From nobody Mon Feb 9 23:03:07 2026 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 B4F30535CF for ; Mon, 8 Apr 2024 10:27:01 +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=1712572021; cv=none; b=GrT6567vXA5+nQupCEW6s9JzFQF/89HB9PVzBNpAvCR9IVNUi2alXX2XbZrb3zovRtB9OEICbkepSALYck1SCsCC+ErtC302boCsMhCi4rHlsdmHSkdXTycmjoPEHvr3mE3E2dxVo97rv1Nlm2TBBzp9GiaFdKGij7ufoAYx/qU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712572021; c=relaxed/simple; bh=/gp8CV9+6krH/otjOe76Jy8R8dlIiwlHiNzqUY/kYzY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=OqsSnRbz+6Wzu8yNOf5uJaDfcY0Z5ee/r1e0eGTIfwExm0FdUKRi5x/axVk2sd8b3/+0vIXTVwW9acatxxgt4aXfzbSDFNh0JqdhjyBragTDxbcPdsq6FvdtklHneqhyY6n/56tb63dQtnEnAQH/ogpdyr9gIQU7rj3Clbzm4ZI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j9DFY5H6; 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="j9DFY5H6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 010F7C43394; Mon, 8 Apr 2024 10:26:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712572021; bh=/gp8CV9+6krH/otjOe76Jy8R8dlIiwlHiNzqUY/kYzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j9DFY5H6gEC/IbmA0LczqU8O3Y1ttAfFwg04ekgeDR2sAxThgoTyFUbPOkyZTrDap mXMCn6IzZJUHCHuQ8ilhtGpp27rJPEoQOY/sSORJDziOFGlUbaR+PYgh4ktBa82g2c 04Y4tX5uKE1e05/SMEwvdlv0Twt930Hq0exPtWCcty6scD9J0YXvhLYsoNuy0FXIux s3CvE6e7Qdk0mkJJGTZDyd1Ekif98rnqNKWPV3fWTlrh1DHzh4dv58kIE8DakuDMhN 5VcYmWEYmyPCrwOeyeN4SxdXCav3pDP7EP/5TmFy6tT/dygTH9881rpYTHwMbfyqf5 K3YRZil993f7Q== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v7 1/5] selftests/bpf: Add mptcp subflow example Date: Mon, 8 Apr 2024 18:26:48 +0800 Message-Id: X-Mailer: git-send-email 2.40.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang Move Nicolas's patch into bpf selftests directory. This example added a test that was adding a different mark (SO_MARK) on each subflow, and changing the TCP CC only on the first subflow. This example shows how it is possible to: Identify the parent msk of an MPTCP subflow. Put different sockopt for each subflow of a same MPTCP connection. Here especially, we implemented two different behaviours: A socket mark (SOL_SOCKET SO_MARK) is put on each subflow of a same MPTCP connection. The order of creation of the current subflow defines its mark. The TCP CC algorithm of the very first subflow of an MPTCP connection is set to "reno". Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/76 Signed-off-by: Geliang Tang --- .../selftests/bpf/progs/mptcp_subflow.c | 71 +++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/mptcp_subflow.c diff --git a/tools/testing/selftests/bpf/progs/mptcp_subflow.c b/tools/test= ing/selftests/bpf/progs/mptcp_subflow.c new file mode 100644 index 000000000000..9bdafc0930f1 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/mptcp_subflow.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020, Tessares SA. */ +/* Copyright (c) 2024, Kylin Software */ +/* Author: Nicolas Rybowski */ + +#include // SOL_SOCKET, SO_MARK, ... +#include // TCP_CONGESTION +#include +#include +#include "bpf_tcp_helpers.h" + +char _license[] SEC("license") =3D "GPL"; + +#ifndef SOL_TCP +#define SOL_TCP 6 +#endif + +#ifndef TCP_CA_NAME_MAX +#define TCP_CA_NAME_MAX 16 +#endif + +char cc[TCP_CA_NAME_MAX] =3D "reno"; + +/* Associate a subflow counter to each token */ +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u32)); + __uint(max_entries, 100); +} mptcp_sf SEC(".maps"); + +SEC("sockops") +int mptcp_subflow(struct bpf_sock_ops *skops) +{ + __u32 init =3D 1, key, mark, *cnt; + struct mptcp_sock *msk; + struct bpf_sock *sk; + int err; + + if (skops->op !=3D BPF_SOCK_OPS_TCP_CONNECT_CB) + return 1; + + sk =3D skops->sk; + if (!sk) + return 1; + + msk =3D bpf_skc_to_mptcp_sock(sk); + if (!msk) + return 1; + + key =3D msk->token; + cnt =3D bpf_map_lookup_elem(&mptcp_sf, &key); + if (cnt) { + /* A new subflow is added to an existing MPTCP connection */ + __sync_fetch_and_add(cnt, 1); + mark =3D *cnt; + } else { + /* A new MPTCP connection is just initiated and this is its primary subf= low */ + bpf_map_update_elem(&mptcp_sf, &key, &init, BPF_ANY); + mark =3D init; + } + + /* Set the mark of the subflow's socket based on appearance order */ + err =3D bpf_setsockopt(skops, SOL_SOCKET, SO_MARK, &mark, sizeof(mark)); + if (err < 0) + return 1; + if (mark =3D=3D 1) + err =3D bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION, cc, TCP_CA_NAME_M= AX); + + return 1; +} --=20 2.40.1