1/*
2 * Copyright © 2011-2013 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
35struct device_priv {
36	char *devname;				/* name of the ugen(4) node */
37	int fd;					/* device file descriptor */
38
39	unsigned char *cdesc;			/* active config descriptor */
40	usb_device_descriptor_t ddesc;		/* usb device descriptor */
41};
42
43struct handle_priv {
44	int endpoints[USB_MAX_ENDPOINTS];
45};
46
47/*
48 * Backend functions
49 */
50static int obsd_get_device_list(struct libusb_context *,
51    struct discovered_devs **);
52static int obsd_open(struct libusb_device_handle *);
53static void obsd_close(struct libusb_device_handle *);
54
55static int obsd_get_device_descriptor(struct libusb_device *, unsigned char *,
56    int *);
57static int obsd_get_active_config_descriptor(struct libusb_device *,
58    unsigned char *, size_t, int *);
59static int obsd_get_config_descriptor(struct libusb_device *, uint8_t,
60    unsigned char *, size_t, int *);
61
62static int obsd_get_configuration(struct libusb_device_handle *, int *);
63static int obsd_set_configuration(struct libusb_device_handle *, int);
64
65static int obsd_claim_interface(struct libusb_device_handle *, int);
66static int obsd_release_interface(struct libusb_device_handle *, int);
67
68static int obsd_set_interface_altsetting(struct libusb_device_handle *, int,
69    int);
70static int obsd_clear_halt(struct libusb_device_handle *, unsigned char);
71static int obsd_reset_device(struct libusb_device_handle *);
72static void obsd_destroy_device(struct libusb_device *);
73
74static int obsd_submit_transfer(struct usbi_transfer *);
75static int obsd_cancel_transfer(struct usbi_transfer *);
76static void obsd_clear_transfer_priv(struct usbi_transfer *);
77static int obsd_handle_transfer_completion(struct usbi_transfer *);
78static int obsd_clock_gettime(int, struct timespec *);
79
80/*
81 * Private functions
82 */
83static int _errno_to_libusb(int);
84static int _cache_active_config_descriptor(struct libusb_device *);
85static int _sync_control_transfer(struct usbi_transfer *);
86static int _sync_gen_transfer(struct usbi_transfer *);
87static int _access_endpoint(struct libusb_transfer *);
88
89static int _bus_open(int);
90
91
92const struct usbi_os_backend openbsd_backend = {
93	"Synchronous OpenBSD backend",
94	0,
95	NULL,				/* init() */
96	NULL,				/* exit() */
97	obsd_get_device_list,
98	NULL,				/* hotplug_poll */
99	obsd_open,
100	obsd_close,
101
102	obsd_get_device_descriptor,
103	obsd_get_active_config_descriptor,
104	obsd_get_config_descriptor,
105	NULL,				/* get_config_descriptor_by_value() */
106
107	obsd_get_configuration,
108	obsd_set_configuration,
109
110	obsd_claim_interface,
111	obsd_release_interface,
112
113	obsd_set_interface_altsetting,
114	obsd_clear_halt,
115	obsd_reset_device,
116
117	NULL,				/* alloc_streams */
118	NULL,				/* free_streams */
119
120	NULL,				/* dev_mem_alloc() */
121	NULL,				/* dev_mem_free() */
122
123	NULL,				/* kernel_driver_active() */
124	NULL,				/* detach_kernel_driver() */
125	NULL,				/* attach_kernel_driver() */
126
127	obsd_destroy_device,
128
129	obsd_submit_transfer,
130	obsd_cancel_transfer,
131	obsd_clear_transfer_priv,
132
133	NULL,				/* handle_events() */
134	obsd_handle_transfer_completion,
135
136	obsd_clock_gettime,
137	sizeof(struct device_priv),
138	sizeof(struct handle_priv),
139	0,				/* transfer_priv_size */
140};
141
142#define DEVPATH	"/dev/"
143#define USBDEV	DEVPATH "usb"
144
145int
146obsd_get_device_list(struct libusb_context * ctx,
147	struct discovered_devs **discdevs)
148{
149	struct discovered_devs *ddd;
150	struct libusb_device *dev;
151	struct device_priv *dpriv;
152	struct usb_device_info di;
153	struct usb_device_ddesc dd;
154	unsigned long session_id;
155	char devices[USB_MAX_DEVICES];
156	char busnode[16];
157	char *udevname;
158	int fd, addr, i, j;
159
160	usbi_dbg("");
161
162	for (i = 0; i < 8; i++) {
163		snprintf(busnode, sizeof(busnode), USBDEV "%d", i);
164
165		if ((fd = open(busnode, O_RDWR)) < 0) {
166			if (errno != ENOENT && errno != ENXIO)
167				usbi_err(ctx, "could not open %s", busnode);
168			continue;
169		}
170
171		bzero(devices, sizeof(devices));
172		for (addr = 1; addr < USB_MAX_DEVICES; addr++) {
173			if (devices[addr])
174				continue;
175
176			di.udi_addr = addr;
177			if (ioctl(fd, USB_DEVICEINFO, &di) < 0)
178				continue;
179
180			/*
181			 * XXX If ugen(4) is attached to the USB device
182			 * it will be used.
183			 */
184			udevname = NULL;
185			for (j = 0; j < USB_MAX_DEVNAMES; j++)
186				if (!strncmp("ugen", di.udi_devnames[j], 4)) {
187					udevname = strdup(di.udi_devnames[j]);
188					break;
189				}
190
191			session_id = (di.udi_bus << 8 | di.udi_addr);
192			dev = usbi_get_device_by_session_id(ctx, session_id);
193
194			if (dev == NULL) {
195				dev = usbi_alloc_device(ctx, session_id);
196				if (dev == NULL) {
197					close(fd);
198					return (LIBUSB_ERROR_NO_MEM);
199				}
200
201				dev->bus_number = di.udi_bus;
202				dev->device_address = di.udi_addr;
203				dev->speed = di.udi_speed;
204
205				dpriv = (struct device_priv *)dev->os_priv;
206				dpriv->fd = -1;
207				dpriv->cdesc = NULL;
208				dpriv->devname = udevname;
209
210				dd.udd_bus = di.udi_bus;
211				dd.udd_addr = di.udi_addr;
212				if (ioctl(fd, USB_DEVICE_GET_DDESC, &dd) < 0) {
213					libusb_unref_device(dev);
214					continue;
215				}
216				dpriv->ddesc = dd.udd_desc;
217
218				if (_cache_active_config_descriptor(dev)) {
219					libusb_unref_device(dev);
220					continue;
221				}
222
223				if (usbi_sanitize_device(dev)) {
224					libusb_unref_device(dev);
225					continue;
226				}
227			}
228
229			ddd = discovered_devs_append(*discdevs, dev);
230			if (ddd == NULL) {
231				close(fd);
232				return (LIBUSB_ERROR_NO_MEM);
233			}
234			libusb_unref_device(dev);
235
236			*discdevs = ddd;
237			devices[addr] = 1;
238		}
239
240		close(fd);
241	}
242
243	return (LIBUSB_SUCCESS);
244}
245
246int
247obsd_open(struct libusb_device_handle *handle)
248{
249	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
250	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
251	char devnode[16];
252
253	if (dpriv->devname) {
254		/*
255		 * Only open ugen(4) attached devices read-write, all
256		 * read-only operations are done through the bus node.
257		 */
258		snprintf(devnode, sizeof(devnode), DEVPATH "%s.00",
259		    dpriv->devname);
260		dpriv->fd = open(devnode, O_RDWR);
261		if (dpriv->fd < 0)
262			return _errno_to_libusb(errno);
263
264		usbi_dbg("open %s: fd %d", devnode, dpriv->fd);
265	}
266
267	return (LIBUSB_SUCCESS);
268}
269
270void
271obsd_close(struct libusb_device_handle *handle)
272{
273	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
274	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
275
276	if (dpriv->devname) {
277		usbi_dbg("close: fd %d", dpriv->fd);
278
279		close(dpriv->fd);
280		dpriv->fd = -1;
281	}
282}
283
284int
285obsd_get_device_descriptor(struct libusb_device *dev, unsigned char *buf,
286    int *host_endian)
287{
288	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
289
290	usbi_dbg("");
291
292	memcpy(buf, &dpriv->ddesc, DEVICE_DESC_LENGTH);
293
294	*host_endian = 0;
295
296	return (LIBUSB_SUCCESS);
297}
298
299int
300obsd_get_active_config_descriptor(struct libusb_device *dev,
301    unsigned char *buf, size_t len, int *host_endian)
302{
303	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
304	usb_config_descriptor_t *ucd = (usb_config_descriptor_t *)dpriv->cdesc;
305
306	len = MIN(len, UGETW(ucd->wTotalLength));
307
308	usbi_dbg("len %d", len);
309
310	memcpy(buf, dpriv->cdesc, len);
311
312	*host_endian = 0;
313
314	return (len);
315}
316
317int
318obsd_get_config_descriptor(struct libusb_device *dev, uint8_t idx,
319    unsigned char *buf, size_t len, int *host_endian)
320{
321	struct usb_device_fdesc udf;
322	int fd, err;
323
324	if ((fd = _bus_open(dev->bus_number)) < 0)
325		return _errno_to_libusb(errno);
326
327	udf.udf_bus = dev->bus_number;
328	udf.udf_addr = dev->device_address;
329	udf.udf_config_index = idx;
330	udf.udf_size = len;
331	udf.udf_data = buf;
332
333	usbi_dbg("index %d, len %d", udf.udf_config_index, len);
334
335	if (ioctl(fd, USB_DEVICE_GET_FDESC, &udf) < 0) {
336		err = errno;
337		close(fd);
338		return _errno_to_libusb(err);
339	}
340	close(fd);
341
342	*host_endian = 0;
343
344	return (len);
345}
346
347int
348obsd_get_configuration(struct libusb_device_handle *handle, int *config)
349{
350	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
351	usb_config_descriptor_t *ucd = (usb_config_descriptor_t *)dpriv->cdesc;
352
353	*config = ucd->bConfigurationValue;
354
355	usbi_dbg("bConfigurationValue %d", *config);
356
357	return (LIBUSB_SUCCESS);
358}
359
360int
361obsd_set_configuration(struct libusb_device_handle *handle, int config)
362{
363	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
364
365	if (dpriv->devname == NULL)
366		return (LIBUSB_ERROR_NOT_SUPPORTED);
367
368	usbi_dbg("bConfigurationValue %d", config);
369
370	if (ioctl(dpriv->fd, USB_SET_CONFIG, &config) < 0)
371		return _errno_to_libusb(errno);
372
373	return _cache_active_config_descriptor(handle->dev);
374}
375
376int
377obsd_claim_interface(struct libusb_device_handle *handle, int iface)
378{
379	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
380	int i;
381
382	for (i = 0; i < USB_MAX_ENDPOINTS; i++)
383		hpriv->endpoints[i] = -1;
384
385	return (LIBUSB_SUCCESS);
386}
387
388int
389obsd_release_interface(struct libusb_device_handle *handle, int iface)
390{
391	struct handle_priv *hpriv = (struct handle_priv *)handle->os_priv;
392	int i;
393
394	for (i = 0; i < USB_MAX_ENDPOINTS; i++)
395		if (hpriv->endpoints[i] >= 0)
396			close(hpriv->endpoints[i]);
397
398	return (LIBUSB_SUCCESS);
399}
400
401int
402obsd_set_interface_altsetting(struct libusb_device_handle *handle, int iface,
403    int altsetting)
404{
405	struct device_priv *dpriv = (struct device_priv *)handle->dev->os_priv;
406	struct usb_alt_interface intf;
407
408	if (dpriv->devname == NULL)
409		return (LIBUSB_ERROR_NOT_SUPPORTED);
410
411	usbi_dbg("iface %d, setting %d", iface, altsetting);
412
413	memset(&intf, 0, sizeof(intf));
414
415	intf.uai_interface_index = iface;
416	intf.uai_alt_no = altsetting;
417
418	if (ioctl(dpriv->fd, USB_SET_ALTINTERFACE, &intf) < 0)
419		return _errno_to_libusb(errno);
420
421	return (LIBUSB_SUCCESS);
422}
423
424int
425obsd_clear_halt(struct libusb_device_handle *handle, unsigned char endpoint)
426{
427	struct usb_ctl_request req;
428	int fd, err;
429
430	if ((fd = _bus_open(handle->dev->bus_number)) < 0)
431		return _errno_to_libusb(errno);
432
433	usbi_dbg("");
434
435	req.ucr_addr = handle->dev->device_address;
436	req.ucr_request.bmRequestType = UT_WRITE_ENDPOINT;
437	req.ucr_request.bRequest = UR_CLEAR_FEATURE;
438	USETW(req.ucr_request.wValue, UF_ENDPOINT_HALT);
439	USETW(req.ucr_request.wIndex, endpoint);
440	USETW(req.ucr_request.wLength, 0);
441
442	if (ioctl(fd, USB_REQUEST, &req) < 0) {
443		err = errno;
444		close(fd);
445		return _errno_to_libusb(err);
446	}
447	close(fd);
448
449	return (LIBUSB_SUCCESS);
450}
451
452int
453obsd_reset_device(struct libusb_device_handle *handle)
454{
455	usbi_dbg("");
456
457	return (LIBUSB_ERROR_NOT_SUPPORTED);
458}
459
460void
461obsd_destroy_device(struct libusb_device *dev)
462{
463	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
464
465	usbi_dbg("");
466
467	free(dpriv->cdesc);
468	free(dpriv->devname);
469}
470
471int
472obsd_submit_transfer(struct usbi_transfer *itransfer)
473{
474	struct libusb_transfer *transfer;
475	struct handle_priv *hpriv;
476	int err = 0;
477
478	usbi_dbg("");
479
480	transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
481	hpriv = (struct handle_priv *)transfer->dev_handle->os_priv;
482
483	switch (transfer->type) {
484	case LIBUSB_TRANSFER_TYPE_CONTROL:
485		err = _sync_control_transfer(itransfer);
486		break;
487	case LIBUSB_TRANSFER_TYPE_ISOCHRONOUS:
488		if (IS_XFEROUT(transfer)) {
489			/* Isochronous write is not supported */
490			err = LIBUSB_ERROR_NOT_SUPPORTED;
491			break;
492		}
493		err = _sync_gen_transfer(itransfer);
494		break;
495	case LIBUSB_TRANSFER_TYPE_BULK:
496	case LIBUSB_TRANSFER_TYPE_INTERRUPT:
497		if (IS_XFEROUT(transfer) &&
498		    transfer->flags & LIBUSB_TRANSFER_ADD_ZERO_PACKET) {
499			err = LIBUSB_ERROR_NOT_SUPPORTED;
500			break;
501		}
502		err = _sync_gen_transfer(itransfer);
503		break;
504	case LIBUSB_TRANSFER_TYPE_BULK_STREAM:
505		err = LIBUSB_ERROR_NOT_SUPPORTED;
506		break;
507	}
508
509	if (err)
510		return (err);
511
512	usbi_signal_transfer_completion(itransfer);
513
514	return (LIBUSB_SUCCESS);
515}
516
517int
518obsd_cancel_transfer(struct usbi_transfer *itransfer)
519{
520	usbi_dbg("");
521
522	return (LIBUSB_ERROR_NOT_SUPPORTED);
523}
524
525void
526obsd_clear_transfer_priv(struct usbi_transfer *itransfer)
527{
528	usbi_dbg("");
529
530	/* Nothing to do */
531}
532
533int
534obsd_handle_transfer_completion(struct usbi_transfer *itransfer)
535{
536	return usbi_handle_transfer_completion(itransfer, LIBUSB_TRANSFER_COMPLETED);
537}
538
539int
540obsd_clock_gettime(int clkid, struct timespec *tp)
541{
542	usbi_dbg("clock %d", clkid);
543
544	if (clkid == USBI_CLOCK_REALTIME)
545		return clock_gettime(CLOCK_REALTIME, tp);
546
547	if (clkid == USBI_CLOCK_MONOTONIC)
548		return clock_gettime(CLOCK_MONOTONIC, tp);
549
550	return (LIBUSB_ERROR_INVALID_PARAM);
551}
552
553int
554_errno_to_libusb(int err)
555{
556	usbi_dbg("error: %s (%d)", strerror(err), err);
557
558	switch (err) {
559	case EIO:
560		return (LIBUSB_ERROR_IO);
561	case EACCES:
562		return (LIBUSB_ERROR_ACCESS);
563	case ENOENT:
564		return (LIBUSB_ERROR_NO_DEVICE);
565	case ENOMEM:
566		return (LIBUSB_ERROR_NO_MEM);
567	case ETIMEDOUT:
568		return (LIBUSB_ERROR_TIMEOUT);
569	}
570
571	return (LIBUSB_ERROR_OTHER);
572}
573
574int
575_cache_active_config_descriptor(struct libusb_device *dev)
576{
577	struct device_priv *dpriv = (struct device_priv *)dev->os_priv;
578	struct usb_device_cdesc udc;
579	struct usb_device_fdesc udf;
580	unsigned char* buf;
581	int fd, len, err;
582
583	if ((fd = _bus_open(dev->bus_number)) < 0)
584		return _errno_to_libusb(errno);
585
586	usbi_dbg("fd %d, addr %d", fd, dev->device_address);
587
588	udc.udc_bus = dev->bus_number;
589	udc.udc_addr = dev->device_address;
590	udc.udc_config_index = USB_CURRENT_CONFIG_INDEX;
591	if (ioctl(fd, USB_DEVICE_GET_CDESC, &udc) < 0) {
592		err = errno;
593		close(fd);
594		return _errno_to_libusb(errno);
595	}
596
597	usbi_dbg("active bLength %d", udc.udc_desc.bLength);
598
599	len = UGETW(udc.udc_desc.wTotalLength);
600	buf = malloc(len);
601	if (buf == NULL)
602		return (LIBUSB_ERROR_NO_MEM);
603
604	udf.udf_bus = dev->bus_number;
605	udf.udf_addr = dev->device_address;
606	udf.udf_config_index = udc.udc_config_index;
607	udf.udf_size = len;
608	udf.udf_data = buf;
609
610	usbi_dbg("index %d, len %d", udf.udf_config_index, len);
611
612	if (ioctl(fd, USB_DEVICE_GET_FDESC, &udf) < 0) {
613		err = errno;
614		close(fd);
615		free(buf);
616		return _errno_to_libusb(err);
617	}
618	close(fd);
619
620	if (dpriv->cdesc)
621		free(dpriv->cdesc);
622	dpriv->cdesc = buf;
623
624	return (LIBUSB_SUCCESS);
625}
626
627int
628_sync_control_transfer(struct usbi_transfer *itransfer)
629{
630	struct libusb_transfer *transfer;
631	struct libusb_control_setup *setup;
632	struct device_priv *dpriv;
633	struct usb_ctl_request req;
634
635	transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
636	dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
637	setup = (struct libusb_control_setup *)transfer->buffer;
638
639	usbi_dbg("type %x request %x value %x index %d length %d timeout %d",
640	    setup->bmRequestType, setup->bRequest,
641	    libusb_le16_to_cpu(setup->wValue),
642	    libusb_le16_to_cpu(setup->wIndex),
643	    libusb_le16_to_cpu(setup->wLength), transfer->timeout);
644
645	req.ucr_addr = transfer->dev_handle->dev->device_address;
646	req.ucr_request.bmRequestType = setup->bmRequestType;
647	req.ucr_request.bRequest = setup->bRequest;
648	/* Don't use USETW, libusb already deals with the endianness */
649	(*(uint16_t *)req.ucr_request.wValue) = setup->wValue;
650	(*(uint16_t *)req.ucr_request.wIndex) = setup->wIndex;
651	(*(uint16_t *)req.ucr_request.wLength) = setup->wLength;
652	req.ucr_data = transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE;
653
654	if ((transfer->flags & LIBUSB_TRANSFER_SHORT_NOT_OK) == 0)
655		req.ucr_flags = USBD_SHORT_XFER_OK;
656
657	if (dpriv->devname == NULL) {
658		/*
659		 * XXX If the device is not attached to ugen(4) it is
660		 * XXX still possible to submit a control transfer but
661		 * XXX with the default timeout only.
662		 */
663		int fd, err;
664
665		if ((fd = _bus_open(transfer->dev_handle->dev->bus_number)) < 0)
666			return _errno_to_libusb(errno);
667
668		if ((ioctl(fd, USB_REQUEST, &req)) < 0) {
669			err = errno;
670			close(fd);
671			return _errno_to_libusb(err);
672		}
673		close(fd);
674	} else {
675		if ((ioctl(dpriv->fd, USB_SET_TIMEOUT, &transfer->timeout)) < 0)
676			return _errno_to_libusb(errno);
677
678		if ((ioctl(dpriv->fd, USB_DO_REQUEST, &req)) < 0)
679			return _errno_to_libusb(errno);
680	}
681
682	itransfer->transferred = req.ucr_actlen;
683
684	usbi_dbg("transferred %d", itransfer->transferred);
685
686	return (0);
687}
688
689int
690_access_endpoint(struct libusb_transfer *transfer)
691{
692	struct handle_priv *hpriv;
693	struct device_priv *dpriv;
694	char devnode[16];
695	int fd, endpt;
696	mode_t mode;
697
698	hpriv = (struct handle_priv *)transfer->dev_handle->os_priv;
699	dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
700
701	endpt = UE_GET_ADDR(transfer->endpoint);
702	mode = IS_XFERIN(transfer) ? O_RDONLY : O_WRONLY;
703
704	usbi_dbg("endpoint %d mode %d", endpt, mode);
705
706	if (hpriv->endpoints[endpt] < 0) {
707		/* Pick the right endpoint node */
708		snprintf(devnode, sizeof(devnode), DEVPATH "%s.%02d",
709		    dpriv->devname, endpt);
710
711		/* We may need to read/write to the same endpoint later. */
712		if (((fd = open(devnode, O_RDWR)) < 0) && (errno == ENXIO))
713			if ((fd = open(devnode, mode)) < 0)
714				return (-1);
715
716		hpriv->endpoints[endpt] = fd;
717	}
718
719	return (hpriv->endpoints[endpt]);
720}
721
722int
723_sync_gen_transfer(struct usbi_transfer *itransfer)
724{
725	struct libusb_transfer *transfer;
726	struct device_priv *dpriv;
727	int fd, nr = 1;
728
729	transfer = USBI_TRANSFER_TO_LIBUSB_TRANSFER(itransfer);
730	dpriv = (struct device_priv *)transfer->dev_handle->dev->os_priv;
731
732	if (dpriv->devname == NULL)
733		return (LIBUSB_ERROR_NOT_SUPPORTED);
734
735	/*
736	 * Bulk, Interrupt or Isochronous transfer depends on the
737	 * endpoint and thus the node to open.
738	 */
739	if ((fd = _access_endpoint(transfer)) < 0)
740		return _errno_to_libusb(errno);
741
742	if ((ioctl(fd, USB_SET_TIMEOUT, &transfer->timeout)) < 0)
743		return _errno_to_libusb(errno);
744
745	if (IS_XFERIN(transfer)) {
746		if ((transfer->flags & LIBUSB_TRANSFER_SHORT_NOT_OK) == 0)
747			if ((ioctl(fd, USB_SET_SHORT_XFER, &nr)) < 0)
748				return _errno_to_libusb(errno);
749
750		nr = read(fd, transfer->buffer, transfer->length);
751	} else {
752		nr = write(fd, transfer->buffer, transfer->length);
753	}
754
755	if (nr < 0)
756		return _errno_to_libusb(errno);
757
758	itransfer->transferred = nr;
759
760	return (0);
761}
762
763int
764_bus_open(int number)
765{
766	char busnode[16];
767
768	snprintf(busnode, sizeof(busnode), USBDEV "%d", number);
769
770	return open(busnode, O_RDWR);
771}
772