xref: /openbsd/sbin/shutdown/shutdown.c (revision fd0cc40e)
1 /*	$OpenBSD: shutdown.c,v 1.45 2016/09/01 09:50:38 deraadt 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 #include <sys/types.h>
34 #include <sys/resource.h>
35 #include <sys/syslog.h>
36 #include <sys/types.h>
37 #include <sys/wait.h>
38 
39 #include <ctype.h>
40 #include <fcntl.h>
41 #include <sys/termios.h>
42 #include <pwd.h>
43 #include <setjmp.h>
44 #include <signal.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <time.h>
49 #include <unistd.h>
50 #include <limits.h>
51 #include <errno.h>
52 #include <err.h>
53 
54 #include "pathnames.h"
55 
56 #ifdef DEBUG
57 #undef _PATH_NOLOGIN
58 #define	_PATH_NOLOGIN	"./nologin"
59 #undef _PATH_FASTBOOT
60 #define	_PATH_FASTBOOT	"./fastboot"
61 #endif
62 
63 #define	H		*60*60
64 #define	M		*60
65 #define	S		*1
66 #define	NOLOG_TIME	5*60
67 struct interval {
68 	int timeleft, timetowait;
69 } tlist[] = {
70 	{ 10 H,  5 H },
71 	{  5 H,  3 H },
72 	{  2 H,  1 H },
73 	{  1 H, 30 M },
74 	{ 30 M, 10 M },
75 	{ 20 M, 10 M },
76 	{ 10 M,  5 M },
77 	{  5 M,  3 M },
78 	{  2 M,  1 M },
79 	{  1 M, 30 S },
80 	{ 30 S, 30 S },
81 	{    0,    0 }
82 };
83 #undef H
84 #undef M
85 #undef S
86 
87 static time_t offset, shuttime;
88 static int dofast, dohalt, doreboot, dopower, dodump, mbuflen, nosync;
89 static sig_atomic_t killflg;
90 static char *whom, mbuf[BUFSIZ];
91 
92 void badtime(void);
93 void __dead die_you_gravy_sucking_pig_dog(void);
94 void doitfast(void);
95 void __dead finish(int);
96 void getoffset(char *);
97 void __dead loop(void);
98 void nolog(void);
99 void timeout(int);
100 void timewarn(int);
101 void usage(void);
102 
103 int
104 main(int argc, char *argv[])
105 {
106 	int arglen, ch, len, readstdin = 0;
107 	struct passwd *pw;
108 	char *p, *endp;
109 	pid_t forkpid;
110 
111 	if (pledge("stdio rpath wpath cpath getpw tty id proc exec", NULL) == -1)
112 		err(1, "pledge");
113 
114 #ifndef DEBUG
115 	if (geteuid())
116 		errx(1, "NOT super-user");
117 #endif
118 	while ((ch = getopt(argc, argv, "dfhknpr-")) != -1)
119 		switch (ch) {
120 		case '-':
121 			readstdin = 1;
122 			break;
123 		case 'd':
124 			dodump = 1;
125 			break;
126 		case 'f':
127 			dofast = 1;
128 			break;
129 		case 'h':
130 			dohalt = 1;
131 			break;
132 		case 'k':
133 			killflg = 1;
134 			break;
135 		case 'n':
136 			nosync = 1;
137 			break;
138 		case 'p':
139 			dopower = 1;
140 			break;
141 		case 'r':
142 			doreboot = 1;
143 			break;
144 		default:
145 			usage();
146 		}
147 	argc -= optind;
148 	argv += optind;
149 
150 	if (argc < 1)
151 		usage();
152 
153 	if (dofast && nosync) {
154 		(void)fprintf(stderr,
155 		    "shutdown: incompatible switches -f and -n.\n");
156 		usage();
157 	}
158 	if (doreboot && dohalt) {
159 		(void)fprintf(stderr,
160 		    "shutdown: incompatible switches -h and -r.\n");
161 		usage();
162 	}
163 	if (doreboot && dopower) {
164 		(void)fprintf(stderr,
165 		    "shutdown: incompatible switches -p and -r.\n");
166 		usage();
167 	}
168 	getoffset(*argv++);
169 
170 	if (*argv) {
171 		for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
172 			arglen = strlen(*argv);
173 			if ((len -= arglen) <= 2)
174 				break;
175 			if (p != mbuf)
176 				*p++ = ' ';
177 			memcpy(p, *argv, arglen);
178 			p += arglen;
179 		}
180 		*p = '\n';
181 		*++p = '\0';
182 	}
183 
184 	if (readstdin) {
185 		p = mbuf;
186 		endp = mbuf + sizeof(mbuf) - 2;
187 		for (;;) {
188 			if (!fgets(p, endp - p + 1, stdin))
189 				break;
190 			for (; *p &&  p < endp; ++p)
191 				;
192 			if (p == endp) {
193 				*p = '\n';
194 				*++p = '\0';
195 				break;
196 			}
197 		}
198 	}
199 	mbuflen = strlen(mbuf);
200 
201 	if (offset) {
202 		char *ct = ctime(&shuttime);
203 
204 		if (ct)
205 			printf("Shutdown at %.24s.\n", ct);
206 		else
207 			printf("Shutdown soon.\n");
208 	} else
209 		(void)printf("Shutdown NOW!\n");
210 
211 	if (!(whom = getlogin()))
212 		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
213 
214 #ifdef DEBUG
215 	(void)putc('\n', stdout);
216 #else
217 	(void)setpriority(PRIO_PROCESS, 0, PRIO_MIN);
218 
219 	forkpid = fork();
220 	if (forkpid == -1)
221 		err(1, "fork");
222 	if (forkpid) {
223 		(void)printf("shutdown: [pid %ld]\n", (long)forkpid);
224 		exit(0);
225 	}
226 	setsid();
227 #endif
228 	openlog("shutdown", LOG_CONS, LOG_AUTH);
229 	loop();
230 	/* NOTREACHED */
231 }
232 
233 void
234 loop(void)
235 {
236 	struct interval *tp;
237 	u_int sltime;
238 	int logged;
239 
240 	if (offset <= NOLOG_TIME) {
241 		logged = 1;
242 		nolog();
243 	} else
244 		logged = 0;
245 	tp = tlist;
246 	if (tp->timeleft < offset)
247 		(void)sleep((u_int)(offset - tp->timeleft));
248 	else {
249 		while (offset < tp->timeleft)
250 			++tp;
251 		/*
252 		 * Warn now, if going to sleep more than a fifth of
253 		 * the next wait time.
254 		 */
255 		if ((sltime = offset - tp->timeleft)) {
256 			if (sltime > tp->timetowait / 5)
257 				timewarn(offset);
258 			(void)sleep(sltime);
259 		}
260 	}
261 	for (;; ++tp) {
262 		timewarn(tp->timeleft);
263 		if (!logged && tp->timeleft <= NOLOG_TIME) {
264 			logged = 1;
265 			nolog();
266 		}
267 		(void)sleep((u_int)tp->timetowait);
268 		if (!tp->timeleft)
269 			break;
270 	}
271 	die_you_gravy_sucking_pig_dog();
272 }
273 
274 static jmp_buf alarmbuf;
275 
276 static char *restricted_environ[] = {
277 	"PATH=" _PATH_STDPATH,
278 	NULL
279 };
280 
281 void
282 timewarn(int timeleft)
283 {
284 	static char hostname[HOST_NAME_MAX+1];
285 	char wcmd[PATH_MAX + 4];
286 	extern char **environ;
287 	static int first;
288 	FILE *pf;
289 
290 	if (!first++)
291 		(void)gethostname(hostname, sizeof(hostname));
292 
293 	/* undoc -n option to wall suppresses normal wall banner */
294 	(void)snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
295 	environ = restricted_environ;
296 	if (!(pf = popen(wcmd, "w"))) {
297 		syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
298 		return;
299 	}
300 
301 	(void)fprintf(pf,
302 	    "\007*** %sSystem shutdown message from %s@%s ***\007\n",
303 	    timeleft ? "": "FINAL ", whom, hostname);
304 
305 	if (timeleft > 10*60) {
306 		struct tm *tm = localtime(&shuttime);
307 
308 		fprintf(pf, "System going down at %d:%02d\n\n",
309 		    tm->tm_hour, tm->tm_min);
310 	} else if (timeleft > 59)
311 		(void)fprintf(pf, "System going down in %d minute%s\n\n",
312 		    timeleft / 60, (timeleft > 60) ? "s" : "");
313 	else if (timeleft)
314 		(void)fprintf(pf, "System going down in 30 seconds\n\n");
315 	else
316 		(void)fprintf(pf, "System going down IMMEDIATELY\n\n");
317 
318 	if (mbuflen)
319 		(void)fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
320 
321 	/*
322 	 * play some games, just in case wall doesn't come back
323 	 * probably unnecessary, given that wall is careful.
324 	 */
325 	if (!setjmp(alarmbuf)) {
326 		(void)signal(SIGALRM, timeout);
327 		(void)alarm((u_int)30);
328 		(void)pclose(pf);
329 		(void)alarm((u_int)0);
330 		(void)signal(SIGALRM, SIG_DFL);
331 	}
332 }
333 
334 void
335 timeout(int signo)
336 {
337 	longjmp(alarmbuf, 1);		/* XXX signal/longjmp resource leaks */
338 }
339 
340 void
341 die_you_gravy_sucking_pig_dog(void)
342 {
343 
344 	syslog(LOG_NOTICE, "%s by %s: %s",
345 	    doreboot ? "reboot" : dopower ? "power-down" : dohalt ? "halt" :
346 	    "shutdown", whom, mbuf);
347 	(void)sleep(2);
348 
349 	(void)printf("\r\nSystem shutdown time has arrived\007\007\r\n");
350 	if (killflg) {
351 		(void)printf("\rbut you'll have to do it yourself\r\n");
352 		finish(0);
353 	}
354 	if (dofast)
355 		doitfast();
356 
357 	if (pledge("stdio rpath wpath cpath tty id proc exec", NULL) == -1)
358 		err(1, "pledge");
359 
360 #ifdef DEBUG
361 	if (doreboot)
362 		(void)printf("reboot");
363 	else if (dopower)
364 		(void)printf("power-down");
365 	else if (dohalt)
366 		(void)printf("halt");
367 	if (nosync)
368 		(void)printf(" no sync");
369 	if (dofast)
370 		(void)printf(" no fsck");
371 	if (dodump)
372 		(void)printf(" with dump");
373 	(void)printf("\nkill -HUP 1\n");
374 #else
375 	if (dohalt || dopower || doreboot) {
376 		char *args[10];
377 		char **arg, *path;
378 
379 		if (pledge("stdio exec", NULL) == -1)
380 			err(1, "pledge");
381 
382 		arg = &args[0];
383 		if (doreboot) {
384 			path = _PATH_REBOOT;
385 			*arg++ = "reboot";
386 		} else {
387 			path = _PATH_HALT;
388 			*arg++ = "halt";
389 		}
390 		*arg++ = "-l";
391 		if (dopower)
392 			*arg++ = "-p";
393 		if (nosync)
394 			*arg++ = "-n";
395 		if (dodump)
396 			*arg++ = "-d";
397 		*arg++ = NULL;
398 		execve(path, args, NULL);
399 		syslog(LOG_ERR, "shutdown: can't exec %s: %m.", path);
400 		warn(path);
401 	}
402 	if (access(_PATH_RC, R_OK) != -1) {
403 		pid_t pid;
404 		struct termios t;
405 		int fd;
406 
407 		switch ((pid = fork())) {
408 		case -1:
409 			break;
410 		case 0:
411 			if (revoke(_PATH_CONSOLE) == -1)
412 				perror("revoke");
413 			if (setsid() == -1)
414 				perror("setsid");
415 			fd = open(_PATH_CONSOLE, O_RDWR);
416 			if (fd == -1)
417 				perror("open");
418 			dup2(fd, 0);
419 			dup2(fd, 1);
420 			dup2(fd, 2);
421 			if (fd > 2)
422 				close(fd);
423 
424 			/* At a minimum... */
425 			tcgetattr(0, &t);
426 			t.c_oflag |= (ONLCR | OPOST);
427 			tcsetattr(0, TCSANOW, &t);
428 
429 			execl(_PATH_BSHELL, "sh", _PATH_RC, "shutdown", (char *)NULL);
430 			_exit(1);
431 		default:
432 			waitpid(pid, NULL, 0);
433 		}
434 	}
435 	(void)kill(1, SIGTERM);		/* to single user */
436 #endif
437 	finish(0);
438 }
439 
440 #define	ATOI2(p)	(p[0] - '0') * 10 + (p[1] - '0'); p += 2;
441 
442 void
443 getoffset(char *timearg)
444 {
445 	struct tm *lt;
446 	int this_year;
447 	time_t now;
448 	char *p;
449 
450 	if (!strcasecmp(timearg, "now")) {		/* now */
451 		offset = 0;
452 		return;
453 	}
454 
455 	(void)time(&now);
456 	if (*timearg == '+') {				/* +minutes */
457 		const char *errstr;
458 
459 		offset = strtonum(++timearg, 0, INT_MAX, &errstr);
460 		if (errstr)
461 			badtime();
462 		offset *= 60;
463 		shuttime = now + offset;
464 		return;
465 	}
466 
467 	/* handle hh:mm by getting rid of the colon */
468 	for (p = timearg; *p; ++p) {
469 		if (!isascii((unsigned char)*p) || !isdigit((unsigned char)*p)) {
470 			if (*p == ':' && strlen(p) == 3) {
471 				p[0] = p[1];
472 				p[1] = p[2];
473 				p[2] = '\0';
474 			} else
475 				badtime();
476 		}
477 	}
478 
479 	unsetenv("TZ");					/* OUR timezone */
480 	lt = localtime(&now);				/* current time val */
481 
482 	switch (strlen(timearg)) {
483 	case 10:
484 		this_year = lt->tm_year;
485 		lt->tm_year = ATOI2(timearg);
486 		/*
487 		 * check if the specified year is in the next century.
488 		 * allow for one year of user error as many people will
489 		 * enter n - 1 at the start of year n.
490 		 */
491 		if (lt->tm_year < (this_year % 100) - 1)
492 			lt->tm_year += 100;
493 		/* adjust for the year 2000 and beyond */
494 		lt->tm_year += (this_year - (this_year % 100));
495 		/* FALLTHROUGH */
496 	case 8:
497 		lt->tm_mon = ATOI2(timearg);
498 		if (--lt->tm_mon < 0 || lt->tm_mon > 11)
499 			badtime();
500 		/* FALLTHROUGH */
501 	case 6:
502 		lt->tm_mday = ATOI2(timearg);
503 		if (lt->tm_mday < 1 || lt->tm_mday > 31)
504 			badtime();
505 		/* FALLTHROUGH */
506 	case 4:
507 		lt->tm_hour = ATOI2(timearg);
508 		if (lt->tm_hour < 0 || lt->tm_hour > 23)
509 			badtime();
510 		lt->tm_min = ATOI2(timearg);
511 		if (lt->tm_min < 0 || lt->tm_min > 59)
512 			badtime();
513 		lt->tm_sec = 0;
514 		if ((shuttime = mktime(lt)) == -1)
515 			badtime();
516 		if ((offset = shuttime - now) < 0)
517 			errx(1, "that time is already past.");
518 		break;
519 	default:
520 		badtime();
521 	}
522 }
523 
524 void
525 doitfast(void)
526 {
527 	int fastfd;
528 
529 	if ((fastfd = open(_PATH_FASTBOOT, O_WRONLY|O_CREAT|O_TRUNC,
530 	    0664)) >= 0) {
531 		dprintf(fastfd, "fastboot file for fsck\n");
532 		close(fastfd);
533 	}
534 }
535 
536 void
537 nolog(void)
538 {
539 	int logfd;
540 	struct tm *tm;
541 
542 	(void)unlink(_PATH_NOLOGIN);	/* in case linked to another file */
543 	(void)signal(SIGINT, finish);
544 	(void)signal(SIGHUP, finish);
545 	(void)signal(SIGQUIT, finish);
546 	(void)signal(SIGTERM, finish);
547 	tm = localtime(&shuttime);
548 	if (tm && (logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
549 	    0664)) >= 0) {
550 		dprintf(logfd,
551 		    "\n\nNO LOGINS: System going down at %d:%02d\n\n",
552 		    tm->tm_hour, tm->tm_min);
553 		close(logfd);
554 	}
555 }
556 
557 void
558 finish(int signo)
559 {
560 	if (!killflg)
561 		(void)unlink(_PATH_NOLOGIN);
562 	if (signo == 0)
563 		exit(0);
564 	else
565 		_exit(0);
566 }
567 
568 void
569 badtime(void)
570 {
571 	errx(1, "bad time format.");
572 }
573 
574 void
575 usage(void)
576 {
577 	fprintf(stderr,
578 	    "usage: shutdown [-] [-dfhknpr] time [warning-message ...]\n");
579 	exit(1);
580 }
581