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The "libnfnetlink" project

What is libnfnetlink?

libnfnetlink is the low-level library for netfilter related kernel/userspace communication. It provides a generic messaging infrastructure for in-kernel netfilter subsystems (such as nfnetlink_log, nfnetlink_queue, nfnetlink_conntrack) and their respective users and/or management tools in userspace.

This library is not meant as a public API for application developers. It is only used by other projects, such as libnetfilter_log, libnetfilter_queue or libnetfilter_conntrack.


libnfnetlink requires a kernel that features the nfnetlink subsystem. This includes all kernels >= 2.6.14.

Main Features

  • low-level nfnetlink message processing functions

Git Tree

The current development version of libnfnetlink can be accessed at


libnfnetlink was mostly written by the netfilter core team, with some contributions from Pablo Neira Ayuso.

Copyright © 1999-2014 Harald Welte, Pablo Neira Ayuso . Pablo Neira Ayuso