From: Manish Mandlik <mmandlik@xxxxxxxxxx>
This patch implements the RSSI Filter logic for background scanning.
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
Reviewed-by: Alain Michaud <alainm@xxxxxxxxxxxx>
Reviewed-by: Miao-chen Chou <mcchou@xxxxxxxxxxxx>
Reviewed-by: Howard Chung <howardchung@xxxxxxxxxx>
---
Changes in v7:
- Add logs to NULL check of objects to reveal potential bugs
- Rename some members of struct adv_monitor_device
Changes in v5:
- Remove the use of unit test in commit message
Changes in v3:
- Fix commit message
doc/advertisement-monitor-api.txt | 5 +
src/adapter.c | 1 +
src/adv_monitor.c | 296 +++++++++++++++++++++++++++++-
src/adv_monitor.h | 4 +
4 files changed, 302 insertions(+), 4 deletions(-)
diff --git a/doc/advertisement-monitor-api.txt b/doc/advertisement-monitor-api.txt
index e09b6fd25..92c8ffc38 100644
--- a/doc/advertisement-monitor-api.txt
+++ b/doc/advertisement-monitor-api.txt
@@ -70,6 +70,11 @@ Properties string Type [read-only]
dBm indicates unset. The valid range of a timer is 1 to
300 seconds while 0 indicates unset.
+ If the peer device advertising interval is greater than the
+ HighRSSIThresholdTimer, the device will never be found. Similarly,
+ if it is greater than LowRSSIThresholdTimer, the device will be
+ considered as lost. Consider configuring these values accordingly.
+
array{(uint8, uint8, array{byte})} Patterns [read-only, optional]
If Type is set to 0x01, this must exist and has at least
diff --git a/src/adapter.c b/src/adapter.c
index c0053000a..6d0114a6b 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -1214,6 +1214,7 @@ void btd_adapter_remove_device(struct btd_adapter *adapter,
adapter->connect_list = g_slist_remove(adapter->connect_list, dev);
adapter->devices = g_slist_remove(adapter->devices, dev);
+ btd_adv_monitor_device_remove(adapter->adv_monitor_manager, dev);
adapter->discovery_found = g_slist_remove(adapter->discovery_found,
dev);
diff --git a/src/adv_monitor.c b/src/adv_monitor.c
index e441a5566..74351d91e 100644
--- a/src/adv_monitor.c
+++ b/src/adv_monitor.c
@@ -26,6 +26,7 @@
#include "adapter.h"
#include "dbus-common.h"
+#include "device.h"
#include "log.h"
#include "src/error.h"
#include "src/shared/ad.h"
@@ -35,6 +36,8 @@
#include "adv_monitor.h"
+static void monitor_device_free(void *data);
+
#define ADV_MONITOR_INTERFACE "org.bluez.AdvertisementMonitor1"
#define ADV_MONITOR_MGR_INTERFACE "org.bluez.AdvertisementMonitorManager1"
@@ -95,15 +98,36 @@ struct adv_monitor {
enum monitor_state state; /* MONITOR_STATE_* */
- int8_t high_rssi; /* high RSSI threshold */
- uint16_t high_rssi_timeout; /* high RSSI threshold timeout */
- int8_t low_rssi; /* low RSSI threshold */
- uint16_t low_rssi_timeout; /* low RSSI threshold timeout */
+ int8_t high_rssi; /* High RSSI threshold */
+ uint16_t high_rssi_timeout; /* High RSSI threshold timeout */
+ int8_t low_rssi; /* Low RSSI threshold */
+ uint16_t low_rssi_timeout; /* Low RSSI threshold timeout */
+ struct queue *devices; /* List of adv_monitor_device objects */
enum monitor_type type; /* MONITOR_TYPE_* */
struct queue *patterns;
};
+/* Some data like last_seen, timer/timeout values need to be maintained
+ * per device. struct adv_monitor_device maintains such data.
+ */
+struct adv_monitor_device {
+ struct adv_monitor *monitor;
+ struct btd_device *device;
+
+ time_t high_rssi_first_seen; /* Start time when RSSI climbs above
+ * the high RSSI threshold
+ */
+ time_t low_rssi_first_seen; /* Start time when RSSI drops below
+ * the low RSSI threshold
+ */
+ time_t last_seen; /* Time when last Adv was received */
+ bool found; /* State of the device - lost/found */
+ guint lost_timer; /* Timer to track if the device goes
+ * offline/out-of-range
+ */
+};
+
struct app_match_data {
const char *owner;
const char *path;
@@ -150,6 +174,9 @@ static void monitor_free(void *data)
g_dbus_proxy_unref(monitor->proxy);
g_free(monitor->path);
+ queue_destroy(monitor->devices, monitor_device_free);
+ monitor->devices = NULL;
+
queue_destroy(monitor->patterns, pattern_free);
free(monitor);
@@ -248,6 +275,7 @@ static struct adv_monitor *monitor_new(struct adv_monitor_app *app,
monitor->high_rssi_timeout = ADV_MONITOR_UNSET_TIMER;
monitor->low_rssi = ADV_MONITOR_UNSET_RSSI;
monitor->low_rssi_timeout = ADV_MONITOR_UNSET_TIMER;
+ monitor->devices = queue_new();
monitor->type = MONITOR_TYPE_NONE;
monitor->patterns = NULL;
@@ -923,3 +951,263 @@ void btd_adv_monitor_manager_destroy(struct btd_adv_monitor_manager *manager)
manager_destroy(manager);
}
+
+/* Matches a device based on btd_device object */
+static bool monitor_device_match(const void *a, const void *b)
+{
+ const struct adv_monitor_device *dev = a;
+ const struct btd_device *device = b;
+
+ if (!dev) {
+ error("Unexpected NULL adv_monitor_device object upon match");
+ return false;
+ }
+
+ if (dev->device != device)
+ return false;
+
+ return true;
+}
+
+/* Frees a monitor device object */
+static void monitor_device_free(void *data)
+{
+ struct adv_monitor_device *dev = data;
+
+ if (!dev) {
+ error("Unexpected NULL adv_monitor_device object upon free");
+ return;
+ }
+
+ if (dev->lost_timer) {
+ g_source_remove(dev->lost_timer);
+ dev->lost_timer = 0;
+ }
+
+ dev->monitor = NULL;
+ dev->device = NULL;
+
+ free(dev);
+}
+
+/* Removes a device from monitor->devices list */
+static void remove_device_from_monitor(void *data, void *user_data)
+{
+ struct adv_monitor *monitor = data;
+ struct btd_device *device = user_data;
+ struct adv_monitor_device *dev = NULL;
+
+ if (!monitor) {
+ error("Unexpected NULL adv_monitor object upon device remove");
+ return;
+ }
+
+ dev = queue_remove_if(monitor->devices, monitor_device_match, device);
+ if (dev) {
+ DBG("Device removed from the Adv Monitor at path %s",
+ monitor->path);
+ monitor_device_free(dev);
+ }
+}
+
+/* Removes a device from every monitor in an app */
+static void remove_device_from_app(void *data, void *user_data)
+{
+ struct adv_monitor_app *app = data;
+ struct btd_device *device = user_data;
+
+ if (!app) {
+ error("Unexpected NULL adv_monitor_app object upon device "
+ "remove");
+ return;
+ }
+
+ queue_foreach(app->monitors, remove_device_from_monitor, device);
+}
+
+/* Removes a device from every monitor in all apps */
+void btd_adv_monitor_device_remove(struct btd_adv_monitor_manager *manager,
+ struct btd_device *device)
+{
+ if (!manager || !device)
+ return;
+
+ queue_foreach(manager->apps, remove_device_from_app, device);
+}
+
+/* Creates a device object to track the per-device information */
+static struct adv_monitor_device *monitor_device_create(
+ struct adv_monitor *monitor,
+ struct btd_device *device)
+{
+ struct adv_monitor_device *dev = NULL;
+
+ dev = new0(struct adv_monitor_device, 1);
+ if (!dev)
+ return NULL;
+
+ dev->monitor = monitor;
+ dev->device = device;
+
+ queue_push_tail(monitor->devices, dev);
+
+ return dev;
+}
+
+/* Includes found/lost device's object path into the dbus message */
+static void report_device_state_setup(DBusMessageIter *iter, void *user_data)
+{
+ const char *path = device_get_path(user_data);
+
+ dbus_message_iter_append_basic(iter, DBUS_TYPE_OBJECT_PATH, &path);
+}
+
+/* Handles a situation where the device goes offline/out-of-range */
+static gboolean handle_device_lost_timeout(gpointer user_data)
+{
+ struct adv_monitor_device *dev = user_data;
+ struct adv_monitor *monitor = dev->monitor;
+ time_t curr_time = time(NULL);
+
+ DBG("Device Lost timeout triggered for device %p "
+ "for the Adv Monitor at path %s", dev->device, monitor->path);
+
+ dev->lost_timer = 0;
+
+ if (dev->found && dev->last_seen) {
+ /* We were tracking for the Low RSSI filter. Check if there is
+ * any Adv received after the timeout function is invoked.
+ * If not, report the Device Lost event.
+ */
+ if (difftime(curr_time, dev->last_seen) >=
+ monitor->low_rssi_timeout) {
+ dev->found = false;
+
+ DBG("Calling DeviceLost() on Adv Monitor of owner %s "
+ "at path %s", monitor->app->owner, monitor->path);
+
+ g_dbus_proxy_method_call(monitor->proxy, "DeviceLost",
+ report_device_state_setup,
+ NULL, dev->device, NULL);
+ }
+ }
+
+ return FALSE;
+}
+
+/* Filters an Adv based on its RSSI value */
+static void adv_monitor_filter_rssi(struct adv_monitor *monitor,
+ struct btd_device *device, int8_t rssi)
+{
+ struct adv_monitor_device *dev = NULL;
+ time_t curr_time = time(NULL);
+ uint16_t adapter_id = monitor->app->manager->adapter_id;
+
+ /* If the RSSI thresholds and timeouts are not specified, report the
+ * DeviceFound() event without tracking for the RSSI as the Adv has
+ * already matched the pattern filter.
+ */
+ if (monitor->high_rssi == ADV_MONITOR_UNSET_RSSI &&
+ monitor->low_rssi == ADV_MONITOR_UNSET_RSSI &&
+ monitor->high_rssi_timeout == ADV_MONITOR_UNSET_TIMER &&
+ monitor->low_rssi_timeout == ADV_MONITOR_UNSET_TIMER) {
+ DBG("Calling DeviceFound() on Adv Monitor of owner %s "
+ "at path %s", monitor->app->owner, monitor->path);
+
+ g_dbus_proxy_method_call(monitor->proxy, "DeviceFound",
+ report_device_state_setup, NULL,
+ device, NULL);
+
+ return;
+ }
+
+ dev = queue_find(monitor->devices, monitor_device_match, device);
+ if (!dev) {
+ dev = monitor_device_create(monitor, device);
+ if (!dev) {
+ btd_error(adapter_id, "Failed to create Adv Monitor "
+ "device object.");
+ return;
+ }
+ }
+
+ if (dev->lost_timer) {
+ g_source_remove(dev->lost_timer);
+ dev->lost_timer = 0;
+ }
+
+ /* Reset the timings of found/lost if a device has been offline for
+ * longer than the high/low timeouts.
+ */
+ if (dev->last_seen) {
+ if (difftime(curr_time, dev->last_seen) >
+ monitor->high_rssi_timeout) {
+ dev->high_rssi_first_seen = 0;
+ }
+
+ if (difftime(curr_time, dev->last_seen) >
+ monitor->low_rssi_timeout) {
+ dev->low_rssi_first_seen = 0;
+ }
+ }
+ dev->last_seen = curr_time;
+
+ /* Check for the found devices (if the device is not already found) */
+ if (!dev->found && rssi > monitor->high_rssi) {
+ if (dev->high_rssi_first_seen) {
+ if (difftime(curr_time, dev->high_rssi_first_seen) >=
+ monitor->high_rssi_timeout) {
+ dev->found = true;
+
+ DBG("Calling DeviceFound() on Adv Monitor "
+ "of owner %s at path %s",
+ monitor->app->owner, monitor->path);
+
+ g_dbus_proxy_method_call(
+ monitor->proxy, "DeviceFound",
+ report_device_state_setup, NULL,
+ dev->device, NULL);
+ }
+ } else {
+ dev->high_rssi_first_seen = curr_time;
+ }
+ } else {
+ dev->high_rssi_first_seen = 0;
+ }
+
+ /* Check for the lost devices (only if the device is already found, as
+ * it doesn't make any sense to report the Device Lost event if the
+ * device is not found yet)
+ */
+ if (dev->found && rssi < monitor->low_rssi) {
+ if (dev->low_rssi_first_seen) {
+ if (difftime(curr_time, dev->low_rssi_first_seen) >=
+ monitor->low_rssi_timeout) {
+ dev->found = false;
+
+ DBG("Calling DeviceLost() on Adv Monitor "
+ "of owner %s at path %s",
+ monitor->app->owner, monitor->path);
+
+ g_dbus_proxy_method_call(
+ monitor->proxy, "DeviceLost",
+ report_device_state_setup, NULL,
+ dev->device, NULL);
+ }
+ } else {
+ dev->low_rssi_first_seen = curr_time;
+ }
+ } else {
+ dev->low_rssi_first_seen = 0;
+ }
+
+ /* Setup a timer to track if the device goes offline/out-of-range, only
+ * if we are tracking for the Low RSSI Threshold. If we are tracking
+ * the High RSSI Threshold, nothing needs to be done.
+ */
+ if (dev->found) {
+ dev->lost_timer =
+ g_timeout_add_seconds(monitor->low_rssi_timeout,
+ handle_device_lost_timeout, dev);
+ }
+}
diff --git a/src/adv_monitor.h b/src/adv_monitor.h
index 5cb372217..13d5d7282 100644
--- a/src/adv_monitor.h
+++ b/src/adv_monitor.h
@@ -12,6 +12,7 @@
#define __ADV_MONITOR_H
struct mgmt;
+struct btd_device;
struct btd_adapter;
struct btd_adv_monitor_manager;
@@ -20,4 +21,7 @@ struct btd_adv_monitor_manager *btd_adv_monitor_manager_create(
struct mgmt *mgmt);
void btd_adv_monitor_manager_destroy(struct btd_adv_monitor_manager *manager);
+void btd_adv_monitor_device_remove(struct btd_adv_monitor_manager *manager,
+ struct btd_device *device);
+
#endif /* __ADV_MONITOR_H */
--
2.26.2
