From: Tim Vaughan <tgvaughan@gmail.com>
Date: Wed, 4 Sep 2019 09:40:47 +0000 (+0200)
Subject: Cleanup.
X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=commitdiff_plain;h=1d04df7655dee7ebdd292a65ad399610b532e111;p=lambdamail.git

Cleanup.
---

diff --git a/lambdamail.scm b/lambdamail.scm
index 3f3594e..fe9519e 100644
--- a/lambdamail.scm
+++ b/lambdamail.scm
@@ -16,13 +16,11 @@
         (chicken condition)
         srfi-1 srfi-13 matchable base64)
 
-(define lambdamail-version "0.0.1")
+(define lambdamail-version "LambdaMail v0.0.1")
 
 (define-record config host port spool-dir user group)
-(define-record message to from text helo user password)
-(define (make-empty-message) (make-message "" "" "" "" "" ""))
-
-(define outbound-mail-queue '())
+(define-record message to from text user password)
+(define (make-empty-message) (make-message "" "" "" "" ""))
 
 
 ;;; Server initialization
@@ -39,121 +37,125 @@
 (define (run-server config)
   (set-buffering-mode! (current-output-port) #:line)
   (let ((listener (tcp-listen (config-port config) 10 "::")))
-    (print "LambdaMail v" lambdamail-version
+    (print lambdamail-version
            " 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)))
+    (server-loop listener config '())))
 
 
 ;;; Main server loop
 ;;
 
-(define (server-loop listener config)
-  (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)))
-    (condition-case
-        (let ((smtp-session (make-smtp-session in-port out-port config)))
-          (smtp-session 'greet)
-          (process-smtp smtp-session config))
-      (o (exn)
-         (print-error-message o)))
-    (print "Terminating connection.")
-    (close-input-port in-port)
-    (close-output-port out-port))
-  (print "Attempting delivery of " (length outbound-mail-queue) " mail items.")
-  (set! outbound-mail-queue
-    (filter (lambda (msg) (not (deliver-message msg config)))
-            outbound-mail-queue))
-  (server-loop listener config))
-
-;;; SMTP processing loop
+(define (server-loop listener config undelivered-messages)
+  (let* ((messages (append (receive-messages listener config) undelivered-messages)))
+    (server-loop listener config (deliver-messages config messages))))
+
+
+;;; Receiving messages
 ;;
 
+(define (receive-messages listener config)
+  (let ((messages '()))
+    (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)))
+      (condition-case
+          (set! messages (process-smtp (make-smtp-session in-port out-port config) config))
+        (o (exn)
+           (print-error-message o)))
+      (print "Terminating connection.")
+      (close-input-port in-port)
+      (close-output-port out-port))
+    messages))
+
 (define (make-smtp-session in-port out-port config)
-  (let ((smtp-say (lambda args (write-line (conc (apply conc args) "\r") out-port)))
-        (user "")
+  (let ((user "")
         (password ""))
     (lambda msg
       (match msg
         (('get-line) (read-line in-port))
+        (('send-line strings ...) (write-line (conc (apply conc strings) "\r") out-port))
         (('set-user! u) (set! user u))
         (('set-password! p) (set! password p))
         (('user) user)
-        (('password) password)
-        (('auth-success) (smtp-say "235 Authentication successful"))
-        (('greet) (smtp-say "220 " (config-host config)
-                            " LambdaMail v" lambdamail-version))
-        (('ok) (smtp-say "250 ok"))
-        (('ehlo host)
-         (smtp-say "250-" (config-host config) " Hello " host)
-         (smtp-say "250 AUTH PLAIN"))
-        (('intermediate) (smtp-say "354 intermediate"))
-        (('close) (smtp-say "221 closing transmission channel"))
-        (('not-implemented) (smtp-say "502 command not implemented"))))))
+        (('password) password)))))
+
+(define (smtp-command? cmd-string input-string)
+  (string-prefix? cmd-string (string-downcase input-string)))
+
+(define (smtp-command-args cmd-string input-string)
+  (if (> (string-length input-string) (string-length cmd-string))
+      (string-trim (string-drop input-string (string-length cmd-string)))
+      ""))
 
 (define (process-smtp smtp-session config)
-  (let loop ((msg (make-empty-message)))
-    (let ((line-orig (smtp-session 'get-line)))
-      (if (string? line-orig)
-          (let ((line (string-downcase line-orig)))
-            (print "got " line-orig)
-            (cond
-             ((string-prefix? "helo" line)
-              (message-helo-set! msg (string-drop line (string-length "helo")))
-              (smtp-session 'ok)
-              (loop msg))
-             ((string-prefix? "ehlo" line)
-              (smtp-session 'ehlo (string-drop line (+ 1 (string-length "ehlo"))))
-              (loop msg))
-             ((string-prefix? "auth plain" line)
-              (let* ((auth-string (string-drop line-orig (+ 1 (string-length "auth plain"))))
-                     (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 'auth-success)
-                (loop msg)))
-             ((string-prefix? "mail from:" line)
-              (message-from-set! msg (string-drop line (string-length "mail from:")))
-              (smtp-session 'ok)
-              (loop msg))
-             ((string-prefix? "rcpt to:" line)
-              (message-to-set! msg (string-drop line (string-length "rcpt to:")))
-              (smtp-session 'ok)
-              (loop msg))
-             ((string-prefix? "data" line)
-              (smtp-session 'intermediate)
-              (let text-loop ((text-line (smtp-session 'get-line))
-                              (text ""))
-                (if (string=? "." text-line)
-                    (message-text-set! msg text)
-                    (text-loop (smtp-session 'get-line)
-                               (conc text text-line "\n"))))
-              (message-user-set! msg (smtp-session 'user))
-              (message-password-set! msg (smtp-session 'password))
-              (set! outbound-mail-queue (cons msg outbound-mail-queue))
-              (smtp-session 'ok)
-              (loop (make-empty-message)))
-             ((string-prefix? "quit" line)
-              (smtp-session 'close)
-              'done)
-             ((string=? "" line)
-              (loop msg))
-             (else
-              (smtp-session 'not-implemented)
-              (loop msg))))
-          'done))))
-
-
-;;; Message delivery
+  (smtp-session 'send-line "220 " (config-host config) lambdamail-version)
+  (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 'send-line "250 ok")
+          (loop msg received-messages))
+         ((smtp-command? "ehlo" line)
+          (smtp-session 'send-line
+                        "250-" (config-host config)
+                        " Hello " (smtp-command-args "ehlo" line))
+          (smtp-session 'send-line "250 AUTH PLAIN")
+          ;; (smtp-session 'send-line "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-line "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-line "250 ok")
+          (loop msg received-messages))
+         ((smtp-command? "rcpt to:" line)
+          (message-to-set! msg (smtp-command-args "rcpt to:" line))
+          (smtp-session 'send-line "250 ok")
+          (loop msg received-messages))
+         ((smtp-command? "data" line)
+          (smtp-session 'send-line "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")))))
+          (message-user-set! msg (smtp-session 'user))
+          (message-password-set! msg (smtp-session 'password))
+          (smtp-session 'send-line "250 ok")
+          (loop (make-empty-message) (cons msg received-messages)))
+         ((smtp-command? "quit" line)
+          (smtp-session 'send-line "221 closing transmission channel")
+          received-messages)
+         ((string=? "" (string-trim line))
+          (loop msg received-messages))
+         (else
+          (smtp-session 'send-line "502 command not implemented")
+          (loop msg received-messages)))))))
+
+
+;;; Delivering messages
 ;;
 
+(define (deliver-messages config messages)
+  (print "Attempting delivery of " (length messages) " mail items.")
+  (filter (lambda (msg) (not (deliver-message msg config)))
+          messages))
+
 (define (get-to-addresses config)
   (map (lambda (p) (cons
                     (conc "<" (car p) "@" (config-host config) ">")