nwfilter: Fix memory leak in the ebtables subdriver

Call shutdown functions for all subcomponents in nwfilterDriverShutdown.

Make sure that this shutdown functions can safely be called multiple times
and independent from the actual subcomponents state.

src/conf/nwfilter_conf.c

@@ -125,6 +125,7 @@ struct int_map {
  * only one filter update allowed
  */
 static virMutex updateMutex;
+static bool initialized = false;
 
 void
 virNWFilterLockFilterUpdates(void) {
@@ -2971,6 +2972,8 @@ int virNWFilterConfLayerInit(virHashIterator domUpdateCB)
 {
     virNWFilterDomainFWUpdateCB = domUpdateCB;
 
+    initialized = true;
+
     if (virMutexInitRecursive(&updateMutex))
         return 1;
 
@@ -2980,7 +2983,12 @@ int virNWFilterConfLayerInit(virHashIterator domUpdateCB)
 
 void virNWFilterConfLayerShutdown(void)
 {
+    if (!initialized)
+        return;
+
     virMutexDestroy(&updateMutex);
+
+    initialized = false;
 }
 
 

src/nwfilter/nwfilter_driver.c

@@ -199,6 +199,8 @@ nwfilterDriverShutdown(void) {
     if (!driverState)
         return -1;
 
+    virNWFilterConfLayerShutdown();
+    virNWFilterTechDriversShutdown();
     virNWFilterLearnShutdown();
 
     nwfilterDriverLock(driverState);

src/nwfilter/nwfilter_learnipaddr.c

@@ -873,7 +873,10 @@ virNWFilterLearnThreadsTerminate(bool allowNewThreads) {
  * Shutdown of this layer
  */
 void
-virNWFilterLearnShutdown(void) {
+virNWFilterLearnShutdown(void)
+{
+    if (!pendingLearnReq)
+        return;
 
     virNWFilterLearnThreadsTerminate(false);