bsd/netinet/in_gif.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, 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 /*      $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ */
  29
  30 /*
  31  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  32  * All rights reserved.
  33  *
  34  * Redistribution and use in source and binary forms, with or without
  35  * modification, are permitted provided that the following conditions
  36  * are met:
  37  * 1. Redistributions of source code must retain the above copyright
  38  *    notice, this list of conditions and the following disclaimer.
  39  * 2. Redistributions in binary form must reproduce the above copyright
  40  *    notice, this list of conditions and the following disclaimer in the
  41  *    documentation and/or other materials provided with the distribution.
  42  * 3. Neither the name of the project nor the names of its contributors
  43  *    may be used to endorse or promote products derived from this software
  44  *    without specific prior written permission.
  45  *
  46  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  49  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  56  * SUCH DAMAGE.
  57  */
  58
  59
  60 #include <sys/param.h>
  61 #include <sys/systm.h>
  62 #include <sys/socket.h>
  63 #include <sys/sockio.h>
  64 #include <sys/mbuf.h>
  65 #include <sys/errno.h>
  66 #include <sys/kernel.h>
  67 #include <sys/sysctl.h>
  68
  69 #include <sys/malloc.h>
  70
  71 #include <net/if.h>
  72 #include <net/route.h>
  73
  74 #include <netinet/in.h>
  75 #include <netinet/in_systm.h>
  76 #include <netinet/ip.h>
  77 #include <netinet/ip_var.h>
  78 #include <netinet/in_gif.h>
  79 #include <netinet/in_var.h>
  80 #include <netinet/ip_encap.h>
  81 #include <netinet/ip_ecn.h>
  82
  83 #if INET6
  84 #include <netinet/ip6.h>
  85 #endif
  86
  87 #if MROUTING
  88 #include <netinet/ip_mroute.h>
  89 #endif /* MROUTING */
  90
  91 #include <net/if_gif.h>
  92
  93 #include <net/net_osdep.h>
  94
  95 int ip_gif_ttl = GIF_TTL;
  96 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
  97         &ip_gif_ttl,    0, "");
  98
  99 int
 100 in_gif_output(
 101         struct ifnet    *ifp,
 102         int             family,
 103         struct mbuf     *m,
 104         struct rtentry *rt)
 105 {
 106         struct gif_softc *sc = (struct gif_softc*)ifp;
 107         struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
 108         struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
 109         struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
 110         struct ip iphdr;        /* capsule IP header, host byte ordered */
 111         int proto, error;
 112         u_int8_t tos;
 113
 114         if (sin_src == NULL || sin_dst == NULL ||
 115             sin_src->sin_family != AF_INET ||
 116             sin_dst->sin_family != AF_INET) {
 117                 m_freem(m);
 118                 return EAFNOSUPPORT;
 119         }
 120
 121         switch (family) {
 122 #if INET
 123         case AF_INET:
 124             {
 125                 struct ip *ip;
 126
 127                 proto = IPPROTO_IPV4;
 128                 if (m->m_len < sizeof(*ip)) {
 129                         m = m_pullup(m, sizeof(*ip));
 130                         if (!m)
 131                                 return ENOBUFS;
 132                 }
 133                 ip = mtod(m, struct ip *);
 134                 tos = ip->ip_tos;
 135                 break;
 136             }
 137 #endif /*INET*/
 138 #if INET6
 139         case AF_INET6:
 140             {
 141                 struct ip6_hdr *ip6;
 142                 proto = IPPROTO_IPV6;
 143                 if (m->m_len < sizeof(*ip6)) {
 144                         m = m_pullup(m, sizeof(*ip6));
 145                         if (!m)
 146                                 return ENOBUFS;
 147                 }
 148                 ip6 = mtod(m, struct ip6_hdr *);
 149                 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 150                 break;
 151             }
 152 #endif /*INET6*/
 153         default:
 154 #if DEBUG
 155                 printf("in_gif_output: warning: unknown family %d passed\n",
 156                         family);
 157 #endif
 158                 m_freem(m);
 159                 return EAFNOSUPPORT;
 160         }
 161
 162         bzero(&iphdr, sizeof(iphdr));
 163         iphdr.ip_src = sin_src->sin_addr;
 164         /* bidirectional configured tunnel mode */
 165         if (sin_dst->sin_addr.s_addr != INADDR_ANY)
 166                 iphdr.ip_dst = sin_dst->sin_addr;
 167         else {
 168                 m_freem(m);
 169                 return ENETUNREACH;
 170         }
 171         iphdr.ip_p = proto;
 172         /* version will be set in ip_output() */
 173         iphdr.ip_ttl = ip_gif_ttl;
 174         iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
 175         if (ifp->if_flags & IFF_LINK1)
 176                 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
 177         else
 178                 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
 179
 180         /* prepend new IP header */
 181         M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
 182         if (m && m->m_len < sizeof(struct ip))
 183                 m = m_pullup(m, sizeof(struct ip));
 184         if (m == NULL) {
 185                 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
 186                 return ENOBUFS;
 187         }
 188         bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
 189
 190         if (dst->sin_family != sin_dst->sin_family ||
 191             dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
 192                 /* cache route doesn't match */
 193                 dst->sin_family = sin_dst->sin_family;
 194                 dst->sin_len = sizeof(struct sockaddr_in);
 195                 dst->sin_addr = sin_dst->sin_addr;
 196                 if (sc->gif_ro.ro_rt) {
 197                         rtfree(sc->gif_ro.ro_rt);
 198                         sc->gif_ro.ro_rt = NULL;
 199                 }
 200 #if 0
 201                 sc->gif_if.if_mtu = GIF_MTU;
 202 #endif
 203         }
 204
 205         if (sc->gif_ro.ro_rt == NULL) {
 206                 rtalloc(&sc->gif_ro);
 207                 if (sc->gif_ro.ro_rt == NULL) {
 208                         m_freem(m);
 209                         return ENETUNREACH;
 210                 }
 211
 212                 /* if it constitutes infinite encapsulation, punt. */
 213                 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
 214                         m_freem(m);
 215                         return ENETUNREACH;     /*XXX*/
 216                 }
 217 #if 0
 218                 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
 219                         - sizeof(struct ip);
 220 #endif
 221         }
 222
 223         error = ip_output(m, NULL, &sc->gif_ro, 0, NULL);
 224         return(error);
 225 }
 226
 227 void
 228 in_gif_input(m, off)
 229         struct mbuf *m;
 230         int off;
 231 {
 232         struct ifnet *gifp = NULL;
 233         struct ip *ip;
 234         int i, af, proto;
 235         u_int8_t otos;
 236
 237         ip = mtod(m, struct ip *);
 238         proto = ip->ip_p;
 239
 240
 241         gifp = (struct ifnet *)encap_getarg(m);
 242
 243         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 244                 m_freem(m);
 245                 ipstat.ips_nogif++;
 246                 return;
 247         }
 248
 249         otos = ip->ip_tos;
 250         m_adj(m, off);
 251
 252         switch (proto) {
 253 #if INET
 254         case IPPROTO_IPV4:
 255             {
 256                 struct ip *ip;
 257                 af = AF_INET;
 258                 if (m->m_len < sizeof(*ip)) {
 259                         m = m_pullup(m, sizeof(*ip));
 260                         if (!m)
 261                                 return;
 262                 }
 263                 ip = mtod(m, struct ip *);
 264                 if (gifp->if_flags & IFF_LINK1)
 265                         ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
 266                 else
 267                         ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
 268                 break;
 269             }
 270 #endif
 271 #if INET6
 272         case IPPROTO_IPV6:
 273             {
 274                 struct ip6_hdr *ip6;
 275                 u_int8_t itos;
 276                 af = AF_INET6;
 277                 if (m->m_len < sizeof(*ip6)) {
 278                         m = m_pullup(m, sizeof(*ip6));
 279                         if (!m)
 280                                 return;
 281                 }
 282                 ip6 = mtod(m, struct ip6_hdr *);
 283                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 284                 if (gifp->if_flags & IFF_LINK1)
 285                         ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
 286                 else
 287                         ip_ecn_egress(ECN_NOCARE, &otos, &itos);
 288                 ip6->ip6_flow &= ~htonl(0xff << 20);
 289                 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
 290                 break;
 291             }
 292 #endif /* INET6 */
 293         default:
 294                 ipstat.ips_nogif++;
 295                 m_freem(m);
 296                 return;
 297         }
 298 #ifdef __APPLE__
 299         /* Should we free m if dlil_input returns an error? */
 300         if (m->m_pkthdr.rcvif)  /* replace the rcvif by gifp for dlil to route it correctly */
 301                 m->m_pkthdr.rcvif = gifp;
 302         dlil_input_packet(gifp, m, NULL);
 303 #else
 304         gif_input(m, af, gifp);
 305 #endif
 306         return;
 307 }
 308
 309 /*
 310  * we know that we are in IFF_UP, outer address available, and outer family
 311  * matched the physical addr family.  see gif_encapcheck().
 312  */
 313 int
 314 gif_encapcheck4(m, off, proto, arg)
 315         const struct mbuf *m;
 316         int off;
 317         int proto;
 318         void *arg;
 319 {
 320         struct ip ip;
 321         struct gif_softc *sc;
 322         struct sockaddr_in *src, *dst;
 323         int addrmatch;
 324         struct in_ifaddr *ia4;
 325
 326         /* sanity check done in caller */
 327         sc = (struct gif_softc *)arg;
 328         src = (struct sockaddr_in *)sc->gif_psrc;
 329         dst = (struct sockaddr_in *)sc->gif_pdst;
 330
 331         /* LINTED const cast */
 332         m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip);
 333
 334         /* check for address match */
 335         addrmatch = 0;
 336         if (src->sin_addr.s_addr == ip.ip_dst.s_addr)
 337                 addrmatch |= 1;
 338         if (dst->sin_addr.s_addr == ip.ip_src.s_addr)
 339                 addrmatch |= 2;
 340         if (addrmatch != 3)
 341                 return 0;
 342
 343         /* martian filters on outer source - NOT done in ip_input! */
 344         if (IN_MULTICAST(ntohl(ip.ip_src.s_addr)))
 345                 return 0;
 346         switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) {
 347         case 0: case 127: case 255:
 348                 return 0;
 349         }
 350         /* reject packets with broadcast on source */
 351         lck_mtx_lock(rt_mtx);
 352         for (ia4 = TAILQ_FIRST(&in_ifaddrhead); ia4;
 353              ia4 = TAILQ_NEXT(ia4, ia_link))
 354         {
 355                 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
 356                         continue;
 357                 if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
 358                         lck_mtx_unlock(rt_mtx);
 359                         return 0;
 360                 }
 361         }
 362         lck_mtx_unlock(rt_mtx);
 363
 364         /* ingress filters on outer source */
 365         if ((sc->gif_if.if_flags & IFF_LINK2) == 0 &&
 366             (m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) {
 367                 struct sockaddr_in sin;
 368                 struct rtentry *rt;
 369
 370                 bzero(&sin, sizeof(sin));
 371                 sin.sin_family = AF_INET;
 372                 sin.sin_len = sizeof(struct sockaddr_in);
 373                 sin.sin_addr = ip.ip_src;
 374                 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
 375                 if (!rt || rt->rt_ifp != m->m_pkthdr.rcvif) {
 376 #if 0
 377                         log(LOG_WARNING, "%s: packet from 0x%x dropped "
 378                             "due to ingress filter\n", if_name(&sc->gif_if),
 379                             (u_int32_t)ntohl(sin.sin_addr.s_addr));
 380 #endif
 381                         if (rt)
 382                                 rtfree(rt);
 383                         return 0;
 384                 }
 385                 rtfree(rt);
 386         }
 387
 388         return 32 * 2;
 389 }