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  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright (C) 2003-2008 Takahiro Hirofuchi
  4 * Copyright (C) 2015-2016 Samsung Electronics
  5 *               Krzysztof Opasiak <k.opasiak@samsung.com>
  6 */
  7
  8#include <asm/byteorder.h>
  9#include <linux/file.h>
 10#include <linux/fs.h>
 11#include <linux/kernel.h>
 12#include <linux/slab.h>
 13#include <linux/stat.h>
 14#include <linux/module.h>
 15#include <linux/moduleparam.h>
 16#include <net/sock.h>
 17
 18#include "usbip_common.h"
 19
 20#define DRIVER_AUTHOR "Takahiro Hirofuchi <hirofuchi@users.sourceforge.net>"
 21#define DRIVER_DESC "USB/IP Core"
 22
 23#ifdef CONFIG_USBIP_DEBUG
 24unsigned long usbip_debug_flag = 0xffffffff;
 25#else
 26unsigned long usbip_debug_flag;
 27#endif
 28EXPORT_SYMBOL_GPL(usbip_debug_flag);
 29module_param(usbip_debug_flag, ulong, S_IRUGO|S_IWUSR);
 30MODULE_PARM_DESC(usbip_debug_flag, "debug flags (defined in usbip_common.h)");
 31
 32/* FIXME */
 33struct device_attribute dev_attr_usbip_debug;
 34EXPORT_SYMBOL_GPL(dev_attr_usbip_debug);
 35
 36static 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
 42static 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}
 50DEVICE_ATTR_RW(usbip_debug);
 51
 52static 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
 58static 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
 86static 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
136static 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
157static 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
220void 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}
257EXPORT_SYMBOL_GPL(usbip_dump_urb);
258
259void 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}
299EXPORT_SYMBOL_GPL(usbip_dump_header);
300
301/* Receive data over TCP/IP. */
302int 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		if (!in_interrupt())
328			pr_debug("%-10s:", current->comm);
329		else
330			pr_debug("interrupt  :");
331
332		pr_debug("receiving....\n");
333		usbip_dump_buffer(buf, size);
334		pr_debug("received, osize %d ret %d size %zd total %d\n",
335			 size, result, msg_data_left(&msg), total);
336	}
337
338	return total;
339
340err:
341	return result;
342}
343EXPORT_SYMBOL_GPL(usbip_recv);
344
345/* there may be more cases to tweak the flags. */
346static unsigned int tweak_transfer_flags(unsigned int flags)
347{
348	flags &= ~URB_NO_TRANSFER_DMA_MAP;
349	return flags;
350}
351
352static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,
353				  int pack)
354{
355	struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;
356
357	/*
358	 * Some members are not still implemented in usbip. I hope this issue
359	 * will be discussed when usbip is ported to other operating systems.
360	 */
361	if (pack) {
362		spdu->transfer_flags =
363			tweak_transfer_flags(urb->transfer_flags);
364		spdu->transfer_buffer_length	= urb->transfer_buffer_length;
365		spdu->start_frame		= urb->start_frame;
366		spdu->number_of_packets		= urb->number_of_packets;
367		spdu->interval			= urb->interval;
368	} else  {
369		urb->transfer_flags         = spdu->transfer_flags;
370		urb->transfer_buffer_length = spdu->transfer_buffer_length;
371		urb->start_frame            = spdu->start_frame;
372		urb->number_of_packets      = spdu->number_of_packets;
373		urb->interval               = spdu->interval;
374	}
375}
376
377static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
378				  int pack)
379{
380	struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;
381
382	if (pack) {
383		rpdu->status		= urb->status;
384		rpdu->actual_length	= urb->actual_length;
385		rpdu->start_frame	= urb->start_frame;
386		rpdu->number_of_packets = urb->number_of_packets;
387		rpdu->error_count	= urb->error_count;
388	} else {
389		urb->status		= rpdu->status;
390		urb->actual_length	= rpdu->actual_length;
391		urb->start_frame	= rpdu->start_frame;
392		urb->number_of_packets = rpdu->number_of_packets;
393		urb->error_count	= rpdu->error_count;
394	}
395}
396
397void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
398		    int pack)
399{
400	switch (cmd) {
401	case USBIP_CMD_SUBMIT:
402		usbip_pack_cmd_submit(pdu, urb, pack);
403		break;
404	case USBIP_RET_SUBMIT:
405		usbip_pack_ret_submit(pdu, urb, pack);
406		break;
407	default:
408		/* NOT REACHED */
409		pr_err("unknown command\n");
410		break;
411	}
412}
413EXPORT_SYMBOL_GPL(usbip_pack_pdu);
414
415static void correct_endian_basic(struct usbip_header_basic *base, int send)
416{
417	if (send) {
418		base->command	= cpu_to_be32(base->command);
419		base->seqnum	= cpu_to_be32(base->seqnum);
420		base->devid	= cpu_to_be32(base->devid);
421		base->direction	= cpu_to_be32(base->direction);
422		base->ep	= cpu_to_be32(base->ep);
423	} else {
424		base->command	= be32_to_cpu(base->command);
425		base->seqnum	= be32_to_cpu(base->seqnum);
426		base->devid	= be32_to_cpu(base->devid);
427		base->direction	= be32_to_cpu(base->direction);
428		base->ep	= be32_to_cpu(base->ep);
429	}
430}
431
432static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu,
433				      int send)
434{
435	if (send) {
436		pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);
437
438		cpu_to_be32s(&pdu->transfer_buffer_length);
439		cpu_to_be32s(&pdu->start_frame);
440		cpu_to_be32s(&pdu->number_of_packets);
441		cpu_to_be32s(&pdu->interval);
442	} else {
443		pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);
444
445		be32_to_cpus(&pdu->transfer_buffer_length);
446		be32_to_cpus(&pdu->start_frame);
447		be32_to_cpus(&pdu->number_of_packets);
448		be32_to_cpus(&pdu->interval);
449	}
450}
451
452static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu,
453				      int send)
454{
455	if (send) {
456		cpu_to_be32s(&pdu->status);
457		cpu_to_be32s(&pdu->actual_length);
458		cpu_to_be32s(&pdu->start_frame);
459		cpu_to_be32s(&pdu->number_of_packets);
460		cpu_to_be32s(&pdu->error_count);
461	} else {
462		be32_to_cpus(&pdu->status);
463		be32_to_cpus(&pdu->actual_length);
464		be32_to_cpus(&pdu->start_frame);
465		be32_to_cpus(&pdu->number_of_packets);
466		be32_to_cpus(&pdu->error_count);
467	}
468}
469
470static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu,
471				      int send)
472{
473	if (send)
474		pdu->seqnum = cpu_to_be32(pdu->seqnum);
475	else
476		pdu->seqnum = be32_to_cpu(pdu->seqnum);
477}
478
479static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu,
480				      int send)
481{
482	if (send)
483		cpu_to_be32s(&pdu->status);
484	else
485		be32_to_cpus(&pdu->status);
486}
487
488void usbip_header_correct_endian(struct usbip_header *pdu, int send)
489{
490	__u32 cmd = 0;
491
492	if (send)
493		cmd = pdu->base.command;
494
495	correct_endian_basic(&pdu->base, send);
496
497	if (!send)
498		cmd = pdu->base.command;
499
500	switch (cmd) {
501	case USBIP_CMD_SUBMIT:
502		correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
503		break;
504	case USBIP_RET_SUBMIT:
505		correct_endian_ret_submit(&pdu->u.ret_submit, send);
506		break;
507	case USBIP_CMD_UNLINK:
508		correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
509		break;
510	case USBIP_RET_UNLINK:
511		correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
512		break;
513	default:
514		/* NOT REACHED */
515		pr_err("unknown command\n");
516		break;
517	}
518}
519EXPORT_SYMBOL_GPL(usbip_header_correct_endian);
520
521static void usbip_iso_packet_correct_endian(
522		struct usbip_iso_packet_descriptor *iso, int send)
523{
524	/* does not need all members. but copy all simply. */
525	if (send) {
526		iso->offset	= cpu_to_be32(iso->offset);
527		iso->length	= cpu_to_be32(iso->length);
528		iso->status	= cpu_to_be32(iso->status);
529		iso->actual_length = cpu_to_be32(iso->actual_length);
530	} else {
531		iso->offset	= be32_to_cpu(iso->offset);
532		iso->length	= be32_to_cpu(iso->length);
533		iso->status	= be32_to_cpu(iso->status);
534		iso->actual_length = be32_to_cpu(iso->actual_length);
535	}
536}
537
538static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
539			   struct usb_iso_packet_descriptor *uiso, int pack)
540{
541	if (pack) {
542		iso->offset		= uiso->offset;
543		iso->length		= uiso->length;
544		iso->status		= uiso->status;
545		iso->actual_length	= uiso->actual_length;
546	} else {
547		uiso->offset		= iso->offset;
548		uiso->length		= iso->length;
549		uiso->status		= iso->status;
550		uiso->actual_length	= iso->actual_length;
551	}
552}
553
554/* must free buffer */
555struct usbip_iso_packet_descriptor*
556usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
557{
558	struct usbip_iso_packet_descriptor *iso;
559	int np = urb->number_of_packets;
560	ssize_t size = np * sizeof(*iso);
561	int i;
562
563	iso = kzalloc(size, GFP_KERNEL);
564	if (!iso)
565		return NULL;
566
567	for (i = 0; i < np; i++) {
568		usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 1);
569		usbip_iso_packet_correct_endian(&iso[i], 1);
570	}
571
572	*bufflen = size;
573
574	return iso;
575}
576EXPORT_SYMBOL_GPL(usbip_alloc_iso_desc_pdu);
577
578/* some members of urb must be substituted before. */
579int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
580{
581	void *buff;
582	struct usbip_iso_packet_descriptor *iso;
583	int np = urb->number_of_packets;
584	int size = np * sizeof(*iso);
585	int i;
586	int ret;
587	int total_length = 0;
588
589	if (!usb_pipeisoc(urb->pipe))
590		return 0;
591
592	/* my Bluetooth dongle gets ISO URBs which are np = 0 */
593	if (np == 0)
594		return 0;
595
596	buff = kzalloc(size, GFP_KERNEL);
597	if (!buff)
598		return -ENOMEM;
599
600	ret = usbip_recv(ud->tcp_socket, buff, size);
601	if (ret != size) {
602		dev_err(&urb->dev->dev, "recv iso_frame_descriptor, %d\n",
603			ret);
604		kfree(buff);
605
606		if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
607			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
608		else
609			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
610
611		return -EPIPE;
612	}
613
614	iso = (struct usbip_iso_packet_descriptor *) buff;
615	for (i = 0; i < np; i++) {
616		usbip_iso_packet_correct_endian(&iso[i], 0);
617		usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 0);
618		total_length += urb->iso_frame_desc[i].actual_length;
619	}
620
621	kfree(buff);
622
623	if (total_length != urb->actual_length) {
624		dev_err(&urb->dev->dev,
625			"total length of iso packets %d not equal to actual length of buffer %d\n",
626			total_length, urb->actual_length);
627
628		if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
629			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
630		else
631			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
632
633		return -EPIPE;
634	}
635
636	return ret;
637}
638EXPORT_SYMBOL_GPL(usbip_recv_iso);
639
640/*
641 * This functions restores the padding which was removed for optimizing
642 * the bandwidth during transfer over tcp/ip
643 *
644 * buffer and iso packets need to be stored and be in propeper endian in urb
645 * before calling this function
646 */
647void usbip_pad_iso(struct usbip_device *ud, struct urb *urb)
648{
649	int np = urb->number_of_packets;
650	int i;
651	int actualoffset = urb->actual_length;
652
653	if (!usb_pipeisoc(urb->pipe))
654		return;
655
656	/* if no packets or length of data is 0, then nothing to unpack */
657	if (np == 0 || urb->actual_length == 0)
658		return;
659
660	/*
661	 * if actual_length is transfer_buffer_length then no padding is
662	 * present.
663	 */
664	if (urb->actual_length == urb->transfer_buffer_length)
665		return;
666
667	/*
668	 * loop over all packets from last to first (to prevent overwriting
669	 * memory when padding) and move them into the proper place
670	 */
671	for (i = np-1; i > 0; i--) {
672		actualoffset -= urb->iso_frame_desc[i].actual_length;
673		memmove(urb->transfer_buffer + urb->iso_frame_desc[i].offset,
674			urb->transfer_buffer + actualoffset,
675			urb->iso_frame_desc[i].actual_length);
676	}
677}
678EXPORT_SYMBOL_GPL(usbip_pad_iso);
679
680/* some members of urb must be substituted before. */
681int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
682{
683	struct scatterlist *sg;
684	int ret = 0;
685	int recv;
686	int size;
687	int copy;
688	int i;
689
690	if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
691		/* the direction of urb must be OUT. */
692		if (usb_pipein(urb->pipe))
693			return 0;
694
695		size = urb->transfer_buffer_length;
696	} else {
697		/* the direction of urb must be IN. */
698		if (usb_pipeout(urb->pipe))
699			return 0;
700
701		size = urb->actual_length;
702	}
703
704	/* no need to recv xbuff */
705	if (!(size > 0))
706		return 0;
707
708	if (size > urb->transfer_buffer_length)
709		/* should not happen, probably malicious packet */
710		goto error;
711
712	if (urb->num_sgs) {
713		copy = size;
714		for_each_sg(urb->sg, sg, urb->num_sgs, i) {
715			int recv_size;
716
717			if (copy < sg->length)
718				recv_size = copy;
719			else
720				recv_size = sg->length;
721
722			recv = usbip_recv(ud->tcp_socket, sg_virt(sg),
723						recv_size);
724
725			if (recv != recv_size)
726				goto error;
727
728			copy -= recv;
729			ret += recv;
730
731			if (!copy)
732				break;
733		}
734
735		if (ret != size)
736			goto error;
737	} else {
738		ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
739		if (ret != size)
740			goto error;
741	}
742
743	return ret;
744
745error:
746	dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
747	if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
748		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
749	else
750		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
751
752	return -EPIPE;
753}
754EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
755
756static int __init usbip_core_init(void)
757{
758	int ret;
759
760	ret = usbip_init_eh();
761	if (ret)
762		return ret;
763
764	return 0;
765}
766
767static void __exit usbip_core_exit(void)
768{
769	usbip_finish_eh();
770	return;
771}
772
773module_init(usbip_core_init);
774module_exit(usbip_core_exit);
775
776MODULE_AUTHOR(DRIVER_AUTHOR);
777MODULE_DESCRIPTION(DRIVER_DESC);
778MODULE_LICENSE("GPL");