IP: GRE demultiplexer

modulename: gre.ko

configname: CONFIG_NET_IPGRE_DEMUX

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>IP: GRE demultiplexer
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
This is helper module to demultiplex GRE packets on GRE version field criteria.
Required by ip_gre and pptp modules.

source code:
net/ipv4/