import java.net.DatagramPacket; import javax.swing.*; import java.awt.*; import java.awt.event.*; import java.net.*; import java.io.*; public class evo_udp{ Thread thread; DatagramSocket socket; String test = new String(); public static void main(String[] args) { evo_udp u = new evo_udp(); } public evo_udp(){ new StartThread(); } public class StartThread implements Runnable{ StartThread(){ thread = new Thread(this); thread.start(); } public void StopThread() { thread.interrupted(); socket.close(); } public void run(){ try{ // receive buffer byte[] buffer = new byte[20]; // send buffer byte[] sbuffer = new byte[20]; // listen to this port int port = 1235; String c = null; int ret = 0; //try executing command and return value try{ //run the command echo 66 see if 66 comes back on windows //Process p = Runtime.getRuntime().exec( // "cmd /c e:\\runme 66"); Process p = Runtime.getRuntime().exec( "./check_evo.bat"); //System.out.println(p); BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream())); BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream())); //read the output from the command System.out.println("Here is the standard output of the command:\n"); while ((c = stdInput.readLine()) != null) { //System.out.println("Here 3:\n"); System.out.println(c); ret = Integer.valueOf(c).intValue(); //System.out.println("Here 4:\n"); } System.out.println("Here 1:\n"); //read any errors from the attempted command while ((c = stdError.readLine()) != null) { System.out.println("Here is the standard error of the command (if any):\n"); System.out.println(c); } System.out.println("Here 2:\n"); //do I need this? //System.exit(0); } catch (IOException e) { System.out.println("Exception happened - here's what I know: "); e.printStackTrace(); //do I need this? //System.exit(-1); } try{ socket = new DatagramSocket(port); while(true){ try{ for (int i=0; i<11; i++ ) { buffer[i]=0; } DatagramPacket packet = new DatagramPacket(buffer, buffer.length ); socket.receive(packet); InetAddress client = packet.getAddress(); byte[] iByte = null; iByte=client.getAddress(); int client_port = packet.getPort(); // uncoment next few System.out lines to see what is received and from who String r = String.format("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x", buffer[0], buffer[1],buffer[2], buffer[3], buffer[4], buffer[5], buffer[6], buffer[7], buffer[8], buffer[9], buffer[10], buffer[11]); String from = new String(); String test = new String(buffer); String ip = new String(); from = "From "+client +" " +client_port; test = test.substring(0,4); // set ip to first 7 characters of ip ip = client.getHostAddress().substring(0,7); //display to screen From IP and Port //System.out.println(from); // display to screen data received in hex //System.out.println(r); // check for END sent from client to exit application if (test.equals("STOP")) { System.out.println("UDP Listener Stopped"); StopThread(); } //set up send back what was received except first 4 bytes int temp = 0; temp=0x000000FF & ((int)buffer[4]); sbuffer[0] = (byte)temp; temp=0x000000FF & ((int)buffer[5]); sbuffer[1] = (byte)temp; temp=0x000000FF & ((int)buffer[6]); sbuffer[2] = (byte)temp; temp=0x000000FF & ((int)buffer[7]); sbuffer[3] = (byte)temp; temp=0x000000FF & ((int)buffer[8]); sbuffer[4] = (byte)temp; temp=0x000000FF & ((int)buffer[9]); sbuffer[5] = (byte)temp; temp=0x000000FF & ((int)buffer[10]); sbuffer[6] = (byte)temp; temp=0x000000FF & ((int)buffer[11]); sbuffer[7] = (byte)temp; //sent data has from ip sbuffer[8] = iByte[0]; sbuffer[9] = iByte[1]; sbuffer[10] = iByte[2]; sbuffer[11] = iByte[3]; //sent data has from port here sbuffer[12]=(byte)((client_port & 0x0000ff00)>>>8); //buf[2] = 51; sbuffer[13]=(byte)((client_port & 0x000000ff)); //buf[3] = -97; bytes are signed. //pad some junk temp=0x000000FF & ((int)0); sbuffer[14] = (byte)temp; temp=0x000000FF & ((int)66); sbuffer[15] = (byte)temp; //# of users //all with 255 will send ? to users //for number of users on server //need to find a way to count # of users //already are connected to server //and pass that here temp=0x000000FF & ((int)0); sbuffer[16] = (byte)temp; temp=0x000000FF & ((int)0); sbuffer[17] = (byte)temp; temp=0x000000FF & ((int)0); sbuffer[18] = (byte)temp; temp=0x000000FF & ((int)0); //sbuffer[19] = (byte)temp; sbuffer[19]=(byte)ret; DatagramPacket sndPkg = new DatagramPacket(sbuffer, 20, client, client_port); // send the data back // easy way to stop certain ip's to enter if (ip.substring(0,3).equals("x.xx")) { continue; } else { // ok now send if not above ip's' socket.send(sndPkg); } // uncomment next system.out few lines to see what is sent back String to = new String(); to = "To "+client+" "+client_port; String s = String.format("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x", sbuffer[0], sbuffer[1],sbuffer[2], sbuffer[3], sbuffer[4], sbuffer[5], sbuffer[6], sbuffer[7], sbuffer[8], sbuffer[9], sbuffer[10], sbuffer[11], sbuffer[12], sbuffer[13], sbuffer[14], sbuffer[15], sbuffer[16], sbuffer[17], sbuffer[18], sbuffer[19]); //display the to info //System.out.println(to); //display the string being sent //System.out.println(s); } catch(UnknownHostException ue){} } } catch(java.net.BindException b){} } catch (IOException e){ System.err.println(e); } } } }