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 7:45 PM Ryota Ozaki <ozaki-r%netbsd.org@localhost> wrote:
>
> 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.

I've fixed a regression of tap. Could you try the fix (if_tap.c,v 1.128)?

Thanks,
  ozaki-r