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