Handle cancellation

embassy-net/Cargo.toml

@@ -40,6 +40,7 @@ smoltcp = { version = "0.9.0", default-features = false, features = [
 ]}
 
 embassy-net-driver = { version = "0.1.0", path = "../embassy-net-driver" }
+embassy-hal-common = { version = "0.1.0", path = "../embassy-hal-common" }
 embassy-time = { version = "0.1.0", path = "../embassy-time" }
 embassy-sync = { version = "0.1.0", path = "../embassy-sync" }
 embedded-io = { version = "0.4.0", optional = true }

embassy-net/src/dns.rs

@@ -11,6 +11,7 @@ use smoltcp::iface::{Interface, SocketHandle};
 pub use smoltcp::socket::dns::DnsQuery;
 use smoltcp::socket::dns::{self, GetQueryResultError, StartQueryError, MAX_ADDRESS_COUNT};
 pub use smoltcp::wire::{DnsQueryType, IpAddress};
+use embassy_hal_common::drop::OnDrop;
 
 use crate::{SocketStack, Stack};
 
@@ -93,7 +94,15 @@ impl<'a> DnsSocket<'a> {
             Err(e) => return Err(e.into()),
         };
 
-        poll_fn(|cx| {
+        let handle = self.handle;
+        let drop = OnDrop::new(|| {
+            let s = &mut *self.stack.borrow_mut();
+            let socket = s.sockets.get_mut::<dns::Socket>(handle);
+            socket.cancel_query(query);
+            s.waker.wake();
+        });
+
+        let res = poll_fn(|cx| {
             self.with_mut(|s, _| match s.get_query_result(query) {
                 Ok(addrs) => Poll::Ready(Ok(addrs)),
                 Err(GetQueryResultError::Pending) => {
@@ -103,7 +112,10 @@ impl<'a> DnsSocket<'a> {
                 Err(e) => Poll::Ready(Err(e.into())),
             })
         })
-        .await
+        .await;
+
+        drop.defuse();
+        res
     }
 }