Re: [PATCH nf-next 3/4] netfilter: move generic TEE code from xtables to nf_tee_ipv{4,6} modules

[Pablo Neira Ayuso <pablo@netfilter.org>]

Hi Patrick,

I'd appreciate your feedback on some small design issue on TEE for
nftables.

Basically, the initial patcheset allows this:

        nft add rule ... tee gateway 1.2.3.4

and
        nft add rule ... tee oifname eth0 gateway 1.2.3.4

then, internally, this takes a NFTA_TEE_GATEWAY attribute that
contains the inet address.

The question is if it's worth passing a register instead to indicate
the gateway, ie. NFTA_TEE_GATEWAY_SREG. Thus, we can use maps to set
this, eg.

    nft add rule ... tee gateway ip saddr map { 4.3.2.1 : 1.2.3.4 }

Then, we have interfaces, but we actually need to subscribe to netdev
events to make sure the pointer to net_device is still valid.

Do you think it's worth the effort? I've been spinning on this when I
remember about nft_queue and I think it would be good to get support
done so we can use maps there too.

Let me know, thanks!