drivers/usb/core/config.c

   1 #include <linux/usb.h>
   2 #include <linux/usb/ch9.h>
   3 #include <linux/usb/hcd.h>
   4 #include <linux/module.h>
   5 #include <linux/init.h>
   6 #include <linux/slab.h>
   7 #include <linux/device.h>
   8 #include <asm/byteorder.h>
   9 #include "usb.h"
  10
  11
  12 #define USB_MAXALTSETTING               128     /* Hard limit */
  13 #define USB_MAXENDPOINTS                30      /* Hard limit */
  14
  15 #define USB_MAXCONFIG                   8       /* Arbitrary limit */
  16
  17
  18 static inline const char *plural(int n)
  19 {
  20         return (n == 1 ? "" : "s");
  21 }
  22
  23 /* FIXME: this is a kludge */
  24 static int find_next_descriptor_more(unsigned char *buffer, int size,
  25     int dt1, int dt2, int dt3, int *num_skipped)
  26 {
  27         struct usb_descriptor_header *h;
  28         int n = 0;
  29         unsigned char *buffer0 = buffer;
  30
  31         /* Find the next descriptor of type dt1 or dt2 or dt3 */
  32         while (size > 0) {
  33                 h = (struct usb_descriptor_header *) buffer;
  34                 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2 ||
  35                                 h->bDescriptorType == dt3)
  36                         break;
  37                 buffer += h->bLength;
  38                 size -= h->bLength;
  39                 ++n;
  40         }
  41
  42         /* Store the number of descriptors skipped and return the
  43          * number of bytes skipped */
  44         if (num_skipped)
  45                 *num_skipped = n;
  46         return buffer - buffer0;
  47 }
  48
  49 static int find_next_descriptor(unsigned char *buffer, int size,
  50     int dt1, int dt2, int *num_skipped)
  51 {
  52         struct usb_descriptor_header *h;
  53         int n = 0;
  54         unsigned char *buffer0 = buffer;
  55
  56         /* Find the next descriptor of type dt1 or dt2 */
  57         while (size > 0) {
  58                 h = (struct usb_descriptor_header *) buffer;
  59                 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
  60                         break;
  61                 buffer += h->bLength;
  62                 size -= h->bLength;
  63                 ++n;
  64         }
  65
  66         /* Store the number of descriptors skipped and return the
  67          * number of bytes skipped */
  68         if (num_skipped)
  69                 *num_skipped = n;
  70         return buffer - buffer0;
  71 }
  72
  73 static int usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
  74                 int inum, int asnum, struct usb_host_endpoint *ep,
  75                 int num_ep, unsigned char *buffer, int size)
  76 {
  77         unsigned char *buffer_start = buffer;
  78         struct usb_ss_ep_comp_descriptor        *desc;
  79         int retval;
  80         int num_skipped;
  81         int max_tx;
  82         int i;
  83
  84         desc = (struct usb_ss_ep_comp_descriptor *) buffer;
  85         if (desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP) {
  86                 dev_warn(ddev, "No SuperSpeed endpoint companion for config %d "
  87                                 " interface %d altsetting %d ep %d: "
  88                                 "using minimum values\n",
  89                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
  90                 /*
  91                  * The next descriptor is for an Endpoint or Interface,
  92                  * no extra descriptors to copy into the companion structure,
  93                  * and we didn't eat up any of the buffer.
  94                  */
  95                 return 0;
  96         }
  97         memcpy(&ep->ss_ep_comp->desc, desc, USB_DT_SS_EP_COMP_SIZE);
  98         desc = &ep->ss_ep_comp->desc;
  99         buffer += desc->bLength;
 100         size -= desc->bLength;
 101
 102         /* Eat up the other descriptors we don't care about */
 103         ep->ss_ep_comp->extra = buffer;
 104         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 105                         USB_DT_INTERFACE, &num_skipped);
 106         ep->ss_ep_comp->extralen = i;
 107         buffer += i;
 108         size -= i;
 109         retval = buffer - buffer_start;
 110         if (num_skipped > 0)
 111                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 112                                 num_skipped, plural(num_skipped),
 113                                 "SuperSpeed endpoint companion");
 114
 115         /* Check the various values */
 116         if (usb_endpoint_xfer_control(&ep->desc) && desc->bMaxBurst != 0) {
 117                 dev_warn(ddev, "Control endpoint with bMaxBurst = %d in "
 118                                 "config %d interface %d altsetting %d ep %d: "
 119                                 "setting to zero\n", desc->bMaxBurst,
 120                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 121                 desc->bMaxBurst = 0;
 122         }
 123         if (desc->bMaxBurst > 15) {
 124                 dev_warn(ddev, "Endpoint with bMaxBurst = %d in "
 125                                 "config %d interface %d altsetting %d ep %d: "
 126                                 "setting to 15\n", desc->bMaxBurst,
 127                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 128                 desc->bMaxBurst = 15;
 129         }
 130         if ((usb_endpoint_xfer_control(&ep->desc) || usb_endpoint_xfer_int(&ep->desc))
 131                         && desc->bmAttributes != 0) {
 132                 dev_warn(ddev, "%s endpoint with bmAttributes = %d in "
 133                                 "config %d interface %d altsetting %d ep %d: "
 134                                 "setting to zero\n",
 135                                 usb_endpoint_xfer_control(&ep->desc) ? "Control" : "Bulk",
 136                                 desc->bmAttributes,
 137                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 138                 desc->bmAttributes = 0;
 139         }
 140         if (usb_endpoint_xfer_bulk(&ep->desc) && desc->bmAttributes > 16) {
 141                 dev_warn(ddev, "Bulk endpoint with more than 65536 streams in "
 142                                 "config %d interface %d altsetting %d ep %d: "
 143                                 "setting to max\n",
 144                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 145                 desc->bmAttributes = 16;
 146         }
 147         if (usb_endpoint_xfer_isoc(&ep->desc) && desc->bmAttributes > 2) {
 148                 dev_warn(ddev, "Isoc endpoint has Mult of %d in "
 149                                 "config %d interface %d altsetting %d ep %d: "
 150                                 "setting to 3\n", desc->bmAttributes + 1,
 151                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 152                 desc->bmAttributes = 2;
 153         }
 154         if (usb_endpoint_xfer_isoc(&ep->desc)) {
 155                 max_tx = ep->desc.wMaxPacketSize * (desc->bMaxBurst + 1) *
 156                         (desc->bmAttributes + 1);
 157         } else if (usb_endpoint_xfer_int(&ep->desc)) {
 158                 max_tx = ep->desc.wMaxPacketSize * (desc->bMaxBurst + 1);
 159         } else {
 160                 goto valid;
 161         }
 162         if (desc->wBytesPerInterval > max_tx) {
 163                 dev_warn(ddev, "%s endpoint with wBytesPerInterval of %d in "
 164                                 "config %d interface %d altsetting %d ep %d: "
 165                                 "setting to %d\n",
 166                                 usb_endpoint_xfer_isoc(&ep->desc) ? "Isoc" : "Int",
 167                                 desc->wBytesPerInterval,
 168                                 cfgno, inum, asnum, ep->desc.bEndpointAddress,
 169                                 max_tx);
 170                 desc->wBytesPerInterval = max_tx;
 171         }
 172 valid:
 173         return retval;
 174 }
 175
 176 static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
 177     int asnum, struct usb_host_interface *ifp, int num_ep,
 178     unsigned char *buffer, int size)
 179 {
 180         unsigned char *buffer0 = buffer;
 181         struct usb_endpoint_descriptor *d;
 182         struct usb_host_endpoint *endpoint;
 183         int n, i, j, retval;
 184
 185         d = (struct usb_endpoint_descriptor *) buffer;
 186         buffer += d->bLength;
 187         size -= d->bLength;
 188
 189         if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
 190                 n = USB_DT_ENDPOINT_AUDIO_SIZE;
 191         else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
 192                 n = USB_DT_ENDPOINT_SIZE;
 193         else {
 194                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 195                     "invalid endpoint descriptor of length %d, skipping\n",
 196                     cfgno, inum, asnum, d->bLength);
 197                 goto skip_to_next_endpoint_or_interface_descriptor;
 198         }
 199
 200         i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
 201         if (i >= 16 || i == 0) {
 202                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 203                     "invalid endpoint with address 0x%X, skipping\n",
 204                     cfgno, inum, asnum, d->bEndpointAddress);
 205                 goto skip_to_next_endpoint_or_interface_descriptor;
 206         }
 207
 208         /* Only store as many endpoints as we have room for */
 209         if (ifp->desc.bNumEndpoints >= num_ep)
 210                 goto skip_to_next_endpoint_or_interface_descriptor;
 211
 212         endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
 213         ++ifp->desc.bNumEndpoints;
 214
 215         memcpy(&endpoint->desc, d, n);
 216         INIT_LIST_HEAD(&endpoint->urb_list);
 217
 218         /* Fix up bInterval values outside the legal range. Use 32 ms if no
 219          * proper value can be guessed. */
 220         i = 0;          /* i = min, j = max, n = default */
 221         j = 255;
 222         if (usb_endpoint_xfer_int(d)) {
 223                 i = 1;
 224                 switch (to_usb_device(ddev)->speed) {
 225                 case USB_SPEED_SUPER:
 226                 case USB_SPEED_HIGH:
 227                         /* Many device manufacturers are using full-speed
 228                          * bInterval values in high-speed interrupt endpoint
 229                          * descriptors. Try to fix those and fall back to a
 230                          * 32 ms default value otherwise. */
 231                         n = fls(d->bInterval*8);
 232                         if (n == 0)
 233                                 n = 9;  /* 32 ms = 2^(9-1) uframes */
 234                         j = 16;
 235                         break;
 236                 default:                /* USB_SPEED_FULL or _LOW */
 237                         /* For low-speed, 10 ms is the official minimum.
 238                          * But some "overclocked" devices might want faster
 239                          * polling so we'll allow it. */
 240                         n = 32;
 241                         break;
 242                 }
 243         } else if (usb_endpoint_xfer_isoc(d)) {
 244                 i = 1;
 245                 j = 16;
 246                 switch (to_usb_device(ddev)->speed) {
 247                 case USB_SPEED_HIGH:
 248                         n = 9;          /* 32 ms = 2^(9-1) uframes */
 249                         break;
 250                 default:                /* USB_SPEED_FULL */
 251                         n = 6;          /* 32 ms = 2^(6-1) frames */
 252                         break;
 253                 }
 254         }
 255         if (d->bInterval < i || d->bInterval > j) {
 256                 dev_warn(ddev, "config %d interface %d altsetting %d "
 257                     "endpoint 0x%X has an invalid bInterval %d, "
 258                     "changing to %d\n",
 259                     cfgno, inum, asnum,
 260                     d->bEndpointAddress, d->bInterval, n);
 261                 endpoint->desc.bInterval = n;
 262         }
 263
 264         /* Some buggy low-speed devices have Bulk endpoints, which is
 265          * explicitly forbidden by the USB spec.  In an attempt to make
 266          * them usable, we will try treating them as Interrupt endpoints.
 267          */
 268         if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
 269                         usb_endpoint_xfer_bulk(d)) {
 270                 dev_warn(ddev, "config %d interface %d altsetting %d "
 271                     "endpoint 0x%X is Bulk; changing to Interrupt\n",
 272                     cfgno, inum, asnum, d->bEndpointAddress);
 273                 endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
 274                 endpoint->desc.bInterval = 1;
 275                 if (le16_to_cpu(endpoint->desc.wMaxPacketSize) > 8)
 276                         endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
 277         }
 278
 279         /*
 280          * Some buggy high speed devices have bulk endpoints using
 281          * maxpacket sizes other than 512.  High speed HCDs may not
 282          * be able to handle that particular bug, so let's warn...
 283          */
 284         if (to_usb_device(ddev)->speed == USB_SPEED_HIGH
 285                         && usb_endpoint_xfer_bulk(d)) {
 286                 unsigned maxp;
 287
 288                 maxp = le16_to_cpu(endpoint->desc.wMaxPacketSize) & 0x07ff;
 289                 if (maxp != 512)
 290                         dev_warn(ddev, "config %d interface %d altsetting %d "
 291                                 "bulk endpoint 0x%X has invalid maxpacket %d\n",
 292                                 cfgno, inum, asnum, d->bEndpointAddress,
 293                                 maxp);
 294         }
 295         /* Allocate room for and parse any SS endpoint companion descriptors */
 296         if (to_usb_device(ddev)->speed == USB_SPEED_SUPER) {
 297                 endpoint->extra = buffer;
 298                 i = find_next_descriptor_more(buffer, size, USB_DT_SS_ENDPOINT_COMP,
 299                                 USB_DT_ENDPOINT, USB_DT_INTERFACE, &n);
 300                 endpoint->extralen = i;
 301                 buffer += i;
 302                 size -= i;
 303
 304                 /* Allocate space for the SS endpoint companion descriptor */
 305                 endpoint->ss_ep_comp = kzalloc(sizeof(struct usb_host_ss_ep_comp),
 306                                 GFP_KERNEL);
 307                 if (!endpoint->ss_ep_comp)
 308                         return -ENOMEM;
 309
 310                 /* Fill in some default values (may be overwritten later) */
 311                 endpoint->ss_ep_comp->desc.bLength = USB_DT_SS_EP_COMP_SIZE;
 312                 endpoint->ss_ep_comp->desc.bDescriptorType = USB_DT_SS_ENDPOINT_COMP;
 313                 endpoint->ss_ep_comp->desc.bMaxBurst = 0;
 314                 /*
 315                  * Leave bmAttributes as zero, which will mean no streams for
 316                  * bulk, and isoc won't support multiple bursts of packets.
 317                  * With bursts of only one packet, and a Mult of 1, the max
 318                  * amount of data moved per endpoint service interval is one
 319                  * packet.
 320                  */
 321                 if (usb_endpoint_xfer_isoc(&endpoint->desc) ||
 322                                 usb_endpoint_xfer_int(&endpoint->desc))
 323                         endpoint->ss_ep_comp->desc.wBytesPerInterval =
 324                                 endpoint->desc.wMaxPacketSize;
 325
 326                 if (size > 0) {
 327                         retval = usb_parse_ss_endpoint_companion(ddev, cfgno,
 328                                         inum, asnum, endpoint, num_ep, buffer,
 329                                         size);
 330                         if (retval >= 0) {
 331                                 buffer += retval;
 332                                 retval = buffer - buffer0;
 333                         }
 334                 } else {
 335                         dev_warn(ddev, "config %d interface %d altsetting %d "
 336                                 "endpoint 0x%X has no "
 337                                 "SuperSpeed companion descriptor\n",
 338                                 cfgno, inum, asnum, d->bEndpointAddress);
 339                         retval = buffer - buffer0;
 340                 }
 341         } else {
 342                 /* Skip over any Class Specific or Vendor Specific descriptors;
 343                  * find the next endpoint or interface descriptor */
 344                 endpoint->extra = buffer;
 345                 i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 346                                 USB_DT_INTERFACE, &n);
 347                 endpoint->extralen = i;
 348                 retval = buffer - buffer0 + i;
 349         }
 350         if (n > 0)
 351                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 352                     n, plural(n), "endpoint");
 353         return retval;
 354
 355 skip_to_next_endpoint_or_interface_descriptor:
 356         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 357             USB_DT_INTERFACE, NULL);
 358         return buffer - buffer0 + i;
 359 }
 360
 361 void usb_release_interface_cache(struct kref *ref)
 362 {
 363         struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
 364         int j;
 365
 366         for (j = 0; j < intfc->num_altsetting; j++) {
 367                 struct usb_host_interface *alt = &intfc->altsetting[j];
 368
 369                 kfree(alt->endpoint);
 370                 kfree(alt->string);
 371         }
 372         kfree(intfc);
 373 }
 374
 375 static int usb_parse_interface(struct device *ddev, int cfgno,
 376     struct usb_host_config *config, unsigned char *buffer, int size,
 377     u8 inums[], u8 nalts[])
 378 {
 379         unsigned char *buffer0 = buffer;
 380         struct usb_interface_descriptor *d;
 381         int inum, asnum;
 382         struct usb_interface_cache *intfc;
 383         struct usb_host_interface *alt;
 384         int i, n;
 385         int len, retval;
 386         int num_ep, num_ep_orig;
 387
 388         d = (struct usb_interface_descriptor *) buffer;
 389         buffer += d->bLength;
 390         size -= d->bLength;
 391
 392         if (d->bLength < USB_DT_INTERFACE_SIZE)
 393                 goto skip_to_next_interface_descriptor;
 394
 395         /* Which interface entry is this? */
 396         intfc = NULL;
 397         inum = d->bInterfaceNumber;
 398         for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 399                 if (inums[i] == inum) {
 400                         intfc = config->intf_cache[i];
 401                         break;
 402                 }
 403         }
 404         if (!intfc || intfc->num_altsetting >= nalts[i])
 405                 goto skip_to_next_interface_descriptor;
 406
 407         /* Check for duplicate altsetting entries */
 408         asnum = d->bAlternateSetting;
 409         for ((i = 0, alt = &intfc->altsetting[0]);
 410               i < intfc->num_altsetting;
 411              (++i, ++alt)) {
 412                 if (alt->desc.bAlternateSetting == asnum) {
 413                         dev_warn(ddev, "Duplicate descriptor for config %d "
 414                             "interface %d altsetting %d, skipping\n",
 415                             cfgno, inum, asnum);
 416                         goto skip_to_next_interface_descriptor;
 417                 }
 418         }
 419
 420         ++intfc->num_altsetting;
 421         memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
 422
 423         /* Skip over any Class Specific or Vendor Specific descriptors;
 424          * find the first endpoint or interface descriptor */
 425         alt->extra = buffer;
 426         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 427             USB_DT_INTERFACE, &n);
 428         alt->extralen = i;
 429         if (n > 0)
 430                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 431                     n, plural(n), "interface");
 432         buffer += i;
 433         size -= i;
 434
 435         /* Allocate space for the right(?) number of endpoints */
 436         num_ep = num_ep_orig = alt->desc.bNumEndpoints;
 437         alt->desc.bNumEndpoints = 0;            /* Use as a counter */
 438         if (num_ep > USB_MAXENDPOINTS) {
 439                 dev_warn(ddev, "too many endpoints for config %d interface %d "
 440                     "altsetting %d: %d, using maximum allowed: %d\n",
 441                     cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
 442                 num_ep = USB_MAXENDPOINTS;
 443         }
 444
 445         if (num_ep > 0) {
 446                 /* Can't allocate 0 bytes */
 447                 len = sizeof(struct usb_host_endpoint) * num_ep;
 448                 alt->endpoint = kzalloc(len, GFP_KERNEL);
 449                 if (!alt->endpoint)
 450                         return -ENOMEM;
 451         }
 452
 453         /* Parse all the endpoint descriptors */
 454         n = 0;
 455         while (size > 0) {
 456                 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
 457                      == USB_DT_INTERFACE)
 458                         break;
 459                 retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
 460                     num_ep, buffer, size);
 461                 if (retval < 0)
 462                         return retval;
 463                 ++n;
 464
 465                 buffer += retval;
 466                 size -= retval;
 467         }
 468
 469         if (n != num_ep_orig)
 470                 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
 471                     "endpoint descriptor%s, different from the interface "
 472                     "descriptor's value: %d\n",
 473                     cfgno, inum, asnum, n, plural(n), num_ep_orig);
 474         return buffer - buffer0;
 475
 476 skip_to_next_interface_descriptor:
 477         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 478             USB_DT_INTERFACE, NULL);
 479         return buffer - buffer0 + i;
 480 }
 481
 482 static int usb_parse_configuration(struct device *ddev, int cfgidx,
 483     struct usb_host_config *config, unsigned char *buffer, int size)
 484 {
 485         unsigned char *buffer0 = buffer;
 486         int cfgno;
 487         int nintf, nintf_orig;
 488         int i, j, n;
 489         struct usb_interface_cache *intfc;
 490         unsigned char *buffer2;
 491         int size2;
 492         struct usb_descriptor_header *header;
 493         int len, retval;
 494         u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
 495         unsigned iad_num = 0;
 496
 497         memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
 498         if (config->desc.bDescriptorType != USB_DT_CONFIG ||
 499             config->desc.bLength < USB_DT_CONFIG_SIZE) {
 500                 dev_err(ddev, "invalid descriptor for config index %d: "
 501                     "type = 0x%X, length = %d\n", cfgidx,
 502                     config->desc.bDescriptorType, config->desc.bLength);
 503                 return -EINVAL;
 504         }
 505         cfgno = config->desc.bConfigurationValue;
 506
 507         buffer += config->desc.bLength;
 508         size -= config->desc.bLength;
 509
 510         nintf = nintf_orig = config->desc.bNumInterfaces;
 511         if (nintf > USB_MAXINTERFACES) {
 512                 dev_warn(ddev, "config %d has too many interfaces: %d, "
 513                     "using maximum allowed: %d\n",
 514                     cfgno, nintf, USB_MAXINTERFACES);
 515                 nintf = USB_MAXINTERFACES;
 516         }
 517
 518         /* Go through the descriptors, checking their length and counting the
 519          * number of altsettings for each interface */
 520         n = 0;
 521         for ((buffer2 = buffer, size2 = size);
 522               size2 > 0;
 523              (buffer2 += header->bLength, size2 -= header->bLength)) {
 524
 525                 if (size2 < sizeof(struct usb_descriptor_header)) {
 526                         dev_warn(ddev, "config %d descriptor has %d excess "
 527                             "byte%s, ignoring\n",
 528                             cfgno, size2, plural(size2));
 529                         break;
 530                 }
 531
 532                 header = (struct usb_descriptor_header *) buffer2;
 533                 if ((header->bLength > size2) || (header->bLength < 2)) {
 534                         dev_warn(ddev, "config %d has an invalid descriptor "
 535                             "of length %d, skipping remainder of the config\n",
 536                             cfgno, header->bLength);
 537                         break;
 538                 }
 539
 540                 if (header->bDescriptorType == USB_DT_INTERFACE) {
 541                         struct usb_interface_descriptor *d;
 542                         int inum;
 543
 544                         d = (struct usb_interface_descriptor *) header;
 545                         if (d->bLength < USB_DT_INTERFACE_SIZE) {
 546                                 dev_warn(ddev, "config %d has an invalid "
 547                                     "interface descriptor of length %d, "
 548                                     "skipping\n", cfgno, d->bLength);
 549                                 continue;
 550                         }
 551
 552                         inum = d->bInterfaceNumber;
 553                         if (inum >= nintf_orig)
 554                                 dev_warn(ddev, "config %d has an invalid "
 555                                     "interface number: %d but max is %d\n",
 556                                     cfgno, inum, nintf_orig - 1);
 557
 558                         /* Have we already encountered this interface?
 559                          * Count its altsettings */
 560                         for (i = 0; i < n; ++i) {
 561                                 if (inums[i] == inum)
 562                                         break;
 563                         }
 564                         if (i < n) {
 565                                 if (nalts[i] < 255)
 566                                         ++nalts[i];
 567                         } else if (n < USB_MAXINTERFACES) {
 568                                 inums[n] = inum;
 569                                 nalts[n] = 1;
 570                                 ++n;
 571                         }
 572
 573                 } else if (header->bDescriptorType ==
 574                                 USB_DT_INTERFACE_ASSOCIATION) {
 575                         if (iad_num == USB_MAXIADS) {
 576                                 dev_warn(ddev, "found more Interface "
 577                                                "Association Descriptors "
 578                                                "than allocated for in "
 579                                                "configuration %d\n", cfgno);
 580                         } else {
 581                                 config->intf_assoc[iad_num] =
 582                                         (struct usb_interface_assoc_descriptor
 583                                         *)header;
 584                                 iad_num++;
 585                         }
 586
 587                 } else if (header->bDescriptorType == USB_DT_DEVICE ||
 588                             header->bDescriptorType == USB_DT_CONFIG)
 589                         dev_warn(ddev, "config %d contains an unexpected "
 590                             "descriptor of type 0x%X, skipping\n",
 591                             cfgno, header->bDescriptorType);
 592
 593         }       /* for ((buffer2 = buffer, size2 = size); ...) */
 594         size = buffer2 - buffer;
 595         config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
 596
 597         if (n != nintf)
 598                 dev_warn(ddev, "config %d has %d interface%s, different from "
 599                     "the descriptor's value: %d\n",
 600                     cfgno, n, plural(n), nintf_orig);
 601         else if (n == 0)
 602                 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
 603         config->desc.bNumInterfaces = nintf = n;
 604
 605         /* Check for missing interface numbers */
 606         for (i = 0; i < nintf; ++i) {
 607                 for (j = 0; j < nintf; ++j) {
 608                         if (inums[j] == i)
 609                                 break;
 610                 }
 611                 if (j >= nintf)
 612                         dev_warn(ddev, "config %d has no interface number "
 613                             "%d\n", cfgno, i);
 614         }
 615
 616         /* Allocate the usb_interface_caches and altsetting arrays */
 617         for (i = 0; i < nintf; ++i) {
 618                 j = nalts[i];
 619                 if (j > USB_MAXALTSETTING) {
 620                         dev_warn(ddev, "too many alternate settings for "
 621                             "config %d interface %d: %d, "
 622                             "using maximum allowed: %d\n",
 623                             cfgno, inums[i], j, USB_MAXALTSETTING);
 624                         nalts[i] = j = USB_MAXALTSETTING;
 625                 }
 626
 627                 len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
 628                 config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
 629                 if (!intfc)
 630                         return -ENOMEM;
 631                 kref_init(&intfc->ref);
 632         }
 633
 634         /* FIXME: parse the BOS descriptor */
 635
 636         /* Skip over any Class Specific or Vendor Specific descriptors;
 637          * find the first interface descriptor */
 638         config->extra = buffer;
 639         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 640             USB_DT_INTERFACE, &n);
 641         config->extralen = i;
 642         if (n > 0)
 643                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 644                     n, plural(n), "configuration");
 645         buffer += i;
 646         size -= i;
 647
 648         /* Parse all the interface/altsetting descriptors */
 649         while (size > 0) {
 650                 retval = usb_parse_interface(ddev, cfgno, config,
 651                     buffer, size, inums, nalts);
 652                 if (retval < 0)
 653                         return retval;
 654
 655                 buffer += retval;
 656                 size -= retval;
 657         }
 658
 659         /* Check for missing altsettings */
 660         for (i = 0; i < nintf; ++i) {
 661                 intfc = config->intf_cache[i];
 662                 for (j = 0; j < intfc->num_altsetting; ++j) {
 663                         for (n = 0; n < intfc->num_altsetting; ++n) {
 664                                 if (intfc->altsetting[n].desc.
 665                                     bAlternateSetting == j)
 666                                         break;
 667                         }
 668                         if (n >= intfc->num_altsetting)
 669                                 dev_warn(ddev, "config %d interface %d has no "
 670                                     "altsetting %d\n", cfgno, inums[i], j);
 671                 }
 672         }
 673
 674         return 0;
 675 }
 676
 677 /* hub-only!! ... and only exported for reset/reinit path.
 678  * otherwise used internally on disconnect/destroy path
 679  */
 680 void usb_destroy_configuration(struct usb_device *dev)
 681 {
 682         int c, i;
 683
 684         if (!dev->config)
 685                 return;
 686
 687         if (dev->rawdescriptors) {
 688                 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
 689                         kfree(dev->rawdescriptors[i]);
 690
 691                 kfree(dev->rawdescriptors);
 692                 dev->rawdescriptors = NULL;
 693         }
 694
 695         for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
 696                 struct usb_host_config *cf = &dev->config[c];
 697
 698                 kfree(cf->string);
 699                 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
 700                         if (cf->intf_cache[i])
 701                                 kref_put(&cf->intf_cache[i]->ref,
 702                                           usb_release_interface_cache);
 703                 }
 704         }
 705         kfree(dev->config);
 706         dev->config = NULL;
 707 }
 708
 709
 710 /*
 711  * Get the USB config descriptors, cache and parse'em
 712  *
 713  * hub-only!! ... and only in reset path, or usb_new_device()
 714  * (used by real hubs and virtual root hubs)
 715  *
 716  * NOTE: if this is a WUSB device and is not authorized, we skip the
 717  *       whole thing. A non-authorized USB device has no
 718  *       configurations.
 719  */
 720 int usb_get_configuration(struct usb_device *dev)
 721 {
 722         struct device *ddev = &dev->dev;
 723         int ncfg = dev->descriptor.bNumConfigurations;
 724         int result = 0;
 725         unsigned int cfgno, length;
 726         unsigned char *buffer;
 727         unsigned char *bigbuffer;
 728         struct usb_config_descriptor *desc;
 729
 730         cfgno = 0;
 731         if (dev->authorized == 0)       /* Not really an error */
 732                 goto out_not_authorized;
 733         result = -ENOMEM;
 734         if (ncfg > USB_MAXCONFIG) {
 735                 dev_warn(ddev, "too many configurations: %d, "
 736                     "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
 737                 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
 738         }
 739
 740         if (ncfg < 1) {
 741                 dev_err(ddev, "no configurations\n");
 742                 return -EINVAL;
 743         }
 744
 745         length = ncfg * sizeof(struct usb_host_config);
 746         dev->config = kzalloc(length, GFP_KERNEL);
 747         if (!dev->config)
 748                 goto err2;
 749
 750         length = ncfg * sizeof(char *);
 751         dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
 752         if (!dev->rawdescriptors)
 753                 goto err2;
 754
 755         buffer = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
 756         if (!buffer)
 757                 goto err2;
 758         desc = (struct usb_config_descriptor *)buffer;
 759
 760         result = 0;
 761         for (; cfgno < ncfg; cfgno++) {
 762                 /* We grab just the first descriptor so we know how long
 763                  * the whole configuration is */
 764                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 765                     buffer, USB_DT_CONFIG_SIZE);
 766                 if (result < 0) {
 767                         dev_err(ddev, "unable to read config index %d "
 768                             "descriptor/%s: %d\n", cfgno, "start", result);
 769                         dev_err(ddev, "chopping to %d config(s)\n", cfgno);
 770                         dev->descriptor.bNumConfigurations = cfgno;
 771                         break;
 772                 } else if (result < 4) {
 773                         dev_err(ddev, "config index %d descriptor too short "
 774                             "(expected %i, got %i)\n", cfgno,
 775                             USB_DT_CONFIG_SIZE, result);
 776                         result = -EINVAL;
 777                         goto err;
 778                 }
 779                 length = max((int) le16_to_cpu(desc->wTotalLength),
 780                     USB_DT_CONFIG_SIZE);
 781
 782                 /* Now that we know the length, get the whole thing */
 783                 bigbuffer = kmalloc(length, GFP_KERNEL);
 784                 if (!bigbuffer) {
 785                         result = -ENOMEM;
 786                         goto err;
 787                 }
 788                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 789                     bigbuffer, length);
 790                 if (result < 0) {
 791                         dev_err(ddev, "unable to read config index %d "
 792                             "descriptor/%s\n", cfgno, "all");
 793                         kfree(bigbuffer);
 794                         goto err;
 795                 }
 796                 if (result < length) {
 797                         dev_warn(ddev, "config index %d descriptor too short "
 798                             "(expected %i, got %i)\n", cfgno, length, result);
 799                         length = result;
 800                 }
 801
 802                 dev->rawdescriptors[cfgno] = bigbuffer;
 803
 804                 result = usb_parse_configuration(&dev->dev, cfgno,
 805                     &dev->config[cfgno], bigbuffer, length);
 806                 if (result < 0) {
 807                         ++cfgno;
 808                         goto err;
 809                 }
 810         }
 811         result = 0;
 812
 813 err:
 814         kfree(buffer);
 815 out_not_authorized:
 816         dev->descriptor.bNumConfigurations = cfgno;
 817 err2:
 818         if (result == -ENOMEM)
 819                 dev_err(ddev, "out of memory\n");
 820         return result;
 821 }