calipso: Add a label cache.

This works in exactly the same way as the CIPSO label cache.
The idea is to allow the lsm to cache the result of a secattr
lookup so that it doesn't need to perform the lookup for
every skbuff.

It introduces two sysctl controls:
 calipso_cache_enable - enables/disables the cache.
 calipso_cache_bucket_size - sets the size of a cache bucket.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

3 files changed, 60 insertions, 5 deletions

diff --git a/net/netlabel/netlabel_calipso.c b/net/netlabel/netlabel_calipso.c
index 0d02c26..2ec93c5 100644
--- a/net/netlabel/netlabel_calipso.c
+++ b/net/netlabel/netlabel_calipso.c
@@ -700,3 +700,41 @@ int calipso_skbuff_delattr(struct sk_buff *skb)
 		ret_val = ops->skbuff_delattr(skb);
 	return ret_val;
 }
+
+/**
+ * calipso_cache_invalidate - Invalidates the current CALIPSO cache
+ *
+ * Description:
+ * Invalidates and frees any entries in the CALIPSO cache.  Returns zero on
+ * success and negative values on failure.
+ *
+ */
+void calipso_cache_invalidate(void)
+{
+	const struct netlbl_calipso_ops *ops = netlbl_calipso_ops_get();
+
+	if (ops)
+		ops->cache_invalidate();
+}
+
+/**
+ * calipso_cache_add - Add an entry to the CALIPSO cache
+ * @calipso_ptr: the CALIPSO option
+ * @secattr: the packet's security attributes
+ *
+ * Description:
+ * Add a new entry into the CALIPSO label mapping cache.
+ * Returns zero on success, negative values on failure.
+ *
+ */
+int calipso_cache_add(const unsigned char *calipso_ptr,
+		      const struct netlbl_lsm_secattr *secattr)
+
+{
+	int ret_val = -ENOMSG;
+	const struct netlbl_calipso_ops *ops = netlbl_calipso_ops_get();
+
+	if (ops)
+		ret_val = ops->cache_add(calipso_ptr, secattr);
+	return ret_val;
+}
diff --git a/net/netlabel/netlabel_calipso.h b/net/netlabel/netlabel_calipso.h
index 66ba92e..9fd291c 100644
--- a/net/netlabel/netlabel_calipso.h
+++ b/net/netlabel/netlabel_calipso.h
@@ -144,5 +144,8 @@ int calipso_skbuff_setattr(struct sk_buff *skb,
 			   const struct calipso_doi *doi_def,
 			   const struct netlbl_lsm_secattr *secattr);
 int calipso_skbuff_delattr(struct sk_buff *skb);
+void calipso_cache_invalidate(void);
+int calipso_cache_add(const unsigned char *calipso_ptr,
+		      const struct netlbl_lsm_secattr *secattr);
 
 #endif
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index a42ce3c..fbad718 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -1281,11 +1281,15 @@ void netlbl_skbuff_err(struct sk_buff *skb, u16 family, int error, int gateway)
 void netlbl_cache_invalidate(void)
 {
 	cipso_v4_cache_invalidate();
+#if IS_ENABLED(CONFIG_IPV6)
+	calipso_cache_invalidate();
+#endif /* IPv6 */
 }
 
 /**
  * netlbl_cache_add - Add an entry to a NetLabel protocol cache
  * @skb: the packet
+ * @family: the family
  * @secattr: the packet's security attributes
  *
  * Description:
@@ -1294,7 +1298,7 @@ void netlbl_cache_invalidate(void)
  * values on error.
  *
  */
-int netlbl_cache_add(const struct sk_buff *skb,
+int netlbl_cache_add(const struct sk_buff *skb, u16 family,
 		     const struct netlbl_lsm_secattr *secattr)
 {
 	unsigned char *ptr;
@@ -1302,10 +1306,20 @@ int netlbl_cache_add(const struct sk_buff *skb,
 	if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
 		return -ENOMSG;
 
-	ptr = cipso_v4_optptr(skb);
-	if (ptr)
-		return cipso_v4_cache_add(ptr, secattr);
-
+	switch (family) {
+	case AF_INET:
+		ptr = cipso_v4_optptr(skb);
+		if (ptr)
+			return cipso_v4_cache_add(ptr, secattr);
+		break;
+#if IS_ENABLED(CONFIG_IPV6)
+	case AF_INET6:
+		ptr = calipso_optptr(skb);
+		if (ptr)
+			return calipso_cache_add(ptr, secattr);
+		break;
+#endif /* IPv6 */
+	}
 	return -ENOMSG;
 }