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