RE: [PATCH v3 4/4] iwlwifi: mvm: add vendor commands needed for iwlmei

From: "Grumbach, Emmanuel" <emmanuel.grumbach@intel.com>
To: Kalle Valo <kvalo@codeaurora.org>,
	Emmanuel Grumbach <egrumbach@gmail.com>
Cc: "Coelho, Luciano" <luciano.coelho@intel.com>,
	linux-wireless <linux-wireless@vger.kernel.org>,
	"Beker, Ayala" <ayala.beker@intel.com>
Subject: RE: [PATCH v3 4/4] iwlwifi: mvm: add vendor commands needed for iwlmei
Date: Sat, 7 Aug 2021 18:34:34 +0000	[thread overview]
Message-ID: <SA0PR11MB4752D9B34C2A60B85CA3E5F3F2F49@SA0PR11MB4752.namprd11.prod.outlook.com> (raw)
In-Reply-To: <87o8acc8v1.fsf@codeaurora.org>

> > On Thu, Jun 24, 2021 at 8:13 PM Kalle Valo <kvalo@codeaurora.org> wrote:
> >>
> >> Emmanuel Grumbach <emmanuel.grumbach@intel.com> writes:
> >>
> >> > Add the vendor commands that must be used by the network manager
> to
> >> > allow proper operation of iwlmei.
> >> >
> >> > * Send information on the AP CSME is connected to
> >> > * Notify the userspace when roaming is forbidden
> >> > * Allow the userspace to require ownership
> >> >
> >> > Co-Developed-by: Ayala Beker <ayala.beker@intel.com>
> >> > Signed-off-by: Emmanuel Grumbach
> <emmanuel.grumbach@intel.com>
> >> > ---
> >> >  drivers/net/wireless/intel/iwlwifi/Kconfig    |  11 ++
> >> >  .../net/wireless/intel/iwlwifi/mvm/Makefile   |   1 +
> >> >  .../net/wireless/intel/iwlwifi/mvm/mac80211.c |   2 +
> >> >  drivers/net/wireless/intel/iwlwifi/mvm/mvm.h  |   9 +-
> >> >  .../wireless/intel/iwlwifi/mvm/vendor-cmd.c   | 186
> ++++++++++++++++++
> >> >  5 files changed, 203 insertions(+), 6 deletions(-)  create mode
> >> > 100644 drivers/net/wireless/intel/iwlwifi/mvm/vendor-cmd.c
> >> >
> >> > diff --git a/drivers/net/wireless/intel/iwlwifi/Kconfig
> >> > b/drivers/net/wireless/intel/iwlwifi/Kconfig
> >> > index 629aaa26a230..f91516d08b28 100644
> >> > --- a/drivers/net/wireless/intel/iwlwifi/Kconfig
> >> > +++ b/drivers/net/wireless/intel/iwlwifi/Kconfig
> >> > @@ -92,11 +92,22 @@ config IWLWIFI_BCAST_FILTERING
> >> >         If unsure, don't enable this option, as some programs might
> >> >         expect incoming broadcasts for their normal operations.
> >> >
> >> > +config IWLMVM_VENDOR_CMDS
> >> > +     bool "Enable vendor commands"
> >> > +     depends on IWLMVM
> >> > +     help
> >> > +       This option enables support for vendor commands, including some
> >> > +       that don't have their own Kconfig option. Other Kconfig options
> >> > +       depend on this one as well.
> >> > +
> >> > +       This is not enabled by default, if unsure, say N.
> >>
> >> Why do we need a new Kconfig option? Why not always include it in the
> >> compilation?
> >
> > I expect 99.9% of the users to want to disable this.VENDOR_CMDS adds a
> > user space API and in a sense, it increases the attack surface. You
> > can claim that I can reuse the IWLMEI Kconfig option, which is true,
> > but we have other features that need VENDOR_CMDS that are not (yet)
> > upstream. So the idea here is that any feature that needs the
> > VENDOR_CMDS will select it and if none of them are enabled (for 99.9%
> > of the use cases), then, we would disable VENDOR_CMDS and decrease
> the
> > attack surface.
> >
> > Makes sense?
> 
> How do you prevent users or distros from enabling the feature? They can be
> in a hurry, lazy or not caring and enable the feature anyway. So no, I'm not
> really buying this. If the interface is not secure it should not be in upstream, I
> think only exception to this is the nl80211 testmode interface which is for lab
> or similar use.
> 

So what do you want?
To make it depend on IWLMEI Kconfig knob and not add the VENDOR_CMDS one?
Fine.