Re-introduce Iu/UTRAN support

Add support for UTRAN routing areas.

Change-Id: I1b1aedd2a7c358bd388aa3d8a9f3c6a0011b4889

include/osmocom/sgsn/gprs_routing_area.h

@@ -56,6 +56,12 @@ struct sgsn_ra {
 	 * For UTRAN only do a LAC/RAC <> RNC relation and don't have a specific cell relation.
 	 */
 	enum sgsn_ra_ran_type ran_type;
+	union {
+		struct {
+			/* the RNC id must be the same for a given Routing Area */
+			struct osmo_rnc_id rnc_id;
+		} utran;
+	} u;
 
 	/* GERAN/UTRAN: cells contains a list of sgsn_ra_cells which are alive */
 	struct llist_head cells_alive_list;
@@ -77,8 +83,7 @@ struct sgsn_ra_cell {
 		} geran;
 
 		struct {
-			/* TODO: unused */
-			uint16_t rncid;
+			/* the RNC id must be the same for a given Routing Area */
 			uint16_t sac;
 		} utran;
 	} u;
@@ -107,10 +112,15 @@ struct sgsn_ra_cell *sgsn_ra_geran_get_cell_by_lai(const struct osmo_location_ar
 struct sgsn_ra_cell *sgsn_ra_geran_get_cell_by_cgi(const struct osmo_cell_global_id *cgi);
 struct sgsn_ra_cell *sgsn_ra_geran_get_cell_by_ra(const struct sgsn_ra *ra, uint16_t cell_id);
 struct sgsn_ra_cell *sgsn_ra_geran_get_cell_by_gb(uint16_t nsei, uint16_t bvci);
+
+/* UTRAN */
+int sgsn_ra_utran_register(const struct osmo_routing_area_id *rai, const struct osmo_rnc_id *rnc_id);
+
 struct sgsn_ra *sgsn_ra_geran_get_ra(const struct osmo_routing_area_id *rai);
 
 /* Page the whole routing area for this mmctx */
 int sgsn_ra_geran_page_ra(const struct osmo_routing_area_id *rai, struct sgsn_mm_ctx *mmctx);
+struct sgsn_ra *sgsn_ra_utran_get_ra(const struct osmo_routing_area_id *rai);
 
 /*
  * return value for callbacks.
@@ -125,3 +135,6 @@ int sgsn_ra_geran_page_ra(const struct osmo_routing_area_id *rai, struct sgsn_mm
 typedef int (sgsn_ra_cb_t)(struct sgsn_ra_cell *ra_cell, void *cb_data);
 int sgsn_ra_foreach_cell(struct sgsn_ra *ra, sgsn_ra_cb_t *cb, void *cb_data);
 int sgsn_ra_foreach_cell2(struct osmo_routing_area_id *rai, sgsn_ra_cb_t *cb, void *cb_data);
+
+/* Page the whole routing area for this mmctx */
+int sgsn_ra_utran_page_ra(const struct osmo_routing_area_id *rai, const struct sgsn_mm_ctx *mmctx);

src/sgsn/gprs_ranap.c

@@ -38,6 +38,7 @@
 #include <osmocom/sgsn/gprs_ranap.h>
 #include <osmocom/sgsn/gprs_gmm_attach.h>
 #include <osmocom/sgsn/gprs_mm_state_iu_fsm.h>
+#include <osmocom/sgsn/gprs_routing_area.h>
 #include <osmocom/sgsn/gtp_ggsn.h>
 #include <osmocom/sgsn/gtp.h>
 #include <osmocom/sgsn/pdpctx.h>
@@ -202,12 +203,23 @@ static int sgsn_ranap_iu_event_mmctx(struct ranap_ue_conn_ctx *ctx, enum ranap_i
 
 int sgsn_ranap_iu_event(struct ranap_ue_conn_ctx *ctx, enum ranap_iu_event_type type, void *data)
 {
+	struct ranap_iu_event_new_area *new_area;
+
 	switch (type) {
 	case RANAP_IU_EVENT_RAB_ASSIGN:
 	case RANAP_IU_EVENT_IU_RELEASE:
 	case RANAP_IU_EVENT_LINK_INVALIDATED:
 	case RANAP_IU_EVENT_SECURITY_MODE_COMPLETE:
 		return sgsn_ranap_iu_event_mmctx(ctx, type, data);
+	case RANAP_IU_EVENT_NEW_AREA:
+		/* inform the Routing Area code about a new RA for Iu */
+		new_area = data;
+
+		/* Only interesting in Routing Area changes, but not Location Area */
+		if (new_area->cell_type != RANAP_IU_NEW_RAC)
+			return 0;
+
+		return sgsn_ra_utran_register(new_area->u.rai, new_area->rnc_id);
 	default:
 		LOGP(DRANAP, LOGL_NOTICE, "Iu: Unknown event received: type: %d\n", type);
 		return -1;

src/sgsn/gprs_routing_area.c

@@ -24,6 +24,7 @@
 #include <osmocom/core/logging.h>
 #include <osmocom/core/rate_ctr.h>
 #include <osmocom/core/utils.h>
+#include <osmocom/gsm/gsm23003.h>
 #include <osmocom/gsm/gsm48.h>
 #include <osmocom/sgsn/debug.h>
 #include <osmocom/sgsn/gprs_bssgp.h>
@@ -181,6 +182,19 @@ struct sgsn_ra_cell *sgsn_ra_geran_get_cell_by_gb(uint16_t nsei, uint16_t bvci)
 	return NULL;
 }
 
+struct sgsn_ra *sgsn_ra_utran_get_ra(const struct osmo_routing_area_id *ra_id)
+{
+	struct sgsn_ra *ra = sgsn_ra_get_ra(ra_id);
+
+	if (!ra)
+		return ra;
+
+	if (ra->ran_type == RA_TYPE_UTRAN_Iu)
+		return ra;
+
+	return NULL;
+}
+
 int sgsn_ra_foreach_cell(struct sgsn_ra *ra, sgsn_ra_cb_t *cb, void *cb_data)
 {
 	struct sgsn_ra_cell *cell, *tmp;
@@ -419,6 +433,74 @@ int sgsn_ra_geran_page_ra(const struct osmo_routing_area_id *rai, struct sgsn_mm
 	return ret;
 }
 
+#ifdef BUILD_IU
+/* Register a new UTRAN Routing Area if possible.
+ * Return 0 on success and < 0 on failure. */
+int sgsn_ra_utran_register(const struct osmo_routing_area_id *rai, const struct osmo_rnc_id *rnc_id)
+{
+	struct sgsn_ra *ra = sgsn_ra_get_ra(rai);
+	if (!ra) {
+		ra = sgsn_ra_alloc(rai, RA_TYPE_UTRAN_Iu);
+		if (!ra) {
+			LOGP(DRA, LOGL_ERROR, "Couldn't create new RA for %s ran type %s\n",
+			     osmo_rai_name2(rai), get_value_string(sgsn_ra_ran_type_names, ra->ran_type));
+			return -ENOMEM;
+		}
+		ra->u.utran.rnc_id = *rnc_id;
+		LOGRA(LOGL_INFO, ra, "New UTRAN RA by RNC %s\n", osmo_rnc_id_name(&ra->u.utran.rnc_id));
+		return 0;
+	}
+
+	if (ra->ran_type == RA_TYPE_GERAN_Gb) {
+		LOGRA(LOGL_ERROR, ra, "rejecting new RA of type %s, because already present RA has ran type %s\n",
+		      get_value_string(sgsn_ra_ran_type_names, RA_TYPE_UTRAN_Iu),
+		      get_value_string(sgsn_ra_ran_type_names, ra->ran_type));
+		return -ENOENT;
+	}
+
+	/* RA already known */
+	if (osmo_rnc_id_cmp(&ra->u.utran.rnc_id, rnc_id) == 0)
+		return 0;
+
+	/* RNC id changed */
+	char new_rnc_id_name[32];
+	osmo_rnc_id_name_buf(new_rnc_id_name, sizeof(new_rnc_id_name), rnc_id);
+	LOGRA(LOGL_INFO, ra, "RNC Id changed from %s to %s\n",
+		osmo_rnc_id_name(&ra->u.utran.rnc_id), new_rnc_id_name);
+
+	ra->u.utran.rnc_id = *rnc_id;
+	return 0;
+}
+
+int sgsn_ra_utran_page_ra(const struct osmo_routing_area_id *ra_id, const struct sgsn_mm_ctx *mmctx)
+{
+	struct sgsn_ra *ra;
+	rate_ctr_inc(rate_ctr_group_get_ctr(mmctx->ctrg, GMM_CTR_PAGING_PS));
+
+	ra = sgsn_ra_utran_get_ra(ra_id);
+	if (!ra)
+		return -ENOENT;
+
+	/* Try to page by TMSI if possible */
+	if (mmctx->p_tmsi != GSM_RESERVED_TMSI)
+		return ranap_iu_page_ps2(mmctx->imsi, &mmctx->p_tmsi, ra_id);
+	if (mmctx->p_tmsi_old != GSM_RESERVED_TMSI)
+		return ranap_iu_page_ps2(mmctx->imsi, &mmctx->p_tmsi_old, ra_id);
+
+	/* Page by IMSI */
+	return ranap_iu_page_ps2(mmctx->imsi, NULL, ra_id);
+}
+#else
+int sgsn_ra_utran_page_ra(const struct osmo_routing_area_id *ra_id, const struct sgsn_mm_ctx *mmctx)
+{
+	return -1;
+}
+int sgsn_ra_utran_register(const struct osmo_routing_area_id *rai, const struct osmo_rnc_id *rnc_id)
+{
+	return -1;
+}
+#endif /* BUILD_IU */
+
 void sgsn_ra_init(struct sgsn_instance *inst)
 {
 	inst->routing_area = talloc_zero(inst, struct sgsn_ra_global);

tests/gprs_routing_area/gprs_routing_area_test.c

@@ -24,6 +24,7 @@
 #include <osmocom/core/rate_ctr.h>
 #include <osmocom/core/utils.h>
 #include <osmocom/gsm/apn.h>
+#include <osmocom/gsm/gsm23003.h>
 #include <osmocom/gsm/gsm_utils.h>
 #include <osmocom/gsm/gsup.h>
 #include <osmocom/gprs/gprs_bssgp.h>
@@ -537,6 +538,98 @@ void test_routing_area_geran_geran_bvci_change(void)
 	cleanup_test();
 }
 
+/* check if UTRAN RA gets rejected, if a GERAN RA/cell with the same LAC is already registered
+ * The SGSN does not support the same LAC/RA for GERAN and UTRAN at the same time.
+ */
+void test_routing_area_mv_utran_geran_reject(void)
+{
+	int rc;
+
+	/* GERAN */
+	struct osmo_routing_area_id geran_rai = {
+		.lac = {
+			.plmn = { .mcc = 262, .mnc = 42, .mnc_3_digits = false },
+			.lac = 24
+		},
+		.rac = 43
+	};
+	struct osmo_cell_global_id_ps cgi_ps = {
+		.rai = geran_rai,
+		.cell_identity = 9998,
+	};
+	uint16_t nsei = 2, bvci = 3;
+
+	/* UTRAN */
+	struct osmo_routing_area_id utran_rai = {
+		.lac = {
+			.plmn = { .mcc = 262, .mnc = 42, .mnc_3_digits = false },
+			.lac = 24
+		},
+		.rac = 43
+	};
+	struct osmo_rnc_id rnc_id = {
+		.plmn = utran_rai.lac.plmn,
+		.rnc_id = 2222
+	};
+
+	sgsn = sgsn_instance_alloc(tall_sgsn_ctx);
+
+	/* Registering UTRAN RA */
+	rc = sgsn_ra_utran_register(&utran_rai, &rnc_id);
+	OSMO_ASSERT(rc == 0);
+
+	/* Registering GERAN RA/cell via BVC Reset Ind (should fail) */
+	rc = sgsn_ra_geran_bvc_cell_reset_ind(nsei, bvci, &cgi_ps);
+	OSMO_ASSERT(rc != 0);
+
+	cleanup_test();
+}
+
+/* check if a UTRAN RA with the same LAC as an already register GERAN RA gets rejected */
+void test_routing_area_mv_geran_utran_reject(void)
+{
+	int rc;
+
+	/* GERAN */
+	struct osmo_routing_area_id geran_rai = {
+		.lac = {
+			.plmn = { .mcc = 262, .mnc = 42, .mnc_3_digits = false },
+			.lac = 24
+		},
+		.rac = 43
+	};
+	struct osmo_cell_global_id_ps cgi_ps = {
+		.rai = geran_rai,
+		.cell_identity = 9998,
+	};
+	uint16_t nsei = 2, bvci = 3;
+
+	/* UTRAN */
+	struct osmo_routing_area_id utran_rai = {
+		.lac = {
+			.plmn = { .mcc = 262, .mnc = 42, .mnc_3_digits = false },
+			.lac = 24
+		},
+		.rac = 43
+	};
+	struct osmo_rnc_id rnc_id = {
+		.plmn = utran_rai.lac.plmn,
+		.rnc_id = 2222
+	};
+
+	sgsn = sgsn_instance_alloc(tall_sgsn_ctx);
+
+	/* Registering GERAN RA/cell via BVC Reset Ind */
+	rc = sgsn_ra_geran_bvc_cell_reset_ind(nsei, bvci, &cgi_ps);
+	OSMO_ASSERT(rc == 0);
+
+	/* Registering UTRAN RA (should fail) */
+	rc = sgsn_ra_utran_register(&utran_rai, &rnc_id);
+	OSMO_ASSERT(rc != 0);
+
+	cleanup_test();
+}
+
 static struct log_info_cat gprs_categories[] = {
 	[DMM] = {
 		.name = "DMM",
@@ -601,6 +694,10 @@ int main(int argc, char **argv)
 	test_routing_area_paging();
 	test_routing_area_geran_geran_sig_reset();
 	test_routing_area_geran_geran_bvci_change();
+#ifdef BUILD_IU
+	test_routing_area_mv_geran_utran_reject();
+	test_routing_area_mv_utran_geran_reject();
+#endif
 	printf("Done\n");
 
 	talloc_report_full(osmo_sgsn_ctx, stderr);