libusb/os/netbsd_usb.c

   1 /*
   2  * Copyright © 2011 Martin Pieuchot <mpi@openbsd.org>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #include <config.h>
  20
  21 #include <sys/time.h>
  22 #include <sys/types.h>
  23
  24 #include <errno.h>
  25 #include <fcntl.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30
  31 #include <dev/usb/usb.h>
  32
  33 #include "libusbi.h"
  34
  35 struct device_priv {
  36         char devnode[16];
  37         int fd;
  38
  39         unsigned char *cdesc;                   /* active config descriptor */
  40         usb_device_descriptor_t ddesc;          /* usb device descriptor */
  41 };
  42
  43 struct handle_priv {
  44         int endpoints[USB_MAX_ENDPOINTS];
  45 };
  46
  47 /*
  48  * Backend functions
  49  */
  50 static int netbsd_get_device_list(struct libusb_context *,
  51     struct discovered_devs **);
  52 static int netbsd_open(struct libusb_device_handle *);
  53 static void netbsd_close(struct libusb_device_handle *);
  54
  55 static int netbsd_get_device_descriptor(struct libusb_device *, unsigned char *,
  56     int *);
  57 static int netbsd_get_active_config_descriptor(struct libusb_device *,
  58     unsigned char *, size_t, int *);
  59 static int netbsd_get_config_descriptor(struct libusb_device *, uint8_t,
  60     unsigned char *, size_t, int *);
  61
  62 static int netbsd_get_configuration(struct libusb_device_handle *, int *);
  63 static int netbsd_set_configuration(struct libusb_device_handle *, int);
  64
  65 static int netbsd_claim_interface(struct libusb_device_handle *, int);
  66 static int netbsd_release_interface(struct libusb_device_handle *, int);
  67
  68 static int netbsd_set_interface_altsetting(struct libusb_device_handle *, int,
  69     int);
  70 static int netbsd_clear_halt(struct libusb_device_handle *, unsigned char);
  71 static int netbsd_reset_device(struct libusb_device_handle *);
  72 static void netbsd_destroy_device(struct libusb_device *);
  73
  74 static int netbsd_submit_transfer(struct usbi_transfer *);
  75 static int netbsd_cancel_transfer(struct usbi_transfer *);
  76 static void netbsd_clear_transfer_priv(struct usbi_transfer *);
  77 static int netbsd_handle_transfer_completion(struct usbi_transfer *);
  78 static int netbsd_clock_gettime(int, struct timespec *);
  79
  80 /*
  81  * Private functions
  82  */
  83 static int _errno_to_libusb(int);
  84 static int _cache_active_config_descriptor(struct libusb_device *, int);
  85 static int _sync_control_transfer(struct usbi_transfer *);
  86 static int _sync_gen_transfer(struct usbi_transfer *);
  87 static int _access_endpoint(struct libusb_transfer *);
  88
  89 const struct usbi_os_backend usbi_backend = {
  90         "Synchronous NetBSD backend",
  91         0,
  92         NULL,                           /* init() */
  93         NULL,                           /* exit() */
  94         NULL,                           /* set_option() */
  95         netbsd_get_device_list,
  96         NULL,                           /* hotplug_poll */
  97         netbsd_open,
  98         netbsd_close,
  99
 100         netbsd_get_device_descriptor,
 101         netbsd_get_active_config_descriptor,
 102         netbsd_get_config_descriptor,
 103         NULL,                           /* get_config_descriptor_by_value() */
 104
 105         netbsd_get_configuration,
 106         netbsd_set_configuration,
 107
 108         netbsd_claim_interface,
 109         netbsd_release_interface,
 110
 111         netbsd_set_interface_altsetting,
 112         netbsd_clear_halt,
 113         netbsd_reset_device,
 114
 115         NULL,                           /* alloc_streams */
 116         NULL,                           /* free_streams */
 117
 118         NULL,                           /* dev_mem_alloc() */
 119         NULL,                           /* dev_mem_free() */
 120
 121         NULL,                           /* kernel_driver_active() */
 122         NULL,                           /* detach_kernel_driver() */
 123         NULL,                           /* attach_kernel_driver() */
 124
 125         netbsd_destroy_device,
 126
 127         netbsd_submit_transfer,
 128         netbsd_cancel_transfer,
 129         netbsd_clear_transfer_priv,
 130
 131         NULL,                           /* handle_events() */
 132         netbsd_handle_transfer_completion,
 133
 134         netbsd_clock_gettime,
 135         0,                              /* context_priv_size */
 136         sizeof(struct device_priv),
 137         sizeof(struct handle_priv),
 138         0,                              /* transfer_priv_size */
 139 };
 140
 141 int
 142 netbsd_get_device_list(struct libusb_context * ctx,
 143         struct discovered_devs **discdevs)
 144 {
 145         struct libusb_device *dev;
 146         struct device_priv *dpriv;
 147         struct usb_device_info di;
 148         unsigned long session_id;
 149         char devnode[16];
 150         int fd, err, i;
 151
 152         usbi_dbg("");
 153
 154         /* Only ugen(4) is supported */
 155         for (i = 0; i < USB_MAX_DEVICES; i++) {
 156                 /* Control endpoint is always .00 */
 157                 snprintf(devnode, sizeof(devnode), "/dev/ugen%d.00", i);
 158
 159                 if ((fd = open(devnode, O_RDONLY)) < 0) {
 160                         if (errno != ENOENT && errno != ENXIO)
 161                                 usbi_err(ctx, "could not open %s", devnode);
 162                         continue;
 163                 }
 164
 165                 if (ioctl(fd, USB_GET_DEVICEINFO, &di) < 0)
 166                         continue;
 167
 168                 session_id = (di.udi_bus << 8 | di.udi_addr);
 169                 dev = usbi_get_device_by_session_id(ctx, session_id);
 170
 171                 if (dev == NULL) {
 172                         dev = usbi_alloc_device(ctx, session_id);
 173                         if (dev == NULL)
 174                                 return (LIBUSB_ERROR_NO_MEM);
 175
 176                         dev->bus_number = di.udi_bus;
 177                         dev->device_address = di.udi_addr;
 178                         dev->speed = di.udi_speed;
 179
 180                         dpriv = (struct device_priv *)dev->os_priv;
 181                         strlcpy(dpriv->devnode, devnode, sizeof(devnode));
 182                         dpriv->fd = -1;
 183
 184                         if (ioctl(fd, USB_GET_DEVICE_DESC, &dpriv->ddesc) < 0) {
 185                                 err = errno;
 186                                 goto error;
 187                         }
 188
 189                         dpriv->cdesc = NULL;
 190                         if (_cache_active_config_descriptor(dev, fd)) {
 191                                 err = errno;
 192                                 goto error;
 193                         }
 194
 195                         if ((err = usbi_sanitize_device(dev)))
 196                                 goto error;
 197                 }
 198                 close(fd);
 199
 200                 if (discovered_devs_append(*discdevs, dev) == NULL)
 201                         return (LIBUSB_ERROR_NO_MEM);
 202
 203                 libusb_unref_device(dev);
 204         }
 205
 206         return (LIBUSB_SUCCESS);
 207
 208 error:
 209         close(fd);
 210         libusb_unref_device(dev);
 211         return _errno_to_libusb(err);
 212 }
 213
 214 int
 215 netbsd_open(struct libusb_device_handle *handle)
 216 {
 217         struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
 218         struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 219
 220         dpriv->fd = open(dpriv->devnode, O_RDWR);
 221         if (dpriv->fd < 0) {
 222                 dpriv->fd = open(dpriv->devnode, O_RDONLY);
 223                 if (dpriv->fd < 0)
 224                         return _errno_to_libusb(errno);
 225         }
 226
 227         usbi_dbg("open %s: fd %d", dpriv->devnode, dpriv->fd);
 228
 229         return (LIBUSB_SUCCESS);
 230 }
 231
 232 void
 233 netbsd_close(struct libusb_device_handle *handle)
 234 {
 235         struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
 236         struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 237
 238         usbi_dbg("close: fd %d", dpriv->fd);
 239
 240         close(dpriv->fd);
 241         dpriv->fd = -1;
 242 }
 243
 244 int
 245 netbsd_get_device_descriptor(struct libusb_device *dev, unsigned char *buf,
 246     int *host_endian)
 247 {
 248         struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
 249
 250         usbi_dbg("");
 251
 252         memcpy(buf, &dpriv->ddesc, DEVICE_DESC_LENGTH);
 253
 254         *host_endian = 0;
 255
 256         return (LIBUSB_SUCCESS);
 257 }
 258
 259 int
 260 netbsd_get_active_config_descriptor(struct libusb_device *dev,
 261     unsigned char *buf, size_t len, int *host_endian)
 262 {
 263         struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
 264         usb_config_descriptor_t *ucd;
 265
 266         ucd = (usb_config_descriptor_t *) dpriv->cdesc;
 267         len = MIN(len, UGETW(ucd->wTotalLength));
 268
 269         usbi_dbg("len %d", len);
 270
 271         memcpy(buf, dpriv->cdesc, len);
 272
 273         *host_endian = 0;
 274
 275         return len;
 276 }
 277
 278 int
 279 netbsd_get_config_descriptor(struct libusb_device *dev, uint8_t idx,
 280     unsigned char *buf, size_t len, int *host_endian)
 281 {
 282         struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
 283         struct usb_full_desc ufd;
 284         int fd, err;
 285
 286         usbi_dbg("index %d, len %d", idx, len);
 287
 288         /* A config descriptor may be requested before opening the device */
 289         if (dpriv->fd >= 0) {
 290                 fd = dpriv->fd;
 291         } else {
 292                 fd = open(dpriv->devnode, O_RDONLY);
 293                 if (fd < 0)
 294                         return _errno_to_libusb(errno);
 295         }
 296
 297         ufd.ufd_config_index = idx;
 298         ufd.ufd_size = len;
 299         ufd.ufd_data = buf;
 300
 301         if ((ioctl(fd, USB_GET_FULL_DESC, &ufd)) < 0) {
 302                 err = errno;
 303                 if (dpriv->fd < 0)
 304                         close(fd);
 305                 return _errno_to_libusb(err);
 306         }
 307
 308         if (dpriv->fd < 0)
 309                 close(fd);
 310
 311         *host_endian = 0;
 312
 313         return len;
 314 }
 315
 316 int
 317 netbsd_get_configuration(struct libusb_device_handle *handle, int *config)
 318 {
 319         struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 320
 321         usbi_dbg("");
 322
 323         if (ioctl(dpriv->fd, USB_GET_CONFIG, config) < 0)
 324                 return _errno_to_libusb(errno);
 325
 326         usbi_dbg("configuration %d", *config);
 327
 328         return (LIBUSB_SUCCESS);
 329 }
 330
 331 int
 332 netbsd_set_configuration(struct libusb_device_handle *handle, int config)
 333 {
 334         struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 335
 336         usbi_dbg("configuration %d", config);
 337
 338         if (ioctl(dpriv->fd, USB_SET_CONFIG, &config) < 0)
 339                 return _errno_to_libusb(errno);
 340
 341         return _cache_active_config_descriptor(handle->dev, dpriv->fd);
 342 }
 343
 344 int
 345 netbsd_claim_interface(struct libusb_device_handle *handle, int iface)
 346 {
 347         struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
 348         int i;
 349
 350         for (i = 0; i < USB_MAX_ENDPOINTS; i++)
 351                 hpriv->endpoints[i] = -1;
 352
 353         return (LIBUSB_SUCCESS);
 354 }
 355
 356 int
 357 netbsd_release_interface(struct libusb_device_handle *handle, int iface)
 358 {
 359         struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
 360         int i;
 361
 362         for (i = 0; i < USB_MAX_ENDPOINTS; i++)
 363                 if (hpriv->endpoints[i] >= 0)
 364                         close(hpriv->endpoints[i]);
 365
 366         return (LIBUSB_SUCCESS);
 367 }
 368
 369 int
 370 netbsd_set_interface_altsetting(struct libusb_device_handle *handle, int iface,
 371     int altsetting)
 372 {
 373         struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 374         struct usb_alt_interface intf;
 375
 376         usbi_dbg("iface %d, setting %d", iface, altsetting);
 377
 378         memset(&intf, 0, sizeof(intf));
 379
 380         intf.uai_interface_index = iface;
 381         intf.uai_alt_no = altsetting;
 382
 383         if (ioctl(dpriv->fd, USB_SET_ALTINTERFACE, &intf) < 0)
 384                 return _errno_to_libusb(errno);
 385
 386         return (LIBUSB_SUCCESS);
 387 }
 388
 389 int
 390 netbsd_clear_halt(struct libusb_device_handle *handle, unsigned char endpoint)
 391 {
 392         struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
 393         struct usb_ctl_request req;
 394
 395         usbi_dbg("");
 396
 397         req.ucr_request.bmRequestType = UT_WRITE_ENDPOINT;
 398         req.ucr_request.bRequest = UR_CLEAR_FEATURE;
 399         USETW(req.ucr_request.wValue, UF_ENDPOINT_HALT);
 400         USETW(req.ucr_request.wIndex, endpoint);
 401         USETW(req.ucr_request.wLength, 0);
 402
 403         if (ioctl(dpriv->fd, USB_DO_REQUEST, &req) < 0)
 404                 return _errno_to_libusb(errno);
 405
 406         return (LIBUSB_SUCCESS);
 407 }
 408
 409 int
 410 netbsd_reset_device(struct libusb_device_handle *handle)
 411 {
 412         usbi_dbg("");
 413
 414         return (LIBUSB_ERROR_NOT_SUPPORTED);
 415 }
 416
 417 void
 418 netbsd_destroy_device(struct libusb_device *dev)
 419 {
 420         struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
 421
 422         usbi_dbg("");
 423
 424         free(dpriv->cdesc);
 425 }
 426
 427 int
 428 netbsd_submit_transfer(struct usbi_transfer *itransfer)
 429 {
 430         struct libusb_transfer *transfer;
 431         struct handle_priv *hpriv;
 432         int err = 0;
 433
 434         usbi_dbg("");
 435
 436         transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 437         hpriv = (struct handle_priv *)transfer->dev_handle->os_priv;
 438
 439         switch (transfer->type) {
 440         case LIBUSB_TRANSFER_TYPE_CONTROL:
 441                 err = _sync_control_transfer(itransfer);
 442                 break;
 443         case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
 444                 if (IS_XFEROUT(transfer)) {
 445                         /* Isochronous write is not supported */
 446                         err = LIBUSB_ERROR_NOT_SUPPORTED;
 447                         break;
 448                 }
 449                 err = _sync_gen_transfer(itransfer);
 450                 break;
 451         case LIBUSB_TRANSFER_TYPE_BULK:
 452         case LIBUSB_TRANSFER_TYPE_INTERRUPT:
 453                 if (IS_XFEROUT(transfer) &&
 454                     transfer->flags & LIBUSB_TRANSFER_ADD_ZERO_PACKET) {
 455                         err = LIBUSB_ERROR_NOT_SUPPORTED;
 456                         break;
 457                 }
 458                 err = _sync_gen_transfer(itransfer);
 459                 break;
 460         case LIBUSB_TRANSFER_TYPE_BULK_STREAM:
 461                 err = LIBUSB_ERROR_NOT_SUPPORTED;
 462                 break;
 463         }
 464
 465         if (err)
 466                 return (err);
 467
 468         usbi_signal_transfer_completion(itransfer);
 469
 470         return (LIBUSB_SUCCESS);
 471 }
 472
 473 int
 474 netbsd_cancel_transfer(struct usbi_transfer *itransfer)
 475 {
 476         usbi_dbg("");
 477
 478         return (LIBUSB_ERROR_NOT_SUPPORTED);
 479 }
 480
 481 void
 482 netbsd_clear_transfer_priv(struct usbi_transfer *itransfer)
 483 {
 484         usbi_dbg("");
 485
 486         /* Nothing to do */
 487 }
 488
 489 int
 490 netbsd_handle_transfer_completion(struct usbi_transfer *itransfer)
 491 {
 492         return usbi_handle_transfer_completion(itransfer, LIBUSB_TRANSFER_COMPLETED);
 493 }
 494
 495 int
 496 netbsd_clock_gettime(int clkid, struct timespec *tp)
 497 {
 498         usbi_dbg("clock %d", clkid);
 499
 500         if (clkid == USBI_CLOCK_REALTIME)
 501                 return clock_gettime(CLOCK_REALTIME, tp);
 502
 503         if (clkid == USBI_CLOCK_MONOTONIC)
 504                 return clock_gettime(CLOCK_MONOTONIC, tp);
 505
 506         return (LIBUSB_ERROR_INVALID_PARAM);
 507 }
 508
 509 int
 510 _errno_to_libusb(int err)
 511 {
 512         switch (err) {
 513         case EIO:
 514                 return (LIBUSB_ERROR_IO);
 515         case EACCES:
 516                 return (LIBUSB_ERROR_ACCESS);
 517         case ENOENT:
 518                 return (LIBUSB_ERROR_NO_DEVICE);
 519         case ENOMEM:
 520                 return (LIBUSB_ERROR_NO_MEM);
 521         }
 522
 523         usbi_dbg("error: %s", strerror(err));
 524
 525         return (LIBUSB_ERROR_OTHER);
 526 }
 527
 528 int
 529 _cache_active_config_descriptor(struct libusb_device *dev, int fd)
 530 {
 531         struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
 532         struct usb_config_desc ucd;
 533         struct usb_full_desc ufd;
 534         unsigned char* buf;
 535         int len;
 536
 537         usbi_dbg("fd %d", fd);
 538
 539         ucd.ucd_config_index = USB_CURRENT_CONFIG_INDEX;
 540
 541         if ((ioctl(fd, USB_GET_CONFIG_DESC, &ucd)) < 0)
 542                 return _errno_to_libusb(errno);
 543
 544         usbi_dbg("active bLength %d", ucd.ucd_desc.bLength);
 545
 546         len = UGETW(ucd.ucd_desc.wTotalLength);
 547         buf = malloc(len);
 548         if (buf == NULL)
 549                 return (LIBUSB_ERROR_NO_MEM);
 550
 551         ufd.ufd_config_index = ucd.ucd_config_index;
 552         ufd.ufd_size = len;
 553         ufd.ufd_data = buf;
 554
 555         usbi_dbg("index %d, len %d", ufd.ufd_config_index, len);
 556
 557         if ((ioctl(fd, USB_GET_FULL_DESC, &ufd)) < 0) {
 558                 free(buf);
 559                 return _errno_to_libusb(errno);
 560         }
 561
 562         if (dpriv->cdesc)
 563                 free(dpriv->cdesc);
 564         dpriv->cdesc = buf;
 565
 566         return (0);
 567 }
 568
 569 int
 570 _sync_control_transfer(struct usbi_transfer *itransfer)
 571 {
 572         struct libusb_transfer *transfer;
 573         struct libusb_control_setup *setup;
 574         struct device_priv *dpriv;
 575         struct usb_ctl_request req;
 576
 577         transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 578         dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
 579         setup = (struct libusb_control_setup *)transfer->buffer;
 580
 581         usbi_dbg("type %d request %d value %d index %d length %d timeout %d",
 582             setup->bmRequestType, setup->bRequest,
 583             libusb_le16_to_cpu(setup->wValue),
 584             libusb_le16_to_cpu(setup->wIndex),
 585             libusb_le16_to_cpu(setup->wLength), transfer->timeout);
 586
 587         req.ucr_request.bmRequestType = setup->bmRequestType;
 588         req.ucr_request.bRequest = setup->bRequest;
 589         /* Don't use USETW, libusb already deals with the endianness */
 590         (*(uint16_t *)req.ucr_request.wValue) = setup->wValue;
 591         (*(uint16_t *)req.ucr_request.wIndex) = setup->wIndex;
 592         (*(uint16_t *)req.ucr_request.wLength) = setup->wLength;
 593         req.ucr_data = transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE;
 594
 595         if ((transfer->flags & LIBUSB_TRANSFER_SHORT_NOT_OK) == 0)
 596                 req.ucr_flags = USBD_SHORT_XFER_OK;
 597
 598         if ((ioctl(dpriv->fd, USB_SET_TIMEOUT, &transfer->timeout)) < 0)
 599                 return _errno_to_libusb(errno);
 600
 601         if ((ioctl(dpriv->fd, USB_DO_REQUEST, &req)) < 0)
 602                 return _errno_to_libusb(errno);
 603
 604         itransfer->transferred = req.ucr_actlen;
 605
 606         usbi_dbg("transferred %d", itransfer->transferred);
 607
 608         return (0);
 609 }
 610
 611 int
 612 _access_endpoint(struct libusb_transfer *transfer)
 613 {
 614         struct handle_priv *hpriv;
 615         struct device_priv *dpriv;
 616         char *s, devnode[16];
 617         int fd, endpt;
 618         mode_t mode;
 619
 620         hpriv = (struct handle_priv *)transfer->dev_handle->os_priv;
 621         dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
 622
 623         endpt = UE_GET_ADDR(transfer->endpoint);
 624         mode = IS_XFERIN(transfer) ? O_RDONLY : O_WRONLY;
 625
 626         usbi_dbg("endpoint %d mode %d", endpt, mode);
 627
 628         if (hpriv->endpoints[endpt] < 0) {
 629                 /* Pick the right node given the control one */
 630                 strlcpy(devnode, dpriv->devnode, sizeof(devnode));
 631                 s = strchr(devnode, '.');
 632                 snprintf(s, 4, ".%02d", endpt);
 633
 634                 /* We may need to read/write to the same endpoint later. */
 635                 if (((fd = open(devnode, O_RDWR)) < 0) && (errno == ENXIO))
 636                         if ((fd = open(devnode, mode)) < 0)
 637                                 return (-1);
 638
 639                 hpriv->endpoints[endpt] = fd;
 640         }
 641
 642         return (hpriv->endpoints[endpt]);
 643 }
 644
 645 int
 646 _sync_gen_transfer(struct usbi_transfer *itransfer)
 647 {
 648         struct libusb_transfer *transfer;
 649         int fd, nr = 1;
 650
 651         transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
 652
 653         /*
 654          * Bulk, Interrupt or Isochronous transfer depends on the
 655          * endpoint and thus the node to open.
 656          */
 657         if ((fd = _access_endpoint(transfer)) < 0)
 658                 return _errno_to_libusb(errno);
 659
 660         if ((ioctl(fd, USB_SET_TIMEOUT, &transfer->timeout)) < 0)
 661                 return _errno_to_libusb(errno);
 662
 663         if (IS_XFERIN(transfer)) {
 664                 if ((transfer->flags & LIBUSB_TRANSFER_SHORT_NOT_OK) == 0)
 665                         if ((ioctl(fd, USB_SET_SHORT_XFER, &nr)) < 0)
 666                                 return _errno_to_libusb(errno);
 667
 668                 nr = read(fd, transfer->buffer, transfer->length);
 669         } else {
 670                 nr = write(fd, transfer->buffer, transfer->length);
 671         }
 672
 673         if (nr < 0)
 674                 return _errno_to_libusb(errno);
 675
 676         itransfer->transferred = nr;
 677
 678         return (0);
 679 }