neels has uploaded this change for review.
do not BSSMAP Clear on lchan rel when LCS is still ongoing
The proper way to fix this is having a use count on the SCCP conn, one
each for a busy lchan and a busy Location Request. That would require a
bunch more work and testing.
This patch is the least-effort way to avoid the following scenario:
Emergency call is started;
Location Request is started to locate the emergency;
lchan releases early for any reason;
Perfectly fine Location Request gets canceled by Clear Request;
The information was there, but we did not forward the location;
No help at emergency because of my code.
Allow Location Request to complete for these cases:
- rx RLL REL IND (or any other reason for gscon_lchan_releasing())
- rx RSL CONN FAIL
Related: SYS#5912
Related: Idea690a4aa4aecbe4642a16e96d086cc0538564a (osmo-ttcn3-hacks)
Change-Id: Ib44dd05b0adee84234f671313b156ff6625357cc
---
M src/osmo-bsc/bsc_subscr_conn_fsm.c
1 file changed, 6 insertions(+), 3 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/93/28093/1
diff --git a/src/osmo-bsc/bsc_subscr_conn_fsm.c b/src/osmo-bsc/bsc_subscr_conn_fsm.c
index 428d200..54d3975 100644
--- a/src/osmo-bsc/bsc_subscr_conn_fsm.c
+++ b/src/osmo-bsc/bsc_subscr_conn_fsm.c
@@ -878,8 +878,9 @@
lchan_forget_conn(conn->lchan);
conn->lchan = NULL;
}
- /* If the conn has no lchan anymore, it was released by the BTS and needs to Clear towards MSC. */
- if (!conn->lchan) {
+ /* If the conn has no lchan anymore, it was released by the BTS and needs to Clear towards MSC.
+ * However, if a Location Request is still busy, do not send Clear Request. */
+ if (!conn->lchan && !conn->lcs.loc_req) {
switch (conn->fi->state) {
case ST_WAIT_CC:
/* The SCCP connection was not yet confirmed by a CC, the BSSAP is not fully established
@@ -984,7 +985,9 @@
conn->lchan->release.rr_cause =
bsc_gsm48_rr_cause_from_rsl_cause(conn->lchan->release.rsl_error_cause);
}
- gscon_bssmap_clear(conn, GSM0808_CAUSE_RADIO_INTERFACE_FAILURE);
+ /* Request BSSMAP Clear, but do not abort an ongoing Location Request */
+ if (!conn->lcs.loc_req)
+ gscon_bssmap_clear(conn, GSM0808_CAUSE_RADIO_INTERFACE_FAILURE);
break;
case GSCON_EV_MGW_MDCX_RESP_MSC:
LOGPFSML(fi, LOGL_DEBUG, "Rx MDCX of MSC side (LCLS?)\n");
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