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]
31 #include <sys/param.h>
40 # include <sys/time.h>
50 #define NHEADER_LINES 3
53 enum opt_t { opt_unknown, opt_list, opt_delete, opt_edit, opt_replace };
56 static char *Options[] = { "???", "list", "delete", "edit", "replace" };
61 static char User[MAXLOGNAME], RealUser[MAXLOGNAME];
62 static char Filename[MAX_FNAME];
63 static FILE *NewCrontab;
64 static int CheckErrorCount;
65 static enum opt_t Option;
66 static struct passwd *pw;
67 static void list_cmd(void),
72 parse_args(int c, char *v[]);
73 static int replace_cmd(void);
79 fprintf(stderr, "crontab: usage error: %s\n", msg);
80 fprintf(stderr, "%s\n%s\n",
81 "usage: crontab [-u user] file",
82 " crontab [-u user] { -e | -l | -r }");
88 main(int argc, char *argv[])
93 ProgramName = argv[0];
96 setlocale(LC_ALL, "");
102 parse_args(argc, argv); /* sets many globals, opens a file */
105 if (!allowed(User)) {
106 warnx("you (%s) are not allowed to use this program", User);
107 log_it(RealUser, Pid, "AUTH", "crontab command not allowed");
110 exitstatus = OK_EXIT;
112 case opt_list: list_cmd();
114 case opt_delete: delete_cmd();
116 case opt_edit: edit_cmd();
118 case opt_replace: if (replace_cmd() < 0)
119 exitstatus = ERROR_EXIT;
130 parse_args(argc, argv)
135 char resolved_path[PATH_MAX];
137 if (!(pw = getpwuid(getuid())))
138 errx(ERROR_EXIT, "your UID isn't in the passwd file, bailing out");
139 bzero(pw->pw_passwd, strlen(pw->pw_passwd));
140 (void) strncpy(User, pw->pw_name, (sizeof User)-1);
141 User[(sizeof User)-1] = '\0';
142 strcpy(RealUser, User);
144 Option = opt_unknown;
145 while ((argch = getopt(argc, argv, "u:lerx:")) != -1) {
148 if (!set_debug_flags(optarg))
149 usage("bad debug option");
152 if (getuid() != ROOT_UID)
153 errx(ERROR_EXIT, "must be privileged to use -u");
154 if (!(pw = getpwnam(optarg)))
155 errx(ERROR_EXIT, "user `%s' unknown", optarg);
156 bzero(pw->pw_passwd, strlen(pw->pw_passwd));
157 (void) strncpy(User, pw->pw_name, (sizeof User)-1);
158 User[(sizeof User)-1] = '\0';
161 if (Option != opt_unknown)
162 usage("only one operation permitted");
166 if (Option != opt_unknown)
167 usage("only one operation permitted");
171 if (Option != opt_unknown)
172 usage("only one operation permitted");
176 usage("unrecognized option");
182 if (Option != opt_unknown) {
183 if (argv[optind] != NULL) {
184 usage("no arguments permitted after this option");
187 if (argv[optind] != NULL) {
188 Option = opt_replace;
189 (void) strncpy (Filename, argv[optind], (sizeof Filename)-1);
190 Filename[(sizeof Filename)-1] = '\0';
193 usage("file name must be specified for replace");
197 if (Option == opt_replace) {
198 /* relinquish the setuid status of the binary during
199 * the open, lest nonroot users read files they should
200 * not be able to read. we can't use access() here
201 * since there's a race condition. thanks go out to
202 * Arnt Gulbrandsen <agulbra@pvv.unit.no> for spotting
206 if (swap_uids() < OK)
207 err(ERROR_EXIT, "swapping uids");
209 /* we have to open the file here because we're going to
210 * chdir(2) into /var/cron before we get around to
213 if (!strcmp(Filename, "-")) {
215 } else if (realpath(Filename, resolved_path) != NULL &&
216 !strcmp(resolved_path, SYSCRONTAB)) {
217 err(ERROR_EXIT, SYSCRONTAB " must be edited manually");
219 if (!(NewCrontab = fopen(Filename, "r")))
220 err(ERROR_EXIT, "%s", Filename);
222 if (swap_uids_back() < OK)
223 err(ERROR_EXIT, "swapping uids back");
226 Debug(DMISC, ("user=%s, file=%s, option=%s\n",
227 User, Filename, Options[(int)Option]))
231 copy_file(FILE *in, FILE *out) {
235 /* ignore the top few comments since we probably put them there.
237 for (x = 0; x < NHEADER_LINES; x++) {
245 while (EOF != (ch = get_char(in)))
252 /* copy the rest of the crontab (if any) to the output file.
255 while (EOF != (ch = get_char(in)))
264 log_it(RealUser, Pid, "LIST", User);
265 (void) snprintf(n, sizeof(n), CRON_TAB(User));
266 if (!(f = fopen(n, "r"))) {
268 errx(ERROR_EXIT, "no crontab for %s", User);
270 err(ERROR_EXIT, "%s", n);
273 /* file is open. copy to stdout, close.
275 copy_file(f, stdout);
285 if (isatty(STDIN_FILENO)) {
286 (void)fprintf(stderr, "remove crontab for %s? ", User);
287 first = ch = getchar();
288 while (ch != '\n' && ch != EOF)
290 if (first != 'y' && first != 'Y')
294 log_it(RealUser, Pid, "DELETE", User);
295 (void) snprintf(n, sizeof(n), CRON_TAB(User));
298 errx(ERROR_EXIT, "no crontab for %s", User);
300 err(ERROR_EXIT, "%s", n);
311 fprintf(stderr, "\"%s\":%d: %s\n", Filename, LineNumber-1, msg);
317 char n[MAX_FNAME], q[MAX_TEMPSTR], *editor;
320 struct stat statbuf, fsbuf;
324 int syntax_error = 0;
325 char orig_md5[MD5_SIZE];
326 char new_md5[MD5_SIZE];
328 log_it(RealUser, Pid, "BEGIN EDIT", User);
329 (void) snprintf(n, sizeof(n), CRON_TAB(User));
330 if (!(f = fopen(n, "r"))) {
332 err(ERROR_EXIT, "%s", n);
333 warnx("no crontab for %s - using an empty one", User);
334 if (!(f = fopen(_PATH_DEVNULL, "r")))
335 err(ERROR_EXIT, _PATH_DEVNULL);
339 (void) snprintf(Filename, sizeof(Filename), "/tmp/crontab.XXXXXXXXXX");
340 if ((t = mkstemp(Filename)) == -1) {
341 warn("%s", Filename);
347 if (fchown(t, getuid(), getgid()) < 0) {
349 if (chown(Filename, getuid(), getgid()) < 0) {
354 if (!(NewCrontab = fdopen(t, "r+"))) {
359 copy_file(f, NewCrontab);
361 if (fflush(NewCrontab))
362 err(ERROR_EXIT, "%s", Filename);
363 if (fstat(t, &fsbuf) < 0) {
364 warn("unable to fstat temp file");
368 if (swap_uids() < OK)
369 err(ERROR_EXIT, "swapping uids");
370 if (stat(Filename, &statbuf) < 0) {
372 fatal: unlink(Filename);
375 if (swap_uids_back() < OK)
376 err(ERROR_EXIT, "swapping uids back");
377 if (statbuf.st_dev != fsbuf.st_dev || statbuf.st_ino != fsbuf.st_ino)
378 errx(ERROR_EXIT, "temp file must be edited in place");
379 if (MD5File(Filename, orig_md5) == NULL) {
384 if ((!(editor = getenv("VISUAL")))
385 && (!(editor = getenv("EDITOR")))
390 /* we still have the file open. editors will generally rewrite the
391 * original file rather than renaming/unlinking it and starting a
392 * new one; even backup files are supposed to be made by copying
393 * rather than by renaming. if some editor does not support this,
394 * then don't use it. the security problems are more severe if we
395 * close and reopen the file around the edit.
398 switch (pid = fork()) {
404 if (setuid(getuid()) < 0)
405 err(ERROR_EXIT, "setuid(getuid())");
406 if (chdir("/tmp") < 0)
407 err(ERROR_EXIT, "chdir(/tmp)");
408 if (strlen(editor) + strlen(Filename) + 2 >= MAX_TEMPSTR)
409 errx(ERROR_EXIT, "editor or filename too long");
410 execlp(editor, editor, Filename, (char *)NULL);
411 err(ERROR_EXIT, "%s", editor);
420 void (*sig[3])(int signal);
421 sig[0] = signal(SIGHUP, SIG_IGN);
422 sig[1] = signal(SIGINT, SIG_IGN);
423 sig[2] = signal(SIGTERM, SIG_IGN);
424 xpid = wait(&waiter);
425 signal(SIGHUP, sig[0]);
426 signal(SIGINT, sig[1]);
427 signal(SIGTERM, sig[2]);
430 warnx("wrong PID (%d != %d) from \"%s\"", xpid, pid, editor);
433 if (WIFEXITED(waiter) && WEXITSTATUS(waiter)) {
434 warnx("\"%s\" exited with status %d", editor, WEXITSTATUS(waiter));
437 if (WIFSIGNALED(waiter)) {
438 warnx("\"%s\" killed; signal %d (%score dumped)",
439 editor, WTERMSIG(waiter), WCOREDUMP(waiter) ?"" :"no ");
442 if (swap_uids() < OK)
443 err(ERROR_EXIT, "swapping uids");
444 if (stat(Filename, &statbuf) < 0) {
448 if (statbuf.st_dev != fsbuf.st_dev || statbuf.st_ino != fsbuf.st_ino)
449 errx(ERROR_EXIT, "temp file must be edited in place");
450 if (MD5File(Filename, new_md5) == NULL) {
454 if (swap_uids_back() < OK)
455 err(ERROR_EXIT, "swapping uids back");
456 if (strcmp(orig_md5, new_md5) == 0 && !syntax_error) {
457 warnx("no changes made to crontab");
460 warnx("installing new crontab");
461 switch (replace_cmd()) {
462 case 0: /* Success */
464 case -1: /* Syntax error */
466 printf("Do you want to retry the same edit? ");
469 (void) fgets(q, sizeof q, stdin);
470 switch (islower(q[0]) ? q[0] : tolower(q[0])) {
477 fprintf(stderr, "Enter Y or N\n");
481 case -2: /* Install error */
483 warnx("edits left in %s", Filename);
486 warnx("panic: bad switch() in replace_cmd()");
492 log_it(RealUser, Pid, "END EDIT", User);
496 /* returns 0 on success
498 * -2 on install error
502 char n[MAX_FNAME], envstr[MAX_ENVSTR], tn[MAX_FNAME];
506 time_t now = time(NULL);
507 char **envp = env_init();
510 warnx("cannot allocate memory");
514 (void) snprintf(n, sizeof(n), "tmp.%d", Pid);
515 (void) snprintf(tn, sizeof(tn), CRON_TAB(n));
517 if (!(tmp = fopen(tn, "w+"))) {
522 /* write a signature at the top of the file.
524 * VERY IMPORTANT: make sure NHEADER_LINES agrees with this code.
526 fprintf(tmp, "# DO NOT EDIT THIS FILE - edit the master and reinstall.\n");
527 fprintf(tmp, "# (%s installed on %-24.24s)\n", Filename, ctime(&now));
528 fprintf(tmp, "# (Cron version -- %s)\n", rcsid);
530 /* copy the crontab to the tmp
534 while (EOF != (ch = get_char(NewCrontab)))
536 ftruncate(fileno(tmp), ftello(tmp));
537 fflush(tmp); rewind(tmp);
540 warnx("error while writing new crontab to %s", tn);
541 fclose(tmp); unlink(tn);
545 /* check the syntax of the file being installed.
548 /* BUG: was reporting errors after the EOF if there were any errors
549 * in the file proper -- kludged it by stopping after first error.
552 Set_LineNum(1 - NHEADER_LINES)
553 CheckErrorCount = 0; eof = FALSE;
554 while (!CheckErrorCount && !eof) {
555 switch (load_env(envstr, tmp)) {
560 e = load_entry(tmp, check_error, pw, envp);
569 if (CheckErrorCount != 0) {
570 warnx("errors in crontab file, can't install");
571 fclose(tmp); unlink(tn);
576 if (fchown(fileno(tmp), ROOT_UID, -1) < OK)
578 if (chown(tn, ROOT_UID, -1) < OK)
582 fclose(tmp); unlink(tn);
587 if (fchmod(fileno(tmp), 0600) < OK)
589 if (chmod(tn, 0600) < OK)
593 fclose(tmp); unlink(tn);
597 if (fclose(tmp) == EOF) {
603 (void) snprintf(n, sizeof(n), CRON_TAB(User));
605 warn("error renaming %s to %s", tn, n);
610 log_it(RealUser, Pid, "REPLACE", User);
613 * Creating the 'tn' temp file has already updated the
614 * modification time of the spool directory. Sleep for a
615 * second to ensure that poke_daemon() sets a later
616 * modification time. Otherwise, this can race with the cron
617 * daemon scanning for updated crontabs.
630 struct timeval tvs[2];
632 (void)gettimeofday(&tvs[0], NULL);
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*/