S1AP_Emulation: add missing create_cb
At the moment we do not have a default implementation for the create_cb.
The create_cb is called to resolve the vc_conn to which a subscriber
communication belongs in case it is not found in the S1apAssociationTable,
then it is resolved from an S1apExpectTable instead.
The current implementation uses the IMSI as key to resolve the vc_conn
from the S1apExpectTable, this might not work since in S1AP the UE
context is identfied by an MME_UE_S1AP_ID / ENB_UE_S1AP_ID pair.
Related: OS#5760
Change-Id: I758e7c8d8cc445cf18acdd7a25dcde8846fd84e5
diff --git a/library/S1AP_Emulation.ttcn b/library/S1AP_Emulation.ttcn
index 1f23b66..6221bf8 100644
--- a/library/S1AP_Emulation.ttcn
+++ b/library/S1AP_Emulation.ttcn
@@ -1,22 +1,25 @@
module S1AP_Emulation {
-/* S1AP Emulation, runs on top of S1AP_CodecPort. It multiplexes/demultiplexes
- * the individual IMSIs/subscribers, so there can be separate TTCN-3 components handling
- * each of them.
+/* S1AP Emulation, runs on top of S1AP_CodecPort. It multiplexes/demultiplexes
+ * the individual subscribers by their UE association (MME_UE_S1AP_ID/
+ * ENB_UE_S1AP_ID identifiers), so there can be separate TTCN-3 components
+ * handling each of them.
*
* The S1AP_Emulation.main() function processes S1AP primitives from the S1AP
- * socket via the S1AP_CodecPort, and dispatches them to the per-IMSI components.
+ * socket via the S1AP_CodecPort, and dispatches them to the per-subscriber
+ * components.
*
- * For each new IMSI, the S1apOps.create_cb() is called. It can create
- * or resolve a TTCN-3 component, and returns a component reference to which that IMSI
- * is routed/dispatched.
+ * For each new subscruber, the S1apOps.create_cb() is called. It can create
+ * or resolve a TTCN-3 component, and returns a component reference to which
+ * that subscriber traffic is routed/dispatched.
*
- * If a pre-existing component wants to register to handle a future inbound IMSI, it can
- * do so by registering an "expect" with the expected IMSI.
+ * If a pre-existing component wants to register to handle a future inbound UE
+ * association, it can do so by registering an "expect" with the expected
+ * MME_UE_S1AP_ID/ENB_UE_S1AP_ID identifiers.
*
- * Inbound non-UE related S1AP messages (such as RESET, SETUP, OVERLOAD) are dispatched to
- * the S1apOps.unitdata_cb() callback, which is registered with an argument to the
- * main() function below.
+ * Inbound non-UE related S1AP messages (such as RESET, SETUP, OVERLOAD) are
+ * dispatched to the S1apOps.unitdata_cb() callback, which is registered with
+ * an argument to the main() function below.
*
* (C) 2019 by Harald Welte <laforge@gnumonks.org>
* All rights reserved.
@@ -393,7 +396,8 @@
while (true) {
var S1AP_ConnHdlr vc_conn;
var PDU_NAS_EPS nas;
- var hexstring imsi;
+ var MME_UE_S1AP_ID mme_id;
+ var ENB_UE_S1AP_ID enb_id;
var S1AP_RecvFrom mrf;
var S1AP_PDU msg;
var S1APEM_Config s1cfg;
@@ -460,7 +464,7 @@
if (f_s1ap_ids_known(mme_ue_id, enb_ue_id)) {
/* if yes, dispatch to the ConnHdlr for this Ue-Connection */
var template (omit) octetstring nas_enc;
- var integer assoc_id := f_assoc_id_by_s1ap_ids(mme_ue_id, enb_ue_id);
+ var integer assoc_id := f_assoc_id_by_s1ap_ids(mme_ue_id, enb_ue_id);
vc_conn := S1apAssociationTable[assoc_id].comp_ref;
nas_enc := f_S1AP_get_NAS_PDU(mrf.msg);
if (isvalue(nas_enc)) {
@@ -484,9 +488,9 @@
}
[] S1AP.receive(tr_SctpAssocChange) { }
[] S1AP.receive(tr_SctpPeerAddrChange) { }
- [] S1AP_PROC.getcall(S1APEM_register:{?,?}) -> param(imsi, vc_conn) {
- f_create_expect(imsi, vc_conn);
- S1AP_PROC.reply(S1APEM_register:{imsi, vc_conn}) to vc_conn;
+ [] S1AP_PROC.getcall(S1APEM_register:{?,?,?}) -> param(mme_id, enb_id, vc_conn) {
+ f_create_expect(mme_id, enb_id, vc_conn);
+ S1AP_PROC.reply(S1APEM_register:{mme_id, enb_id, vc_conn}) to vc_conn;
}
}
@@ -496,30 +500,35 @@
/* "Expect" Handling */
type record ExpectData {
- hexstring imsi optional,
+ MME_UE_S1AP_ID mme_id optional,
+ ENB_UE_S1AP_ID enb_id optional,
S1AP_ConnHdlr vc_conn
}
-signature S1APEM_register(in hexstring imsi, in S1AP_ConnHdlr hdlr);
+signature S1APEM_register(in MME_UE_S1AP_ID mme_id, in ENB_UE_S1AP_ID enb_id, in S1AP_ConnHdlr hdlr);
type port S1APEM_PROC_PT procedure {
inout S1APEM_register;
} with { extension "internal" };
/* Function that can be used as create_cb and will use the expect table */
-function ExpectedCreateCallback(S1AP_PDU msg, hexstring imsi, charstring id)
+function ExpectedCreateCallback(S1AP_PDU msg,
+ template (omit) MME_UE_S1AP_ID mme_id,
+ template (omit) ENB_UE_S1AP_ID enb_id, charstring id)
runs on S1AP_Emulation_CT return S1AP_ConnHdlr {
var S1AP_ConnHdlr ret := null;
var integer i;
for (i := 0; i < sizeof(S1apExpectTable); i := i+1) {
- if (not ispresent(S1apExpectTable[i].imsi)) {
+ if (not ispresent(S1apExpectTable[i].mme_id) and not ispresent(S1apExpectTable[i].enb_id)) {
continue;
}
- if (imsi == S1apExpectTable[i].imsi) {
+
+ if (valueof(mme_id) == S1apExpectTable[i].mme_id and valueof(enb_id) == S1apExpectTable[i].enb_id) {
ret := S1apExpectTable[i].vc_conn;
/* Release this entry */
- S1apExpectTable[i].imsi := omit;
+ S1apExpectTable[i].mme_id := omit;
+ S1apExpectTable[i].enb_id := omit;
S1apExpectTable[i].vc_conn := null;
log("Found Expect[", i, "] for ", msg, " handled at ", ret);
return ret;
@@ -529,22 +538,28 @@
mtc.stop;
}
-private function f_create_expect(hexstring imsi, S1AP_ConnHdlr hdlr)
+private function f_create_expect(template (omit) MME_UE_S1AP_ID mme_id,
+ template (omit) ENB_UE_S1AP_ID enb_id,
+ S1AP_ConnHdlr hdlr)
runs on S1AP_Emulation_CT {
var integer i;
/* Check an entry like this is not already presnt */
for (i := 0; i < sizeof(S1apExpectTable); i := i+1) {
- if (imsi == S1apExpectTable[i].imsi) {
- setverdict(fail, "IMSI already present", imsi);
+ if (not ispresent(S1apExpectTable[i].mme_id) and not ispresent(S1apExpectTable[i].enb_id)) {
+ continue;
+ }
+ if (valueof(mme_id) == S1apExpectTable[i].mme_id and valueof(enb_id) == S1apExpectTable[i].enb_id) {
+ setverdict(fail, "UE MME id / UE ENB id pair already present", mme_id, enb_id);
mtc.stop;
}
}
for (i := 0; i < sizeof(S1apExpectTable); i := i+1) {
- if (not ispresent(S1apExpectTable[i].imsi)) {
- S1apExpectTable[i].imsi := imsi;
+ if (not ispresent(S1apExpectTable[i].mme_id) and not ispresent(S1apExpectTable[i].enb_id)) {
+ S1apExpectTable[i].mme_id := valueof(mme_id);
+ S1apExpectTable[i].enb_id := valueof(enb_id);
S1apExpectTable[i].vc_conn := hdlr;
- log("Created Expect[", i, "] for ", imsi, " to be handled at ", hdlr);
+ log("Created Expect[", i, "] for UE MME id:", mme_id, ", UE ENB id:", enb_id, " to be handled at ", hdlr);
return;
}
}
@@ -552,9 +567,10 @@
}
/* client/conn_hdlr side function to use procedure port to create expect in emulation */
-function f_create_s1ap_expect(hexstring imsi) runs on S1AP_ConnHdlr {
- S1AP_PROC.call(S1APEM_register:{imsi, self}) {
- [] S1AP_PROC.getreply(S1APEM_register:{?,?}) {};
+function f_create_s1ap_expect(template (omit) MME_UE_S1AP_ID mme_id,
+ template (omit) ENB_UE_S1AP_ID enb_id) runs on S1AP_ConnHdlr {
+ S1AP_PROC.call(S1APEM_register:{mme_id, enb_id, self}) {
+ [] S1AP_PROC.getreply(S1APEM_register:{?,?,?}) {};
}
}
@@ -563,7 +579,9 @@
runs on S1AP_Emulation_CT {
var integer i;
for (i := 0; i < sizeof(S1apExpectTable); i := i + 1) {
- S1apExpectTable[i].imsi := omit;
+ S1apExpectTable[i].mme_id := omit;
+ S1apExpectTable[i].enb_id := omit;
+ S1apExpectTable[i].vc_conn := null;
}
}
diff --git a/mme/MME_Tests.ttcn b/mme/MME_Tests.ttcn
index 14965e6..a389c3d 100644
--- a/mme/MME_Tests.ttcn
+++ b/mme/MME_Tests.ttcn
@@ -141,18 +141,10 @@
return omit;
}
-friend function S1apCreateCallback(S1AP_PDU msg, template (omit) MME_UE_S1AP_ID mme_id,
- template (omit) ENB_UE_S1AP_ID enb_id, charstring id)
-runs on S1AP_Emulation_CT return S1AP_ConnHdlr
-{
- setverdict(fail, "implement this");
- mtc.stop;
-}
-
friend function f_init_one_enb(charstring id, integer num := 0) runs on MTC_CT {
id := id & "-S1AP" & int2str(num);
var S1APOps ops := {
- create_cb := refers(S1apCreateCallback),
+ create_cb := refers(S1AP_Emulation.ExpectedCreateCallback),
unitdata_cb := refers(S1apForwardUnitdataCallback)
}
var S1AP_conn_parameters pars := {