xref: /freebsd/sys/netinet6/dest6.c (revision 23f282aa31e9b6fceacd449020e936e98d6f2298)
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  * $FreeBSD$
30  */
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/mbuf.h>
35 #include <sys/domain.h>
36 #include <sys/protosw.h>
37 #include <sys/socket.h>
38 #include <sys/errno.h>
39 #include <sys/time.h>
40 
41 #include <net/if.h>
42 #include <net/route.h>
43 
44 #include <netinet/in.h>
45 #include <netinet/in_var.h>
46 #include <netinet6/ip6.h>
47 #include <netinet6/ip6_var.h>
48 #include <netinet6/icmp6.h>
49 
50 /*
51  * Destination options header processing.
52  */
53 int
54 dest6_input(mp, offp, proto)
55 	struct mbuf **mp;
56 	int *offp, proto;
57 {
58 	register struct mbuf *m = *mp;
59 	int off = *offp, dstoptlen, optlen;
60 	struct ip6_dest *dstopts;
61 	u_int8_t *opt;
62 
63 	/* validation of the length of the header */
64 	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
65 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
66 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
67 
68 	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
69 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
70 	off += dstoptlen;
71 	dstoptlen -= sizeof(struct ip6_dest);
72 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
73 
74 	/* search header for all options. */
75 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
76 		switch(*opt) {
77 		 case IP6OPT_PAD1:
78 			 optlen = 1;
79 			 break;
80 		 case IP6OPT_PADN:
81 			 if (dstoptlen < IP6OPT_MINLEN) {
82 				 ip6stat.ip6s_toosmall++;
83 				 goto bad;
84 			 }
85 			 optlen = *(opt + 1) + 2;
86 			 break;
87 		 default:		/* unknown option */
88 			 if (dstoptlen < IP6OPT_MINLEN) {
89 				 ip6stat.ip6s_toosmall++;
90 				 goto bad;
91 			 }
92 			 if ((optlen = ip6_unknown_opt(opt, m,
93 						       opt-mtod(m, u_int8_t *))) == -1)
94 				 return(IPPROTO_DONE);
95 			 optlen += 2;
96 			 break;
97 		}
98 	}
99 
100 	*offp = off;
101 	return(dstopts->ip6d_nxt);
102 
103   bad:
104 	m_freem(m);
105 	return(IPPROTO_DONE);
106 }
107