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 92F12CA0EC3 for ; Mon, 11 Sep 2023 21:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236879AbjIKVi1 (ORCPT ); Mon, 11 Sep 2023 17:38:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240015AbjIKOeF (ORCPT ); Mon, 11 Sep 2023 10:34:05 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0533E4D for ; Mon, 11 Sep 2023 07:34:00 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 447B8C433C8; Mon, 11 Sep 2023 14:34:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694442840; bh=iX3obZny8ndnEUgHY+rkvm5ocbb6U+6D+I/eVel8ops=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tuEKEpCEdB3MM9lNizV/g262Xs2Hs0CYKGF5bvmop0Ub9dGKVyFjyC/cjBETa8QGO twJ/HKWhExd8xP2GnZbge5M9BiBx18I86zaLhQ/a1+27/6QM/mrpOW4ywbj/Etlqcr OaScQRO6+GaJ21R0o+YJfDHrneceCSv6VCjoGdqg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kuniyuki Iwashima , Lorenz Bauer , Martin KaFai Lau , Sasha Levin Subject: [PATCH 6.4 166/737] udp: re-score reuseport groups when connected sockets are present Date: Mon, 11 Sep 2023 15:40:25 +0200 Message-ID: <20230911134655.150792408@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134650.286315610@linuxfoundation.org> References: <20230911134650.286315610@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lorenz Bauer [ Upstream commit f0ea27e7bfe1c34e1f451a63eb68faa1d4c3a86d ] 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.") Reviewed-by: Kuniyuki Iwashima Signed-off-by: Lorenz Bauer Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-1-7021b683cdae@isovalent.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin --- 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 6d327d6d978c5..a3302136ce92e 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -452,14 +452,24 @@ 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 8521729fb2375..9c7457823eb97 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -195,14 +195,23 @@ 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; -- 2.40.1