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Pull Request — master (#209)
by
unknown
02:31
created

asyncua.server.uaprocessor.UaProcessor.process()   C

Complexity

Conditions 9

Size

Total Lines 28
Code Lines 27

Duplication

Lines 0
Ratio 0 %

Importance

Changes 0
Metric Value
cc 9
eloc 27
nop 3
dl 0
loc 28
rs 6.6666
c 0
b 0
f 0
1
import time
2
import logging
3
from typing import Deque, Optional
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from collections import deque
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6
from asyncua import ua
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from ..ua.ua_binary import nodeid_from_binary, struct_from_binary, struct_to_binary, uatcp_to_binary
8
from .internal_server import InternalServer, InternalSession
9
from ..common.connection import SecureConnection
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from ..common.utils import ServiceError
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_logger = logging.getLogger(__name__)
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14
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class PublishRequestData:
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    def __init__(self, requesthdr=None, seqhdr=None):
18
        self.requesthdr = requesthdr
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        self.seqhdr = seqhdr
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        self.timestamp = time.time()
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22
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class UaProcessor:
24
    """
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    Processor for OPC UA messages. Implements the OPC UA protocol for the server side.
26
    """
27
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    def __init__(self, internal_server: InternalServer, transport):
29
        self.iserver: InternalServer = internal_server
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        self.name = transport.get_extra_info('peername')
31
        self.sockname = transport.get_extra_info('sockname')
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        self.session: Optional[InternalSession] = None
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        self._transport = transport
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        # deque for Publish Requests
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        self._publish_requests: Deque[PublishRequestData] = deque()
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        # used when we need to wait for PublishRequest
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        self._publish_results: Deque[ua.PublishResult] = deque()
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        self._connection = SecureConnection(ua.SecurityPolicy())
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    def set_policies(self, policies):
41
        self._connection.set_policy_factories(policies)
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    def send_response(self, requesthandle, seqhdr, response, msgtype=ua.MessageType.SecureMessage):
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        response.ResponseHeader.RequestHandle = requesthandle
45
        data = self._connection.message_to_binary(
46
            struct_to_binary(response), message_type=msgtype, request_id=seqhdr.RequestId)
47
        self._transport.write(data)
48
49
    def open_secure_channel(self, algohdr, seqhdr, body):
50
        request = struct_from_binary(ua.OpenSecureChannelRequest, body)
51
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        self._connection.select_policy(
53
            algohdr.SecurityPolicyURI, algohdr.SenderCertificate, request.Parameters.SecurityMode)
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        channel = self._connection.open(request.Parameters, self.iserver)
56
        # send response
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        response = ua.OpenSecureChannelResponse()
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        response.Parameters = channel
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        self.send_response(request.RequestHeader.RequestHandle, seqhdr, response, ua.MessageType.SecureOpen)
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    async def forward_publish_response(self, result: ua.PublishResult):
62
        """
63
        Try to send a `PublishResponse` with the given `PublishResult`.
64
        """
65
        #_logger.info("forward publish response %s", result)
66
        while True:
67
            if not self._publish_requests:
68
                self._publish_results.append(result)
69
                _logger.info(
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                    "Server wants to send publish answer but no publish request is available,"
71
                    "enqueuing notification, length of result queue is %s",
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                    len(self._publish_results)
73
                )
74
                return
75
            # We pop left from the Publish Request deque (FIFO)
76
            requestdata = self._publish_requests.popleft()
77
            if (requestdata.requesthdr.TimeoutHint == 0 or
78
                    requestdata.requesthdr.TimeoutHint != 0 and
79
                    time.time() - requestdata.timestamp < requestdata.requesthdr.TimeoutHint / 1000):
80
                # Continue and use `requestdata` only if there was no timeout
81
                break
82
        response = ua.PublishResponse()
83
        response.Parameters = result
84
        self.send_response(requestdata.requesthdr.RequestHandle, requestdata.seqhdr, response)
85
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    async def process(self, header, body):
87
        try:
88
            msg = self._connection.receive_from_header_and_body(header, body)
89
        except ua.uaerrors.BadUserAccessDenied as e:
90
            _logger.warning("Unauthenticated user attempted to connect")
91
            return False
92
        if isinstance(msg, ua.Message):
93
            if header.MessageType == ua.MessageType.SecureOpen:
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                self.open_secure_channel(msg.SecurityHeader(), msg.SequenceHeader(), msg.body())
95
            elif header.MessageType == ua.MessageType.SecureClose:
96
                self._connection.close()
97
                return False
98
            elif header.MessageType == ua.MessageType.SecureMessage:
99
                return await self.process_message(msg.SequenceHeader(), msg.body())
100
        elif isinstance(msg, ua.Hello):
101
            ack = ua.Acknowledge()
102
            ack.ReceiveBufferSize = msg.ReceiveBufferSize
103
            ack.SendBufferSize = msg.SendBufferSize
104
            data = uatcp_to_binary(ua.MessageType.Acknowledge, ack)
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            self._transport.write(data)
106
        elif isinstance(msg, ua.ErrorMessage):
107
            _logger.warning("Received an error message type")
108
        elif msg is None:
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            pass  # msg is a ChunkType.Intermediate of an ua.MessageType.SecureMessage
110
        else:
111
            _logger.warning("Unsupported message type: %s", header.MessageType)
112
            raise ServiceError(ua.StatusCodes.BadTcpMessageTypeInvalid)
113
        return True
114
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    async def process_message(self, seqhdr, body):
116
        """
117
        Process incoming messages.
118
        """
119
        typeid = nodeid_from_binary(body)
120
        requesthdr = struct_from_binary(ua.RequestHeader, body)
121
        _logger.debug('process_message %r %r', typeid, requesthdr)
122
        try:
123
            return await self._process_message(typeid, requesthdr, seqhdr, body)
124
        except ServiceError as e:
125
            status = ua.StatusCode(e.code)
126
            response = ua.ServiceFault()
127
            response.ResponseHeader.ServiceResult = status
128
            _logger.error("sending service fault response: %s (%s)", status.doc, status.name)
129
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
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            return True
131
        except ua.uaerrors.BadUserAccessDenied as e:
132
            if self.session:
133
                user = self.session.user
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            else:
135
                user = 'Someone'
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            _logger.warning("%s attempted to do something they are not permitted to do", user)
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            response = ua.ServiceFault()
138
            response.ResponseHeader.ServiceResult = ua.StatusCode(ua.StatusCodes.BadUserAccessDenied)
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            self.send_response(requesthdr.RequestHandle, seqhdr, response)
140
        except Exception:
141
            _logger.exception('Error while processing message')
142
            response = ua.ServiceFault()
143
            response.ResponseHeader.ServiceResult = ua.StatusCode(ua.StatusCodes.BadInternalError)
144
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
145
            return True
146
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    async def _process_message(self, typeid, requesthdr, seqhdr, body):
148
        if typeid in [ua.NodeId(ua.ObjectIds.CreateSessionRequest_Encoding_DefaultBinary),
149
                      ua.NodeId(ua.ObjectIds.ActivateSessionRequest_Encoding_DefaultBinary)]:
150
            # The connection is first created without a user being attached, and then during activation the
151
            user = None
152
        else:
153
            user = self.session.user
154
            if self._connection.security_policy.permissions is not None:
155
                if self._connection.security_policy.permissions.check_validity(user, typeid, body) is False:
156
                    raise ua.uaerrors.BadUserAccessDenied
157
158
        if typeid == ua.NodeId(ua.ObjectIds.CreateSessionRequest_Encoding_DefaultBinary):
159
            _logger.info("Create session request (%s)", user)
160
            params = struct_from_binary(ua.CreateSessionParameters, body)
161
            # create the session on server
162
            self.session = self.iserver.create_session(self.name, external=True)
163
            # get a session creation result to send back
164
            sessiondata = await self.session.create_session(params, sockname=self.sockname)
165
            response = ua.CreateSessionResponse()
166
            response.Parameters = sessiondata
167
            response.Parameters.ServerCertificate = self._connection.security_policy.host_certificate
168
            if self._connection.security_policy.peer_certificate is None:
169
                data = params.ClientNonce
170
            else:
171
                data = self._connection.security_policy.peer_certificate + params.ClientNonce
172
            response.Parameters.ServerSignature.Signature = \
173
                self._connection.security_policy.asymmetric_cryptography.signature(data)
174
            response.Parameters.ServerSignature.Algorithm = self._connection.security_policy.AsymmetricSignatureURI
175
            #_logger.info("sending create session response")
176
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
177
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        elif typeid == ua.NodeId(ua.ObjectIds.CloseSessionRequest_Encoding_DefaultBinary):
179
            _logger.info("Close session request (%s)", user)
180
            if self.session:
181
                deletesubs = ua.ua_binary.Primitives.Boolean.unpack(body)
182
                await self.session.close_session(deletesubs)
183
            else:
184
                _logger.info("Request to close non-existing session (%s)", user)
185
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            response = ua.CloseSessionResponse()
187
            _logger.info("sending close session response (%s)", user)
188
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
189
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        elif typeid == ua.NodeId(ua.ObjectIds.ActivateSessionRequest_Encoding_DefaultBinary):
191
            _logger.info("Activate session request (%s)", user)
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            params = struct_from_binary(ua.ActivateSessionParameters, body)
193
            if not self.session:
194
                _logger.info("request to activate non-existing session (%s)", user)
195
                raise ServiceError(ua.StatusCodes.BadSessionIdInvalid)
196
            if self._connection.security_policy.host_certificate is None:
197
                data = self.session.nonce
198
            else:
199
                data = self._connection.security_policy.host_certificate + self.session.nonce
200
            self._connection.security_policy.asymmetric_cryptography.verify(data, params.ClientSignature.Signature)
201
            result = self.session.activate_session(params, self._connection.security_policy.peer_certificate)
202
            response = ua.ActivateSessionResponse()
203
            response.Parameters = result
204
            #_logger.info("sending read response")
205
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
206
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        elif typeid == ua.NodeId(ua.ObjectIds.ReadRequest_Encoding_DefaultBinary):
208
            _logger.info("Read request (%s)", user)
209
            params = struct_from_binary(ua.ReadParameters, body)
210
            results = await self.session.read(params)
211
            response = ua.ReadResponse()
212
            response.Results = results
213
            #_logger.info("sending read response")
214
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
215
216
        elif typeid == ua.NodeId(ua.ObjectIds.WriteRequest_Encoding_DefaultBinary):
217
            _logger.info("Write request (%s)", user)
218
            params = struct_from_binary(ua.WriteParameters, body)
219
            results = await self.session.write(params)
220
            response = ua.WriteResponse()
221
            response.Results = results
222
            #_logger.info("sending write response")
223
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
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225
        elif typeid == ua.NodeId(ua.ObjectIds.BrowseRequest_Encoding_DefaultBinary):
226
            _logger.info("Browse request (%s)", user)
227
            params = struct_from_binary(ua.BrowseParameters, body)
228
            results = await self.session.browse(params)
229
            response = ua.BrowseResponse()
230
            response.Results = results
231
            #_logger.info("sending browse response")
232
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
233
234
        elif typeid == ua.NodeId(ua.ObjectIds.GetEndpointsRequest_Encoding_DefaultBinary):
235
            _logger.info("get endpoints request (%s)", user)
236
            params = struct_from_binary(ua.GetEndpointsParameters, body)
237
            endpoints = await self.iserver.get_endpoints(params, sockname=self.sockname)
238
            response = ua.GetEndpointsResponse()
239
            response.Endpoints = endpoints
240
            #_logger.info("sending get endpoints response")
241
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
242
243
        elif typeid == ua.NodeId(ua.ObjectIds.FindServersRequest_Encoding_DefaultBinary):
244
            _logger.info("find servers request (%s)", user)
245
            params = struct_from_binary(ua.FindServersParameters, body)
246
            servers = self.iserver.find_servers(params)
247
            response = ua.FindServersResponse()
248
            response.Servers = servers
249
            #_logger.info("sending find servers response")
250
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
251
252
        elif typeid == ua.NodeId(ua.ObjectIds.RegisterServerRequest_Encoding_DefaultBinary):
253
            _logger.info("register server request %s", user)
254
            serv = struct_from_binary(ua.RegisteredServer, body)
255
            self.iserver.register_server(serv)
256
            response = ua.RegisterServerResponse()
257
            #_logger.info("sending register server response")
258
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
259
260
        elif typeid == ua.NodeId(ua.ObjectIds.RegisterServer2Request_Encoding_DefaultBinary):
261
            _logger.info("register server 2 request %s", user)
262
            params = struct_from_binary(ua.RegisterServer2Parameters, body)
263
            results = self.iserver.register_server2(params)
264
            response = ua.RegisterServer2Response()
265
            response.ConfigurationResults = results
266
            #_logger.info("sending register server 2 response")
267
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
268
269
        elif typeid == ua.NodeId(ua.ObjectIds.TranslateBrowsePathsToNodeIdsRequest_Encoding_DefaultBinary):
270
            _logger.info("translate browsepaths to nodeids request (%s)", user)
271
            params = struct_from_binary(ua.TranslateBrowsePathsToNodeIdsParameters, body)
272
            paths = await self.session.translate_browsepaths_to_nodeids(params.BrowsePaths)
273
            response = ua.TranslateBrowsePathsToNodeIdsResponse()
274
            response.Results = paths
275
            #_logger.info("sending translate browsepaths to nodeids response")
276
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
277
278
        elif typeid == ua.NodeId(ua.ObjectIds.AddNodesRequest_Encoding_DefaultBinary):
279
            _logger.info("add nodes request (%s)", user)
280
            params = struct_from_binary(ua.AddNodesParameters, body)
281
            results = await self.session.add_nodes(params.NodesToAdd)
282
            response = ua.AddNodesResponse()
283
            response.Results = results
284
            #_logger.info("sending add node response")
285
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
286
287
        elif typeid == ua.NodeId(ua.ObjectIds.DeleteNodesRequest_Encoding_DefaultBinary):
288
            _logger.info("delete nodes request (%s)", user)
289
            params = struct_from_binary(ua.DeleteNodesParameters, body)
290
            results = await self.session.delete_nodes(params)
291
            response = ua.DeleteNodesResponse()
292
            response.Results = results
293
            #_logger.info("sending delete node response")
294
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
295
296
        elif typeid == ua.NodeId(ua.ObjectIds.AddReferencesRequest_Encoding_DefaultBinary):
297
            _logger.info("add references request (%s)", user)
298
            params = struct_from_binary(ua.AddReferencesParameters, body)
299
            results = await self.session.add_references(params.ReferencesToAdd)
300
            response = ua.AddReferencesResponse()
301
            response.Results = results
302
            #_logger.info("sending add references response")
303
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
304
305
        elif typeid == ua.NodeId(ua.ObjectIds.DeleteReferencesRequest_Encoding_DefaultBinary):
306
            _logger.info("delete references request (%s)", user)
307
            params = struct_from_binary(ua.DeleteReferencesParameters, body)
308
            results = await self.session.delete_references(params.ReferencesToDelete)
309
            response = ua.DeleteReferencesResponse()
310
            response.Parameters.Results = results
311
            #_logger.info("sending delete references response")
312
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
313
314
        elif typeid == ua.NodeId(ua.ObjectIds.CreateSubscriptionRequest_Encoding_DefaultBinary):
315
            _logger.info("create subscription request (%s)", user)
316
            params = struct_from_binary(ua.CreateSubscriptionParameters, body)
317
            result = await self.session.create_subscription(params, callback=self.forward_publish_response)
318
            response = ua.CreateSubscriptionResponse()
319
            response.Parameters = result
320
            #_logger.info("sending create subscription response")
321
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
322
323
        elif typeid == ua.NodeId(ua.ObjectIds.DeleteSubscriptionsRequest_Encoding_DefaultBinary):
324
            _logger.info("delete subscriptions request (%s)", user)
325
            params = struct_from_binary(ua.DeleteSubscriptionsParameters, body)
326
            results = await self.session.delete_subscriptions(params.SubscriptionIds)
327
            response = ua.DeleteSubscriptionsResponse()
328
            response.Results = results
329
            #_logger.info("sending delete subscription response")
330
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
331
332
        elif typeid == ua.NodeId(ua.ObjectIds.CreateMonitoredItemsRequest_Encoding_DefaultBinary):
333
            _logger.info("create monitored items request (%s)", user)
334
            params = struct_from_binary(ua.CreateMonitoredItemsParameters, body)
335
            results = await self.session.create_monitored_items(params)
336
            response = ua.CreateMonitoredItemsResponse()
337
            response.Results = results
338
            #_logger.info("sending create monitored items response")
339
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
340
341
        elif typeid == ua.NodeId(ua.ObjectIds.ModifyMonitoredItemsRequest_Encoding_DefaultBinary):
342
            _logger.info("modify monitored items request (%s)", user)
343
            params = struct_from_binary(ua.ModifyMonitoredItemsParameters, body)
344
            results = await self.session.modify_monitored_items(params)
345
            response = ua.ModifyMonitoredItemsResponse()
346
            response.Results = results
347
            #_logger.info("sending modify monitored items response")
348
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
349
350
        elif typeid == ua.NodeId(ua.ObjectIds.DeleteMonitoredItemsRequest_Encoding_DefaultBinary):
351
            _logger.info("delete monitored items request (%s)", user)
352
            params = struct_from_binary(ua.DeleteMonitoredItemsParameters, body)
353
            results = await self.session.delete_monitored_items(params)
354
            response = ua.DeleteMonitoredItemsResponse()
355
            response.Results = results
356
            #_logger.info("sending delete monitored items response")
357
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
358
359
        elif typeid == ua.NodeId(ua.ObjectIds.HistoryReadRequest_Encoding_DefaultBinary):
360
            _logger.info("history read request (%s)", user)
361
            params = struct_from_binary(ua.HistoryReadParameters, body)
362
            results = await self.session.history_read(params)
363
            response = ua.HistoryReadResponse()
364
            response.Results = results
365
            #_logger.info("sending history read response")
366
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
367
368
        elif typeid == ua.NodeId(ua.ObjectIds.RegisterNodesRequest_Encoding_DefaultBinary):
369
            _logger.info("register nodes request (%s)", user)
370
            params = struct_from_binary(ua.RegisterNodesParameters, body)
371
            _logger.info("Node registration not implemented")
372
            response = ua.RegisterNodesResponse()
373
            response.Parameters.RegisteredNodeIds = params.NodesToRegister
374
            #_logger.info("sending register nodes response")
375
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
376
377
        elif typeid == ua.NodeId(ua.ObjectIds.UnregisterNodesRequest_Encoding_DefaultBinary):
378
            _logger.info("unregister nodes request (%s)", user)
379
            params = struct_from_binary(ua.UnregisterNodesParameters, body)
380
            response = ua.UnregisterNodesResponse()
381
            #_logger.info("sending unregister nodes response")
382
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
383
384
        elif typeid == ua.NodeId(ua.ObjectIds.PublishRequest_Encoding_DefaultBinary):
385
            _logger.debug("publish request (%s)", user)
386
            if not self.session:
387
                return False
388
            params = struct_from_binary(ua.PublishParameters, body)
389
            data = PublishRequestData(requesthdr=requesthdr, seqhdr=seqhdr)
390
            # Store the Publish Request (will be used to send publish answers from server)
391
            self._publish_requests.append(data)
392
            # If there is an enqueued result forward it immediately
393
            while self._publish_results:
394
                result = self._publish_results.popleft()
395
                if result.SubscriptionId not in self.session.subscription_service.active_subscription_ids:
396
                    # Discard the result if the subscription is no longer active
397
                    continue
398
                await self.forward_publish_response(result)
399
                break
400
            self.session.publish(params.SubscriptionAcknowledgements)
401
            #_logger.debug("publish forward to server")
402
403
        elif typeid == ua.NodeId(ua.ObjectIds.RepublishRequest_Encoding_DefaultBinary):
404
            _logger.info("re-publish request (%s)", user)
405
            params = struct_from_binary(ua.RepublishParameters, body)
406
            msg = self.session.republish(params)
407
            response = ua.RepublishResponse()
408
            response.NotificationMessage = msg
409
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
410
411
        elif typeid == ua.NodeId(ua.ObjectIds.CloseSecureChannelRequest_Encoding_DefaultBinary):
412
            _logger.info("close secure channel request (%s)", user)
413
            self._connection.close()
414
            response = ua.CloseSecureChannelResponse()
415
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
416
            return False
417
418
        elif typeid == ua.NodeId(ua.ObjectIds.CallRequest_Encoding_DefaultBinary):
419
            _logger.info("call request (%s)", user)
420
            params = struct_from_binary(ua.CallParameters, body)
421
            results = await self.session.call(params.MethodsToCall)
422
            response = ua.CallResponse()
423
            response.Results = results
424
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
425
426
        elif typeid == ua.NodeId(ua.ObjectIds.SetMonitoringModeRequest_Encoding_DefaultBinary):
427
            _logger.info("set monitoring mode request (%s)", user)
428
            params = struct_from_binary(ua.SetMonitoringModeParameters, body)
429
            # FIXME: Implement SetMonitoringMode
430
            # For now send dummy results to keep clients happy
431
            response = ua.SetMonitoringModeResponse()
432
            results = ua.SetMonitoringModeResult()
433
            ids = params.MonitoredItemIds
434
            statuses = [ua.StatusCode(ua.StatusCodes.Good) for node_id in ids]
435
            results.Results = statuses
436
            response.Parameters = results
437
            _logger.info("sending set monitoring mode response")
438
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
439
440
        elif typeid == ua.NodeId(ua.ObjectIds.SetPublishingModeRequest_Encoding_DefaultBinary):
441
            _logger.info("set publishing mode request (%s)", user)
442
            params = struct_from_binary(ua.SetPublishingModeParameters, body)
443
            # FIXME: Implement SetPublishingMode
444
            # For now send dummy results to keep clients happy
445
            response = ua.SetPublishingModeResponse()
446
            results = ua.SetPublishingModeResult()
447
            ids = params.SubscriptionIds
448
            statuses = [ua.StatusCode(ua.StatusCodes.Good) for node_id in ids]
449
            results.Results = statuses
450
            response.Parameters = results
451
            _logger.info("sending set publishing mode response")
452
            self.send_response(requesthdr.RequestHandle, seqhdr, response)
453
454
        else:
455
            _logger.warning("Unknown message received %s (%s)", typeid, user)
456
            raise ServiceError(ua.StatusCodes.BadServiceUnsupported)
457
458
        return True
459
460
    async def close(self):
461
        """
462
        to be called when client has disconnected to ensure we really close
463
        everything we should
464
        """
465
        _logger.info("Cleanup client connection: %s", self.name)
466
        if self.session:
467
            await self.session.close_session(True)
468