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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>
22
23struct tcphdr {
24 __u16 source;
25 __u16 dest;
26 __u32 seq;
27 __u32 ack_seq;
28#if defined(__LITTLE_ENDIAN_BITFIELD)
29 __u16 res1:4,
30 doff:4,
31 fin:1,
32 syn:1,
33 rst:1,
34 psh:1,
35 ack:1,
36 urg:1,
37 ece:1,
38 cwr:1;
39#elif defined(__BIG_ENDIAN_BITFIELD)
40 __u16 doff:4,
41 res1:4,
42 cwr:1,
43 ece:1,
44 urg:1,
45 ack:1,
46 psh:1,
47 rst:1,
48 syn:1,
49 fin:1;
50#else
51#error "Adjust your <asm/byteorder.h> defines"
52#endif
53 __u16 window;
54 __u16 check;
55 __u16 urg_ptr;
56};
57
58
59enum {
60 TCP_ESTABLISHED = 1,
61 TCP_SYN_SENT,
62 TCP_SYN_RECV,
63 TCP_FIN_WAIT1,
64 TCP_FIN_WAIT2,
65 TCP_TIME_WAIT,
66 TCP_CLOSE,
67 TCP_CLOSE_WAIT,
68 TCP_LAST_ACK,
69 TCP_LISTEN,
70 TCP_CLOSING, /* now a valid state */
71
72 TCP_MAX_STATES /* Leave at the end! */
73};
74
75#define TCP_STATE_MASK 0xF
76#define TCP_ACTION_FIN (1 << 7)
77
78enum {
79 TCPF_ESTABLISHED = (1 << 1),
80 TCPF_SYN_SENT = (1 << 2),
81 TCPF_SYN_RECV = (1 << 3),
82 TCPF_FIN_WAIT1 = (1 << 4),
83 TCPF_FIN_WAIT2 = (1 << 5),
84 TCPF_TIME_WAIT = (1 << 6),
85 TCPF_CLOSE = (1 << 7),
86 TCPF_CLOSE_WAIT = (1 << 8),
87 TCPF_LAST_ACK = (1 << 9),
88 TCPF_LISTEN = (1 << 10),
89 TCPF_CLOSING = (1 << 11)
90};
91
92/*
93 * The union cast uses a gcc extension to avoid aliasing problems
94 * (union is compatible to any of its members)
95 * This means this part of the code is -fstrict-aliasing safe now.
96 */
97union tcp_word_hdr {
98 struct tcphdr hdr;
99 __u32 words[5];
100};
101
102#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
103
104enum {
105 TCP_FLAG_CWR = __constant_htonl(0x00800000),
106 TCP_FLAG_ECE = __constant_htonl(0x00400000),
107 TCP_FLAG_URG = __constant_htonl(0x00200000),
108 TCP_FLAG_ACK = __constant_htonl(0x00100000),
109 TCP_FLAG_PSH = __constant_htonl(0x00080000),
110 TCP_FLAG_RST = __constant_htonl(0x00040000),
111 TCP_FLAG_SYN = __constant_htonl(0x00020000),
112 TCP_FLAG_FIN = __constant_htonl(0x00010000),
113 TCP_RESERVED_BITS = __constant_htonl(0x0F000000),
114 TCP_DATA_OFFSET = __constant_htonl(0xF0000000)
115};
116
117/* TCP socket options */
118#define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */
119#define TCP_MAXSEG 2 /* Limit MSS */
120#define TCP_CORK 3 /* Never send partially complete segments */
121#define TCP_KEEPIDLE 4 /* Start keeplives after this period */
122#define TCP_KEEPINTVL 5 /* Interval between keepalives */
123#define TCP_KEEPCNT 6 /* Number of keepalives before death */
124#define TCP_SYNCNT 7 /* Number of SYN retransmits */
125#define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */
126#define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */
127#define TCP_WINDOW_CLAMP 10 /* Bound advertised window */
128#define TCP_INFO 11 /* Information about this connection. */
129#define TCP_QUICKACK 12 /* Block/reenable quick acks */
130
131#define TCPI_OPT_TIMESTAMPS 1
132#define TCPI_OPT_SACK 2
133#define TCPI_OPT_WSCALE 4
134#define TCPI_OPT_ECN 8
135
136enum tcp_ca_state
137{
138 TCP_CA_Open = 0,
139#define TCPF_CA_Open (1<<TCP_CA_Open)
140 TCP_CA_Disorder = 1,
141#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
142 TCP_CA_CWR = 2,
143#define TCPF_CA_CWR (1<<TCP_CA_CWR)
144 TCP_CA_Recovery = 3,
145#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
146 TCP_CA_Loss = 4
147#define TCPF_CA_Loss (1<<TCP_CA_Loss)
148};
149
150struct tcp_info
151{
152 __u8 tcpi_state;
153 __u8 tcpi_ca_state;
154 __u8 tcpi_retransmits;
155 __u8 tcpi_probes;
156 __u8 tcpi_backoff;
157 __u8 tcpi_options;
158 __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
159
160 __u32 tcpi_rto;
161 __u32 tcpi_ato;
162 __u32 tcpi_snd_mss;
163 __u32 tcpi_rcv_mss;
164
165 __u32 tcpi_unacked;
166 __u32 tcpi_sacked;
167 __u32 tcpi_lost;
168 __u32 tcpi_retrans;
169 __u32 tcpi_fackets;
170
171 /* Times. */
172 __u32 tcpi_last_data_sent;
173 __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
174 __u32 tcpi_last_data_recv;
175 __u32 tcpi_last_ack_recv;
176
177 /* Metrics. */
178 __u32 tcpi_pmtu;
179 __u32 tcpi_rcv_ssthresh;
180 __u32 tcpi_rtt;
181 __u32 tcpi_rttvar;
182 __u32 tcpi_snd_ssthresh;
183 __u32 tcpi_snd_cwnd;
184 __u32 tcpi_advmss;
185 __u32 tcpi_reordering;
186
187 __u32 tcpi_rcv_rtt;
188 __u32 tcpi_rcv_space;
189
190 __u32 tcpi_total_retrans;
191};
192
193#ifdef __KERNEL__
194
195#include <linux/config.h>
196#include <linux/skbuff.h>
197#include <linux/ip.h>
198#include <net/sock.h>
199
200/* This defines a selective acknowledgement block. */
201struct tcp_sack_block {
202 __u32 start_seq;
203 __u32 end_seq;
204};
205
206enum tcp_congestion_algo {
207 TCP_RENO=0,
208 TCP_VEGAS,
209 TCP_WESTWOOD,
210 TCP_BIC,
211};
212
213struct tcp_options_received {
214/* PAWS/RTTM data */
215 long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
216 __u32 ts_recent; /* Time stamp to echo next */
217 __u32 rcv_tsval; /* Time stamp value */
218 __u32 rcv_tsecr; /* Time stamp echo reply */
219 __u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */
220 tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
221 dsack : 1, /* D-SACK is scheduled */
222 wscale_ok : 1, /* Wscale seen on SYN packet */
223 sack_ok : 4, /* SACK seen on SYN packet */
224 snd_wscale : 4, /* Window scaling received from sender */
225 rcv_wscale : 4; /* Window scaling to send to receiver */
226/* SACKs data */
227 __u8 eff_sacks; /* Size of SACK array to send with next packet */
228 __u8 num_sacks; /* Number of SACK blocks */
229 __u16 user_mss; /* mss requested by user in ioctl */
230 __u16 mss_clamp; /* Maximal mss, negotiated at connection setup */
231};
232
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700233struct tcp_request_sock {
234 struct inet_request_sock req;
235 __u32 rcv_isn;
236 __u32 snt_isn;
237};
238
Arnaldo Carvalho de Melo60236fd2005-06-18 22:47:21 -0700239static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
Arnaldo Carvalho de Melo2e6599c2005-06-18 22:46:52 -0700240{
241 return (struct tcp_request_sock *)req;
242}
243
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244struct tcp_sock {
245 /* inet_sock has to be the first member of tcp_sock */
246 struct inet_sock inet;
247 int tcp_header_len; /* Bytes of tcp header to send */
248
249/*
250 * Header prediction flags
251 * 0x5?10 << 16 + snd_wnd in net byte order
252 */
253 __u32 pred_flags;
254
255/*
256 * RFC793 variables by their proper names. This means you can
257 * read the code and the spec side by side (and laugh ...)
258 * See RFC793 and RFC1122. The RFC writes these in capitals.
259 */
260 __u32 rcv_nxt; /* What we want to receive next */
261 __u32 snd_nxt; /* Next sequence we send */
262
263 __u32 snd_una; /* First byte we want an ack for */
264 __u32 snd_sml; /* Last byte of the most recently transmitted small packet */
265 __u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
266 __u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
267 struct tcp_bind_bucket *bind_hash;
268 /* Delayed ACK control data */
269 struct {
270 __u8 pending; /* ACK is pending */
271 __u8 quick; /* Scheduled number of quick acks */
272 __u8 pingpong; /* The session is interactive */
273 __u8 blocked; /* Delayed ACK was blocked by socket lock*/
274 __u32 ato; /* Predicted tick of soft clock */
275 unsigned long timeout; /* Currently scheduled timeout */
276 __u32 lrcvtime; /* timestamp of last received data packet*/
277 __u16 last_seg_size; /* Size of last incoming segment */
278 __u16 rcv_mss; /* MSS used for delayed ACK decisions */
279 } ack;
280
281 /* Data for direct copy to user */
282 struct {
283 struct sk_buff_head prequeue;
284 struct task_struct *task;
285 struct iovec *iov;
286 int memory;
287 int len;
288 } ucopy;
289
290 __u32 snd_wl1; /* Sequence for window update */
291 __u32 snd_wnd; /* The window we expect to receive */
292 __u32 max_window; /* Maximal window ever seen from peer */
293 __u32 pmtu_cookie; /* Last pmtu seen by socket */
294 __u32 mss_cache; /* Cached effective mss, not including SACKS */
295 __u16 mss_cache_std; /* Like mss_cache, but without TSO */
296 __u16 ext_header_len; /* Network protocol overhead (IP/IPv6 options) */
297 __u8 ca_state; /* State of fast-retransmit machine */
298 __u8 retransmits; /* Number of unrecovered RTO timeouts. */
299
300 __u16 advmss; /* Advertised MSS */
301 __u32 window_clamp; /* Maximal window to advertise */
302 __u32 rcv_ssthresh; /* Current window clamp */
303
304 __u32 frto_highmark; /* snd_nxt when RTO occurred */
305 __u8 reordering; /* Packet reordering metric. */
306 __u8 frto_counter; /* Number of new acks after RTO */
307
308 __u8 adv_cong; /* Using Vegas, Westwood, or BIC */
309 __u8 defer_accept; /* User waits for some data after accept() */
310
311/* RTT measurement */
312 __u32 srtt; /* smoothed round trip time << 3 */
313 __u32 mdev; /* medium deviation */
314 __u32 mdev_max; /* maximal mdev for the last rtt period */
315 __u32 rttvar; /* smoothed mdev_max */
316 __u32 rtt_seq; /* sequence number to update rttvar */
317 __u32 rto; /* retransmit timeout */
318
319 __u32 packets_out; /* Packets which are "in flight" */
320 __u32 left_out; /* Packets which leaved network */
321 __u32 retrans_out; /* Retransmitted packets out */
322 __u8 backoff; /* backoff */
323/*
324 * Options received (usually on last packet, some only on SYN packets).
325 */
326 __u8 nonagle; /* Disable Nagle algorithm? */
327 __u8 keepalive_probes; /* num of allowed keep alive probes */
328
329 __u8 probes_out; /* unanswered 0 window probes */
330 struct tcp_options_received rx_opt;
331
332/*
333 * Slow start and congestion control (see also Nagle, and Karn & Partridge)
334 */
335 __u32 snd_ssthresh; /* Slow start size threshold */
336 __u32 snd_cwnd; /* Sending congestion window */
337 __u16 snd_cwnd_cnt; /* Linear increase counter */
338 __u16 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
339 __u32 snd_cwnd_used;
340 __u32 snd_cwnd_stamp;
341
342 /* Two commonly used timers in both sender and receiver paths. */
343 unsigned long timeout;
344 struct timer_list retransmit_timer; /* Resend (no ack) */
345 struct timer_list delack_timer; /* Ack delay */
346
347 struct sk_buff_head out_of_order_queue; /* Out of order segments go here */
348
349 struct tcp_func *af_specific; /* Operations which are AF_INET{4,6} specific */
350
351 __u32 rcv_wnd; /* Current receiver window */
352 __u32 rcv_wup; /* rcv_nxt on last window update sent */
353 __u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
354 __u32 pushed_seq; /* Last pushed seq, required to talk to windows */
355 __u32 copied_seq; /* Head of yet unread data */
356
357/* SACKs data */
358 struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
359 struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
360
361 __u8 syn_retries; /* num of allowed syn retries */
362 __u8 ecn_flags; /* ECN status bits. */
363 __u16 prior_ssthresh; /* ssthresh saved at recovery start */
364 __u32 lost_out; /* Lost packets */
365 __u32 sacked_out; /* SACK'd packets */
366 __u32 fackets_out; /* FACK'd packets */
367 __u32 high_seq; /* snd_nxt at onset of congestion */
368
369 __u32 retrans_stamp; /* Timestamp of the last retransmit,
370 * also used in SYN-SENT to remember stamp of
371 * the first SYN. */
372 __u32 undo_marker; /* tracking retrans started here. */
373 int undo_retrans; /* number of undoable retransmissions. */
374 __u32 urg_seq; /* Seq of received urgent pointer */
375 __u16 urg_data; /* Saved octet of OOB data and control flags */
376 __u8 pending; /* Scheduled timer event */
377 __u8 urg_mode; /* In urgent mode */
378 __u32 snd_up; /* Urgent pointer */
379
380 __u32 total_retrans; /* Total retransmits for entire connection */
381
Arnaldo Carvalho de Melo0e875062005-06-18 22:47:59 -0700382 struct request_sock_queue accept_queue; /* FIFO of established children */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
384 unsigned int keepalive_time; /* time before keep alive takes place */
385 unsigned int keepalive_intvl; /* time interval between keep alive probes */
386 int linger2;
387
388 unsigned long last_synq_overflow;
389
390/* Receiver side RTT estimation */
391 struct {
392 __u32 rtt;
393 __u32 seq;
394 __u32 time;
395 } rcv_rtt_est;
396
397/* Receiver queue space */
398 struct {
399 int space;
400 __u32 seq;
401 __u32 time;
402 } rcvq_space;
403
404/* TCP Westwood structure */
405 struct {
406 __u32 bw_ns_est; /* first bandwidth estimation..not too smoothed 8) */
407 __u32 bw_est; /* bandwidth estimate */
408 __u32 rtt_win_sx; /* here starts a new evaluation... */
409 __u32 bk;
410 __u32 snd_una; /* used for evaluating the number of acked bytes */
411 __u32 cumul_ack;
412 __u32 accounted;
413 __u32 rtt;
414 __u32 rtt_min; /* minimum observed RTT */
415 } westwood;
416
417/* Vegas variables */
418 struct {
419 __u32 beg_snd_nxt; /* right edge during last RTT */
420 __u32 beg_snd_una; /* left edge during last RTT */
421 __u32 beg_snd_cwnd; /* saves the size of the cwnd */
422 __u8 doing_vegas_now;/* if true, do vegas for this RTT */
423 __u16 cntRTT; /* # of RTTs measured within last RTT */
424 __u32 minRTT; /* min of RTTs measured within last RTT (in usec) */
425 __u32 baseRTT; /* the min of all Vegas RTT measurements seen (in usec) */
426 } vegas;
427
428 /* BI TCP Parameters */
429 struct {
430 __u32 cnt; /* increase cwnd by 1 after this number of ACKs */
431 __u32 last_max_cwnd; /* last maximium snd_cwnd */
432 __u32 last_cwnd; /* the last snd_cwnd */
433 __u32 last_stamp; /* time when updated last_cwnd */
434 } bictcp;
435};
436
437static inline struct tcp_sock *tcp_sk(const struct sock *sk)
438{
439 return (struct tcp_sock *)sk;
440}
441
442#endif
443
444#endif /* _LINUX_TCP_H */