xref: /openbsd-src/sys/netinet6/dest6.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: dest6.c,v 1.8 2001/02/22 01:40:40 itojun 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/param.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 #include <sys/mbuf.h>
37 #include <sys/domain.h>
38 #include <sys/protosw.h>
39 #include <sys/socket.h>
40 #include <sys/errno.h>
41 #include <sys/time.h>
42 #include <sys/kernel.h>
43 
44 #include <net/if.h>
45 #include <net/route.h>
46 
47 #include <netinet/in.h>
48 #include <netinet/in_var.h>
49 #include <netinet/ip6.h>
50 #include <netinet6/ip6_var.h>
51 #include <netinet/icmp6.h>
52 
53 /*
54  * Destination options header processing.
55  */
56 int
57 dest6_input(mp, offp, proto)
58 	struct mbuf **mp;
59 	int *offp, 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 #ifndef PULLDOWN_TEST
68 	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
69 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
70 #else
71 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
72 	if (dstopts == NULL)
73 		return IPPROTO_DONE;
74 #endif
75 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
76 
77 #ifndef PULLDOWN_TEST
78 	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
79 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
80 #else
81 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
82 	if (dstopts == NULL)
83 		return IPPROTO_DONE;
84 #endif
85 	off += dstoptlen;
86 	dstoptlen -= sizeof(struct ip6_dest);
87 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
88 
89 	/* search header for all options. */
90 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
91 		if (*opt != IP6OPT_PAD1 &&
92 		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
93 			ip6stat.ip6s_toosmall++;
94 			goto bad;
95 		}
96 
97 		switch (*opt) {
98 		case IP6OPT_PAD1:
99 			optlen = 1;
100 			break;
101 		case IP6OPT_PADN:
102 			optlen = *(opt + 1) + 2;
103 			break;
104 		default:		/* unknown option */
105 			if ((optlen = ip6_unknown_opt(opt, m,
106 						      opt-mtod(m, u_int8_t *))) == -1)
107 				return(IPPROTO_DONE);
108 			optlen += 2;
109 			break;
110 		}
111 	}
112 
113 	*offp = off;
114 	return (dstopts->ip6d_nxt);
115 
116   bad:
117 	m_freem(m);
118 	return (IPPROTO_DONE);
119 }
120