core/src/main/java/org/apache/ftpserver/command/impl/APPE.java

/*
 * 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.io.OutputStream;
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.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>APPE &lt;SP&gt; &lt;pathname&gt; &lt;CRLF&gt;</code><br>
 * 
 * This command causes the server-DTP to accept the data transferred via the
 * data connection and to store the data in a file at the server site. If the
 * file specified in the pathname exists at the server site, then the data shall
 * be appended to that file; otherwise the file specified in the pathname shall
 * be created at the server site.
 *
 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
 */
public class APPE extends AbstractCommand {

    private final Logger LOG = LoggerFactory.getLogger(APPE.class);

    /**
     * Execute command.
     */
    public void execute(final FtpIoSession session,
            final FtpServerContext context, final FtpRequest request)
            throws IOException, FtpException {

        try {

            // reset state variables
            session.resetState();

            // 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,
                                        "APPE", null, null));
                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 filenames
            FtpFile file = null;
            try {
                file = session.getFileSystemView().getFile(fileName);
            } catch (Exception e) {
                LOG.debug("File system threw exception", e);
            }
            if (file == null) {
                session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
                        FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN,
                        "APPE.invalid", fileName, null));
                return;
            }
            fileName = file.getAbsolutePath();

            // check file existance
            if (file.doesExist() && !file.isFile()) {
                session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
                        FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN,
                        "APPE.invalid", fileName, file));
                return;
            }

            // check permission
            if (!file.isWritable()) {
                session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
                        FtpReply.REPLY_550_REQUESTED_ACTION_NOT_TAKEN,
                        "APPE.permission", fileName, file));
                return;
            }

            // get data connection
            session.write(LocalizedFtpReply.translate(session, request, context,
                    FtpReply.REPLY_150_FILE_STATUS_OKAY, "APPE", fileName));

            DataConnection dataConnection;
            try {
                dataConnection = session.getDataConnection().openConnection();
            } catch (Exception e) {
                LOG.debug("Exception when getting data input stream", e);
                session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
                        FtpReply.REPLY_425_CANT_OPEN_DATA_CONNECTION, "APPE",
                        fileName, file));
                return;
            }

            // get data from client
            boolean failure = false;
            OutputStream os = null;
            long transSz = 0L;
            try {

                // find offset
                long offset = 0L;
                if (file.doesExist()) {
                    offset = file.getSize();
                }

                // open streams
                os = file.createOutputStream(offset);

                // transfer data
                transSz = dataConnection.transferFromClient(session.getFtpletSession(), os);

                // attempt to close the output stream so that errors in 
                // closing it will return an error to the client (FTPSERVER-119) 
                if(os != null) {
                    os.close();
                }

                LOG.info("File uploaded {}", fileName);

                // notify the statistics component
                ServerFtpStatistics ftpStat = (ServerFtpStatistics) context
                        .getFtpStatistics();
                ftpStat.setUpload(session, file, transSz);
                
            } catch (SocketException e) {
                LOG.debug("SocketException during file upload", e);
                failure = true;
                session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
                        FtpReply.REPLY_426_CONNECTION_CLOSED_TRANSFER_ABORTED,
                        "APPE", fileName, file));
            } catch (IOException e) {
                LOG.debug("IOException during file upload", e);
                failure = true;
                session
                        .write(LocalizedDataTransferFtpReply
                                .translate(
                                        session,
                                        request,
                                        context,
                                        FtpReply.REPLY_551_REQUESTED_ACTION_ABORTED_PAGE_TYPE_UNKNOWN,
                                        "APPE", fileName, file));
            } finally {
                // make sure we really close the output stream
                IoUtils.close(os);
            }

            // if data transfer ok - send transfer complete message
            if (!failure) {
                session.write(LocalizedDataTransferFtpReply.translate(session, request, context,
                        FtpReply.REPLY_226_CLOSING_DATA_CONNECTION, "APPE",
                        fileName, file, transSz));
            }
        } finally {
            session.getDataConnection().closeDataConnection();
        }
    }
}