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: stable/9/usr.sbin/cron/lib/entry.c 184809 2008-11-10 06:35:30Z matteo $";
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
free_entry(e)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 *
load_entry(file,error_func,pw,envp)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->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
439 static char
get_list(bits,low,high,names,ch,file)440 get_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
486 static char
get_range(bits,low,high,names,ch,file)487 get_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
573 static char
get_number(numptr,low,names,ch,file)574 get_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
630 static int
set_element(bits,low,high,number)631 set_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