ipa/MSC_ConnectionHandler.ttcn

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);
			}
		}
	}
}

}