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, 10 insertions, 2 deletions

diff --git a/src/libcharon/plugins/eap_dynamic/eap_dynamic.c b/src/libcharon/plugins/eap_dynamic/eap_dynamic.c
index 83ccd3a8a..204fb317d 100644
--- a/src/libcharon/plugins/eap_dynamic/eap_dynamic.c
+++ b/src/libcharon/plugins/eap_dynamic/eap_dynamic.c
@@ -69,6 +69,15 @@ static bool entry_matches(eap_vendor_type_t *item, eap_vendor_type_t *other)
 	return item->type == other->type && item->vendor == other->vendor;
 }
 
+CALLBACK(entry_matches_cb, bool,
+	eap_vendor_type_t *item, va_list args)
+{
+	eap_vendor_type_t *other;
+
+	VA_ARGS_VGET(args, other);
+	return entry_matches(item, other);
+}
+
 /**
  * Load the given EAP method
  */
@@ -121,8 +130,7 @@ static void select_method(private_eap_dynamic_t *this)
 	{
 		if (inner)
 		{
-			if (inner->find_first(inner, (void*)entry_matches,
-								  NULL, entry) != SUCCESS)
+			if (!inner->find_first(inner, entry_matches_cb, NULL, entry))
 			{
 				if (entry->vendor)
 				{