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 #include <linux/kthread.h>
  22
  23 #include "usbip_common.h"
  24 #include "stub.h"
  25 #include <linux/usb/hcd.h>
  26
  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                 usbip_uinfo("clear_halt error: devnum %d endp %d, %d\n",
 106                                         urb->dev->devnum, target_endp, ret);
 107         else
 108                 usbip_uinfo("clear_halt done: devnum %d endp %d\n",
 109                                         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", interface,
 126                                                                 alternate);
 127
 128         ret = usb_set_interface(urb->dev, interface, alternate);
 129         if (ret < 0)
 130                 usbip_uinfo("set_interface error: inf %u alt %u, %d\n",
 131                                         interface, alternate, ret);
 132         else
 133                 usbip_uinfo("set_interface done: inf %u alt %u\n",
 134                                                         interface,
 135                                                         alternate);
 136
 137         return ret;
 138 }
 139
 140 static int tweak_set_configuration_cmd(struct urb *urb)
 141 {
 142         struct usb_ctrlrequest *req;
 143         __u16 config;
 144
 145         req = (struct usb_ctrlrequest *) urb->setup_packet;
 146         config = le16_to_cpu(req->wValue);
 147
 148         /*
 149          * I have never seen a multi-config device. Very rare.
 150          * For most devices, this will be called to choose a default
 151          * configuration only once in an initialization phase.
 152          *
 153          * set_configuration may change a device configuration and its device
 154          * drivers will be unbound and assigned for a new device configuration.
 155          * This means this usbip driver will be also unbound when called, then
 156          * eventually reassigned to the device as far as driver matching
 157          * condition is kept.
 158          *
 159          * Unfortunatelly, an existing usbip connection will be dropped
 160          * due to this driver unbinding. So, skip here.
 161          * A user may need to set a special configuration value before
 162          * exporting the device.
 163          */
 164         usbip_uinfo("set_configuration (%d) to %s\n", config,
 165                                                 dev_name(&urb->dev->dev));
 166         usbip_uinfo("but, skip!\n");
 167
 168         return 0;
 169         /* return usb_driver_set_configuration(urb->dev, config); */
 170 }
 171
 172 static int tweak_reset_device_cmd(struct urb *urb)
 173 {
 174         struct stub_priv *priv = (struct stub_priv *) urb->context;
 175         struct stub_device *sdev = priv->sdev;
 176
 177         usbip_uinfo("reset_device %s\n", dev_name(&urb->dev->dev));
 178
 179         /*
 180          * usb_lock_device_for_reset caused a deadlock: it causes the driver
 181          * to unbind. In the shutdown the rx thread is signalled to shut down
 182          * but this thread is pending in the usb_lock_device_for_reset.
 183          *
 184          * Instead queue the reset.
 185          *
 186          * Unfortunatly an existing usbip connection will be dropped due to
 187          * driver unbinding.
 188          */
 189         usb_queue_reset_device(sdev->interface);
 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
 238         spin_lock_irqsave(&sdev->priv_lock, flags);
 239
 240         list_for_each_entry(priv, &sdev->priv_init, list) {
 241                 if (priv->seqnum == pdu->u.cmd_unlink.seqnum) {
 242                         int ret;
 243
 244                         dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
 245                                  priv->urb);
 246
 247                         /*
 248                          * This matched urb is not completed yet (i.e., be in
 249                          * flight in usb hcd hardware/driver). Now we are
 250                          * cancelling it. The unlinking flag means that we are
 251                          * now not going to return the normal result pdu of a
 252                          * submission request, but going to return a result pdu
 253                          * of the unlink request.
 254                          */
 255                         priv->unlinking = 1;
 256
 257                         /*
 258                          * In the case that unlinking flag is on, prev->seqnum
 259                          * is changed from the seqnum of the cancelling urb to
 260                          * the seqnum of the unlink request. This will be used
 261                          * to make the result pdu of the unlink request.
 262                          */
 263                         priv->seqnum = pdu->base.seqnum;
 264
 265                         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 266
 267                         /*
 268                          * usb_unlink_urb() is now out of spinlocking to avoid
 269                          * spinlock recursion since stub_complete() is
 270                          * sometimes called in this context but not in the
 271                          * interrupt context.  If stub_complete() is executed
 272                          * before we call usb_unlink_urb(), usb_unlink_urb()
 273                          * will return an error value. In this case, stub_tx
 274                          * will return the result pdu of this unlink request
 275                          * though submission is completed and actual unlinking
 276                          * is not executed. OK?
 277                          */
 278                         /* In the above case, urb->status is not -ECONNRESET,
 279                          * so a driver in a client host will know the failure
 280                          * of the unlink request ?
 281                          */
 282                         ret = usb_unlink_urb(priv->urb);
 283                         if (ret != -EINPROGRESS)
 284                                 dev_err(&priv->urb->dev->dev,
 285                                         "failed to unlink a urb %p, ret %d\n",
 286                                         priv->urb, ret);
 287                         return 0;
 288                 }
 289         }
 290
 291         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 292                                                 pdu->u.cmd_unlink.seqnum);
 293
 294         /*
 295          * The urb of the unlink target is not found in priv_init queue. It was
 296          * already completed and its results is/was going to be sent by a
 297          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 298          * return the completeness of this unlink request to vhci_hcd.
 299          */
 300         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 301
 302         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 303
 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
 312         if (pdu->base.devid == sdev->devid) {
 313                 spin_lock(&ud->lock);
 314                 if (ud->status == SDEV_ST_USED) {
 315                         /* A request is valid. */
 316                         spin_unlock(&ud->lock);
 317                         return 1;
 318                 }
 319                 spin_unlock(&ud->lock);
 320         }
 321
 322         return 0;
 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
 374
 375 #if 0
 376         /* epnum 0 is always control */
 377         if (epnum == 0) {
 378                 if (dir == USBIP_DIR_OUT)
 379                         return usb_sndctrlpipe(udev, 0);
 380                 else
 381                         return usb_rcvctrlpipe(udev, 0);
 382         }
 383 #endif
 384
 385         if (usb_endpoint_xfer_control(epd)) {
 386                 if (dir == USBIP_DIR_OUT)
 387                         return usb_sndctrlpipe(udev, epnum);
 388                 else
 389                         return usb_rcvctrlpipe(udev, epnum);
 390         }
 391
 392         if (usb_endpoint_xfer_bulk(epd)) {
 393                 if (dir == USBIP_DIR_OUT)
 394                         return usb_sndbulkpipe(udev, epnum);
 395                 else
 396                         return usb_rcvbulkpipe(udev, epnum);
 397         }
 398
 399         if (usb_endpoint_xfer_int(epd)) {
 400                 if (dir == USBIP_DIR_OUT)
 401                         return usb_sndintpipe(udev, epnum);
 402                 else
 403                         return usb_rcvintpipe(udev, epnum);
 404         }
 405
 406         if (usb_endpoint_xfer_isoc(epd)) {
 407                 if (dir == USBIP_DIR_OUT)
 408                         return usb_sndisocpipe(udev, epnum);
 409                 else
 410                         return usb_rcvisocpipe(udev, epnum);
 411         }
 412
 413         /* NOT REACHED */
 414         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
 415         return 0;
 416 }
 417
 418 static void masking_bogus_flags(struct urb *urb)
 419 {
 420         int                             xfertype;
 421         struct usb_device               *dev;
 422         struct usb_host_endpoint        *ep;
 423         int                             is_out;
 424         unsigned int    allowed;
 425
 426         if (!urb || urb->hcpriv || !urb->complete)
 427                 return;
 428         dev = urb->dev;
 429         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
 430                 return;
 431
 432         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
 433                         [usb_pipeendpoint(urb->pipe)];
 434         if (!ep)
 435                 return;
 436
 437         xfertype = usb_endpoint_type(&ep->desc);
 438         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
 439                 struct usb_ctrlrequest *setup =
 440                                 (struct usb_ctrlrequest *) urb->setup_packet;
 441
 442                 if (!setup)
 443                         return;
 444                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
 445                                 !setup->wLength;
 446         } else {
 447                 is_out = usb_endpoint_dir_out(&ep->desc);
 448         }
 449
 450         /* enforce simple/standard policy */
 451         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
 452                    URB_DIR_MASK | URB_FREE_BUFFER);
 453         switch (xfertype) {
 454         case USB_ENDPOINT_XFER_BULK:
 455                 if (is_out)
 456                         allowed |= URB_ZERO_PACKET;
 457                 /* FALLTHROUGH */
 458         case USB_ENDPOINT_XFER_CONTROL:
 459                 allowed |= URB_NO_FSBR; /* only affects UHCI */
 460                 /* FALLTHROUGH */
 461         default:                        /* all non-iso endpoints */
 462                 if (!is_out)
 463                         allowed |= URB_SHORT_NOT_OK;
 464                 break;
 465         case USB_ENDPOINT_XFER_ISOC:
 466                 allowed |= URB_ISO_ASAP;
 467                 break;
 468         }
 469         urb->transfer_flags &= allowed;
 470 }
 471
 472 static void stub_recv_cmd_submit(struct stub_device *sdev,
 473                                  struct usbip_header *pdu)
 474 {
 475         int ret;
 476         struct stub_priv *priv;
 477         struct usbip_device *ud = &sdev->ud;
 478         struct usb_device *udev = sdev->udev;
 479         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 480
 481
 482         priv = stub_priv_alloc(sdev, pdu);
 483         if (!priv)
 484                 return;
 485
 486         /* setup a urb */
 487         if (usb_pipeisoc(pipe))
 488                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 489                                                                 GFP_KERNEL);
 490         else
 491                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 492
 493         if (!priv->urb) {
 494                 dev_err(&sdev->interface->dev, "malloc urb\n");
 495                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 496                 return;
 497         }
 498
 499         /* set priv->urb->transfer_buffer */
 500         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 501                 priv->urb->transfer_buffer =
 502                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 503                                                                 GFP_KERNEL);
 504                 if (!priv->urb->transfer_buffer) {
 505                         dev_err(&sdev->interface->dev, "malloc x_buff\n");
 506                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 507                         return;
 508                 }
 509         }
 510
 511         /* set priv->urb->setup_packet */
 512         priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
 513                                           GFP_KERNEL);
 514         if (!priv->urb->setup_packet) {
 515                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 516                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 517                 return;
 518         }
 519
 520         /* set other members from the base header of pdu */
 521         priv->urb->context                = (void *) priv;
 522         priv->urb->dev                    = udev;
 523         priv->urb->pipe                   = pipe;
 524         priv->urb->complete               = stub_complete;
 525
 526         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 527
 528
 529         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 530                 return;
 531
 532         if (usbip_recv_iso(ud, priv->urb) < 0)
 533                 return;
 534
 535         /* no need to submit an intercepted request, but harmless? */
 536         tweak_special_requests(priv->urb);
 537
 538         masking_bogus_flags(priv->urb);
 539         /* urb is now ready to submit */
 540         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 541
 542         if (ret == 0)
 543                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 544                                                         pdu->base.seqnum);
 545         else {
 546                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 547                 usbip_dump_header(pdu);
 548                 usbip_dump_urb(priv->urb);
 549
 550                 /*
 551                  * Pessimistic.
 552                  * This connection will be discarded.
 553                  */
 554                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 555         }
 556
 557         usbip_dbg_stub_rx("Leave\n");
 558         return;
 559 }
 560
 561 /* recv a pdu */
 562 static void stub_rx_pdu(struct usbip_device *ud)
 563 {
 564         int ret;
 565         struct usbip_header pdu;
 566         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 567         struct device *dev = &sdev->interface->dev;
 568
 569         usbip_dbg_stub_rx("Enter\n");
 570
 571         memset(&pdu, 0, sizeof(pdu));
 572
 573         /* 1. receive a pdu header */
 574         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 575         if (ret != sizeof(pdu)) {
 576                 dev_err(dev, "recv a header, %d\n", ret);
 577                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 578                 return;
 579         }
 580
 581         usbip_header_correct_endian(&pdu, 0);
 582
 583         if (usbip_dbg_flag_stub_rx)
 584                 usbip_dump_header(&pdu);
 585
 586         if (!valid_request(sdev, &pdu)) {
 587                 dev_err(dev, "recv invalid request\n");
 588                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 589                 return;
 590         }
 591
 592         switch (pdu.base.command) {
 593         case USBIP_CMD_UNLINK:
 594                 stub_recv_cmd_unlink(sdev, &pdu);
 595                 break;
 596
 597         case USBIP_CMD_SUBMIT:
 598                 stub_recv_cmd_submit(sdev, &pdu);
 599                 break;
 600
 601         default:
 602                 /* NOTREACHED */
 603                 dev_err(dev, "unknown pdu\n");
 604                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 605                 return;
 606         }
 607
 608 }
 609
 610 int stub_rx_loop(void *data)
 611 {
 612         struct usbip_device *ud = data;
 613
 614         while (!kthread_should_stop()) {
 615                 if (usbip_event_happened(ud))
 616                         break;
 617
 618                 stub_rx_pdu(ud);
 619         }
 620         return 0;
 621 }