[SM09] Add helper class to monitor RAT type change per sub
In current design, Rat type change in NSS is only for default
subscription. This is only correct for single sim project.
However, it does not correct for multi-sim scenarios such as
CBRS or DSDS, given that all data usage will be attributed
to the Rat type of default sub.
Thus, add a helper class to monitor subscription change event,
and register/unregister dynamically for Rat type change for
every subscription.
Note that unit test of the helper class will be addressed
in follow-up patch.
Test: m -j
Bug: 146415925
Change-Id: I0055f6b55c209a073ce997fc7a144477f9db7069
Merged-In: I0055f6b55c209a073ce997fc7a144477f9db7069
(cherry picked from commit 306de26c138ec135846f2a74a952464cf00dce54)
diff --git a/services/core/java/com/android/server/net/NetworkStatsSubscriptionsMonitor.java b/services/core/java/com/android/server/net/NetworkStatsSubscriptionsMonitor.java
new file mode 100644
index 0000000..0bdf3f2
--- /dev/null
+++ b/services/core/java/com/android/server/net/NetworkStatsSubscriptionsMonitor.java
@@ -0,0 +1,211 @@
+/*
+ * Copyright (C) 2020 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.net;
+
+import static android.net.NetworkTemplate.getCollapsedRatType;
+
+import android.annotation.NonNull;
+import android.content.Context;
+import android.telephony.Annotation;
+import android.telephony.PhoneStateListener;
+import android.telephony.ServiceState;
+import android.telephony.SubscriptionManager;
+import android.telephony.TelephonyManager;
+import android.text.TextUtils;
+import android.util.Log;
+
+import com.android.internal.util.CollectionUtils;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.Executor;
+
+/**
+ * Helper class that watches for events that are triggered per subscription.
+ */
+// TODO (b/152176562): Write tests to verify subscription changes generate corresponding
+// register/unregister calls.
+public class NetworkStatsSubscriptionsMonitor extends
+ SubscriptionManager.OnSubscriptionsChangedListener {
+
+ /**
+ * Interface that this monitor uses to delegate event handling to NetworkStatsService.
+ */
+ public interface Delegate {
+ /**
+ * Notify that the collapsed RAT type has been changed for any subscription. The method
+ * will also be triggered for any existing sub when start and stop monitoring.
+ *
+ * @param subscriberId IMSI of the subscription.
+ * @param collapsedRatType collapsed RAT type.
+ * @see android.net.NetworkTemplate#getCollapsedRatType(int).
+ */
+ void onCollapsedRatTypeChanged(@NonNull String subscriberId,
+ @Annotation.NetworkType int collapsedRatType);
+ }
+ private final Delegate mDelegate;
+
+ /**
+ * Receivers that watches for {@link ServiceState} changes for each subscription, to
+ * monitor the transitioning between Radio Access Technology(RAT) types for each sub.
+ */
+ @NonNull
+ private final CopyOnWriteArrayList<RatTypeListener> mRatListeners =
+ new CopyOnWriteArrayList<>();
+
+ @NonNull
+ private final SubscriptionManager mSubscriptionManager;
+ @NonNull
+ private final TelephonyManager mTeleManager;
+
+ @NonNull
+ private final Executor mExecutor;
+
+ NetworkStatsSubscriptionsMonitor(@NonNull Context context, @NonNull Executor executor,
+ @NonNull Delegate delegate) {
+ super();
+ mSubscriptionManager = (SubscriptionManager) context.getSystemService(
+ Context.TELEPHONY_SUBSCRIPTION_SERVICE);
+ mTeleManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
+ mExecutor = executor;
+ mDelegate = delegate;
+ }
+
+ @Override
+ public void onSubscriptionsChanged() {
+ // Collect active subId list, hidden subId such as opportunistic subscriptions are
+ // also needed to track CBRS.
+ final List<Integer> newSubs = getActiveSubIdList(mSubscriptionManager);
+
+ for (final int subId : newSubs) {
+ final RatTypeListener match = CollectionUtils.find(mRatListeners,
+ it -> it.mSubId == subId);
+ if (match != null) continue;
+
+ // Create listener for every newly added sub. Also store subscriberId into it to
+ // prevent binder call to telephony when querying RAT.
+ final String subscriberId = mTeleManager.getSubscriberId(subId);
+ if (TextUtils.isEmpty(subscriberId)) {
+ Log.wtf(NetworkStatsService.TAG,
+ "Empty subscriberId for newly added sub: " + subId);
+ }
+ final RatTypeListener listener =
+ new RatTypeListener(mExecutor, this, subId, subscriberId);
+ mRatListeners.add(listener);
+
+ // Register listener to the telephony manager that associated with specific sub.
+ mTeleManager.createForSubscriptionId(subId)
+ .listen(listener, PhoneStateListener.LISTEN_SERVICE_STATE);
+ }
+
+ for (final RatTypeListener listener : new ArrayList<>(mRatListeners)) {
+ // If the new list contains the subId of the listener, keeps it.
+ final Integer match = CollectionUtils.find(newSubs, it -> it == listener.mSubId);
+ if (match != null) continue;
+
+ handleRemoveRatTypeListener(listener);
+ }
+ }
+
+ @NonNull
+ private List<Integer> getActiveSubIdList(@NonNull SubscriptionManager subscriptionManager) {
+ final ArrayList<Integer> ret = new ArrayList<>();
+ final int[] ids = subscriptionManager.getCompleteActiveSubscriptionIdList();
+ for (int id : ids) ret.add(id);
+ return ret;
+ }
+
+ /**
+ * Get a collapsed RatType for the given subscriberId.
+ *
+ * @param subscriberId the target subscriberId
+ * @return collapsed RatType for the given subscriberId
+ */
+ public int getRatTypeForSubscriberId(@NonNull String subscriberId) {
+ final RatTypeListener match = CollectionUtils.find(mRatListeners,
+ it -> TextUtils.equals(subscriberId, it.mSubscriberId));
+ return match != null ? match.mLastCollapsedRatType : TelephonyManager.NETWORK_TYPE_UNKNOWN;
+ }
+
+ /**
+ * Start monitoring events that triggered per subscription.
+ */
+ public void start() {
+ mSubscriptionManager.addOnSubscriptionsChangedListener(mExecutor, this);
+ }
+
+ /**
+ * Unregister subscription changes and all listeners for each subscription.
+ */
+ public void stop() {
+ mSubscriptionManager.removeOnSubscriptionsChangedListener(this);
+
+ for (final RatTypeListener listener : new ArrayList<>(mRatListeners)) {
+ handleRemoveRatTypeListener(listener);
+ }
+ }
+
+ private void handleRemoveRatTypeListener(@NonNull RatTypeListener listener) {
+ mTeleManager.createForSubscriptionId(listener.mSubId)
+ .listen(listener, PhoneStateListener.LISTEN_NONE);
+ mRatListeners.remove(listener);
+
+ // Removal of subscriptions doesn't generate RAT changed event, fire it for every
+ // RatTypeListener.
+ mDelegate.onCollapsedRatTypeChanged(
+ listener.mSubscriberId, TelephonyManager.NETWORK_TYPE_UNKNOWN);
+ }
+
+ static class RatTypeListener extends PhoneStateListener {
+ // Unique id for the subscription. See {@link SubscriptionInfo#getSubscriptionId}.
+ @NonNull
+ private final int mSubId;
+
+ // IMSI to identifying the corresponding network from {@link NetworkState}.
+ // See {@link TelephonyManager#getSubscriberId}.
+ @NonNull
+ private final String mSubscriberId;
+
+ private volatile int mLastCollapsedRatType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
+ @NonNull
+ private final NetworkStatsSubscriptionsMonitor mMonitor;
+
+ RatTypeListener(@NonNull Executor executor,
+ @NonNull NetworkStatsSubscriptionsMonitor monitor, int subId,
+ @NonNull String subscriberId) {
+ super(executor);
+ mSubId = subId;
+ mSubscriberId = subscriberId;
+ mMonitor = monitor;
+ }
+
+ @Override
+ public void onServiceStateChanged(@NonNull ServiceState ss) {
+ final int networkType = ss.getDataNetworkType();
+ final int collapsedRatType = getCollapsedRatType(networkType);
+ if (collapsedRatType == mLastCollapsedRatType) return;
+
+ if (NetworkStatsService.LOGD) {
+ Log.d(NetworkStatsService.TAG, "subtype changed for sub(" + mSubId + "): "
+ + mLastCollapsedRatType + " -> " + collapsedRatType);
+ }
+ mLastCollapsedRatType = collapsedRatType;
+ mMonitor.mDelegate.onCollapsedRatTypeChanged(mSubscriberId, mLastCollapsedRatType);
+ }
+ }
+}