Merge "Enable TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION by default on 25Q2+" into main
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index b3e9c1b..42aa3bd 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -130,9 +130,6 @@
     public static final String TETHER_ENABLE_WEAR_TETHERING =
             "tether_enable_wear_tethering";
 
-    public static final String TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION =
-            "tether_force_random_prefix_base_selection";
-
     public static final String TETHER_ENABLE_SYNC_SM = "tether_enable_sync_sm";
 
     /**
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/PrivateAddressCoordinatorTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/PrivateAddressCoordinatorTest.java
index f9e3a6a..ada88fb 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/PrivateAddressCoordinatorTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/PrivateAddressCoordinatorTest.java
@@ -26,7 +26,6 @@
 import static android.net.TetheringManager.TETHERING_WIFI_P2P;
 import static android.net.ip.IpServer.CMD_NOTIFY_PREFIX_CONFLICT;
 
-import static com.android.net.module.util.PrivateAddressCoordinator.TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION;
 import static com.android.networkstack.tethering.util.PrefixUtils.asIpPrefix;
 
 import static org.junit.Assert.assertEquals;
@@ -51,6 +50,7 @@
 import android.net.Network;
 import android.net.NetworkCapabilities;
 import android.net.ip.IpServer;
+import android.os.Build;
 import android.os.IBinder;
 
 import androidx.test.filters.SmallTest;
@@ -58,8 +58,10 @@
 
 import com.android.net.module.util.IIpv4PrefixRequest;
 import com.android.net.module.util.PrivateAddressCoordinator;
+import com.android.testutils.DevSdkIgnoreRule;
 
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
@@ -71,6 +73,9 @@
 @RunWith(AndroidJUnit4.class)
 @SmallTest
 public final class PrivateAddressCoordinatorTest {
+    @Rule
+    public final DevSdkIgnoreRule mIgnoreRule = new DevSdkIgnoreRule();
+
     private static final String TEST_IFNAME = "test0";
 
     @Mock private IpServer mHotspotIpServer;
@@ -231,11 +236,9 @@
         assertEquals(usbAddress, newUsbAddress);
 
         final UpstreamNetworkState wifiUpstream = buildUpstreamNetworkState(mWifiNetwork,
-                new LinkAddress("192.168.88.23/16"), null,
-                makeNetworkCapabilities(TRANSPORT_WIFI));
+                hotspotAddress, null, makeNetworkCapabilities(TRANSPORT_WIFI));
         updateUpstreamPrefix(wifiUpstream);
         verify(mHotspotIpServer).sendMessage(IpServer.CMD_NOTIFY_PREFIX_CONFLICT);
-        verify(mUsbIpServer).sendMessage(IpServer.CMD_NOTIFY_PREFIX_CONFLICT);
     }
 
     private UpstreamNetworkState buildUpstreamNetworkState(final Network network,
@@ -323,10 +326,9 @@
         assertFalse(localHotspotPrefix.containsPrefix(hotspotPrefix));
     }
 
+    @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.VANILLA_ICE_CREAM)
     @Test
     public void testStartedPrefixRange() throws Exception {
-        when(mDeps.isFeatureEnabled(TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION)).thenReturn(true);
-
         startedPrefixBaseTest("192.168.0.0/16", 0);
 
         startedPrefixBaseTest("192.168.0.0/16", 1);
diff --git a/staticlibs/device/com/android/net/module/util/PrivateAddressCoordinator.java b/staticlibs/device/com/android/net/module/util/PrivateAddressCoordinator.java
index bb95585..2ce5b86 100644
--- a/staticlibs/device/com/android/net/module/util/PrivateAddressCoordinator.java
+++ b/staticlibs/device/com/android/net/module/util/PrivateAddressCoordinator.java
@@ -33,12 +33,14 @@
 import android.net.LinkProperties;
 import android.net.Network;
 import android.net.NetworkCapabilities;
+import android.os.Build;
 import android.os.RemoteException;
 import android.util.ArrayMap;
 
 import androidx.annotation.Nullable;
 
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.modules.utils.build.SdkLevel;
 
 import java.io.PrintWriter;
 import java.net.Inet4Address;
@@ -67,9 +69,6 @@
     // WARNING: Keep in sync with chooseDownstreamAddress
     public static final int PREFIX_LENGTH = 24;
 
-    public static final String TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION =
-            "tether_force_random_prefix_base_selection";
-
     // Upstream monitor would be stopped when tethering is down. When tethering restart, downstream
     // address may be requested before coordinator get current upstream notification. To ensure
     // coordinator do not select conflict downstream prefix, mUpstreamPrefixMap would not be cleared
@@ -258,8 +257,15 @@
         return null;
     }
 
+    // TODO: Remove this method when SdkLevel.isAtLeastB() is fixed, aosp is at sdk level 36 or use
+    //  NetworkStackUtils.isAtLeast25Q2 when it is moved to a static lib.
+    public static boolean isAtLeast25Q2() {
+        return SdkLevel.isAtLeastB()  || (SdkLevel.isAtLeastV()
+                && "Baklava".equals(Build.VERSION.CODENAME));
+    }
+
     private int getRandomPrefixIndex() {
-        if (!mDeps.isFeatureEnabled(TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION)) return 0;
+        if (!isAtLeast25Q2()) return 0;
 
         final int random = getRandomInt() & 0xffffff;
         // This is to select the starting prefix range (/8, /12, or /16) instead of the actual