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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Definitions for the TCP protocol.
7 *
8 * Version: @(#)tcp.h 1.0.2 04/28/93
9 *
10 * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17#ifndef _LINUX_TCP_H
18#define _LINUX_TCP_H
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/skbuff.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <net/sock.h>
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -070023#include <net/inet_connection_sock.h>
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -070024#include <net/inet_timewait_sock.h>
David Howells607ca462012-10-13 10:46:48 +010025#include <uapi/linux/tcp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -070027static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb)
28{
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -070029 return (struct tcphdr *)skb_transport_header(skb);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -070030}
31
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -070032static inline unsigned int tcp_hdrlen(const struct sk_buff *skb)
33{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -070034 return tcp_hdr(skb)->doff * 4;
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -070035}
36
Joseph Gasparakis6a674e92012-12-07 14:14:14 +000037static inline struct tcphdr *inner_tcp_hdr(const struct sk_buff *skb)
38{
39 return (struct tcphdr *)skb_inner_transport_header(skb);
40}
41
42static inline unsigned int inner_tcp_hdrlen(const struct sk_buff *skb)
43{
44 return inner_tcp_hdr(skb)->doff * 4;
45}
46
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -070047static inline unsigned int tcp_optlen(const struct sk_buff *skb)
48{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -070049 return (tcp_hdr(skb)->doff - 5) * 4;
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -070050}
51
Yuchung Cheng2100c8d2012-07-19 06:43:05 +000052/* TCP Fast Open */
53#define TCP_FASTOPEN_COOKIE_MIN 4 /* Min Fast Open Cookie size in bytes */
54#define TCP_FASTOPEN_COOKIE_MAX 16 /* Max Fast Open Cookie size in bytes */
Jerry Chu10467162012-08-31 12:29:11 +000055#define TCP_FASTOPEN_COOKIE_SIZE 8 /* the size employed by this impl. */
Yuchung Cheng2100c8d2012-07-19 06:43:05 +000056
57/* TCP Fast Open Cookie as stored in memory */
58struct tcp_fastopen_cookie {
59 s8 len;
60 u8 val[TCP_FASTOPEN_COOKIE_MAX];
Daniel Lee7f9b8382015-04-06 14:37:26 -070061 bool exp; /* In RFC6994 experimental option format */
Yuchung Cheng2100c8d2012-07-19 06:43:05 +000062};
63
Linus Torvalds1da177e2005-04-16 15:20:36 -070064/* This defines a selective acknowledgement block. */
Al Viro269bd272006-09-27 18:32:28 -070065struct tcp_sack_block_wire {
66 __be32 start_seq;
67 __be32 end_seq;
68};
69
Linus Torvalds1da177e2005-04-16 15:20:36 -070070struct tcp_sack_block {
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -020071 u32 start_seq;
72 u32 end_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073};
74
Vijay Subramanianab562222011-12-20 13:23:24 +000075/*These are used to set the sack_ok field in struct tcp_options_received */
76#define TCP_SACK_SEEN (1 << 0) /*1 = peer is SACK capable, */
77#define TCP_FACK_ENABLED (1 << 1) /*1 = FACK is enabled locally*/
78#define TCP_DSACK_SEEN (1 << 2) /*1 = DSACK was received from peer*/
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080struct tcp_options_received {
81/* PAWS/RTTM data */
82 long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -020083 u32 ts_recent; /* Time stamp to echo next */
84 u32 rcv_tsval; /* Time stamp value */
85 u32 rcv_tsecr; /* Time stamp echo reply */
86 u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
88 dsack : 1, /* D-SACK is scheduled */
89 wscale_ok : 1, /* Wscale seen on SYN packet */
90 sack_ok : 4, /* SACK seen on SYN packet */
91 snd_wscale : 4, /* Window scaling received from sender */
92 rcv_wscale : 4; /* Window scaling to send to receiver */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -020093 u8 num_sacks; /* Number of SACK blocks */
William Allen Simpson435cf552009-12-02 18:17:05 +000094 u16 user_mss; /* mss requested by user in ioctl */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -020095 u16 mss_clamp; /* Maximal mss, negotiated at connection setup */
Linus Torvalds1da177e2005-04-16 15:20:36 -070096};
97
William Allen Simpson519855c2009-12-02 18:14:19 +000098static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
99{
William Allen Simpson435cf552009-12-02 18:17:05 +0000100 rx_opt->tstamp_ok = rx_opt->sack_ok = 0;
101 rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
William Allen Simpson519855c2009-12-02 18:14:19 +0000102}
103
Adam Langley4389dde2008-07-19 00:07:02 -0700104/* This is the max number of SACKS that we'll generate and process. It's safe
William Allen Simpson435cf552009-12-02 18:17:05 +0000105 * to increase this, although since:
Adam Langley4389dde2008-07-19 00:07:02 -0700106 * size = TCPOLEN_SACK_BASE_ALIGNED (4) + n * TCPOLEN_SACK_PERBLOCK (8)
107 * only four options will fit in a standard TCP header */
108#define TCP_NUM_SACKS 4
109
William Allen Simpson435cf552009-12-02 18:17:05 +0000110struct tcp_request_sock_ops;
111
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700112struct tcp_request_sock {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800113 struct inet_request_sock req;
Stephen Hemmingerb2e4b3d2009-09-01 19:25:03 +0000114 const struct tcp_request_sock_ops *af_specific;
Eric Dumazet9439ce02015-03-17 18:32:29 -0700115 bool tfo_listener;
William Allen Simpson435cf552009-12-02 18:17:05 +0000116 u32 rcv_isn;
117 u32 snt_isn;
Jerry Chu9ad7c042011-06-08 11:08:38 +0000118 u32 snt_synack; /* synack sent time */
Neal Cardwella9b2c062015-02-06 16:04:39 -0500119 u32 last_oow_ack_time; /* last SYNACK */
Jerry Chu10467162012-08-31 12:29:11 +0000120 u32 rcv_nxt; /* the ack # by SYNACK. For
121 * FastOpen it's the seq#
122 * after data-in-SYN.
123 */
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700124};
125
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700126static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700127{
128 return (struct tcp_request_sock *)req;
129}
130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131struct tcp_sock {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700132 /* inet_connection_sock has to be the first member of tcp_sock */
133 struct inet_connection_sock inet_conn;
Arnaldo Carvalho de Melo2ff52f22006-11-28 00:48:32 -0200134 u16 tcp_header_len; /* Bytes of tcp header to send */
Eric Dumazet605ad7f2014-12-07 12:22:18 -0800135 u16 gso_segs; /* Max number of segs per GSO packet */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137/*
138 * Header prediction flags
139 * 0x5?10 << 16 + snd_wnd in net byte order
140 */
Al Virodddc93c2006-09-27 18:32:46 -0700141 __be32 pred_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143/*
144 * RFC793 variables by their proper names. This means you can
145 * read the code and the spec side by side (and laugh ...)
146 * See RFC793 and RFC1122. The RFC writes these in capitals.
147 */
Eric Dumazetbdd1f9e2015-04-28 15:28:18 -0700148 u64 bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived
149 * sum(delta(rcv_nxt)), or how many bytes
150 * were acked.
151 */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200152 u32 rcv_nxt; /* What we want to receive next */
Eric Dumazet54287cc2007-02-22 03:20:44 -0800153 u32 copied_seq; /* Head of yet unread data */
154 u32 rcv_wup; /* rcv_nxt on last window update sent */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200155 u32 snd_nxt; /* Next sequence we send */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
Eric Dumazet0df48c22015-04-28 15:28:17 -0700157 u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked
158 * sum(delta(snd_una)), or how many bytes
159 * were acked.
160 */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200161 u32 snd_una; /* First byte we want an ack for */
162 u32 snd_sml; /* Last byte of the most recently transmitted small packet */
163 u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
164 u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
Neal Cardwellf2b2c582015-02-06 16:04:40 -0500165 u32 last_oow_ack_time; /* timestamp of last out-of-window ACK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
Andrey Vaginceaa1fe2013-02-11 05:50:17 +0000167 u32 tsoffset; /* timestamp offset */
168
Eric Dumazet46d3cea2012-07-11 05:50:31 +0000169 struct list_head tsq_node; /* anchor in tsq_tasklet.head list */
170 unsigned long tsq_flags;
171
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 /* Data for direct copy to user */
173 struct {
174 struct sk_buff_head prequeue;
175 struct task_struct *task;
Al Virof4362a22014-11-24 13:26:06 -0500176 struct msghdr *msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 int memory;
178 int len;
179 } ucopy;
180
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200181 u32 snd_wl1; /* Sequence for window update */
182 u32 snd_wnd; /* The window we expect to receive */
183 u32 max_window; /* Maximal window ever seen from peer */
184 u32 mss_cache; /* Cached effective mss, not including SACKS */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200186 u32 window_clamp; /* Maximal window to advertise */
187 u32 rcv_ssthresh; /* Current window clamp */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700189 u16 advmss; /* Advertised MSS */
Yuchung Cheng9b441902013-03-20 13:32:58 +0000190 u8 unused;
Andreas Petlund36e31b0a2010-02-18 02:47:01 +0000191 u8 nonagle : 4,/* Disable Nagle algorithm? */
192 thin_lto : 1,/* Use linear timeouts for thin streams */
Andreas Petlund7e380172010-02-18 04:48:19 +0000193 thin_dupack : 1,/* Fast retransmit on first dupack */
Yuchung Chenge33099f2013-03-20 13:33:00 +0000194 repair : 1,
195 frto : 1;/* F-RTO (RFC5682) activated in CA_Loss */
Pavel Emelyanovee995282012-04-19 03:40:39 +0000196 u8 repair_queue;
Yuchung Cheng750ea2b2012-05-02 13:30:04 +0000197 u8 do_early_retrans:1,/* Enable RFC5827 early-retransmit */
Yuchung Cheng67da22d2012-07-19 06:43:11 +0000198 syn_data:1, /* SYN includes data */
Yuchung Cheng6f736012012-10-19 15:14:44 +0000199 syn_fastopen:1, /* SYN includes Fast Open option */
Daniel Lee2646c832015-04-06 14:37:27 -0700200 syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */
Neal Cardwellca8a2262014-05-22 10:41:08 -0400201 syn_data_acked:1,/* data in SYN is acked by SYN-ACK */
202 is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */
Nandita Dukkipati9b717a82013-03-11 10:00:44 +0000203 u32 tlp_high_seq; /* snd_nxt at the time of TLP retransmit. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
205/* RTT measurement */
Eric Dumazet740b0f12014-02-26 14:02:48 -0800206 u32 srtt_us; /* smoothed round trip time << 3 in usecs */
207 u32 mdev_us; /* medium deviation */
208 u32 mdev_max_us; /* maximal mdev for the last rtt period */
209 u32 rttvar_us; /* smoothed mdev_max */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200210 u32 rtt_seq; /* sequence number to update rttvar */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200212 u32 packets_out; /* Packets which are "in flight" */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200213 u32 retrans_out; /* Retransmitted packets out */
Neal Cardwellca8a2262014-05-22 10:41:08 -0400214 u32 max_packets_out; /* max packets_out in last window */
215 u32 max_packets_seq; /* right edge of max_packets_out flight */
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700216
217 u16 urg_data; /* Saved octet of OOB data and control flags */
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700218 u8 ecn_flags; /* ECN status bits. */
Eric Dumazetdca145f2014-10-27 21:45:24 -0700219 u8 keepalive_probes; /* num of allowed keep alive probes */
220 u32 reordering; /* Packet reordering metric. */
Ilpo Järvinen33f5f572008-10-07 14:43:06 -0700221 u32 snd_up; /* Urgent pointer */
222
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223/*
224 * Options received (usually on last packet, some only on SYN packets).
225 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 struct tcp_options_received rx_opt;
227
228/*
229 * Slow start and congestion control (see also Nagle, and Karn & Partridge)
230 */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200231 u32 snd_ssthresh; /* Slow start size threshold */
232 u32 snd_cwnd; /* Sending congestion window */
Ilpo Järvinenf78a1b32007-10-15 12:59:43 -0700233 u32 snd_cwnd_cnt; /* Linear increase counter */
David S. Millere0ef57c2007-02-22 22:52:59 -0800234 u32 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200235 u32 snd_cwnd_used;
236 u32 snd_cwnd_stamp;
Nandita Dukkipatia262f0c2011-08-21 20:21:57 +0000237 u32 prior_cwnd; /* Congestion window at start of Recovery. */
238 u32 prr_delivered; /* Number of newly delivered packets to
239 * receiver in Recovery. */
240 u32 prr_out; /* Total number of pkts sent during Recovery. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200242 u32 rcv_wnd; /* Current receiver window */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200243 u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
Eric Dumazetc9bee3b72013-07-22 20:27:07 -0700244 u32 notsent_lowat; /* TCP_NOTSENT_LOWAT */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200245 u32 pushed_seq; /* Last pushed seq, required to talk to windows */
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700246 u32 lost_out; /* Lost packets */
247 u32 sacked_out; /* SACK'd packets */
248 u32 fackets_out; /* FACK'd packets */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700250 /* from STCP, retrans queue hinting */
251 struct sk_buff* lost_skb_hint;
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700252 struct sk_buff *retransmit_skb_hint;
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700253
Eric Dumazet996b1752014-01-06 09:36:12 -0800254 /* OOO segments go in this list. Note that socket lock must be held,
255 * as we do not use sk_buff_head lock.
256 */
257 struct sk_buff_head out_of_order_queue;
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700258
Kyle McMartinc0a788c2012-05-07 15:33:04 -0400259 /* SACKs data, these 2 need to be together (see tcp_options_write) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
261 struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
262
Ilpo Järvinenfd6dad62007-11-15 19:49:47 -0800263 struct tcp_sack_block recv_sack_cache[4];
Stephen Hemminger6a438bb2005-11-10 17:14:59 -0800264
Neal Cardwellecb97192012-02-27 17:52:52 -0500265 struct sk_buff *highest_sack; /* skb just after the highest
266 * skb with SACKed bit set
Ilpo Järvinena47e5a92007-11-15 19:41:46 -0800267 * (validity guaranteed only if
268 * sacked_out > 0)
269 */
Ilpo Järvinend738cd82007-03-24 21:03:23 -0700270
Stephen Hemminger6a438bb2005-11-10 17:14:59 -0800271 int lost_cnt_hint;
Ilpo Järvinen006f5822008-09-20 21:20:20 -0700272 u32 retransmit_high; /* L-bits may be on up to this seqno */
Stephen Hemminger6a438bb2005-11-10 17:14:59 -0800273
Ilpo Järvinenb08d6cb2007-10-11 17:36:13 -0700274 u32 lost_retrans_low; /* Sent seq after any rxmit (lowest) */
275
Ilpo Järvinen4b7494402008-05-21 17:40:05 -0700276 u32 prior_ssthresh; /* ssthresh saved at recovery start */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200277 u32 high_seq; /* snd_nxt at onset of congestion */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200279 u32 retrans_stamp; /* Timestamp of the last retransmit,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 * also used in SYN-SENT to remember stamp of
281 * the first SYN. */
Yuchung Cheng989e04c2014-08-22 14:15:22 -0700282 u32 undo_marker; /* snd_una upon a new recovery episode. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 int undo_retrans; /* number of undoable retransmissions. */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200284 u32 total_retrans; /* Total retransmits for entire connection */
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700285
286 u32 urg_seq; /* Seq of received urgent pointer */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 unsigned int keepalive_time; /* time before keep alive takes place */
288 unsigned int keepalive_intvl; /* time interval between keep alive probes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289
Florian Westphala0f82f62009-04-19 09:43:48 +0000290 int linger2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
292/* Receiver side RTT estimation */
293 struct {
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200294 u32 rtt;
295 u32 seq;
296 u32 time;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 } rcv_rtt_est;
298
299/* Receiver queue space */
300 struct {
301 int space;
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200302 u32 seq;
303 u32 time;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 } rcvq_space;
John Heffner0e7b1362006-03-20 21:32:58 -0800305
306/* TCP-specific MTU probe information. */
307 struct {
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200308 u32 probe_seq_start;
309 u32 probe_seq_end;
John Heffner0e7b1362006-03-20 21:32:58 -0800310 } mtu_probe;
Eric Dumazet563d34d2012-07-23 09:48:52 +0200311 u32 mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG
312 * while socket was owned by user.
313 */
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800314
315#ifdef CONFIG_TCP_MD5SIG
316/* TCP AF-Specific parts; only used by MD5 Signature support so far */
Stephen Hemmingerb2e4b3d2009-09-01 19:25:03 +0000317 const struct tcp_sock_af_ops *af_specific;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800318
Stephen Hemmingerb2e4b3d2009-09-01 19:25:03 +0000319/* TCP MD5 Signature Option information */
Eric Dumazeta8afca02012-01-31 18:45:40 +0000320 struct tcp_md5sig_info __rcu *md5sig_info;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800321#endif
William Allen Simpson435cf552009-12-02 18:17:05 +0000322
Jerry Chu10467162012-08-31 12:29:11 +0000323/* TCP fastopen related information */
324 struct tcp_fastopen_request *fastopen_req;
325 /* fastopen_rsk points to request_sock that resulted in this big
326 * socket. Used to retransmit SYNACKs etc.
327 */
328 struct request_sock *fastopen_rsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329};
330
Eric Dumazet46d3cea2012-07-11 05:50:31 +0000331enum tsq_flags {
332 TSQ_THROTTLED,
333 TSQ_QUEUED,
Eric Dumazet6f458df2012-07-20 05:45:50 +0000334 TCP_TSQ_DEFERRED, /* tcp_tasklet_func() found socket was owned */
335 TCP_WRITE_TIMER_DEFERRED, /* tcp_write_timer() found socket was owned */
336 TCP_DELACK_TIMER_DEFERRED, /* tcp_delack_timer() found socket was owned */
Eric Dumazet563d34d2012-07-23 09:48:52 +0200337 TCP_MTU_REDUCED_DEFERRED, /* tcp_v{4|6}_err() could not call
338 * tcp_v{4|6}_mtu_reduced()
339 */
Eric Dumazet46d3cea2012-07-11 05:50:31 +0000340};
341
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342static inline struct tcp_sock *tcp_sk(const struct sock *sk)
343{
344 return (struct tcp_sock *)sk;
345}
346
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700347struct tcp_timewait_sock {
348 struct inet_timewait_sock tw_sk;
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200349 u32 tw_rcv_nxt;
350 u32 tw_snd_nxt;
351 u32 tw_rcv_wnd;
Andrey Vaginceaa1fe2013-02-11 05:50:17 +0000352 u32 tw_ts_offset;
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200353 u32 tw_ts_recent;
Neal Cardwell4fb17a62015-02-06 16:04:41 -0500354
355 /* The time we sent the last out-of-window ACK: */
356 u32 tw_last_oow_ack_time;
357
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700358 long tw_ts_recent_stamp;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800359#ifdef CONFIG_TCP_MD5SIG
David S. Miller23978492012-06-09 14:56:12 -0700360 struct tcp_md5sig_key *tw_md5_key;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800361#endif
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700362};
363
364static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
365{
366 return (struct tcp_timewait_sock *)sk;
367}
368
Jerry Chu10467162012-08-31 12:29:11 +0000369static inline bool tcp_passive_fastopen(const struct sock *sk)
370{
371 return (sk->sk_state == TCP_SYN_RECV &&
372 tcp_sk(sk)->fastopen_rsk != NULL);
373}
374
Christoph Paaschbb68b642012-09-18 14:19:23 +0000375extern void tcp_sock_destruct(struct sock *sk);
376
Jerry Chu10467162012-08-31 12:29:11 +0000377static inline int fastopen_init_queue(struct sock *sk, int backlog)
378{
379 struct request_sock_queue *queue =
380 &inet_csk(sk)->icsk_accept_queue;
381
382 if (queue->fastopenq == NULL) {
383 queue->fastopenq = kzalloc(
384 sizeof(struct fastopen_queue),
385 sk->sk_allocation);
386 if (queue->fastopenq == NULL)
387 return -ENOMEM;
Christoph Paaschbb68b642012-09-18 14:19:23 +0000388
389 sk->sk_destruct = tcp_sock_destruct;
Jerry Chu10467162012-08-31 12:29:11 +0000390 spin_lock_init(&queue->fastopenq->lock);
391 }
392 queue->fastopenq->max_qlen = backlog;
393 return 0;
394}
395
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396#endif /* _LINUX_TCP_H */