module GBProxy_Tests {

/* Osmocom GBProxy test suite in TTCN-3
 * (C) 2020 sysmocom - s.f.m.c. GmbH
 * All rights reserved.
 *
 * Author: Daniel Willmann <dwillmann@sysmocom.de>

 * 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 GSM_Types all;
import from Native_Functions all;
import from NS_Types all;
import from NS_Emulation all;
import from BSSGP_Types all;
import from BSSGP_Emulation all;
import from SCCPasp_Types 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 TELNETasp_PortType all;
import from Osmocom_VTY_Functions all;

import from LLC_Types all;
import from LLC_Templates all;

import from GSM_RR_Types all;

modulepar {
	/* IP/port on which we run our internal GSUP/HLR emulation */
	NSConfigurations_SGSN mp_nsconfig_sgsn := {
		{
			provider := {
				ip := {
					address_family := AF_INET,
					local_udp_port := 7777,
					local_ip := "127.0.0.1",
					remote_udp_port := 23000,
					remote_ip := "127.0.0.1"
				}
			},
			nsvci := 101,
			nsei := 101,
			role_sgsn := true,
			handle_sns := false
		}
	};
	NSConfigurations_PCU mp_nsconfig_pcu := {
		{
			provider := {
				ip := {
					address_family := AF_INET,
					local_udp_port := 21010,
					local_ip := "127.0.0.1",
					remote_udp_port := 23000,
					remote_ip := "127.0.0.1"
				}
			},
			nsvci := 97,
			nsei := 96,
			role_sgsn := false,
			handle_sns := false
		},
		{
			provider := {
				ip := {
					address_family := AF_INET,
					local_udp_port := 21011,
					local_ip := "127.0.0.1",
					remote_udp_port := 23000,
					remote_ip := "127.0.0.1"
				}
			},
			nsvci := 98,
			nsei := 97,
			role_sgsn := false,
			handle_sns := false
		},
		{
			provider := {
				ip := {
					address_family := AF_INET,
					local_udp_port := 21012,
					local_ip := "127.0.0.1",
					remote_udp_port := 23000,
					remote_ip := "127.0.0.1"
				}
			},
			nsvci := 99,
			nsei := 98,
			role_sgsn := false,
			handle_sns := false
		}
	};
};

const integer NUM_BVC_PER_NSE := 3;
type record GbInstance {
	NS_CT vc_NS,
	BSSGP_CT vc_BSSGP,
	BSSGP_BVC_CT vc_BSSGP_BVC[NUM_BVC_PER_NSE],
	BssgpConfig cfg
};

const integer NUM_PCU := 3;
type record length(NUM_PCU) of GbInstance GbInstances_PCU;
type record length(NUM_PCU) of NSConfiguration NSConfigurations_PCU;
type record length(NUM_PCU) of BssgpCellId BssgpCellIds;

const integer NUM_SGSN := 1;
type record length(NUM_SGSN) of GbInstance GbInstances_SGSN;
type record length(NUM_SGSN) of NSConfiguration NSConfigurations_SGSN;

type component test_CT {
	var GbInstances_PCU g_pcu;
	var GbInstances_SGSN g_sgsn;

	port BSSGP_CT_PROC_PT PROC;

	port TELNETasp_PT GBPVTY;

	var boolean g_initialized := false;
	var boolean g_use_echo := false;
};

type component BSSGP_ConnHdlr {
	port BSSGP_PT PCU[NUM_PCU];
	port BSSGP_PT PCU_SIG[NUM_PCU];
	port BSSGP_PROC_PT PCU_PROC[NUM_PCU];
	port BSSGP_PT SGSN[NUM_SGSN];
	port BSSGP_PT SGSN_SIG[NUM_SGSN];
	port BSSGP_PROC_PT SGSN_PROC[NUM_SGSN];

	var BSSGP_ConnHdlrPars g_pars;
	timer g_Tguard;
	var LLC_Entities llc;
}

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

type record BSSGP_ConnHdlrPars {
	/* IMEI of the simulated ME */
	hexstring imei,
	/* IMSI 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,
	OCT3 p_tmsi_sig optional,
	/* TLLI of the simulated MS */
	OCT4 tlli,
	OCT4 tlli_old optional,
	RoutingAreaIdentificationV ra optional,
	BssgpCellIds bssgp_cell_id,
	float t_guard
};

private function f_cellid_to_RAI(in BssgpCellId cell_id) return RoutingAreaIdentificationV {
	/* mcc_mnc is encoded as of 24.008 10.5.5.15 */
	var BcdMccMnc mcc_mnc := cell_id.ra_id.lai.mcc_mnc;

        var RoutingAreaIdentificationV ret := {
                mccDigit1 := mcc_mnc[0],
                mccDigit2 := mcc_mnc[1],
                mccDigit3 := mcc_mnc[2],
                mncDigit3 := mcc_mnc[3],
                mncDigit1 := mcc_mnc[4],
                mncDigit2 := mcc_mnc[5],
                lac := int2oct(cell_id.ra_id.lai.lac, 16),
                rac := int2oct(cell_id.ra_id.rac, 8)
        }
        return ret;
};

private function f_init_gb_pcu(inout GbInstance gb, charstring id, integer offset) runs on test_CT {
	gb.vc_NS := NS_CT.create(id & "-NS(PCU)" & int2str(offset));
	gb.vc_BSSGP := BSSGP_CT.create(id & "-BSSGP(PCU)" & int2str(offset));
	/* connect lower end of BSSGP emulation with NS upper port */
	connect(gb.vc_BSSGP:BSCP, gb.vc_NS:NS_SP);

	gb.vc_NS.start(NSStart(mp_nsconfig_pcu[offset]));
	gb.vc_BSSGP.start(BssgpStart(gb.cfg, id));

	for (var integer i := 0; i < lengthof(gb.cfg.bvc); i := i + 1) {
		connect(self:PROC, gb.vc_BSSGP:PROC);
		gb.vc_BSSGP_BVC[i] := f_bssgp_get_bvci_ct(gb.cfg.bvc[i].bvci, PROC);
		disconnect(self:PROC, gb.vc_BSSGP:PROC);
	}
}

private function f_init_gb_sgsn(inout GbInstance gb, charstring id, integer offset) runs on test_CT {
	gb.vc_NS := NS_CT.create(id & "-NS(SGSN)" & int2str(offset));
	gb.vc_BSSGP := BSSGP_CT.create(id & "-BSSGP(SGSN)" & int2str(offset));
	/* connect lower end of BSSGP emulation with NS upper port */
	connect(gb.vc_BSSGP:BSCP, gb.vc_NS:NS_SP);

	gb.vc_NS.start(NSStart(mp_nsconfig_sgsn[offset]));
	gb.vc_BSSGP.start(BssgpStart(gb.cfg, id));

	for (var integer i := 0; i < lengthof(gb.cfg.bvc); i := i + 1) {
		connect(self:PROC, gb.vc_BSSGP:PROC);
		gb.vc_BSSGP_BVC[i] := f_bssgp_get_bvci_ct(gb.cfg.bvc[i].bvci, PROC);
		disconnect(self:PROC, gb.vc_BSSGP:PROC);
	}
}


private function f_init_vty() runs on test_CT {
	map(self:GBPVTY, system:GBPVTY);
	f_vty_set_prompts(GBPVTY);
	f_vty_transceive(GBPVTY, "enable");
}

/* mcc_mnc is 24.008 10.5.5.15 encoded. 262 42 */
function f_init(BcdMccMnc mcc_mnc := '262F42'H) runs on test_CT {
	var integer i;

	if (g_initialized == true) {
		return;
	}
	g_initialized := true;
	g_pcu[0].cfg := {
		nsei := 96,
		sgsn_role := false,
		bvc := { {
			bvci := 196,
			cell_id := {
				ra_id := {
					lai := {
						mcc_mnc := mcc_mnc, lac := 13135},
						rac := 0
					},
				cell_id := 20960
			},
			depth := BSSGP_DECODE_DEPTH_BSSGP
		} }
	};
	g_pcu[1].cfg := {
		nsei := 97,
		sgsn_role := false,
		bvc := { {
			bvci := 210,
			cell_id := {
				ra_id := {
					lai := {
						mcc_mnc := mcc_mnc, lac := 13200},
						rac := 0
					},
				cell_id := 20961
			},
			depth := BSSGP_DECODE_DEPTH_BSSGP
		} }
	};
	g_pcu[2].cfg := {
		nsei := 98,
		sgsn_role := false,
		bvc := { {
			bvci := 220,
			cell_id := {
				ra_id := {
					lai := {
						mcc_mnc := mcc_mnc, lac := 13300},
						rac := 0
					},
				cell_id := 20962
			},
			depth := BSSGP_DECODE_DEPTH_BSSGP
		} }
	};

	g_sgsn[0].cfg := {
		nsei := 101,
		sgsn_role := true,
		bvc := {
			{
				bvci := 196,
				cell_id := {
					ra_id := {
						lai := {
							mcc_mnc := mcc_mnc, lac := 13135},
							rac := 0
						},
					cell_id := 20960
				},
				depth := BSSGP_DECODE_DEPTH_BSSGP
			},
			{
				bvci := 210,
				cell_id := {
					ra_id := {
						lai := {
							mcc_mnc := mcc_mnc, lac := 13200},
							rac := 0
						},
					cell_id := 20961
				},
				depth := BSSGP_DECODE_DEPTH_BSSGP
			},
			{
				bvci := 220,
				cell_id := {
					ra_id := {
						lai := {
							mcc_mnc := mcc_mnc, lac := 13300},
							rac := 0
						},
					cell_id := 20962
				},
				depth := BSSGP_DECODE_DEPTH_BSSGP
			}
		}
	};

	f_init_vty();
	f_init_gb_sgsn(g_sgsn[0], "GbProxy_Test-SGSN0", 0);
	f_sleep(4.0);
	f_init_gb_pcu(g_pcu[0], "GbProxy_Test-PCU0", 0);
	f_init_gb_pcu(g_pcu[1], "GbProxy_Test-PCU1", 1);
	f_init_gb_pcu(g_pcu[2], "GbProxy_Test-PCU2", 2);
}

function f_cleanup() runs on test_CT {
	self.stop;
}

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, GbInstances_PCU pcu, GbInstances_SGSN sgsn, integer imsi_suffix,
			 float t_guard := 30.0)
runs on test_CT return BSSGP_ConnHdlr {
	var BSSGP_ConnHdlr vc_conn;

	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,
		p_tmsi_sig := omit,
		tlli := f_gprs_tlli_random(),
		tlli_old := omit,
		ra := omit,
		bssgp_cell_id := { pcu[0].cfg.bvc[0].cell_id, pcu[1].cfg.bvc[0].cell_id, pcu[2].cfg.bvc[0].cell_id },
		t_guard := t_guard
	};

	vc_conn := BSSGP_ConnHdlr.create(id);
	// PDU side
	connect(vc_conn:PCU[0], pcu[0].vc_BSSGP_BVC[0]:BSSGP_SP);
	connect(vc_conn:PCU_SIG[0], pcu[0].vc_BSSGP_BVC[0]:BSSGP_SP_SIG);
	connect(vc_conn:PCU_PROC[0], pcu[0].vc_BSSGP_BVC[0]:BSSGP_PROC);
	connect(vc_conn:PCU[1], pcu[1].vc_BSSGP_BVC[0]:BSSGP_SP);
	connect(vc_conn:PCU_SIG[1], pcu[1].vc_BSSGP_BVC[0]:BSSGP_SP_SIG);
	connect(vc_conn:PCU_PROC[1], pcu[1].vc_BSSGP_BVC[0]:BSSGP_PROC);
	connect(vc_conn:PCU[2], pcu[2].vc_BSSGP_BVC[0]:BSSGP_SP);
	connect(vc_conn:PCU_SIG[2], pcu[2].vc_BSSGP_BVC[0]:BSSGP_SP_SIG);
	connect(vc_conn:PCU_PROC[2], pcu[2].vc_BSSGP_BVC[0]:BSSGP_PROC);
	// SGSN side
	connect(vc_conn:SGSN[0], sgsn[0].vc_BSSGP_BVC[0]:BSSGP_SP);
	connect(vc_conn:SGSN_SIG[0], sgsn[0].vc_BSSGP_BVC[0]:BSSGP_SP_SIG);
	connect(vc_conn:SGSN_PROC[0], sgsn[0].vc_BSSGP_BVC[0]:BSSGP_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");
		mtc.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;

	llc := f_llc_create(false);


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

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

/* TODO:
   * Detach without Attach
   * SM procedures without attach / RAU
   * ATTACH / RAU
   ** with / without authentication
   ** with / without P-TMSI allocation
   * 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
   ** multiple / secondary PDP context
 */

private function f_TC_BVC_bringup(charstring id) runs on BSSGP_ConnHdlr {
	f_sleep(5.0);
	setverdict(pass);
}

testcase TC_BVC_bringup() runs on test_CT {
	var BSSGP_ConnHdlr vc_conn;
	f_init();

	vc_conn := f_start_handler(refers(f_TC_BVC_bringup), testcasename(), g_pcu, g_sgsn, 51);
	vc_conn.done;

	f_cleanup();
}

friend function f_bssgp_suspend(integer ran_idx := 0) runs on BSSGP_ConnHdlr return OCT1 {
	timer T := 5.0;
	var PDU_BSSGP rx_pdu;
	PCU_SIG[ran_idx].send(ts_BSSGP_SUSPEND(g_pars.tlli, g_pars.bssgp_cell_id[ran_idx].ra_id));
	T.start;
	alt {
	[] PCU_SIG[ran_idx].receive(tr_BSSGP_SUSPEND_ACK(g_pars.tlli, g_pars.bssgp_cell_id[ran_idx].ra_id, ?)) -> value rx_pdu {
		return rx_pdu.pDU_BSSGP_SUSPEND_ACK.suspend_Reference_Number.suspend_Reference_Number_value;
		}
	[] PCU_SIG[ran_idx].receive(tr_BSSGP_SUSPEND_NACK(g_pars.tlli, g_pars.bssgp_cell_id[ran_idx].ra_id, ?)) -> value rx_pdu {
		setverdict(fail, "SUSPEND-NACK in response to SUSPEND for TLLI ", g_pars.tlli);
		mtc.stop;
		}
	[] T.timeout {
		setverdict(fail, "No SUSPEND-ACK in response to SUSPEND for TLLI ", g_pars.tlli);
		mtc.stop;
		}
	}
	return '00'O;
}

friend function f_bssgp_resume(OCT1 susp_ref, integer ran_idx := 0) runs on BSSGP_ConnHdlr {
	timer T := 5.0;
	PCU_SIG[ran_idx].send(ts_BSSGP_RESUME(g_pars.tlli, g_pars.bssgp_cell_id[ran_idx].ra_id, susp_ref));
	T.start;
	alt {
	[] PCU_SIG[ran_idx].receive(tr_BSSGP_RESUME_ACK(g_pars.tlli, g_pars.bssgp_cell_id[ran_idx].ra_id));
	[] PCU_SIG[ran_idx].receive(tr_BSSGP_RESUME_NACK(g_pars.tlli, g_pars.bssgp_cell_id[ran_idx].ra_id,
?)) {
		setverdict(fail, "RESUME-NACK in response to RESUME for TLLI ", g_pars.tlli);
		mtc.stop;
		}
	[] T.timeout {
		setverdict(fail, "No RESUME-ACK in response to SUSPEND for TLLI ", g_pars.tlli);
		mtc.stop;
		}
	}
}


control {
	execute( TC_BVC_bringup() );
}


}