/**
* $RCSfile: STUNResolver.java,v $
* $Revision: 1.1 $
* $Date: 15/11/2006
*
* Copyright 2003-2006 Jive Software.
*
* All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jivesoftware.smackx.jingle.nat;
import java.io.IOException;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Enumeration;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smackx.jingle.JingleSession;
import org.jivesoftware.smackx.jingle.SmackLogger;
import org.xmlpull.mxp1.MXParser;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import de.javawi.jstun.test.BindingLifetimeTest;
import de.javawi.jstun.test.DiscoveryInfo;
import de.javawi.jstun.test.DiscoveryTest;
/**
* Transport resolver using the JSTUN library, to discover public IP and use it as a candidate.
*
* The goal of this resolver is to take possible to establish and manage out-of-band connections between two XMPP entities, even if they are behind Network Address Translators (NATs) or firewalls.
*
* @author Thiago Camargo
*/
public class STUNResolver extends TransportResolver {
private static final SmackLogger LOGGER = SmackLogger.getLogger(STUNResolver.class);
// The filename where the STUN servers are stored.
public final static String STUNSERVERS_FILENAME = "META-INF/stun-config.xml";
// Current STUN server we are using
protected STUNService currentServer;
protected Thread resolverThread;
protected int defaultPort;
protected String resolvedPublicIP;
protected String resolvedLocalIP;
/**
* Constructor with default STUN server.
*/
public STUNResolver() {
super();
this.defaultPort = 0;
this.currentServer = new STUNService();
}
/**
* Constructor with a default port.
*
* @param defaultPort Port to use by default.
*/
public STUNResolver(int defaultPort) {
this();
this.defaultPort = defaultPort;
}
/**
* Return true if the service is working.
*
* @see TransportResolver#isResolving()
*/
public boolean isResolving() {
return super.isResolving() && resolverThread != null;
}
/**
* Set the STUN server name and port
*
* @param ip the STUN server name
* @param port the STUN server port
*/
public void setSTUNService(String ip, int port) {
currentServer = new STUNService(ip, port);
}
/**
* Get the name of the current STUN server.
*
* @return the name of the STUN server
*/
public String getCurrentServerName() {
if (!currentServer.isNull()) {
return currentServer.getHostname();
} else {
return null;
}
}
/**
* Get the port of the current STUN server.
*
* @return the port of the STUN server
*/
public int getCurrentServerPort() {
if (!currentServer.isNull()) {
return currentServer.getPort();
} else {
return 0;
}
}
/**
* Load the STUN configuration from a stream.
*
* @param stunConfigStream An InputStream with the configuration file.
* @return A list of loaded servers
*/
public ArrayList<STUNService> loadSTUNServers(java.io.InputStream stunConfigStream) {
ArrayList<STUNService> serversList = new ArrayList<STUNService>();
String serverName;
int serverPort;
try {
XmlPullParser parser = new MXParser();
parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, true);
parser.setInput(stunConfigStream, "UTF-8");
int eventType = parser.getEventType();
do {
if (eventType == XmlPullParser.START_TAG) {
// Parse a STUN server definition
if (parser.getName().equals("stunServer")) {
serverName = null;
serverPort = -1;
// Parse the hostname
parser.next();
parser.next();
serverName = parser.nextText();
// Parse the port
parser.next();
parser.next();
try {
serverPort = Integer.parseInt(parser.nextText());
}
catch (Exception e) {
}
// If we have a valid hostname and port, add
// it to the list.
if (serverName != null && serverPort != -1) {
STUNService service = new STUNService(serverName, serverPort);
serversList.add(service);
}
}
}
eventType = parser.next();
}
while (eventType != XmlPullParser.END_DOCUMENT);
}
catch (XmlPullParserException e) {
LOGGER.error(e.getMessage(), e);
}
catch (IOException e) {
LOGGER.error(e.getMessage(), e);
}
currentServer = bestSTUNServer(serversList);
return serversList;
}
/**
* Load a list of services: STUN servers and ports. Some public STUN servers
* are:
* <p/>
* <pre>
* iphone-stun.freenet.de:3478
* larry.gloo.net:3478
* stun.xten.net:3478
* stun.fwdnet.net
* stun.fwd.org (no DNS SRV record)
* stun01.sipphone.com (no DNS SRV record)
* stun.softjoys.com (no DNS SRV record)
* stun.voipbuster.com (no DNS SRV record)
* stun.voxgratia.org (no DNS SRV record)
* stun.noc.ams-ix.net
* </pre>
* <p/>
* This list should be contained in a file in the "META-INF" directory
*
* @return a list of services
*/
public ArrayList<STUNService> loadSTUNServers() {
ArrayList<STUNService> serversList = new ArrayList<STUNService>();
// Load the STUN configuration
try {
// Get an array of class loaders to try loading the config from.
ClassLoader[] classLoaders = new ClassLoader[2];
classLoaders[0] = new STUNResolver() {
}.getClass().getClassLoader();
classLoaders[1] = Thread.currentThread().getContextClassLoader();
for (int i = 0; i < classLoaders.length; i++) {
Enumeration<URL> stunConfigEnum = classLoaders[i]
.getResources(STUNSERVERS_FILENAME);
while (stunConfigEnum.hasMoreElements() && serversList.isEmpty()) {
URL url = stunConfigEnum.nextElement();
java.io.InputStream stunConfigStream = null;
stunConfigStream = url.openStream();
serversList.addAll(loadSTUNServers(stunConfigStream));
stunConfigStream.close();
}
}
}
catch (Exception e) {
LOGGER.error(e.getMessage(), e);
}
return serversList;
}
/**
* Get the best usable STUN server from a list.
*
* @return the best STUN server that can be used.
*/
private STUNService bestSTUNServer(ArrayList<STUNService> listServers) {
if (listServers.isEmpty()) {
return null;
} else {
// TODO: this should use some more advanced criteria...
return listServers.get(0);
}
}
/**
* Resolve the IP and obtain a valid transport method.
*/
public synchronized void resolve(JingleSession session) throws XMPPException {
setResolveInit();
clearCandidates();
TransportCandidate candidate = new TransportCandidate.Fixed(
resolvedPublicIP, getFreePort());
candidate.setLocalIp(resolvedLocalIP);
LOGGER.debug("RESOLVING : " + resolvedPublicIP + ":" + candidate.getPort());
addCandidate(candidate);
setResolveEnd();
}
/**
* Initialize the resolver.
*
* @throws XMPPException
*/
public void initialize() throws XMPPException {
LOGGER.debug("Initialized");
if (!isResolving()&&!isResolved()) {
// Get the best STUN server available
if (currentServer.isNull()) {
loadSTUNServers();
}
// We should have a valid STUN server by now...
if (!currentServer.isNull()) {
clearCandidates();
resolverThread = new Thread(new Runnable() {
public void run() {
// Iterate through the list of interfaces, and ask
// to the STUN server for our address.
try {
Enumeration<NetworkInterface> ifaces = NetworkInterface.getNetworkInterfaces();
String candAddress;
int candPort;
while (ifaces.hasMoreElements()) {
NetworkInterface iface = ifaces.nextElement();
Enumeration<InetAddress> iaddresses = iface.getInetAddresses();
while (iaddresses.hasMoreElements()) {
InetAddress iaddress = iaddresses.nextElement();
if (!iaddress.isLoopbackAddress()
&& !iaddress.isLinkLocalAddress()) {
// Reset the candidate
candAddress = null;
candPort = -1;
DiscoveryTest test = new DiscoveryTest(iaddress,
currentServer.getHostname(),
currentServer.getPort());
try {
// Run the tests and get the
// discovery
// information, where all the
// info is stored...
DiscoveryInfo di = test.test();
candAddress = di.getPublicIP() != null ?
di.getPublicIP().getHostAddress() : null;
// Get a valid port
if (defaultPort == 0) {
candPort = getFreePort();
} else {
candPort = defaultPort;
}
// If we have a valid candidate,
// add it to the list.
if (candAddress != null && candPort >= 0) {
TransportCandidate candidate = new TransportCandidate.Fixed(
candAddress, candPort);
candidate.setLocalIp(iaddress.getHostAddress() != null ? iaddress.getHostAddress() : iaddress.getHostName());
addCandidate(candidate);
resolvedPublicIP = candidate.getIp();
resolvedLocalIP = candidate.getLocalIp();
return;
}
}
catch (Exception e) {
LOGGER.error(e.getMessage(), e);
}
}
}
}
}
catch (SocketException e) {
LOGGER.error(e.getMessage(), e);
}
finally {
setInitialized();
}
}
}, "Waiting for all the transport candidates checks...");
resolverThread.setName("STUN resolver");
resolverThread.start();
} else {
throw new IllegalStateException("No valid STUN server found.");
}
}
}
/**
* Cancel any operation.
*
* @see TransportResolver#cancel()
*/
public synchronized void cancel() throws XMPPException {
if (isResolving()) {
resolverThread.interrupt();
setResolveEnd();
}
}
/**
* Clear the list of candidates and start the resolution again.
*
* @see TransportResolver#clear()
*/
public synchronized void clear() throws XMPPException {
this.defaultPort = 0;
super.clear();
}
/**
* STUN service definition.
*/
protected class STUNService {
private String hostname; // The hostname of the service
private int port; // The port number
/**
* Basic constructor, with the hostname and port
*
* @param hostname The hostname
* @param port The port
*/
public STUNService(String hostname, int port) {
super();
this.hostname = hostname;
this.port = port;
}
/**
* Default constructor, without name and port.
*/
public STUNService() {
this(null, -1);
}
/**
* Get the host name of the STUN service.
*
* @return The host name
*/
public String getHostname() {
return hostname;
}
/**
* Set the hostname of the STUN service.
*
* @param hostname The host name of the service.
*/
public void setHostname(String hostname) {
this.hostname = hostname;
}
/**
* Get the port of the STUN service
*
* @return The port number where the STUN server is waiting.
*/
public int getPort() {
return port;
}
/**
* Set the port number for the STUN service.
*
* @param port The port number.
*/
public void setPort(int port) {
this.port = port;
}
/**
* Basic format test: the service is not null.
*
* @return true if the hostname and port are null
*/
public boolean isNull() {
if (hostname == null) {
return true;
} else if (hostname.length() == 0) {
return true;
} else if (port < 0) {
return true;
} else {
return false;
}
}
/**
* Check a binding with the STUN currentServer.
* <p/>
* Note: this function blocks for some time, waiting for a response.
*
* @return true if the currentServer is usable.
*/
public boolean checkBinding() {
boolean result = false;
try {
BindingLifetimeTest binding = new BindingLifetimeTest(hostname, port);
binding.test();
while (true) {
Thread.sleep(5000);
if (binding.getLifetime() != -1) {
if (binding.isCompleted()) {
return true;
}
} else {
break;
}
}
}
catch (Exception e) {
LOGGER.error(e.getMessage(), e);
}
return result;
}
}
}