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26#define FOR_crond
27#include "toys.h"
28
29GLOBALS(
30 char *crontabs_dir;
31 char *logfile;
32 int loglevel_d;
33 int loglevel;
34
35 time_t crontabs_dir_mtime;
36 uint8_t flagd;
37)
38
39typedef struct _var {
40 struct _var *next, *prev;
41 char *name, *val;
42} VAR;
43
44typedef struct _job {
45 struct _job *next, *prev;
46 char min[60], hour[24], dom[31], mon[12], dow[7], *cmd;
47 int isrunning, needstart, mailsize;
48 pid_t pid;
49} JOB;
50
51typedef struct _cronfile {
52 struct _cronfile *next, *prev;
53 struct double_list *job, *var;
54 char *username, *mailto;
55 int invalid;
56} CRONFILE;
57
58static char days[]={"sun""mon""tue""wed""thu""fri""sat"};
59static char months[]={"jan""feb""mar""apr""may""jun""jul"
60 "aug""sep""oct""nov""dec"};
61CRONFILE *gclist;
62
63#define LOG_EXIT 0
64#define LOG_LEVEL5 5
65#define LOG_LEVEL7 7
66#define LOG_LEVEL8 8
67#define LOG_LEVEL9 9
68#define LOG_ERROR 20
69
70static void loginfo(uint8_t loglevel, char *msg, ...)
71{
72 va_list s, d;
73
74 va_start(s, msg);
75 va_copy(d, s);
76 if (loglevel >= TT.loglevel) {
77 int used;
78 char *smsg;
79
80 if (!TT.flagd && TT.logfile) {
81 int fd = open(TT.logfile, O_WRONLY | O_CREAT | O_APPEND, 0666);
82 if (fd==-1) perror_msg("'%s", TT.logfile);
83 else {
84 dup2(fd, 2);
85 close(fd);
86 }
87 }
88 used = vsnprintf(NULL, 0, msg, d);
89 smsg = xzalloc(++used);
90 vsnprintf(smsg, used, msg, s);
91 if (TT.flagd || TT.logfile) {
92 fflush(NULL);
93 smsg[used-1] = '\n';
94 writeall((loglevel > 8) ? 2 : 1, smsg, used);
95 } else syslog((loglevel > 8) ? LOG_ERR : LOG_INFO, "%s", smsg);
96 free(smsg);
97 }
98 va_end(d);
99 va_end(s);
100 if (!loglevel) exit(20);
101}
102
103
104
105
106
107static int getindex(char *src, int size)
108{
109 int i;
110 char *field = (size == 12) ? months : days;
111
112
113 if (!(size == 7 || size == 12)) return -1;
114
115 for (i = 0; field[i]; i += 3) {
116 if (!strncasecmp(src, &field[i], 3))
117 return (i/3);
118 }
119 return -1;
120}
121
122
123static void fillarray(char *dst, int start, int end, int skip)
124{
125 int sk = 1;
126
127 if (end < 0) {
128 dst[start] = 1;
129 return;
130 }
131 if (!skip) skip = 1;
132 do {
133 if (!--sk) {
134 dst[start] = 1;
135 sk = skip;
136 }
137 } while (start++ != end);
138}
139
140static long getval(char *num, long low, long high)
141{
142 long val = strtol(num, &num, 10);
143
144 if (*num || (val < low) || (val > high)) return -1;
145 return val;
146}
147
148
149static int parse_and_fillarray(char *dst, int min, int max, char *src)
150{
151 int start, end, skip = 0;
152 char *ptr = strchr(src, '/');
153
154 if (ptr) {
155 *ptr++ = 0;
156 if ((skip = getval(ptr, min, (min ? max: max-1))) < 0) goto ERROR;
157 }
158
159 if (*src == '-' || *src == ',') goto ERROR;
160 if (*src == '*') {
161 if (*(src+1)) goto ERROR;
162 fillarray(dst, 0, max-1, skip);
163 } else {
164 for (;;) {
165 char *ctoken = strsep(&src, ","), *dtoken;
166
167 if (!ctoken) break;
168 if (!*ctoken) goto ERROR;
169
170
171 dtoken = strsep(&ctoken, "-");
172 if (isdigit(*dtoken)) {
173 if ((start = getval(dtoken, min, (min ? max : max-1))) < 0) goto ERROR;
174 start = min ? (start-1) : start;
175 } else if ((start = getindex(dtoken, max)) < 0) goto ERROR;
176
177
178 if (!ctoken) end = -1;
179 else if (*ctoken) {
180 if (isdigit(*ctoken)) {
181 if ((end = getval(ctoken, min, (min ? max : max-1))) < 0) goto ERROR;
182 end = min ? (end-1) : end;
183 } else if ((end = getindex(ctoken, max)) < 0) goto ERROR;
184 if (end == start) end = -1;
185 } else goto ERROR;
186 fillarray(dst, start, end, skip);
187 }
188 }
189
190 if (TT.flagd && (TT.loglevel <= 5)) {
191 for (start = 0; start < max; start++)
192 fprintf(stderr, "%d", (unsigned char)dst[start]);
193 fputc('\n', stderr);
194 }
195 return 0;
196ERROR:
197 loginfo(LOG_LEVEL9, "parse error at %s", src);
198 return -1;
199}
200
201static char *omitspace(char *line)
202{
203 while (*line == ' ' || *line == '\t') line++;
204 return line;
205}
206
207static void parse_line(char *line, CRONFILE *cfile)
208{
209 int count = 0;
210 char *name, *val, *tokens[5] = {0,};
211 VAR *v;
212 JOB *j;
213
214 line = omitspace(line);
215 if (!*line || *line == '#') return;
216
217
218
219
220
221
222
223
224
225
226
227
228 if (*line == '@') return;
229 if (TT.flagd) loginfo(LOG_LEVEL5, "user:%s entry:%s", cfile->username, line);
230 while (count<5) {
231 int len = strcspn(line, " \t");
232
233 if (line[len]) line[len++] = '\0';
234 tokens[count++] = line;
235 line += len;
236 line = omitspace(line);
237 if (!*line) break;
238 }
239
240 switch (count) {
241 case 1:
242 name = tokens[0];
243 if ((val = strchr(name, '='))) *val++ = 0;
244 if (!val || !*val) return;
245 break;
246 case 2:
247 name = tokens[0];
248 if ((val = strchr(name, '='))) {
249 *val = 0;
250 val = tokens[1];
251 } else {
252 if (*(tokens[1]) != '=') return;
253 val = tokens[1] + 1;
254 }
255 if (!*val) return;
256 break;
257 case 3:
258 name = tokens[0];
259 val = tokens[2];
260 if (*(tokens[1]) != '=') return;
261 break;
262 case 5:
263
264 if (!*line) return;
265 j = xzalloc(sizeof(JOB));
266
267 if (parse_and_fillarray(j->min, 0, sizeof(j->min), tokens[0]))
268 goto STOP_PARSING;
269 if (parse_and_fillarray(j->hour, 0, sizeof(j->hour), tokens[1]))
270 goto STOP_PARSING;
271 if (parse_and_fillarray(j->dom, 1, sizeof(j->dom), tokens[2]))
272 goto STOP_PARSING;
273 if (parse_and_fillarray(j->mon, 1, sizeof(j->mon), tokens[3]))
274 goto STOP_PARSING;
275 if (parse_and_fillarray(j->dow, 0, sizeof(j->dow), tokens[4]))
276 goto STOP_PARSING;
277 j->cmd = xstrdup(line);
278
279 if (TT.flagd) loginfo(LOG_LEVEL5, " command:%s", j->cmd);
280 dlist_add_nomalloc((struct double_list **)&cfile->job, (struct double_list *)j);
281 return;
282STOP_PARSING:
283 free(j);
284 return;
285 default: return;
286 }
287 if (!strcmp(name, "MAILTO")) cfile->mailto = xstrdup(val);
288 else {
289 v = xzalloc(sizeof(VAR));
290 v->name = xstrdup(name);
291 v->val = xstrdup(val);
292 dlist_add_nomalloc((struct double_list **)&cfile->var, (struct double_list *)v);
293 }
294}
295
296static void free_jobs(JOB **jlist)
297{
298 JOB *j = dlist_pop(jlist);
299 free(j->cmd);
300 free(j);
301}
302
303static void free_cronfile(CRONFILE **list)
304{
305 CRONFILE *l = dlist_pop(list);
306 VAR *v, *vnode = (VAR *)l->var;
307
308 if (l->username != l->mailto) free(l->mailto);
309 free(l->username);
310 while (vnode && (v = dlist_pop(&vnode))) {
311 free(v->name);
312 free(v->val);
313 free(v);
314 }
315 free(l);
316}
317
318
319
320
321
322static void remove_completed_jobs()
323{
324 CRONFILE *lstart, *list = gclist;
325
326 lstart = list;
327 while (list) {
328 int delete = 1;
329 JOB *jstart, *jlist = (JOB *)list->job;
330
331 list->invalid = 1;
332 jstart = jlist;
333 while (jlist) {
334 jlist->isrunning = 0;
335 if (jlist->pid > 0) {
336 jlist->isrunning = 1;
337 delete = 0;
338 jlist = jlist->next;
339 } else {
340 if (jlist == jstart) {
341 jstart = jstart->next;
342 free_jobs(&jlist);
343 continue;
344 } else free_jobs(&jlist);
345 }
346 if (jlist == jstart) break;
347 }
348 list->job = (struct double_list *)jlist;
349
350 if (delete) {
351 if (lstart == list) {
352 lstart = lstart->next;
353 free_cronfile(&list);
354 continue;
355 } else free_cronfile(&list);
356 }
357 list = list->next;
358 if (lstart == list) break;
359 }
360 gclist = list;
361}
362
363
364static void scan_cronfiles()
365{
366 DIR *dp;
367 struct dirent *entry;
368
369 remove_completed_jobs();
370 if (chdir(TT.crontabs_dir)) loginfo(LOG_EXIT, "chdir(%s)", TT.crontabs_dir);
371 if (!(dp = opendir("."))) loginfo(LOG_EXIT, "chdir(%s)", ".");
372
373 while ((entry = readdir(dp))) {
374 int fd;
375 char *line;
376 CRONFILE *cfile;
377
378 if (entry->d_name[0] == '.' && (!entry->d_name[1] ||
379 (entry->d_name[1] == '.' && !entry->d_name[2])))
380 continue;
381
382 if (!getpwnam(entry->d_name)) {
383 loginfo(LOG_LEVEL7, "ignoring file '%s' (no such user)", entry->d_name);
384 continue;
385 }
386 if ((fd = open(entry->d_name, O_RDONLY)) < 0) continue;
387
388
389 cfile = xzalloc(sizeof(CRONFILE));
390 cfile->username = xstrdup(entry->d_name);
391
392 for (; (line = get_line(fd)); free(line))
393 parse_line(line, cfile);
394
395
396 if (!cfile->job) {
397 VAR *v, *vnode = (VAR *)cfile->var;
398
399 free(cfile->username);
400 if (cfile->mailto) free(cfile->mailto);
401
402 while (vnode && (v = dlist_pop(&vnode))) {
403 free(v->name);
404 free(v->val);
405 free(v);
406 }
407 free(cfile);
408 } else {
409 if (!cfile->mailto) cfile->mailto = cfile->username;
410 dlist_add_nomalloc((struct double_list **)&gclist,
411 (struct double_list *)cfile);
412 }
413 close(fd);
414 }
415 closedir(dp);
416}
417
418
419
420
421
422
423static void do_fork(CRONFILE *cfile, JOB *job, int fd, char *prog)
424{
425 pid_t pid = vfork();
426
427 if (pid == 0) {
428 VAR *v, *vstart = (VAR *)cfile->var;
429 struct passwd *pwd = getpwnam(cfile->username);
430
431 if (!pwd) loginfo(LOG_LEVEL9, "can't get uid for %s", cfile->username);
432 else {
433 char *file = "/bin/sh";
434
435 if (setenv("USER", pwd->pw_name, 1)) _exit(1);
436 for (v = vstart; v;) {
437 if (!strcmp("SHELL", v->name)) file = v->val;
438 if (setenv(v->name, v->val, 1)) _exit(1);
439 if ((v=v->next) == vstart) break;
440 }
441 if (!getenv("HOME")) {
442 if (setenv("HOME", pwd->pw_dir, 1))
443 _exit(1);
444 }
445 xsetuser(pwd);
446 if (chdir(pwd->pw_dir)) loginfo(LOG_LEVEL9, "chdir(%s)", pwd->pw_dir);
447 if (prog) file = prog;
448 if (TT.flagd) loginfo(LOG_LEVEL5, "child running %s", file);
449
450 if (fd >= 0) {
451 int newfd = prog ? 0 : 1;
452 if (fd != newfd) {
453 dup2(fd, newfd);
454 close(fd);
455 }
456 dup2(1, 2);
457 }
458 setpgrp();
459 execlp(file, file, (prog ? "-ti" : "-c"), (prog ? NULL : job->cmd), (char *) NULL);
460 loginfo(LOG_ERROR, "can't execute '%s' for user %s", file, cfile->username);
461
462 if (!prog) dprintf(1, "Exec failed: %s -c %s\n", file, job->cmd);
463 _exit(EXIT_SUCCESS);
464 }
465 }
466 if (pid < 0) {
467 loginfo(LOG_ERROR, "can't vfork");
468 pid = 0;
469 }
470 if (fd >=0) close(fd);
471 job->pid = pid;
472}
473
474
475static void sendmail(CRONFILE *cfile, JOB *job)
476{
477 pid_t pid = job->pid;
478 int mailfd;
479 struct stat sb;
480
481 job->pid = 0;
482 if (pid <=0 || job->mailsize <=0) {
483 job->isrunning = 0;
484 job->needstart = 1;
485 return;
486 }
487 snprintf(toybuf, sizeof(toybuf), "/var/spool/cron/cron.%s.%d",
488 cfile->username, (int)pid);
489
490 mailfd = open(toybuf, O_RDONLY);
491 unlink(toybuf);
492 if (mailfd < 0) return;
493
494 if (fstat(mailfd, &sb) == -1 || sb.st_uid != 0 || sb.st_nlink != 0
495 || sb.st_size == job->mailsize || !S_ISREG(sb.st_mode)) {
496 xclose(mailfd);
497 return;
498 }
499 job->mailsize = 0;
500 do_fork(cfile, job, mailfd, "sendmail");
501}
502
503
504static int count_running_jobs()
505{
506 CRONFILE *cfile = gclist;
507 JOB *job, *jstart;
508 int count = 0;
509
510 while (cfile) {
511 job = jstart = (JOB *)cfile->job;
512 while (job) {
513 int ret;
514
515 if (!job->isrunning || job->pid<=0) goto NEXT_JOB;
516 job->isrunning = 0;
517 ret = waitpid(job->pid, NULL, WNOHANG);
518 if (ret < 0 || ret == job->pid) {
519 sendmail(cfile, job);
520 if (job->pid) count += (job->isrunning=1);
521 else {
522 job->isrunning = 0;
523 job->needstart = 1;
524 }
525 }
526 else count += (job->isrunning=1);
527
528NEXT_JOB:
529 if ((job = job->next) == jstart) break;
530 }
531 if ((cfile = cfile->next) == gclist) break;
532 }
533 return count;
534}
535
536
537static void execute_jobs(void)
538{
539 CRONFILE *cfile = gclist;
540 JOB *job, *jstart;
541
542 while (cfile) {
543 job = jstart = (JOB *)cfile->job;
544 while (job) {
545 if (job->needstart) {
546 job->needstart = 0;
547 if (job->pid < 0) {
548 int mailfd = -1;
549
550 job->mailsize = job->pid = 0;
551 snprintf(toybuf, sizeof(toybuf), "/var/spool/cron/cron.%s.%d",
552 cfile->username, getpid());
553 if ((mailfd = open(toybuf, O_CREAT|O_TRUNC|O_WRONLY|O_EXCL|O_APPEND,
554 0600)) < 0) {
555 loginfo(LOG_ERROR, "can't create mail file %s for user %s, "
556 "discarding output", toybuf, cfile->username);
557 } else {
558 dprintf(mailfd, "To: %s\nSubject: cron: %s\n\n", cfile->mailto, job->cmd);
559 job->mailsize = lseek(mailfd, 0, SEEK_CUR);
560 }
561 do_fork(cfile, job, mailfd, NULL);
562 if (mailfd >= 0) {
563 if (job->pid <= 0) unlink(toybuf);
564 else {
565 char *mailfile = xmprintf("/var/spool/cron/cron.%s.%d",
566 cfile->username, (int)job->pid);
567 rename(toybuf, mailfile);
568 free(mailfile);
569 }
570 }
571 loginfo(LOG_LEVEL8, "USER %s pid %3d cmd %s",
572 cfile->username, job->pid, job->cmd);
573 if (job->pid < 0) job->needstart = 1;
574 else job->isrunning = 1;
575 }
576 }
577 if ((job = job->next) == jstart) break;
578 }
579 if ((cfile = cfile->next) == gclist) break;
580 }
581}
582
583
584static void schedule_jobs(time_t ctime, time_t ptime)
585{
586 time_t tm = ptime-ptime%60;
587
588 for (; tm <= ctime; tm += 60) {
589 struct tm *lt;
590 CRONFILE *cfile = gclist;
591 JOB *job, *jstart;
592
593 if (tm <= ptime) continue;
594 lt = localtime(&tm);
595
596 while (cfile) {
597 if (TT.flagd) loginfo(LOG_LEVEL5, "file %s:", cfile->username);
598 if (cfile->invalid) goto NEXT_CRONFILE;
599 job = jstart = (JOB *)cfile->job;
600
601 while (job) {
602 if (TT.flagd) loginfo(LOG_LEVEL5, " line %s", job->cmd);
603
604 if (job->min[lt->tm_min] && job->hour[lt->tm_hour]
605 && (job->dom[lt->tm_mday] || job->dow[lt->tm_wday])
606 && job->mon[lt->tm_mon-1]) {
607 if (TT.flagd)
608 loginfo(LOG_LEVEL5, " job: %d %s\n", (int)job->pid, job->cmd);
609 if (job->pid > 0) {
610 loginfo(LOG_LEVEL8, "user %s: process already running: %s",
611 cfile->username, job->cmd);
612 } else if (!job->pid) {
613 job->pid = -1;
614 job->needstart = 1;
615 job->isrunning = 0;
616 }
617 }
618 if ((job = job->next) == jstart) break;
619 }
620NEXT_CRONFILE:
621 if ((cfile = cfile->next) == gclist) break;
622 }
623 }
624}
625
626void crond_main(void)
627{
628 time_t ctime, ptime;
629 int sleepfor = 60;
630 struct stat sb;
631
632 TT.flagd = (toys.optflags & FLAG_d);
633
634
635 if (TT.flagd) TT.loglevel = TT.loglevel_d;
636 if (!(toys.optflags & (FLAG_f | FLAG_b))) toys.optflags |= FLAG_b;
637 if (!(toys.optflags & (FLAG_S | FLAG_L))) toys.optflags |= FLAG_S;
638
639 if ((toys.optflags & FLAG_c)
640 && (TT.crontabs_dir[strlen(TT.crontabs_dir)-1] != '/'))
641 TT.crontabs_dir = xmprintf("%s/", TT.crontabs_dir);
642
643 if (!TT.crontabs_dir) TT.crontabs_dir = xstrdup("/var/spool/cron/crontabs/");
644 if (toys.optflags & FLAG_b) daemon(0,0);
645
646 if (!TT.flagd && !TT.logfile)
647 openlog(toys.which->name, LOG_CONS | LOG_PID, LOG_CRON);
648
649
650 if (setenv("SHELL", "/bin/sh", 1)) error_exit("Can't set default shell");
651 xchdir(TT.crontabs_dir);
652 loginfo(LOG_LEVEL8, "crond started, log level %d", TT.loglevel);
653
654 if (stat(TT.crontabs_dir, &sb)) sb.st_mtime = 0;
655 TT.crontabs_dir_mtime = sb.st_mtime;
656 scan_cronfiles();
657 ctime = time(NULL);
658
659 while (1) {
660 long tdiff;
661
662 ptime = ctime;
663 sleep(sleepfor - (ptime%sleepfor) +1);
664 tdiff =(long) ((ctime = time(NULL)) - ptime);
665
666 if (stat(TT.crontabs_dir, &sb)) sb.st_mtime = 0;
667 if (TT.crontabs_dir_mtime != sb.st_mtime) {
668 TT.crontabs_dir_mtime = sb.st_mtime;
669 scan_cronfiles();
670 }
671
672 if (TT.flagd) loginfo(LOG_LEVEL5, "wakeup diff=%ld\n", tdiff);
673 if (tdiff < -60 * 60 || tdiff > 60 * 60)
674 loginfo(LOG_LEVEL9, "time disparity of %ld minutes detected", tdiff / 60);
675 else if (tdiff > 0) {
676 schedule_jobs(ctime, ptime);
677 execute_jobs();
678 if (count_running_jobs()) sleepfor = 10;
679 else sleepfor = 60;
680 }
681 }
682}
683
