/*
* 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.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.socksx.v4.Socks4CmdRequest;
import io.netty.handler.codec.socksx.v4.Socks4CmdResponse;
import io.netty.handler.codec.socksx.v4.Socks4CmdResponseDecoder;
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 java.net.InetSocketAddress;
import java.net.SocketAddress;
public final class Socks4ProxyHandler extends ProxyHandler {
private static final String PROTOCOL = "socks4";
private static final String AUTH_USERNAME = "username";
private final String username;
private String decoderName;
private String encoderName;
public Socks4ProxyHandler(SocketAddress proxyAddress) {
this(proxyAddress, null);
}
public Socks4ProxyHandler(SocketAddress proxyAddress, String username) {
super(proxyAddress);
if (username != null && username.length() == 0) {
username = null;
}
this.username = username;
}
@Override
public String protocol() {
return PROTOCOL;
}
@Override
public String authScheme() {
return username != null? AUTH_USERNAME : AUTH_NONE;
}
public String username() {
return username;
}
@Override
protected void addCodec(ChannelHandlerContext ctx) throws Exception {
ChannelPipeline p = ctx.pipeline();
String name = ctx.name();
Socks4CmdResponseDecoder decoder = new Socks4CmdResponseDecoder();
p.addBefore(name, null, decoder);
decoderName = p.context(decoder).name();
encoderName = decoderName + ".encoder";
p.addBefore(name, encoderName, Socks4MessageEncoder.INSTANCE);
}
@Override
protected void removeEncoder(ChannelHandlerContext ctx) throws Exception {
ChannelPipeline p = ctx.pipeline();
p.remove(encoderName);
}
@Override
protected void removeDecoder(ChannelHandlerContext ctx) throws Exception {
ChannelPipeline p = ctx.pipeline();
p.remove(decoderName);
}
@Override
protected Object newInitialMessage(ChannelHandlerContext ctx) throws Exception {
InetSocketAddress raddr = destinationAddress();
String rhost;
if (raddr.isUnresolved()) {
rhost = raddr.getHostString();
} else {
rhost = raddr.getAddress().getHostAddress();
}
return new Socks4CmdRequest(
username != null? username : "", Socks4CmdType.CONNECT, rhost, raddr.getPort());
}
@Override
protected boolean handleResponse(ChannelHandlerContext ctx, Object response) throws Exception {
final Socks4CmdResponse res = (Socks4CmdResponse) response;
final Socks4CmdStatus status = res.cmdStatus();
if (status == Socks4CmdStatus.SUCCESS) {
return true;
}
throw new ProxyConnectException(exceptionMessage("cmdStatus: " + status));
}
}