bsd/netinet/in_gif.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*      $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ */
  26
  27 /*
  28  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
  29  * All rights reserved.
  30  *
  31  * Redistribution and use in source and binary forms, with or without
  32  * modification, are permitted provided that the following conditions
  33  * are met:
  34  * 1. Redistributions of source code must retain the above copyright
  35  *    notice, this list of conditions and the following disclaimer.
  36  * 2. Redistributions in binary form must reproduce the above copyright
  37  *    notice, this list of conditions and the following disclaimer in the
  38  *    documentation and/or other materials provided with the distribution.
  39  * 3. Neither the name of the project nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  */
  55
  56
  57 #include <sys/param.h>
  58 #include <sys/systm.h>
  59 #include <sys/socket.h>
  60 #include <sys/sockio.h>
  61 #include <sys/mbuf.h>
  62 #include <sys/errno.h>
  63 #include <sys/kernel.h>
  64 #include <sys/sysctl.h>
  65
  66 #include <sys/malloc.h>
  67
  68 #include <net/if.h>
  69 #include <net/route.h>
  70
  71 #include <netinet/in.h>
  72 #include <netinet/in_systm.h>
  73 #include <netinet/ip.h>
  74 #include <netinet/ip_var.h>
  75 #include <netinet/in_gif.h>
  76 #include <netinet/in_var.h>
  77 #include <netinet/ip_encap.h>
  78 #include <netinet/ip_ecn.h>
  79
  80 #if INET6
  81 #include <netinet/ip6.h>
  82 #endif
  83
  84 #if MROUTING
  85 #include <netinet/ip_mroute.h>
  86 #endif /* MROUTING */
  87
  88 #include <net/if_gif.h>
  89
  90 #include <net/net_osdep.h>
  91
  92 int ip_gif_ttl = GIF_TTL;
  93 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
  94         &ip_gif_ttl,    0, "");
  95
  96 int
  97 in_gif_output(ifp, family, m, rt)
  98         struct ifnet    *ifp;
  99         int             family;
 100         struct mbuf     *m;
 101         struct rtentry *rt;
 102 {
 103         struct gif_softc *sc = (struct gif_softc*)ifp;
 104         struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
 105         struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
 106         struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
 107         struct ip iphdr;        /* capsule IP header, host byte ordered */
 108         int proto, error;
 109         u_int8_t tos;
 110
 111         if (sin_src == NULL || sin_dst == NULL ||
 112             sin_src->sin_family != AF_INET ||
 113             sin_dst->sin_family != AF_INET) {
 114                 m_freem(m);
 115                 return EAFNOSUPPORT;
 116         }
 117
 118         switch (family) {
 119 #if INET
 120         case AF_INET:
 121             {
 122                 struct ip *ip;
 123
 124                 proto = IPPROTO_IPV4;
 125                 if (m->m_len < sizeof(*ip)) {
 126                         m = m_pullup(m, sizeof(*ip));
 127                         if (!m)
 128                                 return ENOBUFS;
 129                 }
 130                 ip = mtod(m, struct ip *);
 131                 tos = ip->ip_tos;
 132                 break;
 133             }
 134 #endif /*INET*/
 135 #if INET6
 136         case AF_INET6:
 137             {
 138                 struct ip6_hdr *ip6;
 139                 proto = IPPROTO_IPV6;
 140                 if (m->m_len < sizeof(*ip6)) {
 141                         m = m_pullup(m, sizeof(*ip6));
 142                         if (!m)
 143                                 return ENOBUFS;
 144                 }
 145                 ip6 = mtod(m, struct ip6_hdr *);
 146                 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 147                 break;
 148             }
 149 #endif /*INET6*/
 150         default:
 151 #if DEBUG
 152                 printf("in_gif_output: warning: unknown family %d passed\n",
 153                         family);
 154 #endif
 155                 m_freem(m);
 156                 return EAFNOSUPPORT;
 157         }
 158
 159         bzero(&iphdr, sizeof(iphdr));
 160         iphdr.ip_src = sin_src->sin_addr;
 161         /* bidirectional configured tunnel mode */
 162         if (sin_dst->sin_addr.s_addr != INADDR_ANY)
 163                 iphdr.ip_dst = sin_dst->sin_addr;
 164         else {
 165                 m_freem(m);
 166                 return ENETUNREACH;
 167         }
 168         iphdr.ip_p = proto;
 169         /* version will be set in ip_output() */
 170         iphdr.ip_ttl = ip_gif_ttl;
 171         iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
 172         if (ifp->if_flags & IFF_LINK1)
 173                 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
 174         else
 175                 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
 176
 177         /* prepend new IP header */
 178         M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
 179         if (m && m->m_len < sizeof(struct ip))
 180                 m = m_pullup(m, sizeof(struct ip));
 181         if (m == NULL) {
 182                 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
 183                 return ENOBUFS;
 184         }
 185         bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
 186
 187         if (dst->sin_family != sin_dst->sin_family ||
 188             dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
 189                 /* cache route doesn't match */
 190                 dst->sin_family = sin_dst->sin_family;
 191                 dst->sin_len = sizeof(struct sockaddr_in);
 192                 dst->sin_addr = sin_dst->sin_addr;
 193                 if (sc->gif_ro.ro_rt) {
 194                         rtfree(sc->gif_ro.ro_rt);
 195                         sc->gif_ro.ro_rt = NULL;
 196                 }
 197 #if 0
 198                 sc->gif_if.if_mtu = GIF_MTU;
 199 #endif
 200         }
 201
 202         if (sc->gif_ro.ro_rt == NULL) {
 203                 rtalloc(&sc->gif_ro);
 204                 if (sc->gif_ro.ro_rt == NULL) {
 205                         m_freem(m);
 206                         return ENETUNREACH;
 207                 }
 208
 209                 /* if it constitutes infinite encapsulation, punt. */
 210                 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
 211                         m_freem(m);
 212                         return ENETUNREACH;     /*XXX*/
 213                 }
 214 #if 0
 215                 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
 216                         - sizeof(struct ip);
 217 #endif
 218         }
 219
 220         error = ip_output(m, NULL, &sc->gif_ro, 0, NULL);
 221         return(error);
 222 }
 223
 224 void
 225 in_gif_input(m, off)
 226         struct mbuf *m;
 227         int off;
 228 {
 229         struct ifnet *gifp = NULL;
 230         struct ip *ip;
 231         int i, af, proto;
 232         u_int8_t otos;
 233
 234         ip = mtod(m, struct ip *);
 235         proto = ip->ip_p;
 236
 237
 238         gifp = (struct ifnet *)encap_getarg(m);
 239
 240         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 241                 m_freem(m);
 242                 ipstat.ips_nogif++;
 243                 return;
 244         }
 245
 246         otos = ip->ip_tos;
 247         m_adj(m, off);
 248
 249         switch (proto) {
 250 #if INET
 251         case IPPROTO_IPV4:
 252             {
 253                 struct ip *ip;
 254                 af = AF_INET;
 255                 if (m->m_len < sizeof(*ip)) {
 256                         m = m_pullup(m, sizeof(*ip));
 257                         if (!m)
 258                                 return;
 259                 }
 260                 ip = mtod(m, struct ip *);
 261                 if (gifp->if_flags & IFF_LINK1)
 262                         ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
 263                 else
 264                         ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
 265                 break;
 266             }
 267 #endif
 268 #if INET6
 269         case IPPROTO_IPV6:
 270             {
 271                 struct ip6_hdr *ip6;
 272                 u_int8_t itos;
 273                 af = AF_INET6;
 274                 if (m->m_len < sizeof(*ip6)) {
 275                         m = m_pullup(m, sizeof(*ip6));
 276                         if (!m)
 277                                 return;
 278                 }
 279                 ip6 = mtod(m, struct ip6_hdr *);
 280                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 281                 if (gifp->if_flags & IFF_LINK1)
 282                         ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
 283                 else
 284                         ip_ecn_egress(ECN_NOCARE, &otos, &itos);
 285                 ip6->ip6_flow &= ~htonl(0xff << 20);
 286                 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
 287                 break;
 288             }
 289 #endif /* INET6 */
 290         default:
 291                 ipstat.ips_nogif++;
 292                 m_freem(m);
 293                 return;
 294         }
 295 #ifdef __APPLE__
 296         /* Should we free m if dlil_input returns an error? */
 297         if (m->m_pkthdr.rcvif)  /* replace the rcvif by gifp for dlil to route it correctly */
 298                 m->m_pkthdr.rcvif = gifp;
 299         dlil_input_packet(gifp, m, NULL);
 300 #else
 301         gif_input(m, af, gifp);
 302 #endif
 303         return;
 304 }
 305
 306 /*
 307  * we know that we are in IFF_UP, outer address available, and outer family
 308  * matched the physical addr family.  see gif_encapcheck().
 309  */
 310 int
 311 gif_encapcheck4(m, off, proto, arg)
 312         const struct mbuf *m;
 313         int off;
 314         int proto;
 315         void *arg;
 316 {
 317         struct ip ip;
 318         struct gif_softc *sc;
 319         struct sockaddr_in *src, *dst;
 320         int addrmatch;
 321         struct in_ifaddr *ia4;
 322
 323         /* sanity check done in caller */
 324         sc = (struct gif_softc *)arg;
 325         src = (struct sockaddr_in *)sc->gif_psrc;
 326         dst = (struct sockaddr_in *)sc->gif_pdst;
 327
 328         /* LINTED const cast */
 329         m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip);
 330
 331         /* check for address match */
 332         addrmatch = 0;
 333         if (src->sin_addr.s_addr == ip.ip_dst.s_addr)
 334                 addrmatch |= 1;
 335         if (dst->sin_addr.s_addr == ip.ip_src.s_addr)
 336                 addrmatch |= 2;
 337         if (addrmatch != 3)
 338                 return 0;
 339
 340         /* martian filters on outer source - NOT done in ip_input! */
 341         if (IN_MULTICAST(ntohl(ip.ip_src.s_addr)))
 342                 return 0;
 343         switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) {
 344         case 0: case 127: case 255:
 345                 return 0;
 346         }
 347         /* reject packets with broadcast on source */
 348         for (ia4 = TAILQ_FIRST(&in_ifaddrhead); ia4;
 349              ia4 = TAILQ_NEXT(ia4, ia_link))
 350         {
 351                 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
 352                         continue;
 353                 if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
 354                         return 0;
 355         }
 356
 357         /* ingress filters on outer source */
 358         if ((sc->gif_if.if_flags & IFF_LINK2) == 0 &&
 359             (m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) {
 360                 struct sockaddr_in sin;
 361                 struct rtentry *rt;
 362
 363                 bzero(&sin, sizeof(sin));
 364                 sin.sin_family = AF_INET;
 365                 sin.sin_len = sizeof(struct sockaddr_in);
 366                 sin.sin_addr = ip.ip_src;
 367                 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
 368                 if (!rt || rt->rt_ifp != m->m_pkthdr.rcvif) {
 369 #if 0
 370                         log(LOG_WARNING, "%s: packet from 0x%x dropped "
 371                             "due to ingress filter\n", if_name(&sc->gif_if),
 372                             (u_int32_t)ntohl(sin.sin_addr.s_addr));
 373 #endif
 374                         if (rt)
 375                                 rtfree(rt);
 376                         return 0;
 377                 }
 378                 rtfree(rt);
 379         }
 380
 381         return 32 * 2;
 382 }