Support VPN over any native tethering

First big refactoring of this app.

mobile/src/main/AndroidManifest.xml

@@ -3,7 +3,10 @@
           package="be.mygod.vpnhotspot">
 
     <uses-feature android:name="android.hardware.wifi"/>
-    <uses-feature android:name="android.hardware.wifi.direct" android:required="false"/>
+    <uses-feature
+        android:name="android.hardware.wifi.direct"
+        android:required="false"/>
+
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
     <uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
@@ -17,8 +20,8 @@
         android:theme="@style/AppTheme">
         <activity
             android:name=".MainActivity"
-            android:launchMode="singleInstance"
+            android:label="@string/app_name"
-            android:label="@string/app_name">
+            android:launchMode="singleInstance">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN"/>
 
@@ -26,13 +29,10 @@
             </intent-filter>
         </activity>
 
-        <service android:name=".HotspotService">
+        <service android:name=".RepeaterService">
+        </service>
+        <service android:name=".TetheringService">
         </service>
-
-        <activity
-            android:name=".SettingsActivity"
-            android:label="@string/title_activity_settings"
-            android:parentActivityName=".MainActivity"/>
     </application>
 
 </manifest>

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

@@ -4,10 +4,8 @@ import android.app.Application
 import android.app.NotificationChannel
 import android.app.NotificationManager
 import android.content.SharedPreferences
-import android.content.res.Resources
 import android.os.Build
 import android.preference.PreferenceManager
-import java.net.NetworkInterface
 
 class App : Application() {
     companion object {
@@ -18,21 +16,10 @@ class App : Application() {
         super.onCreate()
         app = this
         if (Build.VERSION.SDK_INT >= 26) getSystemService(NotificationManager::class.java)
-                .createNotificationChannel(NotificationChannel(HotspotService.CHANNEL,
+                .createNotificationChannel(NotificationChannel(RepeaterService.CHANNEL,
                         "Hotspot Service", NotificationManager.IMPORTANCE_LOW))
-        pref = PreferenceManager.getDefaultSharedPreferences(this)
-        val wifiRegexes = resources.getStringArray(Resources.getSystem()
-                .getIdentifier("config_tether_wifi_regexs", "array", "android"))
-                .map { it.toPattern() }
-        wifiInterfaces = NetworkInterface.getNetworkInterfaces().asSequence()
-                .map { it.name }
-                .filter { ifname -> wifiRegexes.any { it.matcher(ifname).matches() } }
-                .sorted().toList().toTypedArray()
-        val wifiInterface = wifiInterfaces.singleOrNull()
-        if (wifiInterface != null && pref.getString(HotspotService.KEY_WIFI, null) == null)
-            pref.edit().putString(HotspotService.KEY_WIFI, wifiInterface).apply()
     }
 
-    lateinit var pref: SharedPreferences
+    val pref: SharedPreferences by lazy { PreferenceManager.getDefaultSharedPreferences(this) }
-    lateinit var wifiInterfaces: Array<String>
+    val dns: String get() = app.pref.getString("service.dns", "8.8.8.8:53")
 }

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

@@ -0,0 +1,11 @@
+package be.mygod.vpnhotspot
+
+import android.databinding.BindingAdapter
+import android.support.annotation.DrawableRes
+import android.widget.ImageView
+
+object DataBindingAdapters {
+    @JvmStatic
+    @BindingAdapter("android:src")
+    fun setImageResource(imageView: ImageView, @DrawableRes resource: Int) = imageView.setImageResource(resource)
+}

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

@@ -1,360 +0,0 @@
-package be.mygod.vpnhotspot
-
-import android.app.PendingIntent
-import android.app.Service
-import android.content.Context
-import android.content.Intent
-import android.net.*
-import android.net.wifi.WifiConfiguration
-import android.net.wifi.WifiManager
-import android.net.wifi.p2p.WifiP2pGroup
-import android.net.wifi.p2p.WifiP2pInfo
-import android.net.wifi.p2p.WifiP2pManager
-import android.os.Binder
-import android.os.Looper
-import android.support.v4.app.NotificationCompat
-import android.support.v4.content.ContextCompat
-import android.support.v4.content.LocalBroadcastManager
-import android.util.Log
-import android.widget.Toast
-import be.mygod.vpnhotspot.App.Companion.app
-import java.net.InetAddress
-import java.util.regex.Pattern
-
-class HotspotService : Service(), WifiP2pManager.ChannelListener {
-    companion object {
-        const val CHANNEL = "hotspot"
-        const val STATUS_CHANGED = "be.mygod.vpnhotspot.HotspotService.STATUS_CHANGED"
-        const val KEY_UPSTREAM = "service.upstream"
-        const val KEY_WIFI = "service.wifi"
-        private const val TAG = "HotspotService"
-        // constants from WifiManager
-        private const val WIFI_AP_STATE_CHANGED_ACTION = "android.net.wifi.WIFI_AP_STATE_CHANGED"
-        private const val WIFI_AP_STATE_ENABLED = 13
-
-        private val upstream get() = app.pref.getString(KEY_UPSTREAM, "tun0")
-        private val wifi get() = app.pref.getString(KEY_WIFI, "wlan0")
-        private val dns get() = app.pref.getString("service.dns", "8.8.8.8:53")
-
-        /**
-         * Matches the output of dumpsys wifip2p. This part is available since Android 4.2.
-         *
-         * Related sources:
-         *   https://android.googlesource.com/platform/frameworks/base/+/f0afe4144d09aa9b980cffd444911ab118fa9cbe%5E%21/wifi/java/android/net/wifi/p2p/WifiP2pService.java
-         *   https://android.googlesource.com/platform/frameworks/opt/net/wifi/+/a8d5e40/service/java/com/android/server/wifi/p2p/WifiP2pServiceImpl.java#639
-         *
-         *   https://android.googlesource.com/platform/frameworks/base.git/+/android-5.0.0_r1/core/java/android/net/NetworkInfo.java#433
-         *   https://android.googlesource.com/platform/frameworks/base.git/+/220871a/core/java/android/net/NetworkInfo.java#415
-         */
-        private val patternNetworkInfo = "^mNetworkInfo .* (isA|a)vailable: (true|false)".toPattern(Pattern.MULTILINE)
-
-        private val isWifiApEnabledMethod = WifiManager::class.java.getDeclaredMethod("isWifiApEnabled")
-        val WifiManager.isWifiApEnabled get() = isWifiApEnabledMethod.invoke(this) as Boolean
-
-        private val request by lazy {
-            /* We don't know how to specify the interface we're interested in, so we will listen for everything.
-             * However, we need to remove all default capabilities defined in NetworkCapabilities constructor.
-             * Also this unfortunately doesn't work for P2P/AP connectivity changes.
-             */
-            NetworkRequest.Builder()
-                    .removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)
-                    .removeCapability(NetworkCapabilities.NET_CAPABILITY_TRUSTED)
-                    .removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)
-                    .build()
-        }
-
-        init {
-            isWifiApEnabledMethod.isAccessible = true
-        }
-    }
-
-    enum class Status {
-        IDLE, STARTING, ACTIVE_P2P, ACTIVE_AP
-    }
-
-    inner class HotspotBinder : Binder() {
-        val service get() = this@HotspotService
-        var data: MainActivity.Data? = null
-
-        fun shutdown() = when (status) {
-            Status.ACTIVE_P2P -> removeGroup()
-            else -> clean()
-        }
-
-        fun reapplyRouting() {
-            val routing = routing
-            routing?.stop()
-            try {
-                if (!when (status) {
-                    Status.ACTIVE_P2P -> initP2pRouting(routing!!.downstream, routing.hostAddress)
-                    Status.ACTIVE_AP -> initApRouting(routing!!.hostAddress)
-                    else -> false
-                }) Toast.makeText(this@HotspotService, "Something went wrong, please check logcat.",
-                        Toast.LENGTH_SHORT).show()
-            } catch (e: Exception) {
-                Toast.makeText(this@HotspotService, e.message, Toast.LENGTH_SHORT).show()
-                return
-            }
-        }
-    }
-
-    private val connectivityManager by lazy { getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager }
-    private val wifiManager by lazy { getSystemService(Context.WIFI_SERVICE) as WifiManager }
-    private val p2pManager by lazy { getSystemService(Context.WIFI_P2P_SERVICE) as WifiP2pManager }
-    private var _channel: WifiP2pManager.Channel? = null
-    private val channel: WifiP2pManager.Channel get() {
-        if (_channel == null) onChannelDisconnected()
-        return _channel!!
-    }
-    lateinit var group: WifiP2pGroup
-        private set
-    private var apConfiguration: WifiConfiguration? = null
-    private val binder = HotspotBinder()
-    private var receiverRegistered = false
-    private val receiver = broadcastReceiver { _, intent ->
-        when (intent.action) {
-            WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION ->
-                if (intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, 0) ==
-                        WifiP2pManager.WIFI_P2P_STATE_DISABLED) clean() // ignore P2P enabled
-            WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION -> {
-                onP2pConnectionChanged(intent.getParcelableExtra(WifiP2pManager.EXTRA_WIFI_P2P_INFO),
-                        intent.getParcelableExtra(WifiP2pManager.EXTRA_NETWORK_INFO),
-                        intent.getParcelableExtra(WifiP2pManager.EXTRA_WIFI_P2P_GROUP))
-            }
-            WIFI_AP_STATE_CHANGED_ACTION ->
-                if (intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, 0) != WIFI_AP_STATE_ENABLED) clean()
-        }
-    }
-    private var netListenerRegistered = false
-    private val netListener = object : ConnectivityManager.NetworkCallback() {
-        /**
-         * Obtaining ifname in onLost doesn't work so we need to cache it in onAvailable.
-         */
-        private val ifnameCache = HashMap<Network, String>()
-        private val Network.ifname: String? get() {
-            var result = ifnameCache[this]
-            if (result == null) {
-                result = connectivityManager.getLinkProperties(this)?.interfaceName
-                if (result != null) ifnameCache.put(this, result)
-            }
-            return result
-        }
-
-        override fun onAvailable(network: Network?) {
-            val routing = routing ?: return
-            val ifname = network?.ifname
-            debugLog(TAG, "onAvailable: $ifname")
-            if (ifname == routing.upstream) routing.start()
-        }
-
-        override fun onLost(network: Network?) {
-            val routing = routing ?: return
-            val ifname = network?.ifname
-            debugLog(TAG, "onLost: $ifname")
-            when (ifname) {
-                routing.downstream -> clean()
-                routing.upstream -> routing.stop()
-            }
-        }
-    }
-
-    val ssid get() = when (status) {
-        HotspotService.Status.ACTIVE_P2P -> group.networkName
-        HotspotService.Status.ACTIVE_AP -> apConfiguration?.SSID ?: "Unknown"
-        else -> null
-    }
-    val password get() = when (status) {
-        HotspotService.Status.ACTIVE_P2P -> group.passphrase
-        HotspotService.Status.ACTIVE_AP -> apConfiguration?.preSharedKey
-        else -> null
-    }
-
-    var routing: Routing? = null
-        private set
-
-    var status = Status.IDLE
-        private set(value) {
-            if (field == value) return
-            field = value
-            LocalBroadcastManager.getInstance(this).sendBroadcast(Intent(STATUS_CHANGED))
-        }
-
-    private fun formatReason(reason: Int) = when (reason) {
-        WifiP2pManager.ERROR -> "ERROR"
-        WifiP2pManager.P2P_UNSUPPORTED -> "P2P_UNSUPPORTED"
-        WifiP2pManager.BUSY -> "BUSY"
-        WifiP2pManager.NO_SERVICE_REQUESTS -> "NO_SERVICE_REQUESTS"
-        else -> "unknown reason: $reason"
-    }
-
-    override fun onBind(intent: Intent) = binder
-
-    override fun onChannelDisconnected() {
-        _channel = p2pManager.initialize(this, Looper.getMainLooper(), this)
-    }
-
-    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
-        if (status != Status.IDLE) return START_NOT_STICKY
-        status = Status.STARTING
-        val matcher = patternNetworkInfo.matcher(loggerSu("dumpsys ${Context.WIFI_P2P_SERVICE}"))
-        when {
-            !matcher.find() -> startFailure("Root unavailable")
-            matcher.group(2) == "true" -> {
-                unregisterReceiver()
-                registerReceiver(receiver, intentFilter(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION,
-                        WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION))
-                receiverRegistered = true
-                p2pManager.requestGroupInfo(channel, {
-                    when {
-                        it == null -> doStart()
-                        it.isGroupOwner -> doStart(it)
-                        else -> {
-                            Log.i(TAG, "Removing old group ($it)")
-                            p2pManager.removeGroup(channel, object : WifiP2pManager.ActionListener {
-                                override fun onSuccess() = doStart()
-                                override fun onFailure(reason: Int) {
-                                    Toast.makeText(this@HotspotService,
-                                            "Failed to remove old P2P group (${formatReason(reason)})",
-                                            Toast.LENGTH_SHORT).show()
-                                }
-                            })
-                        }
-                    }
-                })
-            }
-            wifiManager.isWifiApEnabled -> {
-                unregisterReceiver()
-                registerReceiver(receiver, intentFilter(WIFI_AP_STATE_CHANGED_ACTION))
-                receiverRegistered = true
-                try {
-                    if (initApRouting()) {
-                        connectivityManager.registerNetworkCallback(request, netListener)
-                        netListenerRegistered = true
-                        apConfiguration = NetUtils.loadApConfiguration()
-                        status = Status.ACTIVE_AP
-                        showNotification()
-                    } else startFailure("Something went wrong, please check logcat.", group)
-                } catch (e: Routing.InterfaceNotFoundException) {
-                    startFailure(e.message, group)
-                }
-            }
-            else -> startFailure("Wi-Fi direct unavailable and hotspot disabled, please enable either")
-        }
-        return START_NOT_STICKY
-    }
-    private fun initApRouting(owner: InetAddress? = null): Boolean {
-        val routing = Routing(upstream, wifi, owner).rule().forward().dnsRedirect(dns)
-        return if (routing.start()) {
-            this.routing = routing
-            true
-        } else {
-            routing.stop()
-            this.routing = null
-            false
-        }
-    }
-
-    private fun startFailure(msg: String?, group: WifiP2pGroup? = null) {
-        Toast.makeText(this, msg, Toast.LENGTH_SHORT).show()
-        showNotification()
-        if (group != null) removeGroup() else clean()
-    }
-    private fun doStart() = p2pManager.createGroup(channel, object : WifiP2pManager.ActionListener {
-        override fun onFailure(reason: Int) = startFailure("Failed to create P2P group (${formatReason(reason)})")
-        override fun onSuccess() { }    // wait for WIFI_P2P_CONNECTION_CHANGED_ACTION to fire
-    })
-    private fun doStart(group: WifiP2pGroup) {
-        this.group = group
-        status = Status.ACTIVE_P2P
-        showNotification(group)
-    }
-    private fun showNotification(group: WifiP2pGroup? = null) {
-        val builder = NotificationCompat.Builder(this, CHANNEL)
-                .setWhen(0)
-                .setColor(ContextCompat.getColor(this, R.color.colorPrimary))
-                .setContentTitle(group?.networkName ?: ssid ?: "Connecting...")
-                .setSmallIcon(R.drawable.ic_device_wifi_tethering)
-                .setContentIntent(PendingIntent.getActivity(this, 0,
-                        Intent(this, MainActivity::class.java), PendingIntent.FLAG_UPDATE_CURRENT))
-        if (group != null) builder.setContentText(resources.getQuantityString(R.plurals.notification_connected_devices,
-                group.clientList.size, group.clientList.size))
-        startForeground(1, builder.build())
-    }
-
-    private fun onP2pConnectionChanged(info: WifiP2pInfo, net: NetworkInfo?, group: WifiP2pGroup) {
-        if (routing == null) onGroupCreated(info, group) else if (!group.isGroupOwner) {    // P2P shutdown
-            clean()
-            return
-        }
-        this.group = group
-        binder.data?.onGroupChanged()
-        showNotification(group)
-        Log.d(TAG, "P2P connection changed: $info\n$net\n$group")
-    }
-    private fun onGroupCreated(info: WifiP2pInfo, group: WifiP2pGroup) {
-        val owner = info.groupOwnerAddress
-        val downstream = group.`interface`
-        if (!info.groupFormed || !info.isGroupOwner || downstream == null || owner == null) return
-        receiverRegistered = true
-        try {
-            if (initP2pRouting(downstream, owner)) {
-                connectivityManager.registerNetworkCallback(request, netListener)
-                netListenerRegistered = true
-                doStart(group)
-            } else startFailure("Something went wrong, please check logcat.", group)
-        } catch (e: Routing.InterfaceNotFoundException) {
-            startFailure(e.message, group)
-            return
-        }
-    }
-    private fun initP2pRouting(downstream: String, owner: InetAddress): Boolean {
-        val routing = Routing(upstream, downstream, owner)
-                .ipForward()   // Wi-Fi direct doesn't enable ip_forward
-                .rule().forward().dnsRedirect(dns)
-        return if (routing.start()) {
-            this.routing = routing
-            true
-        } else {
-            routing.stop()
-            this.routing = null
-            false
-        }
-    }
-
-    private fun removeGroup() {
-        p2pManager.removeGroup(channel, object : WifiP2pManager.ActionListener {
-            override fun onSuccess() = clean()
-            override fun onFailure(reason: Int) {
-                if (reason == WifiP2pManager.BUSY) clean() else {   // assuming it's already gone
-                    Toast.makeText(this@HotspotService, "Failed to remove P2P group (${formatReason(reason)})",
-                            Toast.LENGTH_SHORT).show()
-                    status = Status.ACTIVE_P2P
-                    LocalBroadcastManager.getInstance(this@HotspotService).sendBroadcast(Intent(STATUS_CHANGED))
-                }
-            }
-        })
-    }
-    private fun unregisterReceiver() {
-        if (netListenerRegistered) {
-            connectivityManager.unregisterNetworkCallback(netListener)
-            netListenerRegistered = false
-        }
-        if (receiverRegistered) {
-            unregisterReceiver(receiver)
-            receiverRegistered = false
-        }
-    }
-    private fun clean() {
-        unregisterReceiver()
-        if (routing?.stop() == false)
-            Toast.makeText(this, "Something went wrong, please check logcat.", Toast.LENGTH_SHORT).show()
-        routing = null
-        status = Status.IDLE
-        stopForeground(true)
-    }
-
-    override fun onDestroy() {
-        if (status != Status.IDLE) binder.shutdown()
-        super.onDestroy()
-    }
-}

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

@@ -1,160 +1,42 @@
 package be.mygod.vpnhotspot
 
-import android.content.*
-import android.databinding.BaseObservable
-import android.databinding.Bindable
 import android.databinding.DataBindingUtil
-import android.net.wifi.p2p.WifiP2pDevice
 import android.os.Bundle
-import android.os.IBinder
+import android.support.design.widget.BottomNavigationView
-import android.support.v4.content.ContextCompat
+import android.support.v4.app.Fragment
-import android.support.v4.content.LocalBroadcastManager
 import android.support.v7.app.AppCompatActivity
-import android.support.v7.widget.DefaultItemAnimator
-import android.support.v7.widget.LinearLayoutManager
-import android.support.v7.widget.RecyclerView
-import android.support.v7.widget.Toolbar
-import android.view.LayoutInflater
 import android.view.MenuItem
-import android.view.ViewGroup
 import be.mygod.vpnhotspot.databinding.ActivityMainBinding
-import be.mygod.vpnhotspot.databinding.ListitemClientBinding
-
-class MainActivity : AppCompatActivity(), ServiceConnection, Toolbar.OnMenuItemClickListener {
-    inner class Data : BaseObservable() {
-        val switchEnabled: Boolean
-            @Bindable get() = when (binder?.service?.status) {
-                HotspotService.Status.IDLE, HotspotService.Status.ACTIVE_P2P, HotspotService.Status.ACTIVE_AP -> true
-                else -> false
-            }
-        var serviceStarted: Boolean
-            @Bindable get() = when (binder?.service?.status) {
-                HotspotService.Status.STARTING, HotspotService.Status.ACTIVE_P2P, HotspotService.Status.ACTIVE_AP ->
-                    true
-                else -> false
-            }
-            set(value) {
-                val binder = binder
-                when (binder?.service?.status) {
-                    HotspotService.Status.IDLE ->
-                        if (value) ContextCompat.startForegroundService(this@MainActivity,
-                                Intent(this@MainActivity, HotspotService::class.java))
-                    HotspotService.Status.ACTIVE_P2P, HotspotService.Status.ACTIVE_AP -> if (!value) binder.shutdown()
-                }
-            }
-
-        val ssid @Bindable get() = binder?.service?.ssid ?: "Service inactive"
-        val password @Bindable get() = binder?.service?.password ?: ""
-
-        fun onStatusChanged() {
-            notifyPropertyChanged(BR.switchEnabled)
-            notifyPropertyChanged(BR.serviceStarted)
-            onGroupChanged()
-        }
-        fun onGroupChanged() {
-            notifyPropertyChanged(BR.ssid)
-            notifyPropertyChanged(BR.password)
-            adapter.fetchClients()
-        }
-
-        val statusListener = broadcastReceiver { _, _ -> onStatusChanged() }
-    }
-
-    class ClientViewHolder(val binding: ListitemClientBinding) : RecyclerView.ViewHolder(binding.root)
-    inner class ClientAdapter : RecyclerView.Adapter<ClientViewHolder>() {
-        private var owner: WifiP2pDevice? = null
-        private lateinit var clients: MutableCollection<WifiP2pDevice>
-        private lateinit var arpCache: Map<String, String>
-
-        fun fetchClients() {
-            val binder = binder
-            if (binder?.service?.status == HotspotService.Status.ACTIVE_P2P) {
-                owner = binder.service.group.owner
-                clients = binder.service.group.clientList
-                arpCache = NetUtils.arp(binder.service.routing?.downstream)
-            } else owner = null
-            notifyDataSetChanged()  // recreate everything
-            binding.swipeRefresher.isRefreshing = false
-        }
-
-        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
-                ClientViewHolder(ListitemClientBinding.inflate(LayoutInflater.from(parent.context)))
-
-        override fun onBindViewHolder(holder: ClientViewHolder, position: Int) {
-            val device = when (position) {
-                0 -> owner
-                else -> clients.elementAt(position - 1)
-            }
-            holder.binding.device = device
-            holder.binding.ipAddress = when (position) {
-                0 -> binder?.service?.routing?.hostAddress?.hostAddress
-                else -> arpCache[device?.deviceAddress]
-            }
-            holder.binding.executePendingBindings()
-        }
-
-        override fun getItemCount() = if (owner == null) 0 else 1 + clients.size
-    }
 
+class MainActivity : AppCompatActivity(), BottomNavigationView.OnNavigationItemSelectedListener {
     private lateinit var binding: ActivityMainBinding
-    private val data = Data()
-    private val adapter = ClientAdapter()
-    private var binder: HotspotService.HotspotBinder? = null
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
-        binding.data = data
+        binding.navigation.setOnNavigationItemSelectedListener(this)
-        binding.clients.layoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)
+        onNavigationItemSelected(binding.navigation.menu.getItem(0))
-        val animator = DefaultItemAnimator()
-        animator.supportsChangeAnimations = false   // prevent fading-in/out when rebinding
-        binding.clients.itemAnimator = animator
-        binding.clients.adapter = adapter
-        binding.toolbar.inflateMenu(R.menu.main)
-        binding.toolbar.setOnMenuItemClickListener(this)
-        binding.swipeRefresher.setOnRefreshListener { adapter.fetchClients() }
     }
 
-    override fun onMenuItemClick(item: MenuItem): Boolean = when (item.itemId) {
+    override fun onNavigationItemSelected(item: MenuItem) = when (item.itemId) {
-        R.id.reapply -> {
+        R.id.navigation_repeater -> {
-            val binder = binder
+            item.isChecked = true
-            when (binder?.service?.status) {
+            displayFragment(RepeaterFragment())
-                HotspotService.Status.IDLE -> Routing.clean()
-                HotspotService.Status.ACTIVE_P2P, HotspotService.Status.ACTIVE_AP -> binder.reapplyRouting()
-            }
             true
         }
-        R.id.settings -> {
+        R.id.navigation_tethering -> {
-            startActivity(Intent(this, SettingsActivity::class.java))
+            item.isChecked = true
+            displayFragment(TetheringFragment())
+            true
+        }
+        R.id.navigation_settings -> {
+            item.isChecked = true
+            displayFragment(SettingsFragment())
             true
         }
         else -> false
     }
 
-    override fun onStart() {
+    private fun displayFragment(fragment: Fragment) =
-        super.onStart()
+            supportFragmentManager.beginTransaction().replace(R.id.fragmentHolder, fragment).commit()
-        bindService(Intent(this, HotspotService::class.java), this, Context.BIND_AUTO_CREATE)
-    }
-
-    override fun onStop() {
-        onServiceDisconnected(null)
-        unbindService(this)
-        super.onStop()
-    }
-
-    override fun onServiceConnected(name: ComponentName?, service: IBinder?) {
-        val binder = service as HotspotService.HotspotBinder
-        binder.data = data
-        this.binder = binder
-        data.onStatusChanged()
-        LocalBroadcastManager.getInstance(this)
-                .registerReceiver(data.statusListener, intentFilter(HotspotService.STATUS_CHANGED))
-    }
-
-    override fun onServiceDisconnected(name: ComponentName?) {
-        binder?.data = null
-        binder = null
-        LocalBroadcastManager.getInstance(this).unregisterReceiver(data.statusListener)
-        data.onStatusChanged()
-    }
 }

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

@@ -1,16 +1,20 @@
 package be.mygod.vpnhotspot
 
-import android.net.wifi.WifiConfiguration
+import android.net.ConnectivityManager
-import android.util.Log
-import java.io.DataInputStream
 import java.io.File
-import java.io.IOException
 
 object NetUtils {
-    private const val TAG = "NetUtils"
+    // hidden constants from ConnectivityManager
+    const val ACTION_TETHER_STATE_CHANGED = "android.net.conn.TETHER_STATE_CHANGED"
+    const val EXTRA_ACTIVE_TETHER = "tetherArray"
+
     private val spaces = " +".toPattern()
     private val mac = "^([0-9a-f]{2}:){5}[0-9a-f]{2}$".toPattern()
 
+    private val getTetheredIfaces = ConnectivityManager::class.java.getDeclaredMethod("getTetheredIfaces")
+    @Suppress("UNCHECKED_CAST")
+    val ConnectivityManager.tetheredIfaces get() = getTetheredIfaces.invoke(this) as Array<String>
+
     fun arp(iface: String? = null) = File("/proc/net/arp").bufferedReader().useLines {
         // IP address       HW type     Flags       HW address            Mask     Device
         it.map { it.split(spaces) }
@@ -19,34 +23,4 @@ object NetUtils {
                         mac.matcher(it[3]).matches() }
                 .associateBy({ it[3] }, { it[0] })
     }
-
-    /**
-     * Load AP configuration from persistent storage.
-     *
-     * Based on: https://android.googlesource.com/platform/frameworks/opt/net/wifi/+/0cafbe0/service/java/com/android/server/wifi/WifiApConfigStore.java#138
-     */
-    fun loadApConfiguration(): WifiConfiguration? = try {
-        loggerSuStream("cat /data/misc/wifi/softap.conf").buffered().use {
-            val data = DataInputStream(it)
-            val version = data.readInt()
-            when (version) {
-                1, 2 -> {
-                    val config = WifiConfiguration()
-                    config.SSID = data.readUTF()
-                    if (version >= 2) data.readLong()   // apBand and apChannel
-                    val authType = data.readInt()
-                    config.allowedKeyManagement.set(authType)
-                    if (authType != WifiConfiguration.KeyMgmt.NONE) config.preSharedKey = data.readUTF()
-                    config
-                }
-                else -> {
-                    Log.e(TAG, "Bad version on hotspot configuration file $version")
-                    null
-                }
-            }
-        }
-    } catch (e: IOException) {
-        Log.e(TAG, "Error reading hotspot configuration $e")
-        null
-    }
 }

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

@@ -0,0 +1,146 @@
+package be.mygod.vpnhotspot
+
+import android.content.ComponentName
+import android.content.Context
+import android.content.Intent
+import android.content.ServiceConnection
+import android.databinding.BaseObservable
+import android.databinding.Bindable
+import android.databinding.DataBindingUtil
+import android.net.wifi.p2p.WifiP2pDevice
+import android.os.Bundle
+import android.os.IBinder
+import android.support.v4.app.Fragment
+import android.support.v4.content.ContextCompat
+import android.support.v4.content.LocalBroadcastManager
+import android.support.v7.widget.DefaultItemAnimator
+import android.support.v7.widget.LinearLayoutManager
+import android.support.v7.widget.RecyclerView
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import be.mygod.vpnhotspot.databinding.FragmentRepeaterBinding
+import be.mygod.vpnhotspot.databinding.ListitemClientBinding
+
+class RepeaterFragment : Fragment(), ServiceConnection {
+    inner class Data : BaseObservable() {
+        val switchEnabled: Boolean
+            @Bindable get() = when (binder?.service?.status) {
+                RepeaterService.Status.IDLE, RepeaterService.Status.ACTIVE -> true
+                else -> false
+            }
+        var serviceStarted: Boolean
+            @Bindable get() = when (binder?.service?.status) {
+                RepeaterService.Status.STARTING, RepeaterService.Status.ACTIVE -> true
+                else -> false
+            }
+            set(value) {
+                val binder = binder
+                when (binder?.service?.status) {
+                    RepeaterService.Status.IDLE ->
+                        if (value) {
+                            val context = context!!
+                            ContextCompat.startForegroundService(context, Intent(context, RepeaterService::class.java))
+                        }
+                    RepeaterService.Status.ACTIVE -> if (!value) binder.shutdown()
+                }
+            }
+
+        val ssid @Bindable get() = binder?.service?.ssid ?: "Service inactive"
+        val password @Bindable get() = binder?.service?.password ?: ""
+
+        fun onStatusChanged() {
+            notifyPropertyChanged(BR.switchEnabled)
+            notifyPropertyChanged(BR.serviceStarted)
+            onGroupChanged()
+        }
+        fun onGroupChanged() {
+            notifyPropertyChanged(BR.ssid)
+            notifyPropertyChanged(BR.password)
+            adapter.fetchClients()
+        }
+
+        val statusListener = broadcastReceiver { _, _ -> onStatusChanged() }
+    }
+
+    class ClientViewHolder(val binding: ListitemClientBinding) : RecyclerView.ViewHolder(binding.root)
+    inner class ClientAdapter : RecyclerView.Adapter<ClientViewHolder>() {
+        private var owner: WifiP2pDevice? = null
+        private lateinit var clients: MutableCollection<WifiP2pDevice>
+        private lateinit var arpCache: Map<String, String>
+
+        fun fetchClients() {
+            val binder = binder
+            if (binder?.service?.status == RepeaterService.Status.ACTIVE) {
+                owner = binder.service.group.owner
+                clients = binder.service.group.clientList
+                arpCache = NetUtils.arp(binder.service.routing?.downstream)
+            } else owner = null
+            notifyDataSetChanged()  // recreate everything
+            binding.swipeRefresher.isRefreshing = false
+        }
+
+        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
+                ClientViewHolder(ListitemClientBinding.inflate(LayoutInflater.from(parent.context)))
+
+        override fun onBindViewHolder(holder: ClientViewHolder, position: Int) {
+            val device = when (position) {
+                0 -> owner
+                else -> clients.elementAt(position - 1)
+            }
+            holder.binding.device = device
+            holder.binding.ipAddress = when (position) {
+                0 -> binder?.service?.routing?.hostAddress?.hostAddress
+                else -> arpCache[device?.deviceAddress]
+            }
+            holder.binding.executePendingBindings()
+        }
+
+        override fun getItemCount() = if (owner == null) 0 else 1 + clients.size
+    }
+
+    private lateinit var binding: FragmentRepeaterBinding
+    private val data = Data()
+    private val adapter = ClientAdapter()
+    private var binder: RepeaterService.HotspotBinder? = null
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        binding = DataBindingUtil.inflate(inflater, R.layout.fragment_repeater, container, false)
+        binding.data = data
+        binding.clients.layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false)
+        val animator = DefaultItemAnimator()
+        animator.supportsChangeAnimations = false   // prevent fading-in/out when rebinding
+        binding.clients.itemAnimator = animator
+        binding.clients.adapter = adapter
+        binding.swipeRefresher.setOnRefreshListener { adapter.fetchClients() }
+        return binding.root
+    }
+
+    override fun onStart() {
+        super.onStart()
+        val context = context!!
+        context.bindService(Intent(context, RepeaterService::class.java), this, Context.BIND_AUTO_CREATE)
+    }
+
+    override fun onStop() {
+        onServiceDisconnected(null)
+        context!!.unbindService(this)
+        super.onStop()
+    }
+
+    override fun onServiceConnected(name: ComponentName?, service: IBinder?) {
+        val binder = service as RepeaterService.HotspotBinder
+        binder.data = data
+        this.binder = binder
+        data.onStatusChanged()
+        LocalBroadcastManager.getInstance(context!!)
+                .registerReceiver(data.statusListener, intentFilter(RepeaterService.STATUS_CHANGED))
+    }
+
+    override fun onServiceDisconnected(name: ComponentName?) {
+        binder?.data = null
+        binder = null
+        LocalBroadcastManager.getInstance(context!!).unregisterReceiver(data.statusListener)
+        data.onStatusChanged()
+    }
+}

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

@@ -0,0 +1,270 @@
+package be.mygod.vpnhotspot
+
+import android.app.PendingIntent
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.net.NetworkInfo
+import android.net.wifi.p2p.WifiP2pGroup
+import android.net.wifi.p2p.WifiP2pInfo
+import android.net.wifi.p2p.WifiP2pManager
+import android.os.Binder
+import android.os.Handler
+import android.os.Looper
+import android.support.v4.app.NotificationCompat
+import android.support.v4.content.ContextCompat
+import android.support.v4.content.LocalBroadcastManager
+import android.util.Log
+import android.widget.Toast
+import be.mygod.vpnhotspot.App.Companion.app
+import java.net.InetAddress
+import java.util.regex.Pattern
+
+class RepeaterService : Service(), WifiP2pManager.ChannelListener, VpnListener.Callback {
+    companion object {
+        const val CHANNEL = "hotspot"
+        const val STATUS_CHANGED = "be.mygod.vpnhotspot.RepeaterService.STATUS_CHANGED"
+        private const val TAG = "RepeaterService"
+
+        /**
+         * Matches the output of dumpsys wifip2p. This part is available since Android 4.2.
+         *
+         * Related sources:
+         *   https://android.googlesource.com/platform/frameworks/base/+/f0afe4144d09aa9b980cffd444911ab118fa9cbe%5E%21/wifi/java/android/net/wifi/p2p/WifiP2pService.java
+         *   https://android.googlesource.com/platform/frameworks/opt/net/wifi/+/a8d5e40/service/java/com/android/server/wifi/p2p/WifiP2pServiceImpl.java#639
+         *
+         *   https://android.googlesource.com/platform/frameworks/base.git/+/android-5.0.0_r1/core/java/android/net/NetworkInfo.java#433
+         *   https://android.googlesource.com/platform/frameworks/base.git/+/220871a/core/java/android/net/NetworkInfo.java#415
+         */
+        private val patternNetworkInfo = "^mNetworkInfo .* (isA|a)vailable: (true|false)".toPattern(Pattern.MULTILINE)
+    }
+
+    enum class Status {
+        IDLE, STARTING, ACTIVE
+    }
+
+    inner class HotspotBinder : Binder() {
+        val service get() = this@RepeaterService
+        var data: RepeaterFragment.Data? = null
+
+        fun shutdown() {
+            if (status == Status.ACTIVE) removeGroup()
+        }
+    }
+
+    private val handler = Handler()
+    private val p2pManager by lazy { getSystemService(Context.WIFI_P2P_SERVICE) as WifiP2pManager }
+    private var _channel: WifiP2pManager.Channel? = null
+    private val channel: WifiP2pManager.Channel get() {
+        if (_channel == null) onChannelDisconnected()
+        return _channel!!
+    }
+    lateinit var group: WifiP2pGroup
+        private set
+    private val binder = HotspotBinder()
+    private var receiverRegistered = false
+    private val receiver = broadcastReceiver { _, intent ->
+        when (intent.action) {
+            WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION ->
+                if (intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, 0) ==
+                        WifiP2pManager.WIFI_P2P_STATE_DISABLED) clean() // ignore P2P enabled
+            WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION -> {
+                onP2pConnectionChanged(intent.getParcelableExtra(WifiP2pManager.EXTRA_WIFI_P2P_INFO),
+                        intent.getParcelableExtra(WifiP2pManager.EXTRA_NETWORK_INFO),
+                        intent.getParcelableExtra(WifiP2pManager.EXTRA_WIFI_P2P_GROUP))
+            }
+        }
+    }
+    private val onVpnUnavailable = Runnable { startFailure("VPN unavailable") }
+
+    val ssid get() = if (status == Status.ACTIVE) group.networkName else null
+    val password get() = if (status == Status.ACTIVE) group.passphrase else null
+
+    private var upstream: String? = null
+    var routing: Routing? = null
+        private set
+
+    var status = Status.IDLE
+        private set(value) {
+            if (field == value) return
+            field = value
+            LocalBroadcastManager.getInstance(this).sendBroadcast(Intent(STATUS_CHANGED))
+        }
+
+    private fun formatReason(reason: Int) = when (reason) {
+        WifiP2pManager.ERROR -> "ERROR"
+        WifiP2pManager.P2P_UNSUPPORTED -> "P2P_UNSUPPORTED"
+        WifiP2pManager.BUSY -> "BUSY"
+        WifiP2pManager.NO_SERVICE_REQUESTS -> "NO_SERVICE_REQUESTS"
+        else -> "unknown reason: $reason"
+    }
+
+    override fun onBind(intent: Intent) = binder
+
+    override fun onChannelDisconnected() {
+        _channel = p2pManager.initialize(this, Looper.getMainLooper(), this)
+    }
+
+    /**
+     * startService 1st stop
+     */
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        if (status != Status.IDLE) return START_NOT_STICKY
+        status = Status.STARTING
+        handler.postDelayed(onVpnUnavailable, 4000)
+        VpnListener.registerCallback(this)
+        return START_NOT_STICKY
+    }
+    private fun startFailure(msg: String?, group: WifiP2pGroup? = null) {
+        Toast.makeText(this, msg, Toast.LENGTH_SHORT).show()
+        showNotification()
+        if (group != null) removeGroup() else clean()
+    }
+
+    /**
+     * startService 2nd stop, also called when VPN re-established
+     */
+    override fun onAvailable(ifname: String) {
+        handler.removeCallbacks(onVpnUnavailable)
+        when (status) {
+            Status.STARTING -> {
+                val matcher = patternNetworkInfo.matcher(loggerSu("dumpsys ${Context.WIFI_P2P_SERVICE}"))
+                when {
+                    !matcher.find() -> startFailure("Root unavailable")
+                    matcher.group(2) == "true" -> {
+                        unregisterReceiver()
+                        registerReceiver(receiver, intentFilter(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION,
+                                WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION))
+                        receiverRegistered = true
+                        upstream = ifname
+                        p2pManager.requestGroupInfo(channel, {
+                            when {
+                                it == null -> doStart()
+                                it.isGroupOwner -> doStart(it)
+                                else -> {
+                                    Log.i(TAG, "Removing old group ($it)")
+                                    p2pManager.removeGroup(channel, object : WifiP2pManager.ActionListener {
+                                        override fun onSuccess() = doStart()
+                                        override fun onFailure(reason: Int) {
+                                            Toast.makeText(this@RepeaterService,
+                                                    "Failed to remove old P2P group (${formatReason(reason)})",
+                                                    Toast.LENGTH_SHORT).show()
+                                        }
+                                    })
+                                }
+                            }
+                        })
+                    }
+                    else -> startFailure("Wi-Fi direct unavailable")
+                }
+            }
+            Status.ACTIVE -> {
+                val routing = routing
+                assert(!routing!!.started)
+                initRouting(ifname, routing.downstream, routing.hostAddress)
+            }
+            else -> throw RuntimeException("RepeaterService is in unexpected state when receiving onAvailable")
+        }
+    }
+    override fun onLost(ifname: String) {
+        routing?.stop()
+        upstream = null
+    }
+
+    private fun doStart() = p2pManager.createGroup(channel, object : WifiP2pManager.ActionListener {
+        override fun onFailure(reason: Int) = startFailure("Failed to create P2P group (${formatReason(reason)})")
+        override fun onSuccess() { }    // wait for WIFI_P2P_CONNECTION_CHANGED_ACTION to fire
+    })
+    private fun doStart(group: WifiP2pGroup) {
+        this.group = group
+        status = Status.ACTIVE
+        showNotification(group)
+    }
+
+    /**
+     * startService 3rd stop (if a group isn't already available), also called when connection changed
+     */
+    private fun onP2pConnectionChanged(info: WifiP2pInfo, net: NetworkInfo?, group: WifiP2pGroup) {
+        if (routing == null) onGroupCreated(info, group) else if (!group.isGroupOwner) {    // P2P shutdown
+            clean()
+            return
+        }
+        this.group = group
+        binder.data?.onGroupChanged()
+        showNotification(group)
+        Log.d(TAG, "P2P connection changed: $info\n$net\n$group")
+    }
+    private fun onGroupCreated(info: WifiP2pInfo, group: WifiP2pGroup) {
+        val owner = info.groupOwnerAddress
+        val downstream = group.`interface`
+        if (!info.groupFormed || !info.isGroupOwner || downstream == null || owner == null) return
+        receiverRegistered = true
+        try {
+            if (initRouting(upstream!!, downstream, owner)) doStart(group)
+            else startFailure("Something went wrong, please check logcat.", group)
+        } catch (e: Routing.InterfaceNotFoundException) {
+            startFailure(e.message, group)
+            return
+        }
+    }
+    private fun initRouting(upstream: String, downstream: String, owner: InetAddress): Boolean {
+        val routing = Routing(upstream, downstream, owner)
+                .ipForward()   // Wi-Fi direct doesn't enable ip_forward
+                .rule().forward().dnsRedirect(app.dns)
+        return if (routing.start()) {
+            this.routing = routing
+            true
+        } else {
+            routing.stop()
+            this.routing = null
+            false
+        }
+    }
+
+    private fun showNotification(group: WifiP2pGroup? = null) {
+        val builder = NotificationCompat.Builder(this, CHANNEL)
+                .setWhen(0)
+                .setColor(ContextCompat.getColor(this, R.color.colorPrimary))
+                .setContentTitle(group?.networkName ?: ssid ?: "Connecting...")
+                .setSmallIcon(R.drawable.ic_device_wifi_tethering)
+                .setContentIntent(PendingIntent.getActivity(this, 0,
+                        Intent(this, MainActivity::class.java), PendingIntent.FLAG_UPDATE_CURRENT))
+        if (group != null) builder.setContentText(resources.getQuantityString(R.plurals.notification_connected_devices,
+                group.clientList.size, group.clientList.size))
+        startForeground(1, builder.build())
+    }
+
+    private fun removeGroup() {
+        p2pManager.removeGroup(channel, object : WifiP2pManager.ActionListener {
+            override fun onSuccess() = clean()
+            override fun onFailure(reason: Int) {
+                if (reason == WifiP2pManager.BUSY) clean() else {   // assuming it's already gone
+                    Toast.makeText(this@RepeaterService, "Failed to remove P2P group (${formatReason(reason)})",
+                            Toast.LENGTH_SHORT).show()
+                    status = Status.ACTIVE
+                    LocalBroadcastManager.getInstance(this@RepeaterService).sendBroadcast(Intent(STATUS_CHANGED))
+                }
+            }
+        })
+    }
+    private fun unregisterReceiver() {
+        VpnListener.unregisterCallback(this)
+        if (receiverRegistered) {
+            unregisterReceiver(receiver)
+            receiverRegistered = false
+        }
+    }
+    private fun clean() {
+        unregisterReceiver()
+        if (routing?.stop() == false)
+            Toast.makeText(this, "Something went wrong, please check logcat.", Toast.LENGTH_SHORT).show()
+        routing = null
+        status = Status.IDLE
+        stopForeground(true)
+    }
+
+    override fun onDestroy() {
+        if (status != Status.IDLE) binder.shutdown()
+        super.onDestroy()
+    }
+}

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

@@ -7,7 +7,7 @@ import java.net.InetAddress
 import java.net.NetworkInterface
 import java.util.*
 
-class Routing(val upstream: String, val downstream: String, ownerAddress: InetAddress? = null) {
+class Routing(private val upstream: String, val downstream: String, ownerAddress: InetAddress? = null) {
     companion object {
         fun clean() = noisySu(
                 "iptables -t nat -F PREROUTING",
@@ -25,7 +25,8 @@ class Routing(val upstream: String, val downstream: String, ownerAddress: InetAd
             ?.singleOrNull { it is Inet4Address } ?: throw InterfaceNotFoundException()
     private val startScript = LinkedList<String>()
     private val stopScript = LinkedList<String>()
-    private var started = false
+    var started = false
+        private set
 
     fun ipForward(): Routing {
         startScript.add("echo 1 >/proc/sys/net/ipv4/ip_forward")

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

@@ -1,14 +0,0 @@
-package be.mygod.vpnhotspot
-
-import android.databinding.DataBindingUtil
-import android.os.Bundle
-import android.support.v7.app.AppCompatActivity
-import be.mygod.vpnhotspot.databinding.ActivitySettingsBinding
-
-class SettingsActivity : AppCompatActivity() {
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        DataBindingUtil.setContentView<ActivitySettingsBinding>(this, R.layout.activity_settings)
-                .toolbar.setNavigationOnClickListener({ navigateUp() })
-    }
-}

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

@@ -1,51 +1,12 @@
 package be.mygod.vpnhotspot
 
-import android.content.Intent
-import android.net.Uri
 import android.os.Bundle
-import android.support.customtabs.CustomTabsIntent
+import android.support.v4.app.Fragment
-import android.support.v4.content.ContextCompat
+import android.view.LayoutInflater
-import android.support.v7.preference.Preference
+import android.view.View
-import be.mygod.vpnhotspot.App.Companion.app
+import android.view.ViewGroup
-import be.mygod.vpnhotspot.preference.AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat
-import com.takisoft.fix.support.v7.preference.PreferenceFragmentCompatDividers
-import java.net.NetworkInterface
 
-class SettingsFragment : PreferenceFragmentCompatDividers() {
+class SettingsFragment : Fragment() {
-    private val customTabsIntent by lazy {
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? =
-        CustomTabsIntent.Builder().setToolbarColor(ContextCompat.getColor(activity!!, R.color.colorPrimary)).build()
+            inflater.inflate(R.layout.fragment_settings, container, false)
-    }
-
-    override fun onCreatePreferencesFix(savedInstanceState: Bundle?, rootKey: String?) {
-        addPreferencesFromResource(R.xml.pref_settings)
-        findPreference("misc.logcat").setOnPreferenceClickListener {
-            val intent = Intent(Intent.ACTION_SEND)
-                    .setType("text/plain")
-                    .putExtra(Intent.EXTRA_TEXT, Runtime.getRuntime().exec(arrayOf("logcat", "-d"))
-                            .inputStream.bufferedReader().use { it.readText() })
-            startActivity(Intent.createChooser(intent, getString(R.string.abc_shareactionprovider_share_with)))
-            true
-        }
-        findPreference("misc.source").setOnPreferenceClickListener {
-            customTabsIntent.launchUrl(activity, Uri.parse("https://github.com/Mygod/VPNHotspot"))
-            true
-        }
-        findPreference("misc.donate").setOnPreferenceClickListener {
-            customTabsIntent.launchUrl(activity, Uri.parse("https://mygod.be/donate/"))
-            true
-        }
-    }
-
-    override fun onDisplayPreferenceDialog(preference: Preference) = when (preference.key) {
-        HotspotService.KEY_UPSTREAM -> displayPreferenceDialog(
-                AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat(), HotspotService.KEY_UPSTREAM,
-                Bundle().put(AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat.KEY_SUGGESTIONS,
-                        NetworkInterface.getNetworkInterfaces().asSequence()
-                                .filter { it.isUp && !it.isLoopback && it.interfaceAddresses.isNotEmpty() }
-                                .map { it.name }.sorted().toList().toTypedArray()))
-        HotspotService.KEY_WIFI -> displayPreferenceDialog(
-                AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat(), HotspotService.KEY_WIFI, Bundle()
-                    .put(AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat.KEY_SUGGESTIONS, app.wifiInterfaces))
-        else -> super.onDisplayPreferenceDialog(preference)
-    }
 }

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

@@ -0,0 +1,38 @@
+package be.mygod.vpnhotspot
+
+import android.content.Intent
+import android.net.Uri
+import android.os.Bundle
+import android.support.customtabs.CustomTabsIntent
+import android.support.v4.content.ContextCompat
+import com.takisoft.fix.support.v7.preference.PreferenceFragmentCompatDividers
+
+class SettingsPreferenceFragment : PreferenceFragmentCompatDividers() {
+    private val customTabsIntent by lazy {
+        CustomTabsIntent.Builder().setToolbarColor(ContextCompat.getColor(activity!!, R.color.colorPrimary)).build()
+    }
+
+    override fun onCreatePreferencesFix(savedInstanceState: Bundle?, rootKey: String?) {
+        addPreferencesFromResource(R.xml.pref_settings)
+        findPreference("service.clean").setOnPreferenceClickListener {
+            Routing.clean()
+            true
+        }
+        findPreference("misc.logcat").setOnPreferenceClickListener {
+            val intent = Intent(Intent.ACTION_SEND)
+                    .setType("text/plain")
+                    .putExtra(Intent.EXTRA_TEXT, Runtime.getRuntime().exec(arrayOf("logcat", "-d"))
+                            .inputStream.bufferedReader().use { it.readText() })
+            startActivity(Intent.createChooser(intent, getString(R.string.abc_shareactionprovider_share_with)))
+            true
+        }
+        findPreference("misc.source").setOnPreferenceClickListener {
+            customTabsIntent.launchUrl(activity, Uri.parse("https://github.com/Mygod/VPNHotspot"))
+            true
+        }
+        findPreference("misc.donate").setOnPreferenceClickListener {
+            customTabsIntent.launchUrl(activity, Uri.parse("https://mygod.be/donate/"))
+            true
+        }
+    }
+}

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

@@ -0,0 +1,141 @@
+package be.mygod.vpnhotspot
+
+import android.content.Intent
+import android.content.res.Resources
+import android.databinding.BaseObservable
+import android.databinding.DataBindingUtil
+import android.os.Bundle
+import android.support.v4.app.Fragment
+import android.support.v4.content.LocalBroadcastManager
+import android.support.v7.util.SortedList
+import android.support.v7.widget.DefaultItemAnimator
+import android.support.v7.widget.LinearLayoutManager
+import android.support.v7.widget.RecyclerView
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import be.mygod.vpnhotspot.App.Companion.app
+import be.mygod.vpnhotspot.NetUtils.tetheredIfaces
+import be.mygod.vpnhotspot.databinding.FragmentTetheringBinding
+import be.mygod.vpnhotspot.databinding.ListitemInterfaceBinding
+
+class TetheringFragment : Fragment() {
+    companion object {
+        /**
+         * Source: https://android.googlesource.com/platform/frameworks/base/+/61fa313/core/res/res/values/config.xml#328
+         */
+        private val usbRegexes = app.resources.getStringArray(Resources.getSystem()
+                .getIdentifier("config_tether_usb_regexs", "array", "android"))
+                .map { it.toPattern() }
+        private val wifiRegexes = app.resources.getStringArray(Resources.getSystem()
+                .getIdentifier("config_tether_wifi_regexs", "array", "android"))
+                .map { it.toPattern() }
+        private val wimaxRegexes = app.resources.getStringArray(Resources.getSystem()
+                .getIdentifier("config_tether_wimax_regexs", "array", "android"))
+                .map { it.toPattern() }
+        private val bluetoothRegexes = app.resources.getStringArray(Resources.getSystem()
+                .getIdentifier("config_tether_bluetooth_regexs", "array", "android"))
+                .map { it.toPattern() }
+    }
+
+    private abstract class BaseSorter<T> : SortedList.Callback<T>() {
+        override fun onInserted(position: Int, count: Int) { }
+        override fun areContentsTheSame(oldItem: T?, newItem: T?): Boolean = oldItem == newItem
+        override fun onMoved(fromPosition: Int, toPosition: Int) { }
+        override fun onChanged(position: Int, count: Int) { }
+        override fun onRemoved(position: Int, count: Int) { }
+        override fun areItemsTheSame(item1: T?, item2: T?): Boolean = item1 == item2
+        override fun compare(o1: T?, o2: T?): Int =
+                if (o1 == null) if (o2 == null) 0 else 1 else if (o2 == null) -1 else compareNonNull(o1, o2)
+        abstract fun compareNonNull(o1: T, o2: T): Int
+    }
+    private open class DefaultSorter<T : Comparable<T>> : BaseSorter<T>() {
+        override fun compareNonNull(o1: T, o2: T): Int = o1.compareTo(o2)
+    }
+    private object StringSorter : DefaultSorter<String>()
+
+    class Data(val iface: String) : BaseObservable() {
+        val icon: Int get() = when {
+            usbRegexes.any { it.matcher(iface).matches() } -> R.drawable.ic_device_usb
+            wifiRegexes.any { it.matcher(iface).matches() } -> R.drawable.ic_device_network_wifi
+            wimaxRegexes.any { it.matcher(iface).matches() } -> R.drawable.ic_device_network_wifi
+            bluetoothRegexes.any { it.matcher(iface).matches() } -> R.drawable.ic_device_bluetooth
+            else -> R.drawable.ic_device_wifi_tethering
+        }
+        var active = TetheringService.active?.contains(iface) == true
+    }
+
+    class InterfaceViewHolder(val binding: ListitemInterfaceBinding) : RecyclerView.ViewHolder(binding.root),
+            View.OnClickListener {
+        init {
+            itemView.setOnClickListener(this)
+        }
+
+        override fun onClick(view: View) {
+            val context = itemView.context
+            val data = binding.data!!
+            context.startService(Intent(context, TetheringService::class.java).putExtra(if (data.active)
+                TetheringService.EXTRA_REMOVE_INTERFACE else TetheringService.EXTRA_ADD_INTERFACE, data.iface))
+            data.active = !data.active
+        }
+    }
+    inner class InterfaceAdapter : RecyclerView.Adapter<InterfaceViewHolder>() {
+        private val tethered = SortedList(String::class.java, StringSorter)
+
+        fun update(data: Set<String> = VpnListener.connectivityManager.tetheredIfaces.toSet()) {
+            tethered.clear()
+            tethered.addAll(data)
+            notifyDataSetChanged()
+        }
+
+        override fun getItemCount() = tethered.size()
+        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) = InterfaceViewHolder(
+                ListitemInterfaceBinding.inflate(LayoutInflater.from(parent.context), parent, false))
+        override fun onBindViewHolder(holder: InterfaceViewHolder, position: Int) {
+            holder.binding.data = Data(tethered[position])
+        }
+    }
+
+    private val adapter = InterfaceAdapter()
+    private val receiver = broadcastReceiver { _, intent ->
+        when (intent.action) {
+            TetheringService.ACTION_ACTIVE_INTERFACES_CHANGED -> adapter.notifyDataSetChanged()
+            NetUtils.ACTION_TETHER_STATE_CHANGED ->
+                adapter.update(intent.extras.getStringArrayList(NetUtils.EXTRA_ACTIVE_TETHER).toSet())
+        }
+    }
+    private var receiverRegistered = false
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        val binding = DataBindingUtil.inflate<FragmentTetheringBinding>(inflater, R.layout.fragment_tethering,
+                container, false)
+        binding.interfaces.layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false)
+        val animator = DefaultItemAnimator()
+        animator.supportsChangeAnimations = false   // prevent fading-in/out when rebinding
+        binding.interfaces.itemAnimator = animator
+        binding.interfaces.adapter = adapter
+        return binding.root
+    }
+
+    override fun onStart() {
+        super.onStart()
+        if (!receiverRegistered) {
+            adapter.update()
+            val context = context!!
+            context.registerReceiver(receiver, intentFilter(NetUtils.ACTION_TETHER_STATE_CHANGED))
+            LocalBroadcastManager.getInstance(context)
+                    .registerReceiver(receiver, intentFilter(TetheringService.ACTION_ACTIVE_INTERFACES_CHANGED))
+            receiverRegistered = true
+        }
+    }
+
+    override fun onStop() {
+        if (receiverRegistered) {
+            val context = context!!
+            context.unregisterReceiver(receiver)
+            LocalBroadcastManager.getInstance(context).unregisterReceiver(receiver)
+            receiverRegistered = false
+        }
+        super.onStop()
+    }
+}

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

@@ -0,0 +1,87 @@
+package be.mygod.vpnhotspot
+
+import android.app.Service
+import android.content.Intent
+import android.support.v4.content.LocalBroadcastManager
+import be.mygod.vpnhotspot.App.Companion.app
+import be.mygod.vpnhotspot.NetUtils.tetheredIfaces
+
+class TetheringService : Service(), VpnListener.Callback {
+    companion object {
+        const val ACTION_ACTIVE_INTERFACES_CHANGED = "be.mygod.vpnhotspot.TetheringService.ACTIVE_INTERFACES_CHANGED"
+        const val EXTRA_ADD_INTERFACE = "interface.add"
+        const val EXTRA_REMOVE_INTERFACE = "interface.remove"
+        private const val KEY_ACTIVE = "persist.service.tether.active"
+
+        var active: Set<String>?
+            get() = app.pref.getStringSet(KEY_ACTIVE, null)
+            private set(value) {
+                app.pref.edit().putStringSet(KEY_ACTIVE, value).apply()
+                LocalBroadcastManager.getInstance(app).sendBroadcast(Intent(ACTION_ACTIVE_INTERFACES_CHANGED))
+            }
+    }
+
+    private val routings = HashMap<String, Routing?>()
+    private var upstream: String? = null
+    private var receiverRegistered = false
+    private val receiver = broadcastReceiver { _, intent ->
+        val remove = routings - intent.extras.getStringArrayList(NetUtils.EXTRA_ACTIVE_TETHER).toSet()
+        if (remove.isEmpty()) return@broadcastReceiver
+        for ((iface, routing) in remove) {
+            routing?.stop()
+            routings.remove(iface)
+        }
+        val upstream = upstream
+        if (upstream == null) onLost("") else onAvailable(upstream)
+        active = routings.keys
+        if (routings.isEmpty()) terminate()
+    }
+
+    override fun onBind(intent: Intent?) = null
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        if (intent != null) {   // otw service is recreated after being killed
+            var iface = intent.getStringExtra(EXTRA_ADD_INTERFACE)
+            if (iface != null && VpnListener.connectivityManager.tetheredIfaces.contains(iface))
+                routings.put(iface, null)
+            iface = intent.getStringExtra(EXTRA_REMOVE_INTERFACE)
+            if (iface != null) routings.remove(iface)?.stop()
+            active = routings.keys
+        } else active?.forEach { routings.put(it, null) }
+        if (routings.isEmpty()) terminate() else {
+            if (!receiverRegistered) {
+                registerReceiver(receiver, intentFilter(NetUtils.ACTION_TETHER_STATE_CHANGED))
+                VpnListener.registerCallback(this)
+                receiverRegistered = true
+            }
+        }
+        return START_STICKY
+    }
+
+    override fun onAvailable(ifname: String) {
+        assert(upstream == null || upstream == ifname)
+        upstream = ifname
+        for ((downstream, value) in routings) if (value == null) {
+            val routing = Routing(ifname, downstream).rule().forward().dnsRedirect(app.dns)
+            if (routing.start()) routings[downstream] = routing else routing.stop()
+        }
+    }
+
+    override fun onLost(ifname: String) {
+        assert(upstream == null || upstream == ifname)
+        upstream = null
+        for ((iface, routing) in routings) {
+            routing?.stop()
+            routings[iface] = null
+        }
+    }
+
+    private fun terminate() {
+        if (receiverRegistered) {
+            unregisterReceiver(receiver)
+            VpnListener.unregisterCallback(this)
+            receiverRegistered = false
+        }
+        stopSelf()
+    }
+}

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

@@ -4,9 +4,6 @@ import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
 import android.content.IntentFilter
-import android.os.Bundle
-import android.support.v4.app.TaskStackBuilder
-import android.support.v7.app.AppCompatActivity
 import android.util.Log
 import java.io.InputStream
 
@@ -24,18 +21,6 @@ fun intentFilter(vararg actions: String): IntentFilter {
     return result
 }
 
-fun AppCompatActivity.navigateUp() {
-    val intent = parentActivityIntent
-    if (shouldUpRecreateTask(intent))
-        TaskStackBuilder.create(this).addNextIntentWithParentStack(intent).startActivities()
-    else navigateUpTo(intent)
-}
-
-fun Bundle.put(key: String, map: Array<String>): Bundle {
-    putStringArray(key, map)
-    return this
-}
-
 private const val NOISYSU_TAG = "NoisySU"
 private const val NOISYSU_SUFFIX = "SUCCESS\n"
 fun loggerSuStream(command: String): InputStream {

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

@@ -0,0 +1,58 @@
+package be.mygod.vpnhotspot
+
+import android.content.Context
+import android.net.ConnectivityManager
+import android.net.Network
+import android.net.NetworkCapabilities
+import android.net.NetworkRequest
+import be.mygod.vpnhotspot.App.Companion.app
+
+object VpnListener : ConnectivityManager.NetworkCallback() {
+    interface Callback {
+        fun onAvailable(ifname: String)
+        fun onLost(ifname: String)
+    }
+
+    private const val TAG = "VpnListener"
+
+    val connectivityManager = app.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+    private val request by lazy {
+        NetworkRequest.Builder()
+                .addTransportType(NetworkCapabilities.TRANSPORT_VPN)
+                .removeCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)
+                .build()
+    }
+    private val callbacks = HashSet<Callback>()
+    private var registered = false
+
+    /**
+     * Obtaining ifname in onLost doesn't work so we need to cache it in onAvailable.
+     */
+    private val available = HashMap<Network, String>()
+    override fun onAvailable(network: Network) {
+        val ifname = connectivityManager.getLinkProperties(network)?.interfaceName ?: return
+        available.put(network, ifname)
+        debugLog(TAG, "onAvailable: $ifname")
+        callbacks.forEach { it.onAvailable(ifname) }
+    }
+
+    override fun onLost(network: Network) {
+        val ifname = available.remove(network) ?: return
+        debugLog(TAG, "onLost: $ifname")
+        callbacks.forEach { it.onLost(ifname) }
+    }
+
+    fun registerCallback(callback: Callback) {
+        if (!callbacks.add(callback)) return
+        if (registered) available.forEach { callback.onAvailable(it.value) } else {
+            connectivityManager.registerNetworkCallback(request, this)
+            registered = false
+        }
+    }
+    fun unregisterCallback(callback: Callback) {
+        if (!callbacks.remove(callback) || callbacks.isNotEmpty() || !registered) return
+        connectivityManager.unregisterNetworkCallback(this)
+        registered = false
+        available.clear()
+    }
+}

mobile/src/main/java/be/mygod/vpnhotspot/preference/AlwaysAutoCompleteEditText.kt

@@ -1,25 +0,0 @@
-package be.mygod.vpnhotspot.preference
-
-import android.content.Context
-import android.graphics.Rect
-import android.support.v7.widget.AppCompatAutoCompleteTextView
-import android.util.AttributeSet
-import android.view.View
-import be.mygod.vpnhotspot.R
-
-/**
- * Based on: https://gist.github.com/furycomptuers/4961368
- */
-class AlwaysAutoCompleteEditText @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null,
-                                                           defStyleAttr: Int = R.attr.autoCompleteTextViewStyle) :
-        AppCompatAutoCompleteTextView(context, attrs, defStyleAttr) {
-    override fun enoughToFilter() = true
-
-    override fun onFocusChanged(focused: Boolean, direction: Int, previouslyFocusedRect: Rect?) {
-        super.onFocusChanged(focused, direction, previouslyFocusedRect)
-        if (focused && windowVisibility != View.GONE) {
-            performFiltering(text, 0)
-            showDropDown()
-        }
-    }
-}

mobile/src/main/java/be/mygod/vpnhotspot/preference/AlwaysAutoCompleteEditTextPreference.kt

@@ -1,23 +0,0 @@
-package be.mygod.vpnhotspot.preference
-
-import android.content.Context
-import android.text.TextUtils
-import android.util.AttributeSet
-import be.mygod.vpnhotspot.R
-import com.takisoft.fix.support.v7.preference.AutoSummaryEditTextPreference
-
-open class AlwaysAutoCompleteEditTextPreference @JvmOverloads constructor(
-        context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = R.attr.editTextPreferenceStyle,
-        defStyleRes: Int = 0) : AutoSummaryEditTextPreference(context, attrs, defStyleAttr, defStyleRes) {
-    val editText = AlwaysAutoCompleteEditText(context, attrs)
-
-    init {
-        editText.id = android.R.id.edit
-    }
-
-    override fun setText(text: String) {
-        val oldText = getText()
-        super.setText(text)
-        if (!TextUtils.equals(text, oldText)) notifyChanged()
-    }
-}

mobile/src/main/java/be/mygod/vpnhotspot/preference/AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat.kt

@@ -1,59 +0,0 @@
-package be.mygod.vpnhotspot.preference
-
-import android.support.v7.preference.PreferenceDialogFragmentCompat
-import android.support.v7.widget.AppCompatAutoCompleteTextView
-import android.view.View
-import android.view.ViewGroup
-import android.widget.ArrayAdapter
-import android.widget.EditText
-
-open class AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat : PreferenceDialogFragmentCompat() {
-    companion object {
-        const val KEY_SUGGESTIONS = "suggestions"
-    }
-
-    private lateinit var editText: AppCompatAutoCompleteTextView
-    private val editTextPreference get() = this.preference as AlwaysAutoCompleteEditTextPreference
-
-    override fun onBindDialogView(view: View) {
-        super.onBindDialogView(view)
-
-        editText = editTextPreference.editText
-        editText.setText(this.editTextPreference.text)
-
-        val text = editText.text
-        if (text != null) editText.setSelection(text.length, text.length)
-
-        val suggestions = arguments?.getStringArray(KEY_SUGGESTIONS)
-        if (suggestions != null)
-            editText.setAdapter(ArrayAdapter(view.context, android.R.layout.select_dialog_item, suggestions))
-
-        val oldParent = editText.parent as? ViewGroup?
-        if (oldParent !== view) {
-            oldParent?.removeView(editText)
-            onAddEditTextToDialogView(view, editText)
-        }
-    }
-
-    override fun needInputMethod(): Boolean = true
-
-    protected fun onAddEditTextToDialogView(dialogView: View, editText: EditText) {
-        val oldEditText = dialogView.findViewById<View>(android.R.id.edit)
-        if (oldEditText != null) {
-            val container = oldEditText.parent as? ViewGroup?
-            if (container != null) {
-                container.removeView(oldEditText)
-                container.addView(editText, ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT)
-            }
-        }
-    }
-
-    override fun onDialogClosed(positiveResult: Boolean) {
-        if (positiveResult) {
-            val value = this.editText.text.toString()
-            if (this.editTextPreference.callChangeListener(value)) {
-                this.editTextPreference.text = value
-            }
-        }
-    }
-}

mobile/src/main/res/drawable/ic_device_bluetooth.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M17.71,7.71L12,2h-1v7.59L6.41,5 5,6.41 10.59,12 5,17.59 6.41,19 11,14.41L11,22h1l5.71,-5.71 -4.3,-4.29 4.3,-4.29zM13,5.83l1.88,1.88L13,9.59L13,5.83zM14.88,16.29L13,18.17v-3.76l1.88,1.88z"/>
+</vector>

mobile/src/main/res/drawable/ic_device_network_wifi.xml

@@ -0,0 +1,13 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportWidth="24.0"
+        android:viewportHeight="24.0">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M12.01,21.49L23.64,7c-0.45,-0.34 -4.93,-4 -11.64,-4C5.28,3 0.81,6.66 0.36,7l11.63,14.49 0.01,0.01 0.01,-0.01z"
+        android:fillAlpha=".3"/>
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M3.53,10.95l8.46,10.54 0.01,0.01 0.01,-0.01 8.46,-10.54C20.04,10.62 16.81,8 12,8c-4.81,0 -8.04,2.62 -8.47,2.95z"/>
+</vector>

mobile/src/main/res/drawable/ic_device_usb.xml

@@ -0,0 +1,5 @@
+<vector android:autoMirrored="true" android:height="24dp"
+    android:viewportHeight="24.0" android:viewportWidth="24.0"
+    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="#FF000000" android:pathData="M15,7v4h1v2h-3V5h2l-3,-4 -3,4h2v8H8v-2.07c0.7,-0.37 1.2,-1.08 1.2,-1.93 0,-1.21 -0.99,-2.2 -2.2,-2.2 -1.21,0 -2.2,0.99 -2.2,2.2 0,0.85 0.5,1.56 1.2,1.93V13c0,1.11 0.89,2 2,2h3v3.05c-0.71,0.37 -1.2,1.1 -1.2,1.95 0,1.22 0.99,2.2 2.2,2.2 1.21,0 2.2,-0.98 2.2,-2.2 0,-0.85 -0.49,-1.58 -1.2,-1.95V15h3c1.11,0 2,-0.89 2,-2v-2h1V7h-4z"/>
+</vector>

mobile/src/main/res/drawable/ic_device_wifi_tethering.xml

@@ -2,7 +2,8 @@
         android:width="24dp"
         android:height="24dp"
         android:viewportWidth="24.0"
-        android:viewportHeight="24.0">
+        android:viewportHeight="24.0"
+        android:tint="?attr/colorControlNormal">
     <path
         android:fillColor="#FFFFFFFF"
         android:pathData="M12,11c-1.1,0 -2,0.9 -2,2s0.9,2 2,2 2,-0.9 2,-2 -0.9,-2 -2,-2zM18,13c0,-3.31 -2.69,-6 -6,-6s-6,2.69 -6,6c0,2.22 1.21,4.15 3,5.19l1,-1.74c-1.19,-0.7 -2,-1.97 -2,-3.45 0,-2.21 1.79,-4 4,-4s4,1.79 4,4c0,1.48 -0.81,2.75 -2,3.45l1,1.74c1.79,-1.04 3,-2.97 3,-5.19zM12,3C6.48,3 2,7.48 2,13c0,3.7 2.01,6.92 4.99,8.65l1,-1.73C5.61,18.53 4,15.96 4,13c0,-4.42 3.58,-8 8,-8s8,3.58 8,8c0,2.96 -1.61,5.53 -4,6.92l1,1.73c2.99,-1.73 5,-4.95 5,-8.65 0,-5.52 -4.48,-10 -10,-10z"/>

mobile/src/main/res/layout/activity_main.xml

@@ -3,111 +3,34 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools">
-    <data>
+    <android.support.constraint.ConstraintLayout
-        <variable
-            name="data"
-            type="be.mygod.vpnhotspot.MainActivity.Data"/>
-    </data>
-    <LinearLayout
-        android:orientation="vertical"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent">
-        <android.support.v7.widget.Toolbar
-            android:layout_height="?attr/actionBarSize"
-            android:layout_width="match_parent"
-            android:background="?attr/colorPrimary"
-            android:elevation="4dp"
-            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
-            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
-            android:id="@+id/toolbar">
-
-            <Switch
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-                android:enabled="@{data.switchEnabled}"
+        tools:context="be.mygod.vpnhotspot.MainActivity">
-                android:checked="@{data.serviceStarted}"
-                android:onCheckedChanged="@{(_, checked) -> data.setServiceStarted(checked)}"
-                android:text="@string/app_name"
-                android:textAppearance="@style/TextAppearance.Widget.AppCompat.Toolbar.Title"/>
-        </android.support.v7.widget.Toolbar>
 
-        <GridLayout
+        <FrameLayout
-            android:layout_width="match_parent"
+            android:id="@+id/fragmentHolder"
-            android:layout_height="wrap_content"
+            android:layout_width="0dp"
-            android:paddingBottom="8dp"
-            android:paddingEnd="16dp"
-            android:paddingStart="16dp"
-            android:paddingTop="8dp">
-
-            <TextView
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:text="Network name"
-                android:textAppearance="@style/TextAppearance.AppCompat.Subhead"/>
-
-            <Space
-                android:layout_width="8dp"
             android:layout_height="0dp"
-                android:layout_column="1"
+            android:layout_marginEnd="0dp"
-                android:layout_row="0"/>
+            android:layout_marginStart="0dp"
+            app:layout_constraintBottom_toTopOf="@+id/navigation"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="parent"/>
 
-            <TextView
+        <android.support.design.widget.BottomNavigationView
-                android:layout_width="wrap_content"
+            android:id="@+id/navigation"
+            android:layout_width="0dp"
             android:layout_height="wrap_content"
-                android:layout_column="2"
+            android:layout_marginEnd="0dp"
-                android:layout_row="0"
+            android:layout_marginStart="0dp"
-                android:text="@{data.ssid}"
+            android:background="?android:attr/windowBackground"
-                android:textIsSelectable="true"
+            app:layout_constraintBottom_toBottomOf="parent"
-                tools:text="DIRECT-rAnd0m"/>
+            app:layout_constraintLeft_toLeftOf="parent"
+            app:layout_constraintRight_toRightOf="parent"
+            app:menu="@menu/navigation"/>
 
-            <TextView
+    </android.support.constraint.ConstraintLayout>
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:layout_column="0"
-                android:layout_row="1"
-                android:text="Password"
-                android:textAppearance="@style/TextAppearance.AppCompat.Subhead"/>
 
-            <TextView
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:layout_column="2"
-                android:layout_row="1"
-                android:text="@{data.password}"
-                android:textIsSelectable="true"
-                tools:text="p4ssW0rd"/>
-        </GridLayout>
-
-        <TextView
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:paddingStart="16dp"
-            android:paddingEnd="16dp"
-            android:text="Connected devices"
-            android:textAppearance="@style/TextAppearance.AppCompat.Medium"/>
-
-        <View
-            android:layout_width="match_parent"
-            android:layout_height="1dp"
-            android:background="#000"
-            android:backgroundTint="?android:attr/textColorSecondary"/>
-
-        <android.support.v4.widget.SwipeRefreshLayout
-            android:id="@+id/swipeRefresher"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent">
-
-            <android.support.v7.widget.RecyclerView
-                android:id="@+id/clients"
-                android:layout_width="match_parent"
-                android:layout_height="match_parent"
-                android:paddingBottom="8dp"
-                android:paddingEnd="16dp"
-                android:paddingStart="16dp"
-                android:paddingTop="8dp"
-                android:clipToPadding="false"
-                android:scrollbars="vertical"
-                tools:listitem="@layout/listitem_client"/>
-        </android.support.v4.widget.SwipeRefreshLayout>
-    </LinearLayout>
 </layout>

mobile/src/main/res/layout/fragment_repeater.xml

@@ -0,0 +1,115 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools">
+    <data>
+        <variable
+            name="data"
+            type="be.mygod.vpnhotspot.RepeaterFragment.Data"/>
+    </data>
+    <LinearLayout
+        android:orientation="vertical"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+        <android.support.v7.widget.Toolbar
+            android:layout_height="?attr/actionBarSize"
+            android:layout_width="match_parent"
+            android:background="?attr/colorPrimary"
+            android:elevation="4dp"
+            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
+            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
+            android:id="@+id/toolbar">
+
+            <Switch
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:enabled="@{data.switchEnabled}"
+                android:checked="@{data.serviceStarted}"
+                android:onCheckedChanged="@{(_, checked) -> data.setServiceStarted(checked)}"
+                android:paddingEnd="8dp"
+                android:text="@string/app_name"
+                android:textAppearance="@style/TextAppearance.Widget.AppCompat.Toolbar.Title"
+                tools:ignore="RtlSymmetry"/>
+        </android.support.v7.widget.Toolbar>
+
+        <GridLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingBottom="8dp"
+            android:paddingEnd="16dp"
+            android:paddingStart="16dp"
+            android:paddingTop="8dp">
+
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="Network name"
+                android:textAppearance="@style/TextAppearance.AppCompat.Subhead"/>
+
+            <Space
+                android:layout_width="8dp"
+                android:layout_height="0dp"
+                android:layout_column="1"
+                android:layout_row="0"/>
+
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_column="2"
+                android:layout_row="0"
+                android:text="@{data.ssid}"
+                android:textIsSelectable="true"
+                tools:text="DIRECT-rAnd0m"/>
+
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_column="0"
+                android:layout_row="1"
+                android:text="Password"
+                android:textAppearance="@style/TextAppearance.AppCompat.Subhead"/>
+
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_column="2"
+                android:layout_row="1"
+                android:text="@{data.password}"
+                android:textIsSelectable="true"
+                tools:text="p4ssW0rd"/>
+        </GridLayout>
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingStart="16dp"
+            android:paddingEnd="16dp"
+            android:text="Connected devices"
+            android:textAppearance="@style/TextAppearance.AppCompat.Medium"/>
+
+        <View
+            android:layout_width="match_parent"
+            android:layout_height="1dp"
+            android:background="#000"
+            android:backgroundTint="?android:attr/textColorSecondary"/>
+
+        <android.support.v4.widget.SwipeRefreshLayout
+            android:id="@+id/swipeRefresher"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent">
+
+            <android.support.v7.widget.RecyclerView
+                android:id="@+id/clients"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:paddingBottom="8dp"
+                android:paddingEnd="16dp"
+                android:paddingStart="16dp"
+                android:paddingTop="8dp"
+                android:clipToPadding="false"
+                android:scrollbars="vertical"
+                tools:listitem="@layout/listitem_client"/>
+        </android.support.v4.widget.SwipeRefreshLayout>
+    </LinearLayout>
+</layout>

mobile/src/main/res/layout/fragment_settings.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:orientation="vertical"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+    <android.support.v7.widget.Toolbar
+        android:layout_height="?attr/actionBarSize"
+        android:layout_width="match_parent"
+        android:background="?attr/colorPrimary"
+        android:elevation="4dp"
+        app:title="@string/app_name"
+        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
+        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
+        android:id="@+id/toolbar"/>
+    <fragment
+        class="be.mygod.vpnhotspot.SettingsPreferenceFragment"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1"
+        android:id="@+id/preference"/>
+</LinearLayout>

mobile/src/main/res/layout/fragment_tethering.xml

@@ -1,7 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <layout
     xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:app="http://schemas.android.com/apk/res-auto">
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools">
     <LinearLayout
         android:orientation="vertical"
         android:layout_width="match_parent"
@@ -11,16 +12,17 @@
             android:layout_width="match_parent"
             android:background="?attr/colorPrimary"
             android:elevation="4dp"
-            app:title="@string/title_activity_settings"
+            app:title="@string/app_name"
-            app:navigationIcon="?attr/homeAsUpIndicator"
             android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
             app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
             android:id="@+id/toolbar"/>
-        <fragment
+        <android.support.v7.widget.RecyclerView
-            class="be.mygod.vpnhotspot.SettingsFragment"
+            android:id="@+id/interfaces"
             android:layout_width="match_parent"
             android:layout_height="0dp"
             android:layout_weight="1"
-            android:id="@+id/preference"/>
+            android:clipToPadding="false"
+            android:scrollbars="vertical"
+            tools:listitem="@layout/listitem_interface"/>
     </LinearLayout>
 </layout>

mobile/src/main/res/layout/listitem_interface.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
+    <data>
+        <variable
+            name="data"
+            type="be.mygod.vpnhotspot.TetheringFragment.Data"/>
+    </data>
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:focusable="true"
+        android:background="?android:attr/selectableItemBackground"
+        android:paddingBottom="8dp"
+        android:paddingEnd="16dp"
+        android:paddingStart="16dp"
+        android:paddingTop="8dp">
+
+        <ImageView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:src="@{data.icon}"
+            tools:src="@drawable/ic_device_network_wifi"/>
+
+        <Space
+            android:layout_width="8dp"
+            android:layout_height="0dp"/>
+
+        <Switch
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:clickable="false"
+            android:ellipsize="end"
+            android:focusable="false"
+            android:focusableInTouchMode="false"
+            android:gravity="center_vertical"
+            android:text="@{data.iface}"
+            android:checked="@{data.active}"
+            tools:text="wlan0"/>
+
+    </LinearLayout>
+</layout>

mobile/src/main/res/menu/main.xml

@@ -1,14 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<menu xmlns:android="http://schemas.android.com/apk/res/android"
-      xmlns:app="http://schemas.android.com/apk/res-auto">
-    <item
-        android:id="@+id/reapply"
-        android:icon="@drawable/ic_navigation_refresh"
-        android:title="Reapply routing rules"
-        app:showAsAction="always"/>
-    <item
-        android:id="@+id/settings"
-        android:icon="@drawable/ic_action_settings"
-        android:title="@string/title_activity_settings"
-        app:showAsAction="always"/>
-</menu>

mobile/src/main/res/menu/navigation.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <item
+        android:id="@+id/navigation_repeater"
+        android:icon="@drawable/ic_device_network_wifi"
+        android:title="Repeater"/>
+
+    <item
+        android:id="@+id/navigation_tethering"
+        android:icon="@drawable/ic_device_wifi_tethering"
+        android:title="Tethering"/>
+
+    <item
+        android:id="@+id/navigation_settings"
+        android:icon="@drawable/ic_action_settings"
+        android:title="@string/title_activity_settings"/>
+
+</menu>

mobile/src/main/res/xml/pref_settings.xml

@@ -2,21 +2,15 @@
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
     <PreferenceCategory
         android:title="Service">
-        <be.mygod.vpnhotspot.preference.AlwaysAutoCompleteEditTextPreference
-            android:key="service.upstream"
-            android:title="Upstream interface"
-            android:summary="%s"
-            android:defaultValue="tun0"/>
-        <be.mygod.vpnhotspot.preference.AlwaysAutoCompleteEditTextPreference
-            android:key="service.wifi"
-            android:title="Wi-Fi interface"
-            android:summary="%s"
-            android:defaultValue="wlan0"/>
         <AutoSummaryEditTextPreference
             android:key="service.dns"
             android:title="Downstream DNS server:port"
             android:summary="%s"
             android:defaultValue="8.8.8.8:53"/>
+        <Preference
+            android:key="service.clean"
+            android:title="Clean routing rules"
+            android:summary="Only use after having shut down everything"/>
     </PreferenceCategory>
     <PreferenceCategory
         android:title="Misc">