FreeBSD/Linux Kernel Cross Reference
sys/netinet6/icmp6.c
1 /* $FreeBSD: releng/5.3/sys/netinet6/icmp6.c 136588 2004-10-16 08:43:07Z cvs2svn $ */
2 /* $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 /*
34 * Copyright (c) 1982, 1986, 1988, 1993
35 * The Regents of the University of California. All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 4. Neither the name of the University nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 *
61 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
62 */
63
64 #include "opt_inet.h"
65 #include "opt_inet6.h"
66 #include "opt_ipsec.h"
67
68 #include <sys/param.h>
69 #include <sys/domain.h>
70 #include <sys/kernel.h>
71 #include <sys/lock.h>
72 #include <sys/malloc.h>
73 #include <sys/mbuf.h>
74 #include <sys/protosw.h>
75 #include <sys/signalvar.h>
76 #include <sys/socket.h>
77 #include <sys/socketvar.h>
78 #include <sys/sx.h>
79 #include <sys/syslog.h>
80 #include <sys/systm.h>
81 #include <sys/time.h>
82
83 #include <net/if.h>
84 #include <net/if_dl.h>
85 #include <net/if_types.h>
86 #include <net/route.h>
87
88 #include <netinet/in.h>
89 #include <netinet/in_pcb.h>
90 #include <netinet/in_var.h>
91 #include <netinet/ip6.h>
92 #include <netinet/icmp6.h>
93 #include <netinet/tcp_var.h>
94 #include <netinet6/in6_ifattach.h>
95 #include <netinet6/in6_pcb.h>
96 #include <netinet6/ip6protosw.h>
97 #include <netinet6/ip6_var.h>
98 #include <netinet6/mld6_var.h>
99 #include <netinet6/nd6.h>
100
101 #ifdef IPSEC
102 #include <netinet6/ipsec.h>
103 #include <netkey/key.h>
104 #endif
105
106 #ifdef FAST_IPSEC
107 #include <netipsec/ipsec.h>
108 #include <netipsec/key.h>
109 #endif
110
111 #include <net/net_osdep.h>
112
113 extern struct domain inet6domain;
114
115 struct icmp6stat icmp6stat;
116
117 extern struct inpcbhead ripcb;
118 extern int icmp6errppslim;
119 static int icmp6errpps_count = 0;
120 static struct timeval icmp6errppslim_last;
121 extern int icmp6_nodeinfo;
122
123 static void icmp6_errcount __P((struct icmp6errstat *, int, int));
124 static int icmp6_rip6_input __P((struct mbuf **, int));
125 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
126 static const char *icmp6_redirect_diag __P((struct in6_addr *,
127 struct in6_addr *, struct in6_addr *));
128 static struct mbuf *ni6_input __P((struct mbuf *, int));
129 static struct mbuf *ni6_nametodns __P((const char *, int, int));
130 static int ni6_dnsmatch __P((const char *, int, const char *, int));
131 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
132 struct ifnet **, char *));
133 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
134 struct ifnet *, int));
135 static int icmp6_notify_error __P((struct mbuf *, int, int, int));
136
137 #ifdef COMPAT_RFC1885
138 static struct route_in6 icmp6_reflect_rt;
139 #endif
140
141
142 void
143 icmp6_init()
144 {
145 mld6_init();
146 }
147
148 static void
149 icmp6_errcount(stat, type, code)
150 struct icmp6errstat *stat;
151 int type, code;
152 {
153 switch (type) {
154 case ICMP6_DST_UNREACH:
155 switch (code) {
156 case ICMP6_DST_UNREACH_NOROUTE:
157 stat->icp6errs_dst_unreach_noroute++;
158 return;
159 case ICMP6_DST_UNREACH_ADMIN:
160 stat->icp6errs_dst_unreach_admin++;
161 return;
162 case ICMP6_DST_UNREACH_BEYONDSCOPE:
163 stat->icp6errs_dst_unreach_beyondscope++;
164 return;
165 case ICMP6_DST_UNREACH_ADDR:
166 stat->icp6errs_dst_unreach_addr++;
167 return;
168 case ICMP6_DST_UNREACH_NOPORT:
169 stat->icp6errs_dst_unreach_noport++;
170 return;
171 }
172 break;
173 case ICMP6_PACKET_TOO_BIG:
174 stat->icp6errs_packet_too_big++;
175 return;
176 case ICMP6_TIME_EXCEEDED:
177 switch (code) {
178 case ICMP6_TIME_EXCEED_TRANSIT:
179 stat->icp6errs_time_exceed_transit++;
180 return;
181 case ICMP6_TIME_EXCEED_REASSEMBLY:
182 stat->icp6errs_time_exceed_reassembly++;
183 return;
184 }
185 break;
186 case ICMP6_PARAM_PROB:
187 switch (code) {
188 case ICMP6_PARAMPROB_HEADER:
189 stat->icp6errs_paramprob_header++;
190 return;
191 case ICMP6_PARAMPROB_NEXTHEADER:
192 stat->icp6errs_paramprob_nextheader++;
193 return;
194 case ICMP6_PARAMPROB_OPTION:
195 stat->icp6errs_paramprob_option++;
196 return;
197 }
198 break;
199 case ND_REDIRECT:
200 stat->icp6errs_redirect++;
201 return;
202 }
203 stat->icp6errs_unknown++;
204 }
205
206 /*
207 * Generate an error packet of type error in response to bad IP6 packet.
208 */
209 void
210 icmp6_error(m, type, code, param)
211 struct mbuf *m;
212 int type, code, param;
213 {
214 struct ip6_hdr *oip6, *nip6;
215 struct icmp6_hdr *icmp6;
216 u_int preplen;
217 int off;
218 int nxt;
219
220 icmp6stat.icp6s_error++;
221
222 /* count per-type-code statistics */
223 icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
224
225 #ifdef M_DECRYPTED /*not openbsd*/
226 if (m->m_flags & M_DECRYPTED) {
227 icmp6stat.icp6s_canterror++;
228 goto freeit;
229 }
230 #endif
231
232 #ifndef PULLDOWN_TEST
233 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
234 #else
235 if (m->m_len < sizeof(struct ip6_hdr)) {
236 m = m_pullup(m, sizeof(struct ip6_hdr));
237 if (m == NULL)
238 return;
239 }
240 #endif
241 oip6 = mtod(m, struct ip6_hdr *);
242
243 /*
244 * If the destination address of the erroneous packet is a multicast
245 * address, or the packet was sent using link-layer multicast,
246 * we should basically suppress sending an error (RFC 2463, Section
247 * 2.4).
248 * We have two exceptions (the item e.2 in that section):
249 * - the Pakcet Too Big message can be sent for path MTU discovery.
250 * - the Parameter Problem Message that can be allowed an icmp6 error
251 * in the option type field. This check has been done in
252 * ip6_unknown_opt(), so we can just check the type and code.
253 */
254 if ((m->m_flags & (M_BCAST|M_MCAST) ||
255 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
256 (type != ICMP6_PACKET_TOO_BIG &&
257 (type != ICMP6_PARAM_PROB ||
258 code != ICMP6_PARAMPROB_OPTION)))
259 goto freeit;
260
261 /*
262 * RFC 2463, 2.4 (e.5): source address check.
263 * XXX: the case of anycast source?
264 */
265 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
266 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
267 goto freeit;
268
269 /*
270 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
271 * don't do it.
272 */
273 nxt = -1;
274 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
275 if (off >= 0 && nxt == IPPROTO_ICMPV6) {
276 struct icmp6_hdr *icp;
277
278 #ifndef PULLDOWN_TEST
279 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
280 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
281 #else
282 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
283 sizeof(*icp));
284 if (icp == NULL) {
285 icmp6stat.icp6s_tooshort++;
286 return;
287 }
288 #endif
289 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
290 icp->icmp6_type == ND_REDIRECT) {
291 /*
292 * ICMPv6 error
293 * Special case: for redirect (which is
294 * informational) we must not send icmp6 error.
295 */
296 icmp6stat.icp6s_canterror++;
297 goto freeit;
298 } else {
299 /* ICMPv6 informational - send the error */
300 }
301 } else {
302 /* non-ICMPv6 - send the error */
303 }
304
305 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
306
307 /* Finally, do rate limitation check. */
308 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
309 icmp6stat.icp6s_toofreq++;
310 goto freeit;
311 }
312
313 /*
314 * OK, ICMP6 can be generated.
315 */
316
317 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
318 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
319
320 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
321 M_PREPEND(m, preplen, M_DONTWAIT);
322 if (m && m->m_len < preplen)
323 m = m_pullup(m, preplen);
324 if (m == NULL) {
325 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
326 return;
327 }
328
329 nip6 = mtod(m, struct ip6_hdr *);
330 nip6->ip6_src = oip6->ip6_src;
331 nip6->ip6_dst = oip6->ip6_dst;
332
333 in6_clearscope(&oip6->ip6_src);
334 in6_clearscope(&oip6->ip6_dst);
335
336 icmp6 = (struct icmp6_hdr *)(nip6 + 1);
337 icmp6->icmp6_type = type;
338 icmp6->icmp6_code = code;
339 icmp6->icmp6_pptr = htonl((u_int32_t)param);
340
341 /*
342 * icmp6_reflect() is designed to be in the input path.
343 * icmp6_error() can be called from both input and outut path,
344 * and if we are in output path rcvif could contain bogus value.
345 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
346 * information in ip header (nip6).
347 */
348 m->m_pkthdr.rcvif = NULL;
349
350 icmp6stat.icp6s_outhist[type]++;
351 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
352
353 return;
354
355 freeit:
356 /*
357 * If we can't tell wheter or not we can generate ICMP6, free it.
358 */
359 m_freem(m);
360 }
361
362 /*
363 * Process a received ICMP6 message.
364 */
365 int
366 icmp6_input(mp, offp, proto)
367 struct mbuf **mp;
368 int *offp, proto;
369 {
370 struct mbuf *m = *mp, *n;
371 struct ip6_hdr *ip6, *nip6;
372 struct icmp6_hdr *icmp6, *nicmp6;
373 int off = *offp;
374 int icmp6len = m->m_pkthdr.len - *offp;
375 int code, sum, noff;
376
377 #ifndef PULLDOWN_TEST
378 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
379 /* m might change if M_LOOP. So, call mtod after this */
380 #endif
381
382 /*
383 * Locate icmp6 structure in mbuf, and check
384 * that not corrupted and of at least minimum length
385 */
386
387 ip6 = mtod(m, struct ip6_hdr *);
388 if (icmp6len < sizeof(struct icmp6_hdr)) {
389 icmp6stat.icp6s_tooshort++;
390 goto freeit;
391 }
392
393 /*
394 * calculate the checksum
395 */
396 #ifndef PULLDOWN_TEST
397 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
398 #else
399 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
400 if (icmp6 == NULL) {
401 icmp6stat.icp6s_tooshort++;
402 return IPPROTO_DONE;
403 }
404 #endif
405 code = icmp6->icmp6_code;
406
407 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
408 nd6log((LOG_ERR,
409 "ICMP6 checksum error(%d|%x) %s\n",
410 icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
411 icmp6stat.icp6s_checksum++;
412 goto freeit;
413 }
414
415 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
416 /*
417 * Deliver very specific ICMP6 type only.
418 * This is important to deilver TOOBIG. Otherwise PMTUD
419 * will not work.
420 */
421 switch (icmp6->icmp6_type) {
422 case ICMP6_DST_UNREACH:
423 case ICMP6_PACKET_TOO_BIG:
424 case ICMP6_TIME_EXCEEDED:
425 break;
426 default:
427 goto freeit;
428 }
429 }
430
431 icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
432 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
433 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
434 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
435
436 switch (icmp6->icmp6_type) {
437 case ICMP6_DST_UNREACH:
438 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
439 switch (code) {
440 case ICMP6_DST_UNREACH_NOROUTE:
441 code = PRC_UNREACH_NET;
442 break;
443 case ICMP6_DST_UNREACH_ADMIN:
444 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
445 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
446 break;
447 case ICMP6_DST_UNREACH_ADDR:
448 code = PRC_HOSTDEAD;
449 break;
450 #ifdef COMPAT_RFC1885
451 case ICMP6_DST_UNREACH_NOTNEIGHBOR:
452 code = PRC_UNREACH_SRCFAIL;
453 break;
454 #else
455 case ICMP6_DST_UNREACH_BEYONDSCOPE:
456 /* I mean "source address was incorrect." */
457 code = PRC_PARAMPROB;
458 break;
459 #endif
460 case ICMP6_DST_UNREACH_NOPORT:
461 code = PRC_UNREACH_PORT;
462 break;
463 default:
464 goto badcode;
465 }
466 goto deliver;
467 break;
468
469 case ICMP6_PACKET_TOO_BIG:
470 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
471 if (code != 0)
472 goto badcode;
473
474 /* validation is made in icmp6_mtudisc_update */
475
476 code = PRC_MSGSIZE;
477
478 /*
479 * Updating the path MTU will be done after examining
480 * intermediate extension headers.
481 */
482 goto deliver;
483 break;
484
485 case ICMP6_TIME_EXCEEDED:
486 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
487 switch (code) {
488 case ICMP6_TIME_EXCEED_TRANSIT:
489 case ICMP6_TIME_EXCEED_REASSEMBLY:
490 code += PRC_TIMXCEED_INTRANS;
491 break;
492 default:
493 goto badcode;
494 }
495 goto deliver;
496 break;
497
498 case ICMP6_PARAM_PROB:
499 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
500 switch (code) {
501 case ICMP6_PARAMPROB_NEXTHEADER:
502 code = PRC_UNREACH_PROTOCOL;
503 break;
504 case ICMP6_PARAMPROB_HEADER:
505 case ICMP6_PARAMPROB_OPTION:
506 code = PRC_PARAMPROB;
507 break;
508 default:
509 goto badcode;
510 }
511 goto deliver;
512 break;
513
514 case ICMP6_ECHO_REQUEST:
515 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
516 if (code != 0)
517 goto badcode;
518 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
519 /* Give up remote */
520 break;
521 }
522 if ((n->m_flags & M_EXT) != 0
523 || n->m_len < off + sizeof(struct icmp6_hdr)) {
524 struct mbuf *n0 = n;
525 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
526 int n0len;
527
528 /*
529 * Prepare an internal mbuf. m_pullup() doesn't
530 * always copy the length we specified.
531 */
532 if (maxlen >= MCLBYTES) {
533 /* Give up remote */
534 m_freem(n0);
535 break;
536 }
537 MGETHDR(n, M_DONTWAIT, n0->m_type);
538 n0len = n0->m_pkthdr.len; /* save for use below */
539 if (n)
540 M_MOVE_PKTHDR(n, n0);
541 if (n && maxlen >= MHLEN) {
542 MCLGET(n, M_DONTWAIT);
543 if ((n->m_flags & M_EXT) == 0) {
544 m_free(n);
545 n = NULL;
546 }
547 }
548 if (n == NULL) {
549 /* Give up remote */
550 m_freem(n0);
551 break;
552 }
553 /*
554 * Copy IPv6 and ICMPv6 only.
555 */
556 nip6 = mtod(n, struct ip6_hdr *);
557 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
558 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
559 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
560 noff = sizeof(struct ip6_hdr);
561 /* new mbuf contains only ipv6+icmpv6 headers */
562 n->m_len = noff + sizeof(struct icmp6_hdr);
563 /*
564 * Adjust mbuf. ip6_plen will be adjusted in
565 * ip6_output().
566 */
567 m_adj(n0, off + sizeof(struct icmp6_hdr));
568 /* recalculate complete packet size */
569 n->m_pkthdr.len = n0len + (noff - off);
570 n->m_next = n0;
571 } else {
572 nip6 = mtod(n, struct ip6_hdr *);
573 nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
574 noff = off;
575 }
576 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
577 nicmp6->icmp6_code = 0;
578 if (n) {
579 icmp6stat.icp6s_reflect++;
580 icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
581 icmp6_reflect(n, noff);
582 }
583 break;
584
585 case ICMP6_ECHO_REPLY:
586 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
587 if (code != 0)
588 goto badcode;
589 break;
590
591 case MLD_LISTENER_QUERY:
592 case MLD_LISTENER_REPORT:
593 if (icmp6len < sizeof(struct mld_hdr))
594 goto badlen;
595 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
596 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
597 else
598 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
599 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
600 /* give up local */
601 mld6_input(m, off);
602 m = NULL;
603 goto freeit;
604 }
605 mld6_input(n, off);
606 /* m stays. */
607 break;
608
609 case MLD_LISTENER_DONE:
610 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
611 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */
612 goto badlen;
613 break; /* nothing to be done in kernel */
614
615 case MLD_MTRACE_RESP:
616 case MLD_MTRACE:
617 /* XXX: these two are experimental. not officially defined. */
618 /* XXX: per-interface statistics? */
619 break; /* just pass it to applications */
620
621 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
622 {
623 enum { WRU, FQDN } mode;
624
625 if (!icmp6_nodeinfo)
626 break;
627
628 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
629 mode = WRU;
630 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
631 mode = FQDN;
632 else
633 goto badlen;
634
635 #define hostnamelen strlen(hostname)
636 if (mode == FQDN) {
637 #ifndef PULLDOWN_TEST
638 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
639 IPPROTO_DONE);
640 #endif
641 n = m_copy(m, 0, M_COPYALL);
642 if (n)
643 n = ni6_input(n, off);
644 /* XXX meaningless if n == NULL */
645 noff = sizeof(struct ip6_hdr);
646 } else {
647 u_char *p;
648 int maxlen, maxhlen;
649
650 if ((icmp6_nodeinfo & 5) != 5)
651 break;
652
653 if (code != 0)
654 goto badcode;
655 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
656 if (maxlen >= MCLBYTES) {
657 /* Give up remote */
658 break;
659 }
660 MGETHDR(n, M_DONTWAIT, m->m_type);
661 if (n && maxlen > MHLEN) {
662 MCLGET(n, M_DONTWAIT);
663 if ((n->m_flags & M_EXT) == 0) {
664 m_free(n);
665 n = NULL;
666 }
667 }
668 if (!m_dup_pkthdr(n, m, M_DONTWAIT)) {
669 /*
670 * Previous code did a blind M_COPY_PKTHDR
671 * and said "just for rcvif". If true, then
672 * we could tolerate the dup failing (due to
673 * the deep copy of the tag chain). For now
674 * be conservative and just fail.
675 */
676 m_free(n);
677 n = NULL;
678 }
679 if (n == NULL) {
680 /* Give up remote */
681 break;
682 }
683 n->m_pkthdr.rcvif = NULL;
684 n->m_len = 0;
685 maxhlen = M_TRAILINGSPACE(n) - maxlen;
686 if (maxhlen > hostnamelen)
687 maxhlen = hostnamelen;
688 /*
689 * Copy IPv6 and ICMPv6 only.
690 */
691 nip6 = mtod(n, struct ip6_hdr *);
692 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
693 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
694 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
695 p = (u_char *)(nicmp6 + 1);
696 bzero(p, 4);
697 bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
698 noff = sizeof(struct ip6_hdr);
699 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
700 sizeof(struct icmp6_hdr) + 4 + maxhlen;
701 nicmp6->icmp6_type = ICMP6_WRUREPLY;
702 nicmp6->icmp6_code = 0;
703 }
704 #undef hostnamelen
705 if (n) {
706 icmp6stat.icp6s_reflect++;
707 icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
708 icmp6_reflect(n, noff);
709 }
710 break;
711 }
712
713 case ICMP6_WRUREPLY:
714 if (code != 0)
715 goto badcode;
716 break;
717
718 case ND_ROUTER_SOLICIT:
719 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
720 if (code != 0)
721 goto badcode;
722 if (icmp6len < sizeof(struct nd_router_solicit))
723 goto badlen;
724 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
725 /* give up local */
726 nd6_rs_input(m, off, icmp6len);
727 m = NULL;
728 goto freeit;
729 }
730 nd6_rs_input(n, off, icmp6len);
731 /* m stays. */
732 break;
733
734 case ND_ROUTER_ADVERT:
735 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
736 if (code != 0)
737 goto badcode;
738 if (icmp6len < sizeof(struct nd_router_advert))
739 goto badlen;
740 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
741 /* give up local */
742 nd6_ra_input(m, off, icmp6len);
743 m = NULL;
744 goto freeit;
745 }
746 nd6_ra_input(n, off, icmp6len);
747 /* m stays. */
748 break;
749
750 case ND_NEIGHBOR_SOLICIT:
751 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
752 if (code != 0)
753 goto badcode;
754 if (icmp6len < sizeof(struct nd_neighbor_solicit))
755 goto badlen;
756 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
757 /* give up local */
758 nd6_ns_input(m, off, icmp6len);
759 m = NULL;
760 goto freeit;
761 }
762 nd6_ns_input(n, off, icmp6len);
763 /* m stays. */
764 break;
765
766 case ND_NEIGHBOR_ADVERT:
767 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
768 if (code != 0)
769 goto badcode;
770 if (icmp6len < sizeof(struct nd_neighbor_advert))
771 goto badlen;
772 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
773 /* give up local */
774 nd6_na_input(m, off, icmp6len);
775 m = NULL;
776 goto freeit;
777 }
778 nd6_na_input(n, off, icmp6len);
779 /* m stays. */
780 break;
781
782 case ND_REDIRECT:
783 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
784 if (code != 0)
785 goto badcode;
786 if (icmp6len < sizeof(struct nd_redirect))
787 goto badlen;
788 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
789 /* give up local */
790 icmp6_redirect_input(m, off);
791 m = NULL;
792 goto freeit;
793 }
794 icmp6_redirect_input(n, off);
795 /* m stays. */
796 break;
797
798 case ICMP6_ROUTER_RENUMBERING:
799 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
800 code != ICMP6_ROUTER_RENUMBERING_RESULT)
801 goto badcode;
802 if (icmp6len < sizeof(struct icmp6_router_renum))
803 goto badlen;
804 break;
805
806 default:
807 nd6log((LOG_DEBUG,
808 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
809 icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
810 ip6_sprintf(&ip6->ip6_dst),
811 m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
812 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
813 /* ICMPv6 error: MUST deliver it by spec... */
814 code = PRC_NCMDS;
815 /* deliver */
816 } else {
817 /* ICMPv6 informational: MUST not deliver */
818 break;
819 }
820 deliver:
821 if (icmp6_notify_error(m, off, icmp6len, code)) {
822 /* In this case, m should've been freed. */
823 return (IPPROTO_DONE);
824 }
825 break;
826
827 badcode:
828 icmp6stat.icp6s_badcode++;
829 break;
830
831 badlen:
832 icmp6stat.icp6s_badlen++;
833 break;
834 }
835
836 /* deliver the packet to appropriate sockets */
837 icmp6_rip6_input(&m, *offp);
838
839 return IPPROTO_DONE;
840
841 freeit:
842 m_freem(m);
843 return IPPROTO_DONE;
844 }
845
846 static int
847 icmp6_notify_error(m, off, icmp6len, code)
848 struct mbuf *m;
849 int off, icmp6len, code;
850 {
851 struct icmp6_hdr *icmp6;
852 struct ip6_hdr *eip6;
853 u_int32_t notifymtu;
854 struct sockaddr_in6 icmp6src, icmp6dst;
855
856 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
857 icmp6stat.icp6s_tooshort++;
858 goto freeit;
859 }
860 #ifndef PULLDOWN_TEST
861 IP6_EXTHDR_CHECK(m, off,
862 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
863 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
864 #else
865 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
866 sizeof(*icmp6) + sizeof(struct ip6_hdr));
867 if (icmp6 == NULL) {
868 icmp6stat.icp6s_tooshort++;
869 return (-1);
870 }
871 #endif
872 eip6 = (struct ip6_hdr *)(icmp6 + 1);
873
874 /* Detect the upper level protocol */
875 {
876 void (*ctlfunc) __P((int, struct sockaddr *, void *));
877 u_int8_t nxt = eip6->ip6_nxt;
878 int eoff = off + sizeof(struct icmp6_hdr) +
879 sizeof(struct ip6_hdr);
880 struct ip6ctlparam ip6cp;
881 struct in6_addr *finaldst = NULL;
882 int icmp6type = icmp6->icmp6_type;
883 struct ip6_frag *fh;
884 struct ip6_rthdr *rth;
885 struct ip6_rthdr0 *rth0;
886 int rthlen;
887
888 while (1) { /* XXX: should avoid infinite loop explicitly? */
889 struct ip6_ext *eh;
890
891 switch (nxt) {
892 case IPPROTO_HOPOPTS:
893 case IPPROTO_DSTOPTS:
894 case IPPROTO_AH:
895 #ifndef PULLDOWN_TEST
896 IP6_EXTHDR_CHECK(m, 0,
897 eoff + sizeof(struct ip6_ext), -1);
898 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
899 #else
900 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
901 eoff, sizeof(*eh));
902 if (eh == NULL) {
903 icmp6stat.icp6s_tooshort++;
904 return (-1);
905 }
906 #endif
907
908 if (nxt == IPPROTO_AH)
909 eoff += (eh->ip6e_len + 2) << 2;
910 else
911 eoff += (eh->ip6e_len + 1) << 3;
912 nxt = eh->ip6e_nxt;
913 break;
914 case IPPROTO_ROUTING:
915 /*
916 * When the erroneous packet contains a
917 * routing header, we should examine the
918 * header to determine the final destination.
919 * Otherwise, we can't properly update
920 * information that depends on the final
921 * destination (e.g. path MTU).
922 */
923 #ifndef PULLDOWN_TEST
924 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
925 rth = (struct ip6_rthdr *)
926 (mtod(m, caddr_t) + eoff);
927 #else
928 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
929 eoff, sizeof(*rth));
930 if (rth == NULL) {
931 icmp6stat.icp6s_tooshort++;
932 return (-1);
933 }
934 #endif
935 rthlen = (rth->ip6r_len + 1) << 3;
936 /*
937 * XXX: currently there is no
938 * officially defined type other
939 * than type-0.
940 * Note that if the segment left field
941 * is 0, all intermediate hops must
942 * have been passed.
943 */
944 if (rth->ip6r_segleft &&
945 rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
946 int hops;
947
948 #ifndef PULLDOWN_TEST
949 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
950 rth0 = (struct ip6_rthdr0 *)
951 (mtod(m, caddr_t) + eoff);
952 #else
953 IP6_EXTHDR_GET(rth0,
954 struct ip6_rthdr0 *, m,
955 eoff, rthlen);
956 if (rth0 == NULL) {
957 icmp6stat.icp6s_tooshort++;
958 return (-1);
959 }
960 #endif
961 /* just ignore a bogus header */
962 if ((rth0->ip6r0_len % 2) == 0 &&
963 (hops = rth0->ip6r0_len/2))
964 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
965 }
966 eoff += rthlen;
967 nxt = rth->ip6r_nxt;
968 break;
969 case IPPROTO_FRAGMENT:
970 #ifndef PULLDOWN_TEST
971 IP6_EXTHDR_CHECK(m, 0, eoff +
972 sizeof(struct ip6_frag), -1);
973 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
974 eoff);
975 #else
976 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
977 eoff, sizeof(*fh));
978 if (fh == NULL) {
979 icmp6stat.icp6s_tooshort++;
980 return (-1);
981 }
982 #endif
983 /*
984 * Data after a fragment header is meaningless
985 * unless it is the first fragment, but
986 * we'll go to the notify label for path MTU
987 * discovery.
988 */
989 if (fh->ip6f_offlg & IP6F_OFF_MASK)
990 goto notify;
991
992 eoff += sizeof(struct ip6_frag);
993 nxt = fh->ip6f_nxt;
994 break;
995 default:
996 /*
997 * This case includes ESP and the No Next
998 * Header. In such cases going to the notify
999 * label does not have any meaning
1000 * (i.e. ctlfunc will be NULL), but we go
1001 * anyway since we might have to update
1002 * path MTU information.
1003 */
1004 goto notify;
1005 }
1006 }
1007 notify:
1008 #ifndef PULLDOWN_TEST
1009 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1010 #else
1011 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1012 sizeof(*icmp6) + sizeof(struct ip6_hdr));
1013 if (icmp6 == NULL) {
1014 icmp6stat.icp6s_tooshort++;
1015 return (-1);
1016 }
1017 #endif
1018
1019 /*
1020 * retrieve parameters from the inner IPv6 header, and convert
1021 * them into sockaddr structures.
1022 * XXX: there is no guarantee that the source or destination
1023 * addresses of the inner packet are in the same scope as
1024 * the addresses of the icmp packet. But there is no other
1025 * way to determine the zone.
1026 */
1027 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1028
1029 bzero(&icmp6dst, sizeof(icmp6dst));
1030 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1031 icmp6dst.sin6_family = AF_INET6;
1032 if (finaldst == NULL)
1033 icmp6dst.sin6_addr = eip6->ip6_dst;
1034 else
1035 icmp6dst.sin6_addr = *finaldst;
1036 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6dst.sin6_addr,
1037 &icmp6dst.sin6_scope_id))
1038 goto freeit;
1039 if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
1040 NULL, NULL)) {
1041 /* should be impossbile */
1042 nd6log((LOG_DEBUG,
1043 "icmp6_notify_error: in6_embedscope failed\n"));
1044 goto freeit;
1045 }
1046
1047 /*
1048 * retrieve parameters from the inner IPv6 header, and convert
1049 * them into sockaddr structures.
1050 */
1051 bzero(&icmp6src, sizeof(icmp6src));
1052 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1053 icmp6src.sin6_family = AF_INET6;
1054 icmp6src.sin6_addr = eip6->ip6_src;
1055 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6src.sin6_addr,
1056 &icmp6src.sin6_scope_id)) {
1057 goto freeit;
1058 }
1059 if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
1060 NULL, NULL)) {
1061 /* should be impossbile */
1062 nd6log((LOG_DEBUG,
1063 "icmp6_notify_error: in6_embedscope failed\n"));
1064 goto freeit;
1065 }
1066 icmp6src.sin6_flowinfo = (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1067
1068 if (finaldst == NULL)
1069 finaldst = &eip6->ip6_dst;
1070 ip6cp.ip6c_m = m;
1071 ip6cp.ip6c_icmp6 = icmp6;
1072 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1073 ip6cp.ip6c_off = eoff;
1074 ip6cp.ip6c_finaldst = finaldst;
1075 ip6cp.ip6c_src = &icmp6src;
1076 ip6cp.ip6c_nxt = nxt;
1077
1078 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1079 notifymtu = ntohl(icmp6->icmp6_mtu);
1080 ip6cp.ip6c_cmdarg = (void *)¬ifymtu;
1081 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
1082 }
1083
1084 ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
1085 (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1086 if (ctlfunc) {
1087 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1088 &ip6cp);
1089 }
1090 }
1091 return (0);
1092
1093 freeit:
1094 m_freem(m);
1095 return (-1);
1096 }
1097
1098 void
1099 icmp6_mtudisc_update(ip6cp, validated)
1100 struct ip6ctlparam *ip6cp;
1101 int validated;
1102 {
1103 struct in6_addr *dst = ip6cp->ip6c_finaldst;
1104 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1105 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1106 u_int mtu = ntohl(icmp6->icmp6_mtu);
1107 struct in_conninfo inc;
1108
1109 #if 0
1110 /*
1111 * RFC2460 section 5, last paragraph.
1112 * even though minimum link MTU for IPv6 is IPV6_MMTU,
1113 * we may see ICMPv6 too big with mtu < IPV6_MMTU
1114 * due to packet translator in the middle.
1115 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1116 * special handling.
1117 */
1118 if (mtu < IPV6_MMTU)
1119 return;
1120 #endif
1121
1122 /*
1123 * we reject ICMPv6 too big with abnormally small value.
1124 * XXX what is the good definition of "abnormally small"?
1125 */
1126 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1127 return;
1128
1129 if (!validated)
1130 return;
1131
1132 bzero(&inc, sizeof(inc));
1133 inc.inc_flags = 1; /* IPv6 */
1134 inc.inc6_faddr = *dst;
1135 /* XXX normally, this won't happen */
1136 if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1137 inc.inc6_faddr.s6_addr16[1] =
1138 htons(m->m_pkthdr.rcvif->if_index);
1139 }
1140
1141 if (mtu < tcp_maxmtu6(&inc)) {
1142 tcp_hc_updatemtu(&inc, mtu);
1143 icmp6stat.icp6s_pmtuchg++;
1144 }
1145 }
1146
1147 /*
1148 * Process a Node Information Query packet, based on
1149 * draft-ietf-ipngwg-icmp-name-lookups-07.
1150 *
1151 * Spec incompatibilities:
1152 * - IPv6 Subject address handling
1153 * - IPv4 Subject address handling support missing
1154 * - Proxy reply (answer even if it's not for me)
1155 * - joins NI group address at in6_ifattach() time only, does not cope
1156 * with hostname changes by sethostname(3)
1157 */
1158 #define hostnamelen strlen(hostname)
1159 static struct mbuf *
1160 ni6_input(m, off)
1161 struct mbuf *m;
1162 int off;
1163 {
1164 struct icmp6_nodeinfo *ni6, *nni6;
1165 struct mbuf *n = NULL;
1166 u_int16_t qtype;
1167 int subjlen;
1168 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1169 struct ni_reply_fqdn *fqdn;
1170 int addrs; /* for NI_QTYPE_NODEADDR */
1171 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1172 struct sockaddr_in6 sin6_sbj; /* subject address */
1173 struct sockaddr_in6 sin6_d;
1174 struct ip6_hdr *ip6;
1175 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
1176 char *subj = NULL;
1177 struct in6_ifaddr *ia6 = NULL;
1178
1179 ip6 = mtod(m, struct ip6_hdr *);
1180 #ifndef PULLDOWN_TEST
1181 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1182 #else
1183 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1184 if (ni6 == NULL) {
1185 /* m is already reclaimed */
1186 return (NULL);
1187 }
1188 #endif
1189
1190 bzero(&sin6_d, sizeof(sin6_d));
1191 sin6_d.sin6_family = AF_INET6; /* not used, actually */
1192 sin6_d.sin6_len = sizeof(sin6_d); /* ditto */
1193 sin6_d.sin6_addr = ip6->ip6_dst;
1194 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_dst,
1195 &sin6_d.sin6_scope_id)) {
1196 goto bad;
1197 }
1198 if (in6_embedscope(&sin6_d.sin6_addr, &sin6_d, NULL, NULL))
1199 goto bad; /* XXX should not happen */
1200
1201 /*
1202 * Validate IPv6 destination address.
1203 *
1204 * The Responder must discard the Query without further processing
1205 * unless it is one of the Responder's unicast or anycast addresses, or
1206 * a link-local scope multicast address which the Responder has joined.
1207 * [icmp-name-lookups-08, Section 4.]
1208 */
1209 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1210 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1211 goto bad;
1212 /* else it's a link-local multicast, fine */
1213 } else { /* unicast or anycast */
1214 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1215 goto bad; /* XXX impossible */
1216
1217 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1218 !(icmp6_nodeinfo & 4)) {
1219 nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1220 "a temporary address in %s:%d",
1221 __FILE__, __LINE__));
1222 goto bad;
1223 }
1224 }
1225
1226 /* validate query Subject field. */
1227 qtype = ntohs(ni6->ni_qtype);
1228 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1229 switch (qtype) {
1230 case NI_QTYPE_NOOP:
1231 case NI_QTYPE_SUPTYPES:
1232 /* 07 draft */
1233 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1234 break;
1235 /* FALLTHROUGH */
1236 case NI_QTYPE_FQDN:
1237 case NI_QTYPE_NODEADDR:
1238 switch (ni6->ni_code) {
1239 case ICMP6_NI_SUBJ_IPV6:
1240 #if ICMP6_NI_SUBJ_IPV6 != 0
1241 case 0:
1242 #endif
1243 /*
1244 * backward compatibility - try to accept 03 draft
1245 * format, where no Subject is present.
1246 */
1247 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1248 subjlen == 0) {
1249 oldfqdn++;
1250 break;
1251 }
1252 #if ICMP6_NI_SUBJ_IPV6 != 0
1253 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1254 goto bad;
1255 #endif
1256
1257 if (subjlen != sizeof(struct in6_addr))
1258 goto bad;
1259
1260 /*
1261 * Validate Subject address.
1262 *
1263 * Not sure what exactly "address belongs to the node"
1264 * means in the spec, is it just unicast, or what?
1265 *
1266 * At this moment we consider Subject address as
1267 * "belong to the node" if the Subject address equals
1268 * to the IPv6 destination address; validation for
1269 * IPv6 destination address should have done enough
1270 * check for us.
1271 *
1272 * We do not do proxy at this moment.
1273 */
1274 /* m_pulldown instead of copy? */
1275 bzero(&sin6_sbj, sizeof(sin6_sbj));
1276 sin6_sbj.sin6_family = AF_INET6;
1277 sin6_sbj.sin6_len = sizeof(sin6_sbj);
1278 m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1279 subjlen, (caddr_t)&sin6_sbj.sin6_addr);
1280 if (in6_addr2zoneid(m->m_pkthdr.rcvif,
1281 &sin6_sbj.sin6_addr, &sin6_sbj.sin6_scope_id)) {
1282 goto bad;
1283 }
1284 if (in6_embedscope(&sin6_sbj.sin6_addr, &sin6_sbj,
1285 NULL, NULL))
1286 goto bad; /* XXX should not happen */
1287
1288 subj = (char *)&sin6_sbj;
1289 if (SA6_ARE_ADDR_EQUAL(&sin6_sbj, &sin6_d))
1290 break;
1291
1292 /*
1293 * XXX if we are to allow other cases, we should really
1294 * be careful about scope here.
1295 * basically, we should disallow queries toward IPv6
1296 * destination X with subject Y,
1297 * if scope(X) > scope(Y).
1298 * if we allow scope(X) > scope(Y), it will result in
1299 * information leakage across scope boundary.
1300 */
1301 goto bad;
1302
1303 case ICMP6_NI_SUBJ_FQDN:
1304 /*
1305 * Validate Subject name with gethostname(3).
1306 *
1307 * The behavior may need some debate, since:
1308 * - we are not sure if the node has FQDN as
1309 * hostname (returned by gethostname(3)).
1310 * - the code does wildcard match for truncated names.
1311 * however, we are not sure if we want to perform
1312 * wildcard match, if gethostname(3) side has
1313 * truncated hostname.
1314 */
1315 n = ni6_nametodns(hostname, hostnamelen, 0);
1316 if (!n || n->m_next || n->m_len == 0)
1317 goto bad;
1318 IP6_EXTHDR_GET(subj, char *, m,
1319 off + sizeof(struct icmp6_nodeinfo), subjlen);
1320 if (subj == NULL)
1321 goto bad;
1322 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1323 n->m_len)) {
1324 goto bad;
1325 }
1326 m_freem(n);
1327 n = NULL;
1328 break;
1329
1330 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
1331 default:
1332 goto bad;
1333 }
1334 break;
1335 }
1336
1337 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
1338 switch (qtype) {
1339 case NI_QTYPE_FQDN:
1340 if ((icmp6_nodeinfo & 1) == 0)
1341 goto bad;
1342 break;
1343 case NI_QTYPE_NODEADDR:
1344 if ((icmp6_nodeinfo & 2) == 0)
1345 goto bad;
1346 break;
1347 }
1348
1349 /* guess reply length */
1350 switch (qtype) {
1351 case NI_QTYPE_NOOP:
1352 break; /* no reply data */
1353 case NI_QTYPE_SUPTYPES:
1354 replylen += sizeof(u_int32_t);
1355 break;
1356 case NI_QTYPE_FQDN:
1357 /* XXX will append an mbuf */
1358 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1359 break;
1360 case NI_QTYPE_NODEADDR:
1361 addrs = ni6_addrs(ni6, m, &ifp, subj);
1362 if ((replylen += addrs * (sizeof(struct in6_addr) +
1363 sizeof(u_int32_t))) > MCLBYTES)
1364 replylen = MCLBYTES; /* XXX: will truncate pkt later */
1365 break;
1366 default:
1367 /*
1368 * XXX: We must return a reply with the ICMP6 code
1369 * `unknown Qtype' in this case. However we regard the case
1370 * as an FQDN query for backward compatibility.
1371 * Older versions set a random value to this field,
1372 * so it rarely varies in the defined qtypes.
1373 * But the mechanism is not reliable...
1374 * maybe we should obsolete older versions.
1375 */
1376 qtype = NI_QTYPE_FQDN;
1377 /* XXX will append an mbuf */
1378 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1379 oldfqdn++;
1380 break;
1381 }
1382
1383 /* allocate an mbuf to reply. */
1384 MGETHDR(n, M_DONTWAIT, m->m_type);
1385 if (n == NULL) {
1386 m_freem(m);
1387 return (NULL);
1388 }
1389 M_MOVE_PKTHDR(n, m); /* just for recvif */
1390 if (replylen > MHLEN) {
1391 if (replylen > MCLBYTES) {
1392 /*
1393 * XXX: should we try to allocate more? But MCLBYTES
1394 * is probably much larger than IPV6_MMTU...
1395 */
1396 goto bad;
1397 }
1398 MCLGET(n, M_DONTWAIT);
1399 if ((n->m_flags & M_EXT) == 0) {
1400 goto bad;
1401 }
1402 }
1403 n->m_pkthdr.len = n->m_len = replylen;
1404
1405 /* copy mbuf header and IPv6 + Node Information base headers */
1406 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1407 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1408 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1409
1410 /* qtype dependent procedure */
1411 switch (qtype) {
1412 case NI_QTYPE_NOOP:
1413 nni6->ni_code = ICMP6_NI_SUCCESS;
1414 nni6->ni_flags = 0;
1415 break;
1416 case NI_QTYPE_SUPTYPES:
1417 {
1418 u_int32_t v;
1419 nni6->ni_code = ICMP6_NI_SUCCESS;
1420 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1421 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1422 v = (u_int32_t)htonl(0x0000000f);
1423 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1424 break;
1425 }
1426 case NI_QTYPE_FQDN:
1427 nni6->ni_code = ICMP6_NI_SUCCESS;
1428 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1429 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1430 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1431 fqdn->ni_fqdn_ttl = 0; /* ditto. */
1432 /*
1433 * XXX do we really have FQDN in variable "hostname"?
1434 */
1435 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1436 if (n->m_next == NULL)
1437 goto bad;
1438 /* XXX we assume that n->m_next is not a chain */
1439 if (n->m_next->m_next != NULL)
1440 goto bad;
1441 n->m_pkthdr.len += n->m_next->m_len;
1442 break;
1443 case NI_QTYPE_NODEADDR:
1444 {
1445 int lenlim, copied;
1446
1447 nni6->ni_code = ICMP6_NI_SUCCESS;
1448 n->m_pkthdr.len = n->m_len =
1449 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1450 lenlim = M_TRAILINGSPACE(n);
1451 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1452 /* XXX: reset mbuf length */
1453 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1454 sizeof(struct icmp6_nodeinfo) + copied;
1455 break;
1456 }
1457 default:
1458 break; /* XXX impossible! */
1459 }
1460
1461 nni6->ni_type = ICMP6_NI_REPLY;
1462 m_freem(m);
1463 return (n);
1464
1465 bad:
1466 m_freem(m);
1467 if (n)
1468 m_freem(n);
1469 return (NULL);
1470 }
1471 #undef hostnamelen
1472
1473 /*
1474 * make a mbuf with DNS-encoded string. no compression support.
1475 *
1476 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1477 * treated as truncated name (two \0 at the end). this is a wild guess.
1478 */
1479 static struct mbuf *
1480 ni6_nametodns(name, namelen, old)
1481 const char *name;
1482 int namelen;
1483 int old; /* return pascal string if non-zero */
1484 {
1485 struct mbuf *m;
1486 char *cp, *ep;
1487 const char *p, *q;
1488 int i, len, nterm;
1489
1490 if (old)
1491 len = namelen + 1;
1492 else
1493 len = MCLBYTES;
1494
1495 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1496 MGET(m, M_DONTWAIT, MT_DATA);
1497 if (m && len > MLEN) {
1498 MCLGET(m, M_DONTWAIT);
1499 if ((m->m_flags & M_EXT) == 0)
1500 goto fail;
1501 }
1502 if (!m)
1503 goto fail;
1504 m->m_next = NULL;
1505
1506 if (old) {
1507 m->m_len = len;
1508 *mtod(m, char *) = namelen;
1509 bcopy(name, mtod(m, char *) + 1, namelen);
1510 return m;
1511 } else {
1512 m->m_len = 0;
1513 cp = mtod(m, char *);
1514 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1515
1516 /* if not certain about my name, return empty buffer */
1517 if (namelen == 0)
1518 return m;
1519
1520 /*
1521 * guess if it looks like shortened hostname, or FQDN.
1522 * shortened hostname needs two trailing "\0".
1523 */
1524 i = 0;
1525 for (p = name; p < name + namelen; p++) {
1526 if (*p && *p == '.')
1527 i++;
1528 }
1529 if (i < 2)
1530 nterm = 2;
1531 else
1532 nterm = 1;
1533
1534 p = name;
1535 while (cp < ep && p < name + namelen) {
1536 i = 0;
1537 for (q = p; q < name + namelen && *q && *q != '.'; q++)
1538 i++;
1539 /* result does not fit into mbuf */
1540 if (cp + i + 1 >= ep)
1541 goto fail;
1542 /*
1543 * DNS label length restriction, RFC1035 page 8.
1544 * "i == 0" case is included here to avoid returning
1545 * 0-length label on "foo..bar".
1546 */
1547 if (i <= 0 || i >= 64)
1548 goto fail;
1549 *cp++ = i;
1550 bcopy(p, cp, i);
1551 cp += i;
1552 p = q;
1553 if (p < name + namelen && *p == '.')
1554 p++;
1555 }
1556 /* termination */
1557 if (cp + nterm >= ep)
1558 goto fail;
1559 while (nterm-- > 0)
1560 *cp++ = '\0';
1561 m->m_len = cp - mtod(m, char *);
1562 return m;
1563 }
1564
1565 panic("should not reach here");
1566 /* NOTREACHED */
1567
1568 fail:
1569 if (m)
1570 m_freem(m);
1571 return NULL;
1572 }
1573
1574 /*
1575 * check if two DNS-encoded string matches. takes care of truncated
1576 * form (with \0\0 at the end). no compression support.
1577 * XXX upper/lowercase match (see RFC2065)
1578 */
1579 static int
1580 ni6_dnsmatch(a, alen, b, blen)
1581 const char *a;
1582 int alen;
1583 const char *b;
1584 int blen;
1585 {
1586 const char *a0, *b0;
1587 int l;
1588
1589 /* simplest case - need validation? */
1590 if (alen == blen && bcmp(a, b, alen) == 0)
1591 return 1;
1592
1593 a0 = a;
1594 b0 = b;
1595
1596 /* termination is mandatory */
1597 if (alen < 2 || blen < 2)
1598 return 0;
1599 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1600 return 0;
1601 alen--;
1602 blen--;
1603
1604 while (a - a0 < alen && b - b0 < blen) {
1605 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1606 return 0;
1607
1608 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1609 return 0;
1610 /* we don't support compression yet */
1611 if (a[0] >= 64 || b[0] >= 64)
1612 return 0;
1613
1614 /* truncated case */
1615 if (a[0] == 0 && a - a0 == alen - 1)
1616 return 1;
1617 if (b[0] == 0 && b - b0 == blen - 1)
1618 return 1;
1619 if (a[0] == 0 || b[0] == 0)
1620 return 0;
1621
1622 if (a[0] != b[0])
1623 return 0;
1624 l = a[0];
1625 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1626 return 0;
1627 if (bcmp(a + 1, b + 1, l) != 0)
1628 return 0;
1629
1630 a += 1 + l;
1631 b += 1 + l;
1632 }
1633
1634 if (a - a0 == alen && b - b0 == blen)
1635 return 1;
1636 else
1637 return 0;
1638 }
1639
1640 /*
1641 * calculate the number of addresses to be returned in the node info reply.
1642 */
1643 static int
1644 ni6_addrs(ni6, m, ifpp, subj)
1645 struct icmp6_nodeinfo *ni6;
1646 struct mbuf *m;
1647 struct ifnet **ifpp;
1648 char *subj;
1649 {
1650 struct ifnet *ifp;
1651 struct in6_ifaddr *ifa6;
1652 struct ifaddr *ifa;
1653 struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1654 int addrs = 0, addrsofif, iffound = 0;
1655 int niflags = ni6->ni_flags;
1656
1657 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1658 switch (ni6->ni_code) {
1659 case ICMP6_NI_SUBJ_IPV6:
1660 if (subj == NULL) /* must be impossible... */
1661 return (0);
1662 subj_ip6 = (struct sockaddr_in6 *)subj;
1663 break;
1664 default:
1665 /*
1666 * XXX: we only support IPv6 subject address for
1667 * this Qtype.
1668 */
1669 return (0);
1670 }
1671 }
1672
1673 IFNET_RLOCK();
1674 for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1675 addrsofif = 0;
1676 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1677 if (ifa->ifa_addr->sa_family != AF_INET6)
1678 continue;
1679 ifa6 = (struct in6_ifaddr *)ifa;
1680
1681 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1682 IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1683 &ifa6->ia_addr.sin6_addr))
1684 iffound = 1;
1685
1686 /*
1687 * IPv4-mapped addresses can only be returned by a
1688 * Node Information proxy, since they represent
1689 * addresses of IPv4-only nodes, which perforce do
1690 * not implement this protocol.
1691 * [icmp-name-lookups-07, Section 5.4]
1692 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1693 * this function at this moment.
1694 */
1695
1696 /* What do we have to do about ::1? */
1697 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1698 case IPV6_ADDR_SCOPE_LINKLOCAL:
1699 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1700 continue;
1701 break;
1702 case IPV6_ADDR_SCOPE_SITELOCAL:
1703 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1704 continue;
1705 break;
1706 case IPV6_ADDR_SCOPE_GLOBAL:
1707 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1708 continue;
1709 break;
1710 default:
1711 continue;
1712 }
1713
1714 /*
1715 * check if anycast is okay.
1716 * XXX: just experimental. not in the spec.
1717 */
1718 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1719 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1720 continue; /* we need only unicast addresses */
1721 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1722 (icmp6_nodeinfo & 4) == 0) {
1723 continue;
1724 }
1725 addrsofif++; /* count the address */
1726 }
1727 if (iffound) {
1728 *ifpp = ifp;
1729 IFNET_RUNLOCK();
1730 return (addrsofif);
1731 }
1732
1733 addrs += addrsofif;
1734 }
1735 IFNET_RUNLOCK();
1736
1737 return (addrs);
1738 }
1739
1740 static int
1741 ni6_store_addrs(ni6, nni6, ifp0, resid)
1742 struct icmp6_nodeinfo *ni6, *nni6;
1743 struct ifnet *ifp0;
1744 int resid;
1745 {
1746 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1747 struct in6_ifaddr *ifa6;
1748 struct ifaddr *ifa;
1749 struct ifnet *ifp_dep = NULL;
1750 int copied = 0, allow_deprecated = 0;
1751 u_char *cp = (u_char *)(nni6 + 1);
1752 int niflags = ni6->ni_flags;
1753 u_int32_t ltime;
1754
1755 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1756 return (0); /* needless to copy */
1757
1758 IFNET_RLOCK();
1759 again:
1760
1761 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1762 for (ifa = ifp->if_addrlist.tqh_first; ifa;
1763 ifa = ifa->ifa_list.tqe_next) {
1764 if (ifa->ifa_addr->sa_family != AF_INET6)
1765 continue;
1766 ifa6 = (struct in6_ifaddr *)ifa;
1767
1768 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1769 allow_deprecated == 0) {
1770 /*
1771 * prefererred address should be put before
1772 * deprecated addresses.
1773 */
1774
1775 /* record the interface for later search */
1776 if (ifp_dep == NULL)
1777 ifp_dep = ifp;
1778
1779 continue;
1780 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1781 allow_deprecated != 0)
1782 continue; /* we now collect deprecated addrs */
1783
1784 /* What do we have to do about ::1? */
1785 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1786 case IPV6_ADDR_SCOPE_LINKLOCAL:
1787 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1788 continue;
1789 break;
1790 case IPV6_ADDR_SCOPE_SITELOCAL:
1791 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1792 continue;
1793 break;
1794 case IPV6_ADDR_SCOPE_GLOBAL:
1795 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1796 continue;
1797 break;
1798 default:
1799 continue;
1800 }
1801
1802 /*
1803 * check if anycast is okay.
1804 * XXX: just experimental. not in the spec.
1805 */
1806 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1807 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1808 continue;
1809 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1810 (icmp6_nodeinfo & 4) == 0) {
1811 continue;
1812 }
1813
1814 /* now we can copy the address */
1815 if (resid < sizeof(struct in6_addr) +
1816 sizeof(u_int32_t)) {
1817 /*
1818 * We give up much more copy.
1819 * Set the truncate flag and return.
1820 */
1821 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1822 IFNET_RUNLOCK();
1823 return (copied);
1824 }
1825
1826 /*
1827 * Set the TTL of the address.
1828 * The TTL value should be one of the following
1829 * according to the specification:
1830 *
1831 * 1. The remaining lifetime of a DHCP lease on the
1832 * address, or
1833 * 2. The remaining Valid Lifetime of a prefix from
1834 * which the address was derived through Stateless
1835 * Autoconfiguration.
1836 *
1837 * Note that we currently do not support stateful
1838 * address configuration by DHCPv6, so the former
1839 * case can't happen.
1840 */
1841 if (ifa6->ia6_lifetime.ia6t_expire == 0)
1842 ltime = ND6_INFINITE_LIFETIME;
1843 else {
1844 if (ifa6->ia6_lifetime.ia6t_expire >
1845 time_second)
1846 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1847 else
1848 ltime = 0;
1849 }
1850
1851 bcopy(<ime, cp, sizeof(u_int32_t));
1852 cp += sizeof(u_int32_t);
1853
1854 /* copy the address itself */
1855 bcopy(&ifa6->ia_addr.sin6_addr, cp,
1856 sizeof(struct in6_addr));
1857 in6_clearscope((struct in6_addr *)cp); /* XXX */
1858 cp += sizeof(struct in6_addr);
1859
1860 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1861 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1862 }
1863 if (ifp0) /* we need search only on the specified IF */
1864 break;
1865 }
1866
1867 if (allow_deprecated == 0 && ifp_dep != NULL) {
1868 ifp = ifp_dep;
1869 allow_deprecated = 1;
1870
1871 goto again;
1872 }
1873
1874 IFNET_RUNLOCK();
1875
1876 return (copied);
1877 }
1878
1879 /*
1880 * XXX almost dup'ed code with rip6_input.
1881 */
1882 static int
1883 icmp6_rip6_input(mp, off)
1884 struct mbuf **mp;
1885 int off;
1886 {
1887 struct mbuf *m = *mp;
1888 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1889 struct in6pcb *in6p;
1890 struct in6pcb *last = NULL;
1891 struct sockaddr_in6 fromsa;
1892 struct icmp6_hdr *icmp6;
1893 struct mbuf *opts = NULL;
1894
1895 #ifndef PULLDOWN_TEST
1896 /* this is assumed to be safe. */
1897 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1898 #else
1899 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1900 if (icmp6 == NULL) {
1901 /* m is already reclaimed */
1902 return (IPPROTO_DONE);
1903 }
1904 #endif
1905
1906 bzero(&fromsa, sizeof(fromsa));
1907 fromsa.sin6_len = sizeof(struct sockaddr_in6);
1908 fromsa.sin6_family = AF_INET6;
1909 /* KAME hack: recover scopeid */
1910 (void)in6_recoverscope(&fromsa, &ip6->ip6_src, m->m_pkthdr.rcvif);
1911
1912 LIST_FOREACH(in6p, &ripcb, inp_list) {
1913 if ((in6p->inp_vflag & INP_IPV6) == 0)
1914 continue;
1915 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1916 continue;
1917 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1918 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1919 continue;
1920 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1921 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1922 continue;
1923 if (in6p->in6p_icmp6filt
1924 && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1925 in6p->in6p_icmp6filt))
1926 continue;
1927 if (last) {
1928 struct mbuf *n = NULL;
1929
1930 /*
1931 * Recent network drivers tend to allocate a single
1932 * mbuf cluster, rather than to make a couple of
1933 * mbufs without clusters. Also, since the IPv6 code
1934 * path tries to avoid m_pullup(), it is highly
1935 * probable that we still have an mbuf cluster here
1936 * even though the necessary length can be stored in an
1937 * mbuf's internal buffer.
1938 * Meanwhile, the default size of the receive socket
1939 * buffer for raw sockets is not so large. This means
1940 * the possibility of packet loss is relatively higher
1941 * than before. To avoid this scenario, we copy the
1942 * received data to a separate mbuf that does not use
1943 * a cluster, if possible.
1944 * XXX: it is better to copy the data after stripping
1945 * intermediate headers.
1946 */
1947 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1948 m->m_len <= MHLEN) {
1949 MGET(n, M_DONTWAIT, m->m_type);
1950 if (n != NULL) {
1951 m_dup_pkthdr(n, m, M_NOWAIT);
1952 bcopy(m->m_data, n->m_data, m->m_len);
1953 n->m_len = m->m_len;
1954 }
1955 }
1956 if (n != NULL ||
1957 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1958 if (last->in6p_flags & IN6P_CONTROLOPTS)
1959 ip6_savecontrol(last, n, &opts);
1960 /* strip intermediate headers */
1961 m_adj(n, off);
1962 if (sbappendaddr(&last->in6p_socket->so_rcv,
1963 (struct sockaddr *)&fromsa, n, opts)
1964 == 0) {
1965 /* should notify about lost packet */
1966 m_freem(n);
1967 if (opts) {
1968 m_freem(opts);
1969 }
1970 } else
1971 sorwakeup(last->in6p_socket);
1972 opts = NULL;
1973 }
1974 }
1975 last = in6p;
1976 }
1977 if (last) {
1978 if (last->in6p_flags & IN6P_CONTROLOPTS)
1979 ip6_savecontrol(last, m, &opts);
1980 /* strip intermediate headers */
1981 m_adj(m, off);
1982
1983 /* avoid using mbuf clusters if possible (see above) */
1984 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1985 m->m_len <= MHLEN) {
1986 struct mbuf *n;
1987
1988 MGET(n, M_DONTWAIT, m->m_type);
1989 if (n != NULL) {
1990 m_dup_pkthdr(n, m, M_NOWAIT);
1991 bcopy(m->m_data, n->m_data, m->m_len);
1992 n->m_len = m->m_len;
1993
1994 m_freem(m);
1995 m = n;
1996 }
1997 }
1998 if (sbappendaddr(&last->in6p_socket->so_rcv,
1999 (struct sockaddr *)&fromsa, m, opts) == 0) {
2000 m_freem(m);
2001 if (opts)
2002 m_freem(opts);
2003 } else
2004 sorwakeup(last->in6p_socket);
2005 } else {
2006 m_freem(m);
2007 ip6stat.ip6s_delivered--;
2008 }
2009 return IPPROTO_DONE;
2010 }
2011
2012 /*
2013 * Reflect the ip6 packet back to the source.
2014 * OFF points to the icmp6 header, counted from the top of the mbuf.
2015 */
2016 void
2017 icmp6_reflect(m, off)
2018 struct mbuf *m;
2019 size_t off;
2020 {
2021 struct ip6_hdr *ip6;
2022 struct icmp6_hdr *icmp6;
2023 struct in6_ifaddr *ia;
2024 struct in6_addr t, *src = 0;
2025 int plen;
2026 int type, code;
2027 struct ifnet *outif = NULL;
2028 struct sockaddr_in6 sa6_src, sa6_dst;
2029 #ifdef COMPAT_RFC1885
2030 int mtu = IPV6_MMTU;
2031 struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
2032 #endif
2033
2034 /* too short to reflect */
2035 if (off < sizeof(struct ip6_hdr)) {
2036 nd6log((LOG_DEBUG,
2037 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2038 (u_long)off, (u_long)sizeof(struct ip6_hdr),
2039 __FILE__, __LINE__));
2040 goto bad;
2041 }
2042
2043 /*
2044 * If there are extra headers between IPv6 and ICMPv6, strip
2045 * off that header first.
2046 */
2047 #ifdef DIAGNOSTIC
2048 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2049 panic("assumption failed in icmp6_reflect");
2050 #endif
2051 if (off > sizeof(struct ip6_hdr)) {
2052 size_t l;
2053 struct ip6_hdr nip6;
2054
2055 l = off - sizeof(struct ip6_hdr);
2056 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2057 m_adj(m, l);
2058 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2059 if (m->m_len < l) {
2060 if ((m = m_pullup(m, l)) == NULL)
2061 return;
2062 }
2063 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2064 } else /* off == sizeof(struct ip6_hdr) */ {
2065 size_t l;
2066 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2067 if (m->m_len < l) {
2068 if ((m = m_pullup(m, l)) == NULL)
2069 return;
2070 }
2071 }
2072 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2073 ip6 = mtod(m, struct ip6_hdr *);
2074 ip6->ip6_nxt = IPPROTO_ICMPV6;
2075 icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2076 type = icmp6->icmp6_type; /* keep type for statistics */
2077 code = icmp6->icmp6_code; /* ditto. */
2078
2079 t = ip6->ip6_dst;
2080 /*
2081 * ip6_input() drops a packet if its src is multicast.
2082 * So, the src is never multicast.
2083 */
2084 ip6->ip6_dst = ip6->ip6_src;
2085
2086 /*
2087 * XXX: make sure to embed scope zone information, using
2088 * already embedded IDs or the received interface (if any).
2089 * Note that rcvif may be NULL.
2090 * TODO: scoped routing case (XXX).
2091 */
2092 bzero(&sa6_src, sizeof(sa6_src));
2093 sa6_src.sin6_family = AF_INET6;
2094 sa6_src.sin6_len = sizeof(sa6_src);
2095 sa6_src.sin6_addr = ip6->ip6_dst;
2096 in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
2097 in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL);
2098 bzero(&sa6_dst, sizeof(sa6_dst));
2099 sa6_dst.sin6_family = AF_INET6;
2100 sa6_dst.sin6_len = sizeof(sa6_dst);
2101 sa6_dst.sin6_addr = t;
2102 in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
2103 in6_embedscope(&t, &sa6_dst, NULL, NULL);
2104
2105 #ifdef COMPAT_RFC1885
2106 /*
2107 * xxx guess MTU
2108 * RFC 1885 requires that echo reply should be truncated if it
2109 * does not fit in with (return) path MTU, but the description was
2110 * removed in the new spec.
2111 */
2112 if (icmp6_reflect_rt.ro_rt == 0 ||
2113 ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
2114 if (icmp6_reflect_rt.ro_rt) {
2115 RTFREE(icmp6_reflect_rt.ro_rt);
2116 icmp6_reflect_rt.ro_rt = 0;
2117 }
2118 bzero(sin6, sizeof(*sin6));
2119 sin6->sin6_family = PF_INET6;
2120 sin6->sin6_len = sizeof(struct sockaddr_in6);
2121 sin6->sin6_addr = ip6->ip6_dst;
2122
2123 rtalloc((struct route *)&icmp6_reflect_rt.ro_rt);
2124 }
2125
2126 if (icmp6_reflect_rt.ro_rt == 0)
2127 goto bad;
2128
2129 if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
2130 && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
2131 mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
2132
2133 if (mtu < m->m_pkthdr.len) {
2134 plen -= (m->m_pkthdr.len - mtu);
2135 m_adj(m, mtu - m->m_pkthdr.len);
2136 }
2137 #endif
2138 /*
2139 * If the incoming packet was addressed directly to us (i.e. unicast),
2140 * use dst as the src for the reply.
2141 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2142 * (for example) when we encounter an error while forwarding procedure
2143 * destined to a duplicated address of ours.
2144 */
2145 for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2146 if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2147 (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2148 src = &t;
2149 break;
2150 }
2151 if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2152 /*
2153 * This is the case if the dst is our link-local address
2154 * and the sender is also ourselves.
2155 */
2156 src = &t;
2157 }
2158
2159 if (src == 0) {
2160 int e;
2161 struct route_in6 ro;
2162
2163 /*
2164 * This case matches to multicasts, our anycast, or unicasts
2165 * that we do not own. Select a source address based on the
2166 * source address of the erroneous packet.
2167 */
2168 bzero(&ro, sizeof(ro));
2169 src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e);
2170 if (ro.ro_rt)
2171 RTFREE(ro.ro_rt); /* XXX: we could use this */
2172 if (src == NULL) {
2173 nd6log((LOG_DEBUG,
2174 "icmp6_reflect: source can't be determined: "
2175 "dst=%s, error=%d\n",
2176 ip6_sprintf(&sa6_src.sin6_addr), e));
2177 goto bad;
2178 }
2179 }
2180
2181 ip6->ip6_src = *src;
2182
2183 ip6->ip6_flow = 0;
2184 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2185 ip6->ip6_vfc |= IPV6_VERSION;
2186 ip6->ip6_nxt = IPPROTO_ICMPV6;
2187 if (outif)
2188 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2189 else if (m->m_pkthdr.rcvif) {
2190 /* XXX: This may not be the outgoing interface */
2191 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2192 } else
2193 ip6->ip6_hlim = ip6_defhlim;
2194
2195 icmp6->icmp6_cksum = 0;
2196 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2197 sizeof(struct ip6_hdr), plen);
2198
2199 /*
2200 * XXX option handling
2201 */
2202
2203 m->m_flags &= ~(M_BCAST|M_MCAST);
2204
2205 #ifdef COMPAT_RFC1885
2206 ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif, NULL);
2207 #else
2208 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2209 #endif
2210 if (outif)
2211 icmp6_ifoutstat_inc(outif, type, code);
2212
2213 return;
2214
2215 bad:
2216 m_freem(m);
2217 return;
2218 }
2219
2220 void
2221 icmp6_fasttimo()
2222 {
2223
2224 mld6_fasttimeo();
2225 }
2226
2227 static const char *
2228 icmp6_redirect_diag(src6, dst6, tgt6)
2229 struct in6_addr *src6;
2230 struct in6_addr *dst6;
2231 struct in6_addr *tgt6;
2232 {
2233 static char buf[1024];
2234 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2235 ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2236 return buf;
2237 }
2238
2239 void
2240 icmp6_redirect_input(m, off)
2241 struct mbuf *m;
2242 int off;
2243 {
2244 struct ifnet *ifp = m->m_pkthdr.rcvif;
2245 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2246 struct nd_redirect *nd_rd;
2247 int icmp6len = ntohs(ip6->ip6_plen);
2248 char *lladdr = NULL;
2249 int lladdrlen = 0;
2250 u_char *redirhdr = NULL;
2251 int redirhdrlen = 0;
2252 struct rtentry *rt = NULL;
2253 int is_router;
2254 int is_onlink;
2255 struct in6_addr src6 = ip6->ip6_src;
2256 struct in6_addr redtgt6;
2257 struct in6_addr reddst6;
2258 union nd_opts ndopts;
2259
2260 if (!m || !ifp)
2261 return;
2262
2263 /* XXX if we are router, we don't update route by icmp6 redirect */
2264 if (ip6_forwarding)
2265 goto freeit;
2266 if (!icmp6_rediraccept)
2267 goto freeit;
2268
2269 #ifndef PULLDOWN_TEST
2270 IP6_EXTHDR_CHECK(m, off, icmp6len,);
2271 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2272 #else
2273 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2274 if (nd_rd == NULL) {
2275 icmp6stat.icp6s_tooshort++;
2276 return;
2277 }
2278 #endif
2279 redtgt6 = nd_rd->nd_rd_target;
2280 reddst6 = nd_rd->nd_rd_dst;
2281
2282 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2283 redtgt6.s6_addr16[1] = htons(ifp->if_index);
2284 if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2285 reddst6.s6_addr16[1] = htons(ifp->if_index);
2286
2287 /* validation */
2288 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2289 nd6log((LOG_ERR,
2290 "ICMP6 redirect sent from %s rejected; "
2291 "must be from linklocal\n",
2292 ip6_sprintf(&src6)));
2293 goto bad;
2294 }
2295 if (ip6->ip6_hlim != 255) {
2296 nd6log((LOG_ERR,
2297 "ICMP6 redirect sent from %s rejected; "
2298 "hlim=%d (must be 255)\n",
2299 ip6_sprintf(&src6), ip6->ip6_hlim));
2300 goto bad;
2301 }
2302 {
2303 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2304 struct sockaddr_in6 sin6;
2305 struct in6_addr *gw6;
2306
2307 bzero(&sin6, sizeof(sin6));
2308 sin6.sin6_family = AF_INET6;
2309 sin6.sin6_len = sizeof(struct sockaddr_in6);
2310 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2311 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2312 if (rt) {
2313 if (rt->rt_gateway == NULL ||
2314 rt->rt_gateway->sa_family != AF_INET6) {
2315 nd6log((LOG_ERR,
2316 "ICMP6 redirect rejected; no route "
2317 "with inet6 gateway found for redirect dst: %s\n",
2318 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2319 RTFREE_LOCKED(rt);
2320 goto bad;
2321 }
2322
2323 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2324 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2325 nd6log((LOG_ERR,
2326 "ICMP6 redirect rejected; "
2327 "not equal to gw-for-src=%s (must be same): "
2328 "%s\n",
2329 ip6_sprintf(gw6),
2330 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2331 RTFREE_LOCKED(rt);
2332 goto bad;
2333 }
2334 } else {
2335 nd6log((LOG_ERR,
2336 "ICMP6 redirect rejected; "
2337 "no route found for redirect dst: %s\n",
2338 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2339 goto bad;
2340 }
2341 RTFREE_LOCKED(rt);
2342 rt = NULL;
2343 }
2344 if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2345 nd6log((LOG_ERR,
2346 "ICMP6 redirect rejected; "
2347 "redirect dst must be unicast: %s\n",
2348 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2349 goto bad;
2350 }
2351
2352 is_router = is_onlink = 0;
2353 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2354 is_router = 1; /* router case */
2355 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2356 is_onlink = 1; /* on-link destination case */
2357 if (!is_router && !is_onlink) {
2358 nd6log((LOG_ERR,
2359 "ICMP6 redirect rejected; "
2360 "neither router case nor onlink case: %s\n",
2361 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2362 goto bad;
2363 }
2364 /* validation passed */
2365
2366 icmp6len -= sizeof(*nd_rd);
2367 nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2368 if (nd6_options(&ndopts) < 0) {
2369 nd6log((LOG_INFO, "icmp6_redirect_input: "
2370 "invalid ND option, rejected: %s\n",
2371 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2372 /* nd6_options have incremented stats */
2373 goto freeit;
2374 }
2375
2376 if (ndopts.nd_opts_tgt_lladdr) {
2377 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2378 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2379 }
2380
2381 if (ndopts.nd_opts_rh) {
2382 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2383 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2384 }
2385
2386 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2387 nd6log((LOG_INFO,
2388 "icmp6_redirect_input: lladdrlen mismatch for %s "
2389 "(if %d, icmp6 packet %d): %s\n",
2390 ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2391 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2392 goto bad;
2393 }
2394
2395 /* RFC 2461 8.3 */
2396 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2397 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2398
2399 if (!is_onlink) { /* better router case. perform rtredirect. */
2400 /* perform rtredirect */
2401 struct sockaddr_in6 sdst;
2402 struct sockaddr_in6 sgw;
2403 struct sockaddr_in6 ssrc;
2404
2405 bzero(&sdst, sizeof(sdst));
2406 bzero(&sgw, sizeof(sgw));
2407 bzero(&ssrc, sizeof(ssrc));
2408 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2409 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2410 sizeof(struct sockaddr_in6);
2411 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2412 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2413 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2414 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2415 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2416 (struct sockaddr *)&ssrc);
2417 }
2418 /* finally update cached route in each socket via pfctlinput */
2419 {
2420 struct sockaddr_in6 sdst;
2421
2422 bzero(&sdst, sizeof(sdst));
2423 sdst.sin6_family = AF_INET6;
2424 sdst.sin6_len = sizeof(struct sockaddr_in6);
2425 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2426 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2427 #if defined(IPSEC) || defined(FAST_IPSEC)
2428 key_sa_routechange((struct sockaddr *)&sdst);
2429 #endif
2430 }
2431
2432 freeit:
2433 m_freem(m);
2434 return;
2435
2436 bad:
2437 icmp6stat.icp6s_badredirect++;
2438 m_freem(m);
2439 }
2440
2441 void
2442 icmp6_redirect_output(m0, rt)
2443 struct mbuf *m0;
2444 struct rtentry *rt;
2445 {
2446 struct ifnet *ifp; /* my outgoing interface */
2447 struct in6_addr *ifp_ll6;
2448 struct in6_addr *router_ll6;
2449 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
2450 struct mbuf *m = NULL; /* newly allocated one */
2451 struct ip6_hdr *ip6; /* m as struct ip6_hdr */
2452 struct nd_redirect *nd_rd;
2453 size_t maxlen;
2454 u_char *p;
2455 struct ifnet *outif = NULL;
2456 struct sockaddr_in6 src_sa;
2457
2458 icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2459
2460 /* if we are not router, we don't send icmp6 redirect */
2461 if (!ip6_forwarding || ip6_accept_rtadv)
2462 goto fail;
2463
2464 /* sanity check */
2465 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2466 goto fail;
2467
2468 /*
2469 * Address check:
2470 * the source address must identify a neighbor, and
2471 * the destination address must not be a multicast address
2472 * [RFC 2461, sec 8.2]
2473 */
2474 sip6 = mtod(m0, struct ip6_hdr *);
2475 bzero(&src_sa, sizeof(src_sa));
2476 src_sa.sin6_family = AF_INET6;
2477 src_sa.sin6_len = sizeof(src_sa);
2478 src_sa.sin6_addr = sip6->ip6_src;
2479 /* we don't currently use sin6_scope_id, but eventually use it */
2480 if (in6_addr2zoneid(ifp, &sip6->ip6_src, &src_sa.sin6_scope_id))
2481 goto fail;
2482 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2483 goto fail;
2484 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2485 goto fail; /* what should we do here? */
2486
2487 /* rate limit */
2488 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2489 goto fail;
2490
2491 /*
2492 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2493 * we almost always ask for an mbuf cluster for simplicity.
2494 * (MHLEN < IPV6_MMTU is almost always true)
2495 */
2496 #if IPV6_MMTU >= MCLBYTES
2497 # error assumption failed about IPV6_MMTU and MCLBYTES
2498 #endif
2499 MGETHDR(m, M_DONTWAIT, MT_HEADER);
2500 if (m && IPV6_MMTU >= MHLEN)
2501 MCLGET(m, M_DONTWAIT);
2502 if (!m)
2503 goto fail;
2504 m->m_pkthdr.rcvif = NULL;
2505 m->m_len = 0;
2506 maxlen = M_TRAILINGSPACE(m);
2507 maxlen = min(IPV6_MMTU, maxlen);
2508 /* just for safety */
2509 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2510 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2511 goto fail;
2512 }
2513
2514 {
2515 /* get ip6 linklocal address for ifp(my outgoing interface). */
2516 struct in6_ifaddr *ia;
2517 if ((ia = in6ifa_ifpforlinklocal(ifp,
2518 IN6_IFF_NOTREADY|
2519 IN6_IFF_ANYCAST)) == NULL)
2520 goto fail;
2521 ifp_ll6 = &ia->ia_addr.sin6_addr;
2522 }
2523
2524 /* get ip6 linklocal address for the router. */
2525 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2526 struct sockaddr_in6 *sin6;
2527 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2528 router_ll6 = &sin6->sin6_addr;
2529 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2530 router_ll6 = (struct in6_addr *)NULL;
2531 } else
2532 router_ll6 = (struct in6_addr *)NULL;
2533
2534 /* ip6 */
2535 ip6 = mtod(m, struct ip6_hdr *);
2536 ip6->ip6_flow = 0;
2537 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2538 ip6->ip6_vfc |= IPV6_VERSION;
2539 /* ip6->ip6_plen will be set later */
2540 ip6->ip6_nxt = IPPROTO_ICMPV6;
2541 ip6->ip6_hlim = 255;
2542 /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2543 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2544 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2545
2546 /* ND Redirect */
2547 nd_rd = (struct nd_redirect *)(ip6 + 1);
2548 nd_rd->nd_rd_type = ND_REDIRECT;
2549 nd_rd->nd_rd_code = 0;
2550 nd_rd->nd_rd_reserved = 0;
2551 if (rt->rt_flags & RTF_GATEWAY) {
2552 /*
2553 * nd_rd->nd_rd_target must be a link-local address in
2554 * better router cases.
2555 */
2556 if (!router_ll6)
2557 goto fail;
2558 bcopy(router_ll6, &nd_rd->nd_rd_target,
2559 sizeof(nd_rd->nd_rd_target));
2560 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2561 sizeof(nd_rd->nd_rd_dst));
2562 } else {
2563 /* make sure redtgt == reddst */
2564 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2565 sizeof(nd_rd->nd_rd_target));
2566 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2567 sizeof(nd_rd->nd_rd_dst));
2568 }
2569
2570 p = (u_char *)(nd_rd + 1);
2571
2572 if (!router_ll6)
2573 goto nolladdropt;
2574
2575 {
2576 /* target lladdr option */
2577 struct rtentry *rt_router = NULL;
2578 int len;
2579 struct sockaddr_dl *sdl;
2580 struct nd_opt_hdr *nd_opt;
2581 char *lladdr;
2582
2583 rt_router = nd6_lookup(router_ll6, 0, ifp);
2584 if (!rt_router)
2585 goto nolladdropt;
2586 len = sizeof(*nd_opt) + ifp->if_addrlen;
2587 len = (len + 7) & ~7; /* round by 8 */
2588 /* safety check */
2589 if (len + (p - (u_char *)ip6) > maxlen)
2590 goto nolladdropt;
2591 if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2592 (rt_router->rt_flags & RTF_LLINFO) &&
2593 (rt_router->rt_gateway->sa_family == AF_LINK) &&
2594 (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2595 sdl->sdl_alen) {
2596 nd_opt = (struct nd_opt_hdr *)p;
2597 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2598 nd_opt->nd_opt_len = len >> 3;
2599 lladdr = (char *)(nd_opt + 1);
2600 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2601 p += len;
2602 }
2603 }
2604 nolladdropt:;
2605
2606 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2607
2608 /* just to be safe */
2609 #ifdef M_DECRYPTED /*not openbsd*/
2610 if (m0->m_flags & M_DECRYPTED)
2611 goto noredhdropt;
2612 #endif
2613 if (p - (u_char *)ip6 > maxlen)
2614 goto noredhdropt;
2615
2616 {
2617 /* redirected header option */
2618 int len;
2619 struct nd_opt_rd_hdr *nd_opt_rh;
2620
2621 /*
2622 * compute the maximum size for icmp6 redirect header option.
2623 * XXX room for auth header?
2624 */
2625 len = maxlen - (p - (u_char *)ip6);
2626 len &= ~7;
2627
2628 /* This is just for simplicity. */
2629 if (m0->m_pkthdr.len != m0->m_len) {
2630 if (m0->m_next) {
2631 m_freem(m0->m_next);
2632 m0->m_next = NULL;
2633 }
2634 m0->m_pkthdr.len = m0->m_len;
2635 }
2636
2637 /*
2638 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2639 * about padding/truncate rule for the original IP packet.
2640 * From the discussion on IPv6imp in Feb 1999,
2641 * the consensus was:
2642 * - "attach as much as possible" is the goal
2643 * - pad if not aligned (original size can be guessed by
2644 * original ip6 header)
2645 * Following code adds the padding if it is simple enough,
2646 * and truncates if not.
2647 */
2648 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2649 panic("assumption failed in %s:%d", __FILE__,
2650 __LINE__);
2651
2652 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2653 /* not enough room, truncate */
2654 m0->m_pkthdr.len = m0->m_len = len -
2655 sizeof(*nd_opt_rh);
2656 } else {
2657 /* enough room, pad or truncate */
2658 size_t extra;
2659
2660 extra = m0->m_pkthdr.len % 8;
2661 if (extra) {
2662 /* pad if easy enough, truncate if not */
2663 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2664 /* pad */
2665 m0->m_len += (8 - extra);
2666 m0->m_pkthdr.len += (8 - extra);
2667 } else {
2668 /* truncate */
2669 m0->m_pkthdr.len -= extra;
2670 m0->m_len -= extra;
2671 }
2672 }
2673 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2674 m0->m_pkthdr.len = m0->m_len = len -
2675 sizeof(*nd_opt_rh);
2676 }
2677
2678 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2679 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2680 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2681 nd_opt_rh->nd_opt_rh_len = len >> 3;
2682 p += sizeof(*nd_opt_rh);
2683 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2684
2685 /* connect m0 to m */
2686 m_tag_delete_chain(m0, NULL);
2687 m0->m_flags &= ~M_PKTHDR;
2688 m->m_next = m0;
2689 m->m_pkthdr.len = m->m_len + m0->m_len;
2690 m0 = NULL;
2691 }
2692 noredhdropt:;
2693 if (m0) {
2694 m_freem(m0);
2695 m0 = NULL;
2696 }
2697
2698 /* XXX: clear embedded link IDs in the inner header */
2699 in6_clearscope(&sip6->ip6_src);
2700 in6_clearscope(&sip6->ip6_dst);
2701 in6_clearscope(&nd_rd->nd_rd_target);
2702 in6_clearscope(&nd_rd->nd_rd_dst);
2703
2704 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2705
2706 nd_rd->nd_rd_cksum = 0;
2707 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2708 sizeof(*ip6), ntohs(ip6->ip6_plen));
2709
2710 /* send the packet to outside... */
2711 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2712 if (outif) {
2713 icmp6_ifstat_inc(outif, ifs6_out_msg);
2714 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2715 }
2716 icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2717
2718 return;
2719
2720 fail:
2721 if (m)
2722 m_freem(m);
2723 if (m0)
2724 m_freem(m0);
2725 }
2726
2727 /*
2728 * ICMPv6 socket option processing.
2729 */
2730 int
2731 icmp6_ctloutput(so, sopt)
2732 struct socket *so;
2733 struct sockopt *sopt;
2734 {
2735 int error = 0;
2736 int optlen;
2737 struct inpcb *inp = sotoinpcb(so);
2738 int level, op, optname;
2739
2740 if (sopt) {
2741 level = sopt->sopt_level;
2742 op = sopt->sopt_dir;
2743 optname = sopt->sopt_name;
2744 optlen = sopt->sopt_valsize;
2745 } else
2746 level = op = optname = optlen = 0;
2747
2748 if (level != IPPROTO_ICMPV6) {
2749 return EINVAL;
2750 }
2751
2752 switch (op) {
2753 case PRCO_SETOPT:
2754 switch (optname) {
2755 case ICMP6_FILTER:
2756 {
2757 struct icmp6_filter *p;
2758
2759 if (optlen != sizeof(*p)) {
2760 error = EMSGSIZE;
2761 break;
2762 }
2763 if (inp->in6p_icmp6filt == NULL) {
2764 error = EINVAL;
2765 break;
2766 }
2767 error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen,
2768 optlen);
2769 break;
2770 }
2771
2772 default:
2773 error = ENOPROTOOPT;
2774 break;
2775 }
2776 break;
2777
2778 case PRCO_GETOPT:
2779 switch (optname) {
2780 case ICMP6_FILTER:
2781 {
2782 if (inp->in6p_icmp6filt == NULL) {
2783 error = EINVAL;
2784 break;
2785 }
2786 error = sooptcopyout(sopt, inp->in6p_icmp6filt,
2787 sizeof(struct icmp6_filter));
2788 break;
2789 }
2790
2791 default:
2792 error = ENOPROTOOPT;
2793 break;
2794 }
2795 break;
2796 }
2797
2798 return (error);
2799 }
2800
2801 /*
2802 * Perform rate limit check.
2803 * Returns 0 if it is okay to send the icmp6 packet.
2804 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2805 * limitation.
2806 *
2807 * XXX per-destination/type check necessary?
2808 */
2809 static int
2810 icmp6_ratelimit(dst, type, code)
2811 const struct in6_addr *dst; /* not used at this moment */
2812 const int type; /* not used at this moment */
2813 const int code; /* not used at this moment */
2814 {
2815 int ret;
2816
2817 ret = 0; /* okay to send */
2818
2819 /* PPS limit */
2820 if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2821 icmp6errppslim)) {
2822 /* The packet is subject to rate limit */
2823 ret++;
2824 }
2825
2826 return ret;
2827 }
Cache object: 5f29f16a96919a0f182fcfeacead8fad
|