Re: [nft PATCH] tests: shell: Fix sets/reset_command_0 for current kernels

[Phil Sutter <phil@nwl.cc>]

On Thu, Nov 02, 2023 at 09:32:30PM +0100, Pablo Neira Ayuso wrote:
> On Thu, Nov 02, 2023 at 06:06:34PM +0100, Phil Sutter wrote:
> > On Thu, Nov 02, 2023 at 04:29:34PM +0100, Thomas Haller wrote:
> > > On Thu, 2023-11-02 at 16:03 +0100, Phil Sutter wrote:
> > > >  
> > > > +# Note: Element expiry is no longer reset since kernel commit
> > > > 4c90bba60c26
> > > > +# ("netfilter: nf_tables: do not refresh timeout when resetting
> > > > element"),
> > > > +# the respective parts of the test have therefore been commented
> > > > out.
> > > 
> > > Hi Phil,
> > > 
> > > do you expect that the old behavior ever comes back?
> > 
> > A recent nfbz comment[1] from Pablo made me doubt the decision is final,
> > though I may have misread it.
> 
> I hesitate on changing --stateless behaviour, but I don't find a
> usecase for this option all alone unless it is combined with --terse,
> to store an initial ruleset skeleton with no elements and no states.
> Sets with timeout likely contain elements that get dynamically added
> either via control plane or packet path based on some heuristics.

Unrelated to the expires vs. reset question, I wonder if one should
treat set elements with timeout as state themselves. If one leaves the
ruleset alone for long enough, they all will eventually vanish. So one
may argue the ruleset in its stateless form does not have elements in a
set with defined timeout.

> > > Why keep the old checks (commented out)? Maybe drop them? We can get it
> > > from git history.
> > 
> > Should the change be permanent, one should change the tests to assert
> > the opposite, namely that expires values are unaffected by the reset.
> 
> I think it is fine as it is now in the kernel. I have posted patches
> to allow to update element timeouts via transaction, which looks more
> flexible and run through the transaction path. As for counter and
> quota, users likely only want to either: 1) restore a previous state
> (after reboot) or 2) dump-and-reset counters for stats collection
> (e.g. fetch counters at the end of the day).

I still doubt there's a use-case to do (1) or (2) in sets with
temporary elements.

Cheers, Phil