Change in osmo-bts[master]: rsl: NACK Chan Activation for lchans on disabled TS

[pespin]

pespin has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bts/+/25702 )


Change subject: rsl: NACK Chan Activation for lchans on disabled TS
......................................................................

rsl: NACK Chan Activation for lchans on disabled TS

A broken BSC could send a Chan Activation on a TS which has not yet been
enabled (or even configured). This is the case with our TTCN3 tests,
where OML side is currently handled in parallel by an osmo-bts while
TTCN3 takes care of the RSL side. This can actually be seen as a
malfunctioning BSC, but it was spotted that given this sequence os
events osmo-bts can crash (see ticket below).

Hence, let's NACK any attempt from a BSC to activate an lchan on a
disabled TS.

Related: OS#5249
Change-Id: I9c3b68487c12efc412a057728a561e061560c544
---
M src/common/rsl.c
1 file changed, 6 insertions(+), 0 deletions(-)



  git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/02/25702/1

diff --git a/src/common/rsl.c b/src/common/rsl.c
index 507a7cf..2db06d7 100644
--- a/src/common/rsl.c
+++ b/src/common/rsl.c
@@ -1633,6 +1633,12 @@
 		return rsl_tx_chan_act_nack(lchan, RSL_ERR_EQUIPMENT_FAIL);
 	}
 
+	if (ts->mo.nm_state.operational != NM_OPSTATE_ENABLED ||
+	    ts->mo.nm_state.availability != NM_AVSTATE_OK) {
+		DEBUGP(DRSL, "%s rx chan activ is not state oper=ENABLED avail=OK, nack!\n", gsm_ts_and_pchan_name(ts));
+		return rsl_tx_chan_act_nack(lchan, RSL_ERR_RR_UNAVAIL);
+	}
+
 	if (ts->pchan == GSM_PCHAN_OSMO_DYN) {
 		ts->dyn.pchan_want = dyn_pchan_from_chan_nr(dch->chan_nr);
 		DEBUGP(DRSL, "%s rx chan activ\n", gsm_ts_and_pchan_name(ts));

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Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Change-Id: I9c3b68487c12efc412a057728a561e061560c544
Gerrit-Change-Number: 25702
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pespin at sysmocom.de>
Gerrit-MessageType: newchange
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