dhcpmonitor.java

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//
// This file is part of the OpenNMS(R) Application.
//
// OpenNMS(R) is Copyright (C) 2002-2003 The OpenNMS Group, Inc.  All rights reserved.
// OpenNMS(R) is a derivative work, containing both original code, included code and modified
// code that was published under the GNU General Public License. Copyrights for modified 
// and included code are below.
//
// OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
//
// Modifications:
//
// 2003 Jun 11: Added a "catch" for RRD update errors. Bug #748.
// 2003 Jan 31: Added the ability to imbed RRA information in poller packages.
// 2002 Nov 14: Used non-blocking I/O socket channel classes.
// 2002 Nov 12: Added web based reports for DHCP monitor.
//
// Original code base Copyright (C) 1999-2001 Oculan Corp.  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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// For more information contact:
//      OpenNMS Licensing       <[e-mail]>
//      http://www.opennms.org/
//      http://www.opennms.com/
//
// Tab Size = 8
//

package org.opennms.netmgt.poller.monitors;

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

import org.apache.log4j.Category;
import org.opennms.core.utils.ThreadCategory;
import org.opennms.netmgt.dhcpd.Dhcpd;
import org.opennms.netmgt.utils.ParameterMap;

/**
 * This class is designed to be used by the service poller framework to test the
 * availability of the DHCP service on remote interfaces as defined by RFC 2131.
 * 
 * This class relies on the DHCP API provided by JDHCP v1.1.1 (please refer to
 * <A HREF="http://www.dhcp.org/javadhcp">http://www.dhcp.org/javadhcp </A>).
 * 
 * The class implements the ServiceMonitor interface that allows it to be used
 * along with other plug-ins by the service poller framework.
 * 
 * @author <A HREF="mailto:[e-mail]">Tarus Balog </A>
 * @author <A HREF="http://www.opennms.org/">OpenNMS </A>
 * 
 */
final public class DhcpMonitor extends IPv4LatencyMonitor {
    /**
     * Default retries.
     */
    private static final int DEFAULT_RETRY = 0;

    /**
     * Default timeout. Specifies how long (in milliseconds) to block waiting
     * for data from the monitored interface.
     */
    private static final int DEFAULT_TIMEOUT = 3000; // 3 second timeout on
                                                        // read()

    /**
     * Poll the specified address for DHCP service availability.
     * 
     * @param iface
     *            The network interface to test the service on.
     * @param parameters
     *            The package parameters (timeout, retry, etc...) to be used for
     *            this poll.
     * 
     * @return The availability of the interface and if a transition event
     *         should be supressed.
     * 
     */
    public int poll(NetworkInterface iface, Map parameters, org.opennms.netmgt.config.poller.Package pkg) {
        // Get interface address from NetworkInterface
        //
        if (iface.getType() != NetworkInterface.TYPE_IPV4)
            throw new NetworkInterfaceNotSupportedException("Unsupported interface type, only TYPE_IPV4 currently supported");

        // Process parameters
        //
        Category log = ThreadCategory.getInstance(getClass());

        // Retries
        //
        int retry = ParameterMap.getKeyedInteger(parameters, "retry", DEFAULT_RETRY);
        int timeout = ParameterMap.getKeyedInteger(parameters, "timeout", DEFAULT_TIMEOUT);
        String rrdPath = ParameterMap.getKeyedString(parameters, "rrd-repository", null);
        String dsName = ParameterMap.getKeyedString(parameters, "ds-name", null);

        if (rrdPath == null) {
            log.info("poll: RRD repository not specified in parameters, latency data will not be stored.");
        }

        if (dsName == null) {
            dsName = DS_NAME;
        }

        // Get interface address from NetworkInterface
        //
        InetAddress ipv4Addr = (InetAddress) iface.getAddress();

        if (log.isDebugEnabled())
            log.debug("DhcpMonitor.poll: address: " + ipv4Addr + " timeout: " + timeout + " retry: " + retry);

        int serviceStatus = ServiceMonitor.SERVICE_UNAVAILABLE;
        long responseTime = -1;
        try {
            // Dhcpd.isServer() returns the response time in milliseconds
            // if the remote box is a DHCP server or -1 if the remote
            // box is NOT a DHCP server.
            // 
            responseTime = Dhcpd.isServer(ipv4Addr, (long) timeout, retry);
            if (responseTime >= 0) {
                serviceStatus = ServiceMonitor.SERVICE_AVAILABLE;
            }
        } catch (IOException ioE) {
            ioE.fillInStackTrace();
            log.warn("DhcpMonitor.poll: An I/O exception occured during DHCP discovery", ioE);
        }

        // Store response time if available
        //
        if (serviceStatus == ServiceMonitor.SERVICE_AVAILABLE) {
            // Store response time in RRD
            if (responseTime >= 0 && rrdPath != null) {
                try {
                    this.updateRRD(rrdPath, ipv4Addr, dsName, responseTime, pkg);
                } catch (RuntimeException rex) {
                    log.debug("There was a problem writing the RRD:" + rex);
                }
            }
        }

        //
        // return the status of the service
        //
        return serviceStatus;
    }
}