fixed permission on created devices

internal/client/socket_linux.go

@@ -4,7 +4,10 @@ package client
 
 import (
 	"fmt"
+	"log"
 	"os"
+	"path/filepath"
+	"time"
 
 	"golang.org/x/sys/unix"
 )
@@ -26,3 +29,55 @@ func closeFDs(fds [2]int) {
 func fdToFile(fd int, name string) *os.File {
 	return os.NewFile(uintptr(fd), name)
 }
+
+// fixVHCIDevicePermissions waits for the VHCI-attached device to create
+// device nodes (e.g. /dev/video*) and sets them to world-accessible.
+// VHCI-created devices don't get normal udev rules applied, so they
+// default to root-only access.
+func fixVHCIDevicePermissions(port int) {
+	// Wait for the device to finish enumerating and create device nodes
+	// The kernel needs time to enumerate descriptors and bind drivers
+	for attempt := 0; attempt < 10; attempt++ {
+		time.Sleep(500 * time.Millisecond)
+
+		// Find device nodes created by this VHCI port
+		// VHCI creates devices under /sys/devices/platform/vhci_hcd.0/usbN/
+		// We look for video4linux devices
+		matches, _ := filepath.Glob("/sys/devices/platform/vhci_hcd.0/usb*/*/video4linux/video*")
+		for _, m := range matches {
+			devName := filepath.Base(m)
+			devPath := "/dev/" + devName
+			if _, err := os.Stat(devPath); err == nil {
+				if err := os.Chmod(devPath, 0666); err == nil {
+					log.Printf("[use] set permissions 0666 on %s", devPath)
+				}
+			}
+		}
+
+		// Also check for other common device types (input, sound, etc.)
+		for _, subsys := range []string{"sound/card*", "input/input*/event*"} {
+			sysMatches, _ := filepath.Glob("/sys/devices/platform/vhci_hcd.0/usb*/*/" + subsys)
+			for _, m := range sysMatches {
+				devName := filepath.Base(m)
+				devPath := "/dev/" + devName
+				// For sound devices, also check /dev/snd/
+				if _, err := os.Stat(devPath); err == nil {
+					os.Chmod(devPath, 0666)
+				}
+				devPath = "/dev/snd/" + devName
+				if _, err := os.Stat(devPath); err == nil {
+					os.Chmod(devPath, 0666)
+				}
+			}
+		}
+
+		if attempt == 0 {
+			continue // first iteration: always wait more
+		}
+
+		// Check if we found any video devices
+		if len(matches) > 0 {
+			return
+		}
+	}
+}

internal/client/socket_windows.go

@@ -16,3 +16,7 @@ func closeFDs(fds [2]int) {}
 func fdToFile(fd int, name string) *os.File {
 	return nil
 }
+
+func fixVHCIDevicePermissions(port int) {
+	// Not applicable on Windows
+}

internal/client/use.go

@@ -132,7 +132,10 @@ func (um *UseManager) AttachDevice(clientID, busID string) error {
 
 	// Wait for response (with timeout via context)
 	select {
-	case granted := <-respChan:
+	case granted, ok := <-respChan:
+		if !ok || granted == nil {
+			return fmt.Errorf("device request denied")
+		}
 		return um.setupVHCI(clientID, busID, granted)
 	case <-um.client.ctx.Done():
 		return fmt.Errorf("client shutting down")
@@ -239,6 +242,11 @@ func (um *UseManager) setupVHCI(clientID, busID string, granted *protocol.Device
 	go um.tunnelReadLoop(tunnel)
 
 	log.Printf("[use] device %s attached on VHCI port %d", key, port)
+
+	// Fix permissions on newly created device nodes (e.g. /dev/video*)
+	// VHCI-created devices don't get normal udev permissions
+	go fixVHCIDevicePermissions(port)
+
 	return nil
 }