From patchwork Wed Oct 16 07:33:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geliang Tang X-Patchwork-Id: 13837826 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 A2AA4BA45 for ; Wed, 16 Oct 2024 07:33:27 +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=1729064007; cv=none; b=i6mReFrSD5pzxaQr5fJlht8NrKAkxhEPqgXYzgUH+/RciO966dxtDPEE3COU4KiTISjRs7yxsdPKSWcWYfmwb1QqogIk209EeoNefQdzJmLkX3Ewn52d6EZ9PXBAEntgTEO0ii+3o7NM2myEfeQGe0UkD0uDXbvIRpVq8XgbpsI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729064007; c=relaxed/simple; bh=RRSb1zeoSM+dyicu1bBIlFG1bgoV3aLuhu2RfPPacEE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u/M1ddpaLf2qui+MOOU5KEfr6VUKM+v61O8y3VdECbL+pr9DnHUlOHRuXa68CCw1tIMCzbYOLzNNdy1FcZDO3z+fectjNOTObOTN5TAUTMWyy2hZn0pini35aCleOv9qi/7Lh94bisUXbiXTDABxv2/1RC6Wp+MMJ4bJ8okcRm0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NY7G1nw8; 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="NY7G1nw8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AC97C4CECF; Wed, 16 Oct 2024 07:33:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729064007; bh=RRSb1zeoSM+dyicu1bBIlFG1bgoV3aLuhu2RfPPacEE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NY7G1nw8eMnzSevMdzyY2KxcvLeBfg2SB8DbvHKjR6jckdKpFnZXja4qmDuP7gXCz pNKVdQuAaF4Xi2P4Sr4dOWAmkG1r/nJyvFhFl/MZCECy3++5qj+a38zekwc4GJN87G wjgww0cbPX2W1heatMk3Ra11L7cCnR7yduXOA2vHpjv6TcnFUBySkUaWoWFASlJ0ej NqLALkI6DUwR5/sAAJwnZ3BHLXJKfZpTvInLFgDM1T18HCoIjr6bHuRFb/45bzBkw6 TLZbXotSW6765Sk1blx3pqjCcgbAfu8PAoOsvfn6PzkuA6E3mmETrkay5oo7Fck2Rv Rqx5SvRvddwtg== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v10 2/9] bpf: Add mptcp_subflow bpf_iter Date: Wed, 16 Oct 2024 15:33:09 +0800 Message-ID: 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 22d2d4d09be7..405907b79d4d 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -201,9 +201,16 @@ 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 static struct mptcp_subflow_context * bpf_mptcp_subflow_ctx(const struct sock *sk) @@ -217,6 +224,37 @@ bpf_mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow) return mptcp_subflow_tcp_sock(subflow); } +__bpf_kfunc static 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 static 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 static 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) { @@ -230,11 +268,14 @@ __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, bpf_mptcp_subflow_ctx) BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock) +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 = {