/* * Ethernet link layer output routine to send a raw frame to the device. * * This assumes that the 14 byte Ethernet header is present and contiguous * in the first mbuf (if BRIDGE'ing). */ int ether_output_frame(struct ifnet *ifp, struct mbuf *m) { int i; if (PFIL_HOOKED(&V_link_pfil_hook)) { i = pfil_run_hooks(&V_link_pfil_hook, &m, ifp, PFIL_OUT, NULL); if (i != 0) return (EACCES); if (m == NULL) return (0); } /* * Queue message on interface, update output statistics if * successful, and start output if interface not yet active. */ return ((ifp->if_transmit)(ifp, m)); }
/* * Forward a packet. If some error occurs return the sender * an icmp packet. Note we can't always generate a meaningful * icmp message because icmp doesn't have a large enough repertoire * of codes and types. * * If not forwarding, just drop the packet. This could be confusing * if ipforwarding was zero but some routing protocol was advancing * us as a gateway to somewhere. However, we must let the routing * protocol deal with that. * */ void ip6_forward(struct mbuf *m, int srcrt) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct sockaddr_in6 *dst = NULL; struct rtentry *rt = NULL; struct route_in6 rin6; int error, type = 0, code = 0; struct mbuf *mcopy = NULL; struct ifnet *origifp; /* maybe unnecessary */ u_int32_t inzone, outzone; struct in6_addr src_in6, dst_in6, odst; struct m_tag *fwd_tag; char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; /* * Do not forward packets to multicast destination (should be handled * by ip6_mforward(). * Do not forward packets with unspecified source. It was discussed * in July 2000, on the ipngwg mailing list. */ if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { IP6STAT_INC(ip6s_cantforward); /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { V_ip6_log_time = time_uptime; log(LOG_DEBUG, "cannot forward " "from %s to %s nxt %d received on %s\n", ip6_sprintf(ip6bufs, &ip6->ip6_src), ip6_sprintf(ip6bufd, &ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif)); } m_freem(m); return; } if ( #ifdef IPSTEALTH V_ip6stealth == 0 && #endif ip6->ip6_hlim <= IPV6_HLIMDEC) { /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ icmp6_error(m, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT, 0); return; } /* * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - * size of IPv6 + ICMPv6 headers) bytes of the packet in case * we need to generate an ICMP6 message to the src. * Thanks to M_EXT, in most cases copy will not occur. * * It is important to save it before IPsec processing as IPsec * processing may modify the mbuf. */ mcopy = m_copym(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN), M_NOWAIT); #ifdef IPSTEALTH if (V_ip6stealth == 0) #endif ip6->ip6_hlim -= IPV6_HLIMDEC; #if defined(IPSEC) || defined(IPSEC_SUPPORT) if (IPSEC_ENABLED(ipv6)) { if ((error = IPSEC_FORWARD(ipv6, m)) != 0) { /* mbuf consumed by IPsec */ m_freem(mcopy); if (error != EINPROGRESS) IP6STAT_INC(ip6s_cantforward); return; } /* No IPsec processing required */ } #endif again: bzero(&rin6, sizeof(struct route_in6)); dst = (struct sockaddr_in6 *)&rin6.ro_dst; dst->sin6_len = sizeof(struct sockaddr_in6); dst->sin6_family = AF_INET6; dst->sin6_addr = ip6->ip6_dst; again2: rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m)); rt = rin6.ro_rt; if (rin6.ro_rt != NULL) RT_UNLOCK(rin6.ro_rt); else { IP6STAT_INC(ip6s_noroute); in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); if (mcopy) { icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE, 0); } goto bad; } /* * Source scope check: if a packet can't be delivered to its * destination for the reason that the destination is beyond the scope * of the source address, discard the packet and return an icmp6 * destination unreachable error with Code 2 (beyond scope of source * address). We use a local copy of ip6_src, since in6_setscope() * will possibly modify its first argument. * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] */ src_in6 = ip6->ip6_src; if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { /* XXX: this should not happen */ IP6STAT_INC(ip6s_cantforward); IP6STAT_INC(ip6s_badscope); goto bad; } if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { IP6STAT_INC(ip6s_cantforward); IP6STAT_INC(ip6s_badscope); goto bad; } if (inzone != outzone) { IP6STAT_INC(ip6s_cantforward); IP6STAT_INC(ip6s_badscope); in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { V_ip6_log_time = time_uptime; log(LOG_DEBUG, "cannot forward " "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", ip6_sprintf(ip6bufs, &ip6->ip6_src), ip6_sprintf(ip6bufd, &ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); } if (mcopy) icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_BEYONDSCOPE, 0); goto bad; } /* * Destination scope check: if a packet is going to break the scope * zone of packet's destination address, discard it. This case should * usually be prevented by appropriately-configured routing table, but * we need an explicit check because we may mistakenly forward the * packet to a different zone by (e.g.) a default route. */ dst_in6 = ip6->ip6_dst; if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || inzone != outzone) { IP6STAT_INC(ip6s_cantforward); IP6STAT_INC(ip6s_badscope); goto bad; } if (rt->rt_flags & RTF_GATEWAY) dst = (struct sockaddr_in6 *)rt->rt_gateway; /* * If we are to forward the packet using the same interface * as one we got the packet from, perhaps we should send a redirect * to sender to shortcut a hop. * Only send redirect if source is sending directly to us, * and if packet was not source routed (or has any options). * Also, don't send redirect if forwarding using a route * modified by a redirect. */ if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { /* * If the incoming interface is equal to the outgoing * one, and the link attached to the interface is * point-to-point, then it will be highly probable * that a routing loop occurs. Thus, we immediately * drop the packet and send an ICMPv6 error message. * * type/code is based on suggestion by Rich Draves. * not sure if it is the best pick. */ icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0); goto bad; } type = ND_REDIRECT; } /* * Fake scoped addresses. Note that even link-local source or * destinaion can appear, if the originating node just sends the * packet to us (without address resolution for the destination). * Since both icmp6_error and icmp6_redirect_output fill the embedded * link identifiers, we can do this stuff after making a copy for * returning an error. */ if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { /* * See corresponding comments in ip6_output. * XXX: but is it possible that ip6_forward() sends a packet * to a loopback interface? I don't think so, and thus * I bark here. ([email protected]) * XXX: it is common to route invalid packets to loopback. * also, the codepath will be visited on use of ::1 in * rthdr. (itojun) */ #if 1 if (0) #else if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) #endif { printf("ip6_forward: outgoing interface is loopback. " "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", ip6_sprintf(ip6bufs, &ip6->ip6_src), ip6_sprintf(ip6bufd, &ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); } /* we can just use rcvif in forwarding. */ origifp = m->m_pkthdr.rcvif; } else origifp = rt->rt_ifp; /* * clear embedded scope identifiers if necessary. * in6_clearscope will touch the addresses only when necessary. */ in6_clearscope(&ip6->ip6_src); in6_clearscope(&ip6->ip6_dst); /* Jump over all PFIL processing if hooks are not active. */ if (!PFIL_HOOKED(&V_inet6_pfil_hook)) goto pass; odst = ip6->ip6_dst; /* Run through list of hooks for output packets. */ error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); if (error != 0 || m == NULL) goto freecopy; /* consumed by filter */ ip6 = mtod(m, struct ip6_hdr *); /* See if destination IP address was changed by packet filter. */ if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) { m->m_flags |= M_SKIP_FIREWALL; /* If destination is now ourself drop to ip6_input(). */ if (in6_localip(&ip6->ip6_dst)) m->m_flags |= M_FASTFWD_OURS; else { RTFREE(rt); goto again; /* Redo the routing table lookup. */ } } /* See if local, if yes, send it to netisr. */ if (m->m_flags & M_FASTFWD_OURS) { if (m->m_pkthdr.rcvif == NULL) m->m_pkthdr.rcvif = V_loif; if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { m->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; m->m_pkthdr.csum_data = 0xffff; } #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; #endif error = netisr_queue(NETISR_IPV6, m); goto out; } /* Or forward to some other address? */ if ((m->m_flags & M_IP6_NEXTHOP) && (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { dst = (struct sockaddr_in6 *)&rin6.ro_dst; bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6)); m->m_flags |= M_SKIP_FIREWALL; m->m_flags &= ~M_IP6_NEXTHOP; m_tag_delete(m, fwd_tag); RTFREE(rt); goto again2; } pass: /* See if the size was changed by the packet filter. */ if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); if (mcopy) icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, IN6_LINKMTU(rt->rt_ifp)); goto bad; } error = nd6_output_ifp(rt->rt_ifp, origifp, m, dst, NULL); if (error) { in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); IP6STAT_INC(ip6s_cantforward); } else { IP6STAT_INC(ip6s_forward); in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); if (type) IP6STAT_INC(ip6s_redirectsent); else { if (mcopy) goto freecopy; } } if (mcopy == NULL) goto out; switch (error) { case 0: if (type == ND_REDIRECT) { icmp6_redirect_output(mcopy, rt); goto out; } goto freecopy; case EMSGSIZE: /* xxx MTU is constant in PPP? */ goto freecopy; case ENOBUFS: /* Tell source to slow down like source quench in IP? */ goto freecopy; case ENETUNREACH: /* shouldn't happen, checked above */ case EHOSTUNREACH: case ENETDOWN: case EHOSTDOWN: default: type = ICMP6_DST_UNREACH; code = ICMP6_DST_UNREACH_ADDR; break; } icmp6_error(mcopy, type, code, 0); goto out; freecopy: m_freem(mcopy); goto out; bad: m_freem(m); out: if (rt != NULL) RTFREE(rt); }
/* * Forward a packet. If some error occurs return the sender * an icmp packet. Note we can't always generate a meaningful * icmp message because icmp doesn't have a large enough repertoire * of codes and types. * * If not forwarding, just drop the packet. This could be confusing * if ipforwarding was zero but some routing protocol was advancing * us as a gateway to somewhere. However, we must let the routing * protocol deal with that. * */ void ip6_forward(struct mbuf *m, int srcrt) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct sockaddr_in6 *dst = NULL; struct rtentry *rt = NULL; struct route_in6 rin6; int error, type = 0, code = 0; struct mbuf *mcopy = NULL; struct ifnet *origifp; /* maybe unnecessary */ u_int32_t inzone, outzone; struct in6_addr src_in6, dst_in6, odst; #ifdef IPSEC struct secpolicy *sp = NULL; #endif #ifdef SCTP int sw_csum; #endif struct m_tag *fwd_tag; char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; #ifdef IPSEC /* * Check AH/ESP integrity. */ /* * Don't increment ip6s_cantforward because this is the check * before forwarding packet actually. */ if (ipsec6_in_reject(m, NULL)) { IPSEC6STAT_INC(ips_in_polvio); m_freem(m); return; } #endif /* IPSEC */ /* * Do not forward packets to multicast destination (should be handled * by ip6_mforward(). * Do not forward packets with unspecified source. It was discussed * in July 2000, on the ipngwg mailing list. */ if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { IP6STAT_INC(ip6s_cantforward); /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { V_ip6_log_time = time_uptime; log(LOG_DEBUG, "cannot forward " "from %s to %s nxt %d received on %s\n", ip6_sprintf(ip6bufs, &ip6->ip6_src), ip6_sprintf(ip6bufd, &ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif)); } m_freem(m); return; } #ifdef IPSTEALTH if (!V_ip6stealth) { #endif if (ip6->ip6_hlim <= IPV6_HLIMDEC) { /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ icmp6_error(m, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT, 0); return; } ip6->ip6_hlim -= IPV6_HLIMDEC; #ifdef IPSTEALTH } #endif /* * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - * size of IPv6 + ICMPv6 headers) bytes of the packet in case * we need to generate an ICMP6 message to the src. * Thanks to M_EXT, in most cases copy will not occur. * * It is important to save it before IPsec processing as IPsec * processing may modify the mbuf. */ mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); #ifdef IPSEC /* get a security policy for this packet */ sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, &error); if (sp == NULL) { IPSEC6STAT_INC(ips_out_inval); IP6STAT_INC(ip6s_cantforward); if (mcopy) { #if 0 /* XXX: what icmp ? */ #else m_freem(mcopy); #endif } m_freem(m); return; } error = 0; /* check policy */ switch (sp->policy) { case IPSEC_POLICY_DISCARD: /* * This packet is just discarded. */ IPSEC6STAT_INC(ips_out_polvio); IP6STAT_INC(ip6s_cantforward); KEY_FREESP(&sp); if (mcopy) { #if 0 /* XXX: what icmp ? */ #else m_freem(mcopy); #endif } m_freem(m); return; case IPSEC_POLICY_BYPASS: case IPSEC_POLICY_NONE: /* no need to do IPsec. */ KEY_FREESP(&sp); goto skip_ipsec; case IPSEC_POLICY_IPSEC: if (sp->req == NULL) { /* XXX should be panic ? */ printf("ip6_forward: No IPsec request specified.\n"); IP6STAT_INC(ip6s_cantforward); KEY_FREESP(&sp); if (mcopy) { #if 0 /* XXX: what icmp ? */ #else m_freem(mcopy); #endif } m_freem(m); return; } /* do IPsec */ break; case IPSEC_POLICY_ENTRUST: default: /* should be panic ?? */ printf("ip6_forward: Invalid policy found. %d\n", sp->policy); KEY_FREESP(&sp); goto skip_ipsec; } { struct ipsecrequest *isr = NULL; /* * when the kernel forwards a packet, it is not proper to apply * IPsec transport mode to the packet is not proper. this check * avoid from this. * at present, if there is even a transport mode SA request in the * security policy, the kernel does not apply IPsec to the packet. * this check is not enough because the following case is valid. * ipsec esp/tunnel/xxx-xxx/require esp/transport//require; */ for (isr = sp->req; isr; isr = isr->next) { if (isr->saidx.mode == IPSEC_MODE_ANY) goto doipsectunnel; if (isr->saidx.mode == IPSEC_MODE_TUNNEL) goto doipsectunnel; } /* * if there's no need for tunnel mode IPsec, skip. */ if (!isr) goto skip_ipsec; doipsectunnel: /* * All the extension headers will become inaccessible * (since they can be encrypted). * Don't panic, we need no more updates to extension headers * on inner IPv6 packet (since they are now encapsulated). * * IPv6 [ESP|AH] IPv6 [extension headers] payload */ /* * If we need to encapsulate the packet, do it here * ipsec6_proces_packet will send the packet using ip6_output */ error = ipsec6_process_packet(m, sp->req); KEY_FREESP(&sp); if (error == EJUSTRETURN) { /* * We had a SP with a level of 'use' and no SA. We * will just continue to process the packet without * IPsec processing. */ error = 0; goto skip_ipsec; } if (error) { /* mbuf is already reclaimed in ipsec6_process_packet. */ switch (error) { case EHOSTUNREACH: case ENETUNREACH: case EMSGSIZE: case ENOBUFS: case ENOMEM: break; default: printf("ip6_output (ipsec): error code %d\n", error); /* FALLTHROUGH */ case ENOENT: /* don't show these error codes to the user */ break; } IP6STAT_INC(ip6s_cantforward); if (mcopy) { #if 0 /* XXX: what icmp ? */ #else m_freem(mcopy); #endif } return; } else { /* * In the FAST IPSec case we have already * re-injected the packet and it has been freed * by the ipsec_done() function. So, just clean * up after ourselves. */ m = NULL; goto freecopy; } } skip_ipsec: #endif again: bzero(&rin6, sizeof(struct route_in6)); dst = (struct sockaddr_in6 *)&rin6.ro_dst; dst->sin6_len = sizeof(struct sockaddr_in6); dst->sin6_family = AF_INET6; dst->sin6_addr = ip6->ip6_dst; again2: rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m)); if (rin6.ro_rt != NULL) RT_UNLOCK(rin6.ro_rt); else { IP6STAT_INC(ip6s_noroute); in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); if (mcopy) { icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE, 0); } goto bad; } rt = rin6.ro_rt; /* * Source scope check: if a packet can't be delivered to its * destination for the reason that the destination is beyond the scope * of the source address, discard the packet and return an icmp6 * destination unreachable error with Code 2 (beyond scope of source * address). We use a local copy of ip6_src, since in6_setscope() * will possibly modify its first argument. * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] */ src_in6 = ip6->ip6_src; if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { /* XXX: this should not happen */ IP6STAT_INC(ip6s_cantforward); IP6STAT_INC(ip6s_badscope); goto bad; } if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { IP6STAT_INC(ip6s_cantforward); IP6STAT_INC(ip6s_badscope); goto bad; } if (inzone != outzone) { IP6STAT_INC(ip6s_cantforward); IP6STAT_INC(ip6s_badscope); in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { V_ip6_log_time = time_uptime; log(LOG_DEBUG, "cannot forward " "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", ip6_sprintf(ip6bufs, &ip6->ip6_src), ip6_sprintf(ip6bufd, &ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); } if (mcopy) icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_BEYONDSCOPE, 0); goto bad; } /* * Destination scope check: if a packet is going to break the scope * zone of packet's destination address, discard it. This case should * usually be prevented by appropriately-configured routing table, but * we need an explicit check because we may mistakenly forward the * packet to a different zone by (e.g.) a default route. */ dst_in6 = ip6->ip6_dst; if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || inzone != outzone) { IP6STAT_INC(ip6s_cantforward); IP6STAT_INC(ip6s_badscope); goto bad; } if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); if (mcopy) { u_long mtu; #ifdef IPSEC struct secpolicy *sp; int ipsecerror; size_t ipsechdrsiz; #endif /* IPSEC */ mtu = IN6_LINKMTU(rt->rt_ifp); #ifdef IPSEC /* * When we do IPsec tunnel ingress, we need to play * with the link value (decrement IPsec header size * from mtu value). The code is much simpler than v4 * case, as we have the outgoing interface for * encapsulated packet as "rt->rt_ifp". */ sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, IP_FORWARDING, &ipsecerror); if (sp) { ipsechdrsiz = ipsec_hdrsiz(mcopy, IPSEC_DIR_OUTBOUND, NULL); if (ipsechdrsiz < mtu) mtu -= ipsechdrsiz; } /* * if mtu becomes less than minimum MTU, * tell minimum MTU (and I'll need to fragment it). */ if (mtu < IPV6_MMTU) mtu = IPV6_MMTU; #endif /* IPSEC */ icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); } goto bad; } if (rt->rt_flags & RTF_GATEWAY) dst = (struct sockaddr_in6 *)rt->rt_gateway; /* * If we are to forward the packet using the same interface * as one we got the packet from, perhaps we should send a redirect * to sender to shortcut a hop. * Only send redirect if source is sending directly to us, * and if packet was not source routed (or has any options). * Also, don't send redirect if forwarding using a route * modified by a redirect. */ if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { /* * If the incoming interface is equal to the outgoing * one, and the link attached to the interface is * point-to-point, then it will be highly probable * that a routing loop occurs. Thus, we immediately * drop the packet and send an ICMPv6 error message. * * type/code is based on suggestion by Rich Draves. * not sure if it is the best pick. */ icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0); goto bad; } type = ND_REDIRECT; } /* * Fake scoped addresses. Note that even link-local source or * destinaion can appear, if the originating node just sends the * packet to us (without address resolution for the destination). * Since both icmp6_error and icmp6_redirect_output fill the embedded * link identifiers, we can do this stuff after making a copy for * returning an error. */ if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { /* * See corresponding comments in ip6_output. * XXX: but is it possible that ip6_forward() sends a packet * to a loopback interface? I don't think so, and thus * I bark here. ([email protected]) * XXX: it is common to route invalid packets to loopback. * also, the codepath will be visited on use of ::1 in * rthdr. (itojun) */ #if 1 if (0) #else if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) #endif { printf("ip6_forward: outgoing interface is loopback. " "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", ip6_sprintf(ip6bufs, &ip6->ip6_src), ip6_sprintf(ip6bufd, &ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); } /* we can just use rcvif in forwarding. */ origifp = m->m_pkthdr.rcvif; } else origifp = rt->rt_ifp; /* * clear embedded scope identifiers if necessary. * in6_clearscope will touch the addresses only when necessary. */ in6_clearscope(&ip6->ip6_src); in6_clearscope(&ip6->ip6_dst); /* Jump over all PFIL processing if hooks are not active. */ if (!PFIL_HOOKED(&V_inet6_pfil_hook)) goto pass; odst = ip6->ip6_dst; /* Run through list of hooks for output packets. */ error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); if (error != 0 || m == NULL) goto freecopy; /* consumed by filter */ ip6 = mtod(m, struct ip6_hdr *); /* See if destination IP address was changed by packet filter. */ if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) { m->m_flags |= M_SKIP_FIREWALL; /* If destination is now ourself drop to ip6_input(). */ if (in6_localip(&ip6->ip6_dst)) { m->m_flags |= M_FASTFWD_OURS; if (m->m_pkthdr.rcvif == NULL) m->m_pkthdr.rcvif = V_loif; if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { m->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; m->m_pkthdr.csum_data = 0xffff; } #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; #endif error = netisr_queue(NETISR_IPV6, m); goto out; } else goto again; /* Redo the routing table lookup. */ } /* See if local, if yes, send it to netisr. */ if (m->m_flags & M_FASTFWD_OURS) { if (m->m_pkthdr.rcvif == NULL) m->m_pkthdr.rcvif = V_loif; if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { m->m_pkthdr.csum_flags |= CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; m->m_pkthdr.csum_data = 0xffff; } #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; #endif error = netisr_queue(NETISR_IPV6, m); goto out; } /* Or forward to some other address? */ if ((m->m_flags & M_IP6_NEXTHOP) && (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { dst = (struct sockaddr_in6 *)&rin6.ro_dst; bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6)); m->m_flags |= M_SKIP_FIREWALL; m->m_flags &= ~M_IP6_NEXTHOP; m_tag_delete(m, fwd_tag); goto again2; } pass: error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); if (error) { in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); IP6STAT_INC(ip6s_cantforward); } else { IP6STAT_INC(ip6s_forward); in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); if (type) IP6STAT_INC(ip6s_redirectsent); else { if (mcopy) goto freecopy; } } if (mcopy == NULL) goto out; switch (error) { case 0: if (type == ND_REDIRECT) { icmp6_redirect_output(mcopy, rt); goto out; } goto freecopy; case EMSGSIZE: /* xxx MTU is constant in PPP? */ goto freecopy; case ENOBUFS: /* Tell source to slow down like source quench in IP? */ goto freecopy; case ENETUNREACH: /* shouldn't happen, checked above */ case EHOSTUNREACH: case ENETDOWN: case EHOSTDOWN: default: type = ICMP6_DST_UNREACH; code = ICMP6_DST_UNREACH_ADDR; break; } icmp6_error(mcopy, type, code, 0); goto out; freecopy: m_freem(mcopy); goto out; bad: m_freem(m); out: if (rt != NULL) RTFREE(rt); }
void ip6_forward(struct mbuf *m, int srcrt) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct sockaddr_in6 *dst; struct rtentry *rt; int error, type = 0, code = 0; struct mbuf *mcopy = NULL; struct ifnet *origifp; /* maybe unnecessary */ #ifdef IPSEC struct secpolicy *sp = NULL; #endif #ifdef IPSEC /* * Check AH/ESP integrity. */ /* * Don't increment ip6s_cantforward because this is the check * before forwarding packet actually. */ if (ipsec6_in_reject(m, NULL)) { #if !defined(FAST_IPSEC) ipsec6stat.in_polvio++; #endif m_freem(m); return; } #endif /* IPSEC */ /* * Do not forward packets to multicast destination (should be handled * by ip6_mforward(). * Do not forward packets with unspecified source. It was discussed * in July 2000, on ipngwg mailing list. */ if ((m->m_flags & (M_BCAST | M_MCAST)) != 0 || IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { ip6stat.ip6s_cantforward++; /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ if (ip6_log_time + ip6_log_interval < time_second) { ip6_log_time = time_second; log(LOG_DEBUG, "cannot forward " "from %s to %s nxt %d received on %s\n", ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif)); } m_freem(m); return; } if (ip6->ip6_hlim <= IPV6_HLIMDEC) { /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ icmp6_error(m, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT, 0); return; } ip6->ip6_hlim -= IPV6_HLIMDEC; /* * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - * size of IPv6 + ICMPv6 headers) bytes of the packet in case * we need to generate an ICMP6 message to the src. * Thanks to M_EXT, in most cases copy will not occur. * * It is important to save it before IPsec processing as IPsec * processing may modify the mbuf. */ mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); #ifdef IPSEC /* get a security policy for this packet */ sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, &error); if (sp == NULL) { ipsec6stat.out_inval++; ip6stat.ip6s_cantforward++; if (mcopy) { #if 0 /* XXX: what icmp ? */ #else m_freem(mcopy); #endif } m_freem(m); return; } error = 0; /* check policy */ switch (sp->policy) { case IPSEC_POLICY_DISCARD: /* * This packet is just discarded. */ ipsec6stat.out_polvio++; ip6stat.ip6s_cantforward++; key_freesp(sp); if (mcopy) { #if 0 /* XXX: what icmp ? */ #else m_freem(mcopy); #endif } m_freem(m); return; case IPSEC_POLICY_BYPASS: case IPSEC_POLICY_NONE: /* no need to do IPsec. */ key_freesp(sp); goto skip_ipsec; case IPSEC_POLICY_IPSEC: if (sp->req == NULL) { /* XXX should be panic ? */ kprintf("ip6_forward: No IPsec request specified.\n"); ip6stat.ip6s_cantforward++; key_freesp(sp); if (mcopy) { #if 0 /* XXX: what icmp ? */ #else m_freem(mcopy); #endif } m_freem(m); return; } /* do IPsec */ break; case IPSEC_POLICY_ENTRUST: default: /* should be panic ?? */ kprintf("ip6_forward: Invalid policy found. %d\n", sp->policy); key_freesp(sp); goto skip_ipsec; } { struct ipsec_output_state state; /* * All the extension headers will become inaccessible * (since they can be encrypted). * Don't panic, we need no more updates to extension headers * on inner IPv6 packet (since they are now encapsulated). * * IPv6 [ESP|AH] IPv6 [extension headers] payload */ bzero(&state, sizeof(state)); state.m = m; state.ro = NULL; /* update at ipsec6_output_tunnel() */ state.dst = NULL; /* update at ipsec6_output_tunnel() */ error = ipsec6_output_tunnel(&state, sp, 0); m = state.m; key_freesp(sp); if (error) { /* mbuf is already reclaimed in ipsec6_output_tunnel. */ switch (error) { case EHOSTUNREACH: case ENETUNREACH: case EMSGSIZE: case ENOBUFS: case ENOMEM: break; default: kprintf("ip6_output (ipsec): error code %d\n", error); /* fall through */ case ENOENT: /* don't show these error codes to the user */ break; } ip6stat.ip6s_cantforward++; if (mcopy) { #if 0 /* XXX: what icmp ? */ #else m_freem(mcopy); #endif } m_freem(m); return; } } skip_ipsec: #endif /* IPSEC */ dst = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; if (!srcrt) { /* * ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst */ if (ip6_forward_rt.ro_rt == NULL || !(ip6_forward_rt.ro_rt->rt_flags & RTF_UP)) { if (ip6_forward_rt.ro_rt) { RTFREE(ip6_forward_rt.ro_rt); ip6_forward_rt.ro_rt = 0; } /* this probably fails but give it a try again */ rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); } if (ip6_forward_rt.ro_rt == NULL) { ip6stat.ip6s_noroute++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); if (mcopy) { icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE, 0); } m_freem(m); return; } } else if ((rt = ip6_forward_rt.ro_rt) == NULL || !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) { if (ip6_forward_rt.ro_rt) { RTFREE(ip6_forward_rt.ro_rt); ip6_forward_rt.ro_rt = 0; } bzero(dst, sizeof(*dst)); dst->sin6_len = sizeof(struct sockaddr_in6); dst->sin6_family = AF_INET6; dst->sin6_addr = ip6->ip6_dst; rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); if (ip6_forward_rt.ro_rt == NULL) { ip6stat.ip6s_noroute++; in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); if (mcopy) { icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE, 0); } m_freem(m); return; } } rt = ip6_forward_rt.ro_rt; /* * Scope check: if a packet can't be delivered to its destination * for the reason that the destination is beyond the scope of the * source address, discard the packet and return an icmp6 destination * unreachable error with Code 2 (beyond scope of source address). * [draft-ietf-ipngwg-icmp-v3-02.txt, Section 3.1] */ if (in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_src) != in6_addr2scopeid(rt->rt_ifp, &ip6->ip6_src)) { ip6stat.ip6s_cantforward++; ip6stat.ip6s_badscope++; in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); if (ip6_log_time + ip6_log_interval < time_second) { ip6_log_time = time_second; log(LOG_DEBUG, "cannot forward " "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); } if (mcopy) icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_BEYONDSCOPE, 0); m_freem(m); return; } if (m->m_pkthdr.len > rt->rt_ifp->if_mtu) { in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); if (mcopy) { u_long mtu; #ifdef IPSEC struct secpolicy *sp; int ipsecerror; size_t ipsechdrsiz; #endif mtu = rt->rt_ifp->if_mtu; #ifdef IPSEC /* * When we do IPsec tunnel ingress, we need to play * with if_mtu value (decrement IPsec header size * from mtu value). The code is much simpler than v4 * case, as we have the outgoing interface for * encapsulated packet as "rt->rt_ifp". */ sp = ipsec6_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, IP_FORWARDING, &ipsecerror); if (sp) { ipsechdrsiz = ipsec6_hdrsiz(mcopy, IPSEC_DIR_OUTBOUND, NULL); if (ipsechdrsiz < mtu) mtu -= ipsechdrsiz; } /* * if mtu becomes less than minimum MTU, * tell minimum MTU (and I'll need to fragment it). */ if (mtu < IPV6_MMTU) mtu = IPV6_MMTU; #endif icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); } m_freem(m); return; } if (rt->rt_flags & RTF_GATEWAY) dst = (struct sockaddr_in6 *)rt->rt_gateway; /* * If we are to forward the packet using the same interface * as one we got the packet from, perhaps we should send a redirect * to sender to shortcut a hop. * Only send redirect if source is sending directly to us, * and if packet was not source routed (or has any options). * Also, don't send redirect if forwarding using a route * modified by a redirect. */ if (rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && (rt->rt_flags & (RTF_DYNAMIC | RTF_MODIFIED)) == 0) { if (rt->rt_ifp->if_flags & IFF_POINTOPOINT) { /* * If the incoming interface is equal to the outgoing * one, and the link attached to the interface is * point-to-point, then it will be highly probable * that a routing loop occurs. Thus, we immediately * drop the packet and send an ICMPv6 error message. * * type/code is based on suggestion by Rich Draves. * not sure if it is the best pick. */ icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0); m_freem(m); return; } type = ND_REDIRECT; } /* * Check with the firewall... */ if (ip6_fw_enable && ip6_fw_chk_ptr) { u_short port = 0; /* If ipfw says divert, we have to just drop packet */ if ((*ip6_fw_chk_ptr)(&ip6, rt->rt_ifp, &port, &m)) { m_freem(m); goto freecopy; } if (!m) goto freecopy; } /* * Fake scoped addresses. Note that even link-local source or * destinaion can appear, if the originating node just sends the * packet to us (without address resolution for the destination). * Since both icmp6_error and icmp6_redirect_output fill the embedded * link identifiers, we can do this stuff after making a copy for * returning an error. */ if (rt->rt_ifp->if_flags & IFF_LOOPBACK) { /* * See corresponding comments in ip6_output. * XXX: but is it possible that ip6_forward() sends a packet * to a loopback interface? I don't think so, and thus * I bark here. ([email protected]) * XXX: it is common to route invalid packets to loopback. * also, the codepath will be visited on use of ::1 in * rthdr. (itojun) */ #if 1 if (0) #else if ((rt->rt_flags & (RTF_BLACKHOLE | RTF_REJECT)) == 0) #endif { kprintf("ip6_forward: outgoing interface is loopback. " "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); } /* we can just use rcvif in forwarding. */ origifp = m->m_pkthdr.rcvif; } else origifp = rt->rt_ifp; /* * clear embedded scope identifiers if necessary. * in6_clearscope will touch the addresses only when necessary. */ in6_clearscope(&ip6->ip6_src); in6_clearscope(&ip6->ip6_dst); /* * Run through list of hooks for output packets. */ if (pfil_has_hooks(&inet6_pfil_hook)) { error = pfil_run_hooks(&inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT); if (error != 0) goto senderr; if (m == NULL) goto freecopy; ip6 = mtod(m, struct ip6_hdr *); }
/* * One helper hook function is used by any hook points. * + from hhook_type we can determine the packet direction: * HHOOK_TYPE_IPSEC_IN or HHOOK_TYPE_IPSEC_OUT; * + from hhook_id we can determine address family: AF_INET or AF_INET6; * + udata contains pointer to enc_softc; * + ctx_data contains pointer to struct ipsec_ctx_data. */ static int enc_hhook(int32_t hhook_type, int32_t hhook_id, void *udata, void *ctx_data, void *hdata, struct osd *hosd) { struct enchdr hdr; struct ipsec_ctx_data *ctx; struct enc_softc *sc; struct ifnet *ifp, *rcvif; struct pfil_head *ph; int pdir; sc = (struct enc_softc *)udata; ifp = sc->sc_ifp; if ((ifp->if_flags & IFF_UP) == 0) return (0); ctx = (struct ipsec_ctx_data *)ctx_data; /* XXX: wrong hook point was used by caller? */ if (ctx->af != hhook_id) return (EPFNOSUPPORT); if (((hhook_type == HHOOK_TYPE_IPSEC_IN && (ctx->enc & V_bpf_mask_in) != 0) || (hhook_type == HHOOK_TYPE_IPSEC_OUT && (ctx->enc & V_bpf_mask_out) != 0)) && bpf_peers_present(ifp->if_bpf) != 0) { hdr.af = ctx->af; hdr.spi = ctx->sav->spi; hdr.flags = 0; if (ctx->sav->alg_enc != SADB_EALG_NONE) hdr.flags |= M_CONF; if (ctx->sav->alg_auth != SADB_AALG_NONE) hdr.flags |= M_AUTH; bpf_mtap2(ifp->if_bpf, &hdr, sizeof(hdr), *ctx->mp); } switch (hhook_type) { case HHOOK_TYPE_IPSEC_IN: if (ctx->enc == IPSEC_ENC_BEFORE) { /* Do accounting only once */ if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); if_inc_counter(ifp, IFCOUNTER_IBYTES, (*ctx->mp)->m_pkthdr.len); } if ((ctx->enc & V_filter_mask_in) == 0) return (0); /* skip pfil processing */ pdir = PFIL_IN; break; case HHOOK_TYPE_IPSEC_OUT: if (ctx->enc == IPSEC_ENC_BEFORE) { /* Do accounting only once */ if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); if_inc_counter(ifp, IFCOUNTER_OBYTES, (*ctx->mp)->m_pkthdr.len); } if ((ctx->enc & V_filter_mask_out) == 0) return (0); /* skip pfil processing */ pdir = PFIL_OUT; break; default: return (EINVAL); } switch (hhook_id) { #ifdef INET case AF_INET: ph = &V_inet_pfil_hook; break; #endif #ifdef INET6 case AF_INET6: ph = &V_inet6_pfil_hook; break; #endif default: ph = NULL; } if (ph == NULL || !PFIL_HOOKED(ph)) return (0); /* Make a packet looks like it was received on enc(4) */ rcvif = (*ctx->mp)->m_pkthdr.rcvif; (*ctx->mp)->m_pkthdr.rcvif = ifp; if (pfil_run_hooks(ph, ctx->mp, ifp, pdir, NULL) != 0 || *ctx->mp == NULL) { *ctx->mp = NULL; /* consumed by filter */ return (EACCES); } (*ctx->mp)->m_pkthdr.rcvif = rcvif; return (0); }
static void ip6_input(netmsg_t msg) { struct mbuf *m = msg->packet.nm_packet; struct ip6_hdr *ip6; int off = sizeof(struct ip6_hdr), nest; u_int32_t plen; u_int32_t rtalert = ~0; int nxt, ours = 0, rh_present = 0; struct ifnet *deliverifp = NULL; struct in6_addr odst; int srcrt = 0; #ifdef IPSEC /* * should the inner packet be considered authentic? * see comment in ah4_input(). */ if (m) { m->m_flags &= ~M_AUTHIPHDR; m->m_flags &= ~M_AUTHIPDGM; } #endif /* * make sure we don't have onion peering information into m_aux. */ ip6_delaux(m); /* * mbuf statistics */ if (m->m_flags & M_EXT) { if (m->m_next) ip6stat.ip6s_mext2m++; else ip6stat.ip6s_mext1++; } else { #define M2MMAX NELEM(ip6stat.ip6s_m2m) 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 /* * 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; n = m_getb(m->m_pkthdr.len, MB_DONTWAIT, MT_HEADER, M_PKTHDR); if (n == NULL) goto bad; M_MOVE_PKTHDR(n, m); 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_VOIDRET(m, 0, sizeof(struct ip6_hdr)); #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) { ip6stat.ip6s_toosmall++; in6_ifstat_inc(inifp, ifs6_in_hdrerr); goto bad2; } } 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; } /* * 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. */ if (pfil_has_hooks(&inet6_pfil_hook)) { odst = ip6->ip6_dst; if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN)) { goto bad2; } if (m == NULL) /* consumed by filter */ goto bad2; ip6 = mtod(m, struct ip6_hdr *); srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst); }
static inline int ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, struct inpcb *inp, struct sockaddr_in *dst, int *fibnum, int *error) { struct m_tag *fwd_tag = NULL; struct mbuf *m; struct in_addr odst; struct ip *ip; m = *mp; ip = mtod(m, struct ip *); /* Run through list of hooks for output packets. */ odst.s_addr = ip->ip_dst.s_addr; *error = pfil_run_hooks(&V_inet_pfil_hook, mp, ifp, PFIL_OUT, inp); m = *mp; if ((*error) != 0 || m == NULL) return 1; /* Finished */ ip = mtod(m, struct ip *); /* See if destination IP address was changed by packet filter. */ if (odst.s_addr != ip->ip_dst.s_addr) { m->m_flags |= M_SKIP_FIREWALL; /* If destination is now ourself drop to ip_input(). */ if (in_localip(ip->ip_dst)) { m->m_flags |= M_FASTFWD_OURS; if (m->m_pkthdr.rcvif == NULL) m->m_pkthdr.rcvif = V_loif; if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR; m->m_pkthdr.csum_data = 0xffff; } m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED | CSUM_IP_VALID; #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP) m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; #endif *error = netisr_queue(NETISR_IP, m); return 1; /* Finished */ } bzero(dst, sizeof(*dst)); dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = ip->ip_dst; return -1; /* Reloop */ } /* See if fib was changed by packet filter. */ if ((*fibnum) != M_GETFIB(m)) { m->m_flags |= M_SKIP_FIREWALL; *fibnum = M_GETFIB(m); return -1; /* Reloop for FIB change */ } /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */ if (m->m_flags & M_FASTFWD_OURS) { if (m->m_pkthdr.rcvif == NULL) m->m_pkthdr.rcvif = V_loif; if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) { m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR; m->m_pkthdr.csum_data = 0xffff; } #ifdef SCTP if (m->m_pkthdr.csum_flags & CSUM_SCTP) m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; #endif m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED | CSUM_IP_VALID; *error = netisr_queue(NETISR_IP, m); return 1; /* Finished */ } /* Or forward to some other address? */ if ((m->m_flags & M_IP_NEXTHOP) && ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) { bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in)); m->m_flags |= M_SKIP_FIREWALL; m->m_flags &= ~M_IP_NEXTHOP; m_tag_delete(m, fwd_tag); return -1; /* Reloop for CHANGE of dst */ } return 0; }
int ipsec_filter(struct mbuf **mp, int dir, int flags) { int error, i; struct ip *ip; KASSERT(encif != NULL, ("%s: encif is null", __func__)); KASSERT(flags & (ENC_IN|ENC_OUT), ("%s: invalid flags: %04x", __func__, flags)); if ((encif->if_drv_flags & IFF_DRV_RUNNING) == 0) return (0); if (flags & ENC_IN) { if ((flags & ipsec_filter_mask_in) == 0) return (0); } else { if ((flags & ipsec_filter_mask_out) == 0) return (0); } /* Skip pfil(9) if no filters are loaded */ if (1 #ifdef INET && !PFIL_HOOKED(&V_inet_pfil_hook) #endif #ifdef INET6 && !PFIL_HOOKED(&V_inet6_pfil_hook) #endif ) { return (0); } i = min((*mp)->m_pkthdr.len, max_protohdr); if ((*mp)->m_len < i) { *mp = m_pullup(*mp, i); if (*mp == NULL) { printf("%s: m_pullup failed\n", __func__); return (-1); } } error = 0; ip = mtod(*mp, struct ip *); switch (ip->ip_v) { #ifdef INET case 4: /* * before calling the firewall, swap fields the same as * IP does. here we assume the header is contiguous */ ip->ip_len = ntohs(ip->ip_len); ip->ip_off = ntohs(ip->ip_off); error = pfil_run_hooks(&V_inet_pfil_hook, mp, encif, dir, NULL); if (*mp == NULL || error != 0) break; /* restore byte ordering */ ip = mtod(*mp, struct ip *); ip->ip_len = htons(ip->ip_len); ip->ip_off = htons(ip->ip_off); break; #endif #ifdef INET6 case 6: error = pfil_run_hooks(&V_inet6_pfil_hook, mp, encif, dir, NULL); break; #endif default: printf("%s: unknown IP version\n", __func__); } /* * If the mbuf was consumed by the filter for requeueing (dummynet, etc) * then error will be zero but we still want to return an error to our * caller so the null mbuf isn't forwarded further. */ if (*mp == NULL && error == 0) return (-1); /* Consumed by the filter */ if (*mp == NULL) return (error); if (error != 0) goto bad; return (error); bad: m_freem(*mp); *mp = NULL; return (error); }
void ip6_forward(struct mbuf *m, int srcrt) { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); const struct sockaddr_in6 *dst; struct rtentry *rt; int error = 0, type = 0, code = 0; struct mbuf *mcopy = NULL; struct ifnet *origifp; /* maybe unnecessary */ uint32_t inzone, outzone; struct in6_addr src_in6, dst_in6; #ifdef IPSEC int needipsec = 0; struct secpolicy *sp = NULL; #endif /* * Clear any in-bound checksum flags for this packet. */ m->m_pkthdr.csum_flags = 0; /* * Do not forward packets to multicast destination (should be handled * by ip6_mforward(). * Do not forward packets with unspecified source. It was discussed * in July 2000, on ipngwg mailing list. */ if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { ip6_cantforward(ip6, m->m_pkthdr.rcvif, NULL, ((m->m_flags & (M_BCAST|M_MCAST)) != 0) ? "bcast/mcast" : IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ? "mcast/dst" : "unspec/src"); m_freem(m); return; } if (ip6->ip6_hlim <= IPV6_HLIMDEC) { /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ icmp6_error(m, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT, 0); return; } ip6->ip6_hlim -= IPV6_HLIMDEC; /* * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - * size of IPv6 + ICMPv6 headers) bytes of the packet in case * we need to generate an ICMP6 message to the src. * Thanks to M_EXT, in most cases copy will not occur. * * It is important to save it before IPsec processing as IPsec * processing may modify the mbuf. */ mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); #ifdef IPSEC if (ipsec_used) { /* Check the security policy (SP) for the packet */ sp = ipsec6_check_policy(m, NULL, 0, &needipsec, &error); if (error != 0) { /* * Hack: -EINVAL is used to signal that a packet * should be silently discarded. This is typically * because we asked key management for an SA and * it was delayed (e.g. kicked up to IKE). */ if (error == -EINVAL) error = 0; goto freecopy; } } #endif /* IPSEC */ if (srcrt) { union { struct sockaddr dst; struct sockaddr_in6 dst6; } u; sockaddr_in6_init(&u.dst6, &ip6->ip6_dst, 0, 0, 0); if ((rt = rtcache_lookup(&ip6_forward_rt, &u.dst)) == NULL) { IP6_STATINC(IP6_STAT_NOROUTE); /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */ if (mcopy) { icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE, 0); } m_freem(m); return; } } else if ((rt = rtcache_validate(&ip6_forward_rt)) == NULL && (rt = rtcache_update(&ip6_forward_rt, 1)) == NULL) { /* * rtcache_getdst(ip6_forward_rt)->sin6_addr was equal to * ip6->ip6_dst */ IP6_STATINC(IP6_STAT_NOROUTE); /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */ if (mcopy) { icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOROUTE, 0); } m_freem(m); return; } dst = satocsin6(rtcache_getdst(&ip6_forward_rt)); /* * Source scope check: if a packet can't be delivered to its * destination for the reason that the destination is beyond the scope * of the source address, discard the packet and return an icmp6 * destination unreachable error with Code 2 (beyond scope of source * address). We use a local copy of ip6_src, since in6_setscope() * will possibly modify its first argument. * [draft-ietf-ipngwg-icmp-v3-07, Section 3.1] */ src_in6 = ip6->ip6_src; inzone = outzone = ~0; if (in6_setscope(&src_in6, rt->rt_ifp, &outzone) != 0 || in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone) != 0 || inzone != outzone) { ip6_cantforward(ip6, m->m_pkthdr.rcvif, rt->rt_ifp, "src[%s] inzone %d outzone %d", in6_getscopename(&ip6->ip6_src), inzone, outzone); if (mcopy) icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_BEYONDSCOPE, 0); m_freem(m); return; } #ifdef IPSEC /* * If we need to encapsulate the packet, do it here * ipsec6_proces_packet will send the packet using ip6_output */ if (needipsec) { int s = splsoftnet(); error = ipsec6_process_packet(m, sp->req); splx(s); if (mcopy) goto freecopy; } #endif /* * Destination scope check: if a packet is going to break the scope * zone of packet's destination address, discard it. This case should * usually be prevented by appropriately-configured routing table, but * we need an explicit check because we may mistakenly forward the * packet to a different zone by (e.g.) a default route. */ dst_in6 = ip6->ip6_dst; inzone = outzone = ~0; if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || inzone != outzone) { ip6_cantforward(ip6, m->m_pkthdr.rcvif, rt->rt_ifp, "dst[%s] inzone %d outzone %d", in6_getscopename(&ip6->ip6_dst), inzone, outzone); if (mcopy) icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_BEYONDSCOPE, 0); m_freem(m); return; } if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); if (mcopy) { u_long mtu; mtu = IN6_LINKMTU(rt->rt_ifp); icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); } m_freem(m); return; } if (rt->rt_flags & RTF_GATEWAY) dst = (struct sockaddr_in6 *)rt->rt_gateway; /* * If we are to forward the packet using the same interface * as one we got the packet from, perhaps we should send a redirect * to sender to shortcut a hop. * Only send redirect if source is sending directly to us, * and if packet was not source routed (or has any options). * Also, don't send redirect if forwarding using a route * modified by a redirect. */ if (rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && ip6_sendredirects && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) && nd6_is_addr_neighbor( satocsin6(rtcache_getdst(&ip6_forward_rt)), rt->rt_ifp)) { /* * If the incoming interface is equal to the outgoing * one, the link attached to the interface is * point-to-point, and the IPv6 destination is * regarded as on-link on the link, then it will be * highly probable that the destination address does * not exist on the link and that the packet is going * to loop. Thus, we immediately drop the packet and * send an ICMPv6 error message. * For other routing loops, we dare to let the packet * go to the loop, so that a remote diagnosing host * can detect the loop by traceroute. * type/code is based on suggestion by Rich Draves. * not sure if it is the best pick. */ icmp6_error(mcopy, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0); m_freem(m); return; } type = ND_REDIRECT; } /* * Fake scoped addresses. Note that even link-local source or * destinaion can appear, if the originating node just sends the * packet to us (without address resolution for the destination). * Since both icmp6_error and icmp6_redirect_output fill the embedded * link identifiers, we can do this stuff after making a copy for * returning an error. */ if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { /* * See corresponding comments in ip6_output. * XXX: but is it possible that ip6_forward() sends a packet * to a loopback interface? I don't think so, and thus * I bark here. ([email protected]) * XXX: it is common to route invalid packets to loopback. * also, the codepath will be visited on use of ::1 in * rthdr. (itojun) */ #if 1 if (0) #else if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) #endif { printf("ip6_forward: outgoing interface is loopback. " "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); } /* we can just use rcvif in forwarding. */ origifp = m->m_pkthdr.rcvif; } else origifp = rt->rt_ifp; /* * clear embedded scope identifiers if necessary. * in6_clearscope will touch the addresses only when necessary. */ in6_clearscope(&ip6->ip6_src); in6_clearscope(&ip6->ip6_dst); /* * Run through list of hooks for output packets. */ if ((error = pfil_run_hooks(inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT)) != 0) goto senderr; if (m == NULL) goto freecopy; ip6 = mtod(m, struct ip6_hdr *); error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); if (error) { in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); IP6_STATINC(IP6_STAT_CANTFORWARD); } else { IP6_STATINC(IP6_STAT_FORWARD); in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); if (type) IP6_STATINC(IP6_STAT_REDIRECTSENT); else { #ifdef GATEWAY if (m->m_flags & M_CANFASTFWD) ip6flow_create(&ip6_forward_rt, m); #endif if (mcopy) goto freecopy; } } senderr: if (mcopy == NULL) return; switch (error) { case 0: if (type == ND_REDIRECT) { icmp6_redirect_output(mcopy, rt); return; } goto freecopy; case EMSGSIZE: /* xxx MTU is constant in PPP? */ goto freecopy; case ENOBUFS: /* Tell source to slow down like source quench in IP? */ goto freecopy; case ENETUNREACH: /* shouldn't happen, checked above */ case EHOSTUNREACH: case ENETDOWN: case EHOSTDOWN: default: type = ICMP6_DST_UNREACH; code = ICMP6_DST_UNREACH_ADDR; break; } icmp6_error(mcopy, type, code, 0); return; freecopy: m_freem(mcopy); return; }
struct mbuf* ip6_tryforward(struct mbuf *m) { struct sockaddr_in6 dst; struct nhop6_basic nh; struct m_tag *fwd_tag; struct ip6_hdr *ip6; struct ifnet *rcvif; uint32_t plen; int error; /* * Fallback conditions to ip6_input for slow path processing. */ ip6 = mtod(m, struct ip6_hdr *); if (ip6->ip6_nxt == IPPROTO_HOPOPTS || IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst) || IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src) || IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) || in6_localip(&ip6->ip6_dst)) return (m); /* * 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. */ rcvif = m->m_pkthdr.rcvif; plen = ntohs(ip6->ip6_plen); if (plen == 0) { /* * Jumbograms must have hop-by-hop header and go via * slow path. */ IP6STAT_INC(ip6s_badoptions); goto dropin; } if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { IP6STAT_INC(ip6s_tooshort); in6_ifstat_inc(rcvif, ifs6_in_truncated); goto dropin; } 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); } /* * Hop limit. */ #ifdef IPSTEALTH if (!V_ip6stealth) #endif if (ip6->ip6_hlim <= IPV6_HLIMDEC) { icmp6_error(m, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT, 0); m = NULL; goto dropin; } bzero(&dst, sizeof(dst)); dst.sin6_family = AF_INET6; dst.sin6_len = sizeof(dst); dst.sin6_addr = ip6->ip6_dst; /* * Incoming packet firewall processing. */ if (!PFIL_HOOKED(&V_inet6_pfil_hook)) goto passin; if (pfil_run_hooks(&V_inet6_pfil_hook, &m, rcvif, PFIL_IN, NULL) != 0 || m == NULL) goto dropin; /* * If packet filter sets the M_FASTFWD_OURS flag, this means * that new destination or next hop is our local address. * So, we can just go back to ip6_input. * XXX: should we decrement ip6_hlim in such case? * * Also it can forward packet to another destination, e.g. * M_IP6_NEXTHOP flag is set and fwd_tag is attached to mbuf. */ if (m->m_flags & M_FASTFWD_OURS) return (m); ip6 = mtod(m, struct ip6_hdr *); if ((m->m_flags & M_IP6_NEXTHOP) && (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { /* * Now we will find route to forwarded by pfil destination. */ bcopy((fwd_tag + 1), &dst, sizeof(dst)); m->m_flags &= ~M_IP6_NEXTHOP; m_tag_delete(m, fwd_tag); } else { /* Update dst since pfil could change it */ dst.sin6_addr = ip6->ip6_dst; } passin: /* * Find route to destination. */ if (ip6_findroute(&nh, &dst, m) != 0) { m = NULL; in6_ifstat_inc(rcvif, ifs6_in_noroute); goto dropin; } /* * We used slow path processing for packets with scoped addresses. * So, scope checks aren't needed here. */ if (m->m_pkthdr.len > nh.nh_mtu) { in6_ifstat_inc(nh.nh_ifp, ifs6_in_toobig); icmp6_error(m, ICMP6_PACKET_TOO_BIG, 0, nh.nh_mtu); m = NULL; goto dropout; } /* * Outgoing packet firewall processing. */ if (!PFIL_HOOKED(&V_inet6_pfil_hook)) goto passout; if (pfil_run_hooks(&V_inet6_pfil_hook, &m, nh.nh_ifp, PFIL_OUT, NULL) != 0 || m == NULL) goto dropout; /* * If packet filter sets the M_FASTFWD_OURS flag, this means * that new destination or next hop is our local address. * So, we can just go back to ip6_input. * * Also it can forward packet to another destination, e.g. * M_IP6_NEXTHOP flag is set and fwd_tag is attached to mbuf. */ if (m->m_flags & M_FASTFWD_OURS) { /* * XXX: we did one hop and should decrement hop limit. But * now we are the destination and just don't pay attention. */ return (m); } /* * Again. A packet filter could change the destination address. */ ip6 = mtod(m, struct ip6_hdr *); if (m->m_flags & M_IP6_NEXTHOP) fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL); else fwd_tag = NULL; if (fwd_tag != NULL || !IN6_ARE_ADDR_EQUAL(&dst.sin6_addr, &ip6->ip6_dst)) { if (fwd_tag != NULL) { bcopy((fwd_tag + 1), &dst, sizeof(dst)); m->m_flags &= ~M_IP6_NEXTHOP; m_tag_delete(m, fwd_tag); } else dst.sin6_addr = ip6->ip6_dst; /* * Redo route lookup with new destination address */ if (ip6_findroute(&nh, &dst, m) != 0) { m = NULL; goto dropout; } } passout: #ifdef IPSTEALTH if (!V_ip6stealth) #endif { ip6->ip6_hlim -= IPV6_HLIMDEC; } m_clrprotoflags(m); /* Avoid confusing lower layers. */ IP_PROBE(send, NULL, NULL, ip6, nh.nh_ifp, NULL, ip6); /* * XXX: we need to use destination address with embedded scope * zone id, because LLTABLE uses such form of addresses for lookup. */ dst.sin6_addr = nh.nh_addr; if (IN6_IS_SCOPE_LINKLOCAL(&dst.sin6_addr)) dst.sin6_addr.s6_addr16[1] = htons(nh.nh_ifp->if_index & 0xffff); error = (*nh.nh_ifp->if_output)(nh.nh_ifp, m, (struct sockaddr *)&dst, NULL); if (error != 0) { in6_ifstat_inc(nh.nh_ifp, ifs6_out_discard); IP6STAT_INC(ip6s_cantforward); } else { in6_ifstat_inc(nh.nh_ifp, ifs6_out_forward); IP6STAT_INC(ip6s_forward); } return (NULL); dropin: in6_ifstat_inc(rcvif, ifs6_in_discard); goto drop; dropout: in6_ifstat_inc(nh.nh_ifp, ifs6_out_discard); drop: if (m != NULL) m_freem(m); return (NULL); }
/* * Ip input routine. Checksum and byte swap header. If fragmented * try to reassemble. Process options. Pass to next level. */ void ipintr() { register struct ip *ip; register struct mbuf *m; register struct ipq *fp; register struct in_ifaddr *ia; int hlen, s; int srcrt = 0; next: /* * Get next datagram off input queue and get IP header * in first mbuf. */ s = splimp(); IF_DEQUEUE(&ipintrq, m); splx(s); if (m == 0) return; #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("ipintr no HDR"); #endif /* * If no IP addresses have been set yet but the interfaces * are receiving, can't do anything with incoming packets yet. */ if (in_ifaddr == NULL) goto bad; ipstat.ips_total++; if (m->m_len < sizeof (struct ip) && (m = m_pullup(m, sizeof (struct ip))) == 0) { ipstat.ips_toosmall++; goto next; } ip = mtod(m, struct ip *); if (ip->ip_v != IPVERSION) { ipstat.ips_badvers++; goto bad; } hlen = ip->ip_hl << 2; if (hlen < sizeof(struct ip)) { /* minimum header length */ ipstat.ips_badhlen++; goto bad; } if (hlen > m->m_len) { if ((m = m_pullup(m, hlen)) == 0) { ipstat.ips_badhlen++; goto next; } ip = mtod(m, struct ip *); } /* if (ip->ip_sum = in_cksum(m, hlen)) { ipstat.ips_badsum++; goto bad; } */ /* * Convert fields to host representation. */ NTOHS(ip->ip_len); if (ip->ip_len < hlen) { ipstat.ips_badlen++; goto bad; } NTOHS(ip->ip_id); NTOHS(ip->ip_off); /* * Check that the amount of data in the buffers * is as at least much as the IP header would have us expect. * Trim mbufs if longer than we expect. * Drop packet if shorter than we expect. */ if (m->m_pkthdr.len < ip->ip_len) { ipstat.ips_tooshort++; goto bad; } if (m->m_pkthdr.len > ip->ip_len) { if (m->m_len == m->m_pkthdr.len) { m->m_len = ip->ip_len; m->m_pkthdr.len = ip->ip_len; } else m_adj(m, ip->ip_len - m->m_pkthdr.len); } #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. */ { struct in_addr odst; odst = ip->ip_dst; if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN) != 0) return; if (m == NULL) return; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; /* * XXX The setting of "srcrt" here is to prevent ip_forward() * from generating ICMP redirects for packets that have * been redirected by a hook back out on to the same LAN that * they came from and is not an indication that the packet * is being inffluenced by source routing options. This * allows things like * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp" * where tlp0 is both on the 1.1.1.0/24 network and is the * default route for hosts on 1.1.1.0/24. Of course this * also requires a "map tlp0 ..." to complete the story. * One might argue whether or not this kind of network config. * should be supported in this manner... */ srcrt = (odst.s_addr != ip->ip_dst.s_addr); } #endif /* PFIL_HOOKS */ /* * Process options and, if not destined for us, * ship it on. ip_dooptions returns 1 when an * error was detected (causing an icmp message * to be sent and the original packet to be freed). */ ip_nhops = 0; /* for source routed packets */ if (hlen > sizeof (struct ip) && ip_dooptions(m)) goto next; /* * Check our list of addresses, to see if the packet is for us. */ for (ia = in_ifaddr; ia; ia = ia->ia_next) { #define satosin(sa) ((struct sockaddr_in *)(sa)) if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr) goto ours; if ( #ifdef DIRECTED_BROADCAST ia->ia_ifp == m->m_pkthdr.rcvif && #endif (ia->ia_ifp->if_flags & IFF_BROADCAST)) { u_long t; if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == ip->ip_dst.s_addr) goto ours; if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr) goto ours; /* * Look for all-0's host part (old broadcast addr), * either for subnet or net. */ t = ntohl(ip->ip_dst.s_addr); if (t == ia->ia_subnet) goto ours; if (t == ia->ia_net) goto ours; } } if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { struct in_multi *inm; #ifdef MROUTING extern struct socket *ip_mrouter; if (ip_mrouter) { /* * 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 * ip_mforward() returns a non-zero value, the packet * must be discarded, else it may be accepted below. * * (The IP ident field is put in the same byte order * as expected when ip_mforward() is called from * ip_output().) */ ip->ip_id = htons(ip->ip_id); if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) { ipstat.ips_cantforward++; m_freem(m); goto next; } ip->ip_id = ntohs(ip->ip_id); /* * The process-level routing demon needs to receive * all multicast IGMP packets, whether or not this * host belongs to their destination groups. */ if (ip->ip_p == IPPROTO_IGMP) goto ours; ipstat.ips_forward++; } #endif /* * See if we belong to the destination multicast group on the * arrival interface. */ IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm); if (inm == NULL) { ipstat.ips_cantforward++; m_freem(m); goto next; } goto ours; } if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST) goto ours; if (ip->ip_dst.s_addr == INADDR_ANY) goto ours; /* * Not for us; forward if possible and desirable. */ if (ipforwarding == 0) { ipstat.ips_cantforward++; m_freem(m); } else ip_forward(m, 0); goto next; ours: /* * If offset or IP_MF are set, must reassemble. * Otherwise, nothing need be done. * (We could look in the reassembly queue to see * if the packet was previously fragmented, * but it's not worth the time; just let them time out.) */ if (ip->ip_off &~ IP_DF) { if (m->m_flags & M_EXT) { /* XXX */ if ((m = m_pullup(m, sizeof (struct ip))) == 0) { ipstat.ips_toosmall++; goto next; } ip = mtod(m, struct ip *); } /* * Look for queue of fragments * of this datagram. */ for (fp = ipq.next; fp != &ipq; fp = fp->next) if (ip->ip_id == fp->ipq_id && ip->ip_src.s_addr == fp->ipq_src.s_addr && ip->ip_dst.s_addr == fp->ipq_dst.s_addr && ip->ip_p == fp->ipq_p) goto found; fp = 0; found: /* * Adjust ip_len to not reflect header, * set ip_mff if more fragments are expected, * convert offset of this to bytes. */ ip->ip_len -= hlen; ((struct ipasfrag *)ip)->ipf_mff &= ~1; if (ip->ip_off & IP_MF) ((struct ipasfrag *)ip)->ipf_mff |= 1; ip->ip_off <<= 3; /* * If datagram marked as having more fragments * or if this is not the first fragment, * attempt reassembly; if it succeeds, proceed. */ if (((struct ipasfrag *)ip)->ipf_mff & 1 || ip->ip_off) { ipstat.ips_fragments++; ip = ip_reass((struct ipasfrag *)ip, fp); if (ip == 0) goto next; ipstat.ips_reassembled++; m = dtom(ip); } else if (fp) ip_freef(fp); } else