diff options
Diffstat (limited to 'src/leap/bitmask/backend')
| -rw-r--r-- | src/leap/bitmask/backend/api.py | 2 | ||||
| -rw-r--r-- | src/leap/bitmask/backend/backend.py | 6 | ||||
| -rw-r--r-- | src/leap/bitmask/backend/backend_proxy.py | 64 |
3 files changed, 61 insertions, 11 deletions
diff --git a/src/leap/bitmask/backend/api.py b/src/leap/bitmask/backend/api.py index b8533f36..4f52e470 100644 --- a/src/leap/bitmask/backend/api.py +++ b/src/leap/bitmask/backend/api.py @@ -18,10 +18,12 @@ Backend available API and SIGNALS definition. """ STOP_REQUEST = "stop" +PING_REQUEST = "PING" API = ( STOP_REQUEST, # this method needs to be defined in order to support the # backend stop action + PING_REQUEST, "eip_can_start", "eip_cancel_setup", diff --git a/src/leap/bitmask/backend/backend.py b/src/leap/bitmask/backend/backend.py index 833f4368..c895f8f5 100644 --- a/src/leap/bitmask/backend/backend.py +++ b/src/leap/bitmask/backend/backend.py @@ -23,7 +23,7 @@ from twisted.internet import defer, reactor, threads import zmq from zmq.auth.thread import ThreadAuthenticator -from leap.bitmask.backend.api import API +from leap.bitmask.backend.api import API, PING_REQUEST from leap.bitmask.backend.utils import get_backend_certificates from leap.bitmask.backend.signaler import Signaler @@ -146,6 +146,10 @@ class Backend(object): :param request_json: a json specification of a request. :type request_json: str """ + if request_json == PING_REQUEST: + # do not process request if it's just a ping + return + try: # request = zmq.utils.jsonapi.loads(request_json) # We use stdlib's json to ensure that we get unicode strings diff --git a/src/leap/bitmask/backend/backend_proxy.py b/src/leap/bitmask/backend/backend_proxy.py index f683e465..dc30d2cb 100644 --- a/src/leap/bitmask/backend/backend_proxy.py +++ b/src/leap/bitmask/backend/backend_proxy.py @@ -25,7 +25,7 @@ import time import zmq -from leap.bitmask.backend.api import API, STOP_REQUEST +from leap.bitmask.backend.api import API, STOP_REQUEST, PING_REQUEST from leap.bitmask.backend.utils import get_backend_certificates import logging @@ -40,6 +40,11 @@ class BackendProxy(object): PORT = '5556' SERVER = "tcp://localhost:%s" % PORT + POLL_TIMEOUT = 4000 # ms + POLL_TRIES = 3 + + PING_INTERVAL = 2 # secs + def __init__(self): self._socket = None @@ -62,6 +67,9 @@ class BackendProxy(object): socket.connect(self.SERVER) self._socket = socket + self._ping_at = 0 + self.online = False + self._call_queue = Queue.Queue() self._worker_caller = threading.Thread(target=self._worker) self._worker_caller.start() @@ -82,9 +90,26 @@ class BackendProxy(object): except Queue.Empty: pass time.sleep(0.01) + self._ping() logger.debug("BackendProxy worker stopped.") + def _reset_ping(self): + """ + Reset the ping timeout counter. + This is called for every ping and request. + """ + self._ping_at = time.time() + self.PING_INTERVAL + + def _ping(self): + """ + Heartbeat helper. + Sends a PING request just to know that the server is alive. + """ + if time.time() > self._ping_at: + self._send_request(PING_REQUEST) + self._reset_ping() + def _api_call(self, *args, **kwargs): """ Call the `api_method` method in backend (through zmq). @@ -134,16 +159,35 @@ class BackendProxy(object): # logger.debug("Sending request to backend: {0}".format(request)) self._socket.send(request) - try: - # Get the reply. - self._socket.recv() - # response = self._socket.recv() - # msg = "Received reply for '{0}' -> '{1}'" - # msg = msg.format(request, response) - # logger.debug(msg) - except zmq.error.Again as e: - msg = "Timeout error contacting backend. {0!r}".format(e) + poll = zmq.Poller() + poll.register(self._socket, zmq.POLLIN) + + reply = None + tries = 0 + + while True: + socks = dict(poll.poll(self.POLL_TIMEOUT)) + if socks.get(self._socket) == zmq.POLLIN: + reply = self._socket.recv() + break + + tries += 1 + if tries < self.POLL_TRIES: + logger.warning('Retrying receive... {0}/{1}'.format( + tries, self.POLL_TRIES)) + else: + break + + if reply is None: + msg = "Timeout error contacting backend." logger.critical(msg) + self.online = False + else: + # msg = "Received reply for '{0}' -> '{1}'".format(request, reply) + # logger.debug(msg) + self.online = True + # request received, no ping needed for other interval. + self._reset_ping() def __getattribute__(self, name): """ |