6 files changed, 131 insertions, 35 deletions

diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 9b7d6f2ac9a3..ffbc7f28335a 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -144,10 +144,9 @@ struct netlbl_lsm_secattr {
 };
 
 /*
- * LSM security attribute operations
+ * LSM security attribute operations (inline)
  */
 
-
 /**
  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
  * @flags: the memory allocation flags
@@ -283,6 +282,9 @@ static inline void netlbl_secattr_free(struct netlbl_lsm_secattr *secattr)
 }
 
 #ifdef CONFIG_NETLABEL
+/*
+ * LSM security attribute operations
+ */
 int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
                                u32 offset);
 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
@@ -294,6 +296,25 @@ int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
                                  u32 start,
                                  u32 end,
                                  gfp_t flags);
+
+/*
+ * LSM protocol operations
+ */
+int netlbl_enabled(void);
+int netlbl_sock_setattr(struct sock *sk,
+                        const struct netlbl_lsm_secattr *secattr);
+int netlbl_sock_getattr(struct sock *sk,
+                        struct netlbl_lsm_secattr *secattr);
+int netlbl_skbuff_getattr(const struct sk_buff *skb,
+                          struct netlbl_lsm_secattr *secattr);
+void netlbl_skbuff_err(struct sk_buff *skb, int error);
+
+/*
+ * LSM label mapping cache operations
+ */
+void netlbl_cache_invalidate(void);
+int netlbl_cache_add(const struct sk_buff *skb,
+                     const struct netlbl_lsm_secattr *secattr);
 #else
 static inline int netlbl_secattr_catmap_walk(
                                       struct netlbl_lsm_secattr_catmap *catmap,
@@ -301,14 +322,12 @@ static inline int netlbl_secattr_catmap_walk(
 {
         return -ENOENT;
 }
-
 static inline int netlbl_secattr_catmap_walk_rng(
                                       struct netlbl_lsm_secattr_catmap *catmap,
                                       u32 offset)
 {
         return -ENOENT;
 }
-
 static inline int netlbl_secattr_catmap_setbit(
                                       struct netlbl_lsm_secattr_catmap *catmap,
                                       u32 bit,
@@ -316,7 +335,6 @@ static inline int netlbl_secattr_catmap_setbit(
 {
         return 0;
 }
-
 static inline int netlbl_secattr_catmap_setrng(
                                       struct netlbl_lsm_secattr_catmap *catmap,
                                       u32 start,
@@ -325,59 +343,33 @@ static inline int netlbl_secattr_catmap_setrng(
 {
         return 0;
 }
-#endif
-
-/*
- * LSM protocol operations
- */
-
-#ifdef CONFIG_NETLABEL
-int netlbl_sock_setattr(struct sock *sk,
-                        const struct netlbl_lsm_secattr *secattr);
-int netlbl_sock_getattr(struct sock *sk,
-                        struct netlbl_lsm_secattr *secattr);
-int netlbl_skbuff_getattr(const struct sk_buff *skb,
-                          struct netlbl_lsm_secattr *secattr);
-void netlbl_skbuff_err(struct sk_buff *skb, int error);
-#else
+static inline int netlbl_enabled(void)
+{
+        return 0;
+}
 static inline int netlbl_sock_setattr(struct sock *sk,
                                      const struct netlbl_lsm_secattr *secattr)
 {
         return -ENOSYS;
 }
-
 static inline int netlbl_sock_getattr(struct sock *sk,
                                       struct netlbl_lsm_secattr *secattr)
 {
         return -ENOSYS;
 }
-
 static inline int netlbl_skbuff_getattr(const struct sk_buff *skb,
                                         struct netlbl_lsm_secattr *secattr)
 {
         return -ENOSYS;
 }
-
 static inline void netlbl_skbuff_err(struct sk_buff *skb, int error)
 {
         return;
 }
-#endif /* CONFIG_NETLABEL */
-
-/*
- * LSM label mapping cache operations
- */
-
-#ifdef CONFIG_NETLABEL
-void netlbl_cache_invalidate(void);
-int netlbl_cache_add(const struct sk_buff *skb,
-                     const struct netlbl_lsm_secattr *secattr);
-#else
 static inline void netlbl_cache_invalidate(void)
 {
         return;
 }
-
 static inline int netlbl_cache_add(const struct sk_buff *skb,
                                    const struct netlbl_lsm_secattr *secattr)
 {
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
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index e64eca246f1a..ed9155b29c1a 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -155,6 +155,11 @@ int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid)
         int rc;
         struct netlbl_lsm_secattr secattr;
 
+        if (!netlbl_enabled()) {
+                *sid = SECSID_NULL;
+                return 0;
+        }
+
         netlbl_secattr_init(&secattr);
         rc = netlbl_skbuff_getattr(skb, &secattr);
         if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
@@ -298,6 +303,9 @@ int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
         u32 netlbl_sid;
         u32 recv_perm;
 
+        if (!netlbl_enabled())
+                return 0;
+
         rc = selinux_netlbl_skbuff_getsid(skb,
                                           SECINITSID_UNLABELED,
                                           &netlbl_sid);