System.Net.Sockets.SocketPal.SetSockOpt C# (CSharp) Метод

        public static unsafe SocketError SetSockOpt(SafeCloseSocket handle, SocketOptionLevel optionLevel, SocketOptionName optionName, int optionValue)
        {
            Interop.Error err;

            if (optionLevel == SocketOptionLevel.Socket)
            {
                if (optionName == SocketOptionName.ReceiveTimeout)
                {
                    handle.ReceiveTimeout = optionValue == 0 ? -1 : optionValue;
                    err = Interop.Sys.SetReceiveTimeout(handle, optionValue);
                    return err == Interop.Error.SUCCESS ? SocketError.Success : GetSocketErrorForErrorCode(err);
                }
                else if (optionName == SocketOptionName.SendTimeout)
                {
                    handle.SendTimeout = optionValue == 0 ? -1 : optionValue;
                    err = Interop.Sys.SetSendTimeout(handle, optionValue);
                    return err == Interop.Error.SUCCESS ? SocketError.Success : GetSocketErrorForErrorCode(err);
                }
            }
            else if (optionLevel == SocketOptionLevel.IP)
            {
                if (optionName == SocketOptionName.MulticastInterface)
                {
                    // if the value of the IP_MULTICAST_IF is an address in the 0.x.x.x block
                    // the value is interpreted as an interface index
                    int interfaceIndex = IPAddress.NetworkToHostOrder(optionValue);
                    if ((interfaceIndex & 0xff000000) == 0)
                    {
                        var opt = new Interop.Sys.IPv4MulticastOption {
                            MulticastAddress = 0,
                            LocalAddress = 0,
                            InterfaceIndex = interfaceIndex
                        };

                        err = Interop.Sys.SetIPv4MulticastOption(handle, Interop.Sys.MulticastOption.MULTICAST_IF, &opt);
                        return err == Interop.Error.SUCCESS ? SocketError.Success : GetSocketErrorForErrorCode(err);
                    }
                }
            }

            err = Interop.Sys.SetSockOpt(handle, optionLevel, optionName, (byte*)&optionValue, sizeof(int));
            return err == Interop.Error.SUCCESS ? SocketError.Success : GetSocketErrorForErrorCode(err);
        }