added timeout to oppened tunnel to avoid possible DOS

tunnel-server/src/udstunnel.py

@@ -222,6 +222,7 @@ def tunnel_main():
         while not do_stop:
             try:
                 client, addr = sock.accept()
+                client.settimeout(3.0)
                 logger.debug('ACCEPTED CONNECTION from %s (%s)', addr, client)
                 # Select BEST process for sending this new connection
                 prcs.best_child().send((client, addr))