PortScan.java

package io.evercam.network.discovery;

import java.util.ArrayList;

public class PortScan {
    private ArrayList<Port> activePortList;
    private PortScanCallback portScanCallback;

    public PortScan(PortScanCallback portScanCallback) {
	this.portScanCallback = portScanCallback;
    }

    public PortScan() {

    }

    // scan both stand and common ports
    public void start(String ip) throws Exception {
	activePortList = new ArrayList<Port>();
	scanStandardPorts(ip);
	scanCommonPorts(ip);
    }

    private ArrayList<Port> getStandardPortList() {
	ArrayList<Port> portList = new ArrayList<>();
	portList.add(new Port(Port.TYPE_HTTP, 80));
	portList.add(new Port(Port.TYPE_RTSP, 554));
	return portList;
    }

    private void scanPort(String ip, Port port) throws Exception {
	if (Port.isReachable(ip, port.getValue())) {
	    // System.out.println("Active port added: " + ip + ":" + port);
	    port.isActive();
	    activePortList.add(port);

	    if (portScanCallback != null) {
		portScanCallback.onActivePort(port);
	    }
	}
    }

    private void scanStandardPorts(String ip) throws Exception {
	ArrayList<Port> standardPorts = getStandardPortList();

	for (Port port : standardPorts) {
	    scanPort(ip, port);
	}
    }

    /**
     * Scan the common ports that are frequently used by Evercam only when HTTP
     * port(80) or RTSP port(554) is not open
     */
    private void scanCommonPorts(String ip) throws Exception {
	String subIp = ip.substring(ip.lastIndexOf(".") + 1, ip.length());
	int subIpInt = Integer.parseInt(subIp);

	ArrayList<String> activePortTypes = new ArrayList<>();
	for (Port port : activePortList) {
	    activePortTypes.add(port.getType());
	}

	if (!activePortTypes.contains(Port.TYPE_HTTP)) {
	    Port commonHttpPort = new Port(Port.TYPE_HTTP, 8000 + subIpInt);
	    scanPort(ip, commonHttpPort);
	}
	if (!activePortTypes.contains(Port.TYPE_HTTP)) {
	    Port commonRtspPort = new Port(Port.TYPE_RTSP, 9000 + subIpInt);
	    scanPort(ip, commonRtspPort);
	}
    }

    public ArrayList<Port> getActivePorts() throws EvercamException {
	if (activePortList != null) {
	    return activePortList;
	} else {
	    throw new EvercamException(
		    EvercamException.MSG_PORT_SCAN_NOT_STARTED);
	}
    }
}