Rebase on master

4 files changed, 169 insertions, 76 deletions

diff --git a/examples/std/src/bin/net.rs b/examples/std/src/bin/net.rs
index 9b1450b72..451850d99 100644
--- a/examples/std/src/bin/net.rs
+++ b/examples/std/src/bin/net.rs
@@ -1,9 +1,11 @@
 #![feature(type_alias_impl_trait)]
 
+use std::default::Default;
+
 use clap::Parser;
 use embassy_executor::{Executor, Spawner};
 use embassy_net::tcp::TcpSocket;
-use embassy_net::{ConfigStrategy, Ipv4Address, Ipv4Cidr, Stack, StackResources};
+use embassy_net::{Config, Ipv4Address, Ipv4Cidr, Stack, StackResources};
 use embedded_io::asynch::Write;
 use heapless::Vec;
 use log::*;
@@ -48,13 +50,13 @@ async fn main_task(spawner: Spawner) {
 
     // Choose between dhcp or static ip
     let config = if opts.static_ip {
-        ConfigStrategy::Static(embassy_net::Config {
+        Config::Static(embassy_net::StaticConfig {
             address: Ipv4Cidr::new(Ipv4Address::new(192, 168, 69, 2), 24),
             dns_servers: Vec::new(),
             gateway: Some(Ipv4Address::new(192, 168, 69, 1)),
         })
     } else {
-        ConfigStrategy::Dhcp
+        Config::Dhcp(Default::default())
     };
 
     // Generate random seed
@@ -63,12 +65,7 @@ async fn main_task(spawner: Spawner) {
     let seed = u64::from_le_bytes(seed);
 
     // Init network stack
-    let stack = &*singleton!(Stack::new(
-        device,
-        config,
-        singleton!(StackResources::<1, 2, 8>::new()),
-        seed
-    ));
+    let stack = &*singleton!(Stack::new(device, config, singleton!(StackResources::<2>::new()), seed));
 
     // Launch network task
     spawner.spawn(net_task(stack)).unwrap();
diff --git a/examples/std/src/bin/net_dns.rs b/examples/std/src/bin/net_dns.rs
new file mode 100644
index 000000000..e1cc45a38
--- /dev/null
+++ b/examples/std/src/bin/net_dns.rs
@@ -0,0 +1,98 @@
+#![feature(type_alias_impl_trait)]
+
+use std::default::Default;
+
+use clap::Parser;
+use embassy_executor::{Executor, Spawner};
+use embassy_net::dns::DnsQueryType;
+use embassy_net::{Config, Ipv4Address, Ipv4Cidr, Stack, StackResources};
+use heapless::Vec;
+use log::*;
+use rand_core::{OsRng, RngCore};
+use static_cell::StaticCell;
+
+#[path = "../tuntap.rs"]
+mod tuntap;
+
+use crate::tuntap::TunTapDevice;
+
+macro_rules! singleton {
+    ($val:expr) => {{
+        type T = impl Sized;
+        static STATIC_CELL: StaticCell<T> = StaticCell::new();
+        STATIC_CELL.init_with(move || $val)
+    }};
+}
+
+#[derive(Parser)]
+#[clap(version = "1.0")]
+struct Opts {
+    /// TAP device name
+    #[clap(long, default_value = "tap0")]
+    tap: String,
+    /// use a static IP instead of DHCP
+    #[clap(long)]
+    static_ip: bool,
+}
+
+#[embassy_executor::task]
+async fn net_task(stack: &'static Stack<TunTapDevice>) -> ! {
+    stack.run().await
+}
+
+#[embassy_executor::task]
+async fn main_task(spawner: Spawner) {
+    let opts: Opts = Opts::parse();
+
+    // Init network device
+    let device = TunTapDevice::new(&opts.tap).unwrap();
+
+    // Choose between dhcp or static ip
+    let config = if opts.static_ip {
+        Config::Static(embassy_net::StaticConfig {
+            address: Ipv4Cidr::new(Ipv4Address::new(192, 168, 69, 1), 24),
+            dns_servers: Vec::from_slice(&[Ipv4Address::new(8, 8, 4, 4).into(), Ipv4Address::new(8, 8, 8, 8).into()])
+                .unwrap(),
+            gateway: Some(Ipv4Address::new(192, 168, 69, 100)),
+        })
+    } else {
+        Config::Dhcp(Default::default())
+    };
+
+    // Generate random seed
+    let mut seed = [0; 8];
+    OsRng.fill_bytes(&mut seed);
+    let seed = u64::from_le_bytes(seed);
+
+    // Init network stack
+    let stack: &Stack<_> = &*singleton!(Stack::new(device, config, singleton!(StackResources::<2>::new()), seed));
+
+    // Launch network task
+    spawner.spawn(net_task(stack)).unwrap();
+
+    let host = "example.com";
+    info!("querying host {:?}...", host);
+    match stack.dns_query(host, DnsQueryType::A).await {
+        Ok(r) => {
+            info!("query response: {:?}", r);
+        }
+        Err(e) => {
+            warn!("query error: {:?}", e);
+        }
+    };
+}
+
+static EXECUTOR: StaticCell<Executor> = StaticCell::new();
+
+fn main() {
+    env_logger::builder()
+        .filter_level(log::LevelFilter::Debug)
+        .filter_module("async_io", log::LevelFilter::Info)
+        .format_timestamp_nanos()
+        .init();
+
+    let executor = EXECUTOR.init(Executor::new());
+    executor.run(|spawner| {
+        spawner.spawn(main_task(spawner)).unwrap();
+    });
+}
diff --git a/examples/std/src/bin/net_udp.rs b/examples/std/src/bin/net_udp.rs
index 392a97f0d..f1923f180 100644
--- a/examples/std/src/bin/net_udp.rs
+++ b/examples/std/src/bin/net_udp.rs
@@ -3,7 +3,7 @@
 use clap::Parser;
 use embassy_executor::{Executor, Spawner};
 use embassy_net::udp::UdpSocket;
-use embassy_net::{ConfigStrategy, Ipv4Address, Ipv4Cidr, PacketMetadata, Stack, StackResources};
+use embassy_net::{Config, Ipv4Address, Ipv4Cidr, PacketMetadata, Stack, StackResources};
 use heapless::Vec;
 use log::*;
 use rand_core::{OsRng, RngCore};
@@ -47,13 +47,13 @@ async fn main_task(spawner: Spawner) {
 
     // Choose between dhcp or static ip
     let config = if opts.static_ip {
-        ConfigStrategy::Static(embassy_net::Config {
+        Config::Static(embassy_net::StaticConfig {
             address: Ipv4Cidr::new(Ipv4Address::new(192, 168, 69, 2), 24),
             dns_servers: Vec::new(),
             gateway: Some(Ipv4Address::new(192, 168, 69, 1)),
         })
     } else {
-        ConfigStrategy::Dhcp
+        Config::Dhcp(Default::default())
     };
 
     // Generate random seed
@@ -62,12 +62,7 @@ async fn main_task(spawner: Spawner) {
     let seed = u64::from_le_bytes(seed);
 
     // Init network stack
-    let stack = &*singleton!(Stack::new(
-        device,
-        config,
-        singleton!(StackResources::<1, 2, 8>::new()),
-        seed
-    ));
+    let stack = &*singleton!(Stack::new(device, config, singleton!(StackResources::<2>::new()), seed));
 
     // Launch network task
     spawner.spawn(net_task(stack)).unwrap();
diff --git a/examples/std/src/tuntap.rs b/examples/std/src/tuntap.rs
index a0cace7f7..d918a2e62 100644
--- a/examples/std/src/tuntap.rs
+++ b/examples/std/src/tuntap.rs
@@ -1,8 +1,10 @@
 use std::io;
 use std::io::{Read, Write};
 use std::os::unix::io::{AsRawFd, RawFd};
+use std::task::Context;
 
 use async_io::Async;
+use embassy_net_driver::{self, Capabilities, Driver, LinkState};
 use log::*;
 
 pub const SIOCGIFMTU: libc::c_ulong = 0x8921;
@@ -125,54 +127,35 @@ impl io::Write for TunTap {
 
 pub struct TunTapDevice {
     device: Async<TunTap>,
-    waker: Option<Waker>,
 }
 
 impl TunTapDevice {
     pub fn new(name: &str) -> io::Result<TunTapDevice> {
         Ok(Self {
             device: Async::new(TunTap::new(name)?)?,
-            waker: None,
         })
     }
 }
 
-use core::task::Waker;
-use std::task::Context;
-
-use embassy_net::{Device, DeviceCapabilities, LinkState, Packet, PacketBox, PacketBoxExt, PacketBuf};
-
-impl Device for TunTapDevice {
-    fn is_transmit_ready(&mut self) -> bool {
-        true
-    }
+impl Driver for TunTapDevice {
+    type RxToken<'a> = RxToken where Self: 'a;
+    type TxToken<'a> = TxToken<'a> where Self: 'a;
 
-    fn transmit(&mut self, pkt: PacketBuf) {
-        // todo handle WouldBlock
-        match self.device.get_mut().write(&pkt) {
-            Ok(_) => {}
-            Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
-                info!("transmit WouldBlock");
-            }
-            Err(e) => panic!("transmit error: {:?}", e),
-        }
-    }
-
-    fn receive(&mut self) -> Option<PacketBuf> {
-        let mut pkt = PacketBox::new(Packet::new()).unwrap();
+    fn receive(&mut self, cx: &mut Context) -> Option<(Self::RxToken<'_>, Self::TxToken<'_>)> {
+        let mut buf = vec![0; self.device.get_ref().mtu];
         loop {
-            match self.device.get_mut().read(&mut pkt[..]) {
+            match self.device.get_mut().read(&mut buf) {
                 Ok(n) => {
-                    return Some(pkt.slice(0..n));
+                    buf.truncate(n);
+                    return Some((
+                        RxToken { buffer: buf },
+                        TxToken {
+                            device: &mut self.device,
+                        },
+                    ));
                 }
                 Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
-                    let ready = if let Some(w) = self.waker.as_ref() {
-                        let mut cx = Context::from_waker(w);
-                        self.device.poll_readable(&mut cx).is_ready()
-                    } else {
-                        false
-                    };
-                    if !ready {
+                    if !self.device.poll_readable(cx).is_ready() {
                         return None;
                     }
                 }
@@ -181,37 +164,19 @@ impl Device for TunTapDevice {
         }
     }
 
-    fn register_waker(&mut self, w: &Waker) {
-        match self.waker {
-            // Optimization: If both the old and new Wakers wake the same task, we can simply
-            // keep the old waker, skipping the clone. (In most executor implementations,
-            // cloning a waker is somewhat expensive, comparable to cloning an Arc).
-            Some(ref w2) if (w2.will_wake(w)) => {}
-            _ => {
-                // clone the new waker and store it
-                if let Some(old_waker) = core::mem::replace(&mut self.waker, Some(w.clone())) {
-                    // We had a waker registered for another task. Wake it, so the other task can
-                    // reregister itself if it's still interested.
-                    //
-                    // If two tasks are waiting on the same thing concurrently, this will cause them
-                    // to wake each other in a loop fighting over this WakerRegistration. This wastes
-                    // CPU but things will still work.
-                    //
-                    // If the user wants to have two tasks waiting on the same thing they should use
-                    // a more appropriate primitive that can store multiple wakers.
-                    old_waker.wake()
-                }
-            }
-        }
+    fn transmit(&mut self, _cx: &mut Context) -> Option<Self::TxToken<'_>> {
+        Some(TxToken {
+            device: &mut self.device,
+        })
     }
 
-    fn capabilities(&self) -> DeviceCapabilities {
-        let mut caps = DeviceCapabilities::default();
+    fn capabilities(&self) -> Capabilities {
+        let mut caps = Capabilities::default();
         caps.max_transmission_unit = self.device.get_ref().mtu;
         caps
     }
 
-    fn link_state(&mut self) -> LinkState {
+    fn link_state(&mut self, _cx: &mut Context) -> LinkState {
         LinkState::Up
     }
 
@@ -219,3 +184,41 @@ impl Device for TunTapDevice {
         [0x02, 0x03, 0x04, 0x05, 0x06, 0x07]
     }
 }
+
+#[doc(hidden)]
+pub struct RxToken {
+    buffer: Vec<u8>,
+}
+
+impl embassy_net_driver::RxToken for RxToken {
+    fn consume<R, F>(mut self, f: F) -> R
+    where
+        F: FnOnce(&mut [u8]) -> R,
+    {
+        f(&mut self.buffer)
+    }
+}
+
+#[doc(hidden)]
+pub struct TxToken<'a> {
+    device: &'a mut Async<TunTap>,
+}
+
+impl<'a> embassy_net_driver::TxToken for TxToken<'a> {
+    fn consume<R, F>(self, len: usize, f: F) -> R
+    where
+        F: FnOnce(&mut [u8]) -> R,
+    {
+        let mut buffer = vec![0; len];
+        let result = f(&mut buffer);
+
+        // todo handle WouldBlock with async
+        match self.device.get_mut().write(&buffer) {
+            Ok(_) => {}
+            Err(e) if e.kind() == io::ErrorKind::WouldBlock => info!("transmit WouldBlock"),
+            Err(e) => panic!("transmit error: {:?}", e),
+        }
+
+        result
+    }
+}