/*- * 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: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei 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. * 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 __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include "opt_inet6.h" #include "opt_ipsec.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #endif /* INET */ #include #include #include #include #include #include #include #include #ifdef IPSEC #include #include #include #endif /* IPSEC */ #include extern struct domain inet6domain; u_char ip6_protox[IPPROTO_MAX]; static struct netisr_handler ip6_nh = { .nh_name = "ip6", .nh_handler = ip6_input, .nh_proto = NETISR_IPV6, .nh_policy = NETISR_POLICY_FLOW, }; VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead); VNET_DEFINE(struct ip6stat, ip6stat); VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch); VNET_DECLARE(int, dad_init); VNET_DECLARE(int, pmtu_expire); VNET_DECLARE(int, pmtu_probe); VNET_DECLARE(u_long, rip6_sendspace); VNET_DECLARE(u_long, rip6_recvspace); VNET_DECLARE(int, icmp6errppslim); VNET_DECLARE(int, icmp6_nodeinfo); VNET_DECLARE(int, udp6_sendspace); VNET_DECLARE(int, udp6_recvspace); #define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch) #define V_dad_init VNET(dad_init) #define V_pmtu_expire VNET(pmtu_expire) #define V_pmtu_probe VNET(pmtu_probe) #define V_rip6_sendspace VNET(rip6_sendspace) #define V_rip6_recvspace VNET(rip6_recvspace) #define V_icmp6errppslim VNET(icmp6errppslim) #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo) #define V_udp6_sendspace VNET(udp6_sendspace) #define V_udp6_recvspace VNET(udp6_recvspace) struct rwlock in6_ifaddr_lock; RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock"); VNET_DEFINE (struct pfil_head, inet6_pfil_hook); static void ip6_init2(void *); static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *); static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *); #ifdef PULLDOWN_TEST static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int); #endif /* * IP6 initialization: fill in IP6 protocol switch table. * All protocols not implemented in kernel go to raw IP6 protocol handler. */ void ip6_init(void) { struct ip6protosw *pr; int i; V_in6_maxmtu = 0; #ifdef IP6_AUTO_LINKLOCAL V_ip6_auto_linklocal = IP6_AUTO_LINKLOCAL; #else V_ip6_auto_linklocal = 1; /* enabled by default */ #endif TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal", &V_ip6_auto_linklocal); #ifndef IPV6FORWARDING #ifdef GATEWAY6 #define IPV6FORWARDING 1 /* forward IP6 packets not for us */ #else #define IPV6FORWARDING 0 /* don't forward IP6 packets not for us */ #endif /* GATEWAY6 */ #endif /* !IPV6FORWARDING */ #ifndef IPV6_SENDREDIRECTS #define IPV6_SENDREDIRECTS 1 #endif V_ip6_forwarding = IPV6FORWARDING; /* act as router? */ V_ip6_sendredirects = IPV6_SENDREDIRECTS; V_ip6_defhlim = IPV6_DEFHLIM; V_ip6_defmcasthlim = IPV6_DEFAULT_MULTICAST_HOPS; V_ip6_accept_rtadv = 0; V_ip6_log_interval = 5; V_ip6_hdrnestlimit = 15; /* How many header options will we process? */ V_ip6_dad_count = 1; /* DupAddrDetectionTransmits */ V_ip6_auto_flowlabel = 1; V_ip6_use_deprecated = 1;/* allow deprecated addr (RFC2462 5.5.4) */ V_ip6_rr_prune = 5; /* router renumbering prefix * walk list every 5 sec. */ V_ip6_mcast_pmtu = 0; /* enable pMTU discovery for multicast? */ V_ip6_v6only = 1; V_ip6_keepfaith = 0; V_ip6_log_time = (time_t)0L; #ifdef IPSTEALTH V_ip6stealth = 0; #endif V_nd6_onlink_ns_rfc4861 = 0; /* allow 'on-link' nd6 NS (RFC 4861) */ V_pmtu_expire = 60*10; V_pmtu_probe = 60*2; /* raw IP6 parameters */ /* * Nominal space allocated to a raw ip socket. */ #define RIPV6SNDQ 8192 #define RIPV6RCVQ 8192 V_rip6_sendspace = RIPV6SNDQ; V_rip6_recvspace = RIPV6RCVQ; /* ICMPV6 parameters */ V_icmp6_rediraccept = 1; /* accept and process redirects */ V_icmp6_redirtimeout = 10 * 60; /* 10 minutes */ V_icmp6errppslim = 100; /* 100pps */ /* control how to respond to NI queries */ V_icmp6_nodeinfo = (ICMP6_NODEINFO_FQDNOK|ICMP6_NODEINFO_NODEADDROK); /* UDP on IP6 parameters */ V_udp6_sendspace = 9216; /* really max datagram size */ V_udp6_recvspace = 40 * (1024 + sizeof(struct sockaddr_in6)); /* 40 1K datagrams */ V_dad_init = 0; TAILQ_INIT(&V_in6_ifaddrhead); scope6_init(); addrsel_policy_init(); nd6_init(); frag6_init(); V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR; /* Initialize packet filter hooks. */ V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF; V_inet6_pfil_hook.ph_af = AF_INET6; if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0) printf("%s: WARNING: unable to register pfil hook, " "error %d\n", __func__, i); /* Skip global initialization stuff for non-default instances. */ if (!IS_DEFAULT_VNET(curvnet)) return; #ifdef DIAGNOSTIC if (sizeof(struct protosw) != sizeof(struct ip6protosw)) panic("sizeof(protosw) != sizeof(ip6protosw)"); #endif pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); if (pr == NULL) panic("ip6_init"); /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */ for (i = 0; i < IPPROTO_MAX; i++) ip6_protox[i] = pr - inet6sw; /* * Cycle through IP protocols and put them into the appropriate place * in ip6_protox[]. */ 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) { /* Be careful to only index valid IP protocols. */ if (pr->pr_protocol < IPPROTO_MAX) ip6_protox[pr->pr_protocol] = pr - inet6sw; } netisr_register(&ip6_nh); } #ifdef VIMAGE void ip6_destroy() { nd6_destroy(); callout_drain(&V_in6_tmpaddrtimer_ch); } #endif static int ip6_init2_vnet(const void *unused __unused) { /* nd6_timer_init */ callout_init(&V_nd6_timer_ch, 0); callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet); /* timer for regeneranation of temporary addresses randomize ID */ callout_init(&V_in6_tmpaddrtimer_ch, 0); callout_reset(&V_in6_tmpaddrtimer_ch, (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor - V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, curvnet); return (0); } static void ip6_init2(void *dummy) { ip6_init2_vnet(NULL); } /* cheat */ /* This must be after route_init(), which is now SI_ORDER_THIRD */ SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); void ip6_input(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, *ifp = NULL; struct in6_addr odst; struct route_in6 rin6; int srcrt = 0; struct llentry *lle = NULL; struct sockaddr_in6 dst6, *dst; bzero(&rin6, sizeof(struct route_in6)); #ifdef IPSEC /* * should the inner packet be considered authentic? * see comment in ah4_input(). * NB: m cannot be NULL when passed to the input routine */ m->m_flags &= ~M_AUTHIPHDR; m->m_flags &= ~M_AUTHIPDGM; #endif /* IPSEC */ /* * make sure we don't have onion peering information into m_tag. */ ip6_delaux(m); /* * mbuf statistics */ if (m->m_flags & M_EXT) { if (m->m_next) V_ip6stat.ip6s_mext2m++; else V_ip6stat.ip6s_mext1++; } else { #define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0])) if (m->m_next) { if (m->m_flags & M_LOOP) { V_ip6stat.ip6s_m2m[V_loif->if_index]++; } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; else V_ip6stat.ip6s_m2m[0]++; } else V_ip6stat.ip6s_m1++; #undef M2MMAX } /* drop the packet if IPv6 operation is disabled on the IF */ if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) { m_freem(m); return; } in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); V_ip6stat.ip6s_total++; #ifndef PULLDOWN_TEST /* * L2 bridge code and some other code can return mbuf chain * that does not conform to KAME requirement. too bad. * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? */ if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { struct mbuf *n; MGETHDR(n, M_DONTWAIT, MT_HEADER); if (n) M_MOVE_PKTHDR(n, m); if (n && n->m_pkthdr.len > MHLEN) { MCLGET(n, M_DONTWAIT); if ((n->m_flags & M_EXT) == 0) { m_freem(n); n = NULL; } } if (n == NULL) { m_freem(m); return; /* ENOBUFS */ } m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); n->m_len = n->m_pkthdr.len; m_freem(m); m = n; } IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */); #endif if (m->m_len < sizeof(struct ip6_hdr)) { struct ifnet *inifp; inifp = m->m_pkthdr.rcvif; if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) { V_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) { V_ip6stat.ip6s_badvers++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); goto bad; } V_ip6stat.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. */ V_ip6stat.ip6s_badscope++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); 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. */ V_ip6stat.ip6s_badscope++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); goto bad; } #ifdef ALTQ if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) { /* packet is dropped by traffic conditioner */ return; } #endif /* * 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)) { V_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)) { V_ip6stat.ip6s_badscope++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); goto bad; } #endif /* * Run through list of hooks for input packets. * * NB: Beware of the destination address changing * (e.g. by NAT rewriting). When this happens, * tell ip6_forward to do the right thing. */ odst = ip6->ip6_dst; /* Jump over all PFIL processing if hooks are not active. */ if (!PFIL_HOOKED(&V_inet6_pfil_hook)) goto passin; if (pfil_run_hooks(&V_inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL)) return; if (m == NULL) /* consumed by filter */ return; ip6 = mtod(m, struct ip6_hdr *); srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); passin: /* * Disambiguate address scope zones (if there is ambiguity). * We first make sure that the original source or destination address * is not in our internal form for scoped addresses. Such addresses * are not necessarily invalid spec-wise, but we cannot accept them due * to the usage conflict. * in6_setscope() then also checks and rejects the cases where src or * dst are the loopback address and the receiving interface * is not loopback. */ if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) { V_ip6stat.ip6s_badscope++; /* XXX */ goto bad; } if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) || in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) { V_ip6stat.ip6s_badscope++; goto bad; } /* * Multicast check. Assume packet is for us to avoid * prematurely taking locks. */ if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { ours = 1; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); deliverifp = m->m_pkthdr.rcvif; goto hbhcheck; } /* * Unicast check */ bzero(&dst6, sizeof(dst6)); dst6.sin6_family = AF_INET6; dst6.sin6_len = sizeof(struct sockaddr_in6); dst6.sin6_addr = ip6->ip6_dst; ifp = m->m_pkthdr.rcvif; IF_AFDATA_LOCK(ifp); lle = lla_lookup(LLTABLE6(ifp), 0, (struct sockaddr *)&dst6); IF_AFDATA_UNLOCK(ifp); if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) { ours = 1; deliverifp = ifp; LLE_RUNLOCK(lle); goto hbhcheck; } if (lle != NULL) LLE_RUNLOCK(lle); dst = &rin6.ro_dst; dst->sin6_len = sizeof(struct sockaddr_in6); dst->sin6_family = AF_INET6; dst->sin6_addr = ip6->ip6_dst; rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0); if (rin6.ro_rt) RT_UNLOCK(rin6.ro_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. * * XXX: some OSes automatically make a cloned route for the destination * of an outgoing packet. If the outgoing interface of the packet * is a loopback one, the kernel would consider the packet to be * accepted, even if we have no such address assinged on the interface. * We check the cloned flag of the route entry to reject such cases, * assuming that route entries for our own addresses are not made by * cloning (it should be true because in6_addloop explicitly installs * the host route). However, we might have to do an explicit check * while it would be less efficient. Or, should we rather install a * reject route for such a case? */ if (rin6.ro_rt && (rin6.ro_rt->rt_flags & (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && #ifdef RTF_WASCLONED !(rin6.ro_rt->rt_flags & RTF_WASCLONED) && #endif #ifdef RTF_CLONED !(rin6.ro_rt->rt_flags & RTF_CLONED) && #endif #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(rin6.ro_rt)->sin6_addr) #endif rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) { int free_ia6 = 0; struct in6_ifaddr *ia6; /* * found the loopback route to the interface address */ if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) { struct sockaddr_in6 dest6; bzero(&dest6, sizeof(dest6)); dest6.sin6_family = AF_INET6; dest6.sin6_len = sizeof(dest6); dest6.sin6_addr = ip6->ip6_dst; ia6 = (struct in6_ifaddr *) ifa_ifwithaddr((struct sockaddr *)&dest6); if (ia6 == NULL) goto bad; free_ia6 = 1; } else ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa; /* * record address information into m_tag. */ (void)ip6_setdstifaddr(m, ia6); /* * 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? */ /* Count the packet in the ip address stats */ ia6->ia_ifa.if_ipackets++; ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; if (ia6 != NULL && free_ia6 != 0) ifa_free(&ia6->ia_ifa); goto hbhcheck; } else { char ip6bufs[INET6_ADDRSTRLEN]; char ip6bufd[INET6_ADDRSTRLEN]; /* address is not ready, so discard the packet. */ nd6log((LOG_INFO, "ip6_input: packet to an unready address %s->%s\n", ip6_sprintf(ip6bufs, &ip6->ip6_src), ip6_sprintf(ip6bufd, &ip6->ip6_dst))); if (ia6 != NULL && free_ia6 != 0) ifa_free(&ia6->ia_ifa); goto bad; } } /* * FAITH (Firewall Aided Internet Translator) */ if (V_ip6_keepfaith) { if (rin6.ro_rt && rin6.ro_rt->rt_ifp && rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) { /* XXX do we need more sanity checks? */ ours = 1; deliverifp = rin6.ro_rt->rt_ifp; /* faith */ goto hbhcheck; } } /* * Now there is no reason to process the packet if it's not our own * and we're not a router. */ if (!V_ip6_forwarding) { V_ip6stat.ip6s_cantforward++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); goto bad; } hbhcheck: /* * record address information into m_tag, if we don't have one yet. * note that we are unable to record it, if the address is not listed * as our interface address (e.g. multicast addresses, addresses * within FAITH prefixes and such). */ if (deliverifp && !ip6_getdstifaddr(m)) { struct in6_ifaddr *ia6; ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); if (ia6) { if (!ip6_setdstifaddr(m, ia6)) { /* * XXX maybe we should drop the packet here, * as we could not provide enough information * to the upper layers. */ } ifa_free(&ia6->ia_ifa); } } /* * 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 goto out; /* 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. */ V_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); goto out; } #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) { V_ip6stat.ip6s_tooshort++; goto out; } #endif nxt = hbh->ip6h_nxt; /* * If we are acting as a router and the packet contains a * router alert option, see if we know the option value. * Currently, we only support the option value for MLD, in which * case we should pass the packet to the multicast routing * daemon. */ if (rtalert != ~0) { switch (rtalert) { case IP6OPT_RTALERT_MLD: if (V_ip6_forwarding) ours = 1; break; default: /* * RFC2711 requires unrecognized values must be * silently ignored. */ break; } } } 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) { V_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 (V_ip6_mrouter && 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. * * XXX TODO: Check hlim and multicast scope here to avoid * unnecessarily calling into ip6_mforward(). */ if (ip6_mforward && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { IP6STAT_INC(ip6s_cantforward); in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); goto bad; } } else if (!ours) { ip6_forward(m, srcrt); goto out; } 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)) { V_ip6stat.ip6s_badscope++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); goto bad; } /* * Tell launch routine the next header */ V_ip6stat.ip6s_delivered++; in6_ifstat_inc(deliverifp, ifs6_in_deliver); nest = 0; while (nxt != IPPROTO_DONE) { if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) { V_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) { V_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 (ip6_ipsec_input(m, nxt)) goto bad; #endif /* IPSEC */ /* * Use mbuf flags to propagate Router Alert option to * ICMPv6 layer, as hop-by-hop options have been stripped. */ if (nxt == IPPROTO_ICMPV6 && rtalert != ~0) m->m_flags |= M_RTALERT_MLD; nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); } goto out; bad: m_freem(m); out: if (rin6.ro_rt) RTFREE(rin6.ro_rt); } /* * set/grab in6_ifaddr correspond to IPv6 destination address. * XXX backward compatibility wrapper * * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag, * and then bump it when the tag is copied, and release it when the tag is * freed. Unfortunately, m_tags don't support deep copies (yet), so instead * we just bump the ia refcount when we receive it. This should be fixed. */ static struct ip6aux * ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6) { struct ip6aux *ip6a; ip6a = ip6_addaux(m); if (ip6a) ip6a->ip6a_dstia6 = ia6; return ip6a; /* NULL if failed to set */ } struct in6_ifaddr * ip6_getdstifaddr(struct mbuf *m) { struct ip6aux *ip6a; struct in6_ifaddr *ia; ip6a = ip6_findaux(m); if (ip6a) { ia = ip6a->ip6a_dstia6; ifa_ref(&ia->ia_ifa); return ia; } else return NULL; } /* * 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 more smart way */ static 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; 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) { V_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) { V_ip6stat.ip6s_tooshort++; return -1; } #endif 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(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) { V_ip6stat.ip6s_toosmall++; goto bad; } optlen = *(opt + 1) + 2; break; case IP6OPT_ROUTER_ALERT: /* XXX may need check for alignment */ if (hbhlen < IP6OPT_RTALERT_LEN) { V_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) { V_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) { V_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) { V_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) { V_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) { V_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(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 */ V_ip6stat.ip6s_badoptions++; icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); return (-1); case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ V_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. * These functions will not modify mbuf chain at all. * * With KAME mbuf chain restriction: * 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. * * ip6_savecontrol_v4 will handle those options that are possible to be * set on a v4-mapped socket. * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those * options and handle the v6-only ones itself. */ struct mbuf ** ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp, int *v4only) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); #ifdef SO_TIMESTAMP if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) { struct timeval tv; microtime(&tv); *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), SCM_TIMESTAMP, SOL_SOCKET); if (*mp) mp = &(*mp)->m_next; } #endif if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { if (v4only != NULL) *v4only = 1; return (mp); } #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y)) /* RFC 2292 sec. 5 */ if ((inp->inp_flags & IN6P_PKTINFO) != 0) { struct in6_pktinfo pi6; bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); in6_clearscope(&pi6.ipi6_addr); /* XXX */ pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0; *mp = sbcreatecontrol((caddr_t) &pi6, sizeof(struct in6_pktinfo), IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; } if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) { int hlim = ip6->ip6_hlim & 0xff; *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int), IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; } if (v4only != NULL) *v4only = 0; return (mp); } void ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); int v4only = 0; mp = ip6_savecontrol_v4(in6p, m, mp, &v4only); if (v4only) return; 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 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 is assured through the * IPv6 input processing. */ if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { struct ip6_hbh *hbh; int hbhlen = 0; #ifdef PULLDOWN_TEST struct mbuf *ext; #endif #ifndef PULLDOWN_TEST hbh = (struct ip6_hbh *)(ip6 + 1); hbhlen = (hbh->ip6h_len + 1) << 3; #else ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), ip6->ip6_nxt); if (ext == NULL) { V_ip6stat.ip6s_tooshort++; return; } hbh = mtod(ext, struct ip6_hbh *); hbhlen = (hbh->ip6h_len + 1) << 3; if (hbhlen != ext->m_len) { m_freem(ext); V_ip6stat.ip6s_tooshort++; return; } #endif /* * 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, IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS), IPPROTO_IPV6); if (*mp) mp = &(*mp)->m_next; #ifdef PULLDOWN_TEST m_freem(ext); #endif } } if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) { 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; #ifdef PULLDOWN_TEST struct mbuf *ext = NULL; #endif /* * 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; } #ifndef PULLDOWN_TEST if (off + sizeof(*ip6e) > m->m_len) goto loopend; 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; if (off + elen > m->m_len) goto loopend; #else ext = ip6_pullexthdr(m, off, nxt); if (ext == NULL) { V_ip6stat.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); V_ip6stat.ip6s_tooshort++; return; } #endif switch (nxt) { case IPPROTO_DSTOPTS: if (!(in6p->inp_flags & IN6P_DSTOPTS)) break; *mp = sbcreatecontrol((caddr_t)ip6e, elen, IS2292(in6p, IPV6_2292DSTOPTS, 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, IS2292(in6p, IPV6_2292RTHDR, 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). */ #ifdef PULLDOWN_TEST m_freem(ext); #endif goto loopend; } /* proceed with the next header. */ off += elen; nxt = ip6e->ip6e_nxt; ip6e = NULL; #ifdef PULLDOWN_TEST m_freem(ext); ext = NULL; #endif } loopend: ; } } #undef IS2292 void ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu) { struct socket *so; struct mbuf *m_mtu; struct ip6_mtuinfo mtuctl; so = in6p->inp_socket; if (mtu == NULL) return; #ifdef DIAGNOSTIC if (so == NULL) /* I believe this is impossible */ panic("ip6_notify_pmtu: socket is NULL"); #endif bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */ mtuctl.ip6m_mtu = *mtu; mtuctl.ip6m_addr = *dst; if (sa6_recoverscope(&mtuctl.ip6m_addr)) return; if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl), IPV6_PATHMTU, IPPROTO_IPV6)) == NULL) return; if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu) == 0) { m_freem(m_mtu); /* XXX: should count statistics */ } else sorwakeup(so); return; } #ifdef PULLDOWN_TEST /* * pull single extension header from mbuf chain. returns single mbuf that * contains the result, or NULL on error. */ static 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 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; 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; } #endif /* * 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. */ char * ip6_get_prevhdr(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(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); /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */ if (fh.ip6f_offlg & IP6F_OFF_MASK) 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; 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; 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; } } struct ip6aux * ip6_addaux(struct mbuf *m) { struct m_tag *mtag; mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); if (!mtag) { mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux), M_NOWAIT); if (mtag) { m_tag_prepend(m, mtag); bzero(mtag + 1, sizeof(struct ip6aux)); } } return mtag ? (struct ip6aux *)(mtag + 1) : NULL; } struct ip6aux * ip6_findaux(struct mbuf *m) { struct m_tag *mtag; mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); return mtag ? (struct ip6aux *)(mtag + 1) : NULL; } void ip6_delaux(struct mbuf *m) { struct m_tag *mtag; mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); if (mtag) m_tag_delete(m, mtag); } /* * 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 };