interconnect: qcom: icc-rpm: Fix peak rate calculation
[linux-2.6-microblaze.git] / include / linux / tcp.h
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      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
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         u8                              maclen;
173 #endif
174 };
175
176 static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
177 {
178         return (struct tcp_request_sock *)req;
179 }
180
181 static inline bool tcp_rsk_used_ao(const struct request_sock *req)
182 {
183         /* The real length of MAC is saved in the request socket,
184          * signing anything with zero-length makes no sense, so here is
185          * a little hack..
186          */
187 #ifndef CONFIG_TCP_AO
188         return false;
189 #else
190         return tcp_rsk(req)->maclen != 0;
191 #endif
192 }
193
194 #define TCP_RMEM_TO_WIN_SCALE 8
195
196 struct tcp_sock {
197         /* inet_connection_sock has to be the first member of tcp_sock */
198         struct inet_connection_sock     inet_conn;
199         u16     tcp_header_len; /* Bytes of tcp header to send          */
200         u16     gso_segs;       /* Max number of segs per GSO packet    */
201
202 /*
203  *      Header prediction flags
204  *      0x5?10 << 16 + snd_wnd in net byte order
205  */
206         __be32  pred_flags;
207
208 /*
209  *      RFC793 variables by their proper names. This means you can
210  *      read the code and the spec side by side (and laugh ...)
211  *      See RFC793 and RFC1122. The RFC writes these in capitals.
212  */
213         u64     bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived
214                                  * sum(delta(rcv_nxt)), or how many bytes
215                                  * were acked.
216                                  */
217         u32     segs_in;        /* RFC4898 tcpEStatsPerfSegsIn
218                                  * total number of segments in.
219                                  */
220         u32     data_segs_in;   /* RFC4898 tcpEStatsPerfDataSegsIn
221                                  * total number of data segments in.
222                                  */
223         u32     rcv_nxt;        /* What we want to receive next         */
224         u32     copied_seq;     /* Head of yet unread data              */
225         u32     rcv_wup;        /* rcv_nxt on last window update sent   */
226         u32     snd_nxt;        /* Next sequence we send                */
227         u32     segs_out;       /* RFC4898 tcpEStatsPerfSegsOut
228                                  * The total number of segments sent.
229                                  */
230         u32     data_segs_out;  /* RFC4898 tcpEStatsPerfDataSegsOut
231                                  * total number of data segments sent.
232                                  */
233         u64     bytes_sent;     /* RFC4898 tcpEStatsPerfHCDataOctetsOut
234                                  * total number of data bytes sent.
235                                  */
236         u64     bytes_acked;    /* RFC4898 tcpEStatsAppHCThruOctetsAcked
237                                  * sum(delta(snd_una)), or how many bytes
238                                  * were acked.
239                                  */
240         u32     dsack_dups;     /* RFC4898 tcpEStatsStackDSACKDups
241                                  * total number of DSACK blocks received
242                                  */
243         u32     snd_una;        /* First byte we want an ack for        */
244         u32     snd_sml;        /* Last byte of the most recently transmitted small packet */
245         u32     rcv_tstamp;     /* timestamp of last received ACK (for keepalives) */
246         u32     lsndtime;       /* timestamp of last sent data packet (for restart window) */
247         u32     last_oow_ack_time;  /* timestamp of last out-of-window ACK */
248         u32     compressed_ack_rcv_nxt;
249
250         u32     tsoffset;       /* timestamp offset */
251
252         struct list_head tsq_node; /* anchor in tsq_tasklet.head list */
253         struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */
254
255         u32     snd_wl1;        /* Sequence for window update           */
256         u32     snd_wnd;        /* The window we expect to receive      */
257         u32     max_window;     /* Maximal window ever seen from peer   */
258         u32     mss_cache;      /* Cached effective mss, not including SACKS */
259
260         u32     window_clamp;   /* Maximal window to advertise          */
261         u32     rcv_ssthresh;   /* Current window clamp                 */
262         u8      scaling_ratio;  /* see tcp_win_from_space() */
263         /* Information of the most recently (s)acked skb */
264         struct tcp_rack {
265                 u64 mstamp; /* (Re)sent time of the skb */
266                 u32 rtt_us;  /* Associated RTT */
267                 u32 end_seq; /* Ending TCP sequence of the skb */
268                 u32 last_delivered; /* tp->delivered at last reo_wnd adj */
269                 u8 reo_wnd_steps;   /* Allowed reordering window */
270 #define TCP_RACK_RECOVERY_THRESH 16
271                 u8 reo_wnd_persist:5, /* No. of recovery since last adj */
272                    dsack_seen:1, /* Whether DSACK seen after last adj */
273                    advanced:1;   /* mstamp advanced since last lost marking */
274         } rack;
275         u16     advmss;         /* Advertised MSS                       */
276         u8      compressed_ack;
277         u8      dup_ack_counter:2,
278                 tlp_retrans:1,  /* TLP is a retransmission */
279                 tcp_usec_ts:1, /* TSval values in usec */
280                 unused:4;
281         u32     chrono_start;   /* Start time in jiffies of a TCP chrono */
282         u32     chrono_stat[3]; /* Time in jiffies for chrono_stat stats */
283         u8      chrono_type:2,  /* current chronograph type */
284                 rate_app_limited:1,  /* rate_{delivered,interval_us} limited? */
285                 fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */
286                 fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */
287                 is_sack_reneg:1,    /* in recovery from loss with SACK reneg? */
288                 fastopen_client_fail:2; /* reason why fastopen failed */
289         u8      nonagle     : 4,/* Disable Nagle algorithm?             */
290                 thin_lto    : 1,/* Use linear timeouts for thin streams */
291                 recvmsg_inq : 1,/* Indicate # of bytes in queue upon recvmsg */
292                 repair      : 1,
293                 frto        : 1;/* F-RTO (RFC5682) activated in CA_Loss */
294         u8      repair_queue;
295         u8      save_syn:2,     /* Save headers of SYN packet */
296                 syn_data:1,     /* SYN includes data */
297                 syn_fastopen:1, /* SYN includes Fast Open option */
298                 syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */
299                 syn_fastopen_ch:1, /* Active TFO re-enabling probe */
300                 syn_data_acked:1,/* data in SYN is acked by SYN-ACK */
301                 is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */
302         u32     tlp_high_seq;   /* snd_nxt at the time of TLP */
303
304         u32     tcp_tx_delay;   /* delay (in usec) added to TX packets */
305         u64     tcp_wstamp_ns;  /* departure time for next sent data packet */
306         u64     tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */
307
308 /* RTT measurement */
309         u64     tcp_mstamp;     /* most recent packet received/sent */
310         u32     srtt_us;        /* smoothed round trip time << 3 in usecs */
311         u32     mdev_us;        /* medium deviation                     */
312         u32     mdev_max_us;    /* maximal mdev for the last rtt period */
313         u32     rttvar_us;      /* smoothed mdev_max                    */
314         u32     rtt_seq;        /* sequence number to update rttvar     */
315         struct  minmax rtt_min;
316
317         u32     packets_out;    /* Packets which are "in flight"        */
318         u32     retrans_out;    /* Retransmitted packets out            */
319         u32     max_packets_out;  /* max packets_out in last window */
320         u32     cwnd_usage_seq;  /* right edge of cwnd usage tracking flight */
321
322         u16     urg_data;       /* Saved octet of OOB data and control flags */
323         u8      ecn_flags;      /* ECN status bits.                     */
324         u8      keepalive_probes; /* num of allowed keep alive probes   */
325         u32     reordering;     /* Packet reordering metric.            */
326         u32     reord_seen;     /* number of data packet reordering events */
327         u32     snd_up;         /* Urgent pointer               */
328
329 /*
330  *      Options received (usually on last packet, some only on SYN packets).
331  */
332         struct tcp_options_received rx_opt;
333
334 /*
335  *      Slow start and congestion control (see also Nagle, and Karn & Partridge)
336  */
337         u32     snd_ssthresh;   /* Slow start size threshold            */
338         u32     snd_cwnd;       /* Sending congestion window            */
339         u32     snd_cwnd_cnt;   /* Linear increase counter              */
340         u32     snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
341         u32     snd_cwnd_used;
342         u32     snd_cwnd_stamp;
343         u32     prior_cwnd;     /* cwnd right before starting loss recovery */
344         u32     prr_delivered;  /* Number of newly delivered packets to
345                                  * receiver in Recovery. */
346         u32     prr_out;        /* Total number of pkts sent during Recovery. */
347         u32     delivered;      /* Total data packets delivered incl. rexmits */
348         u32     delivered_ce;   /* Like the above but only ECE marked packets */
349         u32     lost;           /* Total data packets lost incl. rexmits */
350         u32     app_limited;    /* limited until "delivered" reaches this val */
351         u64     first_tx_mstamp;  /* start of window send phase */
352         u64     delivered_mstamp; /* time we reached "delivered" */
353         u32     rate_delivered;    /* saved rate sample: packets delivered */
354         u32     rate_interval_us;  /* saved rate sample: time elapsed */
355
356         u32     rcv_wnd;        /* Current receiver window              */
357         u32     write_seq;      /* Tail(+1) of data held in tcp send buffer */
358         u32     notsent_lowat;  /* TCP_NOTSENT_LOWAT */
359         u32     pushed_seq;     /* Last pushed seq, required to talk to windows */
360         u32     lost_out;       /* Lost packets                 */
361         u32     sacked_out;     /* SACK'd packets                       */
362
363         struct hrtimer  pacing_timer;
364         struct hrtimer  compressed_ack_timer;
365
366         /* from STCP, retrans queue hinting */
367         struct sk_buff* lost_skb_hint;
368         struct sk_buff *retransmit_skb_hint;
369
370         /* OOO segments go in this rbtree. Socket lock must be held. */
371         struct rb_root  out_of_order_queue;
372         struct sk_buff  *ooo_last_skb; /* cache rb_last(out_of_order_queue) */
373
374         /* SACKs data, these 2 need to be together (see tcp_options_write) */
375         struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
376         struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
377
378         struct tcp_sack_block recv_sack_cache[4];
379
380         struct sk_buff *highest_sack;   /* skb just after the highest
381                                          * skb with SACKed bit set
382                                          * (validity guaranteed only if
383                                          * sacked_out > 0)
384                                          */
385
386         int     lost_cnt_hint;
387
388         u32     prior_ssthresh; /* ssthresh saved at recovery start     */
389         u32     high_seq;       /* snd_nxt at onset of congestion       */
390
391         u32     retrans_stamp;  /* Timestamp of the last retransmit,
392                                  * also used in SYN-SENT to remember stamp of
393                                  * the first SYN. */
394         u32     undo_marker;    /* snd_una upon a new recovery episode. */
395         int     undo_retrans;   /* number of undoable retransmissions. */
396         u64     bytes_retrans;  /* RFC4898 tcpEStatsPerfOctetsRetrans
397                                  * Total data bytes retransmitted
398                                  */
399         u32     total_retrans;  /* Total retransmits for entire connection */
400         u32     rto_stamp;      /* Start time (ms) of last CA_Loss recovery */
401         u16     total_rto;      /* Total number of RTO timeouts, including
402                                  * SYN/SYN-ACK and recurring timeouts.
403                                  */
404         u16     total_rto_recoveries;   /* Total number of RTO recoveries,
405                                          * including any unfinished recovery.
406                                          */
407         u32     total_rto_time; /* ms spent in (completed) RTO recoveries. */
408
409         u32     urg_seq;        /* Seq of received urgent pointer */
410         unsigned int            keepalive_time;   /* time before keep alive takes place */
411         unsigned int            keepalive_intvl;  /* time interval between keep alive probes */
412
413         int                     linger2;
414
415
416 /* Sock_ops bpf program related variables */
417 #ifdef CONFIG_BPF
418         u8      bpf_sock_ops_cb_flags;  /* Control calling BPF programs
419                                          * values defined in uapi/linux/tcp.h
420                                          */
421         u8      bpf_chg_cc_inprogress:1; /* In the middle of
422                                           * bpf_setsockopt(TCP_CONGESTION),
423                                           * it is to avoid the bpf_tcp_cc->init()
424                                           * to recur itself by calling
425                                           * bpf_setsockopt(TCP_CONGESTION, "itself").
426                                           */
427 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) (TP->bpf_sock_ops_cb_flags & ARG)
428 #else
429 #define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) 0
430 #endif
431
432         u16 timeout_rehash;     /* Timeout-triggered rehash attempts */
433
434         u32 rcv_ooopack; /* Received out-of-order packets, for tcpinfo */
435
436 /* Receiver side RTT estimation */
437         u32 rcv_rtt_last_tsecr;
438         struct {
439                 u32     rtt_us;
440                 u32     seq;
441                 u64     time;
442         } rcv_rtt_est;
443
444 /* Receiver queue space */
445         struct {
446                 u32     space;
447                 u32     seq;
448                 u64     time;
449         } rcvq_space;
450
451 /* TCP-specific MTU probe information. */
452         struct {
453                 u32               probe_seq_start;
454                 u32               probe_seq_end;
455         } mtu_probe;
456         u32     plb_rehash;     /* PLB-triggered rehash attempts */
457         u32     mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG
458                            * while socket was owned by user.
459                            */
460 #if IS_ENABLED(CONFIG_MPTCP)
461         bool    is_mptcp;
462 #endif
463 #if IS_ENABLED(CONFIG_SMC)
464         bool    (*smc_hs_congested)(const struct sock *sk);
465         bool    syn_smc;        /* SYN includes SMC */
466 #endif
467
468 #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
469 /* TCP AF-Specific parts; only used by TCP-AO/MD5 Signature support so far */
470         const struct tcp_sock_af_ops    *af_specific;
471
472 #ifdef CONFIG_TCP_MD5SIG
473 /* TCP MD5 Signature Option information */
474         struct tcp_md5sig_info  __rcu *md5sig_info;
475 #endif
476 #ifdef CONFIG_TCP_AO
477         struct tcp_ao_info      __rcu *ao_info;
478 #endif
479 #endif
480
481 /* TCP fastopen related information */
482         struct tcp_fastopen_request *fastopen_req;
483         /* fastopen_rsk points to request_sock that resulted in this big
484          * socket. Used to retransmit SYNACKs etc.
485          */
486         struct request_sock __rcu *fastopen_rsk;
487         struct saved_syn *saved_syn;
488 };
489
490 enum tsq_enum {
491         TSQ_THROTTLED,
492         TSQ_QUEUED,
493         TCP_TSQ_DEFERRED,          /* tcp_tasklet_func() found socket was owned */
494         TCP_WRITE_TIMER_DEFERRED,  /* tcp_write_timer() found socket was owned */
495         TCP_DELACK_TIMER_DEFERRED, /* tcp_delack_timer() found socket was owned */
496         TCP_MTU_REDUCED_DEFERRED,  /* tcp_v{4|6}_err() could not call
497                                     * tcp_v{4|6}_mtu_reduced()
498                                     */
499         TCP_ACK_DEFERRED,          /* TX pure ack is deferred */
500 };
501
502 enum tsq_flags {
503         TSQF_THROTTLED                  = BIT(TSQ_THROTTLED),
504         TSQF_QUEUED                     = BIT(TSQ_QUEUED),
505         TCPF_TSQ_DEFERRED               = BIT(TCP_TSQ_DEFERRED),
506         TCPF_WRITE_TIMER_DEFERRED       = BIT(TCP_WRITE_TIMER_DEFERRED),
507         TCPF_DELACK_TIMER_DEFERRED      = BIT(TCP_DELACK_TIMER_DEFERRED),
508         TCPF_MTU_REDUCED_DEFERRED       = BIT(TCP_MTU_REDUCED_DEFERRED),
509         TCPF_ACK_DEFERRED               = BIT(TCP_ACK_DEFERRED),
510 };
511
512 #define tcp_sk(ptr) container_of_const(ptr, struct tcp_sock, inet_conn.icsk_inet.sk)
513
514 /* Variant of tcp_sk() upgrading a const sock to a read/write tcp socket.
515  * Used in context of (lockless) tcp listeners.
516  */
517 #define tcp_sk_rw(ptr) container_of(ptr, struct tcp_sock, inet_conn.icsk_inet.sk)
518
519 struct tcp_timewait_sock {
520         struct inet_timewait_sock tw_sk;
521 #define tw_rcv_nxt tw_sk.__tw_common.skc_tw_rcv_nxt
522 #define tw_snd_nxt tw_sk.__tw_common.skc_tw_snd_nxt
523         u32                       tw_rcv_wnd;
524         u32                       tw_ts_offset;
525         u32                       tw_ts_recent;
526
527         /* The time we sent the last out-of-window ACK: */
528         u32                       tw_last_oow_ack_time;
529
530         int                       tw_ts_recent_stamp;
531         u32                       tw_tx_delay;
532 #ifdef CONFIG_TCP_MD5SIG
533         struct tcp_md5sig_key     *tw_md5_key;
534 #endif
535 #ifdef CONFIG_TCP_AO
536         struct tcp_ao_info      __rcu *ao_info;
537 #endif
538 };
539
540 static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
541 {
542         return (struct tcp_timewait_sock *)sk;
543 }
544
545 static inline bool tcp_passive_fastopen(const struct sock *sk)
546 {
547         return sk->sk_state == TCP_SYN_RECV &&
548                rcu_access_pointer(tcp_sk(sk)->fastopen_rsk) != NULL;
549 }
550
551 static inline void fastopen_queue_tune(struct sock *sk, int backlog)
552 {
553         struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
554         int somaxconn = READ_ONCE(sock_net(sk)->core.sysctl_somaxconn);
555
556         WRITE_ONCE(queue->fastopenq.max_qlen, min_t(unsigned int, backlog, somaxconn));
557 }
558
559 static inline void tcp_move_syn(struct tcp_sock *tp,
560                                 struct request_sock *req)
561 {
562         tp->saved_syn = req->saved_syn;
563         req->saved_syn = NULL;
564 }
565
566 static inline void tcp_saved_syn_free(struct tcp_sock *tp)
567 {
568         kfree(tp->saved_syn);
569         tp->saved_syn = NULL;
570 }
571
572 static inline u32 tcp_saved_syn_len(const struct saved_syn *saved_syn)
573 {
574         return saved_syn->mac_hdrlen + saved_syn->network_hdrlen +
575                 saved_syn->tcp_hdrlen;
576 }
577
578 struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk,
579                                                const struct sk_buff *orig_skb,
580                                                const struct sk_buff *ack_skb);
581
582 static inline u16 tcp_mss_clamp(const struct tcp_sock *tp, u16 mss)
583 {
584         /* We use READ_ONCE() here because socket might not be locked.
585          * This happens for listeners.
586          */
587         u16 user_mss = READ_ONCE(tp->rx_opt.user_mss);
588
589         return (user_mss && user_mss < mss) ? user_mss : mss;
590 }
591
592 int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, int pcount,
593                   int shiftlen);
594
595 void __tcp_sock_set_cork(struct sock *sk, bool on);
596 void tcp_sock_set_cork(struct sock *sk, bool on);
597 int tcp_sock_set_keepcnt(struct sock *sk, int val);
598 int tcp_sock_set_keepidle_locked(struct sock *sk, int val);
599 int tcp_sock_set_keepidle(struct sock *sk, int val);
600 int tcp_sock_set_keepintvl(struct sock *sk, int val);
601 void __tcp_sock_set_nodelay(struct sock *sk, bool on);
602 void tcp_sock_set_nodelay(struct sock *sk);
603 void tcp_sock_set_quickack(struct sock *sk, int val);
604 int tcp_sock_set_syncnt(struct sock *sk, int val);
605 int tcp_sock_set_user_timeout(struct sock *sk, int val);
606
607 static inline bool dst_tcp_usec_ts(const struct dst_entry *dst)
608 {
609         return dst_feature(dst, RTAX_FEATURE_TCP_USEC_TS);
610 }
611
612 #endif  /* _LINUX_TCP_H */