HEAD UP: non-MPSAFE network drivers to be disabled (was: 8.0
network stack MPsafety goals (fwd))
rwatson at FreeBSD.org
Mon May 26 15:26:15 UTC 2008
On Mon, 26 May 2008, Bruce M. Simpson wrote:
>> Given that this is (a) 2008 and (b) 8.x we're talking about, are there
>> really that many consumers of SLIP to warrant it being carried forward at
> It's kind of a basic. [C]SLIP has been historically handy to have around for
> situations which warrant it. Mind you, given that we have had tun(4) in the
> tree for years now, a userland implementation of SLIP is possible.
> As with all of these things it's down to someone sitting down and doing it.
> I'm not volunteering to support any of this as I don't use it myself (got
> enough on my plate), merely pointing out that support for SLIP in a system
> is something many people have taken for granted over the years, and for
> prototyping something or providing IP over a simple serial link without the
> configuration overhead of PPP, SLIP is something someone might be using.
> P.S. ahc(4) is commodity hardware, I think it can stay right where it is
My suspicion is that getting SLIP basically working in userspace is fairly
straight forward, although I'm not sure how well-suited some of our current
admin tools (slattach, etc) are for the purpose. If the new tty code
maintains support for line disciplines, updating the existing SLIP code and
adding locking code would probably be an equally sized (or shorter) task.
SLIP has its subtleties, but the current implementation is relatively
straight-forward, well-documented, etc.
Robert N M Watson
University of Cambridge
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