/* $OpenBSD: icmp6.c,v 1.199 2017/02/05 16:04:14 jca 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 "carp.h" #include "pf.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 #if NCARP > 0 #include #endif #if NPF > 0 #include #endif struct icmp6stat icmp6stat; extern struct inpcbtable rawin6pcbtable; extern int icmp6errppslim; static int icmp6errpps_count = 0; static struct timeval icmp6errppslim_last; /* * 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 sockaddr_in6 *, u_int); }; LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks = LIST_HEAD_INITIALIZER(icmp6_mtudisc_callbacks); struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL; /* 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_lowat = -1; void icmp6_errcount(struct icmp6errstat *, int, int); int icmp6_rip6_input(struct mbuf **, int); int icmp6_ratelimit(const struct in6_addr *, const int, const int); const char *icmp6_redirect_diag(struct in6_addr *, struct in6_addr *, struct in6_addr *); int icmp6_notify_error(struct mbuf *, int, int, int); struct rtentry *icmp6_mtudisc_clone(struct sockaddr *, u_int); void icmp6_mtudisc_timeout(struct rtentry *, struct rttimer *); void icmp6_redirect_timeout(struct rtentry *, struct rttimer *); void icmp6_init(void) { mld6_init(); icmp6_mtudisc_timeout_q = rt_timer_queue_create(ip6_mtudisc_timeout); icmp6_redirect_timeout_q = rt_timer_queue_create(icmp6_redirtimeout); } void icmp6_errcount(struct icmp6errstat *stat, int type, int code) { switch (type) { case ICMP6_DST_UNREACH: switch (code) { case ICMP6_DST_UNREACH_NOROUTE: stat->icp6errs_dst_unreach_noroute++; return; case ICMP6_DST_UNREACH_ADMIN: stat->icp6errs_dst_unreach_admin++; return; case ICMP6_DST_UNREACH_BEYONDSCOPE: stat->icp6errs_dst_unreach_beyondscope++; return; case ICMP6_DST_UNREACH_ADDR: stat->icp6errs_dst_unreach_addr++; return; case ICMP6_DST_UNREACH_NOPORT: stat->icp6errs_dst_unreach_noport++; return; } break; case ICMP6_PACKET_TOO_BIG: stat->icp6errs_packet_too_big++; return; case ICMP6_TIME_EXCEEDED: switch (code) { case ICMP6_TIME_EXCEED_TRANSIT: stat->icp6errs_time_exceed_transit++; return; case ICMP6_TIME_EXCEED_REASSEMBLY: stat->icp6errs_time_exceed_reassembly++; return; } break; case ICMP6_PARAM_PROB: switch (code) { case ICMP6_PARAMPROB_HEADER: stat->icp6errs_paramprob_header++; return; case ICMP6_PARAMPROB_NEXTHEADER: stat->icp6errs_paramprob_nextheader++; return; case ICMP6_PARAMPROB_OPTION: stat->icp6errs_paramprob_option++; return; } break; case ND_REDIRECT: stat->icp6errs_redirect++; return; } stat->icp6errs_unknown++; } /* * Register a Path MTU Discovery callback. */ void icmp6_mtudisc_callback_register(void (*func)(struct sockaddr_in6 *, u_int)) { struct icmp6_mtudisc_callback *mc; LIST_FOREACH(mc, &icmp6_mtudisc_callbacks, 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); } /* * 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; icmp6stat.icp6s_error++; /* count per-type-code statistics */ icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code); if (m->m_len < sizeof(struct ip6_hdr)) { m = m_pullup(m, sizeof(struct ip6_hdr)); if (m == 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 Packet 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) { icmp6stat.icp6s_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. */ icmp6stat.icp6s_canterror++; goto freeit; } else { /* ICMPv6 informational - send the error */ } } 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)) { 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) { 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; if (IN6_IS_SCOPE_EMBED(&oip6->ip6_src)) oip6->ip6_src.s6_addr16[1] = 0; if (IN6_IS_SCOPE_EMBED(&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); /* * icmp6_reflect() is designed to be in the input path. * icmp6_error() can be called from both input and outut path, * and if we are in output path rcvif could contain bogus value. * clear m->m_pkthdr.ph_ifidx for safety, we should have enough * scope information in ip header (nip6). */ m->m_pkthdr.ph_ifidx = 0; icmp6stat.icp6s_outhist[type]++; icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ return; freeit: /* * If we can't tell wheter 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) { #if NCARP > 0 struct ifnet *ifp; #endif 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; char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; /* * 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 */ IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6)); if (icmp6 == NULL) { icmp6stat.icp6s_tooshort++; return IPPROTO_DONE; } 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, inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)))); icmp6stat.icp6s_checksum++; goto freeit; } #if NPF > 0 if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) { switch (icmp6->icmp6_type) { /* * These ICMP6 types map to other connections. They must be * delivered to pr_ctlinput() also for diverted connections. */ case ICMP6_DST_UNREACH: case ICMP6_PACKET_TOO_BIG: case ICMP6_TIME_EXCEEDED: case ICMP6_PARAM_PROB: break; default: goto raw; } } #endif /* NPF */ #if NCARP > 0 ifp = if_get(m->m_pkthdr.ph_ifidx); if (ifp == NULL) goto freeit; if (ifp->if_type == IFT_CARP && icmp6->icmp6_type == ICMP6_ECHO_REQUEST && carp_lsdrop(m, AF_INET6, ip6->ip6_src.s6_addr32, ip6->ip6_dst.s6_addr32)) { if_put(ifp); goto freeit; } if_put(ifp); #endif icmp6stat.icp6s_inhist[icmp6->icmp6_type]++; switch (icmp6->icmp6_type) { case ICMP6_DST_UNREACH: switch (code) { case ICMP6_DST_UNREACH_NOROUTE: code = PRC_UNREACH_NET; break; case ICMP6_DST_UNREACH_ADMIN: 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; case ICMP6_PACKET_TOO_BIG: /* MTU is checked in icmp6_mtudisc_update. */ code = PRC_MSGSIZE; /* * Updating the path MTU will be done after examining * intermediate extension headers. */ goto deliver; case ICMP6_TIME_EXCEEDED: 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: 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: 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 ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) { /* Give up local */ n = m; m = NULL; goto deliverecho; } /* * 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_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) { /* 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 local */ m_freem(n0); n = m; m = NULL; goto deliverecho; } M_MOVE_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_len = noff + sizeof(struct icmp6_hdr); /* * Adjust mbuf. ip6_plen will be adjusted in * ip6_output(). * n->m_pkthdr.len == n0->m_pkthdr.len at this point. */ n->m_pkthdr.len += noff + sizeof(struct icmp6_hdr); n->m_pkthdr.len -= (off + sizeof(struct icmp6_hdr)); m_adj(n0, off + sizeof(struct icmp6_hdr)); n->m_next = n0; } else { deliverecho: IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off, sizeof(*nicmp6)); 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); } if (!m) goto freeit; break; case ICMP6_ECHO_REPLY: if (code != 0) goto badcode; break; case MLD_LISTENER_QUERY: case MLD_LISTENER_REPORT: if (icmp6len < sizeof(struct mld_hdr)) goto badlen; 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 MLD_LISTENER_DONE: 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 */ /* IPv6 Node Information Queries are not supported */ break; case ICMP6_WRUREPLY: break; case ND_ROUTER_SOLICIT: 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: 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: 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: 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: 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=%u)\n", icmp6->icmp6_type, inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)), inet_ntop(AF_INET6, &ip6->ip6_dst, dst, sizeof(dst)), m->m_pkthdr.ph_ifidx)); 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: icmp6stat.icp6s_badcode++; break; badlen: icmp6stat.icp6s_badlen++; break; } #if NPF > 0 raw: #endif /* deliver the packet to appropriate sockets */ icmp6_rip6_input(&m, *offp); return IPPROTO_DONE; freeit: m_freem(m); return IPPROTO_DONE; } 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)) { icmp6stat.icp6s_tooshort++; goto freeit; } IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6) + sizeof(struct ip6_hdr)); if (icmp6 == NULL) { icmp6stat.icp6s_tooshort++; return (-1); } eip6 = (struct ip6_hdr *)(icmp6 + 1); /* Detect the upper level protocol */ { void (*ctlfunc)(int, struct sockaddr *, u_int, 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) { icmp6stat.icp6s_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) { icmp6stat.icp6s_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) { icmp6stat.icp6s_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) { icmp6stat.icp6s_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) { icmp6stat.icp6s_tooshort++; return (-1); } eip6 = (struct ip6_hdr *)(icmp6 + 1); bzero(&icmp6dst, sizeof(icmp6dst)); icmp6dst.sin6_len = sizeof(struct sockaddr_in6); icmp6dst.sin6_family = AF_INET6; if (finaldst == NULL) icmp6dst.sin6_addr = eip6->ip6_dst; else icmp6dst.sin6_addr = *finaldst; icmp6dst.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx, &icmp6dst.sin6_addr); if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst, NULL)) { /* should be impossbile */ nd6log((LOG_DEBUG, "icmp6_notify_error: in6_embedscope failed\n")); goto freeit; } /* * retrieve parameters from the inner IPv6 header, and convert * them into sockaddr structures. */ bzero(&icmp6src, sizeof(icmp6src)); icmp6src.sin6_len = sizeof(struct sockaddr_in6); icmp6src.sin6_family = AF_INET6; icmp6src.sin6_addr = eip6->ip6_src; icmp6src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx, &icmp6src.sin6_addr); if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src, NULL)) { /* should be impossbile */ nd6log((LOG_DEBUG, "icmp6_notify_error: in6_embedscope failed\n")); 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 NPF > 0 pf_pkt_addr_changed(m); #endif if (icmp6type == ICMP6_PACKET_TOO_BIG) { notifymtu = ntohl(icmp6->icmp6_mtu); ip6cp.ip6c_cmdarg = (void *)¬ifymtu; } ctlfunc = inet6sw[ip6_protox[nxt]].pr_ctlinput; if (ctlfunc) (*ctlfunc)(code, sin6tosa(&icmp6dst), m->m_pkthdr.ph_rtableid, &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; if (mtu < IPV6_MMTU) return; /* * allow non-validated cases if memory is plenty, to make traffic * from non-connected pcb happy. */ rtcount = rt_timer_queue_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; } bzero(&sin6, sizeof(sin6)); sin6.sin6_family = PF_INET6; sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_addr = *dst; /* XXX normally, this won't happen */ if (IN6_IS_ADDR_LINKLOCAL(dst)) { sin6.sin6_addr.s6_addr16[1] = htons(m->m_pkthdr.ph_ifidx); } sin6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx, &sin6.sin6_addr); rt = icmp6_mtudisc_clone(sin6tosa(&sin6), m->m_pkthdr.ph_rtableid); if (rt != NULL && ISSET(rt->rt_flags, RTF_HOST) && !(rt->rt_rmx.rmx_locks & RTV_MTU) && (rt->rt_rmx.rmx_mtu > mtu || rt->rt_rmx.rmx_mtu == 0)) { struct ifnet *ifp; ifp = if_get(rt->rt_ifidx); if (ifp != NULL && mtu < ifp->if_mtu) { icmp6stat.icp6s_pmtuchg++; rt->rt_rmx.rmx_mtu = mtu; } if_put(ifp); } rtfree(rt); /* * Notify protocols that the MTU for this destination * has changed. */ LIST_FOREACH(mc, &icmp6_mtudisc_callbacks, mc_list) (*mc->mc_func)(&sin6, m->m_pkthdr.ph_rtableid); } /* * XXX almost dup'ed code with rip6_input. */ int icmp6_rip6_input(struct mbuf **mp, int off) { struct mbuf *m = *mp; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct inpcb *in6p; struct inpcb *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; } bzero(&rip6src, sizeof(rip6src)); rip6src.sin6_len = sizeof(struct sockaddr_in6); rip6src.sin6_family = AF_INET6; /* KAME hack: recover scopeid */ in6_recoverscope(&rip6src, &ip6->ip6_src); TAILQ_FOREACH(in6p, &rawin6pcbtable.inpt_queue, inp_queue) { if (!(in6p->inp_flags & INP_IPV6)) continue; if (in6p->inp_ipv6.ip6_nxt != IPPROTO_ICMPV6) continue; #if NPF > 0 if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) { struct pf_divert *divert; /* XXX rdomain support */ if ((divert = pf_find_divert(m)) == NULL) continue; if (IN6_IS_ADDR_UNSPECIFIED(&divert->addr.v6)) goto divert_reply; if (!IN6_ARE_ADDR_EQUAL(&in6p->inp_laddr6, &divert->addr.v6)) continue; } else divert_reply: #endif if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->inp_laddr6) && !IN6_ARE_ADDR_EQUAL(&in6p->inp_laddr6, &ip6->ip6_dst)) continue; if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->inp_faddr6) && !IN6_ARE_ADDR_EQUAL(&in6p->inp_faddr6, &ip6->ip6_src)) continue; if (in6p->inp_icmp6filt && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, in6p->inp_icmp6filt)) continue; if (last) { struct mbuf *n; if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) { if (last->inp_flags & IN6P_CONTROLOPTS) ip6_savecontrol(last, n, &opts); /* strip intermediate headers */ m_adj(n, off); if (sbappendaddr(&last->inp_socket->so_rcv, sin6tosa(&rip6src), n, opts) == 0) { /* should notify about lost packet */ m_freem(n); m_freem(opts); } else sorwakeup(last->inp_socket); opts = NULL; } } last = in6p; } if (last) { if (last->inp_flags & IN6P_CONTROLOPTS) ip6_savecontrol(last, m, &opts); /* strip intermediate headers */ m_adj(m, off); if (sbappendaddr(&last->inp_socket->so_rcv, sin6tosa(&rip6src), m, opts) == 0) { m_freem(m); m_freem(opts); } else sorwakeup(last->inp_socket); } else { struct counters_ref ref; uint64_t *counters; m_freem(m); counters = counters_enter(&ref, ip6counters); counters[ip6s_delivered]--; counters_leave(&ref, ip6counters); } 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 rtentry *rt = NULL; struct ip6_hdr *ip6; struct icmp6_hdr *icmp6; struct in6_ifaddr *ia6; struct in6_addr t, *src = NULL; struct sockaddr_in6 sa6_src, sa6_dst; /* 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), (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; } } ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_nxt = IPPROTO_ICMPV6; icmp6 = (struct icmp6_hdr *)(ip6 + 1); 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: make sure to embed scope zone information, using * already embedded IDs or the received interface (if any). * Note that rcvif may be NULL. * TODO: scoped routing case (XXX). */ bzero(&sa6_src, sizeof(sa6_src)); sa6_src.sin6_family = AF_INET6; sa6_src.sin6_len = sizeof(sa6_src); sa6_src.sin6_addr = ip6->ip6_dst; in6_recoverscope(&sa6_src, &ip6->ip6_dst); in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL); bzero(&sa6_dst, sizeof(sa6_dst)); sa6_dst.sin6_family = AF_INET6; sa6_dst.sin6_len = sizeof(sa6_dst); sa6_dst.sin6_addr = t; in6_recoverscope(&sa6_dst, &t); in6_embedscope(&t, &sa6_dst, NULL); /* * If the incoming packet was addressed directly to us (i.e. unicast), * use dst as the src for the reply. * The IN6_IFF_TENTATIVE|IN6_IFF_DUPLICATED case would be VERY rare, * but is possible (for example) when we encounter an error while * forwarding procedure destined to a duplicated address of ours. */ TAILQ_FOREACH(ia6, &in6_ifaddr, ia_list) if (IN6_ARE_ADDR_EQUAL(&t, &ia6->ia_addr.sin6_addr) && (ia6->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_TENTATIVE| IN6_IFF_DUPLICATED)) == 0) { src = &t; break; } if (ia6 == 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 ourselves. */ src = &t; } if (src == NULL) { /* * 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. */ rt = rtalloc(sin6tosa(&sa6_src), RT_RESOLVE, m->m_pkthdr.ph_rtableid); if (!rtisvalid(rt)) { char addr[INET6_ADDRSTRLEN]; nd6log((LOG_DEBUG, "%s: source can't be determined: dst=%s\n", __func__, inet_ntop(AF_INET6, &sa6_src.sin6_addr, addr, sizeof(addr)))); rtfree(rt); goto bad; } src = &ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr; } ip6->ip6_src = *src; rtfree(rt); ip6->ip6_flow = 0; ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; ip6->ip6_nxt = IPPROTO_ICMPV6; ip6->ip6_hlim = ip6_defhlim; icmp6->icmp6_cksum = 0; m->m_pkthdr.csum_flags = M_ICMP_CSUM_OUT; /* * 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 NPF > 0 pf_pkt_addr_changed(m); #endif ip6_send(m); return; bad: m_freem(m); return; } void icmp6_fasttimo(void) { mld6_fasttimeo(); } const char * icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, struct in6_addr *tgt6) { static char buf[1024]; /* XXX */ char src[INET6_ADDRSTRLEN]; char dst[INET6_ADDRSTRLEN]; char tgt[INET6_ADDRSTRLEN]; snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", inet_ntop(AF_INET6, src6, src, sizeof(src)), inet_ntop(AF_INET6, dst6, dst, sizeof(dst)), inet_ntop(AF_INET6, tgt6, tgt, sizeof(tgt))); return buf; } void icmp6_redirect_input(struct mbuf *m, int off) { struct ifnet *ifp; 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; char addr[INET6_ADDRSTRLEN]; ifp = if_get(m->m_pkthdr.ph_ifidx); if (ifp == NULL) return; /* XXX if we are router, we don't update route by icmp6 redirect */ if (ip6_forwarding) goto freeit; if (!(ifp->if_xflags & IFXF_AUTOCONF6)) goto freeit; IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len); if (nd_rd == NULL) { icmp6stat.icp6s_tooshort++; if_put(ifp); return; } 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)) { nd6log((LOG_ERR, "ICMP6 redirect sent from %s rejected; " "must be from linklocal\n", inet_ntop(AF_INET6, &src6, addr, sizeof(addr)))); goto bad; } if (ip6->ip6_hlim != 255) { nd6log((LOG_ERR, "ICMP6 redirect sent from %s rejected; " "hlim=%d (must be 255)\n", inet_ntop(AF_INET6, &src6, addr, sizeof(addr)), ip6->ip6_hlim)); goto bad; } 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; } { /* 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 = rtalloc(sin6tosa(&sin6), 0, m->m_pkthdr.ph_rtableid); 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 = &(satosin6(rt->rt_gateway)->sin6_addr); if (bcmp(&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", inet_ntop(AF_INET6, gw6, addr, sizeof(addr)), 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; } 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) { 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", inet_ntop(AF_INET6, &redtgt6, addr, sizeof(addr)), 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_queue_count(icmp6_redirect_timeout_q); if (0 <= ip6_maxdynroutes && rtcount >= ip6_maxdynroutes) goto freeit; else if (0 <= icmp6_redirect_lowat && rtcount > icmp6_redirect_lowat) { /* * XXX nuke a victim, install the new one. */ } 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(sin6tosa(&sdst), sin6tosa(&sgw), sin6tosa(&ssrc), &newrt, m->m_pkthdr.ph_rtableid); if (newrt) { (void)rt_timer_add(newrt, icmp6_redirect_timeout, icmp6_redirect_timeout_q, m->m_pkthdr.ph_rtableid); rtfree(newrt); } } /* finally update cached route in each socket via pfctlinput */ { struct sockaddr_in6 sdst; 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)); pfctlinput(PRC_REDIRECT_HOST, sin6tosa(&sdst)); } freeit: if_put(ifp); m_freem(m); return; bad: if_put(ifp); icmp6stat.icp6s_badredirect++; m_freem(m); } void icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt) { struct ifnet *ifp = NULL; 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(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0); /* if we are not router, we don't send icmp6 redirect */ if (!ip6_forwarding) goto fail; /* sanity check */ if (m0 == NULL || !rtisvalid(rt)) goto fail; ifp = if_get(rt->rt_ifidx); if (ifp == NULL) 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 *); bzero(&src_sa, sizeof(src_sa)); src_sa.sin6_family = AF_INET6; src_sa.sin6_len = sizeof(src_sa); src_sa.sin6_addr = sip6->ip6_src; /* we don't currently use sin6_scope_id, but eventually use it */ src_sa.sin6_scope_id = in6_addr2scopeid(ifp->if_index, &sip6->ip6_src); 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) */ #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; m->m_pkthdr.ph_ifidx = 0; 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 *ia6; if ((ia6 = in6ifa_ifpforlinklocal(ifp, IN6_IFF_TENTATIVE| IN6_IFF_DUPLICATED|IN6_IFF_ANYCAST)) == NULL) goto fail; ifp_ll6 = &ia6->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 = satosin6(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 *nrt; int len; struct sockaddr_dl *sdl; struct nd_opt_hdr *nd_opt; char *lladdr; 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; nrt = nd6_lookup(nexthop, 0, ifp, ifp->if_rdomain); if ((nrt != NULL) && (nrt->rt_flags & (RTF_GATEWAY|RTF_LLINFO)) == RTF_LLINFO && (nrt->rt_gateway->sa_family == AF_LINK) && (sdl = satosdl(nrt->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; } rtfree(nrt); } nolladdropt:; m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; /* just to be safe */ 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; 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_pkthdr.len += m0->m_pkthdr.len; m_cat(m, m0); m0 = NULL; } noredhdropt: m_freem(m0); m0 = NULL; sip6 = mtod(m, struct ip6_hdr *); 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; m->m_pkthdr.csum_flags = M_ICMP_CSUM_OUT; /* send the packet to outside... */ ip6_output(m, NULL, NULL, 0, NULL, NULL); icmp6stat.icp6s_outhist[ND_REDIRECT]++; if_put(ifp); return; fail: if_put(ifp); m_freem(m); m_freem(m0); } /* * ICMPv6 socket option processing. */ int icmp6_ctloutput(int op, struct socket *so, int level, int optname, struct mbuf *m) { int error = 0; struct inpcb *in6p = sotoinpcb(so); if (level != IPPROTO_ICMPV6) { if (op == PRCO_SETOPT) (void)m_free(m); return EINVAL; } switch (op) { case PRCO_SETOPT: switch (optname) { case ICMP6_FILTER: { struct icmp6_filter *p; if (m == NULL || m->m_len != sizeof(*p)) { error = EMSGSIZE; break; } p = mtod(m, struct icmp6_filter *); if (!p || !in6p->inp_icmp6filt) { error = EINVAL; break; } bcopy(p, in6p->inp_icmp6filt, sizeof(struct icmp6_filter)); error = 0; break; } default: error = ENOPROTOOPT; break; } m_freem(m); break; case PRCO_GETOPT: switch (optname) { case ICMP6_FILTER: { struct icmp6_filter *p; if (!in6p->inp_icmp6filt) { error = EINVAL; break; } m->m_len = sizeof(struct icmp6_filter); p = mtod(m, struct icmp6_filter *); bcopy(in6p->inp_icmp6filt, p, sizeof(struct icmp6_filter)); error = 0; 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? * * dst - not used at this moment * type - not used at this moment * code - not used at this moment */ int icmp6_ratelimit(const struct in6_addr *dst, const int type, const int code) { /* PPS limit */ if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count, icmp6errppslim)) return 1; /* The packet is subject to rate limit */ return 0; /* okay to send */ } struct rtentry * icmp6_mtudisc_clone(struct sockaddr *dst, u_int rtableid) { struct rtentry *rt; int error; rt = rtalloc(dst, RT_RESOLVE, rtableid); /* Check if the route is actually usable */ if (!rtisvalid(rt) || (rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE))) { rtfree(rt); return (NULL); } /* If we didn't get a host route, allocate one */ if ((rt->rt_flags & RTF_HOST) == 0) { struct rtentry *nrt; struct rt_addrinfo info; struct sockaddr_rtlabel sa_rl; memset(&info, 0, sizeof(info)); info.rti_ifa = rt->rt_ifa; info.rti_flags = RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC; info.rti_info[RTAX_DST] = dst; info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; info.rti_info[RTAX_LABEL] = rtlabel_id2sa(rt->rt_labelid, &sa_rl); error = rtrequest(RTM_ADD, &info, rt->rt_priority, &nrt, rtableid); 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, rtableid); if (error) { rtfree(rt); return (NULL); } return (rt); } void icmp6_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) { struct ifnet *ifp; NET_ASSERT_LOCKED(); ifp = if_get(rt->rt_ifidx); if (ifp == NULL) return; if ((rt->rt_flags & (RTF_DYNAMIC|RTF_HOST)) == (RTF_DYNAMIC|RTF_HOST)) { rtdeletemsg(rt, ifp, r->rtt_tableid); } else { if (!(rt->rt_rmx.rmx_locks & RTV_MTU)) rt->rt_rmx.rmx_mtu = 0; } if_put(ifp); } void icmp6_redirect_timeout(struct rtentry *rt, struct rttimer *r) { struct ifnet *ifp; NET_ASSERT_LOCKED(); ifp = if_get(rt->rt_ifidx); if (ifp == NULL) return; if ((rt->rt_flags & (RTF_DYNAMIC|RTF_HOST)) == (RTF_DYNAMIC|RTF_HOST)) { rtdeletemsg(rt, ifp, r->rtt_tableid); } if_put(ifp); } int *icmpv6ctl_vars[ICMPV6CTL_MAXID] = ICMPV6CTL_VARS; int icmp6_sysctl(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_STATS: return sysctl_rdstruct(oldp, oldlenp, newp, &icmp6stat, sizeof(icmp6stat)); case ICMPV6CTL_ND6_DRLIST: case ICMPV6CTL_ND6_PRLIST: return nd6_sysctl(name[0], oldp, oldlenp, newp, newlen); default: if (name[0] < ICMPV6CTL_MAXID) return (sysctl_int_arr(icmpv6ctl_vars, name, namelen, oldp, oldlenp, newp, newlen)); return ENOPROTOOPT; } /* NOTREACHED */ }