1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	$KAME: dest6.c,v 1.59 2003/07/11 13:21:16 t-momose Exp $
32 */
33
34#include <sys/cdefs.h>
35#include "opt_inet.h"
36#include "opt_inet6.h"
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/malloc.h>
41#include <sys/mbuf.h>
42#include <sys/domain.h>
43#include <sys/protosw.h>
44#include <sys/socket.h>
45#include <sys/errno.h>
46#include <sys/time.h>
47#include <sys/kernel.h>
48
49#include <net/if.h>
50#include <net/if_var.h>
51#include <net/route.h>
52
53#include <netinet/in.h>
54#include <netinet/in_var.h>
55#include <netinet/ip6.h>
56#include <netinet6/ip6_var.h>
57#include <netinet/icmp6.h>
58
59/*
60 * Destination options header processing.
61 */
62int
63dest6_input(struct mbuf **mp, int *offp, int proto)
64{
65	struct mbuf *m;
66	int off, dstoptlen, optlen;
67	struct ip6_dest *dstopts;
68	u_int8_t *opt;
69
70	m = *mp;
71	off = *offp;
72
73	/* Validation of the length of the header. */
74	if (m->m_len < off + sizeof(*dstopts)) {
75		m = m_pullup(m, off + sizeof(*dstopts));
76		if (m == NULL) {
77			IP6STAT_INC(ip6s_exthdrtoolong);
78			*mp = m;
79			return (IPPROTO_DONE);
80		}
81	}
82	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
83	dstoptlen = (dstopts->ip6d_len + 1) << 3;
84
85	if (m->m_len < off + dstoptlen) {
86		m = m_pullup(m, off + dstoptlen);
87		if (m == NULL) {
88			IP6STAT_INC(ip6s_exthdrtoolong);
89			*mp = m;
90			return (IPPROTO_DONE);
91		}
92	}
93	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
94	off += dstoptlen;
95	dstoptlen -= sizeof(struct ip6_dest);
96	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
97
98	/* search header for all options. */
99	for (; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
100		if (*opt != IP6OPT_PAD1 &&
101		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
102			IP6STAT_INC(ip6s_toosmall);
103			goto bad;
104		}
105
106		switch (*opt) {
107		case IP6OPT_PAD1:
108			optlen = 1;
109			break;
110		case IP6OPT_PADN:
111			optlen = *(opt + 1) + 2;
112			break;
113		default:		/* unknown option */
114			optlen = ip6_unknown_opt(opt, m,
115			    opt - mtod(m, u_int8_t *));
116			if (optlen == -1) {
117				*mp = NULL;
118				return (IPPROTO_DONE);
119			}
120			optlen += 2;
121			break;
122		}
123	}
124
125	*offp = off;
126	*mp = m;
127	return (dstopts->ip6d_nxt);
128
129  bad:
130	m_freem(m);
131	*mp = NULL;
132	return (IPPROTO_DONE);
133}
134