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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
20#include <linux/types.h>
21#include <asm/byteorder.h>
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -080022#include <linux/socket.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
24struct tcphdr {
Al Viro46a97322006-09-27 18:31:51 -070025 __be16 source;
26 __be16 dest;
27 __be32 seq;
28 __be32 ack_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#if defined(__LITTLE_ENDIAN_BITFIELD)
30 __u16 res1:4,
31 doff:4,
32 fin:1,
33 syn:1,
34 rst:1,
35 psh:1,
36 ack:1,
37 urg:1,
38 ece:1,
39 cwr:1;
40#elif defined(__BIG_ENDIAN_BITFIELD)
41 __u16 doff:4,
42 res1:4,
43 cwr:1,
44 ece:1,
45 urg:1,
46 ack:1,
47 psh:1,
48 rst:1,
49 syn:1,
50 fin:1;
51#else
52#error "Adjust your <asm/byteorder.h> defines"
53#endif
Al Viro46a97322006-09-27 18:31:51 -070054 __be16 window;
Al Viro9981a0e2006-11-14 21:24:30 -080055 __sum16 check;
Al Viro46a97322006-09-27 18:31:51 -070056 __be16 urg_ptr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057};
58
Linus Torvalds1da177e2005-04-16 15:20:36 -070059/*
60 * The union cast uses a gcc extension to avoid aliasing problems
61 * (union is compatible to any of its members)
62 * This means this part of the code is -fstrict-aliasing safe now.
63 */
64union tcp_word_hdr {
65 struct tcphdr hdr;
Al Viro46a97322006-09-27 18:31:51 -070066 __be32 words[5];
Linus Torvalds1da177e2005-04-16 15:20:36 -070067};
68
69#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
70
71enum {
Harvey Harrisonf3a7c662009-02-14 22:58:35 -080072 TCP_FLAG_CWR = __cpu_to_be32(0x00800000),
73 TCP_FLAG_ECE = __cpu_to_be32(0x00400000),
74 TCP_FLAG_URG = __cpu_to_be32(0x00200000),
75 TCP_FLAG_ACK = __cpu_to_be32(0x00100000),
76 TCP_FLAG_PSH = __cpu_to_be32(0x00080000),
77 TCP_FLAG_RST = __cpu_to_be32(0x00040000),
78 TCP_FLAG_SYN = __cpu_to_be32(0x00020000),
79 TCP_FLAG_FIN = __cpu_to_be32(0x00010000),
80 TCP_RESERVED_BITS = __cpu_to_be32(0x0F000000),
81 TCP_DATA_OFFSET = __cpu_to_be32(0xF0000000)
Linus Torvalds1da177e2005-04-16 15:20:36 -070082};
83
William Allen Simpsonbee7ca92009-11-10 09:51:18 +000084/*
85 * TCP general constants
86 */
87#define TCP_MSS_DEFAULT 536U /* IPv4 (RFC1122, RFC2581) */
88#define TCP_MSS_DESIRED 1220U /* IPv6 (tunneled), EDNS0 (RFC3226) */
89
Linus Torvalds1da177e2005-04-16 15:20:36 -070090/* TCP socket options */
91#define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */
92#define TCP_MAXSEG 2 /* Limit MSS */
93#define TCP_CORK 3 /* Never send partially complete segments */
94#define TCP_KEEPIDLE 4 /* Start keeplives after this period */
95#define TCP_KEEPINTVL 5 /* Interval between keepalives */
96#define TCP_KEEPCNT 6 /* Number of keepalives before death */
97#define TCP_SYNCNT 7 /* Number of SYN retransmits */
98#define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */
99#define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */
100#define TCP_WINDOW_CLAMP 10 /* Bound advertised window */
101#define TCP_INFO 11 /* Information about this connection. */
102#define TCP_QUICKACK 12 /* Block/reenable quick acks */
Stephen Hemminger5f8ef482005-06-23 20:37:36 -0700103#define TCP_CONGESTION 13 /* Congestion control algorithm */
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800104#define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */
William Allen Simpson519855c2009-12-02 18:14:19 +0000105#define TCP_COOKIE_TRANSACTIONS 15 /* TCP Cookie Transactions */
Andreas Petlund36e31b0a2010-02-18 02:47:01 +0000106#define TCP_THIN_LINEAR_TIMEOUTS 16 /* Use linear timeouts for thin streams*/
Andreas Petlund7e380172010-02-18 04:48:19 +0000107#define TCP_THIN_DUPACK 17 /* Fast retrans. after 1 dupack */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
William Allen Simpson519855c2009-12-02 18:14:19 +0000109/* for TCP_INFO socket option */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110#define TCPI_OPT_TIMESTAMPS 1
111#define TCPI_OPT_SACK 2
112#define TCPI_OPT_WSCALE 4
113#define TCPI_OPT_ECN 8
114
Eric Dumazetd94d9fe2009-11-04 09:50:58 -0800115enum tcp_ca_state {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 TCP_CA_Open = 0,
117#define TCPF_CA_Open (1<<TCP_CA_Open)
118 TCP_CA_Disorder = 1,
119#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
120 TCP_CA_CWR = 2,
121#define TCPF_CA_CWR (1<<TCP_CA_CWR)
122 TCP_CA_Recovery = 3,
123#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
124 TCP_CA_Loss = 4
125#define TCPF_CA_Loss (1<<TCP_CA_Loss)
126};
127
Eric Dumazetd94d9fe2009-11-04 09:50:58 -0800128struct tcp_info {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 __u8 tcpi_state;
130 __u8 tcpi_ca_state;
131 __u8 tcpi_retransmits;
132 __u8 tcpi_probes;
133 __u8 tcpi_backoff;
134 __u8 tcpi_options;
135 __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
136
137 __u32 tcpi_rto;
138 __u32 tcpi_ato;
139 __u32 tcpi_snd_mss;
140 __u32 tcpi_rcv_mss;
141
142 __u32 tcpi_unacked;
143 __u32 tcpi_sacked;
144 __u32 tcpi_lost;
145 __u32 tcpi_retrans;
146 __u32 tcpi_fackets;
147
148 /* Times. */
149 __u32 tcpi_last_data_sent;
150 __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
151 __u32 tcpi_last_data_recv;
152 __u32 tcpi_last_ack_recv;
153
154 /* Metrics. */
155 __u32 tcpi_pmtu;
156 __u32 tcpi_rcv_ssthresh;
157 __u32 tcpi_rtt;
158 __u32 tcpi_rttvar;
159 __u32 tcpi_snd_ssthresh;
160 __u32 tcpi_snd_cwnd;
161 __u32 tcpi_advmss;
162 __u32 tcpi_reordering;
163
164 __u32 tcpi_rcv_rtt;
165 __u32 tcpi_rcv_space;
166
167 __u32 tcpi_total_retrans;
168};
169
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800170/* for TCP_MD5SIG socket option */
171#define TCP_MD5SIG_MAXKEYLEN 80
172
173struct tcp_md5sig {
174 struct __kernel_sockaddr_storage tcpm_addr; /* address associated */
175 __u16 __tcpm_pad1; /* zero */
176 __u16 tcpm_keylen; /* key length */
177 __u32 __tcpm_pad2; /* zero */
178 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
179};
180
William Allen Simpson519855c2009-12-02 18:14:19 +0000181/* for TCP_COOKIE_TRANSACTIONS (TCPCT) socket option */
182#define TCP_COOKIE_MIN 8 /* 64-bits */
183#define TCP_COOKIE_MAX 16 /* 128-bits */
184#define TCP_COOKIE_PAIR_SIZE (2*TCP_COOKIE_MAX)
185
186/* Flags for both getsockopt and setsockopt */
187#define TCP_COOKIE_IN_ALWAYS (1 << 0) /* Discard SYN without cookie */
188#define TCP_COOKIE_OUT_NEVER (1 << 1) /* Prohibit outgoing cookies,
189 * supercedes everything. */
190
191/* Flags for getsockopt */
192#define TCP_S_DATA_IN (1 << 2) /* Was data received? */
193#define TCP_S_DATA_OUT (1 << 3) /* Was data sent? */
194
195/* TCP_COOKIE_TRANSACTIONS data */
196struct tcp_cookie_transactions {
197 __u16 tcpct_flags; /* see above */
198 __u8 __tcpct_pad1; /* zero */
199 __u8 tcpct_cookie_desired; /* bytes */
200 __u16 tcpct_s_data_desired; /* bytes of variable data */
201 __u16 tcpct_used; /* bytes in value */
202 __u8 tcpct_value[TCP_MSS_DEFAULT];
203};
204
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205#ifdef __KERNEL__
206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207#include <linux/skbuff.h>
David Woodhousec8a553ad2006-06-22 14:28:09 -0700208#include <linux/dmaengine.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209#include <net/sock.h>
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700210#include <net/inet_connection_sock.h>
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700211#include <net/inet_timewait_sock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700213static inline struct tcphdr *tcp_hdr(const struct sk_buff *skb)
214{
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -0700215 return (struct tcphdr *)skb_transport_header(skb);
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700216}
217
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -0700218static inline unsigned int tcp_hdrlen(const struct sk_buff *skb)
219{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700220 return tcp_hdr(skb)->doff * 4;
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -0700221}
222
223static inline unsigned int tcp_optlen(const struct sk_buff *skb)
224{
Arnaldo Carvalho de Meloaa8223c2007-04-10 21:04:22 -0700225 return (tcp_hdr(skb)->doff - 5) * 4;
Arnaldo Carvalho de Meloab6a5bb2007-03-18 17:43:48 -0700226}
227
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228/* This defines a selective acknowledgement block. */
Al Viro269bd272006-09-27 18:32:28 -0700229struct tcp_sack_block_wire {
230 __be32 start_seq;
231 __be32 end_seq;
232};
233
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234struct tcp_sack_block {
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200235 u32 start_seq;
236 u32 end_seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237};
238
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239struct tcp_options_received {
240/* PAWS/RTTM data */
241 long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200242 u32 ts_recent; /* Time stamp to echo next */
243 u32 rcv_tsval; /* Time stamp value */
244 u32 rcv_tsecr; /* Time stamp echo reply */
245 u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
247 dsack : 1, /* D-SACK is scheduled */
248 wscale_ok : 1, /* Wscale seen on SYN packet */
249 sack_ok : 4, /* SACK seen on SYN packet */
250 snd_wscale : 4, /* Window scaling received from sender */
251 rcv_wscale : 4; /* Window scaling to send to receiver */
William Allen Simpson435cf552009-12-02 18:17:05 +0000252 u8 cookie_plus:6, /* bytes in authenticator/cookie option */
253 cookie_out_never:1,
254 cookie_in_always:1;
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200255 u8 num_sacks; /* Number of SACK blocks */
William Allen Simpson435cf552009-12-02 18:17:05 +0000256 u16 user_mss; /* mss requested by user in ioctl */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200257 u16 mss_clamp; /* Maximal mss, negotiated at connection setup */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258};
259
William Allen Simpson519855c2009-12-02 18:14:19 +0000260static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
261{
William Allen Simpson435cf552009-12-02 18:17:05 +0000262 rx_opt->tstamp_ok = rx_opt->sack_ok = 0;
263 rx_opt->wscale_ok = rx_opt->snd_wscale = 0;
264 rx_opt->cookie_plus = 0;
William Allen Simpson519855c2009-12-02 18:14:19 +0000265}
266
Adam Langley4389dde2008-07-19 00:07:02 -0700267/* This is the max number of SACKS that we'll generate and process. It's safe
William Allen Simpson435cf552009-12-02 18:17:05 +0000268 * to increase this, although since:
Adam Langley4389dde2008-07-19 00:07:02 -0700269 * size = TCPOLEN_SACK_BASE_ALIGNED (4) + n * TCPOLEN_SACK_PERBLOCK (8)
270 * only four options will fit in a standard TCP header */
271#define TCP_NUM_SACKS 4
272
William Allen Simpson435cf552009-12-02 18:17:05 +0000273struct tcp_cookie_values;
274struct tcp_request_sock_ops;
275
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700276struct tcp_request_sock {
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800277 struct inet_request_sock req;
278#ifdef CONFIG_TCP_MD5SIG
279 /* Only used by TCP MD5 Signature so far. */
Stephen Hemmingerb2e4b3d2009-09-01 19:25:03 +0000280 const struct tcp_request_sock_ops *af_specific;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800281#endif
William Allen Simpson435cf552009-12-02 18:17:05 +0000282 u32 rcv_isn;
283 u32 snt_isn;
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700284};
285
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700286static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700287{
288 return (struct tcp_request_sock *)req;
289}
290
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291struct tcp_sock {
Arnaldo Carvalho de Melo463c84b2005-08-09 20:10:42 -0700292 /* inet_connection_sock has to be the first member of tcp_sock */
293 struct inet_connection_sock inet_conn;
Arnaldo Carvalho de Melo2ff52f22006-11-28 00:48:32 -0200294 u16 tcp_header_len; /* Bytes of tcp header to send */
Ilpo Järvinen2a3a0412009-03-14 22:45:16 +0000295 u16 xmit_size_goal_segs; /* Goal for segmenting output packets */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
297/*
298 * Header prediction flags
299 * 0x5?10 << 16 + snd_wnd in net byte order
300 */
Al Virodddc93c2006-09-27 18:32:46 -0700301 __be32 pred_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302
303/*
304 * RFC793 variables by their proper names. This means you can
305 * read the code and the spec side by side (and laugh ...)
306 * See RFC793 and RFC1122. The RFC writes these in capitals.
307 */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200308 u32 rcv_nxt; /* What we want to receive next */
Eric Dumazet54287cc2007-02-22 03:20:44 -0800309 u32 copied_seq; /* Head of yet unread data */
310 u32 rcv_wup; /* rcv_nxt on last window update sent */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200311 u32 snd_nxt; /* Next sequence we send */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200313 u32 snd_una; /* First byte we want an ack for */
314 u32 snd_sml; /* Last byte of the most recently transmitted small packet */
315 u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
316 u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317
318 /* Data for direct copy to user */
319 struct {
320 struct sk_buff_head prequeue;
321 struct task_struct *task;
322 struct iovec *iov;
323 int memory;
324 int len;
Chris Leech97fc2f02006-05-23 17:55:33 -0700325#ifdef CONFIG_NET_DMA
326 /* members for async copy */
327 struct dma_chan *dma_chan;
328 int wakeup;
329 struct dma_pinned_list *pinned_list;
330 dma_cookie_t dma_cookie;
331#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 } ucopy;
333
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200334 u32 snd_wl1; /* Sequence for window update */
335 u32 snd_wnd; /* The window we expect to receive */
336 u32 max_window; /* Maximal window ever seen from peer */
337 u32 mss_cache; /* Cached effective mss, not including SACKS */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200339 u32 window_clamp; /* Maximal window to advertise */
340 u32 rcv_ssthresh; /* Current window clamp */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200342 u32 frto_highmark; /* snd_nxt when RTO occurred */
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700343 u16 advmss; /* Advertised MSS */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200344 u8 frto_counter; /* Number of new acks after RTO */
Andreas Petlund36e31b0a2010-02-18 02:47:01 +0000345 u8 nonagle : 4,/* Disable Nagle algorithm? */
346 thin_lto : 1,/* Use linear timeouts for thin streams */
Andreas Petlund7e380172010-02-18 04:48:19 +0000347 thin_dupack : 1,/* Fast retransmit on first dupack */
348 unused : 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
350/* RTT measurement */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200351 u32 srtt; /* smoothed round trip time << 3 */
352 u32 mdev; /* medium deviation */
353 u32 mdev_max; /* maximal mdev for the last rtt period */
354 u32 rttvar; /* smoothed mdev_max */
355 u32 rtt_seq; /* sequence number to update rttvar */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200357 u32 packets_out; /* Packets which are "in flight" */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200358 u32 retrans_out; /* Retransmitted packets out */
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700359
360 u16 urg_data; /* Saved octet of OOB data and control flags */
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700361 u8 ecn_flags; /* ECN status bits. */
Ilpo Järvinen33f5f572008-10-07 14:43:06 -0700362 u8 reordering; /* Packet reordering metric. */
363 u32 snd_up; /* Urgent pointer */
364
365 u8 keepalive_probes; /* num of allowed keep alive probes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366/*
367 * Options received (usually on last packet, some only on SYN packets).
368 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 struct tcp_options_received rx_opt;
370
371/*
372 * Slow start and congestion control (see also Nagle, and Karn & Partridge)
373 */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200374 u32 snd_ssthresh; /* Slow start size threshold */
375 u32 snd_cwnd; /* Sending congestion window */
Ilpo Järvinenf78a1b32007-10-15 12:59:43 -0700376 u32 snd_cwnd_cnt; /* Linear increase counter */
David S. Millere0ef57c2007-02-22 22:52:59 -0800377 u32 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200378 u32 snd_cwnd_used;
379 u32 snd_cwnd_stamp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200381 u32 rcv_wnd; /* Current receiver window */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200382 u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
383 u32 pushed_seq; /* Last pushed seq, required to talk to windows */
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700384 u32 lost_out; /* Lost packets */
385 u32 sacked_out; /* SACK'd packets */
386 u32 fackets_out; /* FACK'd packets */
387 u32 tso_deferred;
388 u32 bytes_acked; /* Appropriate Byte Counting - RFC3465 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700390 /* from STCP, retrans queue hinting */
391 struct sk_buff* lost_skb_hint;
392 struct sk_buff *scoreboard_skb_hint;
393 struct sk_buff *retransmit_skb_hint;
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700394
395 struct sk_buff_head out_of_order_queue; /* Out of order segments go here */
396
397 /* SACKs data, these 2 need to be together (see tcp_build_and_update_options) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
399 struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
400
Ilpo Järvinenfd6dad62007-11-15 19:49:47 -0800401 struct tcp_sack_block recv_sack_cache[4];
Stephen Hemminger6a438bb2005-11-10 17:14:59 -0800402
Ilpo Järvinena47e5a92007-11-15 19:41:46 -0800403 struct sk_buff *highest_sack; /* highest skb with SACK received
404 * (validity guaranteed only if
405 * sacked_out > 0)
406 */
Ilpo Järvinend738cd82007-03-24 21:03:23 -0700407
Stephen Hemminger6a438bb2005-11-10 17:14:59 -0800408 int lost_cnt_hint;
Ilpo Järvinen006f5822008-09-20 21:20:20 -0700409 u32 retransmit_high; /* L-bits may be on up to this seqno */
Stephen Hemminger6a438bb2005-11-10 17:14:59 -0800410
Ilpo Järvinenb08d6cb2007-10-11 17:36:13 -0700411 u32 lost_retrans_low; /* Sent seq after any rxmit (lowest) */
412
Ilpo Järvinen4b7494402008-05-21 17:40:05 -0700413 u32 prior_ssthresh; /* ssthresh saved at recovery start */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200414 u32 high_seq; /* snd_nxt at onset of congestion */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200416 u32 retrans_stamp; /* Timestamp of the last retransmit,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 * also used in SYN-SENT to remember stamp of
418 * the first SYN. */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200419 u32 undo_marker; /* tracking retrans started here. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 int undo_retrans; /* number of undoable retransmissions. */
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200421 u32 total_retrans; /* Total retransmits for entire connection */
Ilpo Järvinenb79eeeb2008-05-29 03:25:23 -0700422
423 u32 urg_seq; /* Seq of received urgent pointer */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424 unsigned int keepalive_time; /* time before keep alive takes place */
425 unsigned int keepalive_intvl; /* time interval between keep alive probes */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
Florian Westphala0f82f62009-04-19 09:43:48 +0000427 int linger2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428
429/* Receiver side RTT estimation */
430 struct {
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200431 u32 rtt;
432 u32 seq;
433 u32 time;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 } rcv_rtt_est;
435
436/* Receiver queue space */
437 struct {
438 int space;
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200439 u32 seq;
440 u32 time;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 } rcvq_space;
John Heffner0e7b1362006-03-20 21:32:58 -0800442
443/* TCP-specific MTU probe information. */
444 struct {
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200445 u32 probe_seq_start;
446 u32 probe_seq_end;
John Heffner0e7b1362006-03-20 21:32:58 -0800447 } mtu_probe;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800448
449#ifdef CONFIG_TCP_MD5SIG
450/* TCP AF-Specific parts; only used by MD5 Signature support so far */
Stephen Hemmingerb2e4b3d2009-09-01 19:25:03 +0000451 const struct tcp_sock_af_ops *af_specific;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800452
Stephen Hemmingerb2e4b3d2009-09-01 19:25:03 +0000453/* TCP MD5 Signature Option information */
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800454 struct tcp_md5sig_info *md5sig_info;
455#endif
William Allen Simpson435cf552009-12-02 18:17:05 +0000456
457 /* When the cookie options are generated and exchanged, then this
458 * object holds a reference to them (cookie_values->kref). Also
459 * contains related tcp_cookie_transactions fields.
460 */
461 struct tcp_cookie_values *cookie_values;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462};
463
464static inline struct tcp_sock *tcp_sk(const struct sock *sk)
465{
466 return (struct tcp_sock *)sk;
467}
468
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700469struct tcp_timewait_sock {
470 struct inet_timewait_sock tw_sk;
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200471 u32 tw_rcv_nxt;
472 u32 tw_snd_nxt;
473 u32 tw_rcv_wnd;
474 u32 tw_ts_recent;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700475 long tw_ts_recent_stamp;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800476#ifdef CONFIG_TCP_MD5SIG
Arnaldo Carvalho de Melo3a137d22006-11-28 01:12:38 -0200477 u16 tw_md5_keylen;
478 u8 tw_md5_key[TCP_MD5SIG_MAXKEYLEN];
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800479#endif
William Allen Simpson435cf552009-12-02 18:17:05 +0000480 /* Few sockets in timewait have cookies; in that case, then this
481 * object holds a reference to them (tw_cookie_values->kref).
482 */
483 struct tcp_cookie_values *tw_cookie_values;
Arnaldo Carvalho de Melo8feaf0c02005-08-09 20:09:30 -0700484};
485
486static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
487{
488 return (struct tcp_timewait_sock *)sk;
489}
490
William Allen Simpson519855c2009-12-02 18:14:19 +0000491#endif /* __KERNEL__ */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492
493#endif /* _LINUX_TCP_H */