If a device's feature is set to NETIF_F_HW_CSUM
, then the network stack does not compute the transport checksum on the transmit path. Instead, it tells the device to compute the checksum by setting ip_summed
to CHECKSUM_PARTIAL
.
The device shall use csum_start
(or skb_checksum_start_offset(skb)
occasionally) as the starting position and compute the checksum till the end of the packet (len
field in socket buffer). The computed checksum is stored at csum_offset
from csum_start
.