#!/usr/pkg/bin/perl -w
#
# Plugin to monitor the throuhgput of a firewall.
#
# Usage: copy or link into /etc/munin/node.d/
#
# Parameters:
#
#       config   (required)
#       autoconf (optional - used by munin-config)
#
# Config variables:
#
# Magic markers (optional - used by munin-config and some installation
# scripts):
#
#%# family=manual
#%# capabilities=autoconf

if ( $ARGV[0] ) {

    if ( $ARGV[0] eq 'autoconf' ) {
	if (-f '/proc/net/snmp') {
	    print "yes\n";
	    exit 0;
	}
	print "no\n";
	exit 0;

    } elsif ( $ARGV[0] eq 'config' ) {
	print <<EOM;
graph_title Firewall Throughput
graph_args --base 1000 -l 0
graph_vlabel Packets/\${graph_period}
graph_category network
received.label Received
received.draw AREA
received.type DERIVE
received.min 0
forwarded.label Forwarded
forwarded.draw LINE2
forwarded.type DERIVE
forwarded.min 0
EOM
# Is LINE1 better I wonder?  The lines are meant to show how large a
# portion of the total received packets gets forwarded.
# rejected.label rejected
# rejected.draw LINE2
# rejected.type COUNTER
	exit 0;
    }
}

open(F, "/proc/net/snmp");

while (<F>) {
    if (/^Ip: \d/) {
	@ip = split;
	$forwarded = $ip[6];  #forwarded
	$received = $ip[3];   #received
	print "received.value $received\n";
	print "forwarded.value $forwarded\n";

	# This calculation is invalid, the packet may have been
	# destined for the firewall, then the difference is wrong.  If
	# you firewall does not receive traffic itself it is correct
	# though.
	# 
	# print "rejected.value ", $received - $forwarded,"\n";
	last;
    }
}
close(F);

# vim:syntax=perl
