bsd/netinet6/in6_gif.c

   1 /*      $FreeBSD: src/sys/netinet6/in6_gif.c,v 1.2.2.3 2001/07/03 11:01:52 ume Exp $    */
   2 /*      $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $        */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36 #include <sys/socket.h>
  37 #include <sys/sockio.h>
  38 #include <sys/mbuf.h>
  39 #include <sys/errno.h>
  40 #include <sys/queue.h>
  41 #include <sys/syslog.h>
  42
  43 #include <sys/malloc.h>
  44 #include <sys/protosw.h>
  45
  46 #include <net/if.h>
  47 #include <net/route.h>
  48
  49 #include <netinet/in.h>
  50 #include <netinet/in_systm.h>
  51 #if INET
  52 #include <netinet/ip.h>
  53 #endif
  54 #include <netinet/ip_encap.h>
  55 #if INET6
  56 #include <netinet/ip6.h>
  57 #include <netinet6/ip6_var.h>
  58 #include <netinet6/in6_gif.h>
  59 #include <netinet6/in6_var.h>
  60 #endif
  61 #include <netinet/ip_ecn.h>
  62 #if INET6
  63 #include <netinet6/ip6_ecn.h>
  64 #endif
  65
  66 #include <net/if_gif.h>
  67
  68 #include <net/net_osdep.h>
  69
  70 int
  71 in6_gif_output(
  72         struct ifnet *ifp,
  73         int family, /* family of the packet to be encapsulate. */
  74         struct mbuf *m,
  75         struct rtentry *rt)
  76 {
  77         struct gif_softc *sc = (struct gif_softc*)ifp;
  78         struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
  79         struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
  80         struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
  81         struct ip6_hdr *ip6;
  82         int proto;
  83         u_int8_t itos, otos;
  84
  85         if (sin6_src == NULL || sin6_dst == NULL ||
  86             sin6_src->sin6_family != AF_INET6 ||
  87             sin6_dst->sin6_family != AF_INET6) {
  88                 m_freem(m);
  89                 return EAFNOSUPPORT;
  90         }
  91
  92         switch (family) {
  93 #if INET
  94         case AF_INET:
  95             {
  96                 struct ip *ip;
  97
  98                 proto = IPPROTO_IPV4;
  99                 if (m->m_len < sizeof(*ip)) {
 100                         m = m_pullup(m, sizeof(*ip));
 101                         if (!m)
 102                                 return ENOBUFS;
 103                 }
 104                 ip = mtod(m, struct ip *);
 105                 itos = ip->ip_tos;
 106                 break;
 107             }
 108 #endif
 109 #if INET6
 110         case AF_INET6:
 111             {
 112                 struct ip6_hdr *ip6;
 113                 proto = IPPROTO_IPV6;
 114                 if (m->m_len < sizeof(*ip6)) {
 115                         m = m_pullup(m, sizeof(*ip6));
 116                         if (!m)
 117                                 return ENOBUFS;
 118                 }
 119                 ip6 = mtod(m, struct ip6_hdr *);
 120                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 121                 break;
 122             }
 123 #endif
 124         default:
 125 #if DEBUG
 126                 printf("in6_gif_output: warning: unknown family %d passed\n",
 127                         family);
 128 #endif
 129                 m_freem(m);
 130                 return EAFNOSUPPORT;
 131         }
 132
 133         /* prepend new IP header */
 134         M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
 135         if (m && m->m_len < sizeof(struct ip6_hdr))
 136                 m = m_pullup(m, sizeof(struct ip6_hdr));
 137         if (m == NULL) {
 138                 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
 139                 return ENOBUFS;
 140         }
 141
 142         ip6 = mtod(m, struct ip6_hdr *);
 143         ip6->ip6_flow   = 0;
 144         ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 145         ip6->ip6_vfc    |= IPV6_VERSION;
 146         ip6->ip6_plen   = htons((u_short)m->m_pkthdr.len);
 147         ip6->ip6_nxt    = proto;
 148         ip6->ip6_hlim   = ip6_gif_hlim;
 149         ip6->ip6_src    = sin6_src->sin6_addr;
 150         /* bidirectional configured tunnel mode */
 151         if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
 152                 ip6->ip6_dst = sin6_dst->sin6_addr;
 153         else  {
 154                 m_freem(m);
 155                 return ENETUNREACH;
 156         }
 157         if (ifp->if_flags & IFF_LINK1)
 158                 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
 159         else
 160                 ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
 161         ip6->ip6_flow &= ~ntohl(0xff00000);
 162         ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
 163
 164         if (dst->sin6_family != sin6_dst->sin6_family ||
 165              !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
 166                 /* cache route doesn't match */
 167                 bzero(dst, sizeof(*dst));
 168                 dst->sin6_family = sin6_dst->sin6_family;
 169                 dst->sin6_len = sizeof(struct sockaddr_in6);
 170                 dst->sin6_addr = sin6_dst->sin6_addr;
 171                 if (sc->gif_ro6.ro_rt) {
 172                         rtfree(sc->gif_ro6.ro_rt);
 173                         sc->gif_ro6.ro_rt = NULL;
 174                 }
 175 #if 0
 176                 sc->gif_if.if_mtu = GIF_MTU;
 177 #endif
 178         }
 179
 180         if (sc->gif_ro6.ro_rt == NULL) {
 181                 rtalloc((struct route *)&sc->gif_ro6);
 182                 if (sc->gif_ro6.ro_rt == NULL) {
 183                         m_freem(m);
 184                         return ENETUNREACH;
 185                 }
 186
 187                 /* if it constitutes infinite encapsulation, punt. */
 188                 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
 189                         m_freem(m);
 190                         return ENETUNREACH;     /*XXX*/
 191                 }
 192 #if 0
 193                 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
 194                         - sizeof(struct ip6_hdr);
 195 #endif
 196         }
 197
 198 #if IPV6_MINMTU
 199         /*
 200          * force fragmentation to minimum MTU, to avoid path MTU discovery.
 201          * it is too painful to ask for resend of inner packet, to achieve
 202          * path MTU discovery for encapsulated packets.
 203          */
 204         return(ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, 0));
 205 #else
 206         return(ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, 0));
 207 #endif
 208 }
 209
 210 int in6_gif_input(mp, offp)
 211         struct mbuf **mp;
 212         int *offp;
 213 {
 214         struct mbuf *m = *mp;
 215         struct ifnet *gifp = NULL;
 216         struct ip6_hdr *ip6;
 217         int af = 0;
 218         u_int32_t otos;
 219         u_int8_t proto;
 220
 221         ip6 = mtod(m, struct ip6_hdr *);
 222
 223         gifp = (struct ifnet *)encap_getarg(m);
 224
 225         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 226                 m_freem(m);
 227                 ip6stat.ip6s_nogif++;
 228                 return IPPROTO_DONE;
 229         }
 230
 231         proto = ip6->ip6_nxt;
 232         otos = ip6->ip6_flow;
 233         m_adj(m, *offp);
 234
 235         switch (proto) {
 236 #if INET
 237         case IPPROTO_IPV4:
 238             {
 239                 struct ip *ip;
 240                 u_int8_t otos8;
 241                 af = AF_INET;
 242                 otos8 = (ntohl(otos) >> 20) & 0xff;
 243                 if (m->m_len < sizeof(*ip)) {
 244                         m = m_pullup(m, sizeof(*ip));
 245                         if (!m)
 246                                 return IPPROTO_DONE;
 247                 }
 248                 ip = mtod(m, struct ip *);
 249                 if (gifp->if_flags & IFF_LINK1)
 250                         ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
 251                 else
 252                         ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
 253                 break;
 254             }
 255 #endif /* INET */
 256 #if INET6
 257         case IPPROTO_IPV6:
 258             {
 259                 struct ip6_hdr *ip6;
 260                 af = AF_INET6;
 261                 if (m->m_len < sizeof(*ip6)) {
 262                         m = m_pullup(m, sizeof(*ip6));
 263                         if (!m)
 264                                 return IPPROTO_DONE;
 265                 }
 266                 ip6 = mtod(m, struct ip6_hdr *);
 267                 if (gifp->if_flags & IFF_LINK1)
 268                         ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
 269                 else
 270                         ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
 271                 break;
 272             }
 273 #endif
 274         default:
 275                 ip6stat.ip6s_nogif++;
 276                 m_freem(m);
 277                 return IPPROTO_DONE;
 278         }
 279
 280         dlil_input(gifp, m, m);
 281         return IPPROTO_DONE;
 282 }
 283
 284 /*
 285  * validate outer address.
 286  */
 287 static int
 288 gif_validate6(ip6, sc, ifp)
 289         const struct ip6_hdr *ip6;
 290         struct gif_softc *sc;
 291         struct ifnet *ifp;
 292 {
 293         struct sockaddr_in6 *src, *dst;
 294
 295         src = (struct sockaddr_in6 *)sc->gif_psrc;
 296         dst = (struct sockaddr_in6 *)sc->gif_pdst;
 297
 298         /*
 299          * Check for address match.  Note that the check is for an incoming
 300          * packet.  We should compare the *source* address in our configuration
 301          * and the *destination* address of the packet, and vice versa.
 302          */
 303         if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
 304             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
 305                 return 0;
 306
 307         /* martian filters on outer source - done in ip6_input */
 308
 309         /* ingress filters on outer source */
 310         if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
 311                 struct sockaddr_in6 sin6;
 312                 struct rtentry *rt;
 313
 314                 bzero(&sin6, sizeof(sin6));
 315                 sin6.sin6_family = AF_INET6;
 316                 sin6.sin6_len = sizeof(struct sockaddr_in6);
 317                 sin6.sin6_addr = ip6->ip6_src;
 318 #ifndef SCOPEDROUTING
 319                 sin6.sin6_scope_id = 0; /* XXX */
 320 #endif
 321
 322                 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
 323                 if (!rt || rt->rt_ifp != ifp) {
 324 #if 0
 325                         log(LOG_WARNING, "%s: packet from %s dropped "
 326                             "due to ingress filter\n", if_name(&sc->gif_if),
 327                             ip6_sprintf(&sin6.sin6_addr));
 328 #endif
 329                         if (rt)
 330                                 rtfree(rt);
 331                         return 0;
 332                 }
 333                 rtfree(rt);
 334         }
 335
 336         return 128 * 2;
 337 }
 338
 339 /*
 340  * we know that we are in IFF_UP, outer address available, and outer family
 341  * matched the physical addr family.  see gif_encapcheck().
 342  * sanity check for arg should have been done in the caller.
 343  */
 344 int
 345 gif_encapcheck6(m, off, proto, arg)
 346         const struct mbuf *m;
 347         int off;
 348         int proto;
 349         void *arg;
 350 {
 351         struct ip6_hdr ip6;
 352         struct gif_softc *sc;
 353         struct ifnet *ifp;
 354
 355         /* sanity check done in caller */
 356         sc = (struct gif_softc *)arg;
 357
 358         /* LINTED const cast */
 359         m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
 360         ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
 361
 362         return gif_validate6(&ip6, sc, ifp);
 363 }