Re: flexfax: faxgetty as a callback server.

[Nico Garcia <raoul@cirl.meei.harvard.edu>]

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On Sun, 2 Nov 1997 Matthias.Apitz@SOFTCON.de wrote:

> Nico Garcia wrote:
>     
>     On Fri, 31 Oct 1997, Lorenzo M. Catucci wrote:
>     
>     > Now, mgetty have two nice features, which are autoppp, and callback.
>     > autoppp means I don't have to set up a ppp account, with a common
>     > password, but rather have mgetty recognize ppp traffic, start pppd with
>     > the login and pap options, and all is done with the standard username and
>     > password. Callback means... you know that. Now, I have managed to have
>     
>     Hmmm. Under SunOS, I set up distinct PPP accounts for my users. This
>     permits me to log, via utmp, when they call in as themselves and when
>     they call in as PPP users.
>     
>     There are a gazillion ways to do this, of course....
> 
> Yes, but the question was not to *login* into the system.
> What Lorenzo wants (and what I'ld call a good new feature
> for HylaFAX's faxgetty(1M)) is that faxgetty(1M) accepts
> a call, checks if it is a data call and checks also if
> PPP-packets are coming in from the caller and (if so) directly
> launches a PPP-daemon rather than the normal system getty or
> ttymon. The problem with that is that faxgetty(1M) has to
> read a few chars from the modem to check if they are PPP-data
> and if not has to hand-over these characters to the normal
> system's getty (e.g. push them back to modem fd to let
> getty read them which isn't possible without integrating
> the getty into faxgetty(1M)). With PPP the authentication
> could be done directly using PAP or CHAP.

Fair enough, but this completely replaces the getty normally
associated with a dial-up line with a pppd. That means that that line
can no longer accept simple serial line communications such as Kermit,
Hyperterminal, White Knight, UUCP, etc. That's why I think it's much
more flexible to set this up as a configuration per-user, instead of as
a per modem-line setup. 

It might be set up as some options traditionally are, where if you
don't interrupt it in 5 seconds it falls through and gives you a PPP
access or, in Lorenzo's case, a dialback....

> On my system at home I've one faxgetty(1M) running which launches
> directly the PPP-daemon (instead of ttymon). I simply
> patched the name "/usr/lib/saf/ttymon" to "/usr/local/ppp/pppd"
> in a copy of sbin/faxgetty. The "modem" on this line is a
> ZyXEL 2864I ISDN-TA and the Cisco 2503 in my company uses
> CHAP to dial-in via PPP into my system at home. This line
> can't be used for "normal" logins of course.

Exactly. I think a standard SunOS serial line is more useful having
straight shell capability, to permit people to read their email with
something simple like Kermit instead of futzing with their calling
machine's network setups and using PPP.

>     What you want, I think, is to have a shell script as your dialup login
>     shell: this shell would then run off and start up the callback feature.

Except that Lorenzo wants to have the same account names for his users
as for their dialup use: this makes replacing their login shells
problematic at best. Better to have some sort of option called from
their .login or .profile file, something to then fire off the callback
feature.

			Nico Garcia
			Engineer, CIRL 
			Mass. Eye and Ear Infirmary
			raoul@cirl.meei.harvard.edu

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