drivers/usb/wusbcore/cbaf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Wireless USB - Cable Based Association
   4  *
   5  *
   6  * Copyright (C) 2006 Intel Corporation
   7  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   8  * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
   9  *
  10  * WUSB devices have to be paired (associated in WUSB lingo) so
  11  * that they can connect to the system.
  12  *
  13  * One way of pairing is using CBA-Cable Based Association. First
  14  * time you plug the device with a cable, association is done between
  15  * host and device and subsequent times, you can connect wirelessly
  16  * without having to associate again. That's the idea.
  17  *
  18  * This driver does nothing Earth shattering. It just provides an
  19  * interface to chat with the wire-connected device so we can get a
  20  * CDID (device ID) that might have been previously associated to a
  21  * CHID (host ID) and to set up a new <CHID,CDID,CK> triplet
  22  * (connection context), with the CK being the secret, or connection
  23  * key. This is the pairing data.
  24  *
  25  * When a device with the CBA capability connects, the probe routine
  26  * just creates a bunch of sysfs files that a user space enumeration
  27  * manager uses to allow it to connect wirelessly to the system or not.
  28  *
  29  * The process goes like this:
  30  *
  31  * 1. Device plugs, cbaf is loaded, notifications happen.
  32  *
  33  * 2. The connection manager (CM) sees a device with CBAF capability
  34  *    (the wusb_chid etc. files in /sys/devices/blah/OURDEVICE).
  35  *
  36  * 3. The CM writes the host name, supported band groups, and the CHID
  37  *    (host ID) into the wusb_host_name, wusb_host_band_groups and
  38  *    wusb_chid files. These get sent to the device and the CDID (if
  39  *    any) for this host is requested.
  40  *
  41  * 4. The CM can verify that the device's supported band groups
  42  *    (wusb_device_band_groups) are compatible with the host.
  43  *
  44  * 5. The CM reads the wusb_cdid file.
  45  *
  46  * 6. The CM looks up its database
  47  *
  48  * 6.1 If it has a matching CHID,CDID entry, the device has been
  49  *     authorized before (paired) and nothing further needs to be
  50  *     done.
  51  *
  52  * 6.2 If the CDID is zero (or the CM doesn't find a matching CDID in
  53  *     its database), the device is assumed to be not known.  The CM
  54  *     may associate the host with device by: writing a randomly
  55  *     generated CDID to wusb_cdid and then a random CK to wusb_ck
  56  *     (this uploads the new CC to the device).
  57  *
  58  *     CMD may choose to prompt the user before associating with a new
  59  *     device.
  60  *
  61  * 7. Device is unplugged.
  62  *
  63  * When the device tries to connect wirelessly, it will present its
  64  * CDID to the WUSB host controller.  The CM will query the
  65  * database. If the CHID/CDID pair found, it will (with a 4-way
  66  * handshake) challenge the device to demonstrate it has the CK secret
  67  * key (from our database) without actually exchanging it. Once
  68  * satisfied, crypto keys are derived from the CK, the device is
  69  * connected and all communication is encrypted.
  70  *
  71  * References:
  72  *   [WUSB-AM] Association Models Supplement to the Certified Wireless
  73  *             Universal Serial Bus Specification, version 1.0.
  74  */
  75 #include <linux/module.h>
  76 #include <linux/ctype.h>
  77 #include <linux/usb.h>
  78 #include <linux/interrupt.h>
  79 #include <linux/delay.h>
  80 #include <linux/random.h>
  81 #include <linux/slab.h>
  82 #include <linux/mutex.h>
  83 #include <linux/uwb.h>
  84 #include <linux/usb/wusb.h>
  85 #include <linux/usb/association.h>
  86
  87 #define CBA_NAME_LEN 0x40 /* [WUSB-AM] table 4-7 */
  88
  89 /* An instance of a Cable-Based-Association-Framework device */
  90 struct cbaf {
  91         struct usb_device *usb_dev;
  92         struct usb_interface *usb_iface;
  93         void *buffer;
  94         size_t buffer_size;
  95
  96         struct wusb_ckhdid chid;
  97         char host_name[CBA_NAME_LEN];
  98         u16 host_band_groups;
  99
 100         struct wusb_ckhdid cdid;
 101         char device_name[CBA_NAME_LEN];
 102         u16 device_band_groups;
 103
 104         struct wusb_ckhdid ck;
 105 };
 106
 107 /*
 108  * Verify that a CBAF USB-interface has what we need
 109  *
 110  * According to [WUSB-AM], CBA devices should provide at least two
 111  * interfaces:
 112  *  - RETRIEVE_HOST_INFO
 113  *  - ASSOCIATE
 114  *
 115  * If the device doesn't provide these interfaces, we do not know how
 116  * to deal with it.
 117  */
 118 static int cbaf_check(struct cbaf *cbaf)
 119 {
 120         int result;
 121         struct device *dev = &cbaf->usb_iface->dev;
 122         struct wusb_cbaf_assoc_info *assoc_info;
 123         struct wusb_cbaf_assoc_request *assoc_request;
 124         size_t assoc_size;
 125         void *itr, *top;
 126         int ar_rhi = 0, ar_assoc = 0;
 127
 128         result = usb_control_msg(
 129                 cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
 130                 CBAF_REQ_GET_ASSOCIATION_INFORMATION,
 131                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 132                 0, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
 133                 cbaf->buffer, cbaf->buffer_size, USB_CTRL_GET_TIMEOUT);
 134         if (result < 0) {
 135                 dev_err(dev, "Cannot get available association types: %d\n",
 136                         result);
 137                 return result;
 138         }
 139
 140         assoc_info = cbaf->buffer;
 141         if (result < sizeof(*assoc_info)) {
 142                 dev_err(dev, "Not enough data to decode association info "
 143                         "header (%zu vs %zu bytes required)\n",
 144                         (size_t)result, sizeof(*assoc_info));
 145                 return result;
 146         }
 147
 148         assoc_size = le16_to_cpu(assoc_info->Length);
 149         if (result < assoc_size) {
 150                 dev_err(dev, "Not enough data to decode association info "
 151                         "(%zu vs %zu bytes required)\n",
 152                         (size_t)assoc_size, sizeof(*assoc_info));
 153                 return result;
 154         }
 155         /*
 156          * From now on, we just verify, but won't error out unless we
 157          * don't find the AR_TYPE_WUSB_{RETRIEVE_HOST_INFO,ASSOCIATE}
 158          * types.
 159          */
 160         itr = cbaf->buffer + sizeof(*assoc_info);
 161         top = cbaf->buffer + assoc_size;
 162         dev_dbg(dev, "Found %u association requests (%zu bytes)\n",
 163                  assoc_info->NumAssociationRequests, assoc_size);
 164
 165         while (itr < top) {
 166                 u16 ar_type, ar_subtype;
 167                 u32 ar_size;
 168                 const char *ar_name;
 169
 170                 assoc_request = itr;
 171
 172                 if (top - itr < sizeof(*assoc_request)) {
 173                         dev_err(dev, "Not enough data to decode association "
 174                                 "request (%zu vs %zu bytes needed)\n",
 175                                 top - itr, sizeof(*assoc_request));
 176                         break;
 177                 }
 178
 179                 ar_type = le16_to_cpu(assoc_request->AssociationTypeId);
 180                 ar_subtype = le16_to_cpu(assoc_request->AssociationSubTypeId);
 181                 ar_size = le32_to_cpu(assoc_request->AssociationTypeInfoSize);
 182                 ar_name = "unknown";
 183
 184                 switch (ar_type) {
 185                 case AR_TYPE_WUSB:
 186                         /* Verify we have what is mandated by [WUSB-AM]. */
 187                         switch (ar_subtype) {
 188                         case AR_TYPE_WUSB_RETRIEVE_HOST_INFO:
 189                                 ar_name = "RETRIEVE_HOST_INFO";
 190                                 ar_rhi = 1;
 191                                 break;
 192                         case AR_TYPE_WUSB_ASSOCIATE:
 193                                 /* send assoc data */
 194                                 ar_name = "ASSOCIATE";
 195                                 ar_assoc = 1;
 196                                 break;
 197                         }
 198                         break;
 199                 }
 200
 201                 dev_dbg(dev, "Association request #%02u: 0x%04x/%04x "
 202                          "(%zu bytes): %s\n",
 203                          assoc_request->AssociationDataIndex, ar_type,
 204                          ar_subtype, (size_t)ar_size, ar_name);
 205
 206                 itr += sizeof(*assoc_request);
 207         }
 208
 209         if (!ar_rhi) {
 210                 dev_err(dev, "Missing RETRIEVE_HOST_INFO association "
 211                         "request\n");
 212                 return -EINVAL;
 213         }
 214         if (!ar_assoc) {
 215                 dev_err(dev, "Missing ASSOCIATE association request\n");
 216                 return -EINVAL;
 217         }
 218
 219         return 0;
 220 }
 221
 222 static const struct wusb_cbaf_host_info cbaf_host_info_defaults = {
 223         .AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
 224         .AssociationTypeId        = cpu_to_le16(AR_TYPE_WUSB),
 225         .AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
 226         .AssociationSubTypeId = cpu_to_le16(AR_TYPE_WUSB_RETRIEVE_HOST_INFO),
 227         .CHID_hdr                 = WUSB_AR_CHID,
 228         .LangID_hdr               = WUSB_AR_LangID,
 229         .HostFriendlyName_hdr     = WUSB_AR_HostFriendlyName,
 230 };
 231
 232 /* Send WUSB host information (CHID and name) to a CBAF device */
 233 static int cbaf_send_host_info(struct cbaf *cbaf)
 234 {
 235         struct wusb_cbaf_host_info *hi;
 236         size_t name_len;
 237         size_t hi_size;
 238
 239         hi = cbaf->buffer;
 240         memset(hi, 0, sizeof(*hi));
 241         *hi = cbaf_host_info_defaults;
 242         hi->CHID = cbaf->chid;
 243         hi->LangID = 0; /* FIXME: I guess... */
 244         strlcpy(hi->HostFriendlyName, cbaf->host_name, CBA_NAME_LEN);
 245         name_len = strlen(cbaf->host_name);
 246         hi->HostFriendlyName_hdr.len = cpu_to_le16(name_len);
 247         hi_size = sizeof(*hi) + name_len;
 248
 249         return usb_control_msg(cbaf->usb_dev,
 250                         usb_sndctrlpipe(cbaf->usb_dev, 0),
 251                         CBAF_REQ_SET_ASSOCIATION_RESPONSE,
 252                         USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 253                         0x0101,
 254                         cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
 255                         hi, hi_size, USB_CTRL_SET_TIMEOUT);
 256 }
 257
 258 /*
 259  * Get device's information (CDID) associated to CHID
 260  *
 261  * The device will return it's information (CDID, name, bandgroups)
 262  * associated to the CHID we have set before, or 0 CDID and default
 263  * name and bandgroup if no CHID set or unknown.
 264  */
 265 static int cbaf_cdid_get(struct cbaf *cbaf)
 266 {
 267         int result;
 268         struct device *dev = &cbaf->usb_iface->dev;
 269         struct wusb_cbaf_device_info *di;
 270         size_t needed;
 271
 272         di = cbaf->buffer;
 273         result = usb_control_msg(
 274                 cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
 275                 CBAF_REQ_GET_ASSOCIATION_REQUEST,
 276                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 277                 0x0200, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
 278                 di, cbaf->buffer_size, USB_CTRL_GET_TIMEOUT);
 279         if (result < 0) {
 280                 dev_err(dev, "Cannot request device information: %d\n",
 281                         result);
 282                 return result;
 283         }
 284
 285         needed = result < sizeof(*di) ? sizeof(*di) : le32_to_cpu(di->Length);
 286         if (result < needed) {
 287                 dev_err(dev, "Not enough data in DEVICE_INFO reply (%zu vs "
 288                         "%zu bytes needed)\n", (size_t)result, needed);
 289                 return -ENOENT;
 290         }
 291
 292         strlcpy(cbaf->device_name, di->DeviceFriendlyName, CBA_NAME_LEN);
 293         cbaf->cdid = di->CDID;
 294         cbaf->device_band_groups = le16_to_cpu(di->BandGroups);
 295
 296         return 0;
 297 }
 298
 299 static ssize_t cbaf_wusb_chid_show(struct device *dev,
 300                                         struct device_attribute *attr,
 301                                         char *buf)
 302 {
 303         struct usb_interface *iface = to_usb_interface(dev);
 304         struct cbaf *cbaf = usb_get_intfdata(iface);
 305         char pr_chid[WUSB_CKHDID_STRSIZE];
 306
 307         ckhdid_printf(pr_chid, sizeof(pr_chid), &cbaf->chid);
 308         return scnprintf(buf, PAGE_SIZE, "%s\n", pr_chid);
 309 }
 310
 311 static ssize_t cbaf_wusb_chid_store(struct device *dev,
 312                                          struct device_attribute *attr,
 313                                          const char *buf, size_t size)
 314 {
 315         ssize_t result;
 316         struct usb_interface *iface = to_usb_interface(dev);
 317         struct cbaf *cbaf = usb_get_intfdata(iface);
 318
 319         result = sscanf(buf,
 320                         "%02hhx %02hhx %02hhx %02hhx "
 321                         "%02hhx %02hhx %02hhx %02hhx "
 322                         "%02hhx %02hhx %02hhx %02hhx "
 323                         "%02hhx %02hhx %02hhx %02hhx",
 324                         &cbaf->chid.data[0] , &cbaf->chid.data[1],
 325                         &cbaf->chid.data[2] , &cbaf->chid.data[3],
 326                         &cbaf->chid.data[4] , &cbaf->chid.data[5],
 327                         &cbaf->chid.data[6] , &cbaf->chid.data[7],
 328                         &cbaf->chid.data[8] , &cbaf->chid.data[9],
 329                         &cbaf->chid.data[10], &cbaf->chid.data[11],
 330                         &cbaf->chid.data[12], &cbaf->chid.data[13],
 331                         &cbaf->chid.data[14], &cbaf->chid.data[15]);
 332
 333         if (result != 16)
 334                 return -EINVAL;
 335
 336         result = cbaf_send_host_info(cbaf);
 337         if (result < 0)
 338                 return result;
 339         result = cbaf_cdid_get(cbaf);
 340         if (result < 0)
 341                 return result;
 342         return size;
 343 }
 344 static DEVICE_ATTR(wusb_chid, 0600, cbaf_wusb_chid_show, cbaf_wusb_chid_store);
 345
 346 static ssize_t cbaf_wusb_host_name_show(struct device *dev,
 347                                         struct device_attribute *attr,
 348                                         char *buf)
 349 {
 350         struct usb_interface *iface = to_usb_interface(dev);
 351         struct cbaf *cbaf = usb_get_intfdata(iface);
 352
 353         return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->host_name);
 354 }
 355
 356 static ssize_t cbaf_wusb_host_name_store(struct device *dev,
 357                                          struct device_attribute *attr,
 358                                          const char *buf, size_t size)
 359 {
 360         ssize_t result;
 361         struct usb_interface *iface = to_usb_interface(dev);
 362         struct cbaf *cbaf = usb_get_intfdata(iface);
 363
 364         result = sscanf(buf, "%63s", cbaf->host_name);
 365         if (result != 1)
 366                 return -EINVAL;
 367
 368         return size;
 369 }
 370 static DEVICE_ATTR(wusb_host_name, 0600, cbaf_wusb_host_name_show,
 371                                          cbaf_wusb_host_name_store);
 372
 373 static ssize_t cbaf_wusb_host_band_groups_show(struct device *dev,
 374                                                struct device_attribute *attr,
 375                                                char *buf)
 376 {
 377         struct usb_interface *iface = to_usb_interface(dev);
 378         struct cbaf *cbaf = usb_get_intfdata(iface);
 379
 380         return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->host_band_groups);
 381 }
 382
 383 static ssize_t cbaf_wusb_host_band_groups_store(struct device *dev,
 384                                                 struct device_attribute *attr,
 385                                                 const char *buf, size_t size)
 386 {
 387         ssize_t result;
 388         struct usb_interface *iface = to_usb_interface(dev);
 389         struct cbaf *cbaf = usb_get_intfdata(iface);
 390         u16 band_groups = 0;
 391
 392         result = sscanf(buf, "%04hx", &band_groups);
 393         if (result != 1)
 394                 return -EINVAL;
 395
 396         cbaf->host_band_groups = band_groups;
 397
 398         return size;
 399 }
 400
 401 static DEVICE_ATTR(wusb_host_band_groups, 0600,
 402                    cbaf_wusb_host_band_groups_show,
 403                    cbaf_wusb_host_band_groups_store);
 404
 405 static const struct wusb_cbaf_device_info cbaf_device_info_defaults = {
 406         .Length_hdr               = WUSB_AR_Length,
 407         .CDID_hdr                 = WUSB_AR_CDID,
 408         .BandGroups_hdr           = WUSB_AR_BandGroups,
 409         .LangID_hdr               = WUSB_AR_LangID,
 410         .DeviceFriendlyName_hdr   = WUSB_AR_DeviceFriendlyName,
 411 };
 412
 413 static ssize_t cbaf_wusb_cdid_show(struct device *dev,
 414                                    struct device_attribute *attr, char *buf)
 415 {
 416         struct usb_interface *iface = to_usb_interface(dev);
 417         struct cbaf *cbaf = usb_get_intfdata(iface);
 418         char pr_cdid[WUSB_CKHDID_STRSIZE];
 419
 420         ckhdid_printf(pr_cdid, sizeof(pr_cdid), &cbaf->cdid);
 421         return scnprintf(buf, PAGE_SIZE, "%s\n", pr_cdid);
 422 }
 423
 424 static ssize_t cbaf_wusb_cdid_store(struct device *dev,
 425                                 struct device_attribute *attr,
 426                                 const char *buf, size_t size)
 427 {
 428         ssize_t result;
 429         struct usb_interface *iface = to_usb_interface(dev);
 430         struct cbaf *cbaf = usb_get_intfdata(iface);
 431         struct wusb_ckhdid cdid;
 432
 433         result = sscanf(buf,
 434                         "%02hhx %02hhx %02hhx %02hhx "
 435                         "%02hhx %02hhx %02hhx %02hhx "
 436                         "%02hhx %02hhx %02hhx %02hhx "
 437                         "%02hhx %02hhx %02hhx %02hhx",
 438                         &cdid.data[0] , &cdid.data[1],
 439                         &cdid.data[2] , &cdid.data[3],
 440                         &cdid.data[4] , &cdid.data[5],
 441                         &cdid.data[6] , &cdid.data[7],
 442                         &cdid.data[8] , &cdid.data[9],
 443                         &cdid.data[10], &cdid.data[11],
 444                         &cdid.data[12], &cdid.data[13],
 445                         &cdid.data[14], &cdid.data[15]);
 446         if (result != 16)
 447                 return -EINVAL;
 448
 449         cbaf->cdid = cdid;
 450
 451         return size;
 452 }
 453 static DEVICE_ATTR(wusb_cdid, 0600, cbaf_wusb_cdid_show, cbaf_wusb_cdid_store);
 454
 455 static ssize_t cbaf_wusb_device_band_groups_show(struct device *dev,
 456                                                  struct device_attribute *attr,
 457                                                  char *buf)
 458 {
 459         struct usb_interface *iface = to_usb_interface(dev);
 460         struct cbaf *cbaf = usb_get_intfdata(iface);
 461
 462         return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->device_band_groups);
 463 }
 464
 465 static DEVICE_ATTR(wusb_device_band_groups, 0600,
 466                    cbaf_wusb_device_band_groups_show,
 467                    NULL);
 468
 469 static ssize_t cbaf_wusb_device_name_show(struct device *dev,
 470                                         struct device_attribute *attr,
 471                                         char *buf)
 472 {
 473         struct usb_interface *iface = to_usb_interface(dev);
 474         struct cbaf *cbaf = usb_get_intfdata(iface);
 475
 476         return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->device_name);
 477 }
 478 static DEVICE_ATTR(wusb_device_name, 0600, cbaf_wusb_device_name_show, NULL);
 479
 480 static const struct wusb_cbaf_cc_data cbaf_cc_data_defaults = {
 481         .AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
 482         .AssociationTypeId        = cpu_to_le16(AR_TYPE_WUSB),
 483         .AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
 484         .AssociationSubTypeId     = cpu_to_le16(AR_TYPE_WUSB_ASSOCIATE),
 485         .Length_hdr               = WUSB_AR_Length,
 486         .Length         = cpu_to_le32(sizeof(struct wusb_cbaf_cc_data)),
 487         .ConnectionContext_hdr    = WUSB_AR_ConnectionContext,
 488         .BandGroups_hdr           = WUSB_AR_BandGroups,
 489 };
 490
 491 static const struct wusb_cbaf_cc_data_fail cbaf_cc_data_fail_defaults = {
 492         .AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
 493         .AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
 494         .Length_hdr               = WUSB_AR_Length,
 495         .AssociationStatus_hdr    = WUSB_AR_AssociationStatus,
 496 };
 497
 498 /*
 499  * Send a new CC to the device.
 500  */
 501 static int cbaf_cc_upload(struct cbaf *cbaf)
 502 {
 503         int result;
 504         struct device *dev = &cbaf->usb_iface->dev;
 505         struct wusb_cbaf_cc_data *ccd;
 506         char pr_cdid[WUSB_CKHDID_STRSIZE];
 507
 508         ccd =  cbaf->buffer;
 509         *ccd = cbaf_cc_data_defaults;
 510         ccd->CHID = cbaf->chid;
 511         ccd->CDID = cbaf->cdid;
 512         ccd->CK = cbaf->ck;
 513         ccd->BandGroups = cpu_to_le16(cbaf->host_band_groups);
 514
 515         dev_dbg(dev, "Trying to upload CC:\n");
 516         ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CHID);
 517         dev_dbg(dev, "  CHID       %s\n", pr_cdid);
 518         ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CDID);
 519         dev_dbg(dev, "  CDID       %s\n", pr_cdid);
 520         dev_dbg(dev, "  Bandgroups 0x%04x\n", cbaf->host_band_groups);
 521
 522         result = usb_control_msg(
 523                 cbaf->usb_dev, usb_sndctrlpipe(cbaf->usb_dev, 0),
 524                 CBAF_REQ_SET_ASSOCIATION_RESPONSE,
 525                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 526                 0x0201, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
 527                 ccd, sizeof(*ccd), USB_CTRL_SET_TIMEOUT);
 528
 529         return result;
 530 }
 531
 532 static ssize_t cbaf_wusb_ck_store(struct device *dev,
 533                                   struct device_attribute *attr,
 534                                   const char *buf, size_t size)
 535 {
 536         ssize_t result;
 537         struct usb_interface *iface = to_usb_interface(dev);
 538         struct cbaf *cbaf = usb_get_intfdata(iface);
 539
 540         result = sscanf(buf,
 541                         "%02hhx %02hhx %02hhx %02hhx "
 542                         "%02hhx %02hhx %02hhx %02hhx "
 543                         "%02hhx %02hhx %02hhx %02hhx "
 544                         "%02hhx %02hhx %02hhx %02hhx",
 545                         &cbaf->ck.data[0] , &cbaf->ck.data[1],
 546                         &cbaf->ck.data[2] , &cbaf->ck.data[3],
 547                         &cbaf->ck.data[4] , &cbaf->ck.data[5],
 548                         &cbaf->ck.data[6] , &cbaf->ck.data[7],
 549                         &cbaf->ck.data[8] , &cbaf->ck.data[9],
 550                         &cbaf->ck.data[10], &cbaf->ck.data[11],
 551                         &cbaf->ck.data[12], &cbaf->ck.data[13],
 552                         &cbaf->ck.data[14], &cbaf->ck.data[15]);
 553         if (result != 16)
 554                 return -EINVAL;
 555
 556         result = cbaf_cc_upload(cbaf);
 557         if (result < 0)
 558                 return result;
 559
 560         return size;
 561 }
 562 static DEVICE_ATTR(wusb_ck, 0600, NULL, cbaf_wusb_ck_store);
 563
 564 static struct attribute *cbaf_dev_attrs[] = {
 565         &dev_attr_wusb_host_name.attr,
 566         &dev_attr_wusb_host_band_groups.attr,
 567         &dev_attr_wusb_chid.attr,
 568         &dev_attr_wusb_cdid.attr,
 569         &dev_attr_wusb_device_name.attr,
 570         &dev_attr_wusb_device_band_groups.attr,
 571         &dev_attr_wusb_ck.attr,
 572         NULL,
 573 };
 574
 575 static const struct attribute_group cbaf_dev_attr_group = {
 576         .name = NULL,   /* we want them in the same directory */
 577         .attrs = cbaf_dev_attrs,
 578 };
 579
 580 static int cbaf_probe(struct usb_interface *iface,
 581                       const struct usb_device_id *id)
 582 {
 583         struct cbaf *cbaf;
 584         struct device *dev = &iface->dev;
 585         int result = -ENOMEM;
 586
 587         cbaf = kzalloc(sizeof(*cbaf), GFP_KERNEL);
 588         if (cbaf == NULL)
 589                 goto error_kzalloc;
 590         cbaf->buffer = kmalloc(512, GFP_KERNEL);
 591         if (cbaf->buffer == NULL)
 592                 goto error_kmalloc_buffer;
 593
 594         cbaf->buffer_size = 512;
 595         cbaf->usb_dev = usb_get_dev(interface_to_usbdev(iface));
 596         cbaf->usb_iface = usb_get_intf(iface);
 597         result = cbaf_check(cbaf);
 598         if (result < 0) {
 599                 dev_err(dev, "This device is not WUSB-CBAF compliant and is not supported yet.\n");
 600                 goto error_check;
 601         }
 602
 603         result = sysfs_create_group(&dev->kobj, &cbaf_dev_attr_group);
 604         if (result < 0) {
 605                 dev_err(dev, "Can't register sysfs attr group: %d\n", result);
 606                 goto error_create_group;
 607         }
 608         usb_set_intfdata(iface, cbaf);
 609         return 0;
 610
 611 error_create_group:
 612 error_check:
 613         usb_put_intf(iface);
 614         usb_put_dev(cbaf->usb_dev);
 615         kfree(cbaf->buffer);
 616 error_kmalloc_buffer:
 617         kfree(cbaf);
 618 error_kzalloc:
 619         return result;
 620 }
 621
 622 static void cbaf_disconnect(struct usb_interface *iface)
 623 {
 624         struct cbaf *cbaf = usb_get_intfdata(iface);
 625         struct device *dev = &iface->dev;
 626         sysfs_remove_group(&dev->kobj, &cbaf_dev_attr_group);
 627         usb_set_intfdata(iface, NULL);
 628         usb_put_intf(iface);
 629         usb_put_dev(cbaf->usb_dev);
 630         kfree(cbaf->buffer);
 631         /* paranoia: clean up crypto keys */
 632         kzfree(cbaf);
 633 }
 634
 635 static const struct usb_device_id cbaf_id_table[] = {
 636         { USB_INTERFACE_INFO(0xef, 0x03, 0x01), },
 637         { },
 638 };
 639 MODULE_DEVICE_TABLE(usb, cbaf_id_table);
 640
 641 static struct usb_driver cbaf_driver = {
 642         .name =         "wusb-cbaf",
 643         .id_table =     cbaf_id_table,
 644         .probe =        cbaf_probe,
 645         .disconnect =   cbaf_disconnect,
 646 };
 647
 648 module_usb_driver(cbaf_driver);
 649
 650 MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
 651 MODULE_DESCRIPTION("Wireless USB Cable Based Association");
 652 MODULE_LICENSE("GPL");