text: /*
   * Copyright © 2011-2013 Martin Pieuchot <mpi@openbsd.org>
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include <sys/time.h>
  #include <sys/types.h>
  
  #include <errno.h>
  #include <fcntl.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #include <dev/usb/usb.h>
  
  #include "libusb.h"
  #include "libusbi.h"
  
  struct device_priv {
  	char *devname;				/* name of the ugen(4) node */
  	int fd;					/* device file descriptor */
  
  	unsigned char *cdesc;			/* active config descriptor */
  	usb_device_descriptor_t ddesc;		/* usb device descriptor */
  };
  
  struct handle_priv {
  	int pipe[2];				/* for event notification */
  	int endpoints[USB_MAX_ENDPOINTS];
  };
  
  /*
   * Backend functions
   */
  static int obsd_get_device_list(struct libusb_context *,
      struct discovered_devs **);
  static int obsd_open(struct libusb_device_handle *);
  static void obsd_close(struct libusb_device_handle *);
  
  static int obsd_get_device_descriptor(struct libusb_device *, unsigned char *,
      int *);
  static int obsd_get_active_config_descriptor(struct libusb_device *,
      unsigned char *, size_t, int *);
  static int obsd_get_config_descriptor(struct libusb_device *, uint8_t,
      unsigned char *, size_t, int *);
  
  static int obsd_get_configuration(struct libusb_device_handle *, int *);
  static int obsd_set_configuration(struct libusb_device_handle *, int);
  
  static int obsd_claim_interface(struct libusb_device_handle *, int);
  static int obsd_release_interface(struct libusb_device_handle *, int);
  
  static int obsd_set_interface_altsetting(struct libusb_device_handle *, int,
      int);
  static int obsd_clear_halt(struct libusb_device_handle *, unsigned char);
  static int obsd_reset_device(struct libusb_device_handle *);
  static void obsd_destroy_device(struct libusb_device *);
  
  static int obsd_submit_transfer(struct usbi_transfer *);
  static int obsd_cancel_transfer(struct usbi_transfer *);
  static void obsd_clear_transfer_priv(struct usbi_transfer *);
  static int obsd_handle_events(struct libusb_context *ctx, struct pollfd *,
      nfds_t, int);
  static int obsd_clock_gettime(int, struct timespec *);
  
  /*
   * Private functions
   */
  static int _errno_to_libusb(int);
  static int _cache_active_config_descriptor(struct libusb_device *);
  static int _sync_control_transfer(struct usbi_transfer *);
  static int _sync_gen_transfer(struct usbi_transfer *);
  static int _access_endpoint(struct libusb_transfer *);
  
  static int _bus_open(int);
  
  
  const struct usbi_os_backend openbsd_backend = {
  	"Synchronous OpenBSD backend",
  	USBI_CAP_HAS_POLLABLE_DEVICE_FD,
  	NULL,				/* init() */
  	NULL,				/* exit() */
  	obsd_get_device_list,
  	NULL,				/* hotplug_poll */
  	obsd_open,
  	obsd_close,
  
  	obsd_get_device_descriptor,
  	obsd_get_active_config_descriptor,
  	obsd_get_config_descriptor,
  	NULL,				/* get_config_descriptor_by_value() */
  
  	obsd_get_configuration,
  	obsd_set_configuration,
  
  	obsd_claim_interface,
  	obsd_release_interface,
  
  	obsd_set_interface_altsetting,
  	obsd_clear_halt,
  	obsd_reset_device,
  
  	NULL,				/* alloc_streams */
  	NULL,				/* free_streams */
  
  	NULL,				/* kernel_driver_active() */
  	NULL,				/* detach_kernel_driver() */
  	NULL,				/* attach_kernel_driver() */
  
  	obsd_destroy_device,
  
  	obsd_submit_transfer,
  	obsd_cancel_transfer,
  	obsd_clear_transfer_priv,
  
  	obsd_handle_events,
  
  	obsd_clock_gettime,
  	sizeof(struct device_priv),
  	sizeof(struct handle_priv),
  	0,				/* transfer_priv_size */
  	0,				/* add_iso_packet_size */
  };
  
  #define DEVPATH	"/dev/"
  #define USBDEV	DEVPATH "usb"
  
  int
  obsd_get_device_list(struct libusb_context * ctx,
  	struct discovered_devs **discdevs)
  {
  	struct discovered_devs *ddd;
  	struct libusb_device *dev;
  	struct device_priv *dpriv;
  	struct usb_device_info di;
  	struct usb_device_ddesc dd;
  	unsigned long session_id;
  	char devices[USB_MAX_DEVICES];
  	char busnode[16];
  	char *udevname;
  	int fd, addr, i, j;
  
  	usbi_dbg("");
  
  	for (i = 0; i < 8; i++) {
  		snprintf(busnode, sizeof(busnode), USBDEV "%d", i);
  
  		if ((fd = open(busnode, O_RDWR)) < 0) {
  			if (errno != ENOENT && errno != ENXIO)
  				usbi_err(ctx, "could not open %s", busnode);
  			continue;
  		}
  
  		bzero(devices, sizeof(devices));
  		for (addr = 1; addr < USB_MAX_DEVICES; addr++) {
  			if (devices[addr])
  				continue;
  
  			di.udi_addr = addr;
  			if (ioctl(fd, USB_DEVICEINFO, &di) < 0)
  				continue;
  
  			/*
  			 * XXX If ugen(4) is attached to the USB device
  			 * it will be used.
  			 */
  			udevname = NULL;
  			for (j = 0; j < USB_MAX_DEVNAMES; j++)
  				if (!strncmp("ugen", di.udi_devnames[j], 4)) {
  					udevname = strdup(di.udi_devnames[j]);
  					break;
  				}
  
  			session_id = (di.udi_bus << 8 | di.udi_addr);
  			dev = usbi_get_device_by_session_id(ctx, session_id);
  
  			if (dev == NULL) {
  				dev = usbi_alloc_device(ctx, session_id);
  				if (dev == NULL) {
  					close(fd);
  					return (LIBUSB_ERROR_NO_MEM);
  				}
  
  				dev->bus_number = di.udi_bus;
  				dev->device_address = di.udi_addr;
  				dev->speed = di.udi_speed;
  
  				dpriv = (struct device_priv *)dev->os_priv;
  				dpriv->fd = -1;
  				dpriv->cdesc = NULL;
  				dpriv->devname = udevname;
  
  				dd.udd_bus = di.udi_bus;
  				dd.udd_addr = di.udi_addr;
  				if (ioctl(fd, USB_DEVICE_GET_DDESC, &dd) < 0) {
  					libusb_unref_device(dev);
  					continue;
  				}
  				dpriv->ddesc = dd.udd_desc;
  
  				if (_cache_active_config_descriptor(dev)) {
  					libusb_unref_device(dev);
  					continue;
  				}
  
  				if (usbi_sanitize_device(dev)) {
  					libusb_unref_device(dev);
  					continue;
  				}
  			}
  
  			ddd = discovered_devs_append(*discdevs, dev);
  			if (ddd == NULL) {
  				close(fd);
  				return (LIBUSB_ERROR_NO_MEM);
  			}
  			libusb_unref_device(dev);
  
  			*discdevs = ddd;
  			devices[addr] = 1;
  		}
  
  		close(fd);
  	}
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  obsd_open(struct libusb_device_handle *handle)
  {
  	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
  	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
  	char devnode[16];
  
  	if (dpriv->devname) {
  		/*
  		 * Only open ugen(4) attached devices read-write, all
  		 * read-only operations are done through the bus node.
  		 */
  		snprintf(devnode, sizeof(devnode), DEVPATH "%s.00",
  		    dpriv->devname);
  		dpriv->fd = open(devnode, O_RDWR);
  		if (dpriv->fd < 0)
  			return _errno_to_libusb(errno);
  
  		usbi_dbg("open %s: fd %d", devnode, dpriv->fd);
  	}
  
  	if (pipe(hpriv->pipe) < 0)
  		return _errno_to_libusb(errno);
  
  	return usbi_add_pollfd(HANDLE_CTX(handle), hpriv->pipe[0], POLLIN);
  }
  
  void
  obsd_close(struct libusb_device_handle *handle)
  {
  	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
  	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
  
  	if (dpriv->devname) {
  		usbi_dbg("close: fd %d", dpriv->fd);
  
  		close(dpriv->fd);
  		dpriv->fd = -1;
  	}
  
  	usbi_remove_pollfd(HANDLE_CTX(handle), hpriv->pipe[0]);
  
  	close(hpriv->pipe[0]);
  	close(hpriv->pipe[1]);
  }
  
  int
  obsd_get_device_descriptor(struct libusb_device *dev, unsigned char *buf,
      int *host_endian)
  {
  	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
  
  	usbi_dbg("");
  
  	memcpy(buf, &dpriv->ddesc, DEVICE_DESC_LENGTH);
  
  	*host_endian = 0;
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  obsd_get_active_config_descriptor(struct libusb_device *dev,
      unsigned char *buf, size_t len, int *host_endian)
  {
  	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
  	usb_config_descriptor_t *ucd = (usb_config_descriptor_t *)dpriv->cdesc;
  
  	len = MIN(len, UGETW(ucd->wTotalLength));
  
  	usbi_dbg("len %d", len);
  
  	memcpy(buf, dpriv->cdesc, len);
  
  	*host_endian = 0;
  
  	return (len);
  }
  
  int
  obsd_get_config_descriptor(struct libusb_device *dev, uint8_t idx,
      unsigned char *buf, size_t len, int *host_endian)
  {
  	struct usb_device_fdesc udf;
  	int fd, err;
  
  	if ((fd = _bus_open(dev->bus_number)) < 0)
  		return _errno_to_libusb(errno);
  
  	udf.udf_bus = dev->bus_number;
  	udf.udf_addr = dev->device_address;
  	udf.udf_config_index = idx;
  	udf.udf_size = len;
  	udf.udf_data = buf;
  
  	usbi_dbg("index %d, len %d", udf.udf_config_index, len);
  
  	if (ioctl(fd, USB_DEVICE_GET_FDESC, &udf) < 0) {
  		err = errno;
  		close(fd);
  		return _errno_to_libusb(err);
  	}
  	close(fd);
  
  	*host_endian = 0;
  
  	return (len);
  }
  
  int
  obsd_get_configuration(struct libusb_device_handle *handle, int *config)
  {
  	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
  	usb_config_descriptor_t *ucd = (usb_config_descriptor_t *)dpriv->cdesc;
  
  	*config = ucd->bConfigurationValue;
  
  	usbi_dbg("bConfigurationValue %d", *config);
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  obsd_set_configuration(struct libusb_device_handle *handle, int config)
  {
  	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
  
  	if (dpriv->devname == NULL)
  		return (LIBUSB_ERROR_NOT_SUPPORTED);
  
  	usbi_dbg("bConfigurationValue %d", config);
  
  	if (ioctl(dpriv->fd, USB_SET_CONFIG, &config) < 0)
  		return _errno_to_libusb(errno);
  
  	return _cache_active_config_descriptor(handle->dev);
  }
  
  int
  obsd_claim_interface(struct libusb_device_handle *handle, int iface)
  {
  	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
  	int i;
  
  	for (i = 0; i < USB_MAX_ENDPOINTS; i++)
  		hpriv->endpoints[i] = -1;
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  obsd_release_interface(struct libusb_device_handle *handle, int iface)
  {
  	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
  	int i;
  
  	for (i = 0; i < USB_MAX_ENDPOINTS; i++)
  		if (hpriv->endpoints[i] >= 0)
  			close(hpriv->endpoints[i]);
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  obsd_set_interface_altsetting(struct libusb_device_handle *handle, int iface,
      int altsetting)
  {
  	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
  	struct usb_alt_interface intf;
  
  	if (dpriv->devname == NULL)
  		return (LIBUSB_ERROR_NOT_SUPPORTED);
  
  	usbi_dbg("iface %d, setting %d", iface, altsetting);
  
  	memset(&intf, 0, sizeof(intf));
  
  	intf.uai_interface_index = iface;
  	intf.uai_alt_no = altsetting;
  
  	if (ioctl(dpriv->fd, USB_SET_ALTINTERFACE, &intf) < 0)
  		return _errno_to_libusb(errno);
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  obsd_clear_halt(struct libusb_device_handle *handle, unsigned char endpoint)
  {
  	struct usb_ctl_request req;
  	int fd, err;
  
  	if ((fd = _bus_open(handle->dev->bus_number)) < 0)
  		return _errno_to_libusb(errno);
  
  	usbi_dbg("");
  
  	req.ucr_addr = handle->dev->device_address;
  	req.ucr_request.bmRequestType = UT_WRITE_ENDPOINT;
  	req.ucr_request.bRequest = UR_CLEAR_FEATURE;
  	USETW(req.ucr_request.wValue, UF_ENDPOINT_HALT);
  	USETW(req.ucr_request.wIndex, endpoint);
  	USETW(req.ucr_request.wLength, 0);
  
  	if (ioctl(fd, USB_REQUEST, &req) < 0) {
  		err = errno;
  		close(fd);
  		return _errno_to_libusb(err);
  	}
  	close(fd);
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  obsd_reset_device(struct libusb_device_handle *handle)
  {
  	usbi_dbg("");
  
  	return (LIBUSB_ERROR_NOT_SUPPORTED);
  }
  
  void
  obsd_destroy_device(struct libusb_device *dev)
  {
  	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
  
  	usbi_dbg("");
  
  	free(dpriv->cdesc);
  	free(dpriv->devname);
  }
  
  int
  obsd_submit_transfer(struct usbi_transfer *itransfer)
  {
  	struct libusb_transfer *transfer;
  	struct handle_priv *hpriv;
  	int err = 0;
  
  	usbi_dbg("");
  
  	transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
  	hpriv = (struct handle_priv *)transfer->dev_handle->os_priv;
  
  	switch (transfer->type) {
  	case LIBUSB_TRANSFER_TYPE_CONTROL:
  		err = _sync_control_transfer(itransfer);
  		break;
  	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
  		if (IS_XFEROUT(transfer)) {
  			/* Isochronous write is not supported */
  			err = LIBUSB_ERROR_NOT_SUPPORTED;
  			break;
  		}
  		err = _sync_gen_transfer(itransfer);
  		break;
  	case LIBUSB_TRANSFER_TYPE_BULK:
  	case LIBUSB_TRANSFER_TYPE_INTERRUPT:
  		if (IS_XFEROUT(transfer) &&
  		    transfer->flags & LIBUSB_TRANSFER_ADD_ZERO_PACKET) {
  			err = LIBUSB_ERROR_NOT_SUPPORTED;
  			break;
  		}
  		err = _sync_gen_transfer(itransfer);
  		break;
  	case LIBUSB_TRANSFER_TYPE_BULK_STREAM:
  		err = LIBUSB_ERROR_NOT_SUPPORTED;
  		break;
  	}
  
  	if (err)
  		return (err);
  
  	if (write(hpriv->pipe[1], &itransfer, sizeof(itransfer)) < 0)
  		return _errno_to_libusb(errno);
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  obsd_cancel_transfer(struct usbi_transfer *itransfer)
  {
  	usbi_dbg("");
  
  	return (LIBUSB_ERROR_NOT_SUPPORTED);
  }
  
  void
  obsd_clear_transfer_priv(struct usbi_transfer *itransfer)
  {
  	usbi_dbg("");
  
  	/* Nothing to do */
  }
  
  int
  obsd_handle_events(struct libusb_context *ctx, struct pollfd *fds, nfds_t nfds,
      int num_ready)
  {
  	struct libusb_device_handle *handle;
  	struct handle_priv *hpriv = NULL;
  	struct usbi_transfer *itransfer;
  	struct pollfd *pollfd;
  	int i, err = 0;
  
  	usbi_dbg("");
  
  	pthread_mutex_lock(&ctx->open_devs_lock);
  	for (i = 0; i < nfds && num_ready > 0; i++) {
  		pollfd = &fds[i];
  
  		if (!pollfd->revents)
  			continue;
  
  		hpriv = NULL;
  		num_ready--;
  		list_for_each_entry(handle, &ctx->open_devs, list,
  		    struct libusb_device_handle) {
  			hpriv = (struct handle_priv *)handle->os_priv;
  
  			if (hpriv->pipe[0] == pollfd->fd)
  				break;
  
  			hpriv = NULL;
  		}
  
  		if (NULL == hpriv) {
  			usbi_dbg("fd %d is not an event pipe!", pollfd->fd);
  			err = ENOENT;
  			break;
  		}
  
  		if (pollfd->revents & POLLERR) {
  			usbi_remove_pollfd(HANDLE_CTX(handle), hpriv->pipe[0]);
  			usbi_handle_disconnect(handle);
  			continue;
  		}
  
  		if (read(hpriv->pipe[0], &itransfer, sizeof(itransfer)) < 0) {
  			err = errno;
  			break;
  		}
  
  		if ((err = usbi_handle_transfer_completion(itransfer,
  		    LIBUSB_TRANSFER_COMPLETED)))
  			break;
  	}
  	pthread_mutex_unlock(&ctx->open_devs_lock);
  
  	if (err)
  		return _errno_to_libusb(err);
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  obsd_clock_gettime(int clkid, struct timespec *tp)
  {
  	usbi_dbg("clock %d", clkid);
  
  	if (clkid == USBI_CLOCK_REALTIME)
  		return clock_gettime(CLOCK_REALTIME, tp);
  
  	if (clkid == USBI_CLOCK_MONOTONIC)
  		return clock_gettime(CLOCK_MONOTONIC, tp);
  
  	return (LIBUSB_ERROR_INVALID_PARAM);
  }
  
  int
  _errno_to_libusb(int err)
  {
  	usbi_dbg("error: %s (%d)", strerror(err), err);
  
  	switch (err) {
  	case EIO:
  		return (LIBUSB_ERROR_IO);
  	case EACCES:
  		return (LIBUSB_ERROR_ACCESS);
  	case ENOENT:
  		return (LIBUSB_ERROR_NO_DEVICE);
  	case ENOMEM:
  		return (LIBUSB_ERROR_NO_MEM);
  	case ETIMEDOUT:
  		return (LIBUSB_ERROR_TIMEOUT);
  	}
  
  	return (LIBUSB_ERROR_OTHER);
  }
  
  int
  _cache_active_config_descriptor(struct libusb_device *dev)
  {
  	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
  	struct usb_device_cdesc udc;
  	struct usb_device_fdesc udf;
  	unsigned char* buf;
  	int fd, len, err;
  
  	if ((fd = _bus_open(dev->bus_number)) < 0)
  		return _errno_to_libusb(errno);
  
  	usbi_dbg("fd %d, addr %d", fd, dev->device_address);
  
  	udc.udc_bus = dev->bus_number;
  	udc.udc_addr = dev->device_address;
  	udc.udc_config_index = USB_CURRENT_CONFIG_INDEX;
  	if (ioctl(fd, USB_DEVICE_GET_CDESC, &udc) < 0) {
  		err = errno;
  		close(fd);
  		return _errno_to_libusb(errno);
  	}
  
  	usbi_dbg("active bLength %d", udc.udc_desc.bLength);
  
  	len = UGETW(udc.udc_desc.wTotalLength);
  	buf = malloc(len);
  	if (buf == NULL)
  		return (LIBUSB_ERROR_NO_MEM);
  
  	udf.udf_bus = dev->bus_number;
  	udf.udf_addr = dev->device_address;
  	udf.udf_config_index = udc.udc_config_index;
  	udf.udf_size = len;
  	udf.udf_data = buf;
  
  	usbi_dbg("index %d, len %d", udf.udf_config_index, len);
  
  	if (ioctl(fd, USB_DEVICE_GET_FDESC, &udf) < 0) {
  		err = errno;
  		close(fd);
  		free(buf);
  		return _errno_to_libusb(err);
  	}
  	close(fd);
  
  	if (dpriv->cdesc)
  		free(dpriv->cdesc);
  	dpriv->cdesc = buf;
  
  	return (LIBUSB_SUCCESS);
  }
  
  int
  _sync_control_transfer(struct usbi_transfer *itransfer)
  {
  	struct libusb_transfer *transfer;
  	struct libusb_control_setup *setup;
  	struct device_priv *dpriv;
  	struct usb_ctl_request req;
  
  	transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
  	dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
  	setup = (struct libusb_control_setup *)transfer->buffer;
  
  	usbi_dbg("type %x request %x value %x index %d length %d timeout %d",
  	    setup->bmRequestType, setup->bRequest,
  	    libusb_le16_to_cpu(setup->wValue),
  	    libusb_le16_to_cpu(setup->wIndex),
  	    libusb_le16_to_cpu(setup->wLength), transfer->timeout);
  
  	req.ucr_addr = transfer->dev_handle->dev->device_address;
  	req.ucr_request.bmRequestType = setup->bmRequestType;
  	req.ucr_request.bRequest = setup->bRequest;
  	/* Don't use USETW, libusb already deals with the endianness */
  	(*(uint16_t *)req.ucr_request.wValue) = setup->wValue;
  	(*(uint16_t *)req.ucr_request.wIndex) = setup->wIndex;
  	(*(uint16_t *)req.ucr_request.wLength) = setup->wLength;
  	req.ucr_data = transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE;
  
  	if ((transfer->flags & LIBUSB_TRANSFER_SHORT_NOT_OK) == 0)
  		req.ucr_flags = USBD_SHORT_XFER_OK;
  
  	if (dpriv->devname == NULL) {
  		/*
  		 * XXX If the device is not attached to ugen(4) it is
  		 * XXX still possible to submit a control transfer but
  		 * XXX with the default timeout only.
  		 */
  		int fd, err;
  
  		if ((fd = _bus_open(transfer->dev_handle->dev->bus_number)) < 0)
  			return _errno_to_libusb(errno);
  
  		if ((ioctl(fd, USB_REQUEST, &req)) < 0) {
  			err = errno;
  			close(fd);
  			return _errno_to_libusb(err);
  		}
  		close(fd);
  	} else {
  		if ((ioctl(dpriv->fd, USB_SET_TIMEOUT, &transfer->timeout)) < 0)
  			return _errno_to_libusb(errno);
  
  		if ((ioctl(dpriv->fd, USB_DO_REQUEST, &req)) < 0)
  			return _errno_to_libusb(errno);
  	}
  
  	itransfer->transferred = req.ucr_actlen;
  
  	usbi_dbg("transferred %d", itransfer->transferred);
  
  	return (0);
  }
  
  int
  _access_endpoint(struct libusb_transfer *transfer)
  {
  	struct handle_priv *hpriv;
  	struct device_priv *dpriv;
  	char devnode[16];
  	int fd, endpt;
  	mode_t mode;
  
  	hpriv = (struct handle_priv *)transfer->dev_handle->os_priv;
  	dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
  
  	endpt = UE_GET_ADDR(transfer->endpoint);
  	mode = IS_XFERIN(transfer) ? O_RDONLY : O_WRONLY;
  
  	usbi_dbg("endpoint %d mode %d", endpt, mode);
  
  	if (hpriv->endpoints[endpt] < 0) {
  		/* Pick the right endpoint node */
  		snprintf(devnode, sizeof(devnode), DEVPATH "%s.%02d",
  		    dpriv->devname, endpt);
  
  		/* We may need to read/write to the same endpoint later. */
  		if (((fd = open(devnode, O_RDWR)) < 0) && (errno == ENXIO))
  			if ((fd = open(devnode, mode)) < 0)
  				return (-1);
  
  		hpriv->endpoints[endpt] = fd;
  	}
  
  	return (hpriv->endpoints[endpt]);
  }
  
  int
  _sync_gen_transfer(struct usbi_transfer *itransfer)
  {
  	struct libusb_transfer *transfer;
  	struct device_priv *dpriv;
  	int fd, nr = 1;
  
  	transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
  	dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
  
  	if (dpriv->devname == NULL)
  		return (LIBUSB_ERROR_NOT_SUPPORTED);
  
  	/*
  	 * Bulk, Interrupt or Isochronous transfer depends on the
  	 * endpoint and thus the node to open.
  	 */
  	if ((fd = _access_endpoint(transfer)) < 0)
  		return _errno_to_libusb(errno);
  
  	if ((ioctl(fd, USB_SET_TIMEOUT, &transfer->timeout)) < 0)
  		return _errno_to_libusb(errno);
  
  	if (IS_XFERIN(transfer)) {
  		if ((transfer->flags & LIBUSB_TRANSFER_SHORT_NOT_OK) == 0)
  			if ((ioctl(fd, USB_SET_SHORT_XFER, &nr)) < 0)
  				return _errno_to_libusb(errno);
  
  		nr = read(fd, transfer->buffer, transfer->length);
  	} else {
  		nr = write(fd, transfer->buffer, transfer->length);
  	}
  
  	if (nr < 0)
  		return _errno_to_libusb(errno);
  
  	itransfer->transferred = nr;
  
  	return (0);
  }
  
  int
  _bus_open(int number)
  {
  	char busnode[16];
  
  	snprintf(busnode, sizeof(busnode), USBDEV "%d", number);
  
  	return open(busnode, O_RDWR);
  }
  