xref: /freebsd/sbin/shutdown/shutdown.c (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
1 /*
2  * Copyright (c) 1988, 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if 0
31 #ifndef lint
32 static const char copyright[] =
33 "@(#) Copyright (c) 1988, 1990, 1993\n\
34 	The Regents of the University of California.  All rights reserved.\n";
35 #endif /* not lint */
36 
37 #ifndef lint
38 static char sccsid[] = "@(#)shutdown.c	8.4 (Berkeley) 4/28/95";
39 #endif /* not lint */
40 #endif
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/param.h>
45 #include <sys/time.h>
46 #include <sys/resource.h>
47 #include <sys/syslog.h>
48 
49 #include <ctype.h>
50 #include <err.h>
51 #include <errno.h>
52 #include <fcntl.h>
53 #include <paths.h>
54 #include <pwd.h>
55 #include <setjmp.h>
56 #include <signal.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 
62 #ifdef DEBUG
63 #undef _PATH_NOLOGIN
64 #define	_PATH_NOLOGIN	"./nologin"
65 #endif
66 
67 #define	H		*60*60
68 #define	M		*60
69 #define	S		*1
70 #define	NOLOG_TIME	5*60
71 static struct interval {
72 	int timeleft, timetowait;
73 } tlist[] = {
74 	{ 10 H,  5 H },
75 	{  5 H,  3 H },
76 	{  2 H,  1 H },
77 	{  1 H, 30 M },
78 	{ 30 M, 10 M },
79 	{ 20 M, 10 M },
80 	{ 10 M,  5 M },
81 	{  5 M,  3 M },
82 	{  2 M,  1 M },
83 	{  1 M, 30 S },
84 	{ 30 S, 30 S },
85 	{  0  ,  0   }
86 };
87 #undef H
88 #undef M
89 #undef S
90 
91 static time_t offset, shuttime;
92 static int docycle, dohalt, dopower, doreboot, killflg, mbuflen, oflag;
93 static char mbuf[BUFSIZ];
94 static const char *nosync, *whom;
95 
96 static void badtime(void);
97 static void die_you_gravy_sucking_pig_dog(void);
98 static void finish(int);
99 static void getoffset(char *);
100 static void loop(void);
101 static void nolog(void);
102 static void timeout(int);
103 static void timewarn(int);
104 static void usage(const char *);
105 
106 extern const char **environ;
107 
108 int
109 main(int argc, char **argv)
110 {
111 	char *p, *endp;
112 	struct passwd *pw;
113 	int arglen, ch, len, readstdin;
114 
115 #ifndef DEBUG
116 	if (geteuid())
117 		errx(1, "NOT super-user");
118 #endif
119 
120 	nosync = NULL;
121 	readstdin = 0;
122 
123 	/*
124 	 * Test for the special case where the utility is called as
125 	 * "poweroff", for which it runs 'shutdown -p now'.
126 	 */
127 	if ((p = strrchr(argv[0], '/')) == NULL)
128 		p = argv[0];
129 	else
130 		++p;
131 	if (strcmp(p, "poweroff") == 0) {
132 		if (getopt(argc, argv, "") != -1)
133 			usage((char *)NULL);
134 		argc -= optind;
135 		argv += optind;
136 		if (argc != 0)
137 			usage((char *)NULL);
138 		dopower = 1;
139 		offset = 0;
140 		(void)time(&shuttime);
141 		goto poweroff;
142 	}
143 
144 	while ((ch = getopt(argc, argv, "-chknopr")) != -1)
145 		switch (ch) {
146 		case '-':
147 			readstdin = 1;
148 			break;
149 		case 'c':
150 			docycle = 1;
151 			break;
152 		case 'h':
153 			dohalt = 1;
154 			break;
155 		case 'k':
156 			killflg = 1;
157 			break;
158 		case 'n':
159 			nosync = "-n";
160 			break;
161 		case 'o':
162 			oflag = 1;
163 			break;
164 		case 'p':
165 			dopower = 1;
166 			break;
167 		case 'r':
168 			doreboot = 1;
169 			break;
170 		case '?':
171 		default:
172 			usage((char *)NULL);
173 		}
174 	argc -= optind;
175 	argv += optind;
176 
177 	if (argc < 1)
178 		usage((char *)NULL);
179 
180 	if (killflg + doreboot + dohalt + dopower + docycle > 1)
181 		usage("incompatible switches -c, -h, -k, -p and -r");
182 
183 	if (oflag && !(dohalt || dopower || doreboot || docycle))
184 		usage("-o requires -c, -h, -p or -r");
185 
186 	if (nosync != NULL && !oflag)
187 		usage("-n requires -o");
188 
189 	getoffset(*argv++);
190 
191 poweroff:
192 	if (*argv) {
193 		for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
194 			arglen = strlen(*argv);
195 			if ((len -= arglen) <= 2)
196 				break;
197 			if (p != mbuf)
198 				*p++ = ' ';
199 			memmove(p, *argv, arglen);
200 			p += arglen;
201 		}
202 		*p = '\n';
203 		*++p = '\0';
204 	}
205 
206 	if (readstdin) {
207 		p = mbuf;
208 		endp = mbuf + sizeof(mbuf) - 2;
209 		for (;;) {
210 			if (!fgets(p, endp - p + 1, stdin))
211 				break;
212 			for (; *p &&  p < endp; ++p);
213 			if (p == endp) {
214 				*p = '\n';
215 				*++p = '\0';
216 				break;
217 			}
218 		}
219 	}
220 	mbuflen = strlen(mbuf);
221 
222 	if (offset)
223 		(void)printf("Shutdown at %.24s.\n", ctime(&shuttime));
224 	else
225 		(void)printf("Shutdown NOW!\n");
226 
227 	if (!(whom = getlogin()))
228 		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
229 
230 #ifdef DEBUG
231 	(void)putc('\n', stdout);
232 #else
233 	(void)setpriority(PRIO_PROCESS, 0, PRIO_MIN);
234 	{
235 		int forkpid;
236 
237 		forkpid = fork();
238 		if (forkpid == -1)
239 			err(1, "fork");
240 		if (forkpid)
241 			errx(0, "[pid %d]", forkpid);
242 	}
243 	setsid();
244 #endif
245 	openlog("shutdown", LOG_CONS, LOG_AUTH);
246 	loop();
247 	return(0);
248 }
249 
250 static void
251 loop(void)
252 {
253 	struct interval *tp;
254 	u_int sltime;
255 	int logged;
256 
257 	if (offset <= NOLOG_TIME) {
258 		logged = 1;
259 		nolog();
260 	}
261 	else
262 		logged = 0;
263 	tp = tlist;
264 	if (tp->timeleft < offset)
265 		(void)sleep((u_int)(offset - tp->timeleft));
266 	else {
267 		while (tp->timeleft && offset < tp->timeleft)
268 			++tp;
269 		/*
270 		 * Warn now, if going to sleep more than a fifth of
271 		 * the next wait time.
272 		 */
273 		if ((sltime = offset - tp->timeleft)) {
274 			if (sltime > (u_int)(tp->timetowait / 5))
275 				timewarn(offset);
276 			(void)sleep(sltime);
277 		}
278 	}
279 	for (;; ++tp) {
280 		timewarn(tp->timeleft);
281 		if (!logged && tp->timeleft <= NOLOG_TIME) {
282 			logged = 1;
283 			nolog();
284 		}
285 		(void)sleep((u_int)tp->timetowait);
286 		if (!tp->timeleft)
287 			break;
288 	}
289 	die_you_gravy_sucking_pig_dog();
290 }
291 
292 static jmp_buf alarmbuf;
293 
294 static const char *restricted_environ[] = {
295 	"PATH=" _PATH_STDPATH,
296 	NULL
297 };
298 
299 static void
300 timewarn(int timeleft)
301 {
302 	static int first;
303 	static char hostname[MAXHOSTNAMELEN + 1];
304 	FILE *pf;
305 	char wcmd[MAXPATHLEN + 4];
306 
307 	if (!first++)
308 		(void)gethostname(hostname, sizeof(hostname));
309 
310 	/* undoc -n option to wall suppresses normal wall banner */
311 	(void)snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
312 	environ = restricted_environ;
313 	if (!(pf = popen(wcmd, "w"))) {
314 		syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
315 		return;
316 	}
317 
318 	(void)fprintf(pf,
319 	    "\007*** %sSystem shutdown message from %s@%s ***\007\n",
320 	    timeleft ? "": "FINAL ", whom, hostname);
321 
322 	if (timeleft > 10*60)
323 		(void)fprintf(pf, "System going down at %5.5s\n\n",
324 		    ctime(&shuttime) + 11);
325 	else if (timeleft > 59)
326 		(void)fprintf(pf, "System going down in %d minute%s\n\n",
327 		    timeleft / 60, (timeleft > 60) ? "s" : "");
328 	else if (timeleft)
329 		(void)fprintf(pf, "System going down in %s30 seconds\n\n",
330 		    (offset > 0 && offset < 30 ? "less than " : ""));
331 	else
332 		(void)fprintf(pf, "System going down IMMEDIATELY\n\n");
333 
334 	if (mbuflen)
335 		(void)fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
336 
337 	/*
338 	 * play some games, just in case wall doesn't come back
339 	 * probably unnecessary, given that wall is careful.
340 	 */
341 	if (!setjmp(alarmbuf)) {
342 		(void)signal(SIGALRM, timeout);
343 		(void)alarm((u_int)30);
344 		(void)pclose(pf);
345 		(void)alarm((u_int)0);
346 		(void)signal(SIGALRM, SIG_DFL);
347 	}
348 }
349 
350 static void
351 timeout(int signo __unused)
352 {
353 	longjmp(alarmbuf, 1);
354 }
355 
356 static void
357 die_you_gravy_sucking_pig_dog(void)
358 {
359 	char *empty_environ[] = { NULL };
360 
361 	syslog(LOG_NOTICE, "%s by %s: %s",
362 	    doreboot ? "reboot" : dohalt ? "halt" : dopower ? "power-down" :
363 	    docycle ? "power-cycle" : "shutdown", whom, mbuf);
364 
365 	(void)printf("\r\nSystem shutdown time has arrived\007\007\r\n");
366 	if (killflg) {
367 		(void)printf("\rbut you'll have to do it yourself\r\n");
368 		exit(0);
369 	}
370 #ifdef DEBUG
371 	if (doreboot)
372 		(void)printf("reboot");
373 	else if (docycle)
374 		(void)printf("power-cycle");
375 	else if (dohalt)
376 		(void)printf("halt");
377 	else if (dopower)
378 		(void)printf("power-down");
379 	if (nosync != NULL)
380 		(void)printf(" no sync");
381 	(void)printf("\nkill -HUP 1\n");
382 #else
383 	if (!oflag) {
384 		(void)kill(1, doreboot ? SIGINT :	/* reboot */
385 			      dohalt ? SIGUSR1 :	/* halt */
386 			      dopower ? SIGUSR2 :	/* power-down */
387 			      docycle ? SIGWINCH :	/* power-cycle */
388 			      SIGTERM);			/* single-user */
389 	} else {
390 		if (doreboot) {
391 			execle(_PATH_REBOOT, "reboot", "-l", nosync,
392 				(char *)NULL, empty_environ);
393 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
394 				_PATH_REBOOT);
395 			warn(_PATH_REBOOT);
396 		}
397 		else if (dohalt) {
398 			execle(_PATH_HALT, "halt", "-l", nosync,
399 				(char *)NULL, empty_environ);
400 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
401 				_PATH_HALT);
402 			warn(_PATH_HALT);
403 		}
404 		else if (dopower) {
405 			execle(_PATH_HALT, "halt", "-l", "-p", nosync,
406 				(char *)NULL, empty_environ);
407 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
408 				_PATH_HALT);
409 			warn(_PATH_HALT);
410 		}
411 		else if (docycle) {
412 			execle(_PATH_HALT, "halt", "-l", "-c", nosync,
413 				(char *)NULL, empty_environ);
414 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
415 				_PATH_HALT);
416 			warn(_PATH_HALT);
417 		}
418 		(void)kill(1, SIGTERM);		/* to single-user */
419 	}
420 #endif
421 	finish(0);
422 }
423 
424 #define	ATOI2(p)	(p[0] - '0') * 10 + (p[1] - '0'); p += 2;
425 
426 static void
427 getoffset(char *timearg)
428 {
429 	struct tm *lt;
430 	char *p;
431 	time_t now;
432 	int this_year;
433 	char *timeunit;
434 
435 	(void)time(&now);
436 
437 	if (!strcasecmp(timearg, "now")) {		/* now */
438 		offset = 0;
439 		shuttime = now;
440 		return;
441 	}
442 
443 	if (*timearg == '+') {				/* +minutes */
444 		if (!isdigit(*++timearg))
445 			badtime();
446 		errno = 0;
447 		offset = strtol(timearg, &timeunit, 10);
448 		if (offset < 0 || offset == LONG_MAX || errno != 0)
449 			badtime();
450 		if (timeunit[0] == '\0' || strcasecmp(timeunit, "m") == 0 ||
451 		    strcasecmp(timeunit, "min") == 0 ||
452 		    strcasecmp(timeunit, "mins") == 0) {
453 			offset *= 60;
454 		} else if (strcasecmp(timeunit, "h") == 0 ||
455 		    strcasecmp(timeunit, "hour") == 0 ||
456 		    strcasecmp(timeunit, "hours") == 0) {
457 			offset *= 60 * 60;
458 		} else if (strcasecmp(timeunit, "s") == 0 ||
459 		    strcasecmp(timeunit, "sec") == 0 ||
460 		    strcasecmp(timeunit, "secs") == 0) {
461 			offset *= 1;
462 		} else {
463 			badtime();
464 		}
465 		shuttime = now + offset;
466 		return;
467 	}
468 
469 	/* handle hh:mm by getting rid of the colon */
470 	for (p = timearg; *p; ++p)
471 		if (!isascii(*p) || !isdigit(*p)) {
472 			if (*p == ':' && strlen(p) == 3) {
473 				p[0] = p[1];
474 				p[1] = p[2];
475 				p[2] = '\0';
476 			}
477 			else
478 				badtime();
479 		}
480 
481 	unsetenv("TZ");					/* OUR timezone */
482 	lt = localtime(&now);				/* current time val */
483 
484 	switch(strlen(timearg)) {
485 	case 10:
486 		this_year = lt->tm_year;
487 		lt->tm_year = ATOI2(timearg);
488 		/*
489 		 * check if the specified year is in the next century.
490 		 * allow for one year of user error as many people will
491 		 * enter n - 1 at the start of year n.
492 		 */
493 		if (lt->tm_year < (this_year % 100) - 1)
494 			lt->tm_year += 100;
495 		/* adjust for the year 2000 and beyond */
496 		lt->tm_year += (this_year - (this_year % 100));
497 		/* FALLTHROUGH */
498 	case 8:
499 		lt->tm_mon = ATOI2(timearg);
500 		if (--lt->tm_mon < 0 || lt->tm_mon > 11)
501 			badtime();
502 		/* FALLTHROUGH */
503 	case 6:
504 		lt->tm_mday = ATOI2(timearg);
505 		if (lt->tm_mday < 1 || lt->tm_mday > 31)
506 			badtime();
507 		/* FALLTHROUGH */
508 	case 4:
509 		lt->tm_hour = ATOI2(timearg);
510 		if (lt->tm_hour < 0 || lt->tm_hour > 23)
511 			badtime();
512 		lt->tm_min = ATOI2(timearg);
513 		if (lt->tm_min < 0 || lt->tm_min > 59)
514 			badtime();
515 		lt->tm_sec = 0;
516 		if ((shuttime = mktime(lt)) == -1)
517 			badtime();
518 		if ((offset = shuttime - now) < 0)
519 			errx(1, "that time is already past.");
520 		break;
521 	default:
522 		badtime();
523 	}
524 }
525 
526 #define	NOMSG	"\n\nNO LOGINS: System going down at "
527 static void
528 nolog(void)
529 {
530 	int logfd;
531 	char *ct;
532 
533 	(void)unlink(_PATH_NOLOGIN);	/* in case linked to another file */
534 	(void)signal(SIGINT, finish);
535 	(void)signal(SIGHUP, finish);
536 	(void)signal(SIGQUIT, finish);
537 	(void)signal(SIGTERM, finish);
538 	if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
539 	    0664)) >= 0) {
540 		(void)write(logfd, NOMSG, sizeof(NOMSG) - 1);
541 		ct = ctime(&shuttime);
542 		(void)write(logfd, ct + 11, 5);
543 		(void)write(logfd, "\n\n", 2);
544 		(void)write(logfd, mbuf, strlen(mbuf));
545 		(void)close(logfd);
546 	}
547 }
548 
549 static void
550 finish(int signo __unused)
551 {
552 	if (!killflg)
553 		(void)unlink(_PATH_NOLOGIN);
554 	exit(0);
555 }
556 
557 static void
558 badtime(void)
559 {
560 	errx(1, "bad time format");
561 }
562 
563 static void
564 usage(const char *cp)
565 {
566 	if (cp != NULL)
567 		warnx("%s", cp);
568 	(void)fprintf(stderr,
569 	    "usage: shutdown [-] [-c | -h | -p | -r | -k] [-o [-n]] time [warning-message ...]\n"
570 	    "       poweroff\n");
571 	exit(1);
572 }
573