Refactor provider_bootstrapper out of mainwindow

1 files changed, 381 insertions, 0 deletions

diff --git a/src/leap/bitmask/backend.py b/src/leap/bitmask/backend.py
new file mode 100644
index 00000000..8a289a79
--- /dev/null
+++ b/src/leap/bitmask/backend.py
@@ -0,0 +1,381 @@
+# -*- coding: utf-8 -*-
+# backend.py
+# Copyright (C) 2013 LEAP
+#
+# 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 <http://www.gnu.org/licenses/>.
+"""
+Backend for everything
+"""
+import logging
+import os
+
+from Queue import Queue, Empty
+
+from twisted.internet import threads, defer
+from twisted.internet.task import LoopingCall
+from twisted.python import log
+
+import zope.interface
+
+from leap.bitmask.config.providerconfig import ProviderConfig
+from leap.bitmask.provider.providerbootstrapper import ProviderBootstrapper
+
+# Frontend side
+from PySide import QtCore
+
+logger = logging.getLogger(__name__)
+
+
+class ILEAPComponent(zope.interface.Interface):
+    """
+    Interface that every component for the backend should comply to
+    """
+
+    key = zope.interface.Attribute("Key id for this component")
+
+
+class ILEAPService(ILEAPComponent):
+    """
+    Interface that every Service needs to implement
+    """
+
+    def start(self):
+        """
+        Starts the service.
+        """
+        pass
+
+    def stop(self):
+        """
+        Stops the service.
+        """
+        pass
+
+    def terminate(self):
+        """
+        Terminates the service, not necessarily in a nice way.
+        """
+        pass
+
+    def status(self):
+        """
+        Returns a json object with the current status for the service.
+
+        :rtype: object (list, str, dict)
+        """
+        # XXX: Use a namedtuple or a specific object instead of a json
+        # object, since parsing it will be problematic otherwise.
+        # It has to be something easily serializable though.
+        pass
+
+    def set_configs(self, keyval):
+        """
+        Sets the config parameters for this Service.
+
+        :param keyval: values to configure
+        :type keyval: dict, {str: str}
+        """
+        pass
+
+    def get_configs(self, keys):
+        """
+        Returns the configuration values for the list of keys.
+
+        :param keys: keys to retrieve
+        :type keys: list of str
+
+        :rtype: dict, {str: str}
+        """
+        pass
+
+
+class Provider(object):
+    """
+    Interfaces with setup and bootstrapping operations for a provider
+    """
+
+    zope.interface.implements(ILEAPComponent)
+
+    PROBLEM_SIGNAL = "prov_problem_with_provider"
+
+    def __init__(self, signaler=None, bypass_checks=False):
+        """
+        Constructor for the Provider component
+
+        :param signaler: Object in charge of handling communication
+                         back to the frontend
+        :type signaler: Signaler
+        :param bypass_checks: Set to true if the app should bypass
+                              first round of checks for CA
+                              certificates at bootstrap
+        :type bypass_checks: bool
+        """
+        object.__init__(self)
+        self.key = "provider"
+        self._provider_bootstrapper = ProviderBootstrapper(signaler,
+                                                           bypass_checks)
+        self._download_provider_defer = None
+        self._provider_config = ProviderConfig()
+
+    def setup_provider(self, provider):
+        """
+        Initiates the setup for a provider
+
+        :param provider: URL for the provider
+        :type provider: unicode
+        """
+        log.msg("Setting up provider %s..." % (provider.encode("idna"),))
+        pb = self._provider_bootstrapper
+        d = pb.run_provider_select_checks(provider, download_if_needed=True)
+        self._download_provider_defer = d
+        return d
+
+    def bootstrap(self, provider):
+        """
+        Second stage of bootstrapping for a provider.
+
+        :param provider: URL for the provider
+        :type provider: unicode
+        """
+
+        d = None
+
+        # If there's no loaded provider or
+        # we want to connect to other provider...
+        if (not self._provider_config.loaded() or
+                self._provider_config.get_domain() != provider):
+            self._provider_config.load(
+                os.path.join("leap", "providers",
+                             provider, "provider.json"))
+
+        if self._provider_config.loaded():
+            d = self._provider_bootstrapper.run_provider_setup_checks(
+                self._provider_config,
+                download_if_needed=True)
+        else:
+            if self._signaler is not None:
+                self._signaler.signal(self.PROBLEM_SIGNAL)
+            logger.error("Could not load provider configuration.")
+            self._login_widget.set_enabled(True)
+
+        if d is None:
+            d = defer.Deferred()
+        return d
+
+
+class Signaler(QtCore.QObject):
+    """
+    Signaler object, handles converting string commands to Qt signals.
+
+    This is intended for the separation in frontend/backend, this will
+    live in the frontend.
+    """
+
+    # Signals for the ProviderBootstrapper
+    # These will only exist in the frontend
+    prov_name_resolution = QtCore.Signal(object)
+    prov_https_connection = QtCore.Signal(object)
+    prov_download_provider_info = QtCore.Signal(object)
+
+    prov_download_ca_cert = QtCore.Signal(object)
+    prov_check_ca_fingerprint = QtCore.Signal(object)
+    prov_check_api_certificate = QtCore.Signal(object)
+
+    prov_problem_with_provider = QtCore.Signal(object)
+
+    # These will exist both in the backend and the front end.
+    # The frontend might choose to not "interpret" all the signals
+    # from the backend, but the backend needs to have all the signals
+    # it's going to emit defined here
+    PROV_NAME_RESOLUTION_KEY = "prov_name_resolution"
+    PROV_HTTPS_CONNECTION_KEY = "prov_https_connection"
+    PROV_DOWNLOAD_PROVIDER_INFO_KEY = "prov_download_provider_info"
+    PROV_DOWNLOAD_CA_CERT_KEY = "prov_download_ca_cert"
+    PROV_CHECK_CA_FINGERPRINT_KEY = "prov_check_ca_fingerprint"
+    PROV_CHECK_API_CERTIFICATE_KEY = "prov_check_api_certificate"
+    PROV_PROV_PROBLEM_WITH_PROVIER_KEY = "prov_problem_with_provider"
+
+    def __init__(self):
+        """
+        Constructor for the Signaler
+        """
+        QtCore.QObject.__init__(self)
+        self._signals = {}
+
+        signals = [
+            self.PROV_NAME_RESOLUTION_KEY,
+            self.PROV_HTTPS_CONNECTION_KEY,
+            self.PROV_DOWNLOAD_PROVIDER_INFO_KEY,
+            self.PROV_DOWNLOAD_CA_CERT_KEY,
+            self.PROV_CHECK_CA_FINGERPRINT_KEY,
+            self.PROV_CHECK_API_CERTIFICATE_KEY,
+            self.PROV_PROV_PROBLEM_WITH_PROVIER_KEY
+        ]
+
+        for sig in signals:
+            self._signals[sig] = getattr(self, sig)
+
+    def signal(self, key, data=None):
+        """
+        Emits a Qt signal based on the key provided, with the data if provided.
+
+        :param key: string identifying the signal to emit
+        :type key: str
+        :param data: object to send with the data
+        :type data: object
+
+        NOTE: The data object will be a serialized str in the backend,
+        and an unserialized object in the frontend, but for now we
+        just care about objects.
+        """
+        # Right now it emits Qt signals. The backend version of this
+        # will do zmq.send_multipart, and the frontend version will be
+        # similar to this
+        log.msg("Signaling %s :: %s" % (key, data))
+        try:
+            self._signals[key].emit(data)
+        except KeyError:
+            log.msg("Unknown key for signal %s!" % (key,))
+
+
+class Backend(object):
+    """
+    Backend for everything, the UI should only use this class.
+    """
+
+    PASSED_KEY = "passed"
+    ERROR_KEY = "error"
+
+    def __init__(self, bypass_checks=False):
+        """
+        Constructor for the backend.
+        """
+        object.__init__(self)
+
+        # Components map for the commands received
+        self._components = {}
+
+        # Ongoing defers that will be cancelled at stop time
+        self._ongoing_defers = []
+
+        # Signaler object to translate commands into Qt signals
+        self._signaler = Signaler()
+
+        # Component registration
+        self._register(Provider(self._signaler, bypass_checks))
+
+        # We have a looping call on a thread executing all the
+        # commands in queue. Right now this queue is an actual Queue
+        # object, but it'll become the zmq recv_multipart queue
+        self._lc = LoopingCall(threads.deferToThread, self._worker)
+
+        # Temporal call_queue for worker, will be replaced with
+        # recv_multipart os something equivalent in the loopingcall
+        self._call_queue = Queue()
+
+    @property
+    def signaler(self):
+        """
+        Public signaler access to let the UI connect to its signals.
+        """
+        return self._signaler
+
+    def start(self):
+        """
+        Starts the looping call
+        """
+        log.msg("Starting worker...")
+        self._lc.start(0.01)
+
+    def stop(self):
+        """
+        Stops the looping call and tries to cancel all the defers.
+        """
+        log.msg("Stopping worker...")
+        self._lc.stop()
+        while len(self._ongoing_defers) > 0:
+            d = self._ongoing_defers.pop()
+            d.cancel()
+
+    def _register(self, component):
+        """
+        Registers a component in this backend
+
+        :param component: Component to register
+        :type component: any object that implements ILEAPComponent
+        """
+        # TODO: assert that the component implements the interfaces
+        # expected
+        try:
+            self._components[component.key] = component
+        except Exception:
+            log.msg("There was a problem registering %s" % (component,))
+            log.err()
+
+    def _signal_back(self, _, signal):
+        """
+        Helper method to signal back (callback like behavior) to the
+        UI that an operation finished.
+
+        :param signal: signal name
+        :type signal: str
+        """
+        self._signaler.signal(signal)
+
+    def _worker(self):
+        """
+        Worker method, called from a different thread and as a part of
+        a looping call
+        """
+        try:
+            # this'll become recv_multipart
+            cmd = self._call_queue.get(block=False)
+
+            # cmd is: component, method, signalback, *args
+            func = getattr(self._components[cmd[0]], cmd[1])
+            d = func(*cmd[3:])
+            # A call might not have a callback signal, but if it does,
+            # we add it to the chain
+            if cmd[2] is not None:
+                d.addCallbacks(self._signal_back, log.err, cmd[2])
+            d.addCallbacks(self._done_action, log.err,
+                           callbackKeywords={"d": d})
+            d.addErrback(log.err)
+            self._ongoing_defers.append(d)
+        except Empty:
+            # If it's just empty we don't have anything to do.
+            pass
+        except Exception:
+            # But we log the rest
+            log.err()
+
+    def _done_action(self, _, d):
+        """
+        Remover of the defer once it's done
+
+        :param d: defer to remove
+        :type d: twisted.internet.defer.Deferred
+        """
+        self._ongoing_defers.remove(d)
+
+    # XXX: Temporal interface until we migrate to zmq
+    # We simulate the calls to zmq.send_multipart. Once we separate
+    # this in two processes, the methods bellow can be changed to
+    # send_multipart and this backend class will be really simple.
+
+    def setup_provider(self, provider):
+        self._call_queue.put(("provider", "setup_provider", None, provider))
+
+    def provider_bootstrap(self, provider):
+        self._call_queue.put(("provider", "bootstrap", None, provider))