xref: /netbsd-src/sys/netinet6/dest6.c (revision d909946ca08dceb44d7d0f22ec9488679695d976)
1 /*	$NetBSD: dest6.c,v 1.19 2016/04/26 08:44:45 ozaki-r 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 1.19 2016/04/26 08:44:45 ozaki-r Exp $");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/mbuf.h>
39 #include <sys/domain.h>
40 #include <sys/protosw.h>
41 #include <sys/socket.h>
42 #include <sys/errno.h>
43 #include <sys/time.h>
44 #include <sys/kernel.h>
45 
46 #include <net/if.h>
47 
48 #include <netinet/in.h>
49 #include <netinet/in_var.h>
50 #include <netinet/ip6.h>
51 #include <netinet6/ip6_var.h>
52 #include <netinet6/ip6_private.h>
53 #include <netinet/icmp6.h>
54 
55 /*
56  * Destination options header processing.
57  */
58 int
59 dest6_input(struct mbuf **mp, int *offp, int proto)
60 {
61 	struct mbuf *m = *mp;
62 	int off = *offp, dstoptlen, optlen;
63 	struct ip6_dest *dstopts;
64 	u_int8_t *opt;
65 
66 	/* validation of the length of the header */
67 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
68 	if (dstopts == NULL)
69 		return IPPROTO_DONE;
70 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
71 
72 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
73 	if (dstopts == NULL)
74 		return IPPROTO_DONE;
75 	off += dstoptlen;
76 	dstoptlen -= sizeof(struct ip6_dest);
77 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
78 
79 	/* search header for all options. */
80 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
81 		if (*opt != IP6OPT_PAD1 &&
82 		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
83 			IP6_STATINC(IP6_STAT_TOOSMALL);
84 			goto bad;
85 		}
86 
87 		switch (*opt) {
88 		case IP6OPT_PAD1:
89 			optlen = 1;
90 			break;
91 		case IP6OPT_PADN:
92 			optlen = *(opt + 1) + 2;
93 			break;
94 		default:		/* unknown option */
95 			optlen = ip6_unknown_opt(opt, m,
96 			    opt - mtod(m, u_int8_t *));
97 			if (optlen == -1)
98 				return (IPPROTO_DONE);
99 			optlen += 2;
100 			break;
101 		}
102 	}
103 
104 	*offp = off;
105 	return (dstopts->ip6d_nxt);
106 
107   bad:
108 	m_freem(m);
109 	return (IPPROTO_DONE);
110 }
111