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|ITER_KVEC, &iov, 1, size);
 313
 314         usbip_dbg_xmit("enter\n");
 315
 316         do {
 317                 msg_data_left(&msg);
 318                 sock->sk->sk_allocation = GFP_NOIO;
 319
 320                 result = sock_recvmsg(sock, &msg, MSG_WAITALL);
 321                 if (result <= 0)
 322                         goto err;
 323
 324                 total += result;
 325         } while (msg_data_left(&msg));
 326
 327         if (usbip_dbg_flag_xmit) {
 328                 if (!in_interrupt())
 329                         pr_debug("%-10s:", current->comm);
 330                 else
 331                         pr_debug("interrupt  :");
 332
 333                 pr_debug("receiving....\n");
 334                 usbip_dump_buffer(buf, size);
 335                 pr_debug("received, osize %d ret %d size %zd total %d\n",
 336                          size, result, msg_data_left(&msg), total);
 337         }
 338
 339         return total;
 340
 341 err:
 342         return result;
 343 }
 344 EXPORT_SYMBOL_GPL(usbip_recv);
 345
 346 /* there may be more cases to tweak the flags. */
 347 static unsigned int tweak_transfer_flags(unsigned int flags)
 348 {
 349         flags &= ~URB_NO_TRANSFER_DMA_MAP;
 350         return flags;
 351 }
 352
 353 static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,
 354                                   int pack)
 355 {
 356         struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;
 357
 358         /*
 359          * Some members are not still implemented in usbip. I hope this issue
 360          * will be discussed when usbip is ported to other operating systems.
 361          */
 362         if (pack) {
 363                 spdu->transfer_flags =
 364                         tweak_transfer_flags(urb->transfer_flags);
 365                 spdu->transfer_buffer_length    = urb->transfer_buffer_length;
 366                 spdu->start_frame               = urb->start_frame;
 367                 spdu->number_of_packets         = urb->number_of_packets;
 368                 spdu->interval                  = urb->interval;
 369         } else  {
 370                 urb->transfer_flags         = spdu->transfer_flags;
 371                 urb->transfer_buffer_length = spdu->transfer_buffer_length;
 372                 urb->start_frame            = spdu->start_frame;
 373                 urb->number_of_packets      = spdu->number_of_packets;
 374                 urb->interval               = spdu->interval;
 375         }
 376 }
 377
 378 static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
 379                                   int pack)
 380 {
 381         struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;
 382
 383         if (pack) {
 384                 rpdu->status            = urb->status;
 385                 rpdu->actual_length     = urb->actual_length;
 386                 rpdu->start_frame       = urb->start_frame;
 387                 rpdu->number_of_packets = urb->number_of_packets;
 388                 rpdu->error_count       = urb->error_count;
 389         } else {
 390                 urb->status             = rpdu->status;
 391                 urb->actual_length      = rpdu->actual_length;
 392                 urb->start_frame        = rpdu->start_frame;
 393                 urb->number_of_packets = rpdu->number_of_packets;
 394                 urb->error_count        = rpdu->error_count;
 395         }
 396 }
 397
 398 void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
 399                     int pack)
 400 {
 401         switch (cmd) {
 402         case USBIP_CMD_SUBMIT:
 403                 usbip_pack_cmd_submit(pdu, urb, pack);
 404                 break;
 405         case USBIP_RET_SUBMIT:
 406                 usbip_pack_ret_submit(pdu, urb, pack);
 407                 break;
 408         default:
 409                 /* NOT REACHED */
 410                 pr_err("unknown command\n");
 411                 break;
 412         }
 413 }
 414 EXPORT_SYMBOL_GPL(usbip_pack_pdu);
 415
 416 static void correct_endian_basic(struct usbip_header_basic *base, int send)
 417 {
 418         if (send) {
 419                 base->command   = cpu_to_be32(base->command);
 420                 base->seqnum    = cpu_to_be32(base->seqnum);
 421                 base->devid     = cpu_to_be32(base->devid);
 422                 base->direction = cpu_to_be32(base->direction);
 423                 base->ep        = cpu_to_be32(base->ep);
 424         } else {
 425                 base->command   = be32_to_cpu(base->command);
 426                 base->seqnum    = be32_to_cpu(base->seqnum);
 427                 base->devid     = be32_to_cpu(base->devid);
 428                 base->direction = be32_to_cpu(base->direction);
 429                 base->ep        = be32_to_cpu(base->ep);
 430         }
 431 }
 432
 433 static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu,
 434                                       int send)
 435 {
 436         if (send) {
 437                 pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);
 438
 439                 cpu_to_be32s(&pdu->transfer_buffer_length);
 440                 cpu_to_be32s(&pdu->start_frame);
 441                 cpu_to_be32s(&pdu->number_of_packets);
 442                 cpu_to_be32s(&pdu->interval);
 443         } else {
 444                 pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);
 445
 446                 be32_to_cpus(&pdu->transfer_buffer_length);
 447                 be32_to_cpus(&pdu->start_frame);
 448                 be32_to_cpus(&pdu->number_of_packets);
 449                 be32_to_cpus(&pdu->interval);
 450         }
 451 }
 452
 453 static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu,
 454                                       int send)
 455 {
 456         if (send) {
 457                 cpu_to_be32s(&pdu->status);
 458                 cpu_to_be32s(&pdu->actual_length);
 459                 cpu_to_be32s(&pdu->start_frame);
 460                 cpu_to_be32s(&pdu->number_of_packets);
 461                 cpu_to_be32s(&pdu->error_count);
 462         } else {
 463                 be32_to_cpus(&pdu->status);
 464                 be32_to_cpus(&pdu->actual_length);
 465                 be32_to_cpus(&pdu->start_frame);
 466                 be32_to_cpus(&pdu->number_of_packets);
 467                 be32_to_cpus(&pdu->error_count);
 468         }
 469 }
 470
 471 static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu,
 472                                       int send)
 473 {
 474         if (send)
 475                 pdu->seqnum = cpu_to_be32(pdu->seqnum);
 476         else
 477                 pdu->seqnum = be32_to_cpu(pdu->seqnum);
 478 }
 479
 480 static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu,
 481                                       int send)
 482 {
 483         if (send)
 484                 cpu_to_be32s(&pdu->status);
 485         else
 486                 be32_to_cpus(&pdu->status);
 487 }
 488
 489 void usbip_header_correct_endian(struct usbip_header *pdu, int send)
 490 {
 491         __u32 cmd = 0;
 492
 493         if (send)
 494                 cmd = pdu->base.command;
 495
 496         correct_endian_basic(&pdu->base, send);
 497
 498         if (!send)
 499                 cmd = pdu->base.command;
 500
 501         switch (cmd) {
 502         case USBIP_CMD_SUBMIT:
 503                 correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
 504                 break;
 505         case USBIP_RET_SUBMIT:
 506                 correct_endian_ret_submit(&pdu->u.ret_submit, send);
 507                 break;
 508         case USBIP_CMD_UNLINK:
 509                 correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
 510                 break;
 511         case USBIP_RET_UNLINK:
 512                 correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
 513                 break;
 514         default:
 515                 /* NOT REACHED */
 516                 pr_err("unknown command\n");
 517                 break;
 518         }
 519 }
 520 EXPORT_SYMBOL_GPL(usbip_header_correct_endian);
 521
 522 static void usbip_iso_packet_correct_endian(
 523                 struct usbip_iso_packet_descriptor *iso, int send)
 524 {
 525         /* does not need all members. but copy all simply. */
 526         if (send) {
 527                 iso->offset     = cpu_to_be32(iso->offset);
 528                 iso->length     = cpu_to_be32(iso->length);
 529                 iso->status     = cpu_to_be32(iso->status);
 530                 iso->actual_length = cpu_to_be32(iso->actual_length);
 531         } else {
 532                 iso->offset     = be32_to_cpu(iso->offset);
 533                 iso->length     = be32_to_cpu(iso->length);
 534                 iso->status     = be32_to_cpu(iso->status);
 535                 iso->actual_length = be32_to_cpu(iso->actual_length);
 536         }
 537 }
 538
 539 static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
 540                            struct usb_iso_packet_descriptor *uiso, int pack)
 541 {
 542         if (pack) {
 543                 iso->offset             = uiso->offset;
 544                 iso->length             = uiso->length;
 545                 iso->status             = uiso->status;
 546                 iso->actual_length      = uiso->actual_length;
 547         } else {
 548                 uiso->offset            = iso->offset;
 549                 uiso->length            = iso->length;
 550                 uiso->status            = iso->status;
 551                 uiso->actual_length     = iso->actual_length;
 552         }
 553 }
 554
 555 /* must free buffer */
 556 struct usbip_iso_packet_descriptor*
 557 usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
 558 {
 559         struct usbip_iso_packet_descriptor *iso;
 560         int np = urb->number_of_packets;
 561         ssize_t size = np * sizeof(*iso);
 562         int i;
 563
 564         iso = kzalloc(size, GFP_KERNEL);
 565         if (!iso)
 566                 return NULL;
 567
 568         for (i = 0; i < np; i++) {
 569                 usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 1);
 570                 usbip_iso_packet_correct_endian(&iso[i], 1);
 571         }
 572
 573         *bufflen = size;
 574
 575         return iso;
 576 }
 577 EXPORT_SYMBOL_GPL(usbip_alloc_iso_desc_pdu);
 578
 579 /* some members of urb must be substituted before. */
 580 int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
 581 {
 582         void *buff;
 583         struct usbip_iso_packet_descriptor *iso;
 584         int np = urb->number_of_packets;
 585         int size = np * sizeof(*iso);
 586         int i;
 587         int ret;
 588         int total_length = 0;
 589
 590         if (!usb_pipeisoc(urb->pipe))
 591                 return 0;
 592
 593         /* my Bluetooth dongle gets ISO URBs which are np = 0 */
 594         if (np == 0)
 595                 return 0;
 596
 597         buff = kzalloc(size, GFP_KERNEL);
 598         if (!buff)
 599                 return -ENOMEM;
 600
 601         ret = usbip_recv(ud->tcp_socket, buff, size);
 602         if (ret != size) {
 603                 dev_err(&urb->dev->dev, "recv iso_frame_descriptor, %d\n",
 604                         ret);
 605                 kfree(buff);
 606
 607                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
 608                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 609                 else
 610                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 611
 612                 return -EPIPE;
 613         }
 614
 615         iso = (struct usbip_iso_packet_descriptor *) buff;
 616         for (i = 0; i < np; i++) {
 617                 usbip_iso_packet_correct_endian(&iso[i], 0);
 618                 usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 0);
 619                 total_length += urb->iso_frame_desc[i].actual_length;
 620         }
 621
 622         kfree(buff);
 623
 624         if (total_length != urb->actual_length) {
 625                 dev_err(&urb->dev->dev,
 626                         "total length of iso packets %d not equal to actual length of buffer %d\n",
 627                         total_length, urb->actual_length);
 628
 629                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
 630                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 631                 else
 632                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 633
 634                 return -EPIPE;
 635         }
 636
 637         return ret;
 638 }
 639 EXPORT_SYMBOL_GPL(usbip_recv_iso);
 640
 641 /*
 642  * This functions restores the padding which was removed for optimizing
 643  * the bandwidth during transfer over tcp/ip
 644  *
 645  * buffer and iso packets need to be stored and be in propeper endian in urb
 646  * before calling this function
 647  */
 648 void usbip_pad_iso(struct usbip_device *ud, struct urb *urb)
 649 {
 650         int np = urb->number_of_packets;
 651         int i;
 652         int actualoffset = urb->actual_length;
 653
 654         if (!usb_pipeisoc(urb->pipe))
 655                 return;
 656
 657         /* if no packets or length of data is 0, then nothing to unpack */
 658         if (np == 0 || urb->actual_length == 0)
 659                 return;
 660
 661         /*
 662          * if actual_length is transfer_buffer_length then no padding is
 663          * present.
 664          */
 665         if (urb->actual_length == urb->transfer_buffer_length)
 666                 return;
 667
 668         /*
 669          * loop over all packets from last to first (to prevent overwriting
 670          * memory when padding) and move them into the proper place
 671          */
 672         for (i = np-1; i > 0; i--) {
 673                 actualoffset -= urb->iso_frame_desc[i].actual_length;
 674                 memmove(urb->transfer_buffer + urb->iso_frame_desc[i].offset,
 675                         urb->transfer_buffer + actualoffset,
 676                         urb->iso_frame_desc[i].actual_length);
 677         }
 678 }
 679 EXPORT_SYMBOL_GPL(usbip_pad_iso);
 680
 681 /* some members of urb must be substituted before. */
 682 int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
 683 {
 684         int ret;
 685         int size;
 686
 687         if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
 688                 /* the direction of urb must be OUT. */
 689                 if (usb_pipein(urb->pipe))
 690                         return 0;
 691
 692                 size = urb->transfer_buffer_length;
 693         } else {
 694                 /* the direction of urb must be IN. */
 695                 if (usb_pipeout(urb->pipe))
 696                         return 0;
 697
 698                 size = urb->actual_length;
 699         }
 700
 701         /* no need to recv xbuff */
 702         if (!(size > 0))
 703                 return 0;
 704
 705         if (size > urb->transfer_buffer_length) {
 706                 /* should not happen, probably malicious packet */
 707                 if (ud->side == USBIP_STUB) {
 708                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 709                         return 0;
 710                 } else {
 711                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 712                         return -EPIPE;
 713                 }
 714         }
 715
 716         ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
 717         if (ret != size) {
 718                 dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
 719                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
 720                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 721                 } else {
 722                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 723                         return -EPIPE;
 724                 }
 725         }
 726
 727         return ret;
 728 }
 729 EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
 730
 731 static int __init usbip_core_init(void)
 732 {
 733         int ret;
 734
 735         ret = usbip_init_eh();
 736         if (ret)
 737                 return ret;
 738
 739         return 0;
 740 }
 741
 742 static void __exit usbip_core_exit(void)
 743 {
 744         usbip_finish_eh();
 745         return;
 746 }
 747
 748 module_init(usbip_core_init);
 749 module_exit(usbip_core_exit);
 750
 751 MODULE_AUTHOR(DRIVER_AUTHOR);
 752 MODULE_DESCRIPTION(DRIVER_DESC);
 753 MODULE_LICENSE("GPL");