AutoVPN for NetworkManager

autovpn.py

#!/usr/bin/python
import sys

from dbus.mainloop.glib import DBusGMainLoop
import dbus
import gobject


class AutoVPN(object):
    """This should keep alive a VPN connection."""

    def __init__(self, vpn_name, max_attempts=5, delay=5000):
        self.vpn_name = vpn_name
        self.max_attempts = max_attempts
        self.delay = delay
        self.failed_attempts = 0
        self.bus = dbus.SystemBus()
        self.get_network_manager().connect_to_signal("StateChanged", self.onNetworkStateChanged)
        print "Maintaining connection for %s, reattempting up to %d times with %d ms between retries" % (vpn_name, max_attempts, delay)

    def onNetworkStateChanged(self, state):
        """Handles network status changes and activates the VPN on established connection."""
        print "Network state changed: %d" % state
        if state == 3:
            self.activate_vpn()

    def onVpnStateChanged(self, state, reason):
        """Handles different VPN status changes and eventually reconnects the VPN."""
        # vpn connected or user disconnected manually?
        if state == 5 or (state == 7 and reason == 2):
            print "VPN connected, or user disconnected manually"
            self.failed_attempts = 0
            return
        # connection failed or unknown?
        elif state in [6, 7]:
            # reconnect if we haven't reached max_attempts
            if not self.max_attempts or self.failed_attempts < self.max_attempts:
                print "Connection failed, attempting to reconnect"
                self.failed_attempts += 1
                gobject.timeout_add(self.delay, self.activate_vpn)
            else:
                print "Connection failed, exceeded %d max attempts." % self.max_attempts
                self.failed_attempts = 0

    def get_network_manager(self):
        """Gets the network manager dbus interface."""
        print "Getting NetworkManager DBUS interface"
        proxy = self.bus.get_object('org.freedesktop.NetworkManager', '/org/freedesktop/NetworkManager')
        return dbus.Interface(proxy, 'org.freedesktop.NetworkManager')

    def get_vpn_interface(self, name):
        'Gets the VPN connection interface with the specified name.'
        print "Getting %s VPN connection DBUS interface" % name
        proxy = self.bus.get_object('org.freedesktop.NetworkManagerUserSettings', '/org/freedesktop/NetworkManagerSettings')
        iface = dbus.Interface(proxy, 'org.freedesktop.NetworkManagerSettings')
        connections = iface.ListConnections()
        for connection in connections:
            proxy = self.bus.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:
                print "Got %s interface" % name
                return connection
        print "Unable to acquire %s VPN interface. Does it exist?" % name
        return None

    def get_active_connection(self):
        """Gets the dbus interface of the first active
        network connection or returns None.
        """
        print "Getting active network connection"
        proxy = self.bus.get_object('org.freedesktop.NetworkManager', '/org/freedesktop/NetworkManager')
        iface = dbus.Interface(proxy, 'org.freedesktop.DBus.Properties')
        active_connections = iface.Get('org.freedesktop.NetworkManager', 'ActiveConnections')
        if len(active_connections) == 0:
            print "No active connections found"
            return None
        print "Found %d active connection(s)" % active_connections.len
        return active_connections[0]

    def activate_vpn(self):
        'Activates the vpn connection.'
        print "Activating %s VPN connection" % self.vpn_name
        vpn_con = self.get_vpn_interface(self.vpn_name)
        active_con = self.get_active_connection()
        if vpn_con and active_con:
            new_con = self.get_network_manager().ActivateConnection(
                'org.freedesktop.NetworkManagerUserSettings',
                vpn_con,
                dbus.ObjectPath("/"),
                active_con,
            )
            proxy = self.bus.get_object('org.freedesktop.NetworkManager', new_con)
            iface = dbus.Interface(proxy, 'org.freedesktop.NetworkManager.VPN.Connection')
            iface.connect_to_signal('VpnStateChanged', self.onVpnStateChanged)
            print "VPN Connection %s should be active" % self.vpn_name


if __name__ == '__main__':
    if len(sys.argv) != 2:
        print 'usage: autovpn <VPN_CONNECTION_NAME>'
        sys.exit(0)

    # set up the main loop
    DBusGMainLoop(set_as_default=True)
    loop = gobject.MainLoop()

    AutoVPN(sys.argv[1])
    
    # execute the main loop
    loop.run()

Hi,

I have a question for this script. I have a openvpn configuration file(*.ovpn), and I want to use that file to create a VPN connection and activate it.

Do you have any suggestion on how to create a new VPN connection?

Thanks,
-Lei

Many thanks for this!

I've tweaked it lightly and updated for Python3 if anyone is interested.

Code: https://gitlab.com/kemonine/lolipop_lan_cloud/blob/master/docs/armbian/vpn_autoconnect.md