1 files changed, 8 insertions, 26 deletions

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 016003057192..b1c968e83f97 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -435,15 +435,9 @@ cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type)
 		tp->t_dupacks = 0;
 		tp->t_bytes_acked = 0;
 		EXIT_RECOVERY(tp->t_flags);
-		if (CC_ALGO(tp)->cong_signal == NULL) {
-			/*
-			 * RFC5681 Section 3.1 
-			 * ssthresh = max (FlightSize / 2, 2*SMSS) eq (4)
-			 */
-			tp->snd_ssthresh =
-			    max((tp->snd_max - tp->snd_una) / 2, 2 * maxseg);
-			tp->snd_cwnd = maxseg;
-		}
+		tp->snd_ssthresh = max(2, min(tp->snd_wnd, tp->snd_cwnd) / 2 /
+		    maxseg) * maxseg;
+		tp->snd_cwnd = maxseg;
 		break;
 	case CC_RTO_ERR:
 		TCPSTAT_INC(tcps_sndrexmitbad);
@@ -2612,15 +2606,6 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 
 						if (awnd < tp->snd_ssthresh) {
 							tp->snd_cwnd += maxseg;
-							/*
-							 * RFC5681 Section 3.2 talks about cwnd
-							 * inflation on additional dupacks and
-							 * deflation on recovering from loss.
-							 *
-							 * We keep cwnd into check so that
-							 * we don't have to 'deflate' it when we
-							 * get out of recovery.
-							 */
 							if (tp->snd_cwnd > tp->snd_ssthresh)
 								tp->snd_cwnd = tp->snd_ssthresh;
 						}
@@ -2660,22 +2645,19 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 						TCPSTAT_INC(
 						    tcps_sack_recovery_episode);
 						tp->sack_newdata = tp->snd_nxt;
-						if (CC_ALGO(tp)->cong_signal == NULL)
-							tp->snd_cwnd = maxseg;
+						tp->snd_cwnd = maxseg;
 						(void) tp->t_fb->tfb_tcp_output(tp);
 						goto drop;
 					}
 					tp->snd_nxt = th->th_ack;
-					if (CC_ALGO(tp)->cong_signal == NULL)
-						tp->snd_cwnd = maxseg;
+					tp->snd_cwnd = maxseg;
 					(void) tp->t_fb->tfb_tcp_output(tp);
 					KASSERT(tp->snd_limited <= 2,
 					    ("%s: tp->snd_limited too big",
 					    __func__));
-					if (CC_ALGO(tp)->cong_signal == NULL)
-						tp->snd_cwnd = tp->snd_ssthresh +
-						    maxseg *
-						    (tp->t_dupacks - tp->snd_limited);
+					tp->snd_cwnd = tp->snd_ssthresh +
+					     maxseg *
+					     (tp->t_dupacks - tp->snd_limited);
 					if (SEQ_GT(onxt, tp->snd_nxt))
 						tp->snd_nxt = onxt;
 					goto drop;