/*

 * Copyright (c) 2007, 2018, 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 java.net;

import java.io.IOException;

import jdk.internal.access.SharedSecrets;

import jdk.internal.access.JavaIOFileDescriptorAccess;

/**

 * This class defines the plain DatagramSocketImpl that is used on

 * Windows platforms greater than or equal to Windows Vista. These

 * platforms have a dual layer TCP/IP stack and can handle both IPv4

 * and IPV6 through a single file descriptor.

 * <p>

 * Note: Multicasting on a dual layer TCP/IP stack is always done with

 * TwoStacksPlainDatagramSocketImpl. This is to overcome the lack

 * of behavior defined for multicasting over a dual layer socket by the RFC.

 *

 * @author Chris Hegarty

 */

class DualStackPlainDatagramSocketImpl extends AbstractPlainDatagramSocketImpl

{

    static JavaIOFileDescriptorAccess fdAccess = SharedSecrets.getJavaIOFileDescriptorAccess();

    static {

        initIDs();

    }

    // true if this socket is exclusively bound

    private final boolean exclusiveBind;

    /*

     * Set to true if SO_REUSEADDR is set after the socket is bound to

     * indicate SO_REUSEADDR is being emulated

     */

    private boolean reuseAddressEmulated;

    // emulates SO_REUSEADDR when exclusiveBind is true and socket is bound

    private boolean isReuseAddress;

    DualStackPlainDatagramSocketImpl(boolean exclBind) {

        exclusiveBind = exclBind;

    }

    protected void datagramSocketCreate() throws SocketException {

        if (fd == null)

            throw new SocketException("Socket closed");

        int newfd = socketCreate();

        fdAccess.set(fd, newfd);

    }

    protected synchronized void bind0(int lport, InetAddress laddr)

        throws SocketException {

        int nativefd = checkAndReturnNativeFD();

        if (laddr == null)

            throw new NullPointerException("argument address");

        socketBind(nativefd, laddr, lport, exclusiveBind);

        if (lport == 0) {

            localPort = socketLocalPort(nativefd);

        } else {

            localPort = lport;

        }

    }

    protected synchronized int peek(InetAddress address) throws IOException {

        int nativefd = checkAndReturnNativeFD();

        if (address == null)

            throw new NullPointerException("Null address in peek()");

        // Use peekData()

        DatagramPacket peekPacket = new DatagramPacket(new byte[1], 1);

        int peekPort = peekData(peekPacket);

        address = peekPacket.getAddress();

        return peekPort;

    }

    protected synchronized int peekData(DatagramPacket p) throws IOException {

        int nativefd = checkAndReturnNativeFD();

        if (p == null)

            throw new NullPointerException("packet");

        if (p.getData() == null)

            throw new NullPointerException("packet buffer");

        return socketReceiveOrPeekData(nativefd, p, timeout, connected, true /*peek*/);

    }

    protected synchronized void receive0(DatagramPacket p) throws IOException {

        int nativefd = checkAndReturnNativeFD();

        if (p == null)

            throw new NullPointerException("packet");

        if (p.getData() == null)

            throw new NullPointerException("packet buffer");

        socketReceiveOrPeekData(nativefd, p, timeout, connected, false /*receive*/);

    }

        int nativefd = checkAndReturnNativeFD();

        if (p == null)

            throw new NullPointerException("null packet");

        if (p.getAddress() == null ||p.getData() ==null)

            throw new NullPointerException("null address || null buffer");

        socketSend(nativefd, p.getData(), p.getOffset(), p.getLength(),

                   p.getAddress(), p.getPort(), connected);

    }

    protected void connect0(InetAddress address, int port) throws SocketException {

        int nativefd = checkAndReturnNativeFD();

        if (address == null)

            throw new NullPointerException("address");

        socketConnect(nativefd, address, port);

    }

    protected void disconnect0(int family /*unused*/) {

        if (fd == null || !fd.valid())

            return;   // disconnect doesn't throw any exceptions

        socketDisconnect(fdAccess.get(fd));

    }

    protected void datagramSocketClose() {

        if (fd == null || !fd.valid())

            return;   // close doesn't throw any exceptions

        socketClose(fdAccess.get(fd));

        fdAccess.set(fd, -1);

    }

    @SuppressWarnings("fallthrough")

    protected void socketSetOption(int opt, Object val) throws SocketException {

        int nativefd = checkAndReturnNativeFD();

        int optionValue = 0;

        // SO_REUSEPORT is not supported on Windows.

        if (opt == SO_REUSEPORT) {

            throw new UnsupportedOperationException("unsupported option");

        }

        switch(opt) {

            case IP_TOS :

            case SO_RCVBUF :

            case SO_SNDBUF :

                optionValue = ((Integer)val).intValue();

                break;

            case SO_REUSEADDR :

                if (exclusiveBind && localPort != 0)  {

                    // socket already bound, emulate SO_REUSEADDR

                    reuseAddressEmulated = true;

                    isReuseAddress = (Boolean)val;

                    return;

                }

                //Intentional fallthrough

            case SO_BROADCAST :

                optionValue = ((Boolean)val).booleanValue() ? 1 : 0;

                break;

            default: /* shouldn't get here */

                throw new SocketException("Option not supported");

        }

        socketSetIntOption(nativefd, opt, optionValue);

    }

    protected Object socketGetOption(int opt) throws SocketException {

        int nativefd = checkAndReturnNativeFD();

         // SO_BINDADDR is not a socket option.

        if (opt == SO_BINDADDR) {

            return socketLocalAddress(nativefd);

        }

        if (opt == SO_REUSEADDR && reuseAddressEmulated)

            return isReuseAddress;

        // SO_REUSEPORT is not supported on Windows.

        if (opt == SO_REUSEPORT)

            throw new UnsupportedOperationException("unsupported option");

        int value = socketGetIntOption(nativefd, opt);

        Object returnValue = null;

        switch (opt) {

            case SO_REUSEADDR :

            case SO_BROADCAST :

                returnValue =  (value == 0) ? Boolean.FALSE : Boolean.TRUE;

                break;

            case IP_TOS :

            case SO_RCVBUF :

            case SO_SNDBUF :

                returnValue = Integer.valueOf(value);

                break;

            default: /* shouldn't get here */

                throw new SocketException("Option not supported");

        }

        return returnValue;

    }

    /* Multicast specific methods.

     * Multicasting on a dual layer TCP/IP stack is always done with

     * TwoStacksPlainDatagramSocketImpl. This is to overcome the lack

     * of behavior defined for multicasting over a dual layer socket by the RFC.

     */

    protected void join(InetAddress inetaddr, NetworkInterface netIf)

        throws IOException {

        throw new IOException("Method not implemented!");

    }

    protected void leave(InetAddress inetaddr, NetworkInterface netIf)

        throws IOException {

        throw new IOException("Method not implemented!");

    }

    protected void setTimeToLive(int ttl) throws IOException {

        throw new IOException("Method not implemented!");

    }

    protected int getTimeToLive() throws IOException {

        throw new IOException("Method not implemented!");

    }

    @Deprecated

    protected void setTTL(byte ttl) throws IOException {

        throw new IOException("Method not implemented!");

    }

    @Deprecated

    protected byte getTTL() throws IOException {

        throw new IOException("Method not implemented!");

    }

    /* END Multicast specific methods */

    private int checkAndReturnNativeFD() throws SocketException {

        if (fd == null || !fd.valid())

            throw new SocketException("Socket closed");

        return fdAccess.get(fd);

    }

    /* Native methods */

    private static native void initIDs();

    private static native int socketCreate();

    private static native void socketBind(int fd, InetAddress localAddress,

            int localport, boolean exclBind) throws SocketException;

    private static native void socketConnect(int fd, InetAddress address, int port)

        throws SocketException;

    private static native void socketDisconnect(int fd);

    private static native void socketClose(int fd);

    private static native int socketLocalPort(int fd) throws SocketException;

    private static native Object socketLocalAddress(int fd) throws SocketException;

    private static native int socketReceiveOrPeekData(int fd, DatagramPacket packet,

        int timeout, boolean connected, boolean peek) throws IOException;

    private static native void socketSend(int fd, byte[] data, int offset, int length,

        InetAddress address, int port, boolean connected) throws IOException;

    private static native void socketSetIntOption(int fd, int cmd,

        int optionValue) throws SocketException;

    private static native int socketGetIntOption(int fd, int cmd) throws SocketException;

    native int dataAvailable();

}