1 // SPDX-License-Identifier: GPL-2.0
14 	if (!tp->reord_seen) {  in tcp_rack_reo_wnd()
18 		if (inet_csk(sk)->icsk_ca_state >= TCP_CA_Recovery)  in tcp_rack_reo_wnd()
21 		if (tp->sacked_out >= tp->reordering &&  in tcp_rack_reo_wnd()
22 		    !(sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_NO_DUPTHRESH))  in tcp_rack_reo_wnd()
26 	/* To be more reordering resilient, allow min_rtt/4 settling delay.  in tcp_rack_reo_wnd()
32 	return min((tcp_min_rtt(tp) >> 2) * tp->rack.reo_wnd_steps,  in tcp_rack_reo_wnd()
33 		   tp->srtt_us >> 3);  in tcp_rack_reo_wnd()
38 	return tp->rack.rtt_us + reo_wnd -  in tcp_rack_skb_timeout()
39 	       tcp_stamp_us_delta(tp->tcp_mstamp, tcp_skb_timestamp_us(skb));  in tcp_rack_skb_timeout()
42 /* RACK loss detection (IETF draft draft-ietf-tcpm-rack-01):
50  * RACK: sent time delta to the latest delivered packet (time domain)
55  * "settling delay", instead of tweaking the dupthresh.
60  * make us enter the CA_Recovery state.
70 	list_for_each_entry_safe(skb, n, &tp->tsorted_sent_queue,  in tcp_rack_detect_loss()
76 		if ((scb->sacked & TCPCB_LOST) &&  in tcp_rack_detect_loss()
77 		    !(scb->sacked & TCPCB_SACKED_RETRANS))  in tcp_rack_detect_loss()
80 		if (!tcp_rack_sent_after(tp->rack.mstamp,  in tcp_rack_detect_loss()
82 					 tp->rack.end_seq, scb->end_seq))  in tcp_rack_detect_loss()
91 			list_del_init(&skb->tcp_tsorted_anchor);  in tcp_rack_detect_loss()
93 			/* Record maximum wait time */  in tcp_rack_detect_loss()
104 	if (!tp->rack.advanced)  in tcp_rack_mark_lost()
108 	tp->rack.advanced = 0;  in tcp_rack_mark_lost()
113 					  timeout, inet_csk(sk)->icsk_rto);  in tcp_rack_mark_lost()
118 /* Record the most recently (re)sent time among the (s)acked packets
120  * draft-cheng-tcpm-rack-00.txt
127 	rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, xmit_time);  in tcp_rack_advance()
141 	tp->rack.advanced = 1;  in tcp_rack_advance()
142 	tp->rack.rtt_us = rtt_us;  in tcp_rack_advance()
143 	if (tcp_rack_sent_after(xmit_time, tp->rack.mstamp,  in tcp_rack_advance()
144 				end_seq, tp->rack.end_seq)) {  in tcp_rack_advance()
145 		tp->rack.mstamp = xmit_time;  in tcp_rack_advance()
146 		tp->rack.end_seq = end_seq;  in tcp_rack_advance()
157 	u32 lost = tp->lost;  in tcp_rack_reo_timeout()
162 		if (inet_csk(sk)->icsk_ca_state != TCP_CA_Recovery) {  in tcp_rack_reo_timeout()
164 			if (!inet_csk(sk)->icsk_ca_ops->cong_control)  in tcp_rack_reo_timeout()
165 				tcp_cwnd_reduction(sk, 1, tp->lost - lost, 0);  in tcp_rack_reo_timeout()
169 	if (inet_csk(sk)->icsk_pending != ICSK_TIME_RETRANS)  in tcp_rack_reo_timeout()
181  * no. of successful recoveries (accounts for full DSACK-based loss
186  * after the reo_wnd has been updated last time.
195 	if (sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_STATIC_REO_WND ||  in tcp_rack_update_reo_wnd()
196 	    !rs->prior_delivered)  in tcp_rack_update_reo_wnd()
200 	if (before(rs->prior_delivered, tp->rack.last_delivered))  in tcp_rack_update_reo_wnd()
201 		tp->rack.dsack_seen = 0;  in tcp_rack_update_reo_wnd()
204 	if (tp->rack.dsack_seen) {  in tcp_rack_update_reo_wnd()
205 		tp->rack.reo_wnd_steps = min_t(u32, 0xFF,  in tcp_rack_update_reo_wnd()
206 					       tp->rack.reo_wnd_steps + 1);  in tcp_rack_update_reo_wnd()
207 		tp->rack.dsack_seen = 0;  in tcp_rack_update_reo_wnd()
208 		tp->rack.last_delivered = tp->delivered;  in tcp_rack_update_reo_wnd()
209 		tp->rack.reo_wnd_persist = TCP_RACK_RECOVERY_THRESH;  in tcp_rack_update_reo_wnd()
210 	} else if (!tp->rack.reo_wnd_persist) {  in tcp_rack_update_reo_wnd()
211 		tp->rack.reo_wnd_steps = 1;  in tcp_rack_update_reo_wnd()
215 /* RFC6582 NewReno recovery for non-SACK connection. It simply retransmits
222 	const u8 state = inet_csk(sk)->icsk_ca_state;  in tcp_newreno_mark_lost()
225 	if ((state < TCP_CA_Recovery && tp->sacked_out >= tp->reordering) ||  in tcp_newreno_mark_lost()
230 		if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST)  in tcp_newreno_mark_lost()
234 		if (tcp_skb_pcount(skb) > 1 && skb->len > mss)  in tcp_newreno_mark_lost()