From patchwork Tue Sep 10 05:37:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geliang Tang X-Patchwork-Id: 13797967 X-Patchwork-Delegate: kuba@kernel.org 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 3A3B5167265; Tue, 10 Sep 2024 05:37:36 +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=1725946657; cv=none; b=GoPHrrXfct1+pz9tuvqCmjSwatrzc241h6j6VHo3+4M8wUhDhWcfXgFE/ytgQMm0MnQHqN4+w27UFlq9git9k7ebDulPpIZJ/z6nnm4XNRALdcuduxuoTYDRCIapk4VJL0OXTqn9jUK9RCZG1REaAVN8Wpo4lyM7BQ2WbiMRVVs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725946657; c=relaxed/simple; bh=D5TYavM29ltridmAsCsO8PzJ/nzNH0IhkjhLoU87B1Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=B40pJV+dKKc+ecUBlmNYc8KDKwjjzFS17I89j8iBePOkXSwU9zIfO0LtAKObVIhSBrFXPhNlrNSueriGny7i1hmeS+Lv63+vf39b2dFYgPUrmhyCCRUxsstpz2qjZtexSzhNlWSwF0tlJbSVbPuFMc1txbV/rsMD/ABiAs8/7sA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Jb/M3JU0; 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="Jb/M3JU0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06FE0C4CEC3; Tue, 10 Sep 2024 05:37:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725946656; bh=D5TYavM29ltridmAsCsO8PzJ/nzNH0IhkjhLoU87B1Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jb/M3JU04RjAlCYKSqVHue2EQuRIqTq2kyBE1AFwZKgOXv+NOx8MvUXdIMkIVmZeF FkRMc/6q8eijqY+KID39U+RlEWUzJRpRX3iSa0gBS1mGvVBD6iQ7tGigEB1FD/XytO wPWOPbOxyIPSlpGFgj8/X2XK6Mx4L7QDJ+pqiUkb7VyszzhJH60ndn5dXtOeMvgHzS 7dzt7wiP0BWE5/eI2tlq58zRNREAJyWqURpdWBwOJYmfAv3WhfIjN9g5MoqCy6sO3L U31j2Xn4tn45rVGwz2YWJED1FEMJmhrX5f6aNPAdulgysopZMz9IcYQJBYJ/Pji1i0 q7CJ8VoPMbqXw== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang , bpf , Martin KaFai Lau Subject: [PATCH mptcp-next v3 1/5] bpf: Add mptcp_subflow bpf_iter Date: Tue, 10 Sep 2024 13:37:23 +0800 Message-ID: <026dce3d6903ad189e4b0518a64b60c910e660c0.1725946276.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org 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(). 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 | 47 +++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 43 insertions(+), 4 deletions(-) diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index 6414824402e6..350672e24a3d 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 = { .set = &bpf_mptcp_fmodret_ids, }; -__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 = (void *)it; + + if (!msk) + return -EINVAL; + + kit->msk = msk; + kit->pos = &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 = (void *)it; + struct mptcp_subflow_context *subflow; + struct mptcp_sock *msk = kit->msk; + + subflow = list_entry((kit->pos)->next, struct mptcp_subflow_context, node); + if (!msk || list_entry_is_head(subflow, &msk->conn_list, node)) + return NULL; + + kit->pos = &subflow->node; + return subflow; +} + +__bpf_kfunc void bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_subflow *it) +{ +} __bpf_kfunc struct mptcp_subflow_context * bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos) @@ -218,7 +257,7 @@ __bpf_kfunc bool bpf_mptcp_subflow_queues_empty(struct sock *sk) return tcp_rtx_queue_empty(sk); } -__diag_pop(); +__bpf_kfunc_end_defs(); BTF_KFUNCS_START(bpf_mptcp_sched_kfunc_ids) BTF_ID_FLAGS(func, mptcp_subflow_set_scheduled)