Traceback (most recent call last):
  File "/usr/share/hwtest/scripts/internet_test", line 132, in <module>
    sys.exit(main(sys.argv[1:]))
  File "/usr/share/hwtest/scripts/internet_test", line 118, in main
    host = route.get_default_gateway()
  File "/usr/share/hwtest/scripts/internet_test", line 81, in get_default_gateway
    t1 = self._get_default_gateway_from_bin_route()
  File "/usr/share/hwtest/scripts/internet_test", line 69, in _get_default_gateway_from_bin_route
    if def_gateway:
UnboundLocalError: local variable 'def_gateway' referenced before assignment