Add tether timeout monitor for Android 9+

mobile/src/main/java/be/mygod/vpnhotspot/LocalOnlyHotspotService.kt

@@ -4,11 +4,15 @@ import android.content.Intent
 import android.content.IntentFilter
 import android.content.res.Configuration
 import android.net.wifi.WifiManager
+import android.os.Build
+import android.os.Handler
 import androidx.annotation.RequiresApi
 import be.mygod.vpnhotspot.App.Companion.app
+import be.mygod.vpnhotspot.net.IpNeighbour
 import be.mygod.vpnhotspot.net.TetheringManager
 import be.mygod.vpnhotspot.net.TetheringManager.localOnlyTetheredIfaces
 import be.mygod.vpnhotspot.net.monitor.IpNeighbourMonitor
+import be.mygod.vpnhotspot.net.monitor.TetherTimeoutMonitor
 import be.mygod.vpnhotspot.util.StickyEvent1
 import be.mygod.vpnhotspot.util.broadcastReceiver
 import be.mygod.vpnhotspot.widget.SmartSnackbar
@@ -44,6 +48,9 @@ class LocalOnlyHotspotService : IpNeighbourMonitoringService(), CoroutineScope {
      */
     override val coroutineContext = newSingleThreadContext("LocalOnlyHotspotService") + Job()
     private var routingManager: RoutingManager? = null
+    private val handler = Handler()
+    @RequiresApi(28)
+    private var timeoutMonitor: TetherTimeoutMonitor? = null
     private var receiverRegistered = false
     private val receiver = broadcastReceiver { _, intent ->
         val ifaces = intent.localOnlyTetheredIfaces ?: return@broadcastReceiver
@@ -81,6 +88,8 @@ class LocalOnlyHotspotService : IpNeighbourMonitoringService(), CoroutineScope {
                     if (reservation == null) onFailed(-2) else {
                         this@LocalOnlyHotspotService.reservation = reservation
                         if (!receiverRegistered) {
+                            if (Build.VERSION.SDK_INT >= 28) timeoutMonitor = TetherTimeoutMonitor(
+                                    this@LocalOnlyHotspotService, handler, reservation::close)
                             registerReceiver(receiver, IntentFilter(TetheringManager.ACTION_TETHER_STATE_CHANGED))
                             receiverRegistered = true
                         }
@@ -123,6 +132,11 @@ class LocalOnlyHotspotService : IpNeighbourMonitoringService(), CoroutineScope {
         stopSelf()
     }
 
+    override fun onIpNeighbourAvailable(neighbours: List<IpNeighbour>) {
+        super.onIpNeighbourAvailable(neighbours)
+        if (Build.VERSION.SDK_INT >= 28) timeoutMonitor?.onClientsChanged(neighbours.isEmpty())
+    }
+
     override fun onDestroy() {
         binder.stop()
         unregisterReceiver(true)
@@ -130,15 +144,19 @@ class LocalOnlyHotspotService : IpNeighbourMonitoringService(), CoroutineScope {
     }
 
     private fun unregisterReceiver(exit: Boolean = false) {
+        if (receiverRegistered) {
+            unregisterReceiver(receiver)
+            IpNeighbourMonitor.unregisterCallback(this)
+            if (Build.VERSION.SDK_INT >= 28) {
+                timeoutMonitor?.close()
+                timeoutMonitor = null
+            }
+            receiverRegistered = false
+        }
         launch {
             routingManager?.destroy()
             routingManager = null
             if (exit) cancel()
         }
-        if (receiverRegistered) {
-            unregisterReceiver(receiver)
-            IpNeighbourMonitor.unregisterCallback(this)
-            receiverRegistered = false
-        }
     }
 }

mobile/src/main/java/be/mygod/vpnhotspot/RepeaterService.kt

@@ -10,10 +10,12 @@ import android.net.wifi.p2p.*
 import android.os.Build
 import android.os.Handler
 import android.os.Looper
+import androidx.annotation.RequiresApi
 import androidx.annotation.StringRes
 import androidx.core.content.edit
 import androidx.core.content.getSystemService
 import be.mygod.vpnhotspot.App.Companion.app
+import be.mygod.vpnhotspot.net.monitor.TetherTimeoutMonitor
 import be.mygod.vpnhotspot.net.wifi.WifiP2pManagerHelper
 import be.mygod.vpnhotspot.net.wifi.WifiP2pManagerHelper.deletePersistentGroup
 import be.mygod.vpnhotspot.net.wifi.WifiP2pManagerHelper.netId
@@ -87,6 +89,9 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
             set(value) {
                 field = value
                 groupChanged(value)
+                if (Build.VERSION.SDK_INT >= 28) value?.clientList?.let {
+                    timeoutMonitor?.onClientsChanged(it.isEmpty())
+                }
             }
         val groupChanged = StickyEvent1 { group }
         @Deprecated("Not initialized and no use at all since API 29")
@@ -118,6 +123,8 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
     private var channel: WifiP2pManager.Channel? = null
     private val binder = Binder()
     private val handler = Handler()
+    @RequiresApi(28)
+    private var timeoutMonitor: TetherTimeoutMonitor? = null
     private var receiverRegistered = false
     private val receiver = broadcastReceiver { _, intent ->
         when (intent.action) {
@@ -348,6 +355,7 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
      * startService Step 3
      */
     private fun doStartLocked(group: WifiP2pGroup) {
+        if (Build.VERSION.SDK_INT >= 28) timeoutMonitor = TetherTimeoutMonitor(this, handler, binder::shutdown)
         binder.group = group
         if (persistNextGroup) {
             networkName = group.networkName
@@ -389,6 +397,10 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
     }
     private fun cleanLocked() {
         unregisterReceiver()
+        if (Build.VERSION.SDK_INT >= 28) {
+            timeoutMonitor?.close()
+            timeoutMonitor = null
+        }
         routingManager?.destroy()
         routingManager = null
         status = Status.IDLE

mobile/src/main/java/be/mygod/vpnhotspot/net/monitor/TetherTimeoutMonitor.kt

@@ -0,0 +1,95 @@
+package be.mygod.vpnhotspot.net.monitor
+
+import android.content.Context
+import android.content.Intent
+import android.content.res.Resources
+import android.database.ContentObserver
+import android.os.BatteryManager
+import android.os.Handler
+import android.provider.Settings
+import androidx.annotation.RequiresApi
+import androidx.core.os.postDelayed
+import be.mygod.vpnhotspot.App.Companion.app
+import be.mygod.vpnhotspot.util.broadcastReceiver
+import be.mygod.vpnhotspot.util.intentFilter
+import timber.log.Timber
+import java.lang.IllegalArgumentException
+
+@RequiresApi(28)
+class TetherTimeoutMonitor(private val context: Context, private val handler: Handler, private val onTimeout: () -> Unit):
+        ContentObserver(handler), AutoCloseable {
+    /**
+     * config_wifi_framework_soft_ap_timeout_delay was introduced in Android 9.
+     *
+     * Source: https://android.googlesource.com/platform/frameworks/opt/net/wifi/+/87ed136/service/java/com/android/server/wifi/SoftApManager.java
+     */
+    companion object {
+        /**
+         * Whether soft AP will shut down after a timeout period when no devices are connected.
+         *
+         * Type: int (0 for false, 1 for true)
+         */
+        private const val SOFT_AP_TIMEOUT_ENABLED = "soft_ap_timeout_enabled"
+        /**
+         * Minimum limit to use for timeout delay if the value from overlay setting is too small.
+         */
+        private const val MIN_SOFT_AP_TIMEOUT_DELAY_MS = 600_000    // 10 minutes
+
+        private val enabled get() = Settings.Global.getInt(app.contentResolver, SOFT_AP_TIMEOUT_ENABLED, 1) == 1
+        private val timeout by lazy {
+            app.resources.getInteger(Resources.getSystem().getIdentifier(
+                    "config_wifi_framework_soft_ap_timeout_delay", "integer", "android")).let { delay ->
+                if (delay < MIN_SOFT_AP_TIMEOUT_DELAY_MS) {
+                    Timber.w("Overriding timeout delay with minimum limit value: $delay < $MIN_SOFT_AP_TIMEOUT_DELAY_MS")
+                    MIN_SOFT_AP_TIMEOUT_DELAY_MS
+                } else delay
+            }
+        }
+    }
+
+    private var charging = when (context.registerReceiver(null, intentFilter(Intent.ACTION_BATTERY_CHANGED))
+            ?.getIntExtra(BatteryManager.EXTRA_STATUS, -1)) {
+        BatteryManager.BATTERY_STATUS_CHARGING, BatteryManager.BATTERY_STATUS_FULL -> true
+        null, -1 -> false.also { Timber.w(Exception("Battery status not found")) }
+        else -> false
+    }
+    private var noClient = true
+    private var timeoutPending = false
+
+    private val receiver = broadcastReceiver { _, intent ->
+        charging = when (intent.action) {
+            Intent.ACTION_POWER_CONNECTED -> true
+            Intent.ACTION_POWER_DISCONNECTED -> false
+            else -> throw IllegalArgumentException("Invalid intent.action")
+        }
+        onChange(true)
+    }.also {
+        context.registerReceiver(it, intentFilter(Intent.ACTION_POWER_CONNECTED, Intent.ACTION_POWER_DISCONNECTED))
+        context.contentResolver.registerContentObserver(Settings.Global.getUriFor(SOFT_AP_TIMEOUT_ENABLED), true, this)
+    }
+
+    override fun close() {
+        context.unregisterReceiver(receiver)
+        context.contentResolver.unregisterContentObserver(this)
+    }
+
+    fun onClientsChanged(noClient: Boolean) {
+        this.noClient = noClient
+        onChange(true)
+    }
+
+    override fun onChange(selfChange: Boolean) {
+        // super.onChange(selfChange) should not do anything
+        if (enabled && noClient && !charging) {
+            if (!timeoutPending) {
+                handler.postDelayed(timeout.toLong(), this, onTimeout)
+                timeoutPending = true
+            }
+        } else {
+            if (timeoutPending) {
+                handler.removeCallbacksAndMessages(this)
+                timeoutPending = false
+            }
+        }
+    }
+}

mobile/src/main/java/be/mygod/vpnhotspot/util/Utils.kt

@@ -58,11 +58,7 @@ fun broadcastReceiver(receiver: (Context, Intent) -> Unit) = object : BroadcastR
     override fun onReceive(context: Context, intent: Intent) = receiver(context, intent)
 }
 
-fun intentFilter(vararg actions: String): IntentFilter {
+fun intentFilter(vararg actions: String) = IntentFilter().also { actions.forEach(it::addAction) }
-    val result = IntentFilter()
-    actions.forEach { result.addAction(it) }
-    return result
-}
 
 @BindingAdapter("android:src")
 fun setImageResource(imageView: ImageView, @DrawableRes resource: Int) = imageView.setImageResource(resource)
@@ -74,11 +70,11 @@ fun setVisibility(view: View, value: Boolean) {
 
 fun makeIpSpan(ip: InetAddress) = ip.hostAddress.let {
     // exclude all bogon IP addresses supported by Android APIs
-    if (app.hasTouch && !(ip.isMulticastAddress || ip.isAnyLocalAddress || ip.isLoopbackAddress ||
+    if (!app.hasTouch || ip.isMulticastAddress || ip.isAnyLocalAddress || ip.isLoopbackAddress ||
-                    ip.isLinkLocalAddress || ip.isSiteLocalAddress || ip.isMCGlobal || ip.isMCNodeLocal ||
+            ip.isLinkLocalAddress || ip.isSiteLocalAddress || ip.isMCGlobal || ip.isMCNodeLocal ||
-                    ip.isMCLinkLocal || ip.isMCSiteLocal || ip.isMCOrgLocal)) SpannableString(it).apply {
+            ip.isMCLinkLocal || ip.isMCSiteLocal || ip.isMCOrgLocal) it else SpannableString(it).apply {
         setSpan(CustomTabsUrlSpan("https://ipinfo.io/$it"), 0, length, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE)
-    } else it
+    }
 }
 fun makeMacSpan(mac: String) = if (app.hasTouch) SpannableString(mac).apply {
     setSpan(CustomTabsUrlSpan("https://macvendors.co/results/$mac"), 0, length, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE)