WifiConfigManager: Handle file creation errors gracefully

If the user's CE directory is not accessible for some reason, all of the
user store file creation/read will fail. Handle these errors more
gracefully by checking for nulls in that path.

Note: If there are errors accessing the CE directory, any existing data
within the user store files will be lost. This CL does not attempt to
fix that.

Bug: 130366402
Test: Existing ACTS tests for config store.
Change-Id: I4c51b224e35e0d1b352359cd3be1dbbe2e66936f

3 files changed, 39 insertions, 11 deletions

diff --git a/service/java/com/android/server/wifi/WifiConfigManager.java b/service/java/com/android/server/wifi/WifiConfigManager.java
index 9332c5979..d649e6b10 100644
--- a/service/java/com/android/server/wifi/WifiConfigManager.java
+++ b/service/java/com/android/server/wifi/WifiConfigManager.java
@@ -3094,7 +3094,13 @@ public class WifiConfigManager {
         // configurations for the current user will also being loaded.
         if (mDeferredUserUnlockRead) {
             Log.i(TAG, "Handling user unlock before loading from store.");
-            mWifiConfigStore.setUserStores(WifiConfigStore.createUserFiles(mCurrentUserId));
+            List<WifiConfigStore.StoreFile> userStoreFiles =
+                    WifiConfigStore.createUserFiles(mCurrentUserId);
+            if (userStoreFiles == null) {
+                Log.wtf(TAG, "Failed to create user store files");
+                return false;
+            }
+            mWifiConfigStore.setUserStores(userStoreFiles);
             mDeferredUserUnlockRead = false;
         }
         try {
@@ -3125,9 +3131,15 @@ public class WifiConfigManager {
      * @param userId The identifier of the foreground user.
      * @return true on success, false otherwise.
      */
-    public boolean loadFromUserStoreAfterUnlockOrSwitch(int userId) {
+    private boolean loadFromUserStoreAfterUnlockOrSwitch(int userId) {
         try {
-            mWifiConfigStore.switchUserStoresAndRead(WifiConfigStore.createUserFiles(userId));
+            List<WifiConfigStore.StoreFile> userStoreFiles =
+                    WifiConfigStore.createUserFiles(userId);
+            if (userStoreFiles == null) {
+                Log.e(TAG, "Failed to create user store files");
+                return false;
+            }
+            mWifiConfigStore.switchUserStoresAndRead(userStoreFiles);
         } catch (IOException e) {
             Log.wtf(TAG, "Reading from new store failed. All saved private networks are lost!", e);
             return false;
diff --git a/service/java/com/android/server/wifi/WifiConfigStore.java b/service/java/com/android/server/wifi/WifiConfigStore.java
index ab7315f44..c7e75a5c4 100644
--- a/service/java/com/android/server/wifi/WifiConfigStore.java
+++ b/service/java/com/android/server/wifi/WifiConfigStore.java
@@ -55,6 +55,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.nio.charset.StandardCharsets;
 import java.security.DigestException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
@@ -267,7 +268,7 @@ public class WifiConfigStore {
      * @param fileId Identifier for the file. See {@link StoreFileId}.
      * @return new instance of the store file or null if the directory cannot be created.
      */
-    private static StoreFile createFile(File storeBaseDir, @StoreFileId int fileId) {
+    private static @Nullable StoreFile createFile(File storeBaseDir, @StoreFileId int fileId) {
         File storeDir = new File(storeBaseDir, STORE_DIRECTORY_NAME);
         if (!storeDir.exists()) {
             if (!storeDir.mkdir()) {
@@ -283,7 +284,7 @@ public class WifiConfigStore {
      *
      * @return new instance of the store file or null if the directory cannot be created.
      */
-    public static StoreFile createSharedFile() {
+    public static @Nullable StoreFile createSharedFile() {
         return createFile(Environment.getDataMiscDirectory(), STORE_FILE_SHARED_GENERAL);
     }
 
@@ -292,14 +293,19 @@ public class WifiConfigStore {
      * The user store file is inside the user's encrypted data directory.
      *
      * @param userId userId corresponding to the currently logged-in user.
-     * @return List of new instances of the store files created.
+     * @return List of new instances of the store files created or null if the directory cannot be
+     * created.
      */
-    public static List<StoreFile> createUserFiles(int userId) {
+    public static @Nullable List<StoreFile> createUserFiles(int userId) {
         List<StoreFile> storeFiles = new ArrayList<>();
-        storeFiles.add(createFile(Environment.getDataMiscCeDirectory(userId),
-                STORE_FILE_USER_GENERAL));
-        storeFiles.add(createFile(Environment.getDataMiscCeDirectory(userId),
-                STORE_FILE_USER_NETWORK_SUGGESTIONS));
+        for (int fileId : Arrays.asList(
+                STORE_FILE_USER_GENERAL, STORE_FILE_USER_NETWORK_SUGGESTIONS)) {
+            StoreFile storeFile = createFile(Environment.getDataMiscCeDirectory(userId), fileId);
+            if (storeFile == null) {
+                return null;
+            }
+            storeFiles.add(storeFile);
+        }
         return storeFiles;
     }
 
@@ -500,6 +506,7 @@ public class WifiConfigStore {
      */
     public void switchUserStoresAndRead(@NonNull List<StoreFile> userStores)
             throws XmlPullParserException, IOException {
+        Preconditions.checkNotNull(userStores);
         // Reset user store data.
         if (mUserStores != null) {
             for (StoreFile userStoreFile : mUserStores) {
diff --git a/tests/wifitests/src/com/android/server/wifi/WifiConfigManagerTest.java b/tests/wifitests/src/com/android/server/wifi/WifiConfigManagerTest.java
index d21808981..743ed6988 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiConfigManagerTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiConfigManagerTest.java
@@ -49,6 +49,7 @@ import android.util.Pair;
 
 import androidx.test.filters.SmallTest;
 
+import com.android.dx.mockito.inline.extended.ExtendedMockito;
 import com.android.internal.R;
 import com.android.server.wifi.util.WifiPermissionsUtil;
 import com.android.server.wifi.util.WifiPermissionsWrapper;
@@ -60,6 +61,7 @@ import org.mockito.ArgumentCaptor;
 import org.mockito.InOrder;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
+import org.mockito.MockitoSession;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
@@ -137,6 +139,7 @@ public class WifiConfigManagerTest {
     private TestLooper mLooper = new TestLooper();
     private ContentObserver mContentObserverPnoChannelCulling;
     private ContentObserver mContentObserverPnoRecencySorting;
+    private MockitoSession mSession;
 
     /**
      * Setup the mocks and an instance of WifiConfigManager before each test.
@@ -219,6 +222,11 @@ public class WifiConfigManagerTest {
                 Settings.Global.WIFI_PNO_RECENCY_SORTING_ENABLED)), eq(false),
                 observerCaptor.capture());
         mContentObserverPnoRecencySorting = observerCaptor.getValue();
+        // static mocking
+        mSession = ExtendedMockito.mockitoSession()
+                .mockStatic(WifiConfigStore.class, withSettings().lenient())
+                .startMocking();
+        when(WifiConfigStore.createUserFiles(anyInt())).thenReturn(mock(List.class));
     }
 
     /**
@@ -227,6 +235,7 @@ public class WifiConfigManagerTest {
     @After
     public void cleanup() {
         validateMockitoUsage();
+        mSession.finishMocking();
     }
 
     /**