SshClient.java

/*******************************************************************************
 * This file is part of OpenNMS(R).
 *
 * Copyright (C) 2008-2011 The OpenNMS Group, Inc.
 * OpenNMS(R) is Copyright (C) 1999-2011 The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
 *
 * OpenNMS(R) 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 3 of the License,
 * or (at your option) any later version.
 *
 * OpenNMS(R) 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 OpenNMS(R).  If not, see:
 *      http://www.gnu.org/licenses/
 *
 * For more information contact:
 *     OpenNMS(R) Licensing <license@opennms.org>
 *     http://www.opennms.org/
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 *******************************************************************************/

package org.opennms.netmgt.provision.detector.ssh.client;

import java.io.IOException;
import java.net.InetAddress;
import java.util.Collections;
import java.util.Map;

import org.apache.regexp.RE;
import org.opennms.core.utils.LogUtils;
import org.opennms.core.utils.TimeoutTracker;
import org.opennms.netmgt.model.PollStatus;
import org.opennms.netmgt.provision.detector.ssh.request.NullRequest;
import org.opennms.netmgt.provision.detector.ssh.response.SshResponse;
import org.opennms.netmgt.provision.support.Client;
import org.opennms.netmgt.provision.support.ssh.InsufficientParametersException;
import org.opennms.netmgt.provision.support.ssh.Ssh;

/**
 * <p>SshClient class.</p>
 *
 * @author thedesloge
 * @version $Id: $
 */
public class SshClient implements Client<NullRequest, SshResponse> {
    
    private boolean m_isAvailable = false;
    
    private String m_banner = null;
    private String m_match = null;
    private String m_clientBanner = Ssh.DEFAULT_CLIENT_BANNER;
    
    public static final int DEFAULT_RETRY = 0;
    
    /**
     * <p>close</p>
     */
    public void close() {
        
    }

    /** {@inheritDoc} */
    public void connect(InetAddress address, int port, int timeout) throws IOException, Exception {
        Map<String,?> emptyMap = Collections.emptyMap();
        TimeoutTracker tracker = new TimeoutTracker(emptyMap, SshClient.DEFAULT_RETRY, timeout);
        
        String banner = m_banner;
        String match = m_match;
        String clientBanner = m_clientBanner;
        PollStatus ps = PollStatus.unavailable();
        
        Ssh ssh = new Ssh(address, port, tracker.getConnectionTimeout());
        ssh.setClientBanner(clientBanner);
        
        RE regex = null;
        if (match == null && (banner == null || banner.equals("*"))) {
            regex = null;
        } else if (match != null) {
            regex = new RE(match);
        } else if (banner != null) {
            regex = new RE(banner);
        }
        
        for (tracker.reset(); tracker.shouldRetry() && !ps.isAvailable(); tracker.nextAttempt()) {
            try {
                ps = ssh.poll(tracker);
            } catch (InsufficientParametersException e) {
                LogUtils.errorf(this, e.getMessage());
                break;
            }
        
        }
        
        // If banner matching string is null or wildcard ("*") then we
        // only need to test connectivity and we've got that!
        
        if (regex != null && ps.isAvailable()) {
            String response = ssh.getServerBanner();
        
            if (response == null) {
                ps = PollStatus.unavailable("server closed connection before banner was recieved.");
            }
        
            if (!regex.match(response)) {
                // Got a response but it didn't match... no need to attempt
                // retries
                LogUtils.debugf(this, "isServer: NON-matching response='%s'", response);
                ps = PollStatus.unavailable("server responded, but banner did not match '" + banner + "'");
            } else {
                LogUtils.debugf(this, "isServer: matching response='%s'", response);
            }
        }
        PollStatus result = ps;
        
        m_isAvailable = result.isAvailable();
    }

    /**
     * <p>receiveBanner</p>
     *
     * @return a {@link org.opennms.netmgt.provision.detector.ssh.response.SshResponse} object.
     * @throws java.io.IOException if any.
     * @throws java.lang.Exception if any.
     */
    public SshResponse receiveBanner() throws IOException, Exception {
        SshResponse response = new SshResponse();
        response.receive(m_isAvailable);
        return response;
    }

    /**
     * <p>sendRequest</p>
     *
     * @param request a {@link org.opennms.netmgt.provision.detector.ssh.request.NullRequest} object.
     * @return a {@link org.opennms.netmgt.provision.detector.ssh.response.SshResponse} object.
     * @throws java.io.IOException if any.
     * @throws java.lang.Exception if any.
     */
    public SshResponse sendRequest(NullRequest request) throws IOException, Exception {
        return null;
    }
    
    /**
     * <p>setBanner</p>
     *
     * @param banner a {@link java.lang.String} object.
     */
    public void setBanner(String banner) {
        m_banner = banner;
    }
    
    /**
     * <p>setMatch</p>
     *
     * @param match a {@link java.lang.String} object.
     */
    public void setMatch(String match) {
        m_match = match;
    }
    
    /**
     * <p>setClientBanner</p>
     *
     * @param clientBanner a {@link java.lang.String} object.
     */
    public void setClientBanner(String clientBanner) {
        m_clientBanner = clientBanner;
    }

}