Add base communication framework.

1 files changed, 105 insertions, 0 deletions

diff --git a/src/leap/bitmask/backend/signaler_qt.py b/src/leap/bitmask/backend/signaler_qt.py
new file mode 100644
index 00000000..cf49df91
--- /dev/null
+++ b/src/leap/bitmask/backend/signaler_qt.py
@@ -0,0 +1,105 @@
+#!/usr/bin/env python
+# encoding: utf-8
+import threading
+import time
+
+from PySide import QtCore
+
+import zmq
+from zmq.auth.thread import ThreadAuthenticator
+
+from leap.bitmask.backend.api import SIGNALS
+from leap.bitmask.backend.utils import get_frontend_certificates
+
+import logging
+logger = logging.getLogger(__name__)
+
+
+class SignalerQt(QtCore.QThread):
+    """
+    Signaling server.
+    Receives signals from the signaling client and emit Qt signals for the GUI.
+    """
+    PORT = "5667"
+    BIND_ADDR = "tcp://127.0.0.1:%s" % PORT
+
+    def __init__(self):
+        QtCore.QThread.__init__(self)
+        self._do_work = threading.Event()
+        self._do_work.set()
+
+    def run(self):
+        """
+        Start a loop to process the ZMQ requests from the signaler client.
+        """
+        logger.debug("Running SignalerQt loop")
+        context = zmq.Context()
+        socket = context.socket(zmq.REP)
+
+        # Start an authenticator for this context.
+        auth = ThreadAuthenticator(context)
+        auth.start()
+        auth.allow('127.0.0.1')
+
+        # Tell authenticator to use the certificate in a directory
+        auth.configure_curve(domain='*', location=zmq.auth.CURVE_ALLOW_ANY)
+        public, secret = get_frontend_certificates()
+        socket.curve_publickey = public
+        socket.curve_secretkey = secret
+        socket.curve_server = True  # must come before bind
+
+        socket.bind(self.BIND_ADDR)
+
+        while self._do_work.is_set():
+            # Wait for next request from client
+            try:
+                request = socket.recv(zmq.NOBLOCK)
+                logger.debug("Received request: '{0}'".format(request))
+                socket.send("OK")
+                self._process_request(request)
+            except zmq.ZMQError as e:
+                if e.errno != zmq.EAGAIN:
+                    raise
+            time.sleep(0.01)
+
+        logger.debug("SignalerQt thread stopped.")
+
+    def stop(self):
+        """
+        Stop the SignalerQt blocking loop.
+        """
+        self._do_work.clear()
+
+    def _process_request(self, request_json):
+        """
+        Process a request and call the according method with the given
+        parameters.
+
+        :param request_json: a json specification of a request.
+        :type request_json: str
+        """
+        try:
+            request = zmq.utils.jsonapi.loads(request_json)
+            signal = request['signal']
+            data = request['data']
+        except Exception as e:
+            msg = "Malformed JSON data in Signaler request '{0}'. Exc: {1!r}"
+            msg = msg.format(request_json, e)
+            logger.critical(msg)
+            raise
+
+        if signal not in SIGNALS:
+            logger.error("Unknown signal received, '{0}'".format(signal))
+            return
+
+        try:
+            qt_signal = getattr(self, signal)
+        except Exception:
+            logger.warning("Signal not implemented, '{0}'".format(signal))
+            return
+
+        logger.debug("Emitting '{0}'".format(signal))
+        if data is None:
+            qt_signal.emit()
+        else:
+            qt_signal.emit(data)