From owner-freebsd-net@FreeBSD.ORG Wed Dec 30 10:40:04 2009 Return-Path: Delivered-To: freebsd-net@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9D376106568D for ; Wed, 30 Dec 2009 10:40:04 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 8AC218FC16 for ; Wed, 30 Dec 2009 10:40:04 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.3/8.14.3) with ESMTP id nBUAe4g5074723 for ; Wed, 30 Dec 2009 10:40:04 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.3/8.14.3/Submit) id nBUAe4YN074722; Wed, 30 Dec 2009 10:40:04 GMT (envelope-from gnats) Date: Wed, 30 Dec 2009 10:40:04 GMT Message-Id: <200912301040.nBUAe4YN074722@freefall.freebsd.org> To: freebsd-net@FreeBSD.org From: Dennis Yusupoff Cc: Subject: Re: kern/141843: [em] [vlan] Intel txcsum and assigned vlan invoke wrong dst MAC in TCP packets X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Dennis Yusupoff List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Dec 2009 10:40:04 -0000 The following reply was made to PR kern/141843; it has been noted by GNATS. From: Dennis Yusupoff To: pyunyh@gmail.com Cc: bug-followup@FreeBSD.org Subject: Re: kern/141843: [em] [vlan] Intel txcsum and assigned vlan invoke wrong dst MAC in TCP packets Date: Wed, 30 Dec 2009 13:34:30 +0300 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig42235F443B11536DEDB37A0B Content-Type: multipart/alternative; boundary="------------060207040500050208050702" This is a multi-part message in MIME format. --------------060207040500050208050702 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 29.12.2009 21:51, Pyun YongHyeon ?????: > On Mon, Dec 21, 2009 at 11:53:22PM +0000, linimon@freebsd.org wrote: > =20 >> Old Synopsis: Intel txcsum and assigned vlan invoke wrong dst MAC in T= CP packets >> New Synopsis: [em] [vlan] Intel txcsum and assigned vlan invoke wrong = dst MAC in TCP packets >> >> Responsible-Changed-From-To: freebsd-bugs->freebsd-net >> Responsible-Changed-By: linimon >> Responsible-Changed-When: Mon Dec 21 23:51:33 UTC 2009 >> Responsible-Changed-Why:=20 >> Over to maintainer(s). >> >> http://www.freebsd.org/cgi/query-pr.cgi?pr=3D141843 >> =20 > I'm not sure whether you're seeing one of edge case of em(4)/igb(4) > checksum offload issue. Personally I couldn't reproduce the issue > but I guess the checksum offload/TSO handling might cause > unexpected result. If you disable Tx checksum offload or TSO em(4) > work as expected, right?=20 Not exactly. Only checksum offload gives this issue, TSO on/off doesn't matter. By the way, we checked UDP also and found something interested. For it, we run echo service on server ("|echo dgram udp wait =20 root internal|" in //etc/inetd.conf/) and send strings by "|nc -4 -u server 7|" from client. So...UDP works fine before, while and after "ifconfig vlanX vlan X vlandev em0" command given at server. And the most interesting things is what while server "hangs" for TCP-connections, "establishing" UDP connections between client and server...helps it to "unhang" TCP, so it begins to works correctly. > If so, would you try the following patch > and let me know whether it makes any difference? > > http://people.freebsd.org/~yongari/em.csum_tso.20091229.patch > =20 Doesn't help, same behavior. And moreover, UDP also doesn't "help" and doesn't work so. If you'd like, I could give you an access to this server via SSH, would y= ou? --------------060207040500050208050702 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 29.12.2009 21:51, Pyun YongHyeon пишет: 
On Mon, Dec 21, 2009 at 11:53:22PM +0000, linimon@freeb=
 sd.org wrote:
   
Old Synopsis: Intel txcsum and assigned vlan invoke wr=
 ong dst MAC in TCP packets
 New Synopsis: [em] [vlan] Intel txcsum and assigned vlan invoke wrong dst=
  MAC in TCP packets
 
 Responsible-Changed-From-To: freebsd-bugs->freebsd-net
 Responsible-Changed-By: linimon
 Responsible-Changed-When: Mon Dec 21 23:51:33 UTC 2009
 Responsible-Changed-Why:=20
 Over to maintainer(s).
 
 http://www.freebsd.org/cgi/query-pr.cgi?pr=3D14184=
 3
     
 I'm not sure whether you're seeing one of edge case of em(4)/igb(4)
 checksum offload issue. Personally I couldn't reproduce the issue
 but I guess the checksum offload/TSO handling might cause
 unexpected result. If you disable Tx checksum offload or TSO em(4)
 work as expected, right?
Not exactly.
Only checksum offload gives this issue, TSO on/off doesn't matter.
By the way, we checked UDP also and found something interested.
For it, we run echo service on server ("echo    dgra= m   udp     wait    root    internal"  in <= i>/etc/inetd.conf) and send strings by "nc -4 -u server 7" from client.
So...UDP works fine before, while and after "ifconfig vlanX vlan X vlandev em0" command given at server. And the most interesting things is what while server "hangs" for TCP-connections, "establishing" UDP connections between client and server...helps it to "unhang" TCP, so it begins to works correctly.

If so, would you try the following patch
 and let me know whether it makes any difference?
 
 http://people.freebsd.org/~yongari/em.cs=
 um_tso.20091229.patch
Doesn't help, same behavior. And moreover, UDP also doesn't "help" and doesn't work so.

If you'd like, I could give you an access to this server via SSH, would you?
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