1 /* $OpenBSD: route6.c,v 1.16 2007/05/31 23:17:38 mcbride Exp $ */
2 /* $KAME: route6.c,v 1.22 2000/12/03 00:54:00 itojun Exp $ */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/param.h>
34 #include <sys/mbuf.h>
35 #include <sys/socket.h>
36 #include <sys/systm.h>
37
38 #include <net/if.h>
39
40 #include <netinet/in.h>
41 #include <netinet6/in6_var.h>
42 #include <netinet/ip6.h>
43 #include <netinet6/ip6_var.h>
44
45 #include <netinet/icmp6.h>
46
47 #if 0
48 static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *, struct ip6_rthdr0 *);
49 #endif
50
51 int
52 route6_input(mp, offp, proto)
53 struct mbuf **mp;
54 int *offp, proto; /* proto is unused */
55 {
56 struct ip6_hdr *ip6;
57 struct mbuf *m = *mp;
58 struct ip6_rthdr *rh;
59 int off = *offp, rhlen;
60
61 ip6 = mtod(m, struct ip6_hdr *);
62 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh));
63 if (rh == NULL) {
64 ip6stat.ip6s_tooshort++;
65 return IPPROTO_DONE;
66 }
67
68 switch (rh->ip6r_type) {
69 #if 0
70 /*
71 * See http://www.secdev.org/conf/IPv6_RH_security-csw07.pdf
72 * for why IPV6_RTHDR_TYPE_0 is banned here.
73 *
74 * We return ICMPv6 parameter problem so that innocent people
75 * (not an attacker) would notice about the use of IPV6_RTHDR_TYPE_0.
76 * Since there's no amplification, and ICMPv6 error will be rate-
77 * controlled, it shouldn't cause any problem.
78 * If you are concerned about this, you may want to use the following
79 * code fragment:
80 *
81 * case IPV6_RTHDR_TYPE_0:
82 * m_freem(m);
83 * return (IPPROTO_DONE);
84 */
85 case IPV6_RTHDR_TYPE_0:
86 rhlen = (rh->ip6r_len + 1) << 3;
87 if (rh->ip6r_segleft == 0)
88 break; /* Final dst. Just ignore the header. */
89 /*
90 * note on option length:
91 * maximum rhlen: 2048
92 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048
93 * so, here we are assuming that m_pulldown can handle
94 * rhlen == 2048 case. this may not be a good thing to
95 * assume - we may want to avoid pulling it up altogether.
96 */
97 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
98 if (rh == NULL) {
99 ip6stat.ip6s_tooshort++;
100 return IPPROTO_DONE;
101 }
102 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
103 return (IPPROTO_DONE);
104 break;
105 #endif
106 default:
107 /* unknown routing type */
108 if (rh->ip6r_segleft == 0) {
109 rhlen = (rh->ip6r_len + 1) << 3;
110 break; /* Final dst. Just ignore the header. */
111 }
112 ip6stat.ip6s_badoptions++;
113 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
114 (caddr_t)&rh->ip6r_type - (caddr_t)ip6);
115 return (IPPROTO_DONE);
116 }
117
118 *offp += rhlen;
119 return (rh->ip6r_nxt);
120 }
121
122 #if 0
123 /*
124 * Type0 routing header processing
125 *
126 * RFC2292 backward compatibility warning: no support for strict/loose bitmap,
127 * as it was dropped between RFC1883 and RFC2460.
128 */
129 static int
130 ip6_rthdr0(m, ip6, rh0)
131 struct mbuf *m;
132 struct ip6_hdr *ip6;
133 struct ip6_rthdr0 *rh0;
134 {
135 int addrs, index;
136 struct in6_addr *nextaddr, tmpaddr;
137
138 if (rh0->ip6r0_segleft == 0)
139 return (0);
140
141 if (rh0->ip6r0_len % 2) {
142 /*
143 * Type 0 routing header can't contain more than 23 addresses.
144 * RFC 2460: this limitation was removed since strict/loose
145 * bitmap field was deleted.
146 */
147 ip6stat.ip6s_badoptions++;
148 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
149 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6);
150 return (-1);
151 }
152
153 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
154 ip6stat.ip6s_badoptions++;
155 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
156 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6);
157 return (-1);
158 }
159
160 index = addrs - rh0->ip6r0_segleft;
161 rh0->ip6r0_segleft--;
162 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index;
163
164 /*
165 * reject invalid addresses. be proactive about malicious use of
166 * IPv4 mapped/compat address.
167 * XXX need more checks?
168 */
169 if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
170 IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
171 IN6_IS_ADDR_V4MAPPED(nextaddr) ||
172 IN6_IS_ADDR_V4COMPAT(nextaddr)) {
173 ip6stat.ip6s_badoptions++;
174 goto bad;
175 }
176 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
177 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
178 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
179 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
180 ip6stat.ip6s_badoptions++;
181 goto bad;
182 }
183
184 /*
185 * Swap the IPv6 destination address and nextaddr. Forward the packet.
186 */
187 tmpaddr = *nextaddr;
188 *nextaddr = ip6->ip6_dst;
189 if (IN6_IS_ADDR_LINKLOCAL(nextaddr))
190 nextaddr->s6_addr16[1] = 0;
191 ip6->ip6_dst = tmpaddr;
192 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
193 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
194
195 ip6_forward(m, 1);
196
197 return (-1); /* m would be freed in ip6_forward() */
198
199 bad:
200 m_freem(m);
201 return (-1);
202 }
203 #endif