staging: usbip: userspace: usbip_unbind.c: implement using libsysfs

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

 */

#include <sysfs/libsysfs.h>

#include <errno.h>

#include <stdio.h>

#include <string.h>

#include <getopt.h>

#include <unistd.h>

#include "usbip_common.h"

#include "utils.h"

	printf("usage: %s", usbip_unbind_usage_string);

}

static int use_device_by_other(char *busid)

static int unbind_device(char *busid)

{

	int rc;

	int config;

	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[] = "bConfigurationValue";

	char sysfs_mntpath[SYSFS_PATH_MAX];

	char busid_attr_path[SYSFS_PATH_MAX];

	struct sysfs_attribute *busid_attr;

	char *val = NULL;

	int len;

	/* 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;

	}

	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;

		}

	}

	/* read and write the same config value to kick probing */

	config = read_bConfigurationValue(busid);

	if (config < 0) {

		dbg("read bConfigurationValue of %s, failed", busid);

	if (!verified) {

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

		    USBIP_HOST_DRV_NAME);

		goto err_close_usbip_host_drv;

	}

	/*

	 * 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;

	}

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

		 sysfs_mntpath, SYSFS_BUS_NAME, bus_type, SYSFS_DEVICES_NAME,

		 busid, attr_name);

	/* read a device attribute */

	busid_attr = sysfs_open_attribute(busid_attr_path);

	if (!busid_attr) {

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

		    strerror(errno));

		return -1;

	}

	if (sysfs_read_attribute(busid_attr) < 0) {

		err("problem reading attribute: %s", strerror(errno));

		goto err_out;

	}

	len = busid_attr->len;

	val = malloc(len);

	*val = *busid_attr->value;

	sysfs_close_attribute(busid_attr);

	/* notify driver of unbind */

	rc = modify_match_busid(busid, 0);

	if (rc < 0) {

		dbg("del %s to match_busid, failed", busid);

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

		goto err_out;

	}

	/* write the device attribute */

	busid_attr = sysfs_open_attribute(busid_attr_path);

	if (!busid_attr) {

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

		    strerror(errno));

		return -1;

	}

	rc = write_bConfigurationValue(busid, config);

	rc = sysfs_write_attribute(busid_attr, val, len);

	if (rc < 0) {

		dbg("read bConfigurationValue of %s, failed", busid);

		return -1;

		err("problem writing attribute: %s", strerror(errno));

		goto err_out;

	}

	sysfs_close_attribute(busid_attr);

	info("bind %s to other drivers than usbip, complete!", busid);

	ret = 0;

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

	return 0;

err_out:

	free(val);

err_close_usbip_host_drv:

	sysfs_close_driver(usbip_host_drv);

	return ret;

}

int usbip_unbind(int argc, char *argv[])

		{ "busid", required_argument, NULL, 'b' },

		{ NULL,    0,                 NULL,  0  }

	};

	int opt;

	int ret = -1;

		switch (opt) {

		case 'b':

			ret = use_device_by_other(optarg);

			ret = unbind_device(optarg);

			goto out;

		default:

			goto err_out;