1 /* Copyright 1988,1990,1993,1994 by Paul Vixie
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
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 * From Id: crontab.c,v 2.13 1994/01/17 03:20:37 vixie Exp
19 #if !defined(lint) && !defined(LINT)
20 static const char rcsid[] =
24 /* crontab - install and manage per-user crontab files
25 * vix 02may87 [RCS has the rest of the log]
26 * vix 26jan87 [original]
39 # include <sys/time.h>
49 #define NHEADER_LINES 3
52 enum opt_t { opt_unknown, opt_list, opt_delete, opt_edit, opt_replace };
55 static char *Options[] = { "???", "list", "delete", "edit", "replace" };
60 static char User[MAX_UNAME], RealUser[MAX_UNAME];
61 static char Filename[MAX_FNAME];
62 static FILE *NewCrontab;
63 static int CheckErrorCount;
64 static enum opt_t Option;
65 static struct passwd *pw;
66 static void list_cmd(void),
71 parse_args(int c, char *v[]);
72 static int replace_cmd(void);
78 fprintf(stderr, "crontab: usage error: %s\n", msg);
79 fprintf(stderr, "%s\n%s\n",
80 "usage: crontab [-u user] file",
81 " crontab [-u user] { -e | -l | -r }");
87 main(int argc, char *argv[])
92 ProgramName = argv[0];
95 setlocale(LC_ALL, "");
101 parse_args(argc, argv); /* sets many globals, opens a file */
104 if (!allowed(User)) {
105 warnx("you (%s) are not allowed to use this program", User);
106 log_it(RealUser, Pid, "AUTH", "crontab command not allowed");
109 exitstatus = OK_EXIT;
111 case opt_list: list_cmd();
113 case opt_delete: delete_cmd();
115 case opt_edit: edit_cmd();
117 case opt_replace: if (replace_cmd() < 0)
118 exitstatus = ERROR_EXIT;
129 parse_args(argc, argv)
134 char resolved_path[PATH_MAX];
136 if (!(pw = getpwuid(getuid())))
137 errx(ERROR_EXIT, "your UID isn't in the passwd file, bailing out");
138 bzero(pw->pw_passwd, strlen(pw->pw_passwd));
139 (void) strncpy(User, pw->pw_name, (sizeof User)-1);
140 User[(sizeof User)-1] = '\0';
141 strcpy(RealUser, User);
143 Option = opt_unknown;
144 while ((argch = getopt(argc, argv, "u:lerx:")) != -1) {
147 if (!set_debug_flags(optarg))
148 usage("bad debug option");
151 if (getuid() != ROOT_UID)
152 errx(ERROR_EXIT, "must be privileged to use -u");
153 if (!(pw = getpwnam(optarg)))
154 errx(ERROR_EXIT, "user `%s' unknown", optarg);
155 bzero(pw->pw_passwd, strlen(pw->pw_passwd));
156 (void) strncpy(User, pw->pw_name, (sizeof User)-1);
157 User[(sizeof User)-1] = '\0';
160 if (Option != opt_unknown)
161 usage("only one operation permitted");
165 if (Option != opt_unknown)
166 usage("only one operation permitted");
170 if (Option != opt_unknown)
171 usage("only one operation permitted");
175 usage("unrecognized option");
181 if (Option != opt_unknown) {
182 if (argv[optind] != NULL) {
183 usage("no arguments permitted after this option");
186 if (argv[optind] != NULL) {
187 Option = opt_replace;
188 (void) strncpy (Filename, argv[optind], (sizeof Filename)-1);
189 Filename[(sizeof Filename)-1] = '\0';
192 usage("file name must be specified for replace");
196 if (Option == opt_replace) {
197 /* relinquish the setuid status of the binary during
198 * the open, lest nonroot users read files they should
199 * not be able to read. we can't use access() here
200 * since there's a race condition. thanks go out to
201 * Arnt Gulbrandsen <agulbra@pvv.unit.no> for spotting
205 if (swap_uids() < OK)
206 err(ERROR_EXIT, "swapping uids");
208 /* we have to open the file here because we're going to
209 * chdir(2) into /var/cron before we get around to
212 if (!strcmp(Filename, "-")) {
214 } else if (realpath(Filename, resolved_path) != NULL &&
215 !strcmp(resolved_path, SYSCRONTAB)) {
216 err(ERROR_EXIT, SYSCRONTAB " must be edited manually");
218 if (!(NewCrontab = fopen(Filename, "r")))
219 err(ERROR_EXIT, "%s", Filename);
221 if (swap_uids_back() < OK)
222 err(ERROR_EXIT, "swapping uids back");
225 Debug(DMISC, ("user=%s, file=%s, option=%s\n",
226 User, Filename, Options[(int)Option]))
230 copy_file(FILE *in, FILE *out) {
234 /* ignore the top few comments since we probably put them there.
236 for (x = 0; x < NHEADER_LINES; x++) {
244 while (EOF != (ch = get_char(in)))
251 /* copy the rest of the crontab (if any) to the output file.
254 while (EOF != (ch = get_char(in)))
263 log_it(RealUser, Pid, "LIST", User);
264 (void) snprintf(n, sizeof(n), CRON_TAB(User));
265 if (!(f = fopen(n, "r"))) {
267 errx(ERROR_EXIT, "no crontab for %s", User);
269 err(ERROR_EXIT, "%s", n);
272 /* file is open. copy to stdout, close.
274 copy_file(f, stdout);
284 if (isatty(STDIN_FILENO)) {
285 (void)fprintf(stderr, "remove crontab for %s? ", User);
286 first = ch = getchar();
287 while (ch != '\n' && ch != EOF)
289 if (first != 'y' && first != 'Y')
293 log_it(RealUser, Pid, "DELETE", User);
294 (void) snprintf(n, sizeof(n), CRON_TAB(User));
297 errx(ERROR_EXIT, "no crontab for %s", User);
299 err(ERROR_EXIT, "%s", n);
310 fprintf(stderr, "\"%s\":%d: %s\n", Filename, LineNumber-1, msg);
316 char n[MAX_FNAME], q[MAX_TEMPSTR], *editor;
319 struct stat statbuf, fsbuf;
323 int syntax_error = 0;
324 char orig_md5[MD5_SIZE];
325 char new_md5[MD5_SIZE];
327 log_it(RealUser, Pid, "BEGIN EDIT", User);
328 (void) snprintf(n, sizeof(n), CRON_TAB(User));
329 if (!(f = fopen(n, "r"))) {
331 err(ERROR_EXIT, "%s", n);
332 warnx("no crontab for %s - using an empty one", User);
333 if (!(f = fopen(_PATH_DEVNULL, "r")))
334 err(ERROR_EXIT, _PATH_DEVNULL);
338 (void) snprintf(Filename, sizeof(Filename), "/tmp/crontab.XXXXXXXXXX");
339 if ((t = mkstemp(Filename)) == -1) {
340 warn("%s", Filename);
346 if (fchown(t, getuid(), getgid()) < 0) {
348 if (chown(Filename, getuid(), getgid()) < 0) {
353 if (!(NewCrontab = fdopen(t, "r+"))) {
358 copy_file(f, NewCrontab);
360 if (fflush(NewCrontab))
361 err(ERROR_EXIT, "%s", Filename);
362 if (fstat(t, &fsbuf) < 0) {
363 warn("unable to fstat temp file");
367 if (swap_uids() < OK)
368 err(ERROR_EXIT, "swapping uids");
369 if (stat(Filename, &statbuf) < 0) {
371 fatal: unlink(Filename);
374 if (swap_uids_back() < OK)
375 err(ERROR_EXIT, "swapping uids back");
376 if (statbuf.st_dev != fsbuf.st_dev || statbuf.st_ino != fsbuf.st_ino)
377 errx(ERROR_EXIT, "temp file must be edited in place");
378 if (MD5File(Filename, orig_md5) == NULL) {
383 if ((!(editor = getenv("VISUAL")))
384 && (!(editor = getenv("EDITOR")))
389 /* we still have the file open. editors will generally rewrite the
390 * original file rather than renaming/unlinking it and starting a
391 * new one; even backup files are supposed to be made by copying
392 * rather than by renaming. if some editor does not support this,
393 * then don't use it. the security problems are more severe if we
394 * close and reopen the file around the edit.
397 switch (pid = fork()) {
403 if (setuid(getuid()) < 0)
404 err(ERROR_EXIT, "setuid(getuid())");
405 if (chdir("/tmp") < 0)
406 err(ERROR_EXIT, "chdir(/tmp)");
407 if (strlen(editor) + strlen(Filename) + 2 >= MAX_TEMPSTR)
408 errx(ERROR_EXIT, "editor or filename too long");
409 execlp(editor, editor, Filename, (char *)NULL);
410 err(ERROR_EXIT, "%s", editor);
419 void (*sig[3])(int signal);
420 sig[0] = signal(SIGHUP, SIG_IGN);
421 sig[1] = signal(SIGINT, SIG_IGN);
422 sig[2] = signal(SIGTERM, SIG_IGN);
423 xpid = wait(&waiter);
424 signal(SIGHUP, sig[0]);
425 signal(SIGINT, sig[1]);
426 signal(SIGTERM, sig[2]);
429 warnx("wrong PID (%d != %d) from \"%s\"", xpid, pid, editor);
432 if (WIFEXITED(waiter) && WEXITSTATUS(waiter)) {
433 warnx("\"%s\" exited with status %d", editor, WEXITSTATUS(waiter));
436 if (WIFSIGNALED(waiter)) {
437 warnx("\"%s\" killed; signal %d (%score dumped)",
438 editor, WTERMSIG(waiter), WCOREDUMP(waiter) ?"" :"no ");
441 if (swap_uids() < OK)
442 err(ERROR_EXIT, "swapping uids");
443 if (stat(Filename, &statbuf) < 0) {
447 if (statbuf.st_dev != fsbuf.st_dev || statbuf.st_ino != fsbuf.st_ino)
448 errx(ERROR_EXIT, "temp file must be edited in place");
449 if (MD5File(Filename, new_md5) == NULL) {
453 if (swap_uids_back() < OK)
454 err(ERROR_EXIT, "swapping uids back");
455 if (strcmp(orig_md5, new_md5) == 0 && !syntax_error) {
456 warnx("no changes made to crontab");
459 warnx("installing new crontab");
460 switch (replace_cmd()) {
461 case 0: /* Success */
463 case -1: /* Syntax error */
465 printf("Do you want to retry the same edit? ");
468 (void) fgets(q, sizeof q, stdin);
469 switch (islower(q[0]) ? q[0] : tolower(q[0])) {
476 fprintf(stderr, "Enter Y or N\n");
480 case -2: /* Install error */
482 warnx("edits left in %s", Filename);
485 warnx("panic: bad switch() in replace_cmd()");
491 log_it(RealUser, Pid, "END EDIT", User);
495 /* returns 0 on success
497 * -2 on install error
501 char n[MAX_FNAME], envstr[MAX_ENVSTR], tn[MAX_FNAME];
505 time_t now = time(NULL);
506 char **envp = env_init();
509 warnx("cannot allocate memory");
513 (void) snprintf(n, sizeof(n), "tmp.%d", Pid);
514 (void) snprintf(tn, sizeof(tn), CRON_TAB(n));
516 if (!(tmp = fopen(tn, "w+"))) {
521 /* write a signature at the top of the file.
523 * VERY IMPORTANT: make sure NHEADER_LINES agrees with this code.
525 fprintf(tmp, "# DO NOT EDIT THIS FILE - edit the master and reinstall.\n");
526 fprintf(tmp, "# (%s installed on %-24.24s)\n", Filename, ctime(&now));
527 fprintf(tmp, "# (Cron version -- %s)\n", rcsid);
529 /* copy the crontab to the tmp
533 while (EOF != (ch = get_char(NewCrontab)))
535 ftruncate(fileno(tmp), ftell(tmp));
536 fflush(tmp); rewind(tmp);
539 warnx("error while writing new crontab to %s", tn);
540 fclose(tmp); unlink(tn);
544 /* check the syntax of the file being installed.
547 /* BUG: was reporting errors after the EOF if there were any errors
548 * in the file proper -- kludged it by stopping after first error.
551 Set_LineNum(1 - NHEADER_LINES)
552 CheckErrorCount = 0; eof = FALSE;
553 while (!CheckErrorCount && !eof) {
554 switch (load_env(envstr, tmp)) {
559 e = load_entry(tmp, check_error, pw, envp);
568 if (CheckErrorCount != 0) {
569 warnx("errors in crontab file, can't install");
570 fclose(tmp); unlink(tn);
575 if (fchown(fileno(tmp), ROOT_UID, -1) < OK)
577 if (chown(tn, ROOT_UID, -1) < OK)
581 fclose(tmp); unlink(tn);
586 if (fchmod(fileno(tmp), 0600) < OK)
588 if (chmod(tn, 0600) < OK)
592 fclose(tmp); unlink(tn);
596 if (fclose(tmp) == EOF) {
602 (void) snprintf(n, sizeof(n), CRON_TAB(User));
604 warn("error renaming %s to %s", tn, n);
609 log_it(RealUser, Pid, "REPLACE", User);
612 * Creating the 'tn' temp file has already updated the
613 * modification time of the spool directory. Sleep for a
614 * second to ensure that poke_daemon() sets a later
615 * modification time. Otherwise, this can race with the cron
616 * daemon scanning for updated crontabs.
629 struct timeval tvs[2];
632 (void) gettimeofday(&tvs[0], &tz);
634 if (utimes(SPOOL_DIR, tvs) < OK) {
635 warn("can't update mtime on spooldir %s", SPOOL_DIR);
639 if (utime(SPOOL_DIR, NULL) < OK) {
640 warn("can't update mtime on spooldir %s", SPOOL_DIR);
643 #endif /*USE_UTIMES*/