[sane-devel] PIXMA MP530: Unprivileged user can't see
iSerialNumber, thus can't get proper device name.
m. allan noah
kitno455 at gmail.com
Wed Jan 31 21:13:46 CET 2007
On 1/31/07, m. allan noah <kitno455 at gmail.com> wrote:
> as non-root, `strace lsusb` and see what file it is opening. might not
> be in /proc
oh- and something i have seen before, is there any other software on the machine
that might have the usb device open? like printing software?
allan
> On 1/31/07, Karen Pease <meme at daughtersoftiresias.org> wrote:
> > Thanks for the response. As mentioned in the original post, all
> > of /proc/bus/usb is wide open. All of the files in that directory have the
> > same permissions. Specifically, the scanner (002/007) is:
> >
> > -rwxrwxrwx 1 root users 103 Jan 30 02:09 002/007
> >
> > Also, the directories are world-accessible:
> >
> > drwxrwxrwx 2 root root 0 Jan 29 23:45 002/
> >
> > and:
> >
> > drwxrwxrwx 4 root root 0 Jan 29 23:45 usb/
> >
> > If it's a permissions issue, it's not one that relates to /proc/bus/usb file
> > permissions, as far as I can tell.
> >
> > - Karen
> >
> > On Wednesday 31 January 2007 05:50 pm, m. allan noah wrote:
> > > what are the perms on the actual /proc/bus/usb/XXX/YYY file?
> > >
> > > allan
> > >
> > > On 1/30/07, Karen Pease <meme at daughtersoftiresias.org> wrote:
> > > > Is it possible to have non-root users scan from the MP530? I've been
> > > > spinning my gears just to get the scanner to work at all as root, and
> > > > finally managed to only by installing the CVS version of the backend and
> > > > fiddling around with it. However, I can't seem to get a common user to
> > > > have access to the scanner.
> > > >
> > > > First, what root sees. Lets just do a test.
> > > >
> > > > [root at daughtersoftiresias sane-backends]# scanimage -L
> > > > [sanei_debug] Setting debug level of pixma to 10.
> > > > [pixma] pixma version 0.12.2
> > > > device `v4l:/dev/video0' is a Noname BT848 video ( *** UNKNOWN/GENER
> > > > virtual device
> > > > device `pixma:04A91712_114A42' is a CANON Canon PIXMA MP530
> > > > multi-function peripheral
> > > > [root at daughtersoftiresias sane-backends]# scanimage -d
> > > > pixma:04A91712_114A42 -n
> > > > [sanei_debug] Setting debug level of pixma to 10.
> > > > [pixma] pixma version 0.12.2
> > > > [pixma] pixma_open(): Canon PIXMA MP530
> > > > [pixma] pixma_close(): Canon PIXMA MP530
> > > > [root at daughtersoftiresias sane-backends]#
> > > >
> > > > Success. Now, for a mere mortal (with the same SANE-related
> > > > debug/experimental environmental variables):
> > > >
> > > > [meme at daughtersoftiresias ~]$ scanimage -L
> > > > [sanei_debug] Setting debug level of pixma to 10.
> > > > [pixma] pixma version 0.12.2
> > > > device `v4l:/dev/video0' is a Noname BT848 video ( *** UNKNOWN/GENER
> > > > virtual device
> > > > device `pixma:04A91712' is a CANON Canon PIXMA MP530 multi-function
> > > > peripheral [meme at daughtersoftiresias ~]$ scanimage -d pixma:04A91712 -n
> > > > [sanei_debug] Setting debug level of pixma to 10.
> > > > [pixma] pixma version 0.12.2
> > > > [pixma] pixma_open(): Canon PIXMA MP530
> > > > [pixma] pixma_connect() failed EACCES
> > > > [pixma] pixma_open() failed EACCES
> > > > [pixma] pixma_close(): Canon PIXMA MP530
> > > > scanimage: open of device pixma:04A91712 failed: Access to resource has
> > > > been denied
> > > > [meme at daughtersoftiresias ~]$ scanimage -d pixma:04A91712_114A42 -n
> > > > [sanei_debug] Setting debug level of pixma to 10.
> > > > [pixma] pixma version 0.12.2
> > > > scanimage: open of device pixma:04A91712_114A42 failed: Invalid argument
> > > > [meme at daughtersoftiresias ~]$
> > > >
> > > > The first thing to notice is that the regular user doesn't see the same
> > > > device name as root from scanimage -L: they see a name that's missing the
> > > > serial, thus an improperly formatted pixma device name, as far as I can
> > > > tell. When I give that device, we get an "access denied", even though
> > > > I've set my /proc/bus/usb wide open. When I try the proper name that
> > > > root is given (but meme is not), I get an invalid argument -- the same as
> > > > I'd get if I typed -d pixma:qwijibo or -d pixma:ThisIsNotAValidDevice.
> > > >
> > > > So, why does it omit the serial? Well, I think I've got that one figured
> > > > out. From sane-find-scanner -v -v: First, as root:
> > > >
> > > > trying libusb:
> > > >
> > > > <device descriptor of 0x04a9/0x1712 at 002:007 (Canon MP530)>
> > > > bLength 18
> > > > bDescriptorType 1
> > > > bcdUSB 2.00
> > > > bDeviceClass 0
> > > > bDeviceSubClass 0
> > > > bDeviceProtocol 0
> > > > bMaxPacketSize0 64
> > > > idVendor 0x04A9
> > > > idProduct 0x1712
> > > > bcdDevice 1.05
> > > > iManufacturer 1 (Canon)
> > > > iProduct 2 (MP530)
> > > > iSerialNumber 3 (114A42)
> > > > bNumConfigurations 1
> > > > <configuration 0>
> > > > ...
> > > >
> > > > Now, as meme:
> > > >
> > > > trying libusb:
> > > >
> > > > <device descriptor of 0x04a9/0x1712 at 002:007>
> > > > bLength 18
> > > > bDescriptorType 1
> > > > bcdUSB 2.00
> > > > bDeviceClass 0
> > > > bDeviceSubClass 0
> > > > bDeviceProtocol 0
> > > > bMaxPacketSize0 64
> > > > idVendor 0x04A9
> > > > idProduct 0x1712
> > > > bcdDevice 1.05
> > > > iManufacturer 1 ((null))
> > > > iProduct 2 ((null))
> > > > iSerialNumber 3 ((null))
> > > > bNumConfigurations 1
> > > > <configuration 0>
> > > >
> > > > Meme seems unable to get iSerialNumber -- but it can get idVendor and
> > > > idProduct, and thus ultimately determine what kind of scanner we're
> > > > dealing with. The same thing happens with lsusb -v; root can see the
> > > > serial number, while meme can't.
> > > >
> > > > Does this look like what's causing the problem to you? Can you think of
> > > > a way to work around it? My ultimate goal is to be able to have users
> > > > just start up gimp and be able to scan, but as it stands, that's not an
> > > > option. Which is a shame, because I specifically picked the MP530
> > > > because all of its features were reported as working well in Linux.
> > > >
> > > > Thanks!
> > > >
> > > > - Karen
> > > >
> > > >
> > > > --
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> > > "The truth is an offense, but not a sin"
> >
> >
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>
>
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> "The truth is an offense, but not a sin"
>
--
"The truth is an offense, but not a sin"
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