NetLabel: make netlbl_lsm_secattr struct easier/quicker to understand

The existing netlbl_lsm_secattr struct required the LSM to check all of the
fields to determine if any security attributes were present resulting in a lot
of work in the common case of no attributes.  This patch adds a 'flags' field
which is used to indicate which attributes are present in the structure; this
should allow the LSM to do a quick comparison to determine if the structure
holds any security attributes.

Example:

 if (netlbl_lsm_secattr->flags)
	/* security attributes present */
 else
	/* NO security attributes present */

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 11 insertions, 2 deletions

diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 4e223aa25e5b..d605d7954013 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -111,11 +111,17 @@ struct netlbl_lsm_cache {
 	void (*free) (const void *data);
 	void *data;
 };
+#define NETLBL_SECATTR_NONE             0x00000000
+#define NETLBL_SECATTR_DOMAIN           0x00000001
+#define NETLBL_SECATTR_CACHE            0x00000002
+#define NETLBL_SECATTR_MLS_LVL          0x00000004
+#define NETLBL_SECATTR_MLS_CAT          0x00000008
 struct netlbl_lsm_secattr {
+	u32 flags;
+
 	char *domain;
 
 	u32 mls_lvl;
-	u32 mls_lvl_vld;
 	unsigned char *mls_cat;
 	size_t mls_cat_len;
 
@@ -174,7 +180,10 @@ static inline void netlbl_secattr_cache_free(struct netlbl_lsm_cache *cache)
  */
 static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
 {
-	memset(secattr, 0, sizeof(*secattr));
+	secattr->flags = 0;
+	secattr->domain = NULL;
+	secattr->mls_cat = NULL;
+	secattr->cache = NULL;
 }
 
 /**