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[dragonfly.git] / sys / netinet / tcp_var.h
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1 /*
2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
5 * This code is derived from software contributed to The DragonFly Project
6 * by Jeffrey M. Hsu.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of The DragonFly Project nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific, prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
35 * Copyright (c) 1982, 1986, 1993, 1994, 1995
36 * The Regents of the University of California. All rights reserved.
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. All advertising materials mentioning features or use of this software
47 * must display the following acknowledgement:
48 * This product includes software developed by the University of
49 * California, Berkeley and its contributors.
50 * 4. Neither the name of the University nor the names of its contributors
51 * may be used to endorse or promote products derived from this software
52 * without specific prior written permission.
54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64 * SUCH DAMAGE.
66 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
67 * $FreeBSD: src/sys/netinet/tcp_var.h,v 1.56.2.13 2003/02/03 02:34:07 hsu Exp $
68 * $DragonFly: src/sys/netinet/tcp_var.h,v 1.40 2007/12/19 11:00:22 sephe Exp $
71 #ifndef _NETINET_TCP_VAR_H_
72 #define _NETINET_TCP_VAR_H_
74 #ifndef _NETINET_IN_PCB_H_
75 #include <netinet/in_pcb.h> /* needed for in_conninfo, inp_gen_t */
76 #endif
77 #ifndef _NETINET_TCP_H_
78 #include <netinet/tcp.h>
79 #endif
82 * Kernel variables for tcp.
84 extern int tcp_do_rfc1323;
85 extern int tcp_do_rfc1644;
86 extern int tcp_do_rfc3390;
87 extern int tcp_do_sack;
88 extern int tcp_do_smartsack;
89 extern int tcp_aggregate_acks;
91 /* TCP segment queue entry */
92 struct tseg_qent {
93 LIST_ENTRY(tseg_qent) tqe_q;
94 int tqe_len; /* TCP segment data length */
95 struct tcphdr *tqe_th; /* a pointer to tcp header */
96 struct mbuf *tqe_m; /* mbuf contains packet */
98 LIST_HEAD(tsegqe_head, tseg_qent);
99 extern int tcp_reass_maxseg;
100 extern int tcp_reass_qsize;
101 #ifdef MALLOC_DECLARE
102 MALLOC_DECLARE(M_TSEGQ);
103 #endif
105 struct tcptemp {
106 u_char tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
107 struct tcphdr tt_t;
110 #define tcp6cb tcpcb /* for KAME src sync over BSD*'s */
112 struct raw_sackblock { /* covers [start, end) */
113 tcp_seq rblk_start;
114 tcp_seq rblk_end;
117 /* maximum number of SACK blocks that will fit in the TCP option space */
118 #define MAX_SACK_REPORT_BLOCKS 4
120 TAILQ_HEAD(sackblock_list, sackblock);
122 struct scoreboard {
123 int nblocks;
124 struct sackblock_list sackblocks;
125 tcp_seq lostseq; /* passed SACK lost test */
126 struct sackblock *lastfound; /* search hint */
130 * Tcp control block, one per tcp; fields:
131 * Organized for 16 byte cacheline efficiency.
133 struct tcpcb {
134 struct tsegqe_head t_segq;
135 int t_dupacks; /* consecutive dup acks recd */
136 int tt_cpu; /* sanity check the cpu */
137 struct callout *tt_rexmt; /* retransmit timer */
139 struct callout *tt_persist; /* retransmit persistence */
140 struct callout *tt_keep; /* keepalive */
141 struct callout *tt_2msl; /* 2*msl TIME_WAIT timer */
142 struct callout *tt_delack; /* delayed ACK timer */
144 struct inpcb *t_inpcb; /* back pointer to internet pcb */
145 int t_state; /* state of this connection */
146 u_int t_flags;
147 #define TF_ACKNOW 0x00000001 /* ack peer immediately */
148 #define TF_DELACK 0x00000002 /* ack, but try to delay it */
149 #define TF_NODELAY 0x00000004 /* don't delay packets to coalesce */
150 #define TF_NOOPT 0x00000008 /* don't use tcp options */
151 #define TF_SENTFIN 0x00000010 /* have sent FIN */
152 #define TF_REQ_SCALE 0x00000020 /* have/will request window scaling */
153 #define TF_RCVD_SCALE 0x00000040 /* other side has requested scaling */
154 #define TF_REQ_TSTMP 0x00000080 /* have/will request timestamps */
155 #define TF_RCVD_TSTMP 0x00000100 /* a timestamp was received in SYN */
156 #define TF_SACK_PERMITTED 0x00000200 /* other side said I could SACK */
157 #define TF_NEEDSYN 0x00000400 /* send SYN (implicit state) */
158 #define TF_NEEDFIN 0x00000800 /* send FIN (implicit state) */
159 #define TF_NOPUSH 0x00001000 /* don't push */
160 #define TF_REQ_CC 0x00002000 /* have/will request CC */
161 #define TF_RCVD_CC 0x00004000 /* a CC was received in SYN */
162 #define TF_SENDCCNEW 0x00008000 /* send CCnew instead of CC in SYN */
163 #define TF_MORETOCOME 0x00010000 /* More data to be appended to sock */
164 #define TF_LQ_OVERFLOW 0x00020000 /* listen queue overflow */
165 #define TF_LASTIDLE 0x00040000 /* connection was previously idle */
166 #define TF_RXWIN0SENT 0x00080000 /* sent a receiver win 0 in response */
167 #define TF_FASTRECOVERY 0x00100000 /* in NewReno Fast Recovery */
168 #define TF_WASFRECOVERY 0x00200000 /* was in NewReno Fast Recovery */
169 #define TF_FIRSTACCACK 0x00400000 /* Look for 1st acceptable ACK. */
170 #define TF_FASTREXMT 0x00800000 /* Did Fast Retransmit. */
171 #define TF_EARLYREXMT 0x01000000 /* Did Early (Fast) Retransmit. */
172 #define TF_FORCE 0x02000000 /* Set if forcing out a byte */
173 #define TF_ONOUTPUTQ 0x04000000 /* on t_outputq list */
174 #define TF_DUPSEG 0x08000000 /* last seg a duplicate */
175 #define TF_ENCLOSESEG 0x10000000 /* enclosing SACK block */
176 #define TF_SACKLEFT 0x20000000 /* send SACK blocks from left side */
177 tcp_seq snd_up; /* send urgent pointer */
179 tcp_seq snd_una; /* send unacknowledged */
180 tcp_seq snd_recover; /* for use with NewReno Fast Recovery */
181 tcp_seq snd_max; /* highest sequence number sent;
182 * used to recognize retransmits */
183 tcp_seq snd_nxt; /* send next */
185 tcp_seq snd_wl1; /* window update seg seq number */
186 tcp_seq snd_wl2; /* window update seg ack number */
187 tcp_seq iss; /* initial send sequence number */
188 tcp_seq irs; /* initial receive sequence number */
190 tcp_seq rcv_nxt; /* receive next */
191 tcp_seq rcv_adv; /* advertised window */
192 u_long rcv_wnd; /* receive window */
193 tcp_seq rcv_up; /* receive urgent pointer */
195 u_long snd_wnd; /* send window */
196 u_long snd_cwnd; /* congestion-controlled window */
197 u_long snd_wacked; /* bytes acked in one send window */
198 u_long snd_ssthresh; /* snd_cwnd size threshold for
199 * for slow start exponential to
200 * linear switch */
202 int t_rxtcur; /* current retransmit value (ticks) */
203 u_int t_maxseg; /* maximum segment size */
204 int t_srtt; /* smoothed round-trip time */
205 int t_rttvar; /* variance in round-trip time */
207 u_int t_maxopd; /* mss plus options */
209 u_long t_rcvtime; /* inactivity time */
210 u_long t_starttime; /* time connection was established */
211 int t_rtttime; /* round trip time */
212 tcp_seq t_rtseq; /* sequence number being timed */
214 int t_rxtshift; /* log(2) of rexmt exp. backoff */
215 u_int t_rttmin; /* minimum rtt allowed */
216 u_int t_rttbest; /* best rtt we've seen */
217 u_long t_rttupdated; /* number of times rtt sampled */
218 u_long max_sndwnd; /* largest window peer has offered */
220 int t_softerror; /* possible error not yet reported */
221 /* out-of-band data */
222 char t_oobflags; /* have some */
223 char t_iobc; /* input character */
224 #define TCPOOB_HAVEDATA 0x01
225 #define TCPOOB_HADDATA 0x02
227 /* RFC 1323 variables */
228 u_char snd_scale; /* window scaling for send window */
229 u_char rcv_scale; /* window scaling for recv window */
230 u_char request_r_scale; /* pending window scaling */
231 u_char requested_s_scale;
232 u_long ts_recent; /* timestamp echo data */
234 u_long ts_recent_age; /* when last updated */
235 tcp_seq last_ack_sent;
237 /* RFC 1644 variables */
238 tcp_cc cc_send; /* send connection count */
239 tcp_cc cc_recv; /* receive connection count */
241 /* experimental */
242 u_long snd_cwnd_prev; /* cwnd prior to retransmit */
243 u_long snd_wacked_prev; /* prior bytes acked in send window */
244 u_long snd_ssthresh_prev; /* ssthresh prior to retransmit */
245 tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */
246 u_long t_badrxtwin; /* window for retransmit recovery */
247 u_long t_rexmtTS; /* timestamp of last retransmit */
248 u_char snd_limited; /* segments limited transmitted */
250 tcp_seq rexmt_high; /* highest seq # retransmitted + 1 */
251 tcp_seq snd_max_rexmt; /* snd_max when rexmting snd_una */
252 struct scoreboard scb; /* sack scoreboard */
253 struct raw_sackblock reportblk; /* incoming segment or D-SACK block */
254 struct raw_sackblock encloseblk;
255 int nsackhistory;
256 struct raw_sackblock sackhistory[MAX_SACK_REPORT_BLOCKS]; /* reported */
257 TAILQ_ENTRY(tcpcb) t_outputq; /* tcp_output needed list */
259 /* bandwith limitation */
260 u_long snd_bandwidth; /* calculated bandwidth or 0 */
261 u_long snd_bwnd; /* bandwidth-controlled window */
262 int t_bw_rtttime; /* used for bandwidth calculation */
263 tcp_seq t_bw_rtseq; /* used for bandwidth calculation */
266 #define IN_FASTRECOVERY(tp) (tp->t_flags & TF_FASTRECOVERY)
267 #define ENTER_FASTRECOVERY(tp) tp->t_flags |= TF_FASTRECOVERY
268 #define EXIT_FASTRECOVERY(tp) tp->t_flags &= ~TF_FASTRECOVERY
271 * TCP statistics.
273 struct tcp_stats {
274 u_long tcps_connattempt; /* connections initiated */
275 u_long tcps_accepts; /* connections accepted */
276 u_long tcps_connects; /* connections established */
277 u_long tcps_drops; /* connections dropped */
278 u_long tcps_conndrops; /* embryonic connections dropped */
279 u_long tcps_closed; /* conn. closed (includes drops) */
280 u_long tcps_segstimed; /* segs where we tried to get rtt */
281 u_long tcps_rttupdated; /* times we succeeded */
282 u_long tcps_delack; /* delayed acks sent */
283 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
284 u_long tcps_rexmttimeo; /* retransmit timeouts */
285 u_long tcps_persisttimeo; /* persist timeouts */
286 u_long tcps_keeptimeo; /* keepalive timeouts */
287 u_long tcps_keepprobe; /* keepalive probes sent */
288 u_long tcps_keepdrops; /* connections dropped in keepalive */
290 u_long tcps_sndtotal; /* total packets sent */
291 u_long tcps_sndpack; /* data packets sent */
292 u_long tcps_sndbyte; /* data bytes sent */
293 u_long tcps_sndrexmitpack; /* data packets retransmitted */
294 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
295 u_long tcps_sndfastrexmit; /* Fast Retransmissions */
296 u_long tcps_sndearlyrexmit; /* early Fast Retransmissions */
297 u_long tcps_sndlimited; /* Limited Transmit packets */
298 u_long tcps_sndrtobad; /* spurious RTO retransmissions */
299 u_long tcps_sndfastrexmitbad; /* spurious Fast Retransmissions */
300 u_long tcps_sndearlyrexmitbad; /* spurious early Fast Retransmissions,
301 a subset of tcps_sndfastrexmitbad */
302 u_long tcps_eifeldetected; /* Eifel-detected spurious rexmits */
303 u_long tcps_rttcantdetect; /* Eifel but not 1/2 RTT-detectable */
304 u_long tcps_rttdetected; /* RTT-detected spurious RTO rexmits */
305 u_long tcps_sndacks; /* ack-only packets sent */
306 u_long tcps_sndprobe; /* window probes sent */
307 u_long tcps_sndurg; /* packets sent with URG only */
308 u_long tcps_sndwinup; /* window update-only packets sent */
309 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
310 u_long tcps_sndsackpack; /* packets sent by SACK recovery alg */
311 u_long tcps_sndsackbyte; /* bytes sent by SACK recovery */
312 u_long tcps_snduna3; /* re-retransmit snd_una on 3 new seg */
313 u_long tcps_snduna1; /* re-retransmit snd_una on 1 new seg */
315 u_long tcps_rcvtotal; /* total packets received */
316 u_long tcps_rcvpack; /* packets received in sequence */
317 u_long tcps_rcvbyte; /* bytes received in sequence */
318 u_long tcps_rcvbadsum; /* packets received with ccksum errs */
319 u_long tcps_rcvbadoff; /* packets received with bad offset */
320 u_long tcps_rcvmemdrop; /* packets dropped for lack of memory */
321 u_long tcps_rcvshort; /* packets received too short */
322 u_long tcps_rcvduppack; /* duplicate-only packets received */
323 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
324 u_long tcps_rcvpartduppack; /* packets with some duplicate data */
325 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
326 u_long tcps_rcvoopack; /* out-of-order packets received */
327 u_long tcps_rcvoobyte; /* out-of-order bytes received */
328 u_long tcps_rcvpackafterwin; /* packets with data after window */
329 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
330 u_long tcps_rcvafterclose; /* packets rcvd after "close" */
331 u_long tcps_rcvwinprobe; /* rcvd window probe packets */
332 u_long tcps_rcvdupack; /* rcvd duplicate acks */
333 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
334 u_long tcps_rcvackpack; /* rcvd ack packets */
335 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
336 u_long tcps_rcvwinupd; /* rcvd window update packets */
337 u_long tcps_pawsdrop; /* segments dropped due to PAWS */
338 u_long tcps_predack; /* times hdr predict ok for acks */
339 u_long tcps_preddat; /* times hdr predict ok for data pkts */
340 u_long tcps_pcbcachemiss;
341 u_long tcps_cachedrtt; /* times cached RTT in route updated */
342 u_long tcps_cachedrttvar; /* times cached rttvar updated */
343 u_long tcps_cachedssthresh; /* times cached ssthresh updated */
344 u_long tcps_usedrtt; /* times RTT initialized from route */
345 u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */
346 u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/
347 u_long tcps_persistdrop; /* timeout in persist state */
348 u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
349 u_long tcps_mturesent; /* resends due to MTU discovery */
350 u_long tcps_listendrop; /* listen queue overflows */
352 u_long tcps_sc_added; /* entry added to syncache */
353 u_long tcps_sc_retransmitted; /* syncache entry was retransmitted */
354 u_long tcps_sc_dupsyn; /* duplicate SYN packet */
355 u_long tcps_sc_dropped; /* could not reply to packet */
356 u_long tcps_sc_completed; /* successful extraction of entry */
357 u_long tcps_sc_bucketoverflow; /* syncache per-bucket limit hit */
358 u_long tcps_sc_cacheoverflow; /* syncache cache limit hit */
359 u_long tcps_sc_reset; /* RST removed entry from syncache */
360 u_long tcps_sc_stale; /* timed out or listen socket gone */
361 u_long tcps_sc_aborted; /* syncache entry aborted */
362 u_long tcps_sc_badack; /* removed due to bad ACK */
363 u_long tcps_sc_unreach; /* ICMP unreachable received */
364 u_long tcps_sc_zonefail; /* zalloc() failed */
365 u_long tcps_sc_sendcookie; /* SYN cookie sent */
366 u_long tcps_sc_recvcookie; /* SYN cookie received */
369 #ifdef _KERNEL
371 #if defined(SMP)
372 #define tcpstat tcpstats_percpu[mycpuid]
373 #else
374 #define tcpstat tcpstats_percpu[0]
375 #endif
377 struct sockopt;
379 extern struct tcp_stats tcpstats_percpu[MAXCPU];
381 static const int tcprexmtthresh = 3;
382 #endif
385 * Structure to hold TCP options that are only used during segment
386 * processing (in tcp_input), but not held in the tcpcb.
387 * It's basically used to reduce the number of parameters
388 * to tcp_dooptions.
390 struct tcpopt {
391 u_long to_flags; /* which options are present */
392 #define TOF_TS 0x0001 /* timestamp */
393 #define TOF_CC 0x0002 /* CC and CCnew are exclusive */
394 #define TOF_CCNEW 0x0004
395 #define TOF_CCECHO 0x0008
396 #define TOF_MSS 0x0010
397 #define TOF_SCALE 0x0020
398 #define TOF_SACK_PERMITTED 0x0040
399 #define TOF_SACK 0x0080
400 u_int32_t to_tsval;
401 u_int32_t to_tsecr;
402 tcp_cc to_cc; /* holds CC or CCnew */
403 tcp_cc to_ccecho;
404 u_int16_t to_mss;
405 u_int8_t to_requested_s_scale;
406 u_int8_t to_nsackblocks;
407 struct raw_sackblock *to_sackblocks;
410 struct syncache {
411 inp_gen_t sc_inp_gencnt; /* pointer check */
412 struct tcpcb *sc_tp; /* tcb for listening socket */
413 struct mbuf *sc_ipopts; /* source route */
414 struct in_conninfo sc_inc; /* addresses */
415 #define sc_route sc_inc.inc_route
416 #define sc_route6 sc_inc.inc6_route
417 u_int32_t sc_tsrecent;
418 tcp_cc sc_cc_send; /* holds CC or CCnew */
419 tcp_cc sc_cc_recv;
420 tcp_seq sc_irs; /* seq from peer */
421 tcp_seq sc_iss; /* our ISS */
422 u_long sc_rxttime; /* retransmit time */
423 u_int16_t sc_rxtslot; /* retransmit counter */
424 u_int16_t sc_peer_mss; /* peer's MSS */
425 u_int16_t sc_wnd; /* advertised window */
426 u_int8_t sc_requested_s_scale:4,
427 sc_request_r_scale:4;
428 u_int8_t sc_flags;
429 #define SCF_NOOPT 0x01 /* no TCP options */
430 #define SCF_WINSCALE 0x02 /* negotiated window scaling */
431 #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */
432 #define SCF_CC 0x08 /* negotiated CC */
433 #define SCF_UNREACH 0x10 /* icmp unreachable received */
434 #define SCF_SACK_PERMITTED 0x20 /* saw SACK permitted option */
435 TAILQ_ENTRY(syncache) sc_hash;
436 TAILQ_ENTRY(syncache) sc_timerq;
439 struct syncache_head {
440 TAILQ_HEAD(, syncache) sch_bucket;
441 u_int sch_length;
445 * The TAO cache entry which is stored in the protocol family specific
446 * portion of the route metrics.
448 struct rmxp_tao {
449 tcp_cc tao_cc; /* latest CC in valid SYN */
450 tcp_cc tao_ccsent; /* latest CC sent to peer */
451 u_short tao_mssopt; /* peer's cached MSS */
453 #ifdef notyet
454 u_short tao_flags; /* cache status flags */
455 #define TAOF_DONT 0x0001 /* peer doesn't understand rfc1644 */
456 #define TAOF_OK 0x0002 /* peer does understand rfc1644 */
457 #define TAOF_UNDEF 0 /* we don't know yet */
458 #endif
461 #define rmx_taop(rt) ((struct rmxp_tao *)(rt).rmx_filler)
463 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
464 #define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
467 * The smoothed round-trip time and estimated variance
468 * are stored as fixed point numbers scaled by the values below.
469 * For convenience, these scales are also used in smoothing the average
470 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
471 * With these scales, srtt has 3 bits to the right of the binary point,
472 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
473 * binary point, and is smoothed with an ALPHA of 0.75.
475 #define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */
476 #define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */
477 #define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */
478 #define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */
479 #define TCP_DELTA_SHIFT 2 /* see tcp_input.c */
482 * The initial retransmission should happen at rtt + 4 * rttvar.
483 * Because of the way we do the smoothing, srtt and rttvar
484 * will each average +1/2 tick of bias. When we compute
485 * the retransmit timer, we want 1/2 tick of rounding and
486 * 1 extra tick because of +-1/2 tick uncertainty in the
487 * firing of the timer. The bias will give us exactly the
488 * 1.5 tick we need. But, because the bias is
489 * statistical, we have to test that we don't drop below
490 * the minimum feasible timer (which is 2 ticks).
491 * This version of the macro adapted from a paper by Lawrence
492 * Brakmo and Larry Peterson which outlines a problem caused
493 * by insufficient precision in the original implementation,
494 * which results in inappropriately large RTO values for very
495 * fast networks.
497 #define TCP_REXMTVAL(tp) \
498 max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \
499 + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
502 * TCB structure exported to user-land via sysctl(3).
503 * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
504 * included. Not all of our clients do.
506 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
507 struct xtcpcb {
508 size_t xt_len;
509 struct inpcb xt_inp;
510 struct tcpcb xt_tp;
511 struct xsocket xt_socket;
512 u_quad_t xt_alignment_hack;
514 #endif
517 * Names for TCP sysctl objects
519 #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */
520 #define TCPCTL_DO_RFC1644 2 /* use RFC-1644 extensions */
521 #define TCPCTL_MSSDFLT 3 /* MSS default */
522 #define TCPCTL_STATS 4 /* statistics (read-only) */
523 #define TCPCTL_RTTDFLT 5 /* default RTT estimate */
524 #define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */
525 #define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */
526 #define TCPCTL_SENDSPACE 8 /* send buffer space */
527 #define TCPCTL_RECVSPACE 9 /* receive buffer space */
528 #define TCPCTL_KEEPINIT 10 /* timeout for establishing syn */
529 #define TCPCTL_PCBLIST 11 /* list of all outstanding PCBs */
530 #define TCPCTL_DELACKTIME 12 /* time before sending delayed ACK */
531 #define TCPCTL_V6MSSDFLT 13 /* MSS default for IPv6 */
532 #define TCPCTL_MAXID 14
534 #define TCPCTL_NAMES { \
535 { 0, 0 }, \
536 { "rfc1323", CTLTYPE_INT }, \
537 { "rfc1644", CTLTYPE_INT }, \
538 { "mssdflt", CTLTYPE_INT }, \
539 { "stats", CTLTYPE_STRUCT }, \
540 { "rttdflt", CTLTYPE_INT }, \
541 { "keepidle", CTLTYPE_INT }, \
542 { "keepintvl", CTLTYPE_INT }, \
543 { "sendspace", CTLTYPE_INT }, \
544 { "recvspace", CTLTYPE_INT }, \
545 { "keepinit", CTLTYPE_INT }, \
546 { "pcblist", CTLTYPE_STRUCT }, \
547 { "delacktime", CTLTYPE_INT }, \
548 { "v6mssdflt", CTLTYPE_INT }, \
551 #ifdef _KERNEL
552 #ifdef SYSCTL_DECL
553 SYSCTL_DECL(_net_inet_tcp);
554 #endif
556 #define TCP_DO_SACK(tp) ((tp)->t_flags & TF_SACK_PERMITTED)
558 TAILQ_HEAD(tcpcbackqhead,tcpcb);
560 extern struct inpcbinfo tcbinfo[];
561 extern struct tcpcbackqhead tcpcbackq[];
563 extern int tcp_mssdflt; /* XXX */
564 extern int tcp_delack_enabled;
565 extern int path_mtu_discovery;
567 int tcp_addrcpu(in_addr_t faddr, in_port_t fport,
568 in_addr_t laddr, in_port_t lport);
569 struct lwkt_port *
570 tcp_addrport(in_addr_t faddr, in_port_t fport,
571 in_addr_t laddr, in_port_t lport);
572 void tcp_canceltimers (struct tcpcb *);
573 struct tcpcb *
574 tcp_close (struct tcpcb *);
575 void tcpmsg_service_loop (void *);
576 void tcp_ctlinput (int, struct sockaddr *, void *);
577 int tcp_ctloutput (struct socket *, struct sockopt *);
578 struct lwkt_port *
579 tcp_cport(int cpu);
580 struct tcpcb *
581 tcp_drop (struct tcpcb *, int);
582 void tcp_drain (void);
583 void tcp_fasttimo (void);
584 struct rmxp_tao *
585 tcp_gettaocache (struct in_conninfo *);
586 void tcp_init (void);
587 void tcp_thread_init (void);
588 void tcp_input (struct mbuf *, ...);
589 void tcp_mss (struct tcpcb *, int);
590 int tcp_mssopt (struct tcpcb *);
591 void tcp_drop_syn_sent (struct inpcb *, int);
592 void tcp_mtudisc (struct inpcb *, int);
593 struct tcpcb *
594 tcp_newtcpcb (struct inpcb *);
595 int tcp_output (struct tcpcb *);
596 void tcp_quench (struct inpcb *, int);
597 void tcp_respond (struct tcpcb *, void *,
598 struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
599 struct rtentry *
600 tcp_rtlookup (struct in_conninfo *);
601 int tcp_sack_bytes_below(struct scoreboard *scb, tcp_seq seq);
602 void tcp_sack_cleanup(struct scoreboard *scb);
603 int tcp_sack_ndsack_blocks(struct raw_sackblock *blocks,
604 const int numblocks, tcp_seq snd_una);
605 void tcp_sack_fill_report(struct tcpcb *tp, u_char *opt, u_int *plen);
606 boolean_t
607 tcp_sack_has_sacked(struct scoreboard *scb, u_int amount);
608 void tcp_sack_init(void);
609 void tcp_sack_tcpcb_init(struct tcpcb *tp);
610 uint32_t tcp_sack_compute_pipe(struct tcpcb *tp);
611 boolean_t
612 tcp_sack_nextseg(struct tcpcb *tp, tcp_seq *nextrexmt, uint32_t *len,
613 boolean_t *losdup);
614 #ifdef later
615 void tcp_sack_revert_scoreboard(struct scoreboard *scb, tcp_seq snd_una,
616 u_int maxseg);
617 void tcp_sack_save_scoreboard(struct scoreboard *scb);
618 #endif
619 void tcp_sack_skip_sacked(struct scoreboard *scb, tcp_seq *prexmt);
620 void tcp_sack_update_scoreboard(struct tcpcb *tp, struct tcpopt *to);
621 void tcp_save_congestion_state(struct tcpcb *tp);
622 void tcp_revert_congestion_state(struct tcpcb *tp);
623 void tcp_setpersist (struct tcpcb *);
624 void tcp_slowtimo (void);
625 struct tcptemp *tcp_maketemplate (struct tcpcb *);
626 void tcp_freetemplate (struct tcptemp *);
627 void tcp_fillheaders (struct tcpcb *, void *, void *);
628 struct lwkt_port *
629 tcp_soport(struct socket *, struct sockaddr *,
630 struct mbuf **, int);
631 struct tcpcb *
632 tcp_timers (struct tcpcb *, int);
633 void tcp_trace (short, short, struct tcpcb *, void *, struct tcphdr *,
634 int);
635 void tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq);
636 void syncache_init(void);
637 void syncache_unreach(struct in_conninfo *, struct tcphdr *);
638 int syncache_expand(struct in_conninfo *, struct tcphdr *,
639 struct socket **, struct mbuf *);
640 int syncache_add(struct in_conninfo *, struct tcpopt *,
641 struct tcphdr *, struct socket **, struct mbuf *);
642 void syncache_chkrst(struct in_conninfo *, struct tcphdr *);
643 void syncache_badack(struct in_conninfo *);
645 extern struct pr_usrreqs tcp_usrreqs;
646 extern u_long tcp_sendspace;
647 extern u_long tcp_recvspace;
648 tcp_seq tcp_new_isn (struct tcpcb *);
650 #endif /* _KERNEL */
652 #endif /* _NETINET_TCP_VAR_H_ */