Re: CSME firmware / host coexistence - grab the CSME connection info params

[Emmanuel Grumbach <egrumbach gmail com>]

> On Sat, 2022-02-26 at 23:37 +0200, Emmanuel Grumbach via
> networkmanager-list wrote:
> > Hi,
> >
> > I'd like to get some guidance on how to continue the implementation
> > of the CSME firmware coexistence.
> > We now need to fetch the connection parameters from CSME (through the
> > kernel). There is a vendor command API in the kernel. This works
> > above the nl80211 channel.
> >
> > So should I include the header file in src/libnm-platform/wifi/nm-
> > wifi-utils-nl80211.c ?
> > OTOH, only recent kernels have this header, so what's the way to ask:
> > try to include this, if you don't have it, let's disable the feature?
> > Should I use this type of ifdef:
> > #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 27)
> > ?
> > Do you prefer to have a separate nm-wifi-utils-intel-vnd.c file since
> > it exists only as an Intel Vendor command?
> > Should I create a new handler in NMWifiUtilsClass for that purpose?
> >
> > Then, the nm core code could use the NMWifiUtilsClass to fetch the
> > data when it sees that RFKILL is asserted with the reason =
> > "OS_NOT_OWNER".
> >
> > Thanks :)
>
> Hi,
>
>
> Btw, what means "vendor" when you say "vendor command API"? It is kinda
> important to us, is that the feature can be used with an upstream
> kernel (without propritary modules -- and preferably only with upstream
> modules).

yes, vendor commands API and those APIs are upstreamed.

> Which header is this?

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/nl80211-vnd-intel.h?h=v5.17-rc6


> Usually, we want to build a version of NetworkManager that supports
> most features, regardless against which kernel (headers) it was build.
> Because, you should be able to upgrade your kernel and get the feature
> automatically. It means, we would rather fail at runtime, if kernel
> doens't support it.
> That means, we either add a fork of the header in `src/linux-headers`.
> Alternatively, if we only require a few defines, you can copy them
> directly to the source file where needed. It depends on how much is
> needed.

Ok, the header is fairly short, so I guess we can copy and fail on
runtime if the kernel doesn't support?

> If this gets fetched via nl80211, then  src/libnm-platform/wifi/nm-
> wifi-utils-nl80211.c is the right place.

Thanks!

I'll try to get some time for this. This is still sort of a side
project for me, so, things can take time...