4 files changed, 96 insertions, 0 deletions

diff --git a/net/netlabel/netlabel_cipso_v4.c b/net/netlabel/netlabel_cipso_v4.c
index 24b660f16ce3..c060e3f991f1 100644
--- a/net/netlabel/netlabel_cipso_v4.c
+++ b/net/netlabel/netlabel_cipso_v4.c
@@ -41,6 +41,7 @@
 
 #include "netlabel_user.h"
 #include "netlabel_cipso_v4.h"
+#include "netlabel_mgmt.h"
 
 /* Argument struct for cipso_v4_doi_walk() */
 struct netlbl_cipsov4_doiwalk_arg {
@@ -419,6 +420,8 @@ static int netlbl_cipsov4_add(struct sk_buff *skb, struct genl_info *info)
                 ret_val = netlbl_cipsov4_add_pass(info);
                 break;
         }
+        if (ret_val == 0)
+                netlbl_mgmt_protocount_inc();
 
         audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_ADD,
                                               &audit_info);
@@ -694,6 +697,8 @@ static int netlbl_cipsov4_remove(struct sk_buff *skb, struct genl_info *info)
         ret_val = cipso_v4_doi_remove(doi,
                                       &audit_info,
                                       netlbl_cipsov4_doi_free);
+        if (ret_val == 0)
+                netlbl_mgmt_protocount_dec();
 
         audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_DEL,
                                               &audit_info);
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index b165712aaa70..4f50949722a9 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -38,6 +38,7 @@
 #include "netlabel_domainhash.h"
 #include "netlabel_unlabeled.h"
 #include "netlabel_user.h"
+#include "netlabel_mgmt.h"
 
 /*
  * Security Attribute Functions
@@ -245,6 +246,26 @@ int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
  */
 
 /**
+ * netlbl_enabled - Determine if the NetLabel subsystem is enabled
+ *
+ * Description:
+ * The LSM can use this function to determine if it should use NetLabel
+ * security attributes in it's enforcement mechanism.  Currently, NetLabel is
+ * considered to be enabled when it's configuration contains a valid setup for
+ * at least one labeled protocol (i.e. NetLabel can understand incoming
+ * labeled packets of at least one type); otherwise NetLabel is considered to
+ * be disabled.
+ *
+ */
+int netlbl_enabled(void)
+{
+        /* At some point we probably want to expose this mechanism to the user
+         * as well so that admins can toggle NetLabel regardless of the
+         * configuration */
+        return (netlbl_mgmt_protocount_value() > 0 ? 1 : 0);
+}
+
+/**
  * netlbl_socket_setattr - Label a socket using the correct protocol
  * @sk: the socket to label
  * @secattr: the security attributes
diff --git a/net/netlabel/netlabel_mgmt.c b/net/netlabel/netlabel_mgmt.c
index e00fc219c72b..5315dacc5222 100644
--- a/net/netlabel/netlabel_mgmt.c
+++ b/net/netlabel/netlabel_mgmt.c
@@ -42,6 +42,10 @@
 #include "netlabel_user.h"
 #include "netlabel_mgmt.h"
 
+/* NetLabel configured protocol count */
+static DEFINE_SPINLOCK(netlabel_mgmt_protocount_lock);
+static u32 netlabel_mgmt_protocount = 0;
+
 /* Argument struct for netlbl_domhsh_walk() */
 struct netlbl_domhsh_walk_arg {
         struct netlink_callback *nl_cb;
@@ -67,6 +71,67 @@ static const struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = {
 };
 
 /*
+ * NetLabel Misc Managment Functions
+ */
+
+/**
+ * netlbl_mgmt_protocount_inc - Increment the configured labeled protocol count
+ *
+ * Description:
+ * Increment the number of labeled protocol configurations in the current
+ * NetLabel configuration.  Keep track of this for use in determining if
+ * NetLabel label enforcement should be active/enabled or not in the LSM.
+ *
+ */
+void netlbl_mgmt_protocount_inc(void)
+{
+        rcu_read_lock();
+        spin_lock(&netlabel_mgmt_protocount_lock);
+        netlabel_mgmt_protocount++;
+        spin_unlock(&netlabel_mgmt_protocount_lock);
+        rcu_read_unlock();
+}
+
+/**
+ * netlbl_mgmt_protocount_dec - Decrement the configured labeled protocol count
+ *
+ * Description:
+ * Decrement the number of labeled protocol configurations in the current
+ * NetLabel configuration.  Keep track of this for use in determining if
+ * NetLabel label enforcement should be active/enabled or not in the LSM.
+ *
+ */
+void netlbl_mgmt_protocount_dec(void)
+{
+        rcu_read_lock();
+        spin_lock(&netlabel_mgmt_protocount_lock);
+        if (netlabel_mgmt_protocount > 0)
+                netlabel_mgmt_protocount--;
+        spin_unlock(&netlabel_mgmt_protocount_lock);
+        rcu_read_unlock();
+}
+
+/**
+ * netlbl_mgmt_protocount_value - Return the number of configured protocols
+ *
+ * Description:
+ * Return the number of labeled protocols in the current NetLabel
+ * configuration.  This value is useful in  determining if NetLabel label
+ * enforcement should be active/enabled or not in the LSM.
+ *
+ */
+u32 netlbl_mgmt_protocount_value(void)
+{
+        u32 val;
+
+        rcu_read_lock();
+        val = netlabel_mgmt_protocount;
+        rcu_read_unlock();
+
+        return val;
+}
+
+/*
  * NetLabel Command Handlers
  */
 
diff --git a/net/netlabel/netlabel_mgmt.h b/net/netlabel/netlabel_mgmt.h
index 3642d3bfc8eb..ccb2b3923591 100644
--- a/net/netlabel/netlabel_mgmt.h
+++ b/net/netlabel/netlabel_mgmt.h
@@ -168,4 +168,9 @@ enum {
 /* NetLabel protocol functions */
 int netlbl_mgmt_genl_init(void);
 
+/* NetLabel misc management functions */
+void netlbl_mgmt_protocount_inc(void);
+void netlbl_mgmt_protocount_dec(void);
+u32 netlbl_mgmt_protocount_value(void);
+
 #endif