Make the Nat464Xlat tests more realistic.

464xlat will never be started on a network that is not connected,
or on a network that has no IPv6 address.

This is a no-op test-only change but it is necessary for an
upcoming change that violates some of the invalid assumptions
currently made by this test and causes it to fail.

Bug: 150648313
Test: test-only change
Change-Id: I41766e9adaa7c24454648b371e6e3cc647693be5
diff --git a/tests/net/java/com/android/server/connectivity/Nat464XlatTest.java b/tests/net/java/com/android/server/connectivity/Nat464XlatTest.java
index 84dad98..5046b65 100644
--- a/tests/net/java/com/android/server/connectivity/Nat464XlatTest.java
+++ b/tests/net/java/com/android/server/connectivity/Nat464XlatTest.java
@@ -58,6 +58,7 @@
 
     static final String BASE_IFACE = "test0";
     static final String STACKED_IFACE = "v4-test0";
+    static final LinkAddress V6ADDR = new LinkAddress("2001:db8:1::f00/64");
     static final LinkAddress ADDR = new LinkAddress("192.0.2.5/29");
     static final String NAT64_PREFIX = "64:ff9b::/96";
     static final String OTHER_NAT64_PREFIX = "2001:db8:0:64::/96";
@@ -82,6 +83,14 @@
         };
     }
 
+    private void markNetworkConnected() {
+        mNai.networkInfo.setDetailedState(NetworkInfo.DetailedState.CONNECTED, "", "");
+    }
+
+    private void markNetworkDisconnected() {
+        mNai.networkInfo.setDetailedState(NetworkInfo.DetailedState.DISCONNECTED, "", "");
+    }
+
     @Before
     public void setUp() throws Exception {
         mLooper = new TestLooper();
@@ -93,6 +102,7 @@
         mNai.linkProperties.setInterfaceName(BASE_IFACE);
         mNai.networkInfo = new NetworkInfo(null);
         mNai.networkInfo.setType(ConnectivityManager.TYPE_WIFI);
+        markNetworkConnected();
         when(mNai.connService()).thenReturn(mConnectivity);
         when(mNai.netAgentConfig()).thenReturn(mAgentConfig);
         when(mNai.handler()).thenReturn(mHandler);
@@ -177,11 +187,20 @@
         }
     }
 
-    @Test
-    public void testNormalStartAndStop() throws Exception {
+    private void makeClatUnnecessary(boolean dueToDisconnect) {
+        if (dueToDisconnect) {
+            markNetworkDisconnected();
+        } else {
+            mNai.linkProperties.addLinkAddress(ADDR);
+        }
+    }
+
+    private void checkNormalStartAndStop(boolean dueToDisconnect) throws Exception {
         Nat464Xlat nat = makeNat464Xlat();
         ArgumentCaptor<LinkProperties> c = ArgumentCaptor.forClass(LinkProperties.class);
 
+        mNai.linkProperties.addLinkAddress(V6ADDR);
+
         nat.setNat64PrefixFromDns(new IpPrefix(NAT64_PREFIX));
 
         // Start clat.
@@ -201,6 +220,7 @@
         assertRunning(nat);
 
         // Stop clat (Network disconnects, IPv4 addr appears, ...).
+        makeClatUnnecessary(dueToDisconnect);
         nat.stop();
 
         verify(mNetd).clatdStop(eq(BASE_IFACE));
@@ -218,11 +238,23 @@
         verifyNoMoreInteractions(mNetd, mNms, mConnectivity);
     }
 
+    @Test
+    public void testNormalStartAndStopDueToDisconnect() throws Exception {
+        checkNormalStartAndStop(true);
+    }
+
+    @Test
+    public void testNormalStartAndStopDueToIpv4Addr() throws Exception {
+        checkNormalStartAndStop(false);
+    }
+
     private void checkStartStopStart(boolean interfaceRemovedFirst) throws Exception {
         Nat464Xlat nat = makeNat464Xlat();
         ArgumentCaptor<LinkProperties> c = ArgumentCaptor.forClass(LinkProperties.class);
         InOrder inOrder = inOrder(mNetd, mConnectivity);
 
+        mNai.linkProperties.addLinkAddress(V6ADDR);
+
         nat.setNat64PrefixFromDns(new IpPrefix(NAT64_PREFIX));
 
         nat.start();
@@ -345,10 +377,11 @@
         verifyNoMoreInteractions(mNetd, mNms, mConnectivity);
     }
 
-    @Test
-    public void testStopBeforeClatdStarts() throws Exception {
+    private void checkStopBeforeClatdStarts(boolean dueToDisconnect) throws Exception {
         Nat464Xlat nat = makeNat464Xlat();
 
+        mNai.linkProperties.addLinkAddress(new LinkAddress("2001:db8::1/64"));
+
         nat.setNat64PrefixFromDns(new IpPrefix(NAT64_PREFIX));
 
         nat.start();
@@ -357,6 +390,7 @@
         verify(mNetd).clatdStart(eq(BASE_IFACE), eq(NAT64_PREFIX));
 
         // ConnectivityService immediately stops clat (Network disconnects, IPv4 addr appears, ...)
+        makeClatUnnecessary(dueToDisconnect);
         nat.stop();
 
         verify(mNetd).clatdStop(eq(BASE_IFACE));
@@ -378,9 +412,20 @@
     }
 
     @Test
-    public void testStopAndClatdNeverStarts() throws Exception {
+    public void testStopDueToDisconnectBeforeClatdStarts() throws Exception {
+        checkStopBeforeClatdStarts(true);
+    }
+
+    @Test
+    public void testStopDueToIpv4AddrBeforeClatdStarts() throws Exception {
+        checkStopBeforeClatdStarts(false);
+    }
+
+    private void checkStopAndClatdNeverStarts(boolean dueToDisconnect) throws Exception {
         Nat464Xlat nat = makeNat464Xlat();
 
+        mNai.linkProperties.addLinkAddress(new LinkAddress("2001:db8::1/64"));
+
         nat.setNat64PrefixFromDns(new IpPrefix(NAT64_PREFIX));
 
         nat.start();
@@ -389,6 +434,7 @@
         verify(mNetd).clatdStart(eq(BASE_IFACE), eq(NAT64_PREFIX));
 
         // ConnectivityService immediately stops clat (Network disconnects, IPv4 addr appears, ...)
+        makeClatUnnecessary(dueToDisconnect);
         nat.stop();
 
         verify(mNetd).clatdStop(eq(BASE_IFACE));
@@ -400,6 +446,16 @@
     }
 
     @Test
+    public void testStopDueToDisconnectAndClatdNeverStarts() throws Exception {
+        checkStopAndClatdNeverStarts(true);
+    }
+
+    @Test
+    public void testStopDueToIpv4AddressAndClatdNeverStarts() throws Exception {
+        checkStopAndClatdNeverStarts(false);
+    }
+
+    @Test
     public void testNat64PrefixPreference() throws Exception {
         final IpPrefix prefixFromDns = new IpPrefix(NAT64_PREFIX);
         final IpPrefix prefixFromRa = new IpPrefix(OTHER_NAT64_PREFIX);