dest6.c revision 331722 
1/*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	$KAME: dest6.c,v 1.59 2003/07/11 13:21:16 t-momose Exp $
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: stable/11/sys/netinet6/dest6.c 331722 2018-03-29 02:50:57Z eadler $");
34
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 = *mp;
66	int off = *offp, dstoptlen, optlen;
67	struct ip6_dest *dstopts;
68	u_int8_t *opt;
69
70	/* validation of the length of the header */
71#ifndef PULLDOWN_TEST
72	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
73	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
74#else
75	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
76	if (dstopts == NULL)
77		return IPPROTO_DONE;
78#endif
79	dstoptlen = (dstopts->ip6d_len + 1) << 3;
80
81#ifndef PULLDOWN_TEST
82	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
83	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
84#else
85	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
86	if (dstopts == NULL)
87		return IPPROTO_DONE;
88#endif
89	off += dstoptlen;
90	dstoptlen -= sizeof(struct ip6_dest);
91	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
92
93	/* search header for all options. */
94	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
95		if (*opt != IP6OPT_PAD1 &&
96		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
97			IP6STAT_INC(ip6s_toosmall);
98			goto bad;
99		}
100
101		switch (*opt) {
102		case IP6OPT_PAD1:
103			optlen = 1;
104			break;
105		case IP6OPT_PADN:
106			optlen = *(opt + 1) + 2;
107			break;
108		default:		/* unknown option */
109			optlen = ip6_unknown_opt(opt, m,
110			    opt - mtod(m, u_int8_t *));
111			if (optlen == -1)
112				return (IPPROTO_DONE);
113			optlen += 2;
114			break;
115		}
116	}
117
118	*offp = off;
119	return (dstopts->ip6d_nxt);
120
121  bad:
122	m_freem(m);
123	return (IPPROTO_DONE);
124}
125