From nobody Tue Feb 10 03:17:30 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 68F7E52F86 for ; Thu, 28 Mar 2024 08:05:25 +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=1711613125; cv=none; b=hz9D7uu54vRm6rnVkzrV6I6SMnp84hLVPfXVg0tlbCPmAb8JFZRvtdNxOyWBMoRBQ0qFHKdZuafY3fXkoLkWzaB+Pidoi1ugJl90/HIKcyB/nRHpKOi5lQPnkqZso5461nQ43cLh/4HiCO3MdsoTslmSmdEmwIa3Q3i3UxnwD0E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711613125; c=relaxed/simple; bh=S0+kctrHQgktXLmfRi63oj2s6hctBrghW6AsPgATIqs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=BpNMrs2/ma3K5MWr3lUF3sJ+38phy5C6gBEZQRx/xBYAYwgGur1WJomISeCXuW0MVAHy+z1vZ24kebT8qzQF2DF2ZLobvBcTGPvFQ96iL0WMfwEoVVypdLYnztbIz+kTfzhZhTqGmlq4mEe4G7M1C36ojtnYwvFgGrDl44vqK4Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Jjul46tf; 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="Jjul46tf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27EBBC433C7; Thu, 28 Mar 2024 08:05:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711613125; bh=S0+kctrHQgktXLmfRi63oj2s6hctBrghW6AsPgATIqs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jjul46tf/9Gg3qldFBOuD5bxFWuWrUUYVxFBqeyGK2bTE4y2/Qbnko3REYQlZyfNY oEaQPvoACau+FIChonR7OUW2NQ6YgOCgGwhVx6+KWYW9HtJxLvmygpMIJBltyKiC0D qZvl8dQ+i11o8Q6Msztm4KnU9kY+Re8JzhlCmoIqE68vDwrci1lmuy5WHLd8SZjwX/ dzcznksbaHvyFixg4faihlqhUpDeSVkVJC4GanIsMH8LHuFK0lLXr6QDrdl1qIe1hD YFkMzq02HMEMdqwKKLQDi1w7WMdz+XQ9mIkeJb0UWmJSE4/cMg+jjbazVDKf6+1dED nN2MraBGW8vbQ== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v5 06/14] selftests/bpf: Add mptcp subflow example Date: Thu, 28 Mar 2024 16:04:53 +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 | 73 +++++++++++++++++++ 1 file changed, 73 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..9553099ffd5f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/mptcp_subflow.c @@ -0,0 +1,73 @@ +// 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 + * subflow + */ + bpf_map_update_elem(&mptcp_sf, &key, &init, BPF_ANY); + mark =3D init; + } + + /* Set the mark of the subflow's socket to its apparition 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