Bluetooth: Mesh: do not send time status often than 30 seconds

Commit adds restriction for the Time model
to not send Time Status more often than 30 seconds
if this is aresult of state update after Time Set or
Time Status commands.

Signed-off-by: Aleksandr Khromykh <aleksandr.khromykh@nordicsemi.no>

include/bluetooth/mesh/time_srv.h

@@ -86,6 +86,8 @@ struct bt_mesh_time_srv_data {
  struct bt_mesh_time_tai_utc_change tai_utc_change;
  /* The Time Role of the Server instance */
  enum bt_mesh_time_role role;
+ /* The timestamp of the last published Time Status. */
+ int64_t timestamp;
 };
 
 /** Time Server instance.
@@ -103,6 +105,8 @@ struct bt_mesh_time_srv {
  struct bt_mesh_msg_ack_ctx ack_ctx;
  /** Model state structure */
  struct bt_mesh_time_srv_data data;
+ /** Delayable work to randomize status relaying. */
+ struct k_work_delayable status_delay;
 
  /** @brief Update callback.
  *

subsys/bluetooth/mesh/time_srv.c

@@ -10,6 +10,7 @@
 #include "time_util.h"
 
 #define SUBSEC_STEPS 256U
+#define STATUS_INTERVAL_MIN 30000ll
 
 struct bt_mesh_time_srv_settings_data {
  uint8_t role;
@@ -186,6 +187,14 @@ static int send_time_status(struct bt_mesh_model *model,
  return bt_mesh_msg_send(model, ctx, &msg);
 }
 
+static void time_status_send_after_delay(struct k_work *work)
+{
+ struct k_work_delayable *tmp = k_work_delayable_from_work(work);
+ struct bt_mesh_time_srv *srv = CONTAINER_OF(tmp, struct bt_mesh_time_srv, status_delay);
+
+ (void)bt_mesh_time_srv_time_status_send(srv, NULL);
+}
+
 static int handle_time_status(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *ctx,
  struct net_buf_simple *buf)
 {
@@ -217,7 +226,22 @@ static int handle_time_status(struct bt_mesh_model *model, struct bt_mesh_msg_ct
  }
 
  if (srv->data.role == BT_MESH_TIME_RELAY) {
- (void)bt_mesh_time_srv_time_status_send(srv, NULL);
+ /* The time server shouldn't send out statuses more often than every 30 seconds. */
+ if (srv->data.sync.uptime < (srv->data.timestamp + STATUS_INTERVAL_MIN)) {
+ return 0;
+ }
+
+ /* Random delay has been already scheduled. */
+ if (k_work_delayable_is_pending(&srv->status_delay)) {
+ return 0;
+ }
+
+ uint8_t rnd;
+
+ bt_rand(&rnd, sizeof(uint8_t));
+ rnd = 20 + rnd % 30;
+ srv->data.sync.status.uncertainty += rnd;
+ k_work_schedule(&srv->status_delay, K_MSEC(rnd));
  }
 
  return 0;
@@ -243,6 +267,9 @@ static int handle_time_set(struct bt_mesh_model *model, struct bt_mesh_msg_ctx *
  srv->time_update_cb(srv, ctx, BT_MESH_TIME_SRV_SET_UPDATE);
  }
 
+ /* publish state changing */
+ (void)bt_mesh_time_srv_time_status_send(srv, NULL);
+
  send_time_status(model, ctx, srv->data.sync.uptime);
 
  return 0;
@@ -387,18 +414,22 @@ static int bt_mesh_time_srv_init(struct bt_mesh_model *model)
  struct bt_mesh_time_srv *srv = model->user_data;
 
  srv->model = model;
+ srv->data.timestamp = -STATUS_INTERVAL_MIN;
  net_buf_simple_init(srv->pub.msg, 0);
 
+ k_work_init_delayable(&srv->status_delay, time_status_send_after_delay);
+
  return 0;
 }
 
 static void bt_mesh_time_srv_reset(struct bt_mesh_model *model)
 {
  struct bt_mesh_time_srv *srv = model->user_data;
- struct bt_mesh_time_srv_data data = { 0 };
+ struct bt_mesh_time_srv_data data = { .timestamp = -STATUS_INTERVAL_MIN };
 
  srv->data = data;
  net_buf_simple_reset(srv->pub.msg);
+ (void)k_work_cancel_delayable(&srv->status_delay);
 
  if (IS_ENABLED(CONFIG_BT_SETTINGS)) {
  (void)bt_mesh_model_data_store(srv->model, false, NULL, NULL,
@@ -452,18 +483,21 @@ int _bt_mesh_time_srv_update_handler(struct bt_mesh_model *model)
 {
  struct bt_mesh_time_srv *srv = model->user_data;
  struct bt_mesh_time_status status;
+ int64_t uptime;
  int err;
 
  if (srv->data.role != BT_MESH_TIME_AUTHORITY &&
  srv->data.role != BT_MESH_TIME_RELAY) {
  return -EPERM;
  }
 
- err = bt_mesh_time_srv_status(srv, k_uptime_get(), &status);
+ uptime = k_uptime_get();
+ err = bt_mesh_time_srv_status(srv, uptime, &status);
  if (err) {
  return err;
  }
 
+ srv->data.timestamp = uptime;
  /* Account for delay in TX processing: */
  status.uncertainty += CONFIG_BT_MESH_TIME_MESH_HOP_UNCERTAINTY;
 
@@ -476,7 +510,8 @@ int _bt_mesh_time_srv_update_handler(struct bt_mesh_model *model)
 int bt_mesh_time_srv_time_status_send(struct bt_mesh_time_srv *srv,
  struct bt_mesh_msg_ctx *ctx)
 {
- srv->model->pub->ttl = 0;
+ int64_t uptime = k_uptime_get();
+ int err;
 
  /** Mesh Model Specification 5.3.1.2.2:
  * The message (Time Status) may be sent as an unsolicited message at any time
@@ -486,7 +521,14 @@ int bt_mesh_time_srv_time_status_send(struct bt_mesh_time_srv *srv,
  return -EOPNOTSUPP;
  }
 
- return send_time_status(srv->model, ctx, k_uptime_get());
+ srv->model->pub->ttl = 0;
+
+ err = send_time_status(srv->model, ctx, uptime);
+ if (!err) {
+ srv->data.timestamp = uptime;
+ }
+
+ return err;
 }
 
 int bt_mesh_time_srv_status(struct bt_mesh_time_srv *srv, uint64_t uptime,