Filter out excluded routes in LinkProperties

Gate presence of excluded routes in LinkProperties on target sdk T.

Bug: 186082280
Test: atest LinkPropertiesTest
Change-Id: If8fdb468a0a4968c5f2a878b7aacfeb4f7d9a9e5

Tethering/apex/Android.bp

@@ -90,6 +90,8 @@ apex {
     compressible: true,
 
     androidManifest: "AndroidManifest.xml",
+
+    compat_configs: ["connectivity-platform-compat-config"],
 }
 
 apex_key {

framework/Android.bp

@@ -92,6 +92,7 @@ java_defaults {
         "modules-utils-preconditions",
     ],
     libs: [
+        "app-compat-annotations",
         "framework-connectivity-t.stubs.module_lib",
         "unsupportedappusage",
     ],
@@ -152,6 +153,11 @@ java_sdk_library {
     ],
 }
 
+platform_compat_config {
+    name: "connectivity-platform-compat-config",
+    src: ":framework-connectivity",
+}
+
 cc_library_shared {
     name: "libframework-connectivity-jni",
     min_sdk_version: "30",

framework/src/android/net/LinkProperties.java

@@ -19,12 +19,16 @@ package android.net;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemApi;
+import android.app.compat.CompatChanges;
+import android.compat.annotation.ChangeId;
+import android.compat.annotation.EnabledAfter;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.os.Build;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.text.TextUtils;
 
+import com.android.internal.annotations.VisibleForTesting;
 import com.android.net.module.util.LinkPropertiesUtils;
 
 import java.net.Inet4Address;
@@ -38,6 +42,7 @@ import java.util.Hashtable;
 import java.util.List;
 import java.util.Objects;
 import java.util.StringJoiner;
+import java.util.stream.Collectors;
 
 /**
  * Describes the properties of a network link.
@@ -52,6 +57,17 @@ import java.util.StringJoiner;
  *
  */
 public final class LinkProperties implements Parcelable {
+    /**
+     * The {@link #getRoutes()} now can contain excluded as well as included routes. Use
+     * {@link RouteInfo#getType()} to determine route type.
+     *
+     * @hide
+     */
+    @ChangeId
+    @EnabledAfter(targetSdkVersion = Build.VERSION_CODES.S) // Switch to S_V2 when it is available.
+    @VisibleForTesting
+    public static final long EXCLUDED_ROUTES = 186082280;
+
     // The interface described by the network link.
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
     private String mIfaceName;
@@ -738,10 +754,25 @@ public final class LinkProperties implements Parcelable {
     /**
      * Returns all the {@link RouteInfo} set on this link.
      *
+     * Only unicast routes are returned for apps targeting Android S or below.
+     *
      * @return An unmodifiable {@link List} of {@link RouteInfo} for this link.
      */
     public @NonNull List<RouteInfo> getRoutes() {
-        return Collections.unmodifiableList(mRoutes);
+        if (CompatChanges.isChangeEnabled(EXCLUDED_ROUTES)) {
+            return Collections.unmodifiableList(mRoutes);
+        } else {
+            return Collections.unmodifiableList(getUnicastRoutes());
+        }
+    }
+
+    /**
+     * Returns all the {@link RouteInfo} of type {@link RouteInfo#RTN_UNICAST} set on this link.
+     */
+    private @NonNull List<RouteInfo> getUnicastRoutes() {
+        return mRoutes.stream()
+                .filter(route -> route.getType() == RouteInfo.RTN_UNICAST)
+                .collect(Collectors.toList());
     }
 
     /**
@@ -757,11 +788,14 @@ public final class LinkProperties implements Parcelable {
 
     /**
      * Returns all the routes on this link and all the links stacked above it.
+     *
+     * Only unicast routes are returned for apps targeting Android S or below.
+     *
      * @hide
      */
     @SystemApi
     public @NonNull List<RouteInfo> getAllRoutes() {
-        List<RouteInfo> routes = new ArrayList<>(mRoutes);
+        final List<RouteInfo> routes = new ArrayList<>(getRoutes());
         for (LinkProperties stacked: mStackedLinks.values()) {
             routes.addAll(stacked.getAllRoutes());
         }

tests/common/Android.bp

@@ -36,6 +36,7 @@ java_library {
         "modules-utils-build",
         "net-tests-utils",
         "net-utils-framework-common",
+        "platform-compat-test-rules",
         "platform-test-annotations",
     ],
     libs: [

tests/common/java/android/net/LinkPropertiesTest.java

@@ -20,6 +20,7 @@ import static android.net.RouteInfo.RTN_THROW;
 import static android.net.RouteInfo.RTN_UNICAST;
 import static android.net.RouteInfo.RTN_UNREACHABLE;
 
+import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
 import static com.android.testutils.ParcelUtils.assertParcelingIsLossless;
 import static com.android.testutils.ParcelUtils.parcelingRoundTrip;
 
@@ -30,6 +31,7 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import android.compat.testing.PlatformCompatChangeRule;
 import android.net.LinkProperties.ProvisioningChange;
 import android.os.Build;
 import android.system.OsConstants;
@@ -45,6 +47,9 @@ import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreAfter;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
 
+import libcore.junit.util.compat.CoreCompatChangeRule.DisableCompatChanges;
+import libcore.junit.util.compat.CoreCompatChangeRule.EnableCompatChanges;
+
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -65,6 +70,9 @@ public class LinkPropertiesTest {
     @Rule
     public final DevSdkIgnoreRule ignoreRule = new DevSdkIgnoreRule();
 
+    @Rule
+    public final PlatformCompatChangeRule compatChangeRule = new PlatformCompatChangeRule();
+
     private static final InetAddress ADDRV4 = address("75.208.6.1");
     private static final InetAddress ADDRV6 = address("2001:0db8:85a3:0000:0000:8a2e:0370:7334");
     private static final InetAddress DNS1 = address("75.208.7.1");
@@ -1254,6 +1262,7 @@ public class LinkPropertiesTest {
     }
 
     @Test @IgnoreUpTo(Build.VERSION_CODES.Q)
+    @EnableCompatChanges({LinkProperties.EXCLUDED_ROUTES})
     public void testRouteAddWithSameKey() throws Exception {
         LinkProperties lp = new LinkProperties();
         lp.setInterfaceName("wlan0");
@@ -1268,4 +1277,36 @@ public class LinkPropertiesTest {
         lp.addRoute(new RouteInfo(v4, address("192.0.2.1"), "wlan0", RTN_THROW, 1460));
         assertEquals(2, lp.getRoutes().size());
     }
+
+    @Test @IgnoreUpTo(SC_V2)
+    @EnableCompatChanges({LinkProperties.EXCLUDED_ROUTES})
+    public void testExcludedRoutesEnabled() {
+        final LinkProperties lp = new LinkProperties();
+        assertEquals(0, lp.getRoutes().size());
+
+        lp.addRoute(new RouteInfo(new IpPrefix(ADDRV4, 0), RTN_UNREACHABLE));
+        assertEquals(1, lp.getRoutes().size());
+
+        lp.addRoute(new RouteInfo(new IpPrefix(ADDRV6, 0), RTN_THROW));
+        assertEquals(2, lp.getRoutes().size());
+
+        lp.addRoute(new RouteInfo(GATEWAY1));
+        assertEquals(3, lp.getRoutes().size());
+    }
+
+    @Test @IgnoreUpTo(SC_V2)
+    @DisableCompatChanges({LinkProperties.EXCLUDED_ROUTES})
+    public void testExcludedRoutesDisabled() {
+        final LinkProperties lp = new LinkProperties();
+        assertEquals(0, lp.getRoutes().size());
+
+        lp.addRoute(new RouteInfo(new IpPrefix(ADDRV4, 0), RTN_UNREACHABLE));
+        assertEquals(0, lp.getRoutes().size());
+
+        lp.addRoute(new RouteInfo(new IpPrefix(ADDRV6, 5), RTN_THROW));
+        assertEquals(0, lp.getRoutes().size());
+
+        lp.addRoute(new RouteInfo(new IpPrefix(ADDRV6, 2), RTN_UNICAST));
+        assertEquals(1, lp.getRoutes().size());
+    }
 }