/* $NetBSD: nd6_nbr.c,v 1.183 2023/03/29 13:01:44 kardel 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 1.183 2023/03/29 13:01:44 kardel Exp $"); #ifdef _KERNEL_OPT #include "opt_inet.h" #include "opt_net_mpsafe.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "carp.h" #if NCARP > 0 #include #endif struct dadq; static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *, bool *); static bool nd6_dad_ownnonce(struct ifaddr *, struct nd_opt_nonce *nonce); static void nd6_dad_starttimer(struct dadq *, int); static void nd6_dad_destroytimer(struct dadq *); static void nd6_dad_timer(struct dadq *); static void nd6_dad_ns_output(struct dadq *, struct ifaddr *); static void nd6_dad_input(struct ifaddr *, struct nd_opt_nonce *, const struct sockaddr_dl *); static void nd6_dad_duplicated(struct ifaddr *, struct dadq *, const struct sockaddr_dl *); static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ /* * 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, *ifpc; 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; const struct sockaddr_dl *proxydl = NULL; struct psref psref; struct psref psref_c; struct psref psref_ia; char ip6buf[INET6_ADDRSTRLEN], ip6buf2[INET6_ADDRSTRLEN]; ifp = ifpc = m_get_rcvif_psref(m, &psref); if (ifp == NULL) goto freeit; IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); if (nd_ns == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); m_put_rcvif_psref(ifp, &psref); return; } 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, "invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, IN6_PRINT(ip6buf, &ip6->ip6_src), IN6_PRINT(ip6buf2, &ip6->ip6_dst), if_name(ifp)); goto bad; } if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { /* dst has to be a 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, "bad DAD packet (wrong ip6 dst)\n"); goto bad; } } else { struct sockaddr_in6 ssin6; /* * Make sure the source address is from a neighbor's address. */ sockaddr_in6_init(&ssin6, &saddr6, 0, 0, 0); if (nd6_is_addr_neighbor(&ssin6, ifp) == 0) { nd6log(LOG_INFO, "NS packet from non-neighbor %s on %s\n", IN6_PRINT(ip6buf, &saddr6), if_name(ifp)); goto bad; } } if (IN6_IS_ADDR_MULTICAST(&taddr6)) { nd6log(LOG_INFO, "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, "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, "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 multicast MUST add * Otherwise MAY be omitted * * In this implementation, we omit the target link-layer address * in the "MAY" case. */ #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. */ #if NCARP > 0 if (ifp->if_carp && ifp->if_type != IFT_CARP) { int s = pserialize_read_enter(); ifa = carp_iamatch6(ifp->if_carp, &taddr6); if (ifa != NULL) { ifa_acquire(ifa, &psref_ia); if (ifa->ifa_ifp && ifa->ifa_ifp != ifp) { ifpc = ifa->ifa_ifp; if_acquire(ifpc, &psref_c); } } pserialize_read_exit(s); } else ifa = NULL; if (!ifa) ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, &psref_ia); #else ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, &psref_ia); #endif /* (2) check. */ if (ifa == NULL) { struct rtentry *rt; struct sockaddr_in6 tsin6; sockaddr_in6_init(&tsin6, &taddr6, 0, 0, 0); rt = rtalloc1(sin6tosa(&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_psref(ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST, &psref_ia); if (ifa) { proxy = 1; proxydl = satocsdl(rt->rt_gateway); router = 0; /* XXX */ } } if (rt) rt_unref(rt); } if (ifa == NULL) { /* * 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 = ((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, "lladdrlen mismatch for %s " "(if %d, NS packet %d)\n", IN6_PRINT(ip6buf, &taddr6), ifp->if_addrlen, lladdrlen - 2); goto bad; } if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { nd6log(LOG_INFO, "duplicate IP6 address %s\n", IN6_PRINT(ip6buf, &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 address resolution; * silently ignore it. */ if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { struct sockaddr_dl sdl, *sdlp; if (lladdr != NULL) sdlp = sockaddr_dl_init(&sdl, sizeof(sdl), ifp->if_index, ifp->if_type, NULL, 0, lladdr, lladdrlen); else sdlp = NULL; nd6_dad_input(ifa, ndopts.nd_opts_nonce, sdlp); } goto freeit; } /* * It looks that sender is performing DAD. * Check that the nonce is not being used by the same address * on another interface. */ if (IN6_IS_ADDR_UNSPECIFIED(&saddr6) && ndopts.nd_opts_nonce != NULL) { if (nd6_dad_ownnonce(ifa, ndopts.nd_opts_nonce)) goto freeit; } ifa_release(ifa, &psref_ia); ifa = NULL; /* * 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(ifpc, &in6_all, &taddr6, ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0), tlladdr, (const struct sockaddr *)proxydl); goto freeit; } nd6_cache_lladdr(ifpc, &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, (const struct sockaddr *)proxydl); freeit: ifa_release(ifa, &psref_ia); m_put_rcvif_psref(ifp, &psref); if (ifp != ifpc) if_put(ifpc, &psref_c); m_freem(m); return; bad: nd6log(LOG_ERR, "src=%s\n", IN6_PRINT(ip6buf, &saddr6)); nd6log(LOG_ERR, "dst=%s\n", IN6_PRINT(ip6buf, &daddr6)); nd6log(LOG_ERR, "tgt=%s\n", IN6_PRINT(ip6buf, &taddr6)); ICMP6_STATINC(ICMP6_STAT_BADNS); ifa_release(ifa, &psref_ia); m_put_rcvif_psref(ifp, &psref); m_freem(m); } /* * 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) */ void nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, const struct in6_addr *taddr6, const struct in6_addr *hsrc, const uint8_t *nonce /* duplicate address detection */) { struct mbuf *m; struct ip6_hdr *ip6; struct nd_neighbor_solicit *nd_ns; const struct in6_addr *src; struct in6_addr src_in; struct ip6_moptions im6o; int icmp6len; int maxlen; const void *mac; struct route ro; if (IN6_IS_ADDR_MULTICAST(taddr6)) return; memset(&ro, 0, sizeof(ro)); /* estimate the size of message */ maxlen = sizeof(*ip6) + sizeof(*nd_ns); maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; KASSERTMSG(max_linkhdr + maxlen <= MCLBYTES, "max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", max_linkhdr, maxlen, MCLBYTES); 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_reset_rcvif(m); if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { m->m_flags |= M_MCAST; im6o.im6o_multicast_if_index = if_get_index(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) { int s; /* * 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 * (hsrc), if: * - hsrc is given from the caller (by giving "ln"), and * - hsrc belongs to the outgoing interface. * Otherwise, we perform the source address selection as usual. */ s = pserialize_read_enter(); if (hsrc && in6ifa_ifpwithaddr(ifp, hsrc)) { pserialize_read_exit(s); src = hsrc; } else { int error; struct sockaddr_in6 dst_sa; pserialize_read_exit(s); sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0); error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, NULL, NULL, &src_in); if (error != 0) { char ip6buf[INET6_ADDRSTRLEN]; nd6log(LOG_DEBUG, "source can't be " "determined: dst=%s, error=%d\n", IN6_PRINT(ip6buf, &dst_sa.sin6_addr), error); goto bad; } src = &src_in; } } 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. */ memset(&src_in, 0, sizeof(src_in)); src = &src_in; } ip6->ip6_src = *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; memset((void *)nd_opt, 0, optlen); nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; nd_opt->nd_opt_len = optlen >> 3; memcpy((void *)(nd_opt + 1), mac, ifp->if_addrlen); } /* Add a nonce option (RFC 3971) to detect looped back NS messages. * This behavior is documented in RFC 7527. */ if (nonce != NULL) { int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); /* 8-byte alignment is required. */ optlen = (optlen + 7) & ~7; m->m_pkthdr.len += optlen; m->m_len += optlen; icmp6len += optlen; memset(nd_opt, 0, optlen); nd_opt->nd_opt_type = ND_OPT_NONCE; nd_opt->nd_opt_len = optlen >> 3; memcpy(nd_opt + 1, nonce, ND_OPT_NONCE_LEN); } ip6->ip6_plen = htons((u_int16_t)icmp6len); nd_ns->nd_ns_cksum = 0; nd_ns->nd_ns_cksum = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); ip6_output(m, NULL, &ro, nonce != NULL ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL); icmp6_ifstat_inc(ifp, ifs6_out_msg); icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_NEIGHBOR_SOLICIT); rtcache_free(&ro); return; bad: rtcache_free(&ro); m_freem(m); return; } /* * Neighbor advertisement input handling. * * Based on RFC 2461 * Based on RFC 2462 (duplicate 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(struct mbuf *m, int off, int icmp6len) { struct ifnet *ifp; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_neighbor_advert *nd_na; struct in6_addr saddr6 = ip6->ip6_src; struct in6_addr daddr6 = ip6->ip6_dst; struct in6_addr taddr6; int flags; int is_router; int is_solicited; int is_override; int rt_cmd; char *lladdr = NULL; int lladdrlen = 0; struct ifaddr *ifa; struct llentry *ln = NULL; union nd_opts ndopts; struct sockaddr_in6 ssin6; struct psref psref; struct psref psref_ia; char ip6buf[INET6_ADDRSTRLEN], ip6buf2[INET6_ADDRSTRLEN]; ifp = m_get_rcvif_psref(m, &psref); if (ifp == NULL) goto freeit; if (ip6->ip6_hlim != 255) { nd6log(LOG_ERR, "invalid hlim (%d) from %s to %s on %s\n", ip6->ip6_hlim, IN6_PRINT(ip6buf, &ip6->ip6_src), IN6_PRINT(ip6buf2, &ip6->ip6_dst), if_name(ifp)); goto bad; } IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); if (nd_na == NULL) { m_put_rcvif_psref(ifp, &psref); ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return; } 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); taddr6 = nd_na->nd_na_target; if (in6_setscope(&taddr6, ifp, NULL)) { goto bad; } if (IN6_IS_ADDR_MULTICAST(&taddr6)) { nd6log(LOG_ERR, "invalid target address %s\n", IN6_PRINT(ip6buf, &taddr6)); goto bad; } if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) { nd6log(LOG_ERR, "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, "invalid ND option, ignored\n"); /* nd6_options have incremented stats */ goto freeit; } if (ndopts.nd_opts_tgt_lladdr != NULL) { struct ifnet *ifp_ll; struct psref psref_ll; lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { nd6log(LOG_INFO, "lladdrlen mismatch for %s " "(if %d, NA packet %d)\n", IN6_PRINT(ip6buf, &taddr6), ifp->if_addrlen, lladdrlen - 2); goto bad; } ifp_ll = if_get_bylla(lladdr, ifp->if_addrlen, &psref_ll); if (ifp_ll != NULL) { /* it's from me, ignore it. */ if_put(ifp_ll, &psref_ll); goto freeit; } } ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, &psref_ia); /* * 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) { if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE) { struct sockaddr_dl sdl, *sdlp; if (lladdr != NULL) sdlp = sockaddr_dl_init(&sdl, sizeof(sdl), ifp->if_index, ifp->if_type, NULL, 0, lladdr, lladdrlen); else sdlp = NULL; nd6_dad_input(ifa, NULL, sdlp); } else log(LOG_ERR, "nd6_na_input: duplicate IP6 address %s\n", IN6_PRINT(ip6buf, &taddr6)); ifa_release(ifa, &psref_ia); ifa = NULL; goto freeit; } /* * Make sure the source address is from a neighbor's address. */ sockaddr_in6_init(&ssin6, &saddr6, 0, 0, 0); if (nd6_is_addr_neighbor(&ssin6, ifp) == 0) { nd6log(LOG_INFO, "ND packet from non-neighbor %s on %s\n", IN6_PRINT(ip6buf, &saddr6), if_name(ifp)); goto bad; } /* * If no neighbor cache entry is found, NA SHOULD silently be * discarded. */ ln = nd6_lookup(&taddr6, ifp, true); if (ln == NULL) goto freeit; rt_cmd = 0; if (ln->ln_state <= ND_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. */ memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); ln->la_flags |= LLE_VALID; rt_cmd = RTM_ADD; if (is_solicited) { ln->ln_state = ND_LLINFO_REACHABLE; ln->ln_byhint = 0; if (!ND_IS_LLINFO_PERMANENT(ln)) nd_set_timer(ln, ND_TIMER_REACHABLE); } else { ln->ln_state = ND_LLINFO_STALE; nd_set_timer(ln, ND_TIMER_GC); } } else { bool llchange; /* * Check if the link-layer address has changed or not. */ if (lladdr == NULL) llchange = false; else { if (ln->la_flags & LLE_VALID) { if (memcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) llchange = true; else llchange = false; } else llchange = true; } if (llchange) rt_cmd = RTM_CHANGE; /* * 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 != NULL && llchange) { /* (1) */ /* * If state is REACHABLE, make it STALE. * no other updates should be done. */ if (ln->ln_state == ND_LLINFO_REACHABLE) { ln->ln_state = ND_LLINFO_STALE; nd_set_timer(ln, ND_TIMER_GC); } goto freeit; } else if (is_override /* (2a) */ || (!is_override && lladdr != NULL && !llchange) /* (2b) */ || lladdr == NULL) { /* (2c) */ /* * Update link-local address, if any. */ if (lladdr != NULL) { memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); ln->la_flags |= LLE_VALID; } /* * 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 = ND_LLINFO_REACHABLE; ln->ln_byhint = 0; if (!ND_IS_LLINFO_PERMANENT(ln)) nd_set_timer(ln, ND_TIMER_REACHABLE); } else { if (lladdr && llchange) { ln->ln_state = ND_LLINFO_STALE; nd_set_timer(ln, ND_TIMER_GC); } } } ln->ln_router = is_router; } /* * XXX: does this matter? * rt->rt_flags &= ~RTF_REJECT; */ ln->ln_asked = 0; nd6_llinfo_release_pkts(ln, ifp); if (rt_cmd != 0) { struct sockaddr_in6 sin6; sockaddr_in6_init(&sin6, &ln->r_l3addr.addr6, 0, 0, 0); rt_clonedmsg(rt_cmd, sin6tosa(&ssin6), sin6tosa(&sin6), (char *)&ln->ll_addr, ln->lle_tbl->llt_ifp); } freeit: if (ln != NULL) LLE_WUNLOCK(ln); m_put_rcvif_psref(ifp, &psref); m_freem(m); return; bad: if (ln != NULL) LLE_WUNLOCK(ln); ICMP6_STATINC(ICMP6_STAT_BADNA); m_put_rcvif_psref(ifp, &psref); 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( struct ifnet *ifp, const struct in6_addr *daddr6_0, const struct in6_addr *taddr6, u_long flags, int tlladdr, /* 1 if include target link-layer address */ const 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 *dst; union { struct sockaddr dst; struct sockaddr_in6 dst6; } u; struct in6_addr daddr6; int icmp6len, maxlen, error; const void *mac; struct route ro; mac = NULL; memset(&ro, 0, sizeof(ro)); daddr6 = *daddr6_0; /* make a local copy for modification */ /* estimate the size of message */ maxlen = sizeof(*ip6) + sizeof(*nd_na); maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; KASSERTMSG(max_linkhdr + maxlen <= MCLBYTES, "max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", max_linkhdr, maxlen, MCLBYTES); 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_reset_rcvif(m); if (IN6_IS_ADDR_MULTICAST(&daddr6)) { m->m_flags |= M_MCAST; im6o.im6o_multicast_if_index = if_get_index(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 m_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; if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { /* reply to DAD */ daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; daddr6.s6_addr16[1] = 0; daddr6.s6_addr32[1] = 0; daddr6.s6_addr32[2] = 0; daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; if (in6_setscope(&daddr6, ifp, NULL)) goto bad; flags &= ~ND_NA_FLAG_SOLICITED; } ip6->ip6_dst = daddr6; sockaddr_in6_init(&u.dst6, &daddr6, 0, 0, 0); dst = &u.dst; if (rtcache_setdst(&ro, dst) != 0) goto bad; /* * Select a source whose scope is the same as that of the dest. */ error = in6_selectsrc(satosin6(dst), NULL, NULL, &ro, NULL, NULL, NULL, &ip6->ip6_src); if (error != 0) { char ip6buf[INET6_ADDRSTRLEN]; nd6log(LOG_DEBUG, "source can't be " "determined: dst=%s, error=%d\n", IN6_PRINT(ip6buf, &satocsin6(dst)->sin6_addr), error); goto bad; } 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; in6_clearscope(&nd_na->nd_na_target); /* XXX */ /* * "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) { const struct sockaddr_dl *sdl; sdl = satocsdl(sdl0); if (sdl->sdl_alen == ifp->if_addrlen) mac = CLLADDR(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; memset((void *)nd_opt, 0, optlen); nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; nd_opt->nd_opt_len = optlen >> 3; memcpy((void *)(nd_opt + 1), mac, ifp->if_addrlen); } else flags &= ~ND_NA_FLAG_OVERRIDE; ip6->ip6_plen = htons((u_int16_t)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); ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); icmp6_ifstat_inc(ifp, ifs6_out_msg); icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_NEIGHBOR_ADVERT); rtcache_free(&ro); return; bad: rtcache_free(&ro); m_freem(m); return; } const void * nd6_ifptomac(const struct ifnet *ifp) { switch (ifp->if_type) { case IFT_ARCNET: case IFT_ETHER: case IFT_IEEE1394: case IFT_PROPVIRTUAL: case IFT_CARP: case IFT_L2VLAN: case IFT_IEEE80211: return CLLADDR(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_lcount; /* looped back NS */ struct callout dad_timer_ch; #define ND_OPT_NONCE_STORE 3 /* dad_count should not exceed this */ /* * The default ip6_dad_count is 1 as specified by RFC 4862 and * practically must users won't exceed this. * A storage of 3 is defaulted to here, in-case the administrator wants * to match the equivalent behaviour in our ARP implementation. * This constraint could be removed by sending the on wire nonce as * hmac(key, dad_ns_ocount), but that would increase the nonce size * sent on the wire. */ uint8_t dad_nonce[ND_OPT_NONCE_STORE][ND_OPT_NONCE_LEN]; }; static struct dadq_head dadq; static kmutex_t nd6_dad_lock; void nd6_nbr_init(void) { TAILQ_INIT(&dadq); mutex_init(&nd6_dad_lock, MUTEX_DEFAULT, IPL_NONE); } static struct dadq * nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *nonce, bool *found_nonce) { struct in6_addr *myaddr6, *dadaddr6; bool match_ifa; struct dadq *dp; int i, nonce_max; KASSERT(mutex_owned(&nd6_dad_lock)); KASSERT(ifa != NULL); myaddr6 = IFA_IN6(ifa); if (nonce != NULL && nonce->nd_opt_nonce_len != (ND_OPT_NONCE_LEN + 2) / 8) nonce = NULL; match_ifa = nonce == NULL || found_nonce == NULL || *found_nonce == false; if (found_nonce != NULL) *found_nonce = false; TAILQ_FOREACH(dp, &dadq, dad_list) { if (match_ifa) { if (dp->dad_ifa != ifa) continue; } else { dadaddr6 = IFA_IN6(dp->dad_ifa); if (!IN6_ARE_ADDR_EQUAL(myaddr6, dadaddr6)) continue; } if (nonce == NULL) break; nonce_max = MIN(dp->dad_ns_ocount, ND_OPT_NONCE_STORE); for (i = 0; i < nonce_max; i++) { if (memcmp(nonce->nd_opt_nonce, dp->dad_nonce[i], ND_OPT_NONCE_LEN) == 0) break; } if (i < nonce_max) { char ip6buf[INET6_ADDRSTRLEN]; *found_nonce = true; log(LOG_DEBUG, "%s: detected a looped back NS message for %s\n", if_name(ifa->ifa_ifp), IN6_PRINT(ip6buf, myaddr6)); dp->dad_ns_lcount++; continue; } break; } return dp; } static bool nd6_dad_ownnonce(struct ifaddr *ifa, struct nd_opt_nonce *nonce) { bool found_nonce = true; mutex_enter(&nd6_dad_lock); nd6_dad_find(ifa, nonce, &found_nonce); mutex_exit(&nd6_dad_lock); return found_nonce; } static void nd6_dad_starttimer(struct dadq *dp, int ticks) { callout_reset(&dp->dad_timer_ch, ticks, (void (*)(void *))nd6_dad_timer, dp); } static void nd6_dad_stoptimer(struct dadq *dp) { KASSERT(mutex_owned(&nd6_dad_lock)); TAILQ_REMOVE(&dadq, dp, dad_list); /* Tell the timer that dp is being destroyed. */ dp->dad_ifa = NULL; callout_halt(&dp->dad_timer_ch, &nd6_dad_lock); } static void nd6_dad_destroytimer(struct dadq *dp) { KASSERT(dp->dad_ifa == NULL); callout_destroy(&dp->dad_timer_ch); kmem_intr_free(dp, sizeof(*dp)); } /* * Start Duplicate Address Detection (DAD) for specified interface address. * * Note that callout is used when xtick > 0 and not when xtick == 0. * * xtick: minimum delay ticks for IFF_UP event */ void nd6_dad_start(struct ifaddr *ifa, int xtick) { struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; struct dadq *dp; char ip6buf[INET6_ADDRSTRLEN]; /* * If we don't need DAD, don't do it. * There are several cases: * - DAD is disabled * - 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", IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), if_name(ifa->ifa_ifp)); return; } if (ia->ia6_flags & IN6_IFF_ANYCAST || !ip6_dad_enabled()) { ia->ia6_flags &= ~IN6_IFF_TENTATIVE; rt_addrmsg(RTM_NEWADDR, ifa); return; } if (!(ifa->ifa_ifp->if_flags & IFF_UP)) return; dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); mutex_enter(&nd6_dad_lock); if (nd6_dad_find(ifa, NULL, NULL) != NULL) { mutex_exit(&nd6_dad_lock); /* DAD already in progress */ if (dp != NULL) kmem_intr_free(dp, sizeof(*dp)); return; } if (dp == NULL) { mutex_exit(&nd6_dad_lock); log(LOG_ERR, "nd6_dad_start: memory allocation failed for " "%s(%s)\n", IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), if_name(ifa->ifa_ifp)); return; } /* * 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. */ callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); dp->dad_ifa = ifa; ifaref(ifa); /* just for safety */ dp->dad_count = ip6_dad_count; dp->dad_ns_ocount = dp->dad_ns_tcount = 0; dp->dad_ns_lcount = 0; TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); nd6log(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); if (xtick == 0) { nd6_dad_ns_output(dp, ifa); nd6_dad_starttimer(dp, (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); } else nd6_dad_starttimer(dp, xtick); mutex_exit(&nd6_dad_lock); } /* * terminate DAD unconditionally. used for address removals. */ void nd6_dad_stop(struct ifaddr *ifa) { struct dadq *dp; mutex_enter(&nd6_dad_lock); dp = nd6_dad_find(ifa, NULL, NULL); if (dp == NULL) { mutex_exit(&nd6_dad_lock); /* DAD wasn't started yet */ return; } /* Prevent the timer from running anymore. */ nd6_dad_stoptimer(dp); mutex_exit(&nd6_dad_lock); nd6_dad_destroytimer(dp); ifafree(ifa); } static void nd6_dad_timer(struct dadq *dp) { struct ifaddr *ifa; struct in6_ifaddr *ia; char ip6buf[INET6_ADDRSTRLEN]; bool need_free = false; KERNEL_LOCK_UNLESS_NET_MPSAFE(); mutex_enter(&nd6_dad_lock); ifa = dp->dad_ifa; if (ifa == NULL) { /* dp is being destroyed by someone. Do nothing. */ goto done; } ia = (struct in6_ifaddr *)ifa; if (ia->ia6_flags & IN6_IFF_DUPLICATED) { log(LOG_ERR, "nd6_dad_timer: called with duplicate address " "%s(%s)\n", IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 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", IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 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)); nd6_dad_stoptimer(dp); need_free = true; 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, (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); } else { /* * We are done with DAD. No NA came, no NS came. * No duplicate address found. */ ia->ia6_flags &= ~IN6_IFF_TENTATIVE; rt_addrmsg(RTM_NEWADDR, ifa); nd6log(LOG_DEBUG, "%s: DAD complete for %s - no duplicates found\n", if_name(ifa->ifa_ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); nd6_dad_stoptimer(dp); need_free = true; } done: mutex_exit(&nd6_dad_lock); if (need_free) { nd6_dad_destroytimer(dp); KASSERT(ifa != NULL); ifafree(ifa); } KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); } static void nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp, const struct sockaddr_dl *from) { struct in6_ifaddr *ia; struct ifnet *ifp; char ip6buf[INET6_ADDRSTRLEN], llabuf[LLA_ADDRSTRLEN], *llastr; KASSERT(mutex_owned(&nd6_dad_lock)); KASSERT(ifa != NULL); ifp = ifa->ifa_ifp; ia = (struct in6_ifaddr *)ifa; ia->ia6_flags &= ~IN6_IFF_TENTATIVE; ia->ia6_flags |= IN6_IFF_DUPLICATED; if (__predict_false(from == NULL)) llastr = NULL; else llastr = lla_snprintf(llabuf, sizeof(llabuf), CLLADDR(from), from->sdl_alen); log(LOG_ERR, "%s: DAD duplicate address %s from %s\n", if_name(ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), llastr); /* Inform the routing socket that DAD has completed */ rt_addrmsg_src(RTM_NEWADDR, ifa, (const struct sockaddr *)from); /* * If the address is a link-local address formed from an interface * identifier based on the hardware address which is supposed to be * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP * operation on the interface SHOULD be disabled. * [rfc2462bis-03 Section 5.4.5] */ if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { struct in6_addr in6; /* * To avoid over-reaction, we only apply this logic when we are * very sure that hardware addresses are supposed to be unique. */ switch (ifp->if_type) { case IFT_ETHER: case IFT_ATM: case IFT_IEEE1394: case IFT_IEEE80211: in6 = ia->ia_addr.sin6_addr; if (in6_get_hw_ifid(ifp, &in6) == 0 && IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; log(LOG_ERR, "%s: possible hardware address " "duplication detected, disable IPv6\n", if_name(ifp)); } break; } } } static void nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) { struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; struct ifnet *ifp = ifa->ifa_ifp; uint8_t *nonce; 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_tcount = 0; nonce = dp->dad_nonce[dp->dad_ns_ocount % ND_OPT_NONCE_STORE]; cprng_fast(nonce, ND_OPT_NONCE_LEN); dp->dad_ns_ocount++; nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, nonce); } static void nd6_dad_input(struct ifaddr *ifa, struct nd_opt_nonce *nonce, const struct sockaddr_dl *from) { struct dadq *dp; bool found_nonce = false; KASSERT(ifa != NULL); mutex_enter(&nd6_dad_lock); dp = nd6_dad_find(ifa, nonce, &found_nonce); if (!found_nonce) { nd6_dad_duplicated(ifa, dp, from); if (dp != NULL) nd6_dad_stoptimer(dp); } mutex_exit(&nd6_dad_lock); if (dp != NULL) { nd6_dad_destroytimer(dp); ifafree(ifa); } }