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                 if (speed == USB_SPEED_HIGH)    /* uframes per NAK */
 161                         interval = desc->bInterval;
 162                 else
 163                         interval = 0;
 164                 dir = 'B';                      /* ctrl is bidirectional */
 165                 break;
 166         case USB_ENDPOINT_XFER_ISOC:
 167                 type = "Isoc";
 168                 interval = 1 << (desc->bInterval - 1);
 169                 break;
 170         case USB_ENDPOINT_XFER_BULK:
 171                 type = "Bulk";
 172                 if (speed == USB_SPEED_HIGH && dir == 'O') /* uframes per NAK */
 173                         interval = desc->bInterval;
 174                 else
 175                         interval = 0;
 176                 break;
 177         case USB_ENDPOINT_XFER_INT:
 178                 type = "Int.";
 179                 if (speed == USB_SPEED_HIGH || speed >= USB_SPEED_SUPER)
 180                         interval = 1 << (desc->bInterval - 1);
 181                 else
 182                         interval = desc->bInterval;
 183                 break;
 184         default:        /* "can't happen" */
 185                 return start;
 186         }
 187         interval *= (speed == USB_SPEED_HIGH ||
 188                      speed >= USB_SPEED_SUPER) ? 125 : 1000;
 189         if (interval % 1000)
 190                 unit = 'u';
 191         else {
 192                 unit = 'm';
 193                 interval /= 1000;
 194         }
 195
 196         start += sprintf(start, format_endpt, desc->bEndpointAddress, dir,
 197                          desc->bmAttributes, type,
 198                          usb_endpoint_maxp(desc) *
 199                          bandwidth,
 200                          interval, unit);
 201         return start;
 202 }
 203
 204 static char *usb_dump_interface_descriptor(char *start, char *end,
 205                                         const struct usb_interface_cache *intfc,
 206                                         const struct usb_interface *iface,
 207                                         int setno)
 208 {
 209         const struct usb_interface_descriptor *desc;
 210         const char *driver_name = "";
 211         int active = 0;
 212
 213         if (start > end)
 214                 return start;
 215         desc = &intfc->altsetting[setno].desc;
 216         if (iface) {
 217                 driver_name = (iface->dev.driver
 218                                 ? iface->dev.driver->name
 219                                 : "(none)");
 220                 active = (desc == &iface->cur_altsetting->desc);
 221         }
 222         start += sprintf(start, format_iface,
 223                          active ? '*' : ' ',    /* mark active altsetting */
 224                          desc->bInterfaceNumber,
 225                          desc->bAlternateSetting,
 226                          desc->bNumEndpoints,
 227                          desc->bInterfaceClass,
 228                          class_decode(desc->bInterfaceClass),
 229                          desc->bInterfaceSubClass,
 230                          desc->bInterfaceProtocol,
 231                          driver_name);
 232         return start;
 233 }
 234
 235 static char *usb_dump_interface(int speed, char *start, char *end,
 236                                 const struct usb_interface_cache *intfc,
 237                                 const struct usb_interface *iface, int setno)
 238 {
 239         const struct usb_host_interface *desc = &intfc->altsetting[setno];
 240         int i;
 241
 242         start = usb_dump_interface_descriptor(start, end, intfc, iface, setno);
 243         for (i = 0; i < desc->desc.bNumEndpoints; i++) {
 244                 if (start > end)
 245                         return start;
 246                 start = usb_dump_endpoint_descriptor(speed,
 247                                 start, end, &desc->endpoint[i].desc);
 248         }
 249         return start;
 250 }
 251
 252 static char *usb_dump_iad_descriptor(char *start, char *end,
 253                         const struct usb_interface_assoc_descriptor *iad)
 254 {
 255         if (start > end)
 256                 return start;
 257         start += sprintf(start, format_iad,
 258                          iad->bFirstInterface,
 259                          iad->bInterfaceCount,
 260                          iad->bFunctionClass,
 261                          class_decode(iad->bFunctionClass),
 262                          iad->bFunctionSubClass,
 263                          iad->bFunctionProtocol);
 264         return start;
 265 }
 266
 267 /* TBD:
 268  * 0. TBDs
 269  * 1. marking active interface altsettings (code lists all, but should mark
 270  *    which ones are active, if any)
 271  */
 272 static char *usb_dump_config_descriptor(char *start, char *end,
 273                                 const struct usb_config_descriptor *desc,
 274                                 int active, int speed)
 275 {
 276         int mul;
 277
 278         if (start > end)
 279                 return start;
 280         if (speed >= USB_SPEED_SUPER)
 281                 mul = 8;
 282         else
 283                 mul = 2;
 284         start += sprintf(start, format_config,
 285                          /* mark active/actual/current cfg. */
 286                          active ? '*' : ' ',
 287                          desc->bNumInterfaces,
 288                          desc->bConfigurationValue,
 289                          desc->bmAttributes,
 290                          desc->bMaxPower * mul);
 291         return start;
 292 }
 293
 294 static char *usb_dump_config(int speed, char *start, char *end,
 295                              const struct usb_host_config *config, int active)
 296 {
 297         int i, j;
 298         struct usb_interface_cache *intfc;
 299         struct usb_interface *interface;
 300
 301         if (start > end)
 302                 return start;
 303         if (!config)
 304                 /* getting these some in 2.3.7; none in 2.3.6 */
 305                 return start + sprintf(start, "(null Cfg. desc.)\n");
 306         start = usb_dump_config_descriptor(start, end, &config->desc, active,
 307                         speed);
 308         for (i = 0; i < USB_MAXIADS; i++) {
 309                 if (config->intf_assoc[i] == NULL)
 310                         break;
 311                 start = usb_dump_iad_descriptor(start, end,
 312                                         config->intf_assoc[i]);
 313         }
 314         for (i = 0; i < config->desc.bNumInterfaces; i++) {
 315                 intfc = config->intf_cache[i];
 316                 interface = config->interface[i];
 317                 for (j = 0; j < intfc->num_altsetting; j++) {
 318                         if (start > end)
 319                                 return start;
 320                         start = usb_dump_interface(speed,
 321                                 start, end, intfc, interface, j);
 322                 }
 323         }
 324         return start;
 325 }
 326
 327 /*
 328  * Dump the different USB descriptors.
 329  */
 330 static char *usb_dump_device_descriptor(char *start, char *end,
 331                                 const struct usb_device_descriptor *desc)
 332 {
 333         u16 bcdUSB = le16_to_cpu(desc->bcdUSB);
 334         u16 bcdDevice = le16_to_cpu(desc->bcdDevice);
 335
 336         if (start > end)
 337                 return start;
 338         start += sprintf(start, format_device1,
 339                           bcdUSB >> 8, bcdUSB & 0xff,
 340                           desc->bDeviceClass,
 341                           class_decode(desc->bDeviceClass),
 342                           desc->bDeviceSubClass,
 343                           desc->bDeviceProtocol,
 344                           desc->bMaxPacketSize0,
 345                           desc->bNumConfigurations);
 346         if (start > end)
 347                 return start;
 348         start += sprintf(start, format_device2,
 349                          le16_to_cpu(desc->idVendor),
 350                          le16_to_cpu(desc->idProduct),
 351                          bcdDevice >> 8, bcdDevice & 0xff);
 352         return start;
 353 }
 354
 355 /*
 356  * Dump the different strings that this device holds.
 357  */
 358 static char *usb_dump_device_strings(char *start, char *end,
 359                                      struct usb_device *dev)
 360 {
 361         if (start > end)
 362                 return start;
 363         if (dev->manufacturer)
 364                 start += sprintf(start, format_string_manufacturer,
 365                                  dev->manufacturer);
 366         if (start > end)
 367                 goto out;
 368         if (dev->product)
 369                 start += sprintf(start, format_string_product, dev->product);
 370         if (start > end)
 371                 goto out;
 372 #ifdef ALLOW_SERIAL_NUMBER
 373         if (dev->serial)
 374                 start += sprintf(start, format_string_serialnumber,
 375                                  dev->serial);
 376 #endif
 377  out:
 378         return start;
 379 }
 380
 381 static char *usb_dump_desc(char *start, char *end, struct usb_device *dev)
 382 {
 383         int i;
 384
 385         if (start > end)
 386                 return start;
 387
 388         start = usb_dump_device_descriptor(start, end, &dev->descriptor);
 389
 390         if (start > end)
 391                 return start;
 392
 393         start = usb_dump_device_strings(start, end, dev);
 394
 395         for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
 396                 if (start > end)
 397                         return start;
 398                 start = usb_dump_config(dev->speed,
 399                                 start, end, dev->config + i,
 400                                 /* active ? */
 401                                 (dev->config + i) == dev->actconfig);
 402         }
 403         return start;
 404 }
 405
 406
 407 #ifdef PROC_EXTRA /* TBD: may want to add this code later */
 408
 409 static char *usb_dump_hub_descriptor(char *start, char *end,
 410                                      const struct usb_hub_descriptor *desc)
 411 {
 412         int leng = USB_DT_HUB_NONVAR_SIZE;
 413         unsigned char *ptr = (unsigned char *)desc;
 414
 415         if (start > end)
 416                 return start;
 417         start += sprintf(start, "Interface:");
 418         while (leng && start <= end) {
 419                 start += sprintf(start, " %02x", *ptr);
 420                 ptr++; leng--;
 421         }
 422         *start++ = '\n';
 423         return start;
 424 }
 425
 426 static char *usb_dump_string(char *start, char *end,
 427                              const struct usb_device *dev, char *id, int index)
 428 {
 429         if (start > end)
 430                 return start;
 431         start += sprintf(start, "Interface:");
 432         if (index <= dev->maxstring && dev->stringindex &&
 433             dev->stringindex[index])
 434                 start += sprintf(start, "%s: %.100s ", id,
 435                                  dev->stringindex[index]);
 436         return start;
 437 }
 438
 439 #endif /* PROC_EXTRA */
 440
 441 /*****************************************************************/
 442
 443 /* This is a recursive function. Parameters:
 444  * buffer - the user-space buffer to write data into
 445  * nbytes - the maximum number of bytes to write
 446  * skip_bytes - the number of bytes to skip before writing anything
 447  * file_offset - the offset into the devices file on completion
 448  * The caller must own the device lock.
 449  */
 450 static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes,
 451                                loff_t *skip_bytes, loff_t *file_offset,
 452                                struct usb_device *usbdev, struct usb_bus *bus,
 453                                int level, int index, int count)
 454 {
 455         int chix;
 456         int ret, cnt = 0;
 457         int parent_devnum = 0;
 458         char *pages_start, *data_end, *speed;
 459         unsigned int length;
 460         ssize_t total_written = 0;
 461         struct usb_device *childdev = NULL;
 462
 463         /* don't bother with anything else if we're not writing any data */
 464         if (*nbytes <= 0)
 465                 return 0;
 466
 467         if (level > MAX_TOPO_LEVEL)
 468                 return 0;
 469         /* allocate 2^1 pages = 8K (on i386);
 470          * should be more than enough for one device */
 471         pages_start = (char *)__get_free_pages(GFP_NOIO, 1);
 472         if (!pages_start)
 473                 return -ENOMEM;
 474
 475         if (usbdev->parent && usbdev->parent->devnum != -1)
 476                 parent_devnum = usbdev->parent->devnum;
 477         /*
 478          * So the root hub's parent is 0 and any device that is
 479          * plugged into the root hub has a parent of 0.
 480          */
 481         switch (usbdev->speed) {
 482         case USB_SPEED_LOW:
 483                 speed = "1.5"; break;
 484         case USB_SPEED_UNKNOWN:         /* usb 1.1 root hub code */
 485         case USB_SPEED_FULL:
 486                 speed = "12"; break;
 487         case USB_SPEED_WIRELESS:        /* Wireless has no real fixed speed */
 488         case USB_SPEED_HIGH:
 489                 speed = "480"; break;
 490         case USB_SPEED_SUPER:
 491                 speed = "5000"; break;
 492         case USB_SPEED_SUPER_PLUS:
 493                 speed = "10000"; break;
 494         default:
 495                 speed = "??";
 496         }
 497         data_end = pages_start + sprintf(pages_start, format_topo,
 498                         bus->busnum, level, parent_devnum,
 499                         index, count, usbdev->devnum,
 500                         speed, usbdev->maxchild);
 501         /*
 502          * level = topology-tier level;
 503          * parent_devnum = parent device number;
 504          * index = parent's connector number;
 505          * count = device count at this level
 506          */
 507         /* If this is the root hub, display the bandwidth information */
 508         if (level == 0) {
 509                 int     max;
 510
 511                 /* super/high speed reserves 80%, full/low reserves 90% */
 512                 if (usbdev->speed == USB_SPEED_HIGH ||
 513                     usbdev->speed >= USB_SPEED_SUPER)
 514                         max = 800;
 515                 else
 516                         max = FRAME_TIME_MAX_USECS_ALLOC;
 517
 518                 /* report "average" periodic allocation over a microsecond.
 519                  * the schedules are actually bursty, HCDs need to deal with
 520                  * that and just compute/report this average.
 521                  */
 522                 data_end += sprintf(data_end, format_bandwidth,
 523                                 bus->bandwidth_allocated, max,
 524                                 (100 * bus->bandwidth_allocated + max / 2)
 525                                         / max,
 526                                 bus->bandwidth_int_reqs,
 527                                 bus->bandwidth_isoc_reqs);
 528
 529         }
 530         data_end = usb_dump_desc(data_end, pages_start + (2 * PAGE_SIZE) - 256,
 531                                  usbdev);
 532
 533         if (data_end > (pages_start + (2 * PAGE_SIZE) - 256))
 534                 data_end += sprintf(data_end, "(truncated)\n");
 535
 536         length = data_end - pages_start;
 537         /* if we can start copying some data to the user */
 538         if (length > *skip_bytes) {
 539                 length -= *skip_bytes;
 540                 if (length > *nbytes)
 541                         length = *nbytes;
 542                 if (copy_to_user(*buffer, pages_start + *skip_bytes, length)) {
 543                         free_pages((unsigned long)pages_start, 1);
 544                         return -EFAULT;
 545                 }
 546                 *nbytes -= length;
 547                 *file_offset += length;
 548                 total_written += length;
 549                 *buffer += length;
 550                 *skip_bytes = 0;
 551         } else
 552                 *skip_bytes -= length;
 553
 554         free_pages((unsigned long)pages_start, 1);
 555
 556         /* Now look at all of this device's children. */
 557         usb_hub_for_each_child(usbdev, chix, childdev) {
 558                 usb_lock_device(childdev);
 559                 ret = usb_device_dump(buffer, nbytes, skip_bytes,
 560                                       file_offset, childdev, bus,
 561                                       level + 1, chix - 1, ++cnt);
 562                 usb_unlock_device(childdev);
 563                 if (ret == -EFAULT)
 564                         return total_written;
 565                 total_written += ret;
 566         }
 567         return total_written;
 568 }
 569
 570 static ssize_t usb_device_read(struct file *file, char __user *buf,
 571                                size_t nbytes, loff_t *ppos)
 572 {
 573         struct usb_bus *bus;
 574         ssize_t ret, total_written = 0;
 575         loff_t skip_bytes = *ppos;
 576         int id;
 577
 578         if (*ppos < 0)
 579                 return -EINVAL;
 580         if (nbytes <= 0)
 581                 return 0;
 582
 583         mutex_lock(&usb_bus_idr_lock);
 584         /* print devices for all busses */
 585         idr_for_each_entry(&usb_bus_idr, bus, id) {
 586                 /* recurse through all children of the root hub */
 587                 if (!bus_to_hcd(bus)->rh_registered)
 588                         continue;
 589                 usb_lock_device(bus->root_hub);
 590                 ret = usb_device_dump(&buf, &nbytes, &skip_bytes, ppos,
 591                                       bus->root_hub, bus, 0, 0, 0);
 592                 usb_unlock_device(bus->root_hub);
 593                 if (ret < 0) {
 594                         mutex_unlock(&usb_bus_idr_lock);
 595                         return ret;
 596                 }
 597                 total_written += ret;
 598         }
 599         mutex_unlock(&usb_bus_idr_lock);
 600         return total_written;
 601 }
 602
 603 const struct file_operations usbfs_devices_fops = {
 604         .llseek =       no_seek_end_llseek,
 605         .read =         usb_device_read,
 606 };