Hi,

You might have to use ProtocolCodecFilter at least. Check this out:
http://mina.apache.org/tutorial-on-protocolcodecfilter-for-mina-2x.html

regards,
Irek

On Mon, Jun 13, 2011 at 2:14 PM, Abhishek Chavan <
[email protected]> wrote:

> Hi Emmanuel,
> I am using a simple telnet client command to send the data. I have attached
> the code below for Server and of the messageReceived Method. I don't think
> there is much change to be done to fix this server side but I noticed that
> if I use the filterchain with TextLineCodecFactory I don't see the issue. I
> also checked the Network Traffic with Wireshark on the port and found that
> only the data I was sending was getting transferred not the null Padded
> bytes.
>
> Server Code::
>
>                try {
>                        IoAcceptor acceptor = new NioSocketAcceptor();
>                        acceptor.getFilterChain().addLast("logger", new
> LoggingFilter());
>                        acceptor.setHandler(this);
>                        acceptor.getSessionConfig().setReadBufferSize(2048);
>                        // acceptor.getSessionConfig().setIdleTime(
> IdleStatus.BOTH_IDLE, 10
>                        // );//NO IDLE Time for our case
>                        PORT =4000;
>                        acceptor.bind(new InetSocketAddress(PORT));
>                } catch (Exception e) {
>                        e.printStackTrace();
>                        System.err.println("Shutting down");
>                }
>
>
> Acceptor Method::
>        @Override
>        public void messageReceived(IoSession session, Object message)
> throws Exception {
>                if (message instanceof IoBuffer) {
>                        IoBuffer buffer = (IoBuffer) message;
>                        SocketAddress remoteAddress =
> session.getRemoteAddress();
>                        byte[] bufferArray = buffer.array();
>                        // System.out.println(new String(bufferArray));
>                        logger.info("Writing Byte Request from {}. Data is:
> '{}'", "", new String(bufferArray));
>
>
>                        StringBuffer strBuffer = new StringBuffer();
>                        strBuffer.append("Bytes from PDM : ");
>                        StringBuffer strBuffer2 = new StringBuffer("BYTE
> DATA IN  {");
>                        for (int i = 0; i < bufferArray.length; i++) {
>                                strBuffer.append(" [" + i + ":" +
> bufferArray[i] + " ] , ");
>                                strBuffer2.append("," + bufferArray[i]);
>                        }
>                        strBuffer2.append("}");
>                        logger.info(strBuffer2.toString());
>                        logger.info(strBuffer.toString());
>
>                        logger.info("Machine Address is : " +
> remoteAddress);
>                 }
>
>        }
>
> Thanks & Regards
> Abhishek Chavan
> Member Architecture Group
> Nagarro Software Pvt. Ltd.
> PH: +919953541323
>
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>
> -----Original Message-----
> From: Emmanuel Lecharny [mailto:[email protected]]
> Sent: Monday, June 13, 2011 6:22 PM
> To: [email protected]
> Subject: Re: TCP Null Packets
>
> Hi,
>
> On Mon, Jun 13, 2011 at 9:53 AM, Abhishek Chavan <
> [email protected]> wrote:
>
> > Dear All,
> >
> > I have created a simple TCP Server using Apache Mina with only "logging"
> as
> > a  filterchain. I am trying to read data sent by clients to my server. I
> am
> > receiving the data however I am also getting a lot of Null byte data in
> the
> > packet. I searched the Forums and found that this is a sign of Malicious
> > Acticity. I am using TCP test Tool as my client as well as Telnet. How
> can
> > I
> > fix this problem?
> >
>
> First, it has to be a problem. It's difficult to tell with the information
> you are providing.
>
> However, if you consider that the received null bytes are malicious, then
> close the asociated session when you detect such an activity. It should do
> the trick
>
>
>
> --
> Regards,
> Cordialement,
> Emmanuel Lécharny
> www.iktek.com
>
>

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