xref: /xnu-10063.121.3/bsd/netinet6/dest6.c (revision 2c2f96dc2b9a4408a43d3150ae9c105355ca3daa)
1 /*
2  * Copyright (c) 2020 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /*	$FreeBSD: src/sys/netinet6/dest6.c,v 1.1.2.3 2001/07/03 11:01:49 ume Exp $	*/
29 /*	$KAME: dest6.c,v 1.27 2001/03/29 05:34:30 itojun Exp $	*/
30 
31 /*
32  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
33  * All rights reserved.
34  *
35  * Redistribution and use in source and binary forms, with or without
36  * modification, are permitted provided that the following conditions
37  * are met:
38  * 1. Redistributions of source code must retain the above copyright
39  *    notice, this list of conditions and the following disclaimer.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *    notice, this list of conditions and the following disclaimer in the
42  *    documentation and/or other materials provided with the distribution.
43  * 3. Neither the name of the project nor the names of its contributors
44  *    may be used to endorse or promote products derived from this software
45  *    without specific prior written permission.
46  *
47  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
48  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
52  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
53  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
55  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
57  * SUCH DAMAGE.
58  */
59 
60 #include <sys/param.h>
61 #include <sys/systm.h>
62 #include <sys/malloc.h>
63 #include <sys/mbuf.h>
64 #include <sys/domain.h>
65 #include <sys/protosw.h>
66 #include <sys/socket.h>
67 #include <sys/errno.h>
68 #include <sys/time.h>
69 #include <sys/kernel.h>
70 
71 #include <net/if.h>
72 #include <net/route.h>
73 
74 #include <netinet/in.h>
75 #include <netinet/in_var.h>
76 #include <netinet/ip6.h>
77 #include <netinet6/ip6_var.h>
78 #include <netinet/icmp6.h>
79 
80 /*
81  * Destination options header processing.
82  */
83 int
dest6_input(struct mbuf ** mp,int * offp,int proto)84 dest6_input(struct mbuf **mp, int *offp, int proto)
85 {
86 #pragma unused(proto)
87 	struct mbuf *m = *mp;
88 	int off = *offp, dstoptlen = 0, optlen = 0;
89 	struct ip6_dest *dstopts = NULL;
90 	u_int8_t *opt = NULL;
91 
92 	/* validation of the length of the header */
93 	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), return IPPROTO_DONE);
94 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
95 	dstoptlen = (dstopts->ip6d_len + 1) << 3;
96 
97 	IP6_EXTHDR_CHECK(m, off, dstoptlen, return IPPROTO_DONE);
98 	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
99 	off += dstoptlen;
100 	dstoptlen -= sizeof(struct ip6_dest);
101 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
102 
103 	/* search header for all options. */
104 	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
105 		if (*opt != IP6OPT_PAD1 &&
106 		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
107 			ip6stat.ip6s_toosmall++;
108 			goto bad;
109 		}
110 
111 		switch (*opt) {
112 		case IP6OPT_PAD1:
113 			optlen = 1;
114 			break;
115 		case IP6OPT_PADN:
116 			optlen = *(opt + 1) + 2;
117 			break;
118 
119 		default:                /* unknown option */
120 			optlen = ip6_unknown_opt(opt, m,
121 			    opt - mtod(m, u_int8_t *));
122 			if (optlen == -1) {
123 				return IPPROTO_DONE;
124 			}
125 			optlen += 2;
126 			break;
127 		}
128 	}
129 	*mp = m;
130 	*offp = off;
131 	return dstopts->ip6d_nxt;
132 
133 bad:
134 	*mp = NULL;
135 	m_freem(m);
136 	return IPPROTO_DONE;
137 }
138