/* * Output a Neighbor Solicitation Message. Caller specifies: * - ICMP6 header source IP6 address * - ND6 header target IP6 address * - ND6 header source datalink address * * Based on RFC 2461 * Based on RFC 2462 (duplicate address detection) * * ln - for source address determination * dad - duplicate address detection */ void nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, const struct in6_addr *taddr6, struct llentry *ln, int dad) { struct mbuf *m; struct m_tag *mtag; struct ip6_hdr *ip6; struct nd_neighbor_solicit *nd_ns; struct ip6_moptions im6o; int icmp6len; int maxlen; caddr_t mac; struct route_in6 ro; if (IN6_IS_ADDR_MULTICAST(taddr6)) return; /* estimate the size of message */ maxlen = sizeof(*ip6) + sizeof(*nd_ns); maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; if (max_linkhdr + maxlen >= MCLBYTES) { #ifdef DIAGNOSTIC printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES " "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); #endif return; } if (max_linkhdr + maxlen > MHLEN) m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); else m = m_gethdr(M_NOWAIT, MT_DATA); if (m == NULL) return; bzero(&ro, sizeof(ro)); if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { m->m_flags |= M_MCAST; im6o.im6o_multicast_ifp = ifp; im6o.im6o_multicast_hlim = 255; im6o.im6o_multicast_loop = 0; } icmp6len = sizeof(*nd_ns); m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ /* fill neighbor solicitation packet */ ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_flow = 0; ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; /* ip6->ip6_plen will be set later */ ip6->ip6_nxt = IPPROTO_ICMPV6; ip6->ip6_hlim = 255; if (daddr6) ip6->ip6_dst = *daddr6; else { ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; ip6->ip6_dst.s6_addr16[1] = 0; ip6->ip6_dst.s6_addr32[1] = 0; ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; ip6->ip6_dst.s6_addr8[12] = 0xff; if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) goto bad; } if (!dad) { struct ifaddr *ifa; /* * RFC2461 7.2.2: * "If the source address of the packet prompting the * solicitation is the same as one of the addresses assigned * to the outgoing interface, that address SHOULD be placed * in the IP Source Address of the outgoing solicitation. * Otherwise, any one of the addresses assigned to the * interface should be used." * * We use the source address for the prompting packet * (saddr6), if: * - saddr6 is given from the caller (by giving "ln"), and * - saddr6 belongs to the outgoing interface. * Otherwise, we perform the source address selection as usual. */ struct in6_addr *hsrc; hsrc = NULL; if (ln != NULL) { LLE_RLOCK(ln); if (ln->la_hold != NULL) { struct ip6_hdr *hip6; /* hold ip6 */ /* * assuming every packet in la_hold has the same IP * header */ hip6 = mtod(ln->la_hold, struct ip6_hdr *); /* XXX pullup? */ if (sizeof(*hip6) < ln->la_hold->m_len) { ip6->ip6_src = hip6->ip6_src; hsrc = &hip6->ip6_src; } } LLE_RUNLOCK(ln); } if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, hsrc)) != NULL) { /* ip6_src set already. */ ifa_free(ifa); } else { int error; struct sockaddr_in6 dst_sa; struct in6_addr src_in; struct ifnet *oifp; bzero(&dst_sa, sizeof(dst_sa)); dst_sa.sin6_family = AF_INET6; dst_sa.sin6_len = sizeof(dst_sa); dst_sa.sin6_addr = ip6->ip6_dst; oifp = ifp; error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &src_in); if (error) { char ip6buf[INET6_ADDRSTRLEN]; nd6log((LOG_DEBUG, "nd6_ns_output: source can't be " "determined: dst=%s, error=%d\n", ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); goto bad; } ip6->ip6_src = src_in; } } else {
/* * Output a Neighbor Solicitation Message. Caller specifies: * - ICMP6 header source IP6 address * - ND6 header target IP6 address * - ND6 header source datalink address * * Based on RFC 2461 * Based on RFC 2462 (duplicate address detection) * * ln - for source address determination * nonce - If non-NULL, NS is used for duplicate address detection and * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. */ static void nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, const struct in6_addr *daddr6, const struct in6_addr *taddr6, uint8_t *nonce, u_int fibnum) { struct mbuf *m; struct m_tag *mtag; struct ip6_hdr *ip6; struct nd_neighbor_solicit *nd_ns; struct ip6_moptions im6o; int icmp6len; int maxlen; caddr_t mac; if (IN6_IS_ADDR_MULTICAST(taddr6)) return; /* estimate the size of message */ maxlen = sizeof(*ip6) + sizeof(*nd_ns); maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", __func__, max_linkhdr, maxlen, MCLBYTES)); if (max_linkhdr + maxlen > MHLEN) m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); else m = m_gethdr(M_NOWAIT, MT_DATA); if (m == NULL) return; M_SETFIB(m, fibnum); if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { m->m_flags |= M_MCAST; im6o.im6o_multicast_ifp = ifp; im6o.im6o_multicast_hlim = 255; im6o.im6o_multicast_loop = 0; } icmp6len = sizeof(*nd_ns); m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ /* fill neighbor solicitation packet */ ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_flow = 0; ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; /* ip6->ip6_plen will be set later */ ip6->ip6_nxt = IPPROTO_ICMPV6; ip6->ip6_hlim = 255; if (daddr6) ip6->ip6_dst = *daddr6; else { ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; ip6->ip6_dst.s6_addr16[1] = 0; ip6->ip6_dst.s6_addr32[1] = 0; ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; ip6->ip6_dst.s6_addr8[12] = 0xff; if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) goto bad; } if (nonce == NULL) { struct ifaddr *ifa = NULL; /* * RFC2461 7.2.2: * "If the source address of the packet prompting the * solicitation is the same as one of the addresses assigned * to the outgoing interface, that address SHOULD be placed * in the IP Source Address of the outgoing solicitation. * Otherwise, any one of the addresses assigned to the * interface should be used." * * We use the source address for the prompting packet * (saddr6), if saddr6 belongs to the outgoing interface. * Otherwise, we perform the source address selection as usual. */ if (saddr6 != NULL) ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); if (ifa != NULL) { /* ip6_src set already. */ ip6->ip6_src = *saddr6; ifa_free(ifa); } else { int error; struct in6_addr dst6, src6; uint32_t scopeid; in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6, scopeid, ifp, &src6, NULL); if (error) { char ip6buf[INET6_ADDRSTRLEN]; nd6log((LOG_DEBUG, "%s: source can't be " "determined: dst=%s, error=%d\n", __func__, ip6_sprintf(ip6buf, &dst6), error)); goto bad; } ip6->ip6_src = src6; } } else { /* * Source address for DAD packet must always be IPv6 * unspecified address. (0::0) * We actually don't have to 0-clear the address (we did it * above), but we do so here explicitly to make the intention * clearer. */ bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); } nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; nd_ns->nd_ns_code = 0; nd_ns->nd_ns_reserved = 0; nd_ns->nd_ns_target = *taddr6; in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ /* * Add source link-layer address option. * * spec implementation * --- --- * DAD packet MUST NOT do not add the option * there's no link layer address: * impossible do not add the option * there's link layer address: * Multicast NS MUST add one add the option * Unicast NS SHOULD add one add the option */ if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); /* 8 byte alignments... */ optlen = (optlen + 7) & ~7; m->m_pkthdr.len += optlen; m->m_len += optlen; icmp6len += optlen; bzero((caddr_t)nd_opt, optlen); nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; nd_opt->nd_opt_len = optlen >> 3; bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); }
/* * Input a Neighbor Solicitation Message. * * Based on RFC 2461 * Based on RFC 2462 (duplicate address detection) */ void nd6_ns_input(struct mbuf *m, int off, int icmp6len) { struct ifnet *ifp = m->m_pkthdr.rcvif; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_neighbor_solicit *nd_ns; struct in6_addr saddr6 = ip6->ip6_src; struct in6_addr daddr6 = ip6->ip6_dst; struct in6_addr taddr6; struct in6_addr myaddr6; char *lladdr = NULL; struct ifaddr *ifa = NULL; int lladdrlen = 0; int anycast = 0, proxy = 0, tentative = 0; int tlladdr; int rflag; union nd_opts ndopts; struct sockaddr_dl proxydl; char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) rflag = 0; #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, icmp6len,); nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); #else IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); if (nd_ns == NULL) { ICMP6STAT_INC(icp6s_tooshort); return; } #endif ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ taddr6 = nd_ns->nd_ns_target; if (in6_setscope(&taddr6, ifp, NULL) != 0) goto bad; if (ip6->ip6_hlim != 255) { nd6log((LOG_ERR, "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); goto bad; } if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { /* dst has to be a solicited node multicast address. */ if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && /* don't check ifindex portion */ daddr6.s6_addr32[1] == 0 && daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && daddr6.s6_addr8[12] == 0xff) { ; /* good */ } else { nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " "(wrong ip6 dst)\n")); goto bad; } } else if (!V_nd6_onlink_ns_rfc4861) { struct sockaddr_in6 src_sa6; /* * According to recent IETF discussions, it is not a good idea * to accept a NS from an address which would not be deemed * to be a neighbor otherwise. This point is expected to be * clarified in future revisions of the specification. */ bzero(&src_sa6, sizeof(src_sa6)); src_sa6.sin6_family = AF_INET6; src_sa6.sin6_len = sizeof(src_sa6); src_sa6.sin6_addr = saddr6; if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { nd6log((LOG_INFO, "nd6_ns_input: " "NS packet from non-neighbor\n")); goto bad; } } if (IN6_IS_ADDR_MULTICAST(&taddr6)) { nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); goto bad; } icmp6len -= sizeof(*nd_ns); nd6_option_init(nd_ns + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log((LOG_INFO, "nd6_ns_input: invalid ND option, ignored\n")); /* nd6_options have incremented stats */ goto freeit; } if (ndopts.nd_opts_src_lladdr) { lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; } if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " "(link-layer address option)\n")); goto bad; } /* * Attaching target link-layer address to the NA? * (RFC 2461 7.2.4) * * NS IP dst is unicast/anycast MUST NOT add * NS IP dst is solicited-node multicast MUST add * * In implementation, we add target link-layer address by default. * We do not add one in MUST NOT cases. */ if (!IN6_IS_ADDR_MULTICAST(&daddr6)) tlladdr = 0; else tlladdr = 1; /* * Target address (taddr6) must be either: * (1) Valid unicast/anycast address for my receiving interface, * (2) Unicast address for which I'm offering proxy service, or * (3) "tentative" address on which DAD is being performed. */ /* (1) and (3) check. */ if (ifp->if_carp) ifa = (*carp_iamatch6_p)(ifp, &taddr6); else ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); /* (2) check. */ if (ifa == NULL) { struct route_in6 ro; int need_proxy; bzero(&ro, sizeof(ro)); ro.ro_dst.sin6_len = sizeof(struct sockaddr_in6); ro.ro_dst.sin6_family = AF_INET6; ro.ro_dst.sin6_addr = taddr6; /* Always use the default FIB. */ #ifdef RADIX_MPATH rtalloc_mpath_fib((struct route *)&ro, RTF_ANNOUNCE, RT_DEFAULT_FIB); #else in6_rtalloc(&ro, RT_DEFAULT_FIB); #endif need_proxy = (ro.ro_rt && (ro.ro_rt->rt_flags & RTF_ANNOUNCE) != 0 && ro.ro_rt->rt_gateway->sa_family == AF_LINK); if (ro.ro_rt != NULL) { if (need_proxy) proxydl = *SDL(ro.ro_rt->rt_gateway); RTFREE(ro.ro_rt); } if (need_proxy) { /* * proxy NDP for single entry */ ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); if (ifa) proxy = 1; } } if (ifa == NULL) { /* * We've got an NS packet, and we don't have that adddress * assigned for us. We MUST silently ignore it. * See RFC2461 7.2.3. */ goto freeit; } myaddr6 = *IFA_IN6(ifa); anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) goto freeit; if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " "(if %d, NS packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), ifp->if_addrlen, lladdrlen - 2)); goto bad; } if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", ip6_sprintf(ip6bufs, &saddr6))); goto freeit; } /* * We have neighbor solicitation packet, with target address equals to * one of my tentative address. * * src addr how to process? * --- --- * multicast of course, invalid (rejected in ip6_input) * unicast somebody is doing address resolution -> ignore * unspec dup address detection * * The processing is defined in RFC 2462. */ if (tentative) { /* * If source address is unspecified address, it is for * duplicate address detection. * * If not, the packet is for addess resolution; * silently ignore it. */ if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) nd6_dad_ns_input(ifa); goto freeit; } /* * If the source address is unspecified address, entries must not * be created or updated. * It looks that sender is performing DAD. Output NA toward * all-node multicast address, to tell the sender that I'm using * the address. * S bit ("solicited") must be zero. */ if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { struct in6_addr in6_all; in6_all = in6addr_linklocal_allnodes; if (in6_setscope(&in6_all, ifp, NULL) != 0) goto bad; nd6_na_output_fib(ifp, &in6_all, &taddr6, ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); goto freeit; } nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0); nd6_na_output_fib(ifp, &saddr6, &taddr6, ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | rflag | ND_NA_FLAG_SOLICITED, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); freeit: if (ifa != NULL) ifa_free(ifa); m_freem(m); return; bad: nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(ip6bufs, &saddr6))); nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(ip6bufs, &daddr6))); nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(ip6bufs, &taddr6))); ICMP6STAT_INC(icp6s_badns); if (ifa != NULL) ifa_free(ifa); m_freem(m); }
/* * NOTE: in6_ifdetach() does not support loopback if at this moment. * We don't need this function in bsdi, because interfaces are never removed * from the ifnet list in bsdi. */ void in6_ifdetach(struct ifnet *ifp) { struct in6_ifaddr *ia, *oia; struct ifaddr *ifa, *next; struct rtentry *rt; short rtflags; struct in6_multi_mship *imm; /* remove ip6_mrouter stuff */ ip6_mrouter_detach(ifp); /* remove neighbor management table */ nd6_purge(ifp); /* XXX this code is duplicated in in6_purgeif() --dyoung */ /* nuke any of IPv6 addresses we have */ if_purgeaddrs(ifp, AF_INET6, in6_purgeaddr); /* XXX isn't this code is redundant, given the above? --dyoung */ /* XXX doesn't this code replicate code in in6_purgeaddr() ? --dyoung */ /* undo everything done by in6_ifattach(), just in case */ for (ifa = IFADDR_FIRST(ifp); ifa != NULL; ifa = next) { next = IFADDR_NEXT(ifa); if (ifa->ifa_addr->sa_family != AF_INET6 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) { continue; } ia = (struct in6_ifaddr *)ifa; /* * leave from multicast groups we have joined for the interface */ while ((imm = LIST_FIRST(&ia->ia6_memberships)) != NULL) { LIST_REMOVE(imm, i6mm_chain); in6_leavegroup(imm); } /* remove from the routing table */ if ((ia->ia_flags & IFA_ROUTE) && (rt = rtalloc1((struct sockaddr *)&ia->ia_addr, 0))) { rtflags = rt->rt_flags; rtfree(rt); rtrequest(RTM_DELETE, (struct sockaddr *)&ia->ia_addr, (struct sockaddr *)&ia->ia_addr, (struct sockaddr *)&ia->ia_prefixmask, rtflags, NULL); } /* remove from the linked list */ ifa_remove(ifp, &ia->ia_ifa); /* also remove from the IPv6 address chain(itojun&jinmei) */ oia = ia; if (oia == (ia = in6_ifaddr)) in6_ifaddr = ia->ia_next; else { while (ia->ia_next && (ia->ia_next != oia)) ia = ia->ia_next; if (ia->ia_next) ia->ia_next = oia->ia_next; else { nd6log((LOG_ERR, "%s: didn't unlink in6ifaddr from list\n", if_name(ifp))); } } ifafree(&oia->ia_ifa); } /* cleanup multicast address kludge table, if there is any */ in6_purgemkludge(ifp); /* * remove neighbor management table. we call it twice just to make * sure we nuke everything. maybe we need just one call. * XXX: since the first call did not release addresses, some prefixes * might remain. We should call nd6_purge() again to release the * prefixes after removing all addresses above. * (Or can we just delay calling nd6_purge until at this point?) */ nd6_purge(ifp); }
/* * Input an Neighbor Solicitation Message. * * Based on RFC 2461 * Based on RFC 2462 (duplicated address detection) */ void nd6_ns_input(struct mbuf *m, int off, int icmp6len) { struct ifnet *ifp = m->m_pkthdr.rcvif; struct ifnet *cmpifp; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_neighbor_solicit *nd_ns; struct in6_addr saddr6 = ip6->ip6_src; struct in6_addr daddr6 = ip6->ip6_dst; struct in6_addr taddr6; struct in6_addr myaddr6; char *lladdr = NULL; struct ifaddr *ifa = NULL; int lladdrlen = 0; int anycast = 0, proxy = 0, tentative = 0; int tlladdr; union nd_opts ndopts; struct sockaddr_dl *proxydl = NULL; /* * Collapse interfaces to the bridge for comparison and * mac (llinfo) purposes. */ cmpifp = ifp; if (ifp->if_bridge) cmpifp = ifp->if_bridge; #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, icmp6len,); nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); #else IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); if (nd_ns == NULL) { icmp6stat.icp6s_tooshort++; return; } #endif ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ taddr6 = nd_ns->nd_ns_target; if (ip6->ip6_hlim != 255) { nd6log((LOG_ERR, "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst), if_name(ifp))); goto bad; } if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { /* dst has to be solicited node multicast address. */ if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && /* don't check ifindex portion */ daddr6.s6_addr32[1] == 0 && daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && daddr6.s6_addr8[12] == 0xff) { ; /* good */ } else { nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " "(wrong ip6 dst)\n")); goto bad; } } else if (!nd6_onlink_ns_rfc4861) { /* * Make sure the source address is from a neighbor's address. * * XXX probably only need to check cmpifp. */ if (in6ifa_ifplocaladdr(cmpifp, &saddr6) == NULL && in6ifa_ifplocaladdr(ifp, &saddr6) == NULL) { nd6log((LOG_INFO, "nd6_ns_input: " "NS packet from non-neighbor\n")); goto bad; } } if (IN6_IS_ADDR_MULTICAST(&taddr6)) { nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); goto bad; } if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) taddr6.s6_addr16[1] = htons(ifp->if_index); icmp6len -= sizeof(*nd_ns); nd6_option_init(nd_ns + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log((LOG_INFO, "nd6_ns_input: invalid ND option, ignored\n")); /* nd6_options have incremented stats */ goto freeit; } if (ndopts.nd_opts_src_lladdr) { lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; } if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " "(link-layer address option)\n")); goto bad; } /* * Attaching target link-layer address to the NA? * (RFC 2461 7.2.4) * * NS IP dst is unicast/anycast MUST NOT add * NS IP dst is solicited-node multicast MUST add * * In implementation, we add target link-layer address by default. * We do not add one in MUST NOT cases. */ #if 0 /* too much! */ ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6); if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)) tlladdr = 0; else #endif if (!IN6_IS_ADDR_MULTICAST(&daddr6)) tlladdr = 0; else tlladdr = 1; /* * Target address (taddr6) must be either: * (1) Valid unicast/anycast address for my receiving interface. * (2) Unicast or anycast address for which I'm offering proxy * service. * (3) "tentative" address on which DAD is being performed. */ /* (1) and (3) check. */ #ifdef CARP if (ifp->if_carp) ifa = carp_iamatch6(ifp->if_carp, &taddr6); if (!ifa) ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); #else ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); #endif /* * (2) Check proxying. Requires ip6_forwarding to be turned on. * * If the packet is anycast the target route must be on a * different interface because the anycast will get anything * on the current interface. * * If the packet is unicast the target route may be on the * same interface. If the gateway is a (typically manually * configured) link address we can directly offer it. * XXX for now we don't do this but instead offer ours and * presumably relay. * * WARNING! Since this is a subnet proxy the interface proxying * the ND6 must be in promiscuous mode or it will not see the * solicited multicast requests for various hosts being proxied. * * WARNING! Since this is a subnet proxy we have to treat bridge * interfaces as being the bridge itself so we do not proxy-nd6 * between bridge interfaces (which are effectively switched). * * (In the specific-host-proxy case via RTF_ANNOUNCE, which is * a bitch to configure, a specific multicast route is already * added for that host <-- NOT RECOMMENDED). */ if (!ifa && ip6_forwarding) { struct rtentry *rt; struct sockaddr_in6 tsin6; struct ifnet *rtifp; bzero(&tsin6, sizeof tsin6); tsin6.sin6_len = sizeof(struct sockaddr_in6); tsin6.sin6_family = AF_INET6; tsin6.sin6_addr = taddr6; rt = rtpurelookup((struct sockaddr *)&tsin6); rtifp = rt ? rt->rt_ifp : NULL; if (rtifp && rtifp->if_bridge) rtifp = rtifp->if_bridge; if (rt != NULL && (cmpifp != rtifp || (cmpifp == rtifp && (m->m_flags & M_MCAST) == 0)) ) { ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(cmpifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); nd6log((LOG_INFO, "nd6_ns_input: nd6 proxy %s(%s)<-%s ifa %p\n", if_name(cmpifp), if_name(ifp), if_name(rtifp), ifa)); if (ifa) { proxy = 1; /* * Manual link address on same interface * w/announce flag will proxy-arp using * target mac, else our mac is used. */ if (cmpifp == rtifp && (rt->rt_flags & RTF_ANNOUNCE) && rt->rt_gateway->sa_family == AF_LINK) { proxydl = SDL(rt->rt_gateway); } } } if (rt != NULL) --rt->rt_refcnt; } if (ifa == NULL) { /* * We've got an NS packet, and we don't have that adddress * assigned for us. We MUST silently ignore it. * See RFC2461 7.2.3. */ goto freeit; } myaddr6 = *IFA_IN6(ifa); anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) goto freeit; if (lladdr && ((cmpifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " "(if %d, NS packet %d)\n", ip6_sprintf(&taddr6), cmpifp->if_addrlen, lladdrlen - 2)); goto bad; } if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", ip6_sprintf(&saddr6))); goto freeit; } /* * We have neighbor solicitation packet, with target address equals to * one of my tentative address. * * src addr how to process? * --- --- * multicast of course, invalid (rejected in ip6_input) * unicast somebody is doing address resolution -> ignore * unspec dup address detection * * The processing is defined in RFC 2462. */ if (tentative) { /* * If source address is unspecified address, it is for * duplicated address detection. * * If not, the packet is for addess resolution; * silently ignore it. */ if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) nd6_dad_ns_input(ifa); goto freeit; } /* * If the source address is unspecified address, entries must not * be created or updated. * It looks that sender is performing DAD. Output NA toward * all-node multicast address, to tell the sender that I'm using * the address. * S bit ("solicited") must be zero. */ if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { saddr6 = kin6addr_linklocal_allnodes; saddr6.s6_addr16[1] = htons(cmpifp->if_index); nd6_na_output(cmpifp, &saddr6, &taddr6, ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0), tlladdr, (struct sockaddr *)proxydl); goto freeit; } nd6_cache_lladdr(cmpifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0); nd6_na_output(ifp, &saddr6, &taddr6, ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED, tlladdr, (struct sockaddr *)proxydl); freeit: m_freem(m); return; bad: nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6))); nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6))); nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6))); icmp6stat.icp6s_badns++; m_freem(m); }
/* * XXX multiple loopback interface needs more care. for instance, * nodelocal address needs to be configured onto only one of them. * XXX multiple link-local address case * * altifp - secondary EUI64 source */ void in6_ifattach(struct ifnet *ifp, struct ifnet *altifp) { struct in6_ifaddr *ia; struct in6_addr in6; /* some of the interfaces are inherently not IPv6 capable */ switch (ifp->if_type) { case IFT_BRIDGE: #ifdef IFT_PFLOG case IFT_PFLOG: #endif #ifdef IFT_PFSYNC case IFT_PFSYNC: #endif ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL; ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; return; } /* * if link mtu is too small, don't try to configure IPv6. * remember there could be some link-layer that has special * fragmentation logic. */ if (ifp->if_mtu < IPV6_MMTU) { nd6log((LOG_INFO, "in6_ifattach: " "%s has too small MTU, IPv6 not enabled\n", if_name(ifp))); return; } /* create a multicast kludge storage (if we have not had one) */ in6_createmkludge(ifp); /* * quirks based on interface type */ switch (ifp->if_type) { #ifdef IFT_STF case IFT_STF: /* * 6to4 interface is a very special kind of beast. * no multicast, no linklocal. RFC2529 specifies how to make * linklocals for 6to4 interface, but there's no use and * it is rather harmful to have one. */ ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL; return; #endif case IFT_CARP: return; default: break; } /* * usually, we require multicast capability to the interface */ if ((ifp->if_flags & IFF_MULTICAST) == 0) { nd6log((LOG_INFO, "in6_ifattach: " "%s is not multicast capable, IPv6 not enabled\n", if_name(ifp))); return; } /* * assign loopback address for loopback interface. * XXX multiple loopback interface case. */ if ((ifp->if_flags & IFF_LOOPBACK) != 0) { in6 = in6addr_loopback; if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) { if (in6_ifattach_loopback(ifp) != 0) return; } } /* * assign a link-local address, if there's none. */ if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) && ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) { ia = in6ifa_ifpforlinklocal(ifp, 0); if (ia == NULL && in6_ifattach_linklocal(ifp, altifp) != 0) { printf("%s: cannot assign link-local address\n", ifp->if_xname); } } }
static int in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp) { struct in6_ifaddr *ia __diagused; struct in6_aliasreq ifra; struct nd_prefixctl prc0; int i, error; /* * configure link-local address. */ memset(&ifra, 0, sizeof(ifra)); /* * in6_update_ifa() does not use ifra_name, but we accurately set it * for safety. */ strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name)); ifra.ifra_addr.sin6_family = AF_INET6; ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000); ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; if ((ifp->if_flags & IFF_LOOPBACK) != 0) { ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0; ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1); } else { if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) { nd6log((LOG_ERR, "%s: no ifid available\n", if_name(ifp))); return -1; } } if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL)) return -1; sockaddr_in6_init(&ifra.ifra_prefixmask, &in6mask64, 0, 0, 0); /* link-local addresses should NEVER expire. */ ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; /* * Now call in6_update_ifa() to do a bunch of procedures to configure * a link-local address. We can set the 3rd argument to NULL, because * we know there's no other link-local address on the interface * and therefore we are adding one (instead of updating one). */ if ((error = in6_update_ifa(ifp, &ifra, NULL, IN6_IFAUPDATE_DADDELAY)) != 0) { /* * XXX: When the interface does not support IPv6, this call * would fail in the SIOCINITIFADDR ioctl. I believe the * notification is rather confusing in this case, so just * suppress it. ([email protected] 20010130) */ if (error != EAFNOSUPPORT) nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to " "configure a link-local address on %s " "(errno=%d)\n", if_name(ifp), error)); return -1; } ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */ KASSERTMSG(ia, "ia == NULL in in6_ifattach_linklocal"); /* * Make the link-local prefix (fe80::/64%link) as on-link. * Since we'd like to manage prefixes separately from addresses, * we make an ND6 prefix structure for the link-local prefix, * and add it to the prefix list as a never-expire prefix. * XXX: this change might affect some existing code base... */ memset(&prc0, 0, sizeof(prc0)); prc0.ndprc_ifp = ifp; /* this should be 64 at this moment. */ prc0.ndprc_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL); prc0.ndprc_prefix = ifra.ifra_addr; /* apply the mask for safety. (nd6_prelist_add will apply it again) */ for (i = 0; i < 4; i++) { prc0.ndprc_prefix.sin6_addr.s6_addr32[i] &= in6mask64.s6_addr32[i]; } /* * Initialize parameters. The link-local prefix must always be * on-link, and its lifetimes never expire. */ prc0.ndprc_raf_onlink = 1; prc0.ndprc_raf_auto = 1; /* probably meaningless */ prc0.ndprc_vltime = ND6_INFINITE_LIFETIME; prc0.ndprc_pltime = ND6_INFINITE_LIFETIME; /* * Since there is no other link-local addresses, nd6_prefix_lookup() * probably returns NULL. However, we cannot always expect the result. * For example, if we first remove the (only) existing link-local * address, and then reconfigure another one, the prefix is still * valid with referring to the old link-local address. */ if (nd6_prefix_lookup(&prc0) == NULL) { if ((error = nd6_prelist_add(&prc0, NULL, NULL)) != 0) return error; } return 0; }
/* * Get interface identifier for the specified interface. If it is not * available on ifp0, borrow interface identifier from other information * sources. * * altifp - secondary EUI64 source */ static int get_ifid(struct ifnet *ifp0, struct ifnet *altifp, struct in6_addr *in6) { struct ifnet *ifp; /* first, try to get it from the interface itself */ if (in6_get_hw_ifid(ifp0, in6) == 0) { nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n", if_name(ifp0))); goto success; } /* try secondary EUI64 source. this basically is for ATM PVC */ if (altifp && in6_get_hw_ifid(altifp, in6) == 0) { nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n", if_name(ifp0), if_name(altifp))); goto success; } /* next, try to get it from some other hardware interface */ IFNET_FOREACH(ifp) { if (ifp == ifp0) continue; if (in6_get_hw_ifid(ifp, in6) != 0) continue; /* * to borrow ifid from other interface, ifid needs to be * globally unique */ if (IFID_UNIVERSAL(in6)) { nd6log((LOG_DEBUG, "%s: borrow interface identifier from %s\n", if_name(ifp0), if_name(ifp))); goto success; } } #if 0 /* get from hostid - only for certain architectures */ if (get_hostid_ifid(ifp, in6) == 0) { nd6log((LOG_DEBUG, "%s: interface identifier generated by hostid\n", if_name(ifp0))); goto success; } #endif /* last resort: get from random number source */ if (get_rand_ifid(ifp, in6) == 0) { nd6log((LOG_DEBUG, "%s: interface identifier generated by random number\n", if_name(ifp0))); goto success; } printf("%s: failed to get interface identifier\n", if_name(ifp0)); return -1; success: nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n", if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10], in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13], in6->s6_addr[14], in6->s6_addr[15])); return 0; }
static int generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret) { MD5_CTX ctxt; u_int8_t seed[16], digest[16], nullbuf[8]; /* * interface ID for subnet anycast addresses. * XXX: we assume the unicast address range that requires IDs * in EUI-64 format. */ static const uint8_t anycast_id[8] = { 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x80 }; static const uint8_t isatap_id[4] = { 0x00, 0x00, 0x5e, 0xfe }; int badid, retry = 0; /* If there's no hisotry, start with a random seed. */ memset(nullbuf, 0, sizeof(nullbuf)); if (memcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) { cprng_fast(seed, sizeof(seed)); } else memcpy(seed, seed0, 8); /* copy the right-most 64-bits of the given address */ /* XXX assumption on the size of IFID */ memcpy(&seed[8], seed1, 8); again: /* for debugging purposes only */ #if 0 { int i; printf("generate_tmp_ifid: new randomized ID from: "); for (i = 0; i < 16; i++) printf("%02x", seed[i]); printf(" "); } #endif /* generate 16 bytes of pseudo-random value. */ memset(&ctxt, 0, sizeof(ctxt)); MD5Init(&ctxt); MD5Update(&ctxt, seed, sizeof(seed)); MD5Final(digest, &ctxt); /* * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (3) * Take the left-most 64-bits of the MD5 digest and set bit 6 (the * left-most bit is numbered 0) to zero. */ memcpy(ret, digest, 8); ret[0] &= ~EUI64_UBIT; /* * Reject inappropriate identifiers according to * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (4) * At this moment, we reject following cases: * - all 0 identifier * - identifiers that conflict with reserved subnet anycast addresses, * which are defined in RFC 2526. * - identifiers that conflict with ISATAP addresses * - identifiers used in our own addresses */ badid = 0; if (memcmp(nullbuf, ret, sizeof(nullbuf)) == 0) badid = 1; else if (memcmp(anycast_id, ret, 7) == 0 && (anycast_id[7] & ret[7]) == anycast_id[7]) { badid = 1; } else if (memcmp(isatap_id, ret, sizeof(isatap_id)) == 0) badid = 1; else { struct in6_ifaddr *ia; for (ia = in6_ifaddr; ia; ia = ia->ia_next) { if (!memcmp(&ia->ia_addr.sin6_addr.s6_addr[8], ret, 8)) { badid = 1; break; } } } /* * In the event that an unacceptable identifier has been generated, * restart the process, using the right-most 64 bits of the MD5 digest * obtained in place of the history value. */ if (badid) { /* for debugging purposes only */ #if 0 { int i; printf("unacceptable random ID: "); for (i = 0; i < 16; i++) printf("%02x", digest[i]); printf("\n"); } #endif if (++retry < GEN_TEMPID_RETRY_MAX) { memcpy(seed, &digest[8], 8); goto again; } else { /* * We're so unlucky. Give up for now, and return * all 0 IDs to tell the caller not to make a * temporary address. */ nd6log((LOG_NOTICE, "generate_tmp_ifid: never found a good ID\n")); memset(ret, 0, 8); } } /* * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (6) * Take the rightmost 64-bits of the MD5 digest and save them in * stable storage as the history value to be used in the next * iteration of the algorithm. */ memcpy(seed0, &digest[8], 8); /* for debugging purposes only */ #if 0 { int i; printf("to: "); for (i = 0; i < 16; i++) printf("%02x", digest[i]); printf("\n"); } #endif return 0; }
/* * Input an Neighbor Solicitation Message. * * Based on RFC 2461 * Based on RFC 2462 (duplicated address detection) */ void nd6_ns_input(struct mbuf *m, int off, int icmp6len) { struct ifnet *ifp = m->m_pkthdr.rcvif; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_neighbor_solicit *nd_ns; struct in6_addr saddr6 = ip6->ip6_src; struct in6_addr daddr6 = ip6->ip6_dst; struct in6_addr taddr6; struct in6_addr myaddr6; char *lladdr = NULL; struct ifaddr *ifa = NULL; int lladdrlen = 0; int anycast = 0, proxy = 0, tentative = 0; int router = ip6_forwarding; int tlladdr; union nd_opts ndopts; struct sockaddr_dl *proxydl = NULL; char addr[INET6_ADDRSTRLEN], addr0[INET6_ADDRSTRLEN]; IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); if (nd_ns == NULL) { icmp6stat.icp6s_tooshort++; return; } ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ taddr6 = nd_ns->nd_ns_target; if (ip6->ip6_hlim != 255) { nd6log((LOG_ERR, "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, inet_ntop(AF_INET6, &ip6->ip6_src, addr, sizeof(addr)), inet_ntop(AF_INET6, &ip6->ip6_dst, addr0, sizeof(addr0)), ifp->if_xname)); goto bad; } if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { /* dst has to be solicited node multicast address. */ /* don't check ifindex portion */ if (daddr6.s6_addr16[0] == __IPV6_ADDR_INT16_MLL && daddr6.s6_addr32[1] == 0 && daddr6.s6_addr32[2] == __IPV6_ADDR_INT32_ONE && daddr6.s6_addr8[12] == 0xff) { ; /*good*/ } else { nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " "(wrong ip6 dst)\n")); goto bad; } } else { /* * Make sure the source address is from a neighbor's address. */ if (!in6_ifpprefix(ifp, &saddr6)) { nd6log((LOG_INFO, "nd6_ns_input: " "NS packet from non-neighbor\n")); goto bad; } } if (IN6_IS_ADDR_MULTICAST(&taddr6)) { nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); goto bad; } if (IN6_IS_SCOPE_EMBED(&taddr6)) taddr6.s6_addr16[1] = htons(ifp->if_index); icmp6len -= sizeof(*nd_ns); nd6_option_init(nd_ns + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log((LOG_INFO, "nd6_ns_input: invalid ND option, ignored\n")); /* nd6_options have incremented stats */ goto freeit; } if (ndopts.nd_opts_src_lladdr) { lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; } if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " "(link-layer address option)\n")); goto bad; } /* * Attaching target link-layer address to the NA? * (RFC 2461 7.2.4) * * NS IP dst is unicast/anycast MUST NOT add * NS IP dst is solicited-node multicast MUST add * * In implementation, we add target link-layer address by default. * We do not add one in MUST NOT cases. */ #if 0 /* too much! */ ifa = &in6ifa_ifpwithaddr(ifp, &daddr6)->ia_ifa; if (ifa && (ifatoia6(ifa)->ia6_flags & IN6_IFF_ANYCAST)) tlladdr = 0; else #endif if (!IN6_IS_ADDR_MULTICAST(&daddr6)) tlladdr = 0; else tlladdr = 1; /* * Target address (taddr6) must be either: * (1) Valid unicast/anycast address for my receiving interface, * (2) Unicast address for which I'm offering proxy service, or * (3) "tentative" address on which DAD is being performed. */ /* (1) and (3) check. */ ifa = &in6ifa_ifpwithaddr(ifp, &taddr6)->ia_ifa; #if NCARP > 0 if (ifp->if_type == IFT_CARP && ifa && !carp_iamatch6(ifp, lladdr, &proxydl)) ifa = NULL; #endif /* (2) check. */ if (!ifa) { struct rtentry *rt; struct sockaddr_in6 tsin6; bzero(&tsin6, sizeof tsin6); tsin6.sin6_len = sizeof(struct sockaddr_in6); tsin6.sin6_family = AF_INET6; tsin6.sin6_addr = taddr6; rt = rtalloc1(sin6tosa(&tsin6), 0, m->m_pkthdr.rdomain); if (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 && rt->rt_gateway->sa_family == AF_LINK) { /* * proxy NDP for single entry */ ifa = &in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY | IN6_IFF_ANYCAST)->ia_ifa; if (ifa) { proxy = 1; proxydl = SDL(rt->rt_gateway); router = 0; /* XXX */ } } if (rt) rtfree(rt); } if (!ifa) { /* * We've got an NS packet, and we don't have that address * assigned for us. We MUST silently ignore it. * See RFC2461 7.2.3. */ goto freeit; } myaddr6 = *IFA_IN6(ifa); anycast = ifatoia6(ifa)->ia6_flags & IN6_IFF_ANYCAST; tentative = ifatoia6(ifa)->ia6_flags & IN6_IFF_TENTATIVE; if (ifatoia6(ifa)->ia6_flags & IN6_IFF_DUPLICATED) goto freeit; if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " "(if %d, NS packet %d)\n", inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr)), ifp->if_addrlen, lladdrlen - 2)); goto bad; } if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { log(LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", inet_ntop(AF_INET6, &saddr6, addr, sizeof(addr))); goto freeit; } /* * We have neighbor solicitation packet, with target address equals to * one of my tentative address. * * src addr how to process? * --- --- * multicast of course, invalid (rejected in ip6_input) * unicast somebody is doing address resolution -> ignore * unspec dup address detection * * The processing is defined in RFC 2462. */ if (tentative) { /* * If source address is unspecified address, it is for * duplicated address detection. * * If not, the packet is for address resolution; * silently ignore it. */ if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) nd6_dad_ns_input(ifa); goto freeit; } /* * If the source address is unspecified address, entries must not * be created or updated. * It looks that sender is performing DAD. Output NA toward * all-node multicast address, to tell the sender that I'm using * the address. * S bit ("solicited") must be zero. */ if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { saddr6 = in6addr_linklocal_allnodes; saddr6.s6_addr16[1] = htons(ifp->if_index); nd6_na_output(ifp, &saddr6, &taddr6, ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | (router ? ND_NA_FLAG_ROUTER : 0), tlladdr, (struct sockaddr *)proxydl); goto freeit; } nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0); nd6_na_output(ifp, &saddr6, &taddr6, ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | (router ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED, tlladdr, (struct sockaddr *)proxydl); freeit: m_freem(m); return; bad: nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", inet_ntop(AF_INET6, &saddr6, addr, sizeof(addr)))); nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", inet_ntop(AF_INET6, &daddr6, addr, sizeof(addr)))); nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr)))); icmp6stat.icp6s_badns++; m_freem(m); }