/**
* $RCSfile$
* $Revision$
* $Date$
*
* 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.Connection.ListenerWrapper;
import org.jivesoftware.smack.packet.*;
import org.jivesoftware.smack.sasl.SASLMechanism.Challenge;
import org.jivesoftware.smack.sasl.SASLMechanism.Failure;
import org.jivesoftware.smack.sasl.SASLMechanism.Success;
import org.jivesoftware.smack.util.PacketParserUtils;
import org.xmlpull.mxp1.MXParser;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import java.util.concurrent.*;
/**
* Listens for XML traffic from the XMPP server and parses it into packet objects.
* The packet reader also invokes all packet listeners and collectors.<p>
*
* @see Connection#createPacketCollector
* @see Connection#addPacketListener
* @author Matt Tucker
*/
class PacketReader {
private Thread readerThread;
private ExecutorService listenerExecutor;
private XMPPConnection connection;
private XmlPullParser parser;
volatile boolean done;
private String connectionID = null;
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();
}
/**
* 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.
*/
synchronized public void startup() throws XMPPException {
readerThread.start();
// Wait for stream tag before returning. We'll wait a couple of seconds before
// giving up and throwing an error.
try {
// 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();
wait(3 * waitTime);
}
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 : connection.getConnectionListeners()) {
try {
listener.connectionClosed();
}
catch (Exception e) {
// Catch 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() {
connection.recvListeners.clear();
connection.collectors.clear();
}
/**
* 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(PacketParserUtils.parseIQ(parser, connection));
}
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.config.setServiceName(parser.getAttributeValue(i));
}
}
}
}
else if (parser.getName().equals("error")) {
throw new XMPPException(PacketParserUtils.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
final Failure failure = PacketParserUtils.parseSASLFailure(parser);
processPacket(failure);
connection.getSASLAuthentication().authenticationFailed(failure.getCondition());
}
}
else if (parser.getName().equals("challenge")) {
// The server is challenging the SASL authentication made by the client
String challengeData = parser.nextText();
processPacket(new Challenge(challengeData));
connection.getSASLAuthentication().challengeReceived(challengeData);
}
else if (parser.getName().equals("success")) {
processPacket(new Success(parser.nextText()));
// 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) {
// The exception can be ignored if the the connection is 'done'
// or if the it was caused because the socket got closed
if (!(done || connection.isSocketClosed())) {
// Close the connection and notify connection listeners of the
// error.
connection.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
*
*/
synchronized private void releaseConnectionIDLock() {
notify();
}
/**
* 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: connection.getPacketCollectors()) {
collector.processPacket(packet);
}
// Deliver the incoming packet to listeners.
listenerExecutor.submit(new ListenerNotification(packet));
}
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(PacketParserUtils.parseMechanisms(parser));
}
else if (parser.getName().equals("bind")) {
// The server requires the client to bind a resource to the stream
connection.getSASLAuthentication().bindingRequired();
}
// Set the entity caps node for the server if one is send
// See http://xmpp.org/extensions/xep-0115.html#stream
else if (parser.getName().equals("c")) {
String node = parser.getAttributeValue(null, "node");
String ver = parser.getAttributeValue(null, "ver");
if (ver != null && node != null) {
String capsNode = node + "#" + ver;
// In order to avoid a dependency from smack to smackx
// we have to set the services caps node in the connection
// and not directly in the EntityCapsManager
connection.setServiceCapsNode(capsNode);
}
}
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(PacketParserUtils.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();
}
}
/**
* 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 : connection.recvListeners.values()) {
listenerWrapper.notifyListener(packet);
}
}
}
}