release capture if emulation disabled on target

lan-mouse-ipc/src/lib.rs

@@ -161,7 +161,7 @@ pub struct ClientState {
     /// This should generally be the socket address where data
     /// was last received from.
     pub active_addr: Option<SocketAddr>,
-    /// tracks whether or not the client is responding to pings
+    /// tracks whether or not the client is available for emulation
     pub alive: bool,
     /// ips from dns
     pub dns_ips: Vec<IpAddr>,
@@ -239,7 +239,7 @@ pub enum FrontendRequest {
     RemoveAuthorizedKey(String),
 }
 
-#[derive(Clone, Copy, Debug, Default, Serialize, Deserialize)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Default, Serialize, Deserialize)]
 pub enum Status {
     #[default]
     Disabled,

lan-mouse-proto/src/lib.rs

@@ -61,8 +61,8 @@ pub enum ProtoEvent {
     /// Ping event for tracking unresponsive clients.
     /// A client has to respond with [`ProtoEvent::Pong`].
     Ping,
-    /// Response to [`ProtoEvent::Ping`]
+    /// Response to [`ProtoEvent::Ping`], true if emulation is enabled / available
-    Pong,
+    Pong(bool),
 }
 
 impl Display for ProtoEvent {
@@ -73,7 +73,13 @@ impl Display for ProtoEvent {
             ProtoEvent::Ack(s) => write!(f, "Ack({s})"),
             ProtoEvent::Input(e) => write!(f, "{e}"),
             ProtoEvent::Ping => write!(f, "ping"),
-            ProtoEvent::Pong => write!(f, "pong"),
+            ProtoEvent::Pong(alive) => {
+                write!(
+                    f,
+                    "pong: {}",
+                    if *alive { "alive" } else { "not available" }
+                )
+            }
         }
     }
 }
@@ -110,7 +116,7 @@ impl ProtoEvent {
                 },
             },
             ProtoEvent::Ping => EventType::Ping,
-            ProtoEvent::Pong => EventType::Pong,
+            ProtoEvent::Pong(_) => EventType::Pong,
             ProtoEvent::Enter(_) => EventType::Enter,
             ProtoEvent::Leave(_) => EventType::Leave,
             ProtoEvent::Ack(_) => EventType::Ack,
@@ -164,7 +170,7 @@ impl TryFrom<[u8; MAX_EVENT_SIZE]> for ProtoEvent {
                 },
             ))),
             EventType::Ping => Ok(Self::Ping),
-            EventType::Pong => Ok(Self::Pong),
+            EventType::Pong => Ok(Self::Pong(decode_u8(&mut buf)? != 0)),
             EventType::Enter => Ok(Self::Enter(decode_u8(&mut buf)?.try_into()?)),
             EventType::Leave => Ok(Self::Leave(decode_u32(&mut buf)?)),
             EventType::Ack => Ok(Self::Ack(decode_u32(&mut buf)?)),
@@ -228,7 +234,7 @@ impl From<ProtoEvent> for ([u8; MAX_EVENT_SIZE], usize) {
                     },
                 },
                 ProtoEvent::Ping => {}
-                ProtoEvent::Pong => {}
+                ProtoEvent::Pong(alive) => encode_u8(buf, len, alive as u8),
                 ProtoEvent::Enter(pos) => encode_u8(buf, len, pos as u8),
                 ProtoEvent::Leave(serial) => encode_u32(buf, len, serial),
                 ProtoEvent::Ack(serial) => encode_u32(buf, len, serial),

src/client.rs

@@ -224,27 +224,41 @@ impl ClientManager {
             .collect()
     }
 
-    pub(crate) fn set_active_addr(&self, handle: u64, addr: Option<SocketAddr>) {
+    pub(crate) fn set_active_addr(&self, handle: ClientHandle, addr: Option<SocketAddr>) {
         if let Some((_, s)) = self.clients.borrow_mut().get_mut(handle as usize) {
             s.active_addr = addr;
         }
     }
 
-    pub(crate) fn active_addr(&self, handle: u64) -> Option<SocketAddr> {
+    pub(crate) fn set_alive(&self, handle: ClientHandle, alive: bool) {
+        if let Some((_, s)) = self.clients.borrow_mut().get_mut(handle as usize) {
+            s.alive = alive;
+        }
+    }
+
+    pub(crate) fn active_addr(&self, handle: ClientHandle) -> Option<SocketAddr> {
         self.clients
             .borrow()
             .get(handle as usize)
             .and_then(|(_, s)| s.active_addr)
     }
 
-    pub(crate) fn get_port(&self, handle: u64) -> Option<u16> {
+    pub(crate) fn alive(&self, handle: ClientHandle) -> bool {
+        self.clients
+            .borrow()
+            .get(handle as usize)
+            .map(|(_, s)| s.alive)
+            .unwrap_or(false)
+    }
+
+    pub(crate) fn get_port(&self, handle: ClientHandle) -> Option<u16> {
         self.clients
             .borrow()
             .get(handle as usize)
             .map(|(c, _)| c.port)
     }
 
-    pub(crate) fn get_ips(&self, handle: u64) -> Option<HashSet<IpAddr>> {
+    pub(crate) fn get_ips(&self, handle: ClientHandle) -> Option<HashSet<IpAddr>> {
         self.clients
             .borrow()
             .get(handle as usize)

src/connect.rs

@@ -33,6 +33,8 @@ pub(crate) enum LanMouseConnectionError {
     Webrtc(#[from] webrtc_util::Error),
     #[error("not connected")]
     NotConnected,
+    #[error("emulation is disabled on the target device")]
+    TargetEmulationDisabled,
 }
 
 async fn connect(
@@ -104,6 +106,9 @@ impl LanMouseConnection {
                 conns.get(&addr).cloned()
             };
             if let Some(conn) = conn {
+                if !self.server.client_manager.alive(handle) {
+                    return Err(LanMouseConnectionError::TargetEmulationDisabled);
+                }
                 log::trace!("{event} >->->->->- {addr}");
                 match conn.send(buf).await {
                     Ok(_) => return Ok(()),
@@ -220,7 +225,10 @@ async fn receive_loop(
     while let Ok(_) = conn.recv(&mut buf).await {
         if let Ok(event) = buf.try_into() {
             match event {
-                ProtoEvent::Pong => server.client_manager.set_active_addr(handle, Some(addr)),
+                ProtoEvent::Pong(b) => {
+                    server.client_manager.set_active_addr(handle, Some(addr));
+                    server.client_manager.set_alive(handle, b);
+                }
                 event => tx.send((handle, event)).expect("channel closed"),
             }
         }

src/emulation.rs

@@ -55,7 +55,7 @@ impl Emulation {
                             listener.reply(addr, ProtoEvent::Ack(0)).await;
                         }
                         ProtoEvent::Input(event) => emulation_proxy.consume(event, addr),
-                        ProtoEvent::Ping => listener.reply(addr, ProtoEvent::Pong).await,
+                        ProtoEvent::Ping => listener.reply(addr, ProtoEvent::Pong(server.emulation_status.get() == Status::Enabled)).await,
                         _ => {}
                     }
                 }