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, 16 insertions, 19 deletions

diff --git a/src/libcharon/plugins/kernel_libipsec/kernel_libipsec_ipsec.c b/src/libcharon/plugins/kernel_libipsec/kernel_libipsec_ipsec.c
index 77e37e249..d4832e233 100644
--- a/src/libcharon/plugins/kernel_libipsec/kernel_libipsec_ipsec.c
+++ b/src/libcharon/plugins/kernel_libipsec/kernel_libipsec_ipsec.c
@@ -84,12 +84,12 @@ static void exclude_route_destroy(exclude_route_t *this)
 	free(this);
 }
 
-/**
- * Find an exclude route entry by destination address
- */
-static bool exclude_route_match(exclude_route_t *current,
-								host_t *dst)
+CALLBACK(exclude_route_match, bool,
+	exclude_route_t *current, va_list args)
 {
+	host_t *dst;
+
+	VA_ARGS_VGET(args, dst);
 	return dst->ip_equals(dst, current->dst);
 }
 
@@ -204,12 +204,12 @@ static void policy_entry_destroy(policy_entry_t *this)
 	free(this);
 }
 
-/**
- * Compare two policy_entry_t objects
- */
-static inline bool policy_entry_equals(policy_entry_t *a,
-									   policy_entry_t *b)
+CALLBACK(policy_entry_equals, bool,
+	policy_entry_t *a, va_list args)
 {
+	policy_entry_t *b;
+
+	VA_ARGS_VGET(args, b);
 	return a->direction == b->direction &&
 		   a->src.proto == b->src.proto &&
 		   a->dst.proto == b->dst.proto &&
@@ -297,9 +297,8 @@ static void add_exclude_route(private_kernel_libipsec_ipsec_t *this,
 	exclude_route_t *exclude;
 	host_t *gtw;
 
-	if (this->excludes->find_first(this->excludes,
-								  (linked_list_match_t)exclude_route_match,
-								  (void**)&exclude, dst) == SUCCESS)
+	if (this->excludes->find_first(this->excludes, exclude_route_match,
+								  (void**)&exclude, dst))
 	{
 		route->exclude = exclude;
 		exclude->refs++;
@@ -524,9 +523,8 @@ METHOD(kernel_ipsec_t, add_policy, status_t,
 	policy = create_policy_entry(id->src_ts, id->dst_ts, id->dir);
 
 	this->mutex->lock(this->mutex);
-	if (this->policies->find_first(this->policies,
-								  (linked_list_match_t)policy_entry_equals,
-								  (void**)&found, policy) == SUCCESS)
+	if (this->policies->find_first(this->policies, policy_entry_equals,
+								  (void**)&found, policy))
 	{
 		policy_entry_destroy(policy);
 		policy = found;
@@ -567,9 +565,8 @@ METHOD(kernel_ipsec_t, del_policy, status_t,
 	policy = create_policy_entry(id->src_ts, id->dst_ts, id->dir);
 
 	this->mutex->lock(this->mutex);
-	if (this->policies->find_first(this->policies,
-								  (linked_list_match_t)policy_entry_equals,
-								  (void**)&found, policy) != SUCCESS)
+	if (!this->policies->find_first(this->policies, policy_entry_equals,
+									(void**)&found, policy))
 	{
 		policy_entry_destroy(policy);
 		this->mutex->unlock(this->mutex);