IPA/MSC/BSC Emulation: Framework for handling multiple SCCP connections
diff --git a/ipa/MSC_ConnectionHandler.ttcn b/ipa/MSC_ConnectionHandler.ttcn
new file mode 100644
index 0000000..0d7cd20
--- /dev/null
+++ b/ipa/MSC_ConnectionHandler.ttcn
@@ -0,0 +1,86 @@
+module MSC_ConnectionHandler {
+
+import from General_Types all;
+import from Osmocom_Types all;
+import from SCCPasp_Types all;
+import from BSSAP_Types all;
+import from BSSMAP_Emulation all;
+import from BSSMAP_Templates all;
+
+/* this component represents a single subscriber connection at the MSC.
+ * There is a 1:1 mapping between SCCP connections and BSSAP_ConnHdlr components.
+ * We inherit all component variables, ports, functions, ... from BSSAP_ConnHdlr */
+type component MSC_ConnHdlr extends BSSAP_ConnHdlr {
+ /* E1 timeslot that is allocated to this component/connection */
+ var uint5_t g_e1_timeslot;
+ /* SCCP Connecction Identifier for the underlying SCCP connection */
+ var integer g_sccp_conn_id;
+}
+
+/* Callback function from general BSSMAP_Emulation whenever a new incoming
+ * SCCP connection arrivces. Must create + start a new component */
+private function CreateCallback(ASP_SCCP_N_CONNECT_ind conn_ind)
+runs on BSSMAP_Emulation_CT return BSSAP_ConnHdlr {
+ var MSC_ConnHdlr vc_conn;
+ /* Create a new BSSAP_ConnHdlr component */
+ vc_conn := MSC_ConnHdlr.create;
+ /* connect it to the port */
+ connect(vc_conn:BSSAP, self:CLIENT);
+ /* start it */
+ vc_conn.start(MSC_ConnectionHandler.main(conn_ind.connectionId, conn_ind.connectionId));
+ return vc_conn;
+}
+
+/* Callback function from general BSSMAP_Emulation whenever a connectionless
+ * BSSMAP message arrives. Can retunr a PDU_BSSAP that should be sent in return */
+private function UnitdataCallback(PDU_BSSAP bssap)
+runs on BSSMAP_Emulation_CT return template PDU_BSSAP {
+ var template PDU_BSSAP resp := omit;
+
+ if (match(bssap, tr_BSSMAP_Reset)) {
+ resp := ts_BSSMAP_ResetAck;
+ }
+
+ return resp;
+}
+
+const BssmapOps MSC_BssmapOps := {
+ create_cb := refers(CreateCallback),
+ unitdata_cb := refers(UnitdataCallback)
+}
+
+/* main function processing various incoming events */
+function main(integer connection_id, integer timeslot) runs on MSC_ConnHdlr {
+ g_sccp_conn_id := connection_id;
+ g_e1_timeslot := timeslot
+
+ while (true) {
+ var PDU_BSSAP bssap;
+ alt {
+ /* new SCCP-level connection indication from BSC */
+ [] BSSAP.receive(tr_BSSMAP_ComplL3) -> value bssap {
+ /* respond with ASSIGNMENT CMD */
+ BSSAP.send(ts_BSSMAP_AssignmentCmd(0, g_e1_timeslot));
+ /* FIXME: Send MGCP */
+ }
+ /*
+ [] BSSAP.receive(tr_BSSMAP_AssignmentCompl) {
+ }
+ [] BSSAP.receive(tr_BSSMAP_AssignmentFail) {
+ }
+ */
+ /* TODO: CLEAR REQUEST from BSS */
+ /* TODO: CLEAR COMPLETE from BSS (response to CLEAR COMMAND) */
+
+ [] BSSAP.receive(BSSAP_Conn_Prim:MSC_CONN_PRIM_DISC_IND) {
+ self.stop;
+ }
+
+ [] BSSAP.receive(PDU_BSSAP:?) -> value bssap {
+ log("Received unhandled SCCP-CO: ", bssap);
+ }
+ }
+ }
+}
+
+}