Date: Tue, 06 Dec 2011 11:47:25 +0000 From: Arthur Chance <freebsd@qeng-ho.org> To: "Ronald F. Guilmette" <rfg@tristatelogic.com> Cc: freebsd-questions@freebsd.org Subject: Re: drivin' me nuts: permissions and cdda2wav Message-ID: <4EDE00CD.6070507@qeng-ho.org> In-Reply-To: <66927.1323170567@tristatelogic.com> References: <66927.1323170567@tristatelogic.com>
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On 12/06/11 11:22, Ronald F. Guilmette wrote:
> With a pre-recorded CD in the drive, the following works fine for me when
> I'm root:
>
> cdda2wav -D 0,0,0 -B
>
> My question is: What do I need to do in order to make this work also
> when executed from a non-root account?
>
> Here's what I get when I try to do the above from a non-root account:
>
> cdda2wav: Permission denied. Cannot open or use SCSI driver.
> cdda2wav: For possible targets try 'cdda2wav -scanbus'. Make sure you are root.
> Probably you did not define your SCSI device.
> Set the CDDA_DEVICE environment variable or use the -D option.
> You can also define the default device in the Makefile.
> For possible transport specifiers try 'cdda2wav dev=help'.
>
> Effing hell! I've tried just about everything I can think of off the top
> of my head to beat this and nothing works. I've tried chmod 0660 /dev/pass*
> (and yes, the account I'm trying these experiments from _is_ a member of the
> `operator' group), but that didn't help a bit.
>
> And before anybody asks, let me say that yes, I _do_ have:
>
> atapicam_load="YES"
>
> in my /boot/loader.conf file.
>
> So how exactly does one adjust the permissions on one of these atamicam
> pseudo-SCSI devices. Where are they underneath /dev ? Please excuse my
> ignorance, but I just don't know.
>
> <<gnashing of teeth sound>>
I've just been through the same experience getting cdparanoia to work
for a non-root user under REL 8.2p4. Note that I have the ahci module
loaded so my cd is /dev/cd0.
You need write access to /dev/cd0 plus the corresponding /dev/passN (use
camcontrol devlist to find out which) *and* /dev/xpt0.
From my /etc/devfs.conf
own cd0 root:operator
perm cd0 0660
link cd0 cdrom
perm xpt0 0660
perm pass5 0660
This is the relevant part my machine's /dev. I'm in operator group.
arthur@fileserver> ls -l /dev/{cd,pass,xpt}*
crw-rw---- 1 root operator 0, 97 Nov 23 16:24 /dev/cd0
lrwxr-xr-x 1 root wheel 3 Dec 2 16:08 /dev/cdrom -> cd0
crw------- 1 root operator 0, 91 Nov 23 16:24 /dev/pass0
crw------- 1 root operator 0, 92 Nov 23 16:24 /dev/pass1
crw------- 1 root operator 0, 93 Nov 23 16:24 /dev/pass2
crw------- 1 root operator 0, 94 Nov 23 16:24 /dev/pass3
crw------- 1 root operator 0, 95 Nov 23 16:24 /dev/pass4
crw-rw---- 1 root operator 0, 96 Nov 23 16:24 /dev/pass5
crw------- 1 root operator 0, 113 Nov 23 16:24 /dev/pass6
crw------- 1 root operator 0, 115 Nov 23 16:24 /dev/pass7
crw------- 1 root operator 0, 116 Nov 23 16:24 /dev/pass8
crw------- 1 root operator 0, 118 Nov 23 16:24 /dev/pass9
crw-rw---- 1 root operator 0, 61 Nov 23 16:24 /dev/xpt0
And how to find which /dev/passN corresponds to the cd drive:
arthur@fileserver> camcontrol devlist | grep cd
<ASUS DRW-2014S1T 1.00> at scbus7 target 0 lun 0 (cd0,pass5)
> All I really wanted to do is to rip an "E"CD (enhanced CD) that I own,
> using abcde. I found out that cdparanoia chokes on the ECD, so I'm trying
> to figure out how to make abcde work with cdda2wav, but it apparently isn't
> at all easy. (Any hints or advice welcomed.)
>
> Oh! And by the way, this causes a segfault and a core dump:
>
> cdda2wav -D /dev/acd0 -B
>
> I'll have to send in a PR on that, I guess, but it is rather stunning to me
> that nobody even tested for that.
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