HW offload of IP checksum validation and calculation when possible

[sovu]

We should definently use HW capabilities at least for defacto offloads like basic(outer) IP checksums. For Inner IPs should be calculated in OFP, but performance measurements are flawed by this missing offload feature.

Among other things, OFP_PERFORMANCE seems to disable checking of IP header checksum of received packets and put zero checksum to outgoing packets, both of which are violations of the IP protocol standard.

We should drop the influence of OFP_PERFORMANCE to IP checksumming.

Implementation proposal:
We should have with the packet a context indication for checksums (validation for input direction, calculation for output)
When packet is received from ODP we should not have the indication set(if the HW capability is available and enable) so the validation is not necessary.
For output direction if the IP packet goes to ODP/HW and capability is available and set then the checksum calculation is not necessary.

[yangxingwu]

hi, is this feature available now?