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Add MKMANDOC option to trigger building cat pages and HTML pages with
[netbsd-mini2440.git] / sys / netinet / tcp_subr.c
blobd2dbb1eebd773ac334cf59704cb138f471178894
1 /* $NetBSD: tcp_subr.c,v 1.237 2009/05/27 17:41:03 pooka Exp $ */
2
3 /*
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 /*-
33 * Copyright (c) 1997, 1998, 2000, 2001, 2008 The NetBSD Foundation, Inc.
34 * All rights reserved.
35 *
36 * This code is derived from software contributed to The NetBSD Foundation
37 * by Jason R. Thorpe and Kevin M. Lahey of the Numerical Aerospace Simulation
38 * Facility, NASA Ames Research Center.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
50 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
52 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
59 * POSSIBILITY OF SUCH DAMAGE.
60 */
61
62 /*
63 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
64 * The Regents of the University of California. All rights reserved.
65 *
66 * Redistribution and use in source and binary forms, with or without
67 * modification, are permitted provided that the following conditions
68 * are met:
69 * 1. Redistributions of source code must retain the above copyright
70 * notice, this list of conditions and the following disclaimer.
71 * 2. Redistributions in binary form must reproduce the above copyright
72 * notice, this list of conditions and the following disclaimer in the
73 * documentation and/or other materials provided with the distribution.
74 * 3. Neither the name of the University nor the names of its contributors
75 * may be used to endorse or promote products derived from this software
76 * without specific prior written permission.
77 *
78 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
79 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
80 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
81 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
82 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
83 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
84 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
85 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
86 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
87 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
88 * SUCH DAMAGE.
89 *
90 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
91 */
92
93 #include <sys/cdefs.h>
94 __KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.237 2009/05/27 17:41:03 pooka Exp $");
95
96 #include "opt_inet.h"
97 #include "opt_ipsec.h"
98 #include "opt_tcp_compat_42.h"
99 #include "opt_inet_csum.h"
100 #include "opt_mbuftrace.h"
101 #include "rnd.h"
102
103 #include <sys/param.h>
104 #include <sys/proc.h>
105 #include <sys/systm.h>
106 #include <sys/malloc.h>
107 #include <sys/mbuf.h>
108 #include <sys/socket.h>
109 #include <sys/socketvar.h>
110 #include <sys/protosw.h>
111 #include <sys/errno.h>
112 #include <sys/kernel.h>
113 #include <sys/pool.h>
114 #if NRND > 0
115 #include <sys/md5.h>
116 #include <sys/rnd.h>
117 #endif
118
119 #include <net/route.h>
120 #include <net/if.h>
121
122 #include <netinet/in.h>
123 #include <netinet/in_systm.h>
124 #include <netinet/ip.h>
125 #include <netinet/in_pcb.h>
126 #include <netinet/ip_var.h>
127 #include <netinet/ip_icmp.h>
128
129 #ifdef INET6
130 #ifndef INET
131 #include <netinet/in.h>
132 #endif
133 #include <netinet/ip6.h>
134 #include <netinet6/in6_pcb.h>
135 #include <netinet6/ip6_var.h>
136 #include <netinet6/in6_var.h>
137 #include <netinet6/ip6protosw.h>
138 #include <netinet/icmp6.h>
139 #include <netinet6/nd6.h>
140 #endif
141
142 #include <netinet/tcp.h>
143 #include <netinet/tcp_fsm.h>
144 #include <netinet/tcp_seq.h>
145 #include <netinet/tcp_timer.h>
146 #include <netinet/tcp_var.h>
147 #include <netinet/tcp_private.h>
148 #include <netinet/tcp_congctl.h>
149 #include <netinet/tcpip.h>
150
151 #ifdef IPSEC
152 #include <netinet6/ipsec.h>
153 #include <netkey/key.h>
154 #endif /*IPSEC*/
155
156 #ifdef FAST_IPSEC
157 #include <netipsec/ipsec.h>
158 #include <netipsec/xform.h>
159 #ifdef INET6
160 #include <netipsec/ipsec6.h>
161 #endif
162 #include <netipsec/key.h>
163 #endif /* FAST_IPSEC*/
164
165
166 struct inpcbtable tcbtable; /* head of queue of active tcpcb's */
167 u_int32_t tcp_now; /* for RFC 1323 timestamps */
168
169 percpu_t *tcpstat_percpu;
170
171 /* patchable/settable parameters for tcp */
172 int tcp_mssdflt = TCP_MSS;
173 int tcp_minmss = TCP_MINMSS;
174 int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
175 int tcp_do_rfc1323 = 1; /* window scaling / timestamps (obsolete) */
176 #if NRND > 0
177 int tcp_do_rfc1948 = 0; /* ISS by cryptographic hash */
178 #endif
179 int tcp_do_sack = 1; /* selective acknowledgement */
180 int tcp_do_win_scale = 1; /* RFC1323 window scaling */
181 int tcp_do_timestamps = 1; /* RFC1323 timestamps */
182 int tcp_ack_on_push = 0; /* set to enable immediate ACK-on-PUSH */
183 int tcp_do_ecn = 0; /* Explicit Congestion Notification */
184 #ifndef TCP_INIT_WIN
185 #define TCP_INIT_WIN 0 /* initial slow start window */
186 #endif
187 #ifndef TCP_INIT_WIN_LOCAL
188 #define TCP_INIT_WIN_LOCAL 4 /* initial slow start window for local nets */
189 #endif
190 int tcp_init_win = TCP_INIT_WIN;
191 int tcp_init_win_local = TCP_INIT_WIN_LOCAL;
192 int tcp_mss_ifmtu = 0;
193 #ifdef TCP_COMPAT_42
194 int tcp_compat_42 = 1;
195 #else
196 int tcp_compat_42 = 0;
197 #endif
198 int tcp_rst_ppslim = 100; /* 100pps */
199 int tcp_ackdrop_ppslim = 100; /* 100pps */
200 int tcp_do_loopback_cksum = 0;
201 int tcp_do_abc = 1; /* RFC3465 Appropriate byte counting. */
202 int tcp_abc_aggressive = 1; /* 1: L=2*SMSS 0: L=1*SMSS */
203 int tcp_sack_tp_maxholes = 32;
204 int tcp_sack_globalmaxholes = 1024;
205 int tcp_sack_globalholes = 0;
206 int tcp_ecn_maxretries = 1;
207
208 /* tcb hash */
209 #ifndef TCBHASHSIZE
210 #define TCBHASHSIZE 128
211 #endif
212 int tcbhashsize = TCBHASHSIZE;
213
214 /* syn hash parameters */
215 #define TCP_SYN_HASH_SIZE 293
216 #define TCP_SYN_BUCKET_SIZE 35
217 int tcp_syn_cache_size = TCP_SYN_HASH_SIZE;
218 int tcp_syn_cache_limit = TCP_SYN_HASH_SIZE*TCP_SYN_BUCKET_SIZE;
219 int tcp_syn_bucket_limit = 3*TCP_SYN_BUCKET_SIZE;
220 struct syn_cache_head tcp_syn_cache[TCP_SYN_HASH_SIZE];
221
222 int tcp_freeq(struct tcpcb *);
223
224 #ifdef INET
225 void tcp_mtudisc_callback(struct in_addr);
226 #endif
227 #ifdef INET6
228 void tcp6_mtudisc_callback(struct in6_addr *);
229 #endif
230
231 #ifdef INET6
232 void tcp6_mtudisc(struct in6pcb *, int);
233 #endif
234
235 static struct pool tcpcb_pool;
236
237 #ifdef TCP_CSUM_COUNTERS
238 #include <sys/device.h>
239
240 #if defined(INET)
241 struct evcnt tcp_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
242 NULL, "tcp", "hwcsum bad");
243 struct evcnt tcp_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
244 NULL, "tcp", "hwcsum ok");
245 struct evcnt tcp_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
246 NULL, "tcp", "hwcsum data");
247 struct evcnt tcp_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
248 NULL, "tcp", "swcsum");
249
250 EVCNT_ATTACH_STATIC(tcp_hwcsum_bad);
251 EVCNT_ATTACH_STATIC(tcp_hwcsum_ok);
252 EVCNT_ATTACH_STATIC(tcp_hwcsum_data);
253 EVCNT_ATTACH_STATIC(tcp_swcsum);
254 #endif /* defined(INET) */
255
256 #if defined(INET6)
257 struct evcnt tcp6_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
258 NULL, "tcp6", "hwcsum bad");
259 struct evcnt tcp6_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
260 NULL, "tcp6", "hwcsum ok");
261 struct evcnt tcp6_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
262 NULL, "tcp6", "hwcsum data");
263 struct evcnt tcp6_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
264 NULL, "tcp6", "swcsum");
265
266 EVCNT_ATTACH_STATIC(tcp6_hwcsum_bad);
267 EVCNT_ATTACH_STATIC(tcp6_hwcsum_ok);
268 EVCNT_ATTACH_STATIC(tcp6_hwcsum_data);
269 EVCNT_ATTACH_STATIC(tcp6_swcsum);
270 #endif /* defined(INET6) */
271 #endif /* TCP_CSUM_COUNTERS */
272
273
274 #ifdef TCP_OUTPUT_COUNTERS
275 #include <sys/device.h>
276
277 struct evcnt tcp_output_bigheader = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
278 NULL, "tcp", "output big header");
279 struct evcnt tcp_output_predict_hit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
280 NULL, "tcp", "output predict hit");
281 struct evcnt tcp_output_predict_miss = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
282 NULL, "tcp", "output predict miss");
283 struct evcnt tcp_output_copysmall = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
284 NULL, "tcp", "output copy small");
285 struct evcnt tcp_output_copybig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
286 NULL, "tcp", "output copy big");
287 struct evcnt tcp_output_refbig = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
288 NULL, "tcp", "output reference big");
289
290 EVCNT_ATTACH_STATIC(tcp_output_bigheader);
291 EVCNT_ATTACH_STATIC(tcp_output_predict_hit);
292 EVCNT_ATTACH_STATIC(tcp_output_predict_miss);
293 EVCNT_ATTACH_STATIC(tcp_output_copysmall);
294 EVCNT_ATTACH_STATIC(tcp_output_copybig);
295 EVCNT_ATTACH_STATIC(tcp_output_refbig);
296
297 #endif /* TCP_OUTPUT_COUNTERS */
298
299 #ifdef TCP_REASS_COUNTERS
300 #include <sys/device.h>
301
302 struct evcnt tcp_reass_ = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
303 NULL, "tcp_reass", "calls");
304 struct evcnt tcp_reass_empty = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
305 &tcp_reass_, "tcp_reass", "insert into empty queue");
306 struct evcnt tcp_reass_iteration[8] = {
307 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", ">7 iterations"),
308 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "1 iteration"),
309 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "2 iterations"),
310 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "3 iterations"),
311 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "4 iterations"),
312 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "5 iterations"),
313 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "6 iterations"),
314 EVCNT_INITIALIZER(EVCNT_TYPE_MISC, &tcp_reass_, "tcp_reass", "7 iterations"),
315 };
316 struct evcnt tcp_reass_prependfirst = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
317 &tcp_reass_, "tcp_reass", "prepend to first");
318 struct evcnt tcp_reass_prepend = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
319 &tcp_reass_, "tcp_reass", "prepend");
320 struct evcnt tcp_reass_insert = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
321 &tcp_reass_, "tcp_reass", "insert");
322 struct evcnt tcp_reass_inserttail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
323 &tcp_reass_, "tcp_reass", "insert at tail");
324 struct evcnt tcp_reass_append = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
325 &tcp_reass_, "tcp_reass", "append");
326 struct evcnt tcp_reass_appendtail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
327 &tcp_reass_, "tcp_reass", "append to tail fragment");
328 struct evcnt tcp_reass_overlaptail = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
329 &tcp_reass_, "tcp_reass", "overlap at end");
330 struct evcnt tcp_reass_overlapfront = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
331 &tcp_reass_, "tcp_reass", "overlap at start");
332 struct evcnt tcp_reass_segdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
333 &tcp_reass_, "tcp_reass", "duplicate segment");
334 struct evcnt tcp_reass_fragdup = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
335 &tcp_reass_, "tcp_reass", "duplicate fragment");
336
337 EVCNT_ATTACH_STATIC(tcp_reass_);
338 EVCNT_ATTACH_STATIC(tcp_reass_empty);
339 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 0);
340 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 1);
341 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 2);
342 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 3);
343 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 4);
344 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 5);
345 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 6);
346 EVCNT_ATTACH_STATIC2(tcp_reass_iteration, 7);
347 EVCNT_ATTACH_STATIC(tcp_reass_prependfirst);
348 EVCNT_ATTACH_STATIC(tcp_reass_prepend);
349 EVCNT_ATTACH_STATIC(tcp_reass_insert);
350 EVCNT_ATTACH_STATIC(tcp_reass_inserttail);
351 EVCNT_ATTACH_STATIC(tcp_reass_append);
352 EVCNT_ATTACH_STATIC(tcp_reass_appendtail);
353 EVCNT_ATTACH_STATIC(tcp_reass_overlaptail);
354 EVCNT_ATTACH_STATIC(tcp_reass_overlapfront);
355 EVCNT_ATTACH_STATIC(tcp_reass_segdup);
356 EVCNT_ATTACH_STATIC(tcp_reass_fragdup);
357
358 #endif /* TCP_REASS_COUNTERS */
359
360 #ifdef MBUFTRACE
361 struct mowner tcp_mowner = MOWNER_INIT("tcp", "");
362 struct mowner tcp_rx_mowner = MOWNER_INIT("tcp", "rx");
363 struct mowner tcp_tx_mowner = MOWNER_INIT("tcp", "tx");
364 struct mowner tcp_sock_mowner = MOWNER_INIT("tcp", "sock");
365 struct mowner tcp_sock_rx_mowner = MOWNER_INIT("tcp", "sock rx");
366 struct mowner tcp_sock_tx_mowner = MOWNER_INIT("tcp", "sock tx");
367 #endif
368
369 /*
370 * Tcp initialization
371 */
372 void
373 tcp_init(void)
374 {
375 int hlen;
376
377 in_pcbinit(&tcbtable, tcbhashsize, tcbhashsize);
378 pool_init(&tcpcb_pool, sizeof(struct tcpcb), 0, 0, 0, "tcpcbpl",
379 NULL, IPL_SOFTNET);
380
381 hlen = sizeof(struct ip) + sizeof(struct tcphdr);
382 #ifdef INET6
383 if (sizeof(struct ip) < sizeof(struct ip6_hdr))
384 hlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
385 #endif
386 if (max_protohdr < hlen)
387 max_protohdr = hlen;
388 if (max_linkhdr + hlen > MHLEN)
389 panic("tcp_init");
390
391 #ifdef INET
392 icmp_mtudisc_callback_register(tcp_mtudisc_callback);
393 #endif
394 #ifdef INET6
395 icmp6_mtudisc_callback_register(tcp6_mtudisc_callback);
396 #endif
397
398 tcp_usrreq_init();
399
400 /* Initialize timer state. */
401 tcp_timer_init();
402
403 /* Initialize the compressed state engine. */
404 syn_cache_init();
405
406 /* Initialize the congestion control algorithms. */
407 tcp_congctl_init();
408
409 /* Initialize the TCPCB template. */
410 tcp_tcpcb_template();
411
412 /* Initialize reassembly queue */
413 tcpipqent_init();
414
415 /* SACK */
416 tcp_sack_init();
417
418 MOWNER_ATTACH(&tcp_tx_mowner);
419 MOWNER_ATTACH(&tcp_rx_mowner);
420 MOWNER_ATTACH(&tcp_reass_mowner);
421 MOWNER_ATTACH(&tcp_sock_mowner);
422 MOWNER_ATTACH(&tcp_sock_tx_mowner);
423 MOWNER_ATTACH(&tcp_sock_rx_mowner);
424 MOWNER_ATTACH(&tcp_mowner);
425
426 tcpstat_percpu = percpu_alloc(sizeof(uint64_t) * TCP_NSTATS);
427 }
428
429 /*
430 * Create template to be used to send tcp packets on a connection.
431 * Call after host entry created, allocates an mbuf and fills
432 * in a skeletal tcp/ip header, minimizing the amount of work
433 * necessary when the connection is used.
434 */
435 struct mbuf *
436 tcp_template(struct tcpcb *tp)
437 {
438 struct inpcb *inp = tp->t_inpcb;
439 #ifdef INET6
440 struct in6pcb *in6p = tp->t_in6pcb;
441 #endif
442 struct tcphdr *n;
443 struct mbuf *m;
444 int hlen;
445
446 switch (tp->t_family) {
447 case AF_INET:
448 hlen = sizeof(struct ip);
449 if (inp)
450 break;
451 #ifdef INET6
452 if (in6p) {
453 /* mapped addr case */
454 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr)
455 && IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr))
456 break;
457 }
458 #endif
459 return NULL; /*EINVAL*/
460 #ifdef INET6
461 case AF_INET6:
462 hlen = sizeof(struct ip6_hdr);
463 if (in6p) {
464 /* more sainty check? */
465 break;
466 }
467 return NULL; /*EINVAL*/
468 #endif
469 default:
470 hlen = 0; /*pacify gcc*/
471 return NULL; /*EAFNOSUPPORT*/
472 }
473 #ifdef DIAGNOSTIC
474 if (hlen + sizeof(struct tcphdr) > MCLBYTES)
475 panic("mclbytes too small for t_template");
476 #endif
477 m = tp->t_template;
478 if (m && m->m_len == hlen + sizeof(struct tcphdr))
479 ;
480 else {
481 if (m)
482 m_freem(m);
483 m = tp->t_template = NULL;
484 MGETHDR(m, M_DONTWAIT, MT_HEADER);
485 if (m && hlen + sizeof(struct tcphdr) > MHLEN) {
486 MCLGET(m, M_DONTWAIT);
487 if ((m->m_flags & M_EXT) == 0) {
488 m_free(m);
489 m = NULL;
490 }
491 }
492 if (m == NULL)
493 return NULL;
494 MCLAIM(m, &tcp_mowner);
495 m->m_pkthdr.len = m->m_len = hlen + sizeof(struct tcphdr);
496 }
497
498 memset(mtod(m, void *), 0, m->m_len);
499
500 n = (struct tcphdr *)(mtod(m, char *) + hlen);
501
502 switch (tp->t_family) {
503 case AF_INET:
504 {
505 struct ipovly *ipov;
506 mtod(m, struct ip *)->ip_v = 4;
507 mtod(m, struct ip *)->ip_hl = hlen >> 2;
508 ipov = mtod(m, struct ipovly *);
509 ipov->ih_pr = IPPROTO_TCP;
510 ipov->ih_len = htons(sizeof(struct tcphdr));
511 if (inp) {
512 ipov->ih_src = inp->inp_laddr;
513 ipov->ih_dst = inp->inp_faddr;
514 }
515 #ifdef INET6
516 else if (in6p) {
517 /* mapped addr case */
518 bcopy(&in6p->in6p_laddr.s6_addr32[3], &ipov->ih_src,
519 sizeof(ipov->ih_src));
520 bcopy(&in6p->in6p_faddr.s6_addr32[3], &ipov->ih_dst,
521 sizeof(ipov->ih_dst));
522 }
523 #endif
524 /*
525 * Compute the pseudo-header portion of the checksum
526 * now. We incrementally add in the TCP option and
527 * payload lengths later, and then compute the TCP
528 * checksum right before the packet is sent off onto
529 * the wire.
530 */
531 n->th_sum = in_cksum_phdr(ipov->ih_src.s_addr,
532 ipov->ih_dst.s_addr,
533 htons(sizeof(struct tcphdr) + IPPROTO_TCP));
534 break;
535 }
536 #ifdef INET6
537 case AF_INET6:
538 {
539 struct ip6_hdr *ip6;
540 mtod(m, struct ip *)->ip_v = 6;
541 ip6 = mtod(m, struct ip6_hdr *);
542 ip6->ip6_nxt = IPPROTO_TCP;
543 ip6->ip6_plen = htons(sizeof(struct tcphdr));
544 ip6->ip6_src = in6p->in6p_laddr;
545 ip6->ip6_dst = in6p->in6p_faddr;
546 ip6->ip6_flow = in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK;
547 if (ip6_auto_flowlabel) {
548 ip6->ip6_flow &= ~IPV6_FLOWLABEL_MASK;
549 ip6->ip6_flow |=
550 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
551 }
552 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
553 ip6->ip6_vfc |= IPV6_VERSION;
554
555 /*
556 * Compute the pseudo-header portion of the checksum
557 * now. We incrementally add in the TCP option and
558 * payload lengths later, and then compute the TCP
559 * checksum right before the packet is sent off onto
560 * the wire.
561 */
562 n->th_sum = in6_cksum_phdr(&in6p->in6p_laddr,
563 &in6p->in6p_faddr, htonl(sizeof(struct tcphdr)),
564 htonl(IPPROTO_TCP));
565 break;
566 }
567 #endif
568 }
569 if (inp) {
570 n->th_sport = inp->inp_lport;
571 n->th_dport = inp->inp_fport;
572 }
573 #ifdef INET6
574 else if (in6p) {
575 n->th_sport = in6p->in6p_lport;
576 n->th_dport = in6p->in6p_fport;
577 }
578 #endif
579 n->th_seq = 0;
580 n->th_ack = 0;
581 n->th_x2 = 0;
582 n->th_off = 5;
583 n->th_flags = 0;
584 n->th_win = 0;
585 n->th_urp = 0;
586 return (m);
587 }
588
589 /*
590 * Send a single message to the TCP at address specified by
591 * the given TCP/IP header. If m == 0, then we make a copy
592 * of the tcpiphdr at ti and send directly to the addressed host.
593 * This is used to force keep alive messages out using the TCP
594 * template for a connection tp->t_template. If flags are given
595 * then we send a message back to the TCP which originated the
596 * segment ti, and discard the mbuf containing it and any other
597 * attached mbufs.
598 *
599 * In any case the ack and sequence number of the transmitted
600 * segment are as specified by the parameters.
601 */
602 int
603 tcp_respond(struct tcpcb *tp, struct mbuf *template, struct mbuf *m,
604 struct tcphdr *th0, tcp_seq ack, tcp_seq seq, int flags)
605 {
606 #ifdef INET6
607 struct rtentry *rt;
608 #endif
609 struct route *ro;
610 int error, tlen, win = 0;
611 int hlen;
612 struct ip *ip;
613 #ifdef INET6
614 struct ip6_hdr *ip6;
615 #endif
616 int family; /* family on packet, not inpcb/in6pcb! */
617 struct tcphdr *th;
618 struct socket *so;
619
620 if (tp != NULL && (flags & TH_RST) == 0) {
621 #ifdef DIAGNOSTIC
622 if (tp->t_inpcb && tp->t_in6pcb)
623 panic("tcp_respond: both t_inpcb and t_in6pcb are set");
624 #endif
625 #ifdef INET
626 if (tp->t_inpcb)
627 win = sbspace(&tp->t_inpcb->inp_socket->so_rcv);
628 #endif
629 #ifdef INET6
630 if (tp->t_in6pcb)
631 win = sbspace(&tp->t_in6pcb->in6p_socket->so_rcv);
632 #endif
633 }
634
635 th = NULL; /* Quell uninitialized warning */
636 ip = NULL;
637 #ifdef INET6
638 ip6 = NULL;
639 #endif
640 if (m == 0) {
641 if (!template)
642 return EINVAL;
643
644 /* get family information from template */
645 switch (mtod(template, struct ip *)->ip_v) {
646 case 4:
647 family = AF_INET;
648 hlen = sizeof(struct ip);
649 break;
650 #ifdef INET6
651 case 6:
652 family = AF_INET6;
653 hlen = sizeof(struct ip6_hdr);
654 break;
655 #endif
656 default:
657 return EAFNOSUPPORT;
658 }
659
660 MGETHDR(m, M_DONTWAIT, MT_HEADER);
661 if (m) {
662 MCLAIM(m, &tcp_tx_mowner);
663 MCLGET(m, M_DONTWAIT);
664 if ((m->m_flags & M_EXT) == 0) {
665 m_free(m);
666 m = NULL;
667 }
668 }
669 if (m == NULL)
670 return (ENOBUFS);
671
672 if (tcp_compat_42)
673 tlen = 1;
674 else
675 tlen = 0;
676
677 m->m_data += max_linkhdr;
678 bcopy(mtod(template, void *), mtod(m, void *),
679 template->m_len);
680 switch (family) {
681 case AF_INET:
682 ip = mtod(m, struct ip *);
683 th = (struct tcphdr *)(ip + 1);
684 break;
685 #ifdef INET6
686 case AF_INET6:
687 ip6 = mtod(m, struct ip6_hdr *);
688 th = (struct tcphdr *)(ip6 + 1);
689 break;
690 #endif
691 #if 0
692 default:
693 /* noone will visit here */
694 m_freem(m);
695 return EAFNOSUPPORT;
696 #endif
697 }
698 flags = TH_ACK;
699 } else {
700
701 if ((m->m_flags & M_PKTHDR) == 0) {
702 #if 0
703 printf("non PKTHDR to tcp_respond\n");
704 #endif
705 m_freem(m);
706 return EINVAL;
707 }
708 #ifdef DIAGNOSTIC
709 if (!th0)
710 panic("th0 == NULL in tcp_respond");
711 #endif
712
713 /* get family information from m */
714 switch (mtod(m, struct ip *)->ip_v) {
715 case 4:
716 family = AF_INET;
717 hlen = sizeof(struct ip);
718 ip = mtod(m, struct ip *);
719 break;
720 #ifdef INET6
721 case 6:
722 family = AF_INET6;
723 hlen = sizeof(struct ip6_hdr);
724 ip6 = mtod(m, struct ip6_hdr *);
725 break;
726 #endif
727 default:
728 m_freem(m);
729 return EAFNOSUPPORT;
730 }
731 /* clear h/w csum flags inherited from rx packet */
732 m->m_pkthdr.csum_flags = 0;
733
734 if ((flags & TH_SYN) == 0 || sizeof(*th0) > (th0->th_off << 2))
735 tlen = sizeof(*th0);
736 else
737 tlen = th0->th_off << 2;
738
739 if (m->m_len > hlen + tlen && (m->m_flags & M_EXT) == 0 &&
740 mtod(m, char *) + hlen == (char *)th0) {
741 m->m_len = hlen + tlen;
742 m_freem(m->m_next);
743 m->m_next = NULL;
744 } else {
745 struct mbuf *n;
746
747 #ifdef DIAGNOSTIC
748 if (max_linkhdr + hlen + tlen > MCLBYTES) {
749 m_freem(m);
750 return EMSGSIZE;
751 }
752 #endif
753 MGETHDR(n, M_DONTWAIT, MT_HEADER);
754 if (n && max_linkhdr + hlen + tlen > MHLEN) {
755 MCLGET(n, M_DONTWAIT);
756 if ((n->m_flags & M_EXT) == 0) {
757 m_freem(n);
758 n = NULL;
759 }
760 }
761 if (!n) {
762 m_freem(m);
763 return ENOBUFS;
764 }
765
766 MCLAIM(n, &tcp_tx_mowner);
767 n->m_data += max_linkhdr;
768 n->m_len = hlen + tlen;
769 m_copyback(n, 0, hlen, mtod(m, void *));
770 m_copyback(n, hlen, tlen, (void *)th0);
771
772 m_freem(m);
773 m = n;
774 n = NULL;
775 }
776
777 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
778 switch (family) {
779 case AF_INET:
780 ip = mtod(m, struct ip *);
781 th = (struct tcphdr *)(ip + 1);
782 ip->ip_p = IPPROTO_TCP;
783 xchg(ip->ip_dst, ip->ip_src, struct in_addr);
784 ip->ip_p = IPPROTO_TCP;
785 break;
786 #ifdef INET6
787 case AF_INET6:
788 ip6 = mtod(m, struct ip6_hdr *);
789 th = (struct tcphdr *)(ip6 + 1);
790 ip6->ip6_nxt = IPPROTO_TCP;
791 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
792 ip6->ip6_nxt = IPPROTO_TCP;
793 break;
794 #endif
795 #if 0
796 default:
797 /* noone will visit here */
798 m_freem(m);
799 return EAFNOSUPPORT;
800 #endif
801 }
802 xchg(th->th_dport, th->th_sport, u_int16_t);
803 #undef xchg
804 tlen = 0; /*be friendly with the following code*/
805 }
806 th->th_seq = htonl(seq);
807 th->th_ack = htonl(ack);
808 th->th_x2 = 0;
809 if ((flags & TH_SYN) == 0) {
810 if (tp)
811 win >>= tp->rcv_scale;
812 if (win > TCP_MAXWIN)
813 win = TCP_MAXWIN;
814 th->th_win = htons((u_int16_t)win);
815 th->th_off = sizeof (struct tcphdr) >> 2;
816 tlen += sizeof(*th);
817 } else
818 tlen += th->th_off << 2;
819 m->m_len = hlen + tlen;
820 m->m_pkthdr.len = hlen + tlen;
821 m->m_pkthdr.rcvif = (struct ifnet *) 0;
822 th->th_flags = flags;
823 th->th_urp = 0;
824
825 switch (family) {
826 #ifdef INET
827 case AF_INET:
828 {
829 struct ipovly *ipov = (struct ipovly *)ip;
830 memset(ipov->ih_x1, 0, sizeof ipov->ih_x1);
831 ipov->ih_len = htons((u_int16_t)tlen);
832
833 th->th_sum = 0;
834 th->th_sum = in_cksum(m, hlen + tlen);
835 ip->ip_len = htons(hlen + tlen);
836 ip->ip_ttl = ip_defttl;
837 break;
838 }
839 #endif
840 #ifdef INET6
841 case AF_INET6:
842 {
843 th->th_sum = 0;
844 th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr),
845 tlen);
846 ip6->ip6_plen = htons(tlen);
847 if (tp && tp->t_in6pcb) {
848 struct ifnet *oifp;
849 ro = &tp->t_in6pcb->in6p_route;
850 oifp = (rt = rtcache_validate(ro)) != NULL ? rt->rt_ifp
851 : NULL;
852 ip6->ip6_hlim = in6_selecthlim(tp->t_in6pcb, oifp);
853 } else
854 ip6->ip6_hlim = ip6_defhlim;
855 ip6->ip6_flow &= ~IPV6_FLOWINFO_MASK;
856 if (ip6_auto_flowlabel) {
857 ip6->ip6_flow |=
858 (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
859 }
860 break;
861 }
862 #endif
863 }
864
865 if (tp && tp->t_inpcb)
866 so = tp->t_inpcb->inp_socket;
867 #ifdef INET6
868 else if (tp && tp->t_in6pcb)
869 so = tp->t_in6pcb->in6p_socket;
870 #endif
871 else
872 so = NULL;
873
874 if (tp != NULL && tp->t_inpcb != NULL) {
875 ro = &tp->t_inpcb->inp_route;
876 #ifdef DIAGNOSTIC
877 if (family != AF_INET)
878 panic("tcp_respond: address family mismatch");
879 if (!in_hosteq(ip->ip_dst, tp->t_inpcb->inp_faddr)) {
880 panic("tcp_respond: ip_dst %x != inp_faddr %x",
881 ntohl(ip->ip_dst.s_addr),
882 ntohl(tp->t_inpcb->inp_faddr.s_addr));
883 }
884 #endif
885 }
886 #ifdef INET6
887 else if (tp != NULL && tp->t_in6pcb != NULL) {
888 ro = (struct route *)&tp->t_in6pcb->in6p_route;
889 #ifdef DIAGNOSTIC
890 if (family == AF_INET) {
891 if (!IN6_IS_ADDR_V4MAPPED(&tp->t_in6pcb->in6p_faddr))
892 panic("tcp_respond: not mapped addr");
893 if (memcmp(&ip->ip_dst,
894 &tp->t_in6pcb->in6p_faddr.s6_addr32[3],
895 sizeof(ip->ip_dst)) != 0) {
896 panic("tcp_respond: ip_dst != in6p_faddr");
897 }
898 } else if (family == AF_INET6) {
899 if (!IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
900 &tp->t_in6pcb->in6p_faddr))
901 panic("tcp_respond: ip6_dst != in6p_faddr");
902 } else
903 panic("tcp_respond: address family mismatch");
904 #endif
905 }
906 #endif
907 else
908 ro = NULL;
909
910 switch (family) {
911 #ifdef INET
912 case AF_INET:
913 error = ip_output(m, NULL, ro,
914 (tp && tp->t_mtudisc ? IP_MTUDISC : 0),
915 (struct ip_moptions *)0, so);
916 break;
917 #endif
918 #ifdef INET6
919 case AF_INET6:
920 error = ip6_output(m, NULL, ro, 0, NULL, so, NULL);
921 break;
922 #endif
923 default:
924 error = EAFNOSUPPORT;
925 break;
926 }
927
928 return (error);
929 }
930
931 /*
932 * Template TCPCB. Rather than zeroing a new TCPCB and initializing
933 * a bunch of members individually, we maintain this template for the
934 * static and mostly-static components of the TCPCB, and copy it into
935 * the new TCPCB instead.
936 */
937 static struct tcpcb tcpcb_template = {
938 .t_srtt = TCPTV_SRTTBASE,
939 .t_rttmin = TCPTV_MIN,
940
941 .snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT,
942 .snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT,
943 .snd_numholes = 0,
944
945 .t_partialacks = -1,
946 .t_bytes_acked = 0,
947 };
948
949 /*
950 * Updates the TCPCB template whenever a parameter that would affect
951 * the template is changed.
952 */
953 void
954 tcp_tcpcb_template(void)
955 {
956 struct tcpcb *tp = &tcpcb_template;
957 int flags;
958
959 tp->t_peermss = tcp_mssdflt;
960 tp->t_ourmss = tcp_mssdflt;
961 tp->t_segsz = tcp_mssdflt;
962
963 flags = 0;
964 if (tcp_do_rfc1323 && tcp_do_win_scale)
965 flags |= TF_REQ_SCALE;
966 if (tcp_do_rfc1323 && tcp_do_timestamps)
967 flags |= TF_REQ_TSTMP;
968 tp->t_flags = flags;
969
970 /*
971 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
972 * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives
973 * reasonable initial retransmit time.
974 */
975 tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << (TCP_RTTVAR_SHIFT + 2 - 1);
976 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
977 TCPTV_MIN, TCPTV_REXMTMAX);
978
979 /* Keep Alive */
980 tp->t_keepinit = tcp_keepinit;
981 tp->t_keepidle = tcp_keepidle;
982 tp->t_keepintvl = tcp_keepintvl;
983 tp->t_keepcnt = tcp_keepcnt;
984 tp->t_maxidle = tp->t_keepcnt * tp->t_keepintvl;
985 }
986
987 /*
988 * Create a new TCP control block, making an
989 * empty reassembly queue and hooking it to the argument
990 * protocol control block.
991 */
992 /* family selects inpcb, or in6pcb */
993 struct tcpcb *
994 tcp_newtcpcb(int family, void *aux)
995 {
996 #ifdef INET6
997 struct rtentry *rt;
998 #endif
999 struct tcpcb *tp;
1000 int i;
1001
1002 /* XXX Consider using a pool_cache for speed. */
1003 tp = pool_get(&tcpcb_pool, PR_NOWAIT); /* splsoftnet via tcp_usrreq */
1004 if (tp == NULL)
1005 return (NULL);
1006 memcpy(tp, &tcpcb_template, sizeof(*tp));
1007 TAILQ_INIT(&tp->segq);
1008 TAILQ_INIT(&tp->timeq);
1009 tp->t_family = family; /* may be overridden later on */
1010 TAILQ_INIT(&tp->snd_holes);
1011 LIST_INIT(&tp->t_sc); /* XXX can template this */
1012
1013 /* Don't sweat this loop; hopefully the compiler will unroll it. */
1014 for (i = 0; i < TCPT_NTIMERS; i++) {
1015 callout_init(&tp->t_timer[i], CALLOUT_MPSAFE);
1016 TCP_TIMER_INIT(tp, i);
1017 }
1018 callout_init(&tp->t_delack_ch, CALLOUT_MPSAFE);
1019
1020 switch (family) {
1021 case AF_INET:
1022 {
1023 struct inpcb *inp = (struct inpcb *)aux;
1024
1025 inp->inp_ip.ip_ttl = ip_defttl;
1026 inp->inp_ppcb = (void *)tp;
1027
1028 tp->t_inpcb = inp;
1029 tp->t_mtudisc = ip_mtudisc;
1030 break;
1031 }
1032 #ifdef INET6
1033 case AF_INET6:
1034 {
1035 struct in6pcb *in6p = (struct in6pcb *)aux;
1036
1037 in6p->in6p_ip6.ip6_hlim = in6_selecthlim(in6p,
1038 (rt = rtcache_validate(&in6p->in6p_route)) != NULL
1039 ? rt->rt_ifp
1040 : NULL);
1041 in6p->in6p_ppcb = (void *)tp;
1042
1043 tp->t_in6pcb = in6p;
1044 /* for IPv6, always try to run path MTU discovery */
1045 tp->t_mtudisc = 1;
1046 break;
1047 }
1048 #endif /* INET6 */
1049 default:
1050 for (i = 0; i < TCPT_NTIMERS; i++)
1051 callout_destroy(&tp->t_timer[i]);
1052 callout_destroy(&tp->t_delack_ch);
1053 pool_put(&tcpcb_pool, tp); /* splsoftnet via tcp_usrreq */
1054 return (NULL);
1055 }
1056
1057 /*
1058 * Initialize our timebase. When we send timestamps, we take
1059 * the delta from tcp_now -- this means each connection always
1060 * gets a timebase of 1, which makes it, among other things,
1061 * more difficult to determine how long a system has been up,
1062 * and thus how many TCP sequence increments have occurred.
1063 *
1064 * We start with 1, because 0 doesn't work with linux, which
1065 * considers timestamp 0 in a SYN packet as a bug and disables
1066 * timestamps.
1067 */
1068 tp->ts_timebase = tcp_now - 1;
1069
1070 tcp_congctl_select(tp, tcp_congctl_global_name);
1071
1072 return (tp);
1073 }
1074
1075 /*
1076 * Drop a TCP connection, reporting
1077 * the specified error. If connection is synchronized,
1078 * then send a RST to peer.
1079 */
1080 struct tcpcb *
1081 tcp_drop(struct tcpcb *tp, int errno)
1082 {
1083 struct socket *so = NULL;
1084
1085 #ifdef DIAGNOSTIC
1086 if (tp->t_inpcb && tp->t_in6pcb)
1087 panic("tcp_drop: both t_inpcb and t_in6pcb are set");
1088 #endif
1089 #ifdef INET
1090 if (tp->t_inpcb)
1091 so = tp->t_inpcb->inp_socket;
1092 #endif
1093 #ifdef INET6
1094 if (tp->t_in6pcb)
1095 so = tp->t_in6pcb->in6p_socket;
1096 #endif
1097 if (!so)
1098 return NULL;
1099
1100 if (TCPS_HAVERCVDSYN(tp->t_state)) {
1101 tp->t_state = TCPS_CLOSED;
1102 (void) tcp_output(tp);
1103 TCP_STATINC(TCP_STAT_DROPS);
1104 } else
1105 TCP_STATINC(TCP_STAT_CONNDROPS);
1106 if (errno == ETIMEDOUT && tp->t_softerror)
1107 errno = tp->t_softerror;
1108 so->so_error = errno;
1109 return (tcp_close(tp));
1110 }
1111
1112 /*
1113 * Close a TCP control block:
1114 * discard all space held by the tcp
1115 * discard internet protocol block
1116 * wake up any sleepers
1117 */
1118 struct tcpcb *
1119 tcp_close(struct tcpcb *tp)
1120 {
1121 struct inpcb *inp;
1122 #ifdef INET6
1123 struct in6pcb *in6p;
1124 #endif
1125 struct socket *so;
1126 #ifdef RTV_RTT
1127 struct rtentry *rt;
1128 #endif
1129 struct route *ro;
1130 int j;
1131
1132 inp = tp->t_inpcb;
1133 #ifdef INET6
1134 in6p = tp->t_in6pcb;
1135 #endif
1136 so = NULL;
1137 ro = NULL;
1138 if (inp) {
1139 so = inp->inp_socket;
1140 ro = &inp->inp_route;
1141 }
1142 #ifdef INET6
1143 else if (in6p) {
1144 so = in6p->in6p_socket;
1145 ro = (struct route *)&in6p->in6p_route;
1146 }
1147 #endif
1148
1149 #ifdef RTV_RTT
1150 /*
1151 * If we sent enough data to get some meaningful characteristics,
1152 * save them in the routing entry. 'Enough' is arbitrarily
1153 * defined as the sendpipesize (default 4K) * 16. This would
1154 * give us 16 rtt samples assuming we only get one sample per
1155 * window (the usual case on a long haul net). 16 samples is
1156 * enough for the srtt filter to converge to within 5% of the correct
1157 * value; fewer samples and we could save a very bogus rtt.
1158 *
1159 * Don't update the default route's characteristics and don't
1160 * update anything that the user "locked".
1161 */
1162 if (SEQ_LT(tp->iss + so->so_snd.sb_hiwat * 16, tp->snd_max) &&
1163 ro && (rt = rtcache_validate(ro)) != NULL &&
1164 !in_nullhost(satocsin(rt_getkey(rt))->sin_addr)) {
1165 u_long i = 0;
1166
1167 if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) {
1168 i = tp->t_srtt *
1169 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2));
1170 if (rt->rt_rmx.rmx_rtt && i)
1171 /*
1172 * filter this update to half the old & half
1173 * the new values, converting scale.
1174 * See route.h and tcp_var.h for a
1175 * description of the scaling constants.
1176 */
1177 rt->rt_rmx.rmx_rtt =
1178 (rt->rt_rmx.rmx_rtt + i) / 2;
1179 else
1180 rt->rt_rmx.rmx_rtt = i;
1181 }
1182 if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) {
1183 i = tp->t_rttvar *
1184 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTTVAR_SHIFT + 2));
1185 if (rt->rt_rmx.rmx_rttvar && i)
1186 rt->rt_rmx.rmx_rttvar =
1187 (rt->rt_rmx.rmx_rttvar + i) / 2;
1188 else
1189 rt->rt_rmx.rmx_rttvar = i;
1190 }
1191 /*
1192 * update the pipelimit (ssthresh) if it has been updated
1193 * already or if a pipesize was specified & the threshhold
1194 * got below half the pipesize. I.e., wait for bad news
1195 * before we start updating, then update on both good
1196 * and bad news.
1197 */
1198 if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 &&
1199 (i = tp->snd_ssthresh) && rt->rt_rmx.rmx_ssthresh) ||
1200 i < (rt->rt_rmx.rmx_sendpipe / 2)) {
1201 /*
1202 * convert the limit from user data bytes to
1203 * packets then to packet data bytes.
1204 */
1205 i = (i + tp->t_segsz / 2) / tp->t_segsz;
1206 if (i < 2)
1207 i = 2;
1208 i *= (u_long)(tp->t_segsz + sizeof (struct tcpiphdr));
1209 if (rt->rt_rmx.rmx_ssthresh)
1210 rt->rt_rmx.rmx_ssthresh =
1211 (rt->rt_rmx.rmx_ssthresh + i) / 2;
1212 else
1213 rt->rt_rmx.rmx_ssthresh = i;
1214 }
1215 }
1216 #endif /* RTV_RTT */
1217 /* free the reassembly queue, if any */
1218 TCP_REASS_LOCK(tp);
1219 (void) tcp_freeq(tp);
1220 TCP_REASS_UNLOCK(tp);
1221
1222 /* free the SACK holes list. */
1223 tcp_free_sackholes(tp);
1224 tcp_congctl_release(tp);
1225 syn_cache_cleanup(tp);
1226
1227 if (tp->t_template) {
1228 m_free(tp->t_template);
1229 tp->t_template = NULL;
1230 }
1231
1232 /*
1233 * Detaching the pcb will unlock the socket/tcpcb, and stopping
1234 * the timers can also drop the lock. We need to prevent access
1235 * to the tcpcb as it's half torn down. Flag the pcb as dead
1236 * (prevents access by timers) and only then detach it.
1237 */
1238 tp->t_flags |= TF_DEAD;
1239 if (inp) {
1240 inp->inp_ppcb = 0;
1241 soisdisconnected(so);
1242 in_pcbdetach(inp);
1243 }
1244 #ifdef INET6
1245 else if (in6p) {
1246 in6p->in6p_ppcb = 0;
1247 soisdisconnected(so);
1248 in6_pcbdetach(in6p);
1249 }
1250 #endif
1251 /*
1252 * pcb is no longer visble elsewhere, so we can safely release
1253 * the lock in callout_halt() if needed.
1254 */
1255 TCP_STATINC(TCP_STAT_CLOSED);
1256 for (j = 0; j < TCPT_NTIMERS; j++) {
1257 callout_halt(&tp->t_timer[j], softnet_lock);
1258 callout_destroy(&tp->t_timer[j]);
1259 }
1260 callout_halt(&tp->t_delack_ch, softnet_lock);
1261 callout_destroy(&tp->t_delack_ch);
1262 pool_put(&tcpcb_pool, tp);
1263
1264 return ((struct tcpcb *)0);
1265 }
1266
1267 int
1268 tcp_freeq(struct tcpcb *tp)
1269 {
1270 struct ipqent *qe;
1271 int rv = 0;
1272 #ifdef TCPREASS_DEBUG
1273 int i = 0;
1274 #endif
1275
1276 TCP_REASS_LOCK_CHECK(tp);
1277
1278 while ((qe = TAILQ_FIRST(&tp->segq)) != NULL) {
1279 #ifdef TCPREASS_DEBUG
1280 printf("tcp_freeq[%p,%d]: %u:%u(%u) 0x%02x\n",
1281 tp, i++, qe->ipqe_seq, qe->ipqe_seq + qe->ipqe_len,
1282 qe->ipqe_len, qe->ipqe_flags & (TH_SYN|TH_FIN|TH_RST));
1283 #endif
1284 TAILQ_REMOVE(&tp->segq, qe, ipqe_q);
1285 TAILQ_REMOVE(&tp->timeq, qe, ipqe_timeq);
1286 m_freem(qe->ipqe_m);
1287 tcpipqent_free(qe);
1288 rv = 1;
1289 }
1290 tp->t_segqlen = 0;
1291 KASSERT(TAILQ_EMPTY(&tp->timeq));
1292 return (rv);
1293 }
1294
1295 /*
1296 * Protocol drain routine. Called when memory is in short supply.
1297 * Don't acquire softnet_lock as can be called from hardware
1298 * interrupt handler.
1299 */
1300 void
1301 tcp_drain(void)
1302 {
1303 struct inpcb_hdr *inph;
1304 struct tcpcb *tp;
1305
1306 KERNEL_LOCK(1, NULL);
1307
1308 /*
1309 * Free the sequence queue of all TCP connections.
1310 */
1311 CIRCLEQ_FOREACH(inph, &tcbtable.inpt_queue, inph_queue) {
1312 switch (inph->inph_af) {
1313 case AF_INET:
1314 tp = intotcpcb((struct inpcb *)inph);
1315 break;
1316 #ifdef INET6
1317 case AF_INET6:
1318 tp = in6totcpcb((struct in6pcb *)inph);
1319 break;
1320 #endif
1321 default:
1322 tp = NULL;
1323 break;
1324 }
1325 if (tp != NULL) {
1326 /*
1327 * We may be called from a device's interrupt
1328 * context. If the tcpcb is already busy,
1329 * just bail out now.
1330 */
1331 if (tcp_reass_lock_try(tp) == 0)
1332 continue;
1333 if (tcp_freeq(tp))
1334 TCP_STATINC(TCP_STAT_CONNSDRAINED);
1335 TCP_REASS_UNLOCK(tp);
1336 }
1337 }
1338
1339 KERNEL_UNLOCK_ONE(NULL);
1340 }
1341
1342 /*
1343 * Notify a tcp user of an asynchronous error;
1344 * store error as soft error, but wake up user
1345 * (for now, won't do anything until can select for soft error).
1346 */
1347 void
1348 tcp_notify(struct inpcb *inp, int error)
1349 {
1350 struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb;
1351 struct socket *so = inp->inp_socket;
1352
1353 /*
1354 * Ignore some errors if we are hooked up.
1355 * If connection hasn't completed, has retransmitted several times,
1356 * and receives a second error, give up now. This is better
1357 * than waiting a long time to establish a connection that
1358 * can never complete.
1359 */
1360 if (tp->t_state == TCPS_ESTABLISHED &&
1361 (error == EHOSTUNREACH || error == ENETUNREACH ||
1362 error == EHOSTDOWN)) {
1363 return;
1364 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 &&
1365 tp->t_rxtshift > 3 && tp->t_softerror)
1366 so->so_error = error;
1367 else
1368 tp->t_softerror = error;
1369 cv_broadcast(&so->so_cv);
1370 sorwakeup(so);
1371 sowwakeup(so);
1372 }
1373
1374 #ifdef INET6
1375 void
1376 tcp6_notify(struct in6pcb *in6p, int error)
1377 {
1378 struct tcpcb *tp = (struct tcpcb *)in6p->in6p_ppcb;
1379 struct socket *so = in6p->in6p_socket;
1380
1381 /*
1382 * Ignore some errors if we are hooked up.
1383 * If connection hasn't completed, has retransmitted several times,
1384 * and receives a second error, give up now. This is better
1385 * than waiting a long time to establish a connection that
1386 * can never complete.
1387 */
1388 if (tp->t_state == TCPS_ESTABLISHED &&
1389 (error == EHOSTUNREACH || error == ENETUNREACH ||
1390 error == EHOSTDOWN)) {
1391 return;
1392 } else if (TCPS_HAVEESTABLISHED(tp->t_state) == 0 &&
1393 tp->t_rxtshift > 3 && tp->t_softerror)
1394 so->so_error = error;
1395 else
1396 tp->t_softerror = error;
1397 cv_broadcast(&so->so_cv);
1398 sorwakeup(so);
1399 sowwakeup(so);
1400 }
1401 #endif
1402
1403 #ifdef INET6
1404 void *
1405 tcp6_ctlinput(int cmd, const struct sockaddr *sa, void *d)
1406 {
1407 struct tcphdr th;
1408 void (*notify)(struct in6pcb *, int) = tcp6_notify;
1409 int nmatch;
1410 struct ip6_hdr *ip6;
1411 const struct sockaddr_in6 *sa6_src = NULL;
1412 const struct sockaddr_in6 *sa6 = (const struct sockaddr_in6 *)sa;
1413 struct mbuf *m;
1414 int off;
1415
1416 if (sa->sa_family != AF_INET6 ||
1417 sa->sa_len != sizeof(struct sockaddr_in6))
1418 return NULL;
1419 if ((unsigned)cmd >= PRC_NCMDS)
1420 return NULL;
1421 else if (cmd == PRC_QUENCH) {
1422 /*
1423 * Don't honor ICMP Source Quench messages meant for
1424 * TCP connections.
1425 */
1426 return NULL;
1427 } else if (PRC_IS_REDIRECT(cmd))
1428 notify = in6_rtchange, d = NULL;
1429 else if (cmd == PRC_MSGSIZE)
1430 ; /* special code is present, see below */
1431 else if (cmd == PRC_HOSTDEAD)
1432 d = NULL;
1433 else if (inet6ctlerrmap[cmd] == 0)
1434 return NULL;
1435
1436 /* if the parameter is from icmp6, decode it. */
1437 if (d != NULL) {
1438 struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d;
1439 m = ip6cp->ip6c_m;
1440 ip6 = ip6cp->ip6c_ip6;
1441 off = ip6cp->ip6c_off;
1442 sa6_src = ip6cp->ip6c_src;
1443 } else {
1444 m = NULL;
1445 ip6 = NULL;
1446 sa6_src = &sa6_any;
1447 off = 0;
1448 }
1449
1450 if (ip6) {
1451 /*
1452 * XXX: We assume that when ip6 is non NULL,
1453 * M and OFF are valid.
1454 */
1455
1456 /* check if we can safely examine src and dst ports */
1457 if (m->m_pkthdr.len < off + sizeof(th)) {
1458 if (cmd == PRC_MSGSIZE)
1459 icmp6_mtudisc_update((struct ip6ctlparam *)d, 0);
1460 return NULL;
1461 }
1462
1463 memset(&th, 0, sizeof(th));
1464 m_copydata(m, off, sizeof(th), (void *)&th);
1465
1466 if (cmd == PRC_MSGSIZE) {
1467 int valid = 0;
1468
1469 /*
1470 * Check to see if we have a valid TCP connection
1471 * corresponding to the address in the ICMPv6 message
1472 * payload.
1473 */
1474 if (in6_pcblookup_connect(&tcbtable, &sa6->sin6_addr,
1475 th.th_dport,
1476 (const struct in6_addr *)&sa6_src->sin6_addr,
1477 th.th_sport, 0))
1478 valid++;
1479
1480 /*
1481 * Depending on the value of "valid" and routing table
1482 * size (mtudisc_{hi,lo}wat), we will:
1483 * - recalcurate the new MTU and create the
1484 * corresponding routing entry, or
1485 * - ignore the MTU change notification.
1486 */
1487 icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1488
1489 /*
1490 * no need to call in6_pcbnotify, it should have been
1491 * called via callback if necessary
1492 */
1493 return NULL;
1494 }
1495
1496 nmatch = in6_pcbnotify(&tcbtable, sa, th.th_dport,
1497 (const struct sockaddr *)sa6_src, th.th_sport, cmd, NULL, notify);
1498 if (nmatch == 0 && syn_cache_count &&
1499 (inet6ctlerrmap[cmd] == EHOSTUNREACH ||
1500 inet6ctlerrmap[cmd] == ENETUNREACH ||
1501 inet6ctlerrmap[cmd] == EHOSTDOWN))
1502 syn_cache_unreach((const struct sockaddr *)sa6_src,
1503 sa, &th);
1504 } else {
1505 (void) in6_pcbnotify(&tcbtable, sa, 0,
1506 (const struct sockaddr *)sa6_src, 0, cmd, NULL, notify);
1507 }
1508
1509 return NULL;
1510 }
1511 #endif
1512
1513 #ifdef INET
1514 /* assumes that ip header and tcp header are contiguous on mbuf */
1515 void *
1516 tcp_ctlinput(int cmd, const struct sockaddr *sa, void *v)
1517 {
1518 struct ip *ip = v;
1519 struct tcphdr *th;
1520 struct icmp *icp;
1521 extern const int inetctlerrmap[];
1522 void (*notify)(struct inpcb *, int) = tcp_notify;
1523 int errno;
1524 int nmatch;
1525 struct tcpcb *tp;
1526 u_int mtu;
1527 tcp_seq seq;
1528 struct inpcb *inp;
1529 #ifdef INET6
1530 struct in6pcb *in6p;
1531 struct in6_addr src6, dst6;
1532 #endif
1533
1534 if (sa->sa_family != AF_INET ||
1535 sa->sa_len != sizeof(struct sockaddr_in))
1536 return NULL;
1537 if ((unsigned)cmd >= PRC_NCMDS)
1538 return NULL;
1539 errno = inetctlerrmap[cmd];
1540 if (cmd == PRC_QUENCH)
1541 /*
1542 * Don't honor ICMP Source Quench messages meant for
1543 * TCP connections.
1544 */
1545 return NULL;
1546 else if (PRC_IS_REDIRECT(cmd))
1547 notify = in_rtchange, ip = 0;
1548 else if (cmd == PRC_MSGSIZE && ip && ip->ip_v == 4) {
1549 /*
1550 * Check to see if we have a valid TCP connection
1551 * corresponding to the address in the ICMP message
1552 * payload.
1553 *
1554 * Boundary check is made in icmp_input(), with ICMP_ADVLENMIN.
1555 */
1556 th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2));
1557 #ifdef INET6
1558 memset(&src6, 0, sizeof(src6));
1559 memset(&dst6, 0, sizeof(dst6));
1560 src6.s6_addr16[5] = dst6.s6_addr16[5] = 0xffff;
1561 memcpy(&src6.s6_addr32[3], &ip->ip_src, sizeof(struct in_addr));
1562 memcpy(&dst6.s6_addr32[3], &ip->ip_dst, sizeof(struct in_addr));
1563 #endif
1564 if ((inp = in_pcblookup_connect(&tcbtable, ip->ip_dst,
1565 th->th_dport, ip->ip_src, th->th_sport)) != NULL)
1566 #ifdef INET6
1567 in6p = NULL;
1568 #else
1569 ;
1570 #endif
1571 #ifdef INET6
1572 else if ((in6p = in6_pcblookup_connect(&tcbtable, &dst6,
1573 th->th_dport, &src6, th->th_sport, 0)) != NULL)
1574 ;
1575 #endif
1576 else
1577 return NULL;
1578
1579 /*
1580 * Now that we've validated that we are actually communicating
1581 * with the host indicated in the ICMP message, locate the
1582 * ICMP header, recalculate the new MTU, and create the
1583 * corresponding routing entry.
1584 */
1585 icp = (struct icmp *)((char *)ip -
1586 offsetof(struct icmp, icmp_ip));
1587 if (inp) {
1588 if ((tp = intotcpcb(inp)) == NULL)
1589 return NULL;
1590 }
1591 #ifdef INET6
1592 else if (in6p) {
1593 if ((tp = in6totcpcb(in6p)) == NULL)
1594 return NULL;
1595 }
1596 #endif
1597 else
1598 return NULL;
1599 seq = ntohl(th->th_seq);
1600 if (SEQ_LT(seq, tp->snd_una) || SEQ_GT(seq, tp->snd_max))
1601 return NULL;
1602 /*
1603 * If the ICMP message advertises a Next-Hop MTU
1604 * equal or larger than the maximum packet size we have
1605 * ever sent, drop the message.
1606 */
1607 mtu = (u_int)ntohs(icp->icmp_nextmtu);
1608 if (mtu >= tp->t_pmtud_mtu_sent)
1609 return NULL;
1610 if (mtu >= tcp_hdrsz(tp) + tp->t_pmtud_mss_acked) {
1611 /*
1612 * Calculate new MTU, and create corresponding
1613 * route (traditional PMTUD).
1614 */
1615 tp->t_flags &= ~TF_PMTUD_PEND;
1616 icmp_mtudisc(icp, ip->ip_dst);
1617 } else {
1618 /*
1619 * Record the information got in the ICMP
1620 * message; act on it later.
1621 * If we had already recorded an ICMP message,
1622 * replace the old one only if the new message
1623 * refers to an older TCP segment
1624 */
1625 if (tp->t_flags & TF_PMTUD_PEND) {
1626 if (SEQ_LT(tp->t_pmtud_th_seq, seq))
1627 return NULL;
1628 } else
1629 tp->t_flags |= TF_PMTUD_PEND;
1630 tp->t_pmtud_th_seq = seq;
1631 tp->t_pmtud_nextmtu = icp->icmp_nextmtu;
1632 tp->t_pmtud_ip_len = icp->icmp_ip.ip_len;
1633 tp->t_pmtud_ip_hl = icp->icmp_ip.ip_hl;
1634 }
1635 return NULL;
1636 } else if (cmd == PRC_HOSTDEAD)
1637 ip = 0;
1638 else if (errno == 0)
1639 return NULL;
1640 if (ip && ip->ip_v == 4 && sa->sa_family == AF_INET) {
1641 th = (struct tcphdr *)((char *)ip + (ip->ip_hl << 2));
1642 nmatch = in_pcbnotify(&tcbtable, satocsin(sa)->sin_addr,
1643 th->th_dport, ip->ip_src, th->th_sport, errno, notify);
1644 if (nmatch == 0 && syn_cache_count &&
1645 (inetctlerrmap[cmd] == EHOSTUNREACH ||
1646 inetctlerrmap[cmd] == ENETUNREACH ||
1647 inetctlerrmap[cmd] == EHOSTDOWN)) {
1648 struct sockaddr_in sin;
1649 memset(&sin, 0, sizeof(sin));
1650 sin.sin_len = sizeof(sin);
1651 sin.sin_family = AF_INET;
1652 sin.sin_port = th->th_sport;
1653 sin.sin_addr = ip->ip_src;
1654 syn_cache_unreach((struct sockaddr *)&sin, sa, th);
1655 }
1656
1657 /* XXX mapped address case */
1658 } else
1659 in_pcbnotifyall(&tcbtable, satocsin(sa)->sin_addr, errno,
1660 notify);
1661 return NULL;
1662 }
1663
1664 /*
1665 * When a source quench is received, we are being notified of congestion.
1666 * Close the congestion window down to the Loss Window (one segment).
1667 * We will gradually open it again as we proceed.
1668 */
1669 void
1670 tcp_quench(struct inpcb *inp, int errno)
1671 {
1672 struct tcpcb *tp = intotcpcb(inp);
1673
1674 if (tp) {
1675 tp->snd_cwnd = tp->t_segsz;
1676 tp->t_bytes_acked = 0;
1677 }
1678 }
1679 #endif
1680
1681 #ifdef INET6
1682 void
1683 tcp6_quench(struct in6pcb *in6p, int errno)
1684 {
1685 struct tcpcb *tp = in6totcpcb(in6p);
1686
1687 if (tp) {
1688 tp->snd_cwnd = tp->t_segsz;
1689 tp->t_bytes_acked = 0;
1690 }
1691 }
1692 #endif
1693
1694 #ifdef INET
1695 /*
1696 * Path MTU Discovery handlers.
1697 */
1698 void
1699 tcp_mtudisc_callback(struct in_addr faddr)
1700 {
1701 #ifdef INET6
1702 struct in6_addr in6;
1703 #endif
1704
1705 in_pcbnotifyall(&tcbtable, faddr, EMSGSIZE, tcp_mtudisc);
1706 #ifdef INET6
1707 memset(&in6, 0, sizeof(in6));
1708 in6.s6_addr16[5] = 0xffff;
1709 memcpy(&in6.s6_addr32[3], &faddr, sizeof(struct in_addr));
1710 tcp6_mtudisc_callback(&in6);
1711 #endif
1712 }
1713
1714 /*
1715 * On receipt of path MTU corrections, flush old route and replace it
1716 * with the new one. Retransmit all unacknowledged packets, to ensure
1717 * that all packets will be received.
1718 */
1719 void
1720 tcp_mtudisc(struct inpcb *inp, int errno)
1721 {
1722 struct tcpcb *tp = intotcpcb(inp);
1723 struct rtentry *rt = in_pcbrtentry(inp);
1724
1725 if (tp != 0) {
1726 if (rt != 0) {
1727 /*
1728 * If this was not a host route, remove and realloc.
1729 */
1730 if ((rt->rt_flags & RTF_HOST) == 0) {
1731 in_rtchange(inp, errno);
1732 if ((rt = in_pcbrtentry(inp)) == 0)
1733 return;
1734 }
1735
1736 /*
1737 * Slow start out of the error condition. We
1738 * use the MTU because we know it's smaller
1739 * than the previously transmitted segment.
1740 *
1741 * Note: This is more conservative than the
1742 * suggestion in draft-floyd-incr-init-win-03.
1743 */
1744 if (rt->rt_rmx.rmx_mtu != 0)
1745 tp->snd_cwnd =
1746 TCP_INITIAL_WINDOW(tcp_init_win,
1747 rt->rt_rmx.rmx_mtu);
1748 }
1749
1750 /*
1751 * Resend unacknowledged packets.
1752 */
1753 tp->snd_nxt = tp->sack_newdata = tp->snd_una;
1754 tcp_output(tp);
1755 }
1756 }
1757 #endif
1758
1759 #ifdef INET6
1760 /*
1761 * Path MTU Discovery handlers.
1762 */
1763 void
1764 tcp6_mtudisc_callback(struct in6_addr *faddr)
1765 {
1766 struct sockaddr_in6 sin6;
1767
1768 memset(&sin6, 0, sizeof(sin6));
1769 sin6.sin6_family = AF_INET6;
1770 sin6.sin6_len = sizeof(struct sockaddr_in6);
1771 sin6.sin6_addr = *faddr;
1772 (void) in6_pcbnotify(&tcbtable, (struct sockaddr *)&sin6, 0,
1773 (const struct sockaddr *)&sa6_any, 0, PRC_MSGSIZE, NULL, tcp6_mtudisc);
1774 }
1775
1776 void
1777 tcp6_mtudisc(struct in6pcb *in6p, int errno)
1778 {
1779 struct tcpcb *tp = in6totcpcb(in6p);
1780 struct rtentry *rt = in6_pcbrtentry(in6p);
1781
1782 if (tp != 0) {
1783 if (rt != 0) {
1784 /*
1785 * If this was not a host route, remove and realloc.
1786 */
1787 if ((rt->rt_flags & RTF_HOST) == 0) {
1788 in6_rtchange(in6p, errno);
1789 if ((rt = in6_pcbrtentry(in6p)) == 0)
1790 return;
1791 }
1792
1793 /*
1794 * Slow start out of the error condition. We
1795 * use the MTU because we know it's smaller
1796 * than the previously transmitted segment.
1797 *
1798 * Note: This is more conservative than the
1799 * suggestion in draft-floyd-incr-init-win-03.
1800 */
1801 if (rt->rt_rmx.rmx_mtu != 0)
1802 tp->snd_cwnd =
1803 TCP_INITIAL_WINDOW(tcp_init_win,
1804 rt->rt_rmx.rmx_mtu);
1805 }
1806
1807 /*
1808 * Resend unacknowledged packets.
1809 */
1810 tp->snd_nxt = tp->sack_newdata = tp->snd_una;
1811 tcp_output(tp);
1812 }
1813 }
1814 #endif /* INET6 */
1815
1816 /*
1817 * Compute the MSS to advertise to the peer. Called only during
1818 * the 3-way handshake. If we are the server (peer initiated
1819 * connection), we are called with a pointer to the interface
1820 * on which the SYN packet arrived. If we are the client (we
1821 * initiated connection), we are called with a pointer to the
1822 * interface out which this connection should go.
1823 *
1824 * NOTE: Do not subtract IP option/extension header size nor IPsec
1825 * header size from MSS advertisement. MSS option must hold the maximum
1826 * segment size we can accept, so it must always be:
1827 * max(if mtu) - ip header - tcp header
1828 */
1829 u_long
1830 tcp_mss_to_advertise(const struct ifnet *ifp, int af)
1831 {
1832 extern u_long in_maxmtu;
1833 u_long mss = 0;
1834 u_long hdrsiz;
1835
1836 /*
1837 * In order to avoid defeating path MTU discovery on the peer,
1838 * we advertise the max MTU of all attached networks as our MSS,
1839 * per RFC 1191, section 3.1.
1840 *
1841 * We provide the option to advertise just the MTU of
1842 * the interface on which we hope this connection will
1843 * be receiving. If we are responding to a SYN, we
1844 * will have a pretty good idea about this, but when
1845 * initiating a connection there is a bit more doubt.
1846 *
1847 * We also need to ensure that loopback has a large enough
1848 * MSS, as the loopback MTU is never included in in_maxmtu.
1849 */
1850
1851 if (ifp != NULL)
1852 switch (af) {
1853 case AF_INET:
1854 mss = ifp->if_mtu;
1855 break;
1856 #ifdef INET6
1857 case AF_INET6:
1858 mss = IN6_LINKMTU(ifp);
1859 break;
1860 #endif
1861 }
1862
1863 if (tcp_mss_ifmtu == 0)
1864 switch (af) {
1865 case AF_INET:
1866 mss = max(in_maxmtu, mss);
1867 break;
1868 #ifdef INET6
1869 case AF_INET6:
1870 mss = max(in6_maxmtu, mss);
1871 break;
1872 #endif
1873 }
1874
1875 switch (af) {
1876 case AF_INET:
1877 hdrsiz = sizeof(struct ip);
1878 break;
1879 #ifdef INET6
1880 case AF_INET6:
1881 hdrsiz = sizeof(struct ip6_hdr);
1882 break;
1883 #endif
1884 default:
1885 hdrsiz = 0;
1886 break;
1887 }
1888 hdrsiz += sizeof(struct tcphdr);
1889 if (mss > hdrsiz)
1890 mss -= hdrsiz;
1891
1892 mss = max(tcp_mssdflt, mss);
1893 return (mss);
1894 }
1895
1896 /*
1897 * Set connection variables based on the peer's advertised MSS.
1898 * We are passed the TCPCB for the actual connection. If we
1899 * are the server, we are called by the compressed state engine
1900 * when the 3-way handshake is complete. If we are the client,
1901 * we are called when we receive the SYN,ACK from the server.
1902 *
1903 * NOTE: Our advertised MSS value must be initialized in the TCPCB
1904 * before this routine is called!
1905 */
1906 void
1907 tcp_mss_from_peer(struct tcpcb *tp, int offer)
1908 {
1909 struct socket *so;
1910 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH)
1911 struct rtentry *rt;
1912 #endif
1913 u_long bufsize;
1914 int mss;
1915
1916 #ifdef DIAGNOSTIC
1917 if (tp->t_inpcb && tp->t_in6pcb)
1918 panic("tcp_mss_from_peer: both t_inpcb and t_in6pcb are set");
1919 #endif
1920 so = NULL;
1921 rt = NULL;
1922 #ifdef INET
1923 if (tp->t_inpcb) {
1924 so = tp->t_inpcb->inp_socket;
1925 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH)
1926 rt = in_pcbrtentry(tp->t_inpcb);
1927 #endif
1928 }
1929 #endif
1930 #ifdef INET6
1931 if (tp->t_in6pcb) {
1932 so = tp->t_in6pcb->in6p_socket;
1933 #if defined(RTV_SPIPE) || defined(RTV_SSTHRESH)
1934 rt = in6_pcbrtentry(tp->t_in6pcb);
1935 #endif
1936 }
1937 #endif
1938
1939 /*
1940 * As per RFC1122, use the default MSS value, unless they
1941 * sent us an offer. Do not accept offers less than 256 bytes.
1942 */
1943 mss = tcp_mssdflt;
1944 if (offer)
1945 mss = offer;
1946 mss = max(mss, 256); /* sanity */
1947 tp->t_peermss = mss;
1948 mss -= tcp_optlen(tp);
1949 #ifdef INET
1950 if (tp->t_inpcb)
1951 mss -= ip_optlen(tp->t_inpcb);
1952 #endif
1953 #ifdef INET6
1954 if (tp->t_in6pcb)
1955 mss -= ip6_optlen(tp->t_in6pcb);
1956 #endif
1957
1958 /*
1959 * If there's a pipesize, change the socket buffer to that size.
1960 * Make the socket buffer an integral number of MSS units. If
1961 * the MSS is larger than the socket buffer, artificially decrease
1962 * the MSS.
1963 */
1964 #ifdef RTV_SPIPE
1965 if (rt != NULL && rt->rt_rmx.rmx_sendpipe != 0)
1966 bufsize = rt->rt_rmx.rmx_sendpipe;
1967 else
1968 #endif
1969 {
1970 KASSERT(so != NULL);
1971 bufsize = so->so_snd.sb_hiwat;
1972 }
1973 if (bufsize < mss)
1974 mss = bufsize;
1975 else {
1976 bufsize = roundup(bufsize, mss);
1977 if (bufsize > sb_max)
1978 bufsize = sb_max;
1979 (void) sbreserve(&so->so_snd, bufsize, so);
1980 }
1981 tp->t_segsz = mss;
1982
1983 #ifdef RTV_SSTHRESH
1984 if (rt != NULL && rt->rt_rmx.rmx_ssthresh) {
1985 /*
1986 * There's some sort of gateway or interface buffer
1987 * limit on the path. Use this to set the slow
1988 * start threshold, but set the threshold to no less
1989 * than 2 * MSS.
1990 */
1991 tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh);
1992 }
1993 #endif
1994 }
1995
1996 /*
1997 * Processing necessary when a TCP connection is established.
1998 */
1999 void
2000 tcp_established(struct tcpcb *tp)
2001 {
2002 struct socket *so;
2003 #ifdef RTV_RPIPE
2004 struct rtentry *rt;
2005 #endif
2006 u_long bufsize;
2007
2008 #ifdef DIAGNOSTIC
2009 if (tp->t_inpcb && tp->t_in6pcb)
2010 panic("tcp_established: both t_inpcb and t_in6pcb are set");
2011 #endif
2012 so = NULL;
2013 rt = NULL;
2014 #ifdef INET
2015 if (tp->t_inpcb) {
2016 so = tp->t_inpcb->inp_socket;
2017 #if defined(RTV_RPIPE)
2018 rt = in_pcbrtentry(tp->t_inpcb);
2019 #endif
2020 }
2021 #endif
2022 #ifdef INET6
2023 if (tp->t_in6pcb) {
2024 so = tp->t_in6pcb->in6p_socket;
2025 #if defined(RTV_RPIPE)
2026 rt = in6_pcbrtentry(tp->t_in6pcb);
2027 #endif
2028 }
2029 #endif
2030
2031 tp->t_state = TCPS_ESTABLISHED;
2032 TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepidle);
2033
2034 #ifdef RTV_RPIPE
2035 if (rt != NULL && rt->rt_rmx.rmx_recvpipe != 0)
2036 bufsize = rt->rt_rmx.rmx_recvpipe;
2037 else
2038 #endif
2039 {
2040 KASSERT(so != NULL);
2041 bufsize = so->so_rcv.sb_hiwat;
2042 }
2043 if (bufsize > tp->t_ourmss) {
2044 bufsize = roundup(bufsize, tp->t_ourmss);
2045 if (bufsize > sb_max)
2046 bufsize = sb_max;
2047 (void) sbreserve(&so->so_rcv, bufsize, so);
2048 }
2049 }
2050
2051 /*
2052 * Check if there's an initial rtt or rttvar. Convert from the
2053 * route-table units to scaled multiples of the slow timeout timer.
2054 * Called only during the 3-way handshake.
2055 */
2056 void
2057 tcp_rmx_rtt(struct tcpcb *tp)
2058 {
2059 #ifdef RTV_RTT
2060 struct rtentry *rt = NULL;
2061 int rtt;
2062
2063 #ifdef DIAGNOSTIC
2064 if (tp->t_inpcb && tp->t_in6pcb)
2065 panic("tcp_rmx_rtt: both t_inpcb and t_in6pcb are set");
2066 #endif
2067 #ifdef INET
2068 if (tp->t_inpcb)
2069 rt = in_pcbrtentry(tp->t_inpcb);
2070 #endif
2071 #ifdef INET6
2072 if (tp->t_in6pcb)
2073 rt = in6_pcbrtentry(tp->t_in6pcb);
2074 #endif
2075 if (rt == NULL)
2076 return;
2077
2078 if (tp->t_srtt == 0 && (rtt = rt->rt_rmx.rmx_rtt)) {
2079 /*
2080 * XXX The lock bit for MTU indicates that the value
2081 * is also a minimum value; this is subject to time.
2082 */
2083 if (rt->rt_rmx.rmx_locks & RTV_RTT)
2084 TCPT_RANGESET(tp->t_rttmin,
2085 rtt / (RTM_RTTUNIT / PR_SLOWHZ),
2086 TCPTV_MIN, TCPTV_REXMTMAX);
2087 tp->t_srtt = rtt /
2088 ((RTM_RTTUNIT / PR_SLOWHZ) >> (TCP_RTT_SHIFT + 2));
2089 if (rt->rt_rmx.rmx_rttvar) {
2090 tp->t_rttvar = rt->rt_rmx.rmx_rttvar /
2091 ((RTM_RTTUNIT / PR_SLOWHZ) >>
2092 (TCP_RTTVAR_SHIFT + 2));
2093 } else {
2094 /* Default variation is +- 1 rtt */
2095 tp->t_rttvar =
2096 tp->t_srtt >> (TCP_RTT_SHIFT - TCP_RTTVAR_SHIFT);
2097 }
2098 TCPT_RANGESET(tp->t_rxtcur,
2099 ((tp->t_srtt >> 2) + tp->t_rttvar) >> (1 + 2),
2100 tp->t_rttmin, TCPTV_REXMTMAX);
2101 }
2102 #endif
2103 }
2104
2105 tcp_seq tcp_iss_seq = 0; /* tcp initial seq # */
2106 #if NRND > 0
2107 u_int8_t tcp_iss_secret[16]; /* 128 bits; should be plenty */
2108 #endif
2109
2110 /*
2111 * Get a new sequence value given a tcp control block
2112 */
2113 tcp_seq
2114 tcp_new_iss(struct tcpcb *tp, tcp_seq addin)
2115 {
2116
2117 #ifdef INET
2118 if (tp->t_inpcb != NULL) {
2119 return (tcp_new_iss1(&tp->t_inpcb->inp_laddr,
2120 &tp->t_inpcb->inp_faddr, tp->t_inpcb->inp_lport,
2121 tp->t_inpcb->inp_fport, sizeof(tp->t_inpcb->inp_laddr),
2122 addin));
2123 }
2124 #endif
2125 #ifdef INET6
2126 if (tp->t_in6pcb != NULL) {
2127 return (tcp_new_iss1(&tp->t_in6pcb->in6p_laddr,
2128 &tp->t_in6pcb->in6p_faddr, tp->t_in6pcb->in6p_lport,
2129 tp->t_in6pcb->in6p_fport, sizeof(tp->t_in6pcb->in6p_laddr),
2130 addin));
2131 }
2132 #endif
2133 /* Not possible. */
2134 panic("tcp_new_iss");
2135 }
2136
2137 /*
2138 * This routine actually generates a new TCP initial sequence number.
2139 */
2140 tcp_seq
2141 tcp_new_iss1(void *laddr, void *faddr, u_int16_t lport, u_int16_t fport,
2142 size_t addrsz, tcp_seq addin)
2143 {
2144 tcp_seq tcp_iss;
2145
2146 #if NRND > 0
2147 static bool tcp_iss_gotten_secret;
2148
2149 /*
2150 * If we haven't been here before, initialize our cryptographic
2151 * hash secret.
2152 */
2153 if (tcp_iss_gotten_secret == false) {
2154 rnd_extract_data(tcp_iss_secret, sizeof(tcp_iss_secret),
2155 RND_EXTRACT_ANY);
2156 tcp_iss_gotten_secret = true;
2157 }
2158
2159 if (tcp_do_rfc1948) {
2160 MD5_CTX ctx;
2161 u_int8_t hash[16]; /* XXX MD5 knowledge */
2162
2163 /*
2164 * Compute the base value of the ISS. It is a hash
2165 * of (saddr, sport, daddr, dport, secret).
2166 */
2167 MD5Init(&ctx);
2168
2169 MD5Update(&ctx, (u_char *) laddr, addrsz);
2170 MD5Update(&ctx, (u_char *) &lport, sizeof(lport));
2171
2172 MD5Update(&ctx, (u_char *) faddr, addrsz);
2173 MD5Update(&ctx, (u_char *) &fport, sizeof(fport));
2174
2175 MD5Update(&ctx, tcp_iss_secret, sizeof(tcp_iss_secret));
2176
2177 MD5Final(hash, &ctx);
2178
2179 memcpy(&tcp_iss, hash, sizeof(tcp_iss));
2180
2181 /*
2182 * Now increment our "timer", and add it in to
2183 * the computed value.
2184 *
2185 * XXX Use `addin'?
2186 * XXX TCP_ISSINCR too large to use?
2187 */
2188 tcp_iss_seq += TCP_ISSINCR;
2189 #ifdef TCPISS_DEBUG
2190 printf("ISS hash 0x%08x, ", tcp_iss);
2191 #endif
2192 tcp_iss += tcp_iss_seq + addin;
2193 #ifdef TCPISS_DEBUG
2194 printf("new ISS 0x%08x\n", tcp_iss);
2195 #endif
2196 } else
2197 #endif /* NRND > 0 */
2198 {
2199 /*
2200 * Randomize.
2201 */
2202 #if NRND > 0
2203 rnd_extract_data(&tcp_iss, sizeof(tcp_iss), RND_EXTRACT_ANY);
2204 #else
2205 tcp_iss = arc4random();
2206 #endif
2207
2208 /*
2209 * If we were asked to add some amount to a known value,
2210 * we will take a random value obtained above, mask off
2211 * the upper bits, and add in the known value. We also
2212 * add in a constant to ensure that we are at least a
2213 * certain distance from the original value.
2214 *
2215 * This is used when an old connection is in timed wait
2216 * and we have a new one coming in, for instance.
2217 */
2218 if (addin != 0) {
2219 #ifdef TCPISS_DEBUG
2220 printf("Random %08x, ", tcp_iss);
2221 #endif
2222 tcp_iss &= TCP_ISS_RANDOM_MASK;
2223 tcp_iss += addin + TCP_ISSINCR;
2224 #ifdef TCPISS_DEBUG
2225 printf("Old ISS %08x, ISS %08x\n", addin, tcp_iss);
2226 #endif
2227 } else {
2228 tcp_iss &= TCP_ISS_RANDOM_MASK;
2229 tcp_iss += tcp_iss_seq;
2230 tcp_iss_seq += TCP_ISSINCR;
2231 #ifdef TCPISS_DEBUG
2232 printf("ISS %08x\n", tcp_iss);
2233 #endif
2234 }
2235 }
2236
2237 if (tcp_compat_42) {
2238 /*
2239 * Limit it to the positive range for really old TCP
2240 * implementations.
2241 * Just AND off the top bit instead of checking if
2242 * is set first - saves a branch 50% of the time.
2243 */
2244 tcp_iss &= 0x7fffffff; /* XXX */
2245 }
2246
2247 return (tcp_iss);
2248 }
2249
2250 #if defined(IPSEC) || defined(FAST_IPSEC)
2251 /* compute ESP/AH header size for TCP, including outer IP header. */
2252 size_t
2253 ipsec4_hdrsiz_tcp(struct tcpcb *tp)
2254 {
2255 struct inpcb *inp;
2256 size_t hdrsiz;
2257
2258 /* XXX mapped addr case (tp->t_in6pcb) */
2259 if (!tp || !tp->t_template || !(inp = tp->t_inpcb))
2260 return 0;
2261 switch (tp->t_family) {
2262 case AF_INET:
2263 /* XXX: should use currect direction. */
2264 hdrsiz = ipsec4_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, inp);
2265 break;
2266 default:
2267 hdrsiz = 0;
2268 break;
2269 }
2270
2271 return hdrsiz;
2272 }
2273
2274 #ifdef INET6
2275 size_t
2276 ipsec6_hdrsiz_tcp(struct tcpcb *tp)
2277 {
2278 struct in6pcb *in6p;
2279 size_t hdrsiz;
2280
2281 if (!tp || !tp->t_template || !(in6p = tp->t_in6pcb))
2282 return 0;
2283 switch (tp->t_family) {
2284 case AF_INET6:
2285 /* XXX: should use currect direction. */
2286 hdrsiz = ipsec6_hdrsiz(tp->t_template, IPSEC_DIR_OUTBOUND, in6p);
2287 break;
2288 case AF_INET:
2289 /* mapped address case - tricky */
2290 default:
2291 hdrsiz = 0;
2292 break;
2293 }
2294
2295 return hdrsiz;
2296 }
2297 #endif
2298 #endif /*IPSEC*/
2299
2300 /*
2301 * Determine the length of the TCP options for this connection.
2302 *
2303 * XXX: What do we do for SACK, when we add that? Just reserve
2304 * all of the space? Otherwise we can't exactly be incrementing
2305 * cwnd by an amount that varies depending on the amount we last
2306 * had to SACK!
2307 */
2308
2309 u_int
2310 tcp_optlen(struct tcpcb *tp)
2311 {
2312 u_int optlen;
2313
2314 optlen = 0;
2315 if ((tp->t_flags & (TF_REQ_TSTMP|TF_RCVD_TSTMP|TF_NOOPT)) ==
2316 (TF_REQ_TSTMP | TF_RCVD_TSTMP))
2317 optlen += TCPOLEN_TSTAMP_APPA;
2318
2319 #ifdef TCP_SIGNATURE
2320 if (tp->t_flags & TF_SIGNATURE)
2321 optlen += TCPOLEN_SIGNATURE + 2;
2322 #endif /* TCP_SIGNATURE */
2323
2324 return optlen;
2325 }
2326
2327 u_int
2328 tcp_hdrsz(struct tcpcb *tp)
2329 {
2330 u_int hlen;
2331
2332 switch (tp->t_family) {
2333 #ifdef INET6
2334 case AF_INET6:
2335 hlen = sizeof(struct ip6_hdr);
2336 break;
2337 #endif
2338 case AF_INET:
2339 hlen = sizeof(struct ip);
2340 break;
2341 default:
2342 hlen = 0;
2343 break;
2344 }
2345 hlen += sizeof(struct tcphdr);
2346
2347 if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP &&
2348 (tp->t_flags & TF_RCVD_TSTMP) == TF_RCVD_TSTMP)
2349 hlen += TCPOLEN_TSTAMP_APPA;
2350 #ifdef TCP_SIGNATURE
2351 if (tp->t_flags & TF_SIGNATURE)
2352 hlen += TCPOLEN_SIGLEN;
2353 #endif
2354 return hlen;
2355 }
2356
2357 void
2358 tcp_statinc(u_int stat)
2359 {
2360
2361 KASSERT(stat < TCP_NSTATS);
2362 TCP_STATINC(stat);
2363 }
2364
2365 void
2366 tcp_statadd(u_int stat, uint64_t val)
2367 {
2368
2369 KASSERT(stat < TCP_NSTATS);
2370 TCP_STATADD(stat, val);
2371 }
NetBSD on the FriendlyARM MINI2440