Re: [Qemu-devel] [PATCH v11 02/12] init/cleanup of netfilter object

[Yang Hongyang <yanghy@cn.fujitsu.com>]

Hi Eric,

On 09/17/2015 05:09 AM, Eric Blake wrote:
> On 09/16/2015 06:15 AM, Yang Hongyang wrote:
>> Add a netfilter object based on QOM.
>>
>> A netfilter is attached to a netdev, captures all network packets
>> that pass through the netdev. When we delete the netdev, we also
>> delete the netfilter object attached to it, because if the netdev is
>> removed, the filter which attached to it is useless.
>>
>> QTAILQ_ENTRY next used by netdev, filter belongs to the specific netdev is
>> in this queue.
>>
>> Also init delayed object after net_init_clients, because netfilters need
>> to be initialized after net clients initialized.
>>
>> Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
>> ---
>
> Interface review:
>
>> +++ b/qapi-schema.json
>> @@ -2551,6 +2551,24 @@
>>       'opts': 'NetClientOptions' } }
>>
>>   ##
>> +# @NetFilterChain
>> +#
>> +# netfilter chain, a netfilter is attached to a netdev, captures the
>> +# network packets of the netdev.
>
> Grammar. Maybe:
>
> This enum describes which packets are being tracked by a netfilter chain
> attached as a filter to a netdev object.

Thanks!

>
>> +#
>> +# @all: the filter will receive packets both sent to/from the netdev, this
>> +#       is the default chain.
>> +#
>> +# @in: the filter will receive packets sent to the netdev.
>> +#
>> +# @out: the filter will receive packets sent from the netdev.
>> +#
>> +# Since 2.5
>> +##
>> +{ 'enum': 'NetFilterChain',
>> +  'data': [ 'all', 'in', 'out' ] }
>
> I don't see any other QMP usage of this enum anywhere in the series. Are
> you planning on supporting QMP?  If so, let's get that design discussion
> started.  If not, why not?

This series is based on QOM, so the QMP command for object_add
will use this enum, for example:
   1 { "execute": "qmp_capabilities" }
   2 { "execute": "object-add",
   3              "arguments": { "qom-type": "filter-buffer",
   4                             "id": "f0",
   5                             "props": { "netdev": "bn0",
   6                                        "chain": "in",
   7                                        "interval": 2000 } } }

for hmp:
object_add filter-buffer,id=f0,netdev=bn0,chain=in,interval=1000

command options:
-object filter-buffer,id=f0,netdev=bn0,chain=in,interval=1000

>
> In particular, you may want to base things on top of my work to make QMP
> 'netdev_add' a full-fledged introspectible command (still pending some
> qapi commits landing upstream):
>
> https://lists.gnu.org/archive/html/qemu-devel/2015-09/msg02602.html
>

-- 
Thanks,
Yang.