linux-kernel - Re: [PATCH v11 13/17] Add mp(mediate passthru) device.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 28 Sep 2010 17:18:15 +0200
From:	Arnd Bergmann <arnd@...db.de>
To:	"Michael S. Tsirkin" <mst@...hat.com>
Cc:	Ben Hutchings <bhutchings@...arflare.com>, xiaohui.xin@...el.com,
	netdev@...r.kernel.org, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org, mingo@...e.hu, davem@...emloft.net,
	herbert@...dor.hengli.com.au, jdike@...ux.intel.com,
	Sridhar Samudrala <sri@...ibm.com>
Subject: Re: [PATCH v11 13/17] Add mp(mediate passthru) device.

On Tuesday 28 September 2010, Michael S. Tsirkin wrote:
> On Tue, Sep 28, 2010 at 04:39:59PM +0200, Arnd Bergmann wrote:
> > Can you be more specific what the problem is? Do you think
> > it breaks when a guest sends VLAN tagged frames or when macvtap
> > is connected to a VLAN interface that adds another tag (or
> > only the combination)?
>
> I expect the protocol value to be wrong when guest sends vlan tagged
> frames as 802.1q frames have a different format.

Ok, I see. Would that be fixed by using eth_type_trans()? I don't
see any code in there that tries to deal with the VLAN tag, so
do we have the same problem in the tun/tap driver?

Also, I wonder how we handle the case where both the guest and
the host do VLAN tagging. Does the host transparently override
the guest tag, or does it add a nested tag? More importantly,
what should it do?

	Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/