IP version independent RPKI filter

[Christoph]

Hello,

the RPKI documentation section has a RPKI ROV example using
an IPv4 specific filter:

https://bird.network.cz/?get_doc&v=20&f=bird-6.html#ss6.13
> roa4 table r4;
> roa6 table r6;
> 
> protocol rpki {
>         debug all;
> 
>         roa4 { table r4; };
>         roa6 { table r6; };
> 
>         # Please, do not use rpki-validator.realmv6.org in production
>         remote "rpki-validator.realmv6.org" port 8282;
> 
>         retry keep 5;
>         refresh keep 30;
>         expire 600;
> }
> 
> filter peer_in_v4 {
>         if (roa_check(r4, net, bgp_path.last) = ROA_INVALID) then
>         {
>                 print "Ignore invalid ROA ", net, " for ASN ", bgp_path.last;
>                 reject;
>         }
>         accept;
> }
> 
> protocol bgp {
>         debug all;
>         local as 65000;
>         neighbor 192.168.2.1 as 65001;
>         ipv4 {
>                 import filter peer_in_v4;
>                 export none;
>         };
> }




We use a transit_in filter that checks the
net.type to decide which roa_check parameter to use:

> filter transit_in {
> 
>         reject_bogon_asns();
>         reject_small_prefixes();
>         reject_bogon_prefixes();
>         reject_long_aspaths();
>         reject_default_route();
> 	enforce_neighbor_asn();
> 	reject_our_networks();
> 
> 	if (net.type = NET_IP4) then {
> 		if (roa_check(r4, net, bgp_path.last) = ROA_INVALID) then
> 		{
> 		        print "Reject RPKI INVALID announcement ", net, " by AS", bgp_path.last;
> 		        reject;
> 		}
> 	} else { 
> 		if (roa_check(r6, net, bgp_path.last) = ROA_INVALID) then
> 		{
> 		        print "Reject RPKI INVALID announcement ", net, " by AS", bgp_path.last;
> 		        reject;
> 		}	
> 	}
> 
>         accept;
> 
> }

Is this significantly less efficient than having separate IPv4/6 filters
that do not need that additional if (net.type = .. ) check?
Or does it not really matter?
If possible I'd prefer a single filter that can be applied to IPv4 and
IPv6 BGP sessions.

thanks,
Christoph