Kernel Recipes 2017 - What's inside the input stack? - Benjamain Tissoires
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The document provides an overview of input stack architecture, detailing components such as the kernel, libinput, and interaction with various devices including keyboards, mice, and touchpads. It discusses challenges faced in maintaining functionality and security of input devices, as well as notable projects like libratbag for gaming mice. The conclusion emphasizes the need for ongoing care and attention to the security aspects of input devices.
![Toolkits:
• relies on [see previous slides]
• does fancy things like gestures too](https://image.slidesharecdn.com/kr-2017-171007142613/85/Kernel-Recipes-2017-What-s-inside-the-input-stack-Benjamain-Tissoires-17-320.jpg)
Kernel Recipes 2017 - What's inside the input stack? - Benjamain Tissoires
- 1. What's inside the input stack? 🐁 Kernel Recipes 2017
- 2. About me: Benjamin Tissoires (irc: bentiss) • Software engineer at Red Hat • kernel hid-multitouch maintainer, hid core co-maintainer • also gives bad advice for the upper input stack
- 3. About the other guy: Peter Hutterer (irc: whot) • Software engineer at Red Hat • libinput maintainer • Maintainer of the X.Org input stack, and evdev, synaptics, ... drivers • (99% of the time, 'we' means him and I)
- 4. Isn't it working already?
- 6. Problem is: hardware makers can be creative
- 9. And usage is changing
- 11. Outline: • Introduction • Input architecture • Talking about a bunch of devices • A little bit about security
- 12. Everything you never wanted to know about 'how input works'
- 13. Components: • Kernel • libinput • "Wayland" or Xorg • toolkit • application
- 14. Kernel: • knows about protocols (HID, RMI4, ...) • knows about transport layer (USB, PS/2, SMBus, I2C, etc...) • talks evdev
- 15. Libinput: • because input is "easy" • relies on libevdev • does fancy things like gestures • has a global view of the input devices
- 16. Compositor (or Xorg): • loads libinput • pass incoming events to the right client
- 17. Toolkits: • relies on [see previous slides] • does fancy things like gestures too
- 18. Applications: • do something useful (hopefully)
- 19. The good, the bad and the ugly (of input devices)
- 20. Keyboards
- 21. Page left blank
- 22. Actually no... the Caps Lock LED in a TTY is broken since UTF-8 support in the kernel
- 23. Actually no... the Caps Lock LED in a TTY is broken since UTF-8 support in the kernel pro tip: add /etc/udev/rules.d/99-kbd.rules ACTION=="add", SUBSYSTEM=="leds", ENV{DEVPATH}=="*/input*::capslock", ATTR{trigger}="kbd-ctrlllock"
- 24. Mice
- 25. (for the kernel) Not much to add... .
- 26. (for the kernel) Not much to add... except libratbag
- 27. libratbag: A thing to configure gaming mice • fun project to hack on • allows for reverse engineering without the pain of breaking the kernel • supports many gaming devices: Logitech, Roccat, G-Skill, Razer (in progress)
- 28. Touchpads
- 29. Most are still using PS/2
- 30. story time: T440
- 31. story time: T440
- 32. story time: T450
- 33. story time: T450
- 34. A little bit about security (with a red background)
- 35. CVEs?: • yes, but only a few • one notable was regarding the ChromeBook injecting HID event through a web application
- 36. MouseJack
- 37. MouseJack: Congrats, your mouse is IoT ready! http://www.mousejack.com/ .
- 38. MouseJack: Congrats, your mouse is IoT ready! http://www.mousejack.com/ You have to update it
- 39. Summary: • Input architecture • some devices still need some care • security is also involved
- 40. Credits • PS/2 keyboard: CC BY Matthijs Kooijman • G600 Gaming Mouse: all rights reserved, Logitech • Lenovo X1 Carbon: CC BY-SA 2.0 Stannate • Lenovo Yoga Tablet 3 Pro: all rights reserved, Lenovo
- 42. Summary: • Input architecture • some devices still need some care • security is also involved