Merge pull request #11901 from akallabeth/jansson-fix

[winpr,json] fix a memory leak with jansson

winpr/libwinpr/utils/json/jansson.c

@@ -26,6 +26,65 @@
 #endif
 #include <jansson.h>
 
+#if defined(WITH_DEBUG_JANSSON)
+#include "../log.h"
+#define TAG WINPR_TAG("jansson")
+
+#define ccast(json) ccast_((json), __func__)
+static const json_t* ccast_(const WINPR_JSON* json, const char* fkt)
+{
+	const json_t* jansson = (const json_t*)json;
+	if (!jansson)
+		WLog_DBG(TAG, "%s: NULL", fkt);
+	else
+	{
+		WLog_DBG(TAG, "%s: %" PRIuz, fkt, jansson->refcount);
+	}
+	return jansson;
+}
+
+#define cast(json) cast_((json), __func__)
+static json_t* cast_(WINPR_JSON* json, const char* fkt)
+{
+	json_t* jansson = (json_t*)json;
+	if (!jansson)
+		WLog_DBG(TAG, "%s: NULL", fkt);
+	else
+	{
+		WLog_DBG(TAG, "%s: %" PRIuz, fkt, jansson->refcount);
+	}
+	return jansson;
+}
+
+#define revcast(json) revcast_((json), __func__)
+static WINPR_JSON* revcast_(json_t* json, const char* fkt)
+{
+	json_t* jansson = (json_t*)json;
+	if (!jansson)
+		WLog_DBG(TAG, "%s: NULL", fkt);
+	else
+	{
+		WLog_DBG(TAG, "%s: %" PRIuz, fkt, jansson->refcount);
+	}
+	return jansson;
+}
+#else
+static inline const json_t* ccast(const WINPR_JSON* json)
+{
+	return WINPR_CXX_COMPAT_CAST(const json_t*, json);
+}
+
+static inline json_t* cast(WINPR_JSON* json)
+{
+	return WINPR_CXX_COMPAT_CAST(json_t*, json);
+}
+
+static inline WINPR_JSON* revcast(json_t* json)
+{
+	return WINPR_CXX_COMPAT_CAST(WINPR_JSON*, json);
+}
+#endif
+
 int WINPR_JSON_version(char* buffer, size_t len)
 {
 	return _snprintf(buffer, len, "jansson %s", jansson_version_str());
@@ -34,51 +93,52 @@ int WINPR_JSON_version(char* buffer, size_t len)
 WINPR_JSON* WINPR_JSON_Parse(const char* value)
 {
 	json_error_t error = { 0 };
-	return json_loads(value, JSON_DECODE_ANY, &error);
+	return revcast(json_loads(value, JSON_DECODE_ANY, &error));
 }
 
 WINPR_JSON* WINPR_JSON_ParseWithLength(const char* value, size_t buffer_length)
 {
 	json_error_t error = { 0 };
-	return json_loadb(value, buffer_length, JSON_DECODE_ANY, &error);
+	return revcast(json_loadb(value, buffer_length, JSON_DECODE_ANY, &error));
 }
 
 void WINPR_JSON_Delete(WINPR_JSON* item)
 {
-	json_delete((json_t*)item);
+	json_delete(cast(item));
 }
 
 WINPR_JSON* WINPR_JSON_GetArrayItem(const WINPR_JSON* array, size_t index)
 {
-	return json_array_get(array, index);
+	return revcast(json_array_get(ccast(array), index));
 }
 
 size_t WINPR_JSON_GetArraySize(const WINPR_JSON* array)
 {
-	return json_array_size(array);
+	return json_array_size(ccast(array));
 }
 
 WINPR_JSON* WINPR_JSON_GetObjectItem(const WINPR_JSON* object, const char* string)
 {
-	void* it = json_object_iter((json_t*)object);
+	json_t* json = cast(WINPR_CAST_CONST_PTR_AWAY(object, WINPR_JSON*));
+	void* it = json_object_iter(json);
 	while (it)
 	{
 		const char* name = json_object_iter_key(it);
 		if (_stricmp(name, string) == 0)
-			return json_object_iter_value(it);
-		it = json_object_iter_next((json_t*)object, it);
+			return revcast(json_object_iter_value(it));
+		it = json_object_iter_next(json, it);
 	}
 	return NULL;
 }
 
 WINPR_JSON* WINPR_JSON_GetObjectItemCaseSensitive(const WINPR_JSON* object, const char* string)
 {
-	return json_object_get(object, string);
+	return revcast(json_object_get(ccast(object), string));
 }
 
 BOOL WINPR_JSON_HasObjectItem(const WINPR_JSON* object, const char* string)
 {
-	return json_object_get(object, string) != NULL;
+	return json_object_get(ccast(object), string) != NULL;
 }
 
 const char* WINPR_JSON_GetErrorPtr(void)
@@ -88,16 +148,17 @@ const char* WINPR_JSON_GetErrorPtr(void)
 
 const char* WINPR_JSON_GetStringValue(WINPR_JSON* item)
 {
-	return json_string_value(item);
+	return json_string_value(cast(item));
 }
 
 double WINPR_JSON_GetNumberValue(const WINPR_JSON* item)
 {
-	return json_real_value((const json_t*)item);
+	return json_real_value(ccast(item));
 }
 
-BOOL WINPR_JSON_IsInvalid(const WINPR_JSON* item)
+BOOL WINPR_JSON_IsInvalid(const WINPR_JSON* json)
 {
+	const json_t* item = ccast(json);
 	if (WINPR_JSON_IsArray(item))
 		return FALSE;
 	if (WINPR_JSON_IsObject(item))
@@ -115,91 +176,93 @@ BOOL WINPR_JSON_IsInvalid(const WINPR_JSON* item)
 
 BOOL WINPR_JSON_IsFalse(const WINPR_JSON* item)
 {
-	return json_is_false((const json_t*)item);
+	return json_is_false(ccast(item));
 }
 
 BOOL WINPR_JSON_IsTrue(const WINPR_JSON* item)
 {
-	return json_is_true((const json_t*)item);
+	return json_is_true(ccast(item));
 }
 
 BOOL WINPR_JSON_IsBool(const WINPR_JSON* item)
 {
-	return json_is_boolean((const json_t*)item);
+	return json_is_boolean(ccast(item));
 }
 
 BOOL WINPR_JSON_IsNull(const WINPR_JSON* item)
 {
-	return json_is_null((const json_t*)item);
+	return json_is_null(ccast(item));
 }
 
 BOOL WINPR_JSON_IsNumber(const WINPR_JSON* item)
 {
-	return json_is_number((const json_t*)item);
+	return json_is_number(ccast(item));
 }
 
 BOOL WINPR_JSON_IsString(const WINPR_JSON* item)
 {
-	return json_is_string((const json_t*)item);
+	return json_is_string(ccast(item));
 }
 
 BOOL WINPR_JSON_IsArray(const WINPR_JSON* item)
 {
-	return json_is_array((const json_t*)item);
+	return json_is_array(ccast(item));
 }
 
 BOOL WINPR_JSON_IsObject(const WINPR_JSON* item)
 {
-	return json_is_array((const json_t*)item);
+	return json_is_array(ccast(item));
 }
 
 WINPR_JSON* WINPR_JSON_CreateNull(void)
 {
-	return json_null();
+	return revcast(json_null());
 }
 
 WINPR_JSON* WINPR_JSON_CreateTrue(void)
 {
-	return json_true();
+	return revcast(json_true());
 }
 
 WINPR_JSON* WINPR_JSON_CreateFalse(void)
 {
-	return json_false();
+	return revcast(json_false());
 }
 
 WINPR_JSON* WINPR_JSON_CreateBool(BOOL boolean)
 {
-	return json_boolean(boolean);
+	return revcast(json_boolean(boolean));
 }
 
 WINPR_JSON* WINPR_JSON_CreateNumber(double num)
 {
-	return json_real(num);
+	return revcast(json_real(num));
 }
 
 WINPR_JSON* WINPR_JSON_CreateString(const char* string)
 {
-	return json_string(string);
+	return revcast(json_string(string));
 }
 
 WINPR_JSON* WINPR_JSON_CreateArray(void)
 {
-	return json_array();
+	return revcast(json_array());
 }
 
 WINPR_JSON* WINPR_JSON_CreateObject(void)
 {
-	return json_object();
+	return revcast(json_object());
 }
 
 static WINPR_JSON* add_to_object(WINPR_JSON* object, const char* name, json_t* obj)
 {
 	if (!obj)
 		return NULL;
-	if (json_object_set_new(object, name, obj) != 0)
+	const BOOL rc = (json_object_set_new(cast(object), name, obj) != 0);
+	json_decref(obj);
+	if (!rc)
 		return NULL;
-	return obj;
+	return revcast(obj);
 }
 
 WINPR_JSON* WINPR_JSON_AddNullToObject(WINPR_JSON* object, const char* name)
@@ -246,7 +309,7 @@ WINPR_JSON* WINPR_JSON_AddObjectToObject(WINPR_JSON* object, const char* name)
 
 BOOL WINPR_JSON_AddItemToArray(WINPR_JSON* array, WINPR_JSON* item)
 {
-	return json_array_append(array, item) == 0;
+	return json_array_append(cast(array), item) == 0;
 }
 
 WINPR_JSON* WINPR_JSON_AddArrayToObject(WINPR_JSON* object, const char* name)
@@ -257,10 +320,10 @@ WINPR_JSON* WINPR_JSON_AddArrayToObject(WINPR_JSON* object, const char* name)
 
 char* WINPR_JSON_Print(WINPR_JSON* item)
 {
-	return json_dumps(item, JSON_INDENT(2) | JSON_ENSURE_ASCII | JSON_SORT_KEYS);
+	return json_dumps(cast(item), JSON_INDENT(2) | JSON_ENSURE_ASCII | JSON_SORT_KEYS);
 }
 
 char* WINPR_JSON_PrintUnformatted(WINPR_JSON* item)
 {
-	return json_dumps(item, JSON_COMPACT | JSON_ENSURE_ASCII | JSON_SORT_KEYS);
+	return json_dumps(cast(item), JSON_COMPACT | JSON_ENSURE_ASCII | JSON_SORT_KEYS);
 }