#!/bin/sh
#
# Wildcard-plugin to monitor network interfaces. To monitor an
# interface, link if_<interface> to this file. E.g.
#
#    ln -s /usr/local/libexec/munin/plugins/if_ /etc/munin/plugins/if_eth0
#
# ...will monitor eth0.
#
# To aggregate all network interfaces on the system (except lo0), 
# link if_aggregated to this file.
#
# Any device found in /usr/bin/netstat can be monitored.
#
# Magic markers (optional - used by munin-config and some installation
# scripts):
#
#%# family=auto
#%# capabilities=autoconf suggest


INTERFACE=`basename $0 | sed 's/^if_//g'`

if [ "$1" = "autoconf" ]; then
	if [ -x /usr/bin/netstat ]; then
		echo yes
		exit 0
	else
		echo "no (/usr/bin/netstat not found)"
		exit 1
	fi
fi

if [ "$1" = "suggest" ]; then
	if [ -x /usr/bin/netstat ]; then
		netstat -i -b -n | sed -n -e '/^faith/d' -e '/^lo[0-9]/d' -e '/^pflog/d' -e '/<Link>/s/\** .*//p'
		exit 0
	else
		exit 1
	fi
fi

if [ "$1" = "config" ]; then

	echo "graph_order rbytes obytes" 
	echo "graph_title $INTERFACE traffic"
	echo 'graph_args --base 1000'
	echo 'graph_vlabel bits per ${graph_period} in (-) / out (+)'
	echo 'graph_category network'
	echo "graph_info This graph shows the traffic of the $INTERFACE network interface. Please note that the traffic is shown in bits per second, not bytes."
	echo 'rbytes.label received'
        echo 'rbytes.type DERIVE'
        echo 'rbytes.min 0'
        echo 'rbytes.graph no'
        echo 'rbytes.cdef rbytes,8,*'
        echo 'obytes.label bps'
        echo 'obytes.type DERIVE'
        echo 'obytes.min 0'
	echo 'obytes.negative rbytes'
	echo 'obytes.cdef obytes,8,*'
	echo "obytes.info Traffic sent (+) and received (-) on the $INTERFACE network interface."
	exit 0
fi

if [ "$INTERFACE" = "aggregated" ]; then
	/usr/bin/netstat -i -b -n | grep -v '^lo' | awk '
BEGIN { rsum = 0; osum = 0; }
/<Link>/ {
	if (NF == 5) { 
		rsum += $4; osum += $5;
	} else {
		rsum += $5; osum += $6;
	}
}
END {
	printf "rbytes.value %i\n", rsum;
	printf "obytes.value %i\n", osum;
}'
  
else
	/usr/bin/netstat -i -b -n -I $INTERFACE | awk '
/<Link>/ {
	if (NF == 5) { 
		print "rbytes.value", $4;
		print "obytes.value", $5;
	} else {
		print "rbytes.value", $5;
		print "obytes.value", $6;
	}
}'
fi
