= libnetfilter_acct: area-based accounting for netfilter =

Netfilter provides several accounting mechanisms:

* flow-based accouting through ctnetlink
* packet-based accounting through NFLOG

This library contains the user-space part of a third new mechanism that
provides area-based accounting.

You have to get the kernel part from:

 git clone -b nf git://1984.lsi.us.es/net

Or you can obtain the patches that apply to 3.2-rc from the cgit interface:

 http:/1984.lsi.us.es/git

Make sure you compile the kernel with NFNETLINK_ACCT and XT_TARGET_NFACCT
support.

== Flow-based accounting through ctnetlink ==

This mechanism allows you to account the number of packets and bytes
of one given flow. This information is obtained via netlink event once
the flow is closed with:

 # conntrack -E

You can get real-time accounting packets and bytes per flow by polling:

 # conntrack -L

== Packet-based accounting through NFLOG ==

This mechanism allows you to add specific iptables rules to log packets
that match some specific condition:

 # iptables -I INPUT -p tcp --dport 80 -j LOG --log-prefix "http: "

== Area-based accouting ==

This mechanism allows you to create one accounting area:

 libnetfilter_acct/examples# ./nfacct-create http-traffic

Then, you can use it in iptables:

 # iptables -I INPUT -p tcp --dport 80 -j NFACCT --nfacct-name http-traffic
 # iptables -I OUTPUT -p tcp --sport 80 -j NFACCT --nfacct-name http-traffic

You can obtain the counters via libnetfilter_acct:

 libnetfilter_acct/examples# ./nfacct-get
 http-traffic = { pkts = 000000061152,   bytes = 000082999936 };

You can perform different actions like dumping the counters and reset them.

--
(c) 2011 Pablo Neira Ayuso <pablo@netfilter.org>
(c) 2011 Intra2Net AG <http://www.intra2net.com>