From owner-freebsd-hackers  Fri Mar  7 14:19:23 2003
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 2BCDB37B406
	for <freebsd-hackers@FreeBSD.ORG>; Fri,  7 Mar 2003 14:19:22 -0800 (PST)
Received: from cirb503493.alcatel.com.au (c18609.belrs1.nsw.optusnet.com.au [210.49.80.204])
	by mx1.FreeBSD.org (Postfix) with ESMTP id D279943F93
	for <freebsd-hackers@FreeBSD.ORG>; Fri,  7 Mar 2003 14:19:19 -0800 (PST)
	(envelope-from peterjeremy@optushome.com.au)
Received: from cirb503493.alcatel.com.au (localhost.alcatel.com.au [127.0.0.1])
	by cirb503493.alcatel.com.au (8.12.6/8.12.5) with ESMTP id h27MJDiM099042;
	Sat, 8 Mar 2003 09:19:13 +1100 (EST)
	(envelope-from jeremyp@cirb503493.alcatel.com.au)
Received: (from jeremyp@localhost)
	by cirb503493.alcatel.com.au (8.12.6/8.12.5/Submit) id h27MJ6xc099040;
	Sat, 8 Mar 2003 09:19:06 +1100 (EST)
Date: Sat, 8 Mar 2003 09:19:06 +1100
From: Peter Jeremy <peterjeremy@optushome.com.au>
To: Terry Lambert <tlambert2@mindspring.com>
Cc: freebsd-hackers@FreeBSD.ORG
Subject: Re: Realtek
Message-ID: <20030307221905.GA98940@cirb503493.alcatel.com.au>
References: <20030306230206.70461.qmail@web14913.mail.yahoo.com> <200303062136.44471.wes@softweyr.com> <3E68E859.EAB20A71@mindspring.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <3E68E859.EAB20A71@mindspring.com>
User-Agent: Mutt/1.4i
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-hackers.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-hackers>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-hackers>
X-Loop: FreeBSD.ORG

On Fri, Mar 07, 2003 at 10:43:37AM -0800, Terry Lambert wrote:
>And TCP/IP headers are not an even multiple of the alignment boundary
>(4 bytes, actually).  So every packet the card DMA's in has to be
>copied so that access to the TCP packet contents are aligned.

Last time I looked at TCP/IP, the header lengths were all defined
in 4-byte units so they must be a multiple of 4 bytes by definition.
Maybe you are referring to the Ethernet header - which is 14 bytes
long (18 bytes in a VLAN trunk).

Peter

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message