xref: /freebsd/lib/libusb/libusb01.c (revision 62cfcf62f627e5093fb37026a6d8c98e4d2ef04c)
1 /* $FreeBSD$ */
2 /*-
3  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4  *
5  * Copyright (c) 2008 Hans Petter Selasky. All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * This file contains the emulation layer for LibUSB v0.1 from sourceforge.
31  */
32 
33 #ifdef LIBUSB_GLOBAL_INCLUDE_FILE
34 #include LIBUSB_GLOBAL_INCLUDE_FILE
35 #else
36 #include <errno.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <time.h>
41 #include <sys/queue.h>
42 #endif
43 
44 #include "libusb20.h"
45 #include "libusb20_desc.h"
46 #include "libusb20_int.h"
47 #include "usb.h"
48 
49 /*
50  * The two following macros were taken from the original LibUSB v0.1
51  * for sake of compatibility:
52  */
53 #define	LIST_ADD(begin, ent)	   \
54   do {				   \
55     if (begin) {		   \
56       ent->next = begin;	   \
57       ent->next->prev = ent;	   \
58     } else {			   \
59       ent->next = NULL;		   \
60     }				   \
61     ent->prev = NULL;		   \
62     begin = ent;		   \
63   } while(0)
64 
65 #define	LIST_DEL(begin, ent)		 \
66   do {					 \
67     if (ent->prev) {			 \
68       ent->prev->next = ent->next;	 \
69     } else {				 \
70       begin = ent->next;		 \
71     }					 \
72     if (ent->next) {			 \
73       ent->next->prev = ent->prev;	 \
74     }					 \
75     ent->prev = NULL;			 \
76     ent->next = NULL;			 \
77   } while (0)
78 
79 struct usb_bus *usb_busses = NULL;
80 
81 static struct usb_bus usb_global_bus = {
82 	.dirname = {"/dev/usb"},
83 	.root_dev = NULL,
84 	.devices = NULL,
85 };
86 
87 static struct libusb20_backend *usb_backend = NULL;
88 
89 struct usb_parse_state {
90 
91 	struct {
92 		struct libusb20_endpoint *currep;
93 		struct libusb20_interface *currifc;
94 		struct libusb20_config *currcfg;
95 		struct libusb20_me_struct *currextra;
96 	}	a;
97 
98 	struct {
99 		struct usb_config_descriptor *currcfg;
100 		struct usb_interface_descriptor *currifc;
101 		struct usb_endpoint_descriptor *currep;
102 		struct usb_interface *currifcw;
103 		uint8_t *currextra;
104 	}	b;
105 
106 	uint8_t	preparse;
107 };
108 
109 static struct libusb20_transfer *
110 usb_get_transfer_by_ep_no(usb_dev_handle * dev, uint8_t ep_no)
111 {
112 	struct libusb20_device *pdev = (void *)dev;
113 	struct libusb20_transfer *xfer;
114 	int err;
115 	uint32_t bufsize;
116 	uint8_t x;
117 	uint8_t speed;
118 
119 	x = (ep_no & LIBUSB20_ENDPOINT_ADDRESS_MASK) * 2;
120 
121 	if (ep_no & LIBUSB20_ENDPOINT_DIR_MASK) {
122 		/* this is an IN endpoint */
123 		x |= 1;
124 	}
125 	speed = libusb20_dev_get_speed(pdev);
126 
127 	/* select a sensible buffer size */
128 	if (speed == LIBUSB20_SPEED_LOW) {
129 		bufsize = 256;
130 	} else if (speed == LIBUSB20_SPEED_FULL) {
131 		bufsize = 4096;
132 	} else if (speed == LIBUSB20_SPEED_SUPER) {
133 		bufsize = 65536;
134 	} else {
135 		bufsize = 16384;
136 	}
137 
138 	xfer = libusb20_tr_get_pointer(pdev, x);
139 
140 	if (xfer == NULL)
141 		return (xfer);
142 
143 	err = libusb20_tr_open(xfer, bufsize, 1, ep_no);
144 	if (err == LIBUSB20_ERROR_BUSY) {
145 		/* already opened */
146 		return (xfer);
147 	} else if (err) {
148 		return (NULL);
149 	}
150 	/* success */
151 	return (xfer);
152 }
153 
154 usb_dev_handle *
155 usb_open(struct usb_device *dev)
156 {
157 	int err;
158 
159 	err = libusb20_dev_open(dev->dev, 16 * 2);
160 	if (err == LIBUSB20_ERROR_BUSY) {
161 		/*
162 		 * Workaround buggy USB applications which open the USB
163 		 * device multiple times:
164 		 */
165 		return (dev->dev);
166 	}
167 	if (err)
168 		return (NULL);
169 
170 	/*
171 	 * Dequeue USB device from backend queue so that it does not get
172 	 * freed when the backend is re-scanned:
173 	 */
174 	libusb20_be_dequeue_device(usb_backend, dev->dev);
175 
176 	return (dev->dev);
177 }
178 
179 int
180 usb_close(usb_dev_handle * udev)
181 {
182 	struct usb_device *dev;
183 	int err;
184 
185 	err = libusb20_dev_close((void *)udev);
186 
187 	if (err)
188 		return (-1);
189 
190 	if (usb_backend != NULL) {
191 		/*
192 		 * Enqueue USB device to backend queue so that it gets freed
193 		 * when the backend is re-scanned:
194 		 */
195 		libusb20_be_enqueue_device(usb_backend, (void *)udev);
196 	} else {
197 		/*
198 		 * The backend is gone. Free device data so that we
199 		 * don't start leaking memory!
200 		 */
201 		dev = usb_device(udev);
202 		libusb20_dev_free((void *)udev);
203 		LIST_DEL(usb_global_bus.devices, dev);
204 		free(dev);
205 	}
206 	return (0);
207 }
208 
209 int
210 usb_get_string(usb_dev_handle * dev, int strindex,
211     int langid, char *buf, size_t buflen)
212 {
213 	int err;
214 
215 	if (dev == NULL)
216 		return (-1);
217 
218 	if (buflen > 65535)
219 		buflen = 65535;
220 
221 	err = libusb20_dev_req_string_sync((void *)dev,
222 	    strindex, langid, buf, buflen);
223 
224 	if (err)
225 		return (-1);
226 
227 	return (0);
228 }
229 
230 int
231 usb_get_string_simple(usb_dev_handle * dev, int strindex,
232     char *buf, size_t buflen)
233 {
234 	int err;
235 
236 	if (dev == NULL)
237 		return (-1);
238 
239 	if (buflen > 65535)
240 		buflen = 65535;
241 
242 	err = libusb20_dev_req_string_simple_sync((void *)dev,
243 	    strindex, buf, buflen);
244 
245 	if (err)
246 		return (-1);
247 
248 	return (strlen(buf));
249 }
250 
251 int
252 usb_get_descriptor_by_endpoint(usb_dev_handle * udev, int ep, uint8_t type,
253     uint8_t ep_index, void *buf, int size)
254 {
255 	memset(buf, 0, size);
256 
257 	if (udev == NULL)
258 		return (-1);
259 
260 	if (size > 65535)
261 		size = 65535;
262 
263 	return (usb_control_msg(udev, ep | USB_ENDPOINT_IN,
264 	    USB_REQ_GET_DESCRIPTOR, (type << 8) + ep_index, 0,
265 	    buf, size, 1000));
266 }
267 
268 int
269 usb_get_descriptor(usb_dev_handle * udev, uint8_t type, uint8_t desc_index,
270     void *buf, int size)
271 {
272 	memset(buf, 0, size);
273 
274 	if (udev == NULL)
275 		return (-1);
276 
277 	if (size > 65535)
278 		size = 65535;
279 
280 	return (usb_control_msg(udev, USB_ENDPOINT_IN, USB_REQ_GET_DESCRIPTOR,
281 	    (type << 8) + desc_index, 0, buf, size, 1000));
282 }
283 
284 int
285 usb_parse_descriptor(uint8_t *source, char *description, void *dest)
286 {
287 	uint8_t *sp = source;
288 	uint8_t *dp = dest;
289 	uint16_t w;
290 	uint32_t d;
291 	char *cp;
292 
293 	for (cp = description; *cp; cp++) {
294 		switch (*cp) {
295 		case 'b':		/* 8-bit byte */
296 			*dp++ = *sp++;
297 			break;
298 			/*
299 			 * 16-bit word, convert from little endian to CPU
300 			 */
301 		case 'w':
302 			w = (sp[1] << 8) | sp[0];
303 			sp += 2;
304 			/* Align to word boundary */
305 			dp += ((dp - (uint8_t *)0) & 1);
306 			*((uint16_t *)dp) = w;
307 			dp += 2;
308 			break;
309 			/*
310 			 * 32-bit dword, convert from little endian to CPU
311 			 */
312 		case 'd':
313 			d = (sp[3] << 24) | (sp[2] << 16) |
314 			    (sp[1] << 8) | sp[0];
315 			sp += 4;
316 			/* Align to word boundary */
317 			dp += ((dp - (uint8_t *)0) & 1);
318 			/* Align to double word boundary */
319 			dp += ((dp - (uint8_t *)0) & 2);
320 			*((uint32_t *)dp) = d;
321 			dp += 4;
322 			break;
323 		}
324 	}
325 	return (sp - source);
326 }
327 
328 static void
329 usb_parse_extra(struct usb_parse_state *ps, uint8_t **pptr, int *plen)
330 {
331 	void *ptr;
332 	uint16_t len;
333 
334 	ptr = ps->a.currextra->ptr;
335 	len = ps->a.currextra->len;
336 
337 	if (ps->preparse == 0) {
338 		memcpy(ps->b.currextra, ptr, len);
339 		*pptr = ps->b.currextra;
340 		*plen = len;
341 	}
342 	ps->b.currextra += len;
343 	return;
344 }
345 
346 static void
347 usb_parse_endpoint(struct usb_parse_state *ps)
348 {
349 	struct usb_endpoint_descriptor *bep;
350 	struct libusb20_endpoint *aep;
351 
352 	aep = ps->a.currep;
353 	bep = ps->b.currep++;
354 
355 	if (ps->preparse == 0) {
356 		/* copy descriptor fields */
357 		bep->bLength = aep->desc.bLength;
358 		bep->bDescriptorType = aep->desc.bDescriptorType;
359 		bep->bEndpointAddress = aep->desc.bEndpointAddress;
360 		bep->bmAttributes = aep->desc.bmAttributes;
361 		bep->wMaxPacketSize = aep->desc.wMaxPacketSize;
362 		bep->bInterval = aep->desc.bInterval;
363 		bep->bRefresh = aep->desc.bRefresh;
364 		bep->bSynchAddress = aep->desc.bSynchAddress;
365 	}
366 	ps->a.currextra = &aep->extra;
367 	usb_parse_extra(ps, &bep->extra, &bep->extralen);
368 	return;
369 }
370 
371 static void
372 usb_parse_iface_sub(struct usb_parse_state *ps)
373 {
374 	struct libusb20_interface *aifc;
375 	struct usb_interface_descriptor *bifc;
376 	uint8_t x;
377 
378 	aifc = ps->a.currifc;
379 	bifc = ps->b.currifc++;
380 
381 	if (ps->preparse == 0) {
382 		/* copy descriptor fields */
383 		bifc->bLength = aifc->desc.bLength;
384 		bifc->bDescriptorType = aifc->desc.bDescriptorType;
385 		bifc->bInterfaceNumber = aifc->desc.bInterfaceNumber;
386 		bifc->bAlternateSetting = aifc->desc.bAlternateSetting;
387 		bifc->bNumEndpoints = aifc->num_endpoints;
388 		bifc->bInterfaceClass = aifc->desc.bInterfaceClass;
389 		bifc->bInterfaceSubClass = aifc->desc.bInterfaceSubClass;
390 		bifc->bInterfaceProtocol = aifc->desc.bInterfaceProtocol;
391 		bifc->iInterface = aifc->desc.iInterface;
392 		bifc->endpoint = ps->b.currep;
393 	}
394 	for (x = 0; x != aifc->num_endpoints; x++) {
395 		ps->a.currep = aifc->endpoints + x;
396 		usb_parse_endpoint(ps);
397 	}
398 
399 	ps->a.currextra = &aifc->extra;
400 	usb_parse_extra(ps, &bifc->extra, &bifc->extralen);
401 	return;
402 }
403 
404 static void
405 usb_parse_iface(struct usb_parse_state *ps)
406 {
407 	struct libusb20_interface *aifc;
408 	struct usb_interface *bifc;
409 	uint8_t x;
410 
411 	aifc = ps->a.currifc;
412 	bifc = ps->b.currifcw++;
413 
414 	if (ps->preparse == 0) {
415 		/* initialise interface wrapper */
416 		bifc->altsetting = ps->b.currifc;
417 		bifc->num_altsetting = aifc->num_altsetting + 1;
418 	}
419 	usb_parse_iface_sub(ps);
420 
421 	for (x = 0; x != aifc->num_altsetting; x++) {
422 		ps->a.currifc = aifc->altsetting + x;
423 		usb_parse_iface_sub(ps);
424 	}
425 	return;
426 }
427 
428 static void
429 usb_parse_config(struct usb_parse_state *ps)
430 {
431 	struct libusb20_config *acfg;
432 	struct usb_config_descriptor *bcfg;
433 	uint8_t x;
434 
435 	acfg = ps->a.currcfg;
436 	bcfg = ps->b.currcfg;
437 
438 	if (ps->preparse == 0) {
439 		/* initialise config wrapper */
440 		bcfg->bLength = acfg->desc.bLength;
441 		bcfg->bDescriptorType = acfg->desc.bDescriptorType;
442 		bcfg->wTotalLength = acfg->desc.wTotalLength;
443 		bcfg->bNumInterfaces = acfg->num_interface;
444 		bcfg->bConfigurationValue = acfg->desc.bConfigurationValue;
445 		bcfg->iConfiguration = acfg->desc.iConfiguration;
446 		bcfg->bmAttributes = acfg->desc.bmAttributes;
447 		bcfg->MaxPower = acfg->desc.bMaxPower;
448 		bcfg->interface = ps->b.currifcw;
449 	}
450 	for (x = 0; x != acfg->num_interface; x++) {
451 		ps->a.currifc = acfg->interface + x;
452 		usb_parse_iface(ps);
453 	}
454 
455 	ps->a.currextra = &acfg->extra;
456 	usb_parse_extra(ps, &bcfg->extra, &bcfg->extralen);
457 	return;
458 }
459 
460 int
461 usb_parse_configuration(struct usb_config_descriptor *config,
462     uint8_t *buffer)
463 {
464 	struct usb_parse_state ps;
465 	uint8_t *ptr;
466 	uint32_t a;
467 	uint32_t b;
468 	uint32_t c;
469 	uint32_t d;
470 
471 	if ((buffer == NULL) || (config == NULL)) {
472 		return (-1);
473 	}
474 	memset(&ps, 0, sizeof(ps));
475 
476 	ps.a.currcfg = libusb20_parse_config_desc(buffer);
477 	ps.b.currcfg = config;
478 	if (ps.a.currcfg == NULL) {
479 		/* could not parse config or out of memory */
480 		return (-1);
481 	}
482 	/* do the pre-parse */
483 	ps.preparse = 1;
484 	usb_parse_config(&ps);
485 
486 	a = ((uint8_t *)(ps.b.currifcw) - ((uint8_t *)0));
487 	b = ((uint8_t *)(ps.b.currifc) - ((uint8_t *)0));
488 	c = ((uint8_t *)(ps.b.currep) - ((uint8_t *)0));
489 	d = ((uint8_t *)(ps.b.currextra) - ((uint8_t *)0));
490 
491 	/* allocate memory for our configuration */
492 	ptr = malloc(a + b + c + d);
493 	if (ptr == NULL) {
494 		/* free config structure */
495 		free(ps.a.currcfg);
496 		return (-1);
497 	}
498 
499 	/* "currifcw" must be first, hence this pointer is freed */
500 	ps.b.currifcw = (void *)(ptr);
501 	ps.b.currifc = (void *)(ptr + a);
502 	ps.b.currep = (void *)(ptr + a + b);
503 	ps.b.currextra = (void *)(ptr + a + b + c);
504 
505 	/* generate a libusb v0.1 compatible structure */
506 	ps.preparse = 0;
507 	usb_parse_config(&ps);
508 
509 	/* free config structure */
510 	free(ps.a.currcfg);
511 
512 	return (0);			/* success */
513 }
514 
515 void
516 usb_destroy_configuration(struct usb_device *dev)
517 {
518 	uint8_t c;
519 
520 	if (dev->config == NULL) {
521 		return;
522 	}
523 	for (c = 0; c != dev->descriptor.bNumConfigurations; c++) {
524 		struct usb_config_descriptor *cf = &dev->config[c];
525 
526 		if (cf->interface != NULL) {
527 			free(cf->interface);
528 			cf->interface = NULL;
529 		}
530 	}
531 
532 	free(dev->config);
533 	dev->config = NULL;
534 	return;
535 }
536 
537 void
538 usb_fetch_and_parse_descriptors(usb_dev_handle * udev)
539 {
540 	struct usb_device *dev;
541 	struct libusb20_device *pdev;
542 	uint8_t *ptr;
543 	int error;
544 	uint32_t size;
545 	uint16_t len;
546 	uint8_t x;
547 
548 	if (udev == NULL) {
549 		/* be NULL safe */
550 		return;
551 	}
552 	dev = usb_device(udev);
553 	pdev = (void *)udev;
554 
555 	if (dev->descriptor.bNumConfigurations == 0) {
556 		/* invalid device */
557 		return;
558 	}
559 	size = dev->descriptor.bNumConfigurations *
560 	    sizeof(struct usb_config_descriptor);
561 
562 	dev->config = malloc(size);
563 	if (dev->config == NULL) {
564 		/* out of memory */
565 		return;
566 	}
567 	memset(dev->config, 0, size);
568 
569 	for (x = 0; x != dev->descriptor.bNumConfigurations; x++) {
570 
571 		error = (pdev->methods->get_config_desc_full) (
572 		    pdev, &ptr, &len, x);
573 
574 		if (error) {
575 			usb_destroy_configuration(dev);
576 			return;
577 		}
578 		usb_parse_configuration(dev->config + x, ptr);
579 
580 		/* free config buffer */
581 		free(ptr);
582 	}
583 	return;
584 }
585 
586 static int
587 usb_std_io(usb_dev_handle * dev, int ep, char *bytes, int size,
588     int timeout, int is_intr)
589 {
590 	struct libusb20_transfer *xfer;
591 	uint32_t temp;
592 	uint32_t maxsize;
593 	uint32_t actlen;
594 	char *oldbytes;
595 
596 	xfer = usb_get_transfer_by_ep_no(dev, ep);
597 	if (xfer == NULL)
598 		return (-1);
599 
600 	if (libusb20_tr_pending(xfer)) {
601 		/* there is already a transfer ongoing */
602 		return (-1);
603 	}
604 	maxsize = libusb20_tr_get_max_total_length(xfer);
605 	oldbytes = bytes;
606 
607 	/*
608 	 * We allow transferring zero bytes which is the same
609 	 * equivalent to a zero length USB packet.
610 	 */
611 	do {
612 
613 		temp = size;
614 		if (temp > maxsize) {
615 			/* find maximum possible length */
616 			temp = maxsize;
617 		}
618 		if (is_intr)
619 			libusb20_tr_setup_intr(xfer, bytes, temp, timeout);
620 		else
621 			libusb20_tr_setup_bulk(xfer, bytes, temp, timeout);
622 
623 		libusb20_tr_start(xfer);
624 
625 		while (1) {
626 
627 			if (libusb20_dev_process((void *)dev) != 0) {
628 				/* device detached */
629 				return (-1);
630 			}
631 			if (libusb20_tr_pending(xfer) == 0) {
632 				/* transfer complete */
633 				break;
634 			}
635 			/* wait for USB event from kernel */
636 			libusb20_dev_wait_process((void *)dev, -1);
637 		}
638 
639 		switch (libusb20_tr_get_status(xfer)) {
640 		case 0:
641 			/* success */
642 			break;
643 		case LIBUSB20_TRANSFER_TIMED_OUT:
644 			/* transfer timeout */
645 			return (-ETIMEDOUT);
646 		default:
647 			/* other transfer error */
648 			return (-ENXIO);
649 		}
650 		actlen = libusb20_tr_get_actual_length(xfer);
651 
652 		bytes += actlen;
653 		size -= actlen;
654 
655 		if (actlen != temp) {
656 			/* short transfer */
657 			break;
658 		}
659 	} while (size > 0);
660 
661 	return (bytes - oldbytes);
662 }
663 
664 int
665 usb_bulk_write(usb_dev_handle * dev, int ep, char *bytes,
666     int size, int timeout)
667 {
668 	return (usb_std_io(dev, ep & ~USB_ENDPOINT_DIR_MASK,
669 	    bytes, size, timeout, 0));
670 }
671 
672 int
673 usb_bulk_read(usb_dev_handle * dev, int ep, char *bytes,
674     int size, int timeout)
675 {
676 	return (usb_std_io(dev, ep | USB_ENDPOINT_DIR_MASK,
677 	    bytes, size, timeout, 0));
678 }
679 
680 int
681 usb_interrupt_write(usb_dev_handle * dev, int ep, char *bytes,
682     int size, int timeout)
683 {
684 	return (usb_std_io(dev, ep & ~USB_ENDPOINT_DIR_MASK,
685 	    bytes, size, timeout, 1));
686 }
687 
688 int
689 usb_interrupt_read(usb_dev_handle * dev, int ep, char *bytes,
690     int size, int timeout)
691 {
692 	return (usb_std_io(dev, ep | USB_ENDPOINT_DIR_MASK,
693 	    bytes, size, timeout, 1));
694 }
695 
696 int
697 usb_control_msg(usb_dev_handle * dev, int requesttype, int request,
698     int value, int wIndex, char *bytes, int size, int timeout)
699 {
700 	struct LIBUSB20_CONTROL_SETUP_DECODED req;
701 	int err;
702 	uint16_t actlen;
703 
704 	LIBUSB20_INIT(LIBUSB20_CONTROL_SETUP, &req);
705 
706 	req.bmRequestType = requesttype;
707 	req.bRequest = request;
708 	req.wValue = value;
709 	req.wIndex = wIndex;
710 	req.wLength = size;
711 
712 	err = libusb20_dev_request_sync((void *)dev, &req, bytes,
713 	    &actlen, timeout, 0);
714 
715 	if (err)
716 		return (-1);
717 
718 	return (actlen);
719 }
720 
721 int
722 usb_set_configuration(usb_dev_handle * udev, int bConfigurationValue)
723 {
724 	struct usb_device *dev;
725 	int err;
726 	uint8_t i;
727 
728 	/*
729 	 * Need to translate from "bConfigurationValue" to
730 	 * configuration index:
731 	 */
732 
733 	if (bConfigurationValue == 0) {
734 		/* unconfigure */
735 		i = 255;
736 	} else {
737 		/* lookup configuration index */
738 		dev = usb_device(udev);
739 
740 		/* check if the configuration array is not there */
741 		if (dev->config == NULL) {
742 			return (-1);
743 		}
744 		for (i = 0;; i++) {
745 			if (i == dev->descriptor.bNumConfigurations) {
746 				/* "bConfigurationValue" not found */
747 				return (-1);
748 			}
749 			if ((dev->config + i)->bConfigurationValue ==
750 			    bConfigurationValue) {
751 				break;
752 			}
753 		}
754 	}
755 
756 	err = libusb20_dev_set_config_index((void *)udev, i);
757 
758 	if (err)
759 		return (-1);
760 
761 	return (0);
762 }
763 
764 int
765 usb_claim_interface(usb_dev_handle * dev, int interface)
766 {
767 	struct libusb20_device *pdev = (void *)dev;
768 
769 	pdev->claimed_interface = interface;
770 
771 	return (0);
772 }
773 
774 int
775 usb_release_interface(usb_dev_handle * dev, int interface)
776 {
777 	/* do nothing */
778 	return (0);
779 }
780 
781 int
782 usb_set_altinterface(usb_dev_handle * dev, int alternate)
783 {
784 	struct libusb20_device *pdev = (void *)dev;
785 	int err;
786 	uint8_t iface;
787 
788 	iface = pdev->claimed_interface;
789 
790 	err = libusb20_dev_set_alt_index((void *)dev, iface, alternate);
791 
792 	if (err)
793 		return (-1);
794 
795 	return (0);
796 }
797 
798 int
799 usb_resetep(usb_dev_handle * dev, unsigned int ep)
800 {
801 	/* emulate an endpoint reset through clear-STALL */
802 	return (usb_clear_halt(dev, ep));
803 }
804 
805 int
806 usb_clear_halt(usb_dev_handle * dev, unsigned int ep)
807 {
808 	struct libusb20_transfer *xfer;
809 
810 	xfer = usb_get_transfer_by_ep_no(dev, ep);
811 	if (xfer == NULL)
812 		return (-1);
813 
814 	libusb20_tr_clear_stall_sync(xfer);
815 
816 	return (0);
817 }
818 
819 int
820 usb_reset(usb_dev_handle * dev)
821 {
822 	int err;
823 
824 	err = libusb20_dev_reset((void *)dev);
825 
826 	if (err)
827 		return (-1);
828 
829 	/*
830 	 * Be compatible with LibUSB from sourceforge and close the
831 	 * handle after reset!
832 	 */
833 	return (usb_close(dev));
834 }
835 
836 int
837 usb_check_connected(usb_dev_handle * dev)
838 {
839 	int err;
840 
841 	err = libusb20_dev_check_connected((void *)dev);
842 
843 	if (err)
844 		return (-1);
845 
846 	return (0);
847 }
848 
849 const char *
850 usb_strerror(void)
851 {
852 	/* TODO */
853 	return ("Unknown error");
854 }
855 
856 void
857 usb_init(void)
858 {
859 	/* nothing to do */
860 	return;
861 }
862 
863 void
864 usb_set_debug(int level)
865 {
866 	/* use kernel UGEN debugging if you need to see what is going on */
867 	return;
868 }
869 
870 int
871 usb_find_busses(void)
872 {
873 	usb_busses = &usb_global_bus;
874 	return (1);
875 }
876 
877 int
878 usb_find_devices(void)
879 {
880 	struct libusb20_device *pdev;
881 	struct usb_device *udev;
882 	struct LIBUSB20_DEVICE_DESC_DECODED *ddesc;
883 	int devnum;
884 	int err;
885 
886 	/* cleanup after last device search */
887 	/* close all opened devices, if any */
888 
889 	while ((pdev = libusb20_be_device_foreach(usb_backend, NULL))) {
890 		udev = pdev->privLuData;
891 		libusb20_be_dequeue_device(usb_backend, pdev);
892 		libusb20_dev_free(pdev);
893 		if (udev != NULL) {
894 			LIST_DEL(usb_global_bus.devices, udev);
895 			free(udev);
896 		}
897 	}
898 
899 	/* free old USB backend, if any */
900 
901 	libusb20_be_free(usb_backend);
902 
903 	/* do a new backend device search */
904 	usb_backend = libusb20_be_alloc_default();
905 	if (usb_backend == NULL) {
906 		return (-1);
907 	}
908 	/* iterate all devices */
909 
910 	devnum = 1;
911 	pdev = NULL;
912 	while ((pdev = libusb20_be_device_foreach(usb_backend, pdev))) {
913 		udev = malloc(sizeof(*udev));
914 		if (udev == NULL)
915 			break;
916 
917 		memset(udev, 0, sizeof(*udev));
918 
919 		udev->bus = &usb_global_bus;
920 
921 		snprintf(udev->filename, sizeof(udev->filename),
922 		    "/dev/ugen%u.%u",
923 		    libusb20_dev_get_bus_number(pdev),
924 		    libusb20_dev_get_address(pdev));
925 
926 		ddesc = libusb20_dev_get_device_desc(pdev);
927 
928 		udev->descriptor.bLength = sizeof(udev->descriptor);
929 		udev->descriptor.bDescriptorType = ddesc->bDescriptorType;
930 		udev->descriptor.bcdUSB = ddesc->bcdUSB;
931 		udev->descriptor.bDeviceClass = ddesc->bDeviceClass;
932 		udev->descriptor.bDeviceSubClass = ddesc->bDeviceSubClass;
933 		udev->descriptor.bDeviceProtocol = ddesc->bDeviceProtocol;
934 		udev->descriptor.bMaxPacketSize0 = ddesc->bMaxPacketSize0;
935 		udev->descriptor.idVendor = ddesc->idVendor;
936 		udev->descriptor.idProduct = ddesc->idProduct;
937 		udev->descriptor.bcdDevice = ddesc->bcdDevice;
938 		udev->descriptor.iManufacturer = ddesc->iManufacturer;
939 		udev->descriptor.iProduct = ddesc->iProduct;
940 		udev->descriptor.iSerialNumber = ddesc->iSerialNumber;
941 		udev->descriptor.bNumConfigurations =
942 		    ddesc->bNumConfigurations;
943 		if (udev->descriptor.bNumConfigurations > USB_MAXCONFIG) {
944 			/* truncate number of configurations */
945 			udev->descriptor.bNumConfigurations = USB_MAXCONFIG;
946 		}
947 		udev->devnum = devnum++;
948 		/* link together the two structures */
949 		udev->dev = pdev;
950 		pdev->privLuData = udev;
951 
952 		err = libusb20_dev_open(pdev, 0);
953 		if (err == 0) {
954 			/* XXX get all config descriptors by default */
955 			usb_fetch_and_parse_descriptors((void *)pdev);
956 			libusb20_dev_close(pdev);
957 		}
958 		LIST_ADD(usb_global_bus.devices, udev);
959 	}
960 
961 	return (devnum - 1);			/* success */
962 }
963 
964 struct usb_device *
965 usb_device(usb_dev_handle * dev)
966 {
967 	struct libusb20_device *pdev;
968 
969 	pdev = (void *)dev;
970 
971 	return (pdev->privLuData);
972 }
973 
974 struct usb_bus *
975 usb_get_busses(void)
976 {
977 	return (usb_busses);
978 }
979 
980 int
981 usb_get_driver_np(usb_dev_handle * dev, int interface, char *name, int namelen)
982 {
983 	struct libusb20_device *pdev;
984 	char *ptr;
985 	int err;
986 
987 	pdev = (void *)dev;
988 
989 	if (pdev == NULL)
990 		return (-1);
991 	if (namelen < 1)
992 		return (-1);
993 	if (namelen > 255)
994 		namelen = 255;
995 
996 	err = libusb20_dev_get_iface_desc(pdev, interface, name, namelen);
997 	if (err != 0)
998 		return (-1);
999 
1000 	/* we only want the driver name */
1001 	ptr = strstr(name, ":");
1002 	if (ptr != NULL)
1003 		*ptr = 0;
1004 
1005 	return (0);
1006 }
1007 
1008 int
1009 usb_detach_kernel_driver_np(usb_dev_handle * dev, int interface)
1010 {
1011 	struct libusb20_device *pdev;
1012 	int err;
1013 
1014 	pdev = (void *)dev;
1015 
1016 	if (pdev == NULL)
1017 		return (-1);
1018 
1019 	err = libusb20_dev_detach_kernel_driver(pdev, interface);
1020 	if (err != 0)
1021 		return (-1);
1022 
1023 	return (0);
1024 }
1025