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Commit a929cf01 authored by Nikita Ioffe's avatar Nikita Ioffe
Browse files

Add Binder.getCallingUidOrThrow method 

Binder.getCallingUidOrThrow is a pure java method which uses
Binder.isHandlingTransaction @CriticalNative method.

Binder.isHandlingTransaction itself is not exposed a public API.

Bug: 62253865
Fix: 62253865
Test: Added a testcase to BinderTest.java to verify ISE is thrown
Change-Id: I93a1b6c24a4747b8b70c32d291b4706b6159a3d0
parent 424fc04c

api/current.txt

+1 −0
Original line number Diff line number Diff line
@@ -33698,6 +33698,7 @@ 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

+24 −0
Original line number Diff line number Diff line
@@ -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

+7 −0
Original line number Diff line number Diff line
@@ -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

+9 −0
Original line number Diff line number Diff line
@@ -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) {

        }

    }

}