1 /**	$MirOS: src/usr.sbin/ifwatchd/ifwatchd.c,v 1.2 2005/03/13 19:17:01 tg Exp $ */
2 /*	$NetBSD: ifwatchd.c,v 1.20 2004/11/25 06:57:38 martin Exp $	*/
3 
4 /*-
5  * Copyright (c) 2002, 2003 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Martin Husemann <martin@NetBSD.org>.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *        This product includes software developed by the NetBSD
22  *        Foundation, Inc. and its contributors.
23  * 4. Neither the name of The NetBSD Foundation nor the names of its
24  *    contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Define this for special treatment of sys/net/if_spppsubr.c based interfaces.
42  */
43 #define SPPP_IF_SUPPORT
44 
45 #include <sys/param.h>
46 #include <sys/ioctl.h>
47 #include <sys/socket.h>
48 #include <sys/queue.h>
49 #include <sys/wait.h>
50 #include <net/if.h>
51 #include <net/if_dl.h>
52 #include <net/if_media.h>
53 #ifdef SPPP_IF_SUPPORT
54 #include <net/if_sppp.h>
55 #endif
56 #include <net/route.h>
57 #include <netinet/in.h>
58 #include <arpa/inet.h>
59 
60 #include <paths.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <unistd.h>
65 #include <netdb.h>
66 #include <err.h>
67 #include <ifaddrs.h>
68 #include <syslog.h>
69 #include <sysexits.h>
70 
71 __RCSID("$MirOS: src/usr.sbin/ifwatchd/ifwatchd.c,v 1.2 2005/03/13 19:17:01 tg Exp $");
72 
73 enum event { ARRIVAL, DEPARTURE, UP, DOWN, CARRIER, NO_CARRIER };
74 
75 /* local functions */
76 static void usage(void);
77 static void dispatch(void*, size_t);
78 static void check_addrs(char *cp, int addrs, enum event ev);
79 static void invoke_script(struct sockaddr *sa, struct sockaddr *dst, enum event ev, int ifindex, const char *ifname_hint);
80 static void list_interfaces(const char *ifnames);
81 static void check_announce(struct if_announcemsghdr *ifan);
82 static void check_carrier(int if_index, int carrier);
83 static void rescan_interfaces(void);
84 static void free_interfaces(void);
85 static int find_interface(int index);
86 static void run_initial_ups(void);
87 
88 #ifdef SPPP_IF_SUPPORT
89 static int check_is_connected(const char * ifname, int def_retvalue);
90 #define if_is_connected(X)	(check_is_connected((X), 1))
91 #define if_is_not_connected(X)	(!check_is_connected((X), 0))
92 #else
93 #define	if_is_connected(X)	1
94 #define	if_is_not_connected(X)	1
95 #endif
96 
97 /* stolen from /sbin/route */
98 #define ROUNDUP(a) \
99 	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
100 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
101 
102 /* global variables */
103 static int verbose = 0, quiet = 0;
104 static int inhibit_initial = 0;
105 static const char *arrival_script = NULL;
106 static const char *departure_script = NULL;
107 static const char *up_script = NULL;
108 static const char *down_script = NULL;
109 static const char *carrier_script = NULL;
110 static const char *no_carrier_script = NULL;
111 static const char DummyTTY[] = _PATH_DEVNULL;
112 static const char DummySpeed[] = "9600";
113 static const char **scripts[] = {
114 	&arrival_script,
115 	&departure_script,
116 	&up_script,
117 	&down_script,
118 	&carrier_script,
119 	&no_carrier_script
120 };
121 
122 struct interface_data {
123 	SLIST_ENTRY(interface_data) next;
124 	int index;
125 	int last_carrier_status;
126 	char * ifname;
127 };
128 SLIST_HEAD(,interface_data) ifs = SLIST_HEAD_INITIALIZER(ifs);
129 
130 int
main(int argc,char ** argv)131 main(int argc, char **argv)
132 {
133 	int c, s, n;
134 	int errs = 0;
135 	char msg[2048], *msgp;
136 
137 	openlog(argv[0], LOG_PID|LOG_CONS, LOG_DAEMON);
138 	while ((c = getopt(argc, argv, "qvhic:n:u:d:A:D:")) != -1)
139 		switch (c) {
140 		case 'h':
141 			usage();
142 			return 0;
143 
144 		case 'i':
145 			inhibit_initial = 1;
146 			break;
147 
148 		case 'v':
149 			verbose++;
150 			break;
151 
152 		case 'q':
153 			quiet = 1;
154 			break;
155 
156 		case 'c':
157 			carrier_script = optarg;
158 			break;
159 
160 		case 'n':
161 			no_carrier_script = optarg;
162 			break;
163 
164 		case 'u':
165 			up_script = optarg;
166 			break;
167 
168 		case 'd':
169 			down_script = optarg;
170 			break;
171 
172 		case 'A':
173 			arrival_script = optarg;
174 			break;
175 
176 		case 'D':
177 			departure_script = optarg;
178 			break;
179 
180 		default:
181 			errs++;
182 			break;
183 		}
184 
185 	if (errs)
186 		usage();
187 
188 	argv += optind;
189 	argc -= optind;
190 
191 	if (argc <= 0)
192 		usage();
193 
194 	if (verbose) {
195 		printf("up_script: %s\ndown_script: %s\n",
196 			up_script, down_script);
197 		printf("arrival_script: %s\ndeparture_script: %s\n",
198 			arrival_script, departure_script);
199 		printf("carrier_script: %s\nno_carrier_script: %s\n",
200 			carrier_script, no_carrier_script);
201 		printf("verbosity = %d\n", verbose);
202 	}
203 
204 	while (argc > 0) {
205 		list_interfaces(argv[0]);
206 		argv++;
207 		argc--;
208 	}
209 
210 	if (!verbose)
211 		daemon(0,0);
212 
213 	s = socket(PF_ROUTE, SOCK_RAW, 0);
214 	if (s < 0) {
215 		syslog(LOG_ERR, "error opening routing socket: %m");
216 		perror("open routing socket");
217 		exit(EXIT_FAILURE);
218 	}
219 
220 	if (!inhibit_initial)
221 		run_initial_ups();
222 
223 	for (;;) {
224 		n = read(s, msg, sizeof msg);
225 		msgp = msg;
226 		for (msgp = msg; n > 0; n -= ((struct rt_msghdr*)msgp)->rtm_msglen, msgp += ((struct rt_msghdr*)msgp)->rtm_msglen) {
227 			dispatch(msgp, n);
228 
229 		}
230 	}
231 
232 	close(s);
233 	free_interfaces();
234 	closelog();
235 
236 	return EXIT_SUCCESS;
237 }
238 
239 static void
usage()240 usage()
241 {
242 	fprintf(stderr,
243 	    "usage:\n"
244 	    "\tifwatchd [-hiqv] [-A arrival-script] [-D departure-script]\n"
245 	    "\t\t  [-d down-script] [-u up-script]\n"
246 	    "\t\t  [-c carrier-script] [-n no-carrier-script] ifname(s)\n"
247 	    "\twhere:\n"
248 	    "\t -A <cmd> specify command to run on interface arrival event\n"
249 	    "\t -c <cmd> specify command to run on interface carrier-detect event\n"
250 	    "\t -D <cmd> specify command to run on interface departure event\n"
251 	    "\t -d <cmd> specify command to run on interface down event\n"
252 	    "\t -n <cmd> specify command to run on interface no-carrier-detect event\n"
253 	    "\t -h       show this help message\n"
254 	    "\t -i       no (!) initial run of the up script if the interface\n"
255 	    "\t          is already up on ifwatchd startup\n"
256 	    "\t -q       quiet mode, don't syslog informational messages\n"
257 	    "\t -u <cmd> specify command to run on interface up event\n"
258 	    "\t -v       verbose/debug output, don't run in background\n");
259 	exit(EXIT_FAILURE);
260 }
261 
262 static void
dispatch(void * msg,size_t len)263 dispatch(void *msg, size_t len)
264 {
265 	struct rt_msghdr *hd = msg;
266 	struct if_msghdr *ifmp;
267 	struct ifa_msghdr *ifam;
268 	enum event ev;
269 
270 	switch (hd->rtm_type) {
271 	case RTM_NEWADDR:
272 		ev = UP;
273 		goto work;
274 	case RTM_DELADDR:
275 		ev = DOWN;
276 		goto work;
277 	case RTM_IFANNOUNCE:
278 		rescan_interfaces();
279 		check_announce((struct if_announcemsghdr *)msg);
280 		return;
281 	case RTM_IFINFO:
282 		ifmp = (struct if_msghdr*)msg;
283 		check_carrier(ifmp->ifm_index, ifmp->ifm_data.ifi_link_state);
284 		return;
285 	case RTM_MISS:
286 		return;
287 	}
288 	if (verbose)
289 		printf("unknown message ignored\n");
290 	return;
291 
292 work:
293 	ifam = (struct ifa_msghdr *)msg;
294 	check_addrs((char *)(ifam + 1), ifam->ifam_addrs, ev);
295 }
296 
297 static void
check_addrs(cp,addrs,ev)298 check_addrs(cp, addrs, ev)
299 	char    *cp;
300 	int     addrs;
301 	enum event ev;
302 {
303 	struct sockaddr *sa, *ifa = NULL, *brd = NULL;
304 	char ifname_buf[IFNAMSIZ];
305 	const char *ifname;
306 	int ifndx = 0, i;
307 
308 	if (addrs == 0)
309 		return;
310 	for (i = 1; i; i <<= 1) {
311 		if (i & addrs) {
312 			sa = (struct sockaddr *)cp;
313 			if (i == RTA_IFP) {
314 				struct sockaddr_dl * li = (struct sockaddr_dl*)sa;
315 				ifndx = li->sdl_index;
316 				if (!find_interface(ifndx)) {
317 					if (verbose)
318 						printf("ignoring change on interface #%d\n", ifndx);
319 					return;
320 				}
321 			} else if (i == RTA_IFA) {
322 				ifa = sa;
323 			} else if (i == RTA_BRD) {
324 				brd = sa;
325 			}
326 			ADVANCE(cp, sa);
327 		}
328 	}
329 	if (ifa != NULL) {
330 		ifname = if_indextoname(ifndx, ifname_buf);
331 		if (ifname == NULL || ev < UP)
332 			invoke_script(ifa, brd, ev, ifndx, ifname);
333 		else if (ev == UP) {
334 			if (if_is_connected(ifname))
335 				invoke_script(ifa, brd, ev, ifndx, ifname);
336 		} else if (ev == DOWN) {
337 			if (if_is_not_connected(ifname))
338 				invoke_script(ifa, brd, ev, ifndx, ifname);
339 		}
340 	}
341 }
342 
343 static void
invoke_script(sa,dest,ev,ifindex,ifname_hint)344 invoke_script(sa, dest, ev, ifindex, ifname_hint)
345 	struct sockaddr *sa, *dest;
346 	enum event ev;
347 	int ifindex;
348 	const char *ifname_hint;
349 {
350 	char addr[NI_MAXHOST], daddr[NI_MAXHOST], ifname_buf[IFNAMSIZ];
351 	const char * volatile ifname;
352 	const char *script;
353 	int status;
354 
355 	if (sa != NULL && sa->sa_len == 0) {
356 		fprintf(stderr, "illegal socket address (sa_len == 0)\n");
357 		return;
358 	}
359 	if (sa != NULL && sa->sa_family == AF_INET6) {
360 		struct sockaddr_in6 sin6;
361 
362 		(void) memcpy(&sin6, (struct sockaddr_in6 *)sa, sizeof (sin6));
363 		if (IN6_IS_ADDR_LINKLOCAL(&sin6.sin6_addr))
364 			return;
365 	}
366 
367 	addr[0] = daddr[0] = 0;
368 	ifname = if_indextoname(ifindex, ifname_buf);
369 	ifname = ifname ? ifname : ifname_hint;
370 	if (ifname == NULL)
371 		return;
372 
373 	if (sa != NULL) {
374 		if (getnameinfo(sa, sa->sa_len, addr, sizeof addr, NULL, 0,
375 		    NI_NUMERICHOST)) {
376 			if (verbose)
377 				printf("getnameinfo failed\n");
378 			return;	/* this address can not be handled */
379 		}
380 	}
381 	if (dest != NULL) {
382 		if (getnameinfo(dest, dest->sa_len, daddr, sizeof daddr,
383 		    NULL, 0, NI_NUMERICHOST)) {
384 			if (verbose)
385 				printf("getnameinfo failed\n");
386 			return;	/* this address can not be handled */
387 		}
388 	}
389 
390 	script = *scripts[ev];
391 	if (script == NULL) return;
392 
393 	if (verbose)
394 		(void) printf("calling: %s %s %s %s %s %s\n",
395 		    script, ifname, DummyTTY, DummySpeed, addr, daddr);
396 	if (!quiet)
397 		syslog(LOG_INFO, "calling: %s %s %s %s %s %s\n",
398 		    script, ifname, DummyTTY, DummySpeed, addr, daddr);
399 
400 	switch (vfork()) {
401 	case -1:
402 		fprintf(stderr, "cannot fork\n");
403 		break;
404 	case 0:
405 		if (execl(script, script, ifname, DummyTTY, DummySpeed,
406 		    addr, daddr, NULL) == -1) {
407 			syslog(LOG_ERR, "could not execute \"%s\": %m",
408 			    script);
409 			perror(script);
410 		}
411 		_exit(EXIT_FAILURE);
412 	default:
413 		(void) wait(&status);
414 	}
415 }
416 
417 static void
list_interfaces(const char * ifnames)418 list_interfaces(const char *ifnames)
419 {
420 	char * names = strdup(ifnames);
421 	char * name, *lasts;
422 	static const char sep[] = " \t";
423 	struct interface_data * p;
424 
425 	for (name = strtok_r(names, sep, &lasts);
426 	    name != NULL;
427 	    name = strtok_r(NULL, sep, &lasts)) {
428 		p = malloc(sizeof(*p));
429 		SLIST_INSERT_HEAD(&ifs, p, next);
430 		p->last_carrier_status = -1;
431 		p->ifname = strdup(name);
432 		p->index = if_nametoindex(p->ifname);
433 		if (!quiet)
434 			syslog(LOG_INFO, "watching interface %s", p->ifname);
435 		if (verbose)
436 			printf("interface \"%s\" has index %d\n",
437 			    p->ifname, p->index);
438 	}
439 	free(names);
440 }
441 
442 static void
check_carrier(int if_index,int carrier_status)443 check_carrier(int if_index, int carrier_status)
444 {
445 	struct interface_data * p;
446 	enum event ev;
447 
448 	SLIST_FOREACH(p, &ifs, next)
449 		if (p->index == if_index)
450 			break;
451 
452 	if (p == NULL)
453 		return;
454 
455 	/*
456 	 * Treat it as an event worth handling if:
457 	 * - the carrier status changed, or
458 	 * - this is the first time we've been called, and
459 	 * inhibit_initial is not set
460 	 */
461 
462 	if ((carrier_status != p->last_carrier_status) ||
463 	    ((p->last_carrier_status == -1) && !inhibit_initial)) {
464 		switch (carrier_status) {
465 		case LINK_STATE_UP:
466 			ev = CARRIER;
467 			break;
468 		case LINK_STATE_DOWN:
469 			ev = NO_CARRIER;
470 			break;
471 		default:
472 			if (verbose)
473 				printf("unknown link status ignored\n");
474 			return;
475 		}
476 		invoke_script(NULL, NULL, ev, if_index, p->ifname);
477 		p->last_carrier_status = carrier_status;
478 	}
479 }
480 
481 static void
check_announce(struct if_announcemsghdr * ifan)482 check_announce(struct if_announcemsghdr *ifan)
483 {
484 	struct interface_data * p;
485 	const char *ifname = ifan->ifan_name;
486 
487 	SLIST_FOREACH(p, &ifs, next) {
488 		if (strcmp(p->ifname, ifname) == 0) {
489 			switch (ifan->ifan_what) {
490 			case IFAN_ARRIVAL:
491 				invoke_script(NULL, NULL, ARRIVAL, p->index,
492 				    NULL);
493 				break;
494 			case IFAN_DEPARTURE:
495 				invoke_script(NULL, NULL, DEPARTURE, p->index,
496 				    p->ifname);
497 				break;
498 			default:
499 				if (verbose)
500 					(void) printf("unknown announce: "
501 					    "what=%d\n", ifan->ifan_what);
502 				break;
503 			}
504 			return;
505 		}
506 	}
507 }
508 
rescan_interfaces()509 static void rescan_interfaces()
510 {
511 	struct interface_data * p;
512 
513 	SLIST_FOREACH(p, &ifs, next) {
514 		p->index = if_nametoindex(p->ifname);
515 		if (verbose)
516 			printf("interface \"%s\" has index %d\n", p->ifname,
517 			    p->index);
518 	}
519 }
520 
free_interfaces()521 static void free_interfaces()
522 {
523 	struct interface_data * p;
524 
525 	while (!SLIST_EMPTY(&ifs)) {
526 		p = SLIST_FIRST(&ifs);
527 		SLIST_REMOVE_HEAD(&ifs, next);
528 		free(p->ifname);
529 		free(p);
530 	}
531 }
532 
find_interface(index)533 static int find_interface(index)
534 	int index;
535 {
536 	struct interface_data * p;
537 
538 	SLIST_FOREACH(p, &ifs, next)
539 		if (p->index == index)
540 			return 1;
541 	return 0;
542 }
543 
run_initial_ups()544 static void run_initial_ups()
545 {
546 	struct interface_data * ifd;
547 	struct ifaddrs *res = NULL, *p;
548 #ifdef __NetBSD__
549 	int s;
550 
551 	s = socket(AF_INET, SOCK_DGRAM, 0);
552 	if (s < 0)
553 		return;
554 #endif
555 
556 	if (getifaddrs(&res) == 0) {
557 		for (p = res; p; p = p->ifa_next) {
558 			SLIST_FOREACH(ifd, &ifs, next) {
559 				if (strcmp(ifd->ifname, p->ifa_name) == 0)
560 					break;
561 			}
562 			if (ifd == NULL)
563 				continue;
564 
565 			if (p->ifa_addr && p->ifa_addr->sa_family == AF_LINK)
566 				invoke_script(NULL, NULL, ARRIVAL, ifd->index,
567 				    NULL);
568 
569 			if ((p->ifa_flags & IFF_UP) == 0)
570 				continue;
571 			if (p->ifa_addr == NULL)
572 				continue;
573 			if (p->ifa_addr->sa_family == AF_LINK) {
574 #ifdef __NetBSD__
575 				struct ifmediareq ifmr;
576 
577 				memset(&ifmr, 0, sizeof(ifmr));
578 				strlcpy(ifmr.ifm_name, ifd->ifname,
579 				    sizeof(ifmr.ifm_name));
580 				if (ioctl(s, SIOCGIFMEDIA, &ifmr) != -1
581 				    && (ifmr.ifm_status & IFM_AVALID)
582 				    && (ifmr.ifm_status & IFM_ACTIVE)) {
583 					invoke_script(NULL, NULL, CARRIER,
584 					    ifd->index, ifd->ifname);
585 					ifd->last_carrier_status =
586 					    LINK_STATE_UP;
587 				    }
588 #endif
589 				continue;
590 			}
591 			if (if_is_connected(ifd->ifname))
592 				invoke_script(p->ifa_addr, p->ifa_dstaddr, UP,
593 				    ifd->index, ifd->ifname);
594 		}
595 		freeifaddrs(res);
596 	}
597 #ifdef __NetBSD__
598 	close(s);
599 #endif
600 }
601 
602 #ifdef SPPP_IF_SUPPORT
603 /*
604  * Special case support for in-kernel PPP interfaces.
605  * If these are IFF_UP, but have not yet connected or completed authentication
606  * we don't want to call the up script in the initial interface scan (there
607  * will be an UP event generated later, when IPCP completes, anyway).
608  *
609  * If this is no if_spppsubr.c based interface, this ioctl just fails and we
610  * treat is as connected.
611  */
612 static int
check_is_connected(const char * ifname,int def_retval)613 check_is_connected(const char * ifname, int def_retval)
614 {
615 #ifdef __NetBSD__
616 	int s, err;
617 	struct spppstatus oldstatus;
618 	struct spppstatusncp status;
619 
620 	memset(&status, 0, sizeof status);
621 	strlcpy(status.ifname, ifname, sizeof status.ifname);
622 	memset(&oldstatus, 0, sizeof oldstatus);
623 	strlcpy(oldstatus.ifname, ifname, sizeof oldstatus.ifname);
624 
625 	s = socket(AF_INET, SOCK_DGRAM, 0);
626 	if (s < 0)
627 		return 1;	/* no idea how to handle this... */
628 	err = ioctl(s, SPPPGETSTATUSNCP, &status);
629 	if (err != 0) {
630 		err = ioctl(s, SPPPGETSTATUS, &oldstatus);
631 		if (err != 0) {
632 			/* not if_spppsubr.c based - return default */
633 			close(s);
634 			return def_retval;
635 		} else {
636 			/* can't query NCPs, so use default */
637 			status.phase = oldstatus.phase;
638 			status.ncpup = def_retval;
639 		}
640 	}
641 	close(s);
642 
643 	return status.phase == SPPP_PHASE_NETWORK && status.ncpup > 0;
644 #endif
645 #ifdef __OpenBSD__
646 	int s, res = -1;
647 	struct ifreq ifr;
648 	struct spppreq spr;
649 
650 	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
651 
652 	s = socket(AF_INET, SOCK_DGRAM, 0);
653 	if (s < 0)
654 		err(EX_UNAVAILABLE, "ifwatchd: socket");
655 
656 	spr.cmd = (int)SPPPIOGDEFS;
657 	ifr.ifr_data = (caddr_t)&spr;
658 
659 	if (ioctl(s, SIOCGIFGENERIC, &ifr) > -1)
660 		res = (spr.defs.pp_phase == PHASE_NETWORK);
661 	close(s);
662 
663 	return res;
664 #endif
665 }
666 #endif
667