def acquire_network_resources(self):
"""
Configure a network connection to the server.
The resulting socket is handled by two instances of
ServerConnectionReader and ServerConnectionWriter, which are
created and run as well. It is possibile to send/receive
message to/from them through the queues self.output_message_queue
and self._input_queue (servermessage).
Note: this private method should be actually "protected" for
the ServerSession states, but Python doesn't have such a
protection level.
"""
try:
self.logger.debug(u"Creating a socket on %s:%s", self.host,
self.port)
sock = socket.create_connection((self.host, self.port), timeout=10)
ca_chain = os.path.abspath(self.server_certificate)
self.sock = ssl.wrap_socket(sock,
cert_reqs=ssl.CERT_REQUIRED,
ca_certs=ca_chain,
ssl_version=ssl.PROTOCOL_TLSv1)
self.sock.setblocking(True)
match_hostname(self.sock.getpeercert(), self.host)
except CertificateError as e:
self.logger.critical(u"SSL certificate validation failed: %s" % e)
raise ssl.SSLError(e)
except socket.error as exception:
self.logger.debug(u"Error opening SSL socket: %s" % exception)
self.logger.warning(
u"Unable to connect, re-trying in %s seconds." %
self.reconnection_time)
self.reconnection_time = stoppable_exponential_backoff_waiting(
self.reconnection_time, self.must_die, 10)
self.num_connection_attempts += 1
return False
except socket.timeout as exception:
self.logger.debug(u"Socket timeout: %s" % exception)
self.logger.warning(
u"Unable to connect, re-trying in %s seconds." %
self.reconnection_time)
self.reconnection_time = stoppable_exponential_backoff_waiting(
self.reconnection_time, self.must_die, 10)
self.num_connection_attempts += 1
return False
self.connection_reader = ServerConnectionReader(
self._input_queue, self.input_keepalive_queue, self.sock)
self.connection_writer = ServerConnectionWriter(
self._input_queue, self.output_message_queue, self.sock)
self.connection_reader.start()
self.connection_writer.start()
self.reconnection_time = 1
return True
