* Current position in file
     * 
     * @return current position
     */
    long getFilePointer ();


    /**
     * Seek to new position
     * 
     * @param pos
     */
    void seek ( long pos );


    /**
     * Get the current file length
     * 
     * @return file length
     * @throws SmbException
     */
    long length () throws SmbException;


    /**

     *    <p>
     *    Transforms context based on 512 bits from input block starting
     *    from the offset'th byte.
     *
     *    @param    block    input sub-array.
     *    @param    offset    starting position of sub-array.
     */
    private void transform (byte[] block, int offset) {

        // encodes 64 bytes from input block into an array of 16 32-bit
        // entities. Use A as a temp var.

        this.dis = new DataInputStream(in);
        this.size = in.available();
    }


    public void align ( int mask ) throws IOException {
        int position = this.size - this.dis.available();
        int shift = position & mask - 1;
        if ( mask != 0 && shift != 0 )
            this.dis.skip(mask - shift);
    }


    public int available () throws IOException {

        return new String(src, srcIndex, len, UNI_ENCODING);
    }


    /**
     * @param buffer
     * @param bufferIndex
     * @param maxLen
     * @return position of terminating null bytes
     */
    public static int findUNITermination ( byte[] buffer, int bufferIndex, int maxLen ) {
        int len = 0;

     * @param position
     *            読み込みを開始する位置
     * @return 読み込んだバイト数
     */
    public static int read(final FileChannel channel, final ByteBuffer buffer, final long position) {
        assertArgumentNotNull("channel", channel);
        assertArgumentNotNull("buffer", buffer);

        try {
            return channel.read(buffer, position);
        } catch (final IOException e) {

        "The process cannot access the file because it is being used by another process.",
        "The process cannot access the file because another process has locked a portion of the file.", "The disk is full.",
        "A duplicate name exists on the network.", "The network name cannot be found.", "ERRnomoreconn.", "The file exists.",

    // session service packet types
    static final int SESSION_MESSAGE = 0x00;
    static final int SESSION_REQUEST = 0x81;

    /**
     * 
     */
    public static final int POSITIVE_SESSION_RESPONSE = 0x82;

    /**
     * 
     */
    public static final int NEGATIVE_SESSION_RESPONSE = 0x83;
    static final int SESSION_RETARGET_RESPONSE = 0x84;
    static final int SESSION_KEEP_ALIVE = 0x85;

        "The process cannot access the file because it is being used by another process.",
        "The process cannot access the file because another process has locked a portion of the file.",
        "The disk is full.",
        "A duplicate name exists on the network.",
        "The network name cannot be found.",
        "ERRnomoreconn.",
        "The file exists.",

        } catch( IOException ioe ) {
            close();
            throw ioe;
        }

        switch( type ) {
            case SessionServicePacket.POSITIVE_SESSION_RESPONSE:
                if( log.level > 2 )
                    log.println( "session established ok with " + address );
                return;
            case SessionServicePacket.NEGATIVE_SESSION_RESPONSE:

public abstract class SessionServicePacket { 

    // session service packet types 
    static final int SESSION_MESSAGE = 0x00; 
    static final int SESSION_REQUEST = 0x81; 
    public static final int POSITIVE_SESSION_RESPONSE = 0x82; 
    public static final int NEGATIVE_SESSION_RESPONSE = 0x83; 
    static final int SESSION_RETARGET_RESPONSE = 0x84; 
    static final int SESSION_KEEP_ALIVE = 0x85;