diff --git a/include/openbsc/gsm_subscriber.h b/include/openbsc/gsm_subscriber.h
index 97c7665..90117d3 100644
--- a/include/openbsc/gsm_subscriber.h
+++ b/include/openbsc/gsm_subscriber.h
@@ -3,6 +3,7 @@
 
 #include <sys/types.h>
 #include "gsm_data.h"
+#include "linuxlist.h"
 
 #define GSM_IMEI_LENGTH 17
 #define GSM_IMSI_LENGTH 17
@@ -18,6 +19,10 @@
 	char name[GSM_NAME_LENGTH];
 	char extension[GSM_EXTENSION_LENGTH];
 	int authorized;
+
+	/* for internal management */ 
+	int use_count;
+	struct llist_head entry;
 };
 
 enum gsm_subscriber_field {
@@ -25,4 +30,8 @@
 	GSM_SUBSCRIBER_TMSI,
 };
 
+struct gsm_subscriber *subscr_alloc();
+struct gsm_subscriber *subscr_get(struct gsm_subscriber *subscr);
+struct gsm_subscriber *subscr_put(struct gsm_subscriber *subscr);
+
 #endif /* _GSM_SUBSCR_H */