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lib.rs
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lib.rs
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#![no_std]
#![doc = include_str!("../README.md")]
#![warn(missing_docs)]
// must go first!
mod fmt;
use core::cell::RefCell;
use core::mem::MaybeUninit;
use core::task::{Context, Poll};
pub use embassy_net_driver as driver;
use embassy_net_driver::{Capabilities, LinkState};
use embassy_sync::blocking_mutex::raw::NoopRawMutex;
use embassy_sync::blocking_mutex::Mutex;
use embassy_sync::waitqueue::WakerRegistration;
use embassy_sync::zerocopy_channel;
/// Channel state.
///
/// Holds a buffer of packets with size MTU, for both TX and RX.
pub struct State<const MTU: usize, const N_RX: usize, const N_TX: usize> {
rx: [PacketBuf<MTU>; N_RX],
tx: [PacketBuf<MTU>; N_TX],
inner: MaybeUninit<StateInner<'static, MTU>>,
}
impl<const MTU: usize, const N_RX: usize, const N_TX: usize> State<MTU, N_RX, N_TX> {
const NEW_PACKET: PacketBuf<MTU> = PacketBuf::new();
/// Create a new channel state.
pub const fn new() -> Self {
Self {
rx: [Self::NEW_PACKET; N_RX],
tx: [Self::NEW_PACKET; N_TX],
inner: MaybeUninit::uninit(),
}
}
}
struct StateInner<'d, const MTU: usize> {
rx: zerocopy_channel::Channel<'d, NoopRawMutex, PacketBuf<MTU>>,
tx: zerocopy_channel::Channel<'d, NoopRawMutex, PacketBuf<MTU>>,
shared: Mutex<NoopRawMutex, RefCell<Shared>>,
}
struct Shared {
link_state: LinkState,
waker: WakerRegistration,
hardware_address: driver::HardwareAddress,
}
/// Channel runner.
///
/// Holds the shared state and the lower end of channels for inbound and outbound packets.
pub struct Runner<'d, const MTU: usize> {
tx_chan: zerocopy_channel::Receiver<'d, NoopRawMutex, PacketBuf<MTU>>,
rx_chan: zerocopy_channel::Sender<'d, NoopRawMutex, PacketBuf<MTU>>,
shared: &'d Mutex<NoopRawMutex, RefCell<Shared>>,
}
/// State runner.
///
/// Holds the shared state of the channel such as link state.
#[derive(Clone, Copy)]
pub struct StateRunner<'d> {
shared: &'d Mutex<NoopRawMutex, RefCell<Shared>>,
}
/// RX runner.
///
/// Holds the lower end of the channel for passing inbound packets up the stack.
pub struct RxRunner<'d, const MTU: usize> {
rx_chan: zerocopy_channel::Sender<'d, NoopRawMutex, PacketBuf<MTU>>,
}
/// TX runner.
///
/// Holds the lower end of the channel for passing outbound packets down the stack.
pub struct TxRunner<'d, const MTU: usize> {
tx_chan: zerocopy_channel::Receiver<'d, NoopRawMutex, PacketBuf<MTU>>,
}
impl<'d, const MTU: usize> Runner<'d, MTU> {
/// Split the runner into separate runners for controlling state, rx and tx.
pub fn split(self) -> (StateRunner<'d>, RxRunner<'d, MTU>, TxRunner<'d, MTU>) {
(
StateRunner { shared: self.shared },
RxRunner { rx_chan: self.rx_chan },
TxRunner { tx_chan: self.tx_chan },
)
}
/// Split the runner into separate runners for controlling state, rx and tx borrowing the underlying state.
pub fn borrow_split(&mut self) -> (StateRunner<'_>, RxRunner<'_, MTU>, TxRunner<'_, MTU>) {
(
StateRunner { shared: self.shared },
RxRunner {
rx_chan: self.rx_chan.borrow(),
},
TxRunner {
tx_chan: self.tx_chan.borrow(),
},
)
}
/// Create a state runner sharing the state channel.
pub fn state_runner(&self) -> StateRunner<'d> {
StateRunner { shared: self.shared }
}
/// Set the link state.
pub fn set_link_state(&mut self, state: LinkState) {
self.shared.lock(|s| {
let s = &mut *s.borrow_mut();
s.link_state = state;
s.waker.wake();
});
}
/// Set the hardware address.
pub fn set_hardware_address(&mut self, address: driver::HardwareAddress) {
self.shared.lock(|s| {
let s = &mut *s.borrow_mut();
s.hardware_address = address;
s.waker.wake();
});
}
/// Wait until there is space for more inbound packets and return a slice they can be copied into.
pub async fn rx_buf(&mut self) -> &mut [u8] {
let p = self.rx_chan.send().await;
&mut p.buf
}
/// Check if there is space for more inbound packets right now.
pub fn try_rx_buf(&mut self) -> Option<&mut [u8]> {
let p = self.rx_chan.try_send()?;
Some(&mut p.buf)
}
/// Polling the inbound channel if there is space for packets.
pub fn poll_rx_buf(&mut self, cx: &mut Context) -> Poll<&mut [u8]> {
match self.rx_chan.poll_send(cx) {
Poll::Ready(p) => Poll::Ready(&mut p.buf),
Poll::Pending => Poll::Pending,
}
}
/// Mark packet of len bytes as pushed to the inbound channel.
pub fn rx_done(&mut self, len: usize) {
let p = self.rx_chan.try_send().unwrap();
p.len = len;
self.rx_chan.send_done();
}
/// Wait until there is space for more outbound packets and return a slice they can be copied into.
pub async fn tx_buf(&mut self) -> &mut [u8] {
let p = self.tx_chan.receive().await;
&mut p.buf[..p.len]
}
/// Check if there is space for more outbound packets right now.
pub fn try_tx_buf(&mut self) -> Option<&mut [u8]> {
let p = self.tx_chan.try_receive()?;
Some(&mut p.buf[..p.len])
}
/// Polling the outbound channel if there is space for packets.
pub fn poll_tx_buf(&mut self, cx: &mut Context) -> Poll<&mut [u8]> {
match self.tx_chan.poll_receive(cx) {
Poll::Ready(p) => Poll::Ready(&mut p.buf[..p.len]),
Poll::Pending => Poll::Pending,
}
}
/// Mark outbound packet as copied.
pub fn tx_done(&mut self) {
self.tx_chan.receive_done();
}
}
impl<'d> StateRunner<'d> {
/// Set link state.
pub fn set_link_state(&self, state: LinkState) {
self.shared.lock(|s| {
let s = &mut *s.borrow_mut();
s.link_state = state;
s.waker.wake();
});
}
/// Set the hardware address.
pub fn set_hardware_address(&self, address: driver::HardwareAddress) {
self.shared.lock(|s| {
let s = &mut *s.borrow_mut();
s.hardware_address = address;
s.waker.wake();
});
}
}
impl<'d, const MTU: usize> RxRunner<'d, MTU> {
/// Wait until there is space for more inbound packets and return a slice they can be copied into.
pub async fn rx_buf(&mut self) -> &mut [u8] {
let p = self.rx_chan.send().await;
&mut p.buf
}
/// Check if there is space for more inbound packets right now.
pub fn try_rx_buf(&mut self) -> Option<&mut [u8]> {
let p = self.rx_chan.try_send()?;
Some(&mut p.buf)
}
/// Polling the inbound channel if there is space for packets.
pub fn poll_rx_buf(&mut self, cx: &mut Context) -> Poll<&mut [u8]> {
match self.rx_chan.poll_send(cx) {
Poll::Ready(p) => Poll::Ready(&mut p.buf),
Poll::Pending => Poll::Pending,
}
}
/// Mark packet of len bytes as pushed to the inbound channel.
pub fn rx_done(&mut self, len: usize) {
let p = self.rx_chan.try_send().unwrap();
p.len = len;
self.rx_chan.send_done();
}
}
impl<'d, const MTU: usize> TxRunner<'d, MTU> {
/// Wait until there is space for more outbound packets and return a slice they can be copied into.
pub async fn tx_buf(&mut self) -> &mut [u8] {
let p = self.tx_chan.receive().await;
&mut p.buf[..p.len]
}
/// Check if there is space for more outbound packets right now.
pub fn try_tx_buf(&mut self) -> Option<&mut [u8]> {
let p = self.tx_chan.try_receive()?;
Some(&mut p.buf[..p.len])
}
/// Polling the outbound channel if there is space for packets.
pub fn poll_tx_buf(&mut self, cx: &mut Context) -> Poll<&mut [u8]> {
match self.tx_chan.poll_receive(cx) {
Poll::Ready(p) => Poll::Ready(&mut p.buf[..p.len]),
Poll::Pending => Poll::Pending,
}
}
/// Mark outbound packet as copied.
pub fn tx_done(&mut self) {
self.tx_chan.receive_done();
}
}
/// Create a channel.
///
/// Returns a pair of handles for interfacing with the peripheral and the networking stack.
///
/// The runner is interfacing with the peripheral at the lower part of the stack.
/// The device is interfacing with the networking stack on the layer above.
pub fn new<'d, const MTU: usize, const N_RX: usize, const N_TX: usize>(
state: &'d mut State<MTU, N_RX, N_TX>,
hardware_address: driver::HardwareAddress,
) -> (Runner<'d, MTU>, Device<'d, MTU>) {
let mut caps = Capabilities::default();
caps.max_transmission_unit = MTU;
// safety: this is a self-referential struct, however:
// - it can't move while the `'d` borrow is active.
// - when the borrow ends, the dangling references inside the MaybeUninit will never be used again.
let state_uninit: *mut MaybeUninit<StateInner<'d, MTU>> =
(&mut state.inner as *mut MaybeUninit<StateInner<'static, MTU>>).cast();
let state = unsafe { &mut *state_uninit }.write(StateInner {
rx: zerocopy_channel::Channel::new(&mut state.rx[..]),
tx: zerocopy_channel::Channel::new(&mut state.tx[..]),
shared: Mutex::new(RefCell::new(Shared {
link_state: LinkState::Down,
hardware_address,
waker: WakerRegistration::new(),
})),
});
let (rx_sender, rx_receiver) = state.rx.split();
let (tx_sender, tx_receiver) = state.tx.split();
(
Runner {
tx_chan: tx_receiver,
rx_chan: rx_sender,
shared: &state.shared,
},
Device {
caps,
shared: &state.shared,
rx: rx_receiver,
tx: tx_sender,
},
)
}
/// Represents a packet of size MTU.
pub struct PacketBuf<const MTU: usize> {
len: usize,
buf: [u8; MTU],
}
impl<const MTU: usize> PacketBuf<MTU> {
/// Create a new packet buffer.
pub const fn new() -> Self {
Self { len: 0, buf: [0; MTU] }
}
}
/// Channel device.
///
/// Holds the shared state and upper end of channels for inbound and outbound packets.
pub struct Device<'d, const MTU: usize> {
rx: zerocopy_channel::Receiver<'d, NoopRawMutex, PacketBuf<MTU>>,
tx: zerocopy_channel::Sender<'d, NoopRawMutex, PacketBuf<MTU>>,
shared: &'d Mutex<NoopRawMutex, RefCell<Shared>>,
caps: Capabilities,
}
impl<'d, const MTU: usize> embassy_net_driver::Driver for Device<'d, MTU> {
type RxToken<'a> = RxToken<'a, MTU> where Self: 'a ;
type TxToken<'a> = TxToken<'a, MTU> where Self: 'a ;
fn receive(&mut self, cx: &mut Context) -> Option<(Self::RxToken<'_>, Self::TxToken<'_>)> {
if self.rx.poll_receive(cx).is_ready() && self.tx.poll_send(cx).is_ready() {
Some((RxToken { rx: self.rx.borrow() }, TxToken { tx: self.tx.borrow() }))
} else {
None
}
}
/// Construct a transmit token.
fn transmit(&mut self, cx: &mut Context) -> Option<Self::TxToken<'_>> {
if self.tx.poll_send(cx).is_ready() {
Some(TxToken { tx: self.tx.borrow() })
} else {
None
}
}
/// Get a description of device capabilities.
fn capabilities(&self) -> Capabilities {
self.caps.clone()
}
fn hardware_address(&self) -> driver::HardwareAddress {
self.shared.lock(|s| s.borrow().hardware_address)
}
fn link_state(&mut self, cx: &mut Context) -> LinkState {
self.shared.lock(|s| {
let s = &mut *s.borrow_mut();
s.waker.register(cx.waker());
s.link_state
})
}
}
/// A rx token.
///
/// Holds inbound receive channel and interfaces with embassy-net-driver.
pub struct RxToken<'a, const MTU: usize> {
rx: zerocopy_channel::Receiver<'a, NoopRawMutex, PacketBuf<MTU>>,
}
impl<'a, const MTU: usize> embassy_net_driver::RxToken for RxToken<'a, MTU> {
fn consume<R, F>(mut self, f: F) -> R
where
F: FnOnce(&mut [u8]) -> R,
{
// NOTE(unwrap): we checked the queue wasn't full when creating the token.
let pkt = unwrap!(self.rx.try_receive());
let r = f(&mut pkt.buf[..pkt.len]);
self.rx.receive_done();
r
}
}
/// A tx token.
///
/// Holds outbound transmit channel and interfaces with embassy-net-driver.
pub struct TxToken<'a, const MTU: usize> {
tx: zerocopy_channel::Sender<'a, NoopRawMutex, PacketBuf<MTU>>,
}
impl<'a, const MTU: usize> embassy_net_driver::TxToken for TxToken<'a, MTU> {
fn consume<R, F>(mut self, len: usize, f: F) -> R
where
F: FnOnce(&mut [u8]) -> R,
{
// NOTE(unwrap): we checked the queue wasn't full when creating the token.
let pkt = unwrap!(self.tx.try_send());
let r = f(&mut pkt.buf[..len]);
pkt.len = len;
self.tx.send_done();
r
}
}