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 * $FreeBSD: src/usr.sbin/cron/lib/entry.c,v 1.9.2.5 2001/08/18 04:20:31 mikeh Exp $
18 */
19
20 /* vix 26jan87 [RCS'd; rest of log is in RCS file]
21 * vix 01jan87 [added line-level error recovery]
22 * vix 31dec86 [added /step to the from-to range, per bob@acornrc]
23 * vix 30dec86 [written]
24 */
25
26
27 #include "cron.h"
28 #include <grp.h>
29 #ifdef LOGIN_CAP
30 #include <login_cap.h>
31 #endif
32
33 typedef enum ecode {
34 e_none, e_minute, e_hour, e_dom, e_month, e_dow,
35 e_cmd, e_timespec, e_username, e_group, e_mem
36 #ifdef LOGIN_CAP
37 , e_class
38 #endif
39 } ecode_e;
40
41 static char get_list(bitstr_t *, int, int, char *[], int, FILE *),
42 get_range(bitstr_t *, int, int, char *[], int, FILE *),
43 get_number(int *, int, char *[], int, FILE *);
44 static int set_element(bitstr_t *, int, int, int);
45
46 static const char *ecodes[] =
47 {
48 "no error",
49 "bad minute",
50 "bad hour",
51 "bad day-of-month",
52 "bad month",
53 "bad day-of-week",
54 "bad command",
55 "bad time specifier",
56 "bad username",
57 "bad group name",
58 "out of memory",
59 #ifdef LOGIN_CAP
60 "bad class name",
61 #endif
62 };
63
64
65 void
free_entry(entry * e)66 free_entry(entry *e)
67 {
68 #ifdef LOGIN_CAP
69 if (e->class != NULL)
70 free(e->class);
71 #endif
72 if (e->cmd != NULL)
73 free(e->cmd);
74 if (e->envp != NULL)
75 env_free(e->envp);
76 free(e);
77 }
78
79
80 /* return NULL if eof or syntax error occurs;
81 * otherwise return a pointer to a new entry.
82 */
83 entry *
load_entry(FILE * file,void (* error_func)(const char *),struct passwd * pw,char ** envp)84 load_entry(FILE *file, void (*error_func)(const char *),
85 struct passwd *pw, char **envp)
86 {
87 /* this function reads one crontab entry -- the next -- from a file.
88 * it skips any leading blank lines, ignores comments, and returns
89 * EOF if for any reason the entry can't be read and parsed.
90 *
91 * the entry is also parsed here.
92 *
93 * syntax:
94 * user crontab:
95 * minutes hours doms months dows cmd\n
96 * system crontab (/etc/crontab):
97 * minutes hours doms months dows USERNAME cmd\n
98 */
99
100 ecode_e ecode = e_none;
101 entry *e;
102 int ch;
103 char cmd[MAX_COMMAND];
104 char envstr[MAX_ENVSTR];
105 char **prev_env;
106
107 Debug(DPARS, ("load_entry()...about to eat comments\n"))
108
109 skip_comments(file);
110
111 ch = get_char(file);
112 if (ch == EOF)
113 return NULL;
114
115 /* ch is now the first useful character of a useful line.
116 * it may be an @special or it may be the first character
117 * of a list of minutes.
118 */
119
120 e = (entry *) calloc(sizeof(entry), sizeof(char));
121
122 if (e == NULL) {
123 warn("load_entry: calloc failed");
124 return NULL;
125 }
126
127 if (ch == '@') {
128 /* all of these should be flagged and load-limited; i.e.,
129 * instead of @hourly meaning "0 * * * *" it should mean
130 * "close to the front of every hour but not 'til the
131 * system load is low". Problems are: how do you know
132 * what "low" means? (save me from /etc/cron.conf!) and:
133 * how to guarantee low variance (how low is low?), which
134 * means how to we run roughly every hour -- seems like
135 * we need to keep a history or let the first hour set
136 * the schedule, which means we aren't load-limited
137 * anymore. too much for my overloaded brain. (vix, jan90)
138 * HINT
139 */
140 Debug(DPARS, ("load_entry()...about to test shortcuts\n"))
141 ch = get_string(cmd, MAX_COMMAND, file, " \t\n");
142 if (!strcmp("reboot", cmd)) {
143 Debug(DPARS, ("load_entry()...reboot shortcut\n"))
144 e->flags |= WHEN_REBOOT;
145 } else if (!strcmp("yearly", cmd) || !strcmp("annually", cmd)){
146 Debug(DPARS, ("load_entry()...yearly shortcut\n"))
147 bit_set(e->minute, 0);
148 bit_set(e->hour, 0);
149 bit_set(e->dom, 0);
150 bit_set(e->month, 0);
151 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
152 e->flags |= DOW_STAR;
153 } else if (!strcmp("monthly", cmd)) {
154 Debug(DPARS, ("load_entry()...monthly shortcut\n"))
155 bit_set(e->minute, 0);
156 bit_set(e->hour, 0);
157 bit_set(e->dom, 0);
158 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
159 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
160 e->flags |= DOW_STAR;
161 } else if (!strcmp("weekly", cmd)) {
162 Debug(DPARS, ("load_entry()...weekly shortcut\n"))
163 bit_set(e->minute, 0);
164 bit_set(e->hour, 0);
165 bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
166 e->flags |= DOM_STAR;
167 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
168 bit_set(e->dow, 0);
169 } else if (!strcmp("daily", cmd) || !strcmp("midnight", cmd)) {
170 Debug(DPARS, ("load_entry()...daily shortcut\n"))
171 bit_set(e->minute, 0);
172 bit_set(e->hour, 0);
173 bit_nset(e->dom, 0, (LAST_DOM-FIRST_DOM+1));
174 bit_nset(e->month, 0, (LAST_MONTH-FIRST_MONTH+1));
175 bit_nset(e->dow, 0, (LAST_DOW-FIRST_DOW+1));
176 } else if (!strcmp("hourly", cmd)) {
177 Debug(DPARS, ("load_entry()...hourly shortcut\n"))
178 bit_set(e->minute, 0);
179 bit_nset(e->hour, 0, (LAST_HOUR-FIRST_HOUR+1));
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 {
184 ecode = e_timespec;
185 goto eof;
186 }
187 /* Advance past whitespace between shortcut and
188 * username/command.
189 */
190 Skip_Blanks(ch, file);
191 if (ch == EOF) {
192 ecode = e_cmd;
193 goto eof;
194 }
195 } else {
196 Debug(DPARS, ("load_entry()...about to parse numerics\n"))
197
198 ch = get_list(e->minute, FIRST_MINUTE, LAST_MINUTE,
199 NULL, ch, file);
200 if (ch == EOF) {
201 ecode = e_minute;
202 goto eof;
203 }
204
205 /* hours
206 */
207
208 ch = get_list(e->hour, FIRST_HOUR, LAST_HOUR,
209 NULL, ch, file);
210 if (ch == EOF) {
211 ecode = e_hour;
212 goto eof;
213 }
214
215 /* DOM (days of month)
216 */
217
218 if (ch == '*')
219 e->flags |= DOM_STAR;
220 ch = get_list(e->dom, FIRST_DOM, LAST_DOM,
221 NULL, ch, file);
222 if (ch == EOF) {
223 ecode = e_dom;
224 goto eof;
225 }
226
227 /* month
228 */
229
230 ch = get_list(e->month, FIRST_MONTH, LAST_MONTH,
231 MonthNames, ch, file);
232 if (ch == EOF) {
233 ecode = e_month;
234 goto eof;
235 }
236
237 /* DOW (days of week)
238 */
239
240 if (ch == '*')
241 e->flags |= DOW_STAR;
242 ch = get_list(e->dow, FIRST_DOW, LAST_DOW,
243 DowNames, ch, file);
244 if (ch == EOF) {
245 ecode = e_dow;
246 goto eof;
247 }
248 }
249
250 /* make sundays equivilent */
251 if (bit_test(e->dow, 0) || bit_test(e->dow, 7)) {
252 bit_set(e->dow, 0);
253 bit_set(e->dow, 7);
254 }
255
256 /* ch is the first character of a command, or a username */
257 unget_char(ch, file);
258
259 if (!pw) {
260 char *username = cmd; /* temp buffer */
261 char *s;
262 struct group *grp;
263 #ifdef LOGIN_CAP
264 login_cap_t *lc;
265 #endif
266
267 Debug(DPARS, ("load_entry()...about to parse username\n"))
268 ch = get_string(username, MAX_COMMAND, file, " \t");
269
270 Debug(DPARS, ("load_entry()...got %s\n",username))
271 if (ch == EOF) {
272 ecode = e_cmd;
273 goto eof;
274 }
275
276 #ifdef LOGIN_CAP
277 if ((s = strrchr(username, '/')) != NULL) {
278 *s = '\0';
279 e->class = strdup(s + 1);
280 if (e->class == NULL)
281 warn("strdup(\"%s\")", s + 1);
282 } else {
283 e->class = strdup(RESOURCE_RC);
284 if (e->class == NULL)
285 warn("strdup(\"%s\")", RESOURCE_RC);
286 }
287 if (e->class == NULL) {
288 ecode = e_mem;
289 goto eof;
290 }
291 if ((lc = login_getclass(e->class)) == NULL) {
292 ecode = e_class;
293 goto eof;
294 }
295 login_close(lc);
296 #endif
297 grp = NULL;
298 if ((s = strrchr(username, ':')) != NULL) {
299 *s = '\0';
300 if ((grp = getgrnam(s + 1)) == NULL) {
301 ecode = e_group;
302 goto eof;
303 }
304 }
305
306 pw = getpwnam(username);
307 if (pw == NULL) {
308 ecode = e_username;
309 goto eof;
310 }
311 if (grp != NULL)
312 pw->pw_gid = grp->gr_gid;
313 Debug(DPARS, ("load_entry()...uid %d, gid %d\n",pw->pw_uid,pw->pw_gid))
314 #ifdef LOGIN_CAP
315 Debug(DPARS, ("load_entry()...class %s\n",e->class))
316 #endif
317 }
318
319 if (pw->pw_expire && time(NULL) >= pw->pw_expire) {
320 ecode = e_username;
321 goto eof;
322 }
323
324 e->uid = pw->pw_uid;
325 e->gid = pw->pw_gid;
326
327 /* copy and fix up environment. some variables are just defaults and
328 * others are overrides.
329 */
330 e->envp = env_copy(envp);
331 if (e->envp == NULL) {
332 warn("env_copy");
333 ecode = e_mem;
334 goto eof;
335 }
336 if (!env_get("SHELL", e->envp)) {
337 prev_env = e->envp;
338 sprintf(envstr, "SHELL=%s", _PATH_BSHELL);
339 e->envp = env_set(e->envp, envstr);
340 if (e->envp == NULL) {
341 warn("env_set(%s)", envstr);
342 env_free(prev_env);
343 ecode = e_mem;
344 goto eof;
345 }
346 }
347 prev_env = e->envp;
348 sprintf(envstr, "HOME=%s", pw->pw_dir);
349 e->envp = env_set(e->envp, envstr);
350 if (e->envp == NULL) {
351 warn("env_set(%s)", envstr);
352 env_free(prev_env);
353 ecode = e_mem;
354 goto eof;
355 }
356 if (!env_get("PATH", e->envp)) {
357 prev_env = e->envp;
358 sprintf(envstr, "PATH=%s", _PATH_DEFPATH);
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 prev_env = e->envp;
368 sprintf(envstr, "%s=%s", "LOGNAME", pw->pw_name);
369 e->envp = env_set(e->envp, envstr);
370 if (e->envp == NULL) {
371 warn("env_set(%s)", envstr);
372 env_free(prev_env);
373 ecode = e_mem;
374 goto eof;
375 }
376 #if defined(BSD)
377 prev_env = e->envp;
378 sprintf(envstr, "%s=%s", "USER", pw->pw_name);
379 e->envp = env_set(e->envp, envstr);
380 if (e->envp == NULL) {
381 warn("env_set(%s)", envstr);
382 env_free(prev_env);
383 ecode = e_mem;
384 goto eof;
385 }
386 #endif
387
388 Debug(DPARS, ("load_entry()...about to parse command\n"))
389
390 /* Everything up to the next \n or EOF is part of the command...
391 * too bad we don't know in advance how long it will be, since we
392 * need to malloc a string for it... so, we limit it to MAX_COMMAND.
393 * XXX - should use realloc().
394 */
395 ch = get_string(cmd, MAX_COMMAND, file, "\n");
396
397 /* a file without a \n before the EOF is rude, so we'll complain...
398 */
399 if (ch == EOF) {
400 ecode = e_cmd;
401 goto eof;
402 }
403
404 /* got the command in the 'cmd' string; save it in *e.
405 */
406 e->cmd = strdup(cmd);
407 if (e->cmd == NULL) {
408 warn("strdup(\"%s\")", cmd);
409 ecode = e_mem;
410 goto eof;
411 }
412 Debug(DPARS, ("load_entry()...returning successfully\n"))
413
414 /* success, fini, return pointer to the entry we just created...
415 */
416 return e;
417
418 eof:
419 free_entry(e);
420 if (ecode != e_none && error_func)
421 (*error_func)(ecodes[(int)ecode]);
422 while (ch != EOF && ch != '\n')
423 ch = get_char(file);
424 return NULL;
425 }
426
427 /*
428 * bits; one bit per flag, default=FALSE
429 * low, high bounds, impl. offset for bitstr
430 * names NULL or *[] of names for these elements
431 * ch current character being processed
432 * file file being read
433 */
434 static char
get_list(bitstr_t * bits,int low,int high,char ** names,int ch,FILE * file)435 get_list(bitstr_t *bits, int low, int high, char **names, int ch, FILE *file)
436 {
437 int done;
438
439 /* we know that we point to a non-blank character here;
440 * must do a Skip_Blanks before we exit, so that the
441 * next call (or the code that picks up the cmd) can
442 * assume the same thing.
443 */
444
445 Debug(DPARS|DEXT, ("get_list()...entered\n"))
446
447 /* list = range {"," range}
448 */
449
450 /* clear the bit string, since the default is 'off'.
451 */
452 bit_nclear(bits, 0, (high-low+1));
453
454 /* process all ranges
455 */
456 done = FALSE;
457 while (!done) {
458 ch = get_range(bits, low, high, names, ch, file);
459 if (ch == ',')
460 ch = get_char(file);
461 else
462 done = TRUE;
463 }
464
465 /* exiting. skip to some blanks, then skip over the blanks.
466 */
467 Skip_Nonblanks(ch, file)
468 Skip_Blanks(ch, file)
469
470 Debug(DPARS|DEXT, ("get_list()...exiting w/ %02x\n", ch))
471
472 return ch;
473 }
474
475
476 static char
get_range(bitstr_t * bits,int low,int high,char ** names,int ch,FILE * file)477 get_range(bitstr_t *bits, int low, int high, char **names, int ch, FILE *file)
478 {
479 /* range = number | number "-" number [ "/" number ]
480 */
481
482 int i;
483 int num1, num2, num3;
484
485 Debug(DPARS|DEXT, ("get_range()...entering, exit won't show\n"))
486
487 if (ch == '*') {
488 /* '*' means "first-last" but can still be modified by /step
489 */
490 num1 = low;
491 num2 = high;
492 ch = get_char(file);
493 if (ch == EOF)
494 return EOF;
495 } else {
496 if (EOF == (ch = get_number(&num1, low, names, ch, file)))
497 return EOF;
498
499 if (ch != '-') {
500 /* not a range, it's a single number.
501 */
502 if (EOF == set_element(bits, low, high, num1))
503 return EOF;
504 return ch;
505 } else {
506 /* eat the dash
507 */
508 ch = get_char(file);
509 if (ch == EOF)
510 return EOF;
511
512 /* get the number following the dash
513 */
514 ch = get_number(&num2, low, names, ch, file);
515 if (ch == EOF)
516 return EOF;
517 }
518 }
519
520 /* check for step size
521 */
522 if (ch == '/') {
523 /* eat the slash
524 */
525 ch = get_char(file);
526 if (ch == EOF)
527 return EOF;
528
529 /* get the step size -- note: we don't pass the
530 * names here, because the number is not an
531 * element id, it's a step size. 'low' is
532 * sent as a 0 since there is no offset either.
533 */
534 ch = get_number(&num3, 0, NULL, ch, file);
535 if (ch == EOF || num3 == 0)
536 return EOF;
537 } else {
538 /* no step. default==1.
539 */
540 num3 = 1;
541 }
542
543 /* range. set all elements from num1 to num2, stepping
544 * by num3. (the step is a downward-compatible extension
545 * proposed conceptually by bob@acornrc, syntactically
546 * designed then implmented by paul vixie).
547 */
548 for (i = num1; i <= num2; i += num3)
549 if (EOF == set_element(bits, low, high, i))
550 return EOF;
551
552 return ch;
553 }
554
555 /*
556 * numptr where does the result go?
557 * low offset applied to result if symbolic enum used
558 * names symbolic names, if any, for enums
559 * ch current character
560 * file source
561 */
562 static char
get_number(int * numptr,int low,char ** names,int ch,FILE * file)563 get_number(int *numptr, int low, char **names, int ch, FILE *file)
564 {
565 char temp[MAX_TEMPSTR], *pc;
566 int len, i, all_digits;
567
568 /* collect alphanumerics into our fixed-size temp array
569 */
570 pc = temp;
571 len = 0;
572 all_digits = TRUE;
573 while (isalnum(ch)) {
574 if (++len >= MAX_TEMPSTR)
575 return EOF;
576
577 *pc++ = ch;
578
579 if (!isdigit(ch))
580 all_digits = FALSE;
581
582 ch = get_char(file);
583 }
584 *pc = '\0';
585 if (len == 0)
586 return EOF;
587
588 /* try to find the name in the name list
589 */
590 if (names) {
591 for (i = 0; names[i] != NULL; i++) {
592 Debug(DPARS|DEXT,
593 ("get_num, compare(%s,%s)\n", names[i], temp))
594 if (!strcasecmp(names[i], temp)) {
595 *numptr = i+low;
596 return ch;
597 }
598 }
599 }
600
601 /* no name list specified, or there is one and our string isn't
602 * in it. either way: if it's all digits, use its magnitude.
603 * otherwise, it's an error.
604 */
605 if (all_digits) {
606 *numptr = atoi(temp);
607 return ch;
608 }
609
610 return EOF;
611 }
612
613
614 static int
set_element(bitstr_t * bits,int low,int high,int number)615 set_element(bitstr_t *bits, int low, int high, int number)
616 {
617 Debug(DPARS|DEXT, ("set_element(?,%d,%d,%d)\n", low, high, number))
618
619 if (number < low || number > high)
620 return EOF;
621
622 bit_set(bits, (number-low));
623 return OK;
624 }
625