add lsm op for getting name of enabled lsm

src/lxc/lsm/lsm.c

@@ -62,13 +62,20 @@ void lsm_init(void)
 	INFO("Initialized LSM security driver %s", drv->name);
 }
 
-int lsm_enabled()
+int lsm_enabled(void)
 {
 	if (drv)
 		return drv->enabled();
 	return 0;
 }
 
+const char *lsm_name(void)
+{
+	if (drv)
+		return drv->name;
+	return "none";
+}
+
 char *lsm_process_label_get(pid_t pid)
 {
 	if (!drv) {

src/lxc/lsm/lsm.h

@@ -39,6 +39,7 @@ struct lsm_drv {
 #if HAVE_APPARMOR || HAVE_SELINUX
 void        lsm_init(void);
 int         lsm_enabled(void);
+const char *lsm_name(void);
 char       *lsm_process_label_get(pid_t pid);
 int         lsm_process_label_set(const char *label, int use_default);
 int         lsm_proc_mount(struct lxc_conf *lxc_conf);
@@ -46,6 +47,7 @@ void  lsm_proc_unmount(struct lxc_conf *lxc_conf);
 #else
 static inline void        lsm_init(void) { }
 static inline int         lsm_enabled(void) { return 0; }
+static inline const char *lsm_name(void) { return "none"; }
 static inline char       *lsm_process_label_get(pid_t pid) { return NULL; }
 static inline int         lsm_process_label_set(char *label, int use_default) { return 0; }
 static inline int         lsm_proc_mount(struct lxc_conf *lxc_conf) { return 0; }