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dest6.c revision 1.17 
      1 /*	$NetBSD: dest6.c,v 1.17 2008/04/15 03:57:04 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 1.17 2008/04/15 03:57:04 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 }
    113