Revert "ui: port syspolicy handler code to new app (#302)" (#303)

This reverts commit f14836a750.

android/src/main/java/com/tailscale/ipn/App.kt

@@ -15,7 +15,6 @@ import android.content.ContentResolver
 import android.content.ContentValues
 import android.content.Context
 import android.content.Intent
-import android.content.RestrictionsManager
 import android.content.SharedPreferences
 import android.content.pm.PackageInfo
 import android.content.pm.PackageManager
@@ -38,10 +37,6 @@ import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
 import androidx.security.crypto.EncryptedSharedPreferences
 import androidx.security.crypto.MasterKey
-import com.tailscale.ipn.mdm.AlwaysNeverUserDecidesMDMSetting
-import com.tailscale.ipn.mdm.BooleanMDMSetting
-import com.tailscale.ipn.mdm.ShowHideMDMSetting
-import com.tailscale.ipn.mdm.StringMDMSetting
 import com.tailscale.ipn.ui.localapi.Client
 import com.tailscale.ipn.ui.localapi.Request
 import com.tailscale.ipn.ui.model.Ipn
@@ -456,34 +451,4 @@ class App : Application(), libtailscale.AppContext {
 
     return downloads
   }
-
-  @Throws(IOException::class, GeneralSecurityException::class)
-  override fun getSyspolicyBooleanValue(key: String): Boolean {
-    val manager = getSystemService(Context.RESTRICTIONS_SERVICE) as RestrictionsManager
-    return BooleanMDMSetting(key, key).getFrom(manager.applicationRestrictions, this)
-  }
-
-  @Throws(IOException::class, GeneralSecurityException::class)
-  override fun getSyspolicyStringValue(key: String): String {
-    val manager = getSystemService(Context.RESTRICTIONS_SERVICE) as RestrictionsManager
-
-    // Create a single instance for each setting type with given key
-    val alwaysNeverSetting = AlwaysNeverUserDecidesMDMSetting(key, key)
-    val showHideSetting = ShowHideMDMSetting(key, key)
-    val stringSetting = StringMDMSetting(key, key)
-
-    // Use a when statement to replace multiple if-else for cleaner logic
-    return when {
-      alwaysNeverSetting.keyExists(key) ->
-          alwaysNeverSetting.getFrom(manager.applicationRestrictions, this).value
-      showHideSetting.keyExists(key) ->
-          showHideSetting.getFrom(manager.applicationRestrictions, this).value
-      stringSetting.keyExists(key) ->
-          stringSetting.getFrom(manager.applicationRestrictions, this) ?: ""
-      else -> {
-        Log.d("MDM", "$key is not defined on Android. Returning empty.")
-        ""
-      }
-    }
-  }
 }

android/src/main/java/com/tailscale/ipn/mdm/MDMSettingsDefinitions.kt

@@ -10,23 +10,8 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 
 abstract class MDMSetting<T>(defaultValue: T, val key: String, val localizedTitle: String) {
-  private val keys = mutableSetOf<String>()
-
-    init {
-        registerKey(key)
-    }
   val flow: StateFlow<T> = MutableStateFlow<T>(defaultValue)
 
-  private fun registerKey(key: String) {
-    if (!keyExists(key)) {
-        keys.add(key)
-    }
-}
-
-fun keyExists(key: String): Boolean {
-    return keys.contains(key)
-}
-
   fun setFrom(bundle: Bundle?, app: App) {
     val v = getFrom(bundle, app)
     flow.set(v)

libtailscale/interfaces.go

@@ -45,12 +45,6 @@ type AppContext interface {
 	// GetPlatformDNSConfig gets a string representation of the current DNS
 	// configuration.
 	GetPlatformDNSConfig() string
-
-	// GetSyspolicyStringValue returns the current string value for the given system policy.
-	GetSyspolicyStringValue(key string) (string, error)
-
-	// GetSyspolicyBooleanValue returns whether the given system policy is enabled.
-	GetSyspolicyBooleanValue(key string) (bool, error)
 }
 
 // IPNService corresponds to our IPNService in Java.

libtailscale/syspolicy_handler.go

@@ -1,47 +0,0 @@
-// Copyright (c) Tailscale Inc & AUTHORS
-// SPDX-License-Identifier: BSD-3-Clause
-
-package libtailscale
-
-import (
-	"log"
-
-	"tailscale.com/util/syspolicy"
-)
-
-// androidHandler is a syspolicy handler for the Android version of the Tailscale client,
-// which lets the main networking code read values set via the Android RestrictionsManager.
-type androidHandler struct {
-	a *App
-}
-
-func (h androidHandler) ReadString(key string) (string, error) {
-	if key == "" {
-		return "", syspolicy.ErrNoSuchKey
-	}
-	retVal, err := h.a.appCtx.GetSyspolicyStringValue(key)
-	if err != nil {
-		log.Printf("syspolicy: failed to get string value via gomobile: %v", err)
-	}
-	return retVal, err
-}
-
-func (h androidHandler) ReadBoolean(key string) (bool, error) {
-	if key == "" {
-		return false, syspolicy.ErrNoSuchKey
-	}
-	retVal, err := h.a.appCtx.GetSyspolicyBooleanValue(key)
-	if err != nil {
-		log.Printf("syspolicy: failed to get bool value via gomobile: %v", err)
-	}
-	return retVal, err
-}
-
-func (h androidHandler) ReadUInt64(key string) (uint64, error) {
-	if key == "" {
-		return 0, syspolicy.ErrNoSuchKey
-	}
-	// TODO(angott): drop ReadUInt64 everywhere. We are not using it.
-	log.Fatalf("ReadUInt64 is not implemented on Android")
-	return 0, nil
-}

libtailscale/tailscale.go

@@ -18,7 +18,6 @@ import (
 	"tailscale.com/types/logger"
 	"tailscale.com/types/logid"
 	"tailscale.com/util/clientmetric"
-	"tailscale.com/util/syspolicy"
 )
 
 const defaultMTU = 1280 // minimalMTU from wgengine/userspace.go
@@ -39,7 +38,6 @@ func newApp(dataDir, directFileRoot string, appCtx AppContext) Application {
 
 	a.store = newStateStore(a.appCtx)
 	interfaces.RegisterInterfaceGetter(a.getInterfaces)
-	syspolicy.RegisterHandler(androidHandler{a: a})
 	go func() {
 		defer func() {
 			if p := recover(); p != nil {