Fix IP address cleanup on network disconnect

We used to bring down the interface on network disconnect
which would in turn clean up all the IP addresses.

The interface bringup/shutdown is now handled by wpa_supplicant.
Add netd interface for clearing all IP addresses

Bug: 4676254
Change-Id: I7e24c0ab2e4a412b8d61e9c33ce028966913aaf6
diff --git a/services/java/com/android/server/NetworkManagementService.java b/services/java/com/android/server/NetworkManagementService.java
index 2190b30..bb0c671 100644
--- a/services/java/com/android/server/NetworkManagementService.java
+++ b/services/java/com/android/server/NetworkManagementService.java
@@ -311,6 +311,18 @@
         }
     }
 
+    /* TODO: This is right now a IPv4 only function. Works for wifi which loses its
+       IPv6 addresses on interface down, but we need to do full clean up here */
+    public void clearInterfaceAddresses(String iface) throws IllegalStateException {
+         String cmd = String.format("interface clearaddrs %s", iface);
+        try {
+            mConnector.doCommand(cmd);
+        } catch (NativeDaemonConnectorException e) {
+            throw new IllegalStateException(
+                    "Unable to communicate with native daemon to interface clearallips - " + e);
+        }
+    }
+
     public void addRoute(String interfaceName, RouteInfo route) {
         modifyRoute(interfaceName, ADD, route);
     }