On Mon, Sep 12, 2016 at 02:21:07PM +0200, Florian Westphal wrote: > Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> wrote: > > On Sat, Sep 10, 2016 at 10:01:02PM +0200, Florian Westphal wrote: > > > Hi. > > > > > > Linux has a builtin rp filter for ipv4, but not for ipv6. > > > xtables has rpfilter match for both ipv4 and ipv6. > > > nftables currently does not have such a feature. > > > > > > Any idea on how specific or generic this should be for nft? > > > > > > Current idea is to add 'fib' expression that initially supports > > > lookup of outinterface index for reply direction, i.e.: > > > > > > nft ... fib reply oif ne 0 accept (found something) > > > > Probably use 'fib lookup' instead of 'fib reply'? > > I was thinking that we might want to support lookup in original > direction as well at some point, so 'fib original oif' would do > a route lookup for daddr (fib reply/rpf uses saddr). Then, I'd suggest: fib lookup ip daddr to look up for the route base on the IPv4 destinarion address. If you include the interface, you can express this through a concatenation: fib lookup ip daddr . oif As you are basically looking for the route based on IPv4 address and the output interface, so this boils down to: fib lookup $expr $flags -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html