bsd/netinet/in_gif.c

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*      $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 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/kernel.h>
  69 #include <sys/sysctl.h>
  70
  71 #include <sys/malloc.h>
  72
  73 #include <net/if.h>
  74 #include <net/route.h>
  75
  76 #include <netinet/in.h>
  77 #include <netinet/in_systm.h>
  78 #include <netinet/ip.h>
  79 #include <netinet/ip_var.h>
  80 #include <netinet/in_gif.h>
  81 #include <netinet/in_var.h>
  82 #include <netinet/ip_encap.h>
  83 #include <netinet/ip_ecn.h>
  84
  85 #if INET6
  86 #include <netinet/ip6.h>
  87 #endif
  88
  89 #if MROUTING
  90 #include <netinet/ip_mroute.h>
  91 #endif /* MROUTING */
  92
  93 #include <net/if_gif.h>
  94
  95 #include <net/net_osdep.h>
  96
  97 int ip_gif_ttl = GIF_TTL;
  98 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
  99         &ip_gif_ttl,    0, "");
 100
 101 int
 102 in_gif_output(
 103         struct ifnet    *ifp,
 104         int             family,
 105         struct mbuf     *m,
 106         struct rtentry *rt)
 107 {
 108         struct gif_softc *sc = (struct gif_softc*)ifp;
 109         struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
 110         struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
 111         struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
 112         struct ip iphdr;        /* capsule IP header, host byte ordered */
 113         int proto, error;
 114         u_int8_t tos;
 115
 116         if (sin_src == NULL || sin_dst == NULL ||
 117             sin_src->sin_family != AF_INET ||
 118             sin_dst->sin_family != AF_INET) {
 119                 m_freem(m);
 120                 return EAFNOSUPPORT;
 121         }
 122
 123         switch (family) {
 124 #if INET
 125         case AF_INET:
 126             {
 127                 struct ip *ip;
 128
 129                 proto = IPPROTO_IPV4;
 130                 if (m->m_len < sizeof(*ip)) {
 131                         m = m_pullup(m, sizeof(*ip));
 132                         if (!m)
 133                                 return ENOBUFS;
 134                 }
 135                 ip = mtod(m, struct ip *);
 136                 tos = ip->ip_tos;
 137                 break;
 138             }
 139 #endif /*INET*/
 140 #if INET6
 141         case AF_INET6:
 142             {
 143                 struct ip6_hdr *ip6;
 144                 proto = IPPROTO_IPV6;
 145                 if (m->m_len < sizeof(*ip6)) {
 146                         m = m_pullup(m, sizeof(*ip6));
 147                         if (!m)
 148                                 return ENOBUFS;
 149                 }
 150                 ip6 = mtod(m, struct ip6_hdr *);
 151                 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 152                 break;
 153             }
 154 #endif /*INET6*/
 155         default:
 156 #if DEBUG
 157                 printf("in_gif_output: warning: unknown family %d passed\n",
 158                         family);
 159 #endif
 160                 m_freem(m);
 161                 return EAFNOSUPPORT;
 162         }
 163
 164         bzero(&iphdr, sizeof(iphdr));
 165         iphdr.ip_src = sin_src->sin_addr;
 166         /* bidirectional configured tunnel mode */
 167         if (sin_dst->sin_addr.s_addr != INADDR_ANY)
 168                 iphdr.ip_dst = sin_dst->sin_addr;
 169         else {
 170                 m_freem(m);
 171                 return ENETUNREACH;
 172         }
 173         iphdr.ip_p = proto;
 174         /* version will be set in ip_output() */
 175         iphdr.ip_ttl = ip_gif_ttl;
 176         iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
 177         if (ifp->if_flags & IFF_LINK1)
 178                 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
 179         else
 180                 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
 181
 182         /* prepend new IP header */
 183         M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
 184         if (m && m->m_len < sizeof(struct ip))
 185                 m = m_pullup(m, sizeof(struct ip));
 186         if (m == NULL) {
 187                 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
 188                 return ENOBUFS;
 189         }
 190         bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
 191
 192         if (dst->sin_family != sin_dst->sin_family ||
 193             dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
 194                 /* cache route doesn't match */
 195                 dst->sin_family = sin_dst->sin_family;
 196                 dst->sin_len = sizeof(struct sockaddr_in);
 197                 dst->sin_addr = sin_dst->sin_addr;
 198                 if (sc->gif_ro.ro_rt) {
 199                         rtfree(sc->gif_ro.ro_rt);
 200                         sc->gif_ro.ro_rt = NULL;
 201                 }
 202 #if 0
 203                 sc->gif_if.if_mtu = GIF_MTU;
 204 #endif
 205         }
 206
 207         if (sc->gif_ro.ro_rt == NULL) {
 208                 rtalloc(&sc->gif_ro);
 209                 if (sc->gif_ro.ro_rt == NULL) {
 210                         m_freem(m);
 211                         return ENETUNREACH;
 212                 }
 213
 214                 /* if it constitutes infinite encapsulation, punt. */
 215                 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
 216                         m_freem(m);
 217                         return ENETUNREACH;     /*XXX*/
 218                 }
 219 #if 0
 220                 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
 221                         - sizeof(struct ip);
 222 #endif
 223         }
 224
 225         error = ip_output(m, NULL, &sc->gif_ro, 0, NULL);
 226         return(error);
 227 }
 228
 229 void
 230 in_gif_input(m, off)
 231         struct mbuf *m;
 232         int off;
 233 {
 234         struct ifnet *gifp = NULL;
 235         struct ip *ip;
 236         int i, af, proto;
 237         u_int8_t otos;
 238
 239         ip = mtod(m, struct ip *);
 240         proto = ip->ip_p;
 241
 242
 243         gifp = (struct ifnet *)encap_getarg(m);
 244
 245         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 246                 m_freem(m);
 247                 ipstat.ips_nogif++;
 248                 return;
 249         }
 250
 251         otos = ip->ip_tos;
 252         m_adj(m, off);
 253
 254         switch (proto) {
 255 #if INET
 256         case IPPROTO_IPV4:
 257             {
 258                 struct ip *ip;
 259                 af = AF_INET;
 260                 if (m->m_len < sizeof(*ip)) {
 261                         m = m_pullup(m, sizeof(*ip));
 262                         if (!m)
 263                                 return;
 264                 }
 265                 ip = mtod(m, struct ip *);
 266                 if (gifp->if_flags & IFF_LINK1)
 267                         ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
 268                 else
 269                         ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
 270                 break;
 271             }
 272 #endif
 273 #if INET6
 274         case IPPROTO_IPV6:
 275             {
 276                 struct ip6_hdr *ip6;
 277                 u_int8_t itos;
 278                 af = AF_INET6;
 279                 if (m->m_len < sizeof(*ip6)) {
 280                         m = m_pullup(m, sizeof(*ip6));
 281                         if (!m)
 282                                 return;
 283                 }
 284                 ip6 = mtod(m, struct ip6_hdr *);
 285                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 286                 if (gifp->if_flags & IFF_LINK1)
 287                         ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
 288                 else
 289                         ip_ecn_egress(ECN_NOCARE, &otos, &itos);
 290                 ip6->ip6_flow &= ~htonl(0xff << 20);
 291                 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
 292                 break;
 293             }
 294 #endif /* INET6 */
 295         default:
 296                 ipstat.ips_nogif++;
 297                 m_freem(m);
 298                 return;
 299         }
 300 #ifdef __APPLE__
 301         /* Should we free m if dlil_input returns an error? */
 302         if (m->m_pkthdr.rcvif)  /* replace the rcvif by gifp for dlil to route it correctly */
 303                 m->m_pkthdr.rcvif = gifp;
 304         dlil_input_packet(gifp, m, NULL);
 305 #else
 306         gif_input(m, af, gifp);
 307 #endif
 308         return;
 309 }
 310
 311 /*
 312  * we know that we are in IFF_UP, outer address available, and outer family
 313  * matched the physical addr family.  see gif_encapcheck().
 314  */
 315 int
 316 gif_encapcheck4(m, off, proto, arg)
 317         const struct mbuf *m;
 318         int off;
 319         int proto;
 320         void *arg;
 321 {
 322         struct ip ip;
 323         struct gif_softc *sc;
 324         struct sockaddr_in *src, *dst;
 325         int addrmatch;
 326         struct in_ifaddr *ia4;
 327
 328         /* sanity check done in caller */
 329         sc = (struct gif_softc *)arg;
 330         src = (struct sockaddr_in *)sc->gif_psrc;
 331         dst = (struct sockaddr_in *)sc->gif_pdst;
 332
 333         /* LINTED const cast */
 334         m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip);
 335
 336         /* check for address match */
 337         addrmatch = 0;
 338         if (src->sin_addr.s_addr == ip.ip_dst.s_addr)
 339                 addrmatch |= 1;
 340         if (dst->sin_addr.s_addr == ip.ip_src.s_addr)
 341                 addrmatch |= 2;
 342         if (addrmatch != 3)
 343                 return 0;
 344
 345         /* martian filters on outer source - NOT done in ip_input! */
 346         if (IN_MULTICAST(ntohl(ip.ip_src.s_addr)))
 347                 return 0;
 348         switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) {
 349         case 0: case 127: case 255:
 350                 return 0;
 351         }
 352         /* reject packets with broadcast on source */
 353         lck_mtx_lock(rt_mtx);
 354         for (ia4 = TAILQ_FIRST(&in_ifaddrhead); ia4;
 355              ia4 = TAILQ_NEXT(ia4, ia_link))
 356         {
 357                 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
 358                         continue;
 359                 if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
 360                         lck_mtx_unlock(rt_mtx);
 361                         return 0;
 362                 }
 363         }
 364         lck_mtx_unlock(rt_mtx);
 365
 366         /* ingress filters on outer source */
 367         if ((sc->gif_if.if_flags & IFF_LINK2) == 0 &&
 368             (m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) {
 369                 struct sockaddr_in sin;
 370                 struct rtentry *rt;
 371
 372                 bzero(&sin, sizeof(sin));
 373                 sin.sin_family = AF_INET;
 374                 sin.sin_len = sizeof(struct sockaddr_in);
 375                 sin.sin_addr = ip.ip_src;
 376                 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
 377                 if (!rt || rt->rt_ifp != m->m_pkthdr.rcvif) {
 378 #if 0
 379                         log(LOG_WARNING, "%s: packet from 0x%x dropped "
 380                             "due to ingress filter\n", if_name(&sc->gif_if),
 381                             (u_int32_t)ntohl(sin.sin_addr.s_addr));
 382 #endif
 383                         if (rt)
 384                                 rtfree(rt);
 385                         return 0;
 386                 }
 387                 rtfree(rt);
 388         }
 389
 390         return 32 * 2;
 391 }