Re: POSSIBLE BUG: selftests/net/fcnal-test.sh: [FAIL][FIX TESTED] in vrf "bind - ns-B IPv6 LLA" test

[Guillaume Nault <gnault@redhat.com>]

On Sat, Jun 10, 2023 at 08:04:02PM +0200, Mirsad Goran Todorovac wrote:
> This also works on the Lenovo IdeaPad 3 Ubuntu 22.10 laptop, but on the AlmaLinux 8.8
> Lenovo desktop I have a problem:
> 
> [root@pc-mtodorov net]# grep FAIL ../fcnal-test-4.log
> TEST: ping local, VRF bind - ns-A IP                                          [FAIL]
> TEST: ping local, VRF bind - VRF IP                                           [FAIL]
> TEST: ping local, device bind - ns-A IP                                       [FAIL]
> TEST: ping local, VRF bind - ns-A IP                                          [FAIL]
> TEST: ping local, VRF bind - VRF IP                                           [FAIL]
> TEST: ping local, device bind - ns-A IP                                       [FAIL]
> [root@pc-mtodorov net]#
> 
> Kernel is the recent one:
> 
> [root@pc-mtodorov net]# uname -rms
> Linux 6.4.0-rc5-testnet-00003-g5b23878f7ed9 x86_64
> [root@pc-mtodorov net]#

Maybe a problem with the ping version used by the distribution.
You can try "./fcnal-test.sh -t ipv4_ping -p -v" to view the commands
run and make the script stop when there's a test failure (so that you
can see the ping output and try your own commands in the testing
environment).

> > > However, I have a question:
> > > 
> > > In the ping + "With VRF" section, the tests with net.ipv4.raw_l3mdev_accept=1
> > > are repeated twice, while "No VRF" section has the versions:
> > > 
> > > SYSCTL: net.ipv4.raw_l3mdev_accept=0
> > > 
> > > and
> > > 
> > > SYSCTL: net.ipv4.raw_l3mdev_accept=1
> > > 
> > > The same happens with the IPv6 ping tests.
> > > 
> > > In that case, it could be that we have only 2 actual FAIL cases,
> > > because the error is reported twice.
> > > 
> > > Is this intentional?
> > 
> > I don't know why the non-VRF tests are run once with raw_l3mdev_accept=0
> > and once with raw_l3mdev_accept=1. Unless I'm missing something, this
> > option shouldn't affect non-VRF users. Maybe the objective is to make
> > sure that it really doesn't affect them. David certainly knows better.
> 
> The problem appears to be that non-VRF tests are being ran with
> raw_l3mdev_accept={0|1}, while VRF tests w raw_l3mdev_accept={1|1} ...

The reason the VRF tests run twice is to test both raw and ping sockets
(using the "net.ipv4.ping_group_range" sysctl). It doesn't seem anyone
ever intended to run the VRF tests with raw_l3mdev_accept=0.

Only the non-VRF tests were intended to be tested with
raw_l3mdev_accept=0 (see commit c032dd8cc7e2 ("selftests: Add ipv4 ping
tests to fcnal-test")). But I have no idea why.

> I will try to fix that, but I am not sure of the semantics either.
> 
> Regards,
> Mirsad
>