[dpdk-dev] L4 rx checksum verification in tun/tap pmd

[Jacques Fourie]

Hi,

I noticed that TCP rx checksum verification fails when using the tap pmd.
In this particular case packets with correct checksums will always have
PKT_RX_L4_CKSUM_BAD set in ol_flags. The rte_ipv4_udptcp_cksum() and
rte_ipv6_udptcp_cksum() functions already return the ones complement of the
checksum, unlike rte_raw_cksum(), which is used for the L3 checksum
verification. After changing the code to use rte_ipv4_udptcp_cksum()
instead of ~rte_ipv4_udptcp_cksum() the problem seems to be fixed. The same
thing goes for rte_ipv6_udptcp_cksum().

Regards,
Jacques