xref: /freebsd/sbin/shutdown/shutdown.c (revision 565518046c9e721ea6ff608d44f1e89d344e5e02)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1988, 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #if 0
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1988, 1990, 1993\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 static char sccsid[] = "@(#)shutdown.c	8.4 (Berkeley) 4/28/95";
41 #endif /* not lint */
42 #endif
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <sys/param.h>
47 #include <sys/boottrace.h>
48 #include <sys/resource.h>
49 #include <sys/syslog.h>
50 #include <sys/time.h>
51 
52 #include <ctype.h>
53 #include <err.h>
54 #include <errno.h>
55 #include <fcntl.h>
56 #include <paths.h>
57 #include <pwd.h>
58 #include <setjmp.h>
59 #include <signal.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <unistd.h>
64 
65 #ifdef DEBUG
66 #undef _PATH_NOLOGIN
67 #define	_PATH_NOLOGIN	"./nologin"
68 #endif
69 
70 #define	H		*60*60
71 #define	M		*60
72 #define	S		*1
73 #define	NOLOG_TIME	5*60
74 static struct interval {
75 	int timeleft, timetowait;
76 } tlist[] = {
77 	{ 10 H,  5 H },
78 	{  5 H,  3 H },
79 	{  2 H,  1 H },
80 	{  1 H, 30 M },
81 	{ 30 M, 10 M },
82 	{ 20 M, 10 M },
83 	{ 10 M,  5 M },
84 	{  5 M,  3 M },
85 	{  2 M,  1 M },
86 	{  1 M, 30 S },
87 	{ 30 S, 30 S },
88 	{  0  ,  0   }
89 };
90 #undef H
91 #undef M
92 #undef S
93 
94 static time_t offset, shuttime;
95 static int docycle, dohalt, dopower, doreboot, killflg, mbuflen, oflag;
96 static char mbuf[BUFSIZ];
97 static const char *nosync, *whom;
98 
99 static void badtime(void);
100 static void die_you_gravy_sucking_pig_dog(void);
101 static void finish(int);
102 static void getoffset(char *);
103 static void loop(void);
104 static void nolog(void);
105 static void timeout(int);
106 static void timewarn(int);
107 static void usage(const char *);
108 
109 extern const char **environ;
110 
111 int
112 main(int argc, char **argv)
113 {
114 	char *p, *endp;
115 	struct passwd *pw;
116 	int arglen, ch, len, readstdin;
117 
118 #ifndef DEBUG
119 	if (geteuid())
120 		errx(1, "NOT super-user");
121 #endif
122 
123 	nosync = NULL;
124 	readstdin = 0;
125 
126 	/*
127 	 * Test for the special case where the utility is called as
128 	 * "poweroff", for which it runs 'shutdown -p now'.
129 	 */
130 	if ((p = strrchr(argv[0], '/')) == NULL)
131 		p = argv[0];
132 	else
133 		++p;
134 	if (strcmp(p, "poweroff") == 0) {
135 		if (getopt(argc, argv, "") != -1)
136 			usage((char *)NULL);
137 		argc -= optind;
138 		argv += optind;
139 		if (argc != 0)
140 			usage((char *)NULL);
141 		dopower = 1;
142 		offset = 0;
143 		(void)time(&shuttime);
144 		goto poweroff;
145 	}
146 
147 	while ((ch = getopt(argc, argv, "-chknopr")) != -1)
148 		switch (ch) {
149 		case '-':
150 			readstdin = 1;
151 			break;
152 		case 'c':
153 			docycle = 1;
154 			break;
155 		case 'h':
156 			dohalt = 1;
157 			break;
158 		case 'k':
159 			killflg = 1;
160 			break;
161 		case 'n':
162 			nosync = "-n";
163 			break;
164 		case 'o':
165 			oflag = 1;
166 			break;
167 		case 'p':
168 			dopower = 1;
169 			break;
170 		case 'r':
171 			doreboot = 1;
172 			break;
173 		case '?':
174 		default:
175 			usage((char *)NULL);
176 		}
177 	argc -= optind;
178 	argv += optind;
179 
180 	if (argc < 1)
181 		usage((char *)NULL);
182 
183 	if (killflg + doreboot + dohalt + dopower + docycle > 1)
184 		usage("incompatible switches -c, -h, -k, -p and -r");
185 
186 	if (oflag && !(dohalt || dopower || doreboot || docycle))
187 		usage("-o requires -c, -h, -p or -r");
188 
189 	if (nosync != NULL && !oflag)
190 		usage("-n requires -o");
191 
192 	getoffset(*argv++);
193 
194 poweroff:
195 	if (*argv) {
196 		for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
197 			arglen = strlen(*argv);
198 			if ((len -= arglen) <= 2)
199 				break;
200 			if (p != mbuf)
201 				*p++ = ' ';
202 			memmove(p, *argv, arglen);
203 			p += arglen;
204 		}
205 		*p = '\n';
206 		*++p = '\0';
207 	}
208 
209 	if (readstdin) {
210 		p = mbuf;
211 		endp = mbuf + sizeof(mbuf) - 2;
212 		for (;;) {
213 			if (!fgets(p, endp - p + 1, stdin))
214 				break;
215 			for (; *p &&  p < endp; ++p);
216 			if (p == endp) {
217 				*p = '\n';
218 				*++p = '\0';
219 				break;
220 			}
221 		}
222 	}
223 	mbuflen = strlen(mbuf);
224 
225 	if (offset) {
226 		BOOTTRACE("Shutdown at %s", ctime(&shuttime));
227 		(void)printf("Shutdown at %.24s.\n", ctime(&shuttime));
228 	} else {
229 		BOOTTRACE("Shutdown NOW!");
230 		(void)printf("Shutdown NOW!\n");
231 	}
232 
233 	if (!(whom = getlogin()))
234 		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
235 
236 #ifdef DEBUG
237 	(void)putc('\n', stdout);
238 #else
239 	(void)setpriority(PRIO_PROCESS, 0, PRIO_MIN);
240 	{
241 		int forkpid;
242 
243 		forkpid = fork();
244 		if (forkpid == -1)
245 			err(1, "fork");
246 		if (forkpid)
247 			errx(0, "[pid %d]", forkpid);
248 	}
249 	setsid();
250 #endif
251 	openlog("shutdown", LOG_CONS, LOG_AUTH);
252 	loop();
253 	return(0);
254 }
255 
256 static void
257 loop(void)
258 {
259 	struct interval *tp;
260 	u_int sltime;
261 	int logged;
262 
263 	if (offset <= NOLOG_TIME) {
264 		logged = 1;
265 		nolog();
266 	}
267 	else
268 		logged = 0;
269 	tp = tlist;
270 	if (tp->timeleft < offset)
271 		(void)sleep((u_int)(offset - tp->timeleft));
272 	else {
273 		while (tp->timeleft && offset < tp->timeleft)
274 			++tp;
275 		/*
276 		 * Warn now, if going to sleep more than a fifth of
277 		 * the next wait time.
278 		 */
279 		if ((sltime = offset - tp->timeleft)) {
280 			if (sltime > (u_int)(tp->timetowait / 5))
281 				timewarn(offset);
282 			(void)sleep(sltime);
283 		}
284 	}
285 	for (;; ++tp) {
286 		timewarn(tp->timeleft);
287 		if (!logged && tp->timeleft <= NOLOG_TIME) {
288 			logged = 1;
289 			nolog();
290 		}
291 		(void)sleep((u_int)tp->timetowait);
292 		if (!tp->timeleft)
293 			break;
294 	}
295 	die_you_gravy_sucking_pig_dog();
296 }
297 
298 static jmp_buf alarmbuf;
299 
300 static const char *restricted_environ[] = {
301 	"PATH=" _PATH_STDPATH,
302 	NULL
303 };
304 
305 static void
306 timewarn(int timeleft)
307 {
308 	static int first;
309 	static char hostname[MAXHOSTNAMELEN + 1];
310 	FILE *pf;
311 	char wcmd[MAXPATHLEN + 4];
312 
313 	if (!first++)
314 		(void)gethostname(hostname, sizeof(hostname));
315 
316 	/* undoc -n option to wall suppresses normal wall banner */
317 	(void)snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
318 	environ = restricted_environ;
319 	if (!(pf = popen(wcmd, "w"))) {
320 		syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
321 		return;
322 	}
323 
324 	(void)fprintf(pf,
325 	    "\007*** %sSystem shutdown message from %s@%s ***\007\n",
326 	    timeleft ? "": "FINAL ", whom, hostname);
327 
328 	if (timeleft > 10*60)
329 		(void)fprintf(pf, "System going down at %5.5s\n\n",
330 		    ctime(&shuttime) + 11);
331 	else if (timeleft > 59)
332 		(void)fprintf(pf, "System going down in %d minute%s\n\n",
333 		    timeleft / 60, (timeleft > 60) ? "s" : "");
334 	else if (timeleft)
335 		(void)fprintf(pf, "System going down in %s30 seconds\n\n",
336 		    (offset > 0 && offset < 30 ? "less than " : ""));
337 	else
338 		(void)fprintf(pf, "System going down IMMEDIATELY\n\n");
339 
340 	if (mbuflen)
341 		(void)fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
342 
343 	/*
344 	 * play some games, just in case wall doesn't come back
345 	 * probably unnecessary, given that wall is careful.
346 	 */
347 	if (!setjmp(alarmbuf)) {
348 		(void)signal(SIGALRM, timeout);
349 		(void)alarm((u_int)30);
350 		(void)pclose(pf);
351 		(void)alarm((u_int)0);
352 		(void)signal(SIGALRM, SIG_DFL);
353 	}
354 }
355 
356 static void
357 timeout(int signo __unused)
358 {
359 	longjmp(alarmbuf, 1);
360 }
361 
362 static void
363 die_you_gravy_sucking_pig_dog(void)
364 {
365 	char *empty_environ[] = { NULL };
366 
367 	BOOTTRACE("%s by %s",
368 	    doreboot ? "reboot" : dohalt ? "halt" : dopower ? "power-down" :
369 	    docycle ? "power-cycle" : "shutdown", whom);
370 	syslog(LOG_NOTICE, "%s by %s: %s",
371 	    doreboot ? "reboot" : dohalt ? "halt" : dopower ? "power-down" :
372 	    docycle ? "power-cycle" : "shutdown", whom, mbuf);
373 
374 	(void)printf("\r\nSystem shutdown time has arrived\007\007\r\n");
375 	if (killflg) {
376 		BOOTTRACE("fake shutdown...");
377 		(void)printf("\rbut you'll have to do it yourself\r\n");
378 		exit(0);
379 	}
380 #ifdef DEBUG
381 	if (doreboot)
382 		(void)printf("reboot");
383 	else if (docycle)
384 		(void)printf("power-cycle");
385 	else if (dohalt)
386 		(void)printf("halt");
387 	else if (dopower)
388 		(void)printf("power-down");
389 	if (nosync != NULL)
390 		(void)printf(" no sync");
391 	(void)printf("\nkill -HUP 1\n");
392 #else
393 	if (!oflag) {
394 		BOOTTRACE("signal to init(8)...");
395 		(void)kill(1, doreboot ? SIGINT :	/* reboot */
396 			      dohalt ? SIGUSR1 :	/* halt */
397 			      dopower ? SIGUSR2 :	/* power-down */
398 			      docycle ? SIGWINCH :	/* power-cycle */
399 			      SIGTERM);			/* single-user */
400 	} else {
401 		if (doreboot) {
402 			BOOTTRACE("exec reboot(8) -l...");
403 			execle(_PATH_REBOOT, "reboot", "-l", nosync,
404 				(char *)NULL, empty_environ);
405 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
406 				_PATH_REBOOT);
407 			warn(_PATH_REBOOT);
408 		}
409 		else if (dohalt) {
410 			BOOTTRACE("exec halt(8) -l...");
411 			execle(_PATH_HALT, "halt", "-l", nosync,
412 				(char *)NULL, empty_environ);
413 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
414 				_PATH_HALT);
415 			warn(_PATH_HALT);
416 		}
417 		else if (dopower) {
418 			BOOTTRACE("exec halt(8) -l -p...");
419 			execle(_PATH_HALT, "halt", "-l", "-p", nosync,
420 				(char *)NULL, empty_environ);
421 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
422 				_PATH_HALT);
423 			warn(_PATH_HALT);
424 		}
425 		else if (docycle) {
426 			execle(_PATH_HALT, "halt", "-l", "-c", nosync,
427 				(char *)NULL, empty_environ);
428 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
429 				_PATH_HALT);
430 			warn(_PATH_HALT);
431 		}
432 		BOOTTRACE("SIGTERM to init(8)...");
433 		(void)kill(1, SIGTERM);		/* to single-user */
434 	}
435 #endif
436 	finish(0);
437 }
438 
439 #define	ATOI2(p)	(p[0] - '0') * 10 + (p[1] - '0'); p += 2;
440 
441 static void
442 getoffset(char *timearg)
443 {
444 	struct tm *lt;
445 	char *p;
446 	time_t now;
447 	int maybe_today, this_year;
448 	char *timeunit;
449 
450 	(void)time(&now);
451 
452 	if (!strcasecmp(timearg, "now")) {		/* now */
453 		offset = 0;
454 		shuttime = now;
455 		return;
456 	}
457 
458 	if (*timearg == '+') {				/* +minutes */
459 		if (!isdigit(*++timearg))
460 			badtime();
461 		errno = 0;
462 		offset = strtol(timearg, &timeunit, 10);
463 		if (offset < 0 || offset == LONG_MAX || errno != 0)
464 			badtime();
465 		if (timeunit[0] == '\0' || strcasecmp(timeunit, "m") == 0 ||
466 		    strcasecmp(timeunit, "min") == 0 ||
467 		    strcasecmp(timeunit, "mins") == 0) {
468 			offset *= 60;
469 		} else if (strcasecmp(timeunit, "h") == 0 ||
470 		    strcasecmp(timeunit, "hour") == 0 ||
471 		    strcasecmp(timeunit, "hours") == 0) {
472 			offset *= 60 * 60;
473 		} else if (strcasecmp(timeunit, "s") == 0 ||
474 		    strcasecmp(timeunit, "sec") == 0 ||
475 		    strcasecmp(timeunit, "secs") == 0) {
476 			offset *= 1;
477 		} else {
478 			badtime();
479 		}
480 		shuttime = now + offset;
481 		return;
482 	}
483 
484 	/* handle hh:mm by getting rid of the colon */
485 	for (p = timearg; *p; ++p)
486 		if (!isascii(*p) || !isdigit(*p)) {
487 			if (*p == ':' && strlen(p) == 3) {
488 				p[0] = p[1];
489 				p[1] = p[2];
490 				p[2] = '\0';
491 			}
492 			else
493 				badtime();
494 		}
495 
496 	unsetenv("TZ");					/* OUR timezone */
497 	lt = localtime(&now);				/* current time val */
498 	maybe_today = 1;
499 
500 	switch(strlen(timearg)) {
501 	case 10:
502 		this_year = lt->tm_year;
503 		lt->tm_year = ATOI2(timearg);
504 		/*
505 		 * check if the specified year is in the next century.
506 		 * allow for one year of user error as many people will
507 		 * enter n - 1 at the start of year n.
508 		 */
509 		if (lt->tm_year < (this_year % 100) - 1)
510 			lt->tm_year += 100;
511 		/* adjust for the year 2000 and beyond */
512 		lt->tm_year += (this_year - (this_year % 100));
513 		/* FALLTHROUGH */
514 	case 8:
515 		lt->tm_mon = ATOI2(timearg);
516 		if (--lt->tm_mon < 0 || lt->tm_mon > 11)
517 			badtime();
518 		/* FALLTHROUGH */
519 	case 6:
520 		maybe_today = 0;
521 		lt->tm_mday = ATOI2(timearg);
522 		if (lt->tm_mday < 1 || lt->tm_mday > 31)
523 			badtime();
524 		/* FALLTHROUGH */
525 	case 4:
526 		lt->tm_hour = ATOI2(timearg);
527 		if (lt->tm_hour < 0 || lt->tm_hour > 23)
528 			badtime();
529 		lt->tm_min = ATOI2(timearg);
530 		if (lt->tm_min < 0 || lt->tm_min > 59)
531 			badtime();
532 		lt->tm_sec = 0;
533 		if ((shuttime = mktime(lt)) == -1)
534 			badtime();
535 
536 		if ((offset = shuttime - now) < 0) {
537 			if (!maybe_today)
538 				errx(1, "that time is already past.");
539 
540 			/*
541 			 * If the user only gave a time, assume that
542 			 * any time earlier than the current time
543 			 * was intended to be that time tomorrow.
544 			 */
545 			lt->tm_mday++;
546 			if ((shuttime = mktime(lt)) == -1)
547 				badtime();
548 			if ((offset = shuttime - now) < 0) {
549 				errx(1, "tomorrow is before today?");
550 			}
551 		}
552 		break;
553 	default:
554 		badtime();
555 	}
556 }
557 
558 #define	NOMSG	"\n\nNO LOGINS: System going down at "
559 static void
560 nolog(void)
561 {
562 	int logfd;
563 	char *ct;
564 
565 	(void)unlink(_PATH_NOLOGIN);	/* in case linked to another file */
566 	(void)signal(SIGINT, finish);
567 	(void)signal(SIGHUP, finish);
568 	(void)signal(SIGQUIT, finish);
569 	(void)signal(SIGTERM, finish);
570 	if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
571 	    0664)) >= 0) {
572 		(void)write(logfd, NOMSG, sizeof(NOMSG) - 1);
573 		ct = ctime(&shuttime);
574 		(void)write(logfd, ct + 11, 5);
575 		(void)write(logfd, "\n\n", 2);
576 		(void)write(logfd, mbuf, strlen(mbuf));
577 		(void)close(logfd);
578 	}
579 }
580 
581 static void
582 finish(int signo __unused)
583 {
584 	if (!killflg)
585 		(void)unlink(_PATH_NOLOGIN);
586 	exit(0);
587 }
588 
589 static void
590 badtime(void)
591 {
592 	errx(1, "bad time format");
593 }
594 
595 static void
596 usage(const char *cp)
597 {
598 	if (cp != NULL)
599 		warnx("%s", cp);
600 	(void)fprintf(stderr,
601 	    "usage: shutdown [-] [-c | -h | -p | -r | -k] [-o [-n]] time [warning-message ...]\n"
602 	    "       poweroff\n");
603 	exit(1);
604 }
605