Added timeout to smtplib (to SMTP and SMTP_SSL). Also created

the test_smtplib.py file, with a basic test and the timeout
ones. Docs are updated too.

Doc/lib/libsmtplib.tex

@@ -15,13 +15,16 @@ listener daemon.  For details of SMTP and ESMTP operation, consult
 (\citetitle{SMTP Service Extensions}).
 
 \begin{classdesc}{SMTP}{\optional{host\optional{, port\optional{,
-                        local_hostname}}}}
+                        local_hostname\optional{, timeout}}}}}
 A \class{SMTP} instance encapsulates an SMTP connection.  It has
 methods that support a full repertoire of SMTP and ESMTP
 operations. If the optional host and port parameters are given, the
 SMTP \method{connect()} method is called with those parameters during
 initialization.  An \exception{SMTPConnectError} is raised if the
 specified host doesn't respond correctly.
+The optional \var{timeout} parameter specifies a timeout in seconds for the
+connection attempt (if not specified, or passed as None, the global
+default timeout setting will be used).
 
 For normal use, you should only require the initialization/connect,
 \method{sendmail()}, and \method{quit()} methods.  An example is
@@ -31,7 +34,7 @@ included below.
 \begin{classdesc}{SMTP_SSL}{\optional{host\optional{, port\optional{,
                         local_hostname\optional{,
                         keyfile\optional{,
-                        certfile}}}}}}
+                        certfile\optional{, timeout}}}}}}}
 A \class{SMTP_SSL} instance behaves exactly the same as instances of \class{SMTP}.
 \class{SMTP_SSL} should be used for situations where SSL is required from 
 the beginning of the connection and using \method{starttls()} is not appropriate.
@@ -39,6 +42,9 @@ If \var{host} is not specified, the local host is used. If \var{port} is
 omitted, the standard SMTP-over-SSL port (465) is used. \var{keyfile} and \var{certfile}
 are also optional, and can contain a PEM formatted private key and
 certificate chain file for the SSL connection.
+The optional \var{timeout} parameter specifies a timeout in seconds for the
+connection attempt (if not specified, or passed as None, the global
+default timeout setting will be used).
 \end{classdesc}
 
 \begin{classdesc}{LMTP}{\optional{host\optional{, port\optional{,

Lib/smtplib.py

@@ -230,7 +230,7 @@ class SMTP:
     ehlo_resp = None
     does_esmtp = 0
 
-    def __init__(self, host = '', port = 0, local_hostname = None):
+    def __init__(self, host='', port=0, local_hostname=None, timeout=None):
         """Initialize a new instance.
 
         If specified, `host' is the name of the remote host to which to
@@ -241,6 +241,7 @@ class SMTP:
         the local hostname is found using socket.getfqdn().
 
         """
+        self.timeout = timeout
         self.esmtp_features = {}
         self.default_port = SMTP_PORT
         if host:
@@ -274,12 +275,11 @@ class SMTP:
         """
         self.debuglevel = debuglevel
 
-    def _get_socket(self,af, socktype, proto,sa):
+    def _get_socket(self, port, host, timeout):
         # This makes it simpler for SMTP_SSL to use the SMTP connect code
         # and just alter the socket connection bit.
-        self.sock = socket.socket(af, socktype, proto)
         if self.debuglevel > 0: print>>stderr, 'connect:', (host, port)
-        self.sock.connect(sa)
+        return socket.create_connection((port, host), timeout)
 
     def connect(self, host='localhost', port = 0):
         """Connect to a host on a given port.
@@ -301,21 +301,7 @@ class SMTP:
                     raise socket.error, "nonnumeric port"
         if not port: port = self.default_port
         if self.debuglevel > 0: print>>stderr, 'connect:', (host, port)
-        msg = "getaddrinfo returns an empty list"
-        self.sock = None
-        for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM):
-            af, socktype, proto, canonname, sa = res
-            try:
-                self._get_socket(af,socktype,proto,sa)
-            except socket.error, msg:
-                if self.debuglevel > 0: print>>stderr, 'connect fail:', msg
-                if self.sock:
-                    self.sock.close()
-                self.sock = None
-                continue
-            break
-        if not self.sock:
-            raise socket.error, msg
+        self.sock = self._get_socket(host, port, self.timeout)
         (code, msg) = self.getreply()
         if self.debuglevel > 0: print>>stderr, "connect:", msg
         return (code, msg)
@@ -732,17 +718,16 @@ class SMTP_SSL(SMTP):
     are also optional - they can contain a PEM formatted private key and
     certificate chain file for the SSL connection.
     """
-    def __init__(self, host = '', port = 0, local_hostname = None,
-                 keyfile = None, certfile = None):
+    def __init__(self, host='', port=0, local_hostname=None,
+                 keyfile=None, certfile=None, timeout=None):
         self.keyfile = keyfile
         self.certfile = certfile
-        SMTP.__init__(self,host,port,local_hostname)
+        SMTP.__init__(self, host, port, local_hostname, timeout)
         self.default_port = SMTP_SSL_PORT
 
-    def _get_socket(self,af, socktype, proto,sa):
-        self.sock = socket.socket(af, socktype, proto)
+    def _get_socket(self, host, port, timeout):
         if self.debuglevel > 0: print>>stderr, 'connect:', (host, port)
-        self.sock.connect(sa)
+        self.sock = socket.create_connection((host, port), timeout)
         sslobj = socket.ssl(self.sock, self.keyfile, self.certfile)
         self.sock = SSLFakeSocket(self.sock, sslobj)
         self.file = SSLFakeFile(sslobj)

Lib/test/test_smtplib.py

+import socket
+import threading
+import smtplib
+import time
+
+from unittest import TestCase
+from test import test_support
+
+
+def server(evt):
+    serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    serv.settimeout(3)
+    serv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    serv.bind(("", 9091))
+    serv.listen(5)
+    try:
+        conn, addr = serv.accept()
+    except socket.timeout:
+        pass
+    else:
+        conn.send("220 Hola mundo\n")
+        conn.close()
+    finally:
+        serv.close()
+        evt.set()
+
+class GeneralTests(TestCase):
+    
+    def setUp(self):
+        self.evt = threading.Event()
+        threading.Thread(target=server, args=(self.evt,)).start()
+        time.sleep(.1)
+
+    def tearDown(self):
+        self.evt.wait()
+
+    def testBasic(self):
+        # connects
+        smtp = smtplib.SMTP("localhost", 9091)
+        smtp.sock.close()
+        
+    def testTimeoutDefault(self):
+        # default
+        smtp = smtplib.SMTP("localhost", 9091)
+        self.assertTrue(smtp.sock.gettimeout() is None)
+        smtp.sock.close()
+    
+    def testTimeoutValue(self):
+        # a value
+        smtp = smtplib.SMTP("localhost", 9091, timeout=30)
+        self.assertEqual(smtp.sock.gettimeout(), 30)
+        smtp.sock.close()
+
+    def testTimeoutNone(self):
+        # None, having other default
+        previous = socket.getdefaulttimeout()
+        socket.setdefaulttimeout(30)
+        try:
+            smtp = smtplib.SMTP("localhost", 9091, timeout=None)
+        finally:
+            socket.setdefaulttimeout(previous)
+        self.assertEqual(smtp.sock.gettimeout(), 30)
+        smtp.sock.close()
+
+
+
+def test_main(verbose=None):
+    test_support.run_unittest(GeneralTests)
+
+if __name__ == '__main__':
+    test_main()