fix(lldp): use mutexes to protect state

internal/lldp/lldp.go

@@ -102,10 +102,10 @@ func (l *LLDP) Start() error {
 
 // StartRx starts the LLDP receiver if not already running
 func (l *LLDP) startRx() error {
-	l.mu.Lock()
+	l.mu.RLock()
 	running := l.rxRunning
 	enabled := l.enableRx
-	l.mu.Unlock()
+	l.mu.RUnlock()
 
 	if running || !enabled {
 		return nil

internal/lldp/rx.go

@@ -88,6 +88,11 @@ func (l *LLDP) setUpCapture() error {
 }
 
 func (l *LLDP) doCapture(logger *zerolog.Logger) {
+	if l.pktSourceRx == nil || l.rxCtx == nil {
+		logger.Error().Msg("packet source or RX context not initialized")
+		return
+	}
+
 	l.rxWaitGroup.Add(1)
 	defer l.rxWaitGroup.Done()
 

internal/lldp/tx.go

@@ -194,7 +194,9 @@ func (l *LLDP) startTx() error {
 		cancel()
 	}
 
+	l.mu.Lock()
 	l.txCtx, l.txCancel = context.WithCancel(context.Background())
+	l.mu.Unlock()
 
 	if err := l.setUpTx(); err != nil {
 		return fmt.Errorf("failed to set up TX: %w", err)