drivers/usb/core/devices.c

   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
  53 static 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
  57 static const char format_string_manufacturer[] =
  58 /* S:  Manufacturer=xxxx */
  59   "S:  Manufacturer=%.100s\n";
  60
  61 static const char format_string_product[] =
  62 /* S:  Product=xxxx */
  63   "S:  Product=%.100s\n";
  64
  65 #ifdef ALLOW_SERIAL_NUMBER
  66 static const char format_string_serialnumber[] =
  67 /* S:  SerialNumber=xxxx */
  68   "S:  SerialNumber=%.100s\n";
  69 #endif
  70
  71 static 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
  75 static 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
  79 static const char format_device2[] =
  80 /* P:  Vendor=xxxx ProdID=xxxx Rev=xx.xx */
  81   "P:  Vendor=%04x ProdID=%04x Rev=%2x.%02x\n";
  82
  83 static 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
  87 static 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
  91 static 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
  95 static 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
  99 struct class_info {
 100         int class;
 101         char *class_name;
 102 };
 103
 104 static 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
 132 static 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
 142 static 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
 191 static 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
 222 static 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
 237 static 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  */
 257 static 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
 279 static 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  */
 313 static 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  */
 341 static 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
 364 static 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  */
 390 static 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
 509 static 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
 542 const struct file_operations usbfs_devices_fops = {
 543         .llseek =       no_seek_end_llseek,
 544         .read =         usb_device_read,
 545 };