From: Miroslav Lichvar <mlichvar@redhat.com>
To: Richard Cochran <richardcochran@gmail.com>
Cc: Jiri Benc <jbenc@redhat.com>, Hangbin Liu <liuhangbin@gmail.com>,
netdev@vger.kernel.org, David Miller <davem@davemloft.net>,
Patrick McHardy <kaber@trash.net>,
stefan.sorensen@spectralink.com
Subject: Re: [PATCH net-next] macvlan: pass get_ts_info and SIOC[SG]HWTSTAMP ioctl to real device
Date: Thu, 18 Apr 2019 10:05:09 +0200 [thread overview]
Message-ID: <20190418080509.GD5984@localhost> (raw)
In-Reply-To: <20190418033157.irs25halxnemh65y@localhost>
On Wed, Apr 17, 2019 at 08:31:57PM -0700, Richard Cochran wrote:
> On Wed, Apr 17, 2019 at 08:59:58PM +0200, Jiri Benc wrote:
> > The problem here is this patch gives access to physical interface
> > settings through a virtual interface layered on top of it. Whenever
> > such thing is done, the virtual interface needs to provide a suitable
> > way of moderating access to the shared resources, so the individual
> > virtual interfaces do not affect each other. That's not what's being
> > done here.
>
> So I guess the macvlan should reject SIOCSHWTSTAMP but allow
> SIOCGHWTSTAMP.
FWIW, my suggestion was to limit what the SIOCSHWTSTAMP ioctl can do
on the virtual interface. It could only enable HW timestamping or
select a more general filter. A container could run a PTP clock if it
had also access to the PHC device, or it could have the NET_ADMIN
capability for other reasons, but it couldn't disable HW timestamping
enabled by the host or other container.
If I understand it correctly, even without this ioctl a container can
prevent the host or other containers from getting some of the HW
timestamps by requesting TX timestamps at a high rate. I suspect the
timestamping would need to be restricted to the real interface to
fully protect it from applications having access to the virtual
interfaces.
--
Miroslav Lichvar
next prev parent reply other threads:[~2019-04-18 8:05 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-20 2:23 [PATCH net-next] macvlan: pass get_ts_info and SIOC[SG]HWTSTAMP ioctl to real device Hangbin Liu
2019-03-20 18:05 ` David Miller
2019-04-17 8:05 ` Hangbin Liu
2019-04-17 15:43 ` Richard Cochran
2019-04-17 18:59 ` Jiri Benc
2019-04-18 3:31 ` Richard Cochran
2019-04-18 6:10 ` Hangbin Liu
2019-04-18 8:05 ` Miroslav Lichvar [this message]
2019-04-23 4:18 ` Hangbin Liu
2019-04-23 8:31 ` Miroslav Lichvar
2019-04-23 9:15 ` Hangbin Liu
2019-04-23 9:32 ` Miroslav Lichvar
2019-04-25 13:40 ` Hangbin Liu
2019-05-06 7:34 ` Hangbin Liu
2019-05-06 14:01 ` Richard Cochran
2019-05-07 8:35 ` Miroslav Lichvar
2019-05-08 1:41 ` Hangbin Liu
2019-05-08 13:58 ` Michal Kubecek
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