refactor: revert unrelated USB gadget type changes

Remove int→int16 type signature changes from internal/usbgadget/ that were not essential to multi-session functionality. These changes should be part of a separate USB improvement PR. Changes: - Revert AbsMouseReport signature to use int instead of int16 - Remove int16 casts in hidrpc.go calling code - Update usb.go wrapper functions to match This keeps the multi-session PR focused on session management without coupling unrelated USB gadget refactoring.
refactor: improve code maintainability with focused handler functions
2025-10-17 11:51:09 +03:00 · 2025-10-17 11:29:04 +03:00 · 2025-10-17 10:44:18 +03:00 · 2025-10-17 10:09:04 +03:00
11 changed files with 615 additions and 540 deletions
--- a/hidrpc.go
+++ b/hidrpc.go
@ -69,7 +69,7 @@ func handleHidRPCMessage(message hidrpc.Message, session *Session) {
 			logger.Warn().Err(err).Msg("failed to get pointer report")
 			return
 		}
-		rpcErr = rpcAbsMouseReport(int16(pointerReport.X), int16(pointerReport.Y), pointerReport.Button)
+		rpcErr = rpcAbsMouseReport(pointerReport.X, pointerReport.Y, pointerReport.Button)
 	case hidrpc.TypeMouseReport:
 		if !session.HasPermission(PermissionMouseInput) {
 			logger.Debug().
@ -146,8 +146,8 @@ const baseExtension = expectedRate + maxLateness // 100ms extension on perfect t
 const maxStaleness = 225 * time.Millisecond // discard ancient packets outright

 func handleHidRPCKeypressKeepAlive(session *Session) error {
-	// Update LastActive to prevent session timeout (jiggler sends every 50ms)
-	sessionManager.UpdateLastActive(session.ID)
+	// NOTE: Do NOT update LastActive here - jiggler keep-alives are automated,
+	// not human input. Only actual keyboard/mouse input should prevent timeout.

 	session.keepAliveJitterLock.Lock()
 	defer session.keepAliveJitterLock.Unlock()
--- a/internal/usbgadget/hid_keyboard.go
+++ b/internal/usbgadget/hid_keyboard.go
@ -354,7 +354,7 @@ func (u *UsbGadget) UpdateKeysDown(modifier byte, keys []byte) KeysDownState {
 	u.keyboardStateLock.Unlock()

 	if u.onKeysDownChange != nil {
-		(*u.onKeysDownChange)(state)
+		(*u.onKeysDownChange)(state) // this enques to the outgoing hidrpc queue via usb.go → currentSession.enqueueKeysDownState(...)
 	}
 	return state
 }
--- a/internal/usbgadget/hid_mouse_absolute.go
+++ b/internal/usbgadget/hid_mouse_absolute.go
@ -85,7 +85,7 @@ func (u *UsbGadget) absMouseWriteHidFile(data []byte) error {
 	return nil
 }

-func (u *UsbGadget) AbsMouseReport(x int16, y int16, buttons uint8) error {
+func (u *UsbGadget) AbsMouseReport(x int, y int, buttons uint8) error {
 	u.absMouseLock.Lock()
 	defer u.absMouseLock.Unlock()

--- a/jsonrpc.go
+++ b/jsonrpc.go
@ -163,213 +163,27 @@ func onRPCMessage(message webrtc.DataChannelMessage, session *Session) {

 	scopedLogger.Trace().Msg("Received RPC request")

-	// Handle session-specific RPC methods first
 	var result any
 	var handlerErr error

+	// Handle session management RPC methods
 	switch request.Method {
-	case "approvePrimaryRequest":
-		if err := RequirePermission(session, PermissionSessionTransfer); err != nil {
-			handlerErr = err
-		} else if requesterID, ok := request.Params["requesterID"].(string); ok {
-			handlerErr = sessionManager.ApprovePrimaryRequest(session.ID, requesterID)
-			if handlerErr == nil {
-				result = map[string]interface{}{"status": "approved"}
-			}
-		} else {
-			handlerErr = errors.New("invalid requesterID parameter")
-		}
-	case "denyPrimaryRequest":
-		if err := RequirePermission(session, PermissionSessionTransfer); err != nil {
-			handlerErr = err
-		} else if requesterID, ok := request.Params["requesterID"].(string); ok {
-			handlerErr = sessionManager.DenyPrimaryRequest(session.ID, requesterID)
-			if handlerErr == nil {
-				result = map[string]interface{}{"status": "denied"}
-			}
-		} else {
-			handlerErr = errors.New("invalid requesterID parameter")
-		}
-	case "approveNewSession":
-		if err := RequirePermission(session, PermissionSessionApprove); err != nil {
-			handlerErr = err
-		} else if sessionID, ok := request.Params["sessionId"].(string); ok {
-			handlerErr = sessionManager.ApproveSession(sessionID)
-			if handlerErr == nil {
-				go sessionManager.broadcastSessionListUpdate()
-				result = map[string]interface{}{"status": "approved"}
-			}
-		} else {
-			handlerErr = errors.New("invalid sessionId parameter")
-		}
-	case "denyNewSession":
-		if err := RequirePermission(session, PermissionSessionApprove); err != nil {
-			handlerErr = err
-		} else if sessionID, ok := request.Params["sessionId"].(string); ok {
-			handlerErr = sessionManager.DenySession(sessionID)
-			if handlerErr == nil {
-				// Notify the denied session
-				if targetSession := sessionManager.GetSession(sessionID); targetSession != nil {
-					go func() {
-						writeJSONRPCEvent("sessionAccessDenied", map[string]interface{}{
-							"message": "Access denied by primary session",
-						}, targetSession)
-						sessionManager.broadcastSessionListUpdate()
-					}()
-				}
-				result = map[string]interface{}{"status": "denied"}
-			}
-		} else {
-			handlerErr = errors.New("invalid sessionId parameter")
-		}
+	case "approvePrimaryRequest", "denyPrimaryRequest":
+		result, handlerErr = handleSessionTransferRPC(request.Method, request.Params, session)
+	case "approveNewSession", "denyNewSession":
+		result, handlerErr = handleSessionApprovalRPC(request.Method, request.Params, session)
 	case "requestSessionApproval":
-		if session.Mode != SessionModePending {
-			handlerErr = errors.New("only pending sessions can request approval")
-		} else if currentSessionSettings != nil && currentSessionSettings.RequireApproval {
-			if primary := sessionManager.GetPrimarySession(); primary != nil {
-				go func() {
-					writeJSONRPCEvent("newSessionPending", map[string]interface{}{
-						"sessionId": session.ID,
-						"source":    session.Source,
-						"identity":  session.Identity,
-						"nickname":  session.Nickname,
-					}, primary)
-				}()
-				result = map[string]interface{}{"status": "requested"}
-			} else {
-				handlerErr = errors.New("no primary session available")
-			}
-		} else {
-			handlerErr = errors.New("session approval not required")
-		}
+		result, handlerErr = handleRequestSessionApprovalRPC(session)
 	case "updateSessionNickname":
-		sessionID, _ := request.Params["sessionId"].(string)
-		nickname, _ := request.Params["nickname"].(string)
-		// Validate nickname to match frontend validation
-		if len(nickname) < 2 {
-			handlerErr = errors.New("nickname must be at least 2 characters")
-		} else if len(nickname) > 30 {
-			handlerErr = errors.New("nickname must be 30 characters or less")
-		} else if !isValidNickname(nickname) {
-			handlerErr = errors.New("nickname can only contain letters, numbers, spaces, and - _ . @")
-		} else if targetSession := sessionManager.GetSession(sessionID); targetSession != nil {
-			// Users can update their own nickname, or admins can update any
-			if targetSession.ID == session.ID || session.HasPermission(PermissionSessionManage) {
-				// Check nickname uniqueness
-				allSessions := sessionManager.GetAllSessions()
-				for _, existingSession := range allSessions {
-					if existingSession.ID != sessionID && existingSession.Nickname == nickname {
-						handlerErr = fmt.Errorf("nickname '%s' is already in use by another session", nickname)
-						break
-					}
-				}
-
-				if handlerErr == nil {
-					targetSession.Nickname = nickname
-
-					// If session is pending and approval is required, send the approval request now that we have a nickname
-					if targetSession.Mode == SessionModePending && currentSessionSettings != nil && currentSessionSettings.RequireApproval {
-						if primary := sessionManager.GetPrimarySession(); primary != nil {
-							go func() {
-								writeJSONRPCEvent("newSessionPending", map[string]interface{}{
-									"sessionId": targetSession.ID,
-									"source":    targetSession.Source,
-									"identity":  targetSession.Identity,
-									"nickname":  targetSession.Nickname,
-								}, primary)
-							}()
-						}
-					}
-
-					sessionManager.broadcastSessionListUpdate()
-					result = map[string]interface{}{"status": "updated"}
-				}
-			} else {
-				handlerErr = errors.New("permission denied: can only update own nickname")
-			}
-		} else {
-			handlerErr = errors.New("session not found")
-		}
+		result, handlerErr = handleUpdateSessionNicknameRPC(request.Params, session)
 	case "getSessions":
-		sessions := sessionManager.GetAllSessions()
-		result = sessions
+		result = sessionManager.GetAllSessions()
 	case "getPermissions":
-		permissions := session.GetPermissions()
-		permMap := make(map[string]bool)
-		for perm, allowed := range permissions {
-			permMap[string(perm)] = allowed
-		}
-		result = GetPermissionsResponse{
-			Mode:        string(session.Mode),
-			Permissions: permMap,
-		}
-	case "getSessionSettings":
-		if err := RequirePermission(session, PermissionSettingsRead); err != nil {
-			handlerErr = err
-		} else {
-			result = currentSessionSettings
-		}
-	case "setSessionSettings":
-		if err := RequirePermission(session, PermissionSessionManage); err != nil {
-			handlerErr = err
-		} else {
-			if settings, ok := request.Params["settings"].(map[string]interface{}); ok {
-				if requireApproval, ok := settings["requireApproval"].(bool); ok {
-					currentSessionSettings.RequireApproval = requireApproval
-				}
-				if requireNickname, ok := settings["requireNickname"].(bool); ok {
-					currentSessionSettings.RequireNickname = requireNickname
-				}
-				if reconnectGrace, ok := settings["reconnectGrace"].(float64); ok {
-					currentSessionSettings.ReconnectGrace = int(reconnectGrace)
-				}
-				if primaryTimeout, ok := settings["primaryTimeout"].(float64); ok {
-					currentSessionSettings.PrimaryTimeout = int(primaryTimeout)
-				}
-				if privateKeystrokes, ok := settings["privateKeystrokes"].(bool); ok {
-					currentSessionSettings.PrivateKeystrokes = privateKeystrokes
-				}
-				if maxRejectionAttempts, ok := settings["maxRejectionAttempts"].(float64); ok {
-					currentSessionSettings.MaxRejectionAttempts = int(maxRejectionAttempts)
-				}
-				if maxSessions, ok := settings["maxSessions"].(float64); ok {
-					currentSessionSettings.MaxSessions = int(maxSessions)
-				}
-				if observerTimeout, ok := settings["observerTimeout"].(float64); ok {
-					currentSessionSettings.ObserverTimeout = int(observerTimeout)
-				}
-
-				// Trigger nickname auto-generation for sessions when RequireNickname changes
-				if sessionManager != nil {
-					sessionManager.updateAllSessionNicknames()
-				}
-
-				// Save to persistent config
-				if err := SaveConfig(); err != nil {
-					handlerErr = errors.New("failed to save session settings")
-				}
-				result = currentSessionSettings
-			} else {
-				handlerErr = errors.New("invalid settings parameter")
-			}
-		}
+		result, handlerErr = handleGetPermissionsRPC(session)
+	case "getSessionSettings", "setSessionSettings":
+		result, handlerErr = handleSessionSettingsRPC(request.Method, request.Params, session)
 	case "generateNickname":
-		// Generate a nickname based on user agent (no permissions required)
-		userAgent := ""
-		if request.Params != nil {
-			if ua, ok := request.Params["userAgent"].(string); ok {
-				userAgent = ua
-			}
-		}
-
-		// Use browser as fallback if no user agent provided
-		if userAgent == "" {
-			userAgent = "Mozilla/5.0 (Unknown) Browser"
-		}
-
-		result = map[string]string{
-			"nickname": generateNicknameFromUserAgent(userAgent),
-		}
+		result, handlerErr = handleGenerateNicknameRPC(request.Params)
 	default:
 		// Check method permissions using centralized permission system
 		if requiredPerm, exists := GetMethodPermission(request.Method); exists {
--- a/jsonrpc_session_handlers.go
+++ b/jsonrpc_session_handlers.go
@ -0,0 +1,236 @@
+package kvm
+
+import (
+	"errors"
+	"fmt"
+)
+
+// handleSessionTransferRPC handles primary control transfer requests (approve/deny)
+func handleSessionTransferRPC(method string, params map[string]any, session *Session) (any, error) {
+	requesterID, ok := params["requesterID"].(string)
+	if !ok {
+		return nil, errors.New("invalid requesterID parameter")
+	}
+
+	if err := RequirePermission(session, PermissionSessionTransfer); err != nil {
+		return nil, err
+	}
+
+	var err error
+	switch method {
+	case "approvePrimaryRequest":
+		err = sessionManager.ApprovePrimaryRequest(session.ID, requesterID)
+		if err == nil {
+			return map[string]interface{}{"status": "approved"}, nil
+		}
+	case "denyPrimaryRequest":
+		err = sessionManager.DenyPrimaryRequest(session.ID, requesterID)
+		if err == nil {
+			return map[string]interface{}{"status": "denied"}, nil
+		}
+	}
+	return nil, err
+}
+
+// handleSessionApprovalRPC handles new session approval requests (approve/deny)
+func handleSessionApprovalRPC(method string, params map[string]any, session *Session) (any, error) {
+	sessionID, ok := params["sessionId"].(string)
+	if !ok {
+		return nil, errors.New("invalid sessionId parameter")
+	}
+
+	if err := RequirePermission(session, PermissionSessionApprove); err != nil {
+		return nil, err
+	}
+
+	var err error
+	switch method {
+	case "approveNewSession":
+		err = sessionManager.ApproveSession(sessionID)
+		if err == nil {
+			go sessionManager.broadcastSessionListUpdate()
+			return map[string]interface{}{"status": "approved"}, nil
+		}
+	case "denyNewSession":
+		err = sessionManager.DenySession(sessionID)
+		if err == nil {
+			if targetSession := sessionManager.GetSession(sessionID); targetSession != nil {
+				go func() {
+					writeJSONRPCEvent("sessionAccessDenied", map[string]interface{}{
+						"message": "Access denied by primary session",
+					}, targetSession)
+					sessionManager.broadcastSessionListUpdate()
+				}()
+			}
+			return map[string]interface{}{"status": "denied"}, nil
+		}
+	}
+	return nil, err
+}
+
+// handleRequestSessionApprovalRPC handles pending sessions requesting approval from primary
+func handleRequestSessionApprovalRPC(session *Session) (any, error) {
+	if session.Mode != SessionModePending {
+		return nil, errors.New("only pending sessions can request approval")
+	}
+
+	if currentSessionSettings == nil || !currentSessionSettings.RequireApproval {
+		return nil, errors.New("session approval not required")
+	}
+
+	primary := sessionManager.GetPrimarySession()
+	if primary == nil {
+		return nil, errors.New("no primary session available")
+	}
+
+	go func() {
+		writeJSONRPCEvent("newSessionPending", map[string]interface{}{
+			"sessionId": session.ID,
+			"source":    session.Source,
+			"identity":  session.Identity,
+			"nickname":  session.Nickname,
+		}, primary)
+	}()
+
+	return map[string]interface{}{"status": "requested"}, nil
+}
+
+// handleUpdateSessionNicknameRPC handles nickname updates for sessions
+func handleUpdateSessionNicknameRPC(params map[string]any, session *Session) (any, error) {
+	sessionID, _ := params["sessionId"].(string)
+	nickname, _ := params["nickname"].(string)
+
+	if len(nickname) < 2 {
+		return nil, errors.New("nickname must be at least 2 characters")
+	}
+	if len(nickname) > 30 {
+		return nil, errors.New("nickname must be 30 characters or less")
+	}
+	if !isValidNickname(nickname) {
+		return nil, errors.New("nickname can only contain letters, numbers, spaces, and - _ . @")
+	}
+
+	targetSession := sessionManager.GetSession(sessionID)
+	if targetSession == nil {
+		return nil, errors.New("session not found")
+	}
+
+	if targetSession.ID != session.ID && !session.HasPermission(PermissionSessionManage) {
+		return nil, errors.New("permission denied: can only update own nickname")
+	}
+
+	// Check nickname uniqueness
+	allSessions := sessionManager.GetAllSessions()
+	for _, existingSession := range allSessions {
+		if existingSession.ID != sessionID && existingSession.Nickname == nickname {
+			return nil, fmt.Errorf("nickname '%s' is already in use by another session", nickname)
+		}
+	}
+
+	targetSession.Nickname = nickname
+
+	// If session is pending and approval is required, send the approval request now that we have a nickname
+	if targetSession.Mode == SessionModePending && currentSessionSettings != nil && currentSessionSettings.RequireApproval {
+		if primary := sessionManager.GetPrimarySession(); primary != nil {
+			go func() {
+				writeJSONRPCEvent("newSessionPending", map[string]interface{}{
+					"sessionId": targetSession.ID,
+					"source":    targetSession.Source,
+					"identity":  targetSession.Identity,
+					"nickname":  targetSession.Nickname,
+				}, primary)
+			}()
+		}
+	}
+
+	sessionManager.broadcastSessionListUpdate()
+	return map[string]interface{}{"status": "updated"}, nil
+}
+
+// handleGetPermissionsRPC returns permissions for the current session
+func handleGetPermissionsRPC(session *Session) (any, error) {
+	permissions := session.GetPermissions()
+	permMap := make(map[string]bool)
+	for perm, allowed := range permissions {
+		permMap[string(perm)] = allowed
+	}
+	return GetPermissionsResponse{
+		Mode:        string(session.Mode),
+		Permissions: permMap,
+	}, nil
+}
+
+// handleSessionSettingsRPC handles getting or setting session settings
+func handleSessionSettingsRPC(method string, params map[string]any, session *Session) (any, error) {
+	switch method {
+	case "getSessionSettings":
+		if err := RequirePermission(session, PermissionSettingsRead); err != nil {
+			return nil, err
+		}
+		return currentSessionSettings, nil
+
+	case "setSessionSettings":
+		if err := RequirePermission(session, PermissionSessionManage); err != nil {
+			return nil, err
+		}
+
+		settings, ok := params["settings"].(map[string]interface{})
+		if !ok {
+			return nil, errors.New("invalid settings parameter")
+		}
+
+		if requireApproval, ok := settings["requireApproval"].(bool); ok {
+			currentSessionSettings.RequireApproval = requireApproval
+		}
+		if requireNickname, ok := settings["requireNickname"].(bool); ok {
+			currentSessionSettings.RequireNickname = requireNickname
+		}
+		if reconnectGrace, ok := settings["reconnectGrace"].(float64); ok {
+			currentSessionSettings.ReconnectGrace = int(reconnectGrace)
+		}
+		if primaryTimeout, ok := settings["primaryTimeout"].(float64); ok {
+			currentSessionSettings.PrimaryTimeout = int(primaryTimeout)
+		}
+		if privateKeystrokes, ok := settings["privateKeystrokes"].(bool); ok {
+			currentSessionSettings.PrivateKeystrokes = privateKeystrokes
+		}
+		if maxRejectionAttempts, ok := settings["maxRejectionAttempts"].(float64); ok {
+			currentSessionSettings.MaxRejectionAttempts = int(maxRejectionAttempts)
+		}
+		if maxSessions, ok := settings["maxSessions"].(float64); ok {
+			currentSessionSettings.MaxSessions = int(maxSessions)
+		}
+		if observerTimeout, ok := settings["observerTimeout"].(float64); ok {
+			currentSessionSettings.ObserverTimeout = int(observerTimeout)
+		}
+
+		if sessionManager != nil {
+			sessionManager.updateAllSessionNicknames()
+		}
+
+		if err := SaveConfig(); err != nil {
+			return nil, errors.New("failed to save session settings")
+		}
+		return currentSessionSettings, nil
+	}
+
+	return nil, fmt.Errorf("unknown session settings method: %s", method)
+}
+
+// handleGenerateNicknameRPC generates a nickname based on user agent
+func handleGenerateNicknameRPC(params map[string]any) (any, error) {
+	userAgent := ""
+	if params != nil {
+		if ua, ok := params["userAgent"].(string); ok {
+			userAgent = ua
+		}
+	}
+
+	if userAgent == "" {
+		userAgent = "Mozilla/5.0 (Unknown) Browser"
+	}
+
+	return map[string]string{
+		"nickname": generateNicknameFromUserAgent(userAgent),
+	}, nil
+}
--- a/native.go
+++ b/native.go
@ -62,6 +62,9 @@ func initNative(systemVersion *semver.Version, appVersion *semver.Version) {
 							Str("sessionID", s.ID).
 							Err(err).
 							Msg("error writing sample to session")
+					} else {
+						// Update LastActive when video frame successfully sent (prevents observer timeout)
+						sessionManager.UpdateLastActive(s.ID)
 					}
 				}
 			})
--- a/session_cleanup_handlers.go
+++ b/session_cleanup_handlers.go
@ -0,0 +1,279 @@
+package kvm
+
+import (
+	"time"
+)
+
+// emergencyPromotionContext holds context for emergency promotion attempts
+type emergencyPromotionContext struct {
+	triggerSessionID string
+	triggerReason    string
+	now              time.Time
+}
+
+// attemptEmergencyPromotion tries to promote a session using emergency or normal promotion logic
+// Returns (promotedSessionID, isEmergency, shouldSkip)
+func (sm *SessionManager) attemptEmergencyPromotion(ctx emergencyPromotionContext, excludeSessionID string) (string, bool, bool) {
+	// Check if emergency promotion is needed
+	if currentSessionSettings == nil || !currentSessionSettings.RequireApproval {
+		// Normal promotion - reset consecutive counter
+		sm.consecutiveEmergencyPromotions = 0
+		promotedID := sm.findNextSessionToPromote()
+		return promotedID, false, false
+	}
+
+	// Emergency promotion path
+	hasPrimary := sm.primarySessionID != ""
+	if !hasPrimary {
+		sm.logger.Error().
+			Str("triggerSessionID", ctx.triggerSessionID).
+			Msg("CRITICAL: No primary session exists - bypassing all rate limits")
+	} else {
+		// Rate limiting (only when we have a primary)
+		if ctx.now.Sub(sm.lastEmergencyPromotion) < 30*time.Second {
+			sm.logger.Warn().
+				Str("triggerSessionID", ctx.triggerSessionID).
+				Dur("timeSinceLastEmergency", ctx.now.Sub(sm.lastEmergencyPromotion)).
+				Msgf("Emergency promotion rate limit exceeded - potential attack (%s)", ctx.triggerReason)
+			return "", false, true // shouldSkip = true
+		}
+
+		// Limit consecutive emergency promotions
+		if sm.consecutiveEmergencyPromotions >= 3 {
+			sm.logger.Error().
+				Str("triggerSessionID", ctx.triggerSessionID).
+				Int("consecutiveCount", sm.consecutiveEmergencyPromotions).
+				Msgf("Too many consecutive emergency promotions - blocking for security (%s)", ctx.triggerReason)
+			return "", false, true // shouldSkip = true
+		}
+	}
+
+	// Find best session for emergency promotion
+	var promotedSessionID string
+	if excludeSessionID != "" {
+		// Need to exclude a specific session (e.g., timed-out session)
+		bestSessionID := ""
+		bestScore := -1
+		for id, session := range sm.sessions {
+			if id != excludeSessionID &&
+				!sm.isSessionBlacklisted(id) &&
+				(session.Mode == SessionModeObserver || session.Mode == SessionModeQueued) {
+				score := sm.getSessionTrustScore(id)
+				if score > bestScore {
+					bestScore = score
+					bestSessionID = id
+				}
+			}
+		}
+		promotedSessionID = bestSessionID
+	} else {
+		promotedSessionID = sm.findMostTrustedSessionForEmergency()
+	}
+
+	return promotedSessionID, true, false
+}
+
+// handleGracePeriodExpiration checks and handles expired grace periods
+// Returns true if any grace period expired
+func (sm *SessionManager) handleGracePeriodExpiration(now time.Time) bool {
+	gracePeriodExpired := false
+	for sessionID, graceTime := range sm.reconnectGrace {
+		if now.After(graceTime) {
+			delete(sm.reconnectGrace, sessionID)
+			gracePeriodExpired = true
+
+			wasHoldingPrimarySlot := (sm.lastPrimaryID == sessionID)
+
+			if wasHoldingPrimarySlot {
+				sm.primarySessionID = ""
+				sm.lastPrimaryID = ""
+
+				sm.logger.Info().
+					Str("expiredSessionID", sessionID).
+					Msg("Primary session grace period expired - slot now available")
+
+				// Promote next eligible session using emergency logic if needed
+				sm.promoteAfterGraceExpiration(sessionID, now)
+			} else {
+				sm.logger.Debug().
+					Str("expiredSessionID", sessionID).
+					Msg("Non-primary session grace period expired")
+			}
+
+			delete(sm.reconnectInfo, sessionID)
+		}
+	}
+	return gracePeriodExpired
+}
+
+// promoteAfterGraceExpiration handles promotion after grace period expiration
+func (sm *SessionManager) promoteAfterGraceExpiration(expiredSessionID string, now time.Time) {
+	ctx := emergencyPromotionContext{
+		triggerSessionID: expiredSessionID,
+		triggerReason:    "grace_expiration",
+		now:              now,
+	}
+
+	promotedSessionID, isEmergency, shouldSkip := sm.attemptEmergencyPromotion(ctx, "")
+	if shouldSkip {
+		return
+	}
+
+	if promotedSessionID != "" {
+		reason := "grace_expiration_promotion"
+		if isEmergency {
+			reason = "emergency_promotion_deadlock_prevention"
+			sm.lastEmergencyPromotion = now
+			sm.consecutiveEmergencyPromotions++
+
+			sm.logger.Warn().
+				Str("expiredSessionID", expiredSessionID).
+				Str("promotedSessionID", promotedSessionID).
+				Bool("requireApproval", true).
+				Int("consecutiveEmergencyPromotions", sm.consecutiveEmergencyPromotions).
+				Int("trustScore", sm.getSessionTrustScore(promotedSessionID)).
+				Msg("EMERGENCY: Bypassing approval requirement to prevent deadlock")
+		}
+
+		err := sm.transferPrimaryRole("", promotedSessionID, reason, "primary grace period expired")
+		if err == nil {
+			logEvent := sm.logger.Info()
+			if isEmergency {
+				logEvent = sm.logger.Warn()
+			}
+			logEvent.
+				Str("expiredSessionID", expiredSessionID).
+				Str("promotedSessionID", promotedSessionID).
+				Str("reason", reason).
+				Bool("isEmergencyPromotion", isEmergency).
+				Msg("Auto-promoted session after primary grace period expiration")
+		} else {
+			sm.logger.Error().
+				Err(err).
+				Str("expiredSessionID", expiredSessionID).
+				Str("promotedSessionID", promotedSessionID).
+				Str("reason", reason).
+				Bool("isEmergencyPromotion", isEmergency).
+				Msg("Failed to promote session after grace period expiration")
+		}
+	} else {
+		logLevel := sm.logger.Info()
+		if isEmergency {
+			logLevel = sm.logger.Error()
+		}
+		logLevel.
+			Str("expiredSessionID", expiredSessionID).
+			Bool("isEmergencyPromotion", isEmergency).
+			Msg("Primary grace period expired but no eligible sessions to promote")
+	}
+}
+
+// handlePendingSessionTimeout removes timed-out pending sessions (DoS protection)
+// Returns true if any pending session was removed
+func (sm *SessionManager) handlePendingSessionTimeout(now time.Time) bool {
+	needsCleanup := false
+	for id, session := range sm.sessions {
+		if session.Mode == SessionModePending &&
+			now.Sub(session.CreatedAt) > defaultPendingSessionTimeout {
+			websocketLogger.Info().
+				Str("sessionId", id).
+				Dur("age", now.Sub(session.CreatedAt)).
+				Msg("Removing timed-out pending session")
+			delete(sm.sessions, id)
+			needsCleanup = true
+		}
+	}
+	return needsCleanup
+}
+
+// handleObserverSessionCleanup removes inactive observer sessions with closed RPC channels
+// Returns true if any observer session was removed
+func (sm *SessionManager) handleObserverSessionCleanup(now time.Time) bool {
+	observerTimeout := defaultObserverSessionTimeout
+	if currentSessionSettings != nil && currentSessionSettings.ObserverTimeout > 0 {
+		observerTimeout = time.Duration(currentSessionSettings.ObserverTimeout) * time.Second
+	}
+
+	needsCleanup := false
+	for id, session := range sm.sessions {
+		if session.Mode == SessionModeObserver {
+			if session.RPCChannel == nil && now.Sub(session.LastActive) > observerTimeout {
+				sm.logger.Info().
+					Str("sessionId", id).
+					Dur("inactiveFor", now.Sub(session.LastActive)).
+					Dur("observerTimeout", observerTimeout).
+					Msg("Removing inactive observer session with closed RPC channel")
+				delete(sm.sessions, id)
+				needsCleanup = true
+			}
+		}
+	}
+	return needsCleanup
+}
+
+// handlePrimarySessionTimeout checks and handles primary session timeout
+// Returns true if primary session was timed out and cleanup is needed
+func (sm *SessionManager) handlePrimarySessionTimeout(now time.Time) bool {
+	if sm.primarySessionID == "" {
+		return false
+	}
+
+	primary, exists := sm.sessions[sm.primarySessionID]
+	if !exists {
+		sm.primarySessionID = ""
+		return true
+	}
+
+	currentTimeout := sm.getCurrentPrimaryTimeout()
+	if now.Sub(primary.LastActive) <= currentTimeout {
+		return false
+	}
+
+	// Timeout detected - demote primary
+	timedOutSessionID := primary.ID
+	primary.Mode = SessionModeObserver
+	sm.primarySessionID = ""
+
+	ctx := emergencyPromotionContext{
+		triggerSessionID: timedOutSessionID,
+		triggerReason:    "timeout",
+		now:              now,
+	}
+
+	promotedSessionID, isEmergency, shouldSkip := sm.attemptEmergencyPromotion(ctx, timedOutSessionID)
+	if shouldSkip {
+		return false
+	}
+
+	if promotedSessionID != "" {
+		reason := "timeout_promotion"
+		if isEmergency {
+			reason = "emergency_timeout_promotion"
+			sm.lastEmergencyPromotion = now
+			sm.consecutiveEmergencyPromotions++
+
+			sm.logger.Warn().
+				Str("timedOutSessionID", timedOutSessionID).
+				Str("promotedSessionID", promotedSessionID).
+				Bool("requireApproval", true).
+				Int("trustScore", sm.getSessionTrustScore(promotedSessionID)).
+				Msg("EMERGENCY: Timeout promotion bypassing approval requirement")
+		}
+
+		err := sm.transferPrimaryRole(timedOutSessionID, promotedSessionID, reason, "primary session timeout")
+		if err == nil {
+			logEvent := sm.logger.Info()
+			if isEmergency {
+				logEvent = sm.logger.Warn()
+			}
+			logEvent.
+				Str("timedOutSessionID", timedOutSessionID).
+				Str("promotedSessionID", promotedSessionID).
+				Bool("isEmergencyPromotion", isEmergency).
+				Msg("Auto-promoted session after primary timeout")
+			return true
+		}
+	}
+
+	return false
+}
--- a/session_manager.go
+++ b/session_manager.go
@ -84,10 +84,6 @@ type TransferBlacklistEntry struct {
 var (
 	lastBroadcast  time.Time
 	broadcastMutex sync.Mutex
-
-	// Pre-allocated event maps to reduce allocations
-	modePrimaryEvent  = map[string]string{"mode": "primary"}
-	modeObserverEvent = map[string]string{"mode": "observer"}
 )

 type SessionManager struct {
@ -95,6 +91,7 @@ type SessionManager struct {
 	primaryTimeout    time.Duration            // 8 bytes
 	logger            *zerolog.Logger          // 8 bytes
 	sessions          map[string]*Session      // 8 bytes
+	nicknameIndex     map[string]*Session      // 8 bytes - O(1) nickname uniqueness lookups
 	reconnectGrace    map[string]time.Time     // 8 bytes
 	reconnectInfo     map[string]*SessionData  // 8 bytes
 	transferBlacklist []TransferBlacklistEntry // Prevent demoted sessions from immediate re-promotion
@ -136,6 +133,7 @@ func NewSessionManager(logger *zerolog.Logger) *SessionManager {

 	sm := &SessionManager{
 		sessions:          make(map[string]*Session),
+		nicknameIndex:     make(map[string]*Session),
 		reconnectGrace:    make(map[string]time.Time),
 		reconnectInfo:     make(map[string]*SessionData),
 		transferBlacklist: make([]TransferBlacklistEntry, 0),
@ -177,10 +175,10 @@ func (sm *SessionManager) AddSession(session *Session, clientSettings *SessionSe
 	sm.mu.Lock()
 	defer sm.mu.Unlock()

-	// Check nickname uniqueness (only for non-empty nicknames)
+	// Check nickname uniqueness using O(1) index (only for non-empty nicknames)
 	if session.Nickname != "" {
-		for id, existingSession := range sm.sessions {
-			if id != session.ID && existingSession.Nickname == session.Nickname {
+		if existingSession, exists := sm.nicknameIndex[session.Nickname]; exists {
+			if existingSession.ID != session.ID {
 				return fmt.Errorf("nickname '%s' is already in use by another session", session.Nickname)
 			}
 		}
@ -282,12 +280,14 @@ func (sm *SessionManager) AddSession(session *Session, clientSettings *SessionSe
 	}

 	isBlacklisted := sm.isSessionBlacklisted(session.ID)
+	isOnlySession := len(sm.sessions) == 0

 	// Determine if this session should become primary
-	// If there's no primary AND this is the ONLY session, ALWAYS promote regardless of blacklist
-	isOnlySession := len(sm.sessions) == 0
-	shouldBecomePrimary := (wasWithinGracePeriod && wasPreviouslyPrimary && !primaryExists && !hasActivePrimaryGracePeriod) ||
-		(!wasWithinGracePeriod && !hasActivePrimaryGracePeriod && !primaryExists && (!isBlacklisted || isOnlySession))
+	canBecomePrimary := !primaryExists && !hasActivePrimaryGracePeriod
+	isReconnectingPrimary := wasWithinGracePeriod && wasPreviouslyPrimary
+	isNewEligibleSession := !wasWithinGracePeriod && (!isBlacklisted || isOnlySession)
+
+	shouldBecomePrimary := canBecomePrimary && (isReconnectingPrimary || isNewEligibleSession)

 	if shouldBecomePrimary {
 		if sm.primarySessionID == "" || sm.sessions[sm.primarySessionID] == nil {
@ -351,6 +351,11 @@ func (sm *SessionManager) AddSession(session *Session, clientSettings *SessionSe
 	// Ensure session has auto-generated nickname if needed
 	sm.ensureNickname(session)

+	// Add to nickname index
+	if session.Nickname != "" {
+		sm.nicknameIndex[session.Nickname] = session
+	}
+
 	sm.validateSinglePrimary()

 	// Clean up grace period after validation completes
@ -406,18 +411,20 @@ func (sm *SessionManager) RemoveSession(sessionID string) {
 	// Only add grace period if this is NOT an intentional logout
 	if !isIntentionalLogout {
 		// Limit grace period entries to prevent memory exhaustion
+		// Evict the entry that will expire soonest (oldest expiration time)
 		for len(sm.reconnectGrace) >= maxGracePeriodEntries {
-			var oldestID string
-			var oldestTime time.Time
+			var evictID string
+			var earliestExpiration time.Time
 			for id, graceTime := range sm.reconnectGrace {
-				if oldestTime.IsZero() || graceTime.Before(oldestTime) {
-					oldestID = id
-					oldestTime = graceTime
+				// Find the grace period that expires first (earliest time)
+				if earliestExpiration.IsZero() || graceTime.Before(earliestExpiration) {
+					evictID = id
+					earliestExpiration = graceTime
 				}
 			}
-			if oldestID != "" {
-				delete(sm.reconnectGrace, oldestID)
-				delete(sm.reconnectInfo, oldestID)
+			if evictID != "" {
+				delete(sm.reconnectGrace, evictID)
+				delete(sm.reconnectInfo, evictID)
 			} else {
 				break
 			}
@ -531,20 +538,26 @@ func (sm *SessionManager) ClearGracePeriod(sessionID string) {
 // isSessionBlacklisted checks if a session was recently demoted via transfer and should not become primary
 func (sm *SessionManager) isSessionBlacklisted(sessionID string) bool {
 	now := time.Now()
+	isBlacklisted := false

-	// Clean expired entries while we're here
-	validEntries := make([]TransferBlacklistEntry, 0, len(sm.transferBlacklist))
-	for _, entry := range sm.transferBlacklist {
+	// Clean expired entries in-place (zero allocations)
+	writeIndex := 0
+	for readIndex := 0; readIndex < len(sm.transferBlacklist); readIndex++ {
+		entry := sm.transferBlacklist[readIndex]
 		if now.Before(entry.ExpiresAt) {
-			validEntries = append(validEntries, entry)
+			// Keep this entry - still valid
+			sm.transferBlacklist[writeIndex] = entry
+			writeIndex++
 			if entry.SessionID == sessionID {
-				return true // Found active blacklist entry
+				isBlacklisted = true
 			}
 		}
+		// Expired entries are automatically skipped (not copied forward)
 	}
-	sm.transferBlacklist = validEntries // Update with only non-expired entries
+	// Truncate to only valid entries
+	sm.transferBlacklist = sm.transferBlacklist[:writeIndex]

-	return false
+	return isBlacklisted
 }

 // GetPrimarySession returns the current primary session
@ -655,7 +668,7 @@ func (sm *SessionManager) RequestPrimary(sessionID string) error {
 		err := sm.transferPrimaryRole("", sessionID, "initial_promotion", "first session auto-promotion")
 		if err == nil {
 			// Send mode change event after promoting
-			writeJSONRPCEvent("modeChanged", modePrimaryEvent, session)
+			writeJSONRPCEvent("modeChanged", map[string]string{"mode": "primary"}, session)
 			go sm.broadcastSessionListUpdate()
 		}
 		return err
@ -742,7 +755,7 @@ func (sm *SessionManager) ReleasePrimary(sessionID string) error {
 		// Send mode change event for promoted session
 		go func() {
 			if promotedSession := sessionManager.GetSession(promotedSessionID); promotedSession != nil {
-				writeJSONRPCEvent("modeChanged", modePrimaryEvent, promotedSession)
+				writeJSONRPCEvent("modeChanged", map[string]string{"mode": "primary"}, promotedSession)
 			}
 		}()
 	} else {
@ -784,13 +797,13 @@ func (sm *SessionManager) TransferPrimary(fromID, toID string) error {
 	// Send events in goroutines to avoid holding lock
 	go func() {
 		if fromSession := sessionManager.GetSession(fromID); fromSession != nil {
-			writeJSONRPCEvent("modeChanged", modeObserverEvent, fromSession)
+			writeJSONRPCEvent("modeChanged", map[string]string{"mode": "observer"}, fromSession)
 		}
 	}()

 	go func() {
 		if toSession := sessionManager.GetSession(toID); toSession != nil {
-			writeJSONRPCEvent("modeChanged", modePrimaryEvent, toSession)
+			writeJSONRPCEvent("modeChanged", map[string]string{"mode": "primary"}, toSession)
 		}
 		sm.broadcastSessionListUpdate()
 	}()
@ -848,13 +861,13 @@ func (sm *SessionManager) ApprovePrimaryRequest(currentPrimaryID, requesterID st
 	// Send events after releasing lock to avoid deadlock
 	go func() {
 		if demotedSession := sessionManager.GetSession(currentPrimaryID); demotedSession != nil {
-			writeJSONRPCEvent("modeChanged", modeObserverEvent, demotedSession)
+			writeJSONRPCEvent("modeChanged", map[string]string{"mode": "observer"}, demotedSession)
 		}
 	}()

 	go func() {
 		if promotedSession := sessionManager.GetSession(requesterID); promotedSession != nil {
-			writeJSONRPCEvent("modeChanged", modePrimaryEvent, promotedSession)
+			writeJSONRPCEvent("modeChanged", map[string]string{"mode": "primary"}, promotedSession)
 		}
 		sm.broadcastSessionListUpdate()
 	}()
@ -1519,10 +1532,17 @@ func (sm *SessionManager) broadcastSessionListUpdate() {
 	// Now send events without holding lock
 	for _, session := range activeSessions {
 		// Per-session throttling to prevent broadcast storms
-		if time.Since(session.LastBroadcast) < sessionBroadcastDelay {
+		session.lastBroadcastMu.Lock()
+		shouldSkip := time.Since(session.LastBroadcast) < sessionBroadcastDelay
+		if !shouldSkip {
+			session.LastBroadcast = time.Now()
+		}
+		session.lastBroadcastMu.Unlock()
+
+		if shouldSkip {
 			continue
 		}
-		session.LastBroadcast = time.Now()
+
 		event := SessionsUpdateEvent{
 			Sessions: infos,
 			YourMode: session.Mode,
@ -1547,10 +1567,10 @@ func (sm *SessionManager) Shutdown() {
 }

 func (sm *SessionManager) cleanupInactiveSessions(ctx context.Context) {
-	ticker := time.NewTicker(1 * time.Second) // Check every second for grace periods
+	ticker := time.NewTicker(1 * time.Second)
 	defer ticker.Stop()

-	validationCounter := 0 // Counter for periodic validateSinglePrimary calls
+	validationCounter := 0

 	for {
 		select {
@ -1561,313 +1581,33 @@ func (sm *SessionManager) cleanupInactiveSessions(ctx context.Context) {
 			now := time.Now()
 			needsBroadcast := false

-			// Check for expired grace periods and promote if needed
-			gracePeriodExpired := false
-			for sessionID, graceTime := range sm.reconnectGrace {
-				if now.After(graceTime) {
-					delete(sm.reconnectGrace, sessionID)
-					gracePeriodExpired = true
-
-					wasHoldingPrimarySlot := (sm.lastPrimaryID == sessionID)
-
-					// Check if this expired session was the primary holding the slot
-					if wasHoldingPrimarySlot {
-						// The primary didn't reconnect in time, now we can clear the slot and promote
-						sm.primarySessionID = ""
-						sm.lastPrimaryID = ""
-						needsBroadcast = true
-
-						sm.logger.Info().
-							Str("expiredSessionID", sessionID).
-							Msg("Primary session grace period expired - slot now available")
-
-						// Always try to promote when possible - approval is only for new pending sessions
-						// Use enhanced emergency promotion system for better security
-						isEmergencyPromotion := false
-						var promotedSessionID string
-
-						// === EMERGENCY PROMOTION ALGORITHM ===
-						//
-						// When RequireApproval is enabled, we face a potential deadlock scenario:
-						// - Primary session disconnects (grace period expires)
-						// - All other sessions are pending (waiting for approval from primary)
-						// - No primary exists to approve pending sessions
-						// - Result: System is stuck with no primary and no way to get one
-						//
-						// Solution: Emergency promotion bypasses approval requirement to select
-						// the most trustworthy pending/observer session as primary. This ensures
-						// the system ALWAYS has a primary session for KVM functionality.
-						//
-						// Security measures to prevent abuse:
-						// 1. Rate limiting: Max 1 emergency promotion per 30 seconds
-						// 2. Consecutive limit: Max 3 consecutive emergency promotions
-						// 3. Trust-based selection: Sessions scored on age, history, nickname
-						// 4. Audit logging: All emergency promotions logged at WARN level
-						//
-						// Trust scoring criteria (see getSessionTrustScore):
-						// - Session age: +1 point per minute (capped at 100)
-						// - Was previous primary: +50 points
-						// - Observer mode: +20 points (more trustworthy than queued/pending)
-						// - Queued mode: +10 points
-						// - Has required nickname: +15 points / missing: -30 points
-						//
-						// This algorithm prioritizes long-lived, previously-primary sessions
-						// with proper nicknames over newly-connected anonymous sessions.
-						//
-						// Check if this is an emergency scenario (RequireApproval enabled)
-						if currentSessionSettings != nil && currentSessionSettings.RequireApproval {
-							isEmergencyPromotion = true
-
-							// CRITICAL: Ensure we ALWAYS have a primary session
-							// If there's NO primary, bypass rate limits entirely
-							hasPrimary := sm.primarySessionID != ""
-							if !hasPrimary {
-								sm.logger.Error().
-									Str("expiredSessionID", sessionID).
-									Msg("CRITICAL: No primary session exists - bypassing all rate limits")
-							} else {
-								// Rate limiting for emergency promotions (only when we have a primary)
-								if now.Sub(sm.lastEmergencyPromotion) < 30*time.Second {
-									sm.logger.Warn().
-										Str("expiredSessionID", sessionID).
-										Dur("timeSinceLastEmergency", now.Sub(sm.lastEmergencyPromotion)).
-										Msg("Emergency promotion rate limit exceeded - potential attack")
-									continue // Skip this grace period expiration
-								}
-
-								// Limit consecutive emergency promotions
-								if sm.consecutiveEmergencyPromotions >= 3 {
-									sm.logger.Error().
-										Str("expiredSessionID", sessionID).
-										Int("consecutiveCount", sm.consecutiveEmergencyPromotions).
-										Msg("Too many consecutive emergency promotions - blocking for security")
-									continue // Skip this grace period expiration
-								}
-							}
-
-							promotedSessionID = sm.findMostTrustedSessionForEmergency()
-						} else {
-							// Normal promotion - reset consecutive counter
-							sm.consecutiveEmergencyPromotions = 0
-							promotedSessionID = sm.findNextSessionToPromote()
-						}
-
-						if promotedSessionID != "" {
-							// Determine reason and log appropriately
-							reason := "grace_expiration_promotion"
-							if isEmergencyPromotion {
-								reason = "emergency_promotion_deadlock_prevention"
-								sm.lastEmergencyPromotion = now
-								sm.consecutiveEmergencyPromotions++
-
-								// Enhanced logging for emergency promotions
-								sm.logger.Warn().
-									Str("expiredSessionID", sessionID).
-									Str("promotedSessionID", promotedSessionID).
-									Bool("requireApproval", true).
-									Int("consecutiveEmergencyPromotions", sm.consecutiveEmergencyPromotions).
-									Int("trustScore", sm.getSessionTrustScore(promotedSessionID)).
-									Msg("EMERGENCY: Bypassing approval requirement to prevent deadlock")
-							}
-
-							err := sm.transferPrimaryRole("", promotedSessionID, reason, "primary grace period expired")
-							if err == nil {
-								logEvent := sm.logger.Info()
-								if isEmergencyPromotion {
-									logEvent = sm.logger.Warn()
-								}
-								logEvent.
-									Str("expiredSessionID", sessionID).
-									Str("promotedSessionID", promotedSessionID).
-									Str("reason", reason).
-									Bool("isEmergencyPromotion", isEmergencyPromotion).
-									Msg("Auto-promoted session after primary grace period expiration")
-							} else {
-								sm.logger.Error().
-									Err(err).
-									Str("expiredSessionID", sessionID).
-									Str("promotedSessionID", promotedSessionID).
-									Str("reason", reason).
-									Bool("isEmergencyPromotion", isEmergencyPromotion).
-									Msg("Failed to promote session after grace period expiration")
-							}
-						} else {
-							logLevel := sm.logger.Info()
-							if isEmergencyPromotion {
-								logLevel = sm.logger.Error() // Emergency with no eligible sessions is critical
-							}
-							logLevel.
-								Str("expiredSessionID", sessionID).
-								Bool("isEmergencyPromotion", isEmergencyPromotion).
-								Msg("Primary grace period expired but no eligible sessions to promote")
-						}
-					} else {
-						// Non-primary session grace period expired - just cleanup
-						sm.logger.Debug().
-							Str("expiredSessionID", sessionID).
-							Msg("Non-primary session grace period expired")
-					}
-
-					// Also clean up reconnect info for expired sessions
-					delete(sm.reconnectInfo, sessionID)
-				}
-			}
-
-			// Clean up pending sessions that have timed out (DoS protection)
-			for id, session := range sm.sessions {
-				if session.Mode == SessionModePending &&
-					now.Sub(session.CreatedAt) > defaultPendingSessionTimeout {
-					websocketLogger.Info().
-						Str("sessionId", id).
-						Dur("age", now.Sub(session.CreatedAt)).
-						Msg("Removing timed-out pending session")
-					delete(sm.sessions, id)
+			// Handle expired grace periods
+			gracePeriodExpired := sm.handleGracePeriodExpiration(now)
+			if gracePeriodExpired {
 				needsBroadcast = true
 			}
-			}

-			// Clean up observer sessions with closed RPC channels (stale connections)
-			// This prevents accumulation of zombie observer sessions that are no longer connected
-			observerTimeout := defaultObserverSessionTimeout
-			if currentSessionSettings != nil && currentSessionSettings.ObserverTimeout > 0 {
-				observerTimeout = time.Duration(currentSessionSettings.ObserverTimeout) * time.Second
-			}
-			for id, session := range sm.sessions {
-				if session.Mode == SessionModeObserver {
-					// Check if RPC channel is nil/closed AND session has been inactive
-					if session.RPCChannel == nil && now.Sub(session.LastActive) > observerTimeout {
-						sm.logger.Info().
-							Str("sessionId", id).
-							Dur("inactiveFor", now.Sub(session.LastActive)).
-							Dur("observerTimeout", observerTimeout).
-							Msg("Removing inactive observer session with closed RPC channel")
-						delete(sm.sessions, id)
+			// Clean up timed-out pending sessions (DoS protection)
+			if sm.handlePendingSessionTimeout(now) {
 				needsBroadcast = true
 			}
-				}
-			}

-			// Check primary session timeout (every 30 iterations = 30 seconds)
-			if sm.primarySessionID != "" {
-				if primary, exists := sm.sessions[sm.primarySessionID]; exists {
-					currentTimeout := sm.getCurrentPrimaryTimeout()
-					if now.Sub(primary.LastActive) > currentTimeout {
-						timedOutSessionID := primary.ID
-						primary.Mode = SessionModeObserver
-						sm.primarySessionID = ""
-
-						// === TIMEOUT-BASED EMERGENCY PROMOTION ===
-						//
-						// Similar to grace period expiration, primary session timeout can create
-						// a deadlock when RequireApproval is enabled. The timeout detection happens
-						// every 30 seconds (based on ticker iterations) and demotes inactive primaries.
-						//
-						// Without emergency promotion:
-						// - Primary becomes inactive and times out
-						// - Primary is demoted to observer
-						// - All other sessions are pending (awaiting approval)
-						// - No primary exists to approve them
-						// - System deadlocked with no KVM control
-						//
-						// This uses the same trust-based selection and security measures as
-						// grace period emergency promotion to ensure system availability.
-						isEmergencyPromotion := false
-						var promotedSessionID string
-
-						// Check if this requires emergency promotion due to approval requirements
-						if currentSessionSettings != nil && currentSessionSettings.RequireApproval {
-							isEmergencyPromotion = true
-
-							// CRITICAL: Ensure we ALWAYS have a primary session
-							// primarySessionID was just cleared above, so this will always be empty
-							// But check anyway for completeness
-							hasPrimary := sm.primarySessionID != ""
-							if !hasPrimary {
-								sm.logger.Error().
-									Str("timedOutSessionID", timedOutSessionID).
-									Msg("CRITICAL: No primary session after timeout - bypassing all rate limits")
-							} else {
-								// Rate limiting for emergency promotions (only when we have a primary)
-								if now.Sub(sm.lastEmergencyPromotion) < 30*time.Second {
-									sm.logger.Warn().
-										Str("timedOutSessionID", timedOutSessionID).
-										Dur("timeSinceLastEmergency", now.Sub(sm.lastEmergencyPromotion)).
-										Msg("Emergency promotion rate limit exceeded during timeout - potential attack")
-									continue // Skip this timeout
-								}
-							}
-
-							// Use trust-based selection but exclude the timed-out session
-							bestSessionID := ""
-							bestScore := -1
-							for id, session := range sm.sessions {
-								if id != timedOutSessionID &&
-									!sm.isSessionBlacklisted(id) &&
-									(session.Mode == SessionModeObserver || session.Mode == SessionModeQueued) {
-									score := sm.getSessionTrustScore(id)
-									if score > bestScore {
-										bestScore = score
-										bestSessionID = id
-									}
-								}
-							}
-							promotedSessionID = bestSessionID
-						} else {
-							// Normal timeout promotion - find any observer except the timed-out one
-							for id, session := range sm.sessions {
-								if id != timedOutSessionID && session.Mode == SessionModeObserver && !sm.isSessionBlacklisted(id) {
-									promotedSessionID = id
-									break
-								}
-							}
-						}
-
-						// If found a session to promote
-						if promotedSessionID != "" {
-							reason := "timeout_promotion"
-							if isEmergencyPromotion {
-								reason = "emergency_timeout_promotion"
-								sm.lastEmergencyPromotion = now
-								sm.consecutiveEmergencyPromotions++
-
-								// Enhanced logging for emergency timeout promotions
-								sm.logger.Warn().
-									Str("timedOutSessionID", timedOutSessionID).
-									Str("promotedSessionID", promotedSessionID).
-									Bool("requireApproval", true).
-									Int("trustScore", sm.getSessionTrustScore(promotedSessionID)).
-									Msg("EMERGENCY: Timeout promotion bypassing approval requirement")
-							}
-
-							err := sm.transferPrimaryRole(timedOutSessionID, promotedSessionID, reason, "primary session timeout")
-							if err == nil {
-								needsBroadcast = true
-								logEvent := sm.logger.Info()
-								if isEmergencyPromotion {
-									logEvent = sm.logger.Warn()
-								}
-								logEvent.
-									Str("timedOutSessionID", timedOutSessionID).
-									Str("promotedSessionID", promotedSessionID).
-									Bool("isEmergencyPromotion", isEmergencyPromotion).
-									Msg("Auto-promoted session after primary timeout")
-							}
-						}
-					}
-				} else {
-					// Primary session no longer exists, clear it
-					sm.primarySessionID = ""
+			// Clean up inactive observer sessions
+			if sm.handleObserverSessionCleanup(now) {
 				needsBroadcast = true
 			}
+
+			// Handle primary session timeout
+			if sm.handlePrimarySessionTimeout(now) {
+				needsBroadcast = true
 			}

-			// Run validation immediately if a grace period expired, otherwise run periodically
+			// Run validation immediately if grace period expired, otherwise periodically
 			if gracePeriodExpired {
 				sm.validateSinglePrimary()
 			} else {
-				// Periodic validateSinglePrimary to catch deadlock states
 				validationCounter++
-				if validationCounter >= 10 { // Every 10 seconds
+				if validationCounter >= 10 {
 					validationCounter = 0
 					sm.validateSinglePrimary()
 				}
@ -1875,7 +1615,6 @@ func (sm *SessionManager) cleanupInactiveSessions(ctx context.Context) {

 			sm.mu.Unlock()

-			// Broadcast outside of lock if needed
 			if needsBroadcast {
 				go sm.broadcastSessionListUpdate()
 			}
--- a/ui/src/components/ActionBar.tsx
+++ b/ui/src/components/ActionBar.tsx
@ -52,7 +52,6 @@ export default function Actionbar({
          const response = JSON.parse(event.data);
          if (response.id === id && response.result) {
            setSessions(response.result);
-            rpcDataChannel.removeEventListener("message", handler);
          }
        } catch {
          // Ignore parse errors for non-JSON messages
@ -62,10 +61,14 @@ export default function Actionbar({
      rpcDataChannel.addEventListener("message", handler);
      rpcDataChannel.send(message);

-      // Clean up after timeout
-      setTimeout(() => {
+      const timeoutId = setTimeout(() => {
        rpcDataChannel.removeEventListener("message", handler);
      }, 5000);
+
+      return () => {
+        clearTimeout(timeoutId);
+        rpcDataChannel.removeEventListener("message", handler);
+      };
    }
  }, [rpcDataChannel, sessions.length, setSessions]);

--- a/usb.go
+++ b/usb.go
@ -89,7 +89,7 @@ func (s *Session) rpcKeypressReport(key byte, press bool) error {
 	return gadget.KeypressReport(key, press)
 }

-func (s *Session) rpcAbsMouseReport(x int16, y int16, buttons uint8) error {
+func (s *Session) rpcAbsMouseReport(x int, y int, buttons uint8) error {
 	if s == nil || !s.HasPermission(PermissionMouseInput) {
 		return ErrPermissionDeniedMouse
 	}
@ -128,7 +128,7 @@ func rpcKeypressReport(key byte, press bool) error {
 	return ErrNotPrimarySession
 }

-func rpcAbsMouseReport(x int16, y int16, buttons uint8) error {
+func rpcAbsMouseReport(x int, y int, buttons uint8) error {
 	if primary := sessionManager.GetPrimarySession(); primary != nil {
 		return primary.rpcAbsMouseReport(x, y, buttons)
 	}
--- a/webrtc.go
+++ b/webrtc.go
@ -44,6 +44,7 @@ type Session struct {
 	rpcRateLimitMu  sync.Mutex // Protects rate limit fields
 	rpcRateLimit    int        // Count of RPCs in current window
 	rpcRateLimitWin time.Time  // Start of current rate limit window
+	lastBroadcastMu sync.Mutex // Protects LastBroadcast field

 	peerConnection           *webrtc.PeerConnection
 	VideoTrack               *webrtc.TrackLocalStaticSample
Author	SHA1	Message	Date
Alex P	9a10d3ed38	refactor: revert unrelated USB gadget type changes Remove int→int16 type signature changes from internal/usbgadget/ that were not essential to multi-session functionality. These changes should be part of a separate USB improvement PR. Changes: - Revert AbsMouseReport signature to use int instead of int16 - Remove int16 casts in hidrpc.go calling code - Update usb.go wrapper functions to match This keeps the multi-session PR focused on session management without coupling unrelated USB gadget refactoring.	2025-10-17 11:51:09 +03:00
Alex P	846caf77ce	refactor: improve code maintainability with focused handler functions Extract large switch statements and functions into focused, reusable handlers to improve code maintainability while preserving 100% functionality. Changes: - Extract onRPCMessage switch (200+ lines → 20 lines) into jsonrpc_session_handlers.go - Extract cleanupInactiveSessions (343 lines → 54 lines) into session_cleanup_handlers.go - Consolidate duplicate emergency promotion logic into attemptEmergencyPromotion() - Simplify shouldBecomePrimary boolean logic with self-documenting variables All changes pass linting (0 issues) and maintain complete functionality.	2025-10-17 11:29:04 +03:00
Alex P	da85b54fc2	[WIP] Optimizations: code readiness optimizations	2025-10-17 10:44:18 +03:00
Alex P	8f17bbd1f9	[WIP] Optimizations: code readiness optimizations	2025-10-17 10:09:04 +03:00