SocketUtils.java — netty Source File

Source Code

/*
 * Copyright 2016 The Netty Project
 *
 * The Netty Project 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:
 *
 *   https://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 io.netty.util.internal;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.SocketException;
import java.net.SocketPermission;
import java.net.UnknownHostException;
import java.nio.channels.DatagramChannel;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Collections;
import java.util.Enumeration;

/**
 * Provides socket operations with privileges enabled. This is necessary for applications that use the
 * {@link SecurityManager} to restrict {@link SocketPermission} to their application. By asserting that these
 * operations are privileged, the operations can proceed even if some code in the calling chain lacks the appropriate
 * {@link SocketPermission}.
 */
public final class SocketUtils {

    private static final Enumeration<Object> EMPTY = Collections.enumeration(Collections.emptyList());

    private SocketUtils() {
    }

    @SuppressWarnings("unchecked")
    private static <T> Enumeration<T> empty() {
        return (Enumeration<T>) EMPTY;
    }

    public static void connect(final Socket socket, final SocketAddress remoteAddress, final int timeout)
            throws IOException {
        try {
            AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() {
                @Override
// ... (163 more lines)