[TAG] pppd changing file permissions (Was Re: lpr works for user not root in Basiclinux 2.1)

[sindi keesan]

On Tue, 27 Mar 2007, Ben Okopnik wrote:

> On Tue, Mar 27, 2007 at 11:54:51PM +0000, sindi keesan wrote:
>>
>> ttyp0 also changed permissions after I rebooted on the other computer.
>> It is still okay here (as root root).  It is needed by rxvt. Xvesa appears
>> to be staying suid root.
>
> "/dev/ttypX" files are pseudoterminal slave devices; their permissions,
> etc. change all the time. No surprises there. I suggest you read up on
> them in /usr/src/linux/Documentation/devices.txt (although I suspect
> that you don't have the kernel sources installed - which would give the
> constantly-repeated point that you're using a Broken-As-Designed distro
> yet another turn at the sharpening bench.) Perhaps you can get a copy
> from someone with a less-broken system; it's only about 100k, and
> contains a huge amount of info about the files in /dev.

I installed kernel source a long time ago and compiled lots of kernels, 
some of them not broken ;=)  I am using a custom 2.4.31 kernel.  I also 
have the Slackware 7.1 (and later) CDs.

> Also, do note that terminal emulators such as 'xterm' and 'rxvt' are
> usually SUID root. At least one of the reasons for this (at least in my
> opinion) is the ability to "adjust" device files despite possible
> weirdness in ownership/permissions.

rxvt is SUID root on this computer.  Maybe I need to make it that on the 
computer where user cannot use rxvt unless I keep resetting permissions. 
(They are 40 min apart, by foot, and it is raining).

pppd is -rwsr-xr-- root users
Should it be -rws--x--x root root like rxvt?

I have the strace man page and have succeeded in disabling one vt by 
filling the screen (probably with 4K of data, which started repeating 
things about SEEK_SET and start and len and ioctl). I don't understand man 
pages and will ask Karolis for help with strace.

Sindi

>
> -- 
> * Ben Okopnik * Editor-in-Chief, Linux Gazette * http://LinuxGazette.NET *
>

keesan at sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org