From a8696bc9a31d69a3222cee8dab3d1b207801129c Mon Sep 17 00:00:00 2001
From: Benedict Wong <benedictwong@google.com>
Date: Thu, 3 Mar 2022 22:54:01 +0000
Subject: [PATCH] Trigger revalidation of VCN, underlying networks

This change adds triggers additional revalidation of the VCN and
underlying networks in the following cases:

Triggers VCN Network revalidation after mobility events. This is the
most likely time that the VCN will suddenly fail to validate, this helps
to detect it as quickly as possible.

Triggers underlying network validation if the VCN validation fails; if
the underlying network fails, the VCN will migrate away. When the VCN
fails to validate, it is unclear whether it is a VCN dataplane issue, or
an underlying network issue.

Bug: 222351571
Test: atest FrameworksVcnTests
Change-Id: I4d77e9977ae7dbf0fcc1cccb29b25c57002a6daf
---
 .../android/server/vcn/VcnGatewayConnection.java   | 14 ++++++++++++++
 .../VcnGatewayConnectionConnectedStateTest.java    |  6 ++++++
 2 files changed, 20 insertions(+)

diff --git a/services/core/java/com/android/server/vcn/VcnGatewayConnection.java b/services/core/java/com/android/server/vcn/VcnGatewayConnection.java
index 597f7f284730..be38005abb63 100644
--- a/services/core/java/com/android/server/vcn/VcnGatewayConnection.java
+++ b/services/core/java/com/android/server/vcn/VcnGatewayConnection.java
@@ -544,6 +544,7 @@ public class VcnGatewayConnection extends StateMachine {
     private final boolean mIsMobileDataEnabled;
 
     @NonNull private final IpSecManager mIpSecManager;
+    @NonNull private final ConnectivityManager mConnectivityManager;
 
     @Nullable private IpSecTunnelInterface mTunnelIface = null;
 
@@ -701,6 +702,7 @@ public class VcnGatewayConnection extends StateMachine {
                         mLastSnapshot,
                         mUnderlyingNetworkControllerCallback);
         mIpSecManager = mVcnContext.getContext().getSystemService(IpSecManager.class);
+        mConnectivityManager = mVcnContext.getContext().getSystemService(ConnectivityManager.class);
 
         addState(mDisconnectedState);
         addState(mDisconnectingState);
@@ -1683,6 +1685,14 @@ public class VcnGatewayConnection extends StateMachine {
                                         clearFailedAttemptCounterAndSafeModeAlarm();
                                         break;
                                     case NetworkAgent.VALIDATION_STATUS_NOT_VALID:
+                                        // Trigger re-validation of underlying networks; if it
+                                        // fails, the VCN will attempt to migrate away.
+                                        if (mUnderlying != null) {
+                                            mConnectivityManager.reportNetworkConnectivity(
+                                                    mUnderlying.network,
+                                                    false /* hasConnectivity */);
+                                        }
+
                                         // Will only set a new alarm if no safe mode alarm is
                                         // currently scheduled.
                                         setSafeModeAlarm();
@@ -1869,6 +1879,10 @@ public class VcnGatewayConnection extends StateMachine {
                     IpSecManager.DIRECTION_OUT);
 
             updateNetworkAgent(mTunnelIface, mNetworkAgent, mChildConfig);
+
+            // Trigger re-validation after migration events.
+            mConnectivityManager.reportNetworkConnectivity(
+                    mNetworkAgent.getNetwork(), false /* hasConnectivity */);
         }
 
         private void handleUnderlyingNetworkChanged(@NonNull Message msg) {
diff --git a/tests/vcn/java/com/android/server/vcn/VcnGatewayConnectionConnectedStateTest.java b/tests/vcn/java/com/android/server/vcn/VcnGatewayConnectionConnectedStateTest.java
index 4cfa93b4ecf9..841b81c2a282 100644
--- a/tests/vcn/java/com/android/server/vcn/VcnGatewayConnectionConnectedStateTest.java
+++ b/tests/vcn/java/com/android/server/vcn/VcnGatewayConnectionConnectedStateTest.java
@@ -252,6 +252,9 @@ public class VcnGatewayConnectionConnectedStateTest extends VcnGatewayConnection
                         && TEST_TCP_BUFFER_SIZES_2.equals(lp.getTcpBufferSizes())));
         verify(mNetworkAgent)
                 .setUnderlyingNetworks(eq(singletonList(TEST_UNDERLYING_NETWORK_RECORD_2.network)));
+
+        // Verify revalidation is triggered on VCN network
+        verify(mConnMgr).reportNetworkConnectivity(eq(mNetworkAgent.getNetwork()), eq(false));
     }
 
     private void triggerChildOpened() {
@@ -425,6 +428,9 @@ public class VcnGatewayConnectionConnectedStateTest extends VcnGatewayConnection
         triggerValidation(NetworkAgent.VALIDATION_STATUS_NOT_VALID);
         mTestLooper.dispatchAll();
 
+        verify(mConnMgr)
+                .reportNetworkConnectivity(eq(TEST_UNDERLYING_NETWORK_RECORD_1.network), eq(false));
+
         final ArgumentCaptor<Runnable> runnableCaptor = ArgumentCaptor.forClass(Runnable.class);
         verify(mDeps, times(2))
                 .newWakeupMessage(