/*
 * 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 java.io.FileDescriptor;
import java.security.AccessController;

import sun.security.action.GetPropertyAction;
import jdk.internal.access.SharedSecrets;
import jdk.internal.access.JavaIOFileDescriptorAccess;

/**
 * On Windows system we simply delegate to native methods.
 *
 * @author Chris Hegarty
 */

class PlainSocketImpl extends AbstractPlainSocketImpl {

 private static final JavaIOFileDescriptorAccess fdAccess =
 SharedSecrets.getJavaIOFileDescriptorAccess();

 private static final boolean preferIPv4Stack =
 Boolean.parseBoolean(AccessController.doPrivileged(
 new GetPropertyAction("java.net.preferIPv4Stack", "false")));

 /**
 * Empty value of sun.net.useExclusiveBind is treated as 'true'.
 */
 private static final boolean useExclusiveBind;

 static {
 String exclBindProp = AccessController.doPrivileged(
 new GetPropertyAction("sun.net.useExclusiveBind", ""));
 useExclusiveBind = exclBindProp.isEmpty()
 || Boolean.parseBoolean(exclBindProp);
 }

 // emulates SO_REUSEADDR when useExclusiveBind is true
 private boolean isReuseAddress;

 /**
 * Constructs an empty instance.
 */
 public PlainSocketImpl() {
 }

 /**
 * Constructs an instance with the given file descriptor.
 */
 public PlainSocketImpl(FileDescriptor fd) {
 this.fd = fd;
 }

 @Override
 void socketCreate(boolean stream) throws IOException {
 if (fd == null)
 throw new SocketException("Socket closed");

 int newfd = socket0(stream);

 fdAccess.set(fd, newfd);
 }

 @Override
 void socketConnect(InetAddress address, int port, int timeout)
 throws IOException {
 int nativefd = checkAndReturnNativeFD();

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

 if (preferIPv4Stack && !(address instanceof Inet4Address))
 throw new SocketException("Protocol family not supported");

 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);
 }

 @Override
 void socketBind(InetAddress address, int port) throws IOException {
 int nativefd = checkAndReturnNativeFD();

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

 if (preferIPv4Stack && !(address instanceof Inet4Address))
 throw new SocketException("Protocol family not supported");

 bind0(nativefd, address, port, useExclusiveBind);
 if (port == 0) {
 localport = localPort0(nativefd);
 } else {
 localport = port;
 }

 this.address = address;
 }

 @Override
 void socketListen(int backlog) throws IOException {
 int nativefd = checkAndReturnNativeFD();

 listen0(nativefd, backlog);
 }

 @Override
 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;
 if (preferIPv4Stack && !(s.address instanceof Inet4Address))
 throw new SocketException("Protocol family not supported");
 }

 @Override
 int socketAvailable() throws IOException {
 int nativefd = checkAndReturnNativeFD();
 return available0(nativefd);
 }

 @Override
 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);
 }

 @Override
 void socketShutdown(int howto) throws IOException {
 int nativefd = checkAndReturnNativeFD();
 shutdown0(nativefd, howto);
 }

 // Intentional fallthrough after SO_REUSEADDR
 @SuppressWarnings("fallthrough")
 @Override
 void socketSetOption(int opt, boolean on, Object value)
 throws SocketException {

 // SO_REUSEPORT is not supported on Windows.
 if (opt == SO_REUSEPORT) {
 throw new UnsupportedOperationException("unsupported option");
 }

 int nativefd = checkAndReturnNativeFD();

 if (opt == SO_TIMEOUT) {
 if (preferIPv4Stack) {
 // Don't enable the socket option on ServerSocket as it's
 // meaningless (we don't receive on a ServerSocket).
 if (serverSocket == null) {
 setSoTimeout0(nativefd, ((Integer)value).intValue());
 }
 } // else timeout is implemented through select.
 return;
 }

 int optionValue = 0;

 switch(opt) {
 case SO_REUSEADDR:
 if (useExclusiveBind) {
 // 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);
 }

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

 // SO_REUSEPORT is not supported on Windows.
 if (opt == SO_REUSEPORT) {
 throw new UnsupportedOperationException("unsupported option");
 }

 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_REUSEADDR emulated when using exclusive bind
 if (opt == SO_REUSEADDR && useExclusiveBind)
 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;
 }

 @Override
 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) 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 void setSoTimeout0(int fd, int timeout) 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;
}