/*
* 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.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.InetAddress;
import java.net.SocketException;
import org.apache.ftpserver.command.AbstractCommand;
import org.apache.ftpserver.ftplet.DataConnection;
import org.apache.ftpserver.ftplet.DataConnectionFactory;
import org.apache.ftpserver.ftplet.DataType;
import org.apache.ftpserver.ftplet.DefaultFtpReply;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.FtpFile;
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.IODataConnectionFactory;
import org.apache.ftpserver.impl.LocalizedDataTransferFtpReply;
import org.apache.ftpserver.impl.LocalizedFtpReply;
import org.apache.ftpserver.impl.ServerFtpStatistics;
import org.apache.ftpserver.util.IoUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <strong>Internal class, do not use directly.</strong>
*
* <code>RETR <SP> <pathname> <CRLF></code><br>
*
* This command causes the server-DTP to transfer a copy of the file, specified
* in the pathname, to the server- or user-DTP at the other end of the data
* connection. The status and contents of the file at the server site shall be
* unaffected.
*
* @author <a href="http://mina.apache.org">Apache MINA Project</a>
*/
public class RETR extends AbstractCommand {
private final Logger LOG = LoggerFactory.getLogger(RETR.class);
/**
* Execute command.
*/
public void execute(final FtpIoSession session,
final FtpServerContext context, final FtpRequest request)
throws IOException, FtpException {
try {
// get state variable
long skipLen = session.getFileOffset();
// argument check
String fileName = request.getArgument();
if (fileName == null) {
session.write(LocalizedDataTransferFtpReply.translate(
session,
request,
context,
FtpReply.REPLY_501_SYNTAX_ERROR_IN_PARAMETERS_OR_ARGUMENTS,
"RETR", null, null));
return;
}
// get file object
FtpFile file = null;
try {
file = session.getFileSystemView().getFile(fileName);
} catch (Exception ex) {
LOG.debug("Exception getting file object", ex);
}
if (file == null) {
session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN,
"RETR.missing", fileName, file));
return;
}
fileName = file.getAbsolutePath();
// check file existance
if (!file.doesExist()) {
session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN,
"RETR.missing", fileName, file));
return;
}
// check valid file
if (!file.isFile()) {
session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN,
"RETR.invalid", fileName, file));
return;
}
// check permission
if (!file.isReadable()) {
session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN,
"RETR.permission", fileName, file));
return;
}
// 24-10-2007 - added check if PORT or PASV is issued, see
// https://issues.apache.org/jira/browse/FTPSERVER-110
//TODO move this block of code into the super class. Also, it makes
//sense to have this as the first check before checking everything
//else such as the file and its permissions.
DataConnectionFactory connFactory = session.getDataConnection();
if (connFactory instanceof IODataConnectionFactory) {
InetAddress address = ((IODataConnectionFactory) connFactory)
.getInetAddress();
if (address == null) {
session.write(new DefaultFtpReply(
FtpReply.REPLY_503_BAD_SEQUENCE_OF_COMMANDS,
"PORT or PASV must be issued first"));
return;
}
}
// get data connection
session.write(LocalizedFtpReply.translate(session, request, context,
FtpReply.REPLY_150_FILE_STATUS_OKAY, "RETR", null));
// send file data to client
boolean failure = false;
InputStream is = null;
DataConnection dataConnection;
try {
dataConnection = session.getDataConnection().openConnection();
} catch (Exception e) {
LOG.debug("Exception getting the output data stream", e);
session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
FtpReply.REPLY_425_CANT_OPEN_DATA_CONNECTION, "RETR",
null, file));
return;
}
long transSz = 0L;
try {
// open streams
is = openInputStream(session, file, skipLen);
// transfer data
transSz = dataConnection.transferToClient(session.getFtpletSession(), is);
// attempt to close the input stream so that errors in
// closing it will return an error to the client (FTPSERVER-119)
if(is != null) {
is.close();
}
LOG.info("File downloaded {}", fileName);
// notify the statistics component
ServerFtpStatistics ftpStat = (ServerFtpStatistics) context
.getFtpStatistics();
if (ftpStat != null) {
ftpStat.setDownload(session, file, transSz);
}
} catch (SocketException ex) {
LOG.debug("Socket exception during data transfer", ex);
failure = true;
session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
FtpReply.REPLY_426_CONNECTION_CLOSED_TRANSFER_ABORTED,
"RETR", fileName, file, transSz));
} catch (IOException ex) {
LOG.debug("IOException during data transfer", ex);
failure = true;
session
.write(LocalizedDataTransferFtpReply
.translate(
session,
request,
context,
FtpReply.REPLY_551_REQUESTED_ACTION_ABORTED_PAGE_TYPE_UNKNOWN,
"RETR", fileName, file, transSz));
} finally {
// make sure we really close the input stream
IoUtils.close(is);
}
// if data transfer ok - send transfer complete message
if (!failure) {
session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
FtpReply.REPLY_226_CLOSING_DATA_CONNECTION, "RETR",
fileName, file, transSz));
}
} finally {
session.resetState();
session.getDataConnection().closeDataConnection();
}
}
/**
* Skip length and open input stream.
*/
public InputStream openInputStream(FtpIoSession session, FtpFile file,
long skipLen) throws IOException {
InputStream in;
if (session.getDataType() == DataType.ASCII) {
int c;
long offset = 0L;
in = new BufferedInputStream(file.createInputStream(0L));
while (offset++ < skipLen) {
if ((c = in.read()) == -1) {
throw new IOException("Cannot skip");
}
if (c == '\n') {
offset++;
}
}
} else {
in = file.createInputStream(skipLen);
}
return in;
}
}