New receiver for signed config.

A new receiver is added when the system server is created. It receives
broadcasts and pulls out the config & signature, but doesn't yet do
anything with it.

go/serverless-config-design
Test: Manual
Bug: 110509075

Change-Id: Ie369e198de5e830253b17e964afb67c76735909c

services/core/java/com/android/server/signedconfig/SignedConfigApplicator.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2018 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.server.signedconfig;
+
+import android.content.Context;
+
+class SignedConfigApplicator {
+
+    static void applyConfig(Context context, String config, String signature) {
+        //TODO verify signature
+        //TODO parse & apply config
+    }
+
+}

services/core/java/com/android/server/signedconfig/SignedConfigService.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2018 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.server.signedconfig;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManagerInternal;
+import android.net.Uri;
+import android.os.Bundle;
+import android.util.Slog;
+
+import com.android.server.LocalServices;
+
+/**
+ * Signed config service. This is not an Android Service, but just owns a broadcast receiver for
+ * receiving package install and update notifications from the package manager.
+ */
+public class SignedConfigService {
+
+    private static final boolean DBG = false;
+    private static final String TAG = "SignedConfig";
+
+    // TODO should these be elsewhere? In a public API?
+    private static final String KEY_CONFIG = "android.signedconfig";
+    private static final String KEY_CONFIG_SIGNATURE = "android.signedconfig.signature";
+
+    private static class UpdateReceiver extends BroadcastReceiver {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            new SignedConfigService(context).handlePackageBroadcast(intent);
+        }
+    }
+
+    private final Context mContext;
+    private final PackageManagerInternal mPacMan;
+
+    public SignedConfigService(Context context) {
+        mContext = context;
+        mPacMan = LocalServices.getService(PackageManagerInternal.class);
+    }
+
+    void handlePackageBroadcast(Intent intent) {
+        if (DBG) Slog.d(TAG, "handlePackageBroadcast " + intent);
+        Uri packageData = intent.getData();
+        String packageName = packageData == null ? null : packageData.getSchemeSpecificPart();
+        if (DBG) Slog.d(TAG, "handlePackageBroadcast package=" + packageName);
+        if (packageName == null) {
+            return;
+        }
+        int userId = mContext.getUser().getIdentifier();
+        PackageInfo pi = mPacMan.getPackageInfo(packageName, PackageManager.GET_META_DATA,
+                android.os.Process.SYSTEM_UID, userId);
+        if (pi == null) {
+            Slog.w(TAG, "Got null PackageInfo for " + packageName + "; user " + userId);
+            return;
+        }
+        Bundle metaData = pi.applicationInfo.metaData;
+        if (metaData == null) {
+            if (DBG) Slog.d(TAG, "handlePackageBroadcast: no metadata");
+            return;
+        }
+        if (metaData.containsKey(KEY_CONFIG)
+                && metaData.containsKey(KEY_CONFIG_SIGNATURE)) {
+            String config = metaData.getString(KEY_CONFIG);
+            String signature = metaData.getString(KEY_CONFIG_SIGNATURE);
+            if (DBG) {
+                Slog.d(TAG, "Got signed config: " + config);
+                Slog.d(TAG, "Got config signature: " + signature);
+            }
+            SignedConfigApplicator.applyConfig(mContext, config, signature);
+        } else {
+            if (DBG) Slog.d(TAG, "Package has no config/signature.");
+        }
+    }
+
+    /**
+     * Register to receive broadcasts from the package manager.
+     */
+    public static void registerUpdateReceiver(Context context) {
+        if (DBG) Slog.d(TAG, "Registering receiver");
+        IntentFilter filter = new IntentFilter();
+        filter.addAction(Intent.ACTION_PACKAGE_ADDED);
+        filter.addAction(Intent.ACTION_PACKAGE_REPLACED);
+        filter.addDataScheme("package");
+        context.registerReceiver(new UpdateReceiver(), filter);
+    }
+}

services/java/com/android/server/SystemServer.java

@@ -121,6 +121,7 @@ import com.android.server.restrictions.RestrictionsManagerService;
 import com.android.server.role.RoleManagerService;
 import com.android.server.security.KeyAttestationApplicationIdProviderService;
 import com.android.server.security.KeyChainSystemService;
+import com.android.server.signedconfig.SignedConfigService;
 import com.android.server.soundtrigger.SoundTriggerService;
 import com.android.server.stats.StatsCompanionService;
 import com.android.server.statusbar.StatusBarManagerService;
@@ -1003,6 +1004,11 @@ public final class SystemServer {
             traceBeginAndSlog("PinnerService");
             mSystemServiceManager.startService(PinnerService.class);
             traceEnd();
+
+            traceBeginAndSlog("SignedConfigService");
+            SignedConfigService.registerUpdateReceiver(mSystemContext);
+            traceEnd();
+
         } catch (RuntimeException e) {
             Slog.e("System", "******************************************");
             Slog.e("System", "************ Failure starting core service", e);