SF.net SVN: tmda: [2177] trunk/tmda/bin/tmda-ofmipd

Revision: 2177
          http://svn.sourceforge.net/tmda/?rev=2177&view=rev
Author:   srwarren
Date:     2007-03-14 20:09:24 -0700 (Wed, 14 Mar 2007)

Log Message:
-----------
tmda-ofmipd: A *much* simpler way of making handle_connect work.

Since we implement our own version of TLSAsyncDispatcherMixIn, we can make it call handle_connect directly on the object it should be called on. This removes the need to insert an extra class into the inheritance hierarchy just to hook handle_connect.

This change has been proposed to the tlslite developer, and hopefully will make it into some future release of tlslite.

Modified Paths:
--------------
    trunk/tmda/bin/tmda-ofmipd

Modified: trunk/tmda/bin/tmda-ofmipd
===================================================================
--- trunk/tmda/bin/tmda-ofmipd	2007-03-14 04:29:10 UTC (rev 2176)
+++ trunk/tmda/bin/tmda-ofmipd	2007-03-15 03:09:24 UTC (rev 2177)
@@ -59,48 +59,7 @@
     def flush(self): pass
 
 
-# Integration helper class for tlslite.
-#
-# tlslite's SSL handshake function is not synchronous; it may return prior
-# to handshake completion. In this case, we cannot perform application level
-# reads/writes to the socket, because doing so would corrupt the handshake
-# process.
-#
-# However, the very first thing an SMTP server wants to after a new connection
-# is established is to send the server signon greeting.
-#
-# So, we must wait for the handshake to complete. tlslite will notify us when
-# this occurs by calling the handle_connect function. However, note that
-# this function is called on the "sibling class" part of the object, not the
-# SMTPSession object. This forces us to sub-class async_chat so that we can
-# hook this call into the sibling class.
-#
-# tlslite calls the sibling class directly because asyncore/asynchat are
-# designed to call handle_connect on "self". Typically, the child class
-# (SMTPSession in our case) will implement this function. When tlslite is in
-# use, handle_connect is implemented by the tlslite mixin, which forwards the
-# evenr to the tlslite internals. To avoid infinite recursion, tlslite must
-# call handle_connect directly on the sibling class, not "self".
-#
-# Also note that when initializing an asyncore/async_chat sub-class with an
-# existing connected socket, like tmda-ofmipd does, asyncore/async_chat don't
-# call handle_connect. For this reason, we force this call ourselves at the
-# end of SMTPSession.__init__ (when not in SSL mode) in order to re-use the
-# same mechanism/function to send the server signon.
-
-class SMTPSessionSignon(asynchat.async_chat):
-    def __init__(self, conn):
-        asynchat.async_chat.__init__(self, conn)
-        self._sent_signon = False
-
-    def handle_connect(self):
-        self.init_dynamic_state() # calls sub-class
-        if not self._sent_signon:
-            self._sent_signon = True
-            self.push('220 %s ESMTP tmda-ofmipd' % FQDN)
-
-
-class SMTPSession(SMTPSessionSignon):
+class SMTPSession(asynchat.async_chat):
     COMMAND = 0
     DATA = 1
     AUTH = 2
@@ -111,9 +70,9 @@
         # Base class __init__ calls
 
         if opts.ssl or opts.tls:
-            TMDATLSAsyncDispatcherMixIn.__init__(self, conn, SMTPSessionSignon)
+            TMDATLSAsyncDispatcherMixIn.__init__(self, conn, asynchat.async_chat)
             self.tlsConnection.ignoreAbruptClose = True
-        SMTPSessionSignon.__init__(self, conn)
+        asynchat.async_chat.__init__(self, conn)
 
         # Save our own __init__ parameters
 
@@ -184,6 +143,8 @@
         # VPopMail's reverse IP domain mapping.
         os.environ['TCPLOCALIP'] = self._localip
 
+        self._sent_signon = False
+
         # SSL/TLS/STARTTLS
         self.__can_starttls = opts.tls
 
@@ -217,6 +178,12 @@
         self.setServerHandshakeOp(certChain=opts.ssl_cert_value,
                                   privateKey=opts.ssl_key_value)
 
+    def handle_connect(self):
+        self.init_dynamic_state()
+        if not self._sent_signon:
+            self._sent_signon = True
+            self.push('220 %s ESMTP tmda-ofmipd' % FQDN)
+
     # Overrides base class for convenience
     def push(self, msg):
         asynchat.async_chat.push(self, msg + '\r\n')
@@ -1324,7 +1291,7 @@
         def outConnectEvent(self):
             if not self._active:
                 raise "Internal state confusion"
-            self.siblingClass.handle_connect(self)
+            self.handle_connect()
 
         def outCloseEvent(self):
             if not self._active:


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