drivers/usb/core/config.c

   1 /*
   2  * Released under the GPLv2 only.
   3  * SPDX-License-Identifier: GPL-2.0
   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         [USB_ENDPOINT_XFER_BULK] = 512,
 195         [USB_ENDPOINT_XFER_INT] = 1024,
 196 };
 197 static const unsigned short super_speed_maxpacket_maxes[4] = {
 198         [USB_ENDPOINT_XFER_CONTROL] = 512,
 199         [USB_ENDPOINT_XFER_ISOC] = 1024,
 200         [USB_ENDPOINT_XFER_BULK] = 1024,
 201         [USB_ENDPOINT_XFER_INT] = 1024,
 202 };
 203
 204 static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
 205     int asnum, struct usb_host_interface *ifp, int num_ep,
 206     unsigned char *buffer, int size)
 207 {
 208         unsigned char *buffer0 = buffer;
 209         struct usb_endpoint_descriptor *d;
 210         struct usb_host_endpoint *endpoint;
 211         int n, i, j, retval;
 212         unsigned int maxp;
 213         const unsigned short *maxpacket_maxes;
 214
 215         d = (struct usb_endpoint_descriptor *) buffer;
 216         buffer += d->bLength;
 217         size -= d->bLength;
 218
 219         if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
 220                 n = USB_DT_ENDPOINT_AUDIO_SIZE;
 221         else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
 222                 n = USB_DT_ENDPOINT_SIZE;
 223         else {
 224                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 225                     "invalid endpoint descriptor of length %d, skipping\n",
 226                     cfgno, inum, asnum, d->bLength);
 227                 goto skip_to_next_endpoint_or_interface_descriptor;
 228         }
 229
 230         i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
 231         if (i >= 16 || i == 0) {
 232                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 233                     "invalid endpoint with address 0x%X, skipping\n",
 234                     cfgno, inum, asnum, d->bEndpointAddress);
 235                 goto skip_to_next_endpoint_or_interface_descriptor;
 236         }
 237
 238         /* Only store as many endpoints as we have room for */
 239         if (ifp->desc.bNumEndpoints >= num_ep)
 240                 goto skip_to_next_endpoint_or_interface_descriptor;
 241
 242         /* Check for duplicate endpoint addresses */
 243         for (i = 0; i < ifp->desc.bNumEndpoints; ++i) {
 244                 if (ifp->endpoint[i].desc.bEndpointAddress ==
 245                     d->bEndpointAddress) {
 246                         dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n",
 247                             cfgno, inum, asnum, d->bEndpointAddress);
 248                         goto skip_to_next_endpoint_or_interface_descriptor;
 249                 }
 250         }
 251
 252         endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
 253         ++ifp->desc.bNumEndpoints;
 254
 255         memcpy(&endpoint->desc, d, n);
 256         INIT_LIST_HEAD(&endpoint->urb_list);
 257
 258         /*
 259          * Fix up bInterval values outside the legal range.
 260          * Use 10 or 8 ms if no proper value can be guessed.
 261          */
 262         i = 0;          /* i = min, j = max, n = default */
 263         j = 255;
 264         if (usb_endpoint_xfer_int(d)) {
 265                 i = 1;
 266                 switch (to_usb_device(ddev)->speed) {
 267                 case USB_SPEED_SUPER_PLUS:
 268                 case USB_SPEED_SUPER:
 269                 case USB_SPEED_HIGH:
 270                         /*
 271                          * Many device manufacturers are using full-speed
 272                          * bInterval values in high-speed interrupt endpoint
 273                          * descriptors. Try to fix those and fall back to an
 274                          * 8-ms default value otherwise.
 275                          */
 276                         n = fls(d->bInterval*8);
 277                         if (n == 0)
 278                                 n = 7;  /* 8 ms = 2^(7-1) uframes */
 279                         j = 16;
 280
 281                         /*
 282                          * Adjust bInterval for quirked devices.
 283                          * This quirk fixes bIntervals reported in
 284                          * linear microframes.
 285                          */
 286                         if (to_usb_device(ddev)->quirks &
 287                                 USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL) {
 288                                 n = clamp(fls(d->bInterval), i, j);
 289                                 i = j = n;
 290                         }
 291                         break;
 292                 default:                /* USB_SPEED_FULL or _LOW */
 293                         /*
 294                          * For low-speed, 10 ms is the official minimum.
 295                          * But some "overclocked" devices might want faster
 296                          * polling so we'll allow it.
 297                          */
 298                         n = 10;
 299                         break;
 300                 }
 301         } else if (usb_endpoint_xfer_isoc(d)) {
 302                 i = 1;
 303                 j = 16;
 304                 switch (to_usb_device(ddev)->speed) {
 305                 case USB_SPEED_HIGH:
 306                         n = 7;          /* 8 ms = 2^(7-1) uframes */
 307                         break;
 308                 default:                /* USB_SPEED_FULL */
 309                         n = 4;          /* 8 ms = 2^(4-1) frames */
 310                         break;
 311                 }
 312         }
 313         if (d->bInterval < i || d->bInterval > j) {
 314                 dev_warn(ddev, "config %d interface %d altsetting %d "
 315                     "endpoint 0x%X has an invalid bInterval %d, "
 316                     "changing to %d\n",
 317                     cfgno, inum, asnum,
 318                     d->bEndpointAddress, d->bInterval, n);
 319                 endpoint->desc.bInterval = n;
 320         }
 321
 322         /* Some buggy low-speed devices have Bulk endpoints, which is
 323          * explicitly forbidden by the USB spec.  In an attempt to make
 324          * them usable, we will try treating them as Interrupt endpoints.
 325          */
 326         if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
 327                         usb_endpoint_xfer_bulk(d)) {
 328                 dev_warn(ddev, "config %d interface %d altsetting %d "
 329                     "endpoint 0x%X is Bulk; changing to Interrupt\n",
 330                     cfgno, inum, asnum, d->bEndpointAddress);
 331                 endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
 332                 endpoint->desc.bInterval = 1;
 333                 if (usb_endpoint_maxp(&endpoint->desc) > 8)
 334                         endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
 335         }
 336
 337         /* Validate the wMaxPacketSize field */
 338         maxp = usb_endpoint_maxp(&endpoint->desc);
 339
 340         /* Find the highest legal maxpacket size for this endpoint */
 341         i = 0;          /* additional transactions per microframe */
 342         switch (to_usb_device(ddev)->speed) {
 343         case USB_SPEED_LOW:
 344                 maxpacket_maxes = low_speed_maxpacket_maxes;
 345                 break;
 346         case USB_SPEED_FULL:
 347                 maxpacket_maxes = full_speed_maxpacket_maxes;
 348                 break;
 349         case USB_SPEED_HIGH:
 350                 /* Bits 12..11 are allowed only for HS periodic endpoints */
 351                 if (usb_endpoint_xfer_int(d) || usb_endpoint_xfer_isoc(d)) {
 352                         i = maxp & (BIT(12) | BIT(11));
 353                         maxp &= ~i;
 354                 }
 355                 /* fallthrough */
 356         default:
 357                 maxpacket_maxes = high_speed_maxpacket_maxes;
 358                 break;
 359         case USB_SPEED_SUPER:
 360         case USB_SPEED_SUPER_PLUS:
 361                 maxpacket_maxes = super_speed_maxpacket_maxes;
 362                 break;
 363         }
 364         j = maxpacket_maxes[usb_endpoint_type(&endpoint->desc)];
 365
 366         if (maxp > j) {
 367                 dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid maxpacket %d, setting to %d\n",
 368                     cfgno, inum, asnum, d->bEndpointAddress, maxp, j);
 369                 maxp = j;
 370                 endpoint->desc.wMaxPacketSize = cpu_to_le16(i | maxp);
 371         }
 372
 373         /*
 374          * Some buggy high speed devices have bulk endpoints using
 375          * maxpacket sizes other than 512.  High speed HCDs may not
 376          * be able to handle that particular bug, so let's warn...
 377          */
 378         if (to_usb_device(ddev)->speed == USB_SPEED_HIGH
 379                         && usb_endpoint_xfer_bulk(d)) {
 380                 if (maxp != 512)
 381                         dev_warn(ddev, "config %d interface %d altsetting %d "
 382                                 "bulk endpoint 0x%X has invalid maxpacket %d\n",
 383                                 cfgno, inum, asnum, d->bEndpointAddress,
 384                                 maxp);
 385         }
 386
 387         /* Parse a possible SuperSpeed endpoint companion descriptor */
 388         if (to_usb_device(ddev)->speed >= USB_SPEED_SUPER)
 389                 usb_parse_ss_endpoint_companion(ddev, cfgno,
 390                                 inum, asnum, endpoint, buffer, size);
 391
 392         /* Skip over any Class Specific or Vendor Specific descriptors;
 393          * find the next endpoint or interface descriptor */
 394         endpoint->extra = buffer;
 395         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 396                         USB_DT_INTERFACE, &n);
 397         endpoint->extralen = i;
 398         retval = buffer - buffer0 + i;
 399         if (n > 0)
 400                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 401                     n, plural(n), "endpoint");
 402         return retval;
 403
 404 skip_to_next_endpoint_or_interface_descriptor:
 405         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 406             USB_DT_INTERFACE, NULL);
 407         return buffer - buffer0 + i;
 408 }
 409
 410 void usb_release_interface_cache(struct kref *ref)
 411 {
 412         struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
 413         int j;
 414
 415         for (j = 0; j < intfc->num_altsetting; j++) {
 416                 struct usb_host_interface *alt = &intfc->altsetting[j];
 417
 418                 kfree(alt->endpoint);
 419                 kfree(alt->string);
 420         }
 421         kfree(intfc);
 422 }
 423
 424 static int usb_parse_interface(struct device *ddev, int cfgno,
 425     struct usb_host_config *config, unsigned char *buffer, int size,
 426     u8 inums[], u8 nalts[])
 427 {
 428         unsigned char *buffer0 = buffer;
 429         struct usb_interface_descriptor *d;
 430         int inum, asnum;
 431         struct usb_interface_cache *intfc;
 432         struct usb_host_interface *alt;
 433         int i, n;
 434         int len, retval;
 435         int num_ep, num_ep_orig;
 436
 437         d = (struct usb_interface_descriptor *) buffer;
 438         buffer += d->bLength;
 439         size -= d->bLength;
 440
 441         if (d->bLength < USB_DT_INTERFACE_SIZE)
 442                 goto skip_to_next_interface_descriptor;
 443
 444         /* Which interface entry is this? */
 445         intfc = NULL;
 446         inum = d->bInterfaceNumber;
 447         for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 448                 if (inums[i] == inum) {
 449                         intfc = config->intf_cache[i];
 450                         break;
 451                 }
 452         }
 453         if (!intfc || intfc->num_altsetting >= nalts[i])
 454                 goto skip_to_next_interface_descriptor;
 455
 456         /* Check for duplicate altsetting entries */
 457         asnum = d->bAlternateSetting;
 458         for ((i = 0, alt = &intfc->altsetting[0]);
 459               i < intfc->num_altsetting;
 460              (++i, ++alt)) {
 461                 if (alt->desc.bAlternateSetting == asnum) {
 462                         dev_warn(ddev, "Duplicate descriptor for config %d "
 463                             "interface %d altsetting %d, skipping\n",
 464                             cfgno, inum, asnum);
 465                         goto skip_to_next_interface_descriptor;
 466                 }
 467         }
 468
 469         ++intfc->num_altsetting;
 470         memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
 471
 472         /* Skip over any Class Specific or Vendor Specific descriptors;
 473          * find the first endpoint or interface descriptor */
 474         alt->extra = buffer;
 475         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 476             USB_DT_INTERFACE, &n);
 477         alt->extralen = i;
 478         if (n > 0)
 479                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 480                     n, plural(n), "interface");
 481         buffer += i;
 482         size -= i;
 483
 484         /* Allocate space for the right(?) number of endpoints */
 485         num_ep = num_ep_orig = alt->desc.bNumEndpoints;
 486         alt->desc.bNumEndpoints = 0;            /* Use as a counter */
 487         if (num_ep > USB_MAXENDPOINTS) {
 488                 dev_warn(ddev, "too many endpoints for config %d interface %d "
 489                     "altsetting %d: %d, using maximum allowed: %d\n",
 490                     cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
 491                 num_ep = USB_MAXENDPOINTS;
 492         }
 493
 494         if (num_ep > 0) {
 495                 /* Can't allocate 0 bytes */
 496                 len = sizeof(struct usb_host_endpoint) * num_ep;
 497                 alt->endpoint = kzalloc(len, GFP_KERNEL);
 498                 if (!alt->endpoint)
 499                         return -ENOMEM;
 500         }
 501
 502         /* Parse all the endpoint descriptors */
 503         n = 0;
 504         while (size > 0) {
 505                 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
 506                      == USB_DT_INTERFACE)
 507                         break;
 508                 retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
 509                     num_ep, buffer, size);
 510                 if (retval < 0)
 511                         return retval;
 512                 ++n;
 513
 514                 buffer += retval;
 515                 size -= retval;
 516         }
 517
 518         if (n != num_ep_orig)
 519                 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
 520                     "endpoint descriptor%s, different from the interface "
 521                     "descriptor's value: %d\n",
 522                     cfgno, inum, asnum, n, plural(n), num_ep_orig);
 523         return buffer - buffer0;
 524
 525 skip_to_next_interface_descriptor:
 526         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 527             USB_DT_INTERFACE, NULL);
 528         return buffer - buffer0 + i;
 529 }
 530
 531 static int usb_parse_configuration(struct usb_device *dev, int cfgidx,
 532     struct usb_host_config *config, unsigned char *buffer, int size)
 533 {
 534         struct device *ddev = &dev->dev;
 535         unsigned char *buffer0 = buffer;
 536         int cfgno;
 537         int nintf, nintf_orig;
 538         int i, j, n;
 539         struct usb_interface_cache *intfc;
 540         unsigned char *buffer2;
 541         int size2;
 542         struct usb_descriptor_header *header;
 543         int len, retval;
 544         u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
 545         unsigned iad_num = 0;
 546
 547         memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
 548         if (config->desc.bDescriptorType != USB_DT_CONFIG ||
 549             config->desc.bLength < USB_DT_CONFIG_SIZE ||
 550             config->desc.bLength > size) {
 551                 dev_err(ddev, "invalid descriptor for config index %d: "
 552                     "type = 0x%X, length = %d\n", cfgidx,
 553                     config->desc.bDescriptorType, config->desc.bLength);
 554                 return -EINVAL;
 555         }
 556         cfgno = config->desc.bConfigurationValue;
 557
 558         buffer += config->desc.bLength;
 559         size -= config->desc.bLength;
 560
 561         nintf = nintf_orig = config->desc.bNumInterfaces;
 562         if (nintf > USB_MAXINTERFACES) {
 563                 dev_warn(ddev, "config %d has too many interfaces: %d, "
 564                     "using maximum allowed: %d\n",
 565                     cfgno, nintf, USB_MAXINTERFACES);
 566                 nintf = USB_MAXINTERFACES;
 567         }
 568
 569         /* Go through the descriptors, checking their length and counting the
 570          * number of altsettings for each interface */
 571         n = 0;
 572         for ((buffer2 = buffer, size2 = size);
 573               size2 > 0;
 574              (buffer2 += header->bLength, size2 -= header->bLength)) {
 575
 576                 if (size2 < sizeof(struct usb_descriptor_header)) {
 577                         dev_warn(ddev, "config %d descriptor has %d excess "
 578                             "byte%s, ignoring\n",
 579                             cfgno, size2, plural(size2));
 580                         break;
 581                 }
 582
 583                 header = (struct usb_descriptor_header *) buffer2;
 584                 if ((header->bLength > size2) || (header->bLength < 2)) {
 585                         dev_warn(ddev, "config %d has an invalid descriptor "
 586                             "of length %d, skipping remainder of the config\n",
 587                             cfgno, header->bLength);
 588                         break;
 589                 }
 590
 591                 if (header->bDescriptorType == USB_DT_INTERFACE) {
 592                         struct usb_interface_descriptor *d;
 593                         int inum;
 594
 595                         d = (struct usb_interface_descriptor *) header;
 596                         if (d->bLength < USB_DT_INTERFACE_SIZE) {
 597                                 dev_warn(ddev, "config %d has an invalid "
 598                                     "interface descriptor of length %d, "
 599                                     "skipping\n", cfgno, d->bLength);
 600                                 continue;
 601                         }
 602
 603                         inum = d->bInterfaceNumber;
 604
 605                         if ((dev->quirks & USB_QUIRK_HONOR_BNUMINTERFACES) &&
 606                             n >= nintf_orig) {
 607                                 dev_warn(ddev, "config %d has more interface "
 608                                     "descriptors, than it declares in "
 609                                     "bNumInterfaces, ignoring interface "
 610                                     "number: %d\n", cfgno, inum);
 611                                 continue;
 612                         }
 613
 614                         if (inum >= nintf_orig)
 615                                 dev_warn(ddev, "config %d has an invalid "
 616                                     "interface number: %d but max is %d\n",
 617                                     cfgno, inum, nintf_orig - 1);
 618
 619                         /* Have we already encountered this interface?
 620                          * Count its altsettings */
 621                         for (i = 0; i < n; ++i) {
 622                                 if (inums[i] == inum)
 623                                         break;
 624                         }
 625                         if (i < n) {
 626                                 if (nalts[i] < 255)
 627                                         ++nalts[i];
 628                         } else if (n < USB_MAXINTERFACES) {
 629                                 inums[n] = inum;
 630                                 nalts[n] = 1;
 631                                 ++n;
 632                         }
 633
 634                 } else if (header->bDescriptorType ==
 635                                 USB_DT_INTERFACE_ASSOCIATION) {
 636                         if (iad_num == USB_MAXIADS) {
 637                                 dev_warn(ddev, "found more Interface "
 638                                                "Association Descriptors "
 639                                                "than allocated for in "
 640                                                "configuration %d\n", cfgno);
 641                         } else {
 642                                 config->intf_assoc[iad_num] =
 643                                         (struct usb_interface_assoc_descriptor
 644                                         *)header;
 645                                 iad_num++;
 646                         }
 647
 648                 } else if (header->bDescriptorType == USB_DT_DEVICE ||
 649                             header->bDescriptorType == USB_DT_CONFIG)
 650                         dev_warn(ddev, "config %d contains an unexpected "
 651                             "descriptor of type 0x%X, skipping\n",
 652                             cfgno, header->bDescriptorType);
 653
 654         }       /* for ((buffer2 = buffer, size2 = size); ...) */
 655         size = buffer2 - buffer;
 656         config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
 657
 658         if (n != nintf)
 659                 dev_warn(ddev, "config %d has %d interface%s, different from "
 660                     "the descriptor's value: %d\n",
 661                     cfgno, n, plural(n), nintf_orig);
 662         else if (n == 0)
 663                 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
 664         config->desc.bNumInterfaces = nintf = n;
 665
 666         /* Check for missing interface numbers */
 667         for (i = 0; i < nintf; ++i) {
 668                 for (j = 0; j < nintf; ++j) {
 669                         if (inums[j] == i)
 670                                 break;
 671                 }
 672                 if (j >= nintf)
 673                         dev_warn(ddev, "config %d has no interface number "
 674                             "%d\n", cfgno, i);
 675         }
 676
 677         /* Allocate the usb_interface_caches and altsetting arrays */
 678         for (i = 0; i < nintf; ++i) {
 679                 j = nalts[i];
 680                 if (j > USB_MAXALTSETTING) {
 681                         dev_warn(ddev, "too many alternate settings for "
 682                             "config %d interface %d: %d, "
 683                             "using maximum allowed: %d\n",
 684                             cfgno, inums[i], j, USB_MAXALTSETTING);
 685                         nalts[i] = j = USB_MAXALTSETTING;
 686                 }
 687
 688                 len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
 689                 config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
 690                 if (!intfc)
 691                         return -ENOMEM;
 692                 kref_init(&intfc->ref);
 693         }
 694
 695         /* FIXME: parse the BOS descriptor */
 696
 697         /* Skip over any Class Specific or Vendor Specific descriptors;
 698          * find the first interface descriptor */
 699         config->extra = buffer;
 700         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 701             USB_DT_INTERFACE, &n);
 702         config->extralen = i;
 703         if (n > 0)
 704                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 705                     n, plural(n), "configuration");
 706         buffer += i;
 707         size -= i;
 708
 709         /* Parse all the interface/altsetting descriptors */
 710         while (size > 0) {
 711                 retval = usb_parse_interface(ddev, cfgno, config,
 712                     buffer, size, inums, nalts);
 713                 if (retval < 0)
 714                         return retval;
 715
 716                 buffer += retval;
 717                 size -= retval;
 718         }
 719
 720         /* Check for missing altsettings */
 721         for (i = 0; i < nintf; ++i) {
 722                 intfc = config->intf_cache[i];
 723                 for (j = 0; j < intfc->num_altsetting; ++j) {
 724                         for (n = 0; n < intfc->num_altsetting; ++n) {
 725                                 if (intfc->altsetting[n].desc.
 726                                     bAlternateSetting == j)
 727                                         break;
 728                         }
 729                         if (n >= intfc->num_altsetting)
 730                                 dev_warn(ddev, "config %d interface %d has no "
 731                                     "altsetting %d\n", cfgno, inums[i], j);
 732                 }
 733         }
 734
 735         return 0;
 736 }
 737
 738 /* hub-only!! ... and only exported for reset/reinit path.
 739  * otherwise used internally on disconnect/destroy path
 740  */
 741 void usb_destroy_configuration(struct usb_device *dev)
 742 {
 743         int c, i;
 744
 745         if (!dev->config)
 746                 return;
 747
 748         if (dev->rawdescriptors) {
 749                 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
 750                         kfree(dev->rawdescriptors[i]);
 751
 752                 kfree(dev->rawdescriptors);
 753                 dev->rawdescriptors = NULL;
 754         }
 755
 756         for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
 757                 struct usb_host_config *cf = &dev->config[c];
 758
 759                 kfree(cf->string);
 760                 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
 761                         if (cf->intf_cache[i])
 762                                 kref_put(&cf->intf_cache[i]->ref,
 763                                           usb_release_interface_cache);
 764                 }
 765         }
 766         kfree(dev->config);
 767         dev->config = NULL;
 768 }
 769
 770
 771 /*
 772  * Get the USB config descriptors, cache and parse'em
 773  *
 774  * hub-only!! ... and only in reset path, or usb_new_device()
 775  * (used by real hubs and virtual root hubs)
 776  */
 777 int usb_get_configuration(struct usb_device *dev)
 778 {
 779         struct device *ddev = &dev->dev;
 780         int ncfg = dev->descriptor.bNumConfigurations;
 781         int result = 0;
 782         unsigned int cfgno, length;
 783         unsigned char *bigbuffer;
 784         struct usb_config_descriptor *desc;
 785
 786         cfgno = 0;
 787         result = -ENOMEM;
 788         if (ncfg > USB_MAXCONFIG) {
 789                 dev_warn(ddev, "too many configurations: %d, "
 790                     "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
 791                 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
 792         }
 793
 794         if (ncfg < 1) {
 795                 dev_err(ddev, "no configurations\n");
 796                 return -EINVAL;
 797         }
 798
 799         length = ncfg * sizeof(struct usb_host_config);
 800         dev->config = kzalloc(length, GFP_KERNEL);
 801         if (!dev->config)
 802                 goto err2;
 803
 804         length = ncfg * sizeof(char *);
 805         dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
 806         if (!dev->rawdescriptors)
 807                 goto err2;
 808
 809         desc = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
 810         if (!desc)
 811                 goto err2;
 812
 813         result = 0;
 814         for (; cfgno < ncfg; cfgno++) {
 815                 /* We grab just the first descriptor so we know how long
 816                  * the whole configuration is */
 817                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 818                     desc, USB_DT_CONFIG_SIZE);
 819                 if (result < 0) {
 820                         dev_err(ddev, "unable to read config index %d "
 821                             "descriptor/%s: %d\n", cfgno, "start", result);
 822                         if (result != -EPIPE)
 823                                 goto err;
 824                         dev_err(ddev, "chopping to %d config(s)\n", cfgno);
 825                         dev->descriptor.bNumConfigurations = cfgno;
 826                         break;
 827                 } else if (result < 4) {
 828                         dev_err(ddev, "config index %d descriptor too short "
 829                             "(expected %i, got %i)\n", cfgno,
 830                             USB_DT_CONFIG_SIZE, result);
 831                         result = -EINVAL;
 832                         goto err;
 833                 }
 834                 length = max((int) le16_to_cpu(desc->wTotalLength),
 835                     USB_DT_CONFIG_SIZE);
 836
 837                 /* Now that we know the length, get the whole thing */
 838                 bigbuffer = kmalloc(length, GFP_KERNEL);
 839                 if (!bigbuffer) {
 840                         result = -ENOMEM;
 841                         goto err;
 842                 }
 843
 844                 if (dev->quirks & USB_QUIRK_DELAY_INIT)
 845                         msleep(100);
 846
 847                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 848                     bigbuffer, length);
 849                 if (result < 0) {
 850                         dev_err(ddev, "unable to read config index %d "
 851                             "descriptor/%s\n", cfgno, "all");
 852                         kfree(bigbuffer);
 853                         goto err;
 854                 }
 855                 if (result < length) {
 856                         dev_warn(ddev, "config index %d descriptor too short "
 857                             "(expected %i, got %i)\n", cfgno, length, result);
 858                         length = result;
 859                 }
 860
 861                 dev->rawdescriptors[cfgno] = bigbuffer;
 862
 863                 result = usb_parse_configuration(dev, cfgno,
 864                     &dev->config[cfgno], bigbuffer, length);
 865                 if (result < 0) {
 866                         ++cfgno;
 867                         goto err;
 868                 }
 869         }
 870         result = 0;
 871
 872 err:
 873         kfree(desc);
 874         dev->descriptor.bNumConfigurations = cfgno;
 875 err2:
 876         if (result == -ENOMEM)
 877                 dev_err(ddev, "out of memory\n");
 878         return result;
 879 }
 880
 881 void usb_release_bos_descriptor(struct usb_device *dev)
 882 {
 883         if (dev->bos) {
 884                 kfree(dev->bos->desc);
 885                 kfree(dev->bos);
 886                 dev->bos = NULL;
 887         }
 888 }
 889
 890 /* Get BOS descriptor set */
 891 int usb_get_bos_descriptor(struct usb_device *dev)
 892 {
 893         struct device *ddev = &dev->dev;
 894         struct usb_bos_descriptor *bos;
 895         struct usb_dev_cap_header *cap;
 896         unsigned char *buffer;
 897         int length, total_len, num, i;
 898         int ret;
 899
 900         bos = kzalloc(sizeof(struct usb_bos_descriptor), GFP_KERNEL);
 901         if (!bos)
 902                 return -ENOMEM;
 903
 904         /* Get BOS descriptor */
 905         ret = usb_get_descriptor(dev, USB_DT_BOS, 0, bos, USB_DT_BOS_SIZE);
 906         if (ret < USB_DT_BOS_SIZE) {
 907                 dev_err(ddev, "unable to get BOS descriptor\n");
 908                 if (ret >= 0)
 909                         ret = -ENOMSG;
 910                 kfree(bos);
 911                 return ret;
 912         }
 913
 914         length = bos->bLength;
 915         total_len = le16_to_cpu(bos->wTotalLength);
 916         num = bos->bNumDeviceCaps;
 917         kfree(bos);
 918         if (total_len < length)
 919                 return -EINVAL;
 920
 921         dev->bos = kzalloc(sizeof(struct usb_host_bos), GFP_KERNEL);
 922         if (!dev->bos)
 923                 return -ENOMEM;
 924
 925         /* Now let's get the whole BOS descriptor set */
 926         buffer = kzalloc(total_len, GFP_KERNEL);
 927         if (!buffer) {
 928                 ret = -ENOMEM;
 929                 goto err;
 930         }
 931         dev->bos->desc = (struct usb_bos_descriptor *)buffer;
 932
 933         ret = usb_get_descriptor(dev, USB_DT_BOS, 0, buffer, total_len);
 934         if (ret < total_len) {
 935                 dev_err(ddev, "unable to get BOS descriptor set\n");
 936                 if (ret >= 0)
 937                         ret = -ENOMSG;
 938                 goto err;
 939         }
 940         total_len -= length;
 941
 942         for (i = 0; i < num; i++) {
 943                 buffer += length;
 944                 cap = (struct usb_dev_cap_header *)buffer;
 945                 length = cap->bLength;
 946
 947                 if (total_len < length)
 948                         break;
 949                 total_len -= length;
 950
 951                 if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) {
 952                         dev_warn(ddev, "descriptor type invalid, skip\n");
 953                         continue;
 954                 }
 955
 956                 switch (cap->bDevCapabilityType) {
 957                 case USB_CAP_TYPE_WIRELESS_USB:
 958                         /* Wireless USB cap descriptor is handled by wusb */
 959                         break;
 960                 case USB_CAP_TYPE_EXT:
 961                         dev->bos->ext_cap =
 962                                 (struct usb_ext_cap_descriptor *)buffer;
 963                         break;
 964                 case USB_SS_CAP_TYPE:
 965                         dev->bos->ss_cap =
 966                                 (struct usb_ss_cap_descriptor *)buffer;
 967                         break;
 968                 case USB_SSP_CAP_TYPE:
 969                         dev->bos->ssp_cap =
 970                                 (struct usb_ssp_cap_descriptor *)buffer;
 971                         break;
 972                 case CONTAINER_ID_TYPE:
 973                         dev->bos->ss_id =
 974                                 (struct usb_ss_container_id_descriptor *)buffer;
 975                         break;
 976                 case USB_PTM_CAP_TYPE:
 977                         dev->bos->ptm_cap =
 978                                 (struct usb_ptm_cap_descriptor *)buffer;
 979                 default:
 980                         break;
 981                 }
 982         }
 983
 984         return 0;
 985
 986 err:
 987         usb_release_bos_descriptor(dev);
 988         return ret;
 989 }