+/*
+ * using a linked list for extended_perms_decision lookup because the list is
+ * always small. i.e. less than 5, typically 1
+ */
+static struct extended_perms_decision *avc_xperms_decision_lookup(u8 driver,
+ struct avc_xperms_node *xp_node)
+{
+ struct avc_xperms_decision_node *xpd_node;
+
+ list_for_each_entry(xpd_node, &xp_node->xpd_head, xpd_list) {
+ if (xpd_node->xpd.driver == driver)
+ return &xpd_node->xpd;
+ }
+ return NULL;
+}
+
+static inline unsigned int
+avc_xperms_has_perm(struct extended_perms_decision *xpd,
+ u8 perm, u8 which)
+{
+ unsigned int rc = 0;
+
+ if ((which == XPERMS_ALLOWED) &&
+ (xpd->used & XPERMS_ALLOWED))
+ rc = security_xperm_test(xpd->allowed->p, perm);
+ else if ((which == XPERMS_AUDITALLOW) &&
+ (xpd->used & XPERMS_AUDITALLOW))
+ rc = security_xperm_test(xpd->auditallow->p, perm);
+ else if ((which == XPERMS_DONTAUDIT) &&
+ (xpd->used & XPERMS_DONTAUDIT))
+ rc = security_xperm_test(xpd->dontaudit->p, perm);
+ return rc;
+}
+
+static void avc_xperms_allow_perm(struct avc_xperms_node *xp_node,
+ u8 driver, u8 perm)
+{
+ struct extended_perms_decision *xpd;
+ security_xperm_set(xp_node->xp.drivers.p, driver);
+ xpd = avc_xperms_decision_lookup(driver, xp_node);
+ if (xpd && xpd->allowed)
+ security_xperm_set(xpd->allowed->p, perm);
+}
+
+static void avc_xperms_decision_free(struct avc_xperms_decision_node *xpd_node)
+{
+ struct extended_perms_decision *xpd;
+
+ xpd = &xpd_node->xpd;
+ if (xpd->allowed)
+ kmem_cache_free(avc_xperms_data_cachep, xpd->allowed);
+ if (xpd->auditallow)
+ kmem_cache_free(avc_xperms_data_cachep, xpd->auditallow);
+ if (xpd->dontaudit)
+ kmem_cache_free(avc_xperms_data_cachep, xpd->dontaudit);
+ kmem_cache_free(avc_xperms_decision_cachep, xpd_node);
+}
+
+static void avc_xperms_free(struct avc_xperms_node *xp_node)
+{
+ struct avc_xperms_decision_node *xpd_node, *tmp;
+
+ if (!xp_node)
+ return;
+
+ list_for_each_entry_safe(xpd_node, tmp, &xp_node->xpd_head, xpd_list) {
+ list_del(&xpd_node->xpd_list);
+ avc_xperms_decision_free(xpd_node);
+ }
+ kmem_cache_free(avc_xperms_cachep, xp_node);
+}
+
+static void avc_copy_xperms_decision(struct extended_perms_decision *dest,
+ struct extended_perms_decision *src)
+{
+ dest->driver = src->driver;
+ dest->used = src->used;
+ if (dest->used & XPERMS_ALLOWED)
+ memcpy(dest->allowed->p, src->allowed->p,
+ sizeof(src->allowed->p));
+ if (dest->used & XPERMS_AUDITALLOW)
+ memcpy(dest->auditallow->p, src->auditallow->p,
+ sizeof(src->auditallow->p));
+ if (dest->used & XPERMS_DONTAUDIT)
+ memcpy(dest->dontaudit->p, src->dontaudit->p,
+ sizeof(src->dontaudit->p));
+}
+
+/*
+ * similar to avc_copy_xperms_decision, but only copy decision
+ * information relevant to this perm
+ */
+static inline void avc_quick_copy_xperms_decision(u8 perm,
+ struct extended_perms_decision *dest,
+ struct extended_perms_decision *src)
+{
+ /*
+ * compute index of the u32 of the 256 bits (8 u32s) that contain this
+ * command permission
+ */
+ u8 i = perm >> 5;
+
+ dest->used = src->used;
+ if (dest->used & XPERMS_ALLOWED)
+ dest->allowed->p[i] = src->allowed->p[i];
+ if (dest->used & XPERMS_AUDITALLOW)
+ dest->auditallow->p[i] = src->auditallow->p[i];
+ if (dest->used & XPERMS_DONTAUDIT)
+ dest->dontaudit->p[i] = src->dontaudit->p[i];
+}
+
+static struct avc_xperms_decision_node
+ *avc_xperms_decision_alloc(u8 which)
+{
+ struct avc_xperms_decision_node *xpd_node;
+ struct extended_perms_decision *xpd;
+
+ xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep,
+ GFP_ATOMIC | __GFP_NOMEMALLOC);
+ if (!xpd_node)
+ return NULL;
+
+ xpd = &xpd_node->xpd;
+ if (which & XPERMS_ALLOWED) {
+ xpd->allowed = kmem_cache_zalloc(avc_xperms_data_cachep,
+ GFP_ATOMIC | __GFP_NOMEMALLOC);
+ if (!xpd->allowed)
+ goto error;
+ }
+ if (which & XPERMS_AUDITALLOW) {
+ xpd->auditallow = kmem_cache_zalloc(avc_xperms_data_cachep,
+ GFP_ATOMIC | __GFP_NOMEMALLOC);
+ if (!xpd->auditallow)
+ goto error;
+ }
+ if (which & XPERMS_DONTAUDIT) {
+ xpd->dontaudit = kmem_cache_zalloc(avc_xperms_data_cachep,
+ GFP_ATOMIC | __GFP_NOMEMALLOC);
+ if (!xpd->dontaudit)
+ goto error;
+ }
+ return xpd_node;
+error:
+ avc_xperms_decision_free(xpd_node);
+ return NULL;
+}
+
+static int avc_add_xperms_decision(struct avc_node *node,
+ struct extended_perms_decision *src)
+{
+ struct avc_xperms_decision_node *dest_xpd;
+
+ node->ae.xp_node->xp.len++;
+ dest_xpd = avc_xperms_decision_alloc(src->used);
+ if (!dest_xpd)
+ return -ENOMEM;
+ avc_copy_xperms_decision(&dest_xpd->xpd, src);
+ list_add(&dest_xpd->xpd_list, &node->ae.xp_node->xpd_head);
+ return 0;
+}
+
+static struct avc_xperms_node *avc_xperms_alloc(void)
+{
+ struct avc_xperms_node *xp_node;
+
+ xp_node = kmem_cache_zalloc(avc_xperms_cachep,
+ GFP_ATOMIC|__GFP_NOMEMALLOC);
+ if (!xp_node)
+ return xp_node;
+ INIT_LIST_HEAD(&xp_node->xpd_head);
+ return xp_node;
+}
+
+static int avc_xperms_populate(struct avc_node *node,
+ struct avc_xperms_node *src)
+{
+ struct avc_xperms_node *dest;
+ struct avc_xperms_decision_node *dest_xpd;
+ struct avc_xperms_decision_node *src_xpd;
+
+ if (src->xp.len == 0)
+ return 0;
+ dest = avc_xperms_alloc();
+ if (!dest)
+ return -ENOMEM;
+
+ memcpy(dest->xp.drivers.p, src->xp.drivers.p, sizeof(dest->xp.drivers.p));
+ dest->xp.len = src->xp.len;
+
+ /* for each source xpd allocate a destination xpd and copy */
+ list_for_each_entry(src_xpd, &src->xpd_head, xpd_list) {
+ dest_xpd = avc_xperms_decision_alloc(src_xpd->xpd.used);
+ if (!dest_xpd)
+ goto error;
+ avc_copy_xperms_decision(&dest_xpd->xpd, &src_xpd->xpd);
+ list_add(&dest_xpd->xpd_list, &dest->xpd_head);
+ }
+ node->ae.xp_node = dest;
+ return 0;
+error:
+ avc_xperms_free(dest);
+ return -ENOMEM;
+
+}
+
+static inline u32 avc_xperms_audit_required(u32 requested,
+ struct av_decision *avd,
+ struct extended_perms_decision *xpd,
+ u8 perm,
+ int result,
+ u32 *deniedp)
+{
+ u32 denied, audited;
+
+ denied = requested & ~avd->allowed;
+ if (unlikely(denied)) {
+ audited = denied & avd->auditdeny;
+ if (audited && xpd) {
+ if (avc_xperms_has_perm(xpd, perm, XPERMS_DONTAUDIT))
+ audited &= ~requested;
+ }
+ } else if (result) {
+ audited = denied = requested;
+ } else {
+ audited = requested & avd->auditallow;
+ if (audited && xpd) {
+ if (!avc_xperms_has_perm(xpd, perm, XPERMS_AUDITALLOW))
+ audited &= ~requested;
+ }
+ }
+
+ *deniedp = denied;
+ return audited;
+}
+
+static inline int avc_xperms_audit(u32 ssid, u32 tsid, u16 tclass,
+ u32 requested, struct av_decision *avd,
+ struct extended_perms_decision *xpd,
+ u8 perm, int result,
+ struct common_audit_data *ad)
+{
+ u32 audited, denied;
+
+ audited = avc_xperms_audit_required(
+ requested, avd, xpd, perm, result, &denied);
+ if (likely(!audited))
+ return 0;
+ return slow_avc_audit(ssid, tsid, tclass, requested,
+ audited, denied, result, ad, 0);
+}
+