Add embassy-usb-ncm. Implements USBB CDC NCM (Ethernet over USB)

1 files changed, 277 insertions, 0 deletions

diff --git a/examples/nrf/src/bin/usb_ethernet.rs b/examples/nrf/src/bin/usb_ethernet.rs
new file mode 100644
index 000000000..70460d23c
--- /dev/null
+++ b/examples/nrf/src/bin/usb_ethernet.rs
@@ -0,0 +1,277 @@
+#![no_std]
+#![no_main]
+#![feature(generic_associated_types)]
+#![feature(type_alias_impl_trait)]
+
+use core::mem;
+use core::sync::atomic::{AtomicBool, Ordering};
+use core::task::Waker;
+use defmt::*;
+use embassy::blocking_mutex::raw::ThreadModeRawMutex;
+use embassy::channel::Channel;
+use embassy::executor::Spawner;
+use embassy::io::{AsyncBufReadExt, AsyncWriteExt};
+use embassy::util::Forever;
+use embassy_net::{PacketBox, PacketBoxExt, PacketBuf, TcpSocket};
+use embassy_nrf::pac;
+use embassy_nrf::usb::Driver;
+use embassy_nrf::Peripherals;
+use embassy_nrf::{interrupt, peripherals};
+use embassy_usb::{Builder, Config, UsbDevice};
+use embassy_usb_ncm::{CdcNcmClass, Receiver, Sender, State};
+
+use defmt_rtt as _; // global logger
+use panic_probe as _;
+
+type MyDriver = Driver<'static, peripherals::USBD>;
+
+#[embassy::task]
+async fn usb_task(mut device: UsbDevice<'static, MyDriver>) -> ! {
+    device.run().await
+}
+
+#[embassy::task]
+async fn usb_ncm_rx_task(mut class: Receiver<'static, MyDriver>) {
+    loop {
+        warn!("WAITING for connection");
+        LINK_UP.store(false, Ordering::Relaxed);
+
+        class.wait_connection().await.unwrap();
+
+        warn!("Connected");
+        LINK_UP.store(true, Ordering::Relaxed);
+
+        loop {
+            let mut p = unwrap!(PacketBox::new(embassy_net::Packet::new()));
+            let n = match class.read_packet(&mut p[..]).await {
+                Ok(n) => n,
+                Err(e) => {
+                    warn!("error reading packet: {:?}", e);
+                    break;
+                }
+            };
+
+            let buf = p.slice(0..n);
+            if RX_CHANNEL.try_send(buf).is_err() {
+                warn!("Failed pushing rx'd packet to channel.");
+            }
+        }
+    }
+}
+
+#[embassy::task]
+async fn usb_ncm_tx_task(mut class: Sender<'static, MyDriver>) {
+    loop {
+        let pkt = TX_CHANNEL.recv().await;
+        if let Err(e) = class.write_packet(&pkt[..]).await {
+            warn!("Failed to TX packet: {:?}", e);
+        }
+    }
+}
+
+#[embassy::task]
+async fn net_task() -> ! {
+    embassy_net::run().await
+}
+
+#[embassy::main]
+async fn main(spawner: Spawner, p: Peripherals) {
+    let clock: pac::CLOCK = unsafe { mem::transmute(()) };
+    let power: pac::POWER = unsafe { mem::transmute(()) };
+
+    info!("Enabling ext hfosc...");
+    clock.tasks_hfclkstart.write(|w| unsafe { w.bits(1) });
+    while clock.events_hfclkstarted.read().bits() != 1 {}
+
+    info!("Waiting for vbus...");
+    while !power.usbregstatus.read().vbusdetect().is_vbus_present() {}
+    info!("vbus OK");
+
+    // Create the driver, from the HAL.
+    let irq = interrupt::take!(USBD);
+    let driver = Driver::new(p.USBD, irq);
+
+    // Create embassy-usb Config
+    let mut config = Config::new(0xc0de, 0xcafe);
+    config.manufacturer = Some("Embassy");
+    config.product = Some("USB-Ethernet example");
+    config.serial_number = Some("12345678");
+    config.max_power = 100;
+    config.max_packet_size_0 = 64;
+
+    // Required for Windows support.
+    config.composite_with_iads = true;
+    config.device_class = 0xEF;
+    config.device_sub_class = 0x02;
+    config.device_protocol = 0x01;
+
+    struct Resources {
+        device_descriptor: [u8; 256],
+        config_descriptor: [u8; 256],
+        bos_descriptor: [u8; 256],
+        control_buf: [u8; 128],
+        serial_state: State<'static>,
+    }
+    static RESOURCES: Forever<Resources> = Forever::new();
+    let res = RESOURCES.put(Resources {
+        device_descriptor: [0; 256],
+        config_descriptor: [0; 256],
+        bos_descriptor: [0; 256],
+        control_buf: [0; 128],
+        serial_state: State::new(),
+    });
+
+    // Create embassy-usb DeviceBuilder using the driver and config.
+    let mut builder = Builder::new(
+        driver,
+        config,
+        &mut res.device_descriptor,
+        &mut res.config_descriptor,
+        &mut res.bos_descriptor,
+        &mut res.control_buf,
+        None,
+    );
+
+    // WARNINGS for Android ethernet tethering:
+    // - On Pixel 4a, it refused to work on Android 11, worked on Android 12.
+    // - if the host's MAC address has the "locally-administered" bit set (bit 1 of first byte),
+    //   it doesn't work! The "Ethernet tethering" option in settings doesn't get enabled.
+    //   This is due to regex spaghetti: https://android.googlesource.com/platform/frameworks/base/+/refs/tags/android-mainline-12.0.0_r84/core/res/res/values/config.xml#417
+    //   and this nonsense in the linux kernel: https://github.com/torvalds/linux/blob/c00c5e1d157bec0ef0b0b59aa5482eb8dc7e8e49/drivers/net/usb/usbnet.c#L1751-L1757
+
+    // Our MAC addr.
+    let our_mac_addr = [0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC];
+    // Host's MAC addr. This is the MAC the host "thinks" its USB-to-ethernet adapter has.
+    let host_mac_addr = [0x88, 0x88, 0x88, 0x88, 0x88, 0x88];
+
+    // Create classes on the builder.
+    let class = CdcNcmClass::new(&mut builder, &mut res.serial_state, host_mac_addr, 64);
+
+    // Build the builder.
+    let usb = builder.build();
+
+    unwrap!(spawner.spawn(usb_task(usb)));
+
+    let (tx, rx) = class.split();
+    unwrap!(spawner.spawn(usb_ncm_rx_task(rx)));
+    unwrap!(spawner.spawn(usb_ncm_tx_task(tx)));
+
+    // Init embassy-net
+    struct NetResources {
+        resources: embassy_net::StackResources<1, 2, 8>,
+        configurator: embassy_net::DhcpConfigurator,
+        //configurator: StaticConfigurator,
+        device: Device,
+    }
+    static NET_RESOURCES: Forever<NetResources> = Forever::new();
+    let res = NET_RESOURCES.put(NetResources {
+        resources: embassy_net::StackResources::new(),
+        configurator: embassy_net::DhcpConfigurator::new(),
+        //configurator: embassy_net::StaticConfigurator::new(embassy_net::Config {
+        //    address: Ipv4Cidr::new(Ipv4Address::new(10, 42, 0, 1), 24),
+        //    dns_servers: Default::default(),
+        //    gateway: None,
+        //}),
+        device: Device {
+            mac_addr: our_mac_addr,
+        },
+    });
+    embassy_net::init(&mut res.device, &mut res.configurator, &mut res.resources);
+    unwrap!(spawner.spawn(net_task()));
+
+    // And now we can use it!
+
+    let mut rx_buffer = [0; 4096];
+    let mut tx_buffer = [0; 4096];
+    let mut buf = [0; 4096];
+
+    loop {
+        let mut socket = TcpSocket::new(&mut rx_buffer, &mut tx_buffer);
+        socket.set_timeout(Some(embassy_net::SmolDuration::from_secs(10)));
+
+        info!("Listening on TCP:1234...");
+        if let Err(e) = socket.accept(1234).await {
+            warn!("accept error: {:?}", e);
+            continue;
+        }
+
+        info!("Received connection from {:?}", socket.remote_endpoint());
+
+        loop {
+            let n = match socket.read(&mut buf).await {
+                Ok(0) => {
+                    warn!("read EOF");
+                    break;
+                }
+                Ok(n) => n,
+                Err(e) => {
+                    warn!("read error: {:?}", e);
+                    break;
+                }
+            };
+
+            info!("rxd {:02x}", &buf[..n]);
+
+            match socket.write_all(&buf[..n]).await {
+                Ok(()) => {}
+                Err(e) => {
+                    warn!("write error: {:?}", e);
+                    break;
+                }
+            };
+        }
+    }
+}
+
+static TX_CHANNEL: Channel<ThreadModeRawMutex, PacketBuf, 8> = Channel::new();
+static RX_CHANNEL: Channel<ThreadModeRawMutex, PacketBuf, 8> = Channel::new();
+static LINK_UP: AtomicBool = AtomicBool::new(false);
+
+struct Device {
+    mac_addr: [u8; 6],
+}
+
+impl embassy_net::Device for Device {
+    fn register_waker(&mut self, waker: &Waker) {
+        // loopy loopy wakey wakey
+        waker.wake_by_ref()
+    }
+
+    fn link_state(&mut self) -> embassy_net::LinkState {
+        match LINK_UP.load(Ordering::Relaxed) {
+            true => embassy_net::LinkState::Up,
+            false => embassy_net::LinkState::Down,
+        }
+    }
+
+    fn capabilities(&mut self) -> embassy_net::DeviceCapabilities {
+        let mut caps = embassy_net::DeviceCapabilities::default();
+        caps.max_transmission_unit = 1514; // 1500 IP + 14 ethernet header
+        caps.medium = embassy_net::Medium::Ethernet;
+        caps
+    }
+
+    fn is_transmit_ready(&mut self) -> bool {
+        true
+    }
+
+    fn transmit(&mut self, pkt: PacketBuf) {
+        if TX_CHANNEL.try_send(pkt).is_err() {
+            warn!("TX failed")
+        }
+    }
+
+    fn receive<'a>(&mut self) -> Option<PacketBuf> {
+        RX_CHANNEL.try_recv().ok()
+    }
+
+    fn ethernet_address(&mut self) -> [u8; 6] {
+        self.mac_addr
+    }
+}
+
+#[no_mangle]
+fn _embassy_rand(buf: &mut [u8]) {
+    // TODO
+    buf.fill(0x42)
+}