diff options
Diffstat (limited to 'crontab.scm')
| -rw-r--r-- | crontab.scm | 138 |
1 files changed, 74 insertions, 64 deletions
diff --git a/crontab.scm b/crontab.scm index ff74947..30e5592 100644 --- a/crontab.scm +++ b/crontab.scm @@ -1,4 +1,4 @@ -;; Copyright (C) 2003 Dale Mellor +;; Copyright (C) 2003, 2014 Dale Mellor ;; ;; This file is part of GNU mcron. ;; @@ -27,14 +27,15 @@ ;; 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. -(define (hit-server 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")))) +(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"))))) @@ -42,89 +43,95 @@ ;; /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. -(define (in-access-file? 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) '()))) - - + (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. + ;; This program should have been installed SUID root. Here we get the + ;; passwd entry for the real user who is running this program. -(define crontab-real-user (passwd:name (getpw (getuid)))) + (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 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.")) + (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. -;; 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.")) -(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. -;; 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.")) -(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. + + ;; Iff the --user option is given, the crontab-user may be different + ;; from the real user. -(define crontab-user (option-ref options 'user crontab-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)) -;; So now we know which crontab file we will be manipulating. -(define 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)))))) -;; 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. -(define (get-yes-no 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). - -;; 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 + (cond ;; In the list personality, we simply open the crontab and copy it @@ -216,3 +223,6 @@ (else (mcron-error 15 "usage error: file name must be specified for replace."))) + + +)) ;; End of file-level let-scopes. |