bsd/netinet6/in6_gif.c

   1 /*
   2  * Copyright (c) 2009-2016 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /* $FreeBSD: src/sys/netinet6/in6_gif.c,v 1.2.2.3 2001/07/03 11:01:52 ume Exp $ */
  30 /* $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ */
  31
  32 /*
  33  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  34  * All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. Neither the name of the project nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  */
  60
  61
  62 #include <sys/param.h>
  63 #include <sys/systm.h>
  64 #include <sys/socket.h>
  65 #include <sys/sockio.h>
  66 #include <sys/mbuf.h>
  67 #include <sys/errno.h>
  68 #include <sys/queue.h>
  69 #include <sys/syslog.h>
  70
  71 #include <sys/malloc.h>
  72 #include <sys/protosw.h>
  73
  74 #include <net/if.h>
  75 #include <net/route.h>
  76
  77 #include <netinet/in.h>
  78 #include <netinet/in_systm.h>
  79 #if INET
  80 #include <netinet/ip.h>
  81 #endif
  82 #include <netinet/ip_encap.h>
  83 #if INET6
  84 #include <netinet/ip6.h>
  85 #include <netinet6/ip6_var.h>
  86 #include <netinet6/in6_gif.h>
  87 #include <netinet6/in6_var.h>
  88 #endif
  89 #include <netinet/ip_ecn.h>
  90 #if INET6
  91 #include <netinet6/ip6_ecn.h>
  92 #endif
  93
  94 #include <net/if_gif.h>
  95
  96 #include <net/net_osdep.h>
  97
  98 int
  99 in6_gif_output(
 100         struct ifnet *ifp,
 101         int family, /* family of the packet to be encapsulate. */
 102         struct mbuf *m,
 103         __unused struct rtentry *rt)
 104 {
 105         struct gif_softc *sc = ifnet_softc(ifp);
 106         struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
 107         struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)
 108             (void *)sc->gif_psrc;
 109         struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)
 110             (void *)sc->gif_pdst;
 111         struct ip6_hdr *ip6;
 112         int proto;
 113         u_int8_t itos, otos;
 114
 115         GIF_LOCK_ASSERT(sc);
 116
 117         if (sin6_src == NULL || sin6_dst == NULL ||
 118             sin6_src->sin6_family != AF_INET6 ||
 119             sin6_dst->sin6_family != AF_INET6) {
 120                 m_freem(m);
 121                 return (EAFNOSUPPORT);
 122         }
 123
 124         switch (family) {
 125 #if INET
 126         case AF_INET:
 127             {
 128                 struct ip *ip;
 129
 130                 proto = IPPROTO_IPV4;
 131                 if (mbuf_len(m) < sizeof (*ip)) {
 132                         m = m_pullup(m, sizeof (*ip));
 133                         if (!m)
 134                                 return (ENOBUFS);
 135                 }
 136                 ip = mtod(m, struct ip *);
 137                 itos = ip->ip_tos;
 138                 break;
 139             }
 140 #endif
 141 #if INET6
 142         case AF_INET6:
 143             {
 144                 proto = IPPROTO_IPV6;
 145                 if (mbuf_len(m) < sizeof (*ip6)) {
 146                         m = m_pullup(m, sizeof (*ip6));
 147                         if (!m)
 148                                 return (ENOBUFS);
 149                 }
 150                 ip6 = mtod(m, struct ip6_hdr *);
 151                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 152                 break;
 153             }
 154 #endif
 155         default:
 156 #if DEBUG
 157                 printf("in6_gif_output: warning: unknown family %d passed\n",
 158                         family);
 159 #endif
 160                 m_freem(m);
 161                 return (EAFNOSUPPORT);
 162         }
 163
 164         /* prepend new IP header */
 165         M_PREPEND(m, sizeof (struct ip6_hdr), M_DONTWAIT, 1);
 166         if (m && mbuf_len(m) < sizeof (struct ip6_hdr))
 167                 m = m_pullup(m, sizeof (struct ip6_hdr));
 168         if (m == NULL) {
 169                 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
 170                 return (ENOBUFS);
 171         }
 172
 173         ip6 = mtod(m, struct ip6_hdr *);
 174         ip6->ip6_flow   = 0;
 175         ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 176         ip6->ip6_vfc    |= IPV6_VERSION;
 177         ip6->ip6_plen   = htons((u_short)m->m_pkthdr.len);
 178         ip6->ip6_nxt    = proto;
 179         ip6->ip6_hlim   = ip6_gif_hlim;
 180         ip6->ip6_src    = sin6_src->sin6_addr;
 181         /* bidirectional configured tunnel mode */
 182         if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
 183                 ip6->ip6_dst = sin6_dst->sin6_addr;
 184         else  {
 185                 m_freem(m);
 186                 return (ENETUNREACH);
 187         }
 188         ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_NORMAL : ECN_NOCARE,
 189             &otos, &itos);
 190         ip6->ip6_flow &= ~htonl(0xff << 20);
 191         ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
 192
 193         if (ROUTE_UNUSABLE(&sc->gif_ro6) ||
 194             dst->sin6_family != sin6_dst->sin6_family ||
 195             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr) ||
 196             (sc->gif_ro6.ro_rt != NULL && sc->gif_ro6.ro_rt->rt_ifp == ifp)) {
 197                 /* cache route doesn't match or recursive route */
 198                 bzero(dst, sizeof (*dst));
 199                 dst->sin6_family = sin6_dst->sin6_family;
 200                 dst->sin6_len = sizeof (struct sockaddr_in6);
 201                 dst->sin6_addr = sin6_dst->sin6_addr;
 202                 ROUTE_RELEASE(&sc->gif_ro6);
 203 #if 0
 204                 sc->gif_if.if_mtu = GIF_MTU;
 205 #endif
 206         }
 207
 208         if (sc->gif_ro6.ro_rt == NULL) {
 209                 rtalloc((struct route *)&sc->gif_ro6);
 210                 if (sc->gif_ro6.ro_rt == NULL) {
 211                         m_freem(m);
 212                         return (ENETUNREACH);
 213                 }
 214                 RT_LOCK(sc->gif_ro6.ro_rt);
 215                 /* if it constitutes infinite encapsulation, punt. */
 216                 if (sc->gif_ro6.ro_rt->rt_ifp == ifp) {
 217                         RT_UNLOCK(sc->gif_ro6.ro_rt);
 218                         m_freem(m);
 219                         return (ENETUNREACH); /* XXX */
 220                 }
 221 #if 0
 222                 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
 223                         - sizeof (struct ip6_hdr);
 224 #endif
 225                 RT_UNLOCK(sc->gif_ro6.ro_rt);
 226         }
 227
 228 #if IPV6_MINMTU
 229         /*
 230          * force fragmentation to minimum MTU, to avoid path MTU discovery.
 231          * it is too painful to ask for resend of inner packet, to achieve
 232          * path MTU discovery for encapsulated packets.
 233          */
 234         return (ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL));
 235 #else
 236         return (ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL));
 237 #endif
 238 }
 239
 240 int
 241 in6_gif_input(struct mbuf **mp, int *offp, int proto)
 242 {
 243         struct mbuf *m = *mp;
 244         struct ifnet *gifp = NULL;
 245         struct ip6_hdr *ip6;
 246         int af = 0;
 247         u_int32_t otos;
 248         int egress_success = 0;
 249
 250         ip6 = mtod(m, struct ip6_hdr *);
 251
 252         gifp = ((struct gif_softc *)encap_getarg(m))->gif_if;
 253
 254         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 255                 m_freem(m);
 256                 ip6stat.ip6s_nogif++;
 257                 return (IPPROTO_DONE);
 258         }
 259
 260         otos = ip6->ip6_flow;
 261         m_adj(m, *offp);
 262
 263         switch (proto) {
 264 #if INET
 265         case IPPROTO_IPV4:
 266             {
 267                 struct ip *ip;
 268                 u_int8_t otos8, old_tos;
 269                 int sum;
 270
 271                 af = AF_INET;
 272                 otos8 = (ntohl(otos) >> 20) & 0xff;
 273                 if (mbuf_len(m) < sizeof (*ip)) {
 274                         m = m_pullup(m, sizeof (*ip));
 275                         if (!m)
 276                                 return (IPPROTO_DONE);
 277                 }
 278                 ip = mtod(m, struct ip *);
 279                 if (gifp->if_flags & IFF_LINK1) {
 280                         old_tos = ip->ip_tos;
 281                         egress_success = ip_ecn_egress(ECN_NORMAL, &otos8, &ip->ip_tos);
 282                         if (old_tos != ip->ip_tos) {
 283                             sum = ~ntohs(ip->ip_sum) & 0xffff;
 284                             sum += (~old_tos & 0xffff) + ip->ip_tos;
 285                             sum = (sum >> 16) + (sum & 0xffff);
 286                             sum += (sum >> 16);  /* add carry */
 287                             ip->ip_sum = htons(~sum & 0xffff);
 288                         }
 289                 } else
 290                         egress_success = ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
 291                 break;
 292             }
 293 #endif /* INET */
 294 #if INET6
 295         case IPPROTO_IPV6:
 296             {
 297                 af = AF_INET6;
 298                 if (mbuf_len(m) < sizeof (*ip6)) {
 299                         m = m_pullup(m, sizeof (*ip6));
 300                         if (!m)
 301                                 return (IPPROTO_DONE);
 302                 }
 303                 ip6 = mtod(m, struct ip6_hdr *);
 304                 if (gifp->if_flags & IFF_LINK1)
 305                         egress_success = ip6_ecn_egress(ECN_NORMAL, &otos, &ip6->ip6_flow);
 306                 else
 307                         egress_success = ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
 308                 break;
 309             }
 310 #endif
 311         default:
 312                 ip6stat.ip6s_nogif++;
 313                 m_freem(m);
 314                 return (IPPROTO_DONE);
 315         }
 316
 317         if (egress_success == 0) {
 318                 ip6stat.ip6s_nogif++;
 319                 m_freem(m);
 320                 return (IPPROTO_DONE);
 321         }
 322
 323         /* Replace the rcvif by gifp for ifnet_input to route it correctly */
 324         if (m->m_pkthdr.rcvif)
 325                 m->m_pkthdr.rcvif = gifp;
 326
 327         ifnet_input(gifp, m, NULL);
 328         return (IPPROTO_DONE);
 329 }
 330
 331 /*
 332  * validate outer address.
 333  */
 334 static int
 335 gif_validate6(
 336         const struct ip6_hdr *ip6,
 337         struct gif_softc *sc,
 338         struct ifnet *ifp)
 339 {
 340         struct sockaddr_in6 *src, *dst;
 341
 342         src = (struct sockaddr_in6 *)(void *)sc->gif_psrc;
 343         dst = (struct sockaddr_in6 *)(void *)sc->gif_pdst;
 344
 345         /*
 346          * Check for address match.  Note that the check is for an incoming
 347          * packet.  We should compare the *source* address in our configuration
 348          * and the *destination* address of the packet, and vice versa.
 349          */
 350         if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
 351             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
 352                 return (0);
 353
 354         /* martian filters on outer source - done in ip6_input */
 355
 356         /* ingress filters on outer source */
 357         if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 && ifp) {
 358                 struct sockaddr_in6 sin6;
 359                 struct rtentry *rt;
 360
 361                 bzero(&sin6, sizeof (sin6));
 362                 sin6.sin6_family = AF_INET6;
 363                 sin6.sin6_len = sizeof (struct sockaddr_in6);
 364                 sin6.sin6_addr = ip6->ip6_src;
 365
 366                 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0);
 367                 if (rt != NULL)
 368                         RT_LOCK(rt);
 369                 if (!rt || rt->rt_ifp != ifp) {
 370 #if 0
 371                         log(LOG_WARNING, "%s: packet from %s dropped "
 372                             "due to ingress filter\n", if_name(&sc->gif_if),
 373                             ip6_sprintf(&sin6.sin6_addr));
 374 #endif
 375                         if (rt != NULL) {
 376                                 RT_UNLOCK(rt);
 377                                 rtfree(rt);
 378                         }
 379                         return (0);
 380                 }
 381                 RT_UNLOCK(rt);
 382                 rtfree(rt);
 383         }
 384
 385         return (128 * 2);
 386 }
 387
 388 /*
 389  * we know that we are in IFF_UP, outer address available, and outer family
 390  * matched the physical addr family.  see gif_encapcheck().
 391  * sanity check for arg should have been done in the caller.
 392  */
 393 int
 394 gif_encapcheck6(
 395         const struct mbuf *m,
 396         __unused int off,
 397         __unused int proto,
 398         void *arg)
 399 {
 400         struct ip6_hdr ip6;
 401         struct gif_softc *sc;
 402         struct ifnet *ifp;
 403
 404         /* sanity check done in caller */
 405         sc = (struct gif_softc *)arg;
 406
 407         GIF_LOCK_ASSERT(sc);
 408
 409         mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof (ip6), &ip6);
 410         ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
 411
 412         return (gif_validate6(&ip6, sc, ifp));
 413 }