Close LLSK during shutdown procedure

This way we notify the lower layers that state must be reset, eg. when
Iuh conn drops.

Related: OS#6826
Change-Id: I282f3e75d31b3e481136aade34b30074300ab631

include/osmocom/hnodeb/hnb_shutdown_fsm.h

@@ -28,6 +28,7 @@
 
 enum hnb_shutdown_fsm_states {
 	HNB_SHUTDOWN_ST_NONE,
+	HNB_SHUTDOWN_ST_IN_PROGRESS,
 	HNB_SHUTDOWN_ST_EXIT,
 };
 

include/osmocom/hnodeb/llsk.h

@@ -34,6 +34,7 @@ void hnb_llsk_free(struct hnb *hnb);
 int hnb_llsk_start_listen(struct hnb *hnb);
 bool hnb_llsk_connected(const struct hnb *hnb);
 bool hnb_llsk_can_be_configured(struct hnb *hnb);
+void hnb_llsk_close_conn(const struct hnb *hnb);
 
 int ll_addr_type2af(enum u_addr_type t);
 int ll_addr2osa(enum u_addr_type t, const union u_addr *uaddr, uint16_t port, struct osmo_sockaddr *osa);

src/osmo-hnodeb/hnb_shutdown_fsm.c

@@ -43,15 +43,20 @@ static void st_none_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
 }
 
 static void st_none(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	switch (event) {
+	case HNB_SHUTDOWN_EV_START:
+		hnb_shutdown_fsm_state_chg(fi, HNB_SHUTDOWN_ST_IN_PROGRESS);
+		break;
+	}
+}
+
+static void st_in_progress_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
 {
 	struct hnb *hnb = (struct hnb *)fi->priv;
 	struct hnb_ue *ue, *ue_tmp;
 
-	switch (event) {
-	case HNB_SHUTDOWN_EV_START:
-		/* TODO: here we may want to communicate to lower layers over UDsocket that we are shutting down...
-		 * TODO: Also, if Iuh link is still up, maybe send a Hnb deregister req towards HNBGW
-		 */
+	/* TODO: Also, if Iuh link is still up, maybe send a Hnb deregister req towards HNBGW */
 
 	/* Drop active UE contexts, together with their GTP/AUDIO sessions: */
 	llist_for_each_entry_safe(ue, ue_tmp, &hnb->ue_list, list)
@@ -60,9 +65,12 @@ static void st_none(struct osmo_fsm_inst *fi, uint32_t event, void *data)
 	if (osmo_stream_cli_is_connected(hnb->iuh.client))
 		osmo_stream_cli_close(hnb->iuh.client);
 
+	/* Close LLSK to notify lower layers that we are shutting down
+	 * even if we are not exiting the process. */
+	if (hnb_llsk_connected(hnb))
+		hnb_llsk_close_conn(hnb);
+
 	hnb_shutdown_fsm_state_chg(fi, HNB_SHUTDOWN_ST_EXIT);
-		break;
-	}
 }
 
 static void st_exit_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state)
@@ -82,11 +90,17 @@ static struct osmo_fsm_state hnb_shutdown_fsm_states[] = {
 		.in_event_mask =
 			X(HNB_SHUTDOWN_EV_START),
 		.out_state_mask =
-			X(HNB_SHUTDOWN_ST_EXIT),
+			X(HNB_SHUTDOWN_ST_IN_PROGRESS),
 		.name = "NONE",
 		.onenter = st_none_on_enter,
 		.action = st_none,
 	},
+	[HNB_SHUTDOWN_ST_IN_PROGRESS] = {
+		.out_state_mask =
+			X(HNB_SHUTDOWN_ST_EXIT),
+		.name = "IN_PROGRESS",
+		.onenter = st_in_progress_on_enter,
+	},
 	[HNB_SHUTDOWN_ST_EXIT] = {
 		.name = "EXIT",
 		.out_state_mask =

src/osmo-hnodeb/llsk.c

@@ -113,7 +113,12 @@ static int llsk_closed_cb(struct osmo_prim_srv *srv)
 	hnb->llsk.srv = NULL;
 	hnb->llsk.valid_sapi_mask = 0x0;
 	osmo_timer_del(&hnb->llsk.defer_configure_ind_timer);
+
+	/* We actively close the llsk conn during hnb_shutdown, no need to
+	* re-enter shutdown procedure thin that case: */
+	if (!hnb_shutdown_in_progress(hnb))
 		hnb_shutdown(hnb, "LLSK conn dropped", false);
+
 	return 0;
 }
 
@@ -136,6 +141,14 @@ bool hnb_llsk_can_be_configured(struct hnb *hnb)
 	return false;
 }
 
+void hnb_llsk_close_conn(const struct hnb *hnb)
+{
+	if (!hnb_llsk_connected(hnb))
+		return;
+	osmo_prim_srv_close(hnb->llsk.srv);
+	/* pointer NULLed in llsk_closed_cb() */
+}
+
 static void llsk_defer_configure_ind_timer_cb(void *data)
 {
 	struct hnb *hnb = (struct hnb *)data;