(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)))
(line-orig (smtp 'get-line)))
(if (string? line-orig)
(let ((line (string-downcase line-orig)))
+ (print "got " line)
(cond
((string-prefix? "helo" line)
(message-helo-set! msg (string-drop line (string-length "helo")))
- (print "got " line)
(smtp 'ok)
(loop msg (smtp 'get-line)))
((string-prefix? "mail from:" line)
- (print "got " line)
(message-from-set! msg (string-drop line (string-length "mail from:")))
(smtp 'ok)
(loop msg (smtp 'get-line)))
((string-prefix? "rcpt to:" line)
- (print "got " line)
(message-to-set! msg (string-drop line (string-length "rcpt to:")))
(smtp 'ok)
(loop msg (smtp 'get-line)))
((string-prefix? "data" line)
- (print "got " line)
(smtp 'intermediate)
(let text-loop ((text-line (smtp 'get-line))
(text ""))
- (print "Received '" text-line "'")
(if (string=? "." text-line)
(message-text-set! msg text)
(text-loop (smtp 'get-line)
- (conc text text-line))))
- (deliver-message msg config)
+ (conc text text-line "\n"))))
+ (process-message msg config)
(smtp 'ok)
(loop (make-empty-message)
(smtp 'get-line)))
(loop msg (smtp 'get-line)))
(else
(smtp 'not-implemented)
- (print "got " line)
(loop msg (smtp 'get-line)))))
'done)))
;;; Message delivery
;;
-
-(define (deliver-message msg config)
- (print "Message delivered:")
- (print " * From: " (message-from msg))
- (print " * To: " (message-to msg))
- (print " * Text: " (message-text msg)))
+
+(define (get-to-addresses config)
+ (map (lambda (p) (cons
+ (conc "<" (car p) "@" (config-host config) ">")
+ (cdr p)))
+ (map (lambda (file) (cons (pathname-file file) file))
+ (glob (conc (config-spool-dir config) "/*")))))
+
+(define (remove-angle-brackets addr)
+ (let ((left-idx (substring-index "<" addr))
+ (right-idx (substring-index ">" addr)))
+ (substring addr (+ left-idx 1) right-idx)))
+
+(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
+ (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))
+ (print " * To: " (message-to msg))))
;;; Command line argument parsing
;;
(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)
The Lambda Lab / projects / lambdamail.git / blobdiff