Re: nft typeof keywork patch

[Florian Westphal <fw@strlen.de>]

> > Wait, so
> >     nft add set ip filter set1 { typeof ip saddr;}
> > 
> > then it should not list
> >     nft add set ip filter set1 { type ipv4_addr;}
> > 
> > but the exact input using the typeof()?
> > 
> > I wonder how to encode this, especially given we also need to support
> > concatenation, e.g.

I've started with this, first item i am working on is to change
struct set to pass in struct expr *key instead of datatype+len to make
the original expression (meta iifname for example) available to the
linerize parts so we can stash this info in the udata.

For "typeof(meta iifname) . mark" case the parser will generate a concat
expression, and, since these keep the original expr around we can
iterate over that list to get back the original expressions.

For the normal 'type' case, i think we can simply use a dummy
constant expression to serve as a container for the data type.

What do you think?