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 int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
 207     int asnum, struct usb_host_interface *ifp, int num_ep,
 208     unsigned char *buffer, int size)
 209 {
 210         unsigned char *buffer0 = buffer;
 211         struct usb_endpoint_descriptor *d;
 212         struct usb_host_endpoint *endpoint;
 213         int n, i, j, retval;
 214         unsigned int maxp;
 215         const unsigned short *maxpacket_maxes;
 216
 217         d = (struct usb_endpoint_descriptor *) buffer;
 218         buffer += d->bLength;
 219         size -= d->bLength;
 220
 221         if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
 222                 n = USB_DT_ENDPOINT_AUDIO_SIZE;
 223         else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
 224                 n = USB_DT_ENDPOINT_SIZE;
 225         else {
 226                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 227                     "invalid endpoint descriptor of length %d, skipping\n",
 228                     cfgno, inum, asnum, d->bLength);
 229                 goto skip_to_next_endpoint_or_interface_descriptor;
 230         }
 231
 232         i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
 233         if (i >= 16 || i == 0) {
 234                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
 235                     "invalid endpoint with address 0x%X, skipping\n",
 236                     cfgno, inum, asnum, d->bEndpointAddress);
 237                 goto skip_to_next_endpoint_or_interface_descriptor;
 238         }
 239
 240         /* Only store as many endpoints as we have room for */
 241         if (ifp->desc.bNumEndpoints >= num_ep)
 242                 goto skip_to_next_endpoint_or_interface_descriptor;
 243
 244         /* Check for duplicate endpoint addresses */
 245         for (i = 0; i < ifp->desc.bNumEndpoints; ++i) {
 246                 if (ifp->endpoint[i].desc.bEndpointAddress ==
 247                     d->bEndpointAddress) {
 248                         dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n",
 249                             cfgno, inum, asnum, d->bEndpointAddress);
 250                         goto skip_to_next_endpoint_or_interface_descriptor;
 251                 }
 252         }
 253
 254         endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
 255         ++ifp->desc.bNumEndpoints;
 256
 257         memcpy(&endpoint->desc, d, n);
 258         INIT_LIST_HEAD(&endpoint->urb_list);
 259
 260         /*
 261          * Fix up bInterval values outside the legal range.
 262          * Use 10 or 8 ms if no proper value can be guessed.
 263          */
 264         i = 0;          /* i = min, j = max, n = default */
 265         j = 255;
 266         if (usb_endpoint_xfer_int(d)) {
 267                 i = 1;
 268                 switch (to_usb_device(ddev)->speed) {
 269                 case USB_SPEED_SUPER_PLUS:
 270                 case USB_SPEED_SUPER:
 271                 case USB_SPEED_HIGH:
 272                         /*
 273                          * Many device manufacturers are using full-speed
 274                          * bInterval values in high-speed interrupt endpoint
 275                          * descriptors. Try to fix those and fall back to an
 276                          * 8-ms default value otherwise.
 277                          */
 278                         n = fls(d->bInterval*8);
 279                         if (n == 0)
 280                                 n = 7;  /* 8 ms = 2^(7-1) uframes */
 281                         j = 16;
 282
 283                         /*
 284                          * Adjust bInterval for quirked devices.
 285                          */
 286                         /*
 287                          * This quirk fixes bIntervals reported in ms.
 288                          */
 289                         if (to_usb_device(ddev)->quirks &
 290                                 USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL) {
 291                                 n = clamp(fls(d->bInterval) + 3, i, j);
 292                                 i = j = n;
 293                         }
 294                         /*
 295                          * This quirk fixes bIntervals reported in
 296                          * linear microframes.
 297                          */
 298                         if (to_usb_device(ddev)->quirks &
 299                                 USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL) {
 300                                 n = clamp(fls(d->bInterval), i, j);
 301                                 i = j = n;
 302                         }
 303                         break;
 304                 default:                /* USB_SPEED_FULL or _LOW */
 305                         /*
 306                          * For low-speed, 10 ms is the official minimum.
 307                          * But some "overclocked" devices might want faster
 308                          * polling so we'll allow it.
 309                          */
 310                         n = 10;
 311                         break;
 312                 }
 313         } else if (usb_endpoint_xfer_isoc(d)) {
 314                 i = 1;
 315                 j = 16;
 316                 switch (to_usb_device(ddev)->speed) {
 317                 case USB_SPEED_HIGH:
 318                         n = 7;          /* 8 ms = 2^(7-1) uframes */
 319                         break;
 320                 default:                /* USB_SPEED_FULL */
 321                         n = 4;          /* 8 ms = 2^(4-1) frames */
 322                         break;
 323                 }
 324         }
 325         if (d->bInterval < i || d->bInterval > j) {
 326                 dev_warn(ddev, "config %d interface %d altsetting %d "
 327                     "endpoint 0x%X has an invalid bInterval %d, "
 328                     "changing to %d\n",
 329                     cfgno, inum, asnum,
 330                     d->bEndpointAddress, d->bInterval, n);
 331                 endpoint->desc.bInterval = n;
 332         }
 333
 334         /* Some buggy low-speed devices have Bulk endpoints, which is
 335          * explicitly forbidden by the USB spec.  In an attempt to make
 336          * them usable, we will try treating them as Interrupt endpoints.
 337          */
 338         if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
 339                         usb_endpoint_xfer_bulk(d)) {
 340                 dev_warn(ddev, "config %d interface %d altsetting %d "
 341                     "endpoint 0x%X is Bulk; changing to Interrupt\n",
 342                     cfgno, inum, asnum, d->bEndpointAddress);
 343                 endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
 344                 endpoint->desc.bInterval = 1;
 345                 if (usb_endpoint_maxp(&endpoint->desc) > 8)
 346                         endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
 347         }
 348
 349         /* Validate the wMaxPacketSize field */
 350         maxp = usb_endpoint_maxp(&endpoint->desc);
 351
 352         /* Find the highest legal maxpacket size for this endpoint */
 353         i = 0;          /* additional transactions per microframe */
 354         switch (to_usb_device(ddev)->speed) {
 355         case USB_SPEED_LOW:
 356                 maxpacket_maxes = low_speed_maxpacket_maxes;
 357                 break;
 358         case USB_SPEED_FULL:
 359                 maxpacket_maxes = full_speed_maxpacket_maxes;
 360                 break;
 361         case USB_SPEED_HIGH:
 362                 /* Bits 12..11 are allowed only for HS periodic endpoints */
 363                 if (usb_endpoint_xfer_int(d) || usb_endpoint_xfer_isoc(d)) {
 364                         i = maxp & (BIT(12) | BIT(11));
 365                         maxp &= ~i;
 366                 }
 367                 /* fallthrough */
 368         default:
 369                 maxpacket_maxes = high_speed_maxpacket_maxes;
 370                 break;
 371         case USB_SPEED_SUPER:
 372         case USB_SPEED_SUPER_PLUS:
 373                 maxpacket_maxes = super_speed_maxpacket_maxes;
 374                 break;
 375         }
 376         j = maxpacket_maxes[usb_endpoint_type(&endpoint->desc)];
 377
 378         if (maxp > j) {
 379                 dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid maxpacket %d, setting to %d\n",
 380                     cfgno, inum, asnum, d->bEndpointAddress, maxp, j);
 381                 maxp = j;
 382                 endpoint->desc.wMaxPacketSize = cpu_to_le16(i | maxp);
 383         }
 384
 385         /*
 386          * Some buggy high speed devices have bulk endpoints using
 387          * maxpacket sizes other than 512.  High speed HCDs may not
 388          * be able to handle that particular bug, so let's warn...
 389          */
 390         if (to_usb_device(ddev)->speed == USB_SPEED_HIGH
 391                         && usb_endpoint_xfer_bulk(d)) {
 392                 if (maxp != 512)
 393                         dev_warn(ddev, "config %d interface %d altsetting %d "
 394                                 "bulk endpoint 0x%X has invalid maxpacket %d\n",
 395                                 cfgno, inum, asnum, d->bEndpointAddress,
 396                                 maxp);
 397         }
 398
 399         /* Parse a possible SuperSpeed endpoint companion descriptor */
 400         if (to_usb_device(ddev)->speed >= USB_SPEED_SUPER)
 401                 usb_parse_ss_endpoint_companion(ddev, cfgno,
 402                                 inum, asnum, endpoint, buffer, size);
 403
 404         /* Skip over any Class Specific or Vendor Specific descriptors;
 405          * find the next endpoint or interface descriptor */
 406         endpoint->extra = buffer;
 407         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 408                         USB_DT_INTERFACE, &n);
 409         endpoint->extralen = i;
 410         retval = buffer - buffer0 + i;
 411         if (n > 0)
 412                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 413                     n, plural(n), "endpoint");
 414         return retval;
 415
 416 skip_to_next_endpoint_or_interface_descriptor:
 417         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 418             USB_DT_INTERFACE, NULL);
 419         return buffer - buffer0 + i;
 420 }
 421
 422 void usb_release_interface_cache(struct kref *ref)
 423 {
 424         struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
 425         int j;
 426
 427         for (j = 0; j < intfc->num_altsetting; j++) {
 428                 struct usb_host_interface *alt = &intfc->altsetting[j];
 429
 430                 kfree(alt->endpoint);
 431                 kfree(alt->string);
 432         }
 433         kfree(intfc);
 434 }
 435
 436 static int usb_parse_interface(struct device *ddev, int cfgno,
 437     struct usb_host_config *config, unsigned char *buffer, int size,
 438     u8 inums[], u8 nalts[])
 439 {
 440         unsigned char *buffer0 = buffer;
 441         struct usb_interface_descriptor *d;
 442         int inum, asnum;
 443         struct usb_interface_cache *intfc;
 444         struct usb_host_interface *alt;
 445         int i, n;
 446         int len, retval;
 447         int num_ep, num_ep_orig;
 448
 449         d = (struct usb_interface_descriptor *) buffer;
 450         buffer += d->bLength;
 451         size -= d->bLength;
 452
 453         if (d->bLength < USB_DT_INTERFACE_SIZE)
 454                 goto skip_to_next_interface_descriptor;
 455
 456         /* Which interface entry is this? */
 457         intfc = NULL;
 458         inum = d->bInterfaceNumber;
 459         for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 460                 if (inums[i] == inum) {
 461                         intfc = config->intf_cache[i];
 462                         break;
 463                 }
 464         }
 465         if (!intfc || intfc->num_altsetting >= nalts[i])
 466                 goto skip_to_next_interface_descriptor;
 467
 468         /* Check for duplicate altsetting entries */
 469         asnum = d->bAlternateSetting;
 470         for ((i = 0, alt = &intfc->altsetting[0]);
 471               i < intfc->num_altsetting;
 472              (++i, ++alt)) {
 473                 if (alt->desc.bAlternateSetting == asnum) {
 474                         dev_warn(ddev, "Duplicate descriptor for config %d "
 475                             "interface %d altsetting %d, skipping\n",
 476                             cfgno, inum, asnum);
 477                         goto skip_to_next_interface_descriptor;
 478                 }
 479         }
 480
 481         ++intfc->num_altsetting;
 482         memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
 483
 484         /* Skip over any Class Specific or Vendor Specific descriptors;
 485          * find the first endpoint or interface descriptor */
 486         alt->extra = buffer;
 487         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 488             USB_DT_INTERFACE, &n);
 489         alt->extralen = i;
 490         if (n > 0)
 491                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 492                     n, plural(n), "interface");
 493         buffer += i;
 494         size -= i;
 495
 496         /* Allocate space for the right(?) number of endpoints */
 497         num_ep = num_ep_orig = alt->desc.bNumEndpoints;
 498         alt->desc.bNumEndpoints = 0;            /* Use as a counter */
 499         if (num_ep > USB_MAXENDPOINTS) {
 500                 dev_warn(ddev, "too many endpoints for config %d interface %d "
 501                     "altsetting %d: %d, using maximum allowed: %d\n",
 502                     cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
 503                 num_ep = USB_MAXENDPOINTS;
 504         }
 505
 506         if (num_ep > 0) {
 507                 /* Can't allocate 0 bytes */
 508                 len = sizeof(struct usb_host_endpoint) * num_ep;
 509                 alt->endpoint = kzalloc(len, GFP_KERNEL);
 510                 if (!alt->endpoint)
 511                         return -ENOMEM;
 512         }
 513
 514         /* Parse all the endpoint descriptors */
 515         n = 0;
 516         while (size > 0) {
 517                 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
 518                      == USB_DT_INTERFACE)
 519                         break;
 520                 retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
 521                     num_ep, buffer, size);
 522                 if (retval < 0)
 523                         return retval;
 524                 ++n;
 525
 526                 buffer += retval;
 527                 size -= retval;
 528         }
 529
 530         if (n != num_ep_orig)
 531                 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
 532                     "endpoint descriptor%s, different from the interface "
 533                     "descriptor's value: %d\n",
 534                     cfgno, inum, asnum, n, plural(n), num_ep_orig);
 535         return buffer - buffer0;
 536
 537 skip_to_next_interface_descriptor:
 538         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 539             USB_DT_INTERFACE, NULL);
 540         return buffer - buffer0 + i;
 541 }
 542
 543 static int usb_parse_configuration(struct usb_device *dev, int cfgidx,
 544     struct usb_host_config *config, unsigned char *buffer, int size)
 545 {
 546         struct device *ddev = &dev->dev;
 547         unsigned char *buffer0 = buffer;
 548         int cfgno;
 549         int nintf, nintf_orig;
 550         int i, j, n;
 551         struct usb_interface_cache *intfc;
 552         unsigned char *buffer2;
 553         int size2;
 554         struct usb_descriptor_header *header;
 555         int len, retval;
 556         u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
 557         unsigned iad_num = 0;
 558
 559         memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
 560         nintf = nintf_orig = config->desc.bNumInterfaces;
 561         config->desc.bNumInterfaces = 0;        // Adjusted later
 562
 563         if (config->desc.bDescriptorType != USB_DT_CONFIG ||
 564             config->desc.bLength < USB_DT_CONFIG_SIZE ||
 565             config->desc.bLength > size) {
 566                 dev_err(ddev, "invalid descriptor for config index %d: "
 567                     "type = 0x%X, length = %d\n", cfgidx,
 568                     config->desc.bDescriptorType, config->desc.bLength);
 569                 return -EINVAL;
 570         }
 571         cfgno = config->desc.bConfigurationValue;
 572
 573         buffer += config->desc.bLength;
 574         size -= config->desc.bLength;
 575
 576         if (nintf > USB_MAXINTERFACES) {
 577                 dev_warn(ddev, "config %d has too many interfaces: %d, "
 578                     "using maximum allowed: %d\n",
 579                     cfgno, nintf, USB_MAXINTERFACES);
 580                 nintf = USB_MAXINTERFACES;
 581         }
 582
 583         /* Go through the descriptors, checking their length and counting the
 584          * number of altsettings for each interface */
 585         n = 0;
 586         for ((buffer2 = buffer, size2 = size);
 587               size2 > 0;
 588              (buffer2 += header->bLength, size2 -= header->bLength)) {
 589
 590                 if (size2 < sizeof(struct usb_descriptor_header)) {
 591                         dev_warn(ddev, "config %d descriptor has %d excess "
 592                             "byte%s, ignoring\n",
 593                             cfgno, size2, plural(size2));
 594                         break;
 595                 }
 596
 597                 header = (struct usb_descriptor_header *) buffer2;
 598                 if ((header->bLength > size2) || (header->bLength < 2)) {
 599                         dev_warn(ddev, "config %d has an invalid descriptor "
 600                             "of length %d, skipping remainder of the config\n",
 601                             cfgno, header->bLength);
 602                         break;
 603                 }
 604
 605                 if (header->bDescriptorType == USB_DT_INTERFACE) {
 606                         struct usb_interface_descriptor *d;
 607                         int inum;
 608
 609                         d = (struct usb_interface_descriptor *) header;
 610                         if (d->bLength < USB_DT_INTERFACE_SIZE) {
 611                                 dev_warn(ddev, "config %d has an invalid "
 612                                     "interface descriptor of length %d, "
 613                                     "skipping\n", cfgno, d->bLength);
 614                                 continue;
 615                         }
 616
 617                         inum = d->bInterfaceNumber;
 618
 619                         if ((dev->quirks & USB_QUIRK_HONOR_BNUMINTERFACES) &&
 620                             n >= nintf_orig) {
 621                                 dev_warn(ddev, "config %d has more interface "
 622                                     "descriptors, than it declares in "
 623                                     "bNumInterfaces, ignoring interface "
 624                                     "number: %d\n", cfgno, inum);
 625                                 continue;
 626                         }
 627
 628                         if (inum >= nintf_orig)
 629                                 dev_warn(ddev, "config %d has an invalid "
 630                                     "interface number: %d but max is %d\n",
 631                                     cfgno, inum, nintf_orig - 1);
 632
 633                         /* Have we already encountered this interface?
 634                          * Count its altsettings */
 635                         for (i = 0; i < n; ++i) {
 636                                 if (inums[i] == inum)
 637                                         break;
 638                         }
 639                         if (i < n) {
 640                                 if (nalts[i] < 255)
 641                                         ++nalts[i];
 642                         } else if (n < USB_MAXINTERFACES) {
 643                                 inums[n] = inum;
 644                                 nalts[n] = 1;
 645                                 ++n;
 646                         }
 647
 648                 } else if (header->bDescriptorType ==
 649                                 USB_DT_INTERFACE_ASSOCIATION) {
 650                         struct usb_interface_assoc_descriptor *d;
 651
 652                         d = (struct usb_interface_assoc_descriptor *)header;
 653                         if (d->bLength < USB_DT_INTERFACE_ASSOCIATION_SIZE) {
 654                                 dev_warn(ddev,
 655                                          "config %d has an invalid interface association descriptor of length %d, skipping\n",
 656                                          cfgno, d->bLength);
 657                                 continue;
 658                         }
 659
 660                         if (iad_num == USB_MAXIADS) {
 661                                 dev_warn(ddev, "found more Interface "
 662                                                "Association Descriptors "
 663                                                "than allocated for in "
 664                                                "configuration %d\n", cfgno);
 665                         } else {
 666                                 config->intf_assoc[iad_num] = d;
 667                                 iad_num++;
 668                         }
 669
 670                 } else if (header->bDescriptorType == USB_DT_DEVICE ||
 671                             header->bDescriptorType == USB_DT_CONFIG)
 672                         dev_warn(ddev, "config %d contains an unexpected "
 673                             "descriptor of type 0x%X, skipping\n",
 674                             cfgno, header->bDescriptorType);
 675
 676         }       /* for ((buffer2 = buffer, size2 = size); ...) */
 677         size = buffer2 - buffer;
 678         config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
 679
 680         if (n != nintf)
 681                 dev_warn(ddev, "config %d has %d interface%s, different from "
 682                     "the descriptor's value: %d\n",
 683                     cfgno, n, plural(n), nintf_orig);
 684         else if (n == 0)
 685                 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
 686         config->desc.bNumInterfaces = nintf = n;
 687
 688         /* Check for missing interface numbers */
 689         for (i = 0; i < nintf; ++i) {
 690                 for (j = 0; j < nintf; ++j) {
 691                         if (inums[j] == i)
 692                                 break;
 693                 }
 694                 if (j >= nintf)
 695                         dev_warn(ddev, "config %d has no interface number "
 696                             "%d\n", cfgno, i);
 697         }
 698
 699         /* Allocate the usb_interface_caches and altsetting arrays */
 700         for (i = 0; i < nintf; ++i) {
 701                 j = nalts[i];
 702                 if (j > USB_MAXALTSETTING) {
 703                         dev_warn(ddev, "too many alternate settings for "
 704                             "config %d interface %d: %d, "
 705                             "using maximum allowed: %d\n",
 706                             cfgno, inums[i], j, USB_MAXALTSETTING);
 707                         nalts[i] = j = USB_MAXALTSETTING;
 708                 }
 709
 710                 len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
 711                 config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
 712                 if (!intfc)
 713                         return -ENOMEM;
 714                 kref_init(&intfc->ref);
 715         }
 716
 717         /* FIXME: parse the BOS descriptor */
 718
 719         /* Skip over any Class Specific or Vendor Specific descriptors;
 720          * find the first interface descriptor */
 721         config->extra = buffer;
 722         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 723             USB_DT_INTERFACE, &n);
 724         config->extralen = i;
 725         if (n > 0)
 726                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 727                     n, plural(n), "configuration");
 728         buffer += i;
 729         size -= i;
 730
 731         /* Parse all the interface/altsetting descriptors */
 732         while (size > 0) {
 733                 retval = usb_parse_interface(ddev, cfgno, config,
 734                     buffer, size, inums, nalts);
 735                 if (retval < 0)
 736                         return retval;
 737
 738                 buffer += retval;
 739                 size -= retval;
 740         }
 741
 742         /* Check for missing altsettings */
 743         for (i = 0; i < nintf; ++i) {
 744                 intfc = config->intf_cache[i];
 745                 for (j = 0; j < intfc->num_altsetting; ++j) {
 746                         for (n = 0; n < intfc->num_altsetting; ++n) {
 747                                 if (intfc->altsetting[n].desc.
 748                                     bAlternateSetting == j)
 749                                         break;
 750                         }
 751                         if (n >= intfc->num_altsetting)
 752                                 dev_warn(ddev, "config %d interface %d has no "
 753                                     "altsetting %d\n", cfgno, inums[i], j);
 754                 }
 755         }
 756
 757         return 0;
 758 }
 759
 760 /* hub-only!! ... and only exported for reset/reinit path.
 761  * otherwise used internally on disconnect/destroy path
 762  */
 763 void usb_destroy_configuration(struct usb_device *dev)
 764 {
 765         int c, i;
 766
 767         if (!dev->config)
 768                 return;
 769
 770         if (dev->rawdescriptors) {
 771                 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
 772                         kfree(dev->rawdescriptors[i]);
 773
 774                 kfree(dev->rawdescriptors);
 775                 dev->rawdescriptors = NULL;
 776         }
 777
 778         for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
 779                 struct usb_host_config *cf = &dev->config[c];
 780
 781                 kfree(cf->string);
 782                 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
 783                         if (cf->intf_cache[i])
 784                                 kref_put(&cf->intf_cache[i]->ref,
 785                                           usb_release_interface_cache);
 786                 }
 787         }
 788         kfree(dev->config);
 789         dev->config = NULL;
 790 }
 791
 792
 793 /*
 794  * Get the USB config descriptors, cache and parse'em
 795  *
 796  * hub-only!! ... and only in reset path, or usb_new_device()
 797  * (used by real hubs and virtual root hubs)
 798  */
 799 int usb_get_configuration(struct usb_device *dev)
 800 {
 801         struct device *ddev = &dev->dev;
 802         int ncfg = dev->descriptor.bNumConfigurations;
 803         int result = 0;
 804         unsigned int cfgno, length;
 805         unsigned char *bigbuffer;
 806         struct usb_config_descriptor *desc;
 807
 808         cfgno = 0;
 809         result = -ENOMEM;
 810         if (ncfg > USB_MAXCONFIG) {
 811                 dev_warn(ddev, "too many configurations: %d, "
 812                     "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
 813                 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
 814         }
 815
 816         if (ncfg < 1) {
 817                 dev_err(ddev, "no configurations\n");
 818                 return -EINVAL;
 819         }
 820
 821         length = ncfg * sizeof(struct usb_host_config);
 822         dev->config = kzalloc(length, GFP_KERNEL);
 823         if (!dev->config)
 824                 goto err2;
 825
 826         length = ncfg * sizeof(char *);
 827         dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
 828         if (!dev->rawdescriptors)
 829                 goto err2;
 830
 831         desc = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
 832         if (!desc)
 833                 goto err2;
 834
 835         result = 0;
 836         for (; cfgno < ncfg; cfgno++) {
 837                 /* We grab just the first descriptor so we know how long
 838                  * the whole configuration is */
 839                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 840                     desc, USB_DT_CONFIG_SIZE);
 841                 if (result < 0) {
 842                         dev_err(ddev, "unable to read config index %d "
 843                             "descriptor/%s: %d\n", cfgno, "start", result);
 844                         if (result != -EPIPE)
 845                                 goto err;
 846                         dev_err(ddev, "chopping to %d config(s)\n", cfgno);
 847                         dev->descriptor.bNumConfigurations = cfgno;
 848                         break;
 849                 } else if (result < 4) {
 850                         dev_err(ddev, "config index %d descriptor too short "
 851                             "(expected %i, got %i)\n", cfgno,
 852                             USB_DT_CONFIG_SIZE, result);
 853                         result = -EINVAL;
 854                         goto err;
 855                 }
 856                 length = max((int) le16_to_cpu(desc->wTotalLength),
 857                     USB_DT_CONFIG_SIZE);
 858
 859                 /* Now that we know the length, get the whole thing */
 860                 bigbuffer = kmalloc(length, GFP_KERNEL);
 861                 if (!bigbuffer) {
 862                         result = -ENOMEM;
 863                         goto err;
 864                 }
 865
 866                 if (dev->quirks & USB_QUIRK_DELAY_INIT)
 867                         msleep(200);
 868
 869                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 870                     bigbuffer, length);
 871                 if (result < 0) {
 872                         dev_err(ddev, "unable to read config index %d "
 873                             "descriptor/%s\n", cfgno, "all");
 874                         kfree(bigbuffer);
 875                         goto err;
 876                 }
 877                 if (result < length) {
 878                         dev_warn(ddev, "config index %d descriptor too short "
 879                             "(expected %i, got %i)\n", cfgno, length, result);
 880                         length = result;
 881                 }
 882
 883                 dev->rawdescriptors[cfgno] = bigbuffer;
 884
 885                 result = usb_parse_configuration(dev, cfgno,
 886                     &dev->config[cfgno], bigbuffer, length);
 887                 if (result < 0) {
 888                         ++cfgno;
 889                         goto err;
 890                 }
 891         }
 892         result = 0;
 893
 894 err:
 895         kfree(desc);
 896         dev->descriptor.bNumConfigurations = cfgno;
 897 err2:
 898         if (result == -ENOMEM)
 899                 dev_err(ddev, "out of memory\n");
 900         return result;
 901 }
 902
 903 void usb_release_bos_descriptor(struct usb_device *dev)
 904 {
 905         if (dev->bos) {
 906                 kfree(dev->bos->desc);
 907                 kfree(dev->bos);
 908                 dev->bos = NULL;
 909         }
 910 }
 911
 912 static const __u8 bos_desc_len[256] = {
 913         [USB_CAP_TYPE_WIRELESS_USB] = USB_DT_USB_WIRELESS_CAP_SIZE,
 914         [USB_CAP_TYPE_EXT]          = USB_DT_USB_EXT_CAP_SIZE,
 915         [USB_SS_CAP_TYPE]           = USB_DT_USB_SS_CAP_SIZE,
 916         [USB_SSP_CAP_TYPE]          = USB_DT_USB_SSP_CAP_SIZE(1),
 917         [CONTAINER_ID_TYPE]         = USB_DT_USB_SS_CONTN_ID_SIZE,
 918         [USB_PTM_CAP_TYPE]          = USB_DT_USB_PTM_ID_SIZE,
 919 };
 920
 921 /* Get BOS descriptor set */
 922 int usb_get_bos_descriptor(struct usb_device *dev)
 923 {
 924         struct device *ddev = &dev->dev;
 925         struct usb_bos_descriptor *bos;
 926         struct usb_dev_cap_header *cap;
 927         struct usb_ssp_cap_descriptor *ssp_cap;
 928         unsigned char *buffer;
 929         int length, total_len, num, i, ssac;
 930         __u8 cap_type;
 931         int ret;
 932
 933         bos = kzalloc(sizeof(struct usb_bos_descriptor), GFP_KERNEL);
 934         if (!bos)
 935                 return -ENOMEM;
 936
 937         /* Get BOS descriptor */
 938         ret = usb_get_descriptor(dev, USB_DT_BOS, 0, bos, USB_DT_BOS_SIZE);
 939         if (ret < USB_DT_BOS_SIZE) {
 940                 dev_err(ddev, "unable to get BOS descriptor\n");
 941                 if (ret >= 0)
 942                         ret = -ENOMSG;
 943                 kfree(bos);
 944                 return ret;
 945         }
 946
 947         length = bos->bLength;
 948         total_len = le16_to_cpu(bos->wTotalLength);
 949         num = bos->bNumDeviceCaps;
 950         kfree(bos);
 951         if (total_len < length)
 952                 return -EINVAL;
 953
 954         dev->bos = kzalloc(sizeof(struct usb_host_bos), GFP_KERNEL);
 955         if (!dev->bos)
 956                 return -ENOMEM;
 957
 958         /* Now let's get the whole BOS descriptor set */
 959         buffer = kzalloc(total_len, GFP_KERNEL);
 960         if (!buffer) {
 961                 ret = -ENOMEM;
 962                 goto err;
 963         }
 964         dev->bos->desc = (struct usb_bos_descriptor *)buffer;
 965
 966         ret = usb_get_descriptor(dev, USB_DT_BOS, 0, buffer, total_len);
 967         if (ret < total_len) {
 968                 dev_err(ddev, "unable to get BOS descriptor set\n");
 969                 if (ret >= 0)
 970                         ret = -ENOMSG;
 971                 goto err;
 972         }
 973         total_len -= length;
 974
 975         for (i = 0; i < num; i++) {
 976                 buffer += length;
 977                 cap = (struct usb_dev_cap_header *)buffer;
 978
 979                 if (total_len < sizeof(*cap) || total_len < cap->bLength) {
 980                         dev->bos->desc->bNumDeviceCaps = i;
 981                         break;
 982                 }
 983                 cap_type = cap->bDevCapabilityType;
 984                 length = cap->bLength;
 985                 if (bos_desc_len[cap_type] && length < bos_desc_len[cap_type]) {
 986                         dev->bos->desc->bNumDeviceCaps = i;
 987                         break;
 988                 }
 989
 990                 total_len -= length;
 991
 992                 if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) {
 993                         dev_warn(ddev, "descriptor type invalid, skip\n");
 994                         continue;
 995                 }
 996
 997                 switch (cap_type) {
 998                 case USB_CAP_TYPE_WIRELESS_USB:
 999                         /* Wireless USB cap descriptor is handled by wusb */
1000                         break;
1001                 case USB_CAP_TYPE_EXT:
1002                         dev->bos->ext_cap =
1003                                 (struct usb_ext_cap_descriptor *)buffer;
1004                         break;
1005                 case USB_SS_CAP_TYPE:
1006                         dev->bos->ss_cap =
1007                                 (struct usb_ss_cap_descriptor *)buffer;
1008                         break;
1009                 case USB_SSP_CAP_TYPE:
1010                         ssp_cap = (struct usb_ssp_cap_descriptor *)buffer;
1011                         ssac = (le32_to_cpu(ssp_cap->bmAttributes) &
1012                                 USB_SSP_SUBLINK_SPEED_ATTRIBS);
1013                         if (length >= USB_DT_USB_SSP_CAP_SIZE(ssac))
1014                                 dev->bos->ssp_cap = ssp_cap;
1015                         break;
1016                 case CONTAINER_ID_TYPE:
1017                         dev->bos->ss_id =
1018                                 (struct usb_ss_container_id_descriptor *)buffer;
1019                         break;
1020                 case USB_PTM_CAP_TYPE:
1021                         dev->bos->ptm_cap =
1022                                 (struct usb_ptm_cap_descriptor *)buffer;
1023                 default:
1024                         break;
1025                 }
1026         }
1027
1028         return 0;
1029
1030 err:
1031         usb_release_bos_descriptor(dev);
1032         return ret;
1033 }