netdev - Re: [net-next PATCH v2 5/9] mlx4: Add support for UDP tunnel segmentation with outer checksum offload

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, 3 May 2016 15:41:57 +0300
From:	Or Gerlitz <ogerlitz@...lanox.com>
To:	Alexander Duyck <alexander.duyck@...il.com>
CC:	Or Gerlitz <gerlitz.or@...il.com>,
	Alexander Duyck <aduyck@...antis.com>,
	"talal@...lanox.com" <talal@...lanox.com>,
	Linux Netdev List <netdev@...r.kernel.org>,
	Michael Chan <michael.chan@...adcom.com>,
	"David Miller" <davem@...emloft.net>,
	Gal Pressman <galp@...lanox.com>,
	"Eran Ben Elisha" <eranbe@...lanox.com>
Subject: Re: [net-next PATCH v2 5/9] mlx4: Add support for UDP tunnel
 segmentation with outer checksum offload

On 5/2/2016 6:41 PM, Alexander Duyck wrote:
>> >Just one more piece to clarify... in the general case (e.g inner
>> >packet size 1.5k...64k), the last segment would not have the same
>> >length as the other segments, what happens on that case?
> Actually in the case of GSO partial we have go through the software
> segmentation code and trim off any last bit that doesn't match the MSS
> of the rest of the frame.  That way you end up with one frame that has
> some number of MSS sized chunks, and then one remainder if there is a
> frame that would be a different size.

OK, thanks for further clarifying this, will look on the docs you 
pointed etc. From what you wrote here I understand it's indeed possible 
for one frame to be of different size from the rest, but the LCO thing 
still works somehow..

Or.