xref: /freebsd/usr.sbin/cron/lib/entry.c (revision a1a4f1a0d87b594d3f17a97dc0127eec1417e6f6)
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
39 #ifdef LOGIN_CAP
40 	, e_class
41 #endif
42 } ecode_e;
43 
44 static char	get_list __P((bitstr_t *, int, int, char *[], int, FILE *)),
45 		get_range __P((bitstr_t *, int, int, char *[], int, FILE *)),
46 		get_number __P((int *, int, char *[], int, FILE *));
47 static int	set_element __P((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 #ifdef LOGIN_CAP
62 		"bad class name",
63 #endif
64 	};
65 
66 
67 void
68 free_entry(e)
69 	entry	*e;
70 {
71 #ifdef LOGIN_CAP
72 	if (e->class != NULL)
73 		free(e->class);
74 #endif
75 	free(e->cmd);
76 	env_free(e->envp);
77 	free(e);
78 }
79 
80 
81 /* return NULL if eof or syntax error occurs;
82  * otherwise return a pointer to a new entry.
83  */
84 entry *
85 load_entry(file, error_func, pw, envp)
86 	FILE		*file;
87 	void		(*error_func)();
88 	struct passwd	*pw;
89 	char		**envp;
90 {
91 	/* this function reads one crontab entry -- the next -- from a file.
92 	 * it skips any leading blank lines, ignores comments, and returns
93 	 * EOF if for any reason the entry can't be read and parsed.
94 	 *
95 	 * the entry is also parsed here.
96 	 *
97 	 * syntax:
98 	 *   user crontab:
99 	 *	minutes hours doms months dows cmd\n
100 	 *   system crontab (/etc/crontab):
101 	 *	minutes hours doms months dows USERNAME cmd\n
102 	 */
103 
104 	ecode_e	ecode = e_none;
105 	entry	*e;
106 	int	ch;
107 	char	cmd[MAX_COMMAND];
108 	char	envstr[MAX_ENVSTR];
109 
110 	Debug(DPARS, ("load_entry()...about to eat comments\n"))
111 
112 	skip_comments(file);
113 
114 	ch = get_char(file);
115 	if (ch == EOF)
116 		return NULL;
117 
118 	/* ch is now the first useful character of a useful line.
119 	 * it may be an @special or it may be the first character
120 	 * of a list of minutes.
121 	 */
122 
123 	e = (entry *) calloc(sizeof(entry), sizeof(char));
124 
125 	if (ch == '@') {
126 		/* all of these should be flagged and load-limited; i.e.,
127 		 * instead of @hourly meaning "0 * * * *" it should mean
128 		 * "close to the front of every hour but not 'til the
129 		 * system load is low".  Problems are: how do you know
130 		 * what "low" means? (save me from /etc/cron.conf!) and:
131 		 * how to guarantee low variance (how low is low?), which
132 		 * means how to we run roughly every hour -- seems like
133 		 * we need to keep a history or let the first hour set
134 		 * the schedule, which means we aren't load-limited
135 		 * anymore.  too much for my overloaded brain. (vix, jan90)
136 		 * HINT
137 		 */
138 		ch = get_string(cmd, MAX_COMMAND, file, " \t\n");
139 		if (!strcmp("reboot", cmd)) {
140 			e->flags |= WHEN_REBOOT;
141 		} else if (!strcmp("yearly", cmd) || !strcmp("annually", cmd)){
142 			bit_set(e->minute, 0);
143 			bit_set(e->hour, 0);
144 			bit_set(e->dom, 0);
145 			bit_set(e->month, 0);
146 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
147 		} else if (!strcmp("monthly", cmd)) {
148 			bit_set(e->minute, 0);
149 			bit_set(e->hour, 0);
150 			bit_set(e->dom, 0);
151 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
152 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
153 		} else if (!strcmp("weekly", cmd)) {
154 			bit_set(e->minute, 0);
155 			bit_set(e->hour, 0);
156 			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
157 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
158 			bit_set(e->dow, 0);
159 		} else if (!strcmp("daily", cmd) || !strcmp("midnight", cmd)) {
160 			bit_set(e->minute, 0);
161 			bit_set(e->hour, 0);
162 			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
163 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
164 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
165 		} else if (!strcmp("hourly", cmd)) {
166 			bit_set(e->minute, 0);
167 			bit_set(e->hour, (LAST_HOUR-FIRST_HOUR+1));
168 			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
169 			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
170 			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
171 		} else {
172 			ecode = e_timespec;
173 			goto eof;
174 		}
175 	} else {
176 		Debug(DPARS, ("load_entry()...about to parse numerics\n"))
177 
178 		ch = get_list(e->minute, FIRST_MINUTE, LAST_MINUTE,
179 			      PPC_NULL, ch, file);
180 		if (ch == EOF) {
181 			ecode = e_minute;
182 			goto eof;
183 		}
184 
185 		/* hours
186 		 */
187 
188 		ch = get_list(e->hour, FIRST_HOUR, LAST_HOUR,
189 			      PPC_NULL, ch, file);
190 		if (ch == EOF) {
191 			ecode = e_hour;
192 			goto eof;
193 		}
194 
195 		/* DOM (days of month)
196 		 */
197 
198 		if (ch == '*')
199 			e->flags |= DOM_STAR;
200 		ch = get_list(e->dom, FIRST_DOM, LAST_DOM,
201 			      PPC_NULL, ch, file);
202 		if (ch == EOF) {
203 			ecode = e_dom;
204 			goto eof;
205 		}
206 
207 		/* month
208 		 */
209 
210 		ch = get_list(e->month, FIRST_MONTH, LAST_MONTH,
211 			      MonthNames, ch, file);
212 		if (ch == EOF) {
213 			ecode = e_month;
214 			goto eof;
215 		}
216 
217 		/* DOW (days of week)
218 		 */
219 
220 		if (ch == '*')
221 			e->flags |= DOW_STAR;
222 		ch = get_list(e->dow, FIRST_DOW, LAST_DOW,
223 			      DowNames, ch, file);
224 		if (ch == EOF) {
225 			ecode = e_dow;
226 			goto eof;
227 		}
228 	}
229 
230 	/* make sundays equivilent */
231 	if (bit_test(e->dow, 0) || bit_test(e->dow, 7)) {
232 		bit_set(e->dow, 0);
233 		bit_set(e->dow, 7);
234 	}
235 
236 	/* ch is the first character of a command, or a username */
237 	unget_char(ch, file);
238 
239 	if (!pw) {
240 		char		*username = cmd;	/* temp buffer */
241 		char            *s, *group;
242 		struct group    *grp;
243 
244 		Debug(DPARS, ("load_entry()...about to parse username\n"))
245 		ch = get_string(username, MAX_COMMAND, file, " \t");
246 
247 		Debug(DPARS, ("load_entry()...got %s\n",username))
248 		if (ch == EOF) {
249 			ecode = e_cmd;
250 			goto eof;
251 		}
252 
253 #ifdef LOGIN_CAP
254 		if ((s = strrchr(username, '/')) != NULL) {
255 			*s = '\0';
256 			e->class = strdup(s + 1);
257 		} else
258 			e->class = strdup(RESOURCE_RC);
259 		if (login_getclass(e->class) == NULL) {
260 			ecode = e_class;
261 			goto eof;
262 		}
263 #endif
264 		grp = NULL;
265 		if ((s = strrchr(username, ':')) != NULL) {
266 			*s = '\0';
267 			if ((grp = getgrnam(s + 1)) == NULL) {
268 				ecode = e_group;
269 				goto eof;
270 			}
271 		}
272 
273 		pw = getpwnam(username);
274 		if (pw == NULL) {
275 			ecode = e_username;
276 			goto eof;
277 		}
278 		if (grp != NULL)
279 			pw->pw_gid = grp->gr_gid;
280 		Debug(DPARS, ("load_entry()...uid %d, gid %d\n",pw->pw_uid,pw->pw_gid))
281 #ifdef LOGIN_CAP
282 		Debug(DPARS, ("load_entry()...class %s\n",e->class))
283 #endif
284 	}
285 
286 	if (pw->pw_expire && time(NULL) >= pw->pw_expire) {
287 		ecode = e_username;
288 		goto eof;
289 	}
290 
291 	e->uid = pw->pw_uid;
292 	e->gid = pw->pw_gid;
293 
294 	/* copy and fix up environment.  some variables are just defaults and
295 	 * others are overrides.
296 	 */
297 	e->envp = env_copy(envp);
298 	if (!env_get("SHELL", e->envp)) {
299 		sprintf(envstr, "SHELL=%s", _PATH_BSHELL);
300 		e->envp = env_set(e->envp, envstr);
301 	}
302 	sprintf(envstr, "HOME=%s", pw->pw_dir);
303 	e->envp = env_set(e->envp, envstr);
304 	if (!env_get("PATH", e->envp)) {
305 		sprintf(envstr, "PATH=%s", _PATH_DEFPATH);
306 		e->envp = env_set(e->envp, envstr);
307 	}
308 	sprintf(envstr, "%s=%s", "LOGNAME", pw->pw_name);
309 	e->envp = env_set(e->envp, envstr);
310 #if defined(BSD)
311 	sprintf(envstr, "%s=%s", "USER", pw->pw_name);
312 	e->envp = env_set(e->envp, envstr);
313 #endif
314 
315 	Debug(DPARS, ("load_entry()...about to parse command\n"))
316 
317 	/* Everything up to the next \n or EOF is part of the command...
318 	 * too bad we don't know in advance how long it will be, since we
319 	 * need to malloc a string for it... so, we limit it to MAX_COMMAND.
320 	 * XXX - should use realloc().
321 	 */
322 	ch = get_string(cmd, MAX_COMMAND, file, "\n");
323 
324 	/* a file without a \n before the EOF is rude, so we'll complain...
325 	 */
326 	if (ch == EOF) {
327 		ecode = e_cmd;
328 		goto eof;
329 	}
330 
331 	/* got the command in the 'cmd' string; save it in *e.
332 	 */
333 	e->cmd = strdup(cmd);
334 
335 	Debug(DPARS, ("load_entry()...returning successfully\n"))
336 
337 	/* success, fini, return pointer to the entry we just created...
338 	 */
339 	return e;
340 
341  eof:
342 	free(e);
343 	if (ecode != e_none && error_func)
344 		(*error_func)(ecodes[(int)ecode]);
345 	while (ch != EOF && ch != '\n')
346 		ch = get_char(file);
347 	return NULL;
348 }
349 
350 
351 static char
352 get_list(bits, low, high, names, ch, file)
353 	bitstr_t	*bits;		/* one bit per flag, default=FALSE */
354 	int		low, high;	/* bounds, impl. offset for bitstr */
355 	char		*names[];	/* NULL or *[] of names for these elements */
356 	int		ch;		/* current character being processed */
357 	FILE		*file;		/* file being read */
358 {
359 	register int	done;
360 
361 	/* we know that we point to a non-blank character here;
362 	 * must do a Skip_Blanks before we exit, so that the
363 	 * next call (or the code that picks up the cmd) can
364 	 * assume the same thing.
365 	 */
366 
367 	Debug(DPARS|DEXT, ("get_list()...entered\n"))
368 
369 	/* list = range {"," range}
370 	 */
371 
372 	/* clear the bit string, since the default is 'off'.
373 	 */
374 	bit_nclear(bits, 0, (high-low+1));
375 
376 	/* process all ranges
377 	 */
378 	done = FALSE;
379 	while (!done) {
380 		ch = get_range(bits, low, high, names, ch, file);
381 		if (ch == ',')
382 			ch = get_char(file);
383 		else
384 			done = TRUE;
385 	}
386 
387 	/* exiting.  skip to some blanks, then skip over the blanks.
388 	 */
389 	Skip_Nonblanks(ch, file)
390 	Skip_Blanks(ch, file)
391 
392 	Debug(DPARS|DEXT, ("get_list()...exiting w/ %02x\n", ch))
393 
394 	return ch;
395 }
396 
397 
398 static char
399 get_range(bits, low, high, names, ch, file)
400 	bitstr_t	*bits;		/* one bit per flag, default=FALSE */
401 	int		low, high;	/* bounds, impl. offset for bitstr */
402 	char		*names[];	/* NULL or names of elements */
403 	int		ch;		/* current character being processed */
404 	FILE		*file;		/* file being read */
405 {
406 	/* range = number | number "-" number [ "/" number ]
407 	 */
408 
409 	register int	i;
410 	auto int	num1, num2, num3;
411 
412 	Debug(DPARS|DEXT, ("get_range()...entering, exit won't show\n"))
413 
414 	if (ch == '*') {
415 		/* '*' means "first-last" but can still be modified by /step
416 		 */
417 		num1 = low;
418 		num2 = high;
419 		ch = get_char(file);
420 		if (ch == EOF)
421 			return EOF;
422 	} else {
423 		if (EOF == (ch = get_number(&num1, low, names, ch, file)))
424 			return EOF;
425 
426 		if (ch != '-') {
427 			/* not a range, it's a single number.
428 			 */
429 			if (EOF == set_element(bits, low, high, num1))
430 				return EOF;
431 			return ch;
432 		} else {
433 			/* eat the dash
434 			 */
435 			ch = get_char(file);
436 			if (ch == EOF)
437 				return EOF;
438 
439 			/* get the number following the dash
440 			 */
441 			ch = get_number(&num2, low, names, ch, file);
442 			if (ch == EOF)
443 				return EOF;
444 		}
445 	}
446 
447 	/* check for step size
448 	 */
449 	if (ch == '/') {
450 		/* eat the slash
451 		 */
452 		ch = get_char(file);
453 		if (ch == EOF)
454 			return EOF;
455 
456 		/* get the step size -- note: we don't pass the
457 		 * names here, because the number is not an
458 		 * element id, it's a step size.  'low' is
459 		 * sent as a 0 since there is no offset either.
460 		 */
461 		ch = get_number(&num3, 0, PPC_NULL, ch, file);
462 		if (ch == EOF)
463 			return EOF;
464 	} else {
465 		/* no step.  default==1.
466 		 */
467 		num3 = 1;
468 	}
469 
470 	/* range. set all elements from num1 to num2, stepping
471 	 * by num3.  (the step is a downward-compatible extension
472 	 * proposed conceptually by bob@acornrc, syntactically
473 	 * designed then implmented by paul vixie).
474 	 */
475 	for (i = num1;  i <= num2;  i += num3)
476 		if (EOF == set_element(bits, low, high, i))
477 			return EOF;
478 
479 	return ch;
480 }
481 
482 
483 static char
484 get_number(numptr, low, names, ch, file)
485 	int	*numptr;	/* where does the result go? */
486 	int	low;		/* offset applied to result if symbolic enum used */
487 	char	*names[];	/* symbolic names, if any, for enums */
488 	int	ch;		/* current character */
489 	FILE	*file;		/* source */
490 {
491 	char	temp[MAX_TEMPSTR], *pc;
492 	int	len, i, all_digits;
493 
494 	/* collect alphanumerics into our fixed-size temp array
495 	 */
496 	pc = temp;
497 	len = 0;
498 	all_digits = TRUE;
499 	while (isalnum(ch)) {
500 		if (++len >= MAX_TEMPSTR)
501 			return EOF;
502 
503 		*pc++ = ch;
504 
505 		if (!isdigit(ch))
506 			all_digits = FALSE;
507 
508 		ch = get_char(file);
509 	}
510 	*pc = '\0';
511 
512 	/* try to find the name in the name list
513 	 */
514 	if (names) {
515 		for (i = 0;  names[i] != NULL;  i++) {
516 			Debug(DPARS|DEXT,
517 				("get_num, compare(%s,%s)\n", names[i], temp))
518 			if (!strcasecmp(names[i], temp)) {
519 				*numptr = i+low;
520 				return ch;
521 			}
522 		}
523 	}
524 
525 	/* no name list specified, or there is one and our string isn't
526 	 * in it.  either way: if it's all digits, use its magnitude.
527 	 * otherwise, it's an error.
528 	 */
529 	if (all_digits) {
530 		*numptr = atoi(temp);
531 		return ch;
532 	}
533 
534 	return EOF;
535 }
536 
537 
538 static int
539 set_element(bits, low, high, number)
540 	bitstr_t	*bits; 		/* one bit per flag, default=FALSE */
541 	int		low;
542 	int		high;
543 	int		number;
544 {
545 	Debug(DPARS|DEXT, ("set_element(?,%d,%d,%d)\n", low, high, number))
546 
547 	if (number < low || number > high)
548 		return EOF;
549 
550 	bit_set(bits, (number-low));
551 	return OK;
552 }
553