From 0bb938e14397628d874fbb36f6df495bdb15997c Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 8 Mar 2001 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2001-03-08

---
 ip/tcp.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/ip/tcp.c b/ip/tcp.c
index 735a5f7f8a368670e91b65e539cd037acc3194d4..b05a27198755b6333a7910a9d72ffb4a467de75a 100644
--- a/ip/tcp.c
+++ b/ip/tcp.c
@@ -1129,8 +1129,16 @@ update(Conv *s, Tcp *seg)
 	}
 
 
-	if(!seq_gt(seg->ack, tcb->snd.una))
+	if(!seq_gt(seg->ack, tcb->snd.una)){
+		/*
+		 *  don't let us hangup if sending into a closed window and
+		 *  we're still getting acks
+		 */
+		if((tcb->flags&RETRAN) && tcb->snd.wnd == 0){
+			tcb->backedoff = MAXBACKMS/4;
+		}
 		return;
+	}
 
         /*
 	 *  any positive ack turns off fast rxt,