155/*
156 * Kernel module interface for updating icmp6stat. The argument is an index
157 * into icmp6stat treated as an array of u_quad_t. While this encodes the
158 * general layout of icmp6stat into the caller, it doesn't encode its
159 * location, so that future changes to add, for example, per-CPU stats
160 * support won't cause binary compatibility problems for kernel modules.
161 */
162void
163kmod_icmp6stat_inc(int statnum)
164{
165
166 (*((u_quad_t *)&V_icmp6stat + statnum))++;
167}
168
169static void
170icmp6_errcount(struct icmp6errstat *stat, int type, int code)
171{
172 switch (type) {
173 case ICMP6_DST_UNREACH:
174 switch (code) {
175 case ICMP6_DST_UNREACH_NOROUTE:
176 stat->icp6errs_dst_unreach_noroute++;
177 return;
178 case ICMP6_DST_UNREACH_ADMIN:
179 stat->icp6errs_dst_unreach_admin++;
180 return;
181 case ICMP6_DST_UNREACH_BEYONDSCOPE:
182 stat->icp6errs_dst_unreach_beyondscope++;
183 return;
184 case ICMP6_DST_UNREACH_ADDR:
185 stat->icp6errs_dst_unreach_addr++;
186 return;
187 case ICMP6_DST_UNREACH_NOPORT:
188 stat->icp6errs_dst_unreach_noport++;
189 return;
190 }
191 break;
192 case ICMP6_PACKET_TOO_BIG:
193 stat->icp6errs_packet_too_big++;
194 return;
195 case ICMP6_TIME_EXCEEDED:
196 switch (code) {
197 case ICMP6_TIME_EXCEED_TRANSIT:
198 stat->icp6errs_time_exceed_transit++;
199 return;
200 case ICMP6_TIME_EXCEED_REASSEMBLY:
201 stat->icp6errs_time_exceed_reassembly++;
202 return;
203 }
204 break;
205 case ICMP6_PARAM_PROB:
206 switch (code) {
207 case ICMP6_PARAMPROB_HEADER:
208 stat->icp6errs_paramprob_header++;
209 return;
210 case ICMP6_PARAMPROB_NEXTHEADER:
211 stat->icp6errs_paramprob_nextheader++;
212 return;
213 case ICMP6_PARAMPROB_OPTION:
214 stat->icp6errs_paramprob_option++;
215 return;
216 }
217 break;
218 case ND_REDIRECT:
219 stat->icp6errs_redirect++;
220 return;
221 }
222 stat->icp6errs_unknown++;
223}
224
225/*
226 * A wrapper function for icmp6_error() necessary when the erroneous packet
227 * may not contain enough scope zone information.
228 */
229void
230icmp6_error2(struct mbuf *m, int type, int code, int param,
231 struct ifnet *ifp)
232{
233 struct ip6_hdr *ip6;
234
235 if (ifp == NULL)
236 return;
237
238#ifndef PULLDOWN_TEST
239 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
240#else
241 if (m->m_len < sizeof(struct ip6_hdr)) {
242 m = m_pullup(m, sizeof(struct ip6_hdr));
243 if (m == NULL)
244 return;
245 }
246#endif
247
248 ip6 = mtod(m, struct ip6_hdr *);
249
250 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
251 return;
252 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
253 return;
254
255 icmp6_error(m, type, code, param);
256}
257
258/*
259 * Generate an error packet of type error in response to bad IP6 packet.
260 */
261void
262icmp6_error(struct mbuf *m, int type, int code, int param)
263{
264 struct ip6_hdr *oip6, *nip6;
265 struct icmp6_hdr *icmp6;
266 u_int preplen;
267 int off;
268 int nxt;
269
270 ICMP6STAT_INC(icp6s_error);
271
272 /* count per-type-code statistics */
273 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code);
274
275#ifdef M_DECRYPTED /*not openbsd*/
276 if (m->m_flags & M_DECRYPTED) {
277 ICMP6STAT_INC(icp6s_canterror);
278 goto freeit;
279 }
280#endif
281
282#ifndef PULLDOWN_TEST
283 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
284#else
285 if (m->m_len < sizeof(struct ip6_hdr)) {
286 m = m_pullup(m, sizeof(struct ip6_hdr));
287 if (m == NULL)
288 return;
289 }
290#endif
291 oip6 = mtod(m, struct ip6_hdr *);
292
293 /*
294 * If the destination address of the erroneous packet is a multicast
295 * address, or the packet was sent using link-layer multicast,
296 * we should basically suppress sending an error (RFC 2463, Section
297 * 2.4).
298 * We have two exceptions (the item e.2 in that section):
299 * - the Packet Too Big message can be sent for path MTU discovery.
300 * - the Parameter Problem Message that can be allowed an icmp6 error
301 * in the option type field. This check has been done in
302 * ip6_unknown_opt(), so we can just check the type and code.
303 */
304 if ((m->m_flags & (M_BCAST|M_MCAST) ||
305 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
306 (type != ICMP6_PACKET_TOO_BIG &&
307 (type != ICMP6_PARAM_PROB ||
308 code != ICMP6_PARAMPROB_OPTION)))
309 goto freeit;
310
311 /*
312 * RFC 2463, 2.4 (e.5): source address check.
313 * XXX: the case of anycast source?
314 */
315 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
316 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
317 goto freeit;
318
319 /*
320 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
321 * don't do it.
322 */
323 nxt = -1;
324 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
325 if (off >= 0 && nxt == IPPROTO_ICMPV6) {
326 struct icmp6_hdr *icp;
327
328#ifndef PULLDOWN_TEST
329 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
330 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
331#else
332 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
333 sizeof(*icp));
334 if (icp == NULL) {
335 ICMP6STAT_INC(icp6s_tooshort);
336 return;
337 }
338#endif
339 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
340 icp->icmp6_type == ND_REDIRECT) {
341 /*
342 * ICMPv6 error
343 * Special case: for redirect (which is
344 * informational) we must not send icmp6 error.
345 */
346 ICMP6STAT_INC(icp6s_canterror);
347 goto freeit;
348 } else {
349 /* ICMPv6 informational - send the error */
350 }
351 } else {
352 /* non-ICMPv6 - send the error */
353 }
354
355 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
356
357 /* Finally, do rate limitation check. */
358 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
359 ICMP6STAT_INC(icp6s_toofreq);
360 goto freeit;
361 }
362
363 /*
364 * OK, ICMP6 can be generated.
365 */
366
367 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
368 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
369
370 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
371 M_PREPEND(m, preplen, M_DONTWAIT);
372 if (m && m->m_len < preplen)
373 m = m_pullup(m, preplen);
374 if (m == NULL) {
375 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
376 return;
377 }
378
379 nip6 = mtod(m, struct ip6_hdr *);
380 nip6->ip6_src = oip6->ip6_src;
381 nip6->ip6_dst = oip6->ip6_dst;
382
383 in6_clearscope(&oip6->ip6_src);
384 in6_clearscope(&oip6->ip6_dst);
385
386 icmp6 = (struct icmp6_hdr *)(nip6 + 1);
387 icmp6->icmp6_type = type;
388 icmp6->icmp6_code = code;
389 icmp6->icmp6_pptr = htonl((u_int32_t)param);
390
391 /*
392 * icmp6_reflect() is designed to be in the input path.
393 * icmp6_error() can be called from both input and output path,
394 * and if we are in output path rcvif could contain bogus value.
395 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
396 * information in ip header (nip6).
397 */
398 m->m_pkthdr.rcvif = NULL;
399
400 ICMP6STAT_INC(icp6s_outhist[type]);
401 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
402
403 return;
404
405 freeit:
406 /*
407 * If we can't tell whether or not we can generate ICMP6, free it.
408 */
409 m_freem(m);
410}
411
412/*
413 * Process a received ICMP6 message.
414 */
415int
416icmp6_input(struct mbuf **mp, int *offp, int proto)
417{
418 struct mbuf *m = *mp, *n;
419 struct ifnet *ifp;
420 struct ip6_hdr *ip6, *nip6;
421 struct icmp6_hdr *icmp6, *nicmp6;
422 int off = *offp;
423 int icmp6len = m->m_pkthdr.len - *offp;
424 int code, sum, noff;
425 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
426
427 ifp = m->m_pkthdr.rcvif;
428
429#ifndef PULLDOWN_TEST
430 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
431 /* m might change if M_LOOP. So, call mtod after this */
432#endif
433
434 /*
435 * Locate icmp6 structure in mbuf, and check
436 * that not corrupted and of at least minimum length
437 */
438
439 ip6 = mtod(m, struct ip6_hdr *);
440 if (icmp6len < sizeof(struct icmp6_hdr)) {
441 ICMP6STAT_INC(icp6s_tooshort);
442 goto freeit;
443 }
444
445 /*
446 * Check multicast group membership.
447 * Note: SSM filters are not applied for ICMPv6 traffic.
448 */
449 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
450 struct in6_multi *inm;
451
452 inm = in6m_lookup(ifp, &ip6->ip6_dst);
453 if (inm == NULL) {
454 IP6STAT_INC(ip6s_notmember);
455 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
456 goto freeit;
457 }
458 }
459
460 /*
461 * calculate the checksum
462 */
463#ifndef PULLDOWN_TEST
464 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
465#else
466 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
467 if (icmp6 == NULL) {
468 ICMP6STAT_INC(icp6s_tooshort);
469 return IPPROTO_DONE;
470 }
471#endif
472 code = icmp6->icmp6_code;
473
474 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
475 nd6log((LOG_ERR,
476 "ICMP6 checksum error(%d|%x) %s\n",
477 icmp6->icmp6_type, sum,
478 ip6_sprintf(ip6bufs, &ip6->ip6_src)));
479 ICMP6STAT_INC(icp6s_checksum);
480 goto freeit;
481 }
482
483 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
484 /*
485 * Deliver very specific ICMP6 type only.
486 * This is important to deliver TOOBIG. Otherwise PMTUD
487 * will not work.
488 */
489 switch (icmp6->icmp6_type) {
490 case ICMP6_DST_UNREACH:
491 case ICMP6_PACKET_TOO_BIG:
492 case ICMP6_TIME_EXCEEDED:
493 break;
494 default:
495 goto freeit;
496 }
497 }
498
499 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
500 icmp6_ifstat_inc(ifp, ifs6_in_msg);
501 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
502 icmp6_ifstat_inc(ifp, ifs6_in_error);
503
504 switch (icmp6->icmp6_type) {
505 case ICMP6_DST_UNREACH:
506 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
507 switch (code) {
508 case ICMP6_DST_UNREACH_NOROUTE:
509 code = PRC_UNREACH_NET;
510 break;
511 case ICMP6_DST_UNREACH_ADMIN:
512 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
513 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
514 break;
515 case ICMP6_DST_UNREACH_ADDR:
516 code = PRC_HOSTDEAD;
517 break;
518 case ICMP6_DST_UNREACH_BEYONDSCOPE:
519 /* I mean "source address was incorrect." */
520 code = PRC_PARAMPROB;
521 break;
522 case ICMP6_DST_UNREACH_NOPORT:
523 code = PRC_UNREACH_PORT;
524 break;
525 default:
526 goto badcode;
527 }
528 goto deliver;
529 break;
530
531 case ICMP6_PACKET_TOO_BIG:
532 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
533
534 /* validation is made in icmp6_mtudisc_update */
535
536 code = PRC_MSGSIZE;
537
538 /*
539 * Updating the path MTU will be done after examining
540 * intermediate extension headers.
541 */
542 goto deliver;
543 break;
544
545 case ICMP6_TIME_EXCEEDED:
546 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
547 switch (code) {
548 case ICMP6_TIME_EXCEED_TRANSIT:
549 code = PRC_TIMXCEED_INTRANS;
550 break;
551 case ICMP6_TIME_EXCEED_REASSEMBLY:
552 code = PRC_TIMXCEED_REASS;
553 break;
554 default:
555 goto badcode;
556 }
557 goto deliver;
558 break;
559
560 case ICMP6_PARAM_PROB:
561 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
562 switch (code) {
563 case ICMP6_PARAMPROB_NEXTHEADER:
564 code = PRC_UNREACH_PROTOCOL;
565 break;
566 case ICMP6_PARAMPROB_HEADER:
567 case ICMP6_PARAMPROB_OPTION:
568 code = PRC_PARAMPROB;
569 break;
570 default:
571 goto badcode;
572 }
573 goto deliver;
574 break;
575
576 case ICMP6_ECHO_REQUEST:
577 icmp6_ifstat_inc(ifp, ifs6_in_echo);
578 if (code != 0)
579 goto badcode;
580 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
581 /* Give up remote */
582 break;
583 }
584 if ((n->m_flags & M_EXT) != 0
585 || n->m_len < off + sizeof(struct icmp6_hdr)) {
586 struct mbuf *n0 = n;
587 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
588 int n0len;
589
590 MGETHDR(n, M_DONTWAIT, n0->m_type);
591 n0len = n0->m_pkthdr.len; /* save for use below */
592 if (n)
593 M_MOVE_PKTHDR(n, n0);
594 if (n && maxlen >= MHLEN) {
595 MCLGET(n, M_DONTWAIT);
596 if ((n->m_flags & M_EXT) == 0) {
597 m_free(n);
598 n = NULL;
599 }
600 }
601 if (n == NULL) {
602 /* Give up remote */
603 m_freem(n0);
604 break;
605 }
606 /*
607 * Copy IPv6 and ICMPv6 only.
608 */
609 nip6 = mtod(n, struct ip6_hdr *);
610 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
611 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
612 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
613 noff = sizeof(struct ip6_hdr);
614 /* new mbuf contains only ipv6+icmpv6 headers */
615 n->m_len = noff + sizeof(struct icmp6_hdr);
616 /*
617 * Adjust mbuf. ip6_plen will be adjusted in
618 * ip6_output().
619 */
620 m_adj(n0, off + sizeof(struct icmp6_hdr));
621 /* recalculate complete packet size */
622 n->m_pkthdr.len = n0len + (noff - off);
623 n->m_next = n0;
624 } else {
625 nip6 = mtod(n, struct ip6_hdr *);
626 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
627 sizeof(*nicmp6));
628 noff = off;
629 }
630 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
631 nicmp6->icmp6_code = 0;
632 if (n) {
633 ICMP6STAT_INC(icp6s_reflect);
634 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
635 icmp6_reflect(n, noff);
636 }
637 break;
638
639 case ICMP6_ECHO_REPLY:
640 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
641 if (code != 0)
642 goto badcode;
643 break;
644
645 case MLD_LISTENER_QUERY:
646 case MLD_LISTENER_REPORT:
647 case MLD_LISTENER_DONE:
648 case MLDV2_LISTENER_REPORT:
649 /*
650 * Drop MLD traffic which is not link-local, has a hop limit
651 * of greater than 1 hop, or which does not have the
652 * IPv6 HBH Router Alert option.
653 * As IPv6 HBH options are stripped in ip6_input() we must
654 * check an mbuf header flag.
655 * XXX Should we also sanity check that these messages
656 * were directed to a link-local multicast prefix?
657 */
658 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
659 goto freeit;
660 if (mld_input(m, off, icmp6len) != 0)
661 return (IPPROTO_DONE);
662 /* m stays. */
663 break;
664
665 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
666 {
667 enum { WRU, FQDN } mode;
668
669 if (!V_icmp6_nodeinfo)
670 break;
671
672 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
673 mode = WRU;
674 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
675 mode = FQDN;
676 else
677 goto badlen;
678
679 if (mode == FQDN) {
680#ifndef PULLDOWN_TEST
681 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
682 IPPROTO_DONE);
683#endif
684 n = m_copy(m, 0, M_COPYALL);
685 if (n)
686 n = ni6_input(n, off);
687 /* XXX meaningless if n == NULL */
688 noff = sizeof(struct ip6_hdr);
689 } else {
690 struct prison *pr;
691 u_char *p;
692 int maxlen, maxhlen, hlen;
693
694 /*
695 * XXX: this combination of flags is pointless,
696 * but should we keep this for compatibility?
697 */
698 if ((V_icmp6_nodeinfo & 5) != 5)
699 break;
700
701 if (code != 0)
702 goto badcode;
703 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
704 if (maxlen >= MCLBYTES) {
705 /* Give up remote */
706 break;
707 }
708 MGETHDR(n, M_DONTWAIT, m->m_type);
709 if (n && maxlen > MHLEN) {
710 MCLGET(n, M_DONTWAIT);
711 if ((n->m_flags & M_EXT) == 0) {
712 m_free(n);
713 n = NULL;
714 }
715 }
716 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
717 /*
718 * Previous code did a blind M_COPY_PKTHDR
719 * and said "just for rcvif". If true, then
720 * we could tolerate the dup failing (due to
721 * the deep copy of the tag chain). For now
722 * be conservative and just fail.
723 */
724 m_free(n);
725 n = NULL;
726 }
727 if (n == NULL) {
728 /* Give up remote */
729 break;
730 }
731 n->m_pkthdr.rcvif = NULL;
732 n->m_len = 0;
733 maxhlen = M_TRAILINGSPACE(n) - maxlen;
734 pr = curthread->td_ucred->cr_prison;
735 mtx_lock(&pr->pr_mtx);
736 hlen = strlen(pr->pr_hostname);
737 if (maxhlen > hlen)
738 maxhlen = hlen;
739 /*
740 * Copy IPv6 and ICMPv6 only.
741 */
742 nip6 = mtod(n, struct ip6_hdr *);
743 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
744 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
745 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
746 p = (u_char *)(nicmp6 + 1);
747 bzero(p, 4);
748 /* meaningless TTL */
749 bcopy(pr->pr_hostname, p + 4, maxhlen);
750 mtx_unlock(&pr->pr_mtx);
751 noff = sizeof(struct ip6_hdr);
752 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
753 sizeof(struct icmp6_hdr) + 4 + maxhlen;
754 nicmp6->icmp6_type = ICMP6_WRUREPLY;
755 nicmp6->icmp6_code = 0;
756 }
757 if (n) {
758 ICMP6STAT_INC(icp6s_reflect);
759 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
760 icmp6_reflect(n, noff);
761 }
762 break;
763 }
764
765 case ICMP6_WRUREPLY:
766 if (code != 0)
767 goto badcode;
768 break;
769
770 case ND_ROUTER_SOLICIT:
771 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
772 if (code != 0)
773 goto badcode;
774 if (icmp6len < sizeof(struct nd_router_solicit))
775 goto badlen;
776 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
777 /* give up local */
778 nd6_rs_input(m, off, icmp6len);
779 m = NULL;
780 goto freeit;
781 }
782 nd6_rs_input(n, off, icmp6len);
783 /* m stays. */
784 break;
785
786 case ND_ROUTER_ADVERT:
787 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
788 if (code != 0)
789 goto badcode;
790 if (icmp6len < sizeof(struct nd_router_advert))
791 goto badlen;
792 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
793 /* give up local */
794 nd6_ra_input(m, off, icmp6len);
795 m = NULL;
796 goto freeit;
797 }
798 nd6_ra_input(n, off, icmp6len);
799 /* m stays. */
800 break;
801
802 case ND_NEIGHBOR_SOLICIT:
803 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
804 if (code != 0)
805 goto badcode;
806 if (icmp6len < sizeof(struct nd_neighbor_solicit))
807 goto badlen;
808 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
809 /* give up local */
810 nd6_ns_input(m, off, icmp6len);
811 m = NULL;
812 goto freeit;
813 }
814 nd6_ns_input(n, off, icmp6len);
815 /* m stays. */
816 break;
817
818 case ND_NEIGHBOR_ADVERT:
819 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
820 if (code != 0)
821 goto badcode;
822 if (icmp6len < sizeof(struct nd_neighbor_advert))
823 goto badlen;
824 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
825 /* give up local */
826 nd6_na_input(m, off, icmp6len);
827 m = NULL;
828 goto freeit;
829 }
830 nd6_na_input(n, off, icmp6len);
831 /* m stays. */
832 break;
833
834 case ND_REDIRECT:
835 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
836 if (code != 0)
837 goto badcode;
838 if (icmp6len < sizeof(struct nd_redirect))
839 goto badlen;
840 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
841 /* give up local */
842 icmp6_redirect_input(m, off);
843 m = NULL;
844 goto freeit;
845 }
846 icmp6_redirect_input(n, off);
847 /* m stays. */
848 break;
849
850 case ICMP6_ROUTER_RENUMBERING:
851 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
852 code != ICMP6_ROUTER_RENUMBERING_RESULT)
853 goto badcode;
854 if (icmp6len < sizeof(struct icmp6_router_renum))
855 goto badlen;
856 break;
857
858 default:
859 nd6log((LOG_DEBUG,
860 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
861 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
862 ip6_sprintf(ip6bufd, &ip6->ip6_dst),
863 ifp ? ifp->if_index : 0));
864 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
865 /* ICMPv6 error: MUST deliver it by spec... */
866 code = PRC_NCMDS;
867 /* deliver */
868 } else {
869 /* ICMPv6 informational: MUST not deliver */
870 break;
871 }
872 deliver:
873 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
874 /* In this case, m should've been freed. */
875 return (IPPROTO_DONE);
876 }
877 break;
878
879 badcode:
880 ICMP6STAT_INC(icp6s_badcode);
881 break;
882
883 badlen:
884 ICMP6STAT_INC(icp6s_badlen);
885 break;
886 }
887
888 /* deliver the packet to appropriate sockets */
889 icmp6_rip6_input(&m, *offp);
890
891 return IPPROTO_DONE;
892
893 freeit:
894 m_freem(m);
895 return IPPROTO_DONE;
896}
897
898static int
899icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
900{
901 struct mbuf *m = *mp;
902 struct icmp6_hdr *icmp6;
903 struct ip6_hdr *eip6;
904 u_int32_t notifymtu;
905 struct sockaddr_in6 icmp6src, icmp6dst;
906
907 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
908 ICMP6STAT_INC(icp6s_tooshort);
909 goto freeit;
910 }
911#ifndef PULLDOWN_TEST
912 IP6_EXTHDR_CHECK(m, off,
913 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
914 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
915#else
916 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
917 sizeof(*icmp6) + sizeof(struct ip6_hdr));
918 if (icmp6 == NULL) {
919 ICMP6STAT_INC(icp6s_tooshort);
920 return (-1);
921 }
922#endif
923 eip6 = (struct ip6_hdr *)(icmp6 + 1);
924
925 /* Detect the upper level protocol */
926 {
927 void (*ctlfunc)(int, struct sockaddr *, void *);
928 u_int8_t nxt = eip6->ip6_nxt;
929 int eoff = off + sizeof(struct icmp6_hdr) +
930 sizeof(struct ip6_hdr);
931 struct ip6ctlparam ip6cp;
932 struct in6_addr *finaldst = NULL;
933 int icmp6type = icmp6->icmp6_type;
934 struct ip6_frag *fh;
935 struct ip6_rthdr *rth;
936 struct ip6_rthdr0 *rth0;
937 int rthlen;
938
939 while (1) { /* XXX: should avoid infinite loop explicitly? */
940 struct ip6_ext *eh;
941
942 switch (nxt) {
943 case IPPROTO_HOPOPTS:
944 case IPPROTO_DSTOPTS:
945 case IPPROTO_AH:
946#ifndef PULLDOWN_TEST
947 IP6_EXTHDR_CHECK(m, 0,
948 eoff + sizeof(struct ip6_ext), -1);
949 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
950#else
951 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
952 eoff, sizeof(*eh));
953 if (eh == NULL) {
954 ICMP6STAT_INC(icp6s_tooshort);
955 return (-1);
956 }
957#endif
958
959 if (nxt == IPPROTO_AH)
960 eoff += (eh->ip6e_len + 2) << 2;
961 else
962 eoff += (eh->ip6e_len + 1) << 3;
963 nxt = eh->ip6e_nxt;
964 break;
965 case IPPROTO_ROUTING:
966 /*
967 * When the erroneous packet contains a
968 * routing header, we should examine the
969 * header to determine the final destination.
970 * Otherwise, we can't properly update
971 * information that depends on the final
972 * destination (e.g. path MTU).
973 */
974#ifndef PULLDOWN_TEST
975 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
976 rth = (struct ip6_rthdr *)
977 (mtod(m, caddr_t) + eoff);
978#else
979 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
980 eoff, sizeof(*rth));
981 if (rth == NULL) {
982 ICMP6STAT_INC(icp6s_tooshort);
983 return (-1);
984 }
985#endif
986 rthlen = (rth->ip6r_len + 1) << 3;
987 /*
988 * XXX: currently there is no
989 * officially defined type other
990 * than type-0.
991 * Note that if the segment left field
992 * is 0, all intermediate hops must
993 * have been passed.
994 */
995 if (rth->ip6r_segleft &&
996 rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
997 int hops;
998
999#ifndef PULLDOWN_TEST
1000 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1001 rth0 = (struct ip6_rthdr0 *)
1002 (mtod(m, caddr_t) + eoff);
1003#else
1004 IP6_EXTHDR_GET(rth0,
1005 struct ip6_rthdr0 *, m,
1006 eoff, rthlen);
1007 if (rth0 == NULL) {
1008 ICMP6STAT_INC(icp6s_tooshort);
1009 return (-1);
1010 }
1011#endif
1012 /* just ignore a bogus header */
1013 if ((rth0->ip6r0_len % 2) == 0 &&
1014 (hops = rth0->ip6r0_len/2))
1015 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1016 }
1017 eoff += rthlen;
1018 nxt = rth->ip6r_nxt;
1019 break;
1020 case IPPROTO_FRAGMENT:
1021#ifndef PULLDOWN_TEST
1022 IP6_EXTHDR_CHECK(m, 0, eoff +
1023 sizeof(struct ip6_frag), -1);
1024 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1025 eoff);
1026#else
1027 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1028 eoff, sizeof(*fh));
1029 if (fh == NULL) {
1030 ICMP6STAT_INC(icp6s_tooshort);
1031 return (-1);
1032 }
1033#endif
1034 /*
1035 * Data after a fragment header is meaningless
1036 * unless it is the first fragment, but
1037 * we'll go to the notify label for path MTU
1038 * discovery.
1039 */
1040 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1041 goto notify;
1042
1043 eoff += sizeof(struct ip6_frag);
1044 nxt = fh->ip6f_nxt;
1045 break;
1046 default:
1047 /*
1048 * This case includes ESP and the No Next
1049 * Header. In such cases going to the notify
1050 * label does not have any meaning
1051 * (i.e. ctlfunc will be NULL), but we go
1052 * anyway since we might have to update
1053 * path MTU information.
1054 */
1055 goto notify;
1056 }
1057 }
1058 notify:
1059#ifndef PULLDOWN_TEST
1060 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1061#else
1062 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1063 sizeof(*icmp6) + sizeof(struct ip6_hdr));
1064 if (icmp6 == NULL) {
1065 ICMP6STAT_INC(icp6s_tooshort);
1066 return (-1);
1067 }
1068#endif
1069
1070 /*
1071 * retrieve parameters from the inner IPv6 header, and convert
1072 * them into sockaddr structures.
1073 * XXX: there is no guarantee that the source or destination
1074 * addresses of the inner packet are in the same scope as
1075 * the addresses of the icmp packet. But there is no other
1076 * way to determine the zone.
1077 */
1078 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1079
1080 bzero(&icmp6dst, sizeof(icmp6dst));
1081 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1082 icmp6dst.sin6_family = AF_INET6;
1083 if (finaldst == NULL)
1084 icmp6dst.sin6_addr = eip6->ip6_dst;
1085 else
1086 icmp6dst.sin6_addr = *finaldst;
1087 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1088 goto freeit;
1089 bzero(&icmp6src, sizeof(icmp6src));
1090 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1091 icmp6src.sin6_family = AF_INET6;
1092 icmp6src.sin6_addr = eip6->ip6_src;
1093 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1094 goto freeit;
1095 icmp6src.sin6_flowinfo =
1096 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1097
1098 if (finaldst == NULL)
1099 finaldst = &eip6->ip6_dst;
1100 ip6cp.ip6c_m = m;
1101 ip6cp.ip6c_icmp6 = icmp6;
1102 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1103 ip6cp.ip6c_off = eoff;
1104 ip6cp.ip6c_finaldst = finaldst;
1105 ip6cp.ip6c_src = &icmp6src;
1106 ip6cp.ip6c_nxt = nxt;
1107
1108 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1109 notifymtu = ntohl(icmp6->icmp6_mtu);
1110 ip6cp.ip6c_cmdarg = (void *)¬ifymtu;
1111 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
1112 }
1113
1114 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1115 (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1116 if (ctlfunc) {
1117 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1118 &ip6cp);
1119 }
1120 }
1121 *mp = m;
1122 return (0);
1123
1124 freeit:
1125 m_freem(m);
1126 return (-1);
1127}
1128
1129void
1130icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1131{
1132 struct in6_addr *dst = ip6cp->ip6c_finaldst;
1133 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1134 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1135 u_int mtu = ntohl(icmp6->icmp6_mtu);
1136 struct in_conninfo inc;
1137
1138#if 0
1139 /*
1140 * RFC2460 section 5, last paragraph.
1141 * even though minimum link MTU for IPv6 is IPV6_MMTU,
1142 * we may see ICMPv6 too big with mtu < IPV6_MMTU
1143 * due to packet translator in the middle.
1144 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1145 * special handling.
1146 */
1147 if (mtu < IPV6_MMTU)
1148 return;
1149#endif
1150
1151 /*
1152 * we reject ICMPv6 too big with abnormally small value.
1153 * XXX what is the good definition of "abnormally small"?
1154 */
1155 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1156 return;
1157
1158 if (!validated)
1159 return;
1160
1161 /*
1162 * In case the suggested mtu is less than IPV6_MMTU, we
1163 * only need to remember that it was for above mentioned
1164 * "alwaysfrag" case.
1165 * Try to be as close to the spec as possible.
1166 */
1167 if (mtu < IPV6_MMTU)
1168 mtu = IPV6_MMTU - 8;
1169
1170 bzero(&inc, sizeof(inc));
1171 inc.inc_flags |= INC_ISIPV6;
1172 inc.inc6_faddr = *dst;
1173 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1174 return;
1175
1176 if (mtu < tcp_maxmtu6(&inc, NULL)) {
1177 tcp_hc_updatemtu(&inc, mtu);
1178 ICMP6STAT_INC(icp6s_pmtuchg);
1179 }
1180}
1181
1182/*
1183 * Process a Node Information Query packet, based on
1184 * draft-ietf-ipngwg-icmp-name-lookups-07.
1185 *
1186 * Spec incompatibilities:
1187 * - IPv6 Subject address handling
1188 * - IPv4 Subject address handling support missing
1189 * - Proxy reply (answer even if it's not for me)
1190 * - joins NI group address at in6_ifattach() time only, does not cope
1191 * with hostname changes by sethostname(3)
1192 */
1193static struct mbuf *
1194ni6_input(struct mbuf *m, int off)
1195{
1196 struct icmp6_nodeinfo *ni6, *nni6;
1197 struct mbuf *n = NULL;
1198 struct prison *pr;
1199 u_int16_t qtype;
1200 int subjlen;
1201 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1202 struct ni_reply_fqdn *fqdn;
1203 int addrs; /* for NI_QTYPE_NODEADDR */
1204 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1205 struct in6_addr in6_subj; /* subject address */
1206 struct ip6_hdr *ip6;
1207 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
1208 char *subj = NULL;
1209 struct in6_ifaddr *ia6 = NULL;
1210
1211 ip6 = mtod(m, struct ip6_hdr *);
1212#ifndef PULLDOWN_TEST
1213 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1214#else
1215 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1216 if (ni6 == NULL) {
1217 /* m is already reclaimed */
1218 return (NULL);
1219 }
1220#endif
1221
1222 /*
1223 * Validate IPv6 source address.
1224 * The default configuration MUST be to refuse answering queries from
1225 * global-scope addresses according to RFC4602.
1226 * Notes:
1227 * - it's not very clear what "refuse" means; this implementation
1228 * simply drops it.
1229 * - it's not very easy to identify global-scope (unicast) addresses
1230 * since there are many prefixes for them. It should be safer
1231 * and in practice sufficient to check "all" but loopback and
1232 * link-local (note that site-local unicast was deprecated and
1233 * ULA is defined as global scope-wise)
1234 */
1235 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1236 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1237 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1238 goto bad;
1239
1240 /*
1241 * Validate IPv6 destination address.
1242 *
1243 * The Responder must discard the Query without further processing
1244 * unless it is one of the Responder's unicast or anycast addresses, or
1245 * a link-local scope multicast address which the Responder has joined.
1246 * [RFC4602, Section 5.]
1247 */
1248 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1249 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1250 goto bad;
1251 /* else it's a link-local multicast, fine */
1252 } else { /* unicast or anycast */
1253 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1254 goto bad; /* XXX impossible */
1255
1256 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1257 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1258 ifa_free(&ia6->ia_ifa);
1259 nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1260 "a temporary address in %s:%d",
1261 __FILE__, __LINE__));
1262 goto bad;
1263 }
1264 ifa_free(&ia6->ia_ifa);
1265 }
1266
1267 /* validate query Subject field. */
1268 qtype = ntohs(ni6->ni_qtype);
1269 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1270 switch (qtype) {
1271 case NI_QTYPE_NOOP:
1272 case NI_QTYPE_SUPTYPES:
1273 /* 07 draft */
1274 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1275 break;
1276 /* FALLTHROUGH */
1277 case NI_QTYPE_FQDN:
1278 case NI_QTYPE_NODEADDR:
1279 case NI_QTYPE_IPV4ADDR:
1280 switch (ni6->ni_code) {
1281 case ICMP6_NI_SUBJ_IPV6:
1282#if ICMP6_NI_SUBJ_IPV6 != 0
1283 case 0:
1284#endif
1285 /*
1286 * backward compatibility - try to accept 03 draft
1287 * format, where no Subject is present.
1288 */
1289 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1290 subjlen == 0) {
1291 oldfqdn++;
1292 break;
1293 }
1294#if ICMP6_NI_SUBJ_IPV6 != 0
1295 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1296 goto bad;
1297#endif
1298
1299 if (subjlen != sizeof(struct in6_addr))
1300 goto bad;
1301
1302 /*
1303 * Validate Subject address.
1304 *
1305 * Not sure what exactly "address belongs to the node"
1306 * means in the spec, is it just unicast, or what?
1307 *
1308 * At this moment we consider Subject address as
1309 * "belong to the node" if the Subject address equals
1310 * to the IPv6 destination address; validation for
1311 * IPv6 destination address should have done enough
1312 * check for us.
1313 *
1314 * We do not do proxy at this moment.
1315 */
1316 /* m_pulldown instead of copy? */
1317 m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1318 subjlen, (caddr_t)&in6_subj);
1319 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1320 goto bad;
1321
1322 subj = (char *)&in6_subj;
1323 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1324 break;
1325
1326 /*
1327 * XXX if we are to allow other cases, we should really
1328 * be careful about scope here.
1329 * basically, we should disallow queries toward IPv6
1330 * destination X with subject Y,
1331 * if scope(X) > scope(Y).
1332 * if we allow scope(X) > scope(Y), it will result in
1333 * information leakage across scope boundary.
1334 */
1335 goto bad;
1336
1337 case ICMP6_NI_SUBJ_FQDN:
1338 /*
1339 * Validate Subject name with gethostname(3).
1340 *
1341 * The behavior may need some debate, since:
1342 * - we are not sure if the node has FQDN as
1343 * hostname (returned by gethostname(3)).
1344 * - the code does wildcard match for truncated names.
1345 * however, we are not sure if we want to perform
1346 * wildcard match, if gethostname(3) side has
1347 * truncated hostname.
1348 */
1349 pr = curthread->td_ucred->cr_prison;
1350 mtx_lock(&pr->pr_mtx);
1351 n = ni6_nametodns(pr->pr_hostname,
1352 strlen(pr->pr_hostname), 0);
1353 mtx_unlock(&pr->pr_mtx);
1354 if (!n || n->m_next || n->m_len == 0)
1355 goto bad;
1356 IP6_EXTHDR_GET(subj, char *, m,
1357 off + sizeof(struct icmp6_nodeinfo), subjlen);
1358 if (subj == NULL)
1359 goto bad;
1360 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1361 n->m_len)) {
1362 goto bad;
1363 }
1364 m_freem(n);
1365 n = NULL;
1366 break;
1367
1368 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
1369 default:
1370 goto bad;
1371 }
1372 break;
1373 }
1374
1375 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
1376 switch (qtype) {
1377 case NI_QTYPE_FQDN:
1378 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1379 goto bad;
1380 break;
1381 case NI_QTYPE_NODEADDR:
1382 case NI_QTYPE_IPV4ADDR:
1383 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1384 goto bad;
1385 break;
1386 }
1387
1388 /* guess reply length */
1389 switch (qtype) {
1390 case NI_QTYPE_NOOP:
1391 break; /* no reply data */
1392 case NI_QTYPE_SUPTYPES:
1393 replylen += sizeof(u_int32_t);
1394 break;
1395 case NI_QTYPE_FQDN:
1396 /* XXX will append an mbuf */
1397 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1398 break;
1399 case NI_QTYPE_NODEADDR:
1400 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1401 if ((replylen += addrs * (sizeof(struct in6_addr) +
1402 sizeof(u_int32_t))) > MCLBYTES)
1403 replylen = MCLBYTES; /* XXX: will truncate pkt later */
1404 break;
1405 case NI_QTYPE_IPV4ADDR:
1406 /* unsupported - should respond with unknown Qtype? */
1407 break;
1408 default:
1409 /*
1410 * XXX: We must return a reply with the ICMP6 code
1411 * `unknown Qtype' in this case. However we regard the case
1412 * as an FQDN query for backward compatibility.
1413 * Older versions set a random value to this field,
1414 * so it rarely varies in the defined qtypes.
1415 * But the mechanism is not reliable...
1416 * maybe we should obsolete older versions.
1417 */
1418 qtype = NI_QTYPE_FQDN;
1419 /* XXX will append an mbuf */
1420 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1421 oldfqdn++;
1422 break;
1423 }
1424
1425 /* allocate an mbuf to reply. */
1426 MGETHDR(n, M_DONTWAIT, m->m_type);
1427 if (n == NULL) {
1428 m_freem(m);
1429 return (NULL);
1430 }
1431 M_MOVE_PKTHDR(n, m); /* just for recvif */
1432 if (replylen > MHLEN) {
1433 if (replylen > MCLBYTES) {
1434 /*
1435 * XXX: should we try to allocate more? But MCLBYTES
1436 * is probably much larger than IPV6_MMTU...
1437 */
1438 goto bad;
1439 }
1440 MCLGET(n, M_DONTWAIT);
1441 if ((n->m_flags & M_EXT) == 0) {
1442 goto bad;
1443 }
1444 }
1445 n->m_pkthdr.len = n->m_len = replylen;
1446
1447 /* copy mbuf header and IPv6 + Node Information base headers */
1448 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1449 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1450 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1451
1452 /* qtype dependent procedure */
1453 switch (qtype) {
1454 case NI_QTYPE_NOOP:
1455 nni6->ni_code = ICMP6_NI_SUCCESS;
1456 nni6->ni_flags = 0;
1457 break;
1458 case NI_QTYPE_SUPTYPES:
1459 {
1460 u_int32_t v;
1461 nni6->ni_code = ICMP6_NI_SUCCESS;
1462 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1463 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1464 v = (u_int32_t)htonl(0x0000000f);
1465 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1466 break;
1467 }
1468 case NI_QTYPE_FQDN:
1469 nni6->ni_code = ICMP6_NI_SUCCESS;
1470 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1471 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1472 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1473 fqdn->ni_fqdn_ttl = 0; /* ditto. */
1474 /*
1475 * XXX do we really have FQDN in hostname?
1476 */
1477 pr = curthread->td_ucred->cr_prison;
1478 mtx_lock(&pr->pr_mtx);
1479 n->m_next = ni6_nametodns(pr->pr_hostname,
1480 strlen(pr->pr_hostname), oldfqdn);
1481 mtx_unlock(&pr->pr_mtx);
1482 if (n->m_next == NULL)
1483 goto bad;
1484 /* XXX we assume that n->m_next is not a chain */
1485 if (n->m_next->m_next != NULL)
1486 goto bad;
1487 n->m_pkthdr.len += n->m_next->m_len;
1488 break;
1489 case NI_QTYPE_NODEADDR:
1490 {
1491 int lenlim, copied;
1492
1493 nni6->ni_code = ICMP6_NI_SUCCESS;
1494 n->m_pkthdr.len = n->m_len =
1495 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1496 lenlim = M_TRAILINGSPACE(n);
1497 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1498 /* XXX: reset mbuf length */
1499 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1500 sizeof(struct icmp6_nodeinfo) + copied;
1501 break;
1502 }
1503 default:
1504 break; /* XXX impossible! */
1505 }
1506
1507 nni6->ni_type = ICMP6_NI_REPLY;
1508 m_freem(m);
1509 return (n);
1510
1511 bad:
1512 m_freem(m);
1513 if (n)
1514 m_freem(n);
1515 return (NULL);
1516}
1517
1518/*
1519 * make a mbuf with DNS-encoded string. no compression support.
1520 *
1521 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1522 * treated as truncated name (two \0 at the end). this is a wild guess.
1523 *
1524 * old - return pascal string if non-zero
1525 */
1526static struct mbuf *
1527ni6_nametodns(const char *name, int namelen, int old)
1528{
1529 struct mbuf *m;
1530 char *cp, *ep;
1531 const char *p, *q;
1532 int i, len, nterm;
1533
1534 if (old)
1535 len = namelen + 1;
1536 else
1537 len = MCLBYTES;
1538
1539 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1540 MGET(m, M_DONTWAIT, MT_DATA);
1541 if (m && len > MLEN) {
1542 MCLGET(m, M_DONTWAIT);
1543 if ((m->m_flags & M_EXT) == 0)
1544 goto fail;
1545 }
1546 if (!m)
1547 goto fail;
1548 m->m_next = NULL;
1549
1550 if (old) {
1551 m->m_len = len;
1552 *mtod(m, char *) = namelen;
1553 bcopy(name, mtod(m, char *) + 1, namelen);
1554 return m;
1555 } else {
1556 m->m_len = 0;
1557 cp = mtod(m, char *);
1558 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1559
1560 /* if not certain about my name, return empty buffer */
1561 if (namelen == 0)
1562 return m;
1563
1564 /*
1565 * guess if it looks like shortened hostname, or FQDN.
1566 * shortened hostname needs two trailing "\0".
1567 */
1568 i = 0;
1569 for (p = name; p < name + namelen; p++) {
1570 if (*p && *p == '.')
1571 i++;
1572 }
1573 if (i < 2)
1574 nterm = 2;
1575 else
1576 nterm = 1;
1577
1578 p = name;
1579 while (cp < ep && p < name + namelen) {
1580 i = 0;
1581 for (q = p; q < name + namelen && *q && *q != '.'; q++)
1582 i++;
1583 /* result does not fit into mbuf */
1584 if (cp + i + 1 >= ep)
1585 goto fail;
1586 /*
1587 * DNS label length restriction, RFC1035 page 8.
1588 * "i == 0" case is included here to avoid returning
1589 * 0-length label on "foo..bar".
1590 */
1591 if (i <= 0 || i >= 64)
1592 goto fail;
1593 *cp++ = i;
1594 bcopy(p, cp, i);
1595 cp += i;
1596 p = q;
1597 if (p < name + namelen && *p == '.')
1598 p++;
1599 }
1600 /* termination */
1601 if (cp + nterm >= ep)
1602 goto fail;
1603 while (nterm-- > 0)
1604 *cp++ = '\0';
1605 m->m_len = cp - mtod(m, char *);
1606 return m;
1607 }
1608
1609 panic("should not reach here");
1610 /* NOTREACHED */
1611
1612 fail:
1613 if (m)
1614 m_freem(m);
1615 return NULL;
1616}
1617
1618/*
1619 * check if two DNS-encoded string matches. takes care of truncated
1620 * form (with \0\0 at the end). no compression support.
1621 * XXX upper/lowercase match (see RFC2065)
1622 */
1623static int
1624ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1625{
1626 const char *a0, *b0;
1627 int l;
1628
1629 /* simplest case - need validation? */
1630 if (alen == blen && bcmp(a, b, alen) == 0)
1631 return 1;
1632
1633 a0 = a;
1634 b0 = b;
1635
1636 /* termination is mandatory */
1637 if (alen < 2 || blen < 2)
1638 return 0;
1639 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1640 return 0;
1641 alen--;
1642 blen--;
1643
1644 while (a - a0 < alen && b - b0 < blen) {
1645 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1646 return 0;
1647
1648 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1649 return 0;
1650 /* we don't support compression yet */
1651 if (a[0] >= 64 || b[0] >= 64)
1652 return 0;
1653
1654 /* truncated case */
1655 if (a[0] == 0 && a - a0 == alen - 1)
1656 return 1;
1657 if (b[0] == 0 && b - b0 == blen - 1)
1658 return 1;
1659 if (a[0] == 0 || b[0] == 0)
1660 return 0;
1661
1662 if (a[0] != b[0])
1663 return 0;
1664 l = a[0];
1665 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1666 return 0;
1667 if (bcmp(a + 1, b + 1, l) != 0)
1668 return 0;
1669
1670 a += 1 + l;
1671 b += 1 + l;
1672 }
1673
1674 if (a - a0 == alen && b - b0 == blen)
1675 return 1;
1676 else
1677 return 0;
1678}
1679
1680/*
1681 * calculate the number of addresses to be returned in the node info reply.
1682 */
1683static int
1684ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1685 struct in6_addr *subj)
1686{
1687 struct ifnet *ifp;
1688 struct in6_ifaddr *ifa6;
1689 struct ifaddr *ifa;
1690 int addrs = 0, addrsofif, iffound = 0;
1691 int niflags = ni6->ni_flags;
1692
1693 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1694 switch (ni6->ni_code) {
1695 case ICMP6_NI_SUBJ_IPV6:
1696 if (subj == NULL) /* must be impossible... */
1697 return (0);
1698 break;
1699 default:
1700 /*
1701 * XXX: we only support IPv6 subject address for
1702 * this Qtype.
1703 */
1704 return (0);
1705 }
1706 }
1707
1708 IFNET_RLOCK_NOSLEEP();
1709 for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1710 addrsofif = 0;
1711 IF_ADDR_LOCK(ifp);
1712 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1713 if (ifa->ifa_addr->sa_family != AF_INET6)
1714 continue;
1715 ifa6 = (struct in6_ifaddr *)ifa;
1716
1717 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1718 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1719 iffound = 1;
1720
1721 /*
1722 * IPv4-mapped addresses can only be returned by a
1723 * Node Information proxy, since they represent
1724 * addresses of IPv4-only nodes, which perforce do
1725 * not implement this protocol.
1726 * [icmp-name-lookups-07, Section 5.4]
1727 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1728 * this function at this moment.
1729 */
1730
1731 /* What do we have to do about ::1? */
1732 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1733 case IPV6_ADDR_SCOPE_LINKLOCAL:
1734 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1735 continue;
1736 break;
1737 case IPV6_ADDR_SCOPE_SITELOCAL:
1738 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1739 continue;
1740 break;
1741 case IPV6_ADDR_SCOPE_GLOBAL:
1742 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1743 continue;
1744 break;
1745 default:
1746 continue;
1747 }
1748
1749 /*
1750 * check if anycast is okay.
1751 * XXX: just experimental. not in the spec.
1752 */
1753 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1754 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1755 continue; /* we need only unicast addresses */
1756 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1757 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1758 continue;
1759 }
1760 addrsofif++; /* count the address */
1761 }
1762 IF_ADDR_UNLOCK(ifp);
1763 if (iffound) {
1764 *ifpp = ifp;
1765 IFNET_RUNLOCK_NOSLEEP();
1766 return (addrsofif);
1767 }
1768
1769 addrs += addrsofif;
1770 }
1771 IFNET_RUNLOCK_NOSLEEP();
1772
1773 return (addrs);
1774}
1775
1776static int
1777ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1778 struct ifnet *ifp0, int resid)
1779{
1780 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1781 struct in6_ifaddr *ifa6;
1782 struct ifaddr *ifa;
1783 struct ifnet *ifp_dep = NULL;
1784 int copied = 0, allow_deprecated = 0;
1785 u_char *cp = (u_char *)(nni6 + 1);
1786 int niflags = ni6->ni_flags;
1787 u_int32_t ltime;
1788
1789 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1790 return (0); /* needless to copy */
1791
1792 IFNET_RLOCK_NOSLEEP();
1793 again:
1794
1795 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1796 IF_ADDR_LOCK(ifp);
1797 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1798 if (ifa->ifa_addr->sa_family != AF_INET6)
1799 continue;
1800 ifa6 = (struct in6_ifaddr *)ifa;
1801
1802 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1803 allow_deprecated == 0) {
1804 /*
1805 * prefererred address should be put before
1806 * deprecated addresses.
1807 */
1808
1809 /* record the interface for later search */
1810 if (ifp_dep == NULL)
1811 ifp_dep = ifp;
1812
1813 continue;
1814 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1815 allow_deprecated != 0)
1816 continue; /* we now collect deprecated addrs */
1817
1818 /* What do we have to do about ::1? */
1819 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1820 case IPV6_ADDR_SCOPE_LINKLOCAL:
1821 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1822 continue;
1823 break;
1824 case IPV6_ADDR_SCOPE_SITELOCAL:
1825 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1826 continue;
1827 break;
1828 case IPV6_ADDR_SCOPE_GLOBAL:
1829 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1830 continue;
1831 break;
1832 default:
1833 continue;
1834 }
1835
1836 /*
1837 * check if anycast is okay.
1838 * XXX: just experimental. not in the spec.
1839 */
1840 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1841 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1842 continue;
1843 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1844 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1845 continue;
1846 }
1847
1848 /* now we can copy the address */
1849 if (resid < sizeof(struct in6_addr) +
1850 sizeof(u_int32_t)) {
1851 IF_ADDR_UNLOCK(ifp);
1852 /*
1853 * We give up much more copy.
1854 * Set the truncate flag and return.
1855 */
1856 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1857 IFNET_RUNLOCK_NOSLEEP();
1858 return (copied);
1859 }
1860
1861 /*
1862 * Set the TTL of the address.
1863 * The TTL value should be one of the following
1864 * according to the specification:
1865 *
1866 * 1. The remaining lifetime of a DHCP lease on the
1867 * address, or
1868 * 2. The remaining Valid Lifetime of a prefix from
1869 * which the address was derived through Stateless
1870 * Autoconfiguration.
1871 *
1872 * Note that we currently do not support stateful
1873 * address configuration by DHCPv6, so the former
1874 * case can't happen.
1875 */
1876 if (ifa6->ia6_lifetime.ia6t_expire == 0)
1877 ltime = ND6_INFINITE_LIFETIME;
1878 else {
1879 if (ifa6->ia6_lifetime.ia6t_expire >
1880 time_second)
1881 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1882 else
1883 ltime = 0;
1884 }
1885
1886 bcopy(<ime, cp, sizeof(u_int32_t));
1887 cp += sizeof(u_int32_t);
1888
1889 /* copy the address itself */
1890 bcopy(&ifa6->ia_addr.sin6_addr, cp,
1891 sizeof(struct in6_addr));
1892 in6_clearscope((struct in6_addr *)cp); /* XXX */
1893 cp += sizeof(struct in6_addr);
1894
1895 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1896 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1897 }
1898 IF_ADDR_UNLOCK(ifp);
1899 if (ifp0) /* we need search only on the specified IF */
1900 break;
1901 }
1902
1903 if (allow_deprecated == 0 && ifp_dep != NULL) {
1904 ifp = ifp_dep;
1905 allow_deprecated = 1;
1906
1907 goto again;
1908 }
1909
1910 IFNET_RUNLOCK_NOSLEEP();
1911
1912 return (copied);
1913}
1914
1915/*
1916 * XXX almost dup'ed code with rip6_input.
1917 */
1918static int
1919icmp6_rip6_input(struct mbuf **mp, int off)
1920{
1921 struct mbuf *m = *mp;
1922 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1923 struct inpcb *in6p;
1924 struct inpcb *last = NULL;
1925 struct sockaddr_in6 fromsa;
1926 struct icmp6_hdr *icmp6;
1927 struct mbuf *opts = NULL;
1928
1929#ifndef PULLDOWN_TEST
1930 /* this is assumed to be safe. */
1931 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1932#else
1933 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1934 if (icmp6 == NULL) {
1935 /* m is already reclaimed */
1936 return (IPPROTO_DONE);
1937 }
1938#endif
1939
1940 /*
1941 * XXX: the address may have embedded scope zone ID, which should be
1942 * hidden from applications.
1943 */
1944 bzero(&fromsa, sizeof(fromsa));
1945 fromsa.sin6_family = AF_INET6;
1946 fromsa.sin6_len = sizeof(struct sockaddr_in6);
1947 fromsa.sin6_addr = ip6->ip6_src;
1948 if (sa6_recoverscope(&fromsa)) {
1949 m_freem(m);
1950 return (IPPROTO_DONE);
1951 }
1952
1953 INP_INFO_RLOCK(&V_ripcbinfo);
1954 LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1955 if ((in6p->inp_vflag & INP_IPV6) == 0)
1956 continue;
1957 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1958 continue;
1959 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1960 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1961 continue;
1962 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1963 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1964 continue;
1965 INP_RLOCK(in6p);
1966 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1967 in6p->in6p_icmp6filt)) {
1968 INP_RUNLOCK(in6p);
1969 continue;
1970 }
1971 if (last != NULL) {
1972 struct mbuf *n = NULL;
1973
1974 /*
1975 * Recent network drivers tend to allocate a single
1976 * mbuf cluster, rather than to make a couple of
1977 * mbufs without clusters. Also, since the IPv6 code
1978 * path tries to avoid m_pullup(), it is highly
1979 * probable that we still have an mbuf cluster here
1980 * even though the necessary length can be stored in an
1981 * mbuf's internal buffer.
1982 * Meanwhile, the default size of the receive socket
1983 * buffer for raw sockets is not so large. This means
1984 * the possibility of packet loss is relatively higher
1985 * than before. To avoid this scenario, we copy the
1986 * received data to a separate mbuf that does not use
1987 * a cluster, if possible.
1988 * XXX: it is better to copy the data after stripping
1989 * intermediate headers.
1990 */
1991 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1992 m->m_len <= MHLEN) {
1993 MGET(n, M_DONTWAIT, m->m_type);
1994 if (n != NULL) {
1995 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1996 bcopy(m->m_data, n->m_data,
1997 m->m_len);
1998 n->m_len = m->m_len;
1999 } else {
2000 m_free(n);
2001 n = NULL;
2002 }
2003 }
2004 }
2005 if (n != NULL ||
2006 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
2007 if (last->inp_flags & INP_CONTROLOPTS)
2008 ip6_savecontrol(last, n, &opts);
2009 /* strip intermediate headers */
2010 m_adj(n, off);
2011 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2012 if (sbappendaddr_locked(
2013 &last->inp_socket->so_rcv,
2014 (struct sockaddr *)&fromsa, n, opts)
2015 == 0) {
2016 /* should notify about lost packet */
2017 m_freem(n);
2018 if (opts) {
2019 m_freem(opts);
2020 }
2021 SOCKBUF_UNLOCK(
2022 &last->inp_socket->so_rcv);
2023 } else
2024 sorwakeup_locked(last->inp_socket);
2025 opts = NULL;
2026 }
2027 INP_RUNLOCK(last);
2028 }
2029 last = in6p;
2030 }
2031 INP_INFO_RUNLOCK(&V_ripcbinfo);
2032 if (last != NULL) {
2033 if (last->inp_flags & INP_CONTROLOPTS)
2034 ip6_savecontrol(last, m, &opts);
2035 /* strip intermediate headers */
2036 m_adj(m, off);
2037
2038 /* avoid using mbuf clusters if possible (see above) */
2039 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2040 m->m_len <= MHLEN) {
2041 struct mbuf *n;
2042
2043 MGET(n, M_DONTWAIT, m->m_type);
2044 if (n != NULL) {
2045 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2046 bcopy(m->m_data, n->m_data, m->m_len);
2047 n->m_len = m->m_len;
2048
2049 m_freem(m);
2050 m = n;
2051 } else {
2052 m_freem(n);
2053 n = NULL;
2054 }
2055 }
2056 }
2057 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2058 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2059 (struct sockaddr *)&fromsa, m, opts) == 0) {
2060 m_freem(m);
2061 if (opts)
2062 m_freem(opts);
2063 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2064 } else
2065 sorwakeup_locked(last->inp_socket);
2066 INP_RUNLOCK(last);
2067 } else {
2068 m_freem(m);
2069 IP6STAT_DEC(ip6s_delivered);
2070 }
2071 return IPPROTO_DONE;
2072}
2073
2074/*
2075 * Reflect the ip6 packet back to the source.
2076 * OFF points to the icmp6 header, counted from the top of the mbuf.
2077 */
2078void
2079icmp6_reflect(struct mbuf *m, size_t off)
2080{
2081 struct ip6_hdr *ip6;
2082 struct icmp6_hdr *icmp6;
2083 struct in6_ifaddr *ia = NULL;
2084 int plen;
2085 int type, code;
2086 struct ifnet *outif = NULL;
2087 struct in6_addr origdst, src, *srcp = NULL;
2088
2089 /* too short to reflect */
2090 if (off < sizeof(struct ip6_hdr)) {
2091 nd6log((LOG_DEBUG,
2092 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2093 (u_long)off, (u_long)sizeof(struct ip6_hdr),
2094 __FILE__, __LINE__));
2095 goto bad;
2096 }
2097
2098 /*
2099 * If there are extra headers between IPv6 and ICMPv6, strip
2100 * off that header first.
2101 */
2102#ifdef DIAGNOSTIC
2103 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2104 panic("assumption failed in icmp6_reflect");
2105#endif
2106 if (off > sizeof(struct ip6_hdr)) {
2107 size_t l;
2108 struct ip6_hdr nip6;
2109
2110 l = off - sizeof(struct ip6_hdr);
2111 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2112 m_adj(m, l);
2113 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2114 if (m->m_len < l) {
2115 if ((m = m_pullup(m, l)) == NULL)
2116 return;
2117 }
2118 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2119 } else /* off == sizeof(struct ip6_hdr) */ {
2120 size_t l;
2121 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2122 if (m->m_len < l) {
2123 if ((m = m_pullup(m, l)) == NULL)
2124 return;
2125 }
2126 }
2127 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2128 ip6 = mtod(m, struct ip6_hdr *);
2129 ip6->ip6_nxt = IPPROTO_ICMPV6;
2130 icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2131 type = icmp6->icmp6_type; /* keep type for statistics */
2132 code = icmp6->icmp6_code; /* ditto. */
2133
2134 origdst = ip6->ip6_dst;
2135 /*
2136 * ip6_input() drops a packet if its src is multicast.
2137 * So, the src is never multicast.
2138 */
2139 ip6->ip6_dst = ip6->ip6_src;
2140
2141 /*
2142 * If the incoming packet was addressed directly to us (i.e. unicast),
2143 * use dst as the src for the reply.
2144 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2145 * (for example) when we encounter an error while forwarding procedure
2146 * destined to a duplicated address of ours.
2147 * Note that ip6_getdstifaddr() may fail if we are in an error handling
2148 * procedure of an outgoing packet of our own, in which case we need
2149 * to search in the ifaddr list.
2150 */
2151 if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2152 if ((ia = ip6_getdstifaddr(m))) {
2153 if (!(ia->ia6_flags &
2154 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2155 srcp = &ia->ia_addr.sin6_addr;
2156 } else {
2157 struct sockaddr_in6 d;
2158
2159 bzero(&d, sizeof(d));
2160 d.sin6_family = AF_INET6;
2161 d.sin6_len = sizeof(d);
2162 d.sin6_addr = origdst;
2163 ia = (struct in6_ifaddr *)
2164 ifa_ifwithaddr((struct sockaddr *)&d);
2165 if (ia &&
2166 !(ia->ia6_flags &
2167 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2168 srcp = &ia->ia_addr.sin6_addr;
2169 }
2170 }
2171 }
2172
2173 if ((srcp != NULL) &&
2174 (in6_addrscope(srcp) != in6_addrscope(&ip6->ip6_src)))
2175 srcp = NULL;
2176
2177 if (srcp == NULL) {
2178 int e;
2179 struct sockaddr_in6 sin6;
2180 struct route_in6 ro;
2181
2182 /*
2183 * This case matches to multicasts, our anycast, or unicasts
2184 * that we do not own. Select a source address based on the
2185 * source address of the erroneous packet.
2186 */
2187 bzero(&sin6, sizeof(sin6));
2188 sin6.sin6_family = AF_INET6;
2189 sin6.sin6_len = sizeof(sin6);
2190 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2191
2192 bzero(&ro, sizeof(ro));
2193 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
2194 if (ro.ro_rt)
2195 RTFREE(ro.ro_rt); /* XXX: we could use this */
2196 if (e) {
2197 char ip6buf[INET6_ADDRSTRLEN];
2198 nd6log((LOG_DEBUG,
2199 "icmp6_reflect: source can't be determined: "
2200 "dst=%s, error=%d\n",
2201 ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2202 goto bad;
2203 }
2204 srcp = &src;
2205 }
2206
2207 ip6->ip6_src = *srcp;
2208 ip6->ip6_flow = 0;
2209 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2210 ip6->ip6_vfc |= IPV6_VERSION;
2211 ip6->ip6_nxt = IPPROTO_ICMPV6;
2212 if (outif)
2213 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2214 else if (m->m_pkthdr.rcvif) {
2215 /* XXX: This may not be the outgoing interface */
2216 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2217 } else
2218 ip6->ip6_hlim = V_ip6_defhlim;
2219
2220 icmp6->icmp6_cksum = 0;
2221 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2222 sizeof(struct ip6_hdr), plen);
2223
2224 /*
2225 * XXX option handling
2226 */
2227
2228 m->m_flags &= ~(M_BCAST|M_MCAST);
2229
2230 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2231 if (outif)
2232 icmp6_ifoutstat_inc(outif, type, code);
2233
2234 if (ia != NULL)
2235 ifa_free(&ia->ia_ifa);
2236 return;
2237
2238 bad:
2239 if (ia != NULL)
2240 ifa_free(&ia->ia_ifa);
2241 m_freem(m);
2242 return;
2243}
2244
2245void
2246icmp6_fasttimo(void)
2247{
2248
2249 mld_fasttimo();
2250}
2251
2252void
2253icmp6_slowtimo(void)
2254{
2255
2256 mld_slowtimo();
2257}
2258
2259static const char *
2260icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2261 struct in6_addr *tgt6)
2262{
2263 static char buf[1024];
2264 char ip6bufs[INET6_ADDRSTRLEN];
2265 char ip6bufd[INET6_ADDRSTRLEN];
2266 char ip6buft[INET6_ADDRSTRLEN];
2267 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2268 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2269 ip6_sprintf(ip6buft, tgt6));
2270 return buf;
2271}
2272
2273void
2274icmp6_redirect_input(struct mbuf *m, int off)
2275{
2276 struct ifnet *ifp;
2277 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2278 struct nd_redirect *nd_rd;
2279 int icmp6len = ntohs(ip6->ip6_plen);
2280 char *lladdr = NULL;
2281 int lladdrlen = 0;
2282 u_char *redirhdr = NULL;
2283 int redirhdrlen = 0;
2284 struct rtentry *rt = NULL;
2285 int is_router;
2286 int is_onlink;
2287 struct in6_addr src6 = ip6->ip6_src;
2288 struct in6_addr redtgt6;
2289 struct in6_addr reddst6;
2290 union nd_opts ndopts;
2291 char ip6buf[INET6_ADDRSTRLEN];
2292
2293 if (!m)
2294 return;
2295
2296 ifp = m->m_pkthdr.rcvif;
2297
2298 if (!ifp)
2299 return;
2300
2301 /* XXX if we are router, we don't update route by icmp6 redirect */
2302 if (V_ip6_forwarding)
2303 goto freeit;
2304 if (!V_icmp6_rediraccept)
2305 goto freeit;
2306
2307#ifndef PULLDOWN_TEST
2308 IP6_EXTHDR_CHECK(m, off, icmp6len,);
2309 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2310#else
2311 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2312 if (nd_rd == NULL) {
2313 ICMP6STAT_INC(icp6s_tooshort);
2314 return;
2315 }
2316#endif
2317 redtgt6 = nd_rd->nd_rd_target;
2318 reddst6 = nd_rd->nd_rd_dst;
2319
2320 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2321 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2322 goto freeit;
2323 }
2324
2325 /* validation */
2326 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2327 nd6log((LOG_ERR,
2328 "ICMP6 redirect sent from %s rejected; "
2329 "must be from linklocal\n",
2330 ip6_sprintf(ip6buf, &src6)));
2331 goto bad;
2332 }
2333 if (ip6->ip6_hlim != 255) {
2334 nd6log((LOG_ERR,
2335 "ICMP6 redirect sent from %s rejected; "
2336 "hlim=%d (must be 255)\n",
2337 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2338 goto bad;
2339 }
2340 {
2341 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2342 struct sockaddr_in6 sin6;
2343 struct in6_addr *gw6;
2344
2345 bzero(&sin6, sizeof(sin6));
2346 sin6.sin6_family = AF_INET6;
2347 sin6.sin6_len = sizeof(struct sockaddr_in6);
2348 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2349 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2350 if (rt) {
2351 if (rt->rt_gateway == NULL ||
2352 rt->rt_gateway->sa_family != AF_INET6) {
2353 nd6log((LOG_ERR,
2354 "ICMP6 redirect rejected; no route "
2355 "with inet6 gateway found for redirect dst: %s\n",
2356 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2357 RTFREE_LOCKED(rt);
2358 goto bad;
2359 }
2360
2361 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2362 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2363 nd6log((LOG_ERR,
2364 "ICMP6 redirect rejected; "
2365 "not equal to gw-for-src=%s (must be same): "
2366 "%s\n",
2367 ip6_sprintf(ip6buf, gw6),
2368 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2369 RTFREE_LOCKED(rt);
2370 goto bad;
2371 }
2372 } else {
2373 nd6log((LOG_ERR,
2374 "ICMP6 redirect rejected; "
2375 "no route found for redirect dst: %s\n",
2376 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2377 goto bad;
2378 }
2379 RTFREE_LOCKED(rt);
2380 rt = NULL;
2381 }
2382 if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2383 nd6log((LOG_ERR,
2384 "ICMP6 redirect rejected; "
2385 "redirect dst must be unicast: %s\n",
2386 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2387 goto bad;
2388 }
2389
2390 is_router = is_onlink = 0;
2391 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2392 is_router = 1; /* router case */
2393 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2394 is_onlink = 1; /* on-link destination case */
2395 if (!is_router && !is_onlink) {
2396 nd6log((LOG_ERR,
2397 "ICMP6 redirect rejected; "
2398 "neither router case nor onlink case: %s\n",
2399 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2400 goto bad;
2401 }
2402 /* validation passed */
2403
2404 icmp6len -= sizeof(*nd_rd);
2405 nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2406 if (nd6_options(&ndopts) < 0) {
2407 nd6log((LOG_INFO, "icmp6_redirect_input: "
2408 "invalid ND option, rejected: %s\n",
2409 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2410 /* nd6_options have incremented stats */
2411 goto freeit;
2412 }
2413
2414 if (ndopts.nd_opts_tgt_lladdr) {
2415 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2416 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2417 }
2418
2419 if (ndopts.nd_opts_rh) {
2420 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2421 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2422 }
2423
2424 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2425 nd6log((LOG_INFO,
2426 "icmp6_redirect_input: lladdrlen mismatch for %s "
2427 "(if %d, icmp6 packet %d): %s\n",
2428 ip6_sprintf(ip6buf, &redtgt6),
2429 ifp->if_addrlen, lladdrlen - 2,
2430 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2431 goto bad;
2432 }
2433
2434 /* RFC 2461 8.3 */
2435 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2436 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2437
2438 if (!is_onlink) { /* better router case. perform rtredirect. */
2439 /* perform rtredirect */
2440 struct sockaddr_in6 sdst;
2441 struct sockaddr_in6 sgw;
2442 struct sockaddr_in6 ssrc;
2443
2444 bzero(&sdst, sizeof(sdst));
2445 bzero(&sgw, sizeof(sgw));
2446 bzero(&ssrc, sizeof(ssrc));
2447 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2448 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2449 sizeof(struct sockaddr_in6);
2450 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2451 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2452 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2453 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2454 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2455 (struct sockaddr *)&ssrc);
2456 }
2457 /* finally update cached route in each socket via pfctlinput */
2458 {
2459 struct sockaddr_in6 sdst;
2460
2461 bzero(&sdst, sizeof(sdst));
2462 sdst.sin6_family = AF_INET6;
2463 sdst.sin6_len = sizeof(struct sockaddr_in6);
2464 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2465 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2466#ifdef IPSEC
2467 key_sa_routechange((struct sockaddr *)&sdst);
2468#endif /* IPSEC */
2469 }
2470
2471 freeit:
2472 m_freem(m);
2473 return;
2474
2475 bad:
2476 ICMP6STAT_INC(icp6s_badredirect);
2477 m_freem(m);
2478}
2479
2480void
2481icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2482{
2483 struct ifnet *ifp; /* my outgoing interface */
2484 struct in6_addr *ifp_ll6;
2485 struct in6_addr *router_ll6;
2486 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
2487 struct mbuf *m = NULL; /* newly allocated one */
2488 struct ip6_hdr *ip6; /* m as struct ip6_hdr */
2489 struct nd_redirect *nd_rd;
2490 struct llentry *ln = NULL;
2491 size_t maxlen;
2492 u_char *p;
2493 struct ifnet *outif = NULL;
2494 struct sockaddr_in6 src_sa;
2495
2496 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2497
2498 /* if we are not router, we don't send icmp6 redirect */
2499 if (!V_ip6_forwarding)
2500 goto fail;
2501
2502 /* sanity check */
2503 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2504 goto fail;
2505
2506 /*
2507 * Address check:
2508 * the source address must identify a neighbor, and
2509 * the destination address must not be a multicast address
2510 * [RFC 2461, sec 8.2]
2511 */
2512 sip6 = mtod(m0, struct ip6_hdr *);
2513 bzero(&src_sa, sizeof(src_sa));
2514 src_sa.sin6_family = AF_INET6;
2515 src_sa.sin6_len = sizeof(src_sa);
2516 src_sa.sin6_addr = sip6->ip6_src;
2517 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2518 goto fail;
2519 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2520 goto fail; /* what should we do here? */
2521
2522 /* rate limit */
2523 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2524 goto fail;
2525
2526 /*
2527 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2528 * we almost always ask for an mbuf cluster for simplicity.
2529 * (MHLEN < IPV6_MMTU is almost always true)
2530 */
2531#if IPV6_MMTU >= MCLBYTES
2532# error assumption failed about IPV6_MMTU and MCLBYTES
2533#endif
2534 MGETHDR(m, M_DONTWAIT, MT_HEADER);
2535 if (m && IPV6_MMTU >= MHLEN)
2536 MCLGET(m, M_DONTWAIT);
2537 if (!m)
2538 goto fail;
2539 m->m_pkthdr.rcvif = NULL;
2540 m->m_len = 0;
2541 maxlen = M_TRAILINGSPACE(m);
2542 maxlen = min(IPV6_MMTU, maxlen);
2543 /* just for safety */
2544 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2545 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2546 goto fail;
2547 }
2548
2549 {
2550 /* get ip6 linklocal address for ifp(my outgoing interface). */
2551 struct in6_ifaddr *ia;
2552 if ((ia = in6ifa_ifpforlinklocal(ifp,
2553 IN6_IFF_NOTREADY|
2554 IN6_IFF_ANYCAST)) == NULL)
2555 goto fail;
2556 ifp_ll6 = &ia->ia_addr.sin6_addr;
2557 /* XXXRW: reference released prematurely. */
2558 ifa_free(&ia->ia_ifa);
2559 }
2560
2561 /* get ip6 linklocal address for the router. */
2562 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2563 struct sockaddr_in6 *sin6;
2564 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2565 router_ll6 = &sin6->sin6_addr;
2566 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2567 router_ll6 = (struct in6_addr *)NULL;
2568 } else
2569 router_ll6 = (struct in6_addr *)NULL;
2570
2571 /* ip6 */
2572 ip6 = mtod(m, struct ip6_hdr *);
2573 ip6->ip6_flow = 0;
2574 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2575 ip6->ip6_vfc |= IPV6_VERSION;
2576 /* ip6->ip6_plen will be set later */
2577 ip6->ip6_nxt = IPPROTO_ICMPV6;
2578 ip6->ip6_hlim = 255;
2579 /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2580 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2581 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2582
2583 /* ND Redirect */
2584 nd_rd = (struct nd_redirect *)(ip6 + 1);
2585 nd_rd->nd_rd_type = ND_REDIRECT;
2586 nd_rd->nd_rd_code = 0;
2587 nd_rd->nd_rd_reserved = 0;
2588 if (rt->rt_flags & RTF_GATEWAY) {
2589 /*
2590 * nd_rd->nd_rd_target must be a link-local address in
2591 * better router cases.
2592 */
2593 if (!router_ll6)
2594 goto fail;
2595 bcopy(router_ll6, &nd_rd->nd_rd_target,
2596 sizeof(nd_rd->nd_rd_target));
2597 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2598 sizeof(nd_rd->nd_rd_dst));
2599 } else {
2600 /* make sure redtgt == reddst */
2601 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2602 sizeof(nd_rd->nd_rd_target));
2603 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2604 sizeof(nd_rd->nd_rd_dst));
2605 }
2606
2607 p = (u_char *)(nd_rd + 1);
2608
2609 if (!router_ll6)
2610 goto nolladdropt;
2611
2612 {
2613 /* target lladdr option */
2614 int len;
2615 struct nd_opt_hdr *nd_opt;
2616 char *lladdr;
2617
2618 IF_AFDATA_LOCK(ifp);
2619 ln = nd6_lookup(router_ll6, 0, ifp);
2620 IF_AFDATA_UNLOCK(ifp);
2621 if (ln == NULL)
2622 goto nolladdropt;
2623
2624 len = sizeof(*nd_opt) + ifp->if_addrlen;
2625 len = (len + 7) & ~7; /* round by 8 */
2626 /* safety check */
2627 if (len + (p - (u_char *)ip6) > maxlen)
2628 goto nolladdropt;
2629
2630 if (ln->la_flags & LLE_VALID) {
2631 nd_opt = (struct nd_opt_hdr *)p;
2632 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2633 nd_opt->nd_opt_len = len >> 3;
2634 lladdr = (char *)(nd_opt + 1);
2635 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2636 p += len;
2637 }
2638 }
2639nolladdropt:
2640 if (ln != NULL)
2641 LLE_RUNLOCK(ln);
2642
2643 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2644
2645 /* just to be safe */
2646#ifdef M_DECRYPTED /*not openbsd*/
2647 if (m0->m_flags & M_DECRYPTED)
2648 goto noredhdropt;
2649#endif
2650 if (p - (u_char *)ip6 > maxlen)
2651 goto noredhdropt;
2652
2653 {
2654 /* redirected header option */
2655 int len;
2656 struct nd_opt_rd_hdr *nd_opt_rh;
2657
2658 /*
2659 * compute the maximum size for icmp6 redirect header option.
2660 * XXX room for auth header?
2661 */
2662 len = maxlen - (p - (u_char *)ip6);
2663 len &= ~7;
2664
2665 /* This is just for simplicity. */
2666 if (m0->m_pkthdr.len != m0->m_len) {
2667 if (m0->m_next) {
2668 m_freem(m0->m_next);
2669 m0->m_next = NULL;
2670 }
2671 m0->m_pkthdr.len = m0->m_len;
2672 }
2673
2674 /*
2675 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2676 * about padding/truncate rule for the original IP packet.
2677 * From the discussion on IPv6imp in Feb 1999,
2678 * the consensus was:
2679 * - "attach as much as possible" is the goal
2680 * - pad if not aligned (original size can be guessed by
2681 * original ip6 header)
2682 * Following code adds the padding if it is simple enough,
2683 * and truncates if not.
2684 */
2685 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2686 panic("assumption failed in %s:%d", __FILE__,
2687 __LINE__);
2688
2689 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2690 /* not enough room, truncate */
2691 m0->m_pkthdr.len = m0->m_len = len -
2692 sizeof(*nd_opt_rh);
2693 } else {
2694 /* enough room, pad or truncate */
2695 size_t extra;
2696
2697 extra = m0->m_pkthdr.len % 8;
2698 if (extra) {
2699 /* pad if easy enough, truncate if not */
2700 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2701 /* pad */
2702 m0->m_len += (8 - extra);
2703 m0->m_pkthdr.len += (8 - extra);
2704 } else {
2705 /* truncate */
2706 m0->m_pkthdr.len -= extra;
2707 m0->m_len -= extra;
2708 }
2709 }
2710 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2711 m0->m_pkthdr.len = m0->m_len = len -
2712 sizeof(*nd_opt_rh);
2713 }
2714
2715 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2716 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2717 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2718 nd_opt_rh->nd_opt_rh_len = len >> 3;
2719 p += sizeof(*nd_opt_rh);
2720 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2721
2722 /* connect m0 to m */
2723 m_tag_delete_chain(m0, NULL);
2724 m0->m_flags &= ~M_PKTHDR;
2725 m->m_next = m0;
2726 m->m_pkthdr.len = m->m_len + m0->m_len;
2727 m0 = NULL;
2728 }
2729noredhdropt:;
2730 if (m0) {
2731 m_freem(m0);
2732 m0 = NULL;
2733 }
2734
2735 /* XXX: clear embedded link IDs in the inner header */
2736 in6_clearscope(&sip6->ip6_src);
2737 in6_clearscope(&sip6->ip6_dst);
2738 in6_clearscope(&nd_rd->nd_rd_target);
2739 in6_clearscope(&nd_rd->nd_rd_dst);
2740
2741 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2742
2743 nd_rd->nd_rd_cksum = 0;
2744 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2745 sizeof(*ip6), ntohs(ip6->ip6_plen));
2746
2747 /* send the packet to outside... */
2748 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2749 if (outif) {
2750 icmp6_ifstat_inc(outif, ifs6_out_msg);
2751 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2752 }
2753 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2754
2755 return;
2756
2757fail:
2758 if (m)
2759 m_freem(m);
2760 if (m0)
2761 m_freem(m0);
2762}
2763
2764/*
2765 * ICMPv6 socket option processing.
2766 */
2767int
2768icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2769{
2770 int error = 0;
2771 int optlen;
2772 struct inpcb *inp = sotoinpcb(so);
2773 int level, op, optname;
2774
2775 if (sopt) {
2776 level = sopt->sopt_level;
2777 op = sopt->sopt_dir;
2778 optname = sopt->sopt_name;
2779 optlen = sopt->sopt_valsize;
2780 } else
2781 level = op = optname = optlen = 0;
2782
2783 if (level != IPPROTO_ICMPV6) {
2784 return EINVAL;
2785 }
2786
2787 switch (op) {
2788 case PRCO_SETOPT:
2789 switch (optname) {
2790 case ICMP6_FILTER:
2791 {
2792 struct icmp6_filter ic6f;
2793
2794 if (optlen != sizeof(ic6f)) {
2795 error = EMSGSIZE;
2796 break;
2797 }
2798 error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2799 if (error == 0) {
2800 INP_WLOCK(inp);
2801 *inp->in6p_icmp6filt = ic6f;
2802 INP_WUNLOCK(inp);
2803 }
2804 break;
2805 }
2806
2807 default:
2808 error = ENOPROTOOPT;
2809 break;
2810 }
2811 break;
2812
2813 case PRCO_GETOPT:
2814 switch (optname) {
2815 case ICMP6_FILTER:
2816 {
2817 struct icmp6_filter ic6f;
2818
2819 INP_RLOCK(inp);
2820 ic6f = *inp->in6p_icmp6filt;
2821 INP_RUNLOCK(inp);
2822 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2823 break;
2824 }
2825
2826 default:
2827 error = ENOPROTOOPT;
2828 break;
2829 }
2830 break;
2831 }
2832
2833 return (error);
2834}
2835
2836/*
2837 * Perform rate limit check.
2838 * Returns 0 if it is okay to send the icmp6 packet.
2839 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2840 * limitation.
2841 *
2842 * XXX per-destination/type check necessary?
2843 *
2844 * dst - not used at this moment
2845 * type - not used at this moment
2846 * code - not used at this moment
2847 */
2848static int
2849icmp6_ratelimit(const struct in6_addr *dst, const int type,
2850 const int code)
2851{
2852 int ret;
2853
2854 ret = 0; /* okay to send */
2855
2856 /* PPS limit */
2857 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2858 V_icmp6errppslim)) {
2859 /* The packet is subject to rate limit */
2860 ret++;
2861 }
2862
2863 return ret;
2864}
| 146/*
147 * Kernel module interface for updating icmp6stat. The argument is an index
148 * into icmp6stat treated as an array of u_quad_t. While this encodes the
149 * general layout of icmp6stat into the caller, it doesn't encode its
150 * location, so that future changes to add, for example, per-CPU stats
151 * support won't cause binary compatibility problems for kernel modules.
152 */
153void
154kmod_icmp6stat_inc(int statnum)
155{
156
157 (*((u_quad_t *)&V_icmp6stat + statnum))++;
158}
159
160static void
161icmp6_errcount(struct icmp6errstat *stat, int type, int code)
162{
163 switch (type) {
164 case ICMP6_DST_UNREACH:
165 switch (code) {
166 case ICMP6_DST_UNREACH_NOROUTE:
167 stat->icp6errs_dst_unreach_noroute++;
168 return;
169 case ICMP6_DST_UNREACH_ADMIN:
170 stat->icp6errs_dst_unreach_admin++;
171 return;
172 case ICMP6_DST_UNREACH_BEYONDSCOPE:
173 stat->icp6errs_dst_unreach_beyondscope++;
174 return;
175 case ICMP6_DST_UNREACH_ADDR:
176 stat->icp6errs_dst_unreach_addr++;
177 return;
178 case ICMP6_DST_UNREACH_NOPORT:
179 stat->icp6errs_dst_unreach_noport++;
180 return;
181 }
182 break;
183 case ICMP6_PACKET_TOO_BIG:
184 stat->icp6errs_packet_too_big++;
185 return;
186 case ICMP6_TIME_EXCEEDED:
187 switch (code) {
188 case ICMP6_TIME_EXCEED_TRANSIT:
189 stat->icp6errs_time_exceed_transit++;
190 return;
191 case ICMP6_TIME_EXCEED_REASSEMBLY:
192 stat->icp6errs_time_exceed_reassembly++;
193 return;
194 }
195 break;
196 case ICMP6_PARAM_PROB:
197 switch (code) {
198 case ICMP6_PARAMPROB_HEADER:
199 stat->icp6errs_paramprob_header++;
200 return;
201 case ICMP6_PARAMPROB_NEXTHEADER:
202 stat->icp6errs_paramprob_nextheader++;
203 return;
204 case ICMP6_PARAMPROB_OPTION:
205 stat->icp6errs_paramprob_option++;
206 return;
207 }
208 break;
209 case ND_REDIRECT:
210 stat->icp6errs_redirect++;
211 return;
212 }
213 stat->icp6errs_unknown++;
214}
215
216/*
217 * A wrapper function for icmp6_error() necessary when the erroneous packet
218 * may not contain enough scope zone information.
219 */
220void
221icmp6_error2(struct mbuf *m, int type, int code, int param,
222 struct ifnet *ifp)
223{
224 struct ip6_hdr *ip6;
225
226 if (ifp == NULL)
227 return;
228
229#ifndef PULLDOWN_TEST
230 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
231#else
232 if (m->m_len < sizeof(struct ip6_hdr)) {
233 m = m_pullup(m, sizeof(struct ip6_hdr));
234 if (m == NULL)
235 return;
236 }
237#endif
238
239 ip6 = mtod(m, struct ip6_hdr *);
240
241 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
242 return;
243 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
244 return;
245
246 icmp6_error(m, type, code, param);
247}
248
249/*
250 * Generate an error packet of type error in response to bad IP6 packet.
251 */
252void
253icmp6_error(struct mbuf *m, int type, int code, int param)
254{
255 struct ip6_hdr *oip6, *nip6;
256 struct icmp6_hdr *icmp6;
257 u_int preplen;
258 int off;
259 int nxt;
260
261 ICMP6STAT_INC(icp6s_error);
262
263 /* count per-type-code statistics */
264 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code);
265
266#ifdef M_DECRYPTED /*not openbsd*/
267 if (m->m_flags & M_DECRYPTED) {
268 ICMP6STAT_INC(icp6s_canterror);
269 goto freeit;
270 }
271#endif
272
273#ifndef PULLDOWN_TEST
274 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
275#else
276 if (m->m_len < sizeof(struct ip6_hdr)) {
277 m = m_pullup(m, sizeof(struct ip6_hdr));
278 if (m == NULL)
279 return;
280 }
281#endif
282 oip6 = mtod(m, struct ip6_hdr *);
283
284 /*
285 * If the destination address of the erroneous packet is a multicast
286 * address, or the packet was sent using link-layer multicast,
287 * we should basically suppress sending an error (RFC 2463, Section
288 * 2.4).
289 * We have two exceptions (the item e.2 in that section):
290 * - the Packet Too Big message can be sent for path MTU discovery.
291 * - the Parameter Problem Message that can be allowed an icmp6 error
292 * in the option type field. This check has been done in
293 * ip6_unknown_opt(), so we can just check the type and code.
294 */
295 if ((m->m_flags & (M_BCAST|M_MCAST) ||
296 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
297 (type != ICMP6_PACKET_TOO_BIG &&
298 (type != ICMP6_PARAM_PROB ||
299 code != ICMP6_PARAMPROB_OPTION)))
300 goto freeit;
301
302 /*
303 * RFC 2463, 2.4 (e.5): source address check.
304 * XXX: the case of anycast source?
305 */
306 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
307 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
308 goto freeit;
309
310 /*
311 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
312 * don't do it.
313 */
314 nxt = -1;
315 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
316 if (off >= 0 && nxt == IPPROTO_ICMPV6) {
317 struct icmp6_hdr *icp;
318
319#ifndef PULLDOWN_TEST
320 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
321 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
322#else
323 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
324 sizeof(*icp));
325 if (icp == NULL) {
326 ICMP6STAT_INC(icp6s_tooshort);
327 return;
328 }
329#endif
330 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
331 icp->icmp6_type == ND_REDIRECT) {
332 /*
333 * ICMPv6 error
334 * Special case: for redirect (which is
335 * informational) we must not send icmp6 error.
336 */
337 ICMP6STAT_INC(icp6s_canterror);
338 goto freeit;
339 } else {
340 /* ICMPv6 informational - send the error */
341 }
342 } else {
343 /* non-ICMPv6 - send the error */
344 }
345
346 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
347
348 /* Finally, do rate limitation check. */
349 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
350 ICMP6STAT_INC(icp6s_toofreq);
351 goto freeit;
352 }
353
354 /*
355 * OK, ICMP6 can be generated.
356 */
357
358 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
359 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
360
361 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
362 M_PREPEND(m, preplen, M_DONTWAIT);
363 if (m && m->m_len < preplen)
364 m = m_pullup(m, preplen);
365 if (m == NULL) {
366 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
367 return;
368 }
369
370 nip6 = mtod(m, struct ip6_hdr *);
371 nip6->ip6_src = oip6->ip6_src;
372 nip6->ip6_dst = oip6->ip6_dst;
373
374 in6_clearscope(&oip6->ip6_src);
375 in6_clearscope(&oip6->ip6_dst);
376
377 icmp6 = (struct icmp6_hdr *)(nip6 + 1);
378 icmp6->icmp6_type = type;
379 icmp6->icmp6_code = code;
380 icmp6->icmp6_pptr = htonl((u_int32_t)param);
381
382 /*
383 * icmp6_reflect() is designed to be in the input path.
384 * icmp6_error() can be called from both input and output path,
385 * and if we are in output path rcvif could contain bogus value.
386 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
387 * information in ip header (nip6).
388 */
389 m->m_pkthdr.rcvif = NULL;
390
391 ICMP6STAT_INC(icp6s_outhist[type]);
392 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
393
394 return;
395
396 freeit:
397 /*
398 * If we can't tell whether or not we can generate ICMP6, free it.
399 */
400 m_freem(m);
401}
402
403/*
404 * Process a received ICMP6 message.
405 */
406int
407icmp6_input(struct mbuf **mp, int *offp, int proto)
408{
409 struct mbuf *m = *mp, *n;
410 struct ifnet *ifp;
411 struct ip6_hdr *ip6, *nip6;
412 struct icmp6_hdr *icmp6, *nicmp6;
413 int off = *offp;
414 int icmp6len = m->m_pkthdr.len - *offp;
415 int code, sum, noff;
416 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
417
418 ifp = m->m_pkthdr.rcvif;
419
420#ifndef PULLDOWN_TEST
421 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
422 /* m might change if M_LOOP. So, call mtod after this */
423#endif
424
425 /*
426 * Locate icmp6 structure in mbuf, and check
427 * that not corrupted and of at least minimum length
428 */
429
430 ip6 = mtod(m, struct ip6_hdr *);
431 if (icmp6len < sizeof(struct icmp6_hdr)) {
432 ICMP6STAT_INC(icp6s_tooshort);
433 goto freeit;
434 }
435
436 /*
437 * Check multicast group membership.
438 * Note: SSM filters are not applied for ICMPv6 traffic.
439 */
440 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
441 struct in6_multi *inm;
442
443 inm = in6m_lookup(ifp, &ip6->ip6_dst);
444 if (inm == NULL) {
445 IP6STAT_INC(ip6s_notmember);
446 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
447 goto freeit;
448 }
449 }
450
451 /*
452 * calculate the checksum
453 */
454#ifndef PULLDOWN_TEST
455 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
456#else
457 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
458 if (icmp6 == NULL) {
459 ICMP6STAT_INC(icp6s_tooshort);
460 return IPPROTO_DONE;
461 }
462#endif
463 code = icmp6->icmp6_code;
464
465 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
466 nd6log((LOG_ERR,
467 "ICMP6 checksum error(%d|%x) %s\n",
468 icmp6->icmp6_type, sum,
469 ip6_sprintf(ip6bufs, &ip6->ip6_src)));
470 ICMP6STAT_INC(icp6s_checksum);
471 goto freeit;
472 }
473
474 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
475 /*
476 * Deliver very specific ICMP6 type only.
477 * This is important to deliver TOOBIG. Otherwise PMTUD
478 * will not work.
479 */
480 switch (icmp6->icmp6_type) {
481 case ICMP6_DST_UNREACH:
482 case ICMP6_PACKET_TOO_BIG:
483 case ICMP6_TIME_EXCEEDED:
484 break;
485 default:
486 goto freeit;
487 }
488 }
489
490 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
491 icmp6_ifstat_inc(ifp, ifs6_in_msg);
492 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
493 icmp6_ifstat_inc(ifp, ifs6_in_error);
494
495 switch (icmp6->icmp6_type) {
496 case ICMP6_DST_UNREACH:
497 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
498 switch (code) {
499 case ICMP6_DST_UNREACH_NOROUTE:
500 code = PRC_UNREACH_NET;
501 break;
502 case ICMP6_DST_UNREACH_ADMIN:
503 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
504 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
505 break;
506 case ICMP6_DST_UNREACH_ADDR:
507 code = PRC_HOSTDEAD;
508 break;
509 case ICMP6_DST_UNREACH_BEYONDSCOPE:
510 /* I mean "source address was incorrect." */
511 code = PRC_PARAMPROB;
512 break;
513 case ICMP6_DST_UNREACH_NOPORT:
514 code = PRC_UNREACH_PORT;
515 break;
516 default:
517 goto badcode;
518 }
519 goto deliver;
520 break;
521
522 case ICMP6_PACKET_TOO_BIG:
523 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
524
525 /* validation is made in icmp6_mtudisc_update */
526
527 code = PRC_MSGSIZE;
528
529 /*
530 * Updating the path MTU will be done after examining
531 * intermediate extension headers.
532 */
533 goto deliver;
534 break;
535
536 case ICMP6_TIME_EXCEEDED:
537 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
538 switch (code) {
539 case ICMP6_TIME_EXCEED_TRANSIT:
540 code = PRC_TIMXCEED_INTRANS;
541 break;
542 case ICMP6_TIME_EXCEED_REASSEMBLY:
543 code = PRC_TIMXCEED_REASS;
544 break;
545 default:
546 goto badcode;
547 }
548 goto deliver;
549 break;
550
551 case ICMP6_PARAM_PROB:
552 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
553 switch (code) {
554 case ICMP6_PARAMPROB_NEXTHEADER:
555 code = PRC_UNREACH_PROTOCOL;
556 break;
557 case ICMP6_PARAMPROB_HEADER:
558 case ICMP6_PARAMPROB_OPTION:
559 code = PRC_PARAMPROB;
560 break;
561 default:
562 goto badcode;
563 }
564 goto deliver;
565 break;
566
567 case ICMP6_ECHO_REQUEST:
568 icmp6_ifstat_inc(ifp, ifs6_in_echo);
569 if (code != 0)
570 goto badcode;
571 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
572 /* Give up remote */
573 break;
574 }
575 if ((n->m_flags & M_EXT) != 0
576 || n->m_len < off + sizeof(struct icmp6_hdr)) {
577 struct mbuf *n0 = n;
578 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
579 int n0len;
580
581 MGETHDR(n, M_DONTWAIT, n0->m_type);
582 n0len = n0->m_pkthdr.len; /* save for use below */
583 if (n)
584 M_MOVE_PKTHDR(n, n0);
585 if (n && maxlen >= MHLEN) {
586 MCLGET(n, M_DONTWAIT);
587 if ((n->m_flags & M_EXT) == 0) {
588 m_free(n);
589 n = NULL;
590 }
591 }
592 if (n == NULL) {
593 /* Give up remote */
594 m_freem(n0);
595 break;
596 }
597 /*
598 * Copy IPv6 and ICMPv6 only.
599 */
600 nip6 = mtod(n, struct ip6_hdr *);
601 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
602 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
603 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
604 noff = sizeof(struct ip6_hdr);
605 /* new mbuf contains only ipv6+icmpv6 headers */
606 n->m_len = noff + sizeof(struct icmp6_hdr);
607 /*
608 * Adjust mbuf. ip6_plen will be adjusted in
609 * ip6_output().
610 */
611 m_adj(n0, off + sizeof(struct icmp6_hdr));
612 /* recalculate complete packet size */
613 n->m_pkthdr.len = n0len + (noff - off);
614 n->m_next = n0;
615 } else {
616 nip6 = mtod(n, struct ip6_hdr *);
617 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
618 sizeof(*nicmp6));
619 noff = off;
620 }
621 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
622 nicmp6->icmp6_code = 0;
623 if (n) {
624 ICMP6STAT_INC(icp6s_reflect);
625 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
626 icmp6_reflect(n, noff);
627 }
628 break;
629
630 case ICMP6_ECHO_REPLY:
631 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
632 if (code != 0)
633 goto badcode;
634 break;
635
636 case MLD_LISTENER_QUERY:
637 case MLD_LISTENER_REPORT:
638 case MLD_LISTENER_DONE:
639 case MLDV2_LISTENER_REPORT:
640 /*
641 * Drop MLD traffic which is not link-local, has a hop limit
642 * of greater than 1 hop, or which does not have the
643 * IPv6 HBH Router Alert option.
644 * As IPv6 HBH options are stripped in ip6_input() we must
645 * check an mbuf header flag.
646 * XXX Should we also sanity check that these messages
647 * were directed to a link-local multicast prefix?
648 */
649 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
650 goto freeit;
651 if (mld_input(m, off, icmp6len) != 0)
652 return (IPPROTO_DONE);
653 /* m stays. */
654 break;
655
656 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
657 {
658 enum { WRU, FQDN } mode;
659
660 if (!V_icmp6_nodeinfo)
661 break;
662
663 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
664 mode = WRU;
665 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
666 mode = FQDN;
667 else
668 goto badlen;
669
670 if (mode == FQDN) {
671#ifndef PULLDOWN_TEST
672 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
673 IPPROTO_DONE);
674#endif
675 n = m_copy(m, 0, M_COPYALL);
676 if (n)
677 n = ni6_input(n, off);
678 /* XXX meaningless if n == NULL */
679 noff = sizeof(struct ip6_hdr);
680 } else {
681 struct prison *pr;
682 u_char *p;
683 int maxlen, maxhlen, hlen;
684
685 /*
686 * XXX: this combination of flags is pointless,
687 * but should we keep this for compatibility?
688 */
689 if ((V_icmp6_nodeinfo & 5) != 5)
690 break;
691
692 if (code != 0)
693 goto badcode;
694 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
695 if (maxlen >= MCLBYTES) {
696 /* Give up remote */
697 break;
698 }
699 MGETHDR(n, M_DONTWAIT, m->m_type);
700 if (n && maxlen > MHLEN) {
701 MCLGET(n, M_DONTWAIT);
702 if ((n->m_flags & M_EXT) == 0) {
703 m_free(n);
704 n = NULL;
705 }
706 }
707 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
708 /*
709 * Previous code did a blind M_COPY_PKTHDR
710 * and said "just for rcvif". If true, then
711 * we could tolerate the dup failing (due to
712 * the deep copy of the tag chain). For now
713 * be conservative and just fail.
714 */
715 m_free(n);
716 n = NULL;
717 }
718 if (n == NULL) {
719 /* Give up remote */
720 break;
721 }
722 n->m_pkthdr.rcvif = NULL;
723 n->m_len = 0;
724 maxhlen = M_TRAILINGSPACE(n) - maxlen;
725 pr = curthread->td_ucred->cr_prison;
726 mtx_lock(&pr->pr_mtx);
727 hlen = strlen(pr->pr_hostname);
728 if (maxhlen > hlen)
729 maxhlen = hlen;
730 /*
731 * Copy IPv6 and ICMPv6 only.
732 */
733 nip6 = mtod(n, struct ip6_hdr *);
734 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
735 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
736 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
737 p = (u_char *)(nicmp6 + 1);
738 bzero(p, 4);
739 /* meaningless TTL */
740 bcopy(pr->pr_hostname, p + 4, maxhlen);
741 mtx_unlock(&pr->pr_mtx);
742 noff = sizeof(struct ip6_hdr);
743 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
744 sizeof(struct icmp6_hdr) + 4 + maxhlen;
745 nicmp6->icmp6_type = ICMP6_WRUREPLY;
746 nicmp6->icmp6_code = 0;
747 }
748 if (n) {
749 ICMP6STAT_INC(icp6s_reflect);
750 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
751 icmp6_reflect(n, noff);
752 }
753 break;
754 }
755
756 case ICMP6_WRUREPLY:
757 if (code != 0)
758 goto badcode;
759 break;
760
761 case ND_ROUTER_SOLICIT:
762 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
763 if (code != 0)
764 goto badcode;
765 if (icmp6len < sizeof(struct nd_router_solicit))
766 goto badlen;
767 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
768 /* give up local */
769 nd6_rs_input(m, off, icmp6len);
770 m = NULL;
771 goto freeit;
772 }
773 nd6_rs_input(n, off, icmp6len);
774 /* m stays. */
775 break;
776
777 case ND_ROUTER_ADVERT:
778 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
779 if (code != 0)
780 goto badcode;
781 if (icmp6len < sizeof(struct nd_router_advert))
782 goto badlen;
783 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
784 /* give up local */
785 nd6_ra_input(m, off, icmp6len);
786 m = NULL;
787 goto freeit;
788 }
789 nd6_ra_input(n, off, icmp6len);
790 /* m stays. */
791 break;
792
793 case ND_NEIGHBOR_SOLICIT:
794 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
795 if (code != 0)
796 goto badcode;
797 if (icmp6len < sizeof(struct nd_neighbor_solicit))
798 goto badlen;
799 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
800 /* give up local */
801 nd6_ns_input(m, off, icmp6len);
802 m = NULL;
803 goto freeit;
804 }
805 nd6_ns_input(n, off, icmp6len);
806 /* m stays. */
807 break;
808
809 case ND_NEIGHBOR_ADVERT:
810 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
811 if (code != 0)
812 goto badcode;
813 if (icmp6len < sizeof(struct nd_neighbor_advert))
814 goto badlen;
815 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
816 /* give up local */
817 nd6_na_input(m, off, icmp6len);
818 m = NULL;
819 goto freeit;
820 }
821 nd6_na_input(n, off, icmp6len);
822 /* m stays. */
823 break;
824
825 case ND_REDIRECT:
826 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
827 if (code != 0)
828 goto badcode;
829 if (icmp6len < sizeof(struct nd_redirect))
830 goto badlen;
831 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
832 /* give up local */
833 icmp6_redirect_input(m, off);
834 m = NULL;
835 goto freeit;
836 }
837 icmp6_redirect_input(n, off);
838 /* m stays. */
839 break;
840
841 case ICMP6_ROUTER_RENUMBERING:
842 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
843 code != ICMP6_ROUTER_RENUMBERING_RESULT)
844 goto badcode;
845 if (icmp6len < sizeof(struct icmp6_router_renum))
846 goto badlen;
847 break;
848
849 default:
850 nd6log((LOG_DEBUG,
851 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
852 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
853 ip6_sprintf(ip6bufd, &ip6->ip6_dst),
854 ifp ? ifp->if_index : 0));
855 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
856 /* ICMPv6 error: MUST deliver it by spec... */
857 code = PRC_NCMDS;
858 /* deliver */
859 } else {
860 /* ICMPv6 informational: MUST not deliver */
861 break;
862 }
863 deliver:
864 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
865 /* In this case, m should've been freed. */
866 return (IPPROTO_DONE);
867 }
868 break;
869
870 badcode:
871 ICMP6STAT_INC(icp6s_badcode);
872 break;
873
874 badlen:
875 ICMP6STAT_INC(icp6s_badlen);
876 break;
877 }
878
879 /* deliver the packet to appropriate sockets */
880 icmp6_rip6_input(&m, *offp);
881
882 return IPPROTO_DONE;
883
884 freeit:
885 m_freem(m);
886 return IPPROTO_DONE;
887}
888
889static int
890icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
891{
892 struct mbuf *m = *mp;
893 struct icmp6_hdr *icmp6;
894 struct ip6_hdr *eip6;
895 u_int32_t notifymtu;
896 struct sockaddr_in6 icmp6src, icmp6dst;
897
898 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
899 ICMP6STAT_INC(icp6s_tooshort);
900 goto freeit;
901 }
902#ifndef PULLDOWN_TEST
903 IP6_EXTHDR_CHECK(m, off,
904 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
905 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
906#else
907 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
908 sizeof(*icmp6) + sizeof(struct ip6_hdr));
909 if (icmp6 == NULL) {
910 ICMP6STAT_INC(icp6s_tooshort);
911 return (-1);
912 }
913#endif
914 eip6 = (struct ip6_hdr *)(icmp6 + 1);
915
916 /* Detect the upper level protocol */
917 {
918 void (*ctlfunc)(int, struct sockaddr *, void *);
919 u_int8_t nxt = eip6->ip6_nxt;
920 int eoff = off + sizeof(struct icmp6_hdr) +
921 sizeof(struct ip6_hdr);
922 struct ip6ctlparam ip6cp;
923 struct in6_addr *finaldst = NULL;
924 int icmp6type = icmp6->icmp6_type;
925 struct ip6_frag *fh;
926 struct ip6_rthdr *rth;
927 struct ip6_rthdr0 *rth0;
928 int rthlen;
929
930 while (1) { /* XXX: should avoid infinite loop explicitly? */
931 struct ip6_ext *eh;
932
933 switch (nxt) {
934 case IPPROTO_HOPOPTS:
935 case IPPROTO_DSTOPTS:
936 case IPPROTO_AH:
937#ifndef PULLDOWN_TEST
938 IP6_EXTHDR_CHECK(m, 0,
939 eoff + sizeof(struct ip6_ext), -1);
940 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
941#else
942 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
943 eoff, sizeof(*eh));
944 if (eh == NULL) {
945 ICMP6STAT_INC(icp6s_tooshort);
946 return (-1);
947 }
948#endif
949
950 if (nxt == IPPROTO_AH)
951 eoff += (eh->ip6e_len + 2) << 2;
952 else
953 eoff += (eh->ip6e_len + 1) << 3;
954 nxt = eh->ip6e_nxt;
955 break;
956 case IPPROTO_ROUTING:
957 /*
958 * When the erroneous packet contains a
959 * routing header, we should examine the
960 * header to determine the final destination.
961 * Otherwise, we can't properly update
962 * information that depends on the final
963 * destination (e.g. path MTU).
964 */
965#ifndef PULLDOWN_TEST
966 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
967 rth = (struct ip6_rthdr *)
968 (mtod(m, caddr_t) + eoff);
969#else
970 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
971 eoff, sizeof(*rth));
972 if (rth == NULL) {
973 ICMP6STAT_INC(icp6s_tooshort);
974 return (-1);
975 }
976#endif
977 rthlen = (rth->ip6r_len + 1) << 3;
978 /*
979 * XXX: currently there is no
980 * officially defined type other
981 * than type-0.
982 * Note that if the segment left field
983 * is 0, all intermediate hops must
984 * have been passed.
985 */
986 if (rth->ip6r_segleft &&
987 rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
988 int hops;
989
990#ifndef PULLDOWN_TEST
991 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
992 rth0 = (struct ip6_rthdr0 *)
993 (mtod(m, caddr_t) + eoff);
994#else
995 IP6_EXTHDR_GET(rth0,
996 struct ip6_rthdr0 *, m,
997 eoff, rthlen);
998 if (rth0 == NULL) {
999 ICMP6STAT_INC(icp6s_tooshort);
1000 return (-1);
1001 }
1002#endif
1003 /* just ignore a bogus header */
1004 if ((rth0->ip6r0_len % 2) == 0 &&
1005 (hops = rth0->ip6r0_len/2))
1006 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1007 }
1008 eoff += rthlen;
1009 nxt = rth->ip6r_nxt;
1010 break;
1011 case IPPROTO_FRAGMENT:
1012#ifndef PULLDOWN_TEST
1013 IP6_EXTHDR_CHECK(m, 0, eoff +
1014 sizeof(struct ip6_frag), -1);
1015 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1016 eoff);
1017#else
1018 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1019 eoff, sizeof(*fh));
1020 if (fh == NULL) {
1021 ICMP6STAT_INC(icp6s_tooshort);
1022 return (-1);
1023 }
1024#endif
1025 /*
1026 * Data after a fragment header is meaningless
1027 * unless it is the first fragment, but
1028 * we'll go to the notify label for path MTU
1029 * discovery.
1030 */
1031 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1032 goto notify;
1033
1034 eoff += sizeof(struct ip6_frag);
1035 nxt = fh->ip6f_nxt;
1036 break;
1037 default:
1038 /*
1039 * This case includes ESP and the No Next
1040 * Header. In such cases going to the notify
1041 * label does not have any meaning
1042 * (i.e. ctlfunc will be NULL), but we go
1043 * anyway since we might have to update
1044 * path MTU information.
1045 */
1046 goto notify;
1047 }
1048 }
1049 notify:
1050#ifndef PULLDOWN_TEST
1051 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1052#else
1053 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1054 sizeof(*icmp6) + sizeof(struct ip6_hdr));
1055 if (icmp6 == NULL) {
1056 ICMP6STAT_INC(icp6s_tooshort);
1057 return (-1);
1058 }
1059#endif
1060
1061 /*
1062 * retrieve parameters from the inner IPv6 header, and convert
1063 * them into sockaddr structures.
1064 * XXX: there is no guarantee that the source or destination
1065 * addresses of the inner packet are in the same scope as
1066 * the addresses of the icmp packet. But there is no other
1067 * way to determine the zone.
1068 */
1069 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1070
1071 bzero(&icmp6dst, sizeof(icmp6dst));
1072 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1073 icmp6dst.sin6_family = AF_INET6;
1074 if (finaldst == NULL)
1075 icmp6dst.sin6_addr = eip6->ip6_dst;
1076 else
1077 icmp6dst.sin6_addr = *finaldst;
1078 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1079 goto freeit;
1080 bzero(&icmp6src, sizeof(icmp6src));
1081 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1082 icmp6src.sin6_family = AF_INET6;
1083 icmp6src.sin6_addr = eip6->ip6_src;
1084 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1085 goto freeit;
1086 icmp6src.sin6_flowinfo =
1087 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1088
1089 if (finaldst == NULL)
1090 finaldst = &eip6->ip6_dst;
1091 ip6cp.ip6c_m = m;
1092 ip6cp.ip6c_icmp6 = icmp6;
1093 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1094 ip6cp.ip6c_off = eoff;
1095 ip6cp.ip6c_finaldst = finaldst;
1096 ip6cp.ip6c_src = &icmp6src;
1097 ip6cp.ip6c_nxt = nxt;
1098
1099 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1100 notifymtu = ntohl(icmp6->icmp6_mtu);
1101 ip6cp.ip6c_cmdarg = (void *)¬ifymtu;
1102 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
1103 }
1104
1105 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1106 (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1107 if (ctlfunc) {
1108 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1109 &ip6cp);
1110 }
1111 }
1112 *mp = m;
1113 return (0);
1114
1115 freeit:
1116 m_freem(m);
1117 return (-1);
1118}
1119
1120void
1121icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1122{
1123 struct in6_addr *dst = ip6cp->ip6c_finaldst;
1124 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1125 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1126 u_int mtu = ntohl(icmp6->icmp6_mtu);
1127 struct in_conninfo inc;
1128
1129#if 0
1130 /*
1131 * RFC2460 section 5, last paragraph.
1132 * even though minimum link MTU for IPv6 is IPV6_MMTU,
1133 * we may see ICMPv6 too big with mtu < IPV6_MMTU
1134 * due to packet translator in the middle.
1135 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1136 * special handling.
1137 */
1138 if (mtu < IPV6_MMTU)
1139 return;
1140#endif
1141
1142 /*
1143 * we reject ICMPv6 too big with abnormally small value.
1144 * XXX what is the good definition of "abnormally small"?
1145 */
1146 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1147 return;
1148
1149 if (!validated)
1150 return;
1151
1152 /*
1153 * In case the suggested mtu is less than IPV6_MMTU, we
1154 * only need to remember that it was for above mentioned
1155 * "alwaysfrag" case.
1156 * Try to be as close to the spec as possible.
1157 */
1158 if (mtu < IPV6_MMTU)
1159 mtu = IPV6_MMTU - 8;
1160
1161 bzero(&inc, sizeof(inc));
1162 inc.inc_flags |= INC_ISIPV6;
1163 inc.inc6_faddr = *dst;
1164 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1165 return;
1166
1167 if (mtu < tcp_maxmtu6(&inc, NULL)) {
1168 tcp_hc_updatemtu(&inc, mtu);
1169 ICMP6STAT_INC(icp6s_pmtuchg);
1170 }
1171}
1172
1173/*
1174 * Process a Node Information Query packet, based on
1175 * draft-ietf-ipngwg-icmp-name-lookups-07.
1176 *
1177 * Spec incompatibilities:
1178 * - IPv6 Subject address handling
1179 * - IPv4 Subject address handling support missing
1180 * - Proxy reply (answer even if it's not for me)
1181 * - joins NI group address at in6_ifattach() time only, does not cope
1182 * with hostname changes by sethostname(3)
1183 */
1184static struct mbuf *
1185ni6_input(struct mbuf *m, int off)
1186{
1187 struct icmp6_nodeinfo *ni6, *nni6;
1188 struct mbuf *n = NULL;
1189 struct prison *pr;
1190 u_int16_t qtype;
1191 int subjlen;
1192 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1193 struct ni_reply_fqdn *fqdn;
1194 int addrs; /* for NI_QTYPE_NODEADDR */
1195 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1196 struct in6_addr in6_subj; /* subject address */
1197 struct ip6_hdr *ip6;
1198 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
1199 char *subj = NULL;
1200 struct in6_ifaddr *ia6 = NULL;
1201
1202 ip6 = mtod(m, struct ip6_hdr *);
1203#ifndef PULLDOWN_TEST
1204 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1205#else
1206 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1207 if (ni6 == NULL) {
1208 /* m is already reclaimed */
1209 return (NULL);
1210 }
1211#endif
1212
1213 /*
1214 * Validate IPv6 source address.
1215 * The default configuration MUST be to refuse answering queries from
1216 * global-scope addresses according to RFC4602.
1217 * Notes:
1218 * - it's not very clear what "refuse" means; this implementation
1219 * simply drops it.
1220 * - it's not very easy to identify global-scope (unicast) addresses
1221 * since there are many prefixes for them. It should be safer
1222 * and in practice sufficient to check "all" but loopback and
1223 * link-local (note that site-local unicast was deprecated and
1224 * ULA is defined as global scope-wise)
1225 */
1226 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1227 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1228 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1229 goto bad;
1230
1231 /*
1232 * Validate IPv6 destination address.
1233 *
1234 * The Responder must discard the Query without further processing
1235 * unless it is one of the Responder's unicast or anycast addresses, or
1236 * a link-local scope multicast address which the Responder has joined.
1237 * [RFC4602, Section 5.]
1238 */
1239 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1240 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1241 goto bad;
1242 /* else it's a link-local multicast, fine */
1243 } else { /* unicast or anycast */
1244 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1245 goto bad; /* XXX impossible */
1246
1247 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1248 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1249 ifa_free(&ia6->ia_ifa);
1250 nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1251 "a temporary address in %s:%d",
1252 __FILE__, __LINE__));
1253 goto bad;
1254 }
1255 ifa_free(&ia6->ia_ifa);
1256 }
1257
1258 /* validate query Subject field. */
1259 qtype = ntohs(ni6->ni_qtype);
1260 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1261 switch (qtype) {
1262 case NI_QTYPE_NOOP:
1263 case NI_QTYPE_SUPTYPES:
1264 /* 07 draft */
1265 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1266 break;
1267 /* FALLTHROUGH */
1268 case NI_QTYPE_FQDN:
1269 case NI_QTYPE_NODEADDR:
1270 case NI_QTYPE_IPV4ADDR:
1271 switch (ni6->ni_code) {
1272 case ICMP6_NI_SUBJ_IPV6:
1273#if ICMP6_NI_SUBJ_IPV6 != 0
1274 case 0:
1275#endif
1276 /*
1277 * backward compatibility - try to accept 03 draft
1278 * format, where no Subject is present.
1279 */
1280 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1281 subjlen == 0) {
1282 oldfqdn++;
1283 break;
1284 }
1285#if ICMP6_NI_SUBJ_IPV6 != 0
1286 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1287 goto bad;
1288#endif
1289
1290 if (subjlen != sizeof(struct in6_addr))
1291 goto bad;
1292
1293 /*
1294 * Validate Subject address.
1295 *
1296 * Not sure what exactly "address belongs to the node"
1297 * means in the spec, is it just unicast, or what?
1298 *
1299 * At this moment we consider Subject address as
1300 * "belong to the node" if the Subject address equals
1301 * to the IPv6 destination address; validation for
1302 * IPv6 destination address should have done enough
1303 * check for us.
1304 *
1305 * We do not do proxy at this moment.
1306 */
1307 /* m_pulldown instead of copy? */
1308 m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1309 subjlen, (caddr_t)&in6_subj);
1310 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1311 goto bad;
1312
1313 subj = (char *)&in6_subj;
1314 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1315 break;
1316
1317 /*
1318 * XXX if we are to allow other cases, we should really
1319 * be careful about scope here.
1320 * basically, we should disallow queries toward IPv6
1321 * destination X with subject Y,
1322 * if scope(X) > scope(Y).
1323 * if we allow scope(X) > scope(Y), it will result in
1324 * information leakage across scope boundary.
1325 */
1326 goto bad;
1327
1328 case ICMP6_NI_SUBJ_FQDN:
1329 /*
1330 * Validate Subject name with gethostname(3).
1331 *
1332 * The behavior may need some debate, since:
1333 * - we are not sure if the node has FQDN as
1334 * hostname (returned by gethostname(3)).
1335 * - the code does wildcard match for truncated names.
1336 * however, we are not sure if we want to perform
1337 * wildcard match, if gethostname(3) side has
1338 * truncated hostname.
1339 */
1340 pr = curthread->td_ucred->cr_prison;
1341 mtx_lock(&pr->pr_mtx);
1342 n = ni6_nametodns(pr->pr_hostname,
1343 strlen(pr->pr_hostname), 0);
1344 mtx_unlock(&pr->pr_mtx);
1345 if (!n || n->m_next || n->m_len == 0)
1346 goto bad;
1347 IP6_EXTHDR_GET(subj, char *, m,
1348 off + sizeof(struct icmp6_nodeinfo), subjlen);
1349 if (subj == NULL)
1350 goto bad;
1351 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1352 n->m_len)) {
1353 goto bad;
1354 }
1355 m_freem(n);
1356 n = NULL;
1357 break;
1358
1359 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
1360 default:
1361 goto bad;
1362 }
1363 break;
1364 }
1365
1366 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
1367 switch (qtype) {
1368 case NI_QTYPE_FQDN:
1369 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1370 goto bad;
1371 break;
1372 case NI_QTYPE_NODEADDR:
1373 case NI_QTYPE_IPV4ADDR:
1374 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1375 goto bad;
1376 break;
1377 }
1378
1379 /* guess reply length */
1380 switch (qtype) {
1381 case NI_QTYPE_NOOP:
1382 break; /* no reply data */
1383 case NI_QTYPE_SUPTYPES:
1384 replylen += sizeof(u_int32_t);
1385 break;
1386 case NI_QTYPE_FQDN:
1387 /* XXX will append an mbuf */
1388 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1389 break;
1390 case NI_QTYPE_NODEADDR:
1391 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1392 if ((replylen += addrs * (sizeof(struct in6_addr) +
1393 sizeof(u_int32_t))) > MCLBYTES)
1394 replylen = MCLBYTES; /* XXX: will truncate pkt later */
1395 break;
1396 case NI_QTYPE_IPV4ADDR:
1397 /* unsupported - should respond with unknown Qtype? */
1398 break;
1399 default:
1400 /*
1401 * XXX: We must return a reply with the ICMP6 code
1402 * `unknown Qtype' in this case. However we regard the case
1403 * as an FQDN query for backward compatibility.
1404 * Older versions set a random value to this field,
1405 * so it rarely varies in the defined qtypes.
1406 * But the mechanism is not reliable...
1407 * maybe we should obsolete older versions.
1408 */
1409 qtype = NI_QTYPE_FQDN;
1410 /* XXX will append an mbuf */
1411 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1412 oldfqdn++;
1413 break;
1414 }
1415
1416 /* allocate an mbuf to reply. */
1417 MGETHDR(n, M_DONTWAIT, m->m_type);
1418 if (n == NULL) {
1419 m_freem(m);
1420 return (NULL);
1421 }
1422 M_MOVE_PKTHDR(n, m); /* just for recvif */
1423 if (replylen > MHLEN) {
1424 if (replylen > MCLBYTES) {
1425 /*
1426 * XXX: should we try to allocate more? But MCLBYTES
1427 * is probably much larger than IPV6_MMTU...
1428 */
1429 goto bad;
1430 }
1431 MCLGET(n, M_DONTWAIT);
1432 if ((n->m_flags & M_EXT) == 0) {
1433 goto bad;
1434 }
1435 }
1436 n->m_pkthdr.len = n->m_len = replylen;
1437
1438 /* copy mbuf header and IPv6 + Node Information base headers */
1439 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1440 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1441 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1442
1443 /* qtype dependent procedure */
1444 switch (qtype) {
1445 case NI_QTYPE_NOOP:
1446 nni6->ni_code = ICMP6_NI_SUCCESS;
1447 nni6->ni_flags = 0;
1448 break;
1449 case NI_QTYPE_SUPTYPES:
1450 {
1451 u_int32_t v;
1452 nni6->ni_code = ICMP6_NI_SUCCESS;
1453 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1454 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1455 v = (u_int32_t)htonl(0x0000000f);
1456 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1457 break;
1458 }
1459 case NI_QTYPE_FQDN:
1460 nni6->ni_code = ICMP6_NI_SUCCESS;
1461 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1462 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1463 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1464 fqdn->ni_fqdn_ttl = 0; /* ditto. */
1465 /*
1466 * XXX do we really have FQDN in hostname?
1467 */
1468 pr = curthread->td_ucred->cr_prison;
1469 mtx_lock(&pr->pr_mtx);
1470 n->m_next = ni6_nametodns(pr->pr_hostname,
1471 strlen(pr->pr_hostname), oldfqdn);
1472 mtx_unlock(&pr->pr_mtx);
1473 if (n->m_next == NULL)
1474 goto bad;
1475 /* XXX we assume that n->m_next is not a chain */
1476 if (n->m_next->m_next != NULL)
1477 goto bad;
1478 n->m_pkthdr.len += n->m_next->m_len;
1479 break;
1480 case NI_QTYPE_NODEADDR:
1481 {
1482 int lenlim, copied;
1483
1484 nni6->ni_code = ICMP6_NI_SUCCESS;
1485 n->m_pkthdr.len = n->m_len =
1486 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1487 lenlim = M_TRAILINGSPACE(n);
1488 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1489 /* XXX: reset mbuf length */
1490 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1491 sizeof(struct icmp6_nodeinfo) + copied;
1492 break;
1493 }
1494 default:
1495 break; /* XXX impossible! */
1496 }
1497
1498 nni6->ni_type = ICMP6_NI_REPLY;
1499 m_freem(m);
1500 return (n);
1501
1502 bad:
1503 m_freem(m);
1504 if (n)
1505 m_freem(n);
1506 return (NULL);
1507}
1508
1509/*
1510 * make a mbuf with DNS-encoded string. no compression support.
1511 *
1512 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1513 * treated as truncated name (two \0 at the end). this is a wild guess.
1514 *
1515 * old - return pascal string if non-zero
1516 */
1517static struct mbuf *
1518ni6_nametodns(const char *name, int namelen, int old)
1519{
1520 struct mbuf *m;
1521 char *cp, *ep;
1522 const char *p, *q;
1523 int i, len, nterm;
1524
1525 if (old)
1526 len = namelen + 1;
1527 else
1528 len = MCLBYTES;
1529
1530 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1531 MGET(m, M_DONTWAIT, MT_DATA);
1532 if (m && len > MLEN) {
1533 MCLGET(m, M_DONTWAIT);
1534 if ((m->m_flags & M_EXT) == 0)
1535 goto fail;
1536 }
1537 if (!m)
1538 goto fail;
1539 m->m_next = NULL;
1540
1541 if (old) {
1542 m->m_len = len;
1543 *mtod(m, char *) = namelen;
1544 bcopy(name, mtod(m, char *) + 1, namelen);
1545 return m;
1546 } else {
1547 m->m_len = 0;
1548 cp = mtod(m, char *);
1549 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1550
1551 /* if not certain about my name, return empty buffer */
1552 if (namelen == 0)
1553 return m;
1554
1555 /*
1556 * guess if it looks like shortened hostname, or FQDN.
1557 * shortened hostname needs two trailing "\0".
1558 */
1559 i = 0;
1560 for (p = name; p < name + namelen; p++) {
1561 if (*p && *p == '.')
1562 i++;
1563 }
1564 if (i < 2)
1565 nterm = 2;
1566 else
1567 nterm = 1;
1568
1569 p = name;
1570 while (cp < ep && p < name + namelen) {
1571 i = 0;
1572 for (q = p; q < name + namelen && *q && *q != '.'; q++)
1573 i++;
1574 /* result does not fit into mbuf */
1575 if (cp + i + 1 >= ep)
1576 goto fail;
1577 /*
1578 * DNS label length restriction, RFC1035 page 8.
1579 * "i == 0" case is included here to avoid returning
1580 * 0-length label on "foo..bar".
1581 */
1582 if (i <= 0 || i >= 64)
1583 goto fail;
1584 *cp++ = i;
1585 bcopy(p, cp, i);
1586 cp += i;
1587 p = q;
1588 if (p < name + namelen && *p == '.')
1589 p++;
1590 }
1591 /* termination */
1592 if (cp + nterm >= ep)
1593 goto fail;
1594 while (nterm-- > 0)
1595 *cp++ = '\0';
1596 m->m_len = cp - mtod(m, char *);
1597 return m;
1598 }
1599
1600 panic("should not reach here");
1601 /* NOTREACHED */
1602
1603 fail:
1604 if (m)
1605 m_freem(m);
1606 return NULL;
1607}
1608
1609/*
1610 * check if two DNS-encoded string matches. takes care of truncated
1611 * form (with \0\0 at the end). no compression support.
1612 * XXX upper/lowercase match (see RFC2065)
1613 */
1614static int
1615ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1616{
1617 const char *a0, *b0;
1618 int l;
1619
1620 /* simplest case - need validation? */
1621 if (alen == blen && bcmp(a, b, alen) == 0)
1622 return 1;
1623
1624 a0 = a;
1625 b0 = b;
1626
1627 /* termination is mandatory */
1628 if (alen < 2 || blen < 2)
1629 return 0;
1630 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1631 return 0;
1632 alen--;
1633 blen--;
1634
1635 while (a - a0 < alen && b - b0 < blen) {
1636 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1637 return 0;
1638
1639 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1640 return 0;
1641 /* we don't support compression yet */
1642 if (a[0] >= 64 || b[0] >= 64)
1643 return 0;
1644
1645 /* truncated case */
1646 if (a[0] == 0 && a - a0 == alen - 1)
1647 return 1;
1648 if (b[0] == 0 && b - b0 == blen - 1)
1649 return 1;
1650 if (a[0] == 0 || b[0] == 0)
1651 return 0;
1652
1653 if (a[0] != b[0])
1654 return 0;
1655 l = a[0];
1656 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1657 return 0;
1658 if (bcmp(a + 1, b + 1, l) != 0)
1659 return 0;
1660
1661 a += 1 + l;
1662 b += 1 + l;
1663 }
1664
1665 if (a - a0 == alen && b - b0 == blen)
1666 return 1;
1667 else
1668 return 0;
1669}
1670
1671/*
1672 * calculate the number of addresses to be returned in the node info reply.
1673 */
1674static int
1675ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1676 struct in6_addr *subj)
1677{
1678 struct ifnet *ifp;
1679 struct in6_ifaddr *ifa6;
1680 struct ifaddr *ifa;
1681 int addrs = 0, addrsofif, iffound = 0;
1682 int niflags = ni6->ni_flags;
1683
1684 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1685 switch (ni6->ni_code) {
1686 case ICMP6_NI_SUBJ_IPV6:
1687 if (subj == NULL) /* must be impossible... */
1688 return (0);
1689 break;
1690 default:
1691 /*
1692 * XXX: we only support IPv6 subject address for
1693 * this Qtype.
1694 */
1695 return (0);
1696 }
1697 }
1698
1699 IFNET_RLOCK_NOSLEEP();
1700 for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1701 addrsofif = 0;
1702 IF_ADDR_LOCK(ifp);
1703 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1704 if (ifa->ifa_addr->sa_family != AF_INET6)
1705 continue;
1706 ifa6 = (struct in6_ifaddr *)ifa;
1707
1708 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1709 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1710 iffound = 1;
1711
1712 /*
1713 * IPv4-mapped addresses can only be returned by a
1714 * Node Information proxy, since they represent
1715 * addresses of IPv4-only nodes, which perforce do
1716 * not implement this protocol.
1717 * [icmp-name-lookups-07, Section 5.4]
1718 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1719 * this function at this moment.
1720 */
1721
1722 /* What do we have to do about ::1? */
1723 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1724 case IPV6_ADDR_SCOPE_LINKLOCAL:
1725 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1726 continue;
1727 break;
1728 case IPV6_ADDR_SCOPE_SITELOCAL:
1729 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1730 continue;
1731 break;
1732 case IPV6_ADDR_SCOPE_GLOBAL:
1733 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1734 continue;
1735 break;
1736 default:
1737 continue;
1738 }
1739
1740 /*
1741 * check if anycast is okay.
1742 * XXX: just experimental. not in the spec.
1743 */
1744 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1745 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1746 continue; /* we need only unicast addresses */
1747 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1748 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1749 continue;
1750 }
1751 addrsofif++; /* count the address */
1752 }
1753 IF_ADDR_UNLOCK(ifp);
1754 if (iffound) {
1755 *ifpp = ifp;
1756 IFNET_RUNLOCK_NOSLEEP();
1757 return (addrsofif);
1758 }
1759
1760 addrs += addrsofif;
1761 }
1762 IFNET_RUNLOCK_NOSLEEP();
1763
1764 return (addrs);
1765}
1766
1767static int
1768ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1769 struct ifnet *ifp0, int resid)
1770{
1771 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1772 struct in6_ifaddr *ifa6;
1773 struct ifaddr *ifa;
1774 struct ifnet *ifp_dep = NULL;
1775 int copied = 0, allow_deprecated = 0;
1776 u_char *cp = (u_char *)(nni6 + 1);
1777 int niflags = ni6->ni_flags;
1778 u_int32_t ltime;
1779
1780 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1781 return (0); /* needless to copy */
1782
1783 IFNET_RLOCK_NOSLEEP();
1784 again:
1785
1786 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1787 IF_ADDR_LOCK(ifp);
1788 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1789 if (ifa->ifa_addr->sa_family != AF_INET6)
1790 continue;
1791 ifa6 = (struct in6_ifaddr *)ifa;
1792
1793 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1794 allow_deprecated == 0) {
1795 /*
1796 * prefererred address should be put before
1797 * deprecated addresses.
1798 */
1799
1800 /* record the interface for later search */
1801 if (ifp_dep == NULL)
1802 ifp_dep = ifp;
1803
1804 continue;
1805 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1806 allow_deprecated != 0)
1807 continue; /* we now collect deprecated addrs */
1808
1809 /* What do we have to do about ::1? */
1810 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1811 case IPV6_ADDR_SCOPE_LINKLOCAL:
1812 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1813 continue;
1814 break;
1815 case IPV6_ADDR_SCOPE_SITELOCAL:
1816 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1817 continue;
1818 break;
1819 case IPV6_ADDR_SCOPE_GLOBAL:
1820 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1821 continue;
1822 break;
1823 default:
1824 continue;
1825 }
1826
1827 /*
1828 * check if anycast is okay.
1829 * XXX: just experimental. not in the spec.
1830 */
1831 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1832 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1833 continue;
1834 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1835 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1836 continue;
1837 }
1838
1839 /* now we can copy the address */
1840 if (resid < sizeof(struct in6_addr) +
1841 sizeof(u_int32_t)) {
1842 IF_ADDR_UNLOCK(ifp);
1843 /*
1844 * We give up much more copy.
1845 * Set the truncate flag and return.
1846 */
1847 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1848 IFNET_RUNLOCK_NOSLEEP();
1849 return (copied);
1850 }
1851
1852 /*
1853 * Set the TTL of the address.
1854 * The TTL value should be one of the following
1855 * according to the specification:
1856 *
1857 * 1. The remaining lifetime of a DHCP lease on the
1858 * address, or
1859 * 2. The remaining Valid Lifetime of a prefix from
1860 * which the address was derived through Stateless
1861 * Autoconfiguration.
1862 *
1863 * Note that we currently do not support stateful
1864 * address configuration by DHCPv6, so the former
1865 * case can't happen.
1866 */
1867 if (ifa6->ia6_lifetime.ia6t_expire == 0)
1868 ltime = ND6_INFINITE_LIFETIME;
1869 else {
1870 if (ifa6->ia6_lifetime.ia6t_expire >
1871 time_second)
1872 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1873 else
1874 ltime = 0;
1875 }
1876
1877 bcopy(<ime, cp, sizeof(u_int32_t));
1878 cp += sizeof(u_int32_t);
1879
1880 /* copy the address itself */
1881 bcopy(&ifa6->ia_addr.sin6_addr, cp,
1882 sizeof(struct in6_addr));
1883 in6_clearscope((struct in6_addr *)cp); /* XXX */
1884 cp += sizeof(struct in6_addr);
1885
1886 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1887 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1888 }
1889 IF_ADDR_UNLOCK(ifp);
1890 if (ifp0) /* we need search only on the specified IF */
1891 break;
1892 }
1893
1894 if (allow_deprecated == 0 && ifp_dep != NULL) {
1895 ifp = ifp_dep;
1896 allow_deprecated = 1;
1897
1898 goto again;
1899 }
1900
1901 IFNET_RUNLOCK_NOSLEEP();
1902
1903 return (copied);
1904}
1905
1906/*
1907 * XXX almost dup'ed code with rip6_input.
1908 */
1909static int
1910icmp6_rip6_input(struct mbuf **mp, int off)
1911{
1912 struct mbuf *m = *mp;
1913 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1914 struct inpcb *in6p;
1915 struct inpcb *last = NULL;
1916 struct sockaddr_in6 fromsa;
1917 struct icmp6_hdr *icmp6;
1918 struct mbuf *opts = NULL;
1919
1920#ifndef PULLDOWN_TEST
1921 /* this is assumed to be safe. */
1922 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1923#else
1924 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1925 if (icmp6 == NULL) {
1926 /* m is already reclaimed */
1927 return (IPPROTO_DONE);
1928 }
1929#endif
1930
1931 /*
1932 * XXX: the address may have embedded scope zone ID, which should be
1933 * hidden from applications.
1934 */
1935 bzero(&fromsa, sizeof(fromsa));
1936 fromsa.sin6_family = AF_INET6;
1937 fromsa.sin6_len = sizeof(struct sockaddr_in6);
1938 fromsa.sin6_addr = ip6->ip6_src;
1939 if (sa6_recoverscope(&fromsa)) {
1940 m_freem(m);
1941 return (IPPROTO_DONE);
1942 }
1943
1944 INP_INFO_RLOCK(&V_ripcbinfo);
1945 LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1946 if ((in6p->inp_vflag & INP_IPV6) == 0)
1947 continue;
1948 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1949 continue;
1950 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1951 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1952 continue;
1953 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1954 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1955 continue;
1956 INP_RLOCK(in6p);
1957 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1958 in6p->in6p_icmp6filt)) {
1959 INP_RUNLOCK(in6p);
1960 continue;
1961 }
1962 if (last != NULL) {
1963 struct mbuf *n = NULL;
1964
1965 /*
1966 * Recent network drivers tend to allocate a single
1967 * mbuf cluster, rather than to make a couple of
1968 * mbufs without clusters. Also, since the IPv6 code
1969 * path tries to avoid m_pullup(), it is highly
1970 * probable that we still have an mbuf cluster here
1971 * even though the necessary length can be stored in an
1972 * mbuf's internal buffer.
1973 * Meanwhile, the default size of the receive socket
1974 * buffer for raw sockets is not so large. This means
1975 * the possibility of packet loss is relatively higher
1976 * than before. To avoid this scenario, we copy the
1977 * received data to a separate mbuf that does not use
1978 * a cluster, if possible.
1979 * XXX: it is better to copy the data after stripping
1980 * intermediate headers.
1981 */
1982 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1983 m->m_len <= MHLEN) {
1984 MGET(n, M_DONTWAIT, m->m_type);
1985 if (n != NULL) {
1986 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1987 bcopy(m->m_data, n->m_data,
1988 m->m_len);
1989 n->m_len = m->m_len;
1990 } else {
1991 m_free(n);
1992 n = NULL;
1993 }
1994 }
1995 }
1996 if (n != NULL ||
1997 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1998 if (last->inp_flags & INP_CONTROLOPTS)
1999 ip6_savecontrol(last, n, &opts);
2000 /* strip intermediate headers */
2001 m_adj(n, off);
2002 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2003 if (sbappendaddr_locked(
2004 &last->inp_socket->so_rcv,
2005 (struct sockaddr *)&fromsa, n, opts)
2006 == 0) {
2007 /* should notify about lost packet */
2008 m_freem(n);
2009 if (opts) {
2010 m_freem(opts);
2011 }
2012 SOCKBUF_UNLOCK(
2013 &last->inp_socket->so_rcv);
2014 } else
2015 sorwakeup_locked(last->inp_socket);
2016 opts = NULL;
2017 }
2018 INP_RUNLOCK(last);
2019 }
2020 last = in6p;
2021 }
2022 INP_INFO_RUNLOCK(&V_ripcbinfo);
2023 if (last != NULL) {
2024 if (last->inp_flags & INP_CONTROLOPTS)
2025 ip6_savecontrol(last, m, &opts);
2026 /* strip intermediate headers */
2027 m_adj(m, off);
2028
2029 /* avoid using mbuf clusters if possible (see above) */
2030 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2031 m->m_len <= MHLEN) {
2032 struct mbuf *n;
2033
2034 MGET(n, M_DONTWAIT, m->m_type);
2035 if (n != NULL) {
2036 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2037 bcopy(m->m_data, n->m_data, m->m_len);
2038 n->m_len = m->m_len;
2039
2040 m_freem(m);
2041 m = n;
2042 } else {
2043 m_freem(n);
2044 n = NULL;
2045 }
2046 }
2047 }
2048 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2049 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2050 (struct sockaddr *)&fromsa, m, opts) == 0) {
2051 m_freem(m);
2052 if (opts)
2053 m_freem(opts);
2054 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2055 } else
2056 sorwakeup_locked(last->inp_socket);
2057 INP_RUNLOCK(last);
2058 } else {
2059 m_freem(m);
2060 IP6STAT_DEC(ip6s_delivered);
2061 }
2062 return IPPROTO_DONE;
2063}
2064
2065/*
2066 * Reflect the ip6 packet back to the source.
2067 * OFF points to the icmp6 header, counted from the top of the mbuf.
2068 */
2069void
2070icmp6_reflect(struct mbuf *m, size_t off)
2071{
2072 struct ip6_hdr *ip6;
2073 struct icmp6_hdr *icmp6;
2074 struct in6_ifaddr *ia = NULL;
2075 int plen;
2076 int type, code;
2077 struct ifnet *outif = NULL;
2078 struct in6_addr origdst, src, *srcp = NULL;
2079
2080 /* too short to reflect */
2081 if (off < sizeof(struct ip6_hdr)) {
2082 nd6log((LOG_DEBUG,
2083 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2084 (u_long)off, (u_long)sizeof(struct ip6_hdr),
2085 __FILE__, __LINE__));
2086 goto bad;
2087 }
2088
2089 /*
2090 * If there are extra headers between IPv6 and ICMPv6, strip
2091 * off that header first.
2092 */
2093#ifdef DIAGNOSTIC
2094 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2095 panic("assumption failed in icmp6_reflect");
2096#endif
2097 if (off > sizeof(struct ip6_hdr)) {
2098 size_t l;
2099 struct ip6_hdr nip6;
2100
2101 l = off - sizeof(struct ip6_hdr);
2102 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2103 m_adj(m, l);
2104 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2105 if (m->m_len < l) {
2106 if ((m = m_pullup(m, l)) == NULL)
2107 return;
2108 }
2109 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2110 } else /* off == sizeof(struct ip6_hdr) */ {
2111 size_t l;
2112 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2113 if (m->m_len < l) {
2114 if ((m = m_pullup(m, l)) == NULL)
2115 return;
2116 }
2117 }
2118 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2119 ip6 = mtod(m, struct ip6_hdr *);
2120 ip6->ip6_nxt = IPPROTO_ICMPV6;
2121 icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2122 type = icmp6->icmp6_type; /* keep type for statistics */
2123 code = icmp6->icmp6_code; /* ditto. */
2124
2125 origdst = ip6->ip6_dst;
2126 /*
2127 * ip6_input() drops a packet if its src is multicast.
2128 * So, the src is never multicast.
2129 */
2130 ip6->ip6_dst = ip6->ip6_src;
2131
2132 /*
2133 * If the incoming packet was addressed directly to us (i.e. unicast),
2134 * use dst as the src for the reply.
2135 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2136 * (for example) when we encounter an error while forwarding procedure
2137 * destined to a duplicated address of ours.
2138 * Note that ip6_getdstifaddr() may fail if we are in an error handling
2139 * procedure of an outgoing packet of our own, in which case we need
2140 * to search in the ifaddr list.
2141 */
2142 if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2143 if ((ia = ip6_getdstifaddr(m))) {
2144 if (!(ia->ia6_flags &
2145 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2146 srcp = &ia->ia_addr.sin6_addr;
2147 } else {
2148 struct sockaddr_in6 d;
2149
2150 bzero(&d, sizeof(d));
2151 d.sin6_family = AF_INET6;
2152 d.sin6_len = sizeof(d);
2153 d.sin6_addr = origdst;
2154 ia = (struct in6_ifaddr *)
2155 ifa_ifwithaddr((struct sockaddr *)&d);
2156 if (ia &&
2157 !(ia->ia6_flags &
2158 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2159 srcp = &ia->ia_addr.sin6_addr;
2160 }
2161 }
2162 }
2163
2164 if ((srcp != NULL) &&
2165 (in6_addrscope(srcp) != in6_addrscope(&ip6->ip6_src)))
2166 srcp = NULL;
2167
2168 if (srcp == NULL) {
2169 int e;
2170 struct sockaddr_in6 sin6;
2171 struct route_in6 ro;
2172
2173 /*
2174 * This case matches to multicasts, our anycast, or unicasts
2175 * that we do not own. Select a source address based on the
2176 * source address of the erroneous packet.
2177 */
2178 bzero(&sin6, sizeof(sin6));
2179 sin6.sin6_family = AF_INET6;
2180 sin6.sin6_len = sizeof(sin6);
2181 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2182
2183 bzero(&ro, sizeof(ro));
2184 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
2185 if (ro.ro_rt)
2186 RTFREE(ro.ro_rt); /* XXX: we could use this */
2187 if (e) {
2188 char ip6buf[INET6_ADDRSTRLEN];
2189 nd6log((LOG_DEBUG,
2190 "icmp6_reflect: source can't be determined: "
2191 "dst=%s, error=%d\n",
2192 ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2193 goto bad;
2194 }
2195 srcp = &src;
2196 }
2197
2198 ip6->ip6_src = *srcp;
2199 ip6->ip6_flow = 0;
2200 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2201 ip6->ip6_vfc |= IPV6_VERSION;
2202 ip6->ip6_nxt = IPPROTO_ICMPV6;
2203 if (outif)
2204 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2205 else if (m->m_pkthdr.rcvif) {
2206 /* XXX: This may not be the outgoing interface */
2207 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2208 } else
2209 ip6->ip6_hlim = V_ip6_defhlim;
2210
2211 icmp6->icmp6_cksum = 0;
2212 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2213 sizeof(struct ip6_hdr), plen);
2214
2215 /*
2216 * XXX option handling
2217 */
2218
2219 m->m_flags &= ~(M_BCAST|M_MCAST);
2220
2221 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2222 if (outif)
2223 icmp6_ifoutstat_inc(outif, type, code);
2224
2225 if (ia != NULL)
2226 ifa_free(&ia->ia_ifa);
2227 return;
2228
2229 bad:
2230 if (ia != NULL)
2231 ifa_free(&ia->ia_ifa);
2232 m_freem(m);
2233 return;
2234}
2235
2236void
2237icmp6_fasttimo(void)
2238{
2239
2240 mld_fasttimo();
2241}
2242
2243void
2244icmp6_slowtimo(void)
2245{
2246
2247 mld_slowtimo();
2248}
2249
2250static const char *
2251icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2252 struct in6_addr *tgt6)
2253{
2254 static char buf[1024];
2255 char ip6bufs[INET6_ADDRSTRLEN];
2256 char ip6bufd[INET6_ADDRSTRLEN];
2257 char ip6buft[INET6_ADDRSTRLEN];
2258 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2259 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2260 ip6_sprintf(ip6buft, tgt6));
2261 return buf;
2262}
2263
2264void
2265icmp6_redirect_input(struct mbuf *m, int off)
2266{
2267 struct ifnet *ifp;
2268 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2269 struct nd_redirect *nd_rd;
2270 int icmp6len = ntohs(ip6->ip6_plen);
2271 char *lladdr = NULL;
2272 int lladdrlen = 0;
2273 u_char *redirhdr = NULL;
2274 int redirhdrlen = 0;
2275 struct rtentry *rt = NULL;
2276 int is_router;
2277 int is_onlink;
2278 struct in6_addr src6 = ip6->ip6_src;
2279 struct in6_addr redtgt6;
2280 struct in6_addr reddst6;
2281 union nd_opts ndopts;
2282 char ip6buf[INET6_ADDRSTRLEN];
2283
2284 if (!m)
2285 return;
2286
2287 ifp = m->m_pkthdr.rcvif;
2288
2289 if (!ifp)
2290 return;
2291
2292 /* XXX if we are router, we don't update route by icmp6 redirect */
2293 if (V_ip6_forwarding)
2294 goto freeit;
2295 if (!V_icmp6_rediraccept)
2296 goto freeit;
2297
2298#ifndef PULLDOWN_TEST
2299 IP6_EXTHDR_CHECK(m, off, icmp6len,);
2300 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2301#else
2302 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2303 if (nd_rd == NULL) {
2304 ICMP6STAT_INC(icp6s_tooshort);
2305 return;
2306 }
2307#endif
2308 redtgt6 = nd_rd->nd_rd_target;
2309 reddst6 = nd_rd->nd_rd_dst;
2310
2311 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2312 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2313 goto freeit;
2314 }
2315
2316 /* validation */
2317 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2318 nd6log((LOG_ERR,
2319 "ICMP6 redirect sent from %s rejected; "
2320 "must be from linklocal\n",
2321 ip6_sprintf(ip6buf, &src6)));
2322 goto bad;
2323 }
2324 if (ip6->ip6_hlim != 255) {
2325 nd6log((LOG_ERR,
2326 "ICMP6 redirect sent from %s rejected; "
2327 "hlim=%d (must be 255)\n",
2328 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2329 goto bad;
2330 }
2331 {
2332 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2333 struct sockaddr_in6 sin6;
2334 struct in6_addr *gw6;
2335
2336 bzero(&sin6, sizeof(sin6));
2337 sin6.sin6_family = AF_INET6;
2338 sin6.sin6_len = sizeof(struct sockaddr_in6);
2339 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2340 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2341 if (rt) {
2342 if (rt->rt_gateway == NULL ||
2343 rt->rt_gateway->sa_family != AF_INET6) {
2344 nd6log((LOG_ERR,
2345 "ICMP6 redirect rejected; no route "
2346 "with inet6 gateway found for redirect dst: %s\n",
2347 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2348 RTFREE_LOCKED(rt);
2349 goto bad;
2350 }
2351
2352 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2353 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2354 nd6log((LOG_ERR,
2355 "ICMP6 redirect rejected; "
2356 "not equal to gw-for-src=%s (must be same): "
2357 "%s\n",
2358 ip6_sprintf(ip6buf, gw6),
2359 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2360 RTFREE_LOCKED(rt);
2361 goto bad;
2362 }
2363 } else {
2364 nd6log((LOG_ERR,
2365 "ICMP6 redirect rejected; "
2366 "no route found for redirect dst: %s\n",
2367 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2368 goto bad;
2369 }
2370 RTFREE_LOCKED(rt);
2371 rt = NULL;
2372 }
2373 if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2374 nd6log((LOG_ERR,
2375 "ICMP6 redirect rejected; "
2376 "redirect dst must be unicast: %s\n",
2377 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2378 goto bad;
2379 }
2380
2381 is_router = is_onlink = 0;
2382 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2383 is_router = 1; /* router case */
2384 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2385 is_onlink = 1; /* on-link destination case */
2386 if (!is_router && !is_onlink) {
2387 nd6log((LOG_ERR,
2388 "ICMP6 redirect rejected; "
2389 "neither router case nor onlink case: %s\n",
2390 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2391 goto bad;
2392 }
2393 /* validation passed */
2394
2395 icmp6len -= sizeof(*nd_rd);
2396 nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2397 if (nd6_options(&ndopts) < 0) {
2398 nd6log((LOG_INFO, "icmp6_redirect_input: "
2399 "invalid ND option, rejected: %s\n",
2400 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2401 /* nd6_options have incremented stats */
2402 goto freeit;
2403 }
2404
2405 if (ndopts.nd_opts_tgt_lladdr) {
2406 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2407 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2408 }
2409
2410 if (ndopts.nd_opts_rh) {
2411 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2412 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2413 }
2414
2415 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2416 nd6log((LOG_INFO,
2417 "icmp6_redirect_input: lladdrlen mismatch for %s "
2418 "(if %d, icmp6 packet %d): %s\n",
2419 ip6_sprintf(ip6buf, &redtgt6),
2420 ifp->if_addrlen, lladdrlen - 2,
2421 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2422 goto bad;
2423 }
2424
2425 /* RFC 2461 8.3 */
2426 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2427 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2428
2429 if (!is_onlink) { /* better router case. perform rtredirect. */
2430 /* perform rtredirect */
2431 struct sockaddr_in6 sdst;
2432 struct sockaddr_in6 sgw;
2433 struct sockaddr_in6 ssrc;
2434
2435 bzero(&sdst, sizeof(sdst));
2436 bzero(&sgw, sizeof(sgw));
2437 bzero(&ssrc, sizeof(ssrc));
2438 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2439 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2440 sizeof(struct sockaddr_in6);
2441 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2442 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2443 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2444 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2445 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2446 (struct sockaddr *)&ssrc);
2447 }
2448 /* finally update cached route in each socket via pfctlinput */
2449 {
2450 struct sockaddr_in6 sdst;
2451
2452 bzero(&sdst, sizeof(sdst));
2453 sdst.sin6_family = AF_INET6;
2454 sdst.sin6_len = sizeof(struct sockaddr_in6);
2455 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2456 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2457#ifdef IPSEC
2458 key_sa_routechange((struct sockaddr *)&sdst);
2459#endif /* IPSEC */
2460 }
2461
2462 freeit:
2463 m_freem(m);
2464 return;
2465
2466 bad:
2467 ICMP6STAT_INC(icp6s_badredirect);
2468 m_freem(m);
2469}
2470
2471void
2472icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2473{
2474 struct ifnet *ifp; /* my outgoing interface */
2475 struct in6_addr *ifp_ll6;
2476 struct in6_addr *router_ll6;
2477 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
2478 struct mbuf *m = NULL; /* newly allocated one */
2479 struct ip6_hdr *ip6; /* m as struct ip6_hdr */
2480 struct nd_redirect *nd_rd;
2481 struct llentry *ln = NULL;
2482 size_t maxlen;
2483 u_char *p;
2484 struct ifnet *outif = NULL;
2485 struct sockaddr_in6 src_sa;
2486
2487 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2488
2489 /* if we are not router, we don't send icmp6 redirect */
2490 if (!V_ip6_forwarding)
2491 goto fail;
2492
2493 /* sanity check */
2494 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2495 goto fail;
2496
2497 /*
2498 * Address check:
2499 * the source address must identify a neighbor, and
2500 * the destination address must not be a multicast address
2501 * [RFC 2461, sec 8.2]
2502 */
2503 sip6 = mtod(m0, struct ip6_hdr *);
2504 bzero(&src_sa, sizeof(src_sa));
2505 src_sa.sin6_family = AF_INET6;
2506 src_sa.sin6_len = sizeof(src_sa);
2507 src_sa.sin6_addr = sip6->ip6_src;
2508 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2509 goto fail;
2510 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2511 goto fail; /* what should we do here? */
2512
2513 /* rate limit */
2514 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2515 goto fail;
2516
2517 /*
2518 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2519 * we almost always ask for an mbuf cluster for simplicity.
2520 * (MHLEN < IPV6_MMTU is almost always true)
2521 */
2522#if IPV6_MMTU >= MCLBYTES
2523# error assumption failed about IPV6_MMTU and MCLBYTES
2524#endif
2525 MGETHDR(m, M_DONTWAIT, MT_HEADER);
2526 if (m && IPV6_MMTU >= MHLEN)
2527 MCLGET(m, M_DONTWAIT);
2528 if (!m)
2529 goto fail;
2530 m->m_pkthdr.rcvif = NULL;
2531 m->m_len = 0;
2532 maxlen = M_TRAILINGSPACE(m);
2533 maxlen = min(IPV6_MMTU, maxlen);
2534 /* just for safety */
2535 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2536 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2537 goto fail;
2538 }
2539
2540 {
2541 /* get ip6 linklocal address for ifp(my outgoing interface). */
2542 struct in6_ifaddr *ia;
2543 if ((ia = in6ifa_ifpforlinklocal(ifp,
2544 IN6_IFF_NOTREADY|
2545 IN6_IFF_ANYCAST)) == NULL)
2546 goto fail;
2547 ifp_ll6 = &ia->ia_addr.sin6_addr;
2548 /* XXXRW: reference released prematurely. */
2549 ifa_free(&ia->ia_ifa);
2550 }
2551
2552 /* get ip6 linklocal address for the router. */
2553 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2554 struct sockaddr_in6 *sin6;
2555 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2556 router_ll6 = &sin6->sin6_addr;
2557 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2558 router_ll6 = (struct in6_addr *)NULL;
2559 } else
2560 router_ll6 = (struct in6_addr *)NULL;
2561
2562 /* ip6 */
2563 ip6 = mtod(m, struct ip6_hdr *);
2564 ip6->ip6_flow = 0;
2565 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2566 ip6->ip6_vfc |= IPV6_VERSION;
2567 /* ip6->ip6_plen will be set later */
2568 ip6->ip6_nxt = IPPROTO_ICMPV6;
2569 ip6->ip6_hlim = 255;
2570 /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2571 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2572 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2573
2574 /* ND Redirect */
2575 nd_rd = (struct nd_redirect *)(ip6 + 1);
2576 nd_rd->nd_rd_type = ND_REDIRECT;
2577 nd_rd->nd_rd_code = 0;
2578 nd_rd->nd_rd_reserved = 0;
2579 if (rt->rt_flags & RTF_GATEWAY) {
2580 /*
2581 * nd_rd->nd_rd_target must be a link-local address in
2582 * better router cases.
2583 */
2584 if (!router_ll6)
2585 goto fail;
2586 bcopy(router_ll6, &nd_rd->nd_rd_target,
2587 sizeof(nd_rd->nd_rd_target));
2588 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2589 sizeof(nd_rd->nd_rd_dst));
2590 } else {
2591 /* make sure redtgt == reddst */
2592 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2593 sizeof(nd_rd->nd_rd_target));
2594 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2595 sizeof(nd_rd->nd_rd_dst));
2596 }
2597
2598 p = (u_char *)(nd_rd + 1);
2599
2600 if (!router_ll6)
2601 goto nolladdropt;
2602
2603 {
2604 /* target lladdr option */
2605 int len;
2606 struct nd_opt_hdr *nd_opt;
2607 char *lladdr;
2608
2609 IF_AFDATA_LOCK(ifp);
2610 ln = nd6_lookup(router_ll6, 0, ifp);
2611 IF_AFDATA_UNLOCK(ifp);
2612 if (ln == NULL)
2613 goto nolladdropt;
2614
2615 len = sizeof(*nd_opt) + ifp->if_addrlen;
2616 len = (len + 7) & ~7; /* round by 8 */
2617 /* safety check */
2618 if (len + (p - (u_char *)ip6) > maxlen)
2619 goto nolladdropt;
2620
2621 if (ln->la_flags & LLE_VALID) {
2622 nd_opt = (struct nd_opt_hdr *)p;
2623 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2624 nd_opt->nd_opt_len = len >> 3;
2625 lladdr = (char *)(nd_opt + 1);
2626 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2627 p += len;
2628 }
2629 }
2630nolladdropt:
2631 if (ln != NULL)
2632 LLE_RUNLOCK(ln);
2633
2634 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2635
2636 /* just to be safe */
2637#ifdef M_DECRYPTED /*not openbsd*/
2638 if (m0->m_flags & M_DECRYPTED)
2639 goto noredhdropt;
2640#endif
2641 if (p - (u_char *)ip6 > maxlen)
2642 goto noredhdropt;
2643
2644 {
2645 /* redirected header option */
2646 int len;
2647 struct nd_opt_rd_hdr *nd_opt_rh;
2648
2649 /*
2650 * compute the maximum size for icmp6 redirect header option.
2651 * XXX room for auth header?
2652 */
2653 len = maxlen - (p - (u_char *)ip6);
2654 len &= ~7;
2655
2656 /* This is just for simplicity. */
2657 if (m0->m_pkthdr.len != m0->m_len) {
2658 if (m0->m_next) {
2659 m_freem(m0->m_next);
2660 m0->m_next = NULL;
2661 }
2662 m0->m_pkthdr.len = m0->m_len;
2663 }
2664
2665 /*
2666 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2667 * about padding/truncate rule for the original IP packet.
2668 * From the discussion on IPv6imp in Feb 1999,
2669 * the consensus was:
2670 * - "attach as much as possible" is the goal
2671 * - pad if not aligned (original size can be guessed by
2672 * original ip6 header)
2673 * Following code adds the padding if it is simple enough,
2674 * and truncates if not.
2675 */
2676 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2677 panic("assumption failed in %s:%d", __FILE__,
2678 __LINE__);
2679
2680 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2681 /* not enough room, truncate */
2682 m0->m_pkthdr.len = m0->m_len = len -
2683 sizeof(*nd_opt_rh);
2684 } else {
2685 /* enough room, pad or truncate */
2686 size_t extra;
2687
2688 extra = m0->m_pkthdr.len % 8;
2689 if (extra) {
2690 /* pad if easy enough, truncate if not */
2691 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2692 /* pad */
2693 m0->m_len += (8 - extra);
2694 m0->m_pkthdr.len += (8 - extra);
2695 } else {
2696 /* truncate */
2697 m0->m_pkthdr.len -= extra;
2698 m0->m_len -= extra;
2699 }
2700 }
2701 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2702 m0->m_pkthdr.len = m0->m_len = len -
2703 sizeof(*nd_opt_rh);
2704 }
2705
2706 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2707 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2708 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2709 nd_opt_rh->nd_opt_rh_len = len >> 3;
2710 p += sizeof(*nd_opt_rh);
2711 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2712
2713 /* connect m0 to m */
2714 m_tag_delete_chain(m0, NULL);
2715 m0->m_flags &= ~M_PKTHDR;
2716 m->m_next = m0;
2717 m->m_pkthdr.len = m->m_len + m0->m_len;
2718 m0 = NULL;
2719 }
2720noredhdropt:;
2721 if (m0) {
2722 m_freem(m0);
2723 m0 = NULL;
2724 }
2725
2726 /* XXX: clear embedded link IDs in the inner header */
2727 in6_clearscope(&sip6->ip6_src);
2728 in6_clearscope(&sip6->ip6_dst);
2729 in6_clearscope(&nd_rd->nd_rd_target);
2730 in6_clearscope(&nd_rd->nd_rd_dst);
2731
2732 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2733
2734 nd_rd->nd_rd_cksum = 0;
2735 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2736 sizeof(*ip6), ntohs(ip6->ip6_plen));
2737
2738 /* send the packet to outside... */
2739 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2740 if (outif) {
2741 icmp6_ifstat_inc(outif, ifs6_out_msg);
2742 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2743 }
2744 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2745
2746 return;
2747
2748fail:
2749 if (m)
2750 m_freem(m);
2751 if (m0)
2752 m_freem(m0);
2753}
2754
2755/*
2756 * ICMPv6 socket option processing.
2757 */
2758int
2759icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2760{
2761 int error = 0;
2762 int optlen;
2763 struct inpcb *inp = sotoinpcb(so);
2764 int level, op, optname;
2765
2766 if (sopt) {
2767 level = sopt->sopt_level;
2768 op = sopt->sopt_dir;
2769 optname = sopt->sopt_name;
2770 optlen = sopt->sopt_valsize;
2771 } else
2772 level = op = optname = optlen = 0;
2773
2774 if (level != IPPROTO_ICMPV6) {
2775 return EINVAL;
2776 }
2777
2778 switch (op) {
2779 case PRCO_SETOPT:
2780 switch (optname) {
2781 case ICMP6_FILTER:
2782 {
2783 struct icmp6_filter ic6f;
2784
2785 if (optlen != sizeof(ic6f)) {
2786 error = EMSGSIZE;
2787 break;
2788 }
2789 error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2790 if (error == 0) {
2791 INP_WLOCK(inp);
2792 *inp->in6p_icmp6filt = ic6f;
2793 INP_WUNLOCK(inp);
2794 }
2795 break;
2796 }
2797
2798 default:
2799 error = ENOPROTOOPT;
2800 break;
2801 }
2802 break;
2803
2804 case PRCO_GETOPT:
2805 switch (optname) {
2806 case ICMP6_FILTER:
2807 {
2808 struct icmp6_filter ic6f;
2809
2810 INP_RLOCK(inp);
2811 ic6f = *inp->in6p_icmp6filt;
2812 INP_RUNLOCK(inp);
2813 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2814 break;
2815 }
2816
2817 default:
2818 error = ENOPROTOOPT;
2819 break;
2820 }
2821 break;
2822 }
2823
2824 return (error);
2825}
2826
2827/*
2828 * Perform rate limit check.
2829 * Returns 0 if it is okay to send the icmp6 packet.
2830 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2831 * limitation.
2832 *
2833 * XXX per-destination/type check necessary?
2834 *
2835 * dst - not used at this moment
2836 * type - not used at this moment
2837 * code - not used at this moment
2838 */
2839static int
2840icmp6_ratelimit(const struct in6_addr *dst, const int type,
2841 const int code)
2842{
2843 int ret;
2844
2845 ret = 0; /* okay to send */
2846
2847 /* PPS limit */
2848 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2849 V_icmp6errppslim)) {
2850 /* The packet is subject to rate limit */
2851 ret++;
2852 }
2853
2854 return ret;
2855}
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