Re: netlabel: UNLABELED ath9k not denying unlabeled traffic

From: Justin P. Mattock
Date: Wed Jan 14 2009 - 12:32:56 EST


Paul Moore wrote:
On Wednesday 14 January 2009 11:15:46 am Justin P. Mattock wrote:
Paul Moore wrote:
On Wednesday 14 January 2009 12:18:18 am Justin P. Mattock wrote:
When using netlabelctl on a dell laptop
I'm able to define the addresses that I want:

netlabelctl unlbl add interface:wlan0 address:<radiostation>
label:system_u:object_r:netlabel_peer_t:s0
netlabelctl unlbl add interface:wlan0 address:<myaddress>
label:system_u:object_r:netlabel_peer_t:s0
netlabelctl -p unlbl accept off

{the above was from http://paulmoore.livejournal.com/1758.html };

...

(I'm able to listen to the radio station allowed, then if I choose
another station; if I haven't defined an address like the above,
mplayer just sits there.denying the unlabeled packet. that is
until I allow the address);
The problem I have is when I do the same on my macbook pro ati
chipset. with the ath9k module, I'm able to listen to any station,
search the web etc..
it seems netlabelctl -p unlbl accept off makes no difference if
it's on or off.

Is this built into ath9k yet, or is there something I'm missing?
That is just plain odd, there isn't really anything that is driver
specific. Can you share any more details like kernel version,
netlabel_tools verion, distro, etc? I don't have any ath9k
hardware lying around to test so I would appreciate whatever
additional information you can provide.
Hey alright.(I finally got around to trying netlabelctl out!).

It's pretty cool. In newer versions of netlabelctl I added an undocumented option to actually allow it to fix a sandwhich and do the dishes afterwards. The exact command line option needed is left as an exercise for the reader :)
yep, it is pretty cool.
ultimately my goal with netlabel is to see if I can setup the network
namespace(if this is proper to say).
i.g. have all the radio stations in its own domain,(and possibly it's own tag,doi etc..)
and then have all T.V. stations running in its own domain. and then web searching in its own domain.
I see cipsov4 does this, but not sure if it does what the UNLABEL domain/protocol does.
(just looking at cipsov4; look like ipsec, you need two computers setup with the same domain and tag etc..)
not too sure though.
The two systems I have for this are: Dell latitude x200
running ubuntu jaunty, kernel is 2.6.29-rc1.
with netlabel_tools_0.18 which was an rpm packaged
that I converted to .deb.(can't remember the repository where I
grabbed it from);
The wireless card for the dell is a dell 1350
using bcmxx(b43-phy0); works great.

Great. I'm not a debian user so I can't be of much help on the packaging side, but you can get raw tarballs from the NetLabel project site on SF (the current release is 0.19 which includes support for all the goodies in 2.6.28):

* http://netlabel.sf.net
I did grab that package but ran into the version_info
error,(resorted to the rpm out of desperation);
The results when using netlabelctl with the dell is nice, i.g. like I
said as soon as I issue netlabelctl unlbl accept off, those addresses
not defined are simply not allowed.(the problem with the dell is I'm
not seeing any allow rules being generated: i.g.

allow netlabel_peer_t netif_t:netif ingress;
allow netlabel_peer_t node_t:node recvfrom;
allow unlabeled_t netif_t:netif ingress;
allow unlabeled_t node_t:node recvfrom;

[NOTE: the rules/permissions you list above are the "newer" network_peer permissions which are likely not active unless you are running a custom SELinux policy as the default Reference Policy hasn't made the switch yet to the newer system]

The netlabelctl tool doesn't generate any allow rules, all it does is configure the NetLabel subsystem which is all that is necessary because, this is important, NetLabel doesn't actually do any network traffic enforcement. NetLabel is a network labeling framework, which means that it only deals with setting labels on outbound network packets and retrieving labels from inbound network packets (the "netlabel unlbl accept on|off" option is a gray area). The decision about wether to accept or reject inbound network traffic is left to the LSM (NetLabel supports both SELinux and Smack). If you want I can go into more detail but it would probably be rather boring and not really provide you much in the way of answering your question.
boring to others, but to me, it's awesome.

The next is a macbookpro ati chipset the kernel is 2.6.29-rc1
the o.s. is ubuntu jaunty, the netlabel_tools is the same as above.
the only results I see out of this is the avc's it's generating
(the allow rules above are from the macbook);
some reason the dell doesn't generate any avc's,
which makes me wonder is this a module issue.

Huh. Just so I'm clear on this ... on the macbook you see avc denials that correspond to the allow rules you posted above, but on the dell you don't see the same avc denials? Are you running the same SELinux policy on both systems (version numbers)? What is the output of the following command on both systems?

# cat /selinux/policy_capabilities/network_peer_controls
for both systems I'm running the refpolicy(svn) from tresys.
the new ubac options, and newrole mechanism etc..
doing cat /selinux/policy_capabilities_netowork_peer_controls says "1"
should be for both.
Also I've gone through thinking, well maybe this is avc's driven,
i.g. each address once added by netlabelctl receives a certain allow
rule (like the allow rules above),
if not either no allow rule is given to it,resulting in a denial you
can't see in dmesg,
or a denial that just won't be allowed by checkpolicy.
So after seeing if this was the case I was left with an address
defined by netlabel(allowed) and defined the allow rules that it had
created. unfortunately after all of that I still was able to turn on
another radio station that had no address in netlabelctl's unlbl
database.(and no allow rule
with SELinux);
leading me to believe that the netlabel area or driver isn't working
properly. or just told to not enforce the netlabel accept off option.

Well, like I said above, it shouldn't be a policy module or allow rule problem but I think you may be right in that the SELinux policy is a good place to start looking. Compare the policy on the two systems to see if they are the same version and check to see if the new network peer controls are active (the cat command above; 0 is disabled, 1 is enabled). Post what you find out.
they should be for both(uncommenting in /etc/selinux/refpolicy/policy/policy_capabilities
enables that option);

I think at this point I'm going to load an older kernel, with the madwifi
module(ath0) to isolate this issue i.g. if ath0 module reacts the same
as the dell does(when adding address and such); then this would point
me in the right direction. but if I receive the same response.
then maybe my libraries are messed up.
As for the list, I have linux-wireless in my address book(not sure
which is right);

Not sure linux-wireless will have much to do about this but you included the SELinux which is good, thank you.

overall I like this netlabel mechanism, hopefully I can get this
working properly.

regards;

Justin P. Mattock
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