drivers/usb/core/config.c

   1 #include <linux/usb.h>
   2 #include <linux/usb/ch9.h>
   3 #include <linux/module.h>
   4 #include <linux/init.h>
   5 #include <linux/slab.h>
   6 #include <linux/device.h>
   7 #include <asm/byteorder.h>
   8 #include "usb.h"
   9 #include "hcd.h"
  10
  11 #define USB_MAXALTSETTING               128     /* Hard limit */
  12 #define USB_MAXENDPOINTS                30      /* Hard limit */
  13
  14 #define USB_MAXCONFIG                   8       /* Arbitrary limit */
  15
  16
  17 static inline const char *plural(int n)
  18 {
  19         return (n == 1 ? "" : "s");
  20 }
  21
  22 /* FIXME: this is a kludge */
  23 static int find_next_descriptor_more(unsigned char *buffer, int size,
  24     int dt1, int dt2, int dt3, int *num_skipped)
  25 {
  26         struct usb_descriptor_header *h;
  27         int n = 0;
  28         unsigned char *buffer0 = buffer;
  29
  30         /* Find the next descriptor of type dt1 or dt2 or dt3 */
  31         while (size > 0) {
  32                 h = (struct usb_descriptor_header *) buffer;
  33                 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2 ||
  34                                 h->bDescriptorType == dt3)
  35                         break;
  36                 buffer += h->bLength;
  37                 size -= h->bLength;
  38                 ++n;
  39         }
  40
  41         /* Store the number of descriptors skipped and return the
  42          * number of bytes skipped */
  43         if (num_skipped)
  44                 *num_skipped = n;
  45         return buffer - buffer0;
  46 }
  47
  48 static int find_next_descriptor(unsigned char *buffer, int size,
  49     int dt1, int dt2, int *num_skipped)
  50 {
  51         struct usb_descriptor_header *h;
  52         int n = 0;
  53         unsigned char *buffer0 = buffer;
  54
  55         /* Find the next descriptor of type dt1 or dt2 */
  56         while (size > 0) {
  57                 h = (struct usb_descriptor_header *) buffer;
  58                 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
  59                         break;
  60                 buffer += h->bLength;
  61                 size -= h->bLength;
  62                 ++n;
  63         }
  64
  65         /* Store the number of descriptors skipped and return the
  66          * number of bytes skipped */
  67         if (num_skipped)
  68                 *num_skipped = n;
  69         return buffer - buffer0;
  70 }
  71
  72 static int usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
  73                 int inum, int asnum, struct usb_host_endpoint *ep,
  74                 int num_ep, unsigned char *buffer, int size)
  75 {
  76         unsigned char *buffer_start = buffer;
  77         struct usb_ss_ep_comp_descriptor        *desc;
  78         int retval;
  79         int num_skipped;
  80         int max_tx;
  81         int i;
  82
  83         desc = (struct usb_ss_ep_comp_descriptor *) buffer;
  84         if (desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP) {
  85                 dev_warn(ddev, "No SuperSpeed endpoint companion for config %d "
  86                                 " interface %d altsetting %d ep %d: "
  87                                 "using minimum values\n",
  88                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
  89                 /*
  90                  * The next descriptor is for an Endpoint or Interface,
  91                  * no extra descriptors to copy into the companion structure,
  92                  * and we didn't eat up any of the buffer.
  93                  */
  94                 return 0;
  95         }
  96         memcpy(&ep->ss_ep_comp->desc, desc, USB_DT_SS_EP_COMP_SIZE);
  97         desc = &ep->ss_ep_comp->desc;
  98         buffer += desc->bLength;
  99         size -= desc->bLength;
 100
 101         /* Eat up the other descriptors we don't care about */
 102         ep->ss_ep_comp->extra = buffer;
 103         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 104                         USB_DT_INTERFACE, &num_skipped);
 105         ep->ss_ep_comp->extralen = i;
 106         buffer += i;
 107         size -= i;
 108         retval = buffer - buffer_start;
 109         if (num_skipped > 0)
 110                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 111                                 num_skipped, plural(num_skipped),
 112                                 "SuperSpeed endpoint companion");
 113
 114         /* Check the various values */
 115         if (usb_endpoint_xfer_control(&ep->desc) && desc->bMaxBurst != 0) {
 116                 dev_warn(ddev, "Control endpoint with bMaxBurst = %d in "
 117                                 "config %d interface %d altsetting %d ep %d: "
 118                                 "setting to zero\n", desc->bMaxBurst,
 119                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 120                 desc->bMaxBurst = 0;
 121         }
 122         if (desc->bMaxBurst > 15) {
 123                 dev_warn(ddev, "Endpoint with bMaxBurst = %d in "
 124                                 "config %d interface %d altsetting %d ep %d: "
 125                                 "setting to 15\n", desc->bMaxBurst,
 126                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 127                 desc->bMaxBurst = 15;
 128         }
 129         if ((usb_endpoint_xfer_control(&ep->desc) || usb_endpoint_xfer_int(&ep->desc))
 130                         && desc->bmAttributes != 0) {
 131                 dev_warn(ddev, "%s endpoint with bmAttributes = %d in "
 132                                 "config %d interface %d altsetting %d ep %d: "
 133                                 "setting to zero\n",
 134                                 usb_endpoint_xfer_control(&ep->desc) ? "Control" : "Bulk",
 135                                 desc->bmAttributes,
 136                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 137                 desc->bmAttributes = 0;
 138         }
 139         if (usb_endpoint_xfer_bulk(&ep->desc) && desc->bmAttributes > 16) {
 140                 dev_warn(ddev, "Bulk endpoint with more than 65536 streams in "
 141                                 "config %d interface %d altsetting %d ep %d: "
 142                                 "setting to max\n",
 143                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 144                 desc->bmAttributes = 16;
 145         }
 146         if (usb_endpoint_xfer_isoc(&ep->desc) && desc->bmAttributes > 2) {
 147                 dev_warn(ddev, "Isoc endpoint has Mult of %d in "
 148                                 "config %d interface %d altsetting %d ep %d: "
 149                                 "setting to 3\n", desc->bmAttributes + 1,
 150                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 151                 desc->bmAttributes = 2;
 152         }
 153         if (usb_endpoint_xfer_isoc(&ep->desc)) {
 154                 max_tx = ep->desc.wMaxPacketSize * (desc->bMaxBurst + 1) *
 155                         (desc->bmAttributes + 1);
 156         } else if (usb_endpoint_xfer_int(&ep->desc)) {
 157                 max_tx = ep->desc.wMaxPacketSize * (desc->bMaxBurst + 1);
 158         } else {
 159                 goto valid;
 160         }
 161         if (desc->wBytesPerInterval > max_tx) {
 162                 dev_warn(ddev, "%s endpoint with wBytesPerInterval of %d in "
 163                                 "config %d interface %d altsetting %d ep %d: "
 164                                 "setting to %d\n",
 165                                 usb_endpoint_xfer_isoc(&ep->desc) ? "Isoc" : "Int",
 166                                 desc->wBytesPerInterval,
 167                                 cfgno, inum, asnum, ep->desc.bEndpointAddress,
 168                                 max_tx);
 169                 desc->wBytesPerInterval = max_tx;
 170         }
 171 valid:
 172         return retval;
 173 }
 174
 175 static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
 176     int asnum, struct usb_host_interface *ifp, int num_ep,
 177     unsigned char *buffer, int size)
 178 {
 179         unsigned char *buffer0 = buffer;
 180         struct usb_endpoint_descriptor *d;
 181         struct usb_host_endpoint *endpoint;
 182         int n, i, j, retval;
 183
 184         d = (struct usb_endpoint_descriptor *) buffer;
 185         buffer += d->bLength;
 186         size -= d->bLength;
 187
 188         if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
 189                 n = USB_DT_ENDPOINT_AUDIO_SIZE;
 190         else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
 191                 n = USB_DT_ENDPOINT_SIZE;
 192         else {
 193                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 194                     "invalid endpoint descriptor of length %d, skipping\n",
 195                     cfgno, inum, asnum, d->bLength);
 196                 goto skip_to_next_endpoint_or_interface_descriptor;
 197         }
 198
 199         i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
 200         if (i >= 16 || i == 0) {
 201                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 202                     "invalid endpoint with address 0x%X, skipping\n",
 203                     cfgno, inum, asnum, d->bEndpointAddress);
 204                 goto skip_to_next_endpoint_or_interface_descriptor;
 205         }
 206
 207         /* Only store as many endpoints as we have room for */
 208         if (ifp->desc.bNumEndpoints >= num_ep)
 209                 goto skip_to_next_endpoint_or_interface_descriptor;
 210
 211         endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
 212         ++ifp->desc.bNumEndpoints;
 213
 214         memcpy(&endpoint->desc, d, n);
 215         INIT_LIST_HEAD(&endpoint->urb_list);
 216
 217         /* Fix up bInterval values outside the legal range. Use 32 ms if no
 218          * proper value can be guessed. */
 219         i = 0;          /* i = min, j = max, n = default */
 220         j = 255;
 221         if (usb_endpoint_xfer_int(d)) {
 222                 i = 1;
 223                 switch (to_usb_device(ddev)->speed) {
 224                 case USB_SPEED_SUPER:
 225                 case USB_SPEED_HIGH:
 226                         /* Many device manufacturers are using full-speed
 227                          * bInterval values in high-speed interrupt endpoint
 228                          * descriptors. Try to fix those and fall back to a
 229                          * 32 ms default value otherwise. */
 230                         n = fls(d->bInterval*8);
 231                         if (n == 0)
 232                                 n = 9;  /* 32 ms = 2^(9-1) uframes */
 233                         j = 16;
 234                         break;
 235                 default:                /* USB_SPEED_FULL or _LOW */
 236                         /* For low-speed, 10 ms is the official minimum.
 237                          * But some "overclocked" devices might want faster
 238                          * polling so we'll allow it. */
 239                         n = 32;
 240                         break;
 241                 }
 242         } else if (usb_endpoint_xfer_isoc(d)) {
 243                 i = 1;
 244                 j = 16;
 245                 switch (to_usb_device(ddev)->speed) {
 246                 case USB_SPEED_HIGH:
 247                         n = 9;          /* 32 ms = 2^(9-1) uframes */
 248                         break;
 249                 default:                /* USB_SPEED_FULL */
 250                         n = 6;          /* 32 ms = 2^(6-1) frames */
 251                         break;
 252                 }
 253         }
 254         if (d->bInterval < i || d->bInterval > j) {
 255                 dev_warn(ddev, "config %d interface %d altsetting %d "
 256                     "endpoint 0x%X has an invalid bInterval %d, "
 257                     "changing to %d\n",
 258                     cfgno, inum, asnum,
 259                     d->bEndpointAddress, d->bInterval, n);
 260                 endpoint->desc.bInterval = n;
 261         }
 262
 263         /* Some buggy low-speed devices have Bulk endpoints, which is
 264          * explicitly forbidden by the USB spec.  In an attempt to make
 265          * them usable, we will try treating them as Interrupt endpoints.
 266          */
 267         if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
 268                         usb_endpoint_xfer_bulk(d)) {
 269                 dev_warn(ddev, "config %d interface %d altsetting %d "
 270                     "endpoint 0x%X is Bulk; changing to Interrupt\n",
 271                     cfgno, inum, asnum, d->bEndpointAddress);
 272                 endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
 273                 endpoint->desc.bInterval = 1;
 274                 if (le16_to_cpu(endpoint->desc.wMaxPacketSize) > 8)
 275                         endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
 276         }
 277
 278         /*
 279          * Some buggy high speed devices have bulk endpoints using
 280          * maxpacket sizes other than 512.  High speed HCDs may not
 281          * be able to handle that particular bug, so let's warn...
 282          */
 283         if (to_usb_device(ddev)->speed == USB_SPEED_HIGH
 284                         && usb_endpoint_xfer_bulk(d)) {
 285                 unsigned maxp;
 286
 287                 maxp = le16_to_cpu(endpoint->desc.wMaxPacketSize) & 0x07ff;
 288                 if (maxp != 512)
 289                         dev_warn(ddev, "config %d interface %d altsetting %d "
 290                                 "bulk endpoint 0x%X has invalid maxpacket %d\n",
 291                                 cfgno, inum, asnum, d->bEndpointAddress,
 292                                 maxp);
 293         }
 294         /* Allocate room for and parse any SS endpoint companion descriptors */
 295         if (to_usb_device(ddev)->speed == USB_SPEED_SUPER) {
 296                 endpoint->extra = buffer;
 297                 i = find_next_descriptor_more(buffer, size, USB_DT_SS_ENDPOINT_COMP,
 298                                 USB_DT_ENDPOINT, USB_DT_INTERFACE, &n);
 299                 endpoint->extralen = i;
 300                 buffer += i;
 301                 size -= i;
 302
 303                 /* Allocate space for the SS endpoint companion descriptor */
 304                 endpoint->ss_ep_comp = kzalloc(sizeof(struct usb_host_ss_ep_comp),
 305                                 GFP_KERNEL);
 306                 if (!endpoint->ss_ep_comp)
 307                         return -ENOMEM;
 308
 309                 /* Fill in some default values (may be overwritten later) */
 310                 endpoint->ss_ep_comp->desc.bLength = USB_DT_SS_EP_COMP_SIZE;
 311                 endpoint->ss_ep_comp->desc.bDescriptorType = USB_DT_SS_ENDPOINT_COMP;
 312                 endpoint->ss_ep_comp->desc.bMaxBurst = 0;
 313                 /*
 314                  * Leave bmAttributes as zero, which will mean no streams for
 315                  * bulk, and isoc won't support multiple bursts of packets.
 316                  * With bursts of only one packet, and a Mult of 1, the max
 317                  * amount of data moved per endpoint service interval is one
 318                  * packet.
 319                  */
 320                 if (usb_endpoint_xfer_isoc(&endpoint->desc) ||
 321                                 usb_endpoint_xfer_int(&endpoint->desc))
 322                         endpoint->ss_ep_comp->desc.wBytesPerInterval =
 323                                 endpoint->desc.wMaxPacketSize;
 324
 325                 if (size > 0) {
 326                         retval = usb_parse_ss_endpoint_companion(ddev, cfgno,
 327                                         inum, asnum, endpoint, num_ep, buffer,
 328                                         size);
 329                         if (retval >= 0) {
 330                                 buffer += retval;
 331                                 retval = buffer - buffer0;
 332                         }
 333                 } else {
 334                         dev_warn(ddev, "config %d interface %d altsetting %d "
 335                                 "endpoint 0x%X has no "
 336                                 "SuperSpeed companion descriptor\n",
 337                                 cfgno, inum, asnum, d->bEndpointAddress);
 338                         retval = buffer - buffer0;
 339                 }
 340         } else {
 341                 /* Skip over any Class Specific or Vendor Specific descriptors;
 342                  * find the next endpoint or interface descriptor */
 343                 endpoint->extra = buffer;
 344                 i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 345                                 USB_DT_INTERFACE, &n);
 346                 endpoint->extralen = i;
 347                 retval = buffer - buffer0 + i;
 348         }
 349         if (n > 0)
 350                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 351                     n, plural(n), "endpoint");
 352         return retval;
 353
 354 skip_to_next_endpoint_or_interface_descriptor:
 355         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 356             USB_DT_INTERFACE, NULL);
 357         return buffer - buffer0 + i;
 358 }
 359
 360 void usb_release_interface_cache(struct kref *ref)
 361 {
 362         struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
 363         int j;
 364
 365         for (j = 0; j < intfc->num_altsetting; j++) {
 366                 struct usb_host_interface *alt = &intfc->altsetting[j];
 367
 368                 kfree(alt->endpoint);
 369                 kfree(alt->string);
 370         }
 371         kfree(intfc);
 372 }
 373
 374 static int usb_parse_interface(struct device *ddev, int cfgno,
 375     struct usb_host_config *config, unsigned char *buffer, int size,
 376     u8 inums[], u8 nalts[])
 377 {
 378         unsigned char *buffer0 = buffer;
 379         struct usb_interface_descriptor *d;
 380         int inum, asnum;
 381         struct usb_interface_cache *intfc;
 382         struct usb_host_interface *alt;
 383         int i, n;
 384         int len, retval;
 385         int num_ep, num_ep_orig;
 386
 387         d = (struct usb_interface_descriptor *) buffer;
 388         buffer += d->bLength;
 389         size -= d->bLength;
 390
 391         if (d->bLength < USB_DT_INTERFACE_SIZE)
 392                 goto skip_to_next_interface_descriptor;
 393
 394         /* Which interface entry is this? */
 395         intfc = NULL;
 396         inum = d->bInterfaceNumber;
 397         for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 398                 if (inums[i] == inum) {
 399                         intfc = config->intf_cache[i];
 400                         break;
 401                 }
 402         }
 403         if (!intfc || intfc->num_altsetting >= nalts[i])
 404                 goto skip_to_next_interface_descriptor;
 405
 406         /* Check for duplicate altsetting entries */
 407         asnum = d->bAlternateSetting;
 408         for ((i = 0, alt = &intfc->altsetting[0]);
 409               i < intfc->num_altsetting;
 410              (++i, ++alt)) {
 411                 if (alt->desc.bAlternateSetting == asnum) {
 412                         dev_warn(ddev, "Duplicate descriptor for config %d "
 413                             "interface %d altsetting %d, skipping\n",
 414                             cfgno, inum, asnum);
 415                         goto skip_to_next_interface_descriptor;
 416                 }
 417         }
 418
 419         ++intfc->num_altsetting;
 420         memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
 421
 422         /* Skip over any Class Specific or Vendor Specific descriptors;
 423          * find the first endpoint or interface descriptor */
 424         alt->extra = buffer;
 425         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 426             USB_DT_INTERFACE, &n);
 427         alt->extralen = i;
 428         if (n > 0)
 429                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 430                     n, plural(n), "interface");
 431         buffer += i;
 432         size -= i;
 433
 434         /* Allocate space for the right(?) number of endpoints */
 435         num_ep = num_ep_orig = alt->desc.bNumEndpoints;
 436         alt->desc.bNumEndpoints = 0;            /* Use as a counter */
 437         if (num_ep > USB_MAXENDPOINTS) {
 438                 dev_warn(ddev, "too many endpoints for config %d interface %d "
 439                     "altsetting %d: %d, using maximum allowed: %d\n",
 440                     cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
 441                 num_ep = USB_MAXENDPOINTS;
 442         }
 443
 444         if (num_ep > 0) {
 445                 /* Can't allocate 0 bytes */
 446                 len = sizeof(struct usb_host_endpoint) * num_ep;
 447                 alt->endpoint = kzalloc(len, GFP_KERNEL);
 448                 if (!alt->endpoint)
 449                         return -ENOMEM;
 450         }
 451
 452         /* Parse all the endpoint descriptors */
 453         n = 0;
 454         while (size > 0) {
 455                 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
 456                      == USB_DT_INTERFACE)
 457                         break;
 458                 retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
 459                     num_ep, buffer, size);
 460                 if (retval < 0)
 461                         return retval;
 462                 ++n;
 463
 464                 buffer += retval;
 465                 size -= retval;
 466         }
 467
 468         if (n != num_ep_orig)
 469                 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
 470                     "endpoint descriptor%s, different from the interface "
 471                     "descriptor's value: %d\n",
 472                     cfgno, inum, asnum, n, plural(n), num_ep_orig);
 473         return buffer - buffer0;
 474
 475 skip_to_next_interface_descriptor:
 476         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 477             USB_DT_INTERFACE, NULL);
 478         return buffer - buffer0 + i;
 479 }
 480
 481 static int usb_parse_configuration(struct device *ddev, int cfgidx,
 482     struct usb_host_config *config, unsigned char *buffer, int size)
 483 {
 484         unsigned char *buffer0 = buffer;
 485         int cfgno;
 486         int nintf, nintf_orig;
 487         int i, j, n;
 488         struct usb_interface_cache *intfc;
 489         unsigned char *buffer2;
 490         int size2;
 491         struct usb_descriptor_header *header;
 492         int len, retval;
 493         u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
 494         unsigned iad_num = 0;
 495
 496         memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
 497         if (config->desc.bDescriptorType != USB_DT_CONFIG ||
 498             config->desc.bLength < USB_DT_CONFIG_SIZE) {
 499                 dev_err(ddev, "invalid descriptor for config index %d: "
 500                     "type = 0x%X, length = %d\n", cfgidx,
 501                     config->desc.bDescriptorType, config->desc.bLength);
 502                 return -EINVAL;
 503         }
 504         cfgno = config->desc.bConfigurationValue;
 505
 506         buffer += config->desc.bLength;
 507         size -= config->desc.bLength;
 508
 509         nintf = nintf_orig = config->desc.bNumInterfaces;
 510         if (nintf > USB_MAXINTERFACES) {
 511                 dev_warn(ddev, "config %d has too many interfaces: %d, "
 512                     "using maximum allowed: %d\n",
 513                     cfgno, nintf, USB_MAXINTERFACES);
 514                 nintf = USB_MAXINTERFACES;
 515         }
 516
 517         /* Go through the descriptors, checking their length and counting the
 518          * number of altsettings for each interface */
 519         n = 0;
 520         for ((buffer2 = buffer, size2 = size);
 521               size2 > 0;
 522              (buffer2 += header->bLength, size2 -= header->bLength)) {
 523
 524                 if (size2 < sizeof(struct usb_descriptor_header)) {
 525                         dev_warn(ddev, "config %d descriptor has %d excess "
 526                             "byte%s, ignoring\n",
 527                             cfgno, size2, plural(size2));
 528                         break;
 529                 }
 530
 531                 header = (struct usb_descriptor_header *) buffer2;
 532                 if ((header->bLength > size2) || (header->bLength < 2)) {
 533                         dev_warn(ddev, "config %d has an invalid descriptor "
 534                             "of length %d, skipping remainder of the config\n",
 535                             cfgno, header->bLength);
 536                         break;
 537                 }
 538
 539                 if (header->bDescriptorType == USB_DT_INTERFACE) {
 540                         struct usb_interface_descriptor *d;
 541                         int inum;
 542
 543                         d = (struct usb_interface_descriptor *) header;
 544                         if (d->bLength < USB_DT_INTERFACE_SIZE) {
 545                                 dev_warn(ddev, "config %d has an invalid "
 546                                     "interface descriptor of length %d, "
 547                                     "skipping\n", cfgno, d->bLength);
 548                                 continue;
 549                         }
 550
 551                         inum = d->bInterfaceNumber;
 552                         if (inum >= nintf_orig)
 553                                 dev_warn(ddev, "config %d has an invalid "
 554                                     "interface number: %d but max is %d\n",
 555                                     cfgno, inum, nintf_orig - 1);
 556
 557                         /* Have we already encountered this interface?
 558                          * Count its altsettings */
 559                         for (i = 0; i < n; ++i) {
 560                                 if (inums[i] == inum)
 561                                         break;
 562                         }
 563                         if (i < n) {
 564                                 if (nalts[i] < 255)
 565                                         ++nalts[i];
 566                         } else if (n < USB_MAXINTERFACES) {
 567                                 inums[n] = inum;
 568                                 nalts[n] = 1;
 569                                 ++n;
 570                         }
 571
 572                 } else if (header->bDescriptorType ==
 573                                 USB_DT_INTERFACE_ASSOCIATION) {
 574                         if (iad_num == USB_MAXIADS) {
 575                                 dev_warn(ddev, "found more Interface "
 576                                                "Association Descriptors "
 577                                                "than allocated for in "
 578                                                "configuration %d\n", cfgno);
 579                         } else {
 580                                 config->intf_assoc[iad_num] =
 581                                         (struct usb_interface_assoc_descriptor
 582                                         *)header;
 583                                 iad_num++;
 584                         }
 585
 586                 } else if (header->bDescriptorType == USB_DT_DEVICE ||
 587                             header->bDescriptorType == USB_DT_CONFIG)
 588                         dev_warn(ddev, "config %d contains an unexpected "
 589                             "descriptor of type 0x%X, skipping\n",
 590                             cfgno, header->bDescriptorType);
 591
 592         }       /* for ((buffer2 = buffer, size2 = size); ...) */
 593         size = buffer2 - buffer;
 594         config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
 595
 596         if (n != nintf)
 597                 dev_warn(ddev, "config %d has %d interface%s, different from "
 598                     "the descriptor's value: %d\n",
 599                     cfgno, n, plural(n), nintf_orig);
 600         else if (n == 0)
 601                 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
 602         config->desc.bNumInterfaces = nintf = n;
 603
 604         /* Check for missing interface numbers */
 605         for (i = 0; i < nintf; ++i) {
 606                 for (j = 0; j < nintf; ++j) {
 607                         if (inums[j] == i)
 608                                 break;
 609                 }
 610                 if (j >= nintf)
 611                         dev_warn(ddev, "config %d has no interface number "
 612                             "%d\n", cfgno, i);
 613         }
 614
 615         /* Allocate the usb_interface_caches and altsetting arrays */
 616         for (i = 0; i < nintf; ++i) {
 617                 j = nalts[i];
 618                 if (j > USB_MAXALTSETTING) {
 619                         dev_warn(ddev, "too many alternate settings for "
 620                             "config %d interface %d: %d, "
 621                             "using maximum allowed: %d\n",
 622                             cfgno, inums[i], j, USB_MAXALTSETTING);
 623                         nalts[i] = j = USB_MAXALTSETTING;
 624                 }
 625
 626                 len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
 627                 config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
 628                 if (!intfc)
 629                         return -ENOMEM;
 630                 kref_init(&intfc->ref);
 631         }
 632
 633         /* FIXME: parse the BOS descriptor */
 634
 635         /* Skip over any Class Specific or Vendor Specific descriptors;
 636          * find the first interface descriptor */
 637         config->extra = buffer;
 638         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 639             USB_DT_INTERFACE, &n);
 640         config->extralen = i;
 641         if (n > 0)
 642                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 643                     n, plural(n), "configuration");
 644         buffer += i;
 645         size -= i;
 646
 647         /* Parse all the interface/altsetting descriptors */
 648         while (size > 0) {
 649                 retval = usb_parse_interface(ddev, cfgno, config,
 650                     buffer, size, inums, nalts);
 651                 if (retval < 0)
 652                         return retval;
 653
 654                 buffer += retval;
 655                 size -= retval;
 656         }
 657
 658         /* Check for missing altsettings */
 659         for (i = 0; i < nintf; ++i) {
 660                 intfc = config->intf_cache[i];
 661                 for (j = 0; j < intfc->num_altsetting; ++j) {
 662                         for (n = 0; n < intfc->num_altsetting; ++n) {
 663                                 if (intfc->altsetting[n].desc.
 664                                     bAlternateSetting == j)
 665                                         break;
 666                         }
 667                         if (n >= intfc->num_altsetting)
 668                                 dev_warn(ddev, "config %d interface %d has no "
 669                                     "altsetting %d\n", cfgno, inums[i], j);
 670                 }
 671         }
 672
 673         return 0;
 674 }
 675
 676 /* hub-only!! ... and only exported for reset/reinit path.
 677  * otherwise used internally on disconnect/destroy path
 678  */
 679 void usb_destroy_configuration(struct usb_device *dev)
 680 {
 681         int c, i;
 682
 683         if (!dev->config)
 684                 return;
 685
 686         if (dev->rawdescriptors) {
 687                 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
 688                         kfree(dev->rawdescriptors[i]);
 689
 690                 kfree(dev->rawdescriptors);
 691                 dev->rawdescriptors = NULL;
 692         }
 693
 694         for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
 695                 struct usb_host_config *cf = &dev->config[c];
 696
 697                 kfree(cf->string);
 698                 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
 699                         if (cf->intf_cache[i])
 700                                 kref_put(&cf->intf_cache[i]->ref,
 701                                           usb_release_interface_cache);
 702                 }
 703         }
 704         kfree(dev->config);
 705         dev->config = NULL;
 706 }
 707
 708
 709 /*
 710  * Get the USB config descriptors, cache and parse'em
 711  *
 712  * hub-only!! ... and only in reset path, or usb_new_device()
 713  * (used by real hubs and virtual root hubs)
 714  *
 715  * NOTE: if this is a WUSB device and is not authorized, we skip the
 716  *       whole thing. A non-authorized USB device has no
 717  *       configurations.
 718  */
 719 int usb_get_configuration(struct usb_device *dev)
 720 {
 721         struct device *ddev = &dev->dev;
 722         int ncfg = dev->descriptor.bNumConfigurations;
 723         int result = 0;
 724         unsigned int cfgno, length;
 725         unsigned char *buffer;
 726         unsigned char *bigbuffer;
 727         struct usb_config_descriptor *desc;
 728
 729         cfgno = 0;
 730         if (dev->authorized == 0)       /* Not really an error */
 731                 goto out_not_authorized;
 732         result = -ENOMEM;
 733         if (ncfg > USB_MAXCONFIG) {
 734                 dev_warn(ddev, "too many configurations: %d, "
 735                     "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
 736                 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
 737         }
 738
 739         if (ncfg < 1) {
 740                 dev_err(ddev, "no configurations\n");
 741                 return -EINVAL;
 742         }
 743
 744         length = ncfg * sizeof(struct usb_host_config);
 745         dev->config = kzalloc(length, GFP_KERNEL);
 746         if (!dev->config)
 747                 goto err2;
 748
 749         length = ncfg * sizeof(char *);
 750         dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
 751         if (!dev->rawdescriptors)
 752                 goto err2;
 753
 754         buffer = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
 755         if (!buffer)
 756                 goto err2;
 757         desc = (struct usb_config_descriptor *)buffer;
 758
 759         result = 0;
 760         for (; cfgno < ncfg; cfgno++) {
 761                 /* We grab just the first descriptor so we know how long
 762                  * the whole configuration is */
 763                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 764                     buffer, USB_DT_CONFIG_SIZE);
 765                 if (result < 0) {
 766                         dev_err(ddev, "unable to read config index %d "
 767                             "descriptor/%s: %d\n", cfgno, "start", result);
 768                         dev_err(ddev, "chopping to %d config(s)\n", cfgno);
 769                         dev->descriptor.bNumConfigurations = cfgno;
 770                         break;
 771                 } else if (result < 4) {
 772                         dev_err(ddev, "config index %d descriptor too short "
 773                             "(expected %i, got %i)\n", cfgno,
 774                             USB_DT_CONFIG_SIZE, result);
 775                         result = -EINVAL;
 776                         goto err;
 777                 }
 778                 length = max((int) le16_to_cpu(desc->wTotalLength),
 779                     USB_DT_CONFIG_SIZE);
 780
 781                 /* Now that we know the length, get the whole thing */
 782                 bigbuffer = kmalloc(length, GFP_KERNEL);
 783                 if (!bigbuffer) {
 784                         result = -ENOMEM;
 785                         goto err;
 786                 }
 787                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 788                     bigbuffer, length);
 789                 if (result < 0) {
 790                         dev_err(ddev, "unable to read config index %d "
 791                             "descriptor/%s\n", cfgno, "all");
 792                         kfree(bigbuffer);
 793                         goto err;
 794                 }
 795                 if (result < length) {
 796                         dev_warn(ddev, "config index %d descriptor too short "
 797                             "(expected %i, got %i)\n", cfgno, length, result);
 798                         length = result;
 799                 }
 800
 801                 dev->rawdescriptors[cfgno] = bigbuffer;
 802
 803                 result = usb_parse_configuration(&dev->dev, cfgno,
 804                     &dev->config[cfgno], bigbuffer, length);
 805                 if (result < 0) {
 806                         ++cfgno;
 807                         goto err;
 808                 }
 809         }
 810         result = 0;
 811
 812 err:
 813         kfree(buffer);
 814 out_not_authorized:
 815         dev->descriptor.bNumConfigurations = cfgno;
 816 err2:
 817         if (result == -ENOMEM)
 818                 dev_err(ddev, "out of memory\n");
 819         return result;
 820 }