org.apache.hadoop.hdfs.DnsMonitorSecurityManager.java Source code

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Here is the source code for org.apache.hadoop.hdfs.DnsMonitorSecurityManager.java

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/**
 * 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 org.apache.hadoop.hdfs;

import java.io.FileDescriptor;
import java.net.InetAddress;
import java.security.Permission;
import java.util.HashSet;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * 
 * A SecurityManager that logs DNS resolution call's stack traces.
 * 
 */
public class DnsMonitorSecurityManager extends SecurityManager {
    private static final Log LOG = LogFactory.getLog(DnsMonitorSecurityManager.class);
    private final Set<Integer> cacheOfHashOfSeenStackTraces = new HashSet<Integer>();
    private static final String ACTIVATE_FLAG = "dns_call_stack_logging";
    private static final DnsMonitorSecurityManager theManager = new DnsMonitorSecurityManager();

    /**
     * Update's the system's security manager to an instance of this class if
     * system property dns_call_stack_logging is set to true.
     */
    public static void setTheManager() {
        if ("true".equalsIgnoreCase(System.getProperty(ACTIVATE_FLAG))) {
            if (!(System.getSecurityManager() instanceof DnsMonitorSecurityManager)) {
                System.setSecurityManager(theManager);
            }
        }
    }

    /**
     * Private in order to enforce use of {@link #setTheManager()} and check
     * System's property check of {@value #ACTIVATE_FLAG}
     */
    private DnsMonitorSecurityManager() {
    }

    @Override
    public void checkConnect(String host, int port) {
        final String stackTrace = DFSUtil.getStackTrace();
        if (!stackTrace.contains(InetAddress.class.getName())) {
            return;
        }
        final int hashCodeOfStackTrace = stackTrace.hashCode();
        boolean toLogThisStackTrace = false;
        synchronized (cacheOfHashOfSeenStackTraces) {
            if (!cacheOfHashOfSeenStackTraces.contains(hashCodeOfStackTrace)) {
                cacheOfHashOfSeenStackTraces.add(hashCodeOfStackTrace);
                toLogThisStackTrace = true;
            }
        }
        if (toLogThisStackTrace) {
            LOG.info("checkConnect(host=" + host + ", port=" + port + ")");
            LOG.info(stackTrace);
        }
    }

    @Override
    public void checkConnect(String host, int port, Object context) {
        this.checkConnect(host, port);
    }

    @Override
    public void checkAccept(String host, int port) {
    }

    @Override
    public void checkAccess(Thread t) {
    }

    @Override
    public void checkAccess(ThreadGroup g) {
    }

    @Override
    public void checkAwtEventQueueAccess() {
    }

    @Override
    public void checkCreateClassLoader() {
    }

    @Override
    public void checkDelete(String file) {
    }

    @Override
    public void checkExec(String cmd) {
    }

    @Override
    public void checkExit(int status) {
    }

    @Override
    public void checkLink(String lib) {
    }

    @Override
    public void checkListen(int port) {
    }

    @Override
    public void checkMemberAccess(Class<?> clazz, int which) {
    }

    @Override
    public void checkMulticast(InetAddress maddr) {
    }

    @Override
    public void checkMulticast(InetAddress maddr, byte ttl) {
    }

    @Override
    public void checkPackageAccess(String pkg) {
    }

    @Override
    public void checkPackageDefinition(String pkg) {
    }

    @Override
    public void checkPermission(Permission p) {
    }

    @Override
    public void checkPermission(Permission p, Object o) {
    }

    @Override
    public void checkPropertyAccess(String s) {
    }

    @Override
    public void checkPropertiesAccess() {
    }

    @Override
    public void checkPrintJobAccess() {
    }

    @Override
    public void checkRead(FileDescriptor fd) {
    }

    @Override
    public void checkRead(String file) {
    }

    @Override
    public void checkRead(String file, Object context) {
    }

    @Override
    public void checkSecurityAccess(String target) {
    }

    @Override
    public void checkSetFactory() {
    }

    @Override
    public void checkSystemClipboardAccess() {
    }

    @Override
    public void checkWrite(FileDescriptor fd) {
    }

    @Override
    public void checkWrite(String file) {
    }
}