shutdown.c revision 201180 
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 * 4. 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
32static 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
38static char sccsid[] = "@(#)shutdown.c	8.4 (Berkeley) 4/28/95";
39#endif /* not lint */
40#endif
41#include <sys/cdefs.h>
42__FBSDID("$FreeBSD: head/sbin/shutdown/shutdown.c 201180 2009-12-29 08:49:43Z ed $");
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 <fcntl.h>
52#include <paths.h>
53#include <pwd.h>
54#include <setjmp.h>
55#include <signal.h>
56#include <stdio.h>
57#include <stdlib.h>
58#include <string.h>
59#include <unistd.h>
60
61#ifdef DEBUG
62#undef _PATH_NOLOGIN
63#define	_PATH_NOLOGIN	"./nologin"
64#endif
65
66#define	H		*60*60
67#define	M		*60
68#define	S		*1
69#define	NOLOG_TIME	5*60
70struct interval {
71	int timeleft, timetowait;
72} tlist[] = {
73	{ 10 H,  5 H },
74	{  5 H,  3 H },
75	{  2 H,  1 H },
76	{  1 H, 30 M },
77	{ 30 M, 10 M },
78	{ 20 M, 10 M },
79	{ 10 M,  5 M },
80	{  5 M,  3 M },
81	{  2 M,  1 M },
82	{  1 M, 30 S },
83	{ 30 S, 30 S },
84	{  0  ,  0   }
85};
86#undef H
87#undef M
88#undef S
89
90static time_t offset, shuttime;
91static int dohalt, dopower, doreboot, killflg, mbuflen, oflag;
92static char mbuf[BUFSIZ];
93static const char *nosync, *whom;
94
95static void badtime(void);
96static void perform_shutdown(void);
97static void finish(int);
98static void getoffset(char *);
99static void loop(void);
100static void nolog(void);
101static void timeout(int);
102static void timewarn(int);
103static void usage(const char *);
104
105extern const char **environ;
106
107int
108main(int argc, char **argv)
109{
110	char *p, *endp;
111	struct passwd *pw;
112	int arglen, ch, len, readstdin;
113
114#ifndef DEBUG
115	if (geteuid())
116		errx(1, "NOT super-user");
117#endif
118	nosync = NULL;
119	readstdin = 0;
120	while ((ch = getopt(argc, argv, "-hknopr")) != -1)
121		switch (ch) {
122		case '-':
123			readstdin = 1;
124			break;
125		case 'h':
126			dohalt = 1;
127			break;
128		case 'k':
129			killflg = 1;
130			break;
131		case 'n':
132			nosync = "-n";
133			break;
134		case 'o':
135			oflag = 1;
136			break;
137		case 'p':
138			dopower = 1;
139			break;
140		case 'r':
141			doreboot = 1;
142			break;
143		case '?':
144		default:
145			usage((char *)NULL);
146		}
147	argc -= optind;
148	argv += optind;
149
150	if (argc < 1)
151		usage((char *)NULL);
152
153	if (killflg + doreboot + dohalt + dopower > 1)
154		usage("incompatible switches -h, -k, -p and -r");
155
156	if (oflag && !(dohalt || dopower || doreboot))
157		usage("-o requires -h, -p or -r");
158
159	if (nosync != NULL && !oflag)
160		usage("-n requires -o");
161
162	getoffset(*argv++);
163
164	if (*argv) {
165		for (p = mbuf, len = sizeof(mbuf); *argv; ++argv) {
166			arglen = strlen(*argv);
167			if ((len -= arglen) <= 2)
168				break;
169			if (p != mbuf)
170				*p++ = ' ';
171			memmove(p, *argv, arglen);
172			p += arglen;
173		}
174		*p = '\n';
175		*++p = '\0';
176	}
177
178	if (readstdin) {
179		p = mbuf;
180		endp = mbuf + sizeof(mbuf) - 2;
181		for (;;) {
182			if (!fgets(p, endp - p + 1, stdin))
183				break;
184			for (; *p &&  p < endp; ++p);
185			if (p == endp) {
186				*p = '\n';
187				*++p = '\0';
188				break;
189			}
190		}
191	}
192	mbuflen = strlen(mbuf);
193
194	if (offset)
195		(void)printf("Shutdown at %.24s.\n", ctime(&shuttime));
196	else
197		(void)printf("Shutdown NOW!\n");
198
199	if (!(whom = getlogin()))
200		whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
201
202#ifdef DEBUG
203	(void)putc('\n', stdout);
204#else
205	(void)setpriority(PRIO_PROCESS, 0, PRIO_MIN);
206	{
207		int forkpid;
208
209		forkpid = fork();
210		if (forkpid == -1)
211			err(1, "fork");
212		if (forkpid)
213			errx(0, "[pid %d]", forkpid);
214	}
215	setsid();
216#endif
217	openlog("shutdown", LOG_CONS, LOG_AUTH);
218	loop();
219	return(0);
220}
221
222static void
223loop(void)
224{
225	struct interval *tp;
226	u_int sltime;
227	int logged;
228
229	if (offset <= NOLOG_TIME) {
230		logged = 1;
231		nolog();
232	}
233	else
234		logged = 0;
235	tp = tlist;
236	if (tp->timeleft < offset)
237		(void)sleep((u_int)(offset - tp->timeleft));
238	else {
239		while (tp->timeleft && offset < tp->timeleft)
240			++tp;
241		/*
242		 * Warn now, if going to sleep more than a fifth of
243		 * the next wait time.
244		 */
245		if ((sltime = offset - tp->timeleft)) {
246			if (sltime > (u_int)(tp->timetowait / 5))
247				timewarn(offset);
248			(void)sleep(sltime);
249		}
250	}
251	for (;; ++tp) {
252		timewarn(tp->timeleft);
253		if (!logged && tp->timeleft <= NOLOG_TIME) {
254			logged = 1;
255			nolog();
256		}
257		(void)sleep((u_int)tp->timetowait);
258		if (!tp->timeleft)
259			break;
260	}
261	perform_shutdown();
262}
263
264static jmp_buf alarmbuf;
265
266static const char *restricted_environ[] = {
267	"PATH=" _PATH_STDPATH,
268	NULL
269};
270
271static void
272timewarn(int timeleft)
273{
274	static int first;
275	static char hostname[MAXHOSTNAMELEN + 1];
276	FILE *pf;
277	char wcmd[MAXPATHLEN + 4];
278
279	if (!first++)
280		(void)gethostname(hostname, sizeof(hostname));
281
282	/* undoc -n option to wall suppresses normal wall banner */
283	(void)snprintf(wcmd, sizeof(wcmd), "%s -n", _PATH_WALL);
284	environ = restricted_environ;
285	if (!(pf = popen(wcmd, "w"))) {
286		syslog(LOG_ERR, "shutdown: can't find %s: %m", _PATH_WALL);
287		return;
288	}
289
290	(void)fprintf(pf,
291	    "\007*** %sSystem shutdown message from %s@%s ***\007\n",
292	    timeleft ? "": "FINAL ", whom, hostname);
293
294	if (timeleft > 10*60)
295		(void)fprintf(pf, "System going down at %5.5s\n\n",
296		    ctime(&shuttime) + 11);
297	else if (timeleft > 59)
298		(void)fprintf(pf, "System going down in %d minute%s\n\n",
299		    timeleft / 60, (timeleft > 60) ? "s" : "");
300	else if (timeleft)
301		(void)fprintf(pf, "System going down in 30 seconds\n\n");
302	else
303		(void)fprintf(pf, "System going down IMMEDIATELY\n\n");
304
305	if (mbuflen)
306		(void)fwrite(mbuf, sizeof(*mbuf), mbuflen, pf);
307
308	/*
309	 * play some games, just in case wall doesn't come back
310	 * probably unnecessary, given that wall is careful.
311	 */
312	if (!setjmp(alarmbuf)) {
313		(void)signal(SIGALRM, timeout);
314		(void)alarm((u_int)30);
315		(void)pclose(pf);
316		(void)alarm((u_int)0);
317		(void)signal(SIGALRM, SIG_DFL);
318	}
319}
320
321static void
322timeout(int signo __unused)
323{
324	longjmp(alarmbuf, 1);
325}
326
327static void
328perform_shutdown(void)
329{
330	char *empty_environ[] = { NULL };
331
332	syslog(LOG_NOTICE, "%s by %s: %s",
333	    doreboot ? "reboot" : dohalt ? "halt" : dopower ? "power-down" :
334	    "shutdown", whom, mbuf);
335	(void)sleep(2);
336
337	(void)printf("\r\nSystem shutdown time has arrived\007\007\r\n");
338	if (killflg) {
339		(void)printf("\rbut you'll have to do it yourself\r\n");
340		exit(0);
341	}
342#ifdef DEBUG
343	if (doreboot)
344		(void)printf("reboot");
345	else if (dohalt)
346		(void)printf("halt");
347	else if (dopower)
348		(void)printf("power-down");
349	if (nosync != NULL)
350		(void)printf(" no sync");
351	(void)printf("\nkill -HUP 1\n");
352#else
353	if (!oflag) {
354		(void)kill(1, doreboot ? SIGINT :	/* reboot */
355			      dohalt ? SIGUSR1 :	/* halt */
356			      dopower ? SIGUSR2 :	/* power-down */
357			      SIGTERM);			/* single-user */
358	} else {
359		if (doreboot) {
360			execle(_PATH_REBOOT, "reboot", "-l", nosync,
361				(char *)NULL, empty_environ);
362			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
363				_PATH_REBOOT);
364			warn(_PATH_REBOOT);
365		}
366		else if (dohalt) {
367			execle(_PATH_HALT, "halt", "-l", nosync,
368				(char *)NULL, empty_environ);
369			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
370				_PATH_HALT);
371			warn(_PATH_HALT);
372		}
373		else if (dopower) {
374			execle(_PATH_HALT, "halt", "-l", "-p", nosync,
375				(char *)NULL, empty_environ);
376			syslog(LOG_ERR, "shutdown: can't exec %s: %m.",
377				_PATH_HALT);
378			warn(_PATH_HALT);
379		}
380		(void)kill(1, SIGTERM);		/* to single-user */
381	}
382#endif
383	finish(0);
384}
385
386#define	ATOI2(p)	(p[0] - '0') * 10 + (p[1] - '0'); p += 2;
387
388static void
389getoffset(char *timearg)
390{
391	struct tm *lt;
392	char *p;
393	time_t now;
394	int this_year;
395
396	(void)time(&now);
397
398	if (!strcasecmp(timearg, "now")) {		/* now */
399		offset = 0;
400		shuttime = now;
401		return;
402	}
403
404	if (*timearg == '+') {				/* +minutes */
405		if (!isdigit(*++timearg))
406			badtime();
407		if ((offset = atoi(timearg) * 60) < 0)
408			badtime();
409		shuttime = now + offset;
410		return;
411	}
412
413	/* handle hh:mm by getting rid of the colon */
414	for (p = timearg; *p; ++p)
415		if (!isascii(*p) || !isdigit(*p)) {
416			if (*p == ':' && strlen(p) == 3) {
417				p[0] = p[1];
418				p[1] = p[2];
419				p[2] = '\0';
420			}
421			else
422				badtime();
423		}
424
425	unsetenv("TZ");					/* OUR timezone */
426	lt = localtime(&now);				/* current time val */
427
428	switch(strlen(timearg)) {
429	case 10:
430		this_year = lt->tm_year;
431		lt->tm_year = ATOI2(timearg);
432		/*
433		 * check if the specified year is in the next century.
434		 * allow for one year of user error as many people will
435		 * enter n - 1 at the start of year n.
436		 */
437		if (lt->tm_year < (this_year % 100) - 1)
438			lt->tm_year += 100;
439		/* adjust for the year 2000 and beyond */
440		lt->tm_year += (this_year - (this_year % 100));
441		/* FALLTHROUGH */
442	case 8:
443		lt->tm_mon = ATOI2(timearg);
444		if (--lt->tm_mon < 0 || lt->tm_mon > 11)
445			badtime();
446		/* FALLTHROUGH */
447	case 6:
448		lt->tm_mday = ATOI2(timearg);
449		if (lt->tm_mday < 1 || lt->tm_mday > 31)
450			badtime();
451		/* FALLTHROUGH */
452	case 4:
453		lt->tm_hour = ATOI2(timearg);
454		if (lt->tm_hour < 0 || lt->tm_hour > 23)
455			badtime();
456		lt->tm_min = ATOI2(timearg);
457		if (lt->tm_min < 0 || lt->tm_min > 59)
458			badtime();
459		lt->tm_sec = 0;
460		if ((shuttime = mktime(lt)) == -1)
461			badtime();
462		if ((offset = shuttime - now) < 0)
463			errx(1, "that time is already past.");
464		break;
465	default:
466		badtime();
467	}
468}
469
470#define	NOMSG	"\n\nNO LOGINS: System going down at "
471static void
472nolog(void)
473{
474	int logfd;
475	char *ct;
476
477	(void)unlink(_PATH_NOLOGIN);	/* in case linked to another file */
478	(void)signal(SIGINT, finish);
479	(void)signal(SIGHUP, finish);
480	(void)signal(SIGQUIT, finish);
481	(void)signal(SIGTERM, finish);
482	if ((logfd = open(_PATH_NOLOGIN, O_WRONLY|O_CREAT|O_TRUNC,
483	    0664)) >= 0) {
484		(void)write(logfd, NOMSG, sizeof(NOMSG) - 1);
485		ct = ctime(&shuttime);
486		(void)write(logfd, ct + 11, 5);
487		(void)write(logfd, "\n\n", 2);
488		(void)write(logfd, mbuf, strlen(mbuf));
489		(void)close(logfd);
490	}
491}
492
493static void
494finish(int signo __unused)
495{
496	if (!killflg)
497		(void)unlink(_PATH_NOLOGIN);
498	exit(0);
499}
500
501static void
502badtime(void)
503{
504	errx(1, "bad time format");
505}
506
507static void
508usage(const char *cp)
509{
510	if (cp != NULL)
511		warnx("%s", cp);
512	(void)fprintf(stderr,
513	    "usage: shutdown [-] [-h | -p | -r | -k] [-o [-n]]"
514	    " time [warning-message ...]\n");
515	exit(1);
516}
517