Re: [PATCH 04/12] staging: usbip: userspace: migrate usbip_list to libudev

[Shuah Khan <shuah.kh@samsung.com>]

On 03/04/2014 12:10 PM, Valentina Manea wrote:
> This patch modifies usbip_list to use libudev.
>
> Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
> ---
>   drivers/staging/usbip/userspace/src/usbip_list.c | 137 +++++++++--------------
>   1 file changed, 51 insertions(+), 86 deletions(-)
>
> diff --git a/drivers/staging/usbip/userspace/src/usbip_list.c b/drivers/staging/usbip/userspace/src/usbip_list.c
> index 8864fa2..2255107 100644
> --- a/drivers/staging/usbip/userspace/src/usbip_list.c
> +++ b/drivers/staging/usbip/userspace/src/usbip_list.c
> @@ -17,7 +17,7 @@
>    */
>
>   #include <sys/types.h>
> -#include <sysfs/libsysfs.h>
> +#include <libudev.h>
>
>   #include <errno.h>
>   #include <stdbool.h>
> @@ -133,8 +133,8 @@ static int list_exported_devices(char *host)
>   	return 0;
>   }
>
> -static void print_device(char *busid, char *vendor, char *product,
> -			 bool parsable)
> +static void print_device(const char *busid, const char *vendor,
> +			 const char *product, bool parsable)
>   {
>   	if (parsable)
>   		printf("busid=%s#usbid=%.4s:%.4s#", busid, vendor, product);
> @@ -148,106 +148,71 @@ static void print_product_name(char *product_name, bool parsable)
>   		printf("   %s\n", product_name);
>   }
>
> -static void print_interface(char *busid, char *driver, bool parsable)
> -{
> -	if (parsable)
> -		printf("%s=%s#", busid, driver);
> -	else
> -		printf("%9s%s -> %s\n", "", busid, driver);
> -}
> -
> -static int is_device(void *x)
> -{
> -	struct sysfs_attribute *devpath;
> -	struct sysfs_device *dev = x;
> -	int ret = 0;
> -
> -	devpath = sysfs_get_device_attr(dev, "devpath");
> -	if (devpath && *devpath->value != '0')
> -		ret = 1;
> -
> -	return ret;
> -}
> -
> -static int devcmp(void *a, void *b)
> -{
> -	return strcmp(a, b);
> -}
> -
>   static int list_devices(bool parsable)
>   {
> -	char bus_type[] = "usb";
> -	char busid[SYSFS_BUS_ID_SIZE];
> +	struct udev *udev;
> +	struct udev_enumerate *enumerate;
> +	struct udev_list_entry *devices, *dev_list_entry;
> +	struct udev_device *dev;
> +	const char *path;
> +	const char *idVendor;
> +	const char *idProduct;
> +	const char *bConfValue;
> +	const char *bNumIntfs;
> +	const char *busid;
>   	char product_name[128];
> -	struct sysfs_bus *ubus;
> -	struct sysfs_device *dev;
> -	struct sysfs_device *intf;
> -	struct sysfs_attribute *idVendor;
> -	struct sysfs_attribute *idProduct;
> -	struct sysfs_attribute *bConfValue;
> -	struct sysfs_attribute *bNumIntfs;
> -	struct dlist *devlist;
> -	int i;
>   	int ret = -1;
>
> -	ubus = sysfs_open_bus(bus_type);
> -	if (!ubus) {
> -		err("could not open %s bus: %s", bus_type, strerror(errno));
> -		return -1;
> -	}
> -
> -	devlist = sysfs_get_bus_devices(ubus);
> -	if (!devlist) {
> -		err("could not get %s bus devices: %s", bus_type,
> -		    strerror(errno));
> -		goto err_out;
> -	}
> -
> -	/* remove interfaces and root hubs from device list */
> -	dlist_filter_sort(devlist, is_device, devcmp);
> -
> -	if (!parsable) {
> -		printf("Local USB devices\n");
> -		printf("=================\n");
> -	}
> -	dlist_for_each_data(devlist, dev, struct sysfs_device) {
> -		idVendor   = sysfs_get_device_attr(dev, "idVendor");
> -		idProduct  = sysfs_get_device_attr(dev, "idProduct");
> -		bConfValue = sysfs_get_device_attr(dev, "bConfigurationValue");
> -		bNumIntfs  = sysfs_get_device_attr(dev, "bNumInterfaces");
> +	/* Create libudev context. */
> +	udev = udev_new();
> +
> +	/* Create libudev device enumeration. */
> +	enumerate = udev_enumerate_new(udev);
> +
> +	/* Take only USB devices that are not hubs and do not have
> +	 * the bInterfaceNumber attribute, i.e. are not interfaces.
> +	 */
> +	udev_enumerate_add_match_subsystem(enumerate, "usb");
> +	udev_enumerate_add_nomatch_sysattr(enumerate, "bDeviceClass", "09");
> +	udev_enumerate_add_nomatch_sysattr(enumerate, "bInterfaceNumber", NULL);
> +	udev_enumerate_scan_devices(enumerate);
> +
> +	devices = udev_enumerate_get_list_entry(enumerate);
> +
> +	/* Show information about each device. */
> +	udev_list_entry_foreach(dev_list_entry, devices) {
> +		path = udev_list_entry_get_name(dev_list_entry);
> +		dev = udev_device_new_from_syspath(udev, path);
> +
> +		/* Get device information. */
> +		idVendor = udev_device_get_sysattr_value(dev, "idVendor");
> +		idProduct = udev_device_get_sysattr_value(dev, "idProduct");
> +		bConfValue = udev_device_get_sysattr_value(dev, "bConfigurationValue");
> +		bNumIntfs = udev_device_get_sysattr_value(dev, "bNumInterfaces");
> +		busid = udev_device_get_sysname(dev);
>   		if (!idVendor || !idProduct || !bConfValue || !bNumIntfs) {
> -			err("problem getting device attributes: %s",
> +			err("Problem getting device attributes: %s",
>   			    strerror(errno));
>   			goto err_out;
>   		}
>
> -		/* get product name */
> +		/* Get product name. */
>   		usbip_names_get_product(product_name, sizeof(product_name),
> -					strtol(idVendor->value, NULL, 16),
> -					strtol(idProduct->value, NULL, 16));
> -		print_device(dev->bus_id, idVendor->value, idProduct->value,
> -			     parsable);
> +					strtol(idVendor, NULL, 16),
> +					strtol(idProduct, NULL, 16));
> +
> +		/* Print information. */
> +		print_device(busid, idVendor, idProduct, parsable);
>   		print_product_name(product_name, parsable);
>
> -		for (i = 0; i < atoi(bNumIntfs->value); i++) {
> -			snprintf(busid, sizeof(busid), "%s:%.1s.%d",
> -				 dev->bus_id, bConfValue->value, i);
> -			intf = sysfs_open_device(bus_type, busid);
> -			if (!intf) {
> -				err("could not open device interface: %s",
> -				    strerror(errno));
> -				goto err_out;
> -			}
> -			print_interface(busid, intf->driver_name, parsable);
> -			sysfs_close_device(intf);
> -		}
>   		printf("\n");
> -	}
>
> -	ret = 0;
Do you need to delete this? Where does ret get set to 0 then?

> +		udev_device_unref(dev);
> +	}
>
>   err_out:
> -	sysfs_close_bus(ubus);
> +	udev_enumerate_unref(enumerate);
> +	udev_unref(udev);
>
>   	return ret;

Is ret = -1 still at this point?

>   }
>

-- Shuah

-- 
Shuah Khan
Senior Linux Kernel Developer - Open Source Group
Samsung Research America(Silicon Valley)
shuah.kh@samsung.com | (970) 672-0658