diff options
Diffstat (limited to 'src/leap/bitmask/backend/backend.py')
| -rw-r--r-- | src/leap/bitmask/backend/backend.py | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/src/leap/bitmask/backend/backend.py b/src/leap/bitmask/backend/backend.py index 833f4368..37535f37 100644 --- a/src/leap/bitmask/backend/backend.py +++ b/src/leap/bitmask/backend/backend.py @@ -14,16 +14,23 @@ # # You should have received a copy of the GNU General Public License # along with this program. If not, see <http://www.gnu.org/licenses/>. + +# FIXME this is missing module documentation. It would be fine to say a couple +# of lines about the whole backend architecture. +# TODO use txzmq bindings instead. + import json import threading import time +import psutil + 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 @@ -36,15 +43,23 @@ class Backend(object): Backend server. Receives signals from backend_proxy and emit signals if needed. """ + # XXX this should not be hardcoded. Make it configurable. PORT = '5556' + + # XXX we might want to make this configurable per-platform, + # and use the most performant socket type on each one. BIND_ADDR = "tcp://127.0.0.1:%s" % PORT - def __init__(self): + PING_INTERVAL = 2 # secs + + def __init__(self, frontend_pid=None): """ Backend constructor, create needed instances. """ self._signaler = Signaler() + self._frontend_pid = frontend_pid + self._do_work = threading.Event() # used to stop the worker thread. self._zmq_socket = None @@ -61,6 +76,7 @@ class Backend(object): # Start an authenticator for this context. auth = ThreadAuthenticator(context) auth.start() + # XXX do not hardcode this here. auth.allow('127.0.0.1') # Tell authenticator to use the certificate in a directory @@ -81,6 +97,8 @@ class Backend(object): Note: we use a simple while since is less resource consuming than a Twisted's LoopingCall. """ + pid = self._frontend_pid + check_wait = 0 while self._do_work.is_set(): # Wait for next request from client try: @@ -93,6 +111,20 @@ class Backend(object): raise time.sleep(0.01) + check_wait += 0.01 + if pid is not None and check_wait > self.PING_INTERVAL: + check_wait = 0 + self._check_frontend_alive() + + def _check_frontend_alive(self): + """ + Check if the frontend is alive and stop the backend if it is not. + """ + pid = self._frontend_pid + if pid is not None and not psutil.pid_exists(pid): + logger.critical("The frontend is down!") + self.stop() + def _stop_reactor(self): """ Stop the Twisted reactor, but first wait a little for some threads to @@ -146,6 +178,10 @@ 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 |