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osmo-ttcn3-hacks
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BTS_Tests: add a hierarchy of L1CTL/LAPDm/DCCH altsteps 

In TTCN-3 it's possible to call one altstep from another.  This
allows us to build complex hierarchies of simple altsteps, where
one is built on top of the others.  I call this altstep-oriented
programming.  This change adds the following hierarchy:

* as_l1ctl_dl_msg() - triggers on receipt of a L1CTL DATA.ind
  matching the given RSL chan_nr/link_id and data templates;

* as_dl_lapdm_dummy() - triggers on receipt of dummy LAPDm
  func=UI frames with empty payload (repeats by default);

* as_dl_dcch_lapdm_ab() - triggers on receipt of a Downlink DCCH
  containing a L2 payload that matches the given LAPDm frame;

* as_dl_dcch_pdu() - triggers on receipt of a LAPDm AB frame
  with a L3 payload matching the given template.

All of these altsteps (except as_dl_lapdm_dummy()) expect an 'out'
parameter, which will hold the matched (and possibly decoded) data.

Example:

  var PDU_ML3_NW_MS pdu;
  alt {
  [] as_dl_lapdm_dummy(); /* Ignore empty LAPDm func=UI frames */
  [] as_dl_dcch_pdu(pdu, tr_CM_SERV_ACC) { setverdict(pass); }
  [] as_dl_dcch_pdu(pdu, tr_CM_SERV_REJ) { setverdict(fail); }
  [] as_dl_dcch_pdu(pdu, ?) { setverdict(inconc, "Unexpected PDU"); }
  }

Change-Id: Ia4d502488cbb6bccc4d2656206ae6649bfa71007
Related: SYS#5838
This commit is contained in:
Vadim Yanitskiy 2022-03-12 13:29:26 +03:00 committed by fixeria
parent 5e05ea1310
commit f8a9df558f
1 changed files with 56 additions and 0 deletions
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56
bts/BTS_Tests.ttcn
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@ -873,6 +873,62 @@ friend template ConnHdlrPars t_Pars(template RslChannelNr chan_nr,
}
}
/* This altstep triggers on receipt of a L1CTL DATA.ind matching the given
* RSL chan_nr/link_id and data templates. Used as a base for other altsteps. */
private altstep as_l1ctl_dl_msg(out L1ctlDlMessage msg,
template (present) octetstring tr_data := ?,
template (present) RslChannelNr chan_nr := ?,
template (present) RslLinkId link_id := ?)
runs on ConnHdlr {
[] L1CTL.receive(tr_L1CTL_DATA_IND(chan_nr, link_id, tr_data)) -> value msg;
}
/* This altstep is built on top of as_l1ctl_dl_msg(), and triggers on receipt
* of dummy LAPDm func=UI frames with empty payload. Repeats by default. */
private altstep as_dl_lapdm_dummy(template (present) RslChannelNr chan_nr := ?,
template (present) RslLinkId link_id := ?,
template (present) LapdmSapi sapi := ?,
boolean do_repeat := true)
runs on ConnHdlr {
template (present) LapdmFrame tr_frame := tr_LAPDm_UI(sapi, true, ''O);
var L1ctlDlMessage dl_msg;
[] as_l1ctl_dl_msg(dl_msg, decmatch tr_frame, chan_nr, link_id) {
if (do_repeat) {
repeat;
}
}
}
/* This altstep triggers on receipt of a Downlink DCCH containing a L2 payload
* that matches the given LAPDm frame. The L2 is treated as LapdmFrameAB. */
private altstep as_dl_dcch_lapdm_ab(out LapdmFrameAB frame,
template (present) LapdmFrameAB tr_frame := ?,
template (present) RslLinkId link_id := ?)
runs on ConnHdlr {
var L1ctlDlMessage dl_msg;
[] as_l1ctl_dl_msg(dl_msg, decmatch tr_frame, g_chan_nr, link_id) {
frame := dec_LapdmFrameAB(dl_msg.payload.data_ind.payload);
}
}
/* This altstep is built on top of as_dl_dcch_lapdm_ab(), and triggers on receipt
* of a LAPDm AB frame with a L3 payload matching the given template. The L3
* payload is treated as PDU_ML3_NW_MS. */
private altstep as_dl_dcch_pdu(out PDU_ML3_NW_MS pdu,
template (present) PDU_ML3_NW_MS tr_pdu := ?,
template (present) GsmSapi sapi := 0)
runs on ConnHdlr {
template (present) LapdmFrame tr_frame := tr_LAPDm_UI(sapi, true, decmatch tr_pdu);
template (present) RslLinkId link_id := tr_RslLinkID_DCCH(sapi);
var LapdmFrameAB lapdm_frame;
[] as_dl_dcch_lapdm_ab(lapdm_frame, tr_frame.ab, link_id) {
pdu := dec_PDU_ML3_NW_MS(lapdm_frame.payload);
}
}
/***********************************************************************
* Channel Activation / Deactivation
***********************************************************************/