xref: /openbsd-src/sbin/shutdown/shutdown.c (revision 2b0358df1d88d06ef4139321dd05bd5e05d91eaf)
1 /*	$OpenBSD: shutdown.c,v 1.34 2006/10/18 21:58:55 cloder Exp $	*/
2 /*	$NetBSD: shutdown.c,v 1.9 1995/03/18 15:01:09 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1988, 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static 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 #if 0
41 static char sccsid[] = "@(#)shutdown.c	8.2 (Berkeley) 2/16/94";
42 #else
43 static char rcsid[] = "$OpenBSD: shutdown.c,v 1.34 2006/10/18 21:58:55 cloder Exp $";
44 #endif
45 #endif /* not lint */
46 
47 #include <sys/param.h>
48 #include <sys/resource.h>
49 #include <sys/syslog.h>
50 #include <sys/types.h>
51 #include <sys/wait.h>
52 
53 #include <ctype.h>
54 #include <fcntl.h>
55 #include <sys/termios.h>
56 #include <pwd.h>
57 #include <setjmp.h>
58 #include <signal.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <time.h>
63 #include <tzfile.h>
64 #include <unistd.h>
65 #include <errno.h>
66 #include <err.h>
67 
68 #include "pathnames.h"
69 
70 #ifdef DEBUG
71 #undef _PATH_NOLOGIN
72 #define	_PATH_NOLOGIN	"./nologin"
73 #undef _PATH_FASTBOOT
74 #define	_PATH_FASTBOOT	"./fastboot"
75 #endif
76 
77 #define	H		*60*60
78 #define	M		*60
79 #define	S		*1
80 #define	NOLOG_TIME	5*60
81 struct interval {
82 	int timeleft, timetowait;
83 } tlist[] = {
84 	{ 10 H,  5 H },
85 	{  5 H,  3 H },
86 	{  2 H,  1 H },
87 	{  1 H, 30 M },
88 	{ 30 M, 10 M },
89 	{ 20 M, 10 M },
90 	{ 10 M,  5 M },
91 	{  5 M,  3 M },
92 	{  2 M,  1 M },
93 	{  1 M, 30 S },
94 	{ 30 S, 30 S },
95 	{    0,    0 }
96 };
97 #undef H
98 #undef M
99 #undef S
100 
101 static time_t offset, shuttime;
102 static int dofast, dohalt, doreboot, dopower, dodump, mbuflen, nosync;
103 static sig_atomic_t killflg;
104 static char *whom, mbuf[BUFSIZ];
105 
106 void badtime(void);
107 void __dead die_you_gravy_sucking_pig_dog(void);
108 void doitfast(void);
109 void __dead finish(int);
110 void getoffset(char *);
111 void __dead loop(void);
112 void nolog(void);
113 void timeout(int);
114 void timewarn(int);
115 void usage(void);
116 
117 int
118 main(int argc, char *argv[])
119 {
120 	int arglen, ch, len, readstdin = 0;
121 	struct passwd *pw;
122 	char *p, *endp;
123 	pid_t forkpid;
124 
125 #ifndef DEBUG
126 	if (geteuid())
127 		errx(1, "NOT super-user");
128 #endif
129 	while ((ch = getopt(argc, argv, "dfhknpr-")) != -1)
130 		switch (ch) {
131 		case '-':
132 			readstdin = 1;
133 			break;
134 		case 'd':
135 			dodump = 1;
136 			break;
137 		case 'f':
138 			dofast = 1;
139 			break;
140 		case 'h':
141 			dohalt = 1;
142 			break;
143 		case 'k':
144 			killflg = 1;
145 			break;
146 		case 'n':
147 			nosync = 1;
148 			break;
149 		case 'p':
150 			dopower = 1;
151 			break;
152 		case 'r':
153 			doreboot = 1;
154 			break;
155 		default:
156 			usage();
157 		}
158 	argc -= optind;
159 	argv += optind;
160 
161 	if (argc < 1)
162 		usage();
163 
164 	if (dofast && nosync) {
165 		(void)fprintf(stderr,
166 		    "shutdown: incompatible switches -f and -n.\n");
167 		usage();
168 	}
169 	if (doreboot && dohalt) {
170 		(void)fprintf(stderr,
171 		    "shutdown: incompatible switches -h and -r.\n");
172 		usage();
173 	}
174 	if (dopower && !dohalt) {
175 		(void)fprintf(stderr,
176 		    "shutdown: switch -p must be used with -h.\n");
177 		usage();
178 	}
179 	getoffset(*argv++);
180 
181 	if (*argv) {
182 		for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
183 			arglen = strlen(*argv);
184 			if ((len -= arglen) <= 2)
185 				break;
186 			if (p != mbuf)
187 				*p++ = ' ';
188 			memcpy(p, *argv, arglen);
189 			p += arglen;
190 		}
191 		*p = '\n';
192 		*++p = '\0';
193 	}
194 
195 	if (readstdin) {
196 		p = mbuf;
197 		endp = mbuf + sizeof(mbuf) - 2;
198 		for (;;) {
199 			if (!fgets(p, endp - p + 1, stdin))
200 				break;
201 			for (; *p &&  p < endp; ++p)
202 				;
203 			if (p == endp) {
204 				*p = '\n';
205 				*++p = '\0';
206 				break;
207 			}
208 		}
209 	}
210 	mbuflen = strlen(mbuf);
211 
212 	if (offset)
213 		(void)printf("Shutdown at %.24s.\n", ctime(&shuttime));
214 	else
215 		(void)printf("Shutdown NOW!\n");
216 
217 	if (!(whom = getlogin()))
218 		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
219 
220 #ifdef DEBUG
221 	(void)putc('\n', stdout);
222 #else
223 	(void)setpriority(PRIO_PROCESS, 0, PRIO_MIN);
224 
225 	forkpid = fork();
226 	if (forkpid == -1)
227 		err(1, "fork");
228 	if (forkpid) {
229 		(void)printf("shutdown: [pid %ld]\n", (long)forkpid);
230 		exit(0);
231 	}
232 	setsid();
233 #endif
234 	openlog("shutdown", LOG_CONS, LOG_AUTH);
235 	loop();
236 	/* NOTREACHED */
237 }
238 
239 void
240 loop(void)
241 {
242 	struct interval *tp;
243 	u_int sltime;
244 	int logged;
245 
246 	if (offset <= NOLOG_TIME) {
247 		logged = 1;
248 		nolog();
249 	} else
250 		logged = 0;
251 	tp = tlist;
252 	if (tp->timeleft < offset)
253 		(void)sleep((u_int)(offset - tp->timeleft));
254 	else {
255 		while (offset < tp->timeleft)
256 			++tp;
257 		/*
258 		 * Warn now, if going to sleep more than a fifth of
259 		 * the next wait time.
260 		 */
261 		if ((sltime = offset - tp->timeleft)) {
262 			if (sltime > tp->timetowait / 5)
263 				timewarn(offset);
264 			(void)sleep(sltime);
265 		}
266 	}
267 	for (;; ++tp) {
268 		timewarn(tp->timeleft);
269 		if (!logged && tp->timeleft <= NOLOG_TIME) {
270 			logged = 1;
271 			nolog();
272 		}
273 		(void)sleep((u_int)tp->timetowait);
274 		if (!tp->timeleft)
275 			break;
276 	}
277 	die_you_gravy_sucking_pig_dog();
278 }
279 
280 static jmp_buf alarmbuf;
281 
282 static char *restricted_environ[] = {
283 	"PATH=" _PATH_STDPATH,
284 	NULL
285 };
286 
287 void
288 timewarn(int timeleft)
289 {
290 	static char hostname[MAXHOSTNAMELEN];
291 	char wcmd[MAXPATHLEN + 4];
292 	extern char **environ;
293 	static int first;
294 	FILE *pf;
295 
296 	if (!first++)
297 		(void)gethostname(hostname, sizeof(hostname));
298 
299 	/* undoc -n option to wall suppresses normal wall banner */
300 	(void)snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
301 	environ = restricted_environ;
302 	if (!(pf = popen(wcmd, "w"))) {
303 		syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
304 		return;
305 	}
306 
307 	(void)fprintf(pf,
308 	    "\007*** %sSystem shutdown message from %s@%s ***\007\n",
309 	    timeleft ? "": "FINAL ", whom, hostname);
310 
311 	if (timeleft > 10*60)
312 		(void)fprintf(pf, "System going down at %5.5s\n\n",
313 		    ctime(&shuttime) + 11);
314 	else if (timeleft > 59)
315 		(void)fprintf(pf, "System going down in %d minute%s\n\n",
316 		    timeleft / 60, (timeleft > 60) ? "s" : "");
317 	else if (timeleft)
318 		(void)fprintf(pf, "System going down in 30 seconds\n\n");
319 	else
320 		(void)fprintf(pf, "System going down IMMEDIATELY\n\n");
321 
322 	if (mbuflen)
323 		(void)fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
324 
325 	/*
326 	 * play some games, just in case wall doesn't come back
327 	 * probably unecessary, given that wall is careful.
328 	 */
329 	if (!setjmp(alarmbuf)) {
330 		(void)signal(SIGALRM, timeout);
331 		(void)alarm((u_int)30);
332 		(void)pclose(pf);
333 		(void)alarm((u_int)0);
334 		(void)signal(SIGALRM, SIG_DFL);
335 	}
336 }
337 
338 void
339 timeout(int signo)
340 {
341 	longjmp(alarmbuf, 1);		/* XXX signal/longjmp resource leaks */
342 }
343 
344 void
345 die_you_gravy_sucking_pig_dog(void)
346 {
347 
348 	syslog(LOG_NOTICE, "%s by %s: %s",
349 	    doreboot ? "reboot" : dohalt ? "halt" : "shutdown", whom, mbuf);
350 	(void)sleep(2);
351 
352 	(void)printf("\r\nSystem shutdown time has arrived\007\007\r\n");
353 	if (killflg) {
354 		(void)printf("\rbut you'll have to do it yourself\r\n");
355 		finish(0);
356 	}
357 	if (dofast)
358 		doitfast();
359 #ifdef DEBUG
360 	if (doreboot)
361 		(void)printf("reboot");
362 	else if (dohalt)
363 		(void)printf("halt");
364 	if (nosync)
365 		(void)printf(" no sync");
366 	if (dofast)
367 		(void)printf(" no fsck");
368 	if (dodump)
369 		(void)printf(" with dump");
370 	(void)printf("\nkill -HUP 1\n");
371 #else
372 	if (doreboot) {
373 		execle(_PATH_REBOOT, "reboot", "-l",
374 		    (nosync ? "-n" : (dodump ? "-d" : NULL)),
375 		    (dodump ? "-d" : NULL), (char *)NULL, (char *)NULL);
376 		syslog(LOG_ERR, "shutdown: can't exec %s: %m.", _PATH_REBOOT);
377 		warn(_PATH_REBOOT);
378 	}
379 	else if (dohalt) {
380 		execle(_PATH_HALT, "halt", "-l",
381 		    (dopower ? "-p" : (nosync ? "-n" : (dodump ? "-d" : NULL))),
382 		    (nosync ? "-n" : (dodump ? "-d" : NULL)),
383 		    (dodump ? "-d" : NULL), (char *)NULL, (char *)NULL);
384 		syslog(LOG_ERR, "shutdown: can't exec %s: %m.", _PATH_HALT);
385 		warn(_PATH_HALT);
386 	}
387 	if (access(_PATH_RC, R_OK) != -1) {
388 		pid_t pid;
389 		struct termios t;
390 		int fd;
391 
392 		switch ((pid = fork())) {
393 		case -1:
394 			break;
395 		case 0:
396 			if (revoke(_PATH_CONSOLE) == -1)
397 				perror("revoke");
398 			if (setsid() == -1)
399 				perror("setsid");
400 			fd = open(_PATH_CONSOLE, O_RDWR);
401 			if (fd == -1)
402 				perror("open");
403 			dup2(fd, 0);
404 			dup2(fd, 1);
405 			dup2(fd, 2);
406 			if (fd > 2)
407 				close(fd);
408 
409 			/* At a minimum... */
410 			tcgetattr(0, &t);
411 			t.c_oflag |= (ONLCR | OPOST);
412 			tcsetattr(0, TCSANOW, &t);
413 
414 			execl(_PATH_BSHELL, "sh", _PATH_RC, "shutdown", (char *)NULL);
415 			_exit(1);
416 		default:
417 			waitpid(pid, NULL, 0);
418 		}
419 	}
420 	(void)kill(1, SIGTERM);		/* to single user */
421 #endif
422 	finish(0);
423 }
424 
425 #define	ATOI2(p)	(p[0] - '0') * 10 + (p[1] - '0'); p += 2;
426 
427 void
428 getoffset(char *timearg)
429 {
430 	struct tm *lt;
431 	int this_year;
432 	time_t now;
433 	char *p;
434 
435 	if (!strcasecmp(timearg, "now")) {		/* now */
436 		offset = 0;
437 		return;
438 	}
439 
440 	(void)time(&now);
441 	if (*timearg == '+') {				/* +minutes */
442 		if (!isdigit(*++timearg))
443 			badtime();
444 		offset = atoi(timearg) * 60;
445 		shuttime = now + offset;
446 		return;
447 	}
448 
449 	/* handle hh:mm by getting rid of the colon */
450 	for (p = timearg; *p; ++p) {
451 		if (!isascii(*p) || !isdigit(*p)) {
452 			if (*p == ':' && strlen(p) == 3) {
453 				p[0] = p[1];
454 				p[1] = p[2];
455 				p[2] = '\0';
456 			} else
457 				badtime();
458 		}
459 	}
460 
461 	unsetenv("TZ");					/* OUR timezone */
462 	lt = localtime(&now);				/* current time val */
463 
464 	switch (strlen(timearg)) {
465 	case 10:
466 		this_year = lt->tm_year;
467 		lt->tm_year = ATOI2(timearg);
468 		/*
469 		 * check if the specified year is in the next century.
470 		 * allow for one year of user error as many people will
471 		 * enter n - 1 at the start of year n.
472 		 */
473 		if (lt->tm_year < (this_year % 100) - 1)
474 			lt->tm_year += 100;
475 		/* adjust for the year 2000 and beyond */
476 		lt->tm_year += (this_year - (this_year % 100));
477 		/* FALLTHROUGH */
478 	case 8:
479 		lt->tm_mon = ATOI2(timearg);
480 		if (--lt->tm_mon < 0 || lt->tm_mon > 11)
481 			badtime();
482 		/* FALLTHROUGH */
483 	case 6:
484 		lt->tm_mday = ATOI2(timearg);
485 		if (lt->tm_mday < 1 || lt->tm_mday > 31)
486 			badtime();
487 		/* FALLTHROUGH */
488 	case 4:
489 		lt->tm_hour = ATOI2(timearg);
490 		if (lt->tm_hour < 0 || lt->tm_hour > 23)
491 			badtime();
492 		lt->tm_min = ATOI2(timearg);
493 		if (lt->tm_min < 0 || lt->tm_min > 59)
494 			badtime();
495 		lt->tm_sec = 0;
496 		if ((shuttime = mktime(lt)) == -1)
497 			badtime();
498 		if ((offset = shuttime - now) < 0)
499 			errx(1, "that time is already past.");
500 		break;
501 	default:
502 		badtime();
503 	}
504 }
505 
506 #define	FSMSG	"fastboot file for fsck\n"
507 void
508 doitfast(void)
509 {
510 	int fastfd;
511 
512 	if ((fastfd = open(_PATH_FASTBOOT, O_WRONLY|O_CREAT|O_TRUNC,
513 	    0664)) >= 0) {
514 		(void)write(fastfd, FSMSG, sizeof(FSMSG) - 1);
515 		(void)close(fastfd);
516 	}
517 }
518 
519 #define	NOMSG	"\n\nNO LOGINS: System going down at "
520 void
521 nolog(void)
522 {
523 	int logfd;
524 	char *ct;
525 
526 	(void)unlink(_PATH_NOLOGIN);	/* in case linked to another file */
527 	(void)signal(SIGINT, finish);
528 	(void)signal(SIGHUP, finish);
529 	(void)signal(SIGQUIT, finish);
530 	(void)signal(SIGTERM, finish);
531 	if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
532 	    0664)) >= 0) {
533 		(void)write(logfd, NOMSG, sizeof(NOMSG) - 1);
534 		ct = ctime(&shuttime);
535 		(void)write(logfd, ct + 11, 5);
536 		(void)write(logfd, "\n\n", 2);
537 		(void)write(logfd, mbuf, strlen(mbuf));
538 		(void)close(logfd);
539 	}
540 }
541 
542 void
543 finish(int signo)
544 {
545 	if (!killflg)
546 		(void)unlink(_PATH_NOLOGIN);
547 	if (signo == 0)
548 		exit(0);
549 	else
550 		_exit(0);
551 }
552 
553 void
554 badtime(void)
555 {
556 	errx(1, "bad time format.");
557 }
558 
559 void
560 usage(void)
561 {
562 	fprintf(stderr, "usage: shutdown [-] [-dfhknpr] time [warning-message ...]\n");
563 	exit(1);
564 }
565