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Smack/source/org/jivesoftware/smack/PacketReader.java
2007-02-21 00:57:31 +00:00

823 lines
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33 KiB
Java

/**
* $RCSfile$
* $Revision$
* $Date$
*
* Copyright 2003-2007 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.smack;
import org.jivesoftware.smack.filter.PacketFilter;
import org.jivesoftware.smack.packet.*;
import org.jivesoftware.smack.provider.IQProvider;
import org.jivesoftware.smack.provider.ProviderManager;
import org.jivesoftware.smack.util.PacketParserUtils;
import org.xmlpull.mxp1.MXParser;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import java.io.IOException;
import java.util.*;
import java.util.concurrent.*;
/**
* Listens for XML traffic from the XMPP server and parses it into packet objects.
* The packet reader also manages all packet listeners and collectors.<p>
*
* @see PacketCollector
* @see PacketListener
* @author Matt Tucker
*/
class PacketReader {
private Thread readerThread;
private ExecutorService listenerExecutor;
private XMPPConnection connection;
private XmlPullParser parser;
private boolean done;
private Collection<PacketCollector> collectors = new ConcurrentLinkedQueue<PacketCollector>();
protected final Map<PacketListener, ListenerWrapper> listeners =
new ConcurrentHashMap<PacketListener, ListenerWrapper>();
protected final Collection<ConnectionListener> connectionListeners =
new CopyOnWriteArrayList<ConnectionListener>();
private String connectionID = null;
private Semaphore connectionSemaphore;
protected PacketReader(final XMPPConnection connection) {
this.connection = connection;
this.init();
}
/**
* Initializes the reader in order to be used. The reader is initialized during the
* first connection and when reconnecting due to an abruptly disconnection.
*/
protected void init() {
done = false;
connectionID = null;
readerThread = new Thread() {
public void run() {
parsePackets(this);
}
};
readerThread.setName("Smack Packet Reader (" + connection.connectionCounterValue + ")");
readerThread.setDaemon(true);
// Create an executor to deliver incoming packets to listeners. We'll use a single
// thread with an unbounded queue.
listenerExecutor = Executors.newSingleThreadExecutor(new ThreadFactory() {
public Thread newThread(Runnable runnable) {
Thread thread = new Thread(runnable,
"Smack Listener Processor (" + connection.connectionCounterValue + ")");
thread.setDaemon(true);
return thread;
}
});
resetParser();
}
/**
* Creates a new packet collector for this reader. A packet filter determines
* which packets will be accumulated by the collector.
*
* @param packetFilter the packet filter to use.
* @return a new packet collector.
*/
public PacketCollector createPacketCollector(PacketFilter packetFilter) {
PacketCollector collector = new PacketCollector(this, packetFilter);
collectors.add(collector);
// Add the collector to the list of active collector.
return collector;
}
protected void cancelPacketCollector(PacketCollector packetCollector) {
collectors.remove(packetCollector);
}
/**
* Registers a packet listener with this reader. A packet filter determines
* which packets will be delivered to the listener.
*
* @param packetListener the packet listener to notify of new packets.
* @param packetFilter the packet filter to use.
*/
public void addPacketListener(PacketListener packetListener, PacketFilter packetFilter) {
ListenerWrapper wrapper = new ListenerWrapper(packetListener, packetFilter);
listeners.put(packetListener, wrapper);
}
/**
* Removes a packet listener.
*
* @param packetListener the packet listener to remove.
*/
public void removePacketListener(PacketListener packetListener) {
listeners.remove(packetListener);
}
/**
* Starts the packet reader thread and returns once a connection to the server
* has been established. A connection will be attempted for a maximum of five
* seconds. An XMPPException will be thrown if the connection fails.
*
* @throws XMPPException if the server fails to send an opening stream back
* for more than five seconds.
*/
public void startup() throws XMPPException {
connectionSemaphore = new Semaphore(1);
readerThread.start();
// Wait for stream tag before returing. We'll wait a couple of seconds before
// giving up and throwing an error.
try {
connectionSemaphore.acquire();
// A waiting thread may be woken up before the wait time or a notify
// (although this is a rare thing). Therefore, we continue waiting
// until either a connectionID has been set (and hence a notify was
// made) or the total wait time has elapsed.
int waitTime = SmackConfiguration.getPacketReplyTimeout();
connectionSemaphore.tryAcquire(3 * waitTime, TimeUnit.MILLISECONDS);
}
catch (InterruptedException ie) {
// Ignore.
}
if (connectionID == null) {
throw new XMPPException("Connection failed. No response from server.");
}
else {
connection.connectionID = connectionID;
}
}
/**
* Shuts the packet reader down.
*/
public void shutdown() {
// Notify connection listeners of the connection closing if done hasn't already been set.
if (!done) {
for (ConnectionListener listener : connectionListeners) {
try {
listener.connectionClosed();
}
catch (Exception e) {
// Cath and print any exception so we can recover
// from a faulty listener and finish the shutdown process
e.printStackTrace();
}
}
}
done = true;
// Shut down the listener executor.
listenerExecutor.shutdown();
}
/**
* Cleans up all resources used by the packet reader.
*/
void cleanup() {
connectionListeners.clear();
listeners.clear();
collectors.clear();
}
/**
* Sends out a notification that there was an error with the connection
* and closes the connection.
*
* @param e the exception that causes the connection close event.
*/
void notifyConnectionError(Exception e) {
done = true;
// Closes the connection temporary. A reconnection is possible
connection.shutdown(new Presence(Presence.Type.unavailable));
// Print the stack trace to help catch the problem
e.printStackTrace();
// Notify connection listeners of the error.
for (ConnectionListener listener : connectionListeners) {
try {
listener.connectionClosedOnError(e);
}
catch (Exception e2) {
// Cath and print any exception so we can recover
// from a faulty listener
e2.printStackTrace();
}
}
}
/**
* Sends a notification indicating that the connection was reconnected successfully.
*/
protected void notifyReconnection() {
// Notify connection listeners of the reconnection.
for (ConnectionListener listener : connectionListeners) {
try {
listener.reconnectionSuccessful();
}
catch (Exception e) {
// Cath and print any exception so we can recover
// from a faulty listener
e.printStackTrace();
}
}
}
/**
* Resets the parser using the latest connection's reader. Reseting the parser is necessary
* when the plain connection has been secured or when a new opening stream element is going
* to be sent by the server.
*/
private void resetParser() {
try {
parser = new MXParser();
parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, true);
parser.setInput(connection.reader);
}
catch (XmlPullParserException xppe) {
xppe.printStackTrace();
}
}
/**
* Parse top-level packets in order to process them further.
*
* @param thread the thread that is being used by the reader to parse incoming packets.
*/
private void parsePackets(Thread thread) {
try {
int eventType = parser.getEventType();
do {
if (eventType == XmlPullParser.START_TAG) {
if (parser.getName().equals("message")) {
processPacket(PacketParserUtils.parseMessage(parser));
}
else if (parser.getName().equals("iq")) {
processPacket(parseIQ(parser));
}
else if (parser.getName().equals("presence")) {
processPacket(PacketParserUtils.parsePresence(parser));
}
// We found an opening stream. Record information about it, then notify
// the connectionID lock so that the packet reader startup can finish.
else if (parser.getName().equals("stream")) {
// Ensure the correct jabber:client namespace is being used.
if ("jabber:client".equals(parser.getNamespace(null))) {
// Get the connection id.
for (int i=0; i<parser.getAttributeCount(); i++) {
if (parser.getAttributeName(i).equals("id")) {
// Save the connectionID
connectionID = parser.getAttributeValue(i);
if (!"1.0".equals(parser.getAttributeValue("", "version"))) {
// Notify that a stream has been opened if the
// server is not XMPP 1.0 compliant otherwise make the
// notification after TLS has been negotiated or if TLS
// is not supported
releaseConnectionIDLock();
}
}
else if (parser.getAttributeName(i).equals("from")) {
// Use the server name that the server says that it is.
connection.serviceName = parser.getAttributeValue(i);
}
}
}
}
else if (parser.getName().equals("error")) {
throw new XMPPException(parseStreamError(parser));
}
else if (parser.getName().equals("features")) {
parseFeatures(parser);
}
else if (parser.getName().equals("proceed")) {
// Secure the connection by negotiating TLS
connection.proceedTLSReceived();
// Reset the state of the parser since a new stream element is going
// to be sent by the server
resetParser();
}
else if (parser.getName().equals("failure")) {
String namespace = parser.getNamespace(null);
if ("urn:ietf:params:xml:ns:xmpp-tls".equals(namespace)) {
// TLS negotiation has failed. The server will close the connection
throw new Exception("TLS negotiation has failed");
}
else if ("http://jabber.org/protocol/compress".equals(namespace)) {
// Stream compression has been denied. This is a recoverable
// situation. It is still possible to authenticate and
// use the connection but using an uncompressed connection
connection.streamCompressionDenied();
}
else {
// SASL authentication has failed. The server may close the connection
// depending on the number of retries
connection.getSASLAuthentication().authenticationFailed();
}
}
else if (parser.getName().equals("challenge")) {
// The server is challenging the SASL authentication made by the client
connection.getSASLAuthentication().challengeReceived(parser.nextText());
}
else if (parser.getName().equals("success")) {
// We now need to bind a resource for the connection
// Open a new stream and wait for the response
connection.packetWriter.openStream();
// Reset the state of the parser since a new stream element is going
// to be sent by the server
resetParser();
// The SASL authentication with the server was successful. The next step
// will be to bind the resource
connection.getSASLAuthentication().authenticated();
}
else if (parser.getName().equals("compressed")) {
// Server confirmed that it's possible to use stream compression. Start
// stream compression
connection.startStreamCompression();
// Reset the state of the parser since a new stream element is going
// to be sent by the server
resetParser();
}
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("stream")) {
// Disconnect the connection
connection.disconnect();
}
}
eventType = parser.next();
} while (!done && eventType != XmlPullParser.END_DOCUMENT && thread == readerThread);
}
catch (Exception e) {
if (!done) {
// Close the connection and notify connection listeners of the
// error.
notifyConnectionError(e);
}
}
}
/**
* Releases the connection ID lock so that the thread that was waiting can resume. The
* lock will be released when one of the following three conditions is met:<p>
*
* 1) An opening stream was sent from a non XMPP 1.0 compliant server
* 2) Stream features were received from an XMPP 1.0 compliant server that does not support TLS
* 3) TLS negotiation was successful
*
*/
private void releaseConnectionIDLock() {
connectionSemaphore.release();
}
/**
* Processes a packet after it's been fully parsed by looping through the installed
* packet collectors and listeners and letting them examine the packet to see if
* they are a match with the filter.
*
* @param packet the packet to process.
*/
private void processPacket(Packet packet) {
if (packet == null) {
return;
}
// Loop through all collectors and notify the appropriate ones.
for (PacketCollector collector: collectors) {
collector.processPacket(packet);
}
// Deliver the incoming packet to listeners.
listenerExecutor.submit(new ListenerNotification(packet));
}
private StreamError parseStreamError(XmlPullParser parser) throws IOException,
XmlPullParserException {
StreamError streamError = null;
boolean done = false;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
streamError = new StreamError(parser.getName());
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("error")) {
done = true;
}
}
}
return streamError;
}
private void parseFeatures(XmlPullParser parser) throws Exception {
boolean startTLSReceived = false;
boolean startTLSRequired = false;
boolean done = false;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
if (parser.getName().equals("starttls")) {
startTLSReceived = true;
}
else if (parser.getName().equals("mechanisms")) {
// The server is reporting available SASL mechanisms. Store this information
// which will be used later while logging (i.e. authenticating) into
// the server
connection.getSASLAuthentication()
.setAvailableSASLMethods(parseMechanisms(parser));
}
else if (parser.getName().equals("bind")) {
// The server requires the client to bind a resource to the stream
connection.getSASLAuthentication().bindingRequired();
}
else if (parser.getName().equals("session")) {
// The server supports sessions
connection.getSASLAuthentication().sessionsSupported();
}
else if (parser.getName().equals("compression")) {
// The server supports stream compression
connection.setAvailableCompressionMethods(parseCompressionMethods(parser));
}
else if (parser.getName().equals("register")) {
connection.getAccountManager().setSupportsAccountCreation(true);
}
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("starttls")) {
// Confirm the server that we want to use TLS
connection.startTLSReceived(startTLSRequired);
}
else if (parser.getName().equals("required") && startTLSReceived) {
startTLSRequired = true;
}
else if (parser.getName().equals("features")) {
done = true;
}
}
}
// If TLS is required but the server doesn't offer it, disconnect
// from the server and throw an error. First check if we've already negotiated TLS
// and are secure, however (features get parsed a second time after TLS is established).
if (!connection.isSecureConnection()) {
if (!startTLSReceived && connection.getConfiguration().getSecurityMode() ==
ConnectionConfiguration.SecurityMode.required)
{
throw new XMPPException("Server does not support security (TLS), " +
"but security required by connection configuration.",
new XMPPError(XMPPError.Condition.forbidden));
}
}
// Release the lock after TLS has been negotiated or we are not insterested in TLS
if (!startTLSReceived || connection.getConfiguration().getSecurityMode() ==
ConnectionConfiguration.SecurityMode.disabled)
{
releaseConnectionIDLock();
}
}
/**
* Returns a collection of Stings with the mechanisms included in the mechanisms stanza.
*
* @param parser the XML parser, positioned at the start of an IQ packet.
* @return a collection of Stings with the mechanisms included in the mechanisms stanza.
* @throws Exception if an exception occurs while parsing the stanza.
*/
private Collection<String> parseMechanisms(XmlPullParser parser) throws Exception {
List<String> mechanisms = new ArrayList<String>();
boolean done = false;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
String elementName = parser.getName();
if (elementName.equals("mechanism")) {
mechanisms.add(parser.nextText());
}
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("mechanisms")) {
done = true;
}
}
}
return mechanisms;
}
private Collection<String> parseCompressionMethods(XmlPullParser parser)
throws IOException, XmlPullParserException {
List<String> methods = new ArrayList<String>();
boolean done = false;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
String elementName = parser.getName();
if (elementName.equals("method")) {
methods.add(parser.nextText());
}
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("compression")) {
done = true;
}
}
}
return methods;
}
/**
* Parses an IQ packet.
*
* @param parser the XML parser, positioned at the start of an IQ packet.
* @return an IQ object.
* @throws Exception if an exception occurs while parsing the packet.
*/
private IQ parseIQ(XmlPullParser parser) throws Exception {
IQ iqPacket = null;
String id = parser.getAttributeValue("", "id");
String to = parser.getAttributeValue("", "to");
String from = parser.getAttributeValue("", "from");
IQ.Type type = IQ.Type.fromString(parser.getAttributeValue("", "type"));
XMPPError error = null;
boolean done = false;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
String elementName = parser.getName();
String namespace = parser.getNamespace();
if (elementName.equals("error")) {
error = PacketParserUtils.parseError(parser);
}
else if (elementName.equals("query") && namespace.equals("jabber:iq:auth")) {
iqPacket = parseAuthentication(parser);
}
else if (elementName.equals("query") && namespace.equals("jabber:iq:roster")) {
iqPacket = parseRoster(parser);
}
else if (elementName.equals("query") && namespace.equals("jabber:iq:register")) {
iqPacket = parseRegistration(parser);
}
else if (elementName.equals("bind") &&
namespace.equals("urn:ietf:params:xml:ns:xmpp-bind")) {
iqPacket = parseResourceBinding(parser);
}
// Otherwise, see if there is a registered provider for
// this element name and namespace.
else {
Object provider = ProviderManager.getInstance().getIQProvider(elementName, namespace);
if (provider != null) {
if (provider instanceof IQProvider) {
iqPacket = ((IQProvider)provider).parseIQ(parser);
}
else if (provider instanceof Class) {
iqPacket = (IQ)PacketParserUtils.parseWithIntrospection(elementName,
(Class)provider, parser);
}
}
}
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("iq")) {
done = true;
}
}
}
// Decide what to do when an IQ packet was not understood
if (iqPacket == null) {
if (IQ.Type.GET == type || IQ.Type.SET == type ) {
// If the IQ stanza is of type "get" or "set" containing a child element
// qualified by a namespace it does not understand, then answer an IQ of
// type "error" with code 501 ("feature-not-implemented")
iqPacket = new IQ() {
public String getChildElementXML() {
return null;
}
};
iqPacket.setPacketID(id);
iqPacket.setTo(from);
iqPacket.setFrom(to);
iqPacket.setType(IQ.Type.ERROR);
iqPacket.setError(new XMPPError(XMPPError.Condition.feature_not_implemented));
connection.sendPacket(iqPacket);
return null;
}
else {
// If an IQ packet wasn't created above, create an empty IQ packet.
iqPacket = new IQ() {
public String getChildElementXML() {
return null;
}
};
}
}
// Set basic values on the iq packet.
iqPacket.setPacketID(id);
iqPacket.setTo(to);
iqPacket.setFrom(from);
iqPacket.setType(type);
iqPacket.setError(error);
return iqPacket;
}
private Authentication parseAuthentication(XmlPullParser parser) throws Exception {
Authentication authentication = new Authentication();
boolean done = false;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
if (parser.getName().equals("username")) {
authentication.setUsername(parser.nextText());
}
else if (parser.getName().equals("password")) {
authentication.setPassword(parser.nextText());
}
else if (parser.getName().equals("digest")) {
authentication.setDigest(parser.nextText());
}
else if (parser.getName().equals("resource")) {
authentication.setResource(parser.nextText());
}
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("query")) {
done = true;
}
}
}
return authentication;
}
private RosterPacket parseRoster(XmlPullParser parser) throws Exception {
RosterPacket roster = new RosterPacket();
boolean done = false;
RosterPacket.Item item = null;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
if (parser.getName().equals("item")) {
String jid = parser.getAttributeValue("", "jid");
String name = parser.getAttributeValue("", "name");
// Create packet.
item = new RosterPacket.Item(jid, name);
// Set status.
String ask = parser.getAttributeValue("", "ask");
RosterPacket.ItemStatus status = RosterPacket.ItemStatus.fromString(ask);
item.setItemStatus(status);
// Set type.
String subscription = parser.getAttributeValue("", "subscription");
RosterPacket.ItemType type = RosterPacket.ItemType.valueOf(subscription);
item.setItemType(type);
}
if (parser.getName().equals("group") && item!= null) {
item.addGroupName(parser.nextText());
}
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("item")) {
roster.addRosterItem(item);
}
if (parser.getName().equals("query")) {
done = true;
}
}
}
return roster;
}
private Registration parseRegistration(XmlPullParser parser) throws Exception {
Registration registration = new Registration();
Map<String, String> fields = null;
boolean done = false;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
// Any element that's in the jabber:iq:register namespace,
// attempt to parse it if it's in the form <name>value</name>.
if (parser.getNamespace().equals("jabber:iq:register")) {
String name = parser.getName();
String value = "";
if (fields == null) {
fields = new HashMap<String, String>();
}
if (parser.next() == XmlPullParser.TEXT) {
value = parser.getText();
}
// Ignore instructions, but anything else should be added to the map.
if (!name.equals("instructions")) {
fields.put(name, value);
}
else {
registration.setInstructions(value);
}
}
// Otherwise, it must be a packet extension.
else {
registration.addExtension(
PacketParserUtils.parsePacketExtension(
parser.getName(),
parser.getNamespace(),
parser));
}
}
else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("query")) {
done = true;
}
}
}
registration.setAttributes(fields);
return registration;
}
private Bind parseResourceBinding(XmlPullParser parser) throws IOException,
XmlPullParserException
{
Bind bind = new Bind();
boolean done = false;
while (!done) {
int eventType = parser.next();
if (eventType == XmlPullParser.START_TAG) {
if (parser.getName().equals("resource")) {
bind.setResource(parser.nextText());
}
else if (parser.getName().equals("jid")) {
bind.setJid(parser.nextText());
}
} else if (eventType == XmlPullParser.END_TAG) {
if (parser.getName().equals("bind")) {
done = true;
}
}
}
return bind;
}
/**
* A runnable to notify all listeners of a packet.
*/
private class ListenerNotification implements Runnable {
private Packet packet;
public ListenerNotification(Packet packet) {
this.packet = packet;
}
public void run() {
for (ListenerWrapper listenerWrapper : listeners.values()) {
listenerWrapper.notifyListener(packet);
}
}
}
/**
* A wrapper class to associate a packet filter with a listener.
*/
private static class ListenerWrapper {
private PacketListener packetListener;
private PacketFilter packetFilter;
public ListenerWrapper(PacketListener packetListener, PacketFilter packetFilter) {
this.packetListener = packetListener;
this.packetFilter = packetFilter;
}
public void notifyListener(Packet packet) {
if (packetFilter == null || packetFilter.accept(packet)) {
packetListener.processPacket(packet);
}
}
}
}