flask: implement xsm_set_system_active

This commit implements full support for starting the idle domain privileged by
introducing a new flask label xenboot_t which the idle domain is labeled with
at creation.  It then provides the implementation for the XSM hook
xsm_set_system_active to relabel the idle domain to the existing xen_t flask
label.

In the reference flask policy a new macro, xen_build_domain(target), is
introduced for creating policies for dom0less/hyperlaunch allowing the
hypervisor to create and assign the necessary resources for domain
construction.

Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Tested-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Rahul Singh <rahul.singh@arm.com>
Tested-by: Rahul Singh <rahul.singh@arm.com>

diff --git a/tools/flask/policy/modules/xen.if b/tools/flask/policy/modules/xen.if
index 5e2aa472b6417e27c5613d2ce1d32635ee34b8d5..424daab6a02298c01b3ce94ae46ce64e1ab146be 100644 (file)
--- a/tools/flask/policy/modules/xen.if
+++ b/tools/flask/policy/modules/xen.if
@@ -62,6 +62,13 @@ define(`create_domain_common', `
                        setparam altp2mhvm altp2mhvm_op dm };
 ')
 
+# xen_build_domain(target)
+#   Allow a domain to be created at boot by the hypervisor
+define(`xen_build_domain', `
+       allow xenboot_t $1:domain create;
+       allow xenboot_t $1_channel:event create;
+')
+
 # create_domain(priv, target)
 #   Allow a domain to be created directly
 define(`create_domain', `

diff --git a/tools/flask/policy/modules/xen.te b/tools/flask/policy/modules/xen.te
index 3dbf93d2b859be5ab8a0ce25f4b14135895fe2b2..de98206fdd89104264eb45e94b6656799da67ed7 100644 (file)
--- a/tools/flask/policy/modules/xen.te
+++ b/tools/flask/policy/modules/xen.te
@@ -24,6 +24,7 @@ attribute mls_priv;
 ################################################################################
 
 # The hypervisor itself
+type xenboot_t, xen_type, mls_priv;
 type xen_t, xen_type, mls_priv;
 
 # Domain 0

diff --git a/tools/flask/policy/policy/initial_sids b/tools/flask/policy/policy/initial_sids
index 6b7b7eff2175d238bc218debe2052c7cb103a324..ec729d3ba3f533026d221a24c85bb4c88a101b03 100644 (file)
--- a/tools/flask/policy/policy/initial_sids
+++ b/tools/flask/policy/policy/initial_sids
@@ -2,6 +2,7 @@
 # objects created before the policy is loaded or for objects that do not have a
 # label defined in some other manner.
 
+sid xenboot gen_context(system_u:system_r:xenboot_t,s0)
 sid xen gen_context(system_u:system_r:xen_t,s0)
 sid dom0 gen_context(system_u:system_r:dom0_t,s0)
 sid domxen gen_context(system_u:system_r:domxen_t,s0)

diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
index c97c44f8039cba338d128dc4c33cd96a08d6808a..8c9cd0f2972d88e5488cb4fd99cfb39b1539a51d 100644 (file)
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -173,7 +173,7 @@ static int cf_check flask_domain_alloc_security(struct domain *d)
     switch ( d->domain_id )
     {
     case DOMID_IDLE:
-        dsec->sid = SECINITSID_XEN;
+        dsec->sid = SECINITSID_XENBOOT;
         break;
     case DOMID_XEN:
         dsec->sid = SECINITSID_DOMXEN;
@@ -193,9 +193,14 @@ static int cf_check flask_domain_alloc_security(struct domain *d)
 
 static int cf_check flask_set_system_active(void)
 {
+    struct domain_security_struct *dsec;
     struct domain *d = current->domain;
 
+    dsec = d->ssid;
+
     ASSERT(d->is_privileged);
+    ASSERT(dsec->sid == SECINITSID_XENBOOT);
+    ASSERT(dsec->self_sid == SECINITSID_XENBOOT);
 
     if ( d->domain_id != DOMID_IDLE )
     {
@@ -210,6 +215,8 @@ static int cf_check flask_set_system_active(void)
      */
     d->is_privileged = false;
 
+    dsec->self_sid = dsec->sid = SECINITSID_XEN;
+
     return 0;
 }
 

diff --git a/xen/xsm/flask/policy/initial_sids b/xen/xsm/flask/policy/initial_sids
index 7eca70d33935d156ffb98dc1908dec656f6e42df..e8b55b836860c603fd82ab65860a5668ec534812 100644 (file)
--- a/xen/xsm/flask/policy/initial_sids
+++ b/xen/xsm/flask/policy/initial_sids
@@ -3,6 +3,7 @@
 #
 # Define initial security identifiers 
 #
+sid xenboot
 sid xen
 sid dom0
 sid domio