Change interface for enumerator_create_filter() callback

This avoids the unportable 5 pointer hack, but requires enumerating in
the callback.

src/libstrongswan/collections/enumerator.c

@@ -518,9 +518,9 @@ enumerator_t *enumerator_create_nested(enumerator_t *outer,
  */
 typedef struct {
 	enumerator_t public;
-	enumerator_t *unfiltered;
+	enumerator_t *orig;
 	void *data;
-	bool (*filter)(void *data, ...);
+	bool (*filter)(void*,enumerator_t*,va_list);
 	void (*destructor)(void *data);
 } filter_enumerator_t;
 
@@ -531,35 +531,28 @@ METHOD(enumerator_t, destroy_filter, void,
 	{
 		this->destructor(this->data);
 	}
-	this->unfiltered->destroy(this->unfiltered);
+	this->orig->destroy(this->orig);
 	free(this);
 }
 
 METHOD(enumerator_t, enumerate_filter, bool,
 	filter_enumerator_t *this, va_list args)
 {
-	void *i1, *i2, *i3, *i4, *i5;
-	void *o1, *o2, *o3, *o4, *o5;
+	bool result = FALSE;
 
-	/* FIXME: what happens if there are less than five arguments is not defined */
-	VA_ARGS_VGET(args, o1, o2, o3, o4, o5);
-
-	while (this->unfiltered->enumerate(this->unfiltered, &i1, &i2, &i3, &i4, &i5))
+	if (this->filter(this->data, this->orig, args))
 	{
-		if (this->filter(this->data, &i1, o1, &i2, o2, &i3, o3, &i4, o4, &i5, o5))
-		{
-			return TRUE;
-		}
+		result = TRUE;
 	}
-	return FALSE;
+	return result;
 }
 
 /*
  * Described in header
  */
-enumerator_t *enumerator_create_filter(enumerator_t *unfiltered,
-									   bool (*filter)(void *data, ...),
-									   void *data, void (*destructor)(void *data))
+enumerator_t *enumerator_create_filter(enumerator_t *orig,
+			bool (*filter)(void *data, enumerator_t *orig, va_list args),
+			void *data, void (*destructor)(void *data))
 {
 	filter_enumerator_t *this;
 
@@ -569,7 +562,7 @@ enumerator_t *enumerator_create_filter(enumerator_t *unfiltered,
 			.venumerate = _enumerate_filter,
 			.destroy = _destroy_filter,
 		},
-		.unfiltered = unfiltered,
+		.orig = orig,
 		.filter = filter,
 		.data = data,
 		.destructor = destructor,

src/libstrongswan/collections/enumerator.h

@@ -189,25 +189,24 @@ enumerator_t *enumerator_create_nested(enumerator_t *outer,
 					void *data, void (*destructor)(void *data));
 
 /**
- * Creates an enumerator which filters output of another enumerator.
+ * Creates an enumerator which filters/maps output of another enumerator.
  *
- * The filter function receives the user supplied "data" followed by a
- * unfiltered enumeration item, followed by an output pointer where to write
- * the filtered data. Then the next input/output pair follows.
- * It returns TRUE to deliver the
- * values to the caller of enumerate(), FALSE to filter this enumeration.
+ * The filter function receives the user supplied "data" followed by the
+ * original enumerator, followed by the arguments passed to the outer
+ * enumerator.  It returns TRUE to deliver the values assigned to these
+ * arguments to the caller of enumerate() and FALSE to end the enumeration.
+ * Filtering items is simple as the filter function may just skip enumerated
+ * items from the original enumerator.
  *
- * The variable argument list of enumeration values is limit to 5.
- *
- * @param unfiltered			unfiltered enumerator to wrap, gets destroyed
+ * @param orig					original enumerator to wrap, gets destroyed
  * @param filter				filter function
  * @param data					user data to supply to filter
  * @param destructor			destructor function to clean up data after use
  * @return						the filtered enumerator
  */
-enumerator_t *enumerator_create_filter(enumerator_t *unfiltered,
-					bool (*filter)(void *data, ...),
-					void *data, void (*destructor)(void *data));
+enumerator_t *enumerator_create_filter(enumerator_t *orig,
+				bool (*filter)(void *data, enumerator_t *orig, va_list args),
+				void *data, void (*destructor)(void *data));
 
 /**
  * Create an enumerator wrapper which does a cleanup on destroy.