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                 }
 137                 ip = mtod(m, struct ip *);
 138                 itos = ip->ip_tos;
 139                 break;
 140         }
 141 #endif
 142 #if INET6
 143         case AF_INET6:
 144         {
 145                 proto = IPPROTO_IPV6;
 146                 if (mbuf_len(m) < sizeof(*ip6)) {
 147                         m = m_pullup(m, sizeof(*ip6));
 148                         if (!m) {
 149                                 return ENOBUFS;
 150                         }
 151                 }
 152                 ip6 = mtod(m, struct ip6_hdr *);
 153                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 154                 break;
 155         }
 156 #endif
 157         default:
 158 #if DEBUG
 159                 printf("in6_gif_output: warning: unknown family %d passed\n",
 160                     family);
 161 #endif
 162                 m_freem(m);
 163                 return EAFNOSUPPORT;
 164         }
 165
 166         /* prepend new IP header */
 167         M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT, 1);
 168         if (m && mbuf_len(m) < sizeof(struct ip6_hdr)) {
 169                 m = m_pullup(m, sizeof(struct ip6_hdr));
 170         }
 171         if (m == NULL) {
 172                 printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
 173                 return ENOBUFS;
 174         }
 175
 176         ip6 = mtod(m, struct ip6_hdr *);
 177         ip6->ip6_flow   = 0;
 178         ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 179         ip6->ip6_vfc    |= IPV6_VERSION;
 180         ip6->ip6_plen   = htons((u_short)m->m_pkthdr.len);
 181         ip6->ip6_nxt    = proto;
 182         ip6->ip6_hlim   = ip6_gif_hlim;
 183         ip6->ip6_src    = sin6_src->sin6_addr;
 184         /* bidirectional configured tunnel mode */
 185         if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) {
 186                 ip6->ip6_dst = sin6_dst->sin6_addr;
 187         } else {
 188                 m_freem(m);
 189                 return ENETUNREACH;
 190         }
 191         ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_NORMAL : ECN_NOCARE,
 192             &otos, &itos);
 193         ip6->ip6_flow &= ~htonl(0xff << 20);
 194         ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
 195
 196         if (ROUTE_UNUSABLE(&sc->gif_ro6) ||
 197             dst->sin6_family != sin6_dst->sin6_family ||
 198             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr) ||
 199             (sc->gif_ro6.ro_rt != NULL && sc->gif_ro6.ro_rt->rt_ifp == ifp)) {
 200                 /* cache route doesn't match or recursive route */
 201                 bzero(dst, sizeof(*dst));
 202                 dst->sin6_family = sin6_dst->sin6_family;
 203                 dst->sin6_len = sizeof(struct sockaddr_in6);
 204                 dst->sin6_addr = sin6_dst->sin6_addr;
 205                 ROUTE_RELEASE(&sc->gif_ro6);
 206 #if 0
 207                 sc->gif_if.if_mtu = GIF_MTU;
 208 #endif
 209         }
 210
 211         if (sc->gif_ro6.ro_rt == NULL) {
 212                 rtalloc((struct route *)&sc->gif_ro6);
 213                 if (sc->gif_ro6.ro_rt == NULL) {
 214                         m_freem(m);
 215                         return ENETUNREACH;
 216                 }
 217                 RT_LOCK(sc->gif_ro6.ro_rt);
 218                 /* if it constitutes infinite encapsulation, punt. */
 219                 if (sc->gif_ro6.ro_rt->rt_ifp == ifp) {
 220                         RT_UNLOCK(sc->gif_ro6.ro_rt);
 221                         m_freem(m);
 222                         return ENETUNREACH; /* XXX */
 223                 }
 224 #if 0
 225                 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
 226                     - sizeof(struct ip6_hdr);
 227 #endif
 228                 RT_UNLOCK(sc->gif_ro6.ro_rt);
 229         }
 230
 231 #if IPV6_MINMTU
 232         /*
 233          * force fragmentation to minimum MTU, to avoid path MTU discovery.
 234          * it is too painful to ask for resend of inner packet, to achieve
 235          * path MTU discovery for encapsulated packets.
 236          */
 237         return ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
 238 #else
 239         return ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
 240 #endif
 241 }
 242
 243 int
 244 in6_gif_input(struct mbuf **mp, int *offp, int proto)
 245 {
 246         struct mbuf *m = *mp;
 247         struct ifnet *gifp = NULL;
 248         struct ip6_hdr *ip6;
 249         int af = 0;
 250         u_int32_t otos;
 251         int egress_success = 0;
 252
 253         ip6 = mtod(m, struct ip6_hdr *);
 254
 255         gifp = ((struct gif_softc *)encap_getarg(m))->gif_if;
 256
 257         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 258                 m_freem(m);
 259                 ip6stat.ip6s_nogif++;
 260                 return IPPROTO_DONE;
 261         }
 262
 263         otos = ip6->ip6_flow;
 264         m_adj(m, *offp);
 265
 266         switch (proto) {
 267 #if INET
 268         case IPPROTO_IPV4:
 269         {
 270                 struct ip *ip;
 271                 u_int8_t otos8, old_tos;
 272                 int sum;
 273
 274                 af = AF_INET;
 275                 otos8 = (ntohl(otos) >> 20) & 0xff;
 276                 if (mbuf_len(m) < sizeof(*ip)) {
 277                         m = m_pullup(m, sizeof(*ip));
 278                         if (!m) {
 279                                 return IPPROTO_DONE;
 280                         }
 281                 }
 282                 ip = mtod(m, struct ip *);
 283                 if (gifp->if_flags & IFF_LINK1) {
 284                         old_tos = ip->ip_tos;
 285                         egress_success = ip_ecn_egress(ECN_NORMAL, &otos8, &ip->ip_tos);
 286                         if (old_tos != ip->ip_tos) {
 287                                 sum = ~ntohs(ip->ip_sum) & 0xffff;
 288                                 sum += (~old_tos & 0xffff) + ip->ip_tos;
 289                                 sum = (sum >> 16) + (sum & 0xffff);
 290                                 sum += (sum >> 16); /* add carry */
 291                                 ip->ip_sum = htons(~sum & 0xffff);
 292                         }
 293                 } else {
 294                         egress_success = ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
 295                 }
 296                 break;
 297         }
 298 #endif /* INET */
 299 #if INET6
 300         case IPPROTO_IPV6:
 301         {
 302                 af = AF_INET6;
 303                 if (mbuf_len(m) < sizeof(*ip6)) {
 304                         m = m_pullup(m, sizeof(*ip6));
 305                         if (!m) {
 306                                 return IPPROTO_DONE;
 307                         }
 308                 }
 309                 ip6 = mtod(m, struct ip6_hdr *);
 310                 if (gifp->if_flags & IFF_LINK1) {
 311                         egress_success = ip6_ecn_egress(ECN_NORMAL, &otos, &ip6->ip6_flow);
 312                 } else {
 313                         egress_success = ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
 314                 }
 315                 break;
 316         }
 317 #endif
 318         default:
 319                 ip6stat.ip6s_nogif++;
 320                 m_freem(m);
 321                 return IPPROTO_DONE;
 322         }
 323
 324         if (egress_success == 0) {
 325                 ip6stat.ip6s_nogif++;
 326                 m_freem(m);
 327                 return IPPROTO_DONE;
 328         }
 329
 330         /* Replace the rcvif by gifp for ifnet_input to route it correctly */
 331         if (m->m_pkthdr.rcvif) {
 332                 m->m_pkthdr.rcvif = gifp;
 333         }
 334
 335         ifnet_input(gifp, m, NULL);
 336         return IPPROTO_DONE;
 337 }
 338
 339 /*
 340  * validate outer address.
 341  */
 342 static int
 343 gif_validate6(
 344         const struct ip6_hdr *ip6,
 345         struct gif_softc *sc,
 346         struct ifnet *ifp)
 347 {
 348         struct sockaddr_in6 *src, *dst;
 349
 350         src = (struct sockaddr_in6 *)(void *)sc->gif_psrc;
 351         dst = (struct sockaddr_in6 *)(void *)sc->gif_pdst;
 352
 353         /*
 354          * Check for address match.  Note that the check is for an incoming
 355          * packet.  We should compare the *source* address in our configuration
 356          * and the *destination* address of the packet, and vice versa.
 357          */
 358         if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
 359             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) {
 360                 return 0;
 361         }
 362
 363         /* martian filters on outer source - done in ip6_input */
 364
 365         /* ingress filters on outer source */
 366         if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 && ifp) {
 367                 struct sockaddr_in6 sin6;
 368                 struct rtentry *rt;
 369
 370                 bzero(&sin6, sizeof(sin6));
 371                 sin6.sin6_family = AF_INET6;
 372                 sin6.sin6_len = sizeof(struct sockaddr_in6);
 373                 sin6.sin6_addr = ip6->ip6_src;
 374
 375                 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0);
 376                 if (rt != NULL) {
 377                         RT_LOCK(rt);
 378                 }
 379                 if (!rt || rt->rt_ifp != ifp) {
 380 #if 0
 381                         log(LOG_WARNING, "%s: packet from %s dropped "
 382                             "due to ingress filter\n", if_name(&sc->gif_if),
 383                             ip6_sprintf(&sin6.sin6_addr));
 384 #endif
 385                         if (rt != NULL) {
 386                                 RT_UNLOCK(rt);
 387                                 rtfree(rt);
 388                         }
 389                         return 0;
 390                 }
 391                 RT_UNLOCK(rt);
 392                 rtfree(rt);
 393         }
 394
 395         return 128 * 2;
 396 }
 397
 398 /*
 399  * we know that we are in IFF_UP, outer address available, and outer family
 400  * matched the physical addr family.  see gif_encapcheck().
 401  * sanity check for arg should have been done in the caller.
 402  */
 403 int
 404 gif_encapcheck6(
 405         const struct mbuf *m,
 406         __unused int off,
 407         __unused int proto,
 408         void *arg)
 409 {
 410         struct ip6_hdr ip6;
 411         struct gif_softc *sc;
 412         struct ifnet *ifp;
 413
 414         /* sanity check done in caller */
 415         sc = (struct gif_softc *)arg;
 416
 417         GIF_LOCK_ASSERT(sc);
 418
 419         mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof(ip6), &ip6);
 420         ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
 421
 422         return gif_validate6(&ip6, sc, ifp);
 423 }