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 9201E265620 for ; Wed, 22 Apr 2026 08:50:55 +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=1776847855; cv=none; b=hg5hXVSrH9lA6dh31ygw6oB3uW3NKpGo41B/LRrBFMFLw+cvoDV+Pmz1Jo5fxLY8TJptW1MKtjULbMvh7iV5TnajVzU9wbQJvDobBkgexlB/5trreaO1N/CfAS28xN79gmGA381L0kilZdHQKcf/wt3gLoSbu2UH2imjvxbbeEI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776847855; c=relaxed/simple; bh=NBtac0Pds67naRWyfp0kTCbvTpLeyNzryQehLLInA34=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CqzUpeWiIsHTz/v7HLrzc6bcxT1d8G5+Xk+z5OkRb+RT4ev5xCp0njomm86EoKf8Ti+7A4XVhHp4X/vwodAhJsdb/K0uMYs2FD3SloFAI7kaBM1HeG7TAV3t4c5rVLTmXl76/oitUgLdGXpzcdqq9tHrPfuN4LRBGtk9VOcEjog= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IJJT9atn; 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="IJJT9atn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF457C2BCB4; Wed, 22 Apr 2026 08:50:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776847855; bh=NBtac0Pds67naRWyfp0kTCbvTpLeyNzryQehLLInA34=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=IJJT9atn1bEu9UMk88Qzr2GdTDUgeRA++Sf4KAZgl/icTkY4lZRDOqlR399GrtZOi N7OGRWecyVuDh2q7FC1uoc2VoEUMrTAPQPjmUB/uPIhVYWp/YvvDVeptIvoZfwYPfQ trqgW1spqxnEKFXyZ6EToDcpFnWlEWNPvdcJFLz6ag/Cbwqj8ePxdvVEqj1JD2R3Sn Y4QfQ24Vl9P9xzBBnfV6gacf4exgYCXRErZqoiWq/L64XPIoJNzQbR4OUraa/PPrDG OGBaSz5UNpmzbP1sbQXWTED3FjTURAJAb9dVPd1sRe9i4QkwEOHVtDGm0YEaib1/tM 063fAYROpDhgg== Message-ID: <0d414fe6-1775-4181-b6a7-9649c11c87ad@kernel.org> Date: Wed, 22 Apr 2026 10:50:51 +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-next v3 1/3] mptcp: propagate RECVERR sockopts to subflows Content-Language: fr To: Paolo Abeni Cc: Mat Martineau , Geliang Tang , David Carlier , mptcp@lists.linux.dev References: <20260421223338.52743-1-devnexen@gmail.com> <20260421223338.52743-2-devnexen@gmail.com> <88df3189-4aa0-41fa-9a58-0d17fb736c87@kernel.org> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 22/04/2026 10:48, Paolo Abeni wrote: > On 4/22/26 10:35 AM, Matthieu Baerts wrote: >> On 22/04/2026 10:32, Matthieu Baerts wrote: >>> On 22/04/2026 10:05, Paolo Abeni wrote: >>>> On 4/22/26 12:33 AM, David Carlier wrote: >>>>> Propagate IP_RECVERR/IP_RECVERR_RFC4884 and >>>>> IPV6_RECVERR/IPV6_RECVERR_RFC4884 from the MPTCP socket to >>>>> existing and future subflows. >>>>> >>>>> Apply the matching sockopt according to the subflow family so mixed- >>>>> family subflows stay aligned with the parent socket configuration, >>>>> including disable-time errqueue purge semantics. >>> >>> (...) >>> >>>>> +static int mptcp_setsockopt_v6_recverr(struct mptcp_sock *msk, int optname, >>>>> + sockptr_t optval, unsigned int optlen) >>>>> +{ >>>>> + struct mptcp_subflow_context *subflow; >>>>> + struct sock *sk = (struct sock *)msk; >>>>> + int ret; >>>>> + >>>>> + ret = ipv6_setsockopt(sk, SOL_IPV6, optname, optval, optlen); >>>>> + if (ret) >>>>> + return ret; >>>>> + >>>>> + lock_sock(sk); >>>>> + sockopt_seq_inc(msk); >>>>> + mptcp_for_each_subflow(msk, subflow) { >>>>> + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); >>>>> + bool rfc4884 = optname == IPV6_RECVERR_RFC4884; >>>>> + >>>>> + ret = mptcp_subflow_set_recverr(sk, ssk, rfc4884); >>>> >>>> The above looks a bit overcomplicated?!? It looks like you could >>>> leverage mptcp_setsockopt_all_sf() in and drop the >>>> mptcp_subflow_set_recverr() and mptcp_recverr_enabled() helpers. >>>> >>>> @Mattbe: it's not clear to me why mptcp_setsockopt_all_sf() does not >>>> call sockopt_seq_inc(msk) or sync the setsockopt_seq, possibly an >>>> unrelated bug? >>> >>> Oh yes, good catch! And a lock of the sk (msk) before iterating the >>> subflows, no? Same in __mptcp_setsockopt_set_val()? >> >> (Not the same in __mptcp_setsockopt_set_val(): the sk is already locked) > > AFAICS for mptcp_setsockopt_all_sf() the msk lock is acquired by the > caller. Same for __mptcp_setsockopt_set_val(). > > Side note; AFAICS a few other paths apparently lack the setsockopt_seq; > that is minor problem/not a real issue: worst case it will cause a > redundant mptcp_sockopt_sync_locked() call at finish_join time. > > The missing sockopt_seq_inc() instead looks really bogus, as it will > caused missing synchronization for later subflows. Good point! Do you want me to send a patch, or do you already have one? (or do you plan to look at it) Cheers, Matt -- Sponsored by the NGI0 Core fund.