Check write permissions in parent directory for file delete

[Fernando RUIZ CASAS]

On Mon, 10 Nov 2003 11:36:09 +0500, Sergey Ablalimov wrote:

> 
> Hello.
> 
> I am using IMFS as a base file system. And I do following operations:
> ---------------------------------------------------------------
> RTEMS SHELL (Ver.1.0-FRC):/dev/console. Nov  9 2003. 'help' to list commands.
> shel [/etc] $ whoami
> ant
> shel [/] $ ls
> drwxr-xr-x   1   root   root        5092 Jan 01 00:00 dev/
> drwxrwxrwx   1   root   root        3484 Nov 02 22:28 disc/
> drwxr-xr-x   1   root   root        1340 Nov 02 22:28 etc/
> 3 files 9916 bytes occupied
> shel [/] $ cd etc
> shel [/etc] $ ls
> -rw-r--r--   1   root   root          90 Nov 02 22:28 passwd 
> -rw-r--r--   1   root   root         117 Nov 02 22:28 shadow 
> -rw-r--r--   1   root   root          42 Nov 02 22:28 group 
> -rw-r--r--   1   root   root          34 Nov 02 22:28 issue 
> -rw-r--r--   1   root   root          28 Nov 02 22:28 issue.net 
> 5 files 311 bytes occupied
> shel [/etc] $ rm issue
> shel [/etc] $ ls
> -rw-r--r--   1   root   root          90 Nov 02 22:28 passwd 
> -rw-r--r--   1   root   root         117 Nov 02 22:28 shadow 
> -rw-r--r--   1   root   root          42 Nov 02 22:29 group 
> -rw-r--r--   1   root   root          28 Nov 02 22:28 issue.net 
> 4 files 277 bytes occupied
> shel [/etc] $ 
> --------------------------------------------------------------------
> I'm not root. I don't have permissions for write in /etc directory, but
> I can delete files from /etc.
> I see in file "cpukit/libcsupport/src/unlink.c". There are no support 
> for check write permissions in parent directory.
> Is this RTEMS error?
>
Hi,
 Certainly the rtems imfs implementation is not completly verified at this level because the shell
is an contribution and not a kernel part. 
 At the beginning Rtems is thunk as a root system but not as an user system. All your verification
can be added at the libcsupport library. 
 AT shell level the unlink call is transparent at the user. The system is the guardian of the
security level. 

BRGDS; (FRC)
 
> -- 
>  Sergey                          mailto:sa at design.morion.ru
> 
> 
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