Hi, James I have a question just for interest. The security context stores like /etc/selinux/targeted/contexts/files/file_contexts. But you are storeing the domain security label on libvirt specific XML. Of course, this is good for libvirt POV. Is it permitted for SELinux policy POV? By the way, I want to see the further discussion of the Requirements.
Requirements not yet addressed include:
Thanks Atsushi SAKAI James Morris <jmorris@namei.org> wrote: [snip]
The domain security label configuration format is as follows:
# virsh dumpxml sys1 <domain> .... <seclabel model='selinux'> <label>system_u:system_r:virtd_t:s0</label> <policytype>targeted</policytype> </seclabel> </domain>
It's possible to query the security label of a running domain via virsh:
# virsh dominfo sys1 Id: 1 Name: sys1 UUID: fa3c8e06-0877-2a08-06fd-f2479b7bacb4 OS Type: hvm State: running CPU(s): 1 CPU time: 11.4s Max memory: 524288 kB Used memory: 524288 kB Autostart: disable Security label: system_u:system_r:virtd_t:s0 (selinux/targeted/enforcing)
The security label is deterimed via the new virDomainGetSecLabel() API method, which is transported over RPC to the backend driver (qemu in this case), and is entirely independent of the local security model, if any. e.g. this command could be run remotely from an entirely different platform: you just see what's happening on the remote system, as with other attributes of the domain.
Feedback on the design thus far is sought before proceeding to more comprehensive integration.
In particular, I'd be interested in any thoughts on the placement of the security labeling driver within libvirt, as this seems to be the most critical architectural issue (I've already refactored this aspect once).
Currently, the idea is to attach the security labeling driver to the virt driver, rather than implement it independently as a top-level component as in the case of other types of drivers (e.g. storage). This is because process-based security labeling is highly dependent on the kind of virtualization in use, and may not make sense at all in some cases (e.g. when using a non-Linux hypervisor, or containers).
In the case of qemu, a security labeling driver is added to qemud:
@@ -63,6 +64,7 @@ struct qemud_driver { char *vncListen;
virCapsPtr caps; + virSecLabelDriverPtr secLabelDriver; };
and then initialized during qemud startup from qemudSecLabelInit().
During initialization, any available security labeling drivers are probed, and the first one which thinks it should be used is installed. Top-level libvirt API calls are then dispatched to the active security labeling driver via the backend virt driver, as necessary.
Note that the security labeling framework in this release is always built-in -- it can be made a compile-time option later if desired.
Requirements not yet addressed include: - Labeling of resources and generally comprehensive labeling management - Automatic labeling (e.g. for the simple isolation use-case) - Integration of labeling support into higher-level management tools such as virt-manager - Integration with the audit subsystem to help with administration and debugging - Domain of interpretation (DOI) checking/translation - Python bindings
As mentioned, the goal at this stage is to get feedback on the underlying design: comments welcome!
- James -- James Morris <jmorris@namei.org>