Re: [PATCH nft 2/2] evaluate: restore interval + concatenation in anonymous set

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Mon, Jun 14, 2021 at 01:56:44PM +0200, Pablo Neira Ayuso wrote:
> On Mon, Jun 14, 2021 at 01:34:03PM +0200, Phil Sutter wrote:
> > Hi Pablo,
> > 
> > On Fri, Jun 11, 2021 at 07:15:38PM +0200, Pablo Neira Ayuso wrote:
> > > Perform the table and set lookup only for non-anonymous sets, where the
> > > incremental cache update is required.
> > > 
> > > The problem fixed by 7aa08d45031e ("evaluate: Perform set evaluation on
> > > implicitly declared (anonymous) sets") resurrected after the cache
> > > rework.
> > > 
> > >  # nft add rule x y tcp sport . tcp dport vmap { ssh . 0-65535 : accept, 0-65535 . ssh : accept }
> > >  BUG: invalid range expression type concat
> > >  nft: expression.c:1422: range_expr_value_low: Assertion `0' failed.
> > >  Abort
> > > 
> > > Add a test case to make sure this does not happen again.
> > > 
> > > Fixes: 5ec5c706d993 ("cache: add hashtable cache for table")
> > > Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> > 
> > This triggers a warning:
> > 
> > evaluate.c: In function 'set_evaluate':
> > evaluate.c:3870:13: warning: 'table' may be used uninitialized in this function [-Wmaybe-uninitialized]
> >  3870 |         if (set_cache_find(table, set->handle.set.name) == NULL)
> >       |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Hm, this needs to be restricted to anonymous sets, attaching patch.

It's a false positive though, there is a check for anonymous set a few
lines before. I'll apply this patch if this makes gcc happy on your side.

> diff --git a/src/evaluate.c b/src/evaluate.c
> index 5311963a20c5..7cd90e2c1840 100644
> --- a/src/evaluate.c
> +++ b/src/evaluate.c
> @@ -3867,7 +3867,8 @@ static int set_evaluate(struct eval_ctx *ctx, struct set *set)
>  	}
>  	ctx->set = NULL;
>  
> -	if (set_cache_find(table, set->handle.set.name) == NULL)
> +	if (!(set->flags & NFT_SET_ANONYMOUS) &&
> +	    !set_cache_find(table, set->handle.set.name))
>  		set_cache_add(set_get(set), table);
>  
>  	return 0;