import threading import avahi, dbus, dbus.glib, dbus.dbus_bindings, gobject import Buddy import Service import os import string from sugar import util def _get_local_ip_address(ifname): """Call Linux specific bits to retrieve our own IP address.""" import socket import sys import fcntl addr = None SIOCGIFADDR = 0x8915 sockfd = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) try: ifreq = (ifname + '\0'*32)[:32] result = fcntl.ioctl(sockfd.fileno(), SIOCGIFADDR, ifreq) addr = socket.inet_ntoa(result[20:24]) except IOError, exc: print "Error getting IP address: %s" % exc sockfd.close() return addr class ServiceAdv(object): """Wrapper class for service attributes that Avahi passes back.""" def __init__(self, interface, protocol, name, stype, domain): self._interface = interface self._protocol = protocol self._name = name self._stype = stype self._domain = domain self._service = None self._resolved = False def interface(self): return self._interface def protocol(self): return self._protocol def name(self): return self._name def stype(self): return self._stype def domain(self): return self._domain def service(self): return self._service def set_service(self, service): if not isinstance(service, Service.Service): raise ValueError("must be a valid service.") self._service = service def resolved(self): return self._resolved def set_resolved(self, resolved): self._resolved = resolved class PresenceService(gobject.GObject): """Object providing information about the presence of Buddies and what activities they make available to others.""" __gsignals__ = { 'buddy-appeared': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE, ([gobject.TYPE_PYOBJECT])), 'buddy-disappeared': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE, ([gobject.TYPE_PYOBJECT])) } __lock = threading.Lock() __instance = None def get_instance(): """Return, creating if needed, the singleton PresenceService object.""" PresenceService.__lock.acquire() if not PresenceService.__instance: PresenceService.__instance = PresenceService() PresenceService.__lock.release() return PresenceService.__instance get_instance = staticmethod(get_instance) def __init__(self, debug=False): gobject.GObject.__init__(self) self._debug = debug self._lock = threading.Lock() self._started = False # interface -> IP address: interfaces we've gotten events on so far self._local_addrs = {} # nick -> Buddy: buddies we've found self._buddies = {} # Our owner object self._owner = None # activity UID -> Service: services grouped by activity UID self._activity_services = {} # All the mdns service types we care about self._allowed_service_types = [] # Keep track of stuff we're already browsing with ZC self._service_type_browsers = {} self._service_browsers = {} # Resolved service list self._service_advs = [] # Main activity UID to filter services on self._activity_uid = None self._bus = dbus.SystemBus() self._server = dbus.Interface(self._bus.get_object(avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER), avahi.DBUS_INTERFACE_SERVER) def start(self, activity_uid=None): """Start the presence service by kicking off service discovery.""" self._lock.acquire() if self._started: self._lock.release() return self._started = True self._lock.release() if activity_uid and not util.validate_activity_uid(activity_uid): raise ValueError("activity uid must be a valid UID string.") self._activity_uid = activity_uid # Always browse .local self._new_domain_cb(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, "local") # Connect to Avahi and start looking for stuff domain_browser = self._server.DomainBrowserNew(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, "", avahi.DOMAIN_BROWSER_BROWSE, dbus.UInt32(0)) db = dbus.Interface(self._bus.get_object(avahi.DBUS_NAME, domain_browser), avahi.DBUS_INTERFACE_DOMAIN_BROWSER) db.connect_to_signal('ItemNew', self._new_domain_cb_glue) def set_debug(self, debug): self._debug = debug def _log(self, msg): """Simple logger.""" if self._debug: print "PresenceService(%d): %s" % (os.getpid(), msg) def get_owner(self): """Return the owner of this machine/instance, if we've recognized them yet.""" return self._owner def _resolve_service_error_handler(self, err): self._log("error resolving service: %s" % err) def _find_service_adv(self, interface=None, protocol=None, name=None, stype=None, domain=None): """Search a list of service advertisements for ones matching certain criteria.""" adv_list = [] for adv in self._service_advs: if interface and adv.interface() != interface: continue if protocol and adv.protocol() != protocol: continue if name and adv.name() != name: continue if stype and adv.stype() != stype: continue if domain and adv.domain() != domain: continue adv_list.append(adv) if not len(adv_list): return None return adv_list def _is_special_service_type(self, stype): """Return True if the service type is a special, internal service type, and False if it's not.""" if stype == Buddy.PRESENCE_SERVICE_TYPE: return True return False def _handle_new_service_for_buddy(self, service): """Deal with a new discovered service object.""" # Once a service is resolved, we match it up to an existing buddy, # or create a new Buddy if this is the first service known about the buddy buddy_was_valid = False name = service.get_name() buddy = None try: buddy = self._buddies[name] buddy_was_valid = buddy.is_valid() buddy.add_service(service) except KeyError: # Should this service mark the owner? if service.get_address() in self._local_addrs.values(): buddy = Buddy.Owner(service) self._owner = buddy else: buddy = Buddy.Buddy(service) self._buddies[name] = buddy if not buddy_was_valid and buddy.is_valid(): self.emit("buddy-appeared", buddy) return buddy def _handle_new_service_for_activity(self, service, buddy): # If the serivce is a group service, merge it into our groups list uid = service.get_activity_uid() if not uid: uid = "*" if not self._activity_services.has_key(uid): self._activity_services[uid] = [] self._activity_services[uid].append((buddy, service)) def _handle_remove_service_for_activity(self, service, buddy): uid = service.get_activity_uid() if not uid: uid = "*" if self._activity_services.has_key(uid): try: self._activity_services.remove((buddy, service)) except: pass def _resolve_service_reply_cb(self, interface, protocol, name, stype, domain, host, aprotocol, address, port, txt, flags): """When the service discovery finally gets here, we've got enough information about the service to assign it to a buddy.""" self._log("resolved service '%s' type '%s' domain '%s' to %s:%s" % (name, stype, domain, address, port)) # If this service was previously unresolved, remove it from the # unresolved list adv_list = self._find_service_adv(interface=interface, protocol=protocol, name=name, stype=stype, domain=domain) if not adv_list: return False adv = adv_list[0] adv.set_resolved(True) # Update the service now that it's been resolved service = Service.Service(name=name, stype=stype, domain=domain, address=address, port=port, properties=txt) adv.set_service(service) # Merge the service into our buddy and group lists, if needed buddy = self._handle_new_service_for_buddy(service) if buddy and service.get_activity_uid(): self._handle_new_service_for_activity(service, buddy) return False def _resolve_service_reply_cb_glue(self, interface, protocol, name, stype, domain, host, aprotocol, address, port, txt, flags): gobject.idle_add(self._resolve_service_reply_cb, interface, protocol, name, stype, domain, host, aprotocol, address, port, txt, flags) def _resolve_service(self, interface, protocol, name, stype, domain, flags): """Resolve and lookup a ZeroConf service to obtain its address and TXT records.""" # Ask avahi to resolve this particular service self._server.ResolveService(int(interface), int(protocol), name, stype, domain, avahi.PROTO_UNSPEC, dbus.UInt32(0), # use flags here maybe? reply_handler=self._resolve_service_reply_cb_glue, error_handler=self._resolve_service_error_handler) return False def _service_appeared_cb(self, interface, protocol, name, stype, domain, flags): self._log("found service '%s' (%d) of type '%s' in domain '%s' on %i.%i." % (name, flags, stype, domain, interface, protocol)) # Add the service to our unresolved services list adv_list = self._find_service_adv(interface=interface, protocol=protocol, name=name, stype=stype, domain=domain) if not adv_list: adv = ServiceAdv(interface=interface, protocol=protocol, name=name, stype=stype, domain=domain) self._service_advs.append(adv) # Find out the IP address of this interface, if we haven't already if interface not in self._local_addrs.keys(): ifname = self._server.GetNetworkInterfaceNameByIndex(interface) if ifname: addr = _get_local_ip_address(ifname) if addr: self._local_addrs[interface] = addr # Decompose service type if we can (uid, stype) = Service._decompose_service_type(stype) # If we care about the service right now, resolve it resolve = False if self._activity_uid and self._activity_uid == uid: if stype in self._allowed_service_types: resolve = True elif not self._activity_uid: resolve = True if self._is_special_service_type(stype): resolve = True if resolve: gobject.idle_add(self._resolve_service, interface, protocol, name, stype, domain, flags) return False def _service_appeared_cb_glue(self, interface, protocol, name, stype, domain, flags): gobject.idle_add(self._service_appeared_cb, interface, protocol, name, stype, domain, flags) def _service_disappeared_cb(self, interface, protocol, name, stype, domain, flags): self._log("service '%s' of type '%s' in domain '%s' on %i.%i disappeared." % (name, stype, domain, interface, protocol)) # If it's an unresolved service, remove it from our unresolved list adv_list = self._find_service_adv(interface=interface, protocol=protocol, name=name, stype=stype, domain=domain) if not adv_list: return False # Get the service object; if none, we have nothing left to do adv = adv_list[0] service = adv.service() if not service: return False # Remove the service from the buddy try: buddy = self._buddies[name] except KeyError: pass else: buddy.remove_service(service) if not buddy.is_valid(): self.emit("buddy-disappeared", buddy) del self._buddies[name] self._handle_remove_service_for_activity(service, buddy) return False def _service_disappeared_cb_glue(self, interface, protocol, name, stype, domain, flags): gobject.idle_add(self._service_disappeared_cb, interface, protocol, name, stype, domain, flags) def _new_service_type_cb(self, interface, protocol, stype, domain, flags): # Are we already browsing this domain for this type? if self._service_browsers.has_key((interface, protocol, stype, domain)): return # Start browsing for all services of this type in this domain s_browser = self._server.ServiceBrowserNew(interface, protocol, stype, domain, dbus.UInt32(0)) browser_obj = dbus.Interface(self._bus.get_object(avahi.DBUS_NAME, s_browser), avahi.DBUS_INTERFACE_SERVICE_BROWSER) self._log("now browsing for services of type '%s' in domain '%s' on %i.%i ..." % (stype, domain, interface, protocol)) browser_obj.connect_to_signal('ItemNew', self._service_appeared_cb_glue) browser_obj.connect_to_signal('ItemRemove', self._service_disappeared_cb_glue) self._service_browsers[(interface, protocol, stype, domain)] = browser_obj return False def _new_service_type_cb_glue(self, interface, protocol, stype, domain, flags): gobject.idle_add(self._new_service_type_cb, interface, protocol, stype, domain, flags) def _new_domain_cb(self, interface, protocol, domain, flags=0): """Callback from Avahi when a new domain has been found. Start browsing the new domain.""" # Only use .local for now... if domain != "local": return # Are we already browsing this domain? if self._service_type_browsers.has_key((interface, protocol, domain)): return # Start browsing this domain for the services its members offer try: st_browser = self._server.ServiceTypeBrowserNew(interface, protocol, domain, dbus.UInt32(0)) browser_obj = dbus.Interface(self._bus.get_object(avahi.DBUS_NAME, st_browser), avahi.DBUS_INTERFACE_SERVICE_TYPE_BROWSER) except dbus.DBusException, exc: self._log("got exception %s while attempting to browse domain %s on %i.%i" % (domain, interface, protocol)) str_exc = str(exc) if str_exc.find("The name org.freedesktop.Avahi was not provided by any .service files") >= 0: raise Exception("Avahi does not appear to be running. '%s'" % str_exc) else: raise exc self._log("now browsing domain '%s' on %i.%i ..." % (domain, interface, protocol)) browser_obj.connect_to_signal('ItemNew', self._new_service_type_cb_glue) self._service_type_browsers[(interface, protocol, domain)] = browser_obj return False def _new_domain_cb_glue(self, interface, protocol, domain, flags=0): gobject.idle_add(self._new_domain_cb, interface, protocol, domain, flags) def track_service_type(self, stype): """Requests that the Presence service look for and recognize a certain mDNS service types.""" if not self._started: raise RuntimeError("presence service must be started first.") if not type(stype) == type(""): raise ValueError("service type must be a string.") if self._is_special_service_type(stype): return if stype in self._allowed_service_types: return self._allowed_service_types.append(stype) # Find unresolved services that match the service type # we're now interested in, and resolve them adv_list = self._find_service_adv(stype=stype) for adv in adv_list: gobject.idle_add(self._resolve_service, adv.interface(), adv.protocol(), adv.name(), adv.stype(), adv.domain(), 0) def untrack_service_type(self, stype): """Stop tracking a certain mDNS service.""" if not self._started: raise RuntimeError("presence service must be started first.") if not type(stype) == type(""): raise ValueError("service type must be a string.") if name in self._allowed_service_types: self._allowed_service_types.remove(stype) def join_group(self, group): """Convenience function to join a group and notify other buddies that you are a member of it.""" if not isinstance(group, Group.Group): raise ValueError("group was not a valid group.") gservice = group.get_service() self.register_service(service) def register_service(self, service): """Register a new service, advertising it to other Buddies on the network.""" if not self._started: raise RuntimeError("presence service must be started first.") rs_name = service.get_name() rs_stype = service.get_type() rs_port = service.get_port() if type(rs_port) != type(1) and (rs_port <= 1024 or rs_port > 65536): raise ValueError("invalid service port.") rs_props = service.get_properties() rs_domain = service.get_domain() if not rs_domain or not len(rs_domain): rs_domain = "" self._log("registered service name '%s' type '%s' on port %d with args %s" % (rs_name, rs_stype, rs_port, rs_props)) try: group = dbus.Interface(self._bus.get_object(avahi.DBUS_NAME, self._server.EntryGroupNew()), avahi.DBUS_INTERFACE_ENTRY_GROUP) info = ["%s=%s" % (k, v) for k, v in rs_props.items()] group.AddService(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, 0, rs_name, rs_stype, rs_domain, "", # let Avahi figure the 'host' out dbus.UInt16(rs_port), info,) group.Commit() except dbus.dbus_bindings.DBusException, exc: # FIXME: ignore local name collisions, since that means # the zeroconf service is already registered. Ideally we # should un-register it an re-register with the correct info if str(exc) == "Local name collision": pass self.track_service_type(rs_stype) return group def get_buddy_by_nick_name(self, nick_name): """Look up and return a buddy by nickname.""" if self._buddies.has_key(nick_name): return self._buddies[nick_name] return None def get_buddy_by_address(self, address): for buddy in self._buddies.values(): if buddy.get_address == address: return buddy return None def get_buddies(self): """Return the entire buddy list.""" return self._buddies.values() ################################################################# # Tests ################################################################# import unittest ps = None class PresenceServiceTestCase(unittest.TestCase): _DEF_NAME = "Paul" _DEF_STYPE = Buddy.PRESENCE_SERVICE_TYPE _DEF_DOMAIN = "local" _DEF_PORT = 3333 _DEF_PROPERTIES = {"foo": "bar", "bork": "baz"} def testNoServices(self): """Ensure that no services are found initially.""" """This test may illegitimately fail if there's another person on the network running sugar... So its usefulness is somewhat dubious.""" import gtk global ps buddies = ps.get_buddies() assert len(buddies) == 0, "A buddy was found without setting tracked services!" gtk.main_quit() def testServiceRegistration(self): service = Service.Service(self._DEF_NAME, self._DEF_STYPE, self._DEF_DOMAIN, address=None, port=self._DEF_PORT, properties=self._DEF_PROPERTIES) global ps ps.register_service(service) # Give the Presence Service some time to find the new service gobject.timeout_add(2000, self.quitMain) import gtk gtk.main() def quitMain(self): import gtk gtk.main_quit() def testServiceDetection(self): global ps buddy = ps.get_buddy_by_nick_name("Paul") assert buddy, "The registered buddy was not found after 2 seconds!" assert buddy.is_valid(), "The buddy was invalid, since no presence was advertised." assert buddy.is_owner() == True, "The buddy was not the owner, but it should be!" def addToSuite(suite): suite.addTest(PresenceServiceTestCase("testNoServices")) suite.addTest(PresenceServiceTestCase("testServiceRegistration")) suite.addTest(PresenceServiceTestCase("testServiceDetection")) addToSuite = staticmethod(addToSuite) def runTests(): suite = unittest.TestSuite() PresenceServiceTestCase.addToSuite(suite) runner = unittest.TextTestRunner() runner.run(suite) def main(): import pygtk, gtk global ps ps = PresenceService.get_instance() ps.set_debug(True) ps.start() gobject.timeout_add(4000, runTests) gtk.main() if __name__ == "__main__": main()