Introduce AttributionAndPermissionUtils.

The CameraService class is getting large and permission checking is
becoming a large portion of it. Separate this logic out into its own
utils class to make it easier to find code responsible for verifying
client permissions and the identity of the caller.

Bug: 190657833
Test: Smoke testof GCA, CtsCameraTestCases
Change-Id: I305706846db399eb92c8409271fb3e591539032f
diff --git a/services/camera/libcameraservice/CameraService.cpp b/services/camera/libcameraservice/CameraService.cpp
index 2d55f39..ebe771e 100644
--- a/services/camera/libcameraservice/CameraService.cpp
+++ b/services/camera/libcameraservice/CameraService.cpp
@@ -38,7 +38,6 @@
 #include <aidl/AidlCameraService.h>
 #include <android-base/macros.h>
 #include <android-base/parseint.h>
-#include <android/permission/PermissionChecker.h>
 #include <binder/ActivityManager.h>
 #include <binder/AppOpsManager.h>
 #include <binder/IPCThreadState.h>
@@ -129,20 +128,16 @@
 
 // ----------------------------------------------------------------------------
 
-static const std::string sDumpPermission("android.permission.DUMP");
-static const std::string sManageCameraPermission("android.permission.MANAGE_CAMERA");
-static const std::string sCameraPermission("android.permission.CAMERA");
-static const std::string sSystemCameraPermission("android.permission.SYSTEM_CAMERA");
-static const std::string sCameraHeadlessSystemUserPermission(
-        "android.permission.CAMERA_HEADLESS_SYSTEM_USER");
-static const std::string sCameraPrivacyAllowlistPermission(
-        "android.permission.CAMERA_PRIVACY_ALLOWLIST");
-static const std::string
-        sCameraSendSystemEventsPermission("android.permission.CAMERA_SEND_SYSTEM_EVENTS");
-static const std::string sCameraOpenCloseListenerPermission(
-        "android.permission.CAMERA_OPEN_CLOSE_LISTENER");
-static const std::string
-        sCameraInjectExternalCameraPermission("android.permission.CAMERA_INJECT_EXTERNAL_CAMERA");
+// Permission strings (references to AttributionAndPermissionUtils for brevity)
+static const std::string &sDumpPermission =
+        AttributionAndPermissionUtils::sDumpPermission;
+static const std::string &sManageCameraPermission =
+        AttributionAndPermissionUtils::sManageCameraPermission;
+static const std::string &sCameraSendSystemEventsPermission =
+        AttributionAndPermissionUtils::sCameraSendSystemEventsPermission;
+static const std::string &sCameraInjectExternalCameraPermission =
+        AttributionAndPermissionUtils::sCameraInjectExternalCameraPermission;
+
 // Constant integer for FGS Logging, used to denote the API type for logger
 static const int LOG_FGS_CAMERA_API = 1;
 const char *sFileName = "lastOpenSessionDumpFile";
@@ -158,9 +153,13 @@
 static std::set<std::string> sServiceErrorEventSet;
 
 CameraService::CameraService(
-        std::shared_ptr<CameraServiceProxyWrapper> cameraServiceProxyWrapper) :
+        std::shared_ptr<CameraServiceProxyWrapper> cameraServiceProxyWrapper,
+        std::shared_ptr<AttributionAndPermissionUtils> attributionAndPermissionUtils) :
         mCameraServiceProxyWrapper(cameraServiceProxyWrapper == nullptr ?
                 std::make_shared<CameraServiceProxyWrapper>() : cameraServiceProxyWrapper),
+        mAttributionAndPermissionUtils(attributionAndPermissionUtils == nullptr ?
+                std::make_shared<AttributionAndPermissionUtils>(this)\
+                : attributionAndPermissionUtils),
         mEventLog(DEFAULT_EVENT_LOG_LENGTH),
         mNumberOfCameras(0),
         mNumberOfCamerasWithoutSystemCamera(0),
@@ -215,7 +214,7 @@
 
     mUidPolicy = new UidPolicy(this);
     mUidPolicy->registerSelf();
-    mSensorPrivacyPolicy = new SensorPrivacyPolicy(this);
+    mSensorPrivacyPolicy = new SensorPrivacyPolicy(this, mAttributionAndPermissionUtils);
     mSensorPrivacyPolicy->registerSelf();
     mInjectionStatusListener = new InjectionStatusListener(this);
 
@@ -708,34 +707,15 @@
     broadcastTorchModeStatus(cameraId, newStatus, systemCameraKind);
 }
 
-static bool isAutomotiveDevice() {
-    // Checks the property ro.hardware.type and returns true if it is
-    // automotive.
-    char value[PROPERTY_VALUE_MAX] = {0};
-    property_get("ro.hardware.type", value, "");
-    return strncmp(value, "automotive", PROPERTY_VALUE_MAX) == 0;
+bool CameraService::isAutomotiveDevice() const {
+    return mAttributionAndPermissionUtils->isAutomotiveDevice();
 }
 
-static bool isHeadlessSystemUserMode() {
-    // Checks if the device is running in headless system user mode
-    // by checking the property ro.fw.mu.headless_system_user.
-    char value[PROPERTY_VALUE_MAX] = {0};
-    property_get("ro.fw.mu.headless_system_user", value, "");
-    return strncmp(value, "true", PROPERTY_VALUE_MAX) == 0;
+bool CameraService::isAutomotivePrivilegedClient(int32_t uid) const {
+    return mAttributionAndPermissionUtils->isAutomotivePrivilegedClient(uid);
 }
 
-static bool isAutomotivePrivilegedClient(int32_t uid) {
-    // Returns false if this is not an automotive device type.
-    if (!isAutomotiveDevice())
-        return false;
-
-    // Returns true if the uid is AID_AUTOMOTIVE_EVS which is a
-    // privileged client uid used for safety critical use cases such as
-    // rear view and surround view.
-    return uid == AID_AUTOMOTIVE_EVS;
-}
-
-bool CameraService::isAutomotiveExteriorSystemCamera(const std::string& cam_id) const{
+bool CameraService::isAutomotiveExteriorSystemCamera(const std::string& cam_id) const {
     // Returns false if this is not an automotive device type.
     if (!isAutomotiveDevice())
         return false;
@@ -780,54 +760,47 @@
     return true;
 }
 
-bool CameraService::checkPermission(const std::string& cameraId, const std::string& permission,
-        const AttributionSourceState& attributionSource, const std::string& message,
-        int32_t attributedOpCode) const{
-    if (isAutomotivePrivilegedClient(attributionSource.uid)) {
-        // If cameraId is empty, then it means that this check is not used for the
-        // purpose of accessing a specific camera, hence grant permission just
-        // based on uid to the automotive privileged client.
-        if (cameraId.empty())
-            return true;
-        // If this call is used for accessing a specific camera then cam_id must be provided.
-        // In that case, only pre-grants the permission for accessing the exterior system only
-        // camera.
-        return isAutomotiveExteriorSystemCamera(cameraId);
-    }
+static AttributionSourceState attributionSourceFromPidAndUid(int callingPid, int callingUid) {
+    AttributionSourceState attributionSource{};
+    attributionSource.pid = callingPid;
+    attributionSource.uid = callingUid;
+    return attributionSource;
+}
 
-    permission::PermissionChecker permissionChecker;
-    return permissionChecker.checkPermissionForPreflight(toString16(permission), attributionSource,
-            toString16(message), attributedOpCode)
-            != permission::PermissionChecker::PERMISSION_HARD_DENIED;
+bool CameraService::hasPermissionsForCamera(int callingPid, int callingUid) const {
+    return hasPermissionsForCamera(std::string(), callingPid, callingUid);
+}
+
+bool CameraService::hasPermissionsForCamera(const std::string& cameraId, int callingPid,
+        int callingUid) const {
+    auto attributionSource = attributionSourceFromPidAndUid(callingPid, callingUid);
+    return mAttributionAndPermissionUtils->hasPermissionsForCamera(cameraId, attributionSource);
 }
 
 bool CameraService::hasPermissionsForSystemCamera(const std::string& cameraId, int callingPid,
-        int callingUid) const{
-    AttributionSourceState attributionSource{};
-    attributionSource.pid = callingPid;
-    attributionSource.uid = callingUid;
-    bool checkPermissionForSystemCamera = checkPermission(cameraId,
-            sSystemCameraPermission, attributionSource, std::string(), AppOpsManager::OP_NONE);
-    bool checkPermissionForCamera = checkPermission(cameraId,
-            sCameraPermission, attributionSource, std::string(), AppOpsManager::OP_NONE);
-    return checkPermissionForSystemCamera && checkPermissionForCamera;
+        int callingUid, bool checkCameraPermissions) const {
+    auto attributionSource = attributionSourceFromPidAndUid(callingPid, callingUid);
+    return mAttributionAndPermissionUtils->hasPermissionsForSystemCamera(
+                cameraId, attributionSource, checkCameraPermissions);
 }
 
 bool CameraService::hasPermissionsForCameraHeadlessSystemUser(const std::string& cameraId,
-        int callingPid, int callingUid) const{
-    AttributionSourceState attributionSource{};
-    attributionSource.pid = callingPid;
-    attributionSource.uid = callingUid;
-    return checkPermission(cameraId, sCameraHeadlessSystemUserPermission, attributionSource,
-            std::string(), AppOpsManager::OP_NONE);
+        int callingPid, int callingUid) const {
+    auto attributionSource = attributionSourceFromPidAndUid(callingPid, callingUid);
+    return mAttributionAndPermissionUtils->hasPermissionsForCameraHeadlessSystemUser(
+                cameraId, attributionSource);
 }
 
-bool CameraService::hasPermissionsForCameraPrivacyAllowlist(int callingPid, int callingUid) const{
-    AttributionSourceState attributionSource{};
-    attributionSource.pid = callingPid;
-    attributionSource.uid = callingUid;
-    return checkPermission(std::string(), sCameraPrivacyAllowlistPermission, attributionSource,
-            std::string(), AppOpsManager::OP_NONE);
+bool CameraService::hasPermissionsForCameraPrivacyAllowlist(int callingPid, int callingUid) const {
+    auto attributionSource = attributionSourceFromPidAndUid(callingPid, callingUid);
+    return mAttributionAndPermissionUtils->hasPermissionsForCameraPrivacyAllowlist(
+            attributionSource);
+}
+
+bool CameraService::hasPermissionsForOpenCloseListener(int callingPid, int callingUid) const {
+    auto attributionSource = attributionSourceFromPidAndUid(callingPid, callingUid);
+    return mAttributionAndPermissionUtils->hasPermissionsForOpenCloseListener(
+            attributionSource);
 }
 
 Status CameraService::getNumberOfCameras(int32_t type, int32_t* numCameras) {
@@ -1272,13 +1245,9 @@
     const std::vector<std::string> *deviceIds = &mNormalDeviceIdsWithoutSystemCamera;
     auto callingPid = CameraThreadState::getCallingPid();
     auto callingUid = CameraThreadState::getCallingUid();
-    AttributionSourceState attributionSource{};
-    attributionSource.pid = callingPid;
-    attributionSource.uid = callingUid;
-    bool checkPermissionForSystemCamera = checkPermission(std::to_string(cameraIdInt),
-                sSystemCameraPermission, attributionSource, std::string(),
-                AppOpsManager::OP_NONE);
-    if (checkPermissionForSystemCamera || getpid() == callingPid) {
+    bool systemCameraPermissions = hasPermissionsForSystemCamera(std::to_string(cameraIdInt),
+            callingPid, callingUid, /* checkCameraPermissions= */ false);
+    if (systemCameraPermissions || getpid() == callingPid) {
         deviceIds = &mNormalDeviceIds;
     }
     if (cameraIdInt < 0 || cameraIdInt >= static_cast<int>(deviceIds->size())) {
@@ -1351,11 +1320,7 @@
     // If it's not calling from cameraserver, check the permission only if
     // android.permission.CAMERA is required. If android.permission.SYSTEM_CAMERA was needed,
     // it would've already been checked in shouldRejectSystemCameraConnection.
-    AttributionSourceState attributionSource{};
-    attributionSource.pid = callingPid;
-    attributionSource.uid = callingUid;
-    bool checkPermissionForCamera = checkPermission(cameraId, sCameraPermission,
-            attributionSource, std::string(), AppOpsManager::OP_NONE);
+    bool checkPermissionForCamera = hasPermissionsForCamera(cameraId, callingPid, callingUid);
     if ((callingPid != getpid()) &&
             (deviceKind != SystemCameraKind::SYSTEM_ONLY_CAMERA) &&
             !checkPermissionForCamera) {
@@ -1541,7 +1506,7 @@
     if (effectiveApiLevel == API_1) { // Camera1 API route
         sp<ICameraClient> tmp = static_cast<ICameraClient*>(cameraCb.get());
         *client = new Camera2Client(cameraService, tmp, cameraService->mCameraServiceProxyWrapper,
-                packageName, featureId, cameraId,
+                cameraService->mAttributionAndPermissionUtils, packageName, featureId, cameraId,
                 api1CameraId, facing, sensorOrientation,
                 clientPid, clientUid, servicePid, overrideForPerfClass, overrideToPortrait,
                 forceSlowJpegMode);
@@ -1551,7 +1516,8 @@
         sp<hardware::camera2::ICameraDeviceCallbacks> tmp =
                 static_cast<hardware::camera2::ICameraDeviceCallbacks*>(cameraCb.get());
         *client = new CameraDeviceClient(cameraService, tmp,
-                cameraService->mCameraServiceProxyWrapper, packageName, systemNativeClient,
+                cameraService->mCameraServiceProxyWrapper,
+                cameraService->mAttributionAndPermissionUtils, packageName, systemNativeClient,
                 featureId, cameraId, facing, sensorOrientation, clientPid, clientUid, servicePid,
                 overrideForPerfClass, overrideToPortrait, originalCameraId);
         ALOGI("%s: Camera2 API, override to portrait %d", __FUNCTION__, overrideToPortrait);
@@ -1716,35 +1682,13 @@
 }
 
 // Can camera service trust the caller based on the calling UID?
-static bool isTrustedCallingUid(uid_t uid) {
-    switch (uid) {
-        case AID_MEDIA:        // mediaserver
-        case AID_CAMERASERVER: // cameraserver
-        case AID_RADIO:        // telephony
-            return true;
-        default:
-            return false;
-    }
+bool CameraService::isTrustedCallingUid(uid_t uid) const {
+    return mAttributionAndPermissionUtils->isTrustedCallingUid(uid);
 }
 
-static status_t getUidForPackage(const std::string &packageName, int userId, /*inout*/uid_t& uid,
-        int err) {
-    PermissionController pc;
-    uid = pc.getPackageUid(toString16(packageName), 0);
-    if (uid <= 0) {
-        ALOGE("Unknown package: '%s'", packageName.c_str());
-        dprintf(err, "Unknown package: '%s'\n", packageName.c_str());
-        return BAD_VALUE;
-    }
-
-    if (userId < 0) {
-        ALOGE("Invalid user: %d", userId);
-        dprintf(err, "Invalid user: %d\n", userId);
-        return BAD_VALUE;
-    }
-
-    uid = multiuser_get_uid(userId, uid);
-    return NO_ERROR;
+status_t CameraService::getUidForPackage(const std::string &packageName, int userId,
+        /*inout*/uid_t& uid, int err) const {
+    return mAttributionAndPermissionUtils->getUidForPackage(packageName, userId, uid, err);
 }
 
 Status CameraService::validateConnectLocked(const std::string& cameraId,
@@ -1798,8 +1742,6 @@
 Status CameraService::validateClientPermissionsLocked(const std::string& cameraId,
         const std::string& clientName, int& clientUid, int& clientPid,
         /*out*/int& originalClientPid) const {
-    AttributionSourceState attributionSource{};
-
     int callingPid = CameraThreadState::getCallingPid();
     int callingUid = CameraThreadState::getCallingUid();
 
@@ -1846,11 +1788,7 @@
     // If it's not calling from cameraserver, check the permission if the
     // device isn't a system only camera (shouldRejectSystemCameraConnection already checks for
     // android.permission.SYSTEM_CAMERA for system only camera devices).
-    attributionSource.pid = clientPid;
-    attributionSource.uid = clientUid;
-    attributionSource.packageName = clientName;
-    bool checkPermissionForCamera = checkPermission(cameraId, sCameraPermission, attributionSource,
-            std::string(), AppOpsManager::OP_NONE);
+    bool checkPermissionForCamera = hasPermissionsForCamera(cameraId, clientPid, clientUid);
     if (callingPid != getpid() &&
                 (deviceKind != SystemCameraKind::SYSTEM_ONLY_CAMERA) && !checkPermissionForCamera) {
         ALOGE("Permission Denial: can't use the camera pid=%d, uid=%d", clientPid, clientUid);
@@ -1906,8 +1844,9 @@
         // If the System User tries to access the camera when the device is running in
         // headless system user mode, ensure that client has the required permission
         // CAMERA_HEADLESS_SYSTEM_USER.
-        if (isHeadlessSystemUserMode() && (clientUserId == USER_SYSTEM) &&
-                !hasPermissionsForCameraHeadlessSystemUser(cameraId, callingPid, callingUid)) {
+        if (mAttributionAndPermissionUtils->isHeadlessSystemUserMode()
+                && (clientUserId == USER_SYSTEM)
+                && !hasPermissionsForCameraHeadlessSystemUser(cameraId, callingPid, callingUid)) {
             ALOGE("Permission Denial: can't use the camera pid=%d, uid=%d", clientPid, clientUid);
             return STATUS_ERROR_FMT(ERROR_PERMISSION_DENIED,
                     "Caller \"%s\" (PID %d, UID %d) cannot open camera \"%s\" as Headless System \
@@ -2273,7 +2212,7 @@
     }
 
     // (1) Cameraserver trying to connect, accept.
-    if (CameraThreadState::getCallingPid() == getpid()) {
+    if (mAttributionAndPermissionUtils->isCallerCameraServerNotDelegating()) {
         return false;
     }
     // (2)
@@ -3323,22 +3262,6 @@
     return Status::ok();
 }
 
-bool CameraService::hasCameraPermissions() const {
-    int callingPid = CameraThreadState::getCallingPid();
-    int callingUid = CameraThreadState::getCallingUid();
-    AttributionSourceState attributionSource{};
-    attributionSource.pid = callingPid;
-    attributionSource.uid = callingUid;
-    bool res = checkPermission(std::string(), sCameraPermission,
-            attributionSource, std::string(), AppOpsManager::OP_NONE);
-
-    bool hasPermission = ((callingPid == getpid()) || res);
-    if (!hasPermission) {
-        ALOGE("%s: pid %d doesn't have camera permissions", __FUNCTION__, callingPid);
-    }
-    return hasPermission;
-}
-
 Status CameraService::isConcurrentSessionConfigurationSupported(
         const std::vector<CameraIdAndSessionConfiguration>& cameraIdsAndSessionConfigurations,
         int targetSdkVersion, /*out*/bool* isSupported) {
@@ -3354,7 +3277,11 @@
     }
 
     // Check for camera permissions
-    if (!hasCameraPermissions()) {
+    int callingPid = CameraThreadState::getCallingPid();
+    int callingUid = CameraThreadState::getCallingUid();
+    bool hasCameraPermission = ((callingPid == getpid()) ||
+            hasPermissionsForCamera(callingPid, callingUid));
+    if (!hasCameraPermission) {
         return STATUS_ERROR(ERROR_PERMISSION_DENIED,
                 "android.permission.CAMERA needed to call"
                 "isConcurrentSessionConfigurationSupported");
@@ -3398,15 +3325,9 @@
         return STATUS_ERROR(ERROR_ILLEGAL_ARGUMENT, "Null listener given to addListener");
     }
 
-    auto clientUid = CameraThreadState::getCallingUid();
     auto clientPid = CameraThreadState::getCallingPid();
-    AttributionSourceState attributionSource{};
-    attributionSource.uid = clientUid;
-    attributionSource.pid = clientPid;
-
-   bool openCloseCallbackAllowed = checkPermission(std::string(),
-            sCameraOpenCloseListenerPermission, attributionSource, std::string(),
-            AppOpsManager::OP_NONE);
+    auto clientUid = CameraThreadState::getCallingUid();
+    bool openCloseCallbackAllowed = hasPermissionsForOpenCloseListener(clientPid, clientUid);
 
     Mutex::Autolock lock(mServiceLock);
 
@@ -4049,6 +3970,7 @@
 
 CameraService::Client::Client(const sp<CameraService>& cameraService,
         const sp<ICameraClient>& cameraClient,
+        std::shared_ptr<AttributionAndPermissionUtils> attributionAndPermissionUtils,
         const std::string& clientPackageName, bool systemNativeClient,
         const std::optional<std::string>& clientFeatureId,
         const std::string& cameraIdStr,
@@ -4057,6 +3979,7 @@
         int servicePid, bool overrideToPortrait) :
         CameraService::BasicClient(cameraService,
                 IInterface::asBinder(cameraClient),
+                attributionAndPermissionUtils,
                 clientPackageName, systemNativeClient, clientFeatureId,
                 cameraIdStr, cameraFacing, sensorOrientation,
                 clientPid, clientUid,
@@ -4087,10 +4010,12 @@
 
 CameraService::BasicClient::BasicClient(const sp<CameraService>& cameraService,
         const sp<IBinder>& remoteCallback,
+        std::shared_ptr<AttributionAndPermissionUtils> attributionAndPermissionUtils,
         const std::string& clientPackageName, bool nativeClient,
         const std::optional<std::string>& clientFeatureId, const std::string& cameraIdStr,
         int cameraFacing, int sensorOrientation, int clientPid, uid_t clientUid,
         int servicePid, bool overrideToPortrait):
+        mAttributionAndPermissionUtils(attributionAndPermissionUtils),
         mDestructionStarted(false),
         mCameraIdStr(cameraIdStr), mCameraFacing(cameraFacing), mOrientation(sensorOrientation),
         mClientPackageName(clientPackageName), mSystemNativeClient(nativeClient),
@@ -4123,7 +4048,7 @@
         mAppOpsManager = std::make_unique<AppOpsManager>();
     }
 
-    mUidIsTrusted = isTrustedCallingUid(mClientUid);
+    mUidIsTrusted = mAttributionAndPermissionUtils->isTrustedCallingUid(mClientUid);
 }
 
 CameraService::BasicClient::~BasicClient() {
@@ -4862,7 +4787,7 @@
     }
     hasCameraPrivacyFeature(); // Called so the result is cached
     mSpm.addSensorPrivacyListener(this);
-    if (isAutomotiveDevice()) {
+    if (mAttributionAndPermissionUtils->isAutomotiveDevice()) {
         mSpm.addToggleSensorPrivacyListener(this);
     }
     mSensorPrivacyEnabled = mSpm.isSensorPrivacyEnabled();
@@ -4902,7 +4827,7 @@
 void CameraService::SensorPrivacyPolicy::unregisterSelf() {
     Mutex::Autolock _l(mSensorPrivacyLock);
     mSpm.removeSensorPrivacyListener(this);
-    if (isAutomotiveDevice()) {
+    if (mAttributionAndPermissionUtils->isAutomotiveDevice()) {
         mSpm.removeToggleSensorPrivacyListener(this);
     }
     mSpm.unlinkToDeath(this);