/* $OpenBSD: icmp6.c,v 1.9 2000/02/28 14:30:40 itojun Exp $ */ /* $KAME: icmp6.c,v 1.71 2000/02/28 09:25:42 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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 #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 #undef IPSEC #include "faith.h" #include extern struct domain inet6domain; extern struct ip6protosw inet6sw[]; extern u_char ip6_protox[]; struct icmp6stat icmp6stat; extern struct in6pcb rawin6pcb; extern u_int icmp6errratelim; extern int icmp6_nodeinfo; static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL; extern int pmtu_expire; static void icmp6_mtudisc_update __P((struct in6_addr *, struct icmp6_hdr *, struct mbuf *)); static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int)); static const char *icmp6_redirect_diag __P((struct in6_addr *, struct in6_addr *, struct in6_addr *)); static struct mbuf * ni6_input __P((struct mbuf *, int)); static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *, struct ifnet **)); static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, struct ifnet *, int)); static struct rtentry *icmp6_mtudisc_clone __P((struct sockaddr *)); static void icmp6_mtudisc_timeout __P((struct rtentry *, struct rttimer *)); #ifdef COMPAT_RFC1885 static struct route_in6 icmp6_reflect_rt; #endif static struct timeval icmp6_nextsend = {0, 0}; void icmp6_init() { mld6_init(); icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire); } /* * Generate an error packet of type error in response to bad IP6 packet. */ void icmp6_error(m, type, code, param) struct mbuf *m; int type, code, param; { struct ip6_hdr *oip6, *nip6; struct icmp6_hdr *icmp6; u_int preplen; int off; u_char nxt; icmp6stat.icp6s_error++; #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), ); #else if (m->m_len < sizeof(struct ip6_hdr)) { m = m_pullup(m, sizeof(struct ip6_hdr)); if (m == NULL) return; } #endif oip6 = mtod(m, struct ip6_hdr *); /* * Multicast destination check. For unrecognized option errors, * this check has already done in ip6_unknown_opt(), so we can * check only for other errors. */ 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; /* 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 the erroneous packet is also an ICMP error, discard it. */ off = sizeof(struct ip6_hdr); nxt = oip6->ip6_nxt; while (1) { /* XXX: should avoid inf. loop explicitly? */ struct ip6_ext *ip6e; struct icmp6_hdr *icp; switch(nxt) { case IPPROTO_IPV6: case IPPROTO_IPV4: case IPPROTO_UDP: case IPPROTO_TCP: case IPPROTO_ESP: case IPPROTO_IPCOMP: case IPPROTO_FRAGMENT: /* * ICMPv6 error must not be fragmented. * XXX: but can we trust the sender? */ default: /* What if unknown header followed by ICMP error? */ goto generate; case IPPROTO_ICMPV6: #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), ); icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); #else IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off, sizeof(*icp)); if (icp == NULL) { icmp6stat.icp6s_tooshort++; return; } #endif 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. */ icmp6stat.icp6s_canterror++; goto freeit; } else { /* ICMPv6 informational */ goto generate; } case IPPROTO_HOPOPTS: case IPPROTO_DSTOPTS: case IPPROTO_ROUTING: case IPPROTO_AH: #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct ip6_ext), ); ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); #else IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, sizeof(*ip6e)); if (ip6e == NULL) { /*XXX stat */ return; } #endif if (nxt == IPPROTO_AH) off += (ip6e->ip6e_len + 2) << 2; else off += (ip6e->ip6e_len + 1) << 3; nxt = ip6e->ip6e_nxt; break; } } freeit: /* * If we can't tell wheter or not we can generate ICMP6, free it. */ m_freem(m); return; generate: oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */ /* Finally, do rate limitation check. */ if (icmp6_ratelimit(&oip6->ip6_src, type, code)) { icmp6stat.icp6s_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->m_len < preplen) m = m_pullup(m, preplen); if (m == NULL) { printf("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; if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src)) oip6->ip6_src.s6_addr16[1] = 0; if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst)) oip6->ip6_dst.s6_addr16[1] = 0; icmp6 = (struct icmp6_hdr *)(nip6 + 1); icmp6->icmp6_type = type; icmp6->icmp6_code = code; icmp6->icmp6_pptr = htonl((u_int32_t)param); icmp6stat.icp6s_outhist[type]++; icmp6_reflect(m, sizeof(struct ip6_hdr)); /*header order: IPv6 - ICMPv6*/ } /* * Process a received ICMP6 message. */ int icmp6_input(mp, offp, proto) struct mbuf **mp; int *offp, 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; struct sockaddr_in6 icmp6src; #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE); /* m might change if M_LOOP. So, call mtod after this */ #endif /* * Locate icmp6 structure in mbuf, and check * that not corrupted and of at least minimum length */ ip6 = mtod(m, struct ip6_hdr *); if (icmp6len < sizeof(struct icmp6_hdr)) { icmp6stat.icp6s_tooshort++; goto freeit; } /* * calculate the checksum */ #ifndef PULLDOWN_TEST icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); #else IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); if (icmp6 == NULL) { icmp6stat.icp6s_tooshort++; return IPPROTO_DONE; } #endif code = icmp6->icmp6_code; if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { log(LOG_ERR, "ICMP6 checksum error(%d|%x) %s\n", icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)); icmp6stat.icp6s_checksum++; goto freeit; } #if defined(NFAITH) && 0 < NFAITH if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) { /* * Deliver very specific ICMP6 type only. * This is important to deilver 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 #ifdef IPSEC /* drop it if it does not match the default policy */ if (ipsec6_in_reject(m, NULL)) { ipsecstat.in_polvio++; goto freeit; } #endif icmp6stat.icp6s_inhist[icmp6->icmp6_type]++; icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg); if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error); 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_PARAMPROB; break; #endif case ICMP6_DST_UNREACH_NOPORT: code = PRC_UNREACH_PORT; break; default: goto badcode; } goto deliver; break; case ICMP6_PACKET_TOO_BIG: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig); if (code != 0) goto badcode; code = PRC_MSGSIZE; /* * Updating the path MTU will be done after examining * intermediate extension headers. */ goto deliver; break; case ICMP6_TIME_EXCEEDED: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed); switch (code) { case ICMP6_TIME_EXCEED_TRANSIT: case ICMP6_TIME_EXCEED_REASSEMBLY: code += PRC_TIMXCEED_INTRANS; break; default: goto badcode; } goto deliver; break; 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; break; case ICMP6_ECHO_REQUEST: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo); if (code != 0) goto badcode; if ((n = m_copy(m, 0, M_COPYALL)) == NULL) { /* Give up remote */ break; } if ((n->m_flags & M_EXT) != 0 || n->m_len < off + sizeof(struct icmp6_hdr)) { struct mbuf *n0 = n; const int maxlen = sizeof(*nip6) + sizeof(*nicmp6); /* * Prepare an internal mbuf. m_pullup() doesn't * always copy the length we specified. */ if (maxlen >= MCLBYTES) { #ifdef DIAGNOSTIC printf("MCLBYTES too small\n"); #endif /* Give up remote */ m_freem(n0); break; } MGETHDR(n, M_DONTWAIT, n0->m_type); if (n && maxlen >= MHLEN) { MCLGET(n, M_DONTWAIT); if ((n->m_flags & M_EXT) == 0) { m_free(n); n = NULL; } } if (n == NULL) { /* Give up remote */ m_freem(n0); break; } M_COPY_PKTHDR(n, n0); /* * 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)); noff = sizeof(struct ip6_hdr); n->m_pkthdr.len = n->m_len = noff + sizeof(struct icmp6_hdr); /* * Adjust mbuf. ip6_plen will be adjusted in * ip6_output(). */ m_adj(n0, off + sizeof(struct icmp6_hdr)); n->m_pkthdr.len += n0->m_pkthdr.len; n->m_next = n0; n0->m_flags &= ~M_PKTHDR; } else { nip6 = mtod(n, struct ip6_hdr *); nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off); noff = off; } nicmp6->icmp6_type = ICMP6_ECHO_REPLY; nicmp6->icmp6_code = 0; if (n) { icmp6stat.icp6s_reflect++; icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++; icmp6_reflect(n, noff); } break; case ICMP6_ECHO_REPLY: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply); if (code != 0) goto badcode; break; case MLD6_LISTENER_QUERY: case MLD6_LISTENER_REPORT: if (icmp6len < sizeof(struct mld6_hdr)) goto badlen; if (icmp6->icmp6_type == MLD6_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 */ mld6_input(m, off); m = NULL; goto freeit; } mld6_input(n, off); /* m stays. */ break; case MLD6_LISTENER_DONE: icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone); if (icmp6len < sizeof(struct mld6_hdr)) /* necessary? */ goto badlen; break; /* nothing to be done in kernel */ case MLD6_MTRACE_RESP: case MLD6_MTRACE: /* XXX: these two are experimental. not officially defind. */ /* XXX: per-interface statistics? */ break; /* just pass it to applications */ case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ { enum { WRU, FQDN } mode; if (code != 0) goto badcode; if (!icmp6_nodeinfo) break; if (icmp6len == sizeof(struct icmp6_hdr) + 4) mode = WRU; else if (icmp6len >= sizeof(struct icmp6_hdr) + 8) /* XXX */ mode = FQDN; else goto badlen; if (mode == FQDN) { #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo), IPPROTO_DONE); #endif n = m_copy(m, 0, M_COPYALL); if (n) n = ni6_input(n, off); if (n) noff = sizeof(struct ip6_hdr); } else { u_char *p; int maxlen, maxhlen; maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4; if (maxlen >= MCLBYTES) { #ifdef DIAGNOSTIC printf("MCLBYTES too small\n"); #endif /* Give up remote */ break; } MGETHDR(n, M_DONTWAIT, m->m_type); if (n && 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_len = 0; maxhlen = M_TRAILINGSPACE(n) - 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); bzero(p, 4); bcopy(hostname, p + 4, maxhlen); noff = sizeof(struct ip6_hdr); M_COPY_PKTHDR(n, m); /* just for recvif */ 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) { icmp6stat.icp6s_reflect++; icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++; 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: printf("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 (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { icmp6stat.icp6s_tooshort++; goto freeit; } #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), IPPROTO_DONE); icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); #else IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6) + sizeof(struct ip6_hdr)); if (icmp6 == NULL) { icmp6stat.icp6s_tooshort++; return IPPROTO_DONE; } #endif bzero(&icmp6src, sizeof(icmp6src)); icmp6src.sin6_len = sizeof(struct sockaddr_in6); icmp6src.sin6_family = AF_INET6; icmp6src.sin6_addr = ((struct ip6_hdr *)(icmp6 + 1))->ip6_dst; /* Detect the upper level protocol */ { void (*ctlfunc) __P((int, struct sockaddr *, void *)); struct ip6_hdr *eip6 = (struct ip6_hdr *)(icmp6 + 1); 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 inf. loop explicitly? */ struct ip6_ext *eh; switch(nxt) { case IPPROTO_HOPOPTS: case IPPROTO_DSTOPTS: case IPPROTO_AH: #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(struct ip6_ext), IPPROTO_DONE); eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff); #else IP6_EXTHDR_GET(eh, struct ip6_ext *, m, eoff, sizeof(*eh)); if (eh == NULL) { icmp6stat.icp6s_tooshort++; return IPPROTO_DONE; } #endif 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). */ #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), IPPROTO_DONE); rth = (struct ip6_rthdr *)(mtod(m, caddr_t) + eoff); #else IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m, eoff, sizeof(*rth)); if (rth == NULL) { icmp6stat.icp6s_tooshort++; return IPPROTO_DONE; } #endif 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; #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, IPPROTO_DONE); rth0 = (struct ip6_rthdr0 *)(mtod(m, caddr_t) + eoff); #else IP6_EXTHDR_GET(rth0, struct ip6_rthdr0 *, m, eoff, rthlen); if (rth0 == NULL) { icmp6stat.icp6s_tooshort++; return IPPROTO_DONE; } #endif /* 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: #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(struct ip6_frag), IPPROTO_DONE); fh = (struct ip6_frag *)(mtod(m, caddr_t) + eoff); #else IP6_EXTHDR_GET(fh, struct ip6_frag *, m, eoff, sizeof(*fh)); if (fh == NULL) { icmp6stat.icp6s_tooshort++; return IPPROTO_DONE; } #endif /* * 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: #ifndef PULLDOWN_TEST icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); #else IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6) + sizeof(struct ip6_hdr)); if (icmp6 == NULL) { icmp6stat.icp6s_tooshort++; return IPPROTO_DONE; } #endif if (icmp6type == ICMP6_PACKET_TOO_BIG) { if (finaldst == NULL) finaldst = &((struct ip6_hdr *)(icmp6 + 1))->ip6_dst; icmp6_mtudisc_update(finaldst, icmp6, m); } ctlfunc = (void (*) __P((int, struct sockaddr *, void *))) (inet6sw[ip6_protox[nxt]].pr_ctlinput); if (ctlfunc) { ip6cp.ip6c_m = m; ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); ip6cp.ip6c_off = eoff; (*ctlfunc)(code, (struct sockaddr *)&icmp6src, &ip6cp); } } break; badcode: icmp6stat.icp6s_badcode++; break; badlen: icmp6stat.icp6s_badlen++; break; } rip6_input(&m, offp, IPPROTO_ICMPV6); return IPPROTO_DONE; freeit: m_freem(m); return IPPROTO_DONE; } static void icmp6_mtudisc_update(dst, icmp6, m) struct in6_addr *dst; struct icmp6_hdr *icmp6;/* we can assume the validity of the pointer */ struct mbuf *m; /* currently unused but added for scoped addrs */ { u_int mtu = ntohl(icmp6->icmp6_mtu); struct rtentry *rt = NULL; struct sockaddr_in6 sin6; bzero(&sin6, sizeof(sin6)); sin6.sin6_family = PF_INET6; sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_addr = *dst; /* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */ rt = rtalloc1((struct sockaddr *)&sin6, 1); /*clone*/ if (!rt || (rt->rt_flags & RTF_HOST) == 0) { if (rt) RTFREE(rt); rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6); } if (rt && (rt->rt_flags & RTF_HOST) && !(rt->rt_rmx.rmx_locks & RTV_MTU)) { if (mtu < IPV6_MMTU) { /* xxx */ rt->rt_rmx.rmx_locks |= RTV_MTU; } else if (mtu < rt->rt_ifp->if_mtu && rt->rt_rmx.rmx_mtu > mtu) { rt->rt_rmx.rmx_mtu = mtu; } } if (rt) RTFREE(rt); } /* * Process a Node Information Query */ #ifndef offsetof /* XXX */ #define offsetof(type, member) ((size_t)(&((type *)0)->member)) #endif static struct mbuf * ni6_input(m, off) struct mbuf *m; int off; { struct icmp6_nodeinfo *ni6, *nni6; struct mbuf *n = NULL; u_int16_t qtype; 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 */ #ifndef PULLDOWN_TEST ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); #else IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6)); if (ni6 == NULL) { /* m is already reclaimed */ return NULL; } #endif qtype = ntohs(ni6->ni_qtype); switch(qtype) { case NI_QTYPE_NOOP: break; /* no reply data */ case NI_QTYPE_SUPTYPES: goto bad; /* xxx: to be implemented */ break; case NI_QTYPE_FQDN: replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_name) + hostnamelen; break; case NI_QTYPE_NODEADDR: addrs = ni6_addrs(ni6, m, &ifp); if ((replylen += addrs * sizeof(struct in6_addr)) > MCLBYTES) replylen = MCLBYTES; /* XXX: we'll truncate later */ break; 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; replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_name) + hostnamelen; break; } /* allocate a mbuf to reply. */ MGETHDR(n, M_DONTWAIT, m->m_type); if (n == NULL) { m_freem(m); return(NULL); } M_COPY_PKTHDR(n, m); /* just for recvif */ 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, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr)); nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1); bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo)); /* qtype dependent procedure */ switch (qtype) { case NI_QTYPE_NOOP: nni6->ni_flags = 0; break; case NI_QTYPE_SUPTYPES: goto bad; /* xxx: to be implemented */ break; case NI_QTYPE_FQDN: if (hostnamelen > 255) { /* XXX: rare case, but may happen */ printf("ni6_input: " "hostname length(%d) is too large for reply\n", hostnamelen); goto bad; } fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); nni6->ni_flags = 0; /* XXX: meaningless TTL */ fqdn->ni_fqdn_ttl = 0; /* ditto. */ fqdn->ni_fqdn_namelen = hostnamelen; bcopy(hostname, &fqdn->ni_fqdn_name[0], hostnamelen); break; case NI_QTYPE_NODEADDR: { int lenlim, copied; if (n->m_flags & M_EXT) lenlim = MCLBYTES - sizeof(struct ip6_hdr) - sizeof(struct icmp6_nodeinfo); else lenlim = MHLEN - sizeof(struct ip6_hdr) - sizeof(struct icmp6_nodeinfo); 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; nni6->ni_code = ICMP6_NI_SUCESS; m_freem(m); return(n); bad: m_freem(m); if (n) m_freem(n); return(NULL); } #undef hostnamelen /* * calculate the number of addresses to be returned in the node info reply. */ static int ni6_addrs(ni6, m, ifpp) struct icmp6_nodeinfo *ni6; struct mbuf *m; struct ifnet **ifpp; { register struct ifnet *ifp; register struct in6_ifaddr *ifa6; register struct ifaddr *ifa; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); int addrs = 0, addrsofif, iffound = 0; for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) { addrsofif = 0; for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ifa6 = (struct in6_ifaddr *)ifa; if (!(ni6->ni_flags & NI_NODEADDR_FLAG_ALL) && IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &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-05] * So we don't support NI_NODEADDR_FLAG_COMPAT in * this function at this moment. */ if (ifa6->ia6_flags & IN6_IFF_ANYCAST) continue; /* we need only unicast addresses */ if ((ni6->ni_flags & (NI_NODEADDR_FLAG_LINKLOCAL | NI_NODEADDR_FLAG_SITELOCAL | NI_NODEADDR_FLAG_GLOBAL)) == 0) continue; /* What do we have to do about ::1? */ switch(in6_addrscope(&ifa6->ia_addr.sin6_addr)) { case IPV6_ADDR_SCOPE_LINKLOCAL: if (ni6->ni_flags & NI_NODEADDR_FLAG_LINKLOCAL) addrsofif++; break; case IPV6_ADDR_SCOPE_SITELOCAL: if (ni6->ni_flags & NI_NODEADDR_FLAG_SITELOCAL) addrsofif++; break; case IPV6_ADDR_SCOPE_GLOBAL: if (ni6->ni_flags & NI_NODEADDR_FLAG_GLOBAL) addrsofif++; break; default: continue; } } if (iffound) { *ifpp = ifp; return(addrsofif); } addrs += addrsofif; } return(addrs); } static int ni6_store_addrs(ni6, nni6, ifp0, resid) struct icmp6_nodeinfo *ni6, *nni6; struct ifnet *ifp0; int resid; { register struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet); register struct in6_ifaddr *ifa6; register struct ifaddr *ifa; int docopy, copied = 0; u_char *cp = (u_char *)(nni6 + 1); if (ifp0 == NULL && !(ni6->ni_flags & NI_NODEADDR_FLAG_ALL)) return(0); /* needless to copy */ for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) { for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next) { docopy = 0; if (ifa->ifa_addr->sa_family != AF_INET6) continue; ifa6 = (struct in6_ifaddr *)ifa; if (ifa6->ia6_flags & IN6_IFF_ANYCAST) { /* just experimental. not in the spec. */ if (ni6->ni_flags & NI_NODEADDR_FLAG_ANYCAST) docopy = 1; else continue; } else { /* unicast address */ if (ni6->ni_flags & NI_NODEADDR_FLAG_ANYCAST) continue; else docopy = 1; } /* What do we have to do about ::1? */ switch(in6_addrscope(&ifa6->ia_addr.sin6_addr)) { case IPV6_ADDR_SCOPE_LINKLOCAL: if (ni6->ni_flags & NI_NODEADDR_FLAG_LINKLOCAL) docopy = 1; break; case IPV6_ADDR_SCOPE_SITELOCAL: if (ni6->ni_flags & NI_NODEADDR_FLAG_SITELOCAL) docopy = 1; break; case IPV6_ADDR_SCOPE_GLOBAL: if (ni6->ni_flags & NI_NODEADDR_FLAG_GLOBAL) docopy = 1; break; default: continue; } if (docopy) { if (resid < sizeof(struct in6_addr)) { /* * We give up much more copy. * Set the truncate flag and return. */ nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; return(copied); } bcopy(&ifa6->ia_addr.sin6_addr, cp, sizeof(struct in6_addr)); /* XXX: KAME link-local hack; remove ifindex */ if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr)) ((struct in6_addr *)cp)->s6_addr16[1] = 0; cp += sizeof(struct in6_addr); resid -= sizeof(struct in6_addr); copied += sizeof(struct in6_addr); } } if (ifp0) /* we need search only on the specified IF */ break; } return(copied); } /* * Reflect the ip6 packet back to the source. * The caller MUST check if the destination is multicast or not. * This function is usually called with a unicast destination which * can be safely the source of the reply packet. But some exceptions * exist(e.g. ECHOREPLY, PATCKET_TOOBIG, "10" in OPTION type). * ``off'' points to the icmp6 header, counted from the top of the mbuf. */ void icmp6_reflect(m, off) struct mbuf *m; size_t off; { struct ip6_hdr *ip6; struct icmp6_hdr *icmp6; struct in6_ifaddr *ia; struct in6_addr t, *src = 0; int plen; int type, code; struct ifnet *outif = NULL; #ifdef COMPAT_RFC1885 int mtu = IPV6_MMTU; struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst; #endif /* too short to reflect */ if (off < sizeof(struct ip6_hdr)) { printf("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. */ 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), (caddr_t)&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((caddr_t)&nip6, mtod(m, caddr_t), 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. */ t = 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; /* XXX hack for link-local addresses */ if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); if (IN6_IS_ADDR_LINKLOCAL(&t)) t.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); #ifdef COMPAT_RFC1885 /* * xxx guess MTU * RFC 1885 requires that echo reply should be truncated if it * does not fit in with (return) path MTU, but the description was * removed in the new spec. */ if (icmp6_reflect_rt.ro_rt == 0 || ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) { if (icmp6_reflect_rt.ro_rt) { icmp6_reflect_rt.ro_rt = 0; } bzero(sin6, sizeof(*sin6)); sin6->sin6_family = PF_INET6; sin6->sin6_len = sizeof(struct sockaddr_in6); sin6->sin6_addr = ip6->ip6_dst; rtalloc((struct route *)&icmp6_reflect_rt.ro_rt); } if (icmp6_reflect_rt.ro_rt == 0) goto bad; if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST) && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu) mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu; if (mtu < m->m_pkthdr.len) { plen -= (m->m_pkthdr.len - mtu); m_adj(m, mtu - m->m_pkthdr.len); } #endif /* * 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 would be VERY rare, but is possible when * (for example) when we encounter an error while forwarding procedure * destined to a duplicated address of ours. */ for (ia = in6_ifaddr; ia; ia = ia->ia_next) if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) && (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) { src = &t; break; } if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) { /* * This is the case if the dst is our link-local address * and the sender is also ourseleves. */ src = &t; } if (src == 0) /* * This case matches to multicasts, our anycast, or unicasts * that we do not own. Select a source address which has the * same scope. * XXX: for (non link-local) multicast addresses, this might * not be a good choice. */ if ((ia = in6_ifawithscope(m->m_pkthdr.rcvif, &t)) != 0) src = &IA6_SIN6(ia)->sin6_addr; if (src == 0) 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->if_index].chlim; } 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); #ifdef IPSEC m->m_pkthdr.rcvif = NULL; #endif /*IPSEC*/ #ifdef COMPAT_RFC1885 ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif); #else ip6_output(m, NULL, NULL, 0, NULL, &outif); #endif if (outif) icmp6_ifoutstat_inc(outif, type, code); return; bad: m_freem(m); return; } void icmp6_fasttimo() { mld6_fasttimeo(); } static const char * icmp6_redirect_diag(src6, dst6, tgt6) 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(m, off) register 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; u_char *redirhdr = NULL; int redirhdrlen = 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 (!m || !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; #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, icmp6len,); nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); #else IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); if (nd_rd == NULL) { icmp6stat.icp6s_tooshort++; return; } #endif redtgt6 = nd_rd->nd_rd_target; reddst6 = nd_rd->nd_rd_dst; if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) redtgt6.s6_addr16[1] = htons(ifp->if_index); if (IN6_IS_ADDR_LINKLOCAL(&reddst6)) reddst6.s6_addr16[1] = htons(ifp->if_index); /* validation */ if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { log(LOG_ERR, "ICMP6 redirect sent from %s rejected; " "must be from linklocal\n", ip6_sprintf(&src6)); goto freeit; } if (ip6->ip6_hlim != 255) { log(LOG_ERR, "ICMP6 redirect sent from %s rejected; " "hlim=%d (must be 255)\n", ip6_sprintf(&src6), ip6->ip6_hlim); goto freeit; } { /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ struct sockaddr_in6 sin6; struct in6_addr *gw6; bzero(&sin6, sizeof(sin6)); sin6.sin6_family = AF_INET6; sin6.sin6_len = sizeof(struct sockaddr_in6); bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6)); rt = rtalloc1((struct sockaddr *)&sin6, 0); if (rt) { gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr); if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) { log(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 freeit; } } else { log(LOG_ERR, "ICMP6 redirect rejected; " "no route found for redirect dst: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); goto freeit; } RTFREE(rt); rt = NULL; } if (IN6_IS_ADDR_MULTICAST(&reddst6)) { log(LOG_ERR, "ICMP6 redirect rejected; " "redirect dst must be unicast: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); goto freeit; } is_router = is_onlink = 0; if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) is_router = 1; /* router case */ if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0) is_onlink = 1; /* on-link destination case */ if (!is_router && !is_onlink) { log(LOG_ERR, "ICMP6 redirect rejected; " "neither router case nor onlink case: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); goto freeit; } /* validation passed */ icmp6len -= sizeof(*nd_rd); nd6_option_init(nd_rd + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { log(LOG_INFO, "icmp6_redirect_input: " "invalid ND option, rejected: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6)); 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 (ndopts.nd_opts_rh) { redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len; redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */ } if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { log(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)); } /* 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; bzero(&sdst, sizeof(sdst)); bzero(&sgw, sizeof(sgw)); bzero(&ssrc, 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, (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST, (struct sockaddr *)&ssrc, (struct rtentry **)NULL ); } /* finally update cached route in each socket via pfctlinput */ { struct sockaddr_in6 sdst; #if 1 #else struct ip6protosw *pr; #endif bzero(&sdst, sizeof(sdst)); sdst.sin6_family = AF_INET6; sdst.sin6_len = sizeof(struct sockaddr_in6); bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); #if 1 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst); #else /* * do not use pfctlinput() here, we have different prototype for * xx_ctlinput() in ip6proto. */ for (pr = (struct ip6protosw *)inet6domain.dom_protosw; pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) { if (pr->pr_ctlinput) { (*pr->pr_ctlinput)(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst, NULL, NULL, 0); } } #endif #ifdef IPSEC key_sa_routechange((struct sockaddr *)&sdst); #endif } freeit: m_freem(m); } void icmp6_redirect_output(m0, rt) struct mbuf *m0; struct rtentry *rt; { struct ifnet *ifp; /* my outgoing interface */ struct in6_addr *ifp_ll6; struct in6_addr *router_ll6; 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 ifnet *outif = NULL; /* if we are not router, we don't send icmp6 redirect */ if (!ip6_forwarding || ip6_accept_rtadv) 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 *); if (nd6_is_addr_neighbor(&sip6->ip6_src, 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) */ #if IPV6_MMTU >= MCLBYTES # error assumption failed about IPV6_MMTU and MCLBYTES #endif MGETHDR(m, M_DONTWAIT, MT_HEADER); if (m && IPV6_MMTU >= MHLEN) MCLGET(m, M_DONTWAIT); if (!m) goto fail; maxlen = (m->m_flags & M_EXT) ? MCLBYTES : MHLEN; 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; router_ll6 = &sin6->sin6_addr; if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) router_ll6 = (struct in6_addr *)NULL; } else router_ll6 = (struct in6_addr *)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 (!router_ll6) goto fail; bcopy(router_ll6, &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 */ 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); if (!router_ll6) goto nolladdropt; { /* target lladdr option */ struct rtentry *rt_router = NULL; int len; struct sockaddr_dl *sdl; struct nd_opt_hdr *nd_opt; char *lladdr; rt_router = nd6_lookup(router_ll6, 0, ifp); if (!rt_router) 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_router->rt_flags & RTF_GATEWAY) && (rt_router->rt_flags & RTF_LLINFO) && (rt_router->rt_gateway->sa_family == AF_LINK) && (sdl = (struct sockaddr_dl *)rt_router->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); bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen); p += len; } } nolladdropt:; m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; /* just to be safe */ { /* 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; /* This is just for simplicity. */ if (m0->m_pkthdr.len != m0->m_len) { if (m0->m_next) { m_freem(m0->m_next); m0->m_next = NULL; } m0->m_pkthdr.len = m0->m_len; } /* * 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 (m0->m_next || m0->m_pkthdr.len != m0->m_len) panic("assumption failed in %s:%d\n", __FILE__, __LINE__); if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) { /* not enough room, truncate */ m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh); } else { /* enough room, pad or truncate */ size_t extra; extra = m0->m_pkthdr.len % 8; if (extra) { /* pad if easy enough, truncate if not */ if (8 - extra <= M_TRAILINGSPACE(m0)) { /* pad */ m0->m_len += (8 - extra); m0->m_pkthdr.len += (8 - extra); } else { /* truncate */ m0->m_pkthdr.len -= extra; m0->m_len -= extra; } } len = m0->m_pkthdr.len + sizeof(*nd_opt_rh); m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh); } nd_opt_rh = (struct nd_opt_rd_hdr *)p; bzero(nd_opt_rh, 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_next = m0; m->m_pkthdr.len = m->m_len + m0->m_len; } if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src)) sip6->ip6_src.s6_addr16[1] = 0; if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst)) sip6->ip6_dst.s6_addr16[1] = 0; #if 0 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) ip6->ip6_src.s6_addr16[1] = 0; if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) ip6->ip6_dst.s6_addr16[1] = 0; #endif if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target)) nd_rd->nd_rd_target.s6_addr16[1] = 0; if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst)) nd_rd->nd_rd_dst.s6_addr16[1] = 0; 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... */ #ifdef IPSEC m->m_pkthdr.rcvif = NULL; #endif /*IPSEC*/ ip6_output(m, NULL, NULL, 0, NULL, &outif); if (outif) { icmp6_ifstat_inc(outif, ifs6_out_msg); icmp6_ifstat_inc(outif, ifs6_out_redirect); } icmp6stat.icp6s_outhist[ND_REDIRECT]++; return; fail: if (m) m_freem(m); if (m0) m_freem(m0); } /* * 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(dst, type, code) 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 */ { struct timeval tp; long sec_diff, usec_diff; /* If we are not doing rate limitation, it is always okay to send */ if (!icmp6errratelim) return 0; tp = time; if (tp.tv_sec < icmp6_nextsend.tv_sec || (tp.tv_sec == icmp6_nextsend.tv_sec && tp.tv_usec < icmp6_nextsend.tv_usec)) { /* The packet is subject to rate limit */ return 1; } sec_diff = icmp6errratelim / 1000000; usec_diff = icmp6errratelim % 1000000; icmp6_nextsend.tv_sec = tp.tv_sec + sec_diff; if ((tp.tv_usec = tp.tv_usec + usec_diff) >= 1000000) { icmp6_nextsend.tv_sec++; icmp6_nextsend.tv_usec -= 1000000; } /* it is okay to send this */ return 0; } static struct rtentry * icmp6_mtudisc_clone(dst) 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, (struct sockaddr *) 0, RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); if (error) { rtfree(rt); rtfree(nrt); 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(rt, r) 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, (struct sockaddr *)rt_key(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0); } else { if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { rt->rt_rmx.rmx_mtu = 0; } } } #include #include int icmp6_sysctl(name, namelen, oldp, oldlenp, newp, newlen) int *name; u_int namelen; void *oldp; size_t *oldlenp; void *newp; size_t newlen; { /* All sysctl names at this level are terminal. */ if (namelen != 1) return ENOTDIR; switch (name[0]) { case ICMPV6CTL_REDIRACCEPT: return sysctl_int(oldp, oldlenp, newp, newlen, &icmp6_rediraccept); case ICMPV6CTL_REDIRTIMEOUT: return sysctl_int(oldp, oldlenp, newp, newlen, &icmp6_redirtimeout); case ICMPV6CTL_STATS: return sysctl_rdstruct(oldp, oldlenp, newp, &icmp6stat, sizeof(icmp6stat)); case ICMPV6CTL_ERRRATELIMIT: return sysctl_int(oldp, oldlenp, newp, newlen, &icmp6errratelim); case ICMPV6CTL_ND6_PRUNE: return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_prune); case ICMPV6CTL_ND6_DELAY: return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_delay); case ICMPV6CTL_ND6_UMAXTRIES: return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_umaxtries); case ICMPV6CTL_ND6_MMAXTRIES: return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_mmaxtries); case ICMPV6CTL_ND6_USELOOPBACK: return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_useloopback); case ICMPV6CTL_NODEINFO: return sysctl_int(oldp, oldlenp, newp, newlen, &icmp6_nodeinfo); default: return ENOPROTOOPT; } /* NOTREACHED */ }