drivers/staging/usbip/userspace/libsrc/usbip_host_driver.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 <sys/types.h>
  20 #include <sys/stat.h>
  21 #include <fcntl.h>
  22
  23 #include <errno.h>
  24 #include <unistd.h>
  25
  26 #include <libudev.h>
  27
  28 #include "usbip_common.h"
  29 #include "usbip_host_driver.h"
  30 #include "list.h"
  31 #include "sysfs_utils.h"
  32
  33 #undef  PROGNAME
  34 #define PROGNAME "libusbip"
  35
  36 struct usbip_host_driver *host_driver;
  37 struct udev *udev_context;
  38
  39 static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
  40 {
  41         char status_attr_path[SYSFS_PATH_MAX];
  42         int fd;
  43         int length;
  44         char status;
  45         int value = 0;
  46
  47         snprintf(status_attr_path, SYSFS_PATH_MAX, "%s/usbip_status",
  48                  udev->path);
  49
  50         fd = open(status_attr_path, O_RDONLY);
  51         if (fd < 0) {
  52                 err("error opening attribute %s", status_attr_path);
  53                 return -1;
  54         }
  55
  56         length = read(fd, &status, 1);
  57         if (length < 0) {
  58                 err("error reading attribute %s", status_attr_path);
  59                 close(fd);
  60                 return -1;
  61         }
  62
  63         value = atoi(&status);
  64
  65         return value;
  66 }
  67
  68 static
  69 struct usbip_exported_device *usbip_exported_device_new(const char *sdevpath)
  70 {
  71         struct usbip_exported_device *edev = NULL;
  72         struct usbip_exported_device *edev_old;
  73         size_t size;
  74         int i;
  75
  76         edev = calloc(1, sizeof(struct usbip_exported_device));
  77
  78         edev->sudev = udev_device_new_from_syspath(udev_context, sdevpath);
  79         if (!edev->sudev) {
  80                 err("udev_device_new_from_syspath: %s", sdevpath);
  81                 goto err;
  82         }
  83
  84         read_usb_device(edev->sudev, &edev->udev);
  85
  86         edev->status = read_attr_usbip_status(&edev->udev);
  87         if (edev->status < 0)
  88                 goto err;
  89
  90         /* reallocate buffer to include usb interface data */
  91         size = sizeof(struct usbip_exported_device) +
  92                 edev->udev.bNumInterfaces * sizeof(struct usbip_usb_interface);
  93
  94         edev_old = edev;
  95         edev = realloc(edev, size);
  96         if (!edev) {
  97                 edev = edev_old;
  98                 dbg("realloc failed");
  99                 goto err;
 100         }
 101
 102         for (i = 0; i < edev->udev.bNumInterfaces; i++)
 103                 read_usb_interface(&edev->udev, i, &edev->uinf[i]);
 104
 105         return edev;
 106 err:
 107         if (edev->sudev)
 108                 udev_device_unref(edev->sudev);
 109         if (edev)
 110                 free(edev);
 111
 112         return NULL;
 113 }
 114
 115 static int refresh_exported_devices(void)
 116 {
 117         struct usbip_exported_device *edev;
 118         struct udev_enumerate *enumerate;
 119         struct udev_list_entry *devices, *dev_list_entry;
 120         struct udev_device *dev;
 121         const char *path;
 122         const char *driver;
 123
 124         enumerate = udev_enumerate_new(udev_context);
 125         udev_enumerate_add_match_subsystem(enumerate, "usb");
 126         udev_enumerate_scan_devices(enumerate);
 127
 128         devices = udev_enumerate_get_list_entry(enumerate);
 129
 130         udev_list_entry_foreach(dev_list_entry, devices) {
 131                 path = udev_list_entry_get_name(dev_list_entry);
 132                 dev = udev_device_new_from_syspath(udev_context, path);
 133                 if (dev == NULL)
 134                         continue;
 135
 136                 /* Check whether device uses usbip-host driver. */
 137                 driver = udev_device_get_driver(dev);
 138                 if (driver != NULL && !strcmp(driver, USBIP_HOST_DRV_NAME)) {
 139                         edev = usbip_exported_device_new(path);
 140                         if (!edev) {
 141                                 dbg("usbip_exported_device_new failed");
 142                                 continue;
 143                         }
 144
 145                         list_add(&edev->node, &host_driver->edev_list);
 146                         host_driver->ndevs++;
 147                 }
 148         }
 149
 150         return 0;
 151 }
 152
 153 static void usbip_exported_device_destroy(void)
 154 {
 155         struct list_head *i, *tmp;
 156         struct usbip_exported_device *edev;
 157
 158         list_for_each_safe(i, tmp, &host_driver->edev_list) {
 159                 edev = list_entry(i, struct usbip_exported_device, node);
 160                 list_del(i);
 161                 free(edev);
 162         }
 163 }
 164
 165 int usbip_host_driver_open(void)
 166 {
 167         int rc;
 168
 169         udev_context = udev_new();
 170         if (!udev_context) {
 171                 err("udev_new failed");
 172                 return -1;
 173         }
 174
 175         host_driver = calloc(1, sizeof(*host_driver));
 176
 177         host_driver->ndevs = 0;
 178         INIT_LIST_HEAD(&host_driver->edev_list);
 179
 180         rc = refresh_exported_devices();
 181         if (rc < 0)
 182                 goto err_free_host_driver;
 183
 184         return 0;
 185
 186 err_free_host_driver:
 187         free(host_driver);
 188         host_driver = NULL;
 189
 190         udev_unref(udev_context);
 191
 192         return -1;
 193 }
 194
 195 void usbip_host_driver_close(void)
 196 {
 197         if (!host_driver)
 198                 return;
 199
 200         usbip_exported_device_destroy();
 201
 202         free(host_driver);
 203         host_driver = NULL;
 204
 205         udev_unref(udev_context);
 206 }
 207
 208 int usbip_host_refresh_device_list(void)
 209 {
 210         int rc;
 211
 212         usbip_exported_device_destroy();
 213
 214         host_driver->ndevs = 0;
 215         INIT_LIST_HEAD(&host_driver->edev_list);
 216
 217         rc = refresh_exported_devices();
 218         if (rc < 0)
 219                 return -1;
 220
 221         return 0;
 222 }
 223
 224 int usbip_host_export_device(struct usbip_exported_device *edev, int sockfd)
 225 {
 226         char attr_name[] = "usbip_sockfd";
 227         char sockfd_attr_path[SYSFS_PATH_MAX];
 228         char sockfd_buff[30];
 229         int ret;
 230
 231         if (edev->status != SDEV_ST_AVAILABLE) {
 232                 dbg("device not available: %s", edev->udev.busid);
 233                 switch (edev->status) {
 234                 case SDEV_ST_ERROR:
 235                         dbg("status SDEV_ST_ERROR");
 236                         break;
 237                 case SDEV_ST_USED:
 238                         dbg("status SDEV_ST_USED");
 239                         break;
 240                 default:
 241                         dbg("status unknown: 0x%x", edev->status);
 242                 }
 243                 return -1;
 244         }
 245
 246         /* only the first interface is true */
 247         snprintf(sockfd_attr_path, sizeof(sockfd_attr_path), "%s/%s",
 248                  edev->udev.path, attr_name);
 249
 250         snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);
 251
 252         ret = write_sysfs_attribute(sockfd_attr_path, sockfd_buff,
 253                                     strlen(sockfd_buff));
 254         if (ret < 0) {
 255                 err("write_sysfs_attribute failed: sockfd %s to %s",
 256                     sockfd_buff, sockfd_attr_path);
 257                 return ret;
 258         }
 259
 260         info("connect: %s", edev->udev.busid);
 261
 262         return ret;
 263 }
 264
 265 struct usbip_exported_device *usbip_host_get_device(int num)
 266 {
 267         struct list_head *i;
 268         struct usbip_exported_device *edev;
 269         int cnt = 0;
 270
 271         list_for_each(i, &host_driver->edev_list) {
 272                 edev = list_entry(i, struct usbip_exported_device, node);
 273                 if (num == cnt)
 274                         return edev;
 275                 else
 276                         cnt++;
 277         }
 278
 279         return NULL;
 280 }