1/* $NetBSD: route6.c,v 1.23 2008/04/15 03:57:04 thorpej 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/cdefs.h>
34__KERNEL_RCSID(0, "$NetBSD: route6.c,v 1.23 2008/04/15 03:57:04 thorpej Exp $");
35
36#include <sys/param.h>
37#include <sys/mbuf.h>
38#include <sys/socket.h>
39#include <sys/systm.h>
40#include <sys/queue.h>
41
42#include <net/if.h>
43
44#include <netinet/in.h>
45#include <netinet6/in6_var.h>
46#include <netinet/ip6.h>
47#include <netinet6/ip6_var.h>
48#include <netinet6/ip6_private.h>
49#include <netinet6/scope6_var.h>
50
51#include <netinet/icmp6.h>
52
53#if 0
54static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *, struct ip6_rthdr0 *);
55#endif
56
57int
58route6_input(struct mbuf **mp, int *offp, int proto)
59{
60 struct ip6_hdr *ip6;
61 struct mbuf *m = *mp;
62 struct ip6_rthdr *rh;
63 int off = *offp, rhlen;
64
65 ip6 = mtod(m, struct ip6_hdr *);
66 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh));
67 if (rh == NULL) {
68 IP6_STATINC(IP6_STAT_TOOSHORT);
69 return IPPROTO_DONE;
70 }
71
72 switch (rh->ip6r_type) {
73#if 0
74 /*
75 * See http://www.secdev.org/conf/IPv6_RH_security-csw07.pdf
76 * for why IPV6_RTHDR_TYPE_0 is banned here.
77 *
78 * We return ICMPv6 parameter problem so that innocent people
79 * (not an attacker) would notice about the use of IPV6_RTHDR_TYPE_0.
80 * Since there's no amplification, and ICMPv6 error will be rate-
81 * controlled, it shouldn't cause any problem.
82 * If you are concerned about this, you may want to use the following
83 * code fragment:
84 *
85 * case IPV6_RTHDR_TYPE_0:
86 * m_freem(m);
87 * return (IPPROTO_DONE);
88 */
89 case IPV6_RTHDR_TYPE_0:
90 rhlen = (rh->ip6r_len + 1) << 3;
91 /*
92 * note on option length:
93 * maximum rhlen: 2048
94 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048
95 * so, here we are assuming that m_pulldown can handle
96 * rhlen == 2048 case. this may not be a good thing to
97 * assume - we may want to avoid pulling it up altogether.
98 */
99 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
100 if (rh == NULL) {
101 IP6_STATINC(IP6_STAT_TOOSHORT);
102 return IPPROTO_DONE;
103 }
104 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
105 return (IPPROTO_DONE);
106 break;
107#endif
108 default:
109 /* unknown routing type */
110 if (rh->ip6r_segleft == 0) {
111 rhlen = (rh->ip6r_len + 1) << 3;
112 break; /* Final dst. Just ignore the header. */
113 }
114 IP6_STATINC(IP6_STAT_BADOPTIONS);
115 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
116 (char *)&rh->ip6r_type - (char *)ip6);
117 return (IPPROTO_DONE);
118 }
119
120 *offp += rhlen;
121 return (rh->ip6r_nxt);
122}
123
124#if 0
125/*
126 * Type0 routing header processing
127 *
128 * RFC2292 backward compatibility warning: no support for strict/loose bitmap,
129 * as it was dropped between RFC1883 and RFC2460.
130 */
131static int
132ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6,
133 struct ip6_rthdr0 *rh0)
134{
135 int addrs, index;
136 struct in6_addr *nextaddr, tmpaddr;
137 const struct ip6aux *ip6a;
138
139 if (rh0->ip6r0_segleft == 0)
140 return (0);
141
142 if (rh0->ip6r0_len % 2
143#ifdef COMPAT_RFC1883
144 || rh0->ip6r0_len > 46
145#endif
146 ) {
147 /*
148 * Type 0 routing header can't contain more than 23 addresses.
149 * RFC 2462: this limitation was removed since strict/loose
150 * bitmap field was deleted.
151 */
152 IP6_STATINC(IP6_STAT_BADOPTIONS);
153 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
154 (char *)&rh0->ip6r0_len - (char *)ip6);
155 return (-1);
156 }
157
158 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
159 IP6_STATINC(IP6_STAT_BADOPTIONS);
160 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
161 (char *)&rh0->ip6r0_segleft - (char *)ip6);
162 return (-1);
163 }
164
165 index = addrs - rh0->ip6r0_segleft;
166 rh0->ip6r0_segleft--;
167 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index;
168
169 /*
170 * reject invalid addresses. be proactive about malicious use of
171 * IPv4 mapped/compat address.
172 * XXX need more checks?
173 */
174 if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
175 IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
176 IN6_IS_ADDR_V4MAPPED(nextaddr) ||
177 IN6_IS_ADDR_V4COMPAT(nextaddr)) {
178 p6stat[IP6_STAT_BADOPTIONS]++;
179 goto bad;
180 }
181 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
182 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
183 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
184 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
185 IP6_STATINC(IP6_STAT_BADOPTIONS);
186 goto bad;
187 }
188
189 /*
190 * Determine the scope zone of the next hop, based on the interface
191 * of the current hop. [RFC4007, Section 9]
192 * Then disambiguate the scope zone for the next hop (if necessary).
193 */
194 if ((ip6a = ip6_getdstifaddr(m)) == NULL)
195 goto bad;
196 if (in6_setzoneid(nextaddr, ip6a->ip6a_scope_id) != 0) {
197 IP6_STATINC(IP6_STAT_BADSCOPE);
198 goto bad;
199 }
200
201 /*
202 * Swap the IPv6 destination address and nextaddr. Forward the packet.
203 */
204 tmpaddr = *nextaddr;
205 *nextaddr = ip6->ip6_dst;
206 in6_clearscope(nextaddr); /* XXX */
207 ip6->ip6_dst = tmpaddr;
208
209#ifdef COMPAT_RFC1883
210 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
211 ip6_forward(m, IPV6_SRCRT_NEIGHBOR);
212 else
213 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR);
214#else
215 ip6_forward(m, 1);
216#endif
217
218 return (-1); /* m would be freed in ip6_forward() */
219
220 bad:
221 m_freem(m);
222 return (-1);
223}
224#endif
225