TCP_SYNACK_RETRANS
if (!req->num_timeout || synack_type != TCP_SYNACK_RETRANS) {
synack_type != TCP_SYNACK_RETRANS && remaining >= TCPOLEN_ACCECN_BASE) {
case TCP_SYNACK_RETRANS:
res = af_ops->send_synack(sk, NULL, &fl, req, NULL, TCP_SYNACK_RETRANS,