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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05288C3F2D1 for ; Tue, 3 Mar 2020 17:45:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CFA6B208C3 for ; Tue, 3 Mar 2020 17:45:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583257504; bh=VHB/2UQrEaUcS1UIdXBYTk2YJO1lakDX0jwhcHajoT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qfZCZeXfiyvIWPUW4SliVM6OKSRJHzYSJIa6lOG26gkp3Nqy3xx3TYGVfvhg6vwLa oqHav86vTPeQ+BXtr22DciJTFA0NTIGFUJax7JPTWGSFKna406szKsgpyjVTJCzSFA z0Ds/q+wyQYMYT0ZAqsh2bN44suoqCZnqc8fwbYs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730859AbgCCRpD (ORCPT ); Tue, 3 Mar 2020 12:45:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:50736 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730838AbgCCRo6 (ORCPT ); Tue, 3 Mar 2020 12:44:58 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D47F9208C3; Tue, 3 Mar 2020 17:44:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583257497; bh=VHB/2UQrEaUcS1UIdXBYTk2YJO1lakDX0jwhcHajoT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cqw3P4v3owVjkAV90oF3YtO7d4zYZ4xq+wA0euZRvmOfgeNlr98tlGEB5BKEDhiMW 7iHJw5ifDoYLox2qbnBftwQX7MDZBJ0qyZfINWcUgd8fdSguhGZ6N+4+K8ieVjA/vz 0pM+8/b+FhsU1OfbGzaV6r96SRe3PdNpcDieCUw4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Benjamin Poirier , Michal Kubecek , "David S. Miller" Subject: [PATCH 5.5 019/176] ipv6: Fix route replacement with dev-only route Date: Tue, 3 Mar 2020 18:41:23 +0100 Message-Id: <20200303174306.774116370@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174304.593872177@linuxfoundation.org> References: <20200303174304.593872177@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Benjamin Poirier [ Upstream commit e404b8c7cfb31654c9024d497cec58a501501692 ] After commit 27596472473a ("ipv6: fix ECMP route replacement") it is no longer possible to replace an ECMP-able route by a non ECMP-able route. For example, ip route add 2001:db8::1/128 via fe80::1 dev dummy0 ip route replace 2001:db8::1/128 dev dummy0 does not work as expected. Tweak the replacement logic so that point 3 in the log of the above commit becomes: 3. If the new route is not ECMP-able, and no matching non-ECMP-able route exists, replace matching ECMP-able route (if any) or add the new route. We can now summarize the entire replace semantics to: When doing a replace, prefer replacing a matching route of the same "ECMP-able-ness" as the replace argument. If there is no such candidate, fallback to the first route found. Fixes: 27596472473a ("ipv6: fix ECMP route replacement") Signed-off-by: Benjamin Poirier Reviewed-by: Michal Kubecek Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ip6_fib.c | 7 ++++--- tools/testing/selftests/net/fib_tests.sh | 6 ++++++ 2 files changed, 10 insertions(+), 3 deletions(-) --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -1068,8 +1068,7 @@ static int fib6_add_rt2node(struct fib6_ found++; break; } - if (rt_can_ecmp) - fallback_ins = fallback_ins ?: ins; + fallback_ins = fallback_ins ?: ins; goto next_iter; } @@ -1112,7 +1111,9 @@ next_iter: } if (fallback_ins && !found) { - /* No ECMP-able route found, replace first non-ECMP one */ + /* No matching route with same ecmp-able-ness found, replace + * first matching route + */ ins = fallback_ins; iter = rcu_dereference_protected(*ins, lockdep_is_held(&rt->fib6_table->tb6_lock)); --- a/tools/testing/selftests/net/fib_tests.sh +++ b/tools/testing/selftests/net/fib_tests.sh @@ -910,6 +910,12 @@ ipv6_rt_replace_mpath() check_route6 "2001:db8:104::/64 via 2001:db8:101::3 dev veth1 metric 1024" log_test $? 0 "Multipath with single path via multipath attribute" + # multipath with dev-only + add_initial_route6 "nexthop via 2001:db8:101::2 nexthop via 2001:db8:103::2" + run_cmd "$IP -6 ro replace 2001:db8:104::/64 dev veth1" + check_route6 "2001:db8:104::/64 dev veth1 metric 1024" + log_test $? 0 "Multipath with dev-only" + # route replace fails - invalid nexthop 1 add_initial_route6 "nexthop via 2001:db8:101::2 nexthop via 2001:db8:103::2" run_cmd "$IP -6 ro replace 2001:db8:104::/64 nexthop via 2001:db8:111::3 nexthop via 2001:db8:103::3"