Make interface IP serving code set LinkProperties

Additionally, clean up awkward IPv6TetheringInterfaceServices
instantiation mechanics.  In future, this class will be absorbed
by TetherInterfaceStateMachine (prior to its renaming to IpServer).

Test: as follows
    - built
    - flashed
    - booted
    - runtest frameworks-net passes
Bug: 29337859
Bug: 32163131

Change-Id: Ib620e3df182f9f8e2c019aae1cd8981eb0b29376
diff --git a/tests/net/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachineTest.java b/tests/net/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachineTest.java
index ce419a5..db5373a 100644
--- a/tests/net/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachineTest.java
+++ b/tests/net/java/com/android/server/connectivity/tethering/TetherInterfaceStateMachineTest.java
@@ -16,6 +16,8 @@
 
 package com.android.server.connectivity.tethering;
 
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.any;
 import static org.mockito.Matchers.anyString;
 import static org.mockito.Matchers.eq;
@@ -40,17 +42,23 @@
 import android.net.ConnectivityManager;
 import android.net.INetworkStatsService;
 import android.net.InterfaceConfiguration;
+import android.net.LinkAddress;
 import android.net.LinkProperties;
+import android.net.RouteInfo;
 import android.net.util.SharedLog;
 import android.os.INetworkManagementService;
 import android.os.RemoteException;
 import android.os.test.TestLooper;
 import android.support.test.filters.SmallTest;
 import android.support.test.runner.AndroidJUnit4;
+import android.text.TextUtils;
+
+import java.net.Inet4Address;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
 import org.mockito.InOrder;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
@@ -69,6 +77,8 @@
     @Mock private SharedLog mSharedLog;
 
     private final TestLooper mLooper = new TestLooper();
+    private final ArgumentCaptor<LinkProperties> mLinkPropertiesCaptor =
+            ArgumentCaptor.forClass(LinkProperties.class);
     private TetherInterfaceStateMachine mTestedSm;
 
     private void initStateMachine(int interfaceType) throws Exception {
@@ -77,7 +87,7 @@
                 mNMService, mStatsService, mTetherHelper);
         mTestedSm.start();
         // Starting the state machine always puts us in a consistent state and notifies
-        // the test of the world that we've changed from an unknown to available state.
+        // the rest of the world that we've changed from an unknown to available state.
         mLooper.dispatchAll();
         reset(mNMService, mStatsService, mTetherHelper);
         when(mNMService.getInterfaceConfig(IFACE_NAME)).thenReturn(mInterfaceConfiguration);
@@ -181,7 +191,8 @@
         inOrder.verify(mTetherHelper).updateInterfaceState(
                 mTestedSm, STATE_TETHERED, TETHER_ERROR_NO_ERROR);
         inOrder.verify(mTetherHelper).updateLinkProperties(
-                eq(mTestedSm), any(LinkProperties.class));
+                eq(mTestedSm), mLinkPropertiesCaptor.capture());
+        assertIPv4AddressAndDirectlyConnectedRoute(mLinkPropertiesCaptor.getValue());
         verifyNoMoreInteractions(mNMService, mStatsService, mTetherHelper);
     }
 
@@ -281,7 +292,8 @@
             usbTeardownOrder.verify(mTetherHelper).updateInterfaceState(
                     mTestedSm, STATE_UNAVAILABLE, TETHER_ERROR_NO_ERROR);
             usbTeardownOrder.verify(mTetherHelper).updateLinkProperties(
-                    eq(mTestedSm), any(LinkProperties.class));
+                    eq(mTestedSm), mLinkPropertiesCaptor.capture());
+            assertNoAddressesNorRoutes(mLinkPropertiesCaptor.getValue());
         }
     }
 
@@ -298,7 +310,8 @@
         usbTeardownOrder.verify(mTetherHelper).updateInterfaceState(
                 mTestedSm, STATE_AVAILABLE, TETHER_ERROR_TETHER_IFACE_ERROR);
         usbTeardownOrder.verify(mTetherHelper).updateLinkProperties(
-                eq(mTestedSm), any(LinkProperties.class));
+                eq(mTestedSm), mLinkPropertiesCaptor.capture());
+        assertNoAddressesNorRoutes(mLinkPropertiesCaptor.getValue());
     }
 
     @Test
@@ -313,7 +326,8 @@
         usbTeardownOrder.verify(mTetherHelper).updateInterfaceState(
                 mTestedSm, STATE_AVAILABLE, TETHER_ERROR_ENABLE_NAT_ERROR);
         usbTeardownOrder.verify(mTetherHelper).updateLinkProperties(
-                eq(mTestedSm), any(LinkProperties.class));
+                eq(mTestedSm), mLinkPropertiesCaptor.capture());
+        assertNoAddressesNorRoutes(mLinkPropertiesCaptor.getValue());
     }
 
     @Test
@@ -360,4 +374,28 @@
                 upstreamIface);
         mLooper.dispatchAll();
     }
+
+    private void assertIPv4AddressAndDirectlyConnectedRoute(LinkProperties lp) {
+        // Find the first IPv4 LinkAddress.
+        LinkAddress addr4 = null;
+        for (LinkAddress addr : lp.getLinkAddresses()) {
+            if (!(addr.getAddress() instanceof Inet4Address)) continue;
+            addr4 = addr;
+            break;
+        }
+        assertTrue("missing IPv4 address", addr4 != null);
+
+        // Assert the presence of the associated directly connected route.
+        final RouteInfo directlyConnected = new RouteInfo(addr4, null, lp.getInterfaceName());
+        assertTrue("missing directly connected route: '" + directlyConnected.toString() + "'",
+                   lp.getRoutes().contains(directlyConnected));
+    }
+
+    private void assertNoAddressesNorRoutes(LinkProperties lp) {
+        assertTrue(lp.getLinkAddresses().isEmpty());
+        assertTrue(lp.getRoutes().isEmpty());
+        // We also check that interface name is non-empty, because we should
+        // never see an empty interface name in any LinkProperties update.
+        assertFalse(TextUtils.isEmpty(lp.getInterfaceName()));
+    }
 }