(chicken string)
(chicken pathname)
(chicken file)
+ (chicken time)
(chicken time posix)
+ (chicken process)
(chicken process-context)
+ (chicken process-context posix)
(chicken condition)
srfi-1 srfi-13 matchable)
(define-record config
- host port spool-dir)
+ host port spool-dir user group)
(define-record message to from text helo)
(define (make-empty-message) (make-message "" "" "" ""))
;;; Server initialization
;;
+(define (drop-privs config)
+ (let ((uid (config-user config))
+ (gid (config-group config)))
+ (if (not (null? gid)) ; Group first, since only root can switch groups.
+ (set! (current-group-id) gid))
+ (if (not (null? uid))
+ (set! (current-user-id) uid))))
+
(define (run-server config)
(set-buffering-mode! (current-output-port) #:line)
(let ((listener (tcp-listen (config-port config) 10 "::")))
" listening on port " (config-port config) " ...")
(print "(Host name: " (config-host config)
", Spool dir: " (config-spool-dir config) ")")
+ (drop-privs config)
(server-loop listener config)))
(message-text-set! msg text)
(text-loop (smtp 'get-line)
(conc text text-line "\n"))))
- (deliver-message msg config)
+ (process-message msg config)
(smtp 'ok)
(loop (make-empty-message)
(smtp 'get-line)))
(right-idx (substring-index ">" addr)))
(substring addr (+ left-idx 1) right-idx)))
-(define (deliver-message msg config)
+(define (deliver-message-mbox msg dest-file)
+ (print "Delivering to mbox " dest-file)
+ (with-output-to-file dest-file
+ (lambda ()
+ (print "\nFrom " (remove-angle-brackets (message-from msg)))
+ (print (message-text msg)))
+ #:append))
+
+(define (deliver-message-maildir msg dest-dir)
+ (print "Delivering to maildir " dest-dir)
+ (with-output-to-file (conc dest-dir "/" (current-seconds))
+ (lambda ()
+ (print (message-text msg)))))
+
+(define (process-message msg config)
(let ((dest (assoc (message-to msg) (get-to-addresses config))))
(if dest
- (begin
- (with-output-to-file (cdr dest)
- (lambda ()
- (print "\nFrom " (remove-angle-brackets (message-from msg)))
- (print (message-text msg)))
- #:append)
+ (let ((dest-file (cdr dest)))
+ (if (directory-exists? dest-file)
+ (deliver-message-maildir msg dest-file)
+ (deliver-message-mbox msg dest-file))
(print "Message DELIVERED:"))
(print "Message REJECTED:"))
(print " * From: " (message-from msg))
;;
(define (print-usage progname)
- (print "Usage: " progname " hostname [port [spooldir]]"))
+ (print "Usage:\n"
+ progname " -h/--help\n"
+ progname " [-u/--user UID] [-g/--group GID] hostname [[port [spooldir]]\n"
+ "\n"
+ "The -u and -g options can be used to set the UID and GID of the process\n"
+ "following the creation of the TCP port listener (which often requires root)."))
(define (main)
(let ((progname (pathname-file (car (argv))))
- (args (cdr (argv)))
- (config (make-config "" 25 "/var/spool/mail")))
- (if (null? args)
+ (config (make-config "" 25 "/var/spool/mail" '() '())))
+ (if (null? (cdr (argv)))
(print-usage progname)
- (begin
- (config-host-set! config (car args))
- (unless (null? (cdr args))
- (config-port-set! config (string->number (cadr args)))
- (unless (null? (cddr args))
- (config-spool-dir-set! (caddr args))))
- (run-server config)))))
+ (let loop ((args (cdr (argv))))
+ (let ((this-arg (car args))
+ (rest-args (cdr args)))
+ (if (string-prefix? "-" this-arg)
+ (cond
+ ((or (equal? this-arg "-u")
+ (equal? this-arg "--user"))
+ (config-user-set! config (string->number (car rest-args)))
+ (loop (cdr rest-args)))
+ ((or (equal? this-arg "-g")
+ (equal? this-arg "--group"))
+ (config-group-set! config (string->number (car rest-args)))
+ (loop (cdr rest-args)))
+ ((or (equal? this-arg "-h")
+ (equal? this-arg "--help"))
+ (print-usage progname))
+ (else
+ (print "Unknown option " this-arg "\n")
+ (print-usage progname)))
+ (begin
+ (config-host-set! config this-arg)
+ (unless (null? rest-args)
+ (config-port-set! config (string->number (car rest-args)))
+ (unless (null? (cdr rest-args))
+ (config-spool-dir-set! (cadr rest-args))))
+ (run-server config))))))))
(main)