public Task <SocketReceiveFromResult> ReceiveFromAsync(ArraySegment <byte> buffer)
{
return(_socket.ReceiveFromAsync(buffer, SocketFlags.None, SocketExtension.GetEndPointAnyFor(_socket.AddressFamily)));
}
public async Task <SocketReceiveFromResult> ReceiveFromAsync(ArraySegment <byte> buffer)
{
byte[] datagram = new byte[262 + buffer.Count];
SocketReceiveFromResult result = await _udpSocket.ReceiveFromAsync(datagram, SocketFlags.None, SocketExtension.GetEndPointAnyFor(_udpSocket.AddressFamily));
if (result.ReceivedBytes < 10)
{
throw new SocksProxyException("Incomplete SOCKS5 datagram was received.");
}
EndPoint remoteEP;
switch ((SocksAddressType)datagram[3])
{
case SocksAddressType.IPv4Address:
{
byte[] address = new byte[4];
Buffer.BlockCopy(datagram, 3 + 1, address, 0, 4);
byte[] port = new byte[2];
Buffer.BlockCopy(datagram, 3 + 1 + 4, port, 0, 2);
Array.Reverse(port);
remoteEP = new IPEndPoint(new IPAddress(address), BitConverter.ToUInt16(port, 0));
}
break;
case SocksAddressType.IPv6Address:
{
byte[] address = new byte[16];
Buffer.BlockCopy(datagram, 3 + 1, address, 0, 16);
byte[] port = new byte[2];
Buffer.BlockCopy(datagram, 3 + 1 + 16, port, 0, 2);
Array.Reverse(port);
remoteEP = new IPEndPoint(new IPAddress(address), BitConverter.ToUInt16(port, 0));
}
break;
case SocksAddressType.DomainName:
{
int length = datagram[3 + 1];
byte[] address = new byte[length];
Buffer.BlockCopy(datagram, 3 + 1 + 1, address, 0, length);
byte[] port = new byte[2];
Buffer.BlockCopy(datagram, 3 + 1 + 1 + length, port, 0, 2);
Array.Reverse(port);
remoteEP = new DomainEndPoint(Encoding.ASCII.GetString(address), BitConverter.ToUInt16(port, 0));
}
break;
default:
throw new NotSupportedException("SocksAddressType not supported.");
}
int addressSize;
switch (remoteEP.AddressFamily)
{
case AddressFamily.InterNetwork:
addressSize = 4;
break;
case AddressFamily.InterNetworkV6:
addressSize = 16;
break;
case AddressFamily.Unspecified:
addressSize = 1 + (remoteEP as DomainEndPoint).Address.Length;
break;
default:
throw new NotSupportedException("AddressFamily not supported.");
}
int dataOffset = 6 + addressSize;
int dataSize = result.ReceivedBytes - dataOffset;
if (dataSize > buffer.Count)
{
dataSize = buffer.Count;
}
ArraySegment <byte> recvData = new ArraySegment <byte>(datagram, dataOffset, dataSize);
recvData.CopyTo(buffer);
if (_relayEP == null)
{
_relayEP = result.RemoteEndPoint; //set new relay ep
}
return(new SocketReceiveFromResult()
{
ReceivedBytes = dataSize, RemoteEndPoint = remoteEP
});
}
