| # Fuchsia Wireless Networking |
| |
| ## Introduction |
| |
| Fuchsia's wireless networking stack intends to provide a compliant non-AP station |
| implementation of IEEE Std 802.11. It supports hardware with both "full MAC" and |
| "soft MAC" firmware, in which the MLME layer of the 802.11 spec is implemented |
| in the firmware and the host OS, respectively. |
| |
| ## High-level architecture |
| |
| ``` |
| +------------------+ +------------------+ |
| Fuchsia service | Fuchsia netstack | | Fuchsia Wireless | |
| | | | Network Service | |
| +------------------+ +------------------+ |
| ^ ^ ^ |
| | | | |
| fdio/FIDL ------|------------------------|----------------|------------------- |
| | | | |
| v | v |
| +------------------+ | +--------------+ |
| | Fuchsia ethernet |<--------|-------------->| Fuchsia WLAN | |
| | driver | | | MLME driver | |
| devmgr +------------------+ | +--------------+ |
| ^ | ^ |
| | | | |
| v v v |
| +-------------------+ +-------------------+ |
| | Driver | | Driver | |
| | (Full MAC device) | | (Soft MAC device) | |
| +-------------------+ +-------------------+ |
| ^ ^ |
| \ / |
| hardware bus --------------------\----------------/------------------ |
| (USB, PCI, etc) \ / |
| v v |
| +---------------------+ |
| | Wireless networking | |
| hardware | hardware | |
| +---------------------+ |
| ``` |
| |
| |
| ## Drivers |
| |
| A Full MAC driver relies on the firmware in the wireless hardware to implement |
| the majority of the IEEE 802.11 MLME functions. |
| |
| A Soft MAC driver implements the basic building blocks of communication with the |
| wireless hardware in order to allow the Fuchsia MLME driver to execute the IEEE |
| 802.11 MLME functions. |
| |
| The Fuchsia MLME driver is a hardware-independent layer that provides state |
| machines for synchronization, authentication, association, and other wireless |
| networking state. It communicates with a Soft MAC driver to manage the hardware. |
| |
| ## WLAN service |
| |
| The Fuchsia Wireless Network Service implements the IEEE 802.11 SME functions |
| and holds state about all the wireless networks that are available in the |
| current environment. It is the interface to the hardware (via the drivers) used |
| by components like System UI. |
| |
| ## Relation to the Ethernet stack |
| |
| Either a Full MAC driver or the Fuchsia WLAN MLME driver will expose an Ethernet |
| device in devmgr. This device will behave as any other Ethernet device, and will |
| provide data packets to the rest of the system. TBD: whether to use Ethernet II |
| frames always, or support 802.2 SNAP frames. |
| |
| ## Interfaces |
| |
| The Fuchsia Wireless Network Service will communicate with each hardware device |
| using a channel to the driver, obtained via ioctl. (Eventually this will be |
| replaced by FIDL.) Messages exchanged over this channel will encode the |
| request/response for each action, generally following the IEEE 802.11 MLME SAP |
| definitions. |
| |
| For Soft MAC devices, the hardware driver and the generic MLME driver will |
| communicate in-process using a DDK "protocol" for wlan devices. Primitives |
| exposed through this interface include send, receive, and setting the radio |
| channel. |
