Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[linux-2.6.git] / drivers / staging / usbip / stub_rx.c
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 <linux/slab.h>
21
22 #include "usbip_common.h"
23 #include "stub.h"
24 #include <linux/usb/hcd.h>
25
26
27 static int is_clear_halt_cmd(struct urb *urb)
28 {
29         struct usb_ctrlrequest *req;
30
31         req = (struct usb_ctrlrequest *) urb->setup_packet;
32
33          return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
34                  (req->bRequestType == USB_RECIP_ENDPOINT) &&
35                  (req->wValue == USB_ENDPOINT_HALT);
36 }
37
38 static int is_set_interface_cmd(struct urb *urb)
39 {
40         struct usb_ctrlrequest *req;
41
42         req = (struct usb_ctrlrequest *) urb->setup_packet;
43
44         return (req->bRequest == USB_REQ_SET_INTERFACE) &&
45                    (req->bRequestType == USB_RECIP_INTERFACE);
46 }
47
48 static int is_set_configuration_cmd(struct urb *urb)
49 {
50         struct usb_ctrlrequest *req;
51
52         req = (struct usb_ctrlrequest *) urb->setup_packet;
53
54         return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
55                    (req->bRequestType == USB_RECIP_DEVICE);
56 }
57
58 static int is_reset_device_cmd(struct urb *urb)
59 {
60         struct usb_ctrlrequest *req;
61         __u16 value;
62         __u16 index;
63
64         req = (struct usb_ctrlrequest *) urb->setup_packet;
65         value = le16_to_cpu(req->wValue);
66         index = le16_to_cpu(req->wIndex);
67
68         if ((req->bRequest == USB_REQ_SET_FEATURE) &&
69                         (req->bRequestType == USB_RT_PORT) &&
70                         (value == USB_PORT_FEAT_RESET)) {
71                 usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
72                 return 1;
73         } else
74                 return 0;
75 }
76
77 static int tweak_clear_halt_cmd(struct urb *urb)
78 {
79         struct usb_ctrlrequest *req;
80         int target_endp;
81         int target_dir;
82         int target_pipe;
83         int ret;
84
85         req = (struct usb_ctrlrequest *) urb->setup_packet;
86
87         /*
88          * The stalled endpoint is specified in the wIndex value. The endpoint
89          * of the urb is the target of this clear_halt request (i.e., control
90          * endpoint).
91          */
92         target_endp = le16_to_cpu(req->wIndex) & 0x000f;
93
94         /* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
95         target_dir = le16_to_cpu(req->wIndex) & 0x0080;
96
97         if (target_dir)
98                 target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
99         else
100                 target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
101
102         ret = usb_clear_halt(urb->dev, target_pipe);
103         if (ret < 0)
104                 usbip_uinfo("clear_halt error: devnum %d endp %d, %d\n",
105                                         urb->dev->devnum, target_endp, ret);
106         else
107                 usbip_uinfo("clear_halt done: devnum %d endp %d\n",
108                                         urb->dev->devnum, target_endp);
109
110         return ret;
111 }
112
113 static int tweak_set_interface_cmd(struct urb *urb)
114 {
115         struct usb_ctrlrequest *req;
116         __u16 alternate;
117         __u16 interface;
118         int ret;
119
120         req = (struct usb_ctrlrequest *) urb->setup_packet;
121         alternate = le16_to_cpu(req->wValue);
122         interface = le16_to_cpu(req->wIndex);
123
124         usbip_dbg_stub_rx("set_interface: inf %u alt %u\n", interface,
125                                                                 alternate);
126
127         ret = usb_set_interface(urb->dev, interface, alternate);
128         if (ret < 0)
129                 usbip_uinfo("set_interface error: inf %u alt %u, %d\n",
130                                         interface, alternate, ret);
131         else
132                 usbip_uinfo("set_interface done: inf %u alt %u\n",
133                                                         interface,
134                                                         alternate);
135
136         return ret;
137 }
138
139 static int tweak_set_configuration_cmd(struct urb *urb)
140 {
141         struct usb_ctrlrequest *req;
142         __u16 config;
143
144         req = (struct usb_ctrlrequest *) urb->setup_packet;
145         config = le16_to_cpu(req->wValue);
146
147         /*
148          * I have never seen a multi-config device. Very rare.
149          * For most devices, this will be called to choose a default
150          * configuration only once in an initialization phase.
151          *
152          * set_configuration may change a device configuration and its device
153          * drivers will be unbound and assigned for a new device configuration.
154          * This means this usbip driver will be also unbound when called, then
155          * eventually reassigned to the device as far as driver matching
156          * condition is kept.
157          *
158          * Unfortunatelly, an existing usbip connection will be dropped
159          * due to this driver unbinding. So, skip here.
160          * A user may need to set a special configuration value before
161          * exporting the device.
162          */
163         usbip_uinfo("set_configuration (%d) to %s\n", config,
164                                                 dev_name(&urb->dev->dev));
165         usbip_uinfo("but, skip!\n");
166
167         return 0;
168         /* return usb_driver_set_configuration(urb->dev, config); */
169 }
170
171 static int tweak_reset_device_cmd(struct urb *urb)
172 {
173         struct usb_ctrlrequest *req;
174         __u16 value;
175         __u16 index;
176         int ret;
177
178         req = (struct usb_ctrlrequest *) urb->setup_packet;
179         value = le16_to_cpu(req->wValue);
180         index = le16_to_cpu(req->wIndex);
181
182         usbip_uinfo("reset_device (port %d) to %s\n", index,
183                                                 dev_name(&urb->dev->dev));
184
185         /* all interfaces should be owned by usbip driver, so just reset it.  */
186         ret = usb_lock_device_for_reset(urb->dev, NULL);
187         if (ret < 0) {
188                 dev_err(&urb->dev->dev, "lock for reset\n");
189                 return ret;
190         }
191
192         /* try to reset the device */
193         ret = usb_reset_device(urb->dev);
194         if (ret < 0)
195                 dev_err(&urb->dev->dev, "device reset\n");
196
197         usb_unlock_device(urb->dev);
198
199         return ret;
200 }
201
202 /*
203  * clear_halt, set_interface, and set_configuration require special tricks.
204  */
205 static void tweak_special_requests(struct urb *urb)
206 {
207         if (!urb || !urb->setup_packet)
208                 return;
209
210         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
211                 return;
212
213         if (is_clear_halt_cmd(urb))
214                 /* tweak clear_halt */
215                  tweak_clear_halt_cmd(urb);
216
217         else if (is_set_interface_cmd(urb))
218                 /* tweak set_interface */
219                 tweak_set_interface_cmd(urb);
220
221         else if (is_set_configuration_cmd(urb))
222                 /* tweak set_configuration */
223                 tweak_set_configuration_cmd(urb);
224
225         else if (is_reset_device_cmd(urb))
226                 tweak_reset_device_cmd(urb);
227         else
228                 usbip_dbg_stub_rx("no need to tweak\n");
229 }
230
231 /*
232  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
233  * By unlinking the urb asynchronously, stub_rx can continuously
234  * process coming urbs.  Even if the urb is unlinked, its completion
235  * handler will be called and stub_tx will send a return pdu.
236  *
237  * See also comments about unlinking strategy in vhci_hcd.c.
238  */
239 static int stub_recv_cmd_unlink(struct stub_device *sdev,
240                                                 struct usbip_header *pdu)
241 {
242         unsigned long flags;
243
244         struct stub_priv *priv;
245
246
247         spin_lock_irqsave(&sdev->priv_lock, flags);
248
249         list_for_each_entry(priv, &sdev->priv_init, list) {
250                 if (priv->seqnum == pdu->u.cmd_unlink.seqnum) {
251                         int ret;
252
253                         dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
254                                  priv->urb);
255
256                         /*
257                          * This matched urb is not completed yet (i.e., be in
258                          * flight in usb hcd hardware/driver). Now we are
259                          * cancelling it. The unlinking flag means that we are
260                          * now not going to return the normal result pdu of a
261                          * submission request, but going to return a result pdu
262                          * of the unlink request.
263                          */
264                         priv->unlinking = 1;
265
266                         /*
267                          * In the case that unlinking flag is on, prev->seqnum
268                          * is changed from the seqnum of the cancelling urb to
269                          * the seqnum of the unlink request. This will be used
270                          * to make the result pdu of the unlink request.
271                          */
272                         priv->seqnum = pdu->base.seqnum;
273
274                         spin_unlock_irqrestore(&sdev->priv_lock, flags);
275
276                         /*
277                          * usb_unlink_urb() is now out of spinlocking to avoid
278                          * spinlock recursion since stub_complete() is
279                          * sometimes called in this context but not in the
280                          * interrupt context.  If stub_complete() is executed
281                          * before we call usb_unlink_urb(), usb_unlink_urb()
282                          * will return an error value. In this case, stub_tx
283                          * will return the result pdu of this unlink request
284                          * though submission is completed and actual unlinking
285                          * is not executed. OK?
286                          */
287                         /* In the above case, urb->status is not -ECONNRESET,
288                          * so a driver in a client host will know the failure
289                          * of the unlink request ?
290                          */
291                         ret = usb_unlink_urb(priv->urb);
292                         if (ret != -EINPROGRESS)
293                                 dev_err(&priv->urb->dev->dev,
294                                         "failed to unlink a urb %p, ret %d\n",
295                                         priv->urb, ret);
296                         return 0;
297                 }
298         }
299
300         usbip_dbg_stub_rx("seqnum %d is not pending\n",
301                                                 pdu->u.cmd_unlink.seqnum);
302
303         /*
304          * The urb of the unlink target is not found in priv_init queue. It was
305          * already completed and its results is/was going to be sent by a
306          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
307          * return the completeness of this unlink request to vhci_hcd.
308          */
309         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
310
311         spin_unlock_irqrestore(&sdev->priv_lock, flags);
312
313
314         return 0;
315 }
316
317 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
318 {
319         struct usbip_device *ud = &sdev->ud;
320
321         if (pdu->base.devid == sdev->devid) {
322                 spin_lock(&ud->lock);
323                 if (ud->status == SDEV_ST_USED) {
324                         /* A request is valid. */
325                         spin_unlock(&ud->lock);
326                         return 1;
327                 }
328                 spin_unlock(&ud->lock);
329         }
330
331         return 0;
332 }
333
334 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
335                                          struct usbip_header *pdu)
336 {
337         struct stub_priv *priv;
338         struct usbip_device *ud = &sdev->ud;
339         unsigned long flags;
340
341         spin_lock_irqsave(&sdev->priv_lock, flags);
342
343         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
344         if (!priv) {
345                 dev_err(&sdev->interface->dev, "alloc stub_priv\n");
346                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
347                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
348                 return NULL;
349         }
350
351         priv->seqnum = pdu->base.seqnum;
352         priv->sdev = sdev;
353
354         /*
355          * After a stub_priv is linked to a list_head,
356          * our error handler can free allocated data.
357          */
358         list_add_tail(&priv->list, &sdev->priv_init);
359
360         spin_unlock_irqrestore(&sdev->priv_lock, flags);
361
362         return priv;
363 }
364
365 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
366 {
367         struct usb_device *udev = sdev->udev;
368         struct usb_host_endpoint *ep;
369         struct usb_endpoint_descriptor *epd = NULL;
370
371         if (dir == USBIP_DIR_IN)
372                 ep = udev->ep_in[epnum & 0x7f];
373         else
374                 ep = udev->ep_out[epnum & 0x7f];
375         if (!ep) {
376                 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
377                         epnum);
378                 BUG();
379         }
380
381         epd = &ep->desc;
382
383
384 #if 0
385         /* epnum 0 is always control */
386         if (epnum == 0) {
387                 if (dir == USBIP_DIR_OUT)
388                         return usb_sndctrlpipe(udev, 0);
389                 else
390                         return usb_rcvctrlpipe(udev, 0);
391         }
392 #endif
393
394         if (usb_endpoint_xfer_control(epd)) {
395                 if (dir == USBIP_DIR_OUT)
396                         return usb_sndctrlpipe(udev, epnum);
397                 else
398                         return usb_rcvctrlpipe(udev, epnum);
399         }
400
401         if (usb_endpoint_xfer_bulk(epd)) {
402                 if (dir == USBIP_DIR_OUT)
403                         return usb_sndbulkpipe(udev, epnum);
404                 else
405                         return usb_rcvbulkpipe(udev, epnum);
406         }
407
408         if (usb_endpoint_xfer_int(epd)) {
409                 if (dir == USBIP_DIR_OUT)
410                         return usb_sndintpipe(udev, epnum);
411                 else
412                         return usb_rcvintpipe(udev, epnum);
413         }
414
415         if (usb_endpoint_xfer_isoc(epd)) {
416                 if (dir == USBIP_DIR_OUT)
417                         return usb_sndisocpipe(udev, epnum);
418                 else
419                         return usb_rcvisocpipe(udev, epnum);
420         }
421
422         /* NOT REACHED */
423         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
424         return 0;
425 }
426
427 static void masking_bogus_flags(struct urb *urb)
428 {
429         int                             xfertype;
430         struct usb_device               *dev;
431         struct usb_host_endpoint        *ep;
432         int                             is_out;
433         unsigned int    allowed;
434
435         if (!urb || urb->hcpriv || !urb->complete)
436                 return;
437         dev = urb->dev;
438         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
439                 return;
440
441         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
442                         [usb_pipeendpoint(urb->pipe)];
443         if (!ep)
444                 return;
445
446         xfertype = usb_endpoint_type(&ep->desc);
447         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
448                 struct usb_ctrlrequest *setup =
449                                 (struct usb_ctrlrequest *) urb->setup_packet;
450
451                 if (!setup)
452                         return;
453                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
454                                 !setup->wLength;
455         } else {
456                 is_out = usb_endpoint_dir_out(&ep->desc);
457         }
458
459         /* enforce simple/standard policy */
460         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
461                    URB_DIR_MASK | URB_FREE_BUFFER);
462         switch (xfertype) {
463         case USB_ENDPOINT_XFER_BULK:
464                 if (is_out)
465                         allowed |= URB_ZERO_PACKET;
466                 /* FALLTHROUGH */
467         case USB_ENDPOINT_XFER_CONTROL:
468                 allowed |= URB_NO_FSBR; /* only affects UHCI */
469                 /* FALLTHROUGH */
470         default:                        /* all non-iso endpoints */
471                 if (!is_out)
472                         allowed |= URB_SHORT_NOT_OK;
473                 break;
474         case USB_ENDPOINT_XFER_ISOC:
475                 allowed |= URB_ISO_ASAP;
476                 break;
477         }
478         urb->transfer_flags &= allowed;
479 }
480
481 static void stub_recv_cmd_submit(struct stub_device *sdev,
482                                  struct usbip_header *pdu)
483 {
484         int ret;
485         struct stub_priv *priv;
486         struct usbip_device *ud = &sdev->ud;
487         struct usb_device *udev = sdev->udev;
488         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
489
490
491         priv = stub_priv_alloc(sdev, pdu);
492         if (!priv)
493                 return;
494
495         /* setup a urb */
496         if (usb_pipeisoc(pipe))
497                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
498                                                                 GFP_KERNEL);
499         else
500                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
501
502         if (!priv->urb) {
503                 dev_err(&sdev->interface->dev, "malloc urb\n");
504                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
505                 return;
506         }
507
508         /* set priv->urb->transfer_buffer */
509         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
510                 priv->urb->transfer_buffer =
511                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
512                                                                 GFP_KERNEL);
513                 if (!priv->urb->transfer_buffer) {
514                         dev_err(&sdev->interface->dev, "malloc x_buff\n");
515                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
516                         return;
517                 }
518         }
519
520         /* set priv->urb->setup_packet */
521         priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
522                                           GFP_KERNEL);
523         if (!priv->urb->setup_packet) {
524                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
525                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
526                 return;
527         }
528
529         /* set other members from the base header of pdu */
530         priv->urb->context                = (void *) priv;
531         priv->urb->dev                    = udev;
532         priv->urb->pipe                   = pipe;
533         priv->urb->complete               = stub_complete;
534
535         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
536
537
538         if (usbip_recv_xbuff(ud, priv->urb) < 0)
539                 return;
540
541         if (usbip_recv_iso(ud, priv->urb) < 0)
542                 return;
543
544         /* no need to submit an intercepted request, but harmless? */
545         tweak_special_requests(priv->urb);
546
547         masking_bogus_flags(priv->urb);
548         /* urb is now ready to submit */
549         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
550
551         if (ret == 0)
552                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
553                                                         pdu->base.seqnum);
554         else {
555                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
556                 usbip_dump_header(pdu);
557                 usbip_dump_urb(priv->urb);
558
559                 /*
560                  * Pessimistic.
561                  * This connection will be discarded.
562                  */
563                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
564         }
565
566         usbip_dbg_stub_rx("Leave\n");
567         return;
568 }
569
570 /* recv a pdu */
571 static void stub_rx_pdu(struct usbip_device *ud)
572 {
573         int ret;
574         struct usbip_header pdu;
575         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
576         struct device *dev = &sdev->interface->dev;
577
578         usbip_dbg_stub_rx("Enter\n");
579
580         memset(&pdu, 0, sizeof(pdu));
581
582         /* 1. receive a pdu header */
583         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
584         if (ret != sizeof(pdu)) {
585                 dev_err(dev, "recv a header, %d\n", ret);
586                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
587                 return;
588         }
589
590         usbip_header_correct_endian(&pdu, 0);
591
592         if (usbip_dbg_flag_stub_rx)
593                 usbip_dump_header(&pdu);
594
595         if (!valid_request(sdev, &pdu)) {
596                 dev_err(dev, "recv invalid request\n");
597                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
598                 return;
599         }
600
601         switch (pdu.base.command) {
602         case USBIP_CMD_UNLINK:
603                 stub_recv_cmd_unlink(sdev, &pdu);
604                 break;
605
606         case USBIP_CMD_SUBMIT:
607                 stub_recv_cmd_submit(sdev, &pdu);
608                 break;
609
610         default:
611                 /* NOTREACHED */
612                 dev_err(dev, "unknown pdu\n");
613                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
614                 return;
615         }
616
617 }
618
619 void stub_rx_loop(struct usbip_task *ut)
620 {
621         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);
622
623         while (1) {
624                 if (signal_pending(current)) {
625                         usbip_dbg_stub_rx("signal caught!\n");
626                         break;
627                 }
628
629                 if (usbip_event_happened(ud))
630                         break;
631
632                 stub_rx_pdu(ud);
633         }
634 }