bluez_components.py

'''
These classes and functions were taken from the example-advertisement.py and example-gatt-server.py scripts
of the BlueZ project. They were grouped together in this file to simplify the usage of BlueZ's D-Bus API.
It allows us to register our own GATT services and to advertise them.
For more information about BlueZ visit http://www.bluez.org/
'''

import dbus.exceptions
import dbus.service

BLUEZ_SERVICE_NAME = 'org.bluez'
GATT_MANAGER_IFACE = 'org.bluez.GattManager1'
LE_ADVERTISING_MANAGER_IFACE = 'org.bluez.LEAdvertisingManager1'

DBUS_OM_IFACE = 'org.freedesktop.DBus.ObjectManager'
DBUS_PROP_IFACE = 'org.freedesktop.DBus.Properties'

GATT_SERVICE_IFACE = 'org.bluez.GattService1'
GATT_CHRC_IFACE = 'org.bluez.GattCharacteristic1'
GATT_DESC_IFACE = 'org.bluez.GattDescriptor1'

LE_ADVERTISEMENT_IFACE = 'org.bluez.LEAdvertisement1'


class InvalidArgsException(dbus.exceptions.DBusException):
    _dbus_error_name = 'org.freedesktop.DBus.Error.InvalidArgs'


class NotSupportedException(dbus.exceptions.DBusException):
    _dbus_error_name = 'org.bluez.Error.NotSupported'


class NotPermittedException(dbus.exceptions.DBusException):
    _dbus_error_name = 'org.bluez.Error.NotPermitted'


class InvalidValueLengthException(dbus.exceptions.DBusException):
    _dbus_error_name = 'org.bluez.Error.InvalidValueLength'


class FailedException(dbus.exceptions.DBusException):
    _dbus_error_name = 'org.bluez.Error.Failed'


class Application(dbus.service.Object):
    def __init__(self, bus):
        self.path = '/'
        self.services = []
        dbus.service.Object.__init__(self, bus, self.path)

    def get_path(self):
        return dbus.ObjectPath(self.path)

    def add_service(self, service):
        self.services.append(service)

    @dbus.service.method(DBUS_OM_IFACE, out_signature='a{oa{sa{sv}}}')
    def GetManagedObjects(self):
        response = {}
        print('GetManagedObjects')

        for service in self.services:
            response[service.get_path()] = service.get_properties()
            chrcs = service.get_characteristics()
            for chrc in chrcs:
                response[chrc.get_path()] = chrc.get_properties()
                descs = chrc.get_descriptors()
                for desc in descs:
                    response[desc.get_path()] = desc.get_properties()

        return response


class Service(dbus.service.Object):
    PATH_BASE = '/org/bluez/example/service'

    def __init__(self, bus, index, uuid, primary):
        self.path = self.PATH_BASE + str(index)
        self.bus = bus
        self.uuid = uuid
        self.primary = primary
        self.characteristics = []
        dbus.service.Object.__init__(self, bus, self.path)

    def get_properties(self):
        return {
            GATT_SERVICE_IFACE: {
                'UUID': self.uuid,
                'Primary': self.primary,
                'Characteristics': dbus.Array(
                    self.get_characteristic_paths(),
                    signature='o')
            }
        }

    def get_path(self):
        return dbus.ObjectPath(self.path)

    def add_characteristic(self, characteristic):
        self.characteristics.append(characteristic)

    def get_characteristic_paths(self):
        result = []
        for chrc in self.characteristics:
            result.append(chrc.get_path())
        return result

    def get_characteristics(self):
        return self.characteristics

    @dbus.service.method(DBUS_PROP_IFACE,
                         in_signature='s',
                         out_signature='a{sv}')
    def GetAll(self, interface):
        if interface != GATT_SERVICE_IFACE:
            raise InvalidArgsException()

        return self.get_properties()[GATT_SERVICE_IFACE]


class Characteristic(dbus.service.Object):
    def __init__(self, bus, index, uuid, flags, service):
        self.path = service.path + '/char' + str(index)
        self.bus = bus
        self.uuid = uuid
        self.service = service
        self.flags = flags
        self.descriptors = []
        dbus.service.Object.__init__(self, bus, self.path)

    def get_properties(self):
        return {
            GATT_CHRC_IFACE: {
                'Service': self.service.get_path(),
                'UUID': self.uuid,
                'Flags': self.flags,
                'Descriptors': dbus.Array(
                    self.get_descriptor_paths(),
                    signature='o')
            }
        }

    def get_path(self):
        return dbus.ObjectPath(self.path)

    def add_descriptor(self, descriptor):
        self.descriptors.append(descriptor)

    def get_descriptor_paths(self):
        result = []
        for desc in self.descriptors:
            result.append(desc.get_path())
        return result

    def get_descriptors(self):
        return self.descriptors

    @dbus.service.method(DBUS_PROP_IFACE,
                         in_signature='s',
                         out_signature='a{sv}')
    def GetAll(self, interface):
        if interface != GATT_CHRC_IFACE:
            raise InvalidArgsException()

        return self.get_properties()[GATT_CHRC_IFACE]

    @dbus.service.method(GATT_CHRC_IFACE,
                         in_signature='a{sv}',
                         out_signature='ay')
    def ReadValue(self, options):
        print('Default ReadValue called, returning error')
        raise NotSupportedException()

    @dbus.service.method(GATT_CHRC_IFACE, in_signature='aya{sv}')
    def WriteValue(self, value, options):
        print('Default WriteValue called, returning error')
        raise NotSupportedException()

    @dbus.service.method(GATT_CHRC_IFACE)
    def StartNotify(self):
        print('Default StartNotify called, returning error')
        raise NotSupportedException()

    @dbus.service.method(GATT_CHRC_IFACE)
    def StopNotify(self):
        print('Default StopNotify called, returning error')
        raise NotSupportedException()

    @dbus.service.signal(DBUS_PROP_IFACE,
                         signature='sa{sv}as')
    def PropertiesChanged(self, interface, changed, invalidated):
        pass


class Descriptor(dbus.service.Object):
    def __init__(self, bus, index, uuid, flags, characteristic):
        self.path = characteristic.path + '/desc' + str(index)
        self.bus = bus
        self.uuid = uuid
        self.flags = flags
        self.chrc = characteristic
        dbus.service.Object.__init__(self, bus, self.path)

    def get_properties(self):
        return {
            GATT_DESC_IFACE: {
                'Characteristic': self.chrc.get_path(),
                'UUID': self.uuid,
                'Flags': self.flags,
            }
        }

    def get_path(self):
        return dbus.ObjectPath(self.path)

    @dbus.service.method(DBUS_PROP_IFACE,
                         in_signature='s',
                         out_signature='a{sv}')
    def GetAll(self, interface):
        if interface != GATT_DESC_IFACE:
            raise InvalidArgsException()

        return self.get_properties()[GATT_CHRC_IFACE]

    @dbus.service.method(GATT_DESC_IFACE,
                         in_signature='a{sv}',
                         out_signature='ay')
    def ReadValue(self, options):
        print('Default ReadValue called, returning error')
        raise NotSupportedException()

    @dbus.service.method(GATT_DESC_IFACE, in_signature='aya{sv}')
    def WriteValue(self, value, options):
        print('Default WriteValue called, returning error')
        raise NotSupportedException()


class Advertisement(dbus.service.Object):
    PATH_BASE = '/org/bluez/example/advertisement'

    def __init__(self, bus, index, advertising_type):
        self.path = self.PATH_BASE + str(index)
        self.bus = bus
        self.ad_type = advertising_type
        self.service_uuids = None
        self.manufacturer_data = None
        self.solicit_uuids = None
        self.service_data = None
        self.include_tx_power = None
        dbus.service.Object.__init__(self, bus, self.path)

    def get_properties(self):
        properties = dict()
        properties['Type'] = self.ad_type
        if self.service_uuids is not None:
            properties['ServiceUUIDs'] = dbus.Array(self.service_uuids,
                                                    signature='s')
        if self.solicit_uuids is not None:
            properties['SolicitUUIDs'] = dbus.Array(self.solicit_uuids,
                                                    signature='s')
        if self.manufacturer_data is not None:
            properties['ManufacturerData'] = dbus.Dictionary(
                self.manufacturer_data, signature='qay')
        if self.service_data is not None:
            properties['ServiceData'] = dbus.Dictionary(self.service_data,
                                                        signature='say')
        if self.include_tx_power is not None:
            properties['IncludeTxPower'] = dbus.Boolean(self.include_tx_power)
        return {LE_ADVERTISEMENT_IFACE: properties}

    def get_path(self):
        return dbus.ObjectPath(self.path)

    def add_service_uuid(self, uuid):
        if not self.service_uuids:
            self.service_uuids = []
        self.service_uuids.append(uuid)

    def add_solicit_uuid(self, uuid):
        if not self.solicit_uuids:
            self.solicit_uuids = []
        self.solicit_uuids.append(uuid)

    def add_manufacturer_data(self, manuf_code, data):
        if not self.manufacturer_data:
            self.manufacturer_data = dict()
        self.manufacturer_data[manuf_code] = data

    def add_service_data(self, uuid, data):
        if not self.service_data:
            self.service_data = dict()
        self.service_data[uuid] = data

    @dbus.service.method(DBUS_PROP_IFACE,
                         in_signature='s',
                         out_signature='a{sv}')
    def GetAll(self, interface):
        print('GetAll')
        if interface != LE_ADVERTISEMENT_IFACE:
            raise InvalidArgsException()
        print('returning props')
        return self.get_properties()[LE_ADVERTISEMENT_IFACE]

    @dbus.service.method(LE_ADVERTISEMENT_IFACE,
                         in_signature='',
                         out_signature='')
    def Release(self):
        print('%s: Released!' % self.path)


def find_adapter_gattmanager(bus):
    remote_om = dbus.Interface(bus.get_object(BLUEZ_SERVICE_NAME, '/'),
                               DBUS_OM_IFACE)
    objects = remote_om.GetManagedObjects()

    for o, props in objects.items():
        if GATT_MANAGER_IFACE in props.keys():
            return o

    return None


def find_adapter_advertisingmanager(bus):
    remote_om = dbus.Interface(bus.get_object(BLUEZ_SERVICE_NAME, '/'),
                               DBUS_OM_IFACE)
    objects = remote_om.GetManagedObjects()

    for o, props in objects.items():
        if LE_ADVERTISING_MANAGER_IFACE in props:
            return o

    return None


def get_service_manager(bus):
    # Get the GattManager
    adapter_gattmanager = find_adapter_gattmanager(bus)
    if not adapter_gattmanager:
        print('GattManager1 interface not found')
        return

    service_manager = dbus.Interface(
        bus.get_object(BLUEZ_SERVICE_NAME, adapter_gattmanager),
        GATT_MANAGER_IFACE)

    return service_manager


def get_ad_manager(bus):
    # Get the AdapterManager
    adapter_advertisingmanager = find_adapter_advertisingmanager(bus)
    if not adapter_advertisingmanager:
        print('LEAdvertisingManager1 interface not found')
        return

    adapter_props = dbus.Interface(bus.get_object(BLUEZ_SERVICE_NAME, adapter_advertisingmanager),
                                   "org.freedesktop.DBus.Properties")

    adapter_props.Set("org.bluez.Adapter1", "Powered", dbus.Boolean(1))

    ad_manager = dbus.Interface(bus.get_object(BLUEZ_SERVICE_NAME, adapter_advertisingmanager),
                                LE_ADVERTISING_MANAGER_IFACE)

    return ad_manager