add osmo-mslookup-client program (#2)

Standalone program using libosmo-mslookup to easily integrate with programs
that want to connect services (SIP, SMS,...) to the current location of a
subscriber. Also useful for manual testing.

For a detailed overview of the D-GSM and mslookup related files, please see the
elaborate comment at the top of mslookup.c (already added in an earlier patch).

Resubmit of 637bbfcd92 after revert in
41fe362591.

Change-Id: Ie39d30e20461ab10ae3584863d8bfc6b76a12f37

contrib/Makefile.am

@@ -1 +1,4 @@
-SUBDIRS = systemd
+SUBDIRS = \
+	systemd \
+	dgsm \
+	$(NULL)

contrib/dgsm/Makefile.am

@@ -0,0 +1,4 @@
+EXTRA_DIST = \
+	osmo-mslookup-pipe.py \
+	osmo-mslookup-socket.py \
+	$(NULL)

contrib/dgsm/osmo-mslookup-pipe.py

@@ -0,0 +1,24 @@
+#!/usr/bin/env python3
+# vim: shiftwidth=4 tabstop=4 expandtab
+import subprocess
+import json
+
+def query_mslookup(query_str):
+    result = {'result': 'not-found'}
+    proc = subprocess.Popen(('osmo-mslookup-client', '-f', 'json', query_str),
+		            stdout=subprocess.PIPE)
+    for line in iter(proc.stdout.readline,''):
+        if not line:
+            break
+        response = json.loads(line)
+        if response.get('result') == 'result':
+                result = response
+        print('Response: %r' % response)
+    return result
+
+if __name__ == '__main__':
+    import sys
+    query_str = '1000-5000@sip.voice.12345.msisdn'
+    if len(sys.argv) > 1:
+        query_str = sys.argv[1]
+    print('Final result: %r' % query_mslookup(query_str))

contrib/dgsm/osmo-mslookup-socket.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+# vim: shiftwidth=4 tabstop=4 expandtab
+import socket
+import time
+
+MSLOOKUP_SOCKET_PATH = '/tmp/mslookup'
+
+def query_mslookup_socket(query_str, socket_path=MSLOOKUP_SOCKET_PATH):
+    mslookup_socket = socket.socket(socket.AF_UNIX, socket.SOCK_SEQPACKET)
+    mslookup_socket.setblocking(True)
+    mslookup_socket.connect(socket_path)
+    result = {'result': 'not-found'}
+    column_names = mslookup_socket.recv(1024).decode('ascii')
+    if not column_names:
+        return result
+    column_names = column_names.split('\t')
+    mslookup_socket.sendall(query_str.encode('ascii'))
+    while True:
+        csv = mslookup_socket.recv(1024).decode('ascii')
+        if not csv:
+            break
+        response = dict(zip(column_names, csv.split('\t')))
+        if response.get('result') == 'result':
+            result = response
+        print('Response: %r' % response)
+    return result
+
+if __name__ == '__main__':
+    import sys
+    print(
+        '\nPlease run separately: osmo-mslookup-client --socket /tmp/mslookup -d\n')
+    query_str = '1000-5000@sip.voice.12345.msisdn'
+    if len(sys.argv) > 1:
+        query_str = sys.argv[1]
+    print('Final result: %r' % query_mslookup_socket(query_str))