iwd/autotests/util/iwd.py

#!/usr/bin/python3
from gi.repository import GLib

import dbus
import dbus.service
import dbus.mainloop.glib
import sys
import os
import threading
import time
import collections
import datetime

from abc import ABCMeta, abstractmethod
from enum import Enum

import wiphy

IWD_STORAGE_DIR =               '/var/lib/iwd'
IWD_CONFIG_DIR =                '/etc/iwd'

DBUS_OBJECT_MANAGER =           'org.freedesktop.DBus.ObjectManager'
DBUS_PROPERTIES =               'org.freedesktop.DBus.Properties'

IWD_SERVICE =                   'net.connman.iwd'
IWD_WIPHY_INTERFACE =           'net.connman.iwd.Adapter'
IWD_AGENT_INTERFACE =           'net.connman.iwd.Agent'
IWD_AGENT_MANAGER_INTERFACE =   'net.connman.iwd.AgentManager'
IWD_DEVICE_INTERFACE =          'net.connman.iwd.Device'
IWD_KNOWN_NETWORK_INTERFACE =   'net.connman.iwd.KnownNetwork'
IWD_NETWORK_INTERFACE =         'net.connman.iwd.Network'
IWD_WSC_INTERFACE =             'net.connman.iwd.WiFiSimpleConfiguration'
IWD_SIGNAL_AGENT_INTERFACE =    'net.connman.iwd.SignalLevelAgent'
IWD_AP_INTERFACE =              'net.connman.iwd.AccessPoint'
IWD_ADHOC_INTERFACE =           'net.connman.iwd.AdHoc'
IWD_STATION_INTERFACE =         'net.connman.iwd.Station'

IWD_AGENT_MANAGER_PATH =        '/'
IWD_TOP_LEVEL_PATH =            '/'


dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)


class UnknownDBusEx(Exception): pass
class InProgressEx(dbus.DBusException): pass
class FailedEx(dbus.DBusException): pass
class AbortedEx(dbus.DBusException): pass
class NotAvailableEx(dbus.DBusException): pass
class InvalidArgsEx(dbus.DBusException): pass
class AlreadyExistsEx(dbus.DBusException): pass
class NotFoundEx(dbus.DBusException): pass
class NotSupportedEx(dbus.DBusException): pass
class NoAgentEx(dbus.DBusException): pass
class NotConnectedEx(dbus.DBusException): pass
class NotConfiguredEx(dbus.DBusException): pass
class NotImplementedEx(dbus.DBusException): pass
class ServiceSetOverlapEx(dbus.DBusException): pass
class AlreadyProvisionedEx(dbus.DBusException): pass
class NotHiddenEx(dbus.DBusException): pass
class CanceledEx(dbus.DBusException):
    _dbus_error_name = 'net.connman.iwd.Error.Canceled'


_dbus_ex_to_py = {
    'Canceled' :        CanceledEx,
    'InProgress' :      InProgressEx,
    'Failed' :          FailedEx,
    'Aborted' :         AbortedEx,
    'NotAvailable' :    NotAvailableEx,
    'InvalidArgs' :     InvalidArgsEx,
    'AlreadyExists' :   AlreadyExistsEx,
    'NotFound' :        NotFoundEx,
    'NotSupported' :    NotSupportedEx,
    'NoAgent' :         NoAgentEx,
    'NotConnected' :    NotConnectedEx,
    'NotConfigured' :   NotConfiguredEx,
    'NotImplemented' :  NotImplementedEx,
    'ServiceSetOverlap' :  ServiceSetOverlapEx,
    'AlreadyProvisioned' : AlreadyProvisionedEx,
    'NotHidden' :       NotHiddenEx,
}


def _convert_dbus_ex(dbus_ex):
    ex_name = dbus_ex.get_dbus_name()
    ex_short_name = ex_name[ex_name.rfind(".") + 1:]
    if ex_short_name in _dbus_ex_to_py:
        return _dbus_ex_to_py[ex_short_name](dbus_ex)
    else:
        return UnknownDBusEx(ex_name + ': ' + dbus_ex.get_dbus_message())


class AsyncOpAbstract(object):
    __metaclass__ = ABCMeta

    _is_completed = False
    _exception = None

    def _success(self):
        self._is_completed = True

    def _failure(self, ex):
        self._is_completed = True
        self._exception = _convert_dbus_ex(ex)

    def _wait_for_async_op(self):
        context = mainloop.get_context()
        while not self._is_completed:
            context.iteration(may_block=True)

        self._is_completed = False
        if self._exception is not None:
            tmp = self._exception
            self._exception = None
            raise tmp


class IWDDBusAbstract(AsyncOpAbstract):
    __metaclass__ = ABCMeta

    _bus = dbus.SystemBus()

    def __init__(self, object_path = None, properties = None):
        self._object_path = object_path
        proxy = self._bus.get_object(IWD_SERVICE, self._object_path)
        self._iface = dbus.Interface(proxy, self._iface_name)
        self._prop_proxy = dbus.Interface(proxy, DBUS_PROPERTIES);

        if properties is None:
            self._properties = self._prop_proxy.GetAll(self._iface_name)
        else:
            self._properties = properties

        self._prop_proxy.connect_to_signal("PropertiesChanged",
                                           self._property_changed_handler,
                                           DBUS_PROPERTIES,
                                           path_keyword="path")

    def _property_changed_handler(self, interface, changed, invalidated, path):
        if interface == self._iface_name and path == self._object_path:
            for name, value in changed.items():
                self._properties[name] = value

    @abstractmethod
    def __str__(self):
        pass


class DeviceState(Enum):
    '''Conection state of a device'''
    connected =     'connected'
    disconnected =  'disconnected'
    connecting =    'connecting'
    disconnecting = 'disconnecting'
    roaming =       'roaming'

    def __str__(self):
        return self.value

    @classmethod
    def from_str(cls, string):
        return getattr(cls, string, None)


class NetworkType(Enum):
    '''Network security type'''
    open =  'open'
    psk =   'psk'
    eap =   '8021x'

    def __str__(self):
        return str(self.value)

    @classmethod
    def from_string(cls, string):
        type = None
        for attr in dir(cls):
            if (str(getattr(cls, attr)) == string):
                type = getattr(cls, attr)
                break
        return type


class SignalAgent(dbus.service.Object):
    def __init__(self, passphrase = None):
        self._path = '/test/agent/' + str(int(round(time.time() * 1000)))

        dbus.service.Object.__init__(self, dbus.SystemBus(), self._path)

    @property
    def path(self):
        return self._path

    @dbus.service.method(IWD_SIGNAL_AGENT_INTERFACE,
                         in_signature='', out_signature='')
    def Release(self):
        print("SignalAgent released")

    @dbus.service.method(IWD_SIGNAL_AGENT_INTERFACE,
                         in_signature='oy', out_signature='')
    def Changed(self, path, level):
        self.handle_new_level(str(path), int(level))

    @abstractmethod
    def handle_new_level(self, path, level):
        pass


class Device(IWDDBusAbstract):
    '''
        Class represents a network device object: net.connman.iwd.Device
        with its properties and methods
    '''
    _iface_name = IWD_DEVICE_INTERFACE
    _wps_manager_if = None
    _station_if = None

    @property
    def _wps_manager(self):
        if self._wps_manager_if is None:
            _wps_manager_if =\
                dbus.Interface(self._bus.get_object(IWD_SERVICE,
                                                    self.device_path),
                               IWD_WSC_INTERFACE)
        return _wps_manager_if

    @property
    def _station(self):
        if self._station_if is None:
            _station_if = dbus.Interface(self._bus.get_object(IWD_SERVICE,
                                                            self.device_path),
                                            IWD_STATION_INTERFACE)
        return _station_if

    @property
    def device_path(self):
        '''
            Device's dbus path.

            @rtype: string
        '''
        return self._object_path

    @property
    def name(self):
        '''
            Device's interface name.

            @rtype: string
        '''
        return self._properties['Name']

    @property
    def address(self):
        '''
            Interface's hardware address in the XX:XX:XX:XX:XX:XX format.

            @rtype: string
        '''
        return self._properties['Address']

    @property
    def state(self):
        '''
            Reflects the general network connection state.

            @rtype: object (State)
        '''
        return DeviceState.from_str(self._properties['State'])

    @property
    def connected_network(self):
        '''
            net.connman.iwd.Network object representing the
            network the device is currently connected to or to
            which a connection is in progress.

            @rtype: object (Network)
        '''
        return self._properties.get('ConnectedNetwork')

    @property
    def powered(self):
        '''
            True if the interface is UP. If false, the device's radio is
            powered down and no other actions can be performed on the device.

            @rtype: boolean
        '''
        return bool(self._properties['Powered'])

    @property
    def scanning(self):
        '''
        Reflects whether the device is currently scanning
        for networks.  net.connman.iwd.Network objects are
        updated when this property goes from true to false.

        @rtype: boolean
        '''
        return bool(self._properties['Scanning'])

    def scan(self):
        '''Schedule a network scan.

           Possible exception: BusyEx
                               FailedEx
        '''
        self._iface.Scan(dbus_interface=IWD_STATION_INTERFACE,
                               reply_handler=self._success,
                               error_handler=self._failure)

        self._wait_for_async_op()

    def disconnect(self):
        '''Disconnect from the network

           Possible exception: BusyEx
                               FailedEx
                               NotConnectedEx
        '''
        self._iface.Disconnect(dbus_interface=IWD_STATION_INTERFACE,
                               reply_handler=self._success,
                               error_handler=self._failure)

        self._wait_for_async_op()

    def get_ordered_networks(self):
        '''Return the list of networks found in the most recent
           scan, sorted by their user interface importance
           score as calculated by iwd.  If the device is
           currently connected to a network, that network is
           always first on the list, followed by any known
           networks that have been used at least once before,
           followed by any other known networks and any other
           detected networks as the last group.  Within these
           groups the maximum relative signal-strength is the
           main sorting factor.
        '''
        ordered_networks = []
        for bus_obj in self._station.GetOrderedNetworks():
            ordered_network = OrderedNetwork(bus_obj)
            ordered_networks.append(ordered_network)
        return ordered_networks

    def wps_push_button(self):
        self._wps_manager.PushButton(dbus_interface=IWD_WSC_INTERFACE,
                                     reply_handler=self._success,
                                     error_handler=self._failure)
        self._wait_for_async_op()

    def wps_cancel(self):
        self._wps_manager.Cancel(dbus_interface=IWD_WSC_INTERFACE,
                                 reply_handler=self._success,
                                 error_handler=self._failure)
        self._wait_for_async_op()

    def register_signal_agent(self, signal_agent, levels):
        self._station.RegisterSignalLevelAgent(signal_agent.path,
                                        dbus.Array(levels, 'n'),
                                        dbus_interface=IWD_STATION_INTERFACE,
                                        reply_handler=self._success,
                                        error_handler=self._failure)
        self._wait_for_async_op()

    def unregister_signal_agent(self, signal_agent):
        self._station.UnregisterSignalLevelAgent(signal_agent.path,
                                        dbus_interface=IWD_STATION_INTERFACE,
                                        reply_handler=self._success,
                                        error_handler=self._failure)
        self._wait_for_async_op()

    def start_ap(self, ssid, psk):
        self._prop_proxy.Set(IWD_DEVICE_INTERFACE, 'Mode', 'ap')
        self._ap_iface = dbus.Interface(self._bus.get_object(IWD_SERVICE,
                                            self.device_path),
                                            IWD_AP_INTERFACE)
        self._ap_iface.Start(ssid, psk, reply_handler=self._success,
                                     error_handler=self._failure)
        self._wait_for_async_op()

    def stop_ap(self):
        self._prop_proxy.Set(IWD_DEVICE_INTERFACE, 'Mode', 'station')

    def connect_hidden_network(self, name):
        '''Connect to a hidden network
           Possible exception: BusyEx
                               FailedEx
                               InvalidArgsEx
                               NotConfiguredEx
                               NotConnectedEx
                               NotFoundEx
                               ServiceSetOverlapEx
        '''
        self._iface.ConnectHiddenNetwork(name,
                               dbus_interface=IWD_STATION_INTERFACE,
                               reply_handler=self._success,
                               error_handler=self._failure)
        self._wait_for_async_op()

    def start_adhoc(self, ssid, psk=None):
        self._prop_proxy.Set(IWD_DEVICE_INTERFACE, 'Mode', 'ad-hoc')
        self._adhoc_iface = dbus.Interface(self._bus.get_object(IWD_SERVICE,
                                            self.device_path),
                                            IWD_ADHOC_INTERFACE)
        if not psk:
            self._adhoc_iface.StartOpen(ssid, reply_handler=self._success,
                                        error_handler=self._failure)
        else:
            self._adhoc_iface.Start(ssid, psk, reply_handler=self._success,
                                        error_handler=self._failure)
        self._wait_for_async_op()

    def stop_adhoc(self):
        self._prop_proxy.Set(IWD_DEVICE_INTERFACE, 'Mode', 'station')

    def adhoc_wait_for_disconnected(self, addr):
        props = self._prop_proxy.GetAll(IWD_ADHOC_INTERFACE)
        if props.get('ConnectedPeers', None):
            if addr not in props['ConnectedPeers']:
                return

        self._adhoc_prop_found = False
        self._adhoc_timed_out = False

        def wait_timeout_cb():
            self._adhoc_timed_out = True
            return False

        def adhoc_props_changed(iface, changed, invalid):
            if changed.get('ConnectedPeers', None):
                if addr not in changed['ConnectedPeers']:
                    self._adhoc_prop_found = True

        self._prop_proxy.connect_to_signal('PropertiesChanged',
                                            adhoc_props_changed)

        GLib.timeout_add(int(30 * 1000), wait_timeout_cb)
        context = mainloop.get_context()
        while not self._adhoc_prop_found:
            context.iteration(may_block=True)
            if self._adhoc_timed_out:
                raise TimeoutError("Timed out waiting for peer %s" % addr)

    def adhoc_wait_for_connected(self, addr):
        props = self._prop_proxy.GetAll(IWD_ADHOC_INTERFACE)
        if props.get('ConnectedPeers', None):
            if addr in props['ConnectedPeers']:
                return

        self._adhoc_prop_found = False
        self._adhoc_timed_out = False

        def wait_timeout_cb():
            self._adhoc_timed_out = True
            return False

        def adhoc_props_changed(iface, changed, invalid):
            if changed.get('ConnectedPeers', None):
                if addr in changed['ConnectedPeers']:
                    self._adhoc_prop_found = True

        self._prop_proxy.connect_to_signal('PropertiesChanged',
                                            adhoc_props_changed)

        GLib.timeout_add(int(15 * 1000), wait_timeout_cb)
        context = mainloop.get_context()
        while not self._adhoc_prop_found:
            context.iteration(may_block=True)
            if self._adhoc_timed_out:
                raise TimeoutError("Timed out waiting for peer %s" % addr)

    def wait_for_connected(self):
        if str(self.state) == "connected":
            return

        self._connected_success = False
        self._connected_timed_out = False

        def wait_timeout_cb():
            self._connected_timed_out = True
            return False

        def connected_prop_changed(iface, changed, invalid):
            if changed.get('State', None):
                if changed['State'] == 'connected':
                    self._connected_success = True

        self._prop_proxy.connect_to_signal('PropertiesChanged',
                                            connected_prop_changed)
        GLib.timeout_add(int(15 * 1000), wait_timeout_cb)
        context = mainloop.get_context()
        while not self._connected_success:
            context.iteration(may_block=True)
            if self._connected_timed_out:
                raise TimeoutError("Timed out waiting for connected")

    def __str__(self, prefix = ''):
        return prefix + 'Device: ' + self.device_path + '\n'\
               + prefix + '\tName:\t\t' + self.name + '\n'\
               + prefix + '\tAddress:\t' + self.address + '\n'\
               + prefix + '\tState:\t\t' + str(self.state) + '\n'\
               + prefix + '\tPowered:\t' + str(self.powered) + '\n'\
               + prefix + '\tConnected net:\t' + str(self.connected_network) +\
                                                                            '\n'


class Network(IWDDBusAbstract):
    '''Class represents a network object: net.connman.iwd.Network'''
    _iface_name = IWD_NETWORK_INTERFACE

    @property
    def name(self):
        '''
            Network SSID.

            @rtype: string
        '''
        return self._properties['Name']

    @property
    def connected(self):
        '''
            Reflects whether the device is connected to this network.

            @rtype: boolean
        '''
        return bool(self._properties['Connected'])

    def connect(self, wait=True):
        '''
            Connect to the network. Request the device implied by the object
            path to connect to specified network.

			Possible exception: AbortedEx
                                BusyEx
                                FailedEx
                                NoAgentEx
                                NotSupportedEx
                                TimeoutEx

            @rtype: void
        '''

        self._iface.Connect(dbus_interface=self._iface_name,
                            reply_handler=self._success,
                            error_handler=self._failure)

        if wait:
            self._wait_for_async_op()

    def __str__(self, prefix = ''):
        return prefix + 'Network:\n' \
                + prefix + '\tName:\t' + self.name + '\n' \
                + prefix + '\tConnected:\t' + str(self.connected)


class KnownNetwork(IWDDBusAbstract):
    '''Class represents a known network object: net.connman.iwd.KnownNetwork'''
    _iface_name = IWD_KNOWN_NETWORK_INTERFACE

    def forget(self):
        '''
        Removes information saved by IWD about this network
        causing it to be treated as if IWD had never connected
        to it before.
        '''
        self._iface.Forget(dbus_interface=self._iface_name,
                               reply_handler=self._success,
                               error_handler=self._failure)
        self._wait_for_async_op()

    @property
    def name(self):
        '''Contains the Name (SSID) of the network.'''
        return str(self._properties['Name'])

    @property
    def type(self):
        '''Contains the type of the network.'''
        return NetworkType(self._properties['Type'])

    @property
    def last_connected_time(self):
        '''
        Contains the last time this network has been connected to.
        If the network is known, but has never been successfully
        connected to, this attribute is set to None.

        @rtype: datetime
        '''
        if 'LastConnectedTime' not in self._properties:
            return None

        val = self._properties['LastConnectedTime']
        return datetime.datetime.strptime(val, "%Y-%m-%dT%H:%M:%SZ")

    def __str__(self, prefix = ''):
        return prefix + 'Known Network:\n' \
                + prefix + '\tName:\t' + self.name + '\n' \
                + prefix + '\tType:\t' + str(self.type) + '\n' \
                + prefix + '\tLast connected:\t' + str(self.last_connected_time)

class OrderedNetwork(object):
    '''Represents a network found in the scan'''

    def __init__(self, o_n_tuple):
        self._network_object = Network(o_n_tuple[0])
        self._name = o_n_tuple[1]
        self._signal_strength = o_n_tuple[2]
        self._type = NetworkType.from_string(o_n_tuple[3])

    @property
    def network_object(self):
        '''
            net.connman.iwd.Network object representing the network.

            @rtype: Network
        '''
        return self._network_object

    @property
    def name(self):
        '''
            Device's interface name.

            @rtype: string
        '''
        return self._name

    @property
    def signal_strength(self):
        '''
            Network's maximum signal strength expressed in 100 * dBm.
            The value is the range of 0 (strongest signal) to
            -10000 (weakest signal)

            @rtype: number
        '''
        return self._signal_strength

    @property
    def type(self):
        '''
            Contains the type of the network.

            @rtype: NetworkType
        '''
        return self._type

    def __str__(self):
        return 'Ordered Network:\n'\
                '\tName:\t\t' + self.name + '\n'\
                '\tNetwork Type:\t' + str(self.type) + '\n'\
                '\tSignal Strength:'\
                    + ('None' if self.signal_strength is None else\
                        str(self.signal_strength)) + '\n'\
                '\tObject: \n' + self.network_object.__str__('\t\t')


class PSKAgent(dbus.service.Object):

    def __init__(self, passphrases=[], users=[]):
        if type(passphrases) != list:
            passphrases = [passphrases]
        self.passphrases = passphrases
        if type(users) != list:
            users = [users]
        self.users = users
        self._path = '/test/agent/' + str(int(round(time.time() * 1000)))

        dbus.service.Object.__init__(self, dbus.SystemBus(), self._path)

    @property
    def path(self):
        return self._path

    @dbus.service.method(IWD_AGENT_INTERFACE, in_signature='', out_signature='')
    def Release(self):
        print("Agent released")

    @dbus.service.method(IWD_AGENT_INTERFACE, in_signature='s',
                                                               out_signature='')
    def Cancel(self, reason):
        print("Cancel: " + reason)


    @dbus.service.method(IWD_AGENT_INTERFACE, in_signature='o',
                                                              out_signature='s')
    def RequestPassphrase(self, path):
        print('Requested PSK for ' + path)

        if not self.passphrases:
            raise CanceledEx("canceled")

        return self.passphrases.pop(0)

    @dbus.service.method(IWD_AGENT_INTERFACE, in_signature='o',
                                                              out_signature='s')
    def RequestPrivateKeyPassphrase(self, path):
        print('Requested private-key passphrase for ' + path)

        if not self.passphrases:
            raise CanceledEx("canceled")

        return self.passphrases.pop(0)

    @dbus.service.method(IWD_AGENT_INTERFACE, in_signature='o',
                                                             out_signature='ss')
    def RequestUserNameAndPassword(self, path):
        print('Requested the user name and password for ' + path)

        if not self.users:
            raise CanceledEx("canceled")

        return self.users.pop(0)

    @dbus.service.method(IWD_AGENT_INTERFACE, in_signature='os',
                                                              out_signature='s')
    def RequestUserPassword(self, path, req_user):
        print('Requested the password for ' + path + ' for user ' + req_user)

        if not self.users:
            raise CanceledEx("canceled")

        user, passwd = self.users.pop(0)
        if user != req_user:
            raise CanceledEx("canceled")

        return passwd


class DeviceList(collections.Mapping):
    def __init__(self, iwd):
        self._dict = {}

        iwd._object_manager.connect_to_signal("InterfacesAdded",
                                               self._interfaces_added_handler)
        iwd._object_manager.connect_to_signal("InterfacesRemoved",
                                               self._interfaces_removed_handler)

        objects = iwd._object_manager.GetManagedObjects()

        for path in objects:
            for interface in objects[path]:
                if interface == IWD_DEVICE_INTERFACE:
                    self._dict[path] = Device(path, objects[path][interface])

    def __getitem__(self, key):
        return self._dict.__getitem__(key)

    def __iter__(self):
        return self._dict.__iter__()

    def __len__(self):
        return self._dict.__len__()

    def __delitem__(self, key):
        self._dict.pop(key).remove()

    def _interfaces_added_handler(self, path, interfaces):
        if IWD_DEVICE_INTERFACE in interfaces:
            self._dict[path] = Device(path, interfaces[IWD_DEVICE_INTERFACE])

    def _interfaces_removed_handler(self, path, interfaces):
        if IWD_DEVICE_INTERFACE in interfaces:
            del self._dict[path]


class IWD(AsyncOpAbstract):
    ''''''
    _bus = dbus.SystemBus()

    _object_manager_if = None
    _agent_manager_if = None
    _iwd_proc = None
    _devices = None

    def __init__(self, start_iwd_daemon = False,
                                               iwd_config_dir = IWD_CONFIG_DIR):
        global mainloop
        mainloop = GLib.MainLoop()

        if start_iwd_daemon:
            args = []
            iwd_wiphys = [wname for wname, wiphy in wiphy.wiphy_map.items()
                          if any(intf for intf in wiphy.values()
                                 if intf.use == 'iwd')]
            whitelist = ','.join(iwd_wiphys)

            if os.environ.get('IWD_TEST_VALGRIND', None) == 'on':
                    args.append('valgrind')
                    args.append('--leak-check=full')

            args.append('iwd')
            args.append('-c')
            args.append(iwd_config_dir)
            args.append('-p')
            args.append(whitelist)
            args.append('-d')

            import subprocess
            iwd_proc = subprocess.Popen(args)

            self._iwd_proc = iwd_proc

        tries = 0
        while not self._bus.name_has_owner(IWD_SERVICE):
            if os.environ['IWD_TEST_TIMEOUTS'] == 'on':
                if tries > 100:
                    if start_iwd_daemon:
                        iwd_proc.terminate()
                    raise TimeoutError('IWD has failed to start')
                tries += 1
            time.sleep(0.1)

        self._devices = DeviceList(self)

    def __del__(self):
        if self._iwd_proc is None:
            return

        self._object_manager_if = None
        self._agent_manager_if = None
        self._known_networks = None
        self._devices = None

        self._iwd_proc.terminate()
        self._iwd_proc.wait()

        self._iwd_proc = None

    @property
    def _object_manager(self):
        if self._object_manager_if is None:
            self._object_manager_if = \
                       dbus.Interface(self._bus.get_object(IWD_SERVICE,
                                                           IWD_TOP_LEVEL_PATH),
                                      DBUS_OBJECT_MANAGER)
        return self._object_manager_if

    @property
    def _agent_manager(self):
        if self._agent_manager_if is None:
            self._agent_manager_if =\
                dbus.Interface(self._bus.get_object(IWD_SERVICE,
                                                    IWD_AGENT_MANAGER_PATH),
                               IWD_AGENT_MANAGER_INTERFACE)
        return self._agent_manager_if

    def wait_for_object_condition(self, obj, condition_str, max_wait = 15):
        self._wait_timed_out = False
        def wait_timeout_cb():
            self._wait_timed_out = True
            return False

        timeout = GLib.timeout_add_seconds(max_wait, wait_timeout_cb)
        context = mainloop.get_context()
        while not eval(condition_str):
            context.iteration(may_block=True)
            if self._wait_timed_out and os.environ['IWD_TEST_TIMEOUTS'] == 'on':
                raise TimeoutError('[' + condition_str + ']'\
                                   ' condition was not met in '\
                                   + str(max_wait) + ' sec')
        GLib.source_remove(timeout)

    def wait(self, time):
        self._wait_timed_out = False
        def wait_timeout_cb():
            self._wait_timed_out = True
            return False

        GLib.timeout_add(int(time * 1000), wait_timeout_cb)
        context = mainloop.get_context()
        while not self._wait_timed_out:
            context.iteration(may_block=True)

    @staticmethod
    def clear_storage():
        os.system('rm -rf ' + IWD_STORAGE_DIR + '/*')

    @staticmethod
    def create_in_storage(file_name, file_content):
        fo = open(IWD_STORAGE_DIR + '/' + file_name, 'w')

        fo.write(file_content);
        fo.close()

    @staticmethod
    def copy_to_storage(source):
        import shutil

        assert not os.path.isabs(source)
        shutil.copy(source, IWD_STORAGE_DIR)

    @staticmethod
    def remove_from_storage(file_name):
        os.system('rm -rf ' + IWD_STORAGE_DIR + '/\'' + file_name + '\'')

    def list_devices(self, wait_to_appear = 0, max_wait = 15):
        if not wait_to_appear:
            return list(self._devices.values())

        self._wait_timed_out = False
        def wait_timeout_cb():
            self._wait_timed_out = True
            return False

        timeout = GLib.timeout_add_seconds(max_wait, wait_timeout_cb)
        context = mainloop.get_context()
        while len(self._devices) < wait_to_appear:
            context.iteration(may_block=True)
            if self._wait_timed_out:
                raise TimeoutError('IWD has no associated devices')

        GLib.source_remove(timeout)

        return list(self._devices.values())

    def list_known_networks(self):
        '''Returns the list of KnownNetwork objects.'''
        objects = self._object_manager.GetManagedObjects()
        known_network_list = []

        for path in objects:
            for interface in objects[path]:
                if interface == IWD_KNOWN_NETWORK_INTERFACE:
                    known_network_list.append(
                            KnownNetwork(path, objects[path][interface]))

        return known_network_list

    def register_psk_agent(self, psk_agent):
        self._agent_manager.RegisterAgent(
                                     psk_agent.path,
                                     dbus_interface=IWD_AGENT_MANAGER_INTERFACE,
                                     reply_handler=self._success,
                                     error_handler=self._failure)
        self._wait_for_async_op()

    def unregister_psk_agent(self, psk_agent):
        self._agent_manager.UnregisterAgent(
                                     psk_agent.path,
                                     dbus_interface=IWD_AGENT_MANAGER_INTERFACE,
                                     reply_handler=self._success,
                                     error_handler=self._failure)
        self._wait_for_async_op()