[Catalyst] Add ApiPermissionChecker and refactor code for preference service

Bug: 373895596
Flag: EXEMPT library
Test: manual
Change-Id: I30788cc7c247a3a1662abe24d7bc07611d6004bb

5 files changed, 58 insertions, 20 deletions

diff --git a/packages/SettingsLib/Graph/src/com/android/settingslib/graph/PreferenceSetterApi.kt b/packages/SettingsLib/Graph/src/com/android/settingslib/graph/PreferenceSetterApi.kt
index 6e4db1d90484..7cfce0d85cd4 100644
--- a/packages/SettingsLib/Graph/src/com/android/settingslib/graph/PreferenceSetterApi.kt
+++ b/packages/SettingsLib/Graph/src/com/android/settingslib/graph/PreferenceSetterApi.kt
@@ -22,6 +22,7 @@ import androidx.annotation.IntDef
 import com.android.settingslib.graph.proto.PreferenceValueProto
 import com.android.settingslib.ipc.ApiDescriptor
 import com.android.settingslib.ipc.ApiHandler
+import com.android.settingslib.ipc.ApiPermissionChecker
 import com.android.settingslib.ipc.IntMessageCodec
 import com.android.settingslib.ipc.MessageCodec
 import com.android.settingslib.metadata.BooleanValue
@@ -45,7 +46,11 @@ data class PreferenceSetterRequest(
     PreferenceSetterResult.OK,
     PreferenceSetterResult.UNSUPPORTED,
     PreferenceSetterResult.DISABLED,
+    PreferenceSetterResult.RESTRICTED,
     PreferenceSetterResult.UNAVAILABLE,
+    PreferenceSetterResult.REQUIRE_APP_PERMISSION,
+    PreferenceSetterResult.REQUIRE_USER_AGREEMENT,
+    PreferenceSetterResult.DISALLOW,
     PreferenceSetterResult.INVALID_REQUEST,
     PreferenceSetterResult.INTERNAL_ERROR,
 )
@@ -87,14 +92,17 @@ class PreferenceSetterApiDescriptor(override val id: Int) :
 }
 
 /** Preference setter API implementation. */
-class PreferenceSetterApiHandler(override val id: Int) : ApiHandler<PreferenceSetterRequest, Int> {
+class PreferenceSetterApiHandler(
+    override val id: Int,
+    private val permissionChecker: ApiPermissionChecker<PreferenceSetterRequest>,
+) : ApiHandler<PreferenceSetterRequest, Int> {
 
     override fun hasPermission(
         application: Application,
         myUid: Int,
         callingUid: Int,
         request: PreferenceSetterRequest,
-    ): Boolean = true
+    ) = permissionChecker.hasPermission(application, myUid, callingUid, request)
 
     override suspend fun invoke(
         application: Application,
diff --git a/packages/SettingsLib/Ipc/src/com/android/settingslib/ipc/ApiHandler.kt b/packages/SettingsLib/Ipc/src/com/android/settingslib/ipc/ApiHandler.kt
index 802141dae7ec..4febd89a7da4 100644
--- a/packages/SettingsLib/Ipc/src/com/android/settingslib/ipc/ApiHandler.kt
+++ b/packages/SettingsLib/Ipc/src/com/android/settingslib/ipc/ApiHandler.kt
@@ -56,6 +56,27 @@ interface ApiDescriptor<Request, Response> {
     val responseCodec: MessageCodec<Response>
 }
 
+/** Permission checker for api. */
+fun interface ApiPermissionChecker<R> {
+    /**
+     * Returns if the request is permitted.
+     *
+     * @param application application context
+     * @param myUid uid of current process
+     * @param callingUid uid of peer process
+     * @param request API request
+     * @return `false` if permission is denied, otherwise `true`
+     */
+    fun hasPermission(application: Application, myUid: Int, callingUid: Int, request: R): Boolean
+
+    companion object {
+        private val ALWAYS_ALLOW = ApiPermissionChecker<Any> { _, _, _, _ -> true }
+
+        @Suppress("UNCHECKED_CAST")
+        fun <T> alwaysAllow(): ApiPermissionChecker<T> = ALWAYS_ALLOW as ApiPermissionChecker<T>
+    }
+}
+
 /**
  * Handler of API.
  *
@@ -64,18 +85,8 @@ interface ApiDescriptor<Request, Response> {
  *
  * The implementation must be threadsafe.
  */
-interface ApiHandler<Request, Response> : ApiDescriptor<Request, Response> {
-    /**
-     * Returns if the request is permitted.
-     *
-     * @return `false` if permission is denied, otherwise `true`
-     */
-    fun hasPermission(
-        application: Application,
-        myUid: Int,
-        callingUid: Int,
-        request: Request,
-    ): Boolean
+interface ApiHandler<Request, Response> :
+    ApiDescriptor<Request, Response>, ApiPermissionChecker<Request> {
 
     /**
      * Invokes the API.
diff --git a/packages/SettingsLib/Service/src/com/android/settingslib/service/PreferenceGraphApi.kt b/packages/SettingsLib/Service/src/com/android/settingslib/service/PreferenceGraphApi.kt
index 12c15b538f98..1823ba641775 100644
--- a/packages/SettingsLib/Service/src/com/android/settingslib/service/PreferenceGraphApi.kt
+++ b/packages/SettingsLib/Service/src/com/android/settingslib/service/PreferenceGraphApi.kt
@@ -19,11 +19,13 @@ package com.android.settingslib.service
 import android.app.Application
 import com.android.settingslib.graph.GetPreferenceGraphApiHandler
 import com.android.settingslib.graph.GetPreferenceGraphRequest
+import com.android.settingslib.ipc.ApiPermissionChecker
 import com.android.settingslib.preference.PreferenceScreenProvider
 
 /** Api to get preference graph. */
 internal class PreferenceGraphApi(
-    preferenceScreenProviders: Set<Class<out PreferenceScreenProvider>>
+    preferenceScreenProviders: Set<Class<out PreferenceScreenProvider>>,
+    private val permissionChecker: ApiPermissionChecker<GetPreferenceGraphRequest>,
 ) : GetPreferenceGraphApiHandler(preferenceScreenProviders) {
 
     override val id: Int
@@ -34,5 +36,5 @@ internal class PreferenceGraphApi(
         myUid: Int,
         callingUid: Int,
         request: GetPreferenceGraphRequest,
-    ) = true
+    ) = permissionChecker.hasPermission(application, myUid, callingUid, request)
 }
diff --git a/packages/SettingsLib/Service/src/com/android/settingslib/service/PreferenceService.kt b/packages/SettingsLib/Service/src/com/android/settingslib/service/PreferenceService.kt
index 63b5c5aaa35d..ed748bb58a9a 100644
--- a/packages/SettingsLib/Service/src/com/android/settingslib/service/PreferenceService.kt
+++ b/packages/SettingsLib/Service/src/com/android/settingslib/service/PreferenceService.kt
@@ -16,8 +16,11 @@
 
 package com.android.settingslib.service
 
+import com.android.settingslib.graph.GetPreferenceGraphRequest
 import com.android.settingslib.graph.PreferenceSetterApiHandler
+import com.android.settingslib.graph.PreferenceSetterRequest
 import com.android.settingslib.ipc.ApiHandler
+import com.android.settingslib.ipc.ApiPermissionChecker
 import com.android.settingslib.ipc.MessengerService
 import com.android.settingslib.ipc.PermissionChecker
 import com.android.settingslib.preference.PreferenceScreenProvider
@@ -29,15 +32,20 @@ import com.android.settingslib.preference.PreferenceScreenProvider
  * [PREFERENCE_SERVICE_ACTION].
  */
 open class PreferenceService(
+    name: String = "PreferenceService",
     permissionChecker: PermissionChecker = PermissionChecker { _, _, _ -> true },
     preferenceScreenProviders: Set<Class<out PreferenceScreenProvider>> = setOf(),
-    enablePreferenceSetterApi: Boolean = false,
-    name: String = "PreferenceService",
+    graphPermissionChecker: ApiPermissionChecker<GetPreferenceGraphRequest>? = null,
+    setterPermissionChecker: ApiPermissionChecker<PreferenceSetterRequest>? = null,
+    vararg apiHandlers: ApiHandler<*, *>,
 ) :
     MessengerService(
         mutableListOf<ApiHandler<*, *>>().apply {
-            add(PreferenceGraphApi(preferenceScreenProviders))
-            if (enablePreferenceSetterApi) add(PreferenceSetterApiHandler(API_PREFERENCE_SETTER))
+            graphPermissionChecker?.let { add(PreferenceGraphApi(preferenceScreenProviders, it)) }
+            setterPermissionChecker?.let {
+                add(PreferenceSetterApiHandler(API_PREFERENCE_SETTER, it))
+            }
+            addAll(apiHandlers)
         },
         permissionChecker,
         name,
diff --git a/packages/SettingsLib/Service/src/com/android/settingslib/service/ServiceApiConstants.kt b/packages/SettingsLib/Service/src/com/android/settingslib/service/ServiceApiConstants.kt
index 1f38a6678eae..7655daa6cf21 100644
--- a/packages/SettingsLib/Service/src/com/android/settingslib/service/ServiceApiConstants.kt
+++ b/packages/SettingsLib/Service/src/com/android/settingslib/service/ServiceApiConstants.kt
@@ -18,5 +18,14 @@ package com.android.settingslib.service
 
 const val PREFERENCE_SERVICE_ACTION = "com.android.settingslib.PREFERENCE_SERVICE"
 
+/** API id for retrieving preference graph. */
 internal const val API_GET_PREFERENCE_GRAPH = 1
+
+/** API id for preference value setter. */
 internal const val API_PREFERENCE_SETTER = 2
+
+/**
+ * The max API id reserved for internal preference service usages. Custom API id should start with
+ * **1000** to avoid conflict.
+ */
+internal const val API_MAX_RESERVED = 999