xref: /netbsd-src/sys/netinet6/dest6.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: dest6.c,v 1.15 2006/11/16 01:33:45 christos 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/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: dest6.c,v 1.15 2006/11/16 01:33:45 christos Exp $");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/malloc.h>
39 #include <sys/mbuf.h>
40 #include <sys/domain.h>
41 #include <sys/protosw.h>
42 #include <sys/socket.h>
43 #include <sys/errno.h>
44 #include <sys/time.h>
45 #include <sys/kernel.h>
46 
47 #include <net/if.h>
48 #include <net/route.h>
49 
50 #include <netinet/in.h>
51 #include <netinet/in_var.h>
52 #include <netinet/ip6.h>
53 #include <netinet6/ip6_var.h>
54 #include <netinet/icmp6.h>
55 
56 /*
57  * Destination options header processing.
58  */
59 int
60 dest6_input(struct mbuf **mp, int *offp, int 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 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
69 	if (dstopts == NULL)
70 		return IPPROTO_DONE;
71 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
72 
73 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
74 	if (dstopts == NULL)
75 		return IPPROTO_DONE;
76 	off += dstoptlen;
77 	dstoptlen -= sizeof(struct ip6_dest);
78 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
79 
80 	/* search header for all options. */
81 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
82 		if (*opt != IP6OPT_PAD1 &&
83 		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
84 			ip6stat.ip6s_toosmall++;
85 			goto bad;
86 		}
87 
88 		switch (*opt) {
89 		case IP6OPT_PAD1:
90 			optlen = 1;
91 			break;
92 		case IP6OPT_PADN:
93 			optlen = *(opt + 1) + 2;
94 			break;
95 		default:		/* unknown option */
96 			optlen = ip6_unknown_opt(opt, m,
97 			    opt - mtod(m, u_int8_t *));
98 			if (optlen == -1)
99 				return (IPPROTO_DONE);
100 			optlen += 2;
101 			break;
102 		}
103 	}
104 
105 	*offp = off;
106 	return (dstopts->ip6d_nxt);
107 
108   bad:
109 	m_freem(m);
110 	return (IPPROTO_DONE);
111 }
112