#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
 
import dbus, sys
from dbus.mainloop.glib import DBusGMainLoop
 
DBusGMainLoop(set_as_default=True)
 
def init():
	"""
	Preconnection instructions
	"""
	global bus
	bus = dbus.SystemBus()
 
def is_poisson_vpn(settings):
	"""
	Recognize poisson vpn from the settings returned
	by dbus
	"""
	if settings['connection']['type'] != "vpn":
		return False
	if settings['vpn']['data']['remote'] != "poisson.phc-priv":
		return False
 
	# 1194 is the default port for the VPN so you don't need to specify it in the
	# configuration, but if you do and if you speciy something different from 1194,
	# this is not the right VPN
	if settings['vpn']['data'].has_key("port") and settings['vpn']['data']['port'] != 1194:
		return False
 
	# If you arrived here this really is poisson vpn!
	return True
 
def get_poisson_vpn():
	"""
	Obtain DBus object for the poisson vpn connection
	"""
 
	# Try to load configuration for the VPN to poisson
	proxy = bus.get_object("org.freedesktop.NetworkManagerUserSettings",
						   "/org/freedesktop/NetworkManagerSettings")
	interface = dbus.Interface(proxy, "org.freedesktop.NetworkManagerSettings")
 
	# If we can't find the vpn matching the following:
	#  - remote: poisson.phc-priv
	#  - port:   1194
	# then we return None
	c = None
 
	# Check all connections stored in UserSettings to see if they match the
	# Poisson vpn. We don't check SystemSettings at the moment being because
	# it's likely to require root privileges (or not?)
	for connection in interface.ListConnections():
		proxy = bus.get_object("org.freedesktop.NetworkManagerUserSettings",
							   connection)
		settings = proxy.GetSettings(dbus_interface="org.freedesktop.NetworkManagerSettings.Connection")
 
		# This should be a deterministic check :)
		if is_poisson_vpn (settings):
			c = connection
 
	# Check if VPN is already active. If it is, return None because we have nothing
	# to do
	proxy = bus.get_object("org.freedesktop.NetworkManager", "/org/freedesktop/NetworkManager")
	interface = dbus.Interface(proxy, "org.freedesktop.DBus.Properties")
 
	# Try to match ConnectionSettings to an ActiveConnection
	for connection in interface.Get("org.freedesktop.NetworkManager", "ActiveConnections"):
		proxy = bus.get_object("org.freedesktop.NetworkManager", connection)
		interface = dbus.Interface(proxy, "org.freedesktop.DBus.Properties")
		connection = interface.Get("org.freedesktop.NetworkManager.Connection.Active", "Connection")
		if connection == c:
			return None
 
	# Return the connection (or None)
	return c
 
def get_base_connection():
	"""
	Obtain active connection if matching the ones that can connect to
	poisson.phc-priv. If not, return None
	"""
 
	# Get the list of the active connections right now
	proxy = bus.get_object("org.freedesktop.NetworkManager",
						   "/org/freedesktop/NetworkManager")
	interface = dbus.Interface(proxy, "org.freedesktop.DBus.Properties")
	active_connections = interface.Get('org.freedesktop.NetworkManager', 'ActiveConnections')
 
	# Examine every active connection and if one of the matching MAC address
	# is found return the connection object
	for connection in active_connections:
		proxy = bus.get_object("org.freedesktop.NetworkManager",
							   connection)
		interface = dbus.Interface(proxy, "org.freedesktop.DBus.Properties")
		path = interface.Get('org.freedesktop.NetworkManager.Connection.Active', 'Connection')
 
		proxy = bus.get_object('org.freedesktop.NetworkManagerUserSettings',
							   path)
		interface = dbus.Interface(proxy, 'org.freedesktop.NetworkManagerSettings.Connection')
		settings = interface.GetSettings()
 
		# Check if the user is connected to a known wireless ap. If it is, then
		# we can activate the VPN so we return a connection DBus object
		if settings.has_key("802-11-wireless"):
 
			# MAC address of CDCWL1 ap
			if settings['802-11-wireless']['seen-bssids'][0] == u'00:12:0E:8C:AE:A0':
				return connection
 
			# MAC address of PHC-wifi ap
			if settings['802-11-wireless']['seen-bssids'][0] == u'00:0f:cb:aa:16:52':
				return connection
 
	# The active connections aren't directly connected to poisson.phc-priv
	# so we can't activate the VPN
	return None
 
 
def activate_connection(connection):
	"""
	Activate connection
	"""
	proxy = bus.get_object("org.freedesktop.NetworkManager",
						   "/org/freedesktop/NetworkManager")
	interface = dbus.Interface (proxy, "org.freedesktop.NetworkManager")
 
	# Obtain base connection to active VPN on
	base_connection = get_base_connection ()
 
	if base_connection is not None:
		interface.ActivateConnection('org.freedesktop.NetworkManagerUserSettings',
									 connection,
									 dbus.ObjectPath("/"),
									 base_connection)
 
if __name__ == "__main__":
 
	# If you turn vpn donw you probably don't
	# want me to fire it up again
	if sys.argv[2] == "vpn-down":
		sys.exit (0)
 
	# If you just tried to attach a VPN, you probably
	# don't want another one
	if sys.argv[2] == "vpn-up":
		sys.exit (0)
 
	# If you deconfigured an interface, you probably
	# don't want to autostart a VPN (o sì? :))
	if sys.argv[2] == "down":
		sys.exit (0)
 
	# Preconnection scripts
	init ()
 
	# Obtain poisson vpn
	poisson_vpn = get_poisson_vpn ()
 
	# If poisson_vpn is None it means that it
	# is already active, so exit now
	if (poisson_vpn is None):
		sys.exit (0)
 
	# Activate connection
	activate_connection (poisson_vpn)