tcp_drain_input
if (tcp_drain_input(listener, sock_id, 5) < 0) {
static int tcp_drain_input(tcp_t *, int, int);
if (tcp_drain_input(tcp, sock_id, 5) < 0)
if (tcp_drain_input(tcp, sock_id, 5) < 0) {
if (tcp_drain_input(tcp, sock_id, 5) < 0) {
if (tcp_drain_input(tcp, sock_id, 5) < 0) {