xref: /freebsd/sys/netinet6/dest6.c (revision 4a5216a6dc0c3ce4cf5f2d3ee8af0c3ff3402c4f)
1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	$KAME: dest6.c,v 1.59 2003/07/11 13:21:16 t-momose Exp $
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/domain.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/errno.h>
46 #include <sys/time.h>
47 #include <sys/kernel.h>
48 #include <sys/vimage.h>
49 
50 #include <net/if.h>
51 #include <net/route.h>
52 
53 #include <netinet/in.h>
54 #include <netinet/in_var.h>
55 #include <netinet/ip6.h>
56 #include <netinet6/ip6_var.h>
57 #include <netinet/icmp6.h>
58 
59 /*
60  * Destination options header processing.
61  */
62 int
63 dest6_input(struct mbuf **mp, int *offp, int proto)
64 {
65 	INIT_VNET_INET6(curvnet);
66 	struct mbuf *m = *mp;
67 	int off = *offp, dstoptlen, optlen;
68 	struct ip6_dest *dstopts;
69 	u_int8_t *opt;
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 			V_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 		default:		/* unknown option */
110 			optlen = ip6_unknown_opt(opt, m,
111 			    opt - mtod(m, u_int8_t *));
112 			if (optlen == -1)
113 				return (IPPROTO_DONE);
114 			optlen += 2;
115 			break;
116 		}
117 	}
118 
119 	*offp = off;
120 	return (dstopts->ip6d_nxt);
121 
122   bad:
123 	m_freem(m);
124 	return (IPPROTO_DONE);
125 }
126