[Goodies-dev] xfce4-sensors-plugin: hddtemp not setuid message

[Fabian Nowak]

Hey Mariano,

> > No, it looks for being executable in general but returning invalid
> >  stuff; so it comes to the conclusion that the SMARt sensor cannot be
> >  polled due to missing permissions.
> >
> 
> Oh, yes now I see which is the idea. So that was why changing that
> value worked for me. Sorry for that, my mistake.

No problem at all.

> >
> >  Anyway, did some changes in svn, you might want to check them and
> >  whether it's working better. If not, it might be nice to give me the
> >  return codes and output to stdout and stderr of running hddtemp on valid
> >  and invalid devices both with sudo/setuid root and without.
> 
> I'm running hddtemp version 0.3-beta15. I've got this outputs:
> 
> With setuid
> $ ll /usr/sbin/hddtemp ; hddtemp /dev/sda ; echo "\$? = "$?
> -rwsr-xr-x 1 root root 26716 2008-02-17 15:52 /usr/sbin/hddtemp
> /dev/sda: WDC WD1600JS-00MHB0: 56°C
> $? = 0
> 
> $ ll /usr/sbin/hddtemp ; hddtemp /dev/fd ; echo "\$? = "$?
> -rwsr-xr-x 1 root root 26716 2008-02-17 15:52 /usr/sbin/hddtemp
> ERROR: /dev/fd: can't determine bus type (or this bus type is unknown)
> $? = 1
> 
> $ ll /usr/sbin/hddtemp ; hddtemp /dev/null ; echo "\$? = "$?
> -rwsr-xr-x 1 root root 26716 2008-02-17 15:52 /usr/sbin/hddtemp
> ERROR: /dev/null: can't determine bus type (or this bus type is unknown)
> $? = 1
> 
> $ ll /usr/sbin/hddtemp ; hddtemp /dev/nodevice ; echo "\$? = "$?
> -rwsr-xr-x 1 root root 26716 2008-02-17 15:52 /usr/sbin/hddtemp
> /dev/nodevice: open: No existe el fichero o el directorio
> 
> $? = 1
> (this has the system locale output, translation: "No file or
> directory". I know this case should never happen as names are fetched
> form sys, just to be more informative)
> 
> Without setuid
> $ ll /usr/sbin/hddtemp ; hddtemp /dev/sda ; echo "\$? = "$?
> -rwxr-xr-x 1 root root 26716 2008-02-17 15:52 /usr/sbin/hddtemp
> /dev/sda: open: Permiso denegado
> 
> $? = 1
> (again the locale, translation: "Permission denied")
> 
> $ ll /usr/sbin/hddtemp ; hddtemp /dev/fd ; echo "\$? = "$?
> -rwxr-xr-x 1 root root 26716 2008-02-17 15:52 /usr/sbin/hddtemp
> ERROR: /dev/fd: can't determine bus type (or this bus type is unknown)
> $? = 1
> 
> $ ll /usr/sbin/hddtemp ; hddtemp /dev/null ; echo "\$? = "$?
> -rwxr-xr-x 1 root root 26716 2008-02-17 15:52 /usr/sbin/hddtemp
> ERROR: /dev/null: can't determine bus type (or this bus type is unknown)
> $? = 1
> 
> $ ll /usr/sbin/hddtemp ; hddtemp /dev/nodevice ; echo "\$? = "$?
> -rwxr-xr-x 1 root root 26716 2008-02-17 15:52 /usr/sbin/hddtemp
> /dev/nodevice: open: No existe el fichero o el directorio
> 
> $? = 1
> (translation: "No file or directory")

Thanks for the error codes - and your understanding of how bad it is to
be used.

> 
> Doing "grep exit *.c" on hddtemp code in
> http://download.savannah.nongnu.org/releases/hddtemp/ I've found that
> the author is using (or planning to use) these error codes: -2, -1, 1,
> 2, 3. He seems to use mostly 1. But as you had already written in some
> comments, those checks are version dependent.

:)

> The changes in svn revision 4012 look fine. Don't misunderstand me, my
> doubt was more like a theoretical one. The svn version seems to be
> working OK, but IMHO the strings comparison for devices seems a bit
> hardwired. I don't want to be pedantic, but perhaps in this case you
> may want to look at the stat function instead of access, although the
> bitwise operations make code less maintainable. This weekend I'll try
> to see if the stat solution is viable to avoid this cases.

Yeah, this night I've also been wondering why not simply checking for
setuid bit would work; but you know, there are rot users under X around
this world... (some of  them administrate our university servers...) and
again, checking the way I do just enables "understanding" or
"justifying" the return codes  from the point of view of the plugin with
regard to hddtemp's behaviour.

For getting the device names, I don't think fstat is appropriate.

Anyway, I'd really appreciate your investigations as I'm beginning to
move out of my current flat for this month and won't have plenty of
time.

> 
> Hope I haven't been too harsh, as you've seen in the locale, English
> is not my native language.

No, it's all perfect; and you don't need to translate any German,
Spanish, Italian, Portuguese, French for me, I can at least read and
assemble them ;)

> Thanks for the answers and your time. Regards,

Again, you're welcome, thanks in return, cheers

*gonnapaintaflatnow* Fabian