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authorZoRo <dos21h@gmail.com>2022-02-19 12:47:26 +0000
committerZoRo <dos21h@gmail.com>2022-02-19 12:47:26 +0000
commit3d7c48a6e5c5c532cdd66b3ba5a8c5911bcf2383 (patch)
treeb60e21b31eb84cbcbfa97bc10a3cdf1180ce82da /src/os/openbsd_usb.c
downloadlibrusb-3d7c48a6e5c5c532cdd66b3ba5a8c5911bcf2383.tar.gz
librusb-3d7c48a6e5c5c532cdd66b3ba5a8c5911bcf2383.zip
Initial
Diffstat (limited to 'src/os/openbsd_usb.c')
-rw-r--r--src/os/openbsd_usb.c700
1 files changed, 700 insertions, 0 deletions
diff --git a/src/os/openbsd_usb.c b/src/os/openbsd_usb.c
new file mode 100644
index 0000000..9a5c604
--- /dev/null
+++ b/src/os/openbsd_usb.c
@@ -0,0 +1,700 @@
+/*
+ * 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 <config.h>
+
+#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 "libusbi.h"
+
+struct device_priv {
+ char *devname; /* name of the ugen(4) node */
+ int fd; /* device file descriptor */
+
+ usb_config_descriptor_t *cdesc; /* active config descriptor */
+};
+
+struct handle_priv {
+ 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_active_config_descriptor(struct libusb_device *,
+ void *, size_t);
+static int obsd_get_config_descriptor(struct libusb_device *, uint8_t,
+ void *, size_t);
+
+static int obsd_get_configuration(struct libusb_device_handle *, uint8_t *);
+static int obsd_set_configuration(struct libusb_device_handle *, int);
+
+static int obsd_claim_interface(struct libusb_device_handle *, uint8_t);
+static int obsd_release_interface(struct libusb_device_handle *, uint8_t);
+
+static int obsd_set_interface_altsetting(struct libusb_device_handle *, uint8_t,
+ uint8_t);
+static int obsd_clear_halt(struct libusb_device_handle *, unsigned char);
+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 int obsd_handle_transfer_completion(struct usbi_transfer *);
+
+/*
+ * 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 usbi_backend = {
+ .name = "Synchronous OpenBSD backend",
+ .get_device_list = obsd_get_device_list,
+ .open = obsd_open,
+ .close = obsd_close,
+
+ .get_active_config_descriptor = obsd_get_active_config_descriptor,
+ .get_config_descriptor = obsd_get_config_descriptor,
+
+ .get_configuration = obsd_get_configuration,
+ .set_configuration = obsd_set_configuration,
+
+ .claim_interface = obsd_claim_interface,
+ .release_interface = obsd_release_interface,
+
+ .set_interface_altsetting = obsd_set_interface_altsetting,
+ .clear_halt = obsd_clear_halt,
+ .destroy_device = obsd_destroy_device,
+
+ .submit_transfer = obsd_submit_transfer,
+ .cancel_transfer = obsd_cancel_transfer,
+
+ .handle_transfer_completion = obsd_handle_transfer_completion,
+
+ .device_priv_size = sizeof(struct device_priv),
+ .device_handle_priv_size = sizeof(struct handle_priv),
+};
+
+#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(ctx, " ");
+
+ 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;
+ dev->port_number = di.udi_port;
+
+ dpriv = usbi_get_device_priv(dev);
+ dpriv->fd = -1;
+ 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;
+ }
+
+ static_assert(sizeof(dev->device_descriptor) == sizeof(dd.udd_desc),
+ "mismatch between libusb and OS device descriptor sizes");
+ memcpy(&dev->device_descriptor, &dd.udd_desc, LIBUSB_DT_DEVICE_SIZE);
+ usbi_localize_device_descriptor(&dev->device_descriptor);
+
+ 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 device_priv *dpriv = usbi_get_device_priv(handle->dev);
+ char devnode[16];
+
+ if (dpriv->devname) {
+ int fd;
+ /*
+ * 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);
+ fd = open(devnode, O_RDWR);
+ if (fd < 0)
+ return _errno_to_libusb(errno);
+ dpriv->fd = fd;
+
+ usbi_dbg(HANDLE_CTX(handle), "open %s: fd %d", devnode, dpriv->fd);
+ }
+
+ return (LIBUSB_SUCCESS);
+}
+
+void
+obsd_close(struct libusb_device_handle *handle)
+{
+ struct device_priv *dpriv = usbi_get_device_priv(handle->dev);
+
+ if (dpriv->devname) {
+ usbi_dbg(HANDLE_CTX(handle), "close: fd %d", dpriv->fd);
+
+ close(dpriv->fd);
+ dpriv->fd = -1;
+ }
+}
+
+int
+obsd_get_active_config_descriptor(struct libusb_device *dev,
+ void *buf, size_t len)
+{
+ struct device_priv *dpriv = usbi_get_device_priv(dev);
+
+ len = MIN(len, (size_t)UGETW(dpriv->cdesc->wTotalLength));
+
+ usbi_dbg(DEVICE_CTX(dev), "len %zu", len);
+
+ memcpy(buf, dpriv->cdesc, len);
+
+ return ((int)len);
+}
+
+int
+obsd_get_config_descriptor(struct libusb_device *dev, uint8_t idx,
+ void *buf, size_t len)
+{
+ 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(DEVICE_CTX(dev), "index %d, len %zu", 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);
+
+ return ((int)len);
+}
+
+int
+obsd_get_configuration(struct libusb_device_handle *handle, uint8_t *config)
+{
+ struct device_priv *dpriv = usbi_get_device_priv(handle->dev);
+
+ *config = dpriv->cdesc->bConfigurationValue;
+
+ usbi_dbg(HANDLE_CTX(handle), "bConfigurationValue %u", *config);
+
+ return (LIBUSB_SUCCESS);
+}
+
+int
+obsd_set_configuration(struct libusb_device_handle *handle, int config)
+{
+ struct device_priv *dpriv = usbi_get_device_priv(handle->dev);
+
+ if (dpriv->devname == NULL)
+ return (LIBUSB_ERROR_NOT_SUPPORTED);
+
+ usbi_dbg(HANDLE_CTX(handle), "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, uint8_t iface)
+{
+ struct handle_priv *hpriv = usbi_get_device_handle_priv(handle);
+ int i;
+
+ UNUSED(iface);
+
+ for (i = 0; i < USB_MAX_ENDPOINTS; i++)
+ hpriv->endpoints[i] = -1;
+
+ return (LIBUSB_SUCCESS);
+}
+
+int
+obsd_release_interface(struct libusb_device_handle *handle, uint8_t iface)
+{
+ struct handle_priv *hpriv = usbi_get_device_handle_priv(handle);
+ int i;
+
+ UNUSED(iface);
+
+ 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, uint8_t iface,
+ uint8_t altsetting)
+{
+ struct device_priv *dpriv = usbi_get_device_priv(handle->dev);
+ struct usb_alt_interface intf;
+
+ if (dpriv->devname == NULL)
+ return (LIBUSB_ERROR_NOT_SUPPORTED);
+
+ usbi_dbg(HANDLE_CTX(handle), "iface %u, setting %u", 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(HANDLE_CTX(handle), " ");
+
+ 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);
+}
+
+void
+obsd_destroy_device(struct libusb_device *dev)
+{
+ struct device_priv *dpriv = usbi_get_device_priv(dev);
+
+ usbi_dbg(DEVICE_CTX(dev), " ");
+
+ free(dpriv->cdesc);
+ free(dpriv->devname);
+}
+
+int
+obsd_submit_transfer(struct usbi_transfer *itransfer)
+{
+ struct libusb_transfer *transfer;
+ int err = 0;
+
+ usbi_dbg(ITRANSFER_CTX(itransfer), " ");
+
+ transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
+
+ 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);
+
+ usbi_signal_transfer_completion(itransfer);
+
+ return (LIBUSB_SUCCESS);
+}
+
+int
+obsd_cancel_transfer(struct usbi_transfer *itransfer)
+{
+ UNUSED(itransfer);
+
+ usbi_dbg(ITRANSFER_CTX(itransfer), " ");
+
+ return (LIBUSB_ERROR_NOT_SUPPORTED);
+}
+
+int
+obsd_handle_transfer_completion(struct usbi_transfer *itransfer)
+{
+ return usbi_handle_transfer_completion(itransfer, LIBUSB_TRANSFER_COMPLETED);
+}
+
+int
+_errno_to_libusb(int err)
+{
+ usbi_dbg(NULL, "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 = usbi_get_device_priv(dev);
+ struct usb_device_cdesc udc;
+ struct usb_device_fdesc udf;
+ void *buf;
+ int fd, len, err;
+
+ if ((fd = _bus_open(dev->bus_number)) < 0)
+ return _errno_to_libusb(errno);
+
+ usbi_dbg(DEVICE_CTX(dev), "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(DEVICE_CTX(dev), "active bLength %d", udc.udc_desc.bLength);
+
+ len = UGETW(udc.udc_desc.wTotalLength);
+ buf = malloc((size_t)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(DEVICE_CTX(dev), "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 = usbi_get_device_priv(transfer->dev_handle->dev);
+ setup = (struct libusb_control_setup *)transfer->buffer;
+
+ usbi_dbg(ITRANSFER_CTX(itransfer), "type 0x%x request 0x%x value 0x%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(ITRANSFER_CTX(itransfer), "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 = usbi_get_device_handle_priv(transfer->dev_handle);
+ dpriv = usbi_get_device_priv(transfer->dev_handle->dev);
+
+ endpt = UE_GET_ADDR(transfer->endpoint);
+ mode = IS_XFERIN(transfer) ? O_RDONLY : O_WRONLY;
+
+ usbi_dbg(TRANSFER_CTX(transfer), "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 = usbi_get_device_priv(transfer->dev_handle->dev);
+
+ 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);
+}