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 "../../usb/core/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
 366 static struct usb_host_endpoint *get_ep_from_epnum(struct usb_device *udev,
 367                 int epnum0)
 368 {
 369         struct usb_host_config *config;
 370         int i = 0, j = 0;
 371         struct usb_host_endpoint *ep = NULL;
 372         int epnum;
 373         int found = 0;
 374
 375         if (epnum0 == 0)
 376                 return &udev->ep0;
 377
 378         config = udev->actconfig;
 379         if (!config)
 380                 return NULL;
 381
 382         for (i = 0; i < config->desc.bNumInterfaces; i++) {
 383                 struct usb_host_interface *setting;
 384
 385                 setting = config->interface[i]->cur_altsetting;
 386
 387                 for (j = 0; j < setting->desc.bNumEndpoints; j++) {
 388                         ep = &setting->endpoint[j];
 389                         epnum = (ep->desc.bEndpointAddress & 0x7f);
 390
 391                         if (epnum == epnum0) {
 392                                 /* usbip_uinfo("found epnum %d\n", epnum0);*/
 393                                 found = 1;
 394                                 break;
 395                         }
 396                 }
 397         }
 398
 399         if (found)
 400                 return ep;
 401         else
 402                 return NULL;
 403 }
 404
 405
 406 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
 407 {
 408         struct usb_device *udev = interface_to_usbdev(sdev->interface);
 409         struct usb_host_endpoint *ep;
 410         struct usb_endpoint_descriptor *epd = NULL;
 411
 412         ep = get_ep_from_epnum(udev, epnum);
 413         if (!ep) {
 414                 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
 415                         epnum);
 416                 BUG();
 417         }
 418
 419         epd = &ep->desc;
 420
 421
 422 #if 0
 423         /* epnum 0 is always control */
 424         if (epnum == 0) {
 425                 if (dir == USBIP_DIR_OUT)
 426                         return usb_sndctrlpipe(udev, 0);
 427                 else
 428                         return usb_rcvctrlpipe(udev, 0);
 429         }
 430 #endif
 431
 432         if (usb_endpoint_xfer_control(epd)) {
 433                 if (dir == USBIP_DIR_OUT)
 434                         return usb_sndctrlpipe(udev, epnum);
 435                 else
 436                         return usb_rcvctrlpipe(udev, epnum);
 437         }
 438
 439         if (usb_endpoint_xfer_bulk(epd)) {
 440                 if (dir == USBIP_DIR_OUT)
 441                         return usb_sndbulkpipe(udev, epnum);
 442                 else
 443                         return usb_rcvbulkpipe(udev, epnum);
 444         }
 445
 446         if (usb_endpoint_xfer_int(epd)) {
 447                 if (dir == USBIP_DIR_OUT)
 448                         return usb_sndintpipe(udev, epnum);
 449                 else
 450                         return usb_rcvintpipe(udev, epnum);
 451         }
 452
 453         if (usb_endpoint_xfer_isoc(epd)) {
 454                 if (dir == USBIP_DIR_OUT)
 455                         return usb_sndisocpipe(udev, epnum);
 456                 else
 457                         return usb_rcvisocpipe(udev, epnum);
 458         }
 459
 460         /* NOT REACHED */
 461         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
 462         return 0;
 463 }
 464
 465 static void stub_recv_cmd_submit(struct stub_device *sdev,
 466                                  struct usbip_header *pdu)
 467 {
 468         int ret;
 469         struct stub_priv *priv;
 470         struct usbip_device *ud = &sdev->ud;
 471         struct usb_device *udev = interface_to_usbdev(sdev->interface);
 472         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 473
 474
 475         priv = stub_priv_alloc(sdev, pdu);
 476         if (!priv)
 477                 return;
 478
 479         /* setup a urb */
 480         if (usb_pipeisoc(pipe))
 481                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 482                                                                 GFP_KERNEL);
 483         else
 484                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 485
 486         if (!priv->urb) {
 487                 dev_err(&sdev->interface->dev, "malloc urb\n");
 488                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 489                 return;
 490         }
 491
 492         /* set priv->urb->transfer_buffer */
 493         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 494                 priv->urb->transfer_buffer =
 495                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 496                                                                 GFP_KERNEL);
 497                 if (!priv->urb->transfer_buffer) {
 498                         dev_err(&sdev->interface->dev, "malloc x_buff\n");
 499                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 500                         return;
 501                 }
 502         }
 503
 504         /* set priv->urb->setup_packet */
 505         priv->urb->setup_packet = kzalloc(8, GFP_KERNEL);
 506         if (!priv->urb->setup_packet) {
 507                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 508                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 509                 return;
 510         }
 511         memcpy(priv->urb->setup_packet, &pdu->u.cmd_submit.setup, 8);
 512
 513         /* set other members from the base header of pdu */
 514         priv->urb->context                = (void *) priv;
 515         priv->urb->dev                    = udev;
 516         priv->urb->pipe                   = pipe;
 517         priv->urb->complete               = stub_complete;
 518
 519         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 520
 521
 522         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 523                 return;
 524
 525         if (usbip_recv_iso(ud, priv->urb) < 0)
 526                 return;
 527
 528         /* no need to submit an intercepted request, but harmless? */
 529         tweak_special_requests(priv->urb);
 530
 531         /* urb is now ready to submit */
 532         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 533
 534         if (ret == 0)
 535                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 536                                                         pdu->base.seqnum);
 537         else {
 538                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 539                 usbip_dump_header(pdu);
 540                 usbip_dump_urb(priv->urb);
 541
 542                 /*
 543                  * Pessimistic.
 544                  * This connection will be discarded.
 545                  */
 546                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 547         }
 548
 549         usbip_dbg_stub_rx("Leave\n");
 550         return;
 551 }
 552
 553 /* recv a pdu */
 554 static void stub_rx_pdu(struct usbip_device *ud)
 555 {
 556         int ret;
 557         struct usbip_header pdu;
 558         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 559         struct device *dev = &sdev->interface->dev;
 560
 561         usbip_dbg_stub_rx("Enter\n");
 562
 563         memset(&pdu, 0, sizeof(pdu));
 564
 565         /* 1. receive a pdu header */
 566         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 567         if (ret != sizeof(pdu)) {
 568                 dev_err(dev, "recv a header, %d\n", ret);
 569                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 570                 return;
 571         }
 572
 573         usbip_header_correct_endian(&pdu, 0);
 574
 575         if (usbip_dbg_flag_stub_rx)
 576                 usbip_dump_header(&pdu);
 577
 578         if (!valid_request(sdev, &pdu)) {
 579                 dev_err(dev, "recv invalid request\n");
 580                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 581                 return;
 582         }
 583
 584         switch (pdu.base.command) {
 585         case USBIP_CMD_UNLINK:
 586                 stub_recv_cmd_unlink(sdev, &pdu);
 587                 break;
 588
 589         case USBIP_CMD_SUBMIT:
 590                 stub_recv_cmd_submit(sdev, &pdu);
 591                 break;
 592
 593         default:
 594                 /* NOTREACHED */
 595                 dev_err(dev, "unknown pdu\n");
 596                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 597                 return;
 598         }
 599
 600 }
 601
 602 void stub_rx_loop(struct usbip_task *ut)
 603 {
 604         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);
 605
 606         while (1) {
 607                 if (signal_pending(current)) {
 608                         usbip_dbg_stub_rx("signal caught!\n");
 609                         break;
 610                 }
 611
 612                 if (usbip_event_happened(ud))
 613                         break;
 614
 615                 stub_rx_pdu(ud);
 616         }
 617 }