xref: /freebsd/sys/netinet6/dest6.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
1 /*	$FreeBSD$	*/
2 /*	$KAME: dest6.c,v 1.59 2003/07/11 13:21:16 t-momose 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 "opt_inet.h"
34 #include "opt_inet6.h"
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(mp, offp, proto)
61 	struct mbuf **mp;
62 	int *offp, proto;
63 {
64 	struct mbuf *m = *mp;
65 	int off = *offp, dstoptlen, optlen;
66 	struct ip6_dest *dstopts;
67 	u_int8_t *opt;
68 
69 	/* validation of the length of the header */
70 #ifndef PULLDOWN_TEST
71 	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
72 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
73 #else
74 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
75 	if (dstopts == NULL)
76 		return IPPROTO_DONE;
77 #endif
78 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
79 
80 #ifndef PULLDOWN_TEST
81 	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
82 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
83 #else
84 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
85 	if (dstopts == NULL)
86 		return IPPROTO_DONE;
87 #endif
88 	off += dstoptlen;
89 	dstoptlen -= sizeof(struct ip6_dest);
90 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
91 
92 	/* search header for all options. */
93 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
94 		if (*opt != IP6OPT_PAD1 &&
95 		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
96 			ip6stat.ip6s_toosmall++;
97 			goto bad;
98 		}
99 
100 		switch (*opt) {
101 		case IP6OPT_PAD1:
102 			optlen = 1;
103 			break;
104 		case IP6OPT_PADN:
105 			optlen = *(opt + 1) + 2;
106 			break;
107 		default:		/* unknown option */
108 			optlen = ip6_unknown_opt(opt, m,
109 			    opt - mtod(m, u_int8_t *));
110 			if (optlen == -1)
111 				return (IPPROTO_DONE);
112 			optlen += 2;
113 			break;
114 		}
115 	}
116 
117 	*offp = off;
118 	return (dstopts->ip6d_nxt);
119 
120   bad:
121 	m_freem(m);
122 	return (IPPROTO_DONE);
123 }
124