interfacelist.java

DSr project for the java applications

package dsr;



import java.net.*;
import java.util.*;

//this class implements the interface list. It stores the information about all the
//network interfaces available to the OS
public class InterfaceList {
  static Vector interfaceList;     //this is the vector for the interface list

  //constructor
  public InterfaceList() {
    interfaceList = new Vector(3, 2);
    findInterface();
  }

  //this is the function for construcing the interface Entries from the interface information
  //obtained from the OS
  public static void createInterface(String s, int port) {
    //string s contains the interface information
    Vector token = new Vector(3,2);

    //gets the words from the string s
    StringTokenizer st = new StringTokenizer(s, " :;\n");
    String tmp;
    while (st.hasMoreTokens()){
      tmp = st.nextToken();
      token.addElement(tmp);
    }

    int index = 0, add = 1;
    String tempName = "", tempIndex = "";
    InetAddress tempIP;

    //the folowing code goes through the words obtained from the string and
    //extracts the interface name, its index and the ip address associated with it.
    try {
      tempIP = InetAddress.getByName("0.0.0.0");

      if ((index = token.indexOf("name", index)) != -1) {
        tempName = (String)token.elementAt(index+1);

        if ((index = token.indexOf("index", index)) != -1) {
          tempIndex = (String)token.elementAt(index+1);

          if ((index = token.indexOf("addresses", index)) != -1) {
            //gets the type of OS this application is running on
            String osname = System.getProperties().getProperty("os.name");
            System.out.println("You'are using " + osname + " operating system.");

            tmp = (String)token.lastElement();
            //depending on the operating system it extracts the address information
            if (osname.startsWith("Windows")) {
              if (tmp.length() > 1)
                tempIP = InetAddress.getByName(tmp.substring(1, tmp.length()));
              else
                add = 0;
            }
            else if (osname.startsWith("SunOS")) {
              tempIP = InetAddress.getByName(tmp.substring(1, tmp.length()));
            }
          }
        }
      }

      //don't want to enter the loop back address.
      if (!tempName.equals("lo0") && (add == 1) ) {
        System.out.println(tempName + " " + tempIndex + " " + tempIP.toString());
        try {
          //creates the interface entry and adds it to the interface table
          interfaceList.addElement(new InterfaceListEntry(tempIP, tempName, tempIndex, port));
        } catch (NullPointerException e) {}
        //adds the interface information in the routing table as a self route
        addInterfaceToRoutingTable((InterfaceListEntry)interfaceList.lastElement());
        add = 0;
      }
    } catch (UnknownHostException e) {}
  }

  //checks to see if the ip address is one of my interface addresses.
  public static boolean checkIfInterfacePresent(InetAddress addr) {
    Iterator i = interfaceList.iterator();
    while (i.hasNext()) {
      InterfaceListEntry tmp = new InterfaceListEntry((InterfaceListEntry)i.next());
      if (tmp.ipAddress.equals(addr)) {
        return true;
      }
    }
    return false;
  }

  //adds an interface to the routing table. basically adds the self route
  public static void addInterfaceToRoutingTable(InterfaceListEntry tmpEntry){
    if (!RouteTable.IfEntryPresentInRouteTable(tmpEntry))
      RouteTable.AddRouteTableEntry(new RouteTableEntry
                                    (tmpEntry.ipAddress, tmpEntry.ipAddress, (byte)0, (byte)1));
  }

  //this is the function that initiates the discovery of the interfaces.
  //it gets the network interfaces in the form of strings and then calls the
  //createInterface() to extracts the interface information
  public static void findInterface() {
    try {
      for (Enumeration e = NetworkInterface.getNetworkInterfaces() ; e.hasMoreElements() ;) {
        String s;
        s = e.nextElement().toString();
        System.out.println(s);
        createInterface(s, 6666);
        System.out.println();
      }
    } catch (SocketException ei){}

    //prints out the interface table
    Iterator vItr = interfaceList.iterator();
    System.out.println("\nElements in vector");
    while (vItr.hasNext()){
      System.out.println(((InterfaceListEntry)vItr.next()).toString());
    }
    /*
    vItr = RouteTable.routingTable.iterator();
    System.out.println("elements in routing table");
    while(vItr.hasNext()) {
      System.out.println(((RouteTableEntry)vItr.next()).toString());
    }
*/
  }
}



/*
  public static void main (String[] args){

    try {
      for (Enumeration e = NetworkInterface.getNetworkInterfaces() ; e.hasMoreElements() ;) {
        String s;
        s = e.nextElement().toString();
        System.out.println(s);
        createInterface(s, 6666);
        System.out.println();
      }
    } catch (SocketException ei){}

    Iterator vItr = interfaceList.iterator();

    while (vItr.hasNext()){
      System.out.println("\nElements in vector");
      System.out.println(((InterfaceListEntry)vItr.next()).toString());
    }

    vItr = RouteTable.routingTable.iterator();
    while(vItr.hasNext()) {
      System.out.println("elements in routing table");
      System.out.println(((RouteTableEntry)vItr.next()).toString());
    }
  }
}
    /*
    Enumeration vEnum = interfaceList.elements();
    System.out.println("\nElements in vector");
    while (vEnum.hasMoreElements()) {
     System.out.println(((InterfaceList)vEnum.nextElement()).toString());
    }

      // TODO: Add initialization code here
  }

}
*/