"realm" match support

modulename: xt_realm.ko

configname: CONFIG_NETFILTER_XT_MATCH_REALM

Linux Kernel Configuration
└─>Networking
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>Core Netfilter Configuration
└─>"realm" match support
In linux kernel since version 2.6.16.30-pre1 (release Date: 2006-09-22)  
This option adds a `realm' match, which allows you to use the realm
key from the routing subsystem inside iptables.

This match pretty much resembles the CONFIG_NET_CLS_ROUTE4 option
in tc world.

If you want to compile it as a module, say M here and read
Documentation/kbuild/modules.txt. If unsure, say `N'.

source code: