udev support

[Nick Hudson]

On Sat, 2004-08-07 at 20:07 +0200, nestu wrote:
> Hi, Nick!
> Nick Hudson wrote:
> > I did some testing this afternoon and everything seems to be working as
> > far as udev goes.  Looks like all of my devices are created under /dev
> > correctly except for permissions.  Now I found this kind of strange
> > becuase devices like /dev/null and /dev/dsp are not accessible by a user
> > account.  Here is what the perms look like for those two:
> > 
> > bash-3.00# ls -la dsp
> > crwx------  1 root users 14, 3 Aug  7 12:29 dsp
> > 
> > bash-3.00# ls -la null
> > crwx------  1 root users 1, 3 Aug  7 07:29 null
> 
> /me wonders.... have you changed default perms for new nodes 
> to 0660 in /etc/udev/udev.conf? I have seen these node on my 
> dad's box, and they are:
> root at Sinosuke ~ # ls -lh /dev/null
> crw-rw-rw-  1 root root 1, 3 2004-08-07 19:35 /dev/null
> root at Sinosuke ~ # ls -lh /dev/dsp
> lrwxrwxrwx  1 root root 9 2004-08-07 17:35 /dev/dsp -> sound/dsp
> root at Sinosuke ~ # ls -lh /dev/sound/dsp
> crw-rw----  1 root audio 14, 3 2004-08-07 17:35 /dev/sound/dsp
> 

Ok I changed the default perms in the /etc/udev/udev.conf file from 0700
to 0660 and I rebooted.  Still a user cannot use either /dev/dsp
or /dev/null

nhudson at nhudson /dev $ cat null
cat: null: Permission denied

nhudson at nhudson /dev $ cat dsp 
cat: dsp: Permission denied

nhudson at nhudson /dev $ ls -la null 
crw-rw----  1 root nhudson 1, 3 2004-08-07 09:57 nul

nhudson at nhudson /dev $ ls -la dsp  
crw-rw----  1 root nhudson 14, 3 2004-08-07 14:57 dsp



> /dev/null has 0666 as I created it with those perms (and so 
> does the example POST_INSTALL I submitted with my first mail 
> of this thread):
> 
> root at Sinosuke ~ # mount --bind / DEV/
> root at Sinosuke ~ # ls -l DEV/dev
> drwxr-xr-x   2 root root    71 2004-08-07 13:38 ./
> drwxr-xr-x  21 root root  4096 2004-07-19 17:32 ../
> crw-------   1 root root  5, 1 2004-08-07 17:35 console
> prw-------   1 root root     0 2004-08-07 13:25 initctl|
> srw-rw-rw-   1 root root     0 2004-08-07 13:38 log=
> crw-rw-rw-   1 root root  1, 3 2004-08-06 16:41 null
> -rw-r--r--   1 root root 57344 2004-08-07 13:38 .udev.tdb
> 
> If you have had a look at udev's POST_INSTALL you should 
> understand the above. Mmmm, seems udev still creates a 
> couple of nodes on the fs and not on ramfs. Strange, I could 
> nearly swear only null and console show up if I boot from an 
> iso and mount the device. I wonder how they got here... oh 
> well, another thing to look at! ;)
> 

As far as the POST_INSTALL script I have no clude it works right or not.
All I get as output when I install udev is 

no need to create console
no need to create null

Now If I try and do by hand what you are doing in the script it will not
let me do any mknod functions for example.

root at nhudson /home/nhudson # mount --bind / UDEV_NODE_ROOT

root at nhudson /home/nhudson # test -e UDEV_NODE_ROOT/dev/console && echo
"no need to create console"                          
no need to create console
root at nhudson /home/nhudson # mknod -m 0600 UDEV_NODE_ROOT/dev/console c
5 1     
mknod: `UDEV_NODE_ROOT/dev/console': File exists

So according to that it cannot set the mknod perms on dev/console
because it already exists.  Maybe I am confused on how I am going about
testing it.

Also just noticed that I cannont sign emails with gpg due to the fact
that I dont have permission to use /dev/urandom

root at nhudson /dev # ls -la urandom 
crw-rw----  1 root users 1, 9 Aug  7 09:57 urandom

I just dont understand why I can use anything in dev even though I am
apart of the "users" group.

Nick


> > Overall things went pretty well.  I had to recompile my NVIDIA kernel
> > module with the new sysfs patch before it would work and I had to make a
> > change in my xorg.conf file for my mouse to read from a diffrent device.
> > Other than that and the perm problem all is well.  Once I can figure out
> > the perm problem I will start working on the dbus and hal modules then
> > things should get intresting.
> 
> Coolio! ;) About the default perms, florin has sent me a 
> couple of files to see some perms to ship with udev today. I 
> will have a look at those, and reach back with any news. 
> I'll have another look on  some doc on how to write udev 
> config files, and sum up something simple so we can all put 
> together some nice files, if needed. First I have to read 
> florin's files! ;) BTW, thanks to florin and Jens (aka 
> perldude) too since they have had their share of udev bugging !
> 
> > Nick
> Thanks for the testing, pal
> CU,
> Jaime ;)))