Re: [RFC PATCH net-next] rtnetlink: add RTNH_F_REJECT_MASK

[David Ahern <dsahern@gmail.com>]

On 11/11/21 6:02 PM, Roopa Prabhu wrote:
> 
> On 11/11/21 2:19 PM, David Ahern wrote:
>> [ cc roopa]
>>
>> On 11/11/21 12:23 PM, Alexander Mikhalitsyn wrote:
>>> On Thu, Nov 11, 2021 at 10:13 PM David Ahern <dsahern@gmail.com> wrote:
>>>> On 11/11/21 9:02 AM, Alexander Mikhalitsyn wrote:
>>>>> diff --git a/include/uapi/linux/rtnetlink.h
>>>>> b/include/uapi/linux/rtnetlink.h
>>>>> index 5888492a5257..c15e591e5d25 100644
>>>>> --- a/include/uapi/linux/rtnetlink.h
>>>>> +++ b/include/uapi/linux/rtnetlink.h
>>>>> @@ -417,6 +417,9 @@ struct rtnexthop {
>>>>>   #define RTNH_COMPARE_MASK    (RTNH_F_DEAD | RTNH_F_LINKDOWN | \
>>>>>                                 RTNH_F_OFFLOAD | RTNH_F_TRAP)
>>>>>
>>>>> +/* these flags can't be set by the userspace */
>>>>> +#define RTNH_F_REJECT_MASK   (RTNH_F_DEAD | RTNH_F_LINKDOWN)
>>>>> +
>>>>>   /* Macros to handle hexthops */
>>>> Userspace can not set any of the flags in RTNH_COMPARE_MASK.
>>> Hi David,
>>>
>>> thanks! So, I have to prepare a patch which fixes current checks for
>>> rtnh_flags
>>> against RTNH_COMPARE_MASK. So, there is no need to introduce a separate
>>> RTNH_F_REJECT_MASK.
>>> Am I right?
>>>
>> Added Roopa to double check if Cumulus relies on this for their switchd.
>>
>> If that answer is no, then there is no need for a new mask.
>>
> 
> yes, these flags are already exposed to userspace and we do use it.
> 
> We have also considered optimizations where routing daemons set OFFLOAD
> and drivers clear it when offload fails.
> 
> I wont be surprised if other open network os distributions are also
> using it.
> 
> 
> Thanks for the headsup David.
> 

Thanks, Roopa. So then the separate mask is needed.