xref: /openbmc/linux/drivers/usb/usbip/usbip_common.c (revision bbecb07f)
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
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 %p, ttport %d\n", udev->tt, 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 %p, bus %p\n", udev->parent, udev->bus);
128 
129 	dev_dbg(dev,
130 		"descriptor %p, config %p, actconfig %p, rawdescriptors %p\n",
131 		&udev->descriptor, udev->config,
132 		udev->actconfig, udev->rawdescriptors);
133 
134 	dev_dbg(dev, "have_langid %d, string_langid %d\n",
135 		udev->have_langid, udev->string_langid);
136 
137 	dev_dbg(dev, "maxchild %d\n", udev->maxchild);
138 }
139 
140 static void usbip_dump_request_type(__u8 rt)
141 {
142 	switch (rt & USB_RECIP_MASK) {
143 	case USB_RECIP_DEVICE:
144 		pr_debug("DEVICE");
145 		break;
146 	case USB_RECIP_INTERFACE:
147 		pr_debug("INTERF");
148 		break;
149 	case USB_RECIP_ENDPOINT:
150 		pr_debug("ENDPOI");
151 		break;
152 	case USB_RECIP_OTHER:
153 		pr_debug("OTHER ");
154 		break;
155 	default:
156 		pr_debug("------");
157 		break;
158 	}
159 }
160 
161 static void usbip_dump_usb_ctrlrequest(struct usb_ctrlrequest *cmd)
162 {
163 	if (!cmd) {
164 		pr_debug("       : null pointer\n");
165 		return;
166 	}
167 
168 	pr_debug("       ");
169 	pr_debug("bRequestType(%02X) bRequest(%02X) wValue(%04X) wIndex(%04X) wLength(%04X) ",
170 		 cmd->bRequestType, cmd->bRequest,
171 		 cmd->wValue, cmd->wIndex, cmd->wLength);
172 	pr_debug("\n       ");
173 
174 	if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
175 		pr_debug("STANDARD ");
176 		switch (cmd->bRequest) {
177 		case USB_REQ_GET_STATUS:
178 			pr_debug("GET_STATUS\n");
179 			break;
180 		case USB_REQ_CLEAR_FEATURE:
181 			pr_debug("CLEAR_FEAT\n");
182 			break;
183 		case USB_REQ_SET_FEATURE:
184 			pr_debug("SET_FEAT\n");
185 			break;
186 		case USB_REQ_SET_ADDRESS:
187 			pr_debug("SET_ADDRRS\n");
188 			break;
189 		case USB_REQ_GET_DESCRIPTOR:
190 			pr_debug("GET_DESCRI\n");
191 			break;
192 		case USB_REQ_SET_DESCRIPTOR:
193 			pr_debug("SET_DESCRI\n");
194 			break;
195 		case USB_REQ_GET_CONFIGURATION:
196 			pr_debug("GET_CONFIG\n");
197 			break;
198 		case USB_REQ_SET_CONFIGURATION:
199 			pr_debug("SET_CONFIG\n");
200 			break;
201 		case USB_REQ_GET_INTERFACE:
202 			pr_debug("GET_INTERF\n");
203 			break;
204 		case USB_REQ_SET_INTERFACE:
205 			pr_debug("SET_INTERF\n");
206 			break;
207 		case USB_REQ_SYNCH_FRAME:
208 			pr_debug("SYNC_FRAME\n");
209 			break;
210 		default:
211 			pr_debug("REQ(%02X)\n", cmd->bRequest);
212 			break;
213 		}
214 		usbip_dump_request_type(cmd->bRequestType);
215 	} else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS) {
216 		pr_debug("CLASS\n");
217 	} else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_VENDOR) {
218 		pr_debug("VENDOR\n");
219 	} else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_RESERVED) {
220 		pr_debug("RESERVED\n");
221 	}
222 }
223 
224 void usbip_dump_urb(struct urb *urb)
225 {
226 	struct device *dev;
227 
228 	if (!urb) {
229 		pr_debug("urb: null pointer!!\n");
230 		return;
231 	}
232 
233 	if (!urb->dev) {
234 		pr_debug("urb->dev: null pointer!!\n");
235 		return;
236 	}
237 
238 	dev = &urb->dev->dev;
239 
240 	dev_dbg(dev, "   urb                   :%p\n", urb);
241 	dev_dbg(dev, "   dev                   :%p\n", urb->dev);
242 
243 	usbip_dump_usb_device(urb->dev);
244 
245 	dev_dbg(dev, "   pipe                  :%08x ", urb->pipe);
246 
247 	usbip_dump_pipe(urb->pipe);
248 
249 	dev_dbg(dev, "   status                :%d\n", urb->status);
250 	dev_dbg(dev, "   transfer_flags        :%08X\n", urb->transfer_flags);
251 	dev_dbg(dev, "   transfer_buffer       :%p\n", urb->transfer_buffer);
252 	dev_dbg(dev, "   transfer_buffer_length:%d\n",
253 						urb->transfer_buffer_length);
254 	dev_dbg(dev, "   actual_length         :%d\n", urb->actual_length);
255 	dev_dbg(dev, "   setup_packet          :%p\n", urb->setup_packet);
256 
257 	if (urb->setup_packet && usb_pipetype(urb->pipe) == PIPE_CONTROL)
258 		usbip_dump_usb_ctrlrequest(
259 			(struct usb_ctrlrequest *)urb->setup_packet);
260 
261 	dev_dbg(dev, "   start_frame           :%d\n", urb->start_frame);
262 	dev_dbg(dev, "   number_of_packets     :%d\n", urb->number_of_packets);
263 	dev_dbg(dev, "   interval              :%d\n", urb->interval);
264 	dev_dbg(dev, "   error_count           :%d\n", urb->error_count);
265 	dev_dbg(dev, "   context               :%p\n", urb->context);
266 	dev_dbg(dev, "   complete              :%p\n", urb->complete);
267 }
268 EXPORT_SYMBOL_GPL(usbip_dump_urb);
269 
270 void usbip_dump_header(struct usbip_header *pdu)
271 {
272 	pr_debug("BASE: cmd %u seq %u devid %u dir %u ep %u\n",
273 		 pdu->base.command,
274 		 pdu->base.seqnum,
275 		 pdu->base.devid,
276 		 pdu->base.direction,
277 		 pdu->base.ep);
278 
279 	switch (pdu->base.command) {
280 	case USBIP_CMD_SUBMIT:
281 		pr_debug("USBIP_CMD_SUBMIT: x_flags %u x_len %u sf %u #p %d iv %d\n",
282 			 pdu->u.cmd_submit.transfer_flags,
283 			 pdu->u.cmd_submit.transfer_buffer_length,
284 			 pdu->u.cmd_submit.start_frame,
285 			 pdu->u.cmd_submit.number_of_packets,
286 			 pdu->u.cmd_submit.interval);
287 		break;
288 	case USBIP_CMD_UNLINK:
289 		pr_debug("USBIP_CMD_UNLINK: seq %u\n",
290 			 pdu->u.cmd_unlink.seqnum);
291 		break;
292 	case USBIP_RET_SUBMIT:
293 		pr_debug("USBIP_RET_SUBMIT: st %d al %u sf %d #p %d ec %d\n",
294 			 pdu->u.ret_submit.status,
295 			 pdu->u.ret_submit.actual_length,
296 			 pdu->u.ret_submit.start_frame,
297 			 pdu->u.ret_submit.number_of_packets,
298 			 pdu->u.ret_submit.error_count);
299 		break;
300 	case USBIP_RET_UNLINK:
301 		pr_debug("USBIP_RET_UNLINK: status %d\n",
302 			 pdu->u.ret_unlink.status);
303 		break;
304 	default:
305 		/* NOT REACHED */
306 		pr_err("unknown command\n");
307 		break;
308 	}
309 }
310 EXPORT_SYMBOL_GPL(usbip_dump_header);
311 
312 /* Receive data over TCP/IP. */
313 int usbip_recv(struct socket *sock, void *buf, int size)
314 {
315 	int result;
316 	struct kvec iov = {.iov_base = buf, .iov_len = size};
317 	struct msghdr msg = {.msg_flags = MSG_NOSIGNAL};
318 	int total = 0;
319 
320 	iov_iter_kvec(&msg.msg_iter, READ|ITER_KVEC, &iov, 1, size);
321 
322 	usbip_dbg_xmit("enter\n");
323 
324 	if (!sock || !buf || !size) {
325 		pr_err("invalid arg, sock %p buff %p size %d\n", sock, buf,
326 		       size);
327 		return -EINVAL;
328 	}
329 
330 	do {
331 		int sz = msg_data_left(&msg);
332 		sock->sk->sk_allocation = GFP_NOIO;
333 
334 		result = sock_recvmsg(sock, &msg, MSG_WAITALL);
335 		if (result <= 0) {
336 			pr_debug("receive sock %p buf %p size %u ret %d total %d\n",
337 				 sock, buf + total, sz, result, total);
338 			goto err;
339 		}
340 
341 		total += result;
342 	} while (msg_data_left(&msg));
343 
344 	if (usbip_dbg_flag_xmit) {
345 		if (!in_interrupt())
346 			pr_debug("%-10s:", current->comm);
347 		else
348 			pr_debug("interrupt  :");
349 
350 		pr_debug("receiving....\n");
351 		usbip_dump_buffer(buf, size);
352 		pr_debug("received, osize %d ret %d size %zd total %d\n",
353 			 size, result, msg_data_left(&msg), total);
354 	}
355 
356 	return total;
357 
358 err:
359 	return result;
360 }
361 EXPORT_SYMBOL_GPL(usbip_recv);
362 
363 /* there may be more cases to tweak the flags. */
364 static unsigned int tweak_transfer_flags(unsigned int flags)
365 {
366 	flags &= ~URB_NO_TRANSFER_DMA_MAP;
367 	return flags;
368 }
369 
370 static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,
371 				  int pack)
372 {
373 	struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;
374 
375 	/*
376 	 * Some members are not still implemented in usbip. I hope this issue
377 	 * will be discussed when usbip is ported to other operating systems.
378 	 */
379 	if (pack) {
380 		spdu->transfer_flags =
381 			tweak_transfer_flags(urb->transfer_flags);
382 		spdu->transfer_buffer_length	= urb->transfer_buffer_length;
383 		spdu->start_frame		= urb->start_frame;
384 		spdu->number_of_packets		= urb->number_of_packets;
385 		spdu->interval			= urb->interval;
386 	} else  {
387 		urb->transfer_flags         = spdu->transfer_flags;
388 		urb->transfer_buffer_length = spdu->transfer_buffer_length;
389 		urb->start_frame            = spdu->start_frame;
390 		urb->number_of_packets      = spdu->number_of_packets;
391 		urb->interval               = spdu->interval;
392 	}
393 }
394 
395 static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
396 				  int pack)
397 {
398 	struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;
399 
400 	if (pack) {
401 		rpdu->status		= urb->status;
402 		rpdu->actual_length	= urb->actual_length;
403 		rpdu->start_frame	= urb->start_frame;
404 		rpdu->number_of_packets = urb->number_of_packets;
405 		rpdu->error_count	= urb->error_count;
406 	} else {
407 		urb->status		= rpdu->status;
408 		urb->actual_length	= rpdu->actual_length;
409 		urb->start_frame	= rpdu->start_frame;
410 		urb->number_of_packets = rpdu->number_of_packets;
411 		urb->error_count	= rpdu->error_count;
412 	}
413 }
414 
415 void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
416 		    int pack)
417 {
418 	switch (cmd) {
419 	case USBIP_CMD_SUBMIT:
420 		usbip_pack_cmd_submit(pdu, urb, pack);
421 		break;
422 	case USBIP_RET_SUBMIT:
423 		usbip_pack_ret_submit(pdu, urb, pack);
424 		break;
425 	default:
426 		/* NOT REACHED */
427 		pr_err("unknown command\n");
428 		break;
429 	}
430 }
431 EXPORT_SYMBOL_GPL(usbip_pack_pdu);
432 
433 static void correct_endian_basic(struct usbip_header_basic *base, int send)
434 {
435 	if (send) {
436 		base->command	= cpu_to_be32(base->command);
437 		base->seqnum	= cpu_to_be32(base->seqnum);
438 		base->devid	= cpu_to_be32(base->devid);
439 		base->direction	= cpu_to_be32(base->direction);
440 		base->ep	= cpu_to_be32(base->ep);
441 	} else {
442 		base->command	= be32_to_cpu(base->command);
443 		base->seqnum	= be32_to_cpu(base->seqnum);
444 		base->devid	= be32_to_cpu(base->devid);
445 		base->direction	= be32_to_cpu(base->direction);
446 		base->ep	= be32_to_cpu(base->ep);
447 	}
448 }
449 
450 static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu,
451 				      int send)
452 {
453 	if (send) {
454 		pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);
455 
456 		cpu_to_be32s(&pdu->transfer_buffer_length);
457 		cpu_to_be32s(&pdu->start_frame);
458 		cpu_to_be32s(&pdu->number_of_packets);
459 		cpu_to_be32s(&pdu->interval);
460 	} else {
461 		pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);
462 
463 		be32_to_cpus(&pdu->transfer_buffer_length);
464 		be32_to_cpus(&pdu->start_frame);
465 		be32_to_cpus(&pdu->number_of_packets);
466 		be32_to_cpus(&pdu->interval);
467 	}
468 }
469 
470 static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu,
471 				      int send)
472 {
473 	if (send) {
474 		cpu_to_be32s(&pdu->status);
475 		cpu_to_be32s(&pdu->actual_length);
476 		cpu_to_be32s(&pdu->start_frame);
477 		cpu_to_be32s(&pdu->number_of_packets);
478 		cpu_to_be32s(&pdu->error_count);
479 	} else {
480 		be32_to_cpus(&pdu->status);
481 		be32_to_cpus(&pdu->actual_length);
482 		be32_to_cpus(&pdu->start_frame);
483 		be32_to_cpus(&pdu->number_of_packets);
484 		be32_to_cpus(&pdu->error_count);
485 	}
486 }
487 
488 static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu,
489 				      int send)
490 {
491 	if (send)
492 		pdu->seqnum = cpu_to_be32(pdu->seqnum);
493 	else
494 		pdu->seqnum = be32_to_cpu(pdu->seqnum);
495 }
496 
497 static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu,
498 				      int send)
499 {
500 	if (send)
501 		cpu_to_be32s(&pdu->status);
502 	else
503 		be32_to_cpus(&pdu->status);
504 }
505 
506 void usbip_header_correct_endian(struct usbip_header *pdu, int send)
507 {
508 	__u32 cmd = 0;
509 
510 	if (send)
511 		cmd = pdu->base.command;
512 
513 	correct_endian_basic(&pdu->base, send);
514 
515 	if (!send)
516 		cmd = pdu->base.command;
517 
518 	switch (cmd) {
519 	case USBIP_CMD_SUBMIT:
520 		correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
521 		break;
522 	case USBIP_RET_SUBMIT:
523 		correct_endian_ret_submit(&pdu->u.ret_submit, send);
524 		break;
525 	case USBIP_CMD_UNLINK:
526 		correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
527 		break;
528 	case USBIP_RET_UNLINK:
529 		correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
530 		break;
531 	default:
532 		/* NOT REACHED */
533 		pr_err("unknown command\n");
534 		break;
535 	}
536 }
537 EXPORT_SYMBOL_GPL(usbip_header_correct_endian);
538 
539 static void usbip_iso_packet_correct_endian(
540 		struct usbip_iso_packet_descriptor *iso, int send)
541 {
542 	/* does not need all members. but copy all simply. */
543 	if (send) {
544 		iso->offset	= cpu_to_be32(iso->offset);
545 		iso->length	= cpu_to_be32(iso->length);
546 		iso->status	= cpu_to_be32(iso->status);
547 		iso->actual_length = cpu_to_be32(iso->actual_length);
548 	} else {
549 		iso->offset	= be32_to_cpu(iso->offset);
550 		iso->length	= be32_to_cpu(iso->length);
551 		iso->status	= be32_to_cpu(iso->status);
552 		iso->actual_length = be32_to_cpu(iso->actual_length);
553 	}
554 }
555 
556 static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
557 			   struct usb_iso_packet_descriptor *uiso, int pack)
558 {
559 	if (pack) {
560 		iso->offset		= uiso->offset;
561 		iso->length		= uiso->length;
562 		iso->status		= uiso->status;
563 		iso->actual_length	= uiso->actual_length;
564 	} else {
565 		uiso->offset		= iso->offset;
566 		uiso->length		= iso->length;
567 		uiso->status		= iso->status;
568 		uiso->actual_length	= iso->actual_length;
569 	}
570 }
571 
572 /* must free buffer */
573 struct usbip_iso_packet_descriptor*
574 usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
575 {
576 	struct usbip_iso_packet_descriptor *iso;
577 	int np = urb->number_of_packets;
578 	ssize_t size = np * sizeof(*iso);
579 	int i;
580 
581 	iso = kzalloc(size, GFP_KERNEL);
582 	if (!iso)
583 		return NULL;
584 
585 	for (i = 0; i < np; i++) {
586 		usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 1);
587 		usbip_iso_packet_correct_endian(&iso[i], 1);
588 	}
589 
590 	*bufflen = size;
591 
592 	return iso;
593 }
594 EXPORT_SYMBOL_GPL(usbip_alloc_iso_desc_pdu);
595 
596 /* some members of urb must be substituted before. */
597 int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
598 {
599 	void *buff;
600 	struct usbip_iso_packet_descriptor *iso;
601 	int np = urb->number_of_packets;
602 	int size = np * sizeof(*iso);
603 	int i;
604 	int ret;
605 	int total_length = 0;
606 
607 	if (!usb_pipeisoc(urb->pipe))
608 		return 0;
609 
610 	/* my Bluetooth dongle gets ISO URBs which are np = 0 */
611 	if (np == 0)
612 		return 0;
613 
614 	buff = kzalloc(size, GFP_KERNEL);
615 	if (!buff)
616 		return -ENOMEM;
617 
618 	ret = usbip_recv(ud->tcp_socket, buff, size);
619 	if (ret != size) {
620 		dev_err(&urb->dev->dev, "recv iso_frame_descriptor, %d\n",
621 			ret);
622 		kfree(buff);
623 
624 		if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
625 			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
626 		else
627 			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
628 
629 		return -EPIPE;
630 	}
631 
632 	iso = (struct usbip_iso_packet_descriptor *) buff;
633 	for (i = 0; i < np; i++) {
634 		usbip_iso_packet_correct_endian(&iso[i], 0);
635 		usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 0);
636 		total_length += urb->iso_frame_desc[i].actual_length;
637 	}
638 
639 	kfree(buff);
640 
641 	if (total_length != urb->actual_length) {
642 		dev_err(&urb->dev->dev,
643 			"total length of iso packets %d not equal to actual length of buffer %d\n",
644 			total_length, urb->actual_length);
645 
646 		if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
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 	return ret;
655 }
656 EXPORT_SYMBOL_GPL(usbip_recv_iso);
657 
658 /*
659  * This functions restores the padding which was removed for optimizing
660  * the bandwidth during transfer over tcp/ip
661  *
662  * buffer and iso packets need to be stored and be in propeper endian in urb
663  * before calling this function
664  */
665 void usbip_pad_iso(struct usbip_device *ud, struct urb *urb)
666 {
667 	int np = urb->number_of_packets;
668 	int i;
669 	int actualoffset = urb->actual_length;
670 
671 	if (!usb_pipeisoc(urb->pipe))
672 		return;
673 
674 	/* if no packets or length of data is 0, then nothing to unpack */
675 	if (np == 0 || urb->actual_length == 0)
676 		return;
677 
678 	/*
679 	 * if actual_length is transfer_buffer_length then no padding is
680 	 * present.
681 	 */
682 	if (urb->actual_length == urb->transfer_buffer_length)
683 		return;
684 
685 	/*
686 	 * loop over all packets from last to first (to prevent overwriting
687 	 * memory when padding) and move them into the proper place
688 	 */
689 	for (i = np-1; i > 0; i--) {
690 		actualoffset -= urb->iso_frame_desc[i].actual_length;
691 		memmove(urb->transfer_buffer + urb->iso_frame_desc[i].offset,
692 			urb->transfer_buffer + actualoffset,
693 			urb->iso_frame_desc[i].actual_length);
694 	}
695 }
696 EXPORT_SYMBOL_GPL(usbip_pad_iso);
697 
698 /* some members of urb must be substituted before. */
699 int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
700 {
701 	int ret;
702 	int size;
703 
704 	if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
705 		/* the direction of urb must be OUT. */
706 		if (usb_pipein(urb->pipe))
707 			return 0;
708 
709 		size = urb->transfer_buffer_length;
710 	} else {
711 		/* the direction of urb must be IN. */
712 		if (usb_pipeout(urb->pipe))
713 			return 0;
714 
715 		size = urb->actual_length;
716 	}
717 
718 	/* no need to recv xbuff */
719 	if (!(size > 0))
720 		return 0;
721 
722 	if (size > urb->transfer_buffer_length) {
723 		/* should not happen, probably malicious packet */
724 		if (ud->side == USBIP_STUB) {
725 			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
726 			return 0;
727 		} else {
728 			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
729 			return -EPIPE;
730 		}
731 	}
732 
733 	ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
734 	if (ret != size) {
735 		dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
736 		if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
737 			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
738 		} else {
739 			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
740 			return -EPIPE;
741 		}
742 	}
743 
744 	return ret;
745 }
746 EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
747 
748 static int __init usbip_core_init(void)
749 {
750 	int ret;
751 
752 	ret = usbip_init_eh();
753 	if (ret)
754 		return ret;
755 
756 	return 0;
757 }
758 
759 static void __exit usbip_core_exit(void)
760 {
761 	usbip_finish_eh();
762 	return;
763 }
764 
765 module_init(usbip_core_init);
766 module_exit(usbip_core_exit);
767 
768 MODULE_AUTHOR(DRIVER_AUTHOR);
769 MODULE_DESCRIPTION(DRIVER_DESC);
770 MODULE_LICENSE("GPL");
771