/*
    * Copyright 2016 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.epoll;
  
  import io.netty.channel.ChannelException;
  import io.netty.channel.DefaultFileRegion;
  import io.netty.channel.unix.Errors;
  import io.netty.channel.unix.NativeInetAddress;
  import io.netty.channel.unix.PeerCredentials;
  import io.netty.channel.unix.Socket;
  import io.netty.channel.socket.InternetProtocolFamily;
  import io.netty.util.internal.PlatformDependent;
  import io.netty.util.internal.SocketUtils;
  import io.netty.util.internal.UnstableApi;
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.Inet6Address;
  import java.net.NetworkInterface;
  import java.net.UnknownHostException;
  import java.util.Enumeration;
  
  import static io.netty.channel.unix.Errors.ioResult;
  import static io.netty.channel.unix.Errors.newIOException;
  
  /**
   * A socket which provides access Linux native methods.
   */
  @UnstableApi
  public final class LinuxSocket extends Socket {
      private static final long MAX_UINT32_T = 0xFFFFFFFFL;
  
      LinuxSocket(int fd) {
          super(fd);
      }
  
      InternetProtocolFamily family() {
          return ipv6 ? InternetProtocolFamily.IPv6 : InternetProtocolFamily.IPv4;
      }
  
      int sendmmsg(NativeDatagramPacketArray.NativeDatagramPacket[] msgs,
                                 int offset, int len) throws IOException {
          return Native.sendmmsg(intValue(), ipv6, msgs, offset, len);
      }
  
      int recvmmsg(NativeDatagramPacketArray.NativeDatagramPacket[] msgs,
                   int offset, int len) throws IOException {
          return Native.recvmmsg(intValue(), ipv6, msgs, offset, len);
      }
  
      int recvmsg(NativeDatagramPacketArray.NativeDatagramPacket msg) throws IOException {
          return Native.recvmsg(intValue(), ipv6, msg);
      }
  
      void setTimeToLive(int ttl) throws IOException {
          setTimeToLive(intValue(), ttl);
      }
  
      void setInterface(InetAddress address) throws IOException {
          final NativeInetAddress a = NativeInetAddress.newInstance(address);
          setInterface(intValue(), ipv6, a.address(), a.scopeId(), interfaceIndex(address));
      }
  
      void setNetworkInterface(NetworkInterface netInterface) throws IOException {
          InetAddress address = deriveInetAddress(netInterface, family() == InternetProtocolFamily.IPv6);
          if (address.equals(family() == InternetProtocolFamily.IPv4 ? Native.INET_ANY : Native.INET6_ANY)) {
              throw new IOException("NetworkInterface does not support " + family());
          }
          final NativeInetAddress nativeAddress = NativeInetAddress.newInstance(address);
          setInterface(intValue(), ipv6, nativeAddress.address(), nativeAddress.scopeId(), interfaceIndex(netInterface));
      }
  
      InetAddress getInterface() throws IOException {
          NetworkInterface inf = getNetworkInterface();
          if (inf != null) {
              Enumeration<InetAddress> addresses = SocketUtils.addressesFromNetworkInterface(inf);
              if (addresses.hasMoreElements()) {
                  return addresses.nextElement();
              }
          }
          return null;
      }
  
      NetworkInterface getNetworkInterface() throws IOException {
          int ret = getInterface(intValue(), ipv6);
          if (ipv6) {
             return PlatformDependent.javaVersion() >= 7 ? NetworkInterface.getByIndex(ret) : null;
         }
         InetAddress address = inetAddress(ret);
         return address != null ? NetworkInterface.getByInetAddress(address) : null;
     }
 
     private static InetAddress inetAddress(int value) {
         byte[] var1 = {
                 (byte) (value >>> 24 & 255),
                 (byte) (value >>> 16 & 255),
                 (byte) (value >>> 8 & 255),
                 (byte) (value & 255)
         };
 
         try {
             return InetAddress.getByAddress(var1);
         } catch (UnknownHostException ignore) {
             return null;
         }
     }
 
     void joinGroup(InetAddress group, NetworkInterface netInterface, InetAddress source) throws IOException {
         final NativeInetAddress g = NativeInetAddress.newInstance(group);
         final boolean isIpv6 = group instanceof Inet6Address;
         final NativeInetAddress i = NativeInetAddress.newInstance(deriveInetAddress(netInterface, isIpv6));
         if (source != null) {
             if (source.getClass() != group.getClass()) {
                 throw new IllegalArgumentException("Source address is different type to group");
             }
             final NativeInetAddress s = NativeInetAddress.newInstance(source);
             joinSsmGroup(intValue(), ipv6 && isIpv6, g.address(), i.address(),
                     g.scopeId(), interfaceIndex(netInterface), s.address());
         } else {
             joinGroup(intValue(), ipv6 && isIpv6, g.address(), i.address(), g.scopeId(), interfaceIndex(netInterface));
         }
     }
 
     void leaveGroup(InetAddress group, NetworkInterface netInterface, InetAddress source) throws IOException {
         final NativeInetAddress g = NativeInetAddress.newInstance(group);
         final boolean isIpv6 = group instanceof Inet6Address;
         final NativeInetAddress i = NativeInetAddress.newInstance(deriveInetAddress(netInterface, isIpv6));
         if (source != null) {
             if (source.getClass() != group.getClass()) {
                 throw new IllegalArgumentException("Source address is different type to group");
             }
             final NativeInetAddress s = NativeInetAddress.newInstance(source);
             leaveSsmGroup(intValue(), ipv6 && isIpv6, g.address(), i.address(),
                     g.scopeId(), interfaceIndex(netInterface), s.address());
         } else {
             leaveGroup(intValue(), ipv6 && isIpv6, g.address(), i.address(), g.scopeId(), interfaceIndex(netInterface));
         }
     }
 
     private static int interfaceIndex(NetworkInterface networkInterface) {
         return PlatformDependent.javaVersion() >= 7 ? networkInterface.getIndex() : -1;
     }
 
     private static int interfaceIndex(InetAddress address) throws IOException {
         if (PlatformDependent.javaVersion() >= 7) {
             NetworkInterface iface = NetworkInterface.getByInetAddress(address);
             if (iface != null) {
                 return iface.getIndex();
             }
         }
         return -1;
     }
 
     void setTcpDeferAccept(int deferAccept) throws IOException {
         setTcpDeferAccept(intValue(), deferAccept);
     }
 
     void setTcpQuickAck(boolean quickAck) throws IOException {
         setTcpQuickAck(intValue(), quickAck ? 1 : 0);
     }
 
     void setTcpCork(boolean tcpCork) throws IOException {
         setTcpCork(intValue(), tcpCork ? 1 : 0);
     }
 
     void setSoBusyPoll(int loopMicros) throws IOException {
         setSoBusyPoll(intValue(), loopMicros);
     }
 
     void setTcpNotSentLowAt(long tcpNotSentLowAt) throws IOException {
         if (tcpNotSentLowAt < 0 || tcpNotSentLowAt > MAX_UINT32_T) {
             throw new IllegalArgumentException("tcpNotSentLowAt must be a uint32_t");
         }
         setTcpNotSentLowAt(intValue(), (int) tcpNotSentLowAt);
     }
 
     void setTcpFastOpen(int tcpFastopenBacklog) throws IOException {
         setTcpFastOpen(intValue(), tcpFastopenBacklog);
     }
 
     void setTcpKeepIdle(int seconds) throws IOException {
         setTcpKeepIdle(intValue(), seconds);
     }
 
     void setTcpKeepIntvl(int seconds) throws IOException {
         setTcpKeepIntvl(intValue(), seconds);
     }
 
     void setTcpKeepCnt(int probes) throws IOException {
         setTcpKeepCnt(intValue(), probes);
     }
 
     void setTcpUserTimeout(int milliseconds) throws IOException {
         setTcpUserTimeout(intValue(), milliseconds);
     }
 
     void setIpBindAddressNoPort(boolean enabled) throws IOException {
         setIpBindAddressNoPort(intValue(), enabled ? 1 : 0);
     }
 
     void setIpFreeBind(boolean enabled) throws IOException {
         setIpFreeBind(intValue(), enabled ? 1 : 0);
     }
 
     void setIpTransparent(boolean enabled) throws IOException {
         setIpTransparent(intValue(), enabled ? 1 : 0);
     }
 
     void setIpRecvOrigDestAddr(boolean enabled) throws IOException {
         setIpRecvOrigDestAddr(intValue(), enabled ? 1 : 0);
     }
 
     int getTimeToLive() throws IOException {
         return getTimeToLive(intValue());
     }
 
     void getTcpInfo(EpollTcpInfo info) throws IOException {
         getTcpInfo(intValue(), info.info);
     }
 
     void setTcpMd5Sig(InetAddress address, byte[] key) throws IOException {
         final NativeInetAddress a = NativeInetAddress.newInstance(address);
         setTcpMd5Sig(intValue(), ipv6, a.address(), a.scopeId(), key);
     }
 
     boolean isTcpCork() throws IOException  {
         return isTcpCork(intValue()) != 0;
     }
 
     int getSoBusyPoll() throws IOException  {
         return getSoBusyPoll(intValue());
     }
 
     int getTcpDeferAccept() throws IOException {
         return getTcpDeferAccept(intValue());
     }
 
     boolean isTcpQuickAck() throws IOException {
         return isTcpQuickAck(intValue()) != 0;
     }
 
     long getTcpNotSentLowAt() throws IOException {
         return getTcpNotSentLowAt(intValue()) & MAX_UINT32_T;
     }
 
     int getTcpKeepIdle() throws IOException {
         return getTcpKeepIdle(intValue());
     }
 
     int getTcpKeepIntvl() throws IOException {
         return getTcpKeepIntvl(intValue());
     }
 
     int getTcpKeepCnt() throws IOException {
         return getTcpKeepCnt(intValue());
     }
 
     int getTcpUserTimeout() throws IOException {
         return getTcpUserTimeout(intValue());
     }
 
     boolean isIpBindAddressNoPort() throws IOException {
         return isIpBindAddressNoPort(intValue()) != 0;
     }
 
     boolean isIpFreeBind() throws IOException {
         return isIpFreeBind(intValue()) != 0;
     }
 
     boolean isIpTransparent() throws IOException {
         return isIpTransparent(intValue()) != 0;
     }
 
     boolean isIpRecvOrigDestAddr() throws IOException {
         return isIpRecvOrigDestAddr(intValue()) != 0;
     }
 
     PeerCredentials getPeerCredentials() throws IOException {
         return getPeerCredentials(intValue());
     }
 
     boolean isLoopbackModeDisabled() throws IOException {
         return getIpMulticastLoop(intValue(), ipv6) == 0;
     }
 
     void setLoopbackModeDisabled(boolean loopbackModeDisabled) throws IOException {
         setIpMulticastLoop(intValue(), ipv6, loopbackModeDisabled ? 0 : 1);
     }
 
     boolean isUdpGro() throws IOException {
         return isUdpGro(intValue()) != 0;
     }
 
     void setUdpGro(boolean gro) throws IOException {
         setUdpGro(intValue(), gro ? 1 : 0);
     }
 
     long sendFile(DefaultFileRegion src, long baseOffset, long offset, long length) throws IOException {
         // Open the file-region as it may be created via the lazy constructor. This is needed as we directly access
         // the FileChannel field via JNI.
         src.open();
 
         long res = sendFile(intValue(), src, baseOffset, offset, length);
         if (res >= 0) {
             return res;
         }
         return ioResult("sendfile", (int) res);
     }
 
     public void bindVSock(VSockAddress address) throws IOException {
         int res = bindVSock(/*fd*/intValue(), address.getCid(), address.getPort());
         if (res < 0) {
             throw newIOException("bindVSock", res);
         }
     }
 
     public boolean connectVSock(VSockAddress address) throws IOException {
         int res = connectVSock(/*fd*/intValue(), address.getCid(), address.getPort());
         if (res < 0) {
             return Errors.handleConnectErrno("connectVSock", res);
         }
         return true;
     }
 
     public VSockAddress remoteVSockAddress() {
         byte[] addr = remoteVSockAddress(/*fd*/intValue());
         if (addr == null) {
             return null;
         }
         int cid = getIntAt(addr, 0);
         int port = getIntAt(addr, 4);
         return new VSockAddress(cid, port);
     }
 
     public VSockAddress localVSockAddress() {
         byte[] addr = localVSockAddress(/*fd*/intValue());
         if (addr == null) {
             return null;
         }
         int cid = getIntAt(addr, 0);
         int port = getIntAt(addr, 4);
         return new VSockAddress(cid, port);
     }
 
     private static int getIntAt(byte[] array, int startIndex) {
         return array[startIndex] << 24 | (array[startIndex + 1] & 0xFF) << 16
                 | (array[startIndex + 2] & 0xFF) << 8 | (array[startIndex + 3] & 0xFF);
     }
 
     private static InetAddress deriveInetAddress(NetworkInterface netInterface, boolean ipv6) {
         final InetAddress ipAny = ipv6 ? Native.INET6_ANY : Native.INET_ANY;
         if (netInterface != null) {
             final Enumeration<InetAddress> ias = netInterface.getInetAddresses();
             while (ias.hasMoreElements()) {
                 final InetAddress ia = ias.nextElement();
                 final boolean isV6 = ia instanceof Inet6Address;
                 if (isV6 == ipv6) {
                     return ia;
                 }
             }
         }
         return ipAny;
     }
 
     public static LinuxSocket newSocket(int fd) {
         return new LinuxSocket(fd);
     }
 
     public static LinuxSocket newVSockStream() {
         return new LinuxSocket(newVSockStream0());
     }
 
     static int newVSockStream0() {
         int res = newVSockStreamFd();
         if (res < 0) {
             throw new ChannelException(newIOException("newVSockStream", res));
         }
         return res;
     }
 
     public static LinuxSocket newSocketStream(boolean ipv6) {
         return new LinuxSocket(newSocketStream0(ipv6));
     }
 
     public static LinuxSocket newSocketStream(InternetProtocolFamily protocol) {
         return new LinuxSocket(newSocketStream0(protocol));
     }
 
     public static LinuxSocket newSocketStream() {
         return newSocketStream(isIPv6Preferred());
     }
 
     public static LinuxSocket newSocketDgram(boolean ipv6) {
         return new LinuxSocket(newSocketDgram0(ipv6));
     }
 
     public static LinuxSocket newSocketDgram(InternetProtocolFamily family) {
         return new LinuxSocket(newSocketDgram0(family));
     }
 
     public static LinuxSocket newSocketDgram() {
         return newSocketDgram(isIPv6Preferred());
     }
 
     public static LinuxSocket newSocketDomain() {
         return new LinuxSocket(newSocketDomain0());
     }
 
     public static LinuxSocket newSocketDomainDgram() {
         return new LinuxSocket(newSocketDomainDgram0());
     }
 
     private static native int newVSockStreamFd();
     private static native int bindVSock(int fd, int cid, int port);
     private static native int connectVSock(int fd, int cid, int port);
     private static native byte[] remoteVSockAddress(int fd);
     private static native byte[] localVSockAddress(int fd);
 
     private static native void joinGroup(int fd, boolean ipv6, byte[] group, byte[] interfaceAddress,
                                          int scopeId, int interfaceIndex) throws IOException;
     private static native void joinSsmGroup(int fd, boolean ipv6, byte[] group, byte[] interfaceAddress,
                                             int scopeId, int interfaceIndex, byte[] source) throws IOException;
     private static native void leaveGroup(int fd, boolean ipv6, byte[] group, byte[] interfaceAddress,
                                           int scopeId, int interfaceIndex) throws IOException;
     private static native void leaveSsmGroup(int fd, boolean ipv6, byte[] group, byte[] interfaceAddress,
                                              int scopeId, int interfaceIndex, byte[] source) throws IOException;
     private static native long sendFile(int socketFd, DefaultFileRegion src, long baseOffset,
                                         long offset, long length) throws IOException;
 
     private static native int getTcpDeferAccept(int fd) throws IOException;
     private static native int isTcpQuickAck(int fd) throws IOException;
     private static native int isTcpCork(int fd) throws IOException;
     private static native int getSoBusyPoll(int fd) throws IOException;
     private static native int getTcpNotSentLowAt(int fd) throws IOException;
     private static native int getTcpKeepIdle(int fd) throws IOException;
     private static native int getTcpKeepIntvl(int fd) throws IOException;
     private static native int getTcpKeepCnt(int fd) throws IOException;
     private static native int getTcpUserTimeout(int fd) throws IOException;
     private static native int getTimeToLive(int fd) throws IOException;
     private static native int isIpBindAddressNoPort(int fd) throws IOException;
     private static native int isIpFreeBind(int fd) throws IOException;
     private static native int isIpTransparent(int fd) throws IOException;
     private static native int isIpRecvOrigDestAddr(int fd) throws IOException;
     private static native void getTcpInfo(int fd, long[] array) throws IOException;
     private static native PeerCredentials getPeerCredentials(int fd) throws IOException;
 
     private static native void setTcpDeferAccept(int fd, int deferAccept) throws IOException;
     private static native void setTcpQuickAck(int fd, int quickAck) throws IOException;
     private static native void setTcpCork(int fd, int tcpCork) throws IOException;
     private static native void setSoBusyPoll(int fd, int loopMicros) throws IOException;
     private static native void setTcpNotSentLowAt(int fd, int tcpNotSentLowAt) throws IOException;
     private static native void setTcpFastOpen(int fd, int tcpFastopenBacklog) throws IOException;
     private static native void setTcpKeepIdle(int fd, int seconds) throws IOException;
     private static native void setTcpKeepIntvl(int fd, int seconds) throws IOException;
     private static native void setTcpKeepCnt(int fd, int probes) throws IOException;
     private static native void setTcpUserTimeout(int fd, int milliseconds)throws IOException;
     private static native void setIpBindAddressNoPort(int fd, int ipBindAddressNoPort) throws IOException;
     private static native void setIpFreeBind(int fd, int freeBind) throws IOException;
     private static native void setIpTransparent(int fd, int transparent) throws IOException;
     private static native void setIpRecvOrigDestAddr(int fd, int transparent) throws IOException;
     private static native void setTcpMd5Sig(
             int fd, boolean ipv6, byte[] address, int scopeId, byte[] key) throws IOException;
     private static native void setInterface(
             int fd, boolean ipv6, byte[] interfaceAddress, int scopeId, int networkInterfaceIndex) throws IOException;
     private static native int getInterface(int fd, boolean ipv6);
     private static native int getIpMulticastLoop(int fd, boolean ipv6) throws IOException;
     private static native void setIpMulticastLoop(int fd, boolean ipv6, int enabled) throws IOException;
     private static native void setTimeToLive(int fd, int ttl) throws IOException;
     private static native int isUdpGro(int fd) throws IOException;
     private static native void setUdpGro(int fd, int gro) throws IOException;
 }