Re: Fedora Core 5, Aladdin eToken PRO32 and udev hotplug

[Jan Just Keijser <janjust@nikhef.nl>]

hi all,

just for the record: I finally managed to figure out what goes wrong. 
It's a nice catch-22 :

- etoken usb stick is inserted
- udev calls etoken.hotplug script based on rule BUS="usb", 
SUBSYSTEM="usb"
- etoken.hotplug script sends a message to the etokend deamon
- the etokend daemon wants to talk to the etoken stick using the 'char' 
device /dev/bus/usb/XXX:YYY to enable the device
- however, the char device is not created until after the etoken.hotplug 
finishes ...  catch-22!

the workaround is to change the udev 'add' rule to call the 
etoken.hotplug script *after* the char device has been created by udev.  
This means that instead of matching on
  ACTION="add", BUS="usb", SUBSYSTEM="usb", \
I am now matching on
  ACTION="add", SUBSYSTEM="usb_device", \

and I can happily insert and remove the etoken stick over and over and 
over ;-)

cheers,

Jan Just Keijser
System Integrator
NIKHEF
Amsterdam

Jan Just Keijser wrote:
> hi all,
>
> I've got a weird problem with the udev-way of hotplugging things. 
> here's my setup. It's a bit long, so please bear with me ;-)
> - Fedora Core 5, kernel 2.6.20, i686
> - udev-084-13.fc5.2 (FC5 default)
> - Aladdin eToken PRO32 with CardOS 4.21 (*NOT* recognized by 
> OpenCT/OpenSC); this is a USB stick that acts as a smart card for 
> storing certificates, private keys etc etc.
> - Aladdin RTE 3.65 eToken software (binaries only).
>
> Here's what happens:
> The RTE eToken software installs a daemon, /usr/local/sbin/etokend, 
> which listens on a UNIX socket /var/tmp/.etoken
> It also installs a perl script
>  /etc/hotplug.d/usb/etoken.hotplug
> which you're suppose to call when an eToken is inserted or removed; 
> the Perl script talks to the etokend daemon using the /var/tmp/.etoken 
> UNIX socket.
> This mechanism works fine on CentOS 4 , with the older 'hotplug' 
> mechanism installed. I can plug the token in and out as many times as 
> I like, and it will be recognized every time.
>
> With FC5 and udev, things get hairier: first , I added a rule in
>  /etc/udev/rules.d/20-etoken.rules
> ---
> # add rule
> ACTION="add", BUS="usb", SUBSYSTEM="usb", \
>    SYSFS{idVendor}="0529", SYSFS{idProduct}="0600", \
>    RUN="/etc/hotplug.d/usb/etoken.hotplug"
> ---
>
> to make sure the Perl thingie is called when I plug in a token. I've 
> added debug statements to the etoken.hotplug script and can see that 
> it is actually being called when I plug in the token (not when I 
> remove it, however).
>
> First gripe: how do I add a rule to call the same script when the 
> token in unplugged? When the token is unplugged the SYSFS vars seem to 
> be gone.... so how do I create a rule that matches this usb device only?
>
> The script is called, and the very first time I insert the token, it 
> works. Yippee for udev!
> However... if I switch tokens, or take it out and put it back in a 
> couple of times, then sooner or later it will no longer be recognized.
> I did some tracing and digging and am now stuck:
> - calling the /etc/hotplug.d/usb/etoken.hotplug by hand *ALWAYS* 
> causes the thing to come up, e.g.
>  # ACTION­d DEVICE=/proc/bus/usb/001/003 
> /etc/hotplug.d/usb/etoken.hotplug
> works
> - calling the script from within the udev rules file causes it to 
> sometimes work and sometimes not.
> - if I stick 'socat' in between the hotplug script and the etokend 
> daemon I can see what data is sent to the etokend daemon. It's the 
> same from the command line as it is from within the udev framework. 
> Also, with 'socat' in the middle it seems to always work from the 
> commandline and merely sometimes from within the udev framework
> - the same script works fine on a CentOS4 box (kernel 2.6.9, 
> hotplug-2004_04_01-7.7)
>
> Of course, I'd like the eToken to be recognized by the OS without user 
> intervention...
> So the big question for me is: what's so different about how scripts 
> are called from within the udev manager vs calling them from the 
> commandline? I've checked all environment variables and tried to 
> mimick the 'udev' env var set as much as possible on the command line 
> (e.g. no PATH, MANPATH, LANG, LC_ALL etc etc) but on the command-line, 
> the script always works...
>


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