Re: [RFC PATCH net-next 1/4] net: introduce backup_classid to struct skbuff

[Libo Chen <clbchenlibo.chen-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>]

On 2014/1/3 14:21, John Fastabend wrote:
> On 01/02/2014 09:34 PM, David Miller wrote:
>> From: Libo Chen <clbchenlibo.chen-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
>> Date: Fri, 3 Jan 2014 11:11:04 +0800
>>
>>>
>>> introduce backup_classid to struct skbuff,
>>> we can use it to backup sk_classid when net_ns switch.
>>>
>>> Signed-off-by: Libo Chen <clbchenlibo.chen-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
>>
>> Sorry, no new sk_buff members unless there is absolutely not other
>> possible implementation.
>>
>> sk_buff is too big as-is.
> 
> To get what you want fix the dev_forward_skb() call. But its
> not clear to me why you would expect the sock info to be propagated
> like this. It seems like an incorrect assumption or a misunderstanding
> somewhere. If the virtual link was a physical link you wouldn't expect
> to know anything about the senders socket.

AFAIK, once the sock is created, sock->sk_classid will be set, see sk_alloc()
so I think it is safe.

thanks,
Libo

> 
> Thanks,
> John
>