staging: usbip: userspace: migrate usbip_unbind to libudev

 * along with this program. If not, see <http://www.gnu.org/licenses/>.

 */

#include <sysfs/libsysfs.h>

#include <libudev.h>

#include <errno.h>

#include <stdio.h>

#include "usbip_common.h"

#include "utils.h"

#include "usbip.h"

#include "sysfs_utils.h"

static const char usbip_unbind_usage_string[] =

	"usbip unbind <args>\n"

static int unbind_device(char *busid)

{

	char bus_type[] = "usb";

	struct sysfs_driver *usbip_host_drv;

	struct sysfs_device *dev;

	struct dlist *devlist;

	int verified = 0;

	int rc, ret = -1;

	char attr_name[] = "unbind";

	char sysfs_mntpath[SYSFS_PATH_MAX];

	char unbind_attr_path[SYSFS_PATH_MAX];

	struct sysfs_attribute *unbind_attr;

	/* verify the busid device is using usbip-host */

	usbip_host_drv = sysfs_open_driver(bus_type, USBIP_HOST_DRV_NAME);

	if (!usbip_host_drv) {

		err("could not open %s driver: %s", USBIP_HOST_DRV_NAME,

		    strerror(errno));

		return -1;

	}

	devlist = sysfs_get_driver_devices(usbip_host_drv);

	if (!devlist) {

		err("%s is not in use by any devices", USBIP_HOST_DRV_NAME);

		goto err_close_usbip_host_drv;

	}

	struct udev *udev;

	struct udev_device *dev;

	const char *driver;

	dlist_for_each_data(devlist, dev, struct sysfs_device) {

		if (!strncmp(busid, dev->name, strlen(busid)) &&

		    !strncmp(dev->driver_name, USBIP_HOST_DRV_NAME,

			     strlen(USBIP_HOST_DRV_NAME))) {

			verified = 1;

			break;

		}

	}

	/* Create libudev context. */

	udev = udev_new();

	if (!verified) {

		err("device on busid %s is not using %s", busid,

		    USBIP_HOST_DRV_NAME);

		goto err_close_usbip_host_drv;

	/* Check whether the device with this bus ID exists. */

	dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);

	if (!dev) {

		err("device with the specified bus ID does not exist");

		goto err_close_udev;

	}

	/*

	 * NOTE: A read and write of an attribute value of the device busid

	 * refers to must be done to start probing. That way a rebind of the

	 * default driver for the device occurs.

	 *

	 * This seems very hackish and adds a lot of pointless code. I think it

	 * should be done in the kernel by the driver after del_match_busid is

	 * finished!

	 */

	rc = sysfs_get_mnt_path(sysfs_mntpath, SYSFS_PATH_MAX);

	if (rc < 0) {

		err("sysfs must be mounted: %s", strerror(errno));

		return -1;

	/* Check whether the device is using usbip-host driver. */

	driver = udev_device_get_driver(dev);

	if (!driver || strcmp(driver, "usbip-host")) {

		err("device is not bound to usbip-host driver");

		goto err_close_udev;

	}

	/* Unbind device from driver. */

	snprintf(unbind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",

		 sysfs_mntpath, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,

		 SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,

		 USBIP_HOST_DRV_NAME, attr_name);

	/* read a device attribute */

	unbind_attr = sysfs_open_attribute(unbind_attr_path);

	if (!unbind_attr) {

		err("could not open %s/%s: %s", busid, attr_name,

		    strerror(errno));

		return -1;

	rc = write_sysfs_attribute(unbind_attr_path, busid, strlen(busid));

	if (rc < 0) {

		err("error unbinding device %s from driver", busid);

		goto err_close_udev;

	}

	/* notify driver of unbind */

	/* Notify driver of unbind. */

	rc = modify_match_busid(busid, 0);

	if (rc < 0) {

		err("unable to unbind device on %s", busid);

		goto err_close_udev;

	}

	rc = sysfs_write_attribute(unbind_attr, busid,

				   SYSFS_BUS_ID_SIZE);

		if (rc < 0) {

			dbg("bind driver at %s failed", busid);

		}

	sysfs_close_attribute(unbind_attr);

	ret = 0;

	printf("unbind device on busid %s: complete\n", busid);

	info("unbind device on busid %s: complete", busid);

err_close_usbip_host_drv:

	sysfs_close_driver(usbip_host_drv);

err_close_udev:

	udev_device_unref(dev);

	udev_unref(udev);

	return ret;

}