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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 /*
474 * Smatch reported the error case where use_sg is true and buf_len is 0.
475 * In this case, It adds SDEV_EVENT_ERROR_MALLOC and stub_priv will be
476 * released by stub event handler and connection will be shut down.
477 */
478 priv = stub_priv_alloc(sdev, pdu);
479 if (!priv)
480 return;
481
482 buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
483
484 if (use_sg && !buf_len) {
485 dev_err(&udev->dev, "sg buffer with zero length\n");
486 goto err_malloc;
487 }
488
489 /* allocate urb transfer buffer, if needed */
490 if (buf_len) {
491 if (use_sg) {
492 sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
493 if (!sgl)
494 goto err_malloc;
495
496 /* Check if the server's HCD supports SG */
497 if (!udev->bus->sg_tablesize) {
498 /*
499 * If the server's HCD doesn't support SG, break
500 * a single SG request into several URBs and map
501 * each SG list entry to corresponding URB
502 * buffer. The previously allocated SG list is
503 * stored in priv->sgl (If the server's HCD
504 * support SG, SG list is stored only in
505 * urb->sg) and it is used as an indicator that
506 * the server split single SG request into
507 * several URBs. Later, priv->sgl is used by
508 * stub_complete() and stub_send_ret_submit() to
509 * reassemble the divied URBs.
510 */
511 support_sg = 0;
512 num_urbs = nents;
513 priv->completed_urbs = 0;
514 pdu->u.cmd_submit.transfer_flags &=
515 ~URB_DMA_MAP_SG;
516 }
517 } else {
518 buffer = kzalloc(buf_len, GFP_KERNEL);
519 if (!buffer)
520 goto err_malloc;
521 }
522 }
523
524 /* allocate urb array */
525 priv->num_urbs = num_urbs;
526 priv->urbs = kmalloc_array(num_urbs, sizeof(*priv->urbs), GFP_KERNEL);
527 if (!priv->urbs)
528 goto err_urbs;
529
530 /* setup a urb */
531 if (support_sg) {
532 if (usb_pipeisoc(pipe))
533 np = pdu->u.cmd_submit.number_of_packets;
534
535 priv->urbs[0] = usb_alloc_urb(np, GFP_KERNEL);
536 if (!priv->urbs[0])
537 goto err_urb;
538
539 if (buf_len) {
540 if (use_sg) {
541 priv->urbs[0]->sg = sgl;
542 priv->urbs[0]->num_sgs = nents;
543 priv->urbs[0]->transfer_buffer = NULL;
544 } else {
545 priv->urbs[0]->transfer_buffer = buffer;
546 }
547 }
548
549 /* copy urb setup packet */
550 priv->urbs[0]->setup_packet = kmemdup(&pdu->u.cmd_submit.setup,
551 8, GFP_KERNEL);
552 if (!priv->urbs[0]->setup_packet) {
553 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
554 return;
555 }
556
557 usbip_pack_pdu(pdu, priv->urbs[0], USBIP_CMD_SUBMIT, 0);
558 } else {
559 for_each_sg(sgl, sg, nents, i) {
560 priv->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
561 /* The URBs which is previously allocated will be freed
562 * in stub_device_cleanup_urbs() if error occurs.
563 */
564 if (!priv->urbs[i])
565 goto err_urb;
566
567 usbip_pack_pdu(pdu, priv->urbs[i], USBIP_CMD_SUBMIT, 0);
568 priv->urbs[i]->transfer_buffer = sg_virt(sg);
569 priv->urbs[i]->transfer_buffer_length = sg->length;
570 }
571 priv->sgl = sgl;
572 }
573
574 for (i = 0; i < num_urbs; i++) {
575 /* set other members from the base header of pdu */
576 priv->urbs[i]->context = (void *) priv;
577 priv->urbs[i]->dev = udev;
578 priv->urbs[i]->pipe = pipe;
579 priv->urbs[i]->complete = stub_complete;
580
581 /* no need to submit an intercepted request, but harmless? */
582 tweak_special_requests(priv->urbs[i]);
583
584 masking_bogus_flags(priv->urbs[i]);
585 }
586
587 if (stub_recv_xbuff(ud, priv) < 0)
588 return;
589
590 if (usbip_recv_iso(ud, priv->urbs[0]) < 0)
591 return;
592
593 /* urb is now ready to submit */
594 for (i = 0; i < priv->num_urbs; i++) {
595 ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
596
597 if (ret == 0)
598 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
599 pdu->base.seqnum);
600 else {
601 dev_err(&udev->dev, "submit_urb error, %d\n", ret);
602 usbip_dump_header(pdu);
603 usbip_dump_urb(priv->urbs[i]);
604
605 /*
606 * Pessimistic.
607 * This connection will be discarded.
608 */
609 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
610 break;
611 }
612 }
613
614 usbip_dbg_stub_rx("Leave\n");
615 return;
616
617err_urb:
618 kfree(priv->urbs);
619err_urbs:
620 kfree(buffer);
621 sgl_free(sgl);
622err_malloc:
623 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
624}
625
626/* recv a pdu */
627static void stub_rx_pdu(struct usbip_device *ud)
628{
629 int ret;
630 struct usbip_header pdu;
631 struct stub_device *sdev = container_of(ud, struct stub_device, ud);
632 struct device *dev = &sdev->udev->dev;
633
634 usbip_dbg_stub_rx("Enter\n");
635
636 memset(&pdu, 0, sizeof(pdu));
637
638 /* receive a pdu header */
639 ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
640 if (ret != sizeof(pdu)) {
641 dev_err(dev, "recv a header, %d\n", ret);
642 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
643 return;
644 }
645
646 usbip_header_correct_endian(&pdu, 0);
647
648 if (usbip_dbg_flag_stub_rx)
649 usbip_dump_header(&pdu);
650
651 if (!valid_request(sdev, &pdu)) {
652 dev_err(dev, "recv invalid request\n");
653 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
654 return;
655 }
656
657 switch (pdu.base.command) {
658 case USBIP_CMD_UNLINK:
659 stub_recv_cmd_unlink(sdev, &pdu);
660 break;
661
662 case USBIP_CMD_SUBMIT:
663 stub_recv_cmd_submit(sdev, &pdu);
664 break;
665
666 default:
667 /* NOTREACHED */
668 dev_err(dev, "unknown pdu\n");
669 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
670 break;
671 }
672}
673
674int stub_rx_loop(void *data)
675{
676 struct usbip_device *ud = data;
677
678 while (!kthread_should_stop()) {
679 if (usbip_event_happened(ud))
680 break;
681
682 stub_rx_pdu(ud);
683 }
684
685 return 0;
686}