A-ABORT
상속: PDU
예제 #1
0
        private bool ProcessNextPDU()
        {
            RawPDU raw = new RawPDU(_network);

            if (raw.Type == 0x04) {
                if (_dimse == null) {
                    _dimse = new DcmDimseInfo();
                }
            }

            try {
                raw.ReadPDU();

                switch (raw.Type) {
                case 0x01: {
                        _assoc = new DcmAssociate();
                        AAssociateRQ pdu = new AAssociateRQ(_assoc);
                        pdu.Read(raw);
                        Log.Info("{0} <- Association request:\n{1}", LogID, Associate.ToString());
                        OnReceiveAssociateRequest(_assoc);
                        return true;
                    }
                case 0x02: {
                        AAssociateAC pdu = new AAssociateAC(_assoc);
                        pdu.Read(raw);
                        Log.Info("{0} <- Association accept:\n{1}", LogID, Associate.ToString());
                        OnReceiveAssociateAccept(_assoc);
                        return true;
                    }
                case 0x03: {
                        AAssociateRJ pdu = new AAssociateRJ();
                        pdu.Read(raw);
                        Log.Info("{0} <- Association reject [result: {1}; source: {2}; reason: {3}]", LogID, pdu.Result, pdu.Source, pdu.Reason);
                        OnReceiveAssociateReject(pdu.Result, pdu.Source, pdu.Reason);
                        return true;
                    }
                case 0x04: {
                        PDataTF pdu = new PDataTF();
                        pdu.Read(raw);
                        //Log.Debug("{0} <- P-Data-TF", LogID);
                        return ProcessPDataTF(pdu);
                    }
                case 0x05: {
                        AReleaseRQ pdu = new AReleaseRQ();
                        pdu.Read(raw);
                        Log.Info("{0} <- Association release request", LogID);
                        OnReceiveReleaseRequest();
                        return true;
                    }
                case 0x06: {
                        AReleaseRP pdu = new AReleaseRP();
                        pdu.Read(raw);
                        Log.Info("{0} <- Association release response", LogID);
                        OnReceiveReleaseResponse();
                        return true;
                    }
                case 0x07: {
                        AAbort pdu = new AAbort();
                        pdu.Read(raw);
                        Log.Info("{0} <- Association abort: {1} - {2}", LogID, pdu.Source, pdu.Reason);
                        OnReceiveAbort(pdu.Source, pdu.Reason);
                        return true;
                    }
                case 0xFF: {
                        return false;
                    }
                default:
                    throw new DicomNetworkException("Unknown PDU type");
                }
            } catch (SocketException) {
                throw;
            } catch (Exception e) {
            #if DEBUG
                Log.Error("{0} -> Error reading PDU [type: 0x{1:x2}]: {2}", LogID, raw.Type, e.ToString());
            #else
                Log.Error("{0} -> Error reading PDU [type: 0x{1:x2}]: {2}", LogID, raw.Type, e.Message);
            #endif
                OnNetworkError(e);
                //String file = String.Format(@"{0}\Errors\{1}.pdu",
                //    Dicom.Debug.GetStartDirectory(), DateTime.Now.Ticks);
                //Directory.CreateDirectory(Dicom.Debug.GetStartDirectory() + @"\Errors");
                //raw.Save(file);
                return false;
            }
        }
예제 #2
0
 /// <summary>
 /// The ACSE A-ABORT service shall be used by a requestor in either of the AEs 
 /// to cause the abnormal release of the association. It shall be a non-confirmed 
 /// service. However, because of the possibility of an A-ABORT service procedure 
 /// collision, the delivery of the indication primitive is not guaranteed. Should
 /// such a collision occur, both AEs are aware that the association has been 
 /// terminated. The abort shall be performed through A-ABORT request and A-ABORT 
 /// indication primitives.
 /// </summary>
 /// <param name="source"></param>
 /// <param name="reason"></param>
 protected void SendAbort(DcmAbortSource source, DcmAbortReason reason)
 {
     Log.Info("{0} -> Abort [source: {1}; reason: {2}]", LogID, source, reason);
     AAbort pdu = new AAbort(source, reason);
     SendRawPDU(pdu.Write());
 }
예제 #3
0
        private async void ReadAndProcessPDUs()
        {
            try
            {
                while (this.IsConnected)
                {
                    // Read PDU header
                    _readLength = 6;

                    var buffer = new byte[6];
                    var count = await this._network.ReadAsync(buffer, 0, 6).ConfigureAwait(false);

                    do
                    {
                        if (count == 0)
                        {
                            // disconnected
                            this.CloseConnection(null);
                            return;
                        }

                        this._readLength -= count;
                        if (this._readLength > 0)
                        {
                            count =
                                await
                                this._network.ReadAsync(buffer, 6 - this._readLength, this._readLength)
                                    .ConfigureAwait(false);
                        }
                    }
                    while (this._readLength > 0);

                    var length = BitConverter.ToInt32(buffer, 2);
                    length = Endian.Swap(length);

                    this._readLength = length;

                    Array.Resize(ref buffer, length + 6);

                    count = await this._network.ReadAsync(buffer, 6, length).ConfigureAwait(false);

                    // Read PDU
                    do
                    {
                        if (count == 0)
                        {
                            // disconnected
                            this.CloseConnection(null);
                            return;
                        }

                        this._readLength -= count;
                        if (this._readLength > 0)
                        {
                            count =
                                await
                                this._network.ReadAsync(buffer, buffer.Length - this._readLength, this._readLength)
                                    .ConfigureAwait(false);
                        }
                    }
                    while (this._readLength > 0);

                    var raw = new RawPDU(buffer);

                    switch (raw.Type)
                    {
                        case 0x01:
                            {
                                Association = new DicomAssociation();
                                var pdu = new AAssociateRQ(Association);
                                pdu.Read(raw);
                                LogID = Association.CallingAE;
                                if (Options.UseRemoteAEForLogName) Logger = LogManager.GetLogger(LogID);
                                Logger.Info(
                                    "{callingAE} <- Association request:\n{association}",
                                    LogID,
                                    Association.ToString());
                                if (this is IDicomServiceProvider) (this as IDicomServiceProvider).OnReceiveAssociationRequest(Association);
                                break;
                            }
                        case 0x02:
                            {
                                var pdu = new AAssociateAC(Association);
                                pdu.Read(raw);
                                LogID = Association.CalledAE;
                                Logger.Info(
                                    "{calledAE} <- Association accept:\n{assocation}",
                                    LogID,
                                    Association.ToString());
                                if (this is IDicomServiceUser) (this as IDicomServiceUser).OnReceiveAssociationAccept(Association);
                                break;
                            }
                        case 0x03:
                            {
                                var pdu = new AAssociateRJ();
                                pdu.Read(raw);
                                Logger.Info(
                                    "{logId} <- Association reject [result: {pduResult}; source: {pduSource}; reason: {pduReason}]",
                                    LogID,
                                    pdu.Result,
                                    pdu.Source,
                                    pdu.Reason);
                                if (this is IDicomServiceUser)
                                    (this as IDicomServiceUser).OnReceiveAssociationReject(
                                        pdu.Result,
                                        pdu.Source,
                                        pdu.Reason);
                                break;
                            }
                        case 0x04:
                            {
                                var pdu = new PDataTF();
                                pdu.Read(raw);
                                if (Options.LogDataPDUs) Logger.Info("{logId} <- {@pdu}", LogID, pdu);
                                await this.ProcessPDataTFAsync(pdu).ConfigureAwait(false);
                                break;
                            }
                        case 0x05:
                            {
                                var pdu = new AReleaseRQ();
                                pdu.Read(raw);
                                Logger.Info("{logId} <- Association release request", LogID);
                                if (this is IDicomServiceProvider) (this as IDicomServiceProvider).OnReceiveAssociationReleaseRequest();
                                break;
                            }
                        case 0x06:
                            {
                                var pdu = new AReleaseRP();
                                pdu.Read(raw);
                                Logger.Info("{logId} <- Association release response", LogID);
                                if (this is IDicomServiceUser) (this as IDicomServiceUser).OnReceiveAssociationReleaseResponse();
                                CloseConnection(null);
                                return;
                            }
                        case 0x07:
                            {
                                var pdu = new AAbort();
                                pdu.Read(raw);
                                Logger.Info(
                                    "{logId} <- Abort: {pduSource} - {pduReason}",
                                    LogID,
                                    pdu.Source,
                                    pdu.Reason);
                                if (this is IDicomServiceProvider) (this as IDicomServiceProvider).OnReceiveAbort(pdu.Source, pdu.Reason);
                                else if (this is IDicomServiceUser) (this as IDicomServiceUser).OnReceiveAbort(pdu.Source, pdu.Reason);
                                CloseConnection(null);
                                return;
                            }
                        case 0xFF:
                            {
                                break;
                            }
                        default:
                            throw new DicomNetworkException("Unknown PDU type");
                    }
                }
            }
            catch (ObjectDisposedException)
            {
                // silently ignore
                CloseConnection(null);
            }
            catch (NullReferenceException)
            {
                // connection already closed; silently ignore
                CloseConnection(null);
            }
            catch (IOException e)
            {
                LogIOException(this.Logger, e, true);
                CloseConnection(e);
            }
            catch (Exception e)
            {
                Logger.Error("Exception processing PDU: {@error}", e);
                CloseConnection(e);
            }
        }
예제 #4
0
        private void EndReadPDU(IAsyncResult result)
        {
            try {
                byte[] buffer = (byte[])result.AsyncState;

                int count = _network.EndRead(result);
                if (count == 0)
                {
                    // disconnected
                    CloseConnection(0);
                    return;
                }

                _readLength -= count;

                if (_readLength > 0)
                {
                    _network.BeginRead(buffer, buffer.Length - _readLength, _readLength, EndReadPDU, buffer);
                    return;
                }

                var raw = new RawPDU(buffer);

                switch (raw.Type)
                {
                case 0x01: {
                    Association = new DicomAssociation();
                    var pdu = new AAssociateRQ(Association);
                    pdu.Read(raw);
                    LogID = Association.CallingAE;
                    if (Options.UseRemoteAEForLogName)
                    {
                        Logger = LogManager.Default.GetLogger(LogID);
                    }
                    Logger.Info("{0} <- Association request:\n{1}", LogID, Association.ToString());
                    if (this is IDicomServiceProvider)
                    {
                        (this as IDicomServiceProvider).OnReceiveAssociationRequest(Association);
                    }
                    break;
                }

                case 0x02: {
                    var pdu = new AAssociateAC(Association);
                    pdu.Read(raw);
                    LogID = Association.CalledAE;
                    Logger.Info("{0} <- Association accept:\n{1}", LogID, Association.ToString());
                    if (this is IDicomServiceUser)
                    {
                        (this as IDicomServiceUser).OnReceiveAssociationAccept(Association);
                    }
                    break;
                }

                case 0x03: {
                    var pdu = new AAssociateRJ();
                    pdu.Read(raw);
                    Logger.Info("{0} <- Association reject [result: {1}; source: {2}; reason: {3}]", LogID, pdu.Result, pdu.Source, pdu.Reason);
                    if (this is IDicomServiceUser)
                    {
                        (this as IDicomServiceUser).OnReceiveAssociationReject(pdu.Result, pdu.Source, pdu.Reason);
                    }
                    break;
                }

                case 0x04: {
                    var pdu = new PDataTF();
                    pdu.Read(raw);
                    if (Options.LogDataPDUs)
                    {
                        Logger.Info("{0} <- {1}", LogID, pdu);
                    }
                    _processQueue.Queue(ProcessPDataTF, pdu);
                    break;
                }

                case 0x05: {
                    var pdu = new AReleaseRQ();
                    pdu.Read(raw);
                    Logger.Info("{0} <- Association release request", LogID);
                    if (this is IDicomServiceProvider)
                    {
                        (this as IDicomServiceProvider).OnReceiveAssociationReleaseRequest();
                    }
                    break;
                }

                case 0x06: {
                    var pdu = new AReleaseRP();
                    pdu.Read(raw);
                    Logger.Info("{0} <- Association release response", LogID);
                    if (this is IDicomServiceUser)
                    {
                        (this as IDicomServiceUser).OnReceiveAssociationReleaseResponse();
                    }
                    CloseConnection(0);
                    break;
                }

                case 0x07: {
                    var pdu = new AAbort();
                    pdu.Read(raw);
                    Logger.Info("{0} <- Abort: {1} - {2}", LogID, pdu.Source, pdu.Reason);
                    if (this is IDicomServiceProvider)
                    {
                        (this as IDicomServiceProvider).OnReceiveAbort(pdu.Source, pdu.Reason);
                    }
                    else if (this is IDicomServiceUser)
                    {
                        (this as IDicomServiceUser).OnReceiveAbort(pdu.Source, pdu.Reason);
                    }
                    CloseConnection(0);
                    break;
                }

                case 0xFF: {
                    break;
                }

                default:
                    throw new DicomNetworkException("Unknown PDU type");
                }

                BeginReadPDUHeader();
            } catch (IOException e) {
                int error = 0;
                if (e.InnerException is SocketException)
                {
                    error = (e.InnerException as SocketException).ErrorCode;
                    Logger.Error("Socket error while reading PDU: {0} [{1}]", (e.InnerException as SocketException).SocketErrorCode, (e.InnerException as SocketException).ErrorCode);
                }
                else if (!(e.InnerException is ObjectDisposedException))
                {
                    Logger.Error("IO exception while reading PDU: {0}", e.ToString());
                }

                CloseConnection(error);
            } catch (NullReferenceException) {
                // connection already closed; silently ignore
                CloseConnection(0);
            } catch (Exception e) {
                Logger.Error("Exception processing PDU: {0}", e.ToString());
                CloseConnection(0);
            }
        }
예제 #5
0
        private void EndReadPDU(IAsyncResult result)
        {
            try {
                byte[] buffer = (byte[])result.AsyncState;

                int count = _network.EndRead(result);
                if (count == 0)
                {
                    // disconnected
                    _network.Close();
                    _isConnected = false;
                    return;
                }

                _readLength -= count;

                if (_readLength > 0)
                {
                    _network.BeginRead(buffer, buffer.Length - _readLength, _readLength, EndReadPDU, buffer);
                    return;
                }

                var raw = new RawPDU(buffer);

                switch (raw.Type)
                {
                case 0x01: {
                    Association = new DicomAssociation();
                    var pdu = new AAssociateRQ(Association);
                    pdu.Read(raw);
                    LogID = Association.CallingAE;
                    Logger.Log(LogLevel.Info, "{0} <- Association request:\n{1}", LogID, Association.ToString());
                    if (this is IDicomServiceProvider)
                    {
                        (this as IDicomServiceProvider).OnReceiveAssociationRequest(Association);
                    }
                    break;
                }

                case 0x02: {
                    var pdu = new AAssociateAC(Association);
                    pdu.Read(raw);
                    LogID = Association.CalledAE;
                    Logger.Log(LogLevel.Info, "{0} <- Association accept:\n{1}", LogID, Association.ToString());
                    if (this is IDicomServiceUser)
                    {
                        (this as IDicomServiceUser).OnReceiveAssociationAccept(Association);
                    }
                    break;
                }

                case 0x03: {
                    var pdu = new AAssociateRJ();
                    pdu.Read(raw);
                    Logger.Log(LogLevel.Info, "{0} <- Association reject [result: {1}; source: {2}; reason: {3}]", LogID, pdu.Result, pdu.Source, pdu.Reason);
                    if (this is IDicomServiceUser)
                    {
                        (this as IDicomServiceUser).OnReceiveAssociationReject(pdu.Result, pdu.Source, pdu.Reason);
                    }
                    break;
                }

                case 0x04: {
                    var pdu = new PDataTF();
                    pdu.Read(raw);
                    ProcessPDataTF(pdu);
                    break;
                }

                case 0x05: {
                    var pdu = new AReleaseRQ();
                    pdu.Read(raw);
                    Logger.Log(LogLevel.Info, "{0} <- Association release request", LogID);
                    if (this is IDicomServiceProvider)
                    {
                        (this as IDicomServiceProvider).OnReceiveAssociationReleaseRequest();
                    }
                    break;
                }

                case 0x06: {
                    var pdu = new AReleaseRP();
                    pdu.Read(raw);
                    Logger.Log(LogLevel.Info, "{0} <- Association release response", LogID);
                    if (this is IDicomServiceUser)
                    {
                        (this as IDicomServiceUser).OnReceiveAssociationReleaseResponse();
                    }
                    _network.Close();
                    _isConnected = false;
                    break;
                }

                case 0x07: {
                    var pdu = new AAbort();
                    pdu.Read(raw);
                    Logger.Log(LogLevel.Info, "{0} <- Abort: {1} - {2}", LogID, pdu.Source, pdu.Reason);
                    if (this is IDicomServiceProvider)
                    {
                        (this as IDicomServiceProvider).OnReceiveAbort(pdu.Source, pdu.Reason);
                    }
                    else if (this is IDicomServiceUser)
                    {
                        (this as IDicomServiceUser).OnReceiveAbort(pdu.Source, pdu.Reason);
                    }
                    _network.Close();
                    _isConnected = false;
                    break;
                }

                case 0xFF: {
                    break;
                }

                default:
                    throw new DicomNetworkException("Unknown PDU type");
                }

                BeginReadPDUHeader();
            } catch (Exception e) {
                Logger.Log(LogLevel.Error, "Exception processing PDU: {0}", e.ToString());
                _network.Close();
                _isConnected = false;
            }
        }
예제 #6
0
		private void EndReadPDU(IAsyncResult result) {
			try {
				byte[] buffer = (byte[])result.AsyncState;

				int count = _network.EndRead(result);
				if (count == 0) {
					// disconnected
					CloseConnection(null);
					return;
				}

				_readLength -= count;

				if (_readLength > 0) {
					_network.BeginRead(buffer, buffer.Length - _readLength, _readLength, EndReadPDU, buffer);
					return;
				}

				var raw = new RawPDU(buffer);

				switch (raw.Type) {
				case 0x01: {
						Association = new DicomAssociation();
						var pdu = new AAssociateRQ(Association);
						pdu.Read(raw);
						LogID = Association.CallingAE;
						if (Options.UseRemoteAEForLogName)
							Logger = LogManager.Default.GetLogger(LogID);
						Logger.Info("{callingAE} <- Association request:\n{association}", LogID, Association.ToString());
						if (this is IDicomServiceProvider)
							(this as IDicomServiceProvider).OnReceiveAssociationRequest(Association);
						break;
					}
				case 0x02: {
						var pdu = new AAssociateAC(Association);
						pdu.Read(raw);
						LogID = Association.CalledAE;
						Logger.Info("{calledAE} <- Association accept:\n{assocation}", LogID, Association.ToString());
						if (this is IDicomServiceUser)
							(this as IDicomServiceUser).OnReceiveAssociationAccept(Association);
						break;
					}
				case 0x03: {
						var pdu = new AAssociateRJ();
						pdu.Read(raw);
						Logger.Info("{logId} <- Association reject [result: {pduResult}; source: {pduSource}; reason: {pduReason}]", LogID, pdu.Result, pdu.Source, pdu.Reason);
						if (this is IDicomServiceUser)
							(this as IDicomServiceUser).OnReceiveAssociationReject(pdu.Result, pdu.Source, pdu.Reason);
						break;
					}
				case 0x04: {
						var pdu = new PDataTF();
						pdu.Read(raw);
						if (Options.LogDataPDUs)
							Logger.Info("{logId} <- {@pdu}", LogID, pdu);
						_processQueue.Queue(ProcessPDataTF, pdu);
						break;
					}
				case 0x05: {
						var pdu = new AReleaseRQ();
						pdu.Read(raw);
						Logger.Info("{logId} <- Association release request", LogID);
						if (this is IDicomServiceProvider)
							(this as IDicomServiceProvider).OnReceiveAssociationReleaseRequest();
						break;
					}
				case 0x06: {
						var pdu = new AReleaseRP();
						pdu.Read(raw);
						Logger.Info("{logId} <- Association release response", LogID);
						if (this is IDicomServiceUser)
							(this as IDicomServiceUser).OnReceiveAssociationReleaseResponse();
						CloseConnection(null);
						break;
					}
				case 0x07: {
						var pdu = new AAbort();
						pdu.Read(raw);
						Logger.Info("{logId} <- Abort: {pduSource} - {pduReason}", LogID, pdu.Source, pdu.Reason);
						if (this is IDicomServiceProvider)
							(this as IDicomServiceProvider).OnReceiveAbort(pdu.Source, pdu.Reason);
						else if (this is IDicomServiceUser)
							(this as IDicomServiceUser).OnReceiveAbort(pdu.Source, pdu.Reason);
						CloseConnection(null);
						break;
					}
				case 0xFF: {
						break;
					}
				default:
					throw new DicomNetworkException("Unknown PDU type");
				}

				BeginReadPDUHeader();
			} catch (IOException e) {
				if (e.InnerException is SocketException) {
					Logger.Error("Socket error while reading PDU: {socketErrorCode} [{errorCode}]", (e.InnerException as SocketException).SocketErrorCode, (e.InnerException as SocketException).ErrorCode);
				} else if (!(e.InnerException is ObjectDisposedException))
					Logger.Error("IO exception while reading PDU: {@error}", e);

				CloseConnection(e);
			} catch (NullReferenceException) {
				// connection already closed; silently ignore
				CloseConnection(null);
			} catch (Exception e) {
				Logger.Error("Exception processing PDU: {@error}", e);
				CloseConnection(e);
			}
		}
예제 #7
0
        private void EndReadPDU(IAsyncResult result)
        {
            try {
                byte[] buffer = (byte[])result.AsyncState;

                int count = _network.EndRead(result);
                if (count == 0) {
                    // disconnected
                    CloseConnection(0);
                    return;
                }

                _readLength -= count;

                if (_readLength > 0) {
                    _network.BeginRead(buffer, buffer.Length - _readLength, _readLength, EndReadPDU, buffer);
                    return;
                }

                var raw = new RawPDU(buffer);

                switch (raw.Type) {
                case 0x01: {
                        Association = new DicomAssociation();
                        var pdu = new AAssociateRQ(Association);
                        pdu.Read(raw);
                        LogID = Association.CallingAE;
                        Logger.Log(LogLevel.Info, "{0} <- Association request:\n{1}", LogID, Association.ToString());
                        if (this is IDicomServiceProvider)
                            (this as IDicomServiceProvider).OnReceiveAssociationRequest(Association);
                        break;
                    }
                case 0x02: {
                        var pdu = new AAssociateAC(Association);
                        pdu.Read(raw);
                        LogID = Association.CalledAE;
                        Logger.Log(LogLevel.Info, "{0} <- Association accept:\n{1}", LogID, Association.ToString());
                        if (this is IDicomServiceUser)
                            (this as IDicomServiceUser).OnReceiveAssociationAccept(Association);
                        break;
                    }
                case 0x03: {
                        var pdu = new AAssociateRJ();
                        pdu.Read(raw);
                        Logger.Log(LogLevel.Info, "{0} <- Association reject [result: {1}; source: {2}; reason: {3}]", LogID, pdu.Result, pdu.Source, pdu.Reason);
                        if (this is IDicomServiceUser)
                            (this as IDicomServiceUser).OnReceiveAssociationReject(pdu.Result, pdu.Source, pdu.Reason);
                        break;
                    }
                case 0x04: {
                        var pdu = new PDataTF();
                        pdu.Read(raw);
                        if (Options.LogDataPDUs)
                            Logger.Info("{0} <- {1}", LogID, pdu);
                        _processQueue.Queue(ProcessPDataTF, pdu);
                        break;
                    }
                case 0x05: {
                        var pdu = new AReleaseRQ();
                        pdu.Read(raw);
                        Logger.Log(LogLevel.Info, "{0} <- Association release request", LogID);
                        if (this is IDicomServiceProvider)
                            (this as IDicomServiceProvider).OnReceiveAssociationReleaseRequest();
                        break;
                    }
                case 0x06: {
                        var pdu = new AReleaseRP();
                        pdu.Read(raw);
                        Logger.Log(LogLevel.Info, "{0} <- Association release response", LogID);
                        if (this is IDicomServiceUser)
                            (this as IDicomServiceUser).OnReceiveAssociationReleaseResponse();
                        CloseConnection(0);
                        break;
                    }
                case 0x07: {
                        var pdu = new AAbort();
                        pdu.Read(raw);
                        Logger.Log(LogLevel.Info, "{0} <- Abort: {1} - {2}", LogID, pdu.Source, pdu.Reason);
                        if (this is IDicomServiceProvider)
                            (this as IDicomServiceProvider).OnReceiveAbort(pdu.Source, pdu.Reason);
                        else if (this is IDicomServiceUser)
                            (this as IDicomServiceUser).OnReceiveAbort(pdu.Source, pdu.Reason);
                        CloseConnection(0);
                        break;
                    }
                case 0xFF: {
                        break;
                    }
                default:
                    throw new DicomNetworkException("Unknown PDU type");
                }

                BeginReadPDUHeader();
            } catch (IOException e) {
                int error = 0;
                if (e.InnerException is SocketException) {
                    error = (e.InnerException as SocketException).ErrorCode;
                    Logger.Error("Socket error while reading PDU: {0} [{1}]", (e.InnerException as SocketException).SocketErrorCode, (e.InnerException as SocketException).ErrorCode);
                } else if (!(e.InnerException is ObjectDisposedException))
                    Logger.Error("IO exception while reading PDU: {0}", e.ToString());

                CloseConnection(error);
            } catch (Exception e) {
                Logger.Log(LogLevel.Error, "Exception processing PDU: {0}", e.ToString());
                CloseConnection(0);
            }
        }