xref: /dragonfly/sys/netinet6/dest6.c (revision 36a3d1d6)
1 /*	$FreeBSD: src/sys/netinet6/dest6.c,v 1.1.2.4 2002/04/28 05:40:26 suz Exp $	*/
2 /*	$DragonFly: src/sys/netinet6/dest6.c,v 1.4 2006/10/24 06:18:42 hsu Exp $	*/
3 /*	$KAME: dest6.c,v 1.34 2002/01/08 02:40:55 k-sugyou Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/domain.h>
42 #include <sys/protosw.h>
43 #include <sys/socket.h>
44 #include <sys/errno.h>
45 #include <sys/time.h>
46 #include <sys/kernel.h>
47 
48 #include <net/if.h>
49 #include <net/route.h>
50 
51 #include <netinet/in.h>
52 #include <netinet/in_var.h>
53 #include <netinet/ip6.h>
54 #include <netinet6/ip6_var.h>
55 #include <netinet/icmp6.h>
56 
57 /*
58  * Destination options header processing.
59  */
60 int
61 dest6_input(struct mbuf **mp, int *offp, int proto)
62 {
63 	struct mbuf *m = *mp;
64 	int off = *offp, dstoptlen, optlen;
65 	struct ip6_dest *dstopts;
66 	u_int8_t *opt;
67 	struct ip6_hdr *ip6;
68 
69 	ip6 = mtod(m, struct ip6_hdr *);
70 
71 	/* validation of the length of the header */
72 #ifndef PULLDOWN_TEST
73 	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
74 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
75 #else
76 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
77 	if (dstopts == NULL)
78 		return IPPROTO_DONE;
79 #endif
80 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
81 
82 #ifndef PULLDOWN_TEST
83 	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
84 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
85 #else
86 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
87 	if (dstopts == NULL)
88 		return IPPROTO_DONE;
89 #endif
90 	off += dstoptlen;
91 	dstoptlen -= sizeof(struct ip6_dest);
92 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
93 
94 	/* search header for all options. */
95 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
96 		if (*opt != IP6OPT_PAD1 &&
97 		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
98 			ip6stat.ip6s_toosmall++;
99 			goto bad;
100 		}
101 
102 		switch (*opt) {
103 		case IP6OPT_PAD1:
104 			optlen = 1;
105 			break;
106 		case IP6OPT_PADN:
107 			optlen = *(opt + 1) + 2;
108 			break;
109 
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