datapath: Ensure correct L4 checksum with NAT helpers.

Setting the CHECKSUM_PARTIAL flag before sending to helper mods was
missing the checksum update call ('csum_*_magic()'), which caused
checksum failures with kernels <4.6.  This can mean that the L4
checksum is incorrect when the packet egresses the system.

Rather than adding the missing (IP version dependent) calls, give the
packet a temp skb_dst with RTCF_LOCAL flag not set, which ensures the
skb is properly changed to CHECKSUM_PARTIAL if required and the
modified packet will get the correct checksum when fully processed.

This has tested with FTP NAT helpers on kernel version 3.13.

Signed-off-by: John Hurley <john.hurley@netronome.com>
Acked-by: Jarno Rajahalme <jarno@ovn.org>

0 files changed, 0 insertions, 0 deletions