From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 36E3F41BA94 for ; Sat, 12 Sep 2026 09:15:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789204540; cv=none; b=jHuCUYLkQxLmrJOxH2HV6Fv4io39bQhkMyIq5Z9NHGWgtn54buW00fRkyIdd/e1TmmyMFvVGdzxSlGjbjc49X7wQFgrfQhVovBeNzesPMbAa8RvUyTkAQfc2DWKQ7TljMs2Xyl+1kZwkbMu66/9cjh0fOr59/p3GF7Zp+cUIoB8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789204540; c=relaxed/simple; bh=zpOGUySe6MA3ZA49CcjMkIEvdVwSCh7rDE9d7jE5Scs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Gf6ur64QVYmrpy9UPdSaRby3RGcWWiOA2hk2bOMWpqxjaWGYiwmia2Pmf9CDGJjQOMa5gh8M0ZonXfub+LXYo2Uui/VGhCqyKp1bB1mgpInfaGyeRQGI23ON906jsEkRTYeDewZHX/+tvX4dYsUZ9A0tiq2lJBNvrRD5OF0y7YI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A6JkvFst; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="A6JkvFst" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 248121F000FF; Sat, 12 Sep 2026 09:15:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789204535; bh=I6AIkUCM2YX4XU6ukcMNWosa5n0zlCzj+oYU7cNJqaU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=A6JkvFstLCLz4O+ZR9Pdi7i0QR3ZUOIyqddaSjRp+B6hpdvEuuz94GCcN4pu91xHr niGb/A1ymhzavP85UrEcsfjbogmM2DIsiYsE9LcYwilD16SApkxQfFqkAM7h2dkbiH dNqBkVJPSEuick77/z7XE7QPNY5+cYxtKGtUNkzMoPAiGERO9AdeiRk5SMO8w0J2VM y5yo833EXCSab36vL5k2Uy8hX+1fAhyWfDB2D4IJcbiEJLtPJW/0d1pczPtC/GRKBz fO7pegT3hH44qZfYcpcTCkz7yz5JJ7lUlqKeKZk/dNhEQ45cqvgsgfdTWHnlTTJ7Cr ErTXoJ2kSLHXw== Message-ID: <38df2211-f6b6-409d-80ae-de113601aff0@kernel.org> Date: Sat, 12 Sep 2026 11:15:32 +0200 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH mptcp-net v2 2/2] selftests: mptcp: join: retry connect after early fallback Content-Language: fr To: quanyeyang Cc: mptcp@lists.linux.dev References: <20260911-mptcp-connect-undo-net-v2-0-54224cea2238@proton.me> <20260911-mptcp-connect-undo-net-v2-2-54224cea2238@proton.me> <9f979653-9817-4daf-89a2-bb6394b406c6@kernel.org> <-ZGGpW4fRsw5nfnV8SiV4YNI0qeW_COcXZIfYFiTAtTRENexps8-vPd6Y1Z8DLUx9WWTLlHus0WJMuvbQ9zcB65LJI_w6GjGM5QY-HHRf2g=@proton.me> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/09/2026 10:42, quanyeyang wrote: > On Friday, September 11th, 2026 at AM 10:20, Matthieu Baerts wrote: > >> Thank you for this test, but we cannot accept this: it is good to have a >> test linked to a fix or a feature, but it has to be maintainable. If >> each fix/feature adds 300+ LoC, that's unmaintainable (or LLM become >> mandatory for that, but that's not what we want: we still need to be >> able to read the test). >> >> Ideally: >> >> - create a small packetdrill test instead, using the MPTCP version [1] >> >> - not everything can be tested with packetdrill (even if it can also be >> extended) and adding code in the selftests is OK, but, if possible, it >> should reuse the existing tools and helpers >> >> So in this case here: can you have a packetdrill test instead? It should >> be possible, no? If not, can you only use 'mptcp_connect' and the >> existing helpers from mptcp_join.sh? >> >> Also, mptcp_join.sh is to validate cases with multiple subflows. I don't >> think you need that, right? >> >> [1] https://github.com/multipath-tcp/packetdrill/ >> >> Cheers, >> Matt >> -- >> Sponsored by the NGI0 Core fund. >> >> > Thanks for the detailed guidance. > Agreed, 2/2 is too heavy. I will drop it and try to add a small packetdrill > script under gtests/net/mptcp/regressions/ instead: record a blackhole, > then fail connect() on the same fd before SS_CONNECTING, clear > blackhole_timeout, and check the retry still sends MP_CAPABLE > (TCP_IS_MPTCP / the 3rd ACK). Thanks, I think it should be easier and clearer to do that with packetdrill. > The kernel fix in v2 1/2 does not depend on that selftest. Could you > apply that one on its own? I can, but I prefer to have the new test first, to validate it with and without the modification. In other words, no need to resend patch 1. Cheers, Matt -- Sponsored by the NGI0 Core fund.