XEN STE P OLICY

1. XEN STE POLICY • Basic Idea • Implementation • Improvement

2. Basic Idea • Subject • domain • Object • file, dir, device, domain • Rules • access control array

3. Basic Idea • Type • Basic type, can not be used directly • Label • Encapsulate types • Subject Label • Object Label • Rule • Only two labels share at least one common type that access can be permit

4. Implementation • policy management services(7) • domain management control hooks(2) • event channel control hooks(2) • grant table control hooks(2) • generic domain-requested decision hooks(2) • other(1)

5. Implementation • domain_create(...,ssidref) • xsm_domain_create(d,ssidref) • xsm_ops->domain_create(d,ssidref) • acm_domain_create(d,ssidref) • acm_primary_ops->domain_create() acm_primary_ops->acm_init_domain_ssid • ste_domain_create() • ste_pre_domain_create()

6. Implementation • acm_primary_ops->acm_init_domain_ssid • ste_init_domain_ssid

7. Domain ssid struct acm_binary_policy{ …. u16 primary_policy_code; …. }; struct acm_ssid_domain { struct list_head node; int datatype; ssidref_t ssidref; ssidref_t old_ssidref; void *primary_ssid; void *secondary_ssid; struct domain *subject; domid_t domainid; }; struct ste_ssid { ssidref_t ste_ssidref; struct acm_ste_cache_line \ ste_cache[ACM_TE_CACHE_SIZE]; }; struct domain { ….. void *ssid ….. };

8. Implementation-another example • __gnttab_map_grant_ref • xsm_grant_mapref(ld,rd,op->flags) • acm_grant_mapref(ld,rd,op->flags) • acm_pre_grant_map_ref(id) • acm_primary_ops->pre_grant_map_ref(id) • ste_pre_grant_map_ref • share_common_type(subj,obj)

9. Implementation-another example • GET_SSIDP() • have_common_type(ref_s,ref_o); dom1 dom2 domx

10. Improvement • Add Time Limit • Dynamic change rules • To be continue......

11. Thank You!