Ubuntu

#!/bin/bash
#
#
#    posted by reborg on The UNIX and Linux Forums
#	(c) 2009 - The UNIX and Linux Forums
#

CONFIGFILE=/etc/bandlimit.conf

RUNDIR=/var/run/bandcap
STATSFILE=/proc/net/dev

AWK=/usr/bin/awk
DATE=/bin/date
IPTABLES=/sbin/iptables
TOUCH=/usr/bin/touch
WHO=/usr/bin/who

NETWORK_BLOCKED=0


block_network() {

	if [[ $NETWORK_BLOCKED -ne 1 ]] ; then
		$IPTABLES -A INPUT -j DROP
		NETWORK_BLOCKED=1
	fi
}

unblock_network() {
	$IPTABLES -D INPUT -j DROP > /dev/null 2>&1
	NETWORK_BLOCKED=0
}


init() {
	
	if [[ -f ${RUNDIR}/pidfile ]] ; then
		exit
	else
		echo $$ > ${RUNDIR}/pidfile
	fi

	

	INTERFACE=$($AWK '$1 == "INTERFACE" {print $2}' $CONFIGFILE)
	USER_BANDWIDTH=$($AWK -v user="$username" '$1 == user { printf "%i\n", $2 * 1024 * 1024 ; exit}' $CONFIGFILE)

	if [[ -z "$USER_BANDWIDTH" ]] ; then
		unblock_network
		CAP_USER=0
		return
	fi
	CAP_USER=1

	$TOUCH ${RUNDIR}/${username}.$($DATE +%m)
		
	[[ -d $RUNDIR ]] || mkdir -p $RUNDIR	

	if [[ ! -f "${RUNDIR}/${username}" ]] ; then
		echo $USER_BANDWIDTH > "${RUNDIR}/$username"
	fi

	REMAINING=$(< "${RUNDIR}/${username}" )
	# note IFS on the next line is '<space><tab>:'
	while IFS='     :' read net bandwidth junk; do
        	if [[ "$net" = "$INTERFACE" ]] ; then
			STARTUP_BANDWIDTH=$bandwidth
		fi
        done < $STATSFILE
	if (( REMAINING > 0 )) ; then
		unblock_network
	fi
	
}

run() {
	while : ; do
		set -- $($WHO)
		
		if [[ $# -lt 1 ]] ; then
			sleep 60
			next
		fi

		if [[ "$1" != "$username" ]] ; then
			username="$1"
			init
		fi

		if [[ $CAP_USER -eq 1 ]] ; then

			while IFS=' 	:' read net bandwidth junk; do
				if [[ "$net" = "$INTERFACE" ]] ; then

					LAST_MONTH=$($DATE -d "last month" +%m)
					if [[ -f ${RUNDIR}/${username}.${LAST_MONTH} ]] ; then
						rm ${RUNDIR}/${username}.${LAST_MONTH}
						$TOUCH ${RUNDIR}/${username}.$($DATE +%m)
						REMAINING=$USER_BANDWIDTH
						STARTUP_BANDWIDTH=$bandwidth
						unblock_network
					fi
			
					(( SESSION = bandwidth - STARTUP_BANDWIDTH ))
					(( REMAINING = REMAINING - SESSION ))
					if (( REMAINING <= 0 )) ; then
						block_network
						echo 0 > ${RUNDIR}/$username
					else
						echo $REMAINING > ${RUNDIR}/$username
					fi
				fi
			done < $STATSFILE
		fi
		sleep 60
	done
}

if [[ ! -f $CONFIGFILE ]] ; then
	echo "No bandwidth limits set" >& 2
	exit 2
fi

run

INTERFACE <iterface name>
<username> <monthly bandwidth limit in megabytes>

INTERFACE wlan0
testuser 100

#!/bin/bash

PIDFILE=/var/run/bandcap/pidfile

case $1 in 
	start)
		if [[ -f "$PIDFILE" ]] ; then
			PID=$(< "$PIDFILE")
			/bin/ps -fp $PID | grep -q userband_limit.sh
			if [[ $? -eq 0 ]] ; then
				echo "User bandwidth limiter already running" >&2
				exit 1
			else
				rm "$PIDFILE"
				$START_COMMAND
			fi
		else
			( /usr/bin/userband_limit.sh & )
		fi
		;;

	stop)
		if [[ -f "$PIDFILE" ]] ; then
			PID=$(< "$PIDFILE")
			/bin/ps -fp $PID | grep -q userband_limit.sh
			if [[ $? -ne 0 ]] ; then
				rm "$PIDFILE"
				echo "User bandwidth limiter already stopped" >&2
				exit 1
			else
				rm "$PIDFILE"
				/bin/kill $PID
			fi
		else
			echo "User bandwidth limiter already stopped" >&2
			exit 1
		fi
		;;
esac

sudo cp userband_limit.sh /usr/bin
sudo cp userband_init.sh /etc/init.d
sudo cp bandlimit.conf /etc
sudo chown root:root /usr/bin/userband_limit.sh /etc/init.d/userband_init.sh /etc/bandlimit.conf
sudo chmod 755 /usr/bin/userband_limit.sh /etc/init.d/userband_init.sh
sudo chmod 644 /etc/bandlimit.conf
cd /etc/rc1.d
sudo ln -s ../init.d/userband_init.sh K99userband
cd /etc/rc3.d
sudo ln -s ../init.d/userband_init.sh S99userband
cd /etc/rc4.d
sudo ln -s ../init.d/userband_init.sh S99userband
cd /etc/rc5.d
sudo ln -s ../init.d/userband_init.sh S99userband

sudo gedit /etc/bandlimit.conf

/etc/init.d/userband_init.sh start