Subject: Re: [PATCH 00/03][RESUBMIT] net: EtherIP tunnel driver

From: Joerg Roedel <[email-masked]>
Date: Mon, 25 Sep 2006 10:32:49 +0200

On Sun, Sep 24, 2006 at 09:07:43PM -0400, [email-masked] wrote:
> On Sat, 23 Sep 2006 15:27:36 +0200, Joerg Roedel said:
> 
> > (I assume you are speaking of the position of the 3 in the header). The
> > RFC is not clear at this point. It defines that the first 4 bits in the
> > 16 bit Ethernet header MUST be 0011. But it don't defines the
> > byteorder of that 16 bit word nor if the least or most significant bit
> > comes first.
> 
> Unless stated otherwise, it's pretty safe to assume that all "on the wire" data
> mentioned in an RFC is in 'network byte order'.  That's why hton*() and ntoh*()
> functions exist...

Yes. Thats what the OpenBSD people did :-)
The problem with the header is the bitorder. The OpenBSD people assumed
that the least significant bits come first in the 16-bit header.

> Is there something in the RFC that suggests that a byte order other than
> 'network order' is possible/acceptable there?

No. The RFC states nothing at all about byte- or bitorder. That is why
the RFC is ambigious at this point.