Re: [PATCH net-next] net: ipv6: addrconf: Add accept_ra_prefix_route.

[subashab@codeaurora.org]

On 2021-03-10 14:33, subashab@codeaurora.org wrote:
> On 2021-03-10 12:28, David Ahern wrote:
>> On 3/10/21 11:49 AM, Subash Abhinov Kasiviswanathan wrote:
>>> Added new procfs flag to toggle the automatic addition of prefix
>>> routes on a per device basis. The new flag is accept_ra_prefix_route.
>>> 
>>> A value of 0 for the flag maybe used in some forwarding scenarios
>>> when a userspace daemon is managing the routing.
>>> Manual deletion of the kernel installed route was not sufficient as
>>> kernel was adding back the route.
>>> 
>>> Defaults to 1 as to not break existing behavior.
>>> 
>>> Signed-off-by: Subash Abhinov Kasiviswanathan 
>>> <subashab@codeaurora.org>
>>> ---
>>>  Documentation/networking/ip-sysctl.rst | 10 ++++++++++
>>>  include/linux/ipv6.h                   |  1 +
>>>  include/uapi/linux/ipv6.h              |  1 +
>>>  net/ipv6/addrconf.c                    | 16 +++++++++++++---
>>>  4 files changed, 25 insertions(+), 3 deletions(-)
>>> 
>>> diff --git a/Documentation/networking/ip-sysctl.rst
>>> b/Documentation/networking/ip-sysctl.rst
>>> index c7952ac..9f0d92d 100644
>>> --- a/Documentation/networking/ip-sysctl.rst
>>> +++ b/Documentation/networking/ip-sysctl.rst
>>> @@ -2022,6 +2022,16 @@ accept_ra_mtu - BOOLEAN
>>>  		- enabled if accept_ra is enabled.
>>>  		- disabled if accept_ra is disabled.
>>> 
>>> +accept_ra_prefix_route - BOOLEAN
>>> +	Apply the prefix route based on the RA. If disabled, kernel
>>> +	does not install the route. This can be used if a userspace
>>> +	daemon is managing the routing.
>>> +
>>> +	Functional default:
>>> +
>>> +		- enabled if accept_ra_prefix_route is enabled
>>> +		- disabled if accept_ra_prefix_route is disabled
>>> +
>>>  accept_redirects - BOOLEAN
>>>  	Accept Redirects.
>>> 
>> 
>> this seems to duplicate accept_ra_pinfo
> 
> Thanks David. We will try out that entry instead and check.

We are seeing that the interface itself doesn't get the address assigned
via RA when setting accept_ra_pinfo = 0.

We would like to have the interface address assigned via SLAAC
here while the route management would be handled via the userspace 
daemon.
In that case, we do not want the kernel installed route to be present
(behavior controlled via this proc entry).