# -*- coding: utf-8 -*- # # Copyright (C) 2013 GNS3 Technologies 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 3 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, see . """ Base class (interface) for modules """ import sys import gns3server.jsonrpc as jsonrpc import multiprocessing import zmq import signal import logging log = logging.getLogger(__name__) class IModule(multiprocessing.Process): """ Module interface. :param name: module name :param args: arguments for the module :param kwargs: named arguments for the module """ modules = {} def __init__(self, name, *args, **kwargs): multiprocessing.Process.__init__(self, name=name) self._context = None self._ioloop = None self._stream = None self._host = args[0] self._port = args[1] self._current_session = None self._current_destination = None self._current_call_id = None def _setup(self): """ Sets up PyZMQ and creates the stream to handle requests """ self._context = zmq.Context() self._ioloop = zmq.eventloop.ioloop.IOLoop.instance() self._stream = self._create_stream(self._host, self._port, self._decode_request) def _create_stream(self, host=None, port=0, callback=None): """ Creates a new ZMQ stream. :returns: ZMQ stream instance """ socket = self._context.socket(zmq.DEALER) socket.setsockopt(zmq.IDENTITY, self.name.encode("utf-8")) if host and port: log.info("ZeroMQ client ({}) connecting to {}:{}".format(self.name, host, port)) try: socket.connect("tcp://{}:{}".format(host, port)) except zmq.error.ZMQError as e: log.critical("Could not connect to ZeroMQ server on {}:{}, reason: {}".format(host, port, e)) raise SystemExit else: log.info("ZeroMQ client ({}) connecting to ipc:///tmp/gns3.ipc".format(self.name)) try: socket.connect("ipc:///tmp/gns3.ipc") except zmq.error.ZMQError as e: log.critical("Could not connect to ZeroMQ server on ipc:///tmp/gns3.ipc, reason: {}".format(e)) raise SystemExit stream = zmq.eventloop.zmqstream.ZMQStream(socket, self._ioloop) if callback: stream.on_recv(callback) return stream def add_periodic_callback(self, callback, time): """ Adds a periodic callback to the ioloop. :param callback: callback to be called :param time: frequency when the callback is executed """ periodic_callback = zmq.eventloop.ioloop.PeriodicCallback(callback, time, self._ioloop) return periodic_callback def run(self): """ Starts the event loop """ def signal_handler(signum=None, frame=None): log.warning("Module {} got signal {}, exiting...".format(self.name, signum)) self.stop() signals = [signal.SIGTERM, signal.SIGINT] if not sys.platform.startswith("win"): signals.extend([signal.SIGHUP, signal.SIGQUIT]) else: signals.extend([signal.SIGBREAK]) for sig in signals: signal.signal(sig, signal_handler) log.info("{} module running with PID {}".format(self.name, self.pid)) self._setup() try: self._ioloop.start() except KeyboardInterrupt: return def stop(self): """ Stops the event loop. """ if self._ioloop: self._ioloop.stop() def send_response(self, results): """ Sends a response back to the requester. :param results: JSON results to the ZeroMQ server """ jsonrpc_response = jsonrpc.JSONRPCResponse(results, self._current_call_id)() # add session to the response response = [self._current_session, jsonrpc_response] log.debug("ZeroMQ client ({}) sending: {}".format(self.name, response)) self._stream.send_json(response) def send_param_error(self): """ Sends a param error back to the requester. """ jsonrpc_response = jsonrpc.JSONRPCInvalidParams(self._current_call_id)() # add session to the response response = [self._current_session, jsonrpc_response] log.info("ZeroMQ client ({}) sending JSON-RPC param error for call id {}".format(self.name, self._current_call_id)) self._stream.send_json(response) def send_internal_error(self): """ Sends a param error back to the requester. """ jsonrpc_response = jsonrpc.JSONRPCInternalError()() # add session to the response response = [self._current_session, jsonrpc_response] log.critical("ZeroMQ client ({}) sending JSON-RPC internal error".format(self.name)) self._stream.send_json(response) def send_custom_error(self, message, code=-3200): """ Sends a custom error back to the requester. """ jsonrpc_response = jsonrpc.JSONRPCCustomError(code, message, self._current_call_id)() # add session to the response response = [self._current_session, jsonrpc_response] log.info("ZeroMQ client ({}) sending JSON-RPC custom error: {} for call id {}".format(self.name, message, self._current_call_id)) self._stream.send_json(response) def send_notification(self, destination, results): """ Sends a notification :param destination: destination (or method) :param results: JSON results to the ZeroMQ router """ jsonrpc_response = jsonrpc.JSONRPCNotification(destination, results)() # add session to the response response = [self._current_session, jsonrpc_response] log.debug("ZeroMQ client ({}) sending: {}".format(self.name, response)) self._stream.send_json(response) def _decode_request(self, request): """ Decodes the request to JSON. :param request: request from ZeroMQ server """ try: request = zmq.utils.jsonapi.loads(request[0]) except ValueError: self._current_session = None self.send_internal_error() return log.debug("ZeroMQ client ({}) received: {}".format(self.name, request)) self._current_session = request[0] self._current_call_id = request[1].get("id") destination = request[1].get("method") params = request[1].get("params") if destination not in self.modules[self.name]: self.send_internal_error() return log.debug("Routing request to {}: {}".format(destination, request[1])) try: self.modules[self.name][destination](self, params) except Exception as e: log.error("uncaught exception {type}".format(type=type(e)), exc_info=1) self.send_custom_error("uncaught exception {type}: {string}".format(type=type(e), string=str(e))) def destinations(self): """ Destinations handled by this module. :returns: list of destinations """ if not self.name in self.modules: log.warn("no destinations found for module {}".format(self.name)) return [] return self.modules[self.name].keys() @classmethod def route(cls, destination): """ Decorator to register a destination routed to a method :param destination: destination to be routed """ def wrapper(method): module = destination.split(".")[0] if not module in cls.modules: cls.modules[module] = {} cls.modules[module][destination] = method return method return wrapper