Add: gvm_json_obj_check_int

There are only two cases that use this variant but there will be
a similar function for strings which will have more cases.

openvasd/openvasd.c

@@ -1257,12 +1257,12 @@ openvasd_get_scan_status (openvasd_connector_t conn)
 static int
 get_member_value_or_fail (cJSON *reader, const gchar *member)
 {
-  cJSON *item = NULL;
-  if ((item = cJSON_GetObjectItem (reader, member)) == NULL
-      && cJSON_IsNumber (item))
+  int ret;
+
+  if (gvm_json_obj_check_int (reader, member, &ret))
     return -1;
 
-  return item->valueint;
+  return ret;
 }
 
 static int

openvasd/vtparser.c

@@ -246,13 +246,11 @@ add_preferences_to_nvt (nvti_t *nvt, cJSON *vt_obj)
               }
             class = prefs_item->valuestring;
 
-            if ((prefs_item = cJSON_GetObjectItem (prefs_obj, "id")) == NULL
-                || !cJSON_IsNumber (prefs_item))
+            if (gvm_json_obj_check_int (prefs_obj, "id", &id))
               {
                 g_warning ("%s: PREF missing id attribute", __func__);
                 continue;
               }
-            id = prefs_item->valueint;
 
             if ((prefs_item = cJSON_GetObjectItem (prefs_obj, "name")) == NULL
                 || !cJSON_IsString (prefs_item))

util/json.c

@@ -83,6 +83,29 @@ gvm_json_obj_double (cJSON *obj, const gchar *key)
   return 0;
 }
 
+/**
+ * @brief Get an int field from a JSON object.
+ *
+ * @param[in]  obj  Object
+ * @param[in]  key  Field name.
+ * @param[out] val  Return location for int if int exists.
+ *
+ * @return 0 if such an int field exists, else 1.
+ */
+int
+gvm_json_obj_check_int (cJSON *obj, const gchar *key, int *val)
+{
+  cJSON *item;
+
+  item = cJSON_GetObjectItem (obj, key);
+  if (item && cJSON_IsNumber (item)) {
+    if (val)
+      *val = item->valueint;
+    return 0;
+  }
+  return 1;
+}
+
 /**
  * @brief Get an int field from a JSON object.
  *

util/json.h

@@ -17,6 +17,9 @@ gvm_json_string_escape (const char *, gboolean);
 double
 gvm_json_obj_double (cJSON *, const gchar *);
 
+int
+gvm_json_obj_check_int (cJSON *, const gchar *, int *);
+
 int
 gvm_json_obj_int (cJSON *, const gchar *);