System.Net.Sockets.SocketPal.SetIPv6MulticastOption C# (CSharp) Метод

        public static unsafe SocketError SetIPv6MulticastOption(SafeCloseSocket handle, SocketOptionName optionName, IPv6MulticastOption optionValue)
        {
            Debug.Assert(optionName == SocketOptionName.AddMembership || optionName == SocketOptionName.DropMembership, $"Unexpected optionName={optionName}");

            Interop.Sys.MulticastOption optName = optionName == SocketOptionName.AddMembership ?
                Interop.Sys.MulticastOption.MULTICAST_ADD :
                Interop.Sys.MulticastOption.MULTICAST_DROP;

            var opt = new Interop.Sys.IPv6MulticastOption {
                Address = optionValue.Group.GetNativeIPAddress(),
                InterfaceIndex = (int)optionValue.InterfaceIndex
            };

            Interop.Error err = Interop.Sys.SetIPv6MulticastOption(handle, optName, &opt);
            return err == Interop.Error.SUCCESS ? SocketError.Success : GetSocketErrorForErrorCode(err);
        }