Mount /cdrom as non-root user - does this actually work for anyone?

[Stacey Roberts]

Hello,
     Thanks for the reply.

----- Original Message -----
From: "Tom McLaughlin <tmclaugh at sdf.lonestar.org>"
To: To Stacey Roberts
Date: Sun, 04 Jan, 2004 21:54 GMT
Subject: Re: Mount /cdrom as non-root user - does this actually work for anyone?

> On Sun, 2004-01-04 at 08:31, Stacey Roberts wrote:
> > Hello,
> >     Thanks for the reply.
> > 
> > ----- Original Message -----
> > From: "Tom McLaughlin <tmclaugh at sdf.lonestar.org>"
> > To: To Stacey Roberts
> > Date: Sun, 04 Jan, 2004 05:48 GMT
> > Subject: Re: Mount /cdrom as non-root user - does this actually work for anyone?
> > 
> > > On Sat, 2004-01-03 at 20:13, Stacey Roberts wrote:
> > > > Hello,
> > > >      Thanks for the reply..,
> > > > 
> > > > ----- Original Message -----
> > > > From: "Gautam Gopalakrishnan <ggop at madras.dyndns.org>"
> > > > To: To Stacey Roberts
> > > > Date: Sun, 04 Jan, 2004 00:59 GMT
> > > > Subject: Re: Mount /cdrom as non-root user - does this actually work for anyone?
> > > > 
> > > > > On Sun, Jan 04, 2004 at 12:53:52AM +0000, Stacey Roberts wrote:
> > > > > > Hello,
> > > > > > As root I can mount and read the CD fine.., checking for non-root user:
> > > > > > exit
> > > > > > ~ $ mount /cdrom
> > > > > > cd9660: /dev/acd0c: Operation not permitted
> > > > > > ~ $ mount -t cd9660 /dev/acd0c ~/cdrom
> > > > > > cd9660: /dev/acd0c: Operation not permitted
> > > > > > ~ $
> > > > > > 
> > > > > > Attempting to mount to mount-point in user home dir:
> > > > > > ~ $ cd ~
> > > > > > ~ $ pwd
> > > > > > /home/stacey
> > > > > > ~ $ ls -ltra cdrom
> > > > > > total 6
> > > > > > drwxr-xr-x 2 stacey stacey 512 Jan 3 23:50 ./
> > > > > > drwxr-xr-x 31 stacey stacey 2560 Jan 3 23:50 ../
> > > > > > ~ $ mount -t cd9660 /dev/acd0c ~/cdrom
> > > > > > cd9660: /dev/acd0c: Operation not permitted
> > > > > > ~ $
> > > > > 
> > > > > chmod +s /sbin/umount /sbin/mount
> > > > > 
> > > > > works fine for me (without any other changes necessary). Don't know
> > > > > if it's the recommended procedure though.
> > > > > 
> > > > 
> > > > Nor I, to be honest.., I'm not sure about setting the suid bit on mount.., Given that the HandBook provides what I thought would have been straight-forward instructions on what (presumably) is I hoped is a simple procedure.., I'd not want to start making undocumented config changes.
> > > > 
> > > > Thanks all the same for taking the time to respond.
> > > > 
> > > > Regards,
> > > > 
> > > > Stacey
> > > > 
> > > > > Gautam
> > > > > 
> > > 
> > > Stacey, what are permissions of /dev/acd0c?  The handbook example
> > > changes the permissions of a SCSI cdrom.  I made the mistake of not
> > > noticing this when I first tried to do make my cdrom user mountable.
> > > 
> > 
> > $ ls -la /dev/acd*
> > crw-r-----  4 root  operator  117,   0 Nov  9 14:21 /dev/acd0a
> > crw-r-----  4 root  operator  117,   0 Nov  9 14:21 /dev/acd0c
> > $
> > 
> > That's what the permissions are like after running through the procedure in the HandBook. On that note, fr the record, on all machines, there are IDE CDROM drives and one IDE CD-RW drive that I've got here.
> > 
> > Thanks again.
> > 
> > Regards,
> > 
> > Stacey
> > 
> > > Tom
> > > 
> 
> Stacey, do `chmod 666 /dev/acd0c`.  That will give the first IDE cdrom
> drive the correct permissions.  You should be able to pop in a disk and
> mount it in your directory then.
> 
> [tom at compass tom]$ ls -al /dev/acd*
> crw-rw-rw-  4 root  operator  117,   0 Dec 18 00:53 /dev/acd0a
> crw-rw-rw-  4 root  operator  117,   0 Dec 18 00:53 /dev/acd0c
> ...
> crw-rw-rw-  4 root  operator  117,   8 Dec 18 00:53 /dev/acd1a
> crw-rw-rw-  4 root  operator  117,   8 Dec 18 00:53 /dev/acd1c
> 

Yes., I tried this in the end (well., 644 instead of 666) and I am now able to mount the cd-rw drive as an ordinary user, as well as the cdrom drives on the others.., 

However, this *does* seem to make the whole deal about adding users to the operator group kind of redundant, it appears.., I could have left users where they were and done the above and it would have worked all the same..,

Also, if the HandBook has only procedures that would work for only SCSI drives, who do I contact in order for some procedure relevant to those users in the community that would want to / need to do the same for hosts with IDE drives?

Thanks again for taking the time, and the patience..,

Regards,

Stacey

> 
> Tom
> 

-- 
Stacey Roberts
B. Sc (HONS) Computer Science

Web: www.vickiandstacey.com