[VLAN] macvlan_config

[Ben Greear]

Alex Zeffertt wrote:
> Ben Greear wrote:
> 
>> Ard van Breemen wrote:
>>
>>> Hello Ben,
>>> I want to start supporting macvlan's in debian (with debian style
>>> "auto" configuration).
>>> I'm just not so charmed with the name macvlan_config.
>>> Is it ok if I rename that (in the resulting package) to mvconfig?
>>
>>
>> That is fine by me.
>>
>>> I think that macvlan's are essential if you want to do "pure"
>>> vrrp implementations (with mac-address failover).
>>
>>
>> I have re-written the mac-vlan patch a bit lately, primarily to
>> simplify the code and remove functionality I never used (and thus, 
>> never tested.)
>>
>> The main changes:
>>
>> *  Allow only matching on the destination MAC, not the source.
>>
> 
> 
> Uh?  Surely source MAC matching is what MAC address based VLANs
> (on any platform) should be about.  So that you can group hosts into
> VLANs.
> 
> 
>> *  Allow only matching a single MAC address, not a list.
>>    (Removed the hash lookup logic as well.)
>>
> 
> Why? Surely the point of VLANs is to group *multiple* hosts into
> virtual LANs.

My needs were different.  I wanted to emulate many ethernet NICs with
a single physical NIC.  For a while, I was supporting both filter-on-dest
and filter-on-source logic, but since I never used filter-on-source, the
code was rotting and I decided to remove it.

If there is interest in supporting filter-on-source as well, then
I will certainly consider patches against my patch.  And of course,
you are welcome to do a complete fork if you wish (I think that would
be a waste of effort for the most part, however.)

The old code had locking issues and module-unload issues, so we
will need to do a bit more thinking before we re-add that functionality.

> This seems to be completely unrelated now to the patch I originally
> sent to this list.  This is not a problem in itself, but I can't see
> how the functionality still relates to MAC address based VLANs....

Yes, it is quite different, but much of the logic is similar.  To
start re-adding the filter-on-source features, I think the following
is needed:

1)  Add flag to toggle filter-on-source v/s filter-on-dest.

2)  Re-add filter-on-source method to find the correct mac-vlan interface.

3)  Add global hash table to map source MACs to vlans.

4)  (Optimization to my logic):  Add global hash to map destination MAC to vlan.


-- 
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com