return hdr;
    }

    // Helper: build SMB2 IOCTL response body (without header) with structureSize=49
    private static byte[] buildIoctlResponseBody(int ctlCode, byte[] fileId, int inputCount, byte[] inputBytes, int outputCount,
            byte[] outputBytes, int ioctlFlags) {
        final int headerLen = 64; // SMB2 header is 64 bytes