xref: /freebsd/sys/netinet6/dest6.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /*	$FreeBSD$	*/
2 /*	$KAME: dest6.c,v 1.12 2000/05/05 11:00:57 sumikawa 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/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 
45 #include <net/if.h>
46 #include <net/route.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 <netinet/icmp6.h>
53 
54 /*
55  * Destination options header processing.
56  */
57 int
58 dest6_input(mp, offp, proto)
59 	struct mbuf **mp;
60 	int *offp, proto;
61 {
62 	register struct mbuf *m = *mp;
63 	int off = *offp, dstoptlen, optlen;
64 	struct ip6_dest *dstopts;
65 	u_int8_t *opt;
66 
67 	/* validation of the length of the header */
68 #ifndef PULLDOWN_TEST
69 	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
70 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
71 #else
72 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
73 	if (dstopts == NULL)
74 		return IPPROTO_DONE;
75 #endif
76 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
77 
78 #ifndef PULLDOWN_TEST
79 	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
80 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
81 #else
82 	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
83 	if (dstopts == NULL)
84 		return IPPROTO_DONE;
85 #endif
86 	off += dstoptlen;
87 	dstoptlen -= sizeof(struct ip6_dest);
88 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
89 
90 	/* search header for all options. */
91 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
92 		switch(*opt) {
93 		 case IP6OPT_PAD1:
94 			 optlen = 1;
95 			 break;
96 		 case IP6OPT_PADN:
97 			 if (dstoptlen < IP6OPT_MINLEN) {
98 				 ip6stat.ip6s_toosmall++;
99 				 goto bad;
100 			 }
101 			 optlen = *(opt + 1) + 2;
102 			 break;
103 		 default:		/* unknown option */
104 			 if (dstoptlen < IP6OPT_MINLEN) {
105 				 ip6stat.ip6s_toosmall++;
106 				 goto bad;
107 			 }
108 			 if ((optlen = ip6_unknown_opt(opt, m,
109 						       opt-mtod(m, u_int8_t *))) == -1)
110 				 return(IPPROTO_DONE);
111 			 optlen += 2;
112 			 break;
113 		}
114 	}
115 
116 	*offp = off;
117 	return(dstopts->ip6d_nxt);
118 
119   bad:
120 	m_freem(m);
121 	return(IPPROTO_DONE);
122 }
123