V2: Use resolution to round sensor event values
Add method to utilize a sensor's specified resolution value to ensure
data isn't provided that is more fine-grained than expected. This
helps mitigate sensor calibration fingerprinting attacks.
Bug: 147725937
Test: Verify accel sensor data isn't more fine grained than its
specified resolution
Test: Verify that the max range specified is a multiple of the
resolution
Change-Id: I30ff66d9deb10c84319a63f9964477d8e469650d
diff --git a/services/sensorservice/SensorDeviceUtils.cpp b/services/sensorservice/SensorDeviceUtils.cpp
index dbafffe..0dcf8c0 100644
--- a/services/sensorservice/SensorDeviceUtils.cpp
+++ b/services/sensorservice/SensorDeviceUtils.cpp
@@ -17,17 +17,101 @@
#include "SensorDeviceUtils.h"
#include <android/hardware/sensors/1.0/ISensors.h>
+#include <android/hardware/sensors/2.1/ISensors.h>
#include <utils/Log.h>
#include <chrono>
#include <thread>
using ::android::hardware::Void;
+using SensorTypeV2_1 = android::hardware::sensors::V2_1::SensorType;
using namespace android::hardware::sensors::V1_0;
namespace android {
namespace SensorDeviceUtils {
+void quantizeSensorEventValues(sensors_event_t *event, float resolution) {
+ LOG_FATAL_IF(resolution == 0, "Resolution must be specified for all sensors!");
+ if (resolution == 0) {
+ return;
+ }
+
+ size_t axes = 0;
+ switch ((SensorTypeV2_1)event->type) {
+ case SensorTypeV2_1::ACCELEROMETER:
+ case SensorTypeV2_1::MAGNETIC_FIELD:
+ case SensorTypeV2_1::ORIENTATION:
+ case SensorTypeV2_1::GYROSCOPE:
+ case SensorTypeV2_1::GRAVITY:
+ case SensorTypeV2_1::LINEAR_ACCELERATION:
+ case SensorTypeV2_1::MAGNETIC_FIELD_UNCALIBRATED:
+ case SensorTypeV2_1::GYROSCOPE_UNCALIBRATED:
+ case SensorTypeV2_1::ACCELEROMETER_UNCALIBRATED:
+ axes = 3;
+ break;
+ case SensorTypeV2_1::GAME_ROTATION_VECTOR:
+ axes = 4;
+ break;
+ case SensorTypeV2_1::ROTATION_VECTOR:
+ case SensorTypeV2_1::GEOMAGNETIC_ROTATION_VECTOR:
+ axes = 5;
+ break;
+ case SensorTypeV2_1::DEVICE_ORIENTATION:
+ case SensorTypeV2_1::LIGHT:
+ case SensorTypeV2_1::PRESSURE:
+ case SensorTypeV2_1::TEMPERATURE:
+ case SensorTypeV2_1::PROXIMITY:
+ case SensorTypeV2_1::RELATIVE_HUMIDITY:
+ case SensorTypeV2_1::AMBIENT_TEMPERATURE:
+ case SensorTypeV2_1::SIGNIFICANT_MOTION:
+ case SensorTypeV2_1::STEP_DETECTOR:
+ case SensorTypeV2_1::TILT_DETECTOR:
+ case SensorTypeV2_1::WAKE_GESTURE:
+ case SensorTypeV2_1::GLANCE_GESTURE:
+ case SensorTypeV2_1::PICK_UP_GESTURE:
+ case SensorTypeV2_1::WRIST_TILT_GESTURE:
+ case SensorTypeV2_1::STATIONARY_DETECT:
+ case SensorTypeV2_1::MOTION_DETECT:
+ case SensorTypeV2_1::HEART_BEAT:
+ case SensorTypeV2_1::LOW_LATENCY_OFFBODY_DETECT:
+ case SensorTypeV2_1::HINGE_ANGLE:
+ axes = 1;
+ break;
+ case SensorTypeV2_1::POSE_6DOF:
+ axes = 15;
+ break;
+ default:
+ // No other sensors have data that needs to be rounded.
+ break;
+ }
+
+ // sensor_event_t is a union so we're able to perform the same quanitization action for most
+ // sensors by only knowing the number of axes their output data has.
+ for (size_t i = 0; i < axes; i++) {
+ quantizeValue(&event->data[i], resolution);
+ }
+}
+
+float defaultResolutionForType(int type) {
+ switch ((SensorTypeV2_1)type) {
+ case SensorTypeV2_1::SIGNIFICANT_MOTION:
+ case SensorTypeV2_1::STEP_DETECTOR:
+ case SensorTypeV2_1::STEP_COUNTER:
+ case SensorTypeV2_1::TILT_DETECTOR:
+ case SensorTypeV2_1::WAKE_GESTURE:
+ case SensorTypeV2_1::GLANCE_GESTURE:
+ case SensorTypeV2_1::PICK_UP_GESTURE:
+ case SensorTypeV2_1::WRIST_TILT_GESTURE:
+ case SensorTypeV2_1::STATIONARY_DETECT:
+ case SensorTypeV2_1::MOTION_DETECT:
+ return 1.0f;
+ default:
+ // fall through and return 0 for all other types
+ break;
+ }
+ return 0.0f;
+}
+
HidlServiceRegistrationWaiter::HidlServiceRegistrationWaiter() {
}