def __init__(self, app, on_exit): super(UIService, self).__init__() self.MENU_ENTRY_STATS = QtCore.QCoreApplication.translate("contextual_menu", "Statistics") self.MENU_ENTRY_FW_ENABLE = QtCore.QCoreApplication.translate("contextual_menu", "Enable") self.MENU_ENTRY_FW_DISABLE = QtCore.QCoreApplication.translate("contextual_menu", "Disable") self.MENU_ENTRY_HELP = QtCore.QCoreApplication.translate("contextual_menu", "Help") self.MENU_ENTRY_CLOSE = QtCore.QCoreApplication.translate("contextual_menu", "Close") self._cfg = Config.init() self._db = Database.instance() db_file=self._cfg.getSettings(self._cfg.DEFAULT_DB_FILE_KEY) db_status, db_error = self._db.initialize( dbtype=self._cfg.getInt(self._cfg.DEFAULT_DB_TYPE_KEY), dbfile=db_file ) if db_status is False: Message.ok( QtCore.QCoreApplication.translate("preferences", "Warning"), QtCore.QCoreApplication.translate("preferences", "The DB is corrupted and it's not safe to continue.<br>\ Remove, backup or recover the file before continuing.<br><br>\ Corrupted database file: {0}".format(db_file)), QtWidgets.QMessageBox.Warning) sys.exit(-1) self._db_sqlite = self._db.get_db() self._last_ping = None self._version_warning_shown = False self._asking = False self._connected = False self._fw_enabled = False self._path = os.path.abspath(os.path.dirname(__file__)) self._app = app self._on_exit = on_exit self._exit = False self._msg = QtWidgets.QMessageBox() self._prompt_dialog = PromptDialog() self._remote_lock = Lock() self._remote_stats = {} self._setup_interfaces() self._setup_icons() self._stats_dialog = StatsDialog(dbname="general", db=self._db) self._setup_tray() self._setup_slots() self._nodes = Nodes.instance() self._last_stats = {} self._last_items = { 'hosts':{}, 'procs':{}, 'addrs':{}, 'ports':{}, 'users':{} }
def __init__(self, app, on_exit): super(UIService, self).__init__() self.MENU_ENTRY_STATS = QtCore.QCoreApplication.translate( "contextual_menu", "Statistics") self.MENU_ENTRY_FW_ENABLE = QtCore.QCoreApplication.translate( "contextual_menu", "Enable") self.MENU_ENTRY_FW_DISABLE = QtCore.QCoreApplication.translate( "contextual_menu", "Disable") self.MENU_ENTRY_HELP = QtCore.QCoreApplication.translate( "contextual_menu", "Help") self.MENU_ENTRY_CLOSE = QtCore.QCoreApplication.translate( "contextual_menu", "Close") self._cfg = Config.init() self._db = Database.instance() self._db.initialize( dbtype=self._cfg.getInt(self._cfg.DEFAULT_DB_TYPE_KEY), dbfile=self._cfg.getSettings(self._cfg.DEFAULT_DB_FILE_KEY)) self._db_sqlite = self._db.get_db() self._last_ping = None self._version_warning_shown = False self._asking = False self._connected = False self._fw_enabled = False self._path = os.path.abspath(os.path.dirname(__file__)) self._app = app self._on_exit = on_exit self._exit = False self._msg = QtWidgets.QMessageBox() self._prompt_dialog = PromptDialog() self._remote_lock = Lock() self._remote_stats = {} self._setup_interfaces() self._setup_icons() self._stats_dialog = StatsDialog(dbname="general", db=self._db) self._setup_tray() self._setup_slots() self._nodes = Nodes.instance() self._last_stats = {} self._last_items = { 'hosts': {}, 'procs': {}, 'addrs': {}, 'ports': {}, 'users': {} }
def _on_new_remote(self, addr, request): self._remote_stats[addr] = { 'last_ping': datetime.now(), 'dialog': StatsDialog(address=addr, dbname=addr, db=self._db) } self._remote_stats[addr]['dialog'].daemon_connected = True self._remote_stats[addr]['dialog'].update(addr, request.stats) self._remote_stats[addr]['dialog'].show()
class UIService(ui_pb2_grpc.UIServicer, QtWidgets.QGraphicsObject): _new_remote_trigger = QtCore.pyqtSignal(str, ui_pb2.PingRequest) _update_stats_trigger = QtCore.pyqtSignal(str, str, ui_pb2.PingRequest) _version_warning_trigger = QtCore.pyqtSignal(str, str) _status_change_trigger = QtCore.pyqtSignal(bool) _notification_callback = QtCore.pyqtSignal(ui_pb2.NotificationReply) _show_message_trigger = QtCore.pyqtSignal(str, str, int, int) _delete_temp_rule_trigger = QtCore.pyqtSignal(str, str) def __init__(self, app, on_exit): super(UIService, self).__init__() self.MENU_ENTRY_STATS = QtCore.QCoreApplication.translate("contextual_menu", "Statistics") self.MENU_ENTRY_FW_ENABLE = QtCore.QCoreApplication.translate("contextual_menu", "Enable") self.MENU_ENTRY_FW_DISABLE = QtCore.QCoreApplication.translate("contextual_menu", "Disable") self.MENU_ENTRY_HELP = QtCore.QCoreApplication.translate("contextual_menu", "Help") self.MENU_ENTRY_CLOSE = QtCore.QCoreApplication.translate("contextual_menu", "Close") self._cfg = Config.init() self._db = Database.instance() db_file=self._cfg.getSettings(self._cfg.DEFAULT_DB_FILE_KEY) db_status, db_error = self._db.initialize( dbtype=self._cfg.getInt(self._cfg.DEFAULT_DB_TYPE_KEY), dbfile=db_file ) if db_status is False: Message.ok( QtCore.QCoreApplication.translate("preferences", "Warning"), QtCore.QCoreApplication.translate("preferences", "The DB is corrupted and it's not safe to continue.<br>\ Remove, backup or recover the file before continuing.<br><br>\ Corrupted database file: {0}".format(db_file)), QtWidgets.QMessageBox.Warning) sys.exit(-1) self._db_sqlite = self._db.get_db() self._last_ping = None self._version_warning_shown = False self._asking = False self._connected = False self._fw_enabled = False self._path = os.path.abspath(os.path.dirname(__file__)) self._app = app self._on_exit = on_exit self._exit = False self._msg = QtWidgets.QMessageBox() self._prompt_dialog = PromptDialog() self._remote_lock = Lock() self._remote_stats = {} self._setup_interfaces() self._setup_icons() self._stats_dialog = StatsDialog(dbname="general", db=self._db) self._setup_tray() self._setup_slots() self._nodes = Nodes.instance() self._last_stats = {} self._last_items = { 'hosts':{}, 'procs':{}, 'addrs':{}, 'ports':{}, 'users':{} } # https://gist.github.com/pklaus/289646 def _setup_interfaces(self): namestr, outbytes = Utils.get_interfaces() self._interfaces = {} for i in range(0, outbytes, 40): name = namestr[i:i+16].split(b'\0', 1)[0] addr = namestr[i+20:i+24] self._interfaces[name] = "%d.%d.%d.%d" % (int(addr[0]), int(addr[1]), int(addr[2]), int(addr[3])) def _setup_slots(self): # https://stackoverflow.com/questions/40288921/pyqt-after-messagebox-application-quits-why self._app.setQuitOnLastWindowClosed(False) self._version_warning_trigger.connect(self._on_diff_versions) self._new_remote_trigger.connect(self._on_new_remote) self._update_stats_trigger.connect(self._on_update_stats) self._status_change_trigger.connect(self._on_status_changed) self._stats_dialog._shown_trigger.connect(self._on_stats_dialog_shown) self._stats_dialog._status_changed_trigger.connect(self._on_stats_status_changed) self._show_message_trigger.connect(self._show_systray_message) self._delete_temp_rule_trigger.connect(self._delete_temporary_rule) def _setup_icons(self): self.off_image = QtGui.QPixmap(os.path.join(self._path, "res/icon-off.png")) self.off_icon = QtGui.QIcon() self.off_icon.addPixmap(self.off_image, QtGui.QIcon.Normal, QtGui.QIcon.Off) self.white_image = QtGui.QPixmap(os.path.join(self._path, "res/icon-white.svg")) self.white_icon = QtGui.QIcon() self.white_icon.addPixmap(self.white_image, QtGui.QIcon.Normal, QtGui.QIcon.Off) self.red_image = QtGui.QPixmap(os.path.join(self._path, "res/icon-red.png")) self.red_icon = QtGui.QIcon() self.red_icon.addPixmap(self.red_image, QtGui.QIcon.Normal, QtGui.QIcon.Off) self.pause_image = QtGui.QPixmap(os.path.join(self._path, "res/icon-pause.png")) self.pause_icon = QtGui.QIcon() self.pause_icon.addPixmap(self.pause_image, QtGui.QIcon.Normal, QtGui.QIcon.Off) self.alert_image = QtGui.QPixmap(os.path.join(self._path, "res/icon-alert.png")) self.alert_icon = QtGui.QIcon() self.alert_icon.addPixmap(self.alert_image, QtGui.QIcon.Normal, QtGui.QIcon.Off) self._app.setWindowIcon(self.white_icon) self._prompt_dialog.setWindowIcon(self.white_icon) def _setup_tray(self): self._menu = QtWidgets.QMenu() self._tray = QtWidgets.QSystemTrayIcon(self.off_icon) self._tray.setContextMenu(self._menu) self._tray.activated.connect(self._on_tray_icon_activated) self._menu.addAction(self.MENU_ENTRY_STATS).triggered.connect(self._show_stats_dialog) self._menu_enable_fw = self._menu.addAction(self.MENU_ENTRY_FW_DISABLE) self._menu_enable_fw.setEnabled(False) self._menu_enable_fw.triggered.connect(self._on_enable_interception_clicked) self._menu.addAction(self.MENU_ENTRY_HELP).triggered.connect( lambda: QtGui.QDesktopServices.openUrl(QtCore.QUrl(Config.HELP_CONFIG_URL)) ) self._menu.addAction(self.MENU_ENTRY_CLOSE).triggered.connect(self._on_close) self._tray.show() self._show_gui_if_tray_not_available() def _show_gui_if_tray_not_available(self): """If the system tray is not available or ready, show the GUI after 10s. This delay helps to skip showing up the GUI when DEs' autologin is on. """ tray = self._tray gui = self._stats_dialog def __show_gui(): if not tray.isSystemTrayAvailable(): gui.show() QtCore.QTimer.singleShot(10000, __show_gui) def _on_tray_icon_activated(self, reason): if reason == QtWidgets.QSystemTrayIcon.Trigger or reason == QtWidgets.QSystemTrayIcon.MiddleClick: if self._stats_dialog.isVisible() and not self._stats_dialog.isMinimized(): self._stats_dialog.hide() elif self._stats_dialog.isVisible() and self._stats_dialog.isMinimized() and not self._stats_dialog.isMaximized(): self._stats_dialog.hide() self._stats_dialog.showNormal() elif self._stats_dialog.isVisible() and self._stats_dialog.isMinimized() and self._stats_dialog.isMaximized(): self._stats_dialog.hide() self._stats_dialog.showMaximized() else: self._stats_dialog.show() def _on_close(self): self._exit = True self._on_exit() def _show_stats_dialog(self): if self._connected and self._fw_enabled: self._tray.setIcon(self.white_icon) self._stats_dialog.show() @QtCore.pyqtSlot(bool) def _on_stats_status_changed(self, enabled): self._update_fw_status(enabled) @QtCore.pyqtSlot(bool) def _on_status_changed(self, enabled): self._set_daemon_connected(enabled) @QtCore.pyqtSlot(str, str) def _on_diff_versions(self, daemon_ver, ui_ver): if self._version_warning_shown == False: self._msg.setIcon(QtWidgets.QMessageBox.Warning) self._msg.setWindowTitle("OpenSnitch version mismatch!") self._msg.setText(("You are running version <b>%s</b> of the daemon, while the UI is at version " + \ "<b>%s</b>, they might not be fully compatible.") % (daemon_ver, ui_ver)) self._msg.setStandardButtons(QtWidgets.QMessageBox.Ok) self._msg.show() self._version_warning_shown = True @QtCore.pyqtSlot(str, str, ui_pb2.PingRequest) def _on_update_stats(self, proto, addr, request): main_need_refresh, details_need_refresh = self._populate_stats(self._db, proto, addr, request.stats) is_local_request = self._is_local_request(proto, addr) self._stats_dialog.update(is_local_request, request.stats, main_need_refresh or details_need_refresh) @QtCore.pyqtSlot(str, ui_pb2.PingRequest) def _on_new_remote(self, addr, request): self._remote_stats[addr] = { 'last_ping': datetime.now(), 'dialog': StatsDialog(address=addr, dbname=addr, db=self._db) } self._remote_stats[addr]['dialog'].daemon_connected = True self._remote_stats[addr]['dialog'].update(addr, request.stats) self._remote_stats[addr]['dialog'].show() @QtCore.pyqtSlot() def _on_stats_dialog_shown(self): if self._connected: if self._fw_enabled: self._tray.setIcon(self.white_icon) else: self._tray.setIcon(self.pause_icon) else: self._tray.setIcon(self.off_icon) @QtCore.pyqtSlot(ui_pb2.NotificationReply) def _on_notification_reply(self, reply): if reply.code == ui_pb2.ERROR: self._tray.showMessage("Error", reply.data, QtWidgets.QSystemTrayIcon.Information, 5000) def _on_remote_stats_menu(self, address): self._remote_stats[address]['dialog'].show() @QtCore.pyqtSlot(str, str, int, int) def _show_systray_message(self, title, body, icon, timeout): if icon == QtWidgets.QSystemTrayIcon.NoIcon: self._tray.setIcon(self.alert_icon) self._tray.showMessage(title, body, icon, timeout) def _on_enable_interception_clicked(self): self._enable_interception(self._fw_enabled) def _update_fw_status(self, enabled): """_update_fw_status updates the status of the menu entry to disable or enable the firewall of the daemon. """ self._fw_enabled = enabled if self._connected == False: return self._stats_dialog.update_interception_status(enabled) if enabled: self._tray.setIcon(self.white_icon) self._menu_enable_fw.setText(self.MENU_ENTRY_FW_DISABLE) else: self._tray.setIcon(self.pause_icon) self._menu_enable_fw.setText(self.MENU_ENTRY_FW_ENABLE) def _set_daemon_connected(self, connected): """_set_daemon_connected only updates the connection status of the daemon(s), regardless if the fw is enabled or not. There're 3 states: - daemon connected - daemon not connected - daemon connected and firewall enabled/disabled """ self._stats_dialog.daemon_connected = connected self._connected = connected # if there're more than 1 node, override connection status if self._nodes.count() >= 1: self._connected = True self._stats_dialog.daemon_connected = True if self._nodes.count() == 1: self._menu_enable_fw.setEnabled(True) if self._nodes.count() == 0 or self._nodes.count() > 1: self._menu_enable_fw.setEnabled(False) self._stats_dialog.update_status() if self._connected: self._tray.setIcon(self.white_icon) else: self._fw_enabled = False self._tray.setIcon(self.off_icon) def _enable_interception(self, enable): if self._connected == False: return if self._nodes.count() == 0: self._tray.showMessage("No nodes connected", "", QtWidgets.QSystemTrayIcon.Information, 5000) return if self._nodes.count() > 1: print("enable interception for all nodes not supported yet") return if enable: nid, noti = self._nodes.stop_interception(_callback=self._notification_callback) else: nid, noti = self._nodes.start_interception(_callback=self._notification_callback) self._fw_enabled = not enable self._stats_dialog._status_changed_trigger.emit(not enable) def _is_local_request(self, proto, addr): if proto == "unix": return True elif proto == "ipv4" or proto == "ipv6": for name, ip in self._interfaces.items(): if addr == ip: return True return False def _get_peer(self, peer): """ server -> client 127.0.0.1:50051 -> ipv4:127.0.0.1:52032 [::]:50051 -> ipv6:[::1]:59680 0.0.0.0:50051 -> ipv6:[::1]:59654 """ return self._nodes.get_addr(peer) def _delete_node(self, peer): try: proto, addr = self._get_peer(peer) if addr in self._last_stats: del self._last_stats[addr] for table in self._last_items: if addr in self._last_items[table]: del self._last_items[table][addr] self._nodes.update(proto, addr, Nodes.OFFLINE) self._nodes.delete(peer) self._stats_dialog.update(True, None, True) except Exception as e: print("_delete_node() exception:", e) def _populate_stats(self, db, proto, addr, stats): main_need_refresh = False details_need_refresh = False try: if db == None: print("populate_stats() db None") return main_need_refresh, details_need_refresh _node = self._nodes.get_node(proto+":"+addr) if _node == None: return main_need_refresh, details_need_refresh # TODO: move to nodes.add_node() version = _node['data'].version if _node != None else "" hostname = _node['data'].name if _node != None else "" db.insert("nodes", "(addr, status, hostname, daemon_version, daemon_uptime, " \ "daemon_rules, cons, cons_dropped, version, last_connection)", (addr, Nodes.ONLINE, hostname, stats.daemon_version, str(timedelta(seconds=stats.uptime)), stats.rules, stats.connections, stats.dropped, version, datetime.now().strftime("%Y-%m-%d %H:%M:%S"))) if addr not in self._last_stats: self._last_stats[addr] = [] for event in stats.events: if event.unixnano in self._last_stats[addr]: continue main_need_refresh=True db.insert("connections", "(time, node, action, protocol, src_ip, src_port, dst_ip, dst_host, dst_port, uid, pid, process, process_args, process_cwd, rule)", (str(datetime.fromtimestamp(event.unixnano/1000000000)), "%s:%s" % (proto, addr), event.rule.action, event.connection.protocol, event.connection.src_ip, str(event.connection.src_port), event.connection.dst_ip, event.connection.dst_host, str(event.connection.dst_port), str(event.connection.user_id), str(event.connection.process_id), event.connection.process_path, " ".join(event.connection.process_args), event.connection.process_cwd, event.rule.name), action_on_conflict="IGNORE" ) self._nodes.update_rule_time( str(datetime.fromtimestamp(event.unixnano/1000000000)), event.rule.name, "%s:%s" % (proto, addr) ) details_need_refresh = self._populate_stats_details(db, addr, stats) self._last_stats[addr] = [] for event in stats.events: self._last_stats[addr].append(event.unixnano) except Exception as e: print("_populate_stats() exception: ", e) return main_need_refresh, details_need_refresh def _populate_stats_details(self, db, addr, stats): need_refresh = False changed = self._populate_stats_events(db, addr, stats, "hosts", ("what", "hits"), (1,2), stats.by_host.items()) if changed: need_refresh = True changed = self._populate_stats_events(db, addr, stats, "procs", ("what", "hits"), (1,2), stats.by_executable.items()) if changed: need_refresh = True changed = self._populate_stats_events(db, addr, stats, "addrs", ("what", "hits"), (1,2), stats.by_address.items()) if changed: need_refresh = True changed = self._populate_stats_events(db, addr, stats, "ports", ("what", "hits"), (1,2), stats.by_port.items()) if changed: need_refresh = True changed = self._populate_stats_events(db, addr, stats, "users", ("what", "hits"), (1,2), stats.by_uid.items()) if changed: need_refresh = True return need_refresh def _populate_stats_events(self, db, addr, stats, table, colnames, cols, items): fields = [] values = [] need_refresh = False try: if addr not in self._last_items[table].keys(): self._last_items[table][addr] = {} if items == self._last_items[table][addr]: return need_refresh for row, event in enumerate(items): if event in self._last_items[table][addr]: continue need_refresh = True what, hits = event # FIXME: this is suboptimal # BUG: there can be users with same id on different machines but with different names if table == "users": what = Utils.get_user_id(what) fields.append(what) values.append(int(hits)) # FIXME: default action on conflict is to replace. If there're multiple nodes connected, # stats are painted once per node on each update. if need_refresh: db.insert_batch(table, colnames, cols, fields, values) self._last_items[table][addr] = items except Exception as e: print("details exception: ", e) return need_refresh def _delete_temporary_rule(self, name, addr): self._db.delete_rule(name, addr) def _overwrite_nodes_config(self, node_config): _default_action = self._cfg.getInt(self._cfg.DEFAULT_ACTION_KEY) temp_cfg = json.loads(node_config) try: if _default_action == Config.ACTION_DENY_IDX: temp_cfg['DefaultAction'] = Config.ACTION_DENY else: temp_cfg['DefaultAction'] = Config.ACTION_ALLOW node_config = json.dumps(temp_cfg) except Exception as e: print("error parsing node's configuration:", e) return node_config def Ping(self, request, context): try: self._last_ping = datetime.now() if Utils.check_versions(request.stats.daemon_version): self._version_warning_trigger.emit(request.stats.daemon_version, version) proto, addr = self._get_peer(context.peer()) # do not update db here, do it on the main thread self._update_stats_trigger.emit(proto, addr, request) #else: # with self._remote_lock: # # XXX: disable this option for now # # opening several dialogs only updates one of them. # if addr not in self._remote_stats: # self._new_remote_trigger.emit(addr, request) # else: # self._populate_stats(self._remote_stats[addr]['dialog'].get_db(), proto, addr, request.stats) # self._remote_stats[addr]['dialog'].update(addr, request.stats) except Exception as e: print("Ping exception: ", e) return ui_pb2.PingReply(id=request.id) def AskRule(self, request, context): # TODO: allow connections originated from ourselves: os.getpid() == request.pid) self._asking = True proto, addr = self._get_peer(context.peer()) rule, timeout_triggered = self._prompt_dialog.promptUser(request, self._is_local_request(proto, addr), context.peer()) if timeout_triggered: _title = request.process_path if _title == "": _title = "%s:%d (%s)" % (request.dst_host if request.dst_host != "" else request.dst_ip, request.dst_port, request.protocol) node_text = "" if self._is_local_request(proto, addr) else "on node {0}:{1}".format(proto, addr) self._show_message_trigger.emit(_title, "{0} action applied {1}\nArguments: {2}" .format(rule.action, node_text, request.process_args), QtWidgets.QSystemTrayIcon.NoIcon, 0) self._last_ping = datetime.now() self._asking = False if rule.duration in Config.RULES_DURATION_FILTER: self._delete_temporary_rule(rule.name, context.peer()) else: self._nodes.add_rule((datetime.now().strftime("%Y-%m-%d %H:%M:%S")), "{0}:{1}".format(proto, addr), rule.name, str(rule.enabled), str(rule.precedence), rule.action, rule.duration, rule.operator.type, str(rule.operator.sensitive), rule.operator.operand, rule.operator.data) return rule def Subscribe(self, node_config, context): """ Accept and collect nodes. It keeps a connection open with each client, in order to send them notifications. @doc: https://grpc.github.io/grpc/python/grpc.html#service-side-context """ try: proto, addr = self._get_peer(context.peer()) if self._is_local_request(proto, addr) == False: self._show_message_trigger.emit("New node connected", "({0})".format(context.peer()), QtWidgets.QSystemTrayIcon.Information, 5000) n = self._nodes.add(context, node_config) if n != None: self._status_change_trigger.emit(True) # if there're more than one node, we can't update the status # based on the fw status, only if the daemon is running or not if self._nodes.count() <= 1: self._update_fw_status(node_config.isFirewallRunning) else: self._update_fw_status(True) except Exception as e: print("[Notifications] exception adding new node:", e) context.cancel() node_config.config = self._overwrite_nodes_config(node_config.config) return node_config def Notifications(self, node_iter, context): """ Accept and collect nodes. It keeps a connection open with each client, in order to send them notifications. @doc: https://grpc.github.io/grpc/python/grpc.html#service-side-context @doc: https://grpc.io/docs/what-is-grpc/core-concepts/ """ proto, addr = self._get_peer(context.peer()) _node = self._nodes.get_node("%s:%s" % (proto, addr)) stop_event = Event() def _on_client_closed(): stop_event.set() self._delete_node(context.peer()) self._status_change_trigger.emit(False) # TODO: handle the situation when a node disconnects, and the # remaining node has the fw disabled. #if self._nodes.count() == 1: # nd = self._nodes.get_nodes() # if nd[0].get_config().isFirewallRunning: if self._is_local_request(proto, addr) == False: self._show_message_trigger.emit("node exited", "({0})".format(context.peer()), QtWidgets.QSystemTrayIcon.Information, 5000) context.add_callback(_on_client_closed) # TODO: move to notifications.py def new_node_message(): print("new node connected, listening for client responses...", addr) while self._exit == False: try: if stop_event.is_set(): break in_message = next(node_iter) if in_message == None: continue self._nodes.reply_notification(addr, in_message) except StopIteration: print("[Notifications] Node {0} exited".format(addr)) break except grpc.RpcError as e: print("[Notifications] grpc exception new_node_message(): ", addr, in_message) except Exception as e: print("[Notifications] unexpected exception new_node_message(): ", addr, e, in_message) read_thread = Thread(target=new_node_message) read_thread.daemon = True read_thread.start() while self._exit == False: if stop_event.is_set(): break try: noti = _node['notifications'].get() if noti != None: _node['notifications'].task_done() yield noti except Exception as e: print("[Notifications] exception getting notification from queue:", addr, e) context.cancel() return node_iter