osmo-ttcn3-hacks/library/RSL_Emulation.ttcn

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module RSL_Emulation {
/* RSL Emulation, runs on top of IPA_Emulation. It multiplexes/demultiplexes
* the individual connections (logical channels), so there can be separate TTCN-3 components
* handling each of the connections.
*
* The RSL_Emulation.main() function processes RSL messages from the IPA demultiplex
* stack via the IPA_RSL_PT, and dispatches them to the per-connection components.
*
* Outbound RSL connections are initiated by sending a RSLDC_ChanRqd primitive
* to the component running the RSL_Emulation.main() function.
*
* in case we're emulating the BTS-side of RSL: We have no clue as to which particular logical
* channel the BSC may decide to activate at which point, so we have to blindly acknowledge all
* channel activations. Still, a test case might be interested in the exact assignment message to
* determine the type of activation, encryption, codec flags etc. at some later point, when it's
* clear for which transaction this activation happened. We keep this in the LastChanAct table.
*
* (C) 2017-2018 by 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.
*/
import from General_Types all;
import from Osmocom_Types all;
import from GSM_Types all;
import from GSM_RR_Types all;
import from RSL_Types all;
import from IPA_Types all;
import from IPA_Emulation all;
/* General "base class" component definition, of which specific implementations
* derive themselves by means of the "extends" feature */
type component RSL_DchanHdlr {
/* port facing up towards dedicated channel handler */
port RSL_DCHAN_PT RSL;
port RSLEM_PROC_PT RSL_PROC;
var RslChannelNr g_chan_nr;
/* second BTS / DChan during hand-over */
port RSL_DCHAN_PT RSL1;
port RSLEM_PROC_PT RSL1_PROC;
};
type record RSLDC_ChanRqd {
OCT1 ra,
GsmFrameNumber fn
};
template RSLDC_ChanRqd ts_RSLDC_ChanRqd(OCT1 ra, GsmFrameNumber fn) := {
ra := ra,
fn := fn
}
type port RSL_DCHAN_PT message {
inout RSLDC_ChanRqd, RSL_Message;
} with { extension "internal" };
type port RSL_CCHAN_PT message {
inout ASP_RSL_Unitdata, ASP_IPA_Event;
} with { extension "internal" };
signature RSLEM_register(uint8_t trx_nr, RslChannelNr chan_nr, RSL_DchanHdlr hdlr);
signature RSLEM_unregister(uint8_t trx_nr, RslChannelNr chan_nr, RSL_DchanHdlr hdlr);
signature RSLEM_suspend(boolean suspend);
signature RSLEM_get_last_act(in uint8_t trx_nr, in RslChannelNr chan_nr, out RSL_Message chan_act);
type port RSLEM_PROC_PT procedure {
inout RSLEM_register, RSLEM_unregister, RSLEM_suspend, RSLEM_get_last_act;
} with { extension "internal" };
/***********************************************************************
* Client Component for a single dedicated channel
***********************************************************************/
private function f_rx_or_fail(template RSL_Message exp_rx) runs on RSL_DchanHdlr return RSL_Message
{
var RSL_Message rx_rsl;
timer T := 10.0;
/* request a channel to be established */
T.start;
alt {
[] RSL.receive(exp_rx) -> value rx_rsl {
T.stop;
return rx_rsl;
}
[] RSL.receive {
setverdict(fail, "Unexpected RSL message on DCHAN");
mtc.stop;
}
[] T.timeout {
setverdict(fail, "Timeout waiting for RSL on DCHAN");
mtc.stop;
}
}
/* never reached */
return rx_rsl;
}
/* establish a dedicated channel using 'ra' */
function f_chan_est(OCT1 ra, octetstring est_l3, template RslLinkId link_id, GsmFrameNumber fn := 23)
runs on RSL_DchanHdlr {
var RSL_Message rx_rsl;
var GsmRrMessage rr;
/* request a channel to be established */
RSL.send(ts_RSLDC_ChanRqd(ra, fn));
/* expect immediate assignment */
rx_rsl := f_rx_or_fail(tr_RSL_IMM_ASSIGN);
rr := dec_GsmRrMessage(rx_rsl.ies[1].body.full_imm_ass_info.payload);
g_chan_nr := rr.payload.imm_ass.chan_desc.chan_nr;
RSL.send(ts_RSL_EST_IND(g_chan_nr, valueof(link_id), est_l3));
}
function f_deact_chan(RSL_Cause cause) runs on RSL_DchanHdlr
{
var RSL_Message rx_rsl;
RSL.send(ts_RSL_CONN_FAIL_IND(g_chan_nr, cause));
rx_rsl := f_rx_or_fail(tr_RSL_MsgTypeD(RSL_MT_RF_CHAN_REL));
/* FIXME RSL.send(ts_RSL_RF_CHAN_REL_ACK()) */
}
/***********************************************************************
* Main Component
***********************************************************************/
private type record ConnectionData {
/* component reference to the client component */
RSL_DchanHdlr comp_ref,
/* RSL (dedicated) Channel number we're handling */
uint8_t trx_nr optional,
IpaStreamId stream_id optional,
RslChannelNr chan_nr optional,
/* Random Reference */
OCT1 ra optional,
GsmFrameNumber ra_fn optional
};
private function f_cid_by_comp_ref(RSL_DchanHdlr comp_ref)
runs on RSL_Emulation_CT return integer {
var integer i;
for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
if (ispresent(ConnectionTable[i].comp_ref) and
ConnectionTable[i].comp_ref == comp_ref) {
return i;
}
}
log("No Dchan handler for ", comp_ref);
return -1;
}
private function f_cid_by_chan_nr(uint8_t trx_nr, RslChannelNr chan_nr)
runs on RSL_Emulation_CT return integer {
var integer i;
for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
if (ispresent(ConnectionTable[i].chan_nr) and
ConnectionTable[i].chan_nr == chan_nr and ConnectionTable[i].trx_nr == trx_nr) {
return i;
}
}
log("No Dchan handler for ", trx_nr, chan_nr);
return -1;
}
private function f_cid_by_ra_fn(OCT1 ra, GsmFrameNumber fn)
runs on RSL_Emulation_CT return integer {
var integer i;
for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
if (ispresent(ConnectionTable[i].ra) and
ConnectionTable[i].ra == ra and ConnectionTable[i].ra_fn == fn) {
return i;
}
}
log("No Dchan handler for ", ra, fn);
return -1;
}
/* create an ew client with given RA and FN */
private function f_cid_create(OCT1 ra, GsmFrameNumber fn, RSL_DchanHdlr comp_ref)
runs on RSL_Emulation_CT {
var integer i;
for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
if (not ispresent(ConnectionTable[i].ra) and
not ispresent(ConnectionTable[i].trx_nr)) {
ConnectionTable[i].ra := ra;
ConnectionTable[i].ra_fn := fn;
ConnectionTable[i].comp_ref := comp_ref;
return;
}
}
testcase.stop("No free entry in conn table for ", ra, fn);
}
/* create an ew client with given RA and FN */
private function f_cid_create_cnr(uint8_t trx_nr, RslChannelNr chan_nr, RSL_DchanHdlr comp_ref)
runs on RSL_Emulation_CT {
var integer i;
for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
if (not ispresent(ConnectionTable[i].ra) and
not ispresent(ConnectionTable[i].trx_nr)) {
ConnectionTable[i].stream_id := f_streamId_by_trx(trx_nr);
ConnectionTable[i].trx_nr := trx_nr;
ConnectionTable[i].chan_nr := chan_nr;
ConnectionTable[i].comp_ref := comp_ref;
return;
}
}
testcase.stop("No free entry in conn table for ", trx_nr, chan_nr, comp_ref);
}
/* create an ew client with given RA and FN */
private function f_cid_delete_cnr(IpaStreamId stream_id, RslChannelNr chan_nr, RSL_DchanHdlr comp_ref)
runs on RSL_Emulation_CT return integer {
var integer i;
for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
if (ConnectionTable[i].comp_ref == null) {
continue;
}
if (ConnectionTable[i].stream_id == stream_id and
ConnectionTable[i].chan_nr == chan_nr and
ConnectionTable[i].comp_ref == comp_ref) {
f_cid_clear(i);
}
}
log("Unable to find entry to delete for ", stream_id, chan_nr, comp_ref);
return -1;
}
private function f_cid_clear(integer cid)
runs on RSL_Emulation_CT {
ConnectionTable[cid].ra := omit;
ConnectionTable[cid].ra_fn := omit;
ConnectionTable[cid].trx_nr := omit;
ConnectionTable[cid].stream_id := omit;
ConnectionTable[cid].chan_nr := omit;
ConnectionTable[cid].comp_ref := null;
}
/* last activation for a given channel number */
type record LastActData {
uint8_t trx_nr optional,
RslChannelNr chan_nr optional,
RSL_Message chan_act optional
}
private function f_store_last_act_data(uint8_t trx_nr, RslChannelNr chan_nr, RSL_Message chan_act)
runs on RSL_Emulation_CT {
for (var integer i := 0; i < sizeof(LastActTable); i := i+1) {
if (not ispresent(LastActTable[i].chan_nr) or
(LastActTable[i].chan_nr == chan_nr and LastActTable[i].trx_nr == trx_nr)) {
LastActTable[i].trx_nr := trx_nr;
LastActTable[i].chan_nr := chan_nr;
LastActTable[i].chan_act := chan_act;
return;
}
}
testcase.stop("No space left in LastActTable to store chan_act for ", chan_nr);
}
private function f_lookup_last_act(uint8_t trx_nr, RslChannelNr chan_nr)
runs on RSL_Emulation_CT return RSL_Message {
for (var integer i := 0; i < sizeof(LastActTable); i := i+1) {
if (ispresent(LastActTable[i].chan_nr) and LastActTable[i].chan_nr == chan_nr
and LastActTable[i].trx_nr == trx_nr) {
return LastActTable[i].chan_act;
}
}
testcase.stop("No LastActTable entry found for TRX ", trx_nr, " ", chan_nr);
}
private function f_last_act_table_init() runs on RSL_Emulation_CT {
for (var integer i := 0; i < sizeof(LastActTable); i := i+1) {
LastActTable[i] := { omit, omit, omit };
}
}
type component RSL_Emulation_CT {
/* port facing down towards IPA emulation */
port IPA_RSL_PT IPA_PT;
/* port facing up towards dedicated channel handler */
port RSL_DCHAN_PT CLIENT_PT;
port RSLEM_PROC_PT RSL_PROC;
/* port for Common Channel / TRX Management */
port RSL_CCHAN_PT CCHAN_PT;
/* state of all concurrent connections / dedicated channels */
var ConnectionData ConnectionTable[64];
/* last RSL CHAN ACT for each chan_nr */
var LastActData LastActTable[64];
}
/* template for an ASP_RSL_Unitdata as we receive it from the IPA_Emulateion component */
private template ASP_RSL_Unitdata tr_RSL(template RSL_Message rsl, template IpaStreamId sid := ?) := {
streamId := sid,
rsl := rsl
}
private function f_trx_by_streamId(IpaStreamId id) return integer {
return enum2int(id);
}
private function f_streamId_by_trx(uint8_t trx_nr) return IpaStreamId {
select (trx_nr) {
case (0) { return IPAC_PROTO_RSL_TRX0; }
case (1) { return IPAC_PROTO_RSL_TRX1; }
case (2) { return IPAC_PROTO_RSL_TRX2; }
case (3) { return IPAC_PROTO_RSL_TRX3; }
}
setverdict(fail, "Unknown stream ID ", trx_nr);
mtc.stop;
}
function main(boolean bts_role := true) runs on RSL_Emulation_CT {
var ASP_IPA_Event evt;
var ASP_RSL_Unitdata rx_rsl;
var RSL_Message rx_rsl_msg;
var RSLDC_ChanRqd chan_rqd;
var RSL_DchanHdlr vc_conn;
var RslChannelNr chan_nr;
var uint8_t trx_nr;
var integer cid;
var integer i;
/* special synchronization handling during hand-over */
var boolean dchan_suspended := false;
f_conn_table_init();
f_last_act_table_init();
while (true) {
alt {
[bts_role] IPA_PT.receive(ASP_IPA_Event:{up_down := ASP_IPA_EVENT_UP}) {
}
[not bts_role] IPA_PT.receive(ASP_IPA_Event:{up_down := ASP_IPA_EVENT_UP}) -> value evt {
CCHAN_PT.send(evt);
}
[bts_role] IPA_PT.receive(ASP_IPA_Event:{up_down := ASP_IPA_EVENT_ID_ACK}) {
IPA_PT.send(ts_ASP_RSL_UD(IPAC_PROTO_RSL_TRX0,ts_RSL_PAGING_LOAD_IND(23)));
}
[not bts_role] IPA_PT.receive(ASP_IPA_Event:{up_down := ASP_IPA_EVENT_ID_ACK}) { }
[bts_role] IPA_PT.receive(tr_RSL(tr_RSL_IMM_ASSIGN)) -> value rx_rsl {
var GsmRrMessage rr;
var OCT1 ra;
var GsmFrameNumber fn;
rr := dec_GsmRrMessage(rx_rsl.rsl.ies[1].body.full_imm_ass_info.payload);
if (ischosen(rr.payload.imm_ass)) {
ra := bit2oct(rr.payload.imm_ass.req_ref.ra);
fn := 23; //FIXME(rr.payload.imm_ass);
/* lookup client based on RA+time, deliver to client */
cid := f_cid_by_ra_fn(ra, fn);
if (cid == -1) {
setverdict(fail, "IMM ASS for unknown DChan");
mtc.stop;
}
/* update client with trx_nr */
ConnectionTable[cid].trx_nr := f_trx_by_streamId(rx_rsl.streamId);
ConnectionTable[cid].stream_id := rx_rsl.streamId;
/* update client with chan_nr */
ConnectionTable[cid].chan_nr := rr.payload.imm_ass.chan_desc.chan_nr;
/* TODO: add timer to time-out ConnectionTable entries which
* never get followed-up to */
CLIENT_PT.send(rx_rsl.rsl) to ConnectionTable[cid].comp_ref;
} else if (ischosen(rr.payload.imm_ass_rej)) {
for (i := 0; i < sizeof(rr.payload.imm_ass_rej.payload); i := i + 1) {
ra := bit2oct(rr.payload.imm_ass_rej.payload[i].req_ref.ra);
fn := 23; //FIXME();
/* lookup client based on RA+time, deliver to client */
cid := f_cid_by_ra_fn(ra, fn);
if (cid != -1) {
CLIENT_PT.send(rx_rsl.rsl) to ConnectionTable[cid].comp_ref;
/* delete ClientTable entry, as it failed */
f_cid_clear(cid);
}
}
}
}
[bts_role] IPA_PT.receive(tr_RSL(tr_RSL_PAGING_CMD(?, ?))) -> value rx_rsl {
/* broadcast to all clients? */
for (i := 0; i < sizeof(ConnectionTable); i := i + 1) {
if (ispresent(ConnectionTable[i].comp_ref)) {
CLIENT_PT.send(rx_rsl.rsl) to ConnectionTable[i].comp_ref;
}
}
}
/* Forward common channel management to the special port for it */
[] IPA_PT.receive(tr_RSL(tr_RSL_MsgTypeT(?))) -> value rx_rsl {
CCHAN_PT.send(rx_rsl);
}
/* Forward common channel management to the special port for it */
[] IPA_PT.receive(tr_RSL(tr_RSL_MsgTypeC(?))) -> value rx_rsl {
CCHAN_PT.send(rx_rsl);
}
/* blindly acknowledge all channel activations */
[bts_role] IPA_PT.receive(tr_RSL(tr_RSL_MsgTypeD(RSL_MT_CHAN_ACTIV))) -> value rx_rsl {
chan_nr := rx_rsl.rsl.ies[0].body.chan_nr;
trx_nr := f_trx_by_streamId(rx_rsl.streamId);
f_store_last_act_data(trx_nr, chan_nr, rx_rsl.rsl);
IPA_PT.send(ts_ASP_RSL_UD(rx_rsl.streamId, ts_RSL_CHAN_ACT_ACK(chan_nr, 23)));
}
[not dchan_suspended] IPA_PT.receive(tr_RSL(tr_RSL_MsgTypeDR(?))) -> value rx_rsl {
/* dispatch to channel based on ChanId */
cid := f_cid_by_chan_nr(f_trx_by_streamId(rx_rsl.streamId),
rx_rsl.rsl.ies[0].body.chan_nr);
if (cid != -1) {
CLIENT_PT.send(rx_rsl.rsl) to ConnectionTable[cid].comp_ref;
} else {
setverdict(fail, "RSL for unknown Dchan");
mtc.stop;
}
}
[not dchan_suspended] IPA_PT.receive {
setverdict(fail, "Received unknown primitive from IPA");
mtc.stop;
}
[bts_role] CLIENT_PT.receive(RSLDC_ChanRqd:?) -> value chan_rqd sender vc_conn {
/* Store the knowledge that this sender has requested a certain RQ+time */
f_cid_create(chan_rqd.ra, chan_rqd.fn, vc_conn);
IPA_PT.send(ts_ASP_RSL_UD(IPAC_PROTO_RSL_TRX0,
ts_RSL_CHAN_RQD(chan_rqd.ra, chan_rqd.fn)));
}
[] CLIENT_PT.receive(tr_RSL_MsgType(?)) -> value rx_rsl_msg sender vc_conn {
/* forward to BSC */
cid := f_cid_by_comp_ref(vc_conn);
IPA_PT.send(ts_ASP_RSL_UD(ConnectionTable[cid].stream_id, rx_rsl_msg));
}
[] CCHAN_PT.receive(tr_RSL(?)) -> value rx_rsl {
IPA_PT.send(ts_ASP_RSL_UD(rx_rsl.streamId, rx_rsl.rsl));
}
/* explicit registration, e.g. in (non-immediate) assignment case */
[] RSL_PROC.getcall(RSLEM_register:{?,?,?}) -> param(trx_nr, chan_nr, vc_conn) {
f_cid_create_cnr(trx_nr, chan_nr, vc_conn);
RSL_PROC.reply(RSLEM_register:{trx_nr, chan_nr, vc_conn}) to vc_conn;
}
[] RSL_PROC.getcall(RSLEM_unregister:{?,?,?}) -> param(trx_nr, chan_nr, vc_conn) {
cid := f_cid_by_chan_nr(trx_nr, chan_nr);
f_cid_clear(cid);
RSL_PROC.reply(RSLEM_unregister:{trx_nr, chan_nr, vc_conn}) to vc_conn;
}
[] RSL_PROC.getcall(RSLEM_suspend:{true}) -> sender vc_conn {
log("Suspending DChan");
dchan_suspended := true;
RSL_PROC.reply(RSLEM_suspend:{true}) to vc_conn;
}
[] RSL_PROC.getcall(RSLEM_suspend:{false}) -> sender vc_conn {
log("Resuming DChan");
dchan_suspended := false;
RSL_PROC.reply(RSLEM_suspend:{false}) to vc_conn;
}
[] RSL_PROC.getcall(RSLEM_get_last_act:{?,?,?}) -> param(trx_nr, chan_nr) sender vc_conn {
var RSL_Message last_chan_act := f_lookup_last_act(trx_nr, chan_nr);
RSL_PROC.reply(RSLEM_get_last_act:{trx_nr, chan_nr, last_chan_act}) to vc_conn;
}
}
}
}
private function f_conn_table_init()
runs on RSL_Emulation_CT {
var integer i;
/* Initialize the ConnectionTable */
for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
f_cid_clear(i);
}
}
/* client/conn_hdlr side function to use procedure port to register stream_id/chan_nr */
function f_rslem_register(uint8_t trx_nr, RslChannelNr chan_nr, RSLEM_PROC_PT PT := RSL_PROC)
runs on RSL_DchanHdlr {
PT.call(RSLEM_register:{trx_nr, chan_nr, self}) {
[] PT.getreply(RSLEM_register:{?,?,?}) {};
}
}
/* client/conn_hdlr side function to use procedure port to unregister stream_id/chan_nr */
function f_rslem_unregister(uint8_t trx_nr, RslChannelNr chan_nr, RSLEM_PROC_PT PT := RSL_PROC)
runs on RSL_DchanHdlr {
PT.call(RSLEM_unregister:{trx_nr, chan_nr, self}) {
[] PT.getreply(RSLEM_unregister:{?,?,?}) {};
}
}
/* resume handling of RSL DChan messages from IPA until f_rslem_resume() is called */
function f_rslem_suspend(RSLEM_PROC_PT PT)
runs on RSL_DchanHdlr {
PT.call(RSLEM_suspend:{true}) {
[] PT.getreply(RSLEM_suspend:{true}) {};
}
}
/* resume handling of RSL DChan messages after f_rslem_suspend() is called */
function f_rslem_resume(RSLEM_PROC_PT PT)
runs on RSL_DchanHdlr {
PT.call(RSLEM_suspend:{false}) {
[] PT.getreply(RSLEM_suspend:{false}) {};
}
}
/* obtain the last RSL_CHAN_ACT message for the given chan_nr */
function f_rslem_get_last_act(RSLEM_PROC_PT PT, uint8_t trx_nr, RslChannelNr chan_nr)
runs on RSL_DchanHdlr return RSL_Message {
var RSL_Message chan_act;
PT.call(RSLEM_get_last_act:{trx_nr, chan_nr, -}) {
[] PT.getreply(RSLEM_get_last_act:{trx_nr, chan_nr, ?}) -> param(chan_act) {};
}
return chan_act;
}
}