From f91b0237fe576b797c82e62bcbf50291fdb11e72 Mon Sep 17 00:00:00 2001
From: junyulai <junyulai@google.com>
Date: Tue, 18 Aug 2020 18:50:13 +0800
Subject: [PATCH] Skip RAT type listener registration if IMSI is not available

Currently, if SIM is inserted but IMSI is not available, such
as SIM PIN locked state. Information of such SIM will still
be available but IMSI is not. Which makes
NetworkStatsSubscriptionMonitor failed to store IMSI locally
for later RAT type query. Hence, NETWORK_TYPE_UNKNOWN is
always returned for such SIM.

Skip the registration until the IMSI is available. This is safe
since there will be another onSubscriptionsChanged event when
that happens.

Test: enable SIM PIN and manually test
Test: atest NetworkStatsSubscriptionsMonitorTest#testSubscriberIdUnavailable
Test: ./out/host/linux-x86/bin/statsd_testdrive 10082
Bug: 160941101
Merged-In: I408379b3c432d9e62e0837d6b4f6551cc7838e29
Change-Id: I408379b3c432d9e62e0837d6b4f6551cc7838e29
(cherry-picked from ag/12400327)
---
 .../NetworkStatsSubscriptionsMonitorTest.java | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/tests/net/java/com/android/server/net/NetworkStatsSubscriptionsMonitorTest.java b/tests/net/java/com/android/server/net/NetworkStatsSubscriptionsMonitorTest.java
index 6dc4fced19..8f093779da 100644
--- a/tests/net/java/com/android/server/net/NetworkStatsSubscriptionsMonitorTest.java
+++ b/tests/net/java/com/android/server/net/NetworkStatsSubscriptionsMonitorTest.java
@@ -30,6 +30,7 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.content.Context;
 import android.net.NetworkTemplate;
 import android.os.test.TestLooper;
@@ -135,6 +136,11 @@ public final class NetworkStatsSubscriptionsMonitorTest {
         mMonitor.onSubscriptionsChanged();
     }
 
+    private void updateSubscriberIdForTestSub(int subId, @Nullable final String subscriberId) {
+        when(mTelephonyManager.getSubscriberId(subId)).thenReturn(subscriberId);
+        mMonitor.onSubscriptionsChanged();
+    }
+
     private void removeTestSub(int subId) {
         // Remove subId from TestSubList.
         mTestSubList.removeIf(it -> it == subId);
@@ -268,4 +274,54 @@ public final class NetworkStatsSubscriptionsMonitorTest {
         listener.onServiceStateChanged(serviceState);
         assertRatTypeNotChangedForSub(TEST_IMSI1, TelephonyManager.NETWORK_TYPE_NR);
     }
+
+    @Test
+    public void testSubscriberIdUnavailable() {
+        final ArgumentCaptor<RatTypeListener> ratTypeListenerCaptor =
+                ArgumentCaptor.forClass(RatTypeListener.class);
+
+        mMonitor.start();
+        // Insert sim1, set subscriberId to null which is normal in SIM PIN locked case.
+        // Verify RAT type is NETWORK_TYPE_UNKNOWN and service will not perform listener
+        // registration.
+        addTestSub(TEST_SUBID1, null);
+        verify(mTelephonyManager, never()).listen(any(), anyInt());
+        assertRatTypeNotChangedForSub(TEST_IMSI1, TelephonyManager.NETWORK_TYPE_UNKNOWN);
+
+        // Set IMSI for sim1, verify the listener will be registered.
+        updateSubscriberIdForTestSub(TEST_SUBID1, TEST_IMSI1);
+        verify(mTelephonyManager, times(1)).listen(ratTypeListenerCaptor.capture(),
+                eq(PhoneStateListener.LISTEN_SERVICE_STATE));
+        reset(mTelephonyManager);
+        when(mTelephonyManager.createForSubscriptionId(anyInt())).thenReturn(mTelephonyManager);
+
+        // Set RAT type of sim1 to UMTS. Verify RAT type of sim1 is changed.
+        setRatTypeForSub(ratTypeListenerCaptor.getAllValues(), TEST_SUBID1,
+                TelephonyManager.NETWORK_TYPE_UMTS);
+        assertRatTypeChangedForSub(TEST_IMSI1, TelephonyManager.NETWORK_TYPE_UMTS);
+        reset(mDelegate);
+
+        // Set IMSI to null again to simulate somehow IMSI is not available, such as
+        // modem crash. Verify service should not unregister listener.
+        updateSubscriberIdForTestSub(TEST_SUBID1, null);
+        verify(mTelephonyManager, never()).listen(any(), anyInt());
+        assertRatTypeNotChangedForSub(TEST_IMSI1, TelephonyManager.NETWORK_TYPE_UMTS);
+        reset(mDelegate);
+
+        // Set RAT type of sim1 to LTE. Verify RAT type of sim1 is still changed even if the IMSI
+        // is not available. The monitor keeps the listener even if the IMSI disappears because
+        // the IMSI can never change for any given subId, therefore even if the IMSI is updated
+        // to null, the monitor should continue accepting updates of the RAT type. However,
+        // telephony is never actually supposed to do this, if the IMSI disappears there should
+        // not be updates, but it's still the right thing to do theoretically.
+        setRatTypeForSub(ratTypeListenerCaptor.getAllValues(), TEST_SUBID1,
+                TelephonyManager.NETWORK_TYPE_LTE);
+        assertRatTypeChangedForSub(TEST_IMSI1, TelephonyManager.NETWORK_TYPE_LTE);
+        reset(mDelegate);
+
+        mMonitor.stop();
+        verify(mTelephonyManager, times(1)).listen(eq(ratTypeListenerCaptor.getValue()),
+                eq(PhoneStateListener.LISTEN_NONE));
+        assertRatTypeChangedForSub(TEST_IMSI1, TelephonyManager.NETWORK_TYPE_UNKNOWN);
+    }
 }