/*

 * Copyright (c) 2007, 2016, 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 java.io.FileDescriptor;

import jdk.internal.misc.SharedSecrets;

import jdk.internal.misc.JavaIOFileDescriptorAccess;

/**

 * This class defines the plain SocketImpl that is used on Windows platforms

 * greater 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.

 *

 * @author Chris Hegarty

 */

class DualStackPlainSocketImpl extends AbstractPlainSocketImpl

{

    static JavaIOFileDescriptorAccess fdAccess = SharedSecrets.getJavaIOFileDescriptorAccess();

    // true if this socket is exclusively bound

    private final boolean exclusiveBind;

    // emulates SO_REUSEADDR when exclusiveBind is true

    private boolean isReuseAddress;

    public DualStackPlainSocketImpl(boolean exclBind) {

        exclusiveBind = exclBind;

    }

    public DualStackPlainSocketImpl(FileDescriptor fd, boolean exclBind) {

        this.fd = fd;

        exclusiveBind = exclBind;

    }

    void socketCreate(boolean stream) throws IOException {

        if (fd == null)

            throw new SocketException("Socket closed");

        int newfd = socket0(stream, false /*v6 Only*/);

        fdAccess.set(fd, newfd);

    }

    void socketConnect(InetAddress address, int port, int timeout)

        throws IOException {

        int nativefd = checkAndReturnNativeFD();

        if (address == null)

            throw new NullPointerException("inet address argument is null.");

        int connectResult;

        if (timeout <= 0) {

            connectResult = connect0(nativefd, address, port);

        } else {

            configureBlocking(nativefd, false);

            try {

                connectResult = connect0(nativefd, address, port);

                if (connectResult == WOULDBLOCK) {

                    waitForConnect(nativefd, timeout);

                }

            } finally {

                configureBlocking(nativefd, true);

            }

        }

        /*

         * We need to set the local port field. If bind was called

         * previous to the connect (by the client) then localport field

         * will already be set.

         */

        if (localport == 0)

            localport = localPort0(nativefd);

    }

    void socketBind(InetAddress address, int port) throws IOException {

        int nativefd = checkAndReturnNativeFD();

        if (address == null)

            throw new NullPointerException("inet address argument is null.");

        bind0(nativefd, address, port, exclusiveBind);

        if (port == 0) {

            localport = localPort0(nativefd);

        } else {

            localport = port;

        }

        this.address = address;

    }

    void socketListen(int backlog) throws IOException {

        int nativefd = checkAndReturnNativeFD();

        listen0(nativefd, backlog);

    }

    void socketAccept(SocketImpl s) throws IOException {

        int nativefd = checkAndReturnNativeFD();

        if (s == null)

            throw new NullPointerException("socket is null");

        int newfd = -1;

        InetSocketAddress[] isaa = new InetSocketAddress[1];

        if (timeout <= 0) {

            newfd = accept0(nativefd, isaa);

        } else {

            configureBlocking(nativefd, false);

            try {

                waitForNewConnection(nativefd, timeout);

                newfd = accept0(nativefd, isaa);

                if (newfd != -1) {

                    configureBlocking(newfd, true);

                }

            } finally {

                configureBlocking(nativefd, true);

            }

        }

        /* Update (SocketImpl)s' fd */

        fdAccess.set(s.fd, newfd);

        /* Update socketImpls remote port, address and localport */

        InetSocketAddress isa = isaa[0];

        s.port = isa.getPort();

        s.address = isa.getAddress();

        s.localport = localport;

    }

    int socketAvailable() throws IOException {

        int nativefd = checkAndReturnNativeFD();

        return available0(nativefd);

    }

    void socketClose0(boolean useDeferredClose/*unused*/) throws IOException {

        if (fd == null)

            throw new SocketException("Socket closed");

        if (!fd.valid())

            return;

        final int nativefd = fdAccess.get(fd);

        fdAccess.set(fd, -1);

        close0(nativefd);

    }

    void socketShutdown(int howto) throws IOException {

        int nativefd = checkAndReturnNativeFD();

        shutdown0(nativefd, howto);

    }

    // Intentional fallthrough after SO_REUSEADDR

    @SuppressWarnings("fallthrough")

    void socketSetOption(int opt, boolean on, Object value)

        throws SocketException {

        int nativefd = checkAndReturnNativeFD();

        if (opt == SO_TIMEOUT) {  // timeout implemented through select.

            return;

        }

        // SO_REUSEPORT is not supported on Windows.

        if (opt == SO_REUSEPORT) {

            throw new UnsupportedOperationException("unsupported option");

        }

        int optionValue = 0;

        switch(opt) {

            case SO_REUSEADDR :

                if (exclusiveBind) {

                    // SO_REUSEADDR emulated when using exclusive bind

                    isReuseAddress = on;

                    return;

                }

                // intentional fallthrough

            case TCP_NODELAY :

            case SO_OOBINLINE :

            case SO_KEEPALIVE :

                optionValue = on ? 1 : 0;

                break;

            case SO_SNDBUF :

            case SO_RCVBUF :

            case IP_TOS :

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

                break;

            case SO_LINGER :

                if (on) {

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

                } else {

                    optionValue = -1;

                }

                break;

            default :/* shouldn't get here */

                throw new SocketException("Option not supported");

        }

        setIntOption(nativefd, opt, optionValue);

    }

    int socketGetOption(int opt, Object iaContainerObj) throws SocketException {

        int nativefd = checkAndReturnNativeFD();

        // SO_BINDADDR is not a socket option.

        if (opt == SO_BINDADDR) {

            localAddress(nativefd, (InetAddressContainer)iaContainerObj);

            return 0;  // return value doesn't matter.

        }

        // SO_REUSEPORT is not supported on Windows.

        if (opt == SO_REUSEPORT) {

            throw new UnsupportedOperationException("unsupported option");

        }

        // SO_REUSEADDR emulated when using exclusive bind

        if (opt == SO_REUSEADDR && exclusiveBind)

            return isReuseAddress? 1 : -1;

        int value = getIntOption(nativefd, opt);

        switch (opt) {

            case TCP_NODELAY :

            case SO_OOBINLINE :

            case SO_KEEPALIVE :

            case SO_REUSEADDR :

                return (value == 0) ? -1 : 1;

        }

        return value;

    }

    void socketSendUrgentData(int data) throws IOException {

        int nativefd = checkAndReturnNativeFD();

        sendOOB(nativefd, data);

    }

    private int checkAndReturnNativeFD() throws SocketException {

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

            throw new SocketException("Socket closed");

        return fdAccess.get(fd);

    }

    static final int WOULDBLOCK = -2;       // Nothing available (non-blocking)

    static {

        initIDs();

    }

    /* Native methods */

    static native void initIDs();

    static native int socket0(boolean stream, boolean v6Only) throws IOException;

    static native void bind0(int fd, InetAddress localAddress, int localport,

                             boolean exclBind)

        throws IOException;

    static native int connect0(int fd, InetAddress remote, int remotePort)

        throws IOException;

    static native void waitForConnect(int fd, int timeout) throws IOException;

    static native int localPort0(int fd) throws IOException;

    static native void localAddress(int fd, InetAddressContainer in) throws SocketException;

    static native void listen0(int fd, int backlog) throws IOException;

    static native int accept0(int fd, InetSocketAddress[] isaa) throws IOException;

    static native void waitForNewConnection(int fd, int timeout) throws IOException;

    static native int available0(int fd) throws IOException;

    static native void close0(int fd) throws IOException;

    static native void shutdown0(int fd, int howto) throws IOException;

    static native void setIntOption(int fd, int cmd, int optionValue) throws SocketException;

    static native int getIntOption(int fd, int cmd) throws SocketException;

    static native void sendOOB(int fd, int data) throws IOException;

    static native void configureBlocking(int fd, boolean blocking) throws IOException;

}