xref: /freebsd/sys/dev/usb/usb_handle_request.c (revision 02e9120893770924227138ba49df1edb3896112a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2008 Hans Petter Selasky. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #ifdef USB_GLOBAL_INCLUDE_FILE
29 #include USB_GLOBAL_INCLUDE_FILE
30 #else
31 #include <sys/stdint.h>
32 #include <sys/stddef.h>
33 #include <sys/param.h>
34 #include <sys/queue.h>
35 #include <sys/types.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/bus.h>
39 #include <sys/module.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/condvar.h>
43 #include <sys/sysctl.h>
44 #include <sys/sx.h>
45 #include <sys/unistd.h>
46 #include <sys/callout.h>
47 #include <sys/malloc.h>
48 #include <sys/priv.h>
49 
50 #include <dev/usb/usb.h>
51 #include <dev/usb/usbdi.h>
52 #include <dev/usb/usbdi_util.h>
53 #include "usb_if.h"
54 
55 #define	USB_DEBUG_VAR usb_debug
56 
57 #include <dev/usb/usb_core.h>
58 #include <dev/usb/usb_process.h>
59 #include <dev/usb/usb_busdma.h>
60 #include <dev/usb/usb_transfer.h>
61 #include <dev/usb/usb_device.h>
62 #include <dev/usb/usb_debug.h>
63 #include <dev/usb/usb_dynamic.h>
64 #include <dev/usb/usb_hub.h>
65 
66 #include <dev/usb/usb_controller.h>
67 #include <dev/usb/usb_bus.h>
68 #endif			/* USB_GLOBAL_INCLUDE_FILE */
69 
70 /* function prototypes */
71 
72 static uint8_t usb_handle_get_stall(struct usb_device *, uint8_t);
73 static usb_error_t	 usb_handle_remote_wakeup(struct usb_xfer *, uint8_t);
74 static usb_error_t	 usb_handle_request(struct usb_xfer *);
75 static usb_error_t	 usb_handle_set_config(struct usb_xfer *, uint8_t);
76 static usb_error_t	 usb_handle_set_stall(struct usb_xfer *, uint8_t,
77 			    uint8_t);
78 static usb_error_t	 usb_handle_iface_request(struct usb_xfer *, void **,
79 			    uint16_t *, struct usb_device_request, uint16_t,
80 			    uint8_t);
81 
82 /*------------------------------------------------------------------------*
83  *	usb_handle_request_callback
84  *
85  * This function is the USB callback for generic USB Device control
86  * transfers.
87  *------------------------------------------------------------------------*/
88 void
89 usb_handle_request_callback(struct usb_xfer *xfer, usb_error_t error)
90 {
91 	usb_error_t err;
92 
93 	/* check the current transfer state */
94 
95 	switch (USB_GET_STATE(xfer)) {
96 	case USB_ST_SETUP:
97 	case USB_ST_TRANSFERRED:
98 
99 		/* handle the request */
100 		err = usb_handle_request(xfer);
101 
102 		if (err) {
103 			if (err == USB_ERR_BAD_CONTEXT) {
104 				/* we need to re-setup the control transfer */
105 				usb_needs_explore(xfer->xroot->bus, 0);
106 				break;
107 			}
108 			goto tr_restart;
109 		}
110 		usbd_transfer_submit(xfer);
111 		break;
112 
113 	default:
114 		/* check if a control transfer is active */
115 		if (xfer->flags_int.control_rem != 0xFFFF) {
116 			/* handle the request */
117 			err = usb_handle_request(xfer);
118 		}
119 		if (xfer->error != USB_ERR_CANCELLED) {
120 			/* should not happen - try stalling */
121 			goto tr_restart;
122 		}
123 		break;
124 	}
125 	return;
126 
127 tr_restart:
128 	/*
129 	 * If a control transfer is active, stall it, and wait for the
130 	 * next control transfer.
131 	 */
132 	usbd_xfer_set_frame_len(xfer, 0, sizeof(struct usb_device_request));
133 	xfer->nframes = 1;
134 	xfer->flags.manual_status = 1;
135 	xfer->flags.force_short_xfer = 0;
136 	usbd_xfer_set_stall(xfer);	/* cancel previous transfer, if any */
137 	usbd_transfer_submit(xfer);
138 }
139 
140 /*------------------------------------------------------------------------*
141  *	usb_handle_set_config
142  *
143  * Returns:
144  *    0: Success
145  * Else: Failure
146  *------------------------------------------------------------------------*/
147 static usb_error_t
148 usb_handle_set_config(struct usb_xfer *xfer, uint8_t conf_no)
149 {
150 	struct usb_device *udev = xfer->xroot->udev;
151 	usb_error_t err = 0;
152 	uint8_t do_unlock;
153 
154 	/*
155 	 * We need to protect against other threads doing probe and
156 	 * attach:
157 	 */
158 	USB_XFER_UNLOCK(xfer);
159 
160 	/* Prevent re-enumeration */
161 	do_unlock = usbd_enum_lock(udev);
162 
163 	if (conf_no == USB_UNCONFIG_NO) {
164 		conf_no = USB_UNCONFIG_INDEX;
165 	} else {
166 		/*
167 		 * The relationship between config number and config index
168 		 * is very simple in our case:
169 		 */
170 		conf_no--;
171 	}
172 
173 	if (usbd_set_config_index(udev, conf_no)) {
174 		DPRINTF("set config %d failed\n", conf_no);
175 		err = USB_ERR_STALLED;
176 		goto done;
177 	}
178 	if (usb_probe_and_attach(udev, USB_IFACE_INDEX_ANY)) {
179 		DPRINTF("probe and attach failed\n");
180 		err = USB_ERR_STALLED;
181 		goto done;
182 	}
183 done:
184 	if (do_unlock)
185 		usbd_enum_unlock(udev);
186 	USB_XFER_LOCK(xfer);
187 	return (err);
188 }
189 
190 static usb_error_t
191 usb_check_alt_setting(struct usb_device *udev,
192      struct usb_interface *iface, uint8_t alt_index)
193 {
194 	uint8_t do_unlock;
195 	usb_error_t err = 0;
196 
197 	/* Prevent re-enumeration */
198 	do_unlock = usbd_enum_lock(udev);
199 
200 	if (alt_index >= usbd_get_no_alts(udev->cdesc, iface->idesc))
201 		err = USB_ERR_INVAL;
202 
203 	if (do_unlock)
204 		usbd_enum_unlock(udev);
205 
206 	return (err);
207 }
208 
209 /*------------------------------------------------------------------------*
210  *	usb_handle_iface_request
211  *
212  * Returns:
213  *    0: Success
214  * Else: Failure
215  *------------------------------------------------------------------------*/
216 static usb_error_t
217 usb_handle_iface_request(struct usb_xfer *xfer,
218     void **ppdata, uint16_t *plen,
219     struct usb_device_request req, uint16_t off, uint8_t state)
220 {
221 	struct usb_interface *iface;
222 	struct usb_interface *iface_parent;	/* parent interface */
223 	struct usb_device *udev = xfer->xroot->udev;
224 	int error;
225 	uint8_t iface_index;
226 	uint8_t temp_state;
227 	uint8_t do_unlock;
228 
229 	if ((req.bmRequestType & 0x1F) == UT_INTERFACE) {
230 		iface_index = req.wIndex[0];	/* unicast */
231 	} else {
232 		iface_index = 0;	/* broadcast */
233 	}
234 
235 	/*
236 	 * We need to protect against other threads doing probe and
237 	 * attach:
238 	 */
239 	USB_XFER_UNLOCK(xfer);
240 
241 	/* Prevent re-enumeration */
242 	do_unlock = usbd_enum_lock(udev);
243 
244 	error = ENXIO;
245 
246 tr_repeat:
247 	iface = usbd_get_iface(udev, iface_index);
248 	if ((iface == NULL) ||
249 	    (iface->idesc == NULL)) {
250 		/* end of interfaces non-existing interface */
251 		goto tr_stalled;
252 	}
253 	/* set initial state */
254 
255 	temp_state = state;
256 
257 	/* forward request to interface, if any */
258 
259 	if ((error != 0) &&
260 	    (error != ENOTTY) &&
261 	    (iface->subdev != NULL) &&
262 	    device_is_attached(iface->subdev)) {
263 #if 0
264 		DEVMETHOD(usb_handle_request, NULL);	/* dummy */
265 #endif
266 		error = USB_HANDLE_REQUEST(iface->subdev,
267 		    &req, ppdata, plen,
268 		    off, &temp_state);
269 	}
270 	iface_parent = usbd_get_iface(udev, iface->parent_iface_index);
271 
272 	if ((iface_parent == NULL) ||
273 	    (iface_parent->idesc == NULL)) {
274 		/* non-existing interface */
275 		iface_parent = NULL;
276 	}
277 	/* forward request to parent interface, if any */
278 
279 	if ((error != 0) &&
280 	    (error != ENOTTY) &&
281 	    (iface_parent != NULL) &&
282 	    (iface_parent->subdev != NULL) &&
283 	    ((req.bmRequestType & 0x1F) == UT_INTERFACE) &&
284 	    (iface_parent->subdev != iface->subdev) &&
285 	    device_is_attached(iface_parent->subdev)) {
286 		error = USB_HANDLE_REQUEST(iface_parent->subdev,
287 		    &req, ppdata, plen, off, &temp_state);
288 	}
289 	if (error == 0) {
290 		/* negativly adjust pointer and length */
291 		*ppdata = ((uint8_t *)(*ppdata)) - off;
292 		*plen += off;
293 
294 		if ((state == USB_HR_NOT_COMPLETE) &&
295 		    (temp_state == USB_HR_COMPLETE_OK))
296 			goto tr_short;
297 		else
298 			goto tr_valid;
299 	} else if (error == ENOTTY) {
300 		goto tr_stalled;
301 	}
302 	if ((req.bmRequestType & 0x1F) != UT_INTERFACE) {
303 		iface_index++;		/* iterate */
304 		goto tr_repeat;
305 	}
306 	if (state != USB_HR_NOT_COMPLETE) {
307 		/* we are complete */
308 		goto tr_valid;
309 	}
310 	switch (req.bmRequestType) {
311 	case UT_WRITE_INTERFACE:
312 		switch (req.bRequest) {
313 		case UR_SET_INTERFACE:
314 			/*
315 			 * We assume that the endpoints are the same
316 			 * across the alternate settings.
317 			 *
318 			 * Reset the endpoints, because re-attaching
319 			 * only a part of the device is not possible.
320 			 */
321 			error = usb_check_alt_setting(udev,
322 			    iface, req.wValue[0]);
323 			if (error) {
324 				DPRINTF("alt setting does not exist %s\n",
325 				    usbd_errstr(error));
326 				goto tr_stalled;
327 			}
328 			error = usb_reset_iface_endpoints(udev, iface_index);
329 			if (error) {
330 				DPRINTF("alt setting failed %s\n",
331 				    usbd_errstr(error));
332 				goto tr_stalled;
333 			}
334 			/* update the current alternate setting */
335 			iface->alt_index = req.wValue[0];
336 			break;
337 
338 		default:
339 			goto tr_stalled;
340 		}
341 		break;
342 
343 	case UT_READ_INTERFACE:
344 		switch (req.bRequest) {
345 		case UR_GET_INTERFACE:
346 			*ppdata = &iface->alt_index;
347 			*plen = 1;
348 			break;
349 
350 		default:
351 			goto tr_stalled;
352 		}
353 		break;
354 	default:
355 		goto tr_stalled;
356 	}
357 tr_valid:
358 	if (do_unlock)
359 		usbd_enum_unlock(udev);
360 	USB_XFER_LOCK(xfer);
361 	return (0);
362 
363 tr_short:
364 	if (do_unlock)
365 		usbd_enum_unlock(udev);
366 	USB_XFER_LOCK(xfer);
367 	return (USB_ERR_SHORT_XFER);
368 
369 tr_stalled:
370 	if (do_unlock)
371 		usbd_enum_unlock(udev);
372 	USB_XFER_LOCK(xfer);
373 	return (USB_ERR_STALLED);
374 }
375 
376 /*------------------------------------------------------------------------*
377  *	usb_handle_stall
378  *
379  * Returns:
380  *    0: Success
381  * Else: Failure
382  *------------------------------------------------------------------------*/
383 static usb_error_t
384 usb_handle_set_stall(struct usb_xfer *xfer, uint8_t ep, uint8_t do_stall)
385 {
386 	struct usb_device *udev = xfer->xroot->udev;
387 	usb_error_t err;
388 
389 	USB_XFER_UNLOCK(xfer);
390 	err = usbd_set_endpoint_stall(udev,
391 	    usbd_get_ep_by_addr(udev, ep), do_stall);
392 	USB_XFER_LOCK(xfer);
393 	return (err);
394 }
395 
396 /*------------------------------------------------------------------------*
397  *	usb_handle_get_stall
398  *
399  * Returns:
400  *    0: Success
401  * Else: Failure
402  *------------------------------------------------------------------------*/
403 static uint8_t
404 usb_handle_get_stall(struct usb_device *udev, uint8_t ea_val)
405 {
406 	struct usb_endpoint *ep;
407 	uint8_t halted;
408 
409 	ep = usbd_get_ep_by_addr(udev, ea_val);
410 	if (ep == NULL) {
411 		/* nothing to do */
412 		return (0);
413 	}
414 	USB_BUS_LOCK(udev->bus);
415 	halted = ep->is_stalled;
416 	USB_BUS_UNLOCK(udev->bus);
417 
418 	return (halted);
419 }
420 
421 /*------------------------------------------------------------------------*
422  *	usb_handle_remote_wakeup
423  *
424  * Returns:
425  *    0: Success
426  * Else: Failure
427  *------------------------------------------------------------------------*/
428 static usb_error_t
429 usb_handle_remote_wakeup(struct usb_xfer *xfer, uint8_t is_on)
430 {
431 	struct usb_device *udev;
432 	struct usb_bus *bus;
433 
434 	udev = xfer->xroot->udev;
435 	bus = udev->bus;
436 
437 	USB_BUS_LOCK(bus);
438 
439 	if (is_on) {
440 		udev->flags.remote_wakeup = 1;
441 	} else {
442 		udev->flags.remote_wakeup = 0;
443 	}
444 
445 	USB_BUS_UNLOCK(bus);
446 
447 #if USB_HAVE_POWERD
448 	/* In case we are out of sync, update the power state. */
449 	usb_bus_power_update(udev->bus);
450 #endif
451 	return (0);			/* success */
452 }
453 
454 /*------------------------------------------------------------------------*
455  *	usb_handle_request
456  *
457  * Internal state sequence:
458  *
459  * USB_HR_NOT_COMPLETE -> USB_HR_COMPLETE_OK v USB_HR_COMPLETE_ERR
460  *
461  * Returns:
462  * 0: Ready to start hardware
463  * Else: Stall current transfer, if any
464  *------------------------------------------------------------------------*/
465 static usb_error_t
466 usb_handle_request(struct usb_xfer *xfer)
467 {
468 	struct usb_device_request req;
469 	struct usb_device *udev;
470 	const void *src_zcopy;		/* zero-copy source pointer */
471 	const void *src_mcopy;		/* non zero-copy source pointer */
472 	uint16_t off;			/* data offset */
473 	uint16_t rem;			/* data remainder */
474 	uint16_t max_len;		/* max fragment length */
475 	uint16_t wValue;
476 	uint8_t state;
477 	uint8_t is_complete = 1;
478 	usb_error_t err;
479 	union {
480 		uWord	wStatus;
481 		uint8_t	buf[2];
482 	}     temp;
483 
484 	/*
485 	 * Filter the USB transfer state into
486 	 * something which we understand:
487 	 */
488 
489 	switch (USB_GET_STATE(xfer)) {
490 	case USB_ST_SETUP:
491 		state = USB_HR_NOT_COMPLETE;
492 
493 		if (!xfer->flags_int.control_act) {
494 			/* nothing to do */
495 			goto tr_stalled;
496 		}
497 		break;
498 	case USB_ST_TRANSFERRED:
499 		if (!xfer->flags_int.control_act) {
500 			state = USB_HR_COMPLETE_OK;
501 		} else {
502 			state = USB_HR_NOT_COMPLETE;
503 		}
504 		break;
505 	default:
506 		state = USB_HR_COMPLETE_ERR;
507 		break;
508 	}
509 
510 	/* reset frame stuff */
511 
512 	usbd_xfer_set_frame_len(xfer, 0, 0);
513 
514 	usbd_xfer_set_frame_offset(xfer, 0, 0);
515 	usbd_xfer_set_frame_offset(xfer, sizeof(req), 1);
516 
517 	/* get the current request, if any */
518 
519 	usbd_copy_out(xfer->frbuffers, 0, &req, sizeof(req));
520 
521 	if (xfer->flags_int.control_rem == 0xFFFF) {
522 		/* first time - not initialised */
523 		rem = UGETW(req.wLength);
524 		off = 0;
525 	} else {
526 		/* not first time - initialised */
527 		rem = xfer->flags_int.control_rem;
528 		off = UGETW(req.wLength) - rem;
529 	}
530 
531 	/* set some defaults */
532 
533 	max_len = 0;
534 	src_zcopy = NULL;
535 	src_mcopy = NULL;
536 	udev = xfer->xroot->udev;
537 
538 	/* get some request fields decoded */
539 
540 	wValue = UGETW(req.wValue);
541 
542 	DPRINTF("req 0x%02x 0x%02x 0x%04x 0x%04x "
543 	    "off=0x%x rem=0x%x, state=%d\n", req.bmRequestType,
544 	    req.bRequest, wValue, UGETW(req.wIndex), off, rem, state);
545 
546 	/* demultiplex the control request */
547 
548 	switch (req.bmRequestType) {
549 	case UT_READ_DEVICE:
550 		if (state != USB_HR_NOT_COMPLETE) {
551 			break;
552 		}
553 		switch (req.bRequest) {
554 		case UR_GET_DESCRIPTOR:
555 			goto tr_handle_get_descriptor;
556 		case UR_GET_CONFIG:
557 			goto tr_handle_get_config;
558 		case UR_GET_STATUS:
559 			goto tr_handle_get_status;
560 		default:
561 			goto tr_stalled;
562 		}
563 		break;
564 
565 	case UT_WRITE_DEVICE:
566 		switch (req.bRequest) {
567 		case UR_SET_ADDRESS:
568 			goto tr_handle_set_address;
569 		case UR_SET_CONFIG:
570 			goto tr_handle_set_config;
571 		case UR_CLEAR_FEATURE:
572 			switch (wValue) {
573 			case UF_DEVICE_REMOTE_WAKEUP:
574 				goto tr_handle_clear_wakeup;
575 			default:
576 				goto tr_stalled;
577 			}
578 			break;
579 		case UR_SET_FEATURE:
580 			switch (wValue) {
581 			case UF_DEVICE_REMOTE_WAKEUP:
582 				goto tr_handle_set_wakeup;
583 			default:
584 				goto tr_stalled;
585 			}
586 			break;
587 		default:
588 			goto tr_stalled;
589 		}
590 		break;
591 
592 	case UT_WRITE_ENDPOINT:
593 		switch (req.bRequest) {
594 		case UR_CLEAR_FEATURE:
595 			switch (wValue) {
596 			case UF_ENDPOINT_HALT:
597 				goto tr_handle_clear_halt;
598 			default:
599 				goto tr_stalled;
600 			}
601 			break;
602 		case UR_SET_FEATURE:
603 			switch (wValue) {
604 			case UF_ENDPOINT_HALT:
605 				goto tr_handle_set_halt;
606 			default:
607 				goto tr_stalled;
608 			}
609 			break;
610 		default:
611 			goto tr_stalled;
612 		}
613 		break;
614 
615 	case UT_READ_ENDPOINT:
616 		switch (req.bRequest) {
617 		case UR_GET_STATUS:
618 			goto tr_handle_get_ep_status;
619 		default:
620 			goto tr_stalled;
621 		}
622 		break;
623 	default:
624 		/* we use "USB_ADD_BYTES" to de-const the src_zcopy */
625 		err = usb_handle_iface_request(xfer,
626 		    USB_ADD_BYTES(&src_zcopy, 0),
627 		    &max_len, req, off, state);
628 		if (err == 0) {
629 			is_complete = 0;
630 			goto tr_valid;
631 		} else if (err == USB_ERR_SHORT_XFER) {
632 			goto tr_valid;
633 		}
634 		/*
635 		 * Reset zero-copy pointer and max length
636 		 * variable in case they were unintentionally
637 		 * set:
638 		 */
639 		src_zcopy = NULL;
640 		max_len = 0;
641 
642 		/*
643 		 * Check if we have a vendor specific
644 		 * descriptor:
645 		 */
646 		goto tr_handle_get_descriptor;
647 	}
648 	goto tr_valid;
649 
650 tr_handle_get_descriptor:
651 	err = (usb_temp_get_desc_p) (udev, &req, &src_zcopy, &max_len);
652 	if (err)
653 		goto tr_stalled;
654 	if (src_zcopy == NULL)
655 		goto tr_stalled;
656 	goto tr_valid;
657 
658 tr_handle_get_config:
659 	temp.buf[0] = udev->curr_config_no;
660 	src_mcopy = temp.buf;
661 	max_len = 1;
662 	goto tr_valid;
663 
664 tr_handle_get_status:
665 
666 	wValue = 0;
667 
668 	USB_BUS_LOCK(udev->bus);
669 	if (udev->flags.remote_wakeup) {
670 		wValue |= UDS_REMOTE_WAKEUP;
671 	}
672 	if (udev->flags.self_powered) {
673 		wValue |= UDS_SELF_POWERED;
674 	}
675 	USB_BUS_UNLOCK(udev->bus);
676 
677 	USETW(temp.wStatus, wValue);
678 	src_mcopy = temp.wStatus;
679 	max_len = sizeof(temp.wStatus);
680 	goto tr_valid;
681 
682 tr_handle_set_address:
683 	if (state == USB_HR_NOT_COMPLETE) {
684 		if (wValue >= 0x80) {
685 			/* invalid value */
686 			goto tr_stalled;
687 		} else if (udev->curr_config_no != 0) {
688 			/* we are configured ! */
689 			goto tr_stalled;
690 		}
691 	} else if (state != USB_HR_NOT_COMPLETE) {
692 		udev->address = (wValue & 0x7F);
693 		goto tr_bad_context;
694 	}
695 	goto tr_valid;
696 
697 tr_handle_set_config:
698 	if (state == USB_HR_NOT_COMPLETE) {
699 		if (usb_handle_set_config(xfer, req.wValue[0])) {
700 			goto tr_stalled;
701 		}
702 	}
703 	goto tr_valid;
704 
705 tr_handle_clear_halt:
706 	if (state == USB_HR_NOT_COMPLETE) {
707 		if (usb_handle_set_stall(xfer, req.wIndex[0], 0)) {
708 			goto tr_stalled;
709 		}
710 	}
711 	goto tr_valid;
712 
713 tr_handle_clear_wakeup:
714 	if (state == USB_HR_NOT_COMPLETE) {
715 		if (usb_handle_remote_wakeup(xfer, 0)) {
716 			goto tr_stalled;
717 		}
718 	}
719 	goto tr_valid;
720 
721 tr_handle_set_halt:
722 	if (state == USB_HR_NOT_COMPLETE) {
723 		if (usb_handle_set_stall(xfer, req.wIndex[0], 1)) {
724 			goto tr_stalled;
725 		}
726 	}
727 	goto tr_valid;
728 
729 tr_handle_set_wakeup:
730 	if (state == USB_HR_NOT_COMPLETE) {
731 		if (usb_handle_remote_wakeup(xfer, 1)) {
732 			goto tr_stalled;
733 		}
734 	}
735 	goto tr_valid;
736 
737 tr_handle_get_ep_status:
738 	if (state == USB_HR_NOT_COMPLETE) {
739 		temp.wStatus[0] =
740 		    usb_handle_get_stall(udev, req.wIndex[0]);
741 		temp.wStatus[1] = 0;
742 		src_mcopy = temp.wStatus;
743 		max_len = sizeof(temp.wStatus);
744 	}
745 	goto tr_valid;
746 
747 tr_valid:
748 	if (state != USB_HR_NOT_COMPLETE) {
749 		goto tr_stalled;
750 	}
751 	/* subtract offset from length */
752 
753 	max_len -= off;
754 
755 	/* Compute the real maximum data length */
756 
757 	if (max_len > xfer->max_data_length) {
758 		max_len = usbd_xfer_max_len(xfer);
759 	}
760 	if (max_len > rem) {
761 		max_len = rem;
762 	}
763 	/*
764 	 * If the remainder is greater than the maximum data length,
765 	 * we need to truncate the value for the sake of the
766 	 * comparison below:
767 	 */
768 	if (rem > xfer->max_data_length) {
769 		rem = usbd_xfer_max_len(xfer);
770 	}
771 	if ((rem != max_len) && (is_complete != 0)) {
772 		/*
773 	         * If we don't transfer the data we can transfer, then
774 	         * the transfer is short !
775 	         */
776 		xfer->flags.force_short_xfer = 1;
777 		xfer->nframes = 2;
778 	} else {
779 		/*
780 		 * Default case
781 		 */
782 		xfer->flags.force_short_xfer = 0;
783 		xfer->nframes = max_len ? 2 : 1;
784 	}
785 	if (max_len > 0) {
786 		if (src_mcopy) {
787 			src_mcopy = USB_ADD_BYTES(src_mcopy, off);
788 			usbd_copy_in(xfer->frbuffers + 1, 0,
789 			    src_mcopy, max_len);
790 			usbd_xfer_set_frame_len(xfer, 1, max_len);
791 		} else {
792 			usbd_xfer_set_frame_data(xfer, 1,
793 			    USB_ADD_BYTES(src_zcopy, off), max_len);
794 		}
795 	} else {
796 		/* the end is reached, send status */
797 		xfer->flags.manual_status = 0;
798 		usbd_xfer_set_frame_len(xfer, 1, 0);
799 	}
800 	DPRINTF("success\n");
801 	return (0);			/* success */
802 
803 tr_stalled:
804 	DPRINTF("%s\n", (state != USB_HR_NOT_COMPLETE) ?
805 	    "complete" : "stalled");
806 	return (USB_ERR_STALLED);
807 
808 tr_bad_context:
809 	DPRINTF("bad context\n");
810 	return (USB_ERR_BAD_CONTEXT);
811 }
812