Re: [PATCH v3 6/7] netlink: Add multicast group level permissions

[Jakub Kicinski <kuba@kernel.org>]

On Fri, 31 Mar 2023 17:48:18 +0000 Anjali Kulkarni wrote:
> > On Mar 31, 2023, at 10:24 AM, Jakub Kicinski <kuba@kernel.org> wrote:
> > On Fri, 31 Mar 2023 17:00:27 +0000 Anjali Kulkarni wrote:  
> >> Are you suggesting adding something like a new struct proto_ops for
> >> the connector family? I have not looked into that, though that would
> >> seem like a lot of work, and also I have not seen any infra structure
> >> to call into protocol specific bind from netlink bind?  
> > 
> > Where you're adding a release callback in patch 2 - there's a bind
> > callback already three lines above. What am I missing?  
> Ah yes, that one is actually meant to be used for adding(bind) and
> deleting(unbind) multicast group memberships. So it is also called
> from setsockopt() - so I think just checking for root access
> permission changes the semantics of what it is meant to be used for?
> Besides we would need to change some of that ordering there (check
> for permissions & netlink_bind call) and changing it for all users of
> netlink might not be a good idea…?

AFAICT genetlink uses that callback in the way I'm suggesting already
(see genl_bind()) so if you can spot a bug or a problem - we need to
fix it :S