Re: kern/51753: tcp SACK causes SSH disconnects

[Nick Hudson <skrll%netbsd.org@localhost>]

The following reply was made to PR kern/51753; it has been noted by GNATS.

From: Nick Hudson <skrll%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost, kern-bug-people%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/51753: tcp SACK causes SSH disconnects
Date: Fri, 30 Dec 2016 17:11:18 +0000

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 On 12/30/16 09:50, marcotte%panix.com@localhost wrote:
 >> Number:         51753
 >> Category:       kern
 >> Synopsis:       tcp SACK causes SSH disconnects
 
 Does this help?
 
 Nick
 
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 Index: sys/netinet/tcp_congctl.c
 ===================================================================
 RCS file: /cvsroot/src/sys/netinet/tcp_congctl.c,v
 retrieving revision 1.22
 diff -u -p -r1.22 tcp_congctl.c
 --- sys/netinet/tcp_congctl.c	13 Dec 2016 08:29:03 -0000	1.22
 +++ sys/netinet/tcp_congctl.c	30 Dec 2016 17:10:27 -0000
 @@ -707,7 +707,6 @@ tcp_newreno_fast_retransmit_newack(struc
  		tp->t_partialacks++;
  		TCP_TIMER_DISARM(tp, TCPT_REXMT);
  		tp->t_rtttime = 0;
 -		tp->snd_nxt = th->th_ack;
  
  		if (TCP_SACK_ENABLED(tp)) {
  			/*
 @@ -734,6 +733,7 @@ tcp_newreno_fast_retransmit_newack(struc
  			tp->t_flags |= TF_ACKNOW;
  			(void) tcp_output(tp);
  		} else {
 +			tp->snd_nxt = th->th_ack;
  			/*
  			 * Set snd_cwnd to one segment beyond ACK'd offset
  			 * snd_una is not yet updated when we're called
 
 
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