From owner-freebsd-hackers@FreeBSD.ORG Sat Jan 20 09:18:49 2007 Return-Path: X-Original-To: hackers@freebsd.org Delivered-To: freebsd-hackers@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B696E16A402 for ; Sat, 20 Jan 2007 09:18:49 +0000 (UTC) (envelope-from steve@Watt.COM) Received: from wattres.watt.com (wattres.watt.com [66.93.133.130]) by mx1.freebsd.org (Postfix) with ESMTP id 7E9D013C468 for ; Sat, 20 Jan 2007 09:18:49 +0000 (UTC) (envelope-from steve@Watt.COM) Received: from wattres.watt.com (localhost.watt.com [127.0.0.1]) by wattres.watt.com (8.13.8/8.13.8) with ESMTP id l0K9Ig21002428; Sat, 20 Jan 2007 01:18:47 -0800 (PST) (envelope-from steve@wattres.watt.com) Received: (from steve@localhost) by wattres.watt.com (8.13.8/8.13.8/Submit) id l0K9Igbn002427; Sat, 20 Jan 2007 01:18:42 -0800 (PST) (envelope-from steve) Message-Id: <200701200918.l0K9Igbn002427@wattres.watt.com> X-Newsgroups: local.freebsd-hackers In-Reply-To: <459AD141.5010502@elischer.org> From: steve@Watt.COM (Steve Watt) References: <200701020825.l028PMBK034571@wattres.watt.com> Organization: Watt Consultants, San Jose, CA, USA Date: Sat, 20 Jan 2007 01:18:42 -0800 X-Mailer: Mail User's Shell (7.2.6 beta(5) 10/07/98) To: julian@elischer.org X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (wattres.watt.com [127.0.0.1]); Sat, 20 Jan 2007 01:18:47 -0800 (PST) X-Archived: 1169284727.187879739@wattres.Watt.COM Cc: hackers@freebsd.org, andre@freebsd.org Subject: Re: Interesting TCP issue X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Jan 2007 09:18:49 -0000 In <459AD141.5010502@elischer.org>, Julian Elischer wrote: [ Snip discussion of symptoms of window scaling broken when talking to at least the skype mail servers. ] >we have seen this since 4.x >I think a fix may be in 7.0 but I'm not sure.. >I thin kthere is a problem when the far end sets the window down to 1 >but scales it by a factor of 2^{big number}. > >Andre, can you check out this problem and MFC the correct fix >if it is indeed the same problem in 6.2? It is the same problem; I took the (one-line) fix as indicated by >http://cvs.ironport.com/cgi-bin/viewcvs.cgi/freebsd/src/sys/netinet/tcp_syncache.c.diff?r1=1.84&r2=1.85 (well, not cvs.ironport.com, which doesn't seem to exist at the moment), and applied the diff from 1.84 to 1.85 and to a 6.2-PRERELEASE box updated around 25 Dec 06. It works like a charm. I would vote to MFC 1.85 now that 6.2 is out. The diff, for those who are following along at home, is: =================================================================== RCS file: /usr/local/www/cvsroot/FreeBSD/src/sys/netinet/tcp_syncache.c,v retrieving revision 1.84 retrieving revision 1.85 diff -u -p -r1.84 -r1.85 --- src/sys/netinet/tcp_syncache.c 2006/02/09 21:29:02 1.84 +++ src/sys/netinet/tcp_syncache.c 2006/02/28 23:05:59 1.85 @@ -682,7 +682,7 @@ syncache_socket(sc, lso, m) tp->t_flags |= TF_NOOPT; if (sc->sc_flags & SCF_WINSCALE) { tp->t_flags |= TF_REQ_SCALE|TF_RCVD_SCALE; - tp->requested_s_scale = sc->sc_requested_s_scale; + tp->snd_scale = sc->sc_requested_s_scale; tp->request_r_scale = sc->sc_request_r_scale; } if (sc->sc_flags & SCF_TIMESTAMP) { -- Steve Watt KD6GGD PP-ASEL-IA ICBM: 121W 56' 57.5" / 37N 20' 15.3" Internet: steve @ Watt.COM Whois: SW32-ARIN Free time? There's no such thing. It just comes in varying prices...