The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/netinet6/ip6_forward.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. Neither the name of the project nor the names of its contributors
   14  *    may be used to endorse or promote products derived from this software
   15  *    without specific prior written permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  *
   29  *      $KAME: ip6_forward.c,v 1.69 2001/05/17 03:48:30 itojun Exp $
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD: releng/8.3/sys/netinet6/ip6_forward.c 203605 2010-02-07 09:00:22Z julian $");
   34 
   35 #include "opt_inet.h"
   36 #include "opt_inet6.h"
   37 #include "opt_ipsec.h"
   38 #include "opt_ipstealth.h"
   39 
   40 #include <sys/param.h>
   41 #include <sys/systm.h>
   42 #include <sys/malloc.h>
   43 #include <sys/mbuf.h>
   44 #include <sys/domain.h>
   45 #include <sys/protosw.h>
   46 #include <sys/socket.h>
   47 #include <sys/errno.h>
   48 #include <sys/time.h>
   49 #include <sys/kernel.h>
   50 #include <sys/syslog.h>
   51 
   52 #include <net/if.h>
   53 #include <net/route.h>
   54 #include <net/pfil.h>
   55 
   56 #include <netinet/in.h>
   57 #include <netinet/in_var.h>
   58 #include <netinet/in_systm.h>
   59 #include <netinet/ip.h>
   60 #include <netinet/ip_var.h>
   61 #include <netinet6/in6_var.h>
   62 #include <netinet/ip6.h>
   63 #include <netinet6/ip6_var.h>
   64 #include <netinet6/scope6_var.h>
   65 #include <netinet/icmp6.h>
   66 #include <netinet6/nd6.h>
   67 
   68 #include <netinet/in_pcb.h>
   69 
   70 #ifdef IPSEC
   71 #include <netipsec/ipsec.h>
   72 #include <netipsec/ipsec6.h>
   73 #include <netipsec/key.h>
   74 #endif /* IPSEC */
   75 
   76 #include <netinet6/ip6protosw.h>
   77 
   78 /*
   79  * Forward a packet.  If some error occurs return the sender
   80  * an icmp packet.  Note we can't always generate a meaningful
   81  * icmp message because icmp doesn't have a large enough repertoire
   82  * of codes and types.
   83  *
   84  * If not forwarding, just drop the packet.  This could be confusing
   85  * if ipforwarding was zero but some routing protocol was advancing
   86  * us as a gateway to somewhere.  However, we must let the routing
   87  * protocol deal with that.
   88  *
   89  */
   90 void
   91 ip6_forward(struct mbuf *m, int srcrt)
   92 {
   93         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   94         struct sockaddr_in6 *dst = NULL;
   95         struct rtentry *rt = NULL;
   96         struct route_in6 rin6;
   97         int error, type = 0, code = 0;
   98         struct mbuf *mcopy = NULL;
   99         struct ifnet *origifp;  /* maybe unnecessary */
  100         u_int32_t inzone, outzone;
  101         struct in6_addr src_in6, dst_in6;
  102 #ifdef IPSEC
  103         struct secpolicy *sp = NULL;
  104         int ipsecrt = 0;
  105 #endif
  106         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  107 
  108 #ifdef IPSEC
  109         /*
  110          * Check AH/ESP integrity.
  111          */
  112         /*
  113          * Don't increment ip6s_cantforward because this is the check
  114          * before forwarding packet actually.
  115          */
  116         if (ipsec6_in_reject(m, NULL)) {
  117                 V_ipsec6stat.in_polvio++;
  118                 m_freem(m);
  119                 return;
  120         }
  121 #endif /* IPSEC */
  122 
  123         /*
  124          * Do not forward packets to multicast destination (should be handled
  125          * by ip6_mforward().
  126          * Do not forward packets with unspecified source.  It was discussed
  127          * in July 2000, on the ipngwg mailing list.
  128          */
  129         if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 ||
  130             IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
  131             IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) {
  132                 V_ip6stat.ip6s_cantforward++;
  133                 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
  134                 if (V_ip6_log_time + V_ip6_log_interval < time_second) {
  135                         V_ip6_log_time = time_second;
  136                         log(LOG_DEBUG,
  137                             "cannot forward "
  138                             "from %s to %s nxt %d received on %s\n",
  139                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
  140                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
  141                             ip6->ip6_nxt,
  142                             if_name(m->m_pkthdr.rcvif));
  143                 }
  144                 m_freem(m);
  145                 return;
  146         }
  147 
  148 #ifdef IPSTEALTH
  149         if (!V_ip6stealth) {
  150 #endif
  151         if (ip6->ip6_hlim <= IPV6_HLIMDEC) {
  152                 /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
  153                 icmp6_error(m, ICMP6_TIME_EXCEEDED,
  154                                 ICMP6_TIME_EXCEED_TRANSIT, 0);
  155                 return;
  156         }
  157         ip6->ip6_hlim -= IPV6_HLIMDEC;
  158 
  159 #ifdef IPSTEALTH
  160         }
  161 #endif
  162 
  163         /*
  164          * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU -
  165          * size of IPv6 + ICMPv6 headers) bytes of the packet in case
  166          * we need to generate an ICMP6 message to the src.
  167          * Thanks to M_EXT, in most cases copy will not occur.
  168          *
  169          * It is important to save it before IPsec processing as IPsec
  170          * processing may modify the mbuf.
  171          */
  172         mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN));
  173 
  174 #ifdef IPSEC
  175         /* get a security policy for this packet */
  176         sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND,
  177             IP_FORWARDING, &error);
  178         if (sp == NULL) {
  179                 V_ipsec6stat.out_inval++;
  180                 V_ip6stat.ip6s_cantforward++;
  181                 if (mcopy) {
  182 #if 0
  183                         /* XXX: what icmp ? */
  184 #else
  185                         m_freem(mcopy);
  186 #endif
  187                 }
  188                 m_freem(m);
  189                 return;
  190         }
  191 
  192         error = 0;
  193 
  194         /* check policy */
  195         switch (sp->policy) {
  196         case IPSEC_POLICY_DISCARD:
  197                 /*
  198                  * This packet is just discarded.
  199                  */
  200                 V_ipsec6stat.out_polvio++;
  201                 V_ip6stat.ip6s_cantforward++;
  202                 KEY_FREESP(&sp);
  203                 if (mcopy) {
  204 #if 0
  205                         /* XXX: what icmp ? */
  206 #else
  207                         m_freem(mcopy);
  208 #endif
  209                 }
  210                 m_freem(m);
  211                 return;
  212 
  213         case IPSEC_POLICY_BYPASS:
  214         case IPSEC_POLICY_NONE:
  215                 /* no need to do IPsec. */
  216                 KEY_FREESP(&sp);
  217                 goto skip_ipsec;
  218 
  219         case IPSEC_POLICY_IPSEC:
  220                 if (sp->req == NULL) {
  221                         /* XXX should be panic ? */
  222                         printf("ip6_forward: No IPsec request specified.\n");
  223                         V_ip6stat.ip6s_cantforward++;
  224                         KEY_FREESP(&sp);
  225                         if (mcopy) {
  226 #if 0
  227                                 /* XXX: what icmp ? */
  228 #else
  229                                 m_freem(mcopy);
  230 #endif
  231                         }
  232                         m_freem(m);
  233                         return;
  234                 }
  235                 /* do IPsec */
  236                 break;
  237 
  238         case IPSEC_POLICY_ENTRUST:
  239         default:
  240                 /* should be panic ?? */
  241                 printf("ip6_forward: Invalid policy found. %d\n", sp->policy);
  242                 KEY_FREESP(&sp);
  243                 goto skip_ipsec;
  244         }
  245 
  246     {
  247         struct ipsecrequest *isr = NULL;
  248         struct ipsec_output_state state;
  249 
  250         /*
  251          * when the kernel forwards a packet, it is not proper to apply
  252          * IPsec transport mode to the packet is not proper.  this check
  253          * avoid from this.
  254          * at present, if there is even a transport mode SA request in the
  255          * security policy, the kernel does not apply IPsec to the packet.
  256          * this check is not enough because the following case is valid.
  257          *      ipsec esp/tunnel/xxx-xxx/require esp/transport//require;
  258          */
  259         for (isr = sp->req; isr; isr = isr->next) {
  260                 if (isr->saidx.mode == IPSEC_MODE_ANY)
  261                         goto doipsectunnel;
  262                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
  263                         goto doipsectunnel;
  264         }
  265 
  266         /*
  267          * if there's no need for tunnel mode IPsec, skip.
  268          */
  269         if (!isr)
  270                 goto skip_ipsec;
  271 
  272     doipsectunnel:
  273         /*
  274          * All the extension headers will become inaccessible
  275          * (since they can be encrypted).
  276          * Don't panic, we need no more updates to extension headers
  277          * on inner IPv6 packet (since they are now encapsulated).
  278          *
  279          * IPv6 [ESP|AH] IPv6 [extension headers] payload
  280          */
  281         bzero(&state, sizeof(state));
  282         state.m = m;
  283         state.ro = NULL;        /* update at ipsec6_output_tunnel() */
  284         state.dst = NULL;       /* update at ipsec6_output_tunnel() */
  285 
  286         error = ipsec6_output_tunnel(&state, sp, 0);
  287 
  288         m = state.m;
  289         KEY_FREESP(&sp);
  290 
  291         if (error) {
  292                 /* mbuf is already reclaimed in ipsec6_output_tunnel. */
  293                 switch (error) {
  294                 case EHOSTUNREACH:
  295                 case ENETUNREACH:
  296                 case EMSGSIZE:
  297                 case ENOBUFS:
  298                 case ENOMEM:
  299                         break;
  300                 default:
  301                         printf("ip6_output (ipsec): error code %d\n", error);
  302                         /* FALLTHROUGH */
  303                 case ENOENT:
  304                         /* don't show these error codes to the user */
  305                         break;
  306                 }
  307                 V_ip6stat.ip6s_cantforward++;
  308                 if (mcopy) {
  309 #if 0
  310                         /* XXX: what icmp ? */
  311 #else
  312                         m_freem(mcopy);
  313 #endif
  314                 }
  315                 m_freem(m);
  316                 return;
  317         } else {
  318                 /*
  319                  * In the FAST IPSec case we have already
  320                  * re-injected the packet and it has been freed
  321                  * by the ipsec_done() function.  So, just clean
  322                  * up after ourselves.
  323                  */
  324                 m = NULL;
  325                 goto freecopy;
  326         }
  327 
  328         if ((m != NULL) && (ip6 != mtod(m, struct ip6_hdr *)) ){
  329                 /*
  330                  * now tunnel mode headers are added.  we are originating
  331                  * packet instead of forwarding the packet.
  332                  */
  333                 ip6_output(m, NULL, NULL, IPV6_FORWARDING/*XXX*/, NULL, NULL,
  334                     NULL);
  335                 goto freecopy;
  336         }
  337 
  338         /* adjust pointer */
  339         dst = (struct sockaddr_in6 *)state.dst;
  340         rt = state.ro ? state.ro->ro_rt : NULL;
  341         if (dst != NULL && rt != NULL)
  342                 ipsecrt = 1;
  343     }
  344         if (ipsecrt)
  345                 goto skip_routing;
  346 skip_ipsec:
  347 #endif
  348 
  349         bzero(&rin6, sizeof(struct route_in6));
  350         dst = (struct sockaddr_in6 *)&rin6.ro_dst;
  351         dst->sin6_len = sizeof(struct sockaddr_in6);
  352         dst->sin6_family = AF_INET6;
  353         dst->sin6_addr = ip6->ip6_dst;
  354 
  355         rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0);
  356         if (rin6.ro_rt != NULL)
  357                 RT_UNLOCK(rin6.ro_rt);
  358         else {
  359                 V_ip6stat.ip6s_noroute++;
  360                 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute);
  361                 if (mcopy) {
  362                         icmp6_error(mcopy, ICMP6_DST_UNREACH,
  363                         ICMP6_DST_UNREACH_NOROUTE, 0);
  364                 }
  365                 goto bad;
  366         }
  367         rt = rin6.ro_rt;
  368 #ifdef IPSEC
  369 skip_routing:
  370 #endif
  371 
  372         /*
  373          * Source scope check: if a packet can't be delivered to its
  374          * destination for the reason that the destination is beyond the scope
  375          * of the source address, discard the packet and return an icmp6
  376          * destination unreachable error with Code 2 (beyond scope of source
  377          * address).  We use a local copy of ip6_src, since in6_setscope()
  378          * will possibly modify its first argument.
  379          * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1]
  380          */
  381         src_in6 = ip6->ip6_src;
  382         if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) {
  383                 /* XXX: this should not happen */
  384                 V_ip6stat.ip6s_cantforward++;
  385                 V_ip6stat.ip6s_badscope++;
  386                 goto bad;
  387         }
  388         if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) {
  389                 V_ip6stat.ip6s_cantforward++;
  390                 V_ip6stat.ip6s_badscope++;
  391                 goto bad;
  392         }
  393         if (inzone != outzone
  394 #ifdef IPSEC
  395             && !ipsecrt
  396 #endif
  397             ) {
  398                 V_ip6stat.ip6s_cantforward++;
  399                 V_ip6stat.ip6s_badscope++;
  400                 in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard);
  401 
  402                 if (V_ip6_log_time + V_ip6_log_interval < time_second) {
  403                         V_ip6_log_time = time_second;
  404                         log(LOG_DEBUG,
  405                             "cannot forward "
  406                             "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
  407                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
  408                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
  409                             ip6->ip6_nxt,
  410                             if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp));
  411                 }
  412                 if (mcopy)
  413                         icmp6_error(mcopy, ICMP6_DST_UNREACH,
  414                                     ICMP6_DST_UNREACH_BEYONDSCOPE, 0);
  415                 goto bad;
  416         }
  417 
  418         /*
  419          * Destination scope check: if a packet is going to break the scope
  420          * zone of packet's destination address, discard it.  This case should
  421          * usually be prevented by appropriately-configured routing table, but
  422          * we need an explicit check because we may mistakenly forward the
  423          * packet to a different zone by (e.g.) a default route.
  424          */
  425         dst_in6 = ip6->ip6_dst;
  426         if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 ||
  427             in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 ||
  428             inzone != outzone) {
  429                 V_ip6stat.ip6s_cantforward++;
  430                 V_ip6stat.ip6s_badscope++;
  431                 goto bad;
  432         }
  433 
  434         if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) {
  435                 in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig);
  436                 if (mcopy) {
  437                         u_long mtu;
  438 #ifdef IPSEC
  439                         struct secpolicy *sp;
  440                         int ipsecerror;
  441                         size_t ipsechdrsiz;
  442 #endif /* IPSEC */
  443 
  444                         mtu = IN6_LINKMTU(rt->rt_ifp);
  445 #ifdef IPSEC
  446                         /*
  447                          * When we do IPsec tunnel ingress, we need to play
  448                          * with the link value (decrement IPsec header size
  449                          * from mtu value).  The code is much simpler than v4
  450                          * case, as we have the outgoing interface for
  451                          * encapsulated packet as "rt->rt_ifp".
  452                          */
  453                         sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND,
  454                                 IP_FORWARDING, &ipsecerror);
  455                         if (sp) {
  456                                 ipsechdrsiz = ipsec_hdrsiz(mcopy,
  457                                         IPSEC_DIR_OUTBOUND, NULL);
  458                                 if (ipsechdrsiz < mtu)
  459                                         mtu -= ipsechdrsiz;
  460                         }
  461 
  462                         /*
  463                          * if mtu becomes less than minimum MTU,
  464                          * tell minimum MTU (and I'll need to fragment it).
  465                          */
  466                         if (mtu < IPV6_MMTU)
  467                                 mtu = IPV6_MMTU;
  468 #endif /* IPSEC */
  469                         icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu);
  470                 }
  471                 goto bad;
  472         }
  473 
  474         if (rt->rt_flags & RTF_GATEWAY)
  475                 dst = (struct sockaddr_in6 *)rt->rt_gateway;
  476 
  477         /*
  478          * If we are to forward the packet using the same interface
  479          * as one we got the packet from, perhaps we should send a redirect
  480          * to sender to shortcut a hop.
  481          * Only send redirect if source is sending directly to us,
  482          * and if packet was not source routed (or has any options).
  483          * Also, don't send redirect if forwarding using a route
  484          * modified by a redirect.
  485          */
  486         if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt &&
  487 #ifdef IPSEC
  488             !ipsecrt &&
  489 #endif /* IPSEC */
  490             (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) {
  491                 if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) {
  492                         /*
  493                          * If the incoming interface is equal to the outgoing
  494                          * one, and the link attached to the interface is
  495                          * point-to-point, then it will be highly probable
  496                          * that a routing loop occurs. Thus, we immediately
  497                          * drop the packet and send an ICMPv6 error message.
  498                          *
  499                          * type/code is based on suggestion by Rich Draves.
  500                          * not sure if it is the best pick.
  501                          */
  502                         icmp6_error(mcopy, ICMP6_DST_UNREACH,
  503                                     ICMP6_DST_UNREACH_ADDR, 0);
  504                         goto bad;
  505                 }
  506                 type = ND_REDIRECT;
  507         }
  508 
  509         /*
  510          * Fake scoped addresses. Note that even link-local source or
  511          * destinaion can appear, if the originating node just sends the
  512          * packet to us (without address resolution for the destination).
  513          * Since both icmp6_error and icmp6_redirect_output fill the embedded
  514          * link identifiers, we can do this stuff after making a copy for
  515          * returning an error.
  516          */
  517         if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) {
  518                 /*
  519                  * See corresponding comments in ip6_output.
  520                  * XXX: but is it possible that ip6_forward() sends a packet
  521                  *      to a loopback interface? I don't think so, and thus
  522                  *      I bark here. (jinmei@kame.net)
  523                  * XXX: it is common to route invalid packets to loopback.
  524                  *      also, the codepath will be visited on use of ::1 in
  525                  *      rthdr. (itojun)
  526                  */
  527 #if 1
  528                 if (0)
  529 #else
  530                 if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0)
  531 #endif
  532                 {
  533                         printf("ip6_forward: outgoing interface is loopback. "
  534                                "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
  535                                ip6_sprintf(ip6bufs, &ip6->ip6_src),
  536                                ip6_sprintf(ip6bufd, &ip6->ip6_dst),
  537                                ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif),
  538                                if_name(rt->rt_ifp));
  539                 }
  540 
  541                 /* we can just use rcvif in forwarding. */
  542                 origifp = m->m_pkthdr.rcvif;
  543         }
  544         else
  545                 origifp = rt->rt_ifp;
  546         /*
  547          * clear embedded scope identifiers if necessary.
  548          * in6_clearscope will touch the addresses only when necessary.
  549          */
  550         in6_clearscope(&ip6->ip6_src);
  551         in6_clearscope(&ip6->ip6_dst);
  552 
  553         /* Jump over all PFIL processing if hooks are not active. */
  554         if (!PFIL_HOOKED(&V_inet6_pfil_hook))
  555                 goto pass;
  556 
  557         /* Run through list of hooks for output packets. */
  558         error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL);
  559         if (error != 0)
  560                 goto senderr;
  561         if (m == NULL)
  562                 goto freecopy;
  563         ip6 = mtod(m, struct ip6_hdr *);
  564 
  565 pass:
  566         error = nd6_output(rt->rt_ifp, origifp, m, dst, rt);
  567         if (error) {
  568                 in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard);
  569                 V_ip6stat.ip6s_cantforward++;
  570         } else {
  571                 V_ip6stat.ip6s_forward++;
  572                 in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward);
  573                 if (type)
  574                         V_ip6stat.ip6s_redirectsent++;
  575                 else {
  576                         if (mcopy)
  577                                 goto freecopy;
  578                 }
  579         }
  580 
  581 senderr:
  582         if (mcopy == NULL)
  583                 goto out;
  584         switch (error) {
  585         case 0:
  586                 if (type == ND_REDIRECT) {
  587                         icmp6_redirect_output(mcopy, rt);
  588                         goto out;
  589                 }
  590                 goto freecopy;
  591 
  592         case EMSGSIZE:
  593                 /* xxx MTU is constant in PPP? */
  594                 goto freecopy;
  595 
  596         case ENOBUFS:
  597                 /* Tell source to slow down like source quench in IP? */
  598                 goto freecopy;
  599 
  600         case ENETUNREACH:       /* shouldn't happen, checked above */
  601         case EHOSTUNREACH:
  602         case ENETDOWN:
  603         case EHOSTDOWN:
  604         default:
  605                 type = ICMP6_DST_UNREACH;
  606                 code = ICMP6_DST_UNREACH_ADDR;
  607                 break;
  608         }
  609         icmp6_error(mcopy, type, code, 0);
  610         goto out;
  611 
  612  freecopy:
  613         m_freem(mcopy);
  614         goto out;
  615 bad:
  616         m_freem(m);
  617 out:
  618         if (rt != NULL
  619 #ifdef IPSEC
  620             && !ipsecrt
  621 #endif
  622             )
  623                 RTFREE(rt);
  624 }

Cache object: 89f721599e35740eb98c008f08470578


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.