DeviceKit presentations

Earlier today Richard and I did a DeviceKit (the set of projects replacing HAL) presentation for some other group here at Red Hat. You can see the slides here and here.

Perhaps of interest to the GNOME community, there’s also screenshots of Palimpsest, an upcoming Disk Utility library and application for GNOME. Most of this is already available in Fedora’s development branch, dubbed Rawhide, but won’t be installed by default in Fedora 10. Right now I’m busy with PolicyKit stuff but the plan is definitely to get a gnome-disk-utility mailing list going soon and get this stuff integrated throughout GNOME (I’ve already made sure it’s easy to plug into gvfs for example).

For example, I learned the other day that my disk is failing (actually, as mjg59 pointed out, it’s wrong to use the word FAILING since it’s Old-Age. Easily fixed.). Now, it would definitely be useful to have a notification bubble indicating this. This is pretty trivial to write using the DeviceKit-disks API; just monitor the org.freedesktop.DeviceKit.Disks.Device:drive-smart-is-failing property. Of course the gnome-disk-utility libraries (there’s one at the GLib level and one at the GTK+ level) wraps this nicely. In fact the gnome-disk-utility library at the GTK+ level should probably provide the code for doing this status icon. Something to discuss. Hence why a mailing list and more community involvement in the gnome-disk-utility project is needed.

Anyway, the goal is to port the most of the Fedora desktop to use DeviceKit instead of HAL for the Fedora 11 time frame.

Resolution Independent GTK+

Got one of them big laptops where you feel tempted to use a looking glass because the pixels are so tiny? Ever feel cheated when you adjust the font size but the rest of the UI looks like crap in comparison? Or maybe ever felt dirty when hard coding pixel values in your application?

there’s also a tiny and a normal version…

Today I sent a patch to gtk-devel-list adding Resolution Independence to the GTK+ toolkit. Let’s see how that goes.

D-Bus introspection

Sure, there’s already d-feet and a similar Qt tool but for people who hate using the mouse or are allergic to X, I’ve put together this cute little hack that provides bash completion to dbus-send(1). Unfortunately it depends on the XML introspection parser from dbus-glib so it’s not straightforward to add to mainline D-Bus. Could easily go in dbus-glib though. Then again, it would be nice if libdbus included an XML introspection parser. Decisions, decisions.

Linux Plumbers Conference CFP extended!

I rarely blog these days, doing the Twitter thing instead and all. Anyway. The Call for Papers for the Linux Plumbers Conference in September in lovely Portland, Oregon has been extended until July 31st 2008. It’s a conference about the core infrastructure of Linux systems: the part of the system where userspace and the kernel interface. It’s the first conference where the focus is specifically on getting together the kernel people who work on the userspace interfaces and the userspace people who have to deal with kernel interfaces. It’s supposed to be a place where all the people doing infrastructure work sit down and talk, so that each other understands better what the requirements and needs of the other are, and where we can work towards fixing the major problems we currently have with our lower-level APIs.

I’m running the “Desktop Integration” microconf at Plumbers. I have two goals for the microconf. One is to be informative about what’s going on in the dusty hallways between the Kernel and the Free Desktop. Which I think is important at a place like Plumbers where we’re going to a lot of people working on similar problems present. The other goal is to actually try and make some headway on actual problems that require people from multiple communities working together. Such as some of the work Jon is focusing on, e.g. how to make fast-user-switching, multi-seat and terminal services Just Work(tm).

The conference is expected to sell out pretty quickly so it’s a good idea to go ahead and register for Plumbers Conference instead of procrastinating about doing it!

See you in Portland!

gnome.conf.au 2008

Am in Melbourne, VIC, Australia for linux.conf.au 2008; just gave a talk on PolicyKit, the slides are here. Only had 20 minutes so the whole thing felt a bit rushed and I didn’t get to go into much detail. Hopefully it made some sense though, otherwise checkout the design and API docs.

Politics. Mudslinging. Chocolate.

Whether Murray is right or not, I think his recent rant is rather tasteless and I agree some kind of retraction/apology is needed.

FWIW, Murray’s post certainly don’t reflect what I’ve experienced when I started participating in the GNOME project 2003-2004ish. That said, I acknowledge it may reflect what others have experienced. I don’t know. Also, I tend to stay out of politics… at least politics on that level. That said, I do appreciate others doing all this work; for a project of GNOME’s size we do need people in the foundation and some board, we need people spreading the word around GNOME, we do need to participate in standard organizations etc.

Either way, this kind of mudslinging is very unproductive for the project and everyone involved should know better. An old friend of mine once said “Can’t we just focus on the chocolate?”. This was in reaction to stupid in-company fighting and also a pun on a tv commercial from some chocolate company. The commercial involved three chocolate makers. They were making chocolate. Or rather, two of them were ranting about all sorts of non-sense and as a result they didn’t make much chocolate. At some point the third guy just had enough and he started whining. Much like me in this post.

Guys, can we please focus on the chocolate instead of all this non-sense?

Frustrated…

On Xguest, Access Control and Desktop

Dan, I think the ideas behind Xguest are nice. But your ideas about using SELinux to implement access control for users leaves much to be desired. If you think that a brutal approach of denying individual users to even access services like HAL, NetworkManager and Bluez is good, then please think again. Please realize that if you do this, the desktop experience will suddenly change. Things like networking and bluetooth applets will cease to work. The file manager will fall back to relying on /etc/mtab and /etc/fstab. I’m not sure PulseAudio will start.

The problem is that your approach is not fine grained; it’s all or nothing. And this is not really useful. For example, for NetworkManager what you want is to lock down the machine so the user can only connect to trusted networks. With e.g. trusted networks being defined as something that is defined in a file in /etc that only uid 0 can change.

I’m not sure if it’s a surprise to you, but over the past year or so I’ve been working on and off on an application-level access control mechanism (similar to various RBAC implementations but with a few innovations on top) called PolicyKit that does all this. It’s specifically designed and optimized for desktop applications but can also be useful for legacy UNIX command line apps. It puts the administrator and users back in control since it provides a way for them to gain authorizations by authenticating and also supports systems like Ubuntu that has no root password. It provides a nice user interface for human beings to manage authorizations. There’s GTK+ widgets to make it really simple to integrate into existing applications (and KDE support is underway). The list of applications that are PolicyKit enabled is growing rapidly. It’s in all the major distributions. It encourages least privilege, e.g splitting a program into privileged and non-privileged bits.

It’s not that I hate SELinux because I don’t. I think SELinux is already very useful, just look at how useful SELinux is in confining network-facing and privileged services. I also have SELinux support in PolicyKit already and I plan (with your help) to make gnome-user-share run in a dedicated SELinux context so it is authorized to punch holes in the firewall without any configuration whatsoever (today it’s totally broken since g-u-s picks a random high port number to listen on). But, Dan, frankly, I think your use of SELinux to lock down access on the desktop is misguided. It’s a bit like if all you have is a hammer, then everything looks like a nail. I feel that it’s a bit sad that that two developers, working for the same company, in the same office are trying to solve the same problems. We really ought to do better.

(Disclaimer: this post does not necessarily represent the views of my employer, Red Hat, Inc.)

Update: A few people pointed out that I sounded too confrontational in this post and maybe they’re right. As I tried (and probably failed at) to explain it’s not either/or. Surely, there’s a ton of value in using SELinux to lock down privileged mechanisms like HAL, NM, Bluez and so on. Having PolicyKit and SELinux work well together is in everyone’s best interest.