Update audio permission checking
Change captureAudioOutputAllowed to check client pid.
Check calling uid with AID_AUDIOSERVER instead of calling pid with
own pid. This is consistent, and works if AudioFlinger and
AudioPolicyManager exist as different processes.
Remove getpid_cached since getpid() is very fast. This removes
any initialization issues.
Replace getuid() with AID_AUDIOSERVER to remove ambiguity of
multiple native audio services for multiple users. Only
one exists regardless of users.
Do not use multiuser UID checks for certain native services
that do not spawn for multiple users to prevent accidently exposure.
Move permission checks to use ServiceUtilities for control and
consistency.
Rename isTrustedCallingUid to isAudioServerOrMediaServerUid
so that permission check is explicitly known to caller.
Update MediaLogService to use ServiceUtilities.
Test: Basic sanity
Test: AudioTrackTest, AudioRecordTest, SoundPool, SoundTrigger
Bug: 79485140
Change-Id: Ib8ccb36929a9b4806c01626f32fa023a046d6020
diff --git a/media/utils/include/mediautils/ServiceUtilities.h b/media/utils/include/mediautils/ServiceUtilities.h
index 8ead410..2bdba5e 100644
--- a/media/utils/include/mediautils/ServiceUtilities.h
+++ b/media/utils/include/mediautils/ServiceUtilities.h
@@ -17,13 +17,49 @@
#include <unistd.h>
#include <binder/PermissionController.h>
+#include <cutils/multiuser.h>
+#include <private/android_filesystem_config.h>
namespace android {
// Audio permission utilities
-extern pid_t getpid_cached;
-bool isTrustedCallingUid(uid_t uid);
+// Used for calls that should originate from system services.
+// We allow that some services might have separate processes to
+// handle multiple users, e.g. u10_system, u10_bluetooth, u10_radio.
+static inline bool isServiceUid(uid_t uid) {
+ return multiuser_get_app_id(uid) < AID_APP_START;
+}
+
+// Used for calls that should originate from audioserver.
+static inline bool isAudioServerUid(uid_t uid) {
+ return uid == AID_AUDIOSERVER;
+}
+
+// Used for some permission checks.
+// AID_ROOT is OK for command-line tests. Native audioserver always OK.
+static inline bool isAudioServerOrRootUid(uid_t uid) {
+ return uid == AID_AUDIOSERVER || uid == AID_ROOT;
+}
+
+// Used for calls that should come from system server or internal.
+// Note: system server is multiprocess for multiple users. audioserver is not.
+static inline bool isAudioServerOrSystemServerUid(uid_t uid) {
+ return multiuser_get_app_id(uid) == AID_SYSTEM || uid == AID_AUDIOSERVER;
+}
+
+// Mediaserver may forward the client PID and UID as part of a binder interface call;
+// otherwise the calling UID must be equal to the client UID.
+static inline bool isAudioServerOrMediaServerUid(uid_t uid) {
+ switch (uid) {
+ case AID_MEDIA:
+ case AID_AUDIOSERVER:
+ return true;
+ default:
+ return false;
+ }
+}
+
bool recordingAllowed(const String16& opPackageName, pid_t pid, uid_t uid);
bool startRecording(const String16& opPackageName, pid_t pid, uid_t uid);
void finishRecording(const String16& opPackageName, uid_t uid);