#ifdef HAVE_SELINUX
#include <errno.h>
+#include <pthread.h>
#include <syslog.h>
#include <selinux/selinux.h>
#include <selinux/avc.h>
#include <selinux/av_permissions.h>
#include <selinux/flask.h>
+#include <signal.h>
#include <stdarg.h>
#endif /* HAVE_SELINUX */
/* Store an avc_entry_ref to speed AVC decisions. */
static struct avc_entry_ref aeref;
+/* Store the SID of the bus itself to use as the default. */
static security_id_t bus_sid = SECSID_WILD;
+
+/* Thread to listen for SELinux status changes via netlink. */
+static pthread_t avc_notify_thread;
+
+/* Prototypes for AVC callback functions. */
+static void log_callback (const char *fmt, ...);
+static void *avc_create_thread (void (*run) (void));
+static void avc_stop_thread (void *thread);
+static void *avc_alloc_lock (void);
+static void avc_get_lock (void *lock);
+static void avc_release_lock (void *lock);
+static void avc_free_lock (void *lock);
+
+/* AVC callback structures for use in avc_init. */
+static const struct avc_memory_callback mem_cb =
+{
+ .func_malloc = dbus_malloc,
+ .func_free = dbus_free
+};
+static const struct avc_log_callback log_cb =
+{
+ .func_log = log_callback,
+ .func_audit = NULL
+};
+static const struct avc_thread_callback thread_cb =
+{
+ .func_create_thread = avc_create_thread,
+ .func_stop_thread = avc_stop_thread
+};
+static const struct avc_lock_callback lock_cb =
+{
+ .func_alloc_lock = avc_alloc_lock,
+ .func_get_lock = avc_get_lock,
+ .func_release_lock = avc_release_lock,
+ .func_free_lock = avc_free_lock
+};
#endif /* HAVE_SELINUX */
/**
vsyslog (LOG_INFO, fmt, ap);
va_end(ap);
}
-#endif /* HAVE_SELINUX */
+/**
+ * On a policy reload we need to reparse the SELinux configuration file, since
+ * this could have changed. Send a SIGHUP to reload all configs.
+ */
+static int
+policy_reload_callback (u_int32_t event, security_id_t ssid,
+ security_id_t tsid, security_class_t tclass,
+ access_vector_t perms, access_vector_t *out_retained)
+{
+ if (event == AVC_CALLBACK_RESET)
+ return raise (SIGHUP);
+
+ return 0;
+}
+
+/**
+ * Create thread to notify the AVC of enforcing and policy reload
+ * changes via netlink.
+ *
+ * @param run the thread run function
+ * @return pointer to the thread
+ */
+static void *
+avc_create_thread (void (*run) (void))
+{
+ int rc;
+
+ rc = pthread_create (&avc_notify_thread, NULL, (void *(*) (void *)) run, NULL);
+ if (rc != 0)
+ {
+ _dbus_warn ("Failed to start AVC thread: %s\n", _dbus_strerror (rc));
+ exit (1);
+ }
+ return &avc_notify_thread;
+}
+
+/* Stop AVC netlink thread. */
+static void
+avc_stop_thread (void *thread)
+{
+ pthread_cancel (*(pthread_t *) thread);
+}
+
+/* Allocate a new AVC lock. */
+static void *
+avc_alloc_lock (void)
+{
+ pthread_mutex_t *avc_mutex;
+
+ avc_mutex = dbus_new (pthread_mutex_t, 1);
+ if (avc_mutex == NULL)
+ {
+ _dbus_warn ("Could not create mutex: %s\n", _dbus_strerror (errno));
+ exit (1);
+ }
+ pthread_mutex_init (avc_mutex, NULL);
+
+ return avc_mutex;
+}
+
+/* Acquire an AVC lock. */
+static void
+avc_get_lock (void *lock)
+{
+ pthread_mutex_lock (lock);
+}
+
+/* Release an AVC lock. */
+static void
+avc_release_lock (void *lock)
+{
+ pthread_mutex_unlock (lock);
+}
+
+/* Free an AVC lock. */
+static void
+avc_free_lock (void *lock)
+{
+ pthread_mutex_destroy (lock);
+ dbus_free (lock);
+}
+#endif /* HAVE_SELINUX */
/**
* Initialize the user space access vector cache (AVC) for D-BUS and set up
bus_selinux_init (void)
{
#ifdef HAVE_SELINUX
- struct avc_log_callback log_cb = {(void*)log_callback, NULL};
int r;
char *bus_context;
_dbus_verbose ("SELinux is enabled in this kernel.\n");
avc_entry_ref_init (&aeref);
- if (avc_init ("avc", NULL, &log_cb, NULL, NULL) < 0)
+ if (avc_init ("avc", &mem_cb, &log_cb, &thread_cb, &lock_cb) < 0)
{
_dbus_warn ("Failed to start Access Vector Cache (AVC).\n");
return FALSE;
_dbus_verbose ("Access Vector Cache (AVC) started.\n");
}
+ if (avc_add_callback (policy_reload_callback, AVC_CALLBACK_RESET,
+ NULL, NULL, 0, 0) < 0)
+ {
+ _dbus_warn ("Failed to add policy reload callback: %s\n",
+ _dbus_strerror (errno));
+ avc_destroy ();
+ return FALSE;
+ }
+
bus_context = NULL;
bus_sid = SECSID_WILD;
#endif /* HAVE_SELINUX */
}
-
/**
* Decrement SID reference count.
*
{
if (!selinux_enabled)
return TRUE;
-
+
/* Make the security check. AVC checks enforcing mode here as well. */
if (avc_has_perm (SELINUX_SID_FROM_BUS (sender_sid),
override_sid ?
}
-/* Function for freeing hash table data. These SIDs
+/**
+ * Function for freeing hash table data. These SIDs
* should no longer be referenced.
*/
static void
* constant time operation. If SELinux support is not available,
* always return NULL.
*
- * @todo This should return a const security_id_t since we don't
- * want the caller to mess with it.
- *
* @param service_table the hash table to check for service name.
* @param service_name the name of the service to look for.
* @returns the SELinux ID associated with the service
return NULL;
}
+/**
+ * Copy security ID table mapping from one table into another.
+ *
+ * @param dest the table to copy into
+ * @param override the table to copy from
+ * @returns #FALSE if out of memory
+ */
#ifdef HAVE_SELINUX
static dbus_bool_t
bus_selinux_id_table_copy_over (DBusHashTable *dest,
}
/**
+ * Get the SELinux policy root. This is used to find the D-BUS
+ * specific config file within the policy.
+ */
+const char *
+bus_selinux_get_policy_root (void)
+{
+#ifdef HAVE_SELINUX
+ return selinux_policy_root ();
+#else
+ return NULL;
+#endif /* HAVE_SELINUX */
+}
+
+/**
* For debugging: Print out the current hash table of service SIDs.
*/
void
projects / platform / upstream / dbus.git / blobdiff