netdev - Re: [PATCH v2 net] vlan: Mask off vlan acceleration features on vlan 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:	Wed, 26 Mar 2014 20:53:12 -0400
From:	Vlad Yasevich <vyasevic@...hat.com>
To:	Patrick McHardy <kaber@...sh.net>,
	David Miller <davem@...emloft.net>
CC:	netdev@...r.kernel.org
Subject: Re: [PATCH v2 net] vlan: Mask off vlan acceleration features on vlan
 device.

On 03/26/2014 05:15 PM, Patrick McHardy wrote:
> On Wed, Mar 26, 2014 at 05:10:38PM -0400, David Miller wrote:
>> From: Vlad Yasevich <vyasevic@...hat.com>
>> Date: Wed, 26 Mar 2014 16:28:31 -0400
>>
>>> Some drivers incorrectly assign vlan acceleration features to
>>> vlan_features thus causing issues for Q-in-Q vlan configurations.
>>> Prevent this once and for all by masking off acceleration features
>>> for vlan devices until such time as we support stacked acceleration.
>>>
>>> Signed-off-by: Vlad Yasevich <vyasevic@...hat.com>
>>
>> So what if we do have chips that can offload Q-in-Q?  Will we use
>> a new flag?
> 
> For 802.1ad that was the intention, using the NETIF_F_HW_VLAN_STAG_* flags.
> 

But we can't really do that as we don't carry multiple vlan_tci in the
skb.  If the card advertises VLAN_STAG_*, then we'll offload that, but
CTAG will have to be computed by software.  More infrastructure is
needed to support nested vlan offloads.

-vlad
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html