Prepare entry/exit point for MSC -> BSC and MSC -> RNC communication.

Add msc_ifaces.[hc], a_iface.c, with a general msc_tx_dtap() to redirect to
different interfaces depending on the actual subscriber connection.

While iu_tx() is going to be functional fairly soon, the a_tx() is going to be
just a dummy for some time (see comment).

Add Iu specific fields in gsm_subscriber_connection: the UE connection pointer
and an indicator for the Integrity Protection status on Iu (to be fully
implemented in later commits).

Add lac member to gsm_subscriber_connection, to allow decoupling from
bts->location_area_code. The conn->lac will actually be set in iu.c in an
upcoming commit ("add iucs.[hc]").

Change-Id: Idf8020a30562426e8f939706bf5c2188d5a09798

1 files changed, 15 insertions, 0 deletions

diff --git a/openbsc/include/openbsc/gsm_data.h b/openbsc/include/openbsc/gsm_data.h
index 5693d72e7..c5a821f82 100644
--- a/openbsc/include/openbsc/gsm_data.h
+++ b/openbsc/include/openbsc/gsm_data.h
@@ -26,6 +26,7 @@ struct gsm_subscriber_group;
 struct bsc_subscr;
 struct vlr_instance;
 struct vlr_subscr;
+struct ue_conn_ctx;
 
 #define OBSC_LINKID_CB(__msgb)	(__msgb)->cb[3]
 
@@ -110,6 +111,12 @@ struct gsm_classmark {
 	uint8_t classmark3[14];
 };
 
+enum integrity_protection_state {
+	INTEGRITY_PROTECTION_NONE	= 0,
+	INTEGRITY_PROTECTION_IK		= 1,
+	INTEGRITY_PROTECTION_IK_CK	= 2,
+};
+
 /* active radio connection of a mobile subscriber */
 struct gsm_subscriber_connection {
 	/* global linked list of subscriber_connections */
@@ -186,6 +193,14 @@ struct gsm_subscriber_connection {
 	enum ran_type via_ran;
 
 	struct gsm_classmark classmark;
+
+	uint16_t lac;
+
+	/* which Iu-CS connection, if any. */
+	struct {
+		struct ue_conn_ctx *ue_ctx;
+		int integrity_protection;
+	} iu;
 };