genode/repos/dde_linux
Josef Söntgen d4e4b8bf60 driver/wifi: rework CTRL interface manager
This commit streamlines the interaction between the Wifi::Manager
and the wpa_supplicant's CTRL interface.

As user-facing changes it alters some default settings and introduces
new features:

* Every configured network now needs to explicitly have its
  'auto_connect' (to be considered an option for joining) attribute
  set to 'true' whereas this was previously the default value if the
  attribute was not set at all.

* The 'log_level' attribute is added and configures the supplicant's
  verbosity. Valid values correspond to levels used by the supplicant
  and are as follows 'excessive', 'msgdump', 'debug', 'info', 'warning'
  and 'error'. The default value is 'error' and configures the least
  amount of verbosity.

* The 'bgscan' attribute may be used to configure the way the
  supplicant performs background-scanning to steer or rather optimize
  roaming decision within the same network. The default value is set
  to 'simple:30:-70:600'. It can be disabled by specifying an empty
  value, e.g. 'bgscan=""'.

* The 'verbose_state' attribute was removed alltogether and similar
  functionality is now coverted by 'verbose' attribute.

Implementation-wise the internals changed significantly and are
outlined in the following paragraphs.

Formerly the interaction between the manager and the supplicant
was handled in an apparent way where the internal state of each
interaction was in plain sight. This made the flow cumbersome to
follow and therefor each interaction is now confined to its own
'Action' object that encapsulates the ping-pong of commands and
responses between the manager and the supplicant. All actions are
processed in an sequential way and thus there is no longer any
need to defer pending actions depending on the interal state of
the current interaction. Configuration changes as well as events
issued by the supplicant where new actions can be created are
handled in this fashion. Of note are both signal-handlers,
'_handle_cmds' and '_handle_events' respectively.

The state report, which provides the information about the current
state of connectivity to a given wireless network, was dealt with
in the same vein and its handling was spread across the manager
implementation. Again, to make it easier to follow, the generation
of the state report is now purely driven by the 'Join_state' object.
This object encapsulates the state of connectivity and is normally
updated by events issued from the supplicant (see '_handle_events').
It is also incorporated when handling command responses (see
'_handle_cmds').

Handling of timed-actions, like scan and signal quality
update requests, was done by setting a timeout at the Timer session
directly and thus only one timed-action could be pending at any time.
This excluded dealing with timed-actions like connected-scanning
and signal quality polling concurrently. This was changed and now
a One_shot_timeout is used to programm each concurrent timed-action.

For implementing the communication channel for the CTRL interface the
manager and supplicant use a shared memory buffer, the Msg_buffer.
Since the CTRL interface for Genode was implemented using C, some
shenanigans were performed to access the memory buffer. Now the
CTRL interface implementation uses C++ and only exports the functions
required by the supplicant as C. This simplifies the usage of the
Msg_buffer and allows for removing the global functions needed for
synchronizing the Msg_buffer access as those are now part of the
object itself via the 'Notify_interface'.

Fixes #5341.
2024-10-08 09:09:22 +02:00
..
include/wifi driver/wifi: rework CTRL interface manager 2024-10-08 09:09:22 +02:00
lib driver/wifi: rework CTRL interface manager 2024-10-08 09:09:22 +02:00
patches driver/wifi: rework CTRL interface manager 2024-10-08 09:09:22 +02:00
ports driver/wifi: rework CTRL interface manager 2024-10-08 09:09:22 +02:00
recipes depot: update recipe hashes 2024-08-29 12:32:25 +02:00
run driver/wifi: rework CTRL interface manager 2024-10-08 09:09:22 +02:00
src driver/wifi: rework CTRL interface manager 2024-10-08 09:09:22 +02:00
README Rename src/drivers to src/driver 2024-06-20 12:54:30 +02:00

Device drivers ported from the Linux kernel

USB
###

Host controller
~~~~~~~~~~~~~~~

The driver will start all USB controller types a platform offers.

Please consult repos/dde_linux/driver/usb_host/README for a description.

HID
~~~

Please consult repos/dde_linux/driver/usb_hid/README for a description.

Storage
~~~~~~~

Please consult repos/os/src/driver/usb_block/README for a description.

Network (Nic)
~~~~~~~~~~~~~

Please consolut repos/dde_linux/src/driver/usb_net/README for a description.

LXIP
####

LXIP is a port of the Linux TCP/IP stack to Genode. It is build as a shared
library named 'lxip.lib.so'. The IP stack can be interfaced using Genode's
version of 'libc' by linking your application to 'lxip_libc' plugin in your
'target.mk' file.

Wifi
####

The 'wifi' driver consists of a port of the mac802.11 stack, platform-specific
drivers and the 'wpa_supplicant' to Genode.


lx_kit
######

The modular lx_kit seperates the required back end functionality of the Linux
emulation environment from the front end. Thereby each driver can reuse
specific parts or supply more suitable implementations by itself. It is used to
reduce the amount of redundant code in each driver.

The lx_kit is split into several layers whose structure is as follows:

The first layer in _repos/dde_linux/src/include/lx_emul_ contains those header
files that provide the structural definitions and function declarations of the
Linux API, e.g. _errno.h_ provides all error code values. The second layer in
_repos/dde_linux/src/include/lx_emul/impl_ contains the implementation of
selected functions, e.g. _slab.h_ provides the implementation of 'kmalloc()'.
The lx_kit back end API is the third layer and provides the _Lx::Malloc_
interface (_repos/dde_linux/src/include/lx_kit/malloc.h_) which is used to
implement 'kmalloc()'. There are several generic implementations of the lx_kit
interfaces that can be used by a driver.

A driver typically includes a 'lx_emul/impl/xyz.h' header once directly in its
lx_emul compilation unit. The lx_kit interface files are only included in those
compilation units that use or implement the interface. If a driver wants to use
a generic implementation it must add the source file to its source file list.
The generic implementations are located in _repos/dde_linux/src/lx_kit/_.

The modular lx_kit still depends on the private _lx_emul.h_ header file that is
tailored to each driver. Since the lx_kit already contains much of the
declarations and definitions that were originally placed in these private
header files, those files can now ommit a large amount of code.