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.

4 files changed, 47 insertions, 22 deletions

diff --git a/src/libcharon/plugins/vici/suites/test_message.c b/src/libcharon/plugins/vici/suites/test_message.c
index 045e34fff..73bba239b 100644
--- a/src/libcharon/plugins/vici/suites/test_message.c
+++ b/src/libcharon/plugins/vici/suites/test_message.c
@@ -122,9 +122,14 @@ typedef struct {
 	endecode_test_t *next;
 } endecode_enum_t;
 
-static bool endecode_enumerate(endecode_enum_t *this, vici_type_t *type,
-							   char **name, chunk_t *data)
+METHOD(enumerator_t, endecode_enumerate, bool,
+	endecode_enum_t *this, va_list args)
 {
+	vici_type_t *type;
+	chunk_t *data;
+	char **name;
+
+	VA_ARGS_VGET(args, type, name, data);
 	if (this->next)
 	{
 		*type = this->next->type;
@@ -149,7 +154,8 @@ static enumerator_t *endecode_create_enumerator(endecode_test_t *test)
 
 	INIT(enumerator,
 		.public = {
-			.enumerate = (void*)endecode_enumerate,
+			.enumerate = enumerator_enumerate_default,
+			.venumerate = _endecode_enumerate,
 			.destroy = (void*)free,
 		},
 		.next = test,
diff --git a/src/libcharon/plugins/vici/vici_attribute.c b/src/libcharon/plugins/vici/vici_attribute.c
index 4e1fa9708..ab765fa14 100644
--- a/src/libcharon/plugins/vici/vici_attribute.c
+++ b/src/libcharon/plugins/vici/vici_attribute.c
@@ -184,16 +184,22 @@ METHOD(attribute_provider_t, release_address, bool,
 	return found;
 }
 
-/**
- * Filter mapping attribute_t to enumerated type/value arguments
- */
-static bool attr_filter(void *data, attribute_t **attr,
-						configuration_attribute_type_t *type,
-						void *in, chunk_t *value)
+CALLBACK(attr_filter, bool,
+	void *data, enumerator_t *orig, va_list args)
 {
-	*type = (*attr)->type;
-	*value = (*attr)->value;
-	return TRUE;
+	attribute_t *attr;
+	configuration_attribute_type_t *type;
+	chunk_t *value;
+
+	VA_ARGS_VGET(args, type, value);
+
+	if (orig->enumerate(orig, &attr))
+	{
+		*type = attr->type;
+		*value = attr->value;
+		return TRUE;
+	}
+	return FALSE;
 }
 
 /**
@@ -203,7 +209,7 @@ CALLBACK(create_nested, enumerator_t*,
 	pool_t *pool, void *this)
 {
 	return enumerator_create_filter(array_create_enumerator(pool->attrs),
-									(void*)attr_filter, NULL, NULL);
+									attr_filter, NULL, NULL);
 }
 
 /**
diff --git a/src/libcharon/plugins/vici/vici_config.c b/src/libcharon/plugins/vici/vici_config.c
index 3af67df94..0c355e3a0 100644
--- a/src/libcharon/plugins/vici/vici_config.c
+++ b/src/libcharon/plugins/vici/vici_config.c
@@ -141,13 +141,20 @@ METHOD(backend_t, create_peer_cfg_enumerator, enumerator_t*,
 									 (void*)this->lock->unlock, this->lock);
 }
 
-/**
- * Enumerator filter function for ike configs
- */
-static bool ike_filter(void *data, peer_cfg_t **in, ike_cfg_t **out)
+CALLBACK(ike_filter, bool,
+	void *data, enumerator_t *orig, va_list args)
 {
-	*out = (*in)->get_ike_cfg(*in);
-	return TRUE;
+	peer_cfg_t *cfg;
+	ike_cfg_t **out;
+
+	VA_ARGS_VGET(args, out);
+
+	if (orig->enumerate(orig, &cfg))
+	{
+		*out = cfg->get_ike_cfg(cfg);
+		return TRUE;
+	}
+	return FALSE;
 }
 
 METHOD(backend_t, create_ike_cfg_enumerator, enumerator_t*,
@@ -155,7 +162,7 @@ METHOD(backend_t, create_ike_cfg_enumerator, enumerator_t*,
 {
 	this->lock->read_lock(this->lock);
 	return enumerator_create_filter(this->conns->create_enumerator(this->conns),
-									(void*)ike_filter, this->lock,
+									ike_filter, this->lock,
 									(void*)this->lock->unlock);
 }
 
diff --git a/src/libcharon/plugins/vici/vici_message.c b/src/libcharon/plugins/vici/vici_message.c
index 58b896773..91d344994 100644
--- a/src/libcharon/plugins/vici/vici_message.c
+++ b/src/libcharon/plugins/vici/vici_message.c
@@ -135,11 +135,16 @@ typedef struct {
 } parse_enumerator_t;
 
 METHOD(enumerator_t, parse_enumerate, bool,
-	parse_enumerator_t *this, vici_type_t *out, char **name, chunk_t *value)
+	parse_enumerator_t *this, va_list args)
 {
+	vici_type_t *out;
+	chunk_t *value;
+	char **name;
 	uint8_t type;
 	chunk_t data;
 
+	VA_ARGS_VGET(args, out, name, value);
+
 	if (!this->reader->remaining(this->reader) ||
 		!this->reader->read_uint8(this->reader, &type))
 	{
@@ -218,7 +223,8 @@ METHOD(vici_message_t, create_enumerator, enumerator_t*,
 
 	INIT(enumerator,
 		.public = {
-			.enumerate = (void*)_parse_enumerate,
+			.enumerate = enumerator_enumerate_default,
+			.venumerate = _parse_enumerate,
 			.destroy = _parse_destroy,
 		},
 		.reader = bio_reader_create(this->encoding),