1139826Simp/*- 253541Sshin * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 353541Sshin * All rights reserved. 453541Sshin * 553541Sshin * Redistribution and use in source and binary forms, with or without 653541Sshin * modification, are permitted provided that the following conditions 753541Sshin * are met: 853541Sshin * 1. Redistributions of source code must retain the above copyright 953541Sshin * notice, this list of conditions and the following disclaimer. 1053541Sshin * 2. Redistributions in binary form must reproduce the above copyright 1153541Sshin * notice, this list of conditions and the following disclaimer in the 1253541Sshin * documentation and/or other materials provided with the distribution. 1353541Sshin * 3. Neither the name of the project nor the names of its contributors 1453541Sshin * may be used to endorse or promote products derived from this software 1553541Sshin * without specific prior written permission. 1653541Sshin * 1753541Sshin * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 1853541Sshin * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1953541Sshin * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2053541Sshin * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 2153541Sshin * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2253541Sshin * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2353541Sshin * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2453541Sshin * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2553541Sshin * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2653541Sshin * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2753541Sshin * SUCH DAMAGE. 28174510Sobrien * 29174510Sobrien * $KAME: ip6_forward.c,v 1.69 2001/05/17 03:48:30 itojun Exp $ 3053541Sshin */ 3153541Sshin 32174510Sobrien#include <sys/cdefs.h> 33174510Sobrien__FBSDID("$FreeBSD: releng/10.3/sys/netinet6/ip6_forward.c 284576 2015-06-18 20:57:21Z kp $"); 34174510Sobrien 3562587Sitojun#include "opt_inet.h" 3662587Sitojun#include "opt_inet6.h" 37225044Sbz#include "opt_ipfw.h" 3855009Sshin#include "opt_ipsec.h" 39148921Ssuz#include "opt_ipstealth.h" 4053541Sshin 4153541Sshin#include <sys/param.h> 4253541Sshin#include <sys/systm.h> 4378064Sume#include <sys/malloc.h> 4453541Sshin#include <sys/mbuf.h> 4553541Sshin#include <sys/domain.h> 4653541Sshin#include <sys/protosw.h> 4753541Sshin#include <sys/socket.h> 4853541Sshin#include <sys/errno.h> 4953541Sshin#include <sys/time.h> 5078064Sume#include <sys/kernel.h> 5153541Sshin#include <sys/syslog.h> 5253541Sshin 5353541Sshin#include <net/if.h> 54225044Sbz#include <net/netisr.h> 5553541Sshin#include <net/route.h> 5684994Sdarrenr#include <net/pfil.h> 5753541Sshin 5853541Sshin#include <netinet/in.h> 5953541Sshin#include <netinet/in_var.h> 6078064Sume#include <netinet/in_systm.h> 6178064Sume#include <netinet/ip.h> 6262587Sitojun#include <netinet/ip_var.h> 6378064Sume#include <netinet6/in6_var.h> 6462587Sitojun#include <netinet/ip6.h> 6553541Sshin#include <netinet6/ip6_var.h> 66148385Sume#include <netinet6/scope6_var.h> 6762587Sitojun#include <netinet/icmp6.h> 6853541Sshin#include <netinet6/nd6.h> 6953541Sshin 7078064Sume#include <netinet/in_pcb.h> 7178064Sume 72171167Sgnn#ifdef IPSEC 73105199Ssam#include <netipsec/ipsec.h> 74105199Ssam#include <netipsec/ipsec6.h> 75105199Ssam#include <netipsec/key.h> 76171167Sgnn#endif /* IPSEC */ 77105199Ssam 7884994Sdarrenr#include <netinet6/ip6protosw.h> 7984994Sdarrenr 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 */ 9253541Sshinvoid 93171259Sdelphijip6_forward(struct mbuf *m, int srcrt) 9453541Sshin{ 9553541Sshin struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 96122062Sume struct sockaddr_in6 *dst = NULL; 97122062Sume struct rtentry *rt = NULL; 98187989Sbz struct route_in6 rin6; 9953541Sshin int error, type = 0, code = 0; 10062587Sitojun struct mbuf *mcopy = NULL; 10162587Sitojun struct ifnet *origifp; /* maybe unnecessary */ 102148385Sume u_int32_t inzone, outzone; 103225044Sbz struct in6_addr src_in6, dst_in6, odst; 104171167Sgnn#ifdef IPSEC 10553541Sshin struct secpolicy *sp = NULL; 106122062Sume int ipsecrt = 0; 10753541Sshin#endif 108225044Sbz#ifdef SCTP 109225044Sbz int sw_csum; 110225044Sbz#endif 111225044Sbz struct m_tag *fwd_tag; 112165118Sbz char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 11353541Sshin 114171167Sgnn#ifdef IPSEC 11553541Sshin /* 11653541Sshin * Check AH/ESP integrity. 11753541Sshin */ 11853541Sshin /* 11953541Sshin * Don't increment ip6s_cantforward because this is the check 12053541Sshin * before forwarding packet actually. 12153541Sshin */ 12253541Sshin if (ipsec6_in_reject(m, NULL)) { 123253571Sae IPSEC6STAT_INC(ips_in_polvio); 12453541Sshin m_freem(m); 12553541Sshin return; 12653541Sshin } 127171167Sgnn#endif /* IPSEC */ 12853541Sshin 12978064Sume /* 13078064Sume * Do not forward packets to multicast destination (should be handled 13178064Sume * by ip6_mforward(). 13278064Sume * Do not forward packets with unspecified source. It was discussed 133120913Sume * in July 2000, on the ipngwg mailing list. 13478064Sume */ 13562587Sitojun if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || 13678064Sume IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 13778064Sume IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { 138249294Sae IP6STAT_INC(ip6s_cantforward); 13953541Sshin /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 140253970Shrs if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { 141253970Shrs V_ip6_log_time = time_uptime; 14253541Sshin log(LOG_DEBUG, 14353541Sshin "cannot forward " 14453541Sshin "from %s to %s nxt %d received on %s\n", 145165118Sbz ip6_sprintf(ip6bufs, &ip6->ip6_src), 146165118Sbz ip6_sprintf(ip6bufd, &ip6->ip6_dst), 14753541Sshin ip6->ip6_nxt, 14853541Sshin if_name(m->m_pkthdr.rcvif)); 14953541Sshin } 15053541Sshin m_freem(m); 15153541Sshin return; 15253541Sshin } 15353541Sshin 154148921Ssuz#ifdef IPSTEALTH 155181803Sbz if (!V_ip6stealth) { 156148921Ssuz#endif 15753541Sshin if (ip6->ip6_hlim <= IPV6_HLIMDEC) { 15853541Sshin /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ 15953541Sshin icmp6_error(m, ICMP6_TIME_EXCEEDED, 16053541Sshin ICMP6_TIME_EXCEED_TRANSIT, 0); 16153541Sshin return; 16253541Sshin } 16353541Sshin ip6->ip6_hlim -= IPV6_HLIMDEC; 16453541Sshin 165148921Ssuz#ifdef IPSTEALTH 166148921Ssuz } 167148921Ssuz#endif 168148921Ssuz 16962587Sitojun /* 17062587Sitojun * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - 17162587Sitojun * size of IPv6 + ICMPv6 headers) bytes of the packet in case 17262587Sitojun * we need to generate an ICMP6 message to the src. 17362587Sitojun * Thanks to M_EXT, in most cases copy will not occur. 17462587Sitojun * 17562587Sitojun * It is important to save it before IPsec processing as IPsec 17662587Sitojun * processing may modify the mbuf. 17762587Sitojun */ 17862587Sitojun mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); 17962587Sitojun 180171167Sgnn#ifdef IPSEC 18153541Sshin /* get a security policy for this packet */ 182171133Sgnn sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 183120913Sume IP_FORWARDING, &error); 18453541Sshin if (sp == NULL) { 185253571Sae IPSEC6STAT_INC(ips_out_inval); 186249294Sae IP6STAT_INC(ip6s_cantforward); 18762587Sitojun if (mcopy) { 18862587Sitojun#if 0 18962587Sitojun /* XXX: what icmp ? */ 19062587Sitojun#else 19162587Sitojun m_freem(mcopy); 19262587Sitojun#endif 19362587Sitojun } 19453541Sshin m_freem(m); 19553541Sshin return; 19653541Sshin } 19753541Sshin 19853541Sshin error = 0; 19953541Sshin 20053541Sshin /* check policy */ 20153541Sshin switch (sp->policy) { 20253541Sshin case IPSEC_POLICY_DISCARD: 20353541Sshin /* 20453541Sshin * This packet is just discarded. 20553541Sshin */ 206253571Sae IPSEC6STAT_INC(ips_out_polvio); 207249294Sae IP6STAT_INC(ip6s_cantforward); 208171133Sgnn KEY_FREESP(&sp); 20962587Sitojun if (mcopy) { 21062587Sitojun#if 0 21162587Sitojun /* XXX: what icmp ? */ 21262587Sitojun#else 21362587Sitojun m_freem(mcopy); 21462587Sitojun#endif 21562587Sitojun } 21653541Sshin m_freem(m); 21753541Sshin return; 21853541Sshin 21953541Sshin case IPSEC_POLICY_BYPASS: 22053541Sshin case IPSEC_POLICY_NONE: 22153541Sshin /* no need to do IPsec. */ 222171133Sgnn KEY_FREESP(&sp); 22353541Sshin goto skip_ipsec; 22462587Sitojun 22553541Sshin case IPSEC_POLICY_IPSEC: 22653541Sshin if (sp->req == NULL) { 22753541Sshin /* XXX should be panic ? */ 22853541Sshin printf("ip6_forward: No IPsec request specified.\n"); 229249294Sae IP6STAT_INC(ip6s_cantforward); 230171133Sgnn KEY_FREESP(&sp); 23162587Sitojun if (mcopy) { 23262587Sitojun#if 0 23362587Sitojun /* XXX: what icmp ? */ 23462587Sitojun#else 23562587Sitojun m_freem(mcopy); 23662587Sitojun#endif 23762587Sitojun } 23853541Sshin m_freem(m); 23953541Sshin return; 24053541Sshin } 24153541Sshin /* do IPsec */ 24253541Sshin break; 24353541Sshin 24453541Sshin case IPSEC_POLICY_ENTRUST: 24553541Sshin default: 24653541Sshin /* should be panic ?? */ 24753541Sshin printf("ip6_forward: Invalid policy found. %d\n", sp->policy); 248171133Sgnn KEY_FREESP(&sp); 24953541Sshin goto skip_ipsec; 25053541Sshin } 25153541Sshin 25253541Sshin { 253122062Sume struct ipsecrequest *isr = NULL; 25453541Sshin 25553541Sshin /* 256122062Sume * when the kernel forwards a packet, it is not proper to apply 257122062Sume * IPsec transport mode to the packet is not proper. this check 258122062Sume * avoid from this. 259122062Sume * at present, if there is even a transport mode SA request in the 260122062Sume * security policy, the kernel does not apply IPsec to the packet. 261122062Sume * this check is not enough because the following case is valid. 262122062Sume * ipsec esp/tunnel/xxx-xxx/require esp/transport//require; 263122062Sume */ 264122062Sume for (isr = sp->req; isr; isr = isr->next) { 265126006Sume if (isr->saidx.mode == IPSEC_MODE_ANY) 266126006Sume goto doipsectunnel; 267126006Sume if (isr->saidx.mode == IPSEC_MODE_TUNNEL) 268126006Sume goto doipsectunnel; 269122062Sume } 270122062Sume 271122062Sume /* 272126006Sume * if there's no need for tunnel mode IPsec, skip. 273126006Sume */ 274126006Sume if (!isr) 275126006Sume goto skip_ipsec; 276126006Sume 277126006Sume doipsectunnel: 278126006Sume /* 27953541Sshin * All the extension headers will become inaccessible 28053541Sshin * (since they can be encrypted). 28153541Sshin * Don't panic, we need no more updates to extension headers 28253541Sshin * on inner IPv6 packet (since they are now encapsulated). 28353541Sshin * 28453541Sshin * IPv6 [ESP|AH] IPv6 [extension headers] payload 28553541Sshin */ 28653541Sshin 287274132Sae /* 288274132Sae * If we need to encapsulate the packet, do it here 289274132Sae * ipsec6_proces_packet will send the packet using ip6_output 290274132Sae */ 291274132Sae error = ipsec6_process_packet(m, sp->req); 29253541Sshin 293171133Sgnn KEY_FREESP(&sp); 29453541Sshin 295274132Sae if (error == EJUSTRETURN) { 296274132Sae /* 297274132Sae * We had a SP with a level of 'use' and no SA. We 298274132Sae * will just continue to process the packet without 299274132Sae * IPsec processing. 300274132Sae */ 301274132Sae error = 0; 302274132Sae goto skip_ipsec; 303274132Sae } 304274132Sae 30553541Sshin if (error) { 306274132Sae /* mbuf is already reclaimed in ipsec6_process_packet. */ 30753541Sshin switch (error) { 30853541Sshin case EHOSTUNREACH: 30953541Sshin case ENETUNREACH: 31053541Sshin case EMSGSIZE: 31153541Sshin case ENOBUFS: 31253541Sshin case ENOMEM: 31353541Sshin break; 31453541Sshin default: 31553541Sshin printf("ip6_output (ipsec): error code %d\n", error); 316120913Sume /* FALLTHROUGH */ 31753541Sshin case ENOENT: 31853541Sshin /* don't show these error codes to the user */ 31953541Sshin break; 32053541Sshin } 321249294Sae IP6STAT_INC(ip6s_cantforward); 32262587Sitojun if (mcopy) { 32362587Sitojun#if 0 32462587Sitojun /* XXX: what icmp ? */ 32562587Sitojun#else 32662587Sitojun m_freem(mcopy); 32762587Sitojun#endif 32862587Sitojun } 32953541Sshin return; 330171133Sgnn } else { 331171260Sdelphij /* 332171260Sdelphij * In the FAST IPSec case we have already 333171133Sgnn * re-injected the packet and it has been freed 334171260Sdelphij * by the ipsec_done() function. So, just clean 335171133Sgnn * up after ourselves. 336171133Sgnn */ 337171133Sgnn m = NULL; 338171133Sgnn goto freecopy; 33953541Sshin } 34053541Sshin } 341187949Sbzskip_ipsec: 342122062Sume#endif 343225044Sbzagain: 344187989Sbz bzero(&rin6, sizeof(struct route_in6)); 345187989Sbz dst = (struct sockaddr_in6 *)&rin6.ro_dst; 346187989Sbz dst->sin6_len = sizeof(struct sockaddr_in6); 347187989Sbz dst->sin6_family = AF_INET6; 348187989Sbz dst->sin6_addr = ip6->ip6_dst; 349225044Sbzagain2: 350231852Sbz rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m)); 351187989Sbz if (rin6.ro_rt != NULL) 352187989Sbz RT_UNLOCK(rin6.ro_rt); 353187989Sbz else { 354249294Sae IP6STAT_INC(ip6s_noroute); 355187989Sbz in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); 356187989Sbz if (mcopy) { 357187989Sbz icmp6_error(mcopy, ICMP6_DST_UNREACH, 358187989Sbz ICMP6_DST_UNREACH_NOROUTE, 0); 35953541Sshin } 360187989Sbz goto bad; 36153541Sshin } 362187989Sbz rt = rin6.ro_rt; 36362587Sitojun 36462587Sitojun /* 365148385Sume * Source scope check: if a packet can't be delivered to its 366148385Sume * destination for the reason that the destination is beyond the scope 367148385Sume * of the source address, discard the packet and return an icmp6 368148385Sume * destination unreachable error with Code 2 (beyond scope of source 369148385Sume * address). We use a local copy of ip6_src, since in6_setscope() 370148385Sume * will possibly modify its first argument. 371148385Sume * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] 37262587Sitojun */ 373148385Sume src_in6 = ip6->ip6_src; 374148385Sume if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { 375122062Sume /* XXX: this should not happen */ 376249294Sae IP6STAT_INC(ip6s_cantforward); 377249294Sae IP6STAT_INC(ip6s_badscope); 378187989Sbz goto bad; 379122062Sume } 380148385Sume if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { 381249294Sae IP6STAT_INC(ip6s_cantforward); 382249294Sae IP6STAT_INC(ip6s_badscope); 383187989Sbz goto bad; 384148385Sume } 385148385Sume if (inzone != outzone 386171167Sgnn#ifdef IPSEC 387122062Sume && !ipsecrt 388122062Sume#endif 389122062Sume ) { 390249294Sae IP6STAT_INC(ip6s_cantforward); 391249294Sae IP6STAT_INC(ip6s_badscope); 39262587Sitojun in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); 39362587Sitojun 394253970Shrs if (V_ip6_log_time + V_ip6_log_interval < time_uptime) { 395253970Shrs V_ip6_log_time = time_uptime; 39662587Sitojun log(LOG_DEBUG, 39762587Sitojun "cannot forward " 39862587Sitojun "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 399165118Sbz ip6_sprintf(ip6bufs, &ip6->ip6_src), 400165118Sbz ip6_sprintf(ip6bufd, &ip6->ip6_dst), 40162587Sitojun ip6->ip6_nxt, 40262587Sitojun if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); 40362587Sitojun } 40462587Sitojun if (mcopy) 40562587Sitojun icmp6_error(mcopy, ICMP6_DST_UNREACH, 40662587Sitojun ICMP6_DST_UNREACH_BEYONDSCOPE, 0); 407187989Sbz goto bad; 40862587Sitojun } 40962587Sitojun 410148385Sume /* 411148385Sume * Destination scope check: if a packet is going to break the scope 412148385Sume * zone of packet's destination address, discard it. This case should 413148385Sume * usually be prevented by appropriately-configured routing table, but 414148385Sume * we need an explicit check because we may mistakenly forward the 415148385Sume * packet to a different zone by (e.g.) a default route. 416148385Sume */ 417148385Sume dst_in6 = ip6->ip6_dst; 418148385Sume if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || 419148385Sume in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || 420148385Sume inzone != outzone) { 421249294Sae IP6STAT_INC(ip6s_cantforward); 422249294Sae IP6STAT_INC(ip6s_badscope); 423187989Sbz goto bad; 424148385Sume } 425148385Sume 42653541Sshin if (rt->rt_flags & RTF_GATEWAY) 42753541Sshin dst = (struct sockaddr_in6 *)rt->rt_gateway; 42853541Sshin 42953541Sshin /* 43053541Sshin * If we are to forward the packet using the same interface 43153541Sshin * as one we got the packet from, perhaps we should send a redirect 43253541Sshin * to sender to shortcut a hop. 43353541Sshin * Only send redirect if source is sending directly to us, 43453541Sshin * and if packet was not source routed (or has any options). 43553541Sshin * Also, don't send redirect if forwarding using a route 43653541Sshin * modified by a redirect. 43753541Sshin */ 438181803Sbz if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && 439171167Sgnn#ifdef IPSEC 440122062Sume !ipsecrt && 441171167Sgnn#endif /* IPSEC */ 44278064Sume (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { 44378064Sume if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { 44478064Sume /* 44578064Sume * If the incoming interface is equal to the outgoing 44678064Sume * one, and the link attached to the interface is 44778064Sume * point-to-point, then it will be highly probable 44878064Sume * that a routing loop occurs. Thus, we immediately 44978064Sume * drop the packet and send an ICMPv6 error message. 45078064Sume * 45178064Sume * type/code is based on suggestion by Rich Draves. 45278064Sume * not sure if it is the best pick. 45378064Sume */ 45478064Sume icmp6_error(mcopy, ICMP6_DST_UNREACH, 45578064Sume ICMP6_DST_UNREACH_ADDR, 0); 456187989Sbz goto bad; 45778064Sume } 45853541Sshin type = ND_REDIRECT; 45978064Sume } 46053541Sshin 46153541Sshin /* 46262587Sitojun * Fake scoped addresses. Note that even link-local source or 46362587Sitojun * destinaion can appear, if the originating node just sends the 46462587Sitojun * packet to us (without address resolution for the destination). 46562587Sitojun * Since both icmp6_error and icmp6_redirect_output fill the embedded 46678064Sume * link identifiers, we can do this stuff after making a copy for 46778064Sume * returning an error. 46862587Sitojun */ 46962587Sitojun if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { 47062587Sitojun /* 47162587Sitojun * See corresponding comments in ip6_output. 47262587Sitojun * XXX: but is it possible that ip6_forward() sends a packet 47362587Sitojun * to a loopback interface? I don't think so, and thus 47462587Sitojun * I bark here. (jinmei@kame.net) 47562587Sitojun * XXX: it is common to route invalid packets to loopback. 47662587Sitojun * also, the codepath will be visited on use of ::1 in 47762587Sitojun * rthdr. (itojun) 47862587Sitojun */ 47962587Sitojun#if 1 48062587Sitojun if (0) 48162587Sitojun#else 48262587Sitojun if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) 48362587Sitojun#endif 48462587Sitojun { 48562587Sitojun printf("ip6_forward: outgoing interface is loopback. " 486120913Sume "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", 487165118Sbz ip6_sprintf(ip6bufs, &ip6->ip6_src), 488165118Sbz ip6_sprintf(ip6bufd, &ip6->ip6_dst), 489120913Sume ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), 490120913Sume if_name(rt->rt_ifp)); 49162587Sitojun } 49262587Sitojun 49378064Sume /* we can just use rcvif in forwarding. */ 49478064Sume origifp = m->m_pkthdr.rcvif; 49562587Sitojun } 49662587Sitojun else 49762587Sitojun origifp = rt->rt_ifp; 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 505134383Sandre /* Jump over all PFIL processing if hooks are not active. */ 506197952Sjulian if (!PFIL_HOOKED(&V_inet6_pfil_hook)) 507134383Sandre goto pass; 508134383Sandre 509225044Sbz odst = ip6->ip6_dst; 510134383Sandre /* Run through list of hooks for output packets. */ 511197952Sjulian error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); 512264224Sae if (error != 0 || m == NULL) 513264224Sae goto freecopy; /* consumed by filter */ 514120386Ssam ip6 = mtod(m, struct ip6_hdr *); 51584994Sdarrenr 516225044Sbz /* See if destination IP address was changed by packet filter. */ 517225044Sbz if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) { 518225044Sbz m->m_flags |= M_SKIP_FIREWALL; 519225044Sbz /* If destination is now ourself drop to ip6_input(). */ 520284575Skp if (in6_localip(&ip6->ip6_dst)) 521225044Sbz m->m_flags |= M_FASTFWD_OURS; 522284575Skp else 523225044Sbz goto again; /* Redo the routing table lookup. */ 524225044Sbz } 525225044Sbz 526225044Sbz /* See if local, if yes, send it to netisr. */ 527225044Sbz if (m->m_flags & M_FASTFWD_OURS) { 528225044Sbz if (m->m_pkthdr.rcvif == NULL) 529225044Sbz m->m_pkthdr.rcvif = V_loif; 530236170Sbz if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) { 531225044Sbz m->m_pkthdr.csum_flags |= 532236170Sbz CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR; 533225044Sbz m->m_pkthdr.csum_data = 0xffff; 534225044Sbz } 535225044Sbz#ifdef SCTP 536236332Stuexen if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) 537236332Stuexen m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID; 538236332Stuexen#endif 539225044Sbz error = netisr_queue(NETISR_IPV6, m); 540225044Sbz goto out; 541225044Sbz } 542225044Sbz /* Or forward to some other address? */ 543242463Sae if ((m->m_flags & M_IP6_NEXTHOP) && 544242463Sae (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) { 545225044Sbz dst = (struct sockaddr_in6 *)&rin6.ro_dst; 546225044Sbz bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6)); 547225044Sbz m->m_flags |= M_SKIP_FIREWALL; 548242463Sae m->m_flags &= ~M_IP6_NEXTHOP; 549225044Sbz m_tag_delete(m, fwd_tag); 550225044Sbz goto again2; 551225044Sbz } 552225044Sbz 553134383Sandrepass: 554284576Skp /* See if the size was changed by the packet filter. */ 555284576Skp if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { 556284576Skp in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); 557284576Skp if (mcopy) { 558284576Skp u_long mtu; 559284576Skp#ifdef IPSEC 560284576Skp struct secpolicy *sp; 561284576Skp int ipsecerror; 562284576Skp size_t ipsechdrsiz; 563284576Skp#endif /* IPSEC */ 564284576Skp 565284576Skp mtu = IN6_LINKMTU(rt->rt_ifp); 566284576Skp#ifdef IPSEC 567284576Skp /* 568284576Skp * When we do IPsec tunnel ingress, we need to play 569284576Skp * with the link value (decrement IPsec header size 570284576Skp * from mtu value). The code is much simpler than v4 571284576Skp * case, as we have the outgoing interface for 572284576Skp * encapsulated packet as "rt->rt_ifp". 573284576Skp */ 574284576Skp sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, 575284576Skp IP_FORWARDING, &ipsecerror); 576284576Skp if (sp) { 577284576Skp ipsechdrsiz = ipsec_hdrsiz(mcopy, 578284576Skp IPSEC_DIR_OUTBOUND, NULL); 579284576Skp if (ipsechdrsiz < mtu) 580284576Skp mtu -= ipsechdrsiz; 581284576Skp } 582284576Skp 583284576Skp /* 584284576Skp * if mtu becomes less than minimum MTU, 585284576Skp * tell minimum MTU (and I'll need to fragment it). 586284576Skp */ 587284576Skp if (mtu < IPV6_MMTU) 588284576Skp mtu = IPV6_MMTU; 589284576Skp#endif /* IPSEC */ 590284576Skp icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); 591284576Skp } 592284576Skp goto bad; 593284576Skp } 594284576Skp 59562587Sitojun error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); 59653541Sshin if (error) { 59753541Sshin in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); 598249294Sae IP6STAT_INC(ip6s_cantforward); 59953541Sshin } else { 600249294Sae IP6STAT_INC(ip6s_forward); 60153541Sshin in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); 60253541Sshin if (type) 603249294Sae IP6STAT_INC(ip6s_redirectsent); 60453541Sshin else { 60553541Sshin if (mcopy) 60653541Sshin goto freecopy; 60753541Sshin } 60853541Sshin } 609120913Sume 61053541Sshin if (mcopy == NULL) 611187989Sbz goto out; 61253541Sshin switch (error) { 61353541Sshin case 0: 61453541Sshin if (type == ND_REDIRECT) { 61553541Sshin icmp6_redirect_output(mcopy, rt); 616187989Sbz goto out; 61753541Sshin } 61853541Sshin goto freecopy; 61953541Sshin 62053541Sshin case EMSGSIZE: 62153541Sshin /* xxx MTU is constant in PPP? */ 62253541Sshin goto freecopy; 62353541Sshin 62453541Sshin case ENOBUFS: 62553541Sshin /* Tell source to slow down like source quench in IP? */ 62653541Sshin goto freecopy; 62753541Sshin 62853541Sshin case ENETUNREACH: /* shouldn't happen, checked above */ 62953541Sshin case EHOSTUNREACH: 63053541Sshin case ENETDOWN: 63153541Sshin case EHOSTDOWN: 63253541Sshin default: 63353541Sshin type = ICMP6_DST_UNREACH; 63453541Sshin code = ICMP6_DST_UNREACH_ADDR; 63553541Sshin break; 63653541Sshin } 63753541Sshin icmp6_error(mcopy, type, code, 0); 638187989Sbz goto out; 63953541Sshin 64053541Sshin freecopy: 64153541Sshin m_freem(mcopy); 642187989Sbz goto out; 643187989Sbzbad: 644187989Sbz m_freem(m); 645187989Sbzout: 646187989Sbz if (rt != NULL 647187989Sbz#ifdef IPSEC 648187989Sbz && !ipsecrt 649187989Sbz#endif 650187989Sbz ) 651187989Sbz RTFREE(rt); 65253541Sshin} 653