/*
* 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;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import org.apache.ftpserver.DataConnectionException;
import org.apache.ftpserver.ServerDataConnectionFactory;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.FtpReply;
import org.apache.ftpserver.ftplet.FtpRequest;
import org.apache.ftpserver.interfaces.FtpIoSession;
import org.apache.ftpserver.interfaces.FtpServerContext;
import org.apache.ftpserver.util.FtpReplyUtil;
import org.apache.ftpserver.util.SocketAddressEncoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <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.
*/
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();
InetAddress externalPassiveAddress = session.getListener().getDataConnectionConfiguration().getPassiveExernalAddress();
try {
InetSocketAddress dataConAddress = dataCon.initPassiveDataConnection();
// get connection info
InetAddress servAddr;
if(externalPassiveAddress != null) {
servAddr = externalPassiveAddress;
} else {
servAddr = dataConAddress.getAddress();
}
// send connection info to client
InetSocketAddress externalDataConAddress = new InetSocketAddress(servAddr, dataConAddress.getPort());
String addrStr = SocketAddressEncoder.encode(externalDataConAddress);
session.write(FtpReplyUtil.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(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_425_CANT_OPEN_DATA_CONNECTION, "PASV", null));
return;
}
}
}