Reproducible modem bug in 3005 and 2006

Chip Salzenberg chip at tct.com
Tue Jun 18 02:11:29 AEST 1991


According to jfh at rpp386.cactus.org (John F Haugh II):
>It sounds to me like the TTY device driver is letting the open succeed
>if a character is present, or else the modem is doing strange things
>with the signals.

Actually, I've managed to reproduce a serious and basic bug in getty.
Try this on a system at 3005 or 2006:

 1. Set up a line in "share" mode (getty -u).
 2. Start a UUCP dialout on that line.
 3. Kill the uucico before it makes a connection.

You will see that getty locks the port and never lets go.

This problem is apparently a result of getty's not taking care to turn
off CLOCAL before making the possibly blocking open() call.

This problem would be less harmful if getty would give up when it sees
no response for, say, five minutes.

I gave up trying to get satisfaction from defect support on this bug,
and have resorted to writing my own uugetty.  I plan to post source
code for my uugetty as soon as I get permission from higher-ups.
-- 
Chip Salzenberg at Teltronics/TCT     <chip at tct.com>, <uunet!pdn!tct!chip>
 "You can call Usenet a democracy if you want to.  You can call it a
  totalitarian dictatorship run by space aliens and the ghost of Elvis.
  It doesn't matter either way."  -- Dave Mack



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