U32 key

modulename: em_u32.ko

configname: CONFIG_NET_EMATCH_U32

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>QoS and/or fair queueing
└─>U32 key
In linux kernel since version 2.6.12  
Say Y here if you want to be able to classify packets using
the famous u32 key in combination with logic relations.

To compile this code as a module, choose M here: the
module will be called em_u32.

source code: