Description:

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 netfilter.org projects, such as libnetfilter_log,
libnetfilter_queue or libnetfilter_conntrack.