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 #include <netinet/ip6.h>
  84 #include <netinet6/ip6_var.h>
  85 #include <netinet6/in6_gif.h>
  86 #include <netinet6/in6_var.h>
  87 #include <netinet/ip_ecn.h>
  88 #include <netinet6/ip6_ecn.h>
  89
  90 #include <net/if_gif.h>
  91
  92 #include <net/net_osdep.h>
  93
  94 int
  95 in6_gif_output(
  96         struct ifnet *ifp,
  97         int family, /* family of the packet to be encapsulate. */
  98         struct mbuf *m,
  99         __unused struct rtentry *rt)
 100 {
 101         struct gif_softc *sc = ifnet_softc(ifp);
 102         struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
 103         struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)
 104             (void *)sc->gif_psrc;
 105         struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)
 106             (void *)sc->gif_pdst;
 107         struct ip6_hdr *ip6;
 108         int proto;
 109         u_int8_t itos, otos;
 110
 111         GIF_LOCK_ASSERT(sc);
 112
 113         if (sin6_src == NULL || sin6_dst == NULL ||
 114             sin6_src->sin6_family != AF_INET6 ||
 115             sin6_dst->sin6_family != AF_INET6) {
 116                 m_freem(m);
 117                 return EAFNOSUPPORT;
 118         }
 119
 120         switch (family) {
 121 #if INET
 122         case AF_INET:
 123         {
 124                 struct ip *ip;
 125
 126                 proto = IPPROTO_IPV4;
 127                 if (mbuf_len(m) < sizeof(*ip)) {
 128                         m = m_pullup(m, sizeof(*ip));
 129                         if (!m) {
 130                                 return ENOBUFS;
 131                         }
 132                 }
 133                 ip = mtod(m, struct ip *);
 134                 itos = ip->ip_tos;
 135                 break;
 136         }
 137 #endif
 138         case AF_INET6:
 139         {
 140                 proto = IPPROTO_IPV6;
 141                 if (mbuf_len(m) < sizeof(*ip6)) {
 142                         m = m_pullup(m, sizeof(*ip6));
 143                         if (!m) {
 144                                 return ENOBUFS;
 145                         }
 146                 }
 147                 ip6 = mtod(m, struct ip6_hdr *);
 148                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 149                 break;
 150         }
 151         default:
 152 #if DEBUG
 153                 printf("in6_gif_output: warning: unknown family %d passed\n",
 154                     family);
 155 #endif
 156                 m_freem(m);
 157                 return EAFNOSUPPORT;
 158         }
 159
 160         /* prepend new IP header */
 161         M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT, 1);
 162         if (m && mbuf_len(m) < sizeof(struct ip6_hdr)) {
 163                 m = m_pullup(m, sizeof(struct ip6_hdr));
 164         }
 165         if (m == NULL) {
 166                 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
 167                 return ENOBUFS;
 168         }
 169
 170         ip6 = mtod(m, struct ip6_hdr *);
 171         ip6->ip6_flow   = 0;
 172         ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 173         ip6->ip6_vfc    |= IPV6_VERSION;
 174         ip6->ip6_plen   = htons((u_short)m->m_pkthdr.len);
 175         ip6->ip6_nxt    = proto;
 176         ip6->ip6_hlim   = ip6_gif_hlim;
 177         ip6->ip6_src    = sin6_src->sin6_addr;
 178         /* bidirectional configured tunnel mode */
 179         if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) {
 180                 ip6->ip6_dst = sin6_dst->sin6_addr;
 181         } else {
 182                 m_freem(m);
 183                 return ENETUNREACH;
 184         }
 185         ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_NORMAL : ECN_NOCARE,
 186             &otos, &itos);
 187         ip6->ip6_flow &= ~htonl(0xff << 20);
 188         ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
 189
 190         if (ROUTE_UNUSABLE(&sc->gif_ro6) ||
 191             dst->sin6_family != sin6_dst->sin6_family ||
 192             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr) ||
 193             (sc->gif_ro6.ro_rt != NULL && sc->gif_ro6.ro_rt->rt_ifp == ifp)) {
 194                 /* cache route doesn't match or recursive route */
 195                 bzero(dst, sizeof(*dst));
 196                 dst->sin6_family = sin6_dst->sin6_family;
 197                 dst->sin6_len = sizeof(struct sockaddr_in6);
 198                 dst->sin6_addr = sin6_dst->sin6_addr;
 199                 ROUTE_RELEASE(&sc->gif_ro6);
 200 #if 0
 201                 sc->gif_if.if_mtu = GIF_MTU;
 202 #endif
 203         }
 204
 205         if (sc->gif_ro6.ro_rt == NULL) {
 206                 rtalloc((struct route *)&sc->gif_ro6);
 207                 if (sc->gif_ro6.ro_rt == NULL) {
 208                         m_freem(m);
 209                         return ENETUNREACH;
 210                 }
 211                 RT_LOCK(sc->gif_ro6.ro_rt);
 212                 /* if it constitutes infinite encapsulation, punt. */
 213                 if (sc->gif_ro6.ro_rt->rt_ifp == ifp) {
 214                         RT_UNLOCK(sc->gif_ro6.ro_rt);
 215                         m_freem(m);
 216                         return ENETUNREACH; /* XXX */
 217                 }
 218 #if 0
 219                 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
 220                     - sizeof(struct ip6_hdr);
 221 #endif
 222                 RT_UNLOCK(sc->gif_ro6.ro_rt);
 223         }
 224
 225 #if IPV6_MINMTU
 226         /*
 227          * force fragmentation to minimum MTU, to avoid path MTU discovery.
 228          * it is too painful to ask for resend of inner packet, to achieve
 229          * path MTU discovery for encapsulated packets.
 230          */
 231         return ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
 232 #else
 233         return ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
 234 #endif
 235 }
 236
 237 int
 238 in6_gif_input(struct mbuf **mp, int *offp, int proto)
 239 {
 240         struct mbuf *m = *mp;
 241         struct ifnet *gifp = NULL;
 242         struct ip6_hdr *ip6;
 243         int af = 0;
 244         u_int32_t otos;
 245         int egress_success = 0;
 246
 247         ip6 = mtod(m, struct ip6_hdr *);
 248
 249         gifp = ((struct gif_softc *)encap_getarg(m))->gif_if;
 250
 251         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 252                 m_freem(m);
 253                 ip6stat.ip6s_nogif++;
 254                 return IPPROTO_DONE;
 255         }
 256
 257         otos = ip6->ip6_flow;
 258         m_adj(m, *offp);
 259
 260         switch (proto) {
 261         case IPPROTO_IPV4:
 262         {
 263                 struct ip *ip;
 264                 u_int8_t otos8, old_tos;
 265                 int sum;
 266
 267                 af = AF_INET;
 268                 otos8 = (ntohl(otos) >> 20) & 0xff;
 269                 if (mbuf_len(m) < sizeof(*ip)) {
 270                         m = m_pullup(m, sizeof(*ip));
 271                         if (!m) {
 272                                 return IPPROTO_DONE;
 273                         }
 274                 }
 275                 ip = mtod(m, struct ip *);
 276                 if (gifp->if_flags & IFF_LINK1) {
 277                         old_tos = ip->ip_tos;
 278                         egress_success = ip_ecn_egress(ECN_NORMAL, &otos8, &ip->ip_tos);
 279                         if (old_tos != ip->ip_tos) {
 280                                 sum = ~ntohs(ip->ip_sum) & 0xffff;
 281                                 sum += (~old_tos & 0xffff) + ip->ip_tos;
 282                                 sum = (sum >> 16) + (sum & 0xffff);
 283                                 sum += (sum >> 16); /* add carry */
 284                                 ip->ip_sum = htons(~sum & 0xffff);
 285                         }
 286                 } else {
 287                         egress_success = ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
 288                 }
 289                 break;
 290         }
 291         case IPPROTO_IPV6:
 292         {
 293                 af = AF_INET6;
 294                 if (mbuf_len(m) < sizeof(*ip6)) {
 295                         m = m_pullup(m, sizeof(*ip6));
 296                         if (!m) {
 297                                 return IPPROTO_DONE;
 298                         }
 299                 }
 300                 ip6 = mtod(m, struct ip6_hdr *);
 301                 if (gifp->if_flags & IFF_LINK1) {
 302                         egress_success = ip6_ecn_egress(ECN_NORMAL, &otos, &ip6->ip6_flow);
 303                 } else {
 304                         egress_success = ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
 305                 }
 306                 break;
 307         }
 308         default:
 309                 ip6stat.ip6s_nogif++;
 310                 m_freem(m);
 311                 return IPPROTO_DONE;
 312         }
 313
 314         if (egress_success == 0) {
 315                 ip6stat.ip6s_nogif++;
 316                 m_freem(m);
 317                 return IPPROTO_DONE;
 318         }
 319
 320         /* Replace the rcvif by gifp for ifnet_input to route it correctly */
 321         if (m->m_pkthdr.rcvif) {
 322                 m->m_pkthdr.rcvif = gifp;
 323         }
 324
 325         ifnet_input(gifp, m, NULL);
 326         return IPPROTO_DONE;
 327 }
 328
 329 /*
 330  * validate outer address.
 331  */
 332 static int
 333 gif_validate6(
 334         const struct ip6_hdr *ip6,
 335         struct gif_softc *sc,
 336         struct ifnet *ifp)
 337 {
 338         struct sockaddr_in6 *src, *dst;
 339
 340         src = (struct sockaddr_in6 *)(void *)sc->gif_psrc;
 341         dst = (struct sockaddr_in6 *)(void *)sc->gif_pdst;
 342
 343         /*
 344          * Check for address match.  Note that the check is for an incoming
 345          * packet.  We should compare the *source* address in our configuration
 346          * and the *destination* address of the packet, and vice versa.
 347          */
 348         if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
 349             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) {
 350                 return 0;
 351         }
 352
 353         /* martian filters on outer source - done in ip6_input */
 354
 355         /* ingress filters on outer source */
 356         if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 && ifp) {
 357                 struct sockaddr_in6 sin6;
 358                 struct rtentry *rt;
 359
 360                 bzero(&sin6, sizeof(sin6));
 361                 sin6.sin6_family = AF_INET6;
 362                 sin6.sin6_len = sizeof(struct sockaddr_in6);
 363                 sin6.sin6_addr = ip6->ip6_src;
 364
 365                 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0);
 366                 if (rt != NULL) {
 367                         RT_LOCK(rt);
 368                 }
 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 }