Esempio n. 1
0
        private void ProcessTcpRequestAsync(object parameter)
        {
            Socket      tcpSocket = parameter as Socket;
            DnsDatagram request   = null;

            try
            {
                NetworkStream recvStream         = new NetworkStream(tcpSocket);
                OffsetStream  recvDatagramStream = new OffsetStream(recvStream, 0, 0);
                MemoryStream  sendBufferStream   = null;
                byte[]        sendBuffer         = null;
                ushort        length;

                while (true)
                {
                    //read dns datagram length
                    {
                        byte[] lengthBuffer = recvStream.ReadBytes(2);
                        Array.Reverse(lengthBuffer, 0, 2);
                        length = BitConverter.ToUInt16(lengthBuffer, 0);
                    }

                    //read dns datagram
                    recvDatagramStream.Reset(0, length, 0);
                    request = new DnsDatagram(recvDatagramStream);

                    DnsDatagram response = ProcessQuery(request, tcpSocket.RemoteEndPoint);

                    //send response
                    if (response != null)
                    {
                        if (sendBufferStream == null)
                        {
                            sendBufferStream = new MemoryStream(64);
                        }

                        //write dns datagram
                        sendBufferStream.Position = 0;
                        response.WriteTo(sendBufferStream);

                        //prepare final buffer
                        length = Convert.ToUInt16(sendBufferStream.Position);

                        if ((sendBuffer == null) || (sendBuffer.Length < length + 2))
                        {
                            sendBuffer = new byte[length + 2];
                        }

                        //copy datagram length
                        byte[] lengthBuffer = BitConverter.GetBytes(length);
                        sendBuffer[0] = lengthBuffer[1];
                        sendBuffer[1] = lengthBuffer[0];

                        //copy datagram
                        sendBufferStream.Position = 0;
                        sendBufferStream.Read(sendBuffer, 2, length);

                        //send dns datagram
                        tcpSocket.Send(sendBuffer, 0, length + 2, SocketFlags.None);

                        LogManager queryLog = _queryLog;
                        if (queryLog != null)
                        {
                            queryLog.Write(tcpSocket.RemoteEndPoint as IPEndPoint, true, request, response);
                        }

                        StatsManager stats = _stats;
                        if (stats != null)
                        {
                            stats.Update(response, (tcpSocket.RemoteEndPoint as IPEndPoint).Address);
                        }
                    }
                }
            }
            catch (IOException)
            {
                //ignore IO exceptions
            }
            catch (Exception ex)
            {
                LogManager queryLog = _queryLog;
                if ((queryLog != null) && (request != null))
                {
                    queryLog.Write(tcpSocket.RemoteEndPoint as IPEndPoint, true, request, null);
                }

                LogManager log = _log;
                if (log != null)
                {
                    log.Write(tcpSocket.RemoteEndPoint as IPEndPoint, ex);
                }
            }
            finally
            {
                if (tcpSocket != null)
                {
                    tcpSocket.Dispose();
                }
            }
        }
Esempio n. 2
0
        private void ProcessUdpRequestAsync(object parameter)
        {
            object[] parameters = parameter as object[];

            EndPoint    remoteEP = parameters[0] as EndPoint;
            DnsDatagram request  = parameters[1] as DnsDatagram;

            try
            {
                DnsDatagram response = ProcessQuery(request, remoteEP);

                //send response
                if (response != null)
                {
                    byte[]       sendBuffer       = new byte[512];
                    MemoryStream sendBufferStream = new MemoryStream(sendBuffer);

                    try
                    {
                        response.WriteTo(sendBufferStream);
                    }
                    catch (NotSupportedException)
                    {
                        DnsHeader header = response.Header;
                        response = new DnsDatagram(new DnsHeader(header.Identifier, true, header.OPCODE, header.AuthoritativeAnswer, true, header.RecursionDesired, header.RecursionAvailable, header.AuthenticData, header.CheckingDisabled, header.RCODE, header.QDCOUNT, 0, 0, 0), response.Question, null, null, null);

                        sendBufferStream.Position = 0;
                        response.WriteTo(sendBufferStream);
                    }

                    //send dns datagram
                    _udpListener.SendTo(sendBuffer, 0, (int)sendBufferStream.Position, SocketFlags.None, remoteEP);

                    LogManager queryLog = _queryLog;
                    if (queryLog != null)
                    {
                        queryLog.Write(remoteEP as IPEndPoint, false, request, response);
                    }

                    StatsManager stats = _stats;
                    if (stats != null)
                    {
                        stats.Update(response, (remoteEP as IPEndPoint).Address);
                    }
                }
            }
            catch (Exception ex)
            {
                LogManager queryLog = _queryLog;
                if (queryLog != null)
                {
                    queryLog.Write(remoteEP as IPEndPoint, false, request, null);
                }

                LogManager log = _log;
                if (log != null)
                {
                    log.Write(remoteEP as IPEndPoint, ex);
                }
            }
        }