]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/netinet/in_gif.c
xnu-3248.40.184.tar.gz
[apple/xnu.git] / bsd / netinet / in_gif.c
index f57a3ea283a323f0e18d93d746fd8431be3a909f..0cd7a22874af3474c83ffa75c1c2c14518c92e5b 100644 (file)
@@ -1,25 +1,31 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
- * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
- * 
- * @APPLE_LICENSE_HEADER_END@
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
-/*     $KAME: in_gif.c,v 1.27 2000/03/30 01:29:05 jinmei Exp $ */
+/* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  * SUCH DAMAGE.
  */
 
-/*
- * in_gif.c
- */
-#if BSD310
-#include "opt_mrouting.h"
-#if defined(__FreeBSD__) && __FreeBSD__ >= 3
-#include "opt_inet.h"
-#endif
-#endif
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/socket.h>
 #include <sys/sockio.h>
-#include <sys/sysctl.h>
 #include <sys/mbuf.h>
 #include <sys/errno.h>
-#ifdef __FreeBSD__
 #include <sys/kernel.h>
 #include <sys/sysctl.h>
-#endif
-#if !defined(__FreeBSD__) || __FreeBSD__ < 3
-#include <sys/ioctl.h>
-#endif
-#include <sys/protosw.h>
 
-#if defined(__FreeBSD__) && __FreeBSD__ >= 3 || defined (__APPLE__)
 #include <sys/malloc.h>
-#endif
+#include <libkern/OSAtomic.h>
 
 #include <net/if.h>
 #include <net/route.h>
-#include <net/if_gif.h>
 
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/ip6.h>
 #endif
 
-#if MROUTING
-#include <netinet/ip_mroute.h>
-#endif /* MROUTING */
-
-#include <net/if_gif.h>        
-
-#include "gif.h"
+#include <net/if_gif.h>
 
 #include <net/net_osdep.h>
 
-#if NGIF > 0
-int    ip_gif_ttl = GIF_TTL;
-#else
-int    ip_gif_ttl = 0;
-#endif
-
-extern struct protosw in_gif_protosw;
-
-SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl,
-        CTLFLAG_RW, &ip_gif_ttl , 0, "");
+int ip_gif_ttl = GIF_TTL;
+SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW | CTLFLAG_LOCKED,
+       &ip_gif_ttl,    0, "");
 
 int
-in_gif_output(ifp, family, m, rt)
-       struct ifnet    *ifp;
-       int             family;
-       struct mbuf     *m;
-       struct rtentry *rt;
+in_gif_output(
+       struct ifnet    *ifp,
+       int             family,
+       struct mbuf     *m,
+       __unused struct rtentry *rt)
 {
-       register struct gif_softc *sc = (struct gif_softc*)ifp;
-       struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
-       struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
-       struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
+       struct gif_softc *sc = ifnet_softc(ifp);
+       struct sockaddr_in *dst = (struct sockaddr_in *)
+           (void *)&sc->gif_ro.ro_dst;
+       struct sockaddr_in *sin_src = (struct sockaddr_in *)
+           (void *)sc->gif_psrc;
+       struct sockaddr_in *sin_dst = (struct sockaddr_in *)
+           (void *)sc->gif_pdst;
        struct ip iphdr;        /* capsule IP header, host byte ordered */
        int proto, error;
        u_int8_t tos;
+       struct ip_out_args ipoa =
+           { IFSCOPE_NONE, { 0 }, IPOAF_SELECT_SRCIF, 0 };
+
+       GIF_LOCK_ASSERT(sc);
 
        if (sin_src == NULL || sin_dst == NULL ||
            sin_src->sin_family != AF_INET ||
            sin_dst->sin_family != AF_INET) {
-               printf("in_gif_output: unknown family src=%x dst=%x\n", sin_src->sin_family, sin_dst->sin_family);
                m_freem(m);
-               return EAFNOSUPPORT;
+               return (EAFNOSUPPORT);
        }
 
        switch (family) {
@@ -148,94 +129,77 @@ in_gif_output(ifp, family, m, rt)
                struct ip *ip;
 
                proto = IPPROTO_IPV4;
-               if (m->m_len < sizeof(*ip)) {
-                       m = m_pullup(m, sizeof(*ip));
+               if (mbuf_len(m) < sizeof (*ip)) {
+                       m = m_pullup(m, sizeof (*ip));
                        if (!m)
-                               return ENOBUFS;
+                               return (ENOBUFS);
                }
                ip = mtod(m, struct ip *);
                tos = ip->ip_tos;
                break;
            }
-#endif /*INET*/
+#endif /* INET */
 #if INET6
        case AF_INET6:
            {
                struct ip6_hdr *ip6;
                proto = IPPROTO_IPV6;
-               if (m->m_len < sizeof(*ip6)) {
-                       m = m_pullup(m, sizeof(*ip6));
+               if (mbuf_len(m) < sizeof (*ip6)) {
+                       m = m_pullup(m, sizeof (*ip6));
                        if (!m)
-                               return ENOBUFS;
+                               return (ENOBUFS);
                }
                ip6 = mtod(m, struct ip6_hdr *);
                tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
                break;
            }
-#endif /*INET6*/
+#endif /* INET6 */
        default:
 #if DEBUG
                printf("in_gif_output: warning: unknown family %d passed\n",
                        family);
 #endif
                m_freem(m);
-               return EAFNOSUPPORT;
+               return (EAFNOSUPPORT);
        }
 
-       bzero(&iphdr, sizeof(iphdr));
+       bzero(&iphdr, sizeof (iphdr));
        iphdr.ip_src = sin_src->sin_addr;
-       if (ifp->if_flags & IFF_LINK0) {
-               /* multi-destination mode */
-               if (sin_dst->sin_addr.s_addr != INADDR_ANY)
-                       iphdr.ip_dst = sin_dst->sin_addr;
-               else if (rt) {
-                       if (family != AF_INET) {
-                               m_freem(m);
-                               return EINVAL;  /*XXX*/
-                       }
-                       iphdr.ip_dst = ((struct sockaddr_in *)
-                                       (rt->rt_gateway))->sin_addr;
-               } else {
-                       m_freem(m);
-                       return ENETUNREACH;
-               }
-       } else {
-               /* bidirectional configured tunnel mode */
-               if (sin_dst->sin_addr.s_addr != INADDR_ANY)
-                       iphdr.ip_dst = sin_dst->sin_addr;
-               else {
-                       m_freem(m);
-                       return ENETUNREACH;
-               }
+       /* bidirectional configured tunnel mode */
+       if (sin_dst->sin_addr.s_addr != INADDR_ANY)
+               iphdr.ip_dst = sin_dst->sin_addr;
+       else {
+               m_freem(m);
+               return (ENETUNREACH);
        }
        iphdr.ip_p = proto;
        /* version will be set in ip_output() */
        iphdr.ip_ttl = ip_gif_ttl;
-       iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
+       iphdr.ip_len = m->m_pkthdr.len + sizeof (struct ip);
        if (ifp->if_flags & IFF_LINK1)
-               ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
+               ip_ecn_ingress(ECN_NORMAL, &iphdr.ip_tos, &tos);
+       else
+               ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
 
        /* prepend new IP header */
-       M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
-       if (m && m->m_len < sizeof(struct ip))
-               m = m_pullup(m, sizeof(struct ip));
+       M_PREPEND(m, sizeof (struct ip), M_DONTWAIT, 0);
+       if (m && mbuf_len(m) < sizeof (struct ip))
+               m = m_pullup(m, sizeof (struct ip));
        if (m == NULL) {
                printf("ENOBUFS in in_gif_output %d\n", __LINE__);
-               return ENOBUFS;
+               return (ENOBUFS);
        }
+       bcopy(&iphdr, mtod(m, struct ip *), sizeof (struct ip));
 
-       *(mtod(m, struct ip *)) = iphdr;
-
-       if (dst->sin_family != sin_dst->sin_family ||
-           dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
-               /* cache route doesn't match */
+       if (ROUTE_UNUSABLE(&sc->gif_ro) ||
+           dst->sin_family != sin_dst->sin_family ||
+           dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr ||
+           (sc->gif_ro.ro_rt != NULL && sc->gif_ro.ro_rt->rt_ifp == ifp)) {
+               /* cache route doesn't match or recursive route */
                dst->sin_family = sin_dst->sin_family;
-               dst->sin_len = sizeof(struct sockaddr_in);
+               dst->sin_len = sizeof (struct sockaddr_in);
                dst->sin_addr = sin_dst->sin_addr;
-               if (sc->gif_ro.ro_rt) {
-                       RTFREE(sc->gif_ro.ro_rt);
-                       sc->gif_ro.ro_rt = NULL;
-               }
+               ROUTE_RELEASE(&sc->gif_ro);
 #if 0
                sc->gif_if.if_mtu = GIF_MTU;
 #endif
@@ -245,20 +209,26 @@ in_gif_output(ifp, family, m, rt)
                rtalloc(&sc->gif_ro);
                if (sc->gif_ro.ro_rt == NULL) {
                        m_freem(m);
-                       return ENETUNREACH;
+                       return (ENETUNREACH);
+               }
+
+               /* if it constitutes infinite encapsulation, punt. */
+               RT_LOCK(sc->gif_ro.ro_rt);
+               if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
+                       RT_UNLOCK(sc->gif_ro.ro_rt);
+                       m_freem(m);
+                       return (ENETUNREACH); /* XXX */
                }
 #if 0
                ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
-                       - sizeof(struct ip);
+                   - sizeof (struct ip);
 #endif
+               RT_UNLOCK(sc->gif_ro.ro_rt);
        }
 
-#ifndef __OpenBSD__
-       error = ip_output(m, NULL, &sc->gif_ro, 0, NULL);
-#else
-       error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
-#endif
-       return(error);
+       error = ip_output(m, NULL, &sc->gif_ro, IP_OUTARGS, NULL, &ipoa);
+
+       return (error);
 }
 
 void
@@ -266,75 +236,22 @@ in_gif_input(m, off)
        struct mbuf *m;
        int off;
 {
-       struct gif_softc *sc;
        struct ifnet *gifp = NULL;
        struct ip *ip;
-       int i, af, proto;
-       u_int8_t otos;
-
-       if (gif == NULL) {
-               m_freem(m);
-               return; 
-       }
+       int af, proto;
+       u_int8_t otos, old_tos;
+       int egress_success = 0;
+       int sum;
 
        ip = mtod(m, struct ip *);
-        proto = ip->ip_p;
+       proto = ip->ip_p;
 
-#if 0
-       /* this code will be soon improved. */
-#define        satosin(sa)     ((struct sockaddr_in *)(sa))    
-       for (i = 0, sc = gif; i < ngif; i++, sc++) {
-               if (sc->gif_psrc == NULL
-                || sc->gif_pdst == NULL
-                || sc->gif_psrc->sa_family != AF_INET
-                || sc->gif_pdst->sa_family != AF_INET) {
-                       continue;
-               }
 
-               if ((sc->gif_if.if_flags & IFF_UP) == 0)
-                       continue;
+       gifp = ((struct gif_softc *)encap_getarg(m))->gif_if;
 
-               if ((sc->gif_if.if_flags & IFF_LINK0)
-                && satosin(sc->gif_psrc)->sin_addr.s_addr == ip->ip_dst.s_addr
-                && satosin(sc->gif_pdst)->sin_addr.s_addr == INADDR_ANY) {
-                       gifp = &sc->gif_if;
-                       continue;
-               }
-
-               if (satosin(sc->gif_psrc)->sin_addr.s_addr == ip->ip_dst.s_addr
-                && satosin(sc->gif_pdst)->sin_addr.s_addr == ip->ip_src.s_addr)
-               {
-                       gifp = &sc->gif_if;
-                       break;
-               }
-       }
-#else
-       gifp = (struct ifnet *)encap_getarg(m);
-#endif
-
-       if (gifp == NULL) {
-               /* for backward compatibility */
-               if (proto == IPPROTO_IPV4) {
-#ifdef __OpenBSD__
-#if defined(MROUTING) || defined(IPSEC)
-                       ip4_input(m, off, proto);
-                       return;
-#endif
-#else
-#if MROUTING
-                       ipip_input(m, off);
-                       return;
-#endif /*MROUTING*/
-#endif
-               }
+       if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
                m_freem(m);
-               ipstat.ips_nogif++;
-               return;
-       }
-
-       if ((gifp->if_flags & IFF_UP) == 0) {
-               m_freem(m);
-               ipstat.ips_nogif++;
+               OSAddAtomic(1, &ipstat.ips_nogif);
                return;
        }
 
@@ -345,16 +262,25 @@ in_gif_input(m, off)
 #if INET
        case IPPROTO_IPV4:
            {
-               struct ip *ip;
                af = AF_INET;
-               if (m->m_len < sizeof(*ip)) {
-                       m = m_pullup(m, sizeof(*ip));
+               if (mbuf_len(m) < sizeof (*ip)) {
+                       m = m_pullup(m, sizeof (*ip));
                        if (!m)
                                return;
                }
                ip = mtod(m, struct ip *);
-               if (gifp->if_flags & IFF_LINK1)
-                       ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
+               if (gifp->if_flags & IFF_LINK1) {
+                       old_tos = ip->ip_tos;
+                       egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &ip->ip_tos);
+                       if (old_tos != ip->ip_tos) {
+                           sum = ~ntohs(ip->ip_sum) & 0xffff;
+                           sum += (~otos & 0xffff) + ip->ip_tos;
+                           sum = (sum >> 16) + (sum & 0xffff);
+                           sum += (sum >> 16);  /* add carry */
+                           ip->ip_sum = htons(~sum & 0xffff);
+                       }
+               } else
+                       egress_success = ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
                break;
            }
 #endif
@@ -364,143 +290,126 @@ in_gif_input(m, off)
                struct ip6_hdr *ip6;
                u_int8_t itos;
                af = AF_INET6;
-               if (m->m_len < sizeof(*ip6)) {
-                       m = m_pullup(m, sizeof(*ip6));
+               if (mbuf_len(m) < sizeof (*ip6)) {
+                       m = m_pullup(m, sizeof (*ip6));
                        if (!m)
                                return;
                }
                ip6 = mtod(m, struct ip6_hdr *);
                itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
                if (gifp->if_flags & IFF_LINK1)
-                       ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
+                       egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &itos);
+               else
+                       egress_success = ip_ecn_egress(ECN_NOCARE, &otos, &itos);
                ip6->ip6_flow &= ~htonl(0xff << 20);
                ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
                break;
            }
 #endif /* INET6 */
        default:
-               ipstat.ips_nogif++;
+               OSAddAtomic(1, &ipstat.ips_nogif);
+               m_freem(m);
+               return;
+       }
+
+       if (egress_success == 0) {
+               OSAddAtomic(1, &ipstat.ips_nogif);
                m_freem(m);
                return;
        }
+
+#ifdef __APPLE__
+       /* Replace the rcvif by gifp for dlil to route it correctly */
+       if (m->m_pkthdr.rcvif)
+               m->m_pkthdr.rcvif = gifp;
+       ifnet_input(gifp, m, NULL);
+#else
        gif_input(m, af, gifp);
-       return;
+#endif
 }
 
+/*
+ * We know that we are in IFF_UP, outer address available, and outer family
+ * matched the physical addr family.  see gif_encapcheck().
+ */
 int
-in_gif_ioctl(ifp, cmd, data)
-       struct ifnet *ifp;
-#if defined(__FreeBSD__) && __FreeBSD__ < 3
-       int cmd;
-#else
-       u_long cmd;
-#endif
-       caddr_t data;
+gif_encapcheck4(
+       const struct mbuf *m,
+       __unused int off,
+       __unused int proto,
+       void *arg)
 {
-       struct gif_softc *sc  = (struct gif_softc*)ifp;
-       struct ifreq     *ifr = (struct ifreq*)data;
-       int error = 0, size;
-       struct sockaddr *sa, *dst, *src;
-       const struct encaptab *p;
-       struct sockaddr_in smask4, dmask4;
-               
-       switch (cmd) {
-       case SIOCSIFFLAGS:
-               /*
-                * whenever we change our idea about multi-destination mode
-                * we need to update encap attachment.
-                */
-               if (((ifp->if_flags ^ sc->gif_oflags) & IFF_LINK0) == 0)
-                       break;
-               if (sc->gif_psrc == NULL || sc->gif_pdst == NULL ||
-                   sc->gif_psrc->sa_family != sc->gif_pdst->sa_family)
-                       break;
-               bzero(&smask4, sizeof(smask4));
-               smask4.sin_addr.s_addr = ~0;
-               dmask4 = smask4;
-               if ((ifp->if_flags & IFF_LINK0) != 0 &&
-                   ((struct sockaddr_in *)dst)->sin_addr.s_addr ==
-                               INADDR_ANY) {
-                       bzero(&dmask4, sizeof(dmask4));
-               }
-               p = encap_attach(sc->gif_psrc->sa_family, -1, sc->gif_psrc,
-                       (struct sockaddr *)&smask4, sc->gif_pdst,
-                       (struct sockaddr *)&dmask4,
-                       (struct protosw *)&in_gif_protosw, &sc->gif_if);
-               if (p == NULL) {
-                       error = EINVAL;
-                       goto bad;
+       struct ip ip;
+       struct gif_softc *sc;
+       struct sockaddr_in *src, *dst;
+       int addrmatch;
+       struct in_ifaddr *ia4;
+
+       /* sanity check done in caller */
+       sc = (struct gif_softc *)arg;
+       src = (struct sockaddr_in *)(void *)sc->gif_psrc;
+       dst = (struct sockaddr_in *)(void *)sc->gif_pdst;
+
+       GIF_LOCK_ASSERT(sc);
+
+       mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof (ip), &ip);
+
+       /* check for address match */
+       addrmatch = 0;
+       if (src->sin_addr.s_addr == ip.ip_dst.s_addr)
+               addrmatch |= 1;
+       if (dst->sin_addr.s_addr == ip.ip_src.s_addr)
+               addrmatch |= 2;
+       if (addrmatch != 3)
+               return (0);
+
+       /* martian filters on outer source - NOT done in ip_input! */
+       if (IN_MULTICAST(ntohl(ip.ip_src.s_addr)))
+               return (0);
+       switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) {
+       case 0: case 127: case 255:
+               return (0);
+       }
+       /* reject packets with broadcast on source */
+       lck_rw_lock_shared(in_ifaddr_rwlock);
+       for (ia4 = TAILQ_FIRST(&in_ifaddrhead); ia4;
+           ia4 = TAILQ_NEXT(ia4, ia_link)) {
+               if ((ifnet_flags(ia4->ia_ifa.ifa_ifp) & IFF_BROADCAST) == 0)
+                       continue;
+               IFA_LOCK(&ia4->ia_ifa);
+               if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
+                       IFA_UNLOCK(&ia4->ia_ifa);
+                       lck_rw_done(in_ifaddr_rwlock);
+                       return (0);
                }
-               if (sc->encap_cookie != NULL)
-                       (void)encap_detach(sc->encap_cookie);
-               sc->encap_cookie = p;
-               sc->gif_oflags = ifp->if_flags;
-
-               break;
-
-       case SIOCSIFPHYADDR:
-               switch (ifr->ifr_addr.sa_family) {
-               case AF_INET:
-                       src = (struct sockaddr *)
-                               &(((struct in_aliasreq *)data)->ifra_addr);
-                       dst = (struct sockaddr *)
-                               &(((struct in_aliasreq *)data)->ifra_dstaddr);
-
-                       bzero(&smask4, sizeof(smask4));
-                       smask4.sin_addr.s_addr = ~0;
-                       dmask4 = smask4;
-                       if ((ifp->if_flags & IFF_LINK0) != 0 &&
-                           ((struct sockaddr_in *)dst)->sin_addr.s_addr ==
-                                       INADDR_ANY) {
-                               bzero(&dmask4, sizeof(dmask4));
+               IFA_UNLOCK(&ia4->ia_ifa);
+       }
+       lck_rw_done(in_ifaddr_rwlock);
+
+       /* ingress filters on outer source */
+       if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 &&
+           (m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) {
+               struct sockaddr_in sin;
+               struct rtentry *rt;
+
+               bzero(&sin, sizeof (sin));
+               sin.sin_family = AF_INET;
+               sin.sin_len = sizeof (struct sockaddr_in);
+               sin.sin_addr = ip.ip_src;
+               rt = rtalloc1_scoped((struct sockaddr *)&sin, 0, 0,
+                   m->m_pkthdr.rcvif->if_index);
+               if (rt != NULL)
+                       RT_LOCK(rt);
+               if (rt == NULL || rt->rt_ifp != m->m_pkthdr.rcvif) {
+                       if (rt != NULL) {
+                               RT_UNLOCK(rt);
+                               rtfree(rt);
                        }
-                       size = sizeof(struct sockaddr_in);
-                       break;
-               default:
-                       error = EAFNOSUPPORT;
-                       goto bad;
-               }
-
-               if (sc->encap_cookie)
-                       (void)encap_detach(sc->encap_cookie);
-               if (sc->gif_psrc != NULL) {
-                       _FREE((caddr_t)sc->gif_psrc, M_IFADDR);
-                       sc->gif_psrc = NULL;
+                       return (0);
                }
-               if (sc->gif_pdst != NULL) {
-                       _FREE((caddr_t)sc->gif_pdst, M_IFADDR);
-                       sc->gif_pdst = NULL;
-               }
-
-               p = encap_attach(ifr->ifr_addr.sa_family, -1, src,
-                       (struct sockaddr *)&smask4, dst,
-                       (struct sockaddr *)&dmask4,
-                       (struct protosw *)&in_gif_protosw, &sc->gif_if);
-               if (p == NULL) {
-                       error = EINVAL;
-                       goto bad;
-               }
-               sc->encap_cookie = p;
-               sc->gif_oflags = ifp->if_flags;
-
-               sa = (struct sockaddr *)_MALLOC(size, M_IFADDR, M_WAITOK);
-               bcopy((caddr_t)src, (caddr_t)sa, size);
-               sc->gif_psrc = sa;
-               
-               sa = (struct sockaddr *)_MALLOC(size, M_IFADDR, M_WAITOK);
-               bcopy((caddr_t)dst, (caddr_t)sa, size);
-               sc->gif_pdst = sa;
-               
-               ifp->if_flags |= IFF_UP;
-               if_up(ifp);             /* send up RTM_IFINFO */
-
-               error = 0;
-               break;
-       default:
-               error = EINVAL;
-               goto bad;
+               RT_UNLOCK(rt);
+               rtfree(rt);
        }
 
- bad:
-       return error;
+       return (32 * 2);
 }