1 /* $NetBSD: ip_icmp.c,v 1.150 2016/07/08 04:33:30 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 1.150 2016/07/08 04:33:30 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
139 int icmpmaskrepl = 0;
140 int icmpbmcastecho = 0;
141 #ifdef ICMPPRINTFS
142 int icmpprintfs = 0;
143 #endif
144 int icmpreturndatabytes = 8;
145
146 percpu_t *icmpstat_percpu;
147
148 /*
149 * List of callbacks to notify when Path MTU changes are made.
150 */
151 struct icmp_mtudisc_callback {
152 LIST_ENTRY(icmp_mtudisc_callback) mc_list;
153 void (*mc_func)(struct in_addr);
154 };
155
156 LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks =
157 LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks);
158
159 #if 0
160 static u_int ip_next_mtu(u_int, int);
161 #else
162 /*static*/ u_int ip_next_mtu(u_int, int);
163 #endif
164
165 extern int icmperrppslim;
166 static int icmperrpps_count = 0;
167 static struct timeval icmperrppslim_last;
168 static int icmp_rediraccept = 1;
169 static int icmp_redirtimeout = 600;
170 static struct rttimer_queue *icmp_redirect_timeout_q = NULL;
171
172 static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *);
173 static void icmp_redirect_timeout(struct rtentry *, struct rttimer *);
174
175 static void sysctl_netinet_icmp_setup(struct sysctllog **);
176
177 void
icmp_init(void)178 icmp_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 */
198 void
icmp_mtudisc_callback_register(void (* func)(struct in_addr))199 icmp_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 */
218 void
icmp_error(struct mbuf * n,int type,int code,n_long dest,int destmtu)219 icmp_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
362 freeit:
363 m_freem(n);
364 }
365
366 struct sockaddr_in icmpsrc = {
367 .sin_len = sizeof (struct sockaddr_in),
368 .sin_family = AF_INET,
369 };
370 static struct sockaddr_in icmpdst = {
371 .sin_len = sizeof (struct sockaddr_in),
372 .sin_family = AF_INET,
373 };
374 static struct sockaddr_in icmpgw = {
375 .sin_len = sizeof (struct sockaddr_in),
376 .sin_family = AF_INET,
377 };
378 struct sockaddr_in icmpmask = {
379 .sin_len = 8,
380 .sin_family = 0,
381 };
382
383 /*
384 * Process a received ICMP message.
385 */
386 void
icmp_input(struct mbuf * m,...)387 icmp_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;
566
567 if (icmpmaskrepl == 0)
568 break;
569 /*
570 * We are not able to respond with all ones broadcast
571 * unless we receive it over a point-to-point interface.
572 */
573 if (icmplen < ICMP_MASKLEN) {
574 ICMP_STATINC(ICMP_STAT_BADLEN);
575 break;
576 }
577 if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
578 in_nullhost(ip->ip_dst))
579 icmpdst.sin_addr = ip->ip_src;
580 else
581 icmpdst.sin_addr = ip->ip_dst;
582 rcvif = m_get_rcvif(m, &s);
583 ia = ifatoia(ifaof_ifpforaddr(sintosa(&icmpdst),
584 rcvif));
585 m_put_rcvif(rcvif, &s);
586 if (ia == 0)
587 break;
588 icp->icmp_type = ICMP_MASKREPLY;
589 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
590 if (in_nullhost(ip->ip_src)) {
591 if (ia->ia_ifp->if_flags & IFF_BROADCAST)
592 ip->ip_src = ia->ia_broadaddr.sin_addr;
593 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
594 ip->ip_src = ia->ia_dstaddr.sin_addr;
595 }
596 reflect:
597 {
598 uint64_t *icps = percpu_getref(icmpstat_percpu);
599 icps[ICMP_STAT_REFLECT]++;
600 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++;
601 percpu_putref(icmpstat_percpu);
602 }
603 icmp_reflect(m);
604 return;
605 }
606
607 case ICMP_REDIRECT:
608 if (code > 3)
609 goto badcode;
610 if (icmp_rediraccept == 0)
611 goto freeit;
612 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) ||
613 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
614 ICMP_STATINC(ICMP_STAT_BADLEN);
615 break;
616 }
617 /*
618 * Short circuit routing redirects to force
619 * immediate change in the kernel's routing
620 * tables. The message is also handed to anyone
621 * listening on a raw socket (e.g. the routing
622 * daemon for use in updating its tables).
623 */
624 icmpgw.sin_addr = ip->ip_src;
625 icmpdst.sin_addr = icp->icmp_gwaddr;
626 #ifdef ICMPPRINTFS
627 if (icmpprintfs) {
628 char gbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN];
629 printf("redirect dst `%s' to `%s'\n",
630 IN_PRINT(dbuf, &icp->icmp_ip.ip_dst),
631 IN_PRINT(gbuf, &icp->icmp_gwaddr));
632 }
633 #endif
634 icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
635 rt = NULL;
636 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst),
637 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt);
638 if (rt != NULL && icmp_redirtimeout != 0) {
639 i = rt_timer_add(rt, icmp_redirect_timeout,
640 icmp_redirect_timeout_q);
641 if (i) {
642 char buf[INET_ADDRSTRLEN];
643 log(LOG_ERR, "ICMP: redirect failed to "
644 "register timeout for route to %s, "
645 "code %d\n",
646 IN_PRINT(buf, &icp->icmp_ip.ip_dst), i);
647 }
648 }
649 if (rt != NULL)
650 rtfree(rt);
651
652 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc));
653 #if defined(IPSEC)
654 if (ipsec_used)
655 key_sa_routechange((struct sockaddr *)&icmpsrc);
656 #endif
657 break;
658
659 /*
660 * No kernel processing for the following;
661 * just fall through to send to raw listener.
662 */
663 case ICMP_ECHOREPLY:
664 case ICMP_ROUTERADVERT:
665 case ICMP_ROUTERSOLICIT:
666 case ICMP_TSTAMPREPLY:
667 case ICMP_IREQREPLY:
668 case ICMP_MASKREPLY:
669 default:
670 break;
671 }
672
673 raw:
674 rip_input(m, hlen, proto);
675 return;
676
677 freeit:
678 m_freem(m);
679 return;
680 }
681
682 /*
683 * Reflect the ip packet back to the source
684 */
685 void
icmp_reflect(struct mbuf * m)686 icmp_reflect(struct mbuf *m)
687 {
688 struct ip *ip = mtod(m, struct ip *);
689 struct in_ifaddr *ia;
690 struct ifaddr *ifa;
691 struct sockaddr_in *sin;
692 struct in_addr t;
693 struct mbuf *opts = NULL;
694 int optlen = (ip->ip_hl << 2) - sizeof(struct ip);
695 struct ifnet *rcvif;
696 struct psref psref;
697
698 if (!in_canforward(ip->ip_src) &&
699 ((ip->ip_src.s_addr & IN_CLASSA_NET) !=
700 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
701 m_freem(m); /* Bad return address */
702 goto done; /* ip_output() will check for broadcast */
703 }
704 t = ip->ip_dst;
705 ip->ip_dst = ip->ip_src;
706 /*
707 * If the incoming packet was addressed directly to us, use
708 * dst as the src for the reply. Otherwise (broadcast or
709 * anonymous), use an address which corresponds to the
710 * incoming interface, with a preference for the address which
711 * corresponds to the route to the destination of the ICMP.
712 */
713
714 /* Look for packet addressed to us */
715 ia = in_get_ia(t);
716 if (ia && (ia->ia4_flags & IN_IFF_NOTREADY))
717 ia = NULL;
718
719 rcvif = m_get_rcvif_psref(m, &psref);
720
721 /* look for packet sent to broadcast address */
722 if (ia == NULL && rcvif &&
723 (rcvif->if_flags & IFF_BROADCAST)) {
724 IFADDR_READER_FOREACH(ifa, rcvif) {
725 if (ifa->ifa_addr->sa_family != AF_INET)
726 continue;
727 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) {
728 ia = ifatoia(ifa);
729 if ((ia->ia4_flags & IN_IFF_NOTREADY) == 0)
730 break;
731 ia = NULL;
732 }
733 }
734 }
735
736 sin = ia ? &ia->ia_addr : NULL;
737
738 icmpdst.sin_addr = t;
739
740 /*
741 * if the packet is addressed somewhere else, compute the
742 * source address for packets routed back to the source, and
743 * use that, if it's an address on the interface which
744 * received the packet
745 */
746 if (sin == NULL && rcvif) {
747 struct sockaddr_in sin_dst;
748 struct route icmproute;
749 int errornum;
750
751 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0);
752 memset(&icmproute, 0, sizeof(icmproute));
753 errornum = 0;
754 sin = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum);
755 /* errornum is never used */
756 rtcache_free(&icmproute);
757 /* check to make sure sin is a source address on rcvif */
758 if (sin) {
759 t = sin->sin_addr;
760 sin = NULL;
761 ia = in_get_ia_on_iface(t, rcvif);
762 if (ia != NULL)
763 sin = &ia->ia_addr;
764 }
765 }
766
767 /*
768 * if it was not addressed to us, but the route doesn't go out
769 * the source interface, pick an address on the source
770 * interface. This can happen when routing is asymmetric, or
771 * when the incoming packet was encapsulated
772 */
773 if (sin == NULL && rcvif) {
774 IFADDR_READER_FOREACH(ifa, rcvif) {
775 if (ifa->ifa_addr->sa_family != AF_INET)
776 continue;
777 sin = &(ifatoia(ifa)->ia_addr);
778 break;
779 }
780 }
781
782 m_put_rcvif_psref(rcvif, &psref);
783
784 /*
785 * The following happens if the packet was not addressed to us,
786 * and was received on an interface with no IP address:
787 * We find the first AF_INET address on the first non-loopback
788 * interface.
789 */
790 if (sin == NULL)
791 IN_ADDRLIST_READER_FOREACH(ia) {
792 if (ia->ia_ifp->if_flags & IFF_LOOPBACK)
793 continue;
794 sin = &ia->ia_addr;
795 break;
796 }
797
798 /*
799 * If we still didn't find an address, punt. We could have an
800 * interface up (and receiving packets) with no address.
801 */
802 if (sin == NULL) {
803 m_freem(m);
804 goto done;
805 }
806
807 ip->ip_src = sin->sin_addr;
808 ip->ip_ttl = MAXTTL;
809
810 if (optlen > 0) {
811 u_char *cp;
812 int opt, cnt;
813 u_int len;
814
815 /*
816 * Retrieve any source routing from the incoming packet;
817 * add on any record-route or timestamp options.
818 */
819 cp = (u_char *) (ip + 1);
820 if ((opts = ip_srcroute()) == NULL &&
821 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) {
822 MCLAIM(opts, m->m_owner);
823 opts->m_len = sizeof(struct in_addr);
824 *mtod(opts, struct in_addr *) = zeroin_addr;
825 }
826 if (opts) {
827 #ifdef ICMPPRINTFS
828 if (icmpprintfs)
829 printf("icmp_reflect optlen %d rt %d => ",
830 optlen, opts->m_len);
831 #endif
832 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
833 opt = cp[IPOPT_OPTVAL];
834 if (opt == IPOPT_EOL)
835 break;
836 if (opt == IPOPT_NOP)
837 len = 1;
838 else {
839 if (cnt < IPOPT_OLEN + sizeof(*cp))
840 break;
841 len = cp[IPOPT_OLEN];
842 if (len < IPOPT_OLEN + sizeof(*cp) ||
843 len > cnt)
844 break;
845 }
846 /*
847 * Should check for overflow, but it "can't happen"
848 */
849 if (opt == IPOPT_RR || opt == IPOPT_TS ||
850 opt == IPOPT_SECURITY) {
851 memmove(mtod(opts, char *) + opts->m_len,
852 cp, len);
853 opts->m_len += len;
854 }
855 }
856 /* Terminate & pad, if necessary */
857 if ((cnt = opts->m_len % 4) != 0) {
858 for (; cnt < 4; cnt++) {
859 *(mtod(opts, char *) + opts->m_len) =
860 IPOPT_EOL;
861 opts->m_len++;
862 }
863 }
864 #ifdef ICMPPRINTFS
865 if (icmpprintfs)
866 printf("%d\n", opts->m_len);
867 #endif
868 }
869 /*
870 * Now strip out original options by copying rest of first
871 * mbuf's data back, and adjust the IP length.
872 */
873 ip->ip_len = htons(ntohs(ip->ip_len) - optlen);
874 ip->ip_hl = sizeof(struct ip) >> 2;
875 m->m_len -= optlen;
876 if (m->m_flags & M_PKTHDR)
877 m->m_pkthdr.len -= optlen;
878 optlen += sizeof(struct ip);
879 memmove(ip + 1, (char *)ip + optlen,
880 (unsigned)(m->m_len - sizeof(struct ip)));
881 }
882 m_tag_delete_nonpersistent(m);
883 m->m_flags &= ~(M_BCAST|M_MCAST);
884
885 /*
886 * Clear any in-bound checksum flags for this packet.
887 */
888 if (m->m_flags & M_PKTHDR)
889 m->m_pkthdr.csum_flags = 0;
890
891 icmp_send(m, opts);
892 done:
893 if (opts)
894 (void)m_free(opts);
895 }
896
897 /*
898 * Send an icmp packet back to the ip level,
899 * after supplying a checksum.
900 */
901 void
icmp_send(struct mbuf * m,struct mbuf * opts)902 icmp_send(struct mbuf *m, struct mbuf *opts)
903 {
904 struct ip *ip = mtod(m, struct ip *);
905 int hlen;
906 struct icmp *icp;
907
908 hlen = ip->ip_hl << 2;
909 m->m_data += hlen;
910 m->m_len -= hlen;
911 icp = mtod(m, struct icmp *);
912 icp->icmp_cksum = 0;
913 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen);
914 m->m_data -= hlen;
915 m->m_len += hlen;
916 #ifdef ICMPPRINTFS
917 if (icmpprintfs) {
918 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN];
919 printf("icmp_send to destination `%s' from `%s'\n",
920 IN_PRINT(dbuf, &ip->ip_dst), IN_PRINT(sbuf, &ip->ip_src));
921 }
922 #endif
923 (void)ip_output(m, opts, NULL, 0, NULL, NULL);
924 }
925
926 n_time
iptime(void)927 iptime(void)
928 {
929 struct timeval atv;
930 u_long t;
931
932 microtime(&atv);
933 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000;
934 return (htonl(t));
935 }
936
937 /*
938 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures
939 * that the new value is in the correct range.
940 */
941 static int
sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS)942 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS)
943 {
944 int error, t;
945 struct sysctlnode node;
946
947 node = *rnode;
948 node.sysctl_data = &t;
949 t = icmpreturndatabytes;
950 error = sysctl_lookup(SYSCTLFN_CALL(&node));
951 if (error || newp == NULL)
952 return (error);
953
954 if (t < 8 || t > 512)
955 return (EINVAL);
956 icmpreturndatabytes = t;
957
958 return (0);
959 }
960
961 /*
962 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that
963 * the given value is not less than zero and then resets the timeout
964 * queue.
965 */
966 static int
sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS)967 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS)
968 {
969 int error, tmp;
970 struct sysctlnode node;
971
972 node = *rnode;
973 node.sysctl_data = &tmp;
974 tmp = icmp_redirtimeout;
975 error = sysctl_lookup(SYSCTLFN_CALL(&node));
976 if (error || newp == NULL)
977 return (error);
978 if (tmp < 0)
979 return (EINVAL);
980 icmp_redirtimeout = tmp;
981
982 /*
983 * was it a *defined* side-effect that anyone even *reading*
984 * this value causes these things to happen?
985 */
986 if (icmp_redirect_timeout_q != NULL) {
987 if (icmp_redirtimeout == 0) {
988 rt_timer_queue_destroy(icmp_redirect_timeout_q,
989 true);
990 icmp_redirect_timeout_q = NULL;
991 } else {
992 rt_timer_queue_change(icmp_redirect_timeout_q,
993 icmp_redirtimeout);
994 }
995 } else if (icmp_redirtimeout > 0) {
996 icmp_redirect_timeout_q =
997 rt_timer_queue_create(icmp_redirtimeout);
998 }
999
1000 return (0);
1001 }
1002
1003 static int
sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS)1004 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS)
1005 {
1006
1007 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS));
1008 }
1009
1010 static void
sysctl_netinet_icmp_setup(struct sysctllog ** clog)1011 sysctl_netinet_icmp_setup(struct sysctllog **clog)
1012 {
1013
1014 sysctl_createv(clog, 0, NULL, NULL,
1015 CTLFLAG_PERMANENT,
1016 CTLTYPE_NODE, "inet", NULL,
1017 NULL, 0, NULL, 0,
1018 CTL_NET, PF_INET, CTL_EOL);
1019 sysctl_createv(clog, 0, NULL, NULL,
1020 CTLFLAG_PERMANENT,
1021 CTLTYPE_NODE, "icmp",
1022 SYSCTL_DESCR("ICMPv4 related settings"),
1023 NULL, 0, NULL, 0,
1024 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL);
1025
1026 sysctl_createv(clog, 0, NULL, NULL,
1027 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1028 CTLTYPE_INT, "maskrepl",
1029 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"),
1030 NULL, 0, &icmpmaskrepl, 0,
1031 CTL_NET, PF_INET, IPPROTO_ICMP,
1032 ICMPCTL_MASKREPL, CTL_EOL);
1033 sysctl_createv(clog, 0, NULL, NULL,
1034 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1035 CTLTYPE_INT, "returndatabytes",
1036 SYSCTL_DESCR("Number of bytes to return in an ICMP "
1037 "error message"),
1038 sysctl_net_inet_icmp_returndatabytes, 0,
1039 &icmpreturndatabytes, 0,
1040 CTL_NET, PF_INET, IPPROTO_ICMP,
1041 ICMPCTL_RETURNDATABYTES, CTL_EOL);
1042 sysctl_createv(clog, 0, NULL, NULL,
1043 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1044 CTLTYPE_INT, "errppslimit",
1045 SYSCTL_DESCR("Maximum number of outgoing ICMP error "
1046 "messages per second"),
1047 NULL, 0, &icmperrppslim, 0,
1048 CTL_NET, PF_INET, IPPROTO_ICMP,
1049 ICMPCTL_ERRPPSLIMIT, CTL_EOL);
1050 sysctl_createv(clog, 0, NULL, NULL,
1051 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1052 CTLTYPE_INT, "rediraccept",
1053 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"),
1054 NULL, 0, &icmp_rediraccept, 0,
1055 CTL_NET, PF_INET, IPPROTO_ICMP,
1056 ICMPCTL_REDIRACCEPT, CTL_EOL);
1057 sysctl_createv(clog, 0, NULL, NULL,
1058 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1059 CTLTYPE_INT, "redirtimeout",
1060 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated "
1061 "routes"),
1062 sysctl_net_inet_icmp_redirtimeout, 0,
1063 &icmp_redirtimeout, 0,
1064 CTL_NET, PF_INET, IPPROTO_ICMP,
1065 ICMPCTL_REDIRTIMEOUT, CTL_EOL);
1066 sysctl_createv(clog, 0, NULL, NULL,
1067 CTLFLAG_PERMANENT,
1068 CTLTYPE_STRUCT, "stats",
1069 SYSCTL_DESCR("ICMP statistics"),
1070 sysctl_net_inet_icmp_stats, 0, NULL, 0,
1071 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS,
1072 CTL_EOL);
1073 sysctl_createv(clog, 0, NULL, NULL,
1074 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1075 CTLTYPE_INT, "bmcastecho",
1076 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP "
1077 "message to the broadcast or multicast"),
1078 NULL, 0, &icmpbmcastecho, 0,
1079 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO,
1080 CTL_EOL);
1081 }
1082
1083 void
icmp_statinc(u_int stat)1084 icmp_statinc(u_int stat)
1085 {
1086
1087 KASSERT(stat < ICMP_NSTATS);
1088 ICMP_STATINC(stat);
1089 }
1090
1091 /* Table of common MTUs: */
1092
1093 static const u_int mtu_table[] = {
1094 65535, 65280, 32000, 17914, 9180, 8166,
1095 4352, 2002, 1492, 1006, 508, 296, 68, 0
1096 };
1097
1098 void
icmp_mtudisc(struct icmp * icp,struct in_addr faddr)1099 icmp_mtudisc(struct icmp *icp, struct in_addr faddr)
1100 {
1101 struct icmp_mtudisc_callback *mc;
1102 struct sockaddr *dst = sintosa(&icmpsrc);
1103 struct rtentry *rt;
1104 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */
1105 int error;
1106
1107 rt = rtalloc1(dst, 1);
1108 if (rt == NULL)
1109 return;
1110
1111 /* If we didn't get a host route, allocate one */
1112
1113 if ((rt->rt_flags & RTF_HOST) == 0) {
1114 struct rtentry *nrt;
1115
1116 error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL,
1117 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
1118 if (error) {
1119 rtfree(rt);
1120 return;
1121 }
1122 nrt->rt_rmx = rt->rt_rmx;
1123 rtfree(rt);
1124 rt = nrt;
1125 }
1126 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q);
1127 if (error) {
1128 rtfree(rt);
1129 return;
1130 }
1131
1132 if (mtu == 0) {
1133 int i = 0;
1134
1135 mtu = ntohs(icp->icmp_ip.ip_len);
1136 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */
1137 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0)
1138 mtu -= (icp->icmp_ip.ip_hl << 2);
1139
1140 /* If we still can't guess a value, try the route */
1141
1142 if (mtu == 0) {
1143 mtu = rt->rt_rmx.rmx_mtu;
1144
1145 /* If no route mtu, default to the interface mtu */
1146
1147 if (mtu == 0)
1148 mtu = rt->rt_ifp->if_mtu;
1149 }
1150
1151 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++)
1152 if (mtu > mtu_table[i]) {
1153 mtu = mtu_table[i];
1154 break;
1155 }
1156 }
1157
1158 /*
1159 * XXX: RTV_MTU is overloaded, since the admin can set it
1160 * to turn off PMTU for a route, and the kernel can
1161 * set it to indicate a serious problem with PMTU
1162 * on a route. We should be using a separate flag
1163 * for the kernel to indicate this.
1164 */
1165
1166 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
1167 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu)
1168 rt->rt_rmx.rmx_locks |= RTV_MTU;
1169 else if (rt->rt_rmx.rmx_mtu > mtu ||
1170 rt->rt_rmx.rmx_mtu == 0) {
1171 ICMP_STATINC(ICMP_STAT_PMTUCHG);
1172 rt->rt_rmx.rmx_mtu = mtu;
1173 }
1174 }
1175
1176 if (rt)
1177 rtfree(rt);
1178
1179 /*
1180 * Notify protocols that the MTU for this destination
1181 * has changed.
1182 */
1183 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL;
1184 mc = LIST_NEXT(mc, mc_list))
1185 (*mc->mc_func)(faddr);
1186 }
1187
1188 /*
1189 * Return the next larger or smaller MTU plateau (table from RFC 1191)
1190 * given current value MTU. If DIR is less than zero, a larger plateau
1191 * is returned; otherwise, a smaller value is returned.
1192 */
1193 u_int
ip_next_mtu(u_int mtu,int dir)1194 ip_next_mtu(u_int mtu, int dir) /* XXX */
1195 {
1196 int i;
1197
1198 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) {
1199 if (mtu >= mtu_table[i])
1200 break;
1201 }
1202
1203 if (dir < 0) {
1204 if (i == 0) {
1205 return 0;
1206 } else {
1207 return mtu_table[i - 1];
1208 }
1209 } else {
1210 if (mtu_table[i] == 0) {
1211 return 0;
1212 } else if (mtu > mtu_table[i]) {
1213 return mtu_table[i];
1214 } else {
1215 return mtu_table[i + 1];
1216 }
1217 }
1218 }
1219
1220 static void
icmp_mtudisc_timeout(struct rtentry * rt,struct rttimer * r)1221 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r)
1222 {
1223
1224 KASSERT(rt != NULL);
1225 rt_assert_referenced(rt);
1226
1227 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
1228 (RTF_DYNAMIC | RTF_HOST)) {
1229 rtrequest(RTM_DELETE, rt_getkey(rt),
1230 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
1231 } else {
1232 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
1233 rt->rt_rmx.rmx_mtu = 0;
1234 }
1235 }
1236 }
1237
1238 static void
icmp_redirect_timeout(struct rtentry * rt,struct rttimer * r)1239 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r)
1240 {
1241
1242 KASSERT(rt != NULL);
1243 rt_assert_referenced(rt);
1244
1245 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
1246 (RTF_DYNAMIC | RTF_HOST)) {
1247 rtrequest(RTM_DELETE, rt_getkey(rt),
1248 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
1249 }
1250 }
1251
1252 /*
1253 * Perform rate limit check.
1254 * Returns 0 if it is okay to send the icmp packet.
1255 * Returns 1 if the router SHOULD NOT send this icmp packet due to rate
1256 * limitation.
1257 *
1258 * XXX per-destination/type check necessary?
1259 */
1260 int
icmp_ratelimit(const struct in_addr * dst,const int type,const int code)1261 icmp_ratelimit(const struct in_addr *dst, const int type,
1262 const int code)
1263 {
1264
1265 /* PPS limit */
1266 if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count,
1267 icmperrppslim)) {
1268 /* The packet is subject to rate limit */
1269 return 1;
1270 }
1271
1272 /* okay to send */
1273 return 0;
1274 }
1275