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, "usb_clear_halt error: devnum %d endp "
 106                         "%d ret %d\n", urb->dev->devnum, target_endp, ret);
 107         else
 108                 dev_info(&urb->dev->dev, "usb_clear_halt done: devnum %d endp "
 109                          "%d\n", urb->dev->devnum, target_endp);
 110
 111         return ret;
 112 }
 113
 114 static int tweak_set_interface_cmd(struct urb *urb)
 115 {
 116         struct usb_ctrlrequest *req;
 117         __u16 alternate;
 118         __u16 interface;
 119         int ret;
 120
 121         req = (struct usb_ctrlrequest *) urb->setup_packet;
 122         alternate = le16_to_cpu(req->wValue);
 123         interface = le16_to_cpu(req->wIndex);
 124
 125         usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
 126                           interface, alternate);
 127
 128         ret = usb_set_interface(urb->dev, interface, alternate);
 129         if (ret < 0)
 130                 dev_err(&urb->dev->dev, "usb_set_interface error: inf %u alt "
 131                         "%u ret %d\n", interface, alternate, ret);
 132         else
 133                 dev_info(&urb->dev->dev, "usb_set_interface done: inf %u alt "
 134                          "%u\n", interface, 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         dev_info(&urb->dev->dev, "usb_set_configuration %d to %s... skip!\n",
 164                  config, dev_name(&urb->dev->dev));
 165
 166         return 0;
 167         /* return usb_driver_set_configuration(urb->dev, config); */
 168 }
 169
 170 static int tweak_reset_device_cmd(struct urb *urb)
 171 {
 172         struct stub_priv *priv = (struct stub_priv *) urb->context;
 173         struct stub_device *sdev = priv->sdev;
 174
 175         dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
 176
 177         /*
 178          * With the implementation of pre_reset and post_reset the driver no
 179          * longer unbinds. This allows the use of synchronous reset.
 180          */
 181
 182         if (usb_lock_device_for_reset(sdev->udev, sdev->interface)<0)
 183         {
 184                 dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
 185                 return 0;
 186         }
 187         usb_reset_device(sdev->udev);
 188         usb_unlock_device(sdev->udev);
 189
 190         return 0;
 191 }
 192
 193 /*
 194  * clear_halt, set_interface, and set_configuration require special tricks.
 195  */
 196 static void tweak_special_requests(struct urb *urb)
 197 {
 198         if (!urb || !urb->setup_packet)
 199                 return;
 200
 201         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 202                 return;
 203
 204         if (is_clear_halt_cmd(urb))
 205                 /* tweak clear_halt */
 206                  tweak_clear_halt_cmd(urb);
 207
 208         else if (is_set_interface_cmd(urb))
 209                 /* tweak set_interface */
 210                 tweak_set_interface_cmd(urb);
 211
 212         else if (is_set_configuration_cmd(urb))
 213                 /* tweak set_configuration */
 214                 tweak_set_configuration_cmd(urb);
 215
 216         else if (is_reset_device_cmd(urb))
 217                 tweak_reset_device_cmd(urb);
 218         else
 219                 usbip_dbg_stub_rx("no need to tweak\n");
 220 }
 221
 222 /*
 223  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 224  * By unlinking the urb asynchronously, stub_rx can continuously
 225  * process coming urbs.  Even if the urb is unlinked, its completion
 226  * handler will be called and stub_tx will send a return pdu.
 227  *
 228  * See also comments about unlinking strategy in vhci_hcd.c.
 229  */
 230 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 231                                 struct usbip_header *pdu)
 232 {
 233         unsigned long flags;
 234
 235         struct stub_priv *priv;
 236
 237         spin_lock_irqsave(&sdev->priv_lock, flags);
 238
 239         list_for_each_entry(priv, &sdev->priv_init, list) {
 240                 if (priv->seqnum == pdu->u.cmd_unlink.seqnum) {
 241                         int ret;
 242
 243                         dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
 244                                  priv->urb);
 245
 246                         /*
 247                          * This matched urb is not completed yet (i.e., be in
 248                          * flight in usb hcd hardware/driver). Now we are
 249                          * cancelling it. The unlinking flag means that we are
 250                          * now not going to return the normal result pdu of a
 251                          * submission request, but going to return a result pdu
 252                          * of the unlink request.
 253                          */
 254                         priv->unlinking = 1;
 255
 256                         /*
 257                          * In the case that unlinking flag is on, prev->seqnum
 258                          * is changed from the seqnum of the cancelling urb to
 259                          * the seqnum of the unlink request. This will be used
 260                          * to make the result pdu of the unlink request.
 261                          */
 262                         priv->seqnum = pdu->base.seqnum;
 263
 264                         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 265
 266                         /*
 267                          * usb_unlink_urb() is now out of spinlocking to avoid
 268                          * spinlock recursion since stub_complete() is
 269                          * sometimes called in this context but not in the
 270                          * interrupt context.  If stub_complete() is executed
 271                          * before we call usb_unlink_urb(), usb_unlink_urb()
 272                          * will return an error value. In this case, stub_tx
 273                          * will return the result pdu of this unlink request
 274                          * though submission is completed and actual unlinking
 275                          * is not executed. OK?
 276                          */
 277                         /* In the above case, urb->status is not -ECONNRESET,
 278                          * so a driver in a client host will know the failure
 279                          * of the unlink request ?
 280                          */
 281                         ret = usb_unlink_urb(priv->urb);
 282                         if (ret != -EINPROGRESS)
 283                                 dev_err(&priv->urb->dev->dev,
 284                                         "failed to unlink a urb %p, ret %d\n",
 285                                         priv->urb, ret);
 286                         return 0;
 287                 }
 288         }
 289
 290         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 291                           pdu->u.cmd_unlink.seqnum);
 292
 293         /*
 294          * The urb of the unlink target is not found in priv_init queue. It was
 295          * already completed and its results is/was going to be sent by a
 296          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 297          * return the completeness of this unlink request to vhci_hcd.
 298          */
 299         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 300
 301         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 302
 303         return 0;
 304 }
 305
 306 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 307 {
 308         struct usbip_device *ud = &sdev->ud;
 309
 310         if (pdu->base.devid == sdev->devid) {
 311                 spin_lock(&ud->lock);
 312                 if (ud->status == SDEV_ST_USED) {
 313                         /* A request is valid. */
 314                         spin_unlock(&ud->lock);
 315                         return 1;
 316                 }
 317                 spin_unlock(&ud->lock);
 318         }
 319
 320         return 0;
 321 }
 322
 323 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 324                                          struct usbip_header *pdu)
 325 {
 326         struct stub_priv *priv;
 327         struct usbip_device *ud = &sdev->ud;
 328         unsigned long flags;
 329
 330         spin_lock_irqsave(&sdev->priv_lock, flags);
 331
 332         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 333         if (!priv) {
 334                 dev_err(&sdev->interface->dev, "alloc stub_priv\n");
 335                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 336                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 337                 return NULL;
 338         }
 339
 340         priv->seqnum = pdu->base.seqnum;
 341         priv->sdev = sdev;
 342
 343         /*
 344          * After a stub_priv is linked to a list_head,
 345          * our error handler can free allocated data.
 346          */
 347         list_add_tail(&priv->list, &sdev->priv_init);
 348
 349         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 350
 351         return priv;
 352 }
 353
 354 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
 355 {
 356         struct usb_device *udev = sdev->udev;
 357         struct usb_host_endpoint *ep;
 358         struct usb_endpoint_descriptor *epd = NULL;
 359
 360         if (dir == USBIP_DIR_IN)
 361                 ep = udev->ep_in[epnum & 0x7f];
 362         else
 363                 ep = udev->ep_out[epnum & 0x7f];
 364         if (!ep) {
 365                 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
 366                         epnum);
 367                 BUG();
 368         }
 369
 370         epd = &ep->desc;
 371 #if 0
 372         /* epnum 0 is always control */
 373         if (epnum == 0) {
 374                 if (dir == USBIP_DIR_OUT)
 375                         return usb_sndctrlpipe(udev, 0);
 376                 else
 377                         return usb_rcvctrlpipe(udev, 0);
 378         }
 379 #endif
 380         if (usb_endpoint_xfer_control(epd)) {
 381                 if (dir == USBIP_DIR_OUT)
 382                         return usb_sndctrlpipe(udev, epnum);
 383                 else
 384                         return usb_rcvctrlpipe(udev, epnum);
 385         }
 386
 387         if (usb_endpoint_xfer_bulk(epd)) {
 388                 if (dir == USBIP_DIR_OUT)
 389                         return usb_sndbulkpipe(udev, epnum);
 390                 else
 391                         return usb_rcvbulkpipe(udev, epnum);
 392         }
 393
 394         if (usb_endpoint_xfer_int(epd)) {
 395                 if (dir == USBIP_DIR_OUT)
 396                         return usb_sndintpipe(udev, epnum);
 397                 else
 398                         return usb_rcvintpipe(udev, epnum);
 399         }
 400
 401         if (usb_endpoint_xfer_isoc(epd)) {
 402                 if (dir == USBIP_DIR_OUT)
 403                         return usb_sndisocpipe(udev, epnum);
 404                 else
 405                         return usb_rcvisocpipe(udev, epnum);
 406         }
 407
 408         /* NOT REACHED */
 409         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
 410         return 0;
 411 }
 412
 413 static void masking_bogus_flags(struct urb *urb)
 414 {
 415         int                             xfertype;
 416         struct usb_device               *dev;
 417         struct usb_host_endpoint        *ep;
 418         int                             is_out;
 419         unsigned int    allowed;
 420
 421         if (!urb || urb->hcpriv || !urb->complete)
 422                 return;
 423         dev = urb->dev;
 424         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
 425                 return;
 426
 427         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
 428                 [usb_pipeendpoint(urb->pipe)];
 429         if (!ep)
 430                 return;
 431
 432         xfertype = usb_endpoint_type(&ep->desc);
 433         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
 434                 struct usb_ctrlrequest *setup =
 435                         (struct usb_ctrlrequest *) urb->setup_packet;
 436
 437                 if (!setup)
 438                         return;
 439                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
 440                         !setup->wLength;
 441         } else {
 442                 is_out = usb_endpoint_dir_out(&ep->desc);
 443         }
 444
 445         /* enforce simple/standard policy */
 446         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
 447                    URB_DIR_MASK | URB_FREE_BUFFER);
 448         switch (xfertype) {
 449         case USB_ENDPOINT_XFER_BULK:
 450                 if (is_out)
 451                         allowed |= URB_ZERO_PACKET;
 452                 /* FALLTHROUGH */
 453         case USB_ENDPOINT_XFER_CONTROL:
 454                 allowed |= URB_NO_FSBR; /* only affects UHCI */
 455                 /* FALLTHROUGH */
 456         default:                        /* all non-iso endpoints */
 457                 if (!is_out)
 458                         allowed |= URB_SHORT_NOT_OK;
 459                 break;
 460         case USB_ENDPOINT_XFER_ISOC:
 461                 allowed |= URB_ISO_ASAP;
 462                 break;
 463         }
 464         urb->transfer_flags &= allowed;
 465 }
 466
 467 static void stub_recv_cmd_submit(struct stub_device *sdev,
 468                                  struct usbip_header *pdu)
 469 {
 470         int ret;
 471         struct stub_priv *priv;
 472         struct usbip_device *ud = &sdev->ud;
 473         struct usb_device *udev = sdev->udev;
 474         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 475
 476         priv = stub_priv_alloc(sdev, pdu);
 477         if (!priv)
 478                 return;
 479
 480         /* setup a urb */
 481         if (usb_pipeisoc(pipe))
 482                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 483                                           GFP_KERNEL);
 484         else
 485                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 486
 487         if (!priv->urb) {
 488                 dev_err(&sdev->interface->dev, "malloc urb\n");
 489                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 490                 return;
 491         }
 492
 493         /* set priv->urb->transfer_buffer */
 494         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 495                 priv->urb->transfer_buffer =
 496                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 497                                 GFP_KERNEL);
 498                 if (!priv->urb->transfer_buffer) {
 499                         dev_err(&sdev->interface->dev, "malloc x_buff\n");
 500                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 501                         return;
 502                 }
 503         }
 504
 505         /* set priv->urb->setup_packet */
 506         priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
 507                                           GFP_KERNEL);
 508         if (!priv->urb->setup_packet) {
 509                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 510                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 511                 return;
 512         }
 513
 514         /* set other members from the base header of pdu */
 515         priv->urb->context                = (void *) priv;
 516         priv->urb->dev                    = udev;
 517         priv->urb->pipe                   = pipe;
 518         priv->urb->complete               = stub_complete;
 519
 520         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 521
 522
 523         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 524                 return;
 525
 526         if (usbip_recv_iso(ud, priv->urb) < 0)
 527                 return;
 528
 529         /* no need to submit an intercepted request, but harmless? */
 530         tweak_special_requests(priv->urb);
 531
 532         masking_bogus_flags(priv->urb);
 533         /* urb is now ready to submit */
 534         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 535
 536         if (ret == 0)
 537                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 538                                   pdu->base.seqnum);
 539         else {
 540                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 541                 usbip_dump_header(pdu);
 542                 usbip_dump_urb(priv->urb);
 543
 544                 /*
 545                  * Pessimistic.
 546                  * This connection will be discarded.
 547                  */
 548                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 549         }
 550
 551         usbip_dbg_stub_rx("Leave\n");
 552         return;
 553 }
 554
 555 /* recv a pdu */
 556 static void stub_rx_pdu(struct usbip_device *ud)
 557 {
 558         int ret;
 559         struct usbip_header pdu;
 560         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 561         struct device *dev = &sdev->interface->dev;
 562
 563         usbip_dbg_stub_rx("Enter\n");
 564
 565         memset(&pdu, 0, sizeof(pdu));
 566
 567         /* 1. receive a pdu header */
 568         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 569         if (ret != sizeof(pdu)) {
 570                 dev_err(dev, "recv a header, %d\n", ret);
 571                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 572                 return;
 573         }
 574
 575         usbip_header_correct_endian(&pdu, 0);
 576
 577         if (usbip_dbg_flag_stub_rx)
 578                 usbip_dump_header(&pdu);
 579
 580         if (!valid_request(sdev, &pdu)) {
 581                 dev_err(dev, "recv invalid request\n");
 582                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 583                 return;
 584         }
 585
 586         switch (pdu.base.command) {
 587         case USBIP_CMD_UNLINK:
 588                 stub_recv_cmd_unlink(sdev, &pdu);
 589                 break;
 590
 591         case USBIP_CMD_SUBMIT:
 592                 stub_recv_cmd_submit(sdev, &pdu);
 593                 break;
 594
 595         default:
 596                 /* NOTREACHED */
 597                 dev_err(dev, "unknown pdu\n");
 598                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 599                 break;
 600         }
 601 }
 602
 603 int stub_rx_loop(void *data)
 604 {
 605         struct usbip_device *ud = data;
 606
 607         while (!kthread_should_stop()) {
 608                 if (usbip_event_happened(ud))
 609                         break;
 610
 611                 stub_rx_pdu(ud);
 612         }
 613
 614         return 0;
 615 }