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 extern u_long  route_generation;
  71
  72 static __inline__ void*
  73 _cast_non_const(const void * ptr) {
  74         union {
  75                 const void*             cval;
  76                 void*                   val;
  77         } ret;
  78
  79         ret.cval = ptr;
  80         return (ret.val);
  81 }
  82
  83 int
  84 in6_gif_output(
  85         struct ifnet *ifp,
  86         int family, /* family of the packet to be encapsulate. */
  87         struct mbuf *m,
  88         __unused struct rtentry *rt)
  89 {
  90         struct gif_softc *sc = ifnet_softc(ifp);
  91         struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
  92         struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
  93         struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
  94         struct ip6_hdr *ip6;
  95         int proto;
  96         u_int8_t itos, otos;
  97
  98         if (sin6_src == NULL || sin6_dst == NULL ||
  99             sin6_src->sin6_family != AF_INET6 ||
 100             sin6_dst->sin6_family != AF_INET6) {
 101                 m_freem(m);
 102                 return EAFNOSUPPORT;
 103         }
 104
 105         switch (family) {
 106 #if INET
 107         case AF_INET:
 108             {
 109                 struct ip *ip;
 110
 111                 proto = IPPROTO_IPV4;
 112                 if (mbuf_len(m) < sizeof(*ip)) {
 113                         m = m_pullup(m, sizeof(*ip));
 114                         if (!m)
 115                                 return ENOBUFS;
 116                 }
 117                 ip = mtod(m, struct ip *);
 118                 itos = ip->ip_tos;
 119                 break;
 120             }
 121 #endif
 122 #if INET6
 123         case AF_INET6:
 124             {
 125                 proto = IPPROTO_IPV6;
 126                 if (mbuf_len(m) < sizeof(*ip6)) {
 127                         m = m_pullup(m, sizeof(*ip6));
 128                         if (!m)
 129                                 return ENOBUFS;
 130                 }
 131                 ip6 = mtod(m, struct ip6_hdr *);
 132                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 133                 break;
 134             }
 135 #endif
 136         default:
 137 #if DEBUG
 138                 printf("in6_gif_output: warning: unknown family %d passed\n",
 139                         family);
 140 #endif
 141                 m_freem(m);
 142                 return EAFNOSUPPORT;
 143         }
 144
 145         /* prepend new IP header */
 146         M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
 147         if (m && mbuf_len(m) < sizeof(struct ip6_hdr))
 148                 m = m_pullup(m, sizeof(struct ip6_hdr));
 149         if (m == NULL) {
 150                 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
 151                 return ENOBUFS;
 152         }
 153
 154         ip6 = mtod(m, struct ip6_hdr *);
 155         ip6->ip6_flow   = 0;
 156         ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 157         ip6->ip6_vfc    |= IPV6_VERSION;
 158         ip6->ip6_plen   = htons((u_short)m->m_pkthdr.len);
 159         ip6->ip6_nxt    = proto;
 160         ip6->ip6_hlim   = ip6_gif_hlim;
 161         ip6->ip6_src    = sin6_src->sin6_addr;
 162         /* bidirectional configured tunnel mode */
 163         if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
 164                 ip6->ip6_dst = sin6_dst->sin6_addr;
 165         else  {
 166                 m_freem(m);
 167                 return ENETUNREACH;
 168         }
 169         if (ifp->if_flags & IFF_LINK1)
 170                 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
 171         else
 172                 ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
 173         ip6->ip6_flow &= ~ntohl(0xff00000);
 174         ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
 175
 176         if (dst->sin6_family != sin6_dst->sin6_family ||
 177             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr) ||
 178             (sc->gif_ro6.ro_rt != NULL &&
 179             (sc->gif_ro6.ro_rt->generation_id != route_generation ||
 180             sc->gif_ro6.ro_rt->rt_ifp == ifp))) {
 181                 /* cache route doesn't match */
 182                 bzero(dst, sizeof(*dst));
 183                 dst->sin6_family = sin6_dst->sin6_family;
 184                 dst->sin6_len = sizeof(struct sockaddr_in6);
 185                 dst->sin6_addr = sin6_dst->sin6_addr;
 186                 if (sc->gif_ro6.ro_rt) {
 187                         rtfree(sc->gif_ro6.ro_rt);
 188                         sc->gif_ro6.ro_rt = NULL;
 189                 }
 190 #if 0
 191                 sc->gif_if.if_mtu = GIF_MTU;
 192 #endif
 193         }
 194
 195         if (sc->gif_ro6.ro_rt == NULL) {
 196                 rtalloc((struct route *)&sc->gif_ro6);
 197                 if (sc->gif_ro6.ro_rt == NULL) {
 198                         m_freem(m);
 199                         return ENETUNREACH;
 200                 }
 201
 202                 /* if it constitutes infinite encapsulation, punt. */
 203                 if (sc->gif_ro6.ro_rt->rt_ifp == ifp) {
 204                         m_freem(m);
 205                         return ENETUNREACH;     /*XXX*/
 206                 }
 207 #if 0
 208                 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
 209                         - sizeof(struct ip6_hdr);
 210 #endif
 211         }
 212
 213 #if IPV6_MINMTU
 214         /*
 215          * force fragmentation to minimum MTU, to avoid path MTU discovery.
 216          * it is too painful to ask for resend of inner packet, to achieve
 217          * path MTU discovery for encapsulated packets.
 218          */
 219         return(ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, 0));
 220 #else
 221         return(ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, 0));
 222 #endif
 223 }
 224
 225 int in6_gif_input(mp, offp)
 226         struct mbuf **mp;
 227         int *offp;
 228 {
 229         struct mbuf *m = *mp;
 230         struct ifnet *gifp = NULL;
 231         struct ip6_hdr *ip6;
 232         int af = 0;
 233         u_int32_t otos;
 234         u_int8_t proto;
 235
 236         ip6 = mtod(m, struct ip6_hdr *);
 237
 238         gifp = ((struct gif_softc*)encap_getarg(m))->gif_if;
 239
 240         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 241                 m_freem(m);
 242                 ip6stat.ip6s_nogif++;
 243                 return IPPROTO_DONE;
 244         }
 245
 246         proto = ip6->ip6_nxt;
 247         otos = ip6->ip6_flow;
 248         m_adj(m, *offp);
 249
 250         switch (proto) {
 251 #if INET
 252         case IPPROTO_IPV4:
 253             {
 254                 struct ip *ip;
 255                 u_int8_t otos8;
 256                 af = AF_INET;
 257                 otos8 = (ntohl(otos) >> 20) & 0xff;
 258                 if (mbuf_len(m) < sizeof(*ip)) {
 259                         m = m_pullup(m, sizeof(*ip));
 260                         if (!m)
 261                                 return IPPROTO_DONE;
 262                 }
 263                 ip = mtod(m, struct ip *);
 264                 if (gifp->if_flags & IFF_LINK1)
 265                         ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
 266                 else
 267                         ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
 268                 break;
 269             }
 270 #endif /* INET */
 271 #if INET6
 272         case IPPROTO_IPV6:
 273             {
 274                 af = AF_INET6;
 275                 if (mbuf_len(m) < sizeof(*ip6)) {
 276                         m = m_pullup(m, sizeof(*ip6));
 277                         if (!m)
 278                                 return IPPROTO_DONE;
 279                 }
 280                 ip6 = mtod(m, struct ip6_hdr *);
 281                 if (gifp->if_flags & IFF_LINK1)
 282                         ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
 283                 else
 284                         ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
 285                 break;
 286             }
 287 #endif
 288         default:
 289                 ip6stat.ip6s_nogif++;
 290                 m_freem(m);
 291                 return IPPROTO_DONE;
 292         }
 293
 294         if (m->m_pkthdr.rcvif)  /* replace the rcvif by gifp for ifnet_input to route it correctly */
 295                 m->m_pkthdr.rcvif = gifp;
 296
 297         ifnet_input(gifp, m, NULL);
 298         return IPPROTO_DONE;
 299 }
 300
 301 /*
 302  * validate outer address.
 303  */
 304 static int
 305 gif_validate6(
 306         const struct ip6_hdr *ip6,
 307         struct gif_softc *sc,
 308         struct ifnet *ifp)
 309 {
 310         struct sockaddr_in6 *src, *dst;
 311
 312         src = (struct sockaddr_in6 *)sc->gif_psrc;
 313         dst = (struct sockaddr_in6 *)sc->gif_pdst;
 314
 315         /*
 316          * Check for address match.  Note that the check is for an incoming
 317          * packet.  We should compare the *source* address in our configuration
 318          * and the *destination* address of the packet, and vice versa.
 319          */
 320         if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
 321             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
 322                 return 0;
 323
 324         /* martian filters on outer source - done in ip6_input */
 325
 326         /* ingress filters on outer source */
 327         if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 && ifp) {
 328                 struct sockaddr_in6 sin6;
 329                 struct rtentry *rt;
 330
 331                 bzero(&sin6, sizeof(sin6));
 332                 sin6.sin6_family = AF_INET6;
 333                 sin6.sin6_len = sizeof(struct sockaddr_in6);
 334                 sin6.sin6_addr = ip6->ip6_src;
 335 #ifndef SCOPEDROUTING
 336                 sin6.sin6_scope_id = 0; /* XXX */
 337 #endif
 338
 339                 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
 340                 if (!rt || rt->rt_ifp != ifp) {
 341 #if 0
 342                         log(LOG_WARNING, "%s: packet from %s dropped "
 343                             "due to ingress filter\n", if_name(&sc->gif_if),
 344                             ip6_sprintf(&sin6.sin6_addr));
 345 #endif
 346                         if (rt)
 347                                 rtfree(rt);
 348                         return 0;
 349                 }
 350                 rtfree(rt);
 351         }
 352
 353         return 128 * 2;
 354 }
 355
 356 /*
 357  * we know that we are in IFF_UP, outer address available, and outer family
 358  * matched the physical addr family.  see gif_encapcheck().
 359  * sanity check for arg should have been done in the caller.
 360  */
 361 int
 362 gif_encapcheck6(
 363         const struct mbuf *m,
 364         __unused int off,
 365         __unused int proto,
 366         void *arg)
 367 {
 368         struct ip6_hdr ip6;
 369         struct gif_softc *sc;
 370         struct ifnet *ifp;
 371
 372         /* sanity check done in caller */
 373         sc = (struct gif_softc *)arg;
 374
 375         mbuf_copydata(m, 0, sizeof(ip6), &ip6);
 376         ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
 377
 378         return gif_validate6(&ip6, sc, ifp);
 379 }