xref: /openbmc/linux/drivers/usb/usbip/usbip_common.c (revision 22b6e7f3)
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 hub ttport %d\n", udev->ttport);
95 
96 	dev_dbg(dev, "                    ");
97 	for (i = 0; i < 16; i++)
98 		pr_debug(" %2u", i);
99 	pr_debug("\n");
100 
101 	dev_dbg(dev, "       toggle0(IN) :");
102 	for (i = 0; i < 16; i++)
103 		pr_debug(" %2u", (udev->toggle[0] & (1 << i)) ? 1 : 0);
104 	pr_debug("\n");
105 
106 	dev_dbg(dev, "       toggle1(OUT):");
107 	for (i = 0; i < 16; i++)
108 		pr_debug(" %2u", (udev->toggle[1] & (1 << i)) ? 1 : 0);
109 	pr_debug("\n");
110 
111 	dev_dbg(dev, "       epmaxp_in   :");
112 	for (i = 0; i < 16; i++) {
113 		if (udev->ep_in[i])
114 			pr_debug(" %2u",
115 			    le16_to_cpu(udev->ep_in[i]->desc.wMaxPacketSize));
116 	}
117 	pr_debug("\n");
118 
119 	dev_dbg(dev, "       epmaxp_out  :");
120 	for (i = 0; i < 16; i++) {
121 		if (udev->ep_out[i])
122 			pr_debug(" %2u",
123 			    le16_to_cpu(udev->ep_out[i]->desc.wMaxPacketSize));
124 	}
125 	pr_debug("\n");
126 
127 	dev_dbg(dev, "parent %s, bus %s\n", dev_name(&udev->parent->dev),
128 		udev->bus->bus_name);
129 
130 	dev_dbg(dev, "have_langid %d, string_langid %d\n",
131 		udev->have_langid, udev->string_langid);
132 
133 	dev_dbg(dev, "maxchild %d\n", udev->maxchild);
134 }
135 
136 static void usbip_dump_request_type(__u8 rt)
137 {
138 	switch (rt & USB_RECIP_MASK) {
139 	case USB_RECIP_DEVICE:
140 		pr_debug("DEVICE");
141 		break;
142 	case USB_RECIP_INTERFACE:
143 		pr_debug("INTERF");
144 		break;
145 	case USB_RECIP_ENDPOINT:
146 		pr_debug("ENDPOI");
147 		break;
148 	case USB_RECIP_OTHER:
149 		pr_debug("OTHER ");
150 		break;
151 	default:
152 		pr_debug("------");
153 		break;
154 	}
155 }
156 
157 static void usbip_dump_usb_ctrlrequest(struct usb_ctrlrequest *cmd)
158 {
159 	if (!cmd) {
160 		pr_debug("       : null pointer\n");
161 		return;
162 	}
163 
164 	pr_debug("       ");
165 	pr_debug("bRequestType(%02X) bRequest(%02X) wValue(%04X) wIndex(%04X) wLength(%04X) ",
166 		 cmd->bRequestType, cmd->bRequest,
167 		 cmd->wValue, cmd->wIndex, cmd->wLength);
168 	pr_debug("\n       ");
169 
170 	if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
171 		pr_debug("STANDARD ");
172 		switch (cmd->bRequest) {
173 		case USB_REQ_GET_STATUS:
174 			pr_debug("GET_STATUS\n");
175 			break;
176 		case USB_REQ_CLEAR_FEATURE:
177 			pr_debug("CLEAR_FEAT\n");
178 			break;
179 		case USB_REQ_SET_FEATURE:
180 			pr_debug("SET_FEAT\n");
181 			break;
182 		case USB_REQ_SET_ADDRESS:
183 			pr_debug("SET_ADDRRS\n");
184 			break;
185 		case USB_REQ_GET_DESCRIPTOR:
186 			pr_debug("GET_DESCRI\n");
187 			break;
188 		case USB_REQ_SET_DESCRIPTOR:
189 			pr_debug("SET_DESCRI\n");
190 			break;
191 		case USB_REQ_GET_CONFIGURATION:
192 			pr_debug("GET_CONFIG\n");
193 			break;
194 		case USB_REQ_SET_CONFIGURATION:
195 			pr_debug("SET_CONFIG\n");
196 			break;
197 		case USB_REQ_GET_INTERFACE:
198 			pr_debug("GET_INTERF\n");
199 			break;
200 		case USB_REQ_SET_INTERFACE:
201 			pr_debug("SET_INTERF\n");
202 			break;
203 		case USB_REQ_SYNCH_FRAME:
204 			pr_debug("SYNC_FRAME\n");
205 			break;
206 		default:
207 			pr_debug("REQ(%02X)\n", cmd->bRequest);
208 			break;
209 		}
210 		usbip_dump_request_type(cmd->bRequestType);
211 	} else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS) {
212 		pr_debug("CLASS\n");
213 	} else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_VENDOR) {
214 		pr_debug("VENDOR\n");
215 	} else if ((cmd->bRequestType & USB_TYPE_MASK) == USB_TYPE_RESERVED) {
216 		pr_debug("RESERVED\n");
217 	}
218 }
219 
220 void usbip_dump_urb(struct urb *urb)
221 {
222 	struct device *dev;
223 
224 	if (!urb) {
225 		pr_debug("urb: null pointer!!\n");
226 		return;
227 	}
228 
229 	if (!urb->dev) {
230 		pr_debug("urb->dev: null pointer!!\n");
231 		return;
232 	}
233 
234 	dev = &urb->dev->dev;
235 
236 	usbip_dump_usb_device(urb->dev);
237 
238 	dev_dbg(dev, "   pipe                  :%08x ", urb->pipe);
239 
240 	usbip_dump_pipe(urb->pipe);
241 
242 	dev_dbg(dev, "   status                :%d\n", urb->status);
243 	dev_dbg(dev, "   transfer_flags        :%08X\n", urb->transfer_flags);
244 	dev_dbg(dev, "   transfer_buffer_length:%d\n",
245 						urb->transfer_buffer_length);
246 	dev_dbg(dev, "   actual_length         :%d\n", urb->actual_length);
247 
248 	if (urb->setup_packet && usb_pipetype(urb->pipe) == PIPE_CONTROL)
249 		usbip_dump_usb_ctrlrequest(
250 			(struct usb_ctrlrequest *)urb->setup_packet);
251 
252 	dev_dbg(dev, "   start_frame           :%d\n", urb->start_frame);
253 	dev_dbg(dev, "   number_of_packets     :%d\n", urb->number_of_packets);
254 	dev_dbg(dev, "   interval              :%d\n", urb->interval);
255 	dev_dbg(dev, "   error_count           :%d\n", urb->error_count);
256 }
257 EXPORT_SYMBOL_GPL(usbip_dump_urb);
258 
259 void usbip_dump_header(struct usbip_header *pdu)
260 {
261 	pr_debug("BASE: cmd %u seq %u devid %u dir %u ep %u\n",
262 		 pdu->base.command,
263 		 pdu->base.seqnum,
264 		 pdu->base.devid,
265 		 pdu->base.direction,
266 		 pdu->base.ep);
267 
268 	switch (pdu->base.command) {
269 	case USBIP_CMD_SUBMIT:
270 		pr_debug("USBIP_CMD_SUBMIT: x_flags %u x_len %u sf %u #p %d iv %d\n",
271 			 pdu->u.cmd_submit.transfer_flags,
272 			 pdu->u.cmd_submit.transfer_buffer_length,
273 			 pdu->u.cmd_submit.start_frame,
274 			 pdu->u.cmd_submit.number_of_packets,
275 			 pdu->u.cmd_submit.interval);
276 		break;
277 	case USBIP_CMD_UNLINK:
278 		pr_debug("USBIP_CMD_UNLINK: seq %u\n",
279 			 pdu->u.cmd_unlink.seqnum);
280 		break;
281 	case USBIP_RET_SUBMIT:
282 		pr_debug("USBIP_RET_SUBMIT: st %d al %u sf %d #p %d ec %d\n",
283 			 pdu->u.ret_submit.status,
284 			 pdu->u.ret_submit.actual_length,
285 			 pdu->u.ret_submit.start_frame,
286 			 pdu->u.ret_submit.number_of_packets,
287 			 pdu->u.ret_submit.error_count);
288 		break;
289 	case USBIP_RET_UNLINK:
290 		pr_debug("USBIP_RET_UNLINK: status %d\n",
291 			 pdu->u.ret_unlink.status);
292 		break;
293 	default:
294 		/* NOT REACHED */
295 		pr_err("unknown command\n");
296 		break;
297 	}
298 }
299 EXPORT_SYMBOL_GPL(usbip_dump_header);
300 
301 /* Receive data over TCP/IP. */
302 int usbip_recv(struct socket *sock, void *buf, int size)
303 {
304 	int result;
305 	struct kvec iov = {.iov_base = buf, .iov_len = size};
306 	struct msghdr msg = {.msg_flags = MSG_NOSIGNAL};
307 	int total = 0;
308 
309 	if (!sock || !buf || !size)
310 		return -EINVAL;
311 
312 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, size);
313 
314 	usbip_dbg_xmit("enter\n");
315 
316 	do {
317 		sock->sk->sk_allocation = GFP_NOIO;
318 		sock->sk->sk_use_task_frag = false;
319 
320 		result = sock_recvmsg(sock, &msg, MSG_WAITALL);
321 		if (result <= 0)
322 			goto err;
323 
324 		total += result;
325 	} while (msg_data_left(&msg));
326 
327 	if (usbip_dbg_flag_xmit) {
328 		pr_debug("receiving....\n");
329 		usbip_dump_buffer(buf, size);
330 		pr_debug("received, osize %d ret %d size %zd total %d\n",
331 			 size, result, msg_data_left(&msg), total);
332 	}
333 
334 	return total;
335 
336 err:
337 	return result;
338 }
339 EXPORT_SYMBOL_GPL(usbip_recv);
340 
341 /* there may be more cases to tweak the flags. */
342 static unsigned int tweak_transfer_flags(unsigned int flags)
343 {
344 	flags &= ~URB_NO_TRANSFER_DMA_MAP;
345 	return flags;
346 }
347 
348 /*
349  * USBIP driver packs URB transfer flags in PDUs that are exchanged
350  * between Server (usbip_host) and Client (vhci_hcd). URB_* flags
351  * are internal to kernel and could change. Where as USBIP URB flags
352  * exchanged in PDUs are USBIP user API must not change.
353  *
354  * USBIP_URB* flags are exported as explicit API and client and server
355  * do mapping from kernel flags to USBIP_URB*. Details as follows:
356  *
357  * Client tx path (USBIP_CMD_SUBMIT):
358  * - Maps URB_* to USBIP_URB_* when it sends USBIP_CMD_SUBMIT packet.
359  *
360  * Server rx path (USBIP_CMD_SUBMIT):
361  * - Maps USBIP_URB_* to URB_* when it receives USBIP_CMD_SUBMIT packet.
362  *
363  * Flags aren't included in USBIP_CMD_UNLINK and USBIP_RET_SUBMIT packets
364  * and no special handling is needed for them in the following cases:
365  * - Server rx path (USBIP_CMD_UNLINK)
366  * - Client rx path & Server tx path (USBIP_RET_SUBMIT)
367  *
368  * Code paths:
369  * usbip_pack_pdu() is the common routine that handles packing pdu from
370  * urb and unpack pdu to an urb.
371  *
372  * usbip_pack_cmd_submit() and usbip_pack_ret_submit() handle
373  * USBIP_CMD_SUBMIT and USBIP_RET_SUBMIT respectively.
374  *
375  * usbip_map_urb_to_usbip() and usbip_map_usbip_to_urb() are used
376  * by usbip_pack_cmd_submit() and usbip_pack_ret_submit() to map
377  * flags.
378  */
379 
380 struct urb_to_usbip_flags {
381 	u32 urb_flag;
382 	u32 usbip_flag;
383 };
384 
385 #define NUM_USBIP_FLAGS	17
386 
387 static const struct urb_to_usbip_flags flag_map[NUM_USBIP_FLAGS] = {
388 	{URB_SHORT_NOT_OK, USBIP_URB_SHORT_NOT_OK},
389 	{URB_ISO_ASAP, USBIP_URB_ISO_ASAP},
390 	{URB_NO_TRANSFER_DMA_MAP, USBIP_URB_NO_TRANSFER_DMA_MAP},
391 	{URB_ZERO_PACKET, USBIP_URB_ZERO_PACKET},
392 	{URB_NO_INTERRUPT, USBIP_URB_NO_INTERRUPT},
393 	{URB_FREE_BUFFER, USBIP_URB_FREE_BUFFER},
394 	{URB_DIR_IN, USBIP_URB_DIR_IN},
395 	{URB_DIR_OUT, USBIP_URB_DIR_OUT},
396 	{URB_DIR_MASK, USBIP_URB_DIR_MASK},
397 	{URB_DMA_MAP_SINGLE, USBIP_URB_DMA_MAP_SINGLE},
398 	{URB_DMA_MAP_PAGE, USBIP_URB_DMA_MAP_PAGE},
399 	{URB_DMA_MAP_SG, USBIP_URB_DMA_MAP_SG},
400 	{URB_MAP_LOCAL, USBIP_URB_MAP_LOCAL},
401 	{URB_SETUP_MAP_SINGLE, USBIP_URB_SETUP_MAP_SINGLE},
402 	{URB_SETUP_MAP_LOCAL, USBIP_URB_SETUP_MAP_LOCAL},
403 	{URB_DMA_SG_COMBINED, USBIP_URB_DMA_SG_COMBINED},
404 	{URB_ALIGNED_TEMP_BUFFER, USBIP_URB_ALIGNED_TEMP_BUFFER},
405 };
406 
407 static unsigned int urb_to_usbip(unsigned int flags)
408 {
409 	unsigned int map_flags = 0;
410 	int loop;
411 
412 	for (loop = 0; loop < NUM_USBIP_FLAGS; loop++) {
413 		if (flags & flag_map[loop].urb_flag)
414 			map_flags |= flag_map[loop].usbip_flag;
415 	}
416 
417 	return map_flags;
418 }
419 
420 static unsigned int usbip_to_urb(unsigned int flags)
421 {
422 	unsigned int map_flags = 0;
423 	int loop;
424 
425 	for (loop = 0; loop < NUM_USBIP_FLAGS; loop++) {
426 		if (flags & flag_map[loop].usbip_flag)
427 			map_flags |= flag_map[loop].urb_flag;
428 	}
429 
430 	return map_flags;
431 }
432 
433 static void usbip_pack_cmd_submit(struct usbip_header *pdu, struct urb *urb,
434 				  int pack)
435 {
436 	struct usbip_header_cmd_submit *spdu = &pdu->u.cmd_submit;
437 
438 	/*
439 	 * Some members are not still implemented in usbip. I hope this issue
440 	 * will be discussed when usbip is ported to other operating systems.
441 	 */
442 	if (pack) {
443 		/* map after tweaking the urb flags */
444 		spdu->transfer_flags = urb_to_usbip(tweak_transfer_flags(urb->transfer_flags));
445 		spdu->transfer_buffer_length	= urb->transfer_buffer_length;
446 		spdu->start_frame		= urb->start_frame;
447 		spdu->number_of_packets		= urb->number_of_packets;
448 		spdu->interval			= urb->interval;
449 	} else  {
450 		urb->transfer_flags         = usbip_to_urb(spdu->transfer_flags);
451 		urb->transfer_buffer_length = spdu->transfer_buffer_length;
452 		urb->start_frame            = spdu->start_frame;
453 		urb->number_of_packets      = spdu->number_of_packets;
454 		urb->interval               = spdu->interval;
455 	}
456 }
457 
458 static void usbip_pack_ret_submit(struct usbip_header *pdu, struct urb *urb,
459 				  int pack)
460 {
461 	struct usbip_header_ret_submit *rpdu = &pdu->u.ret_submit;
462 
463 	if (pack) {
464 		rpdu->status		= urb->status;
465 		rpdu->actual_length	= urb->actual_length;
466 		rpdu->start_frame	= urb->start_frame;
467 		rpdu->number_of_packets = urb->number_of_packets;
468 		rpdu->error_count	= urb->error_count;
469 	} else {
470 		urb->status		= rpdu->status;
471 		urb->actual_length	= rpdu->actual_length;
472 		urb->start_frame	= rpdu->start_frame;
473 		urb->number_of_packets = rpdu->number_of_packets;
474 		urb->error_count	= rpdu->error_count;
475 	}
476 }
477 
478 void usbip_pack_pdu(struct usbip_header *pdu, struct urb *urb, int cmd,
479 		    int pack)
480 {
481 	switch (cmd) {
482 	case USBIP_CMD_SUBMIT:
483 		usbip_pack_cmd_submit(pdu, urb, pack);
484 		break;
485 	case USBIP_RET_SUBMIT:
486 		usbip_pack_ret_submit(pdu, urb, pack);
487 		break;
488 	default:
489 		/* NOT REACHED */
490 		pr_err("unknown command\n");
491 		break;
492 	}
493 }
494 EXPORT_SYMBOL_GPL(usbip_pack_pdu);
495 
496 static void correct_endian_basic(struct usbip_header_basic *base, int send)
497 {
498 	if (send) {
499 		base->command	= cpu_to_be32(base->command);
500 		base->seqnum	= cpu_to_be32(base->seqnum);
501 		base->devid	= cpu_to_be32(base->devid);
502 		base->direction	= cpu_to_be32(base->direction);
503 		base->ep	= cpu_to_be32(base->ep);
504 	} else {
505 		base->command	= be32_to_cpu(base->command);
506 		base->seqnum	= be32_to_cpu(base->seqnum);
507 		base->devid	= be32_to_cpu(base->devid);
508 		base->direction	= be32_to_cpu(base->direction);
509 		base->ep	= be32_to_cpu(base->ep);
510 	}
511 }
512 
513 static void correct_endian_cmd_submit(struct usbip_header_cmd_submit *pdu,
514 				      int send)
515 {
516 	if (send) {
517 		pdu->transfer_flags = cpu_to_be32(pdu->transfer_flags);
518 
519 		cpu_to_be32s(&pdu->transfer_buffer_length);
520 		cpu_to_be32s(&pdu->start_frame);
521 		cpu_to_be32s(&pdu->number_of_packets);
522 		cpu_to_be32s(&pdu->interval);
523 	} else {
524 		pdu->transfer_flags = be32_to_cpu(pdu->transfer_flags);
525 
526 		be32_to_cpus(&pdu->transfer_buffer_length);
527 		be32_to_cpus(&pdu->start_frame);
528 		be32_to_cpus(&pdu->number_of_packets);
529 		be32_to_cpus(&pdu->interval);
530 	}
531 }
532 
533 static void correct_endian_ret_submit(struct usbip_header_ret_submit *pdu,
534 				      int send)
535 {
536 	if (send) {
537 		cpu_to_be32s(&pdu->status);
538 		cpu_to_be32s(&pdu->actual_length);
539 		cpu_to_be32s(&pdu->start_frame);
540 		cpu_to_be32s(&pdu->number_of_packets);
541 		cpu_to_be32s(&pdu->error_count);
542 	} else {
543 		be32_to_cpus(&pdu->status);
544 		be32_to_cpus(&pdu->actual_length);
545 		be32_to_cpus(&pdu->start_frame);
546 		be32_to_cpus(&pdu->number_of_packets);
547 		be32_to_cpus(&pdu->error_count);
548 	}
549 }
550 
551 static void correct_endian_cmd_unlink(struct usbip_header_cmd_unlink *pdu,
552 				      int send)
553 {
554 	if (send)
555 		pdu->seqnum = cpu_to_be32(pdu->seqnum);
556 	else
557 		pdu->seqnum = be32_to_cpu(pdu->seqnum);
558 }
559 
560 static void correct_endian_ret_unlink(struct usbip_header_ret_unlink *pdu,
561 				      int send)
562 {
563 	if (send)
564 		cpu_to_be32s(&pdu->status);
565 	else
566 		be32_to_cpus(&pdu->status);
567 }
568 
569 void usbip_header_correct_endian(struct usbip_header *pdu, int send)
570 {
571 	__u32 cmd = 0;
572 
573 	if (send)
574 		cmd = pdu->base.command;
575 
576 	correct_endian_basic(&pdu->base, send);
577 
578 	if (!send)
579 		cmd = pdu->base.command;
580 
581 	switch (cmd) {
582 	case USBIP_CMD_SUBMIT:
583 		correct_endian_cmd_submit(&pdu->u.cmd_submit, send);
584 		break;
585 	case USBIP_RET_SUBMIT:
586 		correct_endian_ret_submit(&pdu->u.ret_submit, send);
587 		break;
588 	case USBIP_CMD_UNLINK:
589 		correct_endian_cmd_unlink(&pdu->u.cmd_unlink, send);
590 		break;
591 	case USBIP_RET_UNLINK:
592 		correct_endian_ret_unlink(&pdu->u.ret_unlink, send);
593 		break;
594 	default:
595 		/* NOT REACHED */
596 		pr_err("unknown command\n");
597 		break;
598 	}
599 }
600 EXPORT_SYMBOL_GPL(usbip_header_correct_endian);
601 
602 static void usbip_iso_packet_correct_endian(
603 		struct usbip_iso_packet_descriptor *iso, int send)
604 {
605 	/* does not need all members. but copy all simply. */
606 	if (send) {
607 		iso->offset	= cpu_to_be32(iso->offset);
608 		iso->length	= cpu_to_be32(iso->length);
609 		iso->status	= cpu_to_be32(iso->status);
610 		iso->actual_length = cpu_to_be32(iso->actual_length);
611 	} else {
612 		iso->offset	= be32_to_cpu(iso->offset);
613 		iso->length	= be32_to_cpu(iso->length);
614 		iso->status	= be32_to_cpu(iso->status);
615 		iso->actual_length = be32_to_cpu(iso->actual_length);
616 	}
617 }
618 
619 static void usbip_pack_iso(struct usbip_iso_packet_descriptor *iso,
620 			   struct usb_iso_packet_descriptor *uiso, int pack)
621 {
622 	if (pack) {
623 		iso->offset		= uiso->offset;
624 		iso->length		= uiso->length;
625 		iso->status		= uiso->status;
626 		iso->actual_length	= uiso->actual_length;
627 	} else {
628 		uiso->offset		= iso->offset;
629 		uiso->length		= iso->length;
630 		uiso->status		= iso->status;
631 		uiso->actual_length	= iso->actual_length;
632 	}
633 }
634 
635 /* must free buffer */
636 struct usbip_iso_packet_descriptor*
637 usbip_alloc_iso_desc_pdu(struct urb *urb, ssize_t *bufflen)
638 {
639 	struct usbip_iso_packet_descriptor *iso;
640 	int np = urb->number_of_packets;
641 	ssize_t size = np * sizeof(*iso);
642 	int i;
643 
644 	iso = kzalloc(size, GFP_KERNEL);
645 	if (!iso)
646 		return NULL;
647 
648 	for (i = 0; i < np; i++) {
649 		usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 1);
650 		usbip_iso_packet_correct_endian(&iso[i], 1);
651 	}
652 
653 	*bufflen = size;
654 
655 	return iso;
656 }
657 EXPORT_SYMBOL_GPL(usbip_alloc_iso_desc_pdu);
658 
659 /* some members of urb must be substituted before. */
660 int usbip_recv_iso(struct usbip_device *ud, struct urb *urb)
661 {
662 	void *buff;
663 	struct usbip_iso_packet_descriptor *iso;
664 	int np = urb->number_of_packets;
665 	int size = np * sizeof(*iso);
666 	int i;
667 	int ret;
668 	int total_length = 0;
669 
670 	if (!usb_pipeisoc(urb->pipe))
671 		return 0;
672 
673 	/* my Bluetooth dongle gets ISO URBs which are np = 0 */
674 	if (np == 0)
675 		return 0;
676 
677 	buff = kzalloc(size, GFP_KERNEL);
678 	if (!buff)
679 		return -ENOMEM;
680 
681 	ret = usbip_recv(ud->tcp_socket, buff, size);
682 	if (ret != size) {
683 		dev_err(&urb->dev->dev, "recv iso_frame_descriptor, %d\n",
684 			ret);
685 		kfree(buff);
686 
687 		if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
688 			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
689 		else
690 			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
691 
692 		return -EPIPE;
693 	}
694 
695 	iso = (struct usbip_iso_packet_descriptor *) buff;
696 	for (i = 0; i < np; i++) {
697 		usbip_iso_packet_correct_endian(&iso[i], 0);
698 		usbip_pack_iso(&iso[i], &urb->iso_frame_desc[i], 0);
699 		total_length += urb->iso_frame_desc[i].actual_length;
700 	}
701 
702 	kfree(buff);
703 
704 	if (total_length != urb->actual_length) {
705 		dev_err(&urb->dev->dev,
706 			"total length of iso packets %d not equal to actual length of buffer %d\n",
707 			total_length, urb->actual_length);
708 
709 		if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
710 			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
711 		else
712 			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
713 
714 		return -EPIPE;
715 	}
716 
717 	return ret;
718 }
719 EXPORT_SYMBOL_GPL(usbip_recv_iso);
720 
721 /*
722  * This functions restores the padding which was removed for optimizing
723  * the bandwidth during transfer over tcp/ip
724  *
725  * buffer and iso packets need to be stored and be in propeper endian in urb
726  * before calling this function
727  */
728 void usbip_pad_iso(struct usbip_device *ud, struct urb *urb)
729 {
730 	int np = urb->number_of_packets;
731 	int i;
732 	int actualoffset = urb->actual_length;
733 
734 	if (!usb_pipeisoc(urb->pipe))
735 		return;
736 
737 	/* if no packets or length of data is 0, then nothing to unpack */
738 	if (np == 0 || urb->actual_length == 0)
739 		return;
740 
741 	/*
742 	 * if actual_length is transfer_buffer_length then no padding is
743 	 * present.
744 	 */
745 	if (urb->actual_length == urb->transfer_buffer_length)
746 		return;
747 
748 	/*
749 	 * loop over all packets from last to first (to prevent overwriting
750 	 * memory when padding) and move them into the proper place
751 	 */
752 	for (i = np-1; i > 0; i--) {
753 		actualoffset -= urb->iso_frame_desc[i].actual_length;
754 		memmove(urb->transfer_buffer + urb->iso_frame_desc[i].offset,
755 			urb->transfer_buffer + actualoffset,
756 			urb->iso_frame_desc[i].actual_length);
757 	}
758 }
759 EXPORT_SYMBOL_GPL(usbip_pad_iso);
760 
761 /* some members of urb must be substituted before. */
762 int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
763 {
764 	struct scatterlist *sg;
765 	int ret = 0;
766 	int recv;
767 	int size;
768 	int copy;
769 	int i;
770 
771 	if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
772 		/* the direction of urb must be OUT. */
773 		if (usb_pipein(urb->pipe))
774 			return 0;
775 
776 		size = urb->transfer_buffer_length;
777 	} else {
778 		/* the direction of urb must be IN. */
779 		if (usb_pipeout(urb->pipe))
780 			return 0;
781 
782 		size = urb->actual_length;
783 	}
784 
785 	/* no need to recv xbuff */
786 	if (!(size > 0))
787 		return 0;
788 
789 	if (size > urb->transfer_buffer_length)
790 		/* should not happen, probably malicious packet */
791 		goto error;
792 
793 	if (urb->num_sgs) {
794 		copy = size;
795 		for_each_sg(urb->sg, sg, urb->num_sgs, i) {
796 			int recv_size;
797 
798 			if (copy < sg->length)
799 				recv_size = copy;
800 			else
801 				recv_size = sg->length;
802 
803 			recv = usbip_recv(ud->tcp_socket, sg_virt(sg),
804 						recv_size);
805 
806 			if (recv != recv_size)
807 				goto error;
808 
809 			copy -= recv;
810 			ret += recv;
811 
812 			if (!copy)
813 				break;
814 		}
815 
816 		if (ret != size)
817 			goto error;
818 	} else {
819 		ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
820 		if (ret != size)
821 			goto error;
822 	}
823 
824 	return ret;
825 
826 error:
827 	dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
828 	if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
829 		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
830 	else
831 		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
832 
833 	return -EPIPE;
834 }
835 EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
836 
837 static int __init usbip_core_init(void)
838 {
839 	return usbip_init_eh();
840 }
841 
842 static void __exit usbip_core_exit(void)
843 {
844 	usbip_finish_eh();
845 	return;
846 }
847 
848 module_init(usbip_core_init);
849 module_exit(usbip_core_exit);
850 
851 MODULE_AUTHOR(DRIVER_AUTHOR);
852 MODULE_DESCRIPTION(DRIVER_DESC);
853 MODULE_LICENSE("GPL");
854