[Spice-devel] [spice-gtk] [PATCH] Provide a method to check if a USB device matches a specific class, subclass and protocol

[Fabiano Fidêncio]

As we only can filter USB devices by their Classes and sometimes it is
not enough (eg: I do not want to have Keyboard and Mouse, but want to
have have Joysticks, being all of them part of HID Class), provide to
the applications a way match the device itself with the desired Class,
SubClass and Protocol, so the applications refine the filter provided
by usbredir.
---
This patch was written based on https://bugzilla.gnome.org/show_bug.cgi?id=698430
Any suggestion to have a shorter short-log is welcome :-)
---
 gtk/map-file             |  1 +
 gtk/spice-glib-sym-file  |  1 +
 gtk/usb-device-manager.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++
 gtk/usb-device-manager.h |  1 +
 4 files changed, 99 insertions(+)

diff --git a/gtk/map-file b/gtk/map-file
index 9f8d04e..6bbf407 100644
--- a/gtk/map-file
+++ b/gtk/map-file
@@ -124,6 +124,7 @@ spice_usb_device_manager_get_devices;
 spice_usb_device_manager_get_devices_with_filter;
 spice_usb_device_manager_get_type;
 spice_usb_device_manager_is_device_connected;
+spice_usb_device_matches_interface;
 spice_usb_device_widget_get_type;
 spice_usb_device_widget_new;
 spice_usbredir_channel_get_type;
diff --git a/gtk/spice-glib-sym-file b/gtk/spice-glib-sym-file
index 2189fa5..83f7f18 100644
--- a/gtk/spice-glib-sym-file
+++ b/gtk/spice-glib-sym-file
@@ -101,6 +101,7 @@ spice_usb_device_manager_get_devices
 spice_usb_device_manager_get_devices_with_filter
 spice_usb_device_manager_get_type
 spice_usb_device_manager_is_device_connected
+spice_usb_device_matches_interface
 spice_usbredir_channel_get_type
 spice_util_get_debug
 spice_util_get_version_string
diff --git a/gtk/usb-device-manager.c b/gtk/usb-device-manager.c
index 5013b6c..6749b0d 100644
--- a/gtk/usb-device-manager.c
+++ b/gtk/usb-device-manager.c
@@ -706,6 +706,30 @@ static gboolean spice_usb_device_manager_get_device_descriptor(
     return TRUE;
 }
 
+static gboolean spice_usb_device_manager_get_config_descriptor(
+    libusb_device *libdev,
+    struct libusb_config_descriptor **config)
+{
+    int errcode;
+    const gchar *errstr;
+
+    g_return_val_if_fail(libdev != NULL, FALSE);
+    g_return_val_if_fail(config != NULL, FALSE);
+
+    errcode = libusb_get_active_config_descriptor(libdev, config);
+    if (errcode < 0) {
+        int bus, addr;
+
+        bus = libusb_get_bus_number(libdev);
+        addr = libusb_get_device_address(libdev);
+        errstr = spice_usbutil_libusb_strerror(errcode);
+        g_warning("Cannot get config descriptor for (%p) %d.%d -- %s(%d)",
+                  libdev, bus, addr, errstr, errcode);
+        return FALSE;
+    }
+    return TRUE;
+}
+
 static gboolean spice_usb_device_manager_get_libdev_vid_pid(
     libusb_device *libdev, int *vid, int *pid)
 {
@@ -1726,7 +1750,79 @@ gchar *spice_usb_device_get_description(SpiceUsbDevice *device, const gchar *for
 #endif
 }
 
+static guint8 spice_usb_device_get_interface_class(libusb_device *libdev)
+{
+    struct libusb_config_descriptor *config;
+    guint8 interface_class;
+
+    g_return_val_if_fail(libdev != NULL, 0);
+
+    config = g_malloc(sizeof(*config));
+    spice_usb_device_manager_get_config_descriptor(libdev, &config);
+    interface_class = config->interface->altsetting->bInterfaceClass;
+    libusb_free_config_descriptor(config);
+
+    return interface_class;
+}
+
+static guint8 spice_usb_device_get_interface_subclass(libusb_device *libdev)
+{
+    struct libusb_config_descriptor *config;
+    guint8 interface_subclass;
+
+    g_return_val_if_fail(libdev != NULL, 0);
+
+    config = g_malloc(sizeof(*config));
+    spice_usb_device_manager_get_config_descriptor(libdev, &config);
+    interface_subclass = config->interface->altsetting->bInterfaceSubClass;
+    libusb_free_config_descriptor(config);
+
+    return interface_subclass;
+}
+
+static guint8 spice_usb_device_get_interface_protocol(libusb_device *libdev)
+{
+    struct libusb_config_descriptor *config;
+    guint8 interface_protocol;
+
+    g_return_val_if_fail(libdev != NULL, 0);
+
+    config = g_malloc(sizeof(*config));
+    spice_usb_device_manager_get_config_descriptor(libdev, &config);
+    interface_protocol = config->interface->altsetting->bInterfaceProtocol;
+    libusb_free_config_descriptor(config);
+
+    return interface_protocol;
+}
+
+/**
+ * spice_usb_device_matches_interface:
+ * @device: #SpiceUsbDevice to check if the interface info matches with
+ * @class: the interface class to be checked
+ * @subclass: the interface usbclass to be checked
+ * @protocol; the interface protocol to be checked
+ *
+ * Compares if the device's interface class, subclass and protocol match with
+ * the received interface class, subclass and protocol.
+ *
+ * Returns: TRUE if the device's interface matches with the receveid one.
+ *          FALSE, otherwise.
+ *
+ * Since: 0.27
+ **/
+gboolean spice_usb_device_matches_interface(const SpiceUsbDevice *device, guint8 class, guint8 subclass, guint8 protocol)
+{
+    const SpiceUsbDeviceInfo *info = (const SpiceUsbDeviceInfo *)device;
+
+    g_return_val_if_fail(info != NULL, FALSE);
+
+    if ((spice_usb_device_get_interface_class(info->libdev) == class) &&
+        (spice_usb_device_get_interface_subclass(info->libdev) == subclass) &&
+        (spice_usb_device_get_interface_protocol(info->libdev) == protocol))
+        return TRUE;
 
+    return FALSE;
+}
 
 #ifdef USE_USBREDIR
 /*
diff --git a/gtk/usb-device-manager.h b/gtk/usb-device-manager.h
index a7e3515..9959fe5 100644
--- a/gtk/usb-device-manager.h
+++ b/gtk/usb-device-manager.h
@@ -89,6 +89,7 @@ GType spice_usb_device_get_type(void);
 GType spice_usb_device_manager_get_type(void);
 
 gchar *spice_usb_device_get_description(SpiceUsbDevice *device, const gchar *format);
+gboolean spice_usb_device_matches_interface(const SpiceUsbDevice *device, guint8 class, guint8 subclass, guint8 protocol);
 
 SpiceUsbDeviceManager *spice_usb_device_manager_get(SpiceSession *session,
                                                     GError **err);
-- 
2.1.0