The flags argument of mac_hcksum_set() is a combination of the following values:
The full checksum was computed and passed through the value argument.
The full checksum was verified in hardware and is correct.
The partial checksum was computed and passed through the value argument. HCK_PARTIALCKSUM is mutually exclusive with HCK_FULLCKSUM.
The IP header checksum was computed and passed through the value argument.
The IP header checksum was verified in hardware and is correct.