drivers/usb/wusbcore/security.c

   1 /*
   2  * Wireless USB Host Controller
   3  * Security support: encryption enablement, etc
   4  *
   5  * Copyright (C) 2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301, USA.
  21  *
  22  *
  23  * FIXME: docs
  24  */
  25 #include <linux/types.h>
  26 #include <linux/usb/ch9.h>
  27 #include <linux/random.h>
  28 #include "wusbhc.h"
  29
  30 static void wusbhc_set_gtk_callback(struct urb *urb);
  31 static void wusbhc_gtk_rekey_done_work(struct work_struct *work);
  32
  33 int wusbhc_sec_create(struct wusbhc *wusbhc)
  34 {
  35         wusbhc->gtk.descr.bLength = sizeof(wusbhc->gtk.descr) + sizeof(wusbhc->gtk.data);
  36         wusbhc->gtk.descr.bDescriptorType = USB_DT_KEY;
  37         wusbhc->gtk.descr.bReserved = 0;
  38
  39         wusbhc->gtk_index = wusb_key_index(0, WUSB_KEY_INDEX_TYPE_GTK,
  40                                            WUSB_KEY_INDEX_ORIGINATOR_HOST);
  41
  42         INIT_WORK(&wusbhc->gtk_rekey_done_work, wusbhc_gtk_rekey_done_work);
  43
  44         return 0;
  45 }
  46
  47
  48 /* Called when the HC is destroyed */
  49 void wusbhc_sec_destroy(struct wusbhc *wusbhc)
  50 {
  51 }
  52
  53
  54 /**
  55  * wusbhc_next_tkid - generate a new, currently unused, TKID
  56  * @wusbhc:   the WUSB host controller
  57  * @wusb_dev: the device whose PTK the TKID is for
  58  *            (or NULL for a TKID for a GTK)
  59  *
  60  * The generated TKID consist of two parts: the device's authenicated
  61  * address (or 0 or a GTK); and an incrementing number.  This ensures
  62  * that TKIDs cannot be shared between devices and by the time the
  63  * incrementing number wraps around the older TKIDs will no longer be
  64  * in use (a maximum of two keys may be active at any one time).
  65  */
  66 static u32 wusbhc_next_tkid(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
  67 {
  68         u32 *tkid;
  69         u32 addr;
  70
  71         if (wusb_dev == NULL) {
  72                 tkid = &wusbhc->gtk_tkid;
  73                 addr = 0;
  74         } else {
  75                 tkid = &wusb_port_by_idx(wusbhc, wusb_dev->port_idx)->ptk_tkid;
  76                 addr = wusb_dev->addr & 0x7f;
  77         }
  78
  79         *tkid = (addr << 8) | ((*tkid + 1) & 0xff);
  80
  81         return *tkid;
  82 }
  83
  84 static void wusbhc_generate_gtk(struct wusbhc *wusbhc)
  85 {
  86         const size_t key_size = sizeof(wusbhc->gtk.data);
  87         u32 tkid;
  88
  89         tkid = wusbhc_next_tkid(wusbhc, NULL);
  90
  91         wusbhc->gtk.descr.tTKID[0] = (tkid >>  0) & 0xff;
  92         wusbhc->gtk.descr.tTKID[1] = (tkid >>  8) & 0xff;
  93         wusbhc->gtk.descr.tTKID[2] = (tkid >> 16) & 0xff;
  94
  95         get_random_bytes(wusbhc->gtk.descr.bKeyData, key_size);
  96 }
  97
  98 /**
  99  * wusbhc_sec_start - start the security management process
 100  * @wusbhc: the WUSB host controller
 101  *
 102  * Generate and set an initial GTK on the host controller.
 103  *
 104  * Called when the HC is started.
 105  */
 106 int wusbhc_sec_start(struct wusbhc *wusbhc)
 107 {
 108         const size_t key_size = sizeof(wusbhc->gtk.data);
 109         int result;
 110
 111         wusbhc_generate_gtk(wusbhc);
 112
 113         result = wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid,
 114                                  &wusbhc->gtk.descr.bKeyData, key_size);
 115         if (result < 0)
 116                 dev_err(wusbhc->dev, "cannot set GTK for the host: %d\n",
 117                         result);
 118
 119         return result;
 120 }
 121
 122 /**
 123  * wusbhc_sec_stop - stop the security management process
 124  * @wusbhc: the WUSB host controller
 125  *
 126  * Wait for any pending GTK rekeys to stop.
 127  */
 128 void wusbhc_sec_stop(struct wusbhc *wusbhc)
 129 {
 130         cancel_work_sync(&wusbhc->gtk_rekey_done_work);
 131 }
 132
 133
 134 /** @returns encryption type name */
 135 const char *wusb_et_name(u8 x)
 136 {
 137         switch (x) {
 138         case USB_ENC_TYPE_UNSECURE:     return "unsecure";
 139         case USB_ENC_TYPE_WIRED:        return "wired";
 140         case USB_ENC_TYPE_CCM_1:        return "CCM-1";
 141         case USB_ENC_TYPE_RSA_1:        return "RSA-1";
 142         default:                        return "unknown";
 143         }
 144 }
 145 EXPORT_SYMBOL_GPL(wusb_et_name);
 146
 147 /*
 148  * Set the device encryption method
 149  *
 150  * We tell the device which encryption method to use; we do this when
 151  * setting up the device's security.
 152  */
 153 static int wusb_dev_set_encryption(struct usb_device *usb_dev, int value)
 154 {
 155         int result;
 156         struct device *dev = &usb_dev->dev;
 157         struct wusb_dev *wusb_dev = usb_dev->wusb_dev;
 158
 159         if (value) {
 160                 value = wusb_dev->ccm1_etd.bEncryptionValue;
 161         } else {
 162                 /* FIXME: should be wusb_dev->etd[UNSECURE].bEncryptionValue */
 163                 value = 0;
 164         }
 165         /* Set device's */
 166         result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
 167                         USB_REQ_SET_ENCRYPTION,
 168                         USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 169                         value, 0, NULL, 0, 1000 /* FIXME: arbitrary */);
 170         if (result < 0)
 171                 dev_err(dev, "Can't set device's WUSB encryption to "
 172                         "%s (value %d): %d\n",
 173                         wusb_et_name(wusb_dev->ccm1_etd.bEncryptionType),
 174                         wusb_dev->ccm1_etd.bEncryptionValue,  result);
 175         return result;
 176 }
 177
 178 /*
 179  * Set the GTK to be used by a device.
 180  *
 181  * The device must be authenticated.
 182  */
 183 static int wusb_dev_set_gtk(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
 184 {
 185         struct usb_device *usb_dev = wusb_dev->usb_dev;
 186
 187         return usb_control_msg(
 188                 usb_dev, usb_sndctrlpipe(usb_dev, 0),
 189                 USB_REQ_SET_DESCRIPTOR,
 190                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 191                 USB_DT_KEY << 8 | wusbhc->gtk_index, 0,
 192                 &wusbhc->gtk.descr, wusbhc->gtk.descr.bLength,
 193                 1000);
 194 }
 195
 196
 197 /* FIXME: prototype for adding security */
 198 int wusb_dev_sec_add(struct wusbhc *wusbhc,
 199                      struct usb_device *usb_dev, struct wusb_dev *wusb_dev)
 200 {
 201         int result, bytes, secd_size;
 202         struct device *dev = &usb_dev->dev;
 203         struct usb_security_descriptor secd;
 204         const struct usb_encryption_descriptor *etd, *ccm1_etd = NULL;
 205         void *secd_buf;
 206         const void *itr, *top;
 207         char buf[64];
 208
 209         result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
 210                                     0, &secd, sizeof(secd));
 211         if (result < sizeof(secd)) {
 212                 dev_err(dev, "Can't read security descriptor or "
 213                         "not enough data: %d\n", result);
 214                 goto error_secd;
 215         }
 216         secd_size = le16_to_cpu(secd.wTotalLength);
 217         secd_buf = kmalloc(secd_size, GFP_KERNEL);
 218         if (secd_buf == NULL) {
 219                 dev_err(dev, "Can't allocate space for security descriptors\n");
 220                 goto error_secd_alloc;
 221         }
 222         result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
 223                                     0, secd_buf, secd_size);
 224         if (result < secd_size) {
 225                 dev_err(dev, "Can't read security descriptor or "
 226                         "not enough data: %d\n", result);
 227                 goto error_secd_all;
 228         }
 229         bytes = 0;
 230         itr = secd_buf + sizeof(secd);
 231         top = secd_buf + result;
 232         while (itr < top) {
 233                 etd = itr;
 234                 if (top - itr < sizeof(*etd)) {
 235                         dev_err(dev, "BUG: bad device security descriptor; "
 236                                 "not enough data (%zu vs %zu bytes left)\n",
 237                                 top - itr, sizeof(*etd));
 238                         break;
 239                 }
 240                 if (etd->bLength < sizeof(*etd)) {
 241                         dev_err(dev, "BUG: bad device encryption descriptor; "
 242                                 "descriptor is too short "
 243                                 "(%u vs %zu needed)\n",
 244                                 etd->bLength, sizeof(*etd));
 245                         break;
 246                 }
 247                 itr += etd->bLength;
 248                 bytes += snprintf(buf + bytes, sizeof(buf) - bytes,
 249                                   "%s (0x%02x/%02x) ",
 250                                   wusb_et_name(etd->bEncryptionType),
 251                                   etd->bEncryptionValue, etd->bAuthKeyIndex);
 252                 if (etd->bEncryptionType == USB_ENC_TYPE_CCM_1)
 253                         ccm1_etd = etd;
 254         }
 255         /* This code only supports CCM1 as of now. */
 256         /* FIXME: user has to choose which sec mode to use?
 257          * In theory we want CCM */
 258         if (ccm1_etd == NULL) {
 259                 dev_err(dev, "WUSB device doesn't support CCM1 encryption, "
 260                         "can't use!\n");
 261                 result = -EINVAL;
 262                 goto error_no_ccm1;
 263         }
 264         wusb_dev->ccm1_etd = *ccm1_etd;
 265         dev_dbg(dev, "supported encryption: %s; using %s (0x%02x/%02x)\n",
 266                 buf, wusb_et_name(ccm1_etd->bEncryptionType),
 267                 ccm1_etd->bEncryptionValue, ccm1_etd->bAuthKeyIndex);
 268         result = 0;
 269         kfree(secd_buf);
 270 out:
 271         return result;
 272
 273
 274 error_no_ccm1:
 275 error_secd_all:
 276         kfree(secd_buf);
 277 error_secd_alloc:
 278 error_secd:
 279         goto out;
 280 }
 281
 282 void wusb_dev_sec_rm(struct wusb_dev *wusb_dev)
 283 {
 284         /* Nothing so far */
 285 }
 286
 287 /**
 288  * Update the address of an unauthenticated WUSB device
 289  *
 290  * Once we have successfully authenticated, we take it to addr0 state
 291  * and then to a normal address.
 292  *
 293  * Before the device's address (as known by it) was usb_dev->devnum |
 294  * 0x80 (unauthenticated address). With this we update it to usb_dev->devnum.
 295  */
 296 int wusb_dev_update_address(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev)
 297 {
 298         int result = -ENOMEM;
 299         struct usb_device *usb_dev = wusb_dev->usb_dev;
 300         struct device *dev = &usb_dev->dev;
 301         u8 new_address = wusb_dev->addr & 0x7F;
 302
 303         /* Set address 0 */
 304         result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
 305                                  USB_REQ_SET_ADDRESS, 0,
 306                                  0, 0, NULL, 0, 1000 /* FIXME: arbitrary */);
 307         if (result < 0) {
 308                 dev_err(dev, "auth failed: can't set address 0: %d\n",
 309                         result);
 310                 goto error_addr0;
 311         }
 312         result = wusb_set_dev_addr(wusbhc, wusb_dev, 0);
 313         if (result < 0)
 314                 goto error_addr0;
 315         usb_set_device_state(usb_dev, USB_STATE_DEFAULT);
 316         usb_ep0_reinit(usb_dev);
 317
 318         /* Set new (authenticated) address. */
 319         result = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
 320                                  USB_REQ_SET_ADDRESS, 0,
 321                                  new_address, 0, NULL, 0,
 322                                  1000 /* FIXME: arbitrary */);
 323         if (result < 0) {
 324                 dev_err(dev, "auth failed: can't set address %u: %d\n",
 325                         new_address, result);
 326                 goto error_addr;
 327         }
 328         result = wusb_set_dev_addr(wusbhc, wusb_dev, new_address);
 329         if (result < 0)
 330                 goto error_addr;
 331         usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
 332         usb_ep0_reinit(usb_dev);
 333         usb_dev->authenticated = 1;
 334 error_addr:
 335 error_addr0:
 336         return result;
 337 }
 338
 339 /*
 340  *
 341  *
 342  */
 343 /* FIXME: split and cleanup */
 344 int wusb_dev_4way_handshake(struct wusbhc *wusbhc, struct wusb_dev *wusb_dev,
 345                             struct wusb_ckhdid *ck)
 346 {
 347         int result = -ENOMEM;
 348         struct usb_device *usb_dev = wusb_dev->usb_dev;
 349         struct device *dev = &usb_dev->dev;
 350         u32 tkid;
 351         __le32 tkid_le;
 352         struct usb_handshake *hs;
 353         struct aes_ccm_nonce ccm_n;
 354         u8 mic[8];
 355         struct wusb_keydvt_in keydvt_in;
 356         struct wusb_keydvt_out keydvt_out;
 357
 358         hs = kzalloc(3*sizeof(hs[0]), GFP_KERNEL);
 359         if (hs == NULL) {
 360                 dev_err(dev, "can't allocate handshake data\n");
 361                 goto error_kzalloc;
 362         }
 363
 364         /* We need to turn encryption before beginning the 4way
 365          * hshake (WUSB1.0[.3.2.2]) */
 366         result = wusb_dev_set_encryption(usb_dev, 1);
 367         if (result < 0)
 368                 goto error_dev_set_encryption;
 369
 370         tkid = wusbhc_next_tkid(wusbhc, wusb_dev);
 371         tkid_le = cpu_to_le32(tkid);
 372
 373         hs[0].bMessageNumber = 1;
 374         hs[0].bStatus = 0;
 375         memcpy(hs[0].tTKID, &tkid_le, sizeof(hs[0].tTKID));
 376         hs[0].bReserved = 0;
 377         memcpy(hs[0].CDID, &wusb_dev->cdid, sizeof(hs[0].CDID));
 378         get_random_bytes(&hs[0].nonce, sizeof(hs[0].nonce));
 379         memset(hs[0].MIC, 0, sizeof(hs[0].MIC));        /* Per WUSB1.0[T7-22] */
 380
 381         result = usb_control_msg(
 382                 usb_dev, usb_sndctrlpipe(usb_dev, 0),
 383                 USB_REQ_SET_HANDSHAKE,
 384                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 385                 1, 0, &hs[0], sizeof(hs[0]), 1000 /* FIXME: arbitrary */);
 386         if (result < 0) {
 387                 dev_err(dev, "Handshake1: request failed: %d\n", result);
 388                 goto error_hs1;
 389         }
 390
 391         /* Handshake 2, from the device -- need to verify fields */
 392         result = usb_control_msg(
 393                 usb_dev, usb_rcvctrlpipe(usb_dev, 0),
 394                 USB_REQ_GET_HANDSHAKE,
 395                 USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 396                 2, 0, &hs[1], sizeof(hs[1]), 1000 /* FIXME: arbitrary */);
 397         if (result < 0) {
 398                 dev_err(dev, "Handshake2: request failed: %d\n", result);
 399                 goto error_hs2;
 400         }
 401
 402         result = -EINVAL;
 403         if (hs[1].bMessageNumber != 2) {
 404                 dev_err(dev, "Handshake2 failed: bad message number %u\n",
 405                         hs[1].bMessageNumber);
 406                 goto error_hs2;
 407         }
 408         if (hs[1].bStatus != 0) {
 409                 dev_err(dev, "Handshake2 failed: bad status %u\n",
 410                         hs[1].bStatus);
 411                 goto error_hs2;
 412         }
 413         if (memcmp(hs[0].tTKID, hs[1].tTKID, sizeof(hs[0].tTKID))) {
 414                 dev_err(dev, "Handshake2 failed: TKID mismatch "
 415                         "(#1 0x%02x%02x%02x vs #2 0x%02x%02x%02x)\n",
 416                         hs[0].tTKID[0], hs[0].tTKID[1], hs[0].tTKID[2],
 417                         hs[1].tTKID[0], hs[1].tTKID[1], hs[1].tTKID[2]);
 418                 goto error_hs2;
 419         }
 420         if (memcmp(hs[0].CDID, hs[1].CDID, sizeof(hs[0].CDID))) {
 421                 dev_err(dev, "Handshake2 failed: CDID mismatch\n");
 422                 goto error_hs2;
 423         }
 424
 425         /* Setup the CCM nonce */
 426         memset(&ccm_n.sfn, 0, sizeof(ccm_n.sfn));       /* Per WUSB1.0[6.5.2] */
 427         memcpy(ccm_n.tkid, &tkid_le, sizeof(ccm_n.tkid));
 428         ccm_n.src_addr = wusbhc->uwb_rc->uwb_dev.dev_addr;
 429         ccm_n.dest_addr.data[0] = wusb_dev->addr;
 430         ccm_n.dest_addr.data[1] = 0;
 431
 432         /* Derive the KCK and PTK from CK, the CCM, H and D nonces */
 433         memcpy(keydvt_in.hnonce, hs[0].nonce, sizeof(keydvt_in.hnonce));
 434         memcpy(keydvt_in.dnonce, hs[1].nonce, sizeof(keydvt_in.dnonce));
 435         result = wusb_key_derive(&keydvt_out, ck->data, &ccm_n, &keydvt_in);
 436         if (result < 0) {
 437                 dev_err(dev, "Handshake2 failed: cannot derive keys: %d\n",
 438                         result);
 439                 goto error_hs2;
 440         }
 441
 442         /* Compute MIC and verify it */
 443         result = wusb_oob_mic(mic, keydvt_out.kck, &ccm_n, &hs[1]);
 444         if (result < 0) {
 445                 dev_err(dev, "Handshake2 failed: cannot compute MIC: %d\n",
 446                         result);
 447                 goto error_hs2;
 448         }
 449
 450         if (memcmp(hs[1].MIC, mic, sizeof(hs[1].MIC))) {
 451                 dev_err(dev, "Handshake2 failed: MIC mismatch\n");
 452                 goto error_hs2;
 453         }
 454
 455         /* Send Handshake3 */
 456         hs[2].bMessageNumber = 3;
 457         hs[2].bStatus = 0;
 458         memcpy(hs[2].tTKID, &tkid_le, sizeof(hs[2].tTKID));
 459         hs[2].bReserved = 0;
 460         memcpy(hs[2].CDID, &wusb_dev->cdid, sizeof(hs[2].CDID));
 461         memcpy(hs[2].nonce, hs[0].nonce, sizeof(hs[2].nonce));
 462         result = wusb_oob_mic(hs[2].MIC, keydvt_out.kck, &ccm_n, &hs[2]);
 463         if (result < 0) {
 464                 dev_err(dev, "Handshake3 failed: cannot compute MIC: %d\n",
 465                         result);
 466                 goto error_hs2;
 467         }
 468
 469         result = usb_control_msg(
 470                 usb_dev, usb_sndctrlpipe(usb_dev, 0),
 471                 USB_REQ_SET_HANDSHAKE,
 472                 USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 473                 3, 0, &hs[2], sizeof(hs[2]), 1000 /* FIXME: arbitrary */);
 474         if (result < 0) {
 475                 dev_err(dev, "Handshake3: request failed: %d\n", result);
 476                 goto error_hs3;
 477         }
 478
 479         result = wusbhc->set_ptk(wusbhc, wusb_dev->port_idx, tkid,
 480                                  keydvt_out.ptk, sizeof(keydvt_out.ptk));
 481         if (result < 0)
 482                 goto error_wusbhc_set_ptk;
 483
 484         result = wusb_dev_set_gtk(wusbhc, wusb_dev);
 485         if (result < 0) {
 486                 dev_err(dev, "Set GTK for device: request failed: %d\n",
 487                         result);
 488                 goto error_wusbhc_set_gtk;
 489         }
 490
 491         /* Update the device's address from unauth to auth */
 492         if (usb_dev->authenticated == 0) {
 493                 result = wusb_dev_update_address(wusbhc, wusb_dev);
 494                 if (result < 0)
 495                         goto error_dev_update_address;
 496         }
 497         result = 0;
 498         dev_info(dev, "device authenticated\n");
 499
 500 error_dev_update_address:
 501 error_wusbhc_set_gtk:
 502 error_wusbhc_set_ptk:
 503 error_hs3:
 504 error_hs2:
 505 error_hs1:
 506         memset(hs, 0, 3*sizeof(hs[0]));
 507         memset(&keydvt_out, 0, sizeof(keydvt_out));
 508         memset(&keydvt_in, 0, sizeof(keydvt_in));
 509         memset(&ccm_n, 0, sizeof(ccm_n));
 510         memset(mic, 0, sizeof(mic));
 511         if (result < 0)
 512                 wusb_dev_set_encryption(usb_dev, 0);
 513 error_dev_set_encryption:
 514         kfree(hs);
 515 error_kzalloc:
 516         return result;
 517 }
 518
 519 /*
 520  * Once all connected and authenticated devices have received the new
 521  * GTK, switch the host to using it.
 522  */
 523 static void wusbhc_gtk_rekey_done_work(struct work_struct *work)
 524 {
 525         struct wusbhc *wusbhc = container_of(work, struct wusbhc, gtk_rekey_done_work);
 526         size_t key_size = sizeof(wusbhc->gtk.data);
 527
 528         mutex_lock(&wusbhc->mutex);
 529
 530         if (--wusbhc->pending_set_gtks == 0)
 531                 wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid, &wusbhc->gtk.descr.bKeyData, key_size);
 532
 533         mutex_unlock(&wusbhc->mutex);
 534 }
 535
 536 static void wusbhc_set_gtk_callback(struct urb *urb)
 537 {
 538         struct wusbhc *wusbhc = urb->context;
 539
 540         queue_work(wusbd, &wusbhc->gtk_rekey_done_work);
 541 }
 542
 543 /**
 544  * wusbhc_gtk_rekey - generate and distribute a new GTK
 545  * @wusbhc: the WUSB host controller
 546  *
 547  * Generate a new GTK and distribute it to all connected and
 548  * authenticated devices.  When all devices have the new GTK, the host
 549  * starts using it.
 550  *
 551  * This must be called after every device disconnect (see [WUSB]
 552  * section 6.2.11.2).
 553  */
 554 void wusbhc_gtk_rekey(struct wusbhc *wusbhc)
 555 {
 556         static const size_t key_size = sizeof(wusbhc->gtk.data);
 557         int p;
 558
 559         wusbhc_generate_gtk(wusbhc);
 560
 561         for (p = 0; p < wusbhc->ports_max; p++) {
 562                 struct wusb_dev *wusb_dev;
 563
 564                 wusb_dev = wusbhc->port[p].wusb_dev;
 565                 if (!wusb_dev || !wusb_dev->usb_dev || !wusb_dev->usb_dev->authenticated)
 566                         continue;
 567
 568                 usb_fill_control_urb(wusb_dev->set_gtk_urb, wusb_dev->usb_dev,
 569                                      usb_sndctrlpipe(wusb_dev->usb_dev, 0),
 570                                      (void *)wusb_dev->set_gtk_req,
 571                                      &wusbhc->gtk.descr, wusbhc->gtk.descr.bLength,
 572                                      wusbhc_set_gtk_callback, wusbhc);
 573                 if (usb_submit_urb(wusb_dev->set_gtk_urb, GFP_KERNEL) == 0)
 574                         wusbhc->pending_set_gtks++;
 575         }
 576         if (wusbhc->pending_set_gtks == 0)
 577                 wusbhc->set_gtk(wusbhc, wusbhc->gtk_tkid, &wusbhc->gtk.descr.bKeyData, key_size);
 578 }