[MLSXFRM]: Define new SELinux service routine

This defines a routine that combines the Type Enforcement portion of
one sid with the MLS portion from the other sid to arrive at a new
sid. This would be used to define a sid for a security association
that is to be negotiated by IKE as well as for determing the sid for
open requests and connection-oriented child sockets.

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index 063af47..911954a 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -78,6 +78,8 @@
 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
                                  u16 tclass);
 
+int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid);
+
 #define SECURITY_FS_USE_XATTR		1 /* use xattr */
 #define SECURITY_FS_USE_TRANS		2 /* use transition SIDs, e.g. devpts/tmpfs */
 #define SECURITY_FS_USE_TASK		3 /* use task SIDs, e.g. pipefs/sockfs */