1 /*
2 * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved.
3 * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved.
4 *
5 * This code is derived from software contributed to The DragonFly Project
6 * by Jeffrey M. Hsu.
7 *
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.
19 *
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.
32 */
33
34 /*
35 * Copyright (c) 1982, 1986, 1993, 1994, 1995
36 * The Regents of the University of California. All rights reserved.
37 *
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. Neither the name of the University nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 * SUCH DAMAGE.
61 *
62 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
63 * $FreeBSD: src/sys/netinet/tcp_var.h,v 1.56.2.13 2003/02/03 02:34:07 hsu Exp $
64 */
65
66 #ifndef _NETINET_TCP_VAR_H_
67 #define _NETINET_TCP_VAR_H_
68
69 #ifndef _NETINET_IN_PCB_H_
70 #include <netinet/in_pcb.h> /* needed for in_conninfo, inp_gen_t */
71 #endif
72 #ifndef _NETINET_TCP_H_
73 #include <netinet/tcp.h>
74 #endif
75
76 /*
77 * Kernel variables for tcp.
78 */
79 extern int tcp_do_rfc1323;
80 extern int tcp_low_rtobase;
81 extern int tcp_ncr_linklocal;
82 extern int tcp_ncr_rxtthresh_max;
83 extern int tcp_do_sack;
84 extern int tcp_do_smartsack;
85 extern int tcp_do_rescuesack;
86 extern int tcp_aggressive_rescuesack;
87 extern int tcp_do_rfc6675;
88 extern int tcp_rfc6675_rxt;
89 extern int tcp_aggregate_acks;
90 extern int tcp_eifel_rtoinc;
91 extern int tcp_prio_synack;
92
93 /* TCP segment queue entry */
94 struct tseg_qent {
95 TAILQ_ENTRY(tseg_qent) tqe_q;
96 int tqe_len; /* TCP segment data length */
97 struct tcphdr *tqe_th; /* a pointer to tcp header */
98 struct mbuf *tqe_m; /* mbuf contains packet */
99 };
100 TAILQ_HEAD(tsegqe_head, tseg_qent);
101 extern int tcp_reass_maxseg;
102 extern int tcp_reass_qsize;
103 #ifdef MALLOC_DECLARE
104 MALLOC_DECLARE(M_TSEGQ);
105 #endif
106
107 struct tcptemp {
108 u_char tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
109 struct tcphdr tt_t;
110 };
111
112 #define tcp6cb tcpcb /* for KAME src sync over BSD*'s */
113
114 struct raw_sackblock { /* covers [start, end) */
115 tcp_seq rblk_start;
116 tcp_seq rblk_end;
117 };
118
119 /* maximum number of SACK blocks that will fit in the TCP option space */
120 #define MAX_SACK_REPORT_BLOCKS 4
121
122 TAILQ_HEAD(sackblock_list, sackblock);
123
124 struct scoreboard {
125 int nblocks;
126 struct sackblock_list sackblocks;
127 tcp_seq lostseq; /* passed SACK lost test */
128 struct sackblock *lastfound; /* search hint */
129 struct sackblock *freecache; /* one slot free block cache */
130 };
131
132 struct netmsg_tcp_timer;
133 struct netmsg_base;
134
135 struct tcp_pcbport {
136 struct inpcbport t_phd;
137 } __cachealign;
138
139 /*
140 * Tcp control block, one per tcp; fields:
141 * Organized for 16 byte cacheline efficiency.
142 */
143 struct tcpcb {
144 struct tsegqe_head t_segq;
145 int t_dupacks; /* consecutive dup acks recd */
146 int t_rxtthresh; /* # dup acks to start fast rxt */
147 int tt_cpu; /* sanity check the cpu */
148
149 struct tcp_pcbport *t_pcbport; /* per-cpu local port cache for
150 * accept(2)'ed sockets */
151
152 struct tcp_callout *tt_rexmt; /* retransmit timer */
153 struct tcp_callout *tt_persist;/* retransmit persistence */
154 struct tcp_callout *tt_keep; /* keepalive */
155 struct tcp_callout *tt_2msl; /* 2*msl TIME_WAIT timer */
156 struct tcp_callout *tt_delack; /* delayed ACK timer */
157 struct netmsg_tcp_timer *tt_msg; /* timer message */
158
159 struct netmsg_base *tt_sndmore;/* send more segments (fairsend) */
160
161 struct inpcb *t_inpcb; /* back pointer to internet pcb */
162 int t_state; /* state of this connection */
163 u_int t_flags;
164 #define TF_ACKNOW 0x00000001 /* ack peer immediately */
165 #define TF_DELACK 0x00000002 /* ack, but try to delay it */
166 #define TF_NODELAY 0x00000004 /* don't delay packets to coalesce */
167 #define TF_NOOPT 0x00000008 /* don't use tcp options */
168 #define TF_SENTFIN 0x00000010 /* have sent FIN */
169 #define TF_REQ_SCALE 0x00000020 /* have/will request window scaling */
170 #define TF_RCVD_SCALE 0x00000040 /* other side has requested scaling */
171 #define TF_REQ_TSTMP 0x00000080 /* have/will request timestamps */
172 #define TF_RCVD_TSTMP 0x00000100 /* a timestamp was received in SYN */
173 #define TF_SACK_PERMITTED 0x00000200 /* other side said I could SACK */
174 #define TF_NEEDSYN 0x00000400 /* send SYN (implicit state) */
175 #define TF_NEEDFIN 0x00000800 /* send FIN (implicit state) */
176 #define TF_NOPUSH 0x00001000 /* don't push */
177 #define TF_LISTEN 0x00002000 /* listen(2) has been called */
178 #define TF_SIGNATURE 0x00004000 /* require MD5 digests (RFC2385) */
179 #define TF_NCR 0x00008000 /* Non-Congestion Robustness RFC4653 */
180 #define TF_MORETOCOME 0x00010000 /* More data to be appended to sock */
181 #define TF_SAWFIN 0x00020000 /* FIN has been seen */
182 #define TF_LASTIDLE 0x00040000 /* connection was previously idle */
183 #define TF_RXWIN0SENT 0x00080000 /* sent a receiver win 0 in response */
184 #define TF_FASTRECOVERY 0x00100000 /* in Fast Recovery */
185 #define TF_QUEDFIN 0x00200000 /* FIN has been received */
186 #define TF_XMITNOW 0x00400000 /* Temporarily override Nagle */
187 #define TF_UNUSED008 0x00800000
188 #define TF_UNUSED009 0x01000000
189 #define TF_FORCE 0x02000000 /* Set if forcing out a byte */
190 #define TF_ONOUTPUTQ 0x04000000 /* on t_outputq list */
191 #define TF_FAIRSEND 0x08000000 /* fairsend is requested */
192 #define TF_UNUSED003 0x10000000
193 #define TF_UNUSED004 0x20000000
194 #define TF_KEEPALIVE 0x40000000 /* temporary keepalive */
195 #define TF_RXRESIZED 0x80000000 /* rcvbuf was resized */
196 tcp_seq snd_up; /* send urgent pointer */
197 u_long snd_last; /* time last data were sent */
198
199 tcp_seq snd_una; /* send unacknowledged */
200 tcp_seq snd_recover; /* for use with Fast Recovery */
201 tcp_seq snd_max; /* highest sequence number sent;
202 * used to recognize retransmits */
203 tcp_seq snd_nxt; /* send next */
204
205 tcp_seq snd_wl1; /* window update seg seq number */
206 tcp_seq snd_wl2; /* window update seg ack number */
207 tcp_seq iss; /* initial send sequence number */
208 tcp_seq irs; /* initial receive sequence number */
209
210 tcp_seq rcv_nxt; /* receive next */
211 tcp_seq rcv_adv; /* advertised window */
212 u_long rcv_wnd; /* receive window */
213 tcp_seq rcv_up; /* receive urgent pointer */
214
215 u_long snd_wnd; /* send window */
216 u_long snd_cwnd; /* congestion-controlled window */
217 u_long snd_wacked; /* bytes acked in one send window */
218 u_long snd_ssthresh; /* snd_cwnd size threshold for
219 * for slow start exponential to
220 * linear switch */
221
222 int t_rxtcur; /* current retransmit value (ticks) */
223 u_int t_maxseg; /* maximum segment size */
224 int t_srtt; /* smoothed round-trip time */
225 int t_rttvar; /* variance in round-trip time */
226
227 u_int t_maxopd; /* mss plus options */
228
229 u_long t_rcvtime; /* reception inactivity time */
230 u_long t_starttime; /* time connection was established */
231 int t_rtttime; /* round trip time */
232 tcp_seq t_rtseq; /* sequence number being timed */
233
234 int t_rxtshift; /* log(2) of rexmt exp. backoff */
235 u_int t_rttmin; /* minimum rtt allowed */
236 u_int t_rttbest; /* best rtt we've seen */
237 u_long t_rttupdated; /* number of times rtt sampled */
238 u_long max_sndwnd; /* largest window peer has offered */
239
240 int t_softerror; /* possible error not yet reported */
241 /* out-of-band data */
242 char t_oobflags; /* have some */
243 char t_iobc; /* input character */
244 #define TCPOOB_HAVEDATA 0x01
245 #define TCPOOB_HADDATA 0x02
246
247 /* RFC 1323 variables */
248 u_char snd_scale; /* window scaling for send window */
249 u_char rcv_scale; /* window scaling for recv window */
250 u_char request_r_scale; /* pending window scaling */
251 u_long ts_recent; /* timestamp echo data */
252
253 u_long ts_recent_age; /* when last updated */
254 tcp_seq last_ack_sent;
255
256 /* experimental */
257 u_int rxt_flags;
258 #define TRXT_F_REBASERTO 0x0001 /* Recalculate RTO based on new RTT */
259 #define TRXT_F_WASFRECOVERY 0x0002 /* was in Fast Recovery */
260 #define TRXT_F_FIRSTACCACK 0x0004 /* Look for 1st acceptable ACK. */
261 #define TRXT_F_FASTREXMT 0x0008 /* Did Fast Retransmit. */
262 #define TRXT_F_EARLYREXMT 0x0010 /* Did Early (Fast) Retransmit. */
263 int t_srtt_prev; /* adjusted SRTT prior to retransmit */
264 int t_rttvar_prev; /* RTTVAR prior to retransmit */
265 int t_rxtcur_prev; /* rexmt timeout prior to retransmit */
266 tcp_seq snd_max_prev; /* SND_MAX prior to retransmit */
267 u_long snd_cwnd_prev; /* cwnd prior to retransmit */
268 u_long snd_wacked_prev; /* prior bytes acked in send window */
269 u_long snd_ssthresh_prev; /* ssthresh prior to retransmit */
270 tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */
271 u_long t_badrxtwin; /* window for retransmit recovery */
272 u_long t_rexmtTS; /* timestamp of last retransmit */
273 u_char snd_limited; /* segments limited transmitted */
274
275 u_int sack_flags;
276 #define TSACK_F_SACKRESCUED 0x0001 /* sent rescue SACK recovery data */
277 #define TSACK_F_DUPSEG 0x0002 /* last seg a duplicate */
278 #define TSACK_F_ENCLOSESEG 0x0004 /* enclosing SACK block */
279 #define TSACK_F_SACKLEFT 0x0008 /* send SACK blocks from left side */
280 tcp_seq rexmt_high; /* highest seq # retransmitted + 1 */
281 tcp_seq rexmt_rescue; /* rescue SACKED sequence number */
282 tcp_seq snd_max_rexmt; /* snd_max when rexmting snd_una */
283 struct scoreboard scb; /* sack scoreboard */
284 struct raw_sackblock reportblk; /* incoming segment or D-SACK block */
285 struct raw_sackblock encloseblk;
286 int nsackhistory;
287 struct raw_sackblock sackhistory[MAX_SACK_REPORT_BLOCKS]; /* reported */
288
289 TAILQ_ENTRY(tcpcb) t_outputq; /* tcp_output needed list */
290
291 /* bandwith limitation */
292 u_long snd_bandwidth; /* calculated bandwidth or 0 */
293 u_long snd_bwnd; /* bandwidth-controlled window */
294 int t_bw_rtttime; /* used for bandwidth calculation */
295 tcp_seq t_bw_rtseq; /* used for bandwidth calculation */
296
297 /* anti DoS counters */
298 u_long rcv_second; /* start of interval second */
299 u_long rcv_pps; /* received packets per second */
300 u_long rcv_byps; /* received bytes per second */
301
302 u_int32_t rfbuf_ts; /* recv buffer autoscaling timestamp */
303 int rfbuf_cnt; /* recv buffer autoscaling byte count */
304
305 int t_keepinit; /* time to establish connection */
306
307 int t_keepidle; /* time before keepalive probes begin */
308 int t_keepintvl; /* time between keepalive probes */
309 int t_keepcnt; /* maximum number of keepalive probes */
310 int t_maxidle; /* time to drop after starting probes */
311
312 int t_rxtsyn; /* time spent in SYN or SYN|ACK rexmt */
313 };
314
315 #define IN_FASTRECOVERY(tp) (tp->t_flags & TF_FASTRECOVERY)
316 #define ENTER_FASTRECOVERY(tp) tp->t_flags |= TF_FASTRECOVERY
317 #define EXIT_FASTRECOVERY(tp) tp->t_flags &= ~TF_FASTRECOVERY
318
319 #ifdef TCP_SIGNATURE
320 /*
321 * Defines which are needed by the xform_tcp module and tcp_[in|out]put
322 * for SADB verification and lookup.
323 */
324 #define TCP_SIGLEN 16 /* length of computed digest in bytes */
325 #define TCP_KEYLEN_MIN 1 /* minimum length of TCP-MD5 key */
326 #define TCP_KEYLEN_MAX 80 /* maximum length of TCP-MD5 key */
327 /*
328 * Only a single SA per host may be specified at this time. An SPI is
329 * needed in order for the KEY_ALLOCSA() lookup to work.
330 */
331 #define TCP_SIG_SPI 0x1000
332 #endif /* TCP_SIGNATURE */
333
334 /*
335 * TCP statistics.
336 *
337 * NOTE: Make sure this struct's size is multiple cache line size.
338 */
339 struct tcp_stats {
340 u_long tcps_connattempt; /* connections initiated */
341 u_long tcps_accepts; /* connections accepted */
342 u_long tcps_connects; /* connections established */
343 u_long tcps_drops; /* connections dropped */
344 u_long tcps_conndrops; /* embryonic connections dropped */
345 u_long tcps_minmssdrops; /* average minmss too low drops */
346 u_long tcps_closed; /* conn. closed (includes drops) */
347 u_long tcps_segstimed; /* segs where we tried to get rtt */
348 u_long tcps_rttupdated; /* times we succeeded */
349 u_long tcps_delack; /* delayed acks sent */
350 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
351 u_long tcps_rexmttimeo; /* retransmit timeouts */
352 u_long tcps_persisttimeo; /* persist timeouts */
353 u_long tcps_keeptimeo; /* keepalive timeouts */
354 u_long tcps_keepprobe; /* keepalive probes sent */
355 u_long tcps_keepdrops; /* connections dropped in keepalive */
356
357 u_long tcps_sndtotal; /* total packets sent */
358 u_long tcps_sndpack; /* data packets sent */
359 u_long tcps_sndbyte; /* data bytes sent */
360 u_long tcps_sndrexmitpack; /* data packets retransmitted */
361 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
362 u_long tcps_sndsackrtopack; /* packets sent by SACK after RTO */
363 u_long tcps_sndsackrtobyte; /* bytes sent by SACK after RTO */
364 u_long tcps_sndfastrexmit; /* Fast Retransmissions */
365 u_long tcps_sndearlyrexmit; /* early Fast Retransmissions */
366 u_long tcps_sndlimited; /* Limited Transmit packets */
367 u_long tcps_sndrtobad; /* spurious RTO retransmissions */
368 u_long tcps_sndfastrexmitbad; /* spurious Fast Retransmissions */
369 u_long tcps_sndearlyrexmitbad; /* spurious early Fast Retransmissions,
370 a subset of tcps_sndfastrexmitbad */
371 u_long tcps_eifeldetected; /* Eifel-detected spurious rexmits */
372 u_long tcps_rttcantdetect; /* Eifel but not 1/2 RTT-detectable */
373 u_long tcps_rttdetected; /* RTT-detected spurious RTO rexmits */
374 u_long tcps_sndacks; /* ack-only packets sent */
375 u_long tcps_sndprobe; /* window probes sent */
376 u_long tcps_sndurg; /* packets sent with URG only */
377 u_long tcps_sndwinup; /* window update-only packets sent */
378 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
379 u_long tcps_sndsackpack; /* packets sent by SACK recovery alg */
380 u_long tcps_sndsackbyte; /* bytes sent by SACK recovery */
381 u_long tcps_snduna3; /* re-retransmit snd_una on 3 new seg */
382 u_long tcps_snduna1; /* re-retransmit snd_una on 1 new seg */
383 u_long tcps_sndsackopt; /* SACK options sent */
384 u_long tcps_snddsackopt; /* D-SACK options sent */
385 u_long tcps_sndidle; /* sending idle detected */
386 u_long tcps_sackrescue; /* SACK rescue data packets sent */
387 u_long tcps_sackrescue_try; /* SACK rescues attempted */
388 u_long tcps_eifelresponse; /* Eifel responses */
389
390 u_long tcps_rcvtotal; /* total packets received */
391 u_long tcps_rcvpack; /* packets received in sequence */
392 u_long tcps_rcvbyte; /* bytes received in sequence */
393 u_long tcps_rcvbadsum; /* packets received with ccksum errs */
394 u_long tcps_rcvbadoff; /* packets received with bad offset */
395 u_long tcps_rcvmemdrop; /* packets dropped for lack of memory */
396 u_long tcps_rcvshort; /* packets received too short */
397 u_long tcps_rcvduppack; /* duplicate-only packets received */
398 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
399 u_long tcps_rcvpartduppack; /* packets with some duplicate data */
400 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
401 u_long tcps_rcvoopack; /* out-of-order packets received */
402 u_long tcps_rcvoobyte; /* out-of-order bytes received */
403 u_long tcps_rcvpackafterwin; /* packets with data after window */
404 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
405 u_long tcps_rcvafterclose; /* packets rcvd after "close" */
406 u_long tcps_rcvwinprobe; /* rcvd window probe packets */
407 u_long tcps_rcvdupack; /* rcvd duplicate acks */
408 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
409 u_long tcps_rcvackpack; /* rcvd ack packets */
410 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
411 u_long tcps_rcvwinupd; /* rcvd window update packets */
412 u_long tcps_pawsdrop; /* segments dropped due to PAWS */
413 u_long tcps_pawsaccept; /* segments accepted, PAWS tolerance */
414 u_long tcps_predack; /* times hdr predict ok for acks */
415 u_long tcps_preddat; /* times hdr predict ok for data pkts */
416 u_long tcps_pcbcachemiss;
417 u_long tcps_cachedrtt; /* times cached RTT in route updated */
418 u_long tcps_cachedrttvar; /* times cached rttvar updated */
419 u_long tcps_cachedssthresh; /* times cached ssthresh updated */
420 u_long tcps_usedrtt; /* times RTT initialized from route */
421 u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */
422 u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/
423 u_long tcps_persistdrop; /* timeout in persist state */
424 u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
425 u_long tcps_mturesent; /* resends due to MTU discovery */
426 u_long tcps_listendrop; /* listen queue overflows */
427 u_long tcps_rcvbadsackopt; /* rcvd illegal SACK options */
428 u_long tcps_sackrenege; /* times other side reneged */
429
430 u_long tcps_sacksbupdate; /* times SACK scoreboard updated */
431 u_long tcps_sacksboverflow; /* times SACK scoreboard overflowed */
432 u_long tcps_sacksbreused; /* times SACK sb-block reused */
433 u_long tcps_sacksbfailed; /* times SACK sb update failed */
434 u_long tcps_sacksbfast; /* times SACK sb-block uses cache */
435
436 u_long tcps_sc_added; /* entry added to syncache */
437 u_long tcps_sc_retransmitted; /* syncache entry was retransmitted */
438 u_long tcps_sc_dupsyn; /* duplicate SYN packet */
439 u_long tcps_sc_dropped; /* could not reply to packet */
440 u_long tcps_sc_completed; /* successful extraction of entry */
441 u_long tcps_sc_bucketoverflow; /* syncache per-bucket limit hit */
442 u_long tcps_sc_cacheoverflow; /* syncache cache limit hit */
443 u_long tcps_sc_reset; /* RST removed entry from syncache */
444 u_long tcps_sc_stale; /* timed out or listen socket gone */
445 u_long tcps_sc_aborted; /* syncache entry aborted */
446 u_long tcps_sc_badack; /* removed due to bad ACK */
447 u_long tcps_sc_unreach; /* ICMP unreachable received */
448 u_long tcps_sc_zonefail; /* zalloc() failed */
449 u_long tcps_sc_sendcookie; /* SYN cookie sent */
450 u_long tcps_sc_recvcookie; /* SYN cookie received */
451
452 u_long tcps_pad[6]; /* pad to cache line size (64B) */
453 };
454 #ifdef _KERNEL
455 CTASSERT((sizeof(struct tcp_stats) & __VM_CACHELINE_MASK) == 0);
456 #endif
457
458 #ifdef _KERNEL
459
460 #ifndef _NETINET_TCP_FSM_H_
461 #include <netinet/tcp_fsm.h>
462 #endif
463
464 struct tcp_state_count {
465 u_long tcps_count[TCP_NSTATES];
466 } __cachealign;
467
468 #define tcpstat tcpstats_percpu[mycpuid]
469
470 struct sockopt;
471
472 extern struct tcp_stats tcpstats_percpu[MAXCPU];
473 extern struct tcp_state_count tcpstate_count[MAXCPU];
474
475 static const int tcprexmtthresh = 3;
476 #endif
477
478 /*
479 * Structure to hold TCP options that are only used during segment
480 * processing (in tcp_input), but not held in the tcpcb.
481 * It's basically used to reduce the number of parameters
482 * to tcp_dooptions.
483 */
484 struct tcpopt {
485 u_int to_flags; /* which options are present */
486 #define TOF_TS 0x0001 /* timestamp */
487 #define TOF_MSS 0x0010
488 #define TOF_SCALE 0x0020
489 #define TOF_SACK_PERMITTED 0x0040
490 #define TOF_SACK 0x0080
491 #define TOF_SIGNATURE 0x0100 /* signature option present */
492 #define TOF_SIGLEN 0x0200 /* signature length valid (RFC2385) */
493 #define TOF_DSACK 0x0400 /* D-SACK */
494 #define TOF_SACK_REDUNDANT 0x0800 /* all SACK blocks are known */
495 u_int32_t to_tsval;
496 u_int32_t to_tsecr;
497 u_int16_t to_mss;
498 u_int8_t to_requested_s_scale;
499 u_int8_t to_nsackblocks;
500 struct raw_sackblock *to_sackblocks;
501 };
502
503 struct syncache {
504 inp_gen_t sc_inp_gencnt; /* pointer check */
505 struct tcpcb *sc_tp; /* tcb for listening socket */
506 struct mbuf *sc_ipopts; /* source route */
507 struct in_conninfo sc_inc; /* addresses */
508 #define sc_route sc_inc.inc_route
509 #define sc_route6 sc_inc.inc6_route
510 u_int32_t sc_tsrecent;
511 uint16_t sc_hashval; /* connection hash */
512 uint16_t sc_pad; /* explicit padding */
513 tcp_seq sc_irs; /* seq from peer */
514 tcp_seq sc_iss; /* our ISS */
515 u_long sc_rxttime; /* retransmit time */
516 u_int16_t sc_rxtslot; /* retransmit counter */
517 u_int16_t sc_peer_mss; /* peer's MSS */
518 u_int16_t sc_wnd; /* advertised window */
519 u_int8_t sc_requested_s_scale:4,
520 sc_request_r_scale:4;
521 u_int8_t sc_flags;
522 #define SCF_NOOPT 0x01 /* no TCP options */
523 #define SCF_WINSCALE 0x02 /* negotiated window scaling */
524 #define SCF_TIMESTAMP 0x04 /* negotiated timestamps */
525 #define SCF_HASH 0x08 /* sc_hashval is valid */
526 #define SCF_UNREACH 0x10 /* icmp unreachable received */
527 #define SCF_SACK_PERMITTED 0x20 /* saw SACK permitted option */
528 #define SCF_SIGNATURE 0x40 /* send MD5 digests */
529 int sc_rxtused; /* time spent in SYN|ACK rxt */
530 u_long sc_sndwnd; /* send window */
531 TAILQ_ENTRY(syncache) sc_hash;
532 TAILQ_ENTRY(syncache) sc_timerq;
533 };
534
535 struct syncache_head {
536 TAILQ_HEAD(, syncache) sch_bucket;
537 u_int sch_length;
538 };
539
540 #define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
541 #define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
542
543 /*
544 * The smoothed round-trip time and estimated variance
545 * are stored as fixed point numbers scaled by the values below.
546 * For convenience, these scales are also used in smoothing the average
547 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
548 * With these scales, srtt has 3 bits to the right of the binary point,
549 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
550 * binary point, and is smoothed with an ALPHA of 0.75.
551 */
552 #define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */
553 #define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */
554 #define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */
555 #define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */
556 #define TCP_DELTA_SHIFT 2 /* see tcp_input.c */
557
558 /*
559 * The initial retransmission should happen at rtt + 4 * rttvar.
560 * Because of the way we do the smoothing, srtt and rttvar
561 * will each average +1/2 tick of bias. When we compute
562 * the retransmit timer, we want 1/2 tick of rounding and
563 * 1 extra tick because of +-1/2 tick uncertainty in the
564 * firing of the timer. The bias will give us exactly the
565 * 1.5 tick we need. But, because the bias is
566 * statistical, we have to test that we don't drop below
567 * the minimum feasible timer (which is 2 ticks).
568 * This version of the macro adapted from a paper by Lawrence
569 * Brakmo and Larry Peterson which outlines a problem caused
570 * by insufficient precision in the original implementation,
571 * which results in inappropriately large RTO values for very
572 * fast networks.
573 */
574 #define TCP_REXMTVAL(tp) \
575 max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \
576 + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
577
578 /*
579 * TCB structure exported to user-land via sysctl(3).
580 * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
581 * included. Not all of our clients do.
582 */
583 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
584 struct xtcpcb {
585 size_t xt_len;
586 struct inpcb xt_inp;
587 struct tcpcb xt_tp;
588 struct xsocket xt_socket;
589 u_quad_t xt_alignment_hack;
590 };
591 #endif
592
593 /*
594 * Names for TCP sysctl objects
595 */
596 #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */
597 /* 2 was TCPCTL_DO_RFC1644 */
598 #define TCPCTL_MSSDFLT 3 /* MSS default */
599 #define TCPCTL_STATS 4 /* statistics (read-only) */
600 #define TCPCTL_RTTDFLT 5 /* default RTT estimate */
601 #define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */
602 #define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */
603 #define TCPCTL_SENDSPACE 8 /* send buffer space */
604 #define TCPCTL_RECVSPACE 9 /* receive buffer space */
605 #define TCPCTL_KEEPINIT 10 /* timeout for establishing syn */
606 #define TCPCTL_PCBLIST 11 /* list of all outstanding PCBs */
607 #define TCPCTL_DELACKTIME 12 /* time before sending delayed ACK */
608 #define TCPCTL_V6MSSDFLT 13 /* MSS default for IPv6 */
609 #define TCPCTL_MAXID 14
610
611 #define TCPCTL_NAMES { \
612 { 0, 0 }, \
613 { "rfc1323", CTLTYPE_INT }, \
614 { "reserved", CTLTYPE_INT}, /* was rfc1644 */ \
615 { "mssdflt", CTLTYPE_INT }, \
616 { "stats", CTLTYPE_STRUCT }, \
617 { "rttdflt", CTLTYPE_INT }, \
618 { "keepidle", CTLTYPE_INT }, \
619 { "keepintvl", CTLTYPE_INT }, \
620 { "sendspace", CTLTYPE_INT }, \
621 { "recvspace", CTLTYPE_INT }, \
622 { "keepinit", CTLTYPE_INT }, \
623 { "pcblist", CTLTYPE_STRUCT }, \
624 { "delacktime", CTLTYPE_INT }, \
625 { "v6mssdflt", CTLTYPE_INT }, \
626 }
627
628 #ifdef _KERNEL
629 #ifdef SYSCTL_DECL
630 SYSCTL_DECL(_net_inet_tcp);
631 #endif
632
633 #define TCP_DO_SACK(tp) ((tp)->t_flags & TF_SACK_PERMITTED)
634 #define TCP_DO_NCR(tp) (((tp)->t_flags & TF_NCR) && TCP_DO_SACK((tp)))
635 #define TCP_SACK_BLKEND(len, thflags) \
636 ((len) + (((thflags) & TH_FIN) != 0))
637
638 struct tcpcbackq {
639 TAILQ_HEAD(, tcpcb) head;
640 } __cachealign;
641
642 extern struct inpcbinfo tcbinfo[];
643 extern struct tcpcbackq tcpcbackq[];
644
645 extern int tcp_mssdflt; /* XXX */
646 extern int tcp_minmss;
647 extern int tcp_delack_enabled;
648 extern int path_mtu_discovery;
649
650 struct ip;
651 union netmsg;
652
653 int tcp_addrcpu(in_addr_t faddr, in_port_t fport,
654 in_addr_t laddr, in_port_t lport);
655 int tcp_addrhash(in_addr_t faddr, in_port_t fport,
656 in_addr_t laddr, in_port_t lport);
657 struct lwkt_port *
658 tcp_addrport(in_addr_t faddr, in_port_t fport,
659 in_addr_t laddr, in_port_t lport);
660 struct lwkt_port *tcp_addrport0(void);
661 void tcp_canceltimers (struct tcpcb *);
662 struct tcpcb *
663 tcp_close (struct tcpcb *);
664 void tcp_ctlinput(union netmsg *);
665 void tcp_ctloutput(union netmsg *);
666 struct netmsg_pr_ctloutput *tcp_ctloutmsg(struct sockopt *);
667 inp_notify_t tcp_get_inpnotify(int cmd, const struct sockaddr *sa,
668 int *arg, struct ip **ip0, int *cpuid);
669 struct tcpcb *
670 tcp_drop (struct tcpcb *, int);
671 void tcp_drain (void);
672 void tcp_init (void);
673 void tcp_thread_init (void);
674 int tcp_input (struct mbuf **, int *, int);
675 void tcp_rmx_init (struct tcpcb *, int);
676 int tcp_mssopt (struct tcpcb *);
677 void tcp_drop_syn_sent (struct inpcb *, int);
678 void tcp_mtudisc (struct inpcb *, int);
679 void tcp_newtcpcb (struct inpcb *);
680 int tcp_output(struct tcpcb *);
681 int tcp_output_fair(struct tcpcb *);
682 void tcp_output_init(struct tcpcb *);
683 void tcp_output_cancel(struct tcpcb *);
684 boolean_t
685 tcp_output_pending(struct tcpcb *);
686 void tcp_quench (struct inpcb *, int);
687 void tcp_respond (struct tcpcb *, void *,
688 struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
689 struct rtentry *
690 tcp_rtlookup (struct in_conninfo *);
691 int tcp_sack_bytes_below(const struct scoreboard *scb, tcp_seq seq);
692 void tcp_sack_destroy(struct scoreboard *scb);
693 void tcp_sack_discard(struct tcpcb *tp);
694 void tcp_sack_report_cleanup(struct tcpcb *tp);
695 boolean_t
696 tcp_sack_report_needed(const struct tcpcb *tp);
697 int tcp_sack_ndsack_blocks(const struct raw_sackblock *blocks,
698 const int numblocks, tcp_seq snd_una);
699 void tcp_sack_fill_report(struct tcpcb *tp, u_char *opt, u_int *plen);
700 boolean_t
701 tcp_sack_has_sacked(const struct scoreboard *scb, u_int amount);
702 void tcp_sack_tcpcb_init(struct tcpcb *tp);
703 uint32_t tcp_sack_compute_pipe(const struct tcpcb *tp);
704 boolean_t
705 tcp_sack_nextseg(struct tcpcb *tp, tcp_seq *nextrexmt, uint32_t *len,
706 boolean_t *rescue);
707 boolean_t
708 tcp_sack_islost(const struct scoreboard *scb, tcp_seq seq);
709 void tcp_sack_update_lostseq(struct scoreboard *scb, tcp_seq snd_una,
710 u_int maxseg, int rxtthresh);
711 #ifdef later
712 void tcp_sack_revert_scoreboard(struct scoreboard *scb, tcp_seq snd_una,
713 u_int maxseg);
714 void tcp_sack_save_scoreboard(struct scoreboard *scb);
715 #endif
716 void tcp_sack_skip_sacked(struct scoreboard *scb, tcp_seq *prexmt);
717 uint32_t tcp_sack_first_unsacked_len(const struct tcpcb *tp);
718 void tcp_sack_update_scoreboard(struct tcpcb *tp, struct tcpopt *to);
719 void tcp_save_congestion_state(struct tcpcb *tp);
720 void tcp_revert_congestion_state(struct tcpcb *tp);
721 void tcp_setpersist (struct tcpcb *);
722 struct tcptemp *tcp_maketemplate (struct tcpcb *);
723 void tcp_freetemplate (struct tcptemp *);
724 void tcp_fillheaders (struct tcpcb *, void *, void *, boolean_t);
725 struct lwkt_port *
726 tcp_soport(struct socket *, struct sockaddr *, struct mbuf **);
727 struct lwkt_port *
728 tcp_ctlport(int, struct sockaddr *, void *, int *);
729 struct lwkt_port *
730 tcp_initport(void);
731 struct tcpcb *
732 tcp_timers (struct tcpcb *, int);
733 void tcp_trace (short, short, struct tcpcb *, void *, struct tcphdr *,
734 int);
735 void tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq);
736 u_long tcp_initial_window(struct tcpcb *tp);
737 void tcp_timer_keep_activity(struct tcpcb *tp, int thflags);
738 void syncache_init(void);
739 void syncache_unreach(struct in_conninfo *, const struct tcphdr *);
740 int syncache_expand(struct in_conninfo *, struct tcphdr *,
741 struct socket **, struct mbuf *);
742 int syncache_add(struct in_conninfo *, struct tcpopt *,
743 struct tcphdr *, struct socket *, struct mbuf *);
744 void syncache_chkrst(struct in_conninfo *, struct tcphdr *);
745 void syncache_badack(struct in_conninfo *);
746 void syncache_destroy(struct tcpcb *tp, struct tcpcb *new_tp);
747
748 #ifdef TCP_SIGNATURE
749 int tcpsignature_apply(void *fstate, void *data, unsigned int len);
750 int tcpsignature_compute(struct mbuf *m, int len, int tcpoptlen,
751 u_char *buf, u_int direction);
752 #endif /* TCP_SIGNATURE */
753
754 extern struct pr_usrreqs tcp_usrreqs;
755 extern u_long tcp_sendspace;
756 extern u_long tcp_recvspace;
757 tcp_seq tcp_new_isn (struct tcpcb *);
758
759 void tcp_pcbport_create(struct tcpcb *);
760 void tcp_pcbport_destroy(struct tcpcb *);
761 void tcp_pcbport_merge_oncpu(struct tcpcb *);
762
763 static __inline void
tcp_pcbport_insert(struct tcpcb * ltp,struct inpcb * inp)764 tcp_pcbport_insert(struct tcpcb *ltp, struct inpcb *inp)
765 {
766 struct inpcbport *phd;
767 int cpu;
768
769 if (inp->inp_lport != ltp->t_inpcb->inp_lport) {
770 /*
771 * This could happen with 'ipfw forward'.
772 */
773 in_pcbinsporthash_lport(inp);
774 return;
775 }
776
777 cpu = mycpuid;
778 KASSERT(cpu < netisr_ncpus, ("invalid cpu%d", cpu));
779 phd = <p->t_pcbport[cpu].t_phd;
780
781 /*
782 * NOTE:
783 * Set inp_porthash NULL and set inp_phd properly,
784 * so that tcp_pcbport_remove() could tell that this
785 * inpcb is on the listen tcpcb per-cpu port cache.
786 */
787 inp->inp_porthash = NULL;
788 inp->inp_phd = phd;
789 LIST_INSERT_HEAD(&phd->phd_pcblist, inp, inp_portlist);
790 }
791
792 static __inline void
tcp_pcbport_remove(struct inpcb * inp)793 tcp_pcbport_remove(struct inpcb *inp)
794 {
795 if (inp->inp_porthash == NULL && inp->inp_phd != NULL) {
796 /*
797 * On listen tcpcb per-cpu port cache.
798 */
799 LIST_REMOVE(inp, inp_portlist);
800 inp->inp_phd = NULL;
801 /* NOTE: Don't whack inp_lport, which may be used later */
802 }
803 }
804
805 static __inline void
_TCP_STATE_INC(const struct tcpcb * tp)806 _TCP_STATE_INC(const struct tcpcb *tp)
807 {
808 tcpstate_count[mycpuid].tcps_count[tp->t_state]++;
809 }
810
811 static __inline void
_TCP_STATE_DEC(const struct tcpcb * tp)812 _TCP_STATE_DEC(const struct tcpcb *tp)
813 {
814 tcpstate_count[mycpuid].tcps_count[tp->t_state]--;
815 }
816
817 static __inline void
_TCP_STATE_SET(struct tcpcb * tp,int state)818 _TCP_STATE_SET(struct tcpcb *tp, int state)
819 {
820 tp->t_state = state;
821 _TCP_STATE_INC(tp);
822 }
823
824 static __inline void
TCP_STATE_INIT(struct tcpcb * tp)825 TCP_STATE_INIT(struct tcpcb *tp)
826 {
827 _TCP_STATE_SET(tp, TCPS_CLOSED);
828 }
829
830 static __inline void
TCP_STATE_TERM(struct tcpcb * tp)831 TCP_STATE_TERM(struct tcpcb *tp)
832 {
833 KASSERT(tp->t_state != TCPS_TERMINATING, ("tcpcb was terminated"));
834 _TCP_STATE_DEC(tp);
835 tp->t_state = TCPS_TERMINATING;
836 }
837
838 static __inline void
TCP_STATE_CHANGE(struct tcpcb * tp,int state)839 TCP_STATE_CHANGE(struct tcpcb *tp, int state)
840 {
841 _TCP_STATE_DEC(tp);
842 _TCP_STATE_SET(tp, state);
843 }
844
845 static __inline void
TCP_STATE_MIGRATE_START(const struct tcpcb * tp)846 TCP_STATE_MIGRATE_START(const struct tcpcb *tp)
847 {
848 _TCP_STATE_DEC(tp);
849 }
850
851 static __inline void
TCP_STATE_MIGRATE_END(const struct tcpcb * tp)852 TCP_STATE_MIGRATE_END(const struct tcpcb *tp)
853 {
854 _TCP_STATE_INC(tp);
855 }
856
857 #endif /* _KERNEL */
858
859 #endif /* _NETINET_TCP_VAR_H_ */
860