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.XMPPConnection;
026import org.jivesoftware.smack.XMPPException;
027import org.jivesoftware.smack.XMPPException.XMPPErrorException;
028import org.jivesoftware.smack.packet.Stanza;
029
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
036import org.jxmpp.jid.Jid;
037
038/**
039 * Negotiates a SOCKS5 Bytestream to be used for file transfers. The implementation is based on the
040 * {@link Socks5BytestreamManager} and the {@link Socks5BytestreamRequest}.
041 *
042 * @author Henning Staib
043 * @see <a href="http://xmpp.org/extensions/xep-0065.html">XEP-0065: SOCKS5 Bytestreams</a>
044 */
045public class Socks5TransferNegotiator extends StreamNegotiator {
046
047    private final Socks5BytestreamManager manager;
048
049    Socks5TransferNegotiator(XMPPConnection connection) {
050        super(connection);
051        this.manager = Socks5BytestreamManager.getBytestreamManager(connection);
052    }
053
054    @Override
055    public OutputStream createOutgoingStream(String streamID, Jid initiator, Jid target) throws SmackException, XMPPException {
056        try {
057            return this.manager.establishSession(target, streamID).getOutputStream();
058        }
059        catch (IOException e) {
060            throw new SmackException.SmackWrappedException("error establishing SOCKS5 Bytestream", e);
061        }
062        catch (InterruptedException e) {
063            throw new SmackException.SmackWrappedException("error establishing SOCKS5 Bytestream", e);
064        }
065    }
066
067    @Override
068    public InputStream createIncomingStream(StreamInitiation initiation) throws XMPPErrorException,
069                    InterruptedException, SmackException {
070        /*
071         * SOCKS5 initiation listener must ignore next SOCKS5 Bytestream request with given session
072         * ID
073         */
074        this.manager.ignoreBytestreamRequestOnce(initiation.getSessionID());
075
076        Stanza streamInitiation = initiateIncomingStream(connection(), initiation);
077        return negotiateIncomingStream(streamInitiation);
078    }
079
080    @Override
081    public void newStreamInitiation(final Jid from, String streamID) {
082        /*
083         * this method is always called prior to #negotiateIncomingStream() so the SOCKS5
084         * InitiationListener must ignore the next SOCKS5 Bytestream request with the given session
085         * ID
086         */
087        this.manager.ignoreBytestreamRequestOnce(streamID);
088    }
089
090    @Override
091    public String getNamespace() {
092        return Bytestream.NAMESPACE;
093    }
094
095    @Override
096    InputStream negotiateIncomingStream(Stanza streamInitiation) throws InterruptedException,
097                    SmackException, XMPPErrorException {
098        // build SOCKS5 Bytestream request
099        Socks5BytestreamRequest request = new ByteStreamRequest(this.manager,
100                        (Bytestream) streamInitiation);
101
102        // always accept the request
103        Socks5BytestreamSession session = request.accept();
104
105        // test input stream
106        try {
107            PushbackInputStream stream = new PushbackInputStream(session.getInputStream());
108            int firstByte = stream.read();
109            stream.unread(firstByte);
110            return stream;
111        }
112        catch (IOException e) {
113            throw new SmackException.SmackWrappedException("Error establishing input stream", e);
114        }
115    }
116
117    /**
118     * Derive from Socks5BytestreamRequest to access protected constructor.
119     */
120    private static final class ByteStreamRequest extends Socks5BytestreamRequest {
121
122        private ByteStreamRequest(Socks5BytestreamManager manager, Bytestream byteStreamRequest) {
123            super(manager, byteStreamRequest);
124        }
125
126    }
127
128}