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 <sys/cdefs.h>
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/domain.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/errno.h>
46 #include <sys/time.h>
47 #include <sys/kernel.h>
48
49 #include <net/if.h>
50 #include <net/if_var.h>
51 #include <net/route.h>
52
53 #include <netinet/in.h>
54 #include <netinet/in_var.h>
55 #include <netinet/ip6.h>
56 #include <netinet6/ip6_var.h>
57 #include <netinet/icmp6.h>
58
59 /*
60 * Destination options header processing.
61 */
62 int
dest6_input(struct mbuf ** mp,int * offp,int proto)63 dest6_input(struct mbuf **mp, int *offp, int proto)
64 {
65 struct mbuf *m;
66 int off, dstoptlen, optlen;
67 struct ip6_dest *dstopts;
68 u_int8_t *opt;
69
70 m = *mp;
71 off = *offp;
72
73 /* Validation of the length of the header. */
74 if (m->m_len < off + sizeof(*dstopts)) {
75 m = m_pullup(m, off + sizeof(*dstopts));
76 if (m == NULL) {
77 IP6STAT_INC(ip6s_exthdrtoolong);
78 *mp = m;
79 return (IPPROTO_DONE);
80 }
81 }
82 dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
83 dstoptlen = (dstopts->ip6d_len + 1) << 3;
84
85 if (m->m_len < off + dstoptlen) {
86 m = m_pullup(m, off + dstoptlen);
87 if (m == NULL) {
88 IP6STAT_INC(ip6s_exthdrtoolong);
89 *mp = m;
90 return (IPPROTO_DONE);
91 }
92 }
93 dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
94 off += dstoptlen;
95 dstoptlen -= sizeof(struct ip6_dest);
96 opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
97
98 /* search header for all options. */
99 for (; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
100 if (*opt != IP6OPT_PAD1 &&
101 (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
102 IP6STAT_INC(ip6s_toosmall);
103 goto bad;
104 }
105
106 switch (*opt) {
107 case IP6OPT_PAD1:
108 optlen = 1;
109 break;
110 case IP6OPT_PADN:
111 optlen = *(opt + 1) + 2;
112 break;
113 default: /* unknown option */
114 optlen = ip6_unknown_opt(opt, m,
115 opt - mtod(m, u_int8_t *));
116 if (optlen == -1) {
117 *mp = NULL;
118 return (IPPROTO_DONE);
119 }
120 optlen += 2;
121 break;
122 }
123 }
124
125 *offp = off;
126 *mp = m;
127 return (dstopts->ip6d_nxt);
128
129 bad:
130 m_freem(m);
131 *mp = NULL;
132 return (IPPROTO_DONE);
133 }
134