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