Treat optimistic addresses as global preferred.
If the kernel sends notification of an optimistic address then
treat is a useable address (isGlobalPreferred()).
Note that addresses flagged as IFA_F_OPTIMISTIC are
simultaneously flagged as IFA_F_TENTATIVE (when the tentative
state has cleared either DAD has succeeded or failed, and both
flags are cleared regardless).
Additionally: do not consider RFC 4193 ULA addresses sufficient
for "global preffered". They are, by definition, of global scope
but not sufficient for global reachability.
Bug: 17769720
Change-Id: I759623b28fd52758f2d4d76d167f3cafd9319d6a
diff --git a/core/java/android/net/LinkAddress.java b/core/java/android/net/LinkAddress.java
index c387055..384ab1c 100644
--- a/core/java/android/net/LinkAddress.java
+++ b/core/java/android/net/LinkAddress.java
@@ -21,12 +21,14 @@
import android.util.Pair;
import java.net.Inet4Address;
+import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.InterfaceAddress;
import java.net.UnknownHostException;
import static android.system.OsConstants.IFA_F_DADFAILED;
import static android.system.OsConstants.IFA_F_DEPRECATED;
+import static android.system.OsConstants.IFA_F_OPTIMISTIC;
import static android.system.OsConstants.IFA_F_TENTATIVE;
import static android.system.OsConstants.RT_SCOPE_HOST;
import static android.system.OsConstants.RT_SCOPE_LINK;
@@ -93,6 +95,20 @@
}
/**
+ * Utility function to check if |address| is a Unique Local IPv6 Unicast Address
+ * (a.k.a. "ULA"; RFC 4193).
+ *
+ * Per RFC 4193 section 8, fc00::/7 identifies these addresses.
+ */
+ private boolean isIPv6ULA() {
+ if (address != null && address instanceof Inet6Address) {
+ byte[] bytes = address.getAddress();
+ return ((bytes[0] & (byte)0xfc) == (byte)0xfc);
+ }
+ return false;
+ }
+
+ /**
* Utility function for the constructors.
*/
private void init(InetAddress address, int prefixLength, int flags, int scope) {
@@ -268,8 +284,16 @@
* @hide
*/
public boolean isGlobalPreferred() {
+ /**
+ * Note that addresses flagged as IFA_F_OPTIMISTIC are
+ * simultaneously flagged as IFA_F_TENTATIVE (when the tentative
+ * state has cleared either DAD has succeeded or failed, and both
+ * flags are cleared regardless).
+ */
return (scope == RT_SCOPE_UNIVERSE &&
- (flags & (IFA_F_DADFAILED | IFA_F_DEPRECATED | IFA_F_TENTATIVE)) == 0L);
+ !isIPv6ULA() &&
+ (flags & (IFA_F_DADFAILED | IFA_F_DEPRECATED)) == 0L &&
+ ((flags & IFA_F_TENTATIVE) == 0L || (flags & IFA_F_OPTIMISTIC) != 0L));
}
/**
diff --git a/core/tests/coretests/src/android/net/LinkAddressTest.java b/core/tests/coretests/src/android/net/LinkAddressTest.java
index 7bc3974..adf8d95 100644
--- a/core/tests/coretests/src/android/net/LinkAddressTest.java
+++ b/core/tests/coretests/src/android/net/LinkAddressTest.java
@@ -33,8 +33,11 @@
import static android.test.MoreAsserts.assertNotEqual;
import android.test.suitebuilder.annotation.SmallTest;
+import static android.system.OsConstants.IFA_F_DADFAILED;
import static android.system.OsConstants.IFA_F_DEPRECATED;
+import static android.system.OsConstants.IFA_F_OPTIMISTIC;
import static android.system.OsConstants.IFA_F_PERMANENT;
+import static android.system.OsConstants.IFA_F_TEMPORARY;
import static android.system.OsConstants.IFA_F_TENTATIVE;
import static android.system.OsConstants.RT_SCOPE_HOST;
import static android.system.OsConstants.RT_SCOPE_LINK;
@@ -340,4 +343,73 @@
l = new LinkAddress(V4 + "/28", IFA_F_PERMANENT, RT_SCOPE_LINK);
assertParcelingIsLossless(l);
}
+
+ private void assertGlobalPreferred(LinkAddress l, String msg) {
+ assertTrue(msg, l.isGlobalPreferred());
+ }
+
+ private void assertNotGlobalPreferred(LinkAddress l, String msg) {
+ assertFalse(msg, l.isGlobalPreferred());
+ }
+
+ public void testIsGlobalPreferred() {
+ LinkAddress l;
+
+ l = new LinkAddress(V4_ADDRESS, 32, 0, RT_SCOPE_UNIVERSE);
+ assertGlobalPreferred(l, "v4,global,noflags");
+
+ l = new LinkAddress("10.10.1.7/23", 0, RT_SCOPE_UNIVERSE);
+ assertGlobalPreferred(l, "v4-rfc1918,global,noflags");
+
+ l = new LinkAddress("10.10.1.7/23", 0, RT_SCOPE_SITE);
+ assertNotGlobalPreferred(l, "v4-rfc1918,site-local,noflags");
+
+ l = new LinkAddress("127.0.0.7/8", 0, RT_SCOPE_HOST);
+ assertNotGlobalPreferred(l, "v4-localhost,node-local,noflags");
+
+ l = new LinkAddress(V6_ADDRESS, 64, 0, RT_SCOPE_UNIVERSE);
+ assertGlobalPreferred(l, "v6,global,noflags");
+
+ l = new LinkAddress(V6_ADDRESS, 64, IFA_F_PERMANENT, RT_SCOPE_UNIVERSE);
+ assertGlobalPreferred(l, "v6,global,permanent");
+
+ // IPv6 ULAs are not acceptable "global preferred" addresses.
+ l = new LinkAddress("fc12::1/64", 0, RT_SCOPE_UNIVERSE);
+ assertNotGlobalPreferred(l, "v6,ula1,noflags");
+
+ l = new LinkAddress("fd34::1/64", 0, RT_SCOPE_UNIVERSE);
+ assertNotGlobalPreferred(l, "v6,ula2,noflags");
+
+ l = new LinkAddress(V6_ADDRESS, 64, IFA_F_TEMPORARY, RT_SCOPE_UNIVERSE);
+ assertGlobalPreferred(l, "v6,global,tempaddr");
+
+ l = new LinkAddress(V6_ADDRESS, 64, (IFA_F_TEMPORARY|IFA_F_DADFAILED),
+ RT_SCOPE_UNIVERSE);
+ assertNotGlobalPreferred(l, "v6,global,tempaddr+dadfailed");
+
+ l = new LinkAddress(V6_ADDRESS, 64, (IFA_F_TEMPORARY|IFA_F_DEPRECATED),
+ RT_SCOPE_UNIVERSE);
+ assertNotGlobalPreferred(l, "v6,global,tempaddr+deprecated");
+
+ l = new LinkAddress(V6_ADDRESS, 64, IFA_F_TEMPORARY, RT_SCOPE_SITE);
+ assertNotGlobalPreferred(l, "v6,site-local,tempaddr");
+
+ l = new LinkAddress(V6_ADDRESS, 64, IFA_F_TEMPORARY, RT_SCOPE_LINK);
+ assertNotGlobalPreferred(l, "v6,link-local,tempaddr");
+
+ l = new LinkAddress(V6_ADDRESS, 64, IFA_F_TEMPORARY, RT_SCOPE_HOST);
+ assertNotGlobalPreferred(l, "v6,node-local,tempaddr");
+
+ l = new LinkAddress("::1/128", IFA_F_PERMANENT, RT_SCOPE_HOST);
+ assertNotGlobalPreferred(l, "v6-localhost,node-local,permanent");
+
+ l = new LinkAddress(V6_ADDRESS, 64, (IFA_F_TEMPORARY|IFA_F_TENTATIVE),
+ RT_SCOPE_UNIVERSE);
+ assertNotGlobalPreferred(l, "v6,global,tempaddr+tentative");
+
+ l = new LinkAddress(V6_ADDRESS, 64,
+ (IFA_F_TEMPORARY|IFA_F_TENTATIVE|IFA_F_OPTIMISTIC),
+ RT_SCOPE_UNIVERSE);
+ assertGlobalPreferred(l, "v6,global,tempaddr+optimistic");
+ }
}