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 DE1F128399; Mon, 8 Sep 2025 17:31:48 +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=1757352709; cv=none; b=RXt+8fPeLht4hOLPaWnvZEJ3AJMhXdO8G6xRQIZOtRHJBzNAwljQivOnKaPDlQoLb6qivPmPoAkI1z8tlZKltvJMMxPut/BbXC0ifkclRLRB+gcpuBCUif0t/laeb4u+g7yU3NPgcy4IHaH7GeqBivpO+pkeo2ZW9CIfvzqZ7cM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757352709; c=relaxed/simple; bh=+GJvdWbYdEkO2iexLk7YraWW+Q1K7c80iEct8a7Ig08=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=myFgTMlijUpivlObkhpf9SM+gz/89mPcn1pnyCqQIs0INvVmEk64ufNcAb1Pqx2BAII23TTy3jgGE74BgI9AsNKHwaH4bbLYxFeaKDE7aU9HRF0mA5/nZeYUx45aFGiIarY6u3WKBvrZzTFmmOWwpGt25uO9c5FTH6UxCTb3/7c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nKb0Vaa6; 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="nKb0Vaa6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2627C4CEF1; Mon, 8 Sep 2025 17:31:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757352708; bh=+GJvdWbYdEkO2iexLk7YraWW+Q1K7c80iEct8a7Ig08=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=nKb0Vaa6R6NYNEhMOdCuSCZp+oUbllfgqCTq09Di+mi3HR05l7lLTtqUXO2QiPh5D 2TkhXqVhsnCGDCILeuJ3Th5CZnGG/+Qy0vxAG1rQ7kOTmpDbwoxX0SpIlmc6yizT2u PBjtsWe4axam2aOM6I6nsko6txOuJ921r9tItcjIzmsK4kpJs9uFkg+dnjPocJxG6E i08+j0L54EyL4hquPoVsrO70xn22r89elZosE1O65Jzv/BIyWhEOE9/iwQNlQFw4EX gEEuvbp2hHx3njq3vEXg+8sgwjfCPgqFs8D8t63V0nQP0r8cronoUzyfFtmzjAPQDa lV0LtmAheILWg== Message-ID: <23a66a02-7de9-40c5-995d-e701cb192f8b@kernel.org> Date: Mon, 8 Sep 2025 19:31:43 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH mptcp] mptcp: sockopt: make sync_socket_options propagate SOCK_KEEPOPEN Content-Language: en-GB, fr-BE To: Krister Johansen Cc: Geliang Tang , Mat Martineau , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Florian Westphal , netdev@vger.kernel.org, mptcp@lists.linux.dev, linux-kernel@vger.kernel.org, David Reaver References: <83191d507b7bc9b0693568c2848319932e6b974e.camel@kernel.org> <78d4a7b8-8025-493a-805c-a4c5d26836a8@kernel.org> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; keydata= xsFNBFXj+ekBEADxVr99p2guPcqHFeI/JcFxls6KibzyZD5TQTyfuYlzEp7C7A9swoK5iCvf YBNdx5Xl74NLSgx6y/1NiMQGuKeu+2BmtnkiGxBNanfXcnl4L4Lzz+iXBvvbtCbynnnqDDqU c7SPFMpMesgpcu1xFt0F6bcxE+0ojRtSCZ5HDElKlHJNYtD1uwY4UYVGWUGCF/+cY1YLmtfb WdNb/SFo+Mp0HItfBC12qtDIXYvbfNUGVnA5jXeWMEyYhSNktLnpDL2gBUCsdbkov5VjiOX7 CRTkX0UgNWRjyFZwThaZADEvAOo12M5uSBk7h07yJ97gqvBtcx45IsJwfUJE4hy8qZqsA62A nTRflBvp647IXAiCcwWsEgE5AXKwA3aL6dcpVR17JXJ6nwHHnslVi8WesiqzUI9sbO/hXeXw TDSB+YhErbNOxvHqCzZEnGAAFf6ges26fRVyuU119AzO40sjdLV0l6LE7GshddyazWZf0iac nEhX9NKxGnuhMu5SXmo2poIQttJuYAvTVUNwQVEx/0yY5xmiuyqvXa+XT7NKJkOZSiAPlNt6 VffjgOP62S7M9wDShUghN3F7CPOrrRsOHWO/l6I/qJdUMW+MHSFYPfYiFXoLUZyPvNVCYSgs 3oQaFhHapq1f345XBtfG3fOYp1K2wTXd4ThFraTLl8PHxCn4ywARAQABzSRNYXR0aGlldSBC YWVydHMgPG1hdHR0YmVAa2VybmVsLm9yZz7CwZEEEwEIADsCGwMFCwkIBwIGFQoJCAsCBBYC AwECHgECF4AWIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZUDpDAIZAQAKCRD2t4JPQmmgcz33 EACjROM3nj9FGclR5AlyPUbAq/txEX7E0EFQCDtdLPrjBcLAoaYJIQUV8IDCcPjZMJy2ADp7 /zSwYba2rE2C9vRgjXZJNt21mySvKnnkPbNQGkNRl3TZAinO1Ddq3fp2c/GmYaW1NWFSfOmw MvB5CJaN0UK5l0/drnaA6Hxsu62V5UnpvxWgexqDuo0wfpEeP1PEqMNzyiVPvJ8bJxgM8qoC cpXLp1Rq/jq7pbUycY8GeYw2j+FVZJHlhL0w0Zm9CFHThHxRAm1tsIPc+oTorx7haXP+nN0J iqBXVAxLK2KxrHtMygim50xk2QpUotWYfZpRRv8dMygEPIB3f1Vi5JMwP4M47NZNdpqVkHrm jvcNuLfDgf/vqUvuXs2eA2/BkIHcOuAAbsvreX1WX1rTHmx5ud3OhsWQQRVL2rt+0p1DpROI 3Ob8F78W5rKr4HYvjX2Inpy3WahAm7FzUY184OyfPO/2zadKCqg8n01mWA9PXxs84bFEV2mP VzC5j6K8U3RNA6cb9bpE5bzXut6T2gxj6j+7TsgMQFhbyH/tZgpDjWvAiPZHb3sV29t8XaOF BwzqiI2AEkiWMySiHwCCMsIH9WUH7r7vpwROko89Tk+InpEbiphPjd7qAkyJ+tNIEWd1+MlX ZPtOaFLVHhLQ3PLFLkrU3+Yi3tXqpvLE3gO3LM7BTQRV4/npARAA5+u/Sx1n9anIqcgHpA7l 5SUCP1e/qF7n5DK8LiM10gYglgY0XHOBi0S7vHppH8hrtpizx+7t5DBdPJgVtR6SilyK0/mp 9nWHDhc9rwU3KmHYgFFsnX58eEmZxz2qsIY8juFor5r7kpcM5dRR9aB+HjlOOJJgyDxcJTwM 1ey4L/79P72wuXRhMibN14SX6TZzf+/XIOrM6TsULVJEIv1+NdczQbs6pBTpEK/G2apME7vf mjTsZU26Ezn+LDMX16lHTmIJi7Hlh7eifCGGM+g/AlDV6aWKFS+sBbwy+YoS0Zc3Yz8zrdbi Kzn3kbKd+99//mysSVsHaekQYyVvO0KD2KPKBs1S/ImrBb6XecqxGy/y/3HWHdngGEY2v2IP Qox7mAPznyKyXEfG+0rrVseZSEssKmY01IsgwwbmN9ZcqUKYNhjv67WMX7tNwiVbSrGLZoqf Xlgw4aAdnIMQyTW8nE6hH/Iwqay4S2str4HZtWwyWLitk7N+e+vxuK5qto4AxtB7VdimvKUs x6kQO5F3YWcC3vCXCgPwyV8133+fIR2L81R1L1q3swaEuh95vWj6iskxeNWSTyFAVKYYVskG V+OTtB71P1XCnb6AJCW9cKpC25+zxQqD2Zy0dK3u2RuKErajKBa/YWzuSaKAOkneFxG3LJIv Hl7iqPF+JDCjB5sAEQEAAcLBXwQYAQIACQUCVeP56QIbDAAKCRD2t4JPQmmgc5VnD/9YgbCr HR1FbMbm7td54UrYvZV/i7m3dIQNXK2e+Cbv5PXf19ce3XluaE+wA8D+vnIW5mbAAiojt3Mb 6p0WJS3QzbObzHNgAp3zy/L4lXwc6WW5vnpWAzqXFHP8D9PTpqvBALbXqL06smP47JqbyQxj Xf7D2rrPeIqbYmVY9da1KzMOVf3gReazYa89zZSdVkMojfWsbq05zwYU+SCWS3NiyF6QghbW voxbFwX1i/0xRwJiX9NNbRj1huVKQuS4W7rbWA87TrVQPXUAdkyd7FRYICNW+0gddysIwPoa KrLfx3Ba6Rpx0JznbrVOtXlihjl4KV8mtOPjYDY9u+8x412xXnlGl6AC4HLu2F3ECkamY4G6 UxejX+E6vW6Xe4n7H+rEX5UFgPRdYkS1TA/X3nMen9bouxNsvIJv7C6adZmMHqu/2azX7S7I vrxxySzOw9GxjoVTuzWMKWpDGP8n71IFeOot8JuPZtJ8omz+DZel+WCNZMVdVNLPOd5frqOv mpz0VhFAlNTjU1Vy0CnuxX3AM51J8dpdNyG0S8rADh6C8AKCDOfUstpq28/6oTaQv7QZdge0 JY6dglzGKnCi/zsmp2+1w559frz4+IC7j/igvJGX4KDDKUs0mlld8J2u2sBXv7CGxdzQoHaz lzVbFe7fduHbABmYz9cefQpO7wDE/Q== Organization: NGI0 Core In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Krister, On 08/09/2025 19:25, Krister Johansen wrote: > On Mon, Sep 08, 2025 at 07:13:12PM +0200, Matthieu Baerts wrote: >> Hi Geliang, >> >> On 07/09/2025 02:51, Geliang Tang wrote: >>> Hi Matt, >>> >>> On Sat, 2025-09-06 at 15:26 +0200, Matthieu Baerts wrote: >>>> Hi Krister, >>>> >>>> On 06/09/2025 02:43, Krister Johansen wrote: >>>>> Users reported a scenario where MPTCP connections that were >>>>> configured >>>>> with SO_KEEPALIVE prior to connect would fail to enable their >>>>> keepalives >>>>> if MTPCP fell back to TCP mode. >>>>> >>>>> After investigating, this affects keepalives for any connection >>>>> where >>>>> sync_socket_options is called on a socket that is in the closed or >>>>> listening state.  Joins are handled properly. For connects, >>>>> sync_socket_options is called when the socket is still in the >>>>> closed >>>>> state.  The tcp_set_keepalive() function does not act on sockets >>>>> that >>>>> are closed or listening, hence keepalive is not immediately >>>>> enabled. >>>>> Since the SO_KEEPOPEN flag is absent, it is not enabled later in >>>>> the >>>>> connect sequence via tcp_finish_connect.  Setting the keepalive via >>>>> sockopt after connect does work, but would not address any >>>>> subsequently >>>>> created flows. >>>>> >>>>> Fortunately, the fix here is straight-forward: set SOCK_KEEPOPEN on >>>>> the >>>>> subflow when calling sync_socket_options. >>>>> >>>>> The fix was valdidated both by using tcpdump to observe keeplaive >>>>> packets not being sent before the fix, and being sent after the >>>>> fix.  It >>>>> was also possible to observe via ss that the keepalive timer was >>>>> not >>>>> enabled on these sockets before the fix, but was enabled >>>>> afterwards. >>>> >>>> >>>> Thank you for the fix! Indeed, the SOCK_KEEPOPEN flag was missing! >>>> This >>>> patch looks good to me as well: >>>> >>>> Reviewed-by: Matthieu Baerts (NGI0) >>>> >>>> >>>> @Netdev Maintainers: please apply this patch in 'net' directly. But I >>>> can always re-send it later if preferred. >>> >>> nit: >>> >>> I just noticed his patch breaks 'Reverse X-Mas Tree' order in >>> sync_socket_options(). If you think any changes are needed, please >>> update this when you re-send it. >> >> Sure, I can do the modification and send it with other fixes we have. > > Thanks for the reviews, Geliang and Matt. If you'd like me to fix the > formatting up and send a v2, I'm happy to do that as well. Just let me > know. I was going to apply this diff: > diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c > index 13108e9f982b..2abe6f1e9940 100644 > --- a/net/mptcp/sockopt.c > +++ b/net/mptcp/sockopt.c > @@ -1532,11 +1532,12 @@ static void sync_socket_options(struct mptcp_sock *msk, struct sock *ssk) > { > static const unsigned int tx_rx_locks = SOCK_RCVBUF_LOCK | SOCK_SNDBUF_LOCK; > struct sock *sk = (struct sock *)msk; > - int kaval = !!sock_flag(sk, SOCK_KEEPOPEN); > + bool keep_open; > > + keep_open = sock_flag(sk, SOCK_KEEPOPEN); > if (ssk->sk_prot->keepalive) > - ssk->sk_prot->keepalive(ssk, kaval); > - sock_valbool_flag(ssk, SOCK_KEEPOPEN, kaval); > + ssk->sk_prot->keepalive(ssk, keep_open); > + sock_valbool_flag(ssk, SOCK_KEEPOPEN, keep_open); > > ssk->sk_priority = sk->sk_priority; > ssk->sk_bound_dev_if = sk->sk_bound_dev_if; (sock_flag() returns a bool, and 'keep_open' is maybe clearer) But up to you, I really don't mind if you prefer to send the v2 by yourself, just let me know. Cheers, Matt -- Sponsored by the NGI0 Core fund.