Add NetworkStack app

//

// 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.

//

// Library including the network stack, used to compile the network stack app, or linked into the

// system server on devices that run the stack there

java_library {

    name: "NetworkStackLib",

    installable: true,

    srcs: [

        "src/**/*.java",

    ],

}

// Updatable network stack packaged as an application

android_app {

    name: "NetworkStack",

    platform_apis: true,

    certificate: "platform",

    privileged: true,

    static_libs: [

        "NetworkStackLib"

    ],

    manifest: "AndroidManifest.xml",

}

 No newline at end of file

<?xml version="1.0" encoding="utf-8"?>

<!--

/*

 * Copyright (C) 2014 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.

 */

-->

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

          package="com.google.android.networkstack"

          android:sharedUserId="android.uid.networkstack">

    <uses-permission android:name="android.permission.INTERNET" />

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

    <!-- Launch captive portal app as specific user -->

    <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS_FULL" />

    <application

        android:label="NetworkStack"

        android:defaultToDeviceProtectedStorage="true"

        android:directBootAware="true"

        android:usesCleartextTraffic="true">

        <service android:name="com.android.server.NetworkStackService">

            <intent-filter>

                <action android:name="android.net.INetworkStackConnector"/>

            </intent-filter>

        </service>

    </application>

</manifest>

/*

 * 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;

import static android.os.Binder.getCallingUid;

import android.annotation.NonNull;

import android.annotation.Nullable;

import android.app.Service;

import android.content.Intent;

import android.net.INetworkStackConnector;

import android.os.IBinder;

import android.os.Process;

import java.io.FileDescriptor;

import java.io.PrintWriter;

/**

 * Android service used to start the network stack when bound to via an intent.

 *

 * <p>The service returns a binder for the system server to communicate with the network stack.

 */

public class NetworkStackService extends Service {

    private static final String TAG = NetworkStackService.class.getSimpleName();

    /**

     * Create a binder connector for the system server to communicate with the network stack.

     *

     * <p>On platforms where the network stack runs in the system server process, this method may

     * be called directly instead of obtaining the connector by binding to the service.

     */

    public static IBinder makeConnector() {

        return new NetworkStackConnector();

    }

    @NonNull

    @Override

    public IBinder onBind(Intent intent) {

        return makeConnector();

    }

    private static class NetworkStackConnector extends INetworkStackConnector.Stub {

        // TODO: makeDhcpServer(), etc. will go here.

        @Override

        protected void dump(@NonNull FileDescriptor fd, @NonNull PrintWriter fout,

                @Nullable String[] args) {

            checkCaller();

            fout.println("NetworkStack logs:");

            // TODO: dump logs here

        }

    }

    private static void checkCaller() {

        // TODO: check that the calling PID is the system server.

        if (getCallingUid() != Process.SYSTEM_UID && getCallingUid() != Process.ROOT_UID) {

            throw new SecurityException("Invalid caller: " + getCallingUid());

        }

    }

}