Re: [PATCH iproute2] ip route: get: only set RTM_F_LOOKUP_TABLE flag for IPv4

[David Ahern <dsahern@gmail.com>]

On 1/21/19 12:32 AM, Ido Schimmel wrote:
> On Mon, Jan 14, 2019 at 09:29:51AM -0700, David Ahern wrote:
>> On 1/14/19 9:05 AM, Stephen Hemminger wrote:
>>> On Sat, 12 Jan 2019 12:54:06 -0800
>>> Jakub Kicinski <jakub.kicinski@netronome.com> wrote:
>>>
>>>> Kernel ignores the RTM_F_LOOKUP_TABLE flag for all families
>>>> but IPv4.  Don't set it, otherwise it may fall foul of
>>>> strict checking policies.
>>>>
>>>> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
>>>
>>> Doing the right thing is a good idea, but really I can't see
>>> the point of doing this. The kernel will always have to accept
>>> requests from older versions of iproute2 (it can never be stricter)
>>> because of ABI compatibility. So unless you can make a stronger
>>> case for this; no not applying it.
>>>
>>
>> iproute2 is often used as a reference model for features. Making
>> iproute2 correct is the right thing to do regardless of whether what the
>> kernel accepts.
>>
>> Current master branch is the first iproute2 to use the strict checking,
>> and its first release with strict checking should have as many of these
>> little one offs as possible fixed.
> 
> With current iproute2-next and net-next I get:
> 
> $ ip -6 route get 2001:db8:1::2
> Error: ipv6: Invalid flags for get route request.
> 
> Are we going to patch the kernel to accept a flag it is not using or are
> we going to patch iproute2 to not send it?
> 

iproute2 (master should have the problem too) should not send the flag
for IPv6. Stephen should apply Jakub's patch and I can merge branches.