[En-Nut-Discussion] incoming broadcast IP packets filtration

[Harald Kipp]

Александр Усов wrote:

> Sorry for my bad English. If I understood rfc919 right, there are two types
> of broadcasts: "local" which is 255.255.255.255 and "remote" which is, for
> example, 192.168.1.255 when 192.168.1.0 is subnet address. But NutIpInput()

Both are handled in NutIpInput().


> function sets up "bcast" flag even if the destination broadcast IP address
> is from another subnet.

You are right. This may provide problems when setting up subnets.


> Maybe, checking like this:
>    dst == ( nif->if_local_ip | ~nif->if_mask )
> is more correct than
>    ( dst | nif->if_mask ) == INADDR_BROADCAST
> ?

I agree, this would solve it and discard broadcasts to other subnets.

Thanks,

Harald