"rpfilter" reverse path filter match support

modulename: ip6t_rpfilter.ko

configname: CONFIG_IP6_NF_MATCH_RPFILTER

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>The IPv6 protocol
└─>IPv6: Netfilter Configuration
└─>"rpfilter" reverse path filter match support
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This option allows you to match packets whose replies would
go out via the interface the packet came in.

To compile it as a module, choose M here. If unsure, say N.
The module will be called ip6t_rpfilter.

source code: