skb_checksum_complete(9) - phpMan
SKB_CHECKSUM_COMPLET(9) Linux Networking SKB_CHECKSUM_COMPLET(9)
skb_checksum_complete - Calculate checksum of an entire packet
__sum16 skb_checksum_complete(struct sk_buff * skb);
packet to process
This function calculates the checksum over the entire packet plus the value of skb->csum.
The latter can be used to supply the checksum of a pseudo header as used by TCP/UDP. It
returns the checksum.
For protocols that contain complete checksums such as ICMP/TCP/UDP, this function can be
used to verify that checksum on received packets. In that case the function should return
zero if the checksum is correct. In particular, this function will return zero if
skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the hardware has already
verified the correctness of the checksum.
Kernel Hackers Manual 4.8. January 2017 SKB_CHECKSUM_COMPLET(9)