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 AC6C5481D4 for ; Fri, 8 Dec 2023 19:21:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fwWuH2aV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E676C433C7; Fri, 8 Dec 2023 19:21:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1702063316; bh=m2N0reCrYzufIq74ZjOW3IINxWdpl5ajaPh74HTVtfY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=fwWuH2aVOfIx3ohpnJC1NML+Fk85e/5BlTVQBfMXZMP0C8QynLb5MpS0+Goirjyab 7SGNWrT1LVhLs1MSQvpieQyuAt3G9dIkT75nA42np9pmvg+6/Ouf3Xe3p7hDlf8mlJ YrxuLfNdqij2cPy+JkKZ3qlkcnuPsSfEdyX+/pD2aFpxjwZ8Df0KJTATwRISCZ1zAq ZvtNNUHxmzbMOIFh2AgKOa2HbgjlCLqaG4KcCF2M2JMGbdgFCaXVlcgF1TyDHi+GPw +eZUrKy4Ow7kuyhkGZtFEZ86CZT05ip88D7AavU3gWIdmg4hhFH7ccmhaFqmWwBhZ/ g1STaHB8fg0hw== Message-ID: <02ef5de4-d57f-4037-8968-d9bf791bd903@kernel.org> Date: Fri, 8 Dec 2023 12:21:55 -0700 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: selftest fib_nexthop_multiprefix failed due to route mismatch Content-Language: en-US To: Hangbin Liu Cc: netdev@vger.kernel.org References: <01240884-fcc9-46d5-ae98-305151112ebc@kernel.org> From: David Ahern In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/5/23 8:47 PM, Hangbin Liu wrote: > On Tue, Nov 21, 2023 at 09:40:02AM -0800, David Ahern wrote: >> On 11/20/23 10:40 PM, Hangbin Liu wrote: >>> Hi David, >>> >>> Recently when run fib_nexthop_multiprefix test I saw all IPv6 test failed. >>> e.g. >>> >>> # ./fib_nexthop_multiprefix.sh >>> TEST: IPv4: host 0 to host 1, mtu 1300 [ OK ] >>> TEST: IPv6: host 0 to host 1, mtu 1300 [FAIL] >>> >>> With -v it shows >>> >>> COMMAND: ip netns exec h0 /usr/sbin/ping6 -s 1350 -c5 -w5 2001:db8:101::1 >>> PING 2001:db8:101::1(2001:db8:101::1) 1350 data bytes >>> From 2001:db8:100::64 icmp_seq=1 Packet too big: mtu=1300 >>> >>> --- 2001:db8:101::1 ping statistics --- >>> 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms >>> >>> Route get >>> 2001:db8:101::1 via 2001:db8:100::64 dev eth0 src 2001:db8:100::1 metric 1024 expires 599sec mtu 1300 pref medium >>> Searching for: >>> 2001:db8:101::1 from :: via 2001:db8:100::64 dev eth0 src 2001:db8:100::1 .* mtu 1300 >>> >>> TEST: IPv6: host 0 to host 1, mtu 1300 [FAIL] >>> >>> So we can get the Packet too big from 2001:db8:100::64 successfully. There >>> is no "from ::" anymore. I plan to fix this issue. But I can't find which >>> commit changed the behavior and the client could receive Packet too big >>> message with correct src address. >>> >>> Do you have any hints? >>> >>> Thanks >>> Hangbin >> >> v6.3.12: >> >> $ sudo /mnt/hostshare/fib_nexthop_multiprefix.sh >> TEST: IPv4: host 0 to host 1, mtu 1300 [ OK ] >> TEST: IPv6: host 0 to host 1, mtu 1300 [ OK ] >> >> v6.4.13 all passed as well, so it is something recent. I do not have a >> 6.5 or 6.6 kernels compiled at the moment. > > Hi David, > > I re-test this on 6.4.0 and it also failed. So this looks like an env issue > on your side? > > # uname -r > 6.4.0 > # ./fib_nexthop_multiprefix.sh > TEST: IPv4: host 0 to host 1, mtu 1300 [ OK ] > TEST: IPv6: host 0 to host 1, mtu 1300 [FAIL] > > And from the test result, it looks we should receive the Packet too big message > from r1. So look the current checking is incorrect and the "from ::" checking > should be removed. > > Please fix me if I missed anything? > I ran it in a ubuntu 20.04 VM. Do not recall any specific sysctl settings to the VM, but maybe something is different between U20.04 and your OS