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