Re: [PATCH net 1/1 v2] rtnetlink: require unique netns identifier

On Tue, 06 Feb 2018 16:31:29 -0600, Eric W. Biederman wrote:

Frankly.  If we are talking precedence it should be:
fds
netnsids
pids

The current order is 1. pids, 2. fds, though. Not that it matters much,
see below.

I do think it makes a lot of sense to error if someone passes in
duplicate arguments.  AKA multiple attribute that could select for
the same thing.   No one will do that deliberately.  It doesn't make
sense.  So it is just a nonsense case we have to handle gracefully,
and correctly.  With correctness being the most important as otherwise
people might just send in nonsense to exploit bugs.

Completely agreed. Let's just start returning error if more than one of
the pid/fs/netnsid attributes is specified. I don't think this is going
to break any user. And we'll not have to care about the order.

I agree refusing to combine multiple attributes for the same thing
sounds the most sensible course.

Yes, please.

Thanks!

 Jiri