Re: [XonX-Users] Xterm SUID?

[Torrey L. <to...@mr...>]

At 7:08 PM -0800 12/22/04, John Davidorff Pell wrote:
>Hi!
>
>I've got a few questions:
>1) Why is Xterm SUID?

The short answer is so that it can chown the pseudo tty that it uses. 
The long answer is that it does not absolutely need to do this and in 
any case there are non-SUID ways to do this. Apple's X11 does not 
have an SUID xterm and it just fails to chown the tty. The main 
symptom of this is that if you use "who" you will not see your xterm 
sessions listed. On the other hand if you open up a bunch of SUID 
xterm or Terminal.app windows you will see them all listed in who. 
Terminal.app is not SUID so there is clearly another way to do this. 
Most OS'es have provided some non-SUID way to do this, but this is 
not standard. If we knew how to do this on Mac OS X we could have 
xterm do this instead.

>2) Shouldn't that be explicitly disabled on Darwin?

Perhaps. We left it that way since it had always been that way and it 
does modify behavior if you change it. You can change this yourself 
by putting the following line in your xc/config/cf/host.def file 
before you build:

#define InstallXtermSetUID     YES

>3) Shouldn't the default be not-SUID, and systems that require it 
>explicitly set it to be SUID?

Perhaps, but since the Xserver is also SUID on many platforms it 
sticks out less than as the only SUID X11 program on Mac OS X.

--Torrey