rename gsm_subscriber_connection to ran_conn

In preparation for inter-BSC and inter-MSC handover, we need to separate the
subscriber management logic from the actual RAN connections. What better time
to finally rename gsm_subscriber_connection.

* Name choice:

In 2G, this is a connection to the BSS, but even though 3GPP TS commonly talk
of "BSS-A" and "BSS-B" when explaining handover, it's not good to call it
"bss_conn": in 3G a BSS is called RNS, IIUC.

The overall term for 2G (GERAN) and 3G (UTRAN) is RAN: Radio Access Network.

* Rationale:

A subscriber in the MSC so far has only one RAN connection, but e.g. for
inter-BSC handover, a second one needs to be created to handover to. Most of
the items in the former gsm_subscriber_connection are actually related to the
RAN, with only a few MM and RTP related items. So, as a first step, just rename
it to ran_conn, to cosmetically prepare for moving the not strictly RAN related
items away later.

Also:

- Rename some functions from msc_subscr_conn_* to ran_conn_*
- Rename "Subscr_Conn" FSM instance name to "RAN_conn"
- Rename SUBSCR_CONN_* to RAN_CONN_*

Change-Id: Ic595f7a558d3553c067f77dc67543ab59659707a
diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c
index c9dffe3..516fc51 100644
--- a/src/libmsc/gsm_04_08_cc.c
+++ b/src/libmsc/gsm_04_08_cc.c
@@ -310,7 +310,7 @@
 static int setup_trig_pag_evt(unsigned int hooknum, unsigned int event,
 			      struct msgb *msg, void *_conn, void *_transt)
 {
-	struct gsm_subscriber_connection *conn = _conn;
+	struct ran_conn *conn = _conn;
 	struct gsm_trans *transt = _transt;
 	enum gsm_paging_event paging_event = event;
 
@@ -322,7 +322,7 @@
 		       vlr_subscr_msisdn_or_name(transt->vsub));
 		OSMO_ASSERT(conn);
 		/* Assign conn */
-		transt->conn = msc_subscr_conn_get(conn, MSC_CONN_USE_TRANS_CC);
+		transt->conn = ran_conn_get(conn, MSC_CONN_USE_TRANS_CC);
 		transt->paging_request = NULL;
 		/* send SETUP request to called party */
 		gsm48_cc_tx_setup(transt, &transt->cc.msg);
@@ -1755,7 +1755,7 @@
 	 * mgcp-gw expects the incoming RTP stream from the remote
 	 * end (e.g. Asterisk) is known. */
 
-	struct gsm_subscriber_connection *conn = trans->conn;
+	struct ran_conn *conn = trans->conn;
 	struct gsm_network *network = conn->network;
 
 	mncc_recv_rtp_sock(network, trans, MNCC_RTP_CREATE);
@@ -1859,7 +1859,7 @@
 {
 	int i, rc = 0;
 	struct gsm_trans *trans = NULL, *transt;
-	struct gsm_subscriber_connection *conn = NULL;
+	struct ran_conn *conn = NULL;
 	struct gsm_mncc *data = arg, rel;
 
 	DEBUGP(DMNCC, "receive message %s\n", get_mncc_name(msg_type));
@@ -2005,7 +2005,7 @@
 		}
 
 		/* Assign conn */
-		trans->conn = msc_subscr_conn_get(conn, MSC_CONN_USE_TRANS_CC);
+		trans->conn = ran_conn_get(conn, MSC_CONN_USE_TRANS_CC);
 		trans->dlci = 0x00; /* SAPI=0, not SACCH */
 		vlr_subscr_put(vsub);
 	} else {
@@ -2112,7 +2112,7 @@
 #define DATASLLEN \
 	(sizeof(datastatelist) / sizeof(struct datastate))
 
-int gsm0408_rcv_cc(struct gsm_subscriber_connection *conn, struct msgb *msg)
+int gsm0408_rcv_cc(struct ran_conn *conn, struct msgb *msg)
 {
 	struct gsm48_hdr *gh = msgb_l3(msg);
 	uint8_t msg_type = gsm48_hdr_msg_type(gh);
@@ -2160,7 +2160,7 @@
 			return -ENOMEM;
 		}
 		/* Assign transaction */
-		trans->conn = msc_subscr_conn_get(conn, MSC_CONN_USE_TRANS_CC);
+		trans->conn = ran_conn_get(conn, MSC_CONN_USE_TRANS_CC);
 		trans->dlci = OMSC_LINKID_CB(msg); /* DLCI as received from BSC */
 		cm_service_request_concludes(conn, msg);
 	}
@@ -2179,6 +2179,6 @@
 
 	rc = datastatelist[i].rout(trans, msg);
 
-	msc_subscr_conn_communicating(conn);
+	ran_conn_communicating(conn);
 	return rc;
 }