/*******************************************************************************
* This file is part of OpenNMS(R).
*
* Copyright (C) 2006-2011 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/
* http://www.opennms.com/
*******************************************************************************/
package org.opennms.netmgt.poller.monitors;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.ConnectException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.NoRouteToHostException;
import java.util.Map;
import org.apache.log4j.Level;
import org.opennms.core.utils.ParameterMap;
import org.opennms.core.utils.ThreadCategory;
import org.opennms.core.utils.TimeoutTracker;
import org.opennms.netmgt.model.PollStatus;
import org.opennms.netmgt.poller.Distributable;
import org.opennms.netmgt.poller.MonitoredService;
import org.opennms.netmgt.poller.NetworkInterface;
import org.opennms.netmgt.poller.NetworkInterfaceNotSupportedException;
import org.opennms.protocols.ntp.NtpMessage;
/**
* <P>
* This class is designed to be used by the service poller framework to test the
* availability of the NTP service on remote interfaces. The class implements
* the ServiceMonitor interface that allows it to be used along with other
* plug-ins by the service poller framework.
* </P>
*
* @author <A HREF="mailto:tarus@opennms.org">Tarus Balog </A>
* @author <A HREF="http://www.opennms.org/">OpenNMS </A>
*/
@Distributable
final public class NtpMonitor extends AbstractServiceMonitor {
/**
* Default NTP port.
*/
private static final int DEFAULT_PORT = 123;
/**
* 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 = 5000;
/**
* {@inheritDoc}
*
* <P>
* Poll the specified address for NTP service availability.
* </P>
*
* <P>
* During the poll an NTP request query packet is generated. The query is
* sent via UDP socket to the interface at the specified port (by default
* UDP port 123). If a response is received, it is parsed and validated. If
* the NTP was successful the service status is set to SERVICE_AVAILABLE and
* the method returns.
* </P>
*/
public PollStatus poll(MonitoredService svc, Map<String, Object> parameters) {
NetworkInterface<InetAddress> iface = svc.getNetInterface();
//
// Get interface address from NetworkInterface
//
if (iface.getType() != NetworkInterface.TYPE_INET)
throw new NetworkInterfaceNotSupportedException("Unsupported interface type, only TYPE_INET currently supported");
// get the log
//
ThreadCategory log = ThreadCategory.getInstance(getClass());
// get the parameters
//
TimeoutTracker tracker = new TimeoutTracker(parameters, DEFAULT_RETRY, DEFAULT_TIMEOUT);
int port = ParameterMap.getKeyedInteger(parameters, "port", DEFAULT_PORT);
// get the address and NTP address request
//
InetAddress ipv4Addr = (InetAddress) iface.getAddress();
PollStatus serviceStatus = PollStatus.unavailable();
DatagramSocket socket = null;
double responseTime = -1.0;
try {
socket = new DatagramSocket();
socket.setSoTimeout(tracker.getSoTimeout()); // will force the
// InterruptedIOException
for (tracker.reset(); tracker.shouldRetry() && !serviceStatus.isAvailable(); tracker.nextAttempt()) {
try {
// Send NTP request
//
byte[] data = new NtpMessage().toByteArray();
DatagramPacket outgoing = new DatagramPacket(data, data.length, ipv4Addr, port);
tracker.startAttempt();
socket.send(outgoing);
// Get NTP Response
//
// byte[] buffer = new byte[512];
DatagramPacket incoming = new DatagramPacket(data, data.length);
socket.receive(incoming);
responseTime = tracker.elapsedTimeInMillis();
double destinationTimestamp = (System.currentTimeMillis() / 1000.0) + 2208988800.0;
// Validate NTP Response
// IOException thrown if packet does not decode as expected.
NtpMessage msg = new NtpMessage(incoming.getData());
double localClockOffset = ((msg.receiveTimestamp - msg.originateTimestamp) + (msg.transmitTimestamp - destinationTimestamp)) / 2;
if (log.isDebugEnabled())
log.debug("poll: valid NTP request received the local clock offset is " + localClockOffset + ", responseTime= " + responseTime + "ms");
log.debug("poll: NTP message : " + msg.toString());
serviceStatus = PollStatus.available(responseTime);
} catch (InterruptedIOException ex) {
// Ignore, no response received.
}
}
} catch (NoRouteToHostException e) {
serviceStatus = logDown(Level.DEBUG, "No route to host exception for address: " + ipv4Addr, e);
} catch (ConnectException e) {
serviceStatus = logDown(Level.DEBUG, "Connection exception for address: " + ipv4Addr, e);
} catch (IOException ex) {
serviceStatus = logDown(Level.INFO, "IOException while polling address: " + ipv4Addr, ex);
} finally {
if (socket != null)
socket.close();
}
//
//
// return the status of the service
//
return serviceStatus;
}
}