sys/netinet6/dest6.c

   1 /*      $NetBSD: dest6.c,v 1.16 2008/04/08 23:37:43 thorpej Exp $       */
   2 /*      $KAME: dest6.c,v 1.25 2001/02/22 01:39:16 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: dest6.c,v 1.16 2008/04/08 23:37:43 thorpej Exp $");
  35
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/malloc.h>
  39 #include <sys/mbuf.h>
  40 #include <sys/domain.h>
  41 #include <sys/protosw.h>
  42 #include <sys/socket.h>
  43 #include <sys/errno.h>
  44 #include <sys/time.h>
  45 #include <sys/kernel.h>
  46
  47 #include <net/if.h>
  48 #include <net/route.h>
  49
  50 #include <netinet/in.h>
  51 #include <netinet/in_var.h>
  52 #include <netinet/ip6.h>
  53 #include <netinet6/ip6_var.h>
  54 #include <netinet6/ip6_private.h>
  55 #include <netinet/icmp6.h>
  56
  57 /*
  58  * Destination options header processing.
  59  */
  60 int
  61 dest6_input(struct mbuf **mp, int *offp, int proto)
  62 {
  63         struct mbuf *m = *mp;
  64         int off = *offp, dstoptlen, optlen;
  65         struct ip6_dest *dstopts;
  66         u_int8_t *opt;
  67
  68         /* validation of the length of the header */
  69         IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
  70         if (dstopts == NULL)
  71                 return IPPROTO_DONE;
  72         dstoptlen = (dstopts->ip6d_len + 1) << 3;
  73
  74         IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
  75         if (dstopts == NULL)
  76                 return IPPROTO_DONE;
  77         off += dstoptlen;
  78         dstoptlen -= sizeof(struct ip6_dest);
  79         opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
  80
  81         /* search header for all options. */
  82         for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
  83                 if (*opt != IP6OPT_PAD1 &&
  84                     (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
  85                         IP6_STATINC(IP6_STAT_TOOSMALL);
  86                         goto bad;
  87                 }
  88
  89                 switch (*opt) {
  90                 case IP6OPT_PAD1:
  91                         optlen = 1;
  92                         break;
  93                 case IP6OPT_PADN:
  94                         optlen = *(opt + 1) + 2;
  95                         break;
  96                 default:                /* unknown option */
  97                         optlen = ip6_unknown_opt(opt, m,
  98                             opt - mtod(m, u_int8_t *));
  99                         if (optlen == -1)
 100                                 return (IPPROTO_DONE);
 101                         optlen += 2;
 102                         break;
 103                 }
 104         }
 105
 106         *offp = off;
 107         return (dstopts->ip6d_nxt);
 108
 109   bad:
 110         m_freem(m);
 111         return (IPPROTO_DONE);
 112 }