1 files changed, 212 insertions, 0 deletions

diff --git a/embassy-net/src/stack.rs b/embassy-net/src/stack.rs
new file mode 100644
index 000000000..c353f1bb1
--- /dev/null
+++ b/embassy-net/src/stack.rs
@@ -0,0 +1,212 @@
+use core::future::Future;
+use core::task::Context;
+use core::task::Poll;
+use core::{cell::RefCell, future};
+use embassy::time::{Instant, Timer};
+use embassy::util::ThreadModeMutex;
+use embassy::util::{Forever, WakerRegistration};
+use futures::pin_mut;
+use smoltcp::iface::{InterfaceBuilder, Neighbor, NeighborCache, Route, Routes};
+use smoltcp::phy::Device as _;
+use smoltcp::phy::Medium;
+use smoltcp::socket::SocketSetItem;
+use smoltcp::time::Instant as SmolInstant;
+use smoltcp::wire::{EthernetAddress, IpAddress, IpCidr, Ipv4Address};
+
+use crate::device::{Device, DeviceAdapter};
+use crate::fmt::*;
+use crate::{
+    config::{Config, Configurator},
+    device::LinkState,
+};
+use crate::{Interface, SocketSet};
+
+const ADDRESSES_LEN: usize = 1;
+const NEIGHBOR_CACHE_LEN: usize = 8;
+const SOCKETS_LEN: usize = 2;
+const LOCAL_PORT_MIN: u16 = 1025;
+const LOCAL_PORT_MAX: u16 = 65535;
+
+struct StackResources {
+    addresses: [IpCidr; ADDRESSES_LEN],
+    neighbor_cache: [Option<(IpAddress, Neighbor)>; NEIGHBOR_CACHE_LEN],
+    sockets: [Option<SocketSetItem<'static>>; SOCKETS_LEN],
+    routes: [Option<(IpCidr, Route)>; 1],
+}
+
+static STACK_RESOURCES: Forever<StackResources> = Forever::new();
+static STACK: ThreadModeMutex<RefCell<Option<Stack>>> = ThreadModeMutex::new(RefCell::new(None));
+
+pub(crate) struct Stack {
+    iface: Interface,
+    pub sockets: SocketSet,
+    link_up: bool,
+    next_local_port: u16,
+    configurator: &'static mut dyn Configurator,
+    waker: WakerRegistration,
+}
+
+impl Stack {
+    pub(crate) fn with<R>(f: impl FnOnce(&mut Stack) -> R) -> R {
+        let mut stack = STACK.borrow().borrow_mut();
+        let stack = stack.as_mut().unwrap();
+        f(stack)
+    }
+
+    pub fn get_local_port(&mut self) -> u16 {
+        let res = self.next_local_port;
+        self.next_local_port = if res >= LOCAL_PORT_MAX {
+            LOCAL_PORT_MIN
+        } else {
+            res + 1
+        };
+        res
+    }
+
+    pub(crate) fn wake(&mut self) {
+        self.waker.wake()
+    }
+
+    fn poll_configurator(&mut self, timestamp: SmolInstant) {
+        if let Some(config) = self
+            .configurator
+            .poll(&mut self.iface, &mut self.sockets, timestamp)
+        {
+            let medium = self.iface.device().capabilities().medium;
+
+            let (addr, gateway) = match config {
+                Config::Up(config) => (config.address.into(), Some(config.gateway)),
+                Config::Down => (IpCidr::new(Ipv4Address::UNSPECIFIED.into(), 32), None),
+            };
+
+            self.iface.update_ip_addrs(|addrs| {
+                let curr_addr = &mut addrs[0];
+                if *curr_addr != addr {
+                    info!("IPv4 address: {:?} -> {:?}", *curr_addr, addr);
+                    *curr_addr = addr;
+                }
+            });
+
+            if medium == Medium::Ethernet {
+                self.iface.routes_mut().update(|r| {
+                    let cidr = IpCidr::new(IpAddress::v4(0, 0, 0, 0), 0);
+                    let curr_gateway = r.get(&cidr).map(|r| r.via_router);
+
+                    if curr_gateway != gateway.map(|a| a.into()) {
+                        info!("IPv4 gateway: {:?} -> {:?}", curr_gateway, gateway);
+                        if let Some(gateway) = gateway {
+                            r.insert(cidr, Route::new_ipv4_gateway(gateway)).unwrap();
+                        } else {
+                            r.remove(&cidr);
+                        }
+                    }
+                });
+            }
+        }
+    }
+
+    fn poll(&mut self, cx: &mut Context<'_>) {
+        self.iface.device_mut().device.register_waker(cx.waker());
+        self.waker.register(cx.waker());
+
+        let timestamp = instant_to_smoltcp(Instant::now());
+        if let Err(e) = self.iface.poll(&mut self.sockets, timestamp) {
+            // If poll() returns error, it may not be done yet, so poll again later.
+            cx.waker().wake_by_ref();
+            return;
+        }
+
+        // Update link up
+        let old_link_up = self.link_up;
+        self.link_up = self.iface.device_mut().device.link_state() == LinkState::Up;
+
+        // Print when changed
+        if old_link_up != self.link_up {
+            if self.link_up {
+                info!("Link up!");
+            } else {
+                info!("Link down!");
+            }
+        }
+
+        if old_link_up || self.link_up {
+            self.poll_configurator(timestamp)
+        }
+
+        if let Some(poll_at) = self.iface.poll_at(&mut self.sockets, timestamp) {
+            let t = Timer::at(instant_from_smoltcp(poll_at));
+            pin_mut!(t);
+            if t.poll(cx).is_ready() {
+                cx.waker().wake_by_ref();
+            }
+        }
+    }
+}
+
+/// Initialize embassy_net.
+/// This function must be called from thread mode.
+pub fn init(device: &'static mut dyn Device, configurator: &'static mut dyn Configurator) {
+    let res = STACK_RESOURCES.put(StackResources {
+        addresses: [IpCidr::new(Ipv4Address::UNSPECIFIED.into(), 32)],
+        neighbor_cache: [None; NEIGHBOR_CACHE_LEN],
+        sockets: [None; SOCKETS_LEN],
+        routes: [None; 1],
+    });
+
+    let ethernet_addr = EthernetAddress([0x02, 0x02, 0x02, 0x02, 0x02, 0x02]);
+
+    let medium = device.capabilities().medium;
+
+    let mut b = InterfaceBuilder::new(DeviceAdapter::new(device));
+    b = b.ip_addrs(&mut res.addresses[..]);
+
+    if medium == Medium::Ethernet {
+        b = b.ethernet_addr(ethernet_addr);
+        b = b.neighbor_cache(NeighborCache::new(&mut res.neighbor_cache[..]));
+        b = b.routes(Routes::new(&mut res.routes[..]));
+    }
+
+    let iface = b.finalize();
+
+    let sockets = SocketSet::new(&mut res.sockets[..]);
+
+    let local_port = loop {
+        let mut res = [0u8; 2];
+        embassy::rand::rand(&mut res);
+        let port = u16::from_le_bytes(res);
+        if port >= LOCAL_PORT_MIN && port <= LOCAL_PORT_MAX {
+            break port;
+        }
+    };
+
+    let stack = Stack {
+        iface,
+        sockets,
+        link_up: false,
+        configurator,
+        next_local_port: local_port,
+        waker: WakerRegistration::new(),
+    };
+
+    *STACK.borrow().borrow_mut() = Some(stack);
+}
+
+pub fn is_init() -> bool {
+    STACK.borrow().borrow().is_some()
+}
+
+pub async fn run() {
+    futures::future::poll_fn(|cx| {
+        Stack::with(|stack| stack.poll(cx));
+        Poll::<()>::Pending
+    })
+    .await
+}
+
+fn instant_to_smoltcp(instant: Instant) -> SmolInstant {
+    SmolInstant::from_millis(instant.as_millis() as i64)
+}
+
+fn instant_from_smoltcp(instant: SmolInstant) -> Instant {
+    Instant::from_millis(instant.total_millis() as u64)
+}