UDP: socket monitoring interface

modulename: udp_diag.ko

configname: CONFIG_INET_UDP_DIAG

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>UDP: socket monitoring interface
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Support for UDP socket monitoring interface used by the ss tool.
If unsure, say Y.

source code:
net/ipv4/udp_diag.c