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 <net/sock.h> 20 #include <net/inet_connection_sock.h> 21 #include <net/inet_timewait_sock.h> 22 #include <uapi/linux/tcp.h> 23 tcp_hdr(const struct sk_buff * skb)24 static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb) 25 { 26 return (struct tcphdr *)skb_transport_header(skb); 27 } 28 __tcp_hdrlen(const struct tcphdr * th)29 static inline unsigned int __tcp_hdrlen(const struct tcphdr *th) 30 { 31 return th->doff * 4; 32 } 33 tcp_hdrlen(const struct sk_buff * skb)34 static inline unsigned int tcp_hdrlen(const struct sk_buff *skb) 35 { 36 return __tcp_hdrlen(tcp_hdr(skb)); 37 } 38 inner_tcp_hdr(const struct sk_buff * skb)39 static inline struct tcphdr *inner_tcp_hdr(const struct sk_buff *skb) 40 { 41 return (struct tcphdr *)skb_inner_transport_header(skb); 42 } 43 inner_tcp_hdrlen(const struct sk_buff * skb)44 static inline unsigned int inner_tcp_hdrlen(const struct sk_buff *skb) 45 { 46 return inner_tcp_hdr(skb)->doff * 4; 47 } 48 49 /** 50 * skb_tcp_all_headers - Returns size of all headers for a TCP packet 51 * @skb: buffer 52 * 53 * Used in TX path, for a packet known to be a TCP one. 54 * 55 * if (skb_is_gso(skb)) { 56 * int hlen = skb_tcp_all_headers(skb); 57 * ... 58 */ skb_tcp_all_headers(const struct sk_buff * skb)59 static inline int skb_tcp_all_headers(const struct sk_buff *skb) 60 { 61 return skb_transport_offset(skb) + tcp_hdrlen(skb); 62 } 63 64 /** 65 * skb_inner_tcp_all_headers - Returns size of all headers for an encap TCP packet 66 * @skb: buffer 67 * 68 * Used in TX path, for a packet known to be a TCP one. 69 * 70 * if (skb_is_gso(skb) && skb->encapsulation) { 71 * int hlen = skb_inner_tcp_all_headers(skb); 72 * ... 73 */ skb_inner_tcp_all_headers(const struct sk_buff * skb)74 static inline int skb_inner_tcp_all_headers(const struct sk_buff *skb) 75 { 76 return skb_inner_transport_offset(skb) + inner_tcp_hdrlen(skb); 77 } 78 tcp_optlen(const struct sk_buff * skb)79 static inline unsigned int tcp_optlen(const struct sk_buff *skb) 80 { 81 return (tcp_hdr(skb)->doff - 5) * 4; 82 } 83 84 /* TCP Fast Open */ 85 #define TCP_FASTOPEN_COOKIE_MIN 4 /* Min Fast Open Cookie size in bytes */ 86 #define TCP_FASTOPEN_COOKIE_MAX 16 /* Max Fast Open Cookie size in bytes */ 87 #define TCP_FASTOPEN_COOKIE_SIZE 8 /* the size employed by this impl. */ 88 89 /* TCP Fast Open Cookie as stored in memory */ 90 struct tcp_fastopen_cookie { 91 __le64 val[DIV_ROUND_UP(TCP_FASTOPEN_COOKIE_MAX, sizeof(u64))]; 92 s8 len; 93 bool exp; /* In RFC6994 experimental option format */ 94 }; 95 96 /* This defines a selective acknowledgement block. */ 97 struct tcp_sack_block_wire { 98 __be32 start_seq; 99 __be32 end_seq; 100 }; 101 102 struct tcp_sack_block { 103 u32 start_seq; 104 u32 end_seq; 105 }; 106 107 /*These are used to set the sack_ok field in struct tcp_options_received */ 108 #define TCP_SACK_SEEN (1 << 0) /*1 = peer is SACK capable, */ 109 #define TCP_DSACK_SEEN (1 << 2) /*1 = DSACK was received from peer*/ 110 111 struct tcp_options_received { 112 /* PAWS/RTTM data */ 113 int ts_recent_stamp;/* Time we stored ts_recent (for aging) */ 114 u32 ts_recent; /* Time stamp to echo next */ 115 u32 rcv_tsval; /* Time stamp value */ 116 u32 rcv_tsecr; /* Time stamp echo reply */ 117 u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */ 118 tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */ 119 dsack : 1, /* D-SACK is scheduled */ 120 wscale_ok : 1, /* Wscale seen on SYN packet */ 121 sack_ok : 3, /* SACK seen on SYN packet */ 122 smc_ok : 1, /* SMC seen on SYN packet */ 123 snd_wscale : 4, /* Window scaling received from sender */ 124 rcv_wscale : 4; /* Window scaling to send to receiver */ 125 u8 saw_unknown:1, /* Received unknown option */ 126 unused:7; 127 u8 num_sacks; /* Number of SACK blocks */ 128 u16 user_mss; /* mss requested by user in ioctl */ 129 u16 mss_clamp; /* Maximal mss, negotiated at connection setup */ 130 }; 131 tcp_clear_options(struct tcp_options_received * rx_opt)132 static inline void tcp_clear_options(struct tcp_options_received *rx_opt) 133 { 134 rx_opt->tstamp_ok = rx_opt->sack_ok = 0; 135 rx_opt->wscale_ok = rx_opt->snd_wscale = 0; 136 #if IS_ENABLED(CONFIG_SMC) 137 rx_opt->smc_ok = 0; 138 #endif 139 } 140 141 /* This is the max number of SACKS that we'll generate and process. It's safe 142 * to increase this, although since: 143 * size = TCPOLEN_SACK_BASE_ALIGNED (4) + n * TCPOLEN_SACK_PERBLOCK (8) 144 * only four options will fit in a standard TCP header */ 145 #define TCP_NUM_SACKS 4 146 147 struct tcp_request_sock_ops; 148 149 struct tcp_request_sock { 150 struct inet_request_sock req; 151 const struct tcp_request_sock_ops *af_specific; 152 u64 snt_synack; /* first SYNACK sent time */ 153 bool tfo_listener; 154 bool is_mptcp; 155 bool req_usec_ts; 156 #if IS_ENABLED(CONFIG_MPTCP) 157 bool drop_req; 158 #endif 159 u32 txhash; 160 u32 rcv_isn; 161 u32 snt_isn; 162 u32 ts_off; 163 u32 last_oow_ack_time; /* last SYNACK */ 164 u32 rcv_nxt; /* the ack # by SYNACK. For 165 * FastOpen it's the seq# 166 * after data-in-SYN. 167 */ 168 u8 syn_tos; 169 #ifdef CONFIG_TCP_AO 170 u8 ao_keyid; 171 u8 ao_rcv_next; 172 bool used_tcp_ao; 173 #endif 174 }; 175 tcp_rsk(const struct request_sock * req)176 static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req) 177 { 178 return (struct tcp_request_sock *)req; 179 } 180 tcp_rsk_used_ao(const struct request_sock * req)181 static inline bool tcp_rsk_used_ao(const struct request_sock *req) 182 { 183 #ifndef CONFIG_TCP_AO 184 return false; 185 #else 186 return tcp_rsk(req)->used_tcp_ao; 187 #endif 188 } 189 190 #define TCP_RMEM_TO_WIN_SCALE 8 191 192 struct tcp_sock { 193 /* Cacheline organization can be found documented in 194 * Documentation/networking/net_cachelines/tcp_sock.rst. 195 * Please update the document when adding new fields. 196 */ 197 198 /* inet_connection_sock has to be the first member of tcp_sock */ 199 struct inet_connection_sock inet_conn; 200 201 /* TX read-mostly hotpath cache lines */ 202 __cacheline_group_begin(tcp_sock_read_tx); 203 /* timestamp of last sent data packet (for restart window) */ 204 u32 max_window; /* Maximal window ever seen from peer */ 205 u32 rcv_ssthresh; /* Current window clamp */ 206 u32 reordering; /* Packet reordering metric. */ 207 u32 notsent_lowat; /* TCP_NOTSENT_LOWAT */ 208 u16 gso_segs; /* Max number of segs per GSO packet */ 209 /* from STCP, retrans queue hinting */ 210 struct sk_buff *lost_skb_hint; 211 struct sk_buff *retransmit_skb_hint; 212 __cacheline_group_end(tcp_sock_read_tx); 213 214 /* TXRX read-mostly hotpath cache lines */ 215 __cacheline_group_begin(tcp_sock_read_txrx); 216 u32 tsoffset; /* timestamp offset */ 217 u32 snd_wnd; /* The window we expect to receive */ 218 u32 mss_cache; /* Cached effective mss, not including SACKS */ 219 u32 snd_cwnd; /* Sending congestion window */ 220 u32 prr_out; /* Total number of pkts sent during Recovery. */ 221 u32 lost_out; /* Lost packets */ 222 u32 sacked_out; /* SACK'd packets */ 223 u16 tcp_header_len; /* Bytes of tcp header to send */ 224 u8 scaling_ratio; /* see tcp_win_from_space() */ 225 u8 chrono_type : 2, /* current chronograph type */ 226 repair : 1, 227 tcp_usec_ts : 1, /* TSval values in usec */ 228 is_sack_reneg:1, /* in recovery from loss with SACK reneg? */ 229 is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */ 230 __cacheline_group_end(tcp_sock_read_txrx); 231 232 /* RX read-mostly hotpath cache lines */ 233 __cacheline_group_begin(tcp_sock_read_rx); 234 u32 copied_seq; /* Head of yet unread data */ 235 u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ 236 u32 snd_wl1; /* Sequence for window update */ 237 u32 tlp_high_seq; /* snd_nxt at the time of TLP */ 238 u32 rttvar_us; /* smoothed mdev_max */ 239 u32 retrans_out; /* Retransmitted packets out */ 240 u16 advmss; /* Advertised MSS */ 241 u16 urg_data; /* Saved octet of OOB data and control flags */ 242 u32 lost; /* Total data packets lost incl. rexmits */ 243 struct minmax rtt_min; 244 /* OOO segments go in this rbtree. Socket lock must be held. */ 245 struct rb_root out_of_order_queue; 246 u32 snd_ssthresh; /* Slow start size threshold */ 247 u8 recvmsg_inq : 1;/* Indicate # of bytes in queue upon recvmsg */ 248 __cacheline_group_end(tcp_sock_read_rx); 249 250 /* TX read-write hotpath cache lines */ 251 __cacheline_group_begin(tcp_sock_write_tx) ____cacheline_aligned; 252 u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut 253 * The total number of segments sent. 254 */ 255 u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut 256 * total number of data segments sent. 257 */ 258 u64 bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut 259 * total number of data bytes sent. 260 */ 261 u32 snd_sml; /* Last byte of the most recently transmitted small packet */ 262 u32 chrono_start; /* Start time in jiffies of a TCP chrono */ 263 u32 chrono_stat[3]; /* Time in jiffies for chrono_stat stats */ 264 u32 write_seq; /* Tail(+1) of data held in tcp send buffer */ 265 u32 pushed_seq; /* Last pushed seq, required to talk to windows */ 266 u32 lsndtime; 267 u32 mdev_us; /* medium deviation */ 268 u32 rtt_seq; /* sequence number to update rttvar */ 269 u64 tcp_wstamp_ns; /* departure time for next sent data packet */ 270 struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */ 271 struct sk_buff *highest_sack; /* skb just after the highest 272 * skb with SACKed bit set 273 * (validity guaranteed only if 274 * sacked_out > 0) 275 */ 276 u8 ecn_flags; /* ECN status bits. */ 277 __cacheline_group_end(tcp_sock_write_tx); 278 279 /* TXRX read-write hotpath cache lines */ 280 __cacheline_group_begin(tcp_sock_write_txrx); 281 /* 282 * Header prediction flags 283 * 0x5?10 << 16 + snd_wnd in net byte order 284 */ 285 __be32 pred_flags; 286 u64 tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */ 287 u64 tcp_mstamp; /* most recent packet received/sent */ 288 u32 rcv_nxt; /* What we want to receive next */ 289 u32 snd_nxt; /* Next sequence we send */ 290 u32 snd_una; /* First byte we want an ack for */ 291 u32 window_clamp; /* Maximal window to advertise */ 292 u32 srtt_us; /* smoothed round trip time << 3 in usecs */ 293 u32 packets_out; /* Packets which are "in flight" */ 294 u32 snd_up; /* Urgent pointer */ 295 u32 delivered; /* Total data packets delivered incl. rexmits */ 296 u32 delivered_ce; /* Like the above but only ECE marked packets */ 297 u32 app_limited; /* limited until "delivered" reaches this val */ 298 u32 rcv_wnd; /* Current receiver window */ 299 /* 300 * Options received (usually on last packet, some only on SYN packets). 301 */ 302 struct tcp_options_received rx_opt; 303 u8 nonagle : 4,/* Disable Nagle algorithm? */ 304 rate_app_limited:1; /* rate_{delivered,interval_us} limited? */ 305 __cacheline_group_end(tcp_sock_write_txrx); 306 307 /* RX read-write hotpath cache lines */ 308 __cacheline_group_begin(tcp_sock_write_rx) __aligned(8); 309 u64 bytes_received; 310 /* RFC4898 tcpEStatsAppHCThruOctetsReceived 311 * sum(delta(rcv_nxt)), or how many bytes 312 * were acked. 313 */ 314 u32 segs_in; /* RFC4898 tcpEStatsPerfSegsIn 315 * total number of segments in. 316 */ 317 u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn 318 * total number of data segments in. 319 */ 320 u32 rcv_wup; /* rcv_nxt on last window update sent */ 321 u32 max_packets_out; /* max packets_out in last window */ 322 u32 cwnd_usage_seq; /* right edge of cwnd usage tracking flight */ 323 u32 rate_delivered; /* saved rate sample: packets delivered */ 324 u32 rate_interval_us; /* saved rate sample: time elapsed */ 325 u32 rcv_rtt_last_tsecr; 326 u64 first_tx_mstamp; /* start of window send phase */ 327 u64 delivered_mstamp; /* time we reached "delivered" */ 328 u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked 329 * sum(delta(snd_una)), or how many bytes 330 * were acked. 331 */ 332 struct { 333 u32 rtt_us; 334 u32 seq; 335 u64 time; 336 } rcv_rtt_est; 337 /* Receiver queue space */ 338 struct { 339 u32 space; 340 u32 seq; 341 u64 time; 342 } rcvq_space; 343 __cacheline_group_end(tcp_sock_write_rx); 344 /* End of Hot Path */ 345 346 /* 347 * RFC793 variables by their proper names. This means you can 348 * read the code and the spec side by side (and laugh ...) 349 * See RFC793 and RFC1122. The RFC writes these in capitals. 350 */ 351 u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups 352 * total number of DSACK blocks received 353 */ 354 u32 compressed_ack_rcv_nxt; 355 struct list_head tsq_node; /* anchor in tsq_tasklet.head list */ 356 357 /* Information of the most recently (s)acked skb */ 358 struct tcp_rack { 359 u64 mstamp; /* (Re)sent time of the skb */ 360 u32 rtt_us; /* Associated RTT */ 361 u32 end_seq; /* Ending TCP sequence of the skb */ 362 u32 last_delivered; /* tp->delivered at last reo_wnd adj */ 363 u8 reo_wnd_steps; /* Allowed reordering window */ 364 #define TCP_RACK_RECOVERY_THRESH 16 365 u8 reo_wnd_persist:5, /* No. of recovery since last adj */ 366 dsack_seen:1, /* Whether DSACK seen after last adj */ 367 advanced:1; /* mstamp advanced since last lost marking */ 368 } rack; 369 u8 compressed_ack; 370 u8 dup_ack_counter:2, 371 tlp_retrans:1, /* TLP is a retransmission */ 372 unused:5; 373 u8 thin_lto : 1,/* Use linear timeouts for thin streams */ 374 fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */ 375 fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */ 376 fastopen_client_fail:2, /* reason why fastopen failed */ 377 frto : 1;/* F-RTO (RFC5682) activated in CA_Loss */ 378 u8 repair_queue; 379 u8 save_syn:2, /* Save headers of SYN packet */ 380 syn_data:1, /* SYN includes data */ 381 syn_fastopen:1, /* SYN includes Fast Open option */ 382 syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */ 383 syn_fastopen_ch:1, /* Active TFO re-enabling probe */ 384 syn_data_acked:1;/* data in SYN is acked by SYN-ACK */ 385 386 u8 keepalive_probes; /* num of allowed keep alive probes */ 387 u32 tcp_tx_delay; /* delay (in usec) added to TX packets */ 388 389 /* RTT measurement */ 390 u32 mdev_max_us; /* maximal mdev for the last rtt period */ 391 392 u32 reord_seen; /* number of data packet reordering events */ 393 394 /* 395 * Slow start and congestion control (see also Nagle, and Karn & Partridge) 396 */ 397 u32 snd_cwnd_cnt; /* Linear increase counter */ 398 u32 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */ 399 u32 snd_cwnd_used; 400 u32 snd_cwnd_stamp; 401 u32 prior_cwnd; /* cwnd right before starting loss recovery */ 402 u32 prr_delivered; /* Number of newly delivered packets to 403 * receiver in Recovery. */ 404 u32 last_oow_ack_time; /* timestamp of last out-of-window ACK */ 405 406 struct hrtimer pacing_timer; 407 struct hrtimer compressed_ack_timer; 408 409 struct sk_buff *ooo_last_skb; /* cache rb_last(out_of_order_queue) */ 410 411 /* SACKs data, these 2 need to be together (see tcp_options_write) */ 412 struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */ 413 struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/ 414 415 struct tcp_sack_block recv_sack_cache[4]; 416 417 int lost_cnt_hint; 418 419 u32 prior_ssthresh; /* ssthresh saved at recovery start */ 420 u32 high_seq; /* snd_nxt at onset of congestion */ 421 422 u32 retrans_stamp; /* Timestamp of the last retransmit, 423 * also used in SYN-SENT to remember stamp of 424 * the first SYN. */ 425 u32 undo_marker; /* snd_una upon a new recovery episode. */ 426 int undo_retrans; /* number of undoable retransmissions. */ 427 u64 bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans 428 * Total data bytes retransmitted 429 */ 430 u32 total_retrans; /* Total retransmits for entire connection */ 431 u32 rto_stamp; /* Start time (ms) of last CA_Loss recovery */ 432 u16 total_rto; /* Total number of RTO timeouts, including 433 * SYN/SYN-ACK and recurring timeouts. 434 */ 435 u16 total_rto_recoveries; /* Total number of RTO recoveries, 436 * including any unfinished recovery. 437 */ 438 u32 total_rto_time; /* ms spent in (completed) RTO recoveries. */ 439 440 u32 urg_seq; /* Seq of received urgent pointer */ 441 unsigned int keepalive_time; /* time before keep alive takes place */ 442 unsigned int keepalive_intvl; /* time interval between keep alive probes */ 443 444 int linger2; 445 446 447 /* Sock_ops bpf program related variables */ 448 #ifdef CONFIG_BPF 449 u8 bpf_sock_ops_cb_flags; /* Control calling BPF programs 450 * values defined in uapi/linux/tcp.h 451 */ 452 u8 bpf_chg_cc_inprogress:1; /* In the middle of 453 * bpf_setsockopt(TCP_CONGESTION), 454 * it is to avoid the bpf_tcp_cc->init() 455 * to recur itself by calling 456 * bpf_setsockopt(TCP_CONGESTION, "itself"). 457 */ 458 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) (TP->bpf_sock_ops_cb_flags & ARG) 459 #else 460 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) 0 461 #endif 462 463 u16 timeout_rehash; /* Timeout-triggered rehash attempts */ 464 465 u32 rcv_ooopack; /* Received out-of-order packets, for tcpinfo */ 466 467 /* TCP-specific MTU probe information. */ 468 struct { 469 u32 probe_seq_start; 470 u32 probe_seq_end; 471 } mtu_probe; 472 u32 plb_rehash; /* PLB-triggered rehash attempts */ 473 u32 mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG 474 * while socket was owned by user. 475 */ 476 #if IS_ENABLED(CONFIG_MPTCP) 477 bool is_mptcp; 478 #endif 479 #if IS_ENABLED(CONFIG_SMC) 480 bool syn_smc; /* SYN includes SMC */ 481 bool (*smc_hs_congested)(const struct sock *sk); 482 #endif 483 484 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 485 /* TCP AF-Specific parts; only used by TCP-AO/MD5 Signature support so far */ 486 const struct tcp_sock_af_ops *af_specific; 487 488 #ifdef CONFIG_TCP_MD5SIG 489 /* TCP MD5 Signature Option information */ 490 struct tcp_md5sig_info __rcu *md5sig_info; 491 #endif 492 #ifdef CONFIG_TCP_AO 493 struct tcp_ao_info __rcu *ao_info; 494 #endif 495 #endif 496 497 /* TCP fastopen related information */ 498 struct tcp_fastopen_request *fastopen_req; 499 /* fastopen_rsk points to request_sock that resulted in this big 500 * socket. Used to retransmit SYNACKs etc. 501 */ 502 struct request_sock __rcu *fastopen_rsk; 503 struct saved_syn *saved_syn; 504 }; 505 506 enum tsq_enum { 507 TSQ_THROTTLED, 508 TSQ_QUEUED, 509 TCP_TSQ_DEFERRED, /* tcp_tasklet_func() found socket was owned */ 510 TCP_WRITE_TIMER_DEFERRED, /* tcp_write_timer() found socket was owned */ 511 TCP_DELACK_TIMER_DEFERRED, /* tcp_delack_timer() found socket was owned */ 512 TCP_MTU_REDUCED_DEFERRED, /* tcp_v{4|6}_err() could not call 513 * tcp_v{4|6}_mtu_reduced() 514 */ 515 TCP_ACK_DEFERRED, /* TX pure ack is deferred */ 516 }; 517 518 enum tsq_flags { 519 TSQF_THROTTLED = BIT(TSQ_THROTTLED), 520 TSQF_QUEUED = BIT(TSQ_QUEUED), 521 TCPF_TSQ_DEFERRED = BIT(TCP_TSQ_DEFERRED), 522 TCPF_WRITE_TIMER_DEFERRED = BIT(TCP_WRITE_TIMER_DEFERRED), 523 TCPF_DELACK_TIMER_DEFERRED = BIT(TCP_DELACK_TIMER_DEFERRED), 524 TCPF_MTU_REDUCED_DEFERRED = BIT(TCP_MTU_REDUCED_DEFERRED), 525 TCPF_ACK_DEFERRED = BIT(TCP_ACK_DEFERRED), 526 }; 527 528 #define tcp_sk(ptr) container_of_const(ptr, struct tcp_sock, inet_conn.icsk_inet.sk) 529 530 /* Variant of tcp_sk() upgrading a const sock to a read/write tcp socket. 531 * Used in context of (lockless) tcp listeners. 532 */ 533 #define tcp_sk_rw(ptr) container_of(ptr, struct tcp_sock, inet_conn.icsk_inet.sk) 534 535 struct tcp_timewait_sock { 536 struct inet_timewait_sock tw_sk; 537 #define tw_rcv_nxt tw_sk.__tw_common.skc_tw_rcv_nxt 538 #define tw_snd_nxt tw_sk.__tw_common.skc_tw_snd_nxt 539 u32 tw_rcv_wnd; 540 u32 tw_ts_offset; 541 u32 tw_ts_recent; 542 543 /* The time we sent the last out-of-window ACK: */ 544 u32 tw_last_oow_ack_time; 545 546 int tw_ts_recent_stamp; 547 u32 tw_tx_delay; 548 #ifdef CONFIG_TCP_MD5SIG 549 struct tcp_md5sig_key *tw_md5_key; 550 #endif 551 #ifdef CONFIG_TCP_AO 552 struct tcp_ao_info __rcu *ao_info; 553 #endif 554 }; 555 tcp_twsk(const struct sock * sk)556 static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk) 557 { 558 return (struct tcp_timewait_sock *)sk; 559 } 560 tcp_passive_fastopen(const struct sock * sk)561 static inline bool tcp_passive_fastopen(const struct sock *sk) 562 { 563 return sk->sk_state == TCP_SYN_RECV && 564 rcu_access_pointer(tcp_sk(sk)->fastopen_rsk) != NULL; 565 } 566 fastopen_queue_tune(struct sock * sk,int backlog)567 static inline void fastopen_queue_tune(struct sock *sk, int backlog) 568 { 569 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; 570 int somaxconn = READ_ONCE(sock_net(sk)->core.sysctl_somaxconn); 571 572 WRITE_ONCE(queue->fastopenq.max_qlen, min_t(unsigned int, backlog, somaxconn)); 573 } 574 tcp_move_syn(struct tcp_sock * tp,struct request_sock * req)575 static inline void tcp_move_syn(struct tcp_sock *tp, 576 struct request_sock *req) 577 { 578 tp->saved_syn = req->saved_syn; 579 req->saved_syn = NULL; 580 } 581 tcp_saved_syn_free(struct tcp_sock * tp)582 static inline void tcp_saved_syn_free(struct tcp_sock *tp) 583 { 584 kfree(tp->saved_syn); 585 tp->saved_syn = NULL; 586 } 587 tcp_saved_syn_len(const struct saved_syn * saved_syn)588 static inline u32 tcp_saved_syn_len(const struct saved_syn *saved_syn) 589 { 590 return saved_syn->mac_hdrlen + saved_syn->network_hdrlen + 591 saved_syn->tcp_hdrlen; 592 } 593 594 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, 595 const struct sk_buff *orig_skb, 596 const struct sk_buff *ack_skb); 597 tcp_mss_clamp(const struct tcp_sock * tp,u16 mss)598 static inline u16 tcp_mss_clamp(const struct tcp_sock *tp, u16 mss) 599 { 600 /* We use READ_ONCE() here because socket might not be locked. 601 * This happens for listeners. 602 */ 603 u16 user_mss = READ_ONCE(tp->rx_opt.user_mss); 604 605 return (user_mss && user_mss < mss) ? user_mss : mss; 606 } 607 608 int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, int pcount, 609 int shiftlen); 610 611 void __tcp_sock_set_cork(struct sock *sk, bool on); 612 void tcp_sock_set_cork(struct sock *sk, bool on); 613 int tcp_sock_set_keepcnt(struct sock *sk, int val); 614 int tcp_sock_set_keepidle_locked(struct sock *sk, int val); 615 int tcp_sock_set_keepidle(struct sock *sk, int val); 616 int tcp_sock_set_keepintvl(struct sock *sk, int val); 617 void __tcp_sock_set_nodelay(struct sock *sk, bool on); 618 void tcp_sock_set_nodelay(struct sock *sk); 619 void tcp_sock_set_quickack(struct sock *sk, int val); 620 int tcp_sock_set_syncnt(struct sock *sk, int val); 621 int tcp_sock_set_user_timeout(struct sock *sk, int val); 622 dst_tcp_usec_ts(const struct dst_entry * dst)623 static inline bool dst_tcp_usec_ts(const struct dst_entry *dst) 624 { 625 return dst_feature(dst, RTAX_FEATURE_TCP_USEC_TS); 626 } 627 628 #endif /* _LINUX_TCP_H */ 629