Netfilter nf_tables limit module

modulename: nft_limit.ko

configname: CONFIG_NFT_LIMIT

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>Core Netfilter Configuration
└─>Netfilter nf_tables limit module
In linux kernel since version 3.13 (release Date: 2014-01-19)  
This option adds the "limit" expression that you can use to
ratelimit rule matchings.

source code: