local-node: periodically send link-measurement requests

Send link-measurement requests to every supporting local-sta in order to
acquire information to assess the link-quality bi-directional.

The link-measurement request is sent each configurable interval. It can
be disabled by configuring the interval to 0.

Signed-off-by: David Bauer <mail@david-bauer.net>

local_node.c

@@ -659,6 +659,33 @@ usteer_local_node_state_next(struct uloop_timeout *timeout)
 	ubus_complete_request_async(ubus_ctx, &ln->req);
 }
 
+static void
+usteer_local_node_request_link_measurement(struct usteer_local_node *ln)
+{
+	unsigned int min_count = DIV_ROUND_UP(config.link_measurement_interval, config.local_sta_update);
+	struct usteer_node *node;
+	struct sta_info *si;
+
+	node = &ln->node;
+
+	if (ln->link_measurement_tries < min_count) {
+		ln->link_measurement_tries++;
+		return;
+	}
+	
+	ln->link_measurement_tries = 0;
+
+	if (!config.link_measurement_interval)
+		return;
+
+	list_for_each_entry(si, &node->sta_info, node_list) {
+		if (si->connected != STA_CONNECTED)
+			continue;
+
+		usteer_ubus_trigger_link_measurement(si);
+	}
+}
+
 static void
 usteer_local_node_update(struct uloop_timeout *timeout)
 {
@@ -680,6 +707,8 @@ usteer_local_node_update(struct uloop_timeout *timeout)
 	uloop_timeout_set(&ln->req_timer, 1);
 	usteer_local_node_kick(ln);
 	usteer_band_steering_perform_steer(ln);
+	usteer_local_node_request_link_measurement(ln);
+
 	uloop_timeout_set(timeout, config.local_sta_update);
 }
 

main.c

@@ -102,6 +102,8 @@ void usteer_init_defaults(void)
 	config.band_steering_interval = 120000;
 	config.band_steering_min_snr = -60;
 
+	config.link_measurement_interval = 30000;
+
 	config.roam_kick_delay = 10000;
 	config.roam_process_timeout = 5 * 1000;
 	config.roam_scan_tries = 3;

node.h

@@ -70,6 +70,8 @@ struct usteer_local_node {
 		bool req_pending;
 		bool status_complete;
 	} netifd;
+
+	unsigned int link_measurement_tries;
 };
 
 struct interface;

openwrt/usteer/files/etc/config/usteer

@@ -125,6 +125,10 @@ config usteer
 	# steered to a higher frequency band
 	#option band_steering_min_snr -60
 
+	# Interval (ms) the device is sent a link-measurement request to help assess
+	# the bi-directional link quality. Setting the interval to 0 disables link-measurements.
+	#option link_measurement_interval 30000
+
 	# Script to run after bringing up a node
 	#option node_up_script ''
 

openwrt/usteer/files/etc/init.d/usteer

@@ -85,7 +85,7 @@ uci_usteer() {
 		roam_kick_delay roam_scan_tries roam_scan_timeout \
 		roam_scan_snr roam_scan_interval \
 		roam_trigger_snr roam_trigger_interval \
-		band_steering_interval band_steering_min_snr \
+		band_steering_interval band_steering_min_snr link_measurement_interval \
 		load_kick_threshold load_kick_delay load_kick_min_clients \
 		load_kick_reason_code
 	do

ubus.c

@@ -183,6 +183,7 @@ struct cfg_item {
 	_cfg(U32, load_kick_reason_code), \
 	_cfg(U32, band_steering_interval), \
 	_cfg(I32, band_steering_min_snr), \
+	_cfg(U32, link_measurement_interval), \
 	_cfg(ARRAY_CB, interfaces), \
 	_cfg(STRING_CB, node_up_script), \
 	_cfg(ARRAY_CB, event_log_types), \
@@ -695,6 +696,20 @@ int usteer_ubus_notify_client_disassoc(struct sta_info *si)
 	return ubus_invoke(ubus_ctx, ln->obj_id, "wnm_disassoc_imminent", b.head, NULL, 0, 100);
 }
 
+int usteer_ubus_trigger_link_measurement(struct sta_info *si)
+{
+	struct usteer_local_node *ln = container_of(si->node, struct usteer_local_node, node);
+
+	if (!usteer_sta_supports_link_measurement(si))
+		return 0;
+
+	blob_buf_init(&b, 0);
+	blobmsg_printf(&b, "addr", MAC_ADDR_FMT, MAC_ADDR_DATA(si->sta->addr));
+	blobmsg_add_u32(&b, "tx-power-used", 5);
+	blobmsg_add_u32(&b, "tx-power-max", 10);
+	return ubus_invoke(ubus_ctx, ln->obj_id, "link_measurement_req", b.head, NULL, 0, 100);
+}
+
 int usteer_ubus_trigger_client_scan(struct sta_info *si)
 {
 	struct usteer_local_node *ln = container_of(si->node, struct usteer_local_node, node);

usteer.h

@@ -191,6 +191,8 @@ struct usteer_config {
 	uint32_t band_steering_interval;
 	int32_t band_steering_min_snr; 
 
+	uint32_t link_measurement_interval;
+
 	uint32_t initial_connect_delay;
 
 	bool load_kick_enabled;
@@ -388,4 +390,6 @@ void usteer_measurement_report_del(struct usteer_measurement_report *mr);
 struct usteer_measurement_report *
 usteer_measurement_report_add(struct sta *sta, struct usteer_node *node, uint8_t rcpi, uint8_t rsni, uint64_t timestamp);
 
+
+int usteer_ubus_trigger_link_measurement(struct sta_info *si);
 #endif