1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * devices.c
4 * (C) Copyright 1999 Randy Dunlap.
5 * (C) Copyright 1999,2000 Thomas Sailer <sailer@ife.ee.ethz.ch>.
6 *     (proc file per device)
7 * (C) Copyright 1999 Deti Fliegl (new USB architecture)
8 *
9 *************************************************************
10 *
11 * <mountpoint>/devices contains USB topology, device, config, class,
12 * interface, & endpoint data.
13 *
14 * I considered using /dev/bus/usb/device# for each device
15 * as it is attached or detached, but I didn't like this for some
16 * reason -- maybe it's just too deep of a directory structure.
17 * I also don't like looking in multiple places to gather and view
18 * the data.  Having only one file for ./devices also prevents race
19 * conditions that could arise if a program was reading device info
20 * for devices that are being removed (unplugged).  (That is, the
21 * program may find a directory for devnum_12 then try to open it,
22 * but it was just unplugged, so the directory is now deleted.
23 * But programs would just have to be prepared for situations like
24 * this in any plug-and-play environment.)
25 *
26 * 1999-12-16: Thomas Sailer <sailer@ife.ee.ethz.ch>
27 *   Converted the whole proc stuff to real
28 *   read methods. Now not the whole device list needs to fit
29 *   into one page, only the device list for one bus.
30 *   Added a poll method to /sys/kernel/debug/usb/devices, to wake
31 *   up an eventual usbd
32 * 2000-01-04: Thomas Sailer <sailer@ife.ee.ethz.ch>
33 *   Turned into its own filesystem
34 * 2000-07-05: Ashley Montanaro <ashley@compsoc.man.ac.uk>
35 *   Converted file reading routine to dump to buffer once
36 *   per device, not per bus
37 */
38
39#include <linux/fs.h>
40#include <linux/mm.h>
41#include <linux/gfp.h>
42#include <linux/usb.h>
43#include <linux/usbdevice_fs.h>
44#include <linux/usb/hcd.h>
45#include <linux/mutex.h>
46#include <linux/uaccess.h>
47
48#include "usb.h"
49
50/* Define ALLOW_SERIAL_NUMBER if you want to see the serial number of devices */
51#define ALLOW_SERIAL_NUMBER
52
53static const char format_topo[] =
54/* T:  Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=dddd MxCh=dd */
55"\nT:  Bus=%2.2d Lev=%2.2d Prnt=%2.2d Port=%2.2d Cnt=%2.2d Dev#=%3d Spd=%-4s MxCh=%2d\n";
56
57static const char format_string_manufacturer[] =
58/* S:  Manufacturer=xxxx */
59  "S:  Manufacturer=%.100s\n";
60
61static const char format_string_product[] =
62/* S:  Product=xxxx */
63  "S:  Product=%.100s\n";
64
65#ifdef ALLOW_SERIAL_NUMBER
66static const char format_string_serialnumber[] =
67/* S:  SerialNumber=xxxx */
68  "S:  SerialNumber=%.100s\n";
69#endif
70
71static const char format_bandwidth[] =
72/* B:  Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd */
73  "B:  Alloc=%3d/%3d us (%2d%%), #Int=%3d, #Iso=%3d\n";
74
75static const char format_device1[] =
76/* D:  Ver=xx.xx Cls=xx(sssss) Sub=xx Prot=xx MxPS=dd #Cfgs=dd */
77  "D:  Ver=%2x.%02x Cls=%02x(%-5s) Sub=%02x Prot=%02x MxPS=%2d #Cfgs=%3d\n";
78
79static const char format_device2[] =
80/* P:  Vendor=xxxx ProdID=xxxx Rev=xx.xx */
81  "P:  Vendor=%04x ProdID=%04x Rev=%2x.%02x\n";
82
83static const char format_config[] =
84/* C:  #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA */
85  "C:%c #Ifs=%2d Cfg#=%2d Atr=%02x MxPwr=%3dmA\n";
86
87static const char format_iad[] =
88/* A:  FirstIf#=dd IfCount=dd Cls=xx(sssss) Sub=xx Prot=xx */
89  "A:  FirstIf#=%2d IfCount=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x\n";
90
91static const char format_iface[] =
92/* I:  If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/
93  "I:%c If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n";
94
95static const char format_endpt[] =
96/* E:  Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */
97  "E:  Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n";
98
99struct class_info {
100	int class;
101	char *class_name;
102};
103
104static const struct class_info clas_info[] = {
105	/* max. 5 chars. per name string */
106	{USB_CLASS_PER_INTERFACE,	">ifc"},
107	{USB_CLASS_AUDIO,		"audio"},
108	{USB_CLASS_COMM,		"comm."},
109	{USB_CLASS_HID,			"HID"},
110	{USB_CLASS_PHYSICAL,		"PID"},
111	{USB_CLASS_STILL_IMAGE,		"still"},
112	{USB_CLASS_PRINTER,		"print"},
113	{USB_CLASS_MASS_STORAGE,	"stor."},
114	{USB_CLASS_HUB,			"hub"},
115	{USB_CLASS_CDC_DATA,		"data"},
116	{USB_CLASS_CSCID,		"scard"},
117	{USB_CLASS_CONTENT_SEC,		"c-sec"},
118	{USB_CLASS_VIDEO,		"video"},
119	{USB_CLASS_PERSONAL_HEALTHCARE,	"perhc"},
120	{USB_CLASS_AUDIO_VIDEO,		"av"},
121	{USB_CLASS_BILLBOARD,		"blbrd"},
122	{USB_CLASS_USB_TYPE_C_BRIDGE,	"bridg"},
123	{USB_CLASS_WIRELESS_CONTROLLER,	"wlcon"},
124	{USB_CLASS_MISC,		"misc"},
125	{USB_CLASS_APP_SPEC,		"app."},
126	{USB_CLASS_VENDOR_SPEC,		"vend."},
127	{-1,				"unk."}		/* leave as last */
128};
129
130/*****************************************************************/
131
132static const char *class_decode(const int class)
133{
134	int ix;
135
136	for (ix = 0; clas_info[ix].class != -1; ix++)
137		if (clas_info[ix].class == class)
138			break;
139	return clas_info[ix].class_name;
140}
141
142static char *usb_dump_endpoint_descriptor(int speed, char *start, char *end,
143				const struct usb_endpoint_descriptor *desc)
144{
145	char dir, unit, *type;
146	unsigned interval, bandwidth = 1;
147
148	if (start > end)
149		return start;
150
151	dir = usb_endpoint_dir_in(desc) ? 'I' : 'O';
152
153	if (speed == USB_SPEED_HIGH)
154		bandwidth = usb_endpoint_maxp_mult(desc);
155
156	/* this isn't checking for illegal values */
157	switch (usb_endpoint_type(desc)) {
158	case USB_ENDPOINT_XFER_CONTROL:
159		type = "Ctrl";
160		dir = 'B';			/* ctrl is bidirectional */
161		break;
162	case USB_ENDPOINT_XFER_ISOC:
163		type = "Isoc";
164		break;
165	case USB_ENDPOINT_XFER_BULK:
166		type = "Bulk";
167		break;
168	case USB_ENDPOINT_XFER_INT:
169		type = "Int.";
170		break;
171	default:	/* "can't happen" */
172		return start;
173	}
174
175	interval = usb_decode_interval(desc, speed);
176	if (interval % 1000) {
177		unit = 'u';
178	} else {
179		unit = 'm';
180		interval /= 1000;
181	}
182
183	start += sprintf(start, format_endpt, desc->bEndpointAddress, dir,
184			 desc->bmAttributes, type,
185			 usb_endpoint_maxp(desc) *
186			 bandwidth,
187			 interval, unit);
188	return start;
189}
190
191static char *usb_dump_interface_descriptor(char *start, char *end,
192					const struct usb_interface_cache *intfc,
193					const struct usb_interface *iface,
194					int setno)
195{
196	const struct usb_interface_descriptor *desc;
197	const char *driver_name = "";
198	int active = 0;
199
200	if (start > end)
201		return start;
202	desc = &intfc->altsetting[setno].desc;
203	if (iface) {
204		driver_name = (iface->dev.driver
205				? iface->dev.driver->name
206				: "(none)");
207		active = (desc == &iface->cur_altsetting->desc);
208	}
209	start += sprintf(start, format_iface,
210			 active ? '*' : ' ',	/* mark active altsetting */
211			 desc->bInterfaceNumber,
212			 desc->bAlternateSetting,
213			 desc->bNumEndpoints,
214			 desc->bInterfaceClass,
215			 class_decode(desc->bInterfaceClass),
216			 desc->bInterfaceSubClass,
217			 desc->bInterfaceProtocol,
218			 driver_name);
219	return start;
220}
221
222static char *usb_dump_interface(int speed, char *start, char *end,
223				const struct usb_interface_cache *intfc,
224				const struct usb_interface *iface, int setno)
225{
226	const struct usb_host_interface *desc = &intfc->altsetting[setno];
227	int i;
228
229	start = usb_dump_interface_descriptor(start, end, intfc, iface, setno);
230	for (i = 0; i < desc->desc.bNumEndpoints; i++) {
231		start = usb_dump_endpoint_descriptor(speed,
232				start, end, &desc->endpoint[i].desc);
233	}
234	return start;
235}
236
237static char *usb_dump_iad_descriptor(char *start, char *end,
238			const struct usb_interface_assoc_descriptor *iad)
239{
240	if (start > end)
241		return start;
242	start += sprintf(start, format_iad,
243			 iad->bFirstInterface,
244			 iad->bInterfaceCount,
245			 iad->bFunctionClass,
246			 class_decode(iad->bFunctionClass),
247			 iad->bFunctionSubClass,
248			 iad->bFunctionProtocol);
249	return start;
250}
251
252/* TBD:
253 * 0. TBDs
254 * 1. marking active interface altsettings (code lists all, but should mark
255 *    which ones are active, if any)
256 */
257static char *usb_dump_config_descriptor(char *start, char *end,
258				const struct usb_config_descriptor *desc,
259				int active, int speed)
260{
261	int mul;
262
263	if (start > end)
264		return start;
265	if (speed >= USB_SPEED_SUPER)
266		mul = 8;
267	else
268		mul = 2;
269	start += sprintf(start, format_config,
270			 /* mark active/actual/current cfg. */
271			 active ? '*' : ' ',
272			 desc->bNumInterfaces,
273			 desc->bConfigurationValue,
274			 desc->bmAttributes,
275			 desc->bMaxPower * mul);
276	return start;
277}
278
279static char *usb_dump_config(int speed, char *start, char *end,
280			     const struct usb_host_config *config, int active)
281{
282	int i, j;
283	struct usb_interface_cache *intfc;
284	struct usb_interface *interface;
285
286	if (start > end)
287		return start;
288	if (!config)
289		/* getting these some in 2.3.7; none in 2.3.6 */
290		return start + sprintf(start, "(null Cfg. desc.)\n");
291	start = usb_dump_config_descriptor(start, end, &config->desc, active,
292			speed);
293	for (i = 0; i < USB_MAXIADS; i++) {
294		if (config->intf_assoc[i] == NULL)
295			break;
296		start = usb_dump_iad_descriptor(start, end,
297					config->intf_assoc[i]);
298	}
299	for (i = 0; i < config->desc.bNumInterfaces; i++) {
300		intfc = config->intf_cache[i];
301		interface = config->interface[i];
302		for (j = 0; j < intfc->num_altsetting; j++) {
303			start = usb_dump_interface(speed,
304				start, end, intfc, interface, j);
305		}
306	}
307	return start;
308}
309
310/*
311 * Dump the different USB descriptors.
312 */
313static char *usb_dump_device_descriptor(char *start, char *end,
314				const struct usb_device_descriptor *desc)
315{
316	u16 bcdUSB = le16_to_cpu(desc->bcdUSB);
317	u16 bcdDevice = le16_to_cpu(desc->bcdDevice);
318
319	if (start > end)
320		return start;
321	start += sprintf(start, format_device1,
322			  bcdUSB >> 8, bcdUSB & 0xff,
323			  desc->bDeviceClass,
324			  class_decode(desc->bDeviceClass),
325			  desc->bDeviceSubClass,
326			  desc->bDeviceProtocol,
327			  desc->bMaxPacketSize0,
328			  desc->bNumConfigurations);
329	if (start > end)
330		return start;
331	start += sprintf(start, format_device2,
332			 le16_to_cpu(desc->idVendor),
333			 le16_to_cpu(desc->idProduct),
334			 bcdDevice >> 8, bcdDevice & 0xff);
335	return start;
336}
337
338/*
339 * Dump the different strings that this device holds.
340 */
341static char *usb_dump_device_strings(char *start, char *end,
342				     struct usb_device *dev)
343{
344	if (start > end)
345		return start;
346	if (dev->manufacturer)
347		start += sprintf(start, format_string_manufacturer,
348				 dev->manufacturer);
349	if (start > end)
350		goto out;
351	if (dev->product)
352		start += sprintf(start, format_string_product, dev->product);
353	if (start > end)
354		goto out;
355#ifdef ALLOW_SERIAL_NUMBER
356	if (dev->serial)
357		start += sprintf(start, format_string_serialnumber,
358				 dev->serial);
359#endif
360 out:
361	return start;
362}
363
364static char *usb_dump_desc(char *start, char *end, struct usb_device *dev)
365{
366	int i;
367
368	start = usb_dump_device_descriptor(start, end, &dev->descriptor);
369
370	start = usb_dump_device_strings(start, end, dev);
371
372	for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
373		start = usb_dump_config(dev->speed,
374				start, end, dev->config + i,
375				/* active ? */
376				(dev->config + i) == dev->actconfig);
377	}
378	return start;
379}
380
381/*****************************************************************/
382
383/* This is a recursive function. Parameters:
384 * buffer - the user-space buffer to write data into
385 * nbytes - the maximum number of bytes to write
386 * skip_bytes - the number of bytes to skip before writing anything
387 * file_offset - the offset into the devices file on completion
388 * The caller must own the device lock.
389 */
390static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes,
391			       loff_t *skip_bytes, loff_t *file_offset,
392			       struct usb_device *usbdev, struct usb_bus *bus,
393			       int level, int index, int count)
394{
395	int chix;
396	int ret, cnt = 0;
397	int parent_devnum = 0;
398	char *pages_start, *data_end, *speed;
399	unsigned int length;
400	ssize_t total_written = 0;
401	struct usb_device *childdev = NULL;
402
403	/* don't bother with anything else if we're not writing any data */
404	if (*nbytes <= 0)
405		return 0;
406
407	if (level > MAX_TOPO_LEVEL)
408		return 0;
409	/* allocate 2^1 pages = 8K (on i386);
410	 * should be more than enough for one device */
411	pages_start = (char *)__get_free_pages(GFP_NOIO, 1);
412	if (!pages_start)
413		return -ENOMEM;
414
415	if (usbdev->parent && usbdev->parent->devnum != -1)
416		parent_devnum = usbdev->parent->devnum;
417	/*
418	 * So the root hub's parent is 0 and any device that is
419	 * plugged into the root hub has a parent of 0.
420	 */
421	switch (usbdev->speed) {
422	case USB_SPEED_LOW:
423		speed = "1.5"; break;
424	case USB_SPEED_UNKNOWN:		/* usb 1.1 root hub code */
425	case USB_SPEED_FULL:
426		speed = "12"; break;
427	case USB_SPEED_HIGH:
428		speed = "480"; break;
429	case USB_SPEED_SUPER:
430		speed = "5000"; break;
431	case USB_SPEED_SUPER_PLUS:
432		speed = "10000"; break;
433	default:
434		speed = "??";
435	}
436	data_end = pages_start + sprintf(pages_start, format_topo,
437			bus->busnum, level, parent_devnum,
438			index, count, usbdev->devnum,
439			speed, usbdev->maxchild);
440	/*
441	 * level = topology-tier level;
442	 * parent_devnum = parent device number;
443	 * index = parent's connector number;
444	 * count = device count at this level
445	 */
446	/* If this is the root hub, display the bandwidth information */
447	if (level == 0) {
448		int	max;
449
450		/* super/high speed reserves 80%, full/low reserves 90% */
451		if (usbdev->speed == USB_SPEED_HIGH ||
452		    usbdev->speed >= USB_SPEED_SUPER)
453			max = 800;
454		else
455			max = FRAME_TIME_MAX_USECS_ALLOC;
456
457		/* report "average" periodic allocation over a microsecond.
458		 * the schedules are actually bursty, HCDs need to deal with
459		 * that and just compute/report this average.
460		 */
461		data_end += sprintf(data_end, format_bandwidth,
462				bus->bandwidth_allocated, max,
463				(100 * bus->bandwidth_allocated + max / 2)
464					/ max,
465				bus->bandwidth_int_reqs,
466				bus->bandwidth_isoc_reqs);
467
468	}
469	data_end = usb_dump_desc(data_end, pages_start + (2 * PAGE_SIZE) - 256,
470				 usbdev);
471
472	if (data_end > (pages_start + (2 * PAGE_SIZE) - 256))
473		data_end += sprintf(data_end, "(truncated)\n");
474
475	length = data_end - pages_start;
476	/* if we can start copying some data to the user */
477	if (length > *skip_bytes) {
478		length -= *skip_bytes;
479		if (length > *nbytes)
480			length = *nbytes;
481		if (copy_to_user(*buffer, pages_start + *skip_bytes, length)) {
482			free_pages((unsigned long)pages_start, 1);
483			return -EFAULT;
484		}
485		*nbytes -= length;
486		*file_offset += length;
487		total_written += length;
488		*buffer += length;
489		*skip_bytes = 0;
490	} else
491		*skip_bytes -= length;
492
493	free_pages((unsigned long)pages_start, 1);
494
495	/* Now look at all of this device's children. */
496	usb_hub_for_each_child(usbdev, chix, childdev) {
497		usb_lock_device(childdev);
498		ret = usb_device_dump(buffer, nbytes, skip_bytes,
499				      file_offset, childdev, bus,
500				      level + 1, chix - 1, ++cnt);
501		usb_unlock_device(childdev);
502		if (ret == -EFAULT)
503			return total_written;
504		total_written += ret;
505	}
506	return total_written;
507}
508
509static ssize_t usb_device_read(struct file *file, char __user *buf,
510			       size_t nbytes, loff_t *ppos)
511{
512	struct usb_bus *bus;
513	ssize_t ret, total_written = 0;
514	loff_t skip_bytes = *ppos;
515	int id;
516
517	if (*ppos < 0)
518		return -EINVAL;
519	if (nbytes <= 0)
520		return 0;
521
522	mutex_lock(&usb_bus_idr_lock);
523	/* print devices for all busses */
524	idr_for_each_entry(&usb_bus_idr, bus, id) {
525		/* recurse through all children of the root hub */
526		if (!bus_to_hcd(bus)->rh_registered)
527			continue;
528		usb_lock_device(bus->root_hub);
529		ret = usb_device_dump(&buf, &nbytes, &skip_bytes, ppos,
530				      bus->root_hub, bus, 0, 0, 0);
531		usb_unlock_device(bus->root_hub);
532		if (ret < 0) {
533			mutex_unlock(&usb_bus_idr_lock);
534			return ret;
535		}
536		total_written += ret;
537	}
538	mutex_unlock(&usb_bus_idr_lock);
539	return total_written;
540}
541
542const struct file_operations usbfs_devices_fops = {
543	.llseek =	no_seek_end_llseek,
544	.read =		usb_device_read,
545};
546