diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c index 8f039d6dd196..ef4216b844b5 100644 --- a/sys/netinet6/icmp6.c +++ b/sys/netinet6/icmp6.c @@ -1,2775 +1,2914 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * 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. * * $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ */ /*- * 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. */ #include #define MBUF_PRIVATE /* XXXRW: Optimisation tries to avoid M_EXT mbufs */ #include "opt_inet.h" #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern ip6proto_ctlinput_t *ip6_ctlprotox[]; VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat); VNET_PCPUSTAT_SYSINIT(icmp6stat); SYSCTL_VNET_PCPUSTAT(_net_inet6_icmp6, ICMPV6CTL_STATS, stats, struct icmp6stat, icmp6stat, "ICMPv6 statistics (struct icmp6stat, netinet/icmp6.h)"); #ifdef VIMAGE VNET_PCPUSTAT_SYSUNINIT(icmp6stat); #endif /* VIMAGE */ VNET_DEFINE_STATIC(int, icmp6_rediraccept) = 1; #define V_icmp6_rediraccept VNET(icmp6_rediraccept) SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_REDIRACCEPT, rediraccept, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6_rediraccept), 0, "Accept ICMPv6 redirect messages"); VNET_DEFINE_STATIC(int, icmp6_redirtimeout) = 10 * 60; /* 10 minutes */ #define V_icmp6_redirtimeout VNET(icmp6_redirtimeout) SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_REDIRTIMEOUT, redirtimeout, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6_redirtimeout), 0, "Delay in seconds before expiring redirect route"); VNET_DEFINE_STATIC(int, icmp6_nodeinfo) = 0; #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_NODEINFO, nodeinfo, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6_nodeinfo), 0, "Mask of enabled RFC4620 node information query types"); VNET_DECLARE(struct inpcbinfo, ripcbinfo); #define V_ripcbinfo VNET(ripcbinfo) -VNET_DEFINE_STATIC(int, icmp6errppslim) = 100; -#define V_icmp6errppslim VNET(icmp6errppslim) -SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ERRPPSLIMIT, errppslimit, - CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6errppslim), 0, - "Maximum number of ICMPv6 error messages per second"); - -VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0; -VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last); - -#define V_icmp6errpps_count VNET(icmp6errpps_count) -#define V_icmp6errppslim_last VNET(icmp6errppslim_last) - static void icmp6_errcount(int, int); static int icmp6_rip6_input(struct mbuf **, int); static void icmp6_reflect(struct mbuf *, size_t); static const char *icmp6_redirect_diag(struct in6_addr *, struct in6_addr *, struct in6_addr *); static struct mbuf *ni6_input(struct mbuf *, int, struct prison *); static struct mbuf *ni6_nametodns(const char *, int, int); static int ni6_dnsmatch(const char *, int, const char *, int); static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *, struct ifnet **, struct in6_addr *); static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *, struct ifnet *, int); static int icmp6_notify_error(struct mbuf **, int, int); /* * Kernel module interface for updating icmp6stat. The argument is an index * into icmp6stat treated as an array of u_quad_t. While this encodes the * general layout of icmp6stat into the caller, it doesn't encode its * location, so that future changes to add, for example, per-CPU stats * support won't cause binary compatibility problems for kernel modules. */ void kmod_icmp6stat_inc(int statnum) { counter_u64_add(VNET(icmp6stat)[statnum], 1); } static void icmp6_errcount(int type, int code) { switch (type) { case ICMP6_DST_UNREACH: switch (code) { case ICMP6_DST_UNREACH_NOROUTE: ICMP6STAT_INC(icp6s_odst_unreach_noroute); return; case ICMP6_DST_UNREACH_ADMIN: ICMP6STAT_INC(icp6s_odst_unreach_admin); return; case ICMP6_DST_UNREACH_BEYONDSCOPE: ICMP6STAT_INC(icp6s_odst_unreach_beyondscope); return; case ICMP6_DST_UNREACH_ADDR: ICMP6STAT_INC(icp6s_odst_unreach_addr); return; case ICMP6_DST_UNREACH_NOPORT: ICMP6STAT_INC(icp6s_odst_unreach_noport); return; } break; case ICMP6_PACKET_TOO_BIG: ICMP6STAT_INC(icp6s_opacket_too_big); return; case ICMP6_TIME_EXCEEDED: switch (code) { case ICMP6_TIME_EXCEED_TRANSIT: ICMP6STAT_INC(icp6s_otime_exceed_transit); return; case ICMP6_TIME_EXCEED_REASSEMBLY: ICMP6STAT_INC(icp6s_otime_exceed_reassembly); return; } break; case ICMP6_PARAM_PROB: switch (code) { case ICMP6_PARAMPROB_HEADER: ICMP6STAT_INC(icp6s_oparamprob_header); return; case ICMP6_PARAMPROB_NEXTHEADER: ICMP6STAT_INC(icp6s_oparamprob_nextheader); return; case ICMP6_PARAMPROB_OPTION: ICMP6STAT_INC(icp6s_oparamprob_option); return; } break; case ND_REDIRECT: ICMP6STAT_INC(icp6s_oredirect); return; } ICMP6STAT_INC(icp6s_ounknown); } /* * A wrapper function for icmp6_error() necessary when the erroneous packet * may not contain enough scope zone information. */ void icmp6_error2(struct mbuf *m, int type, int code, int param, struct ifnet *ifp) { struct ip6_hdr *ip6; if (ifp == NULL) return; if (m->m_len < sizeof(struct ip6_hdr)) { m = m_pullup(m, sizeof(struct ip6_hdr)); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); return; } } ip6 = mtod(m, struct ip6_hdr *); if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) return; if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) return; icmp6_error(m, type, code, param); } /* * Generate an error packet of type error in response to bad IP6 packet. */ void icmp6_error(struct mbuf *m, int type, int code, int param) { struct ip6_hdr *oip6, *nip6; struct icmp6_hdr *icmp6; struct epoch_tracker et; u_int preplen; int off; int nxt; ICMP6STAT_INC(icp6s_error); /* count per-type-code statistics */ icmp6_errcount(type, code); #ifdef M_DECRYPTED /*not openbsd*/ if (m->m_flags & M_DECRYPTED) { ICMP6STAT_INC(icp6s_canterror); goto freeit; } #endif if (m->m_len < sizeof(struct ip6_hdr)) { m = m_pullup(m, sizeof(struct ip6_hdr)); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); 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; if (m->m_len < off + sizeof(struct icmp6_hdr)) { m = m_pullup(m, off + sizeof(struct icmp6_hdr)); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); return; } } oip6 = mtod(m, struct ip6_hdr *); icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); 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_INC(icp6s_canterror); goto freeit; } else { /* ICMPv6 informational - send the error */ } } else { /* non-ICMPv6 - send the error */ } /* Finally, do rate limitation check. */ if (icmp6_ratelimit(&oip6->ip6_src, type, code)) 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_NOWAIT); /* FIB is also copied over. */ if (m == NULL) { nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__)); return; } nip6 = mtod(m, struct ip6_hdr *); nip6->ip6_src = oip6->ip6_src; nip6->ip6_dst = oip6->ip6_dst; in6_clearscope(&oip6->ip6_src); in6_clearscope(&oip6->ip6_dst); icmp6 = (struct icmp6_hdr *)(nip6 + 1); icmp6->icmp6_type = type; icmp6->icmp6_code = code; icmp6->icmp6_pptr = htonl((u_int32_t)param); ICMP6STAT_INC(icp6s_outhist[type]); NET_EPOCH_ENTER(et); icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */ NET_EPOCH_EXIT(et); return; freeit: /* * If we can't tell whether or not we can generate ICMP6, free it. */ m_freem(m); } int icmp6_errmap(const struct icmp6_hdr *icmp6) { switch (icmp6->icmp6_type) { case ICMP6_DST_UNREACH: switch (icmp6->icmp6_code) { case ICMP6_DST_UNREACH_NOROUTE: case ICMP6_DST_UNREACH_ADDR: return (EHOSTUNREACH); case ICMP6_DST_UNREACH_NOPORT: case ICMP6_DST_UNREACH_ADMIN: return (ECONNREFUSED); case ICMP6_DST_UNREACH_BEYONDSCOPE: return (ENOPROTOOPT); default: return (0); /* Shouldn't happen. */ } case ICMP6_PACKET_TOO_BIG: return (EMSGSIZE); case ICMP6_TIME_EXCEEDED: switch (icmp6->icmp6_code) { case ICMP6_TIME_EXCEED_TRANSIT: return (EHOSTUNREACH); case ICMP6_TIME_EXCEED_REASSEMBLY: return (0); default: return (0); /* Shouldn't happen. */ } case ICMP6_PARAM_PROB: switch (icmp6->icmp6_code) { case ICMP6_PARAMPROB_NEXTHEADER: return (ECONNREFUSED); case ICMP6_PARAMPROB_HEADER: case ICMP6_PARAMPROB_OPTION: return (ENOPROTOOPT); default: return (0); /* Shouldn't happen. */ } default: return (0); } } /* * Process a received ICMP6 message. */ int icmp6_input(struct mbuf **mp, int *offp, int proto) { struct mbuf *m, *n; struct ifnet *ifp; struct ip6_hdr *ip6, *nip6; struct icmp6_hdr *icmp6, *nicmp6; char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; int code, error, icmp6len, ip6len, noff, off, sum; NET_EPOCH_ASSERT(); m = *mp; off = *offp; if (m->m_len < off + sizeof(struct icmp6_hdr)) { m = m_pullup(m, off + sizeof(struct icmp6_hdr)); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); *mp = m; return (IPPROTO_DONE); } } /* * Locate icmp6 structure in mbuf, and check * that not corrupted and of at least minimum length */ icmp6len = m->m_pkthdr.len - off; if (icmp6len < sizeof(struct icmp6_hdr)) { ICMP6STAT_INC(icp6s_tooshort); goto freeit; } ip6 = mtod(m, struct ip6_hdr *); ifp = m->m_pkthdr.rcvif; /* * Check multicast group membership. * Note: SSM filters are not applied for ICMPv6 traffic. */ if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { struct in6_multi *inm; inm = in6m_lookup(ifp, &ip6->ip6_dst); if (inm == NULL) { IP6STAT_INC(ip6s_notmember); in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); goto freeit; } } /* Calculate the checksum. */ icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); code = icmp6->icmp6_code; if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) { nd6log((LOG_ERR, "ICMP6 checksum error(%d|%x) %s\n", icmp6->icmp6_type, sum, ip6_sprintf(ip6bufs, &ip6->ip6_src))); ICMP6STAT_INC(icp6s_checksum); goto freeit; } ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]); icmp6_ifstat_inc(ifp, ifs6_in_msg); if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) icmp6_ifstat_inc(ifp, ifs6_in_error); ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); switch (icmp6->icmp6_type) { case ICMP6_DST_UNREACH: icmp6_ifstat_inc(ifp, ifs6_in_dstunreach); switch (code) { case ICMP6_DST_UNREACH_ADMIN: icmp6_ifstat_inc(ifp, ifs6_in_adminprohib); case ICMP6_DST_UNREACH_NOROUTE: case ICMP6_DST_UNREACH_ADDR: case ICMP6_DST_UNREACH_BEYONDSCOPE: case ICMP6_DST_UNREACH_NOPORT: goto deliver; default: goto badcode; } case ICMP6_PACKET_TOO_BIG: icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig); /* * Validation is made in icmp6_mtudisc_update. * Updating the path MTU will be done after examining * intermediate extension headers. */ goto deliver; case ICMP6_TIME_EXCEEDED: icmp6_ifstat_inc(ifp, ifs6_in_timeexceed); switch (code) { case ICMP6_TIME_EXCEED_TRANSIT: case ICMP6_TIME_EXCEED_REASSEMBLY: goto deliver; default: goto badcode; } case ICMP6_PARAM_PROB: icmp6_ifstat_inc(ifp, ifs6_in_paramprob); switch (code) { case ICMP6_PARAMPROB_NEXTHEADER: case ICMP6_PARAMPROB_HEADER: case ICMP6_PARAMPROB_OPTION: goto deliver; default: goto badcode; } case ICMP6_ECHO_REQUEST: icmp6_ifstat_inc(ifp, ifs6_in_echo); if (code != 0) goto badcode; if (icmp6_ratelimit(&ip6->ip6_src, ICMP6_ECHO_REPLY, 0)) break; if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) { /* Give up remote */ break; } if (!M_WRITABLE(n) || n->m_len < off + sizeof(struct icmp6_hdr)) { struct mbuf *n0 = n; int n0len; CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN); n = m_gethdr(M_NOWAIT, n0->m_type); if (n == NULL) { /* Give up remote */ m_freem(n0); break; } m_move_pkthdr(n, n0); /* FIB copied. */ n0len = n0->m_pkthdr.len; /* save for use below */ /* * 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); /* new mbuf contains only ipv6+icmpv6 headers */ 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)); /* recalculate complete packet size */ n->m_pkthdr.len = n0len + (noff - off); n->m_next = n0; } else { if (n->m_len < off + sizeof(*nicmp6)) { n = m_pullup(n, off + sizeof(*nicmp6)); if (n == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); break; } } nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off); noff = off; } if (n) { nicmp6->icmp6_type = ICMP6_ECHO_REPLY; nicmp6->icmp6_code = 0; ICMP6STAT_INC(icp6s_reflect); ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]); icmp6_reflect(n, noff); } break; case ICMP6_ECHO_REPLY: icmp6_ifstat_inc(ifp, ifs6_in_echoreply); if (code != 0) goto badcode; break; case MLD_LISTENER_QUERY: case MLD_LISTENER_REPORT: case MLD_LISTENER_DONE: case MLDV2_LISTENER_REPORT: /* * Drop MLD traffic which is not link-local, has a hop limit * of greater than 1 hop, or which does not have the * IPv6 HBH Router Alert option. * As IPv6 HBH options are stripped in ip6_input() we must * check an mbuf header flag. * XXX Should we also sanity check that these messages * were directed to a link-local multicast prefix? */ if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0) goto freeit; if (mld_input(&m, off, icmp6len) != 0) { *mp = NULL; return (IPPROTO_DONE); } /* m stays. */ break; case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */ { enum { WRU, FQDN } mode; struct prison *pr; if (!V_icmp6_nodeinfo) break; if (icmp6len == sizeof(struct icmp6_hdr) + 4) mode = WRU; else if (icmp6len >= sizeof(struct icmp6_nodeinfo)) mode = FQDN; else goto badlen; pr = NULL; sx_slock(&allprison_lock); TAILQ_FOREACH(pr, &allprison, pr_list) if (pr->pr_vnet == ifp->if_vnet) break; sx_sunlock(&allprison_lock); if (pr == NULL) pr = curthread->td_ucred->cr_prison; if (mode == FQDN) { if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) { m = m_pullup(m, off + sizeof(struct icmp6_nodeinfo)); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); *mp = m; return (IPPROTO_DONE); } } n = m_copym(m, 0, M_COPYALL, M_NOWAIT); if (n) n = ni6_input(n, off, pr); /* XXX meaningless if n == NULL */ noff = sizeof(struct ip6_hdr); } else { u_char *p; int maxhlen, hlen; /* * XXX: this combination of flags is pointless, * but should we keep this for compatibility? */ if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) != (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK)) break; if (code != 0) goto badcode; CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN); n = m_gethdr(M_NOWAIT, m->m_type); if (n == NULL) { /* Give up remote */ break; } if (!m_dup_pkthdr(n, m, M_NOWAIT)) { /* * Previous code did a blind M_COPY_PKTHDR * and said "just for rcvif". If true, then * we could tolerate the dup failing (due to * the deep copy of the tag chain). For now * be conservative and just fail. */ m_free(n); n = NULL; break; } /* * 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); maxhlen = M_TRAILINGSPACE(n) - (sizeof(*nip6) + sizeof(*nicmp6) + 4); mtx_lock(&pr->pr_mtx); hlen = strlen(pr->pr_hostname); if (maxhlen > hlen) maxhlen = hlen; /* meaningless TTL */ bcopy(pr->pr_hostname, p + 4, maxhlen); mtx_unlock(&pr->pr_mtx); noff = sizeof(struct ip6_hdr); 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; } if (n) { ICMP6STAT_INC(icp6s_reflect); ICMP6STAT_INC(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(ifp, ifs6_in_routersolicit); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_router_solicit)) goto badlen; if (send_sendso_input_hook != NULL) { if (m->m_len < off + icmp6len) { m = m_pullup(m, off + icmp6len); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); *mp = NULL; return (IPPROTO_DONE); } } error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); if (error == 0) { m = NULL; goto freeit; } } n = m_copym(m, 0, M_COPYALL, M_NOWAIT); nd6_rs_input(m, off, icmp6len); m = n; if (m == NULL) goto freeit; break; case ND_ROUTER_ADVERT: icmp6_ifstat_inc(ifp, ifs6_in_routeradvert); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_router_advert)) goto badlen; if (send_sendso_input_hook != NULL) { error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); if (error == 0) { m = NULL; goto freeit; } } n = m_copym(m, 0, M_COPYALL, M_NOWAIT); nd6_ra_input(m, off, icmp6len); m = n; if (m == NULL) goto freeit; break; case ND_NEIGHBOR_SOLICIT: icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_neighbor_solicit)) goto badlen; if (send_sendso_input_hook != NULL) { error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); if (error == 0) { m = NULL; goto freeit; } } n = m_copym(m, 0, M_COPYALL, M_NOWAIT); nd6_ns_input(m, off, icmp6len); m = n; if (m == NULL) goto freeit; break; case ND_NEIGHBOR_ADVERT: icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_neighbor_advert)) goto badlen; if (send_sendso_input_hook != NULL) { error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); if (error == 0) { m = NULL; goto freeit; } } n = m_copym(m, 0, M_COPYALL, M_NOWAIT); nd6_na_input(m, off, icmp6len); m = n; if (m == NULL) goto freeit; break; case ND_REDIRECT: icmp6_ifstat_inc(ifp, ifs6_in_redirect); if (code != 0) goto badcode; if (icmp6len < sizeof(struct nd_redirect)) goto badlen; if (send_sendso_input_hook != NULL) { error = send_sendso_input_hook(m, ifp, SND_IN, ip6len); if (error == 0) { m = NULL; goto freeit; } } n = m_copym(m, 0, M_COPYALL, M_NOWAIT); icmp6_redirect_input(m, off); m = n; if (m == NULL) goto freeit; break; case ICMP6_ROUTER_RENUMBERING: if (code != ICMP6_ROUTER_RENUMBERING_COMMAND && code != ICMP6_ROUTER_RENUMBERING_RESULT) goto badcode; if (icmp6len < sizeof(struct icmp6_router_renum)) goto badlen; break; default: nd6log((LOG_DEBUG, "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n", icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src), ip6_sprintf(ip6bufd, &ip6->ip6_dst), ifp ? ifp->if_index : 0)); if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) { /* ICMPv6 error: MUST deliver it by spec... */ goto deliver; } else { /* ICMPv6 informational: MUST not deliver */ break; } deliver: if (icmp6_notify_error(&m, off, icmp6len) != 0) { /* In this case, m should've been freed. */ *mp = NULL; return (IPPROTO_DONE); } break; badcode: ICMP6STAT_INC(icp6s_badcode); break; badlen: ICMP6STAT_INC(icp6s_badlen); break; } /* deliver the packet to appropriate sockets */ icmp6_rip6_input(&m, *offp); *mp = m; return (IPPROTO_DONE); freeit: m_freem(m); *mp = NULL; return (IPPROTO_DONE); } static int icmp6_notify_error(struct mbuf **mp, int off, int icmp6len) { struct mbuf *m; struct icmp6_hdr *icmp6; struct ip6_hdr *eip6; u_int32_t notifymtu; struct sockaddr_in6 icmp6src, icmp6dst; m = *mp; if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) { ICMP6STAT_INC(icp6s_tooshort); goto freeit; } if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) { m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr)); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); *mp = m; return (-1); } } icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); eip6 = (struct ip6_hdr *)(icmp6 + 1); bzero(&icmp6dst, sizeof(icmp6dst)); /* Detect the upper level protocol */ { u_int8_t nxt = eip6->ip6_nxt; int eoff = off + sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr); struct ip6ctlparam ip6cp; 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: if (m->m_len < eoff + sizeof(struct ip6_ext)) { m = m_pullup(m, eoff + sizeof(struct ip6_ext)); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); *mp = m; return (-1); } } eh = (struct ip6_ext *) (mtod(m, caddr_t) + eoff); 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). */ if (m->m_len < eoff + sizeof(*rth)) { m = m_pullup(m, eoff + sizeof(*rth)); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); *mp = m; return (-1); } } rth = (struct ip6_rthdr *) (mtod(m, caddr_t) + eoff); 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; if (m->m_len < eoff + rthlen) { m = m_pullup(m, eoff + rthlen); if (m == NULL) { IP6STAT_INC( ip6s_exthdrtoolong); *mp = m; return (-1); } } rth0 = (struct ip6_rthdr0 *) (mtod(m, caddr_t) + eoff); /* just ignore a bogus header */ if ((rth0->ip6r0_len % 2) == 0 && (hops = rth0->ip6r0_len/2)) icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1)); } eoff += rthlen; nxt = rth->ip6r_nxt; break; case IPPROTO_FRAGMENT: if (m->m_len < eoff + sizeof(struct ip6_frag)) { m = m_pullup(m, eoff + sizeof(struct ip6_frag)); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); *mp = m; return (-1); } } fh = (struct ip6_frag *)(mtod(m, caddr_t) + eoff); /* * 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: icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off); /* * retrieve parameters from the inner IPv6 header, and convert * them into sockaddr structures. * XXX: there is no guarantee that the source or destination * addresses of the inner packet are in the same scope as * the addresses of the icmp packet. But there is no other * way to determine the zone. */ eip6 = (struct ip6_hdr *)(icmp6 + 1); /* * Protocol layers can't do anything useful with unspecified * addresses. */ if (IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_src) || IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_dst)) goto freeit; icmp6dst.sin6_len = sizeof(struct sockaddr_in6); icmp6dst.sin6_family = AF_INET6; if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr)) icmp6dst.sin6_addr = eip6->ip6_dst; if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) goto freeit; bzero(&icmp6src, sizeof(icmp6src)); icmp6src.sin6_len = sizeof(struct sockaddr_in6); icmp6src.sin6_family = AF_INET6; icmp6src.sin6_addr = eip6->ip6_src; if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) goto freeit; icmp6src.sin6_flowinfo = (eip6->ip6_flow & IPV6_FLOWLABEL_MASK); ip6cp.ip6c_m = m; ip6cp.ip6c_icmp6 = icmp6; ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1); ip6cp.ip6c_off = eoff; ip6cp.ip6c_finaldst = &icmp6dst; ip6cp.ip6c_src = &icmp6src; ip6cp.ip6c_nxt = nxt; if (icmp6type == ICMP6_PACKET_TOO_BIG) { notifymtu = ntohl(icmp6->icmp6_mtu); ip6cp.ip6c_cmdarg = (void *)¬ifymtu; icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/ } if (ip6_ctlprotox[nxt] != NULL) ip6_ctlprotox[nxt](&ip6cp); } *mp = m; return (0); freeit: m_freem(m); *mp = NULL; return (-1); } void icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated) { struct in6_addr *dst = &ip6cp->ip6c_finaldst->sin6_addr; 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 in_conninfo inc; uint32_t max_mtu; #if 0 /* * RFC2460 section 5, last paragraph. * even though minimum link MTU for IPv6 is IPV6_MMTU, * we may see ICMPv6 too big with mtu < IPV6_MMTU * due to packet translator in the middle. * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for * special handling. */ if (mtu < IPV6_MMTU) return; #endif /* * we reject ICMPv6 too big with abnormally small value. * XXX what is the good definition of "abnormally small"? */ if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) return; if (!validated) return; /* * In case the suggested mtu is less than IPV6_MMTU, we * only need to remember that it was for above mentioned * "alwaysfrag" case. * Try to be as close to the spec as possible. */ if (mtu < IPV6_MMTU) mtu = IPV6_MMTU - 8; bzero(&inc, sizeof(inc)); inc.inc_fibnum = M_GETFIB(m); inc.inc_flags |= INC_ISIPV6; inc.inc6_faddr = *dst; if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL)) return; max_mtu = tcp_hc_getmtu(&inc); if (max_mtu == 0) max_mtu = tcp_maxmtu6(&inc, NULL); if (mtu < max_mtu) { tcp_hc_updatemtu(&inc, mtu); ICMP6STAT_INC(icp6s_pmtuchg); } } /* * Process a Node Information Query packet, based on * draft-ietf-ipngwg-icmp-name-lookups-07. * * Spec incompatibilities: * - IPv6 Subject address handling * - IPv4 Subject address handling support missing * - Proxy reply (answer even if it's not for me) * - joins NI group address at in6_ifattach() time only, does not cope * with hostname changes by sethostname(3) */ static struct mbuf * ni6_input(struct mbuf *m, int off, struct prison *pr) { struct icmp6_nodeinfo *ni6, *nni6; struct mbuf *n = NULL; u_int16_t qtype; int subjlen; int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); struct ni_reply_fqdn *fqdn; int addrs; /* for NI_QTYPE_NODEADDR */ struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */ struct in6_addr in6_subj; /* subject address */ struct ip6_hdr *ip6; int oldfqdn = 0; /* if 1, return pascal string (03 draft) */ char *subj = NULL; struct in6_ifaddr *ia6 = NULL; ip6 = mtod(m, struct ip6_hdr *); ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); /* * Validate IPv6 source address. * The default configuration MUST be to refuse answering queries from * global-scope addresses according to RFC4602. * Notes: * - it's not very clear what "refuse" means; this implementation * simply drops it. * - it's not very easy to identify global-scope (unicast) addresses * since there are many prefixes for them. It should be safer * and in practice sufficient to check "all" but loopback and * link-local (note that site-local unicast was deprecated and * ULA is defined as global scope-wise) */ if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 && !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) && !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) goto bad; /* * Validate IPv6 destination address. * * The Responder must discard the Query without further processing * unless it is one of the Responder's unicast or anycast addresses, or * a link-local scope multicast address which the Responder has joined. * [RFC4602, Section 5.] */ if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) goto bad; /* else it's a link-local multicast, fine */ } else { /* unicast or anycast */ ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); if (ia6 == NULL) goto bad; /* XXX impossible */ if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) && !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) { nd6log((LOG_DEBUG, "ni6_input: ignore node info to " "a temporary address in %s:%d", __FILE__, __LINE__)); goto bad; } } /* validate query Subject field. */ qtype = ntohs(ni6->ni_qtype); subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo); switch (qtype) { case NI_QTYPE_NOOP: case NI_QTYPE_SUPTYPES: /* 07 draft */ if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) break; /* FALLTHROUGH */ case NI_QTYPE_FQDN: case NI_QTYPE_NODEADDR: case NI_QTYPE_IPV4ADDR: switch (ni6->ni_code) { case ICMP6_NI_SUBJ_IPV6: #if ICMP6_NI_SUBJ_IPV6 != 0 case 0: #endif /* * backward compatibility - try to accept 03 draft * format, where no Subject is present. */ if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 && subjlen == 0) { oldfqdn++; break; } #if ICMP6_NI_SUBJ_IPV6 != 0 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) goto bad; #endif if (subjlen != sizeof(struct in6_addr)) goto bad; /* * Validate Subject address. * * Not sure what exactly "address belongs to the node" * means in the spec, is it just unicast, or what? * * At this moment we consider Subject address as * "belong to the node" if the Subject address equals * to the IPv6 destination address; validation for * IPv6 destination address should have done enough * check for us. * * We do not do proxy at this moment. */ m_copydata(m, off + sizeof(struct icmp6_nodeinfo), subjlen, (caddr_t)&in6_subj); if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL)) goto bad; subj = (char *)&in6_subj; if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj)) break; /* * XXX if we are to allow other cases, we should really * be careful about scope here. * basically, we should disallow queries toward IPv6 * destination X with subject Y, * if scope(X) > scope(Y). * if we allow scope(X) > scope(Y), it will result in * information leakage across scope boundary. */ goto bad; case ICMP6_NI_SUBJ_FQDN: /* * Validate Subject name with gethostname(3). * * The behavior may need some debate, since: * - we are not sure if the node has FQDN as * hostname (returned by gethostname(3)). * - the code does wildcard match for truncated names. * however, we are not sure if we want to perform * wildcard match, if gethostname(3) side has * truncated hostname. */ mtx_lock(&pr->pr_mtx); n = ni6_nametodns(pr->pr_hostname, strlen(pr->pr_hostname), 0); mtx_unlock(&pr->pr_mtx); if (!n || n->m_next || n->m_len == 0) goto bad; if (m->m_len < off + sizeof(struct icmp6_nodeinfo) + subjlen) { m = m_pullup(m, off + sizeof(struct icmp6_nodeinfo) + subjlen); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); goto bad; } } /* ip6 possibly invalid but not used after. */ ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off); subj = (char *)(mtod(m, caddr_t) + off + sizeof(struct icmp6_nodeinfo)); if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *), n->m_len)) { goto bad; } m_freem(n); n = NULL; break; case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */ default: goto bad; } break; } /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */ switch (qtype) { case NI_QTYPE_FQDN: if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) goto bad; break; case NI_QTYPE_NODEADDR: case NI_QTYPE_IPV4ADDR: if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) goto bad; break; } /* guess reply length */ switch (qtype) { case NI_QTYPE_NOOP: break; /* no reply data */ case NI_QTYPE_SUPTYPES: replylen += sizeof(u_int32_t); break; case NI_QTYPE_FQDN: /* XXX will append an mbuf */ replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); break; case NI_QTYPE_NODEADDR: addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj); if ((replylen += addrs * (sizeof(struct in6_addr) + sizeof(u_int32_t))) > MCLBYTES) replylen = MCLBYTES; /* XXX: will truncate pkt later */ break; case NI_QTYPE_IPV4ADDR: /* unsupported - should respond with unknown Qtype? */ 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; /* XXX will append an mbuf */ replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen); oldfqdn++; break; } /* Allocate an mbuf to reply. */ if (replylen > MCLBYTES) { /* * XXX: should we try to allocate more? But MCLBYTES * is probably much larger than IPV6_MMTU... */ goto bad; } if (replylen > MHLEN) n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR); else n = m_gethdr(M_NOWAIT, m->m_type); if (n == NULL) { m_freem(m); return (NULL); } m_move_pkthdr(n, m); /* just for recvif and FIB */ 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_code = ICMP6_NI_SUCCESS; nni6->ni_flags = 0; break; case NI_QTYPE_SUPTYPES: { u_int32_t v; nni6->ni_code = ICMP6_NI_SUCCESS; nni6->ni_flags = htons(0x0000); /* raw bitmap */ /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */ v = (u_int32_t)htonl(0x0000000f); bcopy(&v, nni6 + 1, sizeof(u_int32_t)); break; } case NI_QTYPE_FQDN: nni6->ni_code = ICMP6_NI_SUCCESS; fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) + sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo)); nni6->ni_flags = 0; /* XXX: meaningless TTL */ fqdn->ni_fqdn_ttl = 0; /* ditto. */ /* * XXX do we really have FQDN in hostname? */ mtx_lock(&pr->pr_mtx); n->m_next = ni6_nametodns(pr->pr_hostname, strlen(pr->pr_hostname), oldfqdn); mtx_unlock(&pr->pr_mtx); if (n->m_next == NULL) goto bad; /* XXX we assume that n->m_next is not a chain */ if (n->m_next->m_next != NULL) goto bad; n->m_pkthdr.len += n->m_next->m_len; break; case NI_QTYPE_NODEADDR: { int lenlim, copied; nni6->ni_code = ICMP6_NI_SUCCESS; n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo); lenlim = M_TRAILINGSPACE(n); copied = ni6_store_addrs(ni6, nni6, ifp, lenlim); /* XXX: reset mbuf length */ n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo) + copied; break; } default: break; /* XXX impossible! */ } nni6->ni_type = ICMP6_NI_REPLY; m_freem(m); return (n); bad: m_freem(m); if (n) m_freem(n); return (NULL); } /* * make a mbuf with DNS-encoded string. no compression support. * * XXX names with less than 2 dots (like "foo" or "foo.section") will be * treated as truncated name (two \0 at the end). this is a wild guess. * * old - return pascal string if non-zero */ static struct mbuf * ni6_nametodns(const char *name, int namelen, int old) { struct mbuf *m; char *cp, *ep; const char *p, *q; int i, len, nterm; if (old) len = namelen + 1; else len = MCLBYTES; /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */ if (len > MLEN) m = m_getcl(M_NOWAIT, MT_DATA, 0); else m = m_get(M_NOWAIT, MT_DATA); if (m == NULL) goto fail; if (old) { m->m_len = len; *mtod(m, char *) = namelen; bcopy(name, mtod(m, char *) + 1, namelen); return m; } else { m->m_len = 0; cp = mtod(m, char *); ep = mtod(m, char *) + M_TRAILINGSPACE(m); /* if not certain about my name, return empty buffer */ if (namelen == 0) return m; /* * guess if it looks like shortened hostname, or FQDN. * shortened hostname needs two trailing "\0". */ i = 0; for (p = name; p < name + namelen; p++) { if (*p && *p == '.') i++; } if (i < 2) nterm = 2; else nterm = 1; p = name; while (cp < ep && p < name + namelen) { i = 0; for (q = p; q < name + namelen && *q && *q != '.'; q++) i++; /* result does not fit into mbuf */ if (cp + i + 1 >= ep) goto fail; /* * DNS label length restriction, RFC1035 page 8. * "i == 0" case is included here to avoid returning * 0-length label on "foo..bar". */ if (i <= 0 || i >= 64) goto fail; *cp++ = i; bcopy(p, cp, i); cp += i; p = q; if (p < name + namelen && *p == '.') p++; } /* termination */ if (cp + nterm >= ep) goto fail; while (nterm-- > 0) *cp++ = '\0'; m->m_len = cp - mtod(m, char *); return m; } panic("should not reach here"); /* NOTREACHED */ fail: if (m) m_freem(m); return NULL; } /* * check if two DNS-encoded string matches. takes care of truncated * form (with \0\0 at the end). no compression support. * XXX upper/lowercase match (see RFC2065) */ static int ni6_dnsmatch(const char *a, int alen, const char *b, int blen) { const char *a0, *b0; int l; /* simplest case - need validation? */ if (alen == blen && bcmp(a, b, alen) == 0) return 1; a0 = a; b0 = b; /* termination is mandatory */ if (alen < 2 || blen < 2) return 0; if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') return 0; alen--; blen--; while (a - a0 < alen && b - b0 < blen) { if (a - a0 + 1 > alen || b - b0 + 1 > blen) return 0; if ((signed char)a[0] < 0 || (signed char)b[0] < 0) return 0; /* we don't support compression yet */ if (a[0] >= 64 || b[0] >= 64) return 0; /* truncated case */ if (a[0] == 0 && a - a0 == alen - 1) return 1; if (b[0] == 0 && b - b0 == blen - 1) return 1; if (a[0] == 0 || b[0] == 0) return 0; if (a[0] != b[0]) return 0; l = a[0]; if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) return 0; if (bcmp(a + 1, b + 1, l) != 0) return 0; a += 1 + l; b += 1 + l; } if (a - a0 == alen && b - b0 == blen) return 1; else return 0; } /* * calculate the number of addresses to be returned in the node info reply. */ static int ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp, struct in6_addr *subj) { struct ifnet *ifp; struct in6_ifaddr *ifa6; struct ifaddr *ifa; int addrs = 0, addrsofif, iffound = 0; int niflags = ni6->ni_flags; NET_EPOCH_ASSERT(); if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) { switch (ni6->ni_code) { case ICMP6_NI_SUBJ_IPV6: if (subj == NULL) /* must be impossible... */ return (0); break; default: /* * XXX: we only support IPv6 subject address for * this Qtype. */ return (0); } } CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { addrsofif = 0; CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ifa6 = (struct in6_ifaddr *)ifa; if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 && IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr)) iffound = 1; /* * IPv4-mapped addresses can only be returned by a * Node Information proxy, since they represent * addresses of IPv4-only nodes, which perforce do * not implement this protocol. * [icmp-name-lookups-07, Section 5.4] * So we don't support NI_NODEADDR_FLAG_COMPAT in * this function at this moment. */ /* What do we have to do about ::1? */ switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { case IPV6_ADDR_SCOPE_LINKLOCAL: if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) continue; break; case IPV6_ADDR_SCOPE_SITELOCAL: if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) continue; break; case IPV6_ADDR_SCOPE_GLOBAL: if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) continue; break; default: continue; } /* * check if anycast is okay. * XXX: just experimental. not in the spec. */ if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) continue; /* we need only unicast addresses */ if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { continue; } addrsofif++; /* count the address */ } if (iffound) { *ifpp = ifp; return (addrsofif); } addrs += addrsofif; } return (addrs); } static int ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6, struct ifnet *ifp0, int resid) { struct ifnet *ifp; struct in6_ifaddr *ifa6; struct ifaddr *ifa; struct ifnet *ifp_dep = NULL; int copied = 0, allow_deprecated = 0; u_char *cp = (u_char *)(nni6 + 1); int niflags = ni6->ni_flags; u_int32_t ltime; NET_EPOCH_ASSERT(); if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) return (0); /* needless to copy */ ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet); again: for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) { CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ifa6 = (struct in6_ifaddr *)ifa; if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 && allow_deprecated == 0) { /* * prefererred address should be put before * deprecated addresses. */ /* record the interface for later search */ if (ifp_dep == NULL) ifp_dep = ifp; continue; } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 && allow_deprecated != 0) continue; /* we now collect deprecated addrs */ /* What do we have to do about ::1? */ switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) { case IPV6_ADDR_SCOPE_LINKLOCAL: if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) continue; break; case IPV6_ADDR_SCOPE_SITELOCAL: if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) continue; break; case IPV6_ADDR_SCOPE_GLOBAL: if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) continue; break; default: continue; } /* * check if anycast is okay. * XXX: just experimental. not in the spec. */ if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 && (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) continue; if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) { continue; } /* now we can copy the address */ if (resid < sizeof(struct in6_addr) + sizeof(u_int32_t)) { /* * We give up much more copy. * Set the truncate flag and return. */ nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE; return (copied); } /* * Set the TTL of the address. * The TTL value should be one of the following * according to the specification: * * 1. The remaining lifetime of a DHCP lease on the * address, or * 2. The remaining Valid Lifetime of a prefix from * which the address was derived through Stateless * Autoconfiguration. * * Note that we currently do not support stateful * address configuration by DHCPv6, so the former * case can't happen. */ if (ifa6->ia6_lifetime.ia6t_expire == 0) ltime = ND6_INFINITE_LIFETIME; else { if (ifa6->ia6_lifetime.ia6t_expire > time_uptime) ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime); else ltime = 0; } bcopy(<ime, cp, sizeof(u_int32_t)); cp += sizeof(u_int32_t); /* copy the address itself */ bcopy(&ifa6->ia_addr.sin6_addr, cp, sizeof(struct in6_addr)); in6_clearscope((struct in6_addr *)cp); /* XXX */ cp += sizeof(struct in6_addr); resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t)); copied += (sizeof(struct in6_addr) + sizeof(u_int32_t)); } if (ifp0) /* we need search only on the specified IF */ break; } if (allow_deprecated == 0 && ifp_dep != NULL) { ifp = ifp_dep; allow_deprecated = 1; goto again; } return (copied); } static bool icmp6_rip6_match(const struct inpcb *inp, void *v) { struct ip6_hdr *ip6 = v; if ((inp->inp_vflag & INP_IPV6) == 0) return (false); if (inp->inp_ip_p != IPPROTO_ICMPV6) return (false); if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst)) return (false); if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) && !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src)) return (false); return (true); } /* * XXX almost dup'ed code with rip6_input. */ static int icmp6_rip6_input(struct mbuf **mp, int off) { struct mbuf *n, *m = *mp; struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo, INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6); struct inpcb *inp; struct sockaddr_in6 fromsa; struct icmp6_hdr *icmp6; struct mbuf *opts = NULL; int delivered = 0; /* This is assumed to be safe; icmp6_input() does a pullup. */ icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off); /* * XXX: the address may have embedded scope zone ID, which should be * hidden from applications. */ bzero(&fromsa, sizeof(fromsa)); fromsa.sin6_family = AF_INET6; fromsa.sin6_len = sizeof(struct sockaddr_in6); fromsa.sin6_addr = ip6->ip6_src; if (sa6_recoverscope(&fromsa)) { m_freem(m); *mp = NULL; return (IPPROTO_DONE); } while ((inp = inp_next(&inpi)) != NULL) { if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type, inp->in6p_icmp6filt)) continue; /* * Recent network drivers tend to allocate a single * mbuf cluster, rather than to make a couple of * mbufs without clusters. Also, since the IPv6 code * path tries to avoid m_pullup(), it is highly * probable that we still have an mbuf cluster here * even though the necessary length can be stored in an * mbuf's internal buffer. * Meanwhile, the default size of the receive socket * buffer for raw sockets is not so large. This means * the possibility of packet loss is relatively higher * than before. To avoid this scenario, we copy the * received data to a separate mbuf that does not use * a cluster, if possible. * XXX: it is better to copy the data after stripping * intermediate headers. */ if ((m->m_flags & M_EXT) && m->m_next == NULL && m->m_len <= MHLEN) { n = m_get(M_NOWAIT, m->m_type); if (n != NULL) { if (m_dup_pkthdr(n, m, M_NOWAIT)) { bcopy(m->m_data, n->m_data, m->m_len); n->m_len = m->m_len; } else { m_free(n); n = NULL; } } } else n = m_copym(m, 0, M_COPYALL, M_NOWAIT); if (n == NULL) continue; if (inp->inp_flags & INP_CONTROLOPTS) ip6_savecontrol(inp, n, &opts); /* strip intermediate headers */ m_adj(n, off); SOCKBUF_LOCK(&inp->inp_socket->so_rcv); if (sbappendaddr_locked(&inp->inp_socket->so_rcv, (struct sockaddr *)&fromsa, n, opts) == 0) { soroverflow_locked(inp->inp_socket); m_freem(n); if (opts) m_freem(opts); } else { sorwakeup_locked(inp->inp_socket); delivered++; } opts = NULL; } m_freem(m); *mp = NULL; if (delivered == 0) IP6STAT_DEC(ip6s_delivered); return (IPPROTO_DONE); } /* * Reflect the ip6 packet back to the source. * OFF points to the icmp6 header, counted from the top of the mbuf. */ static void icmp6_reflect(struct mbuf *m, size_t off) { struct in6_addr src6, *srcp; struct ip6_hdr *ip6; struct icmp6_hdr *icmp6; struct in6_ifaddr *ia = NULL; struct ifnet *outif = NULL; int plen; int type, code, hlim; /* 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; } } 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. */ hlim = 0; srcp = NULL; /* * If the incoming packet was addressed directly to us (i.e. unicast), * use dst as the src for the reply. * The IN6_IFF_NOTREADY case should be VERY rare, but is possible * (for example) when we encounter an error while forwarding procedure * destined to a duplicated address of ours. */ if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false); if (ia != NULL && !(ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) { src6 = ia->ia_addr.sin6_addr; srcp = &src6; if (m->m_pkthdr.rcvif != NULL) { /* XXX: This may not be the outgoing interface */ hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim; } else hlim = V_ip6_defhlim; } } if (srcp == NULL) { int error; struct in6_addr dst6; uint32_t scopeid; /* * 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. */ in6_splitscope(&ip6->ip6_src, &dst6, &scopeid); error = in6_selectsrc_addr(M_GETFIB(m), &dst6, scopeid, NULL, &src6, &hlim); if (error) { char ip6buf[INET6_ADDRSTRLEN]; nd6log((LOG_DEBUG, "icmp6_reflect: source can't be determined: " "dst=%s, error=%d\n", ip6_sprintf(ip6buf, &ip6->ip6_dst), error)); goto bad; } srcp = &src6; } /* * ip6_input() drops a packet if its src is multicast. * So, the src is never multicast. */ ip6->ip6_dst = ip6->ip6_src; ip6->ip6_src = *srcp; ip6->ip6_flow = 0; ip6->ip6_vfc &= ~IPV6_VERSION_MASK; ip6->ip6_vfc |= IPV6_VERSION; ip6->ip6_nxt = IPPROTO_ICMPV6; ip6->ip6_hlim = hlim; 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); m->m_pkthdr.rcvif = NULL; ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); if (outif) icmp6_ifoutstat_inc(outif, type, code); return; bad: m_freem(m); return; } static const char * icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6, struct in6_addr *tgt6) { static char buf[1024]; char ip6bufs[INET6_ADDRSTRLEN]; char ip6bufd[INET6_ADDRSTRLEN]; char ip6buft[INET6_ADDRSTRLEN]; snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)", ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6), ip6_sprintf(ip6buft, tgt6)); return buf; } void icmp6_redirect_input(struct mbuf *m, int off) { struct ifnet *ifp; struct ip6_hdr *ip6; struct nd_redirect *nd_rd; struct in6_addr src6, redtgt6, reddst6; union nd_opts ndopts; char ip6buf[INET6_ADDRSTRLEN]; char *lladdr; int icmp6len, is_onlink, is_router, lladdrlen; M_ASSERTPKTHDR(m); KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__)); /* XXX if we are router, we don't update route by icmp6 redirect */ if (V_ip6_forwarding) goto freeit; if (!V_icmp6_rediraccept) goto freeit; /* RFC 6980: Nodes MUST silently ignore fragments */ if(m->m_flags & M_FRAGMENTED) goto freeit; ip6 = mtod(m, struct ip6_hdr *); icmp6len = ntohs(ip6->ip6_plen); if (m->m_len < off + icmp6len) { m = m_pullup(m, off + icmp6len); if (m == NULL) { IP6STAT_INC(ip6s_exthdrtoolong); return; } } ip6 = mtod(m, struct ip6_hdr *); nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off); ifp = m->m_pkthdr.rcvif; redtgt6 = nd_rd->nd_rd_target; reddst6 = nd_rd->nd_rd_dst; if (in6_setscope(&redtgt6, ifp, NULL) || in6_setscope(&reddst6, ifp, NULL)) { goto freeit; } /* validation */ src6 = ip6->ip6_src; if (!IN6_IS_ADDR_LINKLOCAL(&src6)) { nd6log((LOG_ERR, "ICMP6 redirect sent from %s rejected; " "must be from linklocal\n", ip6_sprintf(ip6buf, &src6))); goto bad; } if (__predict_false(ip6->ip6_hlim != 255)) { ICMP6STAT_INC(icp6s_invlhlim); nd6log((LOG_ERR, "ICMP6 redirect sent from %s rejected; " "hlim=%d (must be 255)\n", ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim)); goto bad; } { /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */ struct nhop_object *nh; struct in6_addr kdst; uint32_t scopeid; in6_splitscope(&reddst6, &kdst, &scopeid); NET_EPOCH_ASSERT(); nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0); if (nh != NULL) { struct in6_addr nh_addr; nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr; if ((nh->nh_flags & NHF_GATEWAY) == 0) { nd6log((LOG_ERR, "ICMP6 redirect rejected; no route " "with inet6 gateway found for redirect dst: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); goto bad; } /* * Embed scope zone id into next hop address. */ nh_addr = nh->gw6_sa.sin6_addr; if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) { nd6log((LOG_ERR, "ICMP6 redirect rejected; " "not equal to gw-for-src=%s (must be same): " "%s\n", ip6_sprintf(ip6buf, &nh_addr), icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); 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; } } if (IN6_IS_ADDR_MULTICAST(&reddst6)) { nd6log((LOG_ERR, "ICMP6 redirect rejected; " "redirect dst must be unicast: %s\n", icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); goto bad; } is_router = is_onlink = 0; if (IN6_IS_ADDR_LINKLOCAL(&redtgt6)) is_router = 1; /* router case */ if (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; } icmp6len -= sizeof(*nd_rd); nd6_option_init(nd_rd + 1, icmp6len, &ndopts); if (nd6_options(&ndopts) < 0) { nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n", __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); /* nd6_options have incremented stats */ goto freeit; } lladdr = NULL; lladdrlen = 0; 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, "%s: lladdrlen mismatch for %s " "(if %d, icmp6 packet %d): %s\n", __func__, ip6_sprintf(ip6buf, &redtgt6), ifp->if_addrlen, lladdrlen - 2, icmp6_redirect_diag(&src6, &reddst6, &redtgt6))); goto bad; } /* Validation passed. */ /* RFC 2461 8.3 */ nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT, is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER); /* * Install a gateway route in the better-router case or an interface * route in the on-link-destination case. */ { struct sockaddr_in6 sdst; struct sockaddr_in6 sgw; struct sockaddr_in6 ssrc; struct sockaddr *gw; int rt_flags; u_int fibnum; bzero(&sdst, sizeof(sdst)); bzero(&ssrc, sizeof(ssrc)); sdst.sin6_family = ssrc.sin6_family = AF_INET6; sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6); bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr)); bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr)); rt_flags = 0; if (is_router) { bzero(&sgw, sizeof(sgw)); sgw.sin6_family = AF_INET6; sgw.sin6_len = sizeof(struct sockaddr_in6); bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr)); gw = (struct sockaddr *)&sgw; rt_flags |= RTF_GATEWAY; } else gw = ifp->if_addr->ifa_addr; for (fibnum = 0; fibnum < rt_numfibs; fibnum++) rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw, (struct sockaddr *)&ssrc, ifp, rt_flags, V_icmp6_redirtimeout); } freeit: m_freem(m); return; bad: ICMP6STAT_INC(icp6s_badredirect); m_freem(m); } void icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh) { 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 m_tag *mtag; struct ip6_hdr *ip6; /* m as struct ip6_hdr */ struct nd_redirect *nd_rd; struct llentry *ln = NULL; size_t maxlen; u_char *p; struct ifnet *outif = NULL; struct sockaddr_in6 src_sa; icmp6_errcount(ND_REDIRECT, 0); /* if we are not router, we don't send icmp6 redirect */ if (!V_ip6_forwarding) goto fail; /* sanity check */ if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_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 *); 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; 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 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); if (m == NULL) goto fail; M_SETFIB(m, M_GETFIB(m0)); maxlen = M_TRAILINGSPACE(m); maxlen = min(IPV6_MMTU, maxlen); /* just for safety */ if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) + ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) { goto fail; } { /* get ip6 linklocal address for ifp(my outgoing interface). */ struct in6_ifaddr *ia; if ((ia = in6ifa_ifpforlinklocal(ifp, IN6_IFF_NOTREADY| IN6_IFF_ANYCAST)) == NULL) goto fail; ifp_ll6 = &ia->ia_addr.sin6_addr; /* XXXRW: reference released prematurely. */ ifa_free(&ia->ia_ifa); } /* get ip6 linklocal address for the router. */ if (nh->nh_flags & NHF_GATEWAY) { struct sockaddr_in6 *sin6; sin6 = &nh->gw6_sa; 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 (nh->nh_flags & NHF_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 */ int len; struct nd_opt_hdr *nd_opt; char *lladdr; ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6, 0), ifp); if (ln == NULL) 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 (ln->la_flags & LLE_VALID) { 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(ln->ll_addr, lladdr, ifp->if_addrlen); p += len; } } nolladdropt: if (ln != NULL) LLE_RUNLOCK(ln); m->m_pkthdr.len = m->m_len = p - (u_char *)ip6; /* just to be safe */ #ifdef M_DECRYPTED /*not openbsd*/ if (m0->m_flags & M_DECRYPTED) goto noredhdropt; #endif 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; /* 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", __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_tag_delete_chain(m0, NULL); m0->m_flags &= ~M_PKTHDR; m->m_next = m0; m->m_pkthdr.len = m->m_len + m0->m_len; m0 = NULL; } noredhdropt:; if (m0) { m_freem(m0); m0 = NULL; } /* XXX: clear embedded link IDs in the inner header */ in6_clearscope(&sip6->ip6_src); in6_clearscope(&sip6->ip6_dst); in6_clearscope(&nd_rd->nd_rd_target); in6_clearscope(&nd_rd->nd_rd_dst); ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr)); nd_rd->nd_rd_cksum = 0; nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen)); if (send_sendso_input_hook != NULL) { mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short), M_NOWAIT); if (mtag == NULL) goto fail; *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type; m_tag_prepend(m, mtag); } /* send the packet to outside... */ ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL); if (outif) { icmp6_ifstat_inc(outif, ifs6_out_msg); icmp6_ifstat_inc(outif, ifs6_out_redirect); } ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]); return; fail: if (m) m_freem(m); if (m0) m_freem(m0); } /* * ICMPv6 socket option processing. */ int icmp6_ctloutput(struct socket *so, struct sockopt *sopt) { int error = 0; int optlen; struct inpcb *inp = sotoinpcb(so); int level, op, optname; if (sopt) { level = sopt->sopt_level; op = sopt->sopt_dir; optname = sopt->sopt_name; optlen = sopt->sopt_valsize; } else level = op = optname = optlen = 0; if (level != IPPROTO_ICMPV6) { return EINVAL; } switch (op) { case PRCO_SETOPT: switch (optname) { case ICMP6_FILTER: { struct icmp6_filter ic6f; if (optlen != sizeof(ic6f)) { error = EMSGSIZE; break; } error = sooptcopyin(sopt, &ic6f, optlen, optlen); if (error == 0) { INP_WLOCK(inp); *inp->in6p_icmp6filt = ic6f; INP_WUNLOCK(inp); } break; } default: error = ENOPROTOOPT; break; } break; case PRCO_GETOPT: switch (optname) { case ICMP6_FILTER: { struct icmp6_filter ic6f; INP_RLOCK(inp); ic6f = *inp->in6p_icmp6filt; INP_RUNLOCK(inp); error = sooptcopyout(sopt, &ic6f, sizeof(ic6f)); break; } default: error = ENOPROTOOPT; break; } break; } return (error); } +static int sysctl_icmp6lim_and_jitter(SYSCTL_HANDLER_ARGS); +VNET_DEFINE_STATIC(u_int, icmp6errppslim) = 100; +#define V_icmp6errppslim VNET(icmp6errppslim) +SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ERRPPSLIMIT, errppslimit, + CTLTYPE_UINT | CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6errppslim), 0, + &sysctl_icmp6lim_and_jitter, "IU", + "Maximum number of ICMPv6 error/reply messages per second"); + +VNET_DEFINE_STATIC(int, icmp6lim_curr_jitter) = 0; +#define V_icmp6lim_curr_jitter VNET(icmp6lim_curr_jitter) + +VNET_DEFINE_STATIC(u_int, icmp6lim_jitter) = 8; +#define V_icmp6lim_jitter VNET(icmp6lim_jitter) +SYSCTL_PROC(_net_inet6_icmp6, OID_AUTO, icmp6lim_jitter, CTLTYPE_UINT | + CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6lim_jitter), 0, + &sysctl_icmp6lim_and_jitter, "IU", + "Random errppslimit jitter adjustment limit"); + +VNET_DEFINE_STATIC(int, icmp6lim_output) = 1; +#define V_icmp6lim_output VNET(icmp6lim_output) +SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, icmp6lim_output, + CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(icmp6lim_output), 0, + "Enable logging of ICMPv6 response rate limiting"); + +typedef enum { + RATELIM_PARAM_PROB = 0, + RATELIM_TOO_BIG, + RATELIM_UNREACH, + RATELIM_TEXCEED, + RATELIM_REDIR, + RATELIM_REPLY, + RATELIM_OTHER, + RATELIM_MAX +} ratelim_which; + +static const char *icmp6_rate_descrs[RATELIM_MAX] = { + [RATELIM_PARAM_PROB] = "bad IPv6 header", + [RATELIM_TOO_BIG] = "packet too big", + [RATELIM_UNREACH] = "destination unreachable", + [RATELIM_TEXCEED] = "time exceeded", + [RATELIM_REPLY] = "echo reply", + [RATELIM_REDIR] = "neighbor discovery redirect", + [RATELIM_OTHER] = "(other)", +}; + +static void +icmp6lim_new_jitter(void) +{ + /* + * Adjust limit +/- to jitter the measurement to deny a side-channel + * port scan as in https://dl.acm.org/doi/10.1145/3372297.3417280 + */ + if (V_icmp6lim_jitter > 0) + V_icmp6lim_curr_jitter = + arc4random_uniform(V_icmp6lim_jitter * 2 + 1) - + V_icmp6lim_jitter; +} + +static int +sysctl_icmp6lim_and_jitter(SYSCTL_HANDLER_ARGS) +{ + uint32_t new; + int error; + bool lim; + + MPASS(oidp->oid_arg1 == &VNET_NAME(icmp6errppslim) || + oidp->oid_arg1 == &VNET_NAME(icmp6lim_jitter)); + + lim = (oidp->oid_arg1 == &VNET_NAME(icmp6errppslim)); + new = lim ? V_icmp6errppslim : V_icmp6lim_jitter; + error = sysctl_handle_int(oidp, &new, 0, req); + if (error == 0 && req->newptr) { + if (lim) { + if (new <= V_icmp6lim_jitter) + error = EINVAL; + else + V_icmp6errppslim = new; + } else { + if (new >= V_icmp6errppslim) + error = EINVAL; + else { + V_icmp6lim_jitter = new; + icmp6lim_new_jitter(); + } + } + } + MPASS(V_icmp6errppslim + V_icmp6lim_curr_jitter > 0); + + return (error); +} + + +VNET_DEFINE_STATIC(struct counter_rate, icmp6_rates[RATELIM_MAX]); +#define V_icmp6_rates VNET(icmp6_rates) + +static void +icmp6_ratelimit_init(void) +{ + + for (int i = 0; i < RATELIM_MAX; i++) { + V_icmp6_rates[i].cr_rate = counter_u64_alloc(M_WAITOK); + V_icmp6_rates[i].cr_ticks = ticks; + } + icmp6lim_new_jitter(); +} +VNET_SYSINIT(icmp6_ratelimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, + icmp6_ratelimit_init, NULL); + +#ifdef VIMAGE +static void +icmp6_ratelimit_uninit(void) +{ + + for (int i = 0; i < RATELIM_MAX; i++) + counter_u64_free(V_icmp6_rates[i].cr_rate); +} +VNET_SYSUNINIT(icmp6_ratelimit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, + icmp6_ratelimit_uninit, NULL); +#endif + /* * 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) +icmp6_ratelimit(const struct in6_addr *dst, const int type, const int code) { - int ret; + ratelim_which which; + int64_t pps; - ret = 0; /* okay to send */ + if (V_icmp6errppslim == 0) + return (0); - /* PPS limit */ - if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count, - V_icmp6errppslim)) { - /* The packet is subject to rate limit */ - ret++; + switch (type) { + case ICMP6_PARAM_PROB: + which = RATELIM_PARAM_PROB; + break; + case ICMP6_PACKET_TOO_BIG: + which = RATELIM_TOO_BIG; + break; + case ICMP6_DST_UNREACH: + which = RATELIM_UNREACH; + break; + case ICMP6_TIME_EXCEEDED: + which = RATELIM_TEXCEED; + break; + case ND_REDIRECT: + which = RATELIM_REDIR; + break; + case ICMP6_ECHO_REPLY: + which = RATELIM_REPLY; + break; + default: + which = RATELIM_OTHER; + break; + }; + + pps = counter_ratecheck(&V_icmp6_rates[which], V_icmp6errppslim + + V_icmp6lim_curr_jitter); + if (pps > 0) { + if (V_icmp6lim_output) + log(LOG_NOTICE, "Limiting ICMPv6 %s output from %jd " + "to %d packets/sec\n", icmp6_rate_descrs[which], + (intmax_t )pps, V_icmp6errppslim + + V_icmp6lim_curr_jitter); + icmp6lim_new_jitter(); + } + if (pps == -1) { ICMP6STAT_INC(icp6s_toofreq); + return (-1); } - return ret; + return (0); }