Merge "Add Binder.getCallingUidOrThrow method"

api/current.txt

@@ -33707,6 +33707,7 @@ package android.os {
     method public static final void flushPendingCommands();
     method public static final int getCallingPid();
     method public static final int getCallingUid();
+    method public static final int getCallingUidOrThrow();
     method public static final android.os.UserHandle getCallingUserHandle();
     method public java.lang.String getInterfaceDescriptor();
     method public boolean isBinderAlive();

core/java/android/os/Binder.java

@@ -272,6 +272,30 @@ public class Binder implements IBinder {
     @CriticalNative
     public static final native int getCallingUid();
 
+    /**
+     * Returns {@code true} if the current thread is currently executing an
+     * incoming transaction.
+     *
+     * @hide
+     */
+    @CriticalNative
+    public static final native boolean isHandlingTransaction();
+
+    /**
+     * Return the Linux uid assigned to the process that sent the transaction
+     * currently being processed.
+     *
+     * @throws IllegalStateException if the current thread is not currently
+     *        executing an incoming transaction.
+     */
+    public static final int getCallingUidOrThrow() {
+        if (!isHandlingTransaction()) {
+            throw new IllegalStateException(
+                  "Thread is not in a binder transcation");
+        }
+        return getCallingUid();
+    }
+
     /**
      * Return the UserHandle assigned to the process that sent you the
      * current transaction that is being processed.  This is the user

core/jni/android_util_Binder.cpp

@@ -875,6 +875,11 @@ static jint android_os_Binder_getCallingUid()
     return IPCThreadState::self()->getCallingUid();
 }
 
+static jboolean android_os_Binder_isHandlingTransaction()
+{
+    return IPCThreadState::self()->isServingCall();
+}
+
 static jlong android_os_Binder_clearCallingIdentity()
 {
     return IPCThreadState::self()->clearCallingIdentity();
@@ -960,6 +965,8 @@ static const JNINativeMethod gBinderMethods[] = {
     // @CriticalNative
     { "getCallingUid", "()I", (void*)android_os_Binder_getCallingUid },
     // @CriticalNative
+    { "isHandlingTransaction", "()Z", (void*)android_os_Binder_isHandlingTransaction },
+    // @CriticalNative
     { "clearCallingIdentity", "()J", (void*)android_os_Binder_clearCallingIdentity },
     { "restoreCallingIdentity", "(J)V", (void*)android_os_Binder_restoreCallingIdentity },
     // @CriticalNative

core/tests/coretests/src/android/os/BinderTest.java

@@ -43,4 +43,13 @@ public class BinderTest extends TestCase {
         Binder.restoreCallingWorkSource(token);
         assertEquals(UID, Binder.getCallingWorkSourceUid());
     }
+
+    @SmallTest
+    public void testGetCallingUidOrThrow() throws Exception {
+        try {
+            Binder.getCallingUidOrThrow();
+            throw new AssertionError("IllegalStateException expected");
+        } catch (IllegalStateException expected) {
+        }
+    }
 }