(chicken process-context)
(chicken process-context posix)
(chicken condition)
+ (chicken sort)
srfi-1 srfi-13 matchable base64)
-(define lambdamail-version "LambdaMail v0.0.1")
+(define lambdamail-version "LambdaMail v1.0.0")
(define-record config host port spool-dir user group)
(define-record message to from text user password)
(define (make-empty-message) (make-message "" "" "" "" ""))
+(define (time-stamp)
+ (time->string (seconds->local-time) "%d %b %Y %T %z"))
+
;;; Server initialization
;;
(define (receive-messages listener config)
(let ((messages '()))
+ (print "*** Waiting for incoming mail")
(let-values (((in-port out-port) (tcp-accept listener)))
(let-values (((local-ip remote-ip) (tcp-addresses in-port)))
- (print "Accepted connection from " remote-ip " on " (seconds->string)))
+ (print "Accepted connection from " remote-ip " on " (time-stamp)))
(condition-case
(set! messages (process-smtp (make-smtp-session in-port out-port config) config))
(o (exn)
(define (make-smtp-session in-port out-port config)
(let ((user "")
- (password ""))
+ (password "")
+ (helo ""))
(lambda command
(match command
(('get-line) (read-line in-port))
(('send strings ...) (write-line (conc (apply conc strings) "\r") out-port))
(('set-user! u) (set! user u))
(('set-password! p) (set! password p))
+ (('set-helo! h) (set! helo h))
(('user) user)
- (('password) password)))))
+ (('password) password)
+ (('helo) helo)))))
(define (smtp-command? cmd-string input-string)
(string-prefix? cmd-string (string-downcase input-string)))
""))
(define (process-smtp smtp-session config)
- (smtp-session 'send "220 " (config-host config) lambdamail-version)
+ (smtp-session 'send "220 " (config-host config) " " lambdamail-version)
(let loop ((msg (make-empty-message))
(received-messages '()))
(let ((line (smtp-session 'get-line)))
(print "got " line)
(cond
((smtp-command? "helo" line)
+ (smtp-session 'set-helo! (smtp-command-args "helo" line))
(smtp-session 'send "250 ok")
(loop msg received-messages))
((smtp-command? "ehlo" line)
+ (smtp-session 'set-helo! (smtp-command-args "helo" line))
(smtp-session 'send
"250-" (config-host config)
" Hello " (smtp-command-args "ehlo" line))
(loop msg received-messages))
((smtp-command? "data" line)
(smtp-session 'send "354 intermediate")
- (let text-loop ((text ""))
+ (let text-loop ((text (conc "Received: from " (smtp-session 'helo) "\n"
+ " by " (config-host config) "\n"
+ " for " (message-from msg)
+ "; " (time-stamp) "\n")))
(let ((text-line (smtp-session 'get-line)))
(if (string=? "." text-line)
(message-text-set! msg text)
;;
(define (deliver-messages config messages)
- (print "Attempting delivery of " (length messages) " mail items.")
+ (print "**** Attempting delivery of " (length messages) " mail items.")
(filter (lambda (msg) (not (deliver-message msg config)))
messages))
(define (deliver-message msg config)
+ (print "From: " (message-from msg))
+ (print "To: " (message-to msg))
(condition-case
- (begin
- (let* ((local-addresses (get-local-addresses config))
- (dest (assoc (message-to msg) local-addresses))
- (orig (assoc (message-from msg) local-addresses)))
- (cond
- (dest
- (let ((dest-dir (cadr dest)))
- (deliver-message-local msg dest-file))
- (print "Message DELIVERED (local):"))
- (orig
- (let ((password (caddr orig)))
- (if (and
- (string=? (conc "<" (message-user msg) "@" (config-host config) ">")
- (message-from msg))
- password
- (string=? (message-password msg) password))
- (begin
- (deliver-message-remote msg config)
- (print "Message DELIVERED (remote):"))
- (print "Message DELIVERY REJECTED (auth failure):"))))
- (else
- (print "Message DELIVERY REJECTED (relay forbidden):"))))
- (print " * From: " (message-from msg))
- (print " * To: " (message-to msg))
- #t)
+ (let* ((local-addresses (get-local-addresses config))
+ (dest (assoc (message-to msg) local-addresses))
+ (orig (assoc (message-from msg) local-addresses)))
+ (cond
+ (dest
+ (let ((dest-dir (cadr dest)))
+ (deliver-message-local msg dest-dir)))
+ (orig
+ (let ((password (caddr orig)))
+ (if (and (string=? (conc "<" (message-user msg) "@" (config-host config) ">")
+ (message-from msg))
+ password
+ (string=? (message-password msg) password))
+ (deliver-message-remote msg config)
+ (begin
+ (print "* REMOTE DELIVERY NOT ALLOWED (auth failure)")
+ #t))))
+ (else
+ (print "* REMOTE DELIVERY REJECTED (relay forbidden)")
+ #t)))
(o (exn)
- (print "Message delivery failed.")
- (print-error-message o))))
+ (print "* DELIVERY FAILED")
+ (print-error-message o)
+ #t)))
+
;; Local delivery
(define (deliver-message-local msg dest-dir)
(with-output-to-file (conc dest-dir "/" (current-seconds))
(lambda ()
- (print (message-text msg)))))
+ (print (message-text msg))))
+ (print "* MESSAGE DELIVERED (local)")
+ #t)
;; Remote delivery
-(define (get-host-from-email email-string)
+(define (get-domain-from-email email-string)
(car (string-split (cadr (string-split email-string "@")) ">")))
+;; This is a hack - there's no built-in interface to res_query()
+;; in chicken, so we have to resort to a system call to dig...
+(define (get-mail-server-for-domain domain)
+ (let* ((mx-lines (let-values (((in out id) (process (conc "dig " domain " mx +short"))))
+ (with-input-from-port in read-lines)))
+ (mx-entries (map (lambda (l)
+ (let ((s (string-split l)))
+ (list (string->number (car s))
+ (string-drop-right (cadr s) 1)))) ; remove trailing "."
+ mx-lines))
+ (sorted-mx-entries (sort mx-entries (lambda (e f) (< (car e) (car f))))))
+ (if (null? sorted-mx-entries)
+ domain ; fall-back to email address domain if no mx entries
+ (cadar sorted-mx-entries)))) ; otherwise pick the highest priority server
+
(define (deliver-message-remote msg config)
- (let ((host (get-host-from-email (message-to msg))))
- (print "Attempting delivery to host " host)
- (let-values (((tcp-in tcp-out) (tcp-connect host 25)))
+ (let* ((domain (get-domain-from-email (message-to msg)))
+ (mail-server (get-mail-server-for-domain domain)))
+ (print "Attempting delivery to " mail-server)
+ (let-values (((tcp-in tcp-out) (tcp-connect mail-server 25)))
(let ((smtp-session (make-outgoing-smtp-session tcp-in tcp-out)))
(let ((result (and
(smtp-session 'expect "220")
(smtp-session 'send "data")
(smtp-session 'expect "354")
(smtp-session 'send (message-text msg))
+ (smtp-session 'send ".")
(smtp-session 'expect "250")
(smtp-session 'send "quit"))))
(close-input-port tcp-in)
(close-output-port tcp-out)
+ (print "Connection closed.")
+ (if result
+ (print "* MESSAGE DELIVERED (remote)")
+ (print "* REMOTE DELIVERY FAILED (unexpected server response)"))
result)))))
-(define ((make-outgoing-smtp-session tcp-in tcp-out) command)
+(define ((make-outgoing-smtp-session tcp-in tcp-out) . command)
(match command
(('expect code)
- (string-prefix? "220" (read-line tcp-in)))
+ (let ((result (read-line tcp-in)))
+ (print "Expecting " code " got " result)
+ (string-prefix? code result)))
(('send strings ...)
- (write-string (string-translate (conc (apply conc strings) "\n") "\n" "\r\n")
- out-port))))
+ (print "Sending " (if (> (string-length (car strings)) 30)
+ (string-take (car strings) 30)
+ (car strings)))
+ (let ((processed-string
+ (string-translate* (conc (apply conc strings) "\n")
+ '(("\n" . "\r\n")))))
+ (write-string processed-string #f tcp-out)))))
+
;;; Command line argument parsing
;;
The Lambda Lab / projects / lambdamail.git / blobdiff