drivers/usb/core/config.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Released under the GPLv2 only.
   4  */
   5
   6 #include <linux/usb.h>
   7 #include <linux/usb/ch9.h>
   8 #include <linux/usb/hcd.h>
   9 #include <linux/usb/quirks.h>
  10 #include <linux/module.h>
  11 #include <linux/slab.h>
  12 #include <linux/device.h>
  13 #include <asm/byteorder.h>
  14 #include "usb.h"
  15
  16
  17 #define USB_MAXALTSETTING               128     /* Hard limit */
  18
  19 #define USB_MAXCONFIG                   8       /* Arbitrary limit */
  20
  21
  22 static inline const char *plural(int n)
  23 {
  24         return (n == 1 ? "" : "s");
  25 }
  26
  27 static int find_next_descriptor(unsigned char *buffer, int size,
  28     int dt1, int dt2, int *num_skipped)
  29 {
  30         struct usb_descriptor_header *h;
  31         int n = 0;
  32         unsigned char *buffer0 = buffer;
  33
  34         /* Find the next descriptor of type dt1 or dt2 */
  35         while (size > 0) {
  36                 h = (struct usb_descriptor_header *) buffer;
  37                 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
  38                         break;
  39                 buffer += h->bLength;
  40                 size -= h->bLength;
  41                 ++n;
  42         }
  43
  44         /* Store the number of descriptors skipped and return the
  45          * number of bytes skipped */
  46         if (num_skipped)
  47                 *num_skipped = n;
  48         return buffer - buffer0;
  49 }
  50
  51 static void usb_parse_ssp_isoc_endpoint_companion(struct device *ddev,
  52                 int cfgno, int inum, int asnum, struct usb_host_endpoint *ep,
  53                 unsigned char *buffer, int size)
  54 {
  55         struct usb_ssp_isoc_ep_comp_descriptor *desc;
  56
  57         /*
  58          * The SuperSpeedPlus Isoc endpoint companion descriptor immediately
  59          * follows the SuperSpeed Endpoint Companion descriptor
  60          */
  61         desc = (struct usb_ssp_isoc_ep_comp_descriptor *) buffer;
  62         if (desc->bDescriptorType != USB_DT_SSP_ISOC_ENDPOINT_COMP ||
  63             size < USB_DT_SSP_ISOC_EP_COMP_SIZE) {
  64                 dev_warn(ddev, "Invalid SuperSpeedPlus isoc endpoint companion"
  65                          "for config %d interface %d altsetting %d ep %d.\n",
  66                          cfgno, inum, asnum, ep->desc.bEndpointAddress);
  67                 return;
  68         }
  69         memcpy(&ep->ssp_isoc_ep_comp, desc, USB_DT_SSP_ISOC_EP_COMP_SIZE);
  70 }
  71
  72 static void usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
  73                 int inum, int asnum, struct usb_host_endpoint *ep,
  74                 unsigned char *buffer, int size)
  75 {
  76         struct usb_ss_ep_comp_descriptor *desc;
  77         int max_tx;
  78
  79         /* The SuperSpeed endpoint companion descriptor is supposed to
  80          * be the first thing immediately following the endpoint descriptor.
  81          */
  82         desc = (struct usb_ss_ep_comp_descriptor *) buffer;
  83
  84         if (desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP ||
  85                         size < USB_DT_SS_EP_COMP_SIZE) {
  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                 /* Fill in some default values.
  92                  * Leave bmAttributes as zero, which will mean no streams for
  93                  * bulk, and isoc won't support multiple bursts of packets.
  94                  * With bursts of only one packet, and a Mult of 1, the max
  95                  * amount of data moved per endpoint service interval is one
  96                  * packet.
  97                  */
  98                 ep->ss_ep_comp.bLength = USB_DT_SS_EP_COMP_SIZE;
  99                 ep->ss_ep_comp.bDescriptorType = USB_DT_SS_ENDPOINT_COMP;
 100                 if (usb_endpoint_xfer_isoc(&ep->desc) ||
 101                                 usb_endpoint_xfer_int(&ep->desc))
 102                         ep->ss_ep_comp.wBytesPerInterval =
 103                                         ep->desc.wMaxPacketSize;
 104                 return;
 105         }
 106         buffer += desc->bLength;
 107         size -= desc->bLength;
 108         memcpy(&ep->ss_ep_comp, desc, USB_DT_SS_EP_COMP_SIZE);
 109
 110         /* Check the various values */
 111         if (usb_endpoint_xfer_control(&ep->desc) && desc->bMaxBurst != 0) {
 112                 dev_warn(ddev, "Control endpoint with bMaxBurst = %d in "
 113                                 "config %d interface %d altsetting %d ep %d: "
 114                                 "setting to zero\n", desc->bMaxBurst,
 115                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 116                 ep->ss_ep_comp.bMaxBurst = 0;
 117         } else if (desc->bMaxBurst > 15) {
 118                 dev_warn(ddev, "Endpoint with bMaxBurst = %d in "
 119                                 "config %d interface %d altsetting %d ep %d: "
 120                                 "setting to 15\n", desc->bMaxBurst,
 121                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 122                 ep->ss_ep_comp.bMaxBurst = 15;
 123         }
 124
 125         if ((usb_endpoint_xfer_control(&ep->desc) ||
 126                         usb_endpoint_xfer_int(&ep->desc)) &&
 127                                 desc->bmAttributes != 0) {
 128                 dev_warn(ddev, "%s endpoint with bmAttributes = %d in "
 129                                 "config %d interface %d altsetting %d ep %d: "
 130                                 "setting to zero\n",
 131                                 usb_endpoint_xfer_control(&ep->desc) ? "Control" : "Bulk",
 132                                 desc->bmAttributes,
 133                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 134                 ep->ss_ep_comp.bmAttributes = 0;
 135         } else if (usb_endpoint_xfer_bulk(&ep->desc) &&
 136                         desc->bmAttributes > 16) {
 137                 dev_warn(ddev, "Bulk endpoint with more than 65536 streams in "
 138                                 "config %d interface %d altsetting %d ep %d: "
 139                                 "setting to max\n",
 140                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 141                 ep->ss_ep_comp.bmAttributes = 16;
 142         } else if (usb_endpoint_xfer_isoc(&ep->desc) &&
 143                    !USB_SS_SSP_ISOC_COMP(desc->bmAttributes) &&
 144                    USB_SS_MULT(desc->bmAttributes) > 3) {
 145                 dev_warn(ddev, "Isoc endpoint has Mult of %d in "
 146                                 "config %d interface %d altsetting %d ep %d: "
 147                                 "setting to 3\n",
 148                                 USB_SS_MULT(desc->bmAttributes),
 149                                 cfgno, inum, asnum, ep->desc.bEndpointAddress);
 150                 ep->ss_ep_comp.bmAttributes = 2;
 151         }
 152
 153         if (usb_endpoint_xfer_isoc(&ep->desc))
 154                 max_tx = (desc->bMaxBurst + 1) *
 155                         (USB_SS_MULT(desc->bmAttributes)) *
 156                         usb_endpoint_maxp(&ep->desc);
 157         else if (usb_endpoint_xfer_int(&ep->desc))
 158                 max_tx = usb_endpoint_maxp(&ep->desc) *
 159                         (desc->bMaxBurst + 1);
 160         else
 161                 max_tx = 999999;
 162         if (le16_to_cpu(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                                 le16_to_cpu(desc->wBytesPerInterval),
 168                                 cfgno, inum, asnum, ep->desc.bEndpointAddress,
 169                                 max_tx);
 170                 ep->ss_ep_comp.wBytesPerInterval = cpu_to_le16(max_tx);
 171         }
 172         /* Parse a possible SuperSpeedPlus isoc ep companion descriptor */
 173         if (usb_endpoint_xfer_isoc(&ep->desc) &&
 174             USB_SS_SSP_ISOC_COMP(desc->bmAttributes))
 175                 usb_parse_ssp_isoc_endpoint_companion(ddev, cfgno, inum, asnum,
 176                                                         ep, buffer, size);
 177 }
 178
 179 static const unsigned short low_speed_maxpacket_maxes[4] = {
 180         [USB_ENDPOINT_XFER_CONTROL] = 8,
 181         [USB_ENDPOINT_XFER_ISOC] = 0,
 182         [USB_ENDPOINT_XFER_BULK] = 0,
 183         [USB_ENDPOINT_XFER_INT] = 8,
 184 };
 185 static const unsigned short full_speed_maxpacket_maxes[4] = {
 186         [USB_ENDPOINT_XFER_CONTROL] = 64,
 187         [USB_ENDPOINT_XFER_ISOC] = 1023,
 188         [USB_ENDPOINT_XFER_BULK] = 64,
 189         [USB_ENDPOINT_XFER_INT] = 64,
 190 };
 191 static const unsigned short high_speed_maxpacket_maxes[4] = {
 192         [USB_ENDPOINT_XFER_CONTROL] = 64,
 193         [USB_ENDPOINT_XFER_ISOC] = 1024,
 194
 195         /* Bulk should be 512, but some devices use 1024: we will warn below */
 196         [USB_ENDPOINT_XFER_BULK] = 1024,
 197         [USB_ENDPOINT_XFER_INT] = 1024,
 198 };
 199 static const unsigned short super_speed_maxpacket_maxes[4] = {
 200         [USB_ENDPOINT_XFER_CONTROL] = 512,
 201         [USB_ENDPOINT_XFER_ISOC] = 1024,
 202         [USB_ENDPOINT_XFER_BULK] = 1024,
 203         [USB_ENDPOINT_XFER_INT] = 1024,
 204 };
 205
 206 static bool endpoint_is_duplicate(struct usb_endpoint_descriptor *e1,
 207                 struct usb_endpoint_descriptor *e2)
 208 {
 209         if (e1->bEndpointAddress == e2->bEndpointAddress)
 210                 return true;
 211
 212         if (usb_endpoint_xfer_control(e1) || usb_endpoint_xfer_control(e2)) {
 213                 if (usb_endpoint_num(e1) == usb_endpoint_num(e2))
 214                         return true;
 215         }
 216
 217         return false;
 218 }
 219
 220 /*
 221  * Check for duplicate endpoint addresses in other interfaces and in the
 222  * altsetting currently being parsed.
 223  */
 224 static bool config_endpoint_is_duplicate(struct usb_host_config *config,
 225                 int inum, int asnum, struct usb_endpoint_descriptor *d)
 226 {
 227         struct usb_endpoint_descriptor *epd;
 228         struct usb_interface_cache *intfc;
 229         struct usb_host_interface *alt;
 230         int i, j, k;
 231
 232         for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 233                 intfc = config->intf_cache[i];
 234
 235                 for (j = 0; j < intfc->num_altsetting; ++j) {
 236                         alt = &intfc->altsetting[j];
 237
 238                         if (alt->desc.bInterfaceNumber == inum &&
 239                                         alt->desc.bAlternateSetting != asnum)
 240                                 continue;
 241
 242                         for (k = 0; k < alt->desc.bNumEndpoints; ++k) {
 243                                 epd = &alt->endpoint[k].desc;
 244
 245                                 if (endpoint_is_duplicate(epd, d))
 246                                         return true;
 247                         }
 248                 }
 249         }
 250
 251         return false;
 252 }
 253
 254 static int usb_parse_endpoint(struct device *ddev, int cfgno,
 255                 struct usb_host_config *config, int inum, int asnum,
 256                 struct usb_host_interface *ifp, int num_ep,
 257                 unsigned char *buffer, int size)
 258 {
 259         struct usb_device *udev = to_usb_device(ddev);
 260         unsigned char *buffer0 = buffer;
 261         struct usb_endpoint_descriptor *d;
 262         struct usb_host_endpoint *endpoint;
 263         int n, i, j, retval;
 264         unsigned int maxp;
 265         const unsigned short *maxpacket_maxes;
 266
 267         d = (struct usb_endpoint_descriptor *) buffer;
 268         buffer += d->bLength;
 269         size -= d->bLength;
 270
 271         if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
 272                 n = USB_DT_ENDPOINT_AUDIO_SIZE;
 273         else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
 274                 n = USB_DT_ENDPOINT_SIZE;
 275         else {
 276                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 277                     "invalid endpoint descriptor of length %d, skipping\n",
 278                     cfgno, inum, asnum, d->bLength);
 279                 goto skip_to_next_endpoint_or_interface_descriptor;
 280         }
 281
 282         i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
 283         if (i >= 16 || i == 0) {
 284                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 285                     "invalid endpoint with address 0x%X, skipping\n",
 286                     cfgno, inum, asnum, d->bEndpointAddress);
 287                 goto skip_to_next_endpoint_or_interface_descriptor;
 288         }
 289
 290         /* Only store as many endpoints as we have room for */
 291         if (ifp->desc.bNumEndpoints >= num_ep)
 292                 goto skip_to_next_endpoint_or_interface_descriptor;
 293
 294         /* Check for duplicate endpoint addresses */
 295         if (config_endpoint_is_duplicate(config, inum, asnum, d)) {
 296                 dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n",
 297                                 cfgno, inum, asnum, d->bEndpointAddress);
 298                 goto skip_to_next_endpoint_or_interface_descriptor;
 299         }
 300
 301         /* Ignore some endpoints */
 302         if (udev->quirks & USB_QUIRK_ENDPOINT_IGNORE) {
 303                 if (usb_endpoint_is_ignored(udev, ifp, d)) {
 304                         dev_warn(ddev, "config %d interface %d altsetting %d has an ignored endpoint with address 0x%X, skipping\n",
 305                                         cfgno, inum, asnum,
 306                                         d->bEndpointAddress);
 307                         goto skip_to_next_endpoint_or_interface_descriptor;
 308                 }
 309         }
 310
 311         endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
 312         ++ifp->desc.bNumEndpoints;
 313
 314         memcpy(&endpoint->desc, d, n);
 315         INIT_LIST_HEAD(&endpoint->urb_list);
 316
 317         /*
 318          * Fix up bInterval values outside the legal range.
 319          * Use 10 or 8 ms if no proper value can be guessed.
 320          */
 321         i = 0;          /* i = min, j = max, n = default */
 322         j = 255;
 323         if (usb_endpoint_xfer_int(d)) {
 324                 i = 1;
 325                 switch (udev->speed) {
 326                 case USB_SPEED_SUPER_PLUS:
 327                 case USB_SPEED_SUPER:
 328                 case USB_SPEED_HIGH:
 329                         /*
 330                          * Many device manufacturers are using full-speed
 331                          * bInterval values in high-speed interrupt endpoint
 332                          * descriptors. Try to fix those and fall back to an
 333                          * 8-ms default value otherwise.
 334                          */
 335                         n = fls(d->bInterval*8);
 336                         if (n == 0)
 337                                 n = 7;  /* 8 ms = 2^(7-1) uframes */
 338                         j = 16;
 339
 340                         /*
 341                          * Adjust bInterval for quirked devices.
 342                          */
 343                         /*
 344                          * This quirk fixes bIntervals reported in ms.
 345                          */
 346                         if (udev->quirks & USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL) {
 347                                 n = clamp(fls(d->bInterval) + 3, i, j);
 348                                 i = j = n;
 349                         }
 350                         /*
 351                          * This quirk fixes bIntervals reported in
 352                          * linear microframes.
 353                          */
 354                         if (udev->quirks & USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL) {
 355                                 n = clamp(fls(d->bInterval), i, j);
 356                                 i = j = n;
 357                         }
 358                         break;
 359                 default:                /* USB_SPEED_FULL or _LOW */
 360                         /*
 361                          * For low-speed, 10 ms is the official minimum.
 362                          * But some "overclocked" devices might want faster
 363                          * polling so we'll allow it.
 364                          */
 365                         n = 10;
 366                         break;
 367                 }
 368         } else if (usb_endpoint_xfer_isoc(d)) {
 369                 i = 1;
 370                 j = 16;
 371                 switch (udev->speed) {
 372                 case USB_SPEED_HIGH:
 373                         n = 7;          /* 8 ms = 2^(7-1) uframes */
 374                         break;
 375                 default:                /* USB_SPEED_FULL */
 376                         n = 4;          /* 8 ms = 2^(4-1) frames */
 377                         break;
 378                 }
 379         }
 380         if (d->bInterval < i || d->bInterval > j) {
 381                 dev_warn(ddev, "config %d interface %d altsetting %d "
 382                     "endpoint 0x%X has an invalid bInterval %d, "
 383                     "changing to %d\n",
 384                     cfgno, inum, asnum,
 385                     d->bEndpointAddress, d->bInterval, n);
 386                 endpoint->desc.bInterval = n;
 387         }
 388
 389         /* Some buggy low-speed devices have Bulk endpoints, which is
 390          * explicitly forbidden by the USB spec.  In an attempt to make
 391          * them usable, we will try treating them as Interrupt endpoints.
 392          */
 393         if (udev->speed == USB_SPEED_LOW && usb_endpoint_xfer_bulk(d)) {
 394                 dev_warn(ddev, "config %d interface %d altsetting %d "
 395                     "endpoint 0x%X is Bulk; changing to Interrupt\n",
 396                     cfgno, inum, asnum, d->bEndpointAddress);
 397                 endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
 398                 endpoint->desc.bInterval = 1;
 399                 if (usb_endpoint_maxp(&endpoint->desc) > 8)
 400                         endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
 401         }
 402
 403         /*
 404          * Validate the wMaxPacketSize field.
 405          * Some devices have isochronous endpoints in altsetting 0;
 406          * the USB-2 spec requires such endpoints to have wMaxPacketSize = 0
 407          * (see the end of section 5.6.3), so don't warn about them.
 408          */
 409         maxp = usb_endpoint_maxp(&endpoint->desc);
 410         if (maxp == 0 && !(usb_endpoint_xfer_isoc(d) && asnum == 0)) {
 411                 dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid wMaxPacketSize 0\n",
 412                     cfgno, inum, asnum, d->bEndpointAddress);
 413         }
 414
 415         /* Find the highest legal maxpacket size for this endpoint */
 416         i = 0;          /* additional transactions per microframe */
 417         switch (udev->speed) {
 418         case USB_SPEED_LOW:
 419                 maxpacket_maxes = low_speed_maxpacket_maxes;
 420                 break;
 421         case USB_SPEED_FULL:
 422                 maxpacket_maxes = full_speed_maxpacket_maxes;
 423                 break;
 424         case USB_SPEED_HIGH:
 425                 /* Bits 12..11 are allowed only for HS periodic endpoints */
 426                 if (usb_endpoint_xfer_int(d) || usb_endpoint_xfer_isoc(d)) {
 427                         i = maxp & (BIT(12) | BIT(11));
 428                         maxp &= ~i;
 429                 }
 430                 fallthrough;
 431         default:
 432                 maxpacket_maxes = high_speed_maxpacket_maxes;
 433                 break;
 434         case USB_SPEED_SUPER:
 435         case USB_SPEED_SUPER_PLUS:
 436                 maxpacket_maxes = super_speed_maxpacket_maxes;
 437                 break;
 438         }
 439         j = maxpacket_maxes[usb_endpoint_type(&endpoint->desc)];
 440
 441         if (maxp > j) {
 442                 dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid maxpacket %d, setting to %d\n",
 443                     cfgno, inum, asnum, d->bEndpointAddress, maxp, j);
 444                 maxp = j;
 445                 endpoint->desc.wMaxPacketSize = cpu_to_le16(i | maxp);
 446         }
 447
 448         /*
 449          * Some buggy high speed devices have bulk endpoints using
 450          * maxpacket sizes other than 512.  High speed HCDs may not
 451          * be able to handle that particular bug, so let's warn...
 452          */
 453         if (udev->speed == USB_SPEED_HIGH && usb_endpoint_xfer_bulk(d)) {
 454                 if (maxp != 512)
 455                         dev_warn(ddev, "config %d interface %d altsetting %d "
 456                                 "bulk endpoint 0x%X has invalid maxpacket %d\n",
 457                                 cfgno, inum, asnum, d->bEndpointAddress,
 458                                 maxp);
 459         }
 460
 461         /* Parse a possible SuperSpeed endpoint companion descriptor */
 462         if (udev->speed >= USB_SPEED_SUPER)
 463                 usb_parse_ss_endpoint_companion(ddev, cfgno,
 464                                 inum, asnum, endpoint, buffer, size);
 465
 466         /* Skip over any Class Specific or Vendor Specific descriptors;
 467          * find the next endpoint or interface descriptor */
 468         endpoint->extra = buffer;
 469         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 470                         USB_DT_INTERFACE, &n);
 471         endpoint->extralen = i;
 472         retval = buffer - buffer0 + i;
 473         if (n > 0)
 474                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 475                     n, plural(n), "endpoint");
 476         return retval;
 477
 478 skip_to_next_endpoint_or_interface_descriptor:
 479         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 480             USB_DT_INTERFACE, NULL);
 481         return buffer - buffer0 + i;
 482 }
 483
 484 void usb_release_interface_cache(struct kref *ref)
 485 {
 486         struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
 487         int j;
 488
 489         for (j = 0; j < intfc->num_altsetting; j++) {
 490                 struct usb_host_interface *alt = &intfc->altsetting[j];
 491
 492                 kfree(alt->endpoint);
 493                 kfree(alt->string);
 494         }
 495         kfree(intfc);
 496 }
 497
 498 static int usb_parse_interface(struct device *ddev, int cfgno,
 499     struct usb_host_config *config, unsigned char *buffer, int size,
 500     u8 inums[], u8 nalts[])
 501 {
 502         unsigned char *buffer0 = buffer;
 503         struct usb_interface_descriptor *d;
 504         int inum, asnum;
 505         struct usb_interface_cache *intfc;
 506         struct usb_host_interface *alt;
 507         int i, n;
 508         int len, retval;
 509         int num_ep, num_ep_orig;
 510
 511         d = (struct usb_interface_descriptor *) buffer;
 512         buffer += d->bLength;
 513         size -= d->bLength;
 514
 515         if (d->bLength < USB_DT_INTERFACE_SIZE)
 516                 goto skip_to_next_interface_descriptor;
 517
 518         /* Which interface entry is this? */
 519         intfc = NULL;
 520         inum = d->bInterfaceNumber;
 521         for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 522                 if (inums[i] == inum) {
 523                         intfc = config->intf_cache[i];
 524                         break;
 525                 }
 526         }
 527         if (!intfc || intfc->num_altsetting >= nalts[i])
 528                 goto skip_to_next_interface_descriptor;
 529
 530         /* Check for duplicate altsetting entries */
 531         asnum = d->bAlternateSetting;
 532         for ((i = 0, alt = &intfc->altsetting[0]);
 533               i < intfc->num_altsetting;
 534              (++i, ++alt)) {
 535                 if (alt->desc.bAlternateSetting == asnum) {
 536                         dev_warn(ddev, "Duplicate descriptor for config %d "
 537                             "interface %d altsetting %d, skipping\n",
 538                             cfgno, inum, asnum);
 539                         goto skip_to_next_interface_descriptor;
 540                 }
 541         }
 542
 543         ++intfc->num_altsetting;
 544         memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
 545
 546         /* Skip over any Class Specific or Vendor Specific descriptors;
 547          * find the first endpoint or interface descriptor */
 548         alt->extra = buffer;
 549         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 550             USB_DT_INTERFACE, &n);
 551         alt->extralen = i;
 552         if (n > 0)
 553                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 554                     n, plural(n), "interface");
 555         buffer += i;
 556         size -= i;
 557
 558         /* Allocate space for the right(?) number of endpoints */
 559         num_ep = num_ep_orig = alt->desc.bNumEndpoints;
 560         alt->desc.bNumEndpoints = 0;            /* Use as a counter */
 561         if (num_ep > USB_MAXENDPOINTS) {
 562                 dev_warn(ddev, "too many endpoints for config %d interface %d "
 563                     "altsetting %d: %d, using maximum allowed: %d\n",
 564                     cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
 565                 num_ep = USB_MAXENDPOINTS;
 566         }
 567
 568         if (num_ep > 0) {
 569                 /* Can't allocate 0 bytes */
 570                 len = sizeof(struct usb_host_endpoint) * num_ep;
 571                 alt->endpoint = kzalloc(len, GFP_KERNEL);
 572                 if (!alt->endpoint)
 573                         return -ENOMEM;
 574         }
 575
 576         /* Parse all the endpoint descriptors */
 577         n = 0;
 578         while (size > 0) {
 579                 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
 580                      == USB_DT_INTERFACE)
 581                         break;
 582                 retval = usb_parse_endpoint(ddev, cfgno, config, inum, asnum,
 583                                 alt, num_ep, buffer, size);
 584                 if (retval < 0)
 585                         return retval;
 586                 ++n;
 587
 588                 buffer += retval;
 589                 size -= retval;
 590         }
 591
 592         if (n != num_ep_orig)
 593                 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
 594                     "endpoint descriptor%s, different from the interface "
 595                     "descriptor's value: %d\n",
 596                     cfgno, inum, asnum, n, plural(n), num_ep_orig);
 597         return buffer - buffer0;
 598
 599 skip_to_next_interface_descriptor:
 600         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 601             USB_DT_INTERFACE, NULL);
 602         return buffer - buffer0 + i;
 603 }
 604
 605 static int usb_parse_configuration(struct usb_device *dev, int cfgidx,
 606     struct usb_host_config *config, unsigned char *buffer, int size)
 607 {
 608         struct device *ddev = &dev->dev;
 609         unsigned char *buffer0 = buffer;
 610         int cfgno;
 611         int nintf, nintf_orig;
 612         int i, j, n;
 613         struct usb_interface_cache *intfc;
 614         unsigned char *buffer2;
 615         int size2;
 616         struct usb_descriptor_header *header;
 617         int retval;
 618         u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
 619         unsigned iad_num = 0;
 620
 621         memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
 622         nintf = nintf_orig = config->desc.bNumInterfaces;
 623         config->desc.bNumInterfaces = 0;        // Adjusted later
 624
 625         if (config->desc.bDescriptorType != USB_DT_CONFIG ||
 626             config->desc.bLength < USB_DT_CONFIG_SIZE ||
 627             config->desc.bLength > size) {
 628                 dev_err(ddev, "invalid descriptor for config index %d: "
 629                     "type = 0x%X, length = %d\n", cfgidx,
 630                     config->desc.bDescriptorType, config->desc.bLength);
 631                 return -EINVAL;
 632         }
 633         cfgno = config->desc.bConfigurationValue;
 634
 635         buffer += config->desc.bLength;
 636         size -= config->desc.bLength;
 637
 638         if (nintf > USB_MAXINTERFACES) {
 639                 dev_warn(ddev, "config %d has too many interfaces: %d, "
 640                     "using maximum allowed: %d\n",
 641                     cfgno, nintf, USB_MAXINTERFACES);
 642                 nintf = USB_MAXINTERFACES;
 643         }
 644
 645         /* Go through the descriptors, checking their length and counting the
 646          * number of altsettings for each interface */
 647         n = 0;
 648         for ((buffer2 = buffer, size2 = size);
 649               size2 > 0;
 650              (buffer2 += header->bLength, size2 -= header->bLength)) {
 651
 652                 if (size2 < sizeof(struct usb_descriptor_header)) {
 653                         dev_warn(ddev, "config %d descriptor has %d excess "
 654                             "byte%s, ignoring\n",
 655                             cfgno, size2, plural(size2));
 656                         break;
 657                 }
 658
 659                 header = (struct usb_descriptor_header *) buffer2;
 660                 if ((header->bLength > size2) || (header->bLength < 2)) {
 661                         dev_warn(ddev, "config %d has an invalid descriptor "
 662                             "of length %d, skipping remainder of the config\n",
 663                             cfgno, header->bLength);
 664                         break;
 665                 }
 666
 667                 if (header->bDescriptorType == USB_DT_INTERFACE) {
 668                         struct usb_interface_descriptor *d;
 669                         int inum;
 670
 671                         d = (struct usb_interface_descriptor *) header;
 672                         if (d->bLength < USB_DT_INTERFACE_SIZE) {
 673                                 dev_warn(ddev, "config %d has an invalid "
 674                                     "interface descriptor of length %d, "
 675                                     "skipping\n", cfgno, d->bLength);
 676                                 continue;
 677                         }
 678
 679                         inum = d->bInterfaceNumber;
 680
 681                         if ((dev->quirks & USB_QUIRK_HONOR_BNUMINTERFACES) &&
 682                             n >= nintf_orig) {
 683                                 dev_warn(ddev, "config %d has more interface "
 684                                     "descriptors, than it declares in "
 685                                     "bNumInterfaces, ignoring interface "
 686                                     "number: %d\n", cfgno, inum);
 687                                 continue;
 688                         }
 689
 690                         if (inum >= nintf_orig)
 691                                 dev_warn(ddev, "config %d has an invalid "
 692                                     "interface number: %d but max is %d\n",
 693                                     cfgno, inum, nintf_orig - 1);
 694
 695                         /* Have we already encountered this interface?
 696                          * Count its altsettings */
 697                         for (i = 0; i < n; ++i) {
 698                                 if (inums[i] == inum)
 699                                         break;
 700                         }
 701                         if (i < n) {
 702                                 if (nalts[i] < 255)
 703                                         ++nalts[i];
 704                         } else if (n < USB_MAXINTERFACES) {
 705                                 inums[n] = inum;
 706                                 nalts[n] = 1;
 707                                 ++n;
 708                         }
 709
 710                 } else if (header->bDescriptorType ==
 711                                 USB_DT_INTERFACE_ASSOCIATION) {
 712                         struct usb_interface_assoc_descriptor *d;
 713
 714                         d = (struct usb_interface_assoc_descriptor *)header;
 715                         if (d->bLength < USB_DT_INTERFACE_ASSOCIATION_SIZE) {
 716                                 dev_warn(ddev,
 717                                          "config %d has an invalid interface association descriptor of length %d, skipping\n",
 718                                          cfgno, d->bLength);
 719                                 continue;
 720                         }
 721
 722                         if (iad_num == USB_MAXIADS) {
 723                                 dev_warn(ddev, "found more Interface "
 724                                                "Association Descriptors "
 725                                                "than allocated for in "
 726                                                "configuration %d\n", cfgno);
 727                         } else {
 728                                 config->intf_assoc[iad_num] = d;
 729                                 iad_num++;
 730                         }
 731
 732                 } else if (header->bDescriptorType == USB_DT_DEVICE ||
 733                             header->bDescriptorType == USB_DT_CONFIG)
 734                         dev_warn(ddev, "config %d contains an unexpected "
 735                             "descriptor of type 0x%X, skipping\n",
 736                             cfgno, header->bDescriptorType);
 737
 738         }       /* for ((buffer2 = buffer, size2 = size); ...) */
 739         size = buffer2 - buffer;
 740         config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
 741
 742         if (n != nintf)
 743                 dev_warn(ddev, "config %d has %d interface%s, different from "
 744                     "the descriptor's value: %d\n",
 745                     cfgno, n, plural(n), nintf_orig);
 746         else if (n == 0)
 747                 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
 748         config->desc.bNumInterfaces = nintf = n;
 749
 750         /* Check for missing interface numbers */
 751         for (i = 0; i < nintf; ++i) {
 752                 for (j = 0; j < nintf; ++j) {
 753                         if (inums[j] == i)
 754                                 break;
 755                 }
 756                 if (j >= nintf)
 757                         dev_warn(ddev, "config %d has no interface number "
 758                             "%d\n", cfgno, i);
 759         }
 760
 761         /* Allocate the usb_interface_caches and altsetting arrays */
 762         for (i = 0; i < nintf; ++i) {
 763                 j = nalts[i];
 764                 if (j > USB_MAXALTSETTING) {
 765                         dev_warn(ddev, "too many alternate settings for "
 766                             "config %d interface %d: %d, "
 767                             "using maximum allowed: %d\n",
 768                             cfgno, inums[i], j, USB_MAXALTSETTING);
 769                         nalts[i] = j = USB_MAXALTSETTING;
 770                 }
 771
 772                 intfc = kzalloc(struct_size(intfc, altsetting, j), GFP_KERNEL);
 773                 config->intf_cache[i] = intfc;
 774                 if (!intfc)
 775                         return -ENOMEM;
 776                 kref_init(&intfc->ref);
 777         }
 778
 779         /* FIXME: parse the BOS descriptor */
 780
 781         /* Skip over any Class Specific or Vendor Specific descriptors;
 782          * find the first interface descriptor */
 783         config->extra = buffer;
 784         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 785             USB_DT_INTERFACE, &n);
 786         config->extralen = i;
 787         if (n > 0)
 788                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 789                     n, plural(n), "configuration");
 790         buffer += i;
 791         size -= i;
 792
 793         /* Parse all the interface/altsetting descriptors */
 794         while (size > 0) {
 795                 retval = usb_parse_interface(ddev, cfgno, config,
 796                     buffer, size, inums, nalts);
 797                 if (retval < 0)
 798                         return retval;
 799
 800                 buffer += retval;
 801                 size -= retval;
 802         }
 803
 804         /* Check for missing altsettings */
 805         for (i = 0; i < nintf; ++i) {
 806                 intfc = config->intf_cache[i];
 807                 for (j = 0; j < intfc->num_altsetting; ++j) {
 808                         for (n = 0; n < intfc->num_altsetting; ++n) {
 809                                 if (intfc->altsetting[n].desc.
 810                                     bAlternateSetting == j)
 811                                         break;
 812                         }
 813                         if (n >= intfc->num_altsetting)
 814                                 dev_warn(ddev, "config %d interface %d has no "
 815                                     "altsetting %d\n", cfgno, inums[i], j);
 816                 }
 817         }
 818
 819         return 0;
 820 }
 821
 822 /* hub-only!! ... and only exported for reset/reinit path.
 823  * otherwise used internally on disconnect/destroy path
 824  */
 825 void usb_destroy_configuration(struct usb_device *dev)
 826 {
 827         int c, i;
 828
 829         if (!dev->config)
 830                 return;
 831
 832         if (dev->rawdescriptors) {
 833                 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
 834                         kfree(dev->rawdescriptors[i]);
 835
 836                 kfree(dev->rawdescriptors);
 837                 dev->rawdescriptors = NULL;
 838         }
 839
 840         for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
 841                 struct usb_host_config *cf = &dev->config[c];
 842
 843                 kfree(cf->string);
 844                 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
 845                         if (cf->intf_cache[i])
 846                                 kref_put(&cf->intf_cache[i]->ref,
 847                                           usb_release_interface_cache);
 848                 }
 849         }
 850         kfree(dev->config);
 851         dev->config = NULL;
 852 }
 853
 854
 855 /*
 856  * Get the USB config descriptors, cache and parse'em
 857  *
 858  * hub-only!! ... and only in reset path, or usb_new_device()
 859  * (used by real hubs and virtual root hubs)
 860  */
 861 int usb_get_configuration(struct usb_device *dev)
 862 {
 863         struct device *ddev = &dev->dev;
 864         int ncfg = dev->descriptor.bNumConfigurations;
 865         unsigned int cfgno, length;
 866         unsigned char *bigbuffer;
 867         struct usb_config_descriptor *desc;
 868         int result;
 869
 870         if (ncfg > USB_MAXCONFIG) {
 871                 dev_warn(ddev, "too many configurations: %d, "
 872                     "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
 873                 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
 874         }
 875
 876         if (ncfg < 1) {
 877                 dev_err(ddev, "no configurations\n");
 878                 return -EINVAL;
 879         }
 880
 881         length = ncfg * sizeof(struct usb_host_config);
 882         dev->config = kzalloc(length, GFP_KERNEL);
 883         if (!dev->config)
 884                 return -ENOMEM;
 885
 886         length = ncfg * sizeof(char *);
 887         dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
 888         if (!dev->rawdescriptors)
 889                 return -ENOMEM;
 890
 891         desc = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
 892         if (!desc)
 893                 return -ENOMEM;
 894
 895         for (cfgno = 0; cfgno < ncfg; cfgno++) {
 896                 /* We grab just the first descriptor so we know how long
 897                  * the whole configuration is */
 898                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 899                     desc, USB_DT_CONFIG_SIZE);
 900                 if (result < 0) {
 901                         dev_err(ddev, "unable to read config index %d "
 902                             "descriptor/%s: %d\n", cfgno, "start", result);
 903                         if (result != -EPIPE)
 904                                 goto err;
 905                         dev_err(ddev, "chopping to %d config(s)\n", cfgno);
 906                         dev->descriptor.bNumConfigurations = cfgno;
 907                         break;
 908                 } else if (result < 4) {
 909                         dev_err(ddev, "config index %d descriptor too short "
 910                             "(expected %i, got %i)\n", cfgno,
 911                             USB_DT_CONFIG_SIZE, result);
 912                         result = -EINVAL;
 913                         goto err;
 914                 }
 915                 length = max((int) le16_to_cpu(desc->wTotalLength),
 916                     USB_DT_CONFIG_SIZE);
 917
 918                 /* Now that we know the length, get the whole thing */
 919                 bigbuffer = kmalloc(length, GFP_KERNEL);
 920                 if (!bigbuffer) {
 921                         result = -ENOMEM;
 922                         goto err;
 923                 }
 924
 925                 if (dev->quirks & USB_QUIRK_DELAY_INIT)
 926                         msleep(200);
 927
 928                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 929                     bigbuffer, length);
 930                 if (result < 0) {
 931                         dev_err(ddev, "unable to read config index %d "
 932                             "descriptor/%s\n", cfgno, "all");
 933                         kfree(bigbuffer);
 934                         goto err;
 935                 }
 936                 if (result < length) {
 937                         dev_warn(ddev, "config index %d descriptor too short "
 938                             "(expected %i, got %i)\n", cfgno, length, result);
 939                         length = result;
 940                 }
 941
 942                 dev->rawdescriptors[cfgno] = bigbuffer;
 943
 944                 result = usb_parse_configuration(dev, cfgno,
 945                     &dev->config[cfgno], bigbuffer, length);
 946                 if (result < 0) {
 947                         ++cfgno;
 948                         goto err;
 949                 }
 950         }
 951
 952 err:
 953         kfree(desc);
 954         dev->descriptor.bNumConfigurations = cfgno;
 955
 956         return result;
 957 }
 958
 959 void usb_release_bos_descriptor(struct usb_device *dev)
 960 {
 961         if (dev->bos) {
 962                 kfree(dev->bos->desc);
 963                 kfree(dev->bos);
 964                 dev->bos = NULL;
 965         }
 966 }
 967
 968 static const __u8 bos_desc_len[256] = {
 969         [USB_CAP_TYPE_WIRELESS_USB] = USB_DT_USB_WIRELESS_CAP_SIZE,
 970         [USB_CAP_TYPE_EXT]          = USB_DT_USB_EXT_CAP_SIZE,
 971         [USB_SS_CAP_TYPE]           = USB_DT_USB_SS_CAP_SIZE,
 972         [USB_SSP_CAP_TYPE]          = USB_DT_USB_SSP_CAP_SIZE(1),
 973         [CONTAINER_ID_TYPE]         = USB_DT_USB_SS_CONTN_ID_SIZE,
 974         [USB_PTM_CAP_TYPE]          = USB_DT_USB_PTM_ID_SIZE,
 975 };
 976
 977 /* Get BOS descriptor set */
 978 int usb_get_bos_descriptor(struct usb_device *dev)
 979 {
 980         struct device *ddev = &dev->dev;
 981         struct usb_bos_descriptor *bos;
 982         struct usb_dev_cap_header *cap;
 983         struct usb_ssp_cap_descriptor *ssp_cap;
 984         unsigned char *buffer, *buffer0;
 985         int length, total_len, num, i, ssac;
 986         __u8 cap_type;
 987         int ret;
 988
 989         bos = kzalloc(sizeof(struct usb_bos_descriptor), GFP_KERNEL);
 990         if (!bos)
 991                 return -ENOMEM;
 992
 993         /* Get BOS descriptor */
 994         ret = usb_get_descriptor(dev, USB_DT_BOS, 0, bos, USB_DT_BOS_SIZE);
 995         if (ret < USB_DT_BOS_SIZE || bos->bLength < USB_DT_BOS_SIZE) {
 996                 dev_err(ddev, "unable to get BOS descriptor or descriptor too short\n");
 997                 if (ret >= 0)
 998                         ret = -ENOMSG;
 999                 kfree(bos);
1000                 return ret;
1001         }
1002
1003         length = bos->bLength;
1004         total_len = le16_to_cpu(bos->wTotalLength);
1005         num = bos->bNumDeviceCaps;
1006         kfree(bos);
1007         if (total_len < length)
1008                 return -EINVAL;
1009
1010         dev->bos = kzalloc(sizeof(struct usb_host_bos), GFP_KERNEL);
1011         if (!dev->bos)
1012                 return -ENOMEM;
1013
1014         /* Now let's get the whole BOS descriptor set */
1015         buffer = kzalloc(total_len, GFP_KERNEL);
1016         if (!buffer) {
1017                 ret = -ENOMEM;
1018                 goto err;
1019         }
1020         dev->bos->desc = (struct usb_bos_descriptor *)buffer;
1021
1022         ret = usb_get_descriptor(dev, USB_DT_BOS, 0, buffer, total_len);
1023         if (ret < total_len) {
1024                 dev_err(ddev, "unable to get BOS descriptor set\n");
1025                 if (ret >= 0)
1026                         ret = -ENOMSG;
1027                 goto err;
1028         }
1029
1030         buffer0 = buffer;
1031         total_len -= length;
1032         buffer += length;
1033
1034         for (i = 0; i < num; i++) {
1035                 cap = (struct usb_dev_cap_header *)buffer;
1036
1037                 if (total_len < sizeof(*cap) || total_len < cap->bLength) {
1038                         dev->bos->desc->bNumDeviceCaps = i;
1039                         break;
1040                 }
1041                 cap_type = cap->bDevCapabilityType;
1042                 length = cap->bLength;
1043                 if (bos_desc_len[cap_type] && length < bos_desc_len[cap_type]) {
1044                         dev->bos->desc->bNumDeviceCaps = i;
1045                         break;
1046                 }
1047
1048                 if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) {
1049                         dev_warn(ddev, "descriptor type invalid, skip\n");
1050                         continue;
1051                 }
1052
1053                 switch (cap_type) {
1054                 case USB_CAP_TYPE_WIRELESS_USB:
1055                         /* Wireless USB cap descriptor is handled by wusb */
1056                         break;
1057                 case USB_CAP_TYPE_EXT:
1058                         dev->bos->ext_cap =
1059                                 (struct usb_ext_cap_descriptor *)buffer;
1060                         break;
1061                 case USB_SS_CAP_TYPE:
1062                         dev->bos->ss_cap =
1063                                 (struct usb_ss_cap_descriptor *)buffer;
1064                         break;
1065                 case USB_SSP_CAP_TYPE:
1066                         ssp_cap = (struct usb_ssp_cap_descriptor *)buffer;
1067                         ssac = (le32_to_cpu(ssp_cap->bmAttributes) &
1068                                 USB_SSP_SUBLINK_SPEED_ATTRIBS);
1069                         if (length >= USB_DT_USB_SSP_CAP_SIZE(ssac))
1070                                 dev->bos->ssp_cap = ssp_cap;
1071                         break;
1072                 case CONTAINER_ID_TYPE:
1073                         dev->bos->ss_id =
1074                                 (struct usb_ss_container_id_descriptor *)buffer;
1075                         break;
1076                 case USB_PTM_CAP_TYPE:
1077                         dev->bos->ptm_cap =
1078                                 (struct usb_ptm_cap_descriptor *)buffer;
1079                         break;
1080                 default:
1081                         break;
1082                 }
1083
1084                 total_len -= length;
1085                 buffer += length;
1086         }
1087         dev->bos->desc->wTotalLength = cpu_to_le16(buffer - buffer0);
1088
1089         return 0;
1090
1091 err:
1092         usb_release_bos_descriptor(dev);
1093         return ret;
1094 }