Re: [PATCH] usbip: tools: Add usbip host driver availability check

Shuah Khan
2026-03-10T22:28:58Z

On 3/3/26 01:17, Zongmin Zhou wrote:
> From: Zongmin Zhou <zhouzongmin@kylinos.cn>
>
> Currently, usbip_generic_driver_open() doesn't verify that the required
> kernel module (usbip-host or usbip-vudc) is actually loaded.
> The function returns success even when no driver is present,
> leading to usbipd daemon run success without driver loaded.

Doesn't usbip_generic_driver_open() try to refresh exported
device list and fail? It returns error if it can't find fetch
them.

usbipd starts and the when usbip_host is loaded it works correctly.
Doesn't it?

>
> So add a check function to ensure usbip host driver has been loaded.
>
> Signed-off-by: Zongmin Zhou <zhouzongmin@kylinos.cn>
> ---
> tools/usb/usbip/libsrc/usbip_device_driver.c | 2 ++
> tools/usb/usbip/libsrc/usbip_host_common.c | 31 ++++++++++++++++++++
> tools/usb/usbip/libsrc/usbip_host_common.h | 2 ++
> tools/usb/usbip/libsrc/usbip_host_driver.c | 2 ++
> 4 files changed, 37 insertions(+)
>
> diff --git a/tools/usb/usbip/libsrc/usbip_device_driver.c b/tools/usb/usbip/libsrc/usbip_device_driver.c
> index 927a151fa9aa..6da000fab26d 100644
> --- a/tools/usb/usbip/libsrc/usbip_device_driver.c
> +++ b/tools/usb/usbip/libsrc/usbip_device_driver.c
> @@ -147,6 +147,8 @@ static int usbip_device_driver_open(struct usbip_host_driver *hdriver)
> struct usbip_host_driver device_driver = {
> .edev_list = LIST_HEAD_INIT(device_driver.edev_list),
> .udev_subsystem = "udc",
> + .bus_type = "platform",

Why are we adding this here - user-space shouldn't need to
know what kind of driver this is?

> + .drv_name = USBIP_DEVICE_DRV_NAME,

And the name?

> .ops = {
> .open = usbip_device_driver_open,
> .close = usbip_generic_driver_close,
> diff --git a/tools/usb/usbip/libsrc/usbip_host_common.c b/tools/usb/usbip/libsrc/usbip_host_common.c
> index ca78aa368476..900370095b61 100644
> --- a/tools/usb/usbip/libsrc/usbip_host_common.c
> +++ b/tools/usb/usbip/libsrc/usbip_host_common.c
> @@ -164,6 +164,31 @@ static void usbip_exported_device_destroy(struct list_head *devs)
> }
> }
>
> +/* Check if the usbip host driver is available in sysfs */
> +static int check_driver_available(struct usbip_host_driver *hdriver)
> +{
> + char driver_path[SYSFS_PATH_MAX];
> + struct stat st;
> + int ret;
> +
> + if (!hdriver->drv_name || !hdriver->bus_type)
> + return 0;
> +
> + //Check if the usbip-host or usbip-vudc driver directory exists in sysfs.
> + snprintf(driver_path, sizeof(driver_path), "%s/%s/%s/%s/%s",
> + SYSFS_MNT_PATH, SYSFS_BUS_NAME, hdriver->bus_type,
> + SYSFS_DRIVERS_NAME, hdriver->drv_name);
> +
> + ret = stat(driver_path, &st);
> + if (ret == 0 && S_ISDIR(st.st_mode)) {
> + dbg("driver '%s' is available", hdriver->drv_name);
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> +
> int usbip_generic_driver_open(struct usbip_host_driver *hdriver)
> {
> int rc;
> @@ -174,6 +199,12 @@ int usbip_generic_driver_open(struct usbip_host_driver *hdriver)
> return -1;
> }
>
> + //Check if the required driver is actually available.
> + if (!check_driver_available(hdriver)) {
> + err("please load '%s' kernel module", hdriver->drv_name);
> + goto err;
> + }
> +
> rc = refresh_exported_devices(hdriver);
> if (rc < 0)
> goto err;
> diff --git a/tools/usb/usbip/libsrc/usbip_host_common.h b/tools/usb/usbip/libsrc/usbip_host_common.h
> index f46967c0aa18..cf9bd60846cf 100644
> --- a/tools/usb/usbip/libsrc/usbip_host_common.h
> +++ b/tools/usb/usbip/libsrc/usbip_host_common.h
> @@ -40,6 +40,8 @@ struct usbip_host_driver {
> /* list of exported device */
> struct list_head edev_list;
> const char *udev_subsystem;
> + const char *bus_type;
> + const char *drv_name;
> struct usbip_host_driver_ops ops;
> };
>
> diff --git a/tools/usb/usbip/libsrc/usbip_host_driver.c b/tools/usb/usbip/libsrc/usbip_host_driver.c
> index 573e73ec36bd..e8f9d2ee2497 100644
> --- a/tools/usb/usbip/libsrc/usbip_host_driver.c
> +++ b/tools/usb/usbip/libsrc/usbip_host_driver.c
> @@ -41,6 +41,8 @@ static int usbip_host_driver_open(struct usbip_host_driver *hdriver)
> struct usbip_host_driver host_driver = {
> .edev_list = LIST_HEAD_INIT(host_driver.edev_list),
> .udev_subsystem = "usb",
> + .bus_type = "usb",
> + .drv_name = USBIP_HOST_DRV_NAME,

> .ops = {
> .open = usbip_host_driver_open,
> .close = usbip_generic_driver_close,

I need more to justify these changes.

thanks,
-- Shuah