Nut upsdev - Jan 2008 - "upsdrvctl shutdown" ignores "-u"

Hi again,

it seems to me that "upsdrvctl shutdown" fails to pass the
"-u" flag to
the driver.  See drivers/upsdrvctl.c:shutdown_driver(), and compare to
start_driver() in the same file. This has been so since ancient
history (I checked back to 1.5.0), so there must be a reason, but I
can't think of any. 

I have a good reason for passing "-u root": at the time the shutdown
script reaches power-off, most file systems, including the USB
filesystem, have been unmounted. One must remount the USB filesystem
to access the UPS. But at that point, hotplugging can't be relied
upon, and therefore I would like to run the driver as root.

The reason I didn't notice this problem before is that I always called
the driver directly, rather than upsdrvctl. But that would not be the
case in a standard installation.

Moreover, this problem is hard to debug without reading the source
code, because -DD prints out a made-up command line, rather than the
one actually used.

Any objections to fixing this?

-- Peter

> it seems to me that "upsdrvctl shutdown" fails to pass the
"-u" flag to
> the driver.  See drivers/upsdrvctl.c:shutdown_driver(), and compare to
> start_driver() in the same file. This has been so since ancient
> history (I checked back to 1.5.0), so there must be a reason, but I
> can't think of any.
I think the reason if fairly trivial, we never thought this would be needed.
> I have a good reason for passing "-u root": at the time the
shutdown
> script reaches power-off, most file systems, including the USB
> filesystem, have been unmounted. One must remount the USB filesystem
> to access the UPS. But at that point, hotplugging can't be relied
> upon, and therefore I would like to run the driver as root.
You have every reason to do so and I want to take this even further. I
don't think it is a good idea to drop privileges at all when running the
shutdown command. So rather than appending '-u root', I would suggest to
make dropping privileges in the main driver body depending on the command
sent to the driver. If we're shutting down anyway, dropping privileges is
probably a waste of effort and might even be counter productive (as you
made very clear).
> The reason I didn't notice this problem before is that I always called
> the driver directly, rather than upsdrvctl. But that would not be the
> case in a standard installation.
>
> Moreover, this problem is hard to debug without reading the source
> code, because -DD prints out a made-up command line, rather than the
> one actually used.
>
> Any objections to fixing this?
Not at all. Thanks for the tip!

Best regards, Arjen
-- 
Eindhoven - The Netherlands
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