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