drivers/usb/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 #include <linux/scatterlist.h>
  25
  26 #include "usbip_common.h"
  27 #include "stub.h"
  28
  29 static int is_clear_halt_cmd(struct urb *urb)
  30 {
  31         struct usb_ctrlrequest *req;
  32
  33         req = (struct usb_ctrlrequest *) urb->setup_packet;
  34
  35          return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
  36                  (req->bRequestType == USB_RECIP_ENDPOINT) &&
  37                  (req->wValue == USB_ENDPOINT_HALT);
  38 }
  39
  40 static int is_set_interface_cmd(struct urb *urb)
  41 {
  42         struct usb_ctrlrequest *req;
  43
  44         req = (struct usb_ctrlrequest *) urb->setup_packet;
  45
  46         return (req->bRequest == USB_REQ_SET_INTERFACE) &&
  47                 (req->bRequestType == USB_RECIP_INTERFACE);
  48 }
  49
  50 static int is_set_configuration_cmd(struct urb *urb)
  51 {
  52         struct usb_ctrlrequest *req;
  53
  54         req = (struct usb_ctrlrequest *) urb->setup_packet;
  55
  56         return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
  57                 (req->bRequestType == USB_RECIP_DEVICE);
  58 }
  59
  60 static int is_reset_device_cmd(struct urb *urb)
  61 {
  62         struct usb_ctrlrequest *req;
  63         __u16 value;
  64         __u16 index;
  65
  66         req = (struct usb_ctrlrequest *) urb->setup_packet;
  67         value = le16_to_cpu(req->wValue);
  68         index = le16_to_cpu(req->wIndex);
  69
  70         if ((req->bRequest == USB_REQ_SET_FEATURE) &&
  71             (req->bRequestType == USB_RT_PORT) &&
  72             (value == USB_PORT_FEAT_RESET)) {
  73                 usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
  74                 return 1;
  75         } else
  76                 return 0;
  77 }
  78
  79 static int tweak_clear_halt_cmd(struct urb *urb)
  80 {
  81         struct usb_ctrlrequest *req;
  82         int target_endp;
  83         int target_dir;
  84         int target_pipe;
  85         int ret;
  86
  87         req = (struct usb_ctrlrequest *) urb->setup_packet;
  88
  89         /*
  90          * The stalled endpoint is specified in the wIndex value. The endpoint
  91          * of the urb is the target of this clear_halt request (i.e., control
  92          * endpoint).
  93          */
  94         target_endp = le16_to_cpu(req->wIndex) & 0x000f;
  95
  96         /* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
  97         target_dir = le16_to_cpu(req->wIndex) & 0x0080;
  98
  99         if (target_dir)
 100                 target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
 101         else
 102                 target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
 103
 104         ret = usb_clear_halt(urb->dev, target_pipe);
 105         if (ret < 0)
 106                 dev_err(&urb->dev->dev,
 107                         "usb_clear_halt error: devnum %d endp %d ret %d\n",
 108                         urb->dev->devnum, target_endp, ret);
 109         else
 110                 dev_info(&urb->dev->dev,
 111                          "usb_clear_halt done: devnum %d endp %d\n",
 112                          urb->dev->devnum, target_endp);
 113
 114         return ret;
 115 }
 116
 117 static int tweak_set_interface_cmd(struct urb *urb)
 118 {
 119         struct usb_ctrlrequest *req;
 120         __u16 alternate;
 121         __u16 interface;
 122         int ret;
 123
 124         req = (struct usb_ctrlrequest *) urb->setup_packet;
 125         alternate = le16_to_cpu(req->wValue);
 126         interface = le16_to_cpu(req->wIndex);
 127
 128         usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
 129                           interface, alternate);
 130
 131         ret = usb_set_interface(urb->dev, interface, alternate);
 132         if (ret < 0)
 133                 dev_err(&urb->dev->dev,
 134                         "usb_set_interface error: inf %u alt %u ret %d\n",
 135                         interface, alternate, ret);
 136         else
 137                 dev_info(&urb->dev->dev,
 138                         "usb_set_interface done: inf %u alt %u\n",
 139                         interface, alternate);
 140
 141         return ret;
 142 }
 143
 144 static int tweak_set_configuration_cmd(struct urb *urb)
 145 {
 146         struct stub_priv *priv = (struct stub_priv *) urb->context;
 147         struct stub_device *sdev = priv->sdev;
 148         struct usb_ctrlrequest *req;
 149         __u16 config;
 150         int err;
 151
 152         req = (struct usb_ctrlrequest *) urb->setup_packet;
 153         config = le16_to_cpu(req->wValue);
 154
 155         usb_lock_device(sdev->udev);
 156         err = usb_set_configuration(sdev->udev, config);
 157         usb_unlock_device(sdev->udev);
 158         if (err && err != -ENODEV)
 159                 dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
 160                         config, err);
 161         return 0;
 162 }
 163
 164 static int tweak_reset_device_cmd(struct urb *urb)
 165 {
 166         struct stub_priv *priv = (struct stub_priv *) urb->context;
 167         struct stub_device *sdev = priv->sdev;
 168
 169         dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
 170
 171         if (usb_lock_device_for_reset(sdev->udev, NULL) < 0) {
 172                 dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
 173                 return 0;
 174         }
 175         usb_reset_device(sdev->udev);
 176         usb_unlock_device(sdev->udev);
 177
 178         return 0;
 179 }
 180
 181 /*
 182  * clear_halt, set_interface, and set_configuration require special tricks.
 183  */
 184 static void tweak_special_requests(struct urb *urb)
 185 {
 186         if (!urb || !urb->setup_packet)
 187                 return;
 188
 189         if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
 190                 return;
 191
 192         if (is_clear_halt_cmd(urb))
 193                 /* tweak clear_halt */
 194                  tweak_clear_halt_cmd(urb);
 195
 196         else if (is_set_interface_cmd(urb))
 197                 /* tweak set_interface */
 198                 tweak_set_interface_cmd(urb);
 199
 200         else if (is_set_configuration_cmd(urb))
 201                 /* tweak set_configuration */
 202                 tweak_set_configuration_cmd(urb);
 203
 204         else if (is_reset_device_cmd(urb))
 205                 tweak_reset_device_cmd(urb);
 206         else
 207                 usbip_dbg_stub_rx("no need to tweak\n");
 208 }
 209
 210 /*
 211  * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
 212  * By unlinking the urb asynchronously, stub_rx can continuously
 213  * process coming urbs.  Even if the urb is unlinked, its completion
 214  * handler will be called and stub_tx will send a return pdu.
 215  *
 216  * See also comments about unlinking strategy in vhci_hcd.c.
 217  */
 218 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 219                                 struct usbip_header *pdu)
 220 {
 221         int ret, i;
 222         unsigned long flags;
 223         struct stub_priv *priv;
 224
 225         spin_lock_irqsave(&sdev->priv_lock, flags);
 226
 227         list_for_each_entry(priv, &sdev->priv_init, list) {
 228                 if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
 229                         continue;
 230
 231                 /*
 232                  * This matched urb is not completed yet (i.e., be in
 233                  * flight in usb hcd hardware/driver). Now we are
 234                  * cancelling it. The unlinking flag means that we are
 235                  * now not going to return the normal result pdu of a
 236                  * submission request, but going to return a result pdu
 237                  * of the unlink request.
 238                  */
 239                 priv->unlinking = 1;
 240
 241                 /*
 242                  * In the case that unlinking flag is on, prev->seqnum
 243                  * is changed from the seqnum of the cancelling urb to
 244                  * the seqnum of the unlink request. This will be used
 245                  * to make the result pdu of the unlink request.
 246                  */
 247                 priv->seqnum = pdu->base.seqnum;
 248
 249                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 250
 251                 /*
 252                  * usb_unlink_urb() is now out of spinlocking to avoid
 253                  * spinlock recursion since stub_complete() is
 254                  * sometimes called in this context but not in the
 255                  * interrupt context.  If stub_complete() is executed
 256                  * before we call usb_unlink_urb(), usb_unlink_urb()
 257                  * will return an error value. In this case, stub_tx
 258                  * will return the result pdu of this unlink request
 259                  * though submission is completed and actual unlinking
 260                  * is not executed. OK?
 261                  */
 262                 /* In the above case, urb->status is not -ECONNRESET,
 263                  * so a driver in a client host will know the failure
 264                  * of the unlink request ?
 265                  */
 266                 for (i = priv->completed_urbs; i < priv->num_urbs; i++) {
 267                         ret = usb_unlink_urb(priv->urbs[i]);
 268                         if (ret != -EINPROGRESS)
 269                                 dev_err(&priv->urbs[i]->dev->dev,
 270                                         "failed to unlink %d/%d urb of seqnum %lu, ret %d\n",
 271                                         i + 1, priv->num_urbs,
 272                                         priv->seqnum, ret);
 273                 }
 274                 return 0;
 275         }
 276
 277         usbip_dbg_stub_rx("seqnum %d is not pending\n",
 278                           pdu->u.cmd_unlink.seqnum);
 279
 280         /*
 281          * The urb of the unlink target is not found in priv_init queue. It was
 282          * already completed and its results is/was going to be sent by a
 283          * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
 284          * return the completeness of this unlink request to vhci_hcd.
 285          */
 286         stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
 287
 288         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 289
 290         return 0;
 291 }
 292
 293 static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
 294 {
 295         struct usbip_device *ud = &sdev->ud;
 296         int valid = 0;
 297
 298         if (pdu->base.devid == sdev->devid) {
 299                 spin_lock_irq(&ud->lock);
 300                 if (ud->status == SDEV_ST_USED) {
 301                         /* A request is valid. */
 302                         valid = 1;
 303                 }
 304                 spin_unlock_irq(&ud->lock);
 305         }
 306
 307         return valid;
 308 }
 309
 310 static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
 311                                          struct usbip_header *pdu)
 312 {
 313         struct stub_priv *priv;
 314         struct usbip_device *ud = &sdev->ud;
 315         unsigned long flags;
 316
 317         spin_lock_irqsave(&sdev->priv_lock, flags);
 318
 319         priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
 320         if (!priv) {
 321                 dev_err(&sdev->udev->dev, "alloc stub_priv\n");
 322                 spin_unlock_irqrestore(&sdev->priv_lock, flags);
 323                 usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 324                 return NULL;
 325         }
 326
 327         priv->seqnum = pdu->base.seqnum;
 328         priv->sdev = sdev;
 329
 330         /*
 331          * After a stub_priv is linked to a list_head,
 332          * our error handler can free allocated data.
 333          */
 334         list_add_tail(&priv->list, &sdev->priv_init);
 335
 336         spin_unlock_irqrestore(&sdev->priv_lock, flags);
 337
 338         return priv;
 339 }
 340
 341 static int get_pipe(struct stub_device *sdev, struct usbip_header *pdu)
 342 {
 343         struct usb_device *udev = sdev->udev;
 344         struct usb_host_endpoint *ep;
 345         struct usb_endpoint_descriptor *epd = NULL;
 346         int epnum = pdu->base.ep;
 347         int dir = pdu->base.direction;
 348
 349         if (epnum < 0 || epnum > 15)
 350                 goto err_ret;
 351
 352         if (dir == USBIP_DIR_IN)
 353                 ep = udev->ep_in[epnum & 0x7f];
 354         else
 355                 ep = udev->ep_out[epnum & 0x7f];
 356         if (!ep)
 357                 goto err_ret;
 358
 359         epd = &ep->desc;
 360
 361         if (usb_endpoint_xfer_control(epd)) {
 362                 if (dir == USBIP_DIR_OUT)
 363                         return usb_sndctrlpipe(udev, epnum);
 364                 else
 365                         return usb_rcvctrlpipe(udev, epnum);
 366         }
 367
 368         if (usb_endpoint_xfer_bulk(epd)) {
 369                 if (dir == USBIP_DIR_OUT)
 370                         return usb_sndbulkpipe(udev, epnum);
 371                 else
 372                         return usb_rcvbulkpipe(udev, epnum);
 373         }
 374
 375         if (usb_endpoint_xfer_int(epd)) {
 376                 if (dir == USBIP_DIR_OUT)
 377                         return usb_sndintpipe(udev, epnum);
 378                 else
 379                         return usb_rcvintpipe(udev, epnum);
 380         }
 381
 382         if (usb_endpoint_xfer_isoc(epd)) {
 383                 /* validate number of packets */
 384                 if (pdu->u.cmd_submit.number_of_packets < 0 ||
 385                     pdu->u.cmd_submit.number_of_packets >
 386                     USBIP_MAX_ISO_PACKETS) {
 387                         dev_err(&sdev->udev->dev,
 388                                 "CMD_SUBMIT: isoc invalid num packets %d\n",
 389                                 pdu->u.cmd_submit.number_of_packets);
 390                         return -1;
 391                 }
 392                 if (dir == USBIP_DIR_OUT)
 393                         return usb_sndisocpipe(udev, epnum);
 394                 else
 395                         return usb_rcvisocpipe(udev, epnum);
 396         }
 397
 398 err_ret:
 399         /* NOT REACHED */
 400         dev_err(&sdev->udev->dev, "CMD_SUBMIT: invalid epnum %d\n", epnum);
 401         return -1;
 402 }
 403
 404 static void masking_bogus_flags(struct urb *urb)
 405 {
 406         int                             xfertype;
 407         struct usb_device               *dev;
 408         struct usb_host_endpoint        *ep;
 409         int                             is_out;
 410         unsigned int    allowed;
 411
 412         if (!urb || urb->hcpriv || !urb->complete)
 413                 return;
 414         dev = urb->dev;
 415         if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
 416                 return;
 417
 418         ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
 419                 [usb_pipeendpoint(urb->pipe)];
 420         if (!ep)
 421                 return;
 422
 423         xfertype = usb_endpoint_type(&ep->desc);
 424         if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
 425                 struct usb_ctrlrequest *setup =
 426                         (struct usb_ctrlrequest *) urb->setup_packet;
 427
 428                 if (!setup)
 429                         return;
 430                 is_out = !(setup->bRequestType & USB_DIR_IN) ||
 431                         !setup->wLength;
 432         } else {
 433                 is_out = usb_endpoint_dir_out(&ep->desc);
 434         }
 435
 436         /* enforce simple/standard policy */
 437         allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
 438                    URB_DIR_MASK | URB_FREE_BUFFER);
 439         switch (xfertype) {
 440         case USB_ENDPOINT_XFER_BULK:
 441                 if (is_out)
 442                         allowed |= URB_ZERO_PACKET;
 443                 /* FALLTHROUGH */
 444         case USB_ENDPOINT_XFER_CONTROL:
 445                 allowed |= URB_NO_FSBR; /* only affects UHCI */
 446                 /* FALLTHROUGH */
 447         default:                        /* all non-iso endpoints */
 448                 if (!is_out)
 449                         allowed |= URB_SHORT_NOT_OK;
 450                 break;
 451         case USB_ENDPOINT_XFER_ISOC:
 452                 allowed |= URB_ISO_ASAP;
 453                 break;
 454         }
 455         urb->transfer_flags &= allowed;
 456 }
 457
 458 static int stub_recv_xbuff(struct usbip_device *ud, struct stub_priv *priv)
 459 {
 460         int ret;
 461         int i;
 462
 463         for (i = 0; i < priv->num_urbs; i++) {
 464                 ret = usbip_recv_xbuff(ud, priv->urbs[i]);
 465                 if (ret < 0)
 466                         break;
 467         }
 468
 469         return ret;
 470 }
 471
 472 static void stub_recv_cmd_submit(struct stub_device *sdev,
 473                                  struct usbip_header *pdu)
 474 {
 475         struct stub_priv *priv;
 476         struct usbip_device *ud = &sdev->ud;
 477         struct usb_device *udev = sdev->udev;
 478         struct scatterlist *sgl = NULL, *sg;
 479         void *buffer = NULL;
 480         unsigned long long buf_len;
 481         int nents;
 482         int num_urbs = 1;
 483         int pipe = get_pipe(sdev, pdu);
 484         int use_sg = pdu->u.cmd_submit.transfer_flags & URB_DMA_MAP_SG;
 485         int support_sg = 1;
 486         int np = 0;
 487         int ret, i;
 488
 489         if (pipe == -1)
 490                 return;
 491
 492         /*
 493          * Smatch reported the error case where use_sg is true and buf_len is 0.
 494          * In this case, It adds SDEV_EVENT_ERROR_MALLOC and stub_priv will be
 495          * released by stub event handler and connection will be shut down.
 496          */
 497         priv = stub_priv_alloc(sdev, pdu);
 498         if (!priv)
 499                 return;
 500
 501         buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
 502
 503         if (use_sg && !buf_len) {
 504                 dev_err(&udev->dev, "sg buffer with zero length\n");
 505                 goto err_malloc;
 506         }
 507
 508         /* allocate urb transfer buffer, if needed */
 509         if (buf_len) {
 510                 if (use_sg) {
 511                         sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
 512                         if (!sgl)
 513                                 goto err_malloc;
 514
 515                         /* Check if the server's HCD supports SG */
 516                         if (!udev->bus->sg_tablesize) {
 517                                 /*
 518                                  * If the server's HCD doesn't support SG, break
 519                                  * a single SG request into several URBs and map
 520                                  * each SG list entry to corresponding URB
 521                                  * buffer. The previously allocated SG list is
 522                                  * stored in priv->sgl (If the server's HCD
 523                                  * support SG, SG list is stored only in
 524                                  * urb->sg) and it is used as an indicator that
 525                                  * the server split single SG request into
 526                                  * several URBs. Later, priv->sgl is used by
 527                                  * stub_complete() and stub_send_ret_submit() to
 528                                  * reassemble the divied URBs.
 529                                  */
 530                                 support_sg = 0;
 531                                 num_urbs = nents;
 532                                 priv->completed_urbs = 0;
 533                                 pdu->u.cmd_submit.transfer_flags &=
 534                                                                 ~URB_DMA_MAP_SG;
 535                         }
 536                 } else {
 537                         buffer = kzalloc(buf_len, GFP_KERNEL);
 538                         if (!buffer)
 539                                 goto err_malloc;
 540                 }
 541         }
 542
 543         /* allocate urb array */
 544         priv->num_urbs = num_urbs;
 545         priv->urbs = kmalloc_array(num_urbs, sizeof(*priv->urbs), GFP_KERNEL);
 546         if (!priv->urbs)
 547                 goto err_urbs;
 548
 549         /* setup a urb */
 550         if (support_sg) {
 551                 if (usb_pipeisoc(pipe))
 552                         np = pdu->u.cmd_submit.number_of_packets;
 553
 554                 priv->urbs[0] = usb_alloc_urb(np, GFP_KERNEL);
 555                 if (!priv->urbs[0])
 556                         goto err_urb;
 557
 558                 if (buf_len) {
 559                         if (use_sg) {
 560                                 priv->urbs[0]->sg = sgl;
 561                                 priv->urbs[0]->num_sgs = nents;
 562                                 priv->urbs[0]->transfer_buffer = NULL;
 563                         } else {
 564                                 priv->urbs[0]->transfer_buffer = buffer;
 565                         }
 566                 }
 567
 568                 /* copy urb setup packet */
 569                 priv->urbs[0]->setup_packet = kmemdup(&pdu->u.cmd_submit.setup,
 570                                         8, GFP_KERNEL);
 571                 if (!priv->urbs[0]->setup_packet) {
 572                         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 573                         return;
 574                 }
 575
 576                 usbip_pack_pdu(pdu, priv->urbs[0], USBIP_CMD_SUBMIT, 0);
 577         } else {
 578                 for_each_sg(sgl, sg, nents, i) {
 579                         priv->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
 580                         /* The URBs which is previously allocated will be freed
 581                          * in stub_device_cleanup_urbs() if error occurs.
 582                          */
 583                         if (!priv->urbs[i])
 584                                 goto err_urb;
 585
 586                         usbip_pack_pdu(pdu, priv->urbs[i], USBIP_CMD_SUBMIT, 0);
 587                         priv->urbs[i]->transfer_buffer = sg_virt(sg);
 588                         priv->urbs[i]->transfer_buffer_length = sg->length;
 589                 }
 590                 priv->sgl = sgl;
 591         }
 592
 593         for (i = 0; i < num_urbs; i++) {
 594                 /* set other members from the base header of pdu */
 595                 priv->urbs[i]->context = (void *) priv;
 596                 priv->urbs[i]->dev = udev;
 597                 priv->urbs[i]->pipe = pipe;
 598                 priv->urbs[i]->complete = stub_complete;
 599
 600                 /* no need to submit an intercepted request, but harmless? */
 601                 tweak_special_requests(priv->urbs[i]);
 602
 603                 masking_bogus_flags(priv->urbs[i]);
 604         }
 605
 606         if (stub_recv_xbuff(ud, priv) < 0)
 607                 return;
 608
 609         if (usbip_recv_iso(ud, priv->urbs[0]) < 0)
 610                 return;
 611
 612         /* urb is now ready to submit */
 613         for (i = 0; i < priv->num_urbs; i++) {
 614                 ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
 615
 616                 if (ret == 0)
 617                         usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
 618                                         pdu->base.seqnum);
 619                 else {
 620                         dev_err(&udev->dev, "submit_urb error, %d\n", ret);
 621                         usbip_dump_header(pdu);
 622                         usbip_dump_urb(priv->urbs[i]);
 623
 624                         /*
 625                          * Pessimistic.
 626                          * This connection will be discarded.
 627                          */
 628                         usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
 629                         break;
 630                 }
 631         }
 632
 633         usbip_dbg_stub_rx("Leave\n");
 634         return;
 635
 636 err_urb:
 637         kfree(priv->urbs);
 638 err_urbs:
 639         kfree(buffer);
 640         sgl_free(sgl);
 641 err_malloc:
 642         usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 643 }
 644
 645 /* recv a pdu */
 646 static void stub_rx_pdu(struct usbip_device *ud)
 647 {
 648         int ret;
 649         struct usbip_header pdu;
 650         struct stub_device *sdev = container_of(ud, struct stub_device, ud);
 651         struct device *dev = &sdev->udev->dev;
 652
 653         usbip_dbg_stub_rx("Enter\n");
 654
 655         memset(&pdu, 0, sizeof(pdu));
 656
 657         /* receive a pdu header */
 658         ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
 659         if (ret != sizeof(pdu)) {
 660                 dev_err(dev, "recv a header, %d\n", ret);
 661                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 662                 return;
 663         }
 664
 665         usbip_header_correct_endian(&pdu, 0);
 666
 667         if (usbip_dbg_flag_stub_rx)
 668                 usbip_dump_header(&pdu);
 669
 670         if (!valid_request(sdev, &pdu)) {
 671                 dev_err(dev, "recv invalid request\n");
 672                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 673                 return;
 674         }
 675
 676         switch (pdu.base.command) {
 677         case USBIP_CMD_UNLINK:
 678                 stub_recv_cmd_unlink(sdev, &pdu);
 679                 break;
 680
 681         case USBIP_CMD_SUBMIT:
 682                 stub_recv_cmd_submit(sdev, &pdu);
 683                 break;
 684
 685         default:
 686                 /* NOTREACHED */
 687                 dev_err(dev, "unknown pdu\n");
 688                 usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 689                 break;
 690         }
 691 }
 692
 693 int stub_rx_loop(void *data)
 694 {
 695         struct usbip_device *ud = data;
 696
 697         while (!kthread_should_stop()) {
 698                 if (usbip_event_happened(ud))
 699                         break;
 700
 701                 stub_rx_pdu(ud);
 702         }
 703
 704         return 0;
 705 }