Source code

001/**
002 *
003 * Copyright 2003-2006 Jive Software.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smackx.jingleold.nat;
018
019import java.io.IOException;
020import java.net.InetAddress;
021import java.net.NetworkInterface;
022import java.net.SocketException;
023import java.net.URL;
024import java.util.ArrayList;
025import java.util.Enumeration;
026import java.util.logging.Level;
027import java.util.logging.Logger;
028
029import org.jivesoftware.smack.SmackException.NotConnectedException;
030import org.jivesoftware.smack.XMPPException;
031import org.jivesoftware.smack.util.PacketParserUtils;
032import org.jivesoftware.smack.xml.XmlPullParser;
033import org.jivesoftware.smack.xml.XmlPullParserException;
034
035import org.jivesoftware.smackx.jingleold.JingleSession;
036
037import de.javawi.jstun.test.BindingLifetimeTest;
038import de.javawi.jstun.test.DiscoveryInfo;
039import de.javawi.jstun.test.DiscoveryTest;
040
041/**
042 * Transport resolver using the JSTUN library, to discover public IP and use it as a candidate.
043 *
044 * 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.
045 *
046 * @author Thiago Camargo
047 */
048public class STUNResolver extends TransportResolver {
049
050    private static final Logger LOGGER = Logger.getLogger(STUNResolver.class.getName());
051
052    // The filename where the STUN servers are stored.
053    public static final String STUNSERVERS_FILENAME = "META-INF/stun-config.xml";
054
055    // Current STUN server we are using
056    protected STUNService currentServer;
057
058    protected Thread resolverThread;
059
060    protected int defaultPort;
061
062    protected String resolvedPublicIP;
063    protected String resolvedLocalIP;
064
065    /**
066     * Constructor with default STUN server.
067     */
068    public STUNResolver() {
069        super();
070
071        this.defaultPort = 0;
072        this.currentServer = new STUNService();
073    }
074
075    /**
076     * Constructor with a default port.
077     *
078     * @param defaultPort Port to use by default.
079     */
080    public STUNResolver(int defaultPort) {
081        this();
082
083        this.defaultPort = defaultPort;
084    }
085
086    /**
087     * Return true if the service is working.
088     *
089     * @see TransportResolver#isResolving()
090     */
091    @Override
092    public boolean isResolving() {
093        return super.isResolving() && resolverThread != null;
094    }
095
096    /**
097     * Set the STUN server name and port.
098     *
099     * @param ip   the STUN server name
100     * @param port the STUN server port
101     */
102    public void setSTUNService(String ip, int port) {
103        currentServer = new STUNService(ip, port);
104    }
105
106    /**
107     * Get the name of the current STUN server.
108     *
109     * @return the name of the STUN server
110     */
111    public String getCurrentServerName() {
112        if (!currentServer.isNull()) {
113            return currentServer.getHostname();
114        } else {
115            return null;
116        }
117    }
118
119    /**
120     * Get the port of the current STUN server.
121     *
122     * @return the port of the STUN server
123     */
124    public int getCurrentServerPort() {
125        if (!currentServer.isNull()) {
126            return currentServer.getPort();
127        } else {
128            return 0;
129        }
130    }
131
132    /**
133     * Load the STUN configuration from a stream.
134     *
135     * @param stunConfigStream An InputStream with the configuration file.
136     * @return A list of loaded servers
137     */
138    public ArrayList<STUNService> loadSTUNServers(java.io.InputStream stunConfigStream) {
139        ArrayList<STUNService> serversList = new ArrayList<>();
140        String serverName;
141        int serverPort;
142
143        try {
144            XmlPullParser parser = PacketParserUtils.getParserFor(stunConfigStream);
145
146            XmlPullParser.Event eventType = parser.getEventType();
147            do {
148                if (eventType == XmlPullParser.Event.START_ELEMENT) {
149
150                    // Parse a STUN server definition
151                    if (parser.getName().equals("stunServer")) {
152
153                        serverName = null;
154                        serverPort = -1;
155
156                        // Parse the hostname
157                        parser.next();
158                        parser.next();
159                        serverName = parser.nextText();
160
161                        // Parse the port
162                        parser.next();
163                        parser.next();
164                        serverPort = Integer.parseInt(parser.nextText());
165
166                        // If we have a valid hostname and port, add
167                        // it to the list.
168                        if (serverName != null && serverPort != -1) {
169                            STUNService service = new STUNService(serverName, serverPort);
170
171                            serversList.add(service);
172                        }
173                    }
174                }
175                eventType = parser.next();
176
177            }
178            while (eventType != XmlPullParser.Event.END_DOCUMENT);
179
180        }
181        catch (XmlPullParserException e) {
182            LOGGER.log(Level.SEVERE, "Exception", e);
183        }
184        catch (IOException e) {
185            LOGGER.log(Level.SEVERE, "Exception", e);
186        }
187
188        currentServer = bestSTUNServer(serversList);
189
190        return serversList;
191    }
192
193    /**
194     * Load a list of services: STUN servers and ports. Some public STUN servers
195     * are:
196     *
197     * <pre>
198     *               iphone-stun.freenet.de:3478
199     *               larry.gloo.net:3478
200     *               stun.xten.net:3478
201     *               stun.fwdnet.net
202     *               stun.fwd.org (no DNS SRV record)
203     *               stun01.sipphone.com (no DNS SRV record)
204     *               stun.softjoys.com (no DNS SRV record)
205     *               stun.voipbuster.com (no DNS SRV record)
206     *               stun.voxgratia.org (no DNS SRV record)
207     *               stun.noc.ams-ix.net
208     * </pre>
209     *
210     * This list should be contained in a file in the "META-INF" directory
211     *
212     * @return a list of services
213     */
214    public ArrayList<STUNService> loadSTUNServers() {
215        ArrayList<STUNService> serversList = new ArrayList<>();
216
217        // Load the STUN configuration
218        try {
219            // Get an array of class loaders to try loading the config from.
220            ClassLoader[] classLoaders = new ClassLoader[2];
221            classLoaders[0] = new STUNResolver() {
222            }.getClass().getClassLoader();
223            classLoaders[1] = Thread.currentThread().getContextClassLoader();
224
225            for (int i = 0; i < classLoaders.length; i++) {
226                Enumeration<URL> stunConfigEnum = classLoaders[i]
227                        .getResources(STUNSERVERS_FILENAME);
228
229                while (stunConfigEnum.hasMoreElements() && serversList.isEmpty()) {
230                    URL url = stunConfigEnum.nextElement();
231                    java.io.InputStream stunConfigStream;
232
233                    stunConfigStream = url.openStream();
234                    serversList.addAll(loadSTUNServers(stunConfigStream));
235                    stunConfigStream.close();
236                }
237            }
238        }
239        catch (Exception e) {
240            LOGGER.log(Level.SEVERE, "Exception", e);
241        }
242
243        return serversList;
244    }
245
246    /**
247     * Get the best usable STUN server from a list.
248     *
249     * @return the best STUN server that can be used.
250     */
251    private static STUNService bestSTUNServer(ArrayList<STUNService> listServers) {
252        if (listServers.isEmpty()) {
253            return null;
254        } else {
255            // TODO: this should use some more advanced criteria...
256            return listServers.get(0);
257        }
258    }
259
260    /**
261     * Resolve the IP and obtain a valid transport method.
262     * @throws NotConnectedException if the XMPP connection is not connected.
263     * @throws InterruptedException if the calling thread was interrupted.
264     */
265    @Override
266    public synchronized void resolve(JingleSession session) throws XMPPException, NotConnectedException, InterruptedException {
267
268        setResolveInit();
269
270        clearCandidates();
271
272        TransportCandidate candidate = new TransportCandidate.Fixed(
273                resolvedPublicIP, getFreePort());
274        candidate.setLocalIp(resolvedLocalIP);
275
276        LOGGER.fine("RESOLVING : " + resolvedPublicIP + ":" + candidate.getPort());
277
278        addCandidate(candidate);
279
280        setResolveEnd();
281
282    }
283
284    /**
285     * Initialize the resolver.
286     *
287     * @throws XMPPException if an XMPP protocol error was received.
288     */
289    @Override
290    public void initialize() throws XMPPException {
291        LOGGER.fine("Initialized");
292        if (!isResolving() && !isResolved()) {
293            // Get the best STUN server available
294            if (currentServer.isNull()) {
295                loadSTUNServers();
296            }
297            // We should have a valid STUN server by now...
298            if (!currentServer.isNull()) {
299
300                clearCandidates();
301
302                resolverThread = new Thread(new Runnable() {
303                    @Override
304                    public void run() {
305                        // Iterate through the list of interfaces, and ask
306                        // to the STUN server for our address.
307                        try {
308                            Enumeration<NetworkInterface> ifaces = NetworkInterface.getNetworkInterfaces();
309                            String candAddress;
310                            int candPort;
311
312                            while (ifaces.hasMoreElements()) {
313
314                                NetworkInterface iface =  ifaces.nextElement();
315                                Enumeration<InetAddress> iaddresses = iface.getInetAddresses();
316
317                                while (iaddresses.hasMoreElements()) {
318                                    InetAddress iaddress = iaddresses.nextElement();
319                                    if (!iaddress.isLoopbackAddress()
320                                            && !iaddress.isLinkLocalAddress()) {
321
322                                        // Reset the candidate
323                                        candAddress = null;
324                                        candPort = -1;
325
326                                        DiscoveryTest test = new DiscoveryTest(iaddress,
327                                                currentServer.getHostname(),
328                                                currentServer.getPort());
329                                        try {
330                                            // Run the tests and get the
331                                            // discovery
332                                            // information, where all the
333                                            // info is stored...
334                                            DiscoveryInfo di = test.test();
335
336                                            candAddress = di.getPublicIP() != null ?
337                                                    di.getPublicIP().getHostAddress() : null;
338
339                                            // Get a valid port
340                                            if (defaultPort == 0) {
341                                                candPort = getFreePort();
342                                            } else {
343                                                candPort = defaultPort;
344                                            }
345
346                                            // If we have a valid candidate,
347                                            // add it to the list.
348                                            if (candAddress != null && candPort >= 0) {
349                                                TransportCandidate candidate = new TransportCandidate.Fixed(
350                                                        candAddress, candPort);
351                                                candidate.setLocalIp(iaddress.getHostAddress() != null ? iaddress.getHostAddress() : iaddress.getHostName());
352                                                addCandidate(candidate);
353
354                                                resolvedPublicIP = candidate.getIp();
355                                                resolvedLocalIP = candidate.getLocalIp();
356                                                return;
357                                            }
358                                        }
359                                        catch (Exception e) {
360                                            LOGGER.log(Level.SEVERE, "Exception", e);
361                                        }
362                                    }
363                                }
364                            }
365                        }
366                        catch (SocketException e) {
367                            LOGGER.log(Level.SEVERE, "Exception", e);
368                        }
369                        finally {
370                            setInitialized();
371                        }
372                    }
373                }, "Waiting for all the transport candidates checks...");
374
375                resolverThread.setName("STUN resolver");
376                resolverThread.start();
377            } else {
378                throw new IllegalStateException("No valid STUN server found.");
379            }
380        }
381    }
382
383    /**
384     * Cancel any operation.
385     *
386     * @see TransportResolver#cancel()
387     */
388    @Override
389    public synchronized void cancel() throws XMPPException {
390        if (isResolving()) {
391            resolverThread.interrupt();
392            setResolveEnd();
393        }
394    }
395
396    /**
397     * Clear the list of candidates and start the resolution again.
398     *
399     * @see TransportResolver#clear()
400     */
401    @Override
402    public synchronized void clear() throws XMPPException {
403        this.defaultPort = 0;
404        super.clear();
405    }
406
407    /**
408     * STUN service definition.
409     */
410    protected static class STUNService {
411
412        private String hostname; // The hostname of the service
413
414        private int port; // The port number
415
416        /**
417         * Basic constructor, with the hostname and port
418         *
419         * @param hostname The hostname
420         * @param port     The port
421         */
422        public STUNService(String hostname, int port) {
423            super();
424
425            this.hostname = hostname;
426            this.port = port;
427        }
428
429        /**
430         * Default constructor, without name and port.
431         */
432        public STUNService() {
433            this(null, -1);
434        }
435
436        /**
437         * Get the host name of the STUN service.
438         *
439         * @return The host name
440         */
441        public String getHostname() {
442            return hostname;
443        }
444
445        /**
446         * Set the hostname of the STUN service.
447         *
448         * @param hostname The host name of the service.
449         */
450        public void setHostname(String hostname) {
451            this.hostname = hostname;
452        }
453
454        /**
455         * Get the port of the STUN service
456         *
457         * @return The port number where the STUN server is waiting.
458         */
459        public int getPort() {
460            return port;
461        }
462
463        /**
464         * Set the port number for the STUN service.
465         *
466         * @param port The port number.
467         */
468        public void setPort(int port) {
469            this.port = port;
470        }
471
472        /**
473         * Basic format test: the service is not null.
474         *
475         * @return true if the hostname and port are null
476         */
477        public boolean isNull() {
478            if (hostname == null) {
479                return true;
480            } else if (hostname.length() == 0) {
481                return true;
482            } else if (port < 0) {
483                return true;
484            } else {
485                return false;
486            }
487        }
488
489        /**
490         * Check a binding with the STUN currentServer.
491         *
492         * Note: this function blocks for some time, waiting for a response.
493         *
494         * @return true if the currentServer is usable.
495         */
496        public boolean checkBinding() {
497            boolean result = false;
498
499            try {
500                BindingLifetimeTest binding = new BindingLifetimeTest(hostname, port);
501
502                binding.test();
503
504                while (true) {
505                    Thread.sleep(5000);
506                    if (binding.getLifetime() != -1) {
507                        if (binding.isCompleted()) {
508                            return true;
509                        }
510                    } else {
511                        break;
512                    }
513                }
514            }
515            catch (Exception e) {
516                LOGGER.log(Level.SEVERE, "Exception in checkBinding", e);
517            }
518
519            return result;
520        }
521    }
522}