ape.ForkBombCommand.java Source code

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Here is the source code for ape.ForkBombCommand.java

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/**
  * Copyright (c) 2012 Yahoo! Inc. All rights reserved.
  * Licensed 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. See accompanying LICENSE file.
*/

package ape;

import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.cli.Option;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.ParseException;

/**
 * This command will execute a forkbomb on a host. The forkbomb itself is forked 
 * to the background so the command is not running while the forkbomb propagates.
 * 
 * Essentially, the following is executed in a bash shell on the host:
 * :(){ :|: & };:& 
 * 
 * This consumes all of the process IDs on the host and if no ulimit is set, it 
 * will continue forever which will slow the system to a crawl.  You can check
 * to see if ulimits are set by typing "ulimit -a" in a bash shell on the host.
 * 
 *
 */
public class ForkBombCommand extends ApeCommand {
    private Option option;

    /**
     * The constructor for this command simply creates its Option object (used by
     * the CLI parser)
     */
    public ForkBombCommand() {
        option = OptionBuilder.withValueSeparator().withDescription("Hangs a host by executing a fork bomb")
                .withLongOpt("forkbomb").create("F");
    }

    public String getName() {
        return option.getLongOpt();
    }

    public Option getOption() {
        return option;
    }

    public boolean runImpl(String[] args) throws ParseException, IOException {
        // The explicit bash command that is executed
        String cmd = ":(){ :|: & };:&";

        ProcessBuilder pb = new ProcessBuilder("bash", "-c", cmd);
        pb.redirectErrorStream(true);
        Process sh = pb.start();
        InputStream shIn = sh.getInputStream();
        try {
            if (sh.waitFor() != 0) {
                System.err.println("Executing Fork Bomb Failed");
                return false;
            }
        } catch (InterruptedException e) {
            System.out.println("The fork command received an Interrupt.");
            e.printStackTrace();
            return false;
        }
        int c;
        while ((c = shIn.read()) != -1) {
            System.out.write(c);
        }
        try {
            shIn.close();
        } catch (IOException e) {
            System.out.println("Could not close InputStream from the forkbomb process.");
            e.printStackTrace();
            return false;
        }
        return true;
    }
}