FreeBSD/Linux Kernel Cross Reference
sys/netinet6/route6.c
1 /* $NetBSD: route6.c,v 1.16.2.1 2007/04/28 18:30:13 bouyer 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 1.16.2.1 2007/04/28 18:30:13 bouyer 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/scope6_var.h>
49
50 #include <netinet/icmp6.h>
51
52 int ip6_rht0 = -1; /* disabled by default */
53
54 static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *, struct ip6_rthdr0 *);
55
56 int
57 route6_input(struct mbuf **mp, int *offp, int proto)
58 {
59 struct ip6_hdr *ip6;
60 struct mbuf *m = *mp;
61 struct ip6_rthdr *rh;
62 int off = *offp, rhlen;
63
64 ip6 = mtod(m, struct ip6_hdr *);
65 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh));
66 if (rh == NULL) {
67 ip6stat.ip6s_tooshort++;
68 return IPPROTO_DONE;
69 }
70
71 switch (rh->ip6r_type) {
72 case IPV6_RTHDR_TYPE_0:
73 if ((ip6_forwarding && ip6_rht0 == 0) || ip6_rht0 > 0) {
74 rhlen = (rh->ip6r_len + 1) << 3;
75 /*
76 * note on option length:
77 * maximum rhlen: 2048
78 * max mbuf m_pulldown can handle: MCLBYTES == usually
79 * 2048 so, here we are assuming that m_pulldown can
80 * handle hlen == 2048 case. This may not be a good
81 * thing to assume - we may want to avoid pulling it
82 * up altogether.
83 */
84 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
85 if (rh == NULL) {
86 ip6stat.ip6s_tooshort++;
87 return IPPROTO_DONE;
88 }
89 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
90 return IPPROTO_DONE;
91 break;
92 }
93 /*FALLTHROUGH*/
94 default:
95 /* unknown routing type */
96 if (rh->ip6r_segleft == 0) {
97 rhlen = (rh->ip6r_len + 1) << 3;
98 break; /* Final dst. Just ignore the header. */
99 }
100 ip6stat.ip6s_badoptions++;
101 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
102 (caddr_t)&rh->ip6r_type - (caddr_t)ip6);
103 return (IPPROTO_DONE);
104 }
105
106 *offp += rhlen;
107 return (rh->ip6r_nxt);
108 }
109
110 /*
111 * Type0 routing header processing
112 *
113 * RFC2292 backward compatibility warning: no support for strict/loose bitmap,
114 * as it was dropped between RFC1883 and RFC2460.
115 */
116 static int
117 ip6_rthdr0(m, ip6, rh0)
118 struct mbuf *m;
119 struct ip6_hdr *ip6;
120 struct ip6_rthdr0 *rh0;
121 {
122 int addrs, index;
123 struct in6_addr *nextaddr, tmpaddr;
124 struct in6_ifaddr *ifa;
125
126 if (rh0->ip6r0_segleft == 0)
127 return (0);
128
129 if (rh0->ip6r0_len % 2
130 #ifdef COMPAT_RFC1883
131 || rh0->ip6r0_len > 46
132 #endif
133 ) {
134 /*
135 * Type 0 routing header can't contain more than 23 addresses.
136 * RFC 2462: this limitation was removed since strict/loose
137 * bitmap field was deleted.
138 */
139 ip6stat.ip6s_badoptions++;
140 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
141 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6);
142 return (-1);
143 }
144
145 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
146 ip6stat.ip6s_badoptions++;
147 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
148 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6);
149 return (-1);
150 }
151
152 index = addrs - rh0->ip6r0_segleft;
153 rh0->ip6r0_segleft--;
154 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index;
155
156 /*
157 * reject invalid addresses. be proactive about malicious use of
158 * IPv4 mapped/compat address.
159 * XXX need more checks?
160 */
161 if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
162 IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
163 IN6_IS_ADDR_V4MAPPED(nextaddr) ||
164 IN6_IS_ADDR_V4COMPAT(nextaddr)) {
165 ip6stat.ip6s_badoptions++;
166 goto bad;
167 }
168 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
169 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
170 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
171 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
172 ip6stat.ip6s_badoptions++;
173 goto bad;
174 }
175
176 /*
177 * Determine the scope zone of the next hop, based on the interface
178 * of the current hop. [RFC4007, Section 9]
179 * Then disambiguate the scope zone for the next hop (if necessary).
180 */
181 if ((ifa = ip6_getdstifaddr(m)) == NULL)
182 goto bad;
183 if (in6_setscope(nextaddr, ifa->ia_ifp, NULL) != 0) {
184 ip6stat.ip6s_badscope++;
185 goto bad;
186 }
187
188 /*
189 * Swap the IPv6 destination address and nextaddr. Forward the packet.
190 */
191 tmpaddr = *nextaddr;
192 *nextaddr = ip6->ip6_dst;
193 in6_clearscope(nextaddr); /* XXX */
194 ip6->ip6_dst = tmpaddr;
195
196 #ifdef COMPAT_RFC1883
197 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
198 ip6_forward(m, IPV6_SRCRT_NEIGHBOR);
199 else
200 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR);
201 #else
202 ip6_forward(m, 1);
203 #endif
204
205 return (-1); /* m would be freed in ip6_forward() */
206
207 bad:
208 m_freem(m);
209 return (-1);
210 }
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