Remove fallback upstream monitor

This option has been deprecated. As a replacement, if one wants to forbid fallback communication, a global routed VPN can be used instead.

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

@@ -11,7 +11,6 @@ import androidx.preference.SwitchPreference
 import be.mygod.vpnhotspot.App.Companion.app
 import be.mygod.vpnhotspot.net.Routing
 import be.mygod.vpnhotspot.net.Routing.Companion.IPTABLES
-import be.mygod.vpnhotspot.net.monitor.FallbackUpstreamMonitor
 import be.mygod.vpnhotspot.net.monitor.IpMonitor
 import be.mygod.vpnhotspot.net.monitor.UpstreamMonitor
 import be.mygod.vpnhotspot.preference.AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat
@@ -132,24 +131,23 @@ class SettingsPreferenceFragment : PreferenceFragmentCompat() {
 
     override fun onDisplayPreferenceDialog(preference: Preference) {
         when (preference.key) {
-            UpstreamMonitor.KEY, FallbackUpstreamMonitor.KEY ->
-                AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat().apply {
-                    setArguments(preference.key, try {
-                        NetworkInterface.getNetworkInterfaces().asSequence()
-                                .filter {
-                                    try {
-                                        it.isUp && !it.isLoopback && it.interfaceAddresses.isNotEmpty()
-                                    } catch (_: SocketException) {
-                                        false
-                                    }
+            UpstreamMonitor.KEY -> AlwaysAutoCompleteEditTextPreferenceDialogFragmentCompat().apply {
+                setArguments(preference.key, try {
+                    NetworkInterface.getNetworkInterfaces().asSequence()
+                            .filter {
+                                try {
+                                    it.isUp && !it.isLoopback && it.interfaceAddresses.isNotEmpty()
+                                } catch (_: SocketException) {
+                                    false
                                 }
-                                .map { it.name }.sorted().toList().toTypedArray()
-                    } catch (e: SocketException) {
-                        Timber.d(e)
-                        emptyArray<String>()
-                    })
-                    setTargetFragment(this@SettingsPreferenceFragment, 0)
-                }.show(fragmentManager ?: return, preference.key)
+                            }
+                            .map { it.name }.sorted().toList().toTypedArray()
+                } catch (e: SocketException) {
+                    Timber.d(e)
+                    emptyArray<String>()
+                })
+                setTargetFragment(this@SettingsPreferenceFragment, 0)
+            }.show(fragmentManager ?: return, preference.key)
             else -> super.onDisplayPreferenceDialog(preference)
         }
     }

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

@@ -3,7 +3,7 @@ package be.mygod.vpnhotspot.net
 import android.os.Build
 import be.mygod.vpnhotspot.App.Companion.app
 import be.mygod.vpnhotspot.R
-import be.mygod.vpnhotspot.net.monitor.FallbackUpstreamMonitor
+import be.mygod.vpnhotspot.net.monitor.DefaultNetworkMonitor
 import be.mygod.vpnhotspot.net.monitor.IpNeighbourMonitor
 import be.mygod.vpnhotspot.net.monitor.TrafficRecorder
 import be.mygod.vpnhotspot.net.monitor.UpstreamMonitor
@@ -283,16 +283,14 @@ class Routing(val downstream: String, ownerAddress: InterfaceAddress? = null) :
 
     fun stop() {
         IpNeighbourMonitor.unregisterCallback(this)
-        FallbackUpstreamMonitor.unregisterCallback(fallbackUpstream)
+        DefaultNetworkMonitor.unregisterCallback(fallbackUpstream)
         UpstreamMonitor.unregisterCallback(upstream)
     }
 
     fun commit(localOnly: Boolean = false) {
         transaction.commit()
         Timber.i("Started routing for $downstream")
-        if (localOnly || masqueradeMode != MasqueradeMode.Netd) {
-            FallbackUpstreamMonitor.registerCallback(fallbackUpstream)
-        }
+        if (localOnly || masqueradeMode != MasqueradeMode.Netd) DefaultNetworkMonitor.registerCallback(fallbackUpstream)
         UpstreamMonitor.registerCallback(upstream)
         IpNeighbourMonitor.registerCallback(this)
     }

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

@@ -1,41 +0,0 @@
-package be.mygod.vpnhotspot.net.monitor
-
-import android.content.SharedPreferences
-import be.mygod.vpnhotspot.App.Companion.app
-
-abstract class FallbackUpstreamMonitor private constructor() : UpstreamMonitor() {
-    companion object : SharedPreferences.OnSharedPreferenceChangeListener {
-        const val KEY = "service.upstream.fallback"
-
-        init {
-            app.pref.registerOnSharedPreferenceChangeListener(this)
-        }
-
-        private fun generateMonitor(): UpstreamMonitor {
-            val upstream = app.pref.getString(KEY, null)
-            return if (upstream.isNullOrEmpty()) DefaultNetworkMonitor else InterfaceMonitor(upstream)
-        }
-        private var monitor = generateMonitor()
-
-        fun registerCallback(callback: Callback) = synchronized(this) { monitor.registerCallback(callback) }
-        fun unregisterCallback(callback: Callback) = synchronized(this) { monitor.unregisterCallback(callback) }
-
-        override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
-            if (key == KEY) synchronized(this) {
-                val old = monitor
-                val callbacks = synchronized(old) {
-                    val callbacks = old.callbacks.toList()
-                    old.callbacks.clear()
-                    old.destroyLocked()
-                    callbacks
-                }
-                val new = generateMonitor()
-                monitor = new
-                for (callback in callbacks) {
-                    callback.onLost()
-                    new.registerCallback(callback)
-                }
-            }
-        }
-    }
-}