ITEM: CK5373L

Hylafax getty causes respawning too rapidly errors on tty

ENV:
AIX 4.1.4
7015-9xx
128-port async adapter
Telebit Trailblazer modem

DESC:
We are trying to use Hylafax fax software for AIX.  This getty program
allows for incoming faxes and dial-up login sessions on a single tty.
However, when using the Hylafax getty on 128-port adapter ttys we are
getting getty respawning too rapidly errors.  We do not get these
errors using Hylafax on the native serial ports.

ACT:
You have Digiboard's old style metal concentrators off the 128-port
adapter.  These Digiboard RAN (C/CON) have DB-25 ports.

The cabling you have is straight-thru DB-25 to DB-25 cable and the
modems are configured with AT&C1, you have -clocal, no force carrier,
and no altpin (which wouldn't make sense on a DB-25 anyways...) 

/usr/lbin/tty/stty-cxma shows -CD so its not the cable or modem that is
the problem.

Looked in /etc/inittab and see that you're using a custom getty 
program.... The respawning errors only occur with this getty program.
It is a HYLAFAX getty used by the public domain hilafax fax software.
The program doesn't cause any errors when run against ttys on the
native serial port.... Offerred updates to bos.rte.tty and for
devices.mca.ffe1 on tape.  Both were presently at 4.1.4.0.  If these
fix the problem then the problem was an AIX defect with the 128-port
code (since program works on native serial ports).

Here is what you have found out in your testing after applying the
updates to cxmadd and bos.rte.tty:

The HylaFax software does set clocal on the tty when it opens the
port.  It does so for both the tty on the native serial port and the
128-port adapter.  However, getty respawning too rapidly errors only
occur on the 128-port adapter modem.  If you take clocal out of the
HilaFax configuration, it then cannot dial out (write probably blocks).

I suggest this course of action if you need to be able to both dial
out (fax software) and dial into (get a login) on the same tty:

   Set the tty in smit for a fixed baud rate (eg 9600)
   In /etc/uucp/Devices add:
       Direct tty\# - 9600 direct
   pdisable tty1
   cu -ml tty1
   Configure the modem as follows:
   AT&F&C1&D2S0=1Q2E0&W       (use Q1 if your modem doesn't have Q2)
   ~.
   chdev -l tty1 -a login=delay

If you have login=enable and something sets clocal on your tty it 
then makes sense that you would get respawning errors.  There is a
getty running and the tty is told to assume carrier detect is present
(via clocal) so getty will send out a login prompt.  If the modem has
echo enabled it echoes the output back, which AIX takes as a login
prompt, and the modem and tty chatter back and forth until the getty
respawning too rapidly error is logged.

Using login=delay will start a getty (getty -r) which won't send out
a login until 1) carrier detect is present and 2) the caller hits enter

Also, configuring the modem to not echo (ATE0) will stop the chatter
even if AIX sent it a login prompt.  ATQ2 or ATQ1 will turn off the
result codes (like OK and CONNECT) which will work for dial-ins but
may not work with dial-outs if your HilaFax software depends on result
codes like "CONNECT" to determine dial-out progress.  If it does, you
may have to turn result codes back on (ATQ0).

You are looking at the Hylafax source code and it does set clocal on
the port (does it take clocal off after it dials out?)  You're going
to try putting a terminal on the port instead of a modem, suspecting
the application may be sending AT&C0 or some other incorrect setup 
string to the modem.

Searched the web and found HylaFax versions for AIX... Looks like
there are several versions of the program and list of updates and
bug fixes that may address what you are seeing...

ACT:
Michael found and corrected the cause of the respawning too rapidly
errors when using the Hylafax software.

If the tty was set to login=enable and he would vi /etc/inittab
and change /usr/sbin/getty to the hylafax getty program, he would
get init respawning too rapidly errors.

If he used chitab to update the inittab the problem would not occur.
If he set the tty up with login=disable and vi'd /etc/inittab the
respawning errors did not occur either.

If the tty had login=enable and he would just vi /etc/inittab and
change the entry, init sent SIGTERM (signal 15) to the Hylafax
getty which would clean up the tty and exit gracefully.



Support Line: Hylafax getty causes respawning too rapidly errors on tty ITEM: CK5373L

Dated: January 1997 Category: N/A

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