/// <summary>
/// Returns true if the server is running in a local LAN
/// </summary>
private static bool ServerIsInLocalLan(IPEndPoint serverEndPoint)
{
var ownNetwork = LunaNetUtils.GetOwnInternalIPv6Network();
if (ownNetwork != null && serverEndPoint.AddressFamily == AddressFamily.InterNetworkV6)
{
// For IPv6, we strip both addresses down to the subnet portion (likely the first 64 bits) and compare them.
// Because we only receive Global Unique Addresses from GetOwnInternalIPv6Network() (which are globally
// unique, as the name suggests and the RFCs define), those being equal should mean both are on the same network.
var ownBytes = ownNetwork.Address.GetAddressBytes();
var serverBytes = serverEndPoint.Address.GetAddressBytes();
// TODO IPv6: We currently assume an on-link prefix length of 64 bits, which is the most common case
// and standardized as per the RFCs. UnicastIPAddressInformation.PrefixLength is not implemented yet,
// and also wouldn't be reliable (hosts often assign their address as /128). A possible solution could be
// checking whether serverEndPoint matches any configured on-link/no-gateway route.
Array.Resize(ref ownBytes, 8);
Array.Resize(ref serverBytes, 8);
if (ownBytes == serverBytes)
{
return(true);
}
}
return(Equals(LunaNetUtils.GetOwnExternalIpAddress(), serverEndPoint.Address));
}