1 // SPDX-License-Identifier: GPL-2.0
9 	if (!tp->reord_seen) {  in tcp_rack_reo_wnd()
13 		if (inet_csk(sk)->icsk_ca_state >= TCP_CA_Recovery)  in tcp_rack_reo_wnd()
16 		if (tp->sacked_out >= tp->reordering &&  in tcp_rack_reo_wnd()
17 		    !(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) &  in tcp_rack_reo_wnd()
22 	/* To be more reordering resilient, allow min_rtt/4 settling delay.  in tcp_rack_reo_wnd()
28 	return min((tcp_min_rtt(tp) >> 2) * tp->rack.reo_wnd_steps,  in tcp_rack_reo_wnd()
29 		   tp->srtt_us >> 3);  in tcp_rack_reo_wnd()
34 	return tp->rack.rtt_us + reo_wnd -  in tcp_rack_skb_timeout()
35 	       tcp_stamp_us_delta(tp->tcp_mstamp, tcp_skb_timestamp_us(skb));  in tcp_rack_skb_timeout()
38 /* RACK loss detection (IETF draft draft-ietf-tcpm-rack-01):
46  * RACK: sent time delta to the latest delivered packet (time domain)
51  * "settling delay", instead of tweaking the dupthresh.
56  * make us enter the CA_Recovery state.
66 	list_for_each_entry_safe(skb, n, &tp->tsorted_sent_queue,  in tcp_rack_detect_loss()
72 		if ((scb->sacked & TCPCB_LOST) &&  in tcp_rack_detect_loss()
73 		    !(scb->sacked & TCPCB_SACKED_RETRANS))  in tcp_rack_detect_loss()
76 		if (!tcp_skb_sent_after(tp->rack.mstamp,  in tcp_rack_detect_loss()
78 					tp->rack.end_seq, scb->end_seq))  in tcp_rack_detect_loss()
87 			list_del_init(&skb->tcp_tsorted_anchor);  in tcp_rack_detect_loss()
89 			/* Record maximum wait time */  in tcp_rack_detect_loss()
100 	if (!tp->rack.advanced)  in tcp_rack_mark_lost()
104 	tp->rack.advanced = 0;  in tcp_rack_mark_lost()
109 					  timeout, inet_csk(sk)->icsk_rto);  in tcp_rack_mark_lost()
114 /* Record the most recently (re)sent time among the (s)acked packets
116  * draft-cheng-tcpm-rack-00.txt
123 	rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, xmit_time);  in tcp_rack_advance()
137 	tp->rack.advanced = 1;  in tcp_rack_advance()
138 	tp->rack.rtt_us = rtt_us;  in tcp_rack_advance()
139 	if (tcp_skb_sent_after(xmit_time, tp->rack.mstamp,  in tcp_rack_advance()
140 			       end_seq, tp->rack.end_seq)) {  in tcp_rack_advance()
141 		tp->rack.mstamp = xmit_time;  in tcp_rack_advance()
142 		tp->rack.end_seq = end_seq;  in tcp_rack_advance()
153 	u32 lost = tp->lost;  in tcp_rack_reo_timeout()
158 		if (inet_csk(sk)->icsk_ca_state != TCP_CA_Recovery) {  in tcp_rack_reo_timeout()
160 			if (!inet_csk(sk)->icsk_ca_ops->cong_control)  in tcp_rack_reo_timeout()
161 				tcp_cwnd_reduction(sk, 1, tp->lost - lost, 0);  in tcp_rack_reo_timeout()
165 	if (inet_csk(sk)->icsk_pending != ICSK_TIME_RETRANS)  in tcp_rack_reo_timeout()
177  * no. of successful recoveries (accounts for full DSACK-based loss
182  * after the reo_wnd has been updated last time.
191 	if ((READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) &  in tcp_rack_update_reo_wnd()
193 	    !rs->prior_delivered)  in tcp_rack_update_reo_wnd()
197 	if (before(rs->prior_delivered, tp->rack.last_delivered))  in tcp_rack_update_reo_wnd()
198 		tp->rack.dsack_seen = 0;  in tcp_rack_update_reo_wnd()
201 	if (tp->rack.dsack_seen) {  in tcp_rack_update_reo_wnd()
202 		tp->rack.reo_wnd_steps = min_t(u32, 0xFF,  in tcp_rack_update_reo_wnd()
203 					       tp->rack.reo_wnd_steps + 1);  in tcp_rack_update_reo_wnd()
204 		tp->rack.dsack_seen = 0;  in tcp_rack_update_reo_wnd()
205 		tp->rack.last_delivered = tp->delivered;  in tcp_rack_update_reo_wnd()
206 		tp->rack.reo_wnd_persist = TCP_RACK_RECOVERY_THRESH;  in tcp_rack_update_reo_wnd()
207 	} else if (!tp->rack.reo_wnd_persist) {  in tcp_rack_update_reo_wnd()
208 		tp->rack.reo_wnd_steps = 1;  in tcp_rack_update_reo_wnd()
212 /* RFC6582 NewReno recovery for non-SACK connection. It simply retransmits
219 	const u8 state = inet_csk(sk)->icsk_ca_state;  in tcp_newreno_mark_lost()
222 	if ((state < TCP_CA_Recovery && tp->sacked_out >= tp->reordering) ||  in tcp_newreno_mark_lost()
227 		if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST)  in tcp_newreno_mark_lost()
231 		if (tcp_skb_pcount(skb) > 1 && skb->len > mss)  in tcp_newreno_mark_lost()