netdev - Re: Connection tracking and vlan

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Date:	Mon, 2 Nov 2009 11:30:16 -0500
From:	Adayadil Thomas <adayadil.thomas@...il.com>
To:	Ben Greear <greearb@...delatech.com>
Cc:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Eric Dumazet <eric.dumazet@...il.com>,
	Herbert Xu <herbert@...dor.apana.org.au>,
	netdev@...r.kernel.org, Patrick McHardy <kaber@...sh.net>
Subject: Re: Connection tracking and vlan

A small correction to the patch. Thanks for any comments you can
provide on this patch.

Thanks


On Mon, Nov 2, 2009 at 11:14 AM, Adayadil Thomas
<adayadil.thomas@...il.com> wrote:
> If the vlan id is used for hash, it still may not avoid the problem completely,
> i.e. in case of both connections hashing to the same bucket.
>
> I was wondering about your opinion about adding an optional member to the tuple
> structure, vid (for vlan id).
>
> I have attached the patch for this change. I would be grateful for any comments
> such as dependencies on the rest of the system.
>
>
> Thanks much
>
>
>
> On Fri, Oct 30, 2009 at 6:25 PM, Ben Greear <greearb@...delatech.com> wrote:
>> On 10/30/2009 04:15 PM, Eric W. Biederman wrote:
>>
>>>> If ip_conntrack does not consider vlans, it is possible that all 5
>>>> tuple are the same
>>>> and thus affect the connection tracking.
>>>>
>>>> I hope I have described the scenario well. If not I can explain in a
>>>> more detailed fashion.
>>>
>>> Unless you have multiple network namespaces linux assumes all packets are
>>> in the same ip space.  And 10.10.10.1 is the same machine no matter
>>> which interface you talk to it on.
>>
>> It only takes a relatively small patch that lets conn-track hash on a
>> skb->foo_mark, and allow that mark to be set on incoming packets
>> based on netdevice or whatever, (before the conn-track lookup is
>> done).
>>
>> This is logically somewhat similar to using multiple routing
>> tables and has been working well for me for several years....
>>
>> Thanks,
>> Ben
>>
>> --
>> Ben Greear <greearb@...delatech.com>
>> Candela Technologies Inc  http://www.candelatech.com
>>
>>
>

View attachment "patch1.txt" of type "text/plain" (7137 bytes)