From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4C61A1B78F3 for ; Sun, 22 Mar 2026 17:03:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774199032; cv=none; b=TgOPTo9AGaDbEn+KvWLnYqW8MnB4nMdPCY5zTG9lluLr5tNktB+J/rq2AmWrGETAKLOq3QpRN7/LZsdsmCDLeippSiTcsWnS3JlN/EYXJj6KlYtZO+9wUpdTvNhIWLTulIh5rkPom4GQqfmFyuZKTGmCjlTjWoON0kBo3XbvqmQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774199032; c=relaxed/simple; bh=ZJtDWF5fTrJf70UH91Lb9W/VgidUdUCsqMJqFqEjLT4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UZCMLtDP86uJgZRo6p/zqdrunlH3lwf1Jd5b/QCixnGWAwXEPpjvXqDLqNHdFGsx4OVJvUAZF16FXYLaasJ7HULEMBs2WzKExif2O/bhnIjN+l8JAReMc1dOApgr0E1d1KykV9kUv/3kXarYI2ENGkaTepAhMcXYK6K+9mIUStU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Y9SLQssR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Y9SLQssR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 859D2C19424; Sun, 22 Mar 2026 17:03:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774199031; bh=ZJtDWF5fTrJf70UH91Lb9W/VgidUdUCsqMJqFqEjLT4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Y9SLQssRO8LpIG7cgfTRssC8u7I71i3T5lFV65De0YhTBqA6mYhSZcTQx/FtrMhDQ iv0XkqdvpGvYJdcN8UA09ADb+PX109/NFBwS5tJb/jEUNRgSIcFrtAlddXQiYEBKc0 yelcoNMf1NYszMly8vG961TOLA90XD7RMkNh2rW7qO9FGHXCKPnzxqxeBBSyGv5p2U HHZTiFugE42Rl2V8bj89ZGSdA4WipE41UmgGomKvS4a3qoekGLE93W0teAovqsCnzp 8KhoocBT6jC5h5XbSpCHrlTclRwYYQ8hPQLHYD484ctnn7GuAOOzMAI0Tf4pGDVb8t gOKSD7Pd/T4kw== Message-ID: Date: Sun, 22 Mar 2026 11:03:50 -0600 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 net 3/3] selftest: net: Add GC test for temporary routes with exceptions. Content-Language: en-US To: Kuniyuki Iwashima , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Kui-Feng Lee , Xin Long , Simon Horman , Kuniyuki Iwashima , netdev@vger.kernel.org References: <20260320072317.2561779-1-kuniyu@google.com> <20260320072317.2561779-4-kuniyu@google.com> From: David Ahern In-Reply-To: <20260320072317.2561779-4-kuniyu@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/20/26 1:23 AM, Kuniyuki Iwashima wrote: > Without the prior commit, IPv6 GC cannot track exceptions tied > to permanent routes if they were originally added as temporary > routes. > > Let's add a test case for the issue. > > 1. Add temporary routes > 2. Create exceptions for the temporary routes > 3. Promote the routes to permanent routes > 4. Check if GC can find and purge the exceptions > > A few notes: > > + At step 4, unlike other test cases, we cannot wait for > $GC_WAIT_TIME. While the exceptions are always iterable via > netlink (since it traverses the entire fib tree instead of > tb6_gc_hlist), rt6_nh_dump_exceptions() skips expired entries. > > If we waited for the expiration time, we would be unable to > distinguish whether the exceptions were truly purged by GC or > just hidden due to being expired. > > + For the same reason, at step 2, we use ICMPv6 redirect message > instead of Packet Too Big message. This is because MTU exceptions > always have RTF_EXPIRES, and rt6_age_examine_exception() does not > respect the period specified by net.ipv6.route.flush=1. > > + We add a neighbour entry for the redirect target with NTF_ROUTER. > Without this, the exceptions would be removed at step 3 when the > fib6_may_remove_gc_list() is called. > > Without the fix, the exceptions remain even after GC is triggered > by sysctl -wq net.ipv6.route.flush=1. > > FAIL: Expected 0 routes, got 5 > TEST: ipv6 route garbage collection (promote to permanent routes) [FAIL] > > With the fix, GC purges the exceptions properly. > > TEST: ipv6 route garbage collection (promote to permanent routes) [ OK ] > > Signed-off-by: Kuniyuki Iwashima > --- > tools/testing/selftests/net/fib_tests.sh | 61 ++++++++++++++++++++++-- > 1 file changed, 58 insertions(+), 3 deletions(-) > Reviewed-by: David Ahern