drivers/usb/core/config.c

   1 #include <linux/config.h>
   2
   3 #ifdef CONFIG_USB_DEBUG
   4 #define DEBUG
   5 #endif
   6
   7 #include <linux/usb.h>
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/device.h>
  12 #include <asm/byteorder.h>
  13
  14
  15 #define USB_MAXALTSETTING               128     /* Hard limit */
  16 #define USB_MAXENDPOINTS                30      /* Hard limit */
  17
  18 #define USB_MAXCONFIG                   8       /* Arbitrary limit */
  19
  20
  21 static inline const char *plural(int n)
  22 {
  23         return (n == 1 ? "" : "s");
  24 }
  25
  26 static int find_next_descriptor(unsigned char *buffer, int size,
  27     int dt1, int dt2, int *num_skipped)
  28 {
  29         struct usb_descriptor_header *h;
  30         int n = 0;
  31         unsigned char *buffer0 = buffer;
  32
  33         /* Find the next descriptor of type dt1 or dt2 */
  34         while (size > 0) {
  35                 h = (struct usb_descriptor_header *) buffer;
  36                 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
  37                         break;
  38                 buffer += h->bLength;
  39                 size -= h->bLength;
  40                 ++n;
  41         }
  42
  43         /* Store the number of descriptors skipped and return the
  44          * number of bytes skipped */
  45         if (num_skipped)
  46                 *num_skipped = n;
  47         return buffer - buffer0;
  48 }
  49
  50 static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
  51     int asnum, struct usb_host_interface *ifp, int num_ep,
  52     unsigned char *buffer, int size)
  53 {
  54         unsigned char *buffer0 = buffer;
  55         struct usb_endpoint_descriptor *d;
  56         struct usb_host_endpoint *endpoint;
  57         int n, i;
  58
  59         d = (struct usb_endpoint_descriptor *) buffer;
  60         buffer += d->bLength;
  61         size -= d->bLength;
  62
  63         if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
  64                 n = USB_DT_ENDPOINT_AUDIO_SIZE;
  65         else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
  66                 n = USB_DT_ENDPOINT_SIZE;
  67         else {
  68                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
  69                     "invalid endpoint descriptor of length %d, skipping\n",
  70                     cfgno, inum, asnum, d->bLength);
  71                 goto skip_to_next_endpoint_or_interface_descriptor;
  72         }
  73
  74         i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
  75         if (i >= 16 || i == 0) {
  76                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
  77                     "invalid endpoint with address 0x%X, skipping\n",
  78                     cfgno, inum, asnum, d->bEndpointAddress);
  79                 goto skip_to_next_endpoint_or_interface_descriptor;
  80         }
  81
  82         /* Only store as many endpoints as we have room for */
  83         if (ifp->desc.bNumEndpoints >= num_ep)
  84                 goto skip_to_next_endpoint_or_interface_descriptor;
  85
  86         endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
  87         ++ifp->desc.bNumEndpoints;
  88
  89         memcpy(&endpoint->desc, d, n);
  90         INIT_LIST_HEAD(&endpoint->urb_list);
  91
  92         /* Skip over any Class Specific or Vendor Specific descriptors;
  93          * find the next endpoint or interface descriptor */
  94         endpoint->extra = buffer;
  95         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
  96             USB_DT_INTERFACE, &n);
  97         endpoint->extralen = i;
  98         if (n > 0)
  99                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 100                     n, plural(n), "endpoint");
 101         return buffer - buffer0 + i;
 102
 103 skip_to_next_endpoint_or_interface_descriptor:
 104         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 105             USB_DT_INTERFACE, NULL);
 106         return buffer - buffer0 + i;
 107 }
 108
 109 void usb_release_interface_cache(struct kref *ref)
 110 {
 111         struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
 112         int j;
 113
 114         for (j = 0; j < intfc->num_altsetting; j++)
 115                 kfree(intfc->altsetting[j].endpoint);
 116         kfree(intfc);
 117 }
 118
 119 static int usb_parse_interface(struct device *ddev, int cfgno,
 120     struct usb_host_config *config, unsigned char *buffer, int size,
 121     u8 inums[], u8 nalts[])
 122 {
 123         unsigned char *buffer0 = buffer;
 124         struct usb_interface_descriptor *d;
 125         int inum, asnum;
 126         struct usb_interface_cache *intfc;
 127         struct usb_host_interface *alt;
 128         int i, n;
 129         int len, retval;
 130         int num_ep, num_ep_orig;
 131
 132         d = (struct usb_interface_descriptor *) buffer;
 133         buffer += d->bLength;
 134         size -= d->bLength;
 135
 136         if (d->bLength < USB_DT_INTERFACE_SIZE)
 137                 goto skip_to_next_interface_descriptor;
 138
 139         /* Which interface entry is this? */
 140         intfc = NULL;
 141         inum = d->bInterfaceNumber;
 142         for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 143                 if (inums[i] == inum) {
 144                         intfc = config->intf_cache[i];
 145                         break;
 146                 }
 147         }
 148         if (!intfc || intfc->num_altsetting >= nalts[i])
 149                 goto skip_to_next_interface_descriptor;
 150
 151         /* Check for duplicate altsetting entries */
 152         asnum = d->bAlternateSetting;
 153         for ((i = 0, alt = &intfc->altsetting[0]);
 154               i < intfc->num_altsetting;
 155              (++i, ++alt)) {
 156                 if (alt->desc.bAlternateSetting == asnum) {
 157                         dev_warn(ddev, "Duplicate descriptor for config %d "
 158                             "interface %d altsetting %d, skipping\n",
 159                             cfgno, inum, asnum);
 160                         goto skip_to_next_interface_descriptor;
 161                 }
 162         }
 163
 164         ++intfc->num_altsetting;
 165         memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
 166
 167         /* Skip over any Class Specific or Vendor Specific descriptors;
 168          * find the first endpoint or interface descriptor */
 169         alt->extra = buffer;
 170         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 171             USB_DT_INTERFACE, &n);
 172         alt->extralen = i;
 173         if (n > 0)
 174                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 175                     n, plural(n), "interface");
 176         buffer += i;
 177         size -= i;
 178
 179         /* Allocate space for the right(?) number of endpoints */
 180         num_ep = num_ep_orig = alt->desc.bNumEndpoints;
 181         alt->desc.bNumEndpoints = 0;            // Use as a counter
 182         if (num_ep > USB_MAXENDPOINTS) {
 183                 dev_warn(ddev, "too many endpoints for config %d interface %d "
 184                     "altsetting %d: %d, using maximum allowed: %d\n",
 185                     cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
 186                 num_ep = USB_MAXENDPOINTS;
 187         }
 188
 189         len = sizeof(struct usb_host_endpoint) * num_ep;
 190         alt->endpoint = kmalloc(len, GFP_KERNEL);
 191         if (!alt->endpoint)
 192                 return -ENOMEM;
 193         memset(alt->endpoint, 0, len);
 194
 195         /* Parse all the endpoint descriptors */
 196         n = 0;
 197         while (size > 0) {
 198                 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
 199                      == USB_DT_INTERFACE)
 200                         break;
 201                 retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
 202                     num_ep, buffer, size);
 203                 if (retval < 0)
 204                         return retval;
 205                 ++n;
 206
 207                 buffer += retval;
 208                 size -= retval;
 209         }
 210
 211         if (n != num_ep_orig)
 212                 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
 213                     "endpoint descriptor%s, different from the interface "
 214                     "descriptor's value: %d\n",
 215                     cfgno, inum, asnum, n, plural(n), num_ep_orig);
 216         return buffer - buffer0;
 217
 218 skip_to_next_interface_descriptor:
 219         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 220             USB_DT_INTERFACE, NULL);
 221         return buffer - buffer0 + i;
 222 }
 223
 224 static int usb_parse_configuration(struct device *ddev, int cfgidx,
 225     struct usb_host_config *config, unsigned char *buffer, int size)
 226 {
 227         unsigned char *buffer0 = buffer;
 228         int cfgno;
 229         int nintf, nintf_orig;
 230         int i, j, n;
 231         struct usb_interface_cache *intfc;
 232         unsigned char *buffer2;
 233         int size2;
 234         struct usb_descriptor_header *header;
 235         int len, retval;
 236         u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
 237
 238         memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
 239         if (config->desc.bDescriptorType != USB_DT_CONFIG ||
 240             config->desc.bLength < USB_DT_CONFIG_SIZE) {
 241                 dev_err(ddev, "invalid descriptor for config index %d: "
 242                     "type = 0x%X, length = %d\n", cfgidx,
 243                     config->desc.bDescriptorType, config->desc.bLength);
 244                 return -EINVAL;
 245         }
 246         cfgno = config->desc.bConfigurationValue;
 247
 248         buffer += config->desc.bLength;
 249         size -= config->desc.bLength;
 250
 251         nintf = nintf_orig = config->desc.bNumInterfaces;
 252         if (nintf > USB_MAXINTERFACES) {
 253                 dev_warn(ddev, "config %d has too many interfaces: %d, "
 254                     "using maximum allowed: %d\n",
 255                     cfgno, nintf, USB_MAXINTERFACES);
 256                 nintf = USB_MAXINTERFACES;
 257         }
 258
 259         /* Go through the descriptors, checking their length and counting the
 260          * number of altsettings for each interface */
 261         n = 0;
 262         for ((buffer2 = buffer, size2 = size);
 263               size2 > 0;
 264              (buffer2 += header->bLength, size2 -= header->bLength)) {
 265
 266                 if (size2 < sizeof(struct usb_descriptor_header)) {
 267                         dev_warn(ddev, "config %d descriptor has %d excess "
 268                             "byte%s, ignoring\n",
 269                             cfgno, size2, plural(size2));
 270                         break;
 271                 }
 272
 273                 header = (struct usb_descriptor_header *) buffer2;
 274                 if ((header->bLength > size2) || (header->bLength < 2)) {
 275                         dev_warn(ddev, "config %d has an invalid descriptor "
 276                             "of length %d, skipping remainder of the config\n",
 277                             cfgno, header->bLength);
 278                         break;
 279                 }
 280
 281                 if (header->bDescriptorType == USB_DT_INTERFACE) {
 282                         struct usb_interface_descriptor *d;
 283                         int inum;
 284
 285                         d = (struct usb_interface_descriptor *) header;
 286                         if (d->bLength < USB_DT_INTERFACE_SIZE) {
 287                                 dev_warn(ddev, "config %d has an invalid "
 288                                     "interface descriptor of length %d, "
 289                                     "skipping\n", cfgno, d->bLength);
 290                                 continue;
 291                         }
 292
 293                         inum = d->bInterfaceNumber;
 294                         if (inum >= nintf_orig)
 295                                 dev_warn(ddev, "config %d has an invalid "
 296                                     "interface number: %d but max is %d\n",
 297                                     cfgno, inum, nintf_orig - 1);
 298
 299                         /* Have we already encountered this interface?
 300                          * Count its altsettings */
 301                         for (i = 0; i < n; ++i) {
 302                                 if (inums[i] == inum)
 303                                         break;
 304                         }
 305                         if (i < n) {
 306                                 if (nalts[i] < 255)
 307                                         ++nalts[i];
 308                         } else if (n < USB_MAXINTERFACES) {
 309                                 inums[n] = inum;
 310                                 nalts[n] = 1;
 311                                 ++n;
 312                         }
 313
 314                 } else if (header->bDescriptorType == USB_DT_DEVICE ||
 315                             header->bDescriptorType == USB_DT_CONFIG)
 316                         dev_warn(ddev, "config %d contains an unexpected "
 317                             "descriptor of type 0x%X, skipping\n",
 318                             cfgno, header->bDescriptorType);
 319
 320         }       /* for ((buffer2 = buffer, size2 = size); ...) */
 321         size = buffer2 - buffer;
 322         config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
 323
 324         if (n != nintf)
 325                 dev_warn(ddev, "config %d has %d interface%s, different from "
 326                     "the descriptor's value: %d\n",
 327                     cfgno, n, plural(n), nintf_orig);
 328         else if (n == 0)
 329                 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
 330         config->desc.bNumInterfaces = nintf = n;
 331
 332         /* Check for missing interface numbers */
 333         for (i = 0; i < nintf; ++i) {
 334                 for (j = 0; j < nintf; ++j) {
 335                         if (inums[j] == i)
 336                                 break;
 337                 }
 338                 if (j >= nintf)
 339                         dev_warn(ddev, "config %d has no interface number "
 340                             "%d\n", cfgno, i);
 341         }
 342
 343         /* Allocate the usb_interface_caches and altsetting arrays */
 344         for (i = 0; i < nintf; ++i) {
 345                 j = nalts[i];
 346                 if (j > USB_MAXALTSETTING) {
 347                         dev_warn(ddev, "too many alternate settings for "
 348                             "config %d interface %d: %d, "
 349                             "using maximum allowed: %d\n",
 350                             cfgno, inums[i], j, USB_MAXALTSETTING);
 351                         nalts[i] = j = USB_MAXALTSETTING;
 352                 }
 353
 354                 len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
 355                 config->intf_cache[i] = intfc = kmalloc(len, GFP_KERNEL);
 356                 if (!intfc)
 357                         return -ENOMEM;
 358                 memset(intfc, 0, len);
 359                 kref_init(&intfc->ref);
 360         }
 361
 362         /* Skip over any Class Specific or Vendor Specific descriptors;
 363          * find the first interface descriptor */
 364         config->extra = buffer;
 365         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 366             USB_DT_INTERFACE, &n);
 367         config->extralen = i;
 368         if (n > 0)
 369                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 370                     n, plural(n), "configuration");
 371         buffer += i;
 372         size -= i;
 373
 374         /* Parse all the interface/altsetting descriptors */
 375         while (size > 0) {
 376                 retval = usb_parse_interface(ddev, cfgno, config,
 377                     buffer, size, inums, nalts);
 378                 if (retval < 0)
 379                         return retval;
 380
 381                 buffer += retval;
 382                 size -= retval;
 383         }
 384
 385         /* Check for missing altsettings */
 386         for (i = 0; i < nintf; ++i) {
 387                 intfc = config->intf_cache[i];
 388                 for (j = 0; j < intfc->num_altsetting; ++j) {
 389                         for (n = 0; n < intfc->num_altsetting; ++n) {
 390                                 if (intfc->altsetting[n].desc.
 391                                     bAlternateSetting == j)
 392                                         break;
 393                         }
 394                         if (n >= intfc->num_altsetting)
 395                                 dev_warn(ddev, "config %d interface %d has no "
 396                                     "altsetting %d\n", cfgno, inums[i], j);
 397                 }
 398         }
 399
 400         return 0;
 401 }
 402
 403 // hub-only!! ... and only exported for reset/reinit path.
 404 // otherwise used internally on disconnect/destroy path
 405 void usb_destroy_configuration(struct usb_device *dev)
 406 {
 407         int c, i;
 408
 409         if (!dev->config)
 410                 return;
 411
 412         if (dev->rawdescriptors) {
 413                 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
 414                         kfree(dev->rawdescriptors[i]);
 415
 416                 kfree(dev->rawdescriptors);
 417                 dev->rawdescriptors = NULL;
 418         }
 419
 420         for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
 421                 struct usb_host_config *cf = &dev->config[c];
 422
 423                 kfree(cf->string);
 424                 cf->string = NULL;
 425
 426                 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
 427                         if (cf->intf_cache[i])
 428                                 kref_put(&cf->intf_cache[i]->ref,
 429                                           usb_release_interface_cache);
 430                 }
 431         }
 432         kfree(dev->config);
 433         dev->config = NULL;
 434 }
 435
 436
 437 // hub-only!! ... and only in reset path, or usb_new_device()
 438 // (used by real hubs and virtual root hubs)
 439 int usb_get_configuration(struct usb_device *dev)
 440 {
 441         struct device *ddev = &dev->dev;
 442         int ncfg = dev->descriptor.bNumConfigurations;
 443         int result = -ENOMEM;
 444         unsigned int cfgno, length;
 445         unsigned char *buffer;
 446         unsigned char *bigbuffer;
 447         struct usb_config_descriptor *desc;
 448
 449         if (ncfg > USB_MAXCONFIG) {
 450                 dev_warn(ddev, "too many configurations: %d, "
 451                     "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
 452                 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
 453         }
 454
 455         if (ncfg < 1) {
 456                 dev_err(ddev, "no configurations\n");
 457                 return -EINVAL;
 458         }
 459
 460         length = ncfg * sizeof(struct usb_host_config);
 461         dev->config = kmalloc(length, GFP_KERNEL);
 462         if (!dev->config)
 463                 goto err2;
 464         memset(dev->config, 0, length);
 465
 466         length = ncfg * sizeof(char *);
 467         dev->rawdescriptors = kmalloc(length, GFP_KERNEL);
 468         if (!dev->rawdescriptors)
 469                 goto err2;
 470         memset(dev->rawdescriptors, 0, length);
 471
 472         buffer = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
 473         if (!buffer)
 474                 goto err2;
 475         desc = (struct usb_config_descriptor *)buffer;
 476
 477         for (cfgno = 0; cfgno < ncfg; cfgno++) {
 478                 /* We grab just the first descriptor so we know how long
 479                  * the whole configuration is */
 480                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 481                     buffer, USB_DT_CONFIG_SIZE);
 482                 if (result < 0) {
 483                         dev_err(ddev, "unable to read config index %d "
 484                             "descriptor/%s\n", cfgno, "start");
 485                         goto err;
 486                 } else if (result < 4) {
 487                         dev_err(ddev, "config index %d descriptor too short "
 488                             "(expected %i, got %i)\n", cfgno,
 489                             USB_DT_CONFIG_SIZE, result);
 490                         result = -EINVAL;
 491                         goto err;
 492                 }
 493                 length = max((int) le16_to_cpu(desc->wTotalLength),
 494                     USB_DT_CONFIG_SIZE);
 495
 496                 /* Now that we know the length, get the whole thing */
 497                 bigbuffer = kmalloc(length, GFP_KERNEL);
 498                 if (!bigbuffer) {
 499                         result = -ENOMEM;
 500                         goto err;
 501                 }
 502                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 503                     bigbuffer, length);
 504                 if (result < 0) {
 505                         dev_err(ddev, "unable to read config index %d "
 506                             "descriptor/%s\n", cfgno, "all");
 507                         kfree(bigbuffer);
 508                         goto err;
 509                 }
 510                 if (result < length) {
 511                         dev_warn(ddev, "config index %d descriptor too short "
 512                             "(expected %i, got %i)\n", cfgno, length, result);
 513                         length = result;
 514                 }
 515
 516                 dev->rawdescriptors[cfgno] = bigbuffer;
 517
 518                 result = usb_parse_configuration(&dev->dev, cfgno,
 519                     &dev->config[cfgno], bigbuffer, length);
 520                 if (result < 0) {
 521                         ++cfgno;
 522                         goto err;
 523                 }
 524         }
 525         result = 0;
 526
 527 err:
 528         kfree(buffer);
 529         dev->descriptor.bNumConfigurations = cfgno;
 530 err2:
 531         if (result == -ENOMEM)
 532                 dev_err(ddev, "out of memory\n");
 533         return result;
 534 }