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module BSC_MS_ConnectionHandler {
/* (C) 2017-2019 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 SCCPasp_Types all;
import from BSSAP_Types all;
import from BSSAP_CodecPort all;
import from RAN_Emulation all;
import from BSSMAP_Templates all;
import from MobileL3_Types all;
import from MobileL3_CommonIE_Types all;
import from L3_Templates all;
import from MGCP_Types all;
import from MGCP_Templates all;
import from SDP_Types all;
type function void_fn_bsc_ms(charstring id) runs on BSC_MS_ConnHdlr;
/* this component represents a single subscriber connection at the MSC.
* There is a 1:1 mapping between SCCP connections and RAN_ConnHdlr components.
* We inherit all component variables, ports, functions, ... from RAN_ConnHdlr */
type component BSC_MS_ConnHdlr extends RAN_ConnHdlr {
/* SCCP Connecction Identifier for the underlying SCCP connection */
var integer g_sccp_conn_id;
var MgcpConnectionId g_mgcp_conn_id;
var SDP_Message g_sdp;
var BSC_State g_state;
var BSC_MS_TestHdlrParams g_pars;
}
type record BSC_MS_TestHdlrParams {
SCCP_PAR_Address sccp_addr_own,
SCCP_PAR_Address sccp_addr_remote,
boolean use_osmux
};
/* Callback function from general RAN_Emulation whenever a new incoming
* SCCP connection arrivces. Must create + start a new component */
private function CreateCallback(BSSAP_N_CONNECT_ind conn_ind, charstring id)
runs on RAN_Emulation_CT return RAN_ConnHdlr {
log("Incoming SCCP Connection on BSC ?!?");
self.stop;
}
/* Callback function from general RAN_Emulation whenever a connectionless
* BSSMAP message arrives. Can retunr a PDU_BSSAP that should be sent in return */
private function UnitdataCallback(PDU_BSSAP bssap)
runs on RAN_Emulation_CT return template PDU_BSSAP {
var template PDU_BSSAP resp := omit;
if (match(bssap, tr_BSSMAP_Reset)) {
resp := ts_BSSMAP_ResetAck;
}
return resp;
}
const RanOps BSC_MS_RanOps := {
create_cb := refers(CreateCallback),
unitdata_cb := refers(UnitdataCallback),
decode_dtap := false,
role_ms := true,
protocol := RAN_PROTOCOL_BSSAP,
transport := BSSAP_TRANSPORT_AoIP,
use_osmux := false,
sccp_addr_local := omit,
sccp_addr_peer := omit
}
function f_gen_cl3(hexstring imsi) return PDU_BSSAP {
var MobileIdentityLV mi := valueof(ts_MI_IMSI_LV(imsi));
var PDU_ML3_MS_NW l3 := valueof(ts_CM_SERV_REQ(CM_TYPE_MO_CALL, mi));
var BSSMAP_IE_CellIdentifier cell_id := valueof(ts_CellID_LAC_CI(23, 42));
var PDU_BSSAP bssap := valueof(ts_BSSMAP_ComplL3(cell_id, enc_PDU_ML3_MS_NW(l3)));
return bssap;
}
type enumerated BSC_State {
BSC_STATE_NONE,
BSC_STATE_WAIT_ASS_REQ,
BSC_STATE_WAIT_CRCX,
BSC_STATE_WAIT_MDCX,
BSC_STATE_WAIT_MDCX2,
BSC_STATE_WAIT_CLEAR_CMD,
BSC_STATE_WAIT_DLCX,
BSC_STATE_WAIT_DISC_IND
}
/* main function processing various incoming events */
function bsc_ms_establish_fully(charstring id)
runs on BSC_MS_ConnHdlr {
var PDU_BSSAP bssap;
var MgcpCommand mgcp_cmd;
var template MgcpResponse mgcp_resp;
var MgcpOsmuxCID osmux_cid;
log("Starting main of BSC_MS_ConnHdlr");
g_mgcp_conn_id := f_mgcp_alloc_conn_id();
/* generate and send the Complete Layer3 Info */
bssap := f_gen_cl3('901770123456789'H);
var BSSAP_Conn_Req creq := {
addr_peer := g_pars.sccp_addr_remote,
addr_own := g_pars.sccp_addr_own,
bssap := bssap
}
g_state := BSC_STATE_WAIT_ASS_REQ;
BSSAP.send(creq);
while (true) {
alt {
/* new SCCP-level connection indication from BSC */
[g_state == BSC_STATE_WAIT_ASS_REQ] BSSAP.receive(tr_BSSMAP_AssignmentReq) -> value bssap {
/* FIXME: Read CIC */
/* respond with ASSIGNMENT COMPL */
g_state := BSC_STATE_WAIT_CRCX;
BSSAP.send(ts_BSSMAP_AssignmentComplete(bssap.pdu.bssmap.assignmentRequest.circuitIdentityCode));
}
/* CRCX -> OK */
[g_state == BSC_STATE_WAIT_CRCX] BSSAP.receive(tr_CRCX) -> value mgcp_cmd {
/* FIXME: proper SDP parameters */
g_sdp := valueof(ts_SDP("127.0.0.1", "127.0.0.1", "foo", "21", 1000, { "98" },
{ valueof(ts_SDP_rtpmap(98, "AMR/8000")),
valueof(ts_SDP_ptime(20)) }));
/* respond with CRCX_ACK */
g_state := BSC_STATE_WAIT_MDCX;
if (g_pars.use_osmux != f_MgcpCmd_contains_par(mgcp_cmd, "X-OSMUX")) {
setverdict(fail, log2str("Received Osmux CID presence doesn't match presence expectancy (", g_pars.use_osmux, ")"));
self.stop;
}
if (g_pars.use_osmux) {
osmux_cid := f_MgcpCmd_extract_osmux_cid(mgcp_cmd);
mgcp_resp := ts_CRCX_ACK_osmux(mgcp_cmd.line.trans_id, g_mgcp_conn_id, osmux_cid, g_sdp);
} else {
mgcp_resp := ts_CRCX_ACK(mgcp_cmd.line.trans_id, g_mgcp_conn_id, g_sdp);
}
BSSAP.send(valueof(mgcp_resp));
}
/* MDCX -> OK */
[g_state == BSC_STATE_WAIT_MDCX] BSSAP.receive(tr_MDCX) -> value mgcp_cmd {
/* FIXME: verify if local part of endpoint name matches CIC */
/* respond with MDCX_ACK */
g_state := BSC_STATE_WAIT_MDCX2;
BSSAP.send(ts_MDCX_ACK(mgcp_cmd.line.trans_id, g_mgcp_conn_id, g_sdp));
}
/* MDCX -> OK */
[g_state == BSC_STATE_WAIT_MDCX2] BSSAP.receive(tr_MDCX) -> value mgcp_cmd {
/* FIXME: verify if local part of endpoint name matches CIC */
/* respond with MDCX_ACK */
g_state := BSC_STATE_WAIT_CLEAR_CMD;
BSSAP.send(ts_MDCX_ACK(mgcp_cmd.line.trans_id, g_mgcp_conn_id, g_sdp));
}
/* CLEAR COMMAND from MSC; respond with CLEAR COMPLETE) */
[g_state == BSC_STATE_WAIT_CLEAR_CMD] BSSAP.receive(tr_BSSMAP_ClearCommand) -> value bssap {
g_state := BSC_STATE_WAIT_DLCX;
BSSAP.send(ts_BSSMAP_ClearComplete);
}
/* DLCX -> OK */
[g_state == BSC_STATE_WAIT_DLCX] BSSAP.receive(tr_DLCX) -> value mgcp_cmd {
/* FIXME: verify if local part of endpoint name matches CIC */
g_state := BSC_STATE_WAIT_DISC_IND;
BSSAP.send(ts_DLCX_ACK(mgcp_cmd.line.trans_id, g_mgcp_conn_id));
}
[] BSSAP.receive(tr_BSSAP_DTAP) -> value bssap {
/* FIXME: verify if local part of endpoint name matches CIC */
var PDU_ML3_MS_NW l3 := dec_PDU_ML3_MS_NW(bssap.pdu.dtap);
log("Unhandled DTAP ", l3);
}
[g_state == BSC_STATE_WAIT_DISC_IND] BSSAP.receive(RAN_Conn_Prim:MSC_CONN_PRIM_DISC_IND) {
setverdict(pass);
self.stop;
}
[] BSSAP.receive(RAN_Conn_Prim:MSC_CONN_PRIM_CONF_IND) {
}
/* disconnect in invalid state */
[] BSSAP.receive(RAN_Conn_Prim:MSC_CONN_PRIM_DISC_IND) {
setverdict(fail);
self.stop;
}
[] BSSAP.receive(PDU_BSSAP:?) -> value bssap {
log("Received unhandled SCCP-CO: ", bssap);
}
}
}
}
function bsc_ms_do_nothing(charstring id)
runs on BSC_MS_ConnHdlr {
}
}
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