sys/netinet6/route6.c

   1 /*      $NetBSD: route6.c,v 1.22 2008/04/08 23:37:43 thorpej Exp $      */
   2 /*      $KAME: route6.c,v 1.22 2000/12/03 00:54:00 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 <sys/cdefs.h>
  34 __KERNEL_RCSID(0, "$NetBSD: route6.c,v 1.22 2008/04/08 23:37:43 thorpej Exp $");
  35
  36 #include <sys/param.h>
  37 #include <sys/mbuf.h>
  38 #include <sys/socket.h>
  39 #include <sys/systm.h>
  40 #include <sys/queue.h>
  41
  42 #include <net/if.h>
  43
  44 #include <netinet/in.h>
  45 #include <netinet6/in6_var.h>
  46 #include <netinet/ip6.h>
  47 #include <netinet6/ip6_var.h>
  48 #include <netinet6/ip6_private.h>
  49 #include <netinet6/scope6_var.h>
  50
  51 #include <netinet/icmp6.h>
  52
  53 #if 0
  54 static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *, struct ip6_rthdr0 *);
  55 #endif
  56
  57 int
  58 route6_input(struct mbuf **mp, int *offp, int proto)
  59 {
  60         struct ip6_hdr *ip6;
  61         struct mbuf *m = *mp;
  62         struct ip6_rthdr *rh;
  63         int off = *offp, rhlen;
  64
  65         ip6 = mtod(m, struct ip6_hdr *);
  66         IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh));
  67         if (rh == NULL) {
  68                 IP6_STATINC(IP6_STAT_TOOSHORT);
  69                 return IPPROTO_DONE;
  70         }
  71
  72         switch (rh->ip6r_type) {
  73 #if 0
  74         /*
  75          * See http://www.secdev.org/conf/IPv6_RH_security-csw07.pdf
  76          * for why IPV6_RTHDR_TYPE_0 is banned here.
  77          *
  78          * We return ICMPv6 parameter problem so that innocent people
  79          * (not an attacker) would notice about the use of IPV6_RTHDR_TYPE_0.
  80          * Since there's no amplification, and ICMPv6 error will be rate-
  81          * controlled, it shouldn't cause any problem.
  82          * If you are concerned about this, you may want to use the following
  83          * code fragment:
  84          *
  85          * case IPV6_RTHDR_TYPE_0:
  86          *      m_freem(m);
  87          *      return (IPPROTO_DONE);
  88          */
  89         case IPV6_RTHDR_TYPE_0:
  90                 rhlen = (rh->ip6r_len + 1) << 3;
  91                 /*
  92                  * note on option length:
  93                  * maximum rhlen: 2048
  94                  * max mbuf m_pulldown can handle: MCLBYTES == usually 2048
  95                  * so, here we are assuming that m_pulldown can handle
  96                  * rhlen == 2048 case.  this may not be a good thing to
  97                  * assume - we may want to avoid pulling it up altogether.
  98                  */
  99                 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
 100                 if (rh == NULL) {
 101                         IP6_STATINC(IP6_STAT_TOOSHORT);
 102                         return IPPROTO_DONE;
 103                 }
 104                 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
 105                         return (IPPROTO_DONE);
 106                 break;
 107 #endif
 108         default:
 109                 /* unknown routing type */
 110                 if (rh->ip6r_segleft == 0) {
 111                         rhlen = (rh->ip6r_len + 1) << 3;
 112                         break;  /* Final dst. Just ignore the header. */
 113                 }
 114                 IP6_STATINC(IP6_STAT_BADOPTIONS);
 115                 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
 116                             (char *)&rh->ip6r_type - (char *)ip6);
 117                 return (IPPROTO_DONE);
 118         }
 119
 120         *offp += rhlen;
 121         return (rh->ip6r_nxt);
 122 }
 123
 124 #if 0
 125 /*
 126  * Type0 routing header processing
 127  *
 128  * RFC2292 backward compatibility warning: no support for strict/loose bitmap,
 129  * as it was dropped between RFC1883 and RFC2460.
 130  */
 131 static int
 132 ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6,
 133         struct ip6_rthdr0 *rh0)
 134 {
 135         int addrs, index;
 136         struct in6_addr *nextaddr, tmpaddr;
 137         const struct ip6aux *ip6a;
 138
 139         if (rh0->ip6r0_segleft == 0)
 140                 return (0);
 141
 142         if (rh0->ip6r0_len % 2
 143 #ifdef COMPAT_RFC1883
 144             || rh0->ip6r0_len > 46
 145 #endif
 146                 ) {
 147                 /*
 148                  * Type 0 routing header can't contain more than 23 addresses.
 149                  * RFC 2462: this limitation was removed since strict/loose
 150                  * bitmap field was deleted.
 151                  */
 152                 IP6_STATINC(IP6_STAT_BADOPTIONS);
 153                 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
 154                             (char *)&rh0->ip6r0_len - (char *)ip6);
 155                 return (-1);
 156         }
 157
 158         if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
 159                 IP6_STATINC(IP6_STAT_BADOPTIONS);
 160                 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
 161                             (char *)&rh0->ip6r0_segleft - (char *)ip6);
 162                 return (-1);
 163         }
 164
 165         index = addrs - rh0->ip6r0_segleft;
 166         rh0->ip6r0_segleft--;
 167         nextaddr = ((struct in6_addr *)(rh0 + 1)) + index;
 168
 169         /*
 170          * reject invalid addresses.  be proactive about malicious use of
 171          * IPv4 mapped/compat address.
 172          * XXX need more checks?
 173          */
 174         if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
 175             IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
 176             IN6_IS_ADDR_V4MAPPED(nextaddr) ||
 177             IN6_IS_ADDR_V4COMPAT(nextaddr)) {
 178                 p6stat[IP6_STAT_BADOPTIONS]++;
 179                 goto bad;
 180         }
 181         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
 182             IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
 183             IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
 184             IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
 185                 IP6_STATINC(IP6_STAT_BADOPTIONS);
 186                 goto bad;
 187         }
 188
 189         /*
 190          * Determine the scope zone of the next hop, based on the interface
 191          * of the current hop. [RFC4007, Section 9]
 192          * Then disambiguate the scope zone for the next hop (if necessary).
 193          */
 194         if ((ip6a = ip6_getdstifaddr(m)) == NULL)
 195                 goto bad;
 196         if (in6_setzoneid(nextaddr, ip6a->ip6a_scope_id) != 0) {
 197                 IP6_STATINC(IP6_STAT_BADSCOPE);
 198                 goto bad;
 199         }
 200
 201         /*
 202          * Swap the IPv6 destination address and nextaddr. Forward the packet.
 203          */
 204         tmpaddr = *nextaddr;
 205         *nextaddr = ip6->ip6_dst;
 206         in6_clearscope(nextaddr); /* XXX */
 207         ip6->ip6_dst = tmpaddr;
 208
 209 #ifdef COMPAT_RFC1883
 210         if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
 211                 ip6_forward(m, IPV6_SRCRT_NEIGHBOR);
 212         else
 213                 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR);
 214 #else
 215         ip6_forward(m, 1);
 216 #endif
 217
 218         return (-1);                    /* m would be freed in ip6_forward() */
 219
 220   bad:
 221         m_freem(m);
 222         return (-1);
 223 }
 224 #endif