From patchwork Tue Sep 24 09:09:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geliang Tang X-Patchwork-Id: 13810557 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 C4E0680C13 for ; Tue, 24 Sep 2024 09:10:05 +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=1727169005; cv=none; b=SMOtxPXKMrMGyCYcZ+35HaARqREGBa3DVM/GRcQ5ocS8hl1aEUaDMl2KRPYq5UqnVxinJwIfz518zJVRQCx3/q+ygie0+Gc6ZLU3KFTaM3r8lWCW3zTOO27ROE6p8A/KusZ37AgNL+AWF8fxIikYRxMSQP7htfpuzx6gnBO7Ib4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727169005; c=relaxed/simple; bh=Ih0h8HtYHUSPF1Gh6spc0a6lNKdgk7FaVAHKTnyPUjM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=U0XFUHUDxRRvV697JP0dfPQYqlwkWJR+TWZqVC+kdP6ng6YM1UnCS34u7Rdx4pNexnuPHdOQvzx4xU46iBbi15wqqhd6fTWqpv6crGZ87TCzNQABMEMsEGqRKFTQ8Bvp3ooD5Rk7sGzSynMsocC4axkl+21I4EiaUCzqDD3+Oyo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BoqFNSph; 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="BoqFNSph" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 772F7C4CEC4; Tue, 24 Sep 2024 09:10:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727169005; bh=Ih0h8HtYHUSPF1Gh6spc0a6lNKdgk7FaVAHKTnyPUjM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BoqFNSphsRF8/YBBvVp+0cimzYp1RFY872nSxgOtq5W0qvdKesFk3xdJYBvNY1Y66 Nbyi740Cj5Hkyy1MX2SVE75GvhRnqz5MKtiL3IWSxzacl19Q+LOsPkdbTy6pHTHMP8 XzVb3EciECWV1QvNRQpDqNIa9A+csjAfmpDmA73EPa3CkK5WZrYnYuhIVCKbythHQz 8l/+zVKCTA/mdZom5vm/5+rX+7Jbfz6vdyYiduNjHNC3YLKCDb6s8619IA/eX0lYXC buvpcaCEnA4x3nvNxVbQ77mHTlq1+ayfuBn0AMiXucbO692R38jMZlq8EyKtERZTLO zua4j2nWWlDpw== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v6 02/10] bpf: Add mptcp_subflow bpf_iter Date: Tue, 24 Sep 2024 17:09:46 +0800 Message-ID: <9139af7024b3de3389bf8d2ec4d5da91309940b3.1727168628.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 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); 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) "Suggested-by: Martin KaFai Lau " Signed-off-by: Geliang Tang --- net/mptcp/bpf.c | 49 +++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 45 insertions(+), 4 deletions(-) diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index 959d1d6af036..3e13bf126e0e 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -201,15 +201,53 @@ 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 struct mptcp_sock *bpf_mptcp_sk(struct sock *sk) { return mptcp_sk(sk); } +__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; + + kit->msk = msk; + if (!msk) + return -EINVAL; + + msk_owned_by_me(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; + + 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 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) { @@ -223,11 +261,14 @@ __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_common_kfunc_ids) BTF_ID_FLAGS(func, mptcp_subflow_active) BTF_ID_FLAGS(func, bpf_mptcp_sk) +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 = {