SurfaceFlinger: Respect the PROTECTED gralloc bit.

This change makes SurfaceFlinger treat layers for which the active
buffer has the GRALLOC_USAGE_PROTECTED bit set as if they have the
'secure' flag set.

Change-Id: Ic60b6513a63e4bb92ec6ce9fd12fd39b4ba5f674
Bug: 4081304

libs/surfaceflinger_client/tests/Surface_test.cpp

@@ -15,22 +15,19 @@
  */
 
 #include <gtest/gtest.h>
+
+#include <binder/IMemory.h>
 #include <surfaceflinger/ISurfaceComposer.h>
 #include <surfaceflinger/Surface.h>
 #include <surfaceflinger/SurfaceComposerClient.h>
-
 #include <utils/String8.h>
 
 namespace android {
 
 class SurfaceTest : public ::testing::Test {
 protected:
-    virtual sp<SurfaceComposerClient> getSurfaceComposerClient() {
-        return sp<SurfaceComposerClient>(new SurfaceComposerClient);
-    }
-
     virtual void SetUp() {
-        mComposerClient = getSurfaceComposerClient();
+        mComposerClient = new SurfaceComposerClient;
         ASSERT_EQ(NO_ERROR, mComposerClient->initCheck());
 
         mSurfaceControl = mComposerClient->createSurface(getpid(),
@@ -77,4 +74,60 @@ TEST_F(SurfaceTest, QueuesToWindowComposerIsTrueWhenPurgatorized) {
     EXPECT_EQ(1, result);
 }
 
+// This test probably doesn't belong here.
+TEST_F(SurfaceTest, ScreenshotsOfProtectedBuffersFail) {
+    sp<ANativeWindow> anw(mSurface);
+
+    // Verify the screenshot works with no protected buffers.
+    sp<IMemoryHeap> heap;
+    uint32_t w=0, h=0;
+    PixelFormat fmt=0;
+    sp<ISurfaceComposer> sf(ComposerService::getComposerService());
+    ASSERT_EQ(NO_ERROR, sf->captureScreen(0, &heap, &w, &h, &fmt, 64, 64, 0,
+            40000));
+    ASSERT_TRUE(heap != NULL);
+
+    // Set the PROTECTED usage bit and verify that the screenshot fails.  Note
+    // that we need to dequeue a buffer in order for it to actually get
+    // allocated in SurfaceFlinger.
+    ASSERT_EQ(NO_ERROR, native_window_set_usage(anw.get(),
+            GRALLOC_USAGE_PROTECTED));
+    ASSERT_EQ(NO_ERROR, native_window_set_buffer_count(anw.get(), 3));
+    android_native_buffer_t* buf = 0;
+    for (int i = 0; i < 4; i++) {
+        // Loop to make sure SurfaceFlinger has retired a protected buffer.
+        ASSERT_EQ(NO_ERROR, anw->dequeueBuffer(anw.get(), &buf));
+        ASSERT_EQ(NO_ERROR, anw->lockBuffer(anw.get(), buf));
+        ASSERT_EQ(NO_ERROR, anw->queueBuffer(anw.get(), buf));
+    }
+    heap = 0;
+    w = h = fmt = 0;
+    ASSERT_EQ(INVALID_OPERATION, sf->captureScreen(0, &heap, &w, &h, &fmt,
+            64, 64, 0, 40000));
+    ASSERT_TRUE(heap == NULL);
+
+    // XXX: This should not be needed, but it seems that the new buffers don't
+    // correctly show up after the upcoming dequeue/lock/queue loop without it.
+    // We should look into this at some point.
+    ASSERT_EQ(NO_ERROR, native_window_set_buffer_count(anw.get(), 3));
+
+    // Un-set the PROTECTED usage bit and verify that the screenshot works
+    // again.  Note that we have to change the buffers geometry to ensure that
+    // the buffers get reallocated, as the new usage bits are a subset of the
+    // old.
+    ASSERT_EQ(NO_ERROR, native_window_set_usage(anw.get(), 0));
+    ASSERT_EQ(NO_ERROR, native_window_set_buffers_geometry(anw.get(), 32, 32, 0));
+    for (int i = 0; i < 4; i++) {
+        // Loop to make sure SurfaceFlinger has retired a protected buffer.
+        ASSERT_EQ(NO_ERROR, anw->dequeueBuffer(anw.get(), &buf));
+        ASSERT_EQ(NO_ERROR, anw->lockBuffer(anw.get(), buf));
+        ASSERT_EQ(NO_ERROR, anw->queueBuffer(anw.get(), buf));
+    }
+    heap = 0;
+    w = h = fmt = 0;
+    ASSERT_EQ(NO_ERROR, sf->captureScreen(0, &heap, &w, &h, &fmt, 64, 64, 0,
+            40000));
+    ASSERT_TRUE(heap != NULL);
+}
+
 }

services/surfaceflinger/Layer.cpp

@@ -57,7 +57,6 @@ Layer::Layer(SurfaceFlinger* flinger,
         mNeedsDithering(false),
         mSecure(false),
         mProtectedByApp(false),
-        mProtectedByDRM(false),
         mTextureManager(),
         mBufferManager(mTextureManager),
         mWidth(0), mHeight(0), mNeedsScaling(false), mFixedSize(false)
@@ -191,7 +190,6 @@ status_t Layer::setBuffers( uint32_t w, uint32_t h,
 
     mSecure = (flags & ISurfaceComposer::eSecure) ? true : false;
     mProtectedByApp = (flags & ISurfaceComposer::eProtectedByApp) ? true : false;
-    mProtectedByDRM = (flags & ISurfaceComposer::eProtectedByDRM) ? true : false;
     mNeedsBlending = (info.h_alpha - info.l_alpha) > 0 &&
             (flags & ISurfaceComposer::eOpaque) == 0;
 
@@ -392,6 +390,12 @@ bool Layer::needsFiltering() const
     return LayerBase::needsFiltering();
 }
 
+bool Layer::isProtected() const
+{
+    sp<GraphicBuffer> activeBuffer(mBufferManager.getActiveBuffer());
+    return (activeBuffer != 0) &&
+            (activeBuffer->getUsage() & GRALLOC_USAGE_PROTECTED);
+}
 
 status_t Layer::setBufferCount(int bufferCount)
 {
@@ -515,7 +519,7 @@ uint32_t Layer::getEffectiveUsage(uint32_t usage) const
         // request EGLImage for all buffers
         usage |= GraphicBuffer::USAGE_HW_TEXTURE;
     }
-    if (mProtectedByApp || mProtectedByDRM) {
+    if (mProtectedByApp) {
         // need a hardware-protected path to external video sink
         usage |= GraphicBuffer::USAGE_PROTECTED;
     }

services/surfaceflinger/Layer.h

@@ -80,8 +80,7 @@ public:
     virtual bool needsDithering() const     { return mNeedsDithering; }
     virtual bool needsFiltering() const;
     virtual bool isSecure() const           { return mSecure; }
-    virtual bool isProtectedByApp() const   { return mProtectedByApp; }
-    virtual bool isProtectedByDRM() const   { return mProtectedByDRM; }
+    virtual bool isProtected() const;
     virtual sp<Surface> createSurface() const;
     virtual status_t ditch();
     virtual void onRemoved();
@@ -222,7 +221,6 @@ private:
     // page-flip thread (currently main thread)
     bool mSecure;         // no screenshots
     bool mProtectedByApp; // application requires protected path to external sink
-    bool mProtectedByDRM; // DRM agent requires protected path to external sink
     Region mPostedDirtyRegion;
 
     // page-flip thread and transaction thread (currently main thread)

services/surfaceflinger/LayerBase.h

@@ -197,16 +197,10 @@ public:
     virtual bool isSecure() const       { return false; }
 
     /**
-     * isProtectedByApp - true if application says this surface is protected, that
-     * is if it requires a hardware-protected data path to an external sink.
+     * isProtected - true if the layer may contain protected content in the
+     * GRALLOC_USAGE_PROTECTED sense.
      */
-    virtual bool isProtectedByApp() const   { return false; }
-
-    /**
-     * isProtectedByDRM - true if DRM agent says this surface is protected, that
-     * is if it requires a hardware-protected data path to an external sink.
-     */
-    virtual bool isProtectedByDRM() const   { return false; }
+    virtual bool isProtected() const   { return false; }
 
     /** Called from the main thread, when the surface is removed from the
      * draw list */

services/surfaceflinger/SurfaceFlinger.cpp

@@ -2169,6 +2169,19 @@ status_t SurfaceFlinger::captureScreenImplLocked(DisplayID dpy,
     if (UNLIKELY(uint32_t(dpy) >= DISPLAY_COUNT))
         return BAD_VALUE;
 
+    // make sure none of the layers are protected
+    const Vector< sp<LayerBase> >& layers(mVisibleLayersSortedByZ);
+    const size_t count = layers.size();
+    for (size_t i=0 ; i<count ; ++i) {
+        const sp<LayerBase>& layer(layers[i]);
+        const uint32_t z = layer->drawingState().z;
+        if (z >= minLayerZ && z <= maxLayerZ) {
+            if (layer->isProtected()) {
+                return INVALID_OPERATION;
+            }
+        }
+    }
+
     if (!GLExtensions::getInstance().haveFramebufferObject())
         return INVALID_OPERATION;
 
@@ -2217,8 +2230,6 @@ status_t SurfaceFlinger::captureScreenImplLocked(DisplayID dpy,
         glClearColor(0,0,0,1);
         glClear(GL_COLOR_BUFFER_BIT);
 
-        const Vector< sp<LayerBase> >& layers(mVisibleLayersSortedByZ);
-        const size_t count = layers.size();
         for (size_t i=0 ; i<count ; ++i) {
             const sp<LayerBase>& layer(layers[i]);
             const uint32_t z = layer->drawingState().z;