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