From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(No client certificate requested)
	by smtp.subspace.kernel.org (Postfix) with ESMTPS id B6E9937F74C;
	Thu, 11 Jun 2026 23:12:43 +0000 (UTC)
Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.216.245.30
ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;
	t=1781219565; cv=none; b=oDSXUxhJYeiKxWxJ7/WsxtR0kM/M4+bndzZ5LmlTrWcsCckpOTaXw77qk+9U5qJ3wp0s47dscPmH5N1rCY+U3UGPCueVZ5dWnFUTVr8aeWDrAG8LVw8Fh2lx5xNM0S6Ur6tVclAKT3UCsFZ+YAPS6W+dKPUrc2vq40G0coJlnG8=
ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org;
	s=arc-20240116; t=1781219565; c=relaxed/simple;
	bh=KLe3hk5VUfU8noaxNmRkNEhMu7EBz0zeqqyDmsnIcAE=;
	h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:
	 Content-Type:Content-Disposition:In-Reply-To; b=BQzBF21EbrYRTvh9d/GBdQ2eCcne1GElycsJoF8DGNyLRBUAqYzieSaWo2QEQSCdXnBwdkriyAYhPXX+LLreV/uRT8hAPKDOWPWmme0+dGNpow8xyjA12nfDKu+KlMRUkPFp4kxS3mIy9qgmZ2uAgRjurbA6NAVAAroahE++JjE=
ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de; spf=pass smtp.mailfrom=strlen.de; arc=none smtp.client-ip=91.216.245.30
Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de
Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=strlen.de
Received: by Chamillionaire.breakpoint.cc (Postfix, from userid 1003)
	id 58793602B9; Fri, 12 Jun 2026 01:12:35 +0200 (CEST)
Date: Fri, 12 Jun 2026 01:12:33 +0200
From: Florian Westphal <fw@strlen.de>
To: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org, netfilter-devel@vger.kernel.org
Subject: Re: [PATCH net-next 1/2] netdevsim: tc: allow to test nf_tables
 offload control plane code
Message-ID: <aitA4f_9YaQV-I_l@strlen.de>
References: <20260610175906.1767-1-fw@strlen.de>
 <20260610175906.1767-2-fw@strlen.de>
 <20260611133910.2887266f@kernel.org>
Precedence: bulk
X-Mailing-List: netfilter-devel@vger.kernel.org
List-Id: <netfilter-devel.vger.kernel.org>
List-Subscribe: <mailto:netfilter-devel+subscribe@vger.kernel.org>
List-Unsubscribe: <mailto:netfilter-devel+unsubscribe@vger.kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20260611133910.2887266f@kernel.org>

Jakub Kicinski <kuba@kernel.org> wrote:
> On Wed, 10 Jun 2026 19:58:43 +0200 Florian Westphal wrote:
> > @@ -73,7 +86,10 @@ nsim_setup_tc(struct net_device *dev, enum tc_setup_type type, void *type_data)
> >  						  &nsim_block_cb_list,
> >  						  nsim_setup_tc_block_cb,
> >  						  ns, ns, true);
> > +	case TC_SETUP_FT:
> > +		return 0;
> >  	default:
> >  		return -EOPNOTSUPP;
> >  	}
> >  }
> > +ALLOW_ERROR_INJECTION(nsim_setup_tc, ERRNO);
> 
> As you probably seen other netdevsim offloads use explicit debugfs 
> files to "fail operation X". Slightly easier to deal with, and
> netdevsim is a test harness anyway. But entirely up to you.

I'd rather not reimplement the '30% failure rate' and the 'make-it-fail'
logic (allows to have restrict the error injection to selected
processed), so I would prefer to give fuzzers more rope.

I'll fix up the sashiko hints in v2.