summaryrefslogtreecommitdiffstats
path: root/usr.sbin/rtsold/rtsol.c
blob: dd9f4a1c8bddb08bcf11d36270e462734eaf41a4 (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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
/*	$KAME: rtsol.c,v 1.27 2003/10/05 00:09:36 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.
 *
 * $FreeBSD$
 */

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/time.h>
#include <sys/queue.h>
#include <sys/wait.h>
#include <sys/stat.h>

#include <net/if.h>
#include <net/route.h>
#include <net/if_dl.h>

#include <netinet/in.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>

#include <arpa/inet.h>

#include <time.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <err.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <syslog.h>
#include "rtsold.h"

#define ALLROUTER "ff02::2"

static struct msghdr rcvmhdr;
static struct msghdr sndmhdr;
static struct iovec rcviov[2];
static struct iovec sndiov[2];
static struct sockaddr_in6 from;
static int rcvcmsglen;

int rssock;

static struct sockaddr_in6 sin6_allrouters =
{sizeof(sin6_allrouters), AF_INET6};

static void call_script __P((char *, char *));
static int safefile __P((const char *));

int
sockopen(void)
{
	static u_char *rcvcmsgbuf = NULL, *sndcmsgbuf = NULL;
	int sndcmsglen, on;
	static u_char answer[1500];
	struct icmp6_filter filt;

	sndcmsglen = rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
	    CMSG_SPACE(sizeof(int));
	if (rcvcmsgbuf == NULL && (rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) {
		warnmsg(LOG_ERR, __func__,
		    "malloc for receive msghdr failed");
		return(-1);
	}
	if (sndcmsgbuf == NULL && (sndcmsgbuf = malloc(sndcmsglen)) == NULL) {
		warnmsg(LOG_ERR, __func__,
		    "malloc for send msghdr failed");
		return(-1);
	}
	memset(&sin6_allrouters, 0, sizeof(struct sockaddr_in6));
	sin6_allrouters.sin6_family = AF_INET6;
	sin6_allrouters.sin6_len = sizeof(sin6_allrouters);
	if (inet_pton(AF_INET6, ALLROUTER,
	    &sin6_allrouters.sin6_addr.s6_addr) != 1) {
		warnmsg(LOG_ERR, __func__, "inet_pton failed for %s",
		    ALLROUTER);
		return(-1);
	}

	if ((rssock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
		warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
		return(-1);
	}

	/* specify to tell receiving interface */
	on = 1;
#ifdef IPV6_RECVPKTINFO
	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
	    sizeof(on)) < 0) {
		warnmsg(LOG_ERR, __func__, "IPV6_RECVPKTINFO: %s",
		    strerror(errno));
		exit(1);
	}
#else  /* old adv. API */
	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
	    sizeof(on)) < 0) {
		warnmsg(LOG_ERR, __func__, "IPV6_PKTINFO: %s",
		    strerror(errno));
		exit(1);
	}
#endif

	on = 1;
	/* specify to tell value of hoplimit field of received IP6 hdr */
#ifdef IPV6_RECVHOPLIMIT
	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
	    sizeof(on)) < 0) {
		warnmsg(LOG_ERR, __func__, "IPV6_RECVHOPLIMIT: %s",
		    strerror(errno));
		exit(1);
	}
#else  /* old adv. API */
	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
	    sizeof(on)) < 0) {
		warnmsg(LOG_ERR, __func__, "IPV6_HOPLIMIT: %s",
		    strerror(errno));
		exit(1);
	}
#endif

	/* specfiy to accept only router advertisements on the socket */
	ICMP6_FILTER_SETBLOCKALL(&filt);
	ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
	if (setsockopt(rssock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
	    sizeof(filt)) == -1) {
		warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s",
		    strerror(errno));
		return(-1);
	}

	/* initialize msghdr for receiving packets */
	rcviov[0].iov_base = (caddr_t)answer;
	rcviov[0].iov_len = sizeof(answer);
	rcvmhdr.msg_name = (caddr_t)&from;
	rcvmhdr.msg_iov = rcviov;
	rcvmhdr.msg_iovlen = 1;
	rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;

	/* 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 = sndcmsglen;

	return(rssock);
}

void
sendpacket(struct ifinfo *ifinfo)
{
	struct in6_pktinfo *pi;
	struct cmsghdr *cm;
	int hoplimit = 255;
	int i;
	struct sockaddr_in6 dst;

	dst = sin6_allrouters;
	dst.sin6_scope_id = ifinfo->linkid;

	sndmhdr.msg_name = (caddr_t)&dst;
	sndmhdr.msg_iov[0].iov_base = (caddr_t)ifinfo->rs_data;
	sndmhdr.msg_iov[0].iov_len = ifinfo->rs_datalen;

	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 = ifinfo->sdl->sdl_index;

	/* specify the hop limit of the packet */
	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, __func__,
	    "send RS on %s, whose state is %d",
	    ifinfo->ifname, ifinfo->state);
	i = sendmsg(rssock, &sndmhdr, 0);
	if (i < 0 || i != ifinfo->rs_datalen) {
		/*
		 * ENETDOWN is not so serious, especially when using several
		 * network cards on a mobile node. We ignore it.
		 */
		if (errno != ENETDOWN || dflag > 0)
			warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
			    ifinfo->ifname, strerror(errno));
	}

	/* update counter */
	ifinfo->probes++;
}

void
rtsol_input(int s)
{
	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
	int ifindex = 0, i, *hlimp = NULL;
	struct in6_pktinfo *pi = NULL;
	struct ifinfo *ifi = NULL;
	struct icmp6_hdr *icp;
	struct nd_router_advert *nd_ra;
	struct cmsghdr *cm;

	/* get message.  namelen and controllen must always be initialized. */
	rcvmhdr.msg_namelen = sizeof(from);
	rcvmhdr.msg_controllen = rcvcmsglen;
	if ((i = recvmsg(s, &rcvmhdr, 0)) < 0) {
		warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno));
		return;
	}

	/* extract optional information via Advanced API */
	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr); cm;
	    cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
		if (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));
			ifindex = pi->ipi6_ifindex;
		}
		if (cm->cmsg_level == IPPROTO_IPV6 &&
		    cm->cmsg_type == IPV6_HOPLIMIT &&
		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
			hlimp = (int *)CMSG_DATA(cm);
	}

	if (ifindex == 0) {
		warnmsg(LOG_ERR, __func__,
		    "failed to get receiving interface");
		return;
	}
	if (hlimp == NULL) {
		warnmsg(LOG_ERR, __func__,
		    "failed to get receiving hop limit");
		return;
	}

	if (i < sizeof(struct nd_router_advert)) {
		warnmsg(LOG_INFO, __func__,
		    "packet size(%d) is too short", i);
		return;
	}

	icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;

	if (icp->icmp6_type != ND_ROUTER_ADVERT) {
		/*
		 * this should not happen because we configured a filter
		 * that only passes RAs on the receiving socket.
		 */
		warnmsg(LOG_ERR, __func__,
		    "invalid icmp type(%d) from %s on %s", icp->icmp6_type,
		    inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
		    INET6_ADDRSTRLEN),
		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
		return;
	}

	if (icp->icmp6_code != 0) {
		warnmsg(LOG_INFO, __func__,
		    "invalid icmp code(%d) from %s on %s", icp->icmp6_code,
		    inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
		    INET6_ADDRSTRLEN),
		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
		return;
	}

	if (*hlimp != 255) {
		warnmsg(LOG_INFO, __func__,
		    "invalid RA with hop limit(%d) from %s on %s",
		    *hlimp,
		    inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
		    INET6_ADDRSTRLEN),
		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
		return;
	}

	if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) {
		warnmsg(LOG_INFO, __func__,
		    "invalid RA with non link-local source from %s on %s",
		    inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
		    INET6_ADDRSTRLEN),
		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
		return;
	}

	/* xxx: more validation? */

	if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) {
		warnmsg(LOG_INFO, __func__,
		    "received RA from %s on an unexpected IF(%s)",
		    inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
		    INET6_ADDRSTRLEN),
		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
		return;
	}

	warnmsg(LOG_DEBUG, __func__,
	    "received RA from %s on %s, state is %d",
	    inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, INET6_ADDRSTRLEN),
	    ifi->ifname, ifi->state);

	nd_ra = (struct nd_router_advert *)icp;

	/*
	 * Process the "O bit."
	 * If the value of OtherConfigFlag changes from FALSE to TRUE, the
	 * host should invoke the stateful autoconfiguration protocol,
	 * requesting information.
	 * [RFC 2462 Section 5.5.3]
	 */
	if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) &&
	    !ifi->otherconfig) {
		warnmsg(LOG_DEBUG, __func__,
		    "OtherConfigFlag on %s is turned on", ifi->ifname);
		ifi->otherconfig = 1;
		call_script(otherconf_script, ifi->ifname);
	}

	ifi->racnt++;

	switch (ifi->state) {
	case IFS_IDLE:		/* should be ignored */
	case IFS_DELAY:		/* right? */
		break;
	case IFS_PROBE:
		ifi->state = IFS_IDLE;
		ifi->probes = 0;
		rtsol_timer_update(ifi);
		break;
	}
}

static void
call_script(char *scriptpath, char *ifname)
{
	pid_t pid, wpid;

	if (scriptpath == NULL)
		return;

	/* launch the script */
	pid = fork();
	if (pid < 0) {
		warnmsg(LOG_ERR, __func__,
		    "failed to fork: %s", strerror(errno));
		return;
	} else if (pid) {
		int wstatus;

		do {
			wpid = wait(&wstatus);
		} while (wpid != pid && wpid > 0);

		if (wpid < 0)
			warnmsg(LOG_ERR, __func__,
			    "wait: %s", strerror(errno));
		else {
			warnmsg(LOG_DEBUG, __func__,
			    "script \"%s\" terminated", scriptpath);
		}
	} else {
		char *argv[3];
		int fd;

		argv[0] = scriptpath;
		argv[1] = ifname;
		argv[2] = NULL;

		if (safefile(scriptpath)) {
			warnmsg(LOG_ERR, __func__,
			    "script \"%s\" cannot be executed safely",
			    scriptpath);
			exit(1);
		}

		if ((fd = open("/dev/null", O_RDWR)) != -1) {
			dup2(fd, STDIN_FILENO);
			dup2(fd, STDOUT_FILENO);
			dup2(fd, STDERR_FILENO);
			if (fd > STDERR_FILENO)
				close(fd);
		}

		execv(scriptpath, argv);

		warnmsg(LOG_ERR, __func__, "child: exec failed: %s",
		    strerror(errno));
		exit(0);
	}

	return;
}

static int
safefile(const char *path)
{
	struct stat s;
	uid_t myuid;

	/* no setuid */
	if (getuid() != geteuid()) {
		warnmsg(LOG_NOTICE, __func__,
		    "setuid'ed execution not allowed\n");
		return (-1);
	}

	if (lstat(path, &s) != 0) {
		warnmsg(LOG_NOTICE, __func__, "lstat failed: %s",
		    strerror(errno));
		return (-1);
	}

	/* the file must be owned by the running uid */
	myuid = getuid();
	if (s.st_uid != myuid) {
		warnmsg(LOG_NOTICE, __func__,
		    "%s has invalid owner uid\n", path);
		return (-1);
	}

	switch (s.st_mode & S_IFMT) {
	case S_IFREG:
		break;
	default:
		warnmsg(LOG_NOTICE, __func__,
		    "%s is an invalid file type 0x%o\n",
		    path, (s.st_mode & S_IFMT));
		return (-1);
	}

	return (0);
}
OpenPOWER on IntegriCloud