summaryrefslogtreecommitdiffstats
path: root/usr.sbin/rtsold/probe.c
blob: 34bb66e4ae6885e5fe805fc438701d3025f00cae (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
/*	$KAME: probe.c,v 1.10 2000/08/13 06:14:59 itojun Exp $	*/

/*
 * Copyright (C) 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.
 *
 * $FreeBSD$
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/queue.h>

#include <net/if.h>
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
#include <net/if_var.h>
#endif /* __FreeBSD__ >= 3 */

#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/nd6.h>

#include <arpa/inet.h>

#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <syslog.h>
#include <stdlib.h>

#include "rtsold.h"

static struct msghdr sndmhdr;
static struct iovec sndiov[2];
static int probesock;
static void sendprobe __P((struct in6_addr *addr, int ifindex));


int
probe_init()
{
	int scmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
		CMSG_SPACE(sizeof(int));
	static u_char *sndcmsgbuf = NULL;
	
	if (sndcmsgbuf == NULL &&
	    (sndcmsgbuf = (u_char *)malloc(scmsglen)) == NULL) {
		warnmsg(LOG_ERR, __FUNCTION__, "malloc failed");
		return(-1);
	}

	if ((probesock = socket(AF_INET6, SOCK_RAW, IPPROTO_NONE)) < 0) {
		warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno));
		return(-1);
	}

	/* make the socket send-only */
	if (shutdown(probesock, 0)) {
		warnmsg(LOG_ERR, __FUNCTION__, "shutdown: %s", strerror(errno));
		return(-1);
	}

	/* initialize msghdr for sending packets */
	sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
	sndmhdr.msg_iov = sndiov;
	sndmhdr.msg_iovlen = 1;
	sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
	sndmhdr.msg_controllen = scmsglen;

	return(0);
}

/*
 * Probe if each router in the default router list is still alive. 
 */
void
defrouter_probe(int ifindex)
{
	struct in6_drlist dr;
	int s, i;
	u_char ntopbuf[INET6_ADDRSTRLEN];

	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
		warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno));
		return;
	}
	bzero(&dr, sizeof(dr));
	strcpy(dr.ifname, "lo0"); /* dummy interface */
	if (ioctl(s, SIOCGDRLST_IN6, (caddr_t)&dr) < 0) {
		warnmsg(LOG_ERR, __FUNCTION__, "ioctl(SIOCGDRLST_IN6): %s",
		       strerror(errno));
		goto closeandend;
	}

	for(i = 0; dr.defrouter[i].if_index && i < PRLSTSIZ; i++) {
		if (ifindex && dr.defrouter[i].if_index == ifindex) {
			/* sanity check */
			if (!IN6_IS_ADDR_LINKLOCAL(&dr.defrouter[i].rtaddr)) {
				warnmsg(LOG_ERR, __FUNCTION__,
					"default router list contains a "
					"non-linklocal address(%s)",
				       inet_ntop(AF_INET6,
						 &dr.defrouter[i].rtaddr,
						 ntopbuf, INET6_ADDRSTRLEN));
				continue; /* ignore the address */
			}
			sendprobe(&dr.defrouter[i].rtaddr,
				  dr.defrouter[i].if_index);
		}
	}

  closeandend:
	close(s);
	return;
}

static void
sendprobe(struct in6_addr *addr, int ifindex)
{
	struct sockaddr_in6 sa6_probe;
	struct in6_pktinfo *pi;
	struct cmsghdr *cm;
	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];;

	bzero(&sa6_probe, sizeof(sa6_probe));
	sa6_probe.sin6_family = AF_INET6;
	sa6_probe.sin6_len = sizeof(sa6_probe);
	sa6_probe.sin6_addr = *addr;

	sndmhdr.msg_name = (caddr_t)&sa6_probe;
	sndmhdr.msg_iov[0].iov_base = NULL;
	sndmhdr.msg_iov[0].iov_len = 0;

	cm = CMSG_FIRSTHDR(&sndmhdr);
	/* specify the outgoing interface */
	cm->cmsg_level = IPPROTO_IPV6;
	cm->cmsg_type = IPV6_PKTINFO;
	cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
	pi = (struct in6_pktinfo *)CMSG_DATA(cm);
	memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));	/*XXX*/
	pi->ipi6_ifindex = ifindex;

	/* specify the hop limit of the packet for safety */
	{
		int hoplimit = 1;

		cm = CMSG_NXTHDR(&sndmhdr, cm);
		cm->cmsg_level = IPPROTO_IPV6;
		cm->cmsg_type = IPV6_HOPLIMIT;
		cm->cmsg_len = CMSG_LEN(sizeof(int));
		memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
	}

	warnmsg(LOG_DEBUG, __FUNCTION__, "probe a router %s on %s",
	       inet_ntop(AF_INET6, addr, ntopbuf, INET6_ADDRSTRLEN),
	       if_indextoname(ifindex, ifnamebuf));

	if (sendmsg(probesock, &sndmhdr, 0))
		warnmsg(LOG_ERR, __FUNCTION__, "sendmsg on %s: %s",
			if_indextoname(ifindex, ifnamebuf), strerror(errno));

	return;
}
OpenPOWER on IntegriCloud