(re)define the definition of "provisioned"

Specifically:

    [1] provide a hasIPv4(), and
    [2] a hasIPv6()

each of which requires an IP address, a default route, and
address-family-specific DNS servers to evaluate to true.

Additionally:

    [3] redefine isProvisioned() to return the logical OR
        of [1] and [2] above.

Any external caller can still use any of the has*() methods to
construct its own, different definition of "provisioned".

Bug: 17769720
Change-Id: Ia692fb8508484ff403d3920c94d0e1db4563f807

core/java/android/net/LinkProperties.java

@@ -675,17 +675,38 @@ public final class LinkProperties implements Parcelable {
     }
 
     /**
-     * Returns true if this link is provisioned for global connectivity. For IPv6, this requires an
+     * Returns true if this link is provisioned for global IPv4 connectivity.
-     * IP address, default route, and DNS server. For IPv4, this requires only an IPv4 address,
+     * This requires an IP address, default route, and DNS server.
-     * because WifiStateMachine accepts static configurations that only specify an address but not
+     *
-     * DNS servers or a default route.
+     * @return {@code true} if the link is provisioned, {@code false} otherwise.
+     */
+    private boolean hasIPv4() {
+        return (hasIPv4Address() &&
+                hasIPv4DefaultRoute() &&
+                hasIPv4DnsServer());
+    }
+
+    /**
+     * Returns true if this link is provisioned for global IPv6 connectivity.
+     * This requires an IP address, default route, and DNS server.
+     *
+     * @return {@code true} if the link is provisioned, {@code false} otherwise.
+     */
+    private boolean hasIPv6() {
+        return (hasGlobalIPv6Address() &&
+                hasIPv6DefaultRoute() &&
+                hasIPv6DnsServer());
+    }
+
+    /**
+     * Returns true if this link is provisioned for global connectivity,
+     * for at least one Internet Protocol family.
      *
      * @return {@code true} if the link is provisioned, {@code false} otherwise.
      * @hide
      */
     public boolean isProvisioned() {
-        return (hasIPv4Address() ||
+        return (hasIPv4() || hasIPv6());
-                (hasGlobalIPv6Address() && hasIPv6DefaultRoute() && hasIPv6DnsServer()));
     }
 
     /**

core/tests/coretests/src/android/net/LinkPropertiesTest.java

@@ -31,8 +31,10 @@ public class LinkPropertiesTest extends TestCase {
             "2001:0db8:85a3:0000:0000:8a2e:0370:7334");
     private static InetAddress DNS1 = NetworkUtils.numericToInetAddress("75.208.7.1");
     private static InetAddress DNS2 = NetworkUtils.numericToInetAddress("69.78.7.1");
+    private static InetAddress DNS6 = NetworkUtils.numericToInetAddress("2001:4860:4860::8888");
     private static InetAddress GATEWAY1 = NetworkUtils.numericToInetAddress("75.208.8.1");
     private static InetAddress GATEWAY2 = NetworkUtils.numericToInetAddress("69.78.8.1");
+    private static InetAddress GATEWAY6 = NetworkUtils.numericToInetAddress("fe80::6:0000:613");
     private static String NAME = "qmi0";
     private static int MTU = 1500;
 
@@ -453,4 +455,47 @@ public class LinkPropertiesTest extends TestCase {
         lp2.setLinkAddresses(lp.getLinkAddresses());
         assertTrue(lp.equals(lp));
     }
+
+    @SmallTest
+    public void testIsProvisioned() {
+        LinkProperties lp4 = new LinkProperties();
+        assertFalse("v4only:empty", lp4.isProvisioned());
+        lp4.addLinkAddress(LINKADDRV4);
+        assertFalse("v4only:addr-only", lp4.isProvisioned());
+        lp4.addDnsServer(DNS1);
+        assertFalse("v4only:addr+dns", lp4.isProvisioned());
+        lp4.addRoute(new RouteInfo(GATEWAY1));
+        assertTrue("v4only:addr+dns+route", lp4.isProvisioned());
+
+        LinkProperties lp6 = new LinkProperties();
+        assertFalse("v6only:empty", lp6.isProvisioned());
+        lp6.addLinkAddress(LINKADDRV6LINKLOCAL);
+        assertFalse("v6only:fe80-only", lp6.isProvisioned());
+        lp6.addDnsServer(DNS6);
+        assertFalse("v6only:fe80+dns", lp6.isProvisioned());
+        lp6.addRoute(new RouteInfo(GATEWAY6));
+        assertFalse("v6only:fe80+dns+route", lp6.isProvisioned());
+        lp6.addLinkAddress(LINKADDRV6);
+        assertTrue("v6only:fe80+global+dns+route", lp6.isProvisioned());
+        lp6.removeLinkAddress(LINKADDRV6LINKLOCAL);
+        assertTrue("v6only:global+dns+route", lp6.isProvisioned());
+
+        LinkProperties lp46 = new LinkProperties();
+        lp46.addLinkAddress(LINKADDRV4);
+        lp46.addLinkAddress(LINKADDRV6);
+        lp46.addDnsServer(DNS1);
+        lp46.addDnsServer(DNS6);
+        assertFalse("dualstack:missing-routes", lp46.isProvisioned());
+        lp46.addRoute(new RouteInfo(GATEWAY1));
+        assertTrue("dualstack:v4-provisioned", lp46.isProvisioned());
+        lp6.addRoute(new RouteInfo(GATEWAY6));
+        assertTrue("dualstack:both-provisioned", lp46.isProvisioned());
+
+        // A link with an IPv6 address and default route, but IPv4 DNS server.
+        LinkProperties mixed = new LinkProperties();
+        mixed.addLinkAddress(LINKADDRV6);
+        mixed.addDnsServer(DNS1);
+        mixed.addRoute(new RouteInfo(GATEWAY6));
+        assertFalse("mixed:addr6+route6+dns4", mixed.isProvisioned());
+    }
 }