From patchwork Fri Oct 18 16:00:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geliang Tang X-Patchwork-Id: 13842003 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 A7BAD1F4266 for ; Fri, 18 Oct 2024 16:00:38 +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=1729267238; cv=none; b=HD7dnKVzQ3bGWheA9a8IToOu9KFAAl7+XbvQnyys4VjuiyeQyap4URrsomYF3Wylv5DmmJIFXKsHQzcG8u1K8EdVIcPac8GmMacrYmcpXJMm8L7gkPqForJvj+ZtKcQGRBJbtRSsmNrWgJNUuuAFPLSY+FGGFBg4C0KVE1z2ftM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729267238; c=relaxed/simple; bh=/UWS8+VBjYFrqdOw4KZJINWR8TNN98J/VAUIMhPLzWk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eUZMm/3NGUEOo9mMCYe/OfSr9VLWf0c9qoXbgsK9oXb4psZqBJdcau2Ww9pCkZID/rogHAaNvAKhep+z0tlda5jcrcMS2L9bIrjDj2PrbWldAiWl+ZapHUBLTnPt0fUDRTMK3E5M47IU25e6A92d/NStgzaaXlcATh31QnPoG2I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=syOxTWs0; 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="syOxTWs0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05133C4CEC3; Fri, 18 Oct 2024 16:00:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729267238; bh=/UWS8+VBjYFrqdOw4KZJINWR8TNN98J/VAUIMhPLzWk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=syOxTWs0oGN5w1dAaZqkN0QmXXXWn1wrB+sUIB/UeQWFTWcWSGok+ECQOX/G7fIaE DtmCMYOnl+TdSMLW0Tb3eN45jlwhHJTRh7GCcrTRqVxVw1Ln+0NgtuNK5iu0sahNW7 Zvfpq3NzN+WntEzjUd/K1adIczeU/ZirMHXZZoxLbdf+7c+BxwtW+ZyEWvZmkrFAVt LwSU0+Ous51SDMHp2iNoQhqtdV0hbbhNgr9/qQqsXChFzw5LNKFTiZuhelyegw+PeV JGnlwFh+REqkuqOf2ATgfe7xUlHwIt4p3roVI0dUSQZTOzxnmFKO2W2WTRD/lgIB8b 4pJ+uujq0EgXw== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v12 2/8] bpf: Add mptcp_subflow bpf_iter Date: Sat, 19 Oct 2024 00:00:22 +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 efab2e6e28ef..65fa84d1e745 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -205,9 +205,16 @@ 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_sock *bpf_mptcp_sk(struct sock *sk) { @@ -226,6 +233,37 @@ 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) { @@ -239,12 +277,15 @@ __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_sk) 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 = {