[Oisf-devel] RFC: vlan_id in flow tracking

[Victor Julien]

On 04/08/2013 06:21 PM, Victor Julien wrote:
> On 04/08/2013 05:19 PM, Eric Leblond wrote:
>> Hi,
>>
>> On Mon, 2013-04-08 at 16:53 +0200, Victor Julien wrote:
>>> On 04/08/2013 03:47 PM, Eric Leblond wrote:
>>>> Hi,
>>>>
>>>> On Mon, 2013-04-08 at 15:13 +0200, Victor Julien wrote:
>>>>> On 04/08/2013 03:00 PM, Eric Leblond wrote:
>>>>>> Hi,
>>>>>>
>>>>>> On Mon, 2013-04-08 at 14:35 +0200, Victor Julien wrote:
>>>>>>> On 04/08/2013 01:44 PM, Eric Leblond wrote:
>>>>>>>> Hi,
>> ...
>>>>>> where Network (private IP for example) may be shared among client. And
>>>>>> if we have no luck, then we can cross beams and have two clients with
>>>>>> same network under the same VLAN. 
>>>>>
>>>>> Right, I think I get the point. If we would have:
>>>>>
>>>>> [vlan 1][vlan 2][client net 1]
>>>>> [vlan 2][vlan 2][client net 2]
>>>>>
>>>>> We might mix both as we first peel off the outer vlan and then have no
>>>>> way of distinguishing between the 2 client nets anymore, right?
>>>>
>>>> Exactly!
>>>>
>>>>> So if we have multiple layers, we'd need multiple tags in our flow hashing?
>>>>>
>>>>> [vlan 1][vlan 2][client net 1]
>>>>> [vlan 2][vlan 2][client net 2]
>>>>>
>>>>> Here both tag 1 and 2 would be needed to get flows for "client net 1"
>>>>> and tag 2 and 2 would be needed to get "client net 2". Make sense?
>>>>
>>>> Yes, this is the best behavior. 
>>>
>>> RFC:
>>> https://github.com/inliniac/suricata/commit/e2693b6ce6ae5f7e43da26b47fdc2220dc1c3fa5
>>
>> I've got few comments on it but to consider the perspective of MPLS
>> support. In this case, we will have the MPLS label to separate
>> clients/network in the same way has it is done with vlan id. Maybe we
>> could use a pointer inside the flow structure to indicate the
>> "separator" field. This would also be of use if we consider a set of GRE
>> tunnels used to separate network.
> 
> Not sure if we should consider MPLS at this time. We've discussed
> several ways to support it, including a flow engine per label. We'll get
> to that when the time is right :)
> 
> Wrt GRE, I've been browsing my pcap collection, but I can't seem to find
> something like a "vlan id" or "mpls label" in it. They "key" field isn't
> it I think.
> 
>>>>> In my patch I have a u16 for padding, so I could add support for dual
>>>>> layer vlans easily. For more... well that would be more work. Maybe we
>>>>> can just limit to 2 layers.
>>>>
>>>> From http://en.wikipedia.org/wiki/IEEE_802.1Q triple tagging is not
>>>> standard.
>>>
>>> I added a check for this in my RFC patch above.
>>
>> It seems clean.
>>
>>>> By the way, tagging host in the same way will be needed (thinking to
>>>> threshold mainly).
>>>
>>> Right. That is going to be interesting wrt IPrep :) Maybe I should move
>>> iprep out of the hosts.
>>
>> Yes, multi-client is something that would result in some complex and
>> huge work :)
> 
> Yeah. Taking it a step at a time...
> 

I've added a little doc here:
https://redmine.openinfosecfoundation.org/projects/suricata/wiki/VLAN_Handling

Also, for the flow part I have created this PR:
https://github.com/inliniac/suricata/pull/457 (bug 813 [1])

It includes a way to disable, set vlan.disabled to 'true' in the yaml.
Testing and review is welcome!

[1] https://redmine.openinfosecfoundation.org/issues/813

-- 
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Victor Julien
http://www.inliniac.net/
PGP: http://www.inliniac.net/victorjulien.asc
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