[PATCH BlueZ v2 0/3] Add HID gamepad quirk fallback for broken SDP records

From: Pakrohk <[email protected]>

This patch series adds a modular quirk system that provides HID report
descriptor fallbacks for third-party Bluetooth gamepads with incomplete
or malformed SDP records.

Problem:
Third-party Bluetooth HID gamepads (notably TG170W / DualShock 4 v2
clones, VID:PID 054c:09cc) expose incomplete HID SDP records. BlueZ's
extract_hid_record() fails with -ENOENT, preventing HIDP registration.
The Bluetooth link is active but no /dev/input/event* device is created.
Windows and Android handle this gracefully by falling back to known HID
descriptors. BlueZ does not.

Solution:
A two-tier quirk system that activates only when SDP parsing fails for a
specifically matched device. Does not globally weaken HID parsing.

  hidp_add_connection()
    -> extract_hid_record()           // normal SDP path
      -> FAILS (-ENOENT)
    -> gamepad_quirk_apply()          // check built-in + external quirks
      -> inject fallback HID descriptor
    -> continue HIDP setup normally

Patch [1] adds HMAC-SHA256 to the internal bt_crypto library using the
kernel AF_ALG interface, following the existing cmac(aes) pattern. This
replaces the previous openssl CLI dependency.

Patch [2] adds the core quirk system: built-in quirk for TG170W/DS4 v2,
external quirk profile loader with HMAC signature verification, and the
device.c integration point.

Patch [3] adds bluez-quirkctl, a CLI tool for managing external quirk
profiles (validate, install, list, remove).

External quirk profiles are JSON files installed to
/var/lib/bluez/quirks/ with HMAC-SHA256 signatures, loaded at bluetoothd
startup. This enables community-maintained gamepad support without BlueZ
source modifications.

Testing:
  - TG170W / DualShock 4 v2 (054c:09cc): buttons, sticks, touchpad
    verified via evtest
  - Kernel creates three input devices: Wireless Controller,
    Wireless Controller Motion Sensors, Wireless Controller Touchpad
  - External profile validation, installation, loading tested end-to-end
  - Tampered profiles rejected by signature verification

---
Patch 1: src: add HMAC-SHA256 to bt_crypto using kernel AF_ALG
Patch 2: input: add HID gamepad quirk fallback for broken SDP records
Patch 3: tools: add bluez-quirkctl for managing quirk profiles

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2.49.0