/* $NetBSD: ip6_input.c,v 1.59 2002/09/23 05:51:14 simonb 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 */ #include __KERNEL_RCSID(0, "$NetBSD: ip6_input.c,v 1.59 2002/09/23 05:51:14 simonb Exp $"); #include "opt_inet.h" #include "opt_ipsec.h" #include "opt_pfil_hooks.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef PFIL_HOOKS #include #endif #include #include #ifdef INET #include #include #endif /* INET */ #include #include #include #include #include #include #include #ifdef IPSEC #include #endif #include /* we need it for NLOOP. */ #include "loop.h" #include "faith.h" #include "gif.h" #include "bpfilter.h" #if NGIF > 0 #include #endif #include extern struct domain inet6domain; u_char ip6_protox[IPPROTO_MAX]; static int ip6qmaxlen = IFQ_MAXLEN; struct in6_ifaddr *in6_ifaddr; struct ifqueue ip6intrq; extern struct ifnet loif[NLOOP]; int ip6_forward_srcrt; /* XXX */ int ip6_sourcecheck; /* XXX */ int ip6_sourcecheck_interval; /* XXX */ #ifdef PFIL_HOOKS struct pfil_head inet6_pfil_hook; #endif struct ip6stat ip6stat; static void ip6_init2 __P((void *)); static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); /* * IP6 initialization: fill in IP6 protocol switch table. * All protocols not implemented in kernel go to raw IP6 protocol handler. */ void ip6_init() { struct ip6protosw *pr; int i; pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); if (pr == 0) panic("ip6_init"); for (i = 0; i < IPPROTO_MAX; i++) ip6_protox[i] = pr - inet6sw; for (pr = (struct ip6protosw *)inet6domain.dom_protosw; pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) if (pr->pr_domain->dom_family == PF_INET6 && pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) ip6_protox[pr->pr_protocol] = pr - inet6sw; ip6intrq.ifq_maxlen = ip6qmaxlen; nd6_init(); frag6_init(); ip6_flow_seq = arc4random(); ip6_init2((void *)0); #ifdef PFIL_HOOKS /* Register our Packet Filter hook. */ inet6_pfil_hook.ph_type = PFIL_TYPE_AF; inet6_pfil_hook.ph_af = AF_INET6; i = pfil_head_register(&inet6_pfil_hook); if (i != 0) printf("ip6_init: WARNING: unable to register pfil hook, " "error %d\n", i); #endif /* PFIL_HOOKS */ } static void ip6_init2(dummy) void *dummy; { /* nd6_timer_init */ callout_init(&nd6_timer_ch); callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); } /* * IP6 input interrupt handling. Just pass the packet to ip6_input. */ void ip6intr() { int s; struct mbuf *m; for (;;) { s = splnet(); IF_DEQUEUE(&ip6intrq, m); splx(s); if (m == 0) return; ip6_input(m); } } extern struct route_in6 ip6_forward_rt; void ip6_input(m) struct mbuf *m; { struct ip6_hdr *ip6; int off = sizeof(struct ip6_hdr), nest; u_int32_t plen; u_int32_t rtalert = ~0; int nxt, ours = 0; struct ifnet *deliverifp = NULL; #ifdef IPSEC /* * should the inner packet be considered authentic? * see comment in ah4_input(). */ m->m_flags &= ~M_AUTHIPHDR; m->m_flags &= ~M_AUTHIPDGM; #endif /* * mbuf statistics */ if (m->m_flags & M_EXT) { if (m->m_next) ip6stat.ip6s_mext2m++; else ip6stat.ip6s_mext1++; } else { #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) if (m->m_next) { if (m->m_flags & M_LOOP) { ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; else ip6stat.ip6s_m2m[0]++; } else ip6stat.ip6s_m1++; #undef M2MMAX } in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); ip6stat.ip6s_total++; #ifndef PULLDOWN_TEST /* XXX is the line really necessary? */ IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); #endif /* * If the IPv6 header is not aligned, slurp it up into a new * mbuf with space for link headers, in the event we forward * it. OTherwise, if it is aligned, make sure the entire base * IPv6 header is in the first mbuf of the chain. */ if (IP6_HDR_ALIGNED_P(mtod(m, caddr_t)) == 0) { struct ifnet *inifp = m->m_pkthdr.rcvif; if ((m = m_copyup(m, sizeof(struct ip6_hdr), (max_linkhdr + 3) & ~3)) == NULL) { /* XXXJRT new stat, please */ ip6stat.ip6s_toosmall++; in6_ifstat_inc(inifp, ifs6_in_hdrerr); return; } } else if (__predict_false(m->m_len < sizeof(struct ip6_hdr))) { struct ifnet *inifp = m->m_pkthdr.rcvif; if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { ip6stat.ip6s_toosmall++; in6_ifstat_inc(inifp, ifs6_in_hdrerr); return; } } ip6 = mtod(m, struct ip6_hdr *); if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { ip6stat.ip6s_badvers++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); goto bad; } #ifdef PFIL_HOOKS /* * Run through list of hooks for input packets. If there are any * filters which require that additional packets in the flow are * not fast-forwarded, they must clear the M_CANFASTFWD flag. * Note that filters must _never_ set this flag, as another filter * in the list may have previously cleared it. */ /* * let ipfilter look at packet on the wire, * not the decapsulated packet. */ #ifdef IPSEC if (!ipsec_getnhist(m)) #else if (1) #endif { if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN) != 0) return; if (m == NULL) return; ip6 = mtod(m, struct ip6_hdr *); } #endif /* PFIL_HOOKS */ ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; #ifdef ALTQ if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { /* packet is dropped by traffic conditioner */ return; } #endif /* * 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.ip6s_badscope++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 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.ip6s_badscope++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); goto bad; } #if 0 /* * Reject packets with IPv4 compatible addresses (auto tunnel). * * The code forbids auto tunnel relay case in RFC1933 (the check is * stronger than RFC1933). We may want to re-enable it if mech-xx * is revised to forbid relaying case. */ if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { ip6stat.ip6s_badscope++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); goto bad; } #endif if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) { if (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) { ours = 1; deliverifp = m->m_pkthdr.rcvif; goto hbhcheck; } else { ip6stat.ip6s_badscope++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); goto bad; } } /* drop packets if interface ID portion is already filled */ if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && ip6->ip6_src.s6_addr16[1]) { ip6stat.ip6s_badscope++; goto bad; } if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && ip6->ip6_dst.s6_addr16[1]) { ip6stat.ip6s_badscope++; goto bad; } } if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) ip6->ip6_src.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); /* * We use rt->rt_ifp to determine if the address is ours or not. * If rt_ifp is lo0, the address is ours. * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, * so any address under fe80::%lo0/64 will be mistakenly considered * local. The special case is supplied to handle the case properly * by actually looking at interface addresses * (using in6ifa_ifpwithaddr). */ if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0); /* m is already freed */ return; } ours = 1; deliverifp = m->m_pkthdr.rcvif; goto hbhcheck; } /* * Multicast check */ if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { struct in6_multi *in6m = 0; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); /* * See if we belong to the destination multicast group on the * arrival interface. */ IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); if (in6m) ours = 1; else if (!ip6_mrouter) { ip6stat.ip6s_notmember++; ip6stat.ip6s_cantforward++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); goto bad; } deliverifp = m->m_pkthdr.rcvif; goto hbhcheck; } /* * Unicast check */ if (ip6_forward_rt.ro_rt != NULL && (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) ip6stat.ip6s_forward_cachehit++; else { struct sockaddr_in6 *dst6; if (ip6_forward_rt.ro_rt) { /* route is down or destination is different */ ip6stat.ip6s_forward_cachemiss++; RTFREE(ip6_forward_rt.ro_rt); ip6_forward_rt.ro_rt = 0; } bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; dst6->sin6_len = sizeof(struct sockaddr_in6); dst6->sin6_family = AF_INET6; dst6->sin6_addr = ip6->ip6_dst; rtalloc((struct route *)&ip6_forward_rt); } #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) /* * Accept the packet if the forwarding interface to the destination * according to the routing table is the loopback interface, * unless the associated route has a gateway. * Note that this approach causes to accept a packet if there is a * route to the loopback interface for the destination of the packet. * But we think it's even useful in some situations, e.g. when using * a special daemon which wants to intercept the packet. */ if (ip6_forward_rt.ro_rt && (ip6_forward_rt.ro_rt->rt_flags & (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && #if 0 /* * The check below is redundant since the comparison of * the destination and the key of the rtentry has * already done through looking up the routing table. */ IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) && #endif ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { struct in6_ifaddr *ia6 = (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; if (ia6->ia6_flags & IN6_IFF_ANYCAST) m->m_flags |= M_ANYCAST6; /* * packets to a tentative, duplicated, or somehow invalid * address must not be accepted. */ if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { /* this address is ready */ ours = 1; deliverifp = ia6->ia_ifp; /* correct? */ goto hbhcheck; } else { /* address is not ready, so discard the packet. */ nd6log((LOG_INFO, "ip6_input: packet to an unready address %s->%s\n", ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst))); goto bad; } } /* * FAITH (Firewall Aided Internet Translator) */ #if defined(NFAITH) && 0 < NFAITH if (ip6_keepfaith) { if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { /* XXX do we need more sanity checks? */ ours = 1; deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ goto hbhcheck; } } #endif #if 0 { /* * Last resort: check in6_ifaddr for incoming interface. * The code is here until I update the "goto ours hack" code above * working right. */ struct ifaddr *ifa; for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next) { if (ifa->ifa_addr == NULL) continue; /* just for safety */ if (ifa->ifa_addr->sa_family != AF_INET6) continue; if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ip6->ip6_dst)) { ours = 1; deliverifp = ifa->ifa_ifp; goto hbhcheck; } } } #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.ip6s_cantforward++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); goto bad; } hbhcheck: /* * 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); if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { struct ip6_hbh *hbh; if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { #if 0 /*touches NULL pointer*/ in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); #endif return; /* 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_hoptops_input() must set a valid * (non-zero) payload length to the variable plen. */ ip6stat.ip6s_badoptions++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); return; } #ifndef PULLDOWN_TEST /* ip6_hopopts_input() ensures that mbuf is contiguous */ hbh = (struct ip6_hbh *)(ip6 + 1); #else IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); if (hbh == NULL) { ip6stat.ip6s_tooshort++; return; } #endif KASSERT(IP6_HDR_ALIGNED_P(hbh)); nxt = 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) ours = 1; } else nxt = 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.ip6s_tooshort++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); 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); } /* * Forward if desirable. */ if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { /* * 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. */ if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { ip6stat.ip6s_cantforward++; m_freem(m); return; } if (!ours) { m_freem(m); return; } } else if (!ours) { ip6_forward(m, 0); return; } ip6 = mtod(m, struct ip6_hdr *); /* * 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. * * For SIIT end node behavior, you may want to disable the check. * However, you will become vulnerable to attacks using IPv4 mapped * source. */ if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { ip6stat.ip6s_badscope++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); goto bad; } /* * Tell launch routine the next header */ #ifdef IFA_STATS if (deliverifp != NULL) { struct in6_ifaddr *ia6; ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); if (ia6) ia6->ia_ifa.ifa_data.ifad_inbytes += m->m_pkthdr.len; } #endif ip6stat.ip6s_delivered++; in6_ifstat_inc(deliverifp, ifs6_in_deliver); nest = 0; while (nxt != IPPROTO_DONE) { if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { ip6stat.ip6s_toomanyhdr++; goto bad; } /* * protection against faulty packet - there should be * more sanity checks in header chain processing. */ if (m->m_pkthdr.len < off) { ip6stat.ip6s_tooshort++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); goto bad; } #ifdef IPSEC /* * enforce IPsec policy checking if we are seeing last header. * note that we do not visit this with protocols with pcb layer * code - like udp/tcp/raw ip. */ if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && ipsec6_in_reject(m, NULL)) { ipsec6stat.in_polvio++; goto bad; } #endif nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); } return; bad: m_freem(m); } /* * Hop-by-Hop options header processing. If a valid jumbo payload option is * included, the real payload length will be stored in plenp. */ static int ip6_hopopts_input(plenp, rtalertp, mp, offp) u_int32_t *plenp; u_int32_t *rtalertp; /* XXX: should be stored more smart way */ struct mbuf **mp; int *offp; { struct mbuf *m = *mp; int off = *offp, hbhlen; struct ip6_hbh *hbh; u_int8_t *opt; /* validation of the length of the header */ #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); hbhlen = (hbh->ip6h_len + 1) << 3; IP6_EXTHDR_CHECK(m, off, hbhlen, -1); hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); #else IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); if (hbh == NULL) { ip6stat.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.ip6s_tooshort++; return -1; } #endif KASSERT(IP6_HDR_ALIGNED_P(hbh)); off += hbhlen; hbhlen -= sizeof(struct ip6_hbh); opt = (u_int8_t *)hbh + 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(m, opthead, hbhlen, rtalertp, plenp) 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.ip6s_toosmall++; goto bad; } optlen = *(opt + 1) + 2; break; case IP6OPT_RTALERT: /* XXX may need check for alignment */ if (hbhlen < IP6OPT_RTALERT_LEN) { ip6stat.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; bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); *rtalertp = ntohs(rtalert_val); break; case IP6OPT_JUMBO: /* XXX may need check for alignment */ if (hbhlen < IP6OPT_JUMBO_LEN) { ip6stat.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.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 bcopy(). */ bcopy(opt + 2, &jumboplen, 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.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.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.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 is necessary if the IPv6 header the and option header and IPv6 header * is not continuous in order to return an ICMPv6 error. */ int ip6_unknown_opt(optp, m, off) 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.ip6s_badoptions++; icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); return (-1); case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ ip6stat.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 tcp6_input(). * Thus the routine assumes that the caller (tcp6_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(in6p, mp, ip6, m) struct in6pcb *in6p; struct mbuf **mp; struct ip6_hdr *ip6; struct mbuf *m; { struct proc *p = curproc; /* XXX */ int privileged; privileged = 0; if (p && !suser(p->p_ucred, &p->p_acflag)) privileged++; #ifdef SO_TIMESTAMP if (in6p->in6p_socket->so_options & SO_TIMESTAMP) { struct timeval tv; microtime(&tv); *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), SCM_TIMESTAMP, SOL_SOCKET); if (*mp) mp = &(*mp)->m_next; } #endif if (in6p->in6p_flags & IN6P_RECVDSTADDR) { *mp = sbcreatecontrol((caddr_t) &ip6->ip6_dst, sizeof(struct in6_addr), IPV6_RECVDSTADDR, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; } #ifdef noyet /* options were tossed above */ if (in6p->in6p_flags & IN6P_RECVOPTS) /* broken */ /* ip6_srcroute doesn't do what we want here, need to fix */ if (in6p->in6p_flags & IPV6P_RECVRETOPTS) /* broken */ #endif /* RFC 2292 sec. 5 */ if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { struct in6_pktinfo pi6; bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) pi6.ipi6_addr.s6_addr16[1] = 0; pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; *mp = sbcreatecontrol((caddr_t) &pi6, sizeof(struct in6_pktinfo), IPV6_PKTINFO, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; } if (in6p->in6p_flags & IN6P_HOPLIMIT) { int hlim = ip6->ip6_hlim & 0xff; *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; } /* IN6P_NEXTHOP - for outgoing packet only */ /* * IPV6_HOPOPTS socket option. We require super-user privilege * for the option, but it might be too strict, since there might * be some hop-by-hop options which can be returned to normal user. * See RFC 2292 section 6. */ if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) { /* * Check if a hop-by-hop options header is contatined 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 fact 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; #ifndef PULLDOWN_TEST hbh = (struct ip6_hbh *)(ip6 + 1); hbhlen = (hbh->ip6h_len + 1) << 3; #else IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); if (hbh == NULL) { ip6stat.ip6s_tooshort++; return; } hbhlen = (hbh->ip6h_len + 1) << 3; IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), hbhlen); if (hbh == NULL) { ip6stat.ip6s_tooshort++; return; } #endif /* * XXX: We copy whole the header even if a jumbo * payload option is included, which option is to * be removed before returning in the RFC 2292. * But it's too painful operation... */ *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, IPV6_HOPOPTS, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; } } /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ if (in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDR)) { 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; int elen; #ifndef PULLDOWN_TEST ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); if (nxt == IPPROTO_AH) elen = (ip6e->ip6e_len + 2) << 2; else elen = (ip6e->ip6e_len + 1) << 3; #else IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, sizeof(struct ip6_ext)); if (ip6e == NULL) { ip6stat.ip6s_tooshort++; return; } if (nxt == IPPROTO_AH) elen = (ip6e->ip6e_len + 2) << 2; else elen = (ip6e->ip6e_len + 1) << 3; IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, elen); if (ip6e == NULL) { ip6stat.ip6s_tooshort++; return; } #endif KASSERT(IP6_HDR_ALIGNED_P(ip6e)); switch (nxt) { case IPPROTO_DSTOPTS: if (!in6p->in6p_flags & IN6P_DSTOPTS) break; /* * We also require super-user privilege for * the option. * See the comments on IN6_HOPOPTS. */ if (!privileged) break; *mp = sbcreatecontrol((caddr_t)ip6e, elen, IPV6_DSTOPTS, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; break; case IPPROTO_ROUTING: if (!in6p->in6p_flags & IN6P_RTHDR) break; *mp = sbcreatecontrol((caddr_t)ip6e, elen, IPV6_RTHDR, IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; break; case IPPROTO_UDP: case IPPROTO_TCP: case IPPROTO_ICMPV6: default: /* * stop search if we encounter an upper * layer protocol headers. */ goto loopend; case IPPROTO_HOPOPTS: case IPPROTO_AH: /* is it possible? */ break; } /* proceed with the next header. */ off += elen; nxt = ip6e->ip6e_nxt; } loopend: ; } if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) { /* to be done */ } if ((in6p->in6p_flags & IN6P_DSTOPTS) && privileged) { /* to be done */ } /* IN6P_RTHDR - to be done */ } /* * Get pointer to the previous header followed by the header * currently processed. * XXX: This function supposes that * M includes all headers, * the next header field and the header length field of each header * are valid, and * the sum of each header length equals to OFF. * Because of these assumptions, this function must be called very * carefully. Moreover, it will not be used in the near future when * we develop `neater' mechanism to process extension headers. */ u_int8_t * ip6_get_prevhdr(m, off) struct mbuf *m; int off; { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); if (off == sizeof(struct ip6_hdr)) return (&ip6->ip6_nxt); else { int len, nxt; struct ip6_ext *ip6e = NULL; nxt = ip6->ip6_nxt; len = sizeof(struct ip6_hdr); while (len < off) { ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); switch (nxt) { case IPPROTO_FRAGMENT: len += sizeof(struct ip6_frag); break; case IPPROTO_AH: len += (ip6e->ip6e_len + 2) << 2; break; default: len += (ip6e->ip6e_len + 1) << 3; break; } nxt = ip6e->ip6e_nxt; } if (ip6e) return (&ip6e->ip6e_nxt); else return NULL; } } /* * get next header offset. m will be retained. */ int ip6_nexthdr(m, off, proto, nxtp) 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("ip6_nexthdr: m == NULL"); 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 ((ntohs(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; } } /* * get offset for the last header in the chain. m will be kept untainted. */ int ip6_lasthdr(m, off, proto, nxtp) 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 */ 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 }; int ip6_sysctl(name, namelen, oldp, oldlenp, newp, newlen) int *name; u_int namelen; void *oldp; size_t *oldlenp; void *newp; size_t newlen; { int old, error; /* All sysctl names at this level are terminal. */ if (namelen != 1) return ENOTDIR; switch (name[0]) { case IPV6CTL_FORWARDING: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_forwarding); case IPV6CTL_SENDREDIRECTS: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_sendredirects); case IPV6CTL_DEFHLIM: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_defhlim); case IPV6CTL_MAXFRAGPACKETS: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_maxfragpackets); case IPV6CTL_ACCEPT_RTADV: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_accept_rtadv); case IPV6CTL_KEEPFAITH: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_keepfaith); case IPV6CTL_LOG_INTERVAL: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_log_interval); case IPV6CTL_HDRNESTLIMIT: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_hdrnestlimit); case IPV6CTL_DAD_COUNT: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_dad_count); case IPV6CTL_AUTO_FLOWLABEL: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_auto_flowlabel); case IPV6CTL_DEFMCASTHLIM: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_defmcasthlim); #if NGIF > 0 case IPV6CTL_GIF_HLIM: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_gif_hlim); #endif case IPV6CTL_KAME_VERSION: return sysctl_rdstring(oldp, oldlenp, newp, __KAME_VERSION); case IPV6CTL_USE_DEPRECATED: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_use_deprecated); case IPV6CTL_RR_PRUNE: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_rr_prune); case IPV6CTL_V6ONLY: #ifdef INET6_BINDV6ONLY return sysctl_rdint(oldp, oldlenp, newp, ip6_v6only); #else return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_v6only); #endif case IPV6CTL_ANONPORTMIN: old = ip6_anonportmin; error = sysctl_int(oldp, oldlenp, newp, newlen, &ip6_anonportmin); if (ip6_anonportmin >= ip6_anonportmax || ip6_anonportmin < 0 || ip6_anonportmin > 65535 #ifndef IPNOPRIVPORTS || ip6_anonportmin < IPV6PORT_RESERVED #endif ) { ip6_anonportmin = old; return (EINVAL); } return (error); case IPV6CTL_ANONPORTMAX: old = ip6_anonportmax; error = sysctl_int(oldp, oldlenp, newp, newlen, &ip6_anonportmax); if (ip6_anonportmin >= ip6_anonportmax || ip6_anonportmax < 0 || ip6_anonportmax > 65535 #ifndef IPNOPRIVPORTS || ip6_anonportmax < IPV6PORT_RESERVED #endif ) { ip6_anonportmax = old; return (EINVAL); } return (error); #ifndef IPNOPRIVPORTS case IPV6CTL_LOWPORTMIN: old = ip6_lowportmin; error = sysctl_int(oldp, oldlenp, newp, newlen, &ip6_lowportmin); if (ip6_lowportmin >= ip6_lowportmax || ip6_lowportmin > IPV6PORT_RESERVEDMAX || ip6_lowportmin < IPV6PORT_RESERVEDMIN) { ip6_lowportmin = old; return (EINVAL); } return (error); case IPV6CTL_LOWPORTMAX: old = ip6_lowportmax; error = sysctl_int(oldp, oldlenp, newp, newlen, &ip6_lowportmax); if (ip6_lowportmin >= ip6_lowportmax || ip6_lowportmax > IPV6PORT_RESERVEDMAX || ip6_lowportmax < IPV6PORT_RESERVEDMIN) { ip6_lowportmax = old; return (EINVAL); } return (error); #endif case IPV6CTL_MAXFRAGS: return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_maxfrags); default: return EOPNOTSUPP; } /* NOTREACHED */ }