using System;

using System.Collections.Generic;

using System.Net;

using System.Net.Sockets;

using System.Runtime.CompilerServices;

using System.Runtime.InteropServices;

namespace LiteNetLib

{

internal readonly struct NativeAddr : IEquatable<NativeAddr>

{

//common parts

private readonly long _part1; //family, port, etc

private readonly long _part2;

//ipv6 parts

private readonly long _part3;

private readonly int _part4;

private readonly int _hash;

public NativeAddr(byte[] address, int len)

{

_part1 = BitConverter.ToInt64(address, 0);

_part2 = BitConverter.ToInt64(address, 8);

if (len > 16)

{

_part3 = BitConverter.ToInt64(address, 16);

_part4 = BitConverter.ToInt32(address, 24);

}

else

{

_part3 = 0;

_part4 = 0;

}

_hash = (int)(_part1 >> 32) ^ (int)_part1 ^

(int)(_part2 >> 32) ^ (int)_part2 ^

(int)(_part3 >> 32) ^ (int)_part3 ^

_part4;

}

public override int GetHashCode()

{

return _hash;

}

public bool Equals(NativeAddr other)

{

return _part1 == other._part1 &&

_part2 == other._part2 &&

_part3 == other._part3 &&

_part4 == other._part4;

}

public override bool Equals(object obj)

{

return obj is NativeAddr other && Equals(other);

}

public static bool operator ==(NativeAddr left, NativeAddr right)

{

return left.Equals(right);

}

public static bool operator !=(NativeAddr left, NativeAddr right)

{

return !left.Equals(right);

}

}

internal class NativeEndPoint : IPEndPoint

{

public readonly byte[] NativeAddress;

public NativeEndPoint(byte[] address) : base(IPAddress.Any, 0)

{

NativeAddress = new byte[address.Length];

Buffer.BlockCopy(address, 0, NativeAddress, 0, address.Length);

short family = (short)((address[1] << 8) | address[0]);

Port =(ushort)((address[2] << 8) | address[3]);

if ((NativeSocket.UnixMode && family == NativeSocket.AF_INET6) || (!NativeSocket.UnixMode && (AddressFamily)family == AddressFamily.InterNetworkV6))

{

uint scope = unchecked((uint)(

(address[27] << 24) +

(address[26] << 16) +

(address[25] << 8) +

(address[24])));

#if NETCOREAPP || NETSTANDARD2_1 || NETSTANDARD2_1_OR_GREATER

Address = new IPAddress(new ReadOnlySpan<byte>(address, 8, 16), scope);

#else

byte[] addrBuffer = new byte[16];

Buffer.BlockCopy(address, 8, addrBuffer, 0, 16);

Address = new IPAddress(addrBuffer, scope);

#endif

}

else //IPv4

{

long ipv4Addr = unchecked((uint)((address[4] & 0x000000FF) |

(address[5] << 8 & 0x0000FF00) |

(address[6] << 16 & 0x00FF0000) |

(address[7] << 24)));

Address = new IPAddress(ipv4Addr);

}

}

}

internal static class NativeSocket

{

static

#if LITENETLIB_UNSAFE

unsafe

#endif

class WinSock

{

private const string LibName = "ws2_32.dll";

[DllImport(LibName, SetLastError = true)]

public static extern int recvfrom(

IntPtr socketHandle,

[In, Out] byte[] pinnedBuffer,

[In] int len,

[In] SocketFlags socketFlags,

[Out] byte[] socketAddress,

[In, Out] ref int socketAddressSize);

[DllImport(LibName, SetLastError = true)]

internal static extern int sendto(

IntPtr socketHandle,

#if LITENETLIB_UNSAFE

byte* pinnedBuffer,

#else

[In] byte[] pinnedBuffer,

#endif

[In] int len,

[In] SocketFlags socketFlags,

[In] byte[] socketAddress,

[In] int socketAddressSize);

}

static

#if LITENETLIB_UNSAFE

unsafe

#endif

class UnixSock

{

private const string LibName = "libc";

[DllImport(LibName, SetLastError = true)]

public static extern int recvfrom(

IntPtr socketHandle,

[In, Out] byte[] pinnedBuffer,

[In] int len,

[In] SocketFlags socketFlags,

[Out] byte[] socketAddress,

[In, Out] ref int socketAddressSize);

[DllImport(LibName, SetLastError = true)]

internal static extern int sendto(

IntPtr socketHandle,

#if LITENETLIB_UNSAFE

byte* pinnedBuffer,

#else

[In] byte[] pinnedBuffer,

#endif

[In] int len,

[In] SocketFlags socketFlags,

[In] byte[] socketAddress,

[In] int socketAddressSize);

}

public static readonly bool IsSupported = false;

public static readonly bool UnixMode = false;

public const int IPv4AddrSize = 16;

public const int IPv6AddrSize = 28;

public const int AF_INET = 2;

public const int AF_INET6 = 10;

private static readonly Dictionary<int, SocketError> NativeErrorToSocketError = new Dictionary<int, SocketError>

{

{ 13, SocketError.AccessDenied }, //EACCES

{ 98, SocketError.AddressAlreadyInUse }, //EADDRINUSE

{ 99, SocketError.AddressNotAvailable }, //EADDRNOTAVAIL

{ 97, SocketError.AddressFamilyNotSupported }, //EAFNOSUPPORT

{ 11, SocketError.WouldBlock }, //EAGAIN

{ 114, SocketError.AlreadyInProgress }, //EALREADY

{ 9, SocketError.OperationAborted }, //EBADF

{ 125, SocketError.OperationAborted }, //ECANCELED

{ 103, SocketError.ConnectionAborted }, //ECONNABORTED

{ 111, SocketError.ConnectionRefused }, //ECONNREFUSED

{ 104, SocketError.ConnectionReset }, //ECONNRESET

{ 89, SocketError.DestinationAddressRequired }, //EDESTADDRREQ

{ 14, SocketError.Fault }, //EFAULT

{ 112, SocketError.HostDown }, //EHOSTDOWN

{ 6, SocketError.HostNotFound }, //ENXIO

{ 113, SocketError.HostUnreachable }, //EHOSTUNREACH

{ 115, SocketError.InProgress }, //EINPROGRESS

{ 4, SocketError.Interrupted }, //EINTR

{ 22, SocketError.InvalidArgument }, //EINVAL

{ 106, SocketError.IsConnected }, //EISCONN

{ 24, SocketError.TooManyOpenSockets }, //EMFILE

{ 90, SocketError.MessageSize }, //EMSGSIZE

{ 100, SocketError.NetworkDown }, //ENETDOWN

{ 102, SocketError.NetworkReset }, //ENETRESET

{ 101, SocketError.NetworkUnreachable }, //ENETUNREACH

{ 23, SocketError.TooManyOpenSockets }, //ENFILE

{ 105, SocketError.NoBufferSpaceAvailable }, //ENOBUFS

{ 61, SocketError.NoData }, //ENODATA

{ 2, SocketError.AddressNotAvailable }, //ENOENT

{ 92, SocketError.ProtocolOption }, //ENOPROTOOPT

{ 107, SocketError.NotConnected }, //ENOTCONN

{ 88, SocketError.NotSocket }, //ENOTSOCK

{ 3440, SocketError.OperationNotSupported }, //ENOTSUP

{ 1, SocketError.AccessDenied }, //EPERM

{ 32, SocketError.Shutdown }, //EPIPE

{ 96, SocketError.ProtocolFamilyNotSupported }, //EPFNOSUPPORT

{ 93, SocketError.ProtocolNotSupported }, //EPROTONOSUPPORT

{ 91, SocketError.ProtocolType }, //EPROTOTYPE

{ 94, SocketError.SocketNotSupported }, //ESOCKTNOSUPPORT

{ 108, SocketError.Disconnecting }, //ESHUTDOWN

{ 110, SocketError.TimedOut }, //ETIMEDOUT

{ 0, SocketError.Success }

};

static NativeSocket()

{

if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))

{

IsSupported = true;

UnixMode = true;

}

else if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))

{

IsSupported = true;

}

}

[MethodImpl(MethodImplOptions.AggressiveInlining)]

public static int RecvFrom(

IntPtr socketHandle,

byte[] pinnedBuffer,

int len,

byte[] socketAddress,

ref int socketAddressSize)

{

return UnixMode

? UnixSock.recvfrom(socketHandle, pinnedBuffer, len, 0, socketAddress, ref socketAddressSize)

: WinSock.recvfrom(socketHandle, pinnedBuffer, len, 0, socketAddress, ref socketAddressSize);

}

[MethodImpl(MethodImplOptions.AggressiveInlining)]

public

#if LITENETLIB_UNSAFE

unsafe

#endif

static int SendTo(

IntPtr socketHandle,

#if LITENETLIB_UNSAFE

byte* pinnedBuffer,

#else

byte[] pinnedBuffer,

#endif

int len,

byte[] socketAddress,

int socketAddressSize)

{

return UnixMode

? UnixSock.sendto(socketHandle, pinnedBuffer, len, 0, socketAddress, socketAddressSize)

: WinSock.sendto(socketHandle, pinnedBuffer, len, 0, socketAddress, socketAddressSize);

}

public static SocketError GetSocketError()

{

int error = Marshal.GetLastWin32Error();

if (UnixMode)

return NativeErrorToSocketError.TryGetValue(error, out var err)

? err

: SocketError.SocketError;

return (SocketError)error;

}

public static SocketException GetSocketException()

{

int error = Marshal.GetLastWin32Error();

if (UnixMode)

return NativeErrorToSocketError.TryGetValue(error, out var err)

? new SocketException((int)err)

: new SocketException((int)SocketError.SocketError);

return new SocketException(error);

}

[MethodImpl(MethodImplOptions.AggressiveInlining)]

public static short GetNativeAddressFamily(IPEndPoint remoteEndPoint)

{

return UnixMode

? (short)(remoteEndPoint.AddressFamily == AddressFamily.InterNetwork ? AF_INET : AF_INET6)

: (short)remoteEndPoint.AddressFamily;

}

}

}