001/**
002 *
003 * Copyright the original author or authors
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smackx.filetransfer;
018
019import java.io.IOException;
020import java.io.InputStream;
021import java.io.OutputStream;
022import java.io.PushbackInputStream;
023
024import org.jivesoftware.smack.SmackException;
025import org.jivesoftware.smack.SmackException.NoResponseException;
026import org.jivesoftware.smack.XMPPConnection;
027import org.jivesoftware.smack.XMPPException;
028import org.jivesoftware.smack.XMPPException.XMPPErrorException;
029import org.jivesoftware.smack.packet.Stanza;
030import org.jivesoftware.smackx.bytestreams.socks5.Socks5BytestreamManager;
031import org.jivesoftware.smackx.bytestreams.socks5.Socks5BytestreamRequest;
032import org.jivesoftware.smackx.bytestreams.socks5.Socks5BytestreamSession;
033import org.jivesoftware.smackx.bytestreams.socks5.packet.Bytestream;
034import org.jivesoftware.smackx.si.packet.StreamInitiation;
035
036/**
037 * Negotiates a SOCKS5 Bytestream to be used for file transfers. The implementation is based on the
038 * {@link Socks5BytestreamManager} and the {@link Socks5BytestreamRequest}.
039 * 
040 * @author Henning Staib
041 * @see <a href="http://xmpp.org/extensions/xep-0065.html">XEP-0065: SOCKS5 Bytestreams</a>
042 */
043public class Socks5TransferNegotiator extends StreamNegotiator {
044
045    private XMPPConnection connection;
046
047    private Socks5BytestreamManager manager;
048
049    Socks5TransferNegotiator(XMPPConnection connection) {
050        this.connection = connection;
051        this.manager = Socks5BytestreamManager.getBytestreamManager(this.connection);
052    }
053
054    @Override
055    public OutputStream createOutgoingStream(String streamID, String initiator, String target) throws NoResponseException, SmackException, XMPPException
056                    {
057        try {
058            return this.manager.establishSession(target, streamID).getOutputStream();
059        }
060        catch (IOException e) {
061            throw new SmackException("error establishing SOCKS5 Bytestream", e);
062        }
063        catch (InterruptedException e) {
064            throw new SmackException("error establishing SOCKS5 Bytestream", e);
065        }
066    }
067
068    @Override
069    public InputStream createIncomingStream(StreamInitiation initiation) throws XMPPErrorException,
070                    InterruptedException, SmackException {
071        /*
072         * SOCKS5 initiation listener must ignore next SOCKS5 Bytestream request with given session
073         * ID
074         */
075        this.manager.ignoreBytestreamRequestOnce(initiation.getSessionID());
076
077        Stanza streamInitiation = initiateIncomingStream(this.connection, initiation);
078        return negotiateIncomingStream(streamInitiation);
079    }
080
081    @Override
082    public void newStreamInitiation(String from, String streamID) {
083        /*
084         * this method is always called prior to #negotiateIncomingStream() so the SOCKS5
085         * InitiationListener must ignore the next SOCKS5 Bytestream request with the given session
086         * ID
087         */
088        this.manager.ignoreBytestreamRequestOnce(streamID);
089    }
090
091    @Override
092    public String[] getNamespaces() {
093        return new String[] { Bytestream.NAMESPACE };
094    }
095
096    @Override
097    InputStream negotiateIncomingStream(Stanza streamInitiation) throws InterruptedException,
098                    SmackException, XMPPErrorException {
099        // build SOCKS5 Bytestream request
100        Socks5BytestreamRequest request = new ByteStreamRequest(this.manager,
101                        (Bytestream) streamInitiation);
102
103        // always accept the request
104        Socks5BytestreamSession session = request.accept();
105
106        // test input stream
107        try {
108            PushbackInputStream stream = new PushbackInputStream(session.getInputStream());
109            int firstByte = stream.read();
110            stream.unread(firstByte);
111            return stream;
112        }
113        catch (IOException e) {
114            throw new SmackException("Error establishing input stream", e);
115        }
116    }
117
118    /**
119     * Derive from Socks5BytestreamRequest to access protected constructor.
120     */
121    private static class ByteStreamRequest extends Socks5BytestreamRequest {
122
123        private ByteStreamRequest(Socks5BytestreamManager manager, Bytestream byteStreamRequest) {
124            super(manager, byteStreamRequest);
125        }
126
127    }
128
129}