Netfilter nf_tables stateful object reference module

modulename: nft_objref.ko

configname: CONFIG_NFT_OBJREF

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>Core Netfilter Configuration
└─>Netfilter nf_tables stateful object reference module
In linux kernel since version 4.1 (release Date: 2015-06-21)  
This option adds the "objref" expression that allows you to refer to
stateful objects, such as counters and quotas.

source code: