contrib/esme_mslookup.py: new file

Add example script for the distributed GSM network, which connects to
the SMPP port of OsmoMSC A and forwards SMS to the SMPP port of
OsmoMSC B. The IP and port of OsmoMSC B is retrieved by the receiver's
MSISDN using osmo-mslookup-client.

Related: OS#4254
Change-Id: I56372d6d66c6fb54ae3fcc052543fd78f8a5ef1e

1 files changed, 179 insertions, 0 deletions

diff --git a/contrib/esme_mslookup.py b/contrib/esme_mslookup.py
new file mode 100755
index 000000000..6751eb7ce
--- /dev/null
+++ b/contrib/esme_mslookup.py
@@ -0,0 +1,179 @@
+#!/usr/bin/env python3
+"""
+SPDX-License-Identifier: AGPL-3.0-or-later
+Copyright 2019 sysmocom s.f.m.c GmbH <info@sysmocom.de>
+
+Based on esme.py from RCCN:
+https://github.com/Rhizomatica/rccn/blob/master/rccn/esme.py
+Copyright 2017 keith <keith@rhizomatica.org>
+
+Forward SMS to the receiver's SMSC, as determined with mslookup.
+Requires smpplip (pip3 install --user smpplib) and osmo-mslookup-client.
+
+Example SMPP configuration for osmo-msc.cfg:
+smpp
+ local-tcp-ip 127.0.0.1 2775
+ policy closed
+ smpp-first
+# outgoing to esme_mslookup.py
+ esme OSMPP
+  no alert-notifications
+  password foo
+  default-route
+# incoming from esme_mslookup.py
+ esme ISMPP
+  no alert-notifications
+  password foo
+"""
+import argparse
+import json
+import logging
+import smpplib
+import subprocess
+import threading
+import time
+
+
+def can_handle_pdu(pdu):
+    if not isinstance(pdu, smpplib.command.DeliverSM):
+        logging.info('PDU is not a DeliverSM. Is OsmoMSC configured properly?')
+        return False
+
+    # Multipart SMS etc. not handled here (see RCCN's esme.py)
+    if pdu.esm_class & smpplib.consts.SMPP_GSMFEAT_UDHI:
+        logging.info("UDH (User Data Header) handling not implemented in this"
+                     " example, dropping message.")
+        return False
+
+    if int(pdu.dest_addr_ton) == smpplib.consts.SMPP_TON_INTL:
+        logging.info("Unable to handle SMS for %s: SMPP_TON_INTL" %
+                     (pdu.destination_addr))
+        return False
+
+    return True
+
+
+def query_mslookup(service_type, id, id_type='msisdn'):
+    query_str = '%s.%s.%s' % (service_type, id, id_type)
+    logging.info('mslookup: ' + query_str)
+
+    result_line = subprocess.check_output(['osmo-mslookup-client', query_str,
+                                           '-f', 'json'])
+    if isinstance(result_line, bytes):
+        result_line = result_line.decode('ascii')
+
+    logging.info('mslookup result: ' + result_line.rstrip())
+    return json.loads(result_line)
+
+
+def tx_sms(dst_host, dst_port, source, destination, unicode_text):
+    smpp_client = smpplib.client.Client(dst_host, dst_port, 90)
+    smpp_client.connect()
+    smpp_client.bind_transceiver(system_id=args.dst_id, password=args.dst_pass)
+    logging.info('Connected to destination SMSC (%s@%s:%s)' % (args.dst_id,
+                 dst_host, dst_port))
+
+    pdu = smpp_client.send_message(
+        source_addr_ton=smpplib.consts.SMPP_TON_ALNUM,
+        source_addr_npi=smpplib.consts.SMPP_NPI_UNK,
+        source_addr=source.decode(),
+        dest_addr_ton=smpplib.consts.SMPP_TON_SBSCR,
+        dest_addr_npi=smpplib.consts.SMPP_NPI_ISDN,
+        destination_addr=destination.decode(),
+        short_message=unicode_text,
+        registered_delivery=False,
+    )
+
+    smpp_client.unbind()
+    smpp_client.disconnect()
+    del pdu
+    del smpp_client
+
+
+thread_id_short = 0
+
+
+class ForwardSMSThread(threading.Thread):
+    def __init__(self, pdu):
+        global thread_id_short
+        name = "ForwardSMSThread#" + str(thread_id_short)
+        thread_id_short += 1
+
+        threading.Thread.__init__(self, name=name)
+        self.pdu = pdu
+
+    def run(self):
+        logging.info("Thread started")
+        msisdn = self.pdu.destination_addr.decode()
+        result = query_mslookup("smpp.sms", msisdn)
+        if 'v4' not in result or not result['v4']:
+            logging.info('No IPv4 result from mslookup! This example only'
+                         ' makes use of IPv4, dropping.')
+            return
+
+        if args.sleep:
+            logging.info("Sleeping for %i seconds" % (args.sleep))
+            time.sleep(args.sleep)
+            logging.info("Sleep done")
+
+        dst_host, dst_port = result['v4']
+        tx_sms(dst_host, dst_port, self.pdu.source_addr,
+               self.pdu.destination_addr, self.pdu.short_message)
+        logging.info("Thread is done")
+
+
+def rx_deliver_sm(pdu):
+    if not can_handle_pdu(pdu):
+        return smpplib.consts.SMPP_ESME_RSYSERR
+
+    # Start a background thread for every incoming SMS, so we are not blocking
+    # until mslookup is done. For real world usage, one needs to store SMS that
+    # failed to deliver in the thread and try again later.
+    thread = ForwardSMSThread(pdu)
+    thread.start()
+
+    return smpplib.consts.SMPP_ESME_ROK
+
+
+def smpp_bind():
+    client = smpplib.client.Client(args.src_host, args.src_port, 90)
+    client.set_message_received_handler(rx_deliver_sm)
+    client.connect()
+    client.bind_transceiver(system_id=args.src_id, password=args.src_pass)
+    logging.info('Connected to source SMSC (%s@%s:%s)' % (args.src_id,
+                 args.src_host, args.src_port))
+    logging.info('Waiting for SMS...')
+    client.listen()
+
+
+def main():
+    global args
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--src-host', default='127.0.0.1',
+                        help='source SMSC (OsmoMSC) host (default: 127.0.0.1)')
+    parser.add_argument('--src-port', default=2775, type=int,
+                        help='source SMSC (OsmoMSC) port (default: 2775)')
+    parser.add_argument('--src-id', default='OSMPP',
+                        help='source system id, as configured in osmo-msc.cfg'
+                             ' (default: OSMPP)')
+    parser.add_argument('--src-pass', default='foo',
+                        help='source system password, as configured in'
+                             ' osmo-msc.cfg (default: foo)')
+    parser.add_argument('--dst-id', default='ISMPP',
+                        help='destination system id, as configured in'
+                             ' osmo-msc.cfg (default: ISMPP)')
+    parser.add_argument('--dst-pass', default='foo',
+                        help='destination system password, as configured in'
+                             ' osmo-msc.cfg (default: foo)')
+    parser.add_argument('--sleep', default=0, type=float,
+                        help='sleep time in seconds before forwarding an SMS,'
+                             ' to test multithreading (default: 0)')
+    args = parser.parse_args()
+
+    logging.basicConfig(level=logging.INFO, format='[%(asctime)s]'
+                        ' (%(threadName)s) %(message)s', datefmt="%H:%M:%S")
+    smpp_bind()
+
+
+if __name__ == "__main__":
+    main()