Java tutorial
/** * $RCSfile: ServerSocketReader.java,v $ * $Revision: 3174 $ * $Date: 2005-12-08 17:41:00 -0300 (Thu, 08 Dec 2005) $ * * Copyright (C) 2005-2008 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.openfire.net; import java.io.IOException; import java.net.Socket; import java.util.concurrent.LinkedBlockingQueue; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; import org.dom4j.Element; import org.jivesoftware.openfire.PacketRouter; import org.jivesoftware.openfire.RoutingTable; import org.jivesoftware.openfire.auth.UnauthorizedException; import org.jivesoftware.openfire.interceptor.PacketRejectedException; import org.jivesoftware.openfire.session.LocalIncomingServerSession; import org.jivesoftware.util.JiveGlobals; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.xmlpull.v1.XmlPullParserException; import org.xmpp.packet.IQ; import org.xmpp.packet.Message; import org.xmpp.packet.Packet; import org.xmpp.packet.Presence; import org.xmpp.packet.StreamError; /** * A SocketReader specialized for server connections. This reader will be used when the open * stream contains a jabber:server namespace. Server-to-server communication requires two * TCP connections between the servers where one is used for sending packets whilst the other * connection is used for receiving packets. The connection used for receiving packets will use * a ServerSocketReader since the other connection will not receive packets.<p> * * The received packets will be routed using another thread to ensure that many received packets * could be routed at the same time. To avoid creating new threads every time a packet is received * each <tt>ServerSocketReader</tt> instance uses a {@link ThreadPoolExecutor}. By default the * maximum number of threads that the executor may have is 50. However, this value may be modified * by changing the property <b>xmpp.server.processing.max.threads</b>. * * @author Gaston Dombiak */ public class ServerSocketReader extends SocketReader { private static final Logger Log = LoggerFactory.getLogger(ServerSocketReader.class); /** * Pool of threads that are available for processing the requests. */ private ThreadPoolExecutor threadPool; public ServerSocketReader(PacketRouter router, RoutingTable routingTable, String serverName, Socket socket, SocketConnection connection, boolean useBlockingMode) { super(router, routingTable, serverName, socket, connection, useBlockingMode); // Create a pool of threads that will process received packets. If more threads are // required then the command will be executed on the SocketReader process int coreThreads = JiveGlobals.getIntProperty("xmpp.server.processing.core.threads", 2); int maxThreads = JiveGlobals.getIntProperty("xmpp.server.processing.max.threads", 50); int queueSize = JiveGlobals.getIntProperty("xmpp.server.processing.queue", 50); threadPool = new ThreadPoolExecutor(coreThreads, maxThreads, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(queueSize), new ThreadPoolExecutor.CallerRunsPolicy()); } /** * Processes the packet in another thread if the packet has not been rejected. * * @param packet the received packet. */ @Override protected void processIQ(final IQ packet) throws UnauthorizedException { try { packetReceived(packet); // Process the packet in another thread threadPool.execute(new Runnable() { public void run() { try { ServerSocketReader.super.processIQ(packet); } catch (UnauthorizedException e) { Log.error("Error processing packet", e); } } }); } catch (PacketRejectedException e) { Log.debug("IQ rejected: " + packet.toXML(), e); } } /** * Processes the packet in another thread if the packet has not been rejected. * * @param packet the received packet. */ @Override protected void processPresence(final Presence packet) throws UnauthorizedException { try { packetReceived(packet); // Process the packet in another thread threadPool.execute(new Runnable() { public void run() { try { ServerSocketReader.super.processPresence(packet); } catch (UnauthorizedException e) { Log.error("Error processing packet", e); } } }); } catch (PacketRejectedException e) { Log.debug("Presence rejected: " + packet.toXML(), e); } } /** * Processes the packet in another thread if the packet has not been rejected. * * @param packet the received packet. */ @Override protected void processMessage(final Message packet) throws UnauthorizedException { try { packetReceived(packet); // Process the packet in another thread threadPool.execute(new Runnable() { public void run() { try { ServerSocketReader.super.processMessage(packet); } catch (UnauthorizedException e) { Log.error("Error processing packet", e); } } }); } catch (PacketRejectedException e) { Log.debug("Message rejected: " + packet.toXML(), e); } } /** * Remote servers may send subsequent db:result packets so we need to process them in order * to validate new domains. * * @param doc the unknown DOM element that was received * @return true if the packet is a db:result packet otherwise false. */ @Override protected boolean processUnknowPacket(Element doc) { // Handle subsequent db:result packets if ("db".equals(doc.getNamespacePrefix()) && "result".equals(doc.getName())) { if (!((LocalIncomingServerSession) session).validateSubsequentDomain(doc)) { open = false; } return true; } else if ("db".equals(doc.getNamespacePrefix()) && "verify".equals(doc.getName())) { // The Receiving Server is reusing an existing connection for sending the // Authoritative Server a request for verification of a key ((LocalIncomingServerSession) session).verifyReceivedKey(doc); return true; } return false; } /** * Make sure that the received packet has a TO and FROM values defined and that it was sent * from a previously validated domain. If the packet does not matches any of the above * conditions then a PacketRejectedException will be thrown. * * @param packet the received packet. * @throws PacketRejectedException if the packet does not include a TO or FROM or if the packet * was sent from a domain that was not previously validated. */ private void packetReceived(Packet packet) throws PacketRejectedException { if (packet.getTo() == null || packet.getFrom() == null) { Log.debug("Closing IncomingServerSession due to packet with no TO or FROM: " + packet.toXML()); // Send a stream error saying that the packet includes no TO or FROM StreamError error = new StreamError(StreamError.Condition.improper_addressing); connection.deliverRawText(error.toXML()); // Close the underlying connection connection.close(); open = false; throw new PacketRejectedException("Packet with no TO or FROM attributes"); } else if (!((LocalIncomingServerSession) session).isValidDomain(packet.getFrom().getDomain())) { Log.debug("Closing IncomingServerSession due to packet with invalid domain: " + packet.toXML()); // Send a stream error saying that the packet includes an invalid FROM StreamError error = new StreamError(StreamError.Condition.invalid_from); connection.deliverRawText(error.toXML()); // Close the underlying connection connection.close(); open = false; throw new PacketRejectedException("Packet with no TO or FROM attributes"); } } @Override protected void shutdown() { super.shutdown(); // Shutdown the pool of threads that are processing packets sent by // the remote server threadPool.shutdown(); } @Override boolean createSession(String namespace) throws UnauthorizedException, XmlPullParserException, IOException { if ("jabber:server".equals(namespace)) { // The connected client is a server so create an IncomingServerSession session = LocalIncomingServerSession.createSession(serverName, reader, connection); return true; } return false; } @Override String getNamespace() { return "jabber:server"; } @Override public String getExtraNamespaces() { return "xmlns:db=\"jabber:server:dialback\""; } @Override String getName() { return "Server SR - " + hashCode(); } @Override boolean validateHost() { return true; } }