/* $NetBSD: icmp6.c,v 1.162 2013/06/05 19:01:26 christos Exp $ */ /* $KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 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. */ /* * Copyright (c) 1982, 1986, 1988, 1993 * The Regents of the University of California. 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 University 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 REGENTS 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 REGENTS 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. * * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 */ #include __KERNEL_RCSID(0, "$NetBSD: icmp6.c,v 1.162 2013/06/05 19:01:26 christos 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 #include #include #include #include #include #ifdef IPSEC #include #include #endif #include "faith.h" #if defined(NFAITH) && 0 < NFAITH #include #endif #include extern struct domain inet6domain; percpu_t *icmp6stat_percpu; extern struct inpcbtable raw6cbtable; extern int icmp6errppslim; static int icmp6errpps_count = 0; static struct timeval icmp6errppslim_last; extern int icmp6_nodeinfo; /* * List of callbacks to notify when Path MTU changes are made. */ struct icmp6_mtudisc_callback { LIST_ENTRY(icmp6_mtudisc_callback) mc_list; void (*mc_func)(struct in6_addr *); }; LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks = LIST_HEAD_INITIALIZER(&icmp6_mtudisc_callbacks); static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL; extern int pmtu_expire; /* XXX do these values make any sense? */ static int icmp6_mtudisc_hiwat = 1280; static int icmp6_mtudisc_lowat = 256; /* * keep track of # of redirect routes. */ static struct rttimer_queue *icmp6_redirect_timeout_q = NULL; /* XXX experimental, turned off */ static int icmp6_redirect_hiwat = -1; static int icmp6_redirect_lowat = -1; static void icmp6_errcount(u_int, int, int); static int icmp6_rip6_input(struct mbuf **, int); static int icmp6_ratelimit(const struct in6_addr *, const int, const int); static const char *icmp6_redirect_diag(struct in6_addr *, struct in6_addr *, struct in6_addr *); static struct mbuf *ni6_input(struct mbuf *, int); static struct mbuf *ni6_nametodns(const char *, int, int); static int ni6_dnsmatch(const char *, int, const char *, int); static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, struct ifnet **, char *); static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, struct ifnet *, int); static int icmp6_notify_error(struct mbuf *, int, int, int); static struct rtentry *icmp6_mtudisc_clone(struct sockaddr *); static void icmp6_mtudisc_timeout(struct rtentry *, struct rttimer *); static void icmp6_redirect_timeout(struct rtentry *, struct rttimer *); static void sysctl_net_inet6_icmp6_setup(struct sysctllog **); void icmp6_init(void) { sysctl_net_inet6_icmp6_setup(NULL); mld_init(); icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire); icmp6_redirect_timeout_q = rt_timer_queue_create(icmp6_redirtimeout); icmp6stat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP6_NSTATS); } static void icmp6_errcount(u_int base, int type, int code) { switch (type) { case ICMP6_DST_UNREACH: switch (code) { case ICMP6_DST_UNREACH_NOROUTE: ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_NOROUTE); return; case ICMP6_DST_UNREACH_ADMIN: ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_ADMIN); return; case ICMP6_DST_UNREACH_BEYONDSCOPE: ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_BEYONDSCOPE); return; case ICMP6_DST_UNREACH_ADDR: ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_ADDR); return; case ICMP6_DST_UNREACH_NOPORT: ICMP6_STATINC(base + ICMP6_ERRSTAT_DST_UNREACH_NOPORT); return; } break; case ICMP6_PACKET_TOO_BIG: ICMP6_STATINC(base + ICMP6_ERRSTAT_PACKET_TOO_BIG); return; case ICMP6_TIME_EXCEEDED: switch (code) { case ICMP6_TIME_EXCEED_TRANSIT: ICMP6_STATINC(base + ICMP6_ERRSTAT_TIME_EXCEED_TRANSIT); return; case ICMP6_TIME_EXCEED_REASSEMBLY: ICMP6_STATINC(base + ICMP6_ERRSTAT_TIME_EXCEED_REASSEMBLY); return; } break; case ICMP6_PARAM_PROB: switch (code) { case ICMP6_PARAMPROB_HEADER: ICMP6_STATINC(base + ICMP6_ERRSTAT_PARAMPROB_HEADER); return; case ICMP6_PARAMPROB_NEXTHEADER: ICMP6_STATINC(base + ICMP6_ERRSTAT_PARAMPROB_NEXTHEADER); return; case ICMP6_PARAMPROB_OPTION: ICMP6_STATINC(base + ICMP6_ERRSTAT_PARAMPROB_OPTION); return; } break; case ND_REDIRECT: ICMP6_STATINC(base + ICMP6_ERRSTAT_REDIRECT); return; } ICMP6_STATINC(base + ICMP6_ERRSTAT_UNKNOWN); } /* * Register a Path MTU Discovery callback. */ void icmp6_mtudisc_callback_register(void (*func)(struct in6_addr *)) { struct icmp6_mtudisc_callback *mc; for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL; mc = LIST_NEXT(mc, mc_list)) { if (mc->mc_func == func) return; } mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT); if (mc == NULL) panic("icmp6_mtudisc_callback_register"); mc->mc_func = func; LIST_INSERT_HEAD(&icmp6_mtudisc_callbacks, mc, mc_list); } /* * A wrapper function for icmp6_error() necessary when the erroneous packet * may not contain enough scope zone information. */ void icmp6_error2(struct mbuf *m, int type, int code, int param, struct ifnet *ifp) { struct ip6_hdr *ip6; if (ifp == NULL) return; if (m->m_len < sizeof(struct ip6_hdr)) { m = m_pullup(m, sizeof(struct ip6_hdr)); if (m == NULL) return; } ip6 = mtod(m, struct ip6_hdr *); if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) return; if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) return; icmp6_error(m, type, code, param); } /* * Generate an error packet of type error in response to bad IP6 packet. */ void icmp6_error(struct mbuf *m, int type, int code, int param) { struct ip6_hdr *oip6, *nip6; struct icmp6_hdr *icmp6; u_int preplen; int off; int nxt; ICMP6_STATINC(ICMP6_STAT_ERROR); /* count per-type-code statistics */ icmp6_errcount(ICMP6_STAT_OUTERRHIST, type, code); if (m->m_flags & M_DECRYPTED) { ICMP6_STATINC(ICMP6_STAT_CANTERROR); goto freeit; } if (M_UNWRITABLE(m, sizeof(struct ip6_hdr)) && (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) return; oip6 = mtod(m, struct ip6_hdr *); /* * If the destination address of the erroneous packet is a multicast * address, or the packet was sent using link-layer multicast, * we should basically suppress sending an error (RFC 2463, Section * 2.4). * We have two exceptions (the item e.2 in that section): * - the Pakcet Too Big message can be sent for path MTU discovery. * - the Parameter Problem Message that can be allowed an icmp6 error * in the option type field. This check has been done in * ip6_unknown_opt(), so we can just check the type and code. */ if ((m->m_flags & (M_BCAST|M_MCAST) || IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) && (type != ICMP6_PACKET_TOO_BIG && (type != ICMP6_PARAM_PROB || code != ICMP6_PARAMPROB_OPTION))) goto freeit; /* * RFC 2463, 2.4 (e.5): source address check. * XXX: the case of anycast source? */ if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) || IN6_IS_ADDR_MULTICAST(&oip6->ip6_src)) goto freeit; /* * If we are about to send ICMPv6 against ICMPv6 error/redirect, * don't do it. */ nxt = -1; off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt); if (off >= 0 && nxt == IPPROTO_ICMPV6) { struct icmp6_hdr *icp; IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, sizeof(*icp)); if (icp == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return; } if (icp->icmp6_type < ICMP6_ECHO_REQUEST || icp->icmp6_type == ND_REDIRECT) { /* * ICMPv6 error * Special case: for redirect (which is * informational) we must not send icmp6 error. */ ICMP6_STATINC(ICMP6_STAT_CANTERROR); goto freeit; } else { /* ICMPv6 informational - send the error */ } } #if 0 /* controversial */ else if (off >= 0 && nxt == IPPROTO_ESP) { /* * It could be ICMPv6 error inside ESP. Take a safer side, * don't respond. */ ICMP6_STATINC(ICMP6_STAT_CANTERROR); goto freeit; } #endif else { /* non-ICMPv6 - send the error */ } oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ /* Finally, do rate limitation check. */ if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { ICMP6_STATINC(ICMP6_STAT_TOOFREQ); goto freeit; } /* * OK, ICMP6 can be generated. */ if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN) m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len); preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); M_PREPEND(m, preplen, M_DONTWAIT); if (m && M_UNWRITABLE(m, preplen)) m = m_pullup(m, preplen); if (m == NULL) { nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); return; } nip6 = mtod(m, struct ip6_hdr *); nip6->ip6_src = oip6->ip6_src; nip6->ip6_dst = oip6->ip6_dst; in6_clearscope(&oip6->ip6_src); in6_clearscope(&oip6->ip6_dst); icmp6 = (struct icmp6_hdr *)(nip6 + 1); icmp6->icmp6_type = type; icmp6->icmp6_code = code; icmp6->icmp6_pptr = htonl((u_int32_t)param); /* * icmp6_reflect() is designed to be in the input path. * icmp6_error() can be called from both input and output path, * and if we are in output path rcvif could contain bogus value. * clear m->m_pkthdr.rcvif for safety, we should have enough scope * information in ip header (nip6). */ m->m_pkthdr.rcvif = NULL; ICMP6_STATINC(ICMP6_STAT_OUTHIST + type); icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ return; freeit: /* * If we can't tell whether or not we can generate ICMP6, free it. */ m_freem(m); } /* * Process a received ICMP6 message. */ int icmp6_input(struct mbuf **mp, int *offp, int proto) { struct mbuf *m = *mp, *n; struct ip6_hdr *ip6, *nip6; struct icmp6_hdr *icmp6, *nicmp6; int off = *offp; int icmp6len = m->m_pkthdr.len - *offp; int code, sum, noff, i; #define ICMP6_MAXLEN (sizeof(*nip6) + sizeof(*nicmp6) + 4) KASSERT(ICMP6_MAXLEN < MCLBYTES); icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg); /* * Locate icmp6 structure in mbuf, and check * that not corrupted and of at least minimum length */ if (icmp6len < sizeof(struct icmp6_hdr)) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); goto freeit; } i = off + sizeof(*icmp6); if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == 0) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); #if 0 /* m is 0 here */ icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); #endif goto freeit; } ip6 = mtod(m, struct ip6_hdr *); /* * calculate the checksum */ IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); if (icmp6 == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); /* m is invalid */ /*icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);*/ return IPPROTO_DONE; } KASSERT(IP6_HDR_ALIGNED_P(icmp6)); code = icmp6->icmp6_code; if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { nd6log((LOG_ERR, "ICMP6 checksum error(%d|%x) %s\n", icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src))); ICMP6_STATINC(ICMP6_STAT_CHECKSUM); icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); goto freeit; } #if defined(NFAITH) && 0 < NFAITH if (faithprefix(&ip6->ip6_dst)) { /* * Deliver very specific ICMP6 type only. * This is important to deliver TOOBIG. Otherwise PMTUD * will not work. */ switch (icmp6->icmp6_type) { case ICMP6_DST_UNREACH: case ICMP6_PACKET_TOO_BIG: case ICMP6_TIME_EXCEEDED: break; default: goto freeit; } } #endif ICMP6_STATINC(ICMP6_STAT_INHIST + icmp6->icmp6_type); switch (icmp6->icmp6_type) { case ICMP6_DST_UNREACH: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach); switch (code) { case ICMP6_DST_UNREACH_NOROUTE: code = PRC_UNREACH_NET; break; case ICMP6_DST_UNREACH_ADMIN: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib); code = PRC_UNREACH_PROTOCOL; /* is this a good code? */ break; case ICMP6_DST_UNREACH_ADDR: code = PRC_HOSTDEAD; break; #ifdef COMPAT_RFC1885 case ICMP6_DST_UNREACH_NOTNEIGHBOR: code = PRC_UNREACH_SRCFAIL; break; #else case ICMP6_DST_UNREACH_BEYONDSCOPE: /* I mean "source address was incorrect." */ code = PRC_UNREACH_NET; break; #endif case ICMP6_DST_UNREACH_NOPORT: code = PRC_UNREACH_PORT; break; default: goto badcode; } goto deliver; case ICMP6_PACKET_TOO_BIG: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig); /* * MTU is checked in icmp6_mtudisc. */ code = PRC_MSGSIZE; /* * Updating the path MTU will be done after examining * intermediate extension headers. */ goto deliver; case ICMP6_TIME_EXCEEDED: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed); switch (code) { case ICMP6_TIME_EXCEED_TRANSIT: code = PRC_TIMXCEED_INTRANS; break; case ICMP6_TIME_EXCEED_REASSEMBLY: code = PRC_TIMXCEED_REASS; break; default: goto badcode; } goto deliver; case ICMP6_PARAM_PROB: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob); switch (code) { case ICMP6_PARAMPROB_NEXTHEADER: code = PRC_UNREACH_PROTOCOL; break; case ICMP6_PARAMPROB_HEADER: case ICMP6_PARAMPROB_OPTION: code = PRC_PARAMPROB; break; default: goto badcode; } goto deliver; case ICMP6_ECHO_REQUEST: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo); if (code != 0) goto badcode; /* * Copy mbuf to send to two data paths: userland socket(s), * and to the querier (echo reply). * m: a copy for socket, n: a copy for querier * * If the first mbuf is shared, or the first mbuf is too short, * copy the first part of the data into a fresh mbuf. * Otherwise, we will wrongly overwrite both copies. */ if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { /* Give up local */ n = m; m = NULL; } else if (M_READONLY(n) || n->m_len < off + sizeof(struct icmp6_hdr)) { struct mbuf *n0 = n; /* * Prepare an internal mbuf. m_pullup() doesn't * always copy the length we specified. */ if ((n = m_dup(n0, 0, M_COPYALL, M_DONTWAIT)) == NULL) { /* Give up local */ n = m; m = NULL; } m_freem(n0); } IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, sizeof(*nicmp6)); nicmp6->icmp6_type = ICMP6_ECHO_REPLY; nicmp6->icmp6_code = 0; if (n) { uint64_t *icmp6s = ICMP6_STAT_GETREF(); icmp6s[ICMP6_STAT_REFLECT]++; icmp6s[ICMP6_STAT_OUTHIST + ICMP6_ECHO_REPLY]++; ICMP6_STAT_PUTREF(); icmp6_reflect(n, off); } if (!m) goto freeit; break; case ICMP6_ECHO_REPLY: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply); if (code != 0) goto badcode; break; case MLD_LISTENER_QUERY: case MLD_LISTENER_REPORT: if (icmp6len < sizeof(struct mld_hdr)) goto badlen; if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */ icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery); else icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport); if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { /* give up local */ mld_input(m, off); m = NULL; goto freeit; } mld_input(n, off); /* m stays. */ break; case MLD_LISTENER_DONE: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone); if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */ goto badlen; break; /* nothing to be done in kernel */ case MLD_MTRACE_RESP: case MLD_MTRACE: /* XXX: these two are experimental. not officially defined. */ /* XXX: per-interface statistics? */ break; /* just pass it to applications */ case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ { enum { WRU, FQDN } mode; if (!icmp6_nodeinfo) break; if (icmp6len == sizeof(struct icmp6_hdr) + 4) mode = WRU; else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) mode = FQDN; else goto badlen; if (mode == FQDN) { n = m_copym(m, 0, M_COPYALL, M_DONTWAIT); if (n) n = ni6_input(n, off); /* XXX meaningless if n == NULL */ noff = sizeof(struct ip6_hdr); } else { u_char *p; int maxhlen; if ((icmp6_nodeinfo & 5) != 5) break; if (code != 0) goto badcode; MGETHDR(n, M_DONTWAIT, m->m_type); if (n && ICMP6_MAXLEN > MHLEN) { MCLGET(n, M_DONTWAIT); if ((n->m_flags & M_EXT) == 0) { m_free(n); n = NULL; } } if (n == NULL) { /* Give up remote */ break; } n->m_pkthdr.rcvif = NULL; n->m_len = 0; maxhlen = M_TRAILINGSPACE(n) - ICMP6_MAXLEN; if (maxhlen > hostnamelen) maxhlen = hostnamelen; /* * Copy IPv6 and ICMPv6 only. */ nip6 = mtod(n, struct ip6_hdr *); bcopy(ip6, nip6, sizeof(struct ip6_hdr)); nicmp6 = (struct icmp6_hdr *)(nip6 + 1); bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr)); p = (u_char *)(nicmp6 + 1); memset(p, 0, 4); bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */ noff = sizeof(struct ip6_hdr); M_COPY_PKTHDR(n, m); /* just for rcvif */ n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + 4 + maxhlen; nicmp6->icmp6_type = ICMP6_WRUREPLY; nicmp6->icmp6_code = 0; } #undef hostnamelen if (n) { uint64_t *icmp6s = ICMP6_STAT_GETREF(); icmp6s[ICMP6_STAT_REFLECT]++; icmp6s[ICMP6_STAT_OUTHIST + ICMP6_WRUREPLY]++; ICMP6_STAT_PUTREF(); icmp6_reflect(n, noff); } break; } case ICMP6_WRUREPLY: if (code != 0) goto badcode; break; case ND_ROUTER_SOLICIT: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_router_solicit)) goto badlen; if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { /* give up local */ nd6_rs_input(m, off, icmp6len); m = NULL; goto freeit; } nd6_rs_input(n, off, icmp6len); /* m stays. */ break; case ND_ROUTER_ADVERT: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_router_advert)) goto badlen; if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { /* give up local */ nd6_ra_input(m, off, icmp6len); m = NULL; goto freeit; } nd6_ra_input(n, off, icmp6len); /* m stays. */ break; case ND_NEIGHBOR_SOLICIT: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_neighbor_solicit)) goto badlen; if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { /* give up local */ nd6_ns_input(m, off, icmp6len); m = NULL; goto freeit; } nd6_ns_input(n, off, icmp6len); /* m stays. */ break; case ND_NEIGHBOR_ADVERT: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_neighbor_advert)) goto badlen; if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { /* give up local */ nd6_na_input(m, off, icmp6len); m = NULL; goto freeit; } nd6_na_input(n, off, icmp6len); /* m stays. */ break; case ND_REDIRECT: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_redirect)) goto badlen; if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { /* give up local */ icmp6_redirect_input(m, off); m = NULL; goto freeit; } icmp6_redirect_input(n, off); /* m stays. */ break; case ICMP6_ROUTER_RENUMBERING: if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && code != ICMP6_ROUTER_RENUMBERING_RESULT) goto badcode; if (icmp6len < sizeof(struct icmp6_router_renum)) goto badlen; break; default: nd6log((LOG_DEBUG, "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst), m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0)); if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { /* ICMPv6 error: MUST deliver it by spec... */ code = PRC_NCMDS; /* deliver */ } else { /* ICMPv6 informational: MUST not deliver */ break; } deliver: if (icmp6_notify_error(m, off, icmp6len, code)) { /* In this case, m should've been freed. */ return (IPPROTO_DONE); } break; badcode: ICMP6_STATINC(ICMP6_STAT_BADCODE); break; badlen: ICMP6_STATINC(ICMP6_STAT_BADLEN); break; } /* deliver the packet to appropriate sockets */ icmp6_rip6_input(&m, *offp); return IPPROTO_DONE; freeit: m_freem(m); return IPPROTO_DONE; } static int icmp6_notify_error(struct mbuf *m, int off, int icmp6len, int code) { struct icmp6_hdr *icmp6; struct ip6_hdr *eip6; u_int32_t notifymtu; struct sockaddr_in6 icmp6src, icmp6dst; if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); goto freeit; } IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6) + sizeof(struct ip6_hdr)); if (icmp6 == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return (-1); } eip6 = (struct ip6_hdr *)(icmp6 + 1); /* Detect the upper level protocol */ { void (*ctlfunc)(int, struct sockaddr *, void *); u_int8_t nxt = eip6->ip6_nxt; int eoff = off + sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr); struct ip6ctlparam ip6cp; struct in6_addr *finaldst = NULL; int icmp6type = icmp6->icmp6_type; struct ip6_frag *fh; struct ip6_rthdr *rth; struct ip6_rthdr0 *rth0; int rthlen; while (1) { /* XXX: should avoid infinite loop explicitly? */ struct ip6_ext *eh; switch (nxt) { case IPPROTO_HOPOPTS: case IPPROTO_DSTOPTS: case IPPROTO_AH: IP6_EXTHDR_GET(eh, struct ip6_ext *, m, eoff, sizeof(*eh)); if (eh == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return (-1); } if (nxt == IPPROTO_AH) eoff += (eh->ip6e_len + 2) << 2; else eoff += (eh->ip6e_len + 1) << 3; nxt = eh->ip6e_nxt; break; case IPPROTO_ROUTING: /* * When the erroneous packet contains a * routing header, we should examine the * header to determine the final destination. * Otherwise, we can't properly update * information that depends on the final * destination (e.g. path MTU). */ IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, eoff, sizeof(*rth)); if (rth == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return (-1); } rthlen = (rth->ip6r_len + 1) << 3; /* * XXX: currently there is no * officially defined type other * than type-0. * Note that if the segment left field * is 0, all intermediate hops must * have been passed. */ if (rth->ip6r_segleft && rth->ip6r_type == IPV6_RTHDR_TYPE_0) { int hops; IP6_EXTHDR_GET(rth0, struct ip6_rthdr0 *, m, eoff, rthlen); if (rth0 == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return (-1); } /* just ignore a bogus header */ if ((rth0->ip6r0_len % 2) == 0 && (hops = rth0->ip6r0_len/2)) finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1); } eoff += rthlen; nxt = rth->ip6r_nxt; break; case IPPROTO_FRAGMENT: IP6_EXTHDR_GET(fh, struct ip6_frag *, m, eoff, sizeof(*fh)); if (fh == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return (-1); } /* * Data after a fragment header is meaningless * unless it is the first fragment, but * we'll go to the notify label for path MTU * discovery. */ if (fh->ip6f_offlg & IP6F_OFF_MASK) goto notify; eoff += sizeof(struct ip6_frag); nxt = fh->ip6f_nxt; break; default: /* * This case includes ESP and the No Next * Header. In such cases going to the notify * label does not have any meaning * (i.e. ctlfunc will be NULL), but we go * anyway since we might have to update * path MTU information. */ goto notify; } } notify: IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6) + sizeof(struct ip6_hdr)); if (icmp6 == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return (-1); } /* * retrieve parameters from the inner IPv6 header, and convert * them into sockaddr structures. * XXX: there is no guarantee that the source or destination * addresses of the inner packet are in the same scope zone as * the addresses of the icmp packet. But there is no other * way to determine the zone. */ eip6 = (struct ip6_hdr *)(icmp6 + 1); sockaddr_in6_init(&icmp6dst, (finaldst == NULL) ? &eip6->ip6_dst : finaldst, 0, 0, 0); if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) goto freeit; sockaddr_in6_init(&icmp6src, &eip6->ip6_src, 0, 0, 0); if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) goto freeit; icmp6src.sin6_flowinfo = (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); if (finaldst == NULL) finaldst = &eip6->ip6_dst; ip6cp.ip6c_m = m; ip6cp.ip6c_icmp6 = icmp6; ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); ip6cp.ip6c_off = eoff; ip6cp.ip6c_finaldst = finaldst; ip6cp.ip6c_src = &icmp6src; ip6cp.ip6c_nxt = nxt; if (icmp6type == ICMP6_PACKET_TOO_BIG) { notifymtu = ntohl(icmp6->icmp6_mtu); ip6cp.ip6c_cmdarg = (void *)¬ifymtu; } ctlfunc = (void (*)(int, struct sockaddr *, void *)) (inet6sw[ip6_protox[nxt]].pr_ctlinput); if (ctlfunc) { (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst, &ip6cp); } } return (0); freeit: m_freem(m); return (-1); } void icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) { unsigned long rtcount; struct icmp6_mtudisc_callback *mc; struct in6_addr *dst = ip6cp->ip6c_finaldst; struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */ u_int mtu = ntohl(icmp6->icmp6_mtu); struct rtentry *rt = NULL; struct sockaddr_in6 sin6; /* * The MTU should not be less than the minimal IPv6 MTU except for the * hack in ip6_output/ip6_setpmtu where we always include a frag header. * In that one case, the MTU might be less than 1280. */ if (__predict_false(mtu < IPV6_MMTU - sizeof(struct ip6_frag))) { /* is the mtu even sane? */ if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) return; if (!validated) return; mtu = IPV6_MMTU - sizeof(struct ip6_frag); } /* * allow non-validated cases if memory is plenty, to make traffic * from non-connected pcb happy. */ rtcount = rt_timer_count(icmp6_mtudisc_timeout_q); if (validated) { if (0 <= icmp6_mtudisc_hiwat && rtcount > icmp6_mtudisc_hiwat) return; else if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat) { /* * XXX nuke a victim, install the new one. */ } } else { if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat) return; } memset(&sin6, 0, sizeof(sin6)); sin6.sin6_family = PF_INET6; sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_addr = *dst; if (in6_setscope(&sin6.sin6_addr, m->m_pkthdr.rcvif, NULL)) return; rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6); if (rt && (rt->rt_flags & RTF_HOST) && !(rt->rt_rmx.rmx_locks & RTV_MTU) && (rt->rt_rmx.rmx_mtu > mtu || rt->rt_rmx.rmx_mtu == 0)) { if (mtu < IN6_LINKMTU(rt->rt_ifp)) { ICMP6_STATINC(ICMP6_STAT_PMTUCHG); rt->rt_rmx.rmx_mtu = mtu; } } if (rt) { /* XXX: need braces to avoid conflict with else in RTFREE. */ RTFREE(rt); } /* * Notify protocols that the MTU for this destination * has changed. */ for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL; mc = LIST_NEXT(mc, mc_list)) (*mc->mc_func)(&sin6.sin6_addr); } /* * Process a Node Information Query packet, based on * draft-ietf-ipngwg-icmp-name-lookups-07. * * Spec incompatibilities: * - IPv6 Subject address handling * - IPv4 Subject address handling support missing * - Proxy reply (answer even if it's not for me) * - joins NI group address at in6_ifattach() time only, does not cope * with hostname changes by sethostname(3) */ static struct mbuf * ni6_input(struct mbuf *m, int off) { struct icmp6_nodeinfo *ni6, *nni6; struct mbuf *n = NULL; u_int16_t qtype; int subjlen; int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); struct ni_reply_fqdn *fqdn; int addrs; /* for NI_QTYPE_NODEADDR */ struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ struct sockaddr_in6 sin6; /* ip6_dst */ struct in6_addr in6_subj; /* subject address */ struct ip6_hdr *ip6; int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ char *subj = NULL; ip6 = mtod(m, struct ip6_hdr *); IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); if (ni6 == NULL) { /* m is already reclaimed */ return NULL; } /* * Validate IPv6 destination address. * * The Responder must discard the Query without further processing * unless it is one of the Responder's unicast or anycast addresses, or * a link-local scope multicast address which the Responder has joined. * [icmp-name-lookups-07, Section 4.] */ sockaddr_in6_init(&sin6, &ip6->ip6_dst, 0, 0, 0); /* XXX scopeid */ if (ifa_ifwithaddr((struct sockaddr *)&sin6)) ; /* unicast/anycast, fine */ else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr)) ; /* link-local multicast, fine */ else goto bad; /* validate query Subject field. */ qtype = ntohs(ni6->ni_qtype); subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); switch (qtype) { case NI_QTYPE_NOOP: case NI_QTYPE_SUPTYPES: /* 07 draft */ if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) break; /* FALLTHROUGH */ case NI_QTYPE_FQDN: case NI_QTYPE_NODEADDR: case NI_QTYPE_IPV4ADDR: switch (ni6->ni_code) { case ICMP6_NI_SUBJ_IPV6: #if ICMP6_NI_SUBJ_IPV6 != 0 case 0: #endif /* * backward compatibility - try to accept 03 draft * format, where no Subject is present. */ if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && subjlen == 0) { oldfqdn++; break; } #if ICMP6_NI_SUBJ_IPV6 != 0 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) goto bad; #endif if (subjlen != sizeof(sin6.sin6_addr)) goto bad; /* * Validate Subject address. * * Not sure what exactly "address belongs to the node" * means in the spec, is it just unicast, or what? * * At this moment we consider Subject address as * "belong to the node" if the Subject address equals * to the IPv6 destination address; validation for * IPv6 destination address should have done enough * check for us. * * We do not do proxy at this moment. */ /* m_pulldown instead of copy? */ m_copydata(m, off + sizeof(struct icmp6_nodeinfo), subjlen, (void *)&in6_subj); if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) goto bad; subj = (char *)&in6_subj; if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) break; /* * XXX if we are to allow other cases, we should really * be careful about scope here. * basically, we should disallow queries toward IPv6 * destination X with subject Y, if scope(X) > scope(Y). * if we allow scope(X) > scope(Y), it will result in * information leakage across scope boundary. */ goto bad; case ICMP6_NI_SUBJ_FQDN: /* * Validate Subject name with gethostname(3). * * The behavior may need some debate, since: * - we are not sure if the node has FQDN as * hostname (returned by gethostname(3)). * - the code does wildcard match for truncated names. * however, we are not sure if we want to perform * wildcard match, if gethostname(3) side has * truncated hostname. */ n = ni6_nametodns(hostname, hostnamelen, 0); if (!n || n->m_next || n->m_len == 0) goto bad; IP6_EXTHDR_GET(subj, char *, m, off + sizeof(struct icmp6_nodeinfo), subjlen); if (subj == NULL) goto bad; if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), n->m_len)) { goto bad; } m_freem(n); n = NULL; break; case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ default: goto bad; } break; } /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ switch (qtype) { case NI_QTYPE_FQDN: if ((icmp6_nodeinfo & 1) == 0) goto bad; break; case NI_QTYPE_NODEADDR: case NI_QTYPE_IPV4ADDR: if ((icmp6_nodeinfo & 2) == 0) goto bad; break; } /* guess reply length */ switch (qtype) { case NI_QTYPE_NOOP: break; /* no reply data */ case NI_QTYPE_SUPTYPES: replylen += sizeof(u_int32_t); break; case NI_QTYPE_FQDN: /* XXX will append an mbuf */ replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); break; case NI_QTYPE_NODEADDR: addrs = ni6_addrs(ni6, m, &ifp, subj); if ((replylen += addrs * (sizeof(struct in6_addr) + sizeof(u_int32_t))) > MCLBYTES) replylen = MCLBYTES; /* XXX: will truncate pkt later */ break; case NI_QTYPE_IPV4ADDR: /* unsupported - should respond with unknown Qtype? */ goto bad; default: /* * XXX: We must return a reply with the ICMP6 code * `unknown Qtype' in this case. However we regard the case * as an FQDN query for backward compatibility. * Older versions set a random value to this field, * so it rarely varies in the defined qtypes. * But the mechanism is not reliable... * maybe we should obsolete older versions. */ qtype = NI_QTYPE_FQDN; /* XXX will append an mbuf */ replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); oldfqdn++; break; } /* allocate an mbuf to reply. */ MGETHDR(n, M_DONTWAIT, m->m_type); if (n == NULL) { m_freem(m); return (NULL); } M_MOVE_PKTHDR(n, m); /* just for rcvif */ if (replylen > MHLEN) { if (replylen > MCLBYTES) { /* * XXX: should we try to allocate more? But MCLBYTES * is probably much larger than IPV6_MMTU... */ goto bad; } MCLGET(n, M_DONTWAIT); if ((n->m_flags & M_EXT) == 0) { goto bad; } } n->m_pkthdr.len = n->m_len = replylen; /* copy mbuf header and IPv6 + Node Information base headers */ bcopy(mtod(m, void *), mtod(n, void *), sizeof(struct ip6_hdr)); nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); bcopy((void *)ni6, (void *)nni6, sizeof(struct icmp6_nodeinfo)); /* qtype dependent procedure */ switch (qtype) { case NI_QTYPE_NOOP: nni6->ni_code = ICMP6_NI_SUCCESS; nni6->ni_flags = 0; break; case NI_QTYPE_SUPTYPES: { u_int32_t v; nni6->ni_code = ICMP6_NI_SUCCESS; nni6->ni_flags = htons(0x0000); /* raw bitmap */ /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ v = (u_int32_t)htonl(0x0000000f); bcopy(&v, nni6 + 1, sizeof(u_int32_t)); break; } case NI_QTYPE_FQDN: nni6->ni_code = ICMP6_NI_SUCCESS; fqdn = (struct ni_reply_fqdn *)(mtod(n, char *) + sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); nni6->ni_flags = 0; /* XXX: meaningless TTL */ fqdn->ni_fqdn_ttl = 0; /* ditto. */ /* * XXX do we really have FQDN in variable "hostname"? */ n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn); if (n->m_next == NULL) goto bad; /* XXX we assume that n->m_next is not a chain */ if (n->m_next->m_next != NULL) goto bad; n->m_pkthdr.len += n->m_next->m_len; break; case NI_QTYPE_NODEADDR: { int lenlim, copied; nni6->ni_code = ICMP6_NI_SUCCESS; n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); lenlim = M_TRAILINGSPACE(n); copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); /* XXX: reset mbuf length */ n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo) + copied; break; } default: break; /* XXX impossible! */ } nni6->ni_type = ICMP6_NI_REPLY; m_freem(m); return (n); bad: m_freem(m); if (n) m_freem(n); return (NULL); } #undef hostnamelen #define isupper(x) ('A' <= (x) && (x) <= 'Z') #define isalpha(x) (('A' <= (x) && (x) <= 'Z') || ('a' <= (x) && (x) <= 'z')) #define isalnum(x) (isalpha(x) || ('0' <= (x) && (x) <= '9')) #define tolower(x) (isupper(x) ? (x) + 'a' - 'A' : (x)) /* * make a mbuf with DNS-encoded string. no compression support. * * XXX names with less than 2 dots (like "foo" or "foo.section") will be * treated as truncated name (two \0 at the end). this is a wild guess. * * old - return pascal string if non-zero */ static struct mbuf * ni6_nametodns(const char *name, int namelen, int old) { struct mbuf *m; char *cp, *ep; const char *p, *q; int i, len, nterm; if (old) len = namelen + 1; else len = MCLBYTES; /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */ MGET(m, M_DONTWAIT, MT_DATA); if (m && len > MLEN) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) goto fail; } if (!m) goto fail; m->m_next = NULL; if (old) { m->m_len = len; *mtod(m, char *) = namelen; bcopy(name, mtod(m, char *) + 1, namelen); return m; } else { m->m_len = 0; cp = mtod(m, char *); ep = mtod(m, char *) + M_TRAILINGSPACE(m); /* if not certain about my name, return empty buffer */ if (namelen == 0) return m; /* * guess if it looks like shortened hostname, or FQDN. * shortened hostname needs two trailing "\0". */ i = 0; for (p = name; p < name + namelen; p++) { if (*p && *p == '.') i++; } if (i < 2) nterm = 2; else nterm = 1; p = name; while (cp < ep && p < name + namelen) { i = 0; for (q = p; q < name + namelen && *q && *q != '.'; q++) i++; /* result does not fit into mbuf */ if (cp + i + 1 >= ep) goto fail; /* * DNS label length restriction, RFC1035 page 8. * "i == 0" case is included here to avoid returning * 0-length label on "foo..bar". */ if (i <= 0 || i >= 64) goto fail; *cp++ = i; if (!isalpha(p[0]) || !isalnum(p[i - 1])) goto fail; while (i > 0) { if (!isalnum(*p) && *p != '-') goto fail; if (isupper(*p)) { *cp++ = tolower(*p); p++; } else *cp++ = *p++; i--; } p = q; if (p < name + namelen && *p == '.') p++; } /* termination */ if (cp + nterm >= ep) goto fail; while (nterm-- > 0) *cp++ = '\0'; m->m_len = cp - mtod(m, char *); return m; } panic("should not reach here"); /* NOTREACHED */ fail: if (m) m_freem(m); return NULL; } /* * check if two DNS-encoded string matches. takes care of truncated * form (with \0\0 at the end). no compression support. * XXX upper/lowercase match (see RFC2065) */ static int ni6_dnsmatch(const char *a, int alen, const char *b, int blen) { const char *a0, *b0; int l; /* simplest case - need validation? */ if (alen == blen && memcmp(a, b, alen) == 0) return 1; a0 = a; b0 = b; /* termination is mandatory */ if (alen < 2 || blen < 2) return 0; if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') return 0; alen--; blen--; while (a - a0 < alen && b - b0 < blen) { if (a - a0 + 1 > alen || b - b0 + 1 > blen) return 0; if ((signed char)a[0] < 0 || (signed char)b[0] < 0) return 0; /* we don't support compression yet */ if (a[0] >= 64 || b[0] >= 64) return 0; /* truncated case */ if (a[0] == 0 && a - a0 == alen - 1) return 1; if (b[0] == 0 && b - b0 == blen - 1) return 1; if (a[0] == 0 || b[0] == 0) return 0; if (a[0] != b[0]) return 0; l = a[0]; if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) return 0; if (memcmp(a + 1, b + 1, l) != 0) return 0; a += 1 + l; b += 1 + l; } if (a - a0 == alen && b - b0 == blen) return 1; else return 0; } /* * calculate the number of addresses to be returned in the node info reply. */ static int ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, char *subj) { struct ifnet *ifp; struct in6_ifaddr *ifa6; struct ifaddr *ifa; struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */ int addrs = 0, addrsofif, iffound = 0; int niflags = ni6->ni_flags; if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { switch (ni6->ni_code) { case ICMP6_NI_SUBJ_IPV6: if (subj == NULL) /* must be impossible... */ return (0); subj_ip6 = (struct sockaddr_in6 *)subj; break; default: /* * XXX: we only support IPv6 subject address for * this Qtype. */ return (0); } } IFNET_FOREACH(ifp) { addrsofif = 0; IFADDR_FOREACH(ifa, ifp) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ifa6 = (struct in6_ifaddr *)ifa; if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr, &ifa6->ia_addr.sin6_addr)) iffound = 1; /* * IPv4-mapped addresses can only be returned by a * Node Information proxy, since they represent * addresses of IPv4-only nodes, which perforce do * not implement this protocol. * [icmp-name-lookups-07, Section 5.4] * So we don't support NI_NODEADDR_FLAG_COMPAT in * this function at this moment. */ /* What do we have to do about ::1? */ switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { case IPV6_ADDR_SCOPE_LINKLOCAL: if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) continue; break; case IPV6_ADDR_SCOPE_SITELOCAL: if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) continue; break; case IPV6_ADDR_SCOPE_GLOBAL: if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) continue; break; default: continue; } /* * check if anycast is okay. * XXX: just experimental. not in the spec. */ if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) continue; /* we need only unicast addresses */ addrsofif++; /* count the address */ } if (iffound) { *ifpp = ifp; return (addrsofif); } addrs += addrsofif; } return (addrs); } static int ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, struct ifnet *ifp0, int resid) { struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet); struct in6_ifaddr *ifa6; struct ifaddr *ifa; struct ifnet *ifp_dep = NULL; int copied = 0, allow_deprecated = 0; u_char *cp = (u_char *)(nni6 + 1); int niflags = ni6->ni_flags; u_int32_t ltime; if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) return (0); /* needless to copy */ again: for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { IFADDR_FOREACH(ifa, ifp) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ifa6 = (struct in6_ifaddr *)ifa; if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && allow_deprecated == 0) { /* * prefererred address should be put before * deprecated addresses. */ /* record the interface for later search */ if (ifp_dep == NULL) ifp_dep = ifp; continue; } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && allow_deprecated != 0) continue; /* we now collect deprecated addrs */ /* What do we have to do about ::1? */ switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { case IPV6_ADDR_SCOPE_LINKLOCAL: if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) continue; break; case IPV6_ADDR_SCOPE_SITELOCAL: if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) continue; break; case IPV6_ADDR_SCOPE_GLOBAL: if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) continue; break; default: continue; } /* * check if anycast is okay. * XXX: just experimental. not in the spec. */ if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) continue; /* now we can copy the address */ if (resid < sizeof(struct in6_addr) + sizeof(u_int32_t)) { /* * We give up much more copy. * Set the truncate flag and return. */ nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; return (copied); } /* * Set the TTL of the address. * The TTL value should be one of the following * according to the specification: * * 1. The remaining lifetime of a DHCP lease on the * address, or * 2. The remaining Valid Lifetime of a prefix from * which the address was derived through Stateless * Autoconfiguration. * * Note that we currently do not support stateful * address configuration by DHCPv6, so the former * case can't happen. * * TTL must be 2^31 > TTL >= 0. */ if (ifa6->ia6_lifetime.ia6t_expire == 0) ltime = ND6_INFINITE_LIFETIME; else { if (ifa6->ia6_lifetime.ia6t_expire > time_second) ltime = ifa6->ia6_lifetime.ia6t_expire - time_second; else ltime = 0; } if (ltime > 0x7fffffff) ltime = 0x7fffffff; ltime = htonl(ltime); bcopy(<ime, cp, sizeof(u_int32_t)); cp += sizeof(u_int32_t); /* copy the address itself */ bcopy(&ifa6->ia_addr.sin6_addr, cp, sizeof(struct in6_addr)); in6_clearscope((struct in6_addr *)cp); /* XXX */ cp += sizeof(struct in6_addr); resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); } if (ifp0) /* we need search only on the specified IF */ break; } if (allow_deprecated == 0 && ifp_dep != NULL) { ifp = ifp_dep; allow_deprecated = 1; goto again; } return (copied); } /* * XXX almost dup'ed code with rip6_input. */ static int icmp6_rip6_input(struct mbuf **mp, int off) { struct mbuf *m = *mp; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct inpcb_hdr *inph; struct in6pcb *in6p; struct in6pcb *last = NULL; struct sockaddr_in6 rip6src; struct icmp6_hdr *icmp6; struct mbuf *opts = NULL; IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); if (icmp6 == NULL) { /* m is already reclaimed */ return IPPROTO_DONE; } /* * XXX: the address may have embedded scope zone ID, which should be * hidden from applications. */ sockaddr_in6_init(&rip6src, &ip6->ip6_src, 0, 0, 0); if (sa6_recoverscope(&rip6src)) { m_freem(m); return (IPPROTO_DONE); } CIRCLEQ_FOREACH(inph, &raw6cbtable.inpt_queue, inph_queue) { in6p = (struct in6pcb *)inph; if (in6p->in6p_af != AF_INET6) continue; if (in6p->in6p_ip6.ip6_nxt != IPPROTO_ICMPV6) continue; if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) && !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) continue; if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) && !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) continue; if (in6p->in6p_icmp6filt && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, in6p->in6p_icmp6filt)) continue; if (last) { struct mbuf *n; if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) { if (last->in6p_flags & IN6P_CONTROLOPTS) ip6_savecontrol(last, &opts, ip6, n); /* strip intermediate headers */ m_adj(n, off); if (sbappendaddr(&last->in6p_socket->so_rcv, (struct sockaddr *)&rip6src, n, opts) == 0) { /* should notify about lost packet */ m_freem(n); if (opts) m_freem(opts); } else sorwakeup(last->in6p_socket); opts = NULL; } } last = in6p; } if (last) { if (last->in6p_flags & IN6P_CONTROLOPTS) ip6_savecontrol(last, &opts, ip6, m); /* strip intermediate headers */ m_adj(m, off); if (sbappendaddr(&last->in6p_socket->so_rcv, (struct sockaddr *)&rip6src, m, opts) == 0) { m_freem(m); if (opts) m_freem(opts); } else sorwakeup(last->in6p_socket); } else { m_freem(m); IP6_STATDEC(IP6_STAT_DELIVERED); } return IPPROTO_DONE; } /* * Reflect the ip6 packet back to the source. * OFF points to the icmp6 header, counted from the top of the mbuf. * * Note: RFC 1885 required that an echo reply should be truncated if it * did not fit in with (return) path MTU, and KAME code supported the * behavior. However, as a clarification after the RFC, this limitation * was removed in a revised version of the spec, RFC 2463. We had kept the * old behavior, with a (non-default) ifdef block, while the new version of * the spec was an internet-draft status, and even after the new RFC was * published. But it would rather make sense to clean the obsoleted part * up, and to make the code simpler at this stage. */ void icmp6_reflect(struct mbuf *m, size_t off) { struct ip6_hdr *ip6; struct icmp6_hdr *icmp6; const struct in6_ifaddr *ia; const struct ip6aux *ip6a; int plen; int type, code; struct ifnet *outif = NULL; struct in6_addr origdst; const struct in6_addr *src = NULL; /* too short to reflect */ if (off < sizeof(struct ip6_hdr)) { nd6log((LOG_DEBUG, "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n", (u_long)off, (u_long)sizeof(struct ip6_hdr), __FILE__, __LINE__)); goto bad; } /* * If there are extra headers between IPv6 and ICMPv6, strip * off that header first. */ #ifdef DIAGNOSTIC if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN) panic("assumption failed in icmp6_reflect"); #endif if (off > sizeof(struct ip6_hdr)) { size_t l; struct ip6_hdr nip6; l = off - sizeof(struct ip6_hdr); m_copydata(m, 0, sizeof(nip6), (void *)&nip6); m_adj(m, l); l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); if (m->m_len < l) { if ((m = m_pullup(m, l)) == NULL) return; } bcopy((void *)&nip6, mtod(m, void *), sizeof(nip6)); } else /* off == sizeof(struct ip6_hdr) */ { size_t l; l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr); if (m->m_len < l) { if ((m = m_pullup(m, l)) == NULL) return; } } plen = m->m_pkthdr.len - sizeof(struct ip6_hdr); ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_nxt = IPPROTO_ICMPV6; icmp6 = (struct icmp6_hdr *)(ip6 + 1); type = icmp6->icmp6_type; /* keep type for statistics */ code = icmp6->icmp6_code; /* ditto. */ origdst = ip6->ip6_dst; /* * ip6_input() drops a packet if its src is multicast. * So, the src is never multicast. */ ip6->ip6_dst = ip6->ip6_src; /* * If the incoming packet was addressed directly to us (i.e. unicast), * use dst as the src for the reply. * The IN6_IFF_NOTREADY case should be VERY rare, but is possible * (for example) when we encounter an error while forwarding procedure * destined to a duplicated address of ours. * Note that ip6_getdstifaddr() may fail if we are in an error handling * procedure of an outgoing packet of our own, in which case we need * to search in the ifaddr list. */ if (IN6_IS_ADDR_MULTICAST(&origdst)) ; else if ((ip6a = ip6_getdstifaddr(m)) != NULL) { if ((ip6a->ip6a_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) src = &ip6a->ip6a_src; } else { union { struct sockaddr_in6 sin6; struct sockaddr sa; } u; sockaddr_in6_init(&u.sin6, &origdst, 0, 0, 0); ia = (struct in6_ifaddr *)ifa_ifwithaddr(&u.sa); if (ia == NULL) ; else if ((ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) src = &ia->ia_addr.sin6_addr; } if (src == NULL) { int e; struct sockaddr_in6 sin6; struct route ro; /* * This case matches to multicasts, our anycast, or unicasts * that we do not own. Select a source address based on the * source address of the erroneous packet. */ /* zone ID should be embedded */ sockaddr_in6_init(&sin6, &ip6->ip6_dst, 0, 0, 0); memset(&ro, 0, sizeof(ro)); src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e); rtcache_free(&ro); if (src == NULL) { nd6log((LOG_DEBUG, "icmp6_reflect: source can't be determined: " "dst=%s, error=%d\n", ip6_sprintf(&sin6.sin6_addr), e)); goto bad; } } ip6->ip6_src = *src; ip6->ip6_flow = 0; ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; ip6->ip6_nxt = IPPROTO_ICMPV6; if (m->m_pkthdr.rcvif) { /* XXX: This may not be the outgoing interface */ ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; } else ip6->ip6_hlim = ip6_defhlim; m->m_pkthdr.csum_flags = 0; icmp6->icmp6_cksum = 0; icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), plen); /* * XXX option handling */ m->m_flags &= ~(M_BCAST|M_MCAST); /* * To avoid a "too big" situation at an intermediate router * and the path MTU discovery process, specify the IPV6_MINMTU flag. * Note that only echo and node information replies are affected, * since the length of ICMP6 errors is limited to the minimum MTU. */ if (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, &outif) != 0 && outif) icmp6_ifstat_inc(outif, ifs6_out_error); if (outif) icmp6_ifoutstat_inc(outif, type, code); return; bad: m_freem(m); return; } static const char * icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, struct in6_addr *tgt6) { static char buf[1024]; snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6)); return buf; } void icmp6_redirect_input(struct mbuf *m, int off) { struct ifnet *ifp = m->m_pkthdr.rcvif; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct nd_redirect *nd_rd; int icmp6len = ntohs(ip6->ip6_plen); char *lladdr = NULL; int lladdrlen = 0; struct rtentry *rt = NULL; int is_router; int is_onlink; struct in6_addr src6 = ip6->ip6_src; struct in6_addr redtgt6; struct in6_addr reddst6; union nd_opts ndopts; if (!ifp) return; /* XXX if we are router, we don't update route by icmp6 redirect */ if (ip6_forwarding) goto freeit; if (!icmp6_rediraccept) goto freeit; IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); if (nd_rd == NULL) { ICMP6_STATINC(ICMP6_STAT_TOOSHORT); return; } redtgt6 = nd_rd->nd_rd_target; reddst6 = nd_rd->nd_rd_dst; if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) || in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) { goto freeit; } /* validation */ if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { nd6log((LOG_ERR, "ICMP6 redirect sent from %s rejected; " "must be from linklocal\n", ip6_sprintf(&src6))); goto bad; } if (ip6->ip6_hlim != 255) { nd6log((LOG_ERR, "ICMP6 redirect sent from %s rejected; " "hlim=%d (must be 255)\n", ip6_sprintf(&src6), ip6->ip6_hlim)); goto bad; } { /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ struct sockaddr_in6 sin6; struct in6_addr *gw6; sockaddr_in6_init(&sin6, &reddst6, 0, 0, 0); rt = rtalloc1((struct sockaddr *)&sin6, 0); if (rt) { if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6) { nd6log((LOG_ERR, "ICMP6 redirect rejected; no route " "with inet6 gateway found for redirect dst: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); RTFREE(rt); goto bad; } gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); if (memcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { nd6log((LOG_ERR, "ICMP6 redirect rejected; " "not equal to gw-for-src=%s (must be same): " "%s\n", ip6_sprintf(gw6), icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); RTFREE(rt); goto bad; } } else { nd6log((LOG_ERR, "ICMP6 redirect rejected; " "no route found for redirect dst: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); goto bad; } RTFREE(rt); rt = NULL; } if (IN6_IS_ADDR_MULTICAST(&reddst6)) { nd6log((LOG_ERR, "ICMP6 redirect rejected; " "redirect dst must be unicast: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); goto bad; } is_router = is_onlink = 0; if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) is_router = 1; /* router case */ if (memcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) is_onlink = 1; /* on-link destination case */ if (!is_router && !is_onlink) { nd6log((LOG_ERR, "ICMP6 redirect rejected; " "neither router case nor onlink case: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); goto bad; } /* validation passed */ icmp6len -= sizeof(*nd_rd); nd6_option_init(nd_rd + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log((LOG_INFO, "icmp6_redirect_input: " "invalid ND option, rejected: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); /* 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; } if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { nd6log((LOG_INFO, "icmp6_redirect_input: lladdrlen mismatch for %s " "(if %d, icmp6 packet %d): %s\n", ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); goto bad; } /* RFC 2461 8.3 */ nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); if (!is_onlink) { /* better router case. perform rtredirect. */ /* perform rtredirect */ struct sockaddr_in6 sdst; struct sockaddr_in6 sgw; struct sockaddr_in6 ssrc; unsigned long rtcount; struct rtentry *newrt = NULL; /* * do not install redirect route, if the number of entries * is too much (> hiwat). note that, the node (= host) will * work just fine even if we do not install redirect route * (there will be additional hops, though). */ rtcount = rt_timer_count(icmp6_redirect_timeout_q); if (0 <= ip6_maxdynroutes && rtcount >= ip6_maxdynroutes) goto freeit; if (0 <= icmp6_redirect_hiwat && rtcount > icmp6_redirect_hiwat) return; else if (0 <= icmp6_redirect_lowat && rtcount > icmp6_redirect_lowat) { /* * XXX nuke a victim, install the new one. */ } memset(&sdst, 0, sizeof(sdst)); memset(&sgw, 0, sizeof(sgw)); memset(&ssrc, 0, sizeof(ssrc)); sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6; sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw, NULL, RTF_GATEWAY | RTF_HOST, (struct sockaddr *)&ssrc, &newrt); if (newrt) { (void)rt_timer_add(newrt, icmp6_redirect_timeout, icmp6_redirect_timeout_q); rtfree(newrt); } } /* finally update cached route in each socket via pfctlinput */ { struct sockaddr_in6 sdst; sockaddr_in6_init(&sdst, &reddst6, 0, 0, 0); pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); #if defined(IPSEC) key_sa_routechange((struct sockaddr *)&sdst); #endif } freeit: m_freem(m); return; bad: ICMP6_STATINC(ICMP6_STAT_BADREDIRECT); m_freem(m); } void icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) { struct ifnet *ifp; /* my outgoing interface */ struct in6_addr *ifp_ll6; struct in6_addr *nexthop; struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */ struct mbuf *m = NULL; /* newly allocated one */ struct ip6_hdr *ip6; /* m as struct ip6_hdr */ struct nd_redirect *nd_rd; size_t maxlen; u_char *p; struct sockaddr_in6 src_sa; icmp6_errcount(ICMP6_STAT_OUTERRHIST, ND_REDIRECT, 0); /* if we are not router, we don't send icmp6 redirect */ if (!ip6_forwarding) goto fail; /* sanity check */ if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) goto fail; /* * Address check: * the source address must identify a neighbor, and * the destination address must not be a multicast address * [RFC 2461, sec 8.2] */ sip6 = mtod(m0, struct ip6_hdr *); sockaddr_in6_init(&src_sa, &sip6->ip6_src, 0, 0, 0); if (nd6_is_addr_neighbor(&src_sa, ifp) == 0) goto fail; if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst)) goto fail; /* what should we do here? */ /* rate limit */ if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0)) goto fail; /* * Since we are going to append up to 1280 bytes (= IPV6_MMTU), * we almost always ask for an mbuf cluster for simplicity. * (MHLEN < IPV6_MMTU is almost always true) */ MGETHDR(m, M_DONTWAIT, MT_HEADER); if (m && IPV6_MMTU >= MHLEN) { #if IPV6_MMTU >= MCLBYTES _MCLGET(m, mcl_cache, IPV6_MMTU, M_DONTWAIT); #else MCLGET(m, M_DONTWAIT); #endif } if (!m) goto fail; m->m_pkthdr.rcvif = NULL; m->m_len = 0; maxlen = M_TRAILINGSPACE(m); maxlen = min(IPV6_MMTU, maxlen); /* just for safety */ if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { goto fail; } { /* get ip6 linklocal address for ifp(my outgoing interface). */ struct in6_ifaddr *ia; if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY| IN6_IFF_ANYCAST)) == NULL) goto fail; ifp_ll6 = &ia->ia_addr.sin6_addr; } /* get ip6 linklocal address for the router. */ if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) { struct sockaddr_in6 *sin6; sin6 = (struct sockaddr_in6 *)rt->rt_gateway; nexthop = &sin6->sin6_addr; if (!IN6_IS_ADDR_LINKLOCAL(nexthop)) nexthop = NULL; } else nexthop = NULL; /* ip6 */ 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; /* ip6->ip6_src must be linklocal addr for my outgoing if. */ bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr)); bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr)); /* ND Redirect */ nd_rd = (struct nd_redirect *)(ip6 + 1); nd_rd->nd_rd_type = ND_REDIRECT; nd_rd->nd_rd_code = 0; nd_rd->nd_rd_reserved = 0; if (rt->rt_flags & RTF_GATEWAY) { /* * nd_rd->nd_rd_target must be a link-local address in * better router cases. */ if (!nexthop) goto fail; bcopy(nexthop, &nd_rd->nd_rd_target, sizeof(nd_rd->nd_rd_target)); bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, sizeof(nd_rd->nd_rd_dst)); } else { /* make sure redtgt == reddst */ nexthop = &sip6->ip6_dst; bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target, sizeof(nd_rd->nd_rd_target)); bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst, sizeof(nd_rd->nd_rd_dst)); } p = (u_char *)(nd_rd + 1); { /* target lladdr option */ struct rtentry *rt_nexthop = NULL; int len; const struct sockaddr_dl *sdl; struct nd_opt_hdr *nd_opt; char *lladdr; rt_nexthop = nd6_lookup(nexthop, 0, ifp); if (!rt_nexthop) goto nolladdropt; len = sizeof(*nd_opt) + ifp->if_addrlen; len = (len + 7) & ~7; /* round by 8 */ /* safety check */ if (len + (p - (u_char *)ip6) > maxlen) goto nolladdropt; if (!(rt_nexthop->rt_flags & RTF_GATEWAY) && (rt_nexthop->rt_flags & RTF_LLINFO) && (rt_nexthop->rt_gateway->sa_family == AF_LINK) && (sdl = satocsdl(rt_nexthop->rt_gateway)) && sdl->sdl_alen) { nd_opt = (struct nd_opt_hdr *)p; nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; nd_opt->nd_opt_len = len >> 3; lladdr = (char *)(nd_opt + 1); memcpy(lladdr, CLLADDR(sdl), ifp->if_addrlen); p += len; } } nolladdropt:; m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; /* just to be safe */ if (m0->m_flags & M_DECRYPTED) goto noredhdropt; if (p - (u_char *)ip6 > maxlen) goto noredhdropt; { /* redirected header option */ int len; struct nd_opt_rd_hdr *nd_opt_rh; /* * compute the maximum size for icmp6 redirect header option. * XXX room for auth header? */ len = maxlen - (p - (u_char *)ip6); len &= ~7; /* * Redirected header option spec (RFC2461 4.6.3) talks nothing * about padding/truncate rule for the original IP packet. * From the discussion on IPv6imp in Feb 1999, * the consensus was: * - "attach as much as possible" is the goal * - pad if not aligned (original size can be guessed by * original ip6 header) * Following code adds the padding if it is simple enough, * and truncates if not. */ if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { /* not enough room, truncate */ m_adj(m0, (len - sizeof(*nd_opt_rh)) - m0->m_pkthdr.len); } else { /* * enough room, truncate if not aligned. * we don't pad here for simplicity. */ size_t extra; extra = m0->m_pkthdr.len % 8; if (extra) { /* truncate */ m_adj(m0, -extra); } len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); } nd_opt_rh = (struct nd_opt_rd_hdr *)p; memset(nd_opt_rh, 0, sizeof(*nd_opt_rh)); nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER; nd_opt_rh->nd_opt_rh_len = len >> 3; p += sizeof(*nd_opt_rh); m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; /* connect m0 to m */ m->m_pkthdr.len += m0->m_pkthdr.len; m_cat(m, m0); m0 = NULL; } noredhdropt: if (m0) { m_freem(m0); m0 = NULL; } /* XXX: clear embedded link IDs in the inner header */ in6_clearscope(&sip6->ip6_src); in6_clearscope(&sip6->ip6_dst); in6_clearscope(&nd_rd->nd_rd_target); in6_clearscope(&nd_rd->nd_rd_dst); ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); nd_rd->nd_rd_cksum = 0; nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen)); /* send the packet to outside... */ if (ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL) != 0) icmp6_ifstat_inc(ifp, ifs6_out_error); icmp6_ifstat_inc(ifp, ifs6_out_msg); icmp6_ifstat_inc(ifp, ifs6_out_redirect); ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_REDIRECT); return; fail: if (m) m_freem(m); if (m0) m_freem(m0); } /* * ICMPv6 socket option processing. */ int icmp6_ctloutput(int op, struct socket *so, struct sockopt *sopt) { int error = 0; struct in6pcb *in6p = sotoin6pcb(so); if (sopt->sopt_level != IPPROTO_ICMPV6) return rip6_ctloutput(op, so, sopt); switch (op) { case PRCO_SETOPT: switch (sopt->sopt_name) { case ICMP6_FILTER: { struct icmp6_filter fil; error = sockopt_get(sopt, &fil, sizeof(fil)); if (error) break; memcpy(in6p->in6p_icmp6filt, &fil, sizeof(struct icmp6_filter)); error = 0; break; } default: error = ENOPROTOOPT; break; } break; case PRCO_GETOPT: switch (sopt->sopt_name) { case ICMP6_FILTER: { if (in6p->in6p_icmp6filt == NULL) { error = EINVAL; break; } error = sockopt_set(sopt, in6p->in6p_icmp6filt, sizeof(struct icmp6_filter)); break; } default: error = ENOPROTOOPT; break; } break; } return (error); } /* * Perform rate limit check. * Returns 0 if it is okay to send the icmp6 packet. * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate * limitation. * * XXX per-destination/type check necessary? */ static int icmp6_ratelimit( const struct in6_addr *dst, /* not used at this moment */ const int type, /* not used at this moment */ const int code) /* not used at this moment */ { int ret; ret = 0; /* okay to send */ /* PPS limit */ if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count, icmp6errppslim)) { /* The packet is subject to rate limit */ ret++; } return ret; } static struct rtentry * icmp6_mtudisc_clone(struct sockaddr *dst) { struct rtentry *rt; int error; rt = rtalloc1(dst, 1); if (rt == 0) return NULL; /* If we didn't get a host route, allocate one */ if ((rt->rt_flags & RTF_HOST) == 0) { struct rtentry *nrt; error = rtrequest((int) RTM_ADD, dst, (struct sockaddr *) rt->rt_gateway, NULL, RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); if (error) { rtfree(rt); return NULL; } nrt->rt_rmx = rt->rt_rmx; rtfree(rt); rt = nrt; } error = rt_timer_add(rt, icmp6_mtudisc_timeout, icmp6_mtudisc_timeout_q); if (error) { rtfree(rt); return NULL; } return rt; /* caller need to call rtfree() */ } static void icmp6_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) { if (rt == NULL) panic("icmp6_mtudisc_timeout: bad route to timeout"); if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == (RTF_DYNAMIC | RTF_HOST)) { rtrequest((int) RTM_DELETE, rt_getkey(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); } else { if (!(rt->rt_rmx.rmx_locks & RTV_MTU)) rt->rt_rmx.rmx_mtu = 0; } } static void icmp6_redirect_timeout(struct rtentry *rt, struct rttimer *r) { if (rt == NULL) panic("icmp6_redirect_timeout: bad route to timeout"); if ((rt->rt_flags & (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) == (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) { rtrequest((int) RTM_DELETE, rt_getkey(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); } } /* * sysctl helper routine for the net.inet6.icmp6.nd6 nodes. silly? */ static int sysctl_net_inet6_icmp6_nd6(SYSCTLFN_ARGS) { (void)&name; (void)&l; (void)&oname; if (namelen != 0) return (EINVAL); return (nd6_sysctl(rnode->sysctl_num, oldp, oldlenp, /*XXXUNCONST*/ __UNCONST(newp), newlen)); } static int sysctl_net_inet6_icmp6_stats(SYSCTLFN_ARGS) { return (NETSTAT_SYSCTL(icmp6stat_percpu, ICMP6_NSTATS)); } static void sysctl_net_inet6_icmp6_setup(struct sysctllog **clog) { extern int nd6_maxqueuelen; /* defined in nd6.c */ sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "net", NULL, NULL, 0, NULL, 0, CTL_NET, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "inet6", NULL, NULL, 0, NULL, 0, CTL_NET, PF_INET6, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "icmp6", SYSCTL_DESCR("ICMPv6 related settings"), NULL, 0, NULL, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_STRUCT, "stats", SYSCTL_DESCR("ICMPv6 transmission statistics"), sysctl_net_inet6_icmp6_stats, 0, NULL, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_STATS, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "rediraccept", SYSCTL_DESCR("Accept and process redirect messages"), NULL, 0, &icmp6_rediraccept, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_REDIRACCEPT, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "redirtimeout", SYSCTL_DESCR("Redirect generated route lifetime"), NULL, 0, &icmp6_redirtimeout, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_REDIRTIMEOUT, CTL_EOL); #if 0 /* obsoleted */ sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "errratelimit", NULL, NULL, 0, &icmp6_errratelimit, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ERRRATELIMIT, CTL_EOL); #endif sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "nd6_prune", SYSCTL_DESCR("Neighbor discovery prune interval"), NULL, 0, &nd6_prune, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_PRUNE, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "nd6_delay", SYSCTL_DESCR("First probe delay time"), NULL, 0, &nd6_delay, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_DELAY, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "nd6_umaxtries", SYSCTL_DESCR("Number of unicast discovery attempts"), NULL, 0, &nd6_umaxtries, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_UMAXTRIES, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "nd6_mmaxtries", SYSCTL_DESCR("Number of multicast discovery attempts"), NULL, 0, &nd6_mmaxtries, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_MMAXTRIES, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "nd6_useloopback", SYSCTL_DESCR("Use loopback interface for local traffic"), NULL, 0, &nd6_useloopback, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_USELOOPBACK, CTL_EOL); #if 0 /* obsoleted */ sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "nd6_proxyall", NULL, NULL, 0, &nd6_proxyall, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_PROXYALL, CTL_EOL); #endif sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "nodeinfo", SYSCTL_DESCR("Respond to node information requests"), NULL, 0, &icmp6_nodeinfo, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_NODEINFO, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "errppslimit", SYSCTL_DESCR("Maximum ICMP errors sent per second"), NULL, 0, &icmp6errppslim, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ERRPPSLIMIT, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "nd6_maxnudhint", SYSCTL_DESCR("Maximum neighbor unreachable hint count"), NULL, 0, &nd6_maxnudhint, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_MAXNUDHINT, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "mtudisc_hiwat", SYSCTL_DESCR("Low mark on MTU Discovery route timers"), NULL, 0, &icmp6_mtudisc_hiwat, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_MTUDISC_HIWAT, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "mtudisc_lowat", SYSCTL_DESCR("Low mark on MTU Discovery route timers"), NULL, 0, &icmp6_mtudisc_lowat, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_MTUDISC_LOWAT, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "nd6_debug", SYSCTL_DESCR("Enable neighbor discovery debug output"), NULL, 0, &nd6_debug, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_DEBUG, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_STRUCT, "nd6_drlist", SYSCTL_DESCR("Default router list"), sysctl_net_inet6_icmp6_nd6, 0, NULL, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_DRLIST, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_STRUCT, "nd6_prlist", SYSCTL_DESCR("Prefix list"), sysctl_net_inet6_icmp6_nd6, 0, NULL, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_PRLIST, CTL_EOL); sysctl_createv(clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "maxqueuelen", SYSCTL_DESCR("max packet queue len for a unresolved ND"), NULL, 1, &nd6_maxqueuelen, 0, CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_MAXQLEN, CTL_EOL); } void icmp6_statinc(u_int stat) { KASSERT(stat < ICMP6_NSTATS); ICMP6_STATINC(stat); }