1/*
2 * Copyright (c) 2009 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29/*	$KAME: probe.c,v 1.10 2000/08/13 06:14:59 itojun Exp $	*/
30
31/*
32 * Copyright (C) 1998 WIDE Project.
33 * All rights reserved.
34 *
35 * Redistribution and use in source and binary forms, with or without
36 * modification, are permitted provided that the following conditions
37 * are met:
38 * 1. Redistributions of source code must retain the above copyright
39 *    notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 *    notice, this list of conditions and the following disclaimer in the
42 *    documentation and/or other materials provided with the distribution.
43 * 3. Neither the name of the project nor the names of its contributors
44 *    may be used to endorse or promote products derived from this software
45 *    without specific prior written permission.
46 *
47 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
48 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
51 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
52 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
53 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
54 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
55 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
56 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
57 * SUCH DAMAGE.
58 *
59 * $FreeBSD: src/usr.sbin/rtsold/probe.c,v 1.2.2.3 2001/07/03 11:02:16 ume Exp $
60 */
61
62#include <sys/param.h>
63#include <sys/types.h>
64#include <sys/ioctl.h>
65#include <sys/socket.h>
66#include <sys/uio.h>
67#include <sys/queue.h>
68
69#include <net/if.h>
70#if defined(__FreeBSD__) && __FreeBSD__ >= 3
71#include <net/if_var.h>
72#endif /* __FreeBSD__ >= 3 */
73
74#include <netinet/in.h>
75#include <netinet6/in6_var.h>
76#include <netinet/icmp6.h>
77#include <netinet6/nd6.h>
78
79#include <arpa/inet.h>
80
81#include <errno.h>
82#include <unistd.h>
83#include <string.h>
84#include <syslog.h>
85#include <stdlib.h>
86
87#include "rtsold.h"
88
89static struct msghdr sndmhdr;
90static struct iovec sndiov[2];
91static int probesock;
92static void sendprobe __P((struct in6_addr *addr, int ifindex));
93
94
95int
96probe_init()
97{
98	int scmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
99		CMSG_SPACE(sizeof(int));
100	static u_char *sndcmsgbuf = NULL;
101
102	if (sndcmsgbuf == NULL &&
103	    (sndcmsgbuf = (u_char *)malloc(scmsglen)) == NULL) {
104		warnmsg(LOG_ERR, __FUNCTION__, "malloc failed");
105		return(-1);
106	}
107
108	if ((probesock = socket(AF_INET6, SOCK_RAW, IPPROTO_NONE)) < 0) {
109		warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno));
110		return(-1);
111	}
112
113#ifndef __APPLE__
114	/* make the socket send-only */
115	if (shutdown(probesock, 0)) {
116		warnmsg(LOG_ERR, __FUNCTION__, "shutdown: %s", strerror(errno));
117		return(-1);
118	}
119#endif /* __APPLE__ */
120
121	/* initialize msghdr for sending packets */
122	sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
123	sndmhdr.msg_iov = sndiov;
124	sndmhdr.msg_iovlen = 1;
125	sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
126	sndmhdr.msg_controllen = scmsglen;
127
128	return(0);
129}
130
131/*
132 * Probe if each router in the default router list is still alive.
133 */
134void
135defrouter_probe(int ifindex)
136{
137	struct in6_drlist dr;
138	int s, i;
139	u_char ntopbuf[INET6_ADDRSTRLEN];
140
141	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
142		warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno));
143		return;
144	}
145	bzero(&dr, sizeof(dr));
146	strlcpy(dr.ifname, "lo0", sizeof(dr.ifname)); /* dummy interface */
147	if (ioctl(s, SIOCGDRLST_IN6, (caddr_t)&dr) < 0) {
148		warnmsg(LOG_ERR, __FUNCTION__, "ioctl(SIOCGDRLST_IN6): %s",
149		       strerror(errno));
150		goto closeandend;
151	}
152
153	for(i = 0; dr.defrouter[i].if_index && i < PRLSTSIZ; i++) {
154		if (ifindex && dr.defrouter[i].if_index == ifindex) {
155			/* sanity check */
156			if (!IN6_IS_ADDR_LINKLOCAL(&dr.defrouter[i].rtaddr)) {
157				warnmsg(LOG_ERR, __FUNCTION__,
158					"default router list contains a "
159					"non-linklocal address(%s)",
160				       inet_ntop(AF_INET6,
161						 &dr.defrouter[i].rtaddr,
162						 (char *)ntopbuf, INET6_ADDRSTRLEN));
163				continue; /* ignore the address */
164			}
165			sendprobe(&dr.defrouter[i].rtaddr,
166				  dr.defrouter[i].if_index);
167		}
168	}
169
170  closeandend:
171	close(s);
172	return;
173}
174
175static void
176sendprobe(struct in6_addr *addr, int ifindex)
177{
178	struct sockaddr_in6 sa6_probe;
179	struct in6_pktinfo *pi;
180	struct cmsghdr *cm;
181	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];;
182
183	bzero(&sa6_probe, sizeof(sa6_probe));
184	sa6_probe.sin6_family = AF_INET6;
185	sa6_probe.sin6_len = sizeof(sa6_probe);
186	sa6_probe.sin6_addr = *addr;
187
188	sndmhdr.msg_name = (caddr_t)&sa6_probe;
189	sndmhdr.msg_iov[0].iov_base = NULL;
190	sndmhdr.msg_iov[0].iov_len = 0;
191
192	cm = CMSG_FIRSTHDR(&sndmhdr);
193	/* specify the outgoing interface */
194	cm->cmsg_level = IPPROTO_IPV6;
195	cm->cmsg_type = IPV6_PKTINFO;
196	cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
197	pi = (struct in6_pktinfo *)CMSG_DATA(cm);
198	memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));	/*XXX*/
199	pi->ipi6_ifindex = ifindex;
200
201	/* specify the hop limit of the packet for safety */
202	{
203		int hoplimit = 1;
204
205		cm = CMSG_NXTHDR(&sndmhdr, cm);
206		cm->cmsg_level = IPPROTO_IPV6;
207		cm->cmsg_type = IPV6_HOPLIMIT;
208		cm->cmsg_len = CMSG_LEN(sizeof(int));
209		memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
210	}
211
212	warnmsg(LOG_DEBUG, __FUNCTION__, "probe a router %s on %s",
213	       inet_ntop(AF_INET6, addr, (char *)ntopbuf, INET6_ADDRSTRLEN),
214	       if_indextoname(ifindex, (char *)ifnamebuf));
215
216	if (sendmsg(probesock, &sndmhdr, 0))
217		warnmsg(LOG_ERR, __FUNCTION__, "sendmsg on %s: %s",
218			if_indextoname(ifindex, (char *)ifnamebuf), strerror(errno));
219
220	return;
221}
222