Add USB/IP support

app/src/main/AndroidManifest.xml

@@ -7,10 +7,15 @@
         android:name="android.hardware.camera"
         android:required="false" />
 
+    <uses-feature
+        android:name="android.hardware.usb.host"
+        android:required="false" />
+
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SYSTEM_EXEMPTED" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SPECIAL_USE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_CONNECTED_DEVICE" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
@@ -142,6 +147,10 @@
                 android:name="android.app.PROPERTY_SPECIAL_USE_FGS_SUBTYPE"
                 android:value="proxy" />
         </service>
+        <service
+            android:name=".bg.USBIPService"
+            android:exported="false"
+            android:foregroundServiceType="connectedDevice" />
 
         <receiver
             android:name=".bg.BootReceiver"

app/src/main/java/io/nekohasekai/sfa/bg/USBIPService.kt

@@ -0,0 +1,146 @@
+package io.nekohasekai.sfa.bg
+
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.app.Service
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.content.pm.ServiceInfo
+import android.hardware.usb.UsbDevice
+import android.hardware.usb.UsbManager
+import android.os.Build
+import android.os.IBinder
+import androidx.core.app.NotificationCompat
+import androidx.core.app.ServiceCompat
+import androidx.core.content.ContextCompat
+import androidx.core.content.IntentCompat
+import io.nekohasekai.sfa.Application
+import io.nekohasekai.sfa.R
+import io.nekohasekai.sfa.compose.MainActivity
+import io.nekohasekai.sfa.usbip.USBIPManager
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.launch
+
+class USBIPService : Service() {
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Main)
+    private var collectJob: Job? = null
+    private var receiverRegistered = false
+
+    private val detachReceiver =
+        object : BroadcastReceiver() {
+            override fun onReceive(context: Context, intent: Intent) {
+                if (intent.action != UsbManager.ACTION_USB_DEVICE_DETACHED) return
+                val device = IntentCompat.getParcelableExtra(intent, UsbManager.EXTRA_DEVICE, UsbDevice::class.java) ?: return
+                USBIPManager.detachByDevice(device)
+            }
+        }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        if (intent?.action == ACTION_STOP) {
+            USBIPManager.shutdown()
+            stopSelf()
+            return START_NOT_STICKY
+        }
+        createChannel()
+        ServiceCompat.startForeground(
+            this,
+            NOTIFICATION_ID,
+            buildNotification(USBIPManager.state.value.devices.size),
+            foregroundServiceType(),
+        )
+        registerDetachReceiver()
+        if (collectJob == null) {
+            collectJob =
+                scope.launch {
+                    USBIPManager.state.collect { state ->
+                        if (state.devices.isEmpty()) {
+                            stopSelf()
+                        } else {
+                            Application.notificationManager.notify(NOTIFICATION_ID, buildNotification(state.devices.size))
+                        }
+                    }
+                }
+        }
+        return START_STICKY
+    }
+
+    private fun registerDetachReceiver() {
+        if (receiverRegistered) return
+        ContextCompat.registerReceiver(
+            this,
+            detachReceiver,
+            IntentFilter(UsbManager.ACTION_USB_DEVICE_DETACHED),
+            ContextCompat.RECEIVER_NOT_EXPORTED,
+        )
+        receiverRegistered = true
+    }
+
+    private fun createChannel() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return
+        Application.notification.createNotificationChannel(
+            NotificationChannel(NOTIFICATION_CHANNEL, "USB/IP", NotificationManager.IMPORTANCE_LOW),
+        )
+    }
+
+    private fun buildNotification(count: Int) = NotificationCompat.Builder(this, NOTIFICATION_CHANNEL)
+        .setShowWhen(false)
+        .setOngoing(true)
+        .setOnlyAlertOnce(true)
+        .setSmallIcon(R.drawable.ic_menu)
+        .setCategory(NotificationCompat.CATEGORY_SERVICE)
+        .setPriority(NotificationCompat.PRIORITY_LOW)
+        .setContentTitle(getString(R.string.usbip_notification_title))
+        .setContentText(resources.getQuantityString(R.plurals.usbip_notification_text, count, count))
+        .setContentIntent(
+            PendingIntent.getActivity(
+                this,
+                0,
+                Intent(this, MainActivity::class.java).setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT),
+                pendingIntentFlags(),
+            ),
+        )
+        .addAction(
+            NotificationCompat.Action.Builder(
+                0,
+                getText(R.string.stop),
+                PendingIntent.getService(
+                    this,
+                    0,
+                    Intent(this, USBIPService::class.java).setAction(ACTION_STOP),
+                    pendingIntentFlags(),
+                ),
+            ).build(),
+        )
+        .build()
+
+    override fun onDestroy() {
+        super.onDestroy()
+        collectJob?.cancel()
+        collectJob = null
+        if (receiverRegistered) {
+            unregisterReceiver(detachReceiver)
+            receiverRegistered = false
+        }
+        scope.cancel()
+        USBIPManager.onServiceDestroyed()
+    }
+
+    companion object {
+        const val ACTION_STOP = "io.nekohasekai.sfa.action.USBIP_STOP"
+        private const val NOTIFICATION_ID = 2
+        private const val NOTIFICATION_CHANNEL = "usbip"
+
+        private fun pendingIntentFlags() = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) PendingIntent.FLAG_IMMUTABLE else 0
+
+        private fun foregroundServiceType() = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) ServiceInfo.FOREGROUND_SERVICE_TYPE_CONNECTED_DEVICE else 0
+    }
+}

app/src/main/java/io/nekohasekai/sfa/compose/MainActivity.kt

@@ -118,6 +118,7 @@ import io.nekohasekai.sfa.compose.screen.dashboard.groups.GroupsViewModel
 import io.nekohasekai.sfa.compose.screen.log.LogViewModel
 import io.nekohasekai.sfa.compose.screen.tools.TailscaleSSHSharedViewModel
 import io.nekohasekai.sfa.compose.screen.tools.TailscaleStatusViewModel
+import io.nekohasekai.sfa.compose.screen.usbip.USBIPStatusViewModel
 import io.nekohasekai.sfa.compose.theme.SFATheme
 import io.nekohasekai.sfa.compose.topbar.LocalTopBarController
 import io.nekohasekai.sfa.compose.topbar.TopBarController
@@ -768,6 +769,13 @@ class MainActivity :
                 null
             }
 
+        val usbIPStatusViewModel: USBIPStatusViewModel? =
+            if (isToolsRoute) {
+                viewModel()
+            } else {
+                null
+            }
+
         val showGroupsInNav = dashboardUiState.hasGroups
         val showConnectionsInNav =
             if (isRemote) {
@@ -895,6 +903,7 @@ class MainActivity :
                     connectionsViewModel = connectionsViewModel,
                     tailscaleStatusViewModel = tailscaleStatusViewModel,
                     tailscaleSSHSharedViewModel = tailscaleSSHSharedViewModel,
+                    usbIPStatusViewModel = usbIPStatusViewModel,
                     modifier = Modifier.fillMaxSize(),
                 )
                 if (!useNavigationRail) {

app/src/main/java/io/nekohasekai/sfa/compose/navigation/SFANavigation.kt

@@ -58,6 +58,9 @@ import io.nekohasekai.sfa.compose.screen.tools.TailscaleSSHSharedViewModel
 import io.nekohasekai.sfa.compose.screen.tools.TailscaleSSHTerminalScreen
 import io.nekohasekai.sfa.compose.screen.tools.TailscaleStatusViewModel
 import io.nekohasekai.sfa.compose.screen.tools.ToolsScreen
+import io.nekohasekai.sfa.compose.screen.usbip.USBIPDeviceDetailScreen
+import io.nekohasekai.sfa.compose.screen.usbip.USBIPServerScreen
+import io.nekohasekai.sfa.compose.screen.usbip.USBIPStatusViewModel
 import io.nekohasekai.sfa.constant.Status
 
 private val slideInFromRight: AnimatedContentTransitionScope<*>.() -> androidx.compose.animation.EnterTransition = {
@@ -91,6 +94,7 @@ fun SFANavHost(
     connectionsViewModel: ConnectionsViewModel? = null,
     tailscaleStatusViewModel: TailscaleStatusViewModel? = null,
     tailscaleSSHSharedViewModel: TailscaleSSHSharedViewModel? = null,
+    usbIPStatusViewModel: USBIPStatusViewModel? = null,
     modifier: Modifier = Modifier,
 ) {
     NavHost(
@@ -240,7 +244,8 @@ fun SFANavHost(
         composable(Screen.Tools.route) {
             val tailscaleViewModel: TailscaleStatusViewModel = tailscaleStatusViewModel ?: viewModel()
             val sshSharedViewModel: TailscaleSSHSharedViewModel = tailscaleSSHSharedViewModel ?: viewModel()
-            ToolsScreen(navController = navController, serviceStatus = serviceStatus, tailscaleViewModel = tailscaleViewModel, sshSharedViewModel = sshSharedViewModel)
+            val usbIPViewModel: USBIPStatusViewModel = usbIPStatusViewModel ?: viewModel()
+            ToolsScreen(navController = navController, serviceStatus = serviceStatus, tailscaleViewModel = tailscaleViewModel, sshSharedViewModel = sshSharedViewModel, usbIPViewModel = usbIPViewModel)
         }
 
         // Tools subscreens with slide animations
@@ -264,6 +269,36 @@ fun SFANavHost(
             STUNTestScreen(navController = navController, serviceStatus = serviceStatus)
         }
 
+        composable(
+            route = "tools/usbip/{serverTag}",
+            arguments = listOf(navArgument("serverTag") { type = NavType.StringType }),
+            enterTransition = slideInFromRight,
+            exitTransition = slideOutToLeft,
+            popEnterTransition = slideInFromLeft,
+            popExitTransition = slideOutToRight,
+        ) { backStackEntry ->
+            val serverTag = Uri.decode(backStackEntry.arguments?.getString("serverTag") ?: return@composable)
+            val usbIPViewModel: USBIPStatusViewModel = usbIPStatusViewModel ?: viewModel()
+            USBIPServerScreen(navController = navController, viewModel = usbIPViewModel, serverTag = serverTag)
+        }
+
+        composable(
+            route = "tools/usbip/{serverTag}/device/{deviceKey}",
+            arguments = listOf(
+                navArgument("serverTag") { type = NavType.StringType },
+                navArgument("deviceKey") { type = NavType.StringType },
+            ),
+            enterTransition = slideInFromRight,
+            exitTransition = slideOutToLeft,
+            popEnterTransition = slideInFromLeft,
+            popExitTransition = slideOutToRight,
+        ) { backStackEntry ->
+            val serverTag = Uri.decode(backStackEntry.arguments?.getString("serverTag") ?: return@composable)
+            val deviceKey = Uri.decode(backStackEntry.arguments?.getString("deviceKey") ?: return@composable)
+            val usbIPViewModel: USBIPStatusViewModel = usbIPStatusViewModel ?: viewModel()
+            USBIPDeviceDetailScreen(navController = navController, viewModel = usbIPViewModel, serverTag = serverTag, deviceKey = deviceKey)
+        }
+
         composable(
             route = "tools/outbound_picker/{selectedOutbound}",
             arguments = listOf(navArgument("selectedOutbound") { type = NavType.StringType }),

app/src/main/java/io/nekohasekai/sfa/compose/screen/settings/EditRemoteServerScreen.kt

@@ -2,11 +2,15 @@ package io.nekohasekai.sfa.compose.screen.settings
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
@@ -14,6 +18,7 @@ import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.Visibility
 import androidx.compose.material.icons.filled.VisibilityOff
 import androidx.compose.material3.Button
+import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
@@ -28,21 +33,30 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.text.input.PasswordVisualTransformation
 import androidx.compose.ui.text.input.VisualTransformation
 import androidx.compose.ui.unit.dp
 import androidx.navigation.NavController
+import io.nekohasekai.libbox.Libbox
+import io.nekohasekai.libbox.RemoteConnectionOptions
 import io.nekohasekai.sfa.R
+import io.nekohasekai.sfa.compose.theme.ServiceError
+import io.nekohasekai.sfa.compose.theme.ServiceRunning
 import io.nekohasekai.sfa.compose.topbar.OverrideTopBar
 import io.nekohasekai.sfa.database.RemoteServer
 import io.nekohasekai.sfa.database.RemoteServerManager
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 
+private enum class ProbeState { Idle, Checking, Available, Unavailable }
+
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun EditRemoteServerScreen(navController: NavController, serverId: Long = -1L) {
@@ -80,6 +94,35 @@ fun EditRemoteServerScreen(navController: NavController, serverId: Long = -1L) {
     var secretVisible by remember { mutableStateOf(false) }
     var urlError by remember { mutableStateOf(false) }
     var isLoading by remember { mutableStateOf(!isNewServer) }
+    var probeState by remember { mutableStateOf(ProbeState.Idle) }
+    var userEdited by remember { mutableStateOf(false) }
+
+    LaunchedEffect(url, secret) {
+        if (RemoteServer.validateURL(url) == null) {
+            probeState = ProbeState.Idle
+            return@LaunchedEffect
+        }
+        probeState = ProbeState.Checking
+        if (userEdited) {
+            delay(300)
+        }
+        val reachable = withContext(Dispatchers.IO) {
+            var client: io.nekohasekai.libbox.CommandClient? = null
+            try {
+                val options = RemoteConnectionOptions()
+                options.setURL(RemoteServer.connectURL(url))
+                options.secret = secret
+                client = Libbox.newStandaloneRemoteCommandClient(options)
+                client.getStartedAt()
+                true
+            } catch (_: Exception) {
+                false
+            } finally {
+                runCatching { client?.disconnect() }
+            }
+        }
+        probeState = if (reachable) ProbeState.Available else ProbeState.Unavailable
+    }
 
     LaunchedEffect(serverId) {
         if (!isNewServer) {
@@ -90,7 +133,7 @@ fun EditRemoteServerScreen(navController: NavController, serverId: Long = -1L) {
             }
             origin = server
             name = server.name
-            url = server.url
+            url = RemoteServer.normalizeURL(server.url)
             secret = server.secret
             isLoading = false
         }
@@ -123,6 +166,7 @@ fun EditRemoteServerScreen(navController: NavController, serverId: Long = -1L) {
             onValueChange = {
                 url = it
                 urlError = false
+                userEdited = true
             },
             modifier = Modifier.fillMaxWidth(),
             label = { Text(stringResource(R.string.profile_url)) },
@@ -140,7 +184,10 @@ fun EditRemoteServerScreen(navController: NavController, serverId: Long = -1L) {
 
         OutlinedTextField(
             value = secret,
-            onValueChange = { secret = it },
+            onValueChange = {
+                secret = it
+                userEdited = true
+            },
             modifier = Modifier.fillMaxWidth(),
             label = { Text(stringResource(R.string.remote_secret)) },
             placeholder = { Text(stringResource(R.string.remote_optional)) },
@@ -167,6 +214,51 @@ fun EditRemoteServerScreen(navController: NavController, serverId: Long = -1L) {
             keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Password),
         )
 
+        if (probeState != ProbeState.Idle) {
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
+                horizontalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                if (probeState == ProbeState.Checking) {
+                    CircularProgressIndicator(
+                        modifier = Modifier.size(16.dp),
+                        strokeWidth = 2.dp,
+                    )
+                } else {
+                    Box(
+                        modifier =
+                        Modifier
+                            .size(8.dp)
+                            .clip(CircleShape)
+                            .background(
+                                if (probeState == ProbeState.Available) {
+                                    ServiceRunning
+                                } else {
+                                    ServiceError
+                                },
+                            ),
+                    )
+                }
+                Text(
+                    text =
+                    stringResource(
+                        when (probeState) {
+                            ProbeState.Available -> R.string.remote_available
+                            ProbeState.Checking -> R.string.remote_checking
+                            else -> R.string.remote_unavailable
+                        },
+                    ),
+                    color =
+                    when (probeState) {
+                        ProbeState.Available -> ServiceRunning
+                        ProbeState.Unavailable -> ServiceError
+                        else -> MaterialTheme.colorScheme.onSurfaceVariant
+                    },
+                    style = MaterialTheme.typography.bodySmall,
+                )
+            }
+        }
+
         Button(
             onClick = {
                 val validatedURL = RemoteServer.validateURL(url)

app/src/main/java/io/nekohasekai/sfa/compose/screen/settings/RemoteControlScreen.kt

@@ -5,9 +5,12 @@ import androidx.compose.foundation.background
 import androidx.compose.foundation.combinedClickable
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
@@ -16,7 +19,9 @@ import androidx.compose.material.icons.automirrored.filled.ArrowBack
 import androidx.compose.material.icons.filled.CheckCircle
 import androidx.compose.material.icons.outlined.Add
 import androidx.compose.material.icons.outlined.Delete
+import androidx.compose.material.icons.outlined.Dns
 import androidx.compose.material.icons.outlined.Edit
+import androidx.compose.material.icons.outlined.SettingsRemote
 import androidx.compose.material3.Card
 import androidx.compose.material3.CardDefaults
 import androidx.compose.material3.DropdownMenu
@@ -43,6 +48,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import androidx.navigation.NavController
 import io.nekohasekai.sfa.R
@@ -98,6 +104,34 @@ fun RemoteControlScreen(navController: NavController) {
         }
     }
 
+    if (servers.isEmpty()) {
+        Box(
+            modifier =
+            Modifier
+                .fillMaxSize()
+                .background(MaterialTheme.colorScheme.surface)
+                .padding(32.dp),
+            contentAlignment = Alignment.Center,
+        ) {
+            Column(horizontalAlignment = Alignment.CenterHorizontally) {
+                Icon(
+                    imageVector = Icons.Outlined.SettingsRemote,
+                    contentDescription = null,
+                    modifier = Modifier.size(48.dp),
+                    tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+                Spacer(modifier = Modifier.height(16.dp))
+                Text(
+                    text = stringResource(R.string.remote_no_servers),
+                    style = MaterialTheme.typography.bodyLarge,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    textAlign = TextAlign.Center,
+                )
+            }
+        }
+        return
+    }
+
     Column(
         modifier =
         Modifier
@@ -106,134 +140,125 @@ fun RemoteControlScreen(navController: NavController) {
             .verticalScroll(rememberScrollState())
             .padding(vertical = 8.dp),
     ) {
-        Text(
-            text = stringResource(R.string.remote_servers),
-            style = MaterialTheme.typography.labelLarge,
-            color = MaterialTheme.colorScheme.primary,
-            modifier = Modifier.padding(horizontal = 32.dp, vertical = 8.dp),
-        )
+        Card(
+            modifier =
+            Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 16.dp, vertical = 8.dp),
+            colors =
+            CardDefaults.cardColors(
+                containerColor = MaterialTheme.colorScheme.surfaceContainer,
+            ),
+        ) {
+            Column {
+                servers.forEachIndexed { index, server ->
+                    val shape =
+                        when {
+                            servers.size == 1 -> RoundedCornerShape(12.dp)
+                            index == 0 -> RoundedCornerShape(topStart = 12.dp, topEnd = 12.dp)
+                            index == servers.size - 1 ->
+                                RoundedCornerShape(bottomStart = 12.dp, bottomEnd = 12.dp)
 
-        if (servers.isEmpty()) {
-            Text(
-                text = stringResource(R.string.remote_no_servers),
-                style = MaterialTheme.typography.bodyLarge,
-                color = MaterialTheme.colorScheme.onSurfaceVariant,
-                modifier = Modifier.padding(horizontal = 32.dp, vertical = 16.dp),
-            )
-        } else {
-            Card(
-                modifier =
-                Modifier
-                    .fillMaxWidth()
-                    .padding(horizontal = 16.dp),
-                colors =
-                CardDefaults.cardColors(
-                    containerColor = MaterialTheme.colorScheme.surfaceContainer,
-                ),
-            ) {
-                Column {
-                    servers.forEachIndexed { index, server ->
-                        val shape =
-                            when {
-                                servers.size == 1 -> RoundedCornerShape(12.dp)
-                                index == 0 -> RoundedCornerShape(topStart = 12.dp, topEnd = 12.dp)
-                                index == servers.size - 1 ->
-                                    RoundedCornerShape(bottomStart = 12.dp, bottomEnd = 12.dp)
-
-                                else -> RoundedCornerShape(0.dp)
-                            }
-                        var showMenu by remember { mutableStateOf(false) }
-                        Box {
-                            ListItem(
-                                headlineContent = {
+                            else -> RoundedCornerShape(0.dp)
+                        }
+                    var showMenu by remember { mutableStateOf(false) }
+                    Box {
+                        ListItem(
+                            headlineContent = {
+                                Text(
+                                    server.displayName,
+                                    style = MaterialTheme.typography.bodyLarge,
+                                )
+                            },
+                            supportingContent =
+                            if (server.name.isNotEmpty()) {
+                                {
                                     Text(
-                                        server.displayName,
-                                        style = MaterialTheme.typography.bodyLarge,
+                                        server.url,
+                                        style = MaterialTheme.typography.bodyMedium,
+                                        color = MaterialTheme.colorScheme.onSurfaceVariant,
                                     )
-                                },
-                                supportingContent =
-                                if (server.name.isNotEmpty()) {
-                                    {
-                                        Text(
-                                            server.url,
-                                            style = MaterialTheme.typography.bodySmall,
-                                            color = MaterialTheme.colorScheme.onSurfaceVariant,
-                                        )
-                                    }
-                                } else {
-                                    null
-                                },
-                                trailingContent =
-                                if (activeRemoteServer?.id == server.id) {
-                                    {
-                                        Icon(
-                                            imageVector = Icons.Default.CheckCircle,
-                                            contentDescription = null,
-                                            tint = MaterialTheme.colorScheme.primary,
-                                        )
-                                    }
-                                } else {
-                                    null
-                                },
-                                modifier =
-                                Modifier
-                                    .clip(shape)
-                                    .combinedClickable(
-                                        onClick = {
-                                            navController.navigate(
-                                                "settings/remote_control/edit/${server.id}",
-                                            )
-                                        },
-                                        onLongClick = { showMenu = true },
-                                    ),
-                                colors =
-                                ListItemDefaults.colors(
-                                    containerColor = Color.Transparent,
-                                ),
-                            )
-                            DropdownMenu(
-                                expanded = showMenu,
-                                onDismissRequest = { showMenu = false },
-                            ) {
-                                DropdownMenuItem(
-                                    text = { Text(stringResource(R.string.edit)) },
-                                    leadingIcon = {
-                                        Icon(Icons.Outlined.Edit, contentDescription = null)
-                                    },
+                                }
+                            } else {
+                                null
+                            },
+                            leadingContent = {
+                                Icon(
+                                    imageVector = Icons.Outlined.Dns,
+                                    contentDescription = null,
+                                    tint = MaterialTheme.colorScheme.primary,
+                                )
+                            },
+                            trailingContent =
+                            if (activeRemoteServer?.id == server.id) {
+                                {
+                                    Icon(
+                                        imageVector = Icons.Default.CheckCircle,
+                                        contentDescription = null,
+                                        tint = MaterialTheme.colorScheme.primary,
+                                    )
+                                }
+                            } else {
+                                null
+                            },
+                            modifier =
+                            Modifier
+                                .clip(shape)
+                                .combinedClickable(
                                     onClick = {
-                                        showMenu = false
                                         navController.navigate(
                                             "settings/remote_control/edit/${server.id}",
                                         )
                                     },
-                                )
-                                DropdownMenuItem(
-                                    text = {
-                                        Text(
-                                            stringResource(R.string.menu_delete),
-                                            color = MaterialTheme.colorScheme.error,
-                                        )
-                                    },
-                                    leadingIcon = {
-                                        Icon(
-                                            Icons.Outlined.Delete,
-                                            contentDescription = null,
-                                            tint = MaterialTheme.colorScheme.error,
-                                        )
-                                    },
-                                    onClick = {
-                                        showMenu = false
-                                        scope.launch(Dispatchers.IO) {
-                                            if (RemoteControlManager.remoteServer.value?.id == server.id) {
-                                                withContext(Dispatchers.Main) {
-                                                    RemoteControlManager.exitRemoteControl()
-                                                }
+                                    onLongClick = { showMenu = true },
+                                ),
+                            colors =
+                            ListItemDefaults.colors(
+                                containerColor = Color.Transparent,
+                            ),
+                        )
+                        DropdownMenu(
+                            expanded = showMenu,
+                            onDismissRequest = { showMenu = false },
+                        ) {
+                            DropdownMenuItem(
+                                text = { Text(stringResource(R.string.edit)) },
+                                leadingIcon = {
+                                    Icon(Icons.Outlined.Edit, contentDescription = null)
+                                },
+                                onClick = {
+                                    showMenu = false
+                                    navController.navigate(
+                                        "settings/remote_control/edit/${server.id}",
+                                    )
+                                },
+                            )
+                            DropdownMenuItem(
+                                text = {
+                                    Text(
+                                        stringResource(R.string.menu_delete),
+                                        color = MaterialTheme.colorScheme.error,
+                                    )
+                                },
+                                leadingIcon = {
+                                    Icon(
+                                        Icons.Outlined.Delete,
+                                        contentDescription = null,
+                                        tint = MaterialTheme.colorScheme.error,
+                                    )
+                                },
+                                onClick = {
+                                    showMenu = false
+                                    scope.launch(Dispatchers.IO) {
+                                        if (RemoteControlManager.remoteServer.value?.id == server.id) {
+                                            withContext(Dispatchers.Main) {
+                                                RemoteControlManager.exitRemoteControl()
                                             }
-                                            RemoteServerManager.delete(server)
                                         }
-                                    },
-                                )
-                            }
+                                        RemoteServerManager.delete(server)
+                                    }
+                                },
+                            )
                         }
                     }
                 }

app/src/main/java/io/nekohasekai/sfa/compose/screen/tools/TailscaleEndpointScreen.kt

@@ -73,9 +73,20 @@ fun TailscaleEndpointScreen(
     sshSharedViewModel: TailscaleSSHSharedViewModel,
     endpointTag: String,
 ) {
+    val state by viewModel.uiState.collectAsState()
+    val endpoint = state.endpoints.firstOrNull { it.endpointTag == endpointTag }
+
     OverrideTopBar {
         TopAppBar(
-            title = { Text(endpointTag) },
+            title = {
+                Text(
+                    if (state.endpoints.size <= 1) {
+                        stringResource(R.string.tailscale)
+                    } else {
+                        stringResource(R.string.tailscale_with_tag, endpointTag)
+                    },
+                )
+            },
             navigationIcon = {
                 IconButton(onClick = { navController.navigateUp() }) {
                     Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = stringResource(R.string.content_description_back))
@@ -84,9 +95,6 @@ fun TailscaleEndpointScreen(
         )
     }
 
-    val state by viewModel.uiState.collectAsState()
-    val endpoint = state.endpoints.firstOrNull { it.endpointTag == endpointTag }
-
     if (endpoint == null) {
         LaunchedEffect(Unit) {
             navController.navigateUp()

app/src/main/java/io/nekohasekai/sfa/compose/screen/tools/ToolsScreen.kt

@@ -16,6 +16,7 @@ import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.MoreVert
 import androidx.compose.material.icons.filled.Terminal
+import androidx.compose.material.icons.filled.Usb
 import androidx.compose.material.icons.outlined.BugReport
 import androidx.compose.material.icons.outlined.Hub
 import androidx.compose.material.icons.outlined.Memory
@@ -53,6 +54,7 @@ import io.nekohasekai.sfa.bg.CrashReportManager
 import io.nekohasekai.sfa.bg.OOMReportManager
 import io.nekohasekai.sfa.compose.component.RemoteControlMenuItems
 import io.nekohasekai.sfa.compose.component.rememberRemoteServers
+import io.nekohasekai.sfa.compose.screen.usbip.USBIPStatusViewModel
 import io.nekohasekai.sfa.compose.topbar.OverrideTopBar
 import io.nekohasekai.sfa.constant.Status
 import io.nekohasekai.sfa.database.Settings
@@ -66,6 +68,7 @@ fun ToolsScreen(
     serviceStatus: Status = Status.Stopped,
     tailscaleViewModel: TailscaleStatusViewModel,
     sshSharedViewModel: TailscaleSSHSharedViewModel,
+    usbIPViewModel: USBIPStatusViewModel,
 ) {
     val remoteServers by rememberRemoteServers()
 
@@ -101,6 +104,7 @@ fun ToolsScreen(
     val crashUnreadCount by CrashReportManager.unreadCount.collectAsState()
     val oomUnreadCount by OOMReportManager.unreadCount.collectAsState()
     val tailscaleState by tailscaleViewModel.uiState.collectAsState()
+    val usbIPState by usbIPViewModel.uiState.collectAsState()
     val remoteServer by RemoteControlManager.remoteServer.collectAsState()
 
     LaunchedEffect(remoteServer?.id) {
@@ -109,8 +113,10 @@ fun ToolsScreen(
         // without tailscale leaves no active stream to error out, so the
         // subscription would stay stale without an explicit cancel.
         tailscaleViewModel.cancel()
+        usbIPViewModel.cancel()
         if (remoteServer != null || serviceStatus == Status.Started) {
             tailscaleViewModel.subscribe()
+            usbIPViewModel.subscribe()
         }
     }
 
@@ -120,8 +126,10 @@ fun ToolsScreen(
         }
         if (serviceStatus == Status.Started) {
             tailscaleViewModel.subscribe()
+            usbIPViewModel.subscribe()
         } else {
             tailscaleViewModel.cancel()
+            usbIPViewModel.cancel()
         }
     }
 
@@ -246,6 +254,59 @@ fun ToolsScreen(
             }
         }
 
+        if (usbIPState.servers.isNotEmpty()) {
+            Text(
+                text = stringResource(R.string.title_services),
+                style = MaterialTheme.typography.labelLarge,
+                color = MaterialTheme.colorScheme.primary,
+                modifier = Modifier.padding(horizontal = 32.dp, vertical = 8.dp),
+            )
+
+            Card(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = 16.dp),
+                colors = CardDefaults.cardColors(
+                    containerColor = MaterialTheme.colorScheme.surfaceContainer,
+                ),
+            ) {
+                val servers = usbIPState.servers
+                servers.forEachIndexed { index, server ->
+                    val shape = when {
+                        servers.size == 1 -> RoundedCornerShape(12.dp)
+                        index == 0 -> RoundedCornerShape(topStart = 12.dp, topEnd = 12.dp)
+                        index == servers.size - 1 -> RoundedCornerShape(bottomStart = 12.dp, bottomEnd = 12.dp)
+                        else -> RoundedCornerShape(0.dp)
+                    }
+                    ListItem(
+                        headlineContent = {
+                            Text(
+                                if (servers.size == 1) {
+                                    stringResource(R.string.title_usbip)
+                                } else {
+                                    stringResource(R.string.usbip_with_tag, server.serverTag)
+                                },
+                                style = MaterialTheme.typography.bodyLarge,
+                            )
+                        },
+                        leadingContent = {
+                            Icon(
+                                imageVector = Icons.Default.Usb,
+                                contentDescription = null,
+                                tint = MaterialTheme.colorScheme.primary,
+                            )
+                        },
+                        modifier = Modifier
+                            .clip(shape)
+                            .clickable {
+                                navController.navigate("tools/usbip/${Uri.encode(server.serverTag)}")
+                            },
+                        colors = ListItemDefaults.colors(containerColor = Color.Transparent),
+                    )
+                }
+            }
+        }
+
         Text(
             text = stringResource(R.string.title_network),
             style = MaterialTheme.typography.labelLarge,

app/src/main/java/io/nekohasekai/sfa/compose/screen/usbip/USBIPDeviceDetailScreen.kt

@@ -0,0 +1,146 @@
+package io.nekohasekai.sfa.compose.screen.usbip
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.unit.dp
+import androidx.navigation.NavController
+import io.nekohasekai.sfa.R
+import io.nekohasekai.sfa.compose.topbar.OverrideTopBar
+import io.nekohasekai.sfa.usbip.bcdToVersion
+import io.nekohasekai.sfa.usbip.formatVidPid
+import io.nekohasekai.sfa.usbip.usbBackendLabel
+import io.nekohasekai.sfa.usbip.usbClassTriplet
+import io.nekohasekai.sfa.usbip.usbSpeedLabel
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun USBIPDeviceDetailScreen(
+    navController: NavController,
+    viewModel: USBIPStatusViewModel,
+    serverTag: String,
+    deviceKey: String,
+) {
+    val state by viewModel.uiState.collectAsState()
+    val device = state.servers.firstOrNull { it.serverTag == serverTag }?.devices?.firstOrNull { it.key == deviceKey }
+
+    OverrideTopBar {
+        TopAppBar(
+            title = {
+                Text(device?.product?.ifEmpty { device.busId } ?: stringResource(R.string.title_usbip))
+            },
+            navigationIcon = {
+                IconButton(onClick = { navController.navigateUp() }) {
+                    Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = stringResource(R.string.content_description_back))
+                }
+            },
+        )
+    }
+
+    if (device == null) {
+        LaunchedEffect(Unit) { navController.navigateUp() }
+        return
+    }
+
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .background(MaterialTheme.colorScheme.surface)
+            .verticalScroll(rememberScrollState())
+            .padding(vertical = 8.dp),
+    ) {
+        DetailSection(stringResource(R.string.usbip_identity)) {
+            if (device.product.isNotEmpty()) DataLine(stringResource(R.string.usbip_product), device.product)
+            DataLine("VID:PID", formatVidPid(device.vendorId, device.productId), mono = true)
+            if (device.serial.isNotEmpty()) DataLine(stringResource(R.string.usbip_serial), device.serial, mono = true)
+            if (device.bcdDevice > 0) DataLine(stringResource(R.string.usbip_version), bcdToVersion(device.bcdDevice), mono = true)
+        }
+
+        DetailSection(stringResource(R.string.usbip_connection)) {
+            if (device.busId.isNotEmpty()) DataLine(stringResource(R.string.usbip_bus_id), device.busId, mono = true)
+            usbBackendLabel(device.backend)?.let { DataLine(stringResource(R.string.usbip_backend), it, mono = true) }
+            usbSpeedLabel(device.speed)?.let { DataLine(stringResource(R.string.usbip_speed), it) }
+            if (device.busNum > 0 || device.devNum > 0) {
+                DataLine(stringResource(R.string.usbip_bus_device), "${device.busNum} · ${device.devNum}", mono = true)
+            }
+        }
+
+        DetailSection(stringResource(R.string.usbip_class_interfaces)) {
+            DataLine(
+                stringResource(R.string.usbip_device_class),
+                usbClassTriplet(device.deviceClass, device.deviceSubClass, device.deviceProtocol),
+            )
+            DataLine(
+                stringResource(R.string.usbip_configuration),
+                "${device.configurationValue} / ${device.numConfigurations}",
+            )
+            device.interfaces.forEachIndexed { index, iface ->
+                DataLine(
+                    stringResource(R.string.usbip_interface, index),
+                    usbClassTriplet(iface.interfaceClass, iface.interfaceSubClass, iface.interfaceProtocol),
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun DetailSection(title: String, content: @Composable () -> Unit) {
+    Text(
+        text = title,
+        style = MaterialTheme.typography.titleSmall,
+        color = MaterialTheme.colorScheme.primary,
+        modifier = Modifier.padding(horizontal = 32.dp, vertical = 8.dp),
+    )
+    Card(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = 16.dp),
+        colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surfaceContainer),
+    ) {
+        Column(
+            modifier = Modifier.padding(16.dp),
+            verticalArrangement = Arrangement.spacedBy(12.dp),
+        ) {
+            content()
+        }
+    }
+}
+
+@Composable
+private fun DataLine(label: String, value: String, mono: Boolean = false) {
+    Row(
+        modifier = Modifier.fillMaxWidth(),
+        horizontalArrangement = Arrangement.SpaceBetween,
+    ) {
+        Text(label, style = MaterialTheme.typography.bodyMedium, color = MaterialTheme.colorScheme.onSurfaceVariant)
+        Text(
+            value,
+            style = MaterialTheme.typography.bodyMedium,
+            fontFamily = if (mono) FontFamily.Monospace else null,
+        )
+    }
+}

app/src/main/java/io/nekohasekai/sfa/compose/screen/usbip/USBIPServerScreen.kt

@@ -0,0 +1,354 @@
+package io.nekohasekai.sfa.compose.screen.usbip
+
+import android.content.Context
+import android.hardware.usb.UsbManager
+import android.net.Uri
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.IntrinsicSize
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.Add
+import androidx.compose.material.icons.filled.Check
+import androidx.compose.material.icons.filled.UsbOff
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.DropdownMenu
+import androidx.compose.material3.DropdownMenuItem
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import androidx.navigation.NavController
+import io.nekohasekai.libbox.Libbox
+import io.nekohasekai.sfa.R
+import io.nekohasekai.sfa.compose.topbar.OverrideTopBar
+import io.nekohasekai.sfa.usbip.ProvidedDevice
+import io.nekohasekai.sfa.usbip.ProvidedDeviceState
+import io.nekohasekai.sfa.usbip.USBIPManager
+import io.nekohasekai.sfa.usbip.formatVidPid
+
+private enum class Tone { GOOD, MEDIUM, BAD, NEUTRAL }
+
+private data class UsbDeviceRow(
+    val key: String,
+    val name: String,
+    val vidPid: String?,
+    val busId: String?,
+    val error: String?,
+    val backendState: Int?,
+    val providedState: ProvidedDeviceState?,
+    val deviceData: UsbSharedDeviceData?,
+    val providedDeviceId: String?,
+)
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun USBIPServerScreen(
+    navController: NavController,
+    viewModel: USBIPStatusViewModel,
+    serverTag: String,
+) {
+    val state by viewModel.uiState.collectAsState()
+    val providerState by USBIPManager.state.collectAsState()
+    val server = state.servers.firstOrNull { it.serverTag == serverTag }
+    val provided = providerState.devices.filter { it.serverTag == serverTag }
+    val endError = providerState.endErrors[serverTag]
+    val attach = rememberUsbAttacher(serverTag)
+
+    OverrideTopBar {
+        TopAppBar(
+            title = {
+                Text(
+                    if (state.servers.size <= 1) {
+                        stringResource(R.string.title_usbip)
+                    } else {
+                        stringResource(R.string.usbip_with_tag, serverTag)
+                    },
+                )
+            },
+            navigationIcon = {
+                IconButton(onClick = { navController.navigateUp() }) {
+                    Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = stringResource(R.string.content_description_back))
+                }
+            },
+            actions = {
+                if (server != null) {
+                    AddDeviceMenu(provided = provided, onPick = attach)
+                }
+            },
+        )
+    }
+
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .background(MaterialTheme.colorScheme.surface)
+            .verticalScroll(rememberScrollState())
+            .padding(vertical = 8.dp),
+    ) {
+        if (server == null) {
+            Text(
+                text = stringResource(R.string.usbip_no_server),
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(horizontal = 32.dp, vertical = 24.dp),
+            )
+            return@Column
+        }
+
+        if (endError != null) {
+            Text(
+                text = endError,
+                style = MaterialTheme.typography.bodySmall,
+                color = MaterialTheme.colorScheme.error,
+                modifier = Modifier.padding(horizontal = 32.dp, vertical = 8.dp),
+            )
+        }
+
+        val rows = mergeRows(server, provided)
+        if (rows.isEmpty()) {
+            Text(
+                text = stringResource(R.string.usbip_no_devices),
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.padding(horizontal = 32.dp, vertical = 24.dp),
+            )
+        } else {
+            Card(
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .padding(horizontal = 16.dp),
+                colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.surfaceContainer),
+            ) {
+                Column {
+                    for (row in rows) {
+                        DeviceItem(
+                            row = row,
+                            onOpen = {
+                                if (row.deviceData != null) {
+                                    navController.navigate("tools/usbip/${Uri.encode(serverTag)}/device/${Uri.encode(row.key)}")
+                                }
+                            },
+                            onDetach = { id -> USBIPManager.detach(id) },
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun AddDeviceMenu(provided: List<ProvidedDevice>, onPick: (android.hardware.usb.UsbDevice) -> Unit) {
+    val context = LocalContext.current
+    var expanded by remember { mutableStateOf(false) }
+    Box {
+        IconButton(onClick = { expanded = true }) {
+            Icon(Icons.Default.Add, contentDescription = stringResource(R.string.usbip_connect_device))
+        }
+        DropdownMenu(expanded = expanded, onDismissRequest = { expanded = false }) {
+            val usbManager = context.getSystemService(Context.USB_SERVICE) as UsbManager
+            val devices = usbManager.deviceList.values.toList()
+            val attachedNames = provided.mapNotNull { it.usbDeviceName }.toSet()
+            if (devices.isEmpty()) {
+                DropdownMenuItem(
+                    enabled = false,
+                    text = { Text(stringResource(R.string.usbip_no_usb_devices)) },
+                    onClick = {},
+                )
+            }
+            for (device in devices) {
+                val attached = device.deviceName in attachedNames
+                DropdownMenuItem(
+                    enabled = !attached,
+                    leadingIcon = {
+                        if (attached) {
+                            Icon(Icons.Default.Check, contentDescription = null, modifier = Modifier.size(18.dp))
+                        }
+                    },
+                    text = {
+                        Column {
+                            Text(device.productName ?: formatVidPid(device.vendorId, device.productId))
+                            Text(
+                                formatVidPid(device.vendorId, device.productId),
+                                style = MaterialTheme.typography.bodySmall,
+                                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            )
+                        }
+                    },
+                    onClick = {
+                        expanded = false
+                        onPick(device)
+                    },
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun DeviceItem(row: UsbDeviceRow, onOpen: () -> Unit, onDetach: (String) -> Unit) {
+    val (label, tone) = stateInfo(row)
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .height(IntrinsicSize.Min),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Row(
+            modifier = Modifier
+                .weight(1f)
+                .fillMaxHeight()
+                .clickable(enabled = row.deviceData != null, onClick = onOpen)
+                .padding(horizontal = 16.dp, vertical = 12.dp),
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Box(
+                modifier = Modifier
+                    .size(8.dp)
+                    .clip(CircleShape)
+                    .background(toneColor(tone)),
+            )
+            Column(
+                modifier = Modifier
+                    .weight(1f)
+                    .padding(start = 12.dp),
+            ) {
+                Row(verticalAlignment = Alignment.CenterVertically) {
+                    Text(
+                        "${row.name}:",
+                        style = MaterialTheme.typography.bodyLarge,
+                        maxLines = 1,
+                        overflow = TextOverflow.Ellipsis,
+                        modifier = Modifier.weight(1f, fill = false),
+                    )
+                    Text(
+                        label,
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        maxLines = 1,
+                        modifier = Modifier.padding(start = 4.dp),
+                    )
+                }
+                if (row.error != null) {
+                    Text(row.error, style = MaterialTheme.typography.bodySmall, color = MaterialTheme.colorScheme.error)
+                }
+            }
+        }
+        if (row.providedDeviceId != null) {
+            Box(
+                modifier = Modifier
+                    .fillMaxHeight()
+                    .width(52.dp)
+                    .clickable { onDetach(row.providedDeviceId) },
+                contentAlignment = Alignment.Center,
+            ) {
+                Icon(
+                    Icons.Default.UsbOff,
+                    contentDescription = stringResource(R.string.usbip_detach),
+                    tint = MaterialTheme.colorScheme.error,
+                )
+            }
+        }
+    }
+}
+
+@Composable
+private fun stateInfo(row: UsbDeviceRow): Pair<String, Tone> {
+    row.backendState?.let { backend ->
+        return when (backend) {
+            Libbox.USBDeviceStateIdle -> stringResource(R.string.usbip_state_idle) to Tone.GOOD
+            Libbox.USBDeviceStateAttached -> stringResource(R.string.usbip_state_attached) to Tone.MEDIUM
+            Libbox.USBDeviceStateUnavailable -> stringResource(R.string.usbip_state_unavailable) to Tone.BAD
+            else -> "" to Tone.NEUTRAL
+        }
+    }
+    return when (row.providedState) {
+        ProvidedDeviceState.ATTACHING -> stringResource(R.string.usbip_state_attaching) to Tone.MEDIUM
+        ProvidedDeviceState.READY -> stringResource(R.string.usbip_state_ready) to Tone.GOOD
+        ProvidedDeviceState.ERROR -> stringResource(R.string.usbip_state_error) to Tone.BAD
+        null -> "" to Tone.NEUTRAL
+    }
+}
+
+@Composable
+private fun toneColor(tone: Tone): Color = when (tone) {
+    Tone.GOOD -> Color(0xFF4CAF50)
+    Tone.MEDIUM -> MaterialTheme.colorScheme.primary
+    Tone.BAD -> MaterialTheme.colorScheme.error
+    Tone.NEUTRAL -> Color.Gray
+}
+
+private fun mergeRows(server: UsbipServerData, provided: List<ProvidedDevice>): List<UsbDeviceRow> {
+    val providedByBusId =
+        provided.filter { it.state == ProvidedDeviceState.READY && it.busId != null }.associateBy { it.busId!! }
+    val matched = HashSet<String>()
+    val rows = mutableListOf<UsbDeviceRow>()
+
+    for (device in server.devices) {
+        val providedDevice = providedByBusId[device.busId]
+        if (providedDevice != null) matched.add(providedDevice.deviceId)
+        rows.add(
+            UsbDeviceRow(
+                key = device.key,
+                name = device.product.ifEmpty { formatVidPid(device.vendorId, device.productId) },
+                vidPid = formatVidPid(device.vendorId, device.productId),
+                busId = device.busId,
+                error = null,
+                backendState = device.state,
+                providedState = null,
+                deviceData = device,
+                providedDeviceId = providedDevice?.deviceId,
+            ),
+        )
+    }
+
+    for (device in provided) {
+        if (matched.contains(device.deviceId)) continue
+        rows.add(
+            UsbDeviceRow(
+                key = "provided-${device.deviceId}",
+                name = device.label,
+                vidPid = formatVidPid(device.vendorId, device.productId),
+                busId = if (device.state == ProvidedDeviceState.READY) device.busId else null,
+                error = if (device.state == ProvidedDeviceState.ERROR) device.error else null,
+                backendState = null,
+                providedState = device.state,
+                deviceData = null,
+                providedDeviceId = device.deviceId,
+            ),
+        )
+    }
+
+    return rows
+}

app/src/main/java/io/nekohasekai/sfa/compose/screen/usbip/USBIPStatusViewModel.kt

@@ -0,0 +1,164 @@
+package io.nekohasekai.sfa.compose.screen.usbip
+
+import androidx.lifecycle.viewModelScope
+import io.nekohasekai.libbox.USBIPServerStatus
+import io.nekohasekai.libbox.USBIPServerStatusHandler
+import io.nekohasekai.libbox.USBIPServerStatusSubscription
+import io.nekohasekai.libbox.USBIPServerStatusUpdate
+import io.nekohasekai.libbox.USBSharedDevice
+import io.nekohasekai.sfa.compose.base.BaseViewModel
+import io.nekohasekai.sfa.utils.CommandTarget
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+
+data class UsbSharedInterfaceData(
+    val interfaceClass: Int,
+    val interfaceSubClass: Int,
+    val interfaceProtocol: Int,
+)
+
+data class UsbSharedDeviceData(
+    val busId: String,
+    val stableId: String,
+    val backend: Int,
+    val state: Int,
+    val deviceId: String,
+    val busNum: Int,
+    val devNum: Int,
+    val speed: Int,
+    val vendorId: Int,
+    val productId: Int,
+    val bcdDevice: Int,
+    val deviceClass: Int,
+    val deviceSubClass: Int,
+    val deviceProtocol: Int,
+    val configurationValue: Int,
+    val numConfigurations: Int,
+    val serial: String,
+    val product: String,
+    val interfaces: List<UsbSharedInterfaceData>,
+) {
+    val key: String get() = stableId.ifEmpty { busId }
+}
+
+data class UsbipServerData(
+    val serverTag: String,
+    val devices: List<UsbSharedDeviceData>,
+)
+
+data class USBIPStatusState(
+    val servers: List<UsbipServerData> = emptyList(),
+    val isSubscribed: Boolean = false,
+)
+
+class USBIPStatusViewModel : BaseViewModel<USBIPStatusState, Nothing>() {
+    private var subscription: USBIPServerStatusSubscription? = null
+
+    override fun createInitialState() = USBIPStatusState()
+
+    fun subscribe() {
+        if (currentState.isSubscribed) return
+        updateState { copy(isSubscribed = true) }
+
+        viewModelScope.launch(Dispatchers.IO) {
+            try {
+                subscription =
+                    CommandTarget.standaloneClient().subscribeUSBIPServerStatus(
+                        object : USBIPServerStatusHandler {
+                            override fun onStatusUpdate(status: USBIPServerStatusUpdate) {
+                                val servers = convertUpdate(status)
+                                viewModelScope.launch {
+                                    if (!currentState.isSubscribed) return@launch
+                                    updateState { copy(servers = servers) }
+                                }
+                            }
+
+                            override fun onError(message: String) {
+                                viewModelScope.launch {
+                                    if (!currentState.isSubscribed) return@launch
+                                    updateState { copy(servers = emptyList(), isSubscribed = false) }
+                                    subscription = null
+                                    sendErrorMessage(message)
+                                }
+                            }
+                        },
+                    )
+            } catch (_: Exception) {
+                viewModelScope.launch {
+                    updateState { copy(servers = emptyList(), isSubscribed = false) }
+                    subscription = null
+                }
+            }
+        }
+    }
+
+    fun cancel() {
+        try {
+            subscription?.close()
+        } catch (_: Exception) {
+        }
+        subscription = null
+        updateState { copy(servers = emptyList(), isSubscribed = false) }
+    }
+
+    fun server(tag: String): UsbipServerData? = currentState.servers.firstOrNull { it.serverTag == tag }
+
+    override fun onCleared() {
+        cancel()
+        super.onCleared()
+    }
+
+    private fun convertUpdate(status: USBIPServerStatusUpdate): List<UsbipServerData> {
+        val servers = mutableListOf<UsbipServerData>()
+        val iterator = status.servers()
+        while (iterator.hasNext()) {
+            servers.add(convertServer(iterator.next()))
+        }
+        return servers
+    }
+
+    private fun convertServer(server: USBIPServerStatus): UsbipServerData {
+        val devices = mutableListOf<UsbSharedDeviceData>()
+        val iterator = server.devices()
+        while (iterator.hasNext()) {
+            devices.add(convertDevice(iterator.next()))
+        }
+        return UsbipServerData(serverTag = server.serverTag, devices = devices)
+    }
+
+    private fun convertDevice(device: USBSharedDevice): UsbSharedDeviceData {
+        val interfaces = mutableListOf<UsbSharedInterfaceData>()
+        val iterator = device.interfaces()
+        while (iterator.hasNext()) {
+            val iface = iterator.next()
+            interfaces.add(
+                UsbSharedInterfaceData(
+                    interfaceClass = iface.interfaceClass,
+                    interfaceSubClass = iface.interfaceSubClass,
+                    interfaceProtocol = iface.interfaceProtocol,
+                ),
+            )
+        }
+        return UsbSharedDeviceData(
+            busId = device.busID,
+            stableId = device.stableID,
+            backend = device.backend,
+            state = device.state,
+            deviceId = device.deviceID,
+            busNum = device.busNum,
+            devNum = device.devNum,
+            speed = device.speed,
+            vendorId = device.vendorID,
+            productId = device.productID,
+            bcdDevice = device.getBCDDevice(),
+            deviceClass = device.deviceClass,
+            deviceSubClass = device.deviceSubClass,
+            deviceProtocol = device.deviceProtocol,
+            configurationValue = device.configurationValue,
+            numConfigurations = device.numConfigurations,
+            serial = device.serial,
+            product = device.product,
+            interfaces = interfaces,
+        )
+    }
+}

app/src/main/java/io/nekohasekai/sfa/compose/screen/usbip/UsbAttach.kt

@@ -0,0 +1,63 @@
+package io.nekohasekai.sfa.compose.screen.usbip
+
+import android.app.PendingIntent
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.hardware.usb.UsbDevice
+import android.hardware.usb.UsbManager
+import android.os.Build
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.remember
+import androidx.compose.ui.platform.LocalContext
+import androidx.core.content.ContextCompat
+import androidx.core.content.IntentCompat
+import io.nekohasekai.sfa.usbip.USBIPManager
+
+private const val ACTION_USB_PERMISSION = "io.nekohasekai.sfa.action.USB_PERMISSION"
+
+@Composable
+fun rememberUsbAttacher(serverTag: String): (UsbDevice) -> Unit {
+    val context = LocalContext.current
+    val usbManager = remember { context.getSystemService(Context.USB_SERVICE) as UsbManager }
+
+    DisposableEffect(serverTag) {
+        val receiver =
+            object : BroadcastReceiver() {
+                override fun onReceive(received: Context, intent: Intent) {
+                    if (intent.action != ACTION_USB_PERMISSION) return
+                    val device = IntentCompat.getParcelableExtra(intent, UsbManager.EXTRA_DEVICE, UsbDevice::class.java) ?: return
+                    if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
+                        USBIPManager.attach(received, serverTag, device)
+                    }
+                }
+            }
+        ContextCompat.registerReceiver(
+            context,
+            receiver,
+            IntentFilter(ACTION_USB_PERMISSION),
+            ContextCompat.RECEIVER_NOT_EXPORTED,
+        )
+        onDispose { context.unregisterReceiver(receiver) }
+    }
+
+    return remember(serverTag) {
+        { device: UsbDevice ->
+            if (usbManager.hasPermission(device)) {
+                USBIPManager.attach(context, serverTag, device)
+            } else {
+                val flags = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) PendingIntent.FLAG_MUTABLE else 0
+                val pendingIntent =
+                    PendingIntent.getBroadcast(
+                        context,
+                        0,
+                        Intent(ACTION_USB_PERMISSION).setPackage(context.packageName),
+                        flags,
+                    )
+                usbManager.requestPermission(device, pendingIntent)
+            }
+        }
+    }
+}

app/src/main/java/io/nekohasekai/sfa/database/RemoteServer.kt

@@ -22,20 +22,35 @@ class RemoteServer(
     var secret: String = "",
 ) : Parcelable {
     val displayName: String
-        get() = name.ifEmpty { url }
+        get() = name.ifEmpty { hostPort(url) }
 
     companion object {
-        fun validateURL(urlString: String): String? {
-            var trimmed = urlString.trim()
-            if (trimmed.isEmpty()) {
-                return null
+        private val schemePrefix = Regex("^https?://", RegexOption.IGNORE_CASE)
+        private val httpPrefix = Regex("^http://", RegexOption.IGNORE_CASE)
+
+        // The stored form: scheme-less for http (default), keeping an explicit https.
+        fun normalizeURL(urlString: String): String = urlString.trim().trimEnd('/').replaceFirst(httpPrefix, "")
+
+        // The form passed to libbox: a scheme is required, defaulting to http.
+        fun connectURL(urlString: String): String {
+            val value = urlString.trim().trimEnd('/')
+            if (value.isEmpty()) {
+                return ""
             }
-            if (!trimmed.contains("://")) {
-                trimmed = "http://$trimmed"
+            if (value.contains(schemePrefix)) {
+                return value
+            }
+            return "http://$value"
+        }
+
+        fun validateURL(urlString: String): String? {
+            val connectURL = connectURL(urlString)
+            if (connectURL.isEmpty()) {
+                return null
             }
             val uri =
                 try {
-                    URI(trimmed)
+                    URI(connectURL)
                 } catch (_: Exception) {
                     return null
                 }
@@ -46,7 +61,18 @@ class RemoteServer(
             if (uri.host.isNullOrEmpty()) {
                 return null
             }
-            return trimmed
+            return normalizeURL(urlString)
+        }
+
+        private fun hostPort(urlString: String): String {
+            val uri =
+                try {
+                    URI(connectURL(urlString))
+                } catch (_: Exception) {
+                    return urlString
+                }
+            val host = uri.host ?: return urlString
+            return if (uri.port != -1) "$host:${uri.port}" else host
         }
     }
 

app/src/main/java/io/nekohasekai/sfa/usbip/ProvidedDevice.kt

@@ -0,0 +1,20 @@
+package io.nekohasekai.sfa.usbip
+
+enum class ProvidedDeviceState { ATTACHING, READY, ERROR }
+
+data class ProvidedDevice(
+    val deviceId: String,
+    val serverTag: String,
+    val label: String,
+    val vendorId: Int,
+    val productId: Int,
+    val state: ProvidedDeviceState,
+    val busId: String? = null,
+    val error: String? = null,
+    val usbDeviceName: String? = null,
+)
+
+data class USBIPProviderState(
+    val devices: List<ProvidedDevice> = emptyList(),
+    val endErrors: Map<String, String> = emptyMap(),
+)

app/src/main/java/io/nekohasekai/sfa/usbip/USBIPManager.kt

@@ -0,0 +1,255 @@
+package io.nekohasekai.sfa.usbip
+
+import android.content.Context
+import android.content.Intent
+import android.hardware.usb.UsbDevice
+import android.hardware.usb.UsbManager
+import androidx.core.content.ContextCompat
+import io.nekohasekai.libbox.USBProviderHandler
+import io.nekohasekai.libbox.USBProviderSession
+import io.nekohasekai.libbox.USBURBRequest
+import io.nekohasekai.libbox.USBURBResponse
+import io.nekohasekai.sfa.bg.USBIPService
+import io.nekohasekai.sfa.utils.CommandTarget
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import java.util.concurrent.atomic.AtomicInteger
+
+object USBIPManager {
+    private val access = Any()
+    private val sessions = HashMap<String, ServerSession>()
+    private val endErrors = HashMap<String, String>()
+    private val counter = AtomicInteger(0)
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+
+    @Volatile
+    private var serviceStarted = false
+
+    private val _state = MutableStateFlow(USBIPProviderState())
+    val state: StateFlow<USBIPProviderState> = _state.asStateFlow()
+
+    private class ServerSession(val serverTag: String, val session: USBProviderSession) {
+        val bridges = HashMap<String, UsbDeviceBridge>()
+        val devices = HashMap<String, ProvidedDevice>()
+
+        @Volatile
+        var closed = false
+    }
+
+    fun attach(context: Context, serverTag: String, device: UsbDevice) {
+        val appContext = context.applicationContext
+        scope.launch { attachInternal(appContext, serverTag, device) }
+    }
+
+    fun detach(deviceId: String) {
+        scope.launch { detachInternal(deviceId) }
+    }
+
+    fun detachByDevice(device: UsbDevice) {
+        val deviceId =
+            synchronized(access) {
+                sessions.values.flatMap { it.devices.values }.firstOrNull { it.usbDeviceName == device.deviceName }?.deviceId
+            } ?: return
+        detach(deviceId)
+    }
+
+    fun shutdown() {
+        scope.launch {
+            val current = synchronized(access) { sessions.values.toList().also { sessions.clear() } }
+            for (session in current) {
+                session.closed = true
+                for (bridge in session.bridges.values) bridge.close()
+                runCatching { session.session.close() }
+            }
+            synchronized(access) { endErrors.clear() }
+            publish()
+        }
+    }
+
+    fun onServiceDestroyed() {
+        serviceStarted = false
+    }
+
+    private fun attachInternal(context: Context, serverTag: String, device: UsbDevice) {
+        val deviceId = "dev-${counter.incrementAndGet()}"
+        try {
+            val session = ensureSession(serverTag)
+            synchronized(access) { session.devices[deviceId] = providedDevice(deviceId, serverTag, device) }
+            publish()
+            startServiceIfNeeded(context)
+            val manager = context.getSystemService(Context.USB_SERVICE) as UsbManager
+            val (bridge, descriptor) =
+                UsbDeviceBridge.open(deviceId, serverTag, manager, device) { response -> sendResponse(session, response) }
+            val kept =
+                synchronized(access) {
+                    if (session.devices.containsKey(deviceId)) {
+                        session.bridges[deviceId] = bridge
+                        true
+                    } else {
+                        false
+                    }
+                }
+            if (!kept) {
+                bridge.close()
+                return
+            }
+            session.session.attachDevice(descriptor)
+        } catch (e: Throwable) {
+            markError(serverTag, deviceId, e.message ?: "attach failed")
+        }
+    }
+
+    private fun detachInternal(deviceId: String) {
+        val session = synchronized(access) { sessions.values.firstOrNull { it.devices.containsKey(deviceId) } } ?: return
+        val bridge = synchronized(access) {
+            session.devices.remove(deviceId)
+            session.bridges.remove(deviceId)
+        }
+        runCatching { session.session.detachDevice(deviceId) }
+        bridge?.close()
+        publish()
+        closeSessionIfEmpty(session)
+    }
+
+    // The libbox session is opened outside the lock: provideUSBDevices dials the daemon
+    // and would otherwise block URB dispatch for already-open sessions.
+    private fun ensureSession(serverTag: String): ServerSession {
+        synchronized(access) { sessions[serverTag]?.let { return it } }
+        val libboxSession = CommandTarget.standaloneClient().provideUSBDevices(handler(serverTag))
+        synchronized(access) {
+            sessions[serverTag]?.let {
+                runCatching { libboxSession.close() }
+                return it
+            }
+            val session = ServerSession(serverTag, libboxSession)
+            sessions[serverTag] = session
+            return session
+        }
+    }
+
+    private fun providedDevice(deviceId: String, serverTag: String, device: UsbDevice) = ProvidedDevice(
+        deviceId = deviceId,
+        serverTag = serverTag,
+        label = device.productName ?: formatVidPid(device.vendorId, device.productId),
+        vendorId = device.vendorId,
+        productId = device.productId,
+        state = ProvidedDeviceState.ATTACHING,
+        usbDeviceName = device.deviceName,
+    )
+
+    private fun handler(serverTag: String): USBProviderHandler = object : USBProviderHandler {
+        override fun onReady(deviceID: String, busID: String) = onDeviceReady(serverTag, deviceID, busID)
+
+        override fun onURBRequest(request: USBURBRequest) = dispatchUrb(serverTag, request)
+
+        override fun onAbort(deviceID: String, endpoint: Int) {}
+
+        override fun onError(deviceID: String, message: String) = onProviderError(serverTag, deviceID, message)
+    }
+
+    private fun sendResponse(session: ServerSession, response: USBURBResponse) {
+        if (session.closed) return
+        runCatching { session.session.sendURBResponse(response) }
+    }
+
+    private fun dispatchUrb(serverTag: String, request: USBURBRequest) {
+        val bridge = synchronized(access) { sessions[serverTag]?.bridges?.get(request.deviceID) } ?: return
+        bridge.submit(request)
+    }
+
+    private fun onDeviceReady(serverTag: String, deviceId: String, busId: String) {
+        synchronized(access) {
+            val session = sessions[serverTag] ?: return@synchronized
+            val device = session.devices[deviceId] ?: return@synchronized
+            session.devices[deviceId] = device.copy(state = ProvidedDeviceState.READY, busId = busId, error = null)
+        }
+        publish()
+    }
+
+    private fun onProviderError(serverTag: String, deviceId: String, message: String) {
+        val session = synchronized(access) { sessions[serverTag] } ?: return
+        if (session.closed) return
+        if (deviceId.isNotEmpty()) {
+            markError(serverTag, deviceId, message)
+            val bridge = synchronized(access) { session.bridges.remove(deviceId) }
+            bridge?.close()
+            return
+        }
+        session.closed = true
+        val bridges =
+            synchronized(access) {
+                endErrors[serverTag] = message
+                session.devices.keys.forEach { id ->
+                    val device = session.devices.getValue(id)
+                    if (device.state != ProvidedDeviceState.ERROR) {
+                        session.devices[id] = device.copy(state = ProvidedDeviceState.ERROR, error = message)
+                    }
+                }
+                session.bridges.values.toList().also { session.bridges.clear() }
+            }
+        for (bridge in bridges) bridge.close()
+        runCatching { session.session.close() }
+        synchronized(access) { sessions.remove(serverTag) }
+        publish()
+        stopServiceIfIdle()
+    }
+
+    private fun markError(serverTag: String, deviceId: String, message: String) {
+        synchronized(access) {
+            val session = sessions[serverTag]
+            val device = session?.devices?.get(deviceId)
+            if (session != null && device != null) {
+                session.devices[deviceId] = device.copy(state = ProvidedDeviceState.ERROR, error = message)
+            } else {
+                endErrors[serverTag] = message
+            }
+        }
+        publish()
+    }
+
+    private fun closeSessionIfEmpty(session: ServerSession) {
+        val empty =
+            synchronized(access) {
+                if (session.devices.isEmpty()) {
+                    session.closed = true
+                    sessions.remove(session.serverTag)
+                    endErrors.remove(session.serverTag)
+                    true
+                } else {
+                    false
+                }
+            }
+        if (empty) {
+            runCatching { session.session.close() }
+            publish()
+            stopServiceIfIdle()
+        }
+    }
+
+    private fun publish() {
+        val snapshot =
+            synchronized(access) {
+                USBIPProviderState(
+                    devices = sessions.values.flatMap { it.devices.values }.sortedBy { it.deviceId },
+                    endErrors = HashMap(endErrors),
+                )
+            }
+        _state.value = snapshot
+    }
+
+    private fun startServiceIfNeeded(context: Context) {
+        if (serviceStarted) return
+        serviceStarted = true
+        ContextCompat.startForegroundService(context, Intent(context, USBIPService::class.java))
+    }
+
+    private fun stopServiceIfIdle() {
+        val idle = synchronized(access) { sessions.isEmpty() }
+        if (idle) serviceStarted = false
+    }
+}

app/src/main/java/io/nekohasekai/sfa/usbip/UsbDeviceBridge.kt

@@ -0,0 +1,278 @@
+package io.nekohasekai.sfa.usbip
+
+import android.hardware.usb.UsbConfiguration
+import android.hardware.usb.UsbDevice
+import android.hardware.usb.UsbDeviceConnection
+import android.hardware.usb.UsbEndpoint
+import android.hardware.usb.UsbInterface
+import android.hardware.usb.UsbManager
+import io.nekohasekai.libbox.Libbox
+import io.nekohasekai.libbox.USBDeviceDescriptor
+import io.nekohasekai.libbox.USBURBRequest
+import io.nekohasekai.libbox.USBURBResponse
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.ExecutorService
+import java.util.concurrent.Executors
+
+class UsbDeviceBridge private constructor(
+    val deviceId: String,
+    private val device: UsbDevice,
+    private val connection: UsbDeviceConnection,
+    private val send: (USBURBResponse) -> Unit,
+) {
+    private val claimedInterfaces = ArrayList<UsbInterface>()
+    private val endpoints = ConcurrentHashMap<Int, UsbEndpoint>()
+    private val executors = ConcurrentHashMap<Int, ExecutorService>()
+
+    @Volatile
+    private var closed = false
+
+    private fun start(serverTag: String): USBDeviceDescriptor {
+        val configuration = if (device.configurationCount > 0) device.getConfiguration(0) else null
+        if (configuration != null) {
+            claimConfiguration(configuration)
+        }
+        return buildDescriptor(serverTag, configuration)
+    }
+
+    private fun claimConfiguration(configuration: UsbConfiguration) {
+        releaseInterfaces()
+        endpoints.clear()
+        for (index in 0 until configuration.interfaceCount) {
+            val iface = configuration.getInterface(index)
+            if (connection.claimInterface(iface, true)) {
+                claimedInterfaces.add(iface)
+                indexEndpoints(iface)
+            }
+        }
+    }
+
+    private fun indexEndpoints(iface: UsbInterface) {
+        for (index in 0 until iface.endpointCount) {
+            val endpoint = iface.getEndpoint(index)
+            endpoints[endpoint.endpointNumber or endpoint.direction] = endpoint
+        }
+    }
+
+    private fun buildDescriptor(serverTag: String, configuration: UsbConfiguration?): USBDeviceDescriptor {
+        val raw = connection.rawDescriptors
+        val (busNum, devNum) = parseBusDevice(device.deviceName)
+        val descriptor = Libbox.newUSBDeviceDescriptor(serverTag, deviceId)
+        descriptor.setBusNum(busNum)
+        descriptor.setDevNum(devNum)
+        descriptor.setSpeed(inferSpeed(readWord(raw, 2)))
+        descriptor.setVendorID(device.vendorId)
+        descriptor.setProductID(device.productId)
+        descriptor.setBCDDevice(readWord(raw, 12))
+        descriptor.setDeviceClass(device.deviceClass)
+        descriptor.setDeviceSubClass(device.deviceSubclass)
+        descriptor.setDeviceProtocol(device.deviceProtocol)
+        descriptor.setConfigurationValue(configuration?.id ?: 0)
+        descriptor.setNumConfigurations(device.configurationCount)
+        descriptor.setSerial(serialNumber())
+        descriptor.setProduct(device.productName ?: "")
+        if (configuration != null) {
+            val seen = HashSet<Int>()
+            for (index in 0 until configuration.interfaceCount) {
+                val iface = configuration.getInterface(index)
+                if (seen.add(iface.id)) {
+                    descriptor.addInterface(iface.interfaceClass, iface.interfaceSubclass, iface.interfaceProtocol)
+                }
+            }
+        }
+        return descriptor
+    }
+
+    private fun serialNumber(): String = try {
+        device.serialNumber ?: ""
+    } catch (_: SecurityException) {
+        ""
+    }
+
+    fun submit(request: USBURBRequest) {
+        if (closed) return
+        val endpointNumber = request.endpoint and 0x0f
+        executors.getOrPut(endpointNumber) { Executors.newSingleThreadExecutor() }
+            .execute { execute(request, endpointNumber) }
+    }
+
+    private fun execute(request: USBURBRequest, endpointNumber: Int) {
+        if (closed) return
+        val response = Libbox.newUSBURBResponse(deviceId, request.seq)
+        try {
+            when {
+                endpointNumber == 0 -> executeControl(request, response)
+                request.numberOfPackets > 0 -> response.setStatus(URB_EPROTO)
+                else -> executeBulk(request, endpointNumber, response)
+            }
+        } catch (e: Throwable) {
+            response.setStatus(URB_EPROTO)
+        }
+        if (!closed) send(response)
+    }
+
+    private fun executeControl(request: USBURBRequest, response: USBURBResponse) {
+        val setup = UsbSetup(request.setup)
+        if (!setup.directionIn && setup.isStandard && handleManagedControl(setup)) {
+            response.setStatus(URB_OK)
+            response.setActualLength(0)
+            return
+        }
+        if (setup.directionIn) {
+            val buffer = ByteArray(request.transferBufferLength)
+            val transferred =
+                connection.controlTransfer(
+                    setup.requestType,
+                    setup.request,
+                    setup.value,
+                    setup.index,
+                    buffer,
+                    buffer.size,
+                    CONTROL_TIMEOUT_MS,
+                )
+            applyResult(response, transferred, buffer)
+        } else {
+            val out = request.outData
+            val transferred =
+                connection.controlTransfer(
+                    setup.requestType,
+                    setup.request,
+                    setup.value,
+                    setup.index,
+                    out,
+                    out.size,
+                    CONTROL_TIMEOUT_MS,
+                )
+            applyResult(response, transferred, null)
+        }
+    }
+
+    private fun handleManagedControl(setup: UsbSetup): Boolean {
+        when (setup.request) {
+            USB_REQUEST_SET_CONFIGURATION -> {
+                val configuration = findConfiguration(setup.value and 0xff) ?: return false
+                connection.setConfiguration(configuration)
+                claimConfiguration(configuration)
+                return true
+            }
+            USB_REQUEST_SET_INTERFACE -> {
+                val iface = findInterface(setup.index and 0xff, setup.value and 0xff) ?: return false
+                connection.setInterface(iface)
+                indexEndpoints(iface)
+                return true
+            }
+        }
+        return false
+    }
+
+    private fun executeBulk(request: USBURBRequest, endpointNumber: Int, response: USBURBResponse) {
+        val direction = if (request.directionIn) USB_DIR_IN else 0
+        val endpoint = endpoints[endpointNumber or direction]
+        if (endpoint == null) {
+            response.setStatus(URB_EPIPE)
+            return
+        }
+        if (request.directionIn) {
+            val buffer = ByteArray(request.transferBufferLength)
+            val transferred = connection.bulkTransfer(endpoint, buffer, buffer.size, TRANSFER_TIMEOUT_MS)
+            applyResult(response, transferred, buffer)
+        } else {
+            val out = request.outData
+            val transferred = connection.bulkTransfer(endpoint, out, out.size, TRANSFER_TIMEOUT_MS)
+            applyResult(response, transferred, null)
+        }
+    }
+
+    private fun applyResult(response: USBURBResponse, transferred: Int, inData: ByteArray?) {
+        if (transferred < 0) {
+            response.setStatus(URB_EPROTO)
+            return
+        }
+        response.setStatus(URB_OK)
+        response.setActualLength(transferred)
+        if (inData != null) {
+            response.setInData(if (transferred == inData.size) inData else inData.copyOf(transferred))
+        }
+    }
+
+    private fun findConfiguration(value: Int): UsbConfiguration? {
+        for (index in 0 until device.configurationCount) {
+            val configuration = device.getConfiguration(index)
+            if (configuration.id == value) return configuration
+        }
+        return null
+    }
+
+    private fun findInterface(interfaceNumber: Int, altSetting: Int): UsbInterface? {
+        for (index in 0 until device.interfaceCount) {
+            val iface = device.getInterface(index)
+            if (iface.id == interfaceNumber && iface.alternateSetting == altSetting) return iface
+        }
+        return null
+    }
+
+    private fun releaseInterfaces() {
+        for (iface in claimedInterfaces) {
+            try {
+                connection.releaseInterface(iface)
+            } catch (_: Throwable) {
+            }
+        }
+        claimedInterfaces.clear()
+    }
+
+    fun close() {
+        if (closed) return
+        closed = true
+        for (executor in executors.values) executor.shutdownNow()
+        executors.clear()
+        releaseInterfaces()
+        try {
+            connection.close()
+        } catch (_: Throwable) {
+        }
+    }
+
+    companion object {
+        fun open(
+            deviceId: String,
+            serverTag: String,
+            manager: UsbManager,
+            device: UsbDevice,
+            send: (USBURBResponse) -> Unit,
+        ): Pair<UsbDeviceBridge, USBDeviceDescriptor> {
+            val connection = manager.openDevice(device) ?: throw IllegalStateException("open device failed")
+            val bridge = UsbDeviceBridge(deviceId, device, connection, send)
+            try {
+                return bridge to bridge.start(serverTag)
+            } catch (e: Throwable) {
+                bridge.close()
+                throw e
+            }
+        }
+
+        // UsbDevice.getDeviceName() is the usbfs node "/dev/bus/usb/BBB/DDD".
+        private fun parseBusDevice(name: String): Pair<Int, Int> {
+            val parts = name.split("/")
+            val devNum = parts.getOrNull(parts.size - 1)?.toIntOrNull() ?: 0
+            val busNum = parts.getOrNull(parts.size - 2)?.toIntOrNull() ?: 0
+            return busNum to devNum
+        }
+
+        private fun readWord(raw: ByteArray?, offset: Int): Int {
+            if (raw == null || raw.size < offset + 2) return 0
+            return (raw[offset].toInt() and 0xff) or ((raw[offset + 1].toInt() and 0xff) shl 8)
+        }
+
+        private fun inferSpeed(bcdUSB: Int): Int = when {
+            (bcdUSB shr 8) and 0xff >= 3 -> 5
+            (bcdUSB shr 8) and 0xff >= 2 -> 3
+            else -> 2
+        }
+
+        private const val CONTROL_TIMEOUT_MS = 5000
+
+        // Block until the endpoint completes; detach closes the fd to unblock waiters.
+        private const val TRANSFER_TIMEOUT_MS = 0
+    }
+}

app/src/main/java/io/nekohasekai/sfa/usbip/UsbInfo.kt

@@ -0,0 +1,62 @@
+package io.nekohasekai.sfa.usbip
+
+private val USB_CLASS_NAMES =
+    mapOf(
+        0x01 to "Audio",
+        0x02 to "CDC Control",
+        0x03 to "HID",
+        0x05 to "Physical",
+        0x06 to "Image",
+        0x07 to "Printer",
+        0x08 to "Mass Storage",
+        0x09 to "Hub",
+        0x0a to "CDC Data",
+        0x0b to "Smart Card",
+        0x0d to "Content Security",
+        0x0e to "Video",
+        0x0f to "Personal Healthcare",
+        0x10 to "Audio/Video",
+        0x11 to "Billboard",
+        0x12 to "USB-C Bridge",
+        0xdc to "Diagnostic",
+        0xe0 to "Wireless",
+        0xef to "Miscellaneous",
+        0xfe to "Application Specific",
+        0xff to "Vendor Specific",
+    )
+
+private fun hex2(value: Int): String = "0x" + (value and 0xff).toString(16).padStart(2, '0')
+
+fun usbClassName(code: Int): String? = if (code == 0) null else USB_CLASS_NAMES[code] ?: hex2(code)
+
+fun usbClassTriplet(cls: Int, sub: Int, proto: Int): String {
+    val name = usbClassName(cls) ?: hex2(cls)
+    return if (sub > 0 || proto > 0) "$name · ${hex2(sub)} · ${hex2(proto)}" else name
+}
+
+private val USB_SPEED_LABELS =
+    mapOf(
+        1 to "Low Speed",
+        2 to "Full Speed",
+        3 to "High Speed",
+        4 to "Wireless",
+        5 to "SuperSpeed",
+        6 to "SuperSpeed+",
+    )
+
+fun usbSpeedLabel(code: Int): String? = USB_SPEED_LABELS[code]
+
+fun bcdToVersion(bcd: Int): String = "${(bcd shr 8) and 0xff}.${(bcd shr 4) and 0x0f}${bcd and 0x0f}"
+
+fun formatVidPid(vendorId: Int, productId: Int): String {
+    fun hex4(value: Int) = (value and 0xffff).toString(16).padStart(4, '0')
+    return "${hex4(vendorId)}:${hex4(productId)}"
+}
+
+fun usbBackendLabel(backend: Int): String? = when (backend) {
+    1 -> "linux-sysfs"
+    2 -> "dynamic"
+    3 -> "darwin-iokit"
+    4 -> "windows-vboxusb"
+    else -> null
+}

app/src/main/java/io/nekohasekai/sfa/usbip/UsbUrb.kt

@@ -0,0 +1,29 @@
+package io.nekohasekai.sfa.usbip
+
+// Linux URB completion status conventions (negative errno) the usbip-server
+// translates back to the remote client.
+const val URB_OK = 0
+const val URB_EPIPE = -32 // stalled endpoint
+const val URB_EOVERFLOW = -75 // babble / buffer overrun
+const val URB_EPROTO = -71 // transport or protocol failure
+
+// Standard control requests the importing kernel issues during enumeration. Android
+// forwards control transfers raw, but SET_CONFIGURATION / SET_INTERFACE must also go
+// through UsbDeviceConnection so the host kernel's claimed-interface state stays in sync.
+const val USB_REQUEST_SET_CONFIGURATION = 0x09
+const val USB_REQUEST_SET_INTERFACE = 0x0b
+
+const val USB_TYPE_STANDARD = 0x00
+const val USB_TYPE_MASK = 0x60
+const val USB_DIR_IN = 0x80
+
+class UsbSetup(setup: ByteArray) {
+    val requestType: Int = setup[0].toInt() and 0xff
+    val request: Int = setup[1].toInt() and 0xff
+    val value: Int = (setup[2].toInt() and 0xff) or ((setup[3].toInt() and 0xff) shl 8)
+    val index: Int = (setup[4].toInt() and 0xff) or ((setup[5].toInt() and 0xff) shl 8)
+    val length: Int = (setup[6].toInt() and 0xff) or ((setup[7].toInt() and 0xff) shl 8)
+
+    val directionIn: Boolean get() = requestType and USB_DIR_IN != 0
+    val isStandard: Boolean get() = requestType and USB_TYPE_MASK == USB_TYPE_STANDARD
+}

app/src/main/java/io/nekohasekai/sfa/utils/CommandTarget.kt

@@ -34,7 +34,7 @@ object CommandTarget {
 
     fun libboxOptions(server: RemoteServer): RemoteConnectionOptions {
         val options = RemoteConnectionOptions()
-        options.setURL(server.url)
+        options.setURL(RemoteServer.connectURL(server.url))
         options.secret = server.secret
         return options
     }

app/src/main/res/values-fa/strings.xml

@@ -457,6 +457,7 @@
     <!-- STUN Test -->
     <!-- Tailscale -->
     <string name="tailscale_endpoints">نقاط اتصال</string>
+    <string name="title_services">سرویس‌ها</string>
 
     <string name="tailscale_status">وضعیت</string>
     <string name="tailscale_state">وضعیت</string>
@@ -611,4 +612,7 @@
     <string name="remote_invalid_url">نشانی سرور نامعتبر است: %1$s، قالب مورد انتظار host:port، http://host:port یا https://host:port است</string>
     <string name="remote_connect_failed">اتصال به سرور راه دور %1$s ناموفق بود</string>
     <string name="remote_disconnected_from">اتصال با سرور راه دور %1$s قطع شد</string>
+    <string name="remote_checking">در حال بررسی…</string>
+    <string name="remote_available">در دسترس</string>
+    <string name="remote_unavailable">در دسترس نیست</string>
 </resources>

app/src/main/res/values-ru-rRU/strings.xml

@@ -463,6 +463,7 @@
     <!-- STUN Test -->
     <!-- Tailscale -->
     <string name="tailscale_endpoints">Точки подключения</string>
+    <string name="title_services">Службы</string>
 
     <string name="tailscale_status">Статус</string>
     <string name="tailscale_state">Состояние</string>
@@ -617,4 +618,7 @@
     <string name="remote_invalid_url">Неверный URL сервера: %1$s, ожидается host:port, http://host:port или https://host:port</string>
     <string name="remote_connect_failed">Не удалось подключиться к удаленному серверу %1$s</string>
     <string name="remote_disconnected_from">Отключено от удаленного сервера %1$s</string>
+    <string name="remote_checking">Проверка…</string>
+    <string name="remote_available">Доступно</string>
+    <string name="remote_unavailable">Недоступно</string>
 </resources>

app/src/main/res/values-zh-rCN/strings.xml

@@ -454,6 +454,7 @@
     <!-- STUN Test -->
     <!-- Tailscale -->
     <string name="tailscale_endpoints">端点</string>
+    <string name="title_services">服务</string>
 
     <string name="tailscale_status">状态</string>
     <string name="tailscale_state">状态</string>
@@ -607,4 +608,7 @@
     <string name="remote_invalid_url">无效的服务器 URL: %1$s, 应为 host:port、http://host:port 或 https://host:port</string>
     <string name="remote_connect_failed">无法连接到远程服务器 %1$s</string>
     <string name="remote_disconnected_from">已断开与远程服务器 %1$s 的连接</string>
+    <string name="remote_checking">检查中…</string>
+    <string name="remote_available">可用</string>
+    <string name="remote_unavailable">不可用</string>
 </resources>

app/src/main/res/values-zh-rTW/strings.xml

@@ -457,6 +457,7 @@
     <!-- STUN Test -->
     <!-- Tailscale -->
     <string name="tailscale_endpoints">端點</string>
+    <string name="title_services">服務</string>
 
     <string name="tailscale_status">狀態</string>
     <string name="tailscale_state">狀態</string>
@@ -610,4 +611,7 @@
     <string name="remote_invalid_url">無效的伺服器 URL: %1$s, 應為 host:port、http://host:port 或 https://host:port</string>
     <string name="remote_connect_failed">無法連接到遠端伺服器 %1$s</string>
     <string name="remote_disconnected_from">已斷開與遠端伺服器 %1$s 的連接</string>
+    <string name="remote_checking">檢查中…</string>
+    <string name="remote_available">可用</string>
+    <string name="remote_unavailable">不可用</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -618,4 +618,40 @@
     <string name="remote_invalid_url">Invalid server URL: %1$s, expected host:port, http://host:port or https://host:port</string>
     <string name="remote_connect_failed">Failed to connect to remote server %1$s</string>
     <string name="remote_disconnected_from">Disconnected from remote server %1$s</string>
+    <string name="remote_checking">Checking…</string>
+    <string name="remote_available">Available</string>
+    <string name="remote_unavailable">Unavailable</string>
+
+    <string name="title_services">Services</string>
+    <string name="title_usbip">USB/IP</string>
+    <string name="usbip_with_tag">USB/IP: %1$s</string>
+    <string name="usbip_no_server">No usbip-server found</string>
+    <string name="usbip_no_devices">Pick a USB device to share it through this usbip-server.</string>
+    <string name="usbip_no_usb_devices">No USB devices connected</string>
+    <string name="usbip_connect_device">Connect USB device</string>
+    <string name="usbip_detach">Detach</string>
+    <string name="usbip_state_attaching">Attaching…</string>
+    <string name="usbip_state_ready">Ready</string>
+    <string name="usbip_state_error">Error</string>
+    <string name="usbip_state_idle">Idle</string>
+    <string name="usbip_state_attached">Attached</string>
+    <string name="usbip_state_unavailable">Unavailable</string>
+    <string name="usbip_identity">Identity</string>
+    <string name="usbip_connection">Connection</string>
+    <string name="usbip_class_interfaces">Class &amp; Interfaces</string>
+    <string name="usbip_product">Product</string>
+    <string name="usbip_serial">Serial number</string>
+    <string name="usbip_version">Version</string>
+    <string name="usbip_bus_id">Bus ID</string>
+    <string name="usbip_backend">Backend</string>
+    <string name="usbip_speed">Speed</string>
+    <string name="usbip_bus_device">Bus / Device</string>
+    <string name="usbip_device_class">Device class</string>
+    <string name="usbip_configuration">Configuration</string>
+    <string name="usbip_interface">Interface %1$d</string>
+    <string name="usbip_notification_title">USB/IP sharing</string>
+    <plurals name="usbip_notification_text">
+        <item quantity="one">Sharing %1$d USB device</item>
+        <item quantity="other">Sharing %1$d USB devices</item>
+    </plurals>
 </resources>