sys/netinet6/in6_gif.c

   1 /*      $FreeBSD: src/sys/netinet6/in6_gif.c,v 1.2.2.7 2003/01/23 21:06:47 sam Exp $    */
   2 /*      $DragonFly: src/sys/netinet6/in6_gif.c,v 1.18 2008/10/27 02:56:30 sephe Exp $   */
   3 /*      $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $        */
   4
   5 /*
   6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "opt_inet.h"
  35 #include "opt_inet6.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/socket.h>
  40 #include <sys/sockio.h>
  41 #include <sys/mbuf.h>
  42 #include <sys/errno.h>
  43 #include <sys/queue.h>
  44 #include <sys/syslog.h>
  45 #include <sys/protosw.h>
  46
  47 #include <sys/malloc.h>
  48
  49 #include <net/if.h>
  50 #include <net/route.h>
  51
  52 #include <netinet/in.h>
  53 #include <netinet/in_systm.h>
  54 #ifdef INET
  55 #include <netinet/ip.h>
  56 #endif
  57 #include <netinet/ip_encap.h>
  58 #ifdef INET6
  59 #include <netinet/ip6.h>
  60 #include <netinet6/ip6_var.h>
  61 #include <netinet6/in6_gif.h>
  62 #include <netinet6/in6_var.h>
  63 #endif
  64 #include <netinet6/ip6protosw.h>
  65 #include <netinet/ip_ecn.h>
  66 #ifdef INET6
  67 #include <netinet6/ip6_ecn.h>
  68 #endif
  69
  70 #include <net/gif/if_gif.h>
  71
  72 #include <net/net_osdep.h>
  73
  74 #ifdef INET6
  75 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
  76                          struct ifnet *);
  77
  78 extern  struct domain inet6domain;
  79 struct ip6protosw in6_gif_protosw =
  80 { SOCK_RAW,     &inet6domain,   0/*IPPROTO_IPV[46]*/,   PR_ATOMIC|PR_ADDR,
  81   in6_gif_input, rip6_output,   0,              rip6_ctloutput,
  82   cpu0_soport,  NULL,
  83   0,            0,              0,              0,
  84   &rip6_usrreqs
  85 };
  86
  87 int
  88 in6_gif_output(struct ifnet *ifp,
  89                int family,      /* family of the packet to be encapsulate. */
  90                struct mbuf *m)
  91 {
  92         struct gif_softc *sc = (struct gif_softc*)ifp;
  93         struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst;
  94         struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
  95         struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
  96         struct ip6_hdr *ip6;
  97         int proto;
  98         u_int8_t itos, otos;
  99
 100         if (sin6_src == NULL || sin6_dst == NULL ||
 101             sin6_src->sin6_family != AF_INET6 ||
 102             sin6_dst->sin6_family != AF_INET6) {
 103                 m_freem(m);
 104                 return EAFNOSUPPORT;
 105         }
 106
 107         switch (family) {
 108 #ifdef INET
 109         case AF_INET:
 110             {
 111                 struct ip *ip;
 112
 113                 proto = IPPROTO_IPV4;
 114                 if (m->m_len < sizeof(*ip)) {
 115                         m = m_pullup(m, sizeof(*ip));
 116                         if (!m)
 117                                 return ENOBUFS;
 118                 }
 119                 ip = mtod(m, struct ip *);
 120                 itos = ip->ip_tos;
 121                 break;
 122             }
 123 #endif
 124 #ifdef INET6
 125         case AF_INET6:
 126             {
 127                 struct ip6_hdr *ip6;
 128                 proto = IPPROTO_IPV6;
 129                 if (m->m_len < sizeof(*ip6)) {
 130                         m = m_pullup(m, sizeof(*ip6));
 131                         if (!m)
 132                                 return ENOBUFS;
 133                 }
 134                 ip6 = mtod(m, struct ip6_hdr *);
 135                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 136                 break;
 137             }
 138 #endif
 139         default:
 140 #ifdef DEBUG
 141                 kprintf("in6_gif_output: warning: unknown family %d passed\n",
 142                         family);
 143 #endif
 144                 m_freem(m);
 145                 return EAFNOSUPPORT;
 146         }
 147
 148         /* prepend new IP header */
 149         M_PREPEND(m, sizeof(struct ip6_hdr), MB_DONTWAIT);
 150         if (m && m->m_len < sizeof(struct ip6_hdr))
 151                 m = m_pullup(m, sizeof(struct ip6_hdr));
 152         if (m == NULL) {
 153                 kprintf("ENOBUFS in in6_gif_output %d\n", __LINE__);
 154                 return ENOBUFS;
 155         }
 156
 157         ip6 = mtod(m, struct ip6_hdr *);
 158         ip6->ip6_flow   = 0;
 159         ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 160         ip6->ip6_vfc    |= IPV6_VERSION;
 161         ip6->ip6_plen   = htons((u_short)m->m_pkthdr.len);
 162         ip6->ip6_nxt    = proto;
 163         ip6->ip6_hlim   = ip6_gif_hlim;
 164         ip6->ip6_src    = sin6_src->sin6_addr;
 165         /* bidirectional configured tunnel mode */
 166         if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
 167                 ip6->ip6_dst = sin6_dst->sin6_addr;
 168         else  {
 169                 m_freem(m);
 170                 return ENETUNREACH;
 171         }
 172         if (ifp->if_flags & IFF_LINK1)
 173                 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
 174         else
 175                 ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
 176         ip6->ip6_flow &= ~ntohl(0xff00000);
 177         ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
 178
 179         if (dst->sin6_family != sin6_dst->sin6_family ||
 180              !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
 181                 /* cache route doesn't match */
 182                 bzero(dst, sizeof(*dst));
 183                 dst->sin6_family = sin6_dst->sin6_family;
 184                 dst->sin6_len = sizeof(struct sockaddr_in6);
 185                 dst->sin6_addr = sin6_dst->sin6_addr;
 186                 if (sc->gif_ro6.ro_rt != NULL) {
 187                         RTFREE(sc->gif_ro6.ro_rt);
 188                         sc->gif_ro6.ro_rt = NULL;
 189                 }
 190 #if 0
 191                 sc->gif_if.if_mtu = GIF_MTU;
 192 #endif
 193         }
 194
 195         if (sc->gif_ro6.ro_rt == NULL) {
 196                 rtalloc((struct route *)&sc->gif_ro6);
 197                 if (sc->gif_ro6.ro_rt == NULL) {
 198                         m_freem(m);
 199                         return ENETUNREACH;
 200                 }
 201
 202                 /* if it constitutes infinite encapsulation, punt. */
 203                 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
 204                         m_freem(m);
 205                         return ENETUNREACH;     /*XXX*/
 206                 }
 207 #if 0
 208                 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
 209                         - sizeof(struct ip6_hdr);
 210 #endif
 211         }
 212
 213 #ifdef IPV6_MINMTU
 214         /*
 215          * force fragmentation to minimum MTU, to avoid path MTU discovery.
 216          * it is too painful to ask for resend of inner packet, to achieve
 217          * path MTU discovery for encapsulated packets.
 218          */
 219         return (ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL));
 220 #else
 221         return (ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL));
 222 #endif
 223 }
 224
 225 int
 226 in6_gif_input(struct mbuf **mp, int *offp, int proto)
 227 {
 228         struct mbuf *m = *mp;
 229         struct ifnet *gifp = NULL;
 230         struct ip6_hdr *ip6;
 231         int af = 0;
 232         u_int32_t otos;
 233
 234         ip6 = mtod(m, struct ip6_hdr *);
 235
 236         gifp = (struct ifnet *)encap_getarg(m);
 237
 238         if (gifp == NULL || !(gifp->if_flags & IFF_UP)) {
 239                 m_freem(m);
 240                 ip6stat.ip6s_nogif++;
 241                 return IPPROTO_DONE;
 242         }
 243
 244         otos = ip6->ip6_flow;
 245         m_adj(m, *offp);
 246
 247         switch (proto) {
 248 #ifdef INET
 249         case IPPROTO_IPV4:
 250             {
 251                 struct ip *ip;
 252                 u_int8_t otos8;
 253                 af = AF_INET;
 254                 otos8 = (ntohl(otos) >> 20) & 0xff;
 255                 if (m->m_len < sizeof(*ip)) {
 256                         m = m_pullup(m, sizeof(*ip));
 257                         if (!m)
 258                                 return IPPROTO_DONE;
 259                 }
 260                 ip = mtod(m, struct ip *);
 261                 if (gifp->if_flags & IFF_LINK1)
 262                         ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
 263                 else
 264                         ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
 265                 break;
 266             }
 267 #endif /* INET */
 268 #ifdef INET6
 269         case IPPROTO_IPV6:
 270             {
 271                 struct ip6_hdr *ip6;
 272                 af = AF_INET6;
 273                 if (m->m_len < sizeof(*ip6)) {
 274                         m = m_pullup(m, sizeof(*ip6));
 275                         if (!m)
 276                                 return IPPROTO_DONE;
 277                 }
 278                 ip6 = mtod(m, struct ip6_hdr *);
 279                 if (gifp->if_flags & IFF_LINK1)
 280                         ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
 281                 else
 282                         ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
 283                 break;
 284             }
 285 #endif
 286         default:
 287                 ip6stat.ip6s_nogif++;
 288                 m_freem(m);
 289                 return IPPROTO_DONE;
 290         }
 291
 292         gif_input(m, af, gifp);
 293         return IPPROTO_DONE;
 294 }
 295
 296 /*
 297  * validate outer address.
 298  */
 299 static int
 300 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
 301               struct ifnet *ifp)
 302 {
 303         struct sockaddr_in6 *src, *dst;
 304
 305         src = (struct sockaddr_in6 *)sc->gif_psrc;
 306         dst = (struct sockaddr_in6 *)sc->gif_pdst;
 307
 308         /*
 309          * Check for address match.  Note that the check is for an incoming
 310          * packet.  We should compare the *source* address in our configuration
 311          * and the *destination* address of the packet, and vice versa.
 312          */
 313         if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
 314             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
 315                 return 0;
 316
 317         /* martian filters on outer source - done in ip6_input */
 318
 319         /* ingress filters on outer source */
 320         if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp) {
 321                 struct sockaddr_in6 sin6;
 322                 struct rtentry *rt;
 323
 324                 bzero(&sin6, sizeof(sin6));
 325                 sin6.sin6_family = AF_INET6;
 326                 sin6.sin6_len = sizeof(struct sockaddr_in6);
 327                 sin6.sin6_addr = ip6->ip6_src;
 328                 sin6.sin6_scope_id = 0; /* XXX */
 329
 330                 rt = rtpurelookup((struct sockaddr *)&sin6);
 331                 if (rt != NULL)
 332                         --rt->rt_refcnt;
 333                 if (rt == NULL || rt->rt_ifp != ifp) {
 334 #if 0
 335                         log(LOG_WARNING, "%s: packet from %s dropped "
 336                             "due to ingress filter\n", if_name(&sc->gif_if),
 337                             ip6_sprintf(&sin6.sin6_addr));
 338 #endif
 339                         return 0;
 340                 }
 341         }
 342
 343         return 128 * 2;
 344 }
 345
 346 /*
 347  * we know that we are in IFF_UP, outer address available, and outer family
 348  * matched the physical addr family.  see gif_encapcheck().
 349  * sanity check for arg should have been done in the caller.
 350  */
 351 int
 352 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg)
 353 {
 354         struct ip6_hdr ip6;
 355         struct gif_softc *sc;
 356         struct ifnet *ifp;
 357
 358         /* sanity check done in caller */
 359         sc = (struct gif_softc *)arg;
 360
 361         m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
 362         ifp = (m->m_flags & M_PKTHDR) ? m->m_pkthdr.rcvif : NULL;
 363
 364         return gif_validate6(&ip6, sc, ifp);
 365 }
 366
 367 int
 368 in6_gif_attach(struct gif_softc *sc)
 369 {
 370         sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
 371             (struct protosw *)&in6_gif_protosw, sc);
 372         if (sc->encap_cookie6 == NULL)
 373                 return EEXIST;
 374         return 0;
 375 }
 376
 377 int
 378 in6_gif_detach(struct gif_softc *sc)
 379 {
 380         int error;
 381
 382         error = encap_detach(sc->encap_cookie6);
 383         if (error == 0)
 384                 sc->encap_cookie6 = NULL;
 385         return error;
 386 }
 387
 388 #endif /* INET6 */