gprs_ns2_sns: clear local and remote entries when SNS failed

The local and remote entries should be cleared on SNS Size.
Further it can be cleared when SNS failed (e.g. all NSVC become dead)
so VTY doesn't show old entries before entering SNS Size.

Related: OS#4949
Change-Id: Ie4db81acdd5f8ddf1a1f5dc7645d1144545d9c73
diff --git a/src/gb/gprs_ns2_sns.c b/src/gb/gprs_ns2_sns.c
index ceff115..e574b44 100644
--- a/src/gb/gprs_ns2_sns.c
+++ b/src/gb/gprs_ns2_sns.c
@@ -255,6 +255,19 @@
 	}
 }
 
+static void ns2_clear_ipv46_entries(struct ns2_sns_state *gss)
+{
+	TALLOC_FREE(gss->ip4_local);
+	TALLOC_FREE(gss->ip4_remote);
+	TALLOC_FREE(gss->ip6_local);
+	TALLOC_FREE(gss->ip6_remote);
+
+	gss->num_ip4_local = 0;
+	gss->num_ip4_remote = 0;
+	gss->num_ip6_local = 0;
+	gss->num_ip6_remote = 0;
+}
+
 static void ns2_vc_create_ip(struct osmo_fsm_inst *fi, struct gprs_ns2_nse *nse, const struct osmo_sockaddr *remote,
 			     uint8_t sig_weight, uint8_t data_weight)
 {
@@ -702,6 +715,8 @@
 	if (old_state != GPRS_SNS_ST_UNCONFIGURED)
 		ns2_prim_status_ind(gss->nse, NULL, 0, NS_AFF_CAUSE_SNS_FAILURE);
 
+	ns2_clear_ipv46_entries(gss);
+
 	/* no initial available */
 	if (!gss->initial)
 		return;
@@ -1349,6 +1364,7 @@
 		 * gprs_ns2_free_nsvcs() will trigger NO_NSVC, prevent this from triggering a reselection */
 		gss->reselection_running = true;
 		gprs_ns2_free_nsvcs(nse);
+		ns2_clear_ipv46_entries(gss);
 
 		/* Choose the next sns endpoint. */
 		if (llist_empty(&gss->sns_endpoints)) {