Added a replace function to linked_list_t.

src/libstrongswan/utils/linked_list.c

@@ -476,6 +476,19 @@ METHOD(linked_list_t, insert_after, void,
 	insert_item_after(this, enumerator->current, item);
 }
 
+METHOD(linked_list_t, replace, void*,
+	   private_linked_list_t *this, private_enumerator_t *enumerator,
+	   void *item)
+{
+	void *old = NULL;
+	if (enumerator->current)
+	{
+		old = enumerator->current->value;
+		enumerator->current->value = item;
+	}
+	return old;
+}
+
 METHOD(linked_list_t, get_last, status_t,
 	   private_linked_list_t *this, void **item)
 {
@@ -722,6 +735,7 @@ linked_list_t *linked_list_create()
 			.insert_last = _insert_last,
 			.insert_after = (void*)_insert_after,
 			.insert_before = (void*)_insert_before,
+			.replace = (void*)_replace,
 			.remove_first = _remove_first,
 			.remove_last = _remove_last,
 			.remove = _remove_,

src/libstrongswan/utils/linked_list.h

@@ -125,6 +125,16 @@ struct linked_list_t {
 	void (*insert_after)(linked_list_t *this, enumerator_t *enumerator,
 						 void *item);
 
+	/**
+	 * Replaces the item the enumerator currently points to with the given item.
+	 *
+	 * @param enumerator	enumerator with position
+	 * @param item			item value to replace current item with
+	 * @return				current item or NULL if the enumerator is at an
+	 *						invalid position
+	 */
+	void *(*replace)(linked_list_t *this, enumerator_t *enumerator, void *item);
+
 	/**
 	 * Remove an item from the list where the enumerator points to.
 	 *