fix(gateway): secure control and terminal ownership

gateway/apollo_native.go

@@ -289,6 +289,7 @@ type nativeApolloSession struct {
 	audio                       chan ProviderMedia
 	events                      chan ProviderEvent
 	mu                          sync.Mutex
+	eventMu                     sync.Mutex
 	mediaMu                     sync.Mutex
 	controlMu                   sync.Mutex
 	state                       protocol.ProviderState
@@ -686,10 +687,32 @@ func (s *nativeApolloSession) handleApolloControlPayload(_ uint8, _ bool, payloa
 }
 
 func (s *nativeApolloSession) emitProviderEvent(event ProviderEvent) {
+	if !s.enqueueProviderEvent(event) {
+		s.handleApolloDisconnect(ErrProviderMalformed)
+	}
+}
+
+func (s *nativeApolloSession) enqueueProviderEvent(event ProviderEvent) bool {
+	s.eventMu.Lock()
+	defer s.eventMu.Unlock()
 	select {
 	case s.events <- event:
+		return true
 	default:
-		s.handleApolloDisconnect(ErrProviderMalformed)
+	}
+	if event.Kind != ProviderEventTerminated && event.Kind != ProviderEventDisconnected {
+		return false
+	}
+	select {
+	case <-s.events:
+	default:
+		return false
+	}
+	select {
+	case s.events <- event:
+		return true
+	default:
+		return false
 	}
 }
 
@@ -706,10 +729,7 @@ func (s *nativeApolloSession) handleApolloDisconnect(err error) {
 		}
 		s.state.State = ProviderStateDisconnected
 		s.mu.Unlock()
-		select {
-		case s.events <- ProviderEvent{Kind: ProviderEventDisconnected}:
-		default:
-		}
+		s.enqueueProviderEvent(ProviderEvent{Kind: ProviderEventDisconnected})
 	})
 }