FreeBSD/Linux Kernel Cross Reference
sys/netinet6/route6.c
1 /* $FreeBSD: releng/6.2/sys/netinet6/route6.c 169063 2007-04-26 23:42:23Z cperciva $ */
2 /* $KAME: route6.c,v 1.24 2001/03/14 03:07:05 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 "opt_inet.h"
34 #include "opt_inet6.h"
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/scope6_var.h>
49
50 #include <netinet/icmp6.h>
51
52 extern int ip6_rthdr0_allowed;
53
54 static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *,
55 struct ip6_rthdr0 *));
56
57 int
58 route6_input(mp, offp, proto)
59 struct mbuf **mp;
60 int *offp, proto; /* proto is unused */
61 {
62 struct ip6_hdr *ip6;
63 struct mbuf *m = *mp;
64 struct ip6_rthdr *rh;
65 int off = *offp, rhlen;
66 struct ip6aux *ip6a;
67
68 ip6a = ip6_findaux(m);
69 if (ip6a) {
70 /* XXX reject home-address option before rthdr */
71 if (ip6a->ip6a_flags & IP6A_SWAP) {
72 ip6stat.ip6s_badoptions++;
73 m_freem(m);
74 return IPPROTO_DONE;
75 }
76 }
77
78 #ifndef PULLDOWN_TEST
79 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE);
80 ip6 = mtod(m, struct ip6_hdr *);
81 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off);
82 #else
83 ip6 = mtod(m, struct ip6_hdr *);
84 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh));
85 if (rh == NULL) {
86 ip6stat.ip6s_tooshort++;
87 return IPPROTO_DONE;
88 }
89 #endif
90
91 switch (rh->ip6r_type) {
92 case IPV6_RTHDR_TYPE_0:
93 if (!ip6_rthdr0_allowed)
94 return (IPPROTO_DONE);
95 rhlen = (rh->ip6r_len + 1) << 3;
96 #ifndef PULLDOWN_TEST
97 /*
98 * note on option length:
99 * due to IP6_EXTHDR_CHECK assumption, we cannot handle
100 * very big routing header (max rhlen == 2048).
101 */
102 IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE);
103 #else
104 /*
105 * note on option length:
106 * maximum rhlen: 2048
107 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048
108 * so, here we are assuming that m_pulldown can handle
109 * rhlen == 2048 case. this may not be a good thing to
110 * assume - we may want to avoid pulling it up altogether.
111 */
112 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
113 if (rh == NULL) {
114 ip6stat.ip6s_tooshort++;
115 return IPPROTO_DONE;
116 }
117 #endif
118 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
119 return (IPPROTO_DONE);
120 break;
121 default:
122 /* unknown routing type */
123 if (rh->ip6r_segleft == 0) {
124 rhlen = (rh->ip6r_len + 1) << 3;
125 break; /* Final dst. Just ignore the header. */
126 }
127 ip6stat.ip6s_badoptions++;
128 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
129 (caddr_t)&rh->ip6r_type - (caddr_t)ip6);
130 return (IPPROTO_DONE);
131 }
132
133 *offp += rhlen;
134 return (rh->ip6r_nxt);
135 }
136
137 /*
138 * Type0 routing header processing
139 *
140 * RFC2292 backward compatibility warning: no support for strict/loose bitmap,
141 * as it was dropped between RFC1883 and RFC2460.
142 */
143 static int
144 ip6_rthdr0(m, ip6, rh0)
145 struct mbuf *m;
146 struct ip6_hdr *ip6;
147 struct ip6_rthdr0 *rh0;
148 {
149 int addrs, index;
150 struct in6_addr *nextaddr, tmpaddr;
151 struct in6_ifaddr *ifa;
152
153 if (rh0->ip6r0_segleft == 0)
154 return (0);
155
156 if (rh0->ip6r0_len % 2
157 #ifdef COMPAT_RFC1883
158 || rh0->ip6r0_len > 46
159 #endif
160 ) {
161 /*
162 * Type 0 routing header can't contain more than 23 addresses.
163 * RFC 2462: this limitation was removed since strict/loose
164 * bitmap field was deleted.
165 */
166 ip6stat.ip6s_badoptions++;
167 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
168 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6);
169 return (-1);
170 }
171
172 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
173 ip6stat.ip6s_badoptions++;
174 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
175 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6);
176 return (-1);
177 }
178
179 index = addrs - rh0->ip6r0_segleft;
180 rh0->ip6r0_segleft--;
181 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index;
182
183 /*
184 * reject invalid addresses. be proactive about malicious use of
185 * IPv4 mapped/compat address.
186 * XXX need more checks?
187 */
188 if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
189 IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
190 IN6_IS_ADDR_V4MAPPED(nextaddr) ||
191 IN6_IS_ADDR_V4COMPAT(nextaddr)) {
192 ip6stat.ip6s_badoptions++;
193 m_freem(m);
194 return (-1);
195 }
196 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
197 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
198 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
199 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
200 ip6stat.ip6s_badoptions++;
201 m_freem(m);
202 return (-1);
203 }
204
205 /*
206 * Determine the scope zone of the next hop, based on the interface
207 * of the current hop. [RFC4007, Section 9]
208 * Then disambiguate the scope zone for the next hop (if necessary).
209 */
210 if ((ifa = ip6_getdstifaddr(m)) == NULL)
211 goto bad;
212 if (in6_setscope(nextaddr, ifa->ia_ifp, NULL) != 0) {
213 ip6stat.ip6s_badscope++;
214 goto bad;
215 }
216
217 /*
218 * Swap the IPv6 destination address and nextaddr. Forward the packet.
219 */
220 tmpaddr = *nextaddr;
221 *nextaddr = ip6->ip6_dst;
222 in6_clearscope(nextaddr); /* XXX */
223 ip6->ip6_dst = tmpaddr;
224
225 #ifdef COMPAT_RFC1883
226 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
227 ip6_forward(m, IPV6_SRCRT_NEIGHBOR);
228 else
229 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR);
230 #else
231 ip6_forward(m, 1);
232 #endif
233
234 return (-1); /* m would be freed in ip6_forward() */
235
236 bad:
237 m_freem(m);
238 return (-1);
239 }
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