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