From owner-freebsd-bugs@FreeBSD.ORG Sun Jan 13 16:30:02 2008 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2D02E16A46D for ; Sun, 13 Jan 2008 16:30:02 +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 105B513C4D9 for ; Sun, 13 Jan 2008 16:30:02 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.2/8.14.2) with ESMTP id m0DGU1Ig034744 for ; Sun, 13 Jan 2008 16:30:01 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.2/8.14.1/Submit) id m0DGU1CI034743; Sun, 13 Jan 2008 16:30:01 GMT (envelope-from gnats) Resent-Date: Sun, 13 Jan 2008 16:30:01 GMT Resent-Message-Id: <200801131630.m0DGU1CI034743@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Bernd Heller Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6172F16A417 for ; Sun, 13 Jan 2008 16:28:29 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (www.freebsd.org [IPv6:2001:4f8:fff6::21]) by mx1.freebsd.org (Postfix) with ESMTP id 553C313C458 for ; Sun, 13 Jan 2008 16:28:29 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.14.2/8.14.2) with ESMTP id m0DGRGjd098114 for ; Sun, 13 Jan 2008 16:27:16 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.14.2/8.14.1/Submit) id m0DGRGAV098112; Sun, 13 Jan 2008 16:27:16 GMT (envelope-from nobody) Message-Id: <200801131627.m0DGRGAV098112@www.freebsd.org> Date: Sun, 13 Jan 2008 16:27:16 GMT From: Bernd Heller To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: kern/119635: Bad UDP packet checksum with em(4) and rxcsum/txcsum enabled X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 13 Jan 2008 16:30:02 -0000 >Number: 119635 >Category: kern >Synopsis: Bad UDP packet checksum with em(4) and rxcsum/txcsum enabled >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Sun Jan 13 16:30:01 UTC 2008 >Closed-Date: >Last-Modified: >Originator: Bernd Heller >Release: 7.0-RC1 >Organization: >Environment: FreeBSD 7.0-RC1 FreeBSD 7.0-RC1 #0: Mon Dec 24 10:10:07 UTC 2007 root@driscoll.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC amd64 >Description: I have an Intel Pro/1000 PT Desktop Adapter network card in that machine, and by default the em(4) driver has rxcsum/txcsum enabled. But the checksums for some UDP packets generated this way are wrong. I noticed this when trying to run avahi-daemon. It sends UDP multicast packets, but they were never recognized on the network. Only when using tcpdump did I notice the bad checksums. After I disabled rxcsum/txcsum on the interface all was working perfectly. I could reproduce the same issue in a VMware machine using FreeBSD 7.0-RC1 i386 and amd64. 6.2 seems to be unaffected. >How-To-Repeat: Run avahi-daemon to publish any services (it will do so by default) and analyze the UDP packages sent out. >Fix: Workaround: disable rxcsum/txcsum on the interface. >Release-Note: >Audit-Trail: >Unformatted: