/* $NetBSD: in6_ifattach.c,v 1.120.12.1 2024/04/18 16:22:28 martin 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 __KERNEL_RCSID(0, "$NetBSD: in6_ifattach.c,v 1.120.12.1 2024/04/18 16:22:28 martin Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include int ip6_auto_linklocal = 1; /* enable by default */ #if 0 static int get_hostid_ifid(struct ifnet *, struct in6_addr *); #endif static int get_ifid(struct ifnet *, struct ifnet *, struct in6_addr *); static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *); static 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 (/*CONSTCOND*/ 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)) #if 0 /* * Generate a last-resort interface identifier from hostid. * works only for certain architectures (like sparc). * also, using hostid itself may constitute a privacy threat, much worse * than MAC addresses (hostids are used for software licensing). * maybe we should use MD5(hostid) instead. * * in6 - upper 64bits are preserved */ static int get_hostid_ifid(struct ifnet *ifp, struct in6_addr *in6) { int off, len; static const uint8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; static const uint8_t allone[8] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; if (!hostid) return -1; /* get up to 8 bytes from the hostid field - should we get */ len = (sizeof(hostid) > 8) ? 8 : sizeof(hostid); off = sizeof(*in6) - len; memcpy(&in6->s6_addr[off], &hostid, len); /* make sure we do not return anything bogus */ if (memcmp(&in6->s6_addr[8], allzero, sizeof(allzero))) return -1; if (memcmp(&in6->s6_addr[8], allone, sizeof(allone))) return -1; /* 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; } #endif /* * 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. */ static int get_rand_ifid(struct in6_addr *in6) /* upper 64bits are preserved */ { 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. */ memset(&ctxt, 0, sizeof(ctxt)); MD5Init(&ctxt); MD5Update(&ctxt, (u_char *)hostname, hostnamelen); MD5Final(digest, &ctxt); /* assumes sizeof(digest) > sizeof(ifid) */ memcpy(&in6->s6_addr[8], digest, 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; } /* * Get interface identifier for the specified interface. * * in6 - upper 64bits are preserved */ int in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6) { struct ifaddr *ifa; const struct sockaddr_dl *sdl = NULL; const char *addr = NULL; /* XXX gcc 4.8 -Werror=maybe-uninitialized */ size_t addrlen = 0; /* XXX gcc 4.8 -Werror=maybe-uninitialized */ 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 }; int s; s = pserialize_read_enter(); IFADDR_READER_FOREACH(ifa, ifp) { const struct sockaddr_dl *tsdl; if (ifa->ifa_addr->sa_family != AF_LINK) continue; tsdl = satocsdl(ifa->ifa_addr); if (tsdl == NULL || tsdl->sdl_alen == 0) continue; if (sdl == NULL || ifa == ifp->if_dl || ifa == ifp->if_hwdl) { sdl = tsdl; addr = CLLADDR(sdl); addrlen = sdl->sdl_alen; } if (ifa == ifp->if_hwdl) break; } pserialize_read_exit(s); if (sdl == NULL) return -1; 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_ATM: 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 (memcmp(addr, allzero, addrlen) == 0) return -1; if (memcmp(addr, allone, addrlen) == 0) return -1; /* make EUI64 address */ if (addrlen == 8) memcpy(&in6->s6_addr[8], addr, 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_ARCNET: if (addrlen != 1) return -1; if (!addr[0]) return -1; memset(&in6->s6_addr[8], 0, 8); in6->s6_addr[15] = addr[0]; /* * due to insufficient bitwidth, we mark it local. */ in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */ in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */ break; case IFT_GIF: case IFT_IPSEC: #ifdef IFT_STF case IFT_STF: #endif /* * 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 && memcmp(&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. * * altifp - secondary EUI64 source */ static int get_ifid(struct ifnet *ifp0, struct ifnet *altifp, struct in6_addr *in6) { struct ifnet *ifp; int s; /* first, try to get it from the interface itself */ if (in6_get_hw_ifid(ifp0, in6) == 0) { nd6log(LOG_DEBUG, "%s: got interface identifier from itself\n", if_name(ifp0)); goto success; } /* try secondary EUI64 source. this basically is for ATM PVC */ if (altifp && in6_get_hw_ifid(altifp, in6) == 0) { nd6log(LOG_DEBUG, "%s: got interface identifier from %s\n", if_name(ifp0), if_name(altifp)); goto success; } /* next, try to get it from some other hardware interface */ s = pserialize_read_enter(); IFNET_READER_FOREACH(ifp) { if (ifp == ifp0) continue; if (in6_get_hw_ifid(ifp, in6) != 0) continue; /* * to borrow ifid from other interface, ifid needs to be * globally unique */ if (IFID_UNIVERSAL(in6)) { nd6log(LOG_DEBUG, "%s: borrow interface identifier from %s\n", if_name(ifp0), if_name(ifp)); pserialize_read_exit(s); goto success; } } pserialize_read_exit(s); #if 0 /* get from hostid - only for certain architectures */ if (get_hostid_ifid(ifp, in6) == 0) { nd6log(LOG_DEBUG, "%s: interface identifier generated by hostid\n", if_name(ifp0)); goto success; } #endif /* last resort: get from random number source */ if (get_rand_ifid(in6) == 0) { nd6log(LOG_DEBUG, "%s: interface identifier generated by random number\n", if_name(ifp0)); goto success; } printf("%s: failed to get interface identifier\n", if_name(ifp0)); return -1; success: nd6log(LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n", if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10], in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13], in6->s6_addr[14], in6->s6_addr[15]); return 0; } /* * altifp - secondary EUI64 source */ static int in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp) { struct in6_aliasreq ifra; int error; /* * configure link-local address. */ memset(&ifra, 0, sizeof(ifra)); /* * in6_update_ifa() does not use ifra_name, but we accurately set it * for safety. */ strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name)); ifra.ifra_addr.sin6_family = AF_INET6; ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000); ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; if ((ifp->if_flags & IFF_LOOPBACK) != 0) { ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0; ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1); } else { if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) { nd6log(LOG_ERR, "%s: no ifid available\n", if_name(ifp)); return -1; } } if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL)) return -1; sockaddr_in6_init(&ifra.ifra_prefixmask, &in6mask64, 0, 0, 0); /* link-local addresses should NEVER expire. */ ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; /* * Now call in6_update_ifa() to do a bunch of procedures to configure * a link-local address. We can set the 3rd argument to NULL, because * we know there's no other link-local address on the interface * and therefore we are adding one (instead of updating one). */ if ((error = in6_update_ifa(ifp, &ifra, IN6_IFAUPDATE_DADDELAY)) != 0) { /* * XXX: When the interface does not support IPv6, this call * would fail in the SIOCINITIFADDR ioctl. I believe the * notification is rather confusing in this case, so just * suppress it. (jinmei@kame.net 20010130) */ if (error != EAFNOSUPPORT) nd6log(LOG_NOTICE, "failed to configure a link-local address on %s " "(errno=%d)\n", if_name(ifp), error); return -1; } return 0; } /* * ifp - mut be IFT_LOOP */ static int in6_ifattach_loopback(struct ifnet *ifp) { struct in6_aliasreq ifra; int error; memset(&ifra, 0, sizeof(ifra)); /* * in6_update_ifa() does not use ifra_name, but we accurately set it * for safety. */ strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name)); sockaddr_in6_init(&ifra.ifra_prefixmask, &in6mask128, 0, 0, 0); /* * Always initialize ia_dstaddr (= broadcast address) to loopback * address. Follows IPv4 practice - see in_ifinit(). */ sockaddr_in6_init(&ifra.ifra_dstaddr, &in6addr_loopback, 0, 0, 0); sockaddr_in6_init(&ifra.ifra_addr, &in6addr_loopback, 0, 0, 0); /* 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, 0)) != 0) { nd6log(LOG_ERR, "failed to configure " "the loopback address on %s (errno=%d)\n", if_name(ifp), 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. */ memset(&ctxt, 0, sizeof(ctxt)); MD5Init(&ctxt); MD5Update(&ctxt, &l, sizeof(l)); MD5Update(&ctxt, n, l); MD5Final(digest, &ctxt); memset(sa6, 0, sizeof(*sa6)); sa6->sin6_family = AF_INET6; sa6->sin6_len = sizeof(*sa6); sa6->sin6_addr.s6_addr16[0] = htons(0xff02); sa6->sin6_addr.s6_addr8[11] = 2; memcpy(&sa6->sin6_addr.s6_addr32[3], digest, sizeof(sa6->sin6_addr.s6_addr32[3])); if (in6_setscope(&sa6->sin6_addr, ifp, NULL)) return -1; /* XXX: should not fail */ 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 * * altifp - secondary EUI64 source */ void in6_ifattach(struct ifnet *ifp, struct ifnet *altifp) { struct in6_ifaddr *ia; struct in6_addr in6; KASSERT(IFNET_LOCKED(ifp)); /* some of the interfaces are inherently not IPv6 capable */ switch (ifp->if_type) { case IFT_BRIDGE: case IFT_L2TP: case IFT_IEEE8023ADLAG: #ifdef IFT_PFLOG case IFT_PFLOG: #endif #ifdef IFT_PFSYNC case IFT_PFSYNC: #endif ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL; ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; return; } /* * if link mtu is too small, don't try to configure IPv6. * remember there could be some link-layer that has special * fragmentation logic. */ if (ifp->if_mtu < IPV6_MMTU) { nd6log(LOG_INFO, "%s has too small MTU, IPv6 not enabled\n", if_name(ifp)); return; } /* * quirks based on interface type */ switch (ifp->if_type) { #ifdef IFT_STF case IFT_STF: /* * 6to4 interface is a very special kind of beast. * no multicast, no linklocal. RFC2529 specifies how to make * linklocals for 6to4 interface, but there's no use and * it is rather harmful to have one. */ ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL; return; #endif case IFT_CARP: return; default: break; } /* * usually, we require multicast capability to the interface */ if ((ifp->if_flags & IFF_MULTICAST) == 0) { nd6log(LOG_INFO, "%s is not multicast capable, IPv6 not enabled\n", if_name(ifp)); return; } /* * assign loopback address for loopback interface. * XXX multiple loopback interface case. */ if ((ifp->if_flags & IFF_LOOPBACK) != 0) { in6 = in6addr_loopback; /* These are safe and atomic thanks to IFNET_LOCK */ if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) { if (in6_ifattach_loopback(ifp) != 0) return; } } /* * assign a link-local address, if there's none. */ if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) && ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) { int bound = curlwp_bind(); struct psref psref; ia = in6ifa_ifpforlinklocal_psref(ifp, 0, &psref); if (ia == NULL && in6_ifattach_linklocal(ifp, altifp) != 0) { printf("%s: cannot assign link-local address\n", ifp->if_xname); } ia6_release(ia, &psref); curlwp_bindx(bound); } } /* * NOTE: in6_ifdetach() does not support loopback if at this moment. * We don't need this function in bsdi, because interfaces are never removed * from the ifnet list in bsdi. */ void in6_ifdetach(struct ifnet *ifp) { /* nuke any of IPv6 addresses we have */ if_purgeaddrs(ifp, AF_INET6, in6_purgeaddr); in6_purge_multi(ifp); /* remove ip6_mrouter stuff */ ip6_mrouter_detach(ifp); /* remove neighbor management table */ nd6_purge(ifp, NULL); }