/**
* $RCSfile$
* $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.PacketCollector;
import org.jivesoftware.smack.SmackConfiguration;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.filter.AndFilter;
import org.jivesoftware.smack.filter.FromMatchesFilter;
import org.jivesoftware.smack.filter.PacketFilter;
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.smack.util.StringUtils;
import org.jivesoftware.smack.util.Cache;
import org.jivesoftware.smackx.ServiceDiscoveryManager;
import org.jivesoftware.smackx.packet.Bytestream;
import org.jivesoftware.smackx.packet.Bytestream.StreamHost;
import org.jivesoftware.smackx.packet.Bytestream.StreamHostUsed;
import org.jivesoftware.smackx.packet.DiscoverInfo;
import org.jivesoftware.smackx.packet.DiscoverInfo.Identity;
import org.jivesoftware.smackx.packet.DiscoverItems;
import org.jivesoftware.smackx.packet.DiscoverItems.Item;
import org.jivesoftware.smackx.packet.StreamInitiation;
import java.io.*;
import java.net.*;
import java.util.*;
/**
* A SOCKS5 bytestream is negotiated partly over the XMPP XML stream and partly
* over a seperate socket. The actual transfer though takes place over a
* seperatly created socket.
*
* A SOCKS5 file transfer generally has three parites, the initiator, the
* target, and the stream host. The stream host is a specialized SOCKS5 proxy
* setup on the server, or, the Initiator can act as the Stream Host if the
* proxy is not available.
*
* The advantage of having a seperate proxy over directly connecting to
* eachother is if the Initator and the Target are not on the same LAN and are
* operating behind NAT, the proxy allows for a common location for both parties
* to connect to and transfer the file.
*
* Smack will attempt to automatically discover any proxies present on your
* server. If any are detected they will be forwarded to any user attempting to
* recieve files from you.
*
* @author Alexander Wenckus
* @see JEP-0065: SOCKS5
* Bytestreams
*/
public class Socks5TransferNegotiator extends StreamNegotiator {
protected static final String NAMESPACE = "http://jabber.org/protocol/bytestreams";
/**
* The number of connection failures it takes to a streamhost for that particular streamhost
* to be blacklisted. When a host is blacklisted no more connection attempts will be made to
* it for a period of 2 hours.
*/
private static final int CONNECT_FAILURE_THRESHOLD = 2;
private static final long BLACKLIST_LIFETIME = 60 * 1000 * 120;
public static boolean isAllowLocalProxyHost = true;
private final XMPPConnection connection;
private List proxies;
private List streamHosts;
// locks the proxies during their initialization process
private final Object proxyLock = new Object();
private ProxyProcess proxyProcess;
// locks on the proxy process during its initiatilization process
private final Object processLock = new Object();
private final Cache addressBlacklist = new Cache(100, BLACKLIST_LIFETIME);
public Socks5TransferNegotiator(final XMPPConnection connection) {
this.connection = connection;
}
public PacketFilter getInitiationPacketFilter(String from, String sessionID) {
return new AndFilter(new FromMatchesFilter(from),
new BytestreamSIDFilter(sessionID));
}
/*
* (non-Javadoc)
*
* @see org.jivesoftware.smackx.filetransfer.StreamNegotiator#initiateDownload(
* org.jivesoftware.smackx.packet.StreamInitiation, java.io.File)
*/
InputStream negotiateIncomingStream(Packet streamInitiation)
throws XMPPException {
Bytestream streamHostsInfo = (Bytestream) streamInitiation;
if (streamHostsInfo.getType().equals(IQ.Type.ERROR)) {
throw new XMPPException(streamHostsInfo.getError());
}
SelectedHostInfo selectedHost;
try {
// select appropriate host
selectedHost = selectHost(streamHostsInfo);
}
catch (XMPPException ex) {
if (ex.getXMPPError() != null) {
IQ errorPacket = super.createError(streamHostsInfo.getTo(),
streamHostsInfo.getFrom(), streamHostsInfo.getPacketID(),
ex.getXMPPError());
connection.sendPacket(errorPacket);
}
throw(ex);
}
// send used-host confirmation
Bytestream streamResponse = createUsedHostConfirmation(
selectedHost.selectedHost, streamHostsInfo.getFrom(),
streamHostsInfo.getTo(), streamHostsInfo.getPacketID());
connection.sendPacket(streamResponse);
try {
return selectedHost.establishedSocket.getInputStream();
}
catch (IOException e) {
throw new XMPPException("Error establishing input stream", e);
}
}
public InputStream createIncomingStream(StreamInitiation initiation) throws XMPPException {
Packet streamInitiation = initiateIncomingStream(connection, initiation);
return negotiateIncomingStream(streamInitiation);
}
/**
* The used host confirmation is sent to the initiator to indicate to them
* which of the hosts they provided has been selected and successfully
* connected to.
*
* @param selectedHost The selected stream host.
* @param initiator The initiator of the stream.
* @param target The target of the stream.
* @param packetID The of the packet being responded to.
* @return The packet that was created to send to the initiator.
*/
private Bytestream createUsedHostConfirmation(StreamHost selectedHost,
String initiator, String target, String packetID) {
Bytestream streamResponse = new Bytestream();
streamResponse.setTo(initiator);
streamResponse.setFrom(target);
streamResponse.setType(IQ.Type.RESULT);
streamResponse.setPacketID(packetID);
streamResponse.setUsedHost(selectedHost.getJID());
return streamResponse;
}
/**
* Selects a host to connect to over which the file will be transmitted.
*
* @param streamHostsInfo the packet recieved from the initiator containing the available hosts
* to transfer the file
* @return the selected host and socket that were created.
* @throws XMPPException when there is no appropriate host.
*/
private SelectedHostInfo selectHost(Bytestream streamHostsInfo)
throws XMPPException
{
Iterator it = streamHostsInfo.getStreamHosts().iterator();
StreamHost selectedHost = null;
Socket socket = null;
while (it.hasNext()) {
selectedHost = (StreamHost) it.next();
String address = selectedHost.getAddress();
// Check to see if this address has been blacklisted
int failures = getConnectionFailures(address);
if(failures >= CONNECT_FAILURE_THRESHOLD) {
continue;
}
// establish socket
try {
socket = new Socket(address, selectedHost
.getPort());
establishSOCKS5ConnectionToProxy(socket, createDigest(
streamHostsInfo.getSessionID(), streamHostsInfo
.getFrom(), streamHostsInfo.getTo()));
break;
}
catch (IOException e) {
e.printStackTrace();
incrementConnectionFailures(address);
selectedHost = null;
socket = null;
}
}
if (selectedHost == null || socket == null || !socket.isConnected()) {
throw new XMPPException(
"Could not establish socket with any provided host", new XMPPError(406));
}
return new SelectedHostInfo(selectedHost, socket);
}
private void incrementConnectionFailures(String address) {
Integer count = (Integer) addressBlacklist.get(address);
if(count == null) {
count = new Integer(1);
}
else {
count = new Integer(count.intValue() + 1);
}
addressBlacklist.put(address, count);
}
private int getConnectionFailures(String address) {
Integer count = (Integer) addressBlacklist.get(address);
return (count != null ? count.intValue() : 0);
}
/**
* Creates the digest needed for a byte stream. It is the SHA1(sessionID +
* initiator + target).
*
* @param sessionID The sessionID of the stream negotiation
* @param initiator The inititator of the stream negotiation
* @param target The target of the stream negotiation
* @return SHA-1 hash of the three parameters
*/
private String createDigest(final String sessionID, final String initiator,
final String target) {
return StringUtils.hash(sessionID + StringUtils.parseName(initiator)
+ "@" + StringUtils.parseServer(initiator) + "/"
+ StringUtils.parseResource(initiator)
+ StringUtils.parseName(target) + "@"
+ StringUtils.parseServer(target) + "/"
+ StringUtils.parseResource(target));
}
/*
* (non-Javadoc)
*
* @see org.jivesoftware.smackx.filetransfer.StreamNegotiator#initiateUpload(java.lang.String,
* org.jivesoftware.smackx.packet.StreamInitiation, java.io.File)
*/
public OutputStream createOutgoingStream(String streamID, String initiator,
String target) throws XMPPException
{
Socket socket;
try {
socket = initBytestreamSocket(streamID, initiator, target);
}
catch (Exception e) {
throw new XMPPException("Error establishing transfer socket", e);
}
if (socket != null) {
try {
return new BufferedOutputStream(socket.getOutputStream());
}
catch (IOException e) {
throw new XMPPException("Error establishing output stream", e);
}
}
return null;
}
private Socket initBytestreamSocket(final String sessionID,
String initiator, String target) throws Exception
{
ProxyProcess process;
try {
process = establishListeningSocket();
}
catch (IOException io) {
process = null;
}
String localIP;
try {
localIP = discoverLocalIP();
}
catch (UnknownHostException e1) {
localIP = null;
}
Bytestream query = createByteStreamInit(initiator, target, sessionID,
localIP, (process != null ? process.getPort() : 0));
// if the local host is one of the options we need to wait for the
// remote connection.
Socket conn = waitForUsedHostResponse(sessionID, process, createDigest(
sessionID, initiator, target), query).establishedSocket;
cleanupListeningSocket();
return conn;
}
/**
* Waits for the peer to respond with which host they chose to use.
*
* @param sessionID The session id of the stream.
* @param proxy The server socket which will listen locally for remote
* connections.
* @param digest
* @param query
* @return
* @throws XMPPException
* @throws IOException
*/
private SelectedHostInfo waitForUsedHostResponse(String sessionID,
final ProxyProcess proxy, final String digest,
final Bytestream query) throws XMPPException, IOException
{
SelectedHostInfo info = new SelectedHostInfo();
PacketCollector collector = connection
.createPacketCollector(new PacketIDFilter(query.getPacketID()));
connection.sendPacket(query);
Packet packet = collector.nextResult();
collector.cancel();
Bytestream response;
if (packet instanceof Bytestream) {
response = (Bytestream) packet;
}
else {
throw new XMPPException("Unexpected response from remote user");
}
// check for an error
if (response.getType().equals(IQ.Type.ERROR)) {
throw new XMPPException("Remote client returned error, stream hosts expected",
response.getError());
}
StreamHostUsed used = response.getUsedHost();
StreamHost usedHost = query.getStreamHost(used.getJID());
if (usedHost == null) {
throw new XMPPException("Remote user responded with unknown host");
}
// The local computer is acting as the proxy
if (used.getJID().equals(query.getFrom())) {
info.establishedSocket = proxy.getSocket(digest);
info.selectedHost = usedHost;
return info;
}
else {
info.establishedSocket = new Socket(usedHost.getAddress(), usedHost
.getPort());
establishSOCKS5ConnectionToProxy(info.establishedSocket, digest);
Bytestream activate = createByteStreamActivate(sessionID, response
.getTo(), usedHost.getJID(), response.getFrom());
collector = connection.createPacketCollector(new PacketIDFilter(
activate.getPacketID()));
connection.sendPacket(activate);
IQ serverResponse = (IQ) collector.nextResult(SmackConfiguration
.getPacketReplyTimeout());
collector.cancel();
if (!serverResponse.getType().equals(IQ.Type.RESULT)) {
info.establishedSocket.close();
return null;
}
return info;
}
}
private ProxyProcess establishListeningSocket() throws IOException {
synchronized (processLock) {
if (proxyProcess == null) {
proxyProcess = new ProxyProcess(new ServerSocket(7777));
proxyProcess.start();
}
}
proxyProcess.addTransfer();
return proxyProcess;
}
private void cleanupListeningSocket() {
if (proxyProcess == null) {
return;
}
proxyProcess.removeTransfer();
}
private String discoverLocalIP() throws UnknownHostException {
return InetAddress.getLocalHost().getHostAddress();
}
/**
* The bytestream init looks like this:
*
*
* <iq type='set'
* from='initiator@host1/foo'
* to='target@host2/bar'
* id='initiate'>
* <query xmlns='http://jabber.org/protocol/bytestreams'
* sid='mySID'
* mode='tcp'>
* <streamhost
* jid='initiator@host1/foo'
* host='192.168.4.1'
* port='5086'/>
* <streamhost
* jid='proxy.host3'
* host='24.24.24.1'
* zeroconf='_jabber.bytestreams'/>
* </query>
* </iq>
*
*
* @param from initiator@host1/foo - the file transfer initiator.
* @param to target@host2/bar - the file transfer target.
* @param sid 'mySID' - the unique identifier for this file transfer
* @param localIP the IP of the local machine if it is being provided, null otherwise.
* @param port the port of the local mahine if it is being provided, null otherwise.
* @return the created Bytestream packet
*/
private Bytestream createByteStreamInit(final String from, final String to,
final String sid, final String localIP, final int port) {
Bytestream bs = new Bytestream();
bs.setTo(to);
bs.setFrom(from);
bs.setSessionID(sid);
bs.setType(IQ.Type.SET);
bs.setMode(Bytestream.Mode.TCP);
if (localIP != null && port > 0) {
bs.addStreamHost(from, localIP, port);
}
// make sure the proxies have been initialized completely
synchronized (proxyLock) {
if (proxies == null) {
initProxies();
}
}
if (streamHosts != null) {
Iterator it = streamHosts.iterator();
while (it.hasNext()) {
bs.addStreamHost((StreamHost) it.next());
}
}
return bs;
}
private void initProxies() {
proxies = new ArrayList();
ServiceDiscoveryManager manager = ServiceDiscoveryManager
.getInstanceFor(connection);
DiscoverItems discoItems;
try {
discoItems = manager.discoverItems(connection.getServiceName());
DiscoverItems.Item item;
DiscoverInfo info;
DiscoverInfo.Identity identity;
Iterator it = discoItems.getItems();
while (it.hasNext()) {
item = (Item) it.next();
info = manager.discoverInfo(item.getEntityID());
Iterator itx = info.getIdentities();
while (itx.hasNext()) {
identity = (Identity) itx.next();
if (identity.getCategory().equalsIgnoreCase("proxy")
&& identity.getType().equalsIgnoreCase(
"bytestreams")) {
proxies.add(info.getFrom());
}
}
}
}
catch (XMPPException e) {
return;
}
if (proxies.size() > 0) {
initStreamHosts();
}
}
private void initStreamHosts() {
List streamHosts = new ArrayList();
Iterator it = proxies.iterator();
IQ query;
PacketCollector collector;
Bytestream response;
while (it.hasNext()) {
String jid = it.next().toString();
query = new IQ() {
public String getChildElementXML() {
return "";
}
};
query.setType(IQ.Type.GET);
query.setTo(jid);
collector = connection.createPacketCollector(new PacketIDFilter(
query.getPacketID()));
connection.sendPacket(query);
response = (Bytestream) collector.nextResult(SmackConfiguration
.getPacketReplyTimeout());
if (response != null) {
streamHosts.addAll(response.getStreamHosts());
}
collector.cancel();
}
this.streamHosts = streamHosts;
}
/**
* Returns the packet to send notification to the stream host to activate
* the stream.
*
* @param sessionID the session ID of the file transfer to activate.
* @param from
* @param to the JID of the stream host
* @param target the JID of the file transfer target.
* @return the packet to send notification to the stream host to
* activate the stream.
*/
private static Bytestream createByteStreamActivate(final String sessionID,
final String from, final String to, final String target) {
Bytestream activate = new Bytestream(sessionID);
activate.setMode(null);
activate.setToActivate(target);
activate.setFrom(from);
activate.setTo(to);
activate.setType(IQ.Type.SET);
return activate;
}
/**
* Negotiates the Socks 5 bytestream when the local computer is acting as
* the proxy.
*
* @param connection the socket connection with the peer.
* @return the SHA-1 digest that is used to uniquely identify the file
* transfer.
* @throws XMPPException
* @throws IOException
*/
private String establishSocks5UploadConnection(Socket connection) throws XMPPException, IOException {
OutputStream out = new DataOutputStream(connection.getOutputStream());
InputStream in = new DataInputStream(connection.getInputStream());
// first byte is version should be 5
int b = in.read();
if (b != 5) {
throw new XMPPException("Only SOCKS5 supported");
}
// second byte number of authentication methods supported
b = in.read();
int[] auth = new int[b];
for (int i = 0; i < b; i++) {
auth[i] = in.read();
}
int authMethod = -1;
for (int i = 0; i < auth.length; i++) {
authMethod = (auth[i] == 0 ? 0 : -1); // only auth method
// 0, no
// authentication,
// supported
if (authMethod == 0) {
break;
}
}
if (authMethod != 0) {
throw new XMPPException("Authentication method not supported");
}
byte[] cmd = new byte[2];
cmd[0] = (byte) 0x05;
cmd[1] = (byte) 0x00;
out.write(cmd);
String responseDigest = createIncomingSocks5Message(in);
cmd = createOutgoingSocks5Message(0, responseDigest);
if (!connection.isConnected()) {
throw new XMPPException("Socket closed by remote user");
}
out.write(cmd);
return responseDigest;
}
public String[] getNamespaces() {
return new String[]{NAMESPACE};
}
private void establishSOCKS5ConnectionToProxy(Socket socket, String digest)
throws IOException {
byte[] cmd = new byte[3];
cmd[0] = (byte) 0x05;
cmd[1] = (byte) 0x01;
cmd[2] = (byte) 0x00;
OutputStream out = new DataOutputStream(socket.getOutputStream());
out.write(cmd);
InputStream in = new DataInputStream(socket.getInputStream());
byte[] response = new byte[2];
in.read(response);
cmd = createOutgoingSocks5Message(1, digest);
out.write(cmd);
createIncomingSocks5Message(in);
}
private String createIncomingSocks5Message(InputStream in)
throws IOException {
byte[] cmd = new byte[5];
in.read(cmd, 0, 5);
byte[] addr = new byte[cmd[4]];
in.read(addr, 0, addr.length);
String digest = new String(addr);
in.read();
in.read();
return digest;
}
private byte[] createOutgoingSocks5Message(int cmd, String digest) {
byte addr[] = digest.getBytes();
byte[] data = new byte[7 + addr.length];
data[0] = (byte) 5;
data[1] = (byte) cmd;
data[2] = (byte) 0;
data[3] = (byte) 0x3;
data[4] = (byte) addr.length;
System.arraycopy(addr, 0, data, 5, addr.length);
data[data.length - 2] = (byte) 0;
data[data.length - 1] = (byte) 0;
return data;
}
public void cleanup() {
synchronized (processLock) {
if (proxyProcess != null) {
proxyProcess.stop();
}
}
}
public void cancel() {
}
private static class SelectedHostInfo {
protected XMPPException exception;
protected StreamHost selectedHost;
protected Socket establishedSocket;
SelectedHostInfo(StreamHost selectedHost, Socket establishedSocket) {
this.selectedHost = selectedHost;
this.establishedSocket = establishedSocket;
}
public SelectedHostInfo() {
}
}
private class ProxyProcess implements Runnable {
private final ServerSocket listeningSocket;
private final Map connectionMap = new HashMap();
private boolean done = false;
private Thread thread;
private int transfers;
public void run() {
try {
try {
listeningSocket.setSoTimeout(10000);
}
catch (SocketException e) {
// There was a TCP error, lets print the stack trace
e.printStackTrace();
return;
}
while (!done) {
Socket conn = null;
synchronized (ProxyProcess.this) {
while (transfers <= 0 && !done) {
transfers = -1;
try {
ProxyProcess.this.wait();
}
catch (InterruptedException e) {
/* Do nothing */
}
}
}
if(done) {
break;
}
try {
synchronized (listeningSocket) {
conn = listeningSocket.accept();
}
if (conn == null) {
continue;
}
String digest = establishSocks5UploadConnection(conn);
synchronized (connectionMap) {
connectionMap.put(digest, conn);
}
}
catch (SocketTimeoutException e) {
/* Do Nothing */
}
catch (IOException e) {
/* Do Nothing */
}
catch (XMPPException e) {
e.printStackTrace();
if (conn != null) {
try {
conn.close();
}
catch (IOException e1) {
/* Do Nothing */
}
}
}
}
}
finally {
try {
listeningSocket.close();
}
catch (IOException e) {
/* Do Nothing */
}
}
}
public void start() {
thread.start();
}
public void stop() {
done = true;
synchronized (this) {
this.notify();
}
synchronized (listeningSocket) {
listeningSocket.notify();
}
}
public int getPort() {
return listeningSocket.getLocalPort();
}
ProxyProcess(ServerSocket listeningSocket) {
thread = new Thread(this, "File Transfer Connection Listener");
this.listeningSocket = listeningSocket;
}
public Socket getSocket(String digest) {
synchronized (connectionMap) {
return (Socket) connectionMap.get(digest);
}
}
public void addTransfer() {
synchronized (this) {
if (transfers == -1) {
transfers = 1;
this.notify();
}
else {
transfers++;
}
}
}
public void removeTransfer() {
synchronized (this) {
transfers--;
}
}
}
private static class BytestreamSIDFilter implements PacketFilter {
private String sessionID;
public BytestreamSIDFilter(String sessionID) {
if (sessionID == null) {
throw new IllegalArgumentException("StreamID cannot be null");
}
this.sessionID = sessionID;
}
public boolean accept(Packet packet) {
if (!Bytestream.class.isInstance(packet)) {
return false;
}
Bytestream bytestream = (Bytestream) packet;
String sessionID = bytestream.getSessionID();
return (sessionID != null && sessionID.equals(this.sessionID));
}
}
}