From patchwork Fri Nov 8 15:52:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthieu Baerts X-Patchwork-Id: 13868404 X-Patchwork-Delegate: bpf@iogearbox.net 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 B1DAC1F1309; Fri, 8 Nov 2024 15:52:51 +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=1731081171; cv=none; b=YsldXK0y5lubwKrOzXW5vMHySTSmlPtmyhDQxZRtpHaAlp/mtWgWWH+eAlfiuVKRzzfDwtmEvujgSBIwYLinOVzvnDob/cfgxeBl5CIn6PAHzc503BhpXZTWYZ156J29gI3cOxskEQ38H1fs93GXMRUsUmHGIuDZt3u+hjavpD4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731081171; c=relaxed/simple; bh=5YOsiNLttKWq/Ld5/UcsEwz3pOgckJnPsrplRWCy/8I=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=nUlflTQcujVrvF0Cp5MwCO7m0T7NJKCNk4Vm4fk6qVDx9AK47l68EpnouUe//kb/h5E/j8b9+MRaspq4je8V3HJmDGuJGOyrYL7AxEI87sRWpgOjHX0LY/pHbDxCBGfP8KqRYlYhzhlb53j7/EbLwbpbof//pzS8eC7WgIGZHdI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rPWC2ITA; 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="rPWC2ITA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0E12C4CECF; Fri, 8 Nov 2024 15:52:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731081171; bh=5YOsiNLttKWq/Ld5/UcsEwz3pOgckJnPsrplRWCy/8I=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=rPWC2ITAror8Lf7cW4cwwjzc0+hKHbNUU5OoXRGWjq4gkn5PS6QcflF53Mn7rFBY1 k4PSz+Mhmaj+0OqnhW0eB0kov8s/8jo3tWCysXk/PZuk3LpqMaKoSJHtMxCaE67IhD +xpxtdHeIArCMNdobuQI/iCNVBc7bC3D+OiVBH/cVczFJsoPkxKJ/LoO/JUlUPx5RX eejCXBezecJNxZUGtcEy2etXOe2KHJY/UjwDHAR5VMqV6mBrac3JQbBBXDa9/yPyXH EWA9KG1q/FiqgGEpxBTwldvgtCp5kMEzFT6OguA6JQDhdV8tf+zNl9I69d/XNvJL5r yaabMG3r4LtSw== From: "Matthieu Baerts (NGI0)" Date: Fri, 08 Nov 2024 16:52:31 +0100 Subject: [PATCH bpf-next/net 2/5] bpf: Add mptcp_subflow bpf_iter Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241108-bpf-next-net-mptcp-bpf_iter-subflows-v1-2-cf16953035c1@kernel.org> References: <20241108-bpf-next-net-mptcp-bpf_iter-subflows-v1-0-cf16953035c1@kernel.org> In-Reply-To: <20241108-bpf-next-net-mptcp-bpf_iter-subflows-v1-0-cf16953035c1@kernel.org> To: mptcp@lists.linux.dev, Mat Martineau , Geliang Tang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Mykola Lysenko , Shuah Khan Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, "Matthieu Baerts (NGI0)" , Martin KaFai Lau , Geliang Tang X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=4014; i=matttbe@kernel.org; h=from:subject:message-id; bh=fOkGqZrxlK74TDATl6N8SPLqzPotdmdaTyOO796PIMA=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBnLjPBQpqi3TslQuEySuqdIlV0AeBwFGoYyH1An 4OxKAv1vsiJAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZy4zwQAKCRD2t4JPQmmg c5aSEADuM56/WyZWe95dcwS5CL/3VBCSv+tlShGKbXwQX853Citmxfz+8r8m5YketqCZY745akl 8CSB18sWzc7DW0QqBHD3zT8n9hwPelASdxVfxwuLMuWExvwL9G0tVdGqMSNEJ/NeO+KX+GM/F9x npMhMjphvz1cggLIl1c3TpXOAtygR1ScmHapKg7Kv/rzWajCHWAwnU9oY/DxJa/jxKBdjHPjMYU GAdbiTPav5MEwkFSrSn0KoGaaV5ksi9XpJA+8tv7ys6CKq3kBG6X8+AkSntMyUQCEe3MdnhJxe/ Km8n1ukCrqt+R1wijKcXsyydNPL9QAJKy5HJ3cbLi/pnZUCnaO/u/OtFjril8bNRR4LEwCGhyrc i0RV764XBJgDLNeNGTj9inPaT/5OpXcTfufSxmVPvD8GwbwnSJ7Rx8MF1apViHKPfWzUtKAoJLz vIpGz8CgW6UFFjEd7RuV/9dbARWJNYfGByzwj+f1LnC5HpkVMKrmP4ADs9ZZ5ZOmi/DYyzDzXcZ pnEUfQnZKJtjwx4tryCPaDOUkqWOU7Nn3MaJVxMaQ4+9YCie/UWDDQQdSGuL/NN/yey6tdKNdvJ t49yAZvD+dCDFpZQZY1UO+qkGvYvL0Ta/e3ccka6tTfkBsJUI5ElW+KwGg06UVS9nU8D/cqwq4g XSR/KywZ5cGxW9A== X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 X-Patchwork-Delegate: bpf@iogearbox.net From: Geliang Tang It's necessary to traverse all subflows on the conn_list of an MPTCP socket and then call kfunc to modify the fields of each subflow. In kernel space, mptcp_for_each_subflow() helper is used for this: mptcp_for_each_subflow(msk, subflow) kfunc(subflow); But in the MPTCP BPF program, this has not yet been implemented. As Martin suggested recently, this conn_list walking + modify-by-kfunc usage fits the bpf_iter use case. So this patch adds a new bpf_iter type named "mptcp_subflow" to do this and implements its helpers bpf_iter_mptcp_subflow_new()/_next()/ _destroy(). And register these bpf_iter mptcp_subflow into mptcp common kfunc set. Then bpf_for_each() for mptcp_subflow can be used in BPF program like this: bpf_for_each(mptcp_subflow, subflow, msk) kfunc(subflow); Suggested-by: Martin KaFai Lau Signed-off-by: Geliang Tang Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) --- Notes: A few versions of this single patch have been previously posted to the BPF mailing list by Geliang, before continuing to the MPTCP mailing list only, with other patches of this series. The version of the whole series has been reset to 1, but here is the ChangeLog for this patch here: - v2: remove msk->pm.lock in _new() and _destroy() (Martin) drop DEFINE_BPF_ITER_FUNC, change opaque[3] to opaque[2] (Andrii) - v3: drop bpf_iter__mptcp_subflow - v4: if msk is NULL, initialize kit->msk to NULL in _new() and check it in _next() (Andrii) - v5: use list_is_last() instead of list_entry_is_head() add KF_ITER_NEW/NEXT/DESTROY flags add msk_owned_by_me in _new() - v6: add KF_TRUSTED_ARGS flag (Andrii, Martin) --- net/mptcp/bpf.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index 6f96a5927fd371f8ea92cbf96c875edef9272b98..d107c2865e97e6ccffb9e0720dfbbd232b63a3b8 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -29,6 +29,15 @@ static const struct btf_kfunc_id_set bpf_mptcp_fmodret_set = { .set = &bpf_mptcp_fmodret_ids, }; +struct bpf_iter_mptcp_subflow { + __u64 __opaque[2]; +} __aligned(8); + +struct bpf_iter_mptcp_subflow_kern { + struct mptcp_sock *msk; + struct list_head *pos; +} __aligned(8); + __bpf_kfunc_start_defs(); __bpf_kfunc static struct mptcp_sock *bpf_mptcp_sk(struct sock *sk) @@ -48,12 +57,48 @@ bpf_mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow) return mptcp_subflow_tcp_sock(subflow); } +__bpf_kfunc static int +bpf_iter_mptcp_subflow_new(struct bpf_iter_mptcp_subflow *it, + struct mptcp_sock *msk) +{ + struct bpf_iter_mptcp_subflow_kern *kit = (void *)it; + + kit->msk = msk; + if (!msk) + return -EINVAL; + + msk_owned_by_me(msk); + + kit->pos = &msk->conn_list; + return 0; +} + +__bpf_kfunc static struct mptcp_subflow_context * +bpf_iter_mptcp_subflow_next(struct bpf_iter_mptcp_subflow *it) +{ + struct bpf_iter_mptcp_subflow_kern *kit = (void *)it; + + if (!kit->msk || list_is_last(kit->pos, &kit->msk->conn_list)) + return NULL; + + kit->pos = kit->pos->next; + return list_entry(kit->pos, struct mptcp_subflow_context, node); +} + +__bpf_kfunc static void +bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_subflow *it) +{ +} + __bpf_kfunc_end_defs(); BTF_KFUNCS_START(bpf_mptcp_common_kfunc_ids) BTF_ID_FLAGS(func, bpf_mptcp_sk) BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx) BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock) +BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_new, KF_ITER_NEW | KF_TRUSTED_ARGS) +BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_next, KF_ITER_NEXT | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_destroy, KF_ITER_DESTROY) BTF_KFUNCS_END(bpf_mptcp_common_kfunc_ids) static const struct btf_kfunc_id_set bpf_mptcp_common_kfunc_set = {