Implement a stub permission server for Brillo tier 1.

This will allow removing some existing hardcoded checks, like
https://cs.corp.google.com/android/frameworks/native/libs/binder/IServiceManager.cpp?l=70

Also add a .clang-format file for Android Framework C++ style.

Bug: 25663983
Change-Id: Icc4473a6f7b8c7395cdb167dc3fdbb2f076e5960
diff --git a/services/nativeperms/nativeperms.cpp b/services/nativeperms/nativeperms.cpp
new file mode 100644
index 0000000..7f03bed
--- /dev/null
+++ b/services/nativeperms/nativeperms.cpp
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2016 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 <base/at_exit.h>
+#include <base/logging.h>
+#include <base/message_loop/message_loop.h>
+#include <binder/IServiceManager.h>
+#include <binder/Status.h>
+#include <brillo/binder_watcher.h>
+#include <brillo/message_loops/base_message_loop.h>
+#include <brillo/syslog_logging.h>
+#include <utils/String16.h>
+
+#include "android/os/BnPermissionController.h"
+
+namespace {
+static android::String16 serviceName("permission");
+}
+
+namespace android {
+
+class PermissionService : public android::os::BnPermissionController {
+   public:
+    ::android::binder::Status checkPermission(
+            const ::android::String16& permission, int32_t pid, int32_t uid,
+            bool* _aidl_return) {
+        (void)permission;
+        (void)pid;
+        (void)uid;
+        *_aidl_return = true;
+        return binder::Status::ok();
+    }
+
+    ::android::binder::Status getPackagesForUid(
+            int32_t uid, ::std::vector<::android::String16>* _aidl_return) {
+        (void)uid;
+        // Brillo doesn't currently have installable packages.
+        if (_aidl_return) {
+            _aidl_return->clear();
+        }
+        return binder::Status::ok();
+    }
+
+    ::android::binder::Status isRuntimePermission(
+            const ::android::String16& permission, bool* _aidl_return) {
+        (void)permission;
+        // Brillo doesn't currently have runtime permissions.
+        *_aidl_return = false;
+        return binder::Status::ok();
+    }
+};
+
+}  // namespace android
+
+int main() {
+    base::AtExitManager atExitManager;
+    brillo::InitLog(brillo::kLogToSyslog);
+    // Register the service with servicemanager.
+    android::status_t status = android::defaultServiceManager()->addService(
+            serviceName, new android::PermissionService());
+    CHECK(status == android::OK) << "Failed to get IPermissionController "
+                                    "binder from servicemanager.";
+
+    // Create a message loop.
+    base::MessageLoopForIO messageLoopForIo;
+    brillo::BaseMessageLoop messageLoop{&messageLoopForIo};
+
+    // Initialize a binder watcher.
+    brillo::BinderWatcher watcher(&messageLoop);
+    watcher.Init();
+
+    // Run the message loop.
+    messageLoop.Run();
+}