Shuyi Chen | d7955ce | 2013-05-22 14:51:55 -0700 | [diff] [blame] | 1 | /** |
| 2 | * Copyright 2012-2013 Florian Schmaus |
| 3 | * |
| 4 | * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.jivesoftware.smackx.ping; |
| 18 | |
| 19 | import java.util.Collections; |
| 20 | import java.util.HashSet; |
| 21 | import java.util.Map; |
| 22 | import java.util.Set; |
| 23 | import java.util.WeakHashMap; |
| 24 | import java.util.concurrent.ScheduledExecutorService; |
| 25 | import java.util.concurrent.ScheduledFuture; |
| 26 | import java.util.concurrent.ScheduledThreadPoolExecutor; |
| 27 | import java.util.concurrent.TimeUnit; |
| 28 | |
| 29 | import org.jivesoftware.smack.Connection; |
| 30 | import org.jivesoftware.smack.ConnectionCreationListener; |
| 31 | import org.jivesoftware.smack.ConnectionListener; |
| 32 | import org.jivesoftware.smack.PacketCollector; |
| 33 | import org.jivesoftware.smack.PacketListener; |
| 34 | import org.jivesoftware.smack.SmackConfiguration; |
| 35 | import org.jivesoftware.smack.XMPPException; |
| 36 | import org.jivesoftware.smack.filter.PacketFilter; |
| 37 | import org.jivesoftware.smack.filter.PacketIDFilter; |
| 38 | import org.jivesoftware.smack.filter.PacketTypeFilter; |
| 39 | import org.jivesoftware.smack.packet.IQ; |
| 40 | import org.jivesoftware.smack.packet.Packet; |
| 41 | import org.jivesoftware.smackx.ServiceDiscoveryManager; |
| 42 | import org.jivesoftware.smackx.packet.DiscoverInfo; |
| 43 | import org.jivesoftware.smackx.ping.packet.Ping; |
| 44 | import org.jivesoftware.smackx.ping.packet.Pong; |
| 45 | |
| 46 | /** |
| 47 | * Implements the XMPP Ping as defined by XEP-0199. This protocol offers an |
| 48 | * alternative to the traditional 'white space ping' approach of determining the |
| 49 | * availability of an entity. The XMPP Ping protocol allows ping messages to be |
| 50 | * send in a more XML-friendly approach, which can be used over more than one |
| 51 | * hop in the communication path. |
| 52 | * |
| 53 | * @author Florian Schmaus |
| 54 | * @see <a href="http://www.xmpp.org/extensions/xep-0199.html">XEP-0199:XMPP |
| 55 | * Ping</a> |
| 56 | */ |
| 57 | public class PingManager { |
| 58 | |
| 59 | public static final String NAMESPACE = "urn:xmpp:ping"; |
| 60 | public static final String ELEMENT = "ping"; |
| 61 | |
| 62 | |
| 63 | private static Map<Connection, PingManager> instances = |
| 64 | Collections.synchronizedMap(new WeakHashMap<Connection, PingManager>()); |
| 65 | |
| 66 | static { |
| 67 | Connection.addConnectionCreationListener(new ConnectionCreationListener() { |
| 68 | public void connectionCreated(Connection connection) { |
| 69 | new PingManager(connection); |
| 70 | } |
| 71 | }); |
| 72 | } |
| 73 | |
| 74 | private ScheduledExecutorService periodicPingExecutorService; |
| 75 | private Connection connection; |
| 76 | private int pingInterval = SmackConfiguration.getDefaultPingInterval(); |
| 77 | private Set<PingFailedListener> pingFailedListeners = Collections |
| 78 | .synchronizedSet(new HashSet<PingFailedListener>()); |
| 79 | private ScheduledFuture<?> periodicPingTask; |
| 80 | protected volatile long lastSuccessfulPingByTask = -1; |
| 81 | |
| 82 | |
| 83 | // Ping Flood protection |
| 84 | private long pingMinDelta = 100; |
| 85 | private long lastPingStamp = 0; // timestamp of the last received ping |
| 86 | |
| 87 | // Timestamp of the last pong received, either from the server or another entity |
| 88 | // Note, no need to synchronize this value, it will only increase over time |
| 89 | private long lastSuccessfulManualPing = -1; |
| 90 | |
| 91 | private PingManager(Connection connection) { |
| 92 | ServiceDiscoveryManager sdm = ServiceDiscoveryManager.getInstanceFor(connection); |
| 93 | sdm.addFeature(NAMESPACE); |
| 94 | this.connection = connection; |
| 95 | init(); |
| 96 | } |
| 97 | |
| 98 | private void init() { |
| 99 | periodicPingExecutorService = new ScheduledThreadPoolExecutor(1); |
| 100 | PacketFilter pingPacketFilter = new PacketTypeFilter(Ping.class); |
| 101 | connection.addPacketListener(new PacketListener() { |
| 102 | /** |
| 103 | * Sends a Pong for every Ping |
| 104 | */ |
| 105 | public void processPacket(Packet packet) { |
| 106 | if (pingMinDelta > 0) { |
| 107 | // Ping flood protection enabled |
| 108 | long currentMillies = System.currentTimeMillis(); |
| 109 | long delta = currentMillies - lastPingStamp; |
| 110 | lastPingStamp = currentMillies; |
| 111 | if (delta < pingMinDelta) { |
| 112 | return; |
| 113 | } |
| 114 | } |
| 115 | Pong pong = new Pong((Ping)packet); |
| 116 | connection.sendPacket(pong); |
| 117 | } |
| 118 | } |
| 119 | , pingPacketFilter); |
| 120 | connection.addConnectionListener(new ConnectionListener() { |
| 121 | |
| 122 | @Override |
| 123 | public void connectionClosed() { |
| 124 | maybeStopPingServerTask(); |
| 125 | } |
| 126 | |
| 127 | @Override |
| 128 | public void connectionClosedOnError(Exception arg0) { |
| 129 | maybeStopPingServerTask(); |
| 130 | } |
| 131 | |
| 132 | @Override |
| 133 | public void reconnectionSuccessful() { |
| 134 | maybeSchedulePingServerTask(); |
| 135 | } |
| 136 | |
| 137 | @Override |
| 138 | public void reconnectingIn(int seconds) { |
| 139 | } |
| 140 | |
| 141 | @Override |
| 142 | public void reconnectionFailed(Exception e) { |
| 143 | } |
| 144 | }); |
| 145 | instances.put(connection, this); |
| 146 | maybeSchedulePingServerTask(); |
| 147 | } |
| 148 | |
| 149 | public static PingManager getInstanceFor(Connection connection) { |
| 150 | PingManager pingManager = instances.get(connection); |
| 151 | |
| 152 | if (pingManager == null) { |
| 153 | pingManager = new PingManager(connection); |
| 154 | } |
| 155 | |
| 156 | return pingManager; |
| 157 | } |
| 158 | |
| 159 | public void setPingIntervall(int pingIntervall) { |
| 160 | this.pingInterval = pingIntervall; |
| 161 | } |
| 162 | |
| 163 | public int getPingIntervall() { |
| 164 | return pingInterval; |
| 165 | } |
| 166 | |
| 167 | public void registerPingFailedListener(PingFailedListener listener) { |
| 168 | pingFailedListeners.add(listener); |
| 169 | } |
| 170 | |
| 171 | public void unregisterPingFailedListener(PingFailedListener listener) { |
| 172 | pingFailedListeners.remove(listener); |
| 173 | } |
| 174 | |
| 175 | public void disablePingFloodProtection() { |
| 176 | setPingMinimumInterval(-1); |
| 177 | } |
| 178 | |
| 179 | public void setPingMinimumInterval(long ms) { |
| 180 | this.pingMinDelta = ms; |
| 181 | } |
| 182 | |
| 183 | public long getPingMinimumInterval() { |
| 184 | return this.pingMinDelta; |
| 185 | } |
| 186 | |
| 187 | /** |
| 188 | * Pings the given jid and returns the IQ response which is either of |
| 189 | * IQ.Type.ERROR or IQ.Type.RESULT. If we are not connected or if there was |
| 190 | * no reply, null is returned. |
| 191 | * |
| 192 | * You should use isPingSupported(jid) to determine if XMPP Ping is |
| 193 | * supported by the user. |
| 194 | * |
| 195 | * @param jid |
| 196 | * @param pingTimeout |
| 197 | * @return |
| 198 | */ |
| 199 | public IQ ping(String jid, long pingTimeout) { |
| 200 | // Make sure we actually connected to the server |
| 201 | if (!connection.isAuthenticated()) |
| 202 | return null; |
| 203 | |
| 204 | Ping ping = new Ping(connection.getUser(), jid); |
| 205 | |
| 206 | PacketCollector collector = |
| 207 | connection.createPacketCollector(new PacketIDFilter(ping.getPacketID())); |
| 208 | |
| 209 | connection.sendPacket(ping); |
| 210 | |
| 211 | IQ result = (IQ) collector.nextResult(pingTimeout); |
| 212 | |
| 213 | collector.cancel(); |
| 214 | return result; |
| 215 | } |
| 216 | |
| 217 | /** |
| 218 | * Pings the given jid and returns the IQ response with the default |
| 219 | * packet reply timeout |
| 220 | * |
| 221 | * @param jid |
| 222 | * @return |
| 223 | */ |
| 224 | public IQ ping(String jid) { |
| 225 | return ping(jid, SmackConfiguration.getPacketReplyTimeout()); |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Pings the given Entity. |
| 230 | * |
| 231 | * Note that XEP-199 shows that if we receive a error response |
| 232 | * service-unavailable there is no way to determine if the response was send |
| 233 | * by the entity (e.g. a user JID) or from a server in between. This is |
| 234 | * intended behavior to avoid presence leaks. |
| 235 | * |
| 236 | * Always use isPingSupported(jid) to determine if XMPP Ping is supported |
| 237 | * by the entity. |
| 238 | * |
| 239 | * @param jid |
| 240 | * @return True if a pong was received, otherwise false |
| 241 | */ |
| 242 | public boolean pingEntity(String jid, long pingTimeout) { |
| 243 | IQ result = ping(jid, pingTimeout); |
| 244 | |
| 245 | if (result == null || result.getType() == IQ.Type.ERROR) { |
| 246 | return false; |
| 247 | } |
| 248 | pongReceived(); |
| 249 | return true; |
| 250 | } |
| 251 | |
| 252 | public boolean pingEntity(String jid) { |
| 253 | return pingEntity(jid, SmackConfiguration.getPacketReplyTimeout()); |
| 254 | } |
| 255 | |
| 256 | /** |
| 257 | * Pings the user's server. Will notify the registered |
| 258 | * pingFailedListeners in case of error. |
| 259 | * |
| 260 | * If we receive as response, we can be sure that it came from the server. |
| 261 | * |
| 262 | * @return true if successful, otherwise false |
| 263 | */ |
| 264 | public boolean pingMyServer(long pingTimeout) { |
| 265 | IQ result = ping(connection.getServiceName(), pingTimeout); |
| 266 | |
| 267 | if (result == null) { |
| 268 | for (PingFailedListener l : pingFailedListeners) { |
| 269 | l.pingFailed(); |
| 270 | } |
| 271 | return false; |
| 272 | } |
| 273 | // Maybe not really a pong, but an answer is an answer |
| 274 | pongReceived(); |
| 275 | return true; |
| 276 | } |
| 277 | |
| 278 | /** |
| 279 | * Pings the user's server with the PacketReplyTimeout as defined |
| 280 | * in SmackConfiguration. |
| 281 | * |
| 282 | * @return true if successful, otherwise false |
| 283 | */ |
| 284 | public boolean pingMyServer() { |
| 285 | return pingMyServer(SmackConfiguration.getPacketReplyTimeout()); |
| 286 | } |
| 287 | |
| 288 | /** |
| 289 | * Returns true if XMPP Ping is supported by a given JID |
| 290 | * |
| 291 | * @param jid |
| 292 | * @return |
| 293 | */ |
| 294 | public boolean isPingSupported(String jid) { |
| 295 | try { |
| 296 | DiscoverInfo result = |
| 297 | ServiceDiscoveryManager.getInstanceFor(connection).discoverInfo(jid); |
| 298 | return result.containsFeature(NAMESPACE); |
| 299 | } |
| 300 | catch (XMPPException e) { |
| 301 | return false; |
| 302 | } |
| 303 | } |
| 304 | |
| 305 | /** |
| 306 | * Returns the time of the last successful Ping Pong with the |
| 307 | * users server. If there was no successful Ping (e.g. because this |
| 308 | * feature is disabled) -1 will be returned. |
| 309 | * |
| 310 | * @return |
| 311 | */ |
| 312 | public long getLastSuccessfulPing() { |
| 313 | return Math.max(lastSuccessfulPingByTask, lastSuccessfulManualPing); |
| 314 | } |
| 315 | |
| 316 | protected Set<PingFailedListener> getPingFailedListeners() { |
| 317 | return pingFailedListeners; |
| 318 | } |
| 319 | |
| 320 | /** |
| 321 | * Cancels any existing periodic ping task if there is one and schedules a new ping task if pingInterval is greater |
| 322 | * then zero. |
| 323 | * |
| 324 | */ |
| 325 | protected synchronized void maybeSchedulePingServerTask() { |
| 326 | maybeStopPingServerTask(); |
| 327 | if (pingInterval > 0) { |
| 328 | periodicPingTask = periodicPingExecutorService.schedule(new ServerPingTask(connection), pingInterval, |
| 329 | TimeUnit.SECONDS); |
| 330 | } |
| 331 | } |
| 332 | |
| 333 | private void maybeStopPingServerTask() { |
| 334 | if (periodicPingTask != null) { |
| 335 | periodicPingTask.cancel(true); |
| 336 | periodicPingTask = null; |
| 337 | } |
| 338 | } |
| 339 | |
| 340 | private void pongReceived() { |
| 341 | lastSuccessfulManualPing = System.currentTimeMillis(); |
| 342 | } |
| 343 | } |