CH_NO_HWCKSUM
CH_NO_CPL: CH_NO_HWCKSUM|CH_NO_CPL;
flg = CH_NO_HWCKSUM | CH_NO_CPL;
flg & CH_NO_HWCKSUM; /* CH_NO_HWCKSUM == 1 */
if ((flg & CH_NO_HWCKSUM) == 0) {
if ((flg & CH_NO_HWCKSUM) == 0) {