ip6_forward.c revision 78064
162587Sitojun/* $FreeBSD: head/sys/netinet6/ip6_forward.c 78064 2001-06-11 12:39:29Z ume $ */ 278064Sume/* $KAME: ip6_forward.c,v 1.69 2001/05/17 03:48:30 itojun Exp $ */ 362587Sitojun 453541Sshin/* 553541Sshin * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 653541Sshin * All rights reserved. 753541Sshin * 853541Sshin * Redistribution and use in source and binary forms, with or without 953541Sshin * modification, are permitted provided that the following conditions 1053541Sshin * are met: 1153541Sshin * 1. Redistributions of source code must retain the above copyright 1253541Sshin * notice, this list of conditions and the following disclaimer. 1353541Sshin * 2. Redistributions in binary form must reproduce the above copyright 1453541Sshin * notice, this list of conditions and the following disclaimer in the 1553541Sshin * documentation and/or other materials provided with the distribution. 1653541Sshin * 3. Neither the name of the project nor the names of its contributors 1753541Sshin * may be used to endorse or promote products derived from this software 1853541Sshin * without specific prior written permission. 1953541Sshin * 2053541Sshin * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 2153541Sshin * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2253541Sshin * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2353541Sshin * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 2453541Sshin * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2553541Sshin * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2653541Sshin * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2753541Sshin * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2853541Sshin * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2953541Sshin * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3053541Sshin * SUCH DAMAGE. 3153541Sshin */ 3253541Sshin 3362587Sitojun#include "opt_ip6fw.h" 3462587Sitojun#include "opt_inet.h" 3562587Sitojun#include "opt_inet6.h" 3655009Sshin#include "opt_ipsec.h" 3753541Sshin 3853541Sshin#include <sys/param.h> 3953541Sshin#include <sys/systm.h> 4078064Sume#include <sys/malloc.h> 4153541Sshin#include <sys/mbuf.h> 4253541Sshin#include <sys/domain.h> 4353541Sshin#include <sys/protosw.h> 4453541Sshin#include <sys/socket.h> 4553541Sshin#include <sys/errno.h> 4653541Sshin#include <sys/time.h> 4778064Sume#include <sys/kernel.h> 4853541Sshin#include <sys/syslog.h> 4953541Sshin 5053541Sshin#include <net/if.h> 5153541Sshin#include <net/route.h> 5253541Sshin 5353541Sshin#include <netinet/in.h> 5453541Sshin#include <netinet/in_var.h> 5578064Sume#include <netinet/in_systm.h> 5678064Sume#include <netinet/ip.h> 5762587Sitojun#include <netinet/ip_var.h> 5878064Sume#include <netinet6/in6_var.h> 5962587Sitojun#include <netinet/ip6.h> 6053541Sshin#include <netinet6/ip6_var.h> 6162587Sitojun#include <netinet/icmp6.h> 6253541Sshin#include <netinet6/nd6.h> 6353541Sshin 6478064Sume#include <netinet/in_pcb.h> 6578064Sume 6663256Sitojun#ifdef IPSEC 6753541Sshin#include <netinet6/ipsec.h> 6878064Sume#ifdef INET6 6962601Sitojun#include <netinet6/ipsec6.h> 7078064Sume#endif 7153541Sshin#include <netkey/key.h> 7263256Sitojun#endif /* IPSEC */ 7353541Sshin 7453541Sshin#include <netinet6/ip6_fw.h> 7553541Sshin 7653541Sshin#include <net/net_osdep.h> 7753541Sshin 7853541Sshinstruct route_in6 ip6_forward_rt; 7953541Sshin 8053541Sshin/* 8153541Sshin * Forward a packet. If some error occurs return the sender 8253541Sshin * an icmp packet. Note we can't always generate a meaningful 8353541Sshin * icmp message because icmp doesn't have a large enough repertoire 8453541Sshin * of codes and types. 8553541Sshin * 8653541Sshin * If not forwarding, just drop the packet. This could be confusing 8753541Sshin * if ipforwarding was zero but some routing protocol was advancing 8853541Sshin * us as a gateway to somewhere. However, we must let the routing 8953541Sshin * protocol deal with that. 9053541Sshin * 9153541Sshin */ 9253541Sshin 9353541Sshinvoid 9453541Sshinip6_forward(m, srcrt) 9553541Sshin struct mbuf *m; 9653541Sshin int srcrt; 9753541Sshin{ 9853541Sshin struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 9978064Sume struct sockaddr_in6 *dst; 10078064Sume struct rtentry *rt; 10153541Sshin int error, type = 0, code = 0; 10262587Sitojun struct mbuf *mcopy = NULL; 10362587Sitojun struct ifnet *origifp; /* maybe unnecessary */ 10463256Sitojun#ifdef IPSEC 10553541Sshin struct secpolicy *sp = NULL; 10653541Sshin#endif 10753541Sshin 10863256Sitojun#ifdef IPSEC 10953541Sshin /* 11053541Sshin * Check AH/ESP integrity. 11153541Sshin */ 11253541Sshin /* 11353541Sshin * Don't increment ip6s_cantforward because this is the check 11453541Sshin * before forwarding packet actually. 11553541Sshin */ 11653541Sshin if (ipsec6_in_reject(m, NULL)) { 11753541Sshin ipsec6stat.in_polvio++; 11853541Sshin m_freem(m); 11953541Sshin return; 12053541Sshin } 12163256Sitojun#endif /*IPSEC*/ 12253541Sshin 12378064Sume /* 12478064Sume * Do not forward packets to multicast destination (should be handled 12578064Sume * by ip6_mforward(). 12678064Sume * Do not forward packets with unspecified source. It was discussed 12778064Sume * in July 2000, on ipngwg mailing list. 12878064Sume */ 12962587Sitojun if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || 13078064Sume IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 13178064Sume IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { 13253541Sshin ip6stat.ip6s_cantforward++; 13353541Sshin /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 13453541Sshin if (ip6_log_time + ip6_log_interval < time_second) { 13553541Sshin ip6_log_time = time_second; 13653541Sshin log(LOG_DEBUG, 13753541Sshin "cannot forward " 13853541Sshin "from %s to %s nxt %d received on %s\n", 13962587Sitojun ip6_sprintf(&ip6->ip6_src), 14062587Sitojun ip6_sprintf(&ip6->ip6_dst), 14153541Sshin ip6->ip6_nxt, 14253541Sshin if_name(m->m_pkthdr.rcvif)); 14353541Sshin } 14453541Sshin m_freem(m); 14553541Sshin return; 14653541Sshin } 14753541Sshin 14853541Sshin if (ip6->ip6_hlim <= IPV6_HLIMDEC) { 14953541Sshin /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 15053541Sshin icmp6_error(m, ICMP6_TIME_EXCEEDED, 15153541Sshin ICMP6_TIME_EXCEED_TRANSIT, 0); 15253541Sshin return; 15353541Sshin } 15453541Sshin ip6->ip6_hlim -= IPV6_HLIMDEC; 15553541Sshin 15662587Sitojun /* 15762587Sitojun * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - 15862587Sitojun * size of IPv6 + ICMPv6 headers) bytes of the packet in case 15962587Sitojun * we need to generate an ICMP6 message to the src. 16062587Sitojun * Thanks to M_EXT, in most cases copy will not occur. 16162587Sitojun * 16262587Sitojun * It is important to save it before IPsec processing as IPsec 16362587Sitojun * processing may modify the mbuf. 16462587Sitojun */ 16562587Sitojun mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); 16662587Sitojun 16763256Sitojun#ifdef IPSEC 16853541Sshin /* get a security policy for this packet */ 16978064Sume sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, 17078064Sume &error); 17153541Sshin if (sp == NULL) { 17253541Sshin ipsec6stat.out_inval++; 17353541Sshin ip6stat.ip6s_cantforward++; 17462587Sitojun if (mcopy) { 17562587Sitojun#if 0 17662587Sitojun /* XXX: what icmp ? */ 17762587Sitojun#else 17862587Sitojun m_freem(mcopy); 17962587Sitojun#endif 18062587Sitojun } 18153541Sshin m_freem(m); 18253541Sshin return; 18353541Sshin } 18453541Sshin 18553541Sshin error = 0; 18653541Sshin 18753541Sshin /* check policy */ 18853541Sshin switch (sp->policy) { 18953541Sshin case IPSEC_POLICY_DISCARD: 19053541Sshin /* 19153541Sshin * This packet is just discarded. 19253541Sshin */ 19353541Sshin ipsec6stat.out_polvio++; 19453541Sshin ip6stat.ip6s_cantforward++; 19553541Sshin key_freesp(sp); 19662587Sitojun if (mcopy) { 19762587Sitojun#if 0 19862587Sitojun /* XXX: what icmp ? */ 19962587Sitojun#else 20062587Sitojun m_freem(mcopy); 20162587Sitojun#endif 20262587Sitojun } 20353541Sshin m_freem(m); 20453541Sshin return; 20553541Sshin 20653541Sshin case IPSEC_POLICY_BYPASS: 20753541Sshin case IPSEC_POLICY_NONE: 20853541Sshin /* no need to do IPsec. */ 20953541Sshin key_freesp(sp); 21053541Sshin goto skip_ipsec; 21162587Sitojun 21253541Sshin case IPSEC_POLICY_IPSEC: 21353541Sshin if (sp->req == NULL) { 21453541Sshin /* XXX should be panic ? */ 21553541Sshin printf("ip6_forward: No IPsec request specified.\n"); 21653541Sshin ip6stat.ip6s_cantforward++; 21753541Sshin key_freesp(sp); 21862587Sitojun if (mcopy) { 21962587Sitojun#if 0 22062587Sitojun /* XXX: what icmp ? */ 22162587Sitojun#else 22262587Sitojun m_freem(mcopy); 22362587Sitojun#endif 22462587Sitojun } 22553541Sshin m_freem(m); 22653541Sshin return; 22753541Sshin } 22853541Sshin /* do IPsec */ 22953541Sshin break; 23053541Sshin 23153541Sshin case IPSEC_POLICY_ENTRUST: 23253541Sshin default: 23353541Sshin /* should be panic ?? */ 23453541Sshin printf("ip6_forward: Invalid policy found. %d\n", sp->policy); 23553541Sshin key_freesp(sp); 23653541Sshin goto skip_ipsec; 23753541Sshin } 23853541Sshin 23953541Sshin { 24053541Sshin struct ipsec_output_state state; 24153541Sshin 24253541Sshin /* 24353541Sshin * All the extension headers will become inaccessible 24453541Sshin * (since they can be encrypted). 24553541Sshin * Don't panic, we need no more updates to extension headers 24653541Sshin * on inner IPv6 packet (since they are now encapsulated). 24753541Sshin * 24853541Sshin * IPv6 [ESP|AH] IPv6 [extension headers] payload 24953541Sshin */ 25053541Sshin bzero(&state, sizeof(state)); 25153541Sshin state.m = m; 25253541Sshin state.ro = NULL; /* update at ipsec6_output_tunnel() */ 25353541Sshin state.dst = NULL; /* update at ipsec6_output_tunnel() */ 25453541Sshin 25553541Sshin error = ipsec6_output_tunnel(&state, sp, 0); 25653541Sshin 25753541Sshin m = state.m; 25853541Sshin key_freesp(sp); 25953541Sshin 26053541Sshin if (error) { 26153541Sshin /* mbuf is already reclaimed in ipsec6_output_tunnel. */ 26253541Sshin switch (error) { 26353541Sshin case EHOSTUNREACH: 26453541Sshin case ENETUNREACH: 26553541Sshin case EMSGSIZE: 26653541Sshin case ENOBUFS: 26753541Sshin case ENOMEM: 26853541Sshin break; 26953541Sshin default: 27053541Sshin printf("ip6_output (ipsec): error code %d\n", error); 27153541Sshin /*fall through*/ 27253541Sshin case ENOENT: 27353541Sshin /* don't show these error codes to the user */ 27453541Sshin break; 27553541Sshin } 27653541Sshin ip6stat.ip6s_cantforward++; 27762587Sitojun if (mcopy) { 27862587Sitojun#if 0 27962587Sitojun /* XXX: what icmp ? */ 28062587Sitojun#else 28162587Sitojun m_freem(mcopy); 28262587Sitojun#endif 28362587Sitojun } 28453541Sshin m_freem(m); 28553541Sshin return; 28653541Sshin } 28753541Sshin } 28853541Sshin skip_ipsec: 28963256Sitojun#endif /* IPSEC */ 29053541Sshin 29178064Sume dst = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; 29253541Sshin if (!srcrt) { 29353541Sshin /* 29453541Sshin * ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst 29553541Sshin */ 29653541Sshin if (ip6_forward_rt.ro_rt == 0 || 29753541Sshin (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0) { 29853541Sshin if (ip6_forward_rt.ro_rt) { 29953541Sshin RTFREE(ip6_forward_rt.ro_rt); 30053541Sshin ip6_forward_rt.ro_rt = 0; 30153541Sshin } 30253541Sshin /* this probably fails but give it a try again */ 30353541Sshin rtalloc_ign((struct route *)&ip6_forward_rt, 30453541Sshin RTF_PRCLONING); 30553541Sshin } 30662587Sitojun 30753541Sshin if (ip6_forward_rt.ro_rt == 0) { 30853541Sshin ip6stat.ip6s_noroute++; 30978064Sume in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 31062587Sitojun if (mcopy) { 31162587Sitojun icmp6_error(mcopy, ICMP6_DST_UNREACH, 31262587Sitojun ICMP6_DST_UNREACH_NOROUTE, 0); 31362587Sitojun } 31462587Sitojun m_freem(m); 31553541Sshin return; 31653541Sshin } 31753541Sshin } else if ((rt = ip6_forward_rt.ro_rt) == 0 || 31853541Sshin !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) { 31953541Sshin if (ip6_forward_rt.ro_rt) { 32053541Sshin RTFREE(ip6_forward_rt.ro_rt); 32153541Sshin ip6_forward_rt.ro_rt = 0; 32253541Sshin } 32353541Sshin bzero(dst, sizeof(*dst)); 32453541Sshin dst->sin6_len = sizeof(struct sockaddr_in6); 32553541Sshin dst->sin6_family = AF_INET6; 32653541Sshin dst->sin6_addr = ip6->ip6_dst; 32753541Sshin 32853541Sshin rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); 32953541Sshin if (ip6_forward_rt.ro_rt == 0) { 33053541Sshin ip6stat.ip6s_noroute++; 33178064Sume in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 33262587Sitojun if (mcopy) { 33362587Sitojun icmp6_error(mcopy, ICMP6_DST_UNREACH, 33462587Sitojun ICMP6_DST_UNREACH_NOROUTE, 0); 33562587Sitojun } 33662587Sitojun m_freem(m); 33753541Sshin return; 33853541Sshin } 33953541Sshin } 34053541Sshin rt = ip6_forward_rt.ro_rt; 34162587Sitojun 34262587Sitojun /* 34362587Sitojun * Scope check: if a packet can't be delivered to its destination 34462587Sitojun * for the reason that the destination is beyond the scope of the 34562587Sitojun * source address, discard the packet and return an icmp6 destination 34662587Sitojun * unreachable error with Code 2 (beyond scope of source address). 34762587Sitojun * [draft-ietf-ipngwg-icmp-v3-00.txt, Section 3.1] 34862587Sitojun */ 34962587Sitojun if (in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_src) != 35062587Sitojun in6_addr2scopeid(rt->rt_ifp, &ip6->ip6_src)) { 35162587Sitojun ip6stat.ip6s_cantforward++; 35262587Sitojun ip6stat.ip6s_badscope++; 35362587Sitojun in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); 35462587Sitojun 35562587Sitojun if (ip6_log_time + ip6_log_interval < time_second) { 35662587Sitojun ip6_log_time = time_second; 35762587Sitojun log(LOG_DEBUG, 35862587Sitojun "cannot forward " 35962587Sitojun "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 36062587Sitojun ip6_sprintf(&ip6->ip6_src), 36162587Sitojun ip6_sprintf(&ip6->ip6_dst), 36262587Sitojun ip6->ip6_nxt, 36362587Sitojun if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); 36462587Sitojun } 36562587Sitojun if (mcopy) 36662587Sitojun icmp6_error(mcopy, ICMP6_DST_UNREACH, 36762587Sitojun ICMP6_DST_UNREACH_BEYONDSCOPE, 0); 36862587Sitojun m_freem(m); 36962587Sitojun return; 37062587Sitojun } 37162587Sitojun 37262587Sitojun if (m->m_pkthdr.len > rt->rt_ifp->if_mtu) { 37353541Sshin in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); 37462587Sitojun if (mcopy) { 37562587Sitojun u_long mtu; 37663256Sitojun#ifdef IPSEC 37762587Sitojun struct secpolicy *sp; 37862587Sitojun int ipsecerror; 37962587Sitojun size_t ipsechdrsiz; 38062587Sitojun#endif 38162587Sitojun 38262587Sitojun mtu = rt->rt_ifp->if_mtu; 38363256Sitojun#ifdef IPSEC 38462587Sitojun /* 38562587Sitojun * When we do IPsec tunnel ingress, we need to play 38662587Sitojun * with if_mtu value (decrement IPsec header size 38762587Sitojun * from mtu value). The code is much simpler than v4 38862587Sitojun * case, as we have the outgoing interface for 38962587Sitojun * encapsulated packet as "rt->rt_ifp". 39062587Sitojun */ 39162587Sitojun sp = ipsec6_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, 39262587Sitojun IP_FORWARDING, &ipsecerror); 39362587Sitojun if (sp) { 39462587Sitojun ipsechdrsiz = ipsec6_hdrsiz(mcopy, 39562587Sitojun IPSEC_DIR_OUTBOUND, NULL); 39662587Sitojun if (ipsechdrsiz < mtu) 39762587Sitojun mtu -= ipsechdrsiz; 39862587Sitojun } 39962587Sitojun 40062587Sitojun /* 40162587Sitojun * if mtu becomes less than minimum MTU, 40262587Sitojun * tell minimum MTU (and I'll need to fragment it). 40362587Sitojun */ 40462587Sitojun if (mtu < IPV6_MMTU) 40562587Sitojun mtu = IPV6_MMTU; 40662587Sitojun#endif 40762587Sitojun icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); 40862587Sitojun } 40962587Sitojun m_freem(m); 41053541Sshin return; 41153541Sshin } 41253541Sshin 41353541Sshin if (rt->rt_flags & RTF_GATEWAY) 41453541Sshin dst = (struct sockaddr_in6 *)rt->rt_gateway; 41553541Sshin 41653541Sshin /* 41753541Sshin * If we are to forward the packet using the same interface 41853541Sshin * as one we got the packet from, perhaps we should send a redirect 41953541Sshin * to sender to shortcut a hop. 42053541Sshin * Only send redirect if source is sending directly to us, 42153541Sshin * and if packet was not source routed (or has any options). 42253541Sshin * Also, don't send redirect if forwarding using a route 42353541Sshin * modified by a redirect. 42453541Sshin */ 42553541Sshin if (rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && 42678064Sume (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { 42778064Sume if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { 42878064Sume /* 42978064Sume * If the incoming interface is equal to the outgoing 43078064Sume * one, and the link attached to the interface is 43178064Sume * point-to-point, then it will be highly probable 43278064Sume * that a routing loop occurs. Thus, we immediately 43378064Sume * drop the packet and send an ICMPv6 error message. 43478064Sume * 43578064Sume * type/code is based on suggestion by Rich Draves. 43678064Sume * not sure if it is the best pick. 43778064Sume */ 43878064Sume icmp6_error(mcopy, ICMP6_DST_UNREACH, 43978064Sume ICMP6_DST_UNREACH_ADDR, 0); 44078064Sume m_freem(m); 44178064Sume return; 44278064Sume } 44353541Sshin type = ND_REDIRECT; 44478064Sume } 44553541Sshin 44653541Sshin /* 44753541Sshin * Check with the firewall... 44853541Sshin */ 44966303Sume if (ip6_fw_enable && ip6_fw_chk_ptr) { 45053541Sshin u_short port = 0; 45153541Sshin /* If ipfw says divert, we have to just drop packet */ 45253541Sshin if ((*ip6_fw_chk_ptr)(&ip6, rt->rt_ifp, &port, &m)) { 45353541Sshin m_freem(m); 45453541Sshin goto freecopy; 45553541Sshin } 45653541Sshin if (!m) 45753541Sshin goto freecopy; 45853541Sshin } 45953541Sshin 46062587Sitojun /* 46162587Sitojun * Fake scoped addresses. Note that even link-local source or 46262587Sitojun * destinaion can appear, if the originating node just sends the 46362587Sitojun * packet to us (without address resolution for the destination). 46462587Sitojun * Since both icmp6_error and icmp6_redirect_output fill the embedded 46578064Sume * link identifiers, we can do this stuff after making a copy for 46678064Sume * returning an error. 46762587Sitojun */ 46862587Sitojun if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { 46962587Sitojun /* 47062587Sitojun * See corresponding comments in ip6_output. 47162587Sitojun * XXX: but is it possible that ip6_forward() sends a packet 47262587Sitojun * to a loopback interface? I don't think so, and thus 47362587Sitojun * I bark here. (jinmei@kame.net) 47462587Sitojun * XXX: it is common to route invalid packets to loopback. 47562587Sitojun * also, the codepath will be visited on use of ::1 in 47662587Sitojun * rthdr. (itojun) 47762587Sitojun */ 47862587Sitojun#if 1 47962587Sitojun if (0) 48062587Sitojun#else 48162587Sitojun if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) 48262587Sitojun#endif 48362587Sitojun { 48462587Sitojun printf("ip6_forward: outgoing interface is loopback. " 48562587Sitojun "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 48662587Sitojun ip6_sprintf(&ip6->ip6_src), 48762587Sitojun ip6_sprintf(&ip6->ip6_dst), 48862587Sitojun ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), 48962587Sitojun if_name(rt->rt_ifp)); 49062587Sitojun } 49162587Sitojun 49278064Sume /* we can just use rcvif in forwarding. */ 49378064Sume origifp = m->m_pkthdr.rcvif; 49462587Sitojun } 49562587Sitojun else 49662587Sitojun origifp = rt->rt_ifp; 49778064Sume#ifndef SCOPEDROUTING 49878064Sume /* 49978064Sume * clear embedded scope identifiers if necessary. 50078064Sume * in6_clearscope will touch the addresses only when necessary. 50178064Sume */ 50278064Sume in6_clearscope(&ip6->ip6_src); 50378064Sume in6_clearscope(&ip6->ip6_dst); 50462587Sitojun#endif 50562587Sitojun 50662587Sitojun error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); 50753541Sshin if (error) { 50853541Sshin in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); 50953541Sshin ip6stat.ip6s_cantforward++; 51053541Sshin } else { 51153541Sshin ip6stat.ip6s_forward++; 51253541Sshin in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); 51353541Sshin if (type) 51453541Sshin ip6stat.ip6s_redirectsent++; 51553541Sshin else { 51653541Sshin if (mcopy) 51753541Sshin goto freecopy; 51853541Sshin } 51953541Sshin } 52053541Sshin if (mcopy == NULL) 52153541Sshin return; 52253541Sshin 52353541Sshin switch (error) { 52453541Sshin case 0: 52562587Sitojun#if 1 52653541Sshin if (type == ND_REDIRECT) { 52753541Sshin icmp6_redirect_output(mcopy, rt); 52853541Sshin return; 52953541Sshin } 53062587Sitojun#endif 53153541Sshin goto freecopy; 53253541Sshin 53353541Sshin case EMSGSIZE: 53453541Sshin /* xxx MTU is constant in PPP? */ 53553541Sshin goto freecopy; 53653541Sshin 53753541Sshin case ENOBUFS: 53853541Sshin /* Tell source to slow down like source quench in IP? */ 53953541Sshin goto freecopy; 54053541Sshin 54153541Sshin case ENETUNREACH: /* shouldn't happen, checked above */ 54253541Sshin case EHOSTUNREACH: 54353541Sshin case ENETDOWN: 54453541Sshin case EHOSTDOWN: 54553541Sshin default: 54653541Sshin type = ICMP6_DST_UNREACH; 54753541Sshin code = ICMP6_DST_UNREACH_ADDR; 54853541Sshin break; 54953541Sshin } 55053541Sshin icmp6_error(mcopy, type, code, 0); 55153541Sshin return; 55253541Sshin 55353541Sshin freecopy: 55453541Sshin m_freem(mcopy); 55553541Sshin return; 55653541Sshin} 557