/*
* 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.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.InetAddress;
import java.net.SocketException;
import org.apache.ftpserver.DefaultFtpReply;
import org.apache.ftpserver.IODataConnectionFactory;
import org.apache.ftpserver.ftplet.DataConnection;
import org.apache.ftpserver.ftplet.DataConnectionFactory;
import org.apache.ftpserver.ftplet.DataType;
import org.apache.ftpserver.ftplet.FileObject;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.FtpReply;
import org.apache.ftpserver.ftplet.FtpRequest;
import org.apache.ftpserver.ftplet.Ftplet;
import org.apache.ftpserver.ftplet.FtpletEnum;
import org.apache.ftpserver.interfaces.FtpIoSession;
import org.apache.ftpserver.interfaces.FtpServerContext;
import org.apache.ftpserver.interfaces.ServerFtpStatistics;
import org.apache.ftpserver.util.FtpReplyUtil;
import org.apache.ftpserver.util.IoUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <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.
*/
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(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_501_SYNTAX_ERROR_IN_PARAMETERS_OR_ARGUMENTS, "RETR", null));
return;
}
// call Ftplet.onDownloadStart() method
Ftplet ftpletContainer = context.getFtpletContainer();
FtpletEnum ftpletRet;
try {
ftpletRet = ftpletContainer.onDownloadStart(session.getFtpletSession(), request);
} catch(Exception e) {
LOG.debug("Ftplet container threw exception", e);
ftpletRet = FtpletEnum.RET_DISCONNECT;
}
if(ftpletRet == FtpletEnum.RET_SKIP) {
return;
}
else if(ftpletRet == FtpletEnum.RET_DISCONNECT) {
session.closeOnFlush().awaitUninterruptibly(10000);
return;
}
// get file object
FileObject file = null;
try {
file = session.getFileSystemView().getFileObject(fileName);
}
catch(Exception ex) {
LOG.debug("Exception getting file object", ex);
}
if(file == null) {
session.write(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN, "RETR.missing", fileName));
return;
}
fileName = file.getFullName();
// check file existance
if(!file.doesExist()) {
session.write(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN, "RETR.missing", fileName));
return;
}
// check valid file
if(!file.isFile()) {
session.write(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN, "RETR.invalid", fileName));
return;
}
// check permission
if(!file.hasReadPermission()) {
session.write(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN, "RETR.permission", fileName));
return;
}
// 24-10-2007 - added check if PORT or PASV is issued, see https://issues.apache.org/jira/browse/FTPSERVER-110
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(FtpReplyUtil.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(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_425_CANT_OPEN_DATA_CONNECTION, "RETR", null));
return;
}
try {
// open streams
is = openInputStream(session, file, skipLen);
// transfer data
long transSz = dataConnection.transferToClient(is);
// log message
String userName = session.getUser().getName();
LOG.info("File download : " + userName + " - " + 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(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_426_CONNECTION_CLOSED_TRANSFER_ABORTED, "RETR", fileName));
}
catch(IOException ex) {
LOG.debug("IOException during data transfer", ex);
failure = true;
session.write(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_551_REQUESTED_ACTION_ABORTED_PAGE_TYPE_UNKNOWN, "RETR", fileName));
}
finally {
IoUtils.close(is);
}
// if data transfer ok - send transfer complete message
if(!failure) {
session.write(FtpReplyUtil.translate(session, request, context, FtpReply.REPLY_226_CLOSING_DATA_CONNECTION, "RETR", fileName));
// call Ftplet.onDownloadEnd() method
try {
ftpletRet = ftpletContainer.onDownloadEnd(session.getFtpletSession(), request);
} catch(Exception e) {
LOG.debug("Ftplet container threw exception", e);
ftpletRet = FtpletEnum.RET_DISCONNECT;
}
if(ftpletRet == FtpletEnum.RET_DISCONNECT) {
session.closeOnFlush().awaitUninterruptibly(10000);
return;
}
}
}
finally {
session.resetState();
session.getDataConnection().closeDataConnection();
}
}
/**
* Skip length and open input stream.
*/
public InputStream openInputStream(FtpIoSession session,
FileObject 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;
}
}