Modify LinkProperties address update methods.

1. Make addLinkAddress a no-op if the address already exists.
2. Make addLinkAddress, addStackedLink and removeStackedLink
   return a boolean indicating whether something changed.
3. Add a removeLinkAddress method (currently there is no way of
   removing an address).
3. Move hasIPv6Address from ConnectivityService to
   LinkProperties, where it belongs.

Bug: 9625448
Bug: 10232006
Change-Id: If641d0198432a7a505e358c059171f25bc9f13d5

core/java/android/net/LinkProperties.java

@@ -23,6 +23,7 @@ import android.text.TextUtils;
 
 import java.net.InetAddress;
 import java.net.Inet4Address;
+import java.net.Inet6Address;
 
 import java.net.UnknownHostException;
 import java.util.ArrayList;
@@ -153,8 +154,28 @@ public class LinkProperties implements Parcelable {
         return addresses;
     }
 
-    public void addLinkAddress(LinkAddress address) {
-        if (address != null) mLinkAddresses.add(address);
+    /**
+     * Adds a link address if it does not exist, or update it if it does.
+     * @param address The {@code LinkAddress} to add.
+     * @return true if the address was added, false if it already existed.
+     */
+    public boolean addLinkAddress(LinkAddress address) {
+        // TODO: when the LinkAddress has other attributes beyond the
+        // address and the prefix length, update them here.
+        if (address != null && !mLinkAddresses.contains(address)) {
+            mLinkAddresses.add(address);
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Removes a link address.
+     * @param address The {@code LinkAddress} to remove.
+     * @return true if the address was removed, false if it did not exist.
+     */
+    public boolean removeLinkAddress(LinkAddress toRemove) {
+        return mLinkAddresses.remove(toRemove);
     }
 
     /**
@@ -245,11 +266,14 @@ public class LinkProperties implements Parcelable {
      * of stacked links. If link is null, nothing changes.
      *
      * @param link The link to add.
+     * @return true if the link was stacked, false otherwise.
      */
-    public void addStackedLink(LinkProperties link) {
+    public boolean addStackedLink(LinkProperties link) {
         if (link != null && link.getInterfaceName() != null) {
             mStackedLinks.put(link.getInterfaceName(), link);
+            return true;
         }
+        return false;
     }
 
     /**
@@ -258,12 +282,15 @@ public class LinkProperties implements Parcelable {
      * If there a stacked link with the same interfacename as link, it is
      * removed. Otherwise, nothing changes.
      *
-     * @param link The link to add.
+     * @param link The link to remove.
+     * @return true if the link was removed, false otherwise.
      */
-    public void removeStackedLink(LinkProperties link) {
+    public boolean removeStackedLink(LinkProperties link) {
         if (link != null && link.getInterfaceName() != null) {
-            mStackedLinks.remove(link.getInterfaceName());
+            LinkProperties removed = mStackedLinks.remove(link.getInterfaceName());
+            return removed != null;
         }
+        return false;
     }
 
     /**
@@ -339,6 +366,20 @@ public class LinkProperties implements Parcelable {
         return false;
     }
 
+    /**
+     * Returns true if this link has an IPv6 address.
+     *
+     * @return {@code true} if there is an IPv6 address, {@code false} otherwise.
+     */
+    public boolean hasIPv6Address() {
+        for (LinkAddress address : mLinkAddresses) {
+          if (address.getAddress() instanceof Inet6Address) {
+            return true;
+          }
+        }
+        return false;
+    }
+
     /**
      * Compares this {@code LinkProperties} interface name against the target
      *

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

@@ -306,5 +306,61 @@ public class LinkPropertiesTest extends TestCase {
         for (LinkProperties link : rmnet0.getStackedLinks()) {
             assertFalse("newname".equals(link.getInterfaceName()));
         }
+
+        assertTrue(rmnet0.removeStackedLink(clat4));
+        assertEquals(0, rmnet0.getStackedLinks().size());
+        assertEquals(1, rmnet0.getAddresses().size());
+        assertEquals(1, rmnet0.getLinkAddresses().size());
+        assertEquals(1, rmnet0.getAllAddresses().size());
+        assertEquals(1, rmnet0.getAllLinkAddresses().size());
+
+        assertFalse(rmnet0.removeStackedLink(clat4));
+    }
+
+    @SmallTest
+    public void testAddressMethods() {
+        LinkProperties lp = new LinkProperties();
+
+        // No addresses.
+        assertFalse(lp.hasIPv4Address());
+        assertFalse(lp.hasIPv6Address());
+
+        // Addresses on stacked links don't count.
+        LinkProperties stacked = new LinkProperties();
+        stacked.setInterfaceName("stacked");
+        lp.addStackedLink(stacked);
+        stacked.addLinkAddress(LINKADDRV4);
+        stacked.addLinkAddress(LINKADDRV6);
+        assertTrue(stacked.hasIPv4Address());
+        assertTrue(stacked.hasIPv6Address());
+        assertFalse(lp.hasIPv4Address());
+        assertFalse(lp.hasIPv6Address());
+        lp.removeStackedLink(stacked);
+        assertFalse(lp.hasIPv4Address());
+        assertFalse(lp.hasIPv6Address());
+
+        // Addresses on the base link.
+        // Check the return values of hasIPvXAddress and ensure the add/remove methods return true
+        // iff something changes.
+        assertTrue(lp.addLinkAddress(LINKADDRV6));
+        assertFalse(lp.hasIPv4Address());
+        assertTrue(lp.hasIPv6Address());
+
+        assertTrue(lp.removeLinkAddress(LINKADDRV6));
+        assertTrue(lp.addLinkAddress(LINKADDRV4));
+        assertTrue(lp.hasIPv4Address());
+        assertFalse(lp.hasIPv6Address());
+
+        assertTrue(lp.addLinkAddress(LINKADDRV6));
+        assertTrue(lp.hasIPv4Address());
+        assertTrue(lp.hasIPv6Address());
+
+        // Adding an address twice has no effect.
+        // Removing an address that's not present has no effect.
+        assertFalse(lp.addLinkAddress(LINKADDRV4));
+        assertTrue(lp.hasIPv4Address());
+        assertTrue(lp.removeLinkAddress(LINKADDRV4));
+        assertFalse(lp.hasIPv4Address());
+        assertFalse(lp.removeLinkAddress(LINKADDRV4));
     }
 }

services/java/com/android/server/ConnectivityService.java

@@ -3982,8 +3982,8 @@ public class ConnectivityService extends IConnectivityManager.Stub {
                         // Get the type of addresses supported by this link
                         LinkProperties lp = mCs.getLinkProperties(
                                 ConnectivityManager.TYPE_MOBILE_HIPRI);
-                        boolean linkHasIpv4 = hasIPv4Address(lp);
-                        boolean linkHasIpv6 = hasIPv6Address(lp);
+                        boolean linkHasIpv4 = lp.hasIPv4Address();
+                        boolean linkHasIpv6 = lp.hasIPv6Address();
                         log("isMobileOk: linkHasIpv4=" + linkHasIpv4
                                 + " linkHasIpv6=" + linkHasIpv6);
 
@@ -4129,20 +4129,6 @@ public class ConnectivityService extends IConnectivityManager.Stub {
             }
         }
 
-        public boolean hasIPv4Address(LinkProperties lp) {
-            return lp.hasIPv4Address();
-        }
-
-        // Not implemented in LinkProperties, do it here.
-        public boolean hasIPv6Address(LinkProperties lp) {
-            for (LinkAddress address : lp.getLinkAddresses()) {
-              if (address.getAddress() instanceof Inet6Address) {
-                return true;
-              }
-            }
-            return false;
-        }
-
         private void log(String s) {
             Slog.d(ConnectivityService.TAG, "[" + CHECKMP_TAG + "] " + s);
         }