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

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

The following reply was made to PR kern/57155; it has been noted by GNATS.

From: Ryota Ozaki <ozaki-r%netbsd.org@localhost>
To: =?UTF-8?Q?BERTRAND_Jo=C3=ABl?= <joel.bertrand%systella.fr@localhost>
Cc: gnats-bugs%netbsd.org@localhost, kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, 
	netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/57155: OpenVPN (tap and tun) doesn't run as expected on 10.0_BETA
Date: Fri, 6 Jan 2023 15:03:26 +0900

 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 Jo=C3=ABl <joel.bertrand@systella=
 .fr> wrote:
 > >
 > > Ryota Ozaki a =C3=A9crit :
 > > >  Oh, sorry. You also need to grep with "discard" to see all packet dr=
 ops.
 > >
 > > 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 re=
 ply.
 > > >  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 & Li=
 nux
 > 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