向 ConnMan 注册 RequestInput 函数的正确方法是什么?

What is the right way to register RequestInput function to ConnMan?

我正在实施 C 应用程序,它应该能够使用 ConnMan 通过 GDbus 连接到外部 Wi-Fi 保护接入点。到目前为止,我发现代理必须在“net.connman.Agent”接口上使用 RequestInput 回调进行注册,以便在连接到受保护的访问点期间提供密码。我正在这样注册代理:

GDBusMessage* methodCallMessage = g_dbus_message_new_method_call("net.connman", "/", "net.connman.Manager", "RegisterAgent");

g_dbus_message_set_body(methodCallMessage, g_variant_new ("(o)", "/test/agent"));
g_dbus_connection_send_message(connection, methodCallMessage, G_DBUS_SEND_MESSAGE_FLAGS_NONE, NULL, &error);

我也注册了如下界面:

guint registration_id = g_dbus_connection_register_object (connection,
                                                           "/test/agent",
                                                           introspection_data->interfaces[0],
                                                           &interface_vtable,
                                                           NULL,
                                                           NULL,
                                                           NULL);

其中 introspection_data 是从 XML 代码生成的,如下所示:

static const gchar introspection_xml[] =
"<node>"
"  <interface name='net.connman.Agent'>"
"    <method name='RequestInput'>"
"      <arg type='oa{sv}' name='service' direction='in'/>"
"      <arg type='a{sv}' name='fields' direction='out'/>"
"    </method>"
"  </interface>"
"</node>";
    
introspection_data = g_dbus_node_info_new_for_xml (introspection_xml, NULL);

和interface_vtable定义如下:

static const GDBusInterfaceVTable interface_vtable =
{
  handle_method_call,
  nullptr,
  nullptr
};

static void
handle_method_call (GDBusConnection       *connection,
                    const gchar           *sender,
                    const gchar           *object_path,
                    const gchar           *interface_name,
                    const gchar           *method_name,
                    GVariant              *parameters,
                    GDBusMethodInvocation *invocation,
                    gpointer               user_data)
{
    printf("Method called!\n");
}

目前我没有在我的处理程序方法中处理任何输入,只是想看看它是否被调用。 但是当我在受保护的服务(在“扫描”之后获得)上调用“连接”时,我得到以下输出:

Call D-Bus method with reply: object = /net/connman/service/wifi_f8c091152c85_52696e6a692773206950686f6e65_managed_psk, interface = net.connman.Service, method name = Connect

(process:2929): GLib-CRITICAL **: 12:43:00.606: g_variant_type_checked_: assertion 'g_variant_type_string_is_valid (type_string)' failed

(process:2929): GLib-CRITICAL **: 12:43:00.606: g_variant_type_is_subtype_of: assertion 'g_variant_type_check (supertype)' failed

(process:2929): GLib-CRITICAL **: 12:43:00.606: g_variant_type_dup_string: assertion 'g_variant_type_check (type)' failed
Replied with error = 'GDBus.Error:net.connman.Error.InvalidArguments: Invalid arguments'

据我所知,这可能是 RequestInput 签名的问题,但我只看到 'oa{sv}' 用于输入,'a{sv}' 用于在不同文章/代码示例等中提到的输出

有没有人遇到过这样的错误?

如有任何建议和解决方案,我们将不胜感激。

谢谢。

自己找到了解决方案。看来签名确实是错误的,正确的是:

static const gchar introspection_xml[] =
  "<node>"
  "  <interface name='net.connman.Agent'>"
  "    <method name='RequestInput'>"
  "      <arg name='service' type='o' direction='in'/>"
  "      <arg name='fields' type='a{sv}' direction='in'/>"
  "      <arg name='fields' type='a{sv}' direction='out'/>"
  "    </method>"
  "  </interface>"
  "</node>";