SUA: Make sure to reject unknown CO message types

Found using sua-sgp-mtr-i-04 from Michael Tuexen's sua-testtool.

Change-Id: Iec5c8deb6cc48a1269fd85243c1350bafd1dd815

1 files changed, 20 insertions, 0 deletions

diff --git a/src/sua.c b/src/sua.c
index f003f7b..fb7545e 100644
--- a/src/sua.c
+++ b/src/sua.c
@@ -519,6 +519,26 @@ static int sua_rx_co(struct osmo_ss7_asp *asp, struct xua_msg *xua)
 {
 	struct osmo_sccp_instance *inst = asp->inst->sccp;
 
+	OSMO_ASSERT(xua->hdr.msg_class == SUA_MSGC_CO);
+
+	switch (xua->hdr.msg_type) {
+	case 0: /* Reserved, permitted by ETSI TS 101 592 5.2.3.2 */
+	case SUA_CO_CORE:
+	case SUA_CO_COAK:
+	case SUA_CO_COREF:
+	case SUA_CO_RELRE:
+	case SUA_CO_RELCO:
+	case SUA_CO_RESCO:
+	case SUA_CO_RESRE:
+	case SUA_CO_CODT:
+	case SUA_CO_CODA:
+	case SUA_CO_COERR:
+	case SUA_CO_COIT:
+		break;
+	default:
+		return SUA_ERR_UNSUPP_MSG_TYPE;
+	}
+
 	/* We feed into SCRC, which then hands the message into
 	 * either SCLC or SCOC, or forwards it to MTP */
 	return scrc_rx_mtp_xfer_ind_xua(inst, xua);