nflog-bindings was written to provide an interface in high-level languages such as Perl or Python to libnetfilter_log. The goal is to provide a library to gain access to packets queued by the kernel packet filter.

It is important to note that these bindings will not follow blindly libnetfilter_log API. For ex., some higher-level wrappers will be provided for the open/bind/create mechanism (using one function call instead of three).

Since libraries to decode ip packets are already available, the bindings will use them.

Remember that an application connection to libnetfilter_log must run as root to be able to create the queue. Some extra steps may be required to drop privileges after if you need more security.

You must add rules in netfilter to send packets to the userspace queue. The number of the queue (--nflog-group option in netfilter) must match the number provided to create_queue().

Example of iptables rules::

iptables -A OUTPUT --destination 1.2.3.4 -j NFLOG --nflog-group 1

Of course, you should be more restrictive, depending on your needs.