linux/drivers/usb/usbip/usbip_common.c
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   1/*
   2 * Copyright (C) 2003-2008 Takahiro Hirofuchi
   3 *
   4 * This is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License as published by
   6 * the Free Software Foundation; either version 2 of the License, or
   7 * (at your option) any later version.
   8 *
   9 * This is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17 * USA.
  18 */
  19
  20#include <asm/byteorder.h>
  21#include <linux/file.h>
  22#include <linux/fs.h>
  23#include <linux/kernel.h>
  24#include <linux/slab.h>
  25#include <linux/stat.h>
  26#include <linux/module.h>
  27#include <linux/moduleparam.h>
  28#include <net/sock.h>
  29
  30#include "usbip_common.h"
  31
  32#define DRIVER_AUTHOR "Takahiro Hirofuchi <hirofuchi@users.sourceforge.net>"
  33#define DRIVER_DESC "USB/IP Core"
  34
  35#ifdef CONFIG_USBIP_DEBUG
  36unsigned long usbip_debug_flag = 0xffffffff;
  37#else
  38unsigned long usbip_debug_flag;
  39#endif
  40EXPORT_SYMBOL_GPL(usbip_debug_flag);
  41module_param(usbip_debug_flag, ulong, S_IRUGO|S_IWUSR);
  42MODULE_PARM_DESC(usbip_debug_flag, "debug flags (defined in usbip_common.h)");
  43
  44/* FIXME */
  45struct device_attribute dev_attr_usbip_debug;
  46EXPORT_SYMBOL_GPL(dev_attr_usbip_debug);
  47
  48static ssize_t usbip_debug_show(struct device *dev,
  49                                struct device_attribute *attr, char *buf)
  50{
  51        return sprintf(buf, "%lx\n", usbip_debug_flag);
  52}
  53
  54static ssize_t usbip_debug_store(struct device *dev,
  55                                 struct device_attribute *attr, const char *buf,
  56                                 size_t count)
  57{
  58        if (sscanf(buf, "%lx", &usbip_debug_flag) != 1)
  59                return -EINVAL;
  60        return count;
  61}
  62DEVICE_ATTR_RW(usbip_debug);
  63
  64static void usbip_dump_buffer(char *buff, int bufflen)
  65{
  66        print_hex_dump(KERN_DEBUG, "usbip-core", DUMP_PREFIX_OFFSET, 16, 4,
  67                       buff, bufflen, false);
  68}
  69
  70static void usbip_dump_pipe(unsigned int p)
  71{
  72        unsigned char type = usb_pipetype(p);
  73        unsigned char ep   = usb_pipeendpoint(p);
  74        unsigned char dev  = usb_pipedevice(p);
  75        unsigned char dir  = usb_pipein(p);
  76
  77        pr_debug("dev(%d) ep(%d) [%s] ", dev, ep, dir ? "IN" : "OUT");
  78
  79        switch (type) {
  80        case PIPE_ISOCHRONOUS:
  81                pr_debug("ISO\n");
  82                break;
  83        case PIPE_INTERRUPT:
  84                pr_debug("INT\n");
  85                break;
  86        case PIPE_CONTROL:
  87                pr_debug("CTRL\n");
  88                break;
  89        case PIPE_BULK:
  90                pr_debug("BULK\n");
  91                break;
  92        default:
  93                pr_debug("ERR\n");
  94                break;
  95        }
  96}
  97
  98static void usbip_dump_usb_device(struct usb_device *udev)
  99{
 100        struct device *dev = &udev->dev;
 101        int i;
 102
 103        dev_dbg(dev, "       devnum(%d) devpath(%s) usb speed(%s)",
 104                udev->devnum, udev->devpath, usb_speed_string(udev->speed));
 105
 106        pr_debug("tt %p, ttport %d\n", udev->tt, udev->ttport);
 107
 108        dev_dbg(dev, "                    ");
 109        for (i = 0; i < 16; i++)
 110                pr_debug(" %2u", i);
 111        pr_debug("\n");
 112
 113        dev_dbg(dev, "       toggle0(IN) :");
 114        for (i = 0; i < 16; i++)
 115                pr_debug(" %2u", (udev->toggle[0] & (1 << i)) ? 1 : 0);
 116        pr_debug("\n");
 117
 118        dev_dbg(dev, "       toggle1(OUT):");
 119        for (i = 0; i < 16; i++)
 120                pr_debug(" %2u", (udev->toggle[1] & (1 << i)) ? 1 : 0);
 121        pr_debug("\n");
 122
 123        dev_dbg(dev, "       epmaxp_in   :");
 124        for (i = 0; i < 16; i++) {
 125                if (udev->ep_in[i])
 126                        pr_debug(" %2u",
 127                            le16_to_cpu(udev->ep_in[i]->desc.wMaxPacketSize));
 128        }
 129        pr_debug("\n");
 130
 131        dev_dbg(dev, "       epmaxp_out  :");
 132        for (i = 0; i < 16; i++) {
 133                if (udev->ep_out[i])
 134                        pr_debug(" %2u",
 135                            le16_to_cpu(udev->ep_out[i]->desc.wMaxPacketSize));
 136        }
 137        pr_debug("\n");
 138
 139        dev_dbg(dev, "parent %p, bus %p\n", udev->parent, udev->bus);
 140
 141        dev_dbg(dev,
 142                "descriptor %p, config %p, actconfig %p, rawdescriptors %p\n",
 143                &udev->descriptor, udev->config,
 144                udev->actconfig, udev->rawdescriptors);
 145
 146        dev_dbg(dev, "have_langid %d, string_langid %d\n",
 147                udev->have_langid, udev->string_langid);
 148
 149        dev_dbg(dev, "maxchild %d\n", udev->maxchild);
 150}
 151
 152static void usbip_dump_request_type(__u8 rt)
 153{
 154        switch (rt & USB_RECIP_MASK) {
 155        case USB_RECIP_DEVICE:
 156                pr_debug("DEVICE");
 157                break;
 158        case USB_RECIP_INTERFACE:
 159                pr_debug("INTERF");
 160                break;
 161        case USB_RECIP_ENDPOINT:
 162                pr_debug("ENDPOI");
 163                break;
 164        case USB_RECIP_OTHER:
 165                pr_debug("OTHER ");
 166                break;
 167        default:
 168                pr_debug("------");
 169                break;
 170        }
 171}
 172
 173static void usbip_dump_usb_ctrlrequest(struct usb_ctrlrequest *cmd)
 174{
 175        if (!cmd) {
 176                pr_debug("       : null pointer\n");
 177                return;
 178        }
 179
 180        pr_debug("       ");
 181        pr_debug("bRequestType(%02X) bRequest(%02X) wValue(%04X) wIndex(%04X) wLength(%04X) ",
 182                 cmd->bRequestType, cmd->bRequest,
 183                 cmd->wValue, cmd->wIndex, cmd->wLength);
 184        pr_debug("\n       ");
 185
 186        if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
 187                pr_debug("STANDARD ");
 188                switch (cmd->bRequest) {
 189                case USB_REQ_GET_STATUS:
 190                        pr_debug("GET_STATUS\n");
 191                        break;
 192                case USB_REQ_CLEAR_FEATURE:
 193                        pr_debug("CLEAR_FEAT\n");
 194                        break;
 195                case USB_REQ_SET_FEATURE:
 196                        pr_debug("SET_FEAT\n");
 197                        break;
 198                case USB_REQ_SET_ADDRESS:
 199                        pr_debug("SET_ADDRRS\n");
 200                        break;
 201                case USB_REQ_GET_DESCRIPTOR:
 202                        pr_debug("GET_DESCRI\n");
 203                        break;
 204                case USB_REQ_SET_DESCRIPTOR:
 205                        pr_debug("SET_DESCRI\n");
 206                        break;
 207                case USB_REQ_GET_CONFIGURATION:
 208                        pr_debug("GET_CONFIG\n");
 209                        break;
 210                case USB_REQ_SET_CONFIGURATION:
 211                        pr_debug("SET_CONFIG\n");
 212                        break;
 213                case USB_REQ_GET_INTERFACE:
 214                        pr_debug("GET_INTERF\n");
 215                        break;
 216                case USB_REQ_SET_INTERFACE:
 217                        pr_debug("SET_INTERF\n");
 218                        break;
 219                case USB_REQ_SYNCH_FRAME:
 220                        pr_debug("SYNC_FRAME\n");
 221                        break;
 222                default:
 223                        pr_debug("REQ(%02X)\n", cmd->bRequest);
 224                        break;
 225                }
 226                usbip_dump_request_type(cmd->bRequestType);
 227        } else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS) {
 228                pr_debug("CLASS\n");
 229        } else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_VENDOR) {
 230                pr_debug("VENDOR\n");
 231        } else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_RESERVED) {
 232                pr_debug("RESERVED\n");
 233        }
 234}
 235
 236void usbip_dump_urb(struct urb *urb)
 237{
 238        struct device *dev;
 239
 240        if (!urb) {
 241                pr_debug("urb: null pointer!!\n");
 242                return;
 243        }
 244
 245        if (!urb->dev) {
 246                pr_debug("urb->dev: null pointer!!\n");
 247                return;
 248        }
 249
 250        dev = &urb->dev->dev;
 251
 252        dev_dbg(dev, "   urb                   :%p\n", urb);
 253        dev_dbg(dev, "   dev                   :%p\n", urb->dev);
 254
 255        usbip_dump_usb_device(urb->dev);
 256
 257        dev_dbg(dev, "   pipe                  :%08x ", urb->pipe);
 258
 259        usbip_dump_pipe(urb->pipe);
 260
 261        dev_dbg(dev, "   status                :%d\n", urb->status);
 262        dev_dbg(dev, "   transfer_flags        :%08X\n", urb->transfer_flags);
 263        dev_dbg(dev, "   transfer_buffer       :%p\n", urb->transfer_buffer);
 264        dev_dbg(dev, "   transfer_buffer_length:%d\n",
 265                                                urb->transfer_buffer_length);
 266        dev_dbg(dev, "   actual_length         :%d\n", urb->actual_length);
 267        dev_dbg(dev, "   setup_packet          :%p\n", urb->setup_packet);
 268
 269        if (urb->setup_packet && usb_pipetype(urb->pipe) == PIPE_CONTROL)
 270                usbip_dump_usb_ctrlrequest(
 271                        (struct usb_ctrlrequest *)urb->setup_packet);
 272
 273        dev_dbg(dev, "   start_frame           :%d\n", urb->start_frame);
 274        dev_dbg(dev, "   number_of_packets     :%d\n", urb->number_of_packets);
 275        dev_dbg(dev, "   interval              :%d\n", urb->interval);
 276        dev_dbg(dev, "   error_count           :%d\n", urb->error_count);
 277        dev_dbg(dev, "   context               :%p\n", urb->context);
 278        dev_dbg(dev, "   complete              :%p\n", urb->complete);
 279}
 280EXPORT_SYMBOL_GPL(usbip_dump_urb);
 281
 282void usbip_dump_header(struct usbip_header *pdu)
 283{
 284        pr_debug("BASE: cmd %u seq %u devid %u dir %u ep %u\n",
 285                 pdu->base.command,
 286                 pdu->base.seqnum,
 287                 pdu->base.devid,
 288                 pdu->base.direction,
 289                 pdu->base.ep);
 290
 291        switch (pdu->base.command) {
 292        case USBIP_CMD_SUBMIT:
 293                pr_debug("USBIP_CMD_SUBMIT: x_flags %u x_len %u sf %u #p %d iv %d\n",
 294                         pdu->u.cmd_submit.transfer_flags,
 295                         pdu->u.cmd_submit.transfer_buffer_length,
 296                         pdu->u.cmd_submit.start_frame,
 297                         pdu->u.cmd_submit.number_of_packets,
 298                         pdu->u.cmd_submit.interval);
 299                break;
 300        case USBIP_CMD_UNLINK:
 301                pr_debug("USBIP_CMD_UNLINK: seq %u\n",
 302                         pdu->u.cmd_unlink.seqnum);
 303                break;
 304        case USBIP_RET_SUBMIT:
 305                pr_debug("USBIP_RET_SUBMIT: st %d al %u sf %d #p %d ec %d\n",
 306                         pdu->u.ret_submit.status,
 307                         pdu->u.ret_submit.actual_length,
 308                         pdu->u.ret_submit.start_frame,
 309                         pdu->u.ret_submit.number_of_packets,
 310                         pdu->u.ret_submit.error_count);
 311                break;
 312        case USBIP_RET_UNLINK:
 313                pr_debug("USBIP_RET_UNLINK: status %d\n",
 314                         pdu->u.ret_unlink.status);
 315                break;
 316        default:
 317                /* NOT REACHED */
 318                pr_err("unknown command\n");
 319                break;
 320        }
 321}
 322EXPORT_SYMBOL_GPL(usbip_dump_header);
 323
 324/* Receive data over TCP/IP. */
 325int usbip_recv(struct socket *sock, void *buf, int size)
 326{
 327        int result;
 328        struct msghdr msg;
 329        struct kvec iov;
 330        int total = 0;
 331
 332        /* for blocks of if (usbip_dbg_flag_xmit) */
 333        char *bp = buf;
 334        int osize = size;
 335
 336        usbip_dbg_xmit("enter\n");
 337
 338        if (!sock || !buf || !size) {
 339                pr_err("invalid arg, sock %p buff %p size %d\n", sock, buf,
 340                       size);
 341                return -EINVAL;
 342        }
 343
 344        do {
 345                sock->sk->sk_allocation = GFP_NOIO;
 346                iov.iov_base    = buf;
 347                iov.iov_len     = size;
 348                msg.msg_name    = NULL;
 349                msg.msg_namelen = 0;
 350                msg.msg_control = NULL;
 351                msg.msg_controllen = 0;
 352                msg.msg_flags      = MSG_NOSIGNAL;
 353
 354                result = kernel_recvmsg(sock, &msg, &iov, 1, size, MSG_WAITALL);
 355                if (result <= 0) {
 356                        pr_debug("receive sock %p buf %p size %u ret %d total %d\n",
 357                                 sock, buf, size, result, total);
 358                        goto err;
 359                }
 360
 361                size -= result;
 362                buf += result;
 363                total += result;
 364        } while (size > 0);
 365
 366        if (usbip_dbg_flag_xmit) {
 367                if (!in_interrupt())
 368                        pr_debug("%-10s:", current->comm);
 369                else
 370                        pr_debug("interrupt  :");
 371
 372                pr_debug("receiving....\n");
 373                usbip_dump_buffer(bp, osize);
 374                pr_debug("received, osize %d ret %d size %d total %d\n",
 375                         osize, result, size, total);
 376        }
 377
 378        return total;
 379
 380err:
 381        return result;
 382}
 383EXPORT_SYMBOL_GPL(usbip_recv);
 384
 385/* there may be more cases to tweak the flags. */
 386static unsigned int tweak_transfer_flags(unsigned int flags)
 387{
 388        flags &= ~URB_NO_TRANSFER_DMA_MAP;
 389        return flags;
 390}
 391
 392static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,
 393                                  int pack)
 394{
 395        struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;
 396
 397        /*
 398         * Some members are not still implemented in usbip. I hope this issue
 399         * will be discussed when usbip is ported to other operating systems.
 400         */
 401        if (pack) {
 402                spdu->transfer_flags =
 403                        tweak_transfer_flags(urb->transfer_flags);
 404                spdu->transfer_buffer_length    = urb->transfer_buffer_length;
 405                spdu->start_frame               = urb->start_frame;
 406                spdu->number_of_packets         = urb->number_of_packets;
 407                spdu->interval                  = urb->interval;
 408        } else  {
 409                urb->transfer_flags         = spdu->transfer_flags;
 410                urb->transfer_buffer_length = spdu->transfer_buffer_length;
 411                urb->start_frame            = spdu->start_frame;
 412                urb->number_of_packets      = spdu->number_of_packets;
 413                urb->interval               = spdu->interval;
 414        }
 415}
 416
 417static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
 418                                  int pack)
 419{
 420        struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;
 421
 422        if (pack) {
 423                rpdu->status            = urb->status;
 424                rpdu->actual_length     = urb->actual_length;
 425                rpdu->start_frame       = urb->start_frame;
 426                rpdu->number_of_packets = urb->number_of_packets;
 427                rpdu->error_count       = urb->error_count;
 428        } else {
 429                urb->status             = rpdu->status;
 430                urb->actual_length      = rpdu->actual_length;
 431                urb->start_frame        = rpdu->start_frame;
 432                urb->number_of_packets = rpdu->number_of_packets;
 433                urb->error_count        = rpdu->error_count;
 434        }
 435}
 436
 437void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
 438                    int pack)
 439{
 440        switch (cmd) {
 441        case USBIP_CMD_SUBMIT:
 442                usbip_pack_cmd_submit(pdu, urb, pack);
 443                break;
 444        case USBIP_RET_SUBMIT:
 445                usbip_pack_ret_submit(pdu, urb, pack);
 446                break;
 447        default:
 448                /* NOT REACHED */
 449                pr_err("unknown command\n");
 450                break;
 451        }
 452}
 453EXPORT_SYMBOL_GPL(usbip_pack_pdu);
 454
 455static void correct_endian_basic(struct usbip_header_basic *base, int send)
 456{
 457        if (send) {
 458                base->command   = cpu_to_be32(base->command);
 459                base->seqnum    = cpu_to_be32(base->seqnum);
 460                base->devid     = cpu_to_be32(base->devid);
 461                base->direction = cpu_to_be32(base->direction);
 462                base->ep        = cpu_to_be32(base->ep);
 463        } else {
 464                base->command   = be32_to_cpu(base->command);
 465                base->seqnum    = be32_to_cpu(base->seqnum);
 466                base->devid     = be32_to_cpu(base->devid);
 467                base->direction = be32_to_cpu(base->direction);
 468                base->ep        = be32_to_cpu(base->ep);
 469        }
 470}
 471
 472static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu,
 473                                      int send)
 474{
 475        if (send) {
 476                pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);
 477
 478                cpu_to_be32s(&pdu->transfer_buffer_length);
 479                cpu_to_be32s(&pdu->start_frame);
 480                cpu_to_be32s(&pdu->number_of_packets);
 481                cpu_to_be32s(&pdu->interval);
 482        } else {
 483                pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);
 484
 485                be32_to_cpus(&pdu->transfer_buffer_length);
 486                be32_to_cpus(&pdu->start_frame);
 487                be32_to_cpus(&pdu->number_of_packets);
 488                be32_to_cpus(&pdu->interval);
 489        }
 490}
 491
 492static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu,
 493                                      int send)
 494{
 495        if (send) {
 496                cpu_to_be32s(&pdu->status);
 497                cpu_to_be32s(&pdu->actual_length);
 498                cpu_to_be32s(&pdu->start_frame);
 499                cpu_to_be32s(&pdu->number_of_packets);
 500                cpu_to_be32s(&pdu->error_count);
 501        } else {
 502                be32_to_cpus(&pdu->status);
 503                be32_to_cpus(&pdu->actual_length);
 504                be32_to_cpus(&pdu->start_frame);
 505                be32_to_cpus(&pdu->number_of_packets);
 506                be32_to_cpus(&pdu->error_count);
 507        }
 508}
 509
 510static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu,
 511                                      int send)
 512{
 513        if (send)
 514                pdu->seqnum = cpu_to_be32(pdu->seqnum);
 515        else
 516                pdu->seqnum = be32_to_cpu(pdu->seqnum);
 517}
 518
 519static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu,
 520                                      int send)
 521{
 522        if (send)
 523                cpu_to_be32s(&pdu->status);
 524        else
 525                be32_to_cpus(&pdu->status);
 526}
 527
 528void usbip_header_correct_endian(struct usbip_header *pdu, int send)
 529{
 530        __u32 cmd = 0;
 531
 532        if (send)
 533                cmd = pdu->base.command;
 534
 535        correct_endian_basic(&pdu->base, send);
 536
 537        if (!send)
 538                cmd = pdu->base.command;
 539
 540        switch (cmd) {
 541        case USBIP_CMD_SUBMIT:
 542                correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
 543                break;
 544        case USBIP_RET_SUBMIT:
 545                correct_endian_ret_submit(&pdu->u.ret_submit, send);
 546                break;
 547        case USBIP_CMD_UNLINK:
 548                correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
 549                break;
 550        case USBIP_RET_UNLINK:
 551                correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
 552                break;
 553        default:
 554                /* NOT REACHED */
 555                pr_err("unknown command\n");
 556                break;
 557        }
 558}
 559EXPORT_SYMBOL_GPL(usbip_header_correct_endian);
 560
 561static void usbip_iso_packet_correct_endian(
 562                struct usbip_iso_packet_descriptor *iso, int send)
 563{
 564        /* does not need all members. but copy all simply. */
 565        if (send) {
 566                iso->offset     = cpu_to_be32(iso->offset);
 567                iso->length     = cpu_to_be32(iso->length);
 568                iso->status     = cpu_to_be32(iso->status);
 569                iso->actual_length = cpu_to_be32(iso->actual_length);
 570        } else {
 571                iso->offset     = be32_to_cpu(iso->offset);
 572                iso->length     = be32_to_cpu(iso->length);
 573                iso->status     = be32_to_cpu(iso->status);
 574                iso->actual_length = be32_to_cpu(iso->actual_length);
 575        }
 576}
 577
 578static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
 579                           struct usb_iso_packet_descriptor *uiso, int pack)
 580{
 581        if (pack) {
 582                iso->offset             = uiso->offset;
 583                iso->length             = uiso->length;
 584                iso->status             = uiso->status;
 585                iso->actual_length      = uiso->actual_length;
 586        } else {
 587                uiso->offset            = iso->offset;
 588                uiso->length            = iso->length;
 589                uiso->status            = iso->status;
 590                uiso->actual_length     = iso->actual_length;
 591        }
 592}
 593
 594/* must free buffer */
 595struct usbip_iso_packet_descriptor*
 596usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
 597{
 598        struct usbip_iso_packet_descriptor *iso;
 599        int np = urb->number_of_packets;
 600        ssize_t size = np * sizeof(*iso);
 601        int i;
 602
 603        iso = kzalloc(size, GFP_KERNEL);
 604        if (!iso)
 605                return NULL;
 606
 607        for (i = 0; i < np; i++) {
 608                usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 1);
 609                usbip_iso_packet_correct_endian(&iso[i], 1);
 610        }
 611
 612        *bufflen = size;
 613
 614        return iso;
 615}
 616EXPORT_SYMBOL_GPL(usbip_alloc_iso_desc_pdu);
 617
 618/* some members of urb must be substituted before. */
 619int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
 620{
 621        void *buff;
 622        struct usbip_iso_packet_descriptor *iso;
 623        int np = urb->number_of_packets;
 624        int size = np * sizeof(*iso);
 625        int i;
 626        int ret;
 627        int total_length = 0;
 628
 629        if (!usb_pipeisoc(urb->pipe))
 630                return 0;
 631
 632        /* my Bluetooth dongle gets ISO URBs which are np = 0 */
 633        if (np == 0)
 634                return 0;
 635
 636        buff = kzalloc(size, GFP_KERNEL);
 637        if (!buff)
 638                return -ENOMEM;
 639
 640        ret = usbip_recv(ud->tcp_socket, buff, size);
 641        if (ret != size) {
 642                dev_err(&urb->dev->dev, "recv iso_frame_descriptor, %d\n",
 643                        ret);
 644                kfree(buff);
 645
 646                if (ud->side == USBIP_STUB)
 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        iso = (struct usbip_iso_packet_descriptor *) buff;
 655        for (i = 0; i < np; i++) {
 656                usbip_iso_packet_correct_endian(&iso[i], 0);
 657                usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 0);
 658                total_length += urb->iso_frame_desc[i].actual_length;
 659        }
 660
 661        kfree(buff);
 662
 663        if (total_length != urb->actual_length) {
 664                dev_err(&urb->dev->dev,
 665                        "total length of iso packets %d not equal to actual length of buffer %d\n",
 666                        total_length, urb->actual_length);
 667
 668                if (ud->side == USBIP_STUB)
 669                        usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 670                else
 671                        usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 672
 673                return -EPIPE;
 674        }
 675
 676        return ret;
 677}
 678EXPORT_SYMBOL_GPL(usbip_recv_iso);
 679
 680/*
 681 * This functions restores the padding which was removed for optimizing
 682 * the bandwidth during transfer over tcp/ip
 683 *
 684 * buffer and iso packets need to be stored and be in propeper endian in urb
 685 * before calling this function
 686 */
 687void usbip_pad_iso(struct usbip_device *ud, struct urb *urb)
 688{
 689        int np = urb->number_of_packets;
 690        int i;
 691        int actualoffset = urb->actual_length;
 692
 693        if (!usb_pipeisoc(urb->pipe))
 694                return;
 695
 696        /* if no packets or length of data is 0, then nothing to unpack */
 697        if (np == 0 || urb->actual_length == 0)
 698                return;
 699
 700        /*
 701         * if actual_length is transfer_buffer_length then no padding is
 702         * present.
 703         */
 704        if (urb->actual_length == urb->transfer_buffer_length)
 705                return;
 706
 707        /*
 708         * loop over all packets from last to first (to prevent overwritting
 709         * memory when padding) and move them into the proper place
 710         */
 711        for (i = np-1; i > 0; i--) {
 712                actualoffset -= urb->iso_frame_desc[i].actual_length;
 713                memmove(urb->transfer_buffer + urb->iso_frame_desc[i].offset,
 714                        urb->transfer_buffer + actualoffset,
 715                        urb->iso_frame_desc[i].actual_length);
 716        }
 717}
 718EXPORT_SYMBOL_GPL(usbip_pad_iso);
 719
 720/* some members of urb must be substituted before. */
 721int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
 722{
 723        int ret;
 724        int size;
 725
 726        if (ud->side == USBIP_STUB) {
 727                /* the direction of urb must be OUT. */
 728                if (usb_pipein(urb->pipe))
 729                        return 0;
 730
 731                size = urb->transfer_buffer_length;
 732        } else {
 733                /* the direction of urb must be IN. */
 734                if (usb_pipeout(urb->pipe))
 735                        return 0;
 736
 737                size = urb->actual_length;
 738        }
 739
 740        /* no need to recv xbuff */
 741        if (!(size > 0))
 742                return 0;
 743
 744        ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
 745        if (ret != size) {
 746                dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
 747                if (ud->side == USBIP_STUB) {
 748                        usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
 749                } else {
 750                        usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
 751                        return -EPIPE;
 752                }
 753        }
 754
 755        return ret;
 756}
 757EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
 758
 759static int __init usbip_core_init(void)
 760{
 761        pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
 762        return 0;
 763}
 764
 765static void __exit usbip_core_exit(void)
 766{
 767        return;
 768}
 769
 770module_init(usbip_core_init);
 771module_exit(usbip_core_exit);
 772
 773MODULE_AUTHOR(DRIVER_AUTHOR);
 774MODULE_DESCRIPTION(DRIVER_DESC);
 775MODULE_LICENSE("GPL");
 776MODULE_VERSION(USBIP_VERSION);
 777