Re: [PATCH v7 15/16] openvswitch: use new hashtable implementation

Tejun Heo
2012-10-29T18:22:18Z

Hello,

On Mon, Oct 29, 2012 at 02:16:48PM -0400, Mathieu Desnoyers wrote:
> This is just one example in an attempt to show why different hash table
> users may have different constraints: for a hash table entirely
> populated by keys generated internally by the kernel, a random seed
> might not be required, but for cases where values are fed by user-space
> and from the NIC, I would argue that flexibility to implement a
> randomizable hash function beats implementation simplicity any time.
>
> And you could keep the basic use-case simple by providing hints to the
> hash_32()/hash_64()/hash_ulong() helpers in comments.

If all you need is throwing in a salt value to avoid attacks, can't
you just do that from caller side? Scrambling the key before feeding
it into hash_*() should work, no?

Thanks.

--
tejun