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Commit 6a135107 authored by Remi NGUYEN VAN's avatar Remi NGUYEN VAN
Browse files

PackageWatchdog listens for NetworkStack failures 

In addition to the NetworkStack app monitoring, have PackageWatchdog
register an observer to NetworkStackClient to receive severe failure
notifications, and attempt a rollback if available.

The callback is registered in onPackagesReady(), which is called in the
boot sequence just before starting the NetworkStack.

Test: installed new networkstack, killed it twice, observe rollback
Test: unit test in change on top
Bug: 133725814
Change-Id: I2cb4200b78c2482cacc4bfe2ace1581b869be512
parent 5855ce28

services/core/java/com/android/server/PackageWatchdog.java

+48 −10
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ import android.annotation.Nullable; 
import android.content.Context;

import android.content.pm.PackageManager;

import android.content.pm.VersionedPackage;

import android.net.NetworkStackClient;

import android.os.Environment;

import android.os.Handler;

import android.os.Looper;
@@ -115,6 +116,7 @@ public class PackageWatchdog { 
    // File containing the XML data of monitored packages /data/system/package-watchdog.xml

    private final AtomicFile mPolicyFile;

    private final ExplicitHealthCheckController mHealthCheckController;

    private final NetworkStackClient mNetworkStackClient;

    @GuardedBy("mLock")

    private boolean mIsPackagesReady;

    // Flag to control whether explicit health checks are supported or not
@@ -135,7 +137,8 @@ public class PackageWatchdog { 
                        new File(new File(Environment.getDataDirectory(), "system"),

                                "package-watchdog.xml")),

                new Handler(Looper.myLooper()), BackgroundThread.getHandler(),

                new ExplicitHealthCheckController(context));

                new ExplicitHealthCheckController(context),

                NetworkStackClient.getInstance());

    }



    /**
@@ -143,12 +146,14 @@ public class PackageWatchdog { 
     */

    @VisibleForTesting

    PackageWatchdog(Context context, AtomicFile policyFile, Handler shortTaskHandler,

            Handler longTaskHandler, ExplicitHealthCheckController controller) {

            Handler longTaskHandler, ExplicitHealthCheckController controller,

            NetworkStackClient networkStackClient) {

        mContext = context;

        mPolicyFile = policyFile;

        mShortTaskHandler = shortTaskHandler;

        mLongTaskHandler = longTaskHandler;

        mHealthCheckController = controller;

        mNetworkStackClient = networkStackClient;

        loadFromFile();

    }
@@ -174,6 +179,7 @@ public class PackageWatchdog { 
                    () -> syncRequestsAsync());

            setPropertyChangedListenerLocked();

            updateConfigs();

            registerNetworkStackHealthListener();

        }

    }
@@ -630,29 +636,40 @@ public class PackageWatchdog { 
            synchronized (mLock) {

                PackageHealthObserver registeredObserver = observer.mRegisteredObserver;

                if (registeredObserver != null) {

                    PackageManager pm = mContext.getPackageManager();

                    Iterator<MonitoredPackage> it = failedPackages.iterator();

                    while (it.hasNext()) {

                        String failedPackage = it.next().getName();

                        long versionCode = 0;

                        Slog.i(TAG, "Explicit health check failed for package " + failedPackage);

                        try {

                            versionCode = pm.getPackageInfo(

                                    failedPackage, 0 /* flags */).getLongVersionCode();

                        } catch (PackageManager.NameNotFoundException e) {

                        VersionedPackage versionedPkg = getVersionedPackage(failedPackage);

                        if (versionedPkg == null) {

                            Slog.w(TAG, "Explicit health check failed but could not find package "

                                    + failedPackage);

                            // TODO(b/120598832): Skip. We only continue to pass tests for now since

                            // the tests don't install any packages

                            versionedPkg = new VersionedPackage(failedPackage, 0L);

                        }

                        registeredObserver.execute(

                                new VersionedPackage(failedPackage, versionCode));

                        registeredObserver.execute(versionedPkg);

                    }

                }

            }

        });

    }



    @Nullable

    private VersionedPackage getVersionedPackage(String packageName) {

        final PackageManager pm = mContext.getPackageManager();

        if (pm == null) {

            return null;

        }

        try {

            final long versionCode = pm.getPackageInfo(

                    packageName, 0 /* flags */).getLongVersionCode();

            return new VersionedPackage(packageName, versionCode);

        } catch (PackageManager.NameNotFoundException e) {

            return null;

        }

    }



    /**

     * Loads mAllObservers from file.

     *
@@ -726,6 +743,27 @@ public class PackageWatchdog { 
        }

    }



    private void registerNetworkStackHealthListener() {

        // TODO: have an internal method to trigger a rollback by reporting high severity errors,

        // and rely on ActivityManager to inform the watchdog of severe network stack crashes

        // instead of having this listener in parallel.

        mNetworkStackClient.registerHealthListener(

                packageName -> {

                    final VersionedPackage pkg = getVersionedPackage(packageName);

                    if (pkg == null) {

                        Slog.wtf(TAG, "NetworkStack failed but could not find its package");

                        return;

                    }

                    // This is a severe failure and recovery should be attempted immediately.

                    // TODO: have a better way to handle such failures.

                    final List<VersionedPackage> pkgList = Collections.singletonList(pkg);

                    final long failureCount = getTriggerFailureCount();

                    for (int i = 0; i < failureCount; i++) {

                        onPackageFailure(pkgList);

                    }

                });

    }



    /**

     * Persists mAllObservers to file. Threshold information is ignored.

     */

tests/PackageWatchdog/Android.bp

+7 −0
Original line number Diff line number Diff line
@@ -18,11 +18,18 @@ android_test { 
    srcs: ["src/**/*.java"],

    static_libs: [

        "junit",

        "mockito-target-extended-minus-junit4",

        "frameworks-base-testutils",

        "androidx.test.rules",

        "services.core",

        "services.net",

    ],

    libs: ["android.test.runner"],

    jni_libs: [

        // mockito-target-extended dependencies

        "libdexmakerjvmtiagent",

        "libstaticjvmtiagent",

    ],

    platform_apis: true,

    test_suites: ["device-tests"],

}

tests/PackageWatchdog/src/com/android/server/PackageWatchdogTest.java

+8 −1
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ import static org.junit.Assert.fail; 
import android.Manifest;

import android.content.Context;

import android.content.pm.VersionedPackage;

import android.net.NetworkStackClient;

import android.os.Handler;

import android.os.test.TestLooper;

import android.provider.DeviceConfig;
@@ -41,6 +42,8 @@ import com.android.server.PackageWatchdog.PackageHealthObserverImpact; 
import org.junit.After;

import org.junit.Before;

import org.junit.Test;

import org.mockito.Mock;

import org.mockito.MockitoAnnotations;



import java.io.File;

import java.util.ArrayList;
@@ -70,9 +73,12 @@ public class PackageWatchdogTest { 
    private static final long SHORT_DURATION = TimeUnit.SECONDS.toMillis(1);

    private static final long LONG_DURATION = TimeUnit.SECONDS.toMillis(5);

    private TestLooper mTestLooper;

    @Mock

    private NetworkStackClient mNetworkStackClient;



    @Before

    public void setUp() throws Exception {

        MockitoAnnotations.initMocks(this);

        new File(InstrumentationRegistry.getContext().getFilesDir(),

                "package-watchdog.xml").delete();

        adoptShellPermissions(Manifest.permission.READ_DEVICE_CONFIG);
@@ -732,7 +738,8 @@ public class PackageWatchdogTest { 
                new AtomicFile(new File(context.getFilesDir(), "package-watchdog.xml"));

        Handler handler = new Handler(mTestLooper.getLooper());

        PackageWatchdog watchdog =

                new PackageWatchdog(context, policyFile, handler, handler, controller);

                new PackageWatchdog(context, policyFile, handler, handler, controller,

                        mNetworkStackClient);

        // Verify controller is not automatically started

        assertFalse(controller.mIsEnabled);

        if (withPackagesReady) {