From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 23A821F95A for ; Fri, 17 Jan 2025 14:33:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737124426; cv=none; b=hDpcMVfokOHwhxq6jzJvXesVLZq83VUxdYbN9dNt8BRgUhptNaJEZCGwbG+W+AvtkBZ+3//Dle0WlaE92vKUUeSbmin5qAPcCVvQHJWXo2yxIRU8oCualcwnhaQOAJHDC0SJjQlXqbVqnxU3SX4L5RLCAfzm5r1iXTZ2QnJbY00= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737124426; c=relaxed/simple; bh=0z+SZUtfssSS8PYqgK9/T7Bm1X5L1dbhjGXJTdSE0k0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uBPxOTlLaClEjwAE/ftoTRJd0hpfrjwq/xvNX1UQmZY6UPFgdkeHIcQgCTn16vxpuYjNtd3rpwxjqyMzJFqFSM0dXgwBG4SZj3EDBME2S6Dz36yO+H3TVkC80K/IMCNdQ+88c157Gm3oHyRh8sAMRKqb3Qbs0cDcX/S5GU9qvXM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TGo8MzUZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TGo8MzUZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E619C4CEE1; Fri, 17 Jan 2025 14:33:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737124425; bh=0z+SZUtfssSS8PYqgK9/T7Bm1X5L1dbhjGXJTdSE0k0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=TGo8MzUZjuG2KpO7fuGDvwKijILtbylSCwrxDwcY2oYPA4i9N37K007kKPoOJQlFK XjK9J+2mIP9rmw8/7lRWQyziLZztaVLVwsUiyWutLvRgmlgHooz0CVVim8WxMVw5lD xH6RBqZOZAVuM1DIStwS9TfGJF1c4MssoknKeRDyZ8k0Jg57C9/GQELLHYaaiilAFX 8uPJxFdqz7pLz+4Qx09UK8Os4M13+SaeIur3eVVLxbml+wfL1LBexjBrHptlh2/KwI 6cLcp7jrkncyYKGdi58sQDGhZpBaSr3jOLKnE9+9X5oZRGrRetbkxyLNdasj2PN8P/ OREIzyUlhjZzQ== Message-ID: <34877829-ddd6-4d2d-858e-d057da9c1dba@kernel.org> Date: Fri, 17 Jan 2025 15:33:42 +0100 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-next 0/3] mptcp: blackhole: sysctl SYN retrans + fix conditions Content-Language: en-GB To: Mat Martineau Cc: mptcp@lists.linux.dev References: <20250114-mpc-no-blackhole-v1-0-994bd2a357fb@kernel.org> <99988d16-43a3-bdd3-c9e7-ccc992570eb2@kernel.org> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 8bit H Mat, On 17/01/2025 01:13, Mat Martineau wrote: > On Tue, 14 Jan 2025, Matthieu Baerts (NGI0) wrote: > >> Recently, I found a network having weird behaviours with MPTCP packets: >> >> - The first connection to a server had a successful 3WHS, then MPTCP >>  options got stripped off. >> >> - The next one had the first SYN (with or without MPTCP) and 5 >>  retransmissions dropped, before being apparently intercepted and >>  proxied to the end server. >> >> - (The next ones were sometimes intercepted, sometimes not, or dropped >>   at the beginning. I'm trying to find out which kind of "optimiser" is >>   causing this.) >> >> The result of this was a blackhole being "wrongly" detected, and no ways >> to force connections with quite a few SYN drops to finally use MPTCP at >> the end. >> >> In this series, we have: >> >> - A small fix for the doc. >> >> - A new sysctl to change the number of SYN retransmitted with MPTCP >>  options before falling back to TCP. The modification looks simple >>  enough to still be sent to netdev before the closure I think. >> > > Hi Matthieu - > > Patches 1 and 2 LGTM: > > Reviewed-by: Mat Martineau Thank you for the review! I already applied these two patches: New patches for t/upstream-net and t/upstream: - 34dc1c307f30: doc: mptcp: sysctl: blackhole_timeout is per-netns - Results: 1b76b0bd2522..551c1dba2a68 (export-net) - Results: 2a6dfa001e66..2d16bea74b90 (export) New patches for t/upstream: - 5fb87b001602: mptcp: sysctl: add syn_retrans_before_tcp_fallback - Results: 2d16bea74b90..b7be33140cc3 (export) Tests are now in progress: - export-net: https://github.com/multipath-tcp/mptcp_net-next/commit/70769bbce0f766c3583cb1caa791722685884f19/checks - export: https://github.com/multipath-tcp/mptcp_net-next/commit/caa6490e85f954f97ad955a2496c1b1297efee89/checks Cheers, Matt -- Sponsored by the NGI0 Core fund.