+ limit = field_size - *offset;
+ va_start(args, format);
+ count = vsnprintf(&data_field[*offset], limit, format, args);
+ va_end(args);
+
+ if (count < limit && count > -1) {
+ ptr = NULL + *offset;
+ *offset = *offset + count + 1;
+ }
+
+ return ptr;
+}
+
+char * ustcomm_restore_ptr(char *ptr, char *data_field, int data_field_size)
+{
+ if ((unsigned long)ptr > data_field_size ||
+ ptr == USTCOMM_POISON_PTR) {
+ return NULL;
+ }
+
+ return data_field + (long)ptr;
+}