paging: Stop all paging if MSC sends us BSSMAP RESET

When the MSC has lost its state and issues a RESET, we should not only
clear all ongoing radio connections, but we should also stop any paging.
There's no point in paging a subscriber if the MSC doesn't know about
this paging anymore.

Change-Id: If3f53d3bb66ad2dc02db823cb813590c6b59c700
Closes: OS#2736

2 files changed, 26 insertions, 0 deletions

diff --git a/src/libbsc/paging.c b/src/libbsc/paging.c
index f4679de5a..8d54d0a5e 100644
--- a/src/libbsc/paging.c
+++ b/src/libbsc/paging.c
@@ -467,3 +467,26 @@ struct bsc_msc_data *paging_get_msc(struct gsm_bts *bts, struct bsc_subscr *bsub
 
 	return NULL;
 }
+
+/*! Flush all paging requests at a given BTS for a given MSC*/
+void paging_flush_bts(struct gsm_bts *bts, struct bsc_msc_data *msc)
+{
+	struct gsm_paging_request *req, *req2;
+
+	llist_for_each_entry_safe(req, req2, &bts->paging.pending_requests, entry) {
+		if (msc && req->msc != msc)
+			continue;
+		/* now give up the data structure */
+		LOGP(DPAG, LOGL_DEBUG, "Stop paging %s on bts %d (flush).\n", req->bsub->imsi, bts->nr);
+		paging_remove_request(&bts->paging, req);
+	}
+}
+
+/*! Flush all paging requests issued by \a msc on any BTS in \a net */
+void paging_flush_network(struct gsm_network *net, struct bsc_msc_data *msc)
+{
+	struct gsm_bts *bts;
+
+	llist_for_each_entry(bts, &net->bts_list, list)
+		paging_flush_bts(bts, msc);
+}
diff --git a/src/osmo-bsc/osmo_bsc_bssap.c b/src/osmo-bsc/osmo_bsc_bssap.c
index 73776adde..051b74e60 100644
--- a/src/osmo-bsc/osmo_bsc_bssap.c
+++ b/src/osmo-bsc/osmo_bsc_bssap.c
@@ -218,6 +218,9 @@ static int bssmap_handle_reset(struct bsc_msc_data *msc,
 	 * close all active channels on the BTS side as well */
 	osmo_bsc_sigtran_reset(msc);
 
+	/* Drop all ongoing paging requests that this MSC has created on any BTS */
+	paging_flush_network(msc->network, msc);
+
 	/* Inform the MSC that we have received the reset request and
 	 * that we acted accordingly */
 	osmo_bsc_sigtran_tx_reset_ack(msc);