hidrpc.go

@@ -25,7 +25,11 @@ func handleHidRPCMessage(message hidrpc.Message, session *Session) {
 		}
 		session.hidRPCAvailable = true
 	case hidrpc.TypeKeypressReport, hidrpc.TypeKeyboardReport:
-		rpcErr = handleHidRPCKeyboardInput(message)
+		keysDownState, err := handleHidRPCKeyboardInput(message)
+		if keysDownState != nil {
+			session.reportHidRPCKeysDownState(*keysDownState)
+		}
+		rpcErr = err
 	case hidrpc.TypeKeypressKeepAliveReport:
 		gadget.DelayAutoRelease()
 	case hidrpc.TypePointerReport:
@@ -91,25 +95,27 @@ func onHidMessage(msg hidQueueMessage, session *Session) {
 	}
 }
 
-func handleHidRPCKeyboardInput(message hidrpc.Message) error {
+func handleHidRPCKeyboardInput(message hidrpc.Message) (*usbgadget.KeysDownState, error) {
 	switch message.Type() {
 	case hidrpc.TypeKeypressReport:
 		keypressReport, err := message.KeypressReport()
 		if err != nil {
 			logger.Warn().Err(err).Msg("failed to get keypress report")
-			return err
+			return nil, err
 		}
-		return rpcKeypressReport(keypressReport.Key, keypressReport.Press)
+		keysDownState, rpcError := rpcKeypressReport(keypressReport.Key, keypressReport.Press)
+		return &keysDownState, rpcError
 	case hidrpc.TypeKeyboardReport:
 		keyboardReport, err := message.KeyboardReport()
 		if err != nil {
 			logger.Warn().Err(err).Msg("failed to get keyboard report")
-			return err
+			return nil, err
 		}
-		return rpcKeyboardReport(keyboardReport.Modifier, keyboardReport.Keys)
+		keysDownState, rpcError := rpcKeyboardReport(keyboardReport.Modifier, keyboardReport.Keys)
+		return &keysDownState, rpcError
 	}
 
-	return fmt.Errorf("unknown HID RPC message type: %d", message.Type())
+	return nil, fmt.Errorf("unknown HID RPC message type: %d", message.Type())
 }
 
 func reportHidRPC(params any, session *Session) {

internal/hidrpc/hidrpc.go

@@ -99,3 +99,11 @@ func NewKeydownStateMessage(state usbgadget.KeysDownState) *Message {
 		d: data,
 	}
 }
+
+// NewKeypressKeepAliveMessage creates a new keypress keep alive message.
+func NewKeypressKeepAliveMessage() *Message {
+	return &Message{
+		t: TypeKeypressKeepAliveReport,
+		d: []byte{},
+	}
+}

internal/usbgadget/hid_keyboard.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"sync"
 	"time"
 
 	"github.com/rs/xid"
@@ -28,7 +27,7 @@ var keyboardConfig = gadgetConfigItem{
 
 // macOS default: 15 * 15 = 225ms https://discussions.apple.com/thread/1316947?sortBy=rank
 // Linux default: 250ms https://man.archlinux.org/man/kbdrate.8.en
-// Windows default: 1s `HKEY_CURRENT_USER\Control Panel\Accessibility\Keyboard Response\AutoRepeatDelay`
+// Windows default: 1ms `HKEY_CURRENT_USER\Control Panel\Accessibility\Keyboard Response\AutoRepeatDelay`
 const autoReleaseKeyboardInterval = time.Millisecond * 100
 
 // Source: https://www.kernel.org/doc/Documentation/usb/gadget_hid.txt
@@ -154,79 +153,95 @@ func (u *UsbGadget) GetKeysDownState() KeysDownState {
 	return u.keysDownState
 }
 
+func (u *UsbGadget) updateKeyDownState(state KeysDownState) {
+	u.log.Trace().Interface("old", u.keysDownState).Interface("new", state).Msg("acquiring keyboardStateLock for updateKeyDownState")
+
+	// this is intentional to unlock keyboard state lock before onKeysDownChange callback
+	{
+		u.keyboardStateLock.Lock()
+		defer u.keyboardStateLock.Unlock()
+
+		if u.keysDownState.Modifier == state.Modifier &&
+			bytes.Equal(u.keysDownState.Keys, state.Keys) {
+			return // No change in key down state
+		}
+
+		u.log.Trace().Interface("old", u.keysDownState).Interface("new", state).Msg("keysDownState updated")
+		u.keysDownState = state
+	}
+
+	if u.onKeysDownChange != nil {
+		u.log.Trace().Interface("state", state).Msg("calling onKeysDownChange")
+		(*u.onKeysDownChange)(state)
+		u.log.Trace().Interface("state", state).Msg("onKeysDownChange called")
+	}
+}
+
 func (u *UsbGadget) SetOnKeysDownChange(f func(state KeysDownState)) {
 	u.onKeysDownChange = &f
 }
 
 func (u *UsbGadget) scheduleAutoRelease(key byte) {
+	u.log.Trace().Msg("scheduling autoRelease")
 	u.kbdAutoReleaseLock.Lock()
 	defer unlockWithLog(&u.kbdAutoReleaseLock, u.log, "autoRelease scheduled")
 
-	if u.kbdAutoReleaseTimers[key] != nil {
+	if u.kbdAutoReleaseTimer != nil {
-		u.kbdAutoReleaseTimers[key].Stop()
+		u.kbdAutoReleaseTimer.Stop()
 	}
 
-	u.kbdAutoReleaseTimers[key] = time.AfterFunc(autoReleaseKeyboardInterval, func() {
+	u.kbdAutoReleaseTimer = time.AfterFunc(autoReleaseKeyboardInterval, func() {
-		u.performAutoRelease(key)
+		u.performAutoRelease()
 	})
 }
 
-func (u *UsbGadget) cancelAutoRelease(key byte) {
+func (u *UsbGadget) cancelAutoRelease() {
+	u.log.Trace().Msg("cancelling autoRelease")
 	u.kbdAutoReleaseLock.Lock()
 	defer unlockWithLog(&u.kbdAutoReleaseLock, u.log, "autoRelease cancelled")
 
-	if timer := u.kbdAutoReleaseTimers[key]; timer != nil {
+	if u.kbdAutoReleaseTimer != nil {
-		timer.Stop()
+		u.kbdAutoReleaseTimer.Stop()
-		u.kbdAutoReleaseTimers[key] = nil
-		delete(u.kbdAutoReleaseTimers, key)
 	}
 }
 
 func (u *UsbGadget) DelayAutoRelease() {
+	u.log.Trace().Msg("delaying autoRelease")
 	u.kbdAutoReleaseLock.Lock()
 	defer unlockWithLog(&u.kbdAutoReleaseLock, u.log, "autoRelease delayed")
 
-	if u.kbdAutoReleaseTimers == nil {
+	if u.kbdAutoReleaseTimer == nil {
 		return
 	}
 
-	for _, timer := range u.kbdAutoReleaseTimers {
+	u.kbdAutoReleaseTimer.Reset(autoReleaseKeyboardInterval)
-		if timer != nil {
+
-			timer.Reset(autoReleaseKeyboardInterval)
+	u.log.Trace().Msg("auto-release timer reset")
-		}
-	}
 }
 
-func (u *UsbGadget) performAutoRelease(key byte) {
+func (u *UsbGadget) performAutoRelease() {
+	u.log.Trace().Msg("performing autoRelease")
 	u.kbdAutoReleaseLock.Lock()
+	defer unlockWithLog(&u.kbdAutoReleaseLock, u.log, "autoRelease unlocked")
 
-	if u.kbdAutoReleaseTimers[key] == nil {
+	key := u.kbdAutoReleaseLastKey
-		u.log.Warn().Uint8("key", key).Msg("autoRelease timer not found")
+
-		u.kbdAutoReleaseLock.Unlock()
+	select {
+	case <-u.keyboardStateCtx.Done():
 		return
+	default:
 	}
 
-	u.kbdAutoReleaseTimers[key].Stop()
+	// we just reset the keyboard state to 0 no matter what
-	u.kbdAutoReleaseTimers[key] = nil
+	u.log.Trace().Uint8("key", key).Msg("auto-releasing keyboard key")
-	delete(u.kbdAutoReleaseTimers, key)
+	_, err := u.keypressReport(key, false, false)
-	u.kbdAutoReleaseLock.Unlock()
+	if err != nil {
-
+		u.log.Warn().Uint8("key", key).Msg("failed to auto-release keyboard key")
-	// Skip if already released
-	state := u.GetKeysDownState()
-	alreadyReleased := true
-
-	for i := range state.Keys {
-		if state.Keys[i] == key {
-			alreadyReleased = false
-			break
-		}
 	}
 
-	if alreadyReleased {
+	u.kbdAutoReleaseTimer = nil
-		return
-	}
 
-	u.keypressReport(key, false)
+	u.log.Trace().Uint8("key", key).Msg("auto release performed")
 }
 
 func (u *UsbGadget) listenKeyboardEvents() {
@@ -298,11 +313,7 @@ func (u *UsbGadget) OpenKeyboardHidFile() error {
 	return u.openKeyboardHidFile()
 }
 
-var keyboardWriteHidFileLock sync.Mutex
-
 func (u *UsbGadget) keyboardWriteHidFile(modifier byte, keys []byte) error {
-	keyboardWriteHidFileLock.Lock()
-	defer keyboardWriteHidFileLock.Unlock()
 	if err := u.openKeyboardHidFile(); err != nil {
 		return err
 	}
@@ -326,29 +337,17 @@ func (u *UsbGadget) UpdateKeysDown(modifier byte, keys []byte) KeysDownState {
 		}
 	}
 
-	state := KeysDownState{
+	downState := KeysDownState{
 		Modifier: modifier,
 		Keys:     []byte(keys[:]),
 	}
-
+	u.updateKeyDownState(downState)
-	u.keyboardStateLock.Lock()
+	return downState
-
-	if u.keysDownState.Modifier == state.Modifier &&
-		bytes.Equal(u.keysDownState.Keys, state.Keys) {
-		u.keyboardStateLock.Unlock()
-		return state // No change in key down state
-	}
-
-	u.keysDownState = state
-	u.keyboardStateLock.Unlock()
-
-	if u.onKeysDownChange != nil {
-		(*u.onKeysDownChange)(state) // this enques to the outgoing hidrpc queue via usb.go → currentSession.enqueueKeysDownState(...)
-	}
-	return state
 }
 
-func (u *UsbGadget) KeyboardReport(modifier byte, keys []byte) error {
+func (u *UsbGadget) KeyboardReport(modifier byte, keys []byte) (KeysDownState, error) {
+	u.keyboardLock.Lock()
+	defer u.keyboardLock.Unlock()
 	defer u.resetUserInputTime()
 
 	if len(keys) > hidKeyBufferSize {
@@ -363,8 +362,7 @@ func (u *UsbGadget) KeyboardReport(modifier byte, keys []byte) error {
 		u.log.Warn().Uint8("modifier", modifier).Uints8("keys", keys).Msg("Could not write keyboard report to hidg0")
 	}
 
-	u.UpdateKeysDown(modifier, keys)
+	return u.UpdateKeysDown(modifier, keys), err
-	return err
 }
 
 const (
@@ -404,10 +402,10 @@ var KeyCodeToMaskMap = map[byte]byte{
 	RightSuper:   ModifierMaskRightSuper,
 }
 
-func (u *UsbGadget) keypressReport(key byte, press bool) (KeysDownState, error) {
+func (u *UsbGadget) keypressReportNonThreadSafe(key byte, press bool, autoRelease bool) (KeysDownState, error) {
 	defer u.resetUserInputTime()
 
-	l := u.log.With().Uint8("key", key).Bool("press", press).Logger()
+	l := u.log.With().Uint8("key", key).Bool("press", press).Bool("autoRelease", autoRelease).Logger()
 	if l.GetLevel() <= zerolog.DebugLevel {
 		requestID := xid.New()
 		l = l.With().Str("requestID", requestID.String()).Logger()
@@ -472,21 +470,64 @@ func (u *UsbGadget) keypressReport(key byte, press bool) (KeysDownState, error)
 		}
 	}
 
+	if l.GetLevel() <= zerolog.DebugLevel {
+		l = l.With().Uint8("modifier", modifier).Uints8("keys", keys).Logger()
+	}
+
+	l.Trace().Msg("writing keypress report to hidg0")
+
 	err := u.keyboardWriteHidFile(modifier, keys)
+	if err != nil {
+		l.Warn().Msg("Could not write keypress report to hidg0")
+	}
+
+	l.Trace().Msg("keypress report written to hidg0")
+
+	if press {
+		{
+			l.Trace().Msg("acquiring kbdAutoReleaseLock to update last key")
+			u.kbdAutoReleaseLock.Lock()
+			u.kbdAutoReleaseLastKey = key
+			unlockWithLog(&u.kbdAutoReleaseLock, u.log, "last key updated")
+		}
+
+		if autoRelease {
+			u.scheduleAutoRelease(key)
+		}
+	} else {
+		if autoRelease {
+			u.cancelAutoRelease()
+		}
+	}
+
 	return u.UpdateKeysDown(modifier, keys), err
 }
 
-func (u *UsbGadget) KeypressReport(key byte, press bool) error {
+type keypressReportResult struct {
-	state, err := u.keypressReport(key, press)
+	KeysDownState KeysDownState
-	isRolledOver := state.Keys[0] == hidErrorRollOver
+	Error         error
-
+}
-	if isRolledOver {
+
-		u.cancelAutoRelease(key)
+func (u *UsbGadget) keypressReport(key byte, press bool, autoRelease bool) (KeysDownState, error) {
-	} else if press {
+	u.keyboardLock.Lock()
-		u.scheduleAutoRelease(key)
+	defer u.keyboardLock.Unlock()
-	} else {
+
-		u.cancelAutoRelease(key)
+	r := make(chan keypressReportResult)
-	}
+	go func() {
-
+		state, err := u.keypressReportNonThreadSafe(key, press, autoRelease)
-	return err
+		r <- keypressReportResult{KeysDownState: state, Error: err}
+	}()
+
+	select {
+	case <-time.After(1 * time.Second):
+		u.log.Warn().Msg("keypressReport timed out, possibly stuck")
+		return u.keysDownState, fmt.Errorf("keypressReport timed out, possibly stuck")
+	case ret := <-r:
+		u.log.Debug().Msg("keypressReport handled")
+		return ret.KeysDownState, ret.Error
+	}
+}
+
+func (u *UsbGadget) KeypressReport(key byte, press bool) (KeysDownState, error) {
+	return u.keypressReport(key, press, true)
 }

internal/usbgadget/usbgadget.go

@@ -68,8 +68,9 @@ type UsbGadget struct {
 	keyboardState byte          // keyboard latched state (NumLock, CapsLock, ScrollLock, Compose, Kana)
 	keysDownState KeysDownState // keyboard dynamic state (modifier keys and pressed keys)
 
-	kbdAutoReleaseLock   sync.Mutex
+	kbdAutoReleaseLock    sync.Mutex
-	kbdAutoReleaseTimers map[byte]*time.Timer
+	kbdAutoReleaseTimer   *time.Timer
+	kbdAutoReleaseLastKey byte
 
 	keyboardStateLock   sync.Mutex
 	keyboardStateCtx    context.Context
@@ -121,24 +122,23 @@ func newUsbGadget(name string, configMap map[string]gadgetConfigItem, enabledDev
 	keyboardCtx, keyboardCancel := context.WithCancel(context.Background())
 
 	g := &UsbGadget{
-		name:                 name,
+		name:                name,
-		kvmGadgetPath:        path.Join(gadgetPath, name),
+		kvmGadgetPath:       path.Join(gadgetPath, name),
-		configC1Path:         path.Join(gadgetPath, name, "configs/c.1"),
+		configC1Path:        path.Join(gadgetPath, name, "configs/c.1"),
-		configMap:            configMap,
+		configMap:           configMap,
-		customConfig:         *config,
+		customConfig:        *config,
-		configLock:           sync.Mutex{},
+		configLock:          sync.Mutex{},
-		keyboardLock:         sync.Mutex{},
+		keyboardLock:        sync.Mutex{},
-		absMouseLock:         sync.Mutex{},
+		absMouseLock:        sync.Mutex{},
-		relMouseLock:         sync.Mutex{},
+		relMouseLock:        sync.Mutex{},
-		txLock:               sync.Mutex{},
+		txLock:              sync.Mutex{},
-		keyboardStateCtx:     keyboardCtx,
+		keyboardStateCtx:    keyboardCtx,
-		keyboardStateCancel:  keyboardCancel,
+		keyboardStateCancel: keyboardCancel,
-		keyboardState:        0,
+		keyboardState:       0,
-		keysDownState:        KeysDownState{Modifier: 0, Keys: []byte{0, 0, 0, 0, 0, 0}}, // must be initialized to hidKeyBufferSize (6) zero bytes
+		keysDownState:       KeysDownState{Modifier: 0, Keys: []byte{0, 0, 0, 0, 0, 0}}, // must be initialized to hidKeyBufferSize (6) zero bytes
-		kbdAutoReleaseTimers: make(map[byte]*time.Timer),
+		enabledDevices:      *enabledDevices,
-		enabledDevices:       *enabledDevices,
+		lastUserInput:       time.Now(),
-		lastUserInput:        time.Now(),
+		log:                 logger,
-		log:                  logger,
 
 		strictMode: config.strictMode,
 
@@ -163,10 +163,10 @@ func (u *UsbGadget) Close() error {
 
 	// Stop auto-release timer
 	u.kbdAutoReleaseLock.Lock()
-	for _, timer := range u.kbdAutoReleaseTimers {
+	if u.kbdAutoReleaseTimer != nil {
-		timer.Stop()
+		u.kbdAutoReleaseTimer.Stop()
+		u.kbdAutoReleaseTimer = nil
 	}
-	u.kbdAutoReleaseTimers = make(map[byte]*time.Timer)
 	u.kbdAutoReleaseLock.Unlock()
 
 	// Close HID files

jsonrpc.go

@@ -1059,7 +1059,9 @@ var rpcHandlers = map[string]RPCHandler{
 	"getNetworkSettings":     {Func: rpcGetNetworkSettings},
 	"setNetworkSettings":     {Func: rpcSetNetworkSettings, Params: []string{"settings"}},
 	"renewDHCPLease":         {Func: rpcRenewDHCPLease},
+	"keyboardReport":         {Func: rpcKeyboardReport, Params: []string{"modifier", "keys"}},
 	"getKeyboardLedState":    {Func: rpcGetKeyboardLedState},
+	"keypressReport":         {Func: rpcKeypressReport, Params: []string{"key", "press"}},
 	"getKeyDownState":        {Func: rpcGetKeysDownState},
 	"absMouseReport":         {Func: rpcAbsMouseReport, Params: []string{"x", "y", "buttons"}},
 	"relMouseReport":         {Func: rpcRelMouseReport, Params: []string{"dx", "dy", "buttons"}},

ui/src/components/WebRTCVideo.tsx

@@ -237,7 +237,6 @@ export default function WebRTCVideo() {
   const keyDownHandler = useCallback(
     (e: KeyboardEvent) => {
       e.preventDefault();
-      if (e.repeat) return;
       const code = getAdjustedKeyCode(e);
       const hidKey = keys[code];
 

ui/src/hooks/useHidRpc.ts

@@ -36,16 +36,11 @@ export function useHidRpc(onHidRpcMessage?: (payload: RpcMessage) => void) {
   }, [rpcHidChannel, rpcHidProtocolVersion]);
 
   const rpcHidUnreliableReady = useMemo(() => {
-    return (
+    return rpcHidUnreliableChannel?.readyState === "open" && rpcHidProtocolVersion !== null;
-      rpcHidUnreliableChannel?.readyState === "open" && rpcHidProtocolVersion !== null
-    );
   }, [rpcHidUnreliableChannel, rpcHidProtocolVersion]);
 
   const rpcHidUnreliableNonOrderedReady = useMemo(() => {
-    return (
+    return rpcHidUnreliableNonOrderedChannel?.readyState === "open" && rpcHidProtocolVersion !== null;
-      rpcHidUnreliableNonOrderedChannel?.readyState === "open" &&
-      rpcHidProtocolVersion !== null
-    );
   }, [rpcHidUnreliableNonOrderedChannel, rpcHidProtocolVersion]);
 
   const rpcHidStatus = useMemo(() => {
@@ -55,52 +50,41 @@ export function useHidRpc(onHidRpcMessage?: (payload: RpcMessage) => void) {
     return `ready (v${rpcHidProtocolVersion}${rpcHidUnreliableReady ? "+u" : ""})`;
   }, [rpcHidChannel, rpcHidUnreliableReady, rpcHidProtocolVersion]);
 
-  const sendMessage = useCallback(
+  const sendMessage = useCallback((message: RpcMessage, { ignoreHandshakeState, useUnreliableChannel, requireOrdered = true }: sendMessageParams = {}) => {
-    (
+    if (rpcHidChannel?.readyState !== "open") return;
-      message: RpcMessage,
+    if (!rpcHidReady && !ignoreHandshakeState) return;
-      {
-        ignoreHandshakeState,
-        useUnreliableChannel,
-        requireOrdered = true,
-      }: sendMessageParams = {},
-    ) => {
-      if (rpcHidChannel?.readyState !== "open") return;
-      if (!rpcHidReady && !ignoreHandshakeState) return;
 
-      let data: Uint8Array | undefined;
+    let data: Uint8Array | undefined;
-      try {
+    try {
-        data = message.marshal();
+      data = message.marshal();
-      } catch (e) {
+    } catch (e) {
-        console.error("Failed to send HID RPC message", e);
+      console.error("Failed to send HID RPC message", e);
+    }
+    if (!data) return;
+
+    if (useUnreliableChannel) {
+      if (requireOrdered && rpcHidUnreliableReady) {
+        rpcHidUnreliableChannel?.send(data as unknown as ArrayBuffer);
+      } else if (!requireOrdered && rpcHidUnreliableNonOrderedReady) {
+        rpcHidUnreliableNonOrderedChannel?.send(data as unknown as ArrayBuffer);
       }
-      if (!data) return;
+      return;
+    }
 
-      if (useUnreliableChannel) {
+    rpcHidChannel?.send(data as unknown as ArrayBuffer);
-        if (requireOrdered && rpcHidUnreliableReady) {
+  }, [
-          rpcHidUnreliableChannel?.send(data as unknown as ArrayBuffer);
+    rpcHidChannel,
-        } else if (!requireOrdered && rpcHidUnreliableNonOrderedReady) {
+    rpcHidUnreliableChannel,
-          rpcHidUnreliableNonOrderedChannel?.send(data as unknown as ArrayBuffer);
+    rpcHidUnreliableNonOrderedChannel,
-        }
+    rpcHidReady,
-        return;
+    rpcHidUnreliableReady,
-      }
+    rpcHidUnreliableNonOrderedReady,
-
+  ]);
-      rpcHidChannel?.send(data as unknown as ArrayBuffer);
-    },
-    [
-      rpcHidChannel,
-      rpcHidUnreliableChannel,
-      rpcHidUnreliableNonOrderedChannel,
-      rpcHidReady,
-      rpcHidUnreliableReady,
-      rpcHidUnreliableNonOrderedReady,
-    ],
-  );
 
   const reportKeyboardEvent = useCallback(
     (keys: number[], modifier: number) => {
       sendMessage(new KeyboardReportMessage(keys, modifier));
-    },
+    }, [sendMessage],
-    [sendMessage],
   );
 
   const reportKeypressEvent = useCallback(
@@ -112,9 +96,7 @@ export function useHidRpc(onHidRpcMessage?: (payload: RpcMessage) => void) {
 
   const reportAbsMouseEvent = useCallback(
     (x: number, y: number, buttons: number) => {
-      sendMessage(new PointerReportMessage(x, y, buttons), {
+      sendMessage(new PointerReportMessage(x, y, buttons), { useUnreliableChannel: true });
-        useUnreliableChannel: true,
-      });
     },
     [sendMessage],
   );
@@ -127,7 +109,7 @@ export function useHidRpc(onHidRpcMessage?: (payload: RpcMessage) => void) {
   );
 
   const reportKeypressKeepAlive = useCallback(() => {
-    sendMessage(KEEPALIVE_MESSAGE);
+    sendMessage(KEEPALIVE_MESSAGE, { useUnreliableChannel: true, requireOrdered: false });
   }, [sendMessage]);
 
   const sendHandshake = useCallback(() => {
@@ -137,25 +119,22 @@ export function useHidRpc(onHidRpcMessage?: (payload: RpcMessage) => void) {
     sendMessage(new HandshakeMessage(HID_RPC_VERSION), { ignoreHandshakeState: true });
   }, [rpcHidChannel, rpcHidProtocolVersion, sendMessage]);
 
-  const handleHandshake = useCallback(
+  const handleHandshake = useCallback((message: HandshakeMessage) => {
-    (message: HandshakeMessage) => {
+    if (!message.version) {
-      if (!message.version) {
+      console.error("Received handshake message without version", message);
-        console.error("Received handshake message without version", message);
+      return;
-        return;
+    }
-      }
 
-      if (message.version > HID_RPC_VERSION) {
+    if (message.version > HID_RPC_VERSION) {
-        // we assume that the UI is always using the latest version of the HID RPC protocol
+      // we assume that the UI is always using the latest version of the HID RPC protocol
-        // so we can't support this
+      // so we can't support this
-        // TODO: use capabilities to determine rather than version number
+      // TODO: use capabilities to determine rather than version number
-        console.error("Server is using a newer HID RPC version than the client", message);
+      console.error("Server is using a newer HID RPC version than the client", message);
-        return;
+      return;
-      }
+    }
 
-      setRpcHidProtocolVersion(message.version);
+    setRpcHidProtocolVersion(message.version);
-    },
+  }, [setRpcHidProtocolVersion]);
-    [setRpcHidProtocolVersion],
-  );
 
   useEffect(() => {
     if (!rpcHidChannel) return;
@@ -189,12 +168,12 @@ export function useHidRpc(onHidRpcMessage?: (payload: RpcMessage) => void) {
     };
 
     const openHandler = () => {
-      console.info("HID RPC channel opened");
+      console.warn("HID RPC channel opened");
       sendHandshake();
     };
 
     const closeHandler = () => {
-      console.info("HID RPC channel closed");
+      console.warn("HID RPC channel closed");
       setRpcHidProtocolVersion(null);
     };
 
@@ -207,13 +186,15 @@ export function useHidRpc(onHidRpcMessage?: (payload: RpcMessage) => void) {
       rpcHidChannel.removeEventListener("close", closeHandler);
       rpcHidChannel.removeEventListener("open", openHandler);
     };
-  }, [
+  },
-    rpcHidChannel,
+    [
-    onHidRpcMessage,
+      rpcHidChannel,
-    setRpcHidProtocolVersion,
+      onHidRpcMessage,
-    sendHandshake,
+      setRpcHidProtocolVersion,
-    handleHandshake,
+      sendHandshake,
-  ]);
+      handleHandshake,
+    ],
+  );
 
   return {
     reportKeyboardEvent,

ui/src/hooks/useKeyboard.ts

@@ -1,12 +1,6 @@
 import { useCallback, useRef } from "react";
 
-import {
+import { hidErrorRollOver, hidKeyBufferSize, KeysDownState, useHidStore, useRTCStore } from "@/hooks/stores";
-  hidErrorRollOver,
-  hidKeyBufferSize,
-  KeysDownState,
-  useHidStore,
-  useRTCStore,
-} from "@/hooks/stores";
 import { JsonRpcResponse, useJsonRpc } from "@/hooks/useJsonRpc";
 import { useHidRpc } from "@/hooks/useHidRpc";
 import { KeyboardLedStateMessage, KeysDownStateMessage } from "@/hooks/hidRpc";
@@ -37,7 +31,7 @@ export default function useKeyboard() {
     reportKeypressEvent: sendKeypressEventHidRpc,
     reportKeypressKeepAlive: sendKeypressKeepAliveHidRpc,
     rpcHidReady,
-  } = useHidRpc(message => {
+  } = useHidRpc((message) => {
     switch (message.constructor) {
       case KeysDownStateMessage:
         setKeysDownState((message as KeysDownStateMessage).keysDownState);
@@ -58,9 +52,7 @@ export default function useKeyboard() {
     async (state: KeysDownState) => {
       if (rpcDataChannel?.readyState !== "open" && !rpcHidReady) return;
 
-      console.debug(
+      console.debug(`Send keyboardReport keys: ${state.keys}, modifier: ${state.modifier}`);
-        `Send keyboardReport keys: ${state.keys}, modifier: ${state.modifier}`,
-      );
 
       if (rpcHidReady) {
         console.debug("Sending keyboard report via HidRPC");
@@ -68,33 +60,31 @@ export default function useKeyboard() {
         return;
       }
 
-      send(
+      send("keyboardReport", { keys: state.keys, modifier: state.modifier }, (resp: JsonRpcResponse) => {
-        "keyboardReport",
+        if ("error" in resp) {
-        { keys: state.keys, modifier: state.modifier },
+          console.error(`Failed to send keyboard report ${state}`, resp.error);
-        (resp: JsonRpcResponse) => {
+        }
-          if ("error" in resp) {
+      });
-            console.error(`Failed to send keyboard report ${state}`, resp.error);
-          }
-        },
-      );
     },
-    [rpcDataChannel?.readyState, rpcHidReady, send, sendKeyboardEventHidRpc],
+    [
+      rpcDataChannel?.readyState,
+      rpcHidReady,
+      send,
+      sendKeyboardEventHidRpc,
+    ],
   );
 
+
   // executeMacro is used to execute a macro consisting of multiple steps.
   // Each step can have multiple keys, multiple modifiers and a delay.
   // The keys and modifiers are pressed together and held for the delay duration.
   // After the delay, the keys and modifiers are released and the next step is executed.
   // If a step has no keys or modifiers, it is treated as a delay-only step.
   // A small pause is added between steps to ensure that the device can process the events.
-  const executeMacro = async (
+  const executeMacro = async (steps: { keys: string[] | null; modifiers: string[] | null; delay: number }[]) => {
-    steps: { keys: string[] | null; modifiers: string[] | null; delay: number }[],
-  ) => {
     for (const [index, step] of steps.entries()) {
       const keyValues = (step.keys || []).map(key => keys[key]).filter(Boolean);
-      const modifierMask: number = (step.modifiers || [])
+      const modifierMask: number = (step.modifiers || []).map(mod => modifiers[mod]).reduce((acc, val) => acc + val, 0);
-        .map(mod => modifiers[mod])
-        .reduce((acc, val) => acc + val, 0);
 
       // If the step has keys and/or modifiers, press them and hold for the delay
       if (keyValues.length > 0 || modifierMask > 0) {
@@ -129,8 +119,6 @@ export default function useKeyboard() {
       clearInterval(keepAliveTimerRef.current);
     }
 
-    sendKeypressKeepAliveHidRpc();
-
     // Create new interval timer
     keepAliveTimerRef.current = setInterval(() => {
       sendKeypressKeepAliveHidRpc();
@@ -186,11 +174,7 @@ export default function useKeyboard() {
         sendKeypress(key, press);
       } else {
         // if the keyPress api is not available, we need to handle the key locally
-        const downState = simulateDeviceSideKeyHandlingForLegacyDevices(
+        const downState = simulateDeviceSideKeyHandlingForLegacyDevices(keysDownState, key, press);
-          keysDownState,
-          key,
-          press,
-        );
         sendKeyboardEvent(downState); // then we send the full state
 
         // if we just sent ErrorRollOver, reset to empty state
@@ -210,11 +194,7 @@ export default function useKeyboard() {
   );
 
   // IMPORTANT: See the keyPressReportApiAvailable comment above for the reason this exists
-  function simulateDeviceSideKeyHandlingForLegacyDevices(
+  function simulateDeviceSideKeyHandlingForLegacyDevices(state: KeysDownState, key: number, press: boolean): KeysDownState {
-    state: KeysDownState,
-    key: number,
-    press: boolean,
-  ): KeysDownState {
     // IMPORTANT: This code parallels the logic in the kernel's hid-gadget driver
     // for handling key presses and releases. It ensures that the USB gadget
     // behaves similarly to a real USB HID keyboard. This logic is paralleled
@@ -243,7 +223,7 @@ export default function useKeyboard() {
         // and if we find a zero byte, we can place the key there (if press is true)
         if (keys[i] === key || keys[i] === 0) {
           if (press) {
-            keys[i] = key; // overwrites the zero byte or the same key if already pressed
+            keys[i] = key // overwrites the zero byte or the same key if already pressed
           } else {
             // we are releasing the key, remove it from the buffer
             if (keys[i] !== 0) {
@@ -259,15 +239,13 @@ export default function useKeyboard() {
       // If we reach here it means we didn't find an empty slot or the key in the buffer
       if (overrun) {
         if (press) {
-          console.warn(
+          console.warn(`keyboard buffer overflow current keys ${keys}, key: ${key} not added`);
-            `keyboard buffer overflow current keys ${keys}, key: ${key} not added`,
-          );
           // Fill all key slots with ErrorRollOver (0x01) to indicate overflow
           keys.length = hidKeyBufferSize;
           keys.fill(hidErrorRollOver);
         } else {
           // If we are releasing a key, and we didn't find it in a slot, who cares?
-          console.debug(`key ${key} not found in buffer, nothing to release`);
+          console.debug(`key ${key} not found in buffer, nothing to release`)
         }
       }
     }

usb.go

@@ -33,7 +33,7 @@ func initUsbGadget() {
 
 	gadget.SetOnKeysDownChange(func(state usbgadget.KeysDownState) {
 		if currentSession != nil {
-			currentSession.enqueueKeysDownState(state)
+			currentSession.reportHidRPCKeysDownState(state)
 		}
 	})
 
@@ -43,11 +43,11 @@ func initUsbGadget() {
 	}
 }
 
-func rpcKeyboardReport(modifier byte, keys []byte) error {
+func rpcKeyboardReport(modifier byte, keys []byte) (usbgadget.KeysDownState, error) {
 	return gadget.KeyboardReport(modifier, keys)
 }
 
-func rpcKeypressReport(key byte, press bool) error {
+func rpcKeypressReport(key byte, press bool) (usbgadget.KeysDownState, error) {
 	return gadget.KeypressReport(key, press)
 }
 

webrtc.go

@@ -13,7 +13,6 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/jetkvm/kvm/internal/hidrpc"
 	"github.com/jetkvm/kvm/internal/logging"
-	"github.com/jetkvm/kvm/internal/usbgadget"
 	"github.com/pion/webrtc/v4"
 	"github.com/rs/zerolog"
 )
@@ -31,8 +30,6 @@ type Session struct {
 	hidRPCAvailable bool
 	hidQueueLock    sync.Mutex
 	hidQueue        []chan hidQueueMessage
-
-	keysDownStateQueue chan usbgadget.KeysDownState
 }
 
 type hidQueueMessage struct {
@@ -99,32 +96,6 @@ func (s *Session) handleQueues(index int) {
 	}
 }
 
-const keysDownStateQueueSize = 256
-
-func (s *Session) initKeysDownStateQueue() {
-	// serialise outbound key state reports so unreliable links can't stall input handling
-	s.keysDownStateQueue = make(chan usbgadget.KeysDownState, keysDownStateQueueSize)
-	go s.handleKeysDownStateQueue()
-}
-
-func (s *Session) handleKeysDownStateQueue() {
-	for state := range s.keysDownStateQueue {
-		s.reportHidRPCKeysDownState(state)
-	}
-}
-
-func (s *Session) enqueueKeysDownState(state usbgadget.KeysDownState) {
-	if s == nil || s.keysDownStateQueue == nil {
-		return
-	}
-
-	select {
-	case s.keysDownStateQueue <- state:
-	default:
-		hidRPCLogger.Warn().Msg("dropping keys down state update; queue full")
-	}
-}
-
 func getOnHidMessageHandler(session *Session, scopedLogger *zerolog.Logger, channel string) func(msg webrtc.DataChannelMessage) {
 	return func(msg webrtc.DataChannelMessage) {
 		l := scopedLogger.With().
@@ -210,7 +181,6 @@ func newSession(config SessionConfig) (*Session, error) {
 	session := &Session{peerConnection: peerConnection}
 	session.rpcQueue = make(chan webrtc.DataChannelMessage, 256)
 	session.initQueues()
-	session.initKeysDownStateQueue()
 
 	go func() {
 		for msg := range session.rpcQueue {