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
50 /**
51 * skb_tcp_all_headers - Returns size of all headers for a TCP packet
52 * @skb: buffer
53 *
54 * Used in TX path, for a packet known to be a TCP one.
55 *
56 * if (skb_is_gso(skb)) {
57 * int hlen = skb_tcp_all_headers(skb);
58 * ...
59 */
skb_tcp_all_headers(const struct sk_buff * skb)60 static inline int skb_tcp_all_headers(const struct sk_buff *skb)
61 {
62 return skb_transport_offset(skb) + tcp_hdrlen(skb);
63 }
64
65 /**
66 * skb_inner_tcp_all_headers - Returns size of all headers for an encap TCP packet
67 * @skb: buffer
68 *
69 * Used in TX path, for a packet known to be a TCP one.
70 *
71 * if (skb_is_gso(skb) && skb->encapsulation) {
72 * int hlen = skb_inner_tcp_all_headers(skb);
73 * ...
74 */
skb_inner_tcp_all_headers(const struct sk_buff * skb)75 static inline int skb_inner_tcp_all_headers(const struct sk_buff *skb)
76 {
77 return skb_inner_transport_offset(skb) + inner_tcp_hdrlen(skb);
78 }
79
tcp_optlen(const struct sk_buff * skb)80 static inline unsigned int tcp_optlen(const struct sk_buff *skb)
81 {
82 return (tcp_hdr(skb)->doff - 5) * 4;
83 }
84
85 /* TCP Fast Open */
86 #define TCP_FASTOPEN_COOKIE_MIN 4 /* Min Fast Open Cookie size in bytes */
87 #define TCP_FASTOPEN_COOKIE_MAX 16 /* Max Fast Open Cookie size in bytes */
88 #define TCP_FASTOPEN_COOKIE_SIZE 8 /* the size employed by this impl. */
89
90 /* TCP Fast Open Cookie as stored in memory */
91 struct tcp_fastopen_cookie {
92 __le64 val[DIV_ROUND_UP(TCP_FASTOPEN_COOKIE_MAX, sizeof(u64))];
93 s8 len;
94 bool exp; /* In RFC6994 experimental option format */
95 };
96
97 /* This defines a selective acknowledgement block. */
98 struct tcp_sack_block_wire {
99 __be32 start_seq;
100 __be32 end_seq;
101 };
102
103 struct tcp_sack_block {
104 u32 start_seq;
105 u32 end_seq;
106 };
107
108 /*These are used to set the sack_ok field in struct tcp_options_received */
109 #define TCP_SACK_SEEN (1 << 0) /*1 = peer is SACK capable, */
110 #define TCP_DSACK_SEEN (1 << 2) /*1 = DSACK was received from peer*/
111
112 struct tcp_options_received {
113 /* PAWS/RTTM data */
114 int ts_recent_stamp;/* Time we stored ts_recent (for aging) */
115 u32 ts_recent; /* Time stamp to echo next */
116 u32 rcv_tsval; /* Time stamp value */
117 u32 rcv_tsecr; /* Time stamp echo reply */
118 u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */
119 tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
120 dsack : 1, /* D-SACK is scheduled */
121 wscale_ok : 1, /* Wscale seen on SYN packet */
122 sack_ok : 3, /* SACK seen on SYN packet */
123 smc_ok : 1, /* SMC seen on SYN packet */
124 snd_wscale : 4, /* Window scaling received from sender */
125 rcv_wscale : 4; /* Window scaling to send to receiver */
126 u8 saw_unknown:1, /* Received unknown option */
127 unused:7;
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
tcp_clear_options(struct tcp_options_received * rx_opt)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 last_oow_ack_time; /* last SYNACK */
165 u32 rcv_nxt; /* the ack # by SYNACK. For
166 * FastOpen it's the seq#
167 * after data-in-SYN.
168 */
169 u8 syn_tos;
170 #ifdef CONFIG_TCP_AO
171 u8 ao_keyid;
172 u8 ao_rcv_next;
173 bool used_tcp_ao;
174 #endif
175 };
176
tcp_rsk(const struct request_sock * req)177 static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
178 {
179 return (struct tcp_request_sock *)req;
180 }
181
tcp_rsk_used_ao(const struct request_sock * req)182 static inline bool tcp_rsk_used_ao(const struct request_sock *req)
183 {
184 #ifndef CONFIG_TCP_AO
185 return false;
186 #else
187 return tcp_rsk(req)->used_tcp_ao;
188 #endif
189 }
190
191 #define TCP_RMEM_TO_WIN_SCALE 8
192
193 struct tcp_sock {
194 /* Cacheline organization can be found documented in
195 * Documentation/networking/net_cachelines/tcp_sock.rst.
196 * Please update the document when adding new fields.
197 */
198
199 /* inet_connection_sock has to be the first member of tcp_sock */
200 struct inet_connection_sock inet_conn;
201
202 /* TX read-mostly hotpath cache lines */
203 __cacheline_group_begin(tcp_sock_read_tx);
204 /* timestamp of last sent data packet (for restart window) */
205 u32 max_window; /* Maximal window ever seen from peer */
206 u32 rcv_ssthresh; /* Current window clamp */
207 u32 reordering; /* Packet reordering metric. */
208 u32 notsent_lowat; /* TCP_NOTSENT_LOWAT */
209 u16 gso_segs; /* Max number of segs per GSO packet */
210 /* from STCP, retrans queue hinting */
211 struct sk_buff *lost_skb_hint;
212 struct sk_buff *retransmit_skb_hint;
213 __cacheline_group_end(tcp_sock_read_tx);
214
215 /* TXRX read-mostly hotpath cache lines */
216 __cacheline_group_begin(tcp_sock_read_txrx);
217 u32 tsoffset; /* timestamp offset */
218 u32 snd_wnd; /* The window we expect to receive */
219 u32 mss_cache; /* Cached effective mss, not including SACKS */
220 u32 snd_cwnd; /* Sending congestion window */
221 u32 prr_out; /* Total number of pkts sent during Recovery. */
222 u32 lost_out; /* Lost packets */
223 u32 sacked_out; /* SACK'd packets */
224 u16 tcp_header_len; /* Bytes of tcp header to send */
225 u8 scaling_ratio; /* see tcp_win_from_space() */
226 u8 chrono_type : 2, /* current chronograph type */
227 repair : 1,
228 tcp_usec_ts : 1, /* TSval values in usec */
229 is_sack_reneg:1, /* in recovery from loss with SACK reneg? */
230 is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */
231 __cacheline_group_end(tcp_sock_read_txrx);
232
233 /* RX read-mostly hotpath cache lines */
234 __cacheline_group_begin(tcp_sock_read_rx);
235 u32 copied_seq; /* Head of yet unread data */
236 u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
237 u32 snd_wl1; /* Sequence for window update */
238 u32 tlp_high_seq; /* snd_nxt at the time of TLP */
239 u32 rttvar_us; /* smoothed mdev_max */
240 u32 retrans_out; /* Retransmitted packets out */
241 u16 advmss; /* Advertised MSS */
242 u16 urg_data; /* Saved octet of OOB data and control flags */
243 u32 lost; /* Total data packets lost incl. rexmits */
244 struct minmax rtt_min;
245 /* OOO segments go in this rbtree. Socket lock must be held. */
246 struct rb_root out_of_order_queue;
247 u32 snd_ssthresh; /* Slow start size threshold */
248 u8 recvmsg_inq : 1;/* Indicate # of bytes in queue upon recvmsg */
249 __cacheline_group_end(tcp_sock_read_rx);
250
251 /* TX read-write hotpath cache lines */
252 __cacheline_group_begin(tcp_sock_write_tx) ____cacheline_aligned;
253 u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut
254 * The total number of segments sent.
255 */
256 u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut
257 * total number of data segments sent.
258 */
259 u64 bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut
260 * total number of data bytes sent.
261 */
262 u32 snd_sml; /* Last byte of the most recently transmitted small packet */
263 u32 chrono_start; /* Start time in jiffies of a TCP chrono */
264 u32 chrono_stat[3]; /* Time in jiffies for chrono_stat stats */
265 u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
266 u32 pushed_seq; /* Last pushed seq, required to talk to windows */
267 u32 lsndtime;
268 u32 mdev_us; /* medium deviation */
269 u32 rtt_seq; /* sequence number to update rttvar */
270 u64 tcp_wstamp_ns; /* departure time for next sent data packet */
271 struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */
272 struct sk_buff *highest_sack; /* skb just after the highest
273 * skb with SACKed bit set
274 * (validity guaranteed only if
275 * sacked_out > 0)
276 */
277 u8 ecn_flags; /* ECN status bits. */
278 __cacheline_group_end(tcp_sock_write_tx);
279
280 /* TXRX read-write hotpath cache lines */
281 __cacheline_group_begin(tcp_sock_write_txrx);
282 /*
283 * Header prediction flags
284 * 0x5?10 << 16 + snd_wnd in net byte order
285 */
286 __be32 pred_flags;
287 u64 tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */
288 u64 tcp_mstamp; /* most recent packet received/sent */
289 u32 rcv_nxt; /* What we want to receive next */
290 u32 snd_nxt; /* Next sequence we send */
291 u32 snd_una; /* First byte we want an ack for */
292 u32 window_clamp; /* Maximal window to advertise */
293 u32 srtt_us; /* smoothed round trip time << 3 in usecs */
294 u32 packets_out; /* Packets which are "in flight" */
295 u32 snd_up; /* Urgent pointer */
296 u32 delivered; /* Total data packets delivered incl. rexmits */
297 u32 delivered_ce; /* Like the above but only ECE marked packets */
298 u32 app_limited; /* limited until "delivered" reaches this val */
299 u32 rcv_wnd; /* Current receiver window */
300 /*
301 * Options received (usually on last packet, some only on SYN packets).
302 */
303 struct tcp_options_received rx_opt;
304 u8 nonagle : 4,/* Disable Nagle algorithm? */
305 rate_app_limited:1; /* rate_{delivered,interval_us} limited? */
306 __cacheline_group_end(tcp_sock_write_txrx);
307
308 /* RX read-write hotpath cache lines */
309 __cacheline_group_begin(tcp_sock_write_rx) __aligned(8);
310 u64 bytes_received;
311 /* RFC4898 tcpEStatsAppHCThruOctetsReceived
312 * sum(delta(rcv_nxt)), or how many bytes
313 * were acked.
314 */
315 u32 segs_in; /* RFC4898 tcpEStatsPerfSegsIn
316 * total number of segments in.
317 */
318 u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn
319 * total number of data segments in.
320 */
321 u32 rcv_wup; /* rcv_nxt on last window update sent */
322 u32 max_packets_out; /* max packets_out in last window */
323 u32 cwnd_usage_seq; /* right edge of cwnd usage tracking flight */
324 u32 rate_delivered; /* saved rate sample: packets delivered */
325 u32 rate_interval_us; /* saved rate sample: time elapsed */
326 u32 rcv_rtt_last_tsecr;
327 u64 first_tx_mstamp; /* start of window send phase */
328 u64 delivered_mstamp; /* time we reached "delivered" */
329 u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked
330 * sum(delta(snd_una)), or how many bytes
331 * were acked.
332 */
333 struct {
334 u32 rtt_us;
335 u32 seq;
336 u64 time;
337 } rcv_rtt_est;
338 /* Receiver queue space */
339 struct {
340 u32 space;
341 u32 seq;
342 u64 time;
343 } rcvq_space;
344 __cacheline_group_end(tcp_sock_write_rx);
345 /* End of Hot Path */
346
347 /*
348 * RFC793 variables by their proper names. This means you can
349 * read the code and the spec side by side (and laugh ...)
350 * See RFC793 and RFC1122. The RFC writes these in capitals.
351 */
352 u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups
353 * total number of DSACK blocks received
354 */
355 u32 compressed_ack_rcv_nxt;
356 struct list_head tsq_node; /* anchor in tsq_tasklet.head list */
357
358 /* Information of the most recently (s)acked skb */
359 struct tcp_rack {
360 u64 mstamp; /* (Re)sent time of the skb */
361 u32 rtt_us; /* Associated RTT */
362 u32 end_seq; /* Ending TCP sequence of the skb */
363 u32 last_delivered; /* tp->delivered at last reo_wnd adj */
364 u8 reo_wnd_steps; /* Allowed reordering window */
365 #define TCP_RACK_RECOVERY_THRESH 16
366 u8 reo_wnd_persist:5, /* No. of recovery since last adj */
367 dsack_seen:1, /* Whether DSACK seen after last adj */
368 advanced:1; /* mstamp advanced since last lost marking */
369 } rack;
370 u8 compressed_ack;
371 u8 dup_ack_counter:2,
372 tlp_retrans:1, /* TLP is a retransmission */
373 unused:5;
374 u8 thin_lto : 1,/* Use linear timeouts for thin streams */
375 fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */
376 fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */
377 fastopen_client_fail:2, /* reason why fastopen failed */
378 frto : 1;/* F-RTO (RFC5682) activated in CA_Loss */
379 u8 repair_queue;
380 u8 save_syn:2, /* Save headers of SYN packet */
381 syn_data:1, /* SYN includes data */
382 syn_fastopen:1, /* SYN includes Fast Open option */
383 syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */
384 syn_fastopen_ch:1, /* Active TFO re-enabling probe */
385 syn_data_acked:1;/* data in SYN is acked by SYN-ACK */
386
387 u8 keepalive_probes; /* num of allowed keep alive probes */
388 u32 tcp_tx_delay; /* delay (in usec) added to TX packets */
389
390 /* RTT measurement */
391 u32 mdev_max_us; /* maximal mdev for the last rtt period */
392
393 u32 reord_seen; /* number of data packet reordering events */
394
395 /*
396 * Slow start and congestion control (see also Nagle, and Karn & Partridge)
397 */
398 u32 snd_cwnd_cnt; /* Linear increase counter */
399 u32 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
400 u32 snd_cwnd_used;
401 u32 snd_cwnd_stamp;
402 u32 prior_cwnd; /* cwnd right before starting loss recovery */
403 u32 prr_delivered; /* Number of newly delivered packets to
404 * receiver in Recovery. */
405 u32 last_oow_ack_time; /* timestamp of last out-of-window ACK */
406
407 struct hrtimer pacing_timer;
408 struct hrtimer compressed_ack_timer;
409
410 struct sk_buff *ooo_last_skb; /* cache rb_last(out_of_order_queue) */
411
412 /* SACKs data, these 2 need to be together (see tcp_options_write) */
413 struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
414 struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
415
416 struct tcp_sack_block recv_sack_cache[4];
417
418 int lost_cnt_hint;
419
420 u32 prior_ssthresh; /* ssthresh saved at recovery start */
421 u32 high_seq; /* snd_nxt at onset of congestion */
422
423 u32 retrans_stamp; /* Timestamp of the last retransmit,
424 * also used in SYN-SENT to remember stamp of
425 * the first SYN. */
426 u32 undo_marker; /* snd_una upon a new recovery episode. */
427 int undo_retrans; /* number of undoable retransmissions. */
428 u64 bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans
429 * Total data bytes retransmitted
430 */
431 u32 total_retrans; /* Total retransmits for entire connection */
432 u32 rto_stamp; /* Start time (ms) of last CA_Loss recovery */
433 u16 total_rto; /* Total number of RTO timeouts, including
434 * SYN/SYN-ACK and recurring timeouts.
435 */
436 u16 total_rto_recoveries; /* Total number of RTO recoveries,
437 * including any unfinished recovery.
438 */
439 u32 total_rto_time; /* ms spent in (completed) RTO recoveries. */
440
441 u32 urg_seq; /* Seq of received urgent pointer */
442 unsigned int keepalive_time; /* time before keep alive takes place */
443 unsigned int keepalive_intvl; /* time interval between keep alive probes */
444
445 int linger2;
446
447
448 /* Sock_ops bpf program related variables */
449 #ifdef CONFIG_BPF
450 u8 bpf_sock_ops_cb_flags; /* Control calling BPF programs
451 * values defined in uapi/linux/tcp.h
452 */
453 u8 bpf_chg_cc_inprogress:1; /* In the middle of
454 * bpf_setsockopt(TCP_CONGESTION),
455 * it is to avoid the bpf_tcp_cc->init()
456 * to recur itself by calling
457 * bpf_setsockopt(TCP_CONGESTION, "itself").
458 */
459 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) (TP->bpf_sock_ops_cb_flags & ARG)
460 #else
461 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) 0
462 #endif
463
464 u16 timeout_rehash; /* Timeout-triggered rehash attempts */
465
466 u32 rcv_ooopack; /* Received out-of-order packets, for tcpinfo */
467
468 /* TCP-specific MTU probe information. */
469 struct {
470 u32 probe_seq_start;
471 u32 probe_seq_end;
472 } mtu_probe;
473 u32 plb_rehash; /* PLB-triggered rehash attempts */
474 u32 mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG
475 * while socket was owned by user.
476 */
477 #if IS_ENABLED(CONFIG_MPTCP)
478 bool is_mptcp;
479 #endif
480 #if IS_ENABLED(CONFIG_SMC)
481 bool syn_smc; /* SYN includes SMC */
482 bool (*smc_hs_congested)(const struct sock *sk);
483 #endif
484
485 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
486 /* TCP AF-Specific parts; only used by TCP-AO/MD5 Signature support so far */
487 const struct tcp_sock_af_ops *af_specific;
488
489 #ifdef CONFIG_TCP_MD5SIG
490 /* TCP MD5 Signature Option information */
491 struct tcp_md5sig_info __rcu *md5sig_info;
492 #endif
493 #ifdef CONFIG_TCP_AO
494 struct tcp_ao_info __rcu *ao_info;
495 #endif
496 #endif
497
498 /* TCP fastopen related information */
499 struct tcp_fastopen_request *fastopen_req;
500 /* fastopen_rsk points to request_sock that resulted in this big
501 * socket. Used to retransmit SYNACKs etc.
502 */
503 struct request_sock __rcu *fastopen_rsk;
504 struct saved_syn *saved_syn;
505
506 ANDROID_KABI_RESERVE(1);
507 ANDROID_OEM_DATA(1);
508 };
509
510 enum tsq_enum {
511 TSQ_THROTTLED,
512 TSQ_QUEUED,
513 TCP_TSQ_DEFERRED, /* tcp_tasklet_func() found socket was owned */
514 TCP_WRITE_TIMER_DEFERRED, /* tcp_write_timer() found socket was owned */
515 TCP_DELACK_TIMER_DEFERRED, /* tcp_delack_timer() found socket was owned */
516 TCP_MTU_REDUCED_DEFERRED, /* tcp_v{4|6}_err() could not call
517 * tcp_v{4|6}_mtu_reduced()
518 */
519 TCP_ACK_DEFERRED, /* TX pure ack is deferred */
520 };
521
522 enum tsq_flags {
523 TSQF_THROTTLED = BIT(TSQ_THROTTLED),
524 TSQF_QUEUED = BIT(TSQ_QUEUED),
525 TCPF_TSQ_DEFERRED = BIT(TCP_TSQ_DEFERRED),
526 TCPF_WRITE_TIMER_DEFERRED = BIT(TCP_WRITE_TIMER_DEFERRED),
527 TCPF_DELACK_TIMER_DEFERRED = BIT(TCP_DELACK_TIMER_DEFERRED),
528 TCPF_MTU_REDUCED_DEFERRED = BIT(TCP_MTU_REDUCED_DEFERRED),
529 TCPF_ACK_DEFERRED = BIT(TCP_ACK_DEFERRED),
530 };
531
532 #define tcp_sk(ptr) container_of_const(ptr, struct tcp_sock, inet_conn.icsk_inet.sk)
533
534 /* Variant of tcp_sk() upgrading a const sock to a read/write tcp socket.
535 * Used in context of (lockless) tcp listeners.
536 */
537 #define tcp_sk_rw(ptr) container_of(ptr, struct tcp_sock, inet_conn.icsk_inet.sk)
538
539 struct tcp_timewait_sock {
540 struct inet_timewait_sock tw_sk;
541 #define tw_rcv_nxt tw_sk.__tw_common.skc_tw_rcv_nxt
542 #define tw_snd_nxt tw_sk.__tw_common.skc_tw_snd_nxt
543 u32 tw_rcv_wnd;
544 u32 tw_ts_offset;
545 u32 tw_ts_recent;
546
547 /* The time we sent the last out-of-window ACK: */
548 u32 tw_last_oow_ack_time;
549
550 int tw_ts_recent_stamp;
551 u32 tw_tx_delay;
552 #ifdef CONFIG_TCP_MD5SIG
553 struct tcp_md5sig_key *tw_md5_key;
554 #endif
555 #ifdef CONFIG_TCP_AO
556 struct tcp_ao_info __rcu *ao_info;
557 #endif
558 };
559
tcp_twsk(const struct sock * sk)560 static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
561 {
562 return (struct tcp_timewait_sock *)sk;
563 }
564
tcp_passive_fastopen(const struct sock * sk)565 static inline bool tcp_passive_fastopen(const struct sock *sk)
566 {
567 return sk->sk_state == TCP_SYN_RECV &&
568 rcu_access_pointer(tcp_sk(sk)->fastopen_rsk) != NULL;
569 }
570
fastopen_queue_tune(struct sock * sk,int backlog)571 static inline void fastopen_queue_tune(struct sock *sk, int backlog)
572 {
573 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
574 int somaxconn = READ_ONCE(sock_net(sk)->core.sysctl_somaxconn);
575
576 WRITE_ONCE(queue->fastopenq.max_qlen, min_t(unsigned int, backlog, somaxconn));
577 }
578
tcp_move_syn(struct tcp_sock * tp,struct request_sock * req)579 static inline void tcp_move_syn(struct tcp_sock *tp,
580 struct request_sock *req)
581 {
582 tp->saved_syn = req->saved_syn;
583 req->saved_syn = NULL;
584 }
585
tcp_saved_syn_free(struct tcp_sock * tp)586 static inline void tcp_saved_syn_free(struct tcp_sock *tp)
587 {
588 kfree(tp->saved_syn);
589 tp->saved_syn = NULL;
590 }
591
tcp_saved_syn_len(const struct saved_syn * saved_syn)592 static inline u32 tcp_saved_syn_len(const struct saved_syn *saved_syn)
593 {
594 return saved_syn->mac_hdrlen + saved_syn->network_hdrlen +
595 saved_syn->tcp_hdrlen;
596 }
597
598 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk,
599 const struct sk_buff *orig_skb,
600 const struct sk_buff *ack_skb);
601
tcp_mss_clamp(const struct tcp_sock * tp,u16 mss)602 static inline u16 tcp_mss_clamp(const struct tcp_sock *tp, u16 mss)
603 {
604 /* We use READ_ONCE() here because socket might not be locked.
605 * This happens for listeners.
606 */
607 u16 user_mss = READ_ONCE(tp->rx_opt.user_mss);
608
609 return (user_mss && user_mss < mss) ? user_mss : mss;
610 }
611
612 int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, int pcount,
613 int shiftlen);
614
615 void __tcp_sock_set_cork(struct sock *sk, bool on);
616 void tcp_sock_set_cork(struct sock *sk, bool on);
617 int tcp_sock_set_keepcnt(struct sock *sk, int val);
618 int tcp_sock_set_keepidle_locked(struct sock *sk, int val);
619 int tcp_sock_set_keepidle(struct sock *sk, int val);
620 int tcp_sock_set_keepintvl(struct sock *sk, int val);
621 void __tcp_sock_set_nodelay(struct sock *sk, bool on);
622 void tcp_sock_set_nodelay(struct sock *sk);
623 void tcp_sock_set_quickack(struct sock *sk, int val);
624 int tcp_sock_set_syncnt(struct sock *sk, int val);
625 int tcp_sock_set_user_timeout(struct sock *sk, int val);
626
dst_tcp_usec_ts(const struct dst_entry * dst)627 static inline bool dst_tcp_usec_ts(const struct dst_entry *dst)
628 {
629 return dst_feature(dst, RTAX_FEATURE_TCP_USEC_TS);
630 }
631
632 #endif /* _LINUX_TCP_H */
633