From nobody Thu Sep 19 00:55:23 2024 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 F3E4D83CA1 for ; Fri, 19 Jul 2024 12:24:39 +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=1721391880; cv=none; b=ncHra7lwDpmRdLm0k7GxwxdHYHyfBolfOq5S9PuuD7DJOqycrLnfx6DpIP4KuUxYEZPoC/LviWmq6j2bbd6soJs//EAKoVqNGo62W0lSWFbaRV52rojJDrano9HKRk1lrHoU6MEgGZ0eeJShX93qG4cs5/P+mnzXS1q9tJl7hkw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721391880; c=relaxed/simple; bh=i77z9tOTtHs5P1x2DEPDtVt0aXpXalQv5SfvpCPktr0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=XuSFd2vh8bAsb9rThonkm5x+G07HjxJ/9+Zg2+orE6ialcST2Qv4hC4QShyH5sNIJ+g8As46aGgY+RzMNY1tZKNpOAPo641FMQONX+oAjYkmh4Pag9Zfh4LS5schpiAlgfMFqKi8bYqXRInivFH7sHhFCBHKKHTHs4yisXehuGE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OF5b8q7Z; 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="OF5b8q7Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6769C4AF09; Fri, 19 Jul 2024 12:24:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721391879; bh=i77z9tOTtHs5P1x2DEPDtVt0aXpXalQv5SfvpCPktr0=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=OF5b8q7ZwkLpaoS5Q4BJ0c4kBcgTFYro7JrSg+5JN5x/IvGlsGvh0GgCENpxq0OkC K6x6+Gd4c+LhT7g9f1deh8wZtFrby8JqMeIWS8s3DyxJtQ4yrQGNr/hLls3KOHcZx1 AC4ZNAjeEBc/lVyAc/NHGtPe2Wu8dnekPICRfnubFkPv+vYCf/XzhxNH1/1ElPm3P4 N7XJXZ1jCR4TQafHdhUC2Q31wJmkEQjugtGwNsVY3J/nP0snpvfc5d3Z5Td80GOozV Wk2bTb+DxYEjFEkQCZ2jHOVTcLNeRibwgewEL+HXNuyedhuaMvlI1DCQiSJjzIBahH 0wFaHdaWD73tA== From: "Matthieu Baerts (NGI0)" Date: Fri, 19 Jul 2024 14:24:16 +0200 Subject: [PATCH mptcp-net v3 05/20] mptcp: pm: do not ignore 'subflow' if 'signal' flag is also set Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20240719-mptcp-pm-avail-v3-5-e96b5591ced3@kernel.org> References: <20240719-mptcp-pm-avail-v3-0-e96b5591ced3@kernel.org> In-Reply-To: <20240719-mptcp-pm-avail-v3-0-e96b5591ced3@kernel.org> To: mptcp@lists.linux.dev Cc: Paolo Abeni , "Matthieu Baerts (NGI0)" X-Mailer: b4 0.14.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3907; i=matttbe@kernel.org; h=from:subject:message-id; bh=i77z9tOTtHs5P1x2DEPDtVt0aXpXalQv5SfvpCPktr0=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBmmlr/xHsih0kF7d7BonDcxQxAgeak2r7lGAL3H yIBBYwc22KJAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZppa/wAKCRD2t4JPQmmg c2XvD/9l2PGUfYlbC23PevWrbvfYkf8CO79ULSIvYRB5H7M995vGdWhb8+AWCxN8FH0TTW36d4i xPxdy/iBzpXrgYGhrVVzoA6d93CHp0JVeyOClXSRiVwEMHb1OnKMXwpm3UE49ERV9oKFcH2YyRV RyoKB1ZLNFiIhfDaip8vwqFygsLOwZrLhQ7DdcfsOzx2tRRH6e11vsDsSkAlwA3QOHZ1pBaRcxp /3sU4CnXgBGxgKNOjSvWotJKYDH+cjakUVP938exUN8/M3EvaUf4Dky70DI0ryXI0koPtIiJ0pT uDbgrQAy3brCx2MpvY56Vxw7dX9JKcIJIac6ZLJGXhUUiSv3AP77vFOYDvMUJrB0M+9y8gtE+Da vMKBEsso1saBONGUEGtZoJa/0QEPu8Hm7uCqauodYa5W/7naEQxk2GooqXBHUND+UoKXOik5Kzf 3htVc/5b+ObBFVUIu3pbrzy0Sxo/U5zMH1Zim3OreGfA0wJRrUZ+Kpz1YgZbZ7bQWbv+vWfMZ3H m4uUb6keq6W0TNpZ6uZUKJ+HnYjvrQqxnILi1jW7NN5S44rQAO30noI3WDIU2ACZa0TK9ltKAwT y9leBq6vbXSKlygAucbnqINyMDy5CHaEQWg+xqmzXnQbAroQ/o1me2y0skMqncTu+G/xLQ4BwmC afCRU8geE9D0TbQ== X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 Up to the 'Fixes' commit, having an endpoint with both the 'signal' and 'subflow' flags, resulted in the creation of a subflow and an address announcement using the address linked to this endpoint. After this commit, only the address announcement was done, ignoring the 'subflow' flag. That's because the same bitmap is used for the two flags. It is OK to keep this single bitmap, the already selected local endpoint simply have to be re-used, but not via select_local_address() not to look at the just modified bitmap. Note that it is unusual to set the two flags together: creating a new subflow using a new local address will implicitly advertise it to the other peer. So in theory, no need to advertise it explicitly as well. Maybe there are use-cases -- the subflow might not reach the other peer that way, we can ask the other peer to try initiating the new subflow without delay -- or very likely the user is confused, and put both flags "just to be sure at least the right one is set". Still, if it is allowed, the kernel should do what has been asked: using this endpoint to announce the address and to create a new subflow from it. An alternative is to forbid the use of the two flags together, but that's probably too late, there are maybe use-cases, and it was working before. This patch will avoid people complaining subflows are not created using the endpoint they added with the 'subflow' and 'signal' flag. Note that with the current patch, the subflow might not be created in some corner cases, e.g. if the 'subflows' limit was reached when sending the ADD_ADDR, but changed later on. It is probably not worth splitting id_avail_bitmap per target ('signal', 'subflow'), which will add another large field to the msk "just" to track (again) endpoints. Anyway, currently when the limits are changed, the kernel doesn't check if new subflows can be created or removed, because we would need to keep track of the received ADD_ADDR, and more. It sounds OK to assume that the limits should be properly configured before establishing new connections. Fixes: 86e39e04482b ("mptcp: keep track of local endpoint still available f= or each msk") Suggested-by: Paolo Abeni Signed-off-by: Matthieu Baerts (NGI0) --- Notes: - v2: re-use the same bitmap instead of duplicating it for each target (Paolo) --- net/mptcp/pm_netlink.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 0ca6b358ab51..2e94f2a9f2a6 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -513,8 +513,8 @@ __lookup_addr(struct pm_nl_pernet *pernet, const struct= mptcp_addr_info *info) =20 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) { + struct mptcp_pm_addr_entry *local, *signal_and_subflow =3D NULL; struct sock *sk =3D (struct sock *)msk; - struct mptcp_pm_addr_entry *local; unsigned int add_addr_signal_max; unsigned int local_addr_max; struct pm_nl_pernet *pernet; @@ -580,6 +580,9 @@ static void mptcp_pm_create_subflow_or_signal_addr(stru= ct mptcp_sock *msk) msk->pm.add_addr_signaled++; mptcp_pm_announce_addr(msk, &local->addr, false); mptcp_pm_nl_addr_send_ack(msk); + + if (local->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) + signal_and_subflow =3D local; } =20 subflow: @@ -590,9 +593,14 @@ static void mptcp_pm_create_subflow_or_signal_addr(str= uct mptcp_sock *msk) bool fullmesh; int i, nr; =20 - local =3D select_local_address(pernet, msk); - if (!local) - break; + if (signal_and_subflow) { + local =3D signal_and_subflow; + signal_and_subflow =3D NULL; + } else { + local =3D select_local_address(pernet, msk); + if (!local) + break; + } =20 fullmesh =3D !!(local->flags & MPTCP_PM_ADDR_FLAG_FULLMESH); =20 --=20 2.45.2