Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!ames!amdahl!shs
From: shs@uts.amdahl.com (Steve Schoettler)
Newsgroups: comp.sources.d
Subject: Re: getty/login for callback
Summary: Use tip!
Keywords: tip getty login
Message-ID: <14U6Pf88Sj1010WE=r6@amdahl.uts.amdahl.com>
Date: 4 Apr 89 18:57:09 GMT
References: <180001@mechp10.UUCP> <13853@rpp386.Dallas.TX.US> <797@twwells.uucp> <597@peritek.UUCP>
Reply-To: shs@amdahl.uts.amdahl.com (Steve Schoettler)
Distribution: usa
Organization: Amdahl Corporation, Sunnyvale CA
Lines: 45

In article <597@peritek.UUCP> dig@peritek.UUCP (Dave Gotwisner) writes:
>In article <797@twwells.uucp>, bill@twwells.uucp (T. William Wells) writes:
>> : In article <180001@mechp10.UUCP> klein@mechp10.UUCP (Greg Klein) writes:
>> : >I need the source code for getty(1) and login(1) or something similar if
>> : >a public domain version don't exist.  I want to modify them to spawn ct(1)
>> : >instead of a shell to dial back the user.  Please email or post (to
>> : >comp.sources.d ?). Thanks.
>> 
>    We had something like this at my old job.  It was done without modifying
>any UNIX software.  They had a program which was inserted between
>init and getty on the dialup line.  Both system 5 and BSD provide the
>sysadmin to specify something to be called by init on a line.  What it did
>was to maintain a list of authorized dialin users and phone numbers
>(all encrypted, of course).  You phoned in, typed a "login name", it looked
>in the file, hung up the phone, and called back the number associated with
>the "login name".  It then exec'ed getty.  The program originally ran on an
>ancient Version 6 system (PDP 11/70), and was converted to run on Pyramid's
>system without too much difficulty.

I wrote something like this by modifying the standard unix tip program.
This allowed taking advantage of a standard text file format for storing phone
numbers, baud rates, etc.  This also allows operation under a variety of
modems (hayes and ventel).
The program was invoked with "ntip myname", where there was an entry for
myname in /etc/remote.

All you have to do is find the place where tip makes the connection,
and fork a shell, setting stdin and stdout to the serial port.  I
think the command I actually used inside my exec was "rlogin localhost",
because I had trouble creating a getty on the dial out line.  You can
set stdin and stdout of the shell with the dup() command.

Good luck!

Steve




-- 

        Steve Schoettler
        shs@uts.amdahl.com
        {sun,decwrl,pyramid,ames,uunet}!amdahl!shs
        Amdahl Corp., M/S 213, 1250 E. Arques Ave, Sunnyvale, CA 94088