Java tutorial
/** * Copyright (C) 2015 Tom Evans. 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.openfire.websocket; import java.io.IOException; import java.io.StringReader; import java.util.Locale; import java.util.TimerTask; import org.apache.commons.pool2.impl.GenericObjectPool; import org.dom4j.Document; import org.dom4j.Element; import org.dom4j.QName; import org.dom4j.io.XMPPPacketReader; import org.eclipse.jetty.websocket.api.RemoteEndpoint; import org.eclipse.jetty.websocket.api.Session; import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose; import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect; import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError; import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage; import org.eclipse.jetty.websocket.api.annotations.WebSocket; import org.jivesoftware.openfire.Connection; import org.jivesoftware.openfire.SessionManager; import org.jivesoftware.openfire.SessionPacketRouter; import org.jivesoftware.openfire.XMPPServer; import org.jivesoftware.openfire.multiplex.UnknownStanzaException; import org.jivesoftware.openfire.net.SASLAuthentication; import org.jivesoftware.openfire.net.SASLAuthentication.Status; import org.jivesoftware.openfire.session.ConnectionSettings; import org.jivesoftware.openfire.session.LocalClientSession; import org.jivesoftware.openfire.streammanagement.StreamManager; import org.jivesoftware.util.JiveConstants; import org.jivesoftware.util.JiveGlobals; import org.jivesoftware.util.TaskEngine; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.xmpp.packet.PacketError; import org.xmpp.packet.StreamError; import javax.xml.XMLConstants; /** * This class handles all WebSocket events for the corresponding connection with a remote peer. * Specifically the XMPP session is managed concurrently with the WebSocket session, including all * framing and authentication requirements. Packets received from the remote peer are forwarded as * needed via a {@link SessionPacketRouter}, and packets destined for the remote peer are forwarded * via the corresponding {@link RemoteEndpoint}. */ @WebSocket public class XmppWebSocket { private static final String STREAM_HEADER = "open"; private static final String STREAM_FOOTER = "close"; private static final String FRAMING_NAMESPACE = "urn:ietf:params:xml:ns:xmpp-framing"; private static Logger Log = LoggerFactory.getLogger(XmppWebSocket.class); private static GenericObjectPool<XMPPPacketReader> readerPool; private SessionPacketRouter router; private Session wsSession; private WebSocketConnection wsConnection; private LocalClientSession xmppSession; private boolean startedSASL = false; private Status saslStatus; private TimerTask pingTask; public XmppWebSocket() { if (readerPool == null) { initializePool(); } } // WebSocket event handlers @OnWebSocketConnect public void onConnect(Session session) { wsSession = session; wsConnection = new WebSocketConnection(this, session.getRemoteAddress()); pingTask = new PingTask(); TaskEngine.getInstance().schedule(pingTask, JiveConstants.MINUTE, JiveConstants.MINUTE); } @OnWebSocketClose public void onClose(int statusCode, String reason) { closeSession(); } @OnWebSocketMessage public void onTextMethod(String stanza) { XMPPPacketReader reader = null; try { reader = readerPool.borrowObject(); Document doc = reader.read(new StringReader(stanza)); if (xmppSession == null) { initiateSession(doc.getRootElement()); } else { processStanza(doc.getRootElement()); } } catch (Exception ex) { Log.error("Failed to process XMPP stanza", ex); } finally { if (reader != null) { readerPool.returnObject(reader); } } } @OnWebSocketError public void onError(Throwable error) { Log.error("Error detected; session: " + wsSession, error); closeStream(new StreamError(StreamError.Condition.internal_server_error)); try { if (wsSession != null) { wsSession.disconnect(); } } catch (Exception e) { Log.error("Error disconnecting websocket", e); } } // local (package) visibility boolean isWebSocketOpen() { return wsSession != null && wsSession.isOpen(); } boolean isWebSocketSecure() { return wsSession != null && wsSession.isSecure(); } void closeWebSocket() { if (isWebSocketOpen()) { wsSession.close(); } wsSession = null; } void closeSession() { if (isWebSocketOpen()) { closeStream(null); } if (xmppSession != null) { xmppSession.close(); SessionManager.getInstance().removeSession(xmppSession); xmppSession = null; } } /** * Send an XML packet to the remote peer * * @param packet XML to be sent to client */ void deliver(String packet) { if (isWebSocketOpen()) { try { xmppSession.incrementServerPacketCount(); wsSession.getRemote().sendStringByFuture(packet); } catch (Exception e) { Log.error("Packet delivery failed; session: " + wsSession, e); Log.warn("Failed to deliver packet:\n" + packet); } } else { Log.warn("Failed to deliver packet; socket is closed:\n" + packet); } } static boolean isCompressionEnabled() { return JiveGlobals .getProperty(ConnectionSettings.Client.COMPRESSION_SETTINGS, Connection.CompressionPolicy.optional.toString()) .equalsIgnoreCase(Connection.CompressionPolicy.optional.toString()); } // helper/utility methods /* * Process stream headers/footers and authentication stanzas locally; * otherwise delegate stanza handling to the session packet router. */ private void processStanza(Element stanza) { try { String tag = stanza.getName(); if (STREAM_FOOTER.equals(tag)) { closeStream(null); } else if ("auth".equals(tag)) { // User is trying to authenticate using SASL startedSASL = true; // Process authentication stanza xmppSession.incrementClientPacketCount(); saslStatus = SASLAuthentication.handle(xmppSession, stanza); } else if (startedSASL && "response".equals(tag) || "abort".equals(tag)) { // User is responding to SASL challenge. Process response xmppSession.incrementClientPacketCount(); saslStatus = SASLAuthentication.handle(xmppSession, stanza); } else if (STREAM_HEADER.equals(tag)) { // restart the stream openStream(stanza.attributeValue(QName.get("lang", XMLConstants.XML_NS_URI), "en"), stanza.attributeValue("from")); configureStream(); } else if (Status.authenticated.equals(saslStatus)) { if (router == null) { if (isStreamManagementAvailable()) { router = new StreamManagementPacketRouter(xmppSession); } else { // fall back for older Openfire installations router = new SessionPacketRouter(xmppSession); } } router.route(stanza); } else { // require authentication Log.warn("Not authorized: " + stanza.asXML()); sendPacketError(stanza, PacketError.Condition.not_authorized); } } catch (UnknownStanzaException use) { Log.warn("Received invalid stanza: " + stanza.asXML()); sendPacketError(stanza, PacketError.Condition.bad_request); } catch (Exception ex) { Log.error("Failed to process incoming stanza: " + stanza.asXML(), ex); closeStream(new StreamError(StreamError.Condition.internal_server_error)); } } /* * Initiate the stream and corresponding XMPP session. */ private void initiateSession(Element stanza) { String host = stanza.attributeValue("to"); StreamError streamError = null; Locale language = Locale .forLanguageTag(stanza.attributeValue(QName.get("lang", XMLConstants.XML_NS_URI), "en")); if (STREAM_FOOTER.equals(stanza.getName())) { // an error occurred while setting up the session Log.warn("Client closed stream before session was established"); } else if (!STREAM_HEADER.equals(stanza.getName())) { streamError = new StreamError(StreamError.Condition.unsupported_stanza_type); Log.warn("Closing session due to incorrect stream header. Tag: " + stanza.getName()); } else if (!FRAMING_NAMESPACE.equals(stanza.getNamespace().getURI())) { // Validate the stream namespace (https://tools.ietf.org/html/rfc7395#section-3.3.2) streamError = new StreamError(StreamError.Condition.invalid_namespace); Log.warn("Closing session due to invalid namespace in stream header. Namespace: " + stanza.getNamespace().getURI()); } else if (!validateHost(host)) { streamError = new StreamError(StreamError.Condition.host_unknown); Log.warn("Closing session due to incorrect hostname in stream header. Host: " + host); } else { // valid stream; initiate session xmppSession = SessionManager.getInstance().createClientSession(wsConnection, language); xmppSession.setSessionData("ws", Boolean.TRUE); } if (xmppSession == null) { closeStream(streamError); } else { openStream(language.toLanguageTag(), stanza.attributeValue("from")); configureStream(); } } private boolean validateHost(String host) { boolean result = true; if (JiveGlobals.getBooleanProperty("xmpp.client.validate.host", false)) { result = XMPPServer.getInstance().getServerInfo().getXMPPDomain().equals(host); } return result; } /* * Prepare response for stream initiation (sasl) or stream restart (features). */ private void configureStream() { StringBuilder sb = new StringBuilder(250); sb.append("<stream:features xmlns:stream='http://etherx.jabber.org/streams'>"); if (saslStatus == null) { // Include available SASL Mechanisms sb.append(SASLAuthentication.getSASLMechanisms(xmppSession)); if (XMPPServer.getInstance().getIQRouter().supports("jabber:iq:auth")) { sb.append("<auth xmlns='http://jabber.org/features/iq-auth'/>"); } } else if (saslStatus.equals(Status.authenticated)) { // Include Stream features sb.append(String.format("<bind xmlns='%s'/>", "urn:ietf:params:xml:ns:xmpp-bind")); sb.append(String.format("<session xmlns='%s'><optional/></session>", "urn:ietf:params:xml:ns:xmpp-session")); if (isStreamManagementAvailable()) { sb.append(String.format("<sm xmlns='%s'/>", StreamManager.NAMESPACE_V3)); } } sb.append("</stream:features>"); deliver(sb.toString()); } private void openStream(String lang, String jid) { xmppSession.incrementClientPacketCount(); StringBuilder sb = new StringBuilder(250); sb.append("<open "); if (jid != null) { sb.append("to='").append(jid).append("' "); } sb.append("from='").append(XMPPServer.getInstance().getServerInfo().getXMPPDomain()).append("' "); sb.append("id='").append(xmppSession.getStreamID().toString()).append("' "); sb.append("xmlns='").append(FRAMING_NAMESPACE).append("' "); sb.append("xml:lang='").append(lang).append("' "); sb.append("version='1.0'/>"); deliver(sb.toString()); } private void closeStream(StreamError streamError) { if (isWebSocketOpen()) { if (streamError != null) { deliver(streamError.toXML()); } StringBuilder sb = new StringBuilder(250); sb.append("<close "); sb.append("xmlns='").append(FRAMING_NAMESPACE).append("'"); sb.append("/>"); deliver(sb.toString()); closeWebSocket(); } } private void sendPacketError(Element stanza, PacketError.Condition condition) { Element reply = stanza.createCopy(); reply.addAttribute("type", "error"); reply.addAttribute("to", stanza.attributeValue("from")); reply.addAttribute("from", stanza.attributeValue("to")); reply.add(new PacketError(condition).getElement()); deliver(reply.asXML()); } private synchronized void initializePool() { if (readerPool == null) { readerPool = new GenericObjectPool<XMPPPacketReader>(new XMPPPPacketReaderFactory()); readerPool.setMaxTotal(-1); readerPool.setBlockWhenExhausted(false); readerPool.setTestOnReturn(true); readerPool.setTimeBetweenEvictionRunsMillis(JiveConstants.MINUTE); } } private boolean isStreamManagementAvailable() { return JiveGlobals.getBooleanProperty(StreamManager.SM_ACTIVE, true); } //-- Keep-alive ping for idle peers private final class PingTask extends TimerTask { private boolean lastPingFailed = false; @Override public void run() { if (!isWebSocketOpen()) { TaskEngine.getInstance().cancelScheduledTask(pingTask); } else { long idleTime = System.currentTimeMillis() - JiveConstants.MINUTE; if (xmppSession.getLastActiveDate().getTime() >= idleTime) { return; } try { // see https://tools.ietf.org/html/rfc6455#section-5.5.2 wsSession.getRemote().sendPing(null); lastPingFailed = false; } catch (IOException ioe) { Log.error("Failed to ping remote peer: " + wsSession, ioe); if (lastPingFailed) { closeSession(); TaskEngine.getInstance().cancelScheduledTask(pingTask); } else { lastPingFailed = true; } } } } } }