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 protocol. 8 * 9 * Version: @(#)tcp.h 1.0.2 04/28/93 10 * 11 * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 */ 13 #ifndef _LINUX_TCP_H 14 #define _LINUX_TCP_H 15 16 17 #include <linux/skbuff.h> 18 #include <linux/win_minmax.h> 19 #include <linux/android_kabi.h> 20 #include <net/sock.h> 21 #include <net/inet_connection_sock.h> 22 #include <net/inet_timewait_sock.h> 23 #include <uapi/linux/tcp.h> 24 tcp_hdr(const struct sk_buff * skb)25 static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb) 26 { 27 return (struct tcphdr *)skb_transport_header(skb); 28 } 29 __tcp_hdrlen(const struct tcphdr * th)30 static inline unsigned int __tcp_hdrlen(const struct tcphdr *th) 31 { 32 return th->doff * 4; 33 } 34 tcp_hdrlen(const struct sk_buff * skb)35 static inline unsigned int tcp_hdrlen(const struct sk_buff *skb) 36 { 37 return __tcp_hdrlen(tcp_hdr(skb)); 38 } 39 inner_tcp_hdr(const struct sk_buff * skb)40 static inline struct tcphdr *inner_tcp_hdr(const struct sk_buff *skb) 41 { 42 return (struct tcphdr *)skb_inner_transport_header(skb); 43 } 44 inner_tcp_hdrlen(const struct sk_buff * skb)45 static inline unsigned int inner_tcp_hdrlen(const struct sk_buff *skb) 46 { 47 return inner_tcp_hdr(skb)->doff * 4; 48 } 49 tcp_optlen(const struct sk_buff * skb)50 static inline unsigned int tcp_optlen(const struct sk_buff *skb) 51 { 52 return (tcp_hdr(skb)->doff - 5) * 4; 53 } 54 55 /* TCP Fast Open */ 56 #define TCP_FASTOPEN_COOKIE_MIN 4 /* Min Fast Open Cookie size in bytes */ 57 #define TCP_FASTOPEN_COOKIE_MAX 16 /* Max Fast Open Cookie size in bytes */ 58 #define TCP_FASTOPEN_COOKIE_SIZE 8 /* the size employed by this impl. */ 59 60 /* TCP Fast Open Cookie as stored in memory */ 61 struct tcp_fastopen_cookie { 62 __le64 val[DIV_ROUND_UP(TCP_FASTOPEN_COOKIE_MAX, sizeof(u64))]; 63 s8 len; 64 bool exp; /* In RFC6994 experimental option format */ 65 }; 66 67 /* This defines a selective acknowledgement block. */ 68 struct tcp_sack_block_wire { 69 __be32 start_seq; 70 __be32 end_seq; 71 }; 72 73 struct tcp_sack_block { 74 u32 start_seq; 75 u32 end_seq; 76 }; 77 78 /*These are used to set the sack_ok field in struct tcp_options_received */ 79 #define TCP_SACK_SEEN (1 << 0) /*1 = peer is SACK capable, */ 80 #define TCP_DSACK_SEEN (1 << 2) /*1 = DSACK was received from peer*/ 81 82 struct tcp_options_received { 83 /* PAWS/RTTM data */ 84 int ts_recent_stamp;/* Time we stored ts_recent (for aging) */ 85 u32 ts_recent; /* Time stamp to echo next */ 86 u32 rcv_tsval; /* Time stamp value */ 87 u32 rcv_tsecr; /* Time stamp echo reply */ 88 u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */ 89 tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */ 90 dsack : 1, /* D-SACK is scheduled */ 91 wscale_ok : 1, /* Wscale seen on SYN packet */ 92 sack_ok : 3, /* SACK seen on SYN packet */ 93 smc_ok : 1, /* SMC seen on SYN packet */ 94 snd_wscale : 4, /* Window scaling received from sender */ 95 rcv_wscale : 4; /* Window scaling to send to receiver */ 96 u8 saw_unknown:1, /* Received unknown option */ 97 unused:7; 98 u8 num_sacks; /* Number of SACK blocks */ 99 u16 user_mss; /* mss requested by user in ioctl */ 100 u16 mss_clamp; /* Maximal mss, negotiated at connection setup */ 101 }; 102 tcp_clear_options(struct tcp_options_received * rx_opt)103 static inline void tcp_clear_options(struct tcp_options_received *rx_opt) 104 { 105 rx_opt->tstamp_ok = rx_opt->sack_ok = 0; 106 rx_opt->wscale_ok = rx_opt->snd_wscale = 0; 107 #if IS_ENABLED(CONFIG_SMC) 108 rx_opt->smc_ok = 0; 109 #endif 110 } 111 112 /* This is the max number of SACKS that we'll generate and process. It's safe 113 * to increase this, although since: 114 * size = TCPOLEN_SACK_BASE_ALIGNED (4) + n * TCPOLEN_SACK_PERBLOCK (8) 115 * only four options will fit in a standard TCP header */ 116 #define TCP_NUM_SACKS 4 117 118 struct tcp_request_sock_ops; 119 120 struct tcp_request_sock { 121 struct inet_request_sock req; 122 const struct tcp_request_sock_ops *af_specific; 123 u64 snt_synack; /* first SYNACK sent time */ 124 bool tfo_listener; 125 bool is_mptcp; 126 #if IS_ENABLED(CONFIG_MPTCP) 127 bool drop_req; 128 #endif 129 u32 txhash; 130 u32 rcv_isn; 131 u32 snt_isn; 132 u32 ts_off; 133 u32 last_oow_ack_time; /* last SYNACK */ 134 u32 rcv_nxt; /* the ack # by SYNACK. For 135 * FastOpen it's the seq# 136 * after data-in-SYN. 137 */ 138 u8 syn_tos; 139 }; 140 tcp_rsk(const struct request_sock * req)141 static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req) 142 { 143 return (struct tcp_request_sock *)req; 144 } 145 146 struct tcp_sock { 147 /* inet_connection_sock has to be the first member of tcp_sock */ 148 struct inet_connection_sock inet_conn; 149 u16 tcp_header_len; /* Bytes of tcp header to send */ 150 u16 gso_segs; /* Max number of segs per GSO packet */ 151 152 /* 153 * Header prediction flags 154 * 0x5?10 << 16 + snd_wnd in net byte order 155 */ 156 __be32 pred_flags; 157 158 /* 159 * RFC793 variables by their proper names. This means you can 160 * read the code and the spec side by side (and laugh ...) 161 * See RFC793 and RFC1122. The RFC writes these in capitals. 162 */ 163 u64 bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived 164 * sum(delta(rcv_nxt)), or how many bytes 165 * were acked. 166 */ 167 u32 segs_in; /* RFC4898 tcpEStatsPerfSegsIn 168 * total number of segments in. 169 */ 170 u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn 171 * total number of data segments in. 172 */ 173 u32 rcv_nxt; /* What we want to receive next */ 174 u32 copied_seq; /* Head of yet unread data */ 175 u32 rcv_wup; /* rcv_nxt on last window update sent */ 176 u32 snd_nxt; /* Next sequence we send */ 177 u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut 178 * The total number of segments sent. 179 */ 180 u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut 181 * total number of data segments sent. 182 */ 183 u64 bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut 184 * total number of data bytes sent. 185 */ 186 u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked 187 * sum(delta(snd_una)), or how many bytes 188 * were acked. 189 */ 190 u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups 191 * total number of DSACK blocks received 192 */ 193 u32 snd_una; /* First byte we want an ack for */ 194 u32 snd_sml; /* Last byte of the most recently transmitted small packet */ 195 u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ 196 u32 lsndtime; /* timestamp of last sent data packet (for restart window) */ 197 u32 last_oow_ack_time; /* timestamp of last out-of-window ACK */ 198 u32 compressed_ack_rcv_nxt; 199 200 u32 tsoffset; /* timestamp offset */ 201 202 struct list_head tsq_node; /* anchor in tsq_tasklet.head list */ 203 struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */ 204 205 u32 snd_wl1; /* Sequence for window update */ 206 u32 snd_wnd; /* The window we expect to receive */ 207 u32 max_window; /* Maximal window ever seen from peer */ 208 u32 mss_cache; /* Cached effective mss, not including SACKS */ 209 210 u32 window_clamp; /* Maximal window to advertise */ 211 u32 rcv_ssthresh; /* Current window clamp */ 212 213 /* Information of the most recently (s)acked skb */ 214 struct tcp_rack { 215 u64 mstamp; /* (Re)sent time of the skb */ 216 u32 rtt_us; /* Associated RTT */ 217 u32 end_seq; /* Ending TCP sequence of the skb */ 218 u32 last_delivered; /* tp->delivered at last reo_wnd adj */ 219 u8 reo_wnd_steps; /* Allowed reordering window */ 220 #define TCP_RACK_RECOVERY_THRESH 16 221 u8 reo_wnd_persist:5, /* No. of recovery since last adj */ 222 dsack_seen:1, /* Whether DSACK seen after last adj */ 223 advanced:1; /* mstamp advanced since last lost marking */ 224 } rack; 225 u16 advmss; /* Advertised MSS */ 226 u8 compressed_ack; 227 u8 dup_ack_counter:2, 228 tlp_retrans:1, /* TLP is a retransmission */ 229 unused:5; 230 u32 chrono_start; /* Start time in jiffies of a TCP chrono */ 231 u32 chrono_stat[3]; /* Time in jiffies for chrono_stat stats */ 232 u8 chrono_type:2, /* current chronograph type */ 233 rate_app_limited:1, /* rate_{delivered,interval_us} limited? */ 234 fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */ 235 fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */ 236 is_sack_reneg:1, /* in recovery from loss with SACK reneg? */ 237 fastopen_client_fail:2; /* reason why fastopen failed */ 238 u8 nonagle : 4,/* Disable Nagle algorithm? */ 239 thin_lto : 1,/* Use linear timeouts for thin streams */ 240 recvmsg_inq : 1,/* Indicate # of bytes in queue upon recvmsg */ 241 repair : 1, 242 frto : 1;/* F-RTO (RFC5682) activated in CA_Loss */ 243 u8 repair_queue; 244 u8 save_syn:2, /* Save headers of SYN packet */ 245 syn_data:1, /* SYN includes data */ 246 syn_fastopen:1, /* SYN includes Fast Open option */ 247 syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */ 248 syn_fastopen_ch:1, /* Active TFO re-enabling probe */ 249 syn_data_acked:1,/* data in SYN is acked by SYN-ACK */ 250 is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */ 251 u32 tlp_high_seq; /* snd_nxt at the time of TLP */ 252 253 u32 tcp_tx_delay; /* delay (in usec) added to TX packets */ 254 u64 tcp_wstamp_ns; /* departure time for next sent data packet */ 255 u64 tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */ 256 257 /* RTT measurement */ 258 u64 tcp_mstamp; /* most recent packet received/sent */ 259 u32 srtt_us; /* smoothed round trip time << 3 in usecs */ 260 u32 mdev_us; /* medium deviation */ 261 u32 mdev_max_us; /* maximal mdev for the last rtt period */ 262 u32 rttvar_us; /* smoothed mdev_max */ 263 u32 rtt_seq; /* sequence number to update rttvar */ 264 struct minmax rtt_min; 265 266 u32 packets_out; /* Packets which are "in flight" */ 267 u32 retrans_out; /* Retransmitted packets out */ 268 u32 max_packets_out; /* max packets_out in last window */ 269 /* ANDROID: 270 * max_packets_seq is really cwnd_usage_seq upstream, old name kept 271 * to preserve ABI due to changes in commit 49d429760df7 ("tcp: fix 272 * tcp_cwnd_validate() to not forget is_cwnd_limited") 273 */ 274 u32 max_packets_seq; /* right edge of cwnd usage tracking flight */ 275 276 u16 urg_data; /* Saved octet of OOB data and control flags */ 277 u8 ecn_flags; /* ECN status bits. */ 278 u8 keepalive_probes; /* num of allowed keep alive probes */ 279 u32 reordering; /* Packet reordering metric. */ 280 u32 reord_seen; /* number of data packet reordering events */ 281 u32 snd_up; /* Urgent pointer */ 282 283 /* 284 * Options received (usually on last packet, some only on SYN packets). 285 */ 286 struct tcp_options_received rx_opt; 287 288 /* 289 * Slow start and congestion control (see also Nagle, and Karn & Partridge) 290 */ 291 u32 snd_ssthresh; /* Slow start size threshold */ 292 u32 snd_cwnd; /* Sending congestion window */ 293 u32 snd_cwnd_cnt; /* Linear increase counter */ 294 u32 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */ 295 u32 snd_cwnd_used; 296 u32 snd_cwnd_stamp; 297 u32 prior_cwnd; /* cwnd right before starting loss recovery */ 298 u32 prr_delivered; /* Number of newly delivered packets to 299 * receiver in Recovery. */ 300 u32 prr_out; /* Total number of pkts sent during Recovery. */ 301 u32 delivered; /* Total data packets delivered incl. rexmits */ 302 u32 delivered_ce; /* Like the above but only ECE marked packets */ 303 u32 lost; /* Total data packets lost incl. rexmits */ 304 u32 app_limited; /* limited until "delivered" reaches this val */ 305 u64 first_tx_mstamp; /* start of window send phase */ 306 u64 delivered_mstamp; /* time we reached "delivered" */ 307 u32 rate_delivered; /* saved rate sample: packets delivered */ 308 u32 rate_interval_us; /* saved rate sample: time elapsed */ 309 310 u32 rcv_wnd; /* Current receiver window */ 311 u32 write_seq; /* Tail(+1) of data held in tcp send buffer */ 312 u32 notsent_lowat; /* TCP_NOTSENT_LOWAT */ 313 u32 pushed_seq; /* Last pushed seq, required to talk to windows */ 314 u32 lost_out; /* Lost packets */ 315 u32 sacked_out; /* SACK'd packets */ 316 317 struct hrtimer pacing_timer; 318 struct hrtimer compressed_ack_timer; 319 320 /* from STCP, retrans queue hinting */ 321 struct sk_buff* lost_skb_hint; 322 struct sk_buff *retransmit_skb_hint; 323 324 /* OOO segments go in this rbtree. Socket lock must be held. */ 325 struct rb_root out_of_order_queue; 326 struct sk_buff *ooo_last_skb; /* cache rb_last(out_of_order_queue) */ 327 328 /* SACKs data, these 2 need to be together (see tcp_options_write) */ 329 struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */ 330 struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/ 331 332 struct tcp_sack_block recv_sack_cache[4]; 333 334 struct sk_buff *highest_sack; /* skb just after the highest 335 * skb with SACKed bit set 336 * (validity guaranteed only if 337 * sacked_out > 0) 338 */ 339 340 int lost_cnt_hint; 341 342 u32 prior_ssthresh; /* ssthresh saved at recovery start */ 343 u32 high_seq; /* snd_nxt at onset of congestion */ 344 345 u32 retrans_stamp; /* Timestamp of the last retransmit, 346 * also used in SYN-SENT to remember stamp of 347 * the first SYN. */ 348 u32 undo_marker; /* snd_una upon a new recovery episode. */ 349 int undo_retrans; /* number of undoable retransmissions. */ 350 u64 bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans 351 * Total data bytes retransmitted 352 */ 353 u32 total_retrans; /* Total retransmits for entire connection */ 354 355 u32 urg_seq; /* Seq of received urgent pointer */ 356 unsigned int keepalive_time; /* time before keep alive takes place */ 357 unsigned int keepalive_intvl; /* time interval between keep alive probes */ 358 359 int linger2; 360 361 362 /* Sock_ops bpf program related variables */ 363 #ifdef CONFIG_BPF 364 u8 bpf_sock_ops_cb_flags; /* Control calling BPF programs 365 * values defined in uapi/linux/tcp.h 366 */ 367 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) (TP->bpf_sock_ops_cb_flags & ARG) 368 #else 369 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) 0 370 #endif 371 372 u16 timeout_rehash; /* Timeout-triggered rehash attempts */ 373 374 u32 rcv_ooopack; /* Received out-of-order packets, for tcpinfo */ 375 376 /* Receiver side RTT estimation */ 377 u32 rcv_rtt_last_tsecr; 378 struct { 379 u32 rtt_us; 380 u32 seq; 381 u64 time; 382 } rcv_rtt_est; 383 384 /* Receiver queue space */ 385 struct { 386 u32 space; 387 u32 seq; 388 u64 time; 389 } rcvq_space; 390 391 /* TCP-specific MTU probe information. */ 392 struct { 393 u32 probe_seq_start; 394 u32 probe_seq_end; 395 } mtu_probe; 396 u32 mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG 397 * while socket was owned by user. 398 */ 399 #if IS_ENABLED(CONFIG_MPTCP) 400 bool is_mptcp; 401 #endif 402 #if IS_ENABLED(CONFIG_SMC) 403 bool syn_smc; /* SYN includes SMC */ 404 #endif 405 406 #ifdef CONFIG_TCP_MD5SIG 407 /* TCP AF-Specific parts; only used by MD5 Signature support so far */ 408 const struct tcp_sock_af_ops *af_specific; 409 410 /* TCP MD5 Signature Option information */ 411 struct tcp_md5sig_info __rcu *md5sig_info; 412 #endif 413 414 /* TCP fastopen related information */ 415 struct tcp_fastopen_request *fastopen_req; 416 /* fastopen_rsk points to request_sock that resulted in this big 417 * socket. Used to retransmit SYNACKs etc. 418 */ 419 struct request_sock __rcu *fastopen_rsk; 420 struct saved_syn *saved_syn; 421 422 ANDROID_KABI_RESERVE(1); 423 }; 424 425 enum tsq_enum { 426 TSQ_THROTTLED, 427 TSQ_QUEUED, 428 TCP_TSQ_DEFERRED, /* tcp_tasklet_func() found socket was owned */ 429 TCP_WRITE_TIMER_DEFERRED, /* tcp_write_timer() found socket was owned */ 430 TCP_DELACK_TIMER_DEFERRED, /* tcp_delack_timer() found socket was owned */ 431 TCP_MTU_REDUCED_DEFERRED, /* tcp_v{4|6}_err() could not call 432 * tcp_v{4|6}_mtu_reduced() 433 */ 434 }; 435 436 enum tsq_flags { 437 TSQF_THROTTLED = (1UL << TSQ_THROTTLED), 438 TSQF_QUEUED = (1UL << TSQ_QUEUED), 439 TCPF_TSQ_DEFERRED = (1UL << TCP_TSQ_DEFERRED), 440 TCPF_WRITE_TIMER_DEFERRED = (1UL << TCP_WRITE_TIMER_DEFERRED), 441 TCPF_DELACK_TIMER_DEFERRED = (1UL << TCP_DELACK_TIMER_DEFERRED), 442 TCPF_MTU_REDUCED_DEFERRED = (1UL << TCP_MTU_REDUCED_DEFERRED), 443 }; 444 tcp_sk(const struct sock * sk)445 static inline struct tcp_sock *tcp_sk(const struct sock *sk) 446 { 447 return (struct tcp_sock *)sk; 448 } 449 450 struct tcp_timewait_sock { 451 struct inet_timewait_sock tw_sk; 452 #define tw_rcv_nxt tw_sk.__tw_common.skc_tw_rcv_nxt 453 #define tw_snd_nxt tw_sk.__tw_common.skc_tw_snd_nxt 454 u32 tw_rcv_wnd; 455 u32 tw_ts_offset; 456 u32 tw_ts_recent; 457 458 /* The time we sent the last out-of-window ACK: */ 459 u32 tw_last_oow_ack_time; 460 461 int tw_ts_recent_stamp; 462 u32 tw_tx_delay; 463 #ifdef CONFIG_TCP_MD5SIG 464 struct tcp_md5sig_key *tw_md5_key; 465 #endif 466 }; 467 tcp_twsk(const struct sock * sk)468 static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk) 469 { 470 return (struct tcp_timewait_sock *)sk; 471 } 472 tcp_passive_fastopen(const struct sock * sk)473 static inline bool tcp_passive_fastopen(const struct sock *sk) 474 { 475 return sk->sk_state == TCP_SYN_RECV && 476 rcu_access_pointer(tcp_sk(sk)->fastopen_rsk) != NULL; 477 } 478 fastopen_queue_tune(struct sock * sk,int backlog)479 static inline void fastopen_queue_tune(struct sock *sk, int backlog) 480 { 481 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; 482 int somaxconn = READ_ONCE(sock_net(sk)->core.sysctl_somaxconn); 483 484 WRITE_ONCE(queue->fastopenq.max_qlen, min_t(unsigned int, backlog, somaxconn)); 485 } 486 tcp_move_syn(struct tcp_sock * tp,struct request_sock * req)487 static inline void tcp_move_syn(struct tcp_sock *tp, 488 struct request_sock *req) 489 { 490 tp->saved_syn = req->saved_syn; 491 req->saved_syn = NULL; 492 } 493 tcp_saved_syn_free(struct tcp_sock * tp)494 static inline void tcp_saved_syn_free(struct tcp_sock *tp) 495 { 496 kfree(tp->saved_syn); 497 tp->saved_syn = NULL; 498 } 499 tcp_saved_syn_len(const struct saved_syn * saved_syn)500 static inline u32 tcp_saved_syn_len(const struct saved_syn *saved_syn) 501 { 502 return saved_syn->mac_hdrlen + saved_syn->network_hdrlen + 503 saved_syn->tcp_hdrlen; 504 } 505 506 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, 507 const struct sk_buff *orig_skb, 508 const struct sk_buff *ack_skb); 509 tcp_mss_clamp(const struct tcp_sock * tp,u16 mss)510 static inline u16 tcp_mss_clamp(const struct tcp_sock *tp, u16 mss) 511 { 512 /* We use READ_ONCE() here because socket might not be locked. 513 * This happens for listeners. 514 */ 515 u16 user_mss = READ_ONCE(tp->rx_opt.user_mss); 516 517 return (user_mss && user_mss < mss) ? user_mss : mss; 518 } 519 520 int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, int pcount, 521 int shiftlen); 522 523 void tcp_sock_set_cork(struct sock *sk, bool on); 524 int tcp_sock_set_keepcnt(struct sock *sk, int val); 525 int tcp_sock_set_keepidle_locked(struct sock *sk, int val); 526 int tcp_sock_set_keepidle(struct sock *sk, int val); 527 int tcp_sock_set_keepintvl(struct sock *sk, int val); 528 void tcp_sock_set_nodelay(struct sock *sk); 529 void tcp_sock_set_quickack(struct sock *sk, int val); 530 int tcp_sock_set_syncnt(struct sock *sk, int val); 531 void tcp_sock_set_user_timeout(struct sock *sk, u32 val); 532 533 #endif /* _LINUX_TCP_H */ 534