Re: [PATCH nft v2 3/3] src: add xt compat support

[Florian Westphal <fw@strlen.de>]

Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> On Thu, Apr 09, 2015 at 10:51:35PM +0200, Florian Westphal wrote:
> > Why would I want to re-write a working nft+compat ruleset to one
> > that only uses native expressions?
> 
> The fact is that we cannot push users to use nf_tables, but we can
> provide good reasons to adopt the native replacements and tools to
> migrate easily.

I think dictionaries are a pretty good reason :-)

> > Whats the point of providing a 'native' replacement for an existing xtables
> > target if we can just use the xtables version?
> 
> Have a look a hashlimit, multiport and all of our existing combo
> match/targets.  They are a mess. We're now going towards a way more
> flexible and generic (lego fashion) framework that will provide all
> kind of combos without relying on this kind of Frankenstein
> extensions.

Sure, but do you really want to add native expression equivalents for
things like quota match, '-m time', '-j CLUSTERIP' ... ?

And wrt. the existing combos, are you positive that your xlate tool
will always be able to translate everything to nft native expressions?

I'm specifically thinking about side-effects, e.g. -m recent which can
also be manipulated externally to ruleset via /proc...

So i am afraid that 100% compat is not doable except by retaining all
matches/targets (or at least some of them).