Java tutorial
/* * ============================================================================ * The Apache Software License, Version 1.1 * ============================================================================ * * Copyright (C) 2002 The Apache Software Foundation. All rights reserved. * * Redistribution and use in source and binary forms, with or without modifica- * tion, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * 3. The end-user documentation included with the redistribution, if any, must * include the following acknowledgment: "This product includes software * developed by SuperBonBon Industries (http://www.sbbi.net/)." * Alternately, this acknowledgment may appear in the software itself, if * and wherever such third-party acknowledgments normally appear. * * 4. The names "UPNPLib" and "SuperBonBon Industries" must not be * used to endorse or promote products derived from this software without * prior written permission. For written permission, please contact * info@sbbi.net. * * 5. Products derived from this software may not be called * "SuperBonBon Industries", nor may "SBBI" appear in their name, * without prior written permission of SuperBonBon Industries. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, * INDIRECT,INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU- * DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * This software consists of voluntary contributions made by many individuals * on behalf of SuperBonBon Industries. For more information on * SuperBonBon Industries, please see <http://www.sbbi.net/>. */ package net.sbbi.upnp; import java.io.*; import java.net.*; import java.util.*; import org.apache.commons.logging.*; /** * SSDP messages listener Thread, notify registered objects implementing the interface DiscoveryEventHandler</br> * when a device joins the networks or leaves it.<br/> * The listener thread is set to only accept matching device description and broadcast message sender IP * to avoid a security flaw with the protocol. If you are not happy with such behaviour * you can set the net.sbbi.upnp.ddos.matchip system property to false to avoid this check. * @author <a href="mailto:superbonbon@sbbi.net">SuperBonBon</a> * @version 1.0 */ public class DiscoveryAdvertisement implements Runnable { private final static Log log = LogFactory.getLog(DiscoveryAdvertisement.class); private static boolean MATCH_IP = true; static { String prop = System.getProperty("net.sbbi.upnp.ddos.matchip"); if (prop != null && prop.equals("false")) MATCH_IP = false; } private static final int DEFAULT_TIMEOUT = 250; public final static int EVENT_SSDP_ALIVE = 0; public final static int EVENT_SSDP_BYE_BYE = 1; private final static String NTS_SSDP_ALIVE = "ssdp:alive"; private final static String NTS_SSDP_BYE_BYE = "ssdp:byebye"; private final static String NT_ALL_EVENTS = "DiscoveryAdvertisement:nt:allevents"; private Map byeByeRegistered = new HashMap(); private Map aliveRegistered = new HashMap(); private Map USNPerIP = new HashMap(); private final Object REGISTRATION_PROCESS = new Object(); private final static DiscoveryAdvertisement singleton = new DiscoveryAdvertisement(); private boolean inService = false; private boolean daemon = true; private java.net.MulticastSocket skt; private DatagramPacket input; private DiscoveryAdvertisement() { } public final static DiscoveryAdvertisement getInstance() { return singleton; } public void setDaemon(boolean daemon) { this.daemon = daemon; } /** * Registers an event category sent by UPNP devices * @param notificationEvent the event type, either DiscoveryAdvertisement.EVENT_SSDP_ALIVE * or DiscoveryAdvertisement.EVENT_SSDP_BYE_BYE * @param nt the type of device advertisement, upnp:rootdevice will return you all advertisement in relation with nt upnp:rootdevice * a null value specify that all nt type are wanted * @param eventHandler the events handler, this objet will receive notifications.. * @throws IOException if an error ocurs when the SSDP events listeners threads starts */ public void registerEvent(int notificationEvent, String nt, DiscoveryEventHandler eventHandler) throws IOException { synchronized (REGISTRATION_PROCESS) { if (!inService) startDevicesListenerThread(); if (nt == null) nt = NT_ALL_EVENTS; if (notificationEvent == EVENT_SSDP_ALIVE) { Set handlers = (Set) aliveRegistered.get(nt); if (handlers == null) { handlers = new HashSet(); aliveRegistered.put(nt, handlers); } handlers.add(eventHandler); } else if (notificationEvent == EVENT_SSDP_BYE_BYE) { Set handlers = (Set) byeByeRegistered.get(nt); if (handlers == null) { handlers = new HashSet(); byeByeRegistered.put(nt, handlers); } handlers.add(eventHandler); } else { throw new IllegalArgumentException("Unknown notificationEvent type"); } } } /** * Unregisters an event category sent by UPNP devices * @param notificationEvent the event type, either DiscoveryAdvertisement.EVENT_SSDP_ALIVE * or DiscoveryAdvertisement.EVENT_SSDP_BYE_BYE * @param nt the type of device advertisement, upnp:rootdevice will unregister all advertisement in relation with nt upnp:rootdevice * a null value specify that all nt type are unregistered * @param eventHandler the events handler that needs to be unregistred. */ public void unRegisterEvent(int notificationEvent, String nt, DiscoveryEventHandler eventHandler) { synchronized (REGISTRATION_PROCESS) { if (nt == null) nt = NT_ALL_EVENTS; if (notificationEvent == EVENT_SSDP_ALIVE) { Set handlers = (Set) aliveRegistered.get(nt); if (handlers != null) { handlers.remove(eventHandler); if (handlers.size() == 0) { aliveRegistered.remove(nt); } } } else if (notificationEvent == EVENT_SSDP_BYE_BYE) { Set handlers = (Set) byeByeRegistered.get(nt); if (handlers != null) { handlers.remove(eventHandler); if (handlers.size() == 0) { byeByeRegistered.remove(nt); } } } else { throw new IllegalArgumentException("Unknown notificationEvent type"); } if (aliveRegistered.size() == 0 && byeByeRegistered.size() == 0) { stopDevicesListenerThread(); } } } private void startDevicesListenerThread() throws IOException { synchronized (singleton) { if (!inService) { this.startMultiCastSocket(); Thread deamon = new Thread(this, "DiscoveryAdvertisement daemon"); deamon.setDaemon(daemon); deamon.start(); // wait for the thread to be started while (!inService) { // let's wait a few ms try { Thread.sleep(2); } catch (InterruptedException ex) { // don t care } } } } } private void stopDevicesListenerThread() { synchronized (singleton) { inService = false; } } private void startMultiCastSocket() throws IOException { skt = new java.net.MulticastSocket(null); skt.bind(new InetSocketAddress(InetAddress.getByName("0.0.0.0"), Discovery.SSDP_PORT)); skt.setTimeToLive(Discovery.DEFAULT_TTL); skt.setSoTimeout(DEFAULT_TIMEOUT); skt.joinGroup(InetAddress.getByName(Discovery.SSDP_IP)); byte[] buf = new byte[2048]; input = new DatagramPacket(buf, buf.length); } public void run() { if (!Thread.currentThread().getName().equals("DiscoveryAdvertisement daemon")) { throw new RuntimeException("No right to call this method"); } inService = true; while (inService) { try { listenBroadCast(); } catch (SocketTimeoutException ex) { // ignoring } catch (IOException ioEx) { log.error("IO Exception during UPNP DiscoveryAdvertisement messages listening thread", ioEx); } catch (Exception ex) { log.error( "Fatal Error during UPNP DiscoveryAdvertisement messages listening thread, thread will exit", ex); inService = false; aliveRegistered.clear(); byeByeRegistered.clear(); USNPerIP.clear(); } } try { skt.leaveGroup(InetAddress.getByName(Discovery.SSDP_IP)); skt.close(); } catch (Exception ex) { // ignoring } } private void listenBroadCast() throws IOException { skt.receive(input); InetAddress from = input.getAddress(); String received = new String(input.getData(), input.getOffset(), input.getLength()); HttpResponse msg = null; try { msg = new HttpResponse(received); } catch (IllegalArgumentException ex) { // crappy http sent if (log.isDebugEnabled()) log.debug("Skipping uncompliant HTTP message " + received); return; } String header = msg.getHeader(); if (header != null && header.startsWith("NOTIFY")) { if (log.isDebugEnabled()) log.debug(received); String ntsField = msg.getHTTPHeaderField("nts"); if (ntsField == null || ntsField.trim().length() == 0) { if (log.isDebugEnabled()) log.debug("Skipping SSDP message, missing HTTP header 'ntsField' field"); return; } if (ntsField.equals(NTS_SSDP_ALIVE)) { String deviceDescrLoc = msg.getHTTPHeaderField("location"); if (deviceDescrLoc == null || deviceDescrLoc.trim().length() == 0) { if (log.isDebugEnabled()) log.debug("Skipping SSDP message, missing HTTP header 'location' field"); return; } URL loc = new URL(deviceDescrLoc); if (MATCH_IP) { InetAddress locHost = InetAddress.getByName(loc.getHost()); if (!from.equals(locHost)) { log.warn("Discovery message sender IP " + from + " does not match device description IP " + locHost + " skipping message, set the net.sbbi.upnp.ddos.matchip system property" + " to false to avoid this check"); return; } } String nt = msg.getHTTPHeaderField("nt"); if (nt == null || nt.trim().length() == 0) { if (log.isDebugEnabled()) log.debug("Skipping SSDP message, missing HTTP header 'nt' field"); return; } String maxAge = msg.getHTTPFieldElement("Cache-Control", "max-age"); if (maxAge == null || maxAge.trim().length() == 0) { if (log.isDebugEnabled()) log.debug("Skipping SSDP message, missing HTTP header 'max-age' field"); return; } String usn = msg.getHTTPHeaderField("usn"); if (usn == null || usn.trim().length() == 0) { if (log.isDebugEnabled()) log.debug("Skipping SSDP message, missing HTTP header 'usn' field"); return; } USNPerIP.put(usn, from); String udn = usn; int index = udn.indexOf("::"); if (index != -1) udn = udn.substring(0, index); synchronized (REGISTRATION_PROCESS) { Set handlers = (Set) aliveRegistered.get(NT_ALL_EVENTS); if (handlers != null) { for (Iterator i = handlers.iterator(); i.hasNext();) { DiscoveryEventHandler eventHandler = (DiscoveryEventHandler) i.next(); eventHandler.eventSSDPAlive(usn, udn, nt, maxAge, loc); } } handlers = (Set) aliveRegistered.get(nt); if (handlers != null) { for (Iterator i = handlers.iterator(); i.hasNext();) { DiscoveryEventHandler eventHandler = (DiscoveryEventHandler) i.next(); eventHandler.eventSSDPAlive(usn, udn, nt, maxAge, loc); } } } } else if (ntsField.equals(NTS_SSDP_BYE_BYE)) { String usn = msg.getHTTPHeaderField("usn"); if (usn == null || usn.trim().length() == 0) { if (log.isDebugEnabled()) log.debug("Skipping SSDP message, missing HTTP header 'usn' field"); return; } String nt = msg.getHTTPHeaderField("nt"); if (nt == null || nt.trim().length() == 0) { if (log.isDebugEnabled()) log.debug("Skipping SSDP message, missing HTTP header 'nt' field"); return; } InetAddress originalAliveSenderIp = (InetAddress) USNPerIP.get(usn); if (originalAliveSenderIp != null) { // we check that the sender ip of message for the usn // match the sender ip of the alive message for wich the usn // has been received if (!originalAliveSenderIp.equals(from)) { // someone else is trying to say that the usn is leaving // since IP do not match we skip the message return; } } String udn = usn; int index = udn.indexOf("::"); if (index != -1) udn = udn.substring(0, index); synchronized (REGISTRATION_PROCESS) { Set handlers = (Set) byeByeRegistered.get(NT_ALL_EVENTS); if (handlers != null) { for (Iterator i = handlers.iterator(); i.hasNext();) { DiscoveryEventHandler eventHandler = (DiscoveryEventHandler) i.next(); eventHandler.eventSSDPByeBye(usn, udn, nt); } } handlers = (Set) byeByeRegistered.get(nt); if (handlers != null) { for (Iterator i = handlers.iterator(); i.hasNext();) { DiscoveryEventHandler eventHandler = (DiscoveryEventHandler) i.next(); eventHandler.eventSSDPByeBye(usn, udn, nt); } } } } else { log.warn("Unvalid NTS field value (" + ntsField + ") received in NOTIFY message :" + received); } } } }