From 429f14f83ae1f6357a9455d4f075522420b01b03 Mon Sep 17 00:00:00 2001
From: Richard Scheffenegger <rscheff@FreeBSD.org>
Date: Mon, 8 Jan 2024 09:28:01 +0100
Subject: [PATCH] tcp: clean PRR state after ECN congestion recovery.

PRR state was not properly reset on subsequent ECN CE
events. Clean up after local transmission failures too.

Reviewed by:           tuexen, cc, #transport
MFC after:             3 days
Sponsored by:          NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D43170
---
 sys/netinet/tcp_input.c  | 1 +
 sys/netinet/tcp_output.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 0014c11d9daa..ed5f28490852 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -483,6 +483,7 @@ cc_post_recovery(struct tcpcb *tp, struct tcphdr *th)
 	/* XXXLAS: EXIT_RECOVERY ? */
 	tp->t_bytes_acked = 0;
 	tp->sackhint.delivered_data = 0;
+	tp->sackhint.prr_delivered = 0;
 	tp->sackhint.prr_out = 0;
 }
 
diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index 8d863ffcf432..1ff6f5bee39a 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -1663,6 +1663,8 @@ tcp_default_output(struct tcpcb *tp)
 				if (flags & TH_FIN)
 					tp->snd_nxt--;
 			}
+			if (IN_RECOVERY(tp->t_flags))
+				tp->sackhint.prr_out -= len;
 		}
 		SOCKBUF_UNLOCK_ASSERT(&so->so_snd);	/* Check gotos. */
 		switch (error) {