[M] Change in osmo-ttcn3-hacks[master]: smf,pgw: Fix missing s6b STR handling during release of s2b sessions - gerrit-log

30 Sep 2026

pespin has submitted this change. ( https://gerrit.osmocom.org/c/osmo-ttcn3-hacks/+/43740?usp=email )
Change subject: smf,pgw: Fix missing s6b STR handling during release of s2b sessions
......................................................................
smf,pgw: Fix missing s6b STR handling during release of s2b sessions
Sesions created over s2b (EPDG) also create a session on the AAA over
s6b. When  the s2b session is released, a Diameter STR message is sent
towards the AAA, which should answer with STA so that the session is
properly terminated.
Change-Id: I9bc54205eaa3b26a5ec9a3666172ee35d3b98b0e
---
M library/DIAMETER_ts29_273_Templates.ttcn
M pgw/PGW_Session_CT.ttcn
M pgw/PGW_Tests.ttcn
M smf/SMF_Session_CT_4G.ttcn
M smf/SMF_Tests.ttcn
5 files changed, 186 insertions(+), 18 deletions(-)
Approvals:
  pespin: Looks good to me, approved
  fixeria: Looks good to me, but someone else must approve
  Jenkins Builder: Verified

diff --git a/library/DIAMETER_ts29_273_Templates.ttcn b/library/DIAMETER_ts29_273_Templates.ttcn
index a9f1769..d3915b0 100644
--- a/library/DIAMETER_ts29_273_Templates.ttcn
+++ b/library/DIAMETER_ts29_273_Templates.ttcn
@@ -505,6 +505,32 @@
/* TS 29.273 9.2.2.3.1 Session-Termination-Request (STR) Command,
   * Table 9.1.2.3.1/1: S6b Session Termination Request (STR), based on RFC 6733 8.4.1 */
+template (present) PDU_DIAMETER
+tr_DIA_S6b_STR(template (present) hexstring imsi := ?,
+	       template (present) BASE_NONE_Termination_Cause term_cause := ?,
+	       template (present) octetstring sess_id := ?,
+	       template (present) charstring orig_host := ?,
+	       template (present) charstring orig_realm := ?,
+	       template (present) charstring dest_realm := ?,
+	       template (present) UINT32 hbh_id := ?,
+	       template (present) UINT32 ete_id := ?) :=
+	tr_DIAMETER(flags := '1???????'B,
+		    cmd_code := Session_Termination,
+		    app_id := int2oct(c_DIAMETER_3GPP_S6b_AID, 4),
+		    hbh_id := hbh_id,
+		    ete_id := ete_id,
+		    avps := superset(
+			tr_AVP_SessionId(sess_id),
+			/* Optional: DRMP */
+			tr_AVP_AuthAppId(int2oct(c_DIAMETER_3GPP_S6b_AID, 4)),
+			tr_AVP_OriginHost(orig_host),
+			tr_AVP_OriginRealm(orig_realm),
+			tr_AVP_DestinationRealm(dest_realm),
+			tr_AVP_TerminationCause(term_cause),
+			tr_AVP_UserNameImsi(imsi)
+			/* Optional: OC-Supported-Features */
+	));
+
 template (value) PDU_DIAMETER
 ts_DIA_S6b_STR(template (value) hexstring imsi,
           template (value) BASE_NONE_Termination_Cause term_cause := DIAMETER_LOGOUT,
@@ -554,6 +580,28 @@
    		/* Lots other Optional */
    ));
+template (value) PDU_DIAMETER
+ts_DIA_S6b_STA(template (value) DIAMETER_Resultcode res_code := DIAMETER_SUCCESS,
+	       template (value) octetstring sess_id := c_def_sess_id,
+	       template (value) charstring orig_host := "aaa.localdomain",
+	       template (value) charstring orig_realm := "localdomain",
+	       template (value) charstring dest_realm := "localdomain",
+	       template (value) UINT32 hbh_id := '00000000'O,
+	       template (value) UINT32 ete_id := '00000000'O) :=
+	ts_DIAMETER(flags := '01000000'B,
+		    cmd_code := Session_Termination,
+		    app_id := int2oct(c_DIAMETER_3GPP_S6b_AID, 4),
+		    hbh_id := hbh_id,
+		    ete_id := ete_id,
+		    avps := {
+			ts_AVP_SessionId(sess_id),
+			/* Optional: DRMP */
+			ts_AVP_ResultCode(res_code),
+			ts_AVP_ResultCode(res_code),
+			ts_AVP_OriginHost(orig_host),
+			ts_AVP_OriginRealm(orig_realm)
+			/* Lots other Optional */
+	});
/* TS 29.273 9.2.2.4.1 Abort-Session-Request (ASR) */
 template (present) PDU_DIAMETER
@@ -697,4 +745,29 @@
    return tx_dia;
 }
+/* generate a send template successful answer based on received STR */
+function f_ts_DIA_S6b_STA(PDU_DIAMETER rx_s6b,
+			  template (value) DIAMETER_Resultcode res_code := DIAMETER_SUCCESS,
+			  template (value) charstring orig_host := "aaa.localdomain",
+			  template (value) charstring orig_realm := "localdomain",
+			  template (value) charstring dest_realm := "localdomain")
+return template (value) PDU_DIAMETER
+{
+	var template (value) PDU_DIAMETER tx_dia;
+	var template (omit) AVP avp;
+	var octetstring sess_id;
+
+	avp := f_DIAMETER_get_avp(rx_s6b, c_AVP_Code_BASE_NONE_Session_Id);
+	sess_id := valueof(avp.avp_data.avp_BASE_NONE_Session_Id);
+
+	tx_dia := ts_DIA_S6b_STA(res_code,
+				 sess_id,
+				 orig_host,
+				 orig_realm,
+				 dest_realm,
+				 rx_s6b.hop_by_hop_id,
+				 rx_s6b.end_to_end_id);
+	return tx_dia;
+}
+
 }
diff --git a/pgw/PGW_Session_CT.ttcn b/pgw/PGW_Session_CT.ttcn
index 3de8d54..74aadfb 100644
--- a/pgw/PGW_Session_CT.ttcn
+++ b/pgw/PGW_Session_CT.ttcn
@@ -173,6 +173,24 @@
    }
 }
+private altstep as_DIA_S6b_STR() runs on PGW_Session_CT {
+	var PDU_DIAMETER rx_dia;
+	[] DIAMETER[DIA_S6b].receive(tr_DIA_S6b_STR()) -> value rx_dia {
+		var template (value) PDU_DIAMETER tx_dia;
+		tx_dia := f_ts_DIA_S6b_STA(rx_dia,
+					   DIAMETER_SUCCESS,
+					   "aaa." & mp_diam_realm,
+					   mp_diam_realm,
+					   mp_diam_realm);
+		DIAMETER[DIA_S6b].send(tx_dia);
+		setverdict(pass);
+	}
+	[] DIAMETER[DIA_S6b].receive(PDU_DIAMETER:?) -> value rx_dia {
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail,
+					log2str("Received unexpected DIAMETER ", rx_dia));
+	}
+}
+
 /* Gx emulation (PCRF)*/
 altstep as_DIA_Gx_CCR(DCC_NONE_CC_Request_Type req_type) runs on PGW_Session_CT {
    var PDU_DIAMETER rx_dia;
@@ -467,18 +485,21 @@
 }
/* delete the session from the PGW */
-function f_delete_session(template (omit) GTP2C_Cause tx_cause := omit,
+function f_delete_session(template (value) FullyQualifiedTEID fteid_c_ie,
+			  template (omit) GTP2C_Cause tx_cause := omit,
    		  template (present) GTP2C_Cause exp_cause,
-			  boolean expect_diameter := true) runs on PGW_Session_CT {
-	var template (value) FullyQualifiedTEID fteid_c_ie
-	fteid_c_ie := ts_GTP2C_FTEID(FTEID_IF_S5S8_SGW_GTPC, g_pars.teic_local, 0,
-					f_inet_addr(mp_local_hostname_c), omit);
+			  boolean expect_diameter := true)
+runs on PGW_Session_CT {
+
    var template PDU_GTPCv2 g2c :=
    	ts_GTP2C_DeleteSessionReq(d_teid := g_pars.teic_remote, cause := tx_cause,
    				  sender_fteid := fteid_c_ie,
    				  teid_list := {}, bearer_id := g_pars.bearer.ebi);
GTP2.send(g2c);
+	if (is_s2b_iface() and DIAMETER[DIA_S6b].checkstate("Connected") and expect_diameter) {
+		as_DIA_S6b_STR();
+	}
    if (DIAMETER[DIA_Gx].checkstate("Connected") and expect_diameter) {
    	as_DIA_Gx_CCR(TERMINATION_REQUEST);
    }
@@ -511,6 +532,28 @@
    }
 }
+function f_s5s8_delete_session(template (omit) GTP2C_Cause tx_cause := omit,
+			       template (present) GTP2C_Cause exp_cause,
+			       boolean expect_diameter := true)
+runs on PGW_Session_CT {
+	var template (value) FullyQualifiedTEID fteid_c_ie;
+
+	fteid_c_ie := ts_GTP2C_FTEID(FTEID_IF_S5S8_SGW_GTPC, g_pars.teic_local, 0,
+				     f_inet_addr(mp_local_hostname_c), omit);
+	f_delete_session(fteid_c_ie, tx_cause, exp_cause, expect_diameter);
+}
+
+function f_s2b_delete_session(template (omit) GTP2C_Cause tx_cause := omit,
+			      template (present) GTP2C_Cause exp_cause,
+			      boolean expect_diameter := true)
+runs on PGW_Session_CT {
+	var template (value) FullyQualifiedTEID fteid_c_ie;
+
+	fteid_c_ie := ts_GTP2C_FTEID(FTEID_IF_S2b_ePDG_GTPC, g_pars.teic_local, 0,
+				     f_inet_addr(mp_local_hostname_c), omit);
+
+	f_delete_session(fteid_c_ie, tx_cause, exp_cause, expect_diameter);
+}
private function f_run_prog_init(charstring command) runs on PGW_Session_CT return UECUPS_StartProgram
 {
diff --git a/pgw/PGW_Tests.ttcn b/pgw/PGW_Tests.ttcn
index bd95090..ba660dd 100644
--- a/pgw/PGW_Tests.ttcn
+++ b/pgw/PGW_Tests.ttcn
@@ -375,7 +375,7 @@
 /* create a session, then delete it again */
 private function f_TC_createSession_deleteSession() runs on PGW_Session_CT {
    f_s5s8_create_session();
-	f_delete_session(omit, Request_accepted);
+	f_s5s8_delete_session(omit, Request_accepted);
    setverdict(pass);
 }
 testcase TC_createSession_deleteSession() runs on PGW_Test_CT {
@@ -389,7 +389,7 @@
 /* send a DeleteSessionReq for an unknown/invalid TEID */
 private function f_TC_deleteSession_unknown() runs on PGW_Session_CT {
    g_pars.teic_remote := f_rnd_octstring(4);
-	f_delete_session(omit, Context_Not_Found, false);
+	f_s5s8_delete_session(omit, Context_Not_Found, false);
    setverdict(pass);
 }
 testcase TC_deleteSession_unknown() runs on PGW_Test_CT {
@@ -420,7 +420,7 @@
    as_DIA_Gy_CCR(UPDATE_REQUEST);
    f_validate_gy_cc_report(g_rx_gy, VALIDITY_TIME, (3..4), ?, ?);
-	f_delete_session(omit, Request_accepted);
+	f_s5s8_delete_session(omit, Request_accepted);
    f_validate_gy_cc_report(g_rx_gy, FINAL, (0..1), 0, 0);
    setverdict(pass);
 }
@@ -466,6 +466,7 @@
    var template (omit) APCO apco := omit;
    var template APCO exp_apco := omit;
    f_s2b_create_session(apco, exp_apco);
+	f_s2b_delete_session(omit, Request_accepted);
    setverdict(pass);
 }
 testcase TC_s2b_createSession_v4_noapco() runs on PGW_Test_CT {
@@ -487,6 +488,7 @@
    					 *, /* open5gs-smfd can contain several DNS servers */
    					 tr_GTP2C_PCO_P_PCSCF_IPv4(?)});
    f_s2b_create_session(apco, exp_apco);
+	f_s2b_delete_session(omit, Request_accepted);
    setverdict(pass);
 }
 testcase TC_s2b_createSession_v4_apco() runs on PGW_Test_CT {
diff --git a/smf/SMF_Session_CT_4G.ttcn b/smf/SMF_Session_CT_4G.ttcn
index 9e84218..ba230cb 100644
--- a/smf/SMF_Session_CT_4G.ttcn
+++ b/smf/SMF_Session_CT_4G.ttcn
@@ -75,6 +75,24 @@
    }
 }
+private altstep as_DIA_S6b_STR() runs on SMF_Session_CT {
+	var PDU_DIAMETER rx_dia;
+	[] DIAMETER[DIA_S6b].receive(tr_DIA_S6b_STR()) -> value rx_dia {
+		var template (value) PDU_DIAMETER tx_dia;
+		tx_dia := f_ts_DIA_S6b_STA(rx_dia,
+					   DIAMETER_SUCCESS,
+					   "aaa." & mp_diam_realm,
+					   mp_diam_realm,
+					   mp_diam_realm);
+		DIAMETER[DIA_S6b].send(tx_dia);
+		setverdict(pass);
+	}
+	[] DIAMETER[DIA_S6b].receive(PDU_DIAMETER:?) -> value rx_dia {
+		Misc_Helpers.f_shutdown(__BFILE__, __LINE__, fail,
+					log2str("Received unexpected DIAMETER ", rx_dia));
+	}
+}
+
 /* Gx emulation (PCRF)*/
 altstep as_DIA_Gx_CCR(DCC_NONE_CC_Request_Type req_type) runs on SMF_Session_CT {
    var PDU_DIAMETER rx_dia;
@@ -361,13 +379,13 @@
 }
/* delete the session from the SMF */
-function f_delete_session(template (omit) GTP2C_Cause tx_cause := omit,
-			  template (present) GTP2C_Cause exp_cause,
-			  boolean expect_pfcp := true,
-			  boolean expect_diameter := true) runs on SMF_Session_CT {
-	var template (value) FullyQualifiedTEID fteid_c_ie
-	fteid_c_ie := ts_GTP2C_FTEID(FTEID_IF_S5S8_SGW_GTPC, g_pars.teic_local, 0,
-					f_inet_addr(mp_local_hostname_c), omit);
+private function f_delete_session(template (value) FullyQualifiedTEID fteid_c_ie,
+				  template (omit) GTP2C_Cause tx_cause := omit,
+				  template (present) GTP2C_Cause exp_cause,
+				  boolean expect_pfcp := true,
+				  boolean expect_diameter := true)
+runs on SMF_Session_CT {
+
    var template PDU_GTPCv2 g2c :=
    	ts_GTP2C_DeleteSessionReq(d_teid := g_pars.teic_remote, cause := tx_cause,
    				  sender_fteid := fteid_c_ie,
@@ -379,6 +397,10 @@
    	as_pfcp_sess_del_req();
    }
+	if (is_s2b_iface() and DIAMETER[DIA_S6b].checkstate("Connected") and expect_diameter) {
+		as_DIA_S6b_STR();
+	}
+
    if (DIAMETER[DIA_Gx].checkstate("Connected") and expect_diameter) {
    	as_DIA_Gx_CCR(TERMINATION_REQUEST);
    }
@@ -400,4 +422,30 @@
    }
 }
+function f_s5s8_delete_session(template (omit) GTP2C_Cause tx_cause := omit,
+			       template (present) GTP2C_Cause exp_cause,
+			       boolean expect_pfcp := true,
+			       boolean expect_diameter := true)
+runs on SMF_Session_CT {
+	var template (value) FullyQualifiedTEID fteid_c_ie;
+
+	fteid_c_ie := ts_GTP2C_FTEID(FTEID_IF_S5S8_SGW_GTPC, g_pars.teic_local, 0,
+				     f_inet_addr(mp_local_hostname_c), omit);
+
+	f_delete_session(fteid_c_ie, tx_cause, exp_cause, expect_pfcp, expect_diameter);
+}
+
+function f_s2b_delete_session(template (omit) GTP2C_Cause tx_cause := omit,
+			      template (present) GTP2C_Cause exp_cause,
+			      boolean expect_pfcp := true,
+			      boolean expect_diameter := true)
+runs on SMF_Session_CT {
+	var template (value) FullyQualifiedTEID fteid_c_ie;
+
+	fteid_c_ie := ts_GTP2C_FTEID(FTEID_IF_S2b_ePDG_GTPC, g_pars.teic_local, 0,
+				     f_inet_addr(mp_local_hostname_c), omit);
+
+	f_delete_session(fteid_c_ie, tx_cause, exp_cause, expect_pfcp, expect_diameter);
+}
+
 }
diff --git a/smf/SMF_Tests.ttcn b/smf/SMF_Tests.ttcn
index 609756a..4501520 100644
--- a/smf/SMF_Tests.ttcn
+++ b/smf/SMF_Tests.ttcn
@@ -337,7 +337,7 @@
 /* create an IPv4 session, then delete it again */
 private function f_TC_createSession_deleteSession() runs on SMF_Session_CT {
    f_s5s8_create_session();
-	f_delete_session(omit, Request_accepted);
+	f_s5s8_delete_session(omit, Request_accepted);
    setverdict(pass);
 }
 testcase TC_createSession_deleteSession() runs on SMF_Test_CT {
@@ -399,7 +399,7 @@
 /* send a DeleteSessionReq for an unknown/invalid TEID */
 private function f_TC_deleteSession_unknown() runs on SMF_Session_CT {
    g_pars.teic_remote := f_rnd_octstring(4);
-	f_delete_session(omit, Context_Not_Found, false, false);
+	f_s5s8_delete_session(omit, Context_Not_Found, false, false);
    setverdict(pass);
 }
 testcase TC_deleteSession_unknown() runs on SMF_Test_CT {
@@ -451,7 +451,7 @@
    /* SMF updates new Volume quota obtained from OCS on UPF: */
    as_pfcp_sess_mod_req();
-	f_delete_session(omit, Request_accepted);
+	f_s5s8_delete_session(omit, Request_accepted);
    f_validate_gy_cc_report(g_rx_gy, FINAL, (0..1), 0, 0);
    setverdict(pass);
 }
@@ -506,6 +506,7 @@
    var template (omit) APCO apco := omit;
    var template APCO exp_apco := omit;
    f_s2b_create_session(apco, exp_apco);
+	f_s2b_delete_session(omit, Request_accepted);
    setverdict(pass);
 }
 testcase TC_s2b_createSession_v4_noapco() runs on SMF_Test_CT {
@@ -525,6 +526,7 @@
    					 *, /* open5gs-smfd can contain several DNS servers */
    					 tr_GTP2C_PCO_P_PCSCF_IPv4(?)});
    f_s2b_create_session(apco, exp_apco);
+	f_s2b_delete_session(omit, Request_accepted);
    setverdict(pass);
 }
 testcase TC_s2b_createSession_v4_apco() runs on SMF_Test_CT {
-- 
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Gerrit-MessageType: merged
Gerrit-Project: osmo-ttcn3-hacks
Gerrit-Branch: master
Gerrit-Change-Id: I9bc54205eaa3b26a5ec9a3666172ee35d3b98b0e
Gerrit-Change-Number: 43740
Gerrit-PatchSet: 2
Gerrit-Owner: pespin pespin@sysmocom.de
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria vyanitskiy@sysmocom.de
Gerrit-Reviewer: pespin pespin@sysmocom.de



    