Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6b046e87 authored by Beatrice Marchegiani's avatar Beatrice Marchegiani
Browse files

Fix downgrade wallpaper restore bug 

Add a check in TarBackupReader to enable the restore of packages in the V_To_U_Allowlist in the V to U downgrade scenario

Bug: 341732443
Test: atest -v TarBackupReaderTest, manual test (details: https://b.corp.google.com/issues/341732443#comment18)
Change-Id: I12a1f272b17a12abb532a98c0d93f0a9854fcb51
parent 9800d7c2

services/backup/java/com/android/server/backup/restore/FullRestoreEngine.java

+2 −1
Original line number Diff line number Diff line
@@ -270,7 +270,8 @@ public class FullRestoreEngine extends RestoreEngine { 
                            PackageManagerInternal.class);

                    RestorePolicy restorePolicy = tarBackupReader.chooseRestorePolicy(

                            mBackupManagerService.getPackageManager(), allowApks, info, signatures,

                            pmi, mUserId, mBackupEligibilityRules);

                            pmi, mUserId, mBackupEligibilityRules,

                            mBackupManagerService.getContext());

                    mManifestSignatures.put(info.packageName, signatures);

                    mPackagePolicies.put(pkg, restorePolicy);

                    mPackageInstallers.put(pkg, info.installerPackageName);

services/backup/java/com/android/server/backup/utils/TarBackupReader.java

+49 −2
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_FULL_RESTORE_ 
import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_MISSING_SIGNATURE;

import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_RESTORE_ANY_VERSION;

import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_SYSTEM_APP_NO_AGENT;

import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_V_TO_U_RESTORE_PKG_ELIGIBLE;

import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_VERSIONS_MATCH;

import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_VERSION_OF_BACKUP_OLDER;
@@ -53,17 +54,22 @@ import android.content.pm.PackageInfo; 
import android.content.pm.PackageManager;

import android.content.pm.PackageManagerInternal;

import android.content.pm.Signature;

import android.os.Build;

import android.os.Bundle;

import android.os.UserHandle;

import android.provider.Settings;

import android.util.Slog;



import com.android.server.backup.FileMetadata;

import com.android.server.backup.Flags;

import com.android.server.backup.restore.RestorePolicy;



import java.io.ByteArrayInputStream;

import java.io.DataInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.util.Arrays;

import java.util.List;



/**

 * Utility methods to read backup tar file.
@@ -390,7 +396,7 @@ public class TarBackupReader { 
            boolean allowApks, FileMetadata info, Signature[] signatures,

            PackageManagerInternal pmi, int userId, Context context) {

        return chooseRestorePolicy(packageManager, allowApks, info, signatures, pmi, userId,

                BackupEligibilityRules.forBackup(packageManager, pmi, userId, context));

                BackupEligibilityRules.forBackup(packageManager, pmi, userId, context), context);

    }



    /**
@@ -406,7 +412,8 @@ public class TarBackupReader { 
     */

    public RestorePolicy chooseRestorePolicy(PackageManager packageManager,

            boolean allowApks, FileMetadata info, Signature[] signatures,

            PackageManagerInternal pmi, int userId, BackupEligibilityRules eligibilityRules) {

            PackageManagerInternal pmi, int userId, BackupEligibilityRules eligibilityRules,

            Context context) {

        if (signatures == null) {

            return RestorePolicy.IGNORE;

        }
@@ -448,6 +455,16 @@ public class TarBackupReader { 
                                    pkgInfo,

                                    LOG_EVENT_CATEGORY_BACKUP_MANAGER_POLICY,

                                    null);

                        } else if (isAllowlistedForVToURestore(info, pkgInfo, userId, context)) {

                            Slog.i(TAG, "Performing a V to U downgrade; package: "

                                            + info.packageName

                                            + " is allowlisted");

                            policy = RestorePolicy.ACCEPT;

                            mBackupManagerMonitorEventSender.monitorEvent(

                                    LOG_EVENT_ID_V_TO_U_RESTORE_PKG_ELIGIBLE,

                                    pkgInfo,

                                    LOG_EVENT_CATEGORY_BACKUP_MANAGER_POLICY,

                                    null);

                        } else {

                            // The data is from a newer version of the app than

                            // is presently installed.  That means we can only
@@ -751,6 +768,36 @@ public class TarBackupReader { 
        return true;

    }



    // checks the sdk of the target/source device for a B&R operation.

    // system components can opt in of V->U restore via allowlist.

    @SuppressWarnings("AndroidFrameworkCompatChange")

    private boolean isAllowlistedForVToURestore(FileMetadata backupFileInfo,

            PackageInfo installedPackageInfo,

            int userId, Context context) {

        // We assume that the package version matches the sdk (e.g. version 35 means V).

        // This is true for most of the system components ( and it is specifically true for those

        // that are in the allowlist)

        // In order to check if this is a V to U transfer we check if the package version from the

        // backup is 35 and on the target is 34.

        // We don't need to check the  V to U denylist here since a package can only make it

        // to TarBackupReader if allowed and not denied (from PerformUnifiedRestoreTask)



        String vToUAllowlist = getVToUAllowlist(context, userId);

        List<String> mVToUAllowlist = Arrays.asList(vToUAllowlist.split(","));

        return Flags.enableVToURestoreForSystemComponentsInAllowlist()

                && (installedPackageInfo.getLongVersionCode()

                == Build.VERSION_CODES.UPSIDE_DOWN_CAKE)

                && (backupFileInfo.version > Build.VERSION_CODES.UPSIDE_DOWN_CAKE)

                && (mVToUAllowlist.contains(installedPackageInfo.packageName));

    }



    private String getVToUAllowlist(Context context, int userId) {

        return Settings.Secure.getStringForUser(

                context.getContentResolver(),

                Settings.Secure.V_TO_U_RESTORE_ALLOWLIST,

                userId);

    }



    private static long extractRadix(byte[] data, int offset, int maxChars, int radix)

            throws IOException {

        long value = 0;

services/tests/mockingservicestests/src/com/android/server/backup/utils/TarBackupReaderTest.java

+148 −1
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_RESTORE_ANY_V 
import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_SYSTEM_APP_NO_AGENT;

import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_VERSIONS_MATCH;

import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_VERSION_OF_BACKUP_OLDER;

import static android.app.backup.BackupManagerMonitor.LOG_EVENT_ID_V_TO_U_RESTORE_PKG_ELIGIBLE;



import static com.google.common.truth.Truth.assertThat;
@@ -42,17 +43,23 @@ import android.content.pm.PackageManagerInternal; 
import android.content.pm.Signature;

import android.content.pm.SigningDetails;

import android.content.pm.SigningInfo;

import android.os.Build;

import android.os.Bundle;

import android.os.Process;

import android.os.UserHandle;

import android.platform.test.annotations.Presubmit;

import android.platform.test.flag.junit.SetFlagsRule;

import android.provider.Settings;

import android.testing.TestableContext;



import androidx.test.InstrumentationRegistry;

import androidx.test.core.app.ApplicationProvider;

import androidx.test.filters.SmallTest;

import androidx.test.runner.AndroidJUnit4;



import com.android.frameworks.mockingservicestests.R;

import com.android.server.backup.FileMetadata;

import com.android.server.backup.Flags;

import com.android.server.backup.UserBackupManagerService;

import com.android.server.backup.restore.PerformAdbRestoreTask;

import com.android.server.backup.restore.RestorePolicy;
@@ -61,6 +68,7 @@ import com.android.server.backup.testutils.PackageManagerStub; 
import com.google.common.hash.Hashing;



import org.junit.Before;

import org.junit.Rule;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.mockito.ArgumentCaptor;
@@ -86,6 +94,8 @@ public class TarBackupReaderTest { 
    @Mock private BytesReadListener mBytesReadListenerMock;

    @Mock private IBackupManagerMonitor mBackupManagerMonitorMock;

    @Mock private PackageManagerInternal mMockPackageManagerInternal;

    @Rule

    public final SetFlagsRule mSetFlagsRule = new SetFlagsRule();



    private final PackageManagerStub mPackageManagerStub = new PackageManagerStub();

    private Context mContext;
@@ -95,7 +105,7 @@ public class TarBackupReaderTest { 
    public void setUp() throws Exception {

        MockitoAnnotations.initMocks(this);



        mContext = InstrumentationRegistry.getContext();

        mContext = new TestableContext(ApplicationProvider.getApplicationContext());

        mUserId = UserHandle.USER_SYSTEM;

    }
@@ -513,6 +523,107 @@ public class TarBackupReaderTest { 
                LOG_EVENT_ID_VERSIONS_MATCH);

    }



    @Test

    public void

    chooseRestorePolicy_flagOnNotRestoreAnyVersionVToURestoreAndInAllowlist_returnsIgnore()

            throws Exception {



        mSetFlagsRule.enableFlags(

                Flags.FLAG_ENABLE_V_TO_U_RESTORE_FOR_SYSTEM_COMPONENTS_IN_ALLOWLIST);



        TarBackupReader tarBackupReader = createTarBackupReader();



        Settings.Secure.putString(mContext.getContentResolver(),

                Settings.Secure.V_TO_U_RESTORE_ALLOWLIST, "test");



        Signature[] signatures = new Signature[]{FAKE_SIGNATURE_1};

        FileMetadata info = new FileMetadata();

        info.version = Build.VERSION_CODES.UPSIDE_DOWN_CAKE + 1;



        PackageInfo packageInfo = createNonRestoreAnyVersionUPackage();

        PackageManagerStub.sPackageInfo = packageInfo;



        doReturn(true).when(mMockPackageManagerInternal).isDataRestoreSafe(FAKE_SIGNATURE_1,

                packageInfo.packageName);

        RestorePolicy policy = tarBackupReader.chooseRestorePolicy(mPackageManagerStub,

                false /* allowApks */, info, signatures, mMockPackageManagerInternal,

                mUserId, mContext);



        assertThat(policy).isEqualTo(RestorePolicy.ACCEPT);

        ArgumentCaptor<Bundle> bundleCaptor = ArgumentCaptor.forClass(Bundle.class);

        verify(mBackupManagerMonitorMock).onEvent(bundleCaptor.capture());

        assertThat(bundleCaptor.getValue().get(EXTRA_LOG_EVENT_ID)).isEqualTo(

                LOG_EVENT_ID_V_TO_U_RESTORE_PKG_ELIGIBLE);

    }





    @Test

    public void

    chooseRestorePolicy_flagOffNotRestoreAnyVersionVToURestoreAndInAllowlist_returnsAccept()

            throws Exception {



        mSetFlagsRule.disableFlags(

                Flags.FLAG_ENABLE_V_TO_U_RESTORE_FOR_SYSTEM_COMPONENTS_IN_ALLOWLIST);



        TarBackupReader tarBackupReader = createTarBackupReader();



        Settings.Secure.putString(mContext.getContentResolver(),

                Settings.Secure.V_TO_U_RESTORE_ALLOWLIST, "test");



        Signature[] signatures = new Signature[]{FAKE_SIGNATURE_1};

        FileMetadata info = new FileMetadata();

        info.version = Build.VERSION_CODES.UPSIDE_DOWN_CAKE + 1;



        PackageInfo packageInfo = createNonRestoreAnyVersionUPackage();

        PackageManagerStub.sPackageInfo = packageInfo;



        doReturn(true).when(mMockPackageManagerInternal).isDataRestoreSafe(FAKE_SIGNATURE_1,

                packageInfo.packageName);

        RestorePolicy policy = tarBackupReader.chooseRestorePolicy(mPackageManagerStub,

                false /* allowApks */, info, signatures, mMockPackageManagerInternal,

                mUserId, mContext);



        assertThat(policy).isEqualTo(RestorePolicy.IGNORE);

        ArgumentCaptor<Bundle> bundleCaptor = ArgumentCaptor.forClass(Bundle.class);

        verify(mBackupManagerMonitorMock).onEvent(bundleCaptor.capture());

        assertThat(bundleCaptor.getValue().get(EXTRA_LOG_EVENT_ID)).isEqualTo(

                LOG_EVENT_ID_VERSION_OF_BACKUP_OLDER);



    }



    @Test

    public void

    chooseRestorePolicy_flagOnNotRestoreAnyVersionVToURestoreAndNotInAllowlist_returnsIgnore()

            throws Exception {



        mSetFlagsRule.enableFlags(

                Flags.FLAG_ENABLE_V_TO_U_RESTORE_FOR_SYSTEM_COMPONENTS_IN_ALLOWLIST);



        TarBackupReader tarBackupReader = createTarBackupReader();



        Settings.Secure.putString(mContext.getContentResolver(),

                Settings.Secure.V_TO_U_RESTORE_ALLOWLIST, "pkg");



        Signature[] signatures = new Signature[]{FAKE_SIGNATURE_1};

        FileMetadata info = new FileMetadata();

        info.version = Build.VERSION_CODES.UPSIDE_DOWN_CAKE + 1;



        PackageInfo packageInfo = createNonRestoreAnyVersionUPackage();

        PackageManagerStub.sPackageInfo = packageInfo;



        doReturn(true).when(mMockPackageManagerInternal).isDataRestoreSafe(FAKE_SIGNATURE_1,

                packageInfo.packageName);

        RestorePolicy policy = tarBackupReader.chooseRestorePolicy(mPackageManagerStub,

                false /* allowApks */, info, signatures, mMockPackageManagerInternal,

                mUserId, mContext);



        assertThat(policy).isEqualTo(RestorePolicy.IGNORE);

        ArgumentCaptor<Bundle> bundleCaptor = ArgumentCaptor.forClass(Bundle.class);

        verify(mBackupManagerMonitorMock).onEvent(bundleCaptor.capture());

        assertThat(bundleCaptor.getValue().get(EXTRA_LOG_EVENT_ID)).isEqualTo(

                LOG_EVENT_ID_VERSION_OF_BACKUP_OLDER);

    }



    @Test

    public void

    chooseRestorePolicy_notRestoreAnyVersionAndVersionMismatchButAllowApksAndHasApk_returnsAcceptIfApk()
@@ -523,6 +634,10 @@ public class TarBackupReaderTest { 
                inputStream, null);

        TarBackupReader tarBackupReader = new TarBackupReader(tarInputStream,

                mBytesReadListenerMock, mBackupManagerMonitorMock);



        Settings.Secure.putString(mContext.getContentResolver(),

                Settings.Secure.V_TO_U_RESTORE_ALLOWLIST, "pkg");



        Signature[] signatures = new Signature[]{FAKE_SIGNATURE_1};

        FileMetadata info = new FileMetadata();

        info.version = 2;
@@ -564,6 +679,10 @@ public class TarBackupReaderTest { 
                inputStream, null);

        TarBackupReader tarBackupReader = new TarBackupReader(tarInputStream,

                mBytesReadListenerMock, mBackupManagerMonitorMock);



        Settings.Secure.putString(mContext.getContentResolver(),

                Settings.Secure.V_TO_U_RESTORE_ALLOWLIST, "pkg");



        Signature[] signatures = new Signature[]{FAKE_SIGNATURE_1};

        FileMetadata info = new FileMetadata();

        info.version = 2;
@@ -596,5 +715,33 @@ public class TarBackupReaderTest { 
        assertThat(bundleCaptor.getValue().get(EXTRA_LOG_EVENT_ID)).isEqualTo(

                LOG_EVENT_ID_VERSION_OF_BACKUP_OLDER);

    }



    private TarBackupReader createTarBackupReader() throws Exception {

        InputStream inputStream = mContext.getResources().openRawResource(

                R.raw.backup_telephony_no_password);

        InputStream tarInputStream = PerformAdbRestoreTask.parseBackupFileHeaderAndReturnTarStream(

                inputStream, null);

        TarBackupReader tarBackupReader = new TarBackupReader(tarInputStream,

                mBytesReadListenerMock, mBackupManagerMonitorMock);

        return tarBackupReader;

    }



    private PackageInfo createNonRestoreAnyVersionUPackage(){

        PackageInfo packageInfo = new PackageInfo();

        packageInfo.packageName = "test";

        packageInfo.applicationInfo = new ApplicationInfo();

        packageInfo.applicationInfo.flags |= ApplicationInfo.FLAG_ALLOW_BACKUP;

        packageInfo.applicationInfo.flags &= ~ApplicationInfo.FLAG_RESTORE_ANY_VERSION;

        packageInfo.applicationInfo.uid = Process.FIRST_APPLICATION_UID;

        packageInfo.applicationInfo.backupAgentName = null;

        packageInfo.signingInfo = new SigningInfo(

                new SigningDetails(

                        new Signature[]{FAKE_SIGNATURE_1},

                        SigningDetails.SignatureSchemeVersion.SIGNING_BLOCK_V3,

                        null,

                        null));

        packageInfo.versionCode = Build.VERSION_CODES.UPSIDE_DOWN_CAKE;

        return packageInfo;

    }

}