Binds the UDP port. More...

Collaboration diagram for protocol.DatagramChannel:

[legend]

Public Member Functions
	DatagramChannel (int localPort)
	Constructor for the DatagramChannel object.
int	getLocalPort ()
	Returns used local UDP port.
void	useSymmetricCipher (SymmetricCipher cipherEngine)
	Sets cipher to be used for PDU ciphering.
SymmetricCipher	getUsedSymmetricCipher ()
	Gets current cipher used for PDU ciphering.
void	addNewPeer (RemotePeer remotePeer)
	Adds new peer to receive incoming PDUs.
boolean	hasRemotePeer ()
	Returns if there is active remote peer.
RemotePeer	getRemotePeer ()
	Returns the remote peer.
boolean	isPearDead (int maxIdleTimeMillis)
	Returns if peer seems to be dead (we are not receiving PDUs from it).
void	removePeer ()
	Detaches peer and all its call from the UDP receiver.
void	stop ()
	Stops PDU receiver thread.
void	run ()
	Receives (and deciphers) PDUs from remote peers in a loop.
void	send (OctetBuffer pdu, InetAddress peerAddr, int peerPort)
	Encrypts and sends PDUs to remote peer.
Protected Member Functions
void	packetDump (byte[] octets, int len, InetAddress addr, int port, boolean incoming)
	Dumps information of a frame (in bytes) to standard error.
Private Attributes
int	localPort
	The local UDP port where datagram socket is bound.
DatagramSocket	udpReceiver
	The UDP receiver socket.
Thread	pduReceiverThread
	The UDP receiver worker thread.
volatile boolean	running
	Indicates that worker thread should be running (receiving datagrams)
RemotePeer	remotePeer
	Current remote peer receiving datagrams from UDP socket.
SymmetricCipher	usedPduCipher
	Currently used symmetric cipher.
Static Private Attributes
static final int	INBOUND_UDP_BUFFER_SIZE = 4096
	The default size for the inbound UDP buffer.

Detailed Description

Binds the UDP port.

Each peer is associated with one DatagramChannel object.

Author:: Mikica B Kocic

Definition at line 24 of file DatagramChannel.java.

Constructor & Destructor Documentation

protocol.DatagramChannel.DatagramChannel ( int localPort )

Constructor for the DatagramChannel object.

Parameters:

localPort local UDP port receiving peer's PDUs

Exceptions:

SocketException	Thrown if the UDP socket cannot be created
UnknownHostException	Thrown if the remoteHost cannot be resolved

Definition at line 55 of file DatagramChannel.java.

References protocol.DatagramChannel.pduReceiverThread, protocol.DatagramChannel.remotePeer, protocol.DatagramChannel.running, protocol.DatagramChannel.udpReceiver, and protocol.DatagramChannel.usedPduCipher.

    {
        this.remotePeer = null;
        this.usedPduCipher = null;

        this.running = false;
        this.localPort = -1;
        
        for( int i = localPort; i < localPort + 100; ++i )
        {
            try {
                this.udpReceiver = new DatagramSocket( i );
                this.localPort = i;
                break;
            } catch( SocketException e ) {
                /* ignore error and continue search for unbound port */
            }
        }
        
        /* If binded UDP port, start worker thread.
         */
        if ( this.localPort > 0 ) 
        {
            Log.trace( "Bound to UDP port " + this.localPort );
            this.running = true;
            pduReceiverThread = new Thread( this, "UDP" );
            pduReceiverThread.setPriority( Thread.MAX_PRIORITY - 1 );
            pduReceiverThread.start ();
        }
    }

Member Function Documentation

void protocol.DatagramChannel.addNewPeer ( RemotePeer remotePeer )

Adds new peer to receive incoming PDUs.

Definition at line 117 of file DatagramChannel.java.

References protocol.DatagramChannel.remotePeer.

Referenced by protocol.RemotePeer.RemotePeer().

    {
        this.remotePeer = remotePeer;
    }

int protocol.DatagramChannel.getLocalPort ( )

Returns used local UDP port.

Definition at line 89 of file DatagramChannel.java.

References protocol.DatagramChannel.udpReceiver.

Referenced by CryptoPhoneApp.acceptIncomingCall(), CryptoPhoneApp.deferredOnInvite(), CryptoPhoneApp.executeCommand(), and CryptoPhoneApp.startKryptofonServices().

    {
        return this.udpReceiver.getLocalPort ();
    }

RemotePeer protocol.DatagramChannel.getRemotePeer ( )

Returns the remote peer.

Definition at line 133 of file DatagramChannel.java.

References protocol.DatagramChannel.remotePeer.

Referenced by CryptoPhoneApp.executeCommand(), CryptoPhoneApp.mainTimerEvent(), and CryptoPhoneApp.sendInstantMessage().

    {
        return this.remotePeer;
    }

SymmetricCipher protocol.DatagramChannel.getUsedSymmetricCipher ( )

Gets current cipher used for PDU ciphering.

Definition at line 109 of file DatagramChannel.java.

References protocol.DatagramChannel.usedPduCipher.

Referenced by CryptoPhoneApp.deferredOnInstantMessage(), and CryptoPhoneApp.sendInstantMessage().

    {
        return this.usedPduCipher;
    }

boolean protocol.DatagramChannel.hasRemotePeer ( )

Returns if there is active remote peer.

Definition at line 125 of file DatagramChannel.java.

References protocol.DatagramChannel.remotePeer.

Referenced by CryptoPhoneApp.acceptIncomingCall(), CryptoPhoneApp.deferredOnAccept(), CryptoPhoneApp.deferredOnBye(), CryptoPhoneApp.deferredOnInvite(), CryptoPhoneApp.deferredOnRing(), CryptoPhoneApp.executeCommand(), and CryptoPhoneApp.tryToVerifyInvitingCall().

    {
        return this.remotePeer != null;
    }

boolean protocol.DatagramChannel.isPearDead ( int maxIdleTimeMillis )

Returns if peer seems to be dead (we are not receiving PDUs from it).

Definition at line 141 of file DatagramChannel.java.

References protocol.RemotePeer.receiverIdleTime(), and protocol.DatagramChannel.remotePeer.

Referenced by CryptoPhoneApp.mainTimerEvent().

    {
        if ( this.remotePeer == null ) {
            return false; // cannot be dead if does not exists
        }
        
        return this.remotePeer.receiverIdleTime () > maxIdleTimeMillis;
    }

void protocol.DatagramChannel.packetDump	(	byte[]	octets,
		int	len,
		InetAddress	addr,
		int	port,
		boolean	incoming
	)		`[protected]`

Dumps information of a frame (in bytes) to standard error.

Parameters:

octets	The octets of the in- or outgoing PDU
len	The size of PDU
addr	The remote host address
port	The port number
incoming	Indicates if it is inbound (true) or outgoing (false) PDU

Definition at line 283 of file DatagramChannel.java.

Referenced by protocol.DatagramChannel.run(), and protocol.DatagramChannel.send().

    {
        if ( ! Log.isEnabled( Log.PDU ) ) {
            return;
        }
        
        StringBuffer sb = new StringBuffer( 500 );
        
        sb.append( incoming ? "Packet from <--- " : "Packet to ---> " );
        
        sb.append( addr.getHostAddress() ).append( ":" ).append( port );
        
        sb.append( ", size = ").append( len ).append( "\n\n" );
        
        sb.append( Log.toHex( octets, len, " " ) ).append( "\n" );
        
        Log.pdu( sb.toString () );
    }

void protocol.DatagramChannel.removePeer ( )

Detaches peer and all its call from the UDP receiver.

Definition at line 153 of file DatagramChannel.java.

References protocol.RemotePeer.cleanUp(), protocol.DatagramChannel.remotePeer, and protocol.DatagramChannel.usedPduCipher.

Referenced by CryptoPhoneApp.deferredOnBye(), and CryptoPhoneApp.executeCommand().

    {
        this.usedPduCipher = null;

        if ( this.remotePeer != null ) 
        {
            this.remotePeer.cleanUp ();
            this.remotePeer = null;
        }
    }

void protocol.DatagramChannel.run ( )

Receives (and deciphers) PDUs from remote peers in a loop.

Dispatches inbound PDUs to associated instance of the RemotePeer that will handle PDUs.

Definition at line 196 of file DatagramChannel.java.

References protocol.RemotePeer.addIncomingPDU(), crypto.SymmetricCipher.decrypt(), protocol.DatagramChannel.INBOUND_UDP_BUFFER_SIZE, protocol.DatagramChannel.packetDump(), protocol.DatagramChannel.remotePeer, protocol.DatagramChannel.running, protocol.DatagramChannel.udpReceiver, and protocol.DatagramChannel.usedPduCipher.

    {
        Log.trace( "Thread started" );

        /* Receive and dispatch datagrams
         */
        byte[] buff = new byte[ INBOUND_UDP_BUFFER_SIZE ];
        
        while( running )
        {
            DatagramPacket packet = new DatagramPacket( buff, buff.length );
            
            try 
            {
                udpReceiver.receive( packet );
                
                byte[] pdu = new byte[ packet.getLength () ];
                System.arraycopy( buff, 0, pdu, 0, pdu.length );

                InetAddress peerAddr = packet.getAddress ();
                int peerPort = packet.getPort ();

                // packetDump( pdu, pdu.length, peerAddr, peerPort, true );
                
                if ( usedPduCipher != null ) {
                    pdu = usedPduCipher.decrypt( /*randomPreambleLen*/ 8, pdu );
                }

                if ( pdu != null ) 
                {
                    packetDump( pdu, pdu.length, peerAddr, peerPort, true );
    
                    if ( remotePeer != null ) {
                        remotePeer.addIncomingPDU( pdu );
                    }
                }
            }
            catch( IOException e )
            {
                if ( running ) {
                    Log.exception( Log.WARN, e );
                }
            }
        }
    }

void protocol.DatagramChannel.send	(	OctetBuffer	pdu,
		InetAddress	peerAddr,
		int	peerPort
	)

Encrypts and sends PDUs to remote peer.

Definition at line 245 of file DatagramChannel.java.

References crypto.SymmetricCipher.encrypt(), utils.OctetBuffer.getPosition(), utils.OctetBuffer.getStore(), protocol.DatagramChannel.packetDump(), protocol.DatagramChannel.udpReceiver, and protocol.DatagramChannel.usedPduCipher.

Referenced by protocol.RemotePeer.send().

    {
        try
        {
            packetDump( pdu.getStore (), pdu.getPosition (), peerAddr, peerPort, false );

            byte[] datagram = new byte[ pdu.getPosition () ];
            System.arraycopy( pdu.getStore (), 0, datagram, 0, datagram.length );
            
            if ( usedPduCipher != null ) {
                datagram = usedPduCipher.encrypt( /*randomPreambleLen*/ 8, datagram );
            }

            if ( datagram != null ) 
            {
                // packetDump( datagram, datagram.length, peerAddr, peerPort, false );
                
                DatagramPacket packet = new DatagramPacket(
                        datagram, datagram.length, peerAddr, peerPort );
    
                this.udpReceiver.send( packet );
            }
        }
        catch( Exception e )
        {
            Log.exception( Log.WARN, e );
        }
    }

void protocol.DatagramChannel.stop ( )

Stops PDU receiver thread.

Definition at line 167 of file DatagramChannel.java.

References protocol.DatagramChannel.pduReceiverThread, protocol.DatagramChannel.running, and protocol.DatagramChannel.udpReceiver.

Referenced by CryptoPhoneApp.stopKryptofonServices().

    {
        running = false;
        
        if ( pduReceiverThread != null )
        {
            udpReceiver.close ();
            Log.debug( "Closed Socket" );
            
            try
            {
                pduReceiverThread.join ();
                Log.debug( "Joined binder thread" );
            }
            catch( InterruptedException e )
            {
                Log.exception( Log.WARN, e );
            }
            
            pduReceiverThread = null;
        }
    }

void protocol.DatagramChannel.useSymmetricCipher ( SymmetricCipher cipherEngine )

Sets cipher to be used for PDU ciphering.

Definition at line 97 of file DatagramChannel.java.

References crypto.SymmetricCipher.getAlgorithmDesc(), and protocol.DatagramChannel.usedPduCipher.

Referenced by CryptoPhoneApp.acceptIncomingCall(), and CryptoPhoneApp.deferredOnAccept().

    {
        usedPduCipher = cipherEngine;
        
        if ( cipherEngine != null ) {
            Log.trace( "Using PDU cipher: " + cipherEngine.getAlgorithmDesc () );
        }
    }