[libvirt] [PATCH 1/2] nwfilter: Pass the VM's UUID into the nwfilter subsystem

[Stefan Berger]

On 12/08/2011 06:32 PM, Eric Blake wrote:
> On 11/28/2011 11:32 AM, Stefan Berger wrote:
>> A preparatory patch for DHCP snooping where we want to be able to
>> differentiate between a VM's interface using the tuple of
>> <VM UUID, Interface MAC address>. We assume that MAC addresses could
>> possibly be re-used between different networks (VLANs) thus do not only
>> want to rely on the MAC address to identify an interface.
>>
>> At the current 'final destination' in virNWFilterInstantiate I am leaving
>> the vmuuid parameter as ATTRIBUTE_UNUSED until the DHCP snooping patches arrive.
>> (we may not post the DHCP snooping patches for 0.9.8, though)
> You may want to tweak the commit message, now that 0.9.8 is out :)
>
>> Mostly this is a pretty trivial patch. On the lowest layers, in lxc_driver
>> and uml_conf, I am passing the virDomainDefPtr around until I am passing
>> only the VM's uuid into the NWFilter calls.
> This patch applied cleanly after your return status cleanup, and does
> indeed look straight-forward.
>
>> ---
>>   src/conf/domain_nwfilter.c             |    3 ++-
>>   src/conf/domain_nwfilter.h             |    2 ++
>>   src/lxc/lxc_driver.c                   |    5 ++++-
>>   src/nwfilter/nwfilter_driver.c         |    6 ++++--
>>   src/nwfilter/nwfilter_gentech_driver.c |   27 +++++++++++++++++++--------
>>   src/nwfilter/nwfilter_gentech_driver.h |    5 ++++-
>>   src/nwfilter/nwfilter_learnipaddr.c    |    3 ++-
>>   src/qemu/qemu_command.c                |    2 +-
>>   src/qemu/qemu_process.c                |    2 +-
>>   src/uml/uml_conf.c                     |   11 +++++++----
>>   10 files changed, 46 insertions(+), 20 deletions(-)
>>
>> Index: libvirt-acl/src/nwfilter/nwfilter_learnipaddr.c
>> ===================================================================
>> --- libvirt-acl.orig/src/nwfilter/nwfilter_learnipaddr.c
>> +++ libvirt-acl/src/nwfilter/nwfilter_learnipaddr.c
>> @@ -704,7 +704,8 @@ learnIPAddressThread(void *arg)
>>                             "cache for interface %s"), inetaddr, req->ifname);
>>               }
>>
>> -            ret = virNWFilterInstantiateFilterLate(req->ifname,
>> +            ret = virNWFilterInstantiateFilterLate(NULL,
>> +                                                   req->ifname,
> Is this going to bite us later?  Obviously, with the ATTRIBUTE_UNUSED in
It shouldn't. The DHCP snooping code is the final recipient of the UUID. 
If the above filter instantiation function was to call into the DHCP 
snooping code we'd have a different type of problem.
> this patch, it won't, but I'm wondering if you need to pass the uuid
> through a few more calls (but that can be a separate patch).
> ACK.
>
Thanks for the review.

     Stefan