WLAN Drivers

This directory contains platform, vendor, and virtual drivers for wireless networking devices on Fuchsia.

Architecture

Fuchsia WLAN drivers separate hardware-agnostic IEEE 802.11 stack logic from hardware-specific device control. Vendor drivers bind to device transport buses (PCIe, SDIO, USB) and implement fuchsia.wlan.phy for physical device control. They also implement either the FullMAC or SoftMAC protocols for data and control.

       +---------------------------------------------+
       |   Device Management (wlandevicemonitor)     |
       +---------------------------------------------+
                              | fuchsia.wlan.phy
                              v
       +---------------------------------------------+
       |      Vendor Driver (fuchsia.wlan.phy)        |
       +---------------------------------------------+
              |                               |
              | FullMAC                       | SoftMAC
              v                               v
    +-------------------+           +-------------------+
    |      wlanif       |           |    wlansoftmac    |
    | (Platform Driver) |           | (Platform Driver) |
    +-------------------+           +-------------------+
              |                               |
              v                               v
    Vendor FullMAC Device           Vendor SoftMAC Device
    (e.g., brcmfmac)                (e.g., iwlwifi)

Platform Drivers

Platform drivers provide Fuchsia's shared bridge between higher-level stack components (SME/MLME) and vendor drivers:

• wlanif: Platform driver for FullMAC devices. Relies on device firmware to implement MLME functions and bridges fuchsia.wlan.sme to fuchsia.wlan.fullmac.
• wlansoftmac: Platform driver for SoftMAC devices. Hosts host-side MLME and SME state machines, managing frame transmission, reception, association, and authentication. Communicates with vendor SoftMAC drivers through a C++/Rust FFI bridge (lib/ffi-transport). For details on maintaining FFI bindings, see wlansoftmac/rust_driver/c-binding/README.md.

Vendor Drivers (third_party/)

Vendor drivers communicate directly with physical hardware and implement fuchsia.wlan.phy:

• third_party/intel/iwlwifi: SoftMAC driver for supported Intel PCIe wireless chipsets. Implements fuchsia.wlan.softmac. See third_party/intel/iwlwifi/README.md.
• third_party/broadcom/brcmfmac: FullMAC driver for Broadcom SDIO/PCIe wireless devices. Implements fuchsia.wlan.fullmac.
• Other vendor implementations: Additional vendor drivers (such as NXP nxpfmac or Atheros ath10k) follow the same protocol contracts.

Note: Vendor drivers expose fuchsia.wlan.phy directly to wlandevicemonitor without the legacy wlanphy platform driver.

Virtual & Simulation Drivers

• wlan-virtio-hwsim: VirtIO-based WLAN hardware simulator driver for virtual environments.
• ../testing/wlantap-driver: Virtual driver creating mock PHY and interface devices via fuchsia.wlan.tap for isolated hw-sim integration tests.

Shared Driver Libraries

• lib/: Common C++ driver utilities and logging helpers.
• lib-iwlwifi/: Shared libraries and mocks for Intel driver testing, including fake-bti and fake-object for mocking syscalls and kernel handles in unit tests.