Merge tag 'gcc-plugins-v4.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git...
[cascardo/linux.git] / drivers / usb / usbip / usbip_common.c
1 /*
2  * Copyright (C) 2003-2008 Takahiro Hirofuchi
3  * Copyright (C) 2015-2016 Samsung Electronics
4  *               Krzysztof Opasiak <k.opasiak@samsung.com>
5  *
6  * This is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19  * USA.
20  */
21
22 #include <asm/byteorder.h>
23 #include <linux/file.h>
24 #include <linux/fs.h>
25 #include <linux/kernel.h>
26 #include <linux/slab.h>
27 #include <linux/stat.h>
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <net/sock.h>
31
32 #include "usbip_common.h"
33
34 #define DRIVER_AUTHOR "Takahiro Hirofuchi <hirofuchi@users.sourceforge.net>"
35 #define DRIVER_DESC "USB/IP Core"
36
37 #ifdef CONFIG_USBIP_DEBUG
38 unsigned long usbip_debug_flag = 0xffffffff;
39 #else
40 unsigned long usbip_debug_flag;
41 #endif
42 EXPORT_SYMBOL_GPL(usbip_debug_flag);
43 module_param(usbip_debug_flag, ulong, S_IRUGO|S_IWUSR);
44 MODULE_PARM_DESC(usbip_debug_flag, "debug flags (defined in usbip_common.h)");
45
46 /* FIXME */
47 struct device_attribute dev_attr_usbip_debug;
48 EXPORT_SYMBOL_GPL(dev_attr_usbip_debug);
49
50 static ssize_t usbip_debug_show(struct device *dev,
51                                 struct device_attribute *attr, char *buf)
52 {
53         return sprintf(buf, "%lx\n", usbip_debug_flag);
54 }
55
56 static ssize_t usbip_debug_store(struct device *dev,
57                                  struct device_attribute *attr, const char *buf,
58                                  size_t count)
59 {
60         if (sscanf(buf, "%lx", &usbip_debug_flag) != 1)
61                 return -EINVAL;
62         return count;
63 }
64 DEVICE_ATTR_RW(usbip_debug);
65
66 static void usbip_dump_buffer(char *buff, int bufflen)
67 {
68         print_hex_dump(KERN_DEBUG, "usbip-core", DUMP_PREFIX_OFFSET, 16, 4,
69                        buff, bufflen, false);
70 }
71
72 static void usbip_dump_pipe(unsigned int p)
73 {
74         unsigned char type = usb_pipetype(p);
75         unsigned char ep   = usb_pipeendpoint(p);
76         unsigned char dev  = usb_pipedevice(p);
77         unsigned char dir  = usb_pipein(p);
78
79         pr_debug("dev(%d) ep(%d) [%s] ", dev, ep, dir ? "IN" : "OUT");
80
81         switch (type) {
82         case PIPE_ISOCHRONOUS:
83                 pr_debug("ISO\n");
84                 break;
85         case PIPE_INTERRUPT:
86                 pr_debug("INT\n");
87                 break;
88         case PIPE_CONTROL:
89                 pr_debug("CTRL\n");
90                 break;
91         case PIPE_BULK:
92                 pr_debug("BULK\n");
93                 break;
94         default:
95                 pr_debug("ERR\n");
96                 break;
97         }
98 }
99
100 static void usbip_dump_usb_device(struct usb_device *udev)
101 {
102         struct device *dev = &udev->dev;
103         int i;
104
105         dev_dbg(dev, "       devnum(%d) devpath(%s) usb speed(%s)",
106                 udev->devnum, udev->devpath, usb_speed_string(udev->speed));
107
108         pr_debug("tt %p, ttport %d\n", udev->tt, udev->ttport);
109
110         dev_dbg(dev, "                    ");
111         for (i = 0; i < 16; i++)
112                 pr_debug(" %2u", i);
113         pr_debug("\n");
114
115         dev_dbg(dev, "       toggle0(IN) :");
116         for (i = 0; i < 16; i++)
117                 pr_debug(" %2u", (udev->toggle[0] & (1 << i)) ? 1 : 0);
118         pr_debug("\n");
119
120         dev_dbg(dev, "       toggle1(OUT):");
121         for (i = 0; i < 16; i++)
122                 pr_debug(" %2u", (udev->toggle[1] & (1 << i)) ? 1 : 0);
123         pr_debug("\n");
124
125         dev_dbg(dev, "       epmaxp_in   :");
126         for (i = 0; i < 16; i++) {
127                 if (udev->ep_in[i])
128                         pr_debug(" %2u",
129                             le16_to_cpu(udev->ep_in[i]->desc.wMaxPacketSize));
130         }
131         pr_debug("\n");
132
133         dev_dbg(dev, "       epmaxp_out  :");
134         for (i = 0; i < 16; i++) {
135                 if (udev->ep_out[i])
136                         pr_debug(" %2u",
137                             le16_to_cpu(udev->ep_out[i]->desc.wMaxPacketSize));
138         }
139         pr_debug("\n");
140
141         dev_dbg(dev, "parent %p, bus %p\n", udev->parent, udev->bus);
142
143         dev_dbg(dev,
144                 "descriptor %p, config %p, actconfig %p, rawdescriptors %p\n",
145                 &udev->descriptor, udev->config,
146                 udev->actconfig, udev->rawdescriptors);
147
148         dev_dbg(dev, "have_langid %d, string_langid %d\n",
149                 udev->have_langid, udev->string_langid);
150
151         dev_dbg(dev, "maxchild %d\n", udev->maxchild);
152 }
153
154 static void usbip_dump_request_type(__u8 rt)
155 {
156         switch (rt & USB_RECIP_MASK) {
157         case USB_RECIP_DEVICE:
158                 pr_debug("DEVICE");
159                 break;
160         case USB_RECIP_INTERFACE:
161                 pr_debug("INTERF");
162                 break;
163         case USB_RECIP_ENDPOINT:
164                 pr_debug("ENDPOI");
165                 break;
166         case USB_RECIP_OTHER:
167                 pr_debug("OTHER ");
168                 break;
169         default:
170                 pr_debug("------");
171                 break;
172         }
173 }
174
175 static void usbip_dump_usb_ctrlrequest(struct usb_ctrlrequest *cmd)
176 {
177         if (!cmd) {
178                 pr_debug("       : null pointer\n");
179                 return;
180         }
181
182         pr_debug("       ");
183         pr_debug("bRequestType(%02X) bRequest(%02X) wValue(%04X) wIndex(%04X) wLength(%04X) ",
184                  cmd->bRequestType, cmd->bRequest,
185                  cmd->wValue, cmd->wIndex, cmd->wLength);
186         pr_debug("\n       ");
187
188         if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
189                 pr_debug("STANDARD ");
190                 switch (cmd->bRequest) {
191                 case USB_REQ_GET_STATUS:
192                         pr_debug("GET_STATUS\n");
193                         break;
194                 case USB_REQ_CLEAR_FEATURE:
195                         pr_debug("CLEAR_FEAT\n");
196                         break;
197                 case USB_REQ_SET_FEATURE:
198                         pr_debug("SET_FEAT\n");
199                         break;
200                 case USB_REQ_SET_ADDRESS:
201                         pr_debug("SET_ADDRRS\n");
202                         break;
203                 case USB_REQ_GET_DESCRIPTOR:
204                         pr_debug("GET_DESCRI\n");
205                         break;
206                 case USB_REQ_SET_DESCRIPTOR:
207                         pr_debug("SET_DESCRI\n");
208                         break;
209                 case USB_REQ_GET_CONFIGURATION:
210                         pr_debug("GET_CONFIG\n");
211                         break;
212                 case USB_REQ_SET_CONFIGURATION:
213                         pr_debug("SET_CONFIG\n");
214                         break;
215                 case USB_REQ_GET_INTERFACE:
216                         pr_debug("GET_INTERF\n");
217                         break;
218                 case USB_REQ_SET_INTERFACE:
219                         pr_debug("SET_INTERF\n");
220                         break;
221                 case USB_REQ_SYNCH_FRAME:
222                         pr_debug("SYNC_FRAME\n");
223                         break;
224                 default:
225                         pr_debug("REQ(%02X)\n", cmd->bRequest);
226                         break;
227                 }
228                 usbip_dump_request_type(cmd->bRequestType);
229         } else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS) {
230                 pr_debug("CLASS\n");
231         } else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_VENDOR) {
232                 pr_debug("VENDOR\n");
233         } else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_RESERVED) {
234                 pr_debug("RESERVED\n");
235         }
236 }
237
238 void usbip_dump_urb(struct urb *urb)
239 {
240         struct device *dev;
241
242         if (!urb) {
243                 pr_debug("urb: null pointer!!\n");
244                 return;
245         }
246
247         if (!urb->dev) {
248                 pr_debug("urb->dev: null pointer!!\n");
249                 return;
250         }
251
252         dev = &urb->dev->dev;
253
254         dev_dbg(dev, "   urb                   :%p\n", urb);
255         dev_dbg(dev, "   dev                   :%p\n", urb->dev);
256
257         usbip_dump_usb_device(urb->dev);
258
259         dev_dbg(dev, "   pipe                  :%08x ", urb->pipe);
260
261         usbip_dump_pipe(urb->pipe);
262
263         dev_dbg(dev, "   status                :%d\n", urb->status);
264         dev_dbg(dev, "   transfer_flags        :%08X\n", urb->transfer_flags);
265         dev_dbg(dev, "   transfer_buffer       :%p\n", urb->transfer_buffer);
266         dev_dbg(dev, "   transfer_buffer_length:%d\n",
267                                                 urb->transfer_buffer_length);
268         dev_dbg(dev, "   actual_length         :%d\n", urb->actual_length);
269         dev_dbg(dev, "   setup_packet          :%p\n", urb->setup_packet);
270
271         if (urb->setup_packet && usb_pipetype(urb->pipe) == PIPE_CONTROL)
272                 usbip_dump_usb_ctrlrequest(
273                         (struct usb_ctrlrequest *)urb->setup_packet);
274
275         dev_dbg(dev, "   start_frame           :%d\n", urb->start_frame);
276         dev_dbg(dev, "   number_of_packets     :%d\n", urb->number_of_packets);
277         dev_dbg(dev, "   interval              :%d\n", urb->interval);
278         dev_dbg(dev, "   error_count           :%d\n", urb->error_count);
279         dev_dbg(dev, "   context               :%p\n", urb->context);
280         dev_dbg(dev, "   complete              :%p\n", urb->complete);
281 }
282 EXPORT_SYMBOL_GPL(usbip_dump_urb);
283
284 void usbip_dump_header(struct usbip_header *pdu)
285 {
286         pr_debug("BASE: cmd %u seq %u devid %u dir %u ep %u\n",
287                  pdu->base.command,
288                  pdu->base.seqnum,
289                  pdu->base.devid,
290                  pdu->base.direction,
291                  pdu->base.ep);
292
293         switch (pdu->base.command) {
294         case USBIP_CMD_SUBMIT:
295                 pr_debug("USBIP_CMD_SUBMIT: x_flags %u x_len %u sf %u #p %d iv %d\n",
296                          pdu->u.cmd_submit.transfer_flags,
297                          pdu->u.cmd_submit.transfer_buffer_length,
298                          pdu->u.cmd_submit.start_frame,
299                          pdu->u.cmd_submit.number_of_packets,
300                          pdu->u.cmd_submit.interval);
301                 break;
302         case USBIP_CMD_UNLINK:
303                 pr_debug("USBIP_CMD_UNLINK: seq %u\n",
304                          pdu->u.cmd_unlink.seqnum);
305                 break;
306         case USBIP_RET_SUBMIT:
307                 pr_debug("USBIP_RET_SUBMIT: st %d al %u sf %d #p %d ec %d\n",
308                          pdu->u.ret_submit.status,
309                          pdu->u.ret_submit.actual_length,
310                          pdu->u.ret_submit.start_frame,
311                          pdu->u.ret_submit.number_of_packets,
312                          pdu->u.ret_submit.error_count);
313                 break;
314         case USBIP_RET_UNLINK:
315                 pr_debug("USBIP_RET_UNLINK: status %d\n",
316                          pdu->u.ret_unlink.status);
317                 break;
318         default:
319                 /* NOT REACHED */
320                 pr_err("unknown command\n");
321                 break;
322         }
323 }
324 EXPORT_SYMBOL_GPL(usbip_dump_header);
325
326 /* Receive data over TCP/IP. */
327 int usbip_recv(struct socket *sock, void *buf, int size)
328 {
329         int result;
330         struct msghdr msg;
331         struct kvec iov;
332         int total = 0;
333
334         /* for blocks of if (usbip_dbg_flag_xmit) */
335         char *bp = buf;
336         int osize = size;
337
338         usbip_dbg_xmit("enter\n");
339
340         if (!sock || !buf || !size) {
341                 pr_err("invalid arg, sock %p buff %p size %d\n", sock, buf,
342                        size);
343                 return -EINVAL;
344         }
345
346         do {
347                 sock->sk->sk_allocation = GFP_NOIO;
348                 iov.iov_base    = buf;
349                 iov.iov_len     = size;
350                 msg.msg_name    = NULL;
351                 msg.msg_namelen = 0;
352                 msg.msg_control = NULL;
353                 msg.msg_controllen = 0;
354                 msg.msg_flags      = MSG_NOSIGNAL;
355
356                 result = kernel_recvmsg(sock, &msg, &iov, 1, size, MSG_WAITALL);
357                 if (result <= 0) {
358                         pr_debug("receive sock %p buf %p size %u ret %d total %d\n",
359                                  sock, buf, size, result, total);
360                         goto err;
361                 }
362
363                 size -= result;
364                 buf += result;
365                 total += result;
366         } while (size > 0);
367
368         if (usbip_dbg_flag_xmit) {
369                 if (!in_interrupt())
370                         pr_debug("%-10s:", current->comm);
371                 else
372                         pr_debug("interrupt  :");
373
374                 pr_debug("receiving....\n");
375                 usbip_dump_buffer(bp, osize);
376                 pr_debug("received, osize %d ret %d size %d total %d\n",
377                          osize, result, size, total);
378         }
379
380         return total;
381
382 err:
383         return result;
384 }
385 EXPORT_SYMBOL_GPL(usbip_recv);
386
387 /* there may be more cases to tweak the flags. */
388 static unsigned int tweak_transfer_flags(unsigned int flags)
389 {
390         flags &= ~URB_NO_TRANSFER_DMA_MAP;
391         return flags;
392 }
393
394 static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,
395                                   int pack)
396 {
397         struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;
398
399         /*
400          * Some members are not still implemented in usbip. I hope this issue
401          * will be discussed when usbip is ported to other operating systems.
402          */
403         if (pack) {
404                 spdu->transfer_flags =
405                         tweak_transfer_flags(urb->transfer_flags);
406                 spdu->transfer_buffer_length    = urb->transfer_buffer_length;
407                 spdu->start_frame               = urb->start_frame;
408                 spdu->number_of_packets         = urb->number_of_packets;
409                 spdu->interval                  = urb->interval;
410         } else  {
411                 urb->transfer_flags         = spdu->transfer_flags;
412                 urb->transfer_buffer_length = spdu->transfer_buffer_length;
413                 urb->start_frame            = spdu->start_frame;
414                 urb->number_of_packets      = spdu->number_of_packets;
415                 urb->interval               = spdu->interval;
416         }
417 }
418
419 static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
420                                   int pack)
421 {
422         struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;
423
424         if (pack) {
425                 rpdu->status            = urb->status;
426                 rpdu->actual_length     = urb->actual_length;
427                 rpdu->start_frame       = urb->start_frame;
428                 rpdu->number_of_packets = urb->number_of_packets;
429                 rpdu->error_count       = urb->error_count;
430         } else {
431                 urb->status             = rpdu->status;
432                 urb->actual_length      = rpdu->actual_length;
433                 urb->start_frame        = rpdu->start_frame;
434                 urb->number_of_packets = rpdu->number_of_packets;
435                 urb->error_count        = rpdu->error_count;
436         }
437 }
438
439 void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
440                     int pack)
441 {
442         switch (cmd) {
443         case USBIP_CMD_SUBMIT:
444                 usbip_pack_cmd_submit(pdu, urb, pack);
445                 break;
446         case USBIP_RET_SUBMIT:
447                 usbip_pack_ret_submit(pdu, urb, pack);
448                 break;
449         default:
450                 /* NOT REACHED */
451                 pr_err("unknown command\n");
452                 break;
453         }
454 }
455 EXPORT_SYMBOL_GPL(usbip_pack_pdu);
456
457 static void correct_endian_basic(struct usbip_header_basic *base, int send)
458 {
459         if (send) {
460                 base->command   = cpu_to_be32(base->command);
461                 base->seqnum    = cpu_to_be32(base->seqnum);
462                 base->devid     = cpu_to_be32(base->devid);
463                 base->direction = cpu_to_be32(base->direction);
464                 base->ep        = cpu_to_be32(base->ep);
465         } else {
466                 base->command   = be32_to_cpu(base->command);
467                 base->seqnum    = be32_to_cpu(base->seqnum);
468                 base->devid     = be32_to_cpu(base->devid);
469                 base->direction = be32_to_cpu(base->direction);
470                 base->ep        = be32_to_cpu(base->ep);
471         }
472 }
473
474 static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu,
475                                       int send)
476 {
477         if (send) {
478                 pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);
479
480                 cpu_to_be32s(&pdu->transfer_buffer_length);
481                 cpu_to_be32s(&pdu->start_frame);
482                 cpu_to_be32s(&pdu->number_of_packets);
483                 cpu_to_be32s(&pdu->interval);
484         } else {
485                 pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);
486
487                 be32_to_cpus(&pdu->transfer_buffer_length);
488                 be32_to_cpus(&pdu->start_frame);
489                 be32_to_cpus(&pdu->number_of_packets);
490                 be32_to_cpus(&pdu->interval);
491         }
492 }
493
494 static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu,
495                                       int send)
496 {
497         if (send) {
498                 cpu_to_be32s(&pdu->status);
499                 cpu_to_be32s(&pdu->actual_length);
500                 cpu_to_be32s(&pdu->start_frame);
501                 cpu_to_be32s(&pdu->number_of_packets);
502                 cpu_to_be32s(&pdu->error_count);
503         } else {
504                 be32_to_cpus(&pdu->status);
505                 be32_to_cpus(&pdu->actual_length);
506                 be32_to_cpus(&pdu->start_frame);
507                 be32_to_cpus(&pdu->number_of_packets);
508                 be32_to_cpus(&pdu->error_count);
509         }
510 }
511
512 static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu,
513                                       int send)
514 {
515         if (send)
516                 pdu->seqnum = cpu_to_be32(pdu->seqnum);
517         else
518                 pdu->seqnum = be32_to_cpu(pdu->seqnum);
519 }
520
521 static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu,
522                                       int send)
523 {
524         if (send)
525                 cpu_to_be32s(&pdu->status);
526         else
527                 be32_to_cpus(&pdu->status);
528 }
529
530 void usbip_header_correct_endian(struct usbip_header *pdu, int send)
531 {
532         __u32 cmd = 0;
533
534         if (send)
535                 cmd = pdu->base.command;
536
537         correct_endian_basic(&pdu->base, send);
538
539         if (!send)
540                 cmd = pdu->base.command;
541
542         switch (cmd) {
543         case USBIP_CMD_SUBMIT:
544                 correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
545                 break;
546         case USBIP_RET_SUBMIT:
547                 correct_endian_ret_submit(&pdu->u.ret_submit, send);
548                 break;
549         case USBIP_CMD_UNLINK:
550                 correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
551                 break;
552         case USBIP_RET_UNLINK:
553                 correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
554                 break;
555         default:
556                 /* NOT REACHED */
557                 pr_err("unknown command\n");
558                 break;
559         }
560 }
561 EXPORT_SYMBOL_GPL(usbip_header_correct_endian);
562
563 static void usbip_iso_packet_correct_endian(
564                 struct usbip_iso_packet_descriptor *iso, int send)
565 {
566         /* does not need all members. but copy all simply. */
567         if (send) {
568                 iso->offset     = cpu_to_be32(iso->offset);
569                 iso->length     = cpu_to_be32(iso->length);
570                 iso->status     = cpu_to_be32(iso->status);
571                 iso->actual_length = cpu_to_be32(iso->actual_length);
572         } else {
573                 iso->offset     = be32_to_cpu(iso->offset);
574                 iso->length     = be32_to_cpu(iso->length);
575                 iso->status     = be32_to_cpu(iso->status);
576                 iso->actual_length = be32_to_cpu(iso->actual_length);
577         }
578 }
579
580 static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
581                            struct usb_iso_packet_descriptor *uiso, int pack)
582 {
583         if (pack) {
584                 iso->offset             = uiso->offset;
585                 iso->length             = uiso->length;
586                 iso->status             = uiso->status;
587                 iso->actual_length      = uiso->actual_length;
588         } else {
589                 uiso->offset            = iso->offset;
590                 uiso->length            = iso->length;
591                 uiso->status            = iso->status;
592                 uiso->actual_length     = iso->actual_length;
593         }
594 }
595
596 /* must free buffer */
597 struct usbip_iso_packet_descriptor*
598 usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
599 {
600         struct usbip_iso_packet_descriptor *iso;
601         int np = urb->number_of_packets;
602         ssize_t size = np * sizeof(*iso);
603         int i;
604
605         iso = kzalloc(size, GFP_KERNEL);
606         if (!iso)
607                 return NULL;
608
609         for (i = 0; i < np; i++) {
610                 usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 1);
611                 usbip_iso_packet_correct_endian(&iso[i], 1);
612         }
613
614         *bufflen = size;
615
616         return iso;
617 }
618 EXPORT_SYMBOL_GPL(usbip_alloc_iso_desc_pdu);
619
620 /* some members of urb must be substituted before. */
621 int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
622 {
623         void *buff;
624         struct usbip_iso_packet_descriptor *iso;
625         int np = urb->number_of_packets;
626         int size = np * sizeof(*iso);
627         int i;
628         int ret;
629         int total_length = 0;
630
631         if (!usb_pipeisoc(urb->pipe))
632                 return 0;
633
634         /* my Bluetooth dongle gets ISO URBs which are np = 0 */
635         if (np == 0)
636                 return 0;
637
638         buff = kzalloc(size, GFP_KERNEL);
639         if (!buff)
640                 return -ENOMEM;
641
642         ret = usbip_recv(ud->tcp_socket, buff, size);
643         if (ret != size) {
644                 dev_err(&urb->dev->dev, "recv iso_frame_descriptor, %d\n",
645                         ret);
646                 kfree(buff);
647
648                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
649                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
650                 else
651                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
652
653                 return -EPIPE;
654         }
655
656         iso = (struct usbip_iso_packet_descriptor *) buff;
657         for (i = 0; i < np; i++) {
658                 usbip_iso_packet_correct_endian(&iso[i], 0);
659                 usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 0);
660                 total_length += urb->iso_frame_desc[i].actual_length;
661         }
662
663         kfree(buff);
664
665         if (total_length != urb->actual_length) {
666                 dev_err(&urb->dev->dev,
667                         "total length of iso packets %d not equal to actual length of buffer %d\n",
668                         total_length, urb->actual_length);
669
670                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
671                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
672                 else
673                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
674
675                 return -EPIPE;
676         }
677
678         return ret;
679 }
680 EXPORT_SYMBOL_GPL(usbip_recv_iso);
681
682 /*
683  * This functions restores the padding which was removed for optimizing
684  * the bandwidth during transfer over tcp/ip
685  *
686  * buffer and iso packets need to be stored and be in propeper endian in urb
687  * before calling this function
688  */
689 void usbip_pad_iso(struct usbip_device *ud, struct urb *urb)
690 {
691         int np = urb->number_of_packets;
692         int i;
693         int actualoffset = urb->actual_length;
694
695         if (!usb_pipeisoc(urb->pipe))
696                 return;
697
698         /* if no packets or length of data is 0, then nothing to unpack */
699         if (np == 0 || urb->actual_length == 0)
700                 return;
701
702         /*
703          * if actual_length is transfer_buffer_length then no padding is
704          * present.
705          */
706         if (urb->actual_length == urb->transfer_buffer_length)
707                 return;
708
709         /*
710          * loop over all packets from last to first (to prevent overwritting
711          * memory when padding) and move them into the proper place
712          */
713         for (i = np-1; i > 0; i--) {
714                 actualoffset -= urb->iso_frame_desc[i].actual_length;
715                 memmove(urb->transfer_buffer + urb->iso_frame_desc[i].offset,
716                         urb->transfer_buffer + actualoffset,
717                         urb->iso_frame_desc[i].actual_length);
718         }
719 }
720 EXPORT_SYMBOL_GPL(usbip_pad_iso);
721
722 /* some members of urb must be substituted before. */
723 int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
724 {
725         int ret;
726         int size;
727
728         if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
729                 /* the direction of urb must be OUT. */
730                 if (usb_pipein(urb->pipe))
731                         return 0;
732
733                 size = urb->transfer_buffer_length;
734         } else {
735                 /* the direction of urb must be IN. */
736                 if (usb_pipeout(urb->pipe))
737                         return 0;
738
739                 size = urb->actual_length;
740         }
741
742         /* no need to recv xbuff */
743         if (!(size > 0))
744                 return 0;
745
746         if (size > urb->transfer_buffer_length) {
747                 /* should not happen, probably malicious packet */
748                 if (ud->side == USBIP_STUB) {
749                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
750                         return 0;
751                 } else {
752                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
753                         return -EPIPE;
754                 }
755         }
756
757         ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
758         if (ret != size) {
759                 dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
760                 if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
761                         usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
762                 } else {
763                         usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
764                         return -EPIPE;
765                 }
766         }
767
768         return ret;
769 }
770 EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
771
772 static int __init usbip_core_init(void)
773 {
774         int ret;
775
776         pr_info(DRIVER_DESC " v" USBIP_VERSION "\n");
777         ret = usbip_init_eh();
778         if (ret)
779                 return ret;
780
781         return 0;
782 }
783
784 static void __exit usbip_core_exit(void)
785 {
786         usbip_finish_eh();
787         return;
788 }
789
790 module_init(usbip_core_init);
791 module_exit(usbip_core_exit);
792
793 MODULE_AUTHOR(DRIVER_AUTHOR);
794 MODULE_DESCRIPTION(DRIVER_DESC);
795 MODULE_LICENSE("GPL");
796 MODULE_VERSION(USBIP_VERSION);