IB_DETH_BYTES
cpu_to_be16((IB_BTH_BYTES + IB_DETH_BYTES + payload_size + 7)
IB_DETH_BYTES +
IB_DETH_BYTES +
IB_DETH_BYTES +
IB_DETH_BYTES +
len += IB_DETH_BYTES;
buf = (char *)buf + IB_DETH_BYTES;