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 "usbip_common.h"
  21 #include "stub.h"
  22 #include "../../usb/core/hcd.h"
  23
  24
  25 static int is_clear_halt_cmd(struct urb *urb)
  26 {
  27         struct usb_ctrlrequest *req;
  28
  29         req = (struct usb_ctrlrequest *) urb->setup_packet;
  30
  31          return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
  32                  (req->bRequestType == USB_RECIP_ENDPOINT) &&
  33                  (req->wValue == USB_ENDPOINT_HALT);
  34 }
  35
  36 static int is_set_interface_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_INTERFACE) &&
  43                    (req->bRequestType == USB_RECIP_INTERFACE);
  44 }
  45
  46 static int is_set_configuration_cmd(struct urb *urb)
  47 {
  48         struct usb_ctrlrequest *req;
  49
  50         req = (struct usb_ctrlrequest *) urb->setup_packet;
  51
  52         return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
  53                    (req->bRequestType == USB_RECIP_DEVICE);
  54 }
  55
  56 static int is_reset_device_cmd(struct urb *urb)
  57 {
  58         struct usb_ctrlrequest *req;
  59         __u16 value;
  60         __u16 index;
  61
  62         req = (struct usb_ctrlrequest *) urb->setup_packet;
  63         value = le16_to_cpu(req->wValue);
  64         index = le16_to_cpu(req->wIndex);
  65
  66         if ((req->bRequest == USB_REQ_SET_FEATURE) &&
  67                         (req->bRequestType == USB_RT_PORT) &&
  68                         (value = USB_PORT_FEAT_RESET)) {
  69                 dbg_stub_rx("reset_device_cmd, port %u\n", index);
  70                 return 1;
  71         } else
  72                 return 0;
  73 }
  74
  75 static int tweak_clear_halt_cmd(struct urb *urb)
  76 {
  77         struct usb_ctrlrequest *req;
  78         int target_endp;
  79         int target_dir;
  80         int target_pipe;
  81         int ret;
  82
  83         req = (struct usb_ctrlrequest *) urb->setup_packet;
  84
  85         /*
  86          * The stalled endpoint is specified in the wIndex value. The endpoint
  87          * of the urb is the target of this clear_halt request (i.e., control
  88          * endpoint).
  89          */
  90         target_endp = le16_to_cpu(req->wIndex) & 0x000f;
  91
  92         /* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
  93         target_dir = le16_to_cpu(req->wIndex) & 0x0080;
  94
  95         if (target_dir)
  96                 target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
  97         else
  98                 target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
  99
 100         ret = usb_clear_halt(urb->dev, target_pipe);
 101         if (ret < 0)
 102                 uinfo("clear_halt error: devnum %d endp %d, %d\n",
 103                                 urb->dev->devnum, target_endp, ret);
 104         else
 105                 uinfo("clear_halt done: devnum %d endp %d\n",
 106                                 urb->dev->devnum, target_endp);
 107
 108         return ret;
 109 }
 110
 111 static int tweak_set_interface_cmd(struct urb *urb)
 112 {
 113         struct usb_ctrlrequest *req;
 114         __u16 alternate;
 115         __u16 interface;
 116         int ret;
 117
 118         req = (struct usb_ctrlrequest *) urb->setup_packet;
 119         alternate = le16_to_cpu(req->wValue);
 120         interface = le16_to_cpu(req->wIndex);
 121
 122         dbg_stub_rx("set_interface: inf %u alt %u\n", interface, alternate);
 123
 124         ret = usb_set_interface(urb->dev, interface, alternate);
 125         if (ret < 0)
 126                 uinfo("set_interface error: inf %u alt %u, %d\n",
 127                                 interface, alternate, ret);
 128         else
 129                 uinfo("set_interface done: inf %u alt %u\n",
 130                                                         interface,
 131                                                         alternate);
 132
 133         return ret;
 134 }
 135
 136 static int tweak_set_configuration_cmd(struct urb *urb)
 137 {
 138         struct usb_ctrlrequest *req;
 139         __u16 config;
 140
 141         req = (struct usb_ctrlrequest *) urb->setup_packet;
 142         config = le16_to_cpu(req->wValue);
 143
 144         /*
 145          * I have never seen a multi-config device. Very rare.
 146          * For most devices, this will be called to choose a default
 147          * configuration only once in an initialization phase.
 148          *
 149          * set_configuration may change a device configuration and its device
 150          * drivers will be unbound and assigned for a new device configuration.
 151          * This means this usbip driver will be also unbound when called, then
 152          * eventually reassigned to the device as far as driver matching
 153          * condition is kept.
 154          *
 155          * Unfortunatelly, an existing usbip connection will be dropped
 156          * due to this driver unbinding. So, skip here.
 157          * A user may need to set a special configuration value before
 158          * exporting the device.
 159          */
 160         uinfo("set_configuration (%d) to %s\n", config, dev_name(&urb->dev->dev));
 161         uinfo("but, skip!\n");
 162
 163         return 0;
 164         /* return usb_driver_set_configuration(urb->dev, config); */
 165 }
 166
 167 static int tweak_reset_device_cmd(struct urb *urb)
 168 {
 169         struct usb_ctrlrequest *req;
 170         __u16 value;
 171         __u16 index;
 172         int ret;
 173
 174         req = (struct usb_ctrlrequest *) urb->setup_packet;
 175         value = le16_to_cpu(req->wValue);
 176         index = le16_to_cpu(req->wIndex);
 177
 178         uinfo("reset_device (port %d) to %s\n", index, dev_name(&urb->dev->dev));
 179
 180         /* all interfaces should be owned by usbip driver, so just reset it.  */
 181         ret = usb_lock_device_for_reset(urb->dev, NULL);
 182         if (ret < 0) {
 183                 dev_err(&urb->dev->dev, "lock for reset\n");
 184                 return ret;
 185         }
 186
 187         /* try to reset the device */
 188         ret = usb_reset_device(urb->dev);
 189         if (ret < 0)
 190                 dev_err(&urb->dev->dev, "device reset\n");
 191
 192         usb_unlock_device(urb->dev);
 193
 194         return ret;
 195 }
 196
 197 /*
 198  * clear_halt, set_interface, and set_configuration require special tricks.
 199  */
 200 static void tweak_special_requests(struct urb *urb)
 201 {
 202         if (!urb || !urb->setup_packet)
 203                 return;
 204
 205         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 206                 return;
 207
 208         if (is_clear_halt_cmd(urb))
 209                 /* tweak clear_halt */
 210                  tweak_clear_halt_cmd(urb);
 211
 212         else if (is_set_interface_cmd(urb))
 213                 /* tweak set_interface */
 214                 tweak_set_interface_cmd(urb);
 215
 216         else if (is_set_configuration_cmd(urb))
 217                 /* tweak set_configuration */
 218                 tweak_set_configuration_cmd(urb);
 219
 220         else if (is_reset_device_cmd(urb))
 221                 tweak_reset_device_cmd(urb);
 222         else
 223                 dbg_stub_rx("no need to tweak\n");
 224 }
 225
 226 /*
 227  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 228  * By unlinking the urb asynchronously, stub_rx can continuously
 229  * process coming urbs.  Even if the urb is unlinked, its completion
 230  * handler will be called and stub_tx will send a return pdu.
 231  *
 232  * See also comments about unlinking strategy in vhci_hcd.c.
 233  */
 234 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 235                                                 struct usbip_header *pdu)
 236 {
 237         unsigned long flags;
 238
 239         struct stub_priv *priv;
 240
 241
 242         spin_lock_irqsave(&sdev->priv_lock, flags);
 243
 244         list_for_each_entry(priv, &sdev->priv_init, list) {
 245                 if (priv->seqnum == pdu->u.cmd_unlink.seqnum) {
 246                         int ret;
 247
 248                         dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
 249                                  priv->urb);
 250
 251                         /*
 252                          * This matched urb is not completed yet (i.e., be in
 253                          * flight in usb hcd hardware/driver). Now we are
 254                          * cancelling it. The unlinking flag means that we are
 255                          * now not going to return the normal result pdu of a
 256                          * submission request, but going to return a result pdu
 257                          * of the unlink request.
 258                          */
 259                         priv->unlinking = 1;
 260
 261                         /*
 262                          * In the case that unlinking flag is on, prev->seqnum
 263                          * is changed from the seqnum of the cancelling urb to
 264                          * the seqnum of the unlink request. This will be used
 265                          * to make the result pdu of the unlink request.
 266                          */
 267                         priv->seqnum = pdu->base.seqnum;
 268
 269                         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 270
 271                         /*
 272                          * usb_unlink_urb() is now out of spinlocking to avoid
 273                          * spinlock recursion since stub_complete() is
 274                          * sometimes called in this context but not in the
 275                          * interrupt context.  If stub_complete() is executed
 276                          * before we call usb_unlink_urb(), usb_unlink_urb()
 277                          * will return an error value. In this case, stub_tx
 278                          * will return the result pdu of this unlink request
 279                          * though submission is completed and actual unlinking
 280                          * is not executed. OK?
 281                          */
 282                         /* In the above case, urb->status is not -ECONNRESET,
 283                          * so a driver in a client host will know the failure
 284                          * of the unlink request ?
 285                          */
 286                         ret = usb_unlink_urb(priv->urb);
 287                         if (ret != -EINPROGRESS)
 288                                 dev_err(&priv->urb->dev->dev,
 289                                         "failed to unlink a urb %p, ret %d\n",
 290                                         priv->urb, ret);
 291                         return 0;
 292                 }
 293         }
 294
 295         dbg_stub_rx("seqnum %d is not pending\n", pdu->u.cmd_unlink.seqnum);
 296
 297         /*
 298          * The urb of the unlink target is not found in priv_init queue. It was
 299          * already completed and its results is/was going to be sent by a
 300          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 301          * return the completeness of this unlink request to vhci_hcd.
 302          */
 303         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 304
 305         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 306
 307
 308         return 0;
 309 }
 310
 311 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 312 {
 313         struct usbip_device *ud = &sdev->ud;
 314
 315         if (pdu->base.devid == sdev->devid) {
 316                 spin_lock(&ud->lock);
 317                 if (ud->status == SDEV_ST_USED) {
 318                         /* A request is valid. */
 319                         spin_unlock(&ud->lock);
 320                         return 1;
 321                 }
 322                 spin_unlock(&ud->lock);
 323         }
 324
 325         return 0;
 326 }
 327
 328 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 329                                          struct usbip_header *pdu)
 330 {
 331         struct stub_priv *priv;
 332         struct usbip_device *ud = &sdev->ud;
 333         unsigned long flags;
 334
 335         spin_lock_irqsave(&sdev->priv_lock, flags);
 336
 337         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 338         if (!priv) {
 339                 dev_err(&sdev->interface->dev, "alloc stub_priv\n");
 340                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 341                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 342                 return NULL;
 343         }
 344
 345         priv->seqnum = pdu->base.seqnum;
 346         priv->sdev = sdev;
 347
 348         /*
 349          * After a stub_priv is linked to a list_head,
 350          * our error handler can free allocated data.
 351          */
 352         list_add_tail(&priv->list, &sdev->priv_init);
 353
 354         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 355
 356         return priv;
 357 }
 358
 359
 360 static struct usb_host_endpoint *get_ep_from_epnum(struct usb_device *udev,
 361                 int epnum0)
 362 {
 363         struct usb_host_config *config;
 364         int i = 0, j = 0;
 365         struct usb_host_endpoint *ep = NULL;
 366         int epnum;
 367         int found = 0;
 368
 369         if (epnum0 == 0)
 370                 return &udev->ep0;
 371
 372         config = udev->actconfig;
 373         if (!config)
 374                 return NULL;
 375
 376         for (i = 0; i < config->desc.bNumInterfaces; i++) {
 377                 struct usb_host_interface *setting;
 378
 379                 setting = config->interface[i]->cur_altsetting;
 380
 381                 for (j = 0; j < setting->desc.bNumEndpoints; j++) {
 382                         ep = &setting->endpoint[j];
 383                         epnum = (ep->desc.bEndpointAddress & 0x7f);
 384
 385                         if (epnum == epnum0) {
 386                                 /* uinfo("found epnum %d\n", epnum0); */
 387                                 found = 1;
 388                                 break;
 389                         }
 390                 }
 391         }
 392
 393         if (found)
 394                 return ep;
 395         else
 396                 return NULL;
 397 }
 398
 399
 400 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
 401 {
 402         struct usb_device *udev = interface_to_usbdev(sdev->interface);
 403         struct usb_host_endpoint *ep;
 404         struct usb_endpoint_descriptor *epd = NULL;
 405
 406         ep = get_ep_from_epnum(udev, epnum);
 407         if (!ep) {
 408                 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
 409                         epnum);
 410                 BUG();
 411         }
 412
 413         epd = &ep->desc;
 414
 415
 416 #if 0
 417         /* epnum 0 is always control */
 418         if (epnum == 0) {
 419                 if (dir == USBIP_DIR_OUT)
 420                         return usb_sndctrlpipe(udev, 0);
 421                 else
 422                         return usb_rcvctrlpipe(udev, 0);
 423         }
 424 #endif
 425
 426         if (usb_endpoint_xfer_control(epd)) {
 427                 if (dir == USBIP_DIR_OUT)
 428                         return usb_sndctrlpipe(udev, epnum);
 429                 else
 430                         return usb_rcvctrlpipe(udev, epnum);
 431         }
 432
 433         if (usb_endpoint_xfer_bulk(epd)) {
 434                 if (dir == USBIP_DIR_OUT)
 435                         return usb_sndbulkpipe(udev, epnum);
 436                 else
 437                         return usb_rcvbulkpipe(udev, epnum);
 438         }
 439
 440         if (usb_endpoint_xfer_int(epd)) {
 441                 if (dir == USBIP_DIR_OUT)
 442                         return usb_sndintpipe(udev, epnum);
 443                 else
 444                         return usb_rcvintpipe(udev, epnum);
 445         }
 446
 447         if (usb_endpoint_xfer_isoc(epd)) {
 448                 if (dir == USBIP_DIR_OUT)
 449                         return usb_sndisocpipe(udev, epnum);
 450                 else
 451                         return usb_rcvisocpipe(udev, epnum);
 452         }
 453
 454         /* NOT REACHED */
 455         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
 456         return 0;
 457 }
 458
 459 static void stub_recv_cmd_submit(struct stub_device *sdev,
 460                                  struct usbip_header *pdu)
 461 {
 462         int ret;
 463         struct stub_priv *priv;
 464         struct usbip_device *ud = &sdev->ud;
 465         struct usb_device *udev = interface_to_usbdev(sdev->interface);
 466         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 467
 468
 469         priv = stub_priv_alloc(sdev, pdu);
 470         if (!priv)
 471                 return;
 472
 473         /* setup a urb */
 474         if (usb_pipeisoc(pipe))
 475                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 476                                                                 GFP_KERNEL);
 477         else
 478                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 479
 480         if (!priv->urb) {
 481                 dev_err(&sdev->interface->dev, "malloc urb\n");
 482                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 483                 return;
 484         }
 485
 486         /* set priv->urb->transfer_buffer */
 487         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 488                 priv->urb->transfer_buffer =
 489                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 490                                                                 GFP_KERNEL);
 491                 if (!priv->urb->transfer_buffer) {
 492                         dev_err(&sdev->interface->dev, "malloc x_buff\n");
 493                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 494                         return;
 495                 }
 496         }
 497
 498         /* set priv->urb->setup_packet */
 499         priv->urb->setup_packet = kzalloc(8, GFP_KERNEL);
 500         if (!priv->urb->setup_packet) {
 501                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 502                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 503                 return;
 504         }
 505         memcpy(priv->urb->setup_packet, &pdu->u.cmd_submit.setup, 8);
 506
 507         /* set other members from the base header of pdu */
 508         priv->urb->context                = (void *) priv;
 509         priv->urb->dev                    = udev;
 510         priv->urb->pipe                   = pipe;
 511         priv->urb->complete               = stub_complete;
 512
 513         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 514
 515
 516         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 517                 return;
 518
 519         if (usbip_recv_iso(ud, priv->urb) < 0)
 520                 return;
 521
 522         /* no need to submit an intercepted request, but harmless? */
 523         tweak_special_requests(priv->urb);
 524
 525         /* urb is now ready to submit */
 526         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 527
 528         if (ret == 0)
 529                 dbg_stub_rx("submit urb ok, seqnum %u\n", pdu->base.seqnum);
 530         else {
 531                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 532                 usbip_dump_header(pdu);
 533                 usbip_dump_urb(priv->urb);
 534
 535                 /*
 536                  * Pessimistic.
 537                  * This connection will be discarded.
 538                  */
 539                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 540         }
 541
 542         dbg_stub_rx("Leave\n");
 543         return;
 544 }
 545
 546 /* recv a pdu */
 547 static void stub_rx_pdu(struct usbip_device *ud)
 548 {
 549         int ret;
 550         struct usbip_header pdu;
 551         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 552         struct device *dev = &sdev->interface->dev;
 553
 554         dbg_stub_rx("Enter\n");
 555
 556         memset(&pdu, 0, sizeof(pdu));
 557
 558         /* 1. receive a pdu header */
 559         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 560         if (ret != sizeof(pdu)) {
 561                 dev_err(dev, "recv a header, %d\n", ret);
 562                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 563                 return;
 564         }
 565
 566         usbip_header_correct_endian(&pdu, 0);
 567
 568         if (dbg_flag_stub_rx)
 569                 usbip_dump_header(&pdu);
 570
 571         if (!valid_request(sdev, &pdu)) {
 572                 dev_err(dev, "recv invalid request\n");
 573                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 574                 return;
 575         }
 576
 577         switch (pdu.base.command) {
 578         case USBIP_CMD_UNLINK:
 579                 stub_recv_cmd_unlink(sdev, &pdu);
 580                 break;
 581
 582         case USBIP_CMD_SUBMIT:
 583                 stub_recv_cmd_submit(sdev, &pdu);
 584                 break;
 585
 586         default:
 587                 /* NOTREACHED */
 588                 dev_err(dev, "unknown pdu\n");
 589                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 590                 return;
 591         }
 592
 593 }
 594
 595 void stub_rx_loop(struct usbip_task *ut)
 596 {
 597         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);
 598
 599         while (1) {
 600                 if (signal_pending(current)) {
 601                         dbg_stub_rx("signal caught!\n");
 602                         break;
 603                 }
 604
 605                 if (usbip_event_happend(ud))
 606                         break;
 607
 608                 stub_rx_pdu(ud);
 609         }
 610 }