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Diffstat (limited to 'src/mcron/crontab.scm')
| -rw-r--r-- | src/mcron/crontab.scm | 228 |
1 files changed, 0 insertions, 228 deletions
diff --git a/src/mcron/crontab.scm b/src/mcron/crontab.scm deleted file mode 100644 index 6be5c61..0000000 --- a/src/mcron/crontab.scm +++ /dev/null @@ -1,228 +0,0 @@ -;; Copyright (C) 2003, 2014 Dale Mellor -;; -;; This file is part of GNU mcron. -;; -;; GNU mcron is free software: you can redistribute it and/or modify it under -;; the terms of the GNU General Public License as published by the Free -;; Software Foundation, either version 3 of the License, or (at your option) -;; any later version. -;; -;; GNU mcron is distributed in the hope that it will be useful, but WITHOUT -;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or -;; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for -;; more details. -;; -;; You should have received a copy of the GNU General Public License along -;; with GNU mcron. If not, see <http://www.gnu.org/licenses/>. - - -;; Apart from the collecting of options and the handling of --help and --version -;; (which are done in the main.scm file), this file provides all the -;; functionality of the crontab personality. It is designed to be loaded and run -;; once, and then the calling program can exit and the crontab program will have -;; completed its function. - - - -;; Procedure to communicate with running cron daemon that a user has modified -;; his crontab. The user name is written to the /var/cron/socket UNIX socket. - -(let ((hit-server - (lambda (user-name) - (catch #t (lambda () - (let ((socket (socket AF_UNIX SOCK_STREAM 0))) - (connect socket AF_UNIX config-socket-file) - (display user-name socket) - (close socket))) - (lambda (key . args) - (display "Warning: a cron daemon is not running.\n"))))) - - - -;; Procedure to scan a file containing one user name per line (such as -;; /var/cron/allow and /var/cron/deny), and determine if the given name is in -;; there. The procedure returns #t, #f, or '() if the file does not exist. - - (in-access-file? - (lambda (file name) - (catch #t (lambda () - (with-input-from-file - file - (lambda () - (let loop ((input (read-line))) - (if (eof-object? input) - #f - (if (string=? input name) - #t - (loop (read-line)))))))) - (lambda (key . args) '())))) - - - - ;; This program should have been installed SUID root. Here we get the - ;; passwd entry for the real user who is running this program. - - (crontab-real-user (passwd:name (getpw (getuid))))) - - - - ;; If the real user is not allowed to use crontab due to the /var/cron/allow - ;; and/or /var/cron/deny files, bomb out now. - - (if (or (eq? (in-access-file? config-allow-file crontab-real-user) #f) - (eq? (in-access-file? config-deny-file crontab-real-user) #t)) - (mcron-error 6 "Access denied by system operator.")) - - - - ;; Check that no more than one of the mutually exclusive options are being - ;; used. - - (if (> (+ (if (option-ref options 'edit #f) 1 0) - (if (option-ref options 'list #f) 1 0) - (if (option-ref options 'remove #f) 1 0)) - 1) - (mcron-error 7 "Only one of options -e, -l or -r can be used.")) - - - - ;; Check that a non-root user is trying to read someone else's files. - - (if (and (not (eqv? (getuid) 0)) - (option-ref options 'user #f)) - (mcron-error 8 "Only root can use the -u option.")) - - - - (let ( - - - ;; Iff the --user option is given, the crontab-user may be different - ;; from the real user. - - (crontab-user (option-ref options 'user crontab-real-user)) - - - ;; So now we know which crontab file we will be manipulating. - - (crontab-file (string-append config-spool-dir "/" crontab-user)) - - - - ;; Display the prompt and wait for user to type his choice. Return #t if - ;; the answer begins with 'y' or 'Y', return #f if it begins with 'n' or - ;; 'N', otherwise ask again. - - (get-yes-no (lambda (prompt . re-prompt) - (if (not (null? re-prompt)) - (display "Please answer y or n.\n")) - (display (string-append prompt " ")) - (let ((r (read-line))) - (if (not (string-null? r)) - (case (string-ref r 0) - ((#\y #\Y) #t) - ((#\n #\N) #f) - (else (get-yes-no prompt #t))) - (get-yes-no prompt #t)))))) - - - - ;; There are four possible sub-personalities to the crontab personality: - ;; list, remove, edit and replace (when the user uses no options but - ;; supplies file names on the command line). - - (cond - - - ;; In the list personality, we simply open the crontab and copy it - ;; character-by-character to the standard output. If anything goes wrong, it - ;; can only mean that this user does not have a crontab file. - - ((option-ref options 'list #f) - (catch #t (lambda () - (with-input-from-file crontab-file (lambda () - (do ((input (read-char) (read-char))) - ((eof-object? input)) - (display input))))) - (lambda (key . args) - (display (string-append "No crontab for " - crontab-user - " exists.\n"))))) - - - ;; In the edit personality, we determine the name of a temporary file and an - ;; editor command, copy an existing crontab file (if it is there) to the - ;; temporary file, making sure the ownership is set so the real user can edit - ;; it; once the editor returns we try to read the file to check that it is - ;; parseable (but do nothing more with the configuration), and if it is okay - ;; (this program is still running!) we move the temporary file to the real - ;; crontab, wake the cron daemon up, and remove the temporary file. If the - ;; parse fails, we give user a choice of editing the file again or quitting - ;; the program and losing all changes made. - - ((option-ref options 'edit #f) - (let ((temp-file (string-append config-tmp-dir - "/crontab." - (number->string (getpid))))) - (catch #t (lambda () (copy-file crontab-file temp-file)) - (lambda (key . args) (with-output-to-file temp-file noop))) - (chown temp-file (getuid) (getgid)) - (let retry () - (system (string-append - (or (getenv "VISUAL") (getenv "EDITOR") "vi") - " " - temp-file)) - (catch 'mcron-error - (lambda () (read-vixie-file temp-file)) - (lambda (key exit-code . msg) - (apply mcron-error 0 msg) - (if (get-yes-no "Edit again?") - (retry) - (begin - (mcron-error 0 "Crontab not changed") - (primitive-exit 0)))))) - (copy-file temp-file crontab-file) - (delete-file temp-file) - (hit-server crontab-user))) - - - ;; In the remove personality we simply make an effort to delete the crontab and - ;; wake the daemon. No worries if this fails. - - ((option-ref options 'remove #f) - (catch #t (lambda () (delete-file crontab-file) - (hit-server crontab-user)) - noop)) - - - ;; !!!! This comment is wrong. - - ;; In the case of the replace personality we loop over all the arguments on the - ;; command line, and for each one parse the file to make sure it is parseable - ;; (but subsequently ignore the configuration), and all being well we copy it - ;; to the crontab location; we deal with the standard input in the same way but - ;; different. :-) In either case the server is woken so that it will read the - ;; newly installed crontab. - - ((not (null? (option-ref options '() '()))) - (let ((input-file (car (option-ref options '() '())))) - (catch-mcron-error - (if (string=? input-file "-") - (let ((input-string (stdin->string))) - (read-vixie-port (open-input-string input-string)) - (with-output-to-file crontab-file (lambda () - (display input-string)))) - (begin - (read-vixie-file input-file) - (copy-file input-file crontab-file)))) - (hit-server crontab-user))) - - - ;; The user is being silly. The message here is identical to the one Vixie cron - ;; used to put out, for total compatibility. - - (else (mcron-error 15 - "usage error: file name must be specified for replace."))) - - -)) ;; End of file-level let-scopes. |