linux/tools/usb/usbip/libsrc/usbip_host_common.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2015-2016 Samsung Electronics
   4 *               Igor Kotrasinski <i.kotrasinsk@samsung.com>
   5 *               Krzysztof Opasiak <k.opasiak@samsung.com>
   6 *
   7 * Refactored from usbip_host_driver.c, which is:
   8 * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
   9 *               2005-2007 Takahiro Hirofuchi
  10 */
  11
  12#include <sys/types.h>
  13#include <sys/stat.h>
  14#include <fcntl.h>
  15
  16#include <errno.h>
  17#include <unistd.h>
  18
  19#include <libudev.h>
  20
  21#include "usbip_common.h"
  22#include "usbip_host_common.h"
  23#include "list.h"
  24#include "sysfs_utils.h"
  25
  26struct udev *udev_context;
  27
  28static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
  29{
  30        char status_attr_path[SYSFS_PATH_MAX];
  31        int size;
  32        int fd;
  33        int length;
  34        char status[2] = { 0 };
  35        int value = 0;
  36
  37        size = snprintf(status_attr_path, sizeof(status_attr_path),
  38                        "%s/usbip_status", udev->path);
  39        if (size < 0 || (unsigned int)size >= sizeof(status_attr_path)) {
  40                err("usbip_status path length %i >= %lu or < 0", size,
  41                    (long unsigned)sizeof(status_attr_path));
  42                return -1;
  43        }
  44
  45
  46        fd = open(status_attr_path, O_RDONLY);
  47        if (fd < 0) {
  48                err("error opening attribute %s", status_attr_path);
  49                return -1;
  50        }
  51
  52        length = read(fd, status, 1);
  53        if (length < 0) {
  54                err("error reading attribute %s", status_attr_path);
  55                close(fd);
  56                return -1;
  57        }
  58
  59        value = atoi(status);
  60
  61        return value;
  62}
  63
  64static
  65struct usbip_exported_device *usbip_exported_device_new(
  66                struct usbip_host_driver *hdriver, const char *sdevpath)
  67{
  68        struct usbip_exported_device *edev = NULL;
  69        struct usbip_exported_device *edev_old;
  70        size_t size;
  71        int i;
  72
  73        edev = calloc(1, sizeof(struct usbip_exported_device));
  74
  75        edev->sudev =
  76                udev_device_new_from_syspath(udev_context, sdevpath);
  77        if (!edev->sudev) {
  78                err("udev_device_new_from_syspath: %s", sdevpath);
  79                goto err;
  80        }
  81
  82        if (hdriver->ops.read_device(edev->sudev, &edev->udev) < 0)
  83                goto err;
  84
  85        edev->status = read_attr_usbip_status(&edev->udev);
  86        if (edev->status < 0)
  87                goto err;
  88
  89        /* reallocate buffer to include usb interface data */
  90        size = sizeof(struct usbip_exported_device) +
  91                edev->udev.bNumInterfaces * sizeof(struct usbip_usb_interface);
  92
  93        edev_old = edev;
  94        edev = realloc(edev, size);
  95        if (!edev) {
  96                edev = edev_old;
  97                dbg("realloc failed");
  98                goto err;
  99        }
 100
 101        for (i = 0; i < edev->udev.bNumInterfaces; i++) {
 102                /* vudc does not support reading interfaces */
 103                if (!hdriver->ops.read_interface)
 104                        break;
 105                hdriver->ops.read_interface(&edev->udev, i, &edev->uinf[i]);
 106        }
 107
 108        return edev;
 109err:
 110        if (edev->sudev)
 111                udev_device_unref(edev->sudev);
 112        if (edev)
 113                free(edev);
 114
 115        return NULL;
 116}
 117
 118static int refresh_exported_devices(struct usbip_host_driver *hdriver)
 119{
 120        struct usbip_exported_device *edev;
 121        struct udev_enumerate *enumerate;
 122        struct udev_list_entry *devices, *dev_list_entry;
 123        struct udev_device *dev;
 124        const char *path;
 125
 126        enumerate = udev_enumerate_new(udev_context);
 127        udev_enumerate_add_match_subsystem(enumerate, hdriver->udev_subsystem);
 128        udev_enumerate_scan_devices(enumerate);
 129
 130        devices = udev_enumerate_get_list_entry(enumerate);
 131
 132        udev_list_entry_foreach(dev_list_entry, devices) {
 133                path = udev_list_entry_get_name(dev_list_entry);
 134                dev = udev_device_new_from_syspath(udev_context,
 135                                                   path);
 136                if (dev == NULL)
 137                        continue;
 138
 139                /* Check whether device uses usbip driver. */
 140                if (hdriver->ops.is_my_device(dev)) {
 141                        edev = usbip_exported_device_new(hdriver, path);
 142                        if (!edev) {
 143                                dbg("usbip_exported_device_new failed");
 144                                continue;
 145                        }
 146
 147                        list_add(&edev->node, &hdriver->edev_list);
 148                        hdriver->ndevs++;
 149                }
 150        }
 151
 152        return 0;
 153}
 154
 155static void usbip_exported_device_destroy(struct list_head *devs)
 156{
 157        struct list_head *i, *tmp;
 158        struct usbip_exported_device *edev;
 159
 160        list_for_each_safe(i, tmp, devs) {
 161                edev = list_entry(i, struct usbip_exported_device, node);
 162                list_del(i);
 163                free(edev);
 164        }
 165}
 166
 167int usbip_generic_driver_open(struct usbip_host_driver *hdriver)
 168{
 169        int rc;
 170
 171        udev_context = udev_new();
 172        if (!udev_context) {
 173                err("udev_new failed");
 174                return -1;
 175        }
 176
 177        rc = refresh_exported_devices(hdriver);
 178        if (rc < 0)
 179                goto err;
 180        return 0;
 181err:
 182        udev_unref(udev_context);
 183        return -1;
 184}
 185
 186void usbip_generic_driver_close(struct usbip_host_driver *hdriver)
 187{
 188        if (!hdriver)
 189                return;
 190
 191        usbip_exported_device_destroy(&hdriver->edev_list);
 192
 193        udev_unref(udev_context);
 194}
 195
 196int usbip_generic_refresh_device_list(struct usbip_host_driver *hdriver)
 197{
 198        int rc;
 199
 200        usbip_exported_device_destroy(&hdriver->edev_list);
 201
 202        hdriver->ndevs = 0;
 203        INIT_LIST_HEAD(&hdriver->edev_list);
 204
 205        rc = refresh_exported_devices(hdriver);
 206        if (rc < 0)
 207                return -1;
 208
 209        return 0;
 210}
 211
 212int usbip_export_device(struct usbip_exported_device *edev, int sockfd)
 213{
 214        char attr_name[] = "usbip_sockfd";
 215        char sockfd_attr_path[SYSFS_PATH_MAX];
 216        int size;
 217        char sockfd_buff[30];
 218        int ret;
 219
 220        if (edev->status != SDEV_ST_AVAILABLE) {
 221                dbg("device not available: %s", edev->udev.busid);
 222                switch (edev->status) {
 223                case SDEV_ST_ERROR:
 224                        dbg("status SDEV_ST_ERROR");
 225                        ret = ST_DEV_ERR;
 226                        break;
 227                case SDEV_ST_USED:
 228                        dbg("status SDEV_ST_USED");
 229                        ret = ST_DEV_BUSY;
 230                        break;
 231                default:
 232                        dbg("status unknown: 0x%x", edev->status);
 233                        ret = -1;
 234                }
 235                return ret;
 236        }
 237
 238        /* only the first interface is true */
 239        size = snprintf(sockfd_attr_path, sizeof(sockfd_attr_path), "%s/%s",
 240                        edev->udev.path, attr_name);
 241        if (size < 0 || (unsigned int)size >= sizeof(sockfd_attr_path)) {
 242                err("exported device path length %i >= %lu or < 0", size,
 243                    (long unsigned)sizeof(sockfd_attr_path));
 244                return -1;
 245        }
 246
 247        size = snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);
 248        if (size < 0 || (unsigned int)size >= sizeof(sockfd_buff)) {
 249                err("socket length %i >= %lu or < 0", size,
 250                    (long unsigned)sizeof(sockfd_buff));
 251                return -1;
 252        }
 253
 254        ret = write_sysfs_attribute(sockfd_attr_path, sockfd_buff,
 255                                    strlen(sockfd_buff));
 256        if (ret < 0) {
 257                err("write_sysfs_attribute failed: sockfd %s to %s",
 258                    sockfd_buff, sockfd_attr_path);
 259                return ret;
 260        }
 261
 262        info("connect: %s", edev->udev.busid);
 263
 264        return ret;
 265}
 266
 267struct usbip_exported_device *usbip_generic_get_device(
 268                struct usbip_host_driver *hdriver, int num)
 269{
 270        struct list_head *i;
 271        struct usbip_exported_device *edev;
 272        int cnt = 0;
 273
 274        list_for_each(i, &hdriver->edev_list) {
 275                edev = list_entry(i, struct usbip_exported_device, node);
 276                if (num == cnt)
 277                        return edev;
 278                cnt++;
 279        }
 280
 281        return NULL;
 282}
 283