/*
    * Copyright 2015 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.channel.unix;
  
  import io.netty.channel.ChannelException;
  import io.netty.channel.socket.InternetProtocolFamily;
  import io.netty.util.CharsetUtil;
  import io.netty.util.NetUtil;
  
  import java.io.IOException;
  import java.net.Inet6Address;
  import java.net.InetAddress;
  import java.net.InetSocketAddress;
  import java.net.PortUnreachableException;
  import java.net.SocketAddress;
  import java.nio.ByteBuffer;
  import java.nio.channels.ClosedChannelException;
  
  import static io.netty.channel.unix.Errors.ERRNO_EAGAIN_NEGATIVE;
  import static io.netty.channel.unix.Errors.ERRNO_EINPROGRESS_NEGATIVE;
  import static io.netty.channel.unix.Errors.ERRNO_EWOULDBLOCK_NEGATIVE;
  import static io.netty.channel.unix.Errors.ERROR_ECONNREFUSED_NEGATIVE;
  import static io.netty.channel.unix.Errors.handleConnectErrno;
  import static io.netty.channel.unix.Errors.ioResult;
  import static io.netty.channel.unix.Errors.newIOException;
  import static io.netty.channel.unix.NativeInetAddress.address;
  import static io.netty.channel.unix.NativeInetAddress.ipv4MappedIpv6Address;
  
  /**
   * Provides a JNI bridge to native socket operations.
   * <strong>Internal usage only!</strong>
   */
  public class Socket extends FileDescriptor {
  
      private static volatile boolean isIpv6Preferred;
  
      @Deprecated
      public static final int UDS_SUN_PATH_SIZE = 100;
  
      protected final boolean ipv6;
  
      public Socket(int fd) {
          super(fd);
          ipv6 = isIPv6(fd);
      }
      /**
       * Returns {@code true} if we should use IPv6 internally, {@code false} otherwise.
       */
      private boolean useIpv6(InetAddress address) {
          return useIpv6(this, address);
      }
  
      /**
       * Returns {@code true} if the given socket and address combination should use IPv6 internally,
       * {@code false} otherwise.
       */
      protected static boolean useIpv6(Socket socket, InetAddress address) {
          return socket.ipv6 || address instanceof Inet6Address;
      }
  
      public final void shutdown() throws IOException {
          shutdown(true, true);
      }
  
      public final void shutdown(boolean read, boolean write) throws IOException {
          for (;;) {
              // We need to only shutdown what has not been shutdown yet, and if there is no change we should not
              // shutdown anything. This is because if the underlying FD is reused and we still have an object which
              // represents the previous incarnation of the FD we need to be sure we don't inadvertently shutdown the
              // "new" FD without explicitly having a change.
              final int oldState = state;
              if (isClosed(oldState)) {
                  throw new ClosedChannelException();
              }
              int newState = oldState;
              if (read && !isInputShutdown(newState)) {
                  newState = inputShutdown(newState);
              }
              if (write && !isOutputShutdown(newState)) {
                  newState = outputShutdown(newState);
              }
  
              // If there is no change in state, then we should not take any action.
              if (newState == oldState) {
                  return;
              }
             if (casState(oldState, newState)) {
                 break;
             }
         }
         int res = shutdown(fd, read, write);
         if (res < 0) {
             ioResult("shutdown", res);
         }
     }
 
     public final boolean isShutdown() {
         int state = this.state;
         return isInputShutdown(state) && isOutputShutdown(state);
     }
 
     public final boolean isInputShutdown() {
         return isInputShutdown(state);
     }
 
     public final boolean isOutputShutdown() {
         return isOutputShutdown(state);
     }
 
     public final int sendTo(ByteBuffer buf, int pos, int limit, InetAddress addr, int port) throws IOException {
         return sendTo(buf, pos, limit, addr, port, false);
     }
 
     public final int sendTo(ByteBuffer buf, int pos, int limit, InetAddress addr, int port, boolean fastOpen)
             throws IOException {
         // just duplicate the toNativeInetAddress code here to minimize object creation as this method is expected
         // to be called frequently
         byte[] address;
         int scopeId;
         if (addr instanceof Inet6Address) {
             address = addr.getAddress();
             scopeId = ((Inet6Address) addr).getScopeId();
         } else {
             // convert to ipv4 mapped ipv6 address;
             scopeId = 0;
             address = ipv4MappedIpv6Address(addr.getAddress());
         }
         int flags = fastOpen ? msgFastopen() : 0;
         int res = sendTo(fd, useIpv6(addr), buf, pos, limit, address, scopeId, port, flags);
         if (res >= 0) {
             return res;
         }
         if (res == ERRNO_EINPROGRESS_NEGATIVE && fastOpen) {
             // This happens when we (as a client) have no pre-existing cookie for doing a fast-open connection.
             // In this case, our TCP connection will be established normally, but no data was transmitted at this time.
             // We'll just transmit the data with normal writes later.
             return 0;
         }
         if (res == ERROR_ECONNREFUSED_NEGATIVE) {
             throw new PortUnreachableException("sendTo failed");
         }
         return ioResult("sendTo", res);
     }
 
     public final int sendToDomainSocket(ByteBuffer buf, int pos, int limit, byte[] path) throws IOException {
         int res = sendToDomainSocket(fd, buf, pos, limit, path);
         if (res >= 0) {
             return res;
         }
         return ioResult("sendToDomainSocket", res);
     }
 
     public final int sendToAddress(long memoryAddress, int pos, int limit, InetAddress addr, int port)
             throws IOException {
         return sendToAddress(memoryAddress, pos, limit, addr, port, false);
     }
 
     public final int sendToAddress(long memoryAddress, int pos, int limit, InetAddress addr, int port,
                                    boolean fastOpen) throws IOException {
         // just duplicate the toNativeInetAddress code here to minimize object creation as this method is expected
         // to be called frequently
         byte[] address;
         int scopeId;
         if (addr instanceof Inet6Address) {
             address = addr.getAddress();
             scopeId = ((Inet6Address) addr).getScopeId();
         } else {
             // convert to ipv4 mapped ipv6 address;
             scopeId = 0;
             address = ipv4MappedIpv6Address(addr.getAddress());
         }
         int flags = fastOpen ? msgFastopen() : 0;
         int res = sendToAddress(fd, useIpv6(addr), memoryAddress, pos, limit, address, scopeId, port, flags);
         if (res >= 0) {
             return res;
         }
         if (res == ERRNO_EINPROGRESS_NEGATIVE && fastOpen) {
             // This happens when we (as a client) have no pre-existing cookie for doing a fast-open connection.
             // In this case, our TCP connection will be established normally, but no data was transmitted at this time.
             // We'll just transmit the data with normal writes later.
             return 0;
         }
         if (res == ERROR_ECONNREFUSED_NEGATIVE) {
             throw new PortUnreachableException("sendToAddress failed");
         }
         return ioResult("sendToAddress", res);
     }
 
     public final int sendToAddressDomainSocket(long memoryAddress, int pos, int limit, byte[] path) throws IOException {
         int res = sendToAddressDomainSocket(fd, memoryAddress, pos, limit, path);
         if (res >= 0) {
             return res;
         }
         return ioResult("sendToAddressDomainSocket", res);
     }
 
     public final int sendToAddresses(long memoryAddress, int length, InetAddress addr, int port) throws IOException {
         return sendToAddresses(memoryAddress, length, addr, port, false);
     }
 
     public final int sendToAddresses(long memoryAddress, int length, InetAddress addr, int port, boolean fastOpen)
             throws IOException {
         // just duplicate the toNativeInetAddress code here to minimize object creation as this method is expected
         // to be called frequently
         byte[] address;
         int scopeId;
         if (addr instanceof Inet6Address) {
             address = addr.getAddress();
             scopeId = ((Inet6Address) addr).getScopeId();
         } else {
             // convert to ipv4 mapped ipv6 address;
             scopeId = 0;
             address = ipv4MappedIpv6Address(addr.getAddress());
         }
         int flags = fastOpen ? msgFastopen() : 0;
         int res = sendToAddresses(fd, useIpv6(addr), memoryAddress, length, address, scopeId, port, flags);
         if (res >= 0) {
             return res;
         }
         if (res == ERRNO_EINPROGRESS_NEGATIVE && fastOpen) {
             // This happens when we (as a client) have no pre-existing cookie for doing a fast-open connection.
             // In this case, our TCP connection will be established normally, but no data was transmitted at this time.
             // We'll just transmit the data with normal writes later.
             return 0;
         }
         if (res == ERROR_ECONNREFUSED_NEGATIVE) {
             throw new PortUnreachableException("sendToAddresses failed");
         }
         return ioResult("sendToAddresses", res);
     }
 
     public final int sendToAddressesDomainSocket(long memoryAddress, int length, byte[] path) throws IOException {
         int res = sendToAddressesDomainSocket(fd, memoryAddress, length, path);
         if (res >= 0) {
             return res;
         }
         return ioResult("sendToAddressesDomainSocket", res);
     }
 
     public final DatagramSocketAddress recvFrom(ByteBuffer buf, int pos, int limit) throws IOException {
         return recvFrom(fd, buf, pos, limit);
     }
 
     public final DatagramSocketAddress recvFromAddress(long memoryAddress, int pos, int limit) throws IOException {
         return recvFromAddress(fd, memoryAddress, pos, limit);
     }
 
     public final DomainDatagramSocketAddress recvFromDomainSocket(ByteBuffer buf, int pos, int limit)
             throws IOException {
         return recvFromDomainSocket(fd, buf, pos, limit);
     }
 
     public final DomainDatagramSocketAddress recvFromAddressDomainSocket(long memoryAddress, int pos, int limit)
             throws IOException {
         return recvFromAddressDomainSocket(fd, memoryAddress, pos, limit);
     }
 
     public int recv(ByteBuffer buf, int pos, int limit) throws IOException {
         int res = recv(intValue(), buf, pos, limit);
         if (res > 0) {
             return res;
         }
         if (res == 0) {
             return -1;
         }
         return ioResult("recv", res);
     }
 
     public int recvAddress(long address, int pos, int limit) throws IOException {
         int res = recvAddress(intValue(), address, pos, limit);
         if (res > 0) {
             return res;
         }
         if (res == 0) {
             return -1;
         }
         return ioResult("recvAddress", res);
     }
 
     public int send(ByteBuffer buf, int pos, int limit) throws IOException {
         int res = send(intValue(), buf, pos, limit);
         if (res >= 0) {
             return res;
         }
         return ioResult("send", res);
     }
 
     public int sendAddress(long address, int pos, int limit) throws IOException {
         int res = sendAddress(intValue(), address, pos, limit);
         if (res >= 0) {
             return res;
         }
         return ioResult("sendAddress", res);
     }
 
     public final int recvFd() throws IOException {
         int res = recvFd(fd);
         if (res > 0) {
             return res;
         }
         if (res == 0) {
             return -1;
         }
 
         if (res == ERRNO_EAGAIN_NEGATIVE || res == ERRNO_EWOULDBLOCK_NEGATIVE) {
             // Everything consumed so just return -1 here.
             return 0;
         }
         throw newIOException("recvFd", res);
     }
 
     public final int sendFd(int fdToSend) throws IOException {
         int res = sendFd(fd, fdToSend);
         if (res >= 0) {
             return res;
         }
         if (res == ERRNO_EAGAIN_NEGATIVE || res == ERRNO_EWOULDBLOCK_NEGATIVE) {
             // Everything consumed so just return -1 here.
             return -1;
         }
         throw newIOException("sendFd", res);
     }
 
     public final boolean connect(SocketAddress socketAddress) throws IOException {
         int res;
         if (socketAddress instanceof InetSocketAddress) {
             InetSocketAddress inetSocketAddress = (InetSocketAddress) socketAddress;
             InetAddress inetAddress = inetSocketAddress.getAddress();
             NativeInetAddress address = NativeInetAddress.newInstance(inetAddress);
             res = connect(fd, useIpv6(inetAddress), address.address, address.scopeId, inetSocketAddress.getPort());
         } else if (socketAddress instanceof DomainSocketAddress) {
             DomainSocketAddress unixDomainSocketAddress = (DomainSocketAddress) socketAddress;
             res = connectDomainSocket(fd, unixDomainSocketAddress.path().getBytes(CharsetUtil.UTF_8));
         } else {
             throw new Error("Unexpected SocketAddress implementation " + socketAddress);
         }
         if (res < 0) {
             return handleConnectErrno("connect", res);
         }
         return true;
     }
 
     public final boolean finishConnect() throws IOException {
         int res = finishConnect(fd);
         if (res < 0) {
             return handleConnectErrno("finishConnect", res);
         }
         return true;
     }
 
     public final void disconnect() throws IOException {
         int res = disconnect(fd, ipv6);
         if (res < 0) {
             handleConnectErrno("disconnect", res);
         }
     }
 
     public final void bind(SocketAddress socketAddress) throws IOException {
         if (socketAddress instanceof InetSocketAddress) {
             InetSocketAddress addr = (InetSocketAddress) socketAddress;
             InetAddress inetAddress = addr.getAddress();
             NativeInetAddress address = NativeInetAddress.newInstance(inetAddress);
             int res = bind(fd, useIpv6(inetAddress), address.address, address.scopeId, addr.getPort());
             if (res < 0) {
                 throw newIOException("bind", res);
             }
         } else if (socketAddress instanceof DomainSocketAddress) {
             DomainSocketAddress addr = (DomainSocketAddress) socketAddress;
             int res = bindDomainSocket(fd, addr.path().getBytes(CharsetUtil.UTF_8));
             if (res < 0) {
                 throw newIOException("bind", res);
             }
         } else {
             throw new Error("Unexpected SocketAddress implementation " + socketAddress);
         }
     }
 
     public final void listen(int backlog) throws IOException {
         int res = listen(fd, backlog);
         if (res < 0) {
             throw newIOException("listen", res);
         }
     }
 
     public final int accept(byte[] addr) throws IOException {
         int res = accept(fd, addr);
         if (res >= 0) {
             return res;
         }
         if (res == ERRNO_EAGAIN_NEGATIVE || res == ERRNO_EWOULDBLOCK_NEGATIVE) {
             // Everything consumed so just return -1 here.
             return -1;
         }
         throw newIOException("accept", res);
     }
 
     public final InetSocketAddress remoteAddress() {
         byte[] addr = remoteAddress(fd);
         // addr may be null if getpeername failed.
         // See https://github.com/netty/netty/issues/3328
         return addr == null ? null : address(addr, 0, addr.length);
     }
 
     public final DomainSocketAddress remoteDomainSocketAddress() {
         byte[] addr = remoteDomainSocketAddress(fd);
         return addr == null ? null : new DomainSocketAddress(new String(addr));
     }
 
     public final InetSocketAddress localAddress() {
         byte[] addr = localAddress(fd);
         // addr may be null if getpeername failed.
         // See https://github.com/netty/netty/issues/3328
         return addr == null ? null : address(addr, 0, addr.length);
     }
 
     public final DomainSocketAddress localDomainSocketAddress() {
         byte[] addr = localDomainSocketAddress(fd);
         return addr == null ? null : new DomainSocketAddress(new String(addr));
     }
 
     public final int getReceiveBufferSize() throws IOException {
         return getReceiveBufferSize(fd);
     }
 
     public final int getSendBufferSize() throws IOException {
         return getSendBufferSize(fd);
     }
 
     public final boolean isKeepAlive() throws IOException {
         return isKeepAlive(fd) != 0;
     }
 
     public final boolean isTcpNoDelay() throws IOException {
         return isTcpNoDelay(fd) != 0;
     }
 
     public final boolean isReuseAddress() throws IOException {
         return isReuseAddress(fd) != 0;
     }
 
     public final boolean isReusePort() throws IOException {
         return isReusePort(fd) != 0;
     }
 
     public final boolean isBroadcast() throws IOException {
         return isBroadcast(fd) != 0;
     }
 
     public final int getSoLinger() throws IOException {
         return getSoLinger(fd);
     }
 
     public final int getSoError() throws IOException {
         return getSoError(fd);
     }
 
     public final int getTrafficClass() throws IOException {
         return getTrafficClass(fd, ipv6);
     }
 
     public final void setKeepAlive(boolean keepAlive) throws IOException {
         setKeepAlive(fd, keepAlive ? 1 : 0);
     }
 
     public final void setReceiveBufferSize(int receiveBufferSize) throws IOException  {
         setReceiveBufferSize(fd, receiveBufferSize);
     }
 
     public final void setSendBufferSize(int sendBufferSize) throws IOException {
         setSendBufferSize(fd, sendBufferSize);
     }
 
     public final void setTcpNoDelay(boolean tcpNoDelay) throws IOException  {
         setTcpNoDelay(fd, tcpNoDelay ? 1 : 0);
     }
 
     public final void setSoLinger(int soLinger) throws IOException {
         setSoLinger(fd, soLinger);
     }
 
     public final void setReuseAddress(boolean reuseAddress) throws IOException {
         setReuseAddress(fd, reuseAddress ? 1 : 0);
     }
 
     public final void setReusePort(boolean reusePort) throws IOException {
         setReusePort(fd, reusePort ? 1 : 0);
     }
 
     public final void setBroadcast(boolean broadcast) throws IOException {
         setBroadcast(fd, broadcast ? 1 : 0);
     }
 
     public final void setTrafficClass(int trafficClass) throws IOException {
         setTrafficClass(fd, ipv6, trafficClass);
     }
 
     public void setIntOpt(int level, int optname, int optvalue) throws IOException {
         setIntOpt(fd, level, optname, optvalue);
     }
 
     public void setRawOpt(int level, int optname, ByteBuffer optvalue) throws IOException {
         int limit = optvalue.limit();
         if (optvalue.isDirect()) {
             setRawOptAddress(fd, level, optname,
                     Buffer.memoryAddress(optvalue) + optvalue.position(), optvalue.remaining());
         } else if (optvalue.hasArray()) {
             setRawOptArray(fd, level, optname,
                     optvalue.array(), optvalue.arrayOffset() + optvalue.position(), optvalue.remaining());
         } else {
             byte[] bytes = new byte[optvalue.remaining()];
             optvalue.duplicate().get(bytes);
             setRawOptArray(fd, level, optname, bytes, 0, bytes.length);
         }
         optvalue.position(limit);
     }
 
     public int getIntOpt(int level, int optname) throws IOException {
         return getIntOpt(fd, level, optname);
     }
 
     public void getRawOpt(int level, int optname, ByteBuffer out) throws IOException {
         if (out.isDirect()) {
             getRawOptAddress(fd, level, optname, Buffer.memoryAddress(out) + out.position() , out.remaining());
         } else if (out.hasArray()) {
             getRawOptArray(fd, level, optname, out.array(), out.position() + out.arrayOffset(), out.remaining());
         } else {
             byte[] outArray = new byte[out.remaining()];
             getRawOptArray(fd, level, optname, outArray, 0, outArray.length);
             out.put(outArray);
         }
         out.position(out.limit());
     }
 
     public static boolean isIPv6Preferred() {
         return isIpv6Preferred;
     }
 
     public static boolean shouldUseIpv6(InternetProtocolFamily family) {
         return family == null ? isIPv6Preferred() :
                         family == InternetProtocolFamily.IPv6;
     }
 
     private static native boolean isIPv6Preferred0(boolean ipv4Preferred);
 
     private static native boolean isIPv6(int fd);
 
     @Override
     public String toString() {
         return "Socket{" +
                 "fd=" + fd +
                 '}';
     }
 
     public static Socket newSocketStream() {
         return new Socket(newSocketStream0());
     }
 
     public static Socket newSocketDgram() {
         return new Socket(newSocketDgram0());
     }
 
     public static Socket newSocketDomain() {
         return new Socket(newSocketDomain0());
     }
 
     public static Socket newSocketDomainDgram() {
         return new Socket(newSocketDomainDgram0());
     }
 
     public static void initialize() {
         isIpv6Preferred = isIPv6Preferred0(NetUtil.isIpV4StackPreferred());
     }
 
     protected static int newSocketStream0() {
         return newSocketStream0(isIPv6Preferred());
     }
 
     protected static int newSocketStream0(InternetProtocolFamily protocol) {
         return newSocketStream0(shouldUseIpv6(protocol));
     }
 
     protected static int newSocketStream0(boolean ipv6) {
         int res = newSocketStreamFd(ipv6);
         if (res < 0) {
             throw new ChannelException(newIOException("newSocketStream", res));
         }
         return res;
     }
 
     protected static int newSocketDgram0() {
         return newSocketDgram0(isIPv6Preferred());
     }
 
     protected static int newSocketDgram0(InternetProtocolFamily family) {
         return newSocketDgram0(shouldUseIpv6(family));
     }
 
     protected static int newSocketDgram0(boolean ipv6) {
         int res = newSocketDgramFd(ipv6);
         if (res < 0) {
             throw new ChannelException(newIOException("newSocketDgram", res));
         }
         return res;
     }
 
     protected static int newSocketDomain0() {
         int res = newSocketDomainFd();
         if (res < 0) {
             throw new ChannelException(newIOException("newSocketDomain", res));
         }
         return res;
     }
 
     protected static int newSocketDomainDgram0() {
         int res = newSocketDomainDgramFd();
         if (res < 0) {
             throw new ChannelException(newIOException("newSocketDomainDgram", res));
         }
         return res;
     }
 
     private static native int shutdown(int fd, boolean read, boolean write);
     private static native int connect(int fd, boolean ipv6, byte[] address, int scopeId, int port);
     private static native int connectDomainSocket(int fd, byte[] path);
     private static native int finishConnect(int fd);
     private static native int disconnect(int fd, boolean ipv6);
     private static native int bind(int fd, boolean ipv6, byte[] address, int scopeId, int port);
     private static native int bindDomainSocket(int fd, byte[] path);
     private static native int listen(int fd, int backlog);
     private static native int accept(int fd, byte[] addr);
 
     private static native byte[] remoteAddress(int fd);
     private static native byte[] remoteDomainSocketAddress(int fd);
     private static native byte[] localAddress(int fd);
     private static native byte[] localDomainSocketAddress(int fd);
 
     private static native int send(int fd, ByteBuffer buf, int pos, int limit);
     private static native int sendAddress(int fd, long address, int pos, int limit);
     private static native int recv(int fd, ByteBuffer buf, int pos, int limit);
 
     private static native int recvAddress(int fd, long address, int pos, int limit);
 
     private static native int sendTo(
             int fd, boolean ipv6, ByteBuffer buf, int pos, int limit, byte[] address, int scopeId, int port,
             int flags);
 
     private static native int sendToAddress(
             int fd, boolean ipv6, long memoryAddress, int pos, int limit, byte[] address, int scopeId, int port,
             int flags);
 
     private static native int sendToAddresses(
             int fd, boolean ipv6, long memoryAddress, int length, byte[] address, int scopeId, int port,
             int flags);
 
     private static native int sendToDomainSocket(int fd, ByteBuffer buf, int pos, int limit, byte[] path);
     private static native int sendToAddressDomainSocket(int fd, long memoryAddress, int pos, int limit, byte[] path);
     private static native int sendToAddressesDomainSocket(int fd, long memoryAddress, int length, byte[] path);
 
     private static native DatagramSocketAddress recvFrom(
             int fd, ByteBuffer buf, int pos, int limit) throws IOException;
     private static native DatagramSocketAddress recvFromAddress(
             int fd, long memoryAddress, int pos, int limit) throws IOException;
     private static native DomainDatagramSocketAddress recvFromDomainSocket(
             int fd, ByteBuffer buf, int pos, int limit) throws IOException;
     private static native DomainDatagramSocketAddress recvFromAddressDomainSocket(
             int fd, long memoryAddress, int pos, int limit) throws IOException;
     private static native int recvFd(int fd);
     private static native int sendFd(int socketFd, int fd);
     private static native int msgFastopen();
 
     private static native int newSocketStreamFd(boolean ipv6);
     private static native int newSocketDgramFd(boolean ipv6);
     private static native int newSocketDomainFd();
     private static native int newSocketDomainDgramFd();
 
     private static native int isReuseAddress(int fd) throws IOException;
     private static native int isReusePort(int fd) throws IOException;
     private static native int getReceiveBufferSize(int fd) throws IOException;
     private static native int getSendBufferSize(int fd) throws IOException;
     private static native int isKeepAlive(int fd) throws IOException;
     private static native int isTcpNoDelay(int fd) throws IOException;
     private static native int isBroadcast(int fd) throws IOException;
     private static native int getSoLinger(int fd) throws IOException;
     private static native int getSoError(int fd) throws IOException;
     private static native int getTrafficClass(int fd, boolean ipv6) throws IOException;
 
     private static native void setReuseAddress(int fd, int reuseAddress) throws IOException;
     private static native void setReusePort(int fd, int reuseAddress) throws IOException;
     private static native void setKeepAlive(int fd, int keepAlive) throws IOException;
     private static native void setReceiveBufferSize(int fd, int receiveBufferSize) throws IOException;
     private static native void setSendBufferSize(int fd, int sendBufferSize) throws IOException;
     private static native void setTcpNoDelay(int fd, int tcpNoDelay) throws IOException;
     private static native void setSoLinger(int fd, int soLinger) throws IOException;
     private static native void setBroadcast(int fd, int broadcast) throws IOException;
     private static native void setTrafficClass(int fd, boolean ipv6, int trafficClass) throws IOException;
 
     private static native void setIntOpt(int fd, int level, int optname, int optvalue) throws IOException;
     private static native void setRawOptArray(int fd, int level, int optname, byte[] optvalue, int offset, int length)
             throws IOException;
     private static native void setRawOptAddress(int fd, int level, int optname, long optvalueMemoryAddress, int length)
             throws IOException;
     private static native int getIntOpt(int fd, int level, int optname) throws IOException;
     private static native void getRawOptArray(int fd, int level, int optname, byte[] out, int offset, int length)
             throws IOException;
     private static native void getRawOptAddress(int fd, int level, int optname, long outMemoryAddress, int length)
             throws IOException;
 }