drivers/usb/usbip/usbip_common.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2003-2008 Takahiro Hirofuchi
   4  * Copyright (C) 2015-2016 Samsung Electronics
   5  *               Krzysztof Opasiak <k.opasiak@samsung.com>
   6  */
   7
   8 #include <asm/byteorder.h>
   9 #include <linux/file.h>
  10 #include <linux/fs.h>
  11 #include <linux/kernel.h>
  12 #include <linux/slab.h>
  13 #include <linux/stat.h>
  14 #include <linux/module.h>
  15 #include <linux/moduleparam.h>
  16 #include <net/sock.h>
  17
  18 #include "usbip_common.h"
  19
  20 #define DRIVER_AUTHOR "Takahiro Hirofuchi <hirofuchi@users.sourceforge.net>"
  21 #define DRIVER_DESC "USB/IP Core"
  22
  23 #ifdef CONFIG_USBIP_DEBUG
  24 unsigned long usbip_debug_flag = 0xffffffff;
  25 #else
  26 unsigned long usbip_debug_flag;
  27 #endif
  28 EXPORT_SYMBOL_GPL(usbip_debug_flag);
  29 module_param(usbip_debug_flag, ulong, S_IRUGO|S_IWUSR);
  30 MODULE_PARM_DESC(usbip_debug_flag, "debug flags (defined in usbip_common.h)");
  31
  32 /* FIXME */
  33 struct device_attribute dev_attr_usbip_debug;
  34 EXPORT_SYMBOL_GPL(dev_attr_usbip_debug);
  35
  36 static ssize_t usbip_debug_show(struct device *dev,
  37                                 struct device_attribute *attr, char *buf)
  38 {
  39         return sprintf(buf, "%lx\n", usbip_debug_flag);
  40 }
  41
  42 static ssize_t usbip_debug_store(struct device *dev,
  43                                  struct device_attribute *attr, const char *buf,
  44                                  size_t count)
  45 {
  46         if (sscanf(buf, "%lx", &usbip_debug_flag) != 1)
  47                 return -EINVAL;
  48         return count;
  49 }
  50 DEVICE_ATTR_RW(usbip_debug);
  51
  52 static void usbip_dump_buffer(char *buff, int bufflen)
  53 {
  54         print_hex_dump(KERN_DEBUG, "usbip-core", DUMP_PREFIX_OFFSET, 16, 4,
  55                        buff, bufflen, false);
  56 }
  57
  58 static void usbip_dump_pipe(unsigned int p)
  59 {
  60         unsigned char type = usb_pipetype(p);
  61         unsigned char ep   = usb_pipeendpoint(p);
  62         unsigned char dev  = usb_pipedevice(p);
  63         unsigned char dir  = usb_pipein(p);
  64
  65         pr_debug("dev(%d) ep(%d) [%s] ", dev, ep, dir ? "IN" : "OUT");
  66
  67         switch (type) {
  68         case PIPE_ISOCHRONOUS:
  69                 pr_debug("ISO\n");
  70                 break;
  71         case PIPE_INTERRUPT:
  72                 pr_debug("INT\n");
  73                 break;
  74         case PIPE_CONTROL:
  75                 pr_debug("CTRL\n");
  76                 break;
  77         case PIPE_BULK:
  78                 pr_debug("BULK\n");
  79                 break;
  80         default:
  81                 pr_debug("ERR\n");
  82                 break;
  83         }
  84 }
  85
  86 static void usbip_dump_usb_device(struct usb_device *udev)
  87 {
  88         struct device *dev = &udev->dev;
  89         int i;
  90
  91         dev_dbg(dev, "       devnum(%d) devpath(%s) usb speed(%s)",
  92                 udev->devnum, udev->devpath, usb_speed_string(udev->speed));
  93
  94         pr_debug("tt %p, ttport %d\n", udev->tt, udev->ttport);
  95
  96         dev_dbg(dev, "                    ");
  97         for (i = 0; i < 16; i++)
  98                 pr_debug(" %2u", i);
  99         pr_debug("\n");
 100
 101         dev_dbg(dev, "       toggle0(IN) :");
 102         for (i = 0; i < 16; i++)
 103                 pr_debug(" %2u", (udev->toggle[0] & (1 << i)) ? 1 : 0);
 104         pr_debug("\n");
 105
 106         dev_dbg(dev, "       toggle1(OUT):");
 107         for (i = 0; i < 16; i++)
 108                 pr_debug(" %2u", (udev->toggle[1] & (1 << i)) ? 1 : 0);
 109         pr_debug("\n");
 110
 111         dev_dbg(dev, "       epmaxp_in   :");
 112         for (i = 0; i < 16; i++) {
 113                 if (udev->ep_in[i])
 114                         pr_debug(" %2u",
 115                             le16_to_cpu(udev->ep_in[i]->desc.wMaxPacketSize));
 116         }
 117         pr_debug("\n");
 118
 119         dev_dbg(dev, "       epmaxp_out  :");
 120         for (i = 0; i < 16; i++) {
 121                 if (udev->ep_out[i])
 122                         pr_debug(" %2u",
 123                             le16_to_cpu(udev->ep_out[i]->desc.wMaxPacketSize));
 124         }
 125         pr_debug("\n");
 126
 127         dev_dbg(dev, "parent %p, bus %p\n", udev->parent, udev->bus);
 128
 129         dev_dbg(dev,
 130                 "descriptor %p, config %p, actconfig %p, rawdescriptors %p\n",
 131                 &udev->descriptor, udev->config,
 132                 udev->actconfig, udev->rawdescriptors);
 133
 134         dev_dbg(dev, "have_langid %d, string_langid %d\n",
 135                 udev->have_langid, udev->string_langid);
 136
 137         dev_dbg(dev, "maxchild %d\n", udev->maxchild);
 138 }
 139
 140 static void usbip_dump_request_type(__u8 rt)
 141 {
 142         switch (rt & USB_RECIP_MASK) {
 143         case USB_RECIP_DEVICE:
 144                 pr_debug("DEVICE");
 145                 break;
 146         case USB_RECIP_INTERFACE:
 147                 pr_debug("INTERF");
 148                 break;
 149         case USB_RECIP_ENDPOINT:
 150                 pr_debug("ENDPOI");
 151                 break;
 152         case USB_RECIP_OTHER:
 153                 pr_debug("OTHER ");
 154                 break;
 155         default:
 156                 pr_debug("------");
 157                 break;
 158         }
 159 }
 160
 161 static void usbip_dump_usb_ctrlrequest(struct usb_ctrlrequest *cmd)
 162 {
 163         if (!cmd) {
 164                 pr_debug("       : null pointer\n");
 165                 return;
 166         }
 167
 168         pr_debug("       ");
 169         pr_debug("bRequestType(%02X) bRequest(%02X) wValue(%04X) wIndex(%04X) wLength(%04X) ",
 170                  cmd->bRequestType, cmd->bRequest,
 171                  cmd->wValue, cmd->wIndex, cmd->wLength);
 172         pr_debug("\n       ");
 173
 174         if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
 175                 pr_debug("STANDARD ");
 176                 switch (cmd->bRequest) {
 177                 case USB_REQ_GET_STATUS:
 178                         pr_debug("GET_STATUS\n");
 179                         break;
 180                 case USB_REQ_CLEAR_FEATURE:
 181                         pr_debug("CLEAR_FEAT\n");
 182                         break;
 183                 case USB_REQ_SET_FEATURE:
 184                         pr_debug("SET_FEAT\n");
 185                         break;
 186                 case USB_REQ_SET_ADDRESS:
 187                         pr_debug("SET_ADDRRS\n");
 188                         break;
 189                 case USB_REQ_GET_DESCRIPTOR:
 190                         pr_debug("GET_DESCRI\n");
 191                         break;
 192                 case USB_REQ_SET_DESCRIPTOR:
 193                         pr_debug("SET_DESCRI\n");
 194                         break;
 195                 case USB_REQ_GET_CONFIGURATION:
 196                         pr_debug("GET_CONFIG\n");
 197                         break;
 198                 case USB_REQ_SET_CONFIGURATION:
 199                         pr_debug("SET_CONFIG\n");
 200                         break;
 201                 case USB_REQ_GET_INTERFACE:
 202                         pr_debug("GET_INTERF\n");
 203                         break;
 204                 case USB_REQ_SET_INTERFACE:
 205                         pr_debug("SET_INTERF\n");
 206                         break;
 207                 case USB_REQ_SYNCH_FRAME:
 208                         pr_debug("SYNC_FRAME\n");
 209                         break;
 210                 default:
 211                         pr_debug("REQ(%02X)\n", cmd->bRequest);
 212                         break;
 213                 }
 214                 usbip_dump_request_type(cmd->bRequestType);
 215         } else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS) {
 216                 pr_debug("CLASS\n");
 217         } else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_VENDOR) {
 218                 pr_debug("VENDOR\n");
 219         } else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_RESERVED) {
 220                 pr_debug("RESERVED\n");
 221         }
 222 }
 223
 224 void usbip_dump_urb(struct urb *urb)
 225 {
 226         struct device *dev;
 227
 228         if (!urb) {
 229                 pr_debug("urb: null pointer!!\n");
 230                 return;
 231         }
 232
 233         if (!urb->dev) {
 234                 pr_debug("urb->dev: null pointer!!\n");
 235                 return;
 236         }
 237
 238         dev = &urb->dev->dev;
 239
 240         dev_dbg(dev, "   urb                   :%p\n", urb);
 241         dev_dbg(dev, "   dev                   :%p\n", urb->dev);
 242
 243         usbip_dump_usb_device(urb->dev);
 244
 245         dev_dbg(dev, "   pipe                  :%08x ", urb->pipe);
 246
 247         usbip_dump_pipe(urb->pipe);
 248
 249         dev_dbg(dev, "   status                :%d\n", urb->status);
 250         dev_dbg(dev, "   transfer_flags        :%08X\n", urb->transfer_flags);
 251         dev_dbg(dev, "   transfer_buffer       :%p\n", urb->transfer_buffer);
 252         dev_dbg(dev, "   transfer_buffer_length:%d\n",
 253                                                 urb->transfer_buffer_length);
 254         dev_dbg(dev, "   actual_length         :%d\n", urb->actual_length);
 255         dev_dbg(dev, "   setup_packet          :%p\n", urb->setup_packet);
 256
 257         if (urb->setup_packet && usb_pipetype(urb->pipe) == PIPE_CONTROL)
 258                 usbip_dump_usb_ctrlrequest(
 259                         (struct usb_ctrlrequest *)urb->setup_packet);
 260
 261         dev_dbg(dev, "   start_frame           :%d\n", urb->start_frame);
 262         dev_dbg(dev, "   number_of_packets     :%d\n", urb->number_of_packets);
 263         dev_dbg(dev, "   interval              :%d\n", urb->interval);
 264         dev_dbg(dev, "   error_count           :%d\n", urb->error_count);
 265         dev_dbg(dev, "   context               :%p\n", urb->context);
 266         dev_dbg(dev, "   complete              :%p\n", urb->complete);
 267 }
 268 EXPORT_SYMBOL_GPL(usbip_dump_urb);
 269
 270 void usbip_dump_header(struct usbip_header *pdu)
 271 {
 272         pr_debug("BASE: cmd %u seq %u devid %u dir %u ep %u\n",
 273                  pdu->base.command,
 274                  pdu->base.seqnum,
 275                  pdu->base.devid,
 276                  pdu->base.direction,
 277                  pdu->base.ep);
 278
 279         switch (pdu->base.command) {
 280         case USBIP_CMD_SUBMIT:
 281                 pr_debug("USBIP_CMD_SUBMIT: x_flags %u x_len %u sf %u #p %d iv %d\n",
 282                          pdu->u.cmd_submit.transfer_flags,
 283                          pdu->u.cmd_submit.transfer_buffer_length,
 284                          pdu->u.cmd_submit.start_frame,
 285                          pdu->u.cmd_submit.number_of_packets,
 286                          pdu->u.cmd_submit.interval);
 287                 break;
 288         case USBIP_CMD_UNLINK:
 289                 pr_debug("USBIP_CMD_UNLINK: seq %u\n",
 290                          pdu->u.cmd_unlink.seqnum);
 291                 break;
 292         case USBIP_RET_SUBMIT:
 293                 pr_debug("USBIP_RET_SUBMIT: st %d al %u sf %d #p %d ec %d\n",
 294                          pdu->u.ret_submit.status,
 295                          pdu->u.ret_submit.actual_length,
 296                          pdu->u.ret_submit.start_frame,
 297                          pdu->u.ret_submit.number_of_packets,
 298                          pdu->u.ret_submit.error_count);
 299                 break;
 300         case USBIP_RET_UNLINK:
 301                 pr_debug("USBIP_RET_UNLINK: status %d\n",
 302                          pdu->u.ret_unlink.status);
 303                 break;
 304         default:
 305                 /* NOT REACHED */
 306                 pr_err("unknown command\n");
 307                 break;
 308         }
 309 }
 310 EXPORT_SYMBOL_GPL(usbip_dump_header);
 311
 312 /* Receive data over TCP/IP. */
 313 int usbip_recv(struct socket *sock, void *buf, int size)
 314 {
 315         int result;
 316         struct kvec iov = {.iov_base = buf, .iov_len = size};
 317         struct msghdr msg = {.msg_flags = MSG_NOSIGNAL};
 318         int total = 0;
 319
 320         if (!sock || !buf || !size)
 321                 return -EINVAL;
 322
 323         iov_iter_kvec(&msg.msg_iter, READ|ITER_KVEC, &iov, 1, size);
 324
 325         usbip_dbg_xmit("enter\n");
 326
 327         do {
 328                 sock->sk->sk_allocation = GFP_NOIO;
 329
 330                 result = sock_recvmsg(sock, &msg, MSG_WAITALL);
 331                 if (result <= 0)
 332                         goto err;
 333
 334                 total += result;
 335         } while (msg_data_left(&msg));
 336
 337         if (usbip_dbg_flag_xmit) {
 338                 if (!in_interrupt())
 339                         pr_debug("%-10s:", current->comm);
 340                 else
 341                         pr_debug("interrupt  :");
 342
 343                 pr_debug("receiving....\n");
 344                 usbip_dump_buffer(buf, size);
 345                 pr_debug("received, osize %d ret %d size %zd total %d\n",
 346                          size, result, msg_data_left(&msg), total);
 347         }
 348
 349         return total;
 350
 351 err:
 352         return result;
 353 }
 354 EXPORT_SYMBOL_GPL(usbip_recv);
 355
 356 /* there may be more cases to tweak the flags. */
 357 static unsigned int tweak_transfer_flags(unsigned int flags)
 358 {
 359         flags &= ~URB_NO_TRANSFER_DMA_MAP;
 360         return flags;
 361 }
 362
 363 static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,
 364                                   int pack)
 365 {
 366         struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;
 367
 368         /*
 369          * Some members are not still implemented in usbip. I hope this issue
 370          * will be discussed when usbip is ported to other operating systems.
 371          */
 372         if (pack) {
 373                 spdu->transfer_flags =
 374                         tweak_transfer_flags(urb->transfer_flags);
 375                 spdu->transfer_buffer_length    = urb->transfer_buffer_length;
 376                 spdu->start_frame               = urb->start_frame;
 377                 spdu->number_of_packets         = urb->number_of_packets;
 378                 spdu->interval                  = urb->interval;
 379         } else  {
 380                 urb->transfer_flags         = spdu->transfer_flags;
 381                 urb->transfer_buffer_length = spdu->transfer_buffer_length;
 382                 urb->start_frame            = spdu->start_frame;
 383                 urb->number_of_packets      = spdu->number_of_packets;
 384                 urb->interval               = spdu->interval;
 385         }
 386 }
 387
 388 static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
 389                                   int pack)
 390 {
 391         struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;
 392
 393         if (pack) {
 394                 rpdu->status            = urb->status;
 395                 rpdu->actual_length     = urb->actual_length;
 396                 rpdu->start_frame       = urb->start_frame;
 397                 rpdu->number_of_packets = urb->number_of_packets;
 398                 rpdu->error_count       = urb->error_count;
 399         } else {
 400                 urb->status             = rpdu->status;
 401                 urb->actual_length      = rpdu->actual_length;
 402                 urb->start_frame        = rpdu->start_frame;
 403                 urb->number_of_packets = rpdu->number_of_packets;
 404                 urb->error_count        = rpdu->error_count;
 405         }
 406 }
 407
 408 void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
 409                     int pack)
 410 {
 411         switch (cmd) {
 412         case USBIP_CMD_SUBMIT:
 413                 usbip_pack_cmd_submit(pdu, urb, pack);
 414                 break;
 415         case USBIP_RET_SUBMIT:
 416                 usbip_pack_ret_submit(pdu, urb, pack);
 417                 break;
 418         default:
 419                 /* NOT REACHED */
 420                 pr_err("unknown command\n");
 421                 break;
 422         }
 423 }
 424 EXPORT_SYMBOL_GPL(usbip_pack_pdu);
 425
 426 static void correct_endian_basic(struct usbip_header_basic *base, int send)
 427 {
 428         if (send) {
 429                 base->command   = cpu_to_be32(base->command);
 430                 base->seqnum    = cpu_to_be32(base->seqnum);
 431                 base->devid     = cpu_to_be32(base->devid);
 432                 base->direction = cpu_to_be32(base->direction);
 433                 base->ep        = cpu_to_be32(base->ep);
 434         } else {
 435                 base->command   = be32_to_cpu(base->command);
 436                 base->seqnum    = be32_to_cpu(base->seqnum);
 437                 base->devid     = be32_to_cpu(base->devid);
 438                 base->direction = be32_to_cpu(base->direction);
 439                 base->ep        = be32_to_cpu(base->ep);
 440         }
 441 }
 442
 443 static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu,
 444                                       int send)
 445 {
 446         if (send) {
 447                 pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);
 448
 449                 cpu_to_be32s(&pdu->transfer_buffer_length);
 450                 cpu_to_be32s(&pdu->start_frame);
 451                 cpu_to_be32s(&pdu->number_of_packets);
 452                 cpu_to_be32s(&pdu->interval);
 453         } else {
 454                 pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);
 455
 456                 be32_to_cpus(&pdu->transfer_buffer_length);
 457                 be32_to_cpus(&pdu->start_frame);
 458                 be32_to_cpus(&pdu->number_of_packets);
 459                 be32_to_cpus(&pdu->interval);
 460         }
 461 }
 462
 463 static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu,
 464                                       int send)
 465 {
 466         if (send) {
 467                 cpu_to_be32s(&pdu->status);
 468                 cpu_to_be32s(&pdu->actual_length);
 469                 cpu_to_be32s(&pdu->start_frame);
 470                 cpu_to_be32s(&pdu->number_of_packets);
 471                 cpu_to_be32s(&pdu->error_count);
 472         } else {
 473                 be32_to_cpus(&pdu->status);
 474                 be32_to_cpus(&pdu->actual_length);
 475                 be32_to_cpus(&pdu->start_frame);
 476                 be32_to_cpus(&pdu->number_of_packets);
 477                 be32_to_cpus(&pdu->error_count);
 478         }
 479 }
 480
 481 static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu,
 482                                       int send)
 483 {
 484         if (send)
 485                 pdu->seqnum = cpu_to_be32(pdu->seqnum);
 486         else
 487                 pdu->seqnum = be32_to_cpu(pdu->seqnum);
 488 }
 489
 490 static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu,
 491                                       int send)
 492 {
 493         if (send)
 494                 cpu_to_be32s(&pdu->status);
 495         else
 496                 be32_to_cpus(&pdu->status);
 497 }
 498
 499 void usbip_header_correct_endian(struct usbip_header *pdu, int send)
 500 {
 501         __u32 cmd = 0;
 502
 503         if (send)
 504                 cmd = pdu->base.command;
 505
 506         correct_endian_basic(&pdu->base, send);
 507
 508         if (!send)
 509                 cmd = pdu->base.command;
 510
 511         switch (cmd) {
 512         case USBIP_CMD_SUBMIT:
 513                 correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
 514                 break;
 515         case USBIP_RET_SUBMIT:
 516                 correct_endian_ret_submit(&pdu->u.ret_submit, send);
 517                 break;
 518         case USBIP_CMD_UNLINK:
 519                 correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
 520                 break;
 521         case USBIP_RET_UNLINK:
 522                 correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
 523                 break;
 524         default:
 525                 /* NOT REACHED */
 526                 pr_err("unknown command\n");
 527                 break;
 528         }
 529 }
 530 EXPORT_SYMBOL_GPL(usbip_header_correct_endian);
 531
 532 static void usbip_iso_packet_correct_endian(
 533                 struct usbip_iso_packet_descriptor *iso, int send)
 534 {
 535         /* does not need all members. but copy all simply. */
 536         if (send) {
 537                 iso->offset     = cpu_to_be32(iso->offset);
 538                 iso->length     = cpu_to_be32(iso->length);
 539                 iso->status     = cpu_to_be32(iso->status);
 540                 iso->actual_length = cpu_to_be32(iso->actual_length);
 541         } else {
 542                 iso->offset     = be32_to_cpu(iso->offset);
 543                 iso->length     = be32_to_cpu(iso->length);
 544                 iso->status     = be32_to_cpu(iso->status);
 545                 iso->actual_length = be32_to_cpu(iso->actual_length);
 546         }
 547 }
 548
 549 static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
 550                            struct usb_iso_packet_descriptor *uiso, int pack)
 551 {
 552         if (pack) {
 553                 iso->offset             = uiso->offset;
 554                 iso->length             = uiso->length;
 555                 iso->status             = uiso->status;
 556                 iso->actual_length      = uiso->actual_length;
 557         } else {
 558                 uiso->offset            = iso->offset;
 559                 uiso->length            = iso->length;
 560                 uiso->status            = iso->status;
 561                 uiso->actual_length     = iso->actual_length;
 562         }
 563 }
 564
 565 /* must free buffer */
 566 struct usbip_iso_packet_descriptor*
 567 usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
 568 {
 569         struct usbip_iso_packet_descriptor *iso;
 570         int np = urb->number_of_packets;
 571         ssize_t size = np * sizeof(*iso);
 572         int i;
 573
 574         iso = kzalloc(size, GFP_KERNEL);
 575         if (!iso)
 576                 return NULL;
 577
 578         for (i = 0; i < np; i++) {
 579                 usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 1);
 580                 usbip_iso_packet_correct_endian(&iso[i], 1);
 581         }
 582
 583         *bufflen = size;
 584
 585         return iso;
 586 }
 587 EXPORT_SYMBOL_GPL(usbip_alloc_iso_desc_pdu);
 588
 589 /* some members of urb must be substituted before. */
 590 int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
 591 {
 592         void *buff;
 593         struct usbip_iso_packet_descriptor *iso;
 594         int np = urb->number_of_packets;
 595         int size = np * sizeof(*iso);
 596         int i;
 597         int ret;
 598         int total_length = 0;
 599
 600         if (!usb_pipeisoc(urb->pipe))
 601                 return 0;
 602
 603         /* my Bluetooth dongle gets ISO URBs which are np = 0 */
 604         if (np == 0)
 605                 return 0;
 606
 607         buff = kzalloc(size, GFP_KERNEL);
 608         if (!buff)
 609                 return -ENOMEM;
 610
 611         ret = usbip_recv(ud->tcp_socket, buff, size);
 612         if (ret != size) {
 613                 dev_err(&urb->dev->dev, "recv iso_frame_descriptor, %d\n",
 614                         ret);
 615                 kfree(buff);
 616
 617                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
 618                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 619                 else
 620                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 621
 622                 return -EPIPE;
 623         }
 624
 625         iso = (struct usbip_iso_packet_descriptor *) buff;
 626         for (i = 0; i < np; i++) {
 627                 usbip_iso_packet_correct_endian(&iso[i], 0);
 628                 usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 0);
 629                 total_length += urb->iso_frame_desc[i].actual_length;
 630         }
 631
 632         kfree(buff);
 633
 634         if (total_length != urb->actual_length) {
 635                 dev_err(&urb->dev->dev,
 636                         "total length of iso packets %d not equal to actual length of buffer %d\n",
 637                         total_length, urb->actual_length);
 638
 639                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
 640                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 641                 else
 642                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 643
 644                 return -EPIPE;
 645         }
 646
 647         return ret;
 648 }
 649 EXPORT_SYMBOL_GPL(usbip_recv_iso);
 650
 651 /*
 652  * This functions restores the padding which was removed for optimizing
 653  * the bandwidth during transfer over tcp/ip
 654  *
 655  * buffer and iso packets need to be stored and be in propeper endian in urb
 656  * before calling this function
 657  */
 658 void usbip_pad_iso(struct usbip_device *ud, struct urb *urb)
 659 {
 660         int np = urb->number_of_packets;
 661         int i;
 662         int actualoffset = urb->actual_length;
 663
 664         if (!usb_pipeisoc(urb->pipe))
 665                 return;
 666
 667         /* if no packets or length of data is 0, then nothing to unpack */
 668         if (np == 0 || urb->actual_length == 0)
 669                 return;
 670
 671         /*
 672          * if actual_length is transfer_buffer_length then no padding is
 673          * present.
 674          */
 675         if (urb->actual_length == urb->transfer_buffer_length)
 676                 return;
 677
 678         /*
 679          * loop over all packets from last to first (to prevent overwriting
 680          * memory when padding) and move them into the proper place
 681          */
 682         for (i = np-1; i > 0; i--) {
 683                 actualoffset -= urb->iso_frame_desc[i].actual_length;
 684                 memmove(urb->transfer_buffer + urb->iso_frame_desc[i].offset,
 685                         urb->transfer_buffer + actualoffset,
 686                         urb->iso_frame_desc[i].actual_length);
 687         }
 688 }
 689 EXPORT_SYMBOL_GPL(usbip_pad_iso);
 690
 691 /* some members of urb must be substituted before. */
 692 int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
 693 {
 694         int ret;
 695         int size;
 696
 697         if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
 698                 /* the direction of urb must be OUT. */
 699                 if (usb_pipein(urb->pipe))
 700                         return 0;
 701
 702                 size = urb->transfer_buffer_length;
 703         } else {
 704                 /* the direction of urb must be IN. */
 705                 if (usb_pipeout(urb->pipe))
 706                         return 0;
 707
 708                 size = urb->actual_length;
 709         }
 710
 711         /* no need to recv xbuff */
 712         if (!(size > 0))
 713                 return 0;
 714
 715         if (size > urb->transfer_buffer_length) {
 716                 /* should not happen, probably malicious packet */
 717                 if (ud->side == USBIP_STUB) {
 718                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 719                         return 0;
 720                 } else {
 721                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 722                         return -EPIPE;
 723                 }
 724         }
 725
 726         ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
 727         if (ret != size) {
 728                 dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
 729                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
 730                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 731                 } else {
 732                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 733                         return -EPIPE;
 734                 }
 735         }
 736
 737         return ret;
 738 }
 739 EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
 740
 741 static int __init usbip_core_init(void)
 742 {
 743         int ret;
 744
 745         ret = usbip_init_eh();
 746         if (ret)
 747                 return ret;
 748
 749         return 0;
 750 }
 751
 752 static void __exit usbip_core_exit(void)
 753 {
 754         usbip_finish_eh();
 755         return;
 756 }
 757
 758 module_init(usbip_core_init);
 759 module_exit(usbip_core_exit);
 760
 761 MODULE_AUTHOR(DRIVER_AUTHOR);
 762 MODULE_DESCRIPTION(DRIVER_DESC);
 763 MODULE_LICENSE("GPL");