csu3_am335x/EVSE/GPL/iptables-1.4.18/extensions/libxt_nfacct.man

The nfacct match provides the extended accounting infrastructure for iptables.
You have to use this match together with the standalone user-space utility
.B nfacct(8)
.PP
The only option available for this match is the following:
.TP
\fB\-\-nfacct\-name\fP \fIname\fP
This allows you to specify the existing object name that will be use for
accounting the traffic that this rule-set is matching.
.PP
To use this extension, you have to create an accounting object:
.IP
nfacct add http\-traffic
.PP
Then, you have to attach it to the accounting object via iptables:
.IP
iptables \-I INPUT \-p tcp \-\-sport 80 \-m nfacct \-\-nfacct\-name http\-traffic
.IP
iptables \-I OUTPUT \-p tcp \-\-dport 80 \-m nfacct \-\-nfacct\-name http\-traffic
.PP
Then, you can check for the amount of traffic that the rules match:
.IP
nfacct get http\-traffic
.IP
{ pkts = 00000000000000000156, bytes = 00000000000000151786 } = http-traffic;
.PP
You can obtain
.B nfacct(8)
from http://www.netfilter.org or, alternatively, from the git.netfilter.org
repository.