/* $NetBSD: nd6_nbr.c,v 1.45 2003/06/24 07:39:26 itojun Exp $ */ /* $KAME: nd6_nbr.c,v 1.61 2001/02/10 16:06:14 jinmei 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 __KERNEL_RCSID(0, "$NetBSD: nd6_nbr.c,v 1.45 2003/06/24 07:39:26 itojun Exp $"); #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 #ifdef IPSEC #include #endif #include #define SDL(s) ((struct sockaddr_dl *)s) struct dadq; static struct dadq *nd6_dad_find __P((struct ifaddr *)); static void nd6_dad_starttimer __P((struct dadq *, int)); static void nd6_dad_stoptimer __P((struct dadq *)); 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) */ 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 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; 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; 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, 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. */ /* 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; } } 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 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) { 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_flags & RTF_ANNOUNCE) != 0 && rt->rt_gateway->sa_family == AF_LINK) { /* * proxy NDP for single entry */ ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 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 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(&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(&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 = 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", 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); } /* * 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; const 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 sockaddr_in6 src_sa, dst_sa; struct ip6_moptions im6o; int icmp6len; int maxlen; caddr_t mac; struct route_in6 ro; bzero(&ro, sizeof(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; #ifdef DIAGNOSTIC if (max_linkhdr + maxlen >= MCLBYTES) { printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES " "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); panic("nd6_ns_output: insufficient MCLBYTES"); /* NOTREACHED */ } #endif MGETHDR(m, M_DONTWAIT, MT_DATA); if (m && max_linkhdr + maxlen >= MHLEN) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { m_free(m); m = NULL; } } if (m == NULL) return; m->m_pkthdr.rcvif = NULL; 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; /* determine the source and destination addresses */ bzero(&src_sa, sizeof(src_sa)); bzero(&dst_sa, sizeof(dst_sa)); src_sa.sin6_family = dst_sa.sin6_family = AF_INET6; src_sa.sin6_len = dst_sa.sin6_len = sizeof(struct sockaddr_in6); if (daddr6) dst_sa.sin6_addr = *daddr6; else { dst_sa.sin6_addr.s6_addr16[0] = IPV6_ADDR_INT16_MLL; dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index); dst_sa.sin6_addr.s6_addr32[1] = 0; dst_sa.sin6_addr.s6_addr32[2] = IPV6_ADDR_INT32_ONE; dst_sa.sin6_addr.s6_addr32[3] = taddr6->s6_addr32[3]; dst_sa.sin6_addr.s6_addr8[12] = 0xff; } ip6->ip6_dst = dst_sa.sin6_addr; if (!dad) { /* * 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 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)) src_sa.sin6_addr = *saddr6; else { struct in6_addr *src0; int error; bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); src0 = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &error); if (src0 == NULL) { nd6log((LOG_DEBUG, "nd6_ns_output: source can't be " "determined: dst=%s, error=%d\n", ip6_sprintf(&dst_sa.sin6_addr), error)); goto bad; } src_sa.sin6_addr = *src0; } } 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(&src_sa.sin6_addr, sizeof(src_sa.sin6_addr)); } ip6->ip6_src = src_sa.sin6_addr; 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 /* Don't lookup socket */ (void)ipsec_setsocket(m, NULL); #endif ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL); icmp6_ifstat_inc(ifp, ifs6_out_msg); icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++; if (ro.ro_rt) { /* we don't cache this route. */ RTFREE(ro.ro_rt); } return; bad: if (ro.ro_rt) { RTFREE(ro.ro_rt); } m_freem(m); return; } /* * Neighbor advertisement input handling. * * Based on RFC 2461 * Based on RFC 2462 (duplicated address detection) * * the following items are not implemented yet: * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) */ 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; #if 0 struct in6_addr saddr6 = ip6->ip6_src; #endif struct in6_addr daddr6 = ip6->ip6_dst; struct in6_addr taddr6; int flags; int is_router; int is_solicited; int is_override; 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) { nd6log((LOG_ERR, "nd6_na_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; } IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); if (nd_na == NULL) { icmp6stat.icp6s_tooshort++; return; } taddr6 = nd_na->nd_na_target; flags = nd_na->nd_na_flags_reserved; is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) taddr6.s6_addr16[1] = htons(ifp->if_index); if (IN6_IS_ADDR_MULTICAST(&taddr6)) { nd6log((LOG_ERR, "nd6_na_input: invalid target address %s\n", ip6_sprintf(&taddr6))); goto bad; } if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) { nd6log((LOG_ERR, "nd6_na_input: a solicited adv is multicasted\n")); goto bad; } icmp6len -= sizeof(*nd_na); nd6_option_init(nd_na + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log((LOG_INFO, "nd6_na_input: invalid ND option, ignored\n")); /* nd6_options have incremented stats */ goto freeit; } 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); goto freeit; } /* Just for safety, maybe unnecessary. */ if (ifa) { log(LOG_ERR, "nd6_na_input: duplicate IP6 address %s\n", ip6_sprintf(&taddr6)); goto freeit; } if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " "(if %d, NA packet %d)\n", ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2)); goto bad; } /* * 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)) goto freeit; 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) goto freeit; /* * 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; ln->ln_byhint = 0; if (ln->ln_expire) ln->ln_expire = time.tv_sec + ND_IFINFO(rt->rt_ifp)->reachable; } else { ln->ln_state = ND6_LLINFO_STALE; ln->ln_expire = time.tv_sec + nd6_gctimer; } if ((ln->ln_router = is_router) != 0) { /* * This means a router's state has changed from * non-reachable to probably reachable, and might * affect the status of associated prefixes.. */ pfxlist_onlink_check(); } } 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; ln->ln_expire = time.tv_sec + nd6_gctimer; } goto freeit; } 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; ln->ln_byhint = 0; if (ln->ln_expire) { ln->ln_expire = time.tv_sec + ND_IFINFO(ifp)->reachable; } } else { if (lladdr && llchange) { ln->ln_state = ND6_LLINFO_STALE; ln->ln_expire = time.tv_sec + nd6_gctimer; } } } 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; /* * Lock to protect the default router list. * XXX: this might be unnecessary, since this function * is only called under the network software interrupt * context. However, we keep it just for safety. */ 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) { /* * we assume ifp is not a loopback here, so just set the 2nd * argument as the 1st one. */ nd6_output(ifp, ifp, ln->ln_hold, (struct sockaddr_in6 *)rt_key(rt), rt); ln->ln_hold = NULL; } freeit: m_freem(m); return; bad: icmp6stat.icp6s_badna++; m_freem(m); } /* * Neighbor advertisement output handling. * * Based on RFC 2461 * * the following items are not implemented yet: * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) */ void nd6_na_output(ifp, daddr6, taddr6, flags, tlladdr, sdl0) struct ifnet *ifp; const struct in6_addr *daddr6, *taddr6; u_long flags; int tlladdr; /* 1 if include target link-layer address */ struct sockaddr *sdl0; /* sockaddr_dl (= proxy NA) or NULL */ { struct mbuf *m; struct ip6_hdr *ip6; struct nd_neighbor_advert *nd_na; struct ip6_moptions im6o; struct sockaddr_in6 src_sa, dst_sa; struct in6_addr *src0; int icmp6len, maxlen, error; caddr_t mac; struct route_in6 ro; mac = NULL; bzero(&ro, sizeof(ro)); /* estimate the size of message */ maxlen = sizeof(*ip6) + sizeof(*nd_na); maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; #ifdef DIAGNOSTIC if (max_linkhdr + maxlen >= MCLBYTES) { printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES " "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); panic("nd6_na_output: insufficient MCLBYTES"); /* NOTREACHED */ } #endif MGETHDR(m, M_DONTWAIT, MT_DATA); if (m && max_linkhdr + maxlen >= MHLEN) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { m_free(m); m = NULL; } } if (m == NULL) return; m->m_pkthdr.rcvif = NULL; 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; m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ /* 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; bzero(&src_sa, sizeof(src_sa)); bzero(&dst_sa, sizeof(dst_sa)); src_sa.sin6_len = dst_sa.sin6_len = sizeof(struct sockaddr_in6); src_sa.sin6_family = dst_sa.sin6_family = AF_INET6; dst_sa.sin6_addr = *daddr6; if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) { /* reply to DAD */ dst_sa.sin6_addr.s6_addr16[0] = IPV6_ADDR_INT16_MLL; dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index); dst_sa.sin6_addr.s6_addr32[1] = 0; dst_sa.sin6_addr.s6_addr32[2] = 0; dst_sa.sin6_addr.s6_addr32[3] = IPV6_ADDR_INT32_ONE; flags &= ~ND_NA_FLAG_SOLICITED; } ip6->ip6_dst = dst_sa.sin6_addr; /* * Select a source whose scope is the same as that of the dest. */ bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); src0 = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &error); if (src0 == NULL) { nd6log((LOG_DEBUG, "nd6_na_output: source can't be " "determined: dst=%s, error=%d\n", ip6_sprintf(&dst_sa.sin6_addr), error)); goto bad; } src_sa.sin6_addr = *src0; ip6->ip6_src = src_sa.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) { /* * sdl0 != NULL indicates proxy NA. If we do proxy, use * lladdr in sdl0. If we are not proxying (sending NA for * my address) use lladdr configured for the interface. */ if (sdl0 == NULL) mac = nd6_ifptomac(ifp); else if (sdl0->sa_family == AF_LINK) { struct sockaddr_dl *sdl; sdl = (struct sockaddr_dl *)sdl0; if (sdl->sdl_alen == ifp->if_addrlen) mac = LLADDR(sdl); } } if (tlladdr && mac) { 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 /* Don't lookup socket */ (void)ipsec_setsocket(m, NULL); #endif ip6_output(m, NULL, NULL, 0, &im6o, NULL); icmp6_ifstat_inc(ifp, ifs6_out_msg); icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++; if (ro.ro_rt) { /* we don't cache this route. */ RTFREE(ro.ro_rt); } return; bad: if (ro.ro_rt) { RTFREE(ro.ro_rt); } m_freem(m); return; } caddr_t nd6_ifptomac(ifp) struct ifnet *ifp; { switch (ifp->if_type) { case IFT_ARCNET: case IFT_ETHER: case IFT_FDDI: case IFT_IEEE1394: case IFT_PROPVIRTUAL: case IFT_L2VLAN: case IFT_IEEE80211: return LLADDR(ifp->if_sadl); 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; struct callout dad_timer_ch; }; static struct dadq_head dadq; static int dad_init = 0; 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; } static void nd6_dad_starttimer(dp, ticks) struct dadq *dp; int ticks; { callout_reset(&dp->dad_timer_ch, ticks, (void (*) __P((void *)))nd6_dad_timer, (void *)dp->dad_ifa); } static void nd6_dad_stoptimer(dp) struct dadq *dp; { callout_stop(&dp->dad_timer_ch); } /* * 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; 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)) { log(LOG_DEBUG, "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) { log(LOG_ERR, "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)); callout_init(&dp->dad_timer_ch); TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr))); /* * 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 == NULL) { nd6_dad_ns_output(dp, ifa); nd6_dad_starttimer(dp, ND6_RETRANS_SEC(ND_IFINFO(ifa->ifa_ifp)->retrans) * hz); } else { int ntick; if (*tick == 0) ntick = arc4random() % (MAX_RTR_SOLICITATION_DELAY * hz); else ntick = *tick + arc4random() % (hz / 2); *tick = ntick; nd6_dad_starttimer(dp, ntick); } } /* * terminate DAD unconditionally. used for address removals. */ void nd6_dad_stop(ifa) struct ifaddr *ifa; { struct dadq *dp; if (!dad_init) return; dp = nd6_dad_find(ifa); if (!dp) { /* DAD wasn't started yet */ return; } nd6_dad_stoptimer(dp); TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list); free(dp, M_IP6NDP); dp = NULL; IFAFREE(ifa); } 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) { log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); goto done; } dp = nd6_dad_find(ifa); if (dp == NULL) { log(LOG_ERR, "nd6_dad_timer: DAD structure not found\n"); goto done; } if (ia->ia6_flags & IN6_IFF_DUPLICATED) { log(LOG_ERR, "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) { log(LOG_ERR, "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) { nd6log((LOG_INFO, "%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); nd6_dad_starttimer(dp, ND6_RETRANS_SEC(ND_IFINFO(ifa->ifa_ifp)->retrans) * hz); } 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; nd6log((LOG_DEBUG, "%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) { log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n"); return; } log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " "NS in/out=%d/%d, NA in=%d\n", if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr), dp->dad_ns_icount, dp->dad_ns_ocount, 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) */ nd6_dad_stoptimer(dp); log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr)); log(LOG_ERR, "%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; const 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); /* Quickhack - completely ignore DAD NS packets */ if (dad_ignore_ns) { nd6log((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); }