From patchwork Mon Jun 26 15:08:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenz Bauer X-Patchwork-Id: 696751 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 0E9C9EB64DC for ; Mon, 26 Jun 2023 15:09:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230303AbjFZPJT (ORCPT ); Mon, 26 Jun 2023 11:09:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbjFZPJR (ORCPT ); Mon, 26 Jun 2023 11:09:17 -0400 Received: from mail-wr1-x42e.google.com (mail-wr1-x42e.google.com [IPv6:2a00:1450:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11A18130 for ; Mon, 26 Jun 2023 08:09:15 -0700 (PDT) Received: by mail-wr1-x42e.google.com with SMTP id ffacd0b85a97d-312863a983fso3939129f8f.2 for ; Mon, 26 Jun 2023 08:09:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isovalent.com; s=google; t=1687792153; x=1690384153; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=aFcQRDCnPx+ynCpnF2uFrs+TLwer8UbpK1ON+IZqGjg=; b=Bdh0fSQLic8GK24HDf3N/rYsDXp0g5q1AXTN6FF2vyHtYHXt1iEdesUewz6eGR40Ed 9QFHTXPmVxvxWjLFJO4riKrSrGvBsSy2Rw4MrLgYCTc4GuDKvtSZ6Jr2jYH44BwP0ewD uuQ3mh+NJQGkk5OyGdPSCiECAmJMPo8d7YoAn5GsINQN0VYx0iU7dxh2Qwtb8vP6LCQh VZ195sjvz5hSuhSGswffFJdVCftH2DnZi/geebX3tQSNCyZvJKPwaaqfGWBjf3TZ2HUt JLbVUSEEJSj0wLm3Ww9IwuENK+ch0qGYbRN3NC7ULa2rmv8kfwWEIdnxDcYrkXzx416g AmTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687792153; x=1690384153; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=aFcQRDCnPx+ynCpnF2uFrs+TLwer8UbpK1ON+IZqGjg=; b=LD+ipUyUI29VbSieE2gucw3yba9fz8lacRE5sT7C3TJfuXx9T+DTfdetnv0QA6k+jm l2YIzOqR8CVjfDk44I/olnmb6V6vTCPIN6gHNTYQHInHx5eDvvL3ECQlfU8v3GCZntoA 7yGiCAb8nsVvuod3cIWkQ8r0KYv4+90G+qwkI/0DRnk02bVZZfmYnRYX6w3CEjECccr5 KSFJVSyHyn9zdvC6/wH06PFWPofXbPIyxFT10Az2V45w3rcsG6soRByXRlZUlpvPqH90 ICfUkX3OoxoAMfwjyUmaR6KaT5oRbc9cGzmiM4PYMRpIcrWa9H7GR2ASaDT3WJ6yp5XN g8KQ== X-Gm-Message-State: AC+VfDyIahTWzLizzl3/0tDCeNE0C4W2UJvVBuWj4lg3cftAmuZgIoRp F/WLxG1X9rI6OuchKPB2w0oiEA== X-Google-Smtp-Source: ACHHUZ4tGG8fHK6H7JRwd23ypMKZA5H9umKPvcqfyKGjq7sH0yQK3kam6nswRSMg68RE5TI41cFW6A== X-Received: by 2002:adf:ec03:0:b0:306:36ef:2e3b with SMTP id x3-20020adfec03000000b0030636ef2e3bmr22381550wrn.70.1687792153406; Mon, 26 Jun 2023 08:09:13 -0700 (PDT) Received: from [192.168.1.193] (f.c.7.0.0.0.0.0.0.0.0.0.0.0.0.0.f.f.6.2.a.5.a.7.0.b.8.0.1.0.0.2.ip6.arpa. [2001:8b0:7a5a:26ff::7cf]) by smtp.gmail.com with ESMTPSA id v1-20020adfe281000000b00311299df211sm7668710wri.77.2023.06.26.08.09.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 08:09:13 -0700 (PDT) From: Lorenz Bauer Date: Mon, 26 Jun 2023 16:08:58 +0100 Subject: [PATCH bpf-next v3 1/7] udp: re-score reuseport groups when connected sockets are present MIME-Version: 1.0 Message-Id: <20230613-so-reuseport-v3-1-907b4cbb7b99@isovalent.com> References: <20230613-so-reuseport-v3-0-907b4cbb7b99@isovalent.com> In-Reply-To: <20230613-so-reuseport-v3-0-907b4cbb7b99@isovalent.com> To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern , Willem de Bruijn , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Joe Stringer , Mykola Lysenko , Shuah Khan , Kuniyuki Iwashima Cc: Hemanth Malla , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, Lorenz Bauer X-Mailer: b4 0.12.2 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Contrary to TCP, UDP reuseport groups can contain TCP_ESTABLISHED sockets. To support these properly we remember whether a group has a connected socket and skip the fast reuseport early-return. In effect we continue scoring all reuseport sockets and then choose the one with the highest score. The current code fails to re-calculate the score for the result of lookup_reuseport. According to Kuniyuki Iwashima: 1) SO_INCOMING_CPU is set -> selected sk might have +1 score 2) BPF prog returns ESTABLISHED and/or SO_INCOMING_CPU sk -> selected sk will have more than 8 Using the old score could trigger more lookups depending on the order that sockets are created. sk -> sk (SO_INCOMING_CPU) -> sk (ESTABLISHED) | | `-> select the next SO_INCOMING_CPU sk | `-> select itself (We should save this lookup) Fixes: efc6b6f6c311 ("udp: Improve load balancing for SO_REUSEPORT.") Signed-off-by: Lorenz Bauer --- net/ipv4/udp.c | 20 +++++++++++++++----- net/ipv6/udp.c | 19 ++++++++++++++----- 2 files changed, 29 insertions(+), 10 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index fd3dae081f3a..5ef478d2c408 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -450,14 +450,24 @@ static struct sock *udp4_lib_lookup2(struct net *net, score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, sdif); if (score > badness) { - result = lookup_reuseport(net, sk, skb, - saddr, sport, daddr, hnum); + badness = score; + result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (!result) { + result = sk; + continue; + } + /* Fall back to scoring if group has connections */ - if (result && !reuseport_has_conns(sk)) + if (!reuseport_has_conns(sk)) return result; - result = result ? : sk; - badness = score; + /* Reuseport logic returned an error, keep original score. */ + if (IS_ERR(result)) + continue; + + badness = compute_score(result, net, saddr, sport, + daddr, hnum, dif, sdif); + } } return result; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index e5a337e6b970..8b3cb1d7da7c 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -193,14 +193,23 @@ static struct sock *udp6_lib_lookup2(struct net *net, score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, sdif); if (score > badness) { - result = lookup_reuseport(net, sk, skb, - saddr, sport, daddr, hnum); + badness = score; + result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (!result) { + result = sk; + continue; + } + /* Fall back to scoring if group has connections */ - if (result && !reuseport_has_conns(sk)) + if (!reuseport_has_conns(sk)) return result; - result = result ? : sk; - badness = score; + /* Reuseport logic returned an error, keep original score. */ + if (IS_ERR(result)) + continue; + + badness = compute_score(sk, net, saddr, sport, + daddr, hnum, dif, sdif); } } return result;