pass.java

用java写的ftp服务器程序

// $Id: PASS.java 306757 2005-10-06 11:33:33 +0530 (Thu, 06 Oct 2005) rana_b $
/*
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed 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 org.apache.commons.logging.Log;
import org.apache.ftpserver.Command;
import org.apache.ftpserver.DirectoryLister;
import org.apache.ftpserver.FtpRequestImpl;
import org.apache.ftpserver.FtpWriter;
import org.apache.ftpserver.RequestHandler;
import org.apache.ftpserver.ftplet.FileSystemManager;
import org.apache.ftpserver.ftplet.FileSystemView;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.Ftplet;
import org.apache.ftpserver.ftplet.FtpletEnum;
import org.apache.ftpserver.ftplet.User;
import org.apache.ftpserver.ftplet.UserManager;
import org.apache.ftpserver.interfaces.IConnectionManager;
import org.apache.ftpserver.interfaces.IFtpConfig;
import org.apache.ftpserver.interfaces.IFtpStatistics;
import org.apache.ftpserver.usermanager.BaseUser;

/**
 * <code>PASS &lt;SP&gt; <password> &lt;CRLF&gt;</code><br>
 *
 * The argument field is a Telnet string specifying the user's
 * password.  This command must be immediately preceded by the
 * user name command.
 * 
 * @author <a href="mailto:[e-mail]">Rana Bhattacharyya</a>
 */
public 
class PASS implements Command {
    
    /**
     * Execute command.
     */
    public void execute(RequestHandler handler, 
                        FtpRequestImpl request, 
                        FtpWriter out) throws IOException, FtpException {
    
        boolean bSuccess = false;
        IFtpConfig fconfig = handler.getConfig();
        Log log = fconfig.getLogFactory().getInstance(getClass());
        IConnectionManager conManager = fconfig.getConnectionManager();
        IFtpStatistics stat = (IFtpStatistics)fconfig.getFtpStatistics();
        try {
            
            // reset state variables
            request.resetState();
            
            // argument check
            String password = request.getArgument();
            if(password == null) {
                out.send(501, "PASS", null);
                return; 
            }
            
            // check user name
            User user = request.getUser();
            String userName = user.getName();
            if(userName == null) {
                out.send(503, "PASS", null);
                return;
            }
            
            // already logged-in
            if(request.isLoggedIn()) {
                out.send(202, "PASS", null);
                bSuccess = true;
                return;
            }
            
            // anonymous login limit check
            boolean bAnonymous = userName.equals("anonymous");
            int currAnonLogin = stat.getCurrentAnonymousLoginNumber();
            int maxAnonLogin = conManager.getMaxAnonymousLogins();
            if( bAnonymous && (currAnonLogin >= maxAnonLogin) ) {
                out.send(421, "PASS.anonymous", null);
                return;
            }
            
            // login limit check
            int currLogin = stat.getCurrentLoginNumber();
            int maxLogin = conManager.getMaxLogins();
            if(currLogin >= maxLogin) {
                out.send(421, "PASS.login", null);
                return;
            }
            
            // authenticate user
            UserManager userManager = fconfig.getUserManager();
            try {
                if(bAnonymous) {
                    bSuccess = userManager.doesExist("anonymous");
                }
                else {
                    bSuccess = userManager.authenticate(userName, password);
                }
            }
            catch(Exception ex) {
                bSuccess = false;
                log.warn("PASS.execute()", ex);
            }
            if(!bSuccess) {
                log.warn("Login failure - " + userName);
                out.send(530, "PASS", userName);
                return;
            }
            
            // populate user information
            try {
                populateUser(handler, userName);
            }
            catch(FtpException ex) {
                bSuccess = false;
            }
            if(!bSuccess) {
                out.send(530, "PASS", userName);
                return;
            }
            
            // everything is fine - send login ok message
            out.send(230, "PASS", userName);
            if(bAnonymous) {
                log.info("Anonymous login success - " + password);
            }
            else {
                log.info("Login success - " + userName);
            }
            
            // update different objects
            FileSystemManager fmanager = fconfig.getFileSystemManager(); 
            FileSystemView fsview = fmanager.createFileSystemView(user);
            handler.setDirectoryLister(new DirectoryLister(fsview));
            request.setLogin(fsview);
            stat.setLogin(handler);
            
            // call Ftplet.onLogin() method
            Ftplet ftpletContainer = fconfig.getFtpletContainer();
            FtpletEnum ftpletRet = ftpletContainer.onLogin(request, out);
            if(ftpletRet == FtpletEnum.RET_DISCONNECT) {
                fconfig.getConnectionManager().closeConnection(handler);
                return;
            }    
        }
        finally {
            
            // if login failed - close connection
            if(!bSuccess) {
                conManager.closeConnection(handler);
            }
        }
    }

    /**
     * Populate user.
     */
    private void populateUser(RequestHandler handler,
                              String login) throws FtpException {
        
        User user = handler.getConfig().getUserManager().getUserByName(login);
        if(user == null) {
            throw new FtpException(login + " : does not exist.");
        }
        
        BaseUser reqUser = (BaseUser)handler.getRequest().getUser();
        reqUser.setName(user.getName());
        reqUser.setEnabled(user.getEnabled());
        reqUser.setHomeDirectory(user.getHomeDirectory());
        reqUser.setMaxDownloadRate(user.getMaxDownloadRate());
        reqUser.setMaxDownloadRate(user.getMaxDownloadRate());
        reqUser.setMaxIdleTime(user.getMaxIdleTime());
        reqUser.setWritePermission(user.getWritePermission());
    }
}