Initial implementation of SMPP multipart messages using SAR parameters.

vumi/transports/smpp/clientserver/client.py

@@ -2,6 +2,7 @@
 
 import json
 import uuid
+from random import randint
 
 from twisted.internet import reactor
 from twisted.internet.protocol import Protocol, ClientFactory
@@ -457,23 +458,56 @@ def submit_sm(self, **kwargs):
                      'dropping message: %s' % (self.state, kwargs)))
             returnValue(0)
 
-        sequence_number = yield self.get_next_seq()
+        sar_params = kwargs.pop('sar_params', None)
+
         pdu_params = self.bind_params.copy()
         pdu_params.update(kwargs)
+        message = pdu_params['short_message']
+
+        if self.config.send_multipart_sar and sar_params is None:
+            if len(message) > 130:
+                sequence_number = yield self._submit_multipart_sar(
+                    **pdu_params)
+                returnValue(sequence_number)
+
+        sequence_number = yield self.get_next_seq()
 
         pdu = SubmitSM(sequence_number, **pdu_params)
         if kwargs.get('message_type', 'sms') == 'ussd':
             update_ussd_pdu(pdu, kwargs.get('continue_session', True),
                             kwargs.get('session_info', None))
 
-        message = pdu_params['short_message']
         if self.config.send_long_messages and len(message) > 254:
             pdu.add_message_payload(''.join('%02x' % ord(c) for c in message))
 
+        if sar_params:
+            pdu.set_sar_msg_ref_num(sar_params['msg_ref_num'])
+            pdu.set_sar_total_segments(sar_params['total_segments'])
+            pdu.set_sar_segment_seqnum(sar_params['segment_seqnum'])
+
         self.send_pdu(pdu)
         yield self.push_unacked(sequence_number)
         returnValue(sequence_number)
 
+    @inlineCallbacks
+    def _submit_multipart_sar(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['short_message'] = msg
+            params['sar_params'] = {
+                'msg_ref_num': ref_num,
+                'total_segments': len(split_msg),
+                'segment_seqnum': i + 1,
+            }
+            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

@@ -211,6 +211,32 @@ def test_submit_sm_sms_long(self):
         self.assertEqual(''.join('%02x' % ord(c) for c in long_message),
                          pdu_opts['message_payload'])
 
+    @inlineCallbacks
+    def test_submit_sm_sms_multipart_sar(self):
+        """Submit a long SMS message using multipart sar fields."""
+        esme = yield self.get_esme(config={
+            'send_multipart_sar': 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())
+            pdu_opts = unpacked_pdu_opts(sm)
+            mandatory_parameters = sm['body']['mandatory_parameters']
+
+            self.assertEqual('submit_sm', sm['header']['command_id'])
+            msg_parts.append(mandatory_parameters['short_message'])
+            msg_refs.append(pdu_opts['sar_msg_ref_num'])
+            self.assertEqual(i + 1, pdu_opts['sar_segment_seqnum'])
+            self.assertEqual(4, pdu_opts['sar_total_segments'])
+
+        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

@@ -97,6 +97,10 @@ class SmppTransportConfig(Transport.CONFIG_CLASS):
         "`message_payload` optional field instead of the `short_message` "
         "field. Default is `False`, simply because that maintains previous "
         "behaviour.", default=False, static=True)
+    send_multipart_sar = ConfigBool(
+        "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)
     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 "