Merge #1264

1264: Add multicast to udp socket r=Dirbaio a=28Smiles

This should make it possible to implement mDNS for embassy-net, which in turn is essential for smart home

Co-authored-by: Leon Camus <leon.c@gmx.de>
Co-authored-by: 28Smiles <Leon.c@gmx.de>

embassy-net/Cargo.toml

@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 [package.metadata.embassy_docs]
 src_base = "https://github.com/embassy-rs/embassy/blob/embassy-net-v$VERSION/embassy-net/src/"
 src_base_git = "https://github.com/embassy-rs/embassy/blob/$COMMIT/embassy-net/src/"
-features = ["nightly", "unstable-traits", "defmt", "tcp", "udp", "dns", "dhcpv4", "proto-ipv6", "medium-ethernet", "medium-ip"]
+features = ["nightly", "unstable-traits", "defmt", "tcp", "udp", "dns", "dhcpv4", "proto-ipv6", "medium-ethernet", "medium-ip", "igmp"]
 target = "thumbv7em-none-eabi"
 
 [features]
@@ -27,6 +27,7 @@ dhcpv4 = ["medium-ethernet", "smoltcp/socket-dhcpv4"]
 proto-ipv6 = ["smoltcp/proto-ipv6"]
 medium-ethernet = ["smoltcp/medium-ethernet"]
 medium-ip = ["smoltcp/medium-ip"]
+igmp = ["smoltcp/proto-igmp"]
 
 [dependencies]
 

embassy-net/src/lib.rs

@@ -304,6 +304,37 @@ impl<D: Driver + 'static> Stack<D> {
     }
 }
 
+#[cfg(feature = "igmp")]
+impl<D: Driver + smoltcp::phy::Device + 'static> Stack<D> {
+    pub fn join_multicast_group<T>(&self, addr: T) -> Result<bool, smoltcp::iface::MulticastError>
+    where
+        T: Into<IpAddress>,
+    {
+        let addr = addr.into();
+
+        self.with_mut(|s, i| {
+            s.iface
+                .join_multicast_group(&mut i.device, addr, instant_to_smoltcp(Instant::now()))
+        })
+    }
+
+    pub fn leave_multicast_group<T>(&self, addr: T) -> Result<bool, smoltcp::iface::MulticastError>
+    where
+        T: Into<IpAddress>,
+    {
+        let addr = addr.into();
+
+        self.with_mut(|s, i| {
+            s.iface
+                .leave_multicast_group(&mut i.device, addr, instant_to_smoltcp(Instant::now()))
+        })
+    }
+
+    pub fn has_multicast_group<T: Into<IpAddress>>(&self, addr: T) -> bool {
+        self.socket.borrow().iface.has_multicast_group(addr)
+    }
+}
+
 impl SocketStack {
     #[allow(clippy::absurd_extreme_comparisons, dead_code)]
     pub fn get_local_port(&mut self) -> u16 {