/* $NetBSD: nd6_nbr.c,v 1.13 2000/02/01 22:52:11 thorpej Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "opt_inet.h" #include "opt_ipsec.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define SDL(s) ((struct sockaddr_dl *)s) struct dadq; static struct dadq *nd6_dad_find __P((struct ifaddr *)); static void nd6_dad_timer __P((struct ifaddr *)); static void nd6_dad_ns_output __P((struct dadq *, struct ifaddr *)); static void nd6_dad_ns_input __P((struct ifaddr *)); static void nd6_dad_na_input __P((struct ifaddr *)); static int dad_ignore_ns = 0; /* ignore NS in DAD - specwise incorrect*/ static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ /* * Input an Neighbor Solicitation Message. * * Based on RFC 2461 * Based on RFC 2462 (duplicated address detection) * * XXX proxy advertisement */ void nd6_ns_input(m, off, icmp6len) struct mbuf *m; int off, icmp6len; { struct ifnet *ifp = m->m_pkthdr.rcvif; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_neighbor_solicit *nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); struct in6_addr saddr6 = ip6->ip6_src; struct in6_addr daddr6 = ip6->ip6_dst; struct in6_addr taddr6 = nd_ns->nd_ns_target; struct in6_addr myaddr6; char *lladdr = NULL; struct ifaddr *ifa; int lladdrlen = 0; int anycast = 0, proxy = 0, tentative = 0; int tlladdr; union nd_opts ndopts; if (ip6->ip6_hlim != 255) { log(LOG_ERR, "nd6_ns_input: invalid hlim %d\n", ip6->ip6_hlim); return; } 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 { log(LOG_INFO, "nd6_ns_input: bad DAD packet " "(wrong ip6 dst)\n"); goto bad; } } if (IN6_IS_ADDR_MULTICAST(&taddr6)) { log(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) { log(LOG_INFO, "nd6_ns_input: invalid ND option, ignored\n"); goto bad; } 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) { log(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 address for which I'm offering proxy service, or * (3) "tentative" address on which DAD is being performed. */ /* (1) and (3) check. */ ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); /* (2) check. */ if (!ifa && nd6_proxyall) { 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((struct sockaddr *)&tsin6, 0); if (rt && rt->rt_ifp != ifp) { /* * search link local addr for ifp, and use it for * proxy NA. */ ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp); if (ifa) proxy = 1; } rtfree(rt); } if (!ifa) { /* * We've got a NS packet, and we don't have that adddress * assigned for us. We MUST silently ignore it. * See RFC2461 7.2.3. */ return; } 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) return; if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { log(LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " "(if %d, NS packet %d)\n", ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2); } if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { log(LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", ip6_sprintf(&saddr6)); return; } /* * 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); return; } /* * 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) | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0), tlladdr); return; } 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) | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED, tlladdr); return; bad: log(LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6)); log(LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6)); log(LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6)); return; } /* * Output an 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 (duplicated address detection) */ void nd6_ns_output(ifp, daddr6, taddr6, ln, dad) struct ifnet *ifp; struct in6_addr *daddr6, *taddr6; struct llinfo_nd6 *ln; /* for source address determination */ int dad; /* duplicated address detection */ { struct mbuf *m; struct ip6_hdr *ip6; struct nd_neighbor_solicit *nd_ns; struct in6_ifaddr *ia = NULL; struct ip6_moptions im6o; int icmp6len; caddr_t mac; struct ifnet *outif = NULL; if (IN6_IS_ADDR_MULTICAST(taddr6)) return; if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) return; 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; MH_ALIGN(m, m->m_len + 16); /* 1+1+6 is enought. but just in case */ /* 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] = htons(ifp->if_index); 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 (!dad) { #if 0 /* KAME way, exact address scope match */ /* * Select a source whose scope is the same as that of the dest. * Typically, the dest is link-local solicitation multicast * (i.e. neighbor discovery) or link-local/global unicast * (i.e. neighbor un-reachability detection). */ ia = in6_ifawithifp(ifp, &ip6->ip6_dst); if (ia == NULL) { m_freem(m); return; } ip6->ip6_src = ia->ia_addr.sin6_addr; #else /* spec-wise correct */ /* * 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 a scope-wise match. */ struct ip6_hdr *hip6; /*hold ip6*/ struct in6_addr *saddr6; if (ln && ln->ln_hold) { hip6 = mtod(ln->ln_hold, struct ip6_hdr *); /* XXX pullup? */ if (sizeof(*hip6) < ln->ln_hold->m_len) saddr6 = &hip6->ip6_src; else saddr6 = NULL; } else saddr6 = NULL; if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6)) bcopy(saddr6, &ip6->ip6_src, sizeof(*saddr6)); else { ia = in6_ifawithifp(ifp, &ip6->ip6_dst); if (ia == NULL) { m_freem(m); /*XXX*/ return; } ip6->ip6_src = ia->ia_addr.sin6_addr; } #endif } else { /* * Source address for DAD packet must always be IPv6 * unspecified address. (0::0) */ 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; if (IN6_IS_SCOPE_LINKLOCAL(&nd_ns->nd_ns_target)) nd_ns->nd_ns_target.s6_addr16[1] = 0; /* * 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 (!dad && (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); } ip6->ip6_plen = htons((u_short)icmp6len); nd_ns->nd_ns_cksum = 0; nd_ns->nd_ns_cksum = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); #ifdef IPSEC m->m_pkthdr.rcvif = NULL; #endif /*IPSEC*/ ip6_output(m, NULL, NULL, dad ? IPV6_DADOUTPUT : 0, &im6o, &outif); if (outif) { icmp6_ifstat_inc(outif, ifs6_out_msg); icmp6_ifstat_inc(outif, ifs6_out_neighborsolicit); } icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++; } /* * Neighbor advertisement input handling. * * Based on RFC 2461 * Based on RFC 2462 (duplicated address detection) */ void nd6_na_input(m, off, icmp6len) struct mbuf *m; int off, icmp6len; { struct ifnet *ifp = m->m_pkthdr.rcvif; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_neighbor_advert *nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); #if 0 struct in6_addr saddr6 = ip6->ip6_src; #endif struct in6_addr daddr6 = ip6->ip6_dst; struct in6_addr taddr6 = nd_na->nd_na_target; int flags = nd_na->nd_na_flags_reserved; int is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); int is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); int is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); char *lladdr = NULL; int lladdrlen = 0; struct ifaddr *ifa; struct llinfo_nd6 *ln; struct rtentry *rt; struct sockaddr_dl *sdl; union nd_opts ndopts; if (ip6->ip6_hlim != 255) { log(LOG_ERR, "nd6_na_input: invalid hlim %d\n", ip6->ip6_hlim); return; } if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) taddr6.s6_addr16[1] = htons(ifp->if_index); if (IN6_IS_ADDR_MULTICAST(&taddr6)) { log(LOG_ERR, "nd6_na_input: invalid target address %s\n", ip6_sprintf(&taddr6)); return; } if (IN6_IS_ADDR_MULTICAST(&daddr6)) if (is_solicited) { log(LOG_ERR, "nd6_na_input: a solicited adv is multicasted\n"); return; } icmp6len -= sizeof(*nd_na); nd6_option_init(nd_na + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { log(LOG_INFO, "nd6_na_input: invalid ND option, ignored\n"); return; } if (ndopts.nd_opts_tgt_lladdr) { lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; } ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); /* * Target address matches one of my interface address. * * If my address is tentative, this means that there's somebody * already using the same address as mine. This indicates DAD failure. * This is defined in RFC 2462. * * Otherwise, process as defined in RFC 2461. */ if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { nd6_dad_na_input(ifa); return; } /* Just for safety, maybe unnecessery. */ if (ifa) { log(LOG_ERR, "nd6_na_input: duplicate IP6 address %s\n", ip6_sprintf(&taddr6)); return; } if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { log(LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " "(if %d, NA packet %d)\n", ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2); } /* * If no neighbor cache entry is found, NA SHOULD silently be discarded. */ rt = nd6_lookup(&taddr6, 0, ifp); if ((rt == NULL) || ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) || ((sdl = SDL(rt->rt_gateway)) == NULL)) return; if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { /* * If the link-layer has address, and no lladdr option came, * discard the packet. */ if (ifp->if_addrlen && !lladdr) return; /* * Record link-layer address, and update the state. */ sdl->sdl_alen = ifp->if_addrlen; bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); if (is_solicited) { ln->ln_state = ND6_LLINFO_REACHABLE; if (ln->ln_expire) ln->ln_expire = time.tv_sec + nd_ifinfo[rt->rt_ifp->if_index].reachable; } else ln->ln_state = ND6_LLINFO_STALE; ln->ln_router = is_router; } else { int llchange; /* * Check if the link-layer address has changed or not. */ if (!lladdr) llchange = 0; else { if (sdl->sdl_alen) { if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) llchange = 1; else llchange = 0; } else llchange = 1; } /* * This is VERY complex. Look at it with care. * * override solicit lladdr llchange action * (L: record lladdr) * * 0 0 n -- (2c) * 0 0 y n (2b) L * 0 0 y y (1) REACHABLE->STALE * 0 1 n -- (2c) *->REACHABLE * 0 1 y n (2b) L *->REACHABLE * 0 1 y y (1) REACHABLE->STALE * 1 0 n -- (2a) * 1 0 y n (2a) L * 1 0 y y (2a) L *->STALE * 1 1 n -- (2a) *->REACHABLE * 1 1 y n (2a) L *->REACHABLE * 1 1 y y (2a) L *->REACHABLE */ if (!is_override && (lladdr && llchange)) { /* (1) */ /* * If state is REACHABLE, make it STALE. * no other updates should be done. */ if (ln->ln_state == ND6_LLINFO_REACHABLE) ln->ln_state = ND6_LLINFO_STALE; return; } else if (is_override /* (2a) */ || (!is_override && (lladdr && !llchange)) /* (2b) */ || !lladdr) { /* (2c) */ /* * Update link-local address, if any. */ if (lladdr) { sdl->sdl_alen = ifp->if_addrlen; bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); } /* * If solicited, make the state REACHABLE. * If not solicited and the link-layer address was * changed, make it STALE. */ if (is_solicited) { ln->ln_state = ND6_LLINFO_REACHABLE; if (ln->ln_expire) { ln->ln_expire = time.tv_sec + nd_ifinfo[ifp->if_index].reachable; } } else { if (lladdr && llchange) ln->ln_state = ND6_LLINFO_STALE; } } if (ln->ln_router && !is_router) { /* * The peer dropped the router flag. * Remove the sender from the Default Router List and * update the Destination Cache entries. */ struct nd_defrouter *dr; struct in6_addr *in6; int s; in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr; s = splsoftnet(); dr = defrouter_lookup(in6, rt->rt_ifp); if (dr) defrtrlist_del(dr); else if (!ip6_forwarding && ip6_accept_rtadv) { /* * Even if the neighbor is not in the default * router list, the neighbor may be used * as a next hop for some destinations * (e.g. redirect case). So we must * call rt6_flush explicitly. */ rt6_flush(&ip6->ip6_src, rt->rt_ifp); } splx(s); } ln->ln_router = is_router; } rt->rt_flags &= ~RTF_REJECT; ln->ln_asked = 0; if (ln->ln_hold) { #ifdef OLDIP6OUTPUT (*ifp->if_output)(ifp, ln->ln_hold, rt_key(rt), rt); #else nd6_output(ifp, ln->ln_hold, (struct sockaddr_in6 *)rt_key(rt), rt); #endif ln->ln_hold = 0; } } /* * Neighbor advertisement output handling. * * Based on RFC 2461 * * XXX NA delay for anycast address is not implemented yet * (RFC 2461 7.2.7) * XXX proxy advertisement? */ void nd6_na_output(ifp, daddr6, taddr6, flags, tlladdr) struct ifnet *ifp; struct in6_addr *daddr6, *taddr6; u_long flags; int tlladdr; /* 1 if include target link-layer address */ { struct mbuf *m; struct ip6_hdr *ip6; struct nd_neighbor_advert *nd_na; struct in6_ifaddr *ia = NULL; struct ip6_moptions im6o; int icmp6len; caddr_t mac; struct ifnet *outif = NULL; if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) return; if (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_na); m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; MH_ALIGN(m, m->m_len + 16); /* 1+1+6 is enough. but just in case */ /* fill neighbor advertisement packet */ ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_flow = 0; ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; ip6->ip6_nxt = IPPROTO_ICMPV6; ip6->ip6_hlim = 255; if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) { /* reply to DAD */ ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); ip6->ip6_dst.s6_addr32[1] = 0; ip6->ip6_dst.s6_addr32[2] = 0; ip6->ip6_dst.s6_addr32[3] = IPV6_ADDR_INT32_ONE; flags &= ~ND_NA_FLAG_SOLICITED; } else ip6->ip6_dst = *daddr6; /* * Select a source whose scope is the same as that of the dest. */ ia = in6_ifawithifp(ifp, &ip6->ip6_dst); if (ia == NULL) { m_freem(m); return; } ip6->ip6_src = ia->ia_addr.sin6_addr; nd_na = (struct nd_neighbor_advert *)(ip6 + 1); nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; nd_na->nd_na_code = 0; nd_na->nd_na_target = *taddr6; if (IN6_IS_SCOPE_LINKLOCAL(&nd_na->nd_na_target)) nd_na->nd_na_target.s6_addr16[1] = 0; /* * "tlladdr" indicates NS's condition for adding tlladdr or not. * see nd6_ns_input() for details. * Basically, if NS packet is sent to unicast/anycast addr, * target lladdr option SHOULD NOT be included. */ if (tlladdr && (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_na + 1); /* roundup to 8 bytes alignment! */ 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_TARGET_LINKADDR; nd_opt->nd_opt_len = optlen >> 3; bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); } else flags &= ~ND_NA_FLAG_OVERRIDE; ip6->ip6_plen = htons((u_short)icmp6len); nd_na->nd_na_flags_reserved = flags; nd_na->nd_na_cksum = 0; nd_na->nd_na_cksum = in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); #ifdef IPSEC m->m_pkthdr.rcvif = NULL; #endif /*IPSEC*/ ip6_output(m, NULL, NULL, 0, &im6o, &outif); if (outif) { icmp6_ifstat_inc(outif, ifs6_out_msg); icmp6_ifstat_inc(outif, ifs6_out_neighboradvert); } icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++; } caddr_t nd6_ifptomac(ifp) struct ifnet *ifp; { switch (ifp->if_type) { case IFT_ARCNET: case IFT_ETHER: case IFT_FDDI: return LLADDR(ifp->if_sadl); break; default: return NULL; } } TAILQ_HEAD(dadq_head, dadq); struct dadq { TAILQ_ENTRY(dadq) dad_list; struct ifaddr *dad_ifa; int dad_count; /* max NS to send */ int dad_ns_tcount; /* # of trials to send NS */ int dad_ns_ocount; /* NS sent so far */ int dad_ns_icount; int dad_na_icount; }; static struct dadq_head dadq; static struct dadq * nd6_dad_find(ifa) struct ifaddr *ifa; { struct dadq *dp; for (dp = dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) { if (dp->dad_ifa == ifa) return dp; } return NULL; } /* * Start Duplicated Address Detection (DAD) for specified interface address. */ void nd6_dad_start(ifa, tick) struct ifaddr *ifa; int *tick; /* minimum delay ticks for IFF_UP event */ { struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; struct dadq *dp; static int dad_init = 0; if (!dad_init) { TAILQ_INIT(&dadq); dad_init++; } /* * If we don't need DAD, don't do it. * There are several cases: * - DAD is disabled (ip6_dad_count == 0) * - the interface address is anycast */ if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { printf("nd6_dad_start: called with non-tentative address " "%s(%s)\n", ip6_sprintf(&ia->ia_addr.sin6_addr), ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); return; } if (ia->ia6_flags & IN6_IFF_ANYCAST) { ia->ia6_flags &= ~IN6_IFF_TENTATIVE; return; } if (!ip6_dad_count) { ia->ia6_flags &= ~IN6_IFF_TENTATIVE; return; } if (!ifa->ifa_ifp) panic("nd6_dad_start: ifa->ifa_ifp == NULL"); if (!(ifa->ifa_ifp->if_flags & IFF_UP)) return; if (nd6_dad_find(ifa) != NULL) { /* DAD already in progress */ return; } dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT); if (dp == NULL) { printf("nd6_dad_start: memory allocation failed for " "%s(%s)\n", ip6_sprintf(&ia->ia_addr.sin6_addr), ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); return; } bzero(dp, sizeof(*dp)); TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); #ifdef DIAGNOSTIC printf("%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr)); #endif /* * Send NS packet for DAD, ip6_dad_count times. * Note that we must delay the first transmission, if this is the * first packet to be sent from the interface after interface * (re)initialization. */ dp->dad_ifa = ifa; IFAREF(ifa); /* just for safety */ dp->dad_count = ip6_dad_count; dp->dad_ns_icount = dp->dad_na_icount = 0; dp->dad_ns_ocount = dp->dad_ns_tcount = 0; if (!tick) { nd6_dad_ns_output(dp, ifa); timeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa, nd_ifinfo[ifa->ifa_ifp->if_index].retrans * hz / 1000); } else { int ntick; if (*tick == 0) ntick = random() % (MAX_RTR_SOLICITATION_DELAY * hz); else ntick = *tick + random() % (hz / 2); *tick = ntick; timeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa, ntick); } } static void nd6_dad_timer(ifa) struct ifaddr *ifa; { int s; struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; struct dadq *dp; s = splsoftnet(); /*XXX*/ /* Sanity check */ if (ia == NULL) { printf("nd6_dad_timer: called with null parameter\n"); goto done; } dp = nd6_dad_find(ifa); if (dp == NULL) { printf("nd6_dad_timer: DAD structure not found\n"); goto done; } if (ia->ia6_flags & IN6_IFF_DUPLICATED) { printf("nd6_dad_timer: called with duplicated address " "%s(%s)\n", ip6_sprintf(&ia->ia_addr.sin6_addr), ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); goto done; } if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { printf("nd6_dad_timer: called with non-tentative address " "%s(%s)\n", ip6_sprintf(&ia->ia_addr.sin6_addr), ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); goto done; } /* timeouted with IFF_{RUNNING,UP} check */ if (dp->dad_ns_tcount > dad_maxtry) { printf("%s: could not run DAD, driver problem?\n", if_name(ifa->ifa_ifp)); TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list); free(dp, M_IP6NDP); dp = NULL; IFAFREE(ifa); goto done; } /* Need more checks? */ if (dp->dad_ns_ocount < dp->dad_count) { /* * We have more NS to go. Send NS packet for DAD. */ nd6_dad_ns_output(dp, ifa); timeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa, nd_ifinfo[ifa->ifa_ifp->if_index].retrans * hz / 1000); } else { /* * We have transmitted sufficient number of DAD packets. * See what we've got. */ int duplicate; duplicate = 0; if (dp->dad_na_icount) { /* * the check is in nd6_dad_na_input(), * but just in case */ duplicate++; } if (dp->dad_ns_icount) { #if 0 /*heuristics*/ /* * if * - we have sent many(?) DAD NS, and * - the number of NS we sent equals to the * number of NS we've got, and * - we've got no NA * we may have a faulty network card/driver which * loops back multicasts to myself. */ if (3 < dp->dad_count && dp->dad_ns_icount == dp->dad_count && dp->dad_na_icount == 0) { log(LOG_INFO, "DAD questionable for %s(%s): " "network card loops back multicast?\n", ip6_sprintf(&ia->ia_addr.sin6_addr), if_name(ifa->ifa_ifp)); /* XXX consider it a duplicate or not? */ /* duplicate++; */ } else { /* We've seen NS, means DAD has failed. */ duplicate++; } #else /* We've seen NS, means DAD has failed. */ duplicate++; #endif } if (duplicate) { /* (*dp) will be freed in nd6_dad_duplicated() */ dp = NULL; nd6_dad_duplicated(ifa); } else { /* * We are done with DAD. No NA came, no NS came. * duplicated address found. */ ia->ia6_flags &= ~IN6_IFF_TENTATIVE; printf("%s: DAD complete for %s - no duplicates " "found\n", if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr)); TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list); free(dp, M_IP6NDP); dp = NULL; IFAFREE(ifa); } } done: splx(s); } void nd6_dad_duplicated(ifa) struct ifaddr *ifa; { struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; struct dadq *dp; dp = nd6_dad_find(ifa); if (dp == NULL) { printf("nd6_dad_duplicated: DAD structure not found\n"); return; } log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: %d NS, " "%d NA\n", if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr), dp->dad_ns_icount, dp->dad_na_icount); ia->ia6_flags &= ~IN6_IFF_TENTATIVE; ia->ia6_flags |= IN6_IFF_DUPLICATED; /* We are done with DAD, with duplicated address found. (failure) */ untimeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa); printf("%s: DAD complete for %s - duplicate found\n", if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr)); printf("%s: manual intervention required\n", if_name(ifa->ifa_ifp)); TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list); free(dp, M_IP6NDP); dp = NULL; IFAFREE(ifa); } static void nd6_dad_ns_output(dp, ifa) struct dadq *dp; struct ifaddr *ifa; { struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; struct ifnet *ifp = ifa->ifa_ifp; dp->dad_ns_tcount++; if ((ifp->if_flags & IFF_UP) == 0) { #if 0 printf("%s: interface down?\n", if_name(ifp)); #endif return; } if ((ifp->if_flags & IFF_RUNNING) == 0) { #if 0 printf("%s: interface not running?\n", if_name(ifp)); #endif return; } dp->dad_ns_ocount++; nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); } static void nd6_dad_ns_input(ifa) struct ifaddr *ifa; { struct in6_ifaddr *ia; struct ifnet *ifp; struct in6_addr *taddr6; struct dadq *dp; int duplicate; if (!ifa) panic("ifa == NULL in nd6_dad_ns_input"); ia = (struct in6_ifaddr *)ifa; ifp = ifa->ifa_ifp; taddr6 = &ia->ia_addr.sin6_addr; duplicate = 0; dp = nd6_dad_find(ifa); /* * If it is from myself, ignore this. */ if (ifp && (ifp->if_flags & IFF_LOOPBACK)) return; /* Quickhack - completely ignore DAD NS packets */ if (dad_ignore_ns) { log(LOG_INFO, "nd6_dad_ns_input: ignoring DAD NS packet for " "address %s(%s)\n", ip6_sprintf(taddr6), if_name(ifa->ifa_ifp)); return; } /* * if I'm yet to start DAD, someone else started using this address * first. I have a duplicate and you win. */ if (!dp || dp->dad_ns_ocount == 0) duplicate++; /* XXX more checks for loopback situation - see nd6_dad_timer too */ if (duplicate) { dp = NULL; /* will be freed in nd6_dad_duplicated() */ nd6_dad_duplicated(ifa); } else { /* * not sure if I got a duplicate. * increment ns count and see what happens. */ if (dp) dp->dad_ns_icount++; } } static void nd6_dad_na_input(ifa) struct ifaddr *ifa; { struct dadq *dp; if (!ifa) panic("ifa == NULL in nd6_dad_na_input"); dp = nd6_dad_find(ifa); if (dp) dp->dad_na_icount++; /* remove the address. */ nd6_dad_duplicated(ifa); }