/*
* Copyright 2014 The Netty Project
*
* The Netty Project licenses this file to you 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 io.netty.handler.proxy;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.socksx.v4.Socks4CmdRequest;
import io.netty.handler.codec.socksx.v4.Socks4CmdRequestDecoder;
import io.netty.handler.codec.socksx.v4.Socks4CmdResponse;
import io.netty.handler.codec.socksx.v4.Socks4CmdStatus;
import io.netty.handler.codec.socksx.v4.Socks4CmdType;
import io.netty.handler.codec.socksx.v4.Socks4MessageEncoder;
import io.netty.util.CharsetUtil;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import static org.hamcrest.CoreMatchers.*;
import static org.junit.Assert.*;
final class Socks4ProxyServer extends ProxyServer {
Socks4ProxyServer(boolean useSsl, TestMode testMode, InetSocketAddress destination) {
super(useSsl, testMode, destination);
}
Socks4ProxyServer(boolean useSsl, TestMode testMode, InetSocketAddress destination, String username) {
super(useSsl, testMode, destination, username, null);
}
@Override
protected void configure(SocketChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
switch (testMode) {
case INTERMEDIARY:
p.addLast(new Socks4CmdRequestDecoder());
p.addLast(Socks4MessageEncoder.INSTANCE);
p.addLast(new Socks4IntermediaryHandler());
break;
case TERMINAL:
p.addLast(new Socks4CmdRequestDecoder());
p.addLast(Socks4MessageEncoder.INSTANCE);
p.addLast(new Socks4TerminalHandler());
break;
case UNRESPONSIVE:
p.addLast(UnresponsiveHandler.INSTANCE);
break;
}
}
private boolean authenticate(ChannelHandlerContext ctx, Socks4CmdRequest req) {
assertThat(req.cmdType(), is(Socks4CmdType.CONNECT));
if (testMode != TestMode.INTERMEDIARY) {
ctx.pipeline().addBefore(ctx.name(), "lineDecoder", new LineBasedFrameDecoder(64, false, true));
}
boolean authzSuccess;
if (username != null) {
authzSuccess = username.equals(req.userId());
} else {
authzSuccess = true;
}
return authzSuccess;
}
private final class Socks4IntermediaryHandler extends IntermediaryHandler {
private SocketAddress intermediaryDestination;
@Override
protected boolean handleProxyProtocol(ChannelHandlerContext ctx, Object msg) throws Exception {
Socks4CmdRequest req = (Socks4CmdRequest) msg;
Socks4CmdResponse res;
if (!authenticate(ctx, req)) {
res = new Socks4CmdResponse(Socks4CmdStatus.IDENTD_AUTH_FAILURE);
} else {
res = new Socks4CmdResponse(Socks4CmdStatus.SUCCESS);
intermediaryDestination = new InetSocketAddress(req.host(), req.port());
}
ctx.write(res);
ctx.pipeline().remove(Socks4MessageEncoder.class);
return true;
}
@Override
protected SocketAddress intermediaryDestination() {
return intermediaryDestination;
}
}
private final class Socks4TerminalHandler extends TerminalHandler {
@Override
protected boolean handleProxyProtocol(ChannelHandlerContext ctx, Object msg) throws Exception {
Socks4CmdRequest req = (Socks4CmdRequest) msg;
boolean authzSuccess = authenticate(ctx, req);
Socks4CmdResponse res;
boolean sendGreeting = false;
if (!authzSuccess) {
res = new Socks4CmdResponse(Socks4CmdStatus.IDENTD_AUTH_FAILURE);
} else if (!req.host().equals(destination.getHostString()) ||
req.port() != destination.getPort()) {
res = new Socks4CmdResponse(Socks4CmdStatus.REJECTED_OR_FAILED);
} else {
res = new Socks4CmdResponse(Socks4CmdStatus.SUCCESS);
sendGreeting = true;
}
ctx.write(res);
ctx.pipeline().remove(Socks4MessageEncoder.class);
if (sendGreeting) {
ctx.write(Unpooled.copiedBuffer("0\n", CharsetUtil.US_ASCII));
}
return true;
}
}
}