Adding ability for driver handler behaviours to obtain services via the parent handler context.

Change-Id: Icc71a0c5f1fd50a4accd35777aeca7d0d5811bbf

@@ -15,6 +15,9 @@
  */
 package org.onosproject.net.driver;
 
+import org.onlab.osgi.DefaultServiceDirectory;
+import org.onlab.osgi.ServiceDirectory;
+
 import static com.google.common.base.MoreObjects.toStringHelper;
 
 /**
@@ -24,6 +27,9 @@ public class DefaultDriverHandler implements DriverHandler {
 
     private final DefaultDriverData data;
 
+    // Reference to service directory to provide run-time context.
+    protected static ServiceDirectory serviceDirectory = new DefaultServiceDirectory();
+
     /**
      * Creates new driver handler with the attached driver data.
      *
@@ -49,10 +55,13 @@ public class DefaultDriverHandler implements DriverHandler {
     }
 
     @Override
+    public <T> T get(Class<T> serviceClass) {
+        return serviceDirectory.get(serviceClass);
+    }
+
+    @Override
     public String toString() {
-        return toStringHelper(this)
-                .add("data", data)
-                .toString();
+        return toStringHelper(this).add("data", data).toString();
     }
 
 }

@@ -43,4 +43,15 @@ public interface DriverHandler {
      */
     <T extends Behaviour> T behaviour(Class<T> behaviourClass);
 
+    /**
+     * Returns the reference to the implementation of the specified service.
+     * Provides access to run-time context.
+     *
+     * @param serviceClass service class
+     * @param <T>          type of service
+     * @return service implementation
+     * @throws org.onlab.osgi.ServiceNotFoundException if service is unavailable
+     */
+    <T> T get(Class<T> serviceClass);
+
 }