Re: [PATCH] drivers: connector: cn_proc: allow limiting certain messages

From: Daniel Walker (danielwa)
Date: Mon Feb 17 2020 - 12:52:20 EST

On Mon, Feb 17, 2020 at 08:44:35PM +0300, Evgeniy Polyakov wrote:
> Hi Daniel, David
> 17.02.2020, 20:26, "Daniel Walker (danielwa)" <danielwa@xxxxxxxxx>:
> > On Sun, Feb 16, 2020 at 06:44:43PM -0800, David Miller wrote:
> >> This is a netlink based facility, therefore please you should add
> filtering
> >> capabilities to the netlink configuration and communications path.
> >>
> >> Module parameters are quite verboten.
> >
> > How about adding in Kconfig options to limit the types of messages? The
> issue
> > with this interface is that it's very easy for someone to enable the
> interface
> > as a listener, then never turn the interface off. Then it becomes a
> broadcast
> > interface. It's desirable to limit the more noisy messages in some
> cases.
> Compile-time options are binary switches which live forever after kernel
> config has been created, its not gonna help those who enabled messages.
> Kernel modules are kind of no-go, since it requires reboot to change in
> some cases.
> Having netlink control from userspace is a nice option, and connector has
> simple userspace->kernelspace channel,
> but it requires additional userspace utils or programming, which is still
> cumbersome.
> What about sysfs interface with one file per message type?

You mean similar to the module parameters I've done, but thru sysfs ? It would
work for Cisco. I kind of like Kconfig because it also reduces kernel size for
messages you may never want to see.