esp6: Support RX checksum with crypto offload

Keep the device's reported ip_summed indication in case crypto
was offloaded by the device. Subtract the csum values of the
stripped parts (esp header+iv, esp trailer+auth_data) to keep
value correct.

Note: CHECKSUM_COMPLETE should be indicated only if skb->csum
has the post-decryption offload csum value.

Signed-off-by: Ariel Levkovich <[email protected]>
Signed-off-by: Ilan Tayari <[email protected]>
Signed-off-by: Steffen Klassert <[email protected]>
2 files changed