path: root/services/presence/Service.py

# Copyright (C) 2006, Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

import avahi
import sys, os
sys.path.insert(0, os.path.abspath("../../"))
from sugar import util
import dbus, dbus.service
import random
import logging
import gobject

def compose_service_name(name, activity_id):
    if isinstance(name, str):
        name = unicode(name)
    if not name:
        raise ValueError("name must be a valid string.")
    if not activity_id:
        return name
    if not isinstance(name, unicode):
        raise ValueError("name must be in unicode.")
    composed = "%s [%s]" % (name, activity_id)
    return composed

def decompose_service_name(name):
    """Break a service name into the name and activity ID, if we can."""
    if not isinstance(name, unicode):
        raise ValueError("name must be a valid unicode string.")
    name_len = len(name)
    if name_len < util.ACTIVITY_ID_LEN + 5:
        return (None, name)
    # check for activity id end marker
    if name[name_len - 1] != "]":
        return (None, name)
    start = name_len - 1 - util.ACTIVITY_ID_LEN
    end = name_len - 1
    # check for activity id start marker
    if name[start - 1] != "[" or name[start - 2] != " ":
        return (None, name)
    activity_id = name[start:end]
    if not util.validate_activity_id(activity_id):
        return (None, name)
    return (activity_id, name[:start - 2])

def _one_dict_differs(dict1, dict2):
    diff_keys = []
    for key, value in dict1.items():
        if not dict2.has_key(key) or dict2[key] != value:
            diff_keys.append(key)
    return diff_keys

def _dicts_differ(dict1, dict2):
    diff_keys = []
    diff1 = _one_dict_differs(dict1, dict2)
    diff2 = _one_dict_differs(dict2, dict1)
    for key in diff2:
        if key not in diff1:
            diff_keys.append(key)
    diff_keys += diff1
    return diff_keys

def _convert_properties_to_dbus_byte_array(props):
    # Ensure properties are converted to ByteArray types
    # because python sometimes can't figure that out
    info = dbus.Array([], signature="aay")
    for k, v in props.items():
        info.append(dbus.types.ByteArray("%s=%s" % (k, v)))
    return info


_ACTIVITY_ID_TAG = "ActivityID"
SERVICE_DBUS_INTERFACE = "org.laptop.Presence.Service"
SERVICE_DBUS_OBJECT_PATH = "/org/laptop/Presence/Services/"

class ServiceDBusHelper(dbus.service.Object):
    """Handle dbus requests and signals for Service objects"""
    def __init__(self, parent, bus_name, object_path):
        self._parent = parent
        self._bus_name = bus_name
        self._object_path = object_path
        dbus.service.Object.__init__(self, bus_name, self._object_path)

    @dbus.service.signal(SERVICE_DBUS_INTERFACE,
                        signature="as")
    def PublishedValueChanged(self, keylist):
        pass

    @dbus.service.method(SERVICE_DBUS_INTERFACE,
                        in_signature="", out_signature="a{sv}")
    def getProperties(self):
        """Return service properties."""
        pary = {}
        pary['name'] = self._parent.get_name()
        pary['type'] = self._parent.get_type()
        pary['domain'] = self._parent.get_domain()
        actid = self._parent.get_activity_id()
        if actid:
            pary['activityId'] = actid
        port = self._parent.get_port()
        if port:
            pary['port'] = self._parent.get_port()
        addr = self._parent.get_address()
        if addr:
            pary['address'] = addr
        source_addr = self._parent.get_source_address()
        if source_addr:
            pary['sourceAddress'] = source_addr
        return pary

    @dbus.service.method(SERVICE_DBUS_INTERFACE,
                        in_signature="s")
    def getPublishedValue(self, key):
        """Return the value belonging to the requested key from the
        service's TXT records."""
        val = self._parent.get_one_property(key)
        if not val:
            raise KeyError("Value was not found.")
        return val

    @dbus.service.method(SERVICE_DBUS_INTERFACE,
                        in_signature="", out_signature="a{sv}")
    def getPublishedValues(self):
        pary = {}
        props = self._parent.get_properties()
        for key, value in props.items():
            pary[key] = str(value)
        return dbus.Dictionary(pary)

    @dbus.service.method(SERVICE_DBUS_INTERFACE,
                        sender_keyword="sender")
    def setPublishedValue(self, key, value, sender):
        self._parent.set_property(key, value, sender)

    @dbus.service.method(SERVICE_DBUS_INTERFACE,
                        in_signature="a{sv}", sender_keyword="sender")
    def setPublishedValues(self, values, sender):
        if not self._parent.is_local():
            raise ValueError("Service was not not registered by requesting process!")        
        self._parent.set_properties(values, sender)


class Service(gobject.GObject):
    """Encapsulates information about a specific ZeroConf/mDNS
    service as advertised on the network."""

    __gsignals__ = {
        'property-changed': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE,
                         ([gobject.TYPE_PYOBJECT]))
    }

    def __init__(self, bus_name, object_id, name, stype, domain=u"local",
                address=None, port=-1, properties=None, source_address=None,
                local_publisher=None):
        gobject.GObject.__init__(self)
        if not bus_name:
            raise ValueError("DBus bus name must be valid")
        if not object_id or not isinstance(object_id, int):
            raise ValueError("object id must be a valid number")

        # Validate immutable options
        if name and not isinstance(name, unicode):
            raise ValueError("name must be unicode.")
        if not name or not len(name):
            raise ValueError("must specify a valid service name.")

        if stype and not isinstance(stype, unicode):
            raise ValueError("service type must be in unicode.")
        if not stype or not len(stype):
            raise ValueError("must specify a valid service type.")
        if not stype.endswith("._tcp") and not stype.endswith("._udp"):
            raise ValueError("must specify a TCP or UDP service type.")

        if not isinstance(domain, unicode):
            raise ValueError("domain must be in unicode.")
        if domain and domain != "local":
            raise ValueError("must use the 'local' domain (for now).")

        # ID of the D-Bus connection that published this service, if any.
        # We only let the local publisher modify the service.
        self._local_publisher = local_publisher

        self._avahi_entry_group = None

        (actid, real_name) = decompose_service_name(name)
        self._name = real_name
        self._full_name = name
        self._stype = stype
        self._domain = domain
        self._port = -1
        self.set_port(port)
        self._properties = {}
        self._dbus_helper = None
        self._internal_set_properties(properties)

        # Source address is the unicast source IP
        self._source_address = None
        if source_address is not None:
            self.set_source_address(source_address)

        # Address is the published address, could be multicast or unicast
        self._address = None
        if self._properties.has_key('address'):
            self.set_address(self._properties['address'])
        elif address is not None:
            self.set_address(address)
            self._properties['address'] = address

        # Ensure that an ActivityID tag, if given, matches
        # what we expect from the service type
        if self._properties.has_key(_ACTIVITY_ID_TAG):
            prop_actid = self._properties[_ACTIVITY_ID_TAG]
            if (prop_actid and not actid) or (prop_actid != actid):
                raise ValueError("ActivityID property specified, but the " \
                        "service names's activity ID didn't match it: %s," \
                        " %s" % (prop_actid, actid))
        self._activity_id = actid
        if actid and not self._properties.has_key(_ACTIVITY_ID_TAG):
            self._properties[_ACTIVITY_ID_TAG] = actid

        self._owner = None

        # register ourselves with dbus
        self._object_id = object_id
        self._object_path = SERVICE_DBUS_OBJECT_PATH + str(self._object_id)
        self._dbus_helper = ServiceDBusHelper(self, bus_name, self._object_path)

    def object_path(self):
        return dbus.ObjectPath(self._object_path)

    def get_owner(self):
        return self._owner

    def set_owner(self, owner):
        if self._owner is not None:
            raise RuntimeError("Can only set a service's owner once")
        self._owner = owner

    def is_local(self):
        if self._local_publisher is not None:
            return True
        return False

    def get_name(self):
        """Return the service's name, usually that of the
        buddy who provides it."""
        return self._name

    def get_full_name(self):
        return self._full_name

    def get_one_property(self, key):
        """Return one property of the service, or None
        if the property was not found.  Cannot distinguish
        between lack of a property, and a property value that
        actually is None."""
        if key in self._properties.keys():
            return self._properties[key]
        return None

    def get_properties(self):
        """Return a python dictionary of all the service's
        properties."""
        return self._properties

    def __emit_properties_changed_signal(self, keys):
        if self._dbus_helper:
            self._dbus_helper.PublishedValueChanged(keys)
        self.emit('property-changed', keys)

    def set_property(self, key, value, sender=None):
        """Set one service property"""
        if not self._local_publisher:
            raise ValueError("Service was not not registered by requesting process!")        
        if sender is not None and self._local_publisher != sender:
            raise ValueError("Service was not not registered by requesting process!")

        if not isinstance(key, unicode):
            raise ValueError("Key must be a unicode string.")
        if not isinstance(value, unicode) and not isinstance(value, bool):
            raise ValueError("Key must be a unicode string or a boolean.")

        # Ignore setting the key to it's current value
        if self._properties.has_key(key):
            if self._properties[key] == value:
                return

        # Blank value means remove key
        remove = False
        if isinstance(value, unicode) and len(value) == 0:
            remove = True
        if isinstance(value, bool) and value == False:
            remove = True

        if remove:
            # If the key wasn't present, return without error
            if self._properties.has_key(key):
                del self._properties[key]
        else:
            # Otherwise set it
            if isinstance(value, bool):
                value = ""
            self._properties[key] = value

        # if the service is locally published already, update the TXT records
        if self._local_publisher and self._avahi_entry_group:
            self.__internal_update_avahi_properties()

        self.__emit_properties_changed_signal([key])

    def set_properties(self, properties, sender=None, from_network=False):
        """Set all service properties in one call"""
        if sender is not None and self._local_publisher != sender:
            raise ValueError("Service was not not registered by requesting process!")

        self._internal_set_properties(properties, from_network)

    def _internal_set_properties(self, properties, from_network=False):
        """Set the service's properties from either an Avahi
        TXT record (a list of lists of integers), or a
        python dictionary."""
        if not isinstance (properties, dict):
            raise ValueError("Properties must be a dictionary.")

        # Make sure the properties are actually different
        diff_keys = _dicts_differ(self._properties, properties)
        if len(diff_keys) == 0:
            return

        self._properties = {}
        # Set key/value pairs on internal property list
        for key, value in properties.items():
            if len(key) == 0:
                continue
            tmp_key = key
            tmp_val = value
            if not isinstance(tmp_key, unicode):
                tmp_key = unicode(tmp_key)
            if not isinstance(tmp_val, unicode):
                tmp_val = unicode(tmp_val)
            self._properties[tmp_key] = tmp_val

        # if the service is locally published already, update the TXT records
        if self._local_publisher and self._avahi_entry_group and not from_network:
            self.__internal_update_avahi_properties()

        self.__emit_properties_changed_signal(diff_keys)

    def __internal_update_avahi_properties(self):
        info = _convert_properties_to_dbus_byte_array(self._properties)
        self._avahi_entry_group.UpdateServiceTxt(avahi.IF_UNSPEC,
                avahi.PROTO_UNSPEC, 0,
                dbus.String(self._full_name), dbus.String(self._stype),
                dbus.String(self._domain), info)

    def get_type(self):
        """Return the service's service type."""
        return self._stype

    def get_activity_id(self):
        """Return the activity ID this service is associated with, if any."""
        return self._activity_id

    def get_port(self):
        return self._port

    def set_port(self, port):
        if not isinstance(port, int) or (port <= 1024 and port > 65536):
            raise ValueError("must specify a valid port number between 1024 and 65536.")
        self._port = port

    def get_source_address(self):
        return self._source_address

    def set_source_address(self, address):
        if not address or not isinstance(address, unicode):
            raise ValueError("address must be unicode")
        self._source_address = address

    def get_address(self):
        return self._address

    def set_address(self, address):
        if not address or not isinstance(address, unicode):
            raise ValueError("address must be a unicode string")
        self._address = address
        self._properties['address'] = address

    def get_domain(self):
        """Return the ZeroConf/mDNS domain the service was found in."""
        return self._domain

    def register(self, system_bus, avahi_service):
        if self._avahi_entry_group is not None:
            raise RuntimeError("Service already registered!")

        obj = system_bus.get_object(avahi.DBUS_NAME, avahi_service.EntryGroupNew())
        self._avahi_entry_group = dbus.Interface(obj, avahi.DBUS_INTERFACE_ENTRY_GROUP)

        info = _convert_properties_to_dbus_byte_array(self._properties)
        logging.debug("Will register service with name='%s', stype='%s'," \
                " domain='%s', address='%s', port=%d, info='%s'" % (self._full_name,
                self._stype, self._domain, self._address, self._port, info))

        self._avahi_entry_group.AddService(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, 0,
                dbus.String(self._full_name), dbus.String(self._stype),
                dbus.String(self._domain), dbus.String(""), # let Avahi figure the 'host' out
                dbus.UInt16(self._port), info)

        self._avahi_entry_group.connect_to_signal('StateChanged', self.__entry_group_changed_cb)
        self._avahi_entry_group.Commit()

    def __entry_group_changed_cb(self, state, error):
        pass
#        logging.debug("** %s.%s Entry group changed: state %s, error %s" % (self._full_name, self._stype, state, error))

    def unregister(self, sender):
        # Refuse to unregister if we can't get the dbus connection this request
        # came from for some reason
        if not sender:
            raise RuntimeError("Service registration request must have a sender.")
        if not self._local_publisher:
            raise ValueError("Service was not a local service provided by this laptop!")
        if sender is not None and self._local_publisher != sender:
            raise ValueError("Service was not registered by requesting process!")
        if not self._avahi_entry_group:
            raise ValueError("Service was not registered by requesting process!")
        self._avahi_entry_group.Free()
        del self._avahi_entry_group
        self._avahi_entry_group = None


#################################################################
# Tests
#################################################################

import unittest

__objid_seq = 0
def _next_objid():
    global __objid_seq
    __objid_seq = __objid_seq + 1
    return __objid_seq


class ServiceTestCase(unittest.TestCase):
    _DEF_NAME = u"foobar"
    _DEF_STYPE = u"_foo._bar._tcp"
    _DEF_DOMAIN = u"local"
    _DEF_ADDRESS = u"1.1.1.1"
    _DEF_PORT = 1234
    _DEF_PROPS = {'foobar': 'baz'}
    _STR_TEST_ARGS = [None, 0, [], {}]

    def __init__(self, name):
        self._bus = dbus.SessionBus()
        self._bus_name = dbus.service.BusName('org.laptop.Presence', bus=self._bus)        
        unittest.TestCase.__init__(self, name)

    def __del__(self):
        del self._bus_name
        del self._bus

    def _test_init_fail(self, name, stype, domain, address, port, properties, fail_msg):
        """Test something we expect to fail."""
        try:
            objid = _next_objid()
            service = Service(self._bus_name, objid, name, stype, domain, address,
                    port, properties)
        except ValueError, exc:
            pass
        else:
            self.fail("expected a ValueError for %s." % fail_msg)

    def testName(self):
        for item in self._STR_TEST_ARGS:
            self._test_init_fail(item, self._DEF_STYPE, self._DEF_DOMAIN, self._DEF_ADDRESS,
                    self._DEF_PORT, self._DEF_PROPS, "invalid name")

    def testType(self):
        for item in self._STR_TEST_ARGS:
            self._test_init_fail(self._DEF_NAME, item, self._DEF_DOMAIN, self._DEF_ADDRESS,
                    self._DEF_PORT, self._DEF_PROPS, "invalid service type")
        self._test_init_fail(self._DEF_NAME, u"_bork._foobar", self._DEF_DOMAIN, self._DEF_ADDRESS,
                self._DEF_PORT, self._DEF_PROPS, "invalid service type")

    def testDomain(self):
        for item in self._STR_TEST_ARGS:
            self._test_init_fail(self._DEF_NAME, self._DEF_STYPE, item, self._DEF_ADDRESS,
                    self._DEF_PORT, self._DEF_PROPS, "invalid domain")
        # Only accept local for now
        self._test_init_fail(self._DEF_NAME, self._DEF_STYPE, u"foobar", self._DEF_ADDRESS,
                self._DEF_PORT, self._DEF_PROPS, "invalid domain")
        # Make sure "" works
        objid = _next_objid()
        service = Service(self._bus_name, objid, self._DEF_NAME, self._DEF_STYPE, u"",
                self._DEF_ADDRESS, self._DEF_PORT, self._DEF_PROPS)
        assert service, "Empty domain was not accepted!"

    def testAddress(self):
        self._test_init_fail(self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN, [],
                self._DEF_PORT, self._DEF_PROPS, "invalid address")
        self._test_init_fail(self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN, {},
                self._DEF_PORT, self._DEF_PROPS, "invalid address")
        self._test_init_fail(self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN, 1234,
                self._DEF_PORT, self._DEF_PROPS, "invalid address")

    def testPort(self):
        self._test_init_fail(self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN, self._DEF_ADDRESS,
                [], self._DEF_PROPS, "invalid port")
        self._test_init_fail(self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN, self._DEF_ADDRESS,
                {}, self._DEF_PROPS, "invalid port")
        self._test_init_fail(self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN, self._DEF_ADDRESS,
                "adf", self._DEF_PROPS, "invalid port")

    def testGoodInit(self):
        objid = _next_objid()
        service = Service(self._bus_name, objid, self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN,
                self._DEF_ADDRESS, self._DEF_PORT, self._DEF_PROPS)
        assert service.get_name() == self._DEF_NAME, "service name wasn't correct after init."
        assert service.get_type() == self._DEF_STYPE, "service type wasn't correct after init."
        assert service.get_domain() == "local", "service domain wasn't correct after init."
        assert service.get_address() == self._DEF_ADDRESS, "service address wasn't correct after init."
        assert service.get_port() == self._DEF_PORT, "service port wasn't correct after init."
        assert service.object_path() == SERVICE_DBUS_OBJECT_PATH + str(objid)
        value = service.get_one_property('foobar')
        assert value and value == 'baz', "service property wasn't correct after init."

    def testAvahiProperties(self):
        props = [[111, 114, 103, 46, 102, 114, 101, 101, 100, 101, 115, 107, 116, 111, 112, 46, 65, 118, 97, 104, 105, 46, 99, 111, 111, 107, 105, 101, 61, 50, 54, 48, 49, 53, 52, 51, 57, 53, 50]]
        key = "org.freedesktop.Avahi.cookie"
        expected_value = "2601543952"
        objid = _next_objid()
        service = Service(self._bus_name, objid, self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN,
                self._DEF_ADDRESS, self._DEF_PORT, props)
        value = service.get_one_property(key)
        assert value and value == expected_value, "service properties weren't correct after init."
        value = service.get_one_property('bork')
        assert not value, "service properties weren't correct after init."

    def testBoolProperty(self):
        props = [[111, 114, 103, 46, 102, 114, 101, 101, 100, 101, 115, 107, 116, 111, 112, 46, 65, 118, 97, 104, 105, 46, 99, 111, 111, 107, 105, 101]]
        key = "org.freedesktop.Avahi.cookie"
        expected_value = True
        objid = _next_objid()
        service = Service(self._bus_name, objid, self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN, self._DEF_ADDRESS,
                self._DEF_PORT, props)
        value = service.get_one_property(key)
        assert value is not None and value == expected_value, "service properties weren't correct after init."

    def testActivityService(self):
        # Valid group service type, non-multicast address
        actid = "4569a71b80805aa96a847f7ac1c407327b3ec2b4"
        name = compose_service_name("Tommy", actid)

        # Valid activity service name, None address
        objid = _next_objid()
        service = Service(self._bus_name, objid, name, self._DEF_STYPE, self._DEF_DOMAIN, None,
                self._DEF_PORT, self._DEF_PROPS)
        assert service.get_address() == None, "address was not None as expected!"
        assert service.get_activity_id() == actid, "activity id was different than expected!"

        # Valid activity service name and multicast address, ensure it works
        mc_addr = u"224.0.0.34"
        objid = _next_objid()
        service = Service(self._bus_name, objid, name, self._DEF_STYPE, self._DEF_DOMAIN, mc_addr,
                self._DEF_PORT, self._DEF_PROPS)
        assert service.get_address() == mc_addr, "address was not expected address!"

    def addToSuite(suite):
        suite.addTest(ServiceTestCase("testName"))
        suite.addTest(ServiceTestCase("testType"))
        suite.addTest(ServiceTestCase("testDomain"))
        suite.addTest(ServiceTestCase("testAddress"))
        suite.addTest(ServiceTestCase("testPort"))
        suite.addTest(ServiceTestCase("testGoodInit"))
        suite.addTest(ServiceTestCase("testAvahiProperties"))
        suite.addTest(ServiceTestCase("testBoolProperty"))
        suite.addTest(ServiceTestCase("testActivityService"))
    addToSuite = staticmethod(addToSuite)


def main():
    suite = unittest.TestSuite()
    ServiceTestCase.addToSuite(suite)
    runner = unittest.TextTestRunner()
    runner.run(suite)

if __name__ == "__main__":
    main()