Files
uarep-ctl/modbus/pymodbus/server/sync.py

704 lines
28 KiB
Python

"""
Implementation of a Threaded Modbus Server
------------------------------------------
"""
from binascii import b2a_hex
import serial
import socket
import ssl
import traceback
from pymodbus.constants import Defaults
from pymodbus.utilities import hexlify_packets
from pymodbus.factory import ServerDecoder
from pymodbus.datastore import ModbusServerContext
from pymodbus.device import ModbusControlBlock
from pymodbus.device import ModbusDeviceIdentification
from pymodbus.transaction import *
from pymodbus.exceptions import NotImplementedException, NoSuchSlaveException
from pymodbus.pdu import ModbusExceptions as merror
from pymodbus.compat import socketserver, byte2int
# --------------------------------------------------------------------------- #
# Logging
# --------------------------------------------------------------------------- #
import logging
_logger = logging.getLogger(__name__)
# --------------------------------------------------------------------------- #
# Protocol Handlers
# --------------------------------------------------------------------------- #
class ModbusBaseRequestHandler(socketserver.BaseRequestHandler):
""" Implements the modbus server protocol
This uses the socketserver.BaseRequestHandler to implement
the client handler.
"""
running = False
framer = None
def setup(self):
""" Callback for when a client connects
"""
_logger.debug("Client Connected [%s:%s]" % self.client_address)
self.running = True
self.framer = self.server.framer(self.server.decoder, client=None)
self.server.threads.append(self)
def finish(self):
""" Callback for when a client disconnects
"""
_logger.debug("Client Disconnected [%s:%s]" % self.client_address)
self.server.threads.remove(self)
def execute(self, request):
""" The callback to call with the resulting message
:param request: The decoded request message
"""
broadcast = False
try:
if self.server.broadcast_enable and request.unit_id == 0:
broadcast = True
# if broadcasting then execute on all slave contexts, note response will be ignored
for unit_id in self.server.context.slaves():
response = request.execute(self.server.context[unit_id])
else:
context = self.server.context[request.unit_id]
response = request.execute(context)
except NoSuchSlaveException as ex:
_logger.debug("requested slave does "
"not exist: %s" % request.unit_id )
if self.server.ignore_missing_slaves:
return # the client will simply timeout waiting for a response
response = request.doException(merror.GatewayNoResponse)
except Exception as ex:
_logger.debug("Datastore unable to fulfill request: "
"%s; %s", ex, traceback.format_exc())
response = request.doException(merror.SlaveFailure)
# no response when broadcasting
if not broadcast:
response.transaction_id = request.transaction_id
response.unit_id = request.unit_id
self.send(response)
# ----------------------------------------------------------------------- #
# Base class implementations
# ----------------------------------------------------------------------- #
def handle(self):
""" Callback when we receive any data
"""
raise NotImplementedException("Method not implemented"
" by derived class")
def send(self, message):
""" Send a request (string) to the network
:param message: The unencoded modbus response
"""
raise NotImplementedException("Method not implemented "
"by derived class")
class ModbusSingleRequestHandler(ModbusBaseRequestHandler):
""" Implements the modbus server protocol
This uses the socketserver.BaseRequestHandler to implement
the client handler for a single client(serial clients)
"""
def handle(self):
""" Callback when we receive any data
"""
while self.running:
try:
data = self.request.recv(1024)
if data:
units = self.server.context.slaves()
if not isinstance(units, (list, tuple)):
units = [units]
# if broadcast is enabled make sure to process requests to address 0
if self.server.broadcast_enable:
if 0 not in units:
units.append(0)
single = self.server.context.single
self.framer.processIncomingPacket(data, self.execute,
units, single=single)
except Exception as msg:
# Since we only have a single socket, we cannot exit
# Clear frame buffer
self.framer.resetFrame()
_logger.debug("Error: Socket error occurred %s" % msg)
def send(self, message):
""" Send a request (string) to the network
:param message: The unencoded modbus response
"""
if message.should_respond:
# self.server.control.Counter.BusMessage += 1
pdu = self.framer.buildPacket(message)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('send: [%s]- %s' % (message, b2a_hex(pdu)))
return self.request.send(pdu)
class CustomSingleRequestHandler(ModbusSingleRequestHandler):
def __init__(self, request, client_address, server):
self.request = request
self.client_address = client_address
self.server = server
self.running = True
self.setup()
class ModbusConnectedRequestHandler(ModbusBaseRequestHandler):
""" Implements the modbus server protocol
This uses the socketserver.BaseRequestHandler to implement
the client handler for a connected protocol (TCP).
"""
def handle(self):
"""Callback when we receive any data, until self.running becomes False.
Blocks indefinitely awaiting data. If shutdown is required, then the
global socket.settimeout(<seconds>) may be used, to allow timely
checking of self.running. However, since this also affects socket
connects, if there are outgoing socket connections used in the same
program, then these will be prevented, if the specfied timeout is too
short. Hence, this is unreliable.
To respond to Modbus...Server.server_close() (which clears each
handler's self.running), derive from this class to provide an
alternative handler that awakens from time to time when no input is
available and checks self.running.
Use Modbus...Server( handler=... ) keyword to supply the alternative
request handler class.
"""
reset_frame = False
while self.running:
try:
units = self.server.context.slaves()
data = self.request.recv(1024)
if not data:
self.running = False
else:
if not isinstance(units, (list, tuple)):
units = [units]
# if broadcast is enabled make sure to
# process requests to address 0
if self.server.broadcast_enable:
if 0 not in units:
units.append(0)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Handling data: ' + hexlify_packets(data))
single = self.server.context.single
self.framer.processIncomingPacket(data, self.execute, units,
single=single)
except socket.timeout as msg:
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug("Socket timeout occurred %s", msg)
reset_frame = True
except socket.error as msg:
_logger.error("Socket error occurred %s" % msg)
self.running = False
except:
_logger.error("Socket exception occurred "
"%s" % traceback.format_exc() )
self.running = False
reset_frame = True
finally:
if reset_frame:
self.framer.resetFrame()
reset_frame = False
def send(self, message):
""" Send a request (string) to the network
:param message: The unencoded modbus response
"""
if message.should_respond:
# self.server.control.Counter.BusMessage += 1
pdu = self.framer.buildPacket(message)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('send: [%s]- %s' % (message, b2a_hex(pdu)))
return self.request.send(pdu)
class ModbusDisconnectedRequestHandler(ModbusBaseRequestHandler):
""" Implements the modbus server protocol
This uses the socketserver.BaseRequestHandler to implement
the client handler for a disconnected protocol (UDP). The
only difference is that we have to specify who to send the
resulting packet data to.
"""
socket = None
def handle(self):
""" Callback when we receive any data
"""
reset_frame = False
while self.running:
try:
data, self.socket = self.request
if not data:
self.running = False
data = b''
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('Handling data: ' + hexlify_packets(data))
# if not self.server.control.ListenOnly:
units = self.server.context.slaves()
single = self.server.context.single
self.framer.processIncomingPacket(data, self.execute,
units, single=single)
except socket.timeout: pass
except socket.error as msg:
_logger.error("Socket error occurred %s" % msg)
self.running = False
reset_frame = True
except Exception as msg:
_logger.error(msg)
self.running = False
reset_frame = True
finally:
# Reset data after processing
self.request = (None, self.socket)
if reset_frame:
self.framer.resetFrame()
reset_frame = False
def send(self, message):
""" Send a request (string) to the network
:param message: The unencoded modbus response
"""
if message.should_respond:
#self.server.control.Counter.BusMessage += 1
pdu = self.framer.buildPacket(message)
if _logger.isEnabledFor(logging.DEBUG):
_logger.debug('send: [%s]- %s' % (message, b2a_hex(pdu)))
return self.socket.sendto(pdu, self.client_address)
# --------------------------------------------------------------------------- #
# Server Implementations
# --------------------------------------------------------------------------- #
class ModbusTcpServer(socketserver.ThreadingTCPServer):
"""
A modbus threaded tcp socket server
We inherit and overload the socket server so that we
can control the client threads as well as have a single
server context instance.
"""
def __init__(self, context, framer=None, identity=None,
address=None, handler=None, allow_reuse_address=False,
**kwargs):
""" Overloaded initializer for the socket server
If the identify structure is not passed in, the ModbusControlBlock
uses its own empty structure.
:param context: The ModbusServerContext datastore
:param framer: The framer strategy to use
:param identity: An optional identify structure
:param address: An optional (interface, port) to bind to.
:param handler: A handler for each client session; default is
ModbusConnectedRequestHandler
:param allow_reuse_address: Whether the server will allow the
reuse of an address.
:param ignore_missing_slaves: True to not send errors on a request
to a missing slave
:param broadcast_enable: True to treat unit_id 0 as broadcast address,
False to treat 0 as any other unit_id
"""
self.threads = []
self.allow_reuse_address = allow_reuse_address
self.decoder = ServerDecoder()
self.framer = framer or ModbusSocketFramer
self.context = context or ModbusServerContext()
self.control = ModbusControlBlock()
self.address = address or ("", Defaults.Port)
self.handler = handler or ModbusConnectedRequestHandler
self.ignore_missing_slaves = kwargs.pop('ignore_missing_slaves',
Defaults.IgnoreMissingSlaves)
self.broadcast_enable = kwargs.pop('broadcast_enable',
Defaults.broadcast_enable)
if isinstance(identity, ModbusDeviceIdentification):
self.control.Identity.update(identity)
socketserver.ThreadingTCPServer.__init__(self, self.address,
self.handler,
**kwargs)
def process_request(self, request, client):
""" Callback for connecting a new client thread
:param request: The request to handle
:param client: The address of the client
"""
_logger.debug("Started thread to serve client at " + str(client))
socketserver.ThreadingTCPServer.process_request(self, request, client)
def shutdown(self):
""" Stops the serve_forever loop.
Overridden to signal handlers to stop.
"""
for thread in self.threads:
thread.running = False
socketserver.ThreadingTCPServer.shutdown(self)
def server_close(self):
""" Callback for stopping the running server
"""
_logger.debug("Modbus server stopped")
self.socket.close()
for thread in self.threads:
thread.running = False
class ModbusTlsServer(ModbusTcpServer):
"""
A modbus threaded TLS server
We inherit and overload the ModbusTcpServer so that we
can control the client threads as well as have a single
server context instance.
"""
def __init__(self, context, framer=None, identity=None,
address=None, handler=None, allow_reuse_address=False,
sslctx=None, certfile=None, keyfile=None, **kwargs):
""" Overloaded initializer for the ModbusTcpServer
If the identify structure is not passed in, the ModbusControlBlock
uses its own empty structure.
:param context: The ModbusServerContext datastore
:param framer: The framer strategy to use
:param identity: An optional identify structure
:param address: An optional (interface, port) to bind to.
:param handler: A handler for each client session; default is
ModbusConnectedRequestHandler
:param allow_reuse_address: Whether the server will allow the
reuse of an address.
:param sslctx: The SSLContext to use for TLS (default None and auto
create)
:param certfile: The cert file path for TLS (used if sslctx is None)
:param keyfile: The key file path for TLS (used if sslctx is None)
:param ignore_missing_slaves: True to not send errors on a request
to a missing slave
:param broadcast_enable: True to treat unit_id 0 as broadcast address,
False to treat 0 as any other unit_id
"""
self.sslctx = sslctx
if self.sslctx is None:
self.sslctx = ssl.create_default_context()
self.sslctx.load_cert_chain(certfile=certfile, keyfile=keyfile)
# According to MODBUS/TCP Security Protocol Specification, it is
# TLSv2 at least
self.sslctx.options |= ssl.OP_NO_TLSv1_1
self.sslctx.options |= ssl.OP_NO_TLSv1
self.sslctx.options |= ssl.OP_NO_SSLv3
self.sslctx.options |= ssl.OP_NO_SSLv2
self.sslctx.verify_mode = ssl.CERT_OPTIONAL
self.sslctx.check_hostname = False
ModbusTcpServer.__init__(self, context, framer, identity, address,
handler, allow_reuse_address, **kwargs)
def server_activate(self):
""" Callback for starting listening over TLS connection
"""
self.socket = self.sslctx.wrap_socket(self.socket, server_side=True)
socketserver.ThreadingTCPServer.server_activate(self)
class ModbusUdpServer(socketserver.ThreadingUDPServer):
"""
A modbus threaded udp socket server
We inherit and overload the socket server so that we
can control the client threads as well as have a single
server context instance.
"""
def __init__(self, context, framer=None, identity=None, address=None,
handler=None, **kwargs):
""" Overloaded initializer for the socket server
If the identify structure is not passed in, the ModbusControlBlock
uses its own empty structure.
:param context: The ModbusServerContext datastore
:param framer: The framer strategy to use
:param identity: An optional identify structure
:param address: An optional (interface, port) to bind to.
:param handler: A handler for each client session; default is
ModbusDisonnectedRequestHandler
:param ignore_missing_slaves: True to not send errors on a request
to a missing slave
:param broadcast_enable: True to treat unit_id 0 as broadcast address,
False to treat 0 as any other unit_id
"""
self.threads = []
self.decoder = ServerDecoder()
self.framer = framer or ModbusSocketFramer
self.context = context or ModbusServerContext()
self.control = ModbusControlBlock()
self.address = address or ("", Defaults.Port)
self.handler = handler or ModbusDisconnectedRequestHandler
self.ignore_missing_slaves = kwargs.pop('ignore_missing_slaves',
Defaults.IgnoreMissingSlaves)
self.broadcast_enable = kwargs.pop('broadcast_enable',
Defaults.broadcast_enable)
if isinstance(identity, ModbusDeviceIdentification):
self.control.Identity.update(identity)
socketserver.ThreadingUDPServer.__init__(self,
self.address, self.handler, **kwargs)
# self._BaseServer__shutdown_request = True
def process_request(self, request, client):
""" Callback for connecting a new client thread
:param request: The request to handle
:param client: The address of the client
"""
packet, socket = request # TODO I might have to rewrite
_logger.debug("Started thread to serve client at " + str(client))
socketserver.ThreadingUDPServer.process_request(self, request, client)
def server_close(self):
""" Callback for stopping the running server
"""
_logger.debug("Modbus server stopped")
self.socket.close()
for thread in self.threads:
thread.running = False
class ModbusSerialServer(object):
"""
A modbus threaded serial socket server
We inherit and overload the socket server so that we
can control the client threads as well as have a single
server context instance.
"""
handler = None
def __init__(self, context, framer=None, identity=None, **kwargs):
""" Overloaded initializer for the socket server
If the identify structure is not passed in, the ModbusControlBlock
uses its own empty structure.
:param context: The ModbusServerContext datastore
:param framer: The framer strategy to use
:param identity: An optional identify structure
:param port: The serial port to attach to
:param stopbits: The number of stop bits to use
:param bytesize: The bytesize of the serial messages
:param parity: Which kind of parity to use
:param baudrate: The baud rate to use for the serial device
:param timeout: The timeout to use for the serial device
:param ignore_missing_slaves: True to not send errors on a request
to a missing slave
:param broadcast_enable: True to treat unit_id 0 as broadcast address,
False to treat 0 as any other unit_id
"""
self.threads = []
self.decoder = ServerDecoder()
self.framer = framer or ModbusAsciiFramer
self.context = context or ModbusServerContext()
self.control = ModbusControlBlock()
if isinstance(identity, ModbusDeviceIdentification):
self.control.Identity.update(identity)
self.device = kwargs.get('port', 0)
self.stopbits = kwargs.get('stopbits', Defaults.Stopbits)
self.bytesize = kwargs.get('bytesize', Defaults.Bytesize)
self.parity = kwargs.get('parity', Defaults.Parity)
self.baudrate = kwargs.get('baudrate', Defaults.Baudrate)
self.timeout = kwargs.get('timeout', Defaults.Timeout)
self.ignore_missing_slaves = kwargs.get('ignore_missing_slaves',
Defaults.IgnoreMissingSlaves)
self.broadcast_enable = kwargs.get('broadcast_enable',
Defaults.broadcast_enable)
self.socket = None
if self._connect():
self.is_running = True
self._build_handler()
def _connect(self):
""" Connect to the serial server
:returns: True if connection succeeded, False otherwise
"""
if self.socket: return True
try:
self.socket = serial.Serial(port=self.device,
timeout=self.timeout,
bytesize=self.bytesize,
stopbits=self.stopbits,
baudrate=self.baudrate,
parity=self.parity)
except serial.SerialException as msg:
_logger.error(msg)
return self.socket is not None
def _build_handler(self):
""" A helper method to create and monkeypatch
a serial handler.
:returns: A patched handler
"""
request = self.socket
request.send = request.write
request.recv = request.read
self.handler = CustomSingleRequestHandler(request,
(self.device, self.device),
self)
def serve_forever(self):
""" Callback for connecting a new client thread
"""
if self._connect():
_logger.debug("Started thread to serve client")
if not self.handler:
self._build_handler()
while self.is_running:
if hasattr(self.handler, "response_manipulator"):
self.handler.response_manipulator()
else:
self.handler.handle()
else:
_logger.error("Error opening serial port , "
"Unable to start server!!")
def server_close(self):
""" Callback for stopping the running server
"""
_logger.debug("Modbus server stopped")
self.is_running = False
self.handler.finish()
self.handler.running = False
self.handler = None
self.socket.close()
# --------------------------------------------------------------------------- #
# Creation Factories
# --------------------------------------------------------------------------- #
def StartTcpServer(context=None, identity=None, address=None,
custom_functions=[], **kwargs):
""" A factory to start and run a tcp modbus server
:param context: The ModbusServerContext datastore
:param identity: An optional identify structure
:param address: An optional (interface, port) to bind to.
:param custom_functions: An optional list of custom function classes
supported by server instance.
:param ignore_missing_slaves: True to not send errors on a request to a
missing slave
"""
framer = kwargs.pop("framer", ModbusSocketFramer)
server = ModbusTcpServer(context, framer, identity, address, **kwargs)
for f in custom_functions:
server.decoder.register(f)
server.serve_forever()
def StartTlsServer(context=None, identity=None, address=None, sslctx=None,
certfile=None, keyfile=None, custom_functions=[], **kwargs):
""" A factory to start and run a tls modbus server
:param context: The ModbusServerContext datastore
:param identity: An optional identify structure
:param address: An optional (interface, port) to bind to.
:param sslctx: The SSLContext to use for TLS (default None and auto create)
:param certfile: The cert file path for TLS (used if sslctx is None)
:param keyfile: The key file path for TLS (used if sslctx is None)
:param custom_functions: An optional list of custom function classes
supported by server instance.
:param ignore_missing_slaves: True to not send errors on a request to a
missing slave
"""
framer = kwargs.pop("framer", ModbusTlsFramer)
server = ModbusTlsServer(context, framer, identity, address, sslctx=sslctx,
certfile=certfile, keyfile=keyfile, **kwargs)
for f in custom_functions:
server.decoder.register(f)
server.serve_forever()
def StartUdpServer(context=None, identity=None, address=None,
custom_functions=[], **kwargs):
""" A factory to start and run a udp modbus server
:param context: The ModbusServerContext datastore
:param identity: An optional identify structure
:param address: An optional (interface, port) to bind to.
:param custom_functions: An optional list of custom function classes
supported by server instance.
:param framer: The framer to operate with (default ModbusSocketFramer)
:param ignore_missing_slaves: True to not send errors on a request
to a missing slave
"""
framer = kwargs.pop('framer', ModbusSocketFramer)
server = ModbusUdpServer(context, framer, identity, address, **kwargs)
for f in custom_functions:
server.decoder.register(f)
server.serve_forever()
def StartSerialServer(context=None, identity=None, custom_functions=[],
**kwargs):
""" A factory to start and run a serial modbus server
:param context: The ModbusServerContext datastore
:param identity: An optional identify structure
:param custom_functions: An optional list of custom function classes
supported by server instance.
:param framer: The framer to operate with (default ModbusAsciiFramer)
:param port: The serial port to attach to
:param stopbits: The number of stop bits to use
:param bytesize: The bytesize of the serial messages
:param parity: Which kind of parity to use
:param baudrate: The baud rate to use for the serial device
:param timeout: The timeout to use for the serial device
:param ignore_missing_slaves: True to not send errors on a request to a
missing slave
"""
framer = kwargs.pop('framer', ModbusAsciiFramer)
server = ModbusSerialServer(context, framer, identity, **kwargs)
for f in custom_functions:
server.decoder.register(f)
server.serve_forever()
# --------------------------------------------------------------------------- #
# Exported symbols
# --------------------------------------------------------------------------- #
__all__ = [
"StartTcpServer", "StartTlsServer", "StartUdpServer", "StartSerialServer"
]