module BSSAP_LE_Adapter {

/* This module implements a 'dumb' BSSAP_LE adapter.  It creates the M3UA and SCCP components and stacks a
 * BSSAP_LE codec port on top.  As a result, it provides the ability to transceive SCCP-User-SAP primitives
 * with deoded BSSAP_LE payload.  Use this if you want to have full control about what you transmit or
 * receive, without any automatisms in place.  Allows you to refuse connections or other abnormal behavior. */

/* (C) 2017-2020 Harald Welte <laforge@gnumonks.org>
 * contributions by sysmocom - s.f.m.c. GmbH
 * All rights reserved.
 *
 * Released under the terms of GNU General Public License, Version 2 or
 * (at your option) any later version.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

import from General_Types all;
import from Osmocom_Types all;

import from M3UA_Emulation all;
import from MTP3asp_Types all;
import from MTP3asp_PortType all;

import from IPA_Emulation all;

import from SCCP_Types all;
import from SCCPasp_Types all;
import from SCCP_Emulation all;
import from SCCP_Templates all;

import from SCTPasp_Types all;
import from SCTPasp_PortType all;

import from BSSMAP_LE_Templates all;
import from BSSAP_LE_Emulation all;

type record BSSAP_LE_Adapter {
	/* component references */
	M3UA_CT vc_M3UA,		/* only in 3GPP AoIP */
	SCCP_CT vc_SCCP,

	MSC_SCCP_MTP3_parameters sccp_pars,
	SCCP_PAR_Address sccp_addr_own,
	SCCP_PAR_Address sccp_addr_peer,

	/* handler mode */
	BSSAP_LE_Emulation_CT vc_BSSAP_LE
}

type record BSSAP_LE_Configuration {
	charstring sccp_service_type,
	SCTP_Association_Address sctp_addr,
	integer own_pc,
	integer own_ssn,
	integer peer_pc,
	integer peer_ssn,
	octetstring sio,
	integer rctx optional
};
type record of BSSAP_LE_Configuration BSSAP_LE_Configurations;

private function init_pars(inout BSSAP_LE_Adapter ba, in BSSAP_LE_Configuration cfg) {
	ba.sccp_pars := {
		sio := {
			ni := substr(oct2bit(cfg.sio),0,2),
			prio := substr(oct2bit(cfg.sio),2,2),
			si := substr(oct2bit(cfg.sio),4,4)
		},
		opc := cfg.own_pc,
		dpc := cfg.peer_pc,
		sls := 0,
		sccp_serviceType := cfg.sccp_service_type,
		ssn := cfg.own_ssn
	};
	ba.sccp_addr_own := valueof(ts_SccpAddr_PC_SSN(cfg.own_pc, cfg.own_ssn, cfg.sio, cfg.sccp_service_type));
	ba.sccp_addr_peer := valueof(ts_SccpAddr_PC_SSN(cfg.peer_pc, cfg.peer_ssn, cfg.sio, cfg.sccp_service_type));
}


function f_bssap_le_adapter_init(inout BSSAP_LE_Adapter ba, in BSSAP_LE_Configuration cfg, charstring id,
				  template BssapLeOps ops) {
	init_pars(ba, cfg);
	ops.sccp_addr_local := ba.sccp_addr_own;
	ops.sccp_addr_peer := ba.sccp_addr_peer;

	var template (omit) integer rctx;
	if (not ispresent(cfg.rctx)) {
		rctx := omit;
	} else {
		rctx := cfg.rctx;
	}

	/* create components */
	ba.vc_SCCP := SCCP_CT.create(id & "-SCCP") alive;
	if (isvalue(ops)) {
		ba.vc_BSSAP_LE := BSSAP_LE_Emulation_CT.create(id & "-BSSAP_LE") alive;
	} else {
		ba.vc_BSSAP_LE := null;
	}
	ba.vc_M3UA := M3UA_CT.create(id & "-M3UA") alive;
	map(ba.vc_M3UA:SCTP_PORT, system:sctp);
	/* connect MTP3 service provider (M3UA) to lower side of SCCP */
	connect(ba.vc_M3UA:MTP3_SP_PORT, ba.vc_SCCP:MTP3_SCCP_PORT);
	ba.vc_M3UA.start(f_M3UA_Emulation(cfg.sctp_addr, rctx));

	if (isvalue(ops)) {
		timer T := 5.0;
		T.start;
		//T.timeout;
		/* connect BSSNAP component to upper side of SCCP */
		log("Connecting BSSAP_LE_Emulation to SCCP_SP_PORT");
		connect(ba.vc_BSSAP_LE:BSSAP_LE, ba.vc_SCCP:SCCP_SP_PORT);
		log("Starting BSSAP_LE_Emulation");
		ba.vc_BSSAP_LE.start(BSSAP_LE_Emulation.main(valueof(ops), ""));
	}


}

function f_bssap_le_adapter_start(inout BSSAP_LE_Adapter ba) {
	ba.vc_SCCP.start(SCCPStart(ba.sccp_pars));
}

function f_bssap_le_adapter_cleanup(inout BSSAP_LE_Adapter ba) {
	if (ba.vc_BSSAP_LE != null) {
		disconnect(ba.vc_BSSAP_LE:BSSAP_LE, ba.vc_SCCP:SCCP_SP_PORT);
		ba.vc_BSSAP_LE.stop;
	}
	unmap(ba.vc_M3UA:SCTP_PORT, system:sctp);
	disconnect(ba.vc_M3UA:MTP3_SP_PORT, ba.vc_SCCP:MTP3_SCCP_PORT);
	ba.vc_M3UA.stop;
	ba.vc_SCCP.stop;
}


}