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

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
   4 *               2005-2007 Takahiro Hirofuchi
   5 */
   6
   7#include <libudev.h>
   8
   9#include <errno.h>
  10#include <stdio.h>
  11#include <string.h>
  12
  13#include <getopt.h>
  14
  15#include "usbip_common.h"
  16#include "utils.h"
  17#include "usbip.h"
  18#include "sysfs_utils.h"
  19
  20static const char usbip_unbind_usage_string[] =
  21        "usbip unbind <args>\n"
  22        "    -b, --busid=<busid>    Unbind " USBIP_HOST_DRV_NAME ".ko from "
  23        "device on <busid>\n";
  24
  25void usbip_unbind_usage(void)
  26{
  27        printf("usage: %s", usbip_unbind_usage_string);
  28}
  29
  30static int unbind_device(char *busid)
  31{
  32        char bus_type[] = "usb";
  33        int rc, ret = -1;
  34
  35        char unbind_attr_name[] = "unbind";
  36        char unbind_attr_path[SYSFS_PATH_MAX];
  37        char rebind_attr_name[] = "rebind";
  38        char rebind_attr_path[SYSFS_PATH_MAX];
  39
  40        struct udev *udev;
  41        struct udev_device *dev;
  42        const char *driver;
  43
  44        /* Create libudev context. */
  45        udev = udev_new();
  46
  47        /* Check whether the device with this bus ID exists. */
  48        dev = udev_device_new_from_subsystem_sysname(udev, "usb", busid);
  49        if (!dev) {
  50                err("device with the specified bus ID does not exist");
  51                goto err_close_udev;
  52        }
  53
  54        /* Check whether the device is using usbip-host driver. */
  55        driver = udev_device_get_driver(dev);
  56        if (!driver || strcmp(driver, "usbip-host")) {
  57                err("device is not bound to usbip-host driver");
  58                goto err_close_udev;
  59        }
  60
  61        /* Unbind device from driver. */
  62        snprintf(unbind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
  63                 SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
  64                 USBIP_HOST_DRV_NAME, unbind_attr_name);
  65
  66        rc = write_sysfs_attribute(unbind_attr_path, busid, strlen(busid));
  67        if (rc < 0) {
  68                err("error unbinding device %s from driver", busid);
  69                goto err_close_udev;
  70        }
  71
  72        /* Notify driver of unbind. */
  73        rc = modify_match_busid(busid, 0);
  74        if (rc < 0) {
  75                err("unable to unbind device on %s", busid);
  76                goto err_close_udev;
  77        }
  78
  79        /* Trigger new probing. */
  80        snprintf(rebind_attr_path, sizeof(unbind_attr_path), "%s/%s/%s/%s/%s/%s",
  81                        SYSFS_MNT_PATH, SYSFS_BUS_NAME, bus_type, SYSFS_DRIVERS_NAME,
  82                        USBIP_HOST_DRV_NAME, rebind_attr_name);
  83
  84        rc = write_sysfs_attribute(rebind_attr_path, busid, strlen(busid));
  85        if (rc < 0) {
  86                err("error rebinding");
  87                goto err_close_udev;
  88        }
  89
  90        ret = 0;
  91        info("unbind device on busid %s: complete", busid);
  92
  93err_close_udev:
  94        udev_device_unref(dev);
  95        udev_unref(udev);
  96
  97        return ret;
  98}
  99
 100int usbip_unbind(int argc, char *argv[])
 101{
 102        static const struct option opts[] = {
 103                { "busid", required_argument, NULL, 'b' },
 104                { NULL,    0,                 NULL,  0  }
 105        };
 106
 107        int opt;
 108        int ret = -1;
 109
 110        for (;;) {
 111                opt = getopt_long(argc, argv, "b:", opts, NULL);
 112
 113                if (opt == -1)
 114                        break;
 115
 116                switch (opt) {
 117                case 'b':
 118                        ret = unbind_device(optarg);
 119                        goto out;
 120                default:
 121                        goto err_out;
 122                }
 123        }
 124
 125err_out:
 126        usbip_unbind_usage();
 127out:
 128        return ret;
 129}
 130