clientheartbeataction.java

这是linux下ssl vpn的实现程序

/*
 *  SSL-Explorer
 *
 *  Copyright (C) 2003-2006 3SP LTD. All Rights Reserved
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2 of
 *  the License, or (at your option) any later version.
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public
 *  License along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
			
package com.sslexplorer.agent.actions;

import java.util.Iterator;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.jdom.Document;
import org.jdom.Element;

import com.sslexplorer.core.CoreServlet;
import com.sslexplorer.core.actions.XMLOutputAction;
import com.sslexplorer.security.VPNSession;

/**
 * Processes heartbearts sent from the <i>SSL-Explorer Agent</i> or
 * an application using the <i>Embedded Client API</i> at
 * regular intervals to ensure the connection is kept alive.
 * <p>
 * If a heartbeat is not received with a specified interval then the
 * VPN session will be invalidated.
 * 
 * @author Lee David Painter <a href="mailto: [e-mail]">&lt;[e-mail]&gt;</a>
 * @version $Revision: 1.4 $
 */
public class ClientHeartbeatAction extends XMLOutputAction {

    static Log log = LogFactory.getLog(ClientHeartbeatAction.class);

    /**
     * Constructor.
     */
    public ClientHeartbeatAction() {
    }

    /* (non-Javadoc)
     * @see org.apache.struts.action.Action#execute(org.apache.struts.action.ActionMapping, org.apache.struts.action.ActionForm, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     */
    public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response)
                    throws Exception {

    	if (log.isDebugEnabled())
    		log.debug("Heartbeat received from " + request.getRemoteHost());

        try {
            // Get the VPN session
            VPNSession session = CoreServlet.getServlet().getLogonController().getVPNSession(request);

            // Check that we were returned a value
            if (session == null) {
                log.warn(request.getRemoteHost() + " cannot send heartbeat because the VPN session is invalid");
                sendError("Invalid VPN session!", response);
            } else {
                if (session.getLastAccessTime() == -1) {

                	if (log.isInfoEnabled())
                		log.info("Informing " + request.getRemoteHost() + " to shutdown because its VPN session is now invalid");

                    CoreServlet.getServlet().getLogonController().removeVPNClient(session);

                    Element root = new Element("shutdown");
                    Document doc = new Document(root);
                    sendDocument(doc, response);

                } else {

                	if (log.isDebugEnabled())
                		log.debug("Heartbeat from " + request.getRemoteHost() + " is OK");

                    long now = System.currentTimeMillis();
                    if (session.getFirstAccessTime() == -1) {
                        synchronized (session) {
                            /*
                             * Notify the the client registration monitor that
                             * the client has sent its first heartbeat and so is
                             * completely started up.
                             */
                            session.setFirstAccessTime(now);
                            session.notify();
                        }
                    }

                    // Send the success document
                    session.setLastAccessTime(now);

                    //
                    Element root = new Element("success");
                    for (Iterator i = session.messages(); i.hasNext();) {
                        VPNSession.Message message = (VPNSession.Message) i.next();
                        Element mesg = new Element("message");
                        mesg.setAttribute("type", String.valueOf(message.getType()));
                        mesg.setAttribute("title", message.getTitle());
                        mesg.setText(message.getMessage());
                        root.addContent(mesg);
                    }
                    session.clearMessages();
                    Document doc = new Document(root);
                    sendDocument(doc, response);
                }
            }
        } catch (Exception ex) {
            log.error("Heartbeat from " + request.getRemoteHost() + " failed", ex);
        }

        return null;
    }
}