Possibly worth mentioning that without this fix you can also end up
with valid udp packets being dropped (ie. the reverse of the commit
description which talks about receiving invalid ones).
The (approximate?) requirement is:
(a) nic generates CHECKSUM_COMPLETE, but gets the actual checksum wrong
From: Sean Tranchetti
Date: Tue, 23 Oct 2018 16:04:31 -0600
> Current handling of CHECKSUM_COMPLETE packets by the UDP stack is
> incorrect for any packet that has an incorrect checksum value.
>
> udp4/6_csum_init() will both make a call to
> __skb_checksum_validate_complete() to
Current handling of CHECKSUM_COMPLETE packets by the UDP stack is
incorrect for any packet that has an incorrect checksum value.
udp4/6_csum_init() will both make a call to
__skb_checksum_validate_complete() to initialize/validate the csum
field when receiving a CHECKSUM_COMPLETE packet. When
