From patchwork Thu Feb 23 01:12:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kui-Feng Lee X-Patchwork-Id: 13149753 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63163C61DA4 for ; Thu, 23 Feb 2023 01:13:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232869AbjBWBNC (ORCPT ); Wed, 22 Feb 2023 20:13:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232645AbjBWBNB (ORCPT ); Wed, 22 Feb 2023 20:13:01 -0500 Received: from mx0b-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76199DB for ; Wed, 22 Feb 2023 17:13:00 -0800 (PST) Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 31MNCTXF005575 for ; Wed, 22 Feb 2023 17:12:59 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=meta.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=s2048-2021-q4; bh=yrIycV+V2vWw4n9Nr+I18UnBoEkn0Vy76vFaqSEY3ck=; b=dmAmD8xWYo3nRZYCXqT1a9hdUla7FyDO/o0/vwe4afrQdrfL4ebRKN6b6f7sWZ5gJWX0 kNtvjunve0tmtFt+MkQEYsbpvfqmgw3Bi+lCvHx+pHwdpjoEpuuJ0TRUki7SB1D2eGw+ ORrAVPHRlapy/7GhJJfYqI7Ok+KEOa1RJoS2SE5iVlWgSAoHt4Nkdy15P497cTs2De0Y jOW4qE1sCFGCZxZF3x5AhSMsqXQijMMC+jb4iiMdHyCuS1F0RRxl2Vyzx6WHEGVOqLcU jg9ZrjZAdWdeYX/8EvR+DqfFu9s0yDb4RnnzFYYJhiqQwe2qYA8eKzi6Jne9XWmpdfIh nw== Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3nw7um0h10-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 22 Feb 2023 17:12:59 -0800 Received: from twshared1992.22.frc3.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:11d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.17; Wed, 22 Feb 2023 17:12:58 -0800 Received: by devbig931.frc1.facebook.com (Postfix, from userid 460691) id A90995BD8CC0; Wed, 22 Feb 2023 17:12:40 -0800 (PST) From: Kui-Feng Lee To: , , , , , , CC: Kui-Feng Lee Subject: [PATCH bpf-next v2 2/6] net: Update an existing TCP congestion control algorithm. Date: Wed, 22 Feb 2023 17:12:34 -0800 Message-ID: <20230223011238.12313-3-kuifeng@meta.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230223011238.12313-1-kuifeng@meta.com> References: <20230223011238.12313-1-kuifeng@meta.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: lOA6qxppvvVafnABPPMoh_2TDD4ItwrK X-Proofpoint-ORIG-GUID: lOA6qxppvvVafnABPPMoh_2TDD4ItwrK X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.170.22 definitions=2023-02-22_12,2023-02-22_02,2023-02-09_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This feature lets you immediately transition to another congestion control algorithm or implementation with the same name. Once a name is updated, new connections will apply this new algorithm. Signed-off-by: Kui-Feng Lee --- include/linux/bpf.h | 1 + include/net/tcp.h | 2 ++ net/bpf/bpf_dummy_struct_ops.c | 6 ++++ net/ipv4/bpf_tcp_ca.c | 8 +++-- net/ipv4/tcp_cong.c | 58 ++++++++++++++++++++++++++++++---- 5 files changed, 66 insertions(+), 9 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 9d6fd874e5ee..7508ca89e814 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1451,6 +1451,7 @@ struct bpf_struct_ops { void *kdata, const void *udata); int (*reg)(void *kdata); void (*unreg)(void *kdata); + int (*update)(void *kdata, void *old_kdata); const struct btf_type *type; const struct btf_type *value_type; const char *name; diff --git a/include/net/tcp.h b/include/net/tcp.h index db9f828e9d1e..239cc0e2639c 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1117,6 +1117,8 @@ struct tcp_congestion_ops { int tcp_register_congestion_control(struct tcp_congestion_ops *type); void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); +int tcp_update_congestion_control(struct tcp_congestion_ops *type, + struct tcp_congestion_ops *old_type); void tcp_assign_congestion_control(struct sock *sk); void tcp_init_congestion_control(struct sock *sk); diff --git a/net/bpf/bpf_dummy_struct_ops.c b/net/bpf/bpf_dummy_struct_ops.c index ff4f89a2b02a..158f14e240d0 100644 --- a/net/bpf/bpf_dummy_struct_ops.c +++ b/net/bpf/bpf_dummy_struct_ops.c @@ -222,12 +222,18 @@ static void bpf_dummy_unreg(void *kdata) { } +static int bpf_dummy_update(void *kdata, void *old_kdata) +{ + return -EOPNOTSUPP; +} + struct bpf_struct_ops bpf_bpf_dummy_ops = { .verifier_ops = &bpf_dummy_verifier_ops, .init = bpf_dummy_init, .check_member = bpf_dummy_ops_check_member, .init_member = bpf_dummy_init_member, .reg = bpf_dummy_reg, + .update = bpf_dummy_update, .unreg = bpf_dummy_unreg, .name = "bpf_dummy_ops", }; diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c index 13fc0c185cd9..558b01d5250f 100644 --- a/net/ipv4/bpf_tcp_ca.c +++ b/net/ipv4/bpf_tcp_ca.c @@ -239,8 +239,6 @@ static int bpf_tcp_ca_init_member(const struct btf_type *t, if (bpf_obj_name_cpy(tcp_ca->name, utcp_ca->name, sizeof(tcp_ca->name)) <= 0) return -EINVAL; - if (tcp_ca_find(utcp_ca->name)) - return -EEXIST; return 1; } @@ -266,10 +264,16 @@ static void bpf_tcp_ca_unreg(void *kdata) tcp_unregister_congestion_control(kdata); } +static int bpf_tcp_ca_update(void *kdata, void *old_kdata) +{ + return tcp_update_congestion_control(kdata, old_kdata); +} + struct bpf_struct_ops bpf_tcp_congestion_ops = { .verifier_ops = &bpf_tcp_ca_verifier_ops, .reg = bpf_tcp_ca_reg, .unreg = bpf_tcp_ca_unreg, + .update = bpf_tcp_ca_update, .check_member = bpf_tcp_ca_check_member, .init_member = bpf_tcp_ca_init_member, .init = bpf_tcp_ca_init, diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index db8b4b488c31..98d33dad9062 100644 --- a/net/ipv4/tcp_cong.c +++ b/net/ipv4/tcp_cong.c @@ -75,14 +75,8 @@ struct tcp_congestion_ops *tcp_ca_find_key(u32 key) return NULL; } -/* - * Attach new congestion control algorithm to the list - * of available options. - */ -int tcp_register_congestion_control(struct tcp_congestion_ops *ca) +int tcp_ca_validate(struct tcp_congestion_ops *ca) { - int ret = 0; - /* all algorithms must implement these */ if (!ca->ssthresh || !ca->undo_cwnd || !(ca->cong_avoid || ca->cong_control)) { @@ -90,6 +84,20 @@ int tcp_register_congestion_control(struct tcp_congestion_ops *ca) return -EINVAL; } + return 0; +} + +/* Attach new congestion control algorithm to the list + * of available options. + */ +int tcp_register_congestion_control(struct tcp_congestion_ops *ca) +{ + int ret; + + ret = tcp_ca_validate(ca); + if (ret) + return ret; + ca->key = jhash(ca->name, sizeof(ca->name), strlen(ca->name)); spin_lock(&tcp_cong_list_lock); @@ -130,6 +138,42 @@ void tcp_unregister_congestion_control(struct tcp_congestion_ops *ca) } EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control); +/* Replace a registered old ca with a new one. + * + * The new ca must have the same name as the old one, that has been + * registered. + */ +int tcp_update_congestion_control(struct tcp_congestion_ops *ca, struct tcp_congestion_ops *old_ca) +{ + struct tcp_congestion_ops *existing; + int ret; + + ret = tcp_ca_validate(ca); + if (ret) + return ret; + + ca->key = jhash(ca->name, sizeof(ca->name), strlen(ca->name)); + + spin_lock(&tcp_cong_list_lock); + existing = tcp_ca_find_key(ca->key); + if (ca->key == TCP_CA_UNSPEC || !existing || strcmp(existing->name, ca->name)) { + pr_notice("%s not registered or non-unique key\n", + ca->name); + ret = -EINVAL; + } else if (existing != old_ca) { + pr_notice("invalid old congestion control algorithm to replace\n"); + ret = -EINVAL; + } else { + list_del_rcu(&existing->list); + list_add_tail_rcu(&ca->list, &tcp_cong_list); + pr_debug("%s updated\n", ca->name); + } + spin_unlock(&tcp_cong_list_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(tcp_update_congestion_control); + u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_ca) { const struct tcp_congestion_ops *ca;