Subject: Re: [PATCH net-next 3/3] net: Add table id from route lookup to route response

From: David Ahern <[email-masked]>
Date: Wed, 2 Sep 2015 12:51:50 -0600

On 9/2/15 12:49 PM, David Miller wrote:
> From: Thomas Graf <[email-masked]>
> Date: Wed, 2 Sep 2015 20:43:46 +0200
>
>> On 09/02/15 at 09:40am, David Ahern wrote:
>>> rt_fill_info which is called for 'route get' requests hardcodes the
>>> table id as RT_TABLE_MAIN which is not correct when multiple tables
>>> are used. Use the newly added table id in the rtable to send back
>>> the correct table.
>>>
>>> Signed-off-by: David Ahern <[email-masked]>
>>
>> What RTM_GETROUTE returns is not the actual route but a description
>> of the routing decision which is why table id, scope, protocol, and
>> prefix length are hardcoded. This is indicated by the RTM_F_CLONED
>> flag. What you propose would break userspace ABI.
>
> Agreed, I don't think we can do this.
>

Doesn't the table used to come up with the decision matter for IPv4? 
ie., hardcoding to MAIN is misleading when there is absolutely no way 
the decision comes from that table. IPv6 already returns the table id.

Or is your response that it breaks ABI and hence not going to fix.