summaryrefslogtreecommitdiff
path: root/sys/netinet6/route6.c
blob: 951c692344dfd07d685af7d55607be75254bca29 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
/*	$OpenBSD: route6.c,v 1.7 2002/06/08 00:08:40 itojun Exp $	*/
/*	$KAME: route6.c,v 1.22 2000/12/03 00:54:00 itojun Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/systm.h>

#include <net/if.h>

#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>

#include <netinet/icmp6.h>

static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *,
    struct ip6_rthdr0 *);

int
route6_input(mp, offp, proto)
	struct mbuf **mp;
	int *offp, proto;	/* proto is unused */
{
	struct ip6_hdr *ip6;
	struct mbuf *m = *mp;
	struct ip6_rthdr *rh;
	int off = *offp, rhlen;

#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE);
	ip6 = mtod(m, struct ip6_hdr *);
	rh = (struct ip6_rthdr *)((caddr_t)ip6 + off);
#else
	ip6 = mtod(m, struct ip6_hdr *);
	IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh));
	if (rh == NULL) {
		ip6stat.ip6s_tooshort++;
		return IPPROTO_DONE;
	}
#endif

	switch (rh->ip6r_type) {
	case IPV6_RTHDR_TYPE_0:
		rhlen = (rh->ip6r_len + 1) << 3;
#ifndef PULLDOWN_TEST
		/*
		 * note on option length:
		 * due to IP6_EXTHDR_CHECK assumption, we cannot handle
		 * very big routing header (max rhlen == 2048).
		 */
		IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE);
#else
		/*
		 * note on option length:
		 * maximum rhlen: 2048
		 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048
		 * so, here we are assuming that m_pulldown can handle
		 * rhlen == 2048 case.  this may not be a good thing to
		 * assume - we may want to avoid pulling it up altogether.
		 */
		IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
		if (rh == NULL) {
			ip6stat.ip6s_tooshort++;
			return IPPROTO_DONE;
		}
#endif
		if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
			return(IPPROTO_DONE);
		break;
	default:
		/* unknown routing type */
		if (rh->ip6r_segleft == 0) {
			rhlen = (rh->ip6r_len + 1) << 3;
			break;	/* Final dst. Just ignore the header. */
		}
		ip6stat.ip6s_badoptions++;
		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
			    (caddr_t)&rh->ip6r_type - (caddr_t)ip6);
		return(IPPROTO_DONE);
	}

	*offp += rhlen;
	return(rh->ip6r_nxt);
}

/*
 * Type0 routing header processing
 */
static int
ip6_rthdr0(m, ip6, rh0)
	struct mbuf *m;
	struct ip6_hdr *ip6;
	struct ip6_rthdr0 *rh0;
{
	int addrs, index;
	struct in6_addr *nextaddr, tmpaddr;

	if (rh0->ip6r0_segleft == 0)
		return(0);

	if (rh0->ip6r0_len % 2
#ifdef COMPAT_RFC1883
	    || rh0->ip6r0_len > 46
#endif
		) {
		/*
		 * Type 0 routing header can't contain more than 23 addresses.
		 * RFC 2462: this limitation was removed since strict/loose
		 * bitmap field was deleted.
		 */
		ip6stat.ip6s_badoptions++;
		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
			    (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6);
		return(-1);
	}

	if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
		ip6stat.ip6s_badoptions++;
		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
			    (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6);
		return(-1);
	}

	index = addrs - rh0->ip6r0_segleft;
	rh0->ip6r0_segleft--;
	nextaddr = rh0->ip6r0_addr + index;

	/*
	 * reject invalid addresses.  be proactive about malicious use of
	 * IPv4 mapped/compat address.
	 * XXX need more checks?
	 */
	if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
	    IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
	    IN6_IS_ADDR_V4MAPPED(nextaddr) ||
	    IN6_IS_ADDR_V4COMPAT(nextaddr)) {
		ip6stat.ip6s_badoptions++;
		m_freem(m);
		return(-1);
	}
	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
		ip6stat.ip6s_badoptions++;
		m_freem(m);
		return(-1);
	}

	/*
	 * Swap the IPv6 destination address and nextaddr. Forward the packet.
	 */
	tmpaddr = *nextaddr;
	*nextaddr = ip6->ip6_dst;
	if (IN6_IS_ADDR_LINKLOCAL(nextaddr))
		nextaddr->s6_addr16[1] = 0;
	ip6->ip6_dst = tmpaddr;
	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
		ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);

#ifdef COMPAT_RFC1883
	if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8))))
		ip6_forward(m, IPV6_SRCRT_NEIGHBOR);
	else
		ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR);
#else
	ip6_forward(m, 1);
#endif

	return(-1);			/* m would be freed in ip6_forward() */
}