module SGSN_Tests {

import from General_Types all;
import from Osmocom_Types all;
import from NS_Types all;
import from NS_Emulation all;
import from BSSGP_Types all;
import from BSSGP_Emulation all;
import from Osmocom_Gb_Types all;

import from MobileL3_CommonIE_Types all;
import from MobileL3_GMM_SM_Types all;
import from MobileL3_Types all;
import from L3_Templates all;
import from L3_Common all;

import from GSUP_Emulation all;
import from GSUP_Types all;
import from IPA_Emulation all;

modulepar {
	/* IP/port on which we run our internal GSUP/HLR emulation */
	charstring mp_hlr_ip := "127.0.0.1";
	integer mp_hlr_port := 4222;
};

type record GbInstance {
	NS_CT vc_NS,
	BSSGP_CT vc_BSSGP,
	BssgpConfig cfg
};

type component test_CT {
	var GbInstance g_gb[3];

	var GSUP_Emulation_CT vc_GSUP;
	var IPA_Emulation_CT vc_GSUP_IPA;
	/* only to get events from IPA underneath GSUP */
	port IPA_CTRL_PT GSUP_IPA_EVENT;

	var boolean g_initialized := false;
};

type component BSSGP_ConnHdlr extends BSSGP_Client_CT, GSUP_ConnHdlr {
	var BSSGP_ConnHdlrPars g_pars;
	timer g_Tguard;
}

type record SGSN_ConnHdlrNetworkPars {
	boolean expect_ptmsi,
	boolean expect_auth,
	boolean expect_ciph
};

type record BSSGP_ConnHdlrPars {
	/* IMEI of the simulated ME */
	hexstring imei,
	/* IMEI of the simulated MS */
	hexstring imsi,
	/* MSISDN of the simulated MS (probably unused) */
	hexstring msisdn,
	/* P-TMSI allocated to the simulated MS */
	OCT4 p_tmsi optional,
	/* TLLI of the simulated MS */
	OCT4 tlli,
	RoutingAreaIdentificationV ra optional,
	BssgpCellId bssgp_cell_id,
	AuthVector vec optional,
	SGSN_ConnHdlrNetworkPars net,
	float t_guard
};

private function f_init_gb(inout GbInstance gb) runs on test_CT {
	gb.vc_NS := NS_CT.create;
	gb.vc_BSSGP := BSSGP_CT.create;
	/* connect lower end of BSSGP emulation with NS upper port */
	connect(gb.vc_BSSGP:BSCP, gb.vc_NS:NS_SP);
	/* connect lower end of NS emulation to NS codec port (on top of IPL4) */
	map(gb.vc_NS:NSCP, system:NS_CODEC_PORT);

	gb.vc_NS.start(NSStart());
	gb.vc_BSSGP.start(BssgpStart(gb.cfg));
}

private function f_init_gsup(charstring id) runs on test_CT {
	id := id & "-GSUP";
	var GsupOps ops := {
		create_cb := refers(GSUP_Emulation.ExpectedCreateCallback)
	};

	vc_GSUP_IPA := IPA_Emulation_CT.create(id & "-IPA");
	vc_GSUP := GSUP_Emulation_CT.create(id);

	map(vc_GSUP_IPA:IPA_PORT, system:IPA_CODEC_PT);
	connect(vc_GSUP:GSUP, vc_GSUP_IPA:IPA_GSUP_PORT);
	/* we use this hack to get events like ASP_IPA_EVENT_UP */
	connect(vc_GSUP_IPA:IPA_CTRL_PORT, self:GSUP_IPA_EVENT);

	vc_GSUP.start(GSUP_Emulation.main(ops, id));
	vc_GSUP_IPA.start(IPA_Emulation.main_server(mp_hlr_ip, mp_hlr_port));

	/* wait for incoming connection to GSUP port before proceeding */
	timer T := 10.0;
	T.start;
	alt {
		[] GSUP_IPA_EVENT.receive(t_ASP_IPA_EVT_UD(ASP_IPA_EVENT_UP)) { }
		[] T.timeout {
			setverdict(fail, "No connection to GSUP Port");
			self.stop;
		}
	}
}

function f_init() runs on test_CT {
	if (g_initialized == true) {
		return;
	}
	g_initialized := true;
	g_gb[0].cfg := {
		nsei := 96,
		bvci := 196,
		cell_id := {
			ra_id := {
				lai := {
					mcc_mnc := '26242F'H, lac := 13135},
					rac := 0
				},
			cell_id := 20960
		},
		sgsn_role := false
	};

	f_init_gb(g_gb[0]);
	f_init_gsup("SGSN_Test");
}

type function void_fn(charstring id) runs on BSSGP_ConnHdlr;

/* helper function to create, connect and start a BSSGP_ConnHdlr component */
function f_start_handler(void_fn fn, charstring id, GbInstance gb, integer imsi_suffix,
			 float t_guard := 30.0)
runs on test_CT return BSSGP_ConnHdlr {
	var BSSGP_ConnHdlr vc_conn;
	var SGSN_ConnHdlrNetworkPars net_pars := {
		expect_ptmsi := true,
		expect_auth := true,
		expect_ciph := false
	};
	var BSSGP_ConnHdlrPars pars := {
		imei := f_gen_imei(imsi_suffix),
		imsi := f_gen_imsi(imsi_suffix),
		msisdn := f_gen_msisdn(imsi_suffix),
		p_tmsi := omit,
		tlli := f_gprs_tlli_random(),
		ra := omit,
		bssgp_cell_id := gb.cfg.cell_id,
		vec := omit,
		net := net_pars,
		t_guard := t_guard
	};

	vc_conn := BSSGP_ConnHdlr.create(id);
	connect(vc_conn:BSSGP, gb.vc_BSSGP:BSSGP_SP);
	connect(vc_conn:BSSGP_PROC, gb.vc_BSSGP:BSSGP_PROC);

	connect(vc_conn:GSUP, vc_GSUP:GSUP_CLIENT);
	connect(vc_conn:GSUP_PROC, vc_GSUP:GSUP_PROC);

	vc_conn.start(f_handler_init(fn, id, pars));
	return vc_conn;
}

private altstep as_Tguard() runs on BSSGP_ConnHdlr {
	[] g_Tguard.timeout {
		setverdict(fail, "Tguard timeout");
		self.stop;
	}
}

/* first function called in every ConnHdlr */
private function f_handler_init(void_fn fn, charstring id, BSSGP_ConnHdlrPars pars)
runs on BSSGP_ConnHdlr {
	/* do some common stuff like setting up g_pars */
	g_pars := pars;

	/* register with BSSGP core */
	f_bssgp_client_register(g_pars.imsi, g_pars.tlli, g_pars.bssgp_cell_id);
	/* tell GSUP dispatcher to send this IMSI to us */
	f_create_gsup_expect(hex2str(g_pars.imsi));

	g_Tguard.start(pars.t_guard);
	activate(as_Tguard());

	/* call the user-supplied test case function */
	fn.apply(id);
	f_bssgp_client_unregister(g_pars.imsi);
}

/* TODO:
   * RAU without Attach
   * Detach without Attach
   * SM procedures without attach / RAU
   * ATTACH / RAU
   ** with / without authentication
   ** with / without P-TMSI allocation
   ** timeout from HLR on SAI
   ** timeout from HLR on UL
   ** reject from HLR on SAI
   ** reject from HLR on UL
   * re-transmissions of LLC frames
   * PDP Context activation
   ** with different GGSN config in SGSN VTY
   ** with different PDP context type (v4/v6/v46)
   ** timeout from GGSN
   ** reject from GGSN
 */

testcase TC_wait_ns_up() runs on test_CT {
	f_init();
	f_sleep(20.0);
}

altstep as_mm_identity() runs on BSSGP_ConnHdlr {
	var MobileIdentityLV mi;
	[] BSSGP.receive(tr_BD_L3_MT(tr_GMM_ID_REQ('001'B))) {
		mi := valueof(ts_MI_IMSI_LV(g_pars.imsi));
		BSSGP.send(ts_GMM_ID_RESP(mi));
		repeat;
	}
	[] BSSGP.receive(tr_BD_L3_MT(tr_GMM_ID_REQ('010'B))) {
		mi := valueof(ts_MI_IMEI_LV(g_pars.imei));
		BSSGP.send(ts_GMM_ID_RESP(mi));
		repeat;
	}
}

function f_gmm_auth () runs on BSSGP_ConnHdlr {
	var BssgpDecoded bd;
	var PDU_L3_MS_SGSN l3_mo;
	var PDU_L3_SGSN_MS l3_mt;
	var default di := activate(as_mm_identity());
	if (g_pars.net.expect_auth) {
		g_pars.vec := f_gen_auth_vec_2g();
		var GSUP_IE auth_tuple := valueof(ts_GSUP_IE_AuthTuple2G(g_pars.vec.rand,
									 g_pars.vec.sres,
									 g_pars.vec.kc));
		GSUP.receive(tr_GSUP_SAI_REQ(g_pars.imsi));
		GSUP.send(ts_GSUP_SAI_RES(g_pars.imsi, auth_tuple));
		BSSGP.receive(tr_BD_L3_MT(tr_GMM_AUTH_REQ(g_pars.vec.rand))) -> value bd;
		l3_mt := bd.l3_mt;
		var BIT4 ac_ref := l3_mt.msgs.gprs_mm.authenticationAndCipheringRequest.acReferenceNumber.valueField;
		l3_mo := valueof(ts_GMM_AUTH_RESP_2G(ac_ref, g_pars.vec.sres));
		if (ispresent(l3_mt.msgs.gprs_mm.authenticationAndCipheringRequest.imeisvRequest) and
		    l3_mt.msgs.gprs_mm.authenticationAndCipheringRequest.imeisvRequest.valueField == '001'B) {
			l3_mo.msgs.gprs_mm.authenticationAndCipheringResponse.imeisv :=
						valueof(ts_MI_IMEISV_TLV(g_pars.imei & '0'H));
		}
		BSSGP.send(l3_mo);
	}
	deactivate(di);
}

function f_random_RAI(HEX0_3n mcc := '262'H, HEX0_3n mnc := '42'H) return RoutingAreaIdentificationV {
	return f_RAI(mcc, mnc, f_rnd_octstring(2), f_rnd_octstring(1));
}

private function f_TC_attach(charstring id) runs on BSSGP_ConnHdlr {
	var MobileIdentityLV mi;
	var RoutingAreaIdentificationV old_ra := f_random_RAI();

	if (ispresent(g_pars.p_tmsi)) {
		mi := valueof(ts_MI_TMSI_LV(g_pars.p_tmsi));
	} else {
		mi := valueof(ts_MI_IMSI_LV(g_pars.imsi));
	}

	BSSGP.send(ts_GMM_ATTACH_REQ(mi, old_ra, false, false, omit, omit));
	f_gmm_auth();
	/* Expect MSC to perform LU with HLR */
	GSUP.receive(tr_GSUP_UL_REQ(g_pars.imsi));
	GSUP.send(ts_GSUP_ISD_REQ(g_pars.imsi, g_pars.msisdn));
	GSUP.receive(tr_GSUP_ISD_RES(g_pars.imsi));
	GSUP.send(ts_GSUP_UL_RES(g_pars.imsi));

	BSSGP.receive(tr_BD_L3_MT(tr_GMM_ATTACH_ACCEPT(?, ?, ?)));
	BSSGP.send(ts_GMM_ATTACH_COMPL);
	setverdict(pass);
}

testcase TC_attach() runs on test_CT {
	var BSSGP_ConnHdlr vc_conn;
	f_init();
	f_sleep(1.0);
	vc_conn := f_start_handler(refers(f_TC_attach), testcasename(), g_gb[0], 1);
	vc_conn.done;
}

/* MS never responds to ID REQ, expect ATTACH REJECT */
private function f_TC_attach_auth_id_timeout(charstring id) runs on BSSGP_ConnHdlr {
	var MobileIdentityLV mi;
	var RoutingAreaIdentificationV old_ra := f_random_RAI();

	if (ispresent(g_pars.p_tmsi)) {
		mi := valueof(ts_MI_TMSI_LV(g_pars.p_tmsi));
	} else {
		mi := valueof(ts_MI_IMSI_LV(g_pars.imsi));
	}

	BSSGP.send(ts_GMM_ATTACH_REQ(mi, old_ra, false, false, omit, omit));
	alt {
	[] BSSGP.receive(tr_BD_L3(tr_GMM_ID_REQ(?))) {
		/* don't send ID Response */
		repeat;
		}
	[] BSSGP.receive(tr_BD_L3(tr_GMM_ATTACH_REJECT('09'O))) {
		setverdict(pass);
		}
	[] BSSGP.receive(tr_BD_L3(tr_GMM_ATTACH_REJECT(?))) {
		setverdict(fail, "Wrong Attach Reject Cause");
		}
	}
}
testcase TC_attach_auth_id_timeout() runs on test_CT {
	var BSSGP_ConnHdlr vc_conn;
	f_init();
	vc_conn := f_start_handler(refers(f_TC_attach_auth_id_timeout), testcasename(), g_gb[0], 2, 40.0);
	vc_conn.done;
}

/* HLR never responds to SAI REQ, expect ATTACH REJECT */
private function f_TC_attach_auth_sai_timeout(charstring id) runs on BSSGP_ConnHdlr {
	var MobileIdentityLV mi;
	var RoutingAreaIdentificationV old_ra := f_random_RAI();

	if (ispresent(g_pars.p_tmsi)) {
		mi := valueof(ts_MI_TMSI_LV(g_pars.p_tmsi));
	} else {
		mi := valueof(ts_MI_IMSI_LV(g_pars.imsi));
	}

	BSSGP.send(ts_GMM_ATTACH_REQ(mi, old_ra, false, false, omit, omit));
	alt {
	[] as_mm_identity();
	[] GSUP.receive(tr_GSUP_SAI_REQ(g_pars.imsi)); { }
	}
	/* don't send SAI-response from HLR */
	BSSGP.receive(tr_BD_L3(tr_GMM_ATTACH_REJECT(?)));
	setverdict(pass);
}
testcase TC_attach_auth_sai_timeout() runs on test_CT {
	var BSSGP_ConnHdlr vc_conn;
	f_init();
	vc_conn := f_start_handler(refers(f_TC_attach_auth_sai_timeout), testcasename(), g_gb[0], 3);
	vc_conn.done;
}

/* HLR never responds to UL REQ, expect ATTACH REJECT */
private function f_TC_attach_gsup_lu_timeout(charstring id) runs on BSSGP_ConnHdlr {
	var MobileIdentityLV mi;
	var RoutingAreaIdentificationV old_ra := f_random_RAI();

	if (ispresent(g_pars.p_tmsi)) {
		mi := valueof(ts_MI_TMSI_LV(g_pars.p_tmsi));
	} else {
		mi := valueof(ts_MI_IMSI_LV(g_pars.imsi));
	}

	BSSGP.send(ts_GMM_ATTACH_REQ(mi, old_ra, false, false, omit, omit));
	f_gmm_auth();
	/* Expect MSC to perform LU with HLR */
	GSUP.receive(tr_GSUP_UL_REQ(g_pars.imsi));
	/* Never follow-up with ISD_REQ or UL_RES */
	alt {
	[] BSSGP.receive(tr_BD_L3(tr_GMM_ATTACH_REJECT(?))) {
		setverdict(pass);
		}
	[] BSSGP.receive(tr_BD_L3(tr_GMM_ATTACH_ACCEPT(?, ?, ?))) {
		setverdict(fail);
		}
	}
}
testcase TC_attach_gsup_lu_timeout() runs on test_CT {
	var BSSGP_ConnHdlr vc_conn;
	f_init();
	f_sleep(1.0);
	vc_conn := f_start_handler(refers(f_TC_attach_gsup_lu_timeout), testcasename(), g_gb[0], 4);
	vc_conn.done;
}


control {
	execute( TC_attach() );
	execute( TC_attach_auth_id_timeout() );
	execute( TC_attach_auth_sai_timeout() );
	execute( TC_attach_gsup_lu_timeout() );
}


}