libnetfilter_acct is the userspace library that provides a programming interface (API) to the extended accounting infrastructure. Basically, you can find here a set of helper functions that you can use together with libmnl.
libnetfilter_acct homepage is: http://netfilter.org/projects/libnetfilter_acct/
libnetfilter_acct requires libmnl >= 1.0.0 and the Linux kernel that includes the nfnetlink_acct subsystem (i.e. 3.3.x or any later).
The current development version of libnetfilter_acct can be accessed at https://git.netfilter.org/cgi-bin/gitweb.cgi?p=libnetfilter_acct.git
To write your own program using libnetfilter_acct, you should start by reading the documentation for libmnl to understand basic operation with Netlink sockets. Moreover, you may want to check the examples available under examples/ in the libnetfilter_acct source code. You can compile these examples by invoking `make check'.
libnetfilter_acct has been written by Pablo Neira Ayuso.