modems, security

Carl S. Gutekunst csg at pyramid.pyramid.com
Sat Jul 8 07:57:56 AEST 1989


>I have several Hayes-compatible modems on my system. I'd like to automati-
>cally program them whenever the system reboots.  Question is, how do I talk
>to a modem from the backside?

I assume you mean a dialin modem. You would need to write a small C program
that opens up the device and sets the parameters; I'm not aware of any off-
the-shelf package that will do want you want. (Most programs that set up
modems also want to *dial* the modem.) In addition, you'll have to use nlditp
to override the modem's DCD line while your program runs. All of this could
go into your /etc/brc, something like:

	nlditp -h 0x0003 /dev/itp40 /dev/ttyi00 /etc/mcode/i.out
	modem_setup /dev/ttyi00
	modem_setup /dev/ttyi01
	nlditp -h 0x0000 /dev/itp40 /dev/ttyi00 /etc/mcode/i.out

We have in the lab a dialin/dialout tty driver, similar to what Sun has been
shipping since SunOS 3.2. (OK, so we're a little slow, alright?) This will be
available sometime after OSx 5.0, and it will eliminate the need to fiddle
with nlditp.

>Is it possible to monitor an incoming serial line by any means other than
>putting a printer on the port?

People have written various tools to do this, mostly involving rummaging about
in /dev/kmem. There is no universally defined way.

>Does anyone know how to keep login from printing BADTTYLOGIN messages to the
>console?  I want them in my /usr/adm/badlog, but NOT on my console.

In OSx <= 4.4, no. It's wired into /bin/login. OSx 5.0 works like 4.3BSD; all
these messages are controlled via syslogd(8), so you can route them wherever
you want in /etc/syslog.conf. This assumes you run the BSD init/getty/login;
there is no syslog in System VR3.

<csg>



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