L2TPD_ASSERT
L2TPD_ASSERT(plsnr != NULL);
L2TPD_ASSERT(plsnr->sock == -1);
L2TPD_ASSERT(slist_length(&_this->listener) == idx);
L2TPD_ASSERT(sizeof(plistener->bind) >= addr->sa_len);
L2TPD_ASSERT(_this != NULL);
L2TPD_ASSERT(plsnr != NULL);
L2TPD_ASSERT(plsnr->sock == -1);
L2TPD_ASSERT(shuffle_cnt == 0);
L2TPD_ASSERT(_this->state == L2TPD_STATE_INIT);
L2TPD_ASSERT(_this != NULL);