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