[PATCH 2/3] - AppOps/PrivacyGuard: New Sensor checks [native]

Add two AppOps for sensor access:
- OP_MOTION_SENSORS (default: allow, strict)
- OP_OTHER_SENSORS  (default: allow)

This change updated the AppOPs binder for the newly defined Ops,
implements the logic for the sensors and adapts the logic for
checking the Ops, if an Op is not linked to a permission.

Change-Id: I17bd646c81346f43d1ffdd2dd85dd7c934cd3bd7

include/binder/AppOpsManager.h

@@ -104,7 +104,9 @@ class AppOpsManager
         OP_BOOT_COMPLETED = 66,
         OP_NFC_CHANGE = 67,
         OP_DATA_CONNECT_CHANGE = 68,
-        OP_SU = 69
+        OP_SU = 69,
+        OP_MOTION_SENSORS = 70,
+        OP_OTHER_SENSORS = 71
     };
 
     AppOpsManager();

libs/gui/Sensor.cpp

@@ -58,6 +58,7 @@ Sensor::Sensor(struct sensor_t const& hwSensor, const uuid_t& uuid, int halVersi
     mMinDelay = hwSensor.minDelay;
     mFlags = 0;
     mUuid = uuid;
+    mRequiredAppOp = AppOpsManager::OP_OTHER_SENSORS;  //default, other values are explicitly set
 
     // Set fifo event count zero for older devices which do not support batching. Fused
     // sensors also have their fifo counts set to zero.
@@ -92,6 +93,7 @@ Sensor::Sensor(struct sensor_t const& hwSensor, const uuid_t& uuid, int halVersi
     switch (mType) {
     case SENSOR_TYPE_ACCELEROMETER:
         mStringType = SENSOR_STRING_TYPE_ACCELEROMETER;
+        mRequiredAppOp = AppOpsManager::OP_MOTION_SENSORS;
         mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
         break;
     case SENSOR_TYPE_AMBIENT_TEMPERATURE:
@@ -112,10 +114,12 @@ Sensor::Sensor(struct sensor_t const& hwSensor, const uuid_t& uuid, int halVersi
         break;
     case SENSOR_TYPE_GYROSCOPE:
         mStringType = SENSOR_STRING_TYPE_GYROSCOPE;
+        mRequiredAppOp = AppOpsManager::OP_MOTION_SENSORS;
         mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
         break;
     case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
         mStringType = SENSOR_STRING_TYPE_GYROSCOPE_UNCALIBRATED;
+        mRequiredAppOp = AppOpsManager::OP_MOTION_SENSORS;
         mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
         break;
     case SENSOR_TYPE_HEART_RATE: {
@@ -133,6 +137,7 @@ Sensor::Sensor(struct sensor_t const& hwSensor, const uuid_t& uuid, int halVersi
         break;
     case SENSOR_TYPE_LINEAR_ACCELERATION:
         mStringType = SENSOR_STRING_TYPE_LINEAR_ACCELERATION;
+        mRequiredAppOp = AppOpsManager::OP_MOTION_SENSORS;
         mFlags |= SENSOR_FLAG_CONTINUOUS_MODE;
         break;
     case SENSOR_TYPE_MAGNETIC_FIELD:
@@ -169,16 +174,19 @@ Sensor::Sensor(struct sensor_t const& hwSensor, const uuid_t& uuid, int halVersi
     case SENSOR_TYPE_SIGNIFICANT_MOTION:
         mStringType = SENSOR_STRING_TYPE_SIGNIFICANT_MOTION;
         mFlags |= SENSOR_FLAG_ONE_SHOT_MODE;
+        mRequiredAppOp = AppOpsManager::OP_MOTION_SENSORS;
         if (halVersion < SENSORS_DEVICE_API_VERSION_1_3) {
             mFlags |= SENSOR_FLAG_WAKE_UP;
         }
         break;
     case SENSOR_TYPE_STEP_COUNTER:
         mStringType = SENSOR_STRING_TYPE_STEP_COUNTER;
+        mRequiredAppOp = AppOpsManager::OP_MOTION_SENSORS;
         mFlags |= SENSOR_FLAG_ON_CHANGE_MODE;
         break;
     case SENSOR_TYPE_STEP_DETECTOR:
         mStringType = SENSOR_STRING_TYPE_STEP_DETECTOR;
+        mRequiredAppOp = AppOpsManager::OP_MOTION_SENSORS;
         mFlags |= SENSOR_FLAG_SPECIAL_REPORTING_MODE;
         break;
     case SENSOR_TYPE_TEMPERATURE:

services/sensorservice/SensorService.cpp

@@ -1254,6 +1254,20 @@ status_t SensorService::flushSensor(const sp<SensorEventConnection>& connection,
 
 bool SensorService::canAccessSensor(const Sensor& sensor, const char* operation,
         const String16& opPackageName) {
+
+    // Due to the new SENSOR AppOps, which do not correspond to any permission,
+    // we need to check for the AppOp BEFORE checking any permission
+    const int32_t opCode = sensor.getRequiredAppOp();
+    if (opCode >= 0) {
+        AppOpsManager appOps;
+        if (appOps.noteOp(opCode, IPCThreadState::self()->getCallingUid(), opPackageName)
+                        != AppOpsManager::MODE_ALLOWED) {
+            ALOGE("%s a sensor (%s) without enabled required app op: %d",
+                    operation, sensor.getName().string(), opCode);
+            return false;
+        }
+    }
+
     const String8& requiredPermission = sensor.getRequiredPermission();
 
     if (requiredPermission.length() <= 0) {
@@ -1276,17 +1290,6 @@ bool SensorService::canAccessSensor(const Sensor& sensor, const char* operation,
         return false;
     }
 
-    const int32_t opCode = sensor.getRequiredAppOp();
-    if (opCode >= 0) {
-        AppOpsManager appOps;
-        if (appOps.noteOp(opCode, IPCThreadState::self()->getCallingUid(), opPackageName)
-                        != AppOpsManager::MODE_ALLOWED) {
-            ALOGE("%s a sensor (%s) without enabled required app op: %d",
-                    operation, sensor.getName().string(), opCode);
-            return false;
-        }
-    }
-
     return true;
 }