root/tools/usb/usbip/src/usbip_unbind.c

DEFINITIONS

1. usbip_unbind_usage
2. unbind_device
3. usbip_unbind

   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 
  20 static 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 
  25 void usbip_unbind_usage(void)
  26 {
  27         printf("usage: %s", usbip_unbind_usage_string);
  28 }
  29 
  30 static 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 
  93 err_close_udev:
  94         udev_device_unref(dev);
  95         udev_unref(udev);
  96 
  97         return ret;
  98 }
  99 
 100 int 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 
 125 err_out:
 126         usbip_unbind_usage();
 127 out:
 128         return ret;
 129 }