for ussd_get_ran, show current RAT

Change-Id: I81adb1785c1a46e9153a6914ef2c699e9c90b731
diff --git a/src/db_hlr.c b/src/db_hlr.c
index f797f2e..4f89916 100644
--- a/src/db_hlr.c
+++ b/src/db_hlr.c
@@ -813,7 +813,7 @@
 
 	for (i = 0; i < rat_types_len; i++) {
 		char *pos = rat_types_str + strnlen(rat_types_str, sizeof(rat_types_str));
-		int len = pos - rat_types_str;
+		int len = sizeof(rat_types_str) - (pos - rat_types_str);
 		rc = snprintf(pos, len, "%s%s", pos == rat_types_str ? "" : ",", osmo_rat_type_name(rat_types[i]));
 		if (rc > len) {
 			osmo_strlcpy(rat_types_str + sizeof(rat_types_str) - 4, "...", 4);
diff --git a/src/hlr_ussd.c b/src/hlr_ussd.c
index 9cd2bce..7861634 100644
--- a/src/hlr_ussd.c
+++ b/src/hlr_ussd.c
@@ -378,22 +378,27 @@
 			       const struct ss_request *req)
 {
 	struct hlr_subscriber subscr;
-	const char *response;
+	char response[512];
 	int rc;
-
-#define RAN_TYPE_DESC "Available RAN types: "
+	const char *rat;
 
 	rc = db_subscr_get_by_imsi(g_hlr->dbc, ss->imsi, &subscr);
 	switch (rc) {
 	case 0:
-		if (subscr.rat_types[OSMO_RAT_GERAN_A] && subscr.rat_types[OSMO_RAT_UTRAN_IU])
-			response = RAN_TYPE_DESC "GERAN-A (2G) & UTRAN-Iu (3G)";
-		else if (subscr.rat_types[OSMO_RAT_GERAN_A])
-			response = RAN_TYPE_DESC "GERAN-A (2G)";
-		else if (subscr.rat_types[OSMO_RAT_UTRAN_IU])
-			response = RAN_TYPE_DESC "UTRAN-Iu (3G)";
+		if (!*subscr.last_lu_rat_cs)
+			rat = "nothing, you don't exist";
+		else if (!strcmp(subscr.last_lu_rat_cs, "GERAN-A"))
+			rat = "2G";
+		else if (!strcmp(subscr.last_lu_rat_cs, "UTRAN-Iu"))
+			rat = "3G";
 		else
-			response = "No RAN types available";
+			rat = subscr.last_lu_rat_cs;
+
+		snprintf(response, sizeof(response),
+			 "Now on %s. Available:%s%s.",
+			 rat,
+			 subscr.rat_types[OSMO_RAT_GERAN_A]? " 2G" : "",
+			 subscr.rat_types[OSMO_RAT_UTRAN_IU]? " 3G" : "");
 
 		rc = ss_tx_to_ms_ussd_7bit(ss, true, req->invoke_id, response);
 		break;