diff options
Diffstat (limited to 'sys/netinet6/icmp6.c')
| -rw-r--r-- | sys/netinet6/icmp6.c | 41 |
1 files changed, 36 insertions, 5 deletions
diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c index aa96326..30e534f 100644 --- a/sys/netinet6/icmp6.c +++ b/sys/netinet6/icmp6.c @@ -245,9 +245,15 @@ icmp6_error(m, type, code, param) oip6 = mtod(m, struct ip6_hdr *); /* - * Multicast destination check. For unrecognized option errors, - * this check has already done in ip6_unknown_opt(), so we can - * check only for other errors. + * If the destination address of the erroneous packet is a multicast + * address, or the packet was sent using link-layer multicast, + * we should basically suppress sending an error (RFC 2463, Section + * 2.4). + * We have two exceptions (the item e.2 in that section): + * - the Pakcet Too Big message can be sent for path MTU discovery. + * - the Parameter Problem Message that can be allowed an icmp6 error + * in the option type field. This check has been done in + * ip6_unknown_opt(), so we can just check the type and code. */ if ((m->m_flags & (M_BCAST|M_MCAST) || IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && @@ -256,7 +262,10 @@ icmp6_error(m, type, code, param) code != ICMP6_PARAMPROB_OPTION))) goto freeit; - /* Source address check. XXX: the case of anycast source? */ + /* + * RFC 2463, 2.4 (e.5): source address check. + * XXX: the case of anycast source? + */ if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) goto freeit; @@ -1100,6 +1109,26 @@ icmp6_mtudisc_update(ip6cp, validated) struct rtentry *rt = NULL; struct sockaddr_in6 sin6; +#if 0 + /* + * RFC2460 section 5, last paragraph. + * even though minimum link MTU for IPv6 is IPV6_MMTU, + * we may see ICMPv6 too big with mtu < IPV6_MMTU + * due to packet translator in the middle. + * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for + * special handling. + */ + if (mtu < IPV6_MMTU) + return; +#endif + + /* + * we reject ICMPv6 too big with abnormally small value. + * XXX what is the good definition of "abnormally small"? + */ + if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) + return; + if (!validated) return; @@ -2122,7 +2151,9 @@ icmp6_reflect(m, off) ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; ip6->ip6_nxt = IPPROTO_ICMPV6; - if (m->m_pkthdr.rcvif) { + if (outif) + ip6->ip6_hlim = ND_IFINFO(outif)->chlim; + else if (m->m_pkthdr.rcvif) { /* XXX: This may not be the outgoing interface */ ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; } else |
