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 $
70 #ifndef _NETINET_TCP_VAR_H_
71 #define _NETINET_TCP_VAR_H_
73 #ifndef _NETINET_IN_PCB_H_
74 #include <netinet/in_pcb.h> /* needed for in_conninfo, inp_gen_t */
76 #ifndef _NETINET_TCP_H_
77 #include <netinet/tcp.h>
81 * Kernel variables for tcp.
83 extern int tcp_do_rfc1323;
84 extern int tcp_low_rtobase;
85 extern int tcp_do_sack;
86 extern int tcp_do_smartsack;
87 extern int tcp_do_rescuesack;
88 extern int tcp_aggressive_rescuesack;
89 extern int tcp_do_rfc6675;
90 extern int tcp_rfc6675_rxt;
91 extern int tcp_aggregate_acks;
92 extern int tcp_eifel_rtoinc;
93 extern int tcp_prio_synack;
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;
138 * Tcp control block, one per tcp; fields:
139 * Organized for 16 byte cacheline efficiency.
142 struct tsegqe_head t_segq;
143 int t_dupacks; /* consecutive dup acks recd */
144 int t_rxtthresh; /* # dup acks to start fast rxt */
145 int tt_cpu; /* sanity check the cpu */
147 struct tcp_callout *tt_rexmt; /* retransmit timer */
148 struct tcp_callout *tt_persist;/* retransmit persistence */
149 struct tcp_callout *tt_keep; /* keepalive */
150 struct tcp_callout *tt_2msl; /* 2*msl TIME_WAIT timer */
151 struct tcp_callout *tt_delack; /* delayed ACK timer */
152 struct netmsg_tcp_timer *tt_msg; /* timer message */
154 struct netmsg_base *tt_sndmore;/* send more segments (fairsend) */
156 struct inpcb *t_inpcb; /* back pointer to internet pcb */
157 int t_state; /* state of this connection */
159 #define TF_ACKNOW 0x00000001 /* ack peer immediately */
160 #define TF_DELACK 0x00000002 /* ack, but try to delay it */
161 #define TF_NODELAY 0x00000004 /* don't delay packets to coalesce */
162 #define TF_NOOPT 0x00000008 /* don't use tcp options */
163 #define TF_SENTFIN 0x00000010 /* have sent FIN */
164 #define TF_REQ_SCALE 0x00000020 /* have/will request window scaling */
165 #define TF_RCVD_SCALE 0x00000040 /* other side has requested scaling */
166 #define TF_REQ_TSTMP 0x00000080 /* have/will request timestamps */
167 #define TF_RCVD_TSTMP 0x00000100 /* a timestamp was received in SYN */
168 #define TF_SACK_PERMITTED 0x00000200 /* other side said I could SACK */
169 #define TF_NEEDSYN 0x00000400 /* send SYN (implicit state) */
170 #define TF_NEEDFIN 0x00000800 /* send FIN (implicit state) */
171 #define TF_NOPUSH 0x00001000 /* don't push */
172 #define TF_LISTEN 0x00002000 /* listen(2) has been called */
173 #define TF_SIGNATURE 0x00004000 /* require MD5 digests (RFC2385) */
174 #define TF_NCR 0x00008000 /* Non-Congestion Robustness RFC4653 */
175 #define TF_MORETOCOME 0x00010000 /* More data to be appended to sock */
176 #define TF_SAWFIN 0x00020000 /* FIN has been seen */
177 #define TF_LASTIDLE 0x00040000 /* connection was previously idle */
178 #define TF_RXWIN0SENT 0x00080000 /* sent a receiver win 0 in response */
179 #define TF_FASTRECOVERY 0x00100000 /* in Fast Recovery */
180 #define TF_QUEDFIN 0x00200000 /* FIN has been received */
181 #define TF_XMITNOW 0x00400000 /* Temporarily override Nagle */
182 #define TF_UNUSED008 0x00800000
183 #define TF_UNUSED009 0x01000000
184 #define TF_FORCE 0x02000000 /* Set if forcing out a byte */
185 #define TF_ONOUTPUTQ 0x04000000 /* on t_outputq list */
186 #define TF_FAIRSEND 0x08000000 /* fairsend is requested */
187 #define TF_UNUSED003 0x10000000
188 #define TF_UNUSED004 0x20000000
189 #define TF_KEEPALIVE 0x40000000 /* temporary keepalive */
190 #define TF_RXRESIZED 0x80000000 /* rcvbuf was resized */
191 tcp_seq snd_up; /* send urgent pointer */
192 u_long snd_last; /* time last data were sent */
194 tcp_seq snd_una; /* send unacknowledged */
195 tcp_seq snd_recover; /* for use with Fast Recovery */
196 tcp_seq snd_max; /* highest sequence number sent;
197 * used to recognize retransmits */
198 tcp_seq snd_nxt; /* send next */
200 tcp_seq snd_wl1; /* window update seg seq number */
201 tcp_seq snd_wl2; /* window update seg ack number */
202 tcp_seq iss; /* initial send sequence number */
203 tcp_seq irs; /* initial receive sequence number */
205 tcp_seq rcv_nxt; /* receive next */
206 tcp_seq rcv_adv; /* advertised window */
207 u_long rcv_wnd; /* receive window */
208 tcp_seq rcv_up; /* receive urgent pointer */
210 u_long snd_wnd; /* send window */
211 u_long snd_cwnd; /* congestion-controlled window */
212 u_long snd_wacked; /* bytes acked in one send window */
213 u_long snd_ssthresh; /* snd_cwnd size threshold for
214 * for slow start exponential to
217 int t_rxtcur; /* current retransmit value (ticks) */
218 u_int t_maxseg; /* maximum segment size */
219 int t_srtt; /* smoothed round-trip time */
220 int t_rttvar; /* variance in round-trip time */
222 u_int t_maxopd; /* mss plus options */
224 u_long t_rcvtime; /* reception inactivity time */
225 u_long t_starttime; /* time connection was established */
226 int t_rtttime; /* round trip time */
227 tcp_seq t_rtseq; /* sequence number being timed */
229 int t_rxtshift; /* log(2) of rexmt exp. backoff */
230 u_int t_rttmin; /* minimum rtt allowed */
231 u_int t_rttbest; /* best rtt we've seen */
232 u_long t_rttupdated; /* number of times rtt sampled */
233 u_long max_sndwnd; /* largest window peer has offered */
235 int t_softerror; /* possible error not yet reported */
236 /* out-of-band data */
237 char t_oobflags; /* have some */
238 char t_iobc; /* input character */
239 #define TCPOOB_HAVEDATA 0x01
240 #define TCPOOB_HADDATA 0x02
242 /* RFC 1323 variables */
243 u_char snd_scale; /* window scaling for send window */
244 u_char rcv_scale; /* window scaling for recv window */
245 u_char request_r_scale; /* pending window scaling */
246 u_long ts_recent; /* timestamp echo data */
248 u_long ts_recent_age; /* when last updated */
249 tcp_seq last_ack_sent;
253 #define TRXT_F_REBASERTO 0x0001 /* Recalculate RTO based on new RTT */
254 #define TRXT_F_WASFRECOVERY 0x0002 /* was in Fast Recovery */
255 #define TRXT_F_FIRSTACCACK 0x0004 /* Look for 1st acceptable ACK. */
256 #define TRXT_F_FASTREXMT 0x0008 /* Did Fast Retransmit. */
257 #define TRXT_F_EARLYREXMT 0x0010 /* Did Early (Fast) Retransmit. */
258 int t_srtt_prev; /* adjusted SRTT prior to retransmit */
259 int t_rttvar_prev; /* RTTVAR prior to retransmit */
260 int t_rxtcur_prev; /* rexmt timeout prior to retransmit */
261 tcp_seq snd_max_prev; /* SND_MAX prior to retransmit */
262 u_long snd_cwnd_prev; /* cwnd prior to retransmit */
263 u_long snd_wacked_prev; /* prior bytes acked in send window */
264 u_long snd_ssthresh_prev; /* ssthresh prior to retransmit */
265 tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */
266 u_long t_badrxtwin; /* window for retransmit recovery */
267 u_long t_rexmtTS; /* timestamp of last retransmit */
268 u_char snd_limited; /* segments limited transmitted */
271 #define TSACK_F_SACKRESCUED 0x0001 /* sent rescue SACK recovery data */
272 #define TSACK_F_DUPSEG 0x0002 /* last seg a duplicate */
273 #define TSACK_F_ENCLOSESEG 0x0004 /* enclosing SACK block */
274 #define TSACK_F_SACKLEFT 0x0008 /* send SACK blocks from left side */
275 tcp_seq rexmt_high; /* highest seq # retransmitted + 1 */
276 tcp_seq rexmt_rescue; /* rescue SACKED sequence number */
277 tcp_seq snd_max_rexmt; /* snd_max when rexmting snd_una */
278 struct scoreboard scb; /* sack scoreboard */
279 struct raw_sackblock reportblk; /* incoming segment or D-SACK block */
280 struct raw_sackblock encloseblk;
282 struct raw_sackblock sackhistory[MAX_SACK_REPORT_BLOCKS]; /* reported */
284 TAILQ_ENTRY(tcpcb) t_outputq; /* tcp_output needed list */
286 /* bandwith limitation */
287 u_long snd_bandwidth; /* calculated bandwidth or 0 */
288 u_long snd_bwnd; /* bandwidth-controlled window */
289 int t_bw_rtttime; /* used for bandwidth calculation */
290 tcp_seq t_bw_rtseq; /* used for bandwidth calculation */
292 /* anti DoS counters */
293 u_long rcv_second; /* start of interval second */
294 u_long rcv_pps; /* received packets per second */
295 u_long rcv_byps; /* received bytes per second */
297 u_int32_t rfbuf_ts; /* recv buffer autoscaling timestamp */
298 int rfbuf_cnt; /* recv buffer autoscaling byte count */
300 int t_keepinit; /* time to establish connection */
302 int t_keepidle; /* time before keepalive probes begin */
303 int t_keepintvl; /* time between keepalive probes */
304 int t_keepcnt; /* maximum number of keepalive probes */
305 int t_maxidle; /* time to drop after starting probes */
307 int t_rxtsyn; /* time spent in SYN or SYN|ACK rexmt */
310 #define IN_FASTRECOVERY(tp) (tp->t_flags & TF_FASTRECOVERY)
311 #define ENTER_FASTRECOVERY(tp) tp->t_flags |= TF_FASTRECOVERY
312 #define EXIT_FASTRECOVERY(tp) tp->t_flags &= ~TF_FASTRECOVERY
316 * Defines which are needed by the xform_tcp module and tcp_[in|out]put
317 * for SADB verification and lookup.
319 #define TCP_SIGLEN 16 /* length of computed digest in bytes */
320 #define TCP_KEYLEN_MIN 1 /* minimum length of TCP-MD5 key */
321 #define TCP_KEYLEN_MAX 80 /* maximum length of TCP-MD5 key */
323 * Only a single SA per host may be specified at this time. An SPI is
324 * needed in order for the KEY_ALLOCSA() lookup to work.
326 #define TCP_SIG_SPI 0x1000
327 #endif /* TCP_SIGNATURE */
332 * NOTE: Make sure this struct's size is multiple cache line size.
335 u_long tcps_connattempt; /* connections initiated */
336 u_long tcps_accepts; /* connections accepted */
337 u_long tcps_connects; /* connections established */
338 u_long tcps_drops; /* connections dropped */
339 u_long tcps_conndrops; /* embryonic connections dropped */
340 u_long tcps_minmssdrops; /* average minmss too low drops */
341 u_long tcps_closed; /* conn. closed (includes drops) */
342 u_long tcps_segstimed; /* segs where we tried to get rtt */
343 u_long tcps_rttupdated; /* times we succeeded */
344 u_long tcps_delack; /* delayed acks sent */
345 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
346 u_long tcps_rexmttimeo; /* retransmit timeouts */
347 u_long tcps_persisttimeo; /* persist timeouts */
348 u_long tcps_keeptimeo; /* keepalive timeouts */
349 u_long tcps_keepprobe; /* keepalive probes sent */
350 u_long tcps_keepdrops; /* connections dropped in keepalive */
352 u_long tcps_sndtotal; /* total packets sent */
353 u_long tcps_sndpack; /* data packets sent */
354 u_long tcps_sndbyte; /* data bytes sent */
355 u_long tcps_sndrexmitpack; /* data packets retransmitted */
356 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
357 u_long tcps_sndsackrtopack; /* packets sent by SACK after RTO */
358 u_long tcps_sndsackrtobyte; /* bytes sent by SACK after RTO */
359 u_long tcps_sndfastrexmit; /* Fast Retransmissions */
360 u_long tcps_sndearlyrexmit; /* early Fast Retransmissions */
361 u_long tcps_sndlimited; /* Limited Transmit packets */
362 u_long tcps_sndrtobad; /* spurious RTO retransmissions */
363 u_long tcps_sndfastrexmitbad; /* spurious Fast Retransmissions */
364 u_long tcps_sndearlyrexmitbad; /* spurious early Fast Retransmissions,
365 a subset of tcps_sndfastrexmitbad */
366 u_long tcps_eifeldetected; /* Eifel-detected spurious rexmits */
367 u_long tcps_rttcantdetect; /* Eifel but not 1/2 RTT-detectable */
368 u_long tcps_rttdetected; /* RTT-detected spurious RTO rexmits */
369 u_long tcps_sndacks; /* ack-only packets sent */
370 u_long tcps_sndprobe; /* window probes sent */
371 u_long tcps_sndurg; /* packets sent with URG only */
372 u_long tcps_sndwinup; /* window update-only packets sent */
373 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
374 u_long tcps_sndsackpack; /* packets sent by SACK recovery alg */
375 u_long tcps_sndsackbyte; /* bytes sent by SACK recovery */
376 u_long tcps_snduna3; /* re-retransmit snd_una on 3 new seg */
377 u_long tcps_snduna1; /* re-retransmit snd_una on 1 new seg */
378 u_long tcps_sndsackopt; /* SACK options sent */
379 u_long tcps_snddsackopt; /* D-SACK options sent */
380 u_long tcps_sndidle; /* sending idle detected */
381 u_long tcps_sackrescue; /* SACK rescue data packets sent */
382 u_long tcps_sackrescue_try; /* SACK rescues attempted */
383 u_long tcps_eifelresponse; /* Eifel responses */
385 u_long tcps_rcvtotal; /* total packets received */
386 u_long tcps_rcvpack; /* packets received in sequence */
387 u_long tcps_rcvbyte; /* bytes received in sequence */
388 u_long tcps_rcvbadsum; /* packets received with ccksum errs */
389 u_long tcps_rcvbadoff; /* packets received with bad offset */
390 u_long tcps_rcvmemdrop; /* packets dropped for lack of memory */
391 u_long tcps_rcvshort; /* packets received too short */
392 u_long tcps_rcvduppack; /* duplicate-only packets received */
393 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
394 u_long tcps_rcvpartduppack; /* packets with some duplicate data */
395 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
396 u_long tcps_rcvoopack; /* out-of-order packets received */
397 u_long tcps_rcvoobyte; /* out-of-order bytes received */
398 u_long tcps_rcvpackafterwin; /* packets with data after window */
399 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
400 u_long tcps_rcvafterclose; /* packets rcvd after "close" */
401 u_long tcps_rcvwinprobe; /* rcvd window probe packets */
402 u_long tcps_rcvdupack; /* rcvd duplicate acks */
403 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
404 u_long tcps_rcvackpack; /* rcvd ack packets */
405 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
406 u_long tcps_rcvwinupd; /* rcvd window update packets */
407 u_long tcps_pawsdrop; /* segments dropped due to PAWS */
408 u_long tcps_pawsaccept; /* segments accepted, PAWS tolerance */
409 u_long tcps_predack; /* times hdr predict ok for acks */
410 u_long tcps_preddat; /* times hdr predict ok for data pkts */
411 u_long tcps_pcbcachemiss;
412 u_long tcps_cachedrtt; /* times cached RTT in route updated */
413 u_long tcps_cachedrttvar; /* times cached rttvar updated */
414 u_long tcps_cachedssthresh; /* times cached ssthresh updated */
415 u_long tcps_usedrtt; /* times RTT initialized from route */
416 u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */
417 u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/
418 u_long tcps_persistdrop; /* timeout in persist state */
419 u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
420 u_long tcps_mturesent; /* resends due to MTU discovery */
421 u_long tcps_listendrop; /* listen queue overflows */
422 u_long tcps_rcvbadsackopt; /* rcvd illegal SACK options */
423 u_long tcps_sackrenege; /* times other side reneged */
425 u_long tcps_sacksbupdate; /* times SACK scoreboard updated */
426 u_long tcps_sacksboverflow; /* times SACK scoreboard overflowed */
427 u_long tcps_sacksbreused; /* times SACK sb-block reused */
428 u_long tcps_sacksbfailed; /* times SACK sb update failed */
429 u_long tcps_sacksbfast; /* times SACK sb-block uses cache */
431 u_long tcps_sc_added; /* entry added to syncache */
432 u_long tcps_sc_retransmitted; /* syncache entry was retransmitted */
433 u_long tcps_sc_dupsyn; /* duplicate SYN packet */
434 u_long tcps_sc_dropped; /* could not reply to packet */
435 u_long tcps_sc_completed; /* successful extraction of entry */
436 u_long tcps_sc_bucketoverflow; /* syncache per-bucket limit hit */
437 u_long tcps_sc_cacheoverflow; /* syncache cache limit hit */
438 u_long tcps_sc_reset; /* RST removed entry from syncache */
439 u_long tcps_sc_stale; /* timed out or listen socket gone */
440 u_long tcps_sc_aborted; /* syncache entry aborted */
441 u_long tcps_sc_badack; /* removed due to bad ACK */
442 u_long tcps_sc_unreach; /* ICMP unreachable received */
443 u_long tcps_sc_zonefail; /* zalloc() failed */
444 u_long tcps_sc_sendcookie; /* SYN cookie sent */
445 u_long tcps_sc_recvcookie; /* SYN cookie received */
447 u_long tcps_pad[6]; /* pad to cache line size (64B) */
452 #define tcpstat tcpstats_percpu[mycpuid]
456 extern struct tcp_stats tcpstats_percpu[MAXCPU];
458 static const int tcprexmtthresh = 3;
462 * Structure to hold TCP options that are only used during segment
463 * processing (in tcp_input), but not held in the tcpcb.
464 * It's basically used to reduce the number of parameters
468 u_int to_flags; /* which options are present */
469 #define TOF_TS 0x0001 /* timestamp */
470 #define TOF_MSS 0x0010
471 #define TOF_SCALE 0x0020
472 #define TOF_SACK_PERMITTED 0x0040
473 #define TOF_SACK 0x0080
474 #define TOF_SIGNATURE 0x0100 /* signature option present */
475 #define TOF_SIGLEN 0x0200 /* signature length valid (RFC2385) */
476 #define TOF_DSACK 0x0400 /* D-SACK */
477 #define TOF_SACK_REDUNDANT 0x0800 /* all SACK blocks are known */
481 u_int8_t to_requested_s_scale;
482 u_int8_t to_nsackblocks;
483 struct raw_sackblock *to_sackblocks;
487 inp_gen_t sc_inp_gencnt; /* pointer check */
488 struct tcpcb *sc_tp; /* tcb for listening socket */
489 struct mbuf *sc_ipopts; /* source route */
490 struct in_conninfo sc_inc; /* addresses */
491 #define sc_route sc_inc.inc_route
492 #define sc_route6 sc_inc.inc6_route
493 u_int32_t sc_tsrecent;
494 tcp_seq sc_irs; /* seq from peer */
495 tcp_seq sc_iss; /* our ISS */
496 u_long sc_rxttime; /* retransmit time */
497 u_int16_t sc_rxtslot; /* retransmit counter */
498 u_int16_t sc_peer_mss; /* peer's MSS */
499 u_int16_t sc_wnd; /* advertised window */
500 u_int8_t sc_requested_s_scale:4,
501 sc_request_r_scale:4;
503 #define SCF_NOOPT 0x01 /* no TCP options */
504 #define SCF_WINSCALE 0x02 /* negotiated window scaling */
505 #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */
506 #define SCF_UNUSED 0x08 /* unused */
507 #define SCF_UNREACH 0x10 /* icmp unreachable received */
508 #define SCF_SACK_PERMITTED 0x20 /* saw SACK permitted option */
509 #define SCF_SIGNATURE 0x40 /* send MD5 digests */
510 #define SCF_MARKER 0x80 /* not a real entry */
511 int sc_rxtused; /* time spent in SYN|ACK rxt */
512 u_long sc_sndwnd; /* send window */
513 TAILQ_ENTRY(syncache) sc_hash;
514 TAILQ_ENTRY(syncache) sc_timerq;
517 struct syncache_head {
518 TAILQ_HEAD(, syncache) sch_bucket;
522 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
523 #define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
526 * The smoothed round-trip time and estimated variance
527 * are stored as fixed point numbers scaled by the values below.
528 * For convenience, these scales are also used in smoothing the average
529 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
530 * With these scales, srtt has 3 bits to the right of the binary point,
531 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
532 * binary point, and is smoothed with an ALPHA of 0.75.
534 #define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */
535 #define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */
536 #define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */
537 #define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */
538 #define TCP_DELTA_SHIFT 2 /* see tcp_input.c */
541 * The initial retransmission should happen at rtt + 4 * rttvar.
542 * Because of the way we do the smoothing, srtt and rttvar
543 * will each average +1/2 tick of bias. When we compute
544 * the retransmit timer, we want 1/2 tick of rounding and
545 * 1 extra tick because of +-1/2 tick uncertainty in the
546 * firing of the timer. The bias will give us exactly the
547 * 1.5 tick we need. But, because the bias is
548 * statistical, we have to test that we don't drop below
549 * the minimum feasible timer (which is 2 ticks).
550 * This version of the macro adapted from a paper by Lawrence
551 * Brakmo and Larry Peterson which outlines a problem caused
552 * by insufficient precision in the original implementation,
553 * which results in inappropriately large RTO values for very
556 #define TCP_REXMTVAL(tp) \
557 max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \
558 + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
561 * TCB structure exported to user-land via sysctl(3).
562 * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
563 * included. Not all of our clients do.
565 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
570 struct xsocket xt_socket;
571 u_quad_t xt_alignment_hack;
576 * Names for TCP sysctl objects
578 #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */
579 /* 2 was TCPCTL_DO_RFC1644 */
580 #define TCPCTL_MSSDFLT 3 /* MSS default */
581 #define TCPCTL_STATS 4 /* statistics (read-only) */
582 #define TCPCTL_RTTDFLT 5 /* default RTT estimate */
583 #define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */
584 #define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */
585 #define TCPCTL_SENDSPACE 8 /* send buffer space */
586 #define TCPCTL_RECVSPACE 9 /* receive buffer space */
587 #define TCPCTL_KEEPINIT 10 /* timeout for establishing syn */
588 #define TCPCTL_PCBLIST 11 /* list of all outstanding PCBs */
589 #define TCPCTL_DELACKTIME 12 /* time before sending delayed ACK */
590 #define TCPCTL_V6MSSDFLT 13 /* MSS default for IPv6 */
591 #define TCPCTL_MAXID 14
593 #define TCPCTL_NAMES { \
595 { "rfc1323", CTLTYPE_INT }, \
596 { "reserved", CTLTYPE_INT}, /* was rfc1644 */ \
597 { "mssdflt", CTLTYPE_INT }, \
598 { "stats", CTLTYPE_STRUCT }, \
599 { "rttdflt", CTLTYPE_INT }, \
600 { "keepidle", CTLTYPE_INT }, \
601 { "keepintvl", CTLTYPE_INT }, \
602 { "sendspace", CTLTYPE_INT }, \
603 { "recvspace", CTLTYPE_INT }, \
604 { "keepinit", CTLTYPE_INT }, \
605 { "pcblist", CTLTYPE_STRUCT }, \
606 { "delacktime", CTLTYPE_INT }, \
607 { "v6mssdflt", CTLTYPE_INT }, \
612 SYSCTL_DECL(_net_inet_tcp);
615 #define TCP_DO_SACK(tp) ((tp)->t_flags & TF_SACK_PERMITTED)
616 #define TCP_DO_NCR(tp) (((tp)->t_flags & TF_NCR) && TCP_DO_SACK((tp)))
617 #define TCP_SACK_BLKEND(len, thflags) \
618 ((len) + (((thflags) & TH_FIN) != 0))
620 TAILQ_HEAD(tcpcbackqhead,tcpcb);
622 extern struct inpcbinfo tcbinfo[];
623 extern struct tcpcbackqhead tcpcbackq[];
625 extern int tcp_mssdflt; /* XXX */
626 extern int tcp_minmss;
627 extern int tcp_delack_enabled;
628 extern int path_mtu_discovery;
633 int tcp_addrcpu(in_addr_t faddr, in_port_t fport,
634 in_addr_t laddr, in_port_t lport);
636 tcp_addrport(in_addr_t faddr, in_port_t fport,
637 in_addr_t laddr, in_port_t lport);
638 struct lwkt_port *tcp_addrport0(void);
639 void tcp_canceltimers (struct tcpcb *);
641 tcp_close (struct tcpcb *);
642 void tcp_ctlinput(union netmsg *);
643 void tcp_ctloutput(union netmsg *);
645 tcp_drop (struct tcpcb *, int);
646 void tcp_drain (void);
647 void tcp_init (void);
648 void tcp_thread_init (void);
649 int tcp_input (struct mbuf **, int *, int);
650 void tcp_mss (struct tcpcb *, int);
651 int tcp_mssopt (struct tcpcb *);
652 void tcp_drop_syn_sent (struct inpcb *, int);
653 void tcp_mtudisc (struct inpcb *, int);
655 tcp_newtcpcb (struct inpcb *);
656 int tcp_output(struct tcpcb *);
657 int tcp_output_fair(struct tcpcb *);
658 void tcp_output_init(struct tcpcb *);
659 void tcp_output_cancel(struct tcpcb *);
661 tcp_output_pending(struct tcpcb *);
662 void tcp_quench (struct inpcb *, int);
663 void tcp_respond (struct tcpcb *, void *,
664 struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
666 tcp_rtlookup (struct in_conninfo *);
667 int tcp_sack_bytes_below(const struct scoreboard *scb, tcp_seq seq);
668 void tcp_sack_destroy(struct scoreboard *scb);
669 void tcp_sack_discard(struct tcpcb *tp);
670 void tcp_sack_report_cleanup(struct tcpcb *tp);
672 tcp_sack_report_needed(const struct tcpcb *tp);
673 int tcp_sack_ndsack_blocks(const struct raw_sackblock *blocks,
674 const int numblocks, tcp_seq snd_una);
675 void tcp_sack_fill_report(struct tcpcb *tp, u_char *opt, u_int *plen);
677 tcp_sack_has_sacked(const struct scoreboard *scb, u_int amount);
678 void tcp_sack_tcpcb_init(struct tcpcb *tp);
679 uint32_t tcp_sack_compute_pipe(const struct tcpcb *tp);
681 tcp_sack_nextseg(struct tcpcb *tp, tcp_seq *nextrexmt, uint32_t *len,
684 tcp_sack_islost(const struct scoreboard *scb, tcp_seq seq);
685 void tcp_sack_update_lostseq(struct scoreboard *scb, tcp_seq snd_una,
686 u_int maxseg, int rxtthresh);
688 void tcp_sack_revert_scoreboard(struct scoreboard *scb, tcp_seq snd_una,
690 void tcp_sack_save_scoreboard(struct scoreboard *scb);
692 void tcp_sack_skip_sacked(struct scoreboard *scb, tcp_seq *prexmt);
693 uint32_t tcp_sack_first_unsacked_len(const struct tcpcb *tp);
694 void tcp_sack_update_scoreboard(struct tcpcb *tp, struct tcpopt *to);
695 void tcp_save_congestion_state(struct tcpcb *tp);
696 void tcp_revert_congestion_state(struct tcpcb *tp);
697 void tcp_setpersist (struct tcpcb *);
698 struct tcptemp *tcp_maketemplate (struct tcpcb *);
699 void tcp_freetemplate (struct tcptemp *);
700 void tcp_fillheaders (struct tcpcb *, void *, void *, boolean_t);
702 tcp_soport(struct socket *, struct sockaddr *, struct mbuf **);
704 tcp_ctlport(int, struct sockaddr *, void *);
706 tcp_timers (struct tcpcb *, int);
707 void tcp_trace (short, short, struct tcpcb *, void *, struct tcphdr *,
709 void tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq);
710 u_long tcp_initial_window(struct tcpcb *tp);
711 void tcp_timer_keep_activity(struct tcpcb *tp, int thflags);
712 void syncache_init(void);
713 void syncache_unreach(struct in_conninfo *, struct tcphdr *);
714 int syncache_expand(struct in_conninfo *, struct tcphdr *,
715 struct socket **, struct mbuf *);
716 int syncache_add(struct in_conninfo *, struct tcpopt *,
717 struct tcphdr *, struct socket *, struct mbuf *);
718 void syncache_chkrst(struct in_conninfo *, struct tcphdr *);
719 void syncache_badack(struct in_conninfo *);
720 void syncache_destroy(struct tcpcb *tp);
723 int tcpsignature_apply(void *fstate, void *data, unsigned int len);
724 int tcpsignature_compute(struct mbuf *m, int len, int tcpoptlen,
725 u_char *buf, u_int direction);
726 #endif /* TCP_SIGNATURE */
728 extern struct pr_usrreqs tcp_usrreqs;
729 extern u_long tcp_sendspace;
730 extern u_long tcp_recvspace;
731 tcp_seq tcp_new_isn (struct tcpcb *);
735 #endif /* _NETINET_TCP_VAR_H_ */