flask/policy: sort dom0 accesses

For the example policy shipped with Xen, it makes sense to allow dom0
access to all system calls so that policy does not need to be updated
for each new hypervisor or toolstack feature used.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>

tools/flask/policy/policy/modules/xen/xen.te

@@ -51,20 +51,58 @@ type device_t, resource_type;
 
 ################################################################################
 #
-# Rules required to boot the hypervisor and dom0
+# Allow dom0 access to all sysctls, devices, and the security server.
+#
+# While this could be written more briefly using wildcards, the permissions are
+# listed out to make removing specific permissions simpler.
 #
 ################################################################################
-allow dom0_t xen_t:xen { kexec readapic writeapic mtrr_read mtrr_add mtrr_del
-	physinfo heap quirk readconsole writeconsole settime getcpuinfo
-	microcode cpupool_op pm_op tmem_control getscheduler setscheduler };
-allow dom0_t xen_t:mmu { memorymap };
-allow dom0_t security_t:security { check_context compute_av compute_create
-	compute_member load_policy compute_relabel compute_user setenforce
-	setbool setsecparam add_ocontext del_ocontext };
+allow dom0_t xen_t:xen {
+	settime tbufcontrol readconsole clearconsole perfcontrol mtrr_add
+	mtrr_del mtrr_read microcode physinfo quirk writeconsole readapic
+	writeapic privprofile nonprivprofile kexec firmware sleep frequency
+	getidle debug getcpuinfo heap pm_op mca_op lockprof cpupool_op tmem_op
+	tmem_control getscheduler setscheduler
+};
+allow dom0_t xen_t:mmu memorymap;
 
-allow dom0_t dom0_t:domain { getdomaininfo getvcpuinfo getvcpuaffinity };
+# Allow dom0 to use these domctls on itself. For domctls acting on other
+# domains, see the definitions of create_domain and manage_domain.
+allow dom0_t dom0_t:domain {
+	setvcpucontext max_vcpus setvcpuaffinity getvcpuaffinity getscheduler
+	getdomaininfo getvcpuinfo getvcpucontext setdomainmaxmem setdomainhandle
+	setdebugging hypercall settime setaddrsize getaddrsize trigger
+	getextvcpucontext setextvcpucontext getvcpuextstate setvcpuextstate
+	getpodtarget setpodtarget set_misc_info set_virq_handler
+};
+allow dom0_t dom0_t:domain2 {
+	set_cpuid gettsc settsc setscheduler
+};
 allow dom0_t dom0_t:resource { add remove };
 
+# These permissions allow using the FLASK security server to compute access
+# checks locally, which could be used by a domain or service (such as xenstore)
+# that does not have its own security server to make access decisions based on
+# Xen's security policy.
+allow dom0_t security_t:security {
+	compute_av compute_create compute_member compute_relabel compute_user
+};
+
+# Allow string/SID conversions (for "xl list -Z" and similar)
+allow dom0_t security_t:security check_context;
+
+# Allow flask-label-pci to add and change labels
+allow dom0_t security_t:security { add_ocontext del_ocontext };
+
+# Allow performance parameters of the security server to be tweaked
+allow dom0_t security_t:security setsecparam;
+
+# Allow changing the security policy
+allow dom0_t security_t:security { load_policy setenforce setbool };
+
+# Audit policy change events even when they are allowed
+auditallow dom0_t security_t:security { load_policy setenforce setbool };
+
 admin_device(dom0_t, device_t)
 admin_device(dom0_t, irq_t)
 admin_device(dom0_t, ioport_t)
@@ -72,8 +110,6 @@ admin_device(dom0_t, iomem_t)
 
 domain_comms(dom0_t, dom0_t)
 
-auditallow dom0_t security_t:security { load_policy setenforce setbool };
-
 # Allow all domains to use (unprivileged parts of) the tmem hypercall
 allow domain_type xen_t:xen tmem_op;