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/droptap.h>
72 #include <net/if.h>
73 #include <net/route.h>
74
75 #include <netinet/in.h>
76 #include <netinet/in_var.h>
77 #include <netinet/ip6.h>
78 #include <netinet6/ip6_var.h>
79 #include <netinet/icmp6.h>
80
81 /*
82 * Destination options header processing.
83 */
84 int
dest6_input(struct mbuf ** mp,int * offp,int proto)85 dest6_input(struct mbuf **mp, int *offp, int proto)
86 {
87 #pragma unused(proto)
88 struct mbuf *__single m = *mp;
89 int off = *offp, dstoptlen = 0, optlen = 0;
90 struct ip6_dest *dstopts = NULL;
91 u_int8_t *opt = NULL;
92 drop_reason_t drop_reason = DROP_REASON_UNSPECIFIED;
93
94 /* validation of the length of the header */
95 IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), return IPPROTO_DONE);
96 dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
97 dstoptlen = (dstopts->ip6d_len + 1) << 3;
98
99 IP6_EXTHDR_CHECK(m, off, dstoptlen, return IPPROTO_DONE);
100 dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
101 off += dstoptlen;
102 dstoptlen -= sizeof(struct ip6_dest);
103 opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
104
105 /* search header for all options. */
106 for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
107 if (*opt != IP6OPT_PAD1 &&
108 (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
109 ip6stat.ip6s_toosmall++;
110 drop_reason = DROP_REASON_IP_TOO_SMALL;
111 goto bad;
112 }
113
114 switch (*opt) {
115 case IP6OPT_PAD1:
116 optlen = 1;
117 break;
118 case IP6OPT_PADN:
119 optlen = *(opt + 1) + 2;
120 break;
121
122 default: /* unknown option */
123 optlen = ip6_unknown_opt(opt, dstoptlen, m,
124 opt - mtod(m, u_int8_t *));
125 if (optlen == -1) {
126 return IPPROTO_DONE;
127 }
128 optlen += 2;
129 break;
130 }
131 }
132 *mp = m;
133 *offp = off;
134 return dstopts->ip6d_nxt;
135
136 bad:
137 *mp = NULL;
138 m_drop(m, DROPTAP_FLAG_DIR_IN | DROPTAP_FLAG_L2_MISSING, drop_reason, NULL, 0);
139 return IPPROTO_DONE;
140 }
141