/* * Copyright (c) 2007, 2008, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.management.jmxremote; import java.io.IOException;import java.net.InetAddress;import java.net.NetworkInterface;import java.net.ServerSocket;import java.net.Socket;import java.net.SocketException;import java.rmi.server.RMIServerSocketFactory;import java.util.Enumeration; /** * This RMI server socket factory creates server sockets that * will only accept connection requests from clients running * on the host where the RMI remote objects have been exported. */public final class LocalRMIServerSocketFactory implements RMIServerSocketFactory {    /**     * Creates a server socket that only accepts connection requests from     * clients running on the host where the RMI remote objects have been     * exported.     */    public ServerSocket createServerSocket(int port) throws IOException {        return new ServerSocket(port) {            @Override            public Socket accept() throws IOException {                final Socket socket = super.accept();                final InetAddress remoteAddr = socket.getInetAddress();                final String msg = "The server sockets created using the " +                       "LocalRMIServerSocketFactory only accept connections " +                       "from clients running on the host where the RMI " +                       "remote objects have been exported.";                 if (remoteAddr == null) {                    // Though unlikeky, the socket could be already                    // closed... Send a more detailed message in                    // this case. Also avoid throwing NullPointerExceptiion                    //                    String details = "";                    if (socket.isClosed()) {                        details = " Socket is closed.";                    } else if (!socket.isConnected()) {                        details = " Socket is not connected";                    }                    try {                        socket.close();                    } catch (Exception ok) {                        // ok - this is just cleanup before throwing detailed                        // exception.                    }                    throw new IOException(msg +                            " Couldn't determine client address." +                            details);                } else if (remoteAddr.isLoopbackAddress()) {                    // local address: accept the connection.                    return socket;                }                // Retrieve all the network interfaces on this host.                Enumeration<NetworkInterface> nis;                try {                    nis = NetworkInterface.getNetworkInterfaces();                } catch (SocketException e) {                    try {                        socket.close();                    } catch (IOException ioe) {                        // Ignore...                    }                    throw new IOException(msg, e);                }                // Walk through the network interfaces to see                // if any of them matches the client's address.                // If true, then the client's address is local.                while (nis.hasMoreElements()) {                    NetworkInterface ni = nis.nextElement();                    Enumeration<InetAddress> addrs = ni.getInetAddresses();                    while (addrs.hasMoreElements()) {                        InetAddress localAddr = addrs.nextElement();                        if (localAddr.equals(remoteAddr)) {                            return socket;                        }                    }                }                // The client's address is remote so refuse the connection.                try {                    socket.close();                } catch (IOException ioe) {                    // Ignore...                }                throw new IOException(msg);            }        };    }     /**     * Two LocalRMIServerSocketFactory objects     * are equal if they are of the same type.     */    @Override    public boolean equals(Object obj) {        return (obj instanceof LocalRMIServerSocketFactory);    }     /**     * Returns a hash code value for this LocalRMIServerSocketFactory.     */    @Override    public int hashCode() {        return getClass().hashCode();    }}