System.Net.Sockets.SocketPal.GetIPv6MulticastOption C# (CSharp) Метод

        public static unsafe SocketError GetIPv6MulticastOption(SafeCloseSocket handle, SocketOptionName optionName, out 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;

            Interop.Sys.IPv6MulticastOption opt;
            Interop.Error err = Interop.Sys.GetIPv6MulticastOption(handle, optName, &opt);
            if (err != Interop.Error.SUCCESS)
            {
                optionValue = default(IPv6MulticastOption);
                return GetSocketErrorForErrorCode(err);
            }

            optionValue = new IPv6MulticastOption(opt.Address.GetIPAddress(), opt.InterfaceIndex);
            return SocketError.Success;
        }