LXR linux/tools/usb/usbip/src/usbip

   1/*
   2 * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
   3 *               2005-2007 Takahiro Hirofuchi
   4 *
   5 * This program is free software: you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License as published by
   7 * the Free Software Foundation, either version 2 of the License, or
   8 * (at your option) any later version.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19#include <libudev.h>
  20
  21#include <errno.h>
  22#include <stdio.h>
  23#include <string.h>
  24
  25#include <getopt.h>
  26
  27#include "usbip_common.h"
  28#include "utils.h"
  29#include "usbip.h"
  30#include "sysfs_utils.h"
  31
  32static const char usbip_unbind_usage_string[] =
  33        "usbip unbind <args>\n"
  34        "    -b, --busid=<busid>    Unbind " USBIP_HOST_DRV_NAME ".ko from "
  35        "device on <busid>\n";
  36
  37void usbip_unbind_usage(void)
  38{
  39        printf("usage: %s", usbip_unbind_usage_string);
  40}
  41
  42static int unbind_device(char *busid)
  43{
  44        char bus_type[] = "usb";
  45        int rc, ret = -1;
  46
  47        char unbind_attr_name[] = "unbind";
  48        char unbind_attr_path[SYSFS_PATH_MAX];
  49        char rebind_attr_name[] = "rebind";
  50        char rebind_attr_path[SYSFS_PATH_MAX];
  51
  52        struct udev *udev;
  53        struct udev_device *dev;
  54        const char *driver;
  55
  56        /* Create libudev context. */
  57        udev = udev_new();
  58
  59        /* Check whether the device with this bus ID exists. */
  60        dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
  61        if (!dev) {
  62                err("device with the specified bus ID does not exist");
  63                goto err_close_udev;
  64        }
  65
  66        /* Check whether the device is using usbip-host driver. */
  67        driver = udev_device_get_driver(dev);
  68        if (!driver || strcmp(driver, "usbip-host")) {
  69                err("device is not bound to usbip-host driver");
  70                goto err_close_udev;
  71        }
  72
  73        /* Unbind device from driver. */
  74        snprintf(unbind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
  75                 SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
  76                 USBIP_HOST_DRV_NAME, unbind_attr_name);
  77
  78        rc = write_sysfs_attribute(unbind_attr_path, busid, strlen(busid));
  79        if (rc < 0) {
  80                err("error unbinding device %s from driver", busid);
  81                goto err_close_udev;
  82        }
  83
  84        /* Notify driver of unbind. */
  85        rc = modify_match_busid(busid, 0);
  86        if (rc < 0) {
  87                err("unable to unbind device on %s", busid);
  88                goto err_close_udev;
  89        }
  90
  91        /* Trigger new probing. */
  92        snprintf(rebind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
  93                        SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
  94                        USBIP_HOST_DRV_NAME, rebind_attr_name);
  95
  96        rc = write_sysfs_attribute(rebind_attr_path, busid, strlen(busid));
  97        if (rc < 0) {
  98                err("error rebinding");
  99                goto err_close_udev;
 100        }
 101
 102        ret = 0;
 103        info("unbind device on busid %s: complete", busid);
 104
 105err_close_udev:
 106        udev_device_unref(dev);
 107        udev_unref(udev);
 108
 109        return ret;
 110}
 111
 112int usbip_unbind(int argc, char *argv[])
 113{
 114        static const struct option opts[] = {
 115                { "busid", required_argument, NULL, 'b' },
 116                { NULL,    0,                 NULL,  0  }
 117        };
 118
 119        int opt;
 120        int ret = -1;
 121
 122        for (;;) {
 123                opt = getopt_long(argc, argv, "b:", opts, NULL);
 124
 125                if (opt == -1)
 126                        break;
 127
 128                switch (opt) {
 129                case 'b':
 130                        ret = unbind_device(optarg);
 131                        goto out;
 132                default:
 133                        goto err_out;
 134                }
 135        }
 136
 137err_out:
 138        usbip_unbind_usage();
 139out:
 140        return ret;
 141}
 142