Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6:
SELinux: use SECINITSID_NETMSG instead of SECINITSID_UNLABELED for NetLabel
SELinux: enable dynamic activation/deactivation of NetLabel/SELinux enforcement

include/net/netlabel.h

···
 };
 
 /*
- * LSM security attribute operations
+ * LSM security attribute operations (inline)
  */
-
 
 /**
  * netlbl_secattr_cache_alloc - Allocate and initialize a secattr cache
···
 }
 
 #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,
···
 				 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,
···
 {
 	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,
···
 {
 	return 0;
 }
-
 static inline int netlbl_secattr_catmap_setrng(
 	                              struct netlbl_lsm_secattr_catmap *catmap,
 				      u32 start,
···
 {
 	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)
 {

net/netlabel/netlabel_cipso_v4.c

···
 
 #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 {
···
 		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);
···
 	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);

net/netlabel/netlabel_kapi.c

···
 #include "netlabel_domainhash.h"
 #include "netlabel_unlabeled.h"
 #include "netlabel_user.h"
+#include "netlabel_mgmt.h"
 
 /*
  * Security Attribute Functions
···
 /*
  * LSM Functions
  */
+
+/**
+ * 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

net/netlabel/netlabel_mgmt.c

···
 #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;
···
 	[NLBL_MGMT_A_VERSION] = { .type = NLA_U32 },
 	[NLBL_MGMT_A_CV4DOI] = { .type = NLA_U32 },
 };
+
+/*
+ * 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

net/netlabel/netlabel_mgmt.h

···
 /* 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

security/selinux/hooks.c

···
 /**
  * selinux_skb_extlbl_sid - Determine the external label of a packet
  * @skb: the packet
- * @base_sid: the SELinux SID to use as a context for MLS only external labels
  * @sid: the packet's SID
  *
  * Description:
  * Check the various different forms of external packet labeling and determine
- * the external SID for the packet.
+ * the external SID for the packet.  If only one form of external labeling is
+ * present then it is used, if both labeled IPsec and NetLabel labels are
+ * present then the SELinux type information is taken from the labeled IPsec
+ * SA and the MLS sensitivity label information is taken from the NetLabel
+ * security attributes.  This bit of "magic" is done in the call to
+ * selinux_netlbl_skbuff_getsid().
  *
  */
-static void selinux_skb_extlbl_sid(struct sk_buff *skb,
-				   u32 base_sid,
-				   u32 *sid)
+static void selinux_skb_extlbl_sid(struct sk_buff *skb, u32 *sid)
 {
 	u32 xfrm_sid;
 	u32 nlbl_sid;
···
 	selinux_skb_xfrm_sid(skb, &xfrm_sid);
 	if (selinux_netlbl_skbuff_getsid(skb,
 					 (xfrm_sid == SECSID_NULL ?
-					  base_sid : xfrm_sid),
+					  SECINITSID_NETMSG : xfrm_sid),
 					 &nlbl_sid) != 0)
 		nlbl_sid = SECSID_NULL;
-
 	*sid = (nlbl_sid == SECSID_NULL ? xfrm_sid : nlbl_sid);
 }
 
···
 	if (sock && sock->sk->sk_family == PF_UNIX)
 		selinux_get_inode_sid(SOCK_INODE(sock), &peer_secid);
 	else if (skb)
-		selinux_skb_extlbl_sid(skb, SECINITSID_UNLABELED, &peer_secid);
+		selinux_skb_extlbl_sid(skb, &peer_secid);
 
 	if (peer_secid == SECSID_NULL)
 		err = -EINVAL;
···
 	u32 newsid;
 	u32 peersid;
 
-	selinux_skb_extlbl_sid(skb, SECINITSID_UNLABELED, &peersid);
+	selinux_skb_extlbl_sid(skb, &peersid);
 	if (peersid == SECSID_NULL) {
 		req->secid = sksec->sid;
 		req->peer_secid = SECSID_NULL;
···
 {
 	struct sk_security_struct *sksec = sk->sk_security;
 
-	selinux_skb_extlbl_sid(skb, SECINITSID_UNLABELED, &sksec->peer_sid);
+	selinux_skb_extlbl_sid(skb, &sksec->peer_sid);
 }
 
 static void selinux_req_classify_flow(const struct request_sock *req,

security/selinux/netlabel.c

···
 	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)
-		rc = security_netlbl_secattr_to_sid(&secattr,
-						    base_sid,
-						    sid);
+		rc = security_netlbl_secattr_to_sid(&secattr, base_sid, sid);
 	else
 		*sid = SECSID_NULL;
 	netlbl_secattr_destroy(&secattr);
···
 	if (netlbl_sock_getattr(sk, &secattr) == 0 &&
 	    secattr.flags != NETLBL_SECATTR_NONE &&
 	    security_netlbl_secattr_to_sid(&secattr,
-					   SECINITSID_UNLABELED,
+					   SECINITSID_NETMSG,
 					   &nlbl_peer_sid) == 0)
 		sksec->peer_sid = nlbl_peer_sid;
 	netlbl_secattr_destroy(&secattr);
···
 				struct avc_audit_data *ad)
 {
 	int rc;
-	u32 netlbl_sid;
-	u32 recv_perm;
+	u32 nlbl_sid;
+	u32 perm;
+	struct netlbl_lsm_secattr secattr;
 
-	rc = selinux_netlbl_skbuff_getsid(skb,
-					  SECINITSID_UNLABELED,
-					  &netlbl_sid);
+	if (!netlbl_enabled())
+		return 0;
+
+	netlbl_secattr_init(&secattr);
+	rc = netlbl_skbuff_getattr(skb, &secattr);
+	if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
+		rc = security_netlbl_secattr_to_sid(&secattr,
+						    SECINITSID_NETMSG,
+						    &nlbl_sid);
+	else
+		nlbl_sid = SECINITSID_UNLABELED;
+	netlbl_secattr_destroy(&secattr);
 	if (rc != 0)
 		return rc;
 
-	if (netlbl_sid == SECSID_NULL)
-		return 0;
-
 	switch (sksec->sclass) {
 	case SECCLASS_UDP_SOCKET:
-		recv_perm = UDP_SOCKET__RECVFROM;
+		perm = UDP_SOCKET__RECVFROM;
 		break;
 	case SECCLASS_TCP_SOCKET:
-		recv_perm = TCP_SOCKET__RECVFROM;
+		perm = TCP_SOCKET__RECVFROM;
 		break;
 	default:
-		recv_perm = RAWIP_SOCKET__RECVFROM;
+		perm = RAWIP_SOCKET__RECVFROM;
 	}
 
-	rc = avc_has_perm(sksec->sid,
-			  netlbl_sid,
-			  sksec->sclass,
-			  recv_perm,
-			  ad);
+	rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
 	if (rc == 0)
 		return 0;
 
-	netlbl_skbuff_err(skb, rc);
+	if (nlbl_sid != SECINITSID_UNLABELED)
+		netlbl_skbuff_err(skb, rc);
 	return rc;
 }