dest6.c revision 330897 
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__FBSDID("$FreeBSD: stable/11/sys/netinet6/dest6.c 330897 2018-03-14 03:19:51Z eadler $");
36
37#include "opt_inet.h"
38#include "opt_inet6.h"
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/malloc.h>
43#include <sys/mbuf.h>
44#include <sys/domain.h>
45#include <sys/protosw.h>
46#include <sys/socket.h>
47#include <sys/errno.h>
48#include <sys/time.h>
49#include <sys/kernel.h>
50
51#include <net/if.h>
52#include <net/if_var.h>
53#include <net/route.h>
54
55#include <netinet/in.h>
56#include <netinet/in_var.h>
57#include <netinet/ip6.h>
58#include <netinet6/ip6_var.h>
59#include <netinet/icmp6.h>
60
61/*
62 * Destination options header processing.
63 */
64int
65dest6_input(struct mbuf **mp, int *offp, int proto)
66{
67	struct mbuf *m = *mp;
68	int off = *offp, dstoptlen, optlen;
69	struct ip6_dest *dstopts;
70	u_int8_t *opt;
71
72	/* validation of the length of the header */
73#ifndef PULLDOWN_TEST
74	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
75	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
76#else
77	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
78	if (dstopts == NULL)
79		return IPPROTO_DONE;
80#endif
81	dstoptlen = (dstopts->ip6d_len + 1) << 3;
82
83#ifndef PULLDOWN_TEST
84	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
85	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
86#else
87	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
88	if (dstopts == NULL)
89		return IPPROTO_DONE;
90#endif
91	off += dstoptlen;
92	dstoptlen -= sizeof(struct ip6_dest);
93	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
94
95	/* search header for all options. */
96	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
97		if (*opt != IP6OPT_PAD1 &&
98		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
99			IP6STAT_INC(ip6s_toosmall);
100			goto bad;
101		}
102
103		switch (*opt) {
104		case IP6OPT_PAD1:
105			optlen = 1;
106			break;
107		case IP6OPT_PADN:
108			optlen = *(opt + 1) + 2;
109			break;
110		default:		/* unknown option */
111			optlen = ip6_unknown_opt(opt, m,
112			    opt - mtod(m, u_int8_t *));
113			if (optlen == -1)
114				return (IPPROTO_DONE);
115			optlen += 2;
116			break;
117		}
118	}
119
120	*offp = off;
121	return (dstopts->ip6d_nxt);
122
123  bad:
124	m_freem(m);
125	return (IPPROTO_DONE);
126}
127