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IABSD.fr/src/sys/netinet6/ip6_input.c
gnezdo
- sys/netinet6/ip6_input.c
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/* $OpenBSD: ip6_input.c,v 1.229 2020/08/24 16:40:07 gnezdo Exp $ */ /* $KAME: ip6_input.c,v 1.188 2001/03/29 05:34:31 itojun 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_input.c 8.2 (Berkeley) 1/4/94 */ #include "pf.h" #include "carp.h" #include <sys/param.h> #include <sys/systm.h> #include <sys/mbuf.h> #include <sys/domain.h> #include <sys/sysctl.h> #include <sys/protosw.h> #include <sys/socket.h> #include <sys/socketvar.h> #include <sys/errno.h> #include <sys/time.h> #include <sys/timeout.h> #include <sys/kernel.h> #include <sys/syslog.h> #include <sys/task.h> #include <net/if.h> #include <net/if_var.h> #include <net/if_types.h> #include <net/route.h> #include <net/netisr.h> #include <netinet/in.h> #include <netinet/ip.h> #include <netinet/in_pcb.h> #include <netinet/ip_var.h> #include <netinet6/in6_var.h> #include <netinet6/in6_ifattach.h> #include <netinet/ip6.h> #include <netinet6/ip6_var.h> #include <netinet/icmp6.h> #include <netinet6/nd6.h> #include <netinet6/ip6protosw.h> #include "gif.h" #include "bpfilter.h" #ifdef MROUTING #include <netinet6/ip6_mroute.h> #endif #if NPF > 0 #include <net/pfvar.h> #endif #if NCARP > 0 #include <netinet/ip_carp.h> #endif struct cpumem *ip6counters; uint8_t ip6_soiikey[IP6_SOIIKEY_LEN]; int ip6_ours(struct mbuf **, int *, int, int); int ip6_check_rh0hdr(struct mbuf *, int *); int ip6_hbhchcheck(struct mbuf *, int *, int *, int *); int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); int ip6_sysctl_soiikey(void *, size_t *, void *, size_t); static struct mbuf_queue ip6send_mq; static void ip6_send_dispatch(void *); static struct task ip6send_task = TASK_INITIALIZER(ip6_send_dispatch, &ip6send_mq); /* * IP6 initialization: fill in IP6 protocol switch table. * All protocols not implemented in kernel go to raw IP6 protocol handler. */ void ip6_init(void) { const struct protosw *pr; int i; pr = pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); if (pr == NULL) panic("%s", __func__); for (i = 0; i < IPPROTO_MAX; i++) ip6_protox[i] = pr - inet6sw; for (pr = inet6domain.dom_protosw; pr < inet6domain.dom_protoswNPROTOSW; pr++) if (pr->pr_domain->dom_family == PF_INET6 && pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW && pr->pr_protocol < IPPROTO_MAX) ip6_protox[pr->pr_protocol] = pr - inet6sw; ip6_randomid_init(); nd6_init(); frag6_init(); mq_init(&ip6send_mq, 64, IPL_SOFTNET); ip6counters = counters_alloc(ip6s_ncounters); } void ipv6_input(struct ifnet *ifp, struct mbuf *m) { int off, nxt; off = 0; nxt = ip6_input_if(&m, &off, IPPROTO_IPV6, AF_UNSPEC, ifp); KASSERT(nxt == IPPROTO_DONE); } int ip6_input_if(struct mbuf **mp, int *offp, int nxt, int af, struct ifnet *ifp) { struct mbuf *m = *mp; struct ip6_hdr *ip6; struct sockaddr_in6 sin6; struct rtentry *rt = NULL; int ours = 0; u_int16_t src_scope, dst_scope; #if NPF > 0 struct in6_addr odst; #endif int srcrt = 0; KASSERT(*offp == 0); ip6stat_inc(ip6s_total); if (m->m_len < sizeof(struct ip6_hdr)) { if ((m = *mp = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { ip6stat_inc(ip6s_toosmall); goto bad; } } ip6 = mtod(m, struct ip6_hdr *); if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { ip6stat_inc(ip6s_badvers); goto bad; } #if NCARP > 0 if (carp_lsdrop(ifp, m, AF_INET6, ip6->ip6_src.s6_addr32, ip6->ip6_dst.s6_addr32, (ip6->ip6_nxt == IPPROTO_ICMPV6 ? 0 : 1))) goto bad; #endif ip6stat_inc(ip6s_nxthist + ip6->ip6_nxt); /* * Check against address spoofing/corruption. */ if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { /* * XXX: "badscope" is not very suitable for a multicast source. */ ip6stat_inc(ip6s_badscope); goto bad; } if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && (ifp->if_flags & IFF_LOOPBACK) == 0) { ip6stat_inc(ip6s_badscope); goto bad; } /* Drop packets if interface ID portion is already filled. */ if (((IN6_IS_SCOPE_EMBED(&ip6->ip6_src) && ip6->ip6_src.s6_addr16[1]) || (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst) && ip6->ip6_dst.s6_addr16[1])) && (ifp->if_flags & IFF_LOOPBACK) == 0) { ip6stat_inc(ip6s_badscope); goto bad; } if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) && !(m->m_flags & M_LOOP)) { /* * In this case, the packet should come from the loopback * interface. However, we cannot just check the if_flags, * because ip6_mloopback() passes the "actual" interface * as the outgoing/incoming interface. */ ip6stat_inc(ip6s_badscope); goto bad; } /* * The following check is not documented in specs. A malicious * party may be able to use IPv4 mapped addr to confuse tcp/udp stack * and bypass security checks (act as if it was from 127.0.0.1 by using * IPv6 src ::ffff:127.0.0.1). Be cautious. * * This check chokes if we are in an SIIT cloud. As none of BSDs * support IPv4-less kernel compilation, we cannot support SIIT * environment at all. So, it makes more sense for us to reject any * malicious packets for non-SIIT environment, than try to do a * partial support for SIIT environment. */ if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { ip6stat_inc(ip6s_badscope); goto bad; } /* * Reject packets with IPv4 compatible addresses (auto tunnel). * * The code forbids automatic tunneling as per RFC4213. */ if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { ip6stat_inc(ip6s_badscope); goto bad; } /* * If the packet has been received on a loopback interface it * can be destinated to any local address, not necessarily to * an address configured on `ifp'. */ if (ifp->if_flags & IFF_LOOPBACK) { if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) { src_scope = ip6->ip6_src.s6_addr16[1]; ip6->ip6_src.s6_addr16[1] = 0; } if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) { dst_scope = ip6->ip6_dst.s6_addr16[1]; ip6->ip6_dst.s6_addr16[1] = 0; } } #if NPF > 0 /* * Packet filter */ odst = ip6->ip6_dst; if (pf_test(AF_INET6, PF_IN, ifp, mp) != PF_PASS) goto bad; m = *mp; if (m == NULL) goto bad; ip6 = mtod(m, struct ip6_hdr *); srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); #endif /* * Without embedded scope ID we cannot find link-local * addresses in the routing table. */ if (ifp->if_flags & IFF_LOOPBACK) { if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) ip6->ip6_src.s6_addr16[1] = src_scope; if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) ip6->ip6_dst.s6_addr16[1] = dst_scope; } else { if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) ip6->ip6_src.s6_addr16[1] = htons(ifp->if_index); if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); } /* * Be more secure than RFC5095 and scan for type 0 routing headers. * If pf has already scanned the header chain, do not do it twice. */ if (!(m->m_pkthdr.pf.flags & PF_TAG_PROCESSED) && ip6_check_rh0hdr(m, offp)) { ip6stat_inc(ip6s_badoptions); icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, *offp); m = *mp = NULL; goto bad; } #if NPF > 0 if (pf_ouraddr(m) == 1) { nxt = ip6_ours(mp, offp, nxt, af); goto out; } #endif /* * Multicast check */ if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { /* * Make sure M_MCAST is set. It should theoretically * already be there, but let's play safe because upper * layers check for this flag. */ m->m_flags |= M_MCAST; /* * See if we belong to the destination multicast group on the * arrival interface. */ if (in6_hasmulti(&ip6->ip6_dst, ifp)) ours = 1; #ifdef MROUTING if (ip6_mforwarding && ip6_mrouter[ifp->if_rdomain]) { int error; if (ip6_hbhchcheck(m, offp, &nxt, &ours)) goto out; ip6 = mtod(m, struct ip6_hdr *); /* * If we are acting as a multicast router, all * incoming multicast packets are passed to the * kernel-level multicast forwarding function. * The packet is returned (relatively) intact; if * ip6_mforward() returns a non-zero value, the packet * must be discarded, else it may be accepted below. */ KERNEL_LOCK(); error = ip6_mforward(ip6, ifp, m); KERNEL_UNLOCK(); if (error) { ip6stat_inc(ip6s_cantforward); goto bad; } if (ours) { if (af == AF_UNSPEC) { KERNEL_LOCK(); nxt = ip_deliver(mp, offp, nxt, AF_INET6); KERNEL_UNLOCK(); } goto out; } goto bad; } #endif if (!ours) { ip6stat_inc(ip6s_notmember); if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst)) ip6stat_inc(ip6s_cantforward); goto bad; } nxt = ip6_ours(mp, offp, nxt, af); goto out; } /* * Unicast check */ memset(&sin6, 0, sizeof(struct sockaddr_in6)); sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_family = AF_INET6; sin6.sin6_addr = ip6->ip6_dst; rt = rtalloc_mpath(sin6tosa(&sin6), &ip6->ip6_src.s6_addr32[0], m->m_pkthdr.ph_rtableid); /* * Accept the packet if the route to the destination is marked * as local. */ if (rtisvalid(rt) && ISSET(rt->rt_flags, RTF_LOCAL)) { struct in6_ifaddr *ia6 = ifatoia6(rt->rt_ifa); if (ip6_forwarding == 0 && rt->rt_ifidx != ifp->if_index && !((ifp->if_flags & IFF_LOOPBACK) || (ifp->if_type == IFT_ENC) || (m->m_pkthdr.pf.flags & PF_TAG_TRANSLATE_LOCALHOST))) { /* received on wrong interface */ #if NCARP > 0 struct ifnet *out_if; /* * Virtual IPs on carp interfaces need to be checked * also against the parent interface and other carp * interfaces sharing the same parent. */ out_if = if_get(rt->rt_ifidx); if (!(out_if && carp_strict_addr_chk(out_if, ifp))) { ip6stat_inc(ip6s_wrongif); if_put(out_if); goto bad; } if_put(out_if); #else ip6stat_inc(ip6s_wrongif); goto bad; #endif } /* * packets to a tentative, duplicated, or somehow invalid * address must not be accepted. */ if ((ia6->ia6_flags & (IN6_IFF_TENTATIVE|IN6_IFF_DUPLICATED))) { char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)); inet_ntop(AF_INET6, &ip6->ip6_dst, dst, sizeof(dst)); /* address is not ready, so discard the packet. */ nd6log((LOG_INFO, "%s: packet to an unready address %s->%s\n", __func__, src, dst)); goto bad; } else { nxt = ip6_ours(mp, offp, nxt, af); goto out; } } #if NCARP > 0 if (ip6->ip6_nxt == IPPROTO_ICMPV6 && carp_lsdrop(ifp, m, AF_INET6, ip6->ip6_src.s6_addr32, ip6->ip6_dst.s6_addr32, 1)) goto bad; #endif /* * Now there is no reason to process the packet if it's not our own * and we're not a router. */ if (!ip6_forwarding) { ip6stat_inc(ip6s_cantforward); goto bad; } if (ip6_hbhchcheck(m, offp, &nxt, &ours)) goto out; if (ours) { if (af == AF_UNSPEC) { KERNEL_LOCK(); nxt = ip_deliver(mp, offp, nxt, AF_INET6); KERNEL_UNLOCK(); } goto out; } #ifdef IPSEC if (ipsec_in_use) { int rv; rv = ipsec_forward_check(m, *offp, AF_INET6); if (rv != 0) { ip6stat_inc(ip6s_cantforward); goto bad; } /* * Fall through, forward packet. Outbound IPsec policy * checking will occur in ip6_forward(). */ } #endif /* IPSEC */ ip6_forward(m, rt, srcrt); *mp = NULL; return IPPROTO_DONE; bad: nxt = IPPROTO_DONE; m_freemp(mp); out: rtfree(rt); return nxt; } int ip6_ours(struct mbuf **mp, int *offp, int nxt, int af) { if (ip6_hbhchcheck(*mp, offp, &nxt, NULL)) return IPPROTO_DONE; /* Check wheter we are already in a IPv4/IPv6 local deliver loop. */ if (af == AF_UNSPEC) nxt = ip_deliver(mp, offp, nxt, AF_INET6); return nxt; } int ip6_hbhchcheck(struct mbuf *m, int *offp, int *nxtp, int *oursp) { struct ip6_hdr *ip6; u_int32_t plen, rtalert = ~0; ip6 = mtod(m, struct ip6_hdr *); /* * Process Hop-by-Hop options header if it's contained. * m may be modified in ip6_hopopts_input(). * If a JumboPayload option is included, plen will also be modified. */ plen = (u_int32_t)ntohs(ip6->ip6_plen); *offp = sizeof(struct ip6_hdr); if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { struct ip6_hbh *hbh; if (ip6_hopopts_input(&plen, &rtalert, &m, offp)) { goto bad; /* m have already been freed */ } /* adjust pointer */ ip6 = mtod(m, struct ip6_hdr *); /* * if the payload length field is 0 and the next header field * indicates Hop-by-Hop Options header, then a Jumbo Payload * option MUST be included. */ if (ip6->ip6_plen == 0 && plen == 0) { /* * Note that if a valid jumbo payload option is * contained, ip6_hopopts_input() must set a valid * (non-zero) payload length to the variable plen. */ ip6stat_inc(ip6s_badoptions); icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); goto bad; } IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); if (hbh == NULL) { ip6stat_inc(ip6s_tooshort); goto bad; } *nxtp = hbh->ip6h_nxt; /* * accept the packet if a router alert option is included * and we act as an IPv6 router. */ if (rtalert != ~0 && ip6_forwarding && oursp != NULL) *oursp = 1; } else *nxtp = ip6->ip6_nxt; /* * Check that the amount of data in the buffers * is as at least much as the IPv6 header would have us expect. * Trim mbufs if longer than we expect. * Drop packet if shorter than we expect. */ if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { ip6stat_inc(ip6s_tooshort); m_freem(m); goto bad; } if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { if (m->m_len == m->m_pkthdr.len) { m->m_len = sizeof(struct ip6_hdr) + plen; m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; } else { m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); } } return (0); bad: *nxtp = IPPROTO_DONE; return (-1); } /* scan packet for RH0 routing header. Mostly stolen from pf.c:pf_test() */ int ip6_check_rh0hdr(struct mbuf *m, int *offp) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct ip6_rthdr rthdr; struct ip6_ext opt6; u_int8_t proto = ip6->ip6_nxt; int done = 0, lim, off, rh_cnt = 0; off = ((caddr_t)ip6 - m->m_data) + sizeof(struct ip6_hdr); lim = min(m->m_pkthdr.len, ntohs(ip6->ip6_plen) + sizeof(*ip6)); do { switch (proto) { case IPPROTO_ROUTING: *offp = off; if (rh_cnt++) { /* more than one rh header present */ return (1); } if (off + sizeof(rthdr) > lim) { /* packet to short to make sense */ return (1); } m_copydata(m, off, sizeof(rthdr), (caddr_t)&rthdr); if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) { *offp += offsetof(struct ip6_rthdr, ip6r_type); return (1); } off += (rthdr.ip6r_len + 1) * 8; proto = rthdr.ip6r_nxt; break; case IPPROTO_AH: case IPPROTO_HOPOPTS: case IPPROTO_DSTOPTS: /* get next header and header length */ if (off + sizeof(opt6) > lim) { /* * Packet to short to make sense, we could * reject the packet but as a router we * should not do that so forward it. */ return (0); } m_copydata(m, off, sizeof(opt6), (caddr_t)&opt6); if (proto == IPPROTO_AH) off += (opt6.ip6e_len + 2) * 4; else off += (opt6.ip6e_len + 1) * 8; proto = opt6.ip6e_nxt; break; case IPPROTO_FRAGMENT: default: /* end of header stack */ done = 1; break; } } while (!done); return (0); } /* * Hop-by-Hop options header processing. If a valid jumbo payload option is * included, the real payload length will be stored in plenp. * * rtalertp - XXX: should be stored in a more smart way */ int ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp, struct mbuf **mp, int *offp) { struct mbuf *m = *mp; int off = *offp, hbhlen; struct ip6_hbh *hbh; /* validation of the length of the header */ IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); if (hbh == NULL) { ip6stat_inc(ip6s_tooshort); return -1; } hbhlen = (hbh->ip6h_len + 1) << 3; IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), hbhlen); if (hbh == NULL) { ip6stat_inc(ip6s_tooshort); return -1; } off += hbhlen; hbhlen -= sizeof(struct ip6_hbh); if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), hbhlen, rtalertp, plenp) < 0) return (-1); *offp = off; *mp = m; return (0); } /* * Search header for all Hop-by-hop options and process each option. * This function is separate from ip6_hopopts_input() in order to * handle a case where the sending node itself process its hop-by-hop * options header. In such a case, the function is called from ip6_output(). * * The function assumes that hbh header is located right after the IPv6 header * (RFC2460 p7), opthead is pointer into data content in m, and opthead to * opthead + hbhlen is located in continuous memory region. */ int ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen, u_int32_t *rtalertp, u_int32_t *plenp) { struct ip6_hdr *ip6; int optlen = 0; u_int8_t *opt = opthead; u_int16_t rtalert_val; u_int32_t jumboplen; const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { switch (*opt) { case IP6OPT_PAD1: optlen = 1; break; case IP6OPT_PADN: if (hbhlen < IP6OPT_MINLEN) { ip6stat_inc(ip6s_toosmall); goto bad; } optlen = *(opt + 1) + 2; break; case IP6OPT_ROUTER_ALERT: /* XXX may need check for alignment */ if (hbhlen < IP6OPT_RTALERT_LEN) { ip6stat_inc(ip6s_toosmall); goto bad; } if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { /* XXX stat */ icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, erroff + opt + 1 - opthead); return (-1); } optlen = IP6OPT_RTALERT_LEN; memcpy((caddr_t)&rtalert_val, (caddr_t)(opt + 2), 2); *rtalertp = ntohs(rtalert_val); break; case IP6OPT_JUMBO: /* XXX may need check for alignment */ if (hbhlen < IP6OPT_JUMBO_LEN) { ip6stat_inc(ip6s_toosmall); goto bad; } if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { /* XXX stat */ icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, erroff + opt + 1 - opthead); return (-1); } optlen = IP6OPT_JUMBO_LEN; /* * IPv6 packets that have non 0 payload length * must not contain a jumbo payload option. */ ip6 = mtod(m, struct ip6_hdr *); if (ip6->ip6_plen) { ip6stat_inc(ip6s_badoptions); icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, erroff + opt - opthead); return (-1); } /* * We may see jumbolen in unaligned location, so * we'd need to perform memcpy(). */ memcpy(&jumboplen, opt + 2, sizeof(jumboplen)); jumboplen = (u_int32_t)htonl(jumboplen); #if 1 /* * if there are multiple jumbo payload options, * *plenp will be non-zero and the packet will be * rejected. * the behavior may need some debate in ipngwg - * multiple options does not make sense, however, * there's no explicit mention in specification. */ if (*plenp != 0) { ip6stat_inc(ip6s_badoptions); icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, erroff + opt + 2 - opthead); return (-1); } #endif /* * jumbo payload length must be larger than 65535. */ if (jumboplen <= IPV6_MAXPACKET) { ip6stat_inc(ip6s_badoptions); icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, erroff + opt + 2 - opthead); return (-1); } *plenp = jumboplen; break; default: /* unknown option */ if (hbhlen < IP6OPT_MINLEN) { ip6stat_inc(ip6s_toosmall); goto bad; } optlen = ip6_unknown_opt(opt, m, erroff + opt - opthead); if (optlen == -1) return (-1); optlen += 2; break; } } return (0); bad: m_freem(m); return (-1); } /* * Unknown option processing. * The third argument `off' is the offset from the IPv6 header to the option, * which allows returning an ICMPv6 error even if the IPv6 header and the * option header are not continuous. */ int ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off) { struct ip6_hdr *ip6; switch (IP6OPT_TYPE(*optp)) { case IP6OPT_TYPE_SKIP: /* ignore the option */ return ((int)*(optp + 1)); case IP6OPT_TYPE_DISCARD: /* silently discard */ m_freem(m); return (-1); case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ ip6stat_inc(ip6s_badoptions); icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); return (-1); case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ ip6stat_inc(ip6s_badoptions); ip6 = mtod(m, struct ip6_hdr *); if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || (m->m_flags & (M_BCAST|M_MCAST))) m_freem(m); else icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); return (-1); } m_freem(m); /* XXX: NOTREACHED */ return (-1); } /* * Create the "control" list for this pcb. * * The routine will be called from upper layer handlers like udp_input(). * Thus the routine assumes that the caller (udp_input) have already * called IP6_EXTHDR_CHECK() and all the extension headers are located in the * very first mbuf on the mbuf chain. * We may want to add some infinite loop prevention or sanity checks for safety. * (This applies only when you are using KAME mbuf chain restriction, i.e. * you are using IP6_EXTHDR_CHECK() not m_pulldown()) */ void ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); if (in6p->inp_socket->so_options & SO_TIMESTAMP) { struct timeval tv; m_microtime(m, &tv); *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), SCM_TIMESTAMP, SOL_SOCKET); if (*mp) mp = &(*mp)->m_next; } /* RFC 2292 sec. 5 */ if ((in6p->inp_flags & IN6P_PKTINFO) != 0) { struct in6_pktinfo pi6; memcpy(&pi6.ipi6_addr, &ip6->ip6_dst, sizeof(struct in6_addr)); if (IN6_IS_SCOPE_EMBED(&pi6.ipi6_addr)) pi6.ipi6_addr.s6_addr16[1] = 0; pi6.ipi6_ifindex = m ? m->m_pkthdr.ph_ifidx : 0; *mp = sbcreatecontrol((caddr_t) &pi6, sizeof(struct in6_pktinfo), IPV6_PKTINFO, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; } if ((in6p->inp_flags & IN6P_HOPLIMIT) != 0) { int hlim = ip6->ip6_hlim & 0xff; *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; } if ((in6p->inp_flags & IN6P_TCLASS) != 0) { u_int32_t flowinfo; int tclass; flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK); flowinfo >>= 20; tclass = flowinfo & 0xff; *mp = sbcreatecontrol((caddr_t)&tclass, sizeof(tclass), IPV6_TCLASS, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; } /* * IPV6_HOPOPTS socket option. Recall that we required super-user * privilege for the option (see ip6_ctloutput), but it might be too * strict, since there might be some hop-by-hop options which can be * returned to normal user. * See also RFC 2292 section 6 (or RFC 3542 section 8). */ if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) { /* * Check if a hop-by-hop options header is contained in the * received packet, and if so, store the options as ancillary * data. Note that a hop-by-hop options header must be * just after the IPv6 header, which is assured through the * IPv6 input processing. */ struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { struct ip6_hbh *hbh; int hbhlen = 0; struct mbuf *ext; ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), ip6->ip6_nxt); if (ext == NULL) { ip6stat_inc(ip6s_tooshort); return; } hbh = mtod(ext, struct ip6_hbh *); hbhlen = (hbh->ip6h_len + 1) << 3; if (hbhlen != ext->m_len) { m_freem(ext); ip6stat_inc(ip6s_tooshort); return; } /* * XXX: We copy the whole header even if a * jumbo payload option is included, the option which * is to be removed before returning according to * RFC2292. * Note: this constraint is removed in RFC3542. */ *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, IPV6_HOPOPTS, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; m_freem(ext); } } /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); /* * Search for destination options headers or routing * header(s) through the header chain, and stores each * header as ancillary data. * Note that the order of the headers remains in * the chain of ancillary data. */ while (1) { /* is explicit loop prevention necessary? */ struct ip6_ext *ip6e = NULL; int elen; struct mbuf *ext = NULL; /* * if it is not an extension header, don't try to * pull it from the chain. */ switch (nxt) { case IPPROTO_DSTOPTS: case IPPROTO_ROUTING: case IPPROTO_HOPOPTS: case IPPROTO_AH: /* is it possible? */ break; default: goto loopend; } ext = ip6_pullexthdr(m, off, nxt); if (ext == NULL) { ip6stat_inc(ip6s_tooshort); return; } ip6e = mtod(ext, struct ip6_ext *); if (nxt == IPPROTO_AH) elen = (ip6e->ip6e_len + 2) << 2; else elen = (ip6e->ip6e_len + 1) << 3; if (elen != ext->m_len) { m_freem(ext); ip6stat_inc(ip6s_tooshort); return; } switch (nxt) { case IPPROTO_DSTOPTS: if (!(in6p->inp_flags & IN6P_DSTOPTS)) break; *mp = sbcreatecontrol((caddr_t)ip6e, elen, IPV6_DSTOPTS, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; break; case IPPROTO_ROUTING: if (!(in6p->inp_flags & IN6P_RTHDR)) break; *mp = sbcreatecontrol((caddr_t)ip6e, elen, IPV6_RTHDR, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; break; case IPPROTO_HOPOPTS: case IPPROTO_AH: /* is it possible? */ break; default: /* * other cases have been filtered in the above. * none will visit this case. here we supply * the code just in case (nxt overwritten or * other cases). */ m_freem(ext); goto loopend; } /* proceed with the next header. */ off += elen; nxt = ip6e->ip6e_nxt; ip6e = NULL; m_freem(ext); ext = NULL; } loopend: ; } } /* * pull single extension header from mbuf chain. returns single mbuf that * contains the result, or NULL on error. */ struct mbuf * ip6_pullexthdr(struct mbuf *m, size_t off, int nxt) { struct ip6_ext ip6e; size_t elen; struct mbuf *n; #ifdef DIAGNOSTIC switch (nxt) { case IPPROTO_DSTOPTS: case IPPROTO_ROUTING: case IPPROTO_HOPOPTS: case IPPROTO_AH: /* is it possible? */ break; default: printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); } #endif if (off + sizeof(ip6e) > m->m_pkthdr.len) return NULL; m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); if (nxt == IPPROTO_AH) elen = (ip6e.ip6e_len + 2) << 2; else elen = (ip6e.ip6e_len + 1) << 3; if (off + elen > m->m_pkthdr.len) return NULL; MGET(n, M_DONTWAIT, MT_DATA); if (n && elen >= MLEN) { MCLGET(n, M_DONTWAIT); if ((n->m_flags & M_EXT) == 0) { m_free(n); n = NULL; } } if (!n) return NULL; n->m_len = 0; if (elen >= m_trailingspace(n)) { m_free(n); return NULL; } m_copydata(m, off, elen, mtod(n, caddr_t)); n->m_len = elen; return n; } /* * Get offset to the previous header followed by the header * currently processed. */ int ip6_get_prevhdr(struct mbuf *m, int off) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); if (off == sizeof(struct ip6_hdr)) { return offsetof(struct ip6_hdr, ip6_nxt); } else if (off < sizeof(struct ip6_hdr)) { panic("%s: off < sizeof(struct ip6_hdr)", __func__); } else { int len, nlen, nxt; struct ip6_ext ip6e; nxt = ip6->ip6_nxt; len = sizeof(struct ip6_hdr); nlen = 0; while (len < off) { m_copydata(m, len, sizeof(ip6e), (caddr_t)&ip6e); switch (nxt) { case IPPROTO_FRAGMENT: nlen = sizeof(struct ip6_frag); break; case IPPROTO_AH: nlen = (ip6e.ip6e_len + 2) << 2; break; default: nlen = (ip6e.ip6e_len + 1) << 3; break; } len += nlen; nxt = ip6e.ip6e_nxt; } return (len - nlen); } } /* * get next header offset. m will be retained. */ int ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp) { struct ip6_hdr ip6; struct ip6_ext ip6e; struct ip6_frag fh; /* just in case */ if (m == NULL) panic("%s: m == NULL", __func__); if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) return -1; switch (proto) { case IPPROTO_IPV6: if (m->m_pkthdr.len < off + sizeof(ip6)) return -1; m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); if (nxtp) *nxtp = ip6.ip6_nxt; off += sizeof(ip6); return off; case IPPROTO_FRAGMENT: /* * terminate parsing if it is not the first fragment, * it does not make sense to parse through it. */ if (m->m_pkthdr.len < off + sizeof(fh)) return -1; m_copydata(m, off, sizeof(fh), (caddr_t)&fh); if ((fh.ip6f_offlg & IP6F_OFF_MASK) != 0) return -1; if (nxtp) *nxtp = fh.ip6f_nxt; off += sizeof(struct ip6_frag); return off; case IPPROTO_AH: if (m->m_pkthdr.len < off + sizeof(ip6e)) return -1; m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); if (nxtp) *nxtp = ip6e.ip6e_nxt; off += (ip6e.ip6e_len + 2) << 2; if (m->m_pkthdr.len < off) return -1; return off; case IPPROTO_HOPOPTS: case IPPROTO_ROUTING: case IPPROTO_DSTOPTS: if (m->m_pkthdr.len < off + sizeof(ip6e)) return -1; m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); if (nxtp) *nxtp = ip6e.ip6e_nxt; off += (ip6e.ip6e_len + 1) << 3; if (m->m_pkthdr.len < off) return -1; return off; case IPPROTO_NONE: case IPPROTO_ESP: case IPPROTO_IPCOMP: /* give up */ return -1; default: return -1; } return -1; } /* * get offset for the last header in the chain. m will be kept untainted. */ int ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp) { int newoff; int nxt; if (!nxtp) { nxt = -1; nxtp = &nxt; } while (1) { newoff = ip6_nexthdr(m, off, proto, nxtp); if (newoff < 0) return off; else if (newoff < off) return -1; /* invalid */ else if (newoff == off) return newoff; off = newoff; proto = *nxtp; } } /* * System control for IP6 */ const u_char inet6ctlerrmap[PRC_NCMDS] = { 0, 0, 0, 0, 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, EMSGSIZE, EHOSTUNREACH, 0, 0, 0, 0, 0, 0, ENOPROTOOPT }; const struct sysctl_bounded_args ipv6ctl_vars[] = { { IPV6CTL_FORWARDING, &ip6_forwarding, 0, 1 }, { IPV6CTL_SENDREDIRECTS, &ip6_sendredirects, 0, 1 }, { IPV6CTL_DEFHLIM, &ip6_defhlim, 0, 255 }, { IPV6CTL_MAXFRAGPACKETS, &ip6_maxfragpackets, 0, 1000 }, { IPV6CTL_LOG_INTERVAL, &ip6_log_interval, 0, INT_MAX }, { IPV6CTL_HDRNESTLIMIT, &ip6_hdrnestlimit, 0, 100 }, { IPV6CTL_DAD_COUNT, &ip6_dad_count, 0, 10 }, { IPV6CTL_AUTO_FLOWLABEL, &ip6_auto_flowlabel, 0, 1 }, { IPV6CTL_DEFMCASTHLIM, &ip6_defmcasthlim, 0, 255 }, { IPV6CTL_USE_DEPRECATED, &ip6_use_deprecated, 0, 1 }, { IPV6CTL_MAXFRAGS, &ip6_maxfrags, 0, 1000 }, { IPV6CTL_MFORWARDING, &ip6_mforwarding, 0, 1 }, { IPV6CTL_MULTIPATH, &ip6_multipath, 0, 1 }, { IPV6CTL_MCAST_PMTU, &ip6_mcast_pmtu, 0, 1 }, { IPV6CTL_NEIGHBORGCTHRESH, &ip6_neighborgcthresh, -1, 5 * 2048 }, { IPV6CTL_MAXDYNROUTES, &ip6_maxdynroutes, -1, 5 * 4096 }, }; int ip6_sysctl_ip6stat(void *oldp, size_t *oldlenp, void *newp) { struct ip6stat *ip6stat; int ret; CTASSERT(sizeof(*ip6stat) == (ip6s_ncounters * sizeof(uint64_t))); ip6stat = malloc(sizeof(*ip6stat), M_TEMP, M_WAITOK); counters_read(ip6counters, (uint64_t *)ip6stat, ip6s_ncounters); ret = sysctl_rdstruct(oldp, oldlenp, newp, ip6stat, sizeof(*ip6stat)); free(ip6stat, M_TEMP, sizeof(*ip6stat)); return (ret); } int ip6_sysctl_soiikey(void *oldp, size_t *oldlenp, void *newp, size_t newlen) { uint8_t oldkey[IP6_SOIIKEY_LEN]; int error; error = suser(curproc); if (error != 0) return (error); memcpy(oldkey, ip6_soiikey, sizeof(oldkey)); error = sysctl_struct(oldp, oldlenp, newp, newlen, ip6_soiikey, sizeof(ip6_soiikey)); return (error); } int ip6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { #ifdef MROUTING extern int ip6_mrtproto; extern struct mrt6stat mrt6stat; #endif int error; /* Almost all sysctl names at this level are terminal. */ if (namelen != 1 && name[0] != IPV6CTL_IFQUEUE) return (ENOTDIR); switch (name[0]) { case IPV6CTL_DAD_PENDING: return sysctl_rdint(oldp, oldlenp, newp, ip6_dad_pending); case IPV6CTL_STATS: return (ip6_sysctl_ip6stat(oldp, oldlenp, newp)); #ifdef MROUTING case IPV6CTL_MRTSTATS: if (newp != NULL) return (EPERM); NET_LOCK(); error = sysctl_struct(oldp, oldlenp, newp, newlen, &mrt6stat, sizeof(mrt6stat)); NET_UNLOCK(); return (error); case IPV6CTL_MRTPROTO: return sysctl_rdint(oldp, oldlenp, newp, ip6_mrtproto); case IPV6CTL_MRTMIF: if (newp) return (EPERM); NET_LOCK(); error = mrt6_sysctl_mif(oldp, oldlenp); NET_UNLOCK(); return (error); case IPV6CTL_MRTMFC: if (newp) return (EPERM); NET_LOCK(); error = mrt6_sysctl_mfc(oldp, oldlenp); NET_UNLOCK(); return (error); #else case IPV6CTL_MRTSTATS: case IPV6CTL_MRTPROTO: case IPV6CTL_MRTMIF: case IPV6CTL_MRTMFC: return (EOPNOTSUPP); #endif case IPV6CTL_MTUDISCTIMEOUT: NET_LOCK(); error = sysctl_int(oldp, oldlenp, newp, newlen, &ip6_mtudisc_timeout); if (icmp6_mtudisc_timeout_q != NULL) rt_timer_queue_change(icmp6_mtudisc_timeout_q, ip6_mtudisc_timeout); NET_UNLOCK(); return (error); case IPV6CTL_IFQUEUE: return (EOPNOTSUPP); case IPV6CTL_SOIIKEY: return (ip6_sysctl_soiikey(oldp, oldlenp, newp, newlen)); default: NET_LOCK(); error = sysctl_bounded_arr(ipv6ctl_vars, nitems(ipv6ctl_vars), name, namelen, oldp, oldlenp, newp, newlen); NET_UNLOCK(); return (error); } /* NOTREACHED */ } void ip6_send_dispatch(void *xmq) { struct mbuf_queue *mq = xmq; struct mbuf *m; struct mbuf_list ml; mq_delist(mq, &ml); if (ml_empty(&ml)) return; NET_LOCK(); while ((m = ml_dequeue(&ml)) != NULL) { /* * 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. */ ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL); } NET_UNLOCK(); } void ip6_send(struct mbuf *m) { mq_enqueue(&ip6send_mq, m); task_add(net_tq(0), &ip6send_task); }