traffic_policer.xl

import "pkt_headers.xlh";

Stage connection {
	// Initialized to 0
	
	Register global BQ, frequency;
	Register Tmin, Tmax;

    Action drop {
        sendPacket(255,0);
    }

	setFlowKey(ipv4.src);

	State initial init {
		on (pktRcvd){
			BQ = 0xffa0;
			frequency = 0x40;
			Tmin = currentTime - BQ; 
			Tmax = currentTime + frequency;
			sendPacket(255, 1);
			setNextState(established);
		}
	}

	State established {
	    on (pktRcvd){
		    if (currentTime <= Tmin) {
			    drop();
		    }            
	 

            if (Tmin < currentTime, currentTime <= Tmax) {
                Tmin = Tmin + frequency; 
                Tmax = Tmax + frequency;
                sendPacket(255, 1);
            }

            if (currentTime > Tmax) {
                Tmin = currentTime - BQ; 
                Tmax = currentTime + frequency;
                sendPacket(255, 1);
            }
		}
	}
}