1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $KAME: dest6.c,v 1.59 2003/07/11 13:21:16 t-momose Exp $
32 */
33
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/mbuf.h>
41 #include <sys/domain.h>
42 #include <sys/protosw.h>
43 #include <sys/socket.h>
44 #include <sys/errno.h>
45 #include <sys/time.h>
46 #include <sys/kernel.h>
47
48 #include <net/if.h>
49 #include <net/if_var.h>
50 #include <net/route.h>
51
52 #include <netinet/in.h>
53 #include <netinet/in_var.h>
54 #include <netinet/ip6.h>
55 #include <netinet6/ip6_var.h>
56 #include <netinet/icmp6.h>
57
58 /*
59 * Destination options header processing.
60 */
61 int
dest6_input(struct mbuf ** mp,int * offp,int proto)62 dest6_input(struct mbuf **mp, int *offp, int proto)
63 {
64 struct mbuf *m;
65 int off, dstoptlen, optlen;
66 struct ip6_dest *dstopts;
67 u_int8_t *opt;
68
69 m = *mp;
70 off = *offp;
71
72 /* Validation of the length of the header. */
73 if (m->m_len < off + sizeof(*dstopts)) {
74 m = m_pullup(m, off + sizeof(*dstopts));
75 if (m == NULL) {
76 IP6STAT_INC(ip6s_exthdrtoolong);
77 *mp = m;
78 return (IPPROTO_DONE);
79 }
80 }
81 dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
82 dstoptlen = (dstopts->ip6d_len + 1) << 3;
83
84 if (m->m_len < off + dstoptlen) {
85 m = m_pullup(m, off + dstoptlen);
86 if (m == NULL) {
87 IP6STAT_INC(ip6s_exthdrtoolong);
88 *mp = m;
89 return (IPPROTO_DONE);
90 }
91 }
92 dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
93 off += dstoptlen;
94 dstoptlen -= sizeof(struct ip6_dest);
95 opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
96
97 /* search header for all options. */
98 for (; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
99 if (*opt != IP6OPT_PAD1 &&
100 (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
101 IP6STAT_INC(ip6s_toosmall);
102 goto bad;
103 }
104
105 switch (*opt) {
106 case IP6OPT_PAD1:
107 optlen = 1;
108 break;
109 case IP6OPT_PADN:
110 optlen = *(opt + 1) + 2;
111 break;
112 default: /* unknown option */
113 optlen = ip6_unknown_opt(opt, m,
114 opt - mtod(m, u_int8_t *));
115 if (optlen == -1) {
116 *mp = NULL;
117 return (IPPROTO_DONE);
118 }
119 optlen += 2;
120 break;
121 }
122 }
123
124 *offp = off;
125 *mp = m;
126 return (dstopts->ip6d_nxt);
127
128 bad:
129 m_freem(m);
130 *mp = NULL;
131 return (IPPROTO_DONE);
132 }
133