense. 640 */ 641 if (tp->max_window > TCP_MSS_DEFAULT) 642 cutoff = (tp->max_window >> 1); 643 else 644 cutoff = tp->max_window; 645 646 if (cutoff && pktsize > cutoff) 647 return max_t(int, cutoff, 68U - tp->tcp_header_len); 648 else 649 return pktsize; 650} 651 652/* tcp.c */ 653void tcp_get_info(struct sock *, struct tcp_info *); 654 655/* Read 'sendfile()'-style from a TCP socket */ 656int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, 657 sk_read_actor_t recv_actor); 658 659void tcp_initialize_rcv_mss(struct sock *sk); 660 661int tcp_mtu_to_mss(struct sock *sk, int pmtu); 662int tcp_mss_to_mtu(struct sock *sk, int mss); 663void tcp_mtup_init(struct sock *sk); 664 665static inline void tcp_bound_rto(const struct sock *sk) 666{ 667 if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) 668 inet_csk(sk)->icsk_rto = TCP_RTO_MAX; 669} 670 671static inline u32 __tcp_set_rto(const struct tcp_sock *tp) 672{ 673 return usecs_to_jiffies((tp->srtt_us >> 3) + tp->rttvar_us); 674} 675 676static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) 677{ 678 /* mptcp hooks are only on the slow path */ 679 if (sk_is_mptcp((struct sock *)tp)) 680 return; 681 682 tp->pred_flags = htonl((tp->tcp_header_len << 26) | 683 ntohl(TCP_FLAG_ACK) | 684 snd_wnd); 685} 686 687static inline void tcp_fast_path_on(struct tcp_sock *tp) 688{ 689 __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); 690} 691 692static inline void tcp_fast_path_check(struct sock *sk) 693{ 694 struct tcp_sock *tp = tcp_sk(sk); 695 696 if (RB_EMPTY_ROOT(&tp->out_of_order_queue) && 697 tp->rcv_wnd && 698 atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && 699 !tp->urg_data) 700 tcp_fast_path_on(tp); 701} 702 703/* Compute the actual rto_min value */ 704static inline u32 tcp_rto_min(struct sock *sk) 705{ 706 const struct dst_entry *dst = __sk_dst_get(sk); 707 u32 rto_min = inet_csk(sk)->icsk_rto_min; 708 709 if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) 710 rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); 711 return rto_min; 712} 713 714static inline u32 tcp_rto_min_us(struct sock *sk) 715{ 716 return jiffies_to_usecs(tcp_rto_min(sk)); 717} 718 719static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) 720{ 721 return dst_metric_locked(dst, RTAX_CC_ALGO); 722} 723 724/* Minimum RTT in usec. ~0 means not available. */ 725static inline u32 tcp_min_rtt(const struct tcp_sock *tp) 726{ 727 return minmax_get(&tp->rtt_min); 728} 729 730/* Compute the actual receive window we are currently advertising. 731 * Rcv_nxt can be after the window if our peer push more data 732 * than the offered window. 733 */ 734static inline u32 tcp_receive_window(const struct tcp_sock *tp) 735{ 736 s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; 737 738 if (win < 0) 739 win = 0; 740 return (u32) win; 741} 742 743/* Choose a new window, without checks for shrinking, and without 744 * scaling applied to the result. The caller does these things 745 * if necessary. This is a "raw" window selection. 746 */ 747u32 __tcp_select_window(struct sock *sk); 748 749void tcp_send_window_probe(struct sock *sk); 750 751/* TCP uses 32bit jiffies to save some space. 752 * Note that this is different from tcp_time_stamp, which 753 * historically has been the same until linux-4.13. 754 */ 755#define tcp_jiffies32 ((u32)jiffies) 756 757/* 758 * Deliver a 32bit value for TCP timestamp option (RFC 7323) 759 * It is no longer tied to jiffies, but to 1 ms clock. 760 * Note: double check if you want to use tcp_jiffies32 instead of this. 761 */ 762#define TCP_TS_HZ 1000 763 764static inline u64 tcp_clock_ns(void) 765{ 766 return ktime_get_ns(); 767} 768 769static inline u64 tcp_clock_us(void) 770{ 771 return div_u64(tcp_clock_ns(), NSEC_PER_USEC); 772} 773 774/* This should only be used in contexts where tp->tcp_mstamp is up to date */ 775static inline u32 tcp_time_stamp(const struct tcp_sock *tp) 776{ 777 return div_u64(tp->tcp_mstamp, USEC_PER_SEC / TCP_TS_HZ); 778} 779 780/* Convert a nsec timestamp into TCP TSval timestamp (ms based currently) */ 781static inline u64 tcp_ns_to_ts(u64 ns) 782{ 783 return div_u64(ns, NSEC_PER_SEC / TCP_TS_HZ); 784} 785 786/* Could use tcp_clock_us() / 1000, but this version uses a single divide */ 787static inline u32 tcp_time_stamp_raw(void) 788{ 789 return tcp_ns_to_ts(tcp_clock_ns()); 790} 791 792void tcp_mstamp_refresh(struct tcp_sock *tp); 793 794static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) 795{ 796 return max_t(s64, t1 - t0, 0); 797} 798 799static inline u32 tcp_skb_timestamp(const struct sk_buff *skb) 800{ 801 return tcp_ns_to_ts(skb->skb_mstamp_ns); 802} 803 804/* provide the departure time in us unit */ 805static inline u64 tcp_skb_timestamp_us(const struct sk_buff *skb) 806{ 807 return div_u64(skb->skb_mstamp_ns, NSEC_PER_USEC); 808} 809 810 811#define tcp_flag_byte(th) (((u_int8_t *)th)[13]) 812 813#define TCPHDR_FIN 0x01 814#define TCPHDR_SYN 0x02 815#define TCPHDR_RST 0x04 816#define TCPHDR_PSH 0x08 817#define TCPHDR_ACK 0x10 818#define TCPHDR_URG 0x20 819#define TCPHDR_ECE 0x40 820#define TCPHDR_CWR 0x80 821 822#define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) 823 824/* This is what the send packet queuing engine uses to pass 825 * TCP per-packet control information to the transmission code. 826 * We also store the host-order sequence numbers in here too. 827 * This is 44 bytes if IPV6 is enabled. 828 * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. 829 */ 830struct tcp_skb_cb { 831 __u32 seq; /* Starting sequence number */ 832 __u32 end_seq; /* SEQ + FIN + SYN + datalen */ 833 union { 834 /* Note : tcp_tw_isn is used in input path only 835 * (isn chosen by tcp_timewait_state_process()) 836 * 837 * tcp_gso_segs/size are used in write queue only, 838 * cf tcp_skb_pcount()/tcp_skb_mss() 839 */ 840 __u32 tcp_tw_isn; 841 struct { 842 u16 tcp_gso_segs; 843 u16 tcp_gso_size; 844 }; 845 }; 846 __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ 847 848 __u8 sacked; /* State flags for SACK. */ 849#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ 850#define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ 851#define TCPCB_LOST 0x04 /* SKB is lost */ 852#define TCPCB_TAGBITS 0x07 /* All tag bits */ 853#define TCPCB_REPAIRED 0x10 /* SKB repaired (no skb_mstamp_ns) */ 854#define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ 855#define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS| \ 856 TCPCB_REPAIRED) 857 858 __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ 859 __u8 txstamp_ack:1, /* Record TX timestamp for ack? */ 860 eor:1, /* Is skb MSG_EOR marked? */ 861 has_rxtstamp:1, /* SKB has a RX timestamp */ 862 unused:5; 863 __u32 ack_seq; /* Sequence number ACK'd */ 864 union { 865 struct { 866 /* There is space for up to 24 bytes */ 867 __u32 in_flight:30,/* Bytes in flight at transmit */ 868 is_app_limited:1, /* cwnd not fully used? */ 869 unused:1; 870 /* pkts S/ACKed so far upon tx of skb, incl retrans: */ 871 __u32 delivered; 872 /* start of send pipeline phase */ 873 u64 first_tx_mstamp; 874 /* when we reached the "delivered" count */ 875 u64 delivered_mstamp; 876 } tx; /* only used for outgoing skbs */ 877 union { 878 struct inet_skb_parm h4; 879#if IS_ENABLED(CONFIG_IPV6) 880 struct inet6_skb_parm h6; 881#endif 882#if IS_ENABLED(CONFIG_NEWIP) 883 struct ninet_skb_parm hnip; /* NIP */ 884#endif 885 } header; /* For incoming skbs */ 886 struct { 887 __u32 flags; 888 struct sock *sk_redir; 889 void *data_end; 890 } bpf; 891 }; 892}; 893 894#define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) 895 896static inline void bpf_compute_data_end_sk_skb(struct sk_buff *skb) 897{ 898 TCP_SKB_CB(skb)->bpf.data_end = skb->data + skb_headlen(skb); 899} 900 901static inline bool tcp_skb_bpf_ingress(const struct sk_buff *skb) 902{ 903 return TCP_SKB_CB(skb)->bpf.flags & BPF_F_INGRESS; 904} 905 906static inline struct sock *tcp_skb_bpf_redirect_fetch(struct sk_buff *skb) 907{ 908 return TCP_SKB_CB(skb)->bpf.sk_redir; 909} 910 911static inline void tcp_skb_bpf_redirect_clear(struct sk_buff *skb) 912{ 913 TCP_SKB_CB(skb)->bpf.sk_redir = NULL; 914} 915 916extern const struct inet_connection_sock_af_ops ipv4_specific; 917 918#if IS_ENABLED(CONFIG_IPV6) 919/* This is the variant of inet6_iif() that must be used by TCP, 920 * as TCP moves IP6CB into a different location in skb->cb[] 921 */ 922static inline int tcp_v6_iif(const struct sk_buff *skb) 923{ 924 return TCP_SKB_CB(skb)->header.h6.iif; 925} 926 927static inline int tcp_v6_iif_l3_slave(const struct sk_buff *skb) 928{ 929 bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); 930 931 return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; 932} 933 934/* TCP_SKB_CB reference means this can not be used from early demux */ 935static inline int tcp_v6_sdif(const struct sk_buff *skb) 936{ 937#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 938 if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags)) 939 return TCP_SKB_CB(skb)->header.h6.iif; 940#endif 941 return 0; 942} 943 944extern const struct inet_connection_sock_af_ops ipv6_specific; 945 946INDIRECT_CALLABLE_DECLARE(void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)); 947INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *skb)); 948void tcp_v6_early_demux(struct sk_buff *skb); 949 950#endif 951 952/* TCP_SKB_CB reference means this can not be used from early demux */ 953static inline int tcp_v4_sdif(struct sk_buff *skb) 954{ 955#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) 956 if (skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) 957 return TCP_SKB_CB(skb)->header.h4.iif; 958#endif 959 return 0; 960} 961 962/* Due to TSO, an SKB can be composed of multiple actual 963 * packets. To keep these tracked properly, we use this. 964 */ 965static inline int tcp_skb_pcount(const struct sk_buff *skb) 966{ 967 return TCP_SKB_CB(skb)->tcp_gso_segs; 968} 969 970static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) 971{ 972 TCP_SKB_CB(skb)->tcp_gso_segs = segs; 973} 974 975static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) 976{ 977 TCP_SKB_CB(skb)->tcp_gso_segs += segs; 978} 979 980/* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ 981static inline int tcp_skb_mss(const struct sk_buff *skb) 982{ 983 return TCP_SKB_CB(skb)->tcp_gso_size; 984} 985 986static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) 987{ 988 return likely(!TCP_SKB_CB(skb)->eor); 989} 990 991static inline bool tcp_skb_can_collapse(const struct sk_buff *to, 992 const struct sk_buff *from) 993{ 994 return likely(tcp_skb_can_collapse_to(to) && 995 mptcp_skb_can_collapse(to, from)); 996} 997 998/* Events passed to congestion control interface */ 999enum tcp_ca_event { 1000 CA_EVENT_TX_START, /* first transmit when no packets in flight */ 1001 CA_EVENT_CWND_RESTART, /* congestion window restart */ 1002 CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ 1003 CA_EVENT_LOSS, /* loss timeout */ 1004 CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ 1005 CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ 1006}; 1007 1008/* Information about inbound ACK, passed to cong_ops->in_ack_event() */ 1009enum tcp_ca_ack_event_flags { 1010 CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ 1011 CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ 1012 CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ 1013}; 1014 1015/* 1016 * Interface for adding new TCP congestion control handlers 1017 */ 1018#define TCP_CA_NAME_MAX 16 1019#define TCP_CA_MAX 128 1020#define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) 1021 1022#define TCP_CA_UNSPEC 0 1023 1024/* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ 1025#define TCP_CONG_NON_RESTRICTED 0x1 1026/* Requires ECN/ECT set on all packets */ 1027#define TCP_CONG_NEEDS_ECN 0x2 1028#define TCP_CONG_MASK (TCP_CONG_NON_RESTRICTED | TCP_CONG_NEEDS_ECN) 1029 1030union tcp_cc_info; 1031 1032struct ack_sample { 1033 u32 pkts_acked; 1034 s32 rtt_us; 1035 u32 in_flight; 1036}; 1037 1038/* A rate sample measures the number of (original/retransmitted) data 1039 * packets delivered "delivered" over an interval of time "interval_us". 1040 * The tcp_rate.c code fills in the rate sample, and congestion 1041 * control modules that define a cong_control function to run at the end 1042 * of ACK processing can optionally chose to consult this sample when 1043 * setting cwnd and pacing rate. 1044 * A sample is invalid if "delivered" or "interval_us" is negative. 1045 */ 1046struct rate_sample { 1047 u64 prior_mstamp; /* starting timestamp for interval */ 1048 u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ 1049 s32 delivered; /* number of packets delivered over interval */ 1050 long interval_us; /* time for tp->delivered to incr "delivered" */ 1051 u32 snd_interval_us; /* snd interval for delivered packets */ 1052 u32 rcv_interval_us; /* rcv interval for delivered packets */ 1053 long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ 1054 int losses; /* number of packets marked lost upon ACK */ 1055 u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ 1056 u32 prior_in_flight; /* in flight before this ACK */ 1057 u32 last_end_seq; /* end_seq of most recently ACKed packet */ 1058 bool is_app_limited; /* is sample from packet with bubble in pipe? */ 1059 bool is_retrans; /* is sample from retransmission? */ 1060 bool is_ack_delayed; /* is this (likely) a delayed ACK? */ 1061}; 1062 1063struct tcp_congestion_ops { 1064 struct list_head list; 1065 u32 key; 1066 u32 flags; 1067 1068 /* initialize private data (optional) */ 1069 void (*init)(struct sock *sk); 1070 /* cleanup private data (optional) */ 1071 void (*release)(struct sock *sk); 1072 1073 /* return slow start threshold (required) */ 1074 u32 (*ssthresh)(struct sock *sk); 1075 /* do new cwnd calculation (required) */ 1076 void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); 1077 /* call before changing ca_state (optional) */ 1078 void (*set_state)(struct sock *sk, u8 new_state); 1079 /* call when cwnd event occurs (optional) */ 1080 void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); 1081 /* call when ack arrives (optional) */ 1082 void (*in_ack_event)(struct sock *sk, u32 flags); 1083 /* new value of cwnd after loss (required) */ 1084 u32 (*undo_cwnd)(struct sock *sk); 1085 /* hook for packet ack accounting (optional) */ 1086 void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); 1087 /* override sysctl_tcp_min_tso_segs */ 1088 u32 (*min_tso_segs)(struct sock *sk); 1089 /* returns the multiplier used in tcp_sndbuf_expand (optional) */ 1090 u32 (*sndbuf_expand)(struct sock *sk); 1091 /* call when packets are delivered to update cwnd and pacing rate, 1092 * after all the ca_state processing. (optional) 1093 */ 1094 void (*cong_control)(struct sock *sk, const struct rate_sample *rs); 1095 /* get info for inet_diag (optional) */ 1096 size_t (*get_info)(struct sock *sk, u32 ext, int *attr, 1097 union tcp_cc_info *info); 1098 1099 char name[TCP_CA_NAME_MAX]; 1100 struct module *owner; 1101}; 1102 1103int tcp_register_congestion_control(struct tcp_congestion_ops *type); 1104void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); 1105 1106void tcp_assign_congestion_control(struct sock *sk); 1107void tcp_init_congestion_control(struct sock *sk); 1108void tcp_cleanup_congestion_control(struct sock *sk); 1109int tcp_set_default_congestion_control(struct net *net, const char *name); 1110void tcp_get_default_congestion_control(struct net *net, char *name); 1111void tcp_get_available_congestion_control(char *buf, size_t len); 1112void tcp_get_allowed_congestion_control(char *buf, size_t len); 1113int tcp_set_allowed_congestion_control(char *allowed); 1114int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, 1115 bool cap_net_admin); 1116u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); 1117void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); 1118 1119u32 tcp_reno_ssthresh(struct sock *sk); 1120u32 tcp_reno_undo_cwnd(struct sock *sk); 1121void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); 1122extern struct tcp_congestion_ops tcp_reno; 1123 1124struct tcp_congestion_ops *tcp_ca_find(const char *name); 1125struct tcp_congestion_ops *tcp_ca_find_key(u32 key); 1126u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_ca); 1127#ifdef CONFIG_INET 1128char *tcp_ca_get_name_by_key(u32 key, char *buffer); 1129#else 1130static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) 1131{ 1132 return NULL; 1133} 1134#endif 1135 1136static inline bool tcp_ca_needs_ecn(const struct sock *sk) 1137{ 1138 const struct inet_connection_sock *icsk = inet_csk(sk); 1139 1140 return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; 1141} 1142 1143static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state) 1144{ 1145 struct inet_connection_sock *icsk = inet_csk(sk); 1146 1147 if (icsk->icsk_ca_ops->set_state) 1148 icsk->icsk_ca_ops->set_state(sk, ca_state); 1149 icsk->icsk_ca_state = ca_state; 1150} 1151 1152static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) 1153{ 1154 const struct inet_connection_sock *icsk = inet_csk(sk); 1155 1156 if (icsk->icsk_ca_ops->cwnd_event) 1157 icsk->icsk_ca_ops->cwnd_event(sk, event); 1158} 1159 1160/* From tcp_rate.c */ 1161void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); 1162void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, 1163 struct rate_sample *rs); 1164void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, 1165 bool is_sack_reneg, struct rate_sample *rs); 1166void tcp_rate_check_app_limited(struct sock *sk); 1167 1168static inline bool tcp_skb_sent_after(u64 t1, u64 t2, u32 seq1, u32 seq2) 1169{ 1170 return t1 > t2 || (t1 == t2 && after(seq1, seq2)); 1171} 1172 1173/* These functions determine how the current flow behaves in respect of SACK 1174 * handling. SACK is negotiated with the peer, and therefore it can vary 1175 * between different flows. 1176 * 1177 * tcp_is_sack - SACK enabled 1178 * tcp_is_reno - No SACK 1179 */ 1180static inline int tcp_is_sack(const struct tcp_sock *tp) 1181{ 1182 return likely(tp->rx_opt.sack_ok); 1183} 1184 1185static inline bool tcp_is_reno(const struct tcp_sock *tp) 1186{ 1187 return !tcp_is_sack(tp); 1188} 1189 1190static inline unsigned int tcp_left_out(const struct tcp_sock *tp) 1191{ 1192 return tp->sacked_out + tp->lost_out; 1193} 1194 1195/* This determines how many packets are "in the network" to the best 1196 * of our knowledge. In many cases it is conservative, but where 1197 * detailed information is available from the receiver (via SACK 1198 * blocks etc.) we can make more aggressive calculations. 1199 * 1200 * Use this for decisions involving congestion control, use just 1201 * tp->packets_out to determine if the send queue is empty or not. 1202 * 1203 * Read this equation as: 1204 * 1205 * "Packets sent once on transmission queue" MINUS 1206 * "Packets left network, but not honestly ACKed yet" PLUS 1207 * "Packets fast retransmitted" 1208 */ 1209static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) 1210{ 1211 return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; 1212} 1213 1214#define TCP_INFINITE_SSTHRESH 0x7fffffff 1215 1216static inline bool tcp_in_slow_start(const struct tcp_sock *tp) 1217{ 1218 return tp->snd_cwnd < tp->snd_ssthresh; 1219} 1220 1221static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) 1222{ 1223 return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; 1224} 1225 1226static inline bool tcp_in_cwnd_reduction(const struct sock *sk) 1227{ 1228 return (TCPF_CA_CWR | TCPF_CA_Recovery) & 1229 (1 << inet_csk(sk)->icsk_ca_state); 1230} 1231 1232/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. 1233 * The exception is cwnd reduction phase, when cwnd is decreasing towards 1234 * ssthresh. 1235 */ 1236static inline __u32 tcp_current_ssthresh(const struct sock *sk) 1237{ 1238 const struct tcp_sock *tp = tcp_sk(sk); 1239 1240 if (tcp_in_cwnd_reduction(sk)) 1241 return tp->snd_ssthresh; 1242 else 1243 return max(tp->snd_ssthresh, 1244 ((tp->snd_cwnd >> 1) + 1245 (tp->snd_cwnd >> 2))); 1246} 1247 1248/* Use define here intentionally to get WARN_ON location shown at the caller */ 1249#define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) 1250 1251void tcp_enter_cwr(struct sock *sk); 1252__u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); 1253 1254/* The maximum number of MSS of available cwnd for which TSO defers 1255 * sending if not using sysctl_tcp_tso_win_divisor. 1256 */ 1257static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) 1258{ 1259 return 3; 1260} 1261 1262/* Returns end sequence number of the receiver's advertised window */ 1263static inline u32 tcp_wnd_end(const struct tcp_sock *tp) 1264{ 1265 return tp->snd_una + tp->snd_wnd; 1266} 1267 1268/* We follow the spirit of RFC2861 to validate cwnd but implement a more 1269 * flexible approach. The RFC suggests cwnd should not be raised unless 1270 * it was fully used previously. And that's exactly what we do in 1271 * congestion avoidance mode. But in slow start we allow cwnd to grow 1272 * as long as the application has used half the cwnd. 1273 * Example : 1274 * cwnd is 10 (IW10), but application sends 9 frames. 1275 * We allow cwnd to reach 18 when all frames are ACKed. 1276 * This check is safe because it's as aggressive as slow start which already 1277 * risks 100% overshoot. The advantage is that we discourage application to 1278 * either send more filler packets or data to artificially blow up the cwnd 1279 * usage, and allow application-limited process to probe bw more aggressively. 1280 */ 1281static inline bool tcp_is_cwnd_limited(const struct sock *sk) 1282{ 1283 const struct tcp_sock *tp = tcp_sk(sk); 1284 1285 if (tp->is_cwnd_limited) 1286 return true; 1287 1288 /* If in slow start, ensure cwnd grows to twice what was ACKed. */ 1289 if (tcp_in_slow_start(tp)) 1290 return tp->snd_cwnd < 2 * tp->max_packets_out; 1291 1292 return false; 1293} 1294 1295/* BBR congestion control needs pacing. 1296 * Same remark for SO_MAX_PACING_RATE. 1297 * sch_fq packet scheduler is efficiently handling pacing, 1298 * but is not always installed/used. 1299 * Return true if TCP stack should pace packets itself. 1300 */ 1301static inline bool tcp_needs_internal_pacing(const struct sock *sk) 1302{ 1303 return smp_load_acquire(&sk->sk_pacing_status) == SK_PACING_NEEDED; 1304} 1305 1306/* Estimates in how many jiffies next packet for this flow can be sent. 1307 * Scheduling a retransmit timer too early would be silly. 1308 */ 1309static inline unsigned long tcp_pacing_delay(const struct sock *sk) 1310{ 1311 s64 delay = tcp_sk(sk)->tcp_wstamp_ns - tcp_sk(sk)->tcp_clock_cache; 1312 1313 return delay > 0 ? nsecs_to_jiffies(delay) : 0; 1314} 1315 1316static inline void tcp_reset_xmit_timer(struct sock *sk, 1317 const int what, 1318 unsigned long when, 1319 const unsigned long max_when) 1320{ 1321 inet_csk_reset_xmit_timer(sk, what, when + tcp_pacing_delay(sk), 1322 max_when); 1323} 1324 1325/* Something is really bad, we could not queue an additional packet, 1326 * because qdisc is full or receiver sent a 0 window, or we are paced. 1327 * We do not want to add fuel to the fire, or abort too early, 1328 * so make sure the timer we arm now is at least 200ms in the future, 1329 * regardless of current icsk_rto value (as it could be ~2ms) 1330 */ 1331static inline unsigned long tcp_probe0_base(const struct sock *sk) 1332{ 1333 return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); 1334} 1335 1336/* Variant of inet_csk_rto_backoff() used for zero window probes */ 1337static inline unsigned long tcp_probe0_when(const struct sock *sk, 1338 unsigned long max_when) 1339{ 1340 u64 when = (u64)tcp_probe0_base(sk) << inet_csk(sk)->icsk_backoff; 1341 1342 return (unsigned long)min_t(u64, when, max_when); 1343} 1344 1345static inline void tcp_check_probe_timer(struct sock *sk) 1346{ 1347 if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) 1348 tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, 1349 tcp_probe0_base(sk), TCP_RTO_MAX); 1350} 1351 1352static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) 1353{ 1354 tp->snd_wl1 = seq; 1355} 1356 1357static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) 1358{ 1359 tp->snd_wl1 = seq; 1360} 1361 1362/* 1363 * Calculate(/check) TCP checksum 1364 */ 1365static inline __sum16 tcp_v4_check(int len, __be32 saddr, 1366 __be32 daddr, __wsum base) 1367{ 1368 return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_TCP, base); 1369} 1370 1371static inline bool tcp_checksum_complete(struct sk_buff *skb) 1372{ 1373 return !skb_csum_unnecessary(skb) && 1374 __skb_checksum_complete(skb); 1375} 1376 1377bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb); 1378int tcp_filter(struct sock *sk, struct sk_buff *skb); 1379void tcp_set_state(struct sock *sk, int state); 1380void tcp_done(struct sock *sk); 1381int tcp_abort(struct sock *sk, int err); 1382 1383static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) 1384{ 1385 rx_opt->dsack = 0; 1386 rx_opt->num_sacks = 0; 1387} 1388 1389void tcp_cwnd_restart(struct sock *sk, s32 delta); 1390 1391static inline void tcp_slow_start_after_idle_check(struct sock *sk) 1392{ 1393 const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; 1394 struct tcp_sock *tp = tcp_sk(sk); 1395 s32 delta; 1396 1397 if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle) || 1398 tp->packets_out || ca_ops->cong_control) 1399 return; 1400 delta = tcp_jiffies32 - tp->lsndtime; 1401 if (delta > inet_csk(sk)->icsk_rto) 1402 tcp_cwnd_restart(sk, delta); 1403} 1404 1405/* Determine a window scaling and initial window to offer. */ 1406void tcp_select_initial_window(const struct sock *sk, int __space, 1407 __u32 mss, __u32 *rcv_wnd, 1408 __u32 *window_clamp, int wscale_ok, 1409 __u8 *rcv_wscale, __u32 init_rcv_wnd); 1410 1411static inline int tcp_win_from_space(const struct sock *sk, int space) 1412{ 1413 int tcp_adv_win_scale = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_adv_win_scale); 1414 1415 return tcp_adv_win_scale <= 0 ? 1416 (space>>(-tcp_adv_win_scale)) : 1417 space - (space>>tcp_adv_win_scale); 1418} 1419 1420/* Note: caller must be prepared to deal with negative returns */ 1421static inline int tcp_space(const struct sock *sk) 1422{ 1423 return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - 1424 READ_ONCE(sk->sk_backlog.len) - 1425 atomic_read(&sk->sk_rmem_alloc)); 1426} 1427 1428static inline int tcp_full_space(const struct sock *sk) 1429{ 1430 return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); 1431} 1432 1433void tcp_cleanup_rbuf(struct sock *sk, int copied); 1434 1435/* We provision sk_rcvbuf around 200% of sk_rcvlowat. 1436 * If 87.5 % (7/8) of the space has been consumed, we want to override 1437 * SO_RCVLOWAT constraint, since we are receiving skbs with too small 1438 * len/truesize ratio. 1439 */ 1440static inline bool tcp_rmem_pressure(const struct sock *sk) 1441{ 1442 int rcvbuf, threshold; 1443 1444 if (tcp_under_memory_pressure(sk)) 1445 return true; 1446 1447 rcvbuf = READ_ONCE(sk->sk_rcvbuf); 1448 threshold = rcvbuf - (rcvbuf >> 3); 1449 1450 return atomic_read(&sk->sk_rmem_alloc) > threshold; 1451} 1452 1453extern void tcp_openreq_init_rwin(struct request_sock *req, 1454 const struct sock *sk_listener, 1455 const struct dst_entry *dst); 1456 1457void tcp_enter_memory_pressure(struct sock *sk); 1458void tcp_leave_memory_pressure(struct sock *sk); 1459 1460static inline int keepalive_intvl_when(const struct tcp_sock *tp) 1461{ 1462 struct net *net = sock_net((struct sock *)tp); 1463 int val; 1464 1465 /* Paired with WRITE_ONCE() in tcp_sock_set_keepintvl() 1466 * and do_tcp_setsockopt(). 1467 */ 1468 val = READ_ONCE(tp->keepalive_intvl); 1469 1470 return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); 1471} 1472 1473static inline int keepalive_time_when(const struct tcp_sock *tp) 1474{ 1475 struct net *net = sock_net((struct sock *)tp); 1476 int val; 1477 1478 /* Paired with WRITE_ONCE() in tcp_sock_set_keepidle_locked() */ 1479 val = READ_ONCE(tp->keepalive_time); 1480 1481 return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); 1482} 1483 1484static inline int keepalive_probes(const struct tcp_sock *tp) 1485{ 1486 struct net *net = sock_net((struct sock *)tp); 1487 int val; 1488 1489 /* Paired with WRITE_ONCE() in tcp_sock_set_keepcnt() 1490 * and do_tcp_setsockopt(). 1491 */ 1492 val = READ_ONCE(tp->keepalive_probes); 1493 1494 return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_probes); 1495} 1496 1497static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) 1498{ 1499 const struct inet_connection_sock *icsk = &tp->inet_conn; 1500 1501 return min_t(u32, tcp_jiffies32 - icsk->icsk_ack.lrcvtime, 1502 tcp_jiffies32 - tp->rcv_tstamp); 1503} 1504 1505static inline int tcp_fin_time(const struct sock *sk) 1506{ 1507 int fin_timeout = tcp_sk(sk)->linger2 ? : 1508 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fin_timeout); 1509 const int rto = inet_csk(sk)->icsk_rto; 1510 1511 if (fin_timeout < (rto << 2) - (rto >> 1)) 1512 fin_timeout = (rto << 2) - (rto >> 1); 1513 1514 return fin_timeout; 1515} 1516 1517static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, 1518 int paws_win) 1519{ 1520 if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) 1521 return true; 1522 if (unlikely(!time_before32(ktime_get_seconds(), 1523 rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS))) 1524 return true; 1525 /* 1526 * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, 1527 * then following tcp messages have valid values. Ignore 0 value, 1528 * or else 'negative' tsval might forbid us to accept their packets. 1529 */ 1530 if (!rx_opt->ts_recent) 1531 return true; 1532 return false; 1533} 1534 1535static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, 1536 int rst) 1537{ 1538 if (tcp_paws_check(rx_opt, 0)) 1539 return false; 1540 1541 /* RST segments are not recommended to carry timestamp, 1542 and, if they do, it is recommended to ignore PAWS because 1543 "their cleanup function should take precedence over timestamps." 1544 Certainly, it is mistake. It is necessary to understand the reasons 1545 of this constraint to relax it: if peer reboots, clock may go 1546 out-of-sync and half-open connections will not be reset. 1547 Actually, the problem would be not existing if all 1548 the implementations followed draft about maintaining clock 1549 via reboots. Linux-2.2 DOES NOT! 1550 1551 However, we can relax time bounds for RST segments to MSL. 1552 */ 1553 if (rst && !time_before32(ktime_get_seconds(), 1554 rx_opt->ts_recent_stamp + TCP_PAWS_MSL)) 1555 return false; 1556 return true; 1557} 1558 1559bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, 1560 int mib_idx, u32 *last_oow_ack_time); 1561 1562static inline void tcp_mib_init(struct net *net) 1563{ 1564 /* See RFC 2012 */ 1565 TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); 1566 TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); 1567 TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); 1568 TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); 1569} 1570 1571/* from STCP */ 1572static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) 1573{ 1574 tp->lost_skb_hint = NULL; 1575} 1576 1577static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) 1578{ 1579 tcp_clear_retrans_hints_partial(tp); 1580 tp->retransmit_skb_hint = NULL; 1581} 1582 1583union tcp_md5_addr { 1584 struct in_addr a4; 1585#if IS_ENABLED(CONFIG_IPV6) 1586 struct in6_addr a6; 1587#endif 1588}; 1589 1590/* - key database */ 1591struct tcp_md5sig_key { 1592 struct hlist_node node; 1593 u8 keylen; 1594 u8 family; /* AF_INET or AF_INET6 */ 1595 u8 prefixlen; 1596 union tcp_md5_addr addr; 1597 int l3index; /* set if key added with L3 scope */ 1598 u8 key[TCP_MD5SIG_MAXKEYLEN]; 1599 struct rcu_head rcu; 1600}; 1601 1602/* - sock block */ 1603struct tcp_md5sig_info { 1604 struct hlist_head head; 1605 struct rcu_head rcu; 1606}; 1607 1608/* - pseudo header */ 1609struct tcp4_pseudohdr { 1610 __be32 saddr; 1611 __be32 daddr; 1612 __u8 pad; 1613 __u8 protocol; 1614 __be16 len; 1615}; 1616 1617struct tcp6_pseudohdr { 1618 struct in6_addr saddr; 1619 struct in6_addr daddr; 1620 __be32 len; 1621 __be32 protocol; /* including padding */ 1622}; 1623 1624union tcp_md5sum_block { 1625 struct tcp4_pseudohdr ip4; 1626#if IS_ENABLED(CONFIG_IPV6) 1627 struct tcp6_pseudohdr ip6; 1628#endif 1629}; 1630 1631/* - pool: digest algorithm, hash description and scratch buffer */ 1632struct tcp_md5sig_pool { 1633 struct ahash_request *md5_req; 1634 void *scratch; 1635}; 1636 1637/* - functions */ 1638int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, 1639 const struct sock *sk, const struct sk_buff *skb); 1640int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, 1641 int family, u8 prefixlen, int l3index, 1642 const u8 *newkey, u8 newkeylen, gfp_t gfp); 1643int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, 1644 int family, u8 prefixlen, int l3index); 1645struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, 1646 const struct sock *addr_sk); 1647 1648#ifdef CONFIG_TCP_MD5SIG 1649#include <linux/jump_label.h> 1650extern struct static_key_false tcp_md5_needed; 1651struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, 1652 const union tcp_md5_addr *addr, 1653 int family); 1654static inline struct tcp_md5sig_key * 1655tcp_md5_do_lookup(const struct sock *sk, int l3index, 1656 const union tcp_md5_addr *addr, int family) 1657{ 1658 if (!static_branch_unlikely(&tcp_md5_needed)) 1659 return NULL; 1660 return __tcp_md5_do_lookup(sk, l3index, addr, family); 1661} 1662 1663#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) 1664#else 1665static inline struct tcp_md5sig_key * 1666tcp_md5_do_lookup(const struct sock *sk, int l3index, 1667 const union tcp_md5_addr *addr, int family) 1668{ 1669 return NULL; 1670} 1671#define tcp_twsk_md5_key(twsk) NULL 1672#endif 1673 1674bool tcp_alloc_md5sig_pool(void); 1675 1676struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); 1677static inline void tcp_put_md5sig_pool(void) 1678{ 1679 local_bh_enable(); 1680} 1681 1682int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *, 1683 unsigned int header_len); 1684int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, 1685 const struct tcp_md5sig_key *key); 1686 1687/* From tcp_fastopen.c */ 1688void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, 1689 struct tcp_fastopen_cookie *cookie); 1690void tcp_fastopen_cache_set(struct sock *sk, u16 mss, 1691 struct tcp_fastopen_cookie *cookie, bool syn_lost, 1692 u16 try_exp); 1693struct tcp_fastopen_request { 1694 /* Fast Open cookie. Size 0 means a cookie request */ 1695 struct tcp_fastopen_cookie cookie; 1696 struct msghdr *data; /* data in MSG_FASTOPEN */ 1697 size_t size; 1698 int copied; /* queued in tcp_connect() */ 1699 struct ubuf_info *uarg; 1700}; 1701void tcp_free_fastopen_req(struct tcp_sock *tp); 1702void tcp_fastopen_destroy_cipher(struct sock *sk); 1703void tcp_fastopen_ctx_destroy(struct net *net); 1704int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, 1705 void *primary_key, void *backup_key); 1706int tcp_fastopen_get_cipher(struct net *net, struct inet_connection_sock *icsk, 1707 u64 *key); 1708void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); 1709struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, 1710 struct request_sock *req, 1711 struct tcp_fastopen_cookie *foc, 1712 const struct dst_entry *dst); 1713void tcp_fastopen_init_key_once(struct net *net); 1714bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, 1715 struct tcp_fastopen_cookie *cookie); 1716bool tcp_fastopen_defer_connect(struct sock *sk, int *err); 1717#define TCP_FASTOPEN_KEY_LENGTH sizeof(siphash_key_t) 1718#define TCP_FASTOPEN_KEY_MAX 2 1719#define TCP_FASTOPEN_KEY_BUF_LENGTH \ 1720 (TCP_FASTOPEN_KEY_LENGTH * TCP_FASTOPEN_KEY_MAX) 1721 1722/* Fastopen key context */ 1723struct tcp_fastopen_context { 1724 siphash_key_t key[TCP_FASTOPEN_KEY_MAX]; 1725 int num; 1726 struct rcu_head rcu; 1727}; 1728 1729extern unsigned int sysctl_tcp_fastopen_blackhole_timeout; 1730void tcp_fastopen_active_disable(struct sock *sk); 1731bool tcp_fastopen_active_should_disable(struct sock *sk); 1732void tcp_fastopen_active_disable_ofo_check(struct sock *sk); 1733void tcp_fastopen_active_detect_blackhole(struct sock *sk, bool expired); 1734 1735/* Caller needs to wrap with rcu_read_(un)lock() */ 1736static inline 1737struct tcp_fastopen_context *tcp_fastopen_get_ctx(const struct sock *sk) 1738{ 1739 struct tcp_fastopen_context *ctx; 1740 1741 ctx = rcu_dereference(inet_csk(sk)->icsk_accept_queue.fastopenq.ctx); 1742 if (!ctx) 1743 ctx = rcu_dereference(sock_net(sk)->ipv4.tcp_fastopen_ctx); 1744 return ctx; 1745} 1746 1747static inline 1748bool tcp_fastopen_cookie_match(const struct tcp_fastopen_cookie *foc, 1749 const struct tcp_fastopen_cookie *orig) 1750{ 1751 if (orig->len == TCP_FASTOPEN_COOKIE_SIZE && 1752 orig->len == foc->len && 1753 !memcmp(orig->val, foc->val, foc->len)) 1754 return true; 1755 return false; 1756} 1757 1758static inline 1759int tcp_fastopen_context_len(const struct tcp_fastopen_context *ctx) 1760{ 1761 return ctx->num; 1762} 1763 1764/* Latencies incurred by various limits for a sender. They are 1765 * chronograph-like stats that are mutually exclusive. 1766 */ 1767enum tcp_chrono { 1768 TCP_CHRONO_UNSPEC, 1769 TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ 1770 TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ 1771 TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ 1772 __TCP_CHRONO_MAX, 1773}; 1774 1775void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); 1776void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); 1777 1778/* This helper is needed, because skb->tcp_tsorted_anchor uses 1779 * the same memory storage than skb->destructor/_skb_refdst 1780 */ 1781static inline void tcp_skb_tsorted_anchor_cleanup(struct sk_buff *skb) 1782{ 1783 skb->destructor = NULL; 1784 skb->_skb_refdst = 0UL; 1785} 1786 1787#define tcp_skb_tsorted_save(skb) { \ 1788 unsigned long _save = skb->_skb_refdst; \ 1789 skb->_skb_refdst = 0UL; 1790 1791#define tcp_skb_tsorted_restore(skb) \ 1792 skb->_skb_refdst = _save; \ 1793} 1794 1795void tcp_write_queue_purge(struct sock *sk); 1796 1797static inline struct sk_buff *tcp_rtx_queue_head(const struct sock *sk) 1798{ 1799 return skb_rb_first(&sk->tcp_rtx_queue); 1800} 1801 1802static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) 1803{ 1804 return skb_rb_last(&sk->tcp_rtx_queue); 1805} 1806 1807static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) 1808{ 1809 return skb_peek(&sk->sk_write_queue); 1810} 1811 1812static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) 1813{ 1814 return skb_peek_tail(&sk->sk_write_queue); 1815} 1816 1817#define tcp_for_write_queue_from_safe(skb, tmp, sk) \ 1818 skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) 1819 1820static inline struct sk_buff *tcp_send_head(const struct sock *sk) 1821{ 1822 return skb_peek(&sk->sk_write_queue); 1823} 1824 1825static inline bool tcp_skb_is_last(const struct sock *sk, 1826 const struct sk_buff *skb) 1827{ 1828 return skb_queue_is_last(&sk->sk_write_queue, skb); 1829} 1830 1831/** 1832 * tcp_write_queue_empty - test if any payload (or FIN) is available in write queue 1833 * @sk: socket 1834 * 1835 * Since the write queue can have a temporary empty skb in it, 1836 * we must not use "return skb_queue_empty(&sk->sk_write_queue)" 1837 */ 1838static inline bool tcp_write_queue_empty(const struct sock *sk) 1839{ 1840 const struct tcp_sock *tp = tcp_sk(sk); 1841 1842 return tp->write_seq == tp->snd_nxt; 1843} 1844 1845static inline bool tcp_rtx_queue_empty(const struct sock *sk) 1846{ 1847 return RB_EMPTY_ROOT(&sk->tcp_rtx_queue); 1848} 1849 1850static inline bool tcp_rtx_and_write_queues_empty(const struct sock *sk) 1851{ 1852 return tcp_rtx_queue_empty(sk) && tcp_write_queue_empty(sk); 1853} 1854 1855static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) 1856{ 1857 __skb_queue_tail(&sk->sk_write_queue, skb); 1858 1859 /* Queue it, remembering where we must start sending. */ 1860 if (sk->sk_write_queue.next == skb) 1861 tcp_chrono_start(sk, TCP_CHRONO_BUSY); 1862} 1863 1864/* Insert new before skb on the write queue of sk. */ 1865static inline void tcp_insert_write_queue_before(struct sk_buff *new, 1866 struct sk_buff *skb, 1867 struct sock *sk) 1868{ 1869 __skb_queue_before(&sk->sk_write_queue, skb, new); 1870} 1871 1872static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) 1873{ 1874 tcp_skb_tsorted_anchor_cleanup(skb); 1875 __skb_unlink(skb, &sk->sk_write_queue); 1876} 1877 1878void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb); 1879 1880static inline void tcp_rtx_queue_unlink(struct sk_buff *skb, struct sock *sk) 1881{ 1882 tcp_skb_tsorted_anchor_cleanup(skb); 1883 rb_erase(&skb->rbnode, &sk->tcp_rtx_queue); 1884} 1885 1886static inline void tcp_rtx_queue_unlink_and_free(struct sk_buff *skb, struct sock *sk) 1887{ 1888 list_del(&skb->tcp_tsorted_anchor); 1889 tcp_rtx_queue_unlink(skb, sk); 1890 sk_wmem_free_skb(sk, skb); 1891} 1892 1893static inline void tcp_push_pending_frames(struct sock *sk) 1894{ 1895 if (tcp_send_head(sk)) { 1896 struct tcp_sock *tp = tcp_sk(sk); 1897 1898 __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); 1899 } 1900} 1901 1902/* Start sequence of the skb just after the highest skb with SACKed 1903 * bit, valid only if sacked_out > 0 or when the caller has ensured 1904 * validity by itself. 1905 */ 1906static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) 1907{ 1908 if (!tp->sacked_out) 1909 return tp->snd_una; 1910 1911 if (tp->highest_sack == NULL) 1912 return tp->snd_nxt; 1913 1914 return TCP_SKB_CB(tp->highest_sack)->seq; 1915} 1916 1917static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) 1918{ 1919 tcp_sk(sk)->highest_sack = skb_rb_next(skb); 1920} 1921 1922static inline struct sk_buff *tcp_highest_sack(struct sock *sk) 1923{ 1924 return tcp_sk(sk)->highest_sack; 1925} 1926 1927static inline void tcp_highest_sack_reset(struct sock *sk) 1928{ 1929 tcp_sk(sk)->highest_sack = tcp_rtx_queue_head(sk); 1930} 1931 1932/* Called when old skb is about to be deleted and replaced by new skb */ 1933static inline void tcp_highest_sack_replace(struct sock *sk, 1934 struct sk_buff *old, 1935 struct sk_buff *new) 1936{ 1937 if (old == tcp_highest_sack(sk)) 1938 tcp_sk(sk)->highest_sack = new; 1939} 1940 1941/* This helper checks if socket has IP_TRANSPARENT set */ 1942static inline bool inet_sk_transparent(const struct sock *sk) 1943{ 1944 switch (sk->sk_state) { 1945 case TCP_TIME_WAIT: 1946 return inet_twsk(sk)->tw_transparent; 1947 case TCP_NEW_SYN_RECV: 1948 return inet_rsk(inet_reqsk(sk))->no_srccheck; 1949 } 1950 return inet_sk(sk)->transparent; 1951} 1952 1953/* Determines whether this is a thin stream (which may suffer from 1954 * increased latency). Used to trigger latency-reducing mechanisms. 1955 */ 1956static inline bool tcp_stream_is_thin(struct tcp_sock *tp) 1957{ 1958 return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); 1959} 1960 1961/* /proc */ 1962enum tcp_seq_states { 1963 TCP_SEQ_STATE_LISTENING, 1964 TCP_SEQ_STATE_ESTABLISHED, 1965}; 1966 1967void *tcp_seq_start(struct seq_file *seq, loff_t *pos); 1968void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos); 1969void tcp_seq_stop(struct seq_file *seq, void *v); 1970 1971struct tcp_seq_afinfo { 1972 sa_family_t family; 1973}; 1974 1975struct tcp_iter_state { 1976 struct seq_net_private p; 1977 enum tcp_seq_states state; 1978 struct sock *syn_wait_sk; 1979 struct tcp_seq_afinfo *bpf_seq_afinfo; 1980 int bucket, offset, sbucket, num; 1981 loff_t last_pos; 1982}; 1983 1984extern struct request_sock_ops tcp_request_sock_ops; 1985extern struct request_sock_ops tcp6_request_sock_ops; 1986 1987void tcp_v4_destroy_sock(struct sock *sk); 1988 1989struct sk_buff *tcp_gso_segment(struct sk_buff *skb, 1990 netdev_features_t features); 1991struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb); 1992INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *skb, int thoff)); 1993INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)); 1994INDIRECT_CALLABLE_DECLARE(int tcp6_gro_complete(struct sk_buff *skb, int thoff)); 1995INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)); 1996int tcp_gro_complete(struct sk_buff *skb); 1997 1998void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); 1999 2000static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) 2001{ 2002 struct net *net = sock_net((struct sock *)tp); 2003 u32 val; 2004 2005 val = READ_ONCE(tp->notsent_lowat); 2006 2007 return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); 2008} 2009 2010/* @wake is one when sk_stream_write_space() calls us. 2011 * This sends EPOLLOUT only if notsent_bytes is half the limit. 2012 * This mimics the strategy used in sock_def_write_space(). 2013 */ 2014static inline bool tcp_stream_memory_free(const struct sock *sk, int wake) 2015{ 2016 const struct tcp_sock *tp = tcp_sk(sk); 2017 u32 notsent_bytes = READ_ONCE(tp->write_seq) - 2018 READ_ONCE(tp->snd_nxt); 2019 2020 return (notsent_bytes << wake) < tcp_notsent_lowat(tp); 2021} 2022 2023#ifdef CONFIG_PROC_FS 2024int tcp4_proc_init(void); 2025void tcp4_proc_exit(void); 2026#endif 2027 2028int tcp_rtx_synack(const struct sock *sk, struct request_sock *req); 2029int tcp_conn_request(struct request_sock_ops *rsk_ops, 2030 const struct tcp_request_sock_ops *af_ops, 2031 struct sock *sk, struct sk_buff *skb); 2032 2033/* TCP af-specific functions */ 2034struct tcp_sock_af_ops { 2035#ifdef CONFIG_TCP_MD5SIG 2036 struct tcp_md5sig_key *(*md5_lookup) (const struct sock *sk, 2037 const struct sock *addr_sk); 2038 int (*calc_md5_hash)(char *location, 2039 const struct tcp_md5sig_key *md5, 2040 const struct sock *sk, 2041 const struct sk_buff *skb); 2042 int (*md5_parse)(struct sock *sk, 2043 int optname, 2044 sockptr_t optval, 2045 int optlen); 2046#endif 2047}; 2048 2049struct tcp_request_sock_ops { 2050 u16 mss_clamp; 2051#ifdef CONFIG_TCP_MD5SIG 2052 struct tcp_md5sig_key *(*req_md5_lookup)(const struct sock *sk, 2053 const struct sock *addr_sk); 2054 int (*calc_md5_hash) (char *location, 2055 const struct tcp_md5sig_key *md5, 2056 const struct sock *sk, 2057 const struct sk_buff *skb); 2058#endif 2059 void (*init_req)(struct request_sock *req, 2060 const struct sock *sk_listener, 2061 struct sk_buff *skb); 2062#ifdef CONFIG_SYN_COOKIES 2063 __u32 (*cookie_init_seq)(const struct sk_buff *skb, 2064 __u16 *mss); 2065#endif 2066 struct dst_entry *(*route_req)(const struct sock *sk, struct flowi *fl, 2067 const struct request_sock *req); 2068 u32 (*init_seq)(const struct sk_buff *skb); 2069 u32 (*init_ts_off)(const struct net *net, const struct sk_buff *skb); 2070 int (*send_synack)(const struct sock *sk, struct dst_entry *dst, 2071 struct flowi *fl, struct request_sock *req, 2072 struct tcp_fastopen_cookie *foc, 2073 enum tcp_synack_type synack_type, 2074 struct sk_buff *syn_skb); 2075}; 2076 2077extern const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops; 2078#if IS_ENABLED(CONFIG_IPV6) 2079extern const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops; 2080#endif 2081 2082#ifdef CONFIG_SYN_COOKIES 2083static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, 2084 const struct sock *sk, struct sk_buff *skb, 2085 __u16 *mss) 2086{ 2087 tcp_synq_overflow(sk); 2088 __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); 2089 return ops->cookie_init_seq(skb, mss); 2090} 2091#else 2092static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, 2093 const struct sock *sk, struct sk_buff *skb, 2094 __u16 *mss) 2095{ 2096 return 0; 2097} 2098#endif 2099 2100int tcpv4_offload_init(void); 2101 2102void tcp_v4_init(void); 2103void tcp_init(void); 2104 2105/* tcp_recovery.c */ 2106void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb); 2107void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced); 2108extern s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, 2109 u32 reo_wnd); 2110extern bool tcp_rack_mark_lost(struct sock *sk); 2111extern void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, 2112 u64 xmit_time); 2113extern void tcp_rack_reo_timeout(struct sock *sk); 2114extern void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs); 2115 2116/* At how many usecs into the future should the RTO fire? */ 2117static inline s64 tcp_rto_delta_us(const struct sock *sk) 2118{ 2119 const struct sk_buff *skb = tcp_rtx_queue_head(sk); 2120 u32 rto = inet_csk(sk)->icsk_rto; 2121 u64 rto_time_stamp_us = tcp_skb_timestamp_us(skb) + jiffies_to_usecs(rto); 2122 2123 return rto_time_stamp_us - tcp_sk(sk)->tcp_mstamp; 2124} 2125 2126/* 2127 * Save and compile IPv4 options, return a pointer to it 2128 */ 2129static inline struct ip_options_rcu *tcp_v4_save_options(struct net *net, 2130 struct sk_buff *skb) 2131{ 2132 const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; 2133 struct ip_options_rcu *dopt = NULL; 2134 2135 if (opt->optlen) { 2136 int opt_size = sizeof(*dopt) + opt->optlen; 2137 2138 dopt = kmalloc(opt_size, GFP_ATOMIC); 2139 if (dopt && __ip_options_echo(net, &dopt->opt, skb, opt)) { 2140 kfree(dopt); 2141 dopt = NULL; 2142 } 2143 } 2144 return dopt; 2145} 2146 2147/* locally generated TCP pure ACKs have skb->truesize == 2 2148 * (check tcp_send_ack() in net/ipv4/tcp_output.c ) 2149 * This is much faster than dissecting the packet to find out. 2150 * (Think of GRE encapsulations, IPv4, IPv6, ...) 2151 */ 2152static inline bool skb_is_tcp_pure_ack(const struct sk_buff *skb) 2153{ 2154 return skb->truesize == 2; 2155} 2156 2157static inline void skb_set_tcp_pure_ack(struct sk_buff *skb) 2158{ 2159 skb->truesize = 2; 2160} 2161 2162static inline int tcp_inq(struct sock *sk) 2163{ 2164 struct tcp_sock *tp = tcp_sk(sk); 2165 int answ; 2166 2167 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { 2168 answ = 0; 2169 } else if (sock_flag(sk, SOCK_URGINLINE) || 2170 !tp->urg_data || 2171 before(tp->urg_seq, tp->copied_seq) || 2172 !before(tp->urg_seq, tp->rcv_nxt)) { 2173 2174 answ = tp->rcv_nxt - tp->copied_seq; 2175 2176 /* Subtract 1, if FIN was received */ 2177 if (answ && sock_flag(sk, SOCK_DONE)) 2178 answ--; 2179 } else { 2180 answ = tp->urg_seq - tp->copied_seq; 2181 } 2182 2183 return answ; 2184} 2185 2186int tcp_peek_len(struct socket *sock); 2187 2188static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) 2189{ 2190 u16 segs_in; 2191 2192 segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); 2193 tp->segs_in += segs_in; 2194 if (skb->len > tcp_hdrlen(skb)) 2195 tp->data_segs_in += segs_in; 2196} 2197 2198/* 2199 * TCP listen path runs lockless. 2200 * We forced "struct sock" to be const qualified to make sure 2201 * we don't modify one of its field by mistake. 2202 * Here, we increment sk_drops which is an atomic_t, so we can safely 2203 * make sock writable again. 2204 */ 2205static inline void tcp_listendrop(const struct sock *sk) 2206{ 2207 atomic_inc(&((struct sock *)sk)->sk_drops); 2208 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); 2209} 2210 2211enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer); 2212 2213/* 2214 * Interface for adding Upper Level Protocols over TCP 2215 */ 2216 2217#define TCP_ULP_NAME_MAX 16 2218#define TCP_ULP_MAX 128 2219#define TCP_ULP_BUF_MAX (TCP_ULP_NAME_MAX*TCP_ULP_MAX) 2220 2221struct tcp_ulp_ops { 2222 struct list_head list; 2223 2224 /* initialize ulp */ 2225 int (*init)(struct sock *sk); 2226 /* update ulp */ 2227 void (*update)(struct sock *sk, struct proto *p, 2228 void (*write_space)(struct sock *sk)); 2229 /* cleanup ulp */ 2230 void (*release)(struct sock *sk); 2231 /* diagnostic */ 2232 int (*get_info)(const struct sock *sk, struct sk_buff *skb); 2233 size_t (*get_info_size)(const struct sock *sk); 2234 /* clone ulp */ 2235 void (*clone)(const struct request_sock *req, struct sock *newsk, 2236 const gfp_t priority); 2237 2238 char name[TCP_ULP_NAME_MAX]; 2239 struct module *owner; 2240}; 2241int tcp_register_ulp(struct tcp_ulp_ops *type); 2242void tcp_unregister_ulp(struct tcp_ulp_ops *type); 2243int tcp_set_ulp(struct sock *sk, const char *name); 2244void tcp_get_available_ulp(char *buf, size_t len); 2245void tcp_cleanup_ulp(struct sock *sk); 2246void tcp_update_ulp(struct sock *sk, struct proto *p, 2247 void (*write_space)(struct sock *sk)); 2248 2249#define MODULE_ALIAS_TCP_ULP(name) \ 2250 __MODULE_INFO(alias, alias_userspace, name); \ 2251 __MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name) 2252 2253struct sk_msg; 2254struct sk_psock; 2255 2256#ifdef CONFIG_BPF_STREAM_PARSER 2257struct proto *tcp_bpf_get_proto(struct sock *sk, struct sk_psock *psock); 2258void tcp_bpf_clone(const struct sock *sk, struct sock *newsk); 2259#else 2260static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk) 2261{ 2262} 2263#endif /* CONFIG_BPF_STREAM_PARSER */ 2264 2265#ifdef CONFIG_NET_SOCK_MSG 2266int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg, u32 bytes, 2267 int flags); 2268int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock, 2269 struct msghdr *msg, int len, int flags); 2270#endif /* CONFIG_NET_SOCK_MSG */ 2271 2272#ifdef CONFIG_CGROUP_BPF 2273static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, 2274 struct sk_buff *skb, 2275 unsigned int end_offset) 2276{ 2277 skops->skb = skb; 2278 skops->skb_data_end = skb->data + end_offset; 2279} 2280#else 2281static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, 2282 struct sk_buff *skb, 2283 unsigned int end_offset) 2284{ 2285} 2286#endif 2287 2288/* Call BPF_SOCK_OPS program that returns an int. If the return value 2289 * is < 0, then the BPF op failed (for example if the loaded BPF 2290 * program does not support the chosen operation or there is no BPF 2291 * program loaded). 2292 */ 2293#ifdef CONFIG_BPF 2294static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) 2295{ 2296 struct bpf_sock_ops_kern sock_ops; 2297 int ret; 2298 2299 memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); 2300 if (sk_fullsock(sk)) { 2301 sock_ops.is_fullsock = 1; 2302 sock_owned_by_me(sk); 2303 } 2304 2305 sock_ops.sk = sk; 2306 sock_ops.op = op; 2307 if (nargs > 0) 2308 memcpy(sock_ops.args, args, nargs * sizeof(*args)); 2309 2310 ret = BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); 2311 if (ret == 0) 2312 ret = sock_ops.reply; 2313 else 2314 ret = -1; 2315 return ret; 2316} 2317 2318static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) 2319{ 2320 u32 args[2] = {arg1, arg2}; 2321 2322 return tcp_call_bpf(sk, op, 2, args); 2323} 2324 2325static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, 2326 u32 arg3) 2327{ 2328 u32 args[3] = {arg1, arg2, arg3}; 2329 2330 return tcp_call_bpf(sk, op, 3, args); 2331} 2332 2333#else 2334static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) 2335{ 2336 return -EPERM; 2337} 2338 2339static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) 2340{ 2341 return -EPERM; 2342} 2343 2344static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, 2345 u32 arg3) 2346{ 2347 return -EPERM; 2348} 2349 2350#endif 2351 2352static inline u32 tcp_timeout_init(struct sock *sk) 2353{ 2354 int timeout; 2355 2356 timeout = tcp_call_bpf(sk, BPF_SOCK_OPS_TIMEOUT_INIT, 0, NULL); 2357 2358 if (timeout <= 0) 2359 timeout = TCP_TIMEOUT_INIT; 2360 return timeout; 2361} 2362 2363static inline u32 tcp_rwnd_init_bpf(struct sock *sk) 2364{ 2365 int rwnd; 2366 2367 rwnd = tcp_call_bpf(sk, BPF_SOCK_OPS_RWND_INIT, 0, NULL); 2368 2369 if (rwnd < 0) 2370 rwnd = 0; 2371 return rwnd; 2372} 2373 2374static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) 2375{ 2376 return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN, 0, NULL) == 1); 2377} 2378 2379static inline void tcp_bpf_rtt(struct sock *sk) 2380{ 2381 if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_RTT_CB_FLAG)) 2382 tcp_call_bpf(sk, BPF_SOCK_OPS_RTT_CB, 0, NULL); 2383} 2384 2385#if IS_ENABLED(CONFIG_SMC) 2386extern struct static_key_false tcp_have_smc; 2387#endif 2388 2389#if IS_ENABLED(CONFIG_TLS_DEVICE) 2390void clean_acked_data_enable(struct inet_connection_sock *icsk, 2391 void (*cad)(struct sock *sk, u32 ack_seq)); 2392void clean_acked_data_disable(struct inet_connection_sock *icsk); 2393void clean_acked_data_flush(void); 2394#endif 2395 2396DECLARE_STATIC_KEY_FALSE(tcp_tx_delay_enabled); 2397static inline void tcp_add_tx_delay(struct sk_buff *skb, 2398 const struct tcp_sock *tp) 2399{ 2400 if (static_branch_unlikely(&tcp_tx_delay_enabled)) 2401 skb->skb_mstamp_ns += (u64)tp->tcp_tx_delay * NSEC_PER_USEC; 2402} 2403 2404/* Compute Earliest Departure Time for some control packets 2405 * like ACK or RST for TIME_WAIT or non ESTABLISHED sockets. 2406 */ 2407static inline u64 tcp_transmit_time(const struct sock *sk) 2408{ 2409 if (static_branch_unlikely(&tcp_tx_delay_enabled)) { 2410 u32 delay = (sk->sk_state == TCP_TIME_WAIT) ? 2411 tcp_twsk(sk)->tw_tx_delay : tcp_sk(sk)->tcp_tx_delay; 2412 2413 return tcp_clock_ns() + (u64)delay * NSEC_PER_USEC; 2414 } 2415 return 0; 2416} 2417 2418#endif /* _TCP_H */ 2419