int off, flags, length;

        if (buf.length < max_recv)
            throw new IllegalArgumentException("buffer too small");

        if (isStart && !isDirect) { // start of new frag, do trans
            off = in.read(buf, 0, 1024);
        } else {
            off = in.readDirect(buf, 0, buf.length);
        }

        if (buf[0] != 5 && buf[1] != 0)