From owner-freebsd-hackers  Mon Dec  4 23:09:06 1995
Return-Path: owner-hackers
Received: (from root@localhost)
          by freefall.freebsd.org (8.6.12/8.6.6) id XAA14718
          for hackers-outgoing; Mon, 4 Dec 1995 23:09:06 -0800
Received: from zibbi.mikom.csir.co.za (zibbi.mikom.csir.co.za [146.64.24.58])
          by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id XAA14694
          ; Mon, 4 Dec 1995 23:07:48 -0800
Received: (from jhay@localhost) by zibbi.mikom.csir.co.za (8.6.12/8.6.9) id JAA09818; Tue, 5 Dec 1995 09:04:52 +0200
From: John Hay <jhay@mikom.csir.co.za>
Message-Id: <199512050704.JAA09818@zibbi.mikom.csir.co.za>
Subject: Re: ipx on 802.3
To: terry@lambert.org (Terry Lambert)
Date: Tue, 5 Dec 1995 09:04:52 +0200 (SAT)
Cc: wollman@freebsd.org, hackers@freebsd.org (FreeBSD-hackers)
In-Reply-To: <199512042332.QAA00450@phaeton.artisoft.com> from "Terry Lambert" at Dec 4, 95 04:32:23 pm
X-Mailer: ELM [version 2.4 PL24 ME8b]
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Content-Length: 2051      
Sender: owner-hackers@freebsd.org
Precedence: bulk

>> I am thinking about implementing it. The biggest problem to me seems to
>> be selecting between ETHERNET_II and 802.3 form the userlevel. I thought
>> of using IFF_LINK(0,1,2) so that it would be easy to specify with ifconfig.
>> But then I went to look in /sys/i386/isa and all of them are used by the
>> network device drivers. :-(

Garrett's suggestion:
>
> So, do everyone a favor and re-write them to use the if_phys entry in
> the ifnet struct I added for specifically this purpose.  Then you can
> use the IFF_LINK flags for this purpose.  (Given that they were called
> IFF_LLC* in Net/2, well, you guess why they were originally added.)

Terry's suggestion:
> 
> I believe it is possible to compare the address family in the file
> /sys/net/if.c in the function ifioctl() for "case SIOCSIFFLAGS"
> (at about line 531) to determin if AF_IPX is being used, and if so,
> interpret the values of IFF_LINK[0-2] differently.
> 
> This would be a simple hack compared to fixing all the code to
> do the right thing for the interface flags.
>

Having read both Terry's and Garrett's sugestions, here are my thoughts
for Terry's suggestion:

This does mean that if you want to use the IFF_LINK in a device driver,
you will have to do two ifconfig's, one "ifconfig xxx ipx xxxxx linkx"
to set 802.3 mode and one without the ipx to set a link option inside
the device driver.

At the moment the only device drivers that use all three IFF_LINK options
are /sys/i386/isa/if_ep.c and /sys/pci/if_vx.c. The rest are only using
one and in some cases two of the IFF_LINK options. So maybe we can change
those that only use one, to use IFF_LINK2 which allready have an alias
IFF_ALTPHYS in /sys/net/if.c?

And here are my thoughts to Garrett's suggestion:

This sounds like the cleanest option, but I would first like to figure
out how much work this will be. I can think of at least one user-level
program ifconfig that will have to be changed. Are there others? And
what should the option for ifconfig be called?

John
-- 
John Hay -- John.Hay@csir.co.za