/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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 org.apache.mina.proxy.handlers.socks;
import org.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.core.filterchain.IoFilter.NextFilter;
import org.apache.mina.proxy.session.ProxyIoSession;
import org.apache.mina.proxy.utils.ByteUtilities;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Socks4LogicHandler.java - SOCKS4/SOCKS4a authentication mechanisms logic handler.
*
* @author The Apache MINA Project (dev@mina.apache.org)
* @version $Rev: 714192 $, $Date: 2008-11-15 00:45:52 +0100 (Sat, 15 Nov 2008) $
* @since MINA 2.0.0-M3
*/
public class Socks4LogicHandler extends AbstractSocksLogicHandler {
private final static Logger logger = LoggerFactory
.getLogger(Socks4LogicHandler.class);
/**
* {@inheritDoc}
*/
public Socks4LogicHandler(final ProxyIoSession proxyIoSession) {
super(proxyIoSession);
}
/**
* Perform the handshake.
*
* @param nextFilter the next filter
*/
public void doHandshake(final NextFilter nextFilter) {
logger.debug(" doHandshake()");
// Send request
writeRequest(nextFilter, request);
}
/**
* Encode a SOCKS4/SOCKS4a request and writes it to the next filter
* so it can be sent to the proxy server.
*
* @param nextFilter the next filter
* @param request the request to send.
*/
protected void writeRequest(final NextFilter nextFilter,
final SocksProxyRequest request) {
try {
boolean isV4ARequest = request.getHost() != null;
byte[] userID = request.getUserName().getBytes("ASCII");
byte[] host = isV4ARequest ? request.getHost().getBytes("ASCII")
: null;
int len = 9 + userID.length;
if (isV4ARequest) {
len += host.length + 1;
}
IoBuffer buf = IoBuffer.allocate(len);
buf.put(request.getProtocolVersion());
buf.put(request.getCommandCode());
buf.put(request.getPort());
buf.put(request.getIpAddress());
buf.put(userID);
buf.put(SocksProxyConstants.TERMINATOR);
if (isV4ARequest) {
buf.put(host);
buf.put(SocksProxyConstants.TERMINATOR);
}
if (isV4ARequest) {
logger.debug(" sending SOCKS4a request");
} else {
logger.debug(" sending SOCKS4 request");
}
buf.flip();
writeData(nextFilter, buf);
} catch (Exception ex) {
closeSession("Unable to send Socks request: ", ex);
}
}
/**
* Handle incoming data during the handshake process. Should consume only the
* handshake data from the buffer, leaving any extra data in place.
*
* @param nextFilter the next filter
* @param buf the server response data buffer
*/
public void messageReceived(final NextFilter nextFilter,
final IoBuffer buf) {
try {
if (buf.remaining() >= SocksProxyConstants.SOCKS_4_RESPONSE_SIZE) {
handleResponse(buf);
}
} catch (Exception ex) {
closeSession("Proxy handshake failed: ", ex);
}
}
/**
* Handle a SOCKS4/SOCKS4a response from the proxy server. Test
* the response buffer reply code and call {@link #setHandshakeComplete()}
* if access is granted.
*
* @param buf the buffer holding the server response data.
* @throws exception if server response is malformed or if request is rejected
* by the proxy server.
*/
protected void handleResponse(final IoBuffer buf) throws Exception {
byte first = buf.get(0);
if (first != 0) {
throw new Exception("Socks response seems to be malformed");
}
byte status = buf.get(1);
// Consumes all the response data from the buffer
buf.position(buf.position() + SocksProxyConstants.SOCKS_4_RESPONSE_SIZE);
if (status == SocksProxyConstants.V4_REPLY_REQUEST_GRANTED) {
setHandshakeComplete();
} else {
throw new Exception("Proxy handshake failed - Code: 0x"
+ ByteUtilities.asHex(new byte[] { status }) + " ("
+ SocksProxyConstants.getReplyCodeAsString(status) + ")");
}
}
}