Add mediadrm service

Part of media security hardening

This is an intermediate step toward moving
mediadrm to a new service separate from mediaserver.
This first step allows mediadrmservice to run based
on the system property media.mediadrmservice.enable
so it can be selectively enabled on devices that
support using native_handles for secure buffers.

bug: 22990512
Change-Id: I70320f0c4b7861cdba26fbc24c20bce54e5749a4
diff --git a/media/libmedia/IMediaDrmService.cpp b/media/libmedia/IMediaDrmService.cpp
new file mode 100644
index 0000000..9b6ecfd
--- /dev/null
+++ b/media/libmedia/IMediaDrmService.cpp
@@ -0,0 +1,88 @@
+/*
+**
+** Copyright 2015, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <binder/Parcel.h>
+#include <binder/IMemory.h>
+#include <media/ICrypto.h>
+#include <media/IDrm.h>
+#include <media/IMediaDrmService.h>
+
+#include <utils/Errors.h>  // for status_t
+#include <utils/String8.h>
+
+namespace android {
+
+enum {
+    MAKE_CRYPTO = IBinder::FIRST_CALL_TRANSACTION,
+    MAKE_DRM,
+};
+
+class BpMediaDrmService: public BpInterface<IMediaDrmService>
+{
+public:
+    BpMediaDrmService(const sp<IBinder>& impl)
+        : BpInterface<IMediaDrmService>(impl)
+    {
+    }
+
+    virtual sp<ICrypto> makeCrypto() {
+        Parcel data, reply;
+        data.writeInterfaceToken(IMediaDrmService::getInterfaceDescriptor());
+        remote()->transact(MAKE_CRYPTO, data, &reply);
+        return interface_cast<ICrypto>(reply.readStrongBinder());
+    }
+
+    virtual sp<IDrm> makeDrm() {
+        Parcel data, reply;
+        data.writeInterfaceToken(IMediaDrmService::getInterfaceDescriptor());
+        remote()->transact(MAKE_DRM, data, &reply);
+        return interface_cast<IDrm>(reply.readStrongBinder());
+    }
+
+};
+
+IMPLEMENT_META_INTERFACE(MediaDrmService, "android.media.IMediaDrmService");
+
+// ----------------------------------------------------------------------
+
+status_t BnMediaDrmService::onTransact(
+    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
+{
+    switch (code) {
+        case MAKE_CRYPTO: {
+            CHECK_INTERFACE(IMediaDrmService, data, reply);
+            sp<ICrypto> crypto = makeCrypto();
+            reply->writeStrongBinder(IInterface::asBinder(crypto));
+            return NO_ERROR;
+        } break;
+        case MAKE_DRM: {
+            CHECK_INTERFACE(IMediaDrmService, data, reply);
+            sp<IDrm> drm = makeDrm();
+            reply->writeStrongBinder(IInterface::asBinder(drm));
+            return NO_ERROR;
+        } break;
+        default:
+            return BBinder::onTransact(code, data, reply, flags);
+    }
+}
+
+// ----------------------------------------------------------------------------
+
+} // namespace android