362#endif /* PFIL_HOOKS */
363
364 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
365
366 /*
367 * Check with the firewall...
368 */
369 if (ip6_fw_enable && ip6_fw_chk_ptr) {
370 u_short port = 0;
371 /* If ipfw says divert, we have to just drop packet */
372 /* use port as a dummy argument */
373 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) {
374 m_freem(m);
375 m = NULL;
376 }
377 if (!m)
378 return;
379 }
380
381 /*
382 * Check against address spoofing/corruption.
383 */
384 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
385 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
386 /*
387 * XXX: "badscope" is not very suitable for a multicast source.
388 */
389 ip6stat.ip6s_badscope++;
390 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
391 goto bad;
392 }
393 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) ||
394 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) &&
395 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
396 ip6stat.ip6s_badscope++;
397 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
398 goto bad;
399 }
400
401 /*
402 * The following check is not documented in specs. A malicious
403 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
404 * and bypass security checks (act as if it was from 127.0.0.1 by using
405 * IPv6 src ::ffff:127.0.0.1). Be cautious.
406 *
407 * This check chokes if we are in an SIIT cloud. As none of BSDs
408 * support IPv4-less kernel compilation, we cannot support SIIT
409 * environment at all. So, it makes more sense for us to reject any
410 * malicious packets for non-SIIT environment, than try to do a
411 * partical support for SIIT environment.
412 */
413 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
414 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
415 ip6stat.ip6s_badscope++;
416 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
417 goto bad;
418 }
419#if 0
420 /*
421 * Reject packets with IPv4 compatible addresses (auto tunnel).
422 *
423 * The code forbids auto tunnel relay case in RFC1933 (the check is
424 * stronger than RFC1933). We may want to re-enable it if mech-xx
425 * is revised to forbid relaying case.
426 */
427 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
428 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
429 ip6stat.ip6s_badscope++;
430 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
431 goto bad;
432 }
433#endif
434
435 /* drop packets if interface ID portion is already filled */
436 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
437 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) &&
438 ip6->ip6_src.s6_addr16[1]) {
439 ip6stat.ip6s_badscope++;
440 goto bad;
441 }
442 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) &&
443 ip6->ip6_dst.s6_addr16[1]) {
444 ip6stat.ip6s_badscope++;
445 goto bad;
446 }
447 }
448
449 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
450 ip6->ip6_src.s6_addr16[1]
451 = htons(m->m_pkthdr.rcvif->if_index);
452 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
453 ip6->ip6_dst.s6_addr16[1]
454 = htons(m->m_pkthdr.rcvif->if_index);
455
456#if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */
457 /*
458 * We use rt->rt_ifp to determine if the address is ours or not.
459 * If rt_ifp is lo0, the address is ours.
460 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0,
461 * so any address under fe80::%lo0/64 will be mistakenly considered
462 * local. The special case is supplied to handle the case properly
463 * by actually looking at interface addresses
464 * (using in6ifa_ifpwithaddr).
465 */
466 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 &&
467 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) {
468 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) {
469 icmp6_error(m, ICMP6_DST_UNREACH,
470 ICMP6_DST_UNREACH_ADDR, 0);
471 /* m is already freed */
472 return;
473 }
474
475 ours = 1;
476 deliverifp = m->m_pkthdr.rcvif;
477 goto hbhcheck;
478 }
479#endif
480
481 /*
482 * Multicast check
483 */
484 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
485 struct in6_multi *in6m = 0;
486
487 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
488 /*
489 * See if we belong to the destination multicast group on the
490 * arrival interface.
491 */
492 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
493 if (in6m)
494 ours = 1;
495 else if (!ip6_mrouter) {
496 ip6stat.ip6s_notmember++;
497 ip6stat.ip6s_cantforward++;
498 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
499 goto bad;
500 }
501 deliverifp = m->m_pkthdr.rcvif;
502 goto hbhcheck;
503 }
504
505 /*
506 * Unicast check
507 */
508 switch (ip6_ours_check_algorithm) {
509 default:
510 /*
511 * XXX: I intentionally broke our indentation rule here,
512 * since this switch-case is just for measurement and
513 * therefore should soon be removed.
514 */
515 if (ip6_forward_rt.ro_rt != NULL &&
516 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 &&
517 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
518 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
519 ip6stat.ip6s_forward_cachehit++;
520 else {
521 struct sockaddr_in6 *dst6;
522
523 if (ip6_forward_rt.ro_rt) {
524 /* route is down or destination is different */
525 ip6stat.ip6s_forward_cachemiss++;
526 RTFREE(ip6_forward_rt.ro_rt);
527 ip6_forward_rt.ro_rt = 0;
528 }
529
530 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
531 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
532 dst6->sin6_len = sizeof(struct sockaddr_in6);
533 dst6->sin6_family = AF_INET6;
534 dst6->sin6_addr = ip6->ip6_dst;
535#ifdef SCOPEDROUTING
536 ip6_forward_rt.ro_dst.sin6_scope_id =
537 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst);
538#endif
539
540 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING);
541 }
542
543#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
544
545 /*
546 * Accept the packet if the forwarding interface to the destination
547 * according to the routing table is the loopback interface,
548 * unless the associated route has a gateway.
549 * Note that this approach causes to accept a packet if there is a
550 * route to the loopback interface for the destination of the packet.
551 * But we think it's even useful in some situations, e.g. when using
552 * a special daemon which wants to intercept the packet.
553 *
554 * XXX: some OSes automatically make a cloned route for the destination
555 * of an outgoing packet. If the outgoing interface of the packet
556 * is a loopback one, the kernel would consider the packet to be
557 * accepted, even if we have no such address assinged on the interface.
558 * We check the cloned flag of the route entry to reject such cases,
559 * assuming that route entries for our own addresses are not made by
560 * cloning (it should be true because in6_addloop explicitly installs
561 * the host route). However, we might have to do an explicit check
562 * while it would be less efficient. Or, should we rather install a
563 * reject route for such a case?
564 */
565 if (ip6_forward_rt.ro_rt &&
566 (ip6_forward_rt.ro_rt->rt_flags &
567 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
568#ifdef RTF_WASCLONED
569 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) &&
570#endif
571#ifdef RTF_CLONED
572 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) &&
573#endif
574#if 0
575 /*
576 * The check below is redundant since the comparison of
577 * the destination and the key of the rtentry has
578 * already done through looking up the routing table.
579 */
580 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
581 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr)
582#endif
583 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
584 struct in6_ifaddr *ia6 =
585 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
586
587 /*
588 * record address information into m_aux.
589 */
590 (void)ip6_setdstifaddr(m, ia6);
591
592 /*
593 * packets to a tentative, duplicated, or somehow invalid
594 * address must not be accepted.
595 */
596 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
597 /* this address is ready */
598 ours = 1;
599 deliverifp = ia6->ia_ifp; /* correct? */
600 /* Count the packet in the ip address stats */
601 ia6->ia_ifa.if_ipackets++;
602 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
603 goto hbhcheck;
604 } else {
605 /* address is not ready, so discard the packet. */
606 nd6log((LOG_INFO,
607 "ip6_input: packet to an unready address %s->%s\n",
608 ip6_sprintf(&ip6->ip6_src),
609 ip6_sprintf(&ip6->ip6_dst)));
610
611 goto bad;
612 }
613 }
614 } /* XXX indentation (see above) */
615
616 /*
617 * FAITH(Firewall Aided Internet Translator)
618 */
619 if (ip6_keepfaith) {
620 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
621 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
622 /* XXX do we need more sanity checks? */
623 ours = 1;
624 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */
625 goto hbhcheck;
626 }
627 }
628
629 /*
630 * Now there is no reason to process the packet if it's not our own
631 * and we're not a router.
632 */
633 if (!ip6_forwarding) {
634 ip6stat.ip6s_cantforward++;
635 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
636 goto bad;
637 }
638
639 hbhcheck:
640 /*
641 * record address information into m_aux, if we don't have one yet.
642 * note that we are unable to record it, if the address is not listed
643 * as our interface address (e.g. multicast addresses, addresses
644 * within FAITH prefixes and such).
645 */
646 if (deliverifp && !ip6_getdstifaddr(m)) {
647 struct in6_ifaddr *ia6;
648
649 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
650 if (ia6) {
651 if (!ip6_setdstifaddr(m, ia6)) {
652 /*
653 * XXX maybe we should drop the packet here,
654 * as we could not provide enough information
655 * to the upper layers.
656 */
657 }
658 }
659 }
660
661 /*
662 * Process Hop-by-Hop options header if it's contained.
663 * m may be modified in ip6_hopopts_input().
664 * If a JumboPayload option is included, plen will also be modified.
665 */
666 plen = (u_int32_t)ntohs(ip6->ip6_plen);
667 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
668 struct ip6_hbh *hbh;
669
670 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
671#if 0 /*touches NULL pointer*/
672 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
673#endif
674 return; /* m have already been freed */
675 }
676
677 /* adjust pointer */
678 ip6 = mtod(m, struct ip6_hdr *);
679
680 /*
681 * if the payload length field is 0 and the next header field
682 * indicates Hop-by-Hop Options header, then a Jumbo Payload
683 * option MUST be included.
684 */
685 if (ip6->ip6_plen == 0 && plen == 0) {
686 /*
687 * Note that if a valid jumbo payload option is
688 * contained, ip6_hoptops_input() must set a valid
689 * (non-zero) payload length to the variable plen.
690 */
691 ip6stat.ip6s_badoptions++;
692 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
693 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
694 icmp6_error(m, ICMP6_PARAM_PROB,
695 ICMP6_PARAMPROB_HEADER,
696 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
697 return;
698 }
699#ifndef PULLDOWN_TEST
700 /* ip6_hopopts_input() ensures that mbuf is contiguous */
701 hbh = (struct ip6_hbh *)(ip6 + 1);
702#else
703 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
704 sizeof(struct ip6_hbh));
705 if (hbh == NULL) {
706 ip6stat.ip6s_tooshort++;
707 return;
708 }
709#endif
710 nxt = hbh->ip6h_nxt;
711
712 /*
713 * accept the packet if a router alert option is included
714 * and we act as an IPv6 router.
715 */
716 if (rtalert != ~0 && ip6_forwarding)
717 ours = 1;
718 } else
719 nxt = ip6->ip6_nxt;
720
721 /*
722 * Check that the amount of data in the buffers
723 * is as at least much as the IPv6 header would have us expect.
724 * Trim mbufs if longer than we expect.
725 * Drop packet if shorter than we expect.
726 */
727 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
728 ip6stat.ip6s_tooshort++;
729 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
730 goto bad;
731 }
732 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
733 if (m->m_len == m->m_pkthdr.len) {
734 m->m_len = sizeof(struct ip6_hdr) + plen;
735 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
736 } else
737 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
738 }
739
740 /*
741 * Forward if desirable.
742 */
743 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
744 /*
745 * If we are acting as a multicast router, all
746 * incoming multicast packets are passed to the
747 * kernel-level multicast forwarding function.
748 * The packet is returned (relatively) intact; if
749 * ip6_mforward() returns a non-zero value, the packet
750 * must be discarded, else it may be accepted below.
751 */
752 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
753 ip6stat.ip6s_cantforward++;
754 m_freem(m);
755 return;
756 }
757 if (!ours) {
758 m_freem(m);
759 return;
760 }
761 } else if (!ours) {
762 ip6_forward(m, 0);
763 return;
764 }
765
766 ip6 = mtod(m, struct ip6_hdr *);
767
768 /*
769 * Malicious party may be able to use IPv4 mapped addr to confuse
770 * tcp/udp stack and bypass security checks (act as if it was from
771 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
772 *
773 * For SIIT end node behavior, you may want to disable the check.
774 * However, you will become vulnerable to attacks using IPv4 mapped
775 * source.
776 */
777 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
778 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
779 ip6stat.ip6s_badscope++;
780 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
781 goto bad;
782 }
783
784 /*
785 * Tell launch routine the next header
786 */
787 ip6stat.ip6s_delivered++;
788 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
789 nest = 0;
790
791 while (nxt != IPPROTO_DONE) {
792 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
793 ip6stat.ip6s_toomanyhdr++;
794 goto bad;
795 }
796
797 /*
798 * protection against faulty packet - there should be
799 * more sanity checks in header chain processing.
800 */
801 if (m->m_pkthdr.len < off) {
802 ip6stat.ip6s_tooshort++;
803 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
804 goto bad;
805 }
806
807#if 0
808 /*
809 * do we need to do it for every header? yeah, other
810 * functions can play with it (like re-allocate and copy).
811 */
812 mhist = ip6_addaux(m);
813 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) {
814 hist = mtod(mhist, caddr_t) + mhist->m_len;
815 bcopy(&nxt, hist, sizeof(nxt));
816 mhist->m_len += sizeof(nxt);
817 } else {
818 ip6stat.ip6s_toomanyhdr++;
819 goto bad;
820 }
821#endif
822
823#ifdef IPSEC
824 /*
825 * enforce IPsec policy checking if we are seeing last header.
826 * note that we do not visit this with protocols with pcb layer
827 * code - like udp/tcp/raw ip.
828 */
829 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
830 ipsec6_in_reject(m, NULL)) {
831 ipsec6stat.in_polvio++;
832 goto bad;
833 }
834#endif
835
836 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
837 }
838 return;
839 bad:
840 m_freem(m);
841}
842
843/*
844 * set/grab in6_ifaddr correspond to IPv6 destination address.
845 * XXX backward compatibility wrapper
846 */
847static struct ip6aux *
848ip6_setdstifaddr(m, ia6)
849 struct mbuf *m;
850 struct in6_ifaddr *ia6;
851{
852 struct ip6aux *n;
853
854 n = ip6_addaux(m);
855 if (n)
856 n->ip6a_dstia6 = ia6;
857 return n; /* NULL if failed to set */
858}
859
860struct in6_ifaddr *
861ip6_getdstifaddr(m)
862 struct mbuf *m;
863{
864 struct ip6aux *n;
865
866 n = ip6_findaux(m);
867 if (n)
868 return n->ip6a_dstia6;
869 else
870 return NULL;
871}
872
873/*
874 * Hop-by-Hop options header processing. If a valid jumbo payload option is
875 * included, the real payload length will be stored in plenp.
876 */
877static int
878ip6_hopopts_input(plenp, rtalertp, mp, offp)
879 u_int32_t *plenp;
880 u_int32_t *rtalertp; /* XXX: should be stored more smart way */
881 struct mbuf **mp;
882 int *offp;
883{
884 struct mbuf *m = *mp;
885 int off = *offp, hbhlen;
886 struct ip6_hbh *hbh;
887 u_int8_t *opt;
888
889 /* validation of the length of the header */
890#ifndef PULLDOWN_TEST
891 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
892 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
893 hbhlen = (hbh->ip6h_len + 1) << 3;
894
895 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
896 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
897#else
898 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
899 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
900 if (hbh == NULL) {
901 ip6stat.ip6s_tooshort++;
902 return -1;
903 }
904 hbhlen = (hbh->ip6h_len + 1) << 3;
905 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
906 hbhlen);
907 if (hbh == NULL) {
908 ip6stat.ip6s_tooshort++;
909 return -1;
910 }
911#endif
912 off += hbhlen;
913 hbhlen -= sizeof(struct ip6_hbh);
914 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
915
916 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
917 hbhlen, rtalertp, plenp) < 0)
918 return(-1);
919
920 *offp = off;
921 *mp = m;
922 return(0);
923}
924
925/*
926 * Search header for all Hop-by-hop options and process each option.
927 * This function is separate from ip6_hopopts_input() in order to
928 * handle a case where the sending node itself process its hop-by-hop
929 * options header. In such a case, the function is called from ip6_output().
930 *
931 * The function assumes that hbh header is located right after the IPv6 header
932 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
933 * opthead + hbhlen is located in continuous memory region.
934 */
935int
936ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp)
937 struct mbuf *m;
938 u_int8_t *opthead;
939 int hbhlen;
940 u_int32_t *rtalertp;
941 u_int32_t *plenp;
942{
943 struct ip6_hdr *ip6;
944 int optlen = 0;
945 u_int8_t *opt = opthead;
946 u_int16_t rtalert_val;
947 u_int32_t jumboplen;
948 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
949
950 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
951 switch (*opt) {
952 case IP6OPT_PAD1:
953 optlen = 1;
954 break;
955 case IP6OPT_PADN:
956 if (hbhlen < IP6OPT_MINLEN) {
957 ip6stat.ip6s_toosmall++;
958 goto bad;
959 }
960 optlen = *(opt + 1) + 2;
961 break;
962 case IP6OPT_RTALERT:
963 /* XXX may need check for alignment */
964 if (hbhlen < IP6OPT_RTALERT_LEN) {
965 ip6stat.ip6s_toosmall++;
966 goto bad;
967 }
968 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
969 /* XXX stat */
970 icmp6_error(m, ICMP6_PARAM_PROB,
971 ICMP6_PARAMPROB_HEADER,
972 erroff + opt + 1 - opthead);
973 return(-1);
974 }
975 optlen = IP6OPT_RTALERT_LEN;
976 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
977 *rtalertp = ntohs(rtalert_val);
978 break;
979 case IP6OPT_JUMBO:
980 /* XXX may need check for alignment */
981 if (hbhlen < IP6OPT_JUMBO_LEN) {
982 ip6stat.ip6s_toosmall++;
983 goto bad;
984 }
985 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
986 /* XXX stat */
987 icmp6_error(m, ICMP6_PARAM_PROB,
988 ICMP6_PARAMPROB_HEADER,
989 erroff + opt + 1 - opthead);
990 return(-1);
991 }
992 optlen = IP6OPT_JUMBO_LEN;
993
994 /*
995 * IPv6 packets that have non 0 payload length
996 * must not contain a jumbo payload option.
997 */
998 ip6 = mtod(m, struct ip6_hdr *);
999 if (ip6->ip6_plen) {
1000 ip6stat.ip6s_badoptions++;
1001 icmp6_error(m, ICMP6_PARAM_PROB,
1002 ICMP6_PARAMPROB_HEADER,
1003 erroff + opt - opthead);
1004 return(-1);
1005 }
1006
1007 /*
1008 * We may see jumbolen in unaligned location, so
1009 * we'd need to perform bcopy().
1010 */
1011 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1012 jumboplen = (u_int32_t)htonl(jumboplen);
1013
1014#if 1
1015 /*
1016 * if there are multiple jumbo payload options,
1017 * *plenp will be non-zero and the packet will be
1018 * rejected.
1019 * the behavior may need some debate in ipngwg -
1020 * multiple options does not make sense, however,
1021 * there's no explicit mention in specification.
1022 */
1023 if (*plenp != 0) {
1024 ip6stat.ip6s_badoptions++;
1025 icmp6_error(m, ICMP6_PARAM_PROB,
1026 ICMP6_PARAMPROB_HEADER,
1027 erroff + opt + 2 - opthead);
1028 return(-1);
1029 }
1030#endif
1031
1032 /*
1033 * jumbo payload length must be larger than 65535.
1034 */
1035 if (jumboplen <= IPV6_MAXPACKET) {
1036 ip6stat.ip6s_badoptions++;
1037 icmp6_error(m, ICMP6_PARAM_PROB,
1038 ICMP6_PARAMPROB_HEADER,
1039 erroff + opt + 2 - opthead);
1040 return(-1);
1041 }
1042 *plenp = jumboplen;
1043
1044 break;
1045 default: /* unknown option */
1046 if (hbhlen < IP6OPT_MINLEN) {
1047 ip6stat.ip6s_toosmall++;
1048 goto bad;
1049 }
1050 optlen = ip6_unknown_opt(opt, m,
1051 erroff + opt - opthead);
1052 if (optlen == -1)
1053 return(-1);
1054 optlen += 2;
1055 break;
1056 }
1057 }
1058
1059 return(0);
1060
1061 bad:
1062 m_freem(m);
1063 return(-1);
1064}
1065
1066/*
1067 * Unknown option processing.
1068 * The third argument `off' is the offset from the IPv6 header to the option,
1069 * which is necessary if the IPv6 header the and option header and IPv6 header
1070 * is not continuous in order to return an ICMPv6 error.
1071 */
1072int
1073ip6_unknown_opt(optp, m, off)
1074 u_int8_t *optp;
1075 struct mbuf *m;
1076 int off;
1077{
1078 struct ip6_hdr *ip6;
1079
1080 switch (IP6OPT_TYPE(*optp)) {
1081 case IP6OPT_TYPE_SKIP: /* ignore the option */
1082 return((int)*(optp + 1));
1083 case IP6OPT_TYPE_DISCARD: /* silently discard */
1084 m_freem(m);
1085 return(-1);
1086 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1087 ip6stat.ip6s_badoptions++;
1088 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1089 return(-1);
1090 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1091 ip6stat.ip6s_badoptions++;
1092 ip6 = mtod(m, struct ip6_hdr *);
1093 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1094 (m->m_flags & (M_BCAST|M_MCAST)))
1095 m_freem(m);
1096 else
1097 icmp6_error(m, ICMP6_PARAM_PROB,
1098 ICMP6_PARAMPROB_OPTION, off);
1099 return(-1);
1100 }
1101
1102 m_freem(m); /* XXX: NOTREACHED */
1103 return(-1);
1104}
1105
1106/*
1107 * Create the "control" list for this pcb.
1108 * The function will not modify mbuf chain at all.
1109 *
1110 * with KAME mbuf chain restriction:
1111 * The routine will be called from upper layer handlers like tcp6_input().
1112 * Thus the routine assumes that the caller (tcp6_input) have already
1113 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1114 * very first mbuf on the mbuf chain.
1115 */
1116void
1117ip6_savecontrol(in6p, mp, ip6, m)
1118 struct inpcb *in6p;
1119 struct mbuf **mp;
1120 struct ip6_hdr *ip6;
1121 struct mbuf *m;
1122{
1123#if __FreeBSD_version >= 500000
1124 struct thread *td = curthread; /* XXX */
1125#else
1126 struct proc *td = curproc; /* XXX */
1127#endif
1128 int privileged = 0;
1129 int rthdr_exist = 0;
1130
1131
1132 if (td && !suser(td))
1133 privileged++;
1134
1135#ifdef SO_TIMESTAMP
1136 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) {
1137 struct timeval tv;
1138
1139 microtime(&tv);
1140 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1141 SCM_TIMESTAMP, SOL_SOCKET);
1142 if (*mp) {
1143 mp = &(*mp)->m_next;
1144 }
1145 }
1146#endif
1147
1148 /* RFC 2292 sec. 5 */
1149 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
1150 struct in6_pktinfo pi6;
1151 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1152 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr))
1153 pi6.ipi6_addr.s6_addr16[1] = 0;
1154 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif)
1155 ? m->m_pkthdr.rcvif->if_index
1156 : 0;
1157 *mp = sbcreatecontrol((caddr_t) &pi6,
1158 sizeof(struct in6_pktinfo), IPV6_PKTINFO,
1159 IPPROTO_IPV6);
1160 if (*mp)
1161 mp = &(*mp)->m_next;
1162 }
1163
1164 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) {
1165 int hlim = ip6->ip6_hlim & 0xff;
1166 *mp = sbcreatecontrol((caddr_t) &hlim,
1167 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6);
1168 if (*mp)
1169 mp = &(*mp)->m_next;
1170 }
1171
1172 /*
1173 * IPV6_HOPOPTS socket option. We require super-user privilege
1174 * for the option, but it might be too strict, since there might
1175 * be some hop-by-hop options which can be returned to normal user.
1176 * See RFC 2292 section 6.
1177 */
1178 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) {
1179 /*
1180 * Check if a hop-by-hop options header is contatined in the
1181 * received packet, and if so, store the options as ancillary
1182 * data. Note that a hop-by-hop options header must be
1183 * just after the IPv6 header, which fact is assured through
1184 * the IPv6 input processing.
1185 */
1186 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1187 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1188 struct ip6_hbh *hbh;
1189 int hbhlen = 0;
1190#ifdef PULLDOWN_TEST
1191 struct mbuf *ext;
1192#endif
1193
1194#ifndef PULLDOWN_TEST
1195 hbh = (struct ip6_hbh *)(ip6 + 1);
1196 hbhlen = (hbh->ip6h_len + 1) << 3;
1197#else
1198 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1199 ip6->ip6_nxt);
1200 if (ext == NULL) {
1201 ip6stat.ip6s_tooshort++;
1202 return;
1203 }
1204 hbh = mtod(ext, struct ip6_hbh *);
1205 hbhlen = (hbh->ip6h_len + 1) << 3;
1206 if (hbhlen != ext->m_len) {
1207 m_freem(ext);
1208 ip6stat.ip6s_tooshort++;
1209 return;
1210 }
1211#endif
1212
1213 /*
1214 * XXX: We copy whole the header even if a jumbo
1215 * payload option is included, which option is to
1216 * be removed before returning in the RFC 2292.
1217 * Note: this constraint is removed in 2292bis.
1218 */
1219 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1220 IPV6_HOPOPTS, IPPROTO_IPV6);
1221 if (*mp)
1222 mp = &(*mp)->m_next;
1223#ifdef PULLDOWN_TEST
1224 m_freem(ext);
1225#endif
1226 }
1227 }
1228
1229 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */
1230 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) {
1231 int proto, off, nxt;
1232
1233 /*
1234 * go through the header chain to see if a routing header is
1235 * contained in the packet. We need this information to store
1236 * destination options headers (if any) properly.
1237 * XXX: performance issue. We should record this info when
1238 * processing extension headers in incoming routine.
1239 * (todo) use m_aux?
1240 */
1241 proto = IPPROTO_IPV6;
1242 off = 0;
1243 nxt = -1;
1244 while (1) {
1245 int newoff;
1246
1247 newoff = ip6_nexthdr(m, off, proto, &nxt);
1248 if (newoff < 0)
1249 break;
1250 if (newoff < off) /* invalid, check for safety */
1251 break;
1252 if ((proto = nxt) == IPPROTO_ROUTING) {
1253 rthdr_exist = 1;
1254 break;
1255 }
1256 off = newoff;
1257 }
1258 }
1259
1260 if ((in6p->in6p_flags &
1261 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) {
1262 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1263 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1264
1265 /*
1266 * Search for destination options headers or routing
1267 * header(s) through the header chain, and stores each
1268 * header as ancillary data.
1269 * Note that the order of the headers remains in
1270 * the chain of ancillary data.
1271 */
1272 while (1) { /* is explicit loop prevention necessary? */
1273 struct ip6_ext *ip6e = NULL;
1274 int elen;
1275#ifdef PULLDOWN_TEST
1276 struct mbuf *ext = NULL;
1277#endif
1278
1279 /*
1280 * if it is not an extension header, don't try to
1281 * pull it from the chain.
1282 */
1283 switch (nxt) {
1284 case IPPROTO_DSTOPTS:
1285 case IPPROTO_ROUTING:
1286 case IPPROTO_HOPOPTS:
1287 case IPPROTO_AH: /* is it possible? */
1288 break;
1289 default:
1290 goto loopend;
1291 }
1292
1293#ifndef PULLDOWN_TEST
1294 if (off + sizeof(*ip6e) > m->m_len)
1295 goto loopend;
1296 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1297 if (nxt == IPPROTO_AH)
1298 elen = (ip6e->ip6e_len + 2) << 2;
1299 else
1300 elen = (ip6e->ip6e_len + 1) << 3;
1301 if (off + elen > m->m_len)
1302 goto loopend;
1303#else
1304 ext = ip6_pullexthdr(m, off, nxt);
1305 if (ext == NULL) {
1306 ip6stat.ip6s_tooshort++;
1307 return;
1308 }
1309 ip6e = mtod(ext, struct ip6_ext *);
1310 if (nxt == IPPROTO_AH)
1311 elen = (ip6e->ip6e_len + 2) << 2;
1312 else
1313 elen = (ip6e->ip6e_len + 1) << 3;
1314 if (elen != ext->m_len) {
1315 m_freem(ext);
1316 ip6stat.ip6s_tooshort++;
1317 return;
1318 }
1319#endif
1320
1321 switch (nxt) {
1322 case IPPROTO_DSTOPTS:
1323 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0)
1324 break;
1325
1326 /*
1327 * We also require super-user privilege for
1328 * the option.
1329 * See the comments on IN6_HOPOPTS.
1330 */
1331 if (!privileged)
1332 break;
1333
1334 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1335 IPV6_DSTOPTS,
1336 IPPROTO_IPV6);
1337 if (*mp)
1338 mp = &(*mp)->m_next;
1339 break;
1340 case IPPROTO_ROUTING:
1341 if (!in6p->in6p_flags & IN6P_RTHDR)
1342 break;
1343
1344 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1345 IPV6_RTHDR,
1346 IPPROTO_IPV6);
1347 if (*mp)
1348 mp = &(*mp)->m_next;
1349 break;
1350 case IPPROTO_HOPOPTS:
1351 case IPPROTO_AH: /* is it possible? */
1352 break;
1353
1354 default:
1355 /*
1356 * other cases have been filtered in the above.
1357 * none will visit this case. here we supply
1358 * the code just in case (nxt overwritten or
1359 * other cases).
1360 */
1361#ifdef PULLDOWN_TEST
1362 m_freem(ext);
1363#endif
1364 goto loopend;
1365
1366 }
1367
1368 /* proceed with the next header. */
1369 off += elen;
1370 nxt = ip6e->ip6e_nxt;
1371 ip6e = NULL;
1372#ifdef PULLDOWN_TEST
1373 m_freem(ext);
1374 ext = NULL;
1375#endif
1376 }
1377 loopend:
1378 ;
1379 }
1380
1381}
1382
1383#ifdef PULLDOWN_TEST
1384/*
1385 * pull single extension header from mbuf chain. returns single mbuf that
1386 * contains the result, or NULL on error.
1387 */
1388static struct mbuf *
1389ip6_pullexthdr(m, off, nxt)
1390 struct mbuf *m;
1391 size_t off;
1392 int nxt;
1393{
1394 struct ip6_ext ip6e;
1395 size_t elen;
1396 struct mbuf *n;
1397
1398#ifdef DIAGNOSTIC
1399 switch (nxt) {
1400 case IPPROTO_DSTOPTS:
1401 case IPPROTO_ROUTING:
1402 case IPPROTO_HOPOPTS:
1403 case IPPROTO_AH: /* is it possible? */
1404 break;
1405 default:
1406 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1407 }
1408#endif
1409
1410 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1411 if (nxt == IPPROTO_AH)
1412 elen = (ip6e.ip6e_len + 2) << 2;
1413 else
1414 elen = (ip6e.ip6e_len + 1) << 3;
1415
1416 MGET(n, M_DONTWAIT, MT_DATA);
1417 if (n && elen >= MLEN) {
1418 MCLGET(n, M_DONTWAIT);
1419 if ((n->m_flags & M_EXT) == 0) {
1420 m_free(n);
1421 n = NULL;
1422 }
1423 }
1424 if (!n)
1425 return NULL;
1426
1427 n->m_len = 0;
1428 if (elen >= M_TRAILINGSPACE(n)) {
1429 m_free(n);
1430 return NULL;
1431 }
1432
1433 m_copydata(m, off, elen, mtod(n, caddr_t));
1434 n->m_len = elen;
1435 return n;
1436}
1437#endif
1438
1439/*
1440 * Get pointer to the previous header followed by the header
1441 * currently processed.
1442 * XXX: This function supposes that
1443 * M includes all headers,
1444 * the next header field and the header length field of each header
1445 * are valid, and
1446 * the sum of each header length equals to OFF.
1447 * Because of these assumptions, this function must be called very
1448 * carefully. Moreover, it will not be used in the near future when
1449 * we develop `neater' mechanism to process extension headers.
1450 */
1451char *
1452ip6_get_prevhdr(m, off)
1453 struct mbuf *m;
1454 int off;
1455{
1456 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1457
1458 if (off == sizeof(struct ip6_hdr))
1459 return(&ip6->ip6_nxt);
1460 else {
1461 int len, nxt;
1462 struct ip6_ext *ip6e = NULL;
1463
1464 nxt = ip6->ip6_nxt;
1465 len = sizeof(struct ip6_hdr);
1466 while (len < off) {
1467 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1468
1469 switch (nxt) {
1470 case IPPROTO_FRAGMENT:
1471 len += sizeof(struct ip6_frag);
1472 break;
1473 case IPPROTO_AH:
1474 len += (ip6e->ip6e_len + 2) << 2;
1475 break;
1476 default:
1477 len += (ip6e->ip6e_len + 1) << 3;
1478 break;
1479 }
1480 nxt = ip6e->ip6e_nxt;
1481 }
1482 if (ip6e)
1483 return(&ip6e->ip6e_nxt);
1484 else
1485 return NULL;
1486 }
1487}
1488
1489/*
1490 * get next header offset. m will be retained.
1491 */
1492int
1493ip6_nexthdr(m, off, proto, nxtp)
1494 struct mbuf *m;
1495 int off;
1496 int proto;
1497 int *nxtp;
1498{
1499 struct ip6_hdr ip6;
1500 struct ip6_ext ip6e;
1501 struct ip6_frag fh;
1502
1503 /* just in case */
1504 if (m == NULL)
1505 panic("ip6_nexthdr: m == NULL");
1506 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1507 return -1;
1508
1509 switch (proto) {
1510 case IPPROTO_IPV6:
1511 if (m->m_pkthdr.len < off + sizeof(ip6))
1512 return -1;
1513 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1514 if (nxtp)
1515 *nxtp = ip6.ip6_nxt;
1516 off += sizeof(ip6);
1517 return off;
1518
1519 case IPPROTO_FRAGMENT:
1520 /*
1521 * terminate parsing if it is not the first fragment,
1522 * it does not make sense to parse through it.
1523 */
1524 if (m->m_pkthdr.len < off + sizeof(fh))
1525 return -1;
1526 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1527 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0)
1528 return -1;
1529 if (nxtp)
1530 *nxtp = fh.ip6f_nxt;
1531 off += sizeof(struct ip6_frag);
1532 return off;
1533
1534 case IPPROTO_AH:
1535 if (m->m_pkthdr.len < off + sizeof(ip6e))
1536 return -1;
1537 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1538 if (nxtp)
1539 *nxtp = ip6e.ip6e_nxt;
1540 off += (ip6e.ip6e_len + 2) << 2;
1541 return off;
1542
1543 case IPPROTO_HOPOPTS:
1544 case IPPROTO_ROUTING:
1545 case IPPROTO_DSTOPTS:
1546 if (m->m_pkthdr.len < off + sizeof(ip6e))
1547 return -1;
1548 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1549 if (nxtp)
1550 *nxtp = ip6e.ip6e_nxt;
1551 off += (ip6e.ip6e_len + 1) << 3;
1552 return off;
1553
1554 case IPPROTO_NONE:
1555 case IPPROTO_ESP:
1556 case IPPROTO_IPCOMP:
1557 /* give up */
1558 return -1;
1559
1560 default:
1561 return -1;
1562 }
1563
1564 return -1;
1565}
1566
1567/*
1568 * get offset for the last header in the chain. m will be kept untainted.
1569 */
1570int
1571ip6_lasthdr(m, off, proto, nxtp)
1572 struct mbuf *m;
1573 int off;
1574 int proto;
1575 int *nxtp;
1576{
1577 int newoff;
1578 int nxt;
1579
1580 if (!nxtp) {
1581 nxt = -1;
1582 nxtp = &nxt;
1583 }
1584 while (1) {
1585 newoff = ip6_nexthdr(m, off, proto, nxtp);
1586 if (newoff < 0)
1587 return off;
1588 else if (newoff < off)
1589 return -1; /* invalid */
1590 else if (newoff == off)
1591 return newoff;
1592
1593 off = newoff;
1594 proto = *nxtp;
1595 }
1596}
1597
1598struct ip6aux *
1599ip6_addaux(m)
1600 struct mbuf *m;
1601{
1602 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1603 if (!tag) {
1604 tag = m_tag_get(PACKET_TAG_IPV6_INPUT,
1605 sizeof (struct ip6aux),
1606 M_NOWAIT);
1607 if (tag)
1608 m_tag_prepend(m, tag);
1609 }
1610 if (tag)
1611 bzero(tag+1, sizeof (struct ip6aux));
1612 return tag ? (struct ip6aux*)(tag+1) : NULL;
1613}
1614
1615struct ip6aux *
1616ip6_findaux(m)
1617 struct mbuf *m;
1618{
1619 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1620 return tag ? (struct ip6aux*)(tag+1) : NULL;
1621}
1622
1623void
1624ip6_delaux(m)
1625 struct mbuf *m;
1626{
1627 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1628 if (tag)
1629 m_tag_delete(m, tag);
1630}
1631
1632/*
1633 * System control for IP6
1634 */
1635
1636u_char inet6ctlerrmap[PRC_NCMDS] = {
1637 0, 0, 0, 0,
1638 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1639 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1640 EMSGSIZE, EHOSTUNREACH, 0, 0,
1641 0, 0, 0, 0,
1642 ENOPROTOOPT
1643};
| 355#endif /* PFIL_HOOKS */
356
357 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
358
359 /*
360 * Check with the firewall...
361 */
362 if (ip6_fw_enable && ip6_fw_chk_ptr) {
363 u_short port = 0;
364 /* If ipfw says divert, we have to just drop packet */
365 /* use port as a dummy argument */
366 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) {
367 m_freem(m);
368 m = NULL;
369 }
370 if (!m)
371 return;
372 }
373
374 /*
375 * Check against address spoofing/corruption.
376 */
377 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
378 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
379 /*
380 * XXX: "badscope" is not very suitable for a multicast source.
381 */
382 ip6stat.ip6s_badscope++;
383 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
384 goto bad;
385 }
386 if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) ||
387 IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) &&
388 (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
389 ip6stat.ip6s_badscope++;
390 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
391 goto bad;
392 }
393
394 /*
395 * The following check is not documented in specs. A malicious
396 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
397 * and bypass security checks (act as if it was from 127.0.0.1 by using
398 * IPv6 src ::ffff:127.0.0.1). Be cautious.
399 *
400 * This check chokes if we are in an SIIT cloud. As none of BSDs
401 * support IPv4-less kernel compilation, we cannot support SIIT
402 * environment at all. So, it makes more sense for us to reject any
403 * malicious packets for non-SIIT environment, than try to do a
404 * partical support for SIIT environment.
405 */
406 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
407 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
408 ip6stat.ip6s_badscope++;
409 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
410 goto bad;
411 }
412#if 0
413 /*
414 * Reject packets with IPv4 compatible addresses (auto tunnel).
415 *
416 * The code forbids auto tunnel relay case in RFC1933 (the check is
417 * stronger than RFC1933). We may want to re-enable it if mech-xx
418 * is revised to forbid relaying case.
419 */
420 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
421 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
422 ip6stat.ip6s_badscope++;
423 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
424 goto bad;
425 }
426#endif
427
428 /* drop packets if interface ID portion is already filled */
429 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
430 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) &&
431 ip6->ip6_src.s6_addr16[1]) {
432 ip6stat.ip6s_badscope++;
433 goto bad;
434 }
435 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) &&
436 ip6->ip6_dst.s6_addr16[1]) {
437 ip6stat.ip6s_badscope++;
438 goto bad;
439 }
440 }
441
442 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
443 ip6->ip6_src.s6_addr16[1]
444 = htons(m->m_pkthdr.rcvif->if_index);
445 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
446 ip6->ip6_dst.s6_addr16[1]
447 = htons(m->m_pkthdr.rcvif->if_index);
448
449#if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */
450 /*
451 * We use rt->rt_ifp to determine if the address is ours or not.
452 * If rt_ifp is lo0, the address is ours.
453 * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0,
454 * so any address under fe80::%lo0/64 will be mistakenly considered
455 * local. The special case is supplied to handle the case properly
456 * by actually looking at interface addresses
457 * (using in6ifa_ifpwithaddr).
458 */
459 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 &&
460 IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) {
461 if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) {
462 icmp6_error(m, ICMP6_DST_UNREACH,
463 ICMP6_DST_UNREACH_ADDR, 0);
464 /* m is already freed */
465 return;
466 }
467
468 ours = 1;
469 deliverifp = m->m_pkthdr.rcvif;
470 goto hbhcheck;
471 }
472#endif
473
474 /*
475 * Multicast check
476 */
477 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
478 struct in6_multi *in6m = 0;
479
480 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
481 /*
482 * See if we belong to the destination multicast group on the
483 * arrival interface.
484 */
485 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
486 if (in6m)
487 ours = 1;
488 else if (!ip6_mrouter) {
489 ip6stat.ip6s_notmember++;
490 ip6stat.ip6s_cantforward++;
491 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
492 goto bad;
493 }
494 deliverifp = m->m_pkthdr.rcvif;
495 goto hbhcheck;
496 }
497
498 /*
499 * Unicast check
500 */
501 switch (ip6_ours_check_algorithm) {
502 default:
503 /*
504 * XXX: I intentionally broke our indentation rule here,
505 * since this switch-case is just for measurement and
506 * therefore should soon be removed.
507 */
508 if (ip6_forward_rt.ro_rt != NULL &&
509 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 &&
510 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
511 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
512 ip6stat.ip6s_forward_cachehit++;
513 else {
514 struct sockaddr_in6 *dst6;
515
516 if (ip6_forward_rt.ro_rt) {
517 /* route is down or destination is different */
518 ip6stat.ip6s_forward_cachemiss++;
519 RTFREE(ip6_forward_rt.ro_rt);
520 ip6_forward_rt.ro_rt = 0;
521 }
522
523 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
524 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
525 dst6->sin6_len = sizeof(struct sockaddr_in6);
526 dst6->sin6_family = AF_INET6;
527 dst6->sin6_addr = ip6->ip6_dst;
528#ifdef SCOPEDROUTING
529 ip6_forward_rt.ro_dst.sin6_scope_id =
530 in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst);
531#endif
532
533 rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING);
534 }
535
536#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
537
538 /*
539 * Accept the packet if the forwarding interface to the destination
540 * according to the routing table is the loopback interface,
541 * unless the associated route has a gateway.
542 * Note that this approach causes to accept a packet if there is a
543 * route to the loopback interface for the destination of the packet.
544 * But we think it's even useful in some situations, e.g. when using
545 * a special daemon which wants to intercept the packet.
546 *
547 * XXX: some OSes automatically make a cloned route for the destination
548 * of an outgoing packet. If the outgoing interface of the packet
549 * is a loopback one, the kernel would consider the packet to be
550 * accepted, even if we have no such address assinged on the interface.
551 * We check the cloned flag of the route entry to reject such cases,
552 * assuming that route entries for our own addresses are not made by
553 * cloning (it should be true because in6_addloop explicitly installs
554 * the host route). However, we might have to do an explicit check
555 * while it would be less efficient. Or, should we rather install a
556 * reject route for such a case?
557 */
558 if (ip6_forward_rt.ro_rt &&
559 (ip6_forward_rt.ro_rt->rt_flags &
560 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
561#ifdef RTF_WASCLONED
562 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) &&
563#endif
564#ifdef RTF_CLONED
565 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) &&
566#endif
567#if 0
568 /*
569 * The check below is redundant since the comparison of
570 * the destination and the key of the rtentry has
571 * already done through looking up the routing table.
572 */
573 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
574 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr)
575#endif
576 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
577 struct in6_ifaddr *ia6 =
578 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
579
580 /*
581 * record address information into m_aux.
582 */
583 (void)ip6_setdstifaddr(m, ia6);
584
585 /*
586 * packets to a tentative, duplicated, or somehow invalid
587 * address must not be accepted.
588 */
589 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
590 /* this address is ready */
591 ours = 1;
592 deliverifp = ia6->ia_ifp; /* correct? */
593 /* Count the packet in the ip address stats */
594 ia6->ia_ifa.if_ipackets++;
595 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
596 goto hbhcheck;
597 } else {
598 /* address is not ready, so discard the packet. */
599 nd6log((LOG_INFO,
600 "ip6_input: packet to an unready address %s->%s\n",
601 ip6_sprintf(&ip6->ip6_src),
602 ip6_sprintf(&ip6->ip6_dst)));
603
604 goto bad;
605 }
606 }
607 } /* XXX indentation (see above) */
608
609 /*
610 * FAITH(Firewall Aided Internet Translator)
611 */
612 if (ip6_keepfaith) {
613 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
614 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
615 /* XXX do we need more sanity checks? */
616 ours = 1;
617 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */
618 goto hbhcheck;
619 }
620 }
621
622 /*
623 * Now there is no reason to process the packet if it's not our own
624 * and we're not a router.
625 */
626 if (!ip6_forwarding) {
627 ip6stat.ip6s_cantforward++;
628 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
629 goto bad;
630 }
631
632 hbhcheck:
633 /*
634 * record address information into m_aux, if we don't have one yet.
635 * note that we are unable to record it, if the address is not listed
636 * as our interface address (e.g. multicast addresses, addresses
637 * within FAITH prefixes and such).
638 */
639 if (deliverifp && !ip6_getdstifaddr(m)) {
640 struct in6_ifaddr *ia6;
641
642 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
643 if (ia6) {
644 if (!ip6_setdstifaddr(m, ia6)) {
645 /*
646 * XXX maybe we should drop the packet here,
647 * as we could not provide enough information
648 * to the upper layers.
649 */
650 }
651 }
652 }
653
654 /*
655 * Process Hop-by-Hop options header if it's contained.
656 * m may be modified in ip6_hopopts_input().
657 * If a JumboPayload option is included, plen will also be modified.
658 */
659 plen = (u_int32_t)ntohs(ip6->ip6_plen);
660 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
661 struct ip6_hbh *hbh;
662
663 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
664#if 0 /*touches NULL pointer*/
665 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
666#endif
667 return; /* m have already been freed */
668 }
669
670 /* adjust pointer */
671 ip6 = mtod(m, struct ip6_hdr *);
672
673 /*
674 * if the payload length field is 0 and the next header field
675 * indicates Hop-by-Hop Options header, then a Jumbo Payload
676 * option MUST be included.
677 */
678 if (ip6->ip6_plen == 0 && plen == 0) {
679 /*
680 * Note that if a valid jumbo payload option is
681 * contained, ip6_hoptops_input() must set a valid
682 * (non-zero) payload length to the variable plen.
683 */
684 ip6stat.ip6s_badoptions++;
685 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
686 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
687 icmp6_error(m, ICMP6_PARAM_PROB,
688 ICMP6_PARAMPROB_HEADER,
689 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
690 return;
691 }
692#ifndef PULLDOWN_TEST
693 /* ip6_hopopts_input() ensures that mbuf is contiguous */
694 hbh = (struct ip6_hbh *)(ip6 + 1);
695#else
696 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
697 sizeof(struct ip6_hbh));
698 if (hbh == NULL) {
699 ip6stat.ip6s_tooshort++;
700 return;
701 }
702#endif
703 nxt = hbh->ip6h_nxt;
704
705 /*
706 * accept the packet if a router alert option is included
707 * and we act as an IPv6 router.
708 */
709 if (rtalert != ~0 && ip6_forwarding)
710 ours = 1;
711 } else
712 nxt = ip6->ip6_nxt;
713
714 /*
715 * Check that the amount of data in the buffers
716 * is as at least much as the IPv6 header would have us expect.
717 * Trim mbufs if longer than we expect.
718 * Drop packet if shorter than we expect.
719 */
720 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
721 ip6stat.ip6s_tooshort++;
722 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
723 goto bad;
724 }
725 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
726 if (m->m_len == m->m_pkthdr.len) {
727 m->m_len = sizeof(struct ip6_hdr) + plen;
728 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
729 } else
730 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
731 }
732
733 /*
734 * Forward if desirable.
735 */
736 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
737 /*
738 * If we are acting as a multicast router, all
739 * incoming multicast packets are passed to the
740 * kernel-level multicast forwarding function.
741 * The packet is returned (relatively) intact; if
742 * ip6_mforward() returns a non-zero value, the packet
743 * must be discarded, else it may be accepted below.
744 */
745 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
746 ip6stat.ip6s_cantforward++;
747 m_freem(m);
748 return;
749 }
750 if (!ours) {
751 m_freem(m);
752 return;
753 }
754 } else if (!ours) {
755 ip6_forward(m, 0);
756 return;
757 }
758
759 ip6 = mtod(m, struct ip6_hdr *);
760
761 /*
762 * Malicious party may be able to use IPv4 mapped addr to confuse
763 * tcp/udp stack and bypass security checks (act as if it was from
764 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
765 *
766 * For SIIT end node behavior, you may want to disable the check.
767 * However, you will become vulnerable to attacks using IPv4 mapped
768 * source.
769 */
770 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
771 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
772 ip6stat.ip6s_badscope++;
773 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
774 goto bad;
775 }
776
777 /*
778 * Tell launch routine the next header
779 */
780 ip6stat.ip6s_delivered++;
781 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
782 nest = 0;
783
784 while (nxt != IPPROTO_DONE) {
785 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
786 ip6stat.ip6s_toomanyhdr++;
787 goto bad;
788 }
789
790 /*
791 * protection against faulty packet - there should be
792 * more sanity checks in header chain processing.
793 */
794 if (m->m_pkthdr.len < off) {
795 ip6stat.ip6s_tooshort++;
796 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
797 goto bad;
798 }
799
800#if 0
801 /*
802 * do we need to do it for every header? yeah, other
803 * functions can play with it (like re-allocate and copy).
804 */
805 mhist = ip6_addaux(m);
806 if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) {
807 hist = mtod(mhist, caddr_t) + mhist->m_len;
808 bcopy(&nxt, hist, sizeof(nxt));
809 mhist->m_len += sizeof(nxt);
810 } else {
811 ip6stat.ip6s_toomanyhdr++;
812 goto bad;
813 }
814#endif
815
816#ifdef IPSEC
817 /*
818 * enforce IPsec policy checking if we are seeing last header.
819 * note that we do not visit this with protocols with pcb layer
820 * code - like udp/tcp/raw ip.
821 */
822 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
823 ipsec6_in_reject(m, NULL)) {
824 ipsec6stat.in_polvio++;
825 goto bad;
826 }
827#endif
828
829 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
830 }
831 return;
832 bad:
833 m_freem(m);
834}
835
836/*
837 * set/grab in6_ifaddr correspond to IPv6 destination address.
838 * XXX backward compatibility wrapper
839 */
840static struct ip6aux *
841ip6_setdstifaddr(m, ia6)
842 struct mbuf *m;
843 struct in6_ifaddr *ia6;
844{
845 struct ip6aux *n;
846
847 n = ip6_addaux(m);
848 if (n)
849 n->ip6a_dstia6 = ia6;
850 return n; /* NULL if failed to set */
851}
852
853struct in6_ifaddr *
854ip6_getdstifaddr(m)
855 struct mbuf *m;
856{
857 struct ip6aux *n;
858
859 n = ip6_findaux(m);
860 if (n)
861 return n->ip6a_dstia6;
862 else
863 return NULL;
864}
865
866/*
867 * Hop-by-Hop options header processing. If a valid jumbo payload option is
868 * included, the real payload length will be stored in plenp.
869 */
870static int
871ip6_hopopts_input(plenp, rtalertp, mp, offp)
872 u_int32_t *plenp;
873 u_int32_t *rtalertp; /* XXX: should be stored more smart way */
874 struct mbuf **mp;
875 int *offp;
876{
877 struct mbuf *m = *mp;
878 int off = *offp, hbhlen;
879 struct ip6_hbh *hbh;
880 u_int8_t *opt;
881
882 /* validation of the length of the header */
883#ifndef PULLDOWN_TEST
884 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
885 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
886 hbhlen = (hbh->ip6h_len + 1) << 3;
887
888 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
889 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
890#else
891 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
892 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
893 if (hbh == NULL) {
894 ip6stat.ip6s_tooshort++;
895 return -1;
896 }
897 hbhlen = (hbh->ip6h_len + 1) << 3;
898 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
899 hbhlen);
900 if (hbh == NULL) {
901 ip6stat.ip6s_tooshort++;
902 return -1;
903 }
904#endif
905 off += hbhlen;
906 hbhlen -= sizeof(struct ip6_hbh);
907 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
908
909 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
910 hbhlen, rtalertp, plenp) < 0)
911 return(-1);
912
913 *offp = off;
914 *mp = m;
915 return(0);
916}
917
918/*
919 * Search header for all Hop-by-hop options and process each option.
920 * This function is separate from ip6_hopopts_input() in order to
921 * handle a case where the sending node itself process its hop-by-hop
922 * options header. In such a case, the function is called from ip6_output().
923 *
924 * The function assumes that hbh header is located right after the IPv6 header
925 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
926 * opthead + hbhlen is located in continuous memory region.
927 */
928int
929ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp)
930 struct mbuf *m;
931 u_int8_t *opthead;
932 int hbhlen;
933 u_int32_t *rtalertp;
934 u_int32_t *plenp;
935{
936 struct ip6_hdr *ip6;
937 int optlen = 0;
938 u_int8_t *opt = opthead;
939 u_int16_t rtalert_val;
940 u_int32_t jumboplen;
941 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
942
943 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
944 switch (*opt) {
945 case IP6OPT_PAD1:
946 optlen = 1;
947 break;
948 case IP6OPT_PADN:
949 if (hbhlen < IP6OPT_MINLEN) {
950 ip6stat.ip6s_toosmall++;
951 goto bad;
952 }
953 optlen = *(opt + 1) + 2;
954 break;
955 case IP6OPT_RTALERT:
956 /* XXX may need check for alignment */
957 if (hbhlen < IP6OPT_RTALERT_LEN) {
958 ip6stat.ip6s_toosmall++;
959 goto bad;
960 }
961 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
962 /* XXX stat */
963 icmp6_error(m, ICMP6_PARAM_PROB,
964 ICMP6_PARAMPROB_HEADER,
965 erroff + opt + 1 - opthead);
966 return(-1);
967 }
968 optlen = IP6OPT_RTALERT_LEN;
969 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
970 *rtalertp = ntohs(rtalert_val);
971 break;
972 case IP6OPT_JUMBO:
973 /* XXX may need check for alignment */
974 if (hbhlen < IP6OPT_JUMBO_LEN) {
975 ip6stat.ip6s_toosmall++;
976 goto bad;
977 }
978 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
979 /* XXX stat */
980 icmp6_error(m, ICMP6_PARAM_PROB,
981 ICMP6_PARAMPROB_HEADER,
982 erroff + opt + 1 - opthead);
983 return(-1);
984 }
985 optlen = IP6OPT_JUMBO_LEN;
986
987 /*
988 * IPv6 packets that have non 0 payload length
989 * must not contain a jumbo payload option.
990 */
991 ip6 = mtod(m, struct ip6_hdr *);
992 if (ip6->ip6_plen) {
993 ip6stat.ip6s_badoptions++;
994 icmp6_error(m, ICMP6_PARAM_PROB,
995 ICMP6_PARAMPROB_HEADER,
996 erroff + opt - opthead);
997 return(-1);
998 }
999
1000 /*
1001 * We may see jumbolen in unaligned location, so
1002 * we'd need to perform bcopy().
1003 */
1004 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1005 jumboplen = (u_int32_t)htonl(jumboplen);
1006
1007#if 1
1008 /*
1009 * if there are multiple jumbo payload options,
1010 * *plenp will be non-zero and the packet will be
1011 * rejected.
1012 * the behavior may need some debate in ipngwg -
1013 * multiple options does not make sense, however,
1014 * there's no explicit mention in specification.
1015 */
1016 if (*plenp != 0) {
1017 ip6stat.ip6s_badoptions++;
1018 icmp6_error(m, ICMP6_PARAM_PROB,
1019 ICMP6_PARAMPROB_HEADER,
1020 erroff + opt + 2 - opthead);
1021 return(-1);
1022 }
1023#endif
1024
1025 /*
1026 * jumbo payload length must be larger than 65535.
1027 */
1028 if (jumboplen <= IPV6_MAXPACKET) {
1029 ip6stat.ip6s_badoptions++;
1030 icmp6_error(m, ICMP6_PARAM_PROB,
1031 ICMP6_PARAMPROB_HEADER,
1032 erroff + opt + 2 - opthead);
1033 return(-1);
1034 }
1035 *plenp = jumboplen;
1036
1037 break;
1038 default: /* unknown option */
1039 if (hbhlen < IP6OPT_MINLEN) {
1040 ip6stat.ip6s_toosmall++;
1041 goto bad;
1042 }
1043 optlen = ip6_unknown_opt(opt, m,
1044 erroff + opt - opthead);
1045 if (optlen == -1)
1046 return(-1);
1047 optlen += 2;
1048 break;
1049 }
1050 }
1051
1052 return(0);
1053
1054 bad:
1055 m_freem(m);
1056 return(-1);
1057}
1058
1059/*
1060 * Unknown option processing.
1061 * The third argument `off' is the offset from the IPv6 header to the option,
1062 * which is necessary if the IPv6 header the and option header and IPv6 header
1063 * is not continuous in order to return an ICMPv6 error.
1064 */
1065int
1066ip6_unknown_opt(optp, m, off)
1067 u_int8_t *optp;
1068 struct mbuf *m;
1069 int off;
1070{
1071 struct ip6_hdr *ip6;
1072
1073 switch (IP6OPT_TYPE(*optp)) {
1074 case IP6OPT_TYPE_SKIP: /* ignore the option */
1075 return((int)*(optp + 1));
1076 case IP6OPT_TYPE_DISCARD: /* silently discard */
1077 m_freem(m);
1078 return(-1);
1079 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1080 ip6stat.ip6s_badoptions++;
1081 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1082 return(-1);
1083 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1084 ip6stat.ip6s_badoptions++;
1085 ip6 = mtod(m, struct ip6_hdr *);
1086 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1087 (m->m_flags & (M_BCAST|M_MCAST)))
1088 m_freem(m);
1089 else
1090 icmp6_error(m, ICMP6_PARAM_PROB,
1091 ICMP6_PARAMPROB_OPTION, off);
1092 return(-1);
1093 }
1094
1095 m_freem(m); /* XXX: NOTREACHED */
1096 return(-1);
1097}
1098
1099/*
1100 * Create the "control" list for this pcb.
1101 * The function will not modify mbuf chain at all.
1102 *
1103 * with KAME mbuf chain restriction:
1104 * The routine will be called from upper layer handlers like tcp6_input().
1105 * Thus the routine assumes that the caller (tcp6_input) have already
1106 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1107 * very first mbuf on the mbuf chain.
1108 */
1109void
1110ip6_savecontrol(in6p, mp, ip6, m)
1111 struct inpcb *in6p;
1112 struct mbuf **mp;
1113 struct ip6_hdr *ip6;
1114 struct mbuf *m;
1115{
1116#if __FreeBSD_version >= 500000
1117 struct thread *td = curthread; /* XXX */
1118#else
1119 struct proc *td = curproc; /* XXX */
1120#endif
1121 int privileged = 0;
1122 int rthdr_exist = 0;
1123
1124
1125 if (td && !suser(td))
1126 privileged++;
1127
1128#ifdef SO_TIMESTAMP
1129 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) {
1130 struct timeval tv;
1131
1132 microtime(&tv);
1133 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1134 SCM_TIMESTAMP, SOL_SOCKET);
1135 if (*mp) {
1136 mp = &(*mp)->m_next;
1137 }
1138 }
1139#endif
1140
1141 /* RFC 2292 sec. 5 */
1142 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
1143 struct in6_pktinfo pi6;
1144 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1145 if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr))
1146 pi6.ipi6_addr.s6_addr16[1] = 0;
1147 pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif)
1148 ? m->m_pkthdr.rcvif->if_index
1149 : 0;
1150 *mp = sbcreatecontrol((caddr_t) &pi6,
1151 sizeof(struct in6_pktinfo), IPV6_PKTINFO,
1152 IPPROTO_IPV6);
1153 if (*mp)
1154 mp = &(*mp)->m_next;
1155 }
1156
1157 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) {
1158 int hlim = ip6->ip6_hlim & 0xff;
1159 *mp = sbcreatecontrol((caddr_t) &hlim,
1160 sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6);
1161 if (*mp)
1162 mp = &(*mp)->m_next;
1163 }
1164
1165 /*
1166 * IPV6_HOPOPTS socket option. We require super-user privilege
1167 * for the option, but it might be too strict, since there might
1168 * be some hop-by-hop options which can be returned to normal user.
1169 * See RFC 2292 section 6.
1170 */
1171 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) {
1172 /*
1173 * Check if a hop-by-hop options header is contatined in the
1174 * received packet, and if so, store the options as ancillary
1175 * data. Note that a hop-by-hop options header must be
1176 * just after the IPv6 header, which fact is assured through
1177 * the IPv6 input processing.
1178 */
1179 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1180 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1181 struct ip6_hbh *hbh;
1182 int hbhlen = 0;
1183#ifdef PULLDOWN_TEST
1184 struct mbuf *ext;
1185#endif
1186
1187#ifndef PULLDOWN_TEST
1188 hbh = (struct ip6_hbh *)(ip6 + 1);
1189 hbhlen = (hbh->ip6h_len + 1) << 3;
1190#else
1191 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1192 ip6->ip6_nxt);
1193 if (ext == NULL) {
1194 ip6stat.ip6s_tooshort++;
1195 return;
1196 }
1197 hbh = mtod(ext, struct ip6_hbh *);
1198 hbhlen = (hbh->ip6h_len + 1) << 3;
1199 if (hbhlen != ext->m_len) {
1200 m_freem(ext);
1201 ip6stat.ip6s_tooshort++;
1202 return;
1203 }
1204#endif
1205
1206 /*
1207 * XXX: We copy whole the header even if a jumbo
1208 * payload option is included, which option is to
1209 * be removed before returning in the RFC 2292.
1210 * Note: this constraint is removed in 2292bis.
1211 */
1212 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1213 IPV6_HOPOPTS, IPPROTO_IPV6);
1214 if (*mp)
1215 mp = &(*mp)->m_next;
1216#ifdef PULLDOWN_TEST
1217 m_freem(ext);
1218#endif
1219 }
1220 }
1221
1222 /* IPV6_DSTOPTS and IPV6_RTHDR socket options */
1223 if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) {
1224 int proto, off, nxt;
1225
1226 /*
1227 * go through the header chain to see if a routing header is
1228 * contained in the packet. We need this information to store
1229 * destination options headers (if any) properly.
1230 * XXX: performance issue. We should record this info when
1231 * processing extension headers in incoming routine.
1232 * (todo) use m_aux?
1233 */
1234 proto = IPPROTO_IPV6;
1235 off = 0;
1236 nxt = -1;
1237 while (1) {
1238 int newoff;
1239
1240 newoff = ip6_nexthdr(m, off, proto, &nxt);
1241 if (newoff < 0)
1242 break;
1243 if (newoff < off) /* invalid, check for safety */
1244 break;
1245 if ((proto = nxt) == IPPROTO_ROUTING) {
1246 rthdr_exist = 1;
1247 break;
1248 }
1249 off = newoff;
1250 }
1251 }
1252
1253 if ((in6p->in6p_flags &
1254 (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) {
1255 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1256 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1257
1258 /*
1259 * Search for destination options headers or routing
1260 * header(s) through the header chain, and stores each
1261 * header as ancillary data.
1262 * Note that the order of the headers remains in
1263 * the chain of ancillary data.
1264 */
1265 while (1) { /* is explicit loop prevention necessary? */
1266 struct ip6_ext *ip6e = NULL;
1267 int elen;
1268#ifdef PULLDOWN_TEST
1269 struct mbuf *ext = NULL;
1270#endif
1271
1272 /*
1273 * if it is not an extension header, don't try to
1274 * pull it from the chain.
1275 */
1276 switch (nxt) {
1277 case IPPROTO_DSTOPTS:
1278 case IPPROTO_ROUTING:
1279 case IPPROTO_HOPOPTS:
1280 case IPPROTO_AH: /* is it possible? */
1281 break;
1282 default:
1283 goto loopend;
1284 }
1285
1286#ifndef PULLDOWN_TEST
1287 if (off + sizeof(*ip6e) > m->m_len)
1288 goto loopend;
1289 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1290 if (nxt == IPPROTO_AH)
1291 elen = (ip6e->ip6e_len + 2) << 2;
1292 else
1293 elen = (ip6e->ip6e_len + 1) << 3;
1294 if (off + elen > m->m_len)
1295 goto loopend;
1296#else
1297 ext = ip6_pullexthdr(m, off, nxt);
1298 if (ext == NULL) {
1299 ip6stat.ip6s_tooshort++;
1300 return;
1301 }
1302 ip6e = mtod(ext, struct ip6_ext *);
1303 if (nxt == IPPROTO_AH)
1304 elen = (ip6e->ip6e_len + 2) << 2;
1305 else
1306 elen = (ip6e->ip6e_len + 1) << 3;
1307 if (elen != ext->m_len) {
1308 m_freem(ext);
1309 ip6stat.ip6s_tooshort++;
1310 return;
1311 }
1312#endif
1313
1314 switch (nxt) {
1315 case IPPROTO_DSTOPTS:
1316 if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0)
1317 break;
1318
1319 /*
1320 * We also require super-user privilege for
1321 * the option.
1322 * See the comments on IN6_HOPOPTS.
1323 */
1324 if (!privileged)
1325 break;
1326
1327 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1328 IPV6_DSTOPTS,
1329 IPPROTO_IPV6);
1330 if (*mp)
1331 mp = &(*mp)->m_next;
1332 break;
1333 case IPPROTO_ROUTING:
1334 if (!in6p->in6p_flags & IN6P_RTHDR)
1335 break;
1336
1337 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1338 IPV6_RTHDR,
1339 IPPROTO_IPV6);
1340 if (*mp)
1341 mp = &(*mp)->m_next;
1342 break;
1343 case IPPROTO_HOPOPTS:
1344 case IPPROTO_AH: /* is it possible? */
1345 break;
1346
1347 default:
1348 /*
1349 * other cases have been filtered in the above.
1350 * none will visit this case. here we supply
1351 * the code just in case (nxt overwritten or
1352 * other cases).
1353 */
1354#ifdef PULLDOWN_TEST
1355 m_freem(ext);
1356#endif
1357 goto loopend;
1358
1359 }
1360
1361 /* proceed with the next header. */
1362 off += elen;
1363 nxt = ip6e->ip6e_nxt;
1364 ip6e = NULL;
1365#ifdef PULLDOWN_TEST
1366 m_freem(ext);
1367 ext = NULL;
1368#endif
1369 }
1370 loopend:
1371 ;
1372 }
1373
1374}
1375
1376#ifdef PULLDOWN_TEST
1377/*
1378 * pull single extension header from mbuf chain. returns single mbuf that
1379 * contains the result, or NULL on error.
1380 */
1381static struct mbuf *
1382ip6_pullexthdr(m, off, nxt)
1383 struct mbuf *m;
1384 size_t off;
1385 int nxt;
1386{
1387 struct ip6_ext ip6e;
1388 size_t elen;
1389 struct mbuf *n;
1390
1391#ifdef DIAGNOSTIC
1392 switch (nxt) {
1393 case IPPROTO_DSTOPTS:
1394 case IPPROTO_ROUTING:
1395 case IPPROTO_HOPOPTS:
1396 case IPPROTO_AH: /* is it possible? */
1397 break;
1398 default:
1399 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1400 }
1401#endif
1402
1403 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1404 if (nxt == IPPROTO_AH)
1405 elen = (ip6e.ip6e_len + 2) << 2;
1406 else
1407 elen = (ip6e.ip6e_len + 1) << 3;
1408
1409 MGET(n, M_DONTWAIT, MT_DATA);
1410 if (n && elen >= MLEN) {
1411 MCLGET(n, M_DONTWAIT);
1412 if ((n->m_flags & M_EXT) == 0) {
1413 m_free(n);
1414 n = NULL;
1415 }
1416 }
1417 if (!n)
1418 return NULL;
1419
1420 n->m_len = 0;
1421 if (elen >= M_TRAILINGSPACE(n)) {
1422 m_free(n);
1423 return NULL;
1424 }
1425
1426 m_copydata(m, off, elen, mtod(n, caddr_t));
1427 n->m_len = elen;
1428 return n;
1429}
1430#endif
1431
1432/*
1433 * Get pointer to the previous header followed by the header
1434 * currently processed.
1435 * XXX: This function supposes that
1436 * M includes all headers,
1437 * the next header field and the header length field of each header
1438 * are valid, and
1439 * the sum of each header length equals to OFF.
1440 * Because of these assumptions, this function must be called very
1441 * carefully. Moreover, it will not be used in the near future when
1442 * we develop `neater' mechanism to process extension headers.
1443 */
1444char *
1445ip6_get_prevhdr(m, off)
1446 struct mbuf *m;
1447 int off;
1448{
1449 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1450
1451 if (off == sizeof(struct ip6_hdr))
1452 return(&ip6->ip6_nxt);
1453 else {
1454 int len, nxt;
1455 struct ip6_ext *ip6e = NULL;
1456
1457 nxt = ip6->ip6_nxt;
1458 len = sizeof(struct ip6_hdr);
1459 while (len < off) {
1460 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1461
1462 switch (nxt) {
1463 case IPPROTO_FRAGMENT:
1464 len += sizeof(struct ip6_frag);
1465 break;
1466 case IPPROTO_AH:
1467 len += (ip6e->ip6e_len + 2) << 2;
1468 break;
1469 default:
1470 len += (ip6e->ip6e_len + 1) << 3;
1471 break;
1472 }
1473 nxt = ip6e->ip6e_nxt;
1474 }
1475 if (ip6e)
1476 return(&ip6e->ip6e_nxt);
1477 else
1478 return NULL;
1479 }
1480}
1481
1482/*
1483 * get next header offset. m will be retained.
1484 */
1485int
1486ip6_nexthdr(m, off, proto, nxtp)
1487 struct mbuf *m;
1488 int off;
1489 int proto;
1490 int *nxtp;
1491{
1492 struct ip6_hdr ip6;
1493 struct ip6_ext ip6e;
1494 struct ip6_frag fh;
1495
1496 /* just in case */
1497 if (m == NULL)
1498 panic("ip6_nexthdr: m == NULL");
1499 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1500 return -1;
1501
1502 switch (proto) {
1503 case IPPROTO_IPV6:
1504 if (m->m_pkthdr.len < off + sizeof(ip6))
1505 return -1;
1506 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1507 if (nxtp)
1508 *nxtp = ip6.ip6_nxt;
1509 off += sizeof(ip6);
1510 return off;
1511
1512 case IPPROTO_FRAGMENT:
1513 /*
1514 * terminate parsing if it is not the first fragment,
1515 * it does not make sense to parse through it.
1516 */
1517 if (m->m_pkthdr.len < off + sizeof(fh))
1518 return -1;
1519 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1520 if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0)
1521 return -1;
1522 if (nxtp)
1523 *nxtp = fh.ip6f_nxt;
1524 off += sizeof(struct ip6_frag);
1525 return off;
1526
1527 case IPPROTO_AH:
1528 if (m->m_pkthdr.len < off + sizeof(ip6e))
1529 return -1;
1530 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1531 if (nxtp)
1532 *nxtp = ip6e.ip6e_nxt;
1533 off += (ip6e.ip6e_len + 2) << 2;
1534 return off;
1535
1536 case IPPROTO_HOPOPTS:
1537 case IPPROTO_ROUTING:
1538 case IPPROTO_DSTOPTS:
1539 if (m->m_pkthdr.len < off + sizeof(ip6e))
1540 return -1;
1541 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1542 if (nxtp)
1543 *nxtp = ip6e.ip6e_nxt;
1544 off += (ip6e.ip6e_len + 1) << 3;
1545 return off;
1546
1547 case IPPROTO_NONE:
1548 case IPPROTO_ESP:
1549 case IPPROTO_IPCOMP:
1550 /* give up */
1551 return -1;
1552
1553 default:
1554 return -1;
1555 }
1556
1557 return -1;
1558}
1559
1560/*
1561 * get offset for the last header in the chain. m will be kept untainted.
1562 */
1563int
1564ip6_lasthdr(m, off, proto, nxtp)
1565 struct mbuf *m;
1566 int off;
1567 int proto;
1568 int *nxtp;
1569{
1570 int newoff;
1571 int nxt;
1572
1573 if (!nxtp) {
1574 nxt = -1;
1575 nxtp = &nxt;
1576 }
1577 while (1) {
1578 newoff = ip6_nexthdr(m, off, proto, nxtp);
1579 if (newoff < 0)
1580 return off;
1581 else if (newoff < off)
1582 return -1; /* invalid */
1583 else if (newoff == off)
1584 return newoff;
1585
1586 off = newoff;
1587 proto = *nxtp;
1588 }
1589}
1590
1591struct ip6aux *
1592ip6_addaux(m)
1593 struct mbuf *m;
1594{
1595 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1596 if (!tag) {
1597 tag = m_tag_get(PACKET_TAG_IPV6_INPUT,
1598 sizeof (struct ip6aux),
1599 M_NOWAIT);
1600 if (tag)
1601 m_tag_prepend(m, tag);
1602 }
1603 if (tag)
1604 bzero(tag+1, sizeof (struct ip6aux));
1605 return tag ? (struct ip6aux*)(tag+1) : NULL;
1606}
1607
1608struct ip6aux *
1609ip6_findaux(m)
1610 struct mbuf *m;
1611{
1612 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1613 return tag ? (struct ip6aux*)(tag+1) : NULL;
1614}
1615
1616void
1617ip6_delaux(m)
1618 struct mbuf *m;
1619{
1620 struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1621 if (tag)
1622 m_tag_delete(m, tag);
1623}
1624
1625/*
1626 * System control for IP6
1627 */
1628
1629u_char inet6ctlerrmap[PRC_NCMDS] = {
1630 0, 0, 0, 0,
1631 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1632 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1633 EMSGSIZE, EHOSTUNREACH, 0, 0,
1634 0, 0, 0, 0,
1635 ENOPROTOOPT
1636};
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