Support disabling IPsec packet loss detector

Allow disabling detector for better configurability

Bug: 336638836
Test: atest FrameworksVcnTests(new tests) && atest CtsVcnTestCases
Flag: android.net.vcn.allow_disable_ipsec_loss_detector
Change-Id: Icd7183d12fb287399a500ea9c0ee4125c749275c

4 files changed, 86 insertions, 1 deletions

diff --git a/core/java/android/net/vcn/flags.aconfig b/core/java/android/net/vcn/flags.aconfig
index 6fde39852844..eca0e9372956 100644
--- a/core/java/android/net/vcn/flags.aconfig
+++ b/core/java/android/net/vcn/flags.aconfig
@@ -44,4 +44,14 @@ flag{
     metadata {
       purpose: PURPOSE_BUGFIX
     }
+}
+
+flag{
+    name: "allow_disable_ipsec_loss_detector"
+    namespace: "vcn"
+    description: "Allow disabling IPsec packet loss detector"
+    bug: "336638836"
+    metadata {
+      purpose: PURPOSE_BUGFIX
+    }
 }
\ No newline at end of file
diff --git a/services/core/java/com/android/server/vcn/routeselection/IpSecPacketLossDetector.java b/services/core/java/com/android/server/vcn/routeselection/IpSecPacketLossDetector.java
index 36192537493a..474253223628 100644
--- a/services/core/java/com/android/server/vcn/routeselection/IpSecPacketLossDetector.java
+++ b/services/core/java/com/android/server/vcn/routeselection/IpSecPacketLossDetector.java
@@ -115,6 +115,10 @@ public class IpSecPacketLossDetector extends NetworkMetricMonitor {
     // validation failure.
     private static final int IPSEC_PACKET_LOSS_PERCENT_THRESHOLD_DEFAULT = 12;
 
+    /** Carriers can disable the detector by setting the threshold to -1 */
+    @VisibleForTesting(visibility = Visibility.PRIVATE)
+    static final int IPSEC_PACKET_LOSS_PERCENT_THRESHOLD_DISABLE_DETECTOR = -1;
+
     private static final int POLL_IPSEC_STATE_INTERVAL_SECONDS_DEFAULT = 20;
 
     // By default, there's no maximum limit enforced
@@ -271,7 +275,10 @@ public class IpSecPacketLossDetector extends NetworkMetricMonitor {
         // When multiple parallel inbound transforms are created, NetworkMetricMonitor will be
         // enabled on the last one as a sample
         mInboundTransform = inboundTransform;
-        start();
+
+        if (!Flags.allowDisableIpsecLossDetector() || canStart()) {
+            start();
+        }
     }
 
     @Override
@@ -284,6 +291,14 @@ public class IpSecPacketLossDetector extends NetworkMetricMonitor {
             mPacketLossRatePercentThreshold = getPacketLossRatePercentThreshold(carrierConfig);
             mMaxSeqNumIncreasePerSecond = getMaxSeqNumIncreasePerSecond(carrierConfig);
         }
+
+        if (Flags.allowDisableIpsecLossDetector() && canStart() != isStarted()) {
+            if (canStart()) {
+                start();
+            } else {
+                stop();
+            }
+        }
     }
 
     @Override
@@ -298,6 +313,12 @@ public class IpSecPacketLossDetector extends NetworkMetricMonitor {
         mHandler.postDelayed(new PollIpSecStateRunnable(), mCancellationToken, 0L);
     }
 
+    private boolean canStart() {
+        return mInboundTransform != null
+                && mPacketLossRatePercentThreshold
+                        != IPSEC_PACKET_LOSS_PERCENT_THRESHOLD_DISABLE_DETECTOR;
+    }
+
     @Override
     protected void start() {
         super.start();
diff --git a/tests/vcn/java/com/android/server/vcn/routeselection/IpSecPacketLossDetectorTest.java b/tests/vcn/java/com/android/server/vcn/routeselection/IpSecPacketLossDetectorTest.java
index c8b60e5c335f..441a4ae6d9b6 100644
--- a/tests/vcn/java/com/android/server/vcn/routeselection/IpSecPacketLossDetectorTest.java
+++ b/tests/vcn/java/com/android/server/vcn/routeselection/IpSecPacketLossDetectorTest.java
@@ -20,6 +20,7 @@ import static android.net.vcn.VcnManager.VCN_NETWORK_SELECTION_IPSEC_PACKET_LOSS
 import static android.net.vcn.VcnManager.VCN_NETWORK_SELECTION_MAX_SEQ_NUM_INCREASE_PER_SECOND_KEY;
 import static android.net.vcn.VcnManager.VCN_NETWORK_SELECTION_POLL_IPSEC_STATE_INTERVAL_SECONDS_KEY;
 
+import static com.android.server.vcn.routeselection.IpSecPacketLossDetector.IPSEC_PACKET_LOSS_PERCENT_THRESHOLD_DISABLE_DETECTOR;
 import static com.android.server.vcn.routeselection.IpSecPacketLossDetector.MIN_VALID_EXPECTED_RX_PACKET_NUM;
 import static com.android.server.vcn.routeselection.IpSecPacketLossDetector.getMaxSeqNumIncreasePerSecond;
 import static com.android.server.vcn.util.PersistableBundleUtils.PersistableBundleWrapper;
@@ -584,4 +585,56 @@ public class IpSecPacketLossDetectorTest extends NetworkEvaluationTestBase {
                 MAX_SEQ_NUM_INCREASE_DEFAULT_DISABLED,
                 getMaxSeqNumIncreasePerSecond(mCarrierConfig));
     }
+
+    private IpSecPacketLossDetector newDetectorAndSetTransform(int threshold) throws Exception {
+        when(mCarrierConfig.getInt(
+                        eq(VCN_NETWORK_SELECTION_IPSEC_PACKET_LOSS_PERCENT_THRESHOLD_KEY),
+                        anyInt()))
+                .thenReturn(threshold);
+
+        final IpSecPacketLossDetector detector =
+                new IpSecPacketLossDetector(
+                        mVcnContext,
+                        mNetwork,
+                        mCarrierConfig,
+                        mMetricMonitorCallback,
+                        mDependencies);
+
+        detector.setIsSelectedUnderlyingNetwork(true /* setIsSelected */);
+        detector.setInboundTransformInternal(mIpSecTransform);
+
+        return detector;
+    }
+
+    @Test
+    public void testDisableAndEnableDetectorWithCarrierConfig() throws Exception {
+        final IpSecPacketLossDetector detector =
+                newDetectorAndSetTransform(IPSEC_PACKET_LOSS_PERCENT_THRESHOLD_DISABLE_DETECTOR);
+
+        assertFalse(detector.isStarted());
+
+        when(mCarrierConfig.getInt(
+                        eq(VCN_NETWORK_SELECTION_IPSEC_PACKET_LOSS_PERCENT_THRESHOLD_KEY),
+                        anyInt()))
+                .thenReturn(IPSEC_PACKET_LOSS_PERCENT_THRESHOLD);
+        detector.setCarrierConfig(mCarrierConfig);
+
+        assertTrue(detector.isStarted());
+    }
+
+    @Test
+    public void testEnableAndDisableDetectorWithCarrierConfig() throws Exception {
+        final IpSecPacketLossDetector detector =
+                newDetectorAndSetTransform(IPSEC_PACKET_LOSS_PERCENT_THRESHOLD);
+
+        assertTrue(detector.isStarted());
+
+        when(mCarrierConfig.getInt(
+                        eq(VCN_NETWORK_SELECTION_IPSEC_PACKET_LOSS_PERCENT_THRESHOLD_KEY),
+                        anyInt()))
+                .thenReturn(IPSEC_PACKET_LOSS_PERCENT_THRESHOLD_DISABLE_DETECTOR);
+        detector.setCarrierConfig(mCarrierConfig);
+
+        assertFalse(detector.isStarted());
+    }
 }
diff --git a/tests/vcn/java/com/android/server/vcn/routeselection/NetworkEvaluationTestBase.java b/tests/vcn/java/com/android/server/vcn/routeselection/NetworkEvaluationTestBase.java
index edad67896e8e..0439d5f54e23 100644
--- a/tests/vcn/java/com/android/server/vcn/routeselection/NetworkEvaluationTestBase.java
+++ b/tests/vcn/java/com/android/server/vcn/routeselection/NetworkEvaluationTestBase.java
@@ -123,6 +123,7 @@ public abstract class NetworkEvaluationTestBase {
         mSetFlagsRule.enableFlags(Flags.FLAG_VALIDATE_NETWORK_ON_IPSEC_LOSS);
         mSetFlagsRule.enableFlags(Flags.FLAG_EVALUATE_IPSEC_LOSS_ON_LP_NC_CHANGE);
         mSetFlagsRule.enableFlags(Flags.FLAG_HANDLE_SEQ_NUM_LEAP);
+        mSetFlagsRule.enableFlags(Flags.FLAG_ALLOW_DISABLE_IPSEC_LOSS_DETECTOR);
 
         when(mNetwork.getNetId()).thenReturn(-1);