bsd/netinet6/route6.c

   1 /*      $KAME: route6.c,v 1.10 2000/02/22 14:04:34 itojun Exp $ */
   2
   3 /*
   4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/param.h>
  33 #include <sys/mbuf.h>
  34 #include <sys/socket.h>
  35
  36 #include <net/if.h>
  37
  38 #include <netinet/in.h>
  39 #include <netinet6/in6_var.h>
  40 #include <netinet/ip6.h>
  41 #include <netinet6/ip6_var.h>
  42
  43 #include <netinet/icmp6.h>
  44
  45 #if MIP6
  46 #include <netinet6/mip6.h>
  47 #include <net/if_types.h>
  48 #endif
  49
  50 static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *,
  51     struct ip6_rthdr0 *));
  52
  53
  54 int
  55 route6_input(mp, offp, proto)
  56         struct mbuf **mp;
  57         int *offp, proto;       /* proto is unused */
  58 {
  59         register struct ip6_hdr *ip6;
  60         register struct mbuf *m = *mp;
  61         register struct ip6_rthdr *rh;
  62         int off = *offp, rhlen;
  63
  64 #ifndef PULLDOWN_TEST
  65         IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE);
  66         ip6 = mtod(m, struct ip6_hdr *);
  67         rh = (struct ip6_rthdr *)((caddr_t)ip6 + off);
  68 #else
  69         ip6 = mtod(m, struct ip6_hdr *);
  70         IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh));
  71         if (rh == NULL) {
  72                 ip6stat.ip6s_tooshort++;
  73                 return IPPROTO_DONE;
  74         }
  75 #endif
  76
  77         switch(rh->ip6r_type) {
  78          case IPV6_RTHDR_TYPE_0:
  79                  rhlen = (rh->ip6r_len + 1) << 3;
  80 #ifndef PULLDOWN_TEST
  81                  IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE);
  82 #else
  83                  IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
  84                  if (rh == NULL) {
  85                         ip6stat.ip6s_tooshort++;
  86                         return IPPROTO_DONE;
  87                  }
  88 #endif
  89                  if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
  90                          return(IPPROTO_DONE);
  91                  break;
  92          default:
  93                  /* unknown routing type */
  94                  if (rh->ip6r_segleft == 0) {
  95                          rhlen = (rh->ip6r_len + 1) << 3;
  96                          break; /* Final dst. Just ignore the header. */
  97                  }
  98                  ip6stat.ip6s_badoptions++;
  99                  icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
 100                              (caddr_t)&rh->ip6r_type - (caddr_t)ip6);
 101                  return(IPPROTO_DONE);
 102         }
 103
 104         *offp += rhlen;
 105         return(rh->ip6r_nxt);
 106 }
 107
 108 /*
 109  * Type0 routing header processing
 110  */
 111 static int
 112 ip6_rthdr0(m, ip6, rh0)
 113         struct mbuf *m;
 114         struct ip6_hdr *ip6;
 115         struct ip6_rthdr0 *rh0;
 116 {
 117         int addrs, index;
 118         struct in6_addr *nextaddr, tmpaddr;
 119
 120         if (rh0->ip6r0_segleft == 0)
 121                 return(0);
 122
 123         if (rh0->ip6r0_len % 2
 124 #if COMPAT_RFC1883
 125             || rh0->ip6r0_len > 46
 126 #endif
 127                 ) {
 128                 /*
 129                  * Type 0 routing header can't contain more than 23 addresses.
 130                  * RFC 2462: this limitation was removed since stict/loose
 131                  * bitmap field was deleted.
 132                  */
 133                 ip6stat.ip6s_badoptions++;
 134                 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
 135                             (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6);
 136                 return(-1);
 137         }
 138
 139         if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
 140                 ip6stat.ip6s_badoptions++;
 141                 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
 142                             (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6);
 143                 return(-1);
 144         }
 145
 146         index = addrs - rh0->ip6r0_segleft;
 147         rh0->ip6r0_segleft--;
 148         nextaddr = ((struct in6_addr *)(rh0 + 1)) + index;
 149
 150         /*
 151          * reject invalid addresses.  be proactive about malicious use of
 152          * IPv4 mapped/compat address.
 153          * XXX need more checks?
 154          */
 155         if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
 156             IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
 157             IN6_IS_ADDR_V4MAPPED(nextaddr) ||
 158             IN6_IS_ADDR_V4COMPAT(nextaddr)) {
 159                 ip6stat.ip6s_badoptions++;
 160                 m_freem(m);
 161                 return(-1);
 162         }
 163         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
 164             IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
 165             IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
 166             IN6_IS_ADDR_V4COMPAT(nextaddr)) {
 167                 ip6stat.ip6s_badoptions++;
 168                 m_freem(m);
 169                 return(-1);
 170         }
 171
 172         /*
 173          * Swap the IPv6 destination address and nextaddr. Forward the packet.
 174          */
 175         tmpaddr = *nextaddr;
 176         *nextaddr = ip6->ip6_dst;
 177         if (IN6_IS_ADDR_LINKLOCAL(nextaddr))
 178                 nextaddr->s6_addr16[1] = 0;
 179         ip6->ip6_dst = tmpaddr;
 180         if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
 181                 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
 182
 183 #if COMPAT_RFC1883
 184         if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
 185                 ip6_forward(m, IPV6_SRCRT_NEIGHBOR);
 186         else
 187                 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR);
 188 #else
 189         ip6_forward(m, 1);
 190 #endif
 191
 192         return(-1);                     /* m would be freed in ip6_forward() */
 193 }