/* Initialize the congestion window for a connection or
* handles connections that have been idle for
* some time. In this state, no acks are
* expected to clock out any data we send --
* slow start to get ack "clock" running again.
*
* Set the slow-start flight size depending on whether
* this is a local network or not.
*/
void
tcp_newreno_cwnd_init_or_reset(struct tcpcb *tp) {
tcp_cc_cwnd_init_or_reset(tp);
/* If stretch ack was auto disabled, re-evaluate the situation */
tcp_cc_after_idle_stretchack(tp);
}
/*
* Initialize the congestion window at the beginning of a connection or
* after idle time
*/
static void tcp_cubic_cwnd_init_or_reset(struct tcpcb *tp)
{
VERIFY(tp->t_ccstate != NULL);
tcp_cubic_clear_state(tp);
tcp_cc_cwnd_init_or_reset(tp);
/*
* slow start threshold could get initialized to a lower value
* when there is a cached value in the route metrics. In this case,
* the connection can enter congestion avoidance without any packet
* loss and Cubic will enter steady-state too early. It is better
* to always probe to find the initial slow-start threshold.
*/
if (tp->t_inpcb->inp_stat->txbytes <= TCP_CC_CWND_INIT_BYTES
&& tp->snd_ssthresh < (TCP_MAXWIN << TCP_MAX_WINSHIFT))
tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
/* Initialize cubic last max to be same as ssthresh */
tp->t_ccstate->cub_last_max = tp->snd_ssthresh;
/* If stretch ack was auto-disabled, re-evaluate it */
tcp_cc_after_idle_stretchack(tp);
}
