xref: /freebsd/sbin/shutdown/shutdown.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
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 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, "-hknopr")) != -1)
145 		switch (ch) {
146 		case '-':
147 			readstdin = 1;
148 			break;
149 		case 'h':
150 			dohalt = 1;
151 			break;
152 		case 'k':
153 			killflg = 1;
154 			break;
155 		case 'n':
156 			nosync = "-n";
157 			break;
158 		case 'o':
159 			oflag = 1;
160 			break;
161 		case 'p':
162 			dopower = 1;
163 			break;
164 		case 'r':
165 			doreboot = 1;
166 			break;
167 		case '?':
168 		default:
169 			usage((char *)NULL);
170 		}
171 	argc -= optind;
172 	argv += optind;
173 
174 	if (argc < 1)
175 		usage((char *)NULL);
176 
177 	if (killflg + doreboot + dohalt + dopower > 1)
178 		usage("incompatible switches -h, -k, -p and -r");
179 
180 	if (oflag && !(dohalt || dopower || doreboot))
181 		usage("-o requires -h, -p or -r");
182 
183 	if (nosync != NULL && !oflag)
184 		usage("-n requires -o");
185 
186 	getoffset(*argv++);
187 
188 poweroff:
189 	if (*argv) {
190 		for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
191 			arglen = strlen(*argv);
192 			if ((len -= arglen) <= 2)
193 				break;
194 			if (p != mbuf)
195 				*p++ = ' ';
196 			memmove(p, *argv, arglen);
197 			p += arglen;
198 		}
199 		*p = '\n';
200 		*++p = '\0';
201 	}
202 
203 	if (readstdin) {
204 		p = mbuf;
205 		endp = mbuf + sizeof(mbuf) - 2;
206 		for (;;) {
207 			if (!fgets(p, endp - p + 1, stdin))
208 				break;
209 			for (; *p &&  p < endp; ++p);
210 			if (p == endp) {
211 				*p = '\n';
212 				*++p = '\0';
213 				break;
214 			}
215 		}
216 	}
217 	mbuflen = strlen(mbuf);
218 
219 	if (offset)
220 		(void)printf("Shutdown at %.24s.\n", ctime(&shuttime));
221 	else
222 		(void)printf("Shutdown NOW!\n");
223 
224 	if (!(whom = getlogin()))
225 		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
226 
227 #ifdef DEBUG
228 	(void)putc('\n', stdout);
229 #else
230 	(void)setpriority(PRIO_PROCESS, 0, PRIO_MIN);
231 	{
232 		int forkpid;
233 
234 		forkpid = fork();
235 		if (forkpid == -1)
236 			err(1, "fork");
237 		if (forkpid)
238 			errx(0, "[pid %d]", forkpid);
239 	}
240 	setsid();
241 #endif
242 	openlog("shutdown", LOG_CONS, LOG_AUTH);
243 	loop();
244 	return(0);
245 }
246 
247 static void
248 loop(void)
249 {
250 	struct interval *tp;
251 	u_int sltime;
252 	int logged;
253 
254 	if (offset <= NOLOG_TIME) {
255 		logged = 1;
256 		nolog();
257 	}
258 	else
259 		logged = 0;
260 	tp = tlist;
261 	if (tp->timeleft < offset)
262 		(void)sleep((u_int)(offset - tp->timeleft));
263 	else {
264 		while (tp->timeleft && offset < tp->timeleft)
265 			++tp;
266 		/*
267 		 * Warn now, if going to sleep more than a fifth of
268 		 * the next wait time.
269 		 */
270 		if ((sltime = offset - tp->timeleft)) {
271 			if (sltime > (u_int)(tp->timetowait / 5))
272 				timewarn(offset);
273 			(void)sleep(sltime);
274 		}
275 	}
276 	for (;; ++tp) {
277 		timewarn(tp->timeleft);
278 		if (!logged && tp->timeleft <= NOLOG_TIME) {
279 			logged = 1;
280 			nolog();
281 		}
282 		(void)sleep((u_int)tp->timetowait);
283 		if (!tp->timeleft)
284 			break;
285 	}
286 	die_you_gravy_sucking_pig_dog();
287 }
288 
289 static jmp_buf alarmbuf;
290 
291 static const char *restricted_environ[] = {
292 	"PATH=" _PATH_STDPATH,
293 	NULL
294 };
295 
296 static void
297 timewarn(int timeleft)
298 {
299 	static int first;
300 	static char hostname[MAXHOSTNAMELEN + 1];
301 	FILE *pf;
302 	char wcmd[MAXPATHLEN + 4];
303 
304 	if (!first++)
305 		(void)gethostname(hostname, sizeof(hostname));
306 
307 	/* undoc -n option to wall suppresses normal wall banner */
308 	(void)snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
309 	environ = restricted_environ;
310 	if (!(pf = popen(wcmd, "w"))) {
311 		syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
312 		return;
313 	}
314 
315 	(void)fprintf(pf,
316 	    "\007*** %sSystem shutdown message from %s@%s ***\007\n",
317 	    timeleft ? "": "FINAL ", whom, hostname);
318 
319 	if (timeleft > 10*60)
320 		(void)fprintf(pf, "System going down at %5.5s\n\n",
321 		    ctime(&shuttime) + 11);
322 	else if (timeleft > 59)
323 		(void)fprintf(pf, "System going down in %d minute%s\n\n",
324 		    timeleft / 60, (timeleft > 60) ? "s" : "");
325 	else if (timeleft)
326 		(void)fprintf(pf, "System going down in %s30 seconds\n\n",
327 		    (offset > 0 && offset < 30 ? "less than " : ""));
328 	else
329 		(void)fprintf(pf, "System going down IMMEDIATELY\n\n");
330 
331 	if (mbuflen)
332 		(void)fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
333 
334 	/*
335 	 * play some games, just in case wall doesn't come back
336 	 * probably unnecessary, given that wall is careful.
337 	 */
338 	if (!setjmp(alarmbuf)) {
339 		(void)signal(SIGALRM, timeout);
340 		(void)alarm((u_int)30);
341 		(void)pclose(pf);
342 		(void)alarm((u_int)0);
343 		(void)signal(SIGALRM, SIG_DFL);
344 	}
345 }
346 
347 static void
348 timeout(int signo __unused)
349 {
350 	longjmp(alarmbuf, 1);
351 }
352 
353 static void
354 die_you_gravy_sucking_pig_dog(void)
355 {
356 	char *empty_environ[] = { NULL };
357 
358 	syslog(LOG_NOTICE, "%s by %s: %s",
359 	    doreboot ? "reboot" : dohalt ? "halt" : dopower ? "power-down" :
360 	    "shutdown", whom, mbuf);
361 
362 	(void)printf("\r\nSystem shutdown time has arrived\007\007\r\n");
363 	if (killflg) {
364 		(void)printf("\rbut you'll have to do it yourself\r\n");
365 		exit(0);
366 	}
367 #ifdef DEBUG
368 	if (doreboot)
369 		(void)printf("reboot");
370 	else if (dohalt)
371 		(void)printf("halt");
372 	else if (dopower)
373 		(void)printf("power-down");
374 	if (nosync != NULL)
375 		(void)printf(" no sync");
376 	(void)printf("\nkill -HUP 1\n");
377 #else
378 	if (!oflag) {
379 		(void)kill(1, doreboot ? SIGINT :	/* reboot */
380 			      dohalt ? SIGUSR1 :	/* halt */
381 			      dopower ? SIGUSR2 :	/* power-down */
382 			      SIGTERM);			/* single-user */
383 	} else {
384 		if (doreboot) {
385 			execle(_PATH_REBOOT, "reboot", "-l", nosync,
386 				(char *)NULL, empty_environ);
387 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
388 				_PATH_REBOOT);
389 			warn(_PATH_REBOOT);
390 		}
391 		else if (dohalt) {
392 			execle(_PATH_HALT, "halt", "-l", nosync,
393 				(char *)NULL, empty_environ);
394 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
395 				_PATH_HALT);
396 			warn(_PATH_HALT);
397 		}
398 		else if (dopower) {
399 			execle(_PATH_HALT, "halt", "-l", "-p", nosync,
400 				(char *)NULL, empty_environ);
401 			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
402 				_PATH_HALT);
403 			warn(_PATH_HALT);
404 		}
405 		(void)kill(1, SIGTERM);		/* to single-user */
406 	}
407 #endif
408 	finish(0);
409 }
410 
411 #define	ATOI2(p)	(p[0] - '0') * 10 + (p[1] - '0'); p += 2;
412 
413 static void
414 getoffset(char *timearg)
415 {
416 	struct tm *lt;
417 	char *p;
418 	time_t now;
419 	int this_year;
420 	char *timeunit;
421 
422 	(void)time(&now);
423 
424 	if (!strcasecmp(timearg, "now")) {		/* now */
425 		offset = 0;
426 		shuttime = now;
427 		return;
428 	}
429 
430 	if (*timearg == '+') {				/* +minutes */
431 		if (!isdigit(*++timearg))
432 			badtime();
433 		errno = 0;
434 		offset = strtol(timearg, &timeunit, 10);
435 		if (offset < 0 || offset == LONG_MAX || errno != 0)
436 			badtime();
437 		if (timeunit[0] == '\0' || strcasecmp(timeunit, "m") == 0 ||
438 		    strcasecmp(timeunit, "min") == 0 ||
439 		    strcasecmp(timeunit, "mins") == 0) {
440 			offset *= 60;
441 		} else if (strcasecmp(timeunit, "h") == 0 ||
442 		    strcasecmp(timeunit, "hour") == 0 ||
443 		    strcasecmp(timeunit, "hours") == 0) {
444 			offset *= 60 * 60;
445 		} else if (strcasecmp(timeunit, "s") == 0 ||
446 		    strcasecmp(timeunit, "sec") == 0 ||
447 		    strcasecmp(timeunit, "secs") == 0) {
448 			offset *= 1;
449 		} else {
450 			badtime();
451 		}
452 		shuttime = now + offset;
453 		return;
454 	}
455 
456 	/* handle hh:mm by getting rid of the colon */
457 	for (p = timearg; *p; ++p)
458 		if (!isascii(*p) || !isdigit(*p)) {
459 			if (*p == ':' && strlen(p) == 3) {
460 				p[0] = p[1];
461 				p[1] = p[2];
462 				p[2] = '\0';
463 			}
464 			else
465 				badtime();
466 		}
467 
468 	unsetenv("TZ");					/* OUR timezone */
469 	lt = localtime(&now);				/* current time val */
470 
471 	switch(strlen(timearg)) {
472 	case 10:
473 		this_year = lt->tm_year;
474 		lt->tm_year = ATOI2(timearg);
475 		/*
476 		 * check if the specified year is in the next century.
477 		 * allow for one year of user error as many people will
478 		 * enter n - 1 at the start of year n.
479 		 */
480 		if (lt->tm_year < (this_year % 100) - 1)
481 			lt->tm_year += 100;
482 		/* adjust for the year 2000 and beyond */
483 		lt->tm_year += (this_year - (this_year % 100));
484 		/* FALLTHROUGH */
485 	case 8:
486 		lt->tm_mon = ATOI2(timearg);
487 		if (--lt->tm_mon < 0 || lt->tm_mon > 11)
488 			badtime();
489 		/* FALLTHROUGH */
490 	case 6:
491 		lt->tm_mday = ATOI2(timearg);
492 		if (lt->tm_mday < 1 || lt->tm_mday > 31)
493 			badtime();
494 		/* FALLTHROUGH */
495 	case 4:
496 		lt->tm_hour = ATOI2(timearg);
497 		if (lt->tm_hour < 0 || lt->tm_hour > 23)
498 			badtime();
499 		lt->tm_min = ATOI2(timearg);
500 		if (lt->tm_min < 0 || lt->tm_min > 59)
501 			badtime();
502 		lt->tm_sec = 0;
503 		if ((shuttime = mktime(lt)) == -1)
504 			badtime();
505 		if ((offset = shuttime - now) < 0)
506 			errx(1, "that time is already past.");
507 		break;
508 	default:
509 		badtime();
510 	}
511 }
512 
513 #define	NOMSG	"\n\nNO LOGINS: System going down at "
514 static void
515 nolog(void)
516 {
517 	int logfd;
518 	char *ct;
519 
520 	(void)unlink(_PATH_NOLOGIN);	/* in case linked to another file */
521 	(void)signal(SIGINT, finish);
522 	(void)signal(SIGHUP, finish);
523 	(void)signal(SIGQUIT, finish);
524 	(void)signal(SIGTERM, finish);
525 	if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
526 	    0664)) >= 0) {
527 		(void)write(logfd, NOMSG, sizeof(NOMSG) - 1);
528 		ct = ctime(&shuttime);
529 		(void)write(logfd, ct + 11, 5);
530 		(void)write(logfd, "\n\n", 2);
531 		(void)write(logfd, mbuf, strlen(mbuf));
532 		(void)close(logfd);
533 	}
534 }
535 
536 static void
537 finish(int signo __unused)
538 {
539 	if (!killflg)
540 		(void)unlink(_PATH_NOLOGIN);
541 	exit(0);
542 }
543 
544 static void
545 badtime(void)
546 {
547 	errx(1, "bad time format");
548 }
549 
550 static void
551 usage(const char *cp)
552 {
553 	if (cp != NULL)
554 		warnx("%s", cp);
555 	(void)fprintf(stderr,
556 	    "usage: shutdown [-] [-h | -p | -r | -k] [-o [-n]] time [warning-message ...]\n"
557 	    "       poweroff\n");
558 	exit(1);
559 }
560