if ( host.indexOf('.') < 0 && host.toUpperCase(Locale.ROOT).equals(host) ) {
            // this is not too good, probably should better pass the address and check that it is a netbios one.
            // While we could look up the domain controller/KDC we cannot really make the java kerberos implementation
            // use a KDC of our choice.

     *
     * @see jcifs.BufferCache#releaseBuffer(byte[])
     */
    @Override
    public void releaseBuffer ( byte[] buf ) {
        if ( buf == null ) {
            return;
        }
        // better safe than sorry: prevent leaks if there is some out of bound access
        Arrays.fill(buf, (byte) 0);
        synchronized ( this.cache ) {
            if ( this.freeBuffers < this.cache.length ) {

                    securityProvider.unwrap(fbuf);

                fbuf.reset();
                msg.decode_header(fbuf);
                stub_frag_len = msg.length - 24;

                if ((off + stub_frag_len) > stub.length) {
                    // shouldn't happen if alloc_hint is correct or greater
                    byte[] tmp = new byte[off + stub_frag_len];
                    System.arraycopy(stub, 0, tmp, 0, off);

                                    throws IOException {
        int n;
        if(( n = readn( in, buffer, bufferIndex, HEADER_LENGTH )) != HEADER_LENGTH ) {
            if( n == -1 ) {
                return -1;
            }
            throw new IOException( "unexpected EOF reading netbios session header" );
        }
        int t = buffer[bufferIndex] & 0xFF;
        return t;
    }

    int type, length;

                    && this.sbuf[ 7 ] == (byte) 'B' ) {
                this.smb2 = true;
                // also read the rest of the header
                int lenDiff = Smb2Constants.SMB2_HEADER_LENGTH - SmbConstants.SMB1_HEADER_LENGTH;
                if ( readn(this.in, this.sbuf, 4 + SmbConstants.SMB1_HEADER_LENGTH, lenDiff) < lenDiff ) {
                    return null;
                }

     * Some fields specify the offset from the beginning of the header. This
     * field should be used for calculating that. This would likely be zero
     * but an implemantation that encorporates the transport header(for
     * efficiency) might use a different initial bufferIndex. For example,
     * to eliminate copying data when writing NbtSession data one might
     * manage that 4 byte header specifically and therefore the initial

    }


    @Override
    public int getHeaderFieldInt ( String header, int def ) {
        handshake();
        return this.connection.getHeaderFieldInt(header, def);
    }


    @Override
    public long getHeaderFieldDate ( String header, long def ) {
        handshake();
        return this.connection.getHeaderFieldDate(header, def);
    }


    @Override

    static final int IN        = 0x0001;
    static final int A         = 0x0001;
    static final int NS        = 0x0002;
    static final int NULL      = 0x000a;

    static final int HEADER_LENGTH = 12;

    // header field offsets
    static final int OPCODE_OFFSET = 2;
    static final int QUESTION_OFFSET = 4;
    static final int ANSWER_OFFSET = 6;
    static final int AUTHORITY_OFFSET = 8;

     * Some fields specify the offset from the beginning of the header. This
     * field should be used for calculating that. This would likely be zero
     * but an implemantation that encorporates the transport header(for
     * efficiency) might use a different initial bufferIndex. For example,
     * to eliminate copying data when writing NbtSession data one might
     * manage that 4 byte header specifically and therefore the initial

        synchronized (BUF) {
            System.arraycopy( sbuf, 0, BUF, 0, 4 + HEADER_LENGTH );
            int size = Encdec.dec_uint16be( BUF, 2 ) & 0xFFFF;
            if (size < (HEADER_LENGTH + 1) || (4 + size) > rcv_buf_size ) {
                throw new IOException( "Invalid payload size: " + size );
            }