bluez：使用DBUS获取适配器Adapter(controller)属性

原创

NoName51C_T_O 2022-01-05 11:23:57 博主文章分类：BLUEZ蓝牙 ©著作权

文章标签 bluez bluetooth 蓝牙 linux bluez desktop 文章分类 后端开发

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使用“GetManagedObject”和org.freedesktop.DBus.Properties interface中的“Getall”方法检查适配器的属性。

代码：

/*
 * bluez_adapter_get_properties.c - Print all the properties of the controller
 *  - The example uses GDBUS to get the list of bluetooth controllers using DBUS
 *    interfaces provided by bluez
 *  - If any controller is found, it prints all the properites of the controller
 *  - GetAll method is explicitly used for Getting properties of the controller
 * gcc `pkg-config --cflags glib-2.0 gio-2.0` -Wall -Wextra -o ./bin/bluez_adapter_get_properties ./bluez_adapter_get_properties.c `pkg-config --libs glib-2.0 gio-2.0`
 */

#include <glib.h>
#include <gio/gio.h>

GDBusConnection *con;
static void bluez_property_value(const gchar *key, GVariant *value)
{
  const gchar *type = g_variant_get_type_string(value);

  g_print("\t%s : ", key);
  switch(*type) {
    case 's':
      g_print("%s\n", g_variant_get_string(value, NULL));
      break;
    case 'b':
      g_print("%d\n", g_variant_get_boolean(value));
      break;
    case 'u':
      g_print("%d\n", g_variant_get_uint32(value));
      break;
    case 'a':
      g_print("\n");
      const gchar *uuid;
      GVariantIter i;
      g_variant_iter_init(&i, value);
      while(g_variant_iter_next(&i, "s", &uuid))
        g_print("\t\t%s\n", uuid);
      break;
    default:
      g_print("Other\n");
      break;
  }
}

static void bluez_adapter_getall_property(GDBusConnection *con,
        GAsyncResult *res,
        gpointer data)
{
  GVariant *result = NULL;
  GMainLoop *loop = NULL;

  loop = (GMainLoop *)data;

  result = g_dbus_connection_call_finish(con, res, NULL);
  if(result == NULL)
    g_print("Unable to get result for GetManagedObjects\n");

  if(result) {
    g_print("\n\nUsing \"GetAll\":\n");
    result = g_variant_get_child_value(result, 0);
    const gchar *property_name;
    GVariantIter i;
    GVariant *prop_val;
    g_variant_iter_init(&i, result);
    while(g_variant_iter_next(&i, "{&sv}", &property_name, &prop_val))
      bluez_property_value(property_name, prop_val);
    g_variant_unref(prop_val);
  }

  g_main_loop_quit(loop);
}

static void bluez_list_controllers(GDBusConnection *con,
        GAsyncResult *res,
        gpointer data)
{
  (void)data;
  GVariant *result = NULL;
  GVariantIter i;
  const gchar *object_path;
  GVariant *ifaces_and_properties;

  result = g_dbus_connection_call_finish(con, res, NULL);
  if(result == NULL)
    g_print("Unable to get result for GetManagedObjects\n");

  /* Parse the result */
  if(result) {
    result = g_variant_get_child_value(result, 0);
    g_variant_iter_init(&i, result);
    while(g_variant_iter_next(&i, "{&o@a{sa{sv}}}", &object_path, &ifaces_and_properties)) {
      const gchar *interface_name;
      GVariant *properties;
      GVariantIter ii;
      g_variant_iter_init(&ii, ifaces_and_properties);
      while(g_variant_iter_next(&ii, "{&s@a{sv}}", &interface_name, &properties)) {
        if(g_strstr_len(g_ascii_strdown(interface_name, -1), -1, "adapter")) {
          g_print("[ %s ]\n", object_path);
          const gchar *property_name;
          GVariantIter iii;
          GVariant *prop_val;
          g_variant_iter_init(&iii, properties);
          while(g_variant_iter_next(&iii, "{&sv}", &property_name, &prop_val))
            bluez_property_value(property_name, prop_val);
          g_variant_unref(prop_val);
        }
        g_variant_unref(properties);
      }
      g_variant_unref(ifaces_and_properties);
    }
    g_variant_unref(result);
  }
}

int main(void)
{
  GMainLoop *loop;

  con = g_bus_get_sync(G_BUS_TYPE_SYSTEM, NULL, NULL);
  if(con == NULL) {
    g_print("Not able to get connection to system bus\n");
    return 1;
  }

  loop = g_main_loop_new(NULL, FALSE);
  g_dbus_connection_call(con,
        "org.bluez",
        "/",
        "org.freedesktop.DBus.ObjectManager",
        "GetManagedObjects",
        NULL,
        G_VARIANT_TYPE("(a{oa{sa{sv}}})"),
        G_DBUS_CALL_FLAGS_NONE,
        -1,
        NULL,
        (GAsyncReadyCallback)bluez_list_controllers,
        NULL);

  g_dbus_connection_call(con,
        "org.bluez",
        "/org/bluez/hci0",
        "org.freedesktop.DBus.Properties",
        "GetAll",
        g_variant_new("(s)", "org.bluez.Adapter1"),
        G_VARIANT_TYPE("(a{sv})"),
        G_DBUS_CALL_FLAGS_NONE,
        -1,
        NULL,
        (GAsyncReadyCallback)bluez_adapter_getall_property,
        loop);
  g_main_loop_run(loop);
  g_object_unref(con);
  return 0;
}