netlabel: Add support for querying a CALIPSO DOI.

Query a specified DOI through the NLBL_CALIPSO_C_LIST command.
It requires the attribute:
 NLBL_CALIPSO_A_DOI.

The reply will contain:
 NLBL_CALIPSO_A_MTYPE

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 6af1bb6..0f05b83 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -223,6 +223,8 @@
  * struct netlbl_calipso_ops - NetLabel CALIPSO operations
  * @doi_add: add a CALIPSO DOI
  * @doi_free: free a CALIPSO DOI
+ * @doi_getdef: returns a reference to a DOI
+ * @doi_putdef: releases a reference of a DOI
  *
  * Description:
  * This structure is filled out by the CALIPSO engine and passed
@@ -234,6 +236,8 @@
 	int (*doi_add)(struct calipso_doi *doi_def,
 		       struct netlbl_audit *audit_info);
 	void (*doi_free)(struct calipso_doi *doi_def);
+	struct calipso_doi *(*doi_getdef)(u32 doi);
+	void (*doi_putdef)(struct calipso_doi *doi_def);
 };
 
 /*