Change interface for enumerator_create_filter() callback

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

src/charon-nm/nm/nm_creds.c

@@ -120,48 +120,49 @@ typedef struct {
 	identification_t *id;
 } cert_data_t;
 
-/**
- * Destroy CA certificate enumerator data
- */
-static void cert_data_destroy(cert_data_t *data)
+CALLBACK(cert_data_destroy, void,
+	cert_data_t *data)
 {
 	data->this->lock->unlock(data->this->lock);
 	free(data);
 }
 
-/**
- * Filter function for certificates enumerator
- */
-static bool cert_filter(cert_data_t *data, certificate_t **in,
-						 certificate_t **out)
+CALLBACK(cert_filter, bool,
+	cert_data_t *data, enumerator_t *orig, va_list args)
 {
-	certificate_t *cert = *in;
+	certificate_t *cert, **out;
 	public_key_t *public;
 
-	public = cert->get_public_key(cert);
-	if (!public)
-	{
-		return FALSE;
-	}
-	if (data->key != KEY_ANY && public->get_type(public) != data->key)
-	{
-		public->destroy(public);
-		return FALSE;
-	}
-	if (data->id && data->id->get_type(data->id) == ID_KEY_ID &&
-		public->has_fingerprint(public, data->id->get_encoding(data->id)))
+	VA_ARGS_VGET(args, out);
+
+	while (orig->enumerate(orig, &cert))
 	{
+		public = cert->get_public_key(cert);
+		if (!public)
+		{
+			continue;
+		}
+		if (data->key != KEY_ANY && public->get_type(public) != data->key)
+		{
+			public->destroy(public);
+			continue;
+		}
+		if (data->id && data->id->get_type(data->id) == ID_KEY_ID &&
+			public->has_fingerprint(public, data->id->get_encoding(data->id)))
+		{
+			public->destroy(public);
+			*out = cert;
+			return TRUE;
+		}
 		public->destroy(public);
+		if (data->id && !cert->has_subject(cert, data->id))
+		{
+			continue;
+		}
 		*out = cert;
 		return TRUE;
 	}
-	public->destroy(public);
-	if (data->id && !cert->has_subject(cert, data->id))
-	{
-		return FALSE;
-	}
-	*out = cert;
-	return TRUE;
+	return FALSE;
 }
 
 /**
@@ -181,7 +182,7 @@ static enumerator_t *create_trusted_cert_enumerator(private_nm_creds_t *this,
 	this->lock->read_lock(this->lock);
 	return enumerator_create_filter(
 					this->certs->create_enumerator(this->certs),
-					(void*)cert_filter, data, (void*)cert_data_destroy);
+					cert_filter, data, cert_data_destroy);
 }
 
 METHOD(credential_set_t, create_cert_enumerator, enumerator_t*,

src/charon-nm/nm/nm_handler.c

@@ -113,13 +113,20 @@ METHOD(attribute_handler_t, create_attribute_enumerator, enumerator_t*,
 	return enumerator_create_empty();
 }
 
-/**
- * convert plain byte ptrs to handy chunk during enumeration
- */
-static bool filter_chunks(void* null, char **in, chunk_t *out)
+CALLBACK(filter_chunks, bool,
+	void *null, enumerator_t *orig, va_list args)
 {
-	*out = chunk_create(*in, 4);
-	return TRUE;
+	chunk_t *out;
+	char *ptr;
+
+	VA_ARGS_VGET(args, out);
+
+	if (orig->enumerate(orig, &ptr))
+	{
+		*out = chunk_create(ptr, 4);
+		return TRUE;
+	}
+	return FALSE;
 }
 
 METHOD(nm_handler_t, create_enumerator, enumerator_t*,
@@ -139,7 +146,7 @@ METHOD(nm_handler_t, create_enumerator, enumerator_t*,
 			return enumerator_create_empty();
 	}
 	return enumerator_create_filter(list->create_enumerator(list),
-						(void*)filter_chunks, NULL, NULL);
+									filter_chunks, NULL, NULL);
 }
 
 METHOD(nm_handler_t, reset, void,