module SGsAP_Emulation { /* SGsAP Emulation, runs on top of SGsAP_CodecPort. It multiplexes/demultiplexes * the individual IMSIs/subscribers, so there can be separate TTCN-3 components handling * each of them. * * The SGsAP_Emulation.main() function processes SGsAP primitives from the SGsAP * socket via the SGsAP_CodecPort, and dispatches them to the per-IMSI components. * * For each new IMSI, the SgsapOps.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. * * 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. * * Inbound SGsAP messages without IMSI (such as RESET-IND/ACK) are dispatched to * the SgsapOps.unitdata_cb() callback, which is registered with an argument to the * main() function below. * * (C) 2018 by Harald Welte * 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 SGsAP_CodecPort all; import from SGsAP_CodecPort_CtrlFunct all; import from SGsAP_Types all; import from SGsAP_Templates all; import from SCTP_Templates all; import from Osmocom_Types all; import from IPL4asp_Types all; import from DNS_Helpers all; import from MobileL3_Types all; type component SGsAP_ConnHdlr { port SGsAP_Conn_PT SGsAP; /* procedure based port to register for incoming connections */ port SGsAPEM_PROC_PT SGsAP_PROC; } /* port between individual per-connection components and this dispatcher */ type port SGsAP_Conn_PT message { inout PDU_SGsAP, PDU_ML3_MS_NW, PDU_ML3_NW_MS; } with { extension "internal" }; /* global test port e.g. for non-imsi/conn specific messages */ type port SGsAP_PT message { inout PDU_SGsAP; } with { extension "internal" }; /* represents a single SGsAP Association */ type record AssociationData { SGsAP_ConnHdlr comp_ref, hexstring imsi optional }; type component SGsAP_Emulation_CT { /* Port facing to the UDP SUT */ port SGsAP_CODEC_PT SGsAP; /* All SGsAP_ConnHdlr SGsAP ports connect here * SGsAP_Emulation_CT.main needs to figure out what messages * to send where with CLIENT.send() to vc_conn */ port SGsAP_Conn_PT SGsAP_CLIENT; /* currently tracked connections */ var AssociationData SgsapAssociationTable[16]; /* pending expected CRCX */ var ExpectData SgsapExpectTable[8]; /* procedure based port to register for incoming connections */ port SGsAPEM_PROC_PT SGsAP_PROC; /* test port for unit data messages */ port SGsAP_PT SGsAP_UNIT; var charstring g_sgsap_id; var integer g_sgsap_conn_id := -1; } type function SGsAPCreateCallback(PDU_SGsAP msg, hexstring imsi, charstring id) runs on SGsAP_Emulation_CT return SGsAP_ConnHdlr; type function SGsAPUnitdataCallback(PDU_SGsAP msg) runs on SGsAP_Emulation_CT return template PDU_SGsAP; type record SGsAPOps { SGsAPCreateCallback create_cb, SGsAPUnitdataCallback unitdata_cb } type record SGsAP_conn_parameters { HostName remote_ip, PortNumber remote_sctp_port, HostName local_ip, PortNumber local_sctp_port } function tr_SGsAP_RecvFrom_R(template PDU_SGsAP msg) runs on SGsAP_Emulation_CT return template SGsAP_RecvFrom { var template SGsAP_RecvFrom mrf := { connId := g_sgsap_conn_id, remName := ?, remPort := ?, locName := ?, locPort := ?, msg := msg } return mrf; } private function f_imsi_known(hexstring imsi) runs on SGsAP_Emulation_CT return boolean { var integer i; for (i := 0; i < sizeof(SgsapAssociationTable); i := i+1) { if (SgsapAssociationTable[i].imsi == imsi) { return true; } } return false; } private function f_comp_known(SGsAP_ConnHdlr client) runs on SGsAP_Emulation_CT return boolean { var integer i; for (i := 0; i < sizeof(SgsapAssociationTable); i := i+1) { if (SgsapAssociationTable[i].comp_ref == client) { return true; } } return false; } private function f_comp_by_imsi(hexstring imsi) runs on SGsAP_Emulation_CT return SGsAP_ConnHdlr { var integer i; for (i := 0; i < sizeof(SgsapAssociationTable); i := i+1) { if (SgsapAssociationTable[i].imsi == imsi) { return SgsapAssociationTable[i].comp_ref; } } setverdict(fail, "SGsAP Association Table not found by IMSI", imsi); mtc.stop; } private function f_imsi_by_comp(SGsAP_ConnHdlr client) runs on SGsAP_Emulation_CT return hexstring { var integer i; for (i := 0; i < sizeof(SgsapAssociationTable); i := i+1) { if (SgsapAssociationTable[i].comp_ref == client) { return SgsapAssociationTable[i].imsi; } } setverdict(fail, "SGsAP Association Table not found by component ", client); mtc.stop; } private function f_imsi_table_add(SGsAP_ConnHdlr comp_ref, hexstring imsi) runs on SGsAP_Emulation_CT { var integer i; for (i := 0; i < sizeof(SgsapAssociationTable); i := i+1) { if (not isvalue(SgsapAssociationTable[i].imsi)) { SgsapAssociationTable[i].imsi := imsi; SgsapAssociationTable[i].comp_ref := comp_ref; return; } } testcase.stop("SGsAP Association Table full!"); } private function f_imsi_table_del(SGsAP_ConnHdlr comp_ref, hexstring imsi) runs on SGsAP_Emulation_CT { var integer i; for (i := 0; i < sizeof(SgsapAssociationTable); i := i+1) { if (SgsapAssociationTable[i].comp_ref == comp_ref and SgsapAssociationTable[i].imsi == imsi) { SgsapAssociationTable[i].imsi := omit; SgsapAssociationTable[i].comp_ref := null; return; } } setverdict(fail, "SGsAP Association Table: Couldn't find to-be-deleted entry!"); mtc.stop; } private function f_imsi_table_init() runs on SGsAP_Emulation_CT { for (var integer i := 0; i < sizeof(SgsapAssociationTable); i := i+1) { SgsapAssociationTable[i].comp_ref := null; SgsapAssociationTable[i].imsi := omit; } } private function f_SGsAP_get_imsi(PDU_SGsAP pdu) return template (omit) IMSI { if (ischosen(pdu.sGsAP_ALERT_ACK)) { return pdu.sGsAP_ALERT_ACK.iMSI; } else if (ischosen(pdu.sGsAP_ALERT_REJECT)) { return pdu.sGsAP_ALERT_REJECT.iMSI; } else if (ischosen(pdu.sGsAP_ALERT_REQUEST)) { return pdu.sGsAP_ALERT_REQUEST.iMSI; } else if (ischosen(pdu.sGsAP_DOWNLINK_UNITDATA)) { return pdu.sGsAP_DOWNLINK_UNITDATA.iMSI; } else if (ischosen(pdu.sGsAP_EPS_DETACH_ACK)) { return pdu.sGsAP_EPS_DETACH_ACK.iMSI; } else if (ischosen(pdu.sGsAP_EPS_DETACH_INDICATION)) { return pdu.sGsAP_EPS_DETACH_INDICATION.iMSI; } else if (ischosen(pdu.sGsAP_IMSI_DETACH_ACK)) { return pdu.sGsAP_IMSI_DETACH_ACK.iMSI; } else if (ischosen(pdu.sGsAP_IMSI_DETACH_INDICATION)) { return pdu.sGsAP_IMSI_DETACH_INDICATION.iMSI; } else if (ischosen(pdu.sGsAP_LOCATION_UPDATE_ACCEPT)) { return pdu.sGsAP_LOCATION_UPDATE_ACCEPT.iMSI; } else if (ischosen(pdu.sGsAP_LOCATION_UPDATE_REJECT)) { return pdu.sGsAP_LOCATION_UPDATE_REJECT.iMSI; } else if (ischosen(pdu.sGsAP_LOCATION_UPDATE_REQUEST)) { return pdu.sGsAP_LOCATION_UPDATE_REQUEST.iMSI; } else if (ischosen(pdu.sGsAP_MM_INFORMATION_REQUEST)) { return pdu.sGsAP_MM_INFORMATION_REQUEST.iMSI; } else if (ischosen(pdu.sGsAP_PAGING_REJECT)) { return pdu.sGsAP_PAGING_REJECT.iMSI; } else if (ischosen(pdu.sGsAP_PAGING_REQUEST)) { return pdu.sGsAP_PAGING_REQUEST.iMSI; } else if (ischosen(pdu.sGsAP_SERVICE_REQUEST)) { return pdu.sGsAP_SERVICE_REQUEST.iMSI; } else if (ischosen(pdu.sGsAP_STATUS)) { return pdu.sGsAP_STATUS.iMSI; } else if (ischosen(pdu.sGsAP_TMSI_REALLOCATION_COMPLETE)) { return pdu.sGsAP_TMSI_REALLOCATION_COMPLETE.iMSI; } else if (ischosen(pdu.sGsAP_UE_ACTIVITY_INDICATION)) { return pdu.sGsAP_UE_ACTIVITY_INDICATION.iMSI; } else if (ischosen(pdu.sGsAP_UE_UNREACHABLE)) { return pdu.sGsAP_UE_UNREACHABLE.iMSI; } else if (ischosen(pdu.sGsAP_UPLINK_UNITDATA)) { return pdu.sGsAP_UPLINK_UNITDATA.iMSI; } else if (ischosen(pdu.sGsAP_RELEASE_REQUEST)) { return pdu.sGsAP_RELEASE_REQUEST.iMSI; } else if (ischosen(pdu.sGsAP_SERVICE_ABORT_REQUEST)) { return pdu.sGsAP_SERVICE_ABORT_REQUEST.iMSI; } else if (ischosen(pdu.sGsAP_MO_CSFB_INDICATION)) { return pdu.sGsAP_MO_CSFB_INDICATION.iMSI; } return omit; } private function f_sgsap_xceive(template (value) PDU_SGsAP tx, template PDU_SGsAP rx_t := ?) runs on SGsAP_Emulation_CT return PDU_SGsAP { timer T := 10.0; var SGsAP_RecvFrom mrf; SGsAP.send(t_SGsAP_Send(g_sgsap_conn_id, tx)); alt { [] SGsAP.receive(tr_SGsAP_RecvFrom_R(rx_t)) -> value mrf { } [] SGsAP.receive(tr_SctpAssocChange) { repeat; } [] SGsAP.receive(tr_SctpPeerAddrChange) { repeat; } [] T.timeout { setverdict(fail, "Timeout waiting for ", rx_t); mtc.stop; } } return mrf.msg; } function main(SGsAPOps ops, SGsAP_conn_parameters p, charstring id) runs on SGsAP_Emulation_CT { var Result res; g_sgsap_id := id; f_imsi_table_init(); f_expect_table_init(); map(self:SGsAP, system:SGsAP_CODEC_PT); if (p.remote_sctp_port == -1) { res := SGsAP_CodecPort_CtrlFunct.f_IPL4_listen(SGsAP, p.local_ip, p.local_sctp_port, { sctp := valueof(ts_SctpTuple) }); } else { res := SGsAP_CodecPort_CtrlFunct.f_IPL4_connect(SGsAP, p.remote_ip, p.remote_sctp_port, p.local_ip, p.local_sctp_port, -1, { sctp := valueof(ts_SctpTuple) }); } if (not ispresent(res.connId)) { setverdict(fail, "Could not connect SGsAP socket, check your configuration"); mtc.stop; } g_sgsap_conn_id := res.connId; while (true) { var SGsAP_ConnHdlr vc_conn; var PDU_ML3_MS_NW l3_mo; var PDU_ML3_NW_MS l3_mt; var template IMSI imsi_t; var hexstring imsi; var SGsAP_RecvFrom mrf; var PDU_SGsAP msg; var charstring vlr_name, mme_name; alt { /* SGsAP from client */ [] SGsAP_CLIENT.receive(PDU_SGsAP:?) -> value msg sender vc_conn { /* Pass message through */ /* TODO: check which ConnectionID client has allocated + store in table? */ SGsAP.send(t_SGsAP_Send(g_sgsap_conn_id, msg)); } /* DTAP/MobileL3 from client (emulated MS): wrap in SGsAP-UL-UD and send */ [] SGsAP_CLIENT.receive(PDU_ML3_MS_NW:?) -> value l3_mo sender vc_conn { var octetstring l3_enc := enc_PDU_ML3_MS_NW(l3_mo); imsi := f_imsi_by_comp(vc_conn); msg := valueof(ts_SGsAP_UL_UD(imsi, l3_enc)); SGsAP.send(t_SGsAP_Send(g_sgsap_conn_id, msg)); } [] SGsAP_CLIENT.receive(PDU_ML3_NW_MS:?) -> value l3_mt sender vc_conn { var octetstring l3_enc := enc_PDU_ML3_NW_MS(l3_mt); imsi := f_imsi_by_comp(vc_conn); msg := valueof(ts_SGsAP_DL_UD(imsi, l3_enc)); SGsAP.send(t_SGsAP_Send(g_sgsap_conn_id, msg)); } /* DTAP/MobileL3 from MSC/VLR to MS wrapped in SGsAP-DL-UD: Extract, decode, forward */ [] SGsAP.receive(tr_SGsAP_RecvFrom_R(tr_SGsAP_DL_UD(?,?))) -> value mrf { var octetstring l3_enc := mrf.msg.sGsAP_DOWNLINK_UNITDATA.nAS_MessageContainer.nAS_MessageContainer; imsi := mrf.msg.sGsAP_DOWNLINK_UNITDATA.iMSI.iMSI.digits; vc_conn := f_comp_by_imsi(imsi); l3_mt := dec_PDU_ML3_NW_MS(l3_enc); SGsAP_CLIENT.send(l3_mt) to vc_conn; } [] SGsAP.receive(tr_SGsAP_RecvFrom_R(tr_SGsAP_UL_UD(?,?))) -> value mrf { var octetstring l3_enc := mrf.msg.sGsAP_UPLINK_UNITDATA.nAS_MessageContainer.nAS_MessageContainer; imsi := mrf.msg.sGsAP_UPLINK_UNITDATA.iMSI.iMSI.digits; l3_mo := dec_PDU_ML3_MS_NW(l3_enc); vc_conn := f_comp_by_imsi(imsi); SGsAP_CLIENT.send(l3_mo) to vc_conn; } /* any other SGsAP from MSC/VLR */ [] SGsAP.receive(tr_SGsAP_RecvFrom_R(?)) -> value mrf { imsi_t := f_SGsAP_get_imsi(mrf.msg); if (isvalue(imsi_t)) { imsi := valueof(imsi_t.iMSI.digits); if (f_imsi_known(imsi)) { vc_conn := f_comp_by_imsi(imsi); SGsAP_CLIENT.send(mrf.msg) to vc_conn; } else { vc_conn := ops.create_cb.apply(mrf.msg, imsi, id); f_imsi_table_add(vc_conn, imsi); SGsAP_CLIENT.send(mrf.msg) to vc_conn; } } else { /* message contained no IMSI; is not IMSI-oriented */ var template PDU_SGsAP resp := ops.unitdata_cb.apply(mrf.msg); if (isvalue(resp)) { SGsAP.send(t_SGsAP_Send(g_sgsap_conn_id, valueof(resp))); } } } [] SGsAP.receive(tr_SctpAssocChange) { } [] SGsAP.receive(tr_SctpPeerAddrChange) { } [] SGsAP_PROC.getcall(SGsAPEM_register:{?,?}) -> param(imsi, vc_conn) { f_create_expect(imsi, vc_conn); SGsAP_PROC.reply(SGsAPEM_register:{imsi, vc_conn}) to vc_conn; } [] SGsAP_PROC.getcall(SGsAPEM_reset_mme:{?,-}) -> param(mme_name) { var octetstring mme_enc, vlr_enc; mme_enc := f_enc_dns_hostname(mme_name); msg := f_sgsap_xceive(ts_SGsAP_RESET_IND_MME(mme_enc)); vlr_enc := msg.sGsAP_RESET_ACK.vLR_Name.name; vlr_name := f_dec_dns_hostname(vlr_enc); SGsAP_PROC.reply(SGsAPEM_reset_mme:{mme_name, vlr_name}); } [] SGsAP_PROC.getcall(SGsAPEM_reset_vlr:{?,-}) -> param(vlr_name) { var octetstring mme_enc, vlr_enc; vlr_enc := f_enc_dns_hostname(vlr_name); msg := f_sgsap_xceive(ts_SGsAP_RESET_IND_VLR(vlr_enc)); mme_enc := msg.sGsAP_RESET_ACK.mME_Name.name; mme_name := f_dec_dns_hostname(mme_enc); SGsAP_PROC.reply(SGsAPEM_reset_vlr:{vlr_name, mme_name}); } } } } /* "Expect" Handling */ type record ExpectData { hexstring imsi optional, SGsAP_ConnHdlr vc_conn } signature SGsAPEM_register(in hexstring imsi, in SGsAP_ConnHdlr hdlr); signature SGsAPEM_reset_vlr(in charstring vlr_name, out charstring mme_name); signature SGsAPEM_reset_mme(in charstring mme_name, out charstring vlr_name); type port SGsAPEM_PROC_PT procedure { inout SGsAPEM_register, SGsAPEM_reset_vlr, SGsAPEM_reset_mme; } with { extension "internal" }; /* Function that can be used as create_cb and will use the expect table */ function ExpectedCreateCallback(PDU_SGsAP msg, hexstring imsi, charstring id) runs on SGsAP_Emulation_CT return SGsAP_ConnHdlr { var SGsAP_ConnHdlr ret := null; var integer i; for (i := 0; i < sizeof(SgsapExpectTable); i := i+1) { if (not ispresent(SgsapExpectTable[i].imsi)) { continue; } if (imsi == SgsapExpectTable[i].imsi) { ret := SgsapExpectTable[i].vc_conn; /* Release this entry */ SgsapExpectTable[i].imsi := omit; SgsapExpectTable[i].vc_conn := null; log("Found Expect[", i, "] for ", msg, " handled at ", ret); return ret; } } setverdict(fail, "Couldn't find Expect for ", msg); mtc.stop; } private function f_create_expect(hexstring imsi, SGsAP_ConnHdlr hdlr) runs on SGsAP_Emulation_CT { var integer i; /* Check an entry like this is not already presnt */ for (i := 0; i < sizeof(SgsapExpectTable); i := i+1) { if (imsi == SgsapExpectTable[i].imsi) { setverdict(fail, "IMSI already present", imsi); mtc.stop; } } for (i := 0; i < sizeof(SgsapExpectTable); i := i+1) { if (not ispresent(SgsapExpectTable[i].imsi)) { SgsapExpectTable[i].imsi := imsi; SgsapExpectTable[i].vc_conn := hdlr; log("Created Expect[", i, "] for ", imsi, " to be handled at ", hdlr); return; } } testcase.stop("No space left in SgsapExpectTable") } /* client/conn_hdlr side function to use procedure port to create expect in emulation */ function f_create_sgsap_expect(hexstring imsi) runs on SGsAP_ConnHdlr { SGsAP_PROC.call(SGsAPEM_register:{imsi, self}) { [] SGsAP_PROC.getreply(SGsAPEM_register:{?,?}) {}; } } /* client/conn_hdlr side function to use procedure port to send RESET from emulated MME */ function f_sgsap_reset_mme(charstring mme_name) runs on SGsAP_ConnHdlr return charstring { var charstring vlr_name; SGsAP_PROC.call(SGsAPEM_reset_mme:{mme_name, -}) { [] SGsAP_PROC.getreply(SGsAPEM_reset_mme:{mme_name,?}) -> param(vlr_name) { return vlr_name; }; } } /* client/conn_hdlr side function to use procedure port to send RESET from emulated VLR */ function f_sgsap_reset_vlr(charstring vlr_name) runs on SGsAP_ConnHdlr return charstring { var charstring mme_name; SGsAP_PROC.call(SGsAPEM_reset_vlr:{vlr_name, -}) { [] SGsAP_PROC.getreply(SGsAPEM_reset_vlr:{vlr_name,?}) -> param(mme_name) { return mme_name; }; } } private function f_expect_table_init() runs on SGsAP_Emulation_CT { var integer i; for (i := 0; i < sizeof(SgsapExpectTable); i := i + 1) { SgsapExpectTable[i].imsi := omit; } } function DummyUnitdataCallback(PDU_SGsAP msg) runs on SGsAP_Emulation_CT return template PDU_SGsAP { log("Ignoring SGsAP ", msg); return omit; } }