tools/usb/usbip/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 size;
  43         int fd;
  44         int length;
  45         char status;
  46         int value = 0;
  47
  48         size = snprintf(status_attr_path, SYSFS_PATH_MAX, "%s/usbip_status",
  49                         udev->path);
  50         if (size < 0 || (unsigned int)size >= sizeof(status_attr_path)) {
  51                 err("usbip_status path length %i >= %lu or < 0", size,
  52                     (unsigned long)sizeof(status_attr_path));
  53                 return -1;
  54         }
  55
  56         fd = open(status_attr_path, O_RDONLY);
  57         if (fd < 0) {
  58                 err("error opening attribute %s", status_attr_path);
  59                 return -1;
  60         }
  61
  62         length = read(fd, &status, 1);
  63         if (length < 0) {
  64                 err("error reading attribute %s", status_attr_path);
  65                 close(fd);
  66                 return -1;
  67         }
  68
  69         value = atoi(&status);
  70
  71         return value;
  72 }
  73
  74 static
  75 struct usbip_exported_device *usbip_exported_device_new(const char *sdevpath)
  76 {
  77         struct usbip_exported_device *edev = NULL;
  78         struct usbip_exported_device *edev_old;
  79         size_t size;
  80         int i;
  81
  82         edev = calloc(1, sizeof(struct usbip_exported_device));
  83
  84         edev->sudev = udev_device_new_from_syspath(udev_context, sdevpath);
  85         if (!edev->sudev) {
  86                 err("udev_device_new_from_syspath: %s", sdevpath);
  87                 goto err;
  88         }
  89
  90         read_usb_device(edev->sudev, &edev->udev);
  91
  92         edev->status = read_attr_usbip_status(&edev->udev);
  93         if (edev->status < 0)
  94                 goto err;
  95
  96         /* reallocate buffer to include usb interface data */
  97         size = sizeof(struct usbip_exported_device) +
  98                 edev->udev.bNumInterfaces * sizeof(struct usbip_usb_interface);
  99
 100         edev_old = edev;
 101         edev = realloc(edev, size);
 102         if (!edev) {
 103                 edev = edev_old;
 104                 dbg("realloc failed");
 105                 goto err;
 106         }
 107
 108         for (i = 0; i < edev->udev.bNumInterfaces; i++)
 109                 read_usb_interface(&edev->udev, i, &edev->uinf[i]);
 110
 111         return edev;
 112 err:
 113         if (edev->sudev)
 114                 udev_device_unref(edev->sudev);
 115         if (edev)
 116                 free(edev);
 117
 118         return NULL;
 119 }
 120
 121 static int refresh_exported_devices(void)
 122 {
 123         struct usbip_exported_device *edev;
 124         struct udev_enumerate *enumerate;
 125         struct udev_list_entry *devices, *dev_list_entry;
 126         struct udev_device *dev;
 127         const char *path;
 128         const char *driver;
 129
 130         enumerate = udev_enumerate_new(udev_context);
 131         udev_enumerate_add_match_subsystem(enumerate, "usb");
 132         udev_enumerate_scan_devices(enumerate);
 133
 134         devices = udev_enumerate_get_list_entry(enumerate);
 135
 136         udev_list_entry_foreach(dev_list_entry, devices) {
 137                 path = udev_list_entry_get_name(dev_list_entry);
 138                 dev = udev_device_new_from_syspath(udev_context, path);
 139                 if (dev == NULL)
 140                         continue;
 141
 142                 /* Check whether device uses usbip-host driver. */
 143                 driver = udev_device_get_driver(dev);
 144                 if (driver != NULL && !strcmp(driver, USBIP_HOST_DRV_NAME)) {
 145                         edev = usbip_exported_device_new(path);
 146                         if (!edev) {
 147                                 dbg("usbip_exported_device_new failed");
 148                                 continue;
 149                         }
 150
 151                         list_add(&edev->node, &host_driver->edev_list);
 152                         host_driver->ndevs++;
 153                 }
 154         }
 155
 156         return 0;
 157 }
 158
 159 static void usbip_exported_device_destroy(void)
 160 {
 161         struct list_head *i, *tmp;
 162         struct usbip_exported_device *edev;
 163
 164         list_for_each_safe(i, tmp, &host_driver->edev_list) {
 165                 edev = list_entry(i, struct usbip_exported_device, node);
 166                 list_del(i);
 167                 free(edev);
 168         }
 169 }
 170
 171 int usbip_host_driver_open(void)
 172 {
 173         int rc;
 174
 175         udev_context = udev_new();
 176         if (!udev_context) {
 177                 err("udev_new failed");
 178                 return -1;
 179         }
 180
 181         host_driver = calloc(1, sizeof(*host_driver));
 182
 183         host_driver->ndevs = 0;
 184         INIT_LIST_HEAD(&host_driver->edev_list);
 185
 186         rc = refresh_exported_devices();
 187         if (rc < 0)
 188                 goto err_free_host_driver;
 189
 190         return 0;
 191
 192 err_free_host_driver:
 193         free(host_driver);
 194         host_driver = NULL;
 195
 196         udev_unref(udev_context);
 197
 198         return -1;
 199 }
 200
 201 void usbip_host_driver_close(void)
 202 {
 203         if (!host_driver)
 204                 return;
 205
 206         usbip_exported_device_destroy();
 207
 208         free(host_driver);
 209         host_driver = NULL;
 210
 211         udev_unref(udev_context);
 212 }
 213
 214 int usbip_host_refresh_device_list(void)
 215 {
 216         int rc;
 217
 218         usbip_exported_device_destroy();
 219
 220         host_driver->ndevs = 0;
 221         INIT_LIST_HEAD(&host_driver->edev_list);
 222
 223         rc = refresh_exported_devices();
 224         if (rc < 0)
 225                 return -1;
 226
 227         return 0;
 228 }
 229
 230 int usbip_host_export_device(struct usbip_exported_device *edev, int sockfd)
 231 {
 232         char attr_name[] = "usbip_sockfd";
 233         char sockfd_attr_path[SYSFS_PATH_MAX];
 234         int size;
 235         char sockfd_buff[30];
 236         int ret;
 237
 238         if (edev->status != SDEV_ST_AVAILABLE) {
 239                 dbg("device not available: %s", edev->udev.busid);
 240                 switch (edev->status) {
 241                 case SDEV_ST_ERROR:
 242                         dbg("status SDEV_ST_ERROR");
 243                         break;
 244                 case SDEV_ST_USED:
 245                         dbg("status SDEV_ST_USED");
 246                         break;
 247                 default:
 248                         dbg("status unknown: 0x%x", edev->status);
 249                 }
 250                 return -1;
 251         }
 252
 253         /* only the first interface is true */
 254         size = snprintf(sockfd_attr_path, sizeof(sockfd_attr_path), "%s/%s",
 255                         edev->udev.path, attr_name);
 256         if (size < 0 || (unsigned int)size >= sizeof(sockfd_attr_path)) {
 257                 err("exported device path length %i >= %lu or < 0", size,
 258                     (unsigned long)sizeof(sockfd_attr_path));
 259                 return -1;
 260         }
 261
 262         size = snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);
 263         if (size < 0 || (unsigned int)size >= sizeof(sockfd_buff)) {
 264                 err("socket length %i >= %lu or < 0", size,
 265                     (unsigned long)sizeof(sockfd_buff));
 266                 return -1;
 267         }
 268
 269         ret = write_sysfs_attribute(sockfd_attr_path, sockfd_buff,
 270                                     strlen(sockfd_buff));
 271         if (ret < 0) {
 272                 err("write_sysfs_attribute failed: sockfd %s to %s",
 273                     sockfd_buff, sockfd_attr_path);
 274                 return ret;
 275         }
 276
 277         info("connect: %s", edev->udev.busid);
 278
 279         return ret;
 280 }
 281
 282 struct usbip_exported_device *usbip_host_get_device(int num)
 283 {
 284         struct list_head *i;
 285         struct usbip_exported_device *edev;
 286         int cnt = 0;
 287
 288         list_for_each(i, &host_driver->edev_list) {
 289                 edev = list_entry(i, struct usbip_exported_device, node);
 290                 if (num == cnt)
 291                         return edev;
 292                 else
 293                         cnt++;
 294         }
 295
 296         return NULL;
 297 }