xref: /freebsd/usr.sbin/cron/lib/entry.c (revision d6b92ffa)
1 /* Copyright 1988,1990,1993,1994 by Paul Vixie
2  * All rights reserved
3  *
4  * Distribute freely, except: don't remove my name from the source or
5  * documentation (don't take credit for my work), mark your changes (don't
6  * get me blamed for your possible bugs), don't alter or remove this
7  * notice.  May be sold if buildable source is provided to buyer.  No
8  * warrantee of any kind, express or implied, is included with this
9  * software; use at your own risk, responsibility for damages (if any) to
10  * anyone resulting from the use of this software rests entirely with the
11  * user.
12  *
13  * Send bug reports, bug fixes, enhancements, requests, flames, etc., and
14  * I'll try to keep a version up to date.  I can be reached as follows:
15  * Paul Vixie          <paul@vix.com>          uunet!decwrl!vixie!paul
16  */
17 
18 #if !defined(lint) && !defined(LINT)
19 static const char rcsid[] =
20   "$FreeBSD$";
21 #endif
22 
23 /* vix 26jan87 [RCS'd; rest of log is in RCS file]
24  * vix 01jan87 [added line-level error recovery]
25  * vix 31dec86 [added /step to the from-to range, per bob@acornrc]
26  * vix 30dec86 [written]
27  */
28 
29 
30 #include "cron.h"
31 #include <grp.h>
32 #ifdef LOGIN_CAP
33 #include <login_cap.h>
34 #endif
35 
36 typedef	enum ecode {
37 	e_none, e_minute, e_hour, e_dom, e_month, e_dow,
38 	e_cmd, e_timespec, e_username, e_group, e_mem
39 #ifdef LOGIN_CAP
40 	, e_class
41 #endif
42 } ecode_e;
43 
44 static char	get_list(bitstr_t *, int, int, char *[], int, FILE *),
45 		get_range(bitstr_t *, int, int, char *[], int, FILE *),
46 		get_number(int *, int, char *[], int, FILE *);
47 static int	set_element(bitstr_t *, int, int, int);
48 
49 static char *ecodes[] =
50 	{
51 		"no error",
52 		"bad minute",
53 		"bad hour",
54 		"bad day-of-month",
55 		"bad month",
56 		"bad day-of-week",
57 		"bad command",
58 		"bad time specifier",
59 		"bad username",
60 		"bad group name",
61 		"out of memory",
62 #ifdef LOGIN_CAP
63 		"bad class name",
64 #endif
65 	};
66 
67 
68 void
69 free_entry(e)
70 	entry	*e;
71 {
72 #ifdef LOGIN_CAP
73 	if (e->class != NULL)
74 		free(e->class);
75 #endif
76 	if (e->cmd != NULL)
77 		free(e->cmd);
78 	if (e->envp != NULL)
79 		env_free(e->envp);
80 	free(e);
81 }
82 
83 
84 /* return NULL if eof or syntax error occurs;
85  * otherwise return a pointer to a new entry.
86  */
87 entry *
88 load_entry(file, error_func, pw, envp)
89 	FILE		*file;
90 	void		(*error_func)(char *);
91 	struct passwd	*pw;
92 	char		**envp;
93 {
94 	/* this function reads one crontab entry -- the next -- from a file.
95 	 * it skips any leading blank lines, ignores comments, and returns
96 	 * EOF if for any reason the entry can't be read and parsed.
97 	 *
98 	 * the entry is also parsed here.
99 	 *
100 	 * syntax:
101 	 *   user crontab:
102 	 *	minutes hours doms months dows cmd\n
103 	 *   system crontab (/etc/crontab):
104 	 *	minutes hours doms months dows USERNAME cmd\n
105 	 */
106 
107 	ecode_e	ecode = e_none;
108 	entry	*e;
109 	int	ch;
110 	char	cmd[MAX_COMMAND];
111 	char	envstr[MAX_ENVSTR];
112 	char	**prev_env;
113 
114 	Debug(DPARS, ("load_entry()...about to eat comments\n"))
115 
116 	skip_comments(file);
117 
118 	ch = get_char(file);
119 	if (ch == EOF)
120 		return NULL;
121 
122 	/* ch is now the first useful character of a useful line.
123 	 * it may be an @special or it may be the first character
124 	 * of a list of minutes.
125 	 */
126 
127 	e = (entry *) calloc(sizeof(entry), sizeof(char));
128 
129 	if (e == NULL) {
130 		warn("load_entry: calloc failed");
131 		return NULL;
132 	}
133 
134 	if (ch == '@') {
135 		/* all of these should be flagged and load-limited; i.e.,
136 		 * instead of @hourly meaning "0 * * * *" it should mean
137 		 * "close to the front of every hour but not 'til the
138 		 * system load is low".  Problems are: how do you know
139 		 * what "low" means? (save me from /etc/cron.conf!) and:
140 		 * how to guarantee low variance (how low is low?), which
141 		 * means how to we run roughly every hour -- seems like
142 		 * we need to keep a history or let the first hour set
143 		 * the schedule, which means we aren't load-limited
144 		 * anymore.  too much for my overloaded brain. (vix, jan90)
145 		 * HINT
146 		 */
147 		Debug(DPARS, ("load_entry()...about to test shortcuts\n"))
148 		ch = get_string(cmd, MAX_COMMAND, file, " \t\n");
149 		if (!strcmp("reboot", cmd)) {
150 			Debug(DPARS, ("load_entry()...reboot shortcut\n"))
151 			e->flags |= WHEN_REBOOT;
152 		} else if (!strcmp("yearly", cmd) || !strcmp("annually", cmd)){
153 			Debug(DPARS, ("load_entry()...yearly shortcut\n"))
154 			bit_set(e->second, 0);
155 			bit_set(e->minute, 0);
156 			bit_set(e->hour, 0);
157 			bit_set(e->dom, 0);
158 			bit_set(e->month, 0);
159 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
160 			e->flags |= DOW_STAR;
161 		} else if (!strcmp("monthly", cmd)) {
162 			Debug(DPARS, ("load_entry()...monthly shortcut\n"))
163 			bit_set(e->second, 0);
164 			bit_set(e->minute, 0);
165 			bit_set(e->hour, 0);
166 			bit_set(e->dom, 0);
167 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
168 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
169 			e->flags |= DOW_STAR;
170 		} else if (!strcmp("weekly", cmd)) {
171 			Debug(DPARS, ("load_entry()...weekly shortcut\n"))
172 			bit_set(e->second, 0);
173 			bit_set(e->minute, 0);
174 			bit_set(e->hour, 0);
175 			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
176 			e->flags |= DOM_STAR;
177 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
178 			bit_set(e->dow, 0);
179 		} else if (!strcmp("daily", cmd) || !strcmp("midnight", cmd)) {
180 			Debug(DPARS, ("load_entry()...daily shortcut\n"))
181 			bit_set(e->second, 0);
182 			bit_set(e->minute, 0);
183 			bit_set(e->hour, 0);
184 			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
185 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
186 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
187 		} else if (!strcmp("hourly", cmd)) {
188 			Debug(DPARS, ("load_entry()...hourly shortcut\n"))
189 			bit_set(e->second, 0);
190 			bit_set(e->minute, 0);
191 			bit_nset(e->hour, 0, (LAST_HOUR-FIRST_HOUR+1));
192 			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
193 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
194 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
195 		} else if (!strcmp("every_minute", cmd)) {
196 			Debug(DPARS, ("load_entry()...every_minute shortcut\n"))
197 			bit_set(e->second, 0);
198 			bit_nset(e->minute, 0, (LAST_MINUTE-FIRST_MINUTE+1));
199 			bit_nset(e->hour, 0, (LAST_HOUR-FIRST_HOUR+1));
200 			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
201 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
202 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
203 		} else if (!strcmp("every_second", cmd)) {
204 			Debug(DPARS, ("load_entry()...every_second shortcut\n"))
205 			e->flags |= SEC_RES;
206 			bit_nset(e->second, 0, (LAST_SECOND-FIRST_SECOND+1));
207 			bit_nset(e->minute, 0, (LAST_MINUTE-FIRST_MINUTE+1));
208 			bit_nset(e->hour, 0, (LAST_HOUR-FIRST_HOUR+1));
209 			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
210 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
211 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
212 		} else {
213 			ecode = e_timespec;
214 			goto eof;
215 		}
216 		/* Advance past whitespace between shortcut and
217 		 * username/command.
218 		 */
219 		Skip_Blanks(ch, file);
220 		if (ch == EOF) {
221 			ecode = e_cmd;
222 			goto eof;
223 		}
224 	} else {
225 		Debug(DPARS, ("load_entry()...about to parse numerics\n"))
226 		bit_set(e->second, 0);
227 
228 		ch = get_list(e->minute, FIRST_MINUTE, LAST_MINUTE,
229 			      PPC_NULL, ch, file);
230 		if (ch == EOF) {
231 			ecode = e_minute;
232 			goto eof;
233 		}
234 
235 		/* hours
236 		 */
237 
238 		ch = get_list(e->hour, FIRST_HOUR, LAST_HOUR,
239 			      PPC_NULL, ch, file);
240 		if (ch == EOF) {
241 			ecode = e_hour;
242 			goto eof;
243 		}
244 
245 		/* DOM (days of month)
246 		 */
247 
248 		if (ch == '*')
249 			e->flags |= DOM_STAR;
250 		ch = get_list(e->dom, FIRST_DOM, LAST_DOM,
251 			      PPC_NULL, ch, file);
252 		if (ch == EOF) {
253 			ecode = e_dom;
254 			goto eof;
255 		}
256 
257 		/* month
258 		 */
259 
260 		ch = get_list(e->month, FIRST_MONTH, LAST_MONTH,
261 			      MonthNames, ch, file);
262 		if (ch == EOF) {
263 			ecode = e_month;
264 			goto eof;
265 		}
266 
267 		/* DOW (days of week)
268 		 */
269 
270 		if (ch == '*')
271 			e->flags |= DOW_STAR;
272 		ch = get_list(e->dow, FIRST_DOW, LAST_DOW,
273 			      DowNames, ch, file);
274 		if (ch == EOF) {
275 			ecode = e_dow;
276 			goto eof;
277 		}
278 	}
279 
280 	/* make sundays equivalent */
281 	if (bit_test(e->dow, 0) || bit_test(e->dow, 7)) {
282 		bit_set(e->dow, 0);
283 		bit_set(e->dow, 7);
284 	}
285 
286 	/* ch is the first character of a command, or a username */
287 	unget_char(ch, file);
288 
289 	if (!pw) {
290 		char		*username = cmd;	/* temp buffer */
291 		char            *s;
292 		struct group    *grp;
293 #ifdef LOGIN_CAP
294 		login_cap_t *lc;
295 #endif
296 
297 		Debug(DPARS, ("load_entry()...about to parse username\n"))
298 		ch = get_string(username, MAX_COMMAND, file, " \t");
299 
300 		Debug(DPARS, ("load_entry()...got %s\n",username))
301 		if (ch == EOF) {
302 			ecode = e_cmd;
303 			goto eof;
304 		}
305 
306 #ifdef LOGIN_CAP
307 		if ((s = strrchr(username, '/')) != NULL) {
308 			*s = '\0';
309 			e->class = strdup(s + 1);
310 			if (e->class == NULL)
311 				warn("strdup(\"%s\")", s + 1);
312 		} else {
313 			e->class = strdup(RESOURCE_RC);
314 			if (e->class == NULL)
315 				warn("strdup(\"%s\")", RESOURCE_RC);
316 		}
317 		if (e->class == NULL) {
318 			ecode = e_mem;
319 			goto eof;
320 		}
321 		if ((lc = login_getclass(e->class)) == NULL) {
322 			ecode = e_class;
323 			goto eof;
324 		}
325 		login_close(lc);
326 #endif
327 		grp = NULL;
328 		if ((s = strrchr(username, ':')) != NULL) {
329 			*s = '\0';
330 			if ((grp = getgrnam(s + 1)) == NULL) {
331 				ecode = e_group;
332 				goto eof;
333 			}
334 		}
335 
336 		pw = getpwnam(username);
337 		if (pw == NULL) {
338 			ecode = e_username;
339 			goto eof;
340 		}
341 		if (grp != NULL)
342 			pw->pw_gid = grp->gr_gid;
343 		Debug(DPARS, ("load_entry()...uid %d, gid %d\n",pw->pw_uid,pw->pw_gid))
344 #ifdef LOGIN_CAP
345 		Debug(DPARS, ("load_entry()...class %s\n",e->class))
346 #endif
347 	}
348 
349 #ifndef PAM	/* PAM takes care of account expiration by itself */
350 	if (pw->pw_expire && time(NULL) >= pw->pw_expire) {
351 		ecode = e_username;
352 		goto eof;
353 	}
354 #endif /* !PAM */
355 
356 	e->uid = pw->pw_uid;
357 	e->gid = pw->pw_gid;
358 
359 	/* copy and fix up environment.  some variables are just defaults and
360 	 * others are overrides.
361 	 */
362 	e->envp = env_copy(envp);
363 	if (e->envp == NULL) {
364 		warn("env_copy");
365 		ecode = e_mem;
366 		goto eof;
367 	}
368 	if (!env_get("SHELL", e->envp)) {
369 		prev_env = e->envp;
370 		sprintf(envstr, "SHELL=%s", _PATH_BSHELL);
371 		e->envp = env_set(e->envp, envstr);
372 		if (e->envp == NULL) {
373 			warn("env_set(%s)", envstr);
374 			env_free(prev_env);
375 			ecode = e_mem;
376 			goto eof;
377 		}
378 	}
379 	if (!env_get("HOME", e->envp)) {
380 		prev_env = e->envp;
381 		sprintf(envstr, "HOME=%s", pw->pw_dir);
382 		e->envp = env_set(e->envp, envstr);
383 		if (e->envp == NULL) {
384 			warn("env_set(%s)", envstr);
385 			env_free(prev_env);
386 			ecode = e_mem;
387 			goto eof;
388 		}
389 	}
390 	if (!env_get("PATH", e->envp)) {
391 		prev_env = e->envp;
392 		sprintf(envstr, "PATH=%s", _PATH_DEFPATH);
393 		e->envp = env_set(e->envp, envstr);
394 		if (e->envp == NULL) {
395 			warn("env_set(%s)", envstr);
396 			env_free(prev_env);
397 			ecode = e_mem;
398 			goto eof;
399 		}
400 	}
401 	prev_env = e->envp;
402 	sprintf(envstr, "%s=%s", "LOGNAME", pw->pw_name);
403 	e->envp = env_set(e->envp, envstr);
404 	if (e->envp == NULL) {
405 		warn("env_set(%s)", envstr);
406 		env_free(prev_env);
407 		ecode = e_mem;
408 		goto eof;
409 	}
410 #if defined(BSD)
411 	prev_env = e->envp;
412 	sprintf(envstr, "%s=%s", "USER", pw->pw_name);
413 	e->envp = env_set(e->envp, envstr);
414 	if (e->envp == NULL) {
415 		warn("env_set(%s)", envstr);
416 		env_free(prev_env);
417 		ecode = e_mem;
418 		goto eof;
419 	}
420 #endif
421 
422 	Debug(DPARS, ("load_entry()...about to parse command\n"))
423 
424 	/* Everything up to the next \n or EOF is part of the command...
425 	 * too bad we don't know in advance how long it will be, since we
426 	 * need to malloc a string for it... so, we limit it to MAX_COMMAND.
427 	 * XXX - should use realloc().
428 	 */
429 	ch = get_string(cmd, MAX_COMMAND, file, "\n");
430 
431 	/* a file without a \n before the EOF is rude, so we'll complain...
432 	 */
433 	if (ch == EOF) {
434 		ecode = e_cmd;
435 		goto eof;
436 	}
437 
438 	/* got the command in the 'cmd' string; save it in *e.
439 	 */
440 	e->cmd = strdup(cmd);
441 	if (e->cmd == NULL) {
442 		warn("strdup(\"%s\")", cmd);
443 		ecode = e_mem;
444 		goto eof;
445 	}
446 	Debug(DPARS, ("load_entry()...returning successfully\n"))
447 
448 	/* success, fini, return pointer to the entry we just created...
449 	 */
450 	return e;
451 
452  eof:
453 	free_entry(e);
454 	if (ecode != e_none && error_func)
455 		(*error_func)(ecodes[(int)ecode]);
456 	while (ch != EOF && ch != '\n')
457 		ch = get_char(file);
458 	return NULL;
459 }
460 
461 
462 static char
463 get_list(bits, low, high, names, ch, file)
464 	bitstr_t	*bits;		/* one bit per flag, default=FALSE */
465 	int		low, high;	/* bounds, impl. offset for bitstr */
466 	char		*names[];	/* NULL or *[] of names for these elements */
467 	int		ch;		/* current character being processed */
468 	FILE		*file;		/* file being read */
469 {
470 	register int	done;
471 
472 	/* we know that we point to a non-blank character here;
473 	 * must do a Skip_Blanks before we exit, so that the
474 	 * next call (or the code that picks up the cmd) can
475 	 * assume the same thing.
476 	 */
477 
478 	Debug(DPARS|DEXT, ("get_list()...entered\n"))
479 
480 	/* list = range {"," range}
481 	 */
482 
483 	/* clear the bit string, since the default is 'off'.
484 	 */
485 	bit_nclear(bits, 0, (high-low+1));
486 
487 	/* process all ranges
488 	 */
489 	done = FALSE;
490 	while (!done) {
491 		ch = get_range(bits, low, high, names, ch, file);
492 		if (ch == ',')
493 			ch = get_char(file);
494 		else
495 			done = TRUE;
496 	}
497 
498 	/* exiting.  skip to some blanks, then skip over the blanks.
499 	 */
500 	Skip_Nonblanks(ch, file)
501 	Skip_Blanks(ch, file)
502 
503 	Debug(DPARS|DEXT, ("get_list()...exiting w/ %02x\n", ch))
504 
505 	return ch;
506 }
507 
508 
509 static char
510 get_range(bits, low, high, names, ch, file)
511 	bitstr_t	*bits;		/* one bit per flag, default=FALSE */
512 	int		low, high;	/* bounds, impl. offset for bitstr */
513 	char		*names[];	/* NULL or names of elements */
514 	int		ch;		/* current character being processed */
515 	FILE		*file;		/* file being read */
516 {
517 	/* range = number | number "-" number [ "/" number ]
518 	 */
519 
520 	register int	i;
521 	auto int	num1, num2, num3;
522 
523 	Debug(DPARS|DEXT, ("get_range()...entering, exit won't show\n"))
524 
525 	if (ch == '*') {
526 		/* '*' means "first-last" but can still be modified by /step
527 		 */
528 		num1 = low;
529 		num2 = high;
530 		ch = get_char(file);
531 		if (ch == EOF)
532 			return EOF;
533 	} else {
534 		if (EOF == (ch = get_number(&num1, low, names, ch, file)))
535 			return EOF;
536 
537 		if (ch == '/')
538 			num2 = high;
539 		else if (ch != '-') {
540 			/* not a range, it's a single number.
541 			 */
542 			if (EOF == set_element(bits, low, high, num1))
543 				return EOF;
544 			return ch;
545 		} else {
546 			/* eat the dash
547 			 */
548 			ch = get_char(file);
549 			if (ch == EOF)
550 				return EOF;
551 
552 			/* get the number following the dash
553 			 */
554 			ch = get_number(&num2, low, names, ch, file);
555 			if (ch == EOF)
556 				return EOF;
557 		}
558 	}
559 
560 	/* check for step size
561 	 */
562 	if (ch == '/') {
563 		/* eat the slash
564 		 */
565 		ch = get_char(file);
566 		if (ch == EOF)
567 			return EOF;
568 
569 		/* get the step size -- note: we don't pass the
570 		 * names here, because the number is not an
571 		 * element id, it's a step size.  'low' is
572 		 * sent as a 0 since there is no offset either.
573 		 */
574 		ch = get_number(&num3, 0, PPC_NULL, ch, file);
575 		if (ch == EOF || num3 == 0)
576 			return EOF;
577 	} else {
578 		/* no step.  default==1.
579 		 */
580 		num3 = 1;
581 	}
582 
583 	/* range. set all elements from num1 to num2, stepping
584 	 * by num3.  (the step is a downward-compatible extension
585 	 * proposed conceptually by bob@acornrc, syntactically
586 	 * designed then implmented by paul vixie).
587 	 */
588 	for (i = num1;  i <= num2;  i += num3)
589 		if (EOF == set_element(bits, low, high, i))
590 			return EOF;
591 
592 	return ch;
593 }
594 
595 
596 static char
597 get_number(numptr, low, names, ch, file)
598 	int	*numptr;	/* where does the result go? */
599 	int	low;		/* offset applied to result if symbolic enum used */
600 	char	*names[];	/* symbolic names, if any, for enums */
601 	int	ch;		/* current character */
602 	FILE	*file;		/* source */
603 {
604 	char	temp[MAX_TEMPSTR], *pc;
605 	int	len, i, all_digits;
606 
607 	/* collect alphanumerics into our fixed-size temp array
608 	 */
609 	pc = temp;
610 	len = 0;
611 	all_digits = TRUE;
612 	while (isalnum(ch)) {
613 		if (++len >= MAX_TEMPSTR)
614 			return EOF;
615 
616 		*pc++ = ch;
617 
618 		if (!isdigit(ch))
619 			all_digits = FALSE;
620 
621 		ch = get_char(file);
622 	}
623 	*pc = '\0';
624 	if (len == 0)
625 	    return (EOF);
626 
627 	/* try to find the name in the name list
628 	 */
629 	if (names) {
630 		for (i = 0;  names[i] != NULL;  i++) {
631 			Debug(DPARS|DEXT,
632 				("get_num, compare(%s,%s)\n", names[i], temp))
633 			if (!strcasecmp(names[i], temp)) {
634 				*numptr = i+low;
635 				return ch;
636 			}
637 		}
638 	}
639 
640 	/* no name list specified, or there is one and our string isn't
641 	 * in it.  either way: if it's all digits, use its magnitude.
642 	 * otherwise, it's an error.
643 	 */
644 	if (all_digits) {
645 		*numptr = atoi(temp);
646 		return ch;
647 	}
648 
649 	return EOF;
650 }
651 
652 
653 static int
654 set_element(bits, low, high, number)
655 	bitstr_t	*bits; 		/* one bit per flag, default=FALSE */
656 	int		low;
657 	int		high;
658 	int		number;
659 {
660 	Debug(DPARS|DEXT, ("set_element(?,%d,%d,%d)\n", low, high, number))
661 
662 	if (number < low || number > high)
663 		return EOF;
664 
665 	bit_set(bits, (number-low));
666 	return OK;
667 }
668