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 24 static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb) 25 { 26 return (struct tcphdr *)skb_transport_header(skb); 27 } 28 29 static inline unsigned int __tcp_hdrlen(const struct tcphdr *th) 30 { 31 return th->doff * 4; 32 } 33 34 static inline unsigned int tcp_hdrlen(const struct sk_buff *skb) 35 { 36 return __tcp_hdrlen(tcp_hdr(skb)); 37 } 38 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 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 */ 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 */ 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 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 accecn:6, /* AccECN index in header, 0=no options */ 126 saw_unknown:1, /* Received unknown option */ 127 unused:1; 128 u8 num_sacks; /* Number of SACK blocks */ 129 u16 user_mss; /* mss requested by user in ioctl */ 130 u16 mss_clamp; /* Maximal mss, negotiated at connection setup */ 131 }; 132 133 static inline void tcp_clear_options(struct tcp_options_received *rx_opt) 134 { 135 rx_opt->tstamp_ok = rx_opt->sack_ok = 0; 136 rx_opt->wscale_ok = rx_opt->snd_wscale = 0; 137 #if IS_ENABLED(CONFIG_SMC) 138 rx_opt->smc_ok = 0; 139 #endif 140 } 141 142 /* This is the max number of SACKS that we'll generate and process. It's safe 143 * to increase this, although since: 144 * size = TCPOLEN_SACK_BASE_ALIGNED (4) + n * TCPOLEN_SACK_PERBLOCK (8) 145 * only four options will fit in a standard TCP header */ 146 #define TCP_NUM_SACKS 4 147 148 struct tcp_request_sock_ops; 149 150 struct tcp_request_sock { 151 struct inet_request_sock req; 152 const struct tcp_request_sock_ops *af_specific; 153 u64 snt_synack; /* first SYNACK sent time */ 154 bool tfo_listener; 155 bool is_mptcp; 156 bool req_usec_ts; 157 #if IS_ENABLED(CONFIG_MPTCP) 158 bool drop_req; 159 #endif 160 u32 txhash; 161 u32 rcv_isn; 162 u32 snt_isn; 163 u32 ts_off; 164 u32 snt_tsval_first; 165 u32 snt_tsval_last; 166 u32 last_oow_ack_time; /* last SYNACK */ 167 u32 rcv_nxt; /* the ack # by SYNACK. For 168 * FastOpen it's the seq# 169 * after data-in-SYN. 170 */ 171 u8 syn_tos; 172 bool accecn_ok; 173 u8 syn_ect_snt: 2, 174 syn_ect_rcv: 2, 175 accecn_fail_mode:4; 176 u8 saw_accecn_opt :2; 177 #ifdef CONFIG_TCP_AO 178 u8 ao_keyid; 179 u8 ao_rcv_next; 180 bool used_tcp_ao; 181 #endif 182 }; 183 184 static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req) 185 { 186 return (struct tcp_request_sock *)req; 187 } 188 189 static inline bool tcp_rsk_used_ao(const struct request_sock *req) 190 { 191 #ifndef CONFIG_TCP_AO 192 return false; 193 #else 194 return tcp_rsk(req)->used_tcp_ao; 195 #endif 196 } 197 198 #define TCP_RMEM_TO_WIN_SCALE 8 199 200 struct tcp_sock { 201 /* Cacheline organization can be found documented in 202 * Documentation/networking/net_cachelines/tcp_sock.rst. 203 * Please update the document when adding new fields. 204 */ 205 206 /* inet_connection_sock has to be the first member of tcp_sock */ 207 struct inet_connection_sock inet_conn; 208 209 /* TX read-mostly hotpath cache lines */ 210 __cacheline_group_begin(tcp_sock_read_tx); 211 u32 max_window; /* Maximal window ever seen from peer */ 212 u32 rcv_ssthresh; /* Current window clamp */ 213 u32 reordering; /* Packet reordering metric. */ 214 u32 notsent_lowat; /* TCP_NOTSENT_LOWAT */ 215 u16 gso_segs; /* Max number of segs per GSO packet */ 216 /* from STCP, retrans queue hinting */ 217 struct sk_buff *retransmit_skb_hint; 218 #if defined(CONFIG_TLS_DEVICE) 219 void (*tcp_clean_acked)(struct sock *sk, u32 acked_seq); 220 #endif 221 __cacheline_group_end(tcp_sock_read_tx); 222 223 /* TXRX read-mostly hotpath cache lines */ 224 __cacheline_group_begin(tcp_sock_read_txrx); 225 u32 tsoffset; /* timestamp offset */ 226 u32 snd_wnd; /* The window we expect to receive */ 227 u32 mss_cache; /* Cached effective mss, not including SACKS */ 228 u32 snd_cwnd; /* Sending congestion window */ 229 u32 prr_out; /* Total number of pkts sent during Recovery. */ 230 u32 lost_out; /* Lost packets */ 231 u32 sacked_out; /* SACK'd packets */ 232 u16 tcp_header_len; /* Bytes of tcp header to send */ 233 u8 scaling_ratio; /* see tcp_win_from_space() */ 234 u8 chrono_type : 2, /* current chronograph type */ 235 repair : 1, 236 tcp_usec_ts : 1, /* TSval values in usec */ 237 is_sack_reneg:1, /* in recovery from loss with SACK reneg? */ 238 is_cwnd_limited:1,/* forward progress limited by snd_cwnd? */ 239 recvmsg_inq : 1;/* Indicate # of bytes in queue upon recvmsg */ 240 __cacheline_group_end(tcp_sock_read_txrx); 241 242 /* RX read-mostly hotpath cache lines */ 243 __cacheline_group_begin(tcp_sock_read_rx); 244 u32 copied_seq; /* Head of yet unread data */ 245 u32 snd_wl1; /* Sequence for window update */ 246 u32 tlp_high_seq; /* snd_nxt at the time of TLP */ 247 u32 rttvar_us; /* smoothed mdev_max */ 248 u32 retrans_out; /* Retransmitted packets out */ 249 u16 advmss; /* Advertised MSS */ 250 u16 urg_data; /* Saved octet of OOB data and control flags */ 251 u32 lost; /* Total data packets lost incl. rexmits */ 252 u32 snd_ssthresh; /* Slow start size threshold */ 253 struct minmax rtt_min; 254 /* OOO segments go in this rbtree. Socket lock must be held. */ 255 struct rb_root out_of_order_queue; 256 __cacheline_group_end(tcp_sock_read_rx); 257 258 /* TX read-write hotpath cache lines */ 259 __cacheline_group_begin(tcp_sock_write_tx) ____cacheline_aligned; 260 u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut 261 * The total number of segments sent. 262 */ 263 u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut 264 * total number of data segments sent. 265 */ 266 u64 bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut 267 * total number of data bytes sent. 268 */ 269 u32 snd_sml; /* Last byte of the most recently transmitted small packet */ 270 u32 chrono_start; /* Start time in jiffies of a TCP chrono */ 271 u32 chrono_stat[3]; /* Time in jiffies for chrono_stat stats */ 272 u32 write_seq; /* Tail(+1) of data held in tcp send buffer */ 273 u32 pushed_seq; /* Last pushed seq, required to talk to windows */ 274 u32 lsndtime; /* timestamp of last sent data packet (for restart window) */ 275 u32 mdev_us; /* medium deviation */ 276 u32 rtt_seq; /* sequence number to update rttvar */ 277 u64 tcp_wstamp_ns; /* departure time for next sent data packet */ 278 u64 accecn_opt_tstamp; /* Last AccECN option sent timestamp */ 279 struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */ 280 struct sk_buff *highest_sack; /* skb just after the highest 281 * skb with SACKed bit set 282 * (validity guaranteed only if 283 * sacked_out > 0) 284 */ 285 u8 ecn_flags; /* ECN status bits. */ 286 __cacheline_group_end(tcp_sock_write_tx); 287 288 /* TXRX read-write hotpath cache lines */ 289 __cacheline_group_begin(tcp_sock_write_txrx); 290 /* 291 * Header prediction flags 292 * 0x5?10 << 16 + snd_wnd in net byte order 293 */ 294 u8 nonagle : 4,/* Disable Nagle algorithm? */ 295 rate_app_limited:1; /* rate_{delivered,interval_us} limited? */ 296 u8 received_ce_pending:4, /* Not yet transmit cnt of received_ce */ 297 unused2:4; 298 u8 accecn_minlen:2,/* Minimum length of AccECN option sent */ 299 est_ecnfield:2,/* ECN field for AccECN delivered estimates */ 300 accecn_opt_demand:2,/* Demand AccECN option for n next ACKs */ 301 prev_ecnfield:2; /* ECN bits from the previous segment */ 302 __be32 pred_flags; 303 u64 tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */ 304 u64 tcp_mstamp; /* most recent packet received/sent */ 305 u32 rcv_nxt; /* What we want to receive next */ 306 u32 snd_nxt; /* Next sequence we send */ 307 u32 snd_una; /* First byte we want an ack for */ 308 u32 window_clamp; /* Maximal window to advertise */ 309 u32 srtt_us; /* smoothed round trip time << 3 in usecs */ 310 u32 packets_out; /* Packets which are "in flight" */ 311 u32 snd_up; /* Urgent pointer */ 312 u32 delivered; /* Total data packets delivered incl. rexmits */ 313 u32 delivered_ce; /* Like the above but only ECE marked packets */ 314 u32 received_ce; /* Like the above but for rcvd CE marked pkts */ 315 u32 received_ecn_bytes[3]; /* received byte counters for three ECN 316 * types: INET_ECN_ECT_1, INET_ECN_ECT_0, 317 * and INET_ECN_CE 318 */ 319 u32 app_limited; /* limited until "delivered" reaches this val */ 320 u32 rcv_wnd; /* Current receiver window */ 321 u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */ 322 /* 323 * Options received (usually on last packet, some only on SYN packets). 324 */ 325 struct tcp_options_received rx_opt; 326 __cacheline_group_end(tcp_sock_write_txrx); 327 328 /* RX read-write hotpath cache lines */ 329 __cacheline_group_begin(tcp_sock_write_rx) __aligned(8); 330 u64 bytes_received; 331 /* RFC4898 tcpEStatsAppHCThruOctetsReceived 332 * sum(delta(rcv_nxt)), or how many bytes 333 * were acked. 334 */ 335 u32 segs_in; /* RFC4898 tcpEStatsPerfSegsIn 336 * total number of segments in. 337 */ 338 u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn 339 * total number of data segments in. 340 */ 341 u32 rcv_wup; /* rcv_nxt on last window update sent */ 342 u32 max_packets_out; /* max packets_out in last window */ 343 u32 cwnd_usage_seq; /* right edge of cwnd usage tracking flight */ 344 u32 rate_delivered; /* saved rate sample: packets delivered */ 345 u32 rate_interval_us; /* saved rate sample: time elapsed */ 346 u32 rcv_rtt_last_tsecr; 347 u32 delivered_ecn_bytes[3]; 348 u64 first_tx_mstamp; /* start of window send phase */ 349 u64 delivered_mstamp; /* time we reached "delivered" */ 350 u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked 351 * sum(delta(snd_una)), or how many bytes 352 * were acked. 353 */ 354 struct { 355 u32 rtt_us; 356 u32 seq; 357 u64 time; 358 } rcv_rtt_est; 359 /* Receiver queue space */ 360 struct { 361 int space; 362 u32 seq; 363 u64 time; 364 } rcvq_space; 365 __cacheline_group_end(tcp_sock_write_rx); 366 /* End of Hot Path */ 367 368 /* 369 * RFC793 variables by their proper names. This means you can 370 * read the code and the spec side by side (and laugh ...) 371 * See RFC793 and RFC1122. The RFC writes these in capitals. 372 */ 373 u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups 374 * total number of DSACK blocks received 375 */ 376 u32 compressed_ack_rcv_nxt; 377 struct list_head tsq_node; /* anchor in tsq_tasklet.head list */ 378 379 /* Information of the most recently (s)acked skb */ 380 struct tcp_rack { 381 u64 mstamp; /* (Re)sent time of the skb */ 382 u32 rtt_us; /* Associated RTT */ 383 u32 end_seq; /* Ending TCP sequence of the skb */ 384 u32 last_delivered; /* tp->delivered at last reo_wnd adj */ 385 u8 reo_wnd_steps; /* Allowed reordering window */ 386 #define TCP_RACK_RECOVERY_THRESH 16 387 u8 reo_wnd_persist:5, /* No. of recovery since last adj */ 388 dsack_seen:1, /* Whether DSACK seen after last adj */ 389 advanced:1; /* mstamp advanced since last lost marking */ 390 } rack; 391 u8 compressed_ack; 392 u8 dup_ack_counter:2, 393 tlp_retrans:1, /* TLP is a retransmission */ 394 syn_ect_snt:2, /* AccECN ECT memory, only */ 395 syn_ect_rcv:2; /* ... needed during 3WHS + first seqno */ 396 u8 thin_lto : 1,/* Use linear timeouts for thin streams */ 397 fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */ 398 fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */ 399 fastopen_client_fail:2, /* reason why fastopen failed */ 400 frto : 1;/* F-RTO (RFC5682) activated in CA_Loss */ 401 u8 repair_queue; 402 u8 save_syn:2, /* Save headers of SYN packet */ 403 syn_data:1, /* SYN includes data */ 404 syn_fastopen:1, /* SYN includes Fast Open option */ 405 syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */ 406 syn_fastopen_ch:1, /* Active TFO re-enabling probe */ 407 syn_data_acked:1,/* data in SYN is acked by SYN-ACK */ 408 syn_fastopen_child:1; /* created TFO passive child socket */ 409 410 u8 keepalive_probes; /* num of allowed keep alive probes */ 411 u8 accecn_fail_mode:4, /* AccECN failure handling */ 412 saw_accecn_opt:2; /* An AccECN option was seen */ 413 u32 tcp_tx_delay; /* delay (in usec) added to TX packets */ 414 415 /* RTT measurement */ 416 u32 mdev_max_us; /* maximal mdev for the last rtt period */ 417 418 u32 reord_seen; /* number of data packet reordering events */ 419 420 /* 421 * Slow start and congestion control (see also Nagle, and Karn & Partridge) 422 */ 423 u32 snd_cwnd_cnt; /* Linear increase counter */ 424 u32 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */ 425 u32 snd_cwnd_used; 426 u32 snd_cwnd_stamp; 427 u32 prior_cwnd; /* cwnd right before starting loss recovery */ 428 u32 prr_delivered; /* Number of newly delivered packets to 429 * receiver in Recovery. */ 430 u32 last_oow_ack_time; /* timestamp of last out-of-window ACK */ 431 432 struct hrtimer pacing_timer; 433 struct hrtimer compressed_ack_timer; 434 435 struct sk_buff *ooo_last_skb; /* cache rb_last(out_of_order_queue) */ 436 437 /* SACKs data, these 2 need to be together (see tcp_options_write) */ 438 struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */ 439 struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/ 440 441 struct tcp_sack_block recv_sack_cache[4]; 442 443 u32 prior_ssthresh; /* ssthresh saved at recovery start */ 444 u32 high_seq; /* snd_nxt at onset of congestion */ 445 446 u32 retrans_stamp; /* Timestamp of the last retransmit, 447 * also used in SYN-SENT to remember stamp of 448 * the first SYN. */ 449 u32 undo_marker; /* snd_una upon a new recovery episode. */ 450 int undo_retrans; /* number of undoable retransmissions. */ 451 u32 mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG 452 * while socket was owned by user. 453 */ 454 u64 bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans 455 * Total data bytes retransmitted 456 */ 457 u32 total_retrans; /* Total retransmits for entire connection */ 458 u32 rto_stamp; /* Start time (ms) of last CA_Loss recovery */ 459 u16 total_rto; /* Total number of RTO timeouts, including 460 * SYN/SYN-ACK and recurring timeouts. 461 */ 462 u16 total_rto_recoveries; /* Total number of RTO recoveries, 463 * including any unfinished recovery. 464 */ 465 u32 total_rto_time; /* ms spent in (completed) RTO recoveries. */ 466 467 u32 urg_seq; /* Seq of received urgent pointer */ 468 unsigned int keepalive_time; /* time before keep alive takes place */ 469 unsigned int keepalive_intvl; /* time interval between keep alive probes */ 470 471 int linger2; 472 473 474 /* Sock_ops bpf program related variables */ 475 #ifdef CONFIG_BPF 476 u8 bpf_sock_ops_cb_flags; /* Control calling BPF programs 477 * values defined in uapi/linux/tcp.h 478 */ 479 u8 bpf_chg_cc_inprogress:1; /* In the middle of 480 * bpf_setsockopt(TCP_CONGESTION), 481 * it is to avoid the bpf_tcp_cc->init() 482 * to recur itself by calling 483 * bpf_setsockopt(TCP_CONGESTION, "itself"). 484 */ 485 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) (TP->bpf_sock_ops_cb_flags & ARG) 486 #else 487 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) 0 488 #endif 489 490 u16 timeout_rehash; /* Timeout-triggered rehash attempts */ 491 492 u32 rcv_ooopack; /* Received out-of-order packets, for tcpinfo */ 493 494 /* TCP-specific MTU probe information. */ 495 struct { 496 u32 probe_seq_start; 497 u32 probe_seq_end; 498 } mtu_probe; 499 u32 plb_rehash; /* PLB-triggered rehash attempts */ 500 #if IS_ENABLED(CONFIG_MPTCP) 501 bool is_mptcp; 502 #endif 503 #if IS_ENABLED(CONFIG_SMC) 504 bool syn_smc; /* SYN includes SMC */ 505 bool (*smc_hs_congested)(const struct sock *sk); 506 #endif 507 508 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) 509 /* TCP AF-Specific parts; only used by TCP-AO/MD5 Signature support so far */ 510 const struct tcp_sock_af_ops *af_specific; 511 512 #ifdef CONFIG_TCP_MD5SIG 513 /* TCP MD5 Signature Option information */ 514 struct tcp_md5sig_info __rcu *md5sig_info; 515 #endif 516 #ifdef CONFIG_TCP_AO 517 struct tcp_ao_info __rcu *ao_info; 518 #endif 519 #endif 520 521 /* TCP fastopen related information */ 522 struct tcp_fastopen_request *fastopen_req; 523 /* fastopen_rsk points to request_sock that resulted in this big 524 * socket. Used to retransmit SYNACKs etc. 525 */ 526 struct request_sock __rcu *fastopen_rsk; 527 struct saved_syn *saved_syn; 528 }; 529 530 enum tsq_enum { 531 TSQ_THROTTLED, 532 TSQ_QUEUED, 533 TCP_TSQ_DEFERRED, /* tcp_tasklet_func() found socket was owned */ 534 TCP_WRITE_TIMER_DEFERRED, /* tcp_write_timer() found socket was owned */ 535 TCP_DELACK_TIMER_DEFERRED, /* tcp_delack_timer() found socket was owned */ 536 TCP_MTU_REDUCED_DEFERRED, /* tcp_v{4|6}_err() could not call 537 * tcp_v{4|6}_mtu_reduced() 538 */ 539 TCP_ACK_DEFERRED, /* TX pure ack is deferred */ 540 }; 541 542 enum tsq_flags { 543 TSQF_THROTTLED = BIT(TSQ_THROTTLED), 544 TSQF_QUEUED = BIT(TSQ_QUEUED), 545 TCPF_TSQ_DEFERRED = BIT(TCP_TSQ_DEFERRED), 546 TCPF_WRITE_TIMER_DEFERRED = BIT(TCP_WRITE_TIMER_DEFERRED), 547 TCPF_DELACK_TIMER_DEFERRED = BIT(TCP_DELACK_TIMER_DEFERRED), 548 TCPF_MTU_REDUCED_DEFERRED = BIT(TCP_MTU_REDUCED_DEFERRED), 549 TCPF_ACK_DEFERRED = BIT(TCP_ACK_DEFERRED), 550 }; 551 552 #define tcp_sk(ptr) container_of_const(ptr, struct tcp_sock, inet_conn.icsk_inet.sk) 553 554 /* Variant of tcp_sk() upgrading a const sock to a read/write tcp socket. 555 * Used in context of (lockless) tcp listeners. 556 */ 557 #define tcp_sk_rw(ptr) container_of(ptr, struct tcp_sock, inet_conn.icsk_inet.sk) 558 559 struct tcp_timewait_sock { 560 struct inet_timewait_sock tw_sk; 561 #define tw_rcv_nxt tw_sk.__tw_common.skc_tw_rcv_nxt 562 #define tw_snd_nxt tw_sk.__tw_common.skc_tw_snd_nxt 563 u32 tw_rcv_wnd; 564 u32 tw_ts_offset; 565 u32 tw_ts_recent; 566 567 /* The time we sent the last out-of-window ACK: */ 568 u32 tw_last_oow_ack_time; 569 570 int tw_ts_recent_stamp; 571 u32 tw_tx_delay; 572 #ifdef CONFIG_TCP_MD5SIG 573 struct tcp_md5sig_key *tw_md5_key; 574 #endif 575 #ifdef CONFIG_TCP_AO 576 struct tcp_ao_info __rcu *ao_info; 577 #endif 578 }; 579 580 static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk) 581 { 582 return (struct tcp_timewait_sock *)sk; 583 } 584 585 static inline bool tcp_passive_fastopen(const struct sock *sk) 586 { 587 return sk->sk_state == TCP_SYN_RECV && 588 rcu_access_pointer(tcp_sk(sk)->fastopen_rsk) != NULL; 589 } 590 591 static inline void fastopen_queue_tune(struct sock *sk, int backlog) 592 { 593 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; 594 int somaxconn = READ_ONCE(sock_net(sk)->core.sysctl_somaxconn); 595 596 WRITE_ONCE(queue->fastopenq.max_qlen, min_t(unsigned int, backlog, somaxconn)); 597 } 598 599 static inline void tcp_move_syn(struct tcp_sock *tp, 600 struct request_sock *req) 601 { 602 tp->saved_syn = req->saved_syn; 603 req->saved_syn = NULL; 604 } 605 606 static inline void tcp_saved_syn_free(struct tcp_sock *tp) 607 { 608 kfree(tp->saved_syn); 609 tp->saved_syn = NULL; 610 } 611 612 static inline u32 tcp_saved_syn_len(const struct saved_syn *saved_syn) 613 { 614 return saved_syn->mac_hdrlen + saved_syn->network_hdrlen + 615 saved_syn->tcp_hdrlen; 616 } 617 618 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, 619 const struct sk_buff *orig_skb, 620 const struct sk_buff *ack_skb); 621 622 static inline u16 tcp_mss_clamp(const struct tcp_sock *tp, u16 mss) 623 { 624 /* We use READ_ONCE() here because socket might not be locked. 625 * This happens for listeners. 626 */ 627 u16 user_mss = READ_ONCE(tp->rx_opt.user_mss); 628 629 return (user_mss && user_mss < mss) ? user_mss : mss; 630 } 631 632 int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, int pcount, 633 int shiftlen); 634 635 void __tcp_sock_set_cork(struct sock *sk, bool on); 636 void tcp_sock_set_cork(struct sock *sk, bool on); 637 int tcp_sock_set_keepcnt(struct sock *sk, int val); 638 int tcp_sock_set_keepidle_locked(struct sock *sk, int val); 639 int tcp_sock_set_keepidle(struct sock *sk, int val); 640 int tcp_sock_set_keepintvl(struct sock *sk, int val); 641 void __tcp_sock_set_nodelay(struct sock *sk, bool on); 642 void tcp_sock_set_nodelay(struct sock *sk); 643 void tcp_sock_set_quickack(struct sock *sk, int val); 644 int tcp_sock_set_syncnt(struct sock *sk, int val); 645 int tcp_sock_set_user_timeout(struct sock *sk, int val); 646 int tcp_sock_set_maxseg(struct sock *sk, int val); 647 648 static inline bool dst_tcp_usec_ts(const struct dst_entry *dst) 649 { 650 return dst_feature(dst, RTAX_FEATURE_TCP_USEC_TS); 651 } 652 653 #endif /* _LINUX_TCP_H */ 654