From nobody Sat Dec 21 17:18:20 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 03027282F7 for ; Wed, 11 Sep 2024 03:03:07 +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=1726023788; cv=none; b=OyFzJB36q4eV++O84L8n4vCbrEfduCfdMZ9DcK/MVJ+uq+lQwyD92VZtRKPzsWs8Y8Y+v3U/V4jVEqw4yxzJr8743I8uYXs+RPK1rYVbtZIPy0u8873tKU0ZFhNR61cI3hHHUysMTRUNwBpg3fjwo7gsd03QBsDuqYk3tT+DgGY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726023788; c=relaxed/simple; bh=KIS4caqoNjH0E4BAyvWDRRI/oxQI0k/8jBq6pMbjszw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Jn2WkxJzuX0Z2d+foM6/sHST6mKk1fD215/v/8W46mOUdBsptmAyJGyWsIZV2UIv7oZkqkHkuojGX9ntoK3qngLGet8E2gLsg6WtMNutbLJLhh5KLTnIu7yepS1e/l9rlYMtOG5k4jwaPNGhZy83YoOh2ma4LIdLiMmY01wUvH4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A+Zsv5WD; 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="A+Zsv5WD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F3697C4CEC3; Wed, 11 Sep 2024 03:03:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726023787; bh=KIS4caqoNjH0E4BAyvWDRRI/oxQI0k/8jBq6pMbjszw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A+Zsv5WDF5JrGUutoZ2ryC13EKT5oEmO3vclLyuIXsFVOG2xLD4udtTFEIYBfSAXn lozSkrUAbq/3gyvo5u41lK8BZRXe37K5j2FG1uSVdgmT88mw/Jr0gEVqrtuenr/qtZ JEINFilT6+W2LLxDJG7NohAA7BggYutZMl1HkkIh5CTvKZWa+zHXkZsK4hGVr0SNnV FkwHj2/ffIWbkQo/I2z6CRDk7hA+eXk7fe7uvFP+OG1kSxkbQBuWa2Jr6330b43fZK YsLc2coriE7U++NQ2NUWIx5NrKkKBOIGbF9ggbGf6SFuDCJJJ5qdlb+pkxkP/AEhrc OS6iiMrdPr3Dw== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang , Martin KaFai Lau Subject: [PATCH mptcp-next v4 1/5] bpf: Add mptcp_subflow bpf_iter Date: Wed, 11 Sep 2024 11:02:55 +0800 Message-ID: <34159d5cb4df8168bc7613ef651b714ba2762d80.1726023577.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.43.0 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 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(). Since these bpf_iter mptcp_subflow helpers are invoked in its selftest in a ftrace hook for mptcp_sched_get_send(), it's necessary to register them into a BPF_PROG_TYPE_TRACING type kfunc set together with other two used kfuncs mptcp_subflow_active() and mptcp_subflow_set_scheduled(). Then bpf_for_each() for mptcp_subflow can be used in BPF program like this: bpf_rcu_read_lock(); bpf_for_each(mptcp_subflow, subflow, msk) kfunc(subflow); bpf_rcu_read_unlock(); Suggested-by: Martin KaFai Lau Signed-off-by: Geliang Tang --- net/mptcp/bpf.c | 54 ++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 49 insertions(+), 5 deletions(-) diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index 6414824402e6..0b7a0c2634c4 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -201,9 +201,48 @@ static const struct btf_kfunc_id_set bpf_mptcp_fmodret= _set =3D { .set =3D &bpf_mptcp_fmodret_ids, }; =20 -__diag_push(); -__diag_ignore_all("-Wmissing-prototypes", - "kfuncs which will be used in BPF programs"); +struct bpf_iter_mptcp_subflow { + __u64 __opaque[2]; +} __attribute__((aligned(8))); + +struct bpf_iter_mptcp_subflow_kern { + struct mptcp_sock *msk; + struct list_head *pos; +} __attribute__((aligned(8))); + +__bpf_kfunc_start_defs(); + +__bpf_kfunc int bpf_iter_mptcp_subflow_new(struct bpf_iter_mptcp_subflow *= it, + struct mptcp_sock *msk) +{ + struct bpf_iter_mptcp_subflow_kern *kit =3D (void *)it; + + if (!msk) + return -EINVAL; + + kit->msk =3D msk; + kit->pos =3D &msk->conn_list; + return 0; +} + +__bpf_kfunc struct mptcp_subflow_context * +bpf_iter_mptcp_subflow_next(struct bpf_iter_mptcp_subflow *it) +{ + struct bpf_iter_mptcp_subflow_kern *kit =3D (void *)it; + struct mptcp_subflow_context *subflow; + struct mptcp_sock *msk =3D kit->msk; + + subflow =3D list_entry((kit->pos)->next, struct mptcp_subflow_context, no= de); + if (!msk || list_entry_is_head(subflow, &msk->conn_list, node)) + return NULL; + + kit->pos =3D &subflow->node; + return subflow; +} + +__bpf_kfunc void bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_subf= low *it) +{ +} =20 __bpf_kfunc struct mptcp_subflow_context * bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned= int pos) @@ -218,12 +257,15 @@ __bpf_kfunc bool bpf_mptcp_subflow_queues_empty(struc= t sock *sk) return tcp_rtx_queue_empty(sk); } =20 -__diag_pop(); +__bpf_kfunc_end_defs(); =20 BTF_KFUNCS_START(bpf_mptcp_sched_kfunc_ids) +BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_new) +BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_next) +BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_destroy) +BTF_ID_FLAGS(func, mptcp_subflow_active) BTF_ID_FLAGS(func, mptcp_subflow_set_scheduled) BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx_by_pos) -BTF_ID_FLAGS(func, mptcp_subflow_active) BTF_ID_FLAGS(func, mptcp_set_timeout) BTF_ID_FLAGS(func, mptcp_wnd_end) BTF_ID_FLAGS(func, tcp_stream_memory_free) @@ -241,6 +283,8 @@ static int __init bpf_mptcp_kfunc_init(void) int ret; =20 ret =3D register_btf_fmodret_id_set(&bpf_mptcp_fmodret_set); + ret =3D ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, + &bpf_mptcp_sched_kfunc_set); ret =3D ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &bpf_mptcp_sched_kfunc_set); #ifdef CONFIG_BPF_JIT --=20 2.43.0