Re: kern/57155: OpenVPN (tap and tun) doesn't run as expected on 10.0_BETA

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

On Thu, Jan 5, 2023 at 3:50 PM BERTRAND Joël <joel.bertrand%systella.fr@localhost> wrote:
>
> Ryota Ozaki a écrit :
> >  Oh, sorry. You also need to grep with "discard" to see all packet drops.
>
> Main server:
>
> legendre# netstat -s | grep discard
>                 0 discarded for bad checksums
>                 0 discarded for bad header offset fields
>                 0 discarded because packet too short
>         0 output packets discarded due to no route
>         0 output packets discarded due to reject route
>                 0 packets discarded for bad interface
>                 0 packets discarded for wrong TTL
>                 0 packets discarded for bad checksum
>                 0 packets discarded with a bad version
>                 0 discarded because packet was too short
>                 0 packets discarded for bad authentication
>                 0 packets discarded for bad vhid
>                 0 packets discarded because of a bad address list
>         276 output packets discarded due to no route
>         0 packets discarded due to too many headers
>         0 output packets discarded due to reject route
>                 0 discarded for bad checksums
>                 0 discarded for bad header offset fields
>                 0 discarded because packet too short
>
> VM:
>
> netbsd-test1# netstat -s | grep discard
>                 0 discarded for bad checksums
>                 0 discarded for bad header offset fields
>                 0 discarded because packet too short
>         0 output packets discarded due to no route
>         0 output packets discarded due to reject route
>                 0 packets discarded for bad interface
>                 0 packets discarded for wrong TTL
>                 0 packets discarded for bad checksum
>                 0 packets discarded with a bad version
>                 0 discarded because packet was too short
>                 0 packets discarded for bad authentication
>                 0 packets discarded for bad vhid
>                 0 packets discarded because of a bad address list
>         0 output packets discarded due to no route
>         0 packets discarded due to too many headers
>         0 output packets discarded due to reject route
>                 0 discarded for bad checksums
>                 0 discarded for bad header offset fields
>                 0 discarded because packet too short

Thanks.

"packets discarded due to no route" may be related to the issue,
but I'm not sure for now.

>
>
> >  Anyway thank you for the outputs and the explanation on the other reply.
> >  I've got the situation.
> >
> >  I have one question. Does this issue happen with a vanilla kernel?
> >  Or only with your custom kernel?
>
>         legendre runs with a customized kernel (GENERIC + altq + iscsi).
> netbsd-test1 runs with a GENERIC kernel (from iso install image).

I've tried a kernel with the same configuration. It seems to me that
ALTQ and iscsi are not related to the issue.

Anyway I've finally found a setup to reproduce the issue (or something).
At least it's a regression.

It's a tap version of your simple setup:
[server] openvpn --dev tap --ifconfig 10.4.0.1 255.255.255.0 --verb 1
--local 10.6.0.9 --proto tcp-server
[client] openvpn --remote 10.6.0.9 --dev tap --ifconfig 10.4.0.2
255.255.255.0 --proto tcp-client --verb 1 --float --ping 10

It works with NetBSD 9 & Linux, however, doesn't work with NetBSD 10 & Linux
and NetBSD 10 & NetBSD 9.

I haven't reproduced the issue with tun but anyway I'm investigating the issue
with the setup first.

Thanks,
  ozaki-r