Permission support for diagnostics.

This creates two permissions for access to diagnostic data:
 - DIAGNOSTIC_READ, for read-only access to live and freeze frame data;
 - DIAGNOSTIC_CLEAR, for deleting DTC data from the car.

It also extends the meaning of PERMISSION_VENDOR_EXTENSION to mean being allowed to read vendor-specific diagnostic sensor data.

Test: build
Bug: 35435164
For O-MR1.

Change-Id: I046bf6ae4a7aa2b2570ea5657bff9e1ce86edbce

1 files changed, 61 insertions, 0 deletions

diff --git a/car-lib/src/com/android/car/internal/CarPermission.java b/car-lib/src/com/android/car/internal/CarPermission.java
new file mode 100644
index 0000000000..0b3820f819
--- /dev/null
+++ b/car-lib/src/com/android/car/internal/CarPermission.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+package com.android.car.internal;
+
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.os.Binder;
+import android.os.Process;
+
+/**
+ * Represent an Android permission.
+ *
+ * @hide
+ */
+public class CarPermission {
+    private final Context mContext;
+    private final String mName;
+
+    /** @hide */
+    public CarPermission(Context context, String name) {
+        mContext = context;
+        mName = name;
+    }
+
+    /** @hide */
+    public boolean checkGranted() {
+        if (mName != null) {
+            if (Binder.getCallingUid() != Process.myUid()) {
+                return PackageManager.PERMISSION_GRANTED ==
+                        mContext.checkCallingOrSelfPermission(mName);
+            }
+        }
+        return true;
+    }
+
+    /** @hide */
+    public void assertGranted() {
+        if (checkGranted()) return;
+        throw new SecurityException(
+                "client does not have permission:"
+                        + mName
+                        + " pid:"
+                        + Binder.getCallingPid()
+                        + " uid:"
+                        + Binder.getCallingUid());
+    }
+}