(chicken sort)
srfi-1 srfi-13 matchable base64)
-(define lambdamail-version "LambdaMail v1.0.0")
+(define lambdamail-version "LambdaMail v1.5.0")
(define-record config host port spool-dir user group)
(define-record message to from text user password)
-(define (make-empty-message) (make-message "" "" "" "" ""))
+(define (make-empty-message) (make-message '() "" "" "" ""))
(define (time-stamp)
(time->string (seconds->local-time) "%d %b %Y %T %z"))
messages))
(define (make-smtp-session in-port out-port config)
- (let ((user "")
- (password "")
- (helo ""))
+ (let ((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)
(('helo) helo)))))
(define (smtp-command? cmd-string input-string)
(let loop ((msg (make-empty-message))
(received-messages '()))
(let ((line (smtp-session 'get-line)))
- (when (string? 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))
- (smtp-session 'send "250 AUTH PLAIN")
- ;; (smtp-session 'send "250 STARTTLS")
- (loop msg received-messages))
- ((smtp-command? "auth plain" line)
- (let* ((auth-string (smtp-command-args "auth plain" line))
- (auth-decoded (base64-decode auth-string))
- (auth-list (string-split auth-decoded "\x00"))
- (user (car auth-list))
- (password (cadr auth-list)))
- (smtp-session 'set-user! user)
- (smtp-session 'set-password! password)
- (print "Attempted login, user: " user ", password: " password)
- (smtp-session 'send "235 authentication successful")
- (loop msg received-messages)))
- ((smtp-command? "mail from:" line)
- (message-from-set! msg (smtp-command-args "mail from:" line))
- (smtp-session 'send "250 ok")
- (loop msg received-messages))
- ((smtp-command? "rcpt to:" line)
- (message-to-set! msg (smtp-command-args "rcpt to:" line))
- (smtp-session 'send "250 ok")
- (loop msg received-messages))
- ((smtp-command? "data" line)
- (smtp-session 'send "354 intermediate")
- (let text-loop ((text (conc "Received: from " (smtp-session 'helo) "\n"
- "\tby " (config-host config) "\n"
- "\tfor " (message-to msg) ";\n"
- "\t" (time-stamp) "\n")))
- (let ((text-line (smtp-session 'get-line)))
- (if (string=? "." text-line)
- (message-text-set! msg text)
- (text-loop (conc text text-line "\n")))))
- (message-user-set! msg (smtp-session 'user))
- (message-password-set! msg (smtp-session 'password))
- (smtp-session 'send "250 ok")
- (loop (make-empty-message) (cons msg received-messages)))
- ((smtp-command? "quit" line)
- (smtp-session 'send "221 closing transmission channel")
- received-messages)
- ((string=? "" (string-trim line))
- (loop msg received-messages))
- (else
- (smtp-session 'send "502 command not implemented")
- (loop msg received-messages))))))
- '())
+ (print "got " line)
+ (if (not (string? line))
+ '() ; Don't keep anything on unexpected termination.
+ (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))
+ (smtp-session 'send "250 AUTH PLAIN")
+ ;; (smtp-session 'send "250 STARTTLS")
+ (loop msg received-messages))
+ ((smtp-command? "auth plain" line)
+ (let* ((auth-string (smtp-command-args "auth plain" line))
+ (auth-decoded (base64-decode auth-string))
+ (auth-list (string-split auth-decoded "\x00"))
+ (user (car auth-list))
+ (password (cadr auth-list)))
+ (message-user-set! msg user)
+ (message-password-set! msg password)
+ (print "Attempted login, user: " user ", password: " password)
+ (smtp-session 'send "235 authentication successful")
+ (loop msg received-messages)))
+ ((smtp-command? "mail from:" line)
+ (message-from-set! msg (smtp-command-args "mail from:" line))
+ (smtp-session 'send "250 ok")
+ (loop msg received-messages))
+ ((smtp-command? "rcpt to:" line)
+ (message-to-set! msg (cons (smtp-command-args "rcpt to:" line)
+ (message-to msg)))
+ (if (message-valid? msg config)
+ (smtp-session 'send "250 ok")
+ (smtp-session 'send "551 relay forbidden"))
+ (loop msg received-messages))
+ ((smtp-command? "data" line)
+ (smtp-session 'send "354 intermediate")
+ (let text-loop ((text '()))
+ (let ((text-line (smtp-session 'get-line)))
+ (if (string=? "." text-line)
+ (message-text-set! msg text)
+ (text-loop (conc text text-line "\n")))))
+ (smtp-session 'send "250 ok")
+ (loop (make-empty-message) (append (get-single-recipient-messages msg smtp-session)
+ received-messages)))
+ ((smtp-command? "quit" line)
+ (smtp-session 'send "221 closing transmission channel")
+ received-messages)
+ ((string=? "" (string-trim line))
+ (loop msg received-messages))
+ (else
+ (smtp-session 'send "502 command not implemented")
+ (loop msg received-messages)))))))
+
+(define (get-single-recipient-messages smtp-session msg)
+ (map
+ (lambda (to)
+ (make-message to (message-from msg)
+ (conc "Received: from " (smtp-session 'helo) "\n"
+ "\tby " (config-host config) "\n"
+ "\tfor " to ";\n"
+ "\t" (time-stamp) "\n"
+ (message-text msg))
+ (message-user msg)
+ (message-password msg)))
+ (message-to msg)))
+
+
+;;; Message stamping and validation
+;;
+
+(define (get-local-addresses config)
+ (map (lambda (p) (cons
+ (conc "<" (car p) "@" (config-host config) ">")
+ (cdr p)))
+ (map (lambda (file)
+ (list (pathname-file file) file
+ (let ((password-file (conc file ".auth")))
+ (if (file-exists? password-file)
+ (with-input-from-file password-file read-line)
+ #f))))
+ (filter directory-exists?
+ (glob (conc (config-spool-dir config) "/*"))))))
+
+(define (message-stamp msg config)
+ (let* ((local-addresses (get-local-addresses config))
+ (local-dest (assoc (message-to msg) local-addresses))
+ (local-src (assoc (message-from msg) local-addresses)))
+ (cond
+ (local-dest
+ (list #t 'local (cadr local-dest)))
+ (local-src
+ (let ((password (caddr local-src)))
+ (if (and (string=? (conc "<" (message-user msg) "@" (config-host config) ">")
+ (message-from msg))
+ password
+ (string=? (message-password msg) password))
+ (list #t 'remote)
+ (begin
+ (print "Provided password " (message-password msg))
+ (print "Host password " password)
+ (list #f 'remote)))))
+ (else
+ (list #f 'relay)))))
+
+(define (message-valid? msg config)
+ (let ((stamp (message-stamp msg config)))
+ (print "Stamp: " stamp)
+ (car stamp)))
;;; Sending/Delivering messages
(print "From: " (message-from msg))
(print "To: " (message-to msg))
(condition-case
- (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)))
+ (match (message-stamp msg config)
+ ((#t 'local dest-dir) (deliver-message-local msg dest-dir))
+ ((#t 'remote) (deliver-message-remote msg config))
+ ((#f 'remote)
+ (print "* REMOTE DELIVERY NOT ALLOWED (auth failure)")
+ #t)
+ (else
+ (print "* DELIVERY NOT ALLOWED (relay forbidden)")
+ #t))
(o (exn)
(print "* DELIVERY FAILED")
(print-error-message o)
#t)))
-
;; Local delivery
-(define (get-local-addresses config)
- (map (lambda (p) (cons
- (conc "<" (car p) "@" (config-host config) ">")
- (cdr p)))
- (map (lambda (file)
- (list (pathname-file file) file
- (let ((password-file (conc file ".auth")))
- (if (file-exists? password-file)
- (with-input-from-file password-file read-line)
- #f))))
- (filter directory-exists?
- (glob (conc (config-spool-dir config) "/*"))))))
-
(define (deliver-message-local msg dest-dir)
(with-output-to-file (conc dest-dir "/" (current-seconds))
(lambda ()
(smtp-session 'expect "354")
(smtp-session 'send (message-text msg))
(smtp-session 'send ".")
- (smtp-session 'expect "250")
+ (smtp-session 'expect "250" "5") ;Do not try again on rejects.
(smtp-session 'send "quit"))))
(close-input-port tcp-in)
(close-output-port tcp-out)
(print "* REMOTE DELIVERY FAILED (unexpected server response)"))
result)))))
+(define (or-list l)
+ (fold (lambda (a b) (or a b)) #f l))
+
(define ((make-outgoing-smtp-session tcp-in tcp-out) . command)
(match command
- (('expect code)
- (let ((result (read-line tcp-in)))
- (print "Expecting " code " got " result)
- (string-prefix? code result)))
+ (('expect codes ...)
+ (let loop ((result (read-line tcp-in)))
+ (if (and (> (string-length result) 3)
+ (eq? (string-ref result 3) #\-))
+ (loop (read-line tcp-in)) ;status continues on next line
+ (begin
+ (print "Expecting one of " codes " got " result)
+ (or-list (map (lambda (code)
+ (string-prefix? code result))
+ codes))))))
(('send strings ...)
(print "Sending " (if (> (string-length (car strings)) 30)
(string-take (car strings) 30)
(define (print-usage progname)
(print "Usage:\n"
progname " -h/--help\n"
+ progname " -v/--version\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 (print-version)
+ (print lambdamail-version))
+
(define (main)
(let ((progname (pathname-file (car (argv))))
(config (make-config "" 25 "/var/spool/mail" '() '())))
((or (equal? this-arg "-h")
(equal? this-arg "--help"))
(print-usage progname))
+ ((or (equal? this-arg "-v")
+ (equal? this-arg "--version"))
+ (print-version))
(else
(print "Unknown option " this-arg "\n")
(print-usage progname)))
;; (define (test)
;; (run-server (make-config "localhost" 2525 "spool" '() '())))
+
+;; (test)