tcp_var.h revision 1.44 1 /* $NetBSD: tcp_var.h,v 1.44 1998/04/30 17:55:27 thorpej Exp $ */
2
3 /*-
4 * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 /*
41 * Copyright (c) 1982, 1986, 1993, 1994, 1995
42 * The Regents of the University of California. All rights reserved.
43 *
44 * Redistribution and use in source and binary forms, with or without
45 * modification, are permitted provided that the following conditions
46 * are met:
47 * 1. Redistributions of source code must retain the above copyright
48 * notice, this list of conditions and the following disclaimer.
49 * 2. Redistributions in binary form must reproduce the above copyright
50 * notice, this list of conditions and the following disclaimer in the
51 * documentation and/or other materials provided with the distribution.
52 * 3. All advertising materials mentioning features or use of this software
53 * must display the following acknowledgement:
54 * This product includes software developed by the University of
55 * California, Berkeley and its contributors.
56 * 4. Neither the name of the University nor the names of its contributors
57 * may be used to endorse or promote products derived from this software
58 * without specific prior written permission.
59 *
60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
63 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
70 * SUCH DAMAGE.
71 *
72 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
73 */
74
75 #ifndef _NETINET_TCP_VAR_H_
76 #define _NETINET_TCP_VAR_H_
77
78 /*
79 * Kernel variables for tcp.
80 */
81
82 /*
83 * Tcp control block, one per tcp; fields:
84 */
85 struct tcpcb {
86 struct ipqehead segq; /* sequencing queue */
87 short t_state; /* state of this connection */
88 short t_timer[TCPT_NTIMERS]; /* tcp timers */
89 short t_rxtshift; /* log(2) of rexmt exp. backoff */
90 short t_rxtcur; /* current retransmit value */
91 short t_dupacks; /* consecutive dup acks recd */
92 u_short t_peermss; /* peer's maximum segment size */
93 u_short t_ourmss; /* our's maximum segment size */
94 u_short t_segsz; /* current segment size in use */
95 char t_force; /* 1 if forcing out a byte */
96 u_short t_flags;
97 #define TF_ACKNOW 0x0001 /* ack peer immediately */
98 #define TF_DELACK 0x0002 /* ack, but try to delay it */
99 #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */
100 #define TF_NOOPT 0x0008 /* don't use tcp options */
101 #define TF_SENTFIN 0x0010 /* have sent FIN */
102 #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */
103 #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */
104 #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */
105 #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */
106 #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */
107 #define TF_SYN_REXMT 0x0400 /* rexmit timer fired on SYN */
108 #define TF_WILL_SACK 0x0800 /* try to use SACK */
109 #define TF_CANT_TXSACK 0x1000 /* other side said I could not SACK */
110 #define TF_IGNR_RXSACK 0x2000 /* ignore received SACK blocks */
111
112
113 struct tcpiphdr *t_template; /* skeletal packet for transmit */
114 struct inpcb *t_inpcb; /* back pointer to internet pcb */
115 LIST_ENTRY(tcpcb) t_delack; /* delayed ACK queue */
116 /*
117 * The following fields are used as in the protocol specification.
118 * See RFC783, Dec. 1981, page 21.
119 */
120 /* send sequence variables */
121 tcp_seq snd_una; /* send unacknowledged */
122 tcp_seq snd_nxt; /* send next */
123 tcp_seq snd_up; /* send urgent pointer */
124 tcp_seq snd_wl1; /* window update seg seq number */
125 tcp_seq snd_wl2; /* window update seg ack number */
126 tcp_seq iss; /* initial send sequence number */
127 u_long snd_wnd; /* send window */
128 /* receive sequence variables */
129 u_long rcv_wnd; /* receive window */
130 tcp_seq rcv_nxt; /* receive next */
131 tcp_seq rcv_up; /* receive urgent pointer */
132 tcp_seq irs; /* initial receive sequence number */
133 /*
134 * Additional variables for this implementation.
135 */
136 /* receive variables */
137 tcp_seq rcv_adv; /* advertised window */
138 /* retransmit variables */
139 tcp_seq snd_max; /* highest sequence number sent;
140 * used to recognize retransmits
141 */
142 /* congestion control (for slow start, source quench, retransmit after loss) */
143 u_long snd_cwnd; /* congestion-controlled window */
144 u_long snd_ssthresh; /* snd_cwnd size threshhold for
145 * for slow start exponential to
146 * linear switch
147 */
148 /*
149 * transmit timing stuff. See below for scale of srtt and rttvar.
150 * "Variance" is actually smoothed difference.
151 */
152 short t_idle; /* inactivity time */
153 short t_rtt; /* round trip time */
154 tcp_seq t_rtseq; /* sequence number being timed */
155 short t_srtt; /* smoothed round-trip time */
156 short t_rttvar; /* variance in round-trip time */
157 short t_rttmin; /* minimum rtt allowed */
158 u_long max_sndwnd; /* largest window peer has offered */
159
160 /* out-of-band data */
161 char t_oobflags; /* have some */
162 char t_iobc; /* input character */
163 #define TCPOOB_HAVEDATA 0x01
164 #define TCPOOB_HADDATA 0x02
165 short t_softerror; /* possible error not yet reported */
166
167 /* RFC 1323 variables */
168 u_char snd_scale; /* window scaling for send window */
169 u_char rcv_scale; /* window scaling for recv window */
170 u_char request_r_scale; /* pending window scaling */
171 u_char requested_s_scale;
172 u_int32_t ts_recent; /* timestamp echo data */
173 u_int32_t ts_recent_age; /* when last updated */
174 tcp_seq last_ack_sent;
175
176 /* TUBA stuff */
177 caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */
178 /* SACK stuff */
179 struct ipqehead timeq; /* time sequenced queue (for SACK) */
180 };
181
182 /*
183 * Queue for delayed ACK processing.
184 */
185 LIST_HEAD(tcp_delack_head, tcpcb);
186 #ifdef _KERNEL
187 extern struct tcp_delack_head tcp_delacks;
188
189 #define TCP_SET_DELACK(tp) \
190 do { \
191 if (((tp)->t_flags & TF_DELACK) == 0) { \
192 (tp)->t_flags |= TF_DELACK; \
193 LIST_INSERT_HEAD(&tcp_delacks, (tp), t_delack); \
194 } \
195 } while (0)
196
197 #define TCP_CLEAR_DELACK(tp) \
198 do { \
199 if ((tp)->t_flags & TF_DELACK) { \
200 (tp)->t_flags &= ~TF_DELACK; \
201 LIST_REMOVE((tp), t_delack); \
202 } \
203 } while (0)
204 #endif /* _KERNEL */
205
206 /*
207 * Handy way of passing around TCP option info.
208 */
209 struct tcp_opt_info {
210 int ts_present;
211 u_int32_t ts_val;
212 u_int32_t ts_ecr;
213 u_int16_t maxseg;
214 };
215
216 /*
217 * Data for the TCP compressed state engine.
218 */
219 struct syn_cache {
220 struct syn_cache *sc_next;
221 u_int32_t sc_hash;
222 struct in_addr sc_src;
223 struct in_addr sc_dst;
224 tcp_seq sc_irs;
225 tcp_seq sc_iss;
226 int sc_flags;
227
228 #define SCF_SYNACK_REXMT 0x0001 /* SYN,ACK was retransmitted */
229 #define SCF_TIMESTAMP 0x0002 /* peer will do timestamps */
230
231 struct mbuf *sc_ipopts; /* IP options */
232 u_int16_t sc_sport;
233 u_int16_t sc_dport;
234 u_int16_t sc_peermaxseg;
235 u_int16_t sc_ourmaxseg;
236 u_int8_t sc_timer;
237 u_int8_t sc_request_r_scale : 4,
238 sc_requested_s_scale : 4;
239 };
240
241 struct syn_cache_head {
242 struct syn_cache *sch_first; /* First entry in the bucket */
243 struct syn_cache *sch_last; /* Last entry in the bucket */
244 struct syn_cache_head *sch_headq; /* The next non-empty bucket */
245 int16_t sch_timer_sum; /* Total time in this bucket */
246 u_int16_t sch_length; /* @ # elements in bucket */
247 };
248
249 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
250 #define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
251
252 /*
253 * The smoothed round-trip time and estimated variance
254 * are stored as fixed point numbers scaled by the values below.
255 * For convenience, these scales are also used in smoothing the average
256 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
257 * With these scales, srtt has 3 bits to the right of the binary point,
258 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
259 * binary point, and is smoothed with an ALPHA of 0.75.
260 */
261 #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
262 #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */
263
264 /*
265 * The initial retransmission should happen at rtt + 4 * rttvar.
266 * Because of the way we do the smoothing, srtt and rttvar
267 * will each average +1/2 tick of bias. When we compute
268 * the retransmit timer, we want 1/2 tick of rounding and
269 * 1 extra tick because of +-1/2 tick uncertainty in the
270 * firing of the timer. The bias will give us exactly the
271 * 1.5 tick we need. But, because the bias is
272 * statistical, we have to test that we don't drop below
273 * the minimum feasible timer (which is 2 ticks).
274 * This macro assumes that the value of 1<<TCP_RTTVAR_SHIFT
275 * is the same as the multiplier for rttvar.
276 */
277 #define TCP_REXMTVAL(tp) \
278 ((((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) >> 2)
279
280 #ifdef _KERNEL
281 /*
282 * Compute the initial window for slow start.
283 */
284 extern int tcp_init_win;
285 #define TCP_INITIAL_WINDOW(iw, segsz) \
286 (((iw) == 0) ? (min(4 * (segsz), max(2 * (segsz), 4380))) : \
287 ((segsz) * (iw)))
288 #endif /* _KERNEL */
289
290 /*
291 * TCP statistics.
292 * Many of these should be kept per connection,
293 * but that's inconvenient at the moment.
294 */
295 struct tcpstat {
296 u_long tcps_connattempt; /* connections initiated */
297 u_long tcps_accepts; /* connections accepted */
298 u_long tcps_connects; /* connections established */
299 u_long tcps_drops; /* connections dropped */
300 u_long tcps_conndrops; /* embryonic connections dropped */
301 u_long tcps_closed; /* conn. closed (includes drops) */
302 u_long tcps_segstimed; /* segs where we tried to get rtt */
303 u_long tcps_rttupdated; /* times we succeeded */
304 u_long tcps_delack; /* delayed acks sent */
305 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
306 u_long tcps_rexmttimeo; /* retransmit timeouts */
307 u_long tcps_persisttimeo; /* persist timeouts */
308 u_long tcps_keeptimeo; /* keepalive timeouts */
309 u_long tcps_keepprobe; /* keepalive probes sent */
310 u_long tcps_keepdrops; /* connections dropped in keepalive */
311 u_long tcps_persistdrops; /* connections dropped in persist */
312 u_long tcps_connsdrained; /* connections drained due to memory
313 shortage */
314
315 u_long tcps_sndtotal; /* total packets sent */
316 u_long tcps_sndpack; /* data packets sent */
317 u_long tcps_sndbyte; /* data bytes sent */
318 u_long tcps_sndrexmitpack; /* data packets retransmitted */
319 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
320 u_long tcps_sndacks; /* ack-only packets sent */
321 u_long tcps_sndprobe; /* window probes sent */
322 u_long tcps_sndurg; /* packets sent with URG only */
323 u_long tcps_sndwinup; /* window update-only packets sent */
324 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
325
326 u_long tcps_rcvtotal; /* total packets received */
327 u_long tcps_rcvpack; /* packets received in sequence */
328 u_long tcps_rcvbyte; /* bytes received in sequence */
329 u_long tcps_rcvbadsum; /* packets received with ccksum errs */
330 u_long tcps_rcvbadoff; /* packets received with bad offset */
331 u_long tcps_rcvmemdrop; /* packets dropped for lack of memory */
332 u_long tcps_rcvshort; /* packets received too short */
333 u_long tcps_rcvduppack; /* duplicate-only packets received */
334 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
335 u_long tcps_rcvpartduppack; /* packets with some duplicate data */
336 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
337 u_long tcps_rcvoopack; /* out-of-order packets received */
338 u_long tcps_rcvoobyte; /* out-of-order bytes received */
339 u_long tcps_rcvpackafterwin; /* packets with data after window */
340 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
341 u_long tcps_rcvafterclose; /* packets rcvd after "close" */
342 u_long tcps_rcvwinprobe; /* rcvd window probe packets */
343 u_long tcps_rcvdupack; /* rcvd duplicate acks */
344 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
345 u_long tcps_rcvackpack; /* rcvd ack packets */
346 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
347 u_long tcps_rcvwinupd; /* rcvd window update packets */
348 u_long tcps_pawsdrop; /* segments dropped due to PAWS */
349 u_long tcps_predack; /* times hdr predict ok for acks */
350 u_long tcps_preddat; /* times hdr predict ok for data pkts */
351
352 u_long tcps_pcbhashmiss; /* input packets missing pcb hash */
353 u_long tcps_noport; /* no socket on port */
354 u_long tcps_badsyn; /* received ack for which we have
355 no SYN in compressed state */
356
357 /* These statistics deal with the SYN cache. */
358 u_long tcps_sc_added; /* # of entries added */
359 u_long tcps_sc_completed; /* # of connections completed */
360 u_long tcps_sc_timed_out; /* # of entries timed out */
361 u_long tcps_sc_overflowed; /* # dropped due to overflow */
362 u_long tcps_sc_reset; /* # dropped due to RST */
363 u_long tcps_sc_unreach; /* # dropped due to ICMP unreach */
364 u_long tcps_sc_bucketoverflow; /* # dropped due to bucket overflow */
365 u_long tcps_sc_aborted; /* # of entries aborted (no mem) */
366 u_long tcps_sc_dupesyn; /* # of duplicate SYNs received */
367 u_long tcps_sc_dropped; /* # of SYNs dropped (no route/mem) */
368 u_long tcps_sc_collisions; /* # of hash collisions */
369 };
370
371 /*
372 * Names for TCP sysctl objects.
373 */
374 #define TCPCTL_RFC1323 1 /* RFC1323 timestamps/scaling */
375 #define TCPCTL_SENDSPACE 2 /* default send buffer */
376 #define TCPCTL_RECVSPACE 3 /* default recv buffer */
377 #define TCPCTL_MSSDFLT 4 /* default seg size */
378 #define TCPCTL_SYN_CACHE_LIMIT 5 /* max size of comp. state engine */
379 #define TCPCTL_SYN_BUCKET_LIMIT 6 /* max size of hash bucket */
380 #define TCPCTL_SYN_CACHE_INTER 7 /* interval of comp. state timer */
381 #define TCPCTL_INIT_WIN 8 /* initial window */
382 #define TCPCTL_MSS_IFMTU 9 /* mss from interface, not in_maxmtu */
383 #define TCPCTL_SACK 10 /* RFC2018 selective acknowledgement */
384 #define TCPCTL_WSCALE 11 /* RFC1323 window scaling */
385 #define TCPCTL_TSTAMP 12 /* RFC1323 timestamps */
386 #define TCPCTL_COMPAT_42 13 /* 4.2BSD TCP bug work-arounds */
387 #define TCPCTL_MAXID 14
388
389 #define TCPCTL_NAMES { \
390 { 0, 0 }, \
391 { "rfc1323", CTLTYPE_INT }, \
392 { "sendspace", CTLTYPE_INT }, \
393 { "recvspace", CTLTYPE_INT }, \
394 { "mssdflt", CTLTYPE_INT }, \
395 { "syn_cache_limit", CTLTYPE_INT }, \
396 { "syn_bucket_limit", CTLTYPE_INT }, \
397 { "syn_cache_interval", CTLTYPE_INT },\
398 { "init_win", CTLTYPE_INT }, \
399 { "mss_ifmtu", CTLTYPE_INT }, \
400 { "sack", CTLTYPE_INT }, \
401 { "win_scale", CTLTYPE_INT }, \
402 { "timestamps", CTLTYPE_INT }, \
403 { "compat_42", CTLTYPE_INT }, \
404 }
405
406 #ifdef _KERNEL
407 struct inpcbtable tcbtable; /* head of queue of active tcpcb's */
408 struct tcpstat tcpstat; /* tcp statistics */
409 u_int32_t tcp_now; /* for RFC 1323 timestamps */
410 extern int tcp_do_rfc1323; /* enabled/disabled? */
411 extern int tcp_do_sack; /* SACK enabled/disabled? */
412 extern int tcp_do_win_scale; /* RFC1323 window scaling enabled/disabled? */
413 extern int tcp_do_timestamps; /* RFC1323 timestamps enabled/disabled? */
414 extern int tcp_mssdflt; /* default seg size */
415 extern int tcp_init_win; /* initial window */
416 extern int tcp_mss_ifmtu; /* take MSS from interface, not in_maxmtu */
417 extern int tcp_compat_42; /* work around ancient broken TCP peers */
418 extern int tcp_syn_cache_limit; /* max entries for compressed state engine */
419 extern int tcp_syn_bucket_limit;/* max entries per hash bucket */
420 extern int tcp_syn_cache_interval; /* compressed state timer */
421
422 extern int tcp_syn_cache_size;
423 extern int tcp_syn_cache_timeo;
424 extern struct syn_cache_head tcp_syn_cache[], *tcp_syn_cache_first;
425 extern u_long syn_cache_count;
426
427 #define TCPCTL_VARIABLES { \
428 NULL, \
429 &tcp_do_rfc1323, \
430 &tcp_sendspace, \
431 &tcp_recvspace, \
432 &tcp_mssdflt, \
433 &tcp_syn_cache_limit, \
434 &tcp_syn_bucket_limit, \
435 &tcp_syn_cache_interval, \
436 &tcp_init_win, \
437 &tcp_mss_ifmtu, \
438 &tcp_do_sack, \
439 &tcp_do_win_scale, \
440 &tcp_do_timestamps, \
441 &tcp_compat_42, \
442 }
443
444 int tcp_attach __P((struct socket *));
445 void tcp_canceltimers __P((struct tcpcb *));
446 struct tcpcb *
447 tcp_close __P((struct tcpcb *));
448 void *tcp_ctlinput __P((int, struct sockaddr *, void *));
449 int tcp_ctloutput __P((int, struct socket *, int, int, struct mbuf **));
450 struct tcpcb *
451 tcp_disconnect __P((struct tcpcb *));
452 struct tcpcb *
453 tcp_drop __P((struct tcpcb *, int));
454 void tcp_dooptions __P((struct tcpcb *,
455 u_char *, int, struct tcpiphdr *, struct tcp_opt_info *));
456 void tcp_drain __P((void));
457 void tcp_established __P((struct tcpcb *));
458 void tcp_fasttimo __P((void));
459 void tcp_init __P((void));
460 void tcp_input __P((struct mbuf *, ...));
461 u_long tcp_mss_to_advertise __P((const struct ifnet *));
462 void tcp_mss_from_peer __P((struct tcpcb *, int));
463 void tcp_mtudisc __P((struct inpcb *, int));
464 struct tcpcb *
465 tcp_newtcpcb __P((struct inpcb *));
466 void tcp_notify __P((struct inpcb *, int));
467 u_int tcp_optlen __P((struct tcpcb *));
468 int tcp_output __P((struct tcpcb *));
469 void tcp_pulloutofband __P((struct socket *,
470 struct tcpiphdr *, struct mbuf *));
471 void tcp_quench __P((struct inpcb *, int));
472 int tcp_reass __P((struct tcpcb *, struct tcpiphdr *, struct mbuf *));
473 int tcp_respond __P((struct tcpcb *,
474 struct tcpiphdr *, struct mbuf *, tcp_seq, tcp_seq, int));
475 void tcp_rmx_rtt __P((struct tcpcb *));
476 void tcp_setpersist __P((struct tcpcb *));
477 void tcp_slowtimo __P((void));
478 struct tcpiphdr *
479 tcp_template __P((struct tcpcb *));
480 struct tcpcb *
481 tcp_timers __P((struct tcpcb *, int));
482 void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int));
483 struct tcpcb *
484 tcp_usrclosed __P((struct tcpcb *));
485 int tcp_sysctl __P((int *, u_int, void *, size_t *, void *, size_t));
486 int tcp_usrreq __P((struct socket *,
487 int, struct mbuf *, struct mbuf *, struct mbuf *, struct proc *));
488 void tcp_xmit_timer __P((struct tcpcb *, int));
489 tcp_seq tcp_new_iss __P((void *, u_long, tcp_seq));
490
491 int syn_cache_add __P((struct socket *, struct mbuf *, u_char *,
492 int, struct tcp_opt_info *));
493 void syn_cache_unreach __P((struct ip *, struct tcphdr *));
494 struct socket *
495 syn_cache_get __P((struct socket *so, struct mbuf *));
496 void syn_cache_insert __P((struct syn_cache *, struct syn_cache ***,
497 struct syn_cache_head **));
498 struct syn_cache *
499 syn_cache_lookup __P((struct tcpiphdr *, struct syn_cache ***,
500 struct syn_cache_head **));
501 void syn_cache_reset __P((struct tcpiphdr *));
502 int syn_cache_respond __P((struct syn_cache *, struct mbuf *,
503 register struct tcpiphdr *, long, u_long));
504 void syn_cache_timer __P((int));
505
506 #endif
507
508 #endif /* _NETINET_TCP_VAR_H_ */
509