SELinux: peer secid consolidation for external network labeling

Now that labeled IPsec makes use of the peer_sid field in the
sk_security_struct we can remove a lot of the special cases between labeled
IPsec and NetLabel.  In addition, create a new function,
security_skb_extlbl_sid(), which we can use in several places to get the
security context of the packet's external label which allows us to further
simplify the code in a few places.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/include/selinux_netlabel.h b/security/selinux/include/selinux_netlabel.h
index 57943f4..2a732c9 100644
--- a/security/selinux/include/selinux_netlabel.h
+++ b/security/selinux/include/selinux_netlabel.h
@@ -38,14 +38,12 @@
 
 #ifdef CONFIG_NETLABEL
 void selinux_netlbl_cache_invalidate(void);
+int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid);
 int selinux_netlbl_socket_post_create(struct socket *sock);
 void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock);
-u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid);
 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
 				struct sk_buff *skb,
 				struct avc_audit_data *ad);
-u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock);
-u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb);
 void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
 				      int family);
 void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
@@ -62,6 +60,14 @@
 	return;
 }
 
+static inline int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
+					       u32 base_sid,
+					       u32 *sid)
+{
+	*sid = SECSID_NULL;
+	return 0;
+}
+
 static inline int selinux_netlbl_socket_post_create(struct socket *sock)
 {
 	return 0;
@@ -73,12 +79,6 @@
 	return;
 }
 
-static inline u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb,
-						   u32 sock_sid)
-{
-	return SECSID_NULL;
-}
-
 static inline int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
 					      struct sk_buff *skb,
 					      struct avc_audit_data *ad)
@@ -86,16 +86,6 @@
 	return 0;
 }
 
-static inline u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock)
-{
-	return SECSID_NULL;
-}
-
-static inline u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb)
-{
-	return SECSID_NULL;
-}
-
 static inline void selinux_netlbl_sk_security_reset(
 					       struct sk_security_struct *ssec,
 					       int family)