Re: policy for PowerDNS

[Daniel J Walsh <dwalsh@redhat.com>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 12/04/2012 06:37 AM, Sander Hoentjen wrote:
> On 12/03/2012 04:08 PM, grift wrote:
>> On Mon, 2012-12-03 at 15:22 +0100, Sander Hoentjen wrote:
>>> Hi all,
>>> 
>>> I had created a policy for PowerDNS (pdns package in Fedora), but
>>> after e-mailing with dwalsh he told me it might be better to just adapt
>>> the named policy a bit. Here is what I have so far: 
>>> ======pdns.fc====== /usr/sbin/pdns_server  --
>>> gen_context(system_u:object_r:named_exec_t,s0) /etc/pdns/pdns.conf
>>> -- gen_context(system_u:object_r:named_conf_t,s0) 
>>> /var/run/pdns.controlsocket -s 
>>> gen_context(system_u:object_r:named_var_run_t,s0) /var/run/pdns.pid
>>> -- gen_context(system_u:object_r:named_var_run_t,s0) 
>>> =================== ======pdns.te====== policy_module(pdns,0.0.1)
>>> 
>>> require{ type named_t; }
>>> 
>>> #gmysql backend: bool pdns_can_connect_db true; 
>>> tunable_policy(`pdns_backend_mysql', ` mysql_read_config(named_t) 
>>> #socket mysql_stream_connect(named_t) ') =================== With this
>>> added pdns works with both the bind-backend and the mysql-backend
>>> (pdns-backend-mysql in Fedora). I do still get some denials, first 2
>>> with both backends: type=AVC msg=audit(12/03/2012 14:30:26.767:597) :
>>> avc:  denied  { fsetid } for  pid=23063 comm=pdns_server
>>> capability=fsetid scontext=system_u:system_r:named_t:s0 
>>> tcontext=system_u:system_r:named_t:s0 tclass=capability
>>> 
>>> type=AVC msg=audit(12/03/2012 14:30:26.735:595) : avc:  denied  { kill
>>> } for  pid=20597 comm=pdns_server capability=kill 
>>> scontext=system_u:system_r:named_t:s0 
>>> tcontext=system_u:system_r:named_t:s0 tclass=capability
>>> 
>>> For this I can add: allow named_t self:capability { fsetid kill }; but
>>> I am not sure if that is okay, can anyone please advise?
>>> 
>>> Last one I get with the mysql backend: type=AVC msg=audit(12/03/2012
>>> 13:37:52.315:545) : avc:  denied  { getattr } for  pid=20772
>>> comm=pdns_server path=/usr/share/mysql/charsets/Index.xml dev="dm-0"
>>> ino=8936 scontext=system_u:system_r:named_t:s0 
>>> tcontext=system_u:object_r:usr_t:s0 tclass=file To allow this I will
>>> have to allow read access from named_t to usr_t, would that be okay?
>> 
>> Yes, the capabilities are a pity, but it is give and take, so all 
>> considering this looks ok to me
>> 
> Ok, thank you. I was a bit surprised that named_t already had access to a
> mysql database by the way.
> 
> PowerDNS has some more backends, next I have a question about is the pipe
> backend: This backend executes a file specified in the config, that will
> echo the response to STDOUT. Should there be a seperate domain for that
> pipe command, or is it okay to allow exec to bin_t? For now I chose the
> latter, and my .te looks like this: ======pdns.te====== 
> policy_module(pdns,0.0.1)
> 
> require{ type named_t; }
> 
> allow named_t self:capability { kill fsetid };
> 
> #gmysql backend: bool pdns_backend_mysql true; 
> tunable_policy(`pdns_backend_mysql', ` mysql_read_config(named_t) 
> files_read_usr_files(named_t) #socket mysql_stream_connect(named_t) ')
> 
> bool pdns_backend_pipe false; tunable_policy(`pdns_backend_pipe', ` 
> corecmd_exec_bin(named_t) files_read_usr_files(named_t) ') 
> =================== This, together with the .fc results in a working
> powerdns for me. If there are no further objections, what would be the next
> step to get this accepted in the (Fedora?) policy?

I don't see why rading usr_files or executing a bin_t file requires a boolean,
I would just add the access.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
Comment: Using GnuPG with undefined - http://www.enigmail.net/

iEYEARECAAYFAlC+BSkACgkQrlYvE4MpobNg9gCgijAiMt49CU7e3bzjnUlRlTc8
b6gAmgJjuwAK5DA41BJYHTT8TL75A8FG
=ModI
-----END PGP SIGNATURE-----

--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
the words "unsubscribe selinux" without quotes as the message.