git.oblomov.eu Git - linux-2.6/blob - drivers/usb/wusbcore/cbaf.c

   1 /*
   2  * Wireless USB - Cable Based Association
   3  *
   4  *
   5  * Copyright (C) 2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7  * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License version
  11  * 2 as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  21  * 02110-1301, USA.
  22  *
  23  *
  24  * WUSB devices have to be paired (associated in WUSB lingo) so
  25  * that they can connect to the system.
  26  *
  27  * One way of pairing is using CBA-Cable Based Association. First
  28  * time you plug the device with a cable, association is done between
  29  * host and device and subsequent times, you can connect wirelessly
  30  * without having to associate again. That's the idea.
  31  *
  32  * This driver does nothing Earth shattering. It just provides an
  33  * interface to chat with the wire-connected device so we can get a
  34  * CDID (device ID) that might have been previously associated to a
  35  * CHID (host ID) and to set up a new <CHID,CDID,CK> triplet
  36  * (connection context), with the CK being the secret, or connection
  37  * key. This is the pairing data.
  38  *
  39  * When a device with the CBA capability connects, the probe routine
  40  * just creates a bunch of sysfs files that a user space enumeration
  41  * manager uses to allow it to connect wirelessly to the system or not.
  42  *
  43  * The process goes like this:
  44  *
  45  * 1. Device plugs, cbaf is loaded, notifications happen.
  46  *
  47  * 2. The connection manager (CM) sees a device with CBAF capability
  48  *    (the wusb_chid etc. files in /sys/devices/blah/OURDEVICE).
  49  *
  50  * 3. The CM writes the host name, supported band groups, and the CHID
  51  *    (host ID) into the wusb_host_name, wusb_host_band_groups and
  52  *    wusb_chid files. These get sent to the device and the CDID (if
  53  *    any) for this host is requested.
  54  *
  55  * 4. The CM can verify that the device's supported band groups
  56  *    (wusb_device_band_groups) are compatible with the host.
  57  *
  58  * 5. The CM reads the wusb_cdid file.
  59  *
  60  * 6. The CM looks up its database
  61  *
  62  * 6.1 If it has a matching CHID,CDID entry, the device has been
  63  *     authorized before (paired) and nothing further needs to be
  64  *     done.
  65  *
  66  * 6.2 If the CDID is zero (or the CM doesn't find a matching CDID in
  67  *     its database), the device is assumed to be not known.  The CM
  68  *     may associate the host with device by: writing a randomly
  69  *     generated CDID to wusb_cdid and then a random CK to wusb_ck
  70  *     (this uploads the new CC to the device).
  71  *
  72  *     CMD may choose to prompt the user before associating with a new
  73  *     device.
  74  *
  75  * 7. Device is unplugged.
  76  *
  77  * When the device tries to connect wirelessly, it will present its
  78  * CDID to the WUSB host controller.  The CM will query the
  79  * database. If the CHID/CDID pair found, it will (with a 4-way
  80  * handshake) challenge the device to demonstrate it has the CK secret
  81  * key (from our database) without actually exchanging it. Once
  82  * satisfied, crypto keys are derived from the CK, the device is
  83  * connected and all communication is encrypted.
  84  *
  85  * References:
  86  *   [WUSB-AM] Association Models Supplement to the Certified Wireless
  87  *             Universal Serial Bus Specification, version 1.0.
  88  */
  89 #include <linux/module.h>
  90 #include <linux/ctype.h>
  91 #include <linux/usb.h>
  92 #include <linux/interrupt.h>
  93 #include <linux/delay.h>
  94 #include <linux/random.h>
  95 #include <linux/mutex.h>
  96 #include <linux/uwb.h>
  97 #include <linux/usb/wusb.h>
  98 #include <linux/usb/association.h>
  99
 100 #define CBA_NAME_LEN 0x40 /* [WUSB-AM] table 4-7 */
 101
 102 /* An instance of a Cable-Based-Association-Framework device */
 103 struct cbaf {
 104         struct usb_device *usb_dev;
 105         struct usb_interface *usb_iface;
 106         void *buffer;
 107         size_t buffer_size;
 108
 109         struct wusb_ckhdid chid;
 110         char host_name[CBA_NAME_LEN];
 111         u16 host_band_groups;
 112
 113         struct wusb_ckhdid cdid;
 114         char device_name[CBA_NAME_LEN];
 115         u16 device_band_groups;
 116
 117         struct wusb_ckhdid ck;
 118 };
 119
 120 /*
 121  * Verify that a CBAF USB-interface has what we need
 122  *
 123  * According to [WUSB-AM], CBA devices should provide at least two
 124  * interfaces:
 125  *  - RETRIEVE_HOST_INFO
 126  *  - ASSOCIATE
 127  *
 128  * If the device doesn't provide these interfaces, we do not know how
 129  * to deal with it.
 130  */
 131 static int cbaf_check(struct cbaf *cbaf)
 132 {
 133         int result;
 134         struct device *dev = &cbaf->usb_iface->dev;
 135         struct wusb_cbaf_assoc_info *assoc_info;
 136         struct wusb_cbaf_assoc_request *assoc_request;
 137         size_t assoc_size;
 138         void *itr, *top;
 139         int ar_rhi = 0, ar_assoc = 0;
 140
 141         result = usb_control_msg(
 142                 cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
 143                 CBAF_REQ_GET_ASSOCIATION_INFORMATION,
 144                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 145                 0, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
 146                 cbaf->buffer, cbaf->buffer_size, 1000 /* FIXME: arbitrary */);
 147         if (result < 0) {
 148                 dev_err(dev, "Cannot get available association types: %d\n",
 149                         result);
 150                 return result;
 151         }
 152
 153         assoc_info = cbaf->buffer;
 154         if (result < sizeof(*assoc_info)) {
 155                 dev_err(dev, "Not enough data to decode association info "
 156                         "header (%zu vs %zu bytes required)\n",
 157                         (size_t)result, sizeof(*assoc_info));
 158                 return result;
 159         }
 160
 161         assoc_size = le16_to_cpu(assoc_info->Length);
 162         if (result < assoc_size) {
 163                 dev_err(dev, "Not enough data to decode association info "
 164                         "(%zu vs %zu bytes required)\n",
 165                         (size_t)assoc_size, sizeof(*assoc_info));
 166                 return result;
 167         }
 168         /*
 169          * From now on, we just verify, but won't error out unless we
 170          * don't find the AR_TYPE_WUSB_{RETRIEVE_HOST_INFO,ASSOCIATE}
 171          * types.
 172          */
 173         itr = cbaf->buffer + sizeof(*assoc_info);
 174         top = cbaf->buffer + assoc_size;
 175         dev_dbg(dev, "Found %u association requests (%zu bytes)\n",
 176                  assoc_info->NumAssociationRequests, assoc_size);
 177
 178         while (itr < top) {
 179                 u16 ar_type, ar_subtype;
 180                 u32 ar_size;
 181                 const char *ar_name;
 182
 183                 assoc_request = itr;
 184
 185                 if (top - itr < sizeof(*assoc_request)) {
 186                         dev_err(dev, "Not enough data to decode associaton "
 187                                 "request (%zu vs %zu bytes needed)\n",
 188                                 top - itr, sizeof(*assoc_request));
 189                         break;
 190                 }
 191
 192                 ar_type = le16_to_cpu(assoc_request->AssociationTypeId);
 193                 ar_subtype = le16_to_cpu(assoc_request->AssociationSubTypeId);
 194                 ar_size = le32_to_cpu(assoc_request->AssociationTypeInfoSize);
 195                 ar_name = "unknown";
 196
 197                 switch (ar_type) {
 198                 case AR_TYPE_WUSB:
 199                         /* Verify we have what is mandated by [WUSB-AM]. */
 200                         switch (ar_subtype) {
 201                         case AR_TYPE_WUSB_RETRIEVE_HOST_INFO:
 202                                 ar_name = "RETRIEVE_HOST_INFO";
 203                                 ar_rhi = 1;
 204                                 break;
 205                         case AR_TYPE_WUSB_ASSOCIATE:
 206                                 /* send assoc data */
 207                                 ar_name = "ASSOCIATE";
 208                                 ar_assoc = 1;
 209                                 break;
 210                         };
 211                         break;
 212                 };
 213
 214                 dev_dbg(dev, "Association request #%02u: 0x%04x/%04x "
 215                          "(%zu bytes): %s\n",
 216                          assoc_request->AssociationDataIndex, ar_type,
 217                          ar_subtype, (size_t)ar_size, ar_name);
 218
 219                 itr += sizeof(*assoc_request);
 220         }
 221
 222         if (!ar_rhi) {
 223                 dev_err(dev, "Missing RETRIEVE_HOST_INFO association "
 224                         "request\n");
 225                 return -EINVAL;
 226         }
 227         if (!ar_assoc) {
 228                 dev_err(dev, "Missing ASSOCIATE association request\n");
 229                 return -EINVAL;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static const struct wusb_cbaf_host_info cbaf_host_info_defaults = {
 236         .AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
 237         .AssociationTypeId        = cpu_to_le16(AR_TYPE_WUSB),
 238         .AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
 239         .AssociationSubTypeId = cpu_to_le16(AR_TYPE_WUSB_RETRIEVE_HOST_INFO),
 240         .CHID_hdr                 = WUSB_AR_CHID,
 241         .LangID_hdr               = WUSB_AR_LangID,
 242         .HostFriendlyName_hdr     = WUSB_AR_HostFriendlyName,
 243 };
 244
 245 /* Send WUSB host information (CHID and name) to a CBAF device */
 246 static int cbaf_send_host_info(struct cbaf *cbaf)
 247 {
 248         struct wusb_cbaf_host_info *hi;
 249         size_t name_len;
 250         size_t hi_size;
 251
 252         hi = cbaf->buffer;
 253         memset(hi, 0, sizeof(*hi));
 254         *hi = cbaf_host_info_defaults;
 255         hi->CHID = cbaf->chid;
 256         hi->LangID = 0; /* FIXME: I guess... */
 257         strlcpy(hi->HostFriendlyName, cbaf->host_name, CBA_NAME_LEN);
 258         name_len = strlen(cbaf->host_name);
 259         hi->HostFriendlyName_hdr.len = cpu_to_le16(name_len);
 260         hi_size = sizeof(*hi) + name_len;
 261
 262         return usb_control_msg(cbaf->usb_dev, usb_sndctrlpipe(cbaf->usb_dev, 0),
 263                         CBAF_REQ_SET_ASSOCIATION_RESPONSE,
 264                         USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 265                         0x0101,
 266                         cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
 267                         hi, hi_size, 1000 /* FIXME: arbitrary */);
 268 }
 269
 270 /*
 271  * Get device's information (CDID) associated to CHID
 272  *
 273  * The device will return it's information (CDID, name, bandgroups)
 274  * associated to the CHID we have set before, or 0 CDID and default
 275  * name and bandgroup if no CHID set or unknown.
 276  */
 277 static int cbaf_cdid_get(struct cbaf *cbaf)
 278 {
 279         int result;
 280         struct device *dev = &cbaf->usb_iface->dev;
 281         struct wusb_cbaf_device_info *di;
 282         size_t needed;
 283
 284         di = cbaf->buffer;
 285         result = usb_control_msg(
 286                 cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
 287                 CBAF_REQ_GET_ASSOCIATION_REQUEST,
 288                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 289                 0x0200, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
 290                 di, cbaf->buffer_size, 1000 /* FIXME: arbitrary */);
 291         if (result < 0) {
 292                 dev_err(dev, "Cannot request device information: %d\n", result);
 293                 return result;
 294         }
 295
 296         needed = result < sizeof(*di) ? sizeof(*di) : le32_to_cpu(di->Length);
 297         if (result < needed) {
 298                 dev_err(dev, "Not enough data in DEVICE_INFO reply (%zu vs "
 299                         "%zu bytes needed)\n", (size_t)result, needed);
 300                 return result;
 301         }
 302
 303         strlcpy(cbaf->device_name, di->DeviceFriendlyName, CBA_NAME_LEN);
 304         cbaf->cdid = di->CDID;
 305         cbaf->device_band_groups = le16_to_cpu(di->BandGroups);
 306
 307         return 0;
 308 }
 309
 310 static ssize_t cbaf_wusb_chid_show(struct device *dev,
 311                                         struct device_attribute *attr,
 312                                         char *buf)
 313 {
 314         struct usb_interface *iface = to_usb_interface(dev);
 315         struct cbaf *cbaf = usb_get_intfdata(iface);
 316         char pr_chid[WUSB_CKHDID_STRSIZE];
 317
 318         ckhdid_printf(pr_chid, sizeof(pr_chid), &cbaf->chid);
 319         return scnprintf(buf, PAGE_SIZE, "%s\n", pr_chid);
 320 }
 321
 322 static ssize_t cbaf_wusb_chid_store(struct device *dev,
 323                                          struct device_attribute *attr,
 324                                          const char *buf, size_t size)
 325 {
 326         ssize_t result;
 327         struct usb_interface *iface = to_usb_interface(dev);
 328         struct cbaf *cbaf = usb_get_intfdata(iface);
 329
 330         result = sscanf(buf,
 331                         "%02hhx %02hhx %02hhx %02hhx "
 332                         "%02hhx %02hhx %02hhx %02hhx "
 333                         "%02hhx %02hhx %02hhx %02hhx "
 334                         "%02hhx %02hhx %02hhx %02hhx",
 335                         &cbaf->chid.data[0] , &cbaf->chid.data[1],
 336                         &cbaf->chid.data[2] , &cbaf->chid.data[3],
 337                         &cbaf->chid.data[4] , &cbaf->chid.data[5],
 338                         &cbaf->chid.data[6] , &cbaf->chid.data[7],
 339                         &cbaf->chid.data[8] , &cbaf->chid.data[9],
 340                         &cbaf->chid.data[10], &cbaf->chid.data[11],
 341                         &cbaf->chid.data[12], &cbaf->chid.data[13],
 342                         &cbaf->chid.data[14], &cbaf->chid.data[15]);
 343
 344         if (result != 16)
 345                 return -EINVAL;
 346
 347         result = cbaf_send_host_info(cbaf);
 348         if (result < 0)
 349                 return result;
 350         result = cbaf_cdid_get(cbaf);
 351         if (result < 0)
 352                 return -result;
 353         return size;
 354 }
 355 static DEVICE_ATTR(wusb_chid, 0600, cbaf_wusb_chid_show, cbaf_wusb_chid_store);
 356
 357 static ssize_t cbaf_wusb_host_name_show(struct device *dev,
 358                                         struct device_attribute *attr,
 359                                         char *buf)
 360 {
 361         struct usb_interface *iface = to_usb_interface(dev);
 362         struct cbaf *cbaf = usb_get_intfdata(iface);
 363
 364         return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->host_name);
 365 }
 366
 367 static ssize_t cbaf_wusb_host_name_store(struct device *dev,
 368                                          struct device_attribute *attr,
 369                                          const char *buf, size_t size)
 370 {
 371         ssize_t result;
 372         struct usb_interface *iface = to_usb_interface(dev);
 373         struct cbaf *cbaf = usb_get_intfdata(iface);
 374
 375         result = sscanf(buf, "%63s", cbaf->host_name);
 376         if (result != 1)
 377                 return -EINVAL;
 378
 379         return size;
 380 }
 381 static DEVICE_ATTR(wusb_host_name, 0600, cbaf_wusb_host_name_show,
 382                                          cbaf_wusb_host_name_store);
 383
 384 static ssize_t cbaf_wusb_host_band_groups_show(struct device *dev,
 385                                                struct device_attribute *attr,
 386                                                char *buf)
 387 {
 388         struct usb_interface *iface = to_usb_interface(dev);
 389         struct cbaf *cbaf = usb_get_intfdata(iface);
 390
 391         return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->host_band_groups);
 392 }
 393
 394 static ssize_t cbaf_wusb_host_band_groups_store(struct device *dev,
 395                                                 struct device_attribute *attr,
 396                                                 const char *buf, size_t size)
 397 {
 398         ssize_t result;
 399         struct usb_interface *iface = to_usb_interface(dev);
 400         struct cbaf *cbaf = usb_get_intfdata(iface);
 401         u16 band_groups = 0;
 402
 403         result = sscanf(buf, "%04hx", &band_groups);
 404         if (result != 1)
 405                 return -EINVAL;
 406
 407         cbaf->host_band_groups = band_groups;
 408
 409         return size;
 410 }
 411
 412 static DEVICE_ATTR(wusb_host_band_groups, 0600,
 413                    cbaf_wusb_host_band_groups_show,
 414                    cbaf_wusb_host_band_groups_store);
 415
 416 static const struct wusb_cbaf_device_info cbaf_device_info_defaults = {
 417         .Length_hdr               = WUSB_AR_Length,
 418         .CDID_hdr                 = WUSB_AR_CDID,
 419         .BandGroups_hdr           = WUSB_AR_BandGroups,
 420         .LangID_hdr               = WUSB_AR_LangID,
 421         .DeviceFriendlyName_hdr   = WUSB_AR_DeviceFriendlyName,
 422 };
 423
 424 static ssize_t cbaf_wusb_cdid_show(struct device *dev,
 425                                    struct device_attribute *attr, char *buf)
 426 {
 427         struct usb_interface *iface = to_usb_interface(dev);
 428         struct cbaf *cbaf = usb_get_intfdata(iface);
 429         char pr_cdid[WUSB_CKHDID_STRSIZE];
 430
 431         ckhdid_printf(pr_cdid, sizeof(pr_cdid), &cbaf->cdid);
 432         return scnprintf(buf, PAGE_SIZE, "%s\n", pr_cdid);
 433 }
 434
 435 static ssize_t cbaf_wusb_cdid_store(struct device *dev,
 436                                 struct device_attribute *attr,
 437                                 const char *buf, size_t size)
 438 {
 439         ssize_t result;
 440         struct usb_interface *iface = to_usb_interface(dev);
 441         struct cbaf *cbaf = usb_get_intfdata(iface);
 442         struct wusb_ckhdid cdid;
 443
 444         result = sscanf(buf,
 445                         "%02hhx %02hhx %02hhx %02hhx "
 446                         "%02hhx %02hhx %02hhx %02hhx "
 447                         "%02hhx %02hhx %02hhx %02hhx "
 448                         "%02hhx %02hhx %02hhx %02hhx",
 449                         &cdid.data[0] , &cdid.data[1],
 450                         &cdid.data[2] , &cdid.data[3],
 451                         &cdid.data[4] , &cdid.data[5],
 452                         &cdid.data[6] , &cdid.data[7],
 453                         &cdid.data[8] , &cdid.data[9],
 454                         &cdid.data[10], &cdid.data[11],
 455                         &cdid.data[12], &cdid.data[13],
 456                         &cdid.data[14], &cdid.data[15]);
 457         if (result != 16)
 458                 return -EINVAL;
 459
 460         cbaf->cdid = cdid;
 461
 462         return size;
 463 }
 464 static DEVICE_ATTR(wusb_cdid, 0600, cbaf_wusb_cdid_show, cbaf_wusb_cdid_store);
 465
 466 static ssize_t cbaf_wusb_device_band_groups_show(struct device *dev,
 467                                                  struct device_attribute *attr,
 468                                                  char *buf)
 469 {
 470         struct usb_interface *iface = to_usb_interface(dev);
 471         struct cbaf *cbaf = usb_get_intfdata(iface);
 472
 473         return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->device_band_groups);
 474 }
 475
 476 static DEVICE_ATTR(wusb_device_band_groups, 0600,
 477                    cbaf_wusb_device_band_groups_show,
 478                    NULL);
 479
 480 static ssize_t cbaf_wusb_device_name_show(struct device *dev,
 481                                         struct device_attribute *attr,
 482                                         char *buf)
 483 {
 484         struct usb_interface *iface = to_usb_interface(dev);
 485         struct cbaf *cbaf = usb_get_intfdata(iface);
 486
 487         return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->device_name);
 488 }
 489 static DEVICE_ATTR(wusb_device_name, 0600, cbaf_wusb_device_name_show, NULL);
 490
 491 static const struct wusb_cbaf_cc_data cbaf_cc_data_defaults = {
 492         .AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
 493         .AssociationTypeId        = cpu_to_le16(AR_TYPE_WUSB),
 494         .AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
 495         .AssociationSubTypeId     = cpu_to_le16(AR_TYPE_WUSB_ASSOCIATE),
 496         .Length_hdr               = WUSB_AR_Length,
 497         .Length                   = cpu_to_le32(sizeof(struct wusb_cbaf_cc_data)),
 498         .ConnectionContext_hdr    = WUSB_AR_ConnectionContext,
 499         .BandGroups_hdr           = WUSB_AR_BandGroups,
 500 };
 501
 502 static const struct wusb_cbaf_cc_data_fail cbaf_cc_data_fail_defaults = {
 503         .AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
 504         .AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
 505         .Length_hdr               = WUSB_AR_Length,
 506         .AssociationStatus_hdr    = WUSB_AR_AssociationStatus,
 507 };
 508
 509 /*
 510  * Send a new CC to the device.
 511  */
 512 static int cbaf_cc_upload(struct cbaf *cbaf)
 513 {
 514         int result;
 515         struct device *dev = &cbaf->usb_iface->dev;
 516         struct wusb_cbaf_cc_data *ccd;
 517         char pr_cdid[WUSB_CKHDID_STRSIZE];
 518
 519         ccd =  cbaf->buffer;
 520         *ccd = cbaf_cc_data_defaults;
 521         ccd->CHID = cbaf->chid;
 522         ccd->CDID = cbaf->cdid;
 523         ccd->CK = cbaf->ck;
 524         ccd->BandGroups = cpu_to_le16(cbaf->host_band_groups);
 525
 526         dev_dbg(dev, "Trying to upload CC:\n");
 527         ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CHID);
 528         dev_dbg(dev, "  CHID       %s\n", pr_cdid);
 529         ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CDID);
 530         dev_dbg(dev, "  CDID       %s\n", pr_cdid);
 531         dev_dbg(dev, "  Bandgroups 0x%04x\n", cbaf->host_band_groups);
 532
 533         result = usb_control_msg(
 534                 cbaf->usb_dev, usb_sndctrlpipe(cbaf->usb_dev, 0),
 535                 CBAF_REQ_SET_ASSOCIATION_RESPONSE,
 536                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 537                 0x0201, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
 538                 ccd, sizeof(*ccd), 1000 /* FIXME: arbitrary */);
 539
 540         return result;
 541 }
 542
 543 static ssize_t cbaf_wusb_ck_store(struct device *dev,
 544                                   struct device_attribute *attr,
 545                                   const char *buf, size_t size)
 546 {
 547         ssize_t result;
 548         struct usb_interface *iface = to_usb_interface(dev);
 549         struct cbaf *cbaf = usb_get_intfdata(iface);
 550
 551         result = sscanf(buf,
 552                         "%02hhx %02hhx %02hhx %02hhx "
 553                         "%02hhx %02hhx %02hhx %02hhx "
 554                         "%02hhx %02hhx %02hhx %02hhx "
 555                         "%02hhx %02hhx %02hhx %02hhx",
 556                         &cbaf->ck.data[0] , &cbaf->ck.data[1],
 557                         &cbaf->ck.data[2] , &cbaf->ck.data[3],
 558                         &cbaf->ck.data[4] , &cbaf->ck.data[5],
 559                         &cbaf->ck.data[6] , &cbaf->ck.data[7],
 560                         &cbaf->ck.data[8] , &cbaf->ck.data[9],
 561                         &cbaf->ck.data[10], &cbaf->ck.data[11],
 562                         &cbaf->ck.data[12], &cbaf->ck.data[13],
 563                         &cbaf->ck.data[14], &cbaf->ck.data[15]);
 564         if (result != 16)
 565                 return -EINVAL;
 566
 567         result = cbaf_cc_upload(cbaf);
 568         if (result < 0)
 569                 return result;
 570
 571         return size;
 572 }
 573 static DEVICE_ATTR(wusb_ck, 0600, NULL, cbaf_wusb_ck_store);
 574
 575 static struct attribute *cbaf_dev_attrs[] = {
 576         &dev_attr_wusb_host_name.attr,
 577         &dev_attr_wusb_host_band_groups.attr,
 578         &dev_attr_wusb_chid.attr,
 579         &dev_attr_wusb_cdid.attr,
 580         &dev_attr_wusb_device_name.attr,
 581         &dev_attr_wusb_device_band_groups.attr,
 582         &dev_attr_wusb_ck.attr,
 583         NULL,
 584 };
 585
 586 static struct attribute_group cbaf_dev_attr_group = {
 587         .name = NULL,   /* we want them in the same directory */
 588         .attrs = cbaf_dev_attrs,
 589 };
 590
 591 static int cbaf_probe(struct usb_interface *iface,
 592                       const struct usb_device_id *id)
 593 {
 594         struct cbaf *cbaf;
 595         struct device *dev = &iface->dev;
 596         int result = -ENOMEM;
 597
 598         cbaf = kzalloc(sizeof(*cbaf), GFP_KERNEL);
 599         if (cbaf == NULL)
 600                 goto error_kzalloc;
 601         cbaf->buffer = kmalloc(512, GFP_KERNEL);
 602         if (cbaf->buffer == NULL)
 603                 goto error_kmalloc_buffer;
 604
 605         cbaf->buffer_size = 512;
 606         cbaf->usb_dev = usb_get_dev(interface_to_usbdev(iface));
 607         cbaf->usb_iface = usb_get_intf(iface);
 608         result = cbaf_check(cbaf);
 609         if (result < 0) {
 610                 dev_err(dev, "This device is not WUSB-CBAF compliant"
 611                         "and is not supported yet.\n");
 612                 goto error_check;
 613         }
 614
 615         result = sysfs_create_group(&dev->kobj, &cbaf_dev_attr_group);
 616         if (result < 0) {
 617                 dev_err(dev, "Can't register sysfs attr group: %d\n", result);
 618                 goto error_create_group;
 619         }
 620         usb_set_intfdata(iface, cbaf);
 621         return 0;
 622
 623 error_create_group:
 624 error_check:
 625         kfree(cbaf->buffer);
 626 error_kmalloc_buffer:
 627         kfree(cbaf);
 628 error_kzalloc:
 629         return result;
 630 }
 631
 632 static void cbaf_disconnect(struct usb_interface *iface)
 633 {
 634         struct cbaf *cbaf = usb_get_intfdata(iface);
 635         struct device *dev = &iface->dev;
 636         sysfs_remove_group(&dev->kobj, &cbaf_dev_attr_group);
 637         usb_set_intfdata(iface, NULL);
 638         usb_put_intf(iface);
 639         kfree(cbaf->buffer);
 640         /* paranoia: clean up crypto keys */
 641         memset(cbaf, 0, sizeof(*cbaf));
 642         kfree(cbaf);
 643 }
 644
 645 static struct usb_device_id cbaf_id_table[] = {
 646         { USB_INTERFACE_INFO(0xef, 0x03, 0x01), },
 647         { },
 648 };
 649 MODULE_DEVICE_TABLE(usb, cbaf_id_table);
 650
 651 static struct usb_driver cbaf_driver = {
 652         .name =         "wusb-cbaf",
 653         .id_table =     cbaf_id_table,
 654         .probe =        cbaf_probe,
 655         .disconnect =   cbaf_disconnect,
 656 };
 657
 658 static int __init cbaf_driver_init(void)
 659 {
 660         return usb_register(&cbaf_driver);
 661 }
 662 module_init(cbaf_driver_init);
 663
 664 static void __exit cbaf_driver_exit(void)
 665 {
 666         usb_deregister(&cbaf_driver);
 667 }
 668 module_exit(cbaf_driver_exit);
 669
 670 MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
 671 MODULE_DESCRIPTION("Wireless USB Cable Based Association");
 672 MODULE_LICENSE("GPL");