aboutsummaryrefslogtreecommitdiff
path: root/drivers/staging/usbip/stub_rx.c
blob: 00e475c51a120f6a67532b3786044bb59cedf0f6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */

#include <asm/byteorder.h>
#include <linux/kthread.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>

#include "usbip_common.h"
#include "stub.h"

static int is_clear_halt_cmd(struct urb *urb)
{
	struct usb_ctrlrequest *req;

	req = (struct usb_ctrlrequest *) urb->setup_packet;

	 return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
		 (req->bRequestType == USB_RECIP_ENDPOINT) &&
		 (req->wValue == USB_ENDPOINT_HALT);
}

static int is_set_interface_cmd(struct urb *urb)
{
	struct usb_ctrlrequest *req;

	req = (struct usb_ctrlrequest *) urb->setup_packet;

	return (req->bRequest == USB_REQ_SET_INTERFACE) &&
		(req->bRequestType == USB_RECIP_INTERFACE);
}

static int is_set_configuration_cmd(struct urb *urb)
{
	struct usb_ctrlrequest *req;

	req = (struct usb_ctrlrequest *) urb->setup_packet;

	return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
		(req->bRequestType == USB_RECIP_DEVICE);
}

static int is_reset_device_cmd(struct urb *urb)
{
	struct usb_ctrlrequest *req;
	__u16 value;
	__u16 index;

	req = (struct usb_ctrlrequest *) urb->setup_packet;
	value = le16_to_cpu(req->wValue);
	index = le16_to_cpu(req->wIndex);

	if ((req->bRequest == USB_REQ_SET_FEATURE) &&
	    (req->bRequestType == USB_RT_PORT) &&
	    (value == USB_PORT_FEAT_RESET)) {
		usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
		return 1;
	} else
		return 0;
}

static int tweak_clear_halt_cmd(struct urb *urb)
{
	struct usb_ctrlrequest *req;
	int target_endp;
	int target_dir;
	int target_pipe;
	int ret;

	req = (struct usb_ctrlrequest *) urb->setup_packet;

	/*
	 * The stalled endpoint is specified in the wIndex value. The endpoint
	 * of the urb is the target of this clear_halt request (i.e., control
	 * endpoint).
	 */
	target_endp = le16_to_cpu(req->wIndex) & 0x000f;

	/* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
	target_dir = le16_to_cpu(req->wIndex) & 0x0080;

	if (target_dir)
		target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
	else
		target_pipe = usb_sndctrlpipe(urb->dev, target_endp);

	ret = usb_clear_halt(urb->dev, target_pipe);
	if (ret < 0)
		dev_err(&urb->dev->dev,
			"usb_clear_halt error: devnum %d endp %d ret %d\n",
			urb->dev->devnum, target_endp, ret);
	else
		dev_info(&urb->dev->dev,
			 "usb_clear_halt done: devnum %d endp %d\n",
			 urb->dev->devnum, target_endp);

	return ret;
}

static int tweak_set_interface_cmd(struct urb *urb)
{
	struct usb_ctrlrequest *req;
	__u16 alternate;
	__u16 interface;
	int ret;

	req = (struct usb_ctrlrequest *) urb->setup_packet;
	alternate = le16_to_cpu(req->wValue);
	interface = le16_to_cpu(req->wIndex);

	usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
			  interface, alternate);

	ret = usb_set_interface(urb->dev, interface, alternate);
	if (ret < 0)
		dev_err(&urb->dev->dev,
			"usb_set_interface error: inf %u alt %u ret %d\n",
			interface, alternate, ret);
	else
		dev_info(&urb->dev->dev,
			"usb_set_interface done: inf %u alt %u\n",
			interface, alternate);

	return ret;
}

static int tweak_set_configuration_cmd(struct urb *urb)
{
	struct stub_priv *priv = (struct stub_priv *) urb->context;
	struct stub_device *sdev = priv->sdev;
	struct usb_ctrlrequest *req;
	__u16 config;
	int err;

	req = (struct usb_ctrlrequest *) urb->setup_packet;
	config = le16_to_cpu(req->wValue);

	err = usb_set_configuration(sdev->udev, config);
	if (err && err != -ENODEV)
		dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
			config, err);
	return 0;
}

static int tweak_reset_device_cmd(struct urb *urb)
{
	struct stub_priv *priv = (struct stub_priv *) urb->context;
	struct stub_device *sdev = priv->sdev;

	dev_info(&urb->dev->dev, "usb_queue_reset_device\n");

	/*
	 * With the implementation of pre_reset and post_reset the driver no
	 * longer unbinds. This allows the use of synchronous reset.
	 */

	if (usb_lock_device_for_reset(sdev->udev, sdev->interface) < 0) {
		dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
		return 0;
	}
	usb_reset_device(sdev->udev);
	usb_unlock_device(sdev->udev);

	return 0;
}

/*
 * clear_halt, set_interface, and set_configuration require special tricks.
 */
static void tweak_special_requests(struct urb *urb)
{
	if (!urb || !urb->setup_packet)
		return;

	if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
		return;

	if (is_clear_halt_cmd(urb))
		/* tweak clear_halt */
		 tweak_clear_halt_cmd(urb);

	else if (is_set_interface_cmd(urb))
		/* tweak set_interface */
		tweak_set_interface_cmd(urb);

	else if (is_set_configuration_cmd(urb))
		/* tweak set_configuration */
		tweak_set_configuration_cmd(urb);

	else if (is_reset_device_cmd(urb))
		tweak_reset_device_cmd(urb);
	else
		usbip_dbg_stub_rx("no need to tweak\n");
}

/*
 * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 * By unlinking the urb asynchronously, stub_rx can continuously
 * process coming urbs.  Even if the urb is unlinked, its completion
 * handler will be called and stub_tx will send a return pdu.
 *
 * See also comments about unlinking strategy in vhci_hcd.c.
 */
static int stub_recv_cmd_unlink(struct stub_device *sdev,
				struct usbip_header *pdu)
{
	int ret;
	unsigned long flags;
	struct stub_priv *priv;

	spin_lock_irqsave(&sdev->priv_lock, flags);

	list_for_each_entry(priv, &sdev->priv_init, list) {
		if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
			continue;

		dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
			 priv->urb);

		/*
		 * This matched urb is not completed yet (i.e., be in
		 * flight in usb hcd hardware/driver). Now we are
		 * cancelling it. The unlinking flag means that we are
		 * now not going to return the normal result pdu of a
		 * submission request, but going to return a result pdu
		 * of the unlink request.
		 */
		priv->unlinking = 1;

		/*
		 * In the case that unlinking flag is on, prev->seqnum
		 * is changed from the seqnum of the cancelling urb to
		 * the seqnum of the unlink request. This will be used
		 * to make the result pdu of the unlink request.
		 */
		priv->seqnum = pdu->base.seqnum;

		spin_unlock_irqrestore(&sdev->priv_lock, flags);

		/*
		 * usb_unlink_urb() is now out of spinlocking to avoid
		 * spinlock recursion since stub_complete() is
		 * sometimes called in this context but not in the
		 * interrupt context.  If stub_complete() is executed
		 * before we call usb_unlink_urb(), usb_unlink_urb()
		 * will return an error value. In this case, stub_tx
		 * will return the result pdu of this unlink request
		 * though submission is completed and actual unlinking
		 * is not executed. OK?
		 */
		/* In the above case, urb->status is not -ECONNRESET,
		 * so a driver in a client host will know the failure
		 * of the unlink request ?
		 */
		ret = usb_unlink_urb(priv->urb);
		if (ret != -EINPROGRESS)
			dev_err(&priv->urb->dev->dev,
				"failed to unlink a urb %p, ret %d\n",
				priv->urb, ret);

		return 0;
	}

	usbip_dbg_stub_rx("seqnum %d is not pending\n",
			  pdu->u.cmd_unlink.seqnum);

	/*
	 * The urb of the unlink target is not found in priv_init queue. It was
	 * already completed and its results is/was going to be sent by a
	 * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
	 * return the completeness of this unlink request to vhci_hcd.
	 */
	stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);

	spin_unlock_irqrestore(&sdev->priv_lock, flags);

	return 0;
}

static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
{
	struct usbip_device *ud = &sdev->ud;
	int valid = 0;

	if (pdu->base.devid == sdev->devid) {
		spin_lock_irq(&ud->lock);
		if (ud->status == SDEV_ST_USED) {
			/* A request is valid. */
			valid = 1;
		}
		spin_unlock_irq(&ud->lock);
	}

	return valid;
}

static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
					 struct usbip_header *pdu)
{
	struct stub_priv *priv;
	struct usbip_device *ud = &sdev->ud;
	unsigned long flags;

	spin_lock_irqsave(&sdev->priv_lock, flags);

	priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
	if (!priv) {
		dev_err(&sdev->interface->dev, "alloc stub_priv\n");
		spin_unlock_irqrestore(&sdev->priv_lock, flags);
		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
		return NULL;
	}

	priv->seqnum = pdu->base.seqnum;
	priv->sdev = sdev;

	/*
	 * After a stub_priv is linked to a list_head,
	 * our error handler can free allocated data.
	 */
	list_add_tail(&priv->list, &sdev->priv_init);

	spin_unlock_irqrestore(&sdev->priv_lock, flags);

	return priv;
}

static int get_pipe(struct stub_device *sdev, int epnum, int dir)
{
	struct usb_device *udev = sdev->udev;
	struct usb_host_endpoint *ep;
	struct usb_endpoint_descriptor *epd = NULL;

	if (dir == USBIP_DIR_IN)
		ep = udev->ep_in[epnum & 0x7f];
	else
		ep = udev->ep_out[epnum & 0x7f];
	if (!ep) {
		dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
			epnum);
		BUG();
	}

	epd = &ep->desc;
	if (usb_endpoint_xfer_control(epd)) {
		if (dir == USBIP_DIR_OUT)
			return usb_sndctrlpipe(udev, epnum);
		else
			return usb_rcvctrlpipe(udev, epnum);
	}

	if (usb_endpoint_xfer_bulk(epd)) {
		if (dir == USBIP_DIR_OUT)
			return usb_sndbulkpipe(udev, epnum);
		else
			return usb_rcvbulkpipe(udev, epnum);
	}

	if (usb_endpoint_xfer_int(epd)) {
		if (dir == USBIP_DIR_OUT)
			return usb_sndintpipe(udev, epnum);
		else
			return usb_rcvintpipe(udev, epnum);
	}

	if (usb_endpoint_xfer_isoc(epd)) {
		if (dir == USBIP_DIR_OUT)
			return usb_sndisocpipe(udev, epnum);
		else
			return usb_rcvisocpipe(udev, epnum);
	}

	/* NOT REACHED */
	dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
	return 0;
}

static void masking_bogus_flags(struct urb *urb)
{
	int				xfertype;
	struct usb_device		*dev;
	struct usb_host_endpoint	*ep;
	int				is_out;
	unsigned int	allowed;

	if (!urb || urb->hcpriv || !urb->complete)
		return;
	dev = urb->dev;
	if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
		return;

	ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
		[usb_pipeendpoint(urb->pipe)];
	if (!ep)
		return;

	xfertype = usb_endpoint_type(&ep->desc);
	if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
		struct usb_ctrlrequest *setup =
			(struct usb_ctrlrequest *) urb->setup_packet;

		if (!setup)
			return;
		is_out = !(setup->bRequestType & USB_DIR_IN) ||
			!setup->wLength;
	} else {
		is_out = usb_endpoint_dir_out(&ep->desc);
	}

	/* enforce simple/standard policy */
	allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
		   URB_DIR_MASK | URB_FREE_BUFFER);
	switch (xfertype) {
	case USB_ENDPOINT_XFER_BULK:
		if (is_out)
			allowed |= URB_ZERO_PACKET;
		/* FALLTHROUGH */
	case USB_ENDPOINT_XFER_CONTROL:
		allowed |= URB_NO_FSBR;	/* only affects UHCI */
		/* FALLTHROUGH */
	default:			/* all non-iso endpoints */
		if (!is_out)
			allowed |= URB_SHORT_NOT_OK;
		break;
	case USB_ENDPOINT_XFER_ISOC:
		allowed |= URB_ISO_ASAP;
		break;
	}
	urb->transfer_flags &= allowed;
}

static void stub_recv_cmd_submit(struct stub_device *sdev,
				 struct usbip_header *pdu)
{
	int ret;
	struct stub_priv *priv;
	struct usbip_device *ud = &sdev->ud;
	struct usb_device *udev = sdev->udev;
	int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);

	priv = stub_priv_alloc(sdev, pdu);
	if (!priv)
		return;

	/* setup a urb */
	if (usb_pipeisoc(pipe))
		priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
					  GFP_KERNEL);
	else
		priv->urb = usb_alloc_urb(0, GFP_KERNEL);

	if (!priv->urb) {
		dev_err(&sdev->interface->dev, "malloc urb\n");
		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
		return;
	}

	/* allocate urb transfer buffer, if needed */
	if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
		priv->urb->transfer_buffer =
			kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
				GFP_KERNEL);
		if (!priv->urb->transfer_buffer) {
			usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
			return;
		}
	}

	/* copy urb setup packet */
	priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
					  GFP_KERNEL);
	if (!priv->urb->setup_packet) {
		dev_err(&sdev->interface->dev, "allocate setup_packet\n");
		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
		return;
	}

	/* set other members from the base header of pdu */
	priv->urb->context                = (void *) priv;
	priv->urb->dev                    = udev;
	priv->urb->pipe                   = pipe;
	priv->urb->complete               = stub_complete;

	usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);


	if (usbip_recv_xbuff(ud, priv->urb) < 0)
		return;

	if (usbip_recv_iso(ud, priv->urb) < 0)
		return;

	/* no need to submit an intercepted request, but harmless? */
	tweak_special_requests(priv->urb);

	masking_bogus_flags(priv->urb);
	/* urb is now ready to submit */
	ret = usb_submit_urb(priv->urb, GFP_KERNEL);

	if (ret == 0)
		usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
				  pdu->base.seqnum);
	else {
		dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
		usbip_dump_header(pdu);
		usbip_dump_urb(priv->urb);

		/*
		 * Pessimistic.
		 * This connection will be discarded.
		 */
		usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
	}

	usbip_dbg_stub_rx("Leave\n");
}

/* recv a pdu */
static void stub_rx_pdu(struct usbip_device *ud)
{
	int ret;
	struct usbip_header pdu;
	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
	struct device *dev = &sdev->udev->dev;

	usbip_dbg_stub_rx("Enter\n");

	memset(&pdu, 0, sizeof(pdu));

	/* receive a pdu header */
	ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
	if (ret != sizeof(pdu)) {
		dev_err(dev, "recv a header, %d\n", ret);
		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
		return;
	}

	usbip_header_correct_endian(&pdu, 0);

	if (usbip_dbg_flag_stub_rx)
		usbip_dump_header(&pdu);

	if (!valid_request(sdev, &pdu)) {
		dev_err(dev, "recv invalid request\n");
		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
		return;
	}

	switch (pdu.base.command) {
	case USBIP_CMD_UNLINK:
		stub_recv_cmd_unlink(sdev, &pdu);
		break;

	case USBIP_CMD_SUBMIT:
		stub_recv_cmd_submit(sdev, &pdu);
		break;

	default:
		/* NOTREACHED */
		dev_err(dev, "unknown pdu\n");
		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
		break;
	}
}

int stub_rx_loop(void *data)
{
	struct usbip_device *ud = data;

	while (!kthread_should_stop()) {
		if (usbip_event_happened(ud))
			break;

		stub_rx_pdu(ud);
	}

	return 0;
}