Re: [nf-next] netfilter: extend SRH match to support matching previous, next and last SID

[Florian Westphal <fw@strlen.de>]

Ahmed Abdelsalam <amsalam20@gmail.com> wrote:
> > > @@ -50,6 +62,12 @@ struct ip6t_srh {
> > >  	__u8                    segs_left;
> > >  	__u8                    last_entry;
> > >  	__u16                   tag;
> > > +	struct in6_addr		psid_addr;
> > > +	struct in6_addr		nsid_addr;
> > > +	struct in6_addr		lsid_addr;
> > > +	struct in6_addr		psid_msk;
> > > +	struct in6_addr		nsid_msk;
> > > +	struct in6_addr		lsid_msk;
> > 
> > This is changing something exposed through UAPI, so you will need a
> > new revision for this.
> 
> Could you please advice what should be done in this case? 

You need to add
struct ip6t_srh_v1 {
	/* copy of struct ip6t_srh here */

	/* new fields go here */
};


Look at xt_conntrack.c, conntrack_mt_reg[] for an example of
multi-revision match.

You can probably re-origanise code to avoid too much duplication.
See 5a786232eb69a1f870ddc0cfd69d5bdef241a2ea in nf.git for an example,
it makes v0 into a v1 struct at runtime and re-uses new v1 code
for old v0.