gattlib/dbus/gattlib_notification.c

265 lines
8.7 KiB
C

/*
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2016-2024, Olivier Martin <olivier@labapart.org>
*/
#include <glib.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include "gattlib_internal.h"
struct gattlib_notification_handle {
OrgBluezGattCharacteristic1 *gatt;
gulong signal_id;
uuid_t uuid;
};
#if BLUEZ_VERSION > BLUEZ_VERSIONS(5, 40)
gboolean on_handle_battery_level_property_change(
OrgBluezBattery1 *object,
GVariant *arg_changed_properties,
const gchar *const *arg_invalidated_properties,
gpointer user_data)
{
static guint8 percentage;
gattlib_connection_t* connection = user_data;
GATTLIB_LOG(GATTLIB_DEBUG, "DBUS: on_handle_battery_level_property_change: changed_properties:%s invalidated_properties:%s",
g_variant_print(arg_changed_properties, TRUE),
arg_invalidated_properties);
if (gattlib_has_valid_handler(&connection->notification)) {
// Retrieve 'Value' from 'arg_changed_properties'
if (g_variant_n_children (arg_changed_properties) > 0) {
GVariantIter *iter;
const gchar *key;
GVariant *value;
g_variant_get (arg_changed_properties, "a{sv}", &iter);
while (g_variant_iter_loop (iter, "{&sv}", &key, &value)) {
if (strcmp(key, "Percentage") == 0) {
//TODO: by declaring 'percentage' as a 'static' would mean we could have issue in case of multiple
// GATT connection notifiying to Battery level
percentage = g_variant_get_byte(value);
gattlib_on_gatt_notification(connection,
&m_battery_level_uuid,
(const uint8_t*)&percentage, sizeof(percentage));
break;
}
}
g_variant_iter_free(iter);
}
}
return TRUE;
}
#endif
static gboolean on_handle_characteristic_property_change(
OrgBluezGattCharacteristic1 *object,
GVariant *arg_changed_properties,
const gchar *const *arg_invalidated_properties,
gpointer user_data)
{
gattlib_connection_t* connection = user_data;
if (gattlib_has_valid_handler(&connection->notification)) {
GVariantDict dict;
g_variant_dict_init(&dict, arg_changed_properties);
// Retrieve 'Value' from 'arg_changed_properties'
GVariant* value = g_variant_dict_lookup_value(&dict, "Value", NULL);
if (value != NULL) {
uuid_t uuid;
size_t data_length;
const uint8_t* data = g_variant_get_fixed_array(value, &data_length, sizeof(guchar));
// Dump the content of the notification
//GATTLIB_LOG(GATTLIB_DEBUG, "on_handle_characteristic_property_change: %s: %s", key, g_variant_print(value, TRUE));
GATTLIB_LOG(GATTLIB_DEBUG, "on_handle_characteristic_property_change: Value: Received %d bytes", data_length);
gattlib_string_to_uuid(
org_bluez_gatt_characteristic1_get_uuid(object),
MAX_LEN_UUID_STR + 1,
&uuid);
gattlib_on_gatt_notification(connection, &uuid, data, data_length);
// As per https://developer.gnome.org/glib/stable/glib-GVariant.html#g-variant-iter-loop, clean up `key` and `value`.
g_variant_unref(value);
}
g_variant_dict_end(&dict);
} else {
GATTLIB_LOG(GATTLIB_DEBUG, "on_handle_characteristic_property_change: not a notification handler");
}
return TRUE;
}
static gboolean on_handle_characteristic_indication(
OrgBluezGattCharacteristic1 *object,
GVariant *arg_changed_properties,
const gchar *const *arg_invalidated_properties,
gpointer user_data)
{
gattlib_connection_t* connection = user_data;
if (gattlib_has_valid_handler(&connection->indication)) {
// Retrieve 'Value' from 'arg_changed_properties'
if (g_variant_n_children (arg_changed_properties) > 0) {
GVariantIter *iter;
const gchar *key;
GVariant *value;
g_variant_get (arg_changed_properties, "a{sv}", &iter);
while (g_variant_iter_loop (iter, "{&sv}", &key, &value)) {
GATTLIB_LOG(GATTLIB_DEBUG, "on_handle_characteristic_indication: %s:%s",
key, g_variant_print(value, TRUE));
if (strcmp(key, "Value") == 0) {
uuid_t uuid;
size_t data_length;
const uint8_t* data = g_variant_get_fixed_array(value, &data_length, sizeof(guchar));
gattlib_string_to_uuid(
org_bluez_gatt_characteristic1_get_uuid(object),
MAX_LEN_UUID_STR + 1,
&uuid);
gattlib_on_gatt_notification(connection, &uuid, data, data_length);
break;
}
}
g_variant_iter_free(iter);
}
} else {
GATTLIB_LOG(GATTLIB_DEBUG, "on_handle_characteristic_indication: Not a valid indication handler");
}
return TRUE;
}
static int connect_signal_to_characteristic_uuid(gattlib_connection_t* connection, const uuid_t* uuid, void *callback) {
int ret;
assert(callback != NULL);
struct dbus_characteristic dbus_characteristic = get_characteristic_from_uuid(connection, uuid);
if (dbus_characteristic.type == TYPE_NONE) {
char uuid_str[MAX_LEN_UUID_STR + 1];
gattlib_uuid_to_string(uuid, uuid_str, sizeof(uuid_str));
GATTLIB_LOG(GATTLIB_ERROR, "GATT characteristic '%s' not found", uuid_str);
return GATTLIB_NOT_FOUND;
}
#if BLUEZ_VERSION > BLUEZ_VERSIONS(5, 40)
else if (dbus_characteristic.type == TYPE_BATTERY_LEVEL) {
// Register a handle for notification
g_signal_connect(dbus_characteristic.battery,
"g-properties-changed",
G_CALLBACK (on_handle_battery_level_property_change),
connection);
return GATTLIB_SUCCESS;
} else {
assert(dbus_characteristic.type == TYPE_GATT);
}
#endif
// Register a handle for notification
gulong signal_id = g_signal_connect(dbus_characteristic.gatt,
"g-properties-changed",
G_CALLBACK(callback),
connection);
if (signal_id == 0) {
GATTLIB_LOG(GATTLIB_ERROR, "Failed to connect signal to DBus GATT notification");
return GATTLIB_ERROR_DBUS;
}
// Add signal to the list
struct gattlib_notification_handle *notification_handle = calloc(sizeof(struct gattlib_notification_handle), 1);
if (notification_handle == NULL) {
return GATTLIB_OUT_OF_MEMORY;
}
notification_handle->gatt = dbus_characteristic.gatt;
notification_handle->signal_id = signal_id;
memcpy(&notification_handle->uuid, uuid, sizeof(*uuid));
connection->backend.notified_characteristics = g_list_append(connection->backend.notified_characteristics, notification_handle);
GError *error = NULL;
org_bluez_gatt_characteristic1_call_start_notify_sync(dbus_characteristic.gatt, NULL, &error);
if (error) {
ret = GATTLIB_ERROR_DBUS_WITH_ERROR(error);
GATTLIB_LOG(GATTLIB_ERROR, "Failed to start DBus GATT notification: %s", error->message);
g_error_free(error);
return ret;
} else {
return GATTLIB_SUCCESS;
}
}
static int disconnect_signal_to_characteristic_uuid(gattlib_connection_t* connection, const uuid_t* uuid, void *callback) {
struct gattlib_notification_handle *notification_handle = NULL;
// Find notification handle
for (GList *l = connection->backend.notified_characteristics; l != NULL; l = l->next) {
struct gattlib_notification_handle *notification_handle_ptr = l->data;
if (gattlib_uuid_cmp(&notification_handle_ptr->uuid, uuid) == GATTLIB_SUCCESS) {
notification_handle = notification_handle_ptr;
connection->backend.notified_characteristics = g_list_delete_link(connection->backend.notified_characteristics, l);
break;
}
}
if (notification_handle == NULL) {
return GATTLIB_NOT_FOUND;
}
g_signal_handler_disconnect(notification_handle->gatt, notification_handle->signal_id);
GError *error = NULL;
org_bluez_gatt_characteristic1_call_stop_notify_sync(
notification_handle->gatt, NULL, &error);
free(notification_handle);
if (error) {
GATTLIB_LOG(GATTLIB_ERROR, "Failed to stop DBus GATT notification: %s", error->message);
g_error_free(error);
return GATTLIB_NOT_FOUND;
} else {
return GATTLIB_SUCCESS;
}
}
int gattlib_notification_start(gattlib_connection_t* connection, const uuid_t* uuid) {
return connect_signal_to_characteristic_uuid(connection, uuid, on_handle_characteristic_property_change);
}
int gattlib_notification_stop(gattlib_connection_t* connection, const uuid_t* uuid) {
return disconnect_signal_to_characteristic_uuid(connection, uuid, on_handle_characteristic_property_change);
}
int gattlib_indication_start(gattlib_connection_t* connection, const uuid_t* uuid) {
return connect_signal_to_characteristic_uuid(connection, uuid, on_handle_characteristic_indication);
}
int gattlib_indication_stop(gattlib_connection_t* connection, const uuid_t* uuid) {
return disconnect_signal_to_characteristic_uuid(connection, uuid, on_handle_characteristic_indication);
}
static void end_notification(void *notified_characteristic) {
struct gattlib_notification_handle *notification_handle = notified_characteristic;
g_signal_handler_disconnect(notification_handle->gatt, notification_handle->signal_id);
free(notification_handle);
}
void disconnect_all_notifications(struct _gattlib_connection_backend* backend) {
g_list_free_full(g_steal_pointer(&backend->notified_characteristics), end_notification);
}