commit b3eccf7b8ab9bdf61bf9a93192defd968baad780
author chiachangwang <chiachangwang@google.com> Tue Jun 20 02:41:52 2023 +0000
committer chiachangwang <chiachangwang@google.com> Wed Jun 21 06:43:28 2023 +0000
tree 356400e3772539b659eb3a4e5c62166355b10e9d
parent d07be2decbd0643a33411761ac8623af76d47142

Reset the generated v6 clat address when stop

The v6 address is generated from the prefix when clat is started.
The address should be reset when clat is stop.

Test: atest FrameworksNetTests
Change-Id: I943d4efba85dda556dd1ec852322caaf9470e87b

service/src/com/android/server/connectivity/Nat464Xlat.java

diff --git a/service/src/com/android/server/connectivity/Nat464Xlat.java b/service/src/com/android/server/connectivity/Nat464Xlat.java
index 4f1f871..b315235 100644
--- a/service/src/com/android/server/connectivity/Nat464Xlat.java
+++ b/service/src/com/android/server/connectivity/Nat464Xlat.java
@@ -101,7 +101,8 @@
     private IpPrefix mNat64PrefixFromRa;
     private String mBaseIface;
     private String mIface;
-    private Inet6Address mIPv6Address;
+    @VisibleForTesting
+    Inet6Address mIPv6Address;
     private State mState = State.IDLE;
     private final ClatCoordinator mClatCoordinator;  // non-null iff T+
 
@@ -241,6 +242,7 @@
         mNat64PrefixInUse = null;
         mIface = null;
         mBaseIface = null;
+        mIPv6Address = null;
 
         if (!mPrefixDiscoveryRunning) {
             setPrefix64(null);
@@ -577,7 +579,6 @@
     public Inet6Address getClatv6SrcAddress() {
         // Variables in Nat464Xlat should only be accessed from handler thread.
         ensureRunningOnHandlerThread();
-        if (!isStarted()) return null;
 
         return mIPv6Address;
     }

tests/unit/java/com/android/server/connectivity/Nat464XlatTest.java

diff --git a/tests/unit/java/com/android/server/connectivity/Nat464XlatTest.java b/tests/unit/java/com/android/server/connectivity/Nat464XlatTest.java
index 06e0d6d..58c0114 100644
--- a/tests/unit/java/com/android/server/connectivity/Nat464XlatTest.java
+++ b/tests/unit/java/com/android/server/connectivity/Nat464XlatTest.java
@@ -20,10 +20,12 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.anyInt;
 import static org.mockito.Mockito.anyString;
+import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.never;
@@ -72,6 +74,7 @@
     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 CLAT_V6 = "64:ff9b::1";
     static final String NAT64_PREFIX = "64:ff9b::/96";
     static final String OTHER_NAT64_PREFIX = "2001:db8:0:64::/96";
     static final int NETID = 42;
@@ -132,6 +135,8 @@
         when(mNetd.interfaceGetCfg(eq(STACKED_IFACE))).thenReturn(mConfig);
         mConfig.ipv4Addr = ADDR.getAddress().getHostAddress();
         mConfig.prefixLength =  ADDR.getPrefixLength();
+        doReturn(CLAT_V6).when(mClatCoordinator).clatStart(
+                BASE_IFACE, NETID, new IpPrefix(NAT64_PREFIX));
     }
 
     private void assertRequiresClat(boolean expected, NetworkAgentInfo nai) {
@@ -286,7 +291,8 @@
         assertFalse(c.getValue().getAllInterfaceNames().contains(STACKED_IFACE));
         verify(mDnsResolver).stopPrefix64Discovery(eq(NETID));
         assertIdle(nat);
-
+        // Verify the generated v6 is reset when clat is stopped.
+        assertNull(nat.mIPv6Address);
         // Stacked interface removed notification arrives and is ignored.
         nat.interfaceRemoved(STACKED_IFACE);
         mLooper.dispatchNext();