Subject: Re: uugetty for NetBSD
To: Curt Sampson <cjs@portal.ca>
From: Perry E. Metzger <perry@piermont.com>
List: tech-kern
Date: 11/11/1996 14:18:36
Curt Sampson writes:
> On Mon, 11 Nov 1996, Perry E. Metzger wrote:
> > > Yes. Flock doesn't work on character devices.
> > 
> > Why don't we just fix that?
> 
> >From my quick reading of the source: flock() just calls lockf()
> with a start of zero and a range of the length of the file. (Lockf
> is in the VFS layer.) Currently there is no lockf for device-type
> vnodes. 

We could do something "different" for char device files if need be.

> Oh, and the other reason? Most every program in the world that uses
> serial ports uses LCK..ttyXX locking.

Yeah, but there are reasons why its not the best idea on
earth. Security problems associated with needing the sgid UUCP
stuff. Lack of automatic cleanup when processes die (this is a real
problem -- every try explaining to someone over the phone how to
remove a stale lock file?). etc, etc.

> Thus, getty really should be
> able to do this so that uucp, mgetty, ixocico, kermit, tip, etc.
> all don't have to be changed just to accommodate NetBSD.

I don't think we have to *force* them to change, but it would be neat
to lead here, technically. Locking really shouldn't be done with lock
files.

Perry