From 49888a65dcf1f8d94411aa0724530b8c188c3237 Mon Sep 17 00:00:00 2001
From: Eric Wild <ewild@sysmocom.de>
Date: Wed, 30 Mar 2022 03:16:11 +0200
Subject: [PATCH] ran emulation: allow multiple reset attempts

bsc-nat introduces a delay that will lead to failed tests, since the
reset attempt happens too early and times out, and the tests do not
retry.

Change-Id: I9f6db2a24e984eef31e76f9d42a80eb6a1bb6928
---
 bsc-nat/BSC_MS_ConnectionHandler.ttcn |  1 +
 bsc-nat/MSC_ConnectionHandler.ttcn    |  1 +
 library/RAN_Emulation.ttcnpp          | 31 +++++++++++++++++----------
 msc/BSC_ConnectionHandler.ttcn        |  1 +
 msc/MSC_Tests.ttcn                    |  2 ++
 5 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/bsc-nat/BSC_MS_ConnectionHandler.ttcn b/bsc-nat/BSC_MS_ConnectionHandler.ttcn
index f011c39fe..1a3f951c0 100644
--- a/bsc-nat/BSC_MS_ConnectionHandler.ttcn
+++ b/bsc-nat/BSC_MS_ConnectionHandler.ttcn
@@ -74,6 +74,7 @@ const RanOps BSC_MS_RanOps := {
 	protocol := RAN_PROTOCOL_BSSAP,
 	transport := BSSAP_TRANSPORT_AoIP,
 	use_osmux := false,
+	bssap_reset_retries := 1,
 	sccp_addr_local := omit,
 	sccp_addr_peer := omit
 }
diff --git a/bsc-nat/MSC_ConnectionHandler.ttcn b/bsc-nat/MSC_ConnectionHandler.ttcn
index e4d381669..fdf08de77 100644
--- a/bsc-nat/MSC_ConnectionHandler.ttcn
+++ b/bsc-nat/MSC_ConnectionHandler.ttcn
@@ -104,6 +104,7 @@ const RanOps MSC_RanOps := {
 	protocol := RAN_PROTOCOL_BSSAP,
 	transport := BSSAP_TRANSPORT_AoIP,
 	use_osmux := false,
+	bssap_reset_retries := 1,
 	sccp_addr_local := omit,
 	sccp_addr_peer := omit
 }
diff --git a/library/RAN_Emulation.ttcnpp b/library/RAN_Emulation.ttcnpp
index d87ee9cab..e6d36e66c 100644
--- a/library/RAN_Emulation.ttcnpp
+++ b/library/RAN_Emulation.ttcnpp
@@ -521,20 +521,28 @@ runs on RAN_Emulation_CT return template PDU_BSSAP {
 function f_bssap_reset(SCCP_PAR_Address peer, SCCP_PAR_Address own) runs on RAN_Emulation_CT {
 	timer T := 5.0;
 	var boolean append_osmux_support := append_osmux_ie();
+	var integer attempts := g_ran_ops.bssap_reset_retries;
 
-	BSSAP.send(ts_BSSAP_UNITDATA_req(peer, own, ts_BSSMAP_Reset(0, append_osmux_support)));
-	T.start;
-	alt {
-	[] BSSAP.receive(tr_BSSAP_UNITDATA_ind(own, peer, tr_BSSMAP_ResetAck(append_osmux_support))) {
-		log("BSSMAP: Received RESET-ACK in response to RESET, we're ready to go!");
-		}
-	[] as_reset_ack(append_osmux_support);
-	[] BSSAP.receive { repeat };
-	[] T.timeout {
-		setverdict(fail, "BSSMAP: Timeout waiting for RESET-ACK after sending RESET");
-		mtc.stop;
+	while (attempts > 0) {
+		attempts := attempts - 1;
+
+		BSSAP.send(ts_BSSAP_UNITDATA_req(peer, own, ts_BSSMAP_Reset(0, append_osmux_support)));
+		T.start;
+		alt {
+		[] BSSAP.receive(tr_BSSAP_UNITDATA_ind(own, peer, tr_BSSMAP_ResetAck(append_osmux_support))) {
+			log("BSSMAP: Received RESET-ACK in response to RESET, we're ready to go!");
+			return;
+			}
+		[] as_reset_ack(append_osmux_support);
+		[] BSSAP.receive { repeat };
+		[] T.timeout {
+			continue;
+			}
 		}
 	}
+
+	setverdict(fail, "BSSMAP: Timeout waiting for RESET-ACK after sending RESET");
+	mtc.stop;
 }
 
 private function f_bssap_l3_is_rr(PDU_BSSAP bssap) return boolean {
@@ -713,6 +721,7 @@ type record RanOps {
 	RanProtocol protocol,
 	RAN_Transport transport,
 	boolean use_osmux,
+	integer bssap_reset_retries,
 	/* needed for performing BSSMAP RESET */
 	SCCP_PAR_Address sccp_addr_local optional,
 	SCCP_PAR_Address sccp_addr_peer optional
diff --git a/msc/BSC_ConnectionHandler.ttcn b/msc/BSC_ConnectionHandler.ttcn
index 7b3188a12..c3426a444 100644
--- a/msc/BSC_ConnectionHandler.ttcn
+++ b/msc/BSC_ConnectionHandler.ttcn
@@ -260,6 +260,7 @@ const RanOps BSC_RanOps := {
 	protocol := RAN_PROTOCOL_BSSAP,
 	transport := BSSAP_TRANSPORT_AoIP,
 	use_osmux := false,
+	bssap_reset_retries := 1,
 	sccp_addr_local := omit,
 	sccp_addr_peer := omit
 }
diff --git a/msc/MSC_Tests.ttcn b/msc/MSC_Tests.ttcn
index dd31dafc4..2fad7b44d 100644
--- a/msc/MSC_Tests.ttcn
+++ b/msc/MSC_Tests.ttcn
@@ -140,6 +140,7 @@ modulepar {
 	charstring mp_smpp_password := "osmocom1";
 	charstring mp_mme_name := "mmec01.mmegi0001.mme.epc.mnc070.mcc901.3gppnetwork.org";
 	charstring mp_vlr_name := "vlr.example.net";
+	integer mp_bssap_reset_retries := 1;
 
 	RAN_Configurations mp_bssap_cfg := {
 		{
@@ -327,6 +328,7 @@ function f_init(integer num_bsc := 1, boolean sgsap := false, boolean gsup := tr
 		if (isbound(mp_bssap_cfg[i])) {
 			var RanOps ranops := BSC_RanOps;
 			ranops.use_osmux := osmux;
+			ranops.bssap_reset_retries := mp_bssap_reset_retries;
 			f_ran_adapter_init(g_bssap[i], mp_bssap_cfg[i], "MSC_Test_" & int2str(i), ranops);
 			f_ran_adapter_start(g_bssap[i]);
 		} else {