bsd/netinet6/dest6.c

   1 /*      $FreeBSD: src/sys/netinet6/dest6.c,v 1.1.2.3 2001/07/03 11:01:49 ume Exp $      */
   2 /*      $KAME: dest6.c,v 1.27 2001/03/29 05:34:30 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/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/malloc.h>
  36 #include <sys/mbuf.h>
  37 #include <sys/domain.h>
  38 #include <sys/protosw.h>
  39 #include <sys/socket.h>
  40 #include <sys/errno.h>
  41 #include <sys/time.h>
  42 #include <sys/kernel.h>
  43
  44 #include <net/if.h>
  45 #include <net/route.h>
  46
  47 #include <netinet/in.h>
  48 #include <netinet/in_var.h>
  49 #include <netinet/ip6.h>
  50 #include <netinet6/ip6_var.h>
  51 #include <netinet/icmp6.h>
  52
  53 /*
  54  * Destination options header processing.
  55  */
  56 int
  57 dest6_input(struct mbuf **mp, int *offp, int proto)
  58 {
  59 #pragma unused(proto)
  60         struct mbuf *m = *mp;
  61         int off = *offp, dstoptlen, optlen;
  62         struct ip6_dest *dstopts;
  63         u_int8_t *opt;
  64
  65         /* validation of the length of the header */
  66 #ifndef PULLDOWN_TEST
  67         IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), return IPPROTO_DONE);
  68         dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
  69 #else
  70         IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
  71         if (dstopts == NULL)
  72                 return IPPROTO_DONE;
  73 #endif
  74         dstoptlen = (dstopts->ip6d_len + 1) << 3;
  75
  76 #ifndef PULLDOWN_TEST
  77         IP6_EXTHDR_CHECK(m, off, dstoptlen, return IPPROTO_DONE);
  78         dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
  79 #else
  80         IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
  81         if (dstopts == NULL)
  82                 return IPPROTO_DONE;
  83 #endif
  84         off += dstoptlen;
  85         dstoptlen -= sizeof(struct ip6_dest);
  86         opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
  87
  88         /* search header for all options. */
  89         for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
  90                 if (*opt != IP6OPT_PAD1 &&
  91                     (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
  92                         ip6stat.ip6s_toosmall++;
  93                         goto bad;
  94                 }
  95
  96                 switch (*opt) {
  97                 case IP6OPT_PAD1:
  98                         optlen = 1;
  99                         break;
 100                 case IP6OPT_PADN:
 101                         optlen = *(opt + 1) + 2;
 102                         break;
 103
 104                 default:                /* unknown option */
 105                         optlen = ip6_unknown_opt(opt, m,
 106                             opt - mtod(m, u_int8_t *));
 107                         if (optlen == -1)
 108                                 return (IPPROTO_DONE);
 109                         optlen += 2;
 110                         break;
 111                 }
 112         }
 113
 114         *offp = off;
 115         return (dstopts->ip6d_nxt);
 116
 117   bad:
 118         m_freem(m);
 119         return (IPPROTO_DONE);
 120 }