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