Pileus Git - ~andy/linux/blob - drivers/staging/usbip/stub_rx.c

   1 /*
   2  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   3  *
   4  * This is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17  * USA.
  18  */
  19
  20 #include <linux/slab.h>
  21
  22 #include "usbip_common.h"
  23 #include "stub.h"
  24 #include <linux/usb/hcd.h>
  25
  26
  27 static int is_clear_halt_cmd(struct urb *urb)
  28 {
  29         struct usb_ctrlrequest *req;
  30
  31         req = (struct usb_ctrlrequest *) urb->setup_packet;
  32
  33          return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
  34                  (req->bRequestType == USB_RECIP_ENDPOINT) &&
  35                  (req->wValue == USB_ENDPOINT_HALT);
  36 }
  37
  38 static int is_set_interface_cmd(struct urb *urb)
  39 {
  40         struct usb_ctrlrequest *req;
  41
  42         req = (struct usb_ctrlrequest *) urb->setup_packet;
  43
  44         return (req->bRequest == USB_REQ_SET_INTERFACE) &&
  45                    (req->bRequestType == USB_RECIP_INTERFACE);
  46 }
  47
  48 static int is_set_configuration_cmd(struct urb *urb)
  49 {
  50         struct usb_ctrlrequest *req;
  51
  52         req = (struct usb_ctrlrequest *) urb->setup_packet;
  53
  54         return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
  55                    (req->bRequestType == USB_RECIP_DEVICE);
  56 }
  57
  58 static int is_reset_device_cmd(struct urb *urb)
  59 {
  60         struct usb_ctrlrequest *req;
  61         __u16 value;
  62         __u16 index;
  63
  64         req = (struct usb_ctrlrequest *) urb->setup_packet;
  65         value = le16_to_cpu(req->wValue);
  66         index = le16_to_cpu(req->wIndex);
  67
  68         if ((req->bRequest == USB_REQ_SET_FEATURE) &&
  69                         (req->bRequestType == USB_RT_PORT) &&
  70                         (value == USB_PORT_FEAT_RESET)) {
  71                 usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
  72                 return 1;
  73         } else
  74                 return 0;
  75 }
  76
  77 static int tweak_clear_halt_cmd(struct urb *urb)
  78 {
  79         struct usb_ctrlrequest *req;
  80         int target_endp;
  81         int target_dir;
  82         int target_pipe;
  83         int ret;
  84
  85         req = (struct usb_ctrlrequest *) urb->setup_packet;
  86
  87         /*
  88          * The stalled endpoint is specified in the wIndex value. The endpoint
  89          * of the urb is the target of this clear_halt request (i.e., control
  90          * endpoint).
  91          */
  92         target_endp = le16_to_cpu(req->wIndex) & 0x000f;
  93
  94         /* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
  95         target_dir = le16_to_cpu(req->wIndex) & 0x0080;
  96
  97         if (target_dir)
  98                 target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
  99         else
 100                 target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
 101
 102         ret = usb_clear_halt(urb->dev, target_pipe);
 103         if (ret < 0)
 104                 usbip_uinfo("clear_halt error: devnum %d endp %d, %d\n",
 105                                         urb->dev->devnum, target_endp, ret);
 106         else
 107                 usbip_uinfo("clear_halt done: devnum %d endp %d\n",
 108                                         urb->dev->devnum, target_endp);
 109
 110         return ret;
 111 }
 112
 113 static int tweak_set_interface_cmd(struct urb *urb)
 114 {
 115         struct usb_ctrlrequest *req;
 116         __u16 alternate;
 117         __u16 interface;
 118         int ret;
 119
 120         req = (struct usb_ctrlrequest *) urb->setup_packet;
 121         alternate = le16_to_cpu(req->wValue);
 122         interface = le16_to_cpu(req->wIndex);
 123
 124         usbip_dbg_stub_rx("set_interface: inf %u alt %u\n", interface,
 125                                                                 alternate);
 126
 127         ret = usb_set_interface(urb->dev, interface, alternate);
 128         if (ret < 0)
 129                 usbip_uinfo("set_interface error: inf %u alt %u, %d\n",
 130                                         interface, alternate, ret);
 131         else
 132                 usbip_uinfo("set_interface done: inf %u alt %u\n",
 133                                                         interface,
 134                                                         alternate);
 135
 136         return ret;
 137 }
 138
 139 static int tweak_set_configuration_cmd(struct urb *urb)
 140 {
 141         struct usb_ctrlrequest *req;
 142         __u16 config;
 143
 144         req = (struct usb_ctrlrequest *) urb->setup_packet;
 145         config = le16_to_cpu(req->wValue);
 146
 147         /*
 148          * I have never seen a multi-config device. Very rare.
 149          * For most devices, this will be called to choose a default
 150          * configuration only once in an initialization phase.
 151          *
 152          * set_configuration may change a device configuration and its device
 153          * drivers will be unbound and assigned for a new device configuration.
 154          * This means this usbip driver will be also unbound when called, then
 155          * eventually reassigned to the device as far as driver matching
 156          * condition is kept.
 157          *
 158          * Unfortunatelly, an existing usbip connection will be dropped
 159          * due to this driver unbinding. So, skip here.
 160          * A user may need to set a special configuration value before
 161          * exporting the device.
 162          */
 163         usbip_uinfo("set_configuration (%d) to %s\n", config,
 164                                                 dev_name(&urb->dev->dev));
 165         usbip_uinfo("but, skip!\n");
 166
 167         return 0;
 168         /* return usb_driver_set_configuration(urb->dev, config); */
 169 }
 170
 171 static int tweak_reset_device_cmd(struct urb *urb)
 172 {
 173         struct usb_ctrlrequest *req;
 174         __u16 value;
 175         __u16 index;
 176         int ret;
 177
 178         req = (struct usb_ctrlrequest *) urb->setup_packet;
 179         value = le16_to_cpu(req->wValue);
 180         index = le16_to_cpu(req->wIndex);
 181
 182         usbip_uinfo("reset_device (port %d) to %s\n", index,
 183                                                 dev_name(&urb->dev->dev));
 184
 185         /* all interfaces should be owned by usbip driver, so just reset it.  */
 186         ret = usb_lock_device_for_reset(urb->dev, NULL);
 187         if (ret < 0) {
 188                 dev_err(&urb->dev->dev, "lock for reset\n");
 189                 return ret;
 190         }
 191
 192         /* try to reset the device */
 193         ret = usb_reset_device(urb->dev);
 194         if (ret < 0)
 195                 dev_err(&urb->dev->dev, "device reset\n");
 196
 197         usb_unlock_device(urb->dev);
 198
 199         return ret;
 200 }
 201
 202 /*
 203  * clear_halt, set_interface, and set_configuration require special tricks.
 204  */
 205 static void tweak_special_requests(struct urb *urb)
 206 {
 207         if (!urb || !urb->setup_packet)
 208                 return;
 209
 210         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 211                 return;
 212
 213         if (is_clear_halt_cmd(urb))
 214                 /* tweak clear_halt */
 215                  tweak_clear_halt_cmd(urb);
 216
 217         else if (is_set_interface_cmd(urb))
 218                 /* tweak set_interface */
 219                 tweak_set_interface_cmd(urb);
 220
 221         else if (is_set_configuration_cmd(urb))
 222                 /* tweak set_configuration */
 223                 tweak_set_configuration_cmd(urb);
 224
 225         else if (is_reset_device_cmd(urb))
 226                 tweak_reset_device_cmd(urb);
 227         else
 228                 usbip_dbg_stub_rx("no need to tweak\n");
 229 }
 230
 231 /*
 232  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 233  * By unlinking the urb asynchronously, stub_rx can continuously
 234  * process coming urbs.  Even if the urb is unlinked, its completion
 235  * handler will be called and stub_tx will send a return pdu.
 236  *
 237  * See also comments about unlinking strategy in vhci_hcd.c.
 238  */
 239 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 240                                                 struct usbip_header *pdu)
 241 {
 242         unsigned long flags;
 243
 244         struct stub_priv *priv;
 245
 246
 247         spin_lock_irqsave(&sdev->priv_lock, flags);
 248
 249         list_for_each_entry(priv, &sdev->priv_init, list) {
 250                 if (priv->seqnum == pdu->u.cmd_unlink.seqnum) {
 251                         int ret;
 252
 253                         dev_info(&priv->urb->dev->dev, "unlink urb %p\n",
 254                                  priv->urb);
 255
 256                         /*
 257                          * This matched urb is not completed yet (i.e., be in
 258                          * flight in usb hcd hardware/driver). Now we are
 259                          * cancelling it. The unlinking flag means that we are
 260                          * now not going to return the normal result pdu of a
 261                          * submission request, but going to return a result pdu
 262                          * of the unlink request.
 263                          */
 264                         priv->unlinking = 1;
 265
 266                         /*
 267                          * In the case that unlinking flag is on, prev->seqnum
 268                          * is changed from the seqnum of the cancelling urb to
 269                          * the seqnum of the unlink request. This will be used
 270                          * to make the result pdu of the unlink request.
 271                          */
 272                         priv->seqnum = pdu->base.seqnum;
 273
 274                         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 275
 276                         /*
 277                          * usb_unlink_urb() is now out of spinlocking to avoid
 278                          * spinlock recursion since stub_complete() is
 279                          * sometimes called in this context but not in the
 280                          * interrupt context.  If stub_complete() is executed
 281                          * before we call usb_unlink_urb(), usb_unlink_urb()
 282                          * will return an error value. In this case, stub_tx
 283                          * will return the result pdu of this unlink request
 284                          * though submission is completed and actual unlinking
 285                          * is not executed. OK?
 286                          */
 287                         /* In the above case, urb->status is not -ECONNRESET,
 288                          * so a driver in a client host will know the failure
 289                          * of the unlink request ?
 290                          */
 291                         ret = usb_unlink_urb(priv->urb);
 292                         if (ret != -EINPROGRESS)
 293                                 dev_err(&priv->urb->dev->dev,
 294                                         "failed to unlink a urb %p, ret %d\n",
 295                                         priv->urb, ret);
 296                         return 0;
 297                 }
 298         }
 299
 300         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 301                                                 pdu->u.cmd_unlink.seqnum);
 302
 303         /*
 304          * The urb of the unlink target is not found in priv_init queue. It was
 305          * already completed and its results is/was going to be sent by a
 306          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 307          * return the completeness of this unlink request to vhci_hcd.
 308          */
 309         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 310
 311         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 312
 313
 314         return 0;
 315 }
 316
 317 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 318 {
 319         struct usbip_device *ud = &sdev->ud;
 320
 321         if (pdu->base.devid == sdev->devid) {
 322                 spin_lock(&ud->lock);
 323                 if (ud->status == SDEV_ST_USED) {
 324                         /* A request is valid. */
 325                         spin_unlock(&ud->lock);
 326                         return 1;
 327                 }
 328                 spin_unlock(&ud->lock);
 329         }
 330
 331         return 0;
 332 }
 333
 334 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 335                                          struct usbip_header *pdu)
 336 {
 337         struct stub_priv *priv;
 338         struct usbip_device *ud = &sdev->ud;
 339         unsigned long flags;
 340
 341         spin_lock_irqsave(&sdev->priv_lock, flags);
 342
 343         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 344         if (!priv) {
 345                 dev_err(&sdev->interface->dev, "alloc stub_priv\n");
 346                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 347                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 348                 return NULL;
 349         }
 350
 351         priv->seqnum = pdu->base.seqnum;
 352         priv->sdev = sdev;
 353
 354         /*
 355          * After a stub_priv is linked to a list_head,
 356          * our error handler can free allocated data.
 357          */
 358         list_add_tail(&priv->list, &sdev->priv_init);
 359
 360         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 361
 362         return priv;
 363 }
 364
 365 static int get_pipe(struct stub_device *sdev, int epnum, int dir)
 366 {
 367         struct usb_device *udev = sdev->udev;
 368         struct usb_host_endpoint *ep;
 369         struct usb_endpoint_descriptor *epd = NULL;
 370
 371         if (dir == USBIP_DIR_IN)
 372                 ep = udev->ep_in[epnum & 0x7f];
 373         else
 374                 ep = udev->ep_out[epnum & 0x7f];
 375         if (!ep) {
 376                 dev_err(&sdev->interface->dev, "no such endpoint?, %d\n",
 377                         epnum);
 378                 BUG();
 379         }
 380
 381         epd = &ep->desc;
 382
 383
 384 #if 0
 385         /* epnum 0 is always control */
 386         if (epnum == 0) {
 387                 if (dir == USBIP_DIR_OUT)
 388                         return usb_sndctrlpipe(udev, 0);
 389                 else
 390                         return usb_rcvctrlpipe(udev, 0);
 391         }
 392 #endif
 393
 394         if (usb_endpoint_xfer_control(epd)) {
 395                 if (dir == USBIP_DIR_OUT)
 396                         return usb_sndctrlpipe(udev, epnum);
 397                 else
 398                         return usb_rcvctrlpipe(udev, epnum);
 399         }
 400
 401         if (usb_endpoint_xfer_bulk(epd)) {
 402                 if (dir == USBIP_DIR_OUT)
 403                         return usb_sndbulkpipe(udev, epnum);
 404                 else
 405                         return usb_rcvbulkpipe(udev, epnum);
 406         }
 407
 408         if (usb_endpoint_xfer_int(epd)) {
 409                 if (dir == USBIP_DIR_OUT)
 410                         return usb_sndintpipe(udev, epnum);
 411                 else
 412                         return usb_rcvintpipe(udev, epnum);
 413         }
 414
 415         if (usb_endpoint_xfer_isoc(epd)) {
 416                 if (dir == USBIP_DIR_OUT)
 417                         return usb_sndisocpipe(udev, epnum);
 418                 else
 419                         return usb_rcvisocpipe(udev, epnum);
 420         }
 421
 422         /* NOT REACHED */
 423         dev_err(&sdev->interface->dev, "get pipe, epnum %d\n", epnum);
 424         return 0;
 425 }
 426
 427 static void masking_bogus_flags(struct urb *urb)
 428 {
 429         int                             xfertype;
 430         struct usb_device               *dev;
 431         struct usb_host_endpoint        *ep;
 432         int                             is_out;
 433         unsigned int    allowed;
 434
 435         if (!urb || urb->hcpriv || !urb->complete)
 436                 return;
 437         dev = urb->dev;
 438         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
 439                 return;
 440
 441         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
 442                         [usb_pipeendpoint(urb->pipe)];
 443         if (!ep)
 444                 return;
 445
 446         xfertype = usb_endpoint_type(&ep->desc);
 447         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
 448                 struct usb_ctrlrequest *setup =
 449                                 (struct usb_ctrlrequest *) urb->setup_packet;
 450
 451                 if (!setup)
 452                         return;
 453                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
 454                                 !setup->wLength;
 455         } else {
 456                 is_out = usb_endpoint_dir_out(&ep->desc);
 457         }
 458
 459         /* enforce simple/standard policy */
 460         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
 461                    URB_DIR_MASK | URB_FREE_BUFFER);
 462         switch (xfertype) {
 463         case USB_ENDPOINT_XFER_BULK:
 464                 if (is_out)
 465                         allowed |= URB_ZERO_PACKET;
 466                 /* FALLTHROUGH */
 467         case USB_ENDPOINT_XFER_CONTROL:
 468                 allowed |= URB_NO_FSBR; /* only affects UHCI */
 469                 /* FALLTHROUGH */
 470         default:                        /* all non-iso endpoints */
 471                 if (!is_out)
 472                         allowed |= URB_SHORT_NOT_OK;
 473                 break;
 474         case USB_ENDPOINT_XFER_ISOC:
 475                 allowed |= URB_ISO_ASAP;
 476                 break;
 477         }
 478         urb->transfer_flags &= allowed;
 479 }
 480
 481 static void stub_recv_cmd_submit(struct stub_device *sdev,
 482                                  struct usbip_header *pdu)
 483 {
 484         int ret;
 485         struct stub_priv *priv;
 486         struct usbip_device *ud = &sdev->ud;
 487         struct usb_device *udev = sdev->udev;
 488         int pipe = get_pipe(sdev, pdu->base.ep, pdu->base.direction);
 489
 490
 491         priv = stub_priv_alloc(sdev, pdu);
 492         if (!priv)
 493                 return;
 494
 495         /* setup a urb */
 496         if (usb_pipeisoc(pipe))
 497                 priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
 498                                                                 GFP_KERNEL);
 499         else
 500                 priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 501
 502         if (!priv->urb) {
 503                 dev_err(&sdev->interface->dev, "malloc urb\n");
 504                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 505                 return;
 506         }
 507
 508         /* set priv->urb->transfer_buffer */
 509         if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
 510                 priv->urb->transfer_buffer =
 511                         kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
 512                                                                 GFP_KERNEL);
 513                 if (!priv->urb->transfer_buffer) {
 514                         dev_err(&sdev->interface->dev, "malloc x_buff\n");
 515                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 516                         return;
 517                 }
 518         }
 519
 520         /* set priv->urb->setup_packet */
 521         priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
 522                                           GFP_KERNEL);
 523         if (!priv->urb->setup_packet) {
 524                 dev_err(&sdev->interface->dev, "allocate setup_packet\n");
 525                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 526                 return;
 527         }
 528
 529         /* set other members from the base header of pdu */
 530         priv->urb->context                = (void *) priv;
 531         priv->urb->dev                    = udev;
 532         priv->urb->pipe                   = pipe;
 533         priv->urb->complete               = stub_complete;
 534
 535         usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
 536
 537
 538         if (usbip_recv_xbuff(ud, priv->urb) < 0)
 539                 return;
 540
 541         if (usbip_recv_iso(ud, priv->urb) < 0)
 542                 return;
 543
 544         /* no need to submit an intercepted request, but harmless? */
 545         tweak_special_requests(priv->urb);
 546
 547         masking_bogus_flags(priv->urb);
 548         /* urb is now ready to submit */
 549         ret = usb_submit_urb(priv->urb, GFP_KERNEL);
 550
 551         if (ret == 0)
 552                 usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 553                                                         pdu->base.seqnum);
 554         else {
 555                 dev_err(&sdev->interface->dev, "submit_urb error, %d\n", ret);
 556                 usbip_dump_header(pdu);
 557                 usbip_dump_urb(priv->urb);
 558
 559                 /*
 560                  * Pessimistic.
 561                  * This connection will be discarded.
 562                  */
 563                 usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 564         }
 565
 566         usbip_dbg_stub_rx("Leave\n");
 567         return;
 568 }
 569
 570 /* recv a pdu */
 571 static void stub_rx_pdu(struct usbip_device *ud)
 572 {
 573         int ret;
 574         struct usbip_header pdu;
 575         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 576         struct device *dev = &sdev->interface->dev;
 577
 578         usbip_dbg_stub_rx("Enter\n");
 579
 580         memset(&pdu, 0, sizeof(pdu));
 581
 582         /* 1. receive a pdu header */
 583         ret = usbip_xmit(0, ud->tcp_socket, (char *) &pdu, sizeof(pdu), 0);
 584         if (ret != sizeof(pdu)) {
 585                 dev_err(dev, "recv a header, %d\n", ret);
 586                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 587                 return;
 588         }
 589
 590         usbip_header_correct_endian(&pdu, 0);
 591
 592         if (usbip_dbg_flag_stub_rx)
 593                 usbip_dump_header(&pdu);
 594
 595         if (!valid_request(sdev, &pdu)) {
 596                 dev_err(dev, "recv invalid request\n");
 597                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 598                 return;
 599         }
 600
 601         switch (pdu.base.command) {
 602         case USBIP_CMD_UNLINK:
 603                 stub_recv_cmd_unlink(sdev, &pdu);
 604                 break;
 605
 606         case USBIP_CMD_SUBMIT:
 607                 stub_recv_cmd_submit(sdev, &pdu);
 608                 break;
 609
 610         default:
 611                 /* NOTREACHED */
 612                 dev_err(dev, "unknown pdu\n");
 613                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 614                 return;
 615         }
 616
 617 }
 618
 619 void stub_rx_loop(struct usbip_task *ut)
 620 {
 621         struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_rx);
 622
 623         while (1) {
 624                 if (signal_pending(current)) {
 625                         usbip_dbg_stub_rx("signal caught!\n");
 626                         break;
 627                 }
 628
 629                 if (usbip_event_happened(ud))
 630                         break;
 631
 632                 stub_rx_pdu(ud);
 633         }
 634 }