module PCU_Tests_NS {

/* Osmocom PCU test suite for IP Sub-Network-Service (SNS) in TTCN-3
 * (C) 2018-2019 Harald Welte <laforge@gnumonks.org>
 * 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 PCU_Tests all;
import from SGSN_Components all;
import from Osmocom_Gb_Types all;
import from NS_CodecPort all;
import from NS_Types all;
import from BSSGP_Types all;
import from UD_Types all;
import from NS_CodecPort all;
import from NS_CodecPort_CtrlFunct all;
import from NS_Emulation all;
import from Native_Functions all;
import from IPL4asp_Types all;
import from PCUIF_Types all;
import from PCUIF_CodecPort all;

type component RAW_NS_CT {
	/* UDP port towards the bottom (IUT) */
	port NS_CODEC_PT NSCP[4];
	var ConnectionId g_ns_conn_id[4] := {-1, -1, -1, -1};
	var NSConfiguration g_nsconfig[4];
	timer g_T_guard;
}

type component RAW_PCU_CT {
	/* PCUIF (we emulate the BTS part) */
	port PCUIF_CODEC_PT PCU;
	var ConnectionId g_pcu_conn_id := -1;
}

type component RAW_Test_CT extends RAW_NS_CT, RAW_PCU_CT {
}

private altstep as_Tguard() runs on RAW_NS_CT {
	[] g_T_guard.timeout {
		setverdict(fail, "Timeout of T_guard");
		mtc.stop;
		}
}

function f_init_pcuif() runs on RAW_PCU_CT {
	var PCUIF_info_ind info_ind;
	map(self:PCU, system:PCU);


	info_ind := valueof(ts_PCUIF_INFO_default);

	/* Connect the Unix Domain Socket */
	g_pcu_conn_id := f_pcuif_listen(PCU, mp_pcu_sock_path);
	PCU.receive(UD_connected:?);

	/* Wait for PCU_VERSION and return INFO_IND */
	PCU.receive(t_SD_PCUIF(g_pcu_conn_id, tr_PCUIF_TXT_IND(0, PCU_VERSION, ?)));
	/* FIXME: make sure to use parameters from mp_gb_cfg.cell_id in the PCU INFO IND */
	var template PCUIF_Message info_ind_msg := ts_PCUIF_INFO_IND(0, info_ind);
	PCU.send(t_SD_PCUIF(g_pcu_conn_id, info_ind_msg));
}

function f_pcuif_tx(template (value) PCUIF_Message msg) runs on RAW_PCU_CT {
	PCU.send(t_SD_PCUIF(g_pcu_conn_id, msg));
}

function f_init_ns_codec(integer idx := 0, float guard_secs := 60.0) runs on RAW_NS_CT {
	var Result res;

	if (not g_T_guard.running) {
		g_T_guard.start(guard_secs);
		activate(as_Tguard());
	}

	if (not isbound(g_nsconfig) or not isbound(g_nsconfig[idx])) {
		/* copy most parts from mp_nsconfig */
		g_nsconfig[idx] := mp_nsconfig;
		/* adjust those parts different for each NS-VC */
		g_nsconfig[idx].nsvci := mp_nsconfig.nsvci + idx;
		g_nsconfig[idx].local_udp_port := mp_nsconfig.local_udp_port + idx;
	}

	map(self:NSCP[idx], system:NSCP);
	/* Connect the UDP socket */
	log("connecting NSCP[", idx, "] to ", g_nsconfig[idx]);
	res := f_IPL4_connect(NSCP[idx], g_nsconfig[idx].remote_ip, g_nsconfig[idx].remote_udp_port,
				g_nsconfig[idx].local_ip, g_nsconfig[idx].local_udp_port, 0, { udp := {}});
	if (not ispresent(res.connId)) {
		setverdict(fail, "Could not connect NS UDP socket, check your configuration ", g_nsconfig[idx]);
		mtc.stop;
	}
	g_ns_conn_id[idx] := res.connId;

}

function f_ns_exp(template PDU_NS exp_rx, integer idx := 0) runs on RAW_NS_CT return PDU_NS {
	var NS_RecvFrom nrf;
	log("f_ns_exp() expecting ", exp_rx);
	alt {
	[] NSCP[idx].receive(t_NS_RecvFrom(exp_rx)) -> value nrf { }
	[] NSCP[idx].receive {
		setverdict(fail, "Received unexpected NS: ", nrf);
		mtc.stop;
		}
	}
	return nrf.msg;
}

/* perform outbound NS-ALIVE procedure */
function f_outgoing_ns_alive(integer idx := 0) runs on RAW_NS_CT {
	NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], t_NS_ALIVE));
	alt {
	[] NSCP[idx].receive(t_NS_RecvFrom(t_NS_ALIVE_ACK));
	[] NSCP[idx].receive { repeat; }
	}
}

/* perform outbound NS-ALIVE procedure */
function f_outgoing_ns_alive_no_ack(integer idx := 0, float tout := 10.0) runs on RAW_NS_CT {
	timer T := tout;
	NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], t_NS_ALIVE));
	T.start;
	alt {
	[] NSCP[idx].receive(t_NS_RecvFrom(t_NS_ALIVE_ACK)) {
		setverdict(fail, "Received unexpected NS-ALIVE ACK");
		}
	[] NSCP[idx].receive { repeat; }
	[] T.timeout {
		setverdict(pass);
		}
	}
}

/* ensure no matching message is received within 'tout' */
function f_ensure_no_ns(template PDU_NS ns := ?, integer idx := 0, float tout := 3.0)
runs on RAW_Test_CT {
	timer T := tout;
	T.start;
	alt {
	[] NSCP[idx].receive(t_NS_RecvFrom(ns)) {
		setverdict(fail, "NS-ALIVE from unconfigured (possibly initial) endpoint");
		}
	[] T.timeout {
		setverdict(pass);
		}
	}
}

/* perform outbound NS-BLOCK procedure */
function f_outgoing_ns_block(NsCause cause, integer idx := 0) runs on RAW_NS_CT {
	NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], ts_NS_BLOCK(cause, g_nsconfig[idx].nsvci)));
	alt {
	[] NSCP[idx].receive(t_NS_RecvFrom(tr_NS_BLOCK_ACK(g_nsconfig[idx].nsvci)));
	[] NSCP[idx].receive { repeat; }
	}
}

/* receive NS-ALIVE and ACK it */
altstep as_rx_alive_tx_ack(boolean oneshot := false, integer idx := 0) runs on RAW_NS_CT {
	[] NSCP[idx].receive(t_NS_RecvFrom(t_NS_ALIVE)) {
		NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], t_NS_ALIVE_ACK));
		if (not oneshot) { repeat; }
		}
}

/* Transmit BSSGP RESET for given BVCI and expect ACK */
function f_tx_bvc_reset_rx_ack(BssgpBvci bvci, integer idx := 0, boolean exp_ack := true)
runs on RAW_NS_CT {
	var PDU_BSSGP bssgp_tx := valueof(ts_BVC_RESET(BSSGP_CAUSE_NET_SV_CAP_MOD_GT_ZERO_KBPS, bvci,
							mp_gb_cfg.cell_id));
	timer T := 5.0;
	NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], ts_NS_UNITDATA(t_SduCtrlB, 0, enc_PDU_BSSGP(bssgp_tx))));
	T.start;
	alt {
	[exp_ack] NSCP[idx].receive(t_NS_RecvFrom(tr_NS_UNITDATA(t_SduCtrlB, 0,
						  decmatch tr_BVC_RESET_ACK(bvci, ?)))) {
		setverdict(pass);
		}
	[exp_ack] T.timeout {
		setverdict(fail, "No response to BVC-RESET");
		}
	[not exp_ack] T.timeout {
		setverdict(pass);
		}
	[] NSCP[idx].receive { repeat; }
	}
}

/* Receive a BSSGP RESET for given BVCI and ACK it */
altstep as_rx_bvc_reset_tx_ack(BssgpBvci bvci, boolean oneshot := false, integer idx := 0) runs on RAW_NS_CT {
	var NS_RecvFrom ns_rf;
	/* FIXME: nail down received cell_id in match */
	[] NSCP[idx].receive(t_NS_RecvFrom(tr_NS_UNITDATA(t_SduCtrlB, 0,
						  decmatch tr_BVC_RESET(?, bvci, ?))))
								-> value ns_rf {
		var PDU_BSSGP bssgp_rx := dec_PDU_BSSGP(ns_rf.msg.pDU_NS_Unitdata.nS_SDU);
		var PDU_BSSGP bssgp_tx := valueof(ts_BVC_RESET_ACK(bvci, mp_gb_cfg.cell_id));
		NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], ts_NS_UNITDATA(t_SduCtrlB, 0, enc_PDU_BSSGP(bssgp_tx))));
		if (not oneshot) { repeat; }
		}
}


/* Receive a BSSGP UNBLOCK for given BVCI and ACK it */
altstep as_rx_bvc_unblock_tx_ack(BssgpBvci bvci, boolean oneshot := false, integer idx := 0) runs on RAW_NS_CT {
	var NS_RecvFrom ns_rf;
	[] NSCP[idx].receive(t_NS_RecvFrom(tr_NS_UNITDATA(t_SduCtrlB, 0,
						  decmatch t_BVC_UNBLOCK(bvci))))
								-> value ns_rf {
		var PDU_BSSGP bssgp_rx := dec_PDU_BSSGP(ns_rf.msg.pDU_NS_Unitdata.nS_SDU);
		var PDU_BSSGP bssgp_tx := valueof(t_BVC_UNBLOCK_ACK(bvci));
		NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], ts_NS_UNITDATA(t_SduCtrlB, 0, enc_PDU_BSSGP(bssgp_tx))));
		if (not oneshot) { repeat; }
		}
}

/* Receive a BSSGP FLOW-CONTROL-BVC and ACK it */
altstep as_rx_bvc_fc_tx_ack(BssgpBvci bvci, boolean oneshot := false, integer idx := 0) runs on RAW_NS_CT {
	var NS_RecvFrom ns_rf;
	[] NSCP[idx].receive(t_NS_RecvFrom(tr_NS_UNITDATA(t_SduCtrlB, bvci,
						  decmatch tr_BVC_FC_BVC)))
								-> value ns_rf {
		var PDU_BSSGP bssgp_rx := dec_PDU_BSSGP(ns_rf.msg.pDU_NS_Unitdata.nS_SDU);
		var OCT1 tag := bssgp_rx.pDU_BSSGP_FLOW_CONTROL_BVC.tag.unstructured_Value;
		var PDU_BSSGP bssgp_tx := valueof(t_BVC_FC_BVC_ACK(tag));
		NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], ts_NS_UNITDATA(t_SduCtrlB, bvci, enc_PDU_BSSGP(bssgp_tx))));
		if (not oneshot) { repeat; }
		}
}

/**********************************************************************************
 * Classic Gb/IP bring-up test cases using NS-{RESET,BLOCK,UNBLOCK} and no IP-SNS *
 **********************************************************************************/

/* Receive a NS-RESET and ACK it */
private altstep as_rx_ns_reset_ack(boolean oneshot := false, integer idx := 0) runs on RAW_NS_CT {
	var NS_RecvFrom ns_rf;
	[] NSCP[idx].receive(t_NS_RecvFrom(tr_NS_RESET(NS_CAUSE_OM_INTERVENTION, g_nsconfig[idx].nsvci,
						  g_nsconfig[idx].nsei))) -> value ns_rf {
		NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], ts_NS_RESET_ACK(g_nsconfig[idx].nsvci,
									    g_nsconfig[idx].nsei)));
		if (not oneshot) { repeat; }
		}
}
/* Receive a NS-UNBLOCK and ACK it */
private altstep as_rx_ns_unblock_ack(boolean oneshot := false, integer idx := 0) runs on RAW_NS_CT {
	var NS_RecvFrom ns_rf;
	[] NSCP[idx].receive(t_NS_RecvFrom(t_NS_UNBLOCK)) -> value ns_rf {
		NSCP[idx].send(t_NS_Send(g_ns_conn_id[idx], t_NS_UNBLOCK_ACK));
		if (not oneshot) { repeat; }
		}
}

/* test the NS-RESET procedure */
testcase TC_ns_reset() runs on RAW_Test_CT {
	f_init_ns_codec();
	f_init_pcuif();


	/* Expect inbound NS-RESET procedure */
	as_rx_ns_reset_ack(oneshot := true);
	setverdict(pass);
}

/* ensure NS-RESET are re-transmitted */
testcase TC_ns_reset_retrans() runs on RAW_Test_CT {
	f_init_ns_codec();
	f_init_pcuif();

	var integer i;
	for (i := 0; i < 3; i := i+1) {
		NSCP[0].receive(t_NS_RecvFrom(tr_NS_RESET(NS_CAUSE_OM_INTERVENTION,
							g_nsconfig[0].nsvci, g_nsconfig[0].nsei)));
	}

	/* Expect inbound NS-RESET procedure */
	as_rx_ns_reset_ack(oneshot := true);
	setverdict(pass);
}

/* test the inbound NS-ALIVE procedure after NS-RESET */
testcase TC_ns_alive() runs on RAW_Test_CT {
	f_init_ns_codec();
	f_init_pcuif();

	/* Expect inbound NS-RESET procedure */
	as_rx_ns_reset_ack(oneshot := true);

	/* wait for one ALIVE cycle, then ACK any further ALIVE in the background */
	as_rx_alive_tx_ack(oneshot := true);
	setverdict(pass);
}

/* Test for NS-RESET after NS-ALIVE timeout */
testcase TC_ns_alive_timeout_reset() runs on RAW_Test_CT {
	f_init_ns_codec(guard_secs := 100.0);
	f_init_pcuif();

	/* Expect inbound NS-RESET procedure */
	as_rx_ns_reset_ack(oneshot := true);

	/* wait for at least one NS-ALIVE */
	NSCP[0].receive(t_NS_RecvFrom(t_NS_ALIVE));

	/* wait for NS-RESET to re-appear, ignoring any NS-ALIVE until then */
	alt {
	[] as_rx_ns_reset_ack(oneshot := true) { setverdict(pass); }
	[] NSCP[0].receive(t_NS_RecvFrom(t_NS_ALIVE)) { repeat; }
	}
}

/* test for NS-RESET/NS-ALIVE/NS-UNBLOCK */
testcase TC_ns_unblock() runs on RAW_Test_CT {
	f_init_ns_codec();
	f_init_pcuif();

	/* Expect inbound NS-RESET procedure */
	as_rx_ns_reset_ack(oneshot := true);

	/* wait for one ALIVE cycle, then ACK any further ALIVE in the background */
	as_rx_alive_tx_ack(oneshot := true);
	activate(as_rx_alive_tx_ack());

	as_rx_ns_unblock_ack(oneshot := true);
	setverdict(pass);
}

/* test for NS-UNBLOCK re-transmissions */
testcase TC_ns_unblock_retrans() runs on RAW_Test_CT {
	f_init_ns_codec();
	f_init_pcuif();

	/* Expect inbound NS-RESET procedure */
	as_rx_ns_reset_ack(oneshot := true);

	/* wait for one ALIVE cycle, then ACK any further ALIVE in the background */
	as_rx_alive_tx_ack(oneshot := true);
	activate(as_rx_alive_tx_ack());

	/* wait for first NS-UNBLOCK, don't respond */
	NSCP[0].receive(t_NS_RecvFrom(t_NS_UNBLOCK));

	/* wait for re-transmission of NS-UNBLOCK */
	as_rx_ns_unblock_ack(oneshot := true);
	setverdict(pass);
}

/* full bring-up of the Gb link for NS and BSSGP layer up to BVC-FC */
testcase TC_ns_full_bringup() runs on RAW_Test_CT {
	f_init_ns_codec();
	f_init_pcuif();

	/* Expect inbound NS-RESET procedure */
	as_rx_ns_reset_ack(oneshot := true);

	/* wait for one ALIVE cycle, then ACK any further ALIVE in the background */
	as_rx_alive_tx_ack(oneshot := true);
	activate(as_rx_alive_tx_ack());

	as_rx_ns_unblock_ack(oneshot := true);

	f_outgoing_ns_alive();

	/* Expect BVC-RESET for signaling (0) and ptp BVCI */
	as_rx_bvc_reset_tx_ack(0, oneshot := true);
	as_rx_bvc_reset_tx_ack(mp_gb_cfg.bvci, oneshot := true);
	as_rx_bvc_unblock_tx_ack(mp_gb_cfg.bvci, oneshot := true);

	/* wait for one FLOW-CONTROL BVC and then ACK any further in the future */
	as_rx_bvc_fc_tx_ack(mp_gb_cfg.bvci, oneshot := true);
	activate(as_rx_bvc_fc_tx_ack(mp_gb_cfg.bvci));
	setverdict(pass);
}

/* test outbound (SGSN-originated) NS-BLOCK procedure */
testcase TC_ns_so_block() runs on RAW_Test_CT {
	f_init_ns_codec();
	f_init_pcuif();

	/* Expect inbound NS-RESET procedure */
	as_rx_ns_reset_ack(oneshot := true);

	/* wait for one ALIVE cycle, then ACK any further ALIVE in the background */
	as_rx_alive_tx_ack(oneshot := true);
	activate(as_rx_alive_tx_ack());

	as_rx_ns_unblock_ack(oneshot := true);

	f_outgoing_ns_alive();

	f_outgoing_ns_block(NS_CAUSE_EQUIPMENT_FAILURE);
	setverdict(pass);
}


control {
	execute( TC_ns_reset() );
	execute( TC_ns_reset_retrans() );
	execute( TC_ns_alive() );
	execute( TC_ns_alive_timeout_reset() );
	execute( TC_ns_unblock() );
	execute( TC_ns_unblock_retrans() );
	execute( TC_ns_full_bringup() );
	execute( TC_ns_so_block() );
}

}