Remove redundancy in LAC processing

Always use LAC which is part of Cell Global ID otherwise we might end up
in a situation where separately stored LAC differs.

Both are described in 3GPP TS 23.008 $2.4 as temporary subscriber data
to be stored in VLR. Both are defined in 3GPP TS 23.003. The LAC is part
of LAI which is part of CGI so there should be no case when those values
differ for a given subscriber.

Change-Id: I993ebc3e14f25e83124b6d3f8461a4b18f971f8e

8 files changed, 9 insertions, 11 deletions

diff --git a/include/osmocom/msc/vlr.h b/include/osmocom/msc/vlr.h
index 2f31063a6..20a9c0f24 100644
--- a/include/osmocom/msc/vlr.h
+++ b/include/osmocom/msc/vlr.h
@@ -142,9 +142,7 @@ struct vlr_subscr {
 	/* Newly allocated TMSI that was not yet acked by MS */
 	uint32_t tmsi_new;
 
-	/* some redundancy in information below? */
 	struct osmo_cell_global_id cgi;			/* 2.4.16 */
-	uint16_t lac;					/* 2.4.2 */
 
 	char imeisv[GSM23003_IMEISV_NUM_DIGITS+1];	/* 2.2.3 */
 	char imei[GSM23003_IMEISV_NUM_DIGITS+1];	/* 2.1.9 */
diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c
index 5500f6f28..5567da9d0 100644
--- a/src/libmsc/gsm_04_08_cc.c
+++ b/src/libmsc/gsm_04_08_cc.c
@@ -1939,7 +1939,7 @@ int mncc_tx_to_cc(struct gsm_network *net, int msg_type, void *arg)
 						GSM48_CC_CAUSE_UNASSIGNED_NR);
 		}
 		/* If subscriber is not "attached" */
-		if (!vsub->lac) {
+		if (!vsub->cgi.lai.lac) {
 			DEBUGP(DCC, "(bts - trx - ts - ti -- sub %s) "
 				"Received '%s' from MNCC with "
 				"detached subscriber %s\n", data->called.number,
@@ -1978,7 +1978,7 @@ int mncc_tx_to_cc(struct gsm_network *net, int msg_type, void *arg)
 					"unallocated channel, paging already "
 					"started for lac %d.\n",
 					data->called.number,
-					get_mncc_name(msg_type), vsub->lac);
+					get_mncc_name(msg_type), vsub->cgi.lai.lac);
 				vlr_subscr_put(vsub);
 				trans_free(trans);
 				return 0;
diff --git a/src/libmsc/gsm_09_11.c b/src/libmsc/gsm_09_11.c
index 43bf48c56..3ee6e9247 100644
--- a/src/libmsc/gsm_09_11.c
+++ b/src/libmsc/gsm_09_11.c
@@ -287,7 +287,7 @@ static struct gsm_trans *establish_nc_ss_trans(struct gsm_network *net,
 	}
 
 	/* If subscriber is not "attached" */
-	if (!vsub->lac) {
+	if (!vsub->cgi.lai.lac) {
 		LOGP(DMM, LOGL_ERROR, "Network-originated session "
 			"rejected - subscriber is not attached\n");
 		return NULL;
diff --git a/src/libmsc/gsm_subscriber.c b/src/libmsc/gsm_subscriber.c
index 188807e92..0e76efc11 100644
--- a/src/libmsc/gsm_subscriber.c
+++ b/src/libmsc/gsm_subscriber.c
@@ -116,12 +116,12 @@ static int msc_paging_request(struct vlr_subscr *vsub)
 	 * SCCP connections (if any). */
 	switch (vsub->cs.attached_via_ran) {
 	case RAN_GERAN_A:
-		return a_iface_tx_paging(vsub->imsi, vsub->tmsi, vsub->lac);
+		return a_iface_tx_paging(vsub->imsi, vsub->tmsi, vsub->cgi.lai.lac);
 	case RAN_UTRAN_IU:
 		return ranap_iu_page_cs(vsub->imsi,
 					vsub->tmsi == GSM_RESERVED_TMSI?
 					NULL : &vsub->tmsi,
-					vsub->lac);
+					vsub->cgi.lai.lac);
 	default:
 		break;
 	}
diff --git a/src/libmsc/msc_vty.c b/src/libmsc/msc_vty.c
index 5622c024c..3079bc3a0 100644
--- a/src/libmsc/msc_vty.c
+++ b/src/libmsc/msc_vty.c
@@ -631,7 +631,7 @@ static void subscr_dump_full_vty(struct vty *vty, struct vlr_subscr *vsub)
 		vty_out(vty, "    Extension: %s%s", vsub->msisdn,
 			VTY_NEWLINE);
 	vty_out(vty, "    LAC: %d/0x%x%s",
-		vsub->lac, vsub->lac, VTY_NEWLINE);
+		vsub->cgi.lai.lac, vsub->cgi.lai.lac, VTY_NEWLINE);
 	vty_out(vty, "    RAN: %s%s",
 		ran_type_name(vsub->cs.attached_via_ran), VTY_NEWLINE);
 	vty_out(vty, "    IMSI: %s%s", vsub->imsi, VTY_NEWLINE);
diff --git a/src/libvlr/vlr_lu_fsm.c b/src/libvlr/vlr_lu_fsm.c
index 5d171d5ed..e635305fa 100644
--- a/src/libvlr/vlr_lu_fsm.c
+++ b/src/libvlr/vlr_lu_fsm.c
@@ -950,7 +950,7 @@ static int assoc_lfp_with_sub(struct osmo_fsm_inst *fi, struct vlr_subscr *vsub)
 	vsub->lu_fsm = fi;
 	vsub->msc_conn_ref = lfp->msc_conn_ref;
 	/* FIXME: send new LAC to HLR? */
-	vsub->lac = lfp->new_lai.lac;
+	vsub->cgi.lai.lac = lfp->new_lai.lac;
 	lfp->vsub = vsub;
 	/* Tell MSC to associate this subscriber with the given
 	 * connection */
diff --git a/tests/msc_vlr/msc_vlr_test_call.c b/tests/msc_vlr/msc_vlr_test_call.c
index 4a4f2436a..b1ff2c0f3 100644
--- a/tests/msc_vlr/msc_vlr_test_call.c
+++ b/tests/msc_vlr/msc_vlr_test_call.c
@@ -154,7 +154,7 @@ static void standard_lu()
 	vsub = vlr_subscr_find_by_imsi(net->vlr, IMSI);
 	VERBOSE_ASSERT(vsub != NULL, == true, "%d");
 	VERBOSE_ASSERT(strcmp(vsub->imsi, IMSI), == 0, "%d");
-	VAL_ASSERT("LAC", vsub->lac, == 23, "%u");
+	VAL_ASSERT("LAC", vsub->cgi.lai.lac, == 23, "%u");
 	vlr_subscr_put(vsub);
 }
 
diff --git a/tests/msc_vlr/msc_vlr_test_ss.c b/tests/msc_vlr/msc_vlr_test_ss.c
index 4e8077eb7..832293c52 100644
--- a/tests/msc_vlr/msc_vlr_test_ss.c
+++ b/tests/msc_vlr/msc_vlr_test_ss.c
@@ -68,7 +68,7 @@ static void perform_lu(void)
 	vsub = vlr_subscr_find_by_imsi(net->vlr, IMSI);
 	VERBOSE_ASSERT(vsub != NULL, == true, "%d");
 	VERBOSE_ASSERT(strcmp(vsub->imsi, IMSI), == 0, "%d");
-	VAL_ASSERT("LAC", vsub->lac, == 23, "%u");
+	VAL_ASSERT("LAC", vsub->cgi.lai.lac, == 23, "%u");
 	vlr_subscr_put(vsub);
 
 	bss_sends_clear_complete();