Function bbr_init

freebsd/netinet/tcp_stacks/bbr.c:10058–10266

* Return 0 on success, non-zero on failure * which indicates the error (usually no memory). */

 * which indicates the error (usually no memory).
 */
static int
bbr_init(struct tcpcb *tp)
{
	struct tcp_bbr *bbr = NULL;
	struct inpcb *inp;
	uint32_t cts;

	tp->t_fb_ptr = uma_zalloc(bbr_pcb_zone, (M_NOWAIT | M_ZERO));
	if (tp->t_fb_ptr == NULL) {
		/*
		 * We need to allocate memory but cant. The INP and INP_INFO
		 * locks and they are recusive (happens during setup. So a
		 * scheme to drop the locks fails :(
		 *
		 */
		return (ENOMEM);
	}
	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
	bbr->rtt_valid = 0;
	inp = tp->t_inpcb;
	inp->inp_flags2 |= INP_CANNOT_DO_ECN;
	inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
	TAILQ_INIT(&bbr->r_ctl.rc_map);
	TAILQ_INIT(&bbr->r_ctl.rc_free);
	TAILQ_INIT(&bbr->r_ctl.rc_tmap);
	bbr->rc_tp = tp;
	if (tp->t_inpcb) {
		bbr->rc_inp = tp->t_inpcb;
	}
	cts = tcp_get_usecs(&bbr->rc_tv);
	tp->t_acktime = 0;
	bbr->rc_allow_data_af_clo = bbr_ignore_data_after_close;
	bbr->r_ctl.rc_reorder_fade = bbr_reorder_fade;
	bbr->rc_tlp_threshold = bbr_tlp_thresh;
	bbr->r_ctl.rc_reorder_shift = bbr_reorder_thresh;
	bbr->r_ctl.rc_pkt_delay = bbr_pkt_delay;
	bbr->r_ctl.rc_min_to = bbr_min_to;
	bbr->rc_bbr_state = BBR_STATE_STARTUP;
	bbr->r_ctl.bbr_lost_at_state = 0;
	bbr->r_ctl.rc_lost_at_startup = 0;
	bbr->rc_all_timers_stopped = 0;
	bbr->r_ctl.rc_bbr_lastbtlbw = 0;
	bbr->r_ctl.rc_pkt_epoch_del = 0;
	bbr->r_ctl.rc_pkt_epoch = 0;
	bbr->r_ctl.rc_lowest_rtt = 0xffffffff;
	bbr->r_ctl.rc_bbr_hptsi_gain = bbr_high_gain;
	bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
	bbr->r_ctl.rc_went_idle_time = cts;
	bbr->rc_pacer_started = cts;
	bbr->r_ctl.rc_pkt_epoch_time = cts;
	bbr->r_ctl.rc_rcvtime = cts;
	bbr->r_ctl.rc_bbr_state_time = cts;
	bbr->r_ctl.rc_del_time = cts;
	bbr->r_ctl.rc_tlp_rxt_last_time = cts;
	bbr->r_ctl.last_in_probertt = cts;
	bbr->skip_gain = 0;
	bbr->gain_is_limited = 0;
	bbr->no_pacing_until = bbr_no_pacing_until;