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• Launchpad Entry: restricted-manager-rewrite

• Packages affected: restricted-manager

Summary

We propose a new code and driver database design for restricted-manager which will make it maintainable again and also be suitable as a proper upstream project, so that other distributions can use it as well.

We review the list of existing and proposed features and create a new code architecture which will be rewritten from scratch (with reusing most of the existing code modules, of course).

Release Note

The behaviour of restricted-manager should not change in a visible way, so this should not be mentioned in the release notes.

Rationale

The original code architecture of restricted-manager was very narrow, focusing on non-free kernel drivers in a Gnome application. A lot of new features have been bolted on this original structure, such as the KDE frontend, grouping of handlers, support for firmware installation, or non-free support packages of drivers which are free by themselves. This made the code very interdependent and hard to maintain/bugfix/understand.

The current version also has a lot of Ubuntu specifics hardcoded, which renders it hard to use for other distributions without significant changes.

Use Cases

• Jon is a RedHat developer. He decides that the next Fedora release should get an easy to use frontend for installing restricted drivers. He creates a branch of restricted-manager, implements the small distro specific "OSLib" class, and has it running. Since this was so easy, he has some time to fix some bugs, which he contributes back to upstream.

• Richard does not want to provide an interface for restricted drivers in his distribution, since they are evil and from the dark side of the force. However, he needs a GUI for providing free third-party drivers which are hosted outside of his distro's repository and which are maintained separately. He calls restricted-manager in "free third-party drivers" mode. For this reason upstream renamed the project to something less focused on restricted drivers.
• Martin writes a handler for installing the Broadcom firmware on demand. Three months after releasing Hardy the download URL changes. He just sets a new URL in the central database and users can continue to get the firmware with a snap of a finger without the need to provide an SRU.

Design

• Move away from being Ubuntu specific to a proper upstream project.
• Handlers are DE agnostic, but they sometimes need to ask questions → need to call abstract UI message boxes etc.
• Application logic and UI workflow is encapsulated in an abstract UI class. This gets subclassed to implement KDE/GNOME/CLI/a noninteractive test suite implementation.
• Basic handler must not make assumptions about kernel modules, etc., since there are many device drivers which are not tied to a kernel module (e. g. sl-modem-daemon, printer drivers, file system drivers, etc.).
• As a consequence of the previous point, each driver needs to be able to decide on its own whether it is applicable on the current system. The application framework should provide common functionality like modalias reading/overriding, lsmod/lspci evaluation, (i. e. provide a list of available and enabled hardware), kernel module blacklisting, etc., which those handlers can call.
• Supports different handler types:
  • kernel module (vmware/OSS)
  • kernel module + additional magic (nvidia/ati, sl-modem-daemon)
  • kernel module + shipped firmware (ipw3945)
  • kernel module + non-shipped firmware (bcm43xx)
  • grouping (all three vmware modules, or all two dozen OSS drivers)
  • printer driver
  • Fuse implementation to support a new file system type.
• A handler knows whether it has a free or restricted driver.
• The application can be started in any of three modes:
  • Show non-free drivers only (as in Ubuntu, since we do not want to promote providing free drivers without getting them into the main kernel)
  • Show free drivers only (Richard's use case from above, there is an actual real-life request for this feature)
  • All available drivers (for vendors that want it).
  The user interface and strings change accordingly.

• Encapsulate all distro specific code in an abstract OSLib class and provide distro specific implementations in concrete subclasses. This should be the only class downstreams have to override and implement (aside from providing concrete custom handlers). As an example, the Ubuntu implementation will be aware of handling /etc/default/linux-restricted-modules-common.

• Drop the runme_as_root() madness, since it is inappropriate for other distros, makes assumptions about the authentication backend, and is only used for a corner case (enabling nvidia driver in compiz control panel, but this could run r-m through gksu itself if it wants to).

• The handler → driver mapping should not be hardcoded any more. The mapping is maintained on a central location (initially on

  http://www.drivertool.org) where all interested distros can maintain their own mapping to a distro package, URL, etc., and where distros can collaborate to maintain this database.

• For this phase, distros will ship all the available handlers by default, so that they can detect availability. In the future, it is desirable to move the handlers themselves to a central place, so that third-party vendors can provide their own. We currently do not provide a solution how to get them from that central place to the distribution. However, the new program design should not assume any tight coupling between the core code and handlers. (Note: this is already true for the current design, any package can ship a handler, at which point it becomes available in r-m.)

Implementation

Handler-Driver mapping

http://www.drivertool.org is a distribution neutral place which can be used for hosting the central mapping. This site is currently hosted privately by Jon Masters, but if traffic becomes an issue, it would need some contributions by Canonical, RedHat, and other Linux vendors which participate. However, the amount of data that gets exchanged is very small.

Any computer can do a query on this database. As an input, it provides a type/value pair, where type is 'modalias', 'PCI vendor/product ID', 'Printer manufacturer and model', etc., and the value is the respective value for that type. This ensures that

• the system is extensible to accomodate any kind of hardware identification
• the amount of data sent by the client is minimal (in particular, it does *not* send the OS vendor, version, any serial numbers, etc. for privacy reasons).

The response is a list of available entries, where each entry has the following fields:

• OS Vendor
• OS version
• set of type/value pairs

The type/value pairs can be interpreted freely for each OS vendor (distribution), but there should be some standard types like 'handler, 'module', 'url', 'packagename', 'md5sum', 'sha1sum', etc.. For Ubuntu, we additionally define the data type 'repository', which would be an URL to an apt repository.

With this design, each client always gets the full list of entries for all OS vendors. This compromise is done to avoid exposing the OS vendor and version, and other information which could be used for tracking, collecting data for security attacks (like providing an IP list of known-vulnerable OS versions); the lists are not expected to become very big, too (in the order of 50 entries, which should amount to some 5 KB).

Distribution specific handlers know by themselves which module and package they need, so for those the DB only needs to specify the handler name and information which is better maintained outside of the handler itself (like URLs which are volatile). But this design also permits writing more generic handlers which get their information (which kernel module they manage, or which additional packages to install) from the driver database.

Example 1: bcm43xx firmware

Client → DB:

module
bcm43xx

DB → Client:

Ubuntu/all
    handler BroadcomFirmwareHandler
    url http://ubuntufriends.org/firmware/bcm43xx.o
    sha1sum DEADBEEF42
SuSE/10.3
    handler Bcm43xxHandler
    package bcm43xx_firmware
    component non-free

Example 2: nVidia driver

Client → DB:

modalias
pci:v000010DEd00000098sv*sd*bc03sc*i*

DB → Client:

Ubuntu/7.10
    handler NvidiaGlxNewHandler
    repository restricted
Ubuntu/8.04
    handler http://www.ubuntu.com/drivers/handlers/8.04/NvidiaGlxHandler.py
    repository restricted
Fedora/8
    handler NvidiaGraphicsHandler
    repository http://www.fedora-nonfree.org/fedora8/

Class layout

(Dia source: restricted-manager.dia)

Collaboration with other distributions

• Contact Debian, Novell, Mandriva for joining the project, contact with

  RedHat is already established with Jon Masters.

• Create upstream product on Launchpad for trunk, invite distros to host their branches there, too (this is not a requirement, though, LP just provides a great hosting platform for bzr). (OK with Jon)
• Create two mailing lists on a vendor neutral platform (LP does not have MLs yet), for now this will happen on

  http://www.linux-foundation.org/en/Driver_Backport:

  • ML for design and code coordination between vendors. (Posting limited to members, moderated subscription, should have open archives)
  • ML as an official contact point for interested third parties which want to provide their drivers in the central DB (Free posting for all, no public archive).
• As one of the first bikeshedding discussion adventure, the ML will discuss a proper name for the project. "restricted-manager" does not suit the "free third-party drivers" use case, and is not a proper noun either. The name should not actually appear prominently in the UI, it's just the project name as appearing in Launchpad, the source code, etc. (Current candidate: "3PO" or "Threepio", suggestions welcome).

Test/Demo Plan

(TODO)

It's important that we are able to test new features, and demonstrate them to users. Use this section to describe a short plan that anybody can follow that demonstrates the feature is working. This can then be used during CD testing, and to show off after release.

This need not be added or completed until the specification is nearing beta.

Outstanding Issues

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