#!/bin/bash
#========================================================================================
##
##          FILE:  t-shaping
##
##   DESCRIPTION:  Throttles bandwidth for the specified interface/IP. Designed to be 
##		   placed in /etc/init.d and made executable.
##
##        AUTHOR: Scott Sullivan (ssullivan), ssullivan@liquidweb.com
##       COMPANY: Liquid Web, Inc.
##=======================================================================================

tc_cmd=/sbin/tc
interface=eth0  
download=200mbit
upload=200mbit 
ip=10.30.104.4
U32="$tc_cmd filter add dev $interface protocol ip parent 1:0 prio 1 u32" 

#===  FUNCTION  ================================================================
##          NAME:  exists
##   DESCRIPTION:  Ensures passed command is in the path.
##    PARAMETERS:  none
##       RETURNS:  none
##===============================================================================
function exists {
        if command -v $1 &>/dev/null
        then
                return 1
        else
                echo "$1 was not found, please ensure $1 is installed and in the PATH."
                exit 255
        fi
}

#===  FUNCTION  ================================================================
##          NAME:  status
##   DESCRIPTION:  Show traffic shaping status, directly from tc.
##    PARAMETERS:  none
##       RETURNS:  none
##===============================================================================
status() {
        $tc_cmd -s qdisc ls dev $interface
}

#===  FUNCTION  ================================================================
##          NAME:  restart
##   DESCRIPTION:  Restart traffic shaping.
##    PARAMETERS:  none
##       RETURNS:  none
##===============================================================================
restart() {
        stop
        sleep 2
        start
}

#===  FUNCTION  ================================================================
##          NAME:  stop
##   DESCRIPTION:  Stop traffic shaping.
##    PARAMETERS:  none
##       RETURNS:  none
##===============================================================================
stop() {
        $tc_cmd qdisc del dev $interface root
}

#===  FUNCTION  ================================================================
##          NAME:  start
##   DESCRIPTION:  Start traffic shaping.
##    PARAMETERS:  none
##       RETURNS:  none
##===============================================================================
start() {
	$tc_cmd qdisc add dev $interface root handle 1: htb default 30
	$tc_cmd class add dev $interface parent 1: classid 1:1 htb rate $download
	$tc_cmd class add dev $interface parent 1: classid 1:2 htb rate $upload
	$U32 match ip dst $ip/32 flowid 1:1
	$U32 match ip src $ip/32 flowid 1:2
}

exists tc

case "$1" in
start)
echo -n "Starting traffic shaping: "
start
echo -e '\E[0;32m'"OK"
;;
stop)
echo -n "Stopping traffic shaping: "
stop
echo -e '\E[0;32m'"OK"
;;
restart)
echo -n "Restarting traffic shaping: "
restart
echo -e '\E[0;32m'"OK"
;;
status)
echo "Traffic shaping status for $interface:"
status
echo ""
;;
*)
pwd=$(pwd)
echo "Usage: $0 {start|stop|restart|status}"
;;
esac