IPv4 socket lookup support

modulename: nf_socket_ipv4.ko

configname: CONFIG_NF_SOCKET_IPV4

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>IP: Netfilter Configuration
└─>IPv4 socket lookup support
In linux kernel since version 4.1 (release Date: 2015-06-21)  
This option enables the IPv4 socket lookup infrastructure. This is
is required by the {ip,nf}tables socket match.

source code:
net/ipv4/netfilter/nf_socket_ipv4.c