/***************************************************************************
* Copyright 2006-2016 by Christian Ihle *
* contact@kouchat.net *
* *
* This file is part of KouChat. *
* *
* KouChat is free software; you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as *
* published by the Free Software Foundation, either version 3 of *
* the License, or (at your option) any later version. *
* *
* KouChat 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 *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with KouChat. *
* If not, see <http://www.gnu.org/licenses/>. *
***************************************************************************/
package net.usikkert.kouchat.net;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Class containing utility methods for network operations.
*
* @author Christian Ihle
*/
public class NetworkUtils {
/** The logger. */
private static final Logger LOG = Logger.getLogger(NetworkUtils.class.getName());
/**
* Checks if the network interface is up, and usable.
*
* <p>A network interface is usable when it:</p>
*
* <ul>
* <li>Is up.</li>
* <li>Supports multicast.</li>
* <li>Is not a loopback device, like localhost.</li>
* <li>Is not a point to point device, like a modem.</li>
* <li>Is not virtual, like <code>eth0:1</code>.</li>
* <li>Is not a virtual machine network interface (vmnet).</li>
* <li>Has an IPv4 address.</li>
* </ul>
*
* @param netif The network interface to check.
* @return True if the network interface is usable.
*/
public boolean isUsable(final NetworkInterface netif) {
if (netif == null) {
return false;
}
try {
return netif.isUp() && !netif.isLoopback() && !netif.isPointToPoint() &&
!netif.isVirtual() && netif.supportsMulticast() &&
!netif.getName().toLowerCase().contains("vmnet") &&
!netif.getDisplayName().toLowerCase().contains("vmnet") &&
hasIPv4Address(netif);
}
catch (final SocketException e) {
LOG.log(Level.WARNING, e.toString());
return false;
}
}
/**
* Checks if the network interface has an IPv4-address.
*
* @param netif The network interface to check.
* @return If an IPv4-address was found or not.
*/
public boolean hasIPv4Address(final NetworkInterface netif) {
if (netif == null) {
return false;
}
final Enumeration<InetAddress> inetAddresses = netif.getInetAddresses();
while (inetAddresses.hasMoreElements()) {
final InetAddress inetAddress = inetAddresses.nextElement();
if (inetAddress instanceof Inet4Address) {
return true;
}
}
return false;
}
/**
* Constructs a string with the information found on a {@link NetworkInterface}.
*
* @param netif The network interface to check.
* @return A string with information.
*/
public String getNetworkInterfaceInfo(final NetworkInterface netif) {
if (netif == null) {
return "Invalid network interface.";
}
try {
return "Interface name: " + netif.getDisplayName() + "\n" +
"Device: " + netif.getName() + "\n" +
"Is loopback: " + netif.isLoopback() + "\n" +
"Is up: " + netif.isUp() + "\n" +
"Is p2p: " + netif.isPointToPoint() + "\n" +
"Is virtual: " + netif.isVirtual() + "\n" +
"Supports multicast: " + netif.supportsMulticast() + "\n" +
"MAC address: " + getMacAddress(netif) + "\n" +
"IP addresses: " + getIPv4Addresses(netif);
}
catch (final SocketException e) {
LOG.log(Level.WARNING, e.toString());
return "Failed to get network interface information.";
}
}
/**
* Returns a list of the IPv4-addresses on the network interface in string format.
*
* @param netif The network interface to get the IPv4-addresses from.
* @return All the IPv4-addresses on the network interface.
*/
public String getIPv4Addresses(final NetworkInterface netif) {
if (netif == null) {
return "";
}
String ipAddress = "";
final Enumeration<InetAddress> inetAddresses = netif.getInetAddresses();
while (inetAddresses.hasMoreElements()) {
final InetAddress inetAddress = inetAddresses.nextElement();
if (inetAddress instanceof Inet4Address) {
ipAddress += inetAddress.getHostAddress() + " ";
}
}
return ipAddress;
}
/**
* Returns a list of the IPv4-addresses on the network interface in string format.
*
* @param networkInterfaceInfo The network interface to get the IPv4-addresses from.
* @return All the IPv4-addresses on the network interface.
*/
public String getIPv4Addresses(final NetworkInterfaceInfo networkInterfaceInfo) {
if (networkInterfaceInfo == null) {
return "";
}
return getIPv4Addresses(networkInterfaceInfo.getNetworkInterface());
}
/**
* Returns the MAC-address of the network interface, in hex format.
*
* @param netif The network interface to get the MAC-address of.
* @return The MAC-address in hex, as a string.
*/
public String getMacAddress(final NetworkInterface netif) {
if (netif == null) {
return "";
}
String macAddress = "";
byte[] address = null;
try {
address = netif.getHardwareAddress();
}
catch (final SocketException e) {
LOG.log(Level.WARNING, e.toString());
}
if (address != null) {
// Convert byte array to hex format
for (int i = 0; i < address.length; i++) {
macAddress += String.format("%02x", address[i]);
if (i != address.length - 1) {
macAddress += "-";
}
}
}
return macAddress.toUpperCase();
}
/**
* Fetches all the network interfaces again, and returns the one
* which is the same as the original network interface.
*
* <p>This is useful to make sure the network interface information
* is up to date, like the current ip address.</p>
*
* @param origNetIf The original network interface to compare with.
* @return An updated version of the same network interface,
* or <code>null</code> if not found.
*/
public NetworkInterface getUpdatedNetworkInterface(final NetworkInterface origNetIf) {
if (origNetIf == null) {
return null;
}
final Enumeration<NetworkInterface> networkInterfaces = getNetworkInterfaces();
if (networkInterfaces == null) {
return null;
}
while (networkInterfaces.hasMoreElements()) {
final NetworkInterface netif = networkInterfaces.nextElement();
if (sameNetworkInterface(origNetIf, netif)) {
return netif;
}
}
return null;
}
/**
* Compares 2 network interfaces. The only way the 2 network interfaces
* can be considered the same is if they have the exact same name.
*
* <p>If any of the network interfaces are <code>null</code> then they
* are not considered the same.</p>
*
* @param netIf1 The first network interface.
* @param netIf2 The second network interface.
* @return If they are the same or not.
*/
public boolean sameNetworkInterface(final NetworkInterface netIf1, final NetworkInterface netIf2) {
if (netIf1 == null || netIf2 == null) {
return false;
}
return netIf1.getName().equals(netIf2.getName());
}
/**
* Iterates through a list of available network interfaces, and returns
* the first that is usable. Returns <code>null</code> if no usable
* interface is found.
*
* @return The first usable network interface, or <code>null</code>.
* @see #isUsable(NetworkInterface)
*/
public NetworkInterface findFirstUsableNetworkInterface() {
final Enumeration<NetworkInterface> networkInterfaces = getNetworkInterfaces();
if (networkInterfaces == null) {
return null;
}
while (networkInterfaces.hasMoreElements()) {
final NetworkInterface netif = networkInterfaces.nextElement();
if (isUsable(netif)) {
return netif;
}
}
return null;
}
/**
* Gets all the available network interfaces. Returns <code>null</code>
* if the operation fails, or no interfaces are available.
*
* @return All network interfaces, or <code>null</code>.
*/
public Enumeration<NetworkInterface> getNetworkInterfaces() {
Enumeration<NetworkInterface> networkInterfaces = null;
try {
networkInterfaces = NetworkInterface.getNetworkInterfaces();
}
catch (final SocketException e) {
LOG.log(Level.WARNING, e.toString());
}
return networkInterfaces;
}
/**
* Iterates through a list of available network interfaces, and returns all that are usable.
*
* @return All the usable network interfaces.
* @see #isUsable(NetworkInterface)
*/
public List<NetworkInterfaceInfo> getUsableNetworkInterfaces() {
final List<NetworkInterfaceInfo> usableNetworkInterfaces = new ArrayList<NetworkInterfaceInfo>();
final Enumeration<NetworkInterface> allNetworkInterfaces = getNetworkInterfaces();
if (allNetworkInterfaces == null) {
return usableNetworkInterfaces;
}
while (allNetworkInterfaces.hasMoreElements()) {
final NetworkInterface netif = allNetworkInterfaces.nextElement();
if (isUsable(netif)) {
usableNetworkInterfaces.add(new NetworkInterfaceInfo(netif));
}
}
return usableNetworkInterfaces;
}
/**
* Gets the name of the localhost.
*
* @return The host name, or <code>null</code> if the host name cannot be determined.
*/
public String getLocalHostName() {
try {
return InetAddress.getLocalHost().getHostName();
}
catch (final UnknownHostException e) {
LOG.log(Level.WARNING, e.toString());
}
return null;
}
/**
* Gets the network interfaces with the requested name. Returns <code>null</code> if no
* interface is found with that name.
*
* @param name Name of the network interface to return.
* @return The requested network interface, or <code>null</code>.
*/
public NetworkInterface getNetworkInterfaceByName(final String name) {
if (name == null) {
return null;
}
try {
return NetworkInterface.getByName(name);
}
catch (final SocketException e) {
LOG.log(Level.WARNING, e.toString());
return null;
}
}
}