xref: /openbsd/usr.bin/at/at.c (revision a6445c1d)
1 /*	$OpenBSD: at.c,v 1.64 2014/10/08 03:56:52 doug Exp $	*/
2 
3 /*
4  *  at.c : Put file into atrun queue
5  *  Copyright (C) 1993, 1994  Thomas Koenig
6  *
7  *  Atrun & Atq modifications
8  *  Copyright (C) 1993  David Parsons
9  *
10  *  Traditional BSD behavior and other significant modifications
11  *  Copyright (C) 2002-2003  Todd C. Miller
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. The name of the author(s) may not be used to endorse or promote
19  *    products derived from this software without specific prior written
20  *    permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #define	MAIN_PROGRAM
35 
36 #include "cron.h"
37 #include "at.h"
38 #include "privs.h"
39 #include <limits.h>
40 
41 #define ALARMC 10		/* Number of seconds to wait for timeout */
42 #define TIMESIZE 50		/* Size of buffer passed to strftime() */
43 
44 /* Variables to remove from the job's environment. */
45 char *no_export[] =
46 {
47 	"TERM", "TERMCAP", "DISPLAY", "_", "SHELLOPTS", "BASH_VERSINFO",
48 	"EUID", "GROUPS", "PPID", "UID", "SSH_AUTH_SOCK", "SSH_AGENT_PID",
49 };
50 
51 int program = AT;		/* default program mode */
52 char atfile[MAX_FNAME];		/* path to the at spool file */
53 int fcreated;			/* whether or not we created the file yet */
54 char atqueue = 0;		/* which queue to examine for jobs (atq) */
55 char vflag = 0;			/* show completed but unremoved jobs (atq) */
56 char force = 0;			/* suppress errors (atrm) */
57 char interactive = 0;		/* interactive mode (atrm) */
58 static int send_mail = 0;	/* whether we are sending mail */
59 
60 static void sigc(int);
61 static void alarmc(int);
62 static void writefile(const char *, time_t, char);
63 static void list_jobs(int, char **, int, int);
64 static time_t ttime(char *);
65 static int check_permission(void);
66 static __dead void panic(const char *);
67 static void perr(const char *);
68 static void perr2(const char *, const char *);
69 static __dead void usage(void);
70 static int rmok(long long);
71 time_t parsetime(int, char **);
72 
73 /*
74  * Something fatal has happened, print error message and exit.
75  */
76 static __dead void
77 panic(const char *a)
78 {
79 	(void)fprintf(stderr, "%s: %s\n", ProgramName, a);
80 	if (fcreated) {
81 		PRIV_START;
82 		unlink(atfile);
83 		PRIV_END;
84 	}
85 
86 	exit(EXIT_FAILURE);
87 }
88 
89 /*
90  * Two-parameter version of panic().
91  */
92 static __dead void
93 panic2(const char *a, const char *b)
94 {
95 	(void)fprintf(stderr, "%s: %s%s\n", ProgramName, a, b);
96 	if (fcreated) {
97 		PRIV_START;
98 		unlink(atfile);
99 		PRIV_END;
100 	}
101 
102 	exit(EXIT_FAILURE);
103 }
104 
105 /*
106  * Some operating system error; print error message and exit.
107  */
108 static __dead void
109 perr(const char *a)
110 {
111 	if (!force)
112 		perror(a);
113 	if (fcreated) {
114 		PRIV_START;
115 		unlink(atfile);
116 		PRIV_END;
117 	}
118 
119 	exit(EXIT_FAILURE);
120 }
121 
122 /*
123  * Two-parameter version of perr().
124  */
125 static __dead void
126 perr2(const char *a, const char *b)
127 {
128 	if (!force)
129 		(void)fputs(a, stderr);
130 	perr(b);
131 }
132 
133 /* ARGSUSED */
134 static void
135 sigc(int signo)
136 {
137 	/* If the user presses ^C, remove the spool file and exit. */
138 	if (fcreated) {
139 		PRIV_START;
140 		(void)unlink(atfile);
141 		PRIV_END;
142 	}
143 
144 	_exit(EXIT_FAILURE);
145 }
146 
147 /* ARGSUSED */
148 static void
149 alarmc(int signo)
150 {
151 	/* just return */
152 }
153 
154 static int
155 newjob(time_t runtimer, int queue)
156 {
157 	int fd, i;
158 
159 	/*
160 	 * If we have a collision, try shifting the time by up to
161 	 * two minutes.  Perhaps it would be better to try different
162 	 * queues instead...
163 	 */
164 	for (i = 0; i < 120; i++) {
165 		snprintf(atfile, sizeof(atfile), "%s/%lld.%c", AT_DIR,
166 		    (long long)runtimer, queue);
167 		fd = open(atfile, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR);
168 		if (fd >= 0)
169 			return (fd);
170 		runtimer++;
171 	}
172 	return (-1);
173 }
174 
175 /*
176  * This does most of the work if at or batch are invoked for
177  * writing a job.
178  */
179 static void
180 writefile(const char *cwd, time_t runtimer, char queue)
181 {
182 	const char *ap;
183 	char *mailname, *shell;
184 	char timestr[TIMESIZE];
185 	struct passwd *pass_entry;
186 	struct tm runtime;
187 	int fdes, lockdes, fd2;
188 	FILE *fp;
189 	struct sigaction act;
190 	char **atenv;
191 	int ch;
192 	mode_t cmask;
193 	extern char **environ;
194 
195 	(void)setlocale(LC_TIME, "");
196 
197 	/*
198 	 * Install the signal handler for SIGINT; terminate after removing the
199 	 * spool file if necessary
200 	 */
201 	bzero(&act, sizeof act);
202 	act.sa_handler = sigc;
203 	sigemptyset(&act.sa_mask);
204 	act.sa_flags = 0;
205 	sigaction(SIGINT, &act, NULL);
206 
207 	PRIV_START;
208 
209 	if ((lockdes = open(AT_DIR, O_RDONLY, 0)) < 0)
210 		perr("Cannot open jobs dir");
211 
212 	/*
213 	 * Lock the jobs dir so we don't have to worry about someone
214 	 * else grabbing a file name out from under us.
215 	 * Set an alarm so we don't sleep forever waiting on the lock.
216 	 * If we don't succeed with ALARMC seconds, something is wrong...
217 	 */
218 	bzero(&act, sizeof act);
219 	act.sa_handler = alarmc;
220 	sigemptyset(&act.sa_mask);
221 #ifdef SA_INTERRUPT
222 	act.sa_flags = SA_INTERRUPT;
223 #endif
224 	sigaction(SIGALRM, &act, NULL);
225 	alarm(ALARMC);
226 	ch = flock(lockdes, LOCK_EX);
227 	alarm(0);
228 	if (ch != 0)
229 		panic("Unable to lock jobs dir");
230 
231 	/*
232 	 * Create the file. The x bit is only going to be set after it has
233 	 * been completely written out, to make sure it is not executed in
234 	 * the meantime.  To make sure they do not get deleted, turn off
235 	 * their r bit.  Yes, this is a kluge.
236 	 */
237 	cmask = umask(S_IRUSR | S_IWUSR | S_IXUSR);
238 	if ((fdes = newjob(runtimer, queue)) == -1)
239 		perr("Cannot create atjob file");
240 
241 	if ((fd2 = dup(fdes)) < 0)
242 		perr("Error in dup() of job file");
243 
244 	if (fchown(fd2, real_uid, real_gid) != 0)
245 		perr("Cannot give away file");
246 
247 	PRIV_END;
248 
249 	/*
250 	 * We've successfully created the file; let's set the flag so it
251 	 * gets removed in case of an interrupt or error.
252 	 */
253 	fcreated = 1;
254 
255 	/* Now we can release the lock, so other people can access it */
256 	(void)close(lockdes);
257 
258 	if ((fp = fdopen(fdes, "w")) == NULL)
259 		panic("Cannot reopen atjob file");
260 
261 	/*
262 	 * Get the userid to mail to, first by trying getlogin(), which asks
263 	 * the kernel, then from $LOGNAME or $USER, finally from getpwuid().
264 	 */
265 	mailname = getlogin();
266 	if (mailname == NULL && (mailname = getenv("LOGNAME")) == NULL)
267 		mailname = getenv("USER");
268 
269 	if ((mailname == NULL) || (mailname[0] == '\0') ||
270 	    (strlen(mailname) > MAX_UNAME) || (getpwnam(mailname) == NULL)) {
271 		pass_entry = getpwuid(real_uid);
272 		if (pass_entry != NULL)
273 			mailname = pass_entry->pw_name;
274 	}
275 
276 	/*
277 	 * Get the shell to run the job under.  First check $SHELL, falling
278 	 * back to the user's shell in the password database or, failing
279 	 * that, /bin/sh.
280 	 */
281 	if ((shell = getenv("SHELL")) == NULL || *shell == '\0') {
282 		pass_entry = getpwuid(real_uid);
283 		if (pass_entry != NULL && *pass_entry->pw_shell != '\0')
284 			shell = pass_entry->pw_shell;
285 		else
286 			shell = _PATH_BSHELL;
287 	}
288 
289 	(void)fprintf(fp, "#!/bin/sh\n# atrun uid=%lu gid=%lu\n# mail %*s %d\n",
290 	    (unsigned long)real_uid, (unsigned long)real_gid,
291 	    MAX_UNAME, mailname, send_mail);
292 
293 	/* Write out the umask at the time of invocation */
294 	(void)fprintf(fp, "umask %o\n", cmask);
295 
296 	/*
297 	 * Write out the environment. Anything that may look like a special
298 	 * character to the shell is quoted, except for \n, which is done
299 	 * with a pair of "'s.  Don't export the no_export list (such as
300 	 * TERM or DISPLAY) because we don't want these.
301 	 */
302 	for (atenv = environ; *atenv != NULL; atenv++) {
303 		int export = 1;
304 		char *eqp;
305 
306 		eqp = strchr(*atenv, '=');
307 		if (eqp == NULL)
308 			eqp = *atenv;
309 		else {
310 			int i;
311 
312 			for (i = 0;i < sizeof(no_export) /
313 			    sizeof(no_export[0]); i++) {
314 				export = export
315 				    && (strncmp(*atenv, no_export[i],
316 					(size_t) (eqp - *atenv)) != 0);
317 			}
318 			eqp++;
319 		}
320 
321 		if (export) {
322 			(void)fputs("export ", fp);
323 			(void)fwrite(*atenv, sizeof(char), eqp - *atenv, fp);
324 			for (ap = eqp; *ap != '\0'; ap++) {
325 				if (*ap == '\n')
326 					(void)fprintf(fp, "\"\n\"");
327 				else {
328 					if (!isalnum((unsigned char)*ap)) {
329 						switch (*ap) {
330 						case '%': case '/': case '{':
331 						case '[': case ']': case '=':
332 						case '}': case '@': case '+':
333 						case '#': case ',': case '.':
334 						case ':': case '-': case '_':
335 							break;
336 						default:
337 							(void)fputc('\\', fp);
338 							break;
339 						}
340 					}
341 					(void)fputc(*ap, fp);
342 				}
343 			}
344 			(void)fputc('\n', fp);
345 		}
346 	}
347 	/*
348 	 * Cd to the directory at the time and write out all the
349 	 * commands the user supplies from stdin.
350 	 */
351 	(void)fputs("cd ", fp);
352 	for (ap = cwd; *ap != '\0'; ap++) {
353 		if (*ap == '\n')
354 			fprintf(fp, "\"\n\"");
355 		else {
356 			if (*ap != '/' && !isalnum((unsigned char)*ap))
357 				(void)fputc('\\', fp);
358 
359 			(void)fputc(*ap, fp);
360 		}
361 	}
362 	/*
363 	 * Test cd's exit status: die if the original directory has been
364 	 * removed, become unreadable or whatever.
365 	 */
366 	(void)fprintf(fp, " || {\n\t echo 'Execution directory inaccessible'"
367 	    " >&2\n\t exit 1\n}\n");
368 
369 	if ((ch = getchar()) == EOF)
370 		panic("Input error");
371 
372 	/* We want the job to run under the user's shell. */
373 	fprintf(fp, "%s << '_END_OF_AT_JOB'\n", shell);
374 
375 	do {
376 		(void)fputc(ch, fp);
377 	} while ((ch = getchar()) != EOF);
378 
379 	(void)fprintf(fp, "\n_END_OF_AT_JOB\n");
380 	if (ferror(fp))
381 		panic("Output error");
382 
383 	if (ferror(stdin))
384 		panic("Input error");
385 
386 	(void)fclose(fp);
387 
388 	/*
389 	 * Set the x bit so that we're ready to start executing
390 	 */
391 	if (fchmod(fd2, S_IRUSR | S_IWUSR | S_IXUSR) < 0)
392 		perr("Cannot give away file");
393 
394 	(void)close(fd2);
395 
396 	/* Poke cron so it knows to reload the at spool. */
397 	PRIV_START;
398 	poke_daemon(AT_DIR, RELOAD_AT);
399 	PRIV_END;
400 
401 	runtime = *localtime(&runtimer);
402 	strftime(timestr, TIMESIZE, "%a %b %e %T %Y", &runtime);
403 	(void)fprintf(stderr, "commands will be executed using %s\n", shell);
404 	(void)fprintf(stderr, "job %s at %s\n", &atfile[sizeof(AT_DIR)],
405 	    timestr);
406 }
407 
408 /* Sort by creation time. */
409 static int
410 byctime(const void *v1, const void *v2)
411 {
412 	const struct atjob *j1 = *(const struct atjob **)v1;
413 	const struct atjob *j2 = *(const struct atjob **)v2;
414 
415 	return (j1->ctime - j2->ctime);
416 }
417 
418 /* Sort by job number (and thus execution time). */
419 static int
420 byjobno(const void *v1, const void *v2)
421 {
422 	const struct atjob *j1 = *(struct atjob **)v1;
423 	const struct atjob *j2 = *(struct atjob **)v2;
424 
425 	if (j1->runtimer == j2->runtimer)
426 		return (j1->queue - j2->queue);
427 	return (j1->runtimer - j2->runtimer);
428 }
429 
430 static void
431 print_job(struct atjob *job, int n, int shortformat)
432 {
433 	struct passwd *pw;
434 	struct tm runtime;
435 	char timestr[TIMESIZE];
436 	static char *ranks[] = {
437 		"th", "st", "nd", "rd", "th", "th", "th", "th", "th", "th"
438 	};
439 
440 	runtime = *localtime(&job->runtimer);
441 	if (shortformat) {
442 		strftime(timestr, TIMESIZE, "%a %b %e %T %Y", &runtime);
443 		(void)printf("%lld.%c\t%s\n", (long long)job->runtimer,
444 		    job->queue, timestr);
445 	} else {
446 		pw = getpwuid(job->uid);
447 		/* Rank hack shamelessly stolen from lpq */
448 		if (n / 10 == 1)
449 			printf("%3d%-5s", n,"th");
450 		else
451 			printf("%3d%-5s", n, ranks[n % 10]);
452 		strftime(timestr, TIMESIZE, "%b %e, %Y %R", &runtime);
453 		(void)printf("%-21.18s%-11.8s%10lld.%c   %c%s\n",
454 		    timestr, pw ? pw->pw_name : "???",
455 		    (long long)job->runtimer, job->queue, job->queue,
456 		    (S_IXUSR & job->mode) ? "" : " (done)");
457 	}
458 }
459 
460 /*
461  * List all of a user's jobs in the queue, by looping through
462  * AT_DIR, or all jobs if we are root.  If argc is > 0, argv
463  * contains the list of users whose jobs shall be displayed. By
464  * default, the list is sorted by execution date and queue.  If
465  * csort is non-zero jobs will be sorted by creation/submission date.
466  */
467 static void
468 list_jobs(int argc, char **argv, int count_only, int csort)
469 {
470 	struct passwd *pw;
471 	struct dirent *dirent;
472 	struct atjob **atjobs, **newatjobs, *job;
473 	struct stat stbuf;
474 	time_t runtimer;
475 	uid_t *uids;
476 	char queue, *ep;
477 	DIR *spool;
478 	int i, shortformat;
479 	size_t numjobs, maxjobs;
480 
481 	if (argc) {
482 		if ((uids = calloc(sizeof(uid_t), argc)) == NULL)
483 			panic("Insufficient virtual memory");
484 
485 		for (i = 0; i < argc; i++) {
486 			if ((pw = getpwnam(argv[i])) == NULL)
487 				panic2(argv[i], ": invalid user name");
488 			if (pw->pw_uid != real_uid && real_uid != 0)
489 				panic("Only the superuser may display other users' jobs");
490 			uids[i] = pw->pw_uid;
491 		}
492 	} else
493 		uids = NULL;
494 
495 	shortformat = strcmp(ProgramName, "at") == 0;
496 
497 	PRIV_START;
498 
499 	if (chdir(AT_DIR) != 0)
500 		perr2("Cannot change to ", AT_DIR);
501 
502 	if ((spool = opendir(".")) == NULL)
503 		perr2("Cannot open ", AT_DIR);
504 
505 	PRIV_END;
506 
507 	if (fstat(dirfd(spool), &stbuf) != 0)
508 		perr2("Cannot stat ", AT_DIR);
509 
510 	/*
511 	 * The directory's link count should give us a good idea
512 	 * of how many files are in it.  Fudge things a little just
513 	 * in case someone adds a job or two.
514 	 */
515 	numjobs = 0;
516 	maxjobs = stbuf.st_nlink + 4;
517 	atjobs = (struct atjob **)calloc(maxjobs, sizeof(struct atjob *));
518 	if (atjobs == NULL)
519 		panic("Insufficient virtual memory");
520 
521 	/* Loop over every file in the directory. */
522 	while ((dirent = readdir(spool)) != NULL) {
523 		PRIV_START;
524 
525 		if (stat(dirent->d_name, &stbuf) != 0)
526 			perr2("Cannot stat in ", AT_DIR);
527 
528 		PRIV_END;
529 
530 		/*
531 		 * See it's a regular file and has its x bit turned on and
532 		 * is the user's
533 		 */
534 		if (!S_ISREG(stbuf.st_mode)
535 		    || ((stbuf.st_uid != real_uid) && !(real_uid == 0))
536 		    || !(S_IXUSR & stbuf.st_mode || vflag))
537 			continue;
538 
539 		if (strtot(dirent->d_name, &ep, &runtimer) == -1)
540 			continue;
541 		if (*ep != '.' || !isalpha((unsigned char)*(ep + 1)) ||
542 		    *(ep + 2) != '\0')
543 			continue;
544 		queue = *(ep + 1);
545 
546 		if (atqueue && (queue != atqueue))
547 			continue;
548 
549 		/* Check against specified user(s). */
550 		if (argc) {
551 			for (i = 0; i < argc; i++) {
552 				if (uids[0] == stbuf.st_uid)
553 					break;
554 			}
555 			if (i == argc)
556 				continue;	/* user doesn't match */
557 		}
558 
559 		if (count_only) {
560 			numjobs++;
561 			continue;
562 		}
563 
564 		job = (struct atjob *)malloc(sizeof(struct atjob));
565 		if (job == NULL)
566 			panic("Insufficient virtual memory");
567 		job->runtimer = runtimer;
568 		job->ctime = stbuf.st_ctime;
569 		job->uid = stbuf.st_uid;
570 		job->mode = stbuf.st_mode;
571 		job->queue = queue;
572 		if (numjobs == maxjobs) {
573 			size_t newjobs = maxjobs * 2;
574 			newatjobs = reallocarray(atjobs, newjobs, sizeof(job));
575 			if (newatjobs == NULL)
576 				panic("Insufficient virtual memory");
577 			atjobs = newatjobs;
578 			maxjobs = newjobs;
579 		}
580 		atjobs[numjobs++] = job;
581 	}
582 	free(uids);
583 	closedir(spool);
584 
585 	if (count_only || numjobs == 0) {
586 		if (numjobs == 0 && !shortformat)
587 			fprintf(stderr, "no files in queue.\n");
588 		else if (count_only)
589 			printf("%zu\n", numjobs);
590 		free(atjobs);
591 		return;
592 	}
593 
594 	/* Sort by job run time or by job creation time. */
595 	qsort(atjobs, numjobs, sizeof(struct atjob *),
596 	    csort ? byctime : byjobno);
597 
598 	if (!shortformat)
599 		(void)puts(" Rank     Execution Date     Owner          "
600 		    "Job       Queue");
601 
602 	for (i = 0; i < numjobs; i++) {
603 		print_job(atjobs[i], i + 1, shortformat);
604 		free(atjobs[i]);
605 	}
606 	free(atjobs);
607 }
608 
609 static int
610 rmok(long long job)
611 {
612 	int ch, junk;
613 
614 	printf("%lld: remove it? ", job);
615 	ch = getchar();
616 	while ((junk = getchar()) != EOF && junk != '\n')
617 		;
618 	return (ch == 'y' || ch == 'Y');
619 }
620 
621 /*
622  * Loop through all jobs in AT_DIR and display or delete ones
623  * that match argv (may be job or username), or all if argc == 0.
624  * Only the superuser may display/delete other people's jobs.
625  */
626 static int
627 process_jobs(int argc, char **argv, int what)
628 {
629 	struct stat stbuf;
630 	struct dirent *dirent;
631 	struct passwd *pw;
632 	time_t runtimer;
633 	uid_t *uids;
634 	char **jobs, *ep;
635 	long l;
636 	FILE *fp;
637 	DIR *spool;
638 	int job_matches, jobs_len, uids_len;
639 	int error, i, ch, changed;
640 
641 	PRIV_START;
642 
643 	if (chdir(AT_DIR) != 0)
644 		perr2("Cannot change to ", AT_DIR);
645 
646 	if ((spool = opendir(".")) == NULL)
647 		perr2("Cannot open ", AT_DIR);
648 
649 	PRIV_END;
650 
651 	/* Convert argv into a list of jobs and uids. */
652 	jobs = NULL;
653 	uids = NULL;
654 	jobs_len = uids_len = 0;
655 	if (argc > 0) {
656 		if ((jobs = calloc(sizeof(char *), argc)) == NULL ||
657 		    (uids = calloc(sizeof(uid_t), argc)) == NULL)
658 			panic("Insufficient virtual memory");
659 
660 		for (i = 0; i < argc; i++) {
661 			l = strtol(argv[i], &ep, 10);
662 			if (*ep == '.' && isalpha((unsigned char)*(ep + 1)) &&
663 			    *(ep + 2) == '\0' && l > 0 && l < INT_MAX)
664 				jobs[jobs_len++] = argv[i];
665 			else if ((pw = getpwnam(argv[i])) != NULL) {
666 				if (real_uid != pw->pw_uid && real_uid != 0) {
667 					fprintf(stderr, "%s: Only the superuser"
668 					    " may %s other users' jobs\n",
669 					    ProgramName, what == ATRM
670 					    ? "remove" : "view");
671 					exit(EXIT_FAILURE);
672 				}
673 				uids[uids_len++] = pw->pw_uid;
674 			} else
675 				panic2(argv[i], ": invalid user name");
676 		}
677 	}
678 
679 	/* Loop over every file in the directory */
680 	changed = 0;
681 	while ((dirent = readdir(spool)) != NULL) {
682 
683 		PRIV_START;
684 		if (stat(dirent->d_name, &stbuf) != 0)
685 			perr2("Cannot stat in ", AT_DIR);
686 		PRIV_END;
687 
688 		if (stbuf.st_uid != real_uid && real_uid != 0)
689 			continue;
690 
691 		if (strtot(dirent->d_name, &ep, &runtimer) == -1)
692 			continue;
693 		if (*ep != '.' || !isalpha((unsigned char)*(ep + 1)) ||
694 		    *(ep + 2) != '\0')
695 			continue;
696 
697 		/* Check runtimer against argv; argc==0 means do all. */
698 		job_matches = (argc == 0) ? 1 : 0;
699 		if (!job_matches) {
700 			for (i = 0; i < jobs_len; i++) {
701 				if (jobs[i] != NULL &&
702 				    strcmp(dirent->d_name, jobs[i]) == 0) {
703 					jobs[i] = NULL;
704 					job_matches = 1;
705 					break;
706 				}
707 			}
708 		}
709 		if (!job_matches) {
710 			for (i = 0; i < uids_len; i++) {
711 				if (uids[i] == stbuf.st_uid) {
712 					job_matches = 1;
713 					break;
714 				}
715 			}
716 		}
717 
718 		if (job_matches) {
719 			switch (what) {
720 			case ATRM:
721 				PRIV_START;
722 
723 				if (!interactive ||
724 				    (interactive && rmok(runtimer))) {
725 					if (unlink(dirent->d_name) == 0)
726 						changed = 1;
727 					else
728 						perr(dirent->d_name);
729 					if (!force && !interactive)
730 						fprintf(stderr,
731 						    "%s removed\n",
732 						    dirent->d_name);
733 				}
734 
735 				PRIV_END;
736 
737 				break;
738 
739 			case CAT:
740 				PRIV_START;
741 
742 				fp = fopen(dirent->d_name, "r");
743 
744 				PRIV_END;
745 
746 				if (!fp)
747 					perr("Cannot open file");
748 
749 				while ((ch = getc(fp)) != EOF)
750 					putchar(ch);
751 
752 				fclose(fp);
753 				break;
754 
755 			default:
756 				panic("Internal error");
757 				break;
758 			}
759 		}
760 	}
761 	closedir(spool);
762 
763 	for (error = 0, i = 0; i < jobs_len; i++) {
764 		if (jobs[i] != NULL) {
765 			if (!force)
766 				fprintf(stderr, "%s: %s: no such job\n",
767 				    ProgramName, jobs[i]);
768 			error++;
769 		}
770 	}
771 	free(jobs);
772 	free(uids);
773 
774 	/* If we modied the spool, poke cron so it knows to reload. */
775 	if (changed) {
776 		PRIV_START;
777 		if (chdir(CRONDIR) != 0)
778 			perror(CRONDIR);
779 		else
780 			poke_daemon(AT_DIR, RELOAD_AT);
781 		PRIV_END;
782 	}
783 
784 	return (error);
785 }
786 
787 #define	ATOI2(s)	((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
788 
789 /*
790  * Adapted from date(1)
791  */
792 static time_t
793 ttime(char *arg)
794 {
795 	time_t now, then;
796 	struct tm *lt;
797 	int yearset;
798 	char *dot, *p;
799 
800 	if (time(&now) == (time_t)-1 || (lt = localtime(&now)) == NULL)
801 		panic("Cannot get current time");
802 
803 	/* Valid date format is [[CC]YY]MMDDhhmm[.SS] */
804 	for (p = arg, dot = NULL; *p != '\0'; p++) {
805 		if (*p == '.' && dot == NULL)
806 			dot = p;
807 		else if (!isdigit((unsigned char)*p))
808 			goto terr;
809 	}
810 	if (dot == NULL)
811 		lt->tm_sec = 0;
812 	else {
813 		*dot++ = '\0';
814 		if (strlen(dot) != 2)
815 			goto terr;
816 		lt->tm_sec = ATOI2(dot);
817 		if (lt->tm_sec > 61)	/* could be leap second */
818 			goto terr;
819 	}
820 
821 	yearset = 0;
822 	switch(strlen(arg)) {
823 	case 12:			/* CCYYMMDDhhmm */
824 		lt->tm_year = ATOI2(arg) * 100;
825 		lt->tm_year -= 1900;	/* Convert to Unix time */
826 		yearset = 1;
827 		/* FALLTHROUGH */
828 	case 10:			/* YYMMDDhhmm */
829 		if (yearset) {
830 			yearset = ATOI2(arg);
831 			lt->tm_year += yearset;
832 		} else {
833 			yearset = ATOI2(arg);
834 			/* POSIX logic: [00,68]=>20xx, [69,99]=>19xx */
835 			lt->tm_year = yearset;
836 			if (yearset < 69)
837 				lt->tm_year += 100;
838 		}
839 		/* FALLTHROUGH */
840 	case 8:				/* MMDDhhmm */
841 		lt->tm_mon = ATOI2(arg);
842 		if (lt->tm_mon > 12 || lt->tm_mon == 0)
843 			goto terr;
844 		--lt->tm_mon;		/* Convert from 01-12 to 00-11 */
845 		lt->tm_mday = ATOI2(arg);
846 		if (lt->tm_mday > 31 || lt->tm_mday == 0)
847 			goto terr;
848 		lt->tm_hour = ATOI2(arg);
849 		if (lt->tm_hour > 23)
850 			goto terr;
851 		lt->tm_min = ATOI2(arg);
852 		if (lt->tm_min > 59)
853 			goto terr;
854 		break;
855 	default:
856 		goto terr;
857 	}
858 
859 	lt->tm_isdst = -1;		/* mktime will deduce DST. */
860 	then = mktime(lt);
861 	if (then == (time_t)-1) {
862     terr:
863 		panic("illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
864 	}
865 	if (then < now)
866 		panic("cannot schedule jobs in the past");
867 	return (then);
868 }
869 
870 static int
871 check_permission(void)
872 {
873 	int ok;
874 	uid_t uid = geteuid();
875 	struct passwd *pw;
876 
877 	if ((pw = getpwuid(uid)) == NULL) {
878 		perror("Cannot access password database");
879 		exit(EXIT_FAILURE);
880 	}
881 
882 	PRIV_START;
883 
884 	ok = allowed(pw->pw_name, AT_ALLOW, AT_DENY);
885 
886 	PRIV_END;
887 
888 	return (ok);
889 }
890 
891 static __dead void
892 usage(void)
893 {
894 	/* Print usage and exit.  */
895 	switch (program) {
896 	case AT:
897 	case CAT:
898 		(void)fprintf(stderr,
899 		    "usage: at [-bm] [-f file] [-l [user ...]] [-q queue] "
900 		    "-t time_arg | timespec\n"
901 		    "       at -c | -r job ...\n");
902 		break;
903 	case ATQ:
904 		(void)fprintf(stderr,
905 		    "usage: atq [-cnv] [-q queue] [name ...]\n");
906 		break;
907 	case ATRM:
908 		(void)fprintf(stderr,
909 		    "usage: atrm [-afi] [[job] [name] ...]\n");
910 		break;
911 	case BATCH:
912 		(void)fprintf(stderr,
913 		    "usage: batch [-m] [-f file] [-q queue] [timespec]\n");
914 		break;
915 	}
916 	exit(EXIT_FAILURE);
917 }
918 
919 int
920 main(int argc, char **argv)
921 {
922 	time_t timer = -1;
923 	char *atinput = NULL;			/* where to get input from */
924 	char queue = DEFAULT_AT_QUEUE;
925 	char queue_set = 0;
926 	char *options = "q:f:t:bcdlmrv";	/* default options for at */
927 	char cwd[PATH_MAX];
928 	int ch;
929 	int aflag = 0;
930 	int cflag = 0;
931 	int nflag = 0;
932 
933 	if (argc < 1)
934 		usage();
935 
936 	if ((ProgramName = strrchr(argv[0], '/')) != NULL)
937 		ProgramName++;
938 	else
939 		ProgramName = argv[0];
940 
941 	RELINQUISH_PRIVS;
942 
943 	/* find out what this program is supposed to do */
944 	if (strcmp(ProgramName, "atq") == 0) {
945 		program = ATQ;
946 		options = "cnvq:";
947 	} else if (strcmp(ProgramName, "atrm") == 0) {
948 		program = ATRM;
949 		options = "afi";
950 	} else if (strcmp(ProgramName, "batch") == 0) {
951 		program = BATCH;
952 		options = "f:q:mv";
953 	}
954 
955 	/* process whatever options we can process */
956 	while ((ch = getopt(argc, argv, options)) != -1) {
957 		switch (ch) {
958 		case 'a':
959 			aflag = 1;
960 			break;
961 
962 		case 'i':
963 			interactive = 1;
964 			force = 0;
965 			break;
966 
967 		case 'v':	/* show completed but unremoved jobs */
968 			/*
969 			 * This option is only useful when we are invoked
970 			 * as atq but we accept (and ignore) this flag in
971 			 * the other programs for backwards compatibility.
972 			 */
973 			vflag = 1;
974 			break;
975 
976 		case 'm':	/* send mail when job is complete */
977 			send_mail = 1;
978 			break;
979 
980 		case 'f':
981 			if (program == ATRM) {
982 				force = 1;
983 				interactive = 0;
984 			} else
985 				atinput = optarg;
986 			break;
987 
988 		case 'q':	/* specify queue */
989 			if (strlen(optarg) > 1)
990 				usage();
991 
992 			atqueue = queue = *optarg;
993 			if (!(islower((unsigned char)queue) ||
994 			    isupper((unsigned char)queue)))
995 				usage();
996 
997 			queue_set = 1;
998 			break;
999 
1000 		case 'd':		/* for backwards compatibility */
1001 		case 'r':
1002 			program = ATRM;
1003 			options = "";
1004 			break;
1005 
1006 		case 't':
1007 			timer = ttime(optarg);
1008 			break;
1009 
1010 		case 'l':
1011 			program = ATQ;
1012 			options = "cnvq:";
1013 			break;
1014 
1015 		case 'b':
1016 			program = BATCH;
1017 			options = "f:q:mv";
1018 			break;
1019 
1020 		case 'c':
1021 			if (program == ATQ) {
1022 				cflag = 1;
1023 			} else {
1024 				program = CAT;
1025 				options = "";
1026 			}
1027 			break;
1028 
1029 		case 'n':
1030 			nflag = 1;
1031 			break;
1032 
1033 		default:
1034 			usage();
1035 			break;
1036 		}
1037 	}
1038 	argc -= optind;
1039 	argv += optind;
1040 
1041 	switch (program) {
1042 	case AT:
1043 	case BATCH:
1044 		if (atinput != NULL) {
1045 			if (freopen(atinput, "r", stdin) == NULL)
1046 				perr("Cannot open input file");
1047 		}
1048 		break;
1049 	default:
1050 		;
1051 	}
1052 
1053 	if (getcwd(cwd, sizeof(cwd)) == NULL)
1054 		perr("Cannot get current working directory");
1055 
1056 	set_cron_cwd();
1057 
1058 	if (!check_permission())
1059 		panic("You do not have permission to use at.");
1060 
1061 	/* select our program */
1062 	switch (program) {
1063 	case ATQ:
1064 		list_jobs(argc, argv, nflag, cflag);
1065 		break;
1066 
1067 	case ATRM:
1068 	case CAT:
1069 		if ((aflag && argc) || (!aflag && !argc))
1070 			usage();
1071 		exit(process_jobs(argc, argv, program));
1072 		break;
1073 
1074 	case AT:
1075 		/* Time may have been specified via the -t flag. */
1076 		if (timer == -1) {
1077 			if (argc == 0)
1078 				usage();
1079 			else if ((timer = parsetime(argc, argv)) == -1)
1080 				exit(EXIT_FAILURE);
1081 		}
1082 		writefile(cwd, timer, queue);
1083 		break;
1084 
1085 	case BATCH:
1086 		if (queue_set)
1087 			queue = toupper((unsigned char)queue);
1088 		else
1089 			queue = DEFAULT_BATCH_QUEUE;
1090 
1091 		if (argc == 0)
1092 			timer = time(NULL);
1093 		else if ((timer = parsetime(argc, argv)) == -1)
1094 			exit(EXIT_FAILURE);
1095 
1096 		writefile(cwd, timer, queue);
1097 		break;
1098 
1099 	default:
1100 		panic("Internal error");
1101 		break;
1102 	}
1103 	exit(EXIT_SUCCESS);
1104 }
1105