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)
19static 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
36typedef	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
44static 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 *);
47static int	set_element(bitstr_t *, int, int, int);
48
49static 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
68void
69free_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 */
87entry *
88load_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->minute, 0);
155			bit_set(e->hour, 0);
156			bit_set(e->dom, 0);
157			bit_set(e->month, 0);
158			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
159			e->flags |= DOW_STAR;
160		} else if (!strcmp("monthly", cmd)) {
161			Debug(DPARS, ("load_entry()...monthly shortcut\n"))
162			bit_set(e->minute, 0);
163			bit_set(e->hour, 0);
164			bit_set(e->dom, 0);
165			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
166			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
167			e->flags |= DOW_STAR;
168		} else if (!strcmp("weekly", cmd)) {
169			Debug(DPARS, ("load_entry()...weekly shortcut\n"))
170			bit_set(e->minute, 0);
171			bit_set(e->hour, 0);
172			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
173			e->flags |= DOM_STAR;
174			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
175			bit_set(e->dow, 0);
176		} else if (!strcmp("daily", cmd) || !strcmp("midnight", cmd)) {
177			Debug(DPARS, ("load_entry()...daily shortcut\n"))
178			bit_set(e->minute, 0);
179			bit_set(e->hour, 0);
180			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
181			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
182			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
183		} else if (!strcmp("hourly", cmd)) {
184			Debug(DPARS, ("load_entry()...hourly shortcut\n"))
185			bit_set(e->minute, 0);
186			bit_nset(e->hour, 0, (LAST_HOUR-FIRST_HOUR+1));
187			bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
188			bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
189			bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
190		} else {
191			ecode = e_timespec;
192			goto eof;
193		}
194		/* Advance past whitespace between shortcut and
195		 * username/command.
196		 */
197		Skip_Blanks(ch, file);
198		if (ch == EOF) {
199			ecode = e_cmd;
200			goto eof;
201		}
202	} else {
203		Debug(DPARS, ("load_entry()...about to parse numerics\n"))
204
205		ch = get_list(e->minute, FIRST_MINUTE, LAST_MINUTE,
206			      PPC_NULL, ch, file);
207		if (ch == EOF) {
208			ecode = e_minute;
209			goto eof;
210		}
211
212		/* hours
213		 */
214
215		ch = get_list(e->hour, FIRST_HOUR, LAST_HOUR,
216			      PPC_NULL, ch, file);
217		if (ch == EOF) {
218			ecode = e_hour;
219			goto eof;
220		}
221
222		/* DOM (days of month)
223		 */
224
225		if (ch == '*')
226			e->flags |= DOM_STAR;
227		ch = get_list(e->dom, FIRST_DOM, LAST_DOM,
228			      PPC_NULL, ch, file);
229		if (ch == EOF) {
230			ecode = e_dom;
231			goto eof;
232		}
233
234		/* month
235		 */
236
237		ch = get_list(e->month, FIRST_MONTH, LAST_MONTH,
238			      MonthNames, ch, file);
239		if (ch == EOF) {
240			ecode = e_month;
241			goto eof;
242		}
243
244		/* DOW (days of week)
245		 */
246
247		if (ch == '*')
248			e->flags |= DOW_STAR;
249		ch = get_list(e->dow, FIRST_DOW, LAST_DOW,
250			      DowNames, ch, file);
251		if (ch == EOF) {
252			ecode = e_dow;
253			goto eof;
254		}
255	}
256
257	/* make sundays equivilent */
258	if (bit_test(e->dow, 0) || bit_test(e->dow, 7)) {
259		bit_set(e->dow, 0);
260		bit_set(e->dow, 7);
261	}
262
263	/* ch is the first character of a command, or a username */
264	unget_char(ch, file);
265
266	if (!pw) {
267		char		*username = cmd;	/* temp buffer */
268		char            *s;
269		struct group    *grp;
270#ifdef LOGIN_CAP
271		login_cap_t *lc;
272#endif
273
274		Debug(DPARS, ("load_entry()...about to parse username\n"))
275		ch = get_string(username, MAX_COMMAND, file, " \t");
276
277		Debug(DPARS, ("load_entry()...got %s\n",username))
278		if (ch == EOF) {
279			ecode = e_cmd;
280			goto eof;
281		}
282
283#ifdef LOGIN_CAP
284		if ((s = strrchr(username, '/')) != NULL) {
285			*s = '\0';
286			e->class = strdup(s + 1);
287			if (e->class == NULL)
288				warn("strdup(\"%s\")", s + 1);
289		} else {
290			e->class = strdup(RESOURCE_RC);
291			if (e->class == NULL)
292				warn("strdup(\"%s\")", RESOURCE_RC);
293		}
294		if (e->class == NULL) {
295			ecode = e_mem;
296			goto eof;
297		}
298		if ((lc = login_getclass(e->class)) == NULL) {
299			ecode = e_class;
300			goto eof;
301		}
302		login_close(lc);
303#endif
304		grp = NULL;
305		if ((s = strrchr(username, ':')) != NULL) {
306			*s = '\0';
307			if ((grp = getgrnam(s + 1)) == NULL) {
308				ecode = e_group;
309				goto eof;
310			}
311		}
312
313		pw = getpwnam(username);
314		if (pw == NULL) {
315			ecode = e_username;
316			goto eof;
317		}
318		if (grp != NULL)
319			pw->pw_gid = grp->gr_gid;
320		Debug(DPARS, ("load_entry()...uid %d, gid %d\n",pw->pw_uid,pw->pw_gid))
321#ifdef LOGIN_CAP
322		Debug(DPARS, ("load_entry()...class %s\n",e->class))
323#endif
324	}
325
326#ifndef PAM	/* PAM takes care of account expiration by itself */
327	if (pw->pw_expire && time(NULL) >= pw->pw_expire) {
328		ecode = e_username;
329		goto eof;
330	}
331#endif /* !PAM */
332
333	e->uid = pw->pw_uid;
334	e->gid = pw->pw_gid;
335
336	/* copy and fix up environment.  some variables are just defaults and
337	 * others are overrides.
338	 */
339	e->envp = env_copy(envp);
340	if (e->envp == NULL) {
341		warn("env_copy");
342		ecode = e_mem;
343		goto eof;
344	}
345	if (!env_get("SHELL", e->envp)) {
346		prev_env = e->envp;
347		sprintf(envstr, "SHELL=%s", _PATH_BSHELL);
348		e->envp = env_set(e->envp, envstr);
349		if (e->envp == NULL) {
350			warn("env_set(%s)", envstr);
351			env_free(prev_env);
352			ecode = e_mem;
353			goto eof;
354		}
355	}
356	if (!env_get("HOME", e->envp)) {
357		prev_env = e->envp;
358		sprintf(envstr, "HOME=%s", pw->pw_dir);
359		e->envp = env_set(e->envp, envstr);
360		if (e->envp == NULL) {
361			warn("env_set(%s)", envstr);
362			env_free(prev_env);
363			ecode = e_mem;
364			goto eof;
365		}
366	}
367	if (!env_get("PATH", e->envp)) {
368		prev_env = e->envp;
369		sprintf(envstr, "PATH=%s", _PATH_DEFPATH);
370		e->envp = env_set(e->envp, envstr);
371		if (e->envp == NULL) {
372			warn("env_set(%s)", envstr);
373			env_free(prev_env);
374			ecode = e_mem;
375			goto eof;
376		}
377	}
378	prev_env = e->envp;
379	sprintf(envstr, "%s=%s", "LOGNAME", pw->pw_name);
380	e->envp = env_set(e->envp, envstr);
381	if (e->envp == NULL) {
382		warn("env_set(%s)", envstr);
383		env_free(prev_env);
384		ecode = e_mem;
385		goto eof;
386	}
387#if defined(BSD)
388	prev_env = e->envp;
389	sprintf(envstr, "%s=%s", "USER", pw->pw_name);
390	e->envp = env_set(e->envp, envstr);
391	if (e->envp == NULL) {
392		warn("env_set(%s)", envstr);
393		env_free(prev_env);
394		ecode = e_mem;
395		goto eof;
396	}
397#endif
398
399	Debug(DPARS, ("load_entry()...about to parse command\n"))
400
401	/* Everything up to the next \n or EOF is part of the command...
402	 * too bad we don't know in advance how long it will be, since we
403	 * need to malloc a string for it... so, we limit it to MAX_COMMAND.
404	 * XXX - should use realloc().
405	 */
406	ch = get_string(cmd, MAX_COMMAND, file, "\n");
407
408	/* a file without a \n before the EOF is rude, so we'll complain...
409	 */
410	if (ch == EOF) {
411		ecode = e_cmd;
412		goto eof;
413	}
414
415	/* got the command in the 'cmd' string; save it in *e.
416	 */
417	e->cmd = strdup(cmd);
418	if (e->cmd == NULL) {
419		warn("strdup(\"%s\")", cmd);
420		ecode = e_mem;
421		goto eof;
422	}
423	Debug(DPARS, ("load_entry()...returning successfully\n"))
424
425	/* success, fini, return pointer to the entry we just created...
426	 */
427	return e;
428
429 eof:
430	free_entry(e);
431	if (ecode != e_none && error_func)
432		(*error_func)(ecodes[(int)ecode]);
433	while (ch != EOF && ch != '\n')
434		ch = get_char(file);
435	return NULL;
436}
437
438
439static char
440get_list(bits, low, high, names, ch, file)
441	bitstr_t	*bits;		/* one bit per flag, default=FALSE */
442	int		low, high;	/* bounds, impl. offset for bitstr */
443	char		*names[];	/* NULL or *[] of names for these elements */
444	int		ch;		/* current character being processed */
445	FILE		*file;		/* file being read */
446{
447	register int	done;
448
449	/* we know that we point to a non-blank character here;
450	 * must do a Skip_Blanks before we exit, so that the
451	 * next call (or the code that picks up the cmd) can
452	 * assume the same thing.
453	 */
454
455	Debug(DPARS|DEXT, ("get_list()...entered\n"))
456
457	/* list = range {"," range}
458	 */
459
460	/* clear the bit string, since the default is 'off'.
461	 */
462	bit_nclear(bits, 0, (high-low+1));
463
464	/* process all ranges
465	 */
466	done = FALSE;
467	while (!done) {
468		ch = get_range(bits, low, high, names, ch, file);
469		if (ch == ',')
470			ch = get_char(file);
471		else
472			done = TRUE;
473	}
474
475	/* exiting.  skip to some blanks, then skip over the blanks.
476	 */
477	Skip_Nonblanks(ch, file)
478	Skip_Blanks(ch, file)
479
480	Debug(DPARS|DEXT, ("get_list()...exiting w/ %02x\n", ch))
481
482	return ch;
483}
484
485
486static char
487get_range(bits, low, high, names, ch, file)
488	bitstr_t	*bits;		/* one bit per flag, default=FALSE */
489	int		low, high;	/* bounds, impl. offset for bitstr */
490	char		*names[];	/* NULL or names of elements */
491	int		ch;		/* current character being processed */
492	FILE		*file;		/* file being read */
493{
494	/* range = number | number "-" number [ "/" number ]
495	 */
496
497	register int	i;
498	auto int	num1, num2, num3;
499
500	Debug(DPARS|DEXT, ("get_range()...entering, exit won't show\n"))
501
502	if (ch == '*') {
503		/* '*' means "first-last" but can still be modified by /step
504		 */
505		num1 = low;
506		num2 = high;
507		ch = get_char(file);
508		if (ch == EOF)
509			return EOF;
510	} else {
511		if (EOF == (ch = get_number(&num1, low, names, ch, file)))
512			return EOF;
513
514		if (ch == '/')
515			num2 = high;
516		else if (ch != '-') {
517			/* not a range, it's a single number.
518			 */
519			if (EOF == set_element(bits, low, high, num1))
520				return EOF;
521			return ch;
522		} else {
523			/* eat the dash
524			 */
525			ch = get_char(file);
526			if (ch == EOF)
527				return EOF;
528
529			/* get the number following the dash
530			 */
531			ch = get_number(&num2, low, names, ch, file);
532			if (ch == EOF)
533				return EOF;
534		}
535	}
536
537	/* check for step size
538	 */
539	if (ch == '/') {
540		/* eat the slash
541		 */
542		ch = get_char(file);
543		if (ch == EOF)
544			return EOF;
545
546		/* get the step size -- note: we don't pass the
547		 * names here, because the number is not an
548		 * element id, it's a step size.  'low' is
549		 * sent as a 0 since there is no offset either.
550		 */
551		ch = get_number(&num3, 0, PPC_NULL, ch, file);
552		if (ch == EOF || num3 == 0)
553			return EOF;
554	} else {
555		/* no step.  default==1.
556		 */
557		num3 = 1;
558	}
559
560	/* range. set all elements from num1 to num2, stepping
561	 * by num3.  (the step is a downward-compatible extension
562	 * proposed conceptually by bob@acornrc, syntactically
563	 * designed then implmented by paul vixie).
564	 */
565	for (i = num1;  i <= num2;  i += num3)
566		if (EOF == set_element(bits, low, high, i))
567			return EOF;
568
569	return ch;
570}
571
572
573static char
574get_number(numptr, low, names, ch, file)
575	int	*numptr;	/* where does the result go? */
576	int	low;		/* offset applied to result if symbolic enum used */
577	char	*names[];	/* symbolic names, if any, for enums */
578	int	ch;		/* current character */
579	FILE	*file;		/* source */
580{
581	char	temp[MAX_TEMPSTR], *pc;
582	int	len, i, all_digits;
583
584	/* collect alphanumerics into our fixed-size temp array
585	 */
586	pc = temp;
587	len = 0;
588	all_digits = TRUE;
589	while (isalnum(ch)) {
590		if (++len >= MAX_TEMPSTR)
591			return EOF;
592
593		*pc++ = ch;
594
595		if (!isdigit(ch))
596			all_digits = FALSE;
597
598		ch = get_char(file);
599	}
600	*pc = '\0';
601	if (len == 0)
602	    return (EOF);
603
604	/* try to find the name in the name list
605	 */
606	if (names) {
607		for (i = 0;  names[i] != NULL;  i++) {
608			Debug(DPARS|DEXT,
609				("get_num, compare(%s,%s)\n", names[i], temp))
610			if (!strcasecmp(names[i], temp)) {
611				*numptr = i+low;
612				return ch;
613			}
614		}
615	}
616
617	/* no name list specified, or there is one and our string isn't
618	 * in it.  either way: if it's all digits, use its magnitude.
619	 * otherwise, it's an error.
620	 */
621	if (all_digits) {
622		*numptr = atoi(temp);
623		return ch;
624	}
625
626	return EOF;
627}
628
629
630static int
631set_element(bits, low, high, number)
632	bitstr_t	*bits; 		/* one bit per flag, default=FALSE */
633	int		low;
634	int		high;
635	int		number;
636{
637	Debug(DPARS|DEXT, ("set_element(?,%d,%d,%d)\n", low, high, number))
638
639	if (number < low || number > high)
640		return EOF;
641
642	bit_set(bits, (number-low));
643	return OK;
644}
645