org.eclipse.jetty.client.Socks4Proxy Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
// which is available at https://www.apache.org/licenses/LICENSE-2.0.
//
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
// ========================================================================
//
package org.eclipse.jetty.client;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.Map;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeoutException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.eclipse.jetty.io.AbstractConnection;
import org.eclipse.jetty.io.ClientConnectionFactory;
import org.eclipse.jetty.io.ClientConnector;
import org.eclipse.jetty.io.EndPoint;
import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.Callback;
import org.eclipse.jetty.util.Promise;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Client-side proxy configuration for SOCKS4, a de-facto standard.
* Consider using SOCK5 instead, a protocol that has been standardized
* by IETF.
*
* @see Socks5Proxy
*/
public class Socks4Proxy extends ProxyConfiguration.Proxy
{
/**
* Creates a new instance with the given SOCKS4 proxy host and port.
*
* @param host the SOCKS4 proxy host name
* @param port the SOCKS4 proxy port
*/
public Socks4Proxy(String host, int port)
{
this(new Origin.Address(host, port), false);
}
/**
* Creates a new instance with the given SOCKS4 proxy address.
* When {@code secure=true} the communication between the client and the
* proxy will be encrypted (using this proxy {@link #getSslContextFactory()}
* which typically defaults to that of {@link HttpClient}.
*
* @param address the SOCKS4 proxy address (host and port)
* @param secure whether the communication between the client and the SOCKS4 proxy should be secure
*/
public Socks4Proxy(Origin.Address address, boolean secure)
{
super(address, secure, null, null);
}
@Override
public ClientConnectionFactory newClientConnectionFactory(ClientConnectionFactory connectionFactory)
{
return new Socks4ProxyClientConnectionFactory(connectionFactory);
}
public static class Socks4ProxyClientConnectionFactory implements ClientConnectionFactory
{
private final ClientConnectionFactory connectionFactory;
public Socks4ProxyClientConnectionFactory(ClientConnectionFactory connectionFactory)
{
this.connectionFactory = connectionFactory;
}
@Override
public org.eclipse.jetty.io.Connection newConnection(EndPoint endPoint, Map context)
{
Destination destination = (Destination)context.get(HttpClientTransport.HTTP_DESTINATION_CONTEXT_KEY);
Executor executor = destination.getHttpClient().getExecutor();
Socks4ProxyConnection connection = new Socks4ProxyConnection(endPoint, executor, connectionFactory, context);
return customize(connection, context);
}
}
private static class Socks4ProxyConnection extends AbstractConnection implements Callback
{
private static final Pattern IPv4_PATTERN = Pattern.compile("(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})");
private static final Logger LOG = LoggerFactory.getLogger(Socks4ProxyConnection.class);
private final Socks4Parser parser = new Socks4Parser();
private final ClientConnectionFactory connectionFactory;
private final Map context;
public Socks4ProxyConnection(EndPoint endPoint, Executor executor, ClientConnectionFactory connectionFactory, Map context)
{
super(endPoint, executor);
this.connectionFactory = connectionFactory;
this.context = context;
}
@Override
public void onOpen()
{
super.onOpen();
writeSocks4Connect();
}
/**
* Writes the SOCKS "connect" bytes, differentiating between SOCKS 4 and 4A;
* the former sends an IPv4 address, the latter the full domain name.
*/
private void writeSocks4Connect()
{
Destination destination = (Destination)context.get(HttpClientTransport.HTTP_DESTINATION_CONTEXT_KEY);
Origin.Address address = destination.getOrigin().getAddress();
String host = address.getHost();
short port = (short)address.getPort();
Matcher matcher = IPv4_PATTERN.matcher(host);
if (matcher.matches())
{
// SOCKS 4
ByteBuffer buffer = ByteBuffer.allocate(9);
buffer.put((byte)4).put((byte)1).putShort(port);
for (int i = 1; i <= 4; ++i)
{
buffer.put((byte)Integer.parseInt(matcher.group(i)));
}
buffer.put((byte)0);
buffer.flip();
getEndPoint().write(this, buffer);
}
else
{
// SOCKS 4A
byte[] hostBytes = host.getBytes(StandardCharsets.UTF_8);
ByteBuffer buffer = ByteBuffer.allocate(9 + hostBytes.length + 1);
buffer.put((byte)4).put((byte)1).putShort(port);
buffer.put((byte)0).put((byte)0).put((byte)0).put((byte)1).put((byte)0);
buffer.put(hostBytes).put((byte)0);
buffer.flip();
getEndPoint().write(this, buffer);
}
}
@Override
public void succeeded()
{
if (LOG.isDebugEnabled())
LOG.debug("Written SOCKS4 connect request");
fillInterested();
}
@Override
public void failed(Throwable x)
{
if (LOG.isDebugEnabled())
LOG.debug("SOCKS4 failure", x);
getEndPoint().close(x);
@SuppressWarnings("unchecked")
Promise promise = (Promise)context.get(HttpClientTransport.HTTP_CONNECTION_PROMISE_CONTEXT_KEY);
promise.failed(x);
}
@Override
public boolean onIdleExpired(TimeoutException timeout)
{
failed(timeout);
return false;
}
@Override
public void onFillable()
{
try
{
while (true)
{
// Avoid to read too much from the socket: ask
// the parser how much left there is to read.
ByteBuffer buffer = BufferUtil.allocate(parser.expected());
int filled = getEndPoint().fill(buffer);
if (LOG.isDebugEnabled())
LOG.debug("Read SOCKS4 connect response, {} bytes", filled);
if (filled < 0)
throw new IOException("SOCKS4 tunnel failed, connection closed");
if (filled == 0)
{
fillInterested();
return;
}
if (parser.parse(buffer))
return;
}
}
catch (Throwable x)
{
failed(x);
}
}
private void onSocks4Response(int responseCode) throws IOException
{
if (responseCode == 0x5A)
tunnel();
else
throw new IOException("SOCKS4 tunnel failed with code " + responseCode);
}
private void tunnel()
{
try
{
Destination destination = (Destination)context.get(HttpClientTransport.HTTP_DESTINATION_CONTEXT_KEY);
Origin.Address address = destination.getOrigin().getAddress();
// Don't want to do DNS resolution here.
InetSocketAddress inet = InetSocketAddress.createUnresolved(address.getHost(), address.getPort());
context.put(ClientConnector.REMOTE_SOCKET_ADDRESS_CONTEXT_KEY, inet);
ClientConnectionFactory connectionFactory = this.connectionFactory;
if (destination.isSecure())
connectionFactory = destination.getHttpClient().newSslClientConnectionFactory(null, connectionFactory);
org.eclipse.jetty.io.Connection newConnection = connectionFactory.newConnection(getEndPoint(), context);
getEndPoint().upgrade(newConnection);
if (LOG.isDebugEnabled())
LOG.debug("SOCKS4 tunnel established: {} over {}", this, newConnection);
}
catch (Throwable x)
{
failed(x);
}
}
private class Socks4Parser
{
private static final int EXPECTED_LENGTH = 8;
private int cursor;
private int response;
private boolean parse(ByteBuffer buffer) throws IOException
{
while (buffer.hasRemaining())
{
byte current = buffer.get();
if (cursor == 1)
response = current & 0xFF;
++cursor;
if (cursor == EXPECTED_LENGTH)
{
onSocks4Response(response);
return true;
}
}
return false;
}
private int expected()
{
return EXPECTED_LENGTH - cursor;
}
}
}
}