Le 25/08/2020 à 19:01, Harald Welte a écrit :
> Hi Nicolas,
>
> thanks a lot for your patch.
>
> On Tue, Aug 25, 2020 at 05:57:15PM +0200, Nicolas Dichtel wrote:
>> Like all other network functions, let's notify gtp context on creation and
>> deletion.
>
> While this may be in-line with typical kernel tunnel device practises, I am
> not
> convinced it is the right way to go for GTP.
>
> Contrary to other tunneling mechansims, GTP doesn't have a 1:1 rlationship
> between
> tunnels and netdev's. You can easily have tens of thousands - or even many
> more -
> PDP contexts (at least one per subscriber) within one "gtp0" netdev. Also,
> the state
> is highly volatile. Every time a subscriber registers/deregisters, goes in
> or out of
> coverage, in or out of airplane mode, etc. those PDP contexts go up and down.
>
> Sending (unsolicited) notifications about all of those seems quite
> heavyweight to me.
There is no 'unsolicited' notifications with this patch. Notifications are sent
only if a userspace application has subscribed to the gtp mcast group.
ip routes or conntrack entries are notified in the same way and there could a
lot of them also (more than 100k conntrack entries for example).
