From owner-freebsd-net@FreeBSD.ORG  Thu Oct 11 02:07:14 2012
Return-Path: <owner-freebsd-net@FreeBSD.ORG>
Delivered-To: net@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
 by hub.freebsd.org (Postfix) with ESMTP id C63D2A2A;
 Thu, 11 Oct 2012 02:07:14 +0000 (UTC)
 (envelope-from mdounin@mdounin.ru)
Received: from mdounin.cust.ramtel.ru (mdounin.cust.ramtel.ru [81.19.69.81])
 by mx1.freebsd.org (Postfix) with ESMTP id 78AC88FC1B;
 Thu, 11 Oct 2012 02:07:14 +0000 (UTC)
Received: from mdounin.ru (mdounin.cust.ramtel.ru [81.19.69.81])
 by mdounin.cust.ramtel.ru (Postfix) with ESMTP id E0C0C1702D;
 Thu, 11 Oct 2012 06:07:12 +0400 (MSK)
Date: Thu, 11 Oct 2012 06:07:12 +0400
From: Maxim Dounin <mdounin@mdounin.ru>
To: Gleb Smirnoff <glebius@FreeBSD.org>
Subject: Re: [CFT/Review] net byte order for AF_INET
Message-ID: <20121011020712.GU40452@mdounin.ru>
References: <20121009154128.GU34622@FreeBSD.org>
 <20121010195842.GH34622@FreeBSD.org>
 <20121010222651.GR40452@mdounin.ru>
 <20121010233404.GI34622@glebius.int.ru>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20121010233404.GI34622@glebius.int.ru>
User-Agent: Mutt/1.5.21 (2010-09-15)
Cc: net@FreeBSD.org
X-BeenThere: freebsd-net@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-net>,
 <mailto:freebsd-net-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net>
List-Post: <mailto:freebsd-net@freebsd.org>
List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-net>,
 <mailto:freebsd-net-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 11 Oct 2012 02:07:14 -0000

Hello!

On Thu, Oct 11, 2012 at 03:34:04AM +0400, Gleb Smirnoff wrote:

[...]

> This is de facto standard for raw sockets in most OS-es. Byte order
> in raw socket is host. And this is the same behavior we had before
> the patch. So no reason for extra comments.

As I already pointed out (in an off-list message), many consider 
this as a "known bug" in many OSes instead.

E.g. here is a quote from /usr/ports/net/openospfd/files/patch-ospfd_packet.c
patch:

@@ -70,7 +70,12 @@
        ip_hdr.ip_v = IPVERSION;
        ip_hdr.ip_hl = sizeof(ip_hdr) >> 2;
        ip_hdr.ip_tos = IPTOS_PREC_INTERNETCONTROL;
+#if defined(__FreeBSD__) || defined(__NetBSD__)
+       /* FreeBSD/NetBSD wants the length in the native host byte order. */
+       ip_hdr.ip_len = len + sizeof(ip_hdr);
+#else
        ip_hdr.ip_len = htons(len + sizeof(ip_hdr));
+#endif

I would suggests it at least deserves a comment, and probably API 
change/fix too.

[...]

> --- sys/netinet/raw_ip.c	(revision 241405)
> +++ sys/netinet/raw_ip.c	(working copy)
> @@ -292,7 +292,7 @@
>  	 * not modify the packet except for some
>  	 * byte order swaps.
>  	 */
> -	ip->ip_len += off;
> +	ip->ip_len = ntohs(ip->ip_len) + off;

So, you've moved a switch to host byteorder into rip_input().  
What about ip->ip_off then?

Note that this may also need some adjustments for protocols which use
rip_output() but not rip_input() (or vice versa).

[...]

-- 
Maxim Dounin