=item B<setenforce> I<1|0|Enforcing|Permissive>
Enable or disable enforcing of the FLASK access controls. The default is
-permissive and can be changed using the flask_enforcing option on the
-hypervisor's command line.
+permissive, but this can be changed to enforcing by specifying "flask=enforcing"
+or "flask=late" on the hypervisor's command line.
=item B<loadpolicy> I<policy-file>
Note that specifying zero as domU value means zero, while for dom0 it means
to use the default.
-### flask\_enabled
-> `= <integer>`
-
-### flask\_enforcing
-> `= <integer>`
+### flask
+> `= permissive | enforcing | late | disabled`
+
+> Default: `permissive`
+
+Specify how the FLASK security server should be configured. This option is only
+available if the hypervisor was compiled with XSM support (which can be enabled
+by setting XSM\_ENABLE = y in .config).
+
+* `permissive`: This is intended for development and is not suitable for use
+ with untrusted guests. If a policy is provided by the bootloader, it will be
+ loaded; errors will be reported to the ring buffer but will not prevent
+ booting. The policy can be changed to enforcing mode using "xl setenforce".
+* `enforcing`: This requires a security policy to be provided by the bootloader
+ and will enter enforcing mode prior to the creation of domain 0. If a valid
+ policy is not provided, the hypervisor will not continue booting.
+* `late`: This disables loading of the security policy from the bootloader.
+ FLASK will be enabled but will not enforce access controls until a policy is
+ loaded by a domain using "xl loadpolicy". Once a policy is loaded, FLASK will
+ run in enforcing mode unless "xl setenforce" has changed that setting.
+* `disabled`: This causes the XSM framework to revert to the dummy module. The
+ dummy module provides the same security policy as is used when compiling the
+ hypervisor without support for XSM. The xsm\_op hypercall can also be used to
+ switch to this mode after boot, but there is no way to re-enable FLASK once
+ the dummy module is loaded.
### font
> `= <height>` where height is `8x8 | 8x14 | 8x16`
When running in permissive mode, only the first denial of a given
source/destination is printed to the log, so labeling devices using this method
may require multiple passes to find all required ranges.
-
-Additional notes on XSM:FLASK
------------------------------
-
-1) xen command line parameters
-
- a) flask_enforcing
-
- The default value for flask_enforcing is '0'. This parameter causes the
- platform to boot in permissive mode which means that the policy is loaded
- but not enforced. This mode is often helpful for developing new systems
- and policies as the policy violations are reported on the xen console and
- may be viewed in dom0 through 'xl dmesg'.
-
- To boot the platform into enforcing mode, which means that the policy is
- loaded and enforced, append 'flask_enforcing=1' on the grub line.
-
- This parameter may also be changed through the flask hypercall.
-
- b) flask_enabled
-
- The default value for flask_enabled is '1'. This parameter causes the
- platform to enable the FLASK security module under the XSM framework.
- The parameter may be enabled/disabled only once per boot. If the parameter
- is set to '0', only a reboot can re-enable flask. When flask_enabled is '0'
- the DUMMY module is enforced.
-
- This parameter may also be changed through the flask hypercall. But may
- only be performed once per boot.
#define _copy_to_guest copy_to_guest
#define _copy_from_guest copy_from_guest
-int flask_enforcing = 0;
-integer_param("flask_enforcing", flask_enforcing);
+enum flask_bootparam_t __read_mostly flask_bootparam = FLASK_BOOTPARAM_PERMISSIVE;
+static void parse_flask_param(char *s);
+custom_param("flask", parse_flask_param);
-int flask_enabled = 1;
-integer_param("flask_enabled", flask_enabled);
+bool_t __read_mostly flask_enforcing = 0;
+boolean_param("flask_enforcing", flask_enforcing);
#define MAX_POLICY_SIZE 0x4000000
extern struct xsm_operations *original_ops;
+static void __init parse_flask_param(char *s)
+{
+ if ( !strcmp(s, "enforcing") )
+ {
+ flask_enforcing = 1;
+ flask_bootparam = FLASK_BOOTPARAM_ENFORCING;
+ }
+ else if ( !strcmp(s, "late") )
+ {
+ flask_enforcing = 1;
+ flask_bootparam = FLASK_BOOTPARAM_LATELOAD;
+ }
+ else if ( !strcmp(s, "disabled") )
+ flask_bootparam = FLASK_BOOTPARAM_DISABLED;
+ else if ( !strcmp(s, "permissive") )
+ flask_bootparam = FLASK_BOOTPARAM_PERMISSIVE;
+ else
+ flask_bootparam = FLASK_BOOTPARAM_INVALID;
+}
+
static int domain_has_security(struct domain *d, u32 perms)
{
struct domain_security_struct *dsec;
{
int ret;
void *buf = NULL;
+ bool_t is_reload = ss_initialized;
ret = domain_has_security(current->domain, SECURITY__LOAD_POLICY);
if ( ret )
if ( ret )
goto out;
+ if ( !is_reload )
+ printk(XENLOG_INFO "Flask: Policy loaded, continuing in %s mode.\n",
+ flask_enforcing ? "enforcing" : "permissive");
+
xfree(bool_pending_values);
bool_pending_values = NULL;
ret = 0;
static __init void flask_init(void)
{
- int ret = 0;
+ int ret = -ENOENT;
- if ( !flask_enabled )
+ switch ( flask_bootparam )
{
- printk("Flask: Disabled at boot.\n");
+ case FLASK_BOOTPARAM_DISABLED:
+ printk(XENLOG_INFO "Flask: Disabled at boot.\n");
return;
- }
- printk("Flask: Initializing.\n");
+ case FLASK_BOOTPARAM_PERMISSIVE:
+ case FLASK_BOOTPARAM_ENFORCING:
+ case FLASK_BOOTPARAM_LATELOAD:
+ break;
+
+ case FLASK_BOOTPARAM_INVALID:
+ default:
+ panic("Flask: Invalid value for flask= boot parameter.\n");
+ }
avc_init();
if ( register_xsm(&flask_ops) )
panic("Flask: Unable to register with XSM");
- ret = security_load_policy(policy_buffer, policy_size);
+ if ( policy_size && flask_bootparam != FLASK_BOOTPARAM_LATELOAD )
+ ret = security_load_policy(policy_buffer, policy_size);
+
+ if ( ret && flask_bootparam == FLASK_BOOTPARAM_ENFORCING )
+ panic("Unable to load FLASK policy");
- if ( flask_enforcing )
- printk("Flask: Starting in enforcing mode.\n");
+ if ( ret )
+ printk(XENLOG_INFO "Flask: Access controls disabled until policy is loaded.\n");
+ else if ( flask_enforcing )
+ printk(XENLOG_INFO "Flask: Starting in enforcing mode.\n");
else
- printk("Flask: Starting in permissive mode.\n");
+ printk(XENLOG_INFO "Flask: Starting in permissive mode.\n");
}
xsm_initcall(flask_init);
#include "av_permissions.h"
#include "security.h"
-extern int flask_enforcing;
+extern bool_t flask_enforcing;
/*
* An entry in the AVC.
#define POLICYDB_VERSION_MIN POLICYDB_VERSION_BASE
#define POLICYDB_VERSION_MAX POLICYDB_VERSION_BOUNDARY
-extern int flask_enabled;
+enum flask_bootparam_t {
+ FLASK_BOOTPARAM_PERMISSIVE,
+ FLASK_BOOTPARAM_ENFORCING,
+ FLASK_BOOTPARAM_LATELOAD,
+ FLASK_BOOTPARAM_DISABLED,
+ FLASK_BOOTPARAM_INVALID,
+};
+
+extern enum flask_bootparam_t flask_bootparam;
extern int flask_mls_enabled;
int security_load_policy(void * data, size_t len);
projects / people / gdunlap / xen.git / commitdiff