netfilter: nftables: counter hardware offload support

This patch adds the .offload_stats operation to synchronize hardware
stats with the expression data. Update the counter expression to use
this new interface. The hardware stats are retrieved from the netlink
dump path via FLOW_CLS_STATS command to the driver.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
5 files changed