/*
* 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.ftpserver.command.impl;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import org.apache.ftpserver.DataConnectionException;
import org.apache.ftpserver.command.AbstractCommand;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.FtpReply;
import org.apache.ftpserver.ftplet.FtpRequest;
import org.apache.ftpserver.impl.FtpIoSession;
import org.apache.ftpserver.impl.FtpServerContext;
import org.apache.ftpserver.impl.LocalizedFtpReply;
import org.apache.ftpserver.impl.ServerDataConnectionFactory;
import org.apache.ftpserver.util.SocketAddressEncoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <strong>Internal class, do not use directly.</strong>
*
* <code>PASV <CRLF></code><br>
*
* This command requests the server-DTP to "listen" on a data port (which is not
* its default data port) and to wait for a connection rather than initiate one
* upon receipt of a transfer command. The response to this command includes the
* host and port address this server is listening on.
*
* @author <a href="http://mina.apache.org">Apache MINA Project</a>
*/
public class PASV extends AbstractCommand {
private final Logger LOG = LoggerFactory.getLogger(PASV.class);
/**
* Execute command
*/
public void execute(final FtpIoSession session,
final FtpServerContext context, final FtpRequest request)
throws IOException, FtpException {
// reset state variables
session.resetState();
// set data connection
ServerDataConnectionFactory dataCon = session.getDataConnection();
String externalPassiveAddress = session.getListener()
.getDataConnectionConfiguration().getPassiveExernalAddress();
try {
InetSocketAddress dataConAddress = dataCon
.initPassiveDataConnection();
// get connection info
InetAddress servAddr;
if (externalPassiveAddress != null) {
servAddr = resolveAddress(externalPassiveAddress);
} else {
servAddr = dataConAddress.getAddress();
}
// send connection info to client
InetSocketAddress externalDataConAddress = new InetSocketAddress(
servAddr, dataConAddress.getPort());
String addrStr = SocketAddressEncoder
.encode(externalDataConAddress);
session.write(LocalizedFtpReply.translate(session, request, context,
FtpReply.REPLY_227_ENTERING_PASSIVE_MODE, "PASV", addrStr));
} catch (DataConnectionException e) {
LOG.warn("Failed to open passive data connection", e);
session
.write(LocalizedFtpReply.translate(session, request, context,
FtpReply.REPLY_425_CANT_OPEN_DATA_CONNECTION,
"PASV", null));
return;
}
}
/*
* (non-Javadoc)
* Returns an InetAddress object from a hostname or IP address.
*/
private InetAddress resolveAddress(String host) throws DataConnectionException{
try{
return InetAddress.getByName(host);
}catch(UnknownHostException ex){
throw new DataConnectionException(ex.getLocalizedMessage(),ex);
}
}
}