netdev - Re: [PATCH net-next] openvswitch: correctly fragment packet with mpls headers

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]

Message-ID: <CAOrHB_C55GM=AfYj43VJ-hPRZfwFxm_+8Ls2+7mck2Js1fy9-w@mail.gmail.com>
Date:   Tue, 4 Oct 2016 09:53:25 -0700
From:   Pravin Shelar <pshelar@....org>
To:     Jiri Benc <jbenc@...hat.com>
Cc:     Linux Kernel Network Developers <netdev@...r.kernel.org>,
        David Ahern <dsa@...ulusnetworks.com>
Subject: Re: [PATCH net-next] openvswitch: correctly fragment packet with mpls headers

On Tue, Oct 4, 2016 at 2:28 AM, Jiri Benc <jbenc@...hat.com> wrote:
> On Tue, 4 Oct 2016 10:24:58 +0200, Jiri Benc wrote:
>> On Mon, 3 Oct 2016 11:04:46 -0700, Pravin Shelar wrote:
>> > This is not correct way to detect MPLS packet. inner_protocol can be
>> > set by any tunnel device for using tunnel offloads. So this would
>> > break the fragmentation for encapsulated packets.
>>
>> You're right, stupid me.
>
> Actually, too little caffeine in the morning. I actually did consider
> this and I believe my patch is correct. It doesn't matter what the
> encapsulation is, we want to fragment the *inner* packet. And this is
> exactly what this patch does.
>
> Besides, the only case is MPLS anyway. I'm not aware of any code path
> that could lead us to here, set inner protocol and not be MPLS. But
> even if it is, it should work, provided the encapsulation header is
> identical for all fragments and smaller than MAX_L2_LEN.
>

This code can be executed on encapsulated geneve or vxlan packets. So
in that case encapsulation header would not be same for all fragments.