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
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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 1.42 2008/10/27 02:56:30 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 */
77 #ifndef _NETINET_TCP_H_
78 #include <netinet/tcp.h>
82 * Kernel variables for tcp.
84 extern int tcp_do_rfc1323;
85 extern int tcp_low_rtobase;
86 extern int tcp_do_sack;
87 extern int tcp_do_smartsack;
88 extern int tcp_do_rescuesack;
89 extern int tcp_aggressive_rescuesack;
90 extern int tcp_do_rfc3517bis;
91 extern int tcp_rfc3517bis_rxt;
92 extern int tcp_aggregate_acks;
93 extern int tcp_eifel_rtoinc;
95 /* TCP segment queue entry */
97 TAILQ_ENTRY(tseg_qent) tqe_q;
98 int tqe_len; /* TCP segment data length */
99 struct tcphdr *tqe_th; /* a pointer to tcp header */
100 struct mbuf *tqe_m; /* mbuf contains packet */
102 TAILQ_HEAD(tsegqe_head, tseg_qent);
103 extern int tcp_reass_maxseg;
104 extern int tcp_reass_qsize;
105 #ifdef MALLOC_DECLARE
106 MALLOC_DECLARE(M_TSEGQ);
110 u_char tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
114 #define tcp6cb tcpcb /* for KAME src sync over BSD*'s */
116 struct raw_sackblock { /* covers [start, end) */
121 /* maximum number of SACK blocks that will fit in the TCP option space */
122 #define MAX_SACK_REPORT_BLOCKS 4
124 TAILQ_HEAD(sackblock_list, sackblock);
128 struct sackblock_list sackblocks;
129 tcp_seq lostseq; /* passed SACK lost test */
130 struct sackblock *lastfound; /* search hint */
131 struct sackblock *freecache; /* one slot free block cache */
134 struct netmsg_tcp_timer;
137 * Tcp control block, one per tcp; fields:
138 * Organized for 16 byte cacheline efficiency.
141 struct tsegqe_head t_segq;
142 int t_dupacks; /* consecutive dup acks recd */
143 int t_rxtthresh; /* # dup acks to start fast rxt */
144 int tt_cpu; /* sanity check the cpu */
146 struct tcp_callout *tt_rexmt; /* retransmit timer */
147 struct tcp_callout *tt_persist;/* retransmit persistence */
148 struct tcp_callout *tt_keep; /* keepalive */
149 struct tcp_callout *tt_2msl; /* 2*msl TIME_WAIT timer */
150 struct tcp_callout *tt_delack; /* delayed ACK timer */
151 struct netmsg_tcp_timer *tt_msg; /* timer message */
153 struct inpcb *t_inpcb; /* back pointer to internet pcb */
154 int t_state; /* state of this connection */
156 #define TF_ACKNOW 0x00000001 /* ack peer immediately */
157 #define TF_DELACK 0x00000002 /* ack, but try to delay it */
158 #define TF_NODELAY 0x00000004 /* don't delay packets to coalesce */
159 #define TF_NOOPT 0x00000008 /* don't use tcp options */
160 #define TF_SENTFIN 0x00000010 /* have sent FIN */
161 #define TF_REQ_SCALE 0x00000020 /* have/will request window scaling */
162 #define TF_RCVD_SCALE 0x00000040 /* other side has requested scaling */
163 #define TF_REQ_TSTMP 0x00000080 /* have/will request timestamps */
164 #define TF_RCVD_TSTMP 0x00000100 /* a timestamp was received in SYN */
165 #define TF_SACK_PERMITTED 0x00000200 /* other side said I could SACK */
166 #define TF_NEEDSYN 0x00000400 /* send SYN (implicit state) */
167 #define TF_NEEDFIN 0x00000800 /* send FIN (implicit state) */
168 #define TF_NOPUSH 0x00001000 /* don't push */
169 #define TF_LISTEN 0x00002000 /* listen(2) has been called */
170 #define TF_SIGNATURE 0x00004000 /* require MD5 digests (RFC2385) */
171 #define TF_NCR 0x00008000 /* Non-Congestion Robustness RFC4653 */
172 #define TF_MORETOCOME 0x00010000 /* More data to be appended to sock */
173 #define TF_UNUSED005 0x00020000
174 #define TF_LASTIDLE 0x00040000 /* connection was previously idle */
175 #define TF_RXWIN0SENT 0x00080000 /* sent a receiver win 0 in response */
176 #define TF_FASTRECOVERY 0x00100000 /* in NewReno Fast Recovery */
177 #define TF_UNUSED006 0x00200000
178 #define TF_UNUSED007 0x00400000
179 #define TF_UNUSED008 0x00800000
180 #define TF_UNUSED009 0x01000000
181 #define TF_FORCE 0x02000000 /* Set if forcing out a byte */
182 #define TF_ONOUTPUTQ 0x04000000 /* on t_outputq list */
183 #define TF_UNUSED002 0x08000000
184 #define TF_UNUSED003 0x10000000
185 #define TF_UNUSED004 0x20000000
186 #define TF_KEEPALIVE 0x40000000 /* temporary keepalive */
187 #define TF_RXRESIZED 0x80000000 /* rcvbuf was resized */
188 tcp_seq snd_up; /* send urgent pointer */
189 u_long snd_last; /* time last data were sent */
191 tcp_seq snd_una; /* send unacknowledged */
192 tcp_seq snd_recover; /* for use with NewReno Fast Recovery */
193 tcp_seq snd_max; /* highest sequence number sent;
194 * used to recognize retransmits */
195 tcp_seq snd_nxt; /* send next */
197 tcp_seq snd_wl1; /* window update seg seq number */
198 tcp_seq snd_wl2; /* window update seg ack number */
199 tcp_seq iss; /* initial send sequence number */
200 tcp_seq irs; /* initial receive sequence number */
202 tcp_seq rcv_nxt; /* receive next */
203 tcp_seq rcv_adv; /* advertised window */
204 u_long rcv_wnd; /* receive window */
205 tcp_seq rcv_up; /* receive urgent pointer */
207 u_long snd_wnd; /* send window */
208 u_long snd_cwnd; /* congestion-controlled window */
209 u_long snd_wacked; /* bytes acked in one send window */
210 u_long snd_ssthresh; /* snd_cwnd size threshold for
211 * for slow start exponential to
214 int t_rxtcur; /* current retransmit value (ticks) */
215 u_int t_maxseg; /* maximum segment size */
216 int t_srtt; /* smoothed round-trip time */
217 int t_rttvar; /* variance in round-trip time */
219 u_int t_maxopd; /* mss plus options */
221 u_long t_rcvtime; /* reception inactivity time */
222 u_long t_starttime; /* time connection was established */
223 int t_rtttime; /* round trip time */
224 tcp_seq t_rtseq; /* sequence number being timed */
226 int t_rxtshift; /* log(2) of rexmt exp. backoff */
227 u_int t_rttmin; /* minimum rtt allowed */
228 u_int t_rttbest; /* best rtt we've seen */
229 u_long t_rttupdated; /* number of times rtt sampled */
230 u_long max_sndwnd; /* largest window peer has offered */
232 int t_softerror; /* possible error not yet reported */
233 /* out-of-band data */
234 char t_oobflags; /* have some */
235 char t_iobc; /* input character */
236 #define TCPOOB_HAVEDATA 0x01
237 #define TCPOOB_HADDATA 0x02
239 /* RFC 1323 variables */
240 u_char snd_scale; /* window scaling for send window */
241 u_char rcv_scale; /* window scaling for recv window */
242 u_char request_r_scale; /* pending window scaling */
243 u_long ts_recent; /* timestamp echo data */
245 u_long ts_recent_age; /* when last updated */
246 tcp_seq last_ack_sent;
250 #define TRXT_F_REBASERTO 0x0001 /* Recalculate RTO based on new RTT */
251 #define TRXT_F_WASFRECOVERY 0x0002 /* was in NewReno Fast Recovery */
252 #define TRXT_F_FIRSTACCACK 0x0004 /* Look for 1st acceptable ACK. */
253 #define TRXT_F_FASTREXMT 0x0008 /* Did Fast Retransmit. */
254 #define TRXT_F_EARLYREXMT 0x0010 /* Did Early (Fast) Retransmit. */
255 int t_srtt_prev; /* adjusted SRTT prior to retransmit */
256 int t_rttvar_prev; /* RTTVAR prior to retransmit */
257 int t_rxtcur_prev; /* rexmt timeout prior to retransmit */
258 tcp_seq snd_max_prev; /* SND_MAX prior to retransmit */
259 u_long snd_cwnd_prev; /* cwnd prior to retransmit */
260 u_long snd_wacked_prev; /* prior bytes acked in send window */
261 u_long snd_ssthresh_prev; /* ssthresh prior to retransmit */
262 tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */
263 u_long t_badrxtwin; /* window for retransmit recovery */
264 u_long t_rexmtTS; /* timestamp of last retransmit */
265 u_char snd_limited; /* segments limited transmitted */
268 #define TSACK_F_SACKRESCUED 0x0001 /* sent rescue SACK recovery data */
269 #define TSACK_F_DUPSEG 0x0002 /* last seg a duplicate */
270 #define TSACK_F_ENCLOSESEG 0x0004 /* enclosing SACK block */
271 #define TSACK_F_SACKLEFT 0x0008 /* send SACK blocks from left side */
272 tcp_seq rexmt_high; /* highest seq # retransmitted + 1 */
273 tcp_seq rexmt_rescue; /* rescue SACKED sequence number */
274 tcp_seq snd_max_rexmt; /* snd_max when rexmting snd_una */
275 struct scoreboard scb; /* sack scoreboard */
276 struct raw_sackblock reportblk; /* incoming segment or D-SACK block */
277 struct raw_sackblock encloseblk;
279 struct raw_sackblock sackhistory[MAX_SACK_REPORT_BLOCKS]; /* reported */
281 TAILQ_ENTRY(tcpcb) t_outputq; /* tcp_output needed list */
283 /* bandwith limitation */
284 u_long snd_bandwidth; /* calculated bandwidth or 0 */
285 u_long snd_bwnd; /* bandwidth-controlled window */
286 int t_bw_rtttime; /* used for bandwidth calculation */
287 tcp_seq t_bw_rtseq; /* used for bandwidth calculation */
289 /* anti DoS counters */
290 u_long rcv_second; /* start of interval second */
291 u_long rcv_pps; /* received packets per second */
292 u_long rcv_byps; /* received bytes per second */
294 u_int32_t rfbuf_ts; /* recv buffer autoscaling timestamp */
295 int rfbuf_cnt; /* recv buffer autoscaling byte count */
297 int t_keepinit; /* time to establish connection */
299 int t_keepidle; /* time before keepalive probes begin */
300 int t_keepintvl; /* time between keepalive probes */
301 int t_keepcnt; /* maximum number of keepalive probes */
302 int t_maxidle; /* time to drop after starting probes */
304 int t_rxtsyn; /* time spent in SYN or SYN|ACK rexmt */
307 #define IN_FASTRECOVERY(tp) (tp->t_flags & TF_FASTRECOVERY)
308 #define ENTER_FASTRECOVERY(tp) tp->t_flags |= TF_FASTRECOVERY
309 #define EXIT_FASTRECOVERY(tp) tp->t_flags &= ~TF_FASTRECOVERY
313 * Defines which are needed by the xform_tcp module and tcp_[in|out]put
314 * for SADB verification and lookup.
316 #define TCP_SIGLEN 16 /* length of computed digest in bytes */
317 #define TCP_KEYLEN_MIN 1 /* minimum length of TCP-MD5 key */
318 #define TCP_KEYLEN_MAX 80 /* maximum length of TCP-MD5 key */
320 * Only a single SA per host may be specified at this time. An SPI is
321 * needed in order for the KEY_ALLOCSA() lookup to work.
323 #define TCP_SIG_SPI 0x1000
324 #endif /* TCP_SIGNATURE */
330 u_long tcps_connattempt; /* connections initiated */
331 u_long tcps_accepts; /* connections accepted */
332 u_long tcps_connects; /* connections established */
333 u_long tcps_drops; /* connections dropped */
334 u_long tcps_conndrops; /* embryonic connections dropped */
335 u_long tcps_minmssdrops; /* average minmss too low drops */
336 u_long tcps_closed; /* conn. closed (includes drops) */
337 u_long tcps_segstimed; /* segs where we tried to get rtt */
338 u_long tcps_rttupdated; /* times we succeeded */
339 u_long tcps_delack; /* delayed acks sent */
340 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
341 u_long tcps_rexmttimeo; /* retransmit timeouts */
342 u_long tcps_persisttimeo; /* persist timeouts */
343 u_long tcps_keeptimeo; /* keepalive timeouts */
344 u_long tcps_keepprobe; /* keepalive probes sent */
345 u_long tcps_keepdrops; /* connections dropped in keepalive */
347 u_long tcps_sndtotal; /* total packets sent */
348 u_long tcps_sndpack; /* data packets sent */
349 u_long tcps_sndbyte; /* data bytes sent */
350 u_long tcps_sndrexmitpack; /* data packets retransmitted */
351 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
352 u_long tcps_sndsackrtopack; /* packets sent by SACK after RTO */
353 u_long tcps_sndsackrtobyte; /* bytes sent by SACK after RTO */
354 u_long tcps_sndfastrexmit; /* Fast Retransmissions */
355 u_long tcps_sndearlyrexmit; /* early Fast Retransmissions */
356 u_long tcps_sndlimited; /* Limited Transmit packets */
357 u_long tcps_sndrtobad; /* spurious RTO retransmissions */
358 u_long tcps_sndfastrexmitbad; /* spurious Fast Retransmissions */
359 u_long tcps_sndearlyrexmitbad; /* spurious early Fast Retransmissions,
360 a subset of tcps_sndfastrexmitbad */
361 u_long tcps_eifeldetected; /* Eifel-detected spurious rexmits */
362 u_long tcps_rttcantdetect; /* Eifel but not 1/2 RTT-detectable */
363 u_long tcps_rttdetected; /* RTT-detected spurious RTO rexmits */
364 u_long tcps_sndacks; /* ack-only packets sent */
365 u_long tcps_sndprobe; /* window probes sent */
366 u_long tcps_sndurg; /* packets sent with URG only */
367 u_long tcps_sndwinup; /* window update-only packets sent */
368 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
369 u_long tcps_sndsackpack; /* packets sent by SACK recovery alg */
370 u_long tcps_sndsackbyte; /* bytes sent by SACK recovery */
371 u_long tcps_snduna3; /* re-retransmit snd_una on 3 new seg */
372 u_long tcps_snduna1; /* re-retransmit snd_una on 1 new seg */
373 u_long tcps_sndsackopt; /* SACK options sent */
374 u_long tcps_snddsackopt; /* D-SACK options sent */
375 u_long tcps_sndidle; /* sending idle detected */
376 u_long tcps_sackrescue; /* SACK rescue data packets sent */
377 u_long tcps_sackrescue_try; /* SACK rescues attempted */
378 u_long tcps_eifelresponse; /* Eifel responses */
380 u_long tcps_rcvtotal; /* total packets received */
381 u_long tcps_rcvpack; /* packets received in sequence */
382 u_long tcps_rcvbyte; /* bytes received in sequence */
383 u_long tcps_rcvbadsum; /* packets received with ccksum errs */
384 u_long tcps_rcvbadoff; /* packets received with bad offset */
385 u_long tcps_rcvmemdrop; /* packets dropped for lack of memory */
386 u_long tcps_rcvshort; /* packets received too short */
387 u_long tcps_rcvduppack; /* duplicate-only packets received */
388 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
389 u_long tcps_rcvpartduppack; /* packets with some duplicate data */
390 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
391 u_long tcps_rcvoopack; /* out-of-order packets received */
392 u_long tcps_rcvoobyte; /* out-of-order bytes received */
393 u_long tcps_rcvpackafterwin; /* packets with data after window */
394 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
395 u_long tcps_rcvafterclose; /* packets rcvd after "close" */
396 u_long tcps_rcvwinprobe; /* rcvd window probe packets */
397 u_long tcps_rcvdupack; /* rcvd duplicate acks */
398 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
399 u_long tcps_rcvackpack; /* rcvd ack packets */
400 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
401 u_long tcps_rcvwinupd; /* rcvd window update packets */
402 u_long tcps_pawsdrop; /* segments dropped due to PAWS */
403 u_long tcps_pawsaccept; /* segments accepted, PAWS tolerance */
404 u_long tcps_predack; /* times hdr predict ok for acks */
405 u_long tcps_preddat; /* times hdr predict ok for data pkts */
406 u_long tcps_pcbcachemiss;
407 u_long tcps_cachedrtt; /* times cached RTT in route updated */
408 u_long tcps_cachedrttvar; /* times cached rttvar updated */
409 u_long tcps_cachedssthresh; /* times cached ssthresh updated */
410 u_long tcps_usedrtt; /* times RTT initialized from route */
411 u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */
412 u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/
413 u_long tcps_persistdrop; /* timeout in persist state */
414 u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
415 u_long tcps_mturesent; /* resends due to MTU discovery */
416 u_long tcps_listendrop; /* listen queue overflows */
417 u_long tcps_rcvbadsackopt; /* rcvd illegal SACK options */
419 u_long tcps_sacksbupdate; /* times SACK scoreboard updated */
420 u_long tcps_sacksboverflow; /* times SACK scoreboard overflowed */
421 u_long tcps_sacksbreused; /* times SACK sb-block reused */
422 u_long tcps_sacksbfailed; /* times SACK sb update failed */
423 u_long tcps_sacksbfast; /* timee SACK sb-block uses cache */
425 u_long tcps_sc_added; /* entry added to syncache */
426 u_long tcps_sc_retransmitted; /* syncache entry was retransmitted */
427 u_long tcps_sc_dupsyn; /* duplicate SYN packet */
428 u_long tcps_sc_dropped; /* could not reply to packet */
429 u_long tcps_sc_completed; /* successful extraction of entry */
430 u_long tcps_sc_bucketoverflow; /* syncache per-bucket limit hit */
431 u_long tcps_sc_cacheoverflow; /* syncache cache limit hit */
432 u_long tcps_sc_reset; /* RST removed entry from syncache */
433 u_long tcps_sc_stale; /* timed out or listen socket gone */
434 u_long tcps_sc_aborted; /* syncache entry aborted */
435 u_long tcps_sc_badack; /* removed due to bad ACK */
436 u_long tcps_sc_unreach; /* ICMP unreachable received */
437 u_long tcps_sc_zonefail; /* zalloc() failed */
438 u_long tcps_sc_sendcookie; /* SYN cookie sent */
439 u_long tcps_sc_recvcookie; /* SYN cookie received */
445 #define tcpstat tcpstats_percpu[mycpuid]
447 #define tcpstat tcpstats_percpu[0]
452 extern struct tcp_stats tcpstats_percpu[MAXCPU];
454 static const int tcprexmtthresh = 3;
458 * Structure to hold TCP options that are only used during segment
459 * processing (in tcp_input), but not held in the tcpcb.
460 * It's basically used to reduce the number of parameters
464 u_long to_flags; /* which options are present */
465 #define TOF_TS 0x0001 /* timestamp */
466 #define TOF_MSS 0x0010
467 #define TOF_SCALE 0x0020
468 #define TOF_SACK_PERMITTED 0x0040
469 #define TOF_SACK 0x0080
470 #define TOF_SIGNATURE 0x0100 /* signature option present */
471 #define TOF_SIGLEN 0x0200 /* signature length valid (RFC2385) */
472 #define TOF_DSACK 0x0400 /* D-SACK */
473 #define TOF_SACK_REDUNDANT 0x0800 /* all SACK blocks are known */
477 u_int8_t to_requested_s_scale;
478 u_int8_t to_nsackblocks;
479 struct raw_sackblock *to_sackblocks;
483 inp_gen_t sc_inp_gencnt; /* pointer check */
484 struct tcpcb *sc_tp; /* tcb for listening socket */
485 struct mbuf *sc_ipopts; /* source route */
486 struct in_conninfo sc_inc; /* addresses */
487 #define sc_route sc_inc.inc_route
488 #define sc_route6 sc_inc.inc6_route
489 u_int32_t sc_tsrecent;
490 tcp_seq sc_irs; /* seq from peer */
491 tcp_seq sc_iss; /* our ISS */
492 u_long sc_rxttime; /* retransmit time */
493 u_int16_t sc_rxtslot; /* retransmit counter */
494 u_int16_t sc_peer_mss; /* peer's MSS */
495 u_int16_t sc_wnd; /* advertised window */
496 u_int8_t sc_requested_s_scale:4,
497 sc_request_r_scale:4;
499 #define SCF_NOOPT 0x01 /* no TCP options */
500 #define SCF_WINSCALE 0x02 /* negotiated window scaling */
501 #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */
502 #define SCF_UNUSED 0x08 /* unused */
503 #define SCF_UNREACH 0x10 /* icmp unreachable received */
504 #define SCF_SACK_PERMITTED 0x20 /* saw SACK permitted option */
505 #define SCF_SIGNATURE 0x40 /* send MD5 digests */
506 #define SCF_MARKER 0x80 /* not a real entry */
507 int sc_rxtused; /* time spent in SYN|ACK rxt */
508 u_long sc_sndwnd; /* send window */
509 TAILQ_ENTRY(syncache) sc_hash;
510 TAILQ_ENTRY(syncache) sc_timerq;
513 struct syncache_head {
514 TAILQ_HEAD(, syncache) sch_bucket;
518 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
519 #define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
522 * The smoothed round-trip time and estimated variance
523 * are stored as fixed point numbers scaled by the values below.
524 * For convenience, these scales are also used in smoothing the average
525 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
526 * With these scales, srtt has 3 bits to the right of the binary point,
527 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
528 * binary point, and is smoothed with an ALPHA of 0.75.
530 #define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */
531 #define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */
532 #define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */
533 #define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */
534 #define TCP_DELTA_SHIFT 2 /* see tcp_input.c */
537 * The initial retransmission should happen at rtt + 4 * rttvar.
538 * Because of the way we do the smoothing, srtt and rttvar
539 * will each average +1/2 tick of bias. When we compute
540 * the retransmit timer, we want 1/2 tick of rounding and
541 * 1 extra tick because of +-1/2 tick uncertainty in the
542 * firing of the timer. The bias will give us exactly the
543 * 1.5 tick we need. But, because the bias is
544 * statistical, we have to test that we don't drop below
545 * the minimum feasible timer (which is 2 ticks).
546 * This version of the macro adapted from a paper by Lawrence
547 * Brakmo and Larry Peterson which outlines a problem caused
548 * by insufficient precision in the original implementation,
549 * which results in inappropriately large RTO values for very
552 #define TCP_REXMTVAL(tp) \
553 max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \
554 + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
557 * TCB structure exported to user-land via sysctl(3).
558 * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
559 * included. Not all of our clients do.
561 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
566 struct xsocket xt_socket;
567 u_quad_t xt_alignment_hack;
572 * Names for TCP sysctl objects
574 #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */
575 /* 2 was TCPCTL_DO_RFC1644 */
576 #define TCPCTL_MSSDFLT 3 /* MSS default */
577 #define TCPCTL_STATS 4 /* statistics (read-only) */
578 #define TCPCTL_RTTDFLT 5 /* default RTT estimate */
579 #define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */
580 #define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */
581 #define TCPCTL_SENDSPACE 8 /* send buffer space */
582 #define TCPCTL_RECVSPACE 9 /* receive buffer space */
583 #define TCPCTL_KEEPINIT 10 /* timeout for establishing syn */
584 #define TCPCTL_PCBLIST 11 /* list of all outstanding PCBs */
585 #define TCPCTL_DELACKTIME 12 /* time before sending delayed ACK */
586 #define TCPCTL_V6MSSDFLT 13 /* MSS default for IPv6 */
587 #define TCPCTL_MAXID 14
589 #define TCPCTL_NAMES { \
591 { "rfc1323", CTLTYPE_INT }, \
592 { "reserved", CTLTYPE_INT}, /* was rfc1644 */ \
593 { "mssdflt", CTLTYPE_INT }, \
594 { "stats", CTLTYPE_STRUCT }, \
595 { "rttdflt", CTLTYPE_INT }, \
596 { "keepidle", CTLTYPE_INT }, \
597 { "keepintvl", CTLTYPE_INT }, \
598 { "sendspace", CTLTYPE_INT }, \
599 { "recvspace", CTLTYPE_INT }, \
600 { "keepinit", CTLTYPE_INT }, \
601 { "pcblist", CTLTYPE_STRUCT }, \
602 { "delacktime", CTLTYPE_INT }, \
603 { "v6mssdflt", CTLTYPE_INT }, \
608 SYSCTL_DECL(_net_inet_tcp);
611 #define TCP_DO_SACK(tp) ((tp)->t_flags & TF_SACK_PERMITTED)
612 #define TCP_DO_NCR(tp) (((tp)->t_flags & TF_NCR) && TCP_DO_SACK((tp)))
613 #define TCP_SACK_BLKEND(len, thflags) \
614 ((len) + (((thflags) & TH_FIN) != 0))
616 TAILQ_HEAD(tcpcbackqhead,tcpcb);
618 extern struct inpcbinfo tcbinfo[];
619 extern struct tcpcbackqhead tcpcbackq[];
621 extern int tcp_mssdflt; /* XXX */
622 extern int tcp_minmss;
623 extern int tcp_delack_enabled;
624 extern int path_mtu_discovery;
628 int tcp_addrcpu(in_addr_t faddr, in_port_t fport,
629 in_addr_t laddr, in_port_t lport);
631 tcp_addrport(in_addr_t faddr, in_port_t fport,
632 in_addr_t laddr, in_port_t lport);
633 struct lwkt_port *tcp_addrport0(void);
634 void tcp_canceltimers (struct tcpcb *);
636 tcp_close (struct tcpcb *);
637 void tcp_ctlinput(union netmsg *);
638 void tcp_ctloutput(union netmsg *);
640 tcp_drop (struct tcpcb *, int);
641 void tcp_drain (void);
642 void tcp_fasttimo (void);
643 void tcp_init (void);
644 void tcp_thread_init (void);
645 int tcp_input (struct mbuf **, int *, int);
646 void tcp_mss (struct tcpcb *, int);
647 int tcp_mssopt (struct tcpcb *);
648 void tcp_drop_syn_sent (struct inpcb *, int);
649 void tcp_mtudisc (struct inpcb *, int);
651 tcp_newtcpcb (struct inpcb *);
652 int tcp_output (struct tcpcb *);
653 void tcp_quench (struct inpcb *, int);
654 void tcp_respond (struct tcpcb *, void *,
655 struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
657 tcp_rtlookup (struct in_conninfo *);
658 int tcp_sack_bytes_below(struct scoreboard *scb, tcp_seq seq);
659 void tcp_sack_destroy(struct scoreboard *scb);
660 void tcp_sack_cleanup(struct scoreboard *scb);
661 void tcp_sack_report_cleanup(struct tcpcb *tp);
662 int tcp_sack_ndsack_blocks(struct raw_sackblock *blocks,
663 const int numblocks, tcp_seq snd_una);
664 void tcp_sack_fill_report(struct tcpcb *tp, u_char *opt, u_int *plen);
666 tcp_sack_has_sacked(struct scoreboard *scb, u_int amount);
667 void tcp_sack_tcpcb_init(struct tcpcb *tp);
668 uint32_t tcp_sack_compute_pipe(struct tcpcb *tp);
670 tcp_sack_nextseg(struct tcpcb *tp, tcp_seq *nextrexmt, uint32_t *len,
673 tcp_sack_islost(struct scoreboard *scb, tcp_seq seq);
674 void tcp_sack_update_lostseq(struct scoreboard *scb, tcp_seq snd_una,
675 u_int maxseg, int rxtthresh);
677 void tcp_sack_revert_scoreboard(struct scoreboard *scb, tcp_seq snd_una,
679 void tcp_sack_save_scoreboard(struct scoreboard *scb);
681 void tcp_sack_skip_sacked(struct scoreboard *scb, tcp_seq *prexmt);
682 void tcp_sack_update_scoreboard(struct tcpcb *tp, struct tcpopt *to);
683 void tcp_save_congestion_state(struct tcpcb *tp);
684 void tcp_revert_congestion_state(struct tcpcb *tp);
685 void tcp_setpersist (struct tcpcb *);
686 struct tcptemp *tcp_maketemplate (struct tcpcb *);
687 void tcp_freetemplate (struct tcptemp *);
688 void tcp_fillheaders (struct tcpcb *, void *, void *);
690 tcp_soport(struct socket *, struct sockaddr *, struct mbuf **);
692 tcp_ctlport(int, struct sockaddr *, void *);
694 tcp_timers (struct tcpcb *, int);
695 void tcp_trace (short, short, struct tcpcb *, void *, struct tcphdr *,
697 void tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq);
698 u_long tcp_initial_window(struct tcpcb *tp);
699 void tcp_timer_keep_activity(struct tcpcb *tp, int thflags);
700 void syncache_init(void);
701 void syncache_unreach(struct in_conninfo *, struct tcphdr *);
702 int syncache_expand(struct in_conninfo *, struct tcphdr *,
703 struct socket **, struct mbuf *);
704 int syncache_add(struct in_conninfo *, struct tcpopt *,
705 struct tcphdr *, struct socket *, struct mbuf *);
706 void syncache_chkrst(struct in_conninfo *, struct tcphdr *);
707 void syncache_badack(struct in_conninfo *);
708 void syncache_destroy(struct tcpcb *tp);
711 int tcpsignature_apply(void *fstate, void *data, unsigned int len);
712 int tcpsignature_compute(struct mbuf *m, int len, int tcpoptlen,
713 u_char *buf, u_int direction);
714 #endif /* TCP_SIGNATURE */
716 extern struct pr_usrreqs tcp_usrreqs;
717 extern u_long tcp_sendspace;
718 extern u_long tcp_recvspace;
719 tcp_seq tcp_new_isn (struct tcpcb *);
723 #endif /* _NETINET_TCP_VAR_H_ */