Java tutorial
/******************************************************************************* * This file is part of OpenNMS(R). * * Copyright (C) 2002-2014 The OpenNMS Group, Inc. * OpenNMS(R) is Copyright (C) 1999-2014 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 Affero 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero 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.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.InterruptedIOException; import java.net.ConnectException; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.NoRouteToHostException; import java.net.Socket; import java.util.Map; import java.util.StringTokenizer; import java.util.regex.Pattern; import java.util.regex.PatternSyntaxException; import org.apache.commons.net.io.CRLFLineReader; import org.opennms.core.utils.InetAddressUtils; import org.opennms.core.utils.ParameterMap; import org.opennms.core.utils.TimeoutTracker; 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.netmgt.poller.PollStatus; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * <P> * This class is designed to be used by the service poller framework to test the * availability of the SMTP 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 public final class SmtpMonitor extends AbstractServiceMonitor { public static final Logger LOG = LoggerFactory.getLogger(SmtpMonitor.class); /** * Default SMTP port. */ private static final int DEFAULT_PORT = 25; /** * 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; /** * The name of the local host. */ private static final String LOCALHOST_NAME = InetAddressUtils.getLocalHostName(); /** * Used to check for a multiline response. A multiline response begins with * the same 3 digit response code, but has a hyphen after the last number * instead of a space. */ private static final Pattern MULTILINE; /** * Init MULTILINE */ static { try { MULTILINE = Pattern.compile("^[0-9]{3}-"); } catch (PatternSyntaxException ex) { throw new java.lang.reflect.UndeclaredThrowableException(ex); } } /** * {@inheritDoc} * * <P> * Poll the specified address for SMTP service availability. * </P> * * <P> * During the poll an attempt is made to connect on the specified port (by * default TCP port 25). If the connection request is successful, the banner * line generated by the interface is parsed and if the extracted return * code indicates that we are talking to an SMTP server we continue. Next, * an SMTP 'HELO' command is sent to the interface. Again the response is * parsed and a return code extracted and verified. Finally, an SMTP 'QUIT' * command is sent. Provided that the interface's response is valid we set * the service status to SERVICE_AVAILABLE and return. * </P> */ @Override 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"); } TimeoutTracker tracker = new TimeoutTracker(parameters, DEFAULT_RETRY, DEFAULT_TIMEOUT); int port = ParameterMap.getKeyedInteger(parameters, "port", DEFAULT_PORT); // Get interface address from NetworkInterface // InetAddress ipAddr = iface.getAddress(); final String hostAddress = InetAddressUtils.str(ipAddr); LOG.debug("poll: address = {}, port = {}, {}", hostAddress, port, tracker); PollStatus serviceStatus = PollStatus.unavailable(); for (tracker.reset(); tracker.shouldRetry() && !serviceStatus.isAvailable(); tracker.nextAttempt()) { Socket socket = null; try { // create a connected socket // tracker.startAttempt(); socket = new Socket(); socket.connect(new InetSocketAddress(ipAddr, port), tracker.getConnectionTimeout()); socket.setSoTimeout(tracker.getSoTimeout()); LOG.debug("SmtpMonitor: connected to host: {} on port: {}", ipAddr, port); // We're connected, so upgrade status to unresponsive serviceStatus = PollStatus.unresponsive(); // Forcing to check for CRLF instead of any other line terminator as per RFC specification CRLFLineReader rdr = new CRLFLineReader(new InputStreamReader(socket.getInputStream(), "ASCII")); // // Tokenize the Banner Line, and check the first // line for a valid return. // String banner = sendMessage(socket, rdr, null); LOG.debug("poll: banner = {}", banner); StringTokenizer t = new StringTokenizer(banner); int rc = Integer.parseInt(t.nextToken()); if (rc == 220) { // // Send the HELO command // String cmd = "HELO " + LOCALHOST_NAME + "\r\n"; socket.getOutputStream().write(cmd.getBytes()); // // get the returned string, tokenize, and // verify the correct output. // String response = rdr.readLine(); double responseTime = tracker.elapsedTimeInMillis(); if (response == null) { continue; } if (MULTILINE.matcher(response).find()) { // Ok we have a multi-line response...first three // chars of the response line are the return code. // The last line of the response will start with // return code followed by a space. String multiLineRC = new String(response.getBytes("ASCII"), 0, 3, "ASCII"); // Create new regExp to look for last line // of this multi line response Pattern endMultiline = null; try { endMultiline = Pattern.compile(multiLineRC); } catch (PatternSyntaxException ex) { throw new java.lang.reflect.UndeclaredThrowableException(ex); } // read until we hit the last line of the multi-line // response do { response = rdr.readLine(); } while (response != null && !endMultiline.matcher(response).find()); if (response == null) { continue; } } t = new StringTokenizer(response); rc = Integer.parseInt(t.nextToken()); if (rc == 250) { response = sendMessage(socket, rdr, "QUIT\r\n"); t = new StringTokenizer(response); rc = Integer.parseInt(t.nextToken()); if (rc == 221) { serviceStatus = PollStatus.available(responseTime); } } } else if (rc == 554) { String response = sendMessage(socket, rdr, "QUIT\r\n"); serviceStatus = PollStatus.unavailable("Server rejecting transactions with 554"); } // If we get this far and the status has not been set to // available, then something didn't verify during the banner // checking or HELO/QUIT comand process. if (!serviceStatus.isAvailable()) { serviceStatus = PollStatus.unavailable(serviceStatus.getReason()); } } catch (NumberFormatException e) { String reason = "NumberFormatException while polling address " + hostAddress; LOG.debug(reason, e); serviceStatus = PollStatus.unavailable(reason); } catch (NoRouteToHostException e) { String reason = "No route to host exception for address " + hostAddress; LOG.debug(reason, e); serviceStatus = PollStatus.unavailable(reason); break; // Break out of for(;;) } catch (InterruptedIOException e) { String reason = "Did not receive expected response within timeout " + tracker; LOG.debug(reason); serviceStatus = PollStatus.unavailable(reason); } catch (ConnectException e) { String reason = "Unable to connect to address " + hostAddress; LOG.debug(reason, e); serviceStatus = PollStatus.unavailable(reason); } catch (IOException e) { String reason = "IOException while polling address " + hostAddress; LOG.debug(reason, e); serviceStatus = PollStatus.unavailable(reason); } finally { try { // Close the socket if (socket != null) { socket.close(); } } catch (IOException e) { e.fillInStackTrace(); LOG.debug("poll: Error closing socket.", e); } } } // // return the status of the service // return serviceStatus; } private String sendMessage(Socket socket, BufferedReader rdr, String command) throws IOException { if (command != null && !"".equals(command)) { socket.getOutputStream().write(command.getBytes("ASCII")); } // // get the returned string, tokenize, and // verify the correct output. // String response = rdr.readLine(); if (response == null) { return ""; } if (MULTILINE.matcher(response).find()) { // Ok we have a multi-line response...first three // chars of the response line are the return code. // The last line of the response will start with // return code followed by a space. String multiLineRC = new String(response.getBytes("ASCII"), 0, 3, "ASCII") + " "; // Create new regExp to look for last line // of this multi line response Pattern endMultiline = null; try { endMultiline = Pattern.compile(multiLineRC); } catch (PatternSyntaxException ex) { throw new java.lang.reflect.UndeclaredThrowableException(ex); } // read until we hit the last line of the multi-line // response do { response = rdr.readLine(); } while (response != null && !endMultiline.matcher(response).find()); if (response == null) { return ""; } } return response; } }