pylib/socket_protocol
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socket_protocol/__init__.py

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#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
"""
socket_protocol (Socket Protocol)
=================================
**Author:**
* Dirk Alders <sudo-dirk@mount-mockery.de>
**Description:**
This Module supports point to point communication for client-server issues.
**Submodules:**
* :class:`socket_protocol.data_storage`
* :class:`socket_protocol.pure_json_protocol`
* :class:`socket_protocol.struct_json_protocol`
**Unittest:**
See also the :download:`unittest <socket_protocol/_testresults_/unittest.pdf>` documentation.
**Module Documentation:**
"""
__DEPENDENCIES__ = ['stringtools']
import stringtools
import binascii
import hashlib
import json
import logging
import os
import struct
import sys
import time
try:
from config import APP_NAME as ROOT_LOGGER_NAME
except ImportError:
ROOT_LOGGER_NAME = 'root'
logger = logging.getLogger(ROOT_LOGGER_NAME).getChild(__name__)
__DESCRIPTION__ = """The Module {\\tt %s} is designed for point to point communication for client-server issues.
For more Information read the sphinx documentation.""" % __name__.replace('_', '\_')
"""The Module Description"""
__INTERPRETER__ = (2, 3)
"""The Tested Interpreter-Versions"""
SID_AUTH_REQUEST = 0
"""SID for authentification request"""
SID_AUTH_RESPONSE = 1
"""SID for authentification response"""
DID_AUTH_SEED = 0
"""DID for authentification (seed)"""
DID_AUTH_KEY = 1
"""DID for authentification (key)"""
SID_CHANNEL_NAME_REQUEST = 8
"""SID for channel name exchange request """
SID_CHANNEL_NAME_RESPONSE = 9
"""SID for channel name exchange response"""
DID_CHANNEL_NAME = 0
"""DID for channel name """
SID_READ_REQUEST = 10
"""SID for a read data request"""
SID_READ_RESPONSE = 11
"""SID for read data response"""
SID_WRITE_REQUEST = 20
"""SID for a write data request"""
SID_WRITE_RESPONSE = 21
"""SID for a write data response"""
SID_EXECUTE_REQUEST = 30
"""SID for a execute request"""
SID_EXECUTE_RESPONSE = 31
"""SID for a execute response"""
STATUS_OKAY = 0
"""Status for 'okay'"""
STATUS_BUFFERING_UNHANDLED_REQUEST = 1
"""Status for 'unhandled request'"""
STATUS_CALLBACK_ERROR = 2
"""Status for 'callback errors'"""
STATUS_AUTH_REQUIRED = 3
"""Status for 'authentification is required'"""
STATUS_SERVICE_OR_DATA_UNKNOWN = 4
"""Status for 'service or data unknown'"""
STATUS_CHECKSUM_ERROR = 5
"""Status for 'checksum error'"""
STATUS_OPERATION_NOT_PERMITTED = 6
"""Status for 'operation not permitted'"""
STATUS_LOG_LVL = {
STATUS_OKAY: logging.INFO,
STATUS_BUFFERING_UNHANDLED_REQUEST: logging.WARNING,
STATUS_CALLBACK_ERROR: logging.ERROR,
STATUS_AUTH_REQUIRED: logging.WARNING,
STATUS_SERVICE_OR_DATA_UNKNOWN: logging.ERROR,
STATUS_CHECKSUM_ERROR: logging.ERROR,
STATUS_OPERATION_NOT_PERMITTED: logging.WARNING,
}
"""Status depending log level for messages"""
AUTH_STATE_UNTRUSTED_CONNECTION = 0
"""Authentification Status for an 'Untrusted Connection'"""
AUTH_STATE_SEED_REQUESTED = 1
"""Authentification Status for 'Seed was requested'"""
AUTH_STATE_SEED_TRANSFERRED = 2
"""Authentification Status for 'Seed has been sent'"""
AUTH_STATE_KEY_TRANSFERRED = 3
"""Authentification Status for 'Key has been sent'"""
AUTH_STATE_TRUSTED_CONNECTION = 4
"""Authentification Status for a 'Trusted Connection'"""
AUTH_STATE__NAMES = {AUTH_STATE_UNTRUSTED_CONNECTION: 'Untrusted Connection',
AUTH_STATE_SEED_REQUESTED: 'Seed was requested',
AUTH_STATE_SEED_TRANSFERRED: 'Seed has been sent',
AUTH_STATE_KEY_TRANSFERRED: 'Key has been sent',
AUTH_STATE_TRUSTED_CONNECTION: 'Trusted Connection'}
"""Authentification Status names for previous defined authentification states"""
class RequestSidExistsError(Exception):
pass
class ResponseSidExistsError(Exception):
pass
class _callback_storage(dict):
DEFAULT_CHANNEL_NAME = 'all_others'
def __init__(self, channel_name, log_prefix):
self.init_channel_name(channel_name)
self.__log_prefix__ = log_prefix
dict.__init__(self)
def init_channel_name(self, channel_name):
if channel_name is None:
self.logger = logging.getLogger(ROOT_LOGGER_NAME).getChild(__name__ + '.' + self.DEFAULT_CHANNEL_NAME)
else:
self.logger = logging.getLogger(ROOT_LOGGER_NAME).getChild(__name__ + '.' + channel_name)
def get(self, service_id, data_id):
if dict.get(self, service_id, {}).get(data_id, None) is not None:
return self[service_id][data_id]
elif dict.get(self, service_id, {}).get(None, None) is not None:
return self[service_id][None]
elif dict.get(self, None, {}).get(data_id, None) is not None:
return self[None][data_id]
elif dict.get(self, None, {}).get(None, None) is not None:
return self[None][None]
else:
return (None, None, None)
def add(self, service_id, data_id, callback, *args, **kwargs):
cb_data = self.get(service_id, data_id)
if dict.get(self, service_id, {}).get(data_id, None) is not None:
if callback is None:
self.logger.warning("%s Deleting existing callback %s for service_id (%s) and data_id (%s)!", self.__log_prefix__(), repr(cb_data[0].__name__), repr(service_id), repr(data_id))
del(self[service_id][data_id])
return
else:
self.logger.warning("%s Overwriting existing callback %s for service_id (%s) and data_id (%s) to %s!", self.__log_prefix__(), repr(cb_data[0].__name__), repr(service_id), repr(data_id), repr(callback.__name__))
else:
self.logger.debug("%s Adding callback %s for SID=%s and DID=%s", self.__log_prefix__(), repr(callback.__name__), repr(service_id), repr(data_id))
if service_id not in self:
self[service_id] = {}
self[service_id][data_id] = (callback, args, kwargs)
class data_storage(dict):
"""
This is a storage object for socket_protocol messages.
:param status: The message status.
:type status: int
:param service_id: The Service-ID.
:type service_id: int
:param data_id: The Data-ID.
:type data_id: int
:param data: The transfered data.
:type data: any
"""
KEY_STATUS = 'status'
KEY_SERVICE_ID = 'service_id'
KEY_DATA_ID = 'data_id'
KEY_DATA = 'data'
ALL_KEYS = [KEY_DATA, KEY_DATA_ID, KEY_SERVICE_ID, KEY_STATUS]
def __init__(self, *args, **kwargs):
dict.__init__(self, *args, **kwargs)
for key in self.ALL_KEYS:
if key not in self:
self[key] = None
def get_status(self, default=None):
"""
This Method returns the message status.
:param default: The default value, if no data is available.
"""
return self.get(self.KEY_STATUS, default)
def get_service_id(self, default=None):
"""
This Method returns the message Service-ID.
:param default: The default value, if no data is available.
"""
return self.get(self.KEY_SERVICE_ID, default)
def get_data_id(self, default=None):
"""
This Method returns the message Data-ID.
:param default: The default value, if no data is available.
"""
return self.get(self.KEY_DATA_ID, default)
def get_data(self, default=None):
"""
This Method returns the message data.
:param default: The default value, if no data is available.
"""
return self.get(self.KEY_DATA, default)
class pure_json_protocol(object):
"""
This `class` supports to transfer a message and it's data.
:param comm_instance: A communication instance.
:type comm_instance: instance
:param secret: An optinal secret (e.g. created by ``binascii.hexlify(os.urandom(24))``).
:type secret: str
:param auto_auth: An optional parameter to enable (True) automatic authentification, otherwise you need to do it manually, if needed.
:type auto_auth: bool
:param channel_name: An optional parameter to set a channel name for logging of the communication.
:type channel_name: str
.. hint::
* The Service-ID is designed to identify the type of the communication (e.g. :const:`READ_REQUEST`, :const:`WRITE_REQUEST`, :const:`READ_RESPONSE`, :const:`WRITE_RESPONSE`, ...)
* The Data-ID is designed to identify the requests / responses using the same Service_ID.
.. note:: The :class:`comm_instance` needs to have at least the following interface:
* A Method :func:`comm_instance.init_channel_name` to set the channel name.
* A Constant :const:`comm_instance.IS_CLIENT` to identify that the :class:`comm_instance` is a client (True) or a server (False).
* A Method :func:`comm_instance.is_connected` to identify if the instance is connected (True) or not (False).
* A Method :func:`comm_instance.reconnect` to initiate a reconnect.
* A Method :func:`comm_instance.register_callback` to register a data available callback.
* A Method :func:`comm_instance.register_connect_callback` to register a connect callback.
* A Method :func:`comm_instance.register_disconnect_callback` to register a disconnect callback.
* A Method :func:`comm_instance.send` to send data via the :class:`comm_instance`.
.. note:: The parameter :const:`auto_auth` is only relevant, if a secret is given and the :class:`comm_instance` is a client. The authentification is initiated directly after the connection is established.
.. note:: The :const:`channel_name`-exchange will be initiated by the client directly after the the connection is established.
* If a channel_name is given at both communication sides and they are different, the client name is taken over and the server will log a warning message.
"""
DEFAULT_CHANNEL_NAME = 'all_others'
def __init__(self, comm_instance, secret=None, auto_auth=False, channel_name=None):
self.__comm_inst__ = comm_instance
self.__secret__ = secret
self.__auto_auth__ = auto_auth
#
self.__auth_whitelist__ = {}
self.__sid_response_dict__ = {}
self.__sid_name_dict__ = {}
self.__did_name_dict__ = {}
#
self.__status_name_dict = {}
self.add_status(STATUS_OKAY, 'okay')
self.add_status(STATUS_BUFFERING_UNHANDLED_REQUEST, 'no callback for service, data buffered')
self.add_status(STATUS_CALLBACK_ERROR, 'callback error')
self.add_status(STATUS_AUTH_REQUIRED, 'authentification required')
self.add_status(STATUS_SERVICE_OR_DATA_UNKNOWN, 'service or data unknown')
self.add_status(STATUS_CHECKSUM_ERROR, 'checksum error')
self.add_status(STATUS_OPERATION_NOT_PERMITTED, 'operation not permitted')
#
self.__callbacks__ = _callback_storage(channel_name, self.__log_prefix__)
self.__init_channel_name__(channel_name)
#
self.__clean_receive_buffer__()
self.add_service(SID_AUTH_REQUEST, SID_AUTH_RESPONSE, 'authentification request', 'authentification response')
self.add_data((SID_AUTH_REQUEST, SID_AUTH_RESPONSE), DID_AUTH_SEED, 'seed')
self.add_data(SID_AUTH_REQUEST, DID_AUTH_KEY, 'key')
self.add_data(SID_AUTH_RESPONSE, DID_AUTH_KEY, 'key')
self.add_msg_to_auth_whitelist_(SID_AUTH_REQUEST, DID_AUTH_SEED)
self.add_msg_to_auth_whitelist_(SID_AUTH_RESPONSE, DID_AUTH_SEED)
self.add_msg_to_auth_whitelist_(SID_AUTH_REQUEST, DID_AUTH_KEY)
self.add_msg_to_auth_whitelist_(SID_AUTH_RESPONSE, DID_AUTH_KEY)
self.__callbacks__.add(SID_AUTH_REQUEST, DID_AUTH_SEED, self.__authentificate_create_seed__)
self.__callbacks__.add(SID_AUTH_RESPONSE, DID_AUTH_SEED, self.__authentificate_create_key__)
self.__callbacks__.add(SID_AUTH_REQUEST, DID_AUTH_KEY, self.__authentificate_check_key__)
self.__callbacks__.add(SID_AUTH_RESPONSE, DID_AUTH_KEY, self.__authentificate_process_feedback__)
self.__authentification_state_reset__()
self.add_service(SID_CHANNEL_NAME_REQUEST, SID_CHANNEL_NAME_RESPONSE, 'channel name request', 'channel name response')
self.add_data((SID_CHANNEL_NAME_REQUEST, SID_CHANNEL_NAME_RESPONSE), DID_CHANNEL_NAME, 'name')
self.add_msg_to_auth_whitelist_(SID_CHANNEL_NAME_REQUEST, DID_CHANNEL_NAME)
self.add_msg_to_auth_whitelist_(SID_CHANNEL_NAME_RESPONSE, DID_CHANNEL_NAME)
self.__callbacks__.add(SID_CHANNEL_NAME_REQUEST, DID_CHANNEL_NAME, self.__channel_name_request__)
self.__callbacks__.add(SID_CHANNEL_NAME_RESPONSE, DID_CHANNEL_NAME, self.__channel_name_response__)
self.add_service(SID_READ_REQUEST, SID_READ_RESPONSE, 'read data request', 'read data response')
self.add_service(SID_WRITE_REQUEST, SID_WRITE_RESPONSE, 'write data request', 'write data response')
self.add_service(SID_EXECUTE_REQUEST, SID_EXECUTE_RESPONSE, 'execute request', 'execute response')
self.__seed__ = None
self.__comm_inst__.register_callback(self.__data_available_callback__)
self.__comm_inst__.register_connect_callback(self.__connection_established__)
self.__comm_inst__.register_disconnect_callback(self.__authentification_state_reset__)
logger.info('%s Initialisation finished.', self.__log_prefix__())
def __analyse_frame__(self, frame):
if sys.version_info >= (3, 0):
return data_storage(json.loads(frame[:-4].decode('utf-8')))
else:
return data_storage(json.loads(frame[:-4]))
def __authentificate_check_key__(self, msg):
key = msg.get_data()
if key == self.__authentificate_salt_and_hash__(self.__seed__):
self.__authentification_state__ = AUTH_STATE_TRUSTED_CONNECTION
return STATUS_OKAY, True
else:
self.__authentification_state__ = AUTH_STATE_UNTRUSTED_CONNECTION
return STATUS_OKAY, False
def __authentificate_create_key__(self, msg):
self.__authentification_state__ = AUTH_STATE_KEY_TRANSFERRED
seed = msg.get_data()
key = self.__authentificate_salt_and_hash__(seed)
self.send(SID_AUTH_REQUEST, DID_AUTH_KEY, key)
def __authentificate_create_seed__(self, msg):
self.__authentification_state__ = AUTH_STATE_SEED_TRANSFERRED
if sys.version_info >= (3, 0):
self.__seed__ = binascii.hexlify(os.urandom(32)).decode('utf-8')
else:
self.__seed__ = binascii.hexlify(os.urandom(32))
return STATUS_OKAY, self.__seed__
def __authentificate_process_feedback__(self, msg):
feedback = msg.get_data()
if feedback:
self.__authentification_state__ = AUTH_STATE_TRUSTED_CONNECTION
self.logger.info("%s Got positive authentification feedback", self.__log_prefix__())
else:
self.__authentification_state__ = AUTH_STATE_UNTRUSTED_CONNECTION
self.logger.warning("%s Got negative authentification feedback", self.__log_prefix__())
return STATUS_OKAY, None
def __authentificate_salt_and_hash__(self, seed):
if sys.version_info >= (3, 0):
return hashlib.sha512(bytes(seed, 'utf-8') + self.__secret__).hexdigest()
else:
return hashlib.sha512(seed.encode('utf-8') + self.__secret__.encode('utf-8')).hexdigest()
def __authentification_state_reset__(self):
self.logger.info("%s Resetting authentification state to AUTH_STATE_UNTRUSTED_CONNECTION", self.__log_prefix__())
self.__authentification_state__ = AUTH_STATE_UNTRUSTED_CONNECTION
def __authentification_required__(self, service_id, data_id):
return data_id not in self.__auth_whitelist__.get(service_id, [])
def __buffer_received_data__(self, msg):
if not msg.get_service_id() in self.__msg_buffer__:
self.__msg_buffer__[msg.get_service_id()] = {}
if not msg.get_data_id() in self.__msg_buffer__[msg.get_service_id()]:
self.__msg_buffer__[msg.get_service_id()][msg.get_data_id()] = []
self.__msg_buffer__[msg.get_service_id()][msg.get_data_id()].append(msg)
self.logger.debug("%s Message data is stored in buffer and is now ready to be retrieved by receive method", self.__log_prefix__())
def __build_frame__(self, msg):
data_frame = json.dumps(self.__mk_msg__(msg.get_status(), msg.get_service_id(), msg.get_data_id(), msg.get_data()))
if sys.version_info >= (3, 0):
data_frame = bytes(data_frame, 'utf-8')
checksum = self.__calc_chksum__(data_frame)
return data_frame + checksum
def __calc_chksum__(self, raw_data):
return struct.pack('>I', binascii.crc32(raw_data) & 0xffffffff)
@property
def __channel_name__(self):
cn = self.logger.name.split('.')[-1]
if cn != self.DEFAULT_CHANNEL_NAME:
return cn
def __channel_name_response__(self, msg):
data = msg.get_data()
if self.__channel_name__ is None and data is not None:
self.__init_channel_name__(data)
self.logger.info('%s channel name is now %s', self.__log_prefix__(), repr(self.__channel_name__))
return STATUS_OKAY, None
def __channel_name_request__(self, msg):
data = msg.get_data()
if data is None:
return STATUS_OKAY, self.__channel_name__
else:
prev_channel_name = self.__channel_name__
self.__init_channel_name__(data)
if prev_channel_name is not None and prev_channel_name != data:
self.logger.warning('%s overwriting user defined channel name from %s to %s', self.__log_prefix__(), repr(prev_channel_name), repr(data))
elif prev_channel_name is None:
self.logger.info('%s channel name is now %s', self.__log_prefix__(), repr(self.__channel_name__))
return STATUS_OKAY, None
def __check_frame_checksum__(self, frame):
return self.__calc_chksum__(frame[:-4]) == frame[-4:]
def __clean_receive_buffer__(self):
self.logger.debug("%s Cleaning up receive-buffer", self.__log_prefix__())
self.__msg_buffer__ = {}
def __connection_established__(self):
self.__clean_receive_buffer__()
if self.__comm_inst__.IS_CLIENT:
self.send(SID_CHANNEL_NAME_REQUEST, 0, self.__channel_name__)
if self.__auto_auth__ and self.__comm_inst__.IS_CLIENT and self.__secret__ is not None:
self.authentificate()
def __log_msg__(self, msg, rx_tx_prefix):
self.logger.log(
self.__status_log_lvl__(msg.get_status()),
'%s %s %s, %s, data: "%s"',
self.__log_prefix__(),
rx_tx_prefix,
self.__get_message_name__(msg.get_service_id(), msg.get_data_id()),
self.__get_status_name__(msg.get_status()),
repr(msg.get_data())
)
def __data_available_callback__(self, comm_inst):
frame = comm_inst.receive()
msg = self.__analyse_frame__(frame)
if not self.__check_frame_checksum__(frame):
# Wrong Checksum
self.logger.log(self.__status_log_lvl__(STATUS_CHECKSUM_ERROR), "%s Received message has an invalid checksum. Message will be ignored.", self.__log_prefix__())
return # No response needed
elif not self.check_authentification_state() and self.__authentification_required__(msg.get_service_id(), msg.get_data_id()):
# Authentification required
self.__log_msg__(msg, 'RX <-')
if msg.get_service_id() in self.__sid_response_dict__.keys():
self.logger.log(self.__status_log_lvl__(STATUS_AUTH_REQUIRED), "%s Authentification is required. Just sending negative response.", self.__log_prefix__())
status = STATUS_AUTH_REQUIRED
data = None
else:
self.logger.log(self.__status_log_lvl__(STATUS_AUTH_REQUIRED), "%s Authentification is required. Incomming message will be ignored.", self.__log_prefix__())
return # No response needed
else:
# Valid message
self.__log_msg__(msg, 'RX <-')
callback, args, kwargs = self.__callbacks__.get(msg.get_service_id(), msg.get_data_id())
if msg.get_service_id() in self.__sid_response_dict__.keys():
#
# REQUEST RECEIVED
#
if callback is None:
self.logger.warning("%s Incomming message with no registered callback. Sending negative response.", self.__log_prefix__())
status = STATUS_BUFFERING_UNHANDLED_REQUEST
data = None
else:
self.logger.debug("%s Executing callback %s to process received data", self.__log_prefix__(), callback.__name__)
try:
status, data = callback(msg, *args, **kwargs)
except Exception as e:
logger.error('{lp} Exception raised. Check callback {callback_name}: "{message}" and it\'s return values for {msg_info}'.format(lp=self.__log_prefix__(), callback_name=callback.__name__, message=str(e), msg_info=self.__get_message_name__(msg.get_service_id(), msg.get_data_id())))
status = STATUS_CALLBACK_ERROR
data = None
else:
#
# RESPONSE RECEIVED
#
if callback is None:
self.__buffer_received_data__(msg)
else:
self.logger.debug("%s Executing callback %s to process received data", self.__log_prefix__(), callback.__name__)
try:
callback(msg, *args, **kwargs)
except Exception as e:
logger.error('{lp} Exception raised. Check callback {callback_name}: "{message}" for {msg_info}'.format(lp=self.__log_prefix__(), callback_name=callback.__name__, message=str(e), msg_info=self.__get_message_name__(msg.get_service_id(), msg.get_data_id())))
return # No response needed
self.send(self.__sid_response_dict__[msg.get_service_id()], msg.get_data_id(), data, status=status)
def __get_message_name__(self, service_id, data_id):
return 'service: %s, data_id: %s' % (
self.__sid_name_dict__.get(service_id, repr(service_id)),
self.__did_name_dict__.get(service_id, {}).get(data_id, repr(data_id)),
)
def __get_status_name__(self, status):
return 'status: %s' % (self.__status_name_dict.get(status, 'unknown status: %s' % repr(status)))
def __init_channel_name__(self, channel_name):
self.__comm_inst__.init_channel_name(channel_name)
self.__callbacks__.init_channel_name(channel_name)
if channel_name is None:
self.logger = logging.getLogger(ROOT_LOGGER_NAME).getChild(__name__ + '.' + self.DEFAULT_CHANNEL_NAME)
else:
self.logger = logging.getLogger(ROOT_LOGGER_NAME).getChild(__name__ + '.' + channel_name)
def __log_prefix__(self):
return 'prot-client:' if self.__comm_inst__.IS_CLIENT else 'prot-server:'
def __mk_msg__(self, status, service_id, data_id, data):
return data_storage({data_storage.KEY_DATA_ID: data_id, data_storage.KEY_SERVICE_ID: service_id, data_storage.KEY_STATUS: status, data_storage.KEY_DATA: data})
def __status_log_lvl__(self, status):
return STATUS_LOG_LVL.get(status, logging.CRITICAL)
def add_data(self, service_id, data_id, name):
"""
Method to add a name for a specific message.
:param service_id: The Service-ID of the message. See class definitions starting with ``SID_``.
:type service_id: int or list of ints
:param data_id: The Data-ID of the message.
:type data_id: int
:param name: The Name for the transfered message.
:type name: str
"""
try:
iter(service_id)
except Exception:
service_id = (service_id, )
for sid in service_id:
if sid not in self.__did_name_dict__:
self.__did_name_dict__[sid] = {}
self.__did_name_dict__[sid][data_id] = name
def add_msg_to_auth_whitelist_(self, service_id, data_id):
"""
Method to add a specific message to the list, where no authentification is required.
:param service_id: The Service-ID of the message. See class definitions starting with ``SID_``.
:type service_id: int
:param data_id: The Data-ID of the message.
:type data_id: int
"""
if service_id not in self.__auth_whitelist__:
self.__auth_whitelist__[service_id] = []
self.__auth_whitelist__[service_id].append(data_id)
logger.debug('%s Adding Message (%s) to the authentification whitelist', self.__log_prefix__(), self.__get_message_name__(service_id, data_id))
def add_service(self, req_sid, resp_sid, req_name=None, resp_name=None):
"""
Method to add a Service defined by Request- and Response Serivce-ID.
:param req_sid: The Request Service-ID.
:type req_sid: int
:param resp_sid: The Response Service-ID.
:type resp_sid: int
"""
if req_sid in self.__sid_response_dict__:
logger.error('%s Service with Request-SID=%d and Response-SID=%d not added, because request SID is already registered', self.__log_prefix__(), req_sid, resp_sid)
raise RequestSidExistsError("Request for this Service is already registered")
elif resp_sid in self.__sid_response_dict__.values():
logger.error('%s Service with Request-SID=%d and Response-SID=%d not added, because response SID is already registered', self.__log_prefix__(), req_sid, resp_sid)
raise ResponseSidExistsError("Response for this Service is already registered")
else:
self.__sid_response_dict__[req_sid] = resp_sid
if req_name is not None:
self.__sid_name_dict__[req_sid] = req_name
if resp_name is not None:
self.__sid_name_dict__[resp_sid] = resp_name
logger.debug('%s Adding Service with Request=%s and Response=%s', self.__log_prefix__(), req_name or repr(req_sid), resp_name or repr(resp_sid))
def add_status(self, status, name):
"""
Method to add a name for a status.
:param status: The Status. See class definitions starting with ``STATUS_``.
:type status: int
:param name: The Name for the Status.
:type name: str
"""
self.__status_name_dict[status] = name
def authentificate(self, timeout=2):
"""
This method authetificates the client at the server.
:param timeout: The timeout for the authentification (requesting seed, sending key and getting authentification_feedback).
:type timeout: float
:returns: True, if authentification was successfull; False, if not.
:rtype: bool
.. note:: An authentification will only processed, if a secret had been given on initialisation.
.. note:: Client and Server needs to use the same secret.
"""
if self.__secret__ is not None:
self.__authentification_state__ = AUTH_STATE_SEED_REQUESTED
self.send(SID_AUTH_REQUEST, DID_AUTH_SEED, None)
cnt = 0
while cnt < timeout * 10:
time.sleep(0.1)
if self.__authentification_state__ == AUTH_STATE_TRUSTED_CONNECTION:
return True
elif self.__authentification_state__ == AUTH_STATE_UNTRUSTED_CONNECTION:
break
cnt += 1
return False
def check_authentification_state(self):
"""
This Method return the Authitification State as boolean value.
:return: True, if authentification state is okay, otherwise False
:rtype: bool
"""
return self.__secret__ is None or self.__authentification_state__ == AUTH_STATE_TRUSTED_CONNECTION
def connection_established(self):
"""
This Method returns the Connection state including authentification as a boolean value.
:return: True, if the connection is established (incl. authentification, if a secret has been given)
:rtype: bool
"""
return self.is_connected() and (self.__secret__ is None or self.check_authentification_state())
def is_connected(self):
"""
This Methods returns Connection state of the Communication Instance :func:`comm_instance.is_connected`.
:return: True if the :class:`comm_instance` is connected, otherwise False..
:rtype: bool
"""
return self.__comm_inst__.is_connected()
def receive(self, service_id, data_id, timeout=1):
"""
This Method returns a message object for a defined message or None, if this message is not available after the given timout.
:param service_id: The Service-ID for the message. See class definitions starting with ``SID_``.
:type service_id: int
:param data_id: The Data-ID for the message.
:type data_id: int
:param timeout: The timeout for receiving.
:type timeout: float
:returns: The received data storage object or None, if no data was received.
:rtype: data_storage
"""
data = None
cnt = 0
while data is None and cnt < timeout * 10:
try:
data = self.__msg_buffer__.get(service_id, {}).get(data_id, []).pop(0)
except IndexError:
data = None
cnt += 1
time.sleep(0.1)
if data is None and cnt >= timeout * 10:
self.logger.warning('%s TIMEOUT (%ss): Requested data (service_id: %s; data_id: %s) not in buffer.', self.__log_prefix__(), repr(timeout), repr(service_id), repr(data_id))
return data
def reconnect(self):
"""
This methods initiates a reconnect by calling :func:`comm_instance.reconnect`.
"""
return self.__comm_inst__.reconnect()
def register_callback(self, service_id, data_id, callback, *args, **kwargs):
"""
This method registers a callback for the given parameters. Giving ``None`` means, that all Service-IDs or all Data-IDs are used.
If a message hitting these parameters has been received, the callback will be executed.
:param service_id: The Service-ID for the message. See class definitions starting with ``SID_``.
:type service_id: int
:param data_id: The Data-ID for the message.
:type data_id: int
.. note:: The :func:`callback` is priorised in the following order:
* Callbacks with defined Service-ID and Data-ID.
* Callbacks with a defined Service-ID and all Data-IDs.
* Callbacks with a defined Data-ID and all Service-IDs.
* Unspecific Callbacks.
.. note:: The :func:`callback` is executed with these arguments:
**Parameters given at the callback call:**
* The first Arguments is the received message as :class:`data_storage` object.
* Further arguments given at registration.
* Further keyword arguments given at registration.
**Return value of the callback:**
If the Callback is a Request Callback for a registered Service, the return value has to be a tuple or list with
* :const:`response_status`: The response status (see class definitions starting with :const:`STA_*`.
* :const:`response_data`: A JSON iterable object to be used as data for the response.
.. note:: Only registered services will respond via the callbacks return values with the same data_id.
"""
self.__callbacks__.add(service_id, data_id, callback, *args, **kwargs)
def send(self, service_id, data_id, data, status=STATUS_OKAY, timeout=2):
"""
This methods sends out a message with the given content.
:param service_id: The Service-ID for the message. See class definitions starting with ``SERVICE_``.
:type service_id: int
:param data_id: The Data-ID for the message.
:type data_id: int
:param data: The data to be transfered. The data needs to be json compatible.
:type data: str
:param status: The Status for the message. All requests should have ``STATUS_OKAY``.
:type status: int
:param timeout: The timeout for sending data (e.g. time to establish new connection).
:type timeout: float
:return: True if data had been sent, otherwise False.
:rtype: bool
"""
if (self.check_authentification_state() or not self.__authentification_required__(service_id, data_id)) or (service_id in self.__sid_response_dict__.values() and status == STATUS_AUTH_REQUIRED and data is None):
msg = data_storage(service_id=service_id, data_id=data_id, data=data, status=status)
self.__log_msg__(msg, 'TX ->')
return self.__comm_inst__.send(self.__build_frame__(msg), timeout=timeout)
else:
# Authentification required
self.logger.warning("%s Authentification is required. TX-Message %s, %s, data: %s will be ignored.", self.__log_prefix__(), self.__get_message_name__(service_id, data_id), self.__get_status_name__(status), repr(data))
return False
class struct_json_protocol(pure_json_protocol):
"""
This Class has the same functionality like :class:`pure_json_protocol`. The message length is less than for :class:`pure_json_protocol`, but the functionality and compatibility is reduced.
See also parent :py:class:`pure_json_protocol`.
.. note::
This class is depreceated and here for compatibility reasons (to support old clients or servers). Usage of :class:`pure_json_protocol` is recommended.
"""
def __init__(self, *args, **kwargs):
pure_json_protocol.__init__(self, *args, **kwargs)
def __analyse_frame__(self, frame):
status, service_id, data_id = struct.unpack('>III', frame[0:12])
if sys.version_info >= (3, 0):
data = json.loads(frame[12:-1].decode('utf-8'))
else:
data = json.loads(frame[12:-1])
return self.__mk_msg__(status, service_id, data_id, data)
def __build_frame__(self, msg):
frame = struct.pack('>III', msg.get_status(), msg.get_service_id(), msg.get_data_id())
if sys.version_info >= (3, 0):
frame += bytes(json.dumps(msg.get_data()), 'utf-8')
frame += self.__calc_chksum__(frame)
else:
frame += json.dumps(msg.get_data())
frame += self.__calc_chksum__(frame)
return frame
def __calc_chksum__(self, raw_data):
chksum = 0
for b in raw_data:
if sys.version_info >= (3, 0):
chksum ^= b
else:
chksum ^= ord(b)
if sys.version_info >= (3, 0):
return bytes([chksum])
else:
return chr(chksum)
def __check_frame_checksum__(self, frame):
return self.__calc_chksum__(frame[:-1]) == frame[-1:]
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