/* $OpenBSD: in6_ifattach.c,v 1.69 2014/05/20 10:29:01 mpi Exp $ */ /* $KAME: in6_ifattach.c,v 1.124 2001/07/18 08:32:51 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef MROUTING #include #endif #include unsigned long in6_maxmtu = 0; int ip6_auto_linklocal = 1; /* enable by default */ int get_last_resort_ifid(struct ifnet *, struct in6_addr *); int get_hw_ifid(struct ifnet *, struct in6_addr *); int get_ifid(struct ifnet *, struct in6_addr *); int in6_ifattach_loopback(struct ifnet *); #define EUI64_GBIT 0x01 #define EUI64_UBIT 0x02 #define EUI64_TO_IFID(in6) do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0) #define EUI64_GROUP(in6) ((in6)->s6_addr[8] & EUI64_GBIT) #define EUI64_INDIVIDUAL(in6) (!EUI64_GROUP(in6)) #define EUI64_LOCAL(in6) ((in6)->s6_addr[8] & EUI64_UBIT) #define EUI64_UNIVERSAL(in6) (!EUI64_LOCAL(in6)) #define IFID_LOCAL(in6) (!EUI64_LOCAL(in6)) #define IFID_UNIVERSAL(in6) (!EUI64_UNIVERSAL(in6)) /* * Generate a last-resort interface identifier, when the machine has no * IEEE802/EUI64 address sources. * The goal here is to get an interface identifier that is * (1) random enough and (2) does not change across reboot. * We currently use MD5(hostname) for it. * * in6 - upper 64bits are preserved */ int get_last_resort_ifid(struct ifnet *ifp, struct in6_addr *in6) { MD5_CTX ctxt; u_int8_t digest[16]; #if 0 /* we need at least several letters as seed for ifid */ if (hostnamelen < 3) return -1; #endif /* generate 8 bytes of pseudo-random value. */ bzero(&ctxt, sizeof(ctxt)); MD5Init(&ctxt); MD5Update(&ctxt, hostname, hostnamelen); MD5Final(digest, &ctxt); /* assumes sizeof(digest) > sizeof(ifid) */ bcopy(digest, &in6->s6_addr[8], 8); /* make sure to set "u" bit to local, and "g" bit to individual. */ in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */ in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */ /* convert EUI64 into IPv6 interface identifier */ EUI64_TO_IFID(in6); return 0; } /* * Generate a random interface identifier. * * in6 - upper 64bits are preserved */ void in6_get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6) { arc4random_buf(&in6->s6_addr32[2], 8); /* make sure to set "u" bit to local, and "g" bit to individual. */ in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */ in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */ /* convert EUI64 into IPv6 interface identifier */ EUI64_TO_IFID(in6); } /* * Get interface identifier for the specified interface. * * in6 - upper 64bits are preserved */ int get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6) { struct sockaddr_dl *sdl; char *addr; size_t addrlen; static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; static u_int8_t allone[8] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; sdl = (struct sockaddr_dl *)ifp->if_sadl; if (sdl == NULL || sdl->sdl_alen == 0) return -1; addr = LLADDR(sdl); addrlen = sdl->sdl_alen; switch (ifp->if_type) { case IFT_IEEE1394: case IFT_IEEE80211: /* IEEE1394 uses 16byte length address starting with EUI64 */ if (addrlen > 8) addrlen = 8; break; default: break; } /* get EUI64 */ switch (ifp->if_type) { /* IEEE802/EUI64 cases - what others? */ case IFT_ETHER: case IFT_CARP: case IFT_IEEE1394: case IFT_IEEE80211: /* look at IEEE802/EUI64 only */ if (addrlen != 8 && addrlen != 6) return -1; /* * check for invalid MAC address - on bsdi, we see it a lot * since wildboar configures all-zero MAC on pccard before * card insertion. */ if (bcmp(addr, allzero, addrlen) == 0) return -1; if (bcmp(addr, allone, addrlen) == 0) return -1; /* make EUI64 address */ if (addrlen == 8) bcopy(addr, &in6->s6_addr[8], 8); else if (addrlen == 6) { in6->s6_addr[8] = addr[0]; in6->s6_addr[9] = addr[1]; in6->s6_addr[10] = addr[2]; in6->s6_addr[11] = 0xff; in6->s6_addr[12] = 0xfe; in6->s6_addr[13] = addr[3]; in6->s6_addr[14] = addr[4]; in6->s6_addr[15] = addr[5]; } break; case IFT_GIF: /* * RFC2893 says: "SHOULD use IPv4 address as ifid source". * however, IPv4 address is not very suitable as unique * identifier source (can be renumbered). * we don't do this. */ return -1; default: return -1; } /* sanity check: g bit must not indicate "group" */ if (EUI64_GROUP(in6)) return -1; /* convert EUI64 into IPv6 interface identifier */ EUI64_TO_IFID(in6); /* * sanity check: ifid must not be all zero, avoid conflict with * subnet router anycast */ if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 && bcmp(&in6->s6_addr[9], allzero, 7) == 0) { return -1; } return 0; } /* * Get interface identifier for the specified interface. If it is not * available on ifp0, borrow interface identifier from other information * sources. */ int get_ifid(struct ifnet *ifp0, struct in6_addr *in6) { struct ifnet *ifp; /* first, try to get it from the interface itself */ if (get_hw_ifid(ifp0, in6) == 0) { nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n", ifp0->if_xname)); goto success; } /* next, try to get it from some other hardware interface */ TAILQ_FOREACH(ifp, &ifnet, if_list) { if (ifp == ifp0) continue; if (get_hw_ifid(ifp, in6) != 0) continue; /* * to borrow ifid from other interface, ifid needs to be * globally unique */ if (IFID_UNIVERSAL(in6)) { nd6log((LOG_DEBUG, "%s: borrow interface identifier from %s\n", ifp0->if_xname, ifp->if_xname)); goto success; } } /* last resort: get from random number source */ if (get_last_resort_ifid(ifp, in6) == 0) { nd6log((LOG_DEBUG, "%s: interface identifier generated by random number\n", ifp0->if_xname)); goto success; } printf("%s: failed to get interface identifier\n", ifp0->if_xname); return -1; success: nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n", ifp0->if_xname, in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10], in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13], in6->s6_addr[14], in6->s6_addr[15])); return 0; } /* * ifid - used as EUI64 if not NULL, overrides other EUI64 sources */ int in6_ifattach_linklocal(struct ifnet *ifp, struct in6_addr *ifid) { struct in6_ifaddr *ia6; struct in6_aliasreq ifra; struct nd_prefix pr0; int i, s, error; /* * configure link-local address. */ bzero(&ifra, sizeof(ifra)); /* * in6_update_ifa() does not use ifra_name, but we accurately set it * for safety. */ strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); ifra.ifra_addr.sin6_family = AF_INET6; ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; if ((ifp->if_flags & IFF_LOOPBACK) != 0) { ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0; ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1); } else if (ifid) { ifra.ifra_addr.sin6_addr = *ifid; ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; ifra.ifra_addr.sin6_addr.s6_addr[8] &= ~EUI64_GBIT; ifra.ifra_addr.sin6_addr.s6_addr[8] |= EUI64_UBIT; } else { if (get_ifid(ifp, &ifra.ifra_addr.sin6_addr) != 0) { nd6log((LOG_ERR, "%s: no ifid available\n", ifp->if_xname)); return (-1); } } ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); ifra.ifra_prefixmask.sin6_family = AF_INET6; ifra.ifra_prefixmask.sin6_addr = in6mask64; /* link-local addresses should NEVER expire. */ ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; /* * Do not let in6_update_ifa() do DAD, since we need a random delay * before sending an NS at the first time the interface becomes up. * Instead, in6_if_up() will start DAD with a proper random delay. */ ifra.ifra_flags |= IN6_IFF_NODAD; /* * Now call in6_update_ifa() to do a bunch of procedures to configure * a link-local address. In the case of CARP, we may be called after * one has already been configured, so check if it's already there * with in6ifa_ifpforlinklocal() and clobber it if it exists. */ s = splsoftnet(); error = in6_update_ifa(ifp, &ifra, in6ifa_ifpforlinklocal(ifp, 0)); splx(s); if (error != 0) { /* * XXX: When the interface does not support IPv6, this call * would fail in the SIOCSIFADDR ioctl. I believe the * notification is rather confusing in this case, so just * suppress it. (jinmei@kame.net 20010130) */ if (error != EAFNOSUPPORT) nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to " "configure a link-local address on %s " "(errno=%d)\n", ifp->if_xname, error)); return (-1); } /* * Adjust ia6_flags so that in6_if_up will perform DAD. * XXX: Some P2P interfaces seem not to send packets just after * becoming up, so we skip p2p interfaces for safety. */ ia6 = in6ifa_ifpforlinklocal(ifp, 0); /* ia6 must not be NULL */ #ifdef DIAGNOSTIC if (!ia6) { panic("ia6 == NULL in in6_ifattach_linklocal"); /* NOTREACHED */ } #endif if (in6if_do_dad(ifp) && ((ifp->if_flags & IFF_POINTOPOINT) || (ifp->if_type == IFT_CARP)) == 0) { ia6->ia6_flags &= ~IN6_IFF_NODAD; ia6->ia6_flags |= IN6_IFF_TENTATIVE; } /* * Make the link-local prefix (fe80::/64%link) as on-link. * Since we'd like to manage prefixes separately from addresses, * we make an ND6 prefix structure for the link-local prefix, * and add it to the prefix list as a never-expire prefix. * XXX: this change might affect some existing code base... */ bzero(&pr0, sizeof(pr0)); pr0.ndpr_ifp = ifp; /* this should be 64 at this moment. */ pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL); pr0.ndpr_mask = ifra.ifra_prefixmask.sin6_addr; pr0.ndpr_prefix = ifra.ifra_addr; /* apply the mask for safety. (nd6_prelist_add will apply it again) */ for (i = 0; i < 4; i++) { pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &= in6mask64.s6_addr32[i]; } /* * Initialize parameters. The link-local prefix must always be * on-link, and its lifetimes never expire. */ pr0.ndpr_raf_onlink = 1; pr0.ndpr_raf_auto = 1; /* probably meaningless */ pr0.ndpr_vltime = ND6_INFINITE_LIFETIME; pr0.ndpr_pltime = ND6_INFINITE_LIFETIME; /* * Since there is no other link-local addresses, nd6_prefix_lookup() * probably returns NULL. However, we cannot always expect the result. * For example, if we first remove the (only) existing link-local * address, and then reconfigure another one, the prefix is still * valid with referring to the old link-local address. */ if (nd6_prefix_lookup(&pr0) == NULL) { if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0) return (error); } return 0; } /* * ifp - must be IFT_LOOP */ int in6_ifattach_loopback(struct ifnet *ifp) { struct in6_aliasreq ifra; int error; bzero(&ifra, sizeof(ifra)); /* * in6_update_ifa() does not use ifra_name, but we accurately set it * for safety. */ strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); ifra.ifra_prefixmask.sin6_family = AF_INET6; ifra.ifra_prefixmask.sin6_addr = in6mask128; /* * Always initialize ia_dstaddr (= broadcast address) to loopback * address. Follows IPv4 practice - see in_ifinit(). */ ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6); ifra.ifra_dstaddr.sin6_family = AF_INET6; ifra.ifra_dstaddr.sin6_addr = in6addr_loopback; ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); ifra.ifra_addr.sin6_family = AF_INET6; ifra.ifra_addr.sin6_addr = in6addr_loopback; /* the loopback address should NEVER expire. */ ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; /* we don't need to perform DAD on loopback interfaces. */ ifra.ifra_flags |= IN6_IFF_NODAD; /* * We are sure that this is a newly assigned address, so we can set * NULL to the 3rd arg. */ if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) { nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure " "the loopback address on %s (errno=%d)\n", ifp->if_xname, error)); return (-1); } return 0; } /* * compute NI group address, based on the current hostname setting. * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later). * * when ifp == NULL, the caller is responsible for filling scopeid. */ int in6_nigroup(struct ifnet *ifp, const char *name, int namelen, struct sockaddr_in6 *sa6) { const char *p; u_int8_t *q; MD5_CTX ctxt; u_int8_t digest[16]; u_int8_t l; u_int8_t n[64]; /* a single label must not exceed 63 chars */ if (!namelen || !name) return -1; p = name; while (p && *p && *p != '.' && p - name < namelen) p++; if (p - name > sizeof(n) - 1) return -1; /* label too long */ l = p - name; strncpy((char *)n, name, l); n[(int)l] = '\0'; for (q = n; *q; q++) { if ('A' <= *q && *q <= 'Z') *q = *q - 'A' + 'a'; } /* generate 8 bytes of pseudo-random value. */ bzero(&ctxt, sizeof(ctxt)); MD5Init(&ctxt); MD5Update(&ctxt, &l, sizeof(l)); MD5Update(&ctxt, n, l); MD5Final(digest, &ctxt); bzero(sa6, sizeof(*sa6)); sa6->sin6_family = AF_INET6; sa6->sin6_len = sizeof(*sa6); sa6->sin6_addr.s6_addr16[0] = htons(0xff02); sa6->sin6_addr.s6_addr16[1] = htons(ifp->if_index); sa6->sin6_addr.s6_addr8[11] = 2; bcopy(digest, &sa6->sin6_addr.s6_addr32[3], sizeof(sa6->sin6_addr.s6_addr32[3])); return 0; } /* * XXX multiple loopback interface needs more care. for instance, * nodelocal address needs to be configured onto only one of them. * XXX multiple link-local address case */ void in6_ifattach(struct ifnet *ifp) { struct in6_ifaddr *ia6; struct in6_addr in6; /* some of the interfaces are inherently not IPv6 capable */ switch (ifp->if_type) { case IFT_BRIDGE: case IFT_ENC: case IFT_PFLOG: case IFT_PFSYNC: return; } /* * if link mtu is too small, don't try to configure IPv6. * remember there could be some link-layer that has special * fragmentation logic. */ if (ifp->if_mtu < IPV6_MMTU) { nd6log((LOG_INFO, "in6_ifattach: " "%s has too small MTU, IPv6 not enabled\n", ifp->if_xname)); return; } /* * quirks based on interface type */ switch (ifp->if_type) { /* we attach a link-local address when a vhid is assigned */ case IFT_CARP: return; default: break; } /* * usually, we require multicast capability to the interface */ if ((ifp->if_flags & IFF_MULTICAST) == 0) { nd6log((LOG_INFO, "in6_ifattach: " "%s is not multicast capable, IPv6 not enabled\n", ifp->if_xname)); return; } /* * assign loopback address for loopback interface. * XXX multiple loopback interface case. */ if ((ifp->if_flags & IFF_LOOPBACK) != 0) { in6 = in6addr_loopback; if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) { if (in6_ifattach_loopback(ifp) != 0) return; } } /* * assign a link-local address, if there's none. */ if (ip6_auto_linklocal) { ia6 = in6ifa_ifpforlinklocal(ifp, 0); if (ia6 == NULL) { if (in6_ifattach_linklocal(ifp, NULL) == 0) { /* linklocal address assigned */ } else { /* failed to assign linklocal address. bark? */ } } } } /* * NOTE: in6_ifdetach() does not support loopback if at this moment. */ void in6_ifdetach(struct ifnet *ifp) { struct ifaddr *ifa, *next; struct rtentry *rt; struct sockaddr_in6 sin6; #ifdef MROUTING /* remove ip6_mrouter stuff */ ip6_mrouter_detach(ifp); #endif /* remove neighbor management table */ nd6_purge(ifp); /* nuke any of IPv6 addresses we have */ TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, next) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; in6_purgeaddr(ifa); } /* * remove neighbor management table. we call it twice just to make * sure we nuke everything. maybe we need just one call. * XXX: since the first call did not release addresses, some prefixes * might remain. We should call nd6_purge() again to release the * prefixes after removing all addresses above. * (Or can we just delay calling nd6_purge until at this point?) */ nd6_purge(ifp); /* remove route to interface local allnodes multicast (ff01::1) */ bzero(&sin6, sizeof(sin6)); sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_family = AF_INET6; sin6.sin6_addr = in6addr_intfacelocal_allnodes; sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); rt = rtalloc1(sin6tosa(&sin6), 0, ifp->if_rdomain); if (rt && rt->rt_ifp == ifp) { struct rt_addrinfo info; bzero(&info, sizeof(info)); info.rti_flags = rt->rt_flags; info.rti_info[RTAX_DST] = rt_key(rt); info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; info.rti_info[RTAX_NETMASK] = rt_mask(rt); rtrequest1(RTM_DELETE, &info, rt->rt_priority, NULL, ifp->if_rdomain); rtfree(rt); } /* remove route to link-local allnodes multicast (ff02::1) */ bzero(&sin6, sizeof(sin6)); sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_family = AF_INET6; sin6.sin6_addr = in6addr_linklocal_allnodes; sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); rt = rtalloc1(sin6tosa(&sin6), 0, ifp->if_rdomain); if (rt && rt->rt_ifp == ifp) { struct rt_addrinfo info; bzero(&info, sizeof(info)); info.rti_flags = rt->rt_flags; info.rti_info[RTAX_DST] = rt_key(rt); info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; info.rti_info[RTAX_NETMASK] = rt_mask(rt); rtrequest1(RTM_DELETE, &info, rt->rt_priority, NULL, ifp->if_rdomain); rtfree(rt); } }