Initial implementation of SMPP multipart messages using painstakingly…

… handcrafted user data headers.

vumi/transports/smpp/clientserver/client.py

@@ -459,6 +459,7 @@ def submit_sm(self, **kwargs):
             returnValue(0)
 
         sar_params = kwargs.pop('sar_params', None)
+        has_udh = kwargs.pop('has_udh', False)
 
         pdu_params = self.bind_params.copy()
         pdu_params.update(kwargs)
@@ -470,6 +471,12 @@ def submit_sm(self, **kwargs):
                     **pdu_params)
                 returnValue(sequence_number)
 
+        if self.config.send_multipart_udh and not has_udh:
+            if len(message) > 130:
+                sequence_number = yield self._submit_multipart_udh(
+                    **pdu_params)
+                returnValue(sequence_number)
+
         sequence_number = yield self.get_next_seq()
 
         pdu = SubmitSM(sequence_number, **pdu_params)
@@ -508,6 +515,24 @@ def _submit_multipart_sar(self, **pdu_params):
             sequence_number = yield self.submit_sm(**params)
         returnValue(sequence_number)
 
+    @inlineCallbacks
+    def _submit_multipart_udh(self, **pdu_params):
+        message = pdu_params['short_message']
+        split_msg = []
+        while message:
+            split_msg.append(message[:130])
+            message = message[130:]
+        ref_num = randint(1, 255)
+        for i, msg in enumerate(split_msg):
+            params = pdu_params.copy()
+            params['has_udh'] = True
+            params['esm_class'] = 0x40
+            udh = '\05\00\03%s%s%s' % (
+                chr(ref_num), chr(len(split_msg)), chr(i + 1))
+            params['short_message'] = udh + msg
+            sequence_number = yield self.submit_sm(**params)
+        returnValue(sequence_number)
+
     @inlineCallbacks
     def enquire_link(self, **kwargs):
         if self.state in ['BOUND_TX', 'BOUND_RX', 'BOUND_TRX']:

vumi/transports/smpp/clientserver/tests/test_client.py

@@ -237,6 +237,38 @@ def test_submit_sm_sms_multipart_sar(self):
         self.assertEqual(long_message, ''.join(msg_parts))
         self.assertEqual(1, len(set(msg_refs)))
 
+    @inlineCallbacks
+    def test_submit_sm_sms_multipart_udh(self):
+        """Submit a long SMS message using multipart user data headers."""
+        esme = yield self.get_esme(config={
+            'send_multipart_udh': True,
+        })
+        long_message = 'This is a long message.' * 20
+        yield esme.submit_sm(short_message=long_message)
+        self.assertEqual(4, len(esme.fake_sent_pdus))
+        msg_parts = []
+        msg_refs = []
+
+        for i, sm_pdu in enumerate(esme.fake_sent_pdus):
+            sm = unpack_pdu(sm_pdu.get_bin())
+            mandatory_parameters = sm['body']['mandatory_parameters']
+            self.assertEqual('submit_sm', sm['header']['command_id'])
+            msg = mandatory_parameters['short_message']
+
+            udh_hlen, udh_tag, udh_len, udh_ref, udh_tot, udh_seq = [
+                ord(octet) for octet in msg[:6]]
+            self.assertEqual(5, udh_hlen)
+            self.assertEqual(0, udh_tag)
+            self.assertEqual(3, udh_len)
+            msg_refs.append(udh_ref)
+            self.assertEqual(4, udh_tot)
+            self.assertEqual(i + 1, udh_seq)
+            msg_parts.append(msg[6:])
+            self.assertEqual(0x40, mandatory_parameters['esm_class'])
+
+        self.assertEqual(long_message, ''.join(msg_parts))
+        self.assertEqual(1, len(set(msg_refs)))
+
     @inlineCallbacks
     def test_submit_sm_ussd_continue(self):
         """Submit a USSD message with a session continue flag."""

vumi/transports/smpp/transport.py

@@ -101,6 +101,10 @@ class SmppTransportConfig(Transport.CONFIG_CLASS):
         "If `True`, messages longer than 140 bytes will be sent as a series "
         "of smaller messages with the sar_* parameters set. Default is "
         "`False`.", default=False, static=True)
+    send_multipart_udh = ConfigBool(
+        "If `True`, messages longer than 140 bytes will be sent as a series "
+        "of smaller messages with the user data headers. Default is `False`.",
+        default=False, static=True)
     split_bind_prefix = ConfigText(
         "This is the Redis prefix to use for storing things like sequence "
         "numbers and message ids for delivery report handling. It defaults "