/**
* $RCSfile$
* $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 org.jivesoftware.smack.ConnectionListener;
import org.jivesoftware.smack.PacketCollector;
import org.jivesoftware.smack.XMPPConnection;
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.packet.DataForm;
import org.jivesoftware.smackx.packet.StreamInitiation;
import java.net.URLConnection;
import java.util.*;
/**
* 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://www.jabber.org/jeps/jep-0096.html>JEP-0096: File Transfer</a>
*/
public class FileTransferNegotiator {
// Static
/**
* The XMPP namespace of the SOCKS5 bytestream
*/
public static final String BYTE_STREAM = "http://jabber.org/protocol/bytestreams";
/**
* The XMPP namespace of the In-Band bytestream
*/
public static final String INBAND_BYTE_STREAM = "http://jabber.org/protocol/ibb";
private static final String[] NAMESPACE = {
"http://jabber.org/protocol/si/profile/file-transfer",
"http://jabber.org/protocol/si", BYTE_STREAM, INBAND_BYTE_STREAM};
private static final String[] PROTOCOLS = {BYTE_STREAM, INBAND_BYTE_STREAM};
private static final Map transferObject = new HashMap();
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();
public static boolean IBB_ONLY = false;
/**
* 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 XMPPConnection connection) {
if (connection == null) {
throw new IllegalArgumentException("Connection cannot be null");
}
if (!connection.isConnected()) {
return null;
}
if (transferObject.containsKey(connection)) {
return (FileTransferNegotiator) transferObject.get(connection);
}
else {
FileTransferNegotiator transfer = new FileTransferNegotiator(
connection);
setServiceEnabled(connection, true);
transferObject.put(connection, transfer);
return transfer;
}
}
/**
* 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 XMPPConnection connection,
final boolean isEnabled) {
ServiceDiscoveryManager manager = ServiceDiscoveryManager
.getInstanceFor(connection);
for (int i = 0; i < NAMESPACE.length; i++) {
if (isEnabled) {
manager.addFeature(NAMESPACE[i]);
}
else {
manager.removeFeature(NAMESPACE[i]);
}
}
}
/**
* 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 XMPPConnection connection) {
for (int i = 0; i < NAMESPACE.length; i++) {
if (!ServiceDiscoveryManager.getInstanceFor(connection)
.includesFeature(NAMESPACE[i]))
return false;
}
return true;
}
/**
* A convience 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) {
IQ iqPacket = new IQ() {
public String getChildElementXML() {
return null;
}
};
iqPacket.setPacketID(ID);
iqPacket.setTo(to);
iqPacket.setFrom(from);
iqPacket.setType(type);
return iqPacket;
}
/**
* Returns a collection of the supported transfer protocols.
*
* @return Returns a collection of the supported transfer protocols.
*/
public static Collection getSupportedProtocols() {
return Collections.unmodifiableList(Arrays.asList(PROTOCOLS));
}
// non-static
private final XMPPConnection connection;
private final StreamNegotiator byteStreamTransferManager;
private final StreamNegotiator inbandTransferManager;
private FileTransferNegotiator(final XMPPConnection connection) {
configureConnection(connection);
this.connection = connection;
byteStreamTransferManager = new Socks5TransferNegotiator(connection);
inbandTransferManager = new IBBTransferNegotiator(connection);
}
private void configureConnection(final XMPPConnection connection) {
connection.addConnectionListener(new ConnectionListener() {
public void connectionClosed() {
cleanup(connection);
}
public void connectionClosedOnError(Exception e) {
cleanup(connection);
}
});
}
private void cleanup(final XMPPConnection connection) {
transferObject.remove(connection);
byteStreamTransferManager.cleanup();
inbandTransferManager.cleanup();
}
/**
* 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 {
StreamInitiation si = request.getStreamInitiation();
FormField streamMethodField = getStreamMethodField(si
.getFeatureNegotiationForm());
if (streamMethodField == null) {
String errorMessage = "No stream methods contained in packet.";
XMPPError error = new XMPPError(XMPPError.Condition.bad_request, errorMessage);
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 (XMPPException e) {
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;
}
private FormField getStreamMethodField(DataForm form) {
FormField field = null;
for (Iterator it = form.getFields(); it.hasNext();) {
field = (FormField) it.next();
if (field.getVariable().equals(STREAM_DATA_FIELD_NAME)) {
break;
}
field = null;
}
return field;
}
private StreamNegotiator getNegotiator(final FormField field)
throws XMPPException {
String variable;
boolean isByteStream = false;
boolean isIBB = false;
for (Iterator it = field.getOptions(); it.hasNext();) {
variable = ((FormField.Option) it.next()).getValue();
if (variable.equals(BYTE_STREAM) && !IBB_ONLY) {
isByteStream = true;
}
else if (variable.equals(INBAND_BYTE_STREAM)) {
isIBB = true;
}
}
if (!isByteStream && !isIBB) {
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)) {
return new FaultTolerantNegotiator(connection, byteStreamTransferManager, inbandTransferManager);
}
else if (isByteStream) {
return byteStreamTransferManager;
}
else {
return inbandTransferManager;
}
}
/**
* Reject a stream initiation request from a remote user.
*
* @param si The Stream Initiation request to reject.
*/
public void rejectStream(final StreamInitiation si) {
XMPPError error = new XMPPError(XMPPError.Condition.forbidden, "Offer Declined");
IQ iqPacket = createIQ(si.getPacketID(), si.getFrom(), si.getTo(),
IQ.Type.ERROR);
iqPacket.setError(error);
connection.sendPacket(iqPacket);
}
/**
* 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() {
StringBuilder buffer = new StringBuilder();
buffer.append(STREAM_INIT_PREFIX);
buffer.append(Math.abs(randomGenerator.nextLong()));
return buffer.toString();
}
/**
* 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 choosen 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 prefered 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 {
StreamInitiation si = new StreamInitiation();
si.setSesssionID(streamID);
si.setMimeType(URLConnection.guessContentTypeFromName(fileName));
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);
PacketCollector collector = connection
.createPacketCollector(new PacketIDFilter(si.getPacketID()));
connection.sendPacket(si);
Packet siResponse = collector.nextResult(responseTimeout);
collector.cancel();
if (siResponse instanceof IQ) {
IQ iqResponse = (IQ) siResponse;
if (iqResponse.getType().equals(IQ.Type.RESULT)) {
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;
}
}
private StreamNegotiator getOutgoingNegotiator(final FormField field)
throws XMPPException {
String variable;
boolean isByteStream = false;
boolean isIBB = false;
for (Iterator<String> it = field.getValues(); it.hasNext();) {
variable = it.next();
if (variable.equals(BYTE_STREAM) && !IBB_ONLY) {
isByteStream = true;
}
else if (variable.equals(INBAND_BYTE_STREAM)) {
isIBB = true;
}
}
if (!isByteStream && !isIBB) {
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 DataForm createDefaultInitiationForm() {
DataForm form = new DataForm(Form.TYPE_FORM);
FormField field = new FormField(STREAM_DATA_FIELD_NAME);
field.setType(FormField.TYPE_LIST_MULTI);
if (!IBB_ONLY) {
field.addOption(new FormField.Option(BYTE_STREAM));
}
field.addOption(new FormField.Option(INBAND_BYTE_STREAM));
form.addField(field);
return form;
}
}