From mboxrd@z Thu Jan 1 00:00:00 1970 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 016DDC678D5 for ; Wed, 8 Mar 2023 00:51:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229529AbjCHAvI (ORCPT ); Tue, 7 Mar 2023 19:51:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229477AbjCHAvI (ORCPT ); Tue, 7 Mar 2023 19:51:08 -0500 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06A735ADD2 for ; Tue, 7 Mar 2023 16:51:03 -0800 (PST) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 32803ImT010351 for ; Tue, 7 Mar 2023 16:51:03 -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=SLft0s/6wnnZRzpYBgm1TmBZ2QcvTaBoPyzfcaVJIbI=; b=RPfqIHjAplrUIXyN5PPivnfV7gmSZTTj5EEOgzXUp0Fzqr72RKWXvOHyc2kA8i9zX0iF fcbH7C4HegEraXHg+hBOcQwmZQMWI/PvEMLcAvoBj6ZMMWUtTinDy7lNBSJwzW+eOUzW 8xYxLq1hRaUoQ3I/KCdHAgfNOnfRdeeDvxGKY1ztibv0fSSvam7z6nQ4JTWi1knufVnD NS8Mu8leD/WOxnWJLU8XWbqdV8/kmw7b6i3z2pa9Q6CtrW9ZkU6OElwgnDDM+cQy21j7 qLyXWtCfi9nDUdR3vGkdsaGaRE449Y7JTZ1pQ6+x7/r7D6w8eU3/5tfLdnr6+p1hVXqk 8g== Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3p6ffpr7gv-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 07 Mar 2023 16:51:03 -0800 Received: from twshared33736.38.frc1.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.17; Tue, 7 Mar 2023 16:51:02 -0800 Received: by devbig931.frc1.facebook.com (Postfix, from userid 460691) id 801B16C92E16; Tue, 7 Mar 2023 16:50:54 -0800 (PST) From: Kui-Feng Lee To: , , , , , , CC: Kui-Feng Lee Subject: [PATCH bpf-next v5 2/8] net: Update an existing TCP congestion control algorithm. Date: Tue, 7 Mar 2023 16:50:44 -0800 Message-ID: <20230308005050.255859-3-kuifeng@meta.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230308005050.255859-1-kuifeng@meta.com> References: <20230308005050.255859-1-kuifeng@meta.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: rAp-kyGPWfhfQYTnMDbpfB5tOyRyZGyQ X-Proofpoint-GUID: rAp-kyGPWfhfQYTnMDbpfB5tOyRyZGyQ X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-03-07_18,2023-03-07_01,2023-02-09_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org 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. The 'validate' function pointer has been added to bpf_struct_ops as well, allowing us to validate a struct_ops without having to go through the registration process. Signed-off-by: Kui-Feng Lee --- include/linux/bpf.h | 2 ++ include/net/tcp.h | 3 ++ net/bpf/bpf_dummy_struct_ops.c | 6 ++++ net/ipv4/bpf_tcp_ca.c | 14 +++++++-- net/ipv4/tcp_cong.c | 57 +++++++++++++++++++++++++++++----- 5 files changed, 73 insertions(+), 9 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 50cfc2388cbc..00b6e1a2edaf 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1512,6 +1512,8 @@ struct bpf_struct_ops { void *kdata, const void *udata); int (*reg)(void *kdata); void (*unreg)(void *kdata); + int (*update)(void *kdata, void *old_kdata); + int (*validate)(void *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..2abb755e6a3a 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1117,6 +1117,9 @@ struct tcp_congestion_ops { =20 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); +int tcp_validate_congestion_control(struct tcp_congestion_ops *ca); =20 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_op= s.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) { } =20 +static int bpf_dummy_update(void *kdata, void *old_kdata) +{ + return -EOPNOTSUPP; +} + struct bpf_struct_ops bpf_bpf_dummy_ops =3D { .verifier_ops =3D &bpf_dummy_verifier_ops, .init =3D bpf_dummy_init, .check_member =3D bpf_dummy_ops_check_member, .init_member =3D bpf_dummy_init_member, .reg =3D bpf_dummy_reg, + .update =3D bpf_dummy_update, .unreg =3D bpf_dummy_unreg, .name =3D "bpf_dummy_ops", }; diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c index 13fc0c185cd9..e8b27826283e 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_ty= pe *t, if (bpf_obj_name_cpy(tcp_ca->name, utcp_ca->name, sizeof(tcp_ca->name)) <=3D 0) return -EINVAL; - if (tcp_ca_find(utcp_ca->name)) - return -EEXIST; return 1; } =20 @@ -266,13 +264,25 @@ static void bpf_tcp_ca_unreg(void *kdata) tcp_unregister_congestion_control(kdata); } =20 +static int bpf_tcp_ca_update(void *kdata, void *old_kdata) +{ + return tcp_update_congestion_control(kdata, old_kdata); +} + +static int bpf_tcp_ca_validate(void *kdata) +{ + return tcp_validate_congestion_control(kdata); +} + struct bpf_struct_ops bpf_tcp_congestion_ops =3D { .verifier_ops =3D &bpf_tcp_ca_verifier_ops, .reg =3D bpf_tcp_ca_reg, .unreg =3D bpf_tcp_ca_unreg, + .update =3D bpf_tcp_ca_update, .check_member =3D bpf_tcp_ca_check_member, .init_member =3D bpf_tcp_ca_init_member, .init =3D bpf_tcp_ca_init, + .validate =3D bpf_tcp_ca_validate, .name =3D "tcp_congestion_ops", }; =20 diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c index db8b4b488c31..24829390e495 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; } =20 -/* - * Attach new congestion control algorithm to the list - * of available options. - */ -int tcp_register_congestion_control(struct tcp_congestion_ops *ca) +int tcp_validate_congestion_control(struct tcp_congestion_ops *ca) { - int ret =3D 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_congest= ion_ops *ca) return -EINVAL; } =20 + 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 =3D tcp_validate_congestion_control(ca); + if (ret) + return ret; + ca->key =3D jhash(ca->name, sizeof(ca->name), strlen(ca->name)); =20 spin_lock(&tcp_cong_list_lock); @@ -130,6 +138,41 @@ void tcp_unregister_congestion_control(struct tcp_co= ngestion_ops *ca) } EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control); =20 +/* 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 =3D tcp_validate_congestion_control(ca); + if (ret) + return ret; + + ca->key =3D jhash(ca->name, sizeof(ca->name), strlen(ca->name)); + + spin_lock(&tcp_cong_list_lock); + existing =3D tcp_ca_find_key(old_ca->key); + if (ca->key =3D=3D TCP_CA_UNSPEC || !existing || strcmp(existing->name,= ca->name)) { + pr_notice("%s not registered or non-unique key\n", + ca->name); + ret =3D -EINVAL; + } else if (existing !=3D old_ca) { + pr_notice("invalid old congestion control algorithm to replace\n"); + ret =3D -EINVAL; + } else { + list_add_tail_rcu(&ca->list, &tcp_cong_list); + list_del_rcu(&existing->list); + pr_debug("%s updated\n", ca->name); + } + spin_unlock(&tcp_cong_list_lock); + + return ret; +} + u32 tcp_ca_get_key_by_name(struct net *net, const char *name, bool *ecn_= ca) { const struct tcp_congestion_ops *ca; --=20 2.34.1