osmux: Introduce mgcp_conn_rtp_is_osmux() helper

This is going to be useful to know if a conn is to use Osmux without
looking at implementation details. Currently we have some duplicated
information (type, osmux.state, etc.) which we may want to refactor
later. This will allow changing implementation details without caring
much about rest of code.

Change-Id: Ib5a239fdbc319bcb16317f5e959d9a724b7a444a

include/osmocom/mgcp/mgcp_internal.h

@@ -312,6 +312,11 @@ void mgcp_rtp_annex_count(struct mgcp_endpoint *endp, struct mgcp_rtp_state *sta
 
 int mgcp_set_ip_tos(int fd, int tos);
 
+/* Was conn configured to handle Osmux? */
+static inline bool mgcp_conn_rtp_is_osmux(const struct mgcp_conn_rtp *conn) {
+	return conn->type == MGCP_OSMUX_BSC || conn->type == MGCP_OSMUX_BSC_NAT;
+}
+
 enum {
 	MGCP_DEST_NET = 0,
 	MGCP_DEST_BTS,