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  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright (C) 2003-2008 Takahiro Hirofuchi
  4 */
  5
  6#include <asm/byteorder.h>
  7#include <linux/kthread.h>
  8#include <linux/usb.h>
  9#include <linux/usb/hcd.h>
 10#include <linux/scatterlist.h>
 11
 12#include "usbip_common.h"
 13#include "stub.h"
 14
 15static int is_clear_halt_cmd(struct urb *urb)
 16{
 17	struct usb_ctrlrequest *req;
 18
 19	req = (struct usb_ctrlrequest *) urb->setup_packet;
 20
 21	return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
 22	       (req->bRequestType == USB_RECIP_ENDPOINT) &&
 23	       (req->wValue == USB_ENDPOINT_HALT);
 24}
 25
 26static int is_set_interface_cmd(struct urb *urb)
 27{
 28	struct usb_ctrlrequest *req;
 29
 30	req = (struct usb_ctrlrequest *) urb->setup_packet;
 31
 32	return (req->bRequest == USB_REQ_SET_INTERFACE) &&
 33		(req->bRequestType == USB_RECIP_INTERFACE);
 34}
 35
 36static int is_set_configuration_cmd(struct urb *urb)
 37{
 38	struct usb_ctrlrequest *req;
 39
 40	req = (struct usb_ctrlrequest *) urb->setup_packet;
 41
 42	return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
 43		(req->bRequestType == USB_RECIP_DEVICE);
 44}
 45
 46static int is_reset_device_cmd(struct urb *urb)
 47{
 48	struct usb_ctrlrequest *req;
 49	__u16 value;
 50	__u16 index;
 51
 52	req = (struct usb_ctrlrequest *) urb->setup_packet;
 53	value = le16_to_cpu(req->wValue);
 54	index = le16_to_cpu(req->wIndex);
 55
 56	if ((req->bRequest == USB_REQ_SET_FEATURE) &&
 57	    (req->bRequestType == USB_RT_PORT) &&
 58	    (value == USB_PORT_FEAT_RESET)) {
 59		usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
 60		return 1;
 61	} else
 62		return 0;
 63}
 64
 65static int tweak_clear_halt_cmd(struct urb *urb)
 66{
 67	struct usb_ctrlrequest *req;
 68	int target_endp;
 69	int target_dir;
 70	int target_pipe;
 71	int ret;
 72
 73	req = (struct usb_ctrlrequest *) urb->setup_packet;
 74
 75	/*
 76	 * The stalled endpoint is specified in the wIndex value. The endpoint
 77	 * of the urb is the target of this clear_halt request (i.e., control
 78	 * endpoint).
 79	 */
 80	target_endp = le16_to_cpu(req->wIndex) & 0x000f;
 81
 82	/* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
 83	target_dir = le16_to_cpu(req->wIndex) & 0x0080;
 84
 85	if (target_dir)
 86		target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
 87	else
 88		target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
 89
 90	ret = usb_clear_halt(urb->dev, target_pipe);
 91	if (ret < 0)
 92		dev_err(&urb->dev->dev,
 93			"usb_clear_halt error: devnum %d endp %d ret %d\n",
 94			urb->dev->devnum, target_endp, ret);
 95	else
 96		dev_info(&urb->dev->dev,
 97			 "usb_clear_halt done: devnum %d endp %d\n",
 98			 urb->dev->devnum, target_endp);
 99
100	return ret;
101}
102
103static int tweak_set_interface_cmd(struct urb *urb)
104{
105	struct usb_ctrlrequest *req;
106	__u16 alternate;
107	__u16 interface;
108	int ret;
109
110	req = (struct usb_ctrlrequest *) urb->setup_packet;
111	alternate = le16_to_cpu(req->wValue);
112	interface = le16_to_cpu(req->wIndex);
113
114	usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
115			  interface, alternate);
116
117	ret = usb_set_interface(urb->dev, interface, alternate);
118	if (ret < 0)
119		dev_err(&urb->dev->dev,
120			"usb_set_interface error: inf %u alt %u ret %d\n",
121			interface, alternate, ret);
122	else
123		dev_info(&urb->dev->dev,
124			"usb_set_interface done: inf %u alt %u\n",
125			interface, alternate);
126
127	return ret;
128}
129
130static int tweak_set_configuration_cmd(struct urb *urb)
131{
132	struct stub_priv *priv = (struct stub_priv *) urb->context;
133	struct stub_device *sdev = priv->sdev;
134	struct usb_ctrlrequest *req;
135	__u16 config;
136	int err;
137
138	req = (struct usb_ctrlrequest *) urb->setup_packet;
139	config = le16_to_cpu(req->wValue);
140
141	err = usb_set_configuration(sdev->udev, config);
142	if (err && err != -ENODEV)
143		dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
144			config, err);
145	return 0;
146}
147
148static int tweak_reset_device_cmd(struct urb *urb)
149{
150	struct stub_priv *priv = (struct stub_priv *) urb->context;
151	struct stub_device *sdev = priv->sdev;
152
153	dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
154
155	if (usb_lock_device_for_reset(sdev->udev, NULL) < 0) {
156		dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
157		return 0;
158	}
159	usb_reset_device(sdev->udev);
160	usb_unlock_device(sdev->udev);
161
162	return 0;
163}
164
165/*
166 * clear_halt, set_interface, and set_configuration require special tricks.
167 */
168static void tweak_special_requests(struct urb *urb)
169{
170	if (!urb || !urb->setup_packet)
171		return;
172
173	if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
174		return;
175
176	if (is_clear_halt_cmd(urb))
177		/* tweak clear_halt */
178		 tweak_clear_halt_cmd(urb);
179
180	else if (is_set_interface_cmd(urb))
181		/* tweak set_interface */
182		tweak_set_interface_cmd(urb);
183
184	else if (is_set_configuration_cmd(urb))
185		/* tweak set_configuration */
186		tweak_set_configuration_cmd(urb);
187
188	else if (is_reset_device_cmd(urb))
189		tweak_reset_device_cmd(urb);
190	else
191		usbip_dbg_stub_rx("no need to tweak\n");
192}
193
194/*
195 * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
196 * By unlinking the urb asynchronously, stub_rx can continuously
197 * process coming urbs.  Even if the urb is unlinked, its completion
198 * handler will be called and stub_tx will send a return pdu.
199 *
200 * See also comments about unlinking strategy in vhci_hcd.c.
201 */
202static int stub_recv_cmd_unlink(struct stub_device *sdev,
203				struct usbip_header *pdu)
204{
205	int ret, i;
206	unsigned long flags;
207	struct stub_priv *priv;
208
209	spin_lock_irqsave(&sdev->priv_lock, flags);
210
211	list_for_each_entry(priv, &sdev->priv_init, list) {
212		if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
213			continue;
214
215		/*
216		 * This matched urb is not completed yet (i.e., be in
217		 * flight in usb hcd hardware/driver). Now we are
218		 * cancelling it. The unlinking flag means that we are
219		 * now not going to return the normal result pdu of a
220		 * submission request, but going to return a result pdu
221		 * of the unlink request.
222		 */
223		priv->unlinking = 1;
224
225		/*
226		 * In the case that unlinking flag is on, prev->seqnum
227		 * is changed from the seqnum of the cancelling urb to
228		 * the seqnum of the unlink request. This will be used
229		 * to make the result pdu of the unlink request.
230		 */
231		priv->seqnum = pdu->base.seqnum;
232
233		spin_unlock_irqrestore(&sdev->priv_lock, flags);
234
235		/*
236		 * usb_unlink_urb() is now out of spinlocking to avoid
237		 * spinlock recursion since stub_complete() is
238		 * sometimes called in this context but not in the
239		 * interrupt context.  If stub_complete() is executed
240		 * before we call usb_unlink_urb(), usb_unlink_urb()
241		 * will return an error value. In this case, stub_tx
242		 * will return the result pdu of this unlink request
243		 * though submission is completed and actual unlinking
244		 * is not executed. OK?
245		 */
246		/* In the above case, urb->status is not -ECONNRESET,
247		 * so a driver in a client host will know the failure
248		 * of the unlink request ?
249		 */
250		for (i = priv->completed_urbs; i < priv->num_urbs; i++) {
251			ret = usb_unlink_urb(priv->urbs[i]);
252			if (ret != -EINPROGRESS)
253				dev_err(&priv->urbs[i]->dev->dev,
254					"failed to unlink %d/%d urb of seqnum %lu, ret %d\n",
255					i + 1, priv->num_urbs,
256					priv->seqnum, ret);
257		}
258		return 0;
259	}
260
261	usbip_dbg_stub_rx("seqnum %d is not pending\n",
262			  pdu->u.cmd_unlink.seqnum);
263
264	/*
265	 * The urb of the unlink target is not found in priv_init queue. It was
266	 * already completed and its results is/was going to be sent by a
267	 * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
268	 * return the completeness of this unlink request to vhci_hcd.
269	 */
270	stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
271
272	spin_unlock_irqrestore(&sdev->priv_lock, flags);
273
274	return 0;
275}
276
277static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
278{
279	struct usbip_device *ud = &sdev->ud;
280	int valid = 0;
281
282	if (pdu->base.devid == sdev->devid) {
283		spin_lock_irq(&ud->lock);
284		if (ud->status == SDEV_ST_USED) {
285			/* A request is valid. */
286			valid = 1;
287		}
288		spin_unlock_irq(&ud->lock);
289	}
290
291	return valid;
292}
293
294static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
295					 struct usbip_header *pdu)
296{
297	struct stub_priv *priv;
298	struct usbip_device *ud = &sdev->ud;
299	unsigned long flags;
300
301	spin_lock_irqsave(&sdev->priv_lock, flags);
302
303	priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
304	if (!priv) {
305		dev_err(&sdev->udev->dev, "alloc stub_priv\n");
306		spin_unlock_irqrestore(&sdev->priv_lock, flags);
307		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
308		return NULL;
309	}
310
311	priv->seqnum = pdu->base.seqnum;
312	priv->sdev = sdev;
313
314	/*
315	 * After a stub_priv is linked to a list_head,
316	 * our error handler can free allocated data.
317	 */
318	list_add_tail(&priv->list, &sdev->priv_init);
319
320	spin_unlock_irqrestore(&sdev->priv_lock, flags);
321
322	return priv;
323}
324
325static int get_pipe(struct stub_device *sdev, struct usbip_header *pdu)
326{
327	struct usb_device *udev = sdev->udev;
328	struct usb_host_endpoint *ep;
329	struct usb_endpoint_descriptor *epd = NULL;
330	int epnum = pdu->base.ep;
331	int dir = pdu->base.direction;
332
333	if (epnum < 0 || epnum > 15)
334		goto err_ret;
335
336	if (dir == USBIP_DIR_IN)
337		ep = udev->ep_in[epnum & 0x7f];
338	else
339		ep = udev->ep_out[epnum & 0x7f];
340	if (!ep)
341		goto err_ret;
342
343	epd = &ep->desc;
344
345	if (usb_endpoint_xfer_control(epd)) {
346		if (dir == USBIP_DIR_OUT)
347			return usb_sndctrlpipe(udev, epnum);
348		else
349			return usb_rcvctrlpipe(udev, epnum);
350	}
351
352	if (usb_endpoint_xfer_bulk(epd)) {
353		if (dir == USBIP_DIR_OUT)
354			return usb_sndbulkpipe(udev, epnum);
355		else
356			return usb_rcvbulkpipe(udev, epnum);
357	}
358
359	if (usb_endpoint_xfer_int(epd)) {
360		if (dir == USBIP_DIR_OUT)
361			return usb_sndintpipe(udev, epnum);
362		else
363			return usb_rcvintpipe(udev, epnum);
364	}
365
366	if (usb_endpoint_xfer_isoc(epd)) {
367		/* validate number of packets */
368		if (pdu->u.cmd_submit.number_of_packets < 0 ||
369		    pdu->u.cmd_submit.number_of_packets >
370		    USBIP_MAX_ISO_PACKETS) {
371			dev_err(&sdev->udev->dev,
372				"CMD_SUBMIT: isoc invalid num packets %d\n",
373				pdu->u.cmd_submit.number_of_packets);
374			return -1;
375		}
376		if (dir == USBIP_DIR_OUT)
377			return usb_sndisocpipe(udev, epnum);
378		else
379			return usb_rcvisocpipe(udev, epnum);
380	}
381
382err_ret:
383	/* NOT REACHED */
384	dev_err(&sdev->udev->dev, "CMD_SUBMIT: invalid epnum %d\n", epnum);
385	return -1;
386}
387
388static void masking_bogus_flags(struct urb *urb)
389{
390	int				xfertype;
391	struct usb_device		*dev;
392	struct usb_host_endpoint	*ep;
393	int				is_out;
394	unsigned int	allowed;
395
396	if (!urb || urb->hcpriv || !urb->complete)
397		return;
398	dev = urb->dev;
399	if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
400		return;
401
402	ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
403		[usb_pipeendpoint(urb->pipe)];
404	if (!ep)
405		return;
406
407	xfertype = usb_endpoint_type(&ep->desc);
408	if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
409		struct usb_ctrlrequest *setup =
410			(struct usb_ctrlrequest *) urb->setup_packet;
411
412		if (!setup)
413			return;
414		is_out = !(setup->bRequestType & USB_DIR_IN) ||
415			!setup->wLength;
416	} else {
417		is_out = usb_endpoint_dir_out(&ep->desc);
418	}
419
420	/* enforce simple/standard policy */
421	allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
422		   URB_DIR_MASK | URB_FREE_BUFFER);
423	switch (xfertype) {
424	case USB_ENDPOINT_XFER_BULK:
425		if (is_out)
426			allowed |= URB_ZERO_PACKET;
427		/* FALLTHROUGH */
428	default:			/* all non-iso endpoints */
429		if (!is_out)
430			allowed |= URB_SHORT_NOT_OK;
431		break;
432	case USB_ENDPOINT_XFER_ISOC:
433		allowed |= URB_ISO_ASAP;
434		break;
435	}
436	urb->transfer_flags &= allowed;
437}
438
439static int stub_recv_xbuff(struct usbip_device *ud, struct stub_priv *priv)
440{
441	int ret;
442	int i;
443
444	for (i = 0; i < priv->num_urbs; i++) {
445		ret = usbip_recv_xbuff(ud, priv->urbs[i]);
446		if (ret < 0)
447			break;
448	}
449
450	return ret;
451}
452
453static void stub_recv_cmd_submit(struct stub_device *sdev,
454				 struct usbip_header *pdu)
455{
456	struct stub_priv *priv;
457	struct usbip_device *ud = &sdev->ud;
458	struct usb_device *udev = sdev->udev;
459	struct scatterlist *sgl = NULL, *sg;
460	void *buffer = NULL;
461	unsigned long long buf_len;
462	int nents;
463	int num_urbs = 1;
464	int pipe = get_pipe(sdev, pdu);
465	int use_sg = pdu->u.cmd_submit.transfer_flags & URB_DMA_MAP_SG;
466	int support_sg = 1;
467	int np = 0;
468	int ret, i;
469
470	if (pipe == -1)
471		return;
472
473	priv = stub_priv_alloc(sdev, pdu);
474	if (!priv)
475		return;
476
477	buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
478
479	/* allocate urb transfer buffer, if needed */
480	if (buf_len) {
481		if (use_sg) {
482			sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
483			if (!sgl)
484				goto err_malloc;
485		} else {
486			buffer = kzalloc(buf_len, GFP_KERNEL);
487			if (!buffer)
488				goto err_malloc;
489		}
490	}
491
492	/* Check if the server's HCD supports SG */
493	if (use_sg && !udev->bus->sg_tablesize) {
494		/*
495		 * If the server's HCD doesn't support SG, break a single SG
496		 * request into several URBs and map each SG list entry to
497		 * corresponding URB buffer. The previously allocated SG
498		 * list is stored in priv->sgl (If the server's HCD support SG,
499		 * SG list is stored only in urb->sg) and it is used as an
500		 * indicator that the server split single SG request into
501		 * several URBs. Later, priv->sgl is used by stub_complete() and
502		 * stub_send_ret_submit() to reassemble the divied URBs.
503		 */
504		support_sg = 0;
505		num_urbs = nents;
506		priv->completed_urbs = 0;
507		pdu->u.cmd_submit.transfer_flags &= ~URB_DMA_MAP_SG;
508	}
509
510	/* allocate urb array */
511	priv->num_urbs = num_urbs;
512	priv->urbs = kmalloc_array(num_urbs, sizeof(*priv->urbs), GFP_KERNEL);
513	if (!priv->urbs)
514		goto err_urbs;
515
516	/* setup a urb */
517	if (support_sg) {
518		if (usb_pipeisoc(pipe))
519			np = pdu->u.cmd_submit.number_of_packets;
520
521		priv->urbs[0] = usb_alloc_urb(np, GFP_KERNEL);
522		if (!priv->urbs[0])
523			goto err_urb;
524
525		if (buf_len) {
526			if (use_sg) {
527				priv->urbs[0]->sg = sgl;
528				priv->urbs[0]->num_sgs = nents;
529				priv->urbs[0]->transfer_buffer = NULL;
530			} else {
531				priv->urbs[0]->transfer_buffer = buffer;
532			}
533		}
534
535		/* copy urb setup packet */
536		priv->urbs[0]->setup_packet = kmemdup(&pdu->u.cmd_submit.setup,
537					8, GFP_KERNEL);
538		if (!priv->urbs[0]->setup_packet) {
539			usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
540			return;
541		}
542
543		usbip_pack_pdu(pdu, priv->urbs[0], USBIP_CMD_SUBMIT, 0);
544	} else {
545		for_each_sg(sgl, sg, nents, i) {
546			priv->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
547			/* The URBs which is previously allocated will be freed
548			 * in stub_device_cleanup_urbs() if error occurs.
549			 */
550			if (!priv->urbs[i])
551				goto err_urb;
552
553			usbip_pack_pdu(pdu, priv->urbs[i], USBIP_CMD_SUBMIT, 0);
554			priv->urbs[i]->transfer_buffer = sg_virt(sg);
555			priv->urbs[i]->transfer_buffer_length = sg->length;
556		}
557		priv->sgl = sgl;
558	}
559
560	for (i = 0; i < num_urbs; i++) {
561		/* set other members from the base header of pdu */
562		priv->urbs[i]->context = (void *) priv;
563		priv->urbs[i]->dev = udev;
564		priv->urbs[i]->pipe = pipe;
565		priv->urbs[i]->complete = stub_complete;
566
567		/* no need to submit an intercepted request, but harmless? */
568		tweak_special_requests(priv->urbs[i]);
569
570		masking_bogus_flags(priv->urbs[i]);
571	}
572
573	if (stub_recv_xbuff(ud, priv) < 0)
574		return;
575
576	if (usbip_recv_iso(ud, priv->urbs[0]) < 0)
577		return;
578
579	/* urb is now ready to submit */
580	for (i = 0; i < priv->num_urbs; i++) {
581		ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
582
583		if (ret == 0)
584			usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
585					pdu->base.seqnum);
586		else {
587			dev_err(&udev->dev, "submit_urb error, %d\n", ret);
588			usbip_dump_header(pdu);
589			usbip_dump_urb(priv->urbs[i]);
590
591			/*
592			 * Pessimistic.
593			 * This connection will be discarded.
594			 */
595			usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
596			break;
597		}
598	}
599
600	usbip_dbg_stub_rx("Leave\n");
601	return;
602
603err_urb:
604	kfree(priv->urbs);
605err_urbs:
606	kfree(buffer);
607	sgl_free(sgl);
608err_malloc:
609	usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
610}
611
612/* recv a pdu */
613static void stub_rx_pdu(struct usbip_device *ud)
614{
615	int ret;
616	struct usbip_header pdu;
617	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
618	struct device *dev = &sdev->udev->dev;
619
620	usbip_dbg_stub_rx("Enter\n");
621
622	memset(&pdu, 0, sizeof(pdu));
623
624	/* receive a pdu header */
625	ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
626	if (ret != sizeof(pdu)) {
627		dev_err(dev, "recv a header, %d\n", ret);
628		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
629		return;
630	}
631
632	usbip_header_correct_endian(&pdu, 0);
633
634	if (usbip_dbg_flag_stub_rx)
635		usbip_dump_header(&pdu);
636
637	if (!valid_request(sdev, &pdu)) {
638		dev_err(dev, "recv invalid request\n");
639		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
640		return;
641	}
642
643	switch (pdu.base.command) {
644	case USBIP_CMD_UNLINK:
645		stub_recv_cmd_unlink(sdev, &pdu);
646		break;
647
648	case USBIP_CMD_SUBMIT:
649		stub_recv_cmd_submit(sdev, &pdu);
650		break;
651
652	default:
653		/* NOTREACHED */
654		dev_err(dev, "unknown pdu\n");
655		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
656		break;
657	}
658}
659
660int stub_rx_loop(void *data)
661{
662	struct usbip_device *ud = data;
663
664	while (!kthread_should_stop()) {
665		if (usbip_event_happened(ud))
666			break;
667
668		stub_rx_pdu(ud);
669	}
670
671	return 0;
672}