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         iov_iter_kvec(&msg.msg_iter, READ|ITER_KVEC, &iov, 1, size);
 321
 322         usbip_dbg_xmit("enter\n");
 323
 324         if (!sock || !buf || !size) {
 325                 pr_err("invalid arg, sock %p buff %p size %d\n", sock, buf,
 326                        size);
 327                 return -EINVAL;
 328         }
 329
 330         do {
 331                 int sz = msg_data_left(&msg);
 332                 sock->sk->sk_allocation = GFP_NOIO;
 333
 334                 result = sock_recvmsg(sock, &msg, MSG_WAITALL);
 335                 if (result <= 0) {
 336                         pr_debug("receive sock %p buf %p size %u ret %d total %d\n",
 337                                  sock, buf + total, sz, result, total);
 338                         goto err;
 339                 }
 340
 341                 total += result;
 342         } while (msg_data_left(&msg));
 343
 344         if (usbip_dbg_flag_xmit) {
 345                 if (!in_interrupt())
 346                         pr_debug("%-10s:", current->comm);
 347                 else
 348                         pr_debug("interrupt  :");
 349
 350                 pr_debug("receiving....\n");
 351                 usbip_dump_buffer(buf, size);
 352                 pr_debug("received, osize %d ret %d size %zd total %d\n",
 353                          size, result, msg_data_left(&msg), total);
 354         }
 355
 356         return total;
 357
 358 err:
 359         return result;
 360 }
 361 EXPORT_SYMBOL_GPL(usbip_recv);
 362
 363 /* there may be more cases to tweak the flags. */
 364 static unsigned int tweak_transfer_flags(unsigned int flags)
 365 {
 366         flags &= ~URB_NO_TRANSFER_DMA_MAP;
 367         return flags;
 368 }
 369
 370 static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,
 371                                   int pack)
 372 {
 373         struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;
 374
 375         /*
 376          * Some members are not still implemented in usbip. I hope this issue
 377          * will be discussed when usbip is ported to other operating systems.
 378          */
 379         if (pack) {
 380                 spdu->transfer_flags =
 381                         tweak_transfer_flags(urb->transfer_flags);
 382                 spdu->transfer_buffer_length    = urb->transfer_buffer_length;
 383                 spdu->start_frame               = urb->start_frame;
 384                 spdu->number_of_packets         = urb->number_of_packets;
 385                 spdu->interval                  = urb->interval;
 386         } else  {
 387                 urb->transfer_flags         = spdu->transfer_flags;
 388                 urb->transfer_buffer_length = spdu->transfer_buffer_length;
 389                 urb->start_frame            = spdu->start_frame;
 390                 urb->number_of_packets      = spdu->number_of_packets;
 391                 urb->interval               = spdu->interval;
 392         }
 393 }
 394
 395 static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
 396                                   int pack)
 397 {
 398         struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;
 399
 400         if (pack) {
 401                 rpdu->status            = urb->status;
 402                 rpdu->actual_length     = urb->actual_length;
 403                 rpdu->start_frame       = urb->start_frame;
 404                 rpdu->number_of_packets = urb->number_of_packets;
 405                 rpdu->error_count       = urb->error_count;
 406         } else {
 407                 urb->status             = rpdu->status;
 408                 urb->actual_length      = rpdu->actual_length;
 409                 urb->start_frame        = rpdu->start_frame;
 410                 urb->number_of_packets = rpdu->number_of_packets;
 411                 urb->error_count        = rpdu->error_count;
 412         }
 413 }
 414
 415 void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
 416                     int pack)
 417 {
 418         switch (cmd) {
 419         case USBIP_CMD_SUBMIT:
 420                 usbip_pack_cmd_submit(pdu, urb, pack);
 421                 break;
 422         case USBIP_RET_SUBMIT:
 423                 usbip_pack_ret_submit(pdu, urb, pack);
 424                 break;
 425         default:
 426                 /* NOT REACHED */
 427                 pr_err("unknown command\n");
 428                 break;
 429         }
 430 }
 431 EXPORT_SYMBOL_GPL(usbip_pack_pdu);
 432
 433 static void correct_endian_basic(struct usbip_header_basic *base, int send)
 434 {
 435         if (send) {
 436                 base->command   = cpu_to_be32(base->command);
 437                 base->seqnum    = cpu_to_be32(base->seqnum);
 438                 base->devid     = cpu_to_be32(base->devid);
 439                 base->direction = cpu_to_be32(base->direction);
 440                 base->ep        = cpu_to_be32(base->ep);
 441         } else {
 442                 base->command   = be32_to_cpu(base->command);
 443                 base->seqnum    = be32_to_cpu(base->seqnum);
 444                 base->devid     = be32_to_cpu(base->devid);
 445                 base->direction = be32_to_cpu(base->direction);
 446                 base->ep        = be32_to_cpu(base->ep);
 447         }
 448 }
 449
 450 static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu,
 451                                       int send)
 452 {
 453         if (send) {
 454                 pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);
 455
 456                 cpu_to_be32s(&pdu->transfer_buffer_length);
 457                 cpu_to_be32s(&pdu->start_frame);
 458                 cpu_to_be32s(&pdu->number_of_packets);
 459                 cpu_to_be32s(&pdu->interval);
 460         } else {
 461                 pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);
 462
 463                 be32_to_cpus(&pdu->transfer_buffer_length);
 464                 be32_to_cpus(&pdu->start_frame);
 465                 be32_to_cpus(&pdu->number_of_packets);
 466                 be32_to_cpus(&pdu->interval);
 467         }
 468 }
 469
 470 static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu,
 471                                       int send)
 472 {
 473         if (send) {
 474                 cpu_to_be32s(&pdu->status);
 475                 cpu_to_be32s(&pdu->actual_length);
 476                 cpu_to_be32s(&pdu->start_frame);
 477                 cpu_to_be32s(&pdu->number_of_packets);
 478                 cpu_to_be32s(&pdu->error_count);
 479         } else {
 480                 be32_to_cpus(&pdu->status);
 481                 be32_to_cpus(&pdu->actual_length);
 482                 be32_to_cpus(&pdu->start_frame);
 483                 be32_to_cpus(&pdu->number_of_packets);
 484                 be32_to_cpus(&pdu->error_count);
 485         }
 486 }
 487
 488 static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu,
 489                                       int send)
 490 {
 491         if (send)
 492                 pdu->seqnum = cpu_to_be32(pdu->seqnum);
 493         else
 494                 pdu->seqnum = be32_to_cpu(pdu->seqnum);
 495 }
 496
 497 static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu,
 498                                       int send)
 499 {
 500         if (send)
 501                 cpu_to_be32s(&pdu->status);
 502         else
 503                 be32_to_cpus(&pdu->status);
 504 }
 505
 506 void usbip_header_correct_endian(struct usbip_header *pdu, int send)
 507 {
 508         __u32 cmd = 0;
 509
 510         if (send)
 511                 cmd = pdu->base.command;
 512
 513         correct_endian_basic(&pdu->base, send);
 514
 515         if (!send)
 516                 cmd = pdu->base.command;
 517
 518         switch (cmd) {
 519         case USBIP_CMD_SUBMIT:
 520                 correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
 521                 break;
 522         case USBIP_RET_SUBMIT:
 523                 correct_endian_ret_submit(&pdu->u.ret_submit, send);
 524                 break;
 525         case USBIP_CMD_UNLINK:
 526                 correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
 527                 break;
 528         case USBIP_RET_UNLINK:
 529                 correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
 530                 break;
 531         default:
 532                 /* NOT REACHED */
 533                 pr_err("unknown command\n");
 534                 break;
 535         }
 536 }
 537 EXPORT_SYMBOL_GPL(usbip_header_correct_endian);
 538
 539 static void usbip_iso_packet_correct_endian(
 540                 struct usbip_iso_packet_descriptor *iso, int send)
 541 {
 542         /* does not need all members. but copy all simply. */
 543         if (send) {
 544                 iso->offset     = cpu_to_be32(iso->offset);
 545                 iso->length     = cpu_to_be32(iso->length);
 546                 iso->status     = cpu_to_be32(iso->status);
 547                 iso->actual_length = cpu_to_be32(iso->actual_length);
 548         } else {
 549                 iso->offset     = be32_to_cpu(iso->offset);
 550                 iso->length     = be32_to_cpu(iso->length);
 551                 iso->status     = be32_to_cpu(iso->status);
 552                 iso->actual_length = be32_to_cpu(iso->actual_length);
 553         }
 554 }
 555
 556 static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
 557                            struct usb_iso_packet_descriptor *uiso, int pack)
 558 {
 559         if (pack) {
 560                 iso->offset             = uiso->offset;
 561                 iso->length             = uiso->length;
 562                 iso->status             = uiso->status;
 563                 iso->actual_length      = uiso->actual_length;
 564         } else {
 565                 uiso->offset            = iso->offset;
 566                 uiso->length            = iso->length;
 567                 uiso->status            = iso->status;
 568                 uiso->actual_length     = iso->actual_length;
 569         }
 570 }
 571
 572 /* must free buffer */
 573 struct usbip_iso_packet_descriptor*
 574 usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
 575 {
 576         struct usbip_iso_packet_descriptor *iso;
 577         int np = urb->number_of_packets;
 578         ssize_t size = np * sizeof(*iso);
 579         int i;
 580
 581         iso = kzalloc(size, GFP_KERNEL);
 582         if (!iso)
 583                 return NULL;
 584
 585         for (i = 0; i < np; i++) {
 586                 usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 1);
 587                 usbip_iso_packet_correct_endian(&iso[i], 1);
 588         }
 589
 590         *bufflen = size;
 591
 592         return iso;
 593 }
 594 EXPORT_SYMBOL_GPL(usbip_alloc_iso_desc_pdu);
 595
 596 /* some members of urb must be substituted before. */
 597 int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
 598 {
 599         void *buff;
 600         struct usbip_iso_packet_descriptor *iso;
 601         int np = urb->number_of_packets;
 602         int size = np * sizeof(*iso);
 603         int i;
 604         int ret;
 605         int total_length = 0;
 606
 607         if (!usb_pipeisoc(urb->pipe))
 608                 return 0;
 609
 610         /* my Bluetooth dongle gets ISO URBs which are np = 0 */
 611         if (np == 0)
 612                 return 0;
 613
 614         buff = kzalloc(size, GFP_KERNEL);
 615         if (!buff)
 616                 return -ENOMEM;
 617
 618         ret = usbip_recv(ud->tcp_socket, buff, size);
 619         if (ret != size) {
 620                 dev_err(&urb->dev->dev, "recv iso_frame_descriptor, %d\n",
 621                         ret);
 622                 kfree(buff);
 623
 624                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
 625                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 626                 else
 627                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 628
 629                 return -EPIPE;
 630         }
 631
 632         iso = (struct usbip_iso_packet_descriptor *) buff;
 633         for (i = 0; i < np; i++) {
 634                 usbip_iso_packet_correct_endian(&iso[i], 0);
 635                 usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 0);
 636                 total_length += urb->iso_frame_desc[i].actual_length;
 637         }
 638
 639         kfree(buff);
 640
 641         if (total_length != urb->actual_length) {
 642                 dev_err(&urb->dev->dev,
 643                         "total length of iso packets %d not equal to actual length of buffer %d\n",
 644                         total_length, urb->actual_length);
 645
 646                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
 647                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 648                 else
 649                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 650
 651                 return -EPIPE;
 652         }
 653
 654         return ret;
 655 }
 656 EXPORT_SYMBOL_GPL(usbip_recv_iso);
 657
 658 /*
 659  * This functions restores the padding which was removed for optimizing
 660  * the bandwidth during transfer over tcp/ip
 661  *
 662  * buffer and iso packets need to be stored and be in propeper endian in urb
 663  * before calling this function
 664  */
 665 void usbip_pad_iso(struct usbip_device *ud, struct urb *urb)
 666 {
 667         int np = urb->number_of_packets;
 668         int i;
 669         int actualoffset = urb->actual_length;
 670
 671         if (!usb_pipeisoc(urb->pipe))
 672                 return;
 673
 674         /* if no packets or length of data is 0, then nothing to unpack */
 675         if (np == 0 || urb->actual_length == 0)
 676                 return;
 677
 678         /*
 679          * if actual_length is transfer_buffer_length then no padding is
 680          * present.
 681          */
 682         if (urb->actual_length == urb->transfer_buffer_length)
 683                 return;
 684
 685         /*
 686          * loop over all packets from last to first (to prevent overwriting
 687          * memory when padding) and move them into the proper place
 688          */
 689         for (i = np-1; i > 0; i--) {
 690                 actualoffset -= urb->iso_frame_desc[i].actual_length;
 691                 memmove(urb->transfer_buffer + urb->iso_frame_desc[i].offset,
 692                         urb->transfer_buffer + actualoffset,
 693                         urb->iso_frame_desc[i].actual_length);
 694         }
 695 }
 696 EXPORT_SYMBOL_GPL(usbip_pad_iso);
 697
 698 /* some members of urb must be substituted before. */
 699 int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
 700 {
 701         int ret;
 702         int size;
 703
 704         if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
 705                 /* the direction of urb must be OUT. */
 706                 if (usb_pipein(urb->pipe))
 707                         return 0;
 708
 709                 size = urb->transfer_buffer_length;
 710         } else {
 711                 /* the direction of urb must be IN. */
 712                 if (usb_pipeout(urb->pipe))
 713                         return 0;
 714
 715                 size = urb->actual_length;
 716         }
 717
 718         /* no need to recv xbuff */
 719         if (!(size > 0))
 720                 return 0;
 721
 722         if (size > urb->transfer_buffer_length) {
 723                 /* should not happen, probably malicious packet */
 724                 if (ud->side == USBIP_STUB) {
 725                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 726                         return 0;
 727                 } else {
 728                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 729                         return -EPIPE;
 730                 }
 731         }
 732
 733         ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
 734         if (ret != size) {
 735                 dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
 736                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
 737                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 738                 } else {
 739                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 740                         return -EPIPE;
 741                 }
 742         }
 743
 744         return ret;
 745 }
 746 EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
 747
 748 static int __init usbip_core_init(void)
 749 {
 750         int ret;
 751
 752         ret = usbip_init_eh();
 753         if (ret)
 754                 return ret;
 755
 756         return 0;
 757 }
 758
 759 static void __exit usbip_core_exit(void)
 760 {
 761         usbip_finish_eh();
 762         return;
 763 }
 764
 765 module_init(usbip_core_init);
 766 module_exit(usbip_core_exit);
 767
 768 MODULE_AUTHOR(DRIVER_AUTHOR);
 769 MODULE_DESCRIPTION(DRIVER_DESC);
 770 MODULE_LICENSE("GPL");