1/*
2 * Copyright (C) 2003-2008 Takahiro Hirofuchi
3 *
4 * This is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This 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
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
17 * USA.
18 */
19
20#include <asm/byteorder.h>
21#include <linux/kthread.h>
22#include <linux/usb.h>
23#include <linux/usb/hcd.h>
24
25#include "usbip_common.h"
26#include "stub.h"
27
28static int is_clear_halt_cmd(struct urb *urb)
29{
30	struct usb_ctrlrequest *req;
31
32	req = (struct usb_ctrlrequest *) urb->setup_packet;
33
34	 return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
35		 (req->bRequestType == USB_RECIP_ENDPOINT) &&
36		 (req->wValue == USB_ENDPOINT_HALT);
37}
38
39static int is_set_interface_cmd(struct urb *urb)
40{
41	struct usb_ctrlrequest *req;
42
43	req = (struct usb_ctrlrequest *) urb->setup_packet;
44
45	return (req->bRequest == USB_REQ_SET_INTERFACE) &&
46		(req->bRequestType == USB_RECIP_INTERFACE);
47}
48
49static int is_set_configuration_cmd(struct urb *urb)
50{
51	struct usb_ctrlrequest *req;
52
53	req = (struct usb_ctrlrequest *) urb->setup_packet;
54
55	return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
56		(req->bRequestType == USB_RECIP_DEVICE);
57}
58
59static int is_reset_device_cmd(struct urb *urb)
60{
61	struct usb_ctrlrequest *req;
62	__u16 value;
63	__u16 index;
64
65	req = (struct usb_ctrlrequest *) urb->setup_packet;
66	value = le16_to_cpu(req->wValue);
67	index = le16_to_cpu(req->wIndex);
68
69	if ((req->bRequest == USB_REQ_SET_FEATURE) &&
70	    (req->bRequestType == USB_RT_PORT) &&
71	    (value == USB_PORT_FEAT_RESET)) {
72		usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
73		return 1;
74	} else
75		return 0;
76}
77
78static int tweak_clear_halt_cmd(struct urb *urb)
79{
80	struct usb_ctrlrequest *req;
81	int target_endp;
82	int target_dir;
83	int target_pipe;
84	int ret;
85
86	req = (struct usb_ctrlrequest *) urb->setup_packet;
87
88	/*
89	 * The stalled endpoint is specified in the wIndex value. The endpoint
90	 * of the urb is the target of this clear_halt request (i.e., control
91	 * endpoint).
92	 */
93	target_endp = le16_to_cpu(req->wIndex) & 0x000f;
94
95	/* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
96	target_dir = le16_to_cpu(req->wIndex) & 0x0080;
97
98	if (target_dir)
99		target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
100	else
101		target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
102
103	ret = usb_clear_halt(urb->dev, target_pipe);
104	if (ret < 0)
105		dev_err(&urb->dev->dev,
106			"usb_clear_halt error: devnum %d endp %d ret %d\n",
107			urb->dev->devnum, target_endp, ret);
108	else
109		dev_info(&urb->dev->dev,
110			 "usb_clear_halt done: devnum %d endp %d\n",
111			 urb->dev->devnum, target_endp);
112
113	return ret;
114}
115
116static int tweak_set_interface_cmd(struct urb *urb)
117{
118	struct usb_ctrlrequest *req;
119	__u16 alternate;
120	__u16 interface;
121	int ret;
122
123	req = (struct usb_ctrlrequest *) urb->setup_packet;
124	alternate = le16_to_cpu(req->wValue);
125	interface = le16_to_cpu(req->wIndex);
126
127	usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
128			  interface, alternate);
129
130	ret = usb_set_interface(urb->dev, interface, alternate);
131	if (ret < 0)
132		dev_err(&urb->dev->dev,
133			"usb_set_interface error: inf %u alt %u ret %d\n",
134			interface, alternate, ret);
135	else
136		dev_info(&urb->dev->dev,
137			"usb_set_interface done: inf %u alt %u\n",
138			interface, alternate);
139
140	return ret;
141}
142
143static int tweak_set_configuration_cmd(struct urb *urb)
144{
145	struct stub_priv *priv = (struct stub_priv *) urb->context;
146	struct stub_device *sdev = priv->sdev;
147	struct usb_ctrlrequest *req;
148	__u16 config;
149	int err;
150
151	req = (struct usb_ctrlrequest *) urb->setup_packet;
152	config = le16_to_cpu(req->wValue);
153
154	err = usb_set_configuration(sdev->udev, config);
155	if (err && err != -ENODEV)
156		dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
157			config, err);
158	return 0;
159}
160
161static int tweak_reset_device_cmd(struct urb *urb)
162{
163	struct stub_priv *priv = (struct stub_priv *) urb->context;
164	struct stub_device *sdev = priv->sdev;
165
166	dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
167
168	/*
169	 * With the implementation of pre_reset and post_reset the driver no
170	 * longer unbinds. This allows the use of synchronous reset.
171	 */
172
173	if (usb_lock_device_for_reset(sdev->udev, sdev->interface) < 0) {
174		dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
175		return 0;
176	}
177	usb_reset_device(sdev->udev);
178	usb_unlock_device(sdev->udev);
179
180	return 0;
181}
182
183/*
184 * clear_halt, set_interface, and set_configuration require special tricks.
185 */
186static void tweak_special_requests(struct urb *urb)
187{
188	if (!urb || !urb->setup_packet)
189		return;
190
191	if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
192		return;
193
194	if (is_clear_halt_cmd(urb))
195		/* tweak clear_halt */
196		 tweak_clear_halt_cmd(urb);
197
198	else if (is_set_interface_cmd(urb))
199		/* tweak set_interface */
200		tweak_set_interface_cmd(urb);
201
202	else if (is_set_configuration_cmd(urb))
203		/* tweak set_configuration */
204		tweak_set_configuration_cmd(urb);
205
206	else if (is_reset_device_cmd(urb))
207		tweak_reset_device_cmd(urb);
208	else
209		usbip_dbg_stub_rx("no need to tweak\n");
210}
211
212/*
213 * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
214 * By unlinking the urb asynchronously, stub_rx can continuously
215 * process coming urbs.  Even if the urb is unlinked, its completion
216 * handler will be called and stub_tx will send a return pdu.
217 *
218 * See also comments about unlinking strategy in vhci_hcd.c.
219 */
220static int stub_recv_cmd_unlink(struct stub_device *sdev,
221				struct usbip_header *pdu)
222{
223	int ret;
224	unsigned long flags;
225	struct stub_priv *priv;
226
227	spin_lock_irqsave(&sdev->priv_lock, flags);
228
229	list_for_each_entry(priv, &sdev->priv_init, list) {
230		if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
231			continue;
232
233		dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
234			 priv->urb);
235
236		/*
237		 * This matched urb is not completed yet (i.e., be in
238		 * flight in usb hcd hardware/driver). Now we are
239		 * cancelling it. The unlinking flag means that we are
240		 * now not going to return the normal result pdu of a
241		 * submission request, but going to return a result pdu
242		 * of the unlink request.
243		 */
244		priv->unlinking = 1;
245
246		/*
247		 * In the case that unlinking flag is on, prev->seqnum
248		 * is changed from the seqnum of the cancelling urb to
249		 * the seqnum of the unlink request. This will be used
250		 * to make the result pdu of the unlink request.
251		 */
252		priv->seqnum = pdu->base.seqnum;
253
254		spin_unlock_irqrestore(&sdev->priv_lock, flags);
255
256		/*
257		 * usb_unlink_urb() is now out of spinlocking to avoid
258		 * spinlock recursion since stub_complete() is
259		 * sometimes called in this context but not in the
260		 * interrupt context.  If stub_complete() is executed
261		 * before we call usb_unlink_urb(), usb_unlink_urb()
262		 * will return an error value. In this case, stub_tx
263		 * will return the result pdu of this unlink request
264		 * though submission is completed and actual unlinking
265		 * is not executed. OK?
266		 */
267		/* In the above case, urb->status is not -ECONNRESET,
268		 * so a driver in a client host will know the failure
269		 * of the unlink request ?
270		 */
271		ret = usb_unlink_urb(priv->urb);
272		if (ret != -EINPROGRESS)
273			dev_err(&priv->urb->dev->dev,
274				"failed to unlink a urb %p, ret %d\n",
275				priv->urb, ret);
276
277		return 0;
278	}
279
280	usbip_dbg_stub_rx("seqnum %d is not pending\n",
281			  pdu->u.cmd_unlink.seqnum);
282
283	/*
284	 * The urb of the unlink target is not found in priv_init queue. It was
285	 * already completed and its results is/was going to be sent by a
286	 * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
287	 * return the completeness of this unlink request to vhci_hcd.
288	 */
289	stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
290
291	spin_unlock_irqrestore(&sdev->priv_lock, flags);
292
293	return 0;
294}
295
296static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
297{
298	struct usbip_device *ud = &sdev->ud;
299	int valid = 0;
300
301	if (pdu->base.devid == sdev->devid) {
302		spin_lock_irq(&ud->lock);
303		if (ud->status == SDEV_ST_USED) {
304			/* A request is valid. */
305			valid = 1;
306		}
307		spin_unlock_irq(&ud->lock);
308	}
309
310	return valid;
311}
312
313static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
314					 struct usbip_header *pdu)
315{
316	struct stub_priv *priv;
317	struct usbip_device *ud = &sdev->ud;
318	unsigned long flags;
319
320	spin_lock_irqsave(&sdev->priv_lock, flags);
321
322	priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
323	if (!priv) {
324		dev_err(&sdev->interface->dev, "alloc stub_priv\n");
325		spin_unlock_irqrestore(&sdev->priv_lock, flags);
326		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
327		return NULL;
328	}
329
330	priv->seqnum = pdu->base.seqnum;
331	priv->sdev = sdev;
332
333	/*
334	 * After a stub_priv is linked to a list_head,
335	 * our error handler can free allocated data.
336	 */
337	list_add_tail(&priv->list, &sdev->priv_init);
338
339	spin_unlock_irqrestore(&sdev->priv_lock, flags);
340
341	return priv;
342}
343
344static int get_pipe(struct stub_device *sdev, int epnum, int dir)
345{
346	struct usb_device *udev = sdev->udev;
347	struct usb_host_endpoint *ep;
348	struct usb_endpoint_descriptor *epd = NULL;
349
350	if (dir == USBIP_DIR_IN)
351		ep = udev->ep_in[epnum & 0x7f];
352	else
353		ep = udev->ep_out[epnum & 0x7f];
354	if (!ep) {
355		dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
356			epnum);
357		BUG();
358	}
359
360	epd = &ep->desc;
361	if (usb_endpoint_xfer_control(epd)) {
362		if (dir == USBIP_DIR_OUT)
363			return usb_sndctrlpipe(udev, epnum);
364		else
365			return usb_rcvctrlpipe(udev, epnum);
366	}
367
368	if (usb_endpoint_xfer_bulk(epd)) {
369		if (dir == USBIP_DIR_OUT)
370			return usb_sndbulkpipe(udev, epnum);
371		else
372			return usb_rcvbulkpipe(udev, epnum);
373	}
374
375	if (usb_endpoint_xfer_int(epd)) {
376		if (dir == USBIP_DIR_OUT)
377			return usb_sndintpipe(udev, epnum);
378		else
379			return usb_rcvintpipe(udev, epnum);
380	}
381
382	if (usb_endpoint_xfer_isoc(epd)) {
383		if (dir == USBIP_DIR_OUT)
384			return usb_sndisocpipe(udev, epnum);
385		else
386			return usb_rcvisocpipe(udev, epnum);
387	}
388
389	/* NOT REACHED */
390	dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
391	return 0;
392}
393
394static void masking_bogus_flags(struct urb *urb)
395{
396	int				xfertype;
397	struct usb_device		*dev;
398	struct usb_host_endpoint	*ep;
399	int				is_out;
400	unsigned int	allowed;
401
402	if (!urb || urb->hcpriv || !urb->complete)
403		return;
404	dev = urb->dev;
405	if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
406		return;
407
408	ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
409		[usb_pipeendpoint(urb->pipe)];
410	if (!ep)
411		return;
412
413	xfertype = usb_endpoint_type(&ep->desc);
414	if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
415		struct usb_ctrlrequest *setup =
416			(struct usb_ctrlrequest *) urb->setup_packet;
417
418		if (!setup)
419			return;
420		is_out = !(setup->bRequestType & USB_DIR_IN) ||
421			!setup->wLength;
422	} else {
423		is_out = usb_endpoint_dir_out(&ep->desc);
424	}
425
426	/* enforce simple/standard policy */
427	allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
428		   URB_DIR_MASK | URB_FREE_BUFFER);
429	switch (xfertype) {
430	case USB_ENDPOINT_XFER_BULK:
431		if (is_out)
432			allowed |= URB_ZERO_PACKET;
433		/* FALLTHROUGH */
434	case USB_ENDPOINT_XFER_CONTROL:
435		allowed |= URB_NO_FSBR;	/* only affects UHCI */
436		/* FALLTHROUGH */
437	default:			/* all non-iso endpoints */
438		if (!is_out)
439			allowed |= URB_SHORT_NOT_OK;
440		break;
441	case USB_ENDPOINT_XFER_ISOC:
442		allowed |= URB_ISO_ASAP;
443		break;
444	}
445	urb->transfer_flags &= allowed;
446}
447
448static void stub_recv_cmd_submit(struct stub_device *sdev,
449				 struct usbip_header *pdu)
450{
451	int ret;
452	struct stub_priv *priv;
453	struct usbip_device *ud = &sdev->ud;
454	struct usb_device *udev = sdev->udev;
455	int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
456
457	priv = stub_priv_alloc(sdev, pdu);
458	if (!priv)
459		return;
460
461	/* setup a urb */
462	if (usb_pipeisoc(pipe))
463		priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
464					  GFP_KERNEL);
465	else
466		priv->urb = usb_alloc_urb(0, GFP_KERNEL);
467
468	if (!priv->urb) {
469		dev_err(&sdev->interface->dev, "malloc urb\n");
470		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
471		return;
472	}
473
474	/* allocate urb transfer buffer, if needed */
475	if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
476		priv->urb->transfer_buffer =
477			kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
478				GFP_KERNEL);
479		if (!priv->urb->transfer_buffer) {
480			usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
481			return;
482		}
483	}
484
485	/* copy urb setup packet */
486	priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
487					  GFP_KERNEL);
488	if (!priv->urb->setup_packet) {
489		dev_err(&sdev->interface->dev, "allocate setup_packet\n");
490		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
491		return;
492	}
493
494	/* set other members from the base header of pdu */
495	priv->urb->context                = (void *) priv;
496	priv->urb->dev                    = udev;
497	priv->urb->pipe                   = pipe;
498	priv->urb->complete               = stub_complete;
499
500	usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
501
502
503	if (usbip_recv_xbuff(ud, priv->urb) < 0)
504		return;
505
506	if (usbip_recv_iso(ud, priv->urb) < 0)
507		return;
508
509	/* no need to submit an intercepted request, but harmless? */
510	tweak_special_requests(priv->urb);
511
512	masking_bogus_flags(priv->urb);
513	/* urb is now ready to submit */
514	ret = usb_submit_urb(priv->urb, GFP_KERNEL);
515
516	if (ret == 0)
517		usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
518				  pdu->base.seqnum);
519	else {
520		dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
521		usbip_dump_header(pdu);
522		usbip_dump_urb(priv->urb);
523
524		/*
525		 * Pessimistic.
526		 * This connection will be discarded.
527		 */
528		usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
529	}
530
531	usbip_dbg_stub_rx("Leave\n");
532}
533
534/* recv a pdu */
535static void stub_rx_pdu(struct usbip_device *ud)
536{
537	int ret;
538	struct usbip_header pdu;
539	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
540	struct device *dev = &sdev->udev->dev;
541
542	usbip_dbg_stub_rx("Enter\n");
543
544	memset(&pdu, 0, sizeof(pdu));
545
546	/* receive a pdu header */
547	ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
548	if (ret != sizeof(pdu)) {
549		dev_err(dev, "recv a header, %d\n", ret);
550		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
551		return;
552	}
553
554	usbip_header_correct_endian(&pdu, 0);
555
556	if (usbip_dbg_flag_stub_rx)
557		usbip_dump_header(&pdu);
558
559	if (!valid_request(sdev, &pdu)) {
560		dev_err(dev, "recv invalid request\n");
561		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
562		return;
563	}
564
565	switch (pdu.base.command) {
566	case USBIP_CMD_UNLINK:
567		stub_recv_cmd_unlink(sdev, &pdu);
568		break;
569
570	case USBIP_CMD_SUBMIT:
571		stub_recv_cmd_submit(sdev, &pdu);
572		break;
573
574	default:
575		/* NOTREACHED */
576		dev_err(dev, "unknown pdu\n");
577		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
578		break;
579	}
580}
581
582int stub_rx_loop(void *data)
583{
584	struct usbip_device *ud = data;
585
586	while (!kthread_should_stop()) {
587		if (usbip_event_happened(ud))
588			break;
589
590		stub_rx_pdu(ud);
591	}
592
593	return 0;
594}
595