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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 usb_lock_device(sdev->udev);
142 err = usb_set_configuration(sdev->udev, config);
143 usb_unlock_device(sdev->udev);
144 if (err && err != -ENODEV)
145 dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
146 config, err);
147 return err;
148}
149
150static int tweak_reset_device_cmd(struct urb *urb)
151{
152 struct stub_priv *priv = (struct stub_priv *) urb->context;
153 struct stub_device *sdev = priv->sdev;
154 int err;
155
156 dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
157
158 err = usb_lock_device_for_reset(sdev->udev, NULL);
159 if (err < 0) {
160 dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
161 return err;
162 }
163 err = usb_reset_device(sdev->udev);
164 usb_unlock_device(sdev->udev);
165
166 return err;
167}
168
169/*
170 * clear_halt, set_interface, and set_configuration require special tricks.
171 * Returns 1 if request was tweaked, 0 otherwise.
172 */
173static int tweak_special_requests(struct urb *urb)
174{
175 int err;
176
177 if (!urb || !urb->setup_packet)
178 return 0;
179
180 if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
181 return 0;
182
183 if (is_clear_halt_cmd(urb))
184 /* tweak clear_halt */
185 err = tweak_clear_halt_cmd(urb);
186
187 else if (is_set_interface_cmd(urb))
188 /* tweak set_interface */
189 err = tweak_set_interface_cmd(urb);
190
191 else if (is_set_configuration_cmd(urb))
192 /* tweak set_configuration */
193 err = tweak_set_configuration_cmd(urb);
194
195 else if (is_reset_device_cmd(urb))
196 err = tweak_reset_device_cmd(urb);
197 else {
198 usbip_dbg_stub_rx("no need to tweak\n");
199 return 0;
200 }
201
202 return !err;
203}
204
205/*
206 * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
207 * By unlinking the urb asynchronously, stub_rx can continuously
208 * process coming urbs. Even if the urb is unlinked, its completion
209 * handler will be called and stub_tx will send a return pdu.
210 *
211 * See also comments about unlinking strategy in vhci_hcd.c.
212 */
213static int stub_recv_cmd_unlink(struct stub_device *sdev,
214 struct usbip_header *pdu)
215{
216 int ret, i;
217 unsigned long flags;
218 struct stub_priv *priv;
219
220 spin_lock_irqsave(&sdev->priv_lock, flags);
221
222 list_for_each_entry(priv, &sdev->priv_init, list) {
223 if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
224 continue;
225
226 /*
227 * This matched urb is not completed yet (i.e., be in
228 * flight in usb hcd hardware/driver). Now we are
229 * cancelling it. The unlinking flag means that we are
230 * now not going to return the normal result pdu of a
231 * submission request, but going to return a result pdu
232 * of the unlink request.
233 */
234 priv->unlinking = 1;
235
236 /*
237 * In the case that unlinking flag is on, prev->seqnum
238 * is changed from the seqnum of the cancelling urb to
239 * the seqnum of the unlink request. This will be used
240 * to make the result pdu of the unlink request.
241 */
242 priv->seqnum = pdu->base.seqnum;
243
244 spin_unlock_irqrestore(&sdev->priv_lock, flags);
245
246 /*
247 * usb_unlink_urb() is now out of spinlocking to avoid
248 * spinlock recursion since stub_complete() is
249 * sometimes called in this context but not in the
250 * interrupt context. If stub_complete() is executed
251 * before we call usb_unlink_urb(), usb_unlink_urb()
252 * will return an error value. In this case, stub_tx
253 * will return the result pdu of this unlink request
254 * though submission is completed and actual unlinking
255 * is not executed. OK?
256 */
257 /* In the above case, urb->status is not -ECONNRESET,
258 * so a driver in a client host will know the failure
259 * of the unlink request ?
260 */
261 for (i = priv->completed_urbs; i < priv->num_urbs; i++) {
262 ret = usb_unlink_urb(priv->urbs[i]);
263 if (ret != -EINPROGRESS)
264 dev_err(&priv->urbs[i]->dev->dev,
265 "failed to unlink %d/%d urb of seqnum %lu, ret %d\n",
266 i + 1, priv->num_urbs,
267 priv->seqnum, ret);
268 }
269 return 0;
270 }
271
272 usbip_dbg_stub_rx("seqnum %d is not pending\n",
273 pdu->u.cmd_unlink.seqnum);
274
275 /*
276 * The urb of the unlink target is not found in priv_init queue. It was
277 * already completed and its results is/was going to be sent by a
278 * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
279 * return the completeness of this unlink request to vhci_hcd.
280 */
281 stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
282
283 spin_unlock_irqrestore(&sdev->priv_lock, flags);
284
285 return 0;
286}
287
288static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
289{
290 struct usbip_device *ud = &sdev->ud;
291 int valid = 0;
292
293 if (pdu->base.devid == sdev->devid) {
294 spin_lock_irq(&ud->lock);
295 if (ud->status == SDEV_ST_USED) {
296 /* A request is valid. */
297 valid = 1;
298 }
299 spin_unlock_irq(&ud->lock);
300 }
301
302 return valid;
303}
304
305static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
306 struct usbip_header *pdu)
307{
308 struct stub_priv *priv;
309 struct usbip_device *ud = &sdev->ud;
310 unsigned long flags;
311
312 spin_lock_irqsave(&sdev->priv_lock, flags);
313
314 priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
315 if (!priv) {
316 dev_err(&sdev->udev->dev, "alloc stub_priv\n");
317 spin_unlock_irqrestore(&sdev->priv_lock, flags);
318 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
319 return NULL;
320 }
321
322 priv->seqnum = pdu->base.seqnum;
323 priv->sdev = sdev;
324
325 /*
326 * After a stub_priv is linked to a list_head,
327 * our error handler can free allocated data.
328 */
329 list_add_tail(&priv->list, &sdev->priv_init);
330
331 spin_unlock_irqrestore(&sdev->priv_lock, flags);
332
333 return priv;
334}
335
336static int get_pipe(struct stub_device *sdev, struct usbip_header *pdu)
337{
338 struct usb_device *udev = sdev->udev;
339 struct usb_host_endpoint *ep;
340 struct usb_endpoint_descriptor *epd = NULL;
341 int epnum = pdu->base.ep;
342 int dir = pdu->base.direction;
343
344 if (epnum < 0 || epnum > 15)
345 goto err_ret;
346
347 if (dir == USBIP_DIR_IN)
348 ep = udev->ep_in[epnum & 0x7f];
349 else
350 ep = udev->ep_out[epnum & 0x7f];
351 if (!ep)
352 goto err_ret;
353
354 epd = &ep->desc;
355
356 if (usb_endpoint_xfer_control(epd)) {
357 if (dir == USBIP_DIR_OUT)
358 return usb_sndctrlpipe(udev, epnum);
359 else
360 return usb_rcvctrlpipe(udev, epnum);
361 }
362
363 if (usb_endpoint_xfer_bulk(epd)) {
364 if (dir == USBIP_DIR_OUT)
365 return usb_sndbulkpipe(udev, epnum);
366 else
367 return usb_rcvbulkpipe(udev, epnum);
368 }
369
370 if (usb_endpoint_xfer_int(epd)) {
371 if (dir == USBIP_DIR_OUT)
372 return usb_sndintpipe(udev, epnum);
373 else
374 return usb_rcvintpipe(udev, epnum);
375 }
376
377 if (usb_endpoint_xfer_isoc(epd)) {
378 /* validate number of packets */
379 if (pdu->u.cmd_submit.number_of_packets < 0 ||
380 pdu->u.cmd_submit.number_of_packets >
381 USBIP_MAX_ISO_PACKETS) {
382 dev_err(&sdev->udev->dev,
383 "CMD_SUBMIT: isoc invalid num packets %d\n",
384 pdu->u.cmd_submit.number_of_packets);
385 return -1;
386 }
387 if (dir == USBIP_DIR_OUT)
388 return usb_sndisocpipe(udev, epnum);
389 else
390 return usb_rcvisocpipe(udev, epnum);
391 }
392
393err_ret:
394 /* NOT REACHED */
395 dev_err(&sdev->udev->dev, "CMD_SUBMIT: invalid epnum %d\n", epnum);
396 return -1;
397}
398
399static void masking_bogus_flags(struct urb *urb)
400{
401 int xfertype;
402 struct usb_device *dev;
403 struct usb_host_endpoint *ep;
404 int is_out;
405 unsigned int allowed;
406
407 if (!urb || urb->hcpriv || !urb->complete)
408 return;
409 dev = urb->dev;
410 if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
411 return;
412
413 ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
414 [usb_pipeendpoint(urb->pipe)];
415 if (!ep)
416 return;
417
418 xfertype = usb_endpoint_type(&ep->desc);
419 if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
420 struct usb_ctrlrequest *setup =
421 (struct usb_ctrlrequest *) urb->setup_packet;
422
423 if (!setup)
424 return;
425 is_out = !(setup->bRequestType & USB_DIR_IN) ||
426 !setup->wLength;
427 } else {
428 is_out = usb_endpoint_dir_out(&ep->desc);
429 }
430
431 /* enforce simple/standard policy */
432 allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
433 URB_DIR_MASK | URB_FREE_BUFFER);
434 switch (xfertype) {
435 case USB_ENDPOINT_XFER_BULK:
436 if (is_out)
437 allowed |= URB_ZERO_PACKET;
438 fallthrough;
439 default: /* all non-iso endpoints */
440 if (!is_out)
441 allowed |= URB_SHORT_NOT_OK;
442 break;
443 case USB_ENDPOINT_XFER_ISOC:
444 allowed |= URB_ISO_ASAP;
445 break;
446 }
447 urb->transfer_flags &= allowed;
448}
449
450static int stub_recv_xbuff(struct usbip_device *ud, struct stub_priv *priv)
451{
452 int ret;
453 int i;
454
455 for (i = 0; i < priv->num_urbs; i++) {
456 ret = usbip_recv_xbuff(ud, priv->urbs[i]);
457 if (ret < 0)
458 break;
459 }
460
461 return ret;
462}
463
464static void stub_recv_cmd_submit(struct stub_device *sdev,
465 struct usbip_header *pdu)
466{
467 struct stub_priv *priv;
468 struct usbip_device *ud = &sdev->ud;
469 struct usb_device *udev = sdev->udev;
470 struct scatterlist *sgl = NULL, *sg;
471 void *buffer = NULL;
472 unsigned long long buf_len;
473 int nents;
474 int num_urbs = 1;
475 int pipe = get_pipe(sdev, pdu);
476 int use_sg = pdu->u.cmd_submit.transfer_flags & USBIP_URB_DMA_MAP_SG;
477 int support_sg = 1;
478 int np = 0;
479 int ret, i;
480 int is_tweaked;
481
482 if (pipe == -1)
483 return;
484
485 /*
486 * Smatch reported the error case where use_sg is true and buf_len is 0.
487 * In this case, It adds SDEV_EVENT_ERROR_MALLOC and stub_priv will be
488 * released by stub event handler and connection will be shut down.
489 */
490 priv = stub_priv_alloc(sdev, pdu);
491 if (!priv)
492 return;
493
494 buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
495
496 if (use_sg && !buf_len) {
497 dev_err(&udev->dev, "sg buffer with zero length\n");
498 goto err_malloc;
499 }
500
501 /* allocate urb transfer buffer, if needed */
502 if (buf_len) {
503 if (use_sg) {
504 sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
505 if (!sgl)
506 goto err_malloc;
507
508 /* Check if the server's HCD supports SG */
509 if (!udev->bus->sg_tablesize) {
510 /*
511 * If the server's HCD doesn't support SG, break
512 * a single SG request into several URBs and map
513 * each SG list entry to corresponding URB
514 * buffer. The previously allocated SG list is
515 * stored in priv->sgl (If the server's HCD
516 * support SG, SG list is stored only in
517 * urb->sg) and it is used as an indicator that
518 * the server split single SG request into
519 * several URBs. Later, priv->sgl is used by
520 * stub_complete() and stub_send_ret_submit() to
521 * reassemble the divied URBs.
522 */
523 support_sg = 0;
524 num_urbs = nents;
525 priv->completed_urbs = 0;
526 pdu->u.cmd_submit.transfer_flags &=
527 ~USBIP_URB_DMA_MAP_SG;
528 }
529 } else {
530 buffer = kzalloc(buf_len, GFP_KERNEL);
531 if (!buffer)
532 goto err_malloc;
533 }
534 }
535
536 /* allocate urb array */
537 priv->num_urbs = num_urbs;
538 priv->urbs = kmalloc_array(num_urbs, sizeof(*priv->urbs), GFP_KERNEL);
539 if (!priv->urbs)
540 goto err_urbs;
541
542 /* setup a urb */
543 if (support_sg) {
544 if (usb_pipeisoc(pipe))
545 np = pdu->u.cmd_submit.number_of_packets;
546
547 priv->urbs[0] = usb_alloc_urb(np, GFP_KERNEL);
548 if (!priv->urbs[0])
549 goto err_urb;
550
551 if (buf_len) {
552 if (use_sg) {
553 priv->urbs[0]->sg = sgl;
554 priv->urbs[0]->num_sgs = nents;
555 priv->urbs[0]->transfer_buffer = NULL;
556 } else {
557 priv->urbs[0]->transfer_buffer = buffer;
558 }
559 }
560
561 /* copy urb setup packet */
562 priv->urbs[0]->setup_packet = kmemdup(&pdu->u.cmd_submit.setup,
563 8, GFP_KERNEL);
564 if (!priv->urbs[0]->setup_packet) {
565 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
566 return;
567 }
568
569 usbip_pack_pdu(pdu, priv->urbs[0], USBIP_CMD_SUBMIT, 0);
570 } else {
571 for_each_sg(sgl, sg, nents, i) {
572 priv->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
573 /* The URBs which is previously allocated will be freed
574 * in stub_device_cleanup_urbs() if error occurs.
575 */
576 if (!priv->urbs[i])
577 goto err_urb;
578
579 usbip_pack_pdu(pdu, priv->urbs[i], USBIP_CMD_SUBMIT, 0);
580 priv->urbs[i]->transfer_buffer = sg_virt(sg);
581 priv->urbs[i]->transfer_buffer_length = sg->length;
582 }
583 priv->sgl = sgl;
584 }
585
586 for (i = 0; i < num_urbs; i++) {
587 /* set other members from the base header of pdu */
588 priv->urbs[i]->context = (void *) priv;
589 priv->urbs[i]->dev = udev;
590 priv->urbs[i]->pipe = pipe;
591 priv->urbs[i]->complete = stub_complete;
592
593 /*
594 * all URBs belong to a single PDU, so a global is_tweaked flag is
595 * enough
596 */
597 is_tweaked = tweak_special_requests(priv->urbs[i]);
598
599 masking_bogus_flags(priv->urbs[i]);
600 }
601
602 if (stub_recv_xbuff(ud, priv) < 0)
603 return;
604
605 if (usbip_recv_iso(ud, priv->urbs[0]) < 0)
606 return;
607
608 /* urb is now ready to submit */
609 for (i = 0; i < priv->num_urbs; i++) {
610 if (!is_tweaked) {
611 ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
612
613 if (ret == 0)
614 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
615 pdu->base.seqnum);
616 else {
617 dev_err(&udev->dev, "submit_urb error, %d\n", ret);
618 usbip_dump_header(pdu);
619 usbip_dump_urb(priv->urbs[i]);
620
621 /*
622 * Pessimistic.
623 * This connection will be discarded.
624 */
625 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
626 break;
627 }
628 } else {
629 /*
630 * An identical URB was already submitted in
631 * tweak_special_requests(). Skip submitting this URB to not
632 * duplicate the request.
633 */
634 priv->urbs[i]->status = 0;
635 stub_complete(priv->urbs[i]);
636 }
637 }
638
639 usbip_dbg_stub_rx("Leave\n");
640 return;
641
642err_urb:
643 kfree(priv->urbs);
644err_urbs:
645 kfree(buffer);
646 sgl_free(sgl);
647err_malloc:
648 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
649}
650
651/* recv a pdu */
652static void stub_rx_pdu(struct usbip_device *ud)
653{
654 int ret;
655 struct usbip_header pdu;
656 struct stub_device *sdev = container_of(ud, struct stub_device, ud);
657 struct device *dev = &sdev->udev->dev;
658
659 usbip_dbg_stub_rx("Enter\n");
660
661 memset(&pdu, 0, sizeof(pdu));
662
663 /* receive a pdu header */
664 ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
665 if (ret != sizeof(pdu)) {
666 dev_err(dev, "recv a header, %d\n", ret);
667 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
668 return;
669 }
670
671 usbip_header_correct_endian(&pdu, 0);
672
673 if (usbip_dbg_flag_stub_rx)
674 usbip_dump_header(&pdu);
675
676 if (!valid_request(sdev, &pdu)) {
677 dev_err(dev, "recv invalid request\n");
678 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
679 return;
680 }
681
682 switch (pdu.base.command) {
683 case USBIP_CMD_UNLINK:
684 stub_recv_cmd_unlink(sdev, &pdu);
685 break;
686
687 case USBIP_CMD_SUBMIT:
688 stub_recv_cmd_submit(sdev, &pdu);
689 break;
690
691 default:
692 /* NOTREACHED */
693 dev_err(dev, "unknown pdu\n");
694 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
695 break;
696 }
697}
698
699int stub_rx_loop(void *data)
700{
701 struct usbip_device *ud = data;
702
703 while (!kthread_should_stop()) {
704 if (usbip_event_happened(ud))
705 break;
706
707 stub_rx_pdu(ud);
708 }
709
710 return 0;
711}