Re: [PATCH 1/3] libnl: add netfilter support

[Thomas Graf <tgraf@suug.ch>]

* Patrick McHardy <kaber@trash.net> 2007-09-03 12:06
> Thomas Graf wrote:
> > I think I can live with checking for the bit on the receiving side,
> > the only problem it could cause is when the attribute type is used
> > to encode information such as a port number. So if we are willing
> > to take that risk the receiving path could be merged as well.
> 
> 
> That kind of information should be stored as attribute value, no?

Yes it should but we've already got code like this:
for (i = 0; i < cnt; i++)
        nla_put(skb, i, ....);

It's only a matter of time until someone comes up with
something like this:
nla_put(skb, dstport, sizeof(port_info), &port_info);

Maybe we could put a WARN_ON(bit_set) in nla_put() on kernel side
to make sure such behaviour is not being introduced by accident.