gcc/libjava/java/net/NetworkInterface.java

/* NetworkInterface.java --
   Copyright (C) 2002, 2003, 2004, 2005  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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terms of your choice, provided that you also meet, for each linked
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this exception to your version of the library, but you are not
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package java.net;

import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Vector;

/**
 * This class models a network interface on the host computer.  A network
 * interface contains a name (typically associated with a specific
 * hardware adapter) and a list of addresses that are bound to it.
 * For example, an ethernet interface may be named "eth0" and have the
 * address 192.168.1.101 assigned to it.
 *
 * @author Michael Koch (konqueror@gmx.de)
 * @since 1.4
 */
public final class NetworkInterface
{
  private String name;
  private Vector<InetAddress> inetAddresses;

  NetworkInterface(String name, InetAddress address)
  {
    this.name = name;
    this.inetAddresses = new Vector(1, 1);
    this.inetAddresses.add(address);
  }

  NetworkInterface(String name, InetAddress[] addresses)
  {
    this.name = name;
    this.inetAddresses = new Vector(addresses.length, 1);

    for (int i = 0; i < addresses.length; i++)
      this.inetAddresses.add(addresses[i]);
  }

  /**
   * Returns the name of the network interface
   *
   * @return The name of the interface.
   */
  public String getName()
  {
    return name;
  }

  /**
   * Returns all available addresses of the network interface
   *
   * If a @see SecurityManager is available all addresses are checked
   * with @see SecurityManager::checkConnect() if they are available.
   * Only <code>InetAddresses</code> are returned where the security manager
   * doesn't throw an exception.
   *
   * @return An enumeration of all addresses.
   */
  public Enumeration<InetAddress> getInetAddresses()
  {
    SecurityManager s = System.getSecurityManager();

    if (s == null)
      return inetAddresses.elements();

    Vector<InetAddress> tmpInetAddresses = new Vector<InetAddress>(1, 1);

    for (Enumeration<InetAddress> addresses = inetAddresses.elements();
         addresses.hasMoreElements();)
      {
	InetAddress addr = addresses.nextElement();
	try
	  {
	    s.checkConnect(addr.getHostAddress(), 58000);
	    tmpInetAddresses.add(addr);
	  }
	catch (SecurityException e)
	  {
	    // Ignore.
	  }
      }

    return tmpInetAddresses.elements();
  }

  /**
   * Returns the display name of the interface
   *
   * @return The display name of the interface
   */
  public String getDisplayName()
  {
    return name;
  }

  /**
   * Returns an network interface by name
   *
   * @param name The name of the interface to return
   * 
   * @return a <code>NetworkInterface</code> object representing the interface,
   * or null if there is no interface with that name.
   *
   * @exception SocketException If an error occurs
   * @exception NullPointerException If the specified name is null
   */
  public static NetworkInterface getByName(String name)
    throws SocketException
  {
    for (Enumeration e = getNetworkInterfaces(); e.hasMoreElements();)
      {
	NetworkInterface tmp = (NetworkInterface) e.nextElement();

	if (name.equals(tmp.getName()))
	  return tmp;
      }

    // No interface with the given name found.
    return null;
  }

  /**
   * Return a network interface by its address
   *
   * @param addr The address of the interface to return
   *
   * @return the interface, or <code>null</code> if none found
   *
   * @exception SocketException If an error occurs
   * @exception NullPointerException If the specified addess is null
   */
  public static NetworkInterface getByInetAddress(InetAddress addr)
    throws SocketException
  {
    for (Enumeration interfaces = getNetworkInterfaces();
         interfaces.hasMoreElements();)
      {
	NetworkInterface tmp = (NetworkInterface) interfaces.nextElement();

	for (Enumeration addresses = tmp.inetAddresses.elements();
	     addresses.hasMoreElements();)
	  {
	    if (addr.equals((InetAddress) addresses.nextElement()))
	      return tmp;
	  }
      }

    throw new SocketException("no network interface is bound to such an IP address");
  }

  static private Collection condense(Collection interfaces) 
  {
    final Map condensed = new HashMap();

    final Iterator interfs = interfaces.iterator();
    while (interfs.hasNext()) {

      final NetworkInterface face = (NetworkInterface) interfs.next();
      final String name = face.getName();
      
      if (condensed.containsKey(name))
	{
	  final NetworkInterface conface = (NetworkInterface) condensed.get(name);
	  if (!conface.inetAddresses.containsAll(face.inetAddresses))
	    {
	      final Iterator faceAddresses = face.inetAddresses.iterator();
	      while (faceAddresses.hasNext())
		{
		  final InetAddress faceAddress = (InetAddress) faceAddresses.next();
		  if (!conface.inetAddresses.contains(faceAddress))
		    {
		      conface.inetAddresses.add(faceAddress);
		    }
		}
	    }
	}
      else
	{
	  condensed.put(name, face);
	}
    }

    return condensed.values();
  }

  /**
   * Return an <code>Enumeration</code> of all available network interfaces
   *
   * @return all interfaces
   * 
   * @exception SocketException If an error occurs
   */
  public static Enumeration<NetworkInterface> getNetworkInterfaces()
    throws SocketException
  {
    Vector<NetworkInterface> networkInterfaces =
      VMNetworkInterface.getInterfaces();

    if (networkInterfaces.isEmpty())
      return null;

    Collection condensed = condense(networkInterfaces);

    return Collections.enumeration(condensed);
  }

  /**
   * Checks if the current instance is equal to obj
   *
   * @param obj The object to compare with
   *
   * @return <code>true</code> if equal, <code>false</code> otherwise
   */
  public boolean equals(Object obj)
  {
    if (! (obj instanceof NetworkInterface))
      return false;

    NetworkInterface tmp = (NetworkInterface) obj;

    return (name.equals(tmp.name) && inetAddresses.equals(tmp.inetAddresses));
  }

  /**
   * Returns the hashcode of the current instance
   *
   * @return the hashcode
   */
  public int hashCode()
  {
    // FIXME: hash correctly
    return name.hashCode() + inetAddresses.hashCode();
  }

  /**
   * Returns a string representation of the interface
   *
   * @return the string
   */
  public String toString()
  {
    // FIXME: check if this is correct
    String result;
    String separator = System.getProperty("line.separator");

    result =
      "name: " + getDisplayName() + " (" + getName() + ") addresses:"
      + separator;

    for (Enumeration e = inetAddresses.elements(); e.hasMoreElements();)
      {
	InetAddress address = (InetAddress) e.nextElement();
	result += address.toString() + ";" + separator;
      }

    return result;
  }
}