Merge branch 'variadic-enumerators'

This adds several changes to enumerator_t and linked_list_t to improve
portability.  In particular to Apple's ARM64 iOS platform, whose calling
convention for variadic and regular functions are different.  This means
that assigning a non-variadic function to a variadic function pointer,
as we did with our enumerator_t::enumerate() implementations and several
callbacks, will result in crashes as the called function will access the
arguments differently than the caller provided them.

To avoid this issue the enumerator_t interface is now fully variadic.
A new mandatory method is added, venumerate(), that takes a va_list with
the arguments provided while enumerating.  enumerate() is replaced with
a generic implementation that prepares a va_list and calls the
enumerator's venumerate() implementation.  As this allows passing the
arguments of one enumerator to another it avoids the five pointer hack
used by enumerator_create_nested() and enumerator_create_cleaner().
To simplify the implementation of venumerate() a helper macro is provided
that assigns values from a given va_list to local variables.

The signature of the callback passed to enumerator_create_filter() has
also changed significantly.  It's now required to enumerate over the
original enumerator in the callback as this avoids the previous in/out
pointer hack. The arguments to the outer enumerator are provided in a
va_list.

Similar changes to avoid such five pointer hacks affect the signatures
of the callbacks for linked_list_t's invoke_function() and find_first()
methods.  For the latter the return type also changed from status_t to
bool, which is important as SUCCESS is defined as 0, so checks for ==
SUCCESS will now fail.

1 files changed, 12 insertions, 13 deletions

diff --git a/src/libcharon/attributes/attribute_manager.c b/src/libcharon/attributes/attribute_manager.c
index 2ab7ed118..3a4a21a02 100644
--- a/src/libcharon/attributes/attribute_manager.c
+++ b/src/libcharon/attributes/attribute_manager.c
@@ -237,14 +237,14 @@ typedef struct {
 	linked_list_t *vips;
 } initiator_enumerator_t;
 
-/**
- * Enumerator implementation for initiator attributes
- */
-static bool initiator_enumerate(initiator_enumerator_t *this,
-								attribute_handler_t **handler,
-								configuration_attribute_type_t *type,
-								chunk_t *value)
+METHOD(enumerator_t, initiator_enumerate, bool,
+	initiator_enumerator_t *this, va_list args)
 {
+	configuration_attribute_type_t *type;
+	attribute_handler_t **handler;
+	chunk_t *value;
+
+	VA_ARGS_VGET(args, handler, type, value);
 	/* enumerate inner attributes using outer handler enumerator */
 	while (!this->inner || !this->inner->enumerate(this->inner, type, value))
 	{
@@ -261,10 +261,8 @@ static bool initiator_enumerate(initiator_enumerator_t *this,
 	return TRUE;
 }
 
-/**
- * Cleanup function of initiator attribute enumerator
- */
-static void initiator_destroy(initiator_enumerator_t *this)
+METHOD(enumerator_t, initiator_destroy, void,
+	initiator_enumerator_t *this)
 {
 	this->this->lock->unlock(this->this->lock);
 	this->outer->destroy(this->outer);
@@ -281,8 +279,9 @@ METHOD(attribute_manager_t, create_initiator_enumerator, enumerator_t*,
 
 	INIT(enumerator,
 		.public = {
-			.enumerate = (void*)initiator_enumerate,
-			.destroy = (void*)initiator_destroy,
+			.enumerate = enumerator_enumerate_default,
+			.venumerate = _initiator_enumerate,
+			.destroy = _initiator_destroy,
 		},
 		.this = this,
 		.ike_sa = ike_sa,