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dest6.c revision 1.15 
      1 /*	$NetBSD: dest6.c,v 1.15 2006/11/16 01:33:45 christos 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 1.15 2006/11/16 01:33:45 christos 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 <netinet/icmp6.h>
     55 
     56 /*
     57  * Destination options header processing.
     58  */
     59 int
     60 dest6_input(struct mbuf **mp, int *offp, int proto)
     61 {
     62 	struct mbuf *m = *mp;
     63 	int off = *offp, dstoptlen, optlen;
     64 	struct ip6_dest *dstopts;
     65 	u_int8_t *opt;
     66 
     67 	/* validation of the length of the header */
     68 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
     69 	if (dstopts == NULL)
     70 		return IPPROTO_DONE;
     71 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
     72 
     73 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
     74 	if (dstopts == NULL)
     75 		return IPPROTO_DONE;
     76 	off += dstoptlen;
     77 	dstoptlen -= sizeof(struct ip6_dest);
     78 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
     79 
     80 	/* search header for all options. */
     81 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
     82 		if (*opt != IP6OPT_PAD1 &&
     83 		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
     84 			ip6stat.ip6s_toosmall++;
     85 			goto bad;
     86 		}
     87 
     88 		switch (*opt) {
     89 		case IP6OPT_PAD1:
     90 			optlen = 1;
     91 			break;
     92 		case IP6OPT_PADN:
     93 			optlen = *(opt + 1) + 2;
     94 			break;
     95 		default:		/* unknown option */
     96 			optlen = ip6_unknown_opt(opt, m,
     97 			    opt - mtod(m, u_int8_t *));
     98 			if (optlen == -1)
     99 				return (IPPROTO_DONE);
    100 			optlen += 2;
    101 			break;
    102 		}
    103 	}
    104 
    105 	*offp = off;
    106 	return (dstopts->ip6d_nxt);
    107 
    108   bad:
    109 	m_freem(m);
    110 	return (IPPROTO_DONE);
    111 }
    112