sys/netinet6/dest6.c

   1 /*      $FreeBSD: src/sys/netinet6/dest6.c,v 1.1.2.4 2002/04/28 05:40:26 suz Exp $      */
   2 /*      $DragonFly: src/sys/netinet6/dest6.c,v 1.4 2006/10/24 06:18:42 hsu Exp $        */
   3 /*      $KAME: dest6.c,v 1.34 2002/01/08 02:40:55 k-sugyou Exp $        */
   4
   5 /*
   6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "opt_inet.h"
  35 #include "opt_inet6.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/malloc.h>
  40 #include <sys/mbuf.h>
  41 #include <sys/domain.h>
  42 #include <sys/protosw.h>
  43 #include <sys/socket.h>
  44 #include <sys/errno.h>
  45 #include <sys/time.h>
  46 #include <sys/kernel.h>
  47
  48 #include <net/if.h>
  49 #include <net/route.h>
  50
  51 #include <netinet/in.h>
  52 #include <netinet/in_var.h>
  53 #include <netinet/ip6.h>
  54 #include <netinet6/ip6_var.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         struct ip6_hdr *ip6;
  68
  69         ip6 = mtod(m, struct ip6_hdr *);
  70
  71         /* validation of the length of the header */
  72 #ifndef PULLDOWN_TEST
  73         IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
  74         dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
  75 #else
  76         IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
  77         if (dstopts == NULL)
  78                 return IPPROTO_DONE;
  79 #endif
  80         dstoptlen = (dstopts->ip6d_len + 1) << 3;
  81
  82 #ifndef PULLDOWN_TEST
  83         IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
  84         dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
  85 #else
  86         IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
  87         if (dstopts == NULL)
  88                 return IPPROTO_DONE;
  89 #endif
  90         off += dstoptlen;
  91         dstoptlen -= sizeof(struct ip6_dest);
  92         opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
  93
  94         /* search header for all options. */
  95         for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
  96                 if (*opt != IP6OPT_PAD1 &&
  97                     (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
  98                         ip6stat.ip6s_toosmall++;
  99                         goto bad;
 100                 }
 101
 102                 switch (*opt) {
 103                 case IP6OPT_PAD1:
 104                         optlen = 1;
 105                         break;
 106                 case IP6OPT_PADN:
 107                         optlen = *(opt + 1) + 2;
 108                         break;
 109
 110                 default:                /* unknown option */
 111                         optlen = ip6_unknown_opt(opt, m,
 112                             opt - mtod(m, u_int8_t *));
 113                         if (optlen == -1)
 114                                 return (IPPROTO_DONE);
 115                         optlen += 2;
 116                         break;
 117                 }
 118         }
 119
 120         *offp = off;
 121         return (dstopts->ip6d_nxt);
 122
 123 bad:
 124         m_freem(m);
 125         return (IPPROTO_DONE);
 126 }