1/* $NetBSD: ip_icmp.c,v 1.153 2016/10/25 02:45:09 ozaki-r 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) 1998, 2000 The NetBSD Foundation, Inc.
34 * All rights reserved.
35 *
36 * This code is derived from software contributed to The NetBSD Foundation
37 * by Public Access Networks Corporation ("Panix"). It was developed under
38 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
39 *
40 * This code is derived from software contributed to The NetBSD Foundation
41 * by Jason R. Thorpe of Zembu Labs, Inc.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 *
52 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
53 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
54 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
55 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
56 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
57 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
58 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
59 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
60 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
61 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
62 * POSSIBILITY OF SUCH DAMAGE.
63 */
64
65/*
66 * Copyright (c) 1982, 1986, 1988, 1993
67 * The Regents of the University of California. All rights reserved.
68 *
69 * Redistribution and use in source and binary forms, with or without
70 * modification, are permitted provided that the following conditions
71 * are met:
72 * 1. Redistributions of source code must retain the above copyright
73 * notice, this list of conditions and the following disclaimer.
74 * 2. Redistributions in binary form must reproduce the above copyright
75 * notice, this list of conditions and the following disclaimer in the
76 * documentation and/or other materials provided with the distribution.
77 * 3. Neither the name of the University nor the names of its contributors
78 * may be used to endorse or promote products derived from this software
79 * without specific prior written permission.
80 *
81 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
82 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
83 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
84 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
85 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
86 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
87 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
88 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
89 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
90 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
91 * SUCH DAMAGE.
92 *
93 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
94 */
95
96#include <sys/cdefs.h>
97__KERNEL_RCSID(0, "$NetBSD: ip_icmp.c,v 1.153 2016/10/25 02:45:09 ozaki-r Exp $");
98
99#ifdef _KERNEL_OPT
100#include "opt_ipsec.h"
101#endif
102
103#include <sys/param.h>
104#include <sys/systm.h>
105#include <sys/mbuf.h>
106#include <sys/protosw.h>
107#include <sys/socket.h>
108#include <sys/kmem.h>
109#include <sys/time.h>
110#include <sys/kernel.h>
111#include <sys/syslog.h>
112#include <sys/sysctl.h>
113
114#include <net/if.h>
115#include <net/route.h>
116
117#include <netinet/in.h>
118#include <netinet/in_systm.h>
119#include <netinet/in_var.h>
120#include <netinet/ip.h>
121#include <netinet/ip_icmp.h>
122#include <netinet/ip_var.h>
123#include <netinet/in_pcb.h>
124#include <netinet/in_proto.h>
125#include <netinet/icmp_var.h>
126#include <netinet/icmp_private.h>
127
128#ifdef IPSEC
129#include <netipsec/ipsec.h>
130#include <netipsec/key.h>
131#endif /* IPSEC*/
132
133/*
134 * ICMP routines: error generation, receive packet processing, and
135 * routines to turnaround packets back to the originator, and
136 * host table maintenance routines.
137 */
138
139int icmpmaskrepl = 0;
140int icmpbmcastecho = 0;
141#ifdef ICMPPRINTFS
142int icmpprintfs = 0;
143#endif
144int icmpreturndatabytes = 8;
145
146percpu_t *icmpstat_percpu;
147
148/*
149 * List of callbacks to notify when Path MTU changes are made.
150 */
151struct icmp_mtudisc_callback {
152 LIST_ENTRY(icmp_mtudisc_callback) mc_list;
153 void (*mc_func)(struct in_addr);
154};
155
156LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks =
157 LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks);
158
159#if 0
160static u_int ip_next_mtu(u_int, int);
161#else
162/*static*/ u_int ip_next_mtu(u_int, int);
163#endif
164
165extern int icmperrppslim;
166static int icmperrpps_count = 0;
167static struct timeval icmperrppslim_last;
168static int icmp_rediraccept = 1;
169static int icmp_redirtimeout = 600;
170static struct rttimer_queue *icmp_redirect_timeout_q = NULL;
171
172static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *);
173static void icmp_redirect_timeout(struct rtentry *, struct rttimer *);
174
175static void sysctl_netinet_icmp_setup(struct sysctllog **);
176
177void
178icmp_init(void)
179{
180
181 sysctl_netinet_icmp_setup(NULL);
182
183 /*
184 * This is only useful if the user initializes redirtimeout to
185 * something other than zero.
186 */
187 if (icmp_redirtimeout != 0) {
188 icmp_redirect_timeout_q =
189 rt_timer_queue_create(icmp_redirtimeout);
190 }
191
192 icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS);
193}
194
195/*
196 * Register a Path MTU Discovery callback.
197 */
198void
199icmp_mtudisc_callback_register(void (*func)(struct in_addr))
200{
201 struct icmp_mtudisc_callback *mc;
202
203 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL;
204 mc = LIST_NEXT(mc, mc_list)) {
205 if (mc->mc_func == func)
206 return;
207 }
208
209 mc = kmem_alloc(sizeof(*mc), KM_SLEEP);
210 mc->mc_func = func;
211 LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, mc, mc_list);
212}
213
214/*
215 * Generate an error packet of type error
216 * in response to bad packet ip.
217 */
218void
219icmp_error(struct mbuf *n, int type, int code, n_long dest,
220 int destmtu)
221{
222 struct ip *oip = mtod(n, struct ip *), *nip;
223 unsigned oiplen = oip->ip_hl << 2;
224 struct icmp *icp;
225 struct mbuf *m;
226 struct m_tag *mtag;
227 unsigned icmplen, mblen;
228
229#ifdef ICMPPRINTFS
230 if (icmpprintfs)
231 printf("icmp_error(%p, type:%d, code:%d)\n", oip, type, code);
232#endif
233 if (type != ICMP_REDIRECT)
234 ICMP_STATINC(ICMP_STAT_ERROR);
235 /*
236 * Don't send error if the original packet was encrypted.
237 * Don't send error if not the first fragment of message.
238 * Don't error if the old packet protocol was ICMP
239 * error message, only known informational types.
240 */
241 if (n->m_flags & M_DECRYPTED)
242 goto freeit;
243 if (oip->ip_off &~ htons(IP_MF|IP_DF))
244 goto freeit;
245 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
246 n->m_len >= oiplen + ICMP_MINLEN &&
247 !ICMP_INFOTYPE(((struct icmp *)((char *)oip + oiplen))->icmp_type)) {
248 ICMP_STATINC(ICMP_STAT_OLDICMP);
249 goto freeit;
250 }
251 /* Don't send error in response to a multicast or broadcast packet */
252 if (n->m_flags & (M_BCAST|M_MCAST))
253 goto freeit;
254
255 /*
256 * First, do a rate limitation check.
257 */
258 if (icmp_ratelimit(&oip->ip_src, type, code)) {
259 /* XXX stat */
260 goto freeit;
261 }
262
263 /*
264 * Now, formulate icmp message
265 */
266 icmplen = oiplen + min(icmpreturndatabytes,
267 ntohs(oip->ip_len) - oiplen);
268 /*
269 * Defend against mbuf chains shorter than oip->ip_len - oiplen:
270 */
271 mblen = 0;
272 for (m = n; m && (mblen < icmplen); m = m->m_next)
273 mblen += m->m_len;
274 icmplen = min(mblen, icmplen);
275
276 /*
277 * As we are not required to return everything we have,
278 * we return whatever we can return at ease.
279 *
280 * Note that ICMP datagrams longer than 576 octets are out of spec
281 * according to RFC1812; the limit on icmpreturndatabytes below in
282 * icmp_sysctl will keep things below that limit.
283 */
284
285 KASSERT(ICMP_MINLEN <= MCLBYTES);
286
287 if (icmplen + ICMP_MINLEN > MCLBYTES)
288 icmplen = MCLBYTES - ICMP_MINLEN;
289
290 m = m_gethdr(M_DONTWAIT, MT_HEADER);
291 if (m && (icmplen + ICMP_MINLEN > MHLEN)) {
292 MCLGET(m, M_DONTWAIT);
293 if ((m->m_flags & M_EXT) == 0) {
294 m_freem(m);
295 m = NULL;
296 }
297 }
298 if (m == NULL)
299 goto freeit;
300 MCLAIM(m, n->m_owner);
301 m->m_len = icmplen + ICMP_MINLEN;
302 if ((m->m_flags & M_EXT) == 0)
303 MH_ALIGN(m, m->m_len);
304 else {
305 m->m_data += sizeof(struct ip);
306 m->m_len -= sizeof(struct ip);
307 }
308 icp = mtod(m, struct icmp *);
309 if ((u_int)type > ICMP_MAXTYPE)
310 panic("icmp_error");
311 ICMP_STATINC(ICMP_STAT_OUTHIST + type);
312 icp->icmp_type = type;
313 if (type == ICMP_REDIRECT)
314 icp->icmp_gwaddr.s_addr = dest;
315 else {
316 icp->icmp_void = 0;
317 /*
318 * The following assignments assume an overlay with the
319 * zeroed icmp_void field.
320 */
321 if (type == ICMP_PARAMPROB) {
322 icp->icmp_pptr = code;
323 code = 0;
324 } else if (type == ICMP_UNREACH &&
325 code == ICMP_UNREACH_NEEDFRAG && destmtu)
326 icp->icmp_nextmtu = htons(destmtu);
327 }
328
329 icp->icmp_code = code;
330 m_copydata(n, 0, icmplen, (void *)&icp->icmp_ip);
331
332 /*
333 * Now, copy old ip header (without options)
334 * in front of icmp message.
335 */
336 if ((m->m_flags & M_EXT) == 0 &&
337 m->m_data - sizeof(struct ip) < m->m_pktdat)
338 panic("icmp len");
339 m->m_data -= sizeof(struct ip);
340 m->m_len += sizeof(struct ip);
341 m->m_pkthdr.len = m->m_len;
342 m_copy_rcvif(m, n);
343 nip = mtod(m, struct ip *);
344 /* ip_v set in ip_output */
345 nip->ip_hl = sizeof(struct ip) >> 2;
346 nip->ip_tos = 0;
347 nip->ip_len = htons(m->m_len);
348 /* ip_id set in ip_output */
349 nip->ip_off = htons(0);
350 /* ip_ttl set in icmp_reflect */
351 nip->ip_p = IPPROTO_ICMP;
352 nip->ip_src = oip->ip_src;
353 nip->ip_dst = oip->ip_dst;
354 /* move PF m_tag to new packet, if it exists */
355 mtag = m_tag_find(n, PACKET_TAG_PF, NULL);
356 if (mtag != NULL) {
357 m_tag_unlink(n, mtag);
358 m_tag_prepend(m, mtag);
359 }
360 icmp_reflect(m);
361
362freeit:
363 m_freem(n);
364}
365
366struct sockaddr_in icmpsrc = {
367 .sin_len = sizeof (struct sockaddr_in),
368 .sin_family = AF_INET,
369};
370static struct sockaddr_in icmpdst = {
371 .sin_len = sizeof (struct sockaddr_in),
372 .sin_family = AF_INET,
373};
374static struct sockaddr_in icmpgw = {
375 .sin_len = sizeof (struct sockaddr_in),
376 .sin_family = AF_INET,
377};
378struct sockaddr_in icmpmask = {
379 .sin_len = 8,
380 .sin_family = 0,
381};
382
383/*
384 * Process a received ICMP message.
385 */
386void
387icmp_input(struct mbuf *m, ...)
388{
389 int proto;
390 struct icmp *icp;
391 struct ip *ip = mtod(m, struct ip *);
392 int icmplen;
393 int i;
394 struct in_ifaddr *ia;
395 void *(*ctlfunc)(int, const struct sockaddr *, void *);
396 int code;
397 int hlen;
398 va_list ap;
399 struct rtentry *rt;
400
401 va_start(ap, m);
402 hlen = va_arg(ap, int);
403 proto = va_arg(ap, int);
404 va_end(ap);
405
406 /*
407 * Locate icmp structure in mbuf, and check
408 * that not corrupted and of at least minimum length.
409 */
410 icmplen = ntohs(ip->ip_len) - hlen;
411#ifdef ICMPPRINTFS
412 if (icmpprintfs) {
413 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN];
414 printf("icmp_input from `%s' to `%s', len %d\n",
415 IN_PRINT(sbuf, &ip->ip_src), IN_PRINT(dbuf, &ip->ip_dst),
416 icmplen);
417 }
418#endif
419 if (icmplen < ICMP_MINLEN) {
420 ICMP_STATINC(ICMP_STAT_TOOSHORT);
421 goto freeit;
422 }
423 i = hlen + min(icmplen, ICMP_ADVLENMIN);
424 if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == NULL) {
425 ICMP_STATINC(ICMP_STAT_TOOSHORT);
426 return;
427 }
428 ip = mtod(m, struct ip *);
429 m->m_len -= hlen;
430 m->m_data += hlen;
431 icp = mtod(m, struct icmp *);
432 /* Don't need to assert alignment, here. */
433 if (in_cksum(m, icmplen)) {
434 ICMP_STATINC(ICMP_STAT_CHECKSUM);
435 goto freeit;
436 }
437 m->m_len += hlen;
438 m->m_data -= hlen;
439
440#ifdef ICMPPRINTFS
441 /*
442 * Message type specific processing.
443 */
444 if (icmpprintfs)
445 printf("icmp_input(type:%d, code:%d)\n", icp->icmp_type,
446 icp->icmp_code);
447#endif
448 if (icp->icmp_type > ICMP_MAXTYPE)
449 goto raw;
450 ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type);
451 code = icp->icmp_code;
452 switch (icp->icmp_type) {
453
454 case ICMP_UNREACH:
455 switch (code) {
456 case ICMP_UNREACH_PROTOCOL:
457 code = PRC_UNREACH_PROTOCOL;
458 break;
459
460 case ICMP_UNREACH_PORT:
461 code = PRC_UNREACH_PORT;
462 break;
463
464 case ICMP_UNREACH_SRCFAIL:
465 code = PRC_UNREACH_SRCFAIL;
466 break;
467
468 case ICMP_UNREACH_NEEDFRAG:
469 code = PRC_MSGSIZE;
470 break;
471
472 case ICMP_UNREACH_NET:
473 case ICMP_UNREACH_NET_UNKNOWN:
474 case ICMP_UNREACH_NET_PROHIB:
475 case ICMP_UNREACH_TOSNET:
476 code = PRC_UNREACH_NET;
477 break;
478
479 case ICMP_UNREACH_HOST:
480 case ICMP_UNREACH_HOST_UNKNOWN:
481 case ICMP_UNREACH_ISOLATED:
482 case ICMP_UNREACH_HOST_PROHIB:
483 case ICMP_UNREACH_TOSHOST:
484 case ICMP_UNREACH_ADMIN_PROHIBIT:
485 case ICMP_UNREACH_HOST_PREC:
486 case ICMP_UNREACH_PREC_CUTOFF:
487 code = PRC_UNREACH_HOST;
488 break;
489
490 default:
491 goto badcode;
492 }
493 goto deliver;
494
495 case ICMP_TIMXCEED:
496 if (code > 1)
497 goto badcode;
498 code += PRC_TIMXCEED_INTRANS;
499 goto deliver;
500
501 case ICMP_PARAMPROB:
502 if (code > 1)
503 goto badcode;
504 code = PRC_PARAMPROB;
505 goto deliver;
506
507 case ICMP_SOURCEQUENCH:
508 if (code)
509 goto badcode;
510 code = PRC_QUENCH;
511 goto deliver;
512
513 deliver:
514 /*
515 * Problem with datagram; advise higher level routines.
516 */
517 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
518 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
519 ICMP_STATINC(ICMP_STAT_BADLEN);
520 goto freeit;
521 }
522 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr))
523 goto badcode;
524#ifdef ICMPPRINTFS
525 if (icmpprintfs)
526 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
527#endif
528 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
529 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput;
530 if (ctlfunc)
531 (void) (*ctlfunc)(code, sintosa(&icmpsrc),
532 &icp->icmp_ip);
533 break;
534
535 badcode:
536 ICMP_STATINC(ICMP_STAT_BADCODE);
537 break;
538
539 case ICMP_ECHO:
540 if (!icmpbmcastecho &&
541 (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
542 ICMP_STATINC(ICMP_STAT_BMCASTECHO);
543 break;
544 }
545 icp->icmp_type = ICMP_ECHOREPLY;
546 goto reflect;
547
548 case ICMP_TSTAMP:
549 if (icmplen < ICMP_TSLEN) {
550 ICMP_STATINC(ICMP_STAT_BADLEN);
551 break;
552 }
553 if (!icmpbmcastecho &&
554 (m->m_flags & (M_MCAST | M_BCAST)) != 0) {
555 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP);
556 break;
557 }
558 icp->icmp_type = ICMP_TSTAMPREPLY;
559 icp->icmp_rtime = iptime();
560 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
561 goto reflect;
562
563 case ICMP_MASKREQ: {
564 struct ifnet *rcvif;
565 int s, ss;
566 struct ifaddr *ifa;
567
568 if (icmpmaskrepl == 0)
569 break;
570 /*
571 * We are not able to respond with all ones broadcast
572 * unless we receive it over a point-to-point interface.
573 */
574 if (icmplen < ICMP_MASKLEN) {
575 ICMP_STATINC(ICMP_STAT_BADLEN);
576 break;
577 }
578 if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
579 in_nullhost(ip->ip_dst))
580 icmpdst.sin_addr = ip->ip_src;
581 else
582 icmpdst.sin_addr = ip->ip_dst;
583 ss = pserialize_read_enter();
584 rcvif = m_get_rcvif(m, &s);
585 ifa = ifaof_ifpforaddr(sintosa(&icmpdst), rcvif);
586 m_put_rcvif(rcvif, &s);
587 if (ifa == NULL) {
588 pserialize_read_exit(ss);
589 break;
590 }
591 ia = ifatoia(ifa);
592 icp->icmp_type = ICMP_MASKREPLY;
593 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
594 if (in_nullhost(ip->ip_src)) {
595 if (ia->ia_ifp->if_flags & IFF_BROADCAST)
596 ip->ip_src = ia->ia_broadaddr.sin_addr;
597 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
598 ip->ip_src = ia->ia_dstaddr.sin_addr;
599 }
600 pserialize_read_exit(ss);
601reflect:
602 {
603 uint64_t *icps = percpu_getref(icmpstat_percpu);
604 icps[ICMP_STAT_REFLECT]++;
605 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++;
606 percpu_putref(icmpstat_percpu);
607 }
608 icmp_reflect(m);
609 return;
610 }
611
612 case ICMP_REDIRECT:
613 if (code > 3)
614 goto badcode;
615 if (icmp_rediraccept == 0)
616 goto freeit;
617 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
618 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
619 ICMP_STATINC(ICMP_STAT_BADLEN);
620 break;
621 }
622 /*
623 * Short circuit routing redirects to force
624 * immediate change in the kernel's routing
625 * tables. The message is also handed to anyone
626 * listening on a raw socket (e.g. the routing
627 * daemon for use in updating its tables).
628 */
629 icmpgw.sin_addr = ip->ip_src;
630 icmpdst.sin_addr = icp->icmp_gwaddr;
631#ifdef ICMPPRINTFS
632 if (icmpprintfs) {
633 char gbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN];
634 printf("redirect dst `%s' to `%s'\n",
635 IN_PRINT(dbuf, &icp->icmp_ip.ip_dst),
636 IN_PRINT(gbuf, &icp->icmp_gwaddr));
637 }
638#endif
639 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
640 rt = NULL;
641 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst),
642 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt);
643 if (rt != NULL && icmp_redirtimeout != 0) {
644 i = rt_timer_add(rt, icmp_redirect_timeout,
645 icmp_redirect_timeout_q);
646 if (i) {
647 char buf[INET_ADDRSTRLEN];
648 log(LOG_ERR, "ICMP: redirect failed to "
649 "register timeout for route to %s, "
650 "code %d\n",
651 IN_PRINT(buf, &icp->icmp_ip.ip_dst), i);
652 }
653 }
654 if (rt != NULL)
655 rtfree(rt);
656
657 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc));
658#if defined(IPSEC)
659 if (ipsec_used)
660 key_sa_routechange((struct sockaddr *)&icmpsrc);
661#endif
662 break;
663
664 /*
665 * No kernel processing for the following;
666 * just fall through to send to raw listener.
667 */
668 case ICMP_ECHOREPLY:
669 case ICMP_ROUTERADVERT:
670 case ICMP_ROUTERSOLICIT:
671 case ICMP_TSTAMPREPLY:
672 case ICMP_IREQREPLY:
673 case ICMP_MASKREPLY:
674 default:
675 break;
676 }
677
678raw:
679 rip_input(m, hlen, proto);
680 return;
681
682freeit:
683 m_freem(m);
684 return;
685}
686
687/*
688 * Reflect the ip packet back to the source
689 */
690void
691icmp_reflect(struct mbuf *m)
692{
693 struct ip *ip = mtod(m, struct ip *);
694 struct in_ifaddr *ia;
695 struct ifaddr *ifa;
696 struct sockaddr_in *sin;
697 struct in_addr t;
698 struct mbuf *opts = NULL;
699 int optlen = (ip->ip_hl << 2) - sizeof(struct ip);
700 struct ifnet *rcvif;
701 struct psref psref, psref_ia;
702 int s;
703 int bound;
704
705 bound = curlwp_bind();
706
707 if (!in_canforward(ip->ip_src) &&
708 ((ip->ip_src.s_addr & IN_CLASSA_NET) !=
709 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
710 m_freem(m); /* Bad return address */
711 goto done; /* ip_output() will check for broadcast */
712 }
713 t = ip->ip_dst;
714 ip->ip_dst = ip->ip_src;
715 /*
716 * If the incoming packet was addressed directly to us, use
717 * dst as the src for the reply. Otherwise (broadcast or
718 * anonymous), use an address which corresponds to the
719 * incoming interface, with a preference for the address which
720 * corresponds to the route to the destination of the ICMP.
721 */
722
723 /* Look for packet addressed to us */
724 ia = in_get_ia_psref(t, &psref_ia);
725 if (ia && (ia->ia4_flags & IN_IFF_NOTREADY)) {
726 ia4_release(ia, &psref_ia);
727 ia = NULL;
728 }
729
730 rcvif = m_get_rcvif_psref(m, &psref);
731
732 /* look for packet sent to broadcast address */
733 if (ia == NULL && rcvif &&
734 (rcvif->if_flags & IFF_BROADCAST)) {
735 s = pserialize_read_enter();
736 IFADDR_READER_FOREACH(ifa, rcvif) {
737 if (ifa->ifa_addr->sa_family != AF_INET)
738 continue;
739 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) {
740 ia = ifatoia(ifa);
741 if ((ia->ia4_flags & IN_IFF_NOTREADY) == 0)
742 break;
743 ia = NULL;
744 }
745 }
746 if (ia != NULL)
747 ia4_acquire(ia, &psref_ia);
748 pserialize_read_exit(s);
749 }
750
751 sin = ia ? &ia->ia_addr : NULL;
752
753 icmpdst.sin_addr = t;
754
755 /*
756 * if the packet is addressed somewhere else, compute the
757 * source address for packets routed back to the source, and
758 * use that, if it's an address on the interface which
759 * received the packet
760 */
761 if (sin == NULL && rcvif) {
762 struct sockaddr_in sin_dst;
763 struct route icmproute;
764 int errornum;
765
766 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0);
767 memset(&icmproute, 0, sizeof(icmproute));
768 errornum = 0;
769 ia = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum,
770 &psref_ia);
771 /* errornum is never used */
772 rtcache_free(&icmproute);
773 /* check to make sure sin is a source address on rcvif */
774 if (ia != NULL) {
775 sin = &ia->ia_addr;
776 t = sin->sin_addr;
777 sin = NULL;
778 ia4_release(ia, &psref_ia);
779 ia = in_get_ia_on_iface_psref(t, rcvif, &psref_ia);
780 if (ia != NULL)
781 sin = &ia->ia_addr;
782 }
783 }
784
785 /*
786 * if it was not addressed to us, but the route doesn't go out
787 * the source interface, pick an address on the source
788 * interface. This can happen when routing is asymmetric, or
789 * when the incoming packet was encapsulated
790 */
791 if (sin == NULL && rcvif) {
792 KASSERT(ia == NULL);
793 s = pserialize_read_enter();
794 IFADDR_READER_FOREACH(ifa, rcvif) {
795 if (ifa->ifa_addr->sa_family != AF_INET)
796 continue;
797 sin = &(ifatoia(ifa)->ia_addr);
798 ia = ifatoia(ifa);
799 ia4_acquire(ia, &psref_ia);
800 break;
801 }
802 pserialize_read_exit(s);
803 }
804
805 m_put_rcvif_psref(rcvif, &psref);
806
807 /*
808 * The following happens if the packet was not addressed to us,
809 * and was received on an interface with no IP address:
810 * We find the first AF_INET address on the first non-loopback
811 * interface.
812 */
813 if (sin == NULL) {
814 KASSERT(ia == NULL);
815 s = pserialize_read_enter();
816 IN_ADDRLIST_READER_FOREACH(ia) {
817 if (ia->ia_ifp->if_flags & IFF_LOOPBACK)
818 continue;
819 sin = &ia->ia_addr;
820 ia4_acquire(ia, &psref_ia);
821 break;
822 }
823 pserialize_read_exit(s);
824 }
825
826 /*
827 * If we still didn't find an address, punt. We could have an
828 * interface up (and receiving packets) with no address.
829 */
830 if (sin == NULL) {
831 KASSERT(ia == NULL);
832 m_freem(m);
833 goto done;
834 }
835
836 ip->ip_src = sin->sin_addr;
837 ip->ip_ttl = MAXTTL;
838
839 if (ia != NULL)
840 ia4_release(ia, &psref_ia);
841
842 if (optlen > 0) {
843 u_char *cp;
844 int opt, cnt;
845 u_int len;
846
847 /*
848 * Retrieve any source routing from the incoming packet;
849 * add on any record-route or timestamp options.
850 */
851 cp = (u_char *) (ip + 1);
852 if ((opts = ip_srcroute()) == NULL &&
853 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) {
854 MCLAIM(opts, m->m_owner);
855 opts->m_len = sizeof(struct in_addr);
856 *mtod(opts, struct in_addr *) = zeroin_addr;
857 }
858 if (opts) {
859#ifdef ICMPPRINTFS
860 if (icmpprintfs)
861 printf("icmp_reflect optlen %d rt %d => ",
862 optlen, opts->m_len);
863#endif
864 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
865 opt = cp[IPOPT_OPTVAL];
866 if (opt == IPOPT_EOL)
867 break;
868 if (opt == IPOPT_NOP)
869 len = 1;
870 else {
871 if (cnt < IPOPT_OLEN + sizeof(*cp))
872 break;
873 len = cp[IPOPT_OLEN];
874 if (len < IPOPT_OLEN + sizeof(*cp) ||
875 len > cnt)
876 break;
877 }
878 /*
879 * Should check for overflow, but it "can't happen"
880 */
881 if (opt == IPOPT_RR || opt == IPOPT_TS ||
882 opt == IPOPT_SECURITY) {
883 memmove(mtod(opts, char *) + opts->m_len,
884 cp, len);
885 opts->m_len += len;
886 }
887 }
888 /* Terminate & pad, if necessary */
889 if ((cnt = opts->m_len % 4) != 0) {
890 for (; cnt < 4; cnt++) {
891 *(mtod(opts, char *) + opts->m_len) =
892 IPOPT_EOL;
893 opts->m_len++;
894 }
895 }
896#ifdef ICMPPRINTFS
897 if (icmpprintfs)
898 printf("%d\n", opts->m_len);
899#endif
900 }
901 /*
902 * Now strip out original options by copying rest of first
903 * mbuf's data back, and adjust the IP length.
904 */
905 ip->ip_len = htons(ntohs(ip->ip_len) - optlen);
906 ip->ip_hl = sizeof(struct ip) >> 2;
907 m->m_len -= optlen;
908 if (m->m_flags & M_PKTHDR)
909 m->m_pkthdr.len -= optlen;
910 optlen += sizeof(struct ip);
911 memmove(ip + 1, (char *)ip + optlen,
912 (unsigned)(m->m_len - sizeof(struct ip)));
913 }
914 m_tag_delete_nonpersistent(m);
915 m->m_flags &= ~(M_BCAST|M_MCAST);
916
917 /*
918 * Clear any in-bound checksum flags for this packet.
919 */
920 if (m->m_flags & M_PKTHDR)
921 m->m_pkthdr.csum_flags = 0;
922
923 icmp_send(m, opts);
924done:
925 curlwp_bindx(bound);
926 if (opts)
927 (void)m_free(opts);
928}
929
930/*
931 * Send an icmp packet back to the ip level,
932 * after supplying a checksum.
933 */
934void
935icmp_send(struct mbuf *m, struct mbuf *opts)
936{
937 struct ip *ip = mtod(m, struct ip *);
938 int hlen;
939 struct icmp *icp;
940
941 hlen = ip->ip_hl << 2;
942 m->m_data += hlen;
943 m->m_len -= hlen;
944 icp = mtod(m, struct icmp *);
945 icp->icmp_cksum = 0;
946 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen);
947 m->m_data -= hlen;
948 m->m_len += hlen;
949#ifdef ICMPPRINTFS
950 if (icmpprintfs) {
951 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN];
952 printf("icmp_send to destination `%s' from `%s'\n",
953 IN_PRINT(dbuf, &ip->ip_dst), IN_PRINT(sbuf, &ip->ip_src));
954 }
955#endif
956 (void)ip_output(m, opts, NULL, 0, NULL, NULL);
957}
958
959n_time
960iptime(void)
961{
962 struct timeval atv;
963 u_long t;
964
965 microtime(&atv);
966 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
967 return (htonl(t));
968}
969
970/*
971 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures
972 * that the new value is in the correct range.
973 */
974static int
975sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS)
976{
977 int error, t;
978 struct sysctlnode node;
979
980 node = *rnode;
981 node.sysctl_data = &t;
982 t = icmpreturndatabytes;
983 error = sysctl_lookup(SYSCTLFN_CALL(&node));
984 if (error || newp == NULL)
985 return (error);
986
987 if (t < 8 || t > 512)
988 return (EINVAL);
989 icmpreturndatabytes = t;
990
991 return (0);
992}
993
994/*
995 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that
996 * the given value is not less than zero and then resets the timeout
997 * queue.
998 */
999static int
1000sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS)
1001{
1002 int error, tmp;
1003 struct sysctlnode node;
1004
1005 node = *rnode;
1006 node.sysctl_data = &tmp;
1007 tmp = icmp_redirtimeout;
1008 error = sysctl_lookup(SYSCTLFN_CALL(&node));
1009 if (error || newp == NULL)
1010 return (error);
1011 if (tmp < 0)
1012 return (EINVAL);
1013 icmp_redirtimeout = tmp;
1014
1015 /*
1016 * was it a *defined* side-effect that anyone even *reading*
1017 * this value causes these things to happen?
1018 */
1019 if (icmp_redirect_timeout_q != NULL) {
1020 if (icmp_redirtimeout == 0) {
1021 rt_timer_queue_destroy(icmp_redirect_timeout_q);
1022 icmp_redirect_timeout_q = NULL;
1023 } else {
1024 rt_timer_queue_change(icmp_redirect_timeout_q,
1025 icmp_redirtimeout);
1026 }
1027 } else if (icmp_redirtimeout > 0) {
1028 icmp_redirect_timeout_q =
1029 rt_timer_queue_create(icmp_redirtimeout);
1030 }
1031
1032 return (0);
1033}
1034
1035static int
1036sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS)
1037{
1038
1039 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS));
1040}
1041
1042static void
1043sysctl_netinet_icmp_setup(struct sysctllog **clog)
1044{
1045
1046 sysctl_createv(clog, 0, NULL, NULL,
1047 CTLFLAG_PERMANENT,
1048 CTLTYPE_NODE, "inet", NULL,
1049 NULL, 0, NULL, 0,
1050 CTL_NET, PF_INET, CTL_EOL);
1051 sysctl_createv(clog, 0, NULL, NULL,
1052 CTLFLAG_PERMANENT,
1053 CTLTYPE_NODE, "icmp",
1054 SYSCTL_DESCR("ICMPv4 related settings"),
1055 NULL, 0, NULL, 0,
1056 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL);
1057
1058 sysctl_createv(clog, 0, NULL, NULL,
1059 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1060 CTLTYPE_INT, "maskrepl",
1061 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"),
1062 NULL, 0, &icmpmaskrepl, 0,
1063 CTL_NET, PF_INET, IPPROTO_ICMP,
1064 ICMPCTL_MASKREPL, CTL_EOL);
1065 sysctl_createv(clog, 0, NULL, NULL,
1066 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1067 CTLTYPE_INT, "returndatabytes",
1068 SYSCTL_DESCR("Number of bytes to return in an ICMP "
1069 "error message"),
1070 sysctl_net_inet_icmp_returndatabytes, 0,
1071 &icmpreturndatabytes, 0,
1072 CTL_NET, PF_INET, IPPROTO_ICMP,
1073 ICMPCTL_RETURNDATABYTES, CTL_EOL);
1074 sysctl_createv(clog, 0, NULL, NULL,
1075 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1076 CTLTYPE_INT, "errppslimit",
1077 SYSCTL_DESCR("Maximum number of outgoing ICMP error "
1078 "messages per second"),
1079 NULL, 0, &icmperrppslim, 0,
1080 CTL_NET, PF_INET, IPPROTO_ICMP,
1081 ICMPCTL_ERRPPSLIMIT, CTL_EOL);
1082 sysctl_createv(clog, 0, NULL, NULL,
1083 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1084 CTLTYPE_INT, "rediraccept",
1085 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"),
1086 NULL, 0, &icmp_rediraccept, 0,
1087 CTL_NET, PF_INET, IPPROTO_ICMP,
1088 ICMPCTL_REDIRACCEPT, CTL_EOL);
1089 sysctl_createv(clog, 0, NULL, NULL,
1090 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1091 CTLTYPE_INT, "redirtimeout",
1092 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated "
1093 "routes"),
1094 sysctl_net_inet_icmp_redirtimeout, 0,
1095 &icmp_redirtimeout, 0,
1096 CTL_NET, PF_INET, IPPROTO_ICMP,
1097 ICMPCTL_REDIRTIMEOUT, CTL_EOL);
1098 sysctl_createv(clog, 0, NULL, NULL,
1099 CTLFLAG_PERMANENT,
1100 CTLTYPE_STRUCT, "stats",
1101 SYSCTL_DESCR("ICMP statistics"),
1102 sysctl_net_inet_icmp_stats, 0, NULL, 0,
1103 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS,
1104 CTL_EOL);
1105 sysctl_createv(clog, 0, NULL, NULL,
1106 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1107 CTLTYPE_INT, "bmcastecho",
1108 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP "
1109 "message to the broadcast or multicast"),
1110 NULL, 0, &icmpbmcastecho, 0,
1111 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO,
1112 CTL_EOL);
1113}
1114
1115void
1116icmp_statinc(u_int stat)
1117{
1118
1119 KASSERT(stat < ICMP_NSTATS);
1120 ICMP_STATINC(stat);
1121}
1122
1123/* Table of common MTUs: */
1124
1125static const u_int mtu_table[] = {
1126 65535, 65280, 32000, 17914, 9180, 8166,
1127 4352, 2002, 1492, 1006, 508, 296, 68, 0
1128};
1129
1130void
1131icmp_mtudisc(struct icmp *icp, struct in_addr faddr)
1132{
1133 struct icmp_mtudisc_callback *mc;
1134 struct sockaddr *dst = sintosa(&icmpsrc);
1135 struct rtentry *rt;
1136 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */
1137 int error;
1138
1139 rt = rtalloc1(dst, 1);
1140 if (rt == NULL)
1141 return;
1142
1143 /* If we didn't get a host route, allocate one */
1144
1145 if ((rt->rt_flags & RTF_HOST) == 0) {
1146 struct rtentry *nrt;
1147
1148 error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL,
1149 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
1150 if (error) {
1151 rtfree(rt);
1152 return;
1153 }
1154 nrt->rt_rmx = rt->rt_rmx;
1155 rtfree(rt);
1156 rt = nrt;
1157 }
1158 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q);
1159 if (error) {
1160 rtfree(rt);
1161 return;
1162 }
1163
1164 if (mtu == 0) {
1165 int i = 0;
1166
1167 mtu = ntohs(icp->icmp_ip.ip_len);
1168 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */
1169 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0)
1170 mtu -= (icp->icmp_ip.ip_hl << 2);
1171
1172 /* If we still can't guess a value, try the route */
1173
1174 if (mtu == 0) {
1175 mtu = rt->rt_rmx.rmx_mtu;
1176
1177 /* If no route mtu, default to the interface mtu */
1178
1179 if (mtu == 0)
1180 mtu = rt->rt_ifp->if_mtu;
1181 }
1182
1183 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++)
1184 if (mtu > mtu_table[i]) {
1185 mtu = mtu_table[i];
1186 break;
1187 }
1188 }
1189
1190 /*
1191 * XXX: RTV_MTU is overloaded, since the admin can set it
1192 * to turn off PMTU for a route, and the kernel can
1193 * set it to indicate a serious problem with PMTU
1194 * on a route. We should be using a separate flag
1195 * for the kernel to indicate this.
1196 */
1197
1198 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
1199 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu)
1200 rt->rt_rmx.rmx_locks |= RTV_MTU;
1201 else if (rt->rt_rmx.rmx_mtu > mtu ||
1202 rt->rt_rmx.rmx_mtu == 0) {
1203 ICMP_STATINC(ICMP_STAT_PMTUCHG);
1204 rt->rt_rmx.rmx_mtu = mtu;
1205 }
1206 }
1207
1208 if (rt)
1209 rtfree(rt);
1210
1211 /*
1212 * Notify protocols that the MTU for this destination
1213 * has changed.
1214 */
1215 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL;
1216 mc = LIST_NEXT(mc, mc_list))
1217 (*mc->mc_func)(faddr);
1218}
1219
1220/*
1221 * Return the next larger or smaller MTU plateau (table from RFC 1191)
1222 * given current value MTU. If DIR is less than zero, a larger plateau
1223 * is returned; otherwise, a smaller value is returned.
1224 */
1225u_int
1226ip_next_mtu(u_int mtu, int dir) /* XXX */
1227{
1228 int i;
1229
1230 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) {
1231 if (mtu >= mtu_table[i])
1232 break;
1233 }
1234
1235 if (dir < 0) {
1236 if (i == 0) {
1237 return 0;
1238 } else {
1239 return mtu_table[i - 1];
1240 }
1241 } else {
1242 if (mtu_table[i] == 0) {
1243 return 0;
1244 } else if (mtu > mtu_table[i]) {
1245 return mtu_table[i];
1246 } else {
1247 return mtu_table[i + 1];
1248 }
1249 }
1250}
1251
1252static void
1253icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r)
1254{
1255
1256 KASSERT(rt != NULL);
1257 rt_assert_referenced(rt);
1258
1259 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
1260 (RTF_DYNAMIC | RTF_HOST)) {
1261 rtrequest(RTM_DELETE, rt_getkey(rt),
1262 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
1263 } else {
1264 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
1265 rt->rt_rmx.rmx_mtu = 0;
1266 }
1267 }
1268}
1269
1270static void
1271icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r)
1272{
1273
1274 KASSERT(rt != NULL);
1275 rt_assert_referenced(rt);
1276
1277 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
1278 (RTF_DYNAMIC | RTF_HOST)) {
1279 rtrequest(RTM_DELETE, rt_getkey(rt),
1280 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
1281 }
1282}
1283
1284/*
1285 * Perform rate limit check.
1286 * Returns 0 if it is okay to send the icmp packet.
1287 * Returns 1 if the router SHOULD NOT send this icmp packet due to rate
1288 * limitation.
1289 *
1290 * XXX per-destination/type check necessary?
1291 */
1292int
1293icmp_ratelimit(const struct in_addr *dst, const int type,
1294 const int code)
1295{
1296
1297 /* PPS limit */
1298 if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count,
1299 icmperrppslim)) {
1300 /* The packet is subject to rate limit */
1301 return 1;
1302 }
1303
1304 /* okay to send */
1305 return 0;
1306}
1307