Merge "Support changing the NAT64 prefix without removing it."
diff --git a/services/core/java/com/android/server/connectivity/Nat464Xlat.java b/services/core/java/com/android/server/connectivity/Nat464Xlat.java
index 741cb5b..e6b2d26 100644
--- a/services/core/java/com/android/server/connectivity/Nat464Xlat.java
+++ b/services/core/java/com/android/server/connectivity/Nat464Xlat.java
@@ -81,6 +81,9 @@
RUNNING, // start() called, and the stacked iface is known to be up.
}
+ /** NAT64 prefix currently in use. Only valid in STARTING or RUNNING states. */
+ private IpPrefix mNat64PrefixInUse;
+ /** NAT64 prefix (if any) discovered from DNS via RFC 7050. */
private IpPrefix mNat64PrefixFromDns;
private String mBaseIface;
private String mIface;
@@ -178,9 +181,10 @@
return;
}
+ mNat64PrefixInUse = getNat64Prefix();
String addrStr = null;
try {
- addrStr = mNetd.clatdStart(baseIface, getNat64Prefix().toString());
+ addrStr = mNetd.clatdStart(baseIface, mNat64PrefixInUse.toString());
} catch (RemoteException | ServiceSpecificException e) {
Slog.e(TAG, "Error starting clatd on " + baseIface + ": " + e);
}
@@ -211,12 +215,13 @@
} catch (RemoteException | IllegalStateException e) {
Slog.e(TAG, "Error unregistering clatd observer on " + mBaseIface + ": " + e);
}
+ mNat64PrefixInUse = null;
mIface = null;
mBaseIface = null;
if (requiresClat(mNetwork)) {
mState = State.DISCOVERING;
} else {
- stopPrefixDiscovery();
+ stopPrefixDiscovery(); // Enters IDLE state.
}
}
@@ -274,19 +279,32 @@
private void startPrefixDiscovery() {
try {
mDnsResolver.startPrefix64Discovery(getNetId());
- mState = State.DISCOVERING;
} catch (RemoteException | ServiceSpecificException e) {
Slog.e(TAG, "Error starting prefix discovery on netId " + getNetId() + ": " + e);
}
+ mState = State.DISCOVERING;
}
private void stopPrefixDiscovery() {
try {
mDnsResolver.stopPrefix64Discovery(getNetId());
- mState = State.IDLE;
} catch (RemoteException | ServiceSpecificException e) {
Slog.e(TAG, "Error stopping prefix discovery on netId " + getNetId() + ": " + e);
}
+ mState = State.IDLE;
+ }
+
+ private void maybeHandleNat64PrefixChange() {
+ final IpPrefix newPrefix = getNat64Prefix();
+ if (!Objects.equals(mNat64PrefixInUse, newPrefix)) {
+ Slog.d(TAG, "NAT64 prefix changed from " + mNat64PrefixInUse + " to "
+ + newPrefix);
+ stop();
+ // It's safe to call update here, even though this method is called from update, because
+ // stop() is guaranteed to have moved out of STARTING and RUNNING, which are the only
+ // states in which this method can be called.
+ update();
+ }
}
/**
@@ -325,11 +343,11 @@
// Stop clatd and go back into DISCOVERING or idle.
if (!shouldStartClat(mNetwork)) {
stop();
+ break;
}
+ // Only necessary while clat is actually started.
+ maybeHandleNat64PrefixChange();
break;
- // TODO: support the NAT64 prefix changing after it's been discovered. There is
- // no need to support this at the moment because it cannot happen without
- // changes to the Dns64Configuration code in netd.
}
}
@@ -347,6 +365,8 @@
* has no idea that 464xlat is running on top of it.
*/
public void fixupLinkProperties(@NonNull LinkProperties oldLp, @NonNull LinkProperties lp) {
+ // This must be done even if clatd is not running, because otherwise shouldStartClat would
+ // never return true.
lp.setNat64Prefix(getNat64Prefix());
if (!isRunning()) {
diff --git a/tests/net/java/com/android/server/ConnectivityServiceTest.java b/tests/net/java/com/android/server/ConnectivityServiceTest.java
index b864e37..dad0363 100644
--- a/tests/net/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/net/java/com/android/server/ConnectivityServiceTest.java
@@ -5969,6 +5969,9 @@
final LinkAddress myIpv6 = new LinkAddress("2001:db8:1::1/64");
final String kNat64PrefixString = "2001:db8:64:64:64:64::";
final IpPrefix kNat64Prefix = new IpPrefix(InetAddress.getByName(kNat64PrefixString), 96);
+ final String kOtherNat64PrefixString = "64:ff9b::";
+ final IpPrefix kOtherNat64Prefix = new IpPrefix(
+ InetAddress.getByName(kOtherNat64PrefixString), 96);
final RouteInfo defaultRoute = new RouteInfo((IpPrefix) null, myIpv6.getAddress(),
MOBILE_IFNAME);
final RouteInfo ipv6Subnet = new RouteInfo(myIpv6, null, MOBILE_IFNAME);
@@ -6082,6 +6085,24 @@
}
reset(mMockNetd);
+ // Change the NAT64 prefix without first removing it.
+ // Expect clatd to be stopped and started with the new prefix.
+ mService.mNetdEventCallback.onNat64PrefixEvent(cellNetId, true /* added */,
+ kOtherNat64PrefixString, 96);
+ networkCallback.expectLinkPropertiesThat(mCellNetworkAgent,
+ (lp) -> lp.getStackedLinks().size() == 0);
+ verify(mMockNetd, times(1)).clatdStop(MOBILE_IFNAME);
+ assertRoutesRemoved(cellNetId, stackedDefault);
+
+ verify(mMockNetd, times(1)).clatdStart(MOBILE_IFNAME, kOtherNat64Prefix.toString());
+ networkCallback.expectLinkPropertiesThat(mCellNetworkAgent,
+ (lp) -> lp.getNat64Prefix().equals(kOtherNat64Prefix));
+ clat.interfaceLinkStateChanged(CLAT_PREFIX + MOBILE_IFNAME, true);
+ networkCallback.expectLinkPropertiesThat(mCellNetworkAgent,
+ (lp) -> lp.getStackedLinks().size() == 1);
+ assertRoutesAdded(cellNetId, stackedDefault);
+ reset(mMockNetd);
+
// Add ipv4 address, expect that clatd and prefix discovery are stopped and stacked
// linkproperties are cleaned up.
cellLp.addLinkAddress(myIpv4);
@@ -6096,7 +6117,7 @@
networkCallback.expectCallback(CallbackEntry.LINK_PROPERTIES_CHANGED, mCellNetworkAgent);
LinkProperties actualLpAfterIpv4 = mCm.getLinkProperties(mCellNetworkAgent.getNetwork());
LinkProperties expected = new LinkProperties(cellLp);
- expected.setNat64Prefix(kNat64Prefix);
+ expected.setNat64Prefix(kOtherNat64Prefix);
assertEquals(expected, actualLpAfterIpv4);
assertEquals(0, actualLpAfterIpv4.getStackedLinks().size());
assertRoutesRemoved(cellNetId, stackedDefault);
@@ -6115,7 +6136,7 @@
// Stopping prefix discovery causes netd to tell us that the NAT64 prefix is gone.
mService.mNetdEventCallback.onNat64PrefixEvent(cellNetId, false /* added */,
- kNat64PrefixString, 96);
+ kOtherNat64PrefixString, 96);
networkCallback.expectLinkPropertiesThat(mCellNetworkAgent,
(lp) -> lp.getNat64Prefix() == null);