tools/usb/usbip/src/usbip_unbind.c

   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
  32 static 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
  37 void usbip_unbind_usage(void)
  38 {
  39         printf("usage: %s", usbip_unbind_usage_string);
  40 }
  41
  42 static 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
 105 err_close_udev:
 106         udev_device_unref(dev);
 107         udev_unref(udev);
 108
 109         return ret;
 110 }
 111
 112 int 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
 137 err_out:
 138         usbip_unbind_usage();
 139 out:
 140         return ret;
 141 }