log.Debug("listener closed - returning")
				return
			}

			log.Errorf("failed to accept conn: %v", err)
			continue
		}
		log.Debug("connection accepted")
		go func() {
			log.Debug("handling conn")
			if err := z.handleConn(ctx, conn); err != nil {
				log.Errorf("failed to handle conn: %v", err)
			}
		}()
	}
}

// ZDS protocol is very simple, for every message sent, and ack is sent.