nftables nft nested loops

[Jeremy Jackson <jerj@xxxxxxxxxxxx>]

Dear netfilter,

I have a bash script which implements zone-based iptables firewall rules 
similar to firewalld or Cisco PIX.  The key ingredient is the ability to 
iterate over  a list of network interfaces, to create chains and rules 
for every input to output interface combination:

I would like to do this with the nft utility or at least with a 
libnftables C library based utility.

Would a contributed looping construct be welcomed into the nft utility?  
It already has variables.  A minimal implementation would be a single 
keyword "permute-interfaces $iif $oif"

Regards,

Jeremy Jackson