commit 16b28e2b220111d70590be62316964f110945f31
author Lorenzo Colitti <lorenzo@google.com> Thu May 21 16:34:00 2020 +0900
committer Lorenzo Colitti <lorenzo@google.com> Thu May 21 17:26:00 2020 +0900
tree 2472e998c5b07b40be93b9926ae271d96b46a90a
parent 84f1909fb1b84a20148d140ad9b3f8ef8ff65b5f

Test that if an RA sets the same prefix as DNS, nothing happens.

This is not particularly likely to happen unless the pref64 RA is
sent by a different router than the main RA. But more tests are
always good, and this additional coverage will be more useful
in an upcoming change.

Bug: 150648313
Test: test-only change
Change-Id: I3316d49d42100800740afadc4edf0a13a4d8377c

tests/net/java/com/android/server/ConnectivityServiceTest.java

diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index 5e2ef04..c430370 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -6352,12 +6352,36 @@
         expectNat64PrefixChange(callback, mCellNetworkAgent, pref64FromDns);
         inOrder.verify(mMockNetd).clatdStart(iface, pref64FromDns.toString());
 
-        // If the RA prefix reappears, clatd is restarted and prefix discovery is stopped.
+        // If an RA advertises the same prefix that was discovered by DNS, nothing happens: prefix
+        // discovery is not stopped, and there are no callbacks.
+        lp.setNat64Prefix(pref64FromDns);
+        mCellNetworkAgent.sendLinkProperties(lp);
+        callback.assertNoCallback();
+        inOrder.verify(mMockNetd, never()).clatdStop(iface);
+        inOrder.verify(mMockNetd, never()).clatdStart(eq(iface), anyString());
+        inOrder.verify(mMockDnsResolver, never()).stopPrefix64Discovery(netId);
+        inOrder.verify(mMockDnsResolver, never()).startPrefix64Discovery(netId);
+
+        // If the RA is later withdrawn, nothing happens again.
+        lp.setNat64Prefix(null);
+        mCellNetworkAgent.sendLinkProperties(lp);
+        callback.assertNoCallback();
+        inOrder.verify(mMockNetd, never()).clatdStop(iface);
+        inOrder.verify(mMockNetd, never()).clatdStart(eq(iface), anyString());
+        inOrder.verify(mMockDnsResolver, never()).stopPrefix64Discovery(netId);
+        inOrder.verify(mMockDnsResolver, never()).startPrefix64Discovery(netId);
+
+        // If the RA prefix changes, clatd is restarted and prefix discovery is stopped.
         lp.setNat64Prefix(pref64FromRa);
         mCellNetworkAgent.sendLinkProperties(lp);
         expectNat64PrefixChange(callback, mCellNetworkAgent, pref64FromRa);
         inOrder.verify(mMockNetd).clatdStop(iface);
         inOrder.verify(mMockDnsResolver).stopPrefix64Discovery(netId);
+
+        // Stopping prefix discovery results in a prefix removed notification.
+        mService.mNetdEventCallback.onNat64PrefixEvent(netId, false /* added */,
+                pref64FromDnsStr, 96);
+
         inOrder.verify(mMockNetd).clatdStart(iface, pref64FromRa.toString());
         inOrder.verify(mMockDnsResolver, never()).startPrefix64Discovery(netId);