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 /*      $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $        */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include "opt_inet.h"
  34 #include "opt_inet6.h"
  35
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/socket.h>
  39 #include <sys/sockio.h>
  40 #include <sys/mbuf.h>
  41 #include <sys/errno.h>
  42 #include <sys/queue.h>
  43 #include <sys/syslog.h>
  44 #include <sys/protosw.h>
  45
  46 #include <sys/malloc.h>
  47
  48 #include <net/if.h>
  49 #include <net/route.h>
  50
  51 #include <netinet/in.h>
  52 #include <netinet/in_systm.h>
  53 #ifdef INET
  54 #include <netinet/ip.h>
  55 #endif
  56 #include <netinet/ip_encap.h>
  57 #ifdef INET6
  58 #include <netinet/ip6.h>
  59 #include <netinet6/ip6_var.h>
  60 #include <netinet6/in6_gif.h>
  61 #include <netinet6/in6_var.h>
  62 #endif
  63 #include <netinet6/ip6protosw.h>
  64 #include <netinet/ip_ecn.h>
  65 #ifdef INET6
  66 #include <netinet6/ip6_ecn.h>
  67 #endif
  68
  69 #include <net/gif/if_gif.h>
  70
  71 #include <net/net_osdep.h>
  72
  73 #ifdef INET6
  74 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *,
  75                          struct ifnet *);
  76
  77 extern  struct domain inet6domain;
  78 struct protosw in6_gif_protosw =
  79     {
  80         .pr_type = SOCK_RAW,
  81         .pr_domain = &inet6domain,
  82         .pr_protocol = 0 /* IPPROTO_IPV[46] */,
  83         .pr_flags = PR_ATOMIC|PR_ADDR,
  84
  85         .pr_input = in6_gif_input,
  86         .pr_output = rip6_output,
  87         .pr_ctlinput = NULL,
  88         .pr_ctloutput = rip6_ctloutput,
  89
  90         .pr_usrreqs = &rip6_usrreqs
  91     };
  92
  93 /*
  94  * family = family of the packet to be encapsulate.
  95  */
  96 int
  97 in6_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
  98 {
  99         struct gif_softc *sc = (struct gif_softc*)ifp;
 100         struct route_in6 *ro = &sc->gif_ro6[mycpu->gd_cpuid];
 101         struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&ro->ro_dst;
 102         struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc;
 103         struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst;
 104         struct ip6_hdr *ip6;
 105         int proto;
 106         u_int8_t itos, otos;
 107
 108         if (sin6_src == NULL || sin6_dst == NULL ||
 109             sin6_src->sin6_family != AF_INET6 ||
 110             sin6_dst->sin6_family != AF_INET6) {
 111                 m_freem(m);
 112                 return EAFNOSUPPORT;
 113         }
 114
 115         switch (family) {
 116 #ifdef INET
 117         case AF_INET:
 118             {
 119                 struct ip *ip;
 120
 121                 proto = IPPROTO_IPV4;
 122                 if (m->m_len < sizeof(*ip)) {
 123                         m = m_pullup(m, sizeof(*ip));
 124                         if (!m)
 125                                 return ENOBUFS;
 126                 }
 127                 ip = mtod(m, struct ip *);
 128                 itos = ip->ip_tos;
 129                 break;
 130             }
 131 #endif
 132 #ifdef INET6
 133         case AF_INET6:
 134             {
 135                 struct ip6_hdr *ip6;
 136                 proto = IPPROTO_IPV6;
 137                 if (m->m_len < sizeof(*ip6)) {
 138                         m = m_pullup(m, sizeof(*ip6));
 139                         if (!m)
 140                                 return ENOBUFS;
 141                 }
 142                 ip6 = mtod(m, struct ip6_hdr *);
 143                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 144                 break;
 145             }
 146 #endif
 147         default:
 148 #ifdef DEBUG
 149                 kprintf("in6_gif_output: warning: unknown family %d passed\n",
 150                         family);
 151 #endif
 152                 m_freem(m);
 153                 return EAFNOSUPPORT;
 154         }
 155
 156         /* prepend new IP header */
 157         M_PREPEND(m, sizeof(struct ip6_hdr), M_NOWAIT);
 158         if (m && m->m_len < sizeof(struct ip6_hdr))
 159                 m = m_pullup(m, sizeof(struct ip6_hdr));
 160         if (m == NULL) {
 161                 kprintf("ENOBUFS in in6_gif_output %d\n", __LINE__);
 162                 return ENOBUFS;
 163         }
 164
 165         ip6 = mtod(m, struct ip6_hdr *);
 166         ip6->ip6_flow   = 0;
 167         ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 168         ip6->ip6_vfc    |= IPV6_VERSION;
 169         ip6->ip6_plen   = htons((u_short)m->m_pkthdr.len);
 170         ip6->ip6_nxt    = proto;
 171         ip6->ip6_hlim   = ip6_gif_hlim;
 172         ip6->ip6_src    = sin6_src->sin6_addr;
 173         /* bidirectional configured tunnel mode */
 174         if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr))
 175                 ip6->ip6_dst = sin6_dst->sin6_addr;
 176         else  {
 177                 m_freem(m);
 178                 return ENETUNREACH;
 179         }
 180         if (ifp->if_flags & IFF_LINK1)
 181                 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
 182         else
 183                 ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
 184         ip6->ip6_flow &= ~ntohl(0xff00000);
 185         ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
 186
 187         if (dst->sin6_family != sin6_dst->sin6_family ||
 188              !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) {
 189                 /* cache route doesn't match */
 190                 bzero(dst, sizeof(*dst));
 191                 dst->sin6_family = sin6_dst->sin6_family;
 192                 dst->sin6_len = sizeof(struct sockaddr_in6);
 193                 dst->sin6_addr = sin6_dst->sin6_addr;
 194                 if (ro->ro_rt != NULL) {
 195                         RTFREE(ro->ro_rt);
 196                         ro->ro_rt = NULL;
 197                 }
 198 #if 0
 199                 sc->gif_if.if_mtu = GIF_MTU;
 200 #endif
 201         }
 202
 203         if (ro->ro_rt == NULL) {
 204                 rtalloc((struct route *)ro);
 205                 if (ro->ro_rt == NULL) {
 206                         m_freem(m);
 207                         return ENETUNREACH;
 208                 }
 209
 210                 /* if it constitutes infinite encapsulation, punt. */
 211                 if (ro->ro_rt->rt_ifp == ifp) {
 212                         m_freem(m);
 213                         return ENETUNREACH;     /*XXX*/
 214                 }
 215 #if 0
 216                 ifp->if_mtu = ro->ro_rt->rt_ifp->if_mtu -
 217                               sizeof(struct ip6_hdr);
 218 #endif
 219         }
 220
 221 #ifdef IPV6_MINMTU
 222         /*
 223          * force fragmentation to minimum MTU, to avoid path MTU discovery.
 224          * it is too painful to ask for resend of inner packet, to achieve
 225          * path MTU discovery for encapsulated packets.
 226          */
 227         return (ip6_output(m, 0, ro, IPV6_MINMTU, 0, NULL, NULL));
 228 #else
 229         return (ip6_output(m, 0, ro, 0, 0, NULL, NULL));
 230 #endif
 231 }
 232
 233 int
 234 in6_gif_input(struct mbuf **mp, int *offp, int proto)
 235 {
 236         struct mbuf *m = *mp;
 237         struct ifnet *gifp = NULL;
 238         struct ip6_hdr *ip6;
 239         int af = 0;
 240         u_int32_t otos;
 241
 242         ip6 = mtod(m, struct ip6_hdr *);
 243
 244         gifp = (struct ifnet *)encap_getarg(m);
 245
 246         if (gifp == NULL || !(gifp->if_flags & IFF_UP)) {
 247                 m_freem(m);
 248                 ip6stat.ip6s_nogif++;
 249                 return IPPROTO_DONE;
 250         }
 251
 252         otos = ip6->ip6_flow;
 253         m_adj(m, *offp);
 254
 255         switch (proto) {
 256 #ifdef INET
 257         case IPPROTO_IPV4:
 258             {
 259                 struct ip *ip;
 260                 u_int8_t otos8;
 261                 af = AF_INET;
 262                 otos8 = (ntohl(otos) >> 20) & 0xff;
 263                 if (m->m_len < sizeof(*ip)) {
 264                         m = m_pullup(m, sizeof(*ip));
 265                         if (!m)
 266                                 return IPPROTO_DONE;
 267                 }
 268                 ip = mtod(m, struct ip *);
 269                 if (gifp->if_flags & IFF_LINK1)
 270                         ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
 271                 else
 272                         ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
 273                 break;
 274             }
 275 #endif /* INET */
 276 #ifdef INET6
 277         case IPPROTO_IPV6:
 278             {
 279                 struct ip6_hdr *ip6;
 280                 af = AF_INET6;
 281                 if (m->m_len < sizeof(*ip6)) {
 282                         m = m_pullup(m, sizeof(*ip6));
 283                         if (!m)
 284                                 return IPPROTO_DONE;
 285                 }
 286                 ip6 = mtod(m, struct ip6_hdr *);
 287                 if (gifp->if_flags & IFF_LINK1)
 288                         ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow);
 289                 else
 290                         ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
 291                 break;
 292             }
 293 #endif
 294         default:
 295                 ip6stat.ip6s_nogif++;
 296                 m_freem(m);
 297                 return IPPROTO_DONE;
 298         }
 299
 300         gif_input(m, af, gifp);
 301         return IPPROTO_DONE;
 302 }
 303
 304 /*
 305  * validate outer address.
 306  */
 307 static int
 308 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc,
 309               struct ifnet *ifp)
 310 {
 311         struct sockaddr_in6 *src, *dst;
 312
 313         src = (struct sockaddr_in6 *)sc->gif_psrc;
 314         dst = (struct sockaddr_in6 *)sc->gif_pdst;
 315
 316         /*
 317          * Check for address match.  Note that the check is for an incoming
 318          * packet.  We should compare the *source* address in our configuration
 319          * and the *destination* address of the packet, and vice versa.
 320          */
 321         if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
 322             !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src))
 323                 return 0;
 324
 325         /* martian filters on outer source - done in ip6_input */
 326
 327         /* ingress filters on outer source */
 328         if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp) {
 329                 struct sockaddr_in6 sin6;
 330                 struct rtentry *rt;
 331
 332                 bzero(&sin6, sizeof(sin6));
 333                 sin6.sin6_family = AF_INET6;
 334                 sin6.sin6_len = sizeof(struct sockaddr_in6);
 335                 sin6.sin6_addr = ip6->ip6_src;
 336                 sin6.sin6_scope_id = 0; /* XXX */
 337
 338                 rt = rtpurelookup((struct sockaddr *)&sin6);
 339                 if (rt != NULL)
 340                         --rt->rt_refcnt;
 341                 if (rt == NULL || rt->rt_ifp != ifp) {
 342 #if 0
 343                         log(LOG_WARNING, "%s: packet from %s dropped "
 344                             "due to ingress filter\n", if_name(&sc->gif_if),
 345                             ip6_sprintf(&sin6.sin6_addr));
 346 #endif
 347                         return 0;
 348                 }
 349         }
 350
 351         return 128 * 2;
 352 }
 353
 354 /*
 355  * we know that we are in IFF_UP, outer address available, and outer family
 356  * matched the physical addr family.  see gif_encapcheck().
 357  * sanity check for arg should have been done in the caller.
 358  */
 359 int
 360 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg)
 361 {
 362         struct ip6_hdr ip6;
 363         struct gif_softc *sc;
 364         struct ifnet *ifp;
 365
 366         /* sanity check done in caller */
 367         sc = (struct gif_softc *)arg;
 368
 369         m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6);
 370         ifp = (m->m_flags & M_PKTHDR) ? m->m_pkthdr.rcvif : NULL;
 371
 372         return gif_validate6(&ip6, sc, ifp);
 373 }
 374
 375 int
 376 in6_gif_attach(struct gif_softc *sc)
 377 {
 378         sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
 379             &in6_gif_protosw, sc);
 380         if (sc->encap_cookie6 == NULL)
 381                 return EEXIST;
 382         return 0;
 383 }
 384
 385 int
 386 in6_gif_detach(struct gif_softc *sc)
 387 {
 388         int error;
 389
 390         error = encap_detach(sc->encap_cookie6);
 391         if (error == 0)
 392                 sc->encap_cookie6 = NULL;
 393         return error;
 394 }
 395
 396 #endif /* INET6 */