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dest6.c revision 1.8 
      1 /*	$NetBSD: dest6.c,v 1.8 2001/01/23 05:21:23 itojun Exp $	*/
      2 /*	$KAME: dest6.c,v 1.14 2001/01/23 05:16:28 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/in6_pcb.h>
     51 #include <netinet6/ip6_var.h>
     52 #include <netinet/icmp6.h>
     53 
     54 /*
     55  * Destination options header processing.
     56  */
     57 int
     58 dest6_input(mp, offp, proto)
     59 	struct mbuf **mp;
     60 	int *offp, 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 #ifndef PULLDOWN_TEST
     69 	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
     70 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
     71 #else
     72 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
     73 	if (dstopts == NULL)
     74 		return IPPROTO_DONE;
     75 #endif
     76 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
     77 
     78 #ifndef PULLDOWN_TEST
     79 	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
     80 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
     81 #else
     82 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
     83 	if (dstopts == NULL)
     84 		return IPPROTO_DONE;
     85 #endif
     86 	off += dstoptlen;
     87 	dstoptlen -= sizeof(struct ip6_dest);
     88 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
     89 
     90 	/* search header for all options. */
     91 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
     92 		switch (*opt) {
     93 		case IP6OPT_PAD1:
     94 			optlen = 1;
     95 			break;
     96 		case IP6OPT_PADN:
     97 			if (dstoptlen < IP6OPT_MINLEN) {
     98 				ip6stat.ip6s_toosmall++;
     99 				goto bad;
    100 			}
    101 			optlen = *(opt + 1) + 2;
    102 			break;
    103 		default:		/* unknown option */
    104 			if (dstoptlen < IP6OPT_MINLEN) {
    105 				ip6stat.ip6s_toosmall++;
    106 				goto bad;
    107 			}
    108 			optlen = ip6_unknown_opt(opt, m,
    109 			    opt - mtod(m, u_int8_t *));
    110 			if (optlen == -1)
    111 				return (IPPROTO_DONE);
    112 			optlen += 2;
    113 			break;
    114 		}
    115 	}
    116 
    117 	*offp = off;
    118 	return (dstopts->ip6d_nxt);
    119 
    120   bad:
    121 	m_freem(m);
    122 	return (IPPROTO_DONE);
    123 }
    124