/**
*
* Copyright 2003-2007 Jive Software.
*
* 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.tcp;
import java.io.IOException;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.Packet;
import org.jivesoftware.smack.packet.Presence;
import org.jivesoftware.smack.parsing.ParsingExceptionCallback;
import org.jivesoftware.smack.parsing.UnparsablePacket;
import org.jivesoftware.smack.sasl.SASLMechanism.Challenge;
import org.jivesoftware.smack.sasl.SASLMechanism.SASLFailure;
import org.jivesoftware.smack.sasl.SASLMechanism.Success;
import org.jivesoftware.smack.util.PacketParserUtils;
import org.jivesoftware.smack.ConnectionConfiguration;
import org.jivesoftware.smack.SmackException;
import org.jivesoftware.smack.SmackException.NoResponseException;
import org.jivesoftware.smack.SmackException.SecurityRequiredException;
import org.jivesoftware.smack.XMPPException.StreamErrorException;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
/**
* 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 XMPPConnection#createPacketCollector
* @see XMPPConnection#addPacketListener
* @author Matt Tucker
*/
class PacketReader {
private Thread readerThread;
private XMPPTCPConnection connection;
private XmlPullParser parser;
/**
* Set to true if the last features stanza from the server has been parsed. A XMPP connection
* handshake can invoke multiple features stanzas, e.g. when TLS is activated a second feature
* stanza is send by the server. This is set to true once the last feature stanza has been
* parsed.
*/
private volatile boolean lastFeaturesParsed;
volatile boolean done;
protected PacketReader(final XMPPTCPConnection connection) throws SmackException {
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.
*
* @throws SmackException if the parser could not be reset.
*/
protected void init() throws SmackException {
done = false;
lastFeaturesParsed = false;
readerThread = new Thread() {
public void run() {
parsePackets(this);
}
};
readerThread.setName("Smack Packet Reader (" + connection.getConnectionCounter() + ")");
readerThread.setDaemon(true);
resetParser();
}
/**
* Starts the packet reader thread and returns once a connection to the server
* has been established or if the server's features could not be parsed within
* the connection's PacketReplyTimeout.
*
* @throws NoResponseException if the server fails to send an opening stream back
* within packetReplyTimeout.
* @throws IOException
*/
synchronized public void startup() throws NoResponseException, IOException {
readerThread.start();
try {
// Wait until either:
// - the servers last features stanza has been parsed
// - an exception is thrown while parsing
// - the timeout occurs
wait(connection.getPacketReplyTimeout());
}
catch (InterruptedException ie) {
// Ignore.
}
if (!lastFeaturesParsed) {
connection.throwConnectionExceptionOrNoResponse();
}
}
/**
* Shuts the packet reader down. This method simply sets the 'done' flag to true.
*/
public void shutdown() {
done = true;
}
/**
* 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.
*
* @throws SmackException if the parser could not be reset.
*/
private void resetParser() throws SmackException {
try {
parser = PacketParserUtils.newXmppParser();
parser.setInput(connection.getReader());
}
catch (XmlPullParserException e) {
throw new SmackException(e);
}
}
/**
* 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) {
int parserDepth = parser.getDepth();
ParsingExceptionCallback callback = connection.getParsingExceptionCallback();
if (parser.getName().equals("message")) {
Packet packet;
try {
packet = PacketParserUtils.parseMessage(parser);
} catch (Exception e) {
String content = PacketParserUtils.parseContentDepth(parser, parserDepth);
UnparsablePacket message = new UnparsablePacket(content, e);
if (callback != null) {
callback.handleUnparsablePacket(message);
}
// The parser is now at the end tag of the unparsable stanza. We need to advance to the next
// start tag in order to avoid an exception which would again lead to the execution of the
// catch block becoming effectively an endless loop.
eventType = parser.next();
continue;
}
connection.processPacket(packet);
}
else if (parser.getName().equals("iq")) {
IQ iq;
try {
iq = PacketParserUtils.parseIQ(parser, connection);
} catch (Exception e) {
String content = PacketParserUtils.parseContentDepth(parser, parserDepth);
UnparsablePacket message = new UnparsablePacket(content, e);
if (callback != null) {
callback.handleUnparsablePacket(message);
}
// The parser is now at the end tag of the unparsable stanza. We need to advance to the next
// start tag in order to avoid an exception which would again lead to the execution of the
// catch block becoming effectively an endless loop.
eventType = parser.next();
continue;
}
connection.processPacket(iq);
}
else if (parser.getName().equals("presence")) {
Presence presence;
try {
presence = PacketParserUtils.parsePresence(parser);
} catch (Exception e) {
String content = PacketParserUtils.parseContentDepth(parser, parserDepth);
UnparsablePacket message = new UnparsablePacket(content, e);
if (callback != null) {
callback.handleUnparsablePacket(message);
}
// The parser is now at the end tag of the unparsable stanza. We need to advance to the next
// start tag in order to avoid an exception which would again lead to the execution of the
// catch block becoming effectively an endless loop.
eventType = parser.next();
continue;
}
connection.processPacket(presence);
}
// 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
connection.connectionID = parser.getAttributeValue(i);
}
}
}
}
else if (parser.getName().equals("error")) {
throw new StreamErrorException(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.streamCompressionNegotiationDone();
}
else {
// SASL authentication has failed. The server may close the connection
// depending on the number of retries
final SASLFailure failure = PacketParserUtils.parseSASLFailure(parser);
connection.processPacket(failure);
connection.getSASLAuthentication().authenticationFailed(failure);
}
}
else if (parser.getName().equals("challenge")) {
// The server is challenging the SASL authentication made by the client
String challengeData = parser.nextText();
connection.processPacket(new Challenge(challengeData));
connection.getSASLAuthentication().challengeReceived(challengeData);
}
else if (parser.getName().equals("success")) {
connection.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())) {
synchronized(this) {
this.notify();
}
// Close the connection and notify connection listeners of the
// error.
connection.notifyConnectionError(e);
}
}
}
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.serverRequiresBinding();
}
// 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.serverSupportsSession();
}
else if (parser.getName().equals("ver")) {
if (parser.getNamespace().equals("urn:xmpp:features:rosterver")) {
connection.setRosterVersioningSupported();
}
}
else if (parser.getName().equals("compression")) {
// The server supports stream compression
connection.setAvailableCompressionMethods(PacketParserUtils.parseCompressionMethods(parser));
}
else if (parser.getName().equals("register")) {
connection.serverSupportsAccountCreation();
}
}
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 SecurityRequiredException();
}
}
// Release the lock after TLS has been negotiated or we are not interested in TLS. If the
// server announced TLS and we choose to use it, by sending 'starttls', which the server
// replied with 'proceed', the server is required to send a new stream features element that
// "MUST NOT include the STARTTLS feature" (RFC6120 5.4.3.3. 5.). We are therefore save to
// release the connection lock once either TLS is disabled or we received a features stanza
// without starttls.
if (!startTLSReceived || connection.getConfiguration().getSecurityMode() ==
ConnectionConfiguration.SecurityMode.disabled)
{
lastFeaturesParsed = true;
// This synchronized block prevents this thread from calling notify() before the other
// thread had called wait() (it would cause an Exception if wait() hadn't been called)
synchronized (this) {
notify();
}
}
}
}