bsd/netinet/tcp_ledbat.c

58 int tcp_ledbat_init(struct tcpcb *tp);
59 int tcp_ledbat_cleanup(struct tcpcb *tp);
60 void tcp_ledbat_cwnd_init(struct tcpcb *tp);
61 void tcp_ledbat_inseq_ack_rcvd(struct tcpcb *tp, struct tcphdr *th);
62 void tcp_ledbat_ack_rcvd(struct tcpcb *tp, struct tcphdr *th);
63 void tcp_ledbat_pre_fr(struct tcpcb *tp);
64 void tcp_ledbat_post_fr(struct tcpcb *tp, struct tcphdr *th);
65 void tcp_ledbat_after_idle(struct tcpcb *tp);
66 void tcp_ledbat_after_timeout(struct tcpcb *tp);
67 int tcp_ledbat_delay_ack(struct tcpcb *tp, struct tcphdr *th);
68 void tcp_ledbat_switch_cc(struct tcpcb *tp, uint16_t old_cc_index);
87 extern uint32_t get_base_rtt(struct tcpcb *tp);
139 static void update_cwnd(struct tcpcb *tp, uint32_t incr) {
144 	base_rtt = get_base_rtt(tp);
149 	if (base_rtt == 0 || tp->t_rttcur == 0) {
150 		tp->snd_cwnd += incr;
154 	qdelay = tp->t_rttcur - base_rtt;
166 		if (tp->bg_ssthresh < tp->snd_cwnd)
167 			tp->bg_ssthresh = tp->snd_cwnd;
168 		tp->snd_cwnd += incr;
177 		redwin = tp->snd_cwnd >> 3;
178 		tp->snd_cwnd -= redwin;
179 		if (tp->snd_cwnd < bg_ss_fltsz * tp->t_maxseg)
180 			tp->snd_cwnd = bg_ss_fltsz * tp->t_maxseg;
185 		if (tp->bg_ssthresh > tp->snd_cwnd)
186 			tp->bg_ssthresh = tp->snd_cwnd;
192 	flight_size = tp->snd_max - tp->snd_una;
194 	max_allowed_cwnd = (allowed_increase * tp->t_maxseg)
196 	tp->snd_cwnd = min(tp->snd_cwnd, max_allowed_cwnd);
200 int tcp_ledbat_init(struct tcpcb *tp) {
201 #pragma unused(tp)
206 int tcp_ledbat_cleanup(struct tcpcb *tp) {
207 #pragma unused(tp)
217 tcp_ledbat_cwnd_init(struct tcpcb *tp) {
218 	tp->snd_cwnd = tp->t_maxseg * bg_ss_fltsz;
219 	tp->bg_ssthresh = tp->snd_ssthresh;
227 tcp_ledbat_inseq_ack_rcvd(struct tcpcb *tp, struct tcphdr *th) {
231 	acked = th->th_ack - tp->snd_una;
232 	tp->t_bytes_acked += acked;
233 	if (tp->t_bytes_acked > tp->snd_cwnd) {
234 		tp->t_bytes_acked -= tp->snd_cwnd;
235 		incr = tp->t_maxseg;
238 	if (tp->snd_cwnd < tp->snd_wnd && incr > 0) {
239 		update_cwnd(tp, incr);
245 tcp_ledbat_ack_rcvd(struct tcpcb *tp, struct tcphdr *th) {
259 	register u_int cw = tp->snd_cwnd;
260 	register u_int incr = tp->t_maxseg;
263 	acked = th->th_ack - tp->snd_una;
264 	tp->t_bytes_acked += acked;
265 	if (cw >= tp->bg_ssthresh) {
267 		if (tp->t_bytes_acked < cw) {
282 			tp->snd_nxt == tp->snd_max) ? incr * 2 : incr;
286 	if (tp->t_bytes_acked >= cw)
287 		tp->t_bytes_acked -= cw;
289 		update_cwnd(tp, incr);
293 tcp_ledbat_pre_fr(struct tcpcb *tp) {
296 	win = min(tp->snd_wnd, tp->snd_cwnd) /
297 		2 / tp->t_maxseg;
300 	tp->snd_ssthresh = win * tp->t_maxseg;
301 	if (tp->bg_ssthresh > tp->snd_ssthresh)
302 		tp->bg_ssthresh = tp->snd_ssthresh;
304 	tcp_cc_resize_sndbuf(tp);
308 tcp_ledbat_post_fr(struct tcpcb *tp, struct tcphdr *th) {
311 	ss = tp->snd_max - th->th_ack;
322 	if (ss < (int32_t)tp->snd_ssthresh)
323 		tp->snd_cwnd = ss + tp->t_maxseg;
325 		tp->snd_cwnd = tp->snd_ssthresh;
326 	tp->t_bytes_acked = 0;
335 tcp_ledbat_after_idle(struct tcpcb *tp) {
342 	if (tp->t_rttcur > 0) {
345 		idle_time = tcp_now - tp->t_rcvtime;
346 		nrtt = idle_time / tp->t_rttcur;
352 		tp->rtt_hist[i] = 0;
355 		tp->rtt_hist[n] = tp->rtt_hist[i];
356 		tp->rtt_hist[i] = 0;
360 	tp->snd_cwnd = tp->t_maxseg * bg_ss_fltsz;
371 tcp_ledbat_after_timeout(struct tcpcb *tp) {
372 	if (tp->t_state >=  TCPS_ESTABLISHED) {
373 		u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg;
376 		tp->snd_cwnd = tp->t_maxseg;
377 		tp->snd_ssthresh = win * tp->t_maxseg;
378 		tp->t_bytes_acked = 0;
379 		tp->t_dupacks = 0;
381 		if (tp->bg_ssthresh > tp->snd_ssthresh)
382 			tp->bg_ssthresh = tp->snd_ssthresh;
384 		tcp_cc_resize_sndbuf(tp);
403 tcp_ledbat_delay_ack(struct tcpcb *tp, struct tcphdr *th) {
404 	if ((tp->t_flags & TF_RXWIN0SENT) == 0 &&
406 		(tp->t_unacksegs == 1))
415 tcp_ledbat_switch_cc(struct tcpcb *tp, uint16_t old_cc_index) {
419 	if (tp->bg_ssthresh == 0 || tp->bg_ssthresh > tp->snd_ssthresh)
420 		tp->bg_ssthresh = tp->snd_ssthresh;
422 	cwnd = min(tp->snd_wnd, tp->snd_cwnd);
424 	if (tp->snd_cwnd > tp->bg_ssthresh)
425 		cwnd = cwnd / tp->t_maxseg;
427 		cwnd = cwnd / 2 / tp->t_maxseg;
432 	tp->snd_cwnd = cwnd * tp->t_maxseg;
433 	tp->t_bytes_acked = 0;