getting state of a VPN connection via DBus in Python

[Ariyan <ariyanster gmail com>]

I'm trying to get state of a VPN connection via DBus in Python.  

Here is my code:  

    name="testVPN"
    proxy = dbus.SystemBus().get_object('org.freedesktop.NetworkManagerUserSettings', '/org/freedesktop/NetworkManagerSettings')
    iface = dbus.Interface(proxy, 'org.freedesktop.NetworkManagerSettings')
    connections = iface.ListConnections()
    for connection in connections:
        proxy = dbus.SystemBus().get_object('org.freedesktop.NetworkManagerUserSettings', connection)
        iface = dbus.Interface(proxy, 'org.freedesktop.NetworkManagerSettings.Connection')
        con_settings = iface.GetSettings()['connection']
        if con_settings['type'] == 'vpn' and con_settings['id'] == name:

            state=dbus.Interface(proxy, 'org.freedesktop.DBus.Properties').Get('org.freedesktop.NetworkManager.VPN.Connection', 'VpnState')

 

This finds VPN connection correctly but in the last line (when trying to get `VpnState` property) it raises this Exception:  

    dbus.exceptions.DBusException: org.freedesktop.DBus.Error.AccessDenied: Rejected send message, 1 matched rules; type="method_call", sender=":1.169" (uid=0 pid=20580 comm="python) interface="org.freedesktop.DBus.Properties" member="Get" error name="(unset)" requested_reply=0 destination=":1.36" (uid=1000 pid=3457 comm="nm-applet))

What is the problem?