/**
* $RCSfile$
* $Revision: $
* $Date: $
*
* Copyright 2003-2006 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.smackx.filetransfer;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.concurrent.ConcurrentHashMap;
import org.jivesoftware.smack.Connection;
import org.jivesoftware.smack.ConnectionListener;
import org.jivesoftware.smack.PacketCollector;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.filter.PacketIDFilter;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.Packet;
import org.jivesoftware.smack.packet.XMPPError;
import org.jivesoftware.smackx.Form;
import org.jivesoftware.smackx.FormField;
import org.jivesoftware.smackx.ServiceDiscoveryManager;
import org.jivesoftware.smackx.bytestreams.ibb.InBandBytestreamManager;
import org.jivesoftware.smackx.bytestreams.socks5.Socks5BytestreamManager;
import org.jivesoftware.smackx.packet.DataForm;
import org.jivesoftware.smackx.packet.StreamInitiation;
/**
* Manages the negotiation of file transfers according to JEP-0096. If a file is
* being sent the remote user chooses the type of stream under which the file
* will be sent.
*
* @author Alexander Wenckus
* @see <a href="http://xmpp.org/extensions/xep-0096.html">XEP-0096: SI File
* Transfer</a>
*/
public class FileTransferNegotiator {
// Static
private static final String[] NAMESPACE = {
"http://jabber.org/protocol/si/profile/file-transfer",
"http://jabber.org/protocol/si" };
private static final Map<Connection, FileTransferNegotiator> transferObject = new ConcurrentHashMap<Connection, FileTransferNegotiator>();
private static final String STREAM_INIT_PREFIX = "jsi_";
protected static final String STREAM_DATA_FIELD_NAME = "stream-method";
private static final Random randomGenerator = new Random();
/**
* A static variable to use only offer IBB for file transfer. It is
* generally recommend to only set this variable to true for testing
* purposes as IBB is the backup file transfer method and shouldn't be used
* as the only transfer method in production systems.
*/
public static boolean IBB_ONLY = (System.getProperty("ibb") != null);// true;
/**
* A convenience method to create an IQ packet.
*
* @param ID
* The packet ID of the
* @param to
* To whom the packet is addressed.
* @param from
* From whom the packet is sent.
* @param type
* The IQ type of the packet.
* @return The created IQ packet.
*/
public static IQ createIQ(final String ID, final String to,
final String from, final IQ.Type type) {
final IQ iqPacket = new IQ() {
@Override
public String getChildElementXML() {
return null;
}
};
iqPacket.setPacketID(ID);
iqPacket.setTo(to);
iqPacket.setFrom(from);
iqPacket.setType(type);
return iqPacket;
}
/**
* Returns the file transfer negotiator related to a particular connection.
* When this class is requested on a particular connection the file transfer
* service is automatically enabled.
*
* @param connection
* The connection for which the transfer manager is desired
* @return The IMFileTransferManager
*/
public static FileTransferNegotiator getInstanceFor(
final Connection connection) {
if (connection == null) {
throw new IllegalArgumentException("Connection cannot be null");
}
if (!connection.isConnected()) {
return null;
}
if (transferObject.containsKey(connection)) {
return transferObject.get(connection);
} else {
final FileTransferNegotiator transfer = new FileTransferNegotiator(
connection);
setServiceEnabled(connection, true);
transferObject.put(connection, transfer);
return transfer;
}
}
/**
* Returns a collection of the supported transfer protocols.
*
* @return Returns a collection of the supported transfer protocols.
*/
public static Collection<String> getSupportedProtocols() {
final List<String> protocols = new ArrayList<String>();
protocols.add(InBandBytestreamManager.NAMESPACE);
if (!IBB_ONLY) {
protocols.add(Socks5BytestreamManager.NAMESPACE);
}
return Collections.unmodifiableList(protocols);
}
/**
* Checks to see if all file transfer related services are enabled on the
* connection.
*
* @param connection
* The connection to check
* @return True if all related services are enabled, false if they are not.
*/
public static boolean isServiceEnabled(final Connection connection) {
final ServiceDiscoveryManager manager = ServiceDiscoveryManager
.getInstanceFor(connection);
final List<String> namespaces = new ArrayList<String>();
namespaces.addAll(Arrays.asList(NAMESPACE));
namespaces.add(InBandBytestreamManager.NAMESPACE);
if (!IBB_ONLY) {
namespaces.add(Socks5BytestreamManager.NAMESPACE);
}
for (final String namespace : namespaces) {
if (!manager.includesFeature(namespace)) {
return false;
}
}
return true;
}
/**
* Enable the Jabber services related to file transfer on the particular
* connection.
*
* @param connection
* The connection on which to enable or disable the services.
* @param isEnabled
* True to enable, false to disable.
*/
public static void setServiceEnabled(final Connection connection,
final boolean isEnabled) {
final ServiceDiscoveryManager manager = ServiceDiscoveryManager
.getInstanceFor(connection);
final List<String> namespaces = new ArrayList<String>();
namespaces.addAll(Arrays.asList(NAMESPACE));
namespaces.add(InBandBytestreamManager.NAMESPACE);
if (!IBB_ONLY) {
namespaces.add(Socks5BytestreamManager.NAMESPACE);
}
for (final String namespace : namespaces) {
if (isEnabled) {
if (!manager.includesFeature(namespace)) {
manager.addFeature(namespace);
}
} else {
manager.removeFeature(namespace);
}
}
}
// non-static
private final Connection connection;
private final StreamNegotiator byteStreamTransferManager;
private final StreamNegotiator inbandTransferManager;
private FileTransferNegotiator(final Connection connection) {
configureConnection(connection);
this.connection = connection;
byteStreamTransferManager = new Socks5TransferNegotiator(connection);
inbandTransferManager = new IBBTransferNegotiator(connection);
}
private void cleanup(final Connection connection) {
if (transferObject.remove(connection) != null) {
inbandTransferManager.cleanup();
}
}
private void configureConnection(final Connection connection) {
connection.addConnectionListener(new ConnectionListener() {
@Override
public void connectionClosed() {
cleanup(connection);
}
@Override
public void connectionClosedOnError(Exception e) {
cleanup(connection);
}
@Override
public void reconnectingIn(int seconds) {
// ignore
}
@Override
public void reconnectionFailed(Exception e) {
// ignore
}
@Override
public void reconnectionSuccessful() {
// ignore
}
});
}
private DataForm createDefaultInitiationForm() {
final DataForm form = new DataForm(Form.TYPE_FORM);
final FormField field = new FormField(STREAM_DATA_FIELD_NAME);
field.setType(FormField.TYPE_LIST_SINGLE);
if (!IBB_ONLY) {
field.addOption(new FormField.Option(
Socks5BytestreamManager.NAMESPACE));
}
field.addOption(new FormField.Option(InBandBytestreamManager.NAMESPACE));
form.addField(field);
return form;
}
private StreamNegotiator getNegotiator(final FormField field)
throws XMPPException {
String variable;
boolean isByteStream = false;
boolean isIBB = false;
for (final Iterator<FormField.Option> it = field.getOptions(); it
.hasNext();) {
variable = it.next().getValue();
if (variable.equals(Socks5BytestreamManager.NAMESPACE) && !IBB_ONLY) {
isByteStream = true;
} else if (variable.equals(InBandBytestreamManager.NAMESPACE)) {
isIBB = true;
}
}
if (!isByteStream && !isIBB) {
final XMPPError error = new XMPPError(
XMPPError.Condition.bad_request,
"No acceptable transfer mechanism");
throw new XMPPException(error.getMessage(), error);
}
// if (isByteStream && isIBB &&
// field.getType().equals(FormField.TYPE_LIST_MULTI)) {
if (isByteStream && isIBB) {
return new FaultTolerantNegotiator(connection,
byteStreamTransferManager, inbandTransferManager);
} else if (isByteStream) {
return byteStreamTransferManager;
} else {
return inbandTransferManager;
}
}
/**
* Returns a new, unique, stream ID to identify a file transfer.
*
* @return Returns a new, unique, stream ID to identify a file transfer.
*/
public String getNextStreamID() {
final StringBuilder buffer = new StringBuilder();
buffer.append(STREAM_INIT_PREFIX);
buffer.append(Math.abs(randomGenerator.nextLong()));
return buffer.toString();
}
private StreamNegotiator getOutgoingNegotiator(final FormField field)
throws XMPPException {
String variable;
boolean isByteStream = false;
boolean isIBB = false;
for (final Iterator<String> it = field.getValues(); it.hasNext();) {
variable = it.next();
if (variable.equals(Socks5BytestreamManager.NAMESPACE) && !IBB_ONLY) {
isByteStream = true;
} else if (variable.equals(InBandBytestreamManager.NAMESPACE)) {
isIBB = true;
}
}
if (!isByteStream && !isIBB) {
final XMPPError error = new XMPPError(
XMPPError.Condition.bad_request,
"No acceptable transfer mechanism");
throw new XMPPException(error.getMessage(), error);
}
if (isByteStream && isIBB) {
return new FaultTolerantNegotiator(connection,
byteStreamTransferManager, inbandTransferManager);
} else if (isByteStream) {
return byteStreamTransferManager;
} else {
return inbandTransferManager;
}
}
private FormField getStreamMethodField(DataForm form) {
FormField field = null;
for (final Iterator<FormField> it = form.getFields(); it.hasNext();) {
field = it.next();
if (field.getVariable().equals(STREAM_DATA_FIELD_NAME)) {
break;
}
field = null;
}
return field;
}
/**
* Send a request to another user to send them a file. The other user has
* the option of, accepting, rejecting, or not responding to a received file
* transfer request.
* <p/>
* If they accept, the packet will contain the other user's chosen stream
* type to send the file across. The two choices this implementation
* provides to the other user for file transfer are <a
* href="http://www.jabber.org/jeps/jep-0065.html">SOCKS5 Bytestreams</a>,
* which is the preferred method of transfer, and <a
* href="http://www.jabber.org/jeps/jep-0047.html">In-Band Bytestreams</a>,
* which is the fallback mechanism.
* <p/>
* The other user may choose to decline the file request if they do not
* desire the file, their client does not support JEP-0096, or if there are
* no acceptable means to transfer the file.
* <p/>
* Finally, if the other user does not respond this method will return null
* after the specified timeout.
*
* @param userID
* The userID of the user to whom the file will be sent.
* @param streamID
* The unique identifier for this file transfer.
* @param fileName
* The name of this file. Preferably it should include an
* extension as it is used to determine what type of file it is.
* @param size
* The size, in bytes, of the file.
* @param desc
* A description of the file.
* @param responseTimeout
* The amount of time, in milliseconds, to wait for the remote
* user to respond. If they do not respond in time, this
* @return Returns the stream negotiator selected by the peer.
* @throws XMPPException
* Thrown if there is an error negotiating the file transfer.
*/
public StreamNegotiator negotiateOutgoingTransfer(final String userID,
final String streamID, final String fileName, final long size,
final String desc, int responseTimeout) throws XMPPException {
final StreamInitiation si = new StreamInitiation();
si.setSesssionID(streamID);
si.setMimeType(URLConnection.guessContentTypeFromName(fileName));
final StreamInitiation.File siFile = new StreamInitiation.File(
fileName, size);
siFile.setDesc(desc);
si.setFile(siFile);
si.setFeatureNegotiationForm(createDefaultInitiationForm());
si.setFrom(connection.getUser());
si.setTo(userID);
si.setType(IQ.Type.SET);
final PacketCollector collector = connection
.createPacketCollector(new PacketIDFilter(si.getPacketID()));
connection.sendPacket(si);
final Packet siResponse = collector.nextResult(responseTimeout);
collector.cancel();
if (siResponse instanceof IQ) {
final IQ iqResponse = (IQ) siResponse;
if (iqResponse.getType().equals(IQ.Type.RESULT)) {
final StreamInitiation response = (StreamInitiation) siResponse;
return getOutgoingNegotiator(getStreamMethodField(response
.getFeatureNegotiationForm()));
} else if (iqResponse.getType().equals(IQ.Type.ERROR)) {
throw new XMPPException(iqResponse.getError());
} else {
throw new XMPPException("File transfer response unreadable");
}
} else {
return null;
}
}
/**
* Reject a stream initiation request from a remote user.
*
* @param si
* The Stream Initiation request to reject.
*/
public void rejectStream(final StreamInitiation si) {
final XMPPError error = new XMPPError(XMPPError.Condition.forbidden,
"Offer Declined");
final IQ iqPacket = createIQ(si.getPacketID(), si.getFrom(),
si.getTo(), IQ.Type.ERROR);
iqPacket.setError(error);
connection.sendPacket(iqPacket);
}
/**
* Selects an appropriate stream negotiator after examining the incoming
* file transfer request.
*
* @param request
* The related file transfer request.
* @return The file transfer object that handles the transfer
* @throws XMPPException
* If there are either no stream methods contained in the
* packet, or there is not an appropriate stream method.
*/
public StreamNegotiator selectStreamNegotiator(FileTransferRequest request)
throws XMPPException {
final StreamInitiation si = request.getStreamInitiation();
final FormField streamMethodField = getStreamMethodField(si
.getFeatureNegotiationForm());
if (streamMethodField == null) {
final String errorMessage = "No stream methods contained in packet.";
final XMPPError error = new XMPPError(
XMPPError.Condition.bad_request, errorMessage);
final IQ iqPacket = createIQ(si.getPacketID(), si.getFrom(),
si.getTo(), IQ.Type.ERROR);
iqPacket.setError(error);
connection.sendPacket(iqPacket);
throw new XMPPException(errorMessage, error);
}
// select the appropriate protocol
StreamNegotiator selectedStreamNegotiator;
try {
selectedStreamNegotiator = getNegotiator(streamMethodField);
} catch (final XMPPException e) {
final IQ iqPacket = createIQ(si.getPacketID(), si.getFrom(),
si.getTo(), IQ.Type.ERROR);
iqPacket.setError(e.getXMPPError());
connection.sendPacket(iqPacket);
throw e;
}
// return the appropriate negotiator
return selectedStreamNegotiator;
}
}