From nobody Sun Dec 22 07:10:10 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 708B3148FF6 for ; Fri, 4 Oct 2024 12:51:05 +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=1728046265; cv=none; b=TajcwEZ4643WbVgke6x2/ExBINv0Jiz1+Q7BJa7hTOqWWLD2razf5/u4+LhyH5kcQOtHffpcayu2xfFgZ79GBe68zF8TXFHYIhf7NG3dPh/DwVk1XDXXrB4QPZFzpxH5JHPo6U+bSP8wxDS8srFGldrjPd6wG6c/+3wd5vS2e9Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728046265; c=relaxed/simple; bh=O1htgLgO+7Td8JamHEr01Fptmb+sf0FY9hvLQG6kjOM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AB+u+BQ97bTSX4vPkNtdqrDIFXaLCd0vzj9EPnF2XqMJkHFL4XW4Rld4lKnRChS7dGhkUJkomervZ2SnNrZ5BiWkC2dpwyEn5bXRUu/712AWCzuQurju+H02pMrEtk0kdF3OQviCofqpE1cGi5Qay3dKD6gPqPHsK6vsJQPpwhw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=h3aHGd31; 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="h3aHGd31" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D70BEC4DE1E; Fri, 4 Oct 2024 12:51:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728046265; bh=O1htgLgO+7Td8JamHEr01Fptmb+sf0FY9hvLQG6kjOM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h3aHGd313DuwjByV18TEfIvArHGclaY5gVxSD1CNw+OIVj+u3L7hkWkUHocfEq398 jyIdunmFiXFTBFQBE6exggN8jf+bPh4PfbWMrF0EJ0xpJiPCrvuaxzWp6XuT8/i+KV oAVav1WrBb31nuW1wxp1CkDybKhANTrpVGHa/1uZ3EqSBX47HMG+xP5UJcFGHhNYvU PyKENS0vXPEz+Pi5jQjqnAShuRdC61k8INpoNOinjNfje3vfb9/qnrk4lUiR0DZW+C DvjzLVVk8FLHshG+uMPVuXEFWSEJr9PGUk5/hoGfMVYsZ3M2asxwnQdLR0vXz8qthh Z9B/7+QDG/GFA== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v8 2/7] bpf: Add mptcp_subflow bpf_iter Date: Fri, 4 Oct 2024 20:50:48 +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 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(). 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 c8bc18dff85d..49df9e5d5667 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 =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(); =20 __bpf_kfunc struct mptcp_sock *bpf_mptcp_sk(struct sock *sk) { @@ -222,6 +229,37 @@ bpf_mptcp_subflow_tcp_sock(const struct mptcp_subflow_= context *subflow) return mptcp_subflow_tcp_sock(subflow); } =20 +__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; + + kit->msk =3D msk; + if (!msk) + return -EINVAL; + + msk_owned_by_me(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; + + if (!kit->msk || list_is_last(kit->pos, &kit->msk->conn_list)) + return NULL; + + kit->pos =3D 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_subf= low *it) +{ +} + __bpf_kfunc struct mptcp_subflow_context * bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned= int pos) { @@ -235,7 +273,7 @@ __bpf_kfunc bool bpf_mptcp_subflow_queues_empty(struct = sock *sk) return tcp_rtx_queue_empty(sk); } =20 -__diag_pop(); +__bpf_kfunc_end_defs(); =20 BTF_KFUNCS_START(bpf_mptcp_common_kfunc_ids) BTF_ID_FLAGS(func, bpf_mptcp_sk) @@ -243,6 +281,9 @@ BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx) BTF_ID_FLAGS(func, bpf_mptcp_subflow_tcp_sock) BTF_ID_FLAGS(func, mptcp_subflow_set_scheduled) BTF_ID_FLAGS(func, mptcp_subflow_active) +BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_new, KF_ITER_NEW | KF_TRUSTED_AR= GS) +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) =20 static const struct btf_kfunc_id_set bpf_mptcp_common_kfunc_set =3D { --=20 2.43.0