shutdown.c revision 1.42 
1/*	$OpenBSD: shutdown.c,v 1.42 2015/04/18 18:28:37 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
67struct 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
87static time_t offset, shuttime;
88static int dofast, dohalt, doreboot, dopower, dodump, mbuflen, nosync;
89static sig_atomic_t killflg;
90static char *whom, mbuf[BUFSIZ];
91
92void badtime(void);
93void __dead die_you_gravy_sucking_pig_dog(void);
94void doitfast(void);
95void __dead finish(int);
96void getoffset(char *);
97void __dead loop(void);
98void nolog(void);
99void timeout(int);
100void timewarn(int);
101void usage(void);
102
103int
104main(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#ifndef DEBUG
112	if (geteuid())
113		errx(1, "NOT super-user");
114#endif
115	while ((ch = getopt(argc, argv, "dfhknpr-")) != -1)
116		switch (ch) {
117		case '-':
118			readstdin = 1;
119			break;
120		case 'd':
121			dodump = 1;
122			break;
123		case 'f':
124			dofast = 1;
125			break;
126		case 'h':
127			dohalt = 1;
128			break;
129		case 'k':
130			killflg = 1;
131			break;
132		case 'n':
133			nosync = 1;
134			break;
135		case 'p':
136			dopower = 1;
137			break;
138		case 'r':
139			doreboot = 1;
140			break;
141		default:
142			usage();
143		}
144	argc -= optind;
145	argv += optind;
146
147	if (argc < 1)
148		usage();
149
150	if (dofast && nosync) {
151		(void)fprintf(stderr,
152		    "shutdown: incompatible switches -f and -n.\n");
153		usage();
154	}
155	if (doreboot && dohalt) {
156		(void)fprintf(stderr,
157		    "shutdown: incompatible switches -h and -r.\n");
158		usage();
159	}
160	if (doreboot && dopower) {
161		(void)fprintf(stderr,
162		    "shutdown: incompatible switches -p and -r.\n");
163		usage();
164	}
165	getoffset(*argv++);
166
167	if (*argv) {
168		for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
169			arglen = strlen(*argv);
170			if ((len -= arglen) <= 2)
171				break;
172			if (p != mbuf)
173				*p++ = ' ';
174			memcpy(p, *argv, arglen);
175			p += arglen;
176		}
177		*p = '\n';
178		*++p = '\0';
179	}
180
181	if (readstdin) {
182		p = mbuf;
183		endp = mbuf + sizeof(mbuf) - 2;
184		for (;;) {
185			if (!fgets(p, endp - p + 1, stdin))
186				break;
187			for (; *p &&  p < endp; ++p)
188				;
189			if (p == endp) {
190				*p = '\n';
191				*++p = '\0';
192				break;
193			}
194		}
195	}
196	mbuflen = strlen(mbuf);
197
198	if (offset)
199		(void)printf("Shutdown at %.24s.\n", ctime(&shuttime));
200	else
201		(void)printf("Shutdown NOW!\n");
202
203	if (!(whom = getlogin()))
204		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
205
206#ifdef DEBUG
207	(void)putc('\n', stdout);
208#else
209	(void)setpriority(PRIO_PROCESS, 0, PRIO_MIN);
210
211	forkpid = fork();
212	if (forkpid == -1)
213		err(1, "fork");
214	if (forkpid) {
215		(void)printf("shutdown: [pid %ld]\n", (long)forkpid);
216		exit(0);
217	}
218	setsid();
219#endif
220	openlog("shutdown", LOG_CONS, LOG_AUTH);
221	loop();
222	/* NOTREACHED */
223}
224
225void
226loop(void)
227{
228	struct interval *tp;
229	u_int sltime;
230	int logged;
231
232	if (offset <= NOLOG_TIME) {
233		logged = 1;
234		nolog();
235	} else
236		logged = 0;
237	tp = tlist;
238	if (tp->timeleft < offset)
239		(void)sleep((u_int)(offset - tp->timeleft));
240	else {
241		while (offset < tp->timeleft)
242			++tp;
243		/*
244		 * Warn now, if going to sleep more than a fifth of
245		 * the next wait time.
246		 */
247		if ((sltime = offset - tp->timeleft)) {
248			if (sltime > tp->timetowait / 5)
249				timewarn(offset);
250			(void)sleep(sltime);
251		}
252	}
253	for (;; ++tp) {
254		timewarn(tp->timeleft);
255		if (!logged && tp->timeleft <= NOLOG_TIME) {
256			logged = 1;
257			nolog();
258		}
259		(void)sleep((u_int)tp->timetowait);
260		if (!tp->timeleft)
261			break;
262	}
263	die_you_gravy_sucking_pig_dog();
264}
265
266static jmp_buf alarmbuf;
267
268static char *restricted_environ[] = {
269	"PATH=" _PATH_STDPATH,
270	NULL
271};
272
273void
274timewarn(int timeleft)
275{
276	static char hostname[HOST_NAME_MAX+1];
277	char wcmd[PATH_MAX + 4];
278	extern char **environ;
279	static int first;
280	FILE *pf;
281
282	if (!first++)
283		(void)gethostname(hostname, sizeof(hostname));
284
285	/* undoc -n option to wall suppresses normal wall banner */
286	(void)snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
287	environ = restricted_environ;
288	if (!(pf = popen(wcmd, "w"))) {
289		syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
290		return;
291	}
292
293	(void)fprintf(pf,
294	    "\007*** %sSystem shutdown message from %s@%s ***\007\n",
295	    timeleft ? "": "FINAL ", whom, hostname);
296
297	if (timeleft > 10*60)
298		(void)fprintf(pf, "System going down at %5.5s\n\n",
299		    ctime(&shuttime) + 11);
300	else if (timeleft > 59)
301		(void)fprintf(pf, "System going down in %d minute%s\n\n",
302		    timeleft / 60, (timeleft > 60) ? "s" : "");
303	else if (timeleft)
304		(void)fprintf(pf, "System going down in 30 seconds\n\n");
305	else
306		(void)fprintf(pf, "System going down IMMEDIATELY\n\n");
307
308	if (mbuflen)
309		(void)fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
310
311	/*
312	 * play some games, just in case wall doesn't come back
313	 * probably unnecessary, given that wall is careful.
314	 */
315	if (!setjmp(alarmbuf)) {
316		(void)signal(SIGALRM, timeout);
317		(void)alarm((u_int)30);
318		(void)pclose(pf);
319		(void)alarm((u_int)0);
320		(void)signal(SIGALRM, SIG_DFL);
321	}
322}
323
324void
325timeout(int signo)
326{
327	longjmp(alarmbuf, 1);		/* XXX signal/longjmp resource leaks */
328}
329
330void
331die_you_gravy_sucking_pig_dog(void)
332{
333
334	syslog(LOG_NOTICE, "%s by %s: %s",
335	    doreboot ? "reboot" : dopower ? "power-down" : dohalt ? "halt" :
336	    "shutdown", whom, mbuf);
337	(void)sleep(2);
338
339	(void)printf("\r\nSystem shutdown time has arrived\007\007\r\n");
340	if (killflg) {
341		(void)printf("\rbut you'll have to do it yourself\r\n");
342		finish(0);
343	}
344	if (dofast)
345		doitfast();
346#ifdef DEBUG
347	if (doreboot)
348		(void)printf("reboot");
349	else if (dopower)
350		(void)printf("power-down");
351	else if (dohalt)
352		(void)printf("halt");
353	if (nosync)
354		(void)printf(" no sync");
355	if (dofast)
356		(void)printf(" no fsck");
357	if (dodump)
358		(void)printf(" with dump");
359	(void)printf("\nkill -HUP 1\n");
360#else
361	if (dohalt || dopower || doreboot) {
362		char *args[10];
363		char **arg, *path;
364
365		arg = &args[0];
366		if (doreboot) {
367			path = _PATH_REBOOT;
368			*arg++ = "reboot";
369		} else {
370			path = _PATH_HALT;
371			*arg++ = "halt";
372		}
373		*arg++ = "-l";
374		if (dopower)
375			*arg++ = "-p";
376		if (nosync)
377			*arg++ = "-n";
378		if (dodump)
379			*arg++ = "-d";
380		*arg++ = NULL;
381		execve(path, args, NULL);
382		syslog(LOG_ERR, "shutdown: can't exec %s: %m.", path);
383		warn(path);
384	}
385	if (access(_PATH_RC, R_OK) != -1) {
386		pid_t pid;
387		struct termios t;
388		int fd;
389
390		switch ((pid = fork())) {
391		case -1:
392			break;
393		case 0:
394			if (revoke(_PATH_CONSOLE) == -1)
395				perror("revoke");
396			if (setsid() == -1)
397				perror("setsid");
398			fd = open(_PATH_CONSOLE, O_RDWR);
399			if (fd == -1)
400				perror("open");
401			dup2(fd, 0);
402			dup2(fd, 1);
403			dup2(fd, 2);
404			if (fd > 2)
405				close(fd);
406
407			/* At a minimum... */
408			tcgetattr(0, &t);
409			t.c_oflag |= (ONLCR | OPOST);
410			tcsetattr(0, TCSANOW, &t);
411
412			execl(_PATH_BSHELL, "sh", _PATH_RC, "shutdown", (char *)NULL);
413			_exit(1);
414		default:
415			waitpid(pid, NULL, 0);
416		}
417	}
418	(void)kill(1, SIGTERM);		/* to single user */
419#endif
420	finish(0);
421}
422
423#define	ATOI2(p)	(p[0] - '0') * 10 + (p[1] - '0'); p += 2;
424
425void
426getoffset(char *timearg)
427{
428	struct tm *lt;
429	int this_year;
430	time_t now;
431	char *p;
432
433	if (!strcasecmp(timearg, "now")) {		/* now */
434		offset = 0;
435		return;
436	}
437
438	(void)time(&now);
439	if (*timearg == '+') {				/* +minutes */
440		const char *errstr;
441
442		offset = strtonum(++timearg, 0, INT_MAX, &errstr);
443		if (errstr);
444			badtime();
445		offset *= 60;
446		shuttime = now + offset;
447		return;
448	}
449
450	/* handle hh:mm by getting rid of the colon */
451	for (p = timearg; *p; ++p) {
452		if (!isascii((unsigned char)*p) || !isdigit((unsigned char)*p)) {
453			if (*p == ':' && strlen(p) == 3) {
454				p[0] = p[1];
455				p[1] = p[2];
456				p[2] = '\0';
457			} else
458				badtime();
459		}
460	}
461
462	unsetenv("TZ");					/* OUR timezone */
463	lt = localtime(&now);				/* current time val */
464
465	switch (strlen(timearg)) {
466	case 10:
467		this_year = lt->tm_year;
468		lt->tm_year = ATOI2(timearg);
469		/*
470		 * check if the specified year is in the next century.
471		 * allow for one year of user error as many people will
472		 * enter n - 1 at the start of year n.
473		 */
474		if (lt->tm_year < (this_year % 100) - 1)
475			lt->tm_year += 100;
476		/* adjust for the year 2000 and beyond */
477		lt->tm_year += (this_year - (this_year % 100));
478		/* FALLTHROUGH */
479	case 8:
480		lt->tm_mon = ATOI2(timearg);
481		if (--lt->tm_mon < 0 || lt->tm_mon > 11)
482			badtime();
483		/* FALLTHROUGH */
484	case 6:
485		lt->tm_mday = ATOI2(timearg);
486		if (lt->tm_mday < 1 || lt->tm_mday > 31)
487			badtime();
488		/* FALLTHROUGH */
489	case 4:
490		lt->tm_hour = ATOI2(timearg);
491		if (lt->tm_hour < 0 || lt->tm_hour > 23)
492			badtime();
493		lt->tm_min = ATOI2(timearg);
494		if (lt->tm_min < 0 || lt->tm_min > 59)
495			badtime();
496		lt->tm_sec = 0;
497		if ((shuttime = mktime(lt)) == -1)
498			badtime();
499		if ((offset = shuttime - now) < 0)
500			errx(1, "that time is already past.");
501		break;
502	default:
503		badtime();
504	}
505}
506
507#define	FSMSG	"fastboot file for fsck\n"
508void
509doitfast(void)
510{
511	int fastfd;
512
513	if ((fastfd = open(_PATH_FASTBOOT, O_WRONLY|O_CREAT|O_TRUNC,
514	    0664)) >= 0) {
515		(void)write(fastfd, FSMSG, sizeof(FSMSG) - 1);
516		(void)close(fastfd);
517	}
518}
519
520#define	NOMSG	"\n\nNO LOGINS: System going down at "
521void
522nolog(void)
523{
524	int logfd;
525	char *ct;
526
527	(void)unlink(_PATH_NOLOGIN);	/* in case linked to another file */
528	(void)signal(SIGINT, finish);
529	(void)signal(SIGHUP, finish);
530	(void)signal(SIGQUIT, finish);
531	(void)signal(SIGTERM, finish);
532	if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
533	    0664)) >= 0) {
534		(void)write(logfd, NOMSG, sizeof(NOMSG) - 1);
535		ct = ctime(&shuttime);
536		(void)write(logfd, ct + 11, 5);
537		(void)write(logfd, "\n\n", 2);
538		(void)write(logfd, mbuf, strlen(mbuf));
539		(void)close(logfd);
540	}
541}
542
543void
544finish(int signo)
545{
546	if (!killflg)
547		(void)unlink(_PATH_NOLOGIN);
548	if (signo == 0)
549		exit(0);
550	else
551		_exit(0);
552}
553
554void
555badtime(void)
556{
557	errx(1, "bad time format.");
558}
559
560void
561usage(void)
562{
563	fprintf(stderr,
564	    "usage: shutdown [-] [-dfhknpr] time [warning-message ...]\n");
565	exit(1);
566}
567