Subject: Re: PPP thoughts
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: None <itojun@iijlab.net>
List: tech-net
Date: 10/29/1999 10:09:59
>I've been corresponding with someone from Waterloo (you know who you
>are, speak up if you care to) about my PPPoE code.  Falling out of this
>discussion are some thoughts on PPP in general that I'd like to bounce
>off you people.
>Specifically, it seems to me that the PPP setup scheme is rather
>backward.  You don't tell a PPP device to attach to a tty line, you
>tell a tty line to have a PPP device attach to it.  This strikes me as
>rather upside down, and in particular it makes PPPoE comparatively
>difficult.

	I think this is because ppp runs on top of tty line, not the other
	way around.

>What would the general reaction be to reworking the PPP glue so that
>each PPP device can be reached by a file descriptor (perhaps a
>special-purpose socket, perhaps an open device node - the details don't
>really matter), and then have backend modules that the PPP device can
>talk to - one for ttys, one for Ethernet?  Possibly even a
>pseudo-device backend, the PPP-backend analog of the tun and pty
>drivers, which would allow easy and clean development of userland PPP
>implementations (both for people who want userland PPP in general, and
>for people playing with doing PPP over unusual media)?

	Can't you just have pseudo tty device for PPPoE, configure it with
	ioctls (like ethernet src/dst, interface etc) and attach ppp onto it?
	May not be politically correct but PPPoE design *is* somewhat strange
	by itself anyway...

itojun