1/*	$OpenBSD: dest6.c,v 1.20 2024/02/13 12:22:09 bluhm 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/param.h>
34#include <sys/systm.h>
35#include <sys/mbuf.h>
36#include <sys/socket.h>
37#include <sys/errno.h>
38#include <sys/time.h>
39#include <sys/kernel.h>
40
41#include <net/route.h>
42
43#include <netinet/in.h>
44#include <netinet/ip6.h>
45#include <netinet6/ip6_var.h>
46#include <netinet/icmp6.h>
47
48/*
49 * Destination options header processing.
50 */
51int
52dest6_input(struct mbuf **mp, int *offp, int proto, int af)
53{
54	int off = *offp, dstoptlen, optlen;
55	struct ip6_dest *dstopts;
56	u_int8_t *opt;
57
58	/* validation of the length of the header */
59	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, *mp, off, sizeof(*dstopts));
60	if (dstopts == NULL)
61		return IPPROTO_DONE;
62	dstoptlen = (dstopts->ip6d_len + 1) << 3;
63
64	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, *mp, off, dstoptlen);
65	if (dstopts == NULL)
66		return IPPROTO_DONE;
67	off += dstoptlen;
68	dstoptlen -= sizeof(struct ip6_dest);
69	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
70
71	/* search header for all options. */
72	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
73		if (*opt != IP6OPT_PAD1 &&
74		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
75			ip6stat_inc(ip6s_toosmall);
76			goto bad;
77		}
78
79		switch (*opt) {
80		case IP6OPT_PAD1:
81			optlen = 1;
82			break;
83		case IP6OPT_PADN:
84			optlen = *(opt + 1) + 2;
85			break;
86		default:		/* unknown option */
87			optlen = ip6_unknown_opt(mp, opt,
88			    opt - mtod(*mp, u_int8_t *));
89			if (optlen == -1)
90				return (IPPROTO_DONE);
91			optlen += 2;
92			break;
93		}
94	}
95
96	*offp = off;
97	return (dstopts->ip6d_nxt);
98
99  bad:
100	m_freemp(mp);
101	return (IPPROTO_DONE);
102}
103