netlabel: Cleanup the Smack/NetLabel code to fix incoming TCP connections

This patch cleans up a lot of the Smack network access control code.  The
largest changes are to fix the labeling of incoming TCP connections in a
manner similar to the recent SELinux changes which use the
security_inet_conn_request() hook to label the request_sock and let the label
move to the child socket via the normal network stack mechanisms.  In addition
to the incoming TCP connection fixes this patch also removes the smk_labled
field from the socket_smack struct as the minor optimization advantage was
outweighed by the difficulty in maintaining it's proper state.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>

include/net/netlabel.h

@@ -417,6 +417,7 @@ int netlbl_conn_setattr(struct sock *sk,
 			const struct netlbl_lsm_secattr *secattr);
 int netlbl_req_setattr(struct request_sock *req,
 		       const struct netlbl_lsm_secattr *secattr);
+void netlbl_req_delattr(struct request_sock *req);
 int netlbl_skbuff_setattr(struct sk_buff *skb,
 			  u16 family,
 			  const struct netlbl_lsm_secattr *secattr);
@@ -547,6 +548,10 @@ static inline int netlbl_req_setattr(struct request_sock *req,
 {
 	return -ENOSYS;
 }
+static inline void netlbl_req_delattr(struct request_sock *req)
+{
+	return;
+}
 static inline int netlbl_skbuff_setattr(struct sk_buff *skb,
 				      u16 family,
 				      const struct netlbl_lsm_secattr *secattr)

net/netlabel/netlabel_kapi.c

@@ -860,6 +860,19 @@ int netlbl_req_setattr(struct request_sock *req,
 	return ret_val;
 }
 
+/**
+* netlbl_req_delattr - Delete all the NetLabel labels on a socket
+* @req: the socket
+*
+* Description:
+* Remove all the NetLabel labeling from @req.
+*
+*/
+void netlbl_req_delattr(struct request_sock *req)
+{
+	cipso_v4_req_delattr(req);
+}
+
 /**
  * netlbl_skbuff_setattr - Label a packet using the correct protocol
  * @skb: the packet

security/smack/smack.h

@@ -42,7 +42,6 @@ struct superblock_smack {
 struct socket_smack {
 	char		*smk_out;			/* outbound label */
 	char		*smk_in;			/* inbound label */
-	int		smk_labeled;			/* label scheme */
 	char		smk_packet[SMK_LABELLEN];	/* TCP peer label */
 };