From d16138eeea4a517167f460750ac036401828bfdf Mon Sep 17 00:00:00 2001
From: Patrick Rohr <prohr@google.com>
Date: Wed, 29 Jan 2025 07:34:27 -0800
Subject: [PATCH] Stop tracking left-over test interfaces

When setIncludeTestInterfaces(false) is called, any RTM_DELLINK
callback for a testtap interface is ignored, since the interface is no
longer considered to be a valid ethernet interface.

Change setIncludeTestInterfaces to go through all interfaces, and stop
tracking the ones which are no longer valid. Otherwise, they will
stick around forever (and break subsequent tests).

Bug: 390722214
Test: TH
Change-Id: Ied73e86c0452831f4d6b00f67908c51201af8bbd
---
 .../server/ethernet/EthernetTracker.java      | 32 +++++++++++--------
 .../server/ethernet/EthernetTrackerTest.java  |  1 +
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/service-t/src/com/android/server/ethernet/EthernetTracker.java b/service-t/src/com/android/server/ethernet/EthernetTracker.java
index bb7963e215..9b3c7ba26d 100644
--- a/service-t/src/com/android/server/ethernet/EthernetTracker.java
+++ b/service-t/src/com/android/server/ethernet/EthernetTracker.java
@@ -397,6 +397,16 @@ public class EthernetTracker {
         return mFactory.hasInterface(iface);
     }
 
+    private List<String> getAllInterfaces() {
+        final ArrayList<String> interfaces = new ArrayList<>(
+                List.of(mFactory.getAvailableInterfaces(/* includeRestricted */ true)));
+
+        if (mTetheringInterfaceMode == INTERFACE_MODE_SERVER && mTetheringInterface != null) {
+            interfaces.add(mTetheringInterface);
+        }
+        return interfaces;
+    }
+
     String[] getClientModeInterfaces(boolean includeRestricted) {
         return mFactory.getAvailableInterfaces(includeRestricted);
     }
@@ -459,10 +469,16 @@ public class EthernetTracker {
     public void setIncludeTestInterfaces(boolean include) {
         mHandler.post(() -> {
             mIncludeTestInterfaces = include;
-            if (!include) {
+            if (include) {
+                trackAvailableInterfaces();
+            } else {
                 removeTestData();
+                // remove all test interfaces
+                for (String iface : getAllInterfaces()) {
+                    if (isValidEthernetInterface(iface)) continue;
+                    stopTrackingInterface(iface);
+                }
             }
-            trackAvailableInterfaces();
         });
     }
 
@@ -952,17 +968,7 @@ public class EthernetTracker {
             if (mIsEthernetEnabled == enabled) return;
 
             mIsEthernetEnabled = enabled;
-
-            // Interface in server mode should also be included.
-            ArrayList<String> interfaces =
-                    new ArrayList<>(
-                    List.of(mFactory.getAvailableInterfaces(/* includeRestricted */ true)));
-
-            if (mTetheringInterfaceMode == INTERFACE_MODE_SERVER && mTetheringInterface != null) {
-                interfaces.add(mTetheringInterface);
-            }
-
-            for (String iface : interfaces) {
+            for (String iface : getAllInterfaces()) {
                 setInterfaceUpState(iface, enabled);
             }
             broadcastEthernetStateChange(mIsEthernetEnabled);
diff --git a/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java b/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java
index b7cfaf9b52..533bbf8776 100644
--- a/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java
+++ b/tests/unit/java/com/android/server/ethernet/EthernetTrackerTest.java
@@ -79,6 +79,7 @@ public class EthernetTrackerTest {
         initMockResources();
         doReturn(false).when(mFactory).updateInterfaceLinkState(anyString(), anyBoolean());
         doReturn(new String[0]).when(mNetd).interfaceGetList();
+        doReturn(new String[0]).when(mFactory).getAvailableInterfaces(anyBoolean());
         mHandlerThread = new HandlerThread(THREAD_NAME);
         mHandlerThread.start();
         tracker = new EthernetTracker(mContext, mHandlerThread.getThreadHandler(), mFactory, mNetd,