Support removing specific routes from local_network

Bug: 9580643
Change-Id: Id0aaf4bc7424797e2beef03fb18a2c1885a86509

core/java/android/os/INetworkManagementService.aidl

@@ -442,6 +442,7 @@ interface INetworkManagementService
 
     void addInterfaceToLocalNetwork(String iface, in List<RouteInfo> routes);
     void removeInterfaceFromLocalNetwork(String iface);
+    int removeRoutesFromLocalNetwork(in List<RouteInfo> routes);
 
     void setAllowOnlyVpnForUids(boolean enable, in UidRange[] uidRanges);
 }

services/core/java/com/android/server/NetworkManagementService.java

@@ -2774,4 +2774,19 @@ public class NetworkManagementService extends INetworkManagementService.Stub
     public void removeInterfaceFromLocalNetwork(String iface) {
         modifyInterfaceInNetwork("remove", "local", iface);
     }
+
+    @Override
+    public int removeRoutesFromLocalNetwork(List<RouteInfo> routes) {
+        int failures = 0;
+
+        for (RouteInfo route : routes) {
+            try {
+                modifyRoute("remove", "local", route);
+            } catch (IllegalStateException e) {
+                failures++;
+            }
+        }
+
+        return failures;
+    }
 }

services/core/java/com/android/server/connectivity/tethering/IPv6TetheringInterfaceServices.java

@@ -157,8 +157,17 @@ class IPv6TetheringInterfaceServices {
             }
         } else {
             if (mLastLocalRoutes != null && !mLastLocalRoutes.isEmpty()) {
-                // TODO: Remove only locally added network routes.
-                // mNMSwervice.removeInterfaceFromLocalNetwork(mIfName);
+                try {
+                    final int removalFailures =
+                            mNMService.removeRoutesFromLocalNetwork(mLastLocalRoutes);
+                    if (removalFailures > 0) {
+                        Log.e(TAG,
+                                String.format("Failed to remove %d IPv6 routes from local table.",
+                                removalFailures));
+                    }
+                } catch (RemoteException e) {
+                    Log.e(TAG, "Failed to remove IPv6 routes from local table: ", e);
+                }
             }
         }