de.esukom.decoit.ifmapclient.iptables.RulesExecutor.java Source code

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Here is the source code for de.esukom.decoit.ifmapclient.iptables.RulesExecutor.java

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/* 
 * RulesExecutor.java        0.1.4 12/02/16
 * 
 * DEVELOPED BY DECOIT GMBH WITHIN THE ESUKOM-PROJECT:
 * http://www.decoit.de/
 * http://www.esukom.de/cms/front_content.php?idcat=10&lang=1
 * 
 * DERIVED FROM  THE DHCP-IFMAP-CLIENT-IMPLEMENTATION DEVELOPED BY 
 * FHH/TRUST WITHIN THE IRON-PROJECT:
 * http://trust.inform.fh-hannover.de/joomla/
 * 
 * Licensed to the Apache Software Foundation (ASF) under one 
 * or more contributor license agreements.  See the NOTICE file 
 * distributed with this work for additional information 
 * regarding copyright ownership.  The ASF licenses this file 
 * to you under the Apache License, Version 2.0 (the 
 * "License"); you may not use this file except in compliance 
 * with the License.  You may obtain a copy of the License at 
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0 
 * 
 * Unless required by applicable law or agreed to in writing, 
 * software distributed under the License is distributed on an 
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 
 * KIND, either express or implied.  See the License for the 
 * specific language governing permissions and limitations 
 * under the License. 
 */

package de.esukom.decoit.ifmapclient.iptables;

import de.esukom.decoit.ifmapclient.main.IfMapClient;

import org.apache.commons.exec.CommandLine;
import org.apache.commons.exec.DefaultExecuteResultHandler;
import org.apache.commons.exec.DefaultExecutor;
import org.apache.commons.exec.ExecuteException;
import org.apache.commons.exec.ExecuteWatchdog;
import org.apache.commons.exec.Executor;

import java.io.IOException;

/**
 * Singleton for executing ip-tables commands using the apache-commons-exec
 * library
 * 
 * @version 0.1.4
 * @author Dennis Dunekacke, DECOIT GmbH
 */
public class RulesExecutor {

    // predefined exit code
    public static final int EXIT_CODE_SUCCESS = 0;
    public static final int EXIT_CODE_ERROR = 1;

    // Singleton
    private static RulesExecutor sInstance;

    // ip-tables command
    public final String command = "/sbin/iptables";

    // timeout for execution
    private int mTimeout = 60000;

    private RulesExecutor() {
    }

    public synchronized static RulesExecutor getInstance() {
        if (sInstance == null) {
            sInstance = new RulesExecutor();
        }
        return sInstance;
    }

    public boolean executePredefinedRule(byte ruleType, String[] arg) {
        IfMapClient.LOGGER.info("[IPTABLES] -> executing predefined command...");

        // use apache's commons-exec for executing command!
        CommandLine cmdLine = new CommandLine(command);

        // get the predefined rule-parameters
        String[] ruleParams = Rules.getPredefindedRuleParameters(ruleType, arg);

        if (ruleParams != null) {

            // add rule-parameters to CommanLine-Object
            for (int i = 0; i < ruleParams.length; i++) {
                cmdLine.addArgument(ruleParams[i]);
            }

            // execute command
            DefaultExecuteResultHandler resultHandler = new DefaultExecuteResultHandler();
            ExecuteWatchdog watchdog = new ExecuteWatchdog(mTimeout);
            Executor executor = new DefaultExecutor();
            executor.setExitValue(1);
            executor.setWatchdog(watchdog);
            try {
                executor.execute(cmdLine, resultHandler);
            } catch (ExecuteException e) {
                IfMapClient.LOGGER.warning(
                        "[IPTABLES] -> error while executing predefined command: execute-exception occured!");
                return false;
            } catch (IOException e) {
                IfMapClient.LOGGER
                        .warning("[IPTABLES] -> error while executing predefined command: io-exception occured!");
                return false;
            }

            try {
                // some time later the result handler callback was invoked so we
                // can safely request the exit value
                resultHandler.waitFor();
                int exitCode = resultHandler.getExitValue();
                IfMapClient.LOGGER.warning("[IPTABLES] -> command executed, exit-code is: " + exitCode);

                switch (exitCode) {
                case EXIT_CODE_SUCCESS:
                    return true;
                case EXIT_CODE_ERROR:
                    return false;
                default:
                    return false;
                }

            } catch (InterruptedException e) {
                IfMapClient.LOGGER.warning(
                        "[IPTABLES] -> error while executing predefined command: interrupted-exception occured!");
                return false;
            }

        } else {
            IfMapClient.LOGGER.warning(
                    "[IPTABLES] -> error while excuting predefined command: rule-parameters-list is null!");
            return false;
        }
    }
}