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Path: utzoo!linus!philabs!seismo!hao!hplabs!sri-unix!Michael.Young@cmu-cs-g
From: Michael.Young%cmu-cs-g@sri-unix.UUCP
Newsgroups: net.unix-wizards
Subject: Re: ioctl-ability, the TIOCCDTR problem
Message-ID: <2415@sri-arpa.UUCP>
Date: Wed, 22-Jun-83 09:51:04 EDT
Article-I.D.: sri-arpa.2415
Posted: Wed Jun 22 09:51:04 1983
Date-Received: Fri, 24-Jun-83 00:11:23 EDT
Lines: 10

One good reason for allowing ioctls on a tty you have a writeable
descriptor for is to allow setuid-someone-else (but maybe not root)
programs to do neat things for you (like present a visual display
of some sort).  It seems to me that writing on someone else's terminal
has almost as much negative potential as ioctl'ing it.  Don't
let your tty be writeable.  [With 4.2, one ought to be able to
set up an ipc port which can provide controlled (by tty owner)
access to one's tty.]

			Michael